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Biomedical subjects

A M Weber

Publications and source records attributed to A M Weber.

At least 55 records · Page 3Linked to original sources
PubMed1992

Serous carcinoma of the peritoneum after oophorectomy.

BACKGROUND: Prophylactic oophorectomy in premenopausal women has been recommended to prevent ovarian cancer. However, serous carcinoma of the peritoneum, which is indistinguishable from ovarian carcinoma, can occur after oophorectomy. CASES: Two cases are reported of serous carcinoma of the peritoneum after oophorectomy. Presentation, management, and outcome are similar to those for ovarian carcinoma. CONCLUSION: More data are needed to quantify the risk of carcinoma after oophorectomy. Such knowledge may change the risk-benefit calculations of recommending prophylactic oophorectomy to premenopausal women at a certain age, and must be discussed with the patient who is considering prophylactic oophorectomy with or without other planned surgery.

Carcinoma, Papillary↗
PubMed1992

Fetal pleural effusion: a review and meta-analysis for prognostic indicators.

We reviewed the literature on fetal pleural effusion to identify prognostic indicators related to outcome. Data on 124 cases from 38 reports were collected and analyzed using chi 2 statistical analysis and stepwise multiple logistic regression. Termination of pregnancy occurred in ten cases, spontaneous resolution occurred in 11 cases with 100% survival, and overall mortality was 46%. Gestational age at delivery of greater than 31 weeks, the absence of hydrops, and the use of antenatal therapy (thoracentesis or shunt placement) were associated with good outcome. Gender of the fetus, hydramnios, extent of effusion as unilateral or bilateral, and mode of delivery were not significantly related to outcome. Recommendations for evaluation include search for other abnormalities and possible causes related to hydrops. Management is guided by gestational age and the presence of hydrops. Antenatal therapy is recommended if hydrops develops, particularly at a gestational age of less than 32 weeks.

Fetal Diseases↗
PubMed1991

Familial biliary atresia in three siblings including twins.

We report a North American Indian family of five children in which dizygotic twin sisters and a third sibling had biliary atresia. This is in contrast to many reports of discordant biliary atresia in twins. Added to 29 previously documented cases of familial biliary atresia, these three cases support the theory that both genetic and acquired factors play a role in the pathogenesis of this disease.

Biliary Atresia↗
PubMed1991

Laparoscopic cholecystectomy during pregnancy.

Cholelithiasis and cholecystitis frequently necessitate cholecystectomy. Laparoscopic cholecystectomy, by avoiding a laparotomy incision, greatly reduces recovery time and thus may reduce postoperative complications. We describe the first reported case of laparoscopic cholecystectomy during pregnancy. This technique should be considered as an alternative to laparotomy in selected patients.

Adult↗
PubMed1990

Effects of bile acids on actin polymerization in vitro.

Bile acids are major determinants of canalicular bile secretion, and there are indications that choleretic bile acids increase bile canalicular contractions, in isolated rat hepatocytes. Therefore, we examined the influence of various bile acids on the rate of actin polymerization in vitro. The free forms of cholic acid, ursodeoxycholic acid, and chenodeoxycholic acid, as well as their taurine and glycine conjugates, were incubated with purified muscle actin, at a concentration of 100-300 nmoles/mg actin. The rate of actin polymerization was measured by viscometry and the fluorescence of the pyrene probe, linked to actin. Results showed that all bile acids slow the rate of polymerization, and that the effect was dose-dependent. However, the reduction by chenodeoxycholic acid was greater than that caused by the other bile acids. The results indicate that bile acids, particularly in high concentrations interact with actin, a finding that may be related to the increased bile canalicular contractility, and altered canalicular membrane morphology, induced by choleretic bile acids.

Actins↗
PubMed1990

Influence of dehydrocholic acid on the secretion of bile acids and biliary lipids in rats.

This study investigated the influence of dehydrocholic acid (DHCA) infusion on the secretion of endogenous bile acids, and biliary lipids in rats in an attempt to explain the reduction of biliary lipid secretion associated with DHCA infusion. DHCA increased bile flow and the bile acids produced during the infusion were composed of three hydroxy-oxo metabolites (83-93%), and cholic acid (6-14%). Very little DHCA was secreted unchanged (less than 2%). The secretions of all the endogenous biliary bile acids were diminished within 30-60 min of infusion. DHCA furthermore reduced the secretion of exogenous cholic acid when co-infused with DHCA. Phospholipid secretion declined to an undetectable amount and cholesterol declined to 10% of the base value by the end of the infusion. The reduction of biliary lipid secretion during DHCA infusion was attributed to the diminished secretion of endogenous bile acids. These data show that DHCA infusion induces choleresis associated with reduced secretion of endogenous and/or exogenous biliary components.

Animals↗
PubMed1990

Development of bile secretory function in the neonatal guinea pig.

Maturation of hepatic bile formation and lipid secretion were examined in neonatal guinea pigs in an attempt to explain the earlier observation that the neonate (15 days old) is less susceptible to lithocholate-induced cholestasis than the adult. Bile flow and bile acid secretion were lowest at 12 h postpartum and increased to attain a maximum at 15 days. Thereafter, values decreased to a level which was not significantly different from that at 3 days of age. Bile acid analysis indicated the presence of chenodeoxycholic acid, 7-ketolithocholic acid and ursodeoxycholic acid in bile at all ages. But, at 15 days ursodeoxycholic acid was a major contributor to total bile acid secretion. Phospholipid and cholesterol secretion increased between the 1st and the 3rd day of age but decreased markedly at 15 days. This indicated an uncoupling of biliary lipid secretion and endogenous bile acids which was related in part to the nature of the bile acids secreted. Serum bile acid levels were markedly increased at 15 days of age. This hypercholanemia may reflect a rapid expansion of the bile acid pool including an enhanced bile acid secretion which could explain in part the resistance to the lithocholate cholestasis by increasing the secretory capacity for the toxic bile acid.

Aging↗
PubMed1989

High incidence of upper gastrointestinal tract involvement in children with Crohn disease.

This retrospective study of Crohn disease in 230 children and adolescents with a mean age of 12.5 years at the time of diagnosis and an average follow-up of 6.6 years showed that 30% had lesions of the esophagus, stomach, and duodenum. Three patients had Crohn disease isolated to the upper gastrointestinal tract. The 169 patients with both small and large bowel disease were at greater risk (33%, P less than .05) of having upper gastrointestinal lesions than the 37 with isolated small bowel disease and the 21 with disease limited to the colon and/or rectum. An aggregate of symptoms and signs more likely present in those with upper gastrointestinal involvement included: dysphagia, pain when eating, nausea and/or vomiting, and aphthous lesions of the mouth. Furthermore, weight loss was more severe and hypoalbuminemia more frequent. Because upper gastrointestinal series x-ray studies failed to detect upper gastrointestinal lesions in 13 patients of 69 of those with upper gastrointestinal disease, endoscopy should be considered in all children and adolescents in whom a diagnosis of Crohn disease is entertained. Endoscopy and biopsy of the upper gastrointestinal tract should be done in any patient with symptoms suggestive of proximal involvement. Finally, in view of the fact that endoscopy established the diagnosis of Crohn disease in five patients previously thought to have chronic ulcerative colitis, the procedure should routinely be performed in all patients with chronic ulcerative colitis or indeterminate colitis before surgery is performed.

Adolescent↗
PubMed1988

Cholesterol synthesis in the pathogenesis of lithocholic acid-induced cholestasis.

Lithocholic acid (LCA)-induced intrahepatic cholestasis is associated with increased de novo synthesis of hepatic cholesterol and augmented cholesterol content of the liver cell plasma membrane fraction enriched in bile canalicular complexes (BCM). To determine whether inhibition of cholesterol synthesis could prevent LCA-induced cholestasis, adult male Wistar rats were treated daily with the hypocholesterolemic agents, clofibrate (250 mg/kg) or mevinolin (25 mg/kg), for one, two or four days. After bile duct cannulation and bile collection for one hr, the animals were injected intravenously with 120 mumoles/kg of LCA or its carrier (albumin). Cholesterol synthesis was measured in liver homogenates, and its contribution to the BCM was estimated. LCA reduced bile flow by 51%, 35% and 25% after clofibrate pretreatment for one, two and four days, respectively, and by 51%, 30% and 42% in mevinolin-pretreated animals after one, two and four days. In control animals, cholesterol synthesis and the contribution of newly synthesized cholesterol in the BCM were increased after LCA injection. However, despite that cholesterol synthesis and the contribution of newly synthesized cholesterol in the BCM were reduced in drug-pretreated rats, LCA injection caused a relative increase in these parameters of a magnitude similar to that observed in controls. Thus, the ability of LCA injection to augment de novo cholesterol synthesis and its transport to the BCM may be an important pathogenetic step in the development of cholestasis.

Animals↗
PubMed1988

Chronic intermittent elemental diet improves growth failure in children with Crohn's disease.

Growth failure often complicates Crohn's disease in pediatric patients and is principally due to inadequate caloric intake. To assess whether intermittent courses of an elemental diet could reestablish growth, 8 children (aged 9.8-14.2 yr) with Crohn's disease and growth failure entered into a prospective trial. Each patient was studied during an observation year on standard therapy, then for an experimental year during which they received enteral elemental diet 1 out of 4 mo. An age- and disease-matched control group of 4 patients was treated by conventional medical therapy during both years. Elemental diet therapy was administered nocturnally, at home, by continuous nasogastric infusion and increased the daily caloric intake by 25% (p less than 0.01). Anthropometric measurements demonstrated significant height and weight gains in the elemental diet group vs. controls (p less than 0.01). Crohn's disease activity index and prednisone intake decreased significantly in patients receiving elemental diet therapy when compared with themselves and with controls on conventional medical therapy (p less than 0.05). In contrast, the rate of pubertal development was similar in both groups irrespective of the treatment modality. This study demonstrates that chronic intermittent elemental diet effectively reverses growth arrest, while decreasing prednisone requirements and Crohn's disease activity index in pediatric Crohn's disease patients prior to puberty.

Adolescent↗
PubMed1988

Digestive and absorptive phase anomalies associated with the exocrine pancreatic insufficiency of cystic fibrosis.

The pancreas has an enormous reserve capacity, and significant malabsorption usually signals complete absence of exocrine function. However, there is evidence that acid lipases of nonpancreatic origin play an important compensatory role. Complete duodenal hydrolysis of fat requires a series of complex interdependent physicochemical events involving pancreatic lipase, colipase, phospholipase A2, and bile salts in an environment where the pH must be close to neutrality. Lipolytic products must then be shuttled through the unstirred water layer to the surface of the microvillus membrane by ionized bile salts, which must be present in sufficient concentrations to form micelles. In pancreatic insufficiency, there is not only a defective lipolytic phase but also an impaired micellar phase. The output of bile salts is decreased because of increased fecal loss. Furthermore, a significant percentage of bile salts precipitate because the duodenum is acidic and there is a large predominance of glycine conjugates. Although much less work has been done on the absorptive phase of patients with pancreatic insufficiency, there is tentative evidence that defective phospholipid absorption, essential fatty acid deficiency, and protein malnutrition could impair the absorptive phase, particularly chylomicron formation. Although significant advances have been made in our understanding of factors responsible for malabsorption associated with pancreatic insufficiency, much remains to be done for the further delineation of defects. It is hoped that this will lead to further refinements of enzyme preparations and to new strategies of intervention.

Cystic Fibrosis↗
PubMed1987

Nutritional therapy of Crohn's disease in childhood.

Crohn's disease is a chronic, incurable inflammatory bowel disease commonly diagnosed in childhood and adolescence. Growth failure represents a common, serious complication unique to the pediatric age group. Although the etiology of growth failure is multifactorial, malnutrition due to inadequate nutrient intake is the primary cause. Recent studies have demonstrated that nutritional supplementation through an enteral or parenteral route restores body composition and reverses linear and ponderal growth failure. The development of elemental diets that can be administered nasogastrically at home has afforded a more practical, less expensive, and less hazardous method of providing Crohn's disease patients with nutritional supplementation and bowel rest. Elemental-diet therapy has also been shown to be a safe, effective method of inducing a remission in acute Crohn's disease. Further studies are required to develop optimal nutritional therapy which may sustain long-term remission in this disease.

Child↗
PubMed1987

Malabsorption, hypocholesterolemia, and fat-filled enterocytes with increased intestinal apoprotein B. Chylomicron retention disease.

Eight infants presented with a malabsorption syndrome, normal fasting triglycerides, hypocholesterolemia (64.3 +/- 10.0 mg/dl), and deficiency of vitamins A and E. Plasma low-density lipoprotein, apolipoprotein B, and apolipoprotein A-I were decreased. After a fatty meal, plasma triglycerides did not increase and chylomicrons could not be identified. Lipoprotein composition was characterized by normal apoproteins, high phospholipids, and low cholesterol. Increased triglycerides were present in low-density lipoproteins. Immunoperoxidase localization of apolipoprotein B on fasting biopsy specimens showed increased staining of the lipid-laden intestinal epithelial cells compared to normals. On electron microscopy after a fat load, the enterocytes contained large numbers of fat particles vesiculating the endoplasmic reticulum. These particles, morphologically similar to chylomicrons, were also present as aggregates of well-individualized lipid droplets within dilated vesicles in the Golgi zone, but were not seen in the intercellular spaces and lacteals. This recessively transmitted condition differs from abetalipoproteinemia and from the homozygous form of hypobetalipoproteinemia and may be caused by a defect in the final assembly of chylomicrons or in the mechanism of their exocytosis.

Apolipoproteins B↗
PubMed1987

Effect of chronic administration of taurolithocholate on bile formation and liver ultrastructure in the rat.

In some cholestatic syndromes, lithocholic acid (LCA) has been identified in serum and bile and might play a role in the pathogenesis of cholestasis. Thus, we examined the effect of chronic LCA administration on hepatobiliary function in rats. The taurine-conjugate of LCA (TLCA) was given to male rats at the dose of 50 mg/kg body weight i.v. twice daily for 18 days. Bile flow, biliary secretion rate of bile acids, phospholipids and cholesterol, measured 15 h after the last injection, were normal with the exception of phospholipid, which was significantly higher when compared to controls. Individual bile acids measured by GLC showed that the contribution of chenodeoxycholic and muricholic acids increased while that of cholic acid decreased. By electron microscopy, bile canalicular structures appeared normal except for a widening of the pericanalicular ectoplasm. Evaluation of hepatobiliary function 1 h after an additional injection of TLCA to rats that received the bile acid for 18 days, resulted in the typical acute cholestatic response. Thus chronic administration of TLCA does not influence the acute cholestatic effect of TLCA.

Animals↗
PubMed1987

Primary sclerosing cholangitis in children: study of five cases and review of the literature.

Primary sclerosing cholangitis in five children is described and 78 cases in the pediatric age group are reviewed. In 24% of the cases, primary sclerosing cholangitis is not associated with an underlying disease and may appear to be prolonged cholestasis of infancy. When an associated condition is present, chronic inflammatory bowel disease, in particular ulcerative colitis, is most common (47%). Histiocytosis X and a variety of immune disorders account for 15% and 10% of cases, respectively. Primary sclerosing cholangitis should be considered in the differential diagnosis of chronic liver disease in the pediatric age group, even in young infants. Results of this survey demonstrate that neither clinical features nor liver function tests are reliable diagnostic predictors, that histologic changes are often nonspecific, and that cholangiography is essential to establish the correct diagnosis.

Adolescent↗