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Biomedical subjects

D Maruhn

Publications and source records attributed to D Maruhn.

At least 37 records · Page 2Linked to original sources
PubMed1982

Comparison of the morphological alteration and disintegration test (MADT) and the chimpanzee infectivity test for determination of hepatitis B virucidal activity of chemical disinfectants.

The morphological alteration and disintegration test (MADT) as a key indicator for Hepatitis B Virus (HBV) inactivation was compared with the chimpanzee infectivity test using three suspensions of HBV differing in the degree of inactivation as judged by electronmicroscopic studies. The results of the MADT and the chimpanzee studies correlated well. Thus, the MADT, evidently, can replace the laborious, costly and time-consuming animal studies for the evaluation of chemical disinfectants for hepatovirucidal activity.

Aldehydes↗
PubMed1980

Spectrometric determination of urokinase in urine after gel filtration, using the chromogenic substrate S-2444.

Using the chromogenic substrate S-2444, the spectrometric determination of urokinase (EC 3.4.21.31) in urine subjected to gel filtration was evaluated. Pure urokinase solutions were used to standardize analytical conditions. A low molecular mass (relative molecular mass < 5000) heat resistant (60 min, 97 degrees C) activity could be removed from urine by gel filtration (Sephadex G 25 Medium). In the analysis of the high molecular mass fraction (relative molecular mass > 5000) of urine, amidolysis remained linear during a period of 3 hours. The relation between enzyme activity and substrate turnover was linear in the range from 0.05-12 U/l. The coefficients of variation for within-run precision ranged from 1.4-3.8%. The analytical recovery was 98-104%. Average urokinase excretion in morning urines (collection period 1-3 hours) of 10 healthy males and 10 healthy females was respectively 0.82 and 0.68 U/g creatinine.

Chromatography, Gel↗
PubMed1979

Evaluation of urinary enzyme patterns in patients with kidney diseases and primary benign hypertension.

The urinary excretion of lactate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, arylsulphatase A, alpha-glucosidase, beta-galactosidase, trehalase, N-acetyl-beta-glucosaminidase, beta-glucuronidase, and leucine arylamidase was studied in 68 patients with biopsy-proved glomerular, 54 with interstitial renal disease and in 97 patients suffering from primary hypertension. The enzyme output of these 219 patients was compared to that of a reference population of 100 thoroughly selected healthy subjects. The highest incidence of elevated enzyme excretion was observed for N-acetyl-beta-glucosaminidase with 88% in glomerulopathies and 78% in interstitial disease, followed by beta-galactosidase. 94% of the patients with glomerular kidney disease, 90% of those with interstitial disease and about 60% of the subjects with primary benign hypertension revealed an output of at least one enzyme above upper reference limit. The highest average enzymuria occured in glomerulopathies, particularly high values in patients with the nephrotic syndrome. Application of discriminant analysis to the urinary enzyme pattern of glomerular and interstitial renal diseases resulted in an overall correct classification into the appropriate group of 89% of all patients. The discrimination between glomerular and interstitial disease was better in patients with normal renal function than in those with reduced function. Results show, that the analysis of urinary enzyme patterns may be a helpful adjunct for differential diagnosis of kidney diseases.

Acetylglucosaminidase↗
PubMed1979

Preparation of urine for enzyme determinations by gel filtration.

The activities of several enzymes in urine are masked by the presence of interfering substances in native urine. From several methods proposed for the removal of low molecular mass interferences dilution, dialysis, gel filtration, and ultrafiltration have been successfully applied. Gel filtration seems to be of these most suitable. I is effective, accurate, precise and economical. Scale-down procedures provide for acceptable speed. By this method the complete separation of lactate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, arylsulphatase A, alpha-glucosidase, beta-galactosidase, trehalase, N-acetyl-beta-glucosaminidase, beta-glucuronidase and leucine arylamidase from low molecular mass substances, e.g. a heat-stable, competitive inhibitor of N-acetyl-beta-glucosaminidase was possible. The preparation and determination of urinary enzymes should be thoroughly standardized and controlled. Acceptable precision (coefficient of variation less than 10% between-day) can be achieved with manual spectrophotometric methods.

Chromatography, Gel↗
PubMed1977

Diurnal variations of urinary enzyme excretion.

Variations in the urinary excretion of arylsulphatase A, beta-galactosidase, alpha-glucosidase and beta-glucuronidase throughout a 24-h period were studied in 8 healthy subjects. Urine was collected at 3-h intervals and enzyme activities were assayed after gelfiltration of the urine specimens. Significant intra-individual changes of the excretion of all 4 enzymes during the 24-h period were found. Enzyme output was high between 3 a.m. and 9 a.m. and low during the afternoon and evening hours. The most striking pattern was seen for arylsulphatase A. Diurnal variations of urinary enzyme excretion seemed not to be flow dependent. Both modes of expression of enzyme output (mU/min or U/g creatinine) gave corresponding results. It is concluded that for the measurement of the excretion of these enzymes urine should be collected during a fixed time interval, e.g. from 6 a.m. to 9 a.m.

Adult↗
PubMed1976

Rapid colorimetric assay of beta-galactosidase and N-acetyl-beta-glucosaminidase in human urine.

Colorimetric methods using 4-nitrophenyl-glycoside substrates for the assay of beta-galactosidase and N-acetyl-beta-glucosaminidase in human urine are described. Interfering substances were removed by gel-filtration of urine. An unidentified low-molecular-weight inhibitor of N-acetyl-beta-glucosaminidase was found. Increased sensitivity of the methods was achieved by high sample volumes, small volumes of buffer to terminate the enzyme reaction and optimal substrate concentration and buffer pH. Incubation periods were shortened to 15 min. Both methods were designed as single-tube tests in which buffer-substrate solutions are prepared in bulk and aliquots are stored in individual containers at -25 degrees C. Under these conditions reagents were stable for at least six months. Precision of both methods was satisfactory. Estimates of normal limits are reported.

Acetylglucosaminidase↗
PubMed1976

Normal limits of urinary excretion of eleven enzymes.

Urinary excretion of lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, arylsulphatase A, alpha-glucosidase, beta-galactosidase, trehalase, N-acetyl-beta-glucosaminidase, beta-glucuronidase, and leucinearylamidase was studies in a carefully selected group of 100 healthy subjects, 50 women and 50 men. Enzyme activities were assayed in 3-h morning samples after gel filtration of the urine. Activities were related to time volume, and to urinary creatinine concentration. Several transforming functions had to be applied to enzyme output data to obtain an approximation to gaussian frequency distribution. Men showed a significantly higher excretion of gamma-glutamyltransferase, alpha-glucosidase, trehalase, N-acetyl-beta-glucosaminidase,beta-glucuronidase, and leucine arylamidase activity than did women if enzyme activity was related to urinary time volume. Women excreted more lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, alpha-glucosidase, trehalase, and N-acetyl-beta-glucosaminidase activity than did men, if urinary creatinine was used as the basis of reference. Reference intervals were calculated as 2.5 and 97.5 percentiles for both sexes.

Acetylglucosaminidase↗