Biomedical subjects

D Ratge

Publications and source records attributed to D Ratge.

47 records · Page 3Linked to original sources

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

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

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 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↗

PubMedDate not supplied

Influence of prostaglandin inhibition on dihydralazine induced acute effects in patients with essential hypertension.

In order to determine whether vasodilator prostaglandins (PG) contribute to the acute vascular and endocrine responses to intravenously administered dihydralazine, we examined its effects on systolic and diastolic blood pressure (BP), heart rate (HR), plasma renin activity (PRA) and the plasma catecholamines (CA) noradrenaline (NA), adrenaline (A) and dopamine (DA) as well as on sodium, potassium and creatinine clearance (CNa, CK and CCr respectively), urinary flow rate, urinary catecholamines (NA, A, DA) and iPGE2 and i6-keto-PGF1 alpha excretion rate in six patients (three females, three males) with essential hypertension before and after PG synthesis inhibition by the nonsteroidal, anti-inflammatory agent diclofenac. Diclofenac, which reduced urinary iPGE2 and i6-keto-PGF1 alpha excretion by 62% (P = 0.026) and 45% (P = 0.037), respectively, antagonized dihydralazine induced diastolic BP reduction (P = 0.0009), HR increase (P = 0.01), noradrenaline and adrenaline increase in plasma (P = 0.02 and P = 0.05, respectively), increase in urine flow rate (P = 0.03), sodium clearance (P = 0.01) and tended to reduce PRA. We conclude that dihydralazine-mediated changes can be reduced by cyclo-oxygenase inhibition, most likely on the basis of a reduction of its effect on peripheral resistance, thereby leading to less reflex activation of the sympathetic nervous and renin-angiotensin systems.

Adult↗

PubMedDate not supplied

Chronic arterial and venous catheterization of conscious, unrestrained rats.

A method is described for implanting arterial and venous cannulas in rats that requires only minor surgery. Catheters are introduced into the abdominal aorta through the ventral tail artery and into the vena cava through a lateral tail vein. The wounds are covered with an acrylic cuff and the catheters are brought out through a stainless steel spiral connected to the cuff and then attached to top of a metabolism cage used to house the rat. This method makes possible continuous access to the catheters in undisturbed, mobile animals. Using this model we compared mean arterial pressure, heart rate, plasma renin activity, and plasma catecholamine levels in freely moving Long-Evans rats and in Brattleboro homozygous rats.

Animals↗