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Biomedical subjects

A Scholer

Publications and source records attributed to A Scholer.

At least 37 records · Page 2Linked to original sources
PubMed1984

Evaluation of a colorimetric test for the determination of alpha-amylase with p-nitrophenylheptaoside as substrate.

A continuous method for the determination of alpha-amylase activity with a defined substrate has been published by Rauscher et al. in Berichte der Osterreichischen Gesellschaft für Klinische Chemie 4, 150 (1981). It offers the following advantages: good practicability, easy adaptation to analysers and short incubation time. Twenty-one laboratories took part in a multicentric study on this method, working with different instruments and manual procedures at three temperatures. Additionally, all laboratories participated in a laboratory improvement program, in order to discriminate systematic from accidental errors. Data on imprecision, linearity, interferences and comparability of the method have been presented at a workshop. The resulting coefficients of variation for imprecision in series as well as from day to day were 0.6-6.3% and 1.3-7.7%, respectively. No interferences from bilirubin, glucose, maltose and 37 selected drugs were found. The results from the described method correlate well with those from an UV-test (substrate: maltoheptaose); compared with other methods, however, the expected systematic deviations were observed. Reference values for 25, 30 and 37 degrees C are indicated in this report.

Colorimetry↗
PubMed1983

[Diagnostic value of the determination of serum amylase and serum lipase in suspected acute onset of acute or chronic pancreatitis].

In a prospective study the value of serum amylase and serum lipase determination has been analyzed in 19 patients with an acute episode of acute or chronic pancreatitis and in 19 patients with acute abdomen not due to pancreatitis. The concentration of urinary amylase and the urinary output of amylase in the spot urine as well as after a two-hour collection period have also been examined. The normal values were determined in 21 healthy volunteers and the reproducibility of the various parameters was analyzed after 1 hour and 25 hours in these volunteers. For diagnosis of an acute episode of chronic pancreatitis serum amylase was found to have good sensitivity, but a specificity inferior to that of serum lipase. By contrast, the specificity of serum lipase is excellent. Unlike determination of serum enzymes, measurement of urinary enzymes in all variations does not offer any further advantage. Except for the combination of serum amylase and serum lipase, none of the other tested combinations provides further diagnostic information. The examination of spot urine samples is not inferior to the 2-hour urine specimen. For the time being the combination of serum amylase and serum lipase determination is again recommended for diagnostic routine in patients with an acute episode of pancreatitis.

Abdomen, Acute↗
PubMed1982

[Clinical relevance of N-acetylglucosaminidase determination in urine of kidney transplant recipients with and without cyclosporin A].

From January to September 1981 urinary gamma-N-acetyl-glucosaminidase (NAG) excretion was measured in 23 cadaver kidney recipients up to 90 days posttransplant. Conventional immunosuppression with azathioprine and prednisone was used in 12 patients, and cyclosporin A (CyA) in 11 patients. The purpose of this study was to assess the clinical value of NAG determinations in the diagnosis of acute rejection episodes and CyA-induced nephrotoxicity. A total of 26 acute rejection episodes were observed. 14 (54%) of these were associated with a significant increase in NAG excretion. The other 46 episodes of increased NAG excretion (77% of a total of 60 episodes) were unrelated to acute rejection reactions. No obvious reason was apparent in 39 instances (63%). Nine out of 11 patients treated with CyA showed one or more increases in NAG excretion, but the number of such episodes did not differ between patients with CyA serum concentrations below 500 ng/ml and those with levels above 500 ng/ml. Histological signs of CyA toxicity in graft biopsies correlated well with increased NAG excretion. It is concluded that increases in NAG excretion are not sensitive and specific enough to be of definite help in the diagnosis of acute rejection and/or CyA-induced nephrotoxicity.

Acetylglucosaminidase↗
PubMed1982

[Creatine kinase (CK) activity and its isoenzyme MB in the serum of randomly selected patients without acute coronary disease].

Elevations of creatine kinase (CK) are not specific for myocardial disease. However, enzyme release due to extracardial factors is not necessarily comparable in healthy and diseased persons. It is therefore questionable whether normal values obtained in a group of healthy or mildly ill subjects are also valid for severely ill patients. The activity pattern of CK and its isoenzyme MB was therefore examined in the serum of 100 consecutive patients attending the medical outpatient clinic and of 170 patients at the time of admission to the medical emergency ward. The clinical and laboratory findings and diagnoses for all patients are recorded. Acute coronary disease was excluded. Determination of CK was performed according to the method described by Oliver [21] and Preston [27], but the results were calculated for a reaction temperature of 30 degrees C and determination of CK-MB was in cue with the method described by Prellwitz [25]. 4% of the outpatients and 14% of the emergency patients had CK values of over 100 U/1. In the majority of the patients (19 of 28) with CK values of over 100 U/1, the history revealed that the elevated values could be attributed to skeletal muscle trauma. After these values had been excluded, the 95% percentile was 20-85 U/1 (outpatients) and 20-110 U/1 (emergency ward) for men and 15-90 U/1 (outpatients) and 20-75 U/1 (emergency ward) for women. Without this selection, the newly admitted male patients in particular would have presented considerably elevated values. Since an explanation was found for most of the elevating values, the adjusted figures show no major differences between outpatients and hospital patients. The limit for CK-MB activity indicative of cardiac origin is presumed to be between 4-10% of the total CK activity. However, individual variations are observed, since CK-MB activity in skeletal muscle in variable and atypical isoenzymes may interfere with CK-MB determination. In this study 14% of the patients admitted to the emergency ward with CK values of under 100 U/1 presented false positive CK-MB values of over 10% of the total CK activity. It is concluded that CK-MB determination using the antibody method does not afford reliable results when there is no elevation of total CK.

Adult↗
PubMed1982

Measurement of prostatic acid phosphatase in serum and bone marrow: radioimmunoassay and enzymic measurement compared.

We quantitated the concentrations of prostatic acid phosphatases (EC 3.1.3.2) in serum and bone-marrow aspirates with three commercial radioimmunoassay kits, and the catalytic activities with a thymolphthalein monophosphate-based enzyme test. The enzyme's immunological activity in serum was compared with its catalytic activity for its potential as a detector of early prostatic cancer and its performance as an early marker of metastatic activity in bone. Neither measurement is useful for detecting early stages of prostatic cancer. The spread of carcinoma to lymph nodes or to bone is detected with greater frequency by radioimmunoassay than by the enzymic test. Radioimmunoassay also detected metastasis to the bone more frequently than did physical methods. Analytical and clinical performance of the four methods is described.

Acid Phosphatase↗
PubMed1981

[Test of efficacy of an oxalate-binding anion exchanger Colestid in healthy subjects for use in idiopathic calcium-oxalate urolithiasis].

Sodium oxalate (402 mg) was administered in a single dose to 10 healthy volunteers receiving a controlled diet. Half the group received 3 times 10 g Colestid and the other half 4 times 2 g Andursil. On the 5th day the oxalate load was repeated. Urine was collected within 32 hours following oxalate application in 8 fractions. In each fraction the levels of oxalate, calcium, phosphate and uric acid were determined. The amount of oxalate, phosphate and uric acid measured in the group receiving Colestid was lower in all fractions. Peak excretions of oxalate found in unmedicated volunteers were suppressed following oxalate load. In the group receiving Andursil, only the excretion of phosphate was decreased. The results presented suggest that Colestid may be promising in the prevention of calcium-oxalate-urolithiasis.

Anion Exchange Resins↗
PubMed1981

[Current assessment of radioimmunological determination (RIA) of prostate acid phosphatase in the diagnosis of prostatic cancer].

Sera of patients without any tumors of the prostate and sera of patients with benign and malignant tumors of the prostate were tested with the enzyme assay using thymolphthalein monophosphate as substrate. The results were compared with the RIA of Clinical Assay (Travenol) and found to yield an approximately 50% better recognition of malignant growth. However, false-positive rates were rather high (approximately 20%), which lowers the overall success rate to approximately 30%.

Acid Phosphatase↗
PubMed1981

[Evaluation of test strips for the semi-quantitative screening for proteinurias (author's transl)].

Commercial test strips using the protein error of certain indicators for the colorimetric detection of protein (especially albumin) were compared with a quantitative nephelometric method. The study proved that there is good agreement between the results from the quantitative method and those from the test strips (Rapignost Protein/Combur-8-Test). Both test strips generally shoed a good separation of the segments for semi-quantitative determinations. There was a very good agreement between the test strips in protein-containing urines. In protein-free urines, however, the Combur-8-Test showed a slightly higher proportion of false-positive results.

Colorimetry↗
PubMed1980

[Glucose determination in the hemolysate, manual analysis].

A method for the manual determination of glucose in hemolysate is described. Both hexokinase/G6P-DH (e.g. Glucoquant) and glucose dehydrogenase can be used as reagents. The two methods correlate satisfactorily with an approved method. Correlation with an automated method: Gluc-DH: r = 0,98323; hexokinase/G6P-DH: r = 0,94172.

Blood Glucose↗
PubMed1978

[Diagnostic value of the myocardium-specific isoenzyme creatinephosphokinase (CK-MB)].

In 150 ambulatory and 155 hospitalized patients the normal values for creatine phosphokinase (CK) and the isoenzyme CK-MB were determined using a simple test with inhibiting antibodies. In a series of 100 consecutive patients hospitalized for chest pain, CK-MB was measured over a 72-hour period in 6- to 12-hourly intervals. The results were compared to the clinical findings, ECG, total CK and SGOT. In addition, CK-MB was determined after elective DC countershock and intramuscular injections (12 patients in each group). Normal values for CK-MB were found to be less than or equal to 10 U/1 in all patients, whereas the values for total CK turned out to be male less than 125 U/1, female less than 100 U/1 in ambulatory patients and less than 50 U/1 in hospitalized patients. In 68 of the 100 patients hospitalized for chest pain, acute myocardial infarction was found. The specificity of CK-MB in patients with transmural infarction was calculated as 100%, and the sensitivity as 97%. After DC countershock and intramuscular injections, CK was markedly elevated whereas CK-MB only rose after cardioversion. We conclude that CK-MB may be of considerable value for the differential diagnosis of elevated total CK activities of unknown origin. It is a very specific and a sensitive parameter for the diagnosis and exclusion of acute myocardial infarction.

Creatine Kinase↗