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An array of bidirectionally coupled relaxation oscillators is proposed as a model of gastric electric-control activity. The characteristics of relaxation oscillators simulating control activity, such as intact and intrinsic frequency gradients and phase-lag patterns, were studied in anesthetized dogs. A marked intrinsic frequency gradient was found along the axis of the stomach, and a slight intrinsic frequency gradient around the circumference. The phase lag/cm decreased distally from the body of the stomach to the antrum. The model showed all these characteristics. Each oscillator in the array was represented by a system of two first-order nonlinear differential equations. The model was programmed on analog and hybrid computers.Supported by the Medical Research Council of Canada, the Alberta Heart Foundation and the National Research Council of Canada.  相似文献   
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Immunohistochemical studies of pancreatic tissue from patients with cystic fibrosis associated with diabetes mellitus (CFDM) show increased numbers of somatostatin secreting delta cells. To look for a possible functional correlate to this finding basal and arginine stimulated plasma somatostatin and serum C peptide concentrations in eight insulin treated patients with cystic fibrosis and eight normal male controls were measured. Mean basal somatostatin concentrations were not different in the two groups. Mean peak somatostatin concentrations were significantly higher in the group with CFDM: 11.60 pmol/l v 7.14 pmol/l in controls. Mean peak C peptide concentrations were significantly lower in the group with cystic fibrosis: 0.89 nmol/l v 4.27 nmol/l in controls. This observation provides a physiological correlate to the pathological finding of increased somatostatin content in pancreatic tissue from patients with CFDM. Selective preservation of somatostatin secretion in patients with cystic fibrosis may further complicate pancreatic endocrine insufficiencies through paracrine inhibition of insulin and glucagon secretion.  相似文献   
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Seminal megavesicles with adult polycystic kidney disease   总被引:2,自引:0,他引:2  
Adult polycystic kidney disease has been found in association with pathological dilatation of the seminal vesicles in six patients. These men appeared normal on clinical examination, but had azoospermia or severe oligozoospermia. They were investigated by scrotal exploration with vasography, renal and transrectal ultrasound scans (TRUS), and percutaneous puncture of the seminal vesicles in one case, before and after resection of the ejaculatory ducts. This revealed that the gross dilatation of the seminal vesicles was not caused by obstruction, but appeared to be due to atonicity (megavesicles). These ultrasonic appearances, when described previously, were incorrectly thought to be due to seminal vesicle cysts.   相似文献   
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Background  

As part of the NHLBI Family Blood Pressure Program, the Genetic Epidemiology Network of Arteriopathy (GENOA) recruited 575 sibships (n = 1583 individuals) from Rochester, MN who had at least two hypertensive siblings diagnosed before age 60. Linkage analysis identified a region on chromosome 2 that was investigated using 70 single nucleotide polymorphisms (SNPs) typed in 7 positional candidate genes, including adducin 2 (ADD2).  相似文献   
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The traceability of blood products is an essential part of haemovigilance and transfusion safety. A pilot survey assessed the actual traceability by analysing transfusion information collected from medical records of a representative sample of 390 labile blood products transfused in a French university hospital.Transfusion and distribution forms were missing in 2.3% and 6.9% respectively. Availability and validity of transfusion information varied according to the nature of the expected information, elements of patients' records and types of wards. The location where the transfusion was performed was false or ambiguous in 38% of cases in surgery. Crude traceability, evaluated by the feedback of validated distribution forms, was estimated at 85.2% whereas actual traceability was estimated at 81.9% (SD 1.7%). High availability (98.7%) of at least one of the two sheets of the distribution form in medical records, or in the blood bank, revealed that a significant improvement of traceability should come from a better compliance to the rules of information transmission. The actual traceability differed significantly according to clinical services (worse in surgery) and was lower in case of autologous or absence of previous transfusion.An analysis of markers of good traceability should suggest efficient evolution of organization and information systems. This pilot study shows the relevance and feasibility of this kind of survey which could interestingly be performed on a large national representative random sample. © 1998 Elsevier, Paris  相似文献   
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