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Biomedical subjects

K Jung

Publications and source records attributed to K Jung.

At least 325 records · Page 18Linked to original sources
PubMed1986

Diuresis-dependent excretion of multiple forms of renal brush-border enzymes in urine.

The urinary brush-border enzymes alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1) and gamma-glutamyltransferase (EC 2.3.2.2) and their activity pattern of soluble and particulate forms separated by ultracentrifugation were investigated over 8 h after a high intake of fluid (22 ml/kg body wt.). The activity pattern of the two multiple forms was markedly influenced by the urine flow rate. The time-related excretion of soluble forms of these three enzymes increased with the extent of urine output whereas the excretion of particulate form was independent on diuresis. Diuresis-dependent excretion of total activities of brush-border enzymes can be exclusively considered to be a consequence of changed excretion of soluble forms.

Alkaline Phosphatase↗
PubMed1986

An optimized micromethod for determining the catalytic activity of serum ribonuclease.

An optimized assay is described for the catalytic activity determination of serum ribonuclease, using polycytidylic acid as substrate and measuring the released acid-soluble ultra-violet absorbing products. Recommended final reaction concentrations are 0.3 mmol/l polycytidylic acid, 200 mmol/l imidazole/HCl buffer, pH 7.0, and 50 mmol/l NaCl. Optimal concentrations for the precipitation procedure, guaranteeing sufficient precipitation and minimal decomposition of unreacted substrate, are 160 mmol/l perchloric acid and 4 mmol/l lanthanum nitrate. Coefficients of variation for the method (within series and between days) ranged from 2.2 to 7.9%. No sex-related differences of catalytic activity were observed. In 63 blood donors with normal values of serum creatinine, the upper limit of the reference intervals (99th percentile) was 33.7 kU/l.

Adult↗
PubMed1986

Different diuresis-dependent excretions of urinary enzymes: N-acetyl-beta-D-glucosaminidase, alanine aminopeptidase, alkaline phosphatase, and gamma-glutamyltransferase.

We studied how much of the lysosomal enzyme N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) and of the brush-border enzymes alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1), and gamma-glutamyltransferase (EC 2.3.2.2) was excreted in urine over 8 h after a high intake of fluid (22 mL per kilogram of body weight). The hourly excretion of all four enzymes increased with the increasing urine flow rate. The excretion rate of the brush-border enzymes was more markedly influenced than that of N-acetyl-beta-D-glucosaminidase. By relating the enzyme excretion to urinary creatinine we could reduce the variability of brush-border enzyme output and could completely compensate for the effect of diuresis on the excretion of N-acetyl-beta-D-glucosaminidase.

Acetylglucosaminidase↗
PubMed1986

Diagnostic significance of some urinary enzymes for detecting acute rejection crises in renal-transplant recipients: alanine aminopeptidase, alkaline phosphatase, gamma-glutamyltransferase, N-acetyl-beta-D-glucosaminidase, and lysozyme.

We compared the diagnostic validity of five urinary enzymes--alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1), gamma-glutamyltransferase (EC 2.3.2.2), N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30), and lysozyme (EC 3.2.1.17)--as indicators of acute rejection crises in renal-transplant recipients. In 82 patients (group A), the excretion of each of these five enzymes was measured daily from transplantation until discharge from hospital. In another 69 patients (group B), enzyme determinations were made when the patient came for regular checkups (about every four to eight weeks). We used an "activity ratio" (the activity measured at a particular time compared with the activity on the preceding determination) value of 1.5 as the decision point. In group A, use of this discrimination point for alanine aminopeptidase, gamma-glutamyltransferase, and N-acetyl-beta-D-glucosaminidase yielded a specificity and sensitivity of about 90%. In group B, only alanine aminopeptidase had a greater diagnostic sensitivity than creatinine alone. Evidently, measurement of alanine aminopeptidase can be a helpful indicator of acute rejection crises, when interpreted in combination with other available relevant clinical, biochemical, and immunological data.

Acetylglucosaminidase↗
PubMed1986

[The intravenous 15N metabolism test in assessing the effect of parenteral feeding on protein synthesis].

It is possible to investigate the influence of parenteral applicated L-amino acids on protein metabolism of whole organism by the help of 15N-tracer technique in this paper described. We can determine the utilization of nitrogen parenteral applicated quantitatively. On the basis of graphical methods the protein synthesis rate can be calculated. We get this from mathematical models, based on 3-pool-model. The calculation bases on 15N-elimination in urine after intravenous infusion of 15N labeled amino acids solution during the time of 24 h (endproduct method). We describe 3 graphical methods, using the so-called values of plateau of cumulative 15N-excess amount (96 h) (plateau method A) or 15N abundance after 24 h (plateau method B) and the slope of the curve of 15N excess, amount at 24 h ('slope' method). By the help of these methods the therapeutical nutritive conceptions can be evaluated.

Amino Acids↗
PubMed1985

Influence of cyclosporin A on the respiration of isolated rat kidney mitochondria.

In vitro exposure of isolated rat kidney mitochondria to cyclosporin A, a new immunosuppressive agent with serious nephrotoxic side-effects, leads to alterations of both succinate- and glutamate plus malate-supported respiration in a dose-related manner. ADP- and 2,4-dinitrophenol-stimulated respiration, respiratory control indices, and ADP/O ratios are decreased. The mitochondrial alterations are discussed as possible pathogenetic reasons of cyclosporin A nephrotoxicity.

Adenosine Diphosphate↗
PubMed1985

Phosphatidic acid phosphatase activity in subcellular fractions of normal and dystrophic human muscle.

Biopsy samples from normal and dystrophic human muscle (Duchenne type) were fractionated by differential centrifugation and microsomes, mitochondria and cytosol were assayed for phosphatidic acid phosphatase (EC 3.1.3.4) and marker enzymes of mitochondria and cytosol. The activity of phosphatidic acid phosphatase was significantly lower in microsomes and higher in cytosol and mitochondria of dystrophic muscle than in the corresponding subcellular fractions of normal muscle. The results support an explanation of earlier findings that there is reduced G3P incorporation into diglycerides and phosphatidylcholine and a qualitative and quantitative change in the amount of phosphatidylcholine in dystrophic microsomes. The possible reasons for the reduction in the activity of only microsomal PA-P-ase were discussed.

Animals↗
PubMed1985

A liver-function test using 15N-labelled ammonium chloride.

Malfunction of the liver involves disturbances of urea synthesis and ammonia detoxification. These phenomena became apparent, especially during ammonia loading of patients. The functional state of the liver can be assessed by oral administration of 15NH4Cl and subsequent analysis of 15N-urea and 15N-ammonia in urine by emission spectrometry. Clinical tests based on the ratio of the excess abundances of 15N-ammonia to 15N-urea excreted in urine 3 h after oral administration gave values for patients with liver disease which differed significantly from those for healthy subjects. Absorption disturbances, which often accompany liver diseases, do not influence the effectiveness of the method.

Aged↗
PubMed1985

Changed enzyme activities in rat kidney during ischemia.

Marker enzyme activities of different subcellular fractions were analyzed in cortex homogenates from rat kidney after different periods (15, 30, 60, and 90 min) of warm ischemia. Lactate dehydrogenase, alanine aminopeptidase, N-acetyl-beta-D-glucosaminidase, and succinate-cytochrome c reductase were not altered by ischemia in these periods. ATPase (2,4-dinitrophenol-stimulated and azide-sensitive), 5'-nucleotidase, K-Mg-nitrophenylphosphatase decline within 30 min of ischemia, whereas the microsomal enzymes glucose-6-phosphatase and NADPH-cytochrome c reductase decreased not before 60 min of ischemia. The early decrease of ATPase and of plasma membrane enzymes can be regarded as a consequence of membrane alterations. This enzymatic approach may be helpful to evaluate pharmacological agents for preventing and reserving ischemic effects in kidneys in a rational manner.

4-Nitrophenylphosphatase↗
PubMed1985

Diagnostic significance of urinary enzymes in detecting acute rejection crises in renal transplant recipients depending on expression of results illustrated through the example of alanine aminopeptidase.

In 82 renal transplant recipients we measured the excretion of urinary alanine aminopeptidase (EC 3.4.11.2) activity daily after transplantation until patients' discharge from hospital. Enzyme excretion was expressed as volume activity (U/L), time-related output (U/4h) and in relation to the excreted creatinine. Diagnostic sensitivity, specificity, efficiency and likelihood ratios were calculated from all three expressions with regard to diagnosis of acute rejection crises. The term "enzyme activity per creatinine excreted" has the highest diagnostic potential.

Acute Disease↗
PubMed1985

Observations of HDL components in female probands following an ultra-long distance run of 100 miles.

The serum concentrations of total cholesterol and triglycerides as well as the cholesterol, phosphatidyl choline, and apolipoprotein components of HDL were tested in 19 participants immediately before and immediately after a 100-mile run. After the run, taking into account any alterations in total protein, the following changes were observed: a decrease in total cholesterol (p less than 0.001), as well as in triglycerides (p less than 0.05), and an increase in HDL cholesterol (p less than 0.05), and HDL phosphatidyl choline (p less than 0.01). The concentrations of HDL apolipoprotein A-I and HDL apolipoprotein A-II were not affected. The results indicate a change in composition of HDL following extreme prolonged physical exercise in women.

Apolipoprotein A-I↗
PubMed1985

[Characteristic respiratory magnitude of isolated mitochondria of the rat kidney cortex in relation to measurement conditions].

Respiration speed, respiratory control index and ADP/O-quotient are important characteristics of mitochondria. Since their numerical values much differ in literature, the influence of the composition of the measuring medium on these parameters was established. In their value the parameters are particularly determined by the Mg2+ and the phosphate concentration as well as by the pH-value of the medium. For the investigation of the characteristics a medium of the following composition is recommended: 210 mmol/l saccharose, 10 mmol/l KCl, 10 mmol/l KH2PO4, 60 mmol/l tris(hydroxymethyl)aminomethan (pH 7.40), 0.5 mmol/l ethylene diamine tetra-acetic acid.

Adenosine Diphosphate↗
PubMed1985

Mitochondrial enzymes in human serum: comparative determinations of glutamate dehydrogenase and mitochondrial aspartate aminotransferase in healthy persons and patients with chronic liver diseases.

We measured the activities of two mitochondrial enzymes, the mitochondrial form of aspartate aminotransferase (EC 2.6.1.1) and glutamate dehydrogenase (EC 1.4.1.2), in the serum of apparently healthy persons (n = 84) and patients suffering from chronic liver diseases (n = 43). The distribution of activities for glutamate dehydrogenase, but not mitochondrial aspartate aminotransferase, was sex-dependent. The upper limits of the reference intervals (99th percentile) at 37 degrees C were 3.2 U/L for mitochondrial aspartate aminotransferase, 6.4 U/L for glutamate dehydrogenase (women), and 11.0 U/L for glutamate dehydrogenase (men); there was a weak correlation between the activities of both mitochondrial enzymes (r = 0.439). In patients with chronic liver diseases we found a greater increase in the activity of glutamate dehydrogenase than of mitochondrial aspartate aminotransferase and the correlation between the two mitochondrial enzymes was stronger. The diagnostic sensitivity and specificity of either mitochondrial enzyme was less than that of total aspartate aminotransferase, alanine aminotransferase (EC 2.6.1.2), or gamma-glutamyltransferase (EC 2.3.2.2).

Adult↗
PubMed1985

[Lipid composition of microsomes and mitochondria of the rat kidney cortex].

The lipid content, phospholipid composition and fatty acid composition of the predominant phospholipids were determined in cortical mitochondria and microsomes of rat kidney. Microsomes have a higher lipid content than mitochondria due to their higher content of phospholipid and cholesterol. Both subcellular fractions differ in their phospholipid composition. Phosphatidylcholine and phosphatidylethanolamine form together about 80% and 60% of total phospholipid in mitochondria and microsomes, respectively. The fatty acid patterns of the major phospholipids in mitochondria and microsomes are very similar. Our detailed data will be a well founded basis for studying the influence of pathological events on the lipid composition of kidney.

Animals↗