Biomedical subjects

A Sedlmayer

Publications and source records attributed to A Sedlmayer.

8 recordsLinked to original sources

PubMed1993

Clinical value of determination of urokinase-type plasminogen activator antigen in plasma for detection of colorectal cancer: comparison with circulating tumor-associated antigens CA 19-9 and carcinoembryonic antigen.

We determined urokinase-type plasminogen activator antigen (u-PA), gastrointestinal cancer-associated antigen (CA 19-9), and carcinoembryonic antigen (CEA) in the plasma of patients with colorectal cancer at the time of clinical tumor detection and in a group of patients with Crohn's disease and analyzed the specificity of these tumor markers. u-PA, CA 19-9, and CEA were indicative for colorectal cancer in 75.5%, 51.5%, and 51.5% of tumor patients, respectively, with a specificity of 79.3%, 94%, and 97.5%. Sensitivity increased when two or all three markers were determined in identical blood samples, whereby a combination of u-PA and CEA exhibited the highest sensitivity value (90.9%) as compared to the combinations of u-PA and CA 19-9 or CA 19-9 and CEA. The use of all 3 markers did not lead to further increased sensitivity. False negative results were obtained in 3 of 32 cancer patients (9.1%, using one of 3 markers as indicative for malignant disease). These results indicate the benefit of multiparametric tumor marker analyses including u-PA antigen for the diagnosis of colorectal cancer.

Adult↗

PubMed1993

Dietary regulation of rat intestinal angiotensin-converting enzyme and dipeptidyl peptidase IV.

The small intestinal brush-border membrane contains several peptidases that are involved in the hydrolysis of dietary peptides containing proline. A high-proline (gelatin) diet was administered to one of several groups of rats to study its possible regulatory effect on levels of two prolyl peptidases, namely angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP IV). Groups of rats were maintained on isocaloric diets containing either low (4%), normal (17%), or high (50%) protein (casein) or high (50%) gelatin. After 7 days, brush-border membranes and total RNA were prepared from the small intestine. ACE activity was 3- to 10-fold higher in brush-border membranes from the gelatin group compared with the low-protein group. DPP IV exhibited a three- to sixfold increase. Immunoblot analysis of brush-border membrane-associated ACE protein indicated a six- to eightfold increase in the high-gelatin group. There was also a 1.5- to 3-fold increase in steady-state levels of ACE and DPP IV mRNA. These results suggest that a diet high in proline (gelatin) is particularly effective in increasing intestinal levels of these two enzymes.

Animals↗

PubMed1992

Biosynthesis and degradation of altered immature forms of intestinal dipeptidyl peptidase IV in a rat strain lacking the enzyme.

We have used a strain of rat (Fischer 344) lacking brush border membrane dipeptidyl peptidase IV activity to examine its effect on the intestinal assimilation of prolyl peptides. In addition, we have examined the biochemical basis for the enzyme deficiency. An analysis of several brush border membrane hydrolases in different regions of the small intestine demonstrates that these rats lack only dipeptidyl peptidase IV. They also have a greatly reduced ability to hydrolyze and absorb in vivo peptides of the NH2-X-Pro-Y type which are known substrates for the enzyme. Immunoblot analysis with polyclonal and monoclonal antibody indicates that the animals lack an identifiable dipeptidyl peptidase IV protein in intestinal epithelial cells. Levels and types of dipeptidyl peptidase IV mRNA were analyzed in several tissues and found to be similar to that of control animals. Biosynthetic labeling of intestinal explants revealed that two distinct forms (102 and 108 kDa) of dipeptidyl peptidase IV are initially synthesized by deficient rats, in contrast to the single protein (106 kDa) observed in normal animals. Pulse-chase labeling experiments (+/- endoglycosidase H) show that these two altered forms of dipeptidyl peptidase IV, although initially glycosylated with N-linked high mannose carbohydrate, fail to be processed to the mature complex glycosylated form and undergo intracellular degradation.

Amino Acid Sequence↗

PubMed1992

Rat intestinal angiotensin-converting enzyme: purification, properties, expression, and function.

Angiotensin-converting enzyme [ACE (peptidyl-dipeptidase A, EC 3.4.15.1)] was purified from a total cell membrane fraction of rat intestinal mucosa. A 4,500-fold purification was achieved after affinity chromatography with lisinopril-Sepharose and gel filtration. The final preparation was judged to be homogenous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent molecular weight of 160,000. The purified protein is a glycoenzyme containing 12% N-linked carbohydrate. Purified ACE had a specific activity of 65 U/mg protein with benzoyl-Gly-His-Leu as substrate. A kinetic analysis showed that the enzyme had the maximal velocity with substrates containing proline at the COOH-terminal end. Inhibitor studies indicated that the enzyme is a metalloprotein. Along the proximal-distal axis of the small intestine, ACE activity is most predominant in the proximal to middle portions, decreasing toward the distal end. This pattern was also observed for ACE mRNA and protein, suggesting that ACE expression is controlled at the level of mRNA. Perfusion of benzoyl-Gly-His-Leu in vivo through a segment of intestinal jejunum demonstrated that ACE is an important intestinal dipeptidyl carboxypeptidase, participating in the digestion and assimilation of dietary peptides.

Amino Acid Sequence↗

PubMed1989

[Critical evaluation of fructosamine as a control parameter in the assessment of diabetic metabolic regulation].

For some years the glycosylated plasma proteins, the so-called fructosamines, have been used for the evaluation of metabolic control in diabetic patients. We studied the usefulness of fructosamine as an intermediate parameter in the control of diabetes and we also corrected fructosamine for serum protein. Furthermore, the dependence on daily times and amounts of food intake were examined for fructosamine alone as well as for protein-corrected fructosamine. Both parameters showed a statistically significant correlation with HbA1C (r = 0.7; P less than 0.001). Changes in the metabolic state of the diabetic patients were reflected more rapidly by both these parameters than by HbA1C. While the correction of fructosamine for serum protein eliminated its postprandial increase in the diabetic patients, circadian variation remained unchanged.

Adolescent↗

PubMed1987

Effect of captopril on renin and blood pressure in cirrhosis.

In hepatic cirrhosis neurohumoral vasoconstrictor systems are activated to compensate for circulatory disturbances. To study the renin-angiotensin-aldosterone system in more detail, angiotensin converting enzyme in 15 patients with advanced liver disease was inhibited with captopril after moderate sodium restriction. Captopril caused an increase in plasma renin activity (p less than 0.005) and a decrease in plasma aldosterone (p less than 0.025) from an elevated baseline, and a moderate drop in systolic (p less than 0.025) and diastolic (p less than 0.05) blood pressure. Hyperreninaemia after captopril was inversely related to the prevailing plasma sodium level (r = -0.66, p less than 0.01), and the changes in both systolic and diastolic blood pressure were correlated with baseline plasma renin activity (r = 0.49, p less than 0.05 for systolic and r = 0.71, p less than 0.01 for diastolic blood pressure). No change occurred in heart rate or in stimulated plasma noradrenaline and vasopressin levels. The data suggest that in these cirrhotic patients the reactivity of the renin-angiotensin-aldosterone system was still intact, although it occurred at a higher level. They confirm the importance of the renin-angiotensin-aldosterone system in arterial blood pressure regulation in cirrhosis.

Adult↗

PubMed1985

[Anti-T in children].

In the serum of 245 newborn children, 165 elder children, and 50 grown-up persons, the antibody against the antigen T (Thomsen-Friedenreich-antigen, Transformation-antigen, T-receptor) has been determined. In 24,8% of the newborn, it was possible to find anti-T, which might be a cause of so far unclear hemolysis in this age. The investigation of sera from children between 1 and 17 years has shown, that anti-T is already present in children aged one year and reaches the level it usually has in grown-up people at the age of 4.

Adolescent↗

PubMed1983

[Hemolytic transfusion incident caused by a Kidd-antibody, anti-Jka].

A severe haemolytic transfusion reaction due to anti-Jka, is described. The antibody was not detected in the cross-match test in saline and 22% bovine serum albumin after incubation at 4, 20 and 37 degrees C. This observation shows that the indirect antiglobulin test (= indirect Coombs reaction), which is able to reveal such antibodies, should be routinely performed in all cases with a history of transfusion and/or pregnancy.

Acute Kidney Injury↗