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51.
52.
Elisabeth Arnauld John du Pont 《Pflügers Archiv : European journal of physiology》1982,394(3):195-201
A close relationship exists between drinking and the release of vasopressin, the two main factors responsible for the maintenance of body water content. Whereas the participation of peripheral factors, such as oropharyngeal stimulation, seems obvious in the metering of fluid intake and in thirst satiation, very little is known about their influence on vasopressin release. In the present experiments, the influence of drinking on vasopressin release was studied using both biochemical and electrophysiological approaches.In one group of monkeys made thirsty by water deprivation, the subsequent drinking of water during a 5–8 min induced: i) a short-term response, consisting of an abrupt fall in plasma vasopressin concentration which was independent of osmolality, occurred at the time of drinking and was partly reversed after the cessation of drinking, and ii) a longer lasting response, consisting of a slow diminution of plasma vasopressin concentration as the intestinal absorption of water progressed. In another group of thirsty monkeys, extracellular recordings were made during drinking from cells which were identified as neurosecretory neurones of the supraoptic nucleus, a number of them being considered vasopressin secreting on the basis of their phasic pattern of firing. Their firing decreased considerably during the periods of water intake and recovered to control levels immediately after-wards.The decrease in vasopressin release at the onset of water intake, the diminution in the firing rate of the neurones, the short latency and the reversibility of these events after cessation of drinking, suggest that a reflex inhibition of vasopressin-secreting neurones occurs which is probably induced by peripheral stimuli and most likely via oropharyngeal or other visceral receptors. It is postulated that this reflex inhibition of vasopressin release may participate in some active manner in the anticipatory mechanisms of thirst satiation. 相似文献
53.
John P. McCarthy Marcas M. Bamman Janice M. Yelle Adrian D. LeBlanc Roger M. Rowe Michael C. Greenisen Stuart M. C. Lee Elisabeth R. Spector Suzanne M. Fortney 《European journal of applied physiology》1997,76(1):32-40
Resistance exercise has been suggested to increase blood volume, increase the sensitivity of the carotid baroreceptor cardiac reflex response (BARO), and decrease leg compliance, all factors that are expected to improve orthostatic tolerance. To further test these hypotheses, cardiovascular responses to standing and to pre-syncopal limited lower body negative pressure (LBNP) were measured in two groups of sedentary men before and after a 12-week period of either exercise (n = 10) or no exercise (control, n = 9). Resistance exercise training consisted of nine isotonic exercises, four sets of each, 3 days per week, stressing all major muscle groups. After exercise training, leg muscle volumes increased (P?0.05) by 4–14%, lean body mass increased (P = 0.00) by 2.0 (0.5)?kg, leg compliance and BARO were not significantly altered, and the maximal LBNP tolerated without pre-syncope was not significantly different. Supine resting heart rate was reduced (P = 0.03) without attenuating the heart rate or blood pressure responses during the stand test or LBNP. Also, blood volume (125I and 51Cr) and red cell mass were increased (P?0.02) by 2.8% and 3.9%, respectively. These findings indicate that intense resistance exercise increases blood volume but does not consistently improve orthostatic tolerance. 相似文献
54.
Dennis McGinty Michael Littner Elisabeth Beahm Elizabeth Ruiz-Primo Earl Young James Sowers 《Neurobiology of aging》1983,3(4)
—The incidence of sleep-related breathing disorders (SRBDs) associated with hemoglobin desaturation was determined by nocturnal polygraphic evaluations in 26 healthy men, aged 55–70 years. Sixteen subjects (62%) had abnormal rates of at least 12 episodes per hour of sleep: 8 had occlusive, and 8 had central apnea or hypopnea. During waking ten of 16 SRBD subjects and only one subject without SRBDs exhibited either an elevated nasopharyngeal airway resistance (n=4) or a reduced ventilatory response to hypercapnia (n=4) and/or hypoxia (n=3). However, these abnormalities were not related to the type or severity of SRBDs, and 6 subjects with SRBDs demonstrated no respiratory defect. We conclude that SRBDs have a very high incidence in older males and are not usually secondary to pulmonary cardiac, neurological, or behavioral disorders. Additionally, we hypothesize that abnormalities in ventilatory control or upper airway resistance contribute to SRBDs, but depression of brain stem reticular formation activity during sleep plays a primary role in these disorders. Factors related to both aging and SRBDs are reviewed. These include reduced chemoreceptor responses, altered steroid hormone metabolism, and use and metabolism of hypnotic drugs and alcohol. 相似文献
55.
Elisabeth Puchhammer-Stckl Wolfgang Mor Michael Kundi Franz-Xaver Heinz Hanns Hofmann Christian Kunz 《Journal of medical virology》1994,43(2):143-147
Serum samples from 46 children with chronic and probably transfusion acquired hepatitis were tested for the presence of hepatitis C virus (HCV) RNA by a “nested” polymerase chain reaction (PCR) assay, to judge a possible risk of HCV transmission from these patients. In 73% of the samples, viral RNA was detected, indicating a high virus prevalence in this patient group. High titers of HCV-RNA were observed in some sera as shown by the detection of virus in some samples even at dilutions of 10?3. Comparison of simultaneously obtained PCR results and ALT values revealed no significant correlation between virus presence in serum and higher ALT levels. It was, however, shown that unusually high ALT values may reflect a high titer of viral RNA in serum. To investigate the prevalence of viral RNA in saliva, which could be a vehicle of virus transmission, 35 throat washing samples from the HCV-infected children were screened by PCR. Using three different sample preparation procedures, 20% of the throat washings were found to be positive for HCV-RNA. This indicates a prevalence of virus in this fluid lower than that reported previously. © 1994 Wiley-Liss, Inc. 相似文献
56.
Frank EL Schwarz EL Juenke J Annesley TM Roberts WL 《American journal of clinical pathology》2002,118(1):124-131
Carbamazepine, phenobarbital, phenytoin, and valproic acid are commonly used antiepileptic drugs that show complicated pharmacokinetic behavior Nonisotopic immunoassays are used routinely to monitor these drugs, and assay specificity is important to obtain accurate results. By using samples from subjects receiving each of these antiepileptic medications, competitive immunoassays for them were evaluated on an IMMULITE 2000 automated chemiluminescent analyzer (Diagnostic Products, Los Angeles, CA). Phenytoin assays were evaluated using an additional set of samples from patients with abnormal renal function. All 4 methods were linear, had imprecision of less than 10%, and compared well with other commercial immunoassays. A positive bias was observed for phenytoin measured in samples from uremic patients compared with a high-performance liquid chromatography reference method. The molar cross-reactivity of carbamazepine-10,11-epoxide was 12% in the carbamazepine assay. Phenytoin metabolites and fosphenytoin had substantial cross-reactivity in the phenytoin assay. All antiepileptic drug assays performed well and are suitable for use in monitoring patients receiving antiepileptic drug therapy. One possible exception is the phenytoin assay with samples from patients with renal insufficiency. 相似文献
57.
Vincent Thomas-de-Montpréville Rémi Nottin Elisabeth Dulmet Alain Serraf 《Cardiovascular pathology》2007,16(1):22-28
BACKGROUND: Heart tumors are rare lesions with variegated histological types. Their clinicopathological features could be more comprehensively categorized. METHODS: This is a 19-year retrospective study of 17 infants/toddlers (<2 years of age) and 42 patients aged between 14 and 79 years (mean = 51.5) in a surgical center. RESULTS: Congenital tumors (n = 17; 29%), including rhabdomyomas (n = 9), ventricular fibromas (n = 6), and hemangiomas (n = 1), required surgery mainly because of mass effect. Familial myofibromatosis was the only embolic congenital lesion. Acquired benign tumors (n = 28; 47%) included myxomas (n = 21), fibroelastomas (n = 3), myofibroblastic inflammatory tumors (n = 2), and lipomas (n = 2). Eight (29%) were revealed by systemic embolization. These benign noncongenital tumors were all treated by complete resection, except for an incompletely resected lipoma of the mitral valve. Postoperative arrhythmia (n = 1) and pericardial effusion (n = 3) were the only complications. Primary sarcomas (n = 8; 14%) were mostly vascular tumors (five of eight), and patients with high-grade tumors had a mean survival of 15 months (n = 5). Cardiac metastases (n = 6; 10%) were from carcinomas (n = 3) or sarcomas (n = 3); apart from a necrotic metastasis, all patients died (mean survival of 6 months). CONCLUSIONS: This study shows that, regardless of patients' age, heart tumors can be classified as: (a) congenital lesions, which are spontaneously nonprogressive or regressive lesions possibly requiring surgery mainly because of mass effect; (b) acquired benign tumors, which are lesions requiring surgery often because of embolization risk; and (c) primary and secondary malignant tumors, which are lesions with globally poor prognosis but with some indications for resection. 相似文献
58.
59.
Peter J Brasted Timothy J Bussey Elisabeth A Murray Steven P Wise 《Journal of neurophysiology》2002,87(1):631-633
Rhesus monkeys learned a series of conditional visuomotor associations involving two-dimensional "objects" that instructed one of three responses: tapping a touch screen, steady contact with the screen for a brief period, or steady contact for a longer period. Relative to controls, fornix-transected monkeys were impaired in the acquisition of new associations and in the retention of preoperatively learned ones. These findings challenge the view that the hippocampal system participates in associative learning only when spatial information is relevant to either the stimulus or the response. 相似文献
60.
Doris Škorić‐Milosavljević Fleur V. Y. Tjong Julien Barc Ad P. C. M. Backx Sally‐Ann B. Clur Karin van Spaendonck‐Zwarts Roelof‐Jan Oostra Najim Lahrouchi Leander Beekman Regina Bökenkamp Daniela Q. C. M. Barge‐Schaapveld Barbara J. Mulder Elisabeth M. Lodder Connie R. Bezzina Alex V. Postma 《American journal of medical genetics. Part A》2019,179(9):1836-1845
The first human mutations in GATA6 were described in a cohort of patients with persistent truncus arteriosus, and the phenotypic spectrum has expanded since then. This study underscores the broad phenotypic spectrum by presenting two patients with de novo GATA6 mutations, both exhibiting complex cardiac defects, pancreatic, and other abnormalities. Furthermore, we provided a detailed overview of all published human genetic variation in/near GATA6 published to date and the associated phenotypes (n = 78). We conclude that the most common phenotypes associated with a mutation in GATA6 were structural cardiac and pancreatic abnormalities, with a penetrance of 87 and 60%, respectively. Other common malformations were gallbladder agenesis, congenital diaphragmatic hernia, and neurocognitive abnormalities, mostly developmental delay. Fifty‐eight percent of the mutations were de novo, and these patients more often had an anomaly of intracardiac connections, an anomaly of the great arteries, and hypothyroidism, compared with those with inherited mutations. Functional studies mostly support loss‐of‐function as the pathophysiological mechanism. In conclusion, GATA6 mutations give a wide range of phenotypic defects, most frequently malformations of the heart and pancreas. This highlights the importance of detailed clinical evaluation of identified carriers to evaluate their full phenotypic spectrum. 相似文献