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LaBarge TW, Gardner JD, Organ CL. The evolution and ecology of gigantism in terror birds (Aves, Phorusrhacidae). Proc Biol Sci 2024; 291:20240235. [PMID: 38654650 PMCID: PMC11040249 DOI: 10.1098/rspb.2024.0235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/22/2024] [Indexed: 04/26/2024] Open
Abstract
Terror birds (Aves, Phorusrhacidae) were large flightless apex predators in South America during the Cenozoic. Here, we estimate a new phylogeny for phorusrhacids using Bayesian inference. We demonstrate phylogenetic evidence for a monophyletic Patagornithinae and find significant support for a distinct crown group associated with the quintessential 'terror bird' characteristics. We use this phylogeny to analyse the evolution of body size and cursoriality. Our results reveal that size overlap was rare between co-occurring subfamilies, supporting the hypothesis that these traits were important for niche partitioning. We observe that gigantism evolved in a single clade, containing Phorusrhacinae and Physornithinae. The members of this lineage were consistently larger than all other phorusrhacids. Phorusrhacinae emerged following the extinction of Physornithinae, suggesting the ecological succession of the apex predator niche. The first known phorusrhacine, Phorusrhacos longissimus, was gigantic but significantly smaller and more cursorial than any physornithine. These traits likely evolved in response to the expansion of open environments. Following the Santacrucian SALMA, phorusrhacines increased in size, further converging on the morphology of Physornithinae. These findings suggest that the evolution and displacement of body size drove terror bird niche partitioning and competitive exclusion controlled phorusrhacid diversity.
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Affiliation(s)
- Thomas W. LaBarge
- Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN, USA
| | - Jacob D. Gardner
- School of Biological Sciences, University of Reading, Reading, Berkshire, UK
| | - Chris L. Organ
- Department of Earth Sciences, Montana State University, Bozeman, MT, USA
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2
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Wilson LN, Gardner JD, Wilson JP, Farnsworth A, Perry ZR, Druckenmiller PS, Erickson GM, Organ CL. Global latitudinal gradients and the evolution of body size in dinosaurs and mammals. Nat Commun 2024; 15:2864. [PMID: 38580657 PMCID: PMC10997647 DOI: 10.1038/s41467-024-46843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 03/12/2024] [Indexed: 04/07/2024] Open
Abstract
Global climate patterns fundamentally shape the distribution of species and ecosystems. For example, Bergmann's rule predicts that homeothermic animals, including birds and mammals, inhabiting cooler climates are generally larger than close relatives from warmer climates. The modern world, however, lacks the comparative data needed to evaluate such macroecological rules rigorously. Here, we test for Bergmann's rule in Mesozoic dinosaurs and mammaliaforms that radiated within relatively temperate global climate regimes. We develop a phylogenetic model that accounts for biases in the fossil record and allows for variable evolutionary dispersal rates. Our analysis also includes new fossil data from the extreme high-latitude Late Cretaceous Arctic Prince Creek Formation. We find no evidence for Bergmann's rule in Mesozoic dinosaurs or mammaliaforms, the ancestors of extant homeothermic birds and mammals. When our model is applied to thousands of extant dinosaur (bird) and mammal species, we find that body size evolution remains independent of latitude. A modest temperature effect is found in extant, but not in Mesozoic, birds, suggesting that body size evolution in modern birds was influenced by Bergmann's rule during Cenozoic climatic change. Our study provides a general approach for studying macroecological rules, highlighting the fossil record's power to address longstanding ecological principles.
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Affiliation(s)
- Lauren N Wilson
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA.
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA.
| | - Jacob D Gardner
- School of Biological Sciences, University of Reading, Reading, RG6 6EX, UK.
| | - John P Wilson
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59715, USA
| | - Alex Farnsworth
- School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1RL, UK
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zackary R Perry
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA
| | - Patrick S Druckenmiller
- University of Alaska Museum, 1962 Yukon Drive, Fairbanks, AK, 99775, USA
- Department of Geosciences, University of Alaska, Fairbanks, AK, 99775, USA
| | - Gregory M Erickson
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Chris L Organ
- School of Biological Sciences, University of Reading, Reading, RG6 6EX, UK.
- Department of Earth Sciences, Montana State University, Bozeman, MT, 59715, USA.
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3
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Aguilar-Pedrayes I, Gardner JD, Organ CL. The coevolution of rostral keratin and tooth distribution in dinosaurs. Proc Biol Sci 2024; 291:20231713. [PMID: 38229513 DOI: 10.1098/rspb.2023.1713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/11/2023] [Indexed: 01/18/2024] Open
Abstract
Teeth evolved early in vertebrate evolution, and their morphology reflects important specializations in diet and ecology among species. The toothless jaws (edentulism) in extant birds likely coevolved with beak keratin, which functionally replaced teeth. However, extinct dinosaurs lost teeth multiple times independently and exhibited great variation in toothrow distribution and rhamphotheca-like keratin structures. Here, we use rostral jawbone surface texture as a proxy for rostral keratin covering and phylogenetic comparative models to test for the influence of rostral keratin on toothrow distribution in Mesozoic dinosaurs. We find that the evolution of rostral keratin covering explains partial toothrow reduction but not jaw toothlessness. Toothrow reduction preceded the evolution of rostral keratin cover in theropods. Non-theropod dinosaurs evolved continuous toothrows despite evolving rostral keratin covers (e.g. some ornithischians and sauropodomorphs). We also show that rostral keratin covers did not significantly increase the evolutionary rate of tooth loss, which further delineates the antagonistic relationship between these structures. Our results suggest that the evolution of rostral keratin had a limited effect on suppressing tooth development. Independent changes in jaw development may have facilitated further tooth loss. Furthermore, the evolution of strong chemical digestion, a gizzard, and a dietary shift to omnivory or herbivory likely alleviated selective pressures for tooth development.
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Affiliation(s)
- Isaura Aguilar-Pedrayes
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Earth Sciences, University of Bristol, Bristol BS8 1QU, UK
| | - Jacob D Gardner
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK
| | - Chris L Organ
- Department of Earth Sciences, Montana State University, Bozeman, MT 59715, USA
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK
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4
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Surya K, Gardner JD, Organ CL. Detecting punctuated evolution in SARS-CoV-2 over the first year of the pandemic. Front Virol 2023. [DOI: 10.3389/fviro.2023.1066147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) evolved slowly over the first year of the Coronavirus Disease 19 (COVID-19) pandemic with differential mutation rates across lineages. Here, we explore how this variation arose. Whether evolutionary change accumulated gradually within lineages or during viral lineage branching is unclear. Using phylogenetic regression models, we show that ~13% of SARS-CoV-2 genomic divergence up to May 2020 is attributable to lineage branching events (punctuated evolution). The net number of branching events along lineages predicts ~5% of the deviation from the strict molecular clock. We did not detect punctuated evolution in SARS-CoV-1, possibly due to the small sample size, and in sarbecovirus broadly, likely due to a different evolutionary process altogether. Punctuation in SARS-CoV-2 is probably neutral because most mutations were not positively selected and because the strength of the punctuational effect remained constant over time, at least until May 2020, and across continents. However, the small punctuational contribution to SARS-CoV-2 diversity is consistent with the founder effect arising from narrow transmission bottlenecks. Therefore, punctuation in SARS-CoV-2 may represent the macroevolutionary consequence (rate variation) of a microevolutionary process (transmission bottleneck).
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5
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Xue J, Wang W, Shao J, Dai X, Sun Z, Gardner JD, Chen L, Guo X, Di N, Pei X, Wu X, Zhang G, Cui C, Cao P, Liu F, Dai Q, Feng X, Yang R, Ping W, Zhang L, He N, Fu Q. Ancient Mitogenomes Reveal the Origins and Genetic Structure of the Neolithic Shimao Population in Northern China. Front Genet 2022; 13:909267. [PMID: 35692842 PMCID: PMC9185412 DOI: 10.3389/fgene.2022.909267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Shimao City is considered an important political and religious center during the Late Neolithic Longshan period of the Middle Yellow River basin. The genetic history and population dynamics among the Shimao and other ancient populations, especially the Taosi-related populations, remain unknown. Here, we sequenced 172 complete mitochondrial genomes, ranging from the Yangshao to Longshan period, from individuals related to the Shimao culture in northern Shaanxi Province and Taosi culture in southern Shanxi Province, Middle Yellow River basin. Our results show that the populations inhabiting Shimao City had close genetic connections with an earlier population in the Middle Neolithic Yangshao period of northern Shaanxi Province, revealing a mostly local origin for the Shimao Society. In addition, among the populations in other regions of the Yellow River basin, the Shimao-related populations had the closest maternal affinity with the contemporaneous Taosi populations from the Longshan period. The Shimao-related populations also shared more affinity with present-day northern Han populations than with the minorities and southern Han in China. Our study provides a new perspective on the genetic origins and structure of the Shimao people and the population dynamics in the Middle Yellow River basin during the Neolithic period.
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Affiliation(s)
- Jiayang Xue
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenjun Wang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
- Science and Technology Archaeology, National Centre for Archaeology, Beijing, China
| | - Jing Shao
- Shaanxi Academy of Archaeology, Xi’an, China
| | - Xiangming Dai
- Archaeology Institute of National Museum of China, Beijing, China
| | | | - Jacob D. Gardner
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Liang Chen
- School of Cultural Heritage, Northwest University, Xi’an, China
| | | | - Nan Di
- Shaanxi Academy of Archaeology, Xi’an, China
| | - Xuesong Pei
- Shaanxi Academy of Archaeology, Xi’an, China
| | - Xiaohong Wu
- School of Archaeology and Museology, Peking University, Beijing, China
| | - Ganyu Zhang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Can Cui
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Peng Cao
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Feng Liu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Qingyan Dai
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Xiaotian Feng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Ruowei Yang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Wanjing Ping
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lizhao Zhang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
| | - Nu He
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing, China
- *Correspondence: Qiaomei Fu, ; Nu He,
| | - Qiaomei Fu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Shanghai Qi Zhi Institute, Shanghai, China
- *Correspondence: Qiaomei Fu, ; Nu He,
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6
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Zhang M, Liu Y, Li Z, Lü P, Gardner JD, Ye M, Wang J, Yang M, Shao J, Wang W, Dai Q, Cao P, Yang R, Liu F, Feng X, Zhang L, Li E, Shi Y, Chen Z, Zhu S, Zhai W, Deng T, Duan Z, Bennett EA, Hu S, Fu Q. Ancient DNA reveals the maternal genetic history of East Asian domestic pigs. J Genet Genomics 2021; 49:537-546. [PMID: 34902603 DOI: 10.1016/j.jgg.2021.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 10/19/2022]
Abstract
Zoo-archaeological and genetic evidence suggest that pigs were domesticated independently in Central China and Eastern Anatolia along with the development of agricultural communities and civilizations. However, the genetic history of domestic pigs, especially in China, has not been fully explored. In this study, we generated 42 complete mitochondrial DNA sequences from ∼7500- to 2750-year-old individuals from the Yellow River basin. Our results show that the maternal genetic continuity of East Asian domestic pigs dates back to at least the Early to Middle Neolithic. In contrast, the Near Eastern ancestry in European domestic pigs saw a near-complete genomic replacement by the European wild boar. The majority of East Asian domestic pigs share close haplotypes, and the most recent common ancestor of most branches dates back to less than 20,000 years before present, inferred using new substitution rates of whole mitogenomes or combined protein-coding regions. Two major population expansion events of East Asian domestic pigs coincided with changes in climate, widespread adoption of introduced crops, and the development of agrarian societies. These findings add to our understanding of the maternal genetic composition and help to complete the picture of domestic pig evolutionary history in East Asia.
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Affiliation(s)
- Ming Zhang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China; Shanghai Qi Zhi Institute, Shanghai 200232, China
| | - Yichen Liu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Zhipeng Li
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Peng Lü
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Jacob D Gardner
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Maolin Ye
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China; School of History and Culture, Lanzhou University, Lanzhou 730000, China
| | - Jihuai Wang
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | | | - Jing Shao
- Shaanxi Academy of Archaeology, Xi'an 710054, China
| | - Weilin Wang
- School of History and Culture, Shanxi University, Taiyuan 030006, China
| | - Qingyan Dai
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Peng Cao
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Ruowei Yang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Feng Liu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Xiaotian Feng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Lizhao Zhang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Enwei Li
- Xingtai Cultural Relics Administration, Xingtai 054000, China
| | - Yunzheng Shi
- Xingtai Cultural Relics Administration, Xingtai 054000, China
| | - Zehui Chen
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Shilun Zhu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Weiwei Zhai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tao Deng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Ziyuan Duan
- Institute of Genetics and Developmental Biology Chinese Academy of Sciences, Beijing 100101, China
| | - E Andrew Bennett
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China.
| | - Songmei Hu
- Shaanxi Academy of Archaeology, Xi'an 710054, China.
| | - Qiaomei Fu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China; Shanghai Qi Zhi Institute, Shanghai 200232, China.
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Gardner JD, Organ CL. Evolutionary Sample Size and Consilience in Phylogenetic Comparative Analysis. Syst Biol 2021; 70:1061-1075. [PMID: 33720380 DOI: 10.1093/sysbio/syab017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 03/05/2021] [Accepted: 03/10/2021] [Indexed: 11/15/2022] Open
Abstract
Phylogenetic comparative methods (PCMs) are commonly used to study evolution and adaptation. However, frequently used PCMs for discrete traits mishandle single evolutionary transitions. They erroneously detect correlated evolution in these situations. For example, hair and mammary glands cannot be said to have evolved in a correlated fashion because each evolved only once in mammals, but a commonly used model (Pagel's Discrete) statistically supports correlated (dependent) evolution. Using simulations, we find that rate parameter estimation, which is central for model selection, is poor in these scenarios due to small effective (evolutionary) sample sizes of independent character state change. Pagel's Discrete model also tends to favor dependent evolution in these scenarios, in part, because it forces evolution through state combinations unobserved in the tip data. This model prohibits simultaneous dual transitions along branches. Models with underlying continuous data distributions (e.g., Threshold and GLMM) are less prone to favor correlated evolution, but are still susceptible when evolutionary sample sizes are small. We provide three general recommendations for researchers who encounter these common situations: 1) Create study designs that evaluate a priori hypotheses and maximize evolutionary sample sizes; 2) assess the suitability of evolutionary models-for discrete traits, we introduce the phylogenetic imbalance ratio; and 3) evaluate evolutionary hypotheses with a consilience of evidence from disparate fields, like biogeography and developmental biology. Consilience plays a central role in hypothesis testing within the historical sciences where experiments are difficult or impossible to conduct, such as many hypotheses about correlated evolution. These recommendations are useful for investigations that employ any type of PCM.
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Affiliation(s)
- Jacob D Gardner
- Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Chris L Organ
- Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA
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8
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Wang W, Ding M, Gardner JD, Wang Y, Miao B, Guo W, Wu X, Ruan Q, Yu J, Hu X, Wang B, Wu X, Tang Z, Niyazi A, Zhang J, Chang X, Tang Y, Ren M, Cao P, Liu F, Dai Q, Feng X, Yang R, Zhang M, Wang T, Ping W, Hou W, Li W, Ma J, Kumar V, Fu Q. Ancient Xinjiang mitogenomes reveal intense admixture with high genetic diversity. Sci Adv 2021; 7:7/14/eabd6690. [PMID: 33789892 PMCID: PMC8011967 DOI: 10.1126/sciadv.abd6690] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Xinjiang is a key region in northwestern China, connecting East and West Eurasian populations and cultures for thousands of years. To understand the genetic history of Xinjiang, we sequenced 237 complete ancient human mitochondrial genomes from the Bronze Age through Historical Era (41 archaeological sites). Overall, the Bronze Age Xinjiang populations show high diversity and regional genetic affinities with Steppe and northeastern Asian populations along with a deep ancient Siberian connection for the Tarim Basin Xiaohe individuals. In the Iron Age, in general, Steppe-related and northeastern Asian admixture intensified, with North and East Xinjiang populations showing more affinity with northeastern Asians and South Xinjiang populations showing more affinity with Central Asians. The genetic structure observed in the Historical Era of Xinjiang is similar to that in the Iron Age, demonstrating genetic continuity since the Iron Age with some additional genetic admixture with populations surrounding the Xinjiang region.
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Affiliation(s)
- Wenjun Wang
- College of Life Sciences, Northwest University, Xi'an 710069, China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Manyu Ding
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jacob D Gardner
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongqiang Wang
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Bo Miao
- College of Life Sciences, Northwest University, Xi'an 710069, China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Wu Guo
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Xinhua Wu
- Institute of Archaeology, Chinese Academy of Social Sciences, Beijing 100710, China
| | - Qiurong Ruan
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Jianjun Yu
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Xingjun Hu
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Bo Wang
- Xinjiang Uygur Autonomous Region Museum, Urumqi 830002, China
| | - Xiaohong Wu
- School of Archaeology and Museology, Peking University, Beijing 100871, China
| | - Zihua Tang
- Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Alipujiang Niyazi
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Jie Zhang
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Xien Chang
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Yunpeng Tang
- School of Cultural Heritage, Northwest University, Xi'an 710069, China
| | - Meng Ren
- School of Cultural Heritage, Northwest University, Xi'an 710069, China
| | - Peng Cao
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Feng Liu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Qingyan Dai
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Xiaotian Feng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Ruowei Yang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Ming Zhang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tianyi Wang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
- School of Cultural Heritage, Northwest University, Xi'an 710069, China
| | - Wanjing Ping
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Weihong Hou
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Wenying Li
- Institute of Cultural Relics and Archaeology in Xinjiang, Urumqi 830011, China
| | - Jian Ma
- School of Cultural Heritage, Northwest University, Xi'an 710069, China
| | - Vikas Kumar
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
| | - Qiaomei Fu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.
- Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Gardner JD, Laurin M, Organ CL. The relationship between genome size and metabolic rate in extant vertebrates. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190146. [PMID: 31928192 PMCID: PMC7017434 DOI: 10.1098/rstb.2019.0146] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2019] [Indexed: 12/13/2022] Open
Abstract
Genome size has long been hypothesized to affect the metabolic rate in various groups of animals. The mechanism behind this proposed association is the nucleotypic effect, in which large nucleus and cell sizes influence cellular metabolism through surface area-to-volume ratios. Here, we provide a review of the recent literature on the relationship between genome size and metabolic rate. We also conduct an analysis using phylogenetic comparative methods and a large sample of extant vertebrates. We find no evidence that the effect of genome size improves upon models in explaining metabolic rate variation. Not surprisingly, our results show a strong positive relationship between metabolic rate and body mass, as well as a substantial difference in metabolic rate between endothermic and ectothermic vertebrates, controlling for body mass. The presence of endothermy can also explain elevated rate shifts in metabolic rate whereas genome size cannot. We further find no evidence for a punctuated model of evolution for metabolic rate. Our results do not rule out the possibility that genome size affects cellular physiology in some tissues, but they are consistent with previous research suggesting little support for a direct functional connection between genome size and basal metabolic rate in extant vertebrates. This article is part of the theme issue 'Vertebrate palaeophysiology'.
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Affiliation(s)
- Jacob D. Gardner
- Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Michel Laurin
- Centre de Recherches sur la Paléobiologie et les Paléoenvironnements (CR2P), Centre National de la Recherche Scientifique (CNRS)/Muséum National d'Histoire Naturelle (MNHN)/Sorbonne Université, Paris, France
| | - Chris L. Organ
- Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA
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Mouton AJ, El Hajj EC, Ninh VK, Siggins RW, Gardner JD. Inflammatory cardiac fibroblast phenotype underlies chronic alcohol-induced cardiac atrophy and dysfunction. Life Sci 2020; 245:117330. [PMID: 31962130 DOI: 10.1016/j.lfs.2020.117330] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/08/2020] [Accepted: 01/15/2020] [Indexed: 01/05/2023]
Abstract
AIMS The purpose of this study was to investigate mechanisms of chronic alcohol-induced cardiac remodeling and dysfunction. We also sought to determine the role of cardiac fibroblasts, which play a dynamic role in cardiac remodeling, in mediating these effects. MAIN METHODS Adult male Wistar rats were exposed to ethanol (EtOH) vapor inhalation for 16 weeks. Echocardiography was performed to assess terminal cardiac structure and function. Cardiac fibroblasts were isolated from the left ventricle (LV) for both ex vivo and in vitro analysis. Cultured H9C2 cells were also exposed to conditioned media from alcohol-exposed cardiac fibroblasts. Gene expression in whole LV tissue, isolated cardiac fibroblasts, or cultured H9C2 cells was determined by real-time PCR, and protein expression was determined by Western blot. KEY FINDINGS EtOH led to LV wall thinning and impaired systolic function, and decreased contractile protein mRNA levels. EtOH increased LV inflammatory markers, JNK and Akt activation, and decreased mTOR expression. EtOH induced myofibroblast activation as assessed by flow cytometry, and increased LV collagen III expression. EtOH increased expression of several inflammatory mediators in cardiac fibroblasts both ex vivo and in vitro. Administration of conditioned media from EtOH-treated fibroblasts decreased contractile protein mRNA levels and impaired Akt and mTOR signaling in differentiated H9C2 cardiomyocytes. SIGNIFICANCE Our results indicate that EtOH-induced cardiac atrophy and dysfunction is associated with activation of inflammatory pathways. Furthermore, EtOH may induce a pro-inflammatory cardiac fibroblast phenotype, leading to aberrant fibroblast-myocyte cross-talk. Thus, EtOH may promote cardiac muscle wasting in part by activation of pro-inflammatory fibroblasts.
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Affiliation(s)
- A J Mouton
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70124, United States of America
| | - E C El Hajj
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70124, United States of America
| | - V K Ninh
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70124, United States of America
| | - R W Siggins
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70124, United States of America
| | - J D Gardner
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70124, United States of America.
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El Hajj MC, Ninh VK, El Hajj EC, Bradley JM, Gardner JD. Estrogen receptor antagonism exacerbates cardiac structural and functional remodeling in female rats. Am J Physiol Heart Circ Physiol 2016; 312:H98-H105. [PMID: 27769996 DOI: 10.1152/ajpheart.00348.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 10/04/2016] [Accepted: 10/17/2016] [Indexed: 12/24/2022]
Abstract
We have previously demonstrated the cardioprotective effects of ovarian hormones against adverse ventricular remodeling imposed by chronic volume overload. Here, we assess the estrogen receptor dependence of this cardioprotection. Four groups of female rats were studied: sham-operated (Sham), volume overloaded [aortocaval fistula (ACF)], Sham treated with estrogen receptor antagonist ICI 182,780 (Sham + ICI), and ACF treated with ICI. Cardiac function was assessed temporally using echocardiogram, and tissue samples were collected at 5 days and 6 wk postsurgery. All rats with volume overload had significantly increased cardiac output (96 ± 32 ml/min for ACF and 108 ± 11 ml/min for ACF + ICI vs. 31 ± 2 for Sham, P < 0.05). At 6 wk, volume overload induced significant left ventricular (LV) hypertrophy in both untreated and treated ACF groups. Both ACF groups developed significantly increased LV end-diastolic diameter (LVEDD), indicating LV dilatation, with the ACF + ICI group having the greatest increase (340%, relative to Sham). Ejection fraction was significantly reduced in the ACF + ICI group (23% reduction) at 6 wk postsurgery compared with untreated ACF (P < 0.05). Interstitial collagen staining was significantly reduced by volume overload, with estrogen receptor antagonism causing greater collagen loss at both 5 days and 6 wk postsurgery. Furthermore, volume overload induced a significant increase in LV wall stress only in rats treated with estrogen antagonist. These data indicate that estrogen receptor signaling is essential for sex hormone-dependent cardioprotection against adverse remodeling. The maintenance of myocardial extracellular matrix collagen appears to play a key role in this cardioprotection. NEW & NOTEWORTHY We assessed the estrogen receptor (ER) dependence of female-specific cardioprotection using a rat model of chronic volume-overload stress. ER antagonism worsened ventricular wall stress, ventricular dilation, and cardiac dysfunction induced by volume overload. Further, blocking ERs resulted in cardiac remodeling and functional changes similar to that previously found in ovariectomized rats.
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Affiliation(s)
- M C El Hajj
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - V K Ninh
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - E C El Hajj
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - J M Bradley
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - J D Gardner
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
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12
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Affiliation(s)
- J D Gardner
- Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, Louisiana
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Abstract
BACKGROUND Previously, we hypothesized that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity. AIM To test the hypothesis that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity. METHODS Twenty-two healthy humans ingested a standard meal containing [(14)C]octanoic acid and [(13)C]glycine over 30 min on 2 separate occasions. Gastric pH was measured for 90 min before and 240 min after the meal. 10 mm HCl was infused continuously at 1 mL/min into either the distal oesophagus or stomach in a 2-way crossover fashion for 60 min before and 240 min after the meal. Gastric emptying of solid and liquid were determined with breath tests. RESULTS Compared to gastric infusion, oesophageal infusion significantly decreased gastric acidity after the meal, but not before the meal and the magnitude of the decrease varied directly with gastric acidity. Gastric emptying of solid or liquid with oesophageal infusion was not significantly different from that with gastric infusion. CONCLUSIONS These findings support the hypothesis of the existence of a physiological oesophago-gastric feedback mechanism that might contribute to regulation of postprandial gastric acidity. Oesophageal acidification might decode gastric information and signal the stomach to decrease gastric acidity. Further studies are needed to assess the characteristics of such feedback mechanism in-patients with gastro-oesophageal reflux disease (GERD).
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Affiliation(s)
- K Blondeau
- Center for Gastroenterological Research, Catholic University of Leuven, Leuven, Belgium
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15
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Gardner JD, Young W, Sloan S, Robinson M, Miner PB. The effects of changing temperature correction factors on measures of acidity calculated from gastric and oesophageal pH recordings. Aliment Pharmacol Ther 2006; 23:629-38. [PMID: 16480402 DOI: 10.1111/j.1365-2036.2006.02787.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Recently, Medtronic notified customers that new correction factors should be used for their Slimline and Zinetics24 single-use, internal-standard pH catheters. AIM AND METHODS We selected 24-h recordings of oesophageal and gastric pH with the Zinetics24 from our archives for five healthy subjects and for five gastro-oesophageal reflux disease subjects who were studied at baseline and again after 8 days of treatment with a proton-pump inhibitor. All pH values obtained with the old correction factors were rescaled using the new correction factors. Values for median pH, integrated acidity and time pH < or = 4 were then calculated from pH values with old and new correction factors. RESULTS The new correction factors changed values for median pH, integrated acidity and time pH < or = 4. Values for median pH and integrated acidity changed in a predictable, proportionate way, whereas values for time pH < or = 4 did not. CONCLUSIONS The new correction factors will not change the interpretation of previously published results with median pH or integrated acidity. In contrast, values for time < or =4 cannot be converted in an obvious way with the new correction factors. Instead, the raw pH data will need to be rescaled and values for time pH < or = 4 recalculated using the rescaled pH data.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc, Chatham, NJ 07928, USA.
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16
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Abstract
BACKGROUND We are unaware of the analyses of time series data resulting from 24 h recordings of human gastric or oesophageal pH. As a result, we have no understanding of the quantitative changes in gastric or oesophageal acidity over time, the patterns that might characterize these changes, or the physiological significance of gastro-oesophageal reflux. AIM To examine the time series for gastric and oesophageal pH. METHODS Detrended fluctuation analysis and lag analysis were used to analyse data from 24 h recordings of oesophageal and gastric pH in five normal subjects and five subjects with gastro-oesophageal reflux disease. RESULTS Analyses of the patterns of gastric and oesophageal pH over time in normal subjects and subjects with gastro-oesophageal reflux disease indicate that the fluctuations in pH are self-similar across different time scales and are consistent with an underlying fractal process. Furthermore, there is a significant statistical association between sequential pH values separated by as much as 2.2 h. CONCLUSIONS We hypothesize that the self-similar, fractal pattern encodes information about gastric acidity and that the oesophagus decodes this information and, when appropriate, may signal the stomach to reduce gastric acidity. Subjects with gastro-oesophageal reflux disease might have an impaired oesophageal-gastric feedback mechanism that results in increased gastric acid, which reflux from the stomach into the oesophagus.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Gardner JD, Sloan S, Robinson M, Miner PB. Frequency analyses of gastric pH in control and gastro-oesophageal reflux disease subjects treated with a proton-pump inhibitor. Aliment Pharmacol Ther 2004; 20:1381-6. [PMID: 15606401 DOI: 10.1111/j.1365-2036.2004.02279.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND We are unaware of any solid theoretical or pathophysiological basis for selecting pH 4 or any other pH value to assess gastric acidity. AIM To examine the frequency of different gastric pH values in control and GERD subjects. METHODS Gastric pH was measured for 24 h in 26 control subjects, 26 gastro-oesophageal reflux disease subjects at baseline and the same 26 gastro-oesophageal reflux disease subjects during treatment with a proton-pump inhibitor. Histograms were constructed using the 21 600 values generated from each recording and bins of 0.25 pH units. RESULTS The distribution of gastric pH values in gastro-oesophageal reflux disease subjects was significantly different from that in controls and in some instances the distributions detected significant differences that were not detected by integrated acidity. Proton-pump inhibitor treatment significantly altered the distribution of gastric pH values and the nature of this alteration during the postprandial period was different from that during the nocturnal period. Using time pH< or =4 can significantly underestimate the magnitude of inhibition of gastric acidity caused by a proton-pump inhibitor. CONCLUSIONS The distribution of gastric pH values provides a rationale for selecting a particular pH value to assess gastric acidity. In some instances, the distribution of gastric pH values detects significant differences between gastro-oesophageal reflux disease and normal subjects that are not detected by integrated acidity.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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18
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Abstract
BACKGROUND We are unaware of any solid theoretical or pathophysiological basis for selecting pH 4 or any other pH value to assess oesophageal acid exposure or to define oesophageal reflux episodes. AIM To examine the frequency of different oesophageal pH values in control and GERD subjects. METHODS Oesophageal pH was measured for 24 h in 57 gastro-oesophageal reflux disease subjects and 26 control subjects. Histograms were constructed using the 21,600 values from each recording and bins of 0.25 pH units. RESULTS Compared with controls, gastro-oesophageal reflux disease subjects had significantly more low pH values and significantly fewer high pH values. In both gastro-oesophageal reflux disease and control subjects, the frequency of oesophageal pH values was characterized by a power-law distribution indicating that the same relationship that describes low pH values also describes high pH values, as well as all values in between. CONCLUSIONS The distribution of oesophageal pH values indicates that a variety of different pH values can be used to assess oesophageal acid exposure, but raises important questions regarding how oesophageal reflux episodes are defined.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Gardner JD, Gallo-Torres H, Sloan S, Robinson M, Miner PB. The basis for the decreased response to proton pump inhibitors in gastro-oesophageal reflux disease patients without erosive oesophagitis. Aliment Pharmacol Ther 2003; 18:891-905. [PMID: 14616153 DOI: 10.1046/j.1365-2036.2003.01777.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The reason why heartburn in gastro-oesophageal reflux disease subjects without oesophagitis is less responsive to proton pump inhibitors than heartburn in those with erosive oesophagitis is not known. METHODS Gastric and oesophageal pH were determined in 26 subjects with gastro-oesophageal reflux disease at baseline and on days 1, 2 and 8 of treatment with 20 mg omeprazole or 20 mg rabeprazole in a randomized, two-way cross-over fashion. The presence or absence of erosive oesophagitis at baseline was documented by upper gastrointestinal endoscopy. RESULTS At a given value of the integrated gastric acidity during treatment with a proton pump inhibitor, the probability of pathological oesophageal reflux was significantly higher in subjects with no oesophagitis than in those with erosive oesophagitis. This occurred because the post-prandial gastric acidity in subjects with no oesophagitis showed a decreased response to the antisecretory agent. CONCLUSIONS Compared with gastro-oesophageal reflux disease subjects with erosive oesophagitis, those with no oesophagitis are relatively refractory to the pharmacodynamic effects of proton pump inhibitors on the post-prandial integrated gastric acidity.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Gardner JD, Sloan S, Robinson M, Miner PB. Heartburn severity can predict pathologic oesophageal reflux in gastro-oesophageal reflux disease patients treated with a proton-pump inhibitor. Aliment Pharmacol Ther 2003; 18:133-40. [PMID: 12848635 DOI: 10.1046/j.1365-2036.2003.01644.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
BACKGROUND In gastro-oesophageal reflux disease (GERD) subjects treated with a gastric anti-secretory agent, it is not known whether there is a relationship between heartburn severity and oesophageal acid exposure. METHODS Oesophageal pH and heartburn severity were determined in 27 GERD subjects at baseline and on days 1, 2 and 8 of treatment with 20 mg omeprazole or 20 mg rabeprazole in a randomized, two-way crossover fashion. RESULTS Receiver operating characteristic (ROC) analysis was used to determine values for heartburn severity that gave optimal cut-off points for distinguishing between normal and pathologic oesophageal reflux. Using these cut-off points, we found that the probability of no pathologic oesophageal reflux (Y) could be best fitted by an exponential equation: Y = a(e-bX) + c, where a, b and c are constants and X is the value of heartburn severity. There was close agreement between predicted and observed percentages of subjects with pathologic oesophageal reflux during different days of treatment. CONCLUSIONS In GERD subjects treated with a proton-pump inhibitor, the value of heartburn severity following a single standard meal can predict the likelihood of pathologic oesophageal reflux over the entire 24-h period.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, New Jersey 07928, USA.
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Gardner JD, Sloan S, Miner PB, Robinson M. Determination of the reduction in gastric acidity necessary to prevent pathological oesophageal reflux in patients with gastro-oesophageal reflux disease treated with a proton pump inhibitor. Aliment Pharmacol Ther 2003; 17:955-64. [PMID: 12656698 DOI: 10.1046/j.1365-2036.2003.01532.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND In subjects with gastro-oesophageal reflux disease treated with a gastric antisecretory agent, the extent to which gastric acidity needs to be reduced to prevent pathological oesophageal acid exposure is not known. METHODS Gastric and oesophageal pH were measured in 26 healthy subjects and in 59 subjects with gastro-oesophageal reflux disease. In 27 of the subjects with gastro-oesophageal reflux disease, pH was also recorded on days 1, 2 and 8 of treatment with 20 mg omeprazole and 20 mg rabeprazole in a randomized, two-way, cross-over fashion. RESULTS Receiver operating characteristic analysis was used to determine values for the integrated oesophageal acidity and time oesophageal pH<or=4 that gave optimal cut-off points for distinguishing between normal and pathological oesophageal reflux. Using these cut-off points, we found that the probability of no pathological oesophageal reflux (Y) could be best fitted by an exponential equation, Y = a(e-bX) + c, where a, b and c are constants and X is the value of the integrated gastric acidity. There was close agreement between the predicted and observed percentages of subjects with pathological oesophageal reflux during different days of treatment. CONCLUSIONS In subjects with gastro-oesophageal reflux disease treated with a proton pump inhibitor, the value of the integrated gastric acidity can predict the likelihood of pathological oesophageal reflux.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Abstract
BACKGROUND No current methods exist to determine meal-stimulated gastric acid secretion in humans under conditions that approximate those of daily living with the ingestion of breakfast, lunch and dinner. METHODS Gastric and oesophageal pH were measured in 26 healthy subjects and in 59 subjects with gastro-oesophageal reflux disease. Meal-stimulated gastric acid secretion was calculated from the buffer capacity of the meals determined in vitro and from the time required for the gastric pH to decrease to pH 2 in vivo following ingestion of the meal. RESULTS There was a significant correlation between gastric secretion with each meal and the corresponding post-prandial integrated gastric acidity. There was also a significant correlation between meal-stimulated gastric secretion and integrated gastric acidity from 09.00 to 22.00 h in both subjects with gastro-oesophageal reflux disease and controls. In subjects with gastro-oesophageal reflux disease, gastric secretion and integrated gastric acidity from 09.00 to 22.00 h were significantly higher than those in controls. There was a significant correlation between oesophageal acidity and integrated gastric acidity from 09.00 to 22.00 h in subjects with gastro-oesophageal reflux disease. CONCLUSIONS As post-prandial gastric acidity is increased in subjects with gastro-oesophageal reflux disease, it seems likely that increased gastric acidity is an important aetiological factor in this disease.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Gardner JD, Rodriguez-Stanley S, Robinson M, Miner PB. Cisapride inhibits meal-stimulated gastric acid secretion and post-prandial gastric acidity in subjects with gastro-oesophageal reflux disease. Aliment Pharmacol Ther 2002; 16:1819-29. [PMID: 12269977 DOI: 10.1046/j.1365-2036.2002.01342.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND AIMS KCNQ1 potassium channels in human gastric parietal cells are thought to be involved in gastric acid secretion. As cisapride can inhibit similar channels in other tissues and is an effective treatment for nocturnal heartburn, we examined the effects of cisapride on gastric and oesophageal acidity, gastric emptying and heartburn severity in subjects with gastro-oesophageal reflux disease. METHODS Subjects (n = 11) had suffered from heartburn four times or more per week for at least 6 months. Gastric pH and oesophageal pH were measured before, during and after a standard meal ingested over 15 min. Each subject received placebo or 10 mg cisapride orally, 30 min before the beginning of the meal. Meal-stimulated gastric acid secretion was calculated from the amount of HCl required to titrate the homogenized standard meal to pH 2 in vitro and the time required for the pH of the ingested meal to decrease to pH 2 in vivo. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Gastric emptying of solids was measured using a [(13)C]-octanoic acid breath test. RESULTS Cisapride significantly decreased meal-stimulated gastric acid secretion by 20%, decreased integrated gastric and oesophageal acidity by 50-60% and transiently increased the expiration of (13)CO(2). Cisapride did not significantly alter heartburn severity. CONCLUSIONS The cisapride-induced decreases in meal-stimulated gastric acid secretion, gastric acidity and oesophageal acidity in subjects with gastro-oesophageal reflux disease can account for its beneficial clinical effects. These results also raise the possibility that gastric KCNQ1 potassium channels are important in meal-stimulated gastric acid secretion and possibly in the pathophysiology of gastro-oesophageal reflux disease.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Abstract
BACKGROUND No standard methods exist for determining the onset of action of gastric antisecretory agents in human subjects. METHODS Intragastric pH was measured when placebo, ranitidine 150 mg, ranitidine 75 mg or famotidine 10 mg were administered 30 min after the end of a meal. RESULTS When the onset of action was defined as the earliest time that mean gastric pH with active treatment was statistically significantly higher (P < 0.05) than the corresponding placebo value, the onsets of action of ranitidine 75 mg and 150 mg were 55 min, and of famotidine 10 mg, 90 min. When onset was defined in terms of a particular decrease in gastric acid concentration for the group as a whole or for individual subjects, there was an important variation in the relative times of onset of ranitidine 75 mg and famotidine 10 mg. CONCLUSIONS When administered after a meal, the onset of action of ranitidine and famotidine on gastric pH can be determined for individual subjects as well as for the group as a whole. When onset was determined for the group using statistical significance, which does not depend on arbitrary cut-off points, ranitidine 75 mg had an earlier onset of action than did famotidine 10 mg.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, NJ 07928, USA.
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Abstract
BACKGROUND Integrated gastric and oesophageal acidity can be calculated from measurements of gastric and oesophageal pH and used to quantify gastric and oesophageal acidity over time. Rabeprazole is a new proton pump inhibitor that is effective in treating gastro-oesophageal reflux disease (GERD). AIM To use measurement of integrated gastric and oesophageal acidity to determine the onset, duration and overall effect of rabeprazole in subjects with GERD. METHODS Subjects with GERD were required to have oesophageal pH less-than-or-equal 4 for at least 10% of a 24-h recording. Effects of 20 mg rabeprazole on 24-h gastric and oesophageal pH were measured on days 1 and 7 of dosing. Integrated gastric and oesophageal acidity were calculated from time-weighted average hydrogen ion concentrations at each second of the 24-h record. RESULTS At steady-state, 20 mg rabeprazole inhibited gastric acidity by 89% and oesophageal acidity by 95%. The first dose of rabeprazole inhibited gastric and oesophageal acidity by at least 70% of the steady-state effect. Oesophageal acidity could be divided into monophasic and biphasic patterns, and rabeprazole had different effects on oesophageal and gastric acidity in these two GERD subpopulations. The onset of action of the first dose of rabeprazole on gastric acidity was 4 h and on oesophageal acidity was 4 h in monophasic subjects and 7 h in biphasic subjects. Integrated acidity was more sensitive than time pH less-than-or-equal 4 in measuring the inhibitory actions of rabeprazole. CONCLUSIONS Integrated gastric and oesophageal acidity are quantitative measurements that provide useful and novel information regarding the pathophysiology of GERD as well as the impact of antisecretory agents such as rabeprazole.
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Affiliation(s)
- J D Gardner
- Science for Organizations Inc., Chatham, NJ 07928, USA.
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Robinson M, Rodriguez-Stanley S, Ciociola AA, Filinto J, Zubaidi S, Miner PB, Gardner JD. Synergy between low-dose ranitidine and antacid in decreasing gastric and oesophageal acidity and relieving meal-induced heartburn. Aliment Pharmacol Ther 2001; 15:1365-74. [PMID: 11552907 DOI: 10.1046/j.1365-2036.2001.01058.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The pathophysiology of recurrent postprandial heartburn and the basis for the effectiveness of antacids or low doses of histamine H2-receptor antagonists have not been well studied. METHODS The selected subjects (n=26) had heartburn more than four times a week for at least 2 months, which was responsive to antacids. Gastric pH and oesophageal pH were measured for 1 h before, during, and 4.5 h after ingestion of a meal over 0.5 h. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Each subject randomly received placebo, 75 mg ranitidine, 420 mg calcium carbonate, and ranitidine plus calcium carbonate. Values for pH were converted to acid concentration (mM) and integrated acidity was calculated from the cumulative, time-weighted means of the acid concentrations for every second of the postprandial recording period. RESULTS There was a close temporal relationship between heartburn and oesophageal acidity. Most oesophageal acid exposure occurred over a 90-min period that began approximately 45 min after the end of the meal. During this period the gastric acid concentration was less than 5% of maximal. Ranitidine significantly decreased gastric but not oesophageal acidity, whilst antacid significantly decreased oesophageal but not gastric acidity. Ranitidine plus antacid significantly decreased both gastric and oesophageal acidity. Antacid alone and ranitidine plus antacid significantly decreased heartburn severity. CONCLUSIONS Determining integrated gastric and oesophageal acidity provides novel information regarding the pathophysiology of meal-induced heartburn as well as the actions of low-dose ranitidine and antacid. For subjects with meal-induced heartburn, treatment with low-dose ranitidine plus antacid is particularly effective in decreasing gastric and oesophageal acidity as well as heartburn severity.
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Affiliation(s)
- M Robinson
- Oklahoma Foundation for Digestive Research, University of Oklahoma Health Sciences Center, Oklahoma City, USA
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Abstract
OBJECTIVES The aim of this study was to demonstrate that integrated esophageal and gastric acidity values, calculated from 24-h pH recordings, can provide more precise quantitative temporal data than the conventional pH parameters historically associated with gastroesophageal reflux disease (GERD) investigations. METHODS Esophagogastroduodenoscopy results and pH tracings from 20 GERD subjects with > or =10% esophageal acid contact time were studied. Integrated gastric and esophageal acidity were calculated from time-weighted average hydrogen ion concentrations at each second of the 24-h recording period. RESULTS Integrated esophageal acidity correlated with grade of esophagitis. Two quite distinct GERD subtypes were identified, with either a monophasic or biphasic pattern of integrated esophageal acidity. "Biphasic" subjects differed from "monophasic" subjects in terms of magnitude and pattern of integrated esophageal acidity. Although both groups had significant integrated nocturnal gastric acidity, only the biphasic GERD subjects had concomitant increases in nocturnal integrated esophageal acidity. Esophagitis grade was correlated with magnitude rather than pattern of integrated esophageal acidity, and it was possible to calculate a reflux coefficient that seems to provide an estimate of the quantitative motor disturbance present in GERD. CONCLUSIONS Integrated esophageal and gastric acidity provide quantitative measures of GERD pathophysiology and, compared to conventional pH parameters, should enhance evaluation of therapeutic interventions.
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Affiliation(s)
- J D Gardner
- Science for Organizations, Inc., Chatham, New Jersey, USA
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Gardner JD, Robson DA, Rees LH, Mountford P. Titanium tert-butyl- and trimethylsilyl-imido complexes with monopendant arm triazacyclononane ligands. Inorg Chem 2001; 40:820-4. [PMID: 11225131 DOI: 10.1021/ic0009728] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J D Gardner
- Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
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Howland LC, Gortmaker SL, Mofenson LM, Spino C, Gardner JD, Gorski H, Fowler MG, Oleske J. Effects of negative life events on immune suppression in children and youth infected with human immunodeficiency virus type 1. Pediatrics 2000; 106:540-6. [PMID: 10969100 DOI: 10.1542/peds.106.3.540] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To evaluate the association of negative stressful life events experienced over 12 months and the risk of moderate to severe immune suppression among children and youth infected with human immunodeficiency virus type 1 (HIV-1). METHODS Longitudinal study of 618 HIV-1-infected children, baseline ages 1 to 20 years (mean age: 6.4 years), who completed 52 weeks of participation in the Pediatric Late Outcomes Study (Pediatric AIDS Clinical Trials Group Protocol 219). Severity of immune suppression was indicated by the Centers for Disease Control and Prevention Pediatric HIV Disease Classification System, based on CD4 percentages. The total number of negative life events-categorized as none, 1, or >1 life event reported as having occurred in the previous 12 months (previous 6 months for children <3 years of age)-was the predictor variable. Multiple logistic regressions were estimated to assess the relationship of negative life events and immune suppression at outcome, controlling for baseline measures of immune suppression, continuous CD4%, negative life events, age, race/ethnicity, gender, primary caretaker, education level of caretaker, and acquired immunodeficiency syndrome status. RESULTS At week 52, 379 subjects (61% of total study population) had moderate to severe immune suppression. Of 275 children with normal immune function at baseline, 68 (24.7%) subsequently developed moderate to severe suppression levels by week 52 of follow-up. Of 343 children with immune suppression at baseline, 32 (9.2%) had recovered to normal CD4% levels by week 52. More than 1 negative life event was associated with an increased risk (prevalence) of immune suppression (odds ratio [OR]: 2.76; 95% confidence interval [CI]: 1.44,5.31), controlling for baseline CD4%, total life events, and other covariates. Children without immune suppression at baseline who experienced >1 negative life event had an increased incidence of immune suppression (OR: 2.93; 95% CI: 1.34,6.39), controlling for baseline covariates. CONCLUSIONS Results indicate that negative stressful life events increase the risk of children with HIV-1 infection having impaired immune function. Further research is needed to identify potential mechanisms of the relationship between stressful life events and impaired immune function. These mechanisms include psychoneuroendocrinologic response and difficulties in adherence to therapy after exposure of a child to major negative life events.
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Affiliation(s)
- L C Howland
- Center for Biostatistics in AIDS Research, Harvard School of Public Health, Boston, Massachusetts, USA.
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30
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Abstract
Adolescent growth and development may be affected by factors such as dietary intake and body size from much earlier in childhood. In a longitudinal study of 67 Caucasian girls in Boston, Massachusetts, data were collected prospectively from birth during the 1930s and 1940s. Heights and weights were measured semiannually, and dietary history interviews were conducted with mothers. Stepwise linear regression methods were used to seek factors which best predicted age at menarche, adolescent peak height growth velocity, and the age at which peak growth velocity occurred. Girls who consumed more (energy-adjusted) animal protein and less vegetable protein at ages 3-5 years had earlier menarche, and girls aged 1-2 years with higher dietary fat intakes and girls aged 6-8 years with higher animal protein intakes became adolescents with earlier peak growth. Controlling for body size, girls who consumed more calories and animal protein 2 years before peak growth had higher peak growth velocity. These findings may have implications regarding adult diseases whose risks are associated with adolescent growth and development factors.
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Affiliation(s)
- C S Berkey
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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31
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Abstract
OBJECTIVE The purpose of this study was to evaluate the contribution of capacitative calcium influx to intracellular calcium levels during agonist-induced stimulation of vascular smooth muscle cells. METHODS Aortic vascular smooth muscle cells (A7r5) were loaded with Indo-1 and intracellular calcium transients were measured. Cells were challenged with either arginine vasopressin (0. 5 microM) or thapsigargin (1 microM). Lanthanum (1 mM) was used to block capacitative calcium influx through store-operated channels. Calcium traces were analyzed for basal, peak and plateau responses. Recordings were derivatized and integrated to gain additional information. Nonlinear regression provided a time constant that describes restoration of ionic equilibrium involving both sequestration and extrusion pathways. RESULTS Stimulation of cells with thapsigargin produced a non-L-type calcium influx that was attenuated by lanthanum. Cells excited with vasopressin exhibited a rapid calcium increase followed by a gradual decrease to a plateau level. Lanthanum pretreatment prior to stimulation caused no significant change in baseline, peak or plateau calcium levels as compared to control. Lanthanum caused no significant change in maximal calcium release rate, calcium integrals or time constant as compared to control. CONCLUSIONS Capacitative calcium entry can occur in vascular smooth muscle cells, but does not appear to contribute significantly to the vasopressin response.
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Affiliation(s)
- J D Gardner
- Department of Physiology, University of South Alabama, Mobile, AL 36688USA
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Stein RE, Bauman LJ, Epstein SG, Gardner JD, Walker DK. How well does the questionnaire for identifying children with chronic conditions identify individual children who have chronic conditions? Arch Pediatr Adolesc Med 2000; 154:447-52. [PMID: 10807293 DOI: 10.1001/archpedi.154.5.447] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The Questionnaire for Identifying Children With Chronic Conditions (QuICCC) is an instrument based on a conceptual noncategorical definition that uses parental responses to identify children with chronic conditions for epidemiological purposes. OBJECTIVES To determine whether the QuICCC is sufficiently valid, sensitive, and specific to be used to identify individual children as having a chronic condition or disability; whether parents are accurate enough that their answers to QuICCC items can be accepted as valid; and what kinds of errors in classification occur when the QuICCC is used to identify children with chronic conditions. METHODS The sample consisted of 424 children who were patients of 9 physicians in separate practice settings throughout New England. Each physician was briefly trained in the conceptual definition on which the QuICCC is based and then was asked to identify 25 children in his or her practice who met the definition and 25 children who did not meet the definition. The QuICCC was administered to the parents of these children by blinded interviewers via telephone. The QuICCC classification was compared with physician categorization. Discrepant cases were then followed up by asking physicians and parents to answer the original questions a second time. RESULTS Complete data were available on 379 (89.4%) of 424 children. There was agreement on 89% (kappa = 0.78). The sensitivity was 94%; specificity, 83%; positive predictive value, 86%; and negative predictive value, 92%. Of the 42 discordant cases, 30 parent reports on the QuICCC qualified the child as having a chronic condition when the physician classified the child as being without such a condition. Fewer (n = 12) discrepancies occurred because physicians identified children with chronic conditions that the QuICCC failed to identify. When the questions were readministered at follow-up, physicians corrected errors in rating in 9 cases; mothers changed their answers in 5 instances. In 13 instances the issues were known to both parties and appeared to arise in the "gray zone" or boundary area, where there was disagreement over whether a particular child qualified using the theoretical definition. For 11 children identified as having a chronic condition only by the parent's responses to the QuICCC, physician report appeared to be inaccurate primarily due to the physician's lack of information. In 3 cases where the physician reported the child to have a chronic condition, but the parent did not, the physician appeared to be correct. Follow-up data were incomplete on 1 child. CONCLUSIONS These data support the validity of parent-generated information for the evaluation of health status. Although these findings should be replicated, this study suggests that the QuICCC may be applicable also as a screening tool for individual child identification, provided that several sources of error are considered.
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Affiliation(s)
- R E Stein
- Department of Pediatrics, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10467, USA
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Blum RE, Wei EK, Rockett HR, Langeliers JD, Leppert J, Gardner JD, Colditz GA. Validation of a food frequency questionnaire in Native American and Caucasian children 1 to 5 years of age. Matern Child Health J 1999; 3:167-72. [PMID: 10746756 DOI: 10.1023/a:1022350023163] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE To assess the validity of the Harvard Service Food Frequency Questionnaire (HFFQ) in the diet assessment of Native American and Caucasian children 1 to 5 years of age participating in the North Dakota WIC program. METHODS The 84-item HFFQ was administered twice to the parent or guardian of 131 Native American and 102 Caucasian children ages 1 to 5 years (total n = 233), first at the child's routine WIC visit and then following the completion of three 24-hr dietary recalls taken over approximately 1 month. Average nutrient intakes from the three 24-hr dietary recalls were compared to average nutrient intakes from the HFFQs by calculating Pearson correlation coefficients and adjusting for energy intake and within person variation. RESULTS Correlation coefficients ranged from 0.26 for dietary fiber to 0.63 for magnesium. The average correlation was 0.52, similar to that found in validation studies among adolescents and adults. The following nutrients had correlations of 0.50 or greater: carbohydrate, sucrose, total fat, vitamin C, vitamin E, vitamin B1, vitamin B2, niacin, folate, vitamin B6, calcium, magnesium, and iron. CONCLUSIONS The HFFQ is a simple self-administered questionnaire completed by the child's parent or guardian and is useful in assessing the diets of Native American and Caucasian children. It may also provide important nutritional information about this age group for future program planning, research, education, and intervention purposes.
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Affiliation(s)
- R E Blum
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA.
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Luheshi GN, Gardner JD, Rushforth DA, Loudon AS, Rothwell NJ. Leptin actions on food intake and body temperature are mediated by IL-1. Proc Natl Acad Sci U S A 1999; 96:7047-52. [PMID: 10359836 PMCID: PMC22051 DOI: 10.1073/pnas.96.12.7047] [Citation(s) in RCA: 282] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Leptin regulates energy balance through its actions in the brain on appetite and energy expenditure and also shares properties with cytokines such as IL-1. We report here that leptin, injected into rats intracerebroventricularly or peripherally, induces significant dose-dependent increases in core body temperature as well as suppression of appetite. Leptin failed to affect food intake or body temperature in obese (fa/fa) Zucker rats, which posses a defective leptin receptor. Furthermore, injection of leptin increased levels of the proinflammatory cytokine IL-1beta in the hypothalamus of normal Sprague-Dawley rats. Central injection of IL-1 receptor antagonist (IL-1ra) inhibited the suppression of food intake caused by central or peripheral injection of leptin (60 and 84%, respectively) and abolished the leptin-induced increase in body temperature in both cases. Mice lacking (gene knockout) the main IL-1 receptor (80 kDa, R1) responsible for IL-1 actions showed no reduction in food intake in response to leptin. These data indicate that leptin actions in the brain depend on IL-1, and we show further that the effect of leptin on fever, but not food intake, is abolished by a cyclooxygenase inhibitor. Thus, we propose that in addition to its role in body weight regulation, leptin may mediate neuroimmune responses via actions in the brain dependent on release of IL-1 and prostaglandins.
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Affiliation(s)
- G N Luheshi
- School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom
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35
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Abstract
BACKGROUND Breast carcinoma risk may be modified by early life factors, including physical growth and development, diet, and life-style factors of preadolescence and adolescence, as well as genetic factors. METHODS The authors tested their hypothesis that adolescent growth and development are related to breast carcinoma incidence by evaluating 65,140 women who participated in the Nurses' Health Study. During 16 years of follow-up, 806 women were diagnosed with breast carcinoma prior to menopause, and another 1485 were diagnosed after menopause. Because adolescent growth was not directly observed in this cohort, the peak height growth velocity for each participant was estimated by using a model from another longitudinal study. Finally, Cox proportional hazards regression models were used to study associations between breast carcinoma incidence and adolescent factors in the Nurses' Health Study. RESULTS Later menarche (relative risk [RR] = 0.52 for > or =15 vs. < or =11 years) and more body fatness at age 10 years (RR = 0.60 for fattest vs. leanest) were associated with a decreased risk of premenopausal breast carcinoma. The risk of postmenopausal breast carcinoma was lower for girls with later menarche (RR = 0.80), more body fat at age 10 years (RR = 0.72), and shorter adult height (RR = 1.29 for > or =67 vs. < or =62 inches). Higher peak height growth velocity, derived from these 3 variables, was associated with increased risk of both premenopausal (RR = 1.31 for highest vs. lowest quintile) and postmenopausal (RR = 1.40) breast carcinoma. These analyses controlled for birth cohort, other possible risk factors from the adolescent period, and family history. These associations persisted after controlling for age at the birth of a first child, parity, adult adiposity, and age at menopause. Post-hoc analyses suggested that, although childhood body fatness was associated with lower risk, increasing body fatness between ages 10 and 20 years was not protective against either premenopausal or postmenopausal breast carcinoma. CONCLUSIONS Earlier menarche, extremely lean body mass at age 10 years, and taller adult height were predictive of elevated breast carcinoma risk. The same three factors were also predictive of higher peak growth velocities during adolescence, lending credence to the hypothesis that more rapid adolescent growth may increase the risk of breast carcinoma development.
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Affiliation(s)
- C S Berkey
- Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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Abstract
The present study assesses the effects of the phosphodiesterase inhibitor IBMX on norepinephrine (NE)-induced constriction of small mesenteric arteries. Arteries ( approximately 150 micrometer) were dissected from rats and mounted on a wire myograph for isometric force measurement. NE concentration effect curves were generated after exposure to 500 microM IBMX for 60 min. IBMX significantly reduced NE-induced tension development. Studies were also conducted following sarcoplasmic reticulum (SR) depletion (ryanodine, 10 microM) or L-type Ca2+ channel blockade [(+)-BAY K 8644, 10 microM] in the presence and absence of IBMX. Both SR depletion and L-channel blockade reduced NE-induced tension generation, consistent with incomplete Ca2+ mobilization. IBMX significantly attenuated NE responses in ryanodine and (+)-BAY K 8644-treated vessels. Finally, treatment of NE-stimulated vessels with IBMX (500 microM) caused a reduction in vascular tension that was greater than the concomitant reduction in cytosolic Ca2+ concentration ([Ca2+]i), indicating that a portion of the IBMX-mediated relaxation is Ca2+-independent. These data suggest that IBMX attenuation of NE responsiveness not only involves a reduction in [Ca2+]i but also a significant decrease in Ca2+ sensitivity.
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MESH Headings
- 1-Methyl-3-isobutylxanthine/pharmacology
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Calcium Channel Blockers/pharmacology
- Calcium Channels/physiology
- Calcium Channels, L-Type
- In Vitro Techniques
- Kinetics
- Male
- Mesenteric Arteries/drug effects
- Mesenteric Arteries/physiology
- Muscle Contraction/drug effects
- Muscle Contraction/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Norepinephrine/pharmacology
- Rats
- Rats, Sprague-Dawley
- Ryanodine/pharmacology
- Sarcoplasmic Reticulum/drug effects
- Sarcoplasmic Reticulum/physiology
- Time Factors
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
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Affiliation(s)
- M S Taylor
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama 36688, USA
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37
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Abstract
Previous modeling efforts suggest that myoglobin-facilitated diffusion contributes very little to oxygen transport in a Krebs-Henseleit perfused isolated heart when literature-derived values for the diffusion coefficient of myoglobin (DMb) were used. Simulations have strongly suggested that the contractile mechanisms of muscle may augment diffusion in working preparations. Myoglobin-facilitated oxygen diffusion may be augmented by the same mechanism. In this study, parameters of an oxygen transport to tissue model are optimized to investigate the possibility of elevated diffusion coefficients for oxygen and myoglobin in working heart tissue. The Radially-Averaged, Axially-Distributed (RAAD) model considers axial diffusion of oxygen in tissue, myoglobin facilitation of oxygen transport, and pO2-dependent oxygen consumption (Michaelis-Menten kinetics). Models are solved numerically using a variable-mesh finite-difference scheme. Parameters are optimized using a Nelder-Mead simplex routine and are chosen to minimize the sum-of-squares error (SSE) between model oxygen partial pressure (pO2) predictions and experimental pO2 data. Models are solved both with and without myoglobin facilitation. Myoglobin was found to have little effect on the oxygen distribution predicted by the models. Optimized values for the oxygen diffusion coefficient remained elevated. However, optimized values for myoglobin diffusion coefficient were found to be less than measured values. The RAAD model optimization results suggest that myoglobin does not significantly facilitate oxygen diffusion to tissue in the steady state and that myoglobin diffusion is not elevated in working heart.
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Affiliation(s)
- J D Gardner
- Biomedical Engineering Department, Louisiana Tech University, Ruston, Louisiana 71272-0046, USA.
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Chen GD, Lin LY, Gardner JD, Yeh NH, Wu GS. Dynamic displacement changes of the bladder neck with the patient supine and standing. J Urol 1998; 159:754-7. [PMID: 9474141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE With the patient standing and supine we determine the differences in dynamic changes of the bladder neck and directions of dynamic bladder neck displacement. MATERIALS AND METHODS To evaluate the dynamic movement of the bladder neck we recruited into the study 78 consecutive women 27 to 69 years old with various urogynecological complaints. The anatomical changes of the bladder neck from rest to maximal straining and from rest to holding were evaluated and compared with the patients supine and standing. RESULTS Except for bladder neck rotational angle with the patient standing, all parameters were significantly different from corresponding measurements with the patient supine. Mean rotational angle of rest to maximal straining plus or minus standard deviation was 39.4 +/- 18.9 degrees when standing versus 39.8 +/- 23.4 degrees when supine (p > 0.05). The distances between the bladder neck and symphysis pubis at rest, and during maximal straining and holding the bladder neck in the supine position were significantly longer than those in the standing position. The direction of bladder neck displacement from rest to maximal straining was more caudad and ventral when standing. The bladder neck moved cephalad and ventral when the patient was standing, and cephalad and dorsal with the patient supine and holding the bladder neck. CONCLUSIONS The anatomical locations and dynamic displacements of the bladder neck at rest, and during maximal straining and holding were significantly different in the supine and standing positions. While evaluating the dynamic motion of the bladder neck to determine bladder neck mobility, patient position must be considered and specified in accordance with diagnostic standards.
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Affiliation(s)
- G D Chen
- Department of Obstetrics and Gynecology, Chung Shan Medical and Dental College Hospital, Taiwan, Republic of China
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Abstract
PURPOSE We evaluated urinary frequency related to pelvic adhesions around the bladder serosa and the result of laparoscopic adhesiolysis on intractable urinary frequency caused by adhesions that did not respond to conservative treatment. MATERIALS AND METHODS Laparoscopic adhesiolysis was performed for the diagnosis and treatment of 10 referred patients with a history of pelvic surgery in whom conservative treatment had failed. Urinary symptoms and signs, a urinary diary and cystometry were followed before and after surgery. RESULTS In all cases there were various degrees of pelvic adhesion, mainly around the bladder. Frequency and urgency were improved in 9 of 10 patients. Urinary diary and cystometry parameters showed improvement at followup. CONCLUSIONS Adhesions involving the bladder wall may restrict bladder distension in most of these patients. Laparoscopic adhesiolysis is beneficial in the diagnosis and treatment of this subgroup of patients.
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Affiliation(s)
- G D Chen
- Department of Obstetrics and Gynecology, Chung Shan Medical and Dental College Hospital, Taichung, Taiwan, Republic of China
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41
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Abstract
Facilitation of oxygen transport by myoglobin has been assessed by many researchers. Yet, the models used in these studies often assume that radial diffusion is the primary transport mechanism in tissue. Axial diffusion is typically neglected. In this study, oxygen transport by myoglobin facilitation is added to a proven cardiac tissue model which contains axial diffusion in the tissue and capillary regions, the Radially-Averaged, Axially-Distributed (RAAD) model. Previous research has shown that the axial diffusion in the capillary and tissue regions becomes coupled, causing a reduction in the pO2 at the capillary inlet. The objective is to determine if this coupling effect increases the facilitation of oxygen transport by myoglobin. The RAAD model consists of non-interacting cylinders of tissue (Krogh cylinders), with each perfused by a central capillary. Derivation of the equations describing the RAAD model yields a stiff, fourth-order, non-linear, ODE, BVP. The equation set is solved numerically. Parameters for myoglobin concentration and diffusion coefficient are chosen to maximize myoglobin facilitation. The effect of myoglobin is assessed by observing changes in the pO2 profiles for the model with and without myoglobin. Also, the RAAD model is compared to experimental pO2 data to determine if the inclusion of myoglobin improves the model prediction. The computer simulations show that myoglobin does facilitate diffusion, but only to a small extent. The changes in the capillary pO2 profiles for the model with and without myoglobin are not significant, pO2 reductions are 0.8% at the inlet and 2% at the outlet. The model prediction is not substantially improved with the addition of myoglobin. The sum of squared error is reduced by 0.1%, from 5.6834 without myoglobin, to 5.6779 with myoglobin. The steady state solution of the RAAD model with myoglobin suggests that, in the presence of axial diffusion, facilitation of oxygen diffusion to tissue is not myoglobin's primary function. No conclusion can be made about the transient function of myoglobin.
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Affiliation(s)
- J D Gardner
- Biomedical Engineering Department, Louisiana Tech University, Ruston 71272, USA
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Abstract
Recently, a variety of studies in vivo as well as in vitro have demonstrated that gastrointestinal hormones can influence the rate of proliferation of neoplastic cells. The widespread use of omeprazole, which increases serum gastrin, coupled with the findings that omeprazole causes gastric carcinoid tumors in rats and that a significant number of patients with adenocarcinoma of the colon have increased serum gastrin have focussed attention on the relationship between gastrin and colon cancer. In the present paper, we have reviewed the experimental findings in humans, experimental animals, and colon cancer cells in tissue culture that bear on the possible relationships between gastrin and colon cancer. Based on these findings, we have proposed two hypotheses that can account for the increased serum gastrin that occurs in some patients with colon cancer.
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Affiliation(s)
- S N Joshi
- Department of Internal Medicine, Saint Louis University Health Sciences Center, MO 63104, USA
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Bastani B, Yang L, Baldassare JJ, Pollo DA, Gardner JD. Cellular distribution of isoforms of protein kinase C (PKC) in pancreatic acini. Biochim Biophys Acta 1995; 1269:307-15. [PMID: 7495885 DOI: 10.1016/0167-4889(95)00120-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
As in a previous study (Biochim, Biophys. Acta 1224 (1994) 127-138), we used quantitative immunoblot analysis and found that rat pancreatic acini possess four different isoforms of PKC-alpha, delta, epsilon and zeta. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) caused translocation of each isoform from the cytosol to the membrane fraction. CCK-8 increased diacylglycerol (DAG) and caused translocation of PKC-sigma and PKC-epsilon but not that of PKC-alpha or PKC-zeta. L-364,718, a CCK receptor antagonist, prevented as well as reversed the effects of CCK-8 on DAG and on translocation of PKC-sigma and PKC-epsilon. To explore the possibility that different isoforms of PKC might have different distributions in rat pancreas, we used immunocytochemistry to determine the cellular distribution of different isoforms of PKC in intact pancreas as well as pancreatic acini. In intact pancreas, PKC-alpha and PKC-sigma were detected in islet cells but not in duct or acinar cells. PKC-epsilon was detected in the apical region of acinar cells and PKC-zeta was detected over the luminal surfaces of acinar cells and the ductules that extend from the acinus. Neither PKC-epsilon nor PKC-zeta was detected in islets. In pancreatic acini PKC-alpha and PKC-sigma were detected in islets or fragments of islets that contaminated the preparation but were not detected in acinar cells. PKC-epsilon was detected in the apical region of acinar cells and adding 1 microM TPA or 1 microM CCK-8 accentuated the immunostaining but did not alter its cellular distribution. L-364,718 reversed the changes in immunostaining caused by CCK-8. PKC-zeta was detected over the luminal surface of the acinar cells. TPA, but not CCK-8 or CCK-8 followed by L-364,718, increased the number of acini that showed staining of the luminal surfaces of acinar cells. Thus, the present results demonstrate that different isoforms of PKC are distributed differently in rat pancreas and that the different patterns of distribution can explain, at least in part, the different responses to CCK-8.
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Affiliation(s)
- B Bastani
- Division of Nephrology, Saint Louis University Health Sciences Center, MO 63104, USA
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Huang SC, Talkad VD, Fortune KP, Jonnalagadda S, Severi C, Delle Fave G, Gardner JD. Modulation of cholecystokinin activity by albumin. Proc Natl Acad Sci U S A 1995; 92:10312-6. [PMID: 7479774 PMCID: PMC40786 DOI: 10.1073/pnas.92.22.10312] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We found that a variety of cholecystokinin (CCK) receptor ligands bind to bovine serum albumin (BSA). This binding was rapid, fully reversible, temperature independent, of low affinity, and specific for BSA; it depended on the concentration of BSA, the chemical structure of the ligand, and the chemical composition of the incubation medium. BSA also decreased the binding of 125I-labeled CCK octapeptide (125I-CCK-8) to CCK receptors on pancreatic acini and membranes but increased the potency with which CCK-8 inhibited binding of 125I-CCK-8. These counterintuitive findings appeared to result from BSA altering the affinities of CCK-8 for different affinity states of the pancreatic CCK receptor. An alternate hypothesis is that BSA increased the efficacy of CCK-8 such that it bound to receptors and also caused biochemical changes in other receptors that reduced their ability to bind 125I-CCK-8. BSA enhanced the ability of CCK-8 to stimulate amylase secretion from pancreatic acini and to cause contraction of dispersed gastric smooth muscle cells. Thus, CCK can bind to BSA, and the BSA-CCK complex has substantially different activities from the free, uncomplexed hormone.
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Affiliation(s)
- S C Huang
- Department of Internal Medicine, St. Louis University Health Sciences Center, MO 63104, USA
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Gardner JD, Barbarash RA. The Internet and the Journal. N Engl J Med 1995; 333:1078; author reply 1079-80. [PMID: 7675056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Huang SC, Fortune KP, Wank SA, Kopin AS, Gardner JD. Multiple affinity states of different cholecystokinin receptors. J Biol Chem 1994; 269:26121-6. [PMID: 7929324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We transfected COS cells with cDNA for rat cholecystokinin-A (CCK-A) and different CCK-B receptors and measured binding of 125I-CCK-8, [3H]L-364,718 and [3H]L-365,260 to characterize the different affinity states for each type of CCK receptor. Rat CCK-A and CCK-B receptors, canine CCK-B receptors and canine mutant CCK-B (M-CCK-B) receptors in which the leucine in position 355 was replaced by valine each existed in three different affinity states for CCK-8, high affinity, low affinity, and very low affinity. In rat CCK-A and probably CCK-B receptors, most were in the very low affinity state, whereas with canine CCK-B and M-CCK-B receptors, most were in the low affinity state. Studies with CCK receptor agonists, CCK-8, gastrin, and CCK-JMV-180, in conjunction with CCK receptor antagonists, L-364,718 and L-365,260, showed a different pattern of affinities for these ligands at the different CCK receptors. Thus, each transfected CCK receptor can exist in three different affinity states for CCK-8 and has a characteristic pattern of interaction with different ligands. This ability to exist in multiple affinity states is an intrinsic property of the CCK receptor molecule itself.
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Affiliation(s)
- S C Huang
- Department of Internal Medicine, St. Louis University Health Sciences Center, Missouri 63104
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Talkad VD, Patto RJ, Metz DC, Turner RJ, Fortune KP, Bhat ST, Gardner JD. Characterization of the three different states of the cholecystokinin (CCK) receptor in pancreatic acini. Biochim Biophys Acta 1994; 1224:103-16. [PMID: 7524683 DOI: 10.1016/0167-4889(94)90118-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
By measuring binding of [125I]CCK-8 and [3H]L-364,718 to rat pancreatic acini we demonstrated directly that the pancreatic CCK receptor can exist in three different affinity states with respect to CCK--high affinity, low affinity and very low affinity. Binding of [125I]CCK-8 reflects interaction of the tracer with the high and low affinity states, whereas binding of [3H]L-364,718 reflects interaction of the tracer with the low and very low affinity states. Treating acini with carbachol abolished the high affinity state of the CCK receptor and converted approximately 25% of the low affinity receptors to the very low affinity state. Carbachol treatment was particularly useful in establishing the values of Kd for the high and low affinity states for different CCK receptor agonists and antagonists. Of the various CCK receptor agonists tested, CCK-8 had the highest affinity for the high affinity state (Kd approximately 1 nM), whereas CCK-JMV-180 had the highest affinity for the low (Kd 7 nM) and very low affinity (Kd 200 nM) states. Gastrin and de(SO4)CCK-8 had affinities for the high and low affinity states of the receptor that were 100- to 400-fold less than those of CCK-8 but had affinities for the very low affinity state that were only 3- to 10-fold less than that of CCK-8. CCK receptor antagonists showed several patterns in interacting with the different states of the CCK receptor. L-364,718 had the same affinity for each state of the CCK receptor. CR1409 and Bt2cGMP each had similar affinities for the high and low affinity states and lower affinity for the very low affinity state. L-365,260 and CCK-JMV-179 had the highest affinity for the low affinity state and lower affinities for the high and very low affinity states. Different CCK receptor agonists caused the same maximal stimulation of amylase secretion but showed different degrees of amplification in terms of the relationship between their abilities to stimulate amylase secretion and their abilities to occupy the low affinity state of the CCK receptor. When amplification was expressed quantitatively as the value of Kd for the low affinity state divided by the corresponding EC50 for stimulating amylase secretion the values were CCK-8 (1000), de(SO)CCK-8 (1500), gastrin (100) and CCK-JMV-180 (Menozzi, D., Vinayek, R., Jensen, R.T. and Gardner, J.D. (1991) J. Biol. Chem. 266, 10385-1091).(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- V D Talkad
- Department of Internal Medicine, Saint Louis University, Health Sciences Center, MO 63104
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Pollo DA, Baldassare JJ, Honda T, Henderson PA, Talkad VD, Gardner JD. Effects of cholecystokinin (CCK) and other secretagogues on isoforms of protein kinase C (PKC) in pancreatic acini. Biochim Biophys Acta 1994; 1224:127-38. [PMID: 7524684 DOI: 10.1016/0167-4889(94)90120-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We used rat pancreatic acini and measured the effects of various agents on digestive enzyme secretion, diacylglycerol (DAG) and the cellular distribution of protein kinase C (PKC) enzyme activity as well as isoforms of PKC determined by quantitative immunoblot analysis. TPA, but not CCK-8, caused translocation of PKC enzyme activity from the cytosol fraction to the membrane fraction. Immunoblot analysis detected PKC-alpha, PKC-delta, PKC-epsilon and PKC-zeta. PKC-beta, PKC-gamma and PKC-eta were not detected. TPA caused translocation of all isoforms from cytosol to membrane, whereas CCK-8 caused translocation of PKC-delta and PKC-epsilon, carbachol caused translocation of PKC-epsilon, and bombesin and secretin caused no detectable translocation of any isoform. Specific receptor antagonists could prevent, as well as reverse completely, the translocation of PKC isoforms caused by CCK-8 or carbachol. Agonists added in sequence with an interposed addition of a specific receptor antagonist caused cycling of PKC-epsilon between cytosol and membrane fractions. Each receptor-mediated agonist that caused translocation of PKC also increased DAG, and with CCK-8 and carbachol cycling of PKC-epsilon between cytosol and membrane was accompanied by corresponding cyclic changes in cellular DAG. CCK-JMV-180, bombesin and secretin increased DAG but did not cause translocation of any PKC isoform. Translocation of a PKC isoform could be accounted for by whether the increased DAG originated from PIP2 (accompanied by translocation) or from phosphatidylcholine (no accompanying translocation). Thus it appeared that DAG, in pancreatic acini, is functionally compartmentalized depending on the source of the lipid. Studies using CCK-8 and CCK-JMV-180 indicated that occupation of the low affinity state of the CCK receptor by either peptide increased DAG from phosphatidylcholine, whereas occupation of the very low affinity state by CCK-8 increased DAG from PIP2 and caused translocation of PKC-delta and PKC-epsilon. TPA stimulated amylase secretion, indicating that activation of PKC can stimulate enzyme secretion; however, with the various receptor-mediated secretagogues there was no consistent, unequivocal correlation between translocation of an isoform of PKC and accompanying changes in enzyme secretion.
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Affiliation(s)
- D A Pollo
- Department of Internal Medicine, Saint Louis University Health Sciences Center, MO 63104
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Pandya PK, Huang SC, Talkad VD, Wank SA, Gardner JD. Biochemical regulation of the three different states of the cholecystokinin (CCK) receptor in pancreatic acini. Biochim Biophys Acta 1994; 1224:117-26. [PMID: 7948036 DOI: 10.1016/0167-4889(94)90119-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We used rat pancreatic acini and measured binding of [125I]CCK-8 and [3H]L-364,718 to the three different states of the CCK receptor to examine potential biochemical regulation of ligand binding for each receptor state. Binding of [125I]CCK-8 to the high affinity state of the receptor was measured as carbachol-inhibitable binding of [125I]CCK-8, whereas binding of [125I]CCK-8 to the low affinity state was measured as carbachol-resistant binding of [125I]CCK-8. Interaction of CCK-8 with the very low affinity state of the CCK receptor was measured as CCK-8-inhibitable binding of [3H]L-364,718. [125I]CCK-8 that was bound to the high affinity state dissociated slowly at a rate of 0.20%/min and this dissociation was not altered by 30 mM NaF. Dissociation of [125I]CCK-8 bound to the low affinity state was biphasic--22% of the bound radioactivity dissociated completely within 3 min and the remaining 78% dissociated slowly at a rate of 0.19%/min. Dissociation of [125I]CCK-8 from the low affinity state was not altered by 30 mM NaF. The pattern of dissociation of bound [125I]CCK-8 from the pancreatic CCK receptor expressed in COS cells was also biphasic and closely resembled that observed in pancreatic acini. CCK-8 that was bound to the very low affinity state dissociated completely during a 20-min period of washing and resuspension of acini that had been first incubated with CCK-8. We found extensive biochemical regulation of the different states of the CCK receptor in pancreatic acini. Bombesin, TPA, NaF, CCCP and trifluoperazine each altered binding of [125I]CCK-8 to the high affinity state and to the low affinity state, and except for bombesin each agent was more potent in affecting the high affinity state than the low affinity state. No agent tested affected the low affinity state but not the high affinity state. In contrast, a number of agents affected the high affinity state but not the low affinity state. These included receptor-mediated agonists (carbachol, secretin, VIP), 8Br-cAMP, NEM, agents that affect microtubules or microfilaments (cytochalasin B, vinblastine), calmodulin inhibitors (W-7, chlorpromazine) and genistein. Experiments with EGTA, A23187 and thapsigargin indicated that none of the three receptor states was influenced by intracellular or extracellular calcium. No agent tested altered the interaction of CCK-8 with the very low affinity state of the CCK receptor.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- P K Pandya
- Department of Internal Medicine, Saint Louis University Health Sciences Center, MO 63104
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