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Biomedical subjects

S W Dziedzic

Publications and source records attributed to S W Dziedzic.

At least 19 recordsLinked to original sources
PubMed1986

Alcohol and hypertension: implications from research for clinical practice.

Despite the fact that recent epidemiological and laboratory studies appear to confirm that alcohol has an effect upon blood pressure, its impact has largely been ignored in clinical practice. This study was undertaken in an effort to answer four basic questions Is there an association between blood pressure and ethanol ingestion and if so is it causal or related to common genetic and/or environmental factors?; If an association exists, what is its likely physiological mechanism?; What additional studies are needed in order to further elucidate the relationship between alcohol and blood pressure?; What clinical recommendations, if any, are justified with our present state of knowledge?

Alcoholism↗
PubMed1983

Effect of guanabenz on blood pressure responses to posture and exercise.

A single dose of guanabenz was examined for effects upon blood pressure, heart rate, plasma catecholamines, and plasma renin activity in a randomized, double-blind, crossover design. Eight patients were studied when supine, standing, and during submaximal exercise. Guanabenz reduced blood pressure in subjects who were supine or standing. Heart rate was lowered only in the supine subjects. Guanabenz induced reduction in plasma catecholamines subjects in all positions and the reduction correlated with the placebo level for both norepinephrine and epinephrine. Plasma renin activity was not significantly affected by guanabenz. The results indicate that the central alpha-agonist action of guanabenz reduces sympathoadrenal function to a greater extent in hyperadrenergic hypertensive patients than in those without this disorder.

Adult↗
PubMed1981

Plasma catecholamines in hypertension and pheochromocytoma determined using ion-pair reversed-phase chromatography with amperometric detection: investigation of the separation mechanism and clinical methodology.

The retention behavior of catecholamines (CAs) in ion-pair reversed-phase chromatography is examined. From the effects of pH, ionic strength and a secondary ion-pairing reagent (citric acid), under our chromatographic conditions, the retention behavior can be explained by assuming a mixed ion-exchange mechanism with octyl sulfate and citrate, on the column and in the mobile phase, respectively. The developed separation method was applied to the analysis of CAs in plasma samples purified by alumina adsorption and detected amperometrically. This method provides the basis for the determination of the short-term magnitude of CA response to physical and physiological interventions, as well as the baseline CA levels in essential hypertension and pheochromocytoma. The results seen for norepinephrine and epinephrine are consistent with eh funcitonal roles of these CAs as hormones or peripheral transmitters.

Adult↗
PubMed1981

Quantitative determination of 3-methoxy-4-hydroxyphenylethyleneglycol and its sulfate conjugate in human lumbar cerebrospinal fluid using liquid chromatography with amperometric detection.

A sensitive and direct reversed-phase liquid chromatographic method with amperometric detection was developed for the determination of 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG). The concentrations of the free and sulfate conjugate of MHPG were measured in human lumbar cerebrospinal fluid. All samples were preconcentrated by extraction with ethyl acetate. Deconjugation of the sulfate form of MHPG was achieved by enzymatic hydrolysis with sulfatase. Peaks were identified on the basis of chromatographic behavior, ratio of responses at several oxidation potentials and the stopped-flow UV spectra of the collected fractions. The free MHPG content of 20 cerebrospinal fluid samples ranged between 0.720 and 19.51 ng/ml with the mean of 5.126 +/- 4.652 (S.D.) ng/ml. The sulfate conjugate of MHPG in 12 samples of cerebrospinal fluid ranged between 0.08 and 0.850 ng/ml with the mean value of 0.2365 +/- 0.2269 (S.D.) ng/ml. Although our results correlate well with the literature values, no attempt was made to interpret the quantitative data since samples were obtained from routine, diagnostic testing of patients admitted to the medical or neurologic services at the Mount Sinai Hospital.

Chromatography, Liquid↗
PubMed1981

Analysis of urinary metanephrines by reversed-phase high-performance liquid chromatography and electrochemical detection.

A sensitive and specific direct analysis of urinary normetanephrine (NMN) and metanephrine (MN) was achieved utilizing reversed-phase high performance liquid chromatography and electrochemical detection. Individual specimens from "control" subjects and those with pheochromocytoma were hydrolyzed and the metanephrines separated from other urinary constituents by elution with ammonia from a Dowex CG-50 resin. Chromatographic peaks were identified by retention behavior, co-chromatography with reference compounds, ratio of responses at various oxidation potentials and stopped-flow UV spectra of the collected fractions. The NMN and MN content for the control subjects was between 0.086 and 0.21 (mean - 0.14) microgram/mg creatinine and 0.012 and 0.092 (mean = 0.039) microgram/mg creatinine, respectively. The values for subjects with pheochromocytoma varied from 1.5 to 27.5 (mean = 9.9) microgram/mg creatinine for NMN and 0.10 to 1.60 (mean = 0.86) microgram/mg creatine for MN. The patient with ganglioneuroma had an NMN of 4.1 and an MN of 0.80 microgram/mg creatinine. While this method permits discrimination between those patients with pheochromocytoma and the overwhelming majority of hypertensive patients, it may ultimately be further extended to separate normal subjects from those with more subtle derangements in catecholamine metabolism.

Chromatography, High Pressure Liquid↗
PubMed1981

Addition of acebutolol to diuretics in hypertension.

The effect of acebutolol as an antihypertensive beta receptor-blocking drug was evaluated in 15 patients that remained hypertensive while on diuretics. Observations were made in a small randomized double-blind trial in which the drug was compared to placebo and subsequently during a single-blind phase when the drug was given to those who had not responded to placebo. The dose range for acebutolol was 200 to 600 mg twice daily. Pretreatment plasma renin activity (PRA) and the response to intravenous saralasin infusion were assessed as predictors of the antihypertensive effect of acebutolol. None of six patients receiving placebo had a response of goal blood pressure or below; six of nine receiving acebutolol did respond (P less than 0.01). Acebutolol treatment induced reduction in diastolic pressure, heart rate, and PRA pooled from both phases of the study. There were no significant correlations between acebutolol therapy. Our data indicate that acebutolol is effective in diuretic-resistant hypertensive patients and that indices of the renin-angiotensin system are not predictors of the therapeutic response.

Acebutolol↗