The effect of acute metabolic or respiratory acid-base disturbances on biliary bicarbonate secretion was examined in bile fistula rats. Animals were infused with ursodeoxycholate at a rate that stimulates bicarbonate secretion (1 mumole . min-1 X 100 gm-1), in control conditions and during acute acid-base disturbances. Metabolic acidosis or alkalosis were induced by HCl or NaHCO3 infusions, and respiratory acidosis or alkalosis were created respectively by adding CO2 to the inspired gas or by hyperventilation in artificially ventilated animals. Biliary bicarbonate concentration was always higher than plasma bicarbonate concentration. During metabolic disturbances, changing the plasma bicarbonate concentration from 9.2 to 30.2 mM stimulated biliary bicarbonate secretion by 113%. During respiratory disturbances, changing the plasma PCO2 from 25.5 to 59.8 mm Hg also increased biliary bicarbonate secretion by 89%. Biliary bicarbonate output was thus independent of plasma pH. When all animals were considered, bile flow was positively correlated with biliary bicarbonate concentration (r = 0.71, p less than 0.001). Acetazolamide significantly decreased ursodeoxycholate-induced bile flow and bicarbonate secretion by 20 and 22%, respectively. These results support the hypothesis that there is a relationship between ursodeoxycholate-induced bicarbonate secretion and bile flow. They are also consistent with the view that ursodeoxycholate-stimulated biliary bicarbonate secretion in the rat is strongly affected by plasma bicarbonate and PCO2, but not by plasma pH, and involves carbonic anhydrase.

Acetazolamide↗

PubMedDate not supplied

Effect of colchicine and phalloidin on the distribution of three plasma membrane antigens in rat hepatocytes: comparison with bile duct ligation.

The hepatocyte plasma membrane presents a morphological and functional regionalization into three domains: the sinusoidal; the lateral, and the canalicular. The mechanisms responsible for the biogenesis and maintenance of this regionalization are poorly understood. In this work, we have used colchicine and phalloidin, two drugs known to interfere with the secretory processes in hepatocytes, to study whether they also affect the transport of membrane proteins. The localization of three plasma membrane antigens was studied by light and electron microscopy using monoclonal antibodies identifying either the sinusoidal (A39) or the lateral (B1) or the canalicular (B10) domains in normal hepatocytes. In rats injected with colchicine (0.25 mg per 100 gm), A39 moved from the sinusoidal membrane to the lateral and canalicular ones, whereas B10 was displaced from the canalicular to the sinusoidal and lateral membranes, resulting after 8 hr in an almost equal labeling of the three domains with both antibodies. In rats injected daily for 7 days with phalloidin (50 micrograms per 100 gm), A 39 became mainly localized on the bile canalicular membrane instead of the sinusoidal one; B10 predominated on the canalicular membrane as in controls but in places it labeled the sinusoidal and lateral domains as well. In bile duct-ligated rats studied for comparison for 4, 10 or 21 days, A39 and B10 localizations evolved as after phalloidin, but the changes were more marked. B1 was not affected by any of the treatments. In conclusion, colchicine, phalloidin and bile duct ligation do not seem to hinder the antigens in reaching the plasma membrane, but induce a redistribution of two of them, suggesting a disturbance in the biogenesis and/or control of the plasma membrane regionalization. Such an abnormal distribution could be involved in--or contribute to--the initiation of cholestasis.

Animals↗

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Reproducibility of electroretinograms recorded with DTL electrodes.

The purpose of this study was to examine whether the use of the DTL fiber electrode yields stable and reproducible electroretinographic recordings. To do so, luminance response function, derived from dark-adapted electroretinograms, was obtained from both eyes of 10 normal subjects at two recording sessions spaced by 7-14 days. The data thus generated was used to calculate Naka-Rushton Vmax and k parameters and values obtained at the two recording sessions were compared. Our results showed that there was no significant difference in the values of Vmax and k calculated from the data generated at the two recording sessions. The above clearly demonstrate that the use of the DTL fiber electrode does not jeopardize, in any way, the stability and reproducibility of ERG responses.

Adaptation, Ocular↗

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Structural identification, subcellular localization and secretion of bovine adrenomedullary neuromedin C [GRP-(18-27)].

Bombesin-like immunoreactivity (BLI) was purified from acid (HCl) extracts of bovine adrenal medulla. High performance liquid chromatography (HPLC) on a mu-Bondapak C18 column revealed the presence of five molecular forms of BLI, one coeluting with synthetic gastrin releasing peptide (GRP), the mammalian counterpart of amphibian bombesin, one coeluting with neuromedin C, one coeluting with neuromedin B and the two other ones coeluting with the oxidized forms of neuromedins B and C. The material corresponding to neuromedin C was purified to homogeneity and its amino acid composition and sequence corresponded to those expected for neuromedin C. HPLC analysis on an analytical SP-5PW column of subcellular extracts of bovine adrenal medulla indicated that neuromedin C is almost exclusively localized in secretory granules. The neuropeptide function of neuromedin C and/or other BLI peptides at this level was supported by the stimulatory effect of carbamylcholine (500 microM) on the release of BLI (4.5-fold increase over the basal release of 19 fmol/5 min) from perfused bovine adrenal glands.

Adrenal Medulla↗

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Renal replacement in end-stage renal disease patients over 75 years old.

BACKGROUND: Over the last decade, the age of dialysis patients has been increasing steadily in several units in Canada. Our main objective was to assess prevalence, co-morbidity and outcome of ESRD patients over 75 years old at the beginning of dialysis treatment in our center. As a group, they were compared to younger dialysis patients treated simultaneously. METHODS: In the last 5 years, all cases beginning dialysis in our institution who were above 75 years of age were reviewed, as well as cases aged between 50 and 60 years who started dialysis during the same period. Between January 1996 and December 2000, among a total of 429 new chronic dialysis patients, 67 ESRD patients over 75 years (15.6%) and 66 patients between 50 and 60 years (15.4%) began dialysis treatment. RESULTS--PRIMARY AND SECONDARY: Diabetes was present in 37% of elderly and in 56% of the younger patients. Younger patients had been referred earlier to our nephrologists than the older ones (42 vs. 27%). Elderly were more frequently treated by hemodialysis than peritoneal dialysis (81 vs. 19%) when compared to their younger counterparts (65 vs. 35%). Long-term catheters for hemodialysis were used more often in elderly patients. No renal transplantation were performed in older patients while 7 younger patients received a renal graft. Survival rates after 1 and 3 years were, respectively, 93 and 74% for patients between 50 and 60 years, whereas it decreased to 80 and 45% for those over 75 years (p = 0.002). More than 50% of patients older than 75 years died within 2 years after starting dialysis; their mean survival was 31 months; patients starting dialysis between 50 and 60 years survived on the average 44 months during the study period. According to the multivariate logistic regression model, risk factors for increased mortality in the older group were: number of hospitalization days during the past 3 months (OR 34.8, 95% CI 8.3-145.7, p < 0.001) and lower weight (OR 16.6, 95% CI 2.0-139.0, p = 0.001). CONCLUSION: We may conclude that, in our hands, life expectancy of patients who began dialysis above 75 years is significantly shorter than for patients for whom dialysis is initiated between age 50 and 60 years, especially if they have a low weight, lose weight and/or require hospitalization.

Age Factors↗

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[Lithium and pregnancy (author's transl)].

The problem has been considered of the action of Lithium salts on the progress of pregnancy and on the product of the conception. Lithium can bring about serious troubles in morphogenesis in invertebrate animals. The results obtained in mammals in laboratory experiments differ from species to species but it seems that these animals can be given about 8 to 9 times the levels of Lithium that are used in man without causing teratogenic effects. A statistical review of the children born to human mothers taking Lithium in pregnancy shows up an increase in the incidence of cardio-vascular abnormalities. (7.8% instead of 0.04%). The infants that have received Lithium and have not been anatomically affected show no more developmental problems later than others.

Abnormalities, Drug-Induced↗

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Recovery of intellectual function after a brain injury: a comparison of longitudinal and cross-sectional approaches.

The goal of this study was to investigate recovery of intellectual function as a function of age at the time of a brain lesion. Participants with unilateral cortical lesions were selected from an initial data base of 685 patients. Ninety-six participants formed a longitudinal cohort for a first study and 314 participants formed a cross-sectional cohort for a second study. Participants of each study were split into two age groups according to the age at the time of the lesion: (1) before 7 years, (2) 7 years or more. Results showed a significantly different recovery profile as a function of age in the longitudinal study. Older participants manifested recovery on VIQ and PIQ, while younger participants presented stable profiles. The longitudinal and cross-sectional studies revealed differing recovery profiles as a function of age. Results are discussed in the context of the Kennard principle and with regard to the methodological approaches.

Brain Injuries↗

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Diurnal time courses in psychomotor performance and waking EEG frequencies.

The present study examined the similarities between the diurnal time courses in the waking EEG activity and the psychomotor performance. The aim was to verify if some ongoing changes in the excitability of the cortical nerve cells across the daytime could facilitate the sensorimotor processing. EEG recordings and performance results for the Four Choice Reaction Time Test (FCRTT) were obtained every two hours, from morning to late evening period, in 8 young normal subjects (21.3 +/- 0.5 years). ANOVAs were used to verify the presence of diurnal variations in the two measures. Nonparametric correlations were obtained to test the similarity between the changes across the day in the two measures. Three EEG frequency bands (delta, sigma, and beta1) and the reaction time measures varied across the daytime. The changes in the sigma (12.00-13.75 Hz) and the beta1 (14.00-19.75 Hz) bands were similar to the diurnal variations in the reaction time measures. It is suggested that the changes in the sigma and the beta1 bands may facilitate the processing of the sensorimotor treatment.

Adult↗

PubMedDate not supplied

Genetic cholestatic liver diseases: the example of progressive familial intrahepatic cholestasis and related disorders.

Explore the source record for details and available documents.

Child↗

PubMedDate not supplied

[Influenza and pregnancy].

Benign flu should be differentiated from malignant flu often complicated with pulmonary diseases, which resulted, during the severe epidemics of 1918 and 1957, in a marked mortality in pregnant women, mortality which markedly decreased with the use of modern antibiotics and assisted ventilation. The effect on the fetus and the newborn is real, since abortions, premature deliveries, intrauterine growth delays, are not unusual in severe forms of flu, which could, for some authors, induce the occurrence of fetal malformations; but this is not quite confirmed. Therefore, passage of the virus from the mother to the fetus seems real. But the subsequent occurrence of neoplasia, especially leukemia, reported in some studies, appears costly. Anti-flu vaccination is recommended in pregnant women, especially those with chronic pulmonary diseases, or in case of epidemics.

Female↗