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Biomedical subjects

G Strohmeyer

Publications and source records attributed to G Strohmeyer.

At least 145 records · Page 8Linked to original sources
PubMed1987

Insulin binding to erythrocytes in hyperinsulinemic patients with precirrhotic hemochromatosis and cirrhosis.

This study investigated insulin receptor binding (number and affinity) to erythrocytes in patients with precirrhotic hemochromatosis, patients with cirrhosis, and healthy subjects. To evaluate plasma glucose and insulin levels, an oral glucose tolerance test (OGTT) was performed in all subjects. In the fasting state, all patients exhibited normal glucose levels. Precirrhotic patients showed slight impairment of glucose tolerance while cirrhotic patients were strikingly glucose intolerant. In both patient groups, fasting plasma insulin levels were increased. Following the glucose load, plasma insulin levels were significantly enhanced in precirrhotic patients at 90 and 120 min and increased at all times in cirrhotic patients. In the postabsorptive state (in the presence of hyperinsulinemia) insulin binding and the number and affinity of insulin receptors of erythrocytes were not different in precirrhotic or cirrhotic patients when compared to controls. We conclude that studies of insulin binding on erythrocytes do not contribute to the evaluation of the pathogenesis of insulin resistance in liver disease.

Blood Glucose↗
PubMed1987

Haemochromatosis.

Explore the source record for details and available documents.

Diabetes Mellitus↗
PubMed1987

Iron uptake by rat duodenal microvillous membrane vesicles: evidence for a carrier mediated transport system.

The mechanism of iron translocation from intestinal lumen to portal plasma is poorly understood. To examine these processes, uptake of Fe2+ and Fe3+ by rat duodenal microvillous membrane vesicles prepared by a Ca2+ precipitation procedure was studied. Membrane aliquots were incubated with increasing concentrations of 59FeCl3 in the presence of a one-thousand-fold molar excess of citrate or 59FeSO4 with a twenty-fold molar excess of L-ascorbic acid. After various time intervals the incubation reaction was stopped by addition of 0.1 mM FeCl3 (4 degrees C), and uptake of 59Fe was determined by a vacuum filtration assay. Initial uptake velocity of 59FeCl3 and 59FeSO4 was determined from the slope of the cumulative uptake curves, which was linear for the first 60 s. Initial uptake rates of both, 59Fe3+ and 59Fe2+ revealed an identical saturable uptake component with a Km of 19-22 nM and Vmax of 8 pmol min-1 mg protein-1. In addition, transport of Fe2+ revealed a linear unspecific uptake phase, which was predominant at high substrate concentrations. Saturable uptake of Fe2+ and Fe3+ was temperature dependent, and significantly reduced by trypsin pretreatment of the microvillous membrane vesicles, indicating the involvement of a protein in the uptake process. This suggestion was pursued by isolation of an iron binding protein from duodenal brushborder membranes. After solubilization of microvillous plasma membranes with 1% Triton X 100, affinity chromatography of the membrane protein mixture over an iron chelate gel derived from epoxy activated Sepharose and elution with 50 mM EDTA yielded a single 52,000 dalton protein. The protein co-chromatographed over an Ultro-Pac TSK G 3000SW HPLC column together with 59FeCl3 and 59FeSO4. It showed no immunologic activity to rabbit antibodies against whole rat serum or rat transferrin. Furthermore, by photoaffinity labelling technique a single iron binding protein with a molecular weight of about 52,000 dalton was identified in microvillous membranes of the rat duodenum. These data are compatible with the hypothesis that intestinal iron absorption is mediated by a specific carrier-dependent transport system.

Animals↗
PubMed1987

[Role of Pseudomonas maltophilia and "Pseudomonas like bacteria group Va" in the etiology of Crohn disease].

In 1976, Parent and Mitchell isolated cell-wall defective bacteria of the species Pseudomonas maltophilia and Pseudomonas like bacteria group Va from resected bowel tissue of 8 consecutively operated patients with Crohn's disease. The control group, which included patients with ulcerative colitis, was negative in this respect. The isolated strains were available for our own investigations. New Zealand white rabbits were inoculated with killed bacteria to produce specific antisera. Frozen sections of affected tissue from 6 consecutively operated Crohn patients were incubated with the various antisera and investigated by indirect immunofluorescence. No positive reactions were demonstrable in repeated tests with different dilutions of antisera. Our results do not support the hypothesis that bacteria of the species Pseudomonas maltophilia and Pseudomonas like bacteria group Va are an etiologic factor in Crohn's disease.

Bacteriological Techniques↗
PubMed1987

Crohn's disease in a married couple.

The aetiopathogenesis of Crohn's disease is still unknown. Multiple occurrence of inflammatory bowel disease among blood relatives of patients with either Crohn's disease or ulcerative colitis is seen much more frequently than would be expected by chance alone, whereas reports on the development of these diseases in spouses are very rare. We describe such a case here, and suggest that chance, rather than an infectious agent, is behind such occurrences.

Adult↗
PubMed1987

[Methodologic studies of N-acetylneuraminic acid determination in human gastric juice].

Mucus protects the gastric mucous membrane from aggressive substances in the gastric juice. It consists of glycoproteins, the composition of which determines its ability of viscosity, adhesiveness, and cohesiveness. There is a special interest in sialic acids, which are found mostly in humans as N-acetylneuraminic acid (NANA). NANA is estimated by the thiobarbituric acid method. A special feature of this method is that only free sialic acids are estimated. A mild acid hydrolysis is necessary in order to measure the total NANA-content. Some conditions of the hydrolysis are investigated with respect to the special properties of the gastric juice. Hydrolysis sulfuric acid 0.01 mol/l results in an about 10% higher yield than hydrolysis with hydrochloric acid 0.01 mol/l. A maximal yield of hydrolysates is found when the gastric juice pH is adjusted to 2.0. After 45 minutes hydrolysis at 80 degrees C in a water bath there is for at least 60 minutes a constant NANA-concentration in the gastric juice samples. Human bile has no influence on the estimation with the thiobarbituric acid method. In regard to these conditions of hydrolysis pentagastrin (6 micrograms/kg KG s. c.) does not change the NANA-secretion over 60 minutes in patients with duodenal ulcer. During an intragastric bile salt infusion the NANA-output remains unchanged over 45 minutes.

Duodenal Ulcer↗
PubMed1986

Hepatic alcohol metabolizing enzymes after prolonged administration of sex hormones and alcohol in female rats.

To study the effect of sex hormones and alcohol on the hepatic activities of alcohol metabolizing enzymes, estradiol or testosterone were administered for 4 weeks to ovarectomized or sham operated adult female rats pair-fed nutritionally adequate liquid diets containing either alcohol (36% of total calories) or isocalorically replaced carbohydrates. Estradiol increased the hepatic activities of alcohol dehydrogenase and catalase in both ovarectomized and sham operated female rats on the control diet, whereas this enhancing property was virtually lost in animals on the alcohol diet. The hepatic activities of the microsomal ethanol-oxidizing system remained unaffected under these experimental conditions irrespective of the diet used. Testosterone increased the hepatic activities of the microsomal ethanol-oxidizing system and of catalase and decreased the alcohol dehydrogenase activity in female rats on the control diet, but these changes were either not reproducible or markedly reduced in similarly treated female rats fed the alcohol diet. Thus, sex hormones may strikingly influence the hepatic activities of alcohol metabolizing enzymes, but the changes are modulated by prolonged alcohol consumption.

Alcohol Dehydrogenase↗
PubMed1986

Monozygotic triplets with Crohn's disease of the colon.

Female monozygotic triplets all developed Crohn's disease within a period of 11 mo. The monozygosity was demonstrated by analysis of 24 genetic markers of different chromosomal localization. Crohn's disease was diagnosed using clinical, radiologic, and endoscopic findings. Histologic evaluation of bowel tissue was consistent with Crohn's disease. All 3 patients had colon involvement; the terminal ileum appeared normal. The patient in whom Crohn's disease was first diagnosed had the severest course. Our observations support the role of a genetic influence in the manifestation of Crohn's disease. Nevertheless, environmental factors or microorganisms, or both, have to be taken into account, perhaps as factors promoting the outbreak of Crohn's disease.

Adult↗
PubMed1986

Hepatocellular uptake of oleate is energy dependent, sodium linked, and inhibited by an antibody to a hepatocyte plasma membrane fatty acid binding protein.

Several studies suggest that a portion of hepatocellular nonesterified fatty acid uptake may be carrier mediated. To further investigate this process, initial rates (Vo) of [14C]oleate uptake into rat hepatocytes, isolated by collagenase perfusion and incubated at 37 degrees C with oleate in the presence of bovine serum albumin, were studied as a function of the concentration of unbound [14C]oleate in the medium. Vo was saturable with increasing unbound oleate concentration (Km = 8.3 X 10(-8) M; Vmax = 197 pmol per min per 5 X 10(4) hepatocytes) and was not inhibited by up to 40 microM sulfobromophthalein, taurocholate, or cholic acid. Oleate uptake was sodium dependent. Vo was significantly diminished when Li+, K+, choline, or sucrose were substituted for Na+ in the incubation medium and was reduced 46% by 1 mM ouabain. Uptake was also markedly reduced after exposure of cells to metabolic inhibitors (e.g., 2,4-dinitrophenol, carbonyl cyanide m-chlorophenylhydrazone, antimycin, KCN). To evaluate the physiologic significance of the previously isolated rat liver plasma membrane fatty acid-binding protein, the effect of an antibody directed against this protein on hepatocellular [14C]oleate uptake was examined. Preincubation of hepatocytes with the IgG fraction of this antiserum inhibited Vo of [14C]oleate by up to 65% in dose-related fashion, without altering Vo for [35S]sulfobromophthalein, [14C]taurocholate, or [3H]cholate. These data indicate that at least a portion of hepatocellular oleate uptake is energy dependent, sodium linked, and mediated by a specific liver plasma membrane-fatty acid-binding protein.

Animals↗
PubMed1986

[Acquired immunologic deficiency syndrome (AIDS) and other sexually transmissible diseases with gastrointestinal manifestations].

Various kinds of gastrointestinal symptoms are seen in connection with AIDS. Furthermore, because of special sexual practices, other sexually transmitted diseases are found, especially in the oral cavity, the oesophagus and the anorectum. Whereas in most of the cases infections can be treated successfully under a strict drug regimen, the treatment of malignant lymphomas or Kaposi's sarcoma is problematic. When the digestive tract is affected by the latter diseases, treatment is normally restricted to symptomatic measures. In the future, gastroenterologists will be faced with the above mentioned problems more frequently.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Clinical features of inflammatory joint and spine manifestations in Crohn's disease.

167 patients with Crohn's disease were investigated for joint and spine inflammation. Arthritis was observed in 23 patients (14%), sacroiliitis in 24 (14%), and sacroiliitis in combination with arthritis in 11 patients (7%). 15 patients (9%) had ankylosing spondylitis; 9 of them were HLA-B27 positive (60%). A parallel pattern in the course of bowel disease and joint inflammation was observed in 22 out of 34 patients with arthritis (59%). An association between the localization of Crohn's disease and the type of spondylarthritis could not be demonstrated. Patients with arthritis alone developed erythema nodosum (35%) or aphthous stomatitis more often (21%) than patients without spondylarthritis+ (6% and 12%, respectively). Other extra-intestinal manifestations of Crohn's disease did not reveal any association with the development of spondyloarthritis.

Adolescent↗
PubMed1986

[Insulin resistance in liver diseases].

Coexistence of hyperinsulinemia and normal or impaired carbohydrate tolerance indicates insulin resistance which is frequently observed in patients with liver diseases such as liver cirrhosis, fatty liver, acute and chronic hepatitis and idiopathic haemochromatosis. Insulin resistance in liver diseases can be due to circulating insulin antagonists or a target tissue defect in insulin action, either due to changes in the state of the insulin receptor or due to a postreceptor defect, that means any abnormality in the insulin action sequence following the initial binding step. High insulin levels in liver diseases are caused by diminished degradation of insulin by the liver whereas hypersecretion only plays a minor role under basal conditions. High levels of glucagon, free fatty acids and growth hormone are well known in liver diseases but until now there is no evidence of the pathogenetic importance of these factors. Conflicting results on insulin binding, methodological criticism on binding data and the question whether or not diminished insulin binding on peripheral blood cells plays any physiological role make it unlikely that studies on insulin receptors of peripheral blood cells contribute to the revelation of insulin resistance in liver diseases. The clamp technique allows to quantify the sensitivity of the body to exogenous insulin. The results on liver cirrhosis in connection with studies on glucose metabolism show that under basal conditions insulin insensitivity is due to peripheral resistance (primarily muscle) according to a postreceptor defect. Finally the causes of insulin resistance in liver diseases are still not known.

Blood Glucose↗
PubMed1986

[Etiology of chronic inflammatory bowel diseases].

Furthermore the aetiopathogenesis of inflammatory bowel disease (IBD) is unknown. The familial accumulation makes a genetic disposition probable. Presumably, the development of Crohn's disease and ulcerative colitis is contingent upon several factors, including perhaps environmental factors in the broadest sense. A large number of microorganisms have been implicated, but there is still no convincing proof that any of them have an important role in the aetiopathogenesis of IBD. The observed immunological phenomena are as yet difficult to interpret.

Bacterial Infections↗