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Pediatric Aerodigestive Medicine: Advancing Collaborative Care for Children With Oropharyngeal Dysphagia. J Pediatr Gastroenterol Nutr 2023; 77:460-467. [PMID: 37438891 DOI: 10.1097/mpg.0000000000003882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
OBJECTIVES Aerodigestive disorders encompass various pathological conditions affecting the lungs, upper airway, and gastrointestinal tract in children. While advanced care has primarily occurred in specialty centers, many children first present to general pediatric gastroenterologists with aerodigestive symptoms necessitating awareness of these conditions. At the 2021 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the aerodigestive Special Interest Group held a full-day symposium entitled, Pediatric Aerodigestive Medicine: Advancing Collaborative Care of Children with Aerodigestive Disorders. The symposium aimed to underline the significance of a multidisciplinary approach to achieve better outcomes for these complex patients. METHODS The symposium brought together leading experts to highlight the growing aerodigestive field, promote new scientific and therapeutic strategies, share the structure and benefits of a multidisciplinary approach in diagnosing common and rare aerodigestive disorders, and foster multidisciplinary discussion of complex cases while highlighting the range of therapeutic and diagnostic options. In this article, we showcase the diagnostic and therapeutic approach to oropharyngeal dysphagia (OPD), one of the most common aerodigestive conditions, emphasizing the role of a collaborative model. CONCLUSIONS The aerodigestive field has made significant progress and continues to grow due to a unique multidisciplinary, collaborative model of care for these conditions. Despite diagnostic and therapeutic challenges, the multidisciplinary approach has enabled and greatly improved efficient, high-quality, and evidence-based care for patients, including those with OPD.
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Airway obstruction and inflammation on combined bronchoscopy in children with Down syndrome. Pediatr Pulmonol 2021; 56:2932-2939. [PMID: 34245494 DOI: 10.1002/ppul.25573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/22/2021] [Accepted: 07/01/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To characterize the upper and lower airway findings in children with Down syndrome and chronic respiratory symptoms, based on evaluation by flexible bronchoscopy (FB) with bronchoalveolar lavage and microlaryngoscopy with bronchoscopy (MLB). STUDY DESIGN A retrospective review was conducted of children with Down syndrome aged 1 month to 17 years, who underwent both FB and MLB within a 1-year timeframe between 2010 and 2019 at Children's Hospital Colorado. Anatomic airway findings are reported as frequencies within the cohort. Bronchoalveolar lavage fluid (BALF) culture results, cell differential, and cytopathology are reported as frequencies or mean ± standard deviation. BALF results were compared between children with and without dysphagia documented on a recent swallow evaluation. RESULTS Overall, 168 children with Down syndrome were included, with median age of 2.1 years (interquartile range: 0.9-5.1 years). At least one abnormal airway finding was recorded in 96% of patients and 46% had at least three abnormal findings. The most common findings included tracheomalacia (39% FB; 37% MLB), subglottic stenosis (35% MLB), pharyngomalacia (32% FB), and laryngomalacia (16% FB; 30% MLB). Comparison of BALF based on dysphagia status showed that children with dysphagia had more frequent cultures positive for mixed upper respiratory flora (76% vs. 47%, p = 0.004) and a higher percentage of neutrophils (20% vs. 7%, p = 0.006). CONCLUSION Abnormal findings for FB and MLB are common in children with Down syndrome and chronic respiratory symptoms, and performing the procedures together may increase the diagnostic yield.
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Pediatric Patients' and Parents' Perspectives of Unsedated Transnasal Endoscopy in Eosinophilic Esophagitis: A Qualitative Descriptive Study. J Pediatr Gastroenterol Nutr 2021; 72:558-562. [PMID: 33394888 DOI: 10.1097/mpg.0000000000003029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Eosinophilic esophagitis is an increasingly common inflammatory disease of the esophagus. Diagnosis and management are based on the histological presence of eosinophils in the esophageal mucosa, often requiring multiple endoscopies with sedation. Unsedated transnasal endoscopy (TNE), an alternative method of assessing the mucosa without the risks of sedation, is now being performed in the pediatric population. This is the first qualitative study on pediatric patients' and parents' experiences with TNE. OBJECTIVE The objective of the study was to describe pediatric patients' and parents' experiences of TNE with the goal of refining TNE protocols to improve the clinical experience. METHODS We used a qualitative descriptive approach that included in-depth, semistructured interviews with patients and parents following completion of TNE. Interviews continued until we reached thematic saturation. We analyzed data using qualitative content analysis. RESULTS A total of 21 interviews were completed. We identified 4 themes: Appeal of TNE; Expectations and Preparation for TNE; Tolerance of TNE; and Evaluation of TNE. Perceived positive aspects of TNE were no exposure to intravenous anesthesia; helpful and clear preparation for the procedure with a demonstration video and physician phone call; distraction during TNE with virtual reality goggles and a stress ball; parent able to accompany the patient; and TNE requiring less time than an esophagogastroduodenoscopy. Negative aspects included patient stress before TNE, patient dislike of nasal spray taste and sensation, and discomfort during the TNE procedure. CONCLUSION The overall perception of TNE among our participants was positive. Study data will allow pediatric gastroenterologists the opportunity to improve both preparation for and comfort during TNE.
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Vascular and pulmonary comorbidities in children with congenital EA/TEF. Pediatr Pulmonol 2021; 56:571-577. [PMID: 33300304 DOI: 10.1002/ppul.25219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/18/2020] [Accepted: 12/02/2020] [Indexed: 11/09/2022]
Abstract
BACKGROUND Esophageal atresia with tracheoesophageal fistula (EA/TEF) is associated with many congenital and vascular malformations; however, reports utilizing computed tomography (CT) and computed tomography angiography (CTA) are limited. The objective of this study is to review CT scans of the chest from patients with EA/TEF and report their pulmonary and vascular findings. METHODS We completed a retrospective chart review of children with congenital EA/TEF evaluated in the aerodigestive clinic at Children's Hospital Colorado. Results of the most recent CTA or CT of the chest were investigated. Demographics, medical conditions, and bronchoscopy findings were also recorded. The ratio of tracheal lumen area between inspiratory and expiratory CTA images was measured. RESULTS Of the patients with congenital EA/TEF seen in the program, 47 patients had a chest CT available for review. Eight patients (17%) had bronchiectasis. Of the contrast CT scans, 15 (58%) had a vascular abnormality and 16 (62%) demonstrated tracheal compression (38% at the level of the innominate artery, 35% from other structures). Nineteen of the CTAs had volumetric expiratory images of the trachea to evaluate tracheomalacia. The mean expiratory:inspiratory area was 0.57 (SD ± 0.23) at the level of the innominate. CONCLUSION Patients with EA/TEF frequently have vascular abnormalities that may alter airway mechanics as well as pulmonary comorbidities that may affect long-term management. For patients experiencing persistent respiratory symptoms, CTA of the chest should be considered adjunct to bronchoscopy to help with medical and surgical management of these children.
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Proceedings of the 2018 Advances In Motility and In NeuroGastroenterology: AIMING for the Future Single Topic Symposium. J Pediatr Gastroenterol Nutr 2020; 71:e59-e67. [PMID: 32287151 PMCID: PMC8451965 DOI: 10.1097/mpg.0000000000002720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Motility and functional disorders are common in children and often debilitating, yet these disorders remain challenging to treat effectively. At the 2018 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the Neurogastroenterology and Motility Committee held a full day symposium entitled, 2018 Advances In Motility and In NeuroGastroenterology - AIMING for the future. The symposium aimed to explore clinical paradigms in pediatric gastrointestinal motility disorders and provided a foundation for advancing new scientific and therapeutic research strategies. METHODS The symposium brought together leading experts throughout North America to review the state of the art in the diagnosis and management of motility and functional disorders in children. Presentations were divided into esophageal, antral duodenal, and colorectal modules. Each module included oral presentations by experts in the respective fields, leading to thought-provoking discussions. There were 2 breakout sessions with small group discussions on select topics, focusing on defining scientific insights into the diagnosis and management of pediatric functional gastrointestinal and motility disorders in a systematic, segment-based approach. CONCLUSIONS The field of neurogastroenterology has made remarkable progress in the last decade. The current report summarizes the major learning points from the symposium highlighting the diagnosis and promising therapies on the horizon for pediatric neurogastrointestinal and motility disorders.
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Hypomorphic SI genetic variants are associated with childhood chronic loose stools. PLoS One 2020; 15:e0231891. [PMID: 32433684 PMCID: PMC7239456 DOI: 10.1371/journal.pone.0231891] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 04/02/2020] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE The SI gene encodes the sucrase-isomaltase enzyme, a disaccharidase expressed in the intestinal brush border. Hypomorphic SI variants cause recessive congenital sucrase-isomaltase deficiency (CSID) and related gastrointestinal (GI) symptoms. Among children presenting with chronic, idiopathic loose stools, we assessed the prevalence of CSID-associated SI variants relative to the general population and the relative GI symptom burden associated with SI genotype within the study population. METHODS A prospective study conducted at 18 centers enrolled 308 non-Hispanic white children ≤18 years old who were experiencing chronic, idiopathic, loose stools at least once per week for >4 weeks. Data on demographics, GI symptoms, and genotyping for 37 SI hypomorphic variants were collected. Race/ethnicity-matched SI data from the Exome Aggregation Consortium (ExAC) database was used as the general population reference. RESULTS Compared with the general population, the cumulative prevalence of hypomorphic SI variants was significantly higher in the study population (4.5% vs. 1.3%, P < .01; OR = 3.5 [95% CI: 6.1, 2.0]). Within the study population, children with a hypomorphic SI variant had a more severe GI symptom burden than those without, including: more frequent episodes of loose stools (P < .01), higher overall stool frequency (P < .01), looser stool form (P = .01) and increased flatulence (P = .02). CONCLUSION Non-Hispanic white children with chronic idiopathic loose stools have a higher prevalence of CSID-associated hypomorphic SI variants than the general population. The GI symptom burden was greater among the study subjects with a hypomorphic SI variant than those without hypomorphic SI variants.
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Demonstrating the benefits of a multidisciplinary aerodigestive program. Laryngoscope 2019; 130:521-525. [DOI: 10.1002/lary.27939] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 02/01/2019] [Accepted: 02/27/2019] [Indexed: 12/28/2022]
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Bowel preparation for pediatric colonoscopy: report of the NASPGHAN endoscopy and procedures committee. J Pediatr Gastroenterol Nutr 2014; 59:409-16. [PMID: 24897169 DOI: 10.1097/mpg.0000000000000447] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Pediatric bowel preparation protocols used before colonoscopy vary greatly, with no identified standard practice. The present clinical report reviews the evidence for several bowel preparations in children and reports on their use among North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition members. Publications in the pediatric literature for bowel preparation regimens are described, including mechanisms of action, efficacy and ease of use, and pediatric studies. A survey distributed to pediatric gastroenterology programs across the country reviews present national practice, and cleanout recommendations are provided. Finally, further areas for research are identified.
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Allergens on desktop surfaces in preschools and elementary schools of urban children with asthma. Allergy 2014; 69:960-963. [PMID: 24750034 DOI: 10.1111/all.12384] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2014] [Indexed: 11/27/2022]
Abstract
Desktop dust has been studied as a source of food allergen, but not as a source of potential aeroallergen exposure. Thirty-six wiped samples from desktop surfaces were collected from preschools and schools. Samples were analyzed for detectable levels of common aeroallergens including Alternaria, cockroach, dog, dust mite, cat, mouse, and rat allergens by immunoassay. Mouse allergen was the most prevalent, detectable in 97.2% of samples. Cat allergen was detectable in 80.6% of samples, and dog allergen was detectable in 77.8% of samples. Other allergens were not as prevalent. Mouse was the only allergen that was highly correlated with settled floor dust collected from the same rooms (r = 0.721, P < 0.001). This is the first study to detect aeroallergens on desktop surfaces by using moist wipes. Allergens for mouse, cat, and dog were highly detectable in wipes with mouse desktop surface levels correlating with levels in vacuumed floor dust.
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Diagnosis of autoimmune pancreatitis vs neoplasms in children with pancreatic mass and biliary obstruction. Clin Gastroenterol Hepatol 2012; 10:1051-5.e1. [PMID: 22732272 DOI: 10.1016/j.cgh.2012.06.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 02/07/2023]
Abstract
Autoimmune pancreatitis (AIP) is a rare autoimmune disorder that resembles pancreatic neoplasia and occurs primarily in adults. Management strategies and diagnostic criteria are being revised for adult patients; there are no clear diagnostic criteria for pediatric patients. We describe 3 cases of AIP in children, on the basis of clinical and pathology records. We also performed a literature review to determine the incidence of biliary obstruction in pediatric patients with pancreatic tumors. We found that children with AIP present with a variety of symptoms, and that diagnostic and therapeutic strategies also vary. Furthermore, on the basis of the many studies published on pediatric patients with pancreatic tumors, only a small percentage of the patients have biliary obstructions. Cytologic analysis of samples collected by fine-needle aspiration cytology does not accurately identify AIP in children. However, frozen section needle core biopsy samples can be used to distinguish children with AIP from those with neoplasia. Children with pancreatic mass and biliary obstruction are more likely to have AIP than neoplasms.
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Food Allergy and Increased Asthma Morbidity in a School Inner-city Asthma Study. J Allergy Clin Immunol 2012. [DOI: 10.1016/j.jaci.2011.12.441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Association of ACT and Childhood ACT Scores With FEV1 in Primary and Specialty Clinics using the Asthma Control Tracker ™ Web-Based Registry. J Allergy Clin Immunol 2009. [DOI: 10.1016/j.jaci.2008.12.153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Human interferon-gamma (IFN-gamma) purified to electrophoretic homogeneity by a cation exchange h.p.l.c., was used for the development of monoclonal antibodies. Following immunization, spleen lymphocytes of two mice showing the highest binding and neutralizing titers were isolated, fused with NSO mouse myeloma cells and cloned. The screening of hybridomas was based on precipitation of the immune complexes with a second antibody and recovery of the biological activity of IFN-gamma from the precipitate. Twenty nine independent hybridomas secreting antibodies specific to IFN-gamma were obtained. Twelve out of these 29 hybridomas produced antibodies that neutralized the antiviral activity of pure as well as crude IFN-gamma. Moreover, IFN-gamma obtained by various induction procedures was neutralized as well, indicating that these various IFN-gamma subtypes are immunologically cross-reactive. Immune precipitation of partially purified 125I-labelled IFN-gamma by several monoclonal antibodies revealed two protein bands of 26,000 and 21,000 daltons. Immunoaffinity chromatography of IFN-gamma gave a 50-fold purification to a specific activity > or = 4 x 10(7) units/mg. Two of the monoclonal antibodies were found suitable for a sensitive and rapid double antibody solid-phase radioimmunoassay, allowing the detection of IFN-gamma at concentrations of at least 4 ng/ml (150 units/ml) within 8 h.
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Abstract
BACKGROUND Preclinical studies suggest that glutamate antagonists help ameliorate motor fluctuations in patients with PD treated with levodopa. METHODS In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study, the authors assessed the safety, tolerability, and efficacy of the glutamate receptor blocker remacemide hydrochloride in 279 patients with motor fluctuations treated with levodopa. The primary objective was to assess the short-term tolerability and safety of four dosage levels of remacemide during 7 weeks of treatment. Patients were also monitored with home diaries and the Unified PD Rating Scale (UPDRS) to collect preliminary data on treatment efficacy. RESULTS Remacemide was well tolerated up to a dosage of 300 mg/d on a twice daily schedule and 600 mg/d on a four times daily schedule. The most common dosage-related adverse events were dizziness and nausea, as observed in previous studies of remacemide. The percent "on" time and motor UPDRS scores showed trends toward improvement in the patients treated with 150 and 300 mg/d remacemide compared with placebo-treated patients, although these improvements were not significant. CONCLUSION Remacemide is a safe and tolerable adjunct to dopaminergic therapy for patients with PD and motor fluctuations. Although this study had limited power to detect therapeutic effects, the observed improvement is consistent with studies of non-human primates with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian signs and symptoms. Additional studies are warranted to confirm these results over an extended period of observation, and to explore the potential neuroprotective effects of remacemide in slowing the progression of PD.
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Abstract
Chediak-Higashi syndrome (CHS) is a rare autosomal-recessive disorder characterized by immune deficiency, partial oculocutaneous albinism, and large eosinophilic, peroxidase-positive inclusion bodies in granule-containing cells. The adult form of CHS manifests during late childhood to early adulthood and is marked by various neurologic sequelae, including parkinsonism, dementia, spinocerebellar degeneration, and peripheral neuropathy. We report the case of a 29-year-old man with adult CHS who exhibited a progressive asymmetric parkinsonism, including rest tremor, and axial, cervical, and appendicular dystonia. The diagnosis was confirmed by the presence of characteristic large peroxidase-positive granules within leukocytes and markedly decreased natural killer cell function. Levodopa/carbidopa and amantadine provided benefit for tremor. CHS, although rare, should be considered in the differential diagnosis of young adult parkinsonism.
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A home diary to assess functional status in patients with Parkinson's disease with motor fluctuations and dyskinesia. Clin Neuropharmacol 2000; 23:75-81. [PMID: 10803796 DOI: 10.1097/00002826-200003000-00003] [Citation(s) in RCA: 197] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In clinical trials for patients with Parkinson's disease (PD) with motor fluctuations, efficacy is generally ascribed to an intervention if motor function is significantly improved or if "off" time is significantly reduced. However, we have argued that patients might not be improved if off time is reduced only to the extent that unwanted dyskinesia is increased. Therefore, a home diary should include an assessment of dyskinesia to provide an accurate reflection of clinical status over a period of time. We undertook two studies to develop a home diary to assess functional status in patients with PD with motor fluctuations and dyskinesia. In both studies, patients concurrently completed a test and a reference diary. In Study I, we evaluated the impact of different severities of dyskinesia on patient-defined functional status. There were 1,149 evaluable half-hour time periods from 24 patients; 94.3% of off time was considered "bad" time and 90.2% of "on" time without dyskinesia, 72.6% of on time with mild dyskinesia, 43.0% of on time with moderate dyskinesia, and 15.2% of on time with severe dyskinesia was considered "good" time. In Study II, we evaluated a new home diary designed to separate dyskinesia that had a negative impact on patient-defined functional status from dyskinesia that did not. There were 816 evaluable time periods from 17 patients; 84.9% of off time and 89.9% of on time with troublesome dyskinesia was considered bad time while 85.5% of on time without dyskinesia and 93.8% of on time with nontroublesome dyskinesia was considered good time. With this diary (Diary II), the effect of an intervention can be expressed as the change in off time and the change in on time with troublesome dyskinesia (bad time). The sum can be used as an outcome variable and compared to baseline or across groups. In evaluating the efficacy of an intervention, assessment of change in off time and change in on time with troublesome dyskinesia provides a more accurate reflection of clinical response than change in off time alone.
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Using a parity-sensitive sieve to count prime values of a polynomial. Proc Natl Acad Sci U S A 1997; 94:1054-8. [PMID: 11038598 PMCID: PMC19742 DOI: 10.1073/pnas.94.4.1054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It is expected that any irreducible polynomial with integer coefficients assumes infinitely many prime values provided that it satisfies some obvious local conditions. Moreover, it is expected that the frequency of these primes obeys a simple asymptotic law. This has however been proven for only a few special classes of polynomials. In the most famous unsolved cases the sequence of values is "thin" in the sense that it contains fewer than N(theta) integers up to N for some constant theta < 1. Quite generally it seems to be difficult to show the infinitude of primes in a given thin integer sequence and there is no polynomial for which this has hitherto been done. The polynomial x(2) + y(4) is an example of such a thin sequence; here, specifically, theta = 3/4. We report here the development of new methods that rigorously demonstrate the asymptotic formula in the case of this polynomial and that are applicable to an infinite class of polynomials to which this one belongs. The proof is based partly on a new sieve method that breaks the well-known parity problem of sieve theory and partly on a careful harmonic analysis of the special properties of biquadratic polynomial sequences.
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Loss of parathyroid hormone-stimulated 1,25-dihydroxyvitamin D3 production in aging does not involve protein kinase A or C pathways. J Bone Miner Res 1994; 9:339-45. [PMID: 8191927 DOI: 10.1002/jbmr.5650090308] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Intestinal calcium absorption declines with aging as a result of decreased renal 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] biosynthesis. At least part of the decline in 1,25-(OH)2D3 may be due to acquired resistance to parathyroid hormone (PTH) stimulation of renal 25-hydroxyvitamin D1-hydroxylase (1-OHase) activity. To test whether aging rats can increase 1,25-(OH)2D3 production in response to PTH, male rats of the same litter were fed a normal Ca diet and were sacrificed at 175-225 g (young rats) or 3 months later at 350-425 g (aging rats). At sacrifice, basal serum 1,25-(OH)2D3 levels (88 +/- 16 versus 49 +/- 8 pg/ml, P < 0.05) and in vitro renal proximal tubule 1-OHase activity (178 +/- 15 versus 77 +/- 5 pmol/mg protein/5 minutes, n = 6, P < 0.001) were lower in aging animals. rPTH-(1-34) (10(-11) or 10(-7) M) increased in vitro 1,25-(OH)2D3 secretion by perifused renal proximal tubules from young but not aging rats. For young and aging rats, rPTH-(1-34) (10(-7) M) increased proximal tubule cAMP-dependent protein kinase (PKA) activity, and lower concentrations (10(-11) M) stimulated translocation of protein kinase C (PKC) activity from cytosolic to soluble membrane proximal tubule cell fractions. The results of this study show that PTH activation of 1,25-(OH)2D3 production may involve both signaling pathways, with the PKC pathway responsive to lower concentrations of the hormone. The acquired resistance to PTH stimulation of 1,25-(OH)2D3 production in aging appears not to involve the hormonal activation of PKA or PKC.
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Isolation of two discrete human interferon-gamma (immune) subtypes by high-performance liquid chromatography. Anal Biochem 1984; 137:115-9. [PMID: 6203427 DOI: 10.1016/0003-2697(84)90355-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A rapid procedure for isolation of two biologically active human interferon-gamma subtypes was developed. Crude interferon-gamma produced in a serum-free culture of peripheral blood mononuclear cells by mitogen stimulation was concentrated and partially purified by chromatography on controlled-pore glass. Following desalting and concentration by ultrafiltration, a step of cation-exchange high-performance liquid chromatography was performed. A linear NaCl gradient (0.01-0.4 M) at pH 7 was employed and four peaks of biological activity eluting at 0.17, 0.20, 0.26 (major peak), and 0.3 M were obtained. The major peak of biological activity coincided with two protein peaks. Analysis of one fraction from the major activity peak by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a protein band having an apparent molecular weight of 26,000, while an adjacent fraction of the same activity peak contained a protein band corresponding to a molecular weight of 21,000. The specific activity of both subtypes was 7-10 X 10(6) units/mg.
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Abstract
Two experiments were conducted to examine further the role of the dopaminergic system in the ovulatory cycle of the hen. In experiment 1, dopamine (DA; 8 microgram) was injected intraventricularly 14 hr prior to the C1 ovulation (to determine the efficacy of DA in causing premature ovulation) and the DA-receptor blocker, pimozide, implanted intraventricularly for the previous 24 hr was used to assess the specificity of the response. The luteinizing hormone (LH) radioimmunoassays from serial blood samples subsequent to the injection, indicated no effect of the DA treatment on either the time or the magnitude of the preovulatory LH surge. In Experiment 2, an intraventricular injection of DA (10 microgram) was made 8 hr prior to the C1 ovulation (to examine the effect of DA on the normal preovulatory LH surgery) and assay results from blood samples at short intervals immediately after the injection showed no effect of the treatment on plasma LH levels. These results, in addition to the finding that the pimozide implant caused no disruption of the ovulatory cycle, suggest that the dopaminergic system is not essential to the ovulatory process in the hen.
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La diversité biologique humaine. Human Biological Diversity. POPULATION 1981. [DOI: 10.2307/1532338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
In a sruvey of 119 cystic fibrosis (CF) centres in the U.S.A. and Canada, information was obtained on 129 pregnancies in 100 patients with CF. 97 pregnancies were completed resulting in 86 viable infants, only one of whom had CF. This is close to the expected incidence and attests to the recessive nature of the transmission of CF, the commonest lethal genetic disorder of Caucasians. Shortened gestation and increased maternal and perinatal mortality were related to severe maternal pulmonary infection. Increased respiratory and cardiac work, and especially hypervolaemia, are hazards for pregnant women with CF, and when combined with advanced pulmonary disease may lead to increased perinatal complications. Maternal hypoxia and transplacental passage of antibiotics may affect the fetus; however, there were no congenital anomalies in this series in spite of frequent use of antibiotics by these mothers. Unless the clinical score is high, pregnancy should be avoided in CF patients.
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Abstract
An analysis was made of correlative factors which might be related to the angiographically measured extent of coronary artery disease in 140 patients. All patients presented with clinically important chest pain. Thirty-three had a normal coronary arteriogram. The extent of the atheromatous process was measured precisely at angiography by three different techniques. A coronary score, based on the percentage of luminal narrowing, was found to be best suited for the analysis. The most important contributory factors to the severity of atherosclerosis was duration of clinical history, number of previous myocardial infarctions, and male sex, but more specifically elevation of serum cholesterol and diabetes mellitus. Cigarette smoking, obesity, hypertension, a family history of atherosclerosis, and elevated serum triglycerides had a positive influence but this was not statistically significant.
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Environmental chemistry--an examination of available literature. JOURNAL OF CHEMICAL DOCUMENTATION 1973; 13:189-92. [PMID: 4585462 DOI: 10.1021/c160051a005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Plant design and econmics for chemical engineers, Max S. Peters, McGraw-Hill Back Company, Inc., New York(9158). 511 pages. 511.00. AIChE J 1959. [DOI: 10.1002/aic.690050403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Carriers of Tuberculosis. West J Med 1941. [DOI: 10.1136/bmj.2.4214.525-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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