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Biomedical subjects

K Jung

Publications and source records attributed to K Jung.

At least 217 records · Page 12Linked to original sources

Synthesis of L-carnitine by microorganisms and isolated enzymes.

L-Carnitine, a quaternary ammonium compound, plays an important role in beta-oxidation of fatty acids in mammals. The increasing demand for this compound in medicine has led to the development of numerous procedures for L-carnitine production. This review discusses the possibilities of microbial and enzymatical synthesis of L-carnitine and gives an overview on the pathways of L-carnitine metabolism and related enzymes in microorganisms.

Acyltransferases↗

Excretion of urinary enzymes after extracorporeal shock wave lithotripsy: a critical reevaluation.

The excretion of the urinary enzymes alanine aminopeptidase, alkaline phosphatase, gamma-glutamyl-transferase and N-acetyl-beta-D-glucosaminidase, and the 99mtechnetium-diethylenetriaminepentaacetic acid isotope clearance were studied in 35 patients treated with extracorporeal shock wave lithotripsy (ESWL*). Enzyme measurements were made before and consecutively on days 1, 2 and 5, and at 3 months after treatment. A control group investigated at the same intervals was included. Posttreatment enzyme values were not significantly different from those before treatment except for alkaline phosphatase on day 1 after ESWL. Some individuals had short-term increases of enzymuria that were greater than biological variations in the control group. The transient changes of enzymuria after ESWL had no predictive value for kidney function, since no decreased renal function was observed in individual patients with high enzyme excretions after ESWL.

Acetylglucosaminidase↗

Characterization of murine monoclonal antibodies to phospholipase A2 and mellitin from bee venom.

9 murine monoclonal antibodies (MoAbs), 7 to phospholipase A2 (Pla2; Api m I) and two to mellitin (Api m III) have been produced. Specificities were demonstrated using immunoblotting and enzyme immunoassays (ELISA). Antibodies specific for Pla2 were characterized in detail. Epitope mapping of Pla2-specific MoAbs identified three independent binding regions. 5 selected MoAbs bound to one of these sites compete with specific human IgE. Two of MoAbs characterized are suitable tools to quantify Pla2 in a two-site binding assay.

Animals↗

Effect of storage temperature on the activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase in rat liver and kidney homogenates.

The behavior of the catalytic activities of the enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and glutathione reductase was tested in rat liver and kidney homogenates stored at 4, -20 and -70 degrees C and in corresponding tissue samples stored at -70 degrees C. The stabilities of enzymes were different for various enzymes and were dependent on the organ (liver, kidney) and the storage temperature. The storage temperature of -70 degrees C guaranteed the best stability and the five enzymes investigated were sufficiently stable in preserved tissue samples or in homogenates prepared with conventional mannit/sucrose homogenization solution. Under such conditions, these enzymes were stable over at least 4 or 1 weeks, respectively.

Animals↗

Rapid screening of low molecular mass proteinuria: evaluation of the first immunochemical test strip for the detection of alpha 1-microglobulin in urine.

A new semiquantitative immunochemical test strip for urinary alpha 1-microglobulin, a marker protein for tubular proteinuria, was assessed. This test strip has four colour zones, reflecting alpha 1-microglobulin concentrations of ca. 10, 25, 50, and 80 mg/l. alpha 1-Microglobulin concentrations were measured by means of the test strip and an immunonephelometric method in 330 samples collected as the second voided morning urine. The reading time of the test strip must be strictly observed. Reading one minute earlier or later than the 5 min stated in the instructions led to misclassification of over 70% of the results. Correlation between both methods was highly significant, with a Spearman rank correlation coefficient of rs = 0.84 (P < 0.001). There was a partial overlap of the test strip results in different concentration ranges. An elevation of alpha 1-microglobulin was defined as > 25 mg/l, calculated as the upper limit of the central 95% interval of alpha 1-microglobulin concentration in urine samples measured in a previous study of 304 healthy adults. Using this definition of alpha 1-microglobulin elevation, a sensitivity of 97.5%, specificity of 73.6%, a false-positive rate of 16.6%, and a false-negative rate of 0.9% of the test strip results were obtained. A fraction of 82.4% of the 330 samples investigated was correctly classified as having increased alpha 1-microglobulin concentration or not. Methodical improvements of the test strip are necessary to reduce overlapping results, in order to make the test suitable for screening purposes.

Humans↗

Severe infectious complications in a girl suffering from atopic dermatitis were found to be due to chronic granulomatous disease.

Recently, the diagnosis of a variant form of chronic granulomatous disease (CGD) could be established in an 11-year-old girl who had been treated for atopic dermatitis for many years. In addition to severe superinfections of lesions of the skin, the following symptoms were found currently or in her history: an episode of chronic diarrhoea (suspected as lactose intolerance), an endomyocarditis, a paranephritic abscess and recurrent lymph node abscesses. This case is demonstrated to underline the importance of extensive immunologic diagnostics in situations of recurrent severe infections of the skin, especially if other organs are involved. Diagnosis and type of CGD were strongly indicated by flow cytometrical measurement of H2O2 and cytochrome b558-expression by neutrophils and confirmed by a Western blot test. No immunoreactive p47phox could be found in the patient's cells. In this autosomal recessive variant of CGD some retained ability of phagocytes to produce reactive oxygen intermediates was present. Special management of patients with CGD is necessary to prevent serious infectious complications. Genetic counselling is another important consequence of the correct diagnosis.

Child↗

A case of juvenile form Pompe's disease manifested as chronic alveolar hypoventilation.

We describe a case of the juvenile form of Pompe's disease that presented as primary alveolar hypoventilation due to respiratory muscle involvement. This 17-year-old girl had been asymptomatic until this admission, although she had a delayed puberty. Arterial blood gas analysis, pulmonary function test as well as physical findings were compatible with chronic alveolar hypoventilation syndrome. Since she had lower extremity muscle weakness and pseudomyotonic discharge on electromyography a muscle biopsy was done, which revealed glycogen storage disease. The patient was managed successfully with nasal intermittent positive pressure ventilation.

Adolescent↗

Urinary proteins and enzymes as early indicators of renal dysfunction in chronic exposure to cadmium.

We tested the diagnostic sensitivity of various urinary analytes for detecting cadmium-induced nephropathy at an early stage. We investigated 73 healthy persons (control group 1) and individuals exposed to cadmium, either environmentally (n = 36, risk group 2) or occupationally (n = 62, exposed group 3). All data were related to limits of the central 95% reference intervals of the control group. The serum creatinine and ribonuclease values, indicators of the glomerular filtration rate, were not different in the three groups. In the exposed persons (group 3), proximal tubular indicators (low-M(r) proteins lysozyme, ribonuclease, retinol-binding protein, and alpha 1-microglobulin) were more often increased than the glomerular indices (higher-M(r) proteins transferrin, IgG, and albumin). Both the low-M(r) proteins and tubular enzymes were differently altered in their excretion rates. Alanine aminopeptidase, alkaline phosphatase, and N-acetyl-beta-D-glucosaminidase increased even in the risk group 2. alpha 1-Microglobulin was increased in the exposed persons whose cadmium excretion was < 5 mumol/mol creatinine. The combined determination of alpha 1-microglobulin and N-acetyl-beta-D-glucosaminidase exceeded the corresponding upper reference limits in 30% of group 2 and 39% of group 3. We recommend screening for these two analytes to detect cadmium-induced renal dysfunction at an early stage.

Acetylglucosaminidase↗

Sandwich enzyme immunoassay of cystatin C in serum with commercially available antibodies.

We developed a sandwich enzyme immunoassay for determining cystatin C in serum by using commercially available antibodies. We optimized each assay step (e.g., concentrations of coating rabbit anti-human cystatin C antibodies and horseradish peroxidase-conjugated antibodies) and studied the binding kinetics of antigen and antibodies. The within-assay CV was < 5%, the between-assay CV was 8.8%, the detection limit was 0.9 microgram/L, and the assay can be performed within 2 h. Cystatin C concentrations in sera from men were significantly higher than in women (mean and SD: 2.14 +/- 0.31 vs 1.78 +/- 0.26 mg/L). We studied the cystatin C concentrations in sera of 31 outpatients with suspected kidney damages to characterize the behavior of this low-M(r) protein as a possible indicator for estimating the glomerular filtration rate. The correlation with the values obtained by a standard isotopic method involving 99mTc-diethylenetriaminopentaacetic acid was rs = -0.89. The diagnostic sensitivity of cystatin C was 88.2% of that of the standard isotope clearance method and better than those of the conventional serum indicators of reduced kidney function, beta 2-microglobulin (64.7%) and creatinine (52.9%).

Adolescent↗

Cyclosporine A inhibits ATP net uptake of rat kidney mitochondria.

The adenine nucleotide content of mitochondria varies at several physiological and pathological situations. Both net transport and intramitochondrial catabolism of adenine nucleotides has been suggested to be responsible for these changes. Here, the influence of cyclosporine A on the ATP net uptake of isolated rat kidney mitochondria was examined. The ATP net uptake of mitochondria depleted of matrix adenine nucleotides by pyrophosphate treatment was inhibited by cyclosporine A showing a I50 value of about 4 nmol/mg mitochondrial protein. Because intramitochondrial adenine nucleotide content is important for several mitochondrial functions such as oxidative phosphorylation, Ca2+ homoeostasis and mitochondrial biogenesis, it is concluded that the inhibition of adenine nucleotide net transport and a decrease of adenine nucleotide content may be involved in the immunosuppressive and nephrotoxic effects of cyclosporine A.

Adenosine Diphosphate↗

Comparative evaluation of a new molecular method for typing Staphylococcus epidermidis.

The discriminatory powers of several techniques for typing Staphylococcus epidermidis were evaluated in an epidemiological study of bacteria isolated from intensive care patients and from neonates. Genomic DNA fingerprinting using BclI restriction endonuclease was an effective epidemiological marker. The distinct restriction fragment profiles produced with this enzyme were highlighted with specific probes in a Southern blot technique. Cloned Escherichia coli rRNA gene probes proved to have lower discriminatory power and be less suitable for intraspecies typing. However, a panel of random genomic Staphylococcus epidermidis DNA clones provided almost the same level of discrimination as the DNA fingerprinting technique and also provided a clearer profile. DNA and gene fingerprinting techniques were reproducible and highly discriminatory compared to typing based on antigen and plasmid profiles, antibiotic susceptibility patterns and biotypes.

Blotting, Southern↗

Stimulation of nitrogen and whole-body protein metabolism in growth hormone-deficient children by recombinant human growth hormone: relationship to growth.

The effect of a mammalian-cell-derived recombinant human growth hormone (rhGH) on nitrogen and whole-body protein metabolism was assessed in 12 children with complete growth hormone (GH) deficiency. All the patients received single oral doses of 15N-glycine (95 atom % 15N), 20 mg/kg body weight, prior to and following 7 days of treatment with rhGH, 1.7 IU/m2 body surface area (BSA) per day, administered subcutaneously. Prior to rhGH, mean urinary 15N-nitrogen excretion was 42.8 +/- 8% of the administered dose, which fell significantly to 22.8 +/- 7% during rhGH administration (p < 0.0001). Stimulation of protein metabolism by rhGH resulted in a protein net gain rate of 1.1 +/- 0.4 g/kg/day, which was significantly higher than the 0.6 +/- 0.5 g/kg/day rate seen prior to rhGH (p < 0.001). In patients subsequently placed on daily subcutaneous injections of rhGH 1.7 IU/m2 BSA, mean height velocity standard deviation score (HV SDS) for chronological age significantly increased from -3.8 +/- 2.6 to +8.5 +/- 3.1 and +3.3 +/- 2.2, during the 1st and 2nd years of treatment, respectively. However, there was no correlation between the long-term response to rhGH treatment and the short-term changes in nitrogen or protein metabolism in GH-deficient children.

Adolescent↗

Adaptational increase of liver glutathione content during long-term application of cyclosporine A may attenuate toxic side effects.

The concentrations of reduced and oxidized glutathione and of adenine nucleotides were determined in liver, kidney and heart of rats during long-term (four weeks), high-dose therapy with cyclosporine A. In liver and kidney the concentration of oxidized glutathione increased following 4 weeks-therapy suggesting increased formation of free radicals and accelerated lipid peroxidation processes. These processes may be due to an increased activity of the cytochrome P-450 system. Compensatory levels of reduced glutathione were also increased. The adaptational increase of the tissue level of reduced glutathione, presumably the response to a chronic oxidative stress, was more distinct in the liver. The liver did not lose adenine nucleotides. In contrast the kidney, after 4 weeks of cyclosporine A therapy, lost 25% of the adenine nucleotides. These findings suggest that the liver is characterized by a greater potential for effective adaptation to oxidative stress conditions compared to the kidney. These adaptations may prevent distortions of energy and nucleotide metabolism in the liver which is in agreement with the minor ultrastructural changes we have observed.

Adaptation, Physiological↗