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Chrysostomou D, Roberts LA, Marchesi JR, Kinross JM. Gut Microbiota Modulation of Efficacy and Toxicity of Cancer Chemotherapy and Immunotherapy. Gastroenterology 2023; 164:198-213. [PMID: 36309208 DOI: 10.1053/j.gastro.2022.10.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [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: 04/29/2022] [Revised: 10/02/2022] [Accepted: 10/16/2022] [Indexed: 01/31/2023]
Abstract
Accumulating evidence supports not only the functional role of the gut microbiome in cancer development and progression but also its role in defining the efficacy and toxicity of chemotherapeutic agents (5-fluorouracil, cyclophosphamide, irinotecan, oxaliplatin, gemcitabine, methotrexate) and immunotherapeutic compounds (anti-programmed death-ligand 1/anti-programmed cell death protein 1 and anti-cytotoxic T-lymphocyte-associated antigen 4). This evidence is supported in numerous in vitro, animal, and clinical studies that highlight the importance of microbial mechanisms in defining therapeutic responses. The microbiome therefore shapes oncologic outcomes and is now being leveraged for the development of novel personalized therapeutic approaches in cancer treatment. However, if the microbiome is to be successfully translated into next-generation oncologic treatments, a new multimodal model of the oncomicrobiome must be conceptualized that incorporates gut microbial cometabolism of pharmacologic agents into cancer care. The objective of this review is therefore to outline the current knowledge of oncologic pharmacomicrobiomics and to describe how the multiparametric functions of the gut microbiome influence treatment response across cancer types. The secondary objective is to propose innovative approaches for modulating the gut microbiome in clinical environments that improve therapy efficacy and diminish toxic effects derived from antineoplastic agents for patient benefit.
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Affiliation(s)
- Despoina Chrysostomou
- Centre for Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Lauren A Roberts
- Centre for Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Julian R Marchesi
- Centre for Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - James M Kinross
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
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Alexander JL, Mullish BH, Danckert NP, Liu Z, Olbei ML, Saifuddin A, Torkizadeh M, Ibraheim H, Blanco JM, Roberts LA, Bewshea CM, Nice R, Lin S, Prabhudev H, Sands C, Horneffer-van der Sluis V, Lewis M, Sebastian S, Lees CW, Teare JP, Hart A, Goodhand JR, Kennedy NA, Korcsmaros T, Marchesi JR, Ahmad T, Powell N. The gut microbiota and metabolome are associated with diminished COVID-19 vaccine-induced antibody responses in immunosuppressed inflammatory bowel disease patients. EBioMedicine 2023; 88:104430. [PMID: 36634565 PMCID: PMC9831064 DOI: 10.1016/j.ebiom.2022.104430] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/07/2022] [Accepted: 12/16/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Patients with inflammatory bowel disease (IBD) treated with anti-TNF therapy exhibit attenuated humoral immune responses to vaccination against SARS-CoV-2. The gut microbiota and its functional metabolic output, which are perturbed in IBD, play an important role in shaping host immune responses. We explored whether the gut microbiota and metabolome could explain variation in anti-SARS-CoV-2 vaccination responses in immunosuppressed IBD patients. METHODS Faecal and serum samples were prospectively collected from infliximab-treated patients with IBD in the CLARITY-IBD study undergoing vaccination against SARS-CoV-2. Antibody responses were measured following two doses of either ChAdOx1 nCoV-19 or BNT162b2 vaccine. Patients were classified as having responses above or below the geometric mean of the wider CLARITY-IBD cohort. 16S rRNA gene amplicon sequencing, nuclear magnetic resonance (NMR) spectroscopy and bile acid profiling with ultra-high-performance liquid chromatography mass spectrometry (UHPLC-MS) were performed on faecal samples. Univariate, multivariable and correlation analyses were performed to determine gut microbial and metabolomic predictors of response to vaccination. FINDINGS Forty-three infliximab-treated patients with IBD were recruited (30 Crohn's disease, 12 ulcerative colitis, 1 IBD-unclassified; 26 with concomitant thiopurine therapy). Eight patients had evidence of prior SARS-CoV-2 infection. Seventeen patients (39.5%) had a serological response below the geometric mean. Gut microbiota diversity was lower in below average responders (p = 0.037). Bilophila abundance was associated with better serological response, while Streptococcus was associated with poorer response. The faecal metabolome was distinct between above and below average responders (OPLS-DA R2X 0.25, R2Y 0.26, Q2 0.15; CV-ANOVA p = 0.038). Trimethylamine, isobutyrate and omega-muricholic acid were associated with better response, while succinate, phenylalanine, taurolithocholate and taurodeoxycholate were associated with poorer response. INTERPRETATION Our data suggest that there is an association between the gut microbiota and variable serological response to vaccination against SARS-CoV-2 in immunocompromised patients. Microbial metabolites including trimethylamine may be important in mitigating anti-TNF-induced attenuation of the immune response. FUNDING JLA is the recipient of an NIHR Academic Clinical Lectureship (CL-2019-21-502), funded by Imperial College London and The Joyce and Norman Freed Charitable Trust. BHM is the recipient of an NIHR Academic Clinical Lectureship (CL-2019-21-002). The Division of Digestive Diseases at Imperial College London receives financial and infrastructure support from the NIHR Imperial Biomedical Research Centre (BRC) based at Imperial College Healthcare NHS Trust and Imperial College London. Metabolomics studies were performed at the MRC-NIHR National Phenome Centre at Imperial College London; this work was supported by the Medical Research Council (MRC), the National Institute of Health Research (NIHR) (grant number MC_PC_12025) and infrastructure support was provided by the NIHR Imperial Biomedical Research Centre (BRC). The NIHR Exeter Clinical Research Facility is a partnership between the University of Exeter Medical School College of Medicine and Health, and Royal Devon and Exeter NHS Foundation Trust. This project is supported by the National Institute for Health Research (NIHR) Exeter Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NIHR or the UK Department of Health and Social Care.
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Affiliation(s)
- James L Alexander
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; Department of Gastroenterology and Hepatology, Imperial College Healthcare NHS Trust, London, United Kingdom.
| | - Benjamin H Mullish
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; Department of Gastroenterology and Hepatology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Nathan P Danckert
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Zhigang Liu
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Marton L Olbei
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Aamir Saifuddin
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; St Mark's Hospital and Academic Institute, Harrow, London, United Kingdom
| | - Melissa Torkizadeh
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; King's College London, London, United Kingdom
| | - Hajir Ibraheim
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; Department of Gastroenterology and Hepatology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Jesús Miguéns Blanco
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Lauren A Roberts
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | | | - Rachel Nice
- University of Exeter, Exeter, Devon, United Kingdom; Department of Gastroenterology, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, United Kingdom
| | - Simeng Lin
- University of Exeter, Exeter, Devon, United Kingdom; Department of Gastroenterology, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, United Kingdom
| | - Hemanth Prabhudev
- Department of Gastroenterology and Hepatology, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Caroline Sands
- National Phenome Centre, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Verena Horneffer-van der Sluis
- National Phenome Centre, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Matthew Lewis
- National Phenome Centre, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Shaji Sebastian
- Hull University Teaching Hospitals NHS Trust, Gastroenterology, Hull, United Kingdom; University of Hull, Hull York Medical School, Hull, United Kingdom
| | - Charlie W Lees
- Western General Hospital, Edinburgh, United Kingdom; The University of Edinburgh Centre for Genomic and Experimental Medicine, Edinburgh, United Kingdom
| | - Julian P Teare
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Ailsa Hart
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; St Mark's Hospital and Academic Institute, Harrow, London, United Kingdom
| | - James R Goodhand
- University of Exeter, Exeter, Devon, United Kingdom; Department of Gastroenterology, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, United Kingdom
| | - Nicholas A Kennedy
- University of Exeter, Exeter, Devon, United Kingdom; Department of Gastroenterology, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, United Kingdom
| | - Tamas Korcsmaros
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; Earlham Institute, Norwich, United Kingdom; Quadram Institute Bioscience, Norwich, United Kingdom
| | - Julian R Marchesi
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Tariq Ahmad
- University of Exeter, Exeter, Devon, United Kingdom; Department of Gastroenterology, Royal Devon and Exeter NHS Foundation Trust, Exeter, Devon, United Kingdom
| | - Nick Powell
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom; Department of Gastroenterology and Hepatology, Imperial College Healthcare NHS Trust, London, United Kingdom.
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3
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Mullish BH, Martinez-Gili L, Chekmeneva E, Correia GDS, Lewis MR, Horneffer-Van Der Sluis V, Roberts LA, McDonald JAK, Pechlivanis A, Walters JRF, McClure EL, Marchesi JR, Allegretti JR. Assessing the clinical value of faecal bile acid profiling to predict recurrence in primary Clostridioides difficile infection. Aliment Pharmacol Ther 2022; 56:1556-1569. [PMID: 36250604 DOI: 10.1111/apt.17247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/30/2022] [Accepted: 09/26/2022] [Indexed: 01/30/2023]
Abstract
BACKGROUND Factors influencing recurrence risk in primary Clostridioides difficile infection (CDI) are poorly understood, and tools predicting recurrence are lacking. Perturbations in bile acids (BAs) contribute to CDI pathogenesis and may be relevant to primary disease prognosis. AIMS To define stool BA dynamics in patients with primary CDI and to explore signatures predicting recurrence METHODS: Weekly stool samples were collected from patients with primary CDI from the last day of anti-CDI therapy until recurrence or, otherwise, through 8 weeks post-completion. Ultra-high performance liquid chromatography-mass spectrometry was used to profile BAs. Stool bile salt hydrolase (BSH) activity was measured to determine primary BA bacterial deconjugation capacity. Multivariate and univariate models were used to define differential BA trajectories in patients with recurrence versus those without, and to assess faecal BAs as predictive markers for recurrence. RESULTS Twenty (36%) of 56 patients (median age: 57, 64% male) had recurrence; 80% of recurrences occurred within the first 9 days post-antibiotic treatment. Principal component analysis of stool BA profiles demonstrated clustering by recurrence status and post-treatment timepoint. Longitudinal faecal BA trajectories showed recovery of secondary BAs and their derivatives only in patients without recurrence. BSH activity increased over time only among non-relapsing patients (β = 0.056; likelihood ratio test p = 0.018). A joint longitudinal-survival model identified five stool BAs with area under the receiver operating characteristic curve >0.73 for predicting recurrence within 9 days post-CDI treatment. CONCLUSIONS Gut BA metabolism dynamics differ in primary CDI patients between those developing recurrence and those who do not. Individual BAs show promise as potential novel biomarkers to predict CDI recurrence.
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Affiliation(s)
- Benjamin H Mullish
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK.,Departments of Gastroenterology and Hepatology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Laura Martinez-Gili
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK.,Section of Bioinformatics, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Elena Chekmeneva
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, National Phenome Centre, IRDB Building, Hammersmith House Campus, Imperial College London, London, UK.,Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Gonçalo D S Correia
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, National Phenome Centre, IRDB Building, Hammersmith House Campus, Imperial College London, London, UK.,Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Matthew R Lewis
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, National Phenome Centre, IRDB Building, Hammersmith House Campus, Imperial College London, London, UK.,Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Verena Horneffer-Van Der Sluis
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, National Phenome Centre, IRDB Building, Hammersmith House Campus, Imperial College London, London, UK.,Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.,Department for Diagnostics, Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Lauren A Roberts
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK
| | - Julie A K McDonald
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Alexandros Pechlivanis
- Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.,Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Biomic_Auth, Bioanalysis and Omics Laboratory, Center for Interdisciplinary Research and Innovation (CIRI-AUTH), Thessaloniki, Greece
| | - Julian R F Walters
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK.,Departments of Gastroenterology and Hepatology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Emma L McClure
- Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Julian R Marchesi
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK
| | - Jessica R Allegretti
- Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
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4
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Ghani R, Mullish BH, Roberts LA, Davies FJ, Marchesi JR. The potential utility of fecal (or intestinal) microbiota transplantation in controlling infectious diseases. Gut Microbes 2022; 14:2038856. [PMID: 35230889 PMCID: PMC8890388 DOI: 10.1080/19490976.2022.2038856] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
The intestinal microbiota is recognized to play a role in the defense against infection, but conversely also acts as a reservoir for potentially pathogenic organisms. Disruption to the microbiome can increase the risk of invasive infection from these organisms; therefore, strategies to restore the composition of the gut microbiota are a potential strategy of key interest to mitigate this risk. Fecal (or Intestinal) Microbiota Transplantation (FMT/IMT), is the administration of minimally manipulated screened healthy donor stool to an affected recipient, and remains the major 'whole microbiome' therapeutic approach at present. Driven by the marked success of using FMT in the treatment of recurrent Clostridioides difficile infection, the potential use of FMT in treating other infectious diseases is an area of active research. In this review, we discuss key examples of this treatment based on recent findings relating to the interplay between microbiota and infection, and potential further exploitations of FMT/IMT.
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Affiliation(s)
- Rohma Ghani
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Benjamin H. Mullish
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Lauren A. Roberts
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Frances J. Davies
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Julian R. Marchesi
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
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Nel P, Roberts LA, Hoffmann R. Carbapenemase-producing Enterobacteriaceae colonisation in adult inpatients: A point prevalence study. S Afr J Infect Dis 2019; 34:129. [PMID: 34485459 PMCID: PMC8377780 DOI: 10.4102/sajid.v34i1.129] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/08/2019] [Indexed: 11/01/2022] Open
Abstract
Background Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) have been increasing worldwide in recent years, but data regarding the prevalence and clinical significance of CPE colonisation in South Africa is not well documented. Local private hospital groups have implemented routine screening programmes for selected high-risk patients as endorsed by the South African Society for Clinical Microbiology. This practice is not routinely performed in the public sector. Methods A point prevalence study was performed at Tygerberg Hospital (TBH) by screening patients of all the adult inpatient wards to investigate the current prevalence of CPE colonisation. Common risk factors associated with CPE colonisation were also investigated. Results From a total of 439 patient samples collected, only one patient was colonised with a Klebsiella pneumoniae organism harbouring blaNDM-1. The identified patient had none of the common risk factors associated with CPE colonisation. Conclusion Based on these findings, screening for CPE colonisation in adults on admission to TBH is currently not recommended.
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Affiliation(s)
- Pieter Nel
- Division of Medical Microbiology, Department of Pathology, Tygerberg Medical Campus, Stellenbosch University, Cape Town, South Africa.,Medical Microbiology Laboratory, Tygerberg Hospital, National Health Laboratory Service, Cape Town, South Africa
| | - Lauren A Roberts
- Division of Medical Microbiology, Department of Pathology, Tygerberg Medical Campus, Stellenbosch University, Cape Town, South Africa
| | - Rena Hoffmann
- Division of Medical Microbiology, Department of Pathology, Tygerberg Medical Campus, Stellenbosch University, Cape Town, South Africa.,Medical Microbiology Laboratory, Tygerberg Hospital, National Health Laboratory Service, Cape Town, South Africa
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Roberts LA, Ling HZ, Poon LC, Nicolaides KH, Kametas NA. Maternal hemodynamics, fetal biometry and Doppler indices in pregnancies followed up for suspected fetal growth restriction. Ultrasound Obstet Gynecol 2018; 52:507-514. [PMID: 29607557 DOI: 10.1002/uog.19067] [Citation(s) in RCA: 32] [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] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 03/18/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
OBJECTIVES To assess whether, in a cohort of patients with a small-for-gestational-age (SGA) fetus with estimated fetal weight ≤ 10th percentile, maternal hemodynamics, fetal biometry and Doppler indices at presentation can predict the subsequent development of an abnormal fetal Doppler index or delivery of a baby with birth weight < 3rd percentile. METHODS This was a prospective observational cohort study conducted at a specialist clinic for the management of pregnancies with a SGA fetus at King's College Hospital, London, UK. The study population comprised 86 singleton pregnancies with a SGA fetus, presenting at a median gestational age of 32 (range, 26-35) weeks. We measured maternal cardiac function using a non-invasive transthoracic bioreactance monitor, as well as mean arterial pressure, fetal biometry, and umbilical artery (UA), fetal middle cerebral artery (MCA) and uterine artery (UtA) pulsatility indices (PI), and the deepest vertical pool of amniotic fluid. Z-scores of these variables were calculated based on reported reference ranges and the values were compared between pregnancies with evidence of an abnormal fetal Doppler index at presentation (Group 1), those that had developed an abnormal Doppler index at a subsequent visit (Group 2) and those that did not develop an abnormal Doppler index throughout pregnancy (Group 3). Abnormal fetal Doppler was defined as UA-PI > 95th percentile and/or MCA-PI < 5th percentile. Differences in measured variables at presentation were also compared between pregnancies delivering a baby with birth weight < 3rd percentile and those delivering a baby with birth weight ≥ 3rd percentile. Multivariate logistic regression analysis was used to determine significant predictors of birth weight < 3rd percentile and evolution from normal to abnormal fetal Doppler. RESULTS In the study population, 14 (16%) cases were in Group 1, 19 (22%) in Group 2 and 53 (62%) in Group 3. Birth weight was < 3rd percentile in 39 (45%) cases and ≥ 3rd percentile in 47 (55%). There was decreased cardiac output and stroke volume and increased peripheral vascular resistance compared with a normal population, and the deviations from normal were most marked in Group 1. Pregnancies with birth weight < 3rd percentile, compared with those with birth weight ≥ 3rd percentile, had greater deviations from normal in fetal biometry, maternal cardiac output, stroke volume, heart rate, peripheral vascular resistance and UtA-PI. Multivariate logistic regression analysis demonstrated that, in the prediction of birth weight < 3rd percentile, maternal hemodynamic profile provided significant improvement to the prediction provided by maternal demographics, fetal biometry, UtA-PI, UA-PI and MCA-PI (difference between areas under receiver-operating characteristics curves, 0.18 (95% CI, 0.06-0.29); P = 0.002). In contrast, there was no significant independent contribution from maternal hemodynamics in the prediction of the subsequent development of abnormal fetal Doppler. CONCLUSIONS In pregnancies with a SGA fetus, there is decreased maternal cardiac output and stroke volume and increased peripheral vascular resistance, and the deviations from normal are most marked in cases of redistribution in the fetal circulation and reduced amniotic fluid volume. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
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Affiliation(s)
- L A Roberts
- Fetal Medicine Research Institute, King's College London, London, UK
| | - H Z Ling
- Fetal Medicine Research Institute, King's College London, London, UK
| | - L C Poon
- Fetal Medicine Research Institute, King's College London, London, UK
- The Chinese University of Hong Kong, Hong Kong, SAR
| | - K H Nicolaides
- Fetal Medicine Research Institute, King's College London, London, UK
| | - N A Kametas
- Fetal Medicine Research Institute, King's College London, London, UK
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Abstract
Thirty-three children with a diagnosis of systemic lupus erythematosus (SLE) were studied. At diagnosis, 29 of them (88%) were aged between 10 and 17 years and the other four (12%) between 5 and 9 years. The majority were girls (28, 82%) and the male:female ratio was 1:6.6. Children of East Indian and mixed racial origin formed the largest groups (37 and 39%, respectively) and mortality was higher in these two groups. The most common symptoms at diagnosis were: fever for > 1 week (75.8%), musculoskeletal symptoms (arthralgia, arthritis and myalgia (69.7%) and renal involvement (63.6%). Malar and discoid rashes were common, 39 and 37%, respectively. Central nervous system involvement at presentation was a rare but important cause of mortality. The mortality rate during follow-up was high at 39.3% and the commonest cause of death was renal failure. Childhood SLE is uncommon in Trinidad and Tobago. Diagnosis is often delayed because of the protean and non-specific manifestations. This study reports a higher prevalence, a more severe course and greater mortality in children of East Indian and mixed descent than in children of African origin. It also shows that the symptomatology at first presentation is consistent with other studies and should be recognised early. Early diagnosis and prompt and appropriate management are essential in order to reduce the high mortality still associated with SLE.
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Affiliation(s)
- B N Balkaran
- Department of Paediatrics, Faculty of Medical Sciences, University of the West Indies, St Augustine Campus, Trinidad.
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8
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Moore BJ, Donnison IS, Harper JA, Armstead IP, King J, Thomas H, Jones RN, Jones TH, Thomas HM, Morgan WG, Thomas A, Ougham HJ, Huang L, Fentem T, Roberts LA, King IP. Molecular tagging of a senescence gene by introgression mapping of a stay-green mutation from Festuca pratensis. New Phytol 2005; 165:801-806. [PMID: 15720691 DOI: 10.1111/j.1469-8137.2004.01269.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
* Intergeneric hybrids between Lolium multiflorum and Festuca pratensis (Lm/Fp) and their derivatives exhibit a unique combination of genetic and cytogenetic characteristics: chromosomes undergo a high frequency of homoeologous recombination at meiosis; the chromosomes of the two species can easily be discriminated by genomic in situ hybridization (GISH); recombination occurs along the entire length of homoeologous bivalents; a high frequency of marker polymorphism is observed between the two species. * This combination of characters has been used to transfer and isolate a F. pratensis chromosome segment carrying a mutant 'stay-green' gene conferring a disrupted leaf senescence phenotype into L. multiflorum. * The genetic location within the introgressed F. pratensis segment of the senescence gene has been mapped using amplified fragment length polymorphisms (AFLPs), and F. pratensis-specific AFLP markers closely flanking the green gene have been cloned. * The use of these cloned sequences as markers for the stay-green locus in marker-assisted selection programmes has been tested. The potential application of Lm/Fp introgressions as a tool for the map-based cloning of introgressed Fp genes is discussed.
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Affiliation(s)
- B J Moore
- Molecular and Applied Genetics Team, Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, SY23 3EB, UK
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9
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Abstract
Whole-cell patch-clamp recordings were made from neurons in the trigeminal nucleus caudalis and trigeminal ganglion, in vitro, to investigate the cellular actions of the endogenous cannabinoid, anandamide. Anandamide has been shown to act through both the cannabinoid receptor 1 (CB1) and the vanilloid receptor 1 (VR1). Anandamide (30 microM) caused a 54 % increase in the rate of miniature excitatory post-synaptic currents (mEPSCs), without affecting their amplitude. The effect of anandamide was blocked by the VR1 antagonist capsazepine (20 microM), but not by the CB1-specific antagonist AM251 (3 microM). Application of the VR1 receptor agonist capsaicin (300 nM) caused a 4200 % increase in the mEPSC rate. In dissociated trigeminal ganglion neurons, both anandamide and capsaicin caused an outward current in neurons that were voltage clamped at +40 mV. The maximal outward current produced by anandamide (EC50, 10 microM) was 45 % of that produced by capsaicin (10 microM). Co-application of the VR1 antagonist capsazepine (30 microM) completely reversed the effects of both capsaicin and anandamide. The anandamide transport inhibitor, AM404 (30 microM) caused a 40 % increase in mEPSC rate in the slice preparation and an outward current in dissociated neurons. The latter current was reversed by the VR1 antagonist iodoresiniferatoxin (1 microM). The fatty acid amide hydrolase (FAAH) inhibitors phenylmethylsulfonyl fluoride (PMSF) (20 microM) and OL53 (1 microM) did not enhance the effect of anandamide in either the slice or dissociated neuron preparations. These results suggest that within the superficial medullary dorsal horn, anandamide (30 microM) acts presynaptically to enhance the release of glutamate via activation of the VR1 receptor.
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Affiliation(s)
- E A Jennings
- Department of Pharmacology, The University of Sydney, NSW, Australia.
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10
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King J, Armstead IP, Donnison IS, Thomas HM, Jones RN, Kearsey MJ, Roberts LA, Thomas A, Morgan WG, King IP. Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis. Genetics 2002; 161:315-24. [PMID: 12019245 PMCID: PMC1462087 DOI: 10.1093/genetics/161.1.315] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [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: 01/31/2023] Open
Abstract
A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1.
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Affiliation(s)
- J King
- Institute of Biological Sciences, University of Wales, Aberystwyth, SY23 3DA, Wales, United Kingdom
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11
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King J, Roberts LA, Kearsey MJ, Thomas HM, Jones RN, Huang L, Armstead IP, Morgan WG, King IP. A demonstration of a 1:1 correspondence between chiasma frequency and recombination using a Lolium perenne/Festuca pratensis substitution. Genetics 2002; 161:307-14. [PMID: 12019244 PMCID: PMC1462085 DOI: 10.1093/genetics/161.1.307] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [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: 11/12/2022] Open
Abstract
A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study chiasma formation in a single marked bivalent. Recombination occurs freely in the F. pratensis/L. perenne bivalent, and chiasma frequency counts give a predicted map length for this bivalent of 76 cM. The substituted F. pratensis chromosome was also mapped with 104 EcoRI/Tru91 and HindIII/Tru91 amplified fragment length polymorphisms (AFLPs), generating a marker map of 81 cM. This map length is almost identical to the map length of 76 cM predicted from the chiasma frequency data. The work demonstrates a 1:1 correspondence between chiasma frequency and recombination and, in addition, the absence of chromatid interference across the Festuca and Lolium centromeres.
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Affiliation(s)
- J King
- Institute of Biological Sciences, University of Wales, Aberystwyth, SY23 3DA, Wales, United Kingdom
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12
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Gidding HF, Hills S, Selvey L, Roberts LA, Johnston S. An outbreak of measles in a rural Queensland town in 1997; an opportunity to assess vaccine effectiveness. Commun Dis Intell (2018) 1999; 23:240-5. [PMID: 10554408] [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: 02/14/2023]
Abstract
This report describes a measles outbreak in a rural town in south-east Queensland and presents the results of a vaccine effectiveness (VE) study performed during this outbreak. It is important to assess the effectiveness of a vaccine in an outbreak to determine if the outbreak is due to failure of the vaccine or failure to vaccinate. There were 44 cases of measles amongst local residents, which represents a notification rate of 396.7 per 100,000 population. Case investigations identified a group of people who had been exposed to measles at a seminar. The attack rate for the seminar cohort was 18% (11/61). This presented an opportunity to conduct a VE study using data about children aged less than 16 years who attended the seminar. In this cohort of 23 attendees, all 7 children who had not received any measles vaccinations became cases whilst the 6 who were fully vaccinated for their age according to NHMRC guidelines were protected from measles illness. Although there were insufficient fully vaccinated cohort members to reliably estimate VE for this group, the vaccine was 84.6% (95% CI: 15.0-99.7%) effective for those who had received at least one validated dose of vaccine. Despite the sample size limitations, the results support the view that failure to vaccinate rather than vaccine failure contributed to the high infection rate in the seminar cohort.
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Affiliation(s)
- H F Gidding
- Communicable Diseases Unit, Queensland Health, Brisbane
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13
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Skull SA, Morris PS, Yonovitz A, Attewell RG, Krause V, Leach AJ, Anand A, Scott J, Reid S, Roberts LA. Middle ear effusion: rate and risk factors in Australian children attending day care. Epidemiol Infect 1999; 123:57-64. [PMID: 10487642 PMCID: PMC2810729 DOI: 10.1017/s0950268899002708] [Citation(s) in RCA: 11] [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: 11/07/2022] Open
Abstract
There have been no previous longitudinal studies of otitis media conducted in non-Aboriginal Australian children. This paper describes the rate and risk factors for middle ear effusion (MEE) in children attending day care in Darwin, Australia. A prospective cohort study of 252 children under 4 years was conducted in 9 day care centres over 12 fortnights between 24 March and 15 September 1997. Tympanometry was conducted fortnightly and multivariate analysis used to determine risk factors predicting MEE. The outcome of interest was the rate of type B tympanograms per child detected in either ear at fortnightly examinations. After adjusting for clustering by child, MEE was detected on average 4.4 times in 12 fortnights (37% of all examinations conducted). Risk factors associated with presence of effusion were younger age, a family history of ear infection, previous grommets (tympanostomy tubes), ethnicity and the day care centre attended. A history of wheeze appeared protective. These effects were modest (RR 0.57-1.70). Middle ear effusion is very common in children attending day care in Darwin. This has clinical importance, since MEE during early childhood may affect optimal hearing, learning and speech development. There is little scope for modification for many of the risk factors for MEE predicted by this model. Further study of the day care environment is warranted.
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Affiliation(s)
- S A Skull
- Centre for Disease Control Darwin, Territory Health Services, Casuarina, NT, Australia
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14
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Abstract
BACKGROUND Following the 1996 discovery of a rabies-like lyssavirus in Australian flying foxes, it was unclear whether this was a new epizootic or an unrecognised, previously existing disease. OBJECTIVE To review cases of unexplained encephalitis in the Northern Territory (NT) to test available clinical specimens for lyssavirus and survey the use of diagnostic tests by clinicians. METHODS The NT hospital morbidity database was searched from January 1992 to September 1996 for all Royal Darwin Hospital (RDH) cases with an ICD-9 code encompassing encephalitis or viral meningitis. Final diagnoses were determined by hospital record review. For cases of unexplained encephalitis, we assessed the use of diagnostic tests and located clinical specimens for testing for lyssavirus-specific inclusion bodies via immunohistochemistry, immunofluorescence and reverse-transcriptase polymerase chain reaction (RT-PCR). RESULTS Encephalitis occurred in 34/154 (22%) cases located by the search; 53% (18/34) of encephalitis cases were unexplained. Of these, 24% had no serology performed and 47% had no blood cultures taken. Four (22%) died and two had autopsies. These were the only two cases with clinical specimens available for testing. They were negative for lyssavirus. None of the 71 cases coded as viral meningitis had unexplained encephalitis. CONCLUSION There was a considerable proportion of unexplained illness among NT cases of encephalitis. IMPLICATIONS Clinicians should test for lyssavirus in patients with encephalitic symptoms and a postmortem should be sought where death is unexplained. Specimens should be stored to enable testing for emerging infectious diseases.
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Affiliation(s)
- S A Skull
- Centre for Disease Control, Northern Territory, Australian National University, Australian Capital Territory.
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15
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Metz JA, Morris CD, Roberts LA, McClung MR, McCarron DA. Blood pressure and calcium intake are related to bone density in adult males. Br J Nutr 1999; 81:383-8. [PMID: 10615210] [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: 02/15/2023]
Abstract
Based on the premise that elevated blood pressure and low bone mass have both been associated with poor Ca nutriture and disturbances in Ca metabolism, a cross-sectional study was employed to determine if blood pressure and dietary Ca intake were significantly related to bone mass. Forty-seven men between 24-77 years of age with blood pressure values ranging from normal to mildly elevated comprised the study group. Blood pressure was measured with a random-zero sphygmomanometer. Bone mineral content (BMC) and density (BMD) of the hip, spine and total body were measured with dual-photon absorptiometry. Dietary intake and physical activity were also assessed. Multiple linear regression analysis was used for statistical analysis. After adjusting for known confounding variables (age, BMI, Ca intake, and others) diastolic blood pressure was negatively related to BMC (P < or = 0.05) and BMD (P < or = 0.01) of the total body, trochanteric region (P < 0.01) and Ward's triangle (P < 0.05), and to BMC of the femoral neck (P < 0.05) and lumbar spine, although the latter was just shy of statistical significance (P = 0.058). Systolic blood pressure was negatively related to trochanteric BMD (P = 0.04) and BMC (P = 0.06). Ca intake was positively related to total body BMD (P = 0.005), and BMC of the lumbar spine (P = 0.05). In this population of men, Ca intake was a positive predictor, and blood pressure was a negative predictor of regional measures of bone mass. These findings support the concept that independent of age, BMI and Ca intake, elevated blood pressure varies indirectly with bone mass and density, known predictors of osteoporotic fractures. Future studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass, and what role dietary Ca plays in that pathway.
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Affiliation(s)
- J A Metz
- Department of Medicine, Oregon Health Sciences University, Portland, USA.
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16
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Skull SA, Krause V, Coombs G, Pearman JW, Roberts LA. Investigation of a cluster of Staphylococcus aureus invasive infection in the top end of the Northern Territory. Aust N Z J Med 1999; 29:66-72. [PMID: 10200815 DOI: 10.1111/j.1445-5994.1999.tb01590.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Staphylococcus aureus invasive infection remains a serious condition associated with considerable morbidity and mortality. Following notification of five cases at Royal Darwin Hospital (RDH), we searched for related cases, determined their epidemiological characteristics and attempted to identify the source of this apparent cluster. METHODS We reviewed RDH microbiology records between June 1996 and April 1997 for S. aureus isolates with similar antibiograms to notified cases. We used antibiotic resistance patterns, bacteriophage typing and two molecular typing techniques to subtype implicated isolates. Hospital records were reviewed for admission details and associated costs were estimated. RESULTS Fifty-four cluster-related isolates occurred in 47 separate presentations. The peak incidence was in the wet season. The most important risk factor for staphylococcal invasive infection was the presence of skin sores/scabies in 17/54 cases (31%), followed by intravascular line use in 14/54 (26%), open trauma in 11/54 (20%), underlying end stage renal failure and alcoholism each in ten of 54 (18%). The mean admission length was 30 days and antibiotics were given for an average of 23 days. Death due to S. aureus infection occurred in eight of 47 (17%) presentations. S. aureus pneumonia was community acquired in 12/13 patients (92%) and six of 13 (46%) died. Ten of 13 (80%) pneumonia patients had at least one other focus of S. aureus infection. The cost of antibiotics and hospital bed per presentation was approximately $16,000. Presentations with skin sores/scabies cost considerably more ($31,000). No common epidemiologic features were found for community or hospital acquired cases. CONCLUSION Considerable mortality and cost was attributable to cases of S. aureus invasive infection during this cluster; particularly those with community acquired pneumonia or skin sores/scabies. Staphylococcal antibiotic cover should be considered early for unwell patients presenting to hospital with pneumonia and other signs of potential S. aureus infection. It is appropriate to target public health efforts to prevent skin sores and to provide adequate treatment when they occur.
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17
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Abstract
The case histories of two Afro-Trinidadian brothers aged 8 and 11 years who developed end-stage renal disease (ESRD) are presented. Neither had had cause in the past to seek medical attention for any renal-related illness. At presentation both had anaemia, growth failure and other clinical and laboratory evidence of ESRD. Kidney histology in one child was consistent with familial juvenile nephronophthisis (NPH). This is a common cause of ESRD in children in other countries but it has not been recognized previously in Trinidadian and other West Indian children, and should be considered as a possible aetiology in West Indian children presenting with renal failure.
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Affiliation(s)
- B Balkaran
- Department of Child Health, Eric Williams Medical Sciences Complex, University of the West Indies, Trinidad
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18
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19
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Stone TW, Roberts LA, Morris BJ, Jones PA, Ogilvy HA, Behan WM, Duley JA, Simmonds HA, Vincent MF, van den Berghe G. Succinylpurines induce neuronal damage in the rat brain. Adv Exp Med Biol 1998; 431:185-9. [PMID: 9598056 DOI: 10.1007/978-1-4615-5381-6_36] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- T W Stone
- Division of Neuroscience and Biomedical Systems, University of Glasgow, Scotland
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20
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Roberts LA, Large CH, Higgins MJ, Stone TW, O'Shaughnessy CT, Morris BJ. Increased expression of dendritic mRNA following the induction of long-term potentiation. Brain Res Mol Brain Res 1998; 56:38-44. [PMID: 9602046 DOI: 10.1016/s0169-328x(98)00026-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A small number of mRNAs, including Ca2+/calmodulin-dependent protein kinase II alpha-subunit (CamKIIalpha) mRNA and microtubule-associated protein 2 (MAP2) mRNA, are present in the dendrites of neurones as well as in the cell bodies. We show here that the induction of long-term potentiation (LTP) in the hippocampal perforant path/granule cell synapses in anaesthetised rats is associated with increased levels of CamKIIalpha mRNA and MAP2 mRNA in the granule cell dendrites after 2 h. Similarly, induction of LTP in the Schaffer collateral/CA1 pyramidal cell synapses in hippocampal slices maintained in vitro also results in elevated dendritic levels of CamKIIalpha mRNA and MAP2 mRNA 2 h later. In both models, the levels of various other mRNA species restricted to the cell body region were unaffected by the induction of LTP. Increased expression of dendritic CamKIIalpha mRNA and MAP2 mRNA appears to be a general feature of hippocampal plasticity, since it occurs following LTP induction in both the dentate gyrus and the CA1 region. The elevation of mRNA levels in a restricted region close to the afferent synapses would allow a highly-localised enhancement of the synthesis of the corresponding proteins, providing an elegant mechanism for protein-synthesis-dependent synaptic plasticity to maintain a high degree of anatomical specificity.
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Affiliation(s)
- L A Roberts
- Pharmacological laboratories, Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, West Medical Building, Glasgow University, Glasgow, UK
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21
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Abstract
Induction of long-term potentiation (LTP) in the hippocampus is associated with changes in expression of a variety of different proteins and is thought to be the mechanism which underlies synaptic plasticity. The 25 kDa synaptosomal-associated protein (SNAP-25) is a presynaptic protein which is involved in neurotransmitter exocytosis at the nerve terminal. Two isoforms of SNAP-25 have so far been identified (a and b) which differ in their distribution and developmental regulation. Using in situ hybridization, we demonstrated that the mRNA levels of the two isoforms of this protein are increased 2 h after the induction of LTP in granule cells of the dentate gyrus following high frequency stimulation of the perforant path in vivo. These observations further demonstrate the involvement of both isoforms of SNAP-25 in functional synaptic plasticity, although their exact roles have yet to be fully determined.
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Affiliation(s)
- L A Roberts
- Division of Neuroscience and Biomedical Systems, Institute for Biomedical and Life Sciences, University of Glasgow, UK
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22
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Abstract
This study was designed to determine whether smooth muscle alpha-actin mRNA and smooth muscle alpha-actin contractile protein elements were present within the renal medullary pericytes. Extraction of total RNA from microdissected outer medullary descending vasa recta allowed for the detection of smooth muscle alpha-actin mRNA expression using reverse transcription-polymerase chain reaction (RT-PCR). Expression of smooth muscle alpha-actin was specific to the descending vasa recta and not a result of tubular contamination because RT-PCR amplification of the vasopressin V2 receptor, which is a specific tubular marker, did not occur. To determine the exact cell type(s) that translate the mRNA into protein, we performed immunohistochemistry on the renal outer and inner medulla using a monoclonal smooth muscle alpha-actin antibody, whose specificity was determined by immunoblot analysis. Smooth muscle alpha-actin protein was found selectively within the pericytes surrounding the descending vasa recta from the outer and inner medullary tissue sections. This study demonstrates that the pericytes alone that surround the descending vasa recta within the outer and inner medulla contain smooth muscle alpha-actin mRNA and protein and are therefore the site of the contractile elements that could play a vasomodulatory role in the control of renal medullary blood flow and its distribution within the renal medulla.
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Affiliation(s)
- F Park
- Department of Physiology, Medical College of Wisconsin, Milwaukee 53226, USA
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23
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Roberts LA, Large CH, O'Shaughnessy CT, Morris BJ. Long-term potentiation in perforant path/granule cell synapses is associated with a post-synaptic induction of proenkephalin gene expression. Neurosci Lett 1997; 227:205-8. [PMID: 9185686 DOI: 10.1016/s0304-3940(97)00349-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 02/04/2023]
Abstract
Enkephalin peptides released from hippocampal mossy fibres lower the threshold for the generation of long-term potentiation (LTP) at the mossy fibre synapses. High frequency stimulation of the hippocampal dentate gyrus, sufficient to induce mossy fibre LTP, is associated with increased expression of the proenkephalin gene in the granule cells. We show here that a similar elevation in proenkephalin mRNA levels is observed, in anaesthetised rats, following stimulation of the perforant path sufficient to induce LTP in the perforant path/granule cell synapses. This strengthens the evidence implicating granule cell enkephalins as mediators of functional plasticity in the hippocampus. Furthermore. the results hint at a form of 'domino plasticity', where potentiation of transmission at the perforant path/granule cell synapses is subsequently followed by an enkephalin-mediated potentiation of transmission at the mossy fibre synapses.
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Affiliation(s)
- L A Roberts
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, Glasgow University, UK
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Roberts LA, Higgins MJ, O'Shaughnessy CT, Stone TW, Morris BJ. Changes in hippocampal gene expression associated with the induction of long-term potentiation. Brain Res Mol Brain Res 1996; 42:123-7. [PMID: 8915588 DOI: 10.1016/s0169-328x(96)00148-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The expression of four genes: zif/268, c-fos, tubulin and alpha Ca2+/calmodulin-dependent protein kinase II (alpha CAMKII) was studied following the induction of LTP in Schaffer collateral CA1 neurone synapses in rat hippocampal slices maintained in vitro. Levels of c-fos mRNA and tubulin (T26) mRNA in area CA1 were unchanged after induction of LTP, however, zif/268 and alpha CAMKII mRNA levels showed a significant increase compared to non-potentiated controls. It is possible, therefore, to measure changes in gene expression using in situ hybridisation following induction of LTP in vitro and these results strengthen the theory that zif/268 and alpha CAMKII are involved in some aspect of the induction or maintenance of hippocampal LTP.
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Affiliation(s)
- L A Roberts
- Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, University of Glasgow, UK
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25
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Abstract
Many studies have shown the high correlation between Lunar and Hologic DXA bone mineral density (BMD) measurements despite differences in absolute calibration. However, in clinical practice, raw BMD values (in g/cm2) are not normally used for assessing skeletal status and fracture risk. Instead, the BMD values are expressed in terms of the number of standard deviations above or below the young normal value (commonly referred to as the T-score). If the normative populations of the various systems are consistent, the standard deviation scores should also be consistent. For this reason, the World Health Organization (WHO) recently established diagnostic criteria for osteoporosis based on T-scores and not BMD. However, few studies have compared the instruments in terms of their standard deviation scores. In this study, we used linear regression to compare T-scores in 83 women at L1-4 and 120 women at the femoral neck obtained on a Lunar DPX and a Hologic QDR-1000/W system. patient BMD and T-score measurements were highly correlated between the two systems (r > 0.95). No clinically significant difference in L1-4 T-scores was seen (less than 0.1 SD). However, linear regression analysis confirmed a systematic difference of 0.9 SD between the femoral neck T-scores. This discrepancy is caused by: (1) differences in the normal populations, and (2) differences in statistical models used to determine the young normal mean and standard deviation. In an attempt to correct the discrepancy, the female young normal mean and standard deviation were recalculated for the femoral neck using published epidemiological data from NHANES and existing DXA cross-calibration equations. The Hologic young normal value (mean +/- SD) was redefined as 0.85 +/- 0.11 g/cm2, while the Lunar value was redefined as 1.00 +/- 0.11 g/cm2. When the femoral neck T-scores for the study population were recalculated on the basis of these new values, the results were equivalent between manufactures, effectively eliminating the discrepancy. However, the revised values should be confirmed by additional measurements in young normal adults.
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26
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Abstract
Though spinal and femoral measurements are typically preferred for evaluating skeletal density, an abundance of forearm data exists, primarily from single photon absorptiometry (SPA) devices. Most dual X-ray absorptiometry (DXA) scanners are capable of scanning the forearm and provide analysis tools to duplicate conventional SPA measurements. In this study, we have compared the radius density measurements from three commonly available densitometers: a Norland 278 SPA, a Lunar DPX-L, and a Hologic 1000/W. Radius bone mineral density (BMD) on the nondominant forearm was measured in 28 volunteers (21 women and 7 men) aged 24-78, with an average age of 51 +/- 17 years. Values were compared and regression relationships derived at corresponding measurement sites. SPA and DXA BMD values were found to be highly correlated (r = 0.99) with small standard errors (0.014 g/cm2-0.021 g/cm2), though significant absolute differences were observed at most measurement regions. Correlation slopes ranged from 0.85 to 1.04, with intercepts from 0.01 to 0.08 g/cm2. Using the resultant regression equations, SPA BMD values can be converted to DXA values with an expected error of roughly 3%. DXA BMD can also be interconverted between Lunar and Hologic with a similar expected error. In situations where this level of imprecision is acceptable, patient forearm measurements obtained on different systems can be interconverted.
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Affiliation(s)
- K G Faulkner
- Providence Center for Osteoporosis Research, Portland, Oregon 97213-2966
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27
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Abstract
Visual and auditory stimulus discrimination tasks, analogous to those used in the Reitan-Klove Sensory Perceptual Examination, were performed by 12 cocaine-dependent and 5 alcohol-dependent patients after 1 week, 3 weeks, and 3 months of verified abstinence. Sixteen control subjects, who were not substance-dependent, performed the same tasks after comparable intervals. During each task, either visual or auditory stimuli were presented in the left, in the right, or in both sensory fields. A simple key press was made to discriminate these conditions. Cocaine-dependent patients responded more slowly than control subjects during both tasks. The reaction-time slowing persisted across all three sessions, spanning a 3-month period of abstinence. There were no significant differences between the cocaine-dependent and control groups in response accuracy. In the context of other findings, these findings are interpreted as reflecting an enduring effect of prior cocaine dependence on motor as opposed to sensory functioning.
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Affiliation(s)
- L A Roberts
- Department of Psychiatry, University of Connecticut Health Center, Farmington
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28
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Farmer JL, Roberts LA, Rydzinski ME, Hilty MD. Human immune response to cationized proteins. II. Characterization of interaction of cationized diphtheria toxoid with human mononuclear cells. Cell Immunol 1993; 146:198-209. [PMID: 8425227 DOI: 10.1006/cimm.1993.1017] [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] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cationized diphtheria toxoid (cDT) has previously been shown to be more effective than the native protein as an inducer of human antigen-specific T cell responses. In the present study, biotin-labeled antigen and flow cytometric analysis were used to examine the possibility that enhanced immunogenicity of cDT may be a consequence of preferential binding to antigen-presenting cells. Strong binding of cDT, relative to native antigen, was noted for both monocytes and B cells. Characteristics of binding were similar for both cell types, including rapid saturation, temperature independence, and inhibition by unlabeled cationized proteins. Although both B cells and monocytes bound cDT, only monocytes were effective in triggering T cell proliferation, possibly as a result of slow internalization of bound antigen by B cells. Definition of the target structures of cationized proteins may allow for the design of more efficient vaccines, which would be specifically targeted to antigen-presenting cells in vivo.
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Affiliation(s)
- J L Farmer
- Abbott Laboratories Diagnostics Division, New Markers R&D, Abbott Park, Illinois 60064
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Farmer JL, Roberts LA, Rydzinski ME, Hilty MD. Human immune response to cationized proteins. I. Characterization of the in vitro response to cationized diphtheria toxoid. Cell Immunol 1993; 146:186-97. [PMID: 8425226 DOI: 10.1006/cimm.1993.1016] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cationization of proteins, i.e., increasing net positive charge by the substitution of carboxyl groups with positively charged residues, has been reported to enhance protein immunogenicity in animal model systems. In the present study, we have investigated the effect of cationization on the in vitro cell-mediated immune response of human mononuclear cells to diphtheria toxoid. A series of cationized DT preparations were generated by covalent modification with ethylenediamine, with pIs ranging from 4.6 to > 9.3, and tested for their ability to induce proliferation of normal human peripheral blood mononuclear cells. Cationized DT (cDT) was found to induce an antigen-specific, augmented proliferative response, relative to native antigen, which was directly proportional to the degree of cationization. Further characterization of the response to cDT demonstrated that (1) proliferative responses could be detected considerably earlier, and typically at much lower antigen concentrations, than the response to native DT; (2) the response was dependent on HLA-DR; (3) production of a number of cytokines, sp. IL-1 beta, IL-2, and IFN-gamma, was also elevated in cDT-stimulated cultures; and (4) the enhanced proliferative response to cDT could be attributed to CD4+ helper T cells. These results demonstrate that cationization of proteins enhances the ability to generate a cell-mediated immune response in humans and suggest that cationization may have utility in the design of more effective carrier proteins for human vaccines.
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Affiliation(s)
- J L Farmer
- Abbott Laboratories Diagnostics Division, New Markers R&D, Abbott Park, Illinois 60064
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Affiliation(s)
- L A Roberts
- Medical College of Wisconsin, Milwaukee 53226
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Abstract
The sinoatrial ring bundle (SARB), was originally described as a "whitish bundle of tissue which describes an almost complete loop around the two venae cavae and the coronary sinus" in the adult rabbit heart (Paes de Carvalho et al., 1959). The histologically and electrophysiologically differentiated structure, derived from the embryonic venous valves, was suitably placed for rapid conduction from sinoatrial (SA) to atrioventricular (AV) node, but no evidence was found for this role. Today, the function of the SARB remains obscure. Cholinesterase/silver staining reveals the neural pattern associated with the SARB and suggests a function. Throughout its extent, the SARB contains a bundle of parallel muscle fibers and accompanying long nerves. The nerves distribute to structures at either side of the loop: superolaterally to pectinate muscle and inferomedially to the region of the AV node. Along the curve of the right SARB, the nerves contribute to a dense neural plexus with nerves coiled around muscle. The plexus communicates with the nearby SA node and with the ganglia inferior to the node near the inferior vena cava. The morphological pattern of neural elements is suitably organized to suggest tension monitoring and internodal, neural communication.
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Affiliation(s)
- L A Roberts
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee 53226
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Abstract
The morphological innervation pattern of developing fetal and neonatal rabbit hearts was delineated histochemically by a cholinesterase/silver procedure and immunohistochemically with the monoclonal antibody HNK1, an antibody which recognizes some cells derived from neuroectoderm. Cholinesterase-containing nerves appeared distally on the outflow tract by gestational day 15 (G15). Isolated cells with cholinesterase-stained fine processes were present near the base of the pulmonary trunk. HNK1 antibody stained the same nerves and ganglia revealed by the cholinesterase reaction and other nerves in the rabbit heart. It was used to confirm that cells with fine neuron-like processes were present before nerve ingrowth. The G14 heart contained many HNK1 staining cells in the right atrium, outflow, and inflow tracts; cells with fine processes were few but increased at G16. By G17, a plexus of interweaving nerves and associated cells began to form at the base of the pulmonary trunk. Fine nerves encircled the base of the aorta, and others crossed the intercaval region dorsally. At G19, nerves 1) extended downward from a rich "bulbar" plexus along the front ventricular surface, 2) grew near the epicardial surface at the base of the heart along the atrial floor and ventricular roof, 3) traversed the vena cavae and intercaval region to enter the atrial roof, and 4) crossed the coronary sinus to reach the back ventricular walls. By G23, cholinesterase-staining nerves and ganglia in the atria and, epicardially, in the ventricles formed the general innervation pattern of the newborn and adult rabbit heart.
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Affiliation(s)
- L A Roberts
- Medical College of Wisconsin, Milwaukee 53226
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Roberts LA, Collignon PJ, Cramp VB, Alexander S, McFarlane AE, Graham E, Fuller A, Sinickas V, Hellyar A. An Australia-wide epidemic of Pseudomonas pickettii bacteraemia due to contaminated "sterile" water for injection. Med J Aust 1990; 152:652-5. [PMID: 2198444 DOI: 10.5694/j.1326-5377.1990.tb125422.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [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: 12/30/2022]
Abstract
Nineteen cases of Pseudomonas pickettii bacteraemia and one case of Pseudomonas cepacia bacteraemia were identified in an Australia-wide outbreak of nosocomial sepsis associated with contaminated water for injection. The contamination was limited to one batch of commercially produced water for injection. Four different organisms were identified (three biotypes of P. pickettii and one of P. cepacia). However, P. pickettii biotype 1 appeared to be relatively more virulent than the other biotypes as it was the only identified organism in blood cultures in nearly all cases of sepsis. The ampoules of "sterile" water were each contaminated with approximately 10(3) organisms per millilitre. The lack of an Australian central reporting system for bacteraemia delayed the recognition of this outbreak.
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Abstract
The pattern of nerves, ganglia, and fine nerve processes in the adult rabbit sinoatrial node, identified by microelectrode recording, was defined by staining histochemically for cholinesterase followed by silver impregnation. A generalized repeatable pattern of innervation was recognized, including 1) a large ganglionic complex inferior to the sinoatrial node; 2) two or three moderately large nerves traversing the sinoatrial node parallel to the crista terminalis; 3) nerves entering the region from the atrial septum, the superior vena cava, and the inferior vena cava; and 4) a fine network of nerve processes, particularly extensive in the morphologically dense small-cell part of the sinoatrial node. When the site of initial depolarization in the node was located and marked by a broken-off electrode tip, it was found, after cholinesterase staining, to be characterized by a cluster of cells enclosed in a nest or basket of fine nerves. Similar nested cell clusters were observed elsewhere in the sinoatrial node in this same preparation and in other hearts. A complex interweaving of atrial muscle fibers was observed medial and inferomedial to the sinoatrial node, which may form the anatomical basis for the lack of conduction through this region. The morphological pattern of nerves, ganglia, and myocardial cells described in this study emphasizes the complexity of innervation of the sinoatrial node, including its intrinsic neural elements. Cholinesterase/silver staining can be useful in the definition and comparison of electrophysiologically identified sites within the sinoatrial node.
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Affiliation(s)
- L A Roberts
- Department of Anatomy and Cellular Biology, Medical College of Wisconsin, Milwaukee 53226
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Sun LS, Roberts LA, Rosen MR, Robinson RB. The positive chronotropic effect of acetylcholine has muscarinic and nicotinic components in the neonatal rat heart. J Pharmacol Exp Ther 1988; 247:585-9. [PMID: 3183954] [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: 01/04/2023] Open
Abstract
Acetylcholine increases ventricular automaticity in neonatal but not adult canine Purkinje fibers. In this study, we used a rat model to investigate the mechanism for the increased automaticity, and used surface electrodes to record spontaneous rates from the ventricular septa of three different age groups: 1 to 2 days old (neonates), 6 to 9 days old (1 week old) and adults. Acetylcholine, 10(-12) and 10(-11) M, induced a significant increase in automaticity from a control of 103 +/- 6.5 beats per min to 117 +/- 9.0 and 118 +/- 10.8 beats per min, respectively, in the neonates (P less than .05). The increase was attenuated by atropine, 2 x 10(-6) M (P = .05), and eliminated by propranolol, 2 x 10(-7) M, or hexamethonium, 5 x 10(-6) M (P less than .05). In 1-week-old rats, acetylcholine, 10(-12) M, induced a lesser increase in automaticity from a control of 106 +/- 13.0 to 113 +/- 14.0 beats per min (P less than .05). The increase was blocked by atropine, 2 x 10(-6) M, propranolol, 2 x 10(-7) M, and by hexamethonium, 5 x 10(-6) M (all P less than .05). In adults, acetylcholine did not increase automaticity. Among the neonatal septa, 82% showed increased automaticity with acetylcholine alone, 78% showed increased automaticity in the presence of atropine and 13% showed increased automaticity in the presence of either propranolol or hexamethonium, suggesting a largely nicotinic mediated and catecholamine dependent component. In 1-week-old septa, 75% showed increased automaticity with acetylcholine alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L S Sun
- Department of Pharmacology, Columbia University College of Physicians & Surgeons, New York, New York
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Kim HW, Feola M, Rowley BA, Roberts LA. Effects of hemoglobin perfusion on contractile function of the isolated ventricular septa. Biomater Artif Cells Artif Organs 1988; 16:331-45. [PMID: 3179474 DOI: 10.3109/10731198809132582] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Effects of three unmodified hemoglobin solutions on myocardial contractile function was evaluated using isolated perfused rabbit interventricular septa. The hemoglobin solutions tested were: a human hemoglobin solution (SFHS-A), a bovine hemoglobin prepared by a column chromatography (SFHS-B), and a bovine hemoglobin obtained by a ultrafiltration method (SFHS-C). Myocardial effects were assessed by comparing contractile parameters; developed tension (DT), resting tension (RT), and perfusion pressure (PP), measured before (control perfusion with Tyrode buffer) and during hemoglobin perfusion. Further, to examine the effects of hemoglobin solutions on myocardial contractility following a period of impaired flow, septal responses to a 10-minute period of ischemia (stopflow) were also studied. After a 10-minute perfusion with hemoglobin solution, SFHS-C increased DT to 124 +/- 12% (paired t-test, p less than 0.05) without causing a significant increase in RT or PP while SFHS-A and SFHS-B decreased DT to 96 +/- 20% (p greater than 0.05) and to 77 +/- 7% (p less than 0.05), respectively. A significant rise in PP (40-50% above baseline) was also noted with these solutions (p less than 0.05). Similarly, after a 30-minute reperfusion following a 10-minute ischemia, SFHS-C allowed significantly better percentage recovery (95 +/- 3%) than septa perfused with SFHS-A (81 +/- 2%) or SFHS-B (63 +/- 6%) (Student's t-test, p less than 0.05). These results indicate that hemoglobin solution, if properly prepared, does not seem to have acute deleterious effects on contractile function of the isolated heart.
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Affiliation(s)
- H W Kim
- School of Medicine, Mercer University, Macon, Georgia
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Abstract
GABA agonists and antagonists were injected intrathecally at the spinal cord, to determine their effect on nociceptive thresholds. Tactile stimulation, applied against the flank by a medium diameter von Frey fiber (5.5 g force), elicited distress vocalizations after, but not before injection of the GABA antagonists, bicuculline MI or picrotoxin (0.25 and 1 microgram dosages). Vocalization threshold to tail shock was significantly reduced by bicuculline MI or picrotoxin. Tail flick withdrawal latency from radiant heat was not altered by GABA antagonists. The GABA agonist, muscimol, significantly elevated vocalization threshold to tail shock at a 5 micrograms dose. At a lower dose level (1 microgram), muscimol significantly reduced vocalization threshold to tail shock. Tail flick latency was significantly prolonged by the 5 micrograms dose of muscimol; however, flaccid paralysis of the hind limbs was also evident. Nociceptive thresholds were not altered by GABA or saline injection. These findings indicate that GABAergic activity contributes to the tonic modulation of nociception at the spinal cord.
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Patrick AL, Roberts LA, Burton EN, Jankey N, Shah DJ. Focal and segmental glomerulosclerosis in the acquired immunodeficiency syndrome. W INDIAN MED J 1986; 35:200-2. [PMID: 3776187] [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] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
Glycine or its receptor antagonist, strychnine, were administered perispinally to investigate their effect on nociceptive responses elicited by activation of various cutaneous receptors. Strychnine produced dose-dependent sensory and motor disturbances; 1 and 5 micrograms doses were sub-convulsive, eliciting recurrent episodes of coordinated grooming, scratching and biting at the skin, which persisted for approximately 10 minutes post-injection; higher doses (25 and 100 micrograms) increased the intensity and duration of these effects, and produced convulsive motor seizures. Motor disturbances were not elicited by glycine (5, 25, 100 and 400 micrograms). Strychnine treated rats, at all doses, vocalized consistently in response to light cutaneous stimulation; a significant proportion of glycine treated rats also vocalized, but were not as sensitive to mild stimulation. Skin hyperalgesia persisted for at least 30 minutes in both strychnine and glycine treated rats. Both strychnine and glycine significantly reduced vocalization thresholds to tail shock. However, no clear effect on tail flick latency was observed following either strychnine or glycine. These results indicate that glycinergic neurons contribute to the tonic regulation of nociceptive input at the spinal cord.
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Abstract
Vaginal-cervical mechanostimulation (VS) suppresses vocalization and withdrawal responses to noxious stimulation. To determine whether the inhibitory neurotransmitter, glycine, contributes to the action of VS, strychnine, a specific glycine receptor antagonist was administered perispinally via intrathecal catheter in dosages of 1,5,25 and 100 micrograms. Prior to strychnine administration, VS (400 g force) elevated thresholds to elicit vocalization in response to graded intensities of tail shock, and blocked vocalization elicited by stimulation of a skin area, previously sensitized by intradermal injection of a 20% yeast solution. After strychnine administration the analgesic effects of VS were significantly attenuated. These findings suggest that the analgesic action of VS is partially mediated by glycine at the spinal level.
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Abstract
We studied listeners' intonation sensitivity to traditional (major and minor) and nontraditional chords. The nontraditional chords have frequency ratios of 3:5:7 and 5:7:9 and, like the major chord, have coincident upper partials and unambiguous fundamental basses. The center tone only of each of these four triads was varied from its just (integer ratio) value by -30, -15, 0, +15, and +30 cents. Each tone had ten partials whose amplitudes decreased with frequency relative to the fundamental (9 dB per octave). Subjects judged which chord (or chordal sequence) of a pair was more in tune, smooth and/or pleasant. Listeners' intonation sensitivity curves exhibited regular patterns for both traditional and nontraditional chords. However, our subjects divided into two groups: One group preferred chords in just intonation and their preferences decreased monotonically as the intonation deviated from just intonation; the other group preferred intonations that deviated from just intonation by +/- 15 cents.
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Abstract
The alkali metal ions lithium, potassium, rubidium and cesium depress the rate of spontaneous beating of isolated rabbit right atria. At low concentrations (2 to 4 mM) the negative chronotropic effect was in the order: Cs greater than Rb greater than K or Li; at a higher concentration (12 mM) it was Rb or K greater than Cs or Li. Force of contraction was also depressed by potassium and cesium at all levels, but was stimulated by lithium and by low levels of rubidium (2 mM). Lithium had little chronotropic effect up to relatively high concentrations, decreasing spontaneous beating rate to 80% of control at 100 mM LiCl. The significant positive inotropic effect at 2 mM LiCl (to 120% of control) increased (to 180% of control) at 40 mM LiCl. Rate of beating was significantly depressed by 0.2 mM CsCl. The chronotropic effect of cesium was biphasic; the decrease in SBR at 2 and 4 mM cesium was greater than the negative chronotropic effect at 10 mM CsCl. The effect of rubidium (above 4 mM) closely resembled that of increased potassium in decreasing spontaneous beating rate and contractile force.
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Abstract
After a long developmental effort, we can now fabricate, using thin-film techniques, both rigid modiolar multielectrodes and flexible scala tympani multielectrodes which we believe appropriate for long-term implantation in human subjects. In vitro and in vivo life tests are in progress to confirm this expectation.
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Abstract
Spontaneously beating rabbit atria were used for study of increases in passive tension induced by hyperosmolar Tyrode bathing media. The time course and degree of passive tension change was dependent on the level of osmolality and the osmotic agent used. The effectiveness of various agents added to Tyrode solution in increasing resting tension was in the order sucrose greater than mannitol greater than or equal to NaCl greater than glucose greater than = no change. The hyperosmotically induced "contracture" was similar to contracture induced by high Ca2+ medium, but the maximum hyperosmotic effect was greater than that of high Ca2+. In contrast to active atria, inactive atria showed no increase in passive tension in hyperosmotic solutions or in Tyrode solution containing high Ca2+. After depolarization with Tyrode medium containing high K+ or zero K+, increased Ca2+ caused contracture in inactive left atria greater than that caused by hyperosmotic media (+200 mM sucrose) in active right atria or atrial pairs. Results of the study indicate that although other factors may be involved, increased Ca2+ flux inward could largely account for the passive tension response.
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Abstract
Ethanol has a positive chronotropic and negative inotropic effect on isolated spontaneously beating rabbit atria. Both effects increased with increasing ethanol concentrations in the bathing medium. This response is apparently a direct action of ethanol on the myocardium and is not due to the release of catecholamines, acetylcholine, or acetaldehyde produced by the oxidative metabolism of ethanol. Ethanol is one of the few pharmacologic agents having opposite actions on heart rate and force of contraction.
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Roberts LA. Female homosexuality. Nurs Times 1977; 74:1426-9. [PMID: 905152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Spontaneously beating rabbit atria responded to hyperosmotic Tyrode bathing media with an increase in rate, force of contraction, and passive tension dependent on the level of osmolality and the osmotic agent employed. The positive chronotropic response reached a maximum within a few minutes and then declined to a lower, maintained plateau level. The plateau change in rate was similar whether the osmotic agent added to Tyrode solution was sucrose, mannitol or NaCl. For these agents, the response increased linearly with osmotic pressure of the bathing media from 300 to 500 mosmol/kg H2O, then progressively decreased approaching zero (plateau rate = control) at about 700 mosmol/kg H2O. The chronotropic response to urea in Tyrode solution, though less than for the other three agents, progressively increased over the entire range of osmolalities tested (from 300 to 700 mosmol/kg H2O). The inotropic response was positive for all agents from 300 to 600 mosmol/kg H2O. Passive tension of atria increased with added NaCl, sucrose, or mannitol, but not with urea. Propranolol did not alter the atrial response to hyperosmolality. Thus, we find that the chronotropic response of atria to hyperosmolar solutions is positive over a wide range of agents and osmolalities, in contrast to earlier reports of a direct negative chronotropic effect.
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Roberts LA. The community psychiatric nurse. Nurs Times 1976; 72:2020-1. [PMID: 1012957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Roberts LA. Premenstrual tension syndrome. Nurs Times 1975; 71:272-3. [PMID: 1167688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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