Biomedical subjects

H Wisser

Publications and source records attributed to H Wisser.

At least 55 records · Page 3Linked to original sources

PubMed1985

[Pseudothrombocytopenia--an error in the determination of thrombocyte count].

Automated counting resulted in erroneously low numbers of platelets (pseudothrombocytopenia) in three patients. The machine-derived values (ELT-8) were initially 30 000, 8000 and 8000/microliter, respectively. Numerous agglutinates could be demonstrated in the counting chamber. Whereas counting in the first patient showed a real value with an average of 252 000/microliter both the other preparations could not be counted due to numerous agglutinates. The artificially low number of platelets in the counter can thus be explained by lack of recognition as platelets due to the size of the in vitro formation of agglutinates. Should these be of the size of white cells leukocytosis may be suggested. Formation of agglutinates was not limited to use of EDTA as anticoagulant but could also be observed with other anticoagulants such as heparin and citrate. For prevention of superfluous and potentially dangerous therapeutic steps the diagnosis of platelet deficiency should be ascertained in any case by additional determination of the platelet count in the counting chamber.

Adult↗

PubMed1985

Effect of intravenous ketanserin on plasma catecholamines and renin activity in normal volunteers.

In a placebo controlled, single blind, randomized cross over study catecholamines (CA) and renin activity (PRA) in plasma were measured in 2 female and 4 male healthy volunteers, at rest in the supine position, following a single intravenous injection of 0.15 mg/kg ketanserin (K) and placebo (P, 10 ml saline). K caused a significant increase in the area under the plasma norepinephrine (NE) time curve (AUCNE) from 13,200 to 18,100 ng X 1(-1) X min for 1 hour after the injection. The area under the plasma epinephrine (E) time curve (AUCE) was also increased but to a lesser extent; it was significantly elevated from 54 to 68 ng X 1(-1) X min for 1 minute after the injection. Dopamine (DA) and PRA did not show any significant response to ketanserin. Following the P injection, none of the four parameters showed any significant change.

Adult↗

PubMed1985

The relationship of free and conjugated catecholamines in plasma and cerebrospinal fluid in cerebral and meningeal disease.

The concentration of free and conjugated norepinephrine (NE), epinephrine (E) and dopamine (DA) were measured by a modified radio-enzymatic assay in the plasma and in the cerebrospinal fluid (CSF) of 45 patients with normal and in 21 patients with disturbed blood-CSF barriers. In patients with an undisturbed blood-CSF barrier the free NE and E in CSF were 128 +/- 45 ng/l and 27 +/- 20 ng/l (mean values +/- S.E.), respectively, and represented about 50% of the average plasma values. Mean DA was not different in plasma (47 +/- 22 ng/l) and in CSF (41 +/- 19 ng/l). Both in plasma and in CSF, considerable higher free catecholamine (CA) levels were measured in patients with dysfunction of the blood-CSF barrier. In one patient with bacterial meningitis twofold higher concentrations of free NE and DA in CSF as compared with plasma were detectable. Sulfate conjugates of catecholamines are predominant in plasma and CSF. The contribution of conjugated CA to total CA in plasma from patients with normal blood-CSF barrier averaged 69.7%, 63.1% and 98.1% for NE, E and DA, respectively and was significantly lower in the CSF (p less than 0.001). In patients with disturbed blood-CSF barrier, the increases of conjugated CA were more pronounced in CSF than in plasma. Further, the contribution of conjugated NE and E to total NE and E in CSF was not only increased in patients with bacterial meningitis, but also in patients with renal insufficiency compared to the "control" patients (p less than 0.02 and p less than 0.001 resp.). Free and conjugated NE, E and DA in the plasma and CSF were related significantly (p less than 0.01 resp.) with stronger correlation for conjugated CA (p less than 0.001 resp.). These results together with findings in the literature, suggest that there is little or no rostral-caudal gradient in CSF CA conjugate concentrations and that even in patients with intact blood-CSF barrier plasma conjugated CA concentrations influence those in CSF. Thus only free CA levels in CSF may reflect the central adrenergic activity.

Adult↗

PubMed1985

Catecholamines in the plasma and urine of patients with alcoholic liver damage under resting and exercise conditions.

Heart rate and plasma catecholamines were determined in 16 patients with alcoholic fatty liver and 14 patients with alcoholic cirrhosis of the liver. The measurements were performed at rest and after exercise on the bicycle ergometer, on average 11 days after admission to hospital. In comparison with a control group, the mean heart rate of the patient group was significantly increased at rest and under graduated loading. Significantly increased plasma catecholamine concentrations under resting conditions were observed in both groups of patients, the increase being more pronounced in the cirrhotics (increased with progressive liver damage, significant differences being found between the control group and each of the two groups of patients). During exercise under a load of 50 or 100 watts, the increases in adrenaline, noradrenaline and dopamine concentrations were greatest in patients with alcoholic cirrhosis. With reference to the initial values, however, the increases in concentration were identical in all three groups. In the patients, metabolism of the catecholamines remained unchanged after an average of 11 days abstinence from alcohol; they showed a significantly diminished elimination of vanillylmandelic acid in the urine and, compared with the greatly elevated plasma catecholamine levels, they showed only a moderate increase in the excretion of catecholamines. The results reported here support the assumption that changes in catecholamine metabolism compatible with an increased sympathetic activity are present in chronic alcoholics without advanced liver damage.

Adult↗

PubMed1985

Altered plasma catecholamines and numbers of alpha- and beta-adrenergic receptors in platelets and leucocytes in hyperthyroid patients normalized under antithyroid treatment.

We measured plasma catecholamines, alpha- and beta-adrenoreceptor numbers and the accumulation of cyclic adenosine monophosphate (cAMP) in the unstimulated state and in response to 10 mumol/l (-) isoproterenol in blood cells from 29 euthyroid controls and from 18 patients with spontaneous hyperthyroidism. In the thyrotoxic patients plasma norepinephrine (1.14 +/- 0.5 nmol/l) and epinephrine (0.3 +/- 0.14 nmol/l) were significantly decreased compared with plasma norepinephrine (1.87 +/- 0.7 nmol) and epinephrine (0.41 +/- 0.19 nmol/l) in the controls (P less than 0.01 and P less than 0.05, respectively) and the values obtained in subjects rendered euthyroid by antithyroid treatment (P less than 0.001, respectively). alpha-adrenoceptor density in platelet membranes obtained from patients in the hyperthyroid state (114 +/- 38 sites per cell) was significantly decreased when compared with controls (159 +/- 48 sites per cell, P less than 0.01) and the values from patients under effective antithyroid treatment (136 +/- 35 sites per cell, P less than 0.01). On the contrary, a significant increase in beta-adrenoceptor density in mononuclear leucocyte (MNL) membranes was found in hyperthyroid patients (1751 +/- 237 sites/cell) when compared with controls (1510 +/- 351 sites/cell, P less than 0.05) and the same patients following antithyroid treatment (1455 +/- 260 sites/cell, P less than 0.001). The equilibrium dissociation constants (KD) did not change in hyperthyroidism. Basal cAMP concentrations in MNL were higher in untreated thyrotoxicosis (45 +/- 18 pmol/10(6) cells/10 min) than in patients in the euthyroid state (35 +/- 9 pmol/10(6) cells/10 min, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗

PubMed1985

[Analytical and technical reliability of the ELT-8 laser hematologic counter].

The ELT-8 laser haematological cell counter is a fully mechanized instrument, which measures the forward scatter of light from a helium-neon laser caused by suspended particles. The apparatus has high practicability, and uses a very small sample volume of 100 microliters. The operational procedure is simple and quickly learned. In the second year of operation, down time for the instrument was, on average, 8 hours/month. Depending on the parameter, the precision of the measurements are between 0.5 and 4% in series, and 1-9% day-to-day. The highest scatter of results was shown for thrombocyte counting, but this may be due to instability of the control samples. There was no carry over between samples containing different concentrations of any of the measured parameters. Lipaemia and haemolysis of samples can lead to false results or false interpretation of results. Cold agglutinins, active against erythrocytes and thrombocytes, can cause significant interference, and this influence can be recognized from discrepancies between the erythrocyte count and haemoglobin concentration or mean corpuscular volume (MCV), and from the presence of thrombopenia in the absence of clinical symptoms (pseudothrombopenia). In such cases a histogram is useful. The stability of 72 blood samples was investigated during storage for 4 days at 4 degrees C. The erythrocyte count was very stable, whereas thrombocyte and leukocyte counts sometimes showed irregular variations. The apparatus gives a linear response up to the following limiting values: leukocytes 85 X 10(9)/l, erythrocytes 8 X 10(12)/l, thrombocytes 10(12)/l, haemoglobin 230 g/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Agglutinins↗

PubMed1984

Influence of food intake on concentrations of plasma catecholamines and cortisol.

Plasma concentrations of epinephrine, norepinephrine, dopamine and cortisol were determined in four healthy volunteers--resting completely in bed--before and after food intake. Meals were provided at 17.00 h on the first day and at 12.00 h on the second day of the test. Blood samples were drawn every 15 minutes. Epinephrine, norepinephrine, dopamine, and cortisol showed a clear dependence on food intake. After the meals plasma concentrations of the four analytes showed rises, which were more pronounced after lunch at 12.00 h than after dinner at 17.00 h. An increase of epinephrine was observed shortly before meal-times; this could be caused by physiological adaptation to the usual rhythm of food intake and reflex response to expectation of the meal.

Adult↗

PubMed1984

Problems in the development of radioimmunoassay of catecholamines.

This review describes experiments to produce antibodies towards the catecholamines and some catecholamine metabolites with the intention of developing radioimmunological methods. First, attempts to produce antibodies to the catecholamines themselves are described. In the course of synthesis of immunogens of catecholamines, it was necessary to exercise special care - e.g. the introduction of protecting groups - owing to the great susceptibility of the catechol structure to oxidation. Despite many efforts, only one working group (Miwa et al.) has reported in a series of papers the successful production of antibodies to catecholamines, but they did not develop a radioimmunoassay. In contrast, antibodies to some metabolites of the catecholamines - such as 3,4-dimethoxyphenylethylamine, the 3-O-methylated catecholamines (normetanephrine, metaneprine, and 3-methoxytyramine) as well as 3-methoxy-4-hydroxyphenylethyleneglycol - have been produced, whose avidity and specificity were high enough to permit the development of sensitive radioimmunoassays.

Antibody Specificity↗

PubMed1983

Plasma free and conjugated catecholamines in diagnosis and localisation of pheochromocytoma.

In six patients urinary excretion of vanillylmandelic acid and catecholamines (CA) could establish the diagnosis of pheochromocytoma. Free norepinephrine (NE) in plasma was within the normal range in two patients and plasma free epinephrine (E) was only marginally elevated in one of them. The degree of CA conjugation was not altered and scattered as in controls and was therefore not complementary to the usual determination of plasma free CA. The intermittent nature of CA secretion by the tumour could be demonstrated by multiple blood samplings during a 48-h study period in two patients, e.g. normal plasma values might be associated with pheochromocytoma if measurements are made during a trough. Thus a single peripheral CA determination cannot be of discriminative value in the diagnosis of pheochromocytoma unless it shows marked elevation. Ten patients subjected to intracardial measurements and five patients suspected of having a pheochromocytoma underwent venous catheterisation to determine their free and conjugated plasma CA. In controls CA values near the orifices of adrenal veins differed enormously and partly overlapped with corresponding levels of patients with pheochromocytoma. In one patient with surgically proven left adrenal tumour highest concentrations of CA were measured in the vena cava superior. These high CA concentrations, caused by paroxysmal release of CA by the tumour arouse suspicion of an additional, ectopic tumour. Because venous catheterisation cannot be relied on implicitly we propose computed tomographic scanning as a first step in localisation of a pheochromocytoma.

Adrenal Gland Neoplasms↗

PubMed1983

Catecholamines, renin, aldosterone and arterial pressure in patients on chronic hemodialysis treatment.

To assess the interaction between adrenergic activity and blood pressure regulation, plasma catecholamines (CA), plasma renin activity (PRA) and plasma aldosteron (PA) were measured in 66 normal subjects and 18 dialysis patients. Prior to dialysis, blood levels of free norepinephrine (NE), epinephrine (E) and PRA were normal, but total (free and conjugated) CA as well as PA were significantly elevated. There was a spectrum of response during hemodialysis. On an average mean arterial blood pressure (MAP) fell during the first two hours of treatment, concomitantly followed by an increase in mean NE level. Whereas PRA and PA were highest at the end of treatment, mean free NE returned promptly to predialysis values through the late dialysis period. Severe hypotensive episodes during dialysis were associated with a baroreceptor-mediated adrenergic stimulation. These results indicate a qualitatively normal reaction of dialysis patients to volume removal and the importance of the renin-angiotensin-system in maintaining blood pressure during dialysis.

Adolescent↗

PubMed1982

Urinary protein profiling by high-performance gel permeation chromatography.

We describe a new application of high-performance aqueous gel permeation chromatography for the analysis of human proteinuria. Separations of urinary proteins from normal subjects and patients with renal impairment were performed with TSK G 3000 SW columns. The effects of pH and ionic strength of the eluent on the separation of urinary proteins were investigated. Albumins were selectively separated from urine by affinity chromatography on Blue Sepharose CL-6B. According to the results of clinical investigations, urinary protein pattern derived from gel permeation chromatography revealed a good prediction of the site of renal involvement. Predominant excretion of proteins with lower molecular weight than albumin correlated with tubular damage. Albumin and higher molecular weight protein patterns wer associated with glomerular disease. Absorbance measurements of the eluent at 280 nm were used for quantitative determination of total urinary protein. Gel permeation chromatography was compared to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the resulting protein patterns are in good agreement.

Chromatography, Gel↗

PubMed1982

Determination of urinary vanilmandelic acid and homovanillic acid by high performance liquid chromatography with amperometric detection.

A method was developed for the simultaneous determination of urinary vanilmandelic acid and homovanillic acid, which included a two step prepurification and a reversed-phase high-performance liquid chromatography with amperometric detection. Conditions were evaluated for performing measurements with the amperometric detector free from electric interference. The method was linear between 2.5 and 100 mumol/l vanilmandelic acid and homovanillic acid with good precision (CV always less than 10%). The correlation between the present determination of vanilmandelic acid and the procedure of Pisano et al. ((1962) Clin. Chim. Acta 7, 285-291) was very good (r = 0.931). No interfering substances could be detected.

Chromatography, High Pressure Liquid↗

PubMed1982

The determination of calcium, glucose, urea and uric acid using the Kodak EKTACHEM multilayer film technology: an evaluation.

Calcium, glucose, urea and uric acid determinations on the "'Kodak Ektachem Four Chemistry Analyzer" were tested for precision and an estimation of the accuracy was performed with our laboratory routine methods using patients' sera and proficiency fluids. Precision -- examined over a period of six weeks -- was very good. Even the very stringent claim of the College of American Pathologists (CAP) -- that analytical dispersion should be less than 1/16th of the normal range -- was fulfilled in almost all control samples. The results from patients' sera measured using both the Ektachem and the routine laboratory methods showed very good correlation. Proficiency fluids tested for calcium, glucose and uric acid all resulted in values well within the assigned interval. Some negative bias was noted for the urea determination however. This could not be completely eliminated even though the samples had been reconstituted with a bicarbonate solution according to the manufacturer's instructions. The linear range of the four determinations was checked: calcium is linear up to 4.2 mmol/l, glucose up to 33 mmol/l, urea up to 60 mmol/l and uric acid up to 1370 mumol/l. Our results confirmed the long-term stability of analyzer and slides to be so high that one calibration per week is sufficient.

Blood Glucose↗

PubMed1982

Urinary excretion of alanine-aminopeptidase and N-acetyl-beta-D-glucosaminidase during sequential combination chemotherapy.

The urinary excretion of alanine aminopeptidase (EC 3.4.11.2) and N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) was determined in 23 patients with testicular cancer during sequential combination chemotherapy with vinblastine/bleomycin and doxorubicin/cis-platinum. Increases in enzyme excretion were more often noticed during therapy with vinblastine/bleomycin than with doxorubicin/cis-platinum. Moreover, the rises during vinblastine/bleomycin therapy were more pronounced. The enzyme activities varied from the normal range up to the 14-fold of the upper limit of the normal range. With few exceptions, enzyme excretions returned to normal or slightly elevated values before the subsequent course. No renal insufficiency could be detected with the commonly used parameters of renal function such as serum creatinine concentrations and creatinine clearance values, which were determined at irregular intervals.

Acetylglucosaminidase↗

PubMed1982

Circadian rhythm of catecholamines, cortisol and prolactin is altered in patients with apallic syndrome in comparison with normal volunteers.

Circadian rhythms of catecholamines, cortisol and prolactin were investigated in 4 healthy subjects and in 6 patients suffering from an apallic syndrome. The clinical picture of this syndrome is characterized by disturbed consciousness (coma vigile), suspension of the sleeping and waking rhythm, lack of emotional reactions and appearance of primitive motor patterns. With the exception of dopamine a pronounced circadian rhythm was found in the control group for all investigated parameters. Catecholamines and cortisol showed a good correlation in the temporal pattern of plasma concentrations and urinary excreted amounts. In all apallic patients the circadian rhythm of prolactin was abolished. Only in one patient a rhythm of catecholamines and in 2 patients a rhythm of cortisol was still detectable. The data may indicate that the episodic nature of hormone secretion was essentially unaffected by the apallic syndrome. These results are regarded as an indication that endogenous, centrally controlled processes participate in circadian rhythms.

Adolescent↗

PubMed1981

Altered circadian rhythm of catecholamines in patients with apallic syndrome.

Circadian rhythms of catecholamines were investigated in 4 healthy subjects and in 6 patients suffering from an apallic syndrome. The clinical picture of this syndrome is characterized by disturbed consciousness (coma vigile), by suspension of the sleeping and waking rhythm, by lack of emotional reactions and by appearance of primitive motor patterns. 5 of the 6 apallic patients showed an abolished rhythmicity compared with the control group. These results were interpreted as an indication that endogenous, centrally controlled processes are the cause of circadian rhythms.

Adolescent↗

PubMed1981

Urinary excretion of N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase in patients receiving amikacin or cis-platinum.

Urinary excretion of alanine aminopeptidase (EC 3.4.11.2) and N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) was determined for 25-70 days in five patients receiving cis-platinum and for 8-53 days in six patients receiving amikacin. This study was performed to investigate if the excretion of urinary enzymes represents a sensitive parameter for the early detection of toxic kidney damage. The determination of N-acetyl-beta-D-glucosaminidase was carried out by the method of Knoll et al. [13]. The procedure of Mondorf et al. [14] for the estimation of alanine aminopeptidase activity was adapted to the Gemsaec Fast-Analyzer. In both patient groups an increase in the excretion of the two enzyme activities could be demonstrated. In patients receiving amikacin, the excretion of alanine aminopeptidase was always higher than that of N-acetyl-beta-D-glucosaminidase, whereas in three patients receiving cis-platinum it was the opposite. In two cis-platinum patients the excretion of both enzymes was of the same size. The changes during amikacin therapy seem to be reversible, whereas in four cis-platinum patients these changes seemed to be partly irreversible. Serum creatinine concentration was less sensitive than the urinary enzyme excretion for detection of kidney damage.

Acetylglucosaminidase↗

PubMed1981

[Bacteriological examinations using the invagination catheter].

Quantitative and qualitative bacteriological studies have been performed on bladder urines taken by two different technics. Bladder urine was first obtained by suprapubic bladder aspiration. Immediately after the puncture another sample of bladder urine was obtained by the "invagination catheter" (only usable in women) transurethrally. In 80 consecutive parallel studies no differences were found in the bacterial counts, and only one difference were found in bacterial type. From the diagnostic point of view, therefore, the two methods were found to be equivalent. In another series of 52 patients catheterization by the invagination catheter was repeated at least 6 hours later without urination in the meantime. The bacteriologic results in the two corresponding specimens were exactly the same in all patients. Contrary to other transurethral methods, no introduction of bacterial agents into the bladder appears to occur with this method.

Bacteriological Techniques↗