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Biomedical subjects

H Wisser

Publications and source records attributed to H Wisser.

At least 73 records · Page 4Linked to original sources
PubMed1981

Preparation of antibodies to catecholamines and metabolites--syntheses of various immunogens and characterization of the resulting antibodies.

The synthesis of antigens of the haptens p-tyramine, octopamine, synephrine, dopamine, normetanephrine, beta-(3,4-dichlorophenyl)-ethylamine and 3-fluoro-tyramine is described. The coupling of the haptens to the carrier protein was performed either via the side chain by means of succinic anhydride, or through the phenolic ring via an aminomethyl group which was introduced by a Mannich reaction. Antisera to these haptens were produced in rabbits by immunization with these antigens. The antisera were characterized by determination of titer and specificity (p-tyramine, synephrine, normetanephrine). The possibility is discussed of using antisera to p-hydroxyphenylethylamine for a radioimmunological determination of catecholamines.

Animals↗
PubMed1981

Are prostaglandins involved in the antihypertensive effect of dihydralazine?

1. Two female and two male patients with essential hypertension were given dihydralazine plus saline or dihydralazine plus diclofenac intravenously on two separate occasions. The dihydralazine dose (range: 16.2--32.4 mg/2 h) was chosen individually to reduce systolic blood pressure by 20 mmHg from the control value before the investigation; the intravenous diclofenac dose was 75 mg/20 ml of saline for all patients. 2. Dihydralazine decreased diastolic blood pressure more than systolic blood pressure and increased heart rate; diclofenac reduced both of these effects. 3. Dihydralazine increased urinary volume and sodium clearance; both these effects were antagonized by concomitant treatment with diclofenac. 4. Whereas dihydralazine did not influence creatinine clearance appreciably, concomitant administration of diclofenac reduced creatinine clearance. 5. Urinary prostaglandin E2 was reduced by diclofenac. 6. We suggest that dihydralazine-mediated vasodilation is reduced by cyclo-oxygenase inhibition.

Adult↗
PubMed1981

Circadian changes of clinical chemical and endocrinological parameters.

It is known that all forms of life possess biological rhythms. The structure of this biological daily periodicity is caused by endogenous and exogenous factors. The reasons of circadian periodicity are endogenous processes, which can be modified by exogenous factors. This review describes the daily fluctuations of concentrations or excretions of haematologic, clinical chemical and endocrinological parameters. In blood and serum the largest daily variations are found for the concentrations of haemoglobin, potassium, iron, cortisol, testosterone, somatotropin, prolactin, adrenaline and noradrenaline. In contrast to the serum concentrations of the electrolytes sodium, potassium, calcium and phosphate, their urinary excretions demonstrate pronounced daily rhythms with amplitudes being twice as high as the daily means. There is a remarkable phase shift of 180 degrees between phosphate and the cations both in the serum concentrations and urinary excretions. A daily rhythm comparable to the urinary excretion of electrolytes, has been measured for the urinary excretion of adrenaline, noradrenaline and cortisol. A constant, well defined timing of the sampling is important for those constituents with a marked daily variation. For numerous parameters very contradictory results have been reported in the literature concerning their daily variations, especially in cases of less pronounced rhythms. For some parameters the reasons for the differences in the observed daily variations are discussed.

Animals↗
PubMed1981

[Circadian rhythm of free catecholamine excretion in disturbed adrenal function (author's transl)].

The daily time course of urinary catecholamine excretion was determined for hyperactivity of the sympathoadrenal system (3 phaeochromocytomas, 1 neuroblastoma), disturbed adrenal function (M. Addison and partial adrenal insufficiency), bilateral adrenalectomy (one patient), in 8 healthy patients receiving dexamethasone, and in a control group. All groups showed a circadian rhythm of catecholamine excretion. In the patients with phaeochromocytoma, the excretion of catecholamines and vanilmandelic acid showed a shift of phase compared with the control group. In patients with hyperfunction of the sympathoadrenal system, catecholamines and vanilmandelic acid fluctuated with similar amplitudes, whereas in healthy patients vanilmandelic acid and dopamine showed much smaller fluctuations of concentration than adrenaline and noradrenaline.

Adrenal Gland Diseases↗
PubMed1980

Single-isotope enzymatic derivative method for measuring catecholamines in human plasma.

The radioenzymatic determination of plasma catecholamines with a modification of the method of da Prada & Zürcher ((1976), Life Sci 19, 1161-1174) is described. The several reaction steps were optimized with respect to the quantities of substrate and enzyme, and reaction time. There were particular methodological difficulties concerning the blanks, which were determined by using sodium metaperiodate-oxidized plasma. The reliability criteria of the method were determined. Coefficients of variation between 3.4 and 8.6% were found for the intra-assay variability of 10 pg of norepinephrine and 3 pg of epinephrine or dopamine, resp. The recoveries o the three catecholamines ranged from 88-93%. The detection limits were calculated from the standard deviation of the blanks and amounted to 12 ng/l (norepinephrine), 6 ng/l (dopamine) and 3 ng/l (epinephrine). The method was used for the analysis of plasma samples from patients. In a further investigation we examined the stability of plasma catecholamines stored at different temperatures. It was found that samples can be stored for 1-2 hours at room temperature and for several weeks at -27 degrees C without losses in catecholamine content.

Animals↗
PubMed1980

[Diurnal variation of the elevated acid phosphatase activity in cases of prostate carcinoma (author's transl)].

The diurnal rhythm of total acid phosphatase and prostatic phosphatase activities was investigated in patients with prostate carcinoma. In these patients, the activities of total acid phosphatase, the tartrate-sensitive fraction of acid phosphatase, and lactate dehydrogenase decrease after therapy, whereas the activity of alkaline phosphatase increases. In all patients with prostate carcinoma, the total and tartrate-inhibited acid phosphatase, and the level of cortisol show a diurnal rhythm before therapy, with a minimum at night. In one patient, after orchiectomy, the cortisol rhythm remained unchanged, but the daily phosphatase variation was absent. Diurnal variations of lactate dehydrogenase and alkaline phosphatase were also observed in 2 patients without prostate carcinoma, but with elevated levels of these enzymes.

Acid Phosphatase↗
PubMed1980

[Comparative study of the diagnostic value of disc electrophoresis of urinary proteins and measurement of the excretion of N-acetylglucosaminidase for the detection of renal tubule damage in chronic polyarthritis (author's transl)].

A method is described for the determination of the enzyme N-acetyl-beta-D-glucosaminidase in gel-filtered urine. The individual reaction parameters were tested, and the reliability of the method was determined. The stability of the enzyme in urine was investigated at different temperatures over a 6 week period. The excretion of N-acetyl-beta-D-glucosaminidase, like the analysis of urinary proteins by disc electrophoresis, is a sensitive parameter for renal damage. The two methods were compared, using 50 random urine samples from patients with chronic polyarthritis; both methods were found to have equal diagnostic value.

Acetylglucosaminidase↗
PubMed1979

Diurnal variations of estriol and cortisol in serum and urine in late pregnancy with and without fenoterol-therapy.

The serum concentration of unconjugated estriol, total estriol, cortisol in one hour intervals and the urinary excretion of total estrogens and cortisol in three hour intervals was determined in eleven apparently healthy women between 26 and 40 weeks of gestation. They were divided into two groups, in order to study the influence of Fenoterol treatment on the daily variation of the measured parameters. Six patients were treated with Fenoterol and five patients received no medication. Between the two groups no statistical differences could be detected for the measured parameters. Regular and marked diurnal variations in cortisol have been observed, whereas total and unconjugated estriol showed small and irregular daily changes. These daily variations of "estriol" were of the same magnitude as the two-fold methodical standard deviation. For this reason it is not necessary to standardize the sampling time.

Circadian Rhythm↗
PubMed1978

3,4-Dimethoxyphenylethylamine excretion of normals and schizophrenics, behaviour during total fasting.

A specific and sensitive radioimmunoassay for the determination of 3,4-dimethoxyphenylethylamine (3,4-DMPEA) in urine was developed. In 5 fasting healthy volunteers excretion of 3,4-DMPEA was not diminished, indicating that this substance can be regarded as an endogenous metabolite. In addition, the time profile of the excretion of 3,4-DMPEA was measured in one patient during total fasting. In 25 patients with schizophrenic psychoses, 9 psychiatric patients without schizophrenia and 80 control patients excretion of 3,4-DMPEA was compared. No significant differences could be observed between these three groups.

Adult↗
PubMed1978

Methodical investigation of the production of antibodies towards 3,4-dimethoxyphenylethylamine.

In this study the synthesis of various antigens from 3,4-dimethoxyphenylethylamine (3,4-DMPEA) is described. Antigen A was formed by coupling the acylated side chain of 3,4-DMPEA to the protein, while antigen B was synthesized by introducing an acylated amino group to the benzene ring and linking this reactive group to the protein. With antigen A an antiserum with a titer of 1 : 16000 could be raised, while with antigen B coupled to human albumin and bovine gamma-globulin the antiserum had a titer of 1 :1000 and 1 : 4000. Antibodies formed by immunization with antigen A exhibited a high specificity for substituents of the benzene ring, but were less specific for substituents of the side chain. Antibodies formed by treatment with the antigen B were specific for both kinds of substituents. So far, it has not been possible to harvest any specific antibodies towards the corresponding antigens of dopamine.

Animals↗
PubMed1978

[Kinetic assay of creatinine with the Gemsaec-Fast-Analyzer; comparison with the Fuller's earth method (author's transl].

A kinetic method is described for the determination of creatinine in serum. The method is adapted for use with Gemsaec-Fast-Analyzer. The reliability criteria of the method are reported. The only interfering substance is bilirubin, which, when present in elevated concentrations, causes an apparent decrease in the level of creatinine. This interference can be avoided by treating the sample with Fuller's earth prior to the creatinine determination. 72 sera were analysed by the kinetic method and by the Fuller's earth method without deproteinization (5). There was excellent agreement between the two methods (y=1.011 x--0.8222;r=0.9970).

Bilirubin↗
PubMed1978

[Dependence of the serum concentrations of creatinine and urea on the time of day, with normal and impaired kidney function (author's transl)].

Daily variations in the serum concentrations of creatinine, urea and cortisol were studied in 7 patients without kidney or muscle disease, and in 8 patients with impaired kidney function (creatinine clearance less than 40 ml/min). Neither creatinine nor urea showed a circadian rhythm; the daily variations lay within the limits of the methodological scatter. Serum cortisol showed its known circadian rhythm in high amplitude.

Adult↗
PubMed1976

[The determination of cystine aminopoptidase (oxytocinase) with a ENI fast analyzer (author's transl)].

A procedure for the determination of cystine aminopeptidase activity was adapted to a fast analyzer. The various reaction parameters were checked. The precision of the method was about 5%. Cystine aminopeptidase activity was stable for long storage periods at +4 degrees C and -20 degrees C. The normal range for the terminal weeks of pregnancy was determined on samples from female patients with normal pregnancies.

Alkaline Phosphatase↗
PubMed1975

[Calculation of the parameters of the acid-base balance with the aid of a small computer].

The application and modification of a program published by Hardt (1972), Clin. Chem. 18,658--661) for the calculation of the true pCO2, the standard bicarbonate and the base excess are reported. 217 Determinations of a random patient sample were evaluated graphically, with the aid of a nomogram of Siggaard-Andersen, and mathematically with a computer program. There was good agreement between the two evaluation methods.

Acid-Base Equilibrium↗