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Biomedical subjects

K Engelman

Publications and source records attributed to K Engelman.

At least 37 records · Page 2Linked to original sources
PubMed1988

Side effects of sympatholytic antihypertensive drugs.

Antihypertensive drugs with pharmacological action due to sympatholytic activity have been second only to diuretics in their use and efficacy in normalizing blood pressure. Their pharmacological actions have resulted in the notable absence of chemical toxicity, but because of symptomatic side effects, their use has been limited relative to some of the newer antihypertensive agents. Most prominent among undesirable side effects are the central nervous system findings of sedation, altered thought process, depression, and orthostatic or exercise hypotension. Sexual problems, especially in men, are also prominent. Special toxicity is discussed with reference to methyldopa, clonidine, monoamine oxidase inhibitors, and metyrosine.

Female↗
PubMed1987

Failure to compensate decreased dietary sodium with increased table salt usage.

This study tested the extent to which individuals placed on a lowered sodium diet would compensate for the reduced dietary sodium by adding table salt to their food. Eleven students, unaware that their use of saltshakers was being studied, consumed all their meals and snacks in a clinical research center for 13 weeks. During the first three weeks and the last week (week 14), the diet contained approximately 135 mmol/d (135 mEq/24 h) of sodium, which was reduced to approximately 70 mmol/d (70 mEq/24 h) during weeks 4 through 13. A preweighed saltshaker was available for use throughout the entire 14-week period. Evaluations of salt taste preference and intensity scaling were conducted at regular intervals. Subjects compensated only slightly for the reduction of dietary sodium, making up less than 20% of the decrement with increased saltshaker usage. No changes in taste function were found. A substantial reduction in dietary sodium is possible if lowered-sodium foods are consumed in conjunction with ad libitum table salt.

Adult↗
PubMed1987

Fluorometric documentation of increased cutaneous blood flow after topical application of a PGE2 analog in man.

The present study employed fiberoptic fluorometry, a noninvasive means of documenting delivery and removal of fluorescein dye, to evaluate the local circulatory changes elicited by topical application of DHV-PGE2 ME, an investigational PGE2 analog. On Day 1, inactive vehicle was applied to a 5 X 4 cm study site on each thigh of healthy volunteer subjects (n = 12). Symmetrical perfusion was confirmed by similar determinations of dye delivery and removal at each site. On Day 2, DHV-PGE2 ME, 30 or 120 micrograms, was applied to one site while inactive vehicle again was applied to the other. After administration of 120 micrograms in a petrolatum vehicle, fluorometry detected a pronounced increase in nutritive perfusion. There was significant acceleration of dye delivery and removal (p less than 0.05 by ANOVA). Less pronounced changes were noted after the lower dose of DHV-PGE2 ME and when the drug was applied in a triethyl citrate vehicle. The local circulatory changes were not accompanied by systemic effects; there were no changes in vital signs or in fluorometric indices at remote sites.

Adolescent↗
PubMed1986

The influence of moderate reduction in dietary sodium on human salivary sodium concentration.

Twenty-four healthy subjects were placed for 12-13 weeks on diets that reduced average sodium intake from 145 to 74 m-equiv. Na+/day as determined by multiple 24-h urine collections before and during the diet. Whole-mouth resting and stimulated saliva was collected and analysed for flow rate and sodium concentration several times before and during the low-sodium period. Sodium restriction did not influence salivary flow rates but salivary sodium levels fell 25 per cent for resting and 17 per cent for stimulated saliva. Thus moderate reductions in sodium intake are accompanied by significantly lower salivary sodium levels.

Adult↗
PubMed1986

Increasing dietary salt alters salt taste preference.

In previous studies with humans, moderate reduction of dietary sodium decreased preference for salty foods. It had been hypothesized that this occurred via reducing taste stimulation with salty foods. Taste function after increasing dietary salt (NaCl), either with or without increasing salt taste stimulation, was examined in two experiments. In Experiment 1, one group of subjects was required to add crystalline salt to food daily for 4 weeks. A second group ingested salt tablets for the same period. A third group ingested a placebo. Whereas urinary sodium excretion increased in both groups ingesting supplemental salt, the concentration of salt in soup rated as tasting most pleasant increased only in the group adding salt to food. Rated intensity of salt did not change. In Experiment 2, salt supplementation was extended to 6 weeks and taste function was tested more extensively. At the end of the experiment, the concentration of salt in soup rated as tasting most pleasant increased in the group which added the crystalline salt to food. This group also added more salt to soup to taste than did the salt tablet group. The most pleasant concentration of KCl in soup was not significantly affected. Taken together these two experiments suggest that the preferred concentration of salt in soup can be increased after dietary salt supplementation and that increased salt taste stimulation is probably required for this to occur.

Adaptation, Physiological↗
PubMed1984

Diagnosis of pheochromocytoma.

This article reviews the pathophysiology and clinical features of pheochromocytoma, along with the biochemical approaches that have been used for confirming its diagnosis. Different methods for urinary, plasma, and platelet catecholamines and catecholamine catabolites are discussed, and the authors' opinions on which test(s) to use and which patients screen are presented.

Adrenal Gland Neoplasms↗
PubMed1983

Modification of salt taste.

Salt appetite and sodium intake in humans are controlled in part by taste. A distinction can be drawn between salt appetite that occurs when the organism is sodium deficient (in need) and when the organism has sufficient sodium stores (non-need) but continues to ingest salt. Although the latter case is most relevant to human sodium consumption, little is known about its physiologic, developmental, and experiential bases. Recent studies show that changes in dietary sodium consumption are followed by taste changes. Moderate decreases in dietary sodium of 2 months or more are followed by a decrease in the concentration of salt in food judged most pleasant.

Animals↗
PubMed1982

Long-term reduction in dietary sodium alters the taste of salt.

A group of young adult subjects was placed on self-maintained, low sodium diets for 5 months. Taste responses to salt in solutions, soups, and crackers were determined both during the 2 months preceding diet initiation and during a 5-month period when subjects lowered their sodium intake. Taste responses were also determined in a control group with ad libitum salt consumption throughout the same period. Perceived intensity of salt in crackers increased. The salt concentrations of maximum pleasantness in soup and crackers fell in the experimental subjects but not in the control subjects. These results demonstrate that the preferred level of salt in food is dependent on the level of salt consumed and that this preferred level can be lowered after a reduction in sodium intake. The implications of these findings for the maintenance of low sodium diets are discussed.

Adult↗
PubMed1980

Adrenal medullary hyperplasia: a clinicopathologic study of four cases.

This study presents the clinicopathologic findings in four new cases of adrenal medullary hyperplasia. The patients presented with episodic hypertension frequently associated with palpitations, headache, and diaphoresis. All four had elevated urinary catecholamine levels during attacks, and were thought clinically to have a pheochromocytoma. In each case laparotomy revealed a diffusely enlarged adrenal gland without a discrete tumor. Histologic examination of the adrenals demonstrated a diffuse and nodular expansion of the medulla confirmed by morphometric study. Of the four patients, three underwent unilateral and one bilateral adrenalectomy. Two patients who underwent unilateral adrenalectomy have been free of symptoms for three years. Thus, it would appear that adrenal medullary hyperplasia may occur unilaterally or asynchronously in the two glands. The bilaterally adrenalectomized patient has had persistent attacks, suggesting that the stimulus to adrenal medullary hyperplasia may possible affect other chromaffin tissues. On the basis of our cases and a review of the literature, we propose the following criteria for the diagnosis of adrenal medullary hyperplasia: a clinical history of episodic attacks suggesting pheochromocytoma (generally with associated increased urinary catecholamine levels), an adrenal gland showing diffuse expansion of the medulla into the alae or tail of the gland with or without nodule formation, a medulla composed of enlarged cells with or without pleomorphism, and, most important, an increased medulla/cortex ratio, together with an increased calculated medullary weight as determined by morphometric analysis.

Adrenal Cortex↗
PubMed1979

Abrupt discontinuation of clonidine therapy.

Clonidine therapy was discontinued abruptly in seven patients. Blood pressure was recorded every hour or two hours throughout the study. Clonidine therapy was reinstituted 48 hours after its discontinuation in all except two patients, in whom it was reinstituted at 36 hours. During the withdrawal phase, blood pressure tended to return rapidly to nontreatment levels, but there was no "overshoot" in blood pressure. Apprehension, insomnia, palpitations, and sweating were experienced by two patients. These symptoms were relieved promptly by reinstituting clonidine therapy. In this prospective study, no blood pressure overshoot was noted with abrupt discontinuation of clonidine.

Adult↗
PubMed1979

Pheochromocytoma--recognition and management.

Pheochromocytoma is an infrequent cause of hypertension. In spite of its rarity, pheochromocytoma has assumed notorious importance because or a wide variety of clinical features associated with this syndrome. Hypertension remains the most important clinical lead. The presence of other features, such as severe headache, perspiration, palpitations or orthostatic hypotension, makes the diagnosis of pheochromocytoma likely. The diagnosis of this condition can be made with greater certainty than that of any other form of secondary hypertension. Pharmacologic tests are no longer used for evaluation purposes. Biochemical tests are the most important aids to diagnosis, provided highly specific methods are used to determine the levels of urinary catecholamines or their metabolites. Interference by various drugs should be avoided. Most of the pheochromocytomas are found in the abdomen, predominantly in the adrenals. Successful outcome of surgery depends critically on adequate preoperative preparation of the patient with adrenergic blocking drugs and proper intraoperative care. Surgery should only be performed in an institution with experience in treating these tumors. Invasive localizing procedures could be dangerous in patients with pheochromocytoma and are best avoided. Medical therapy proves to be quite successful for those patients who are unable or unwilling to undergo surgery and for those with demonstrated malignant tumor. The postoperative course in most instances is uneventful. The physician should be aware of familial forms of pheochromocytomas and screen all the hypertensive members of the patient's family for the presence of this condition. Pheochromocytoma, with its multiple facets, presents a challenge to the clinician; however, with prompt diagnosis and proper treatment, pheochromocytoma can often be cured. The improved management of patients with this potentially lethal condition is the result of better knowledge of biochemical pharmacology, improved preoperative, surgical and postoperative care.

Adrenal Gland Neoplasms↗
PubMed1978

Failure of alpha-methyltyrosine to inhibit peripheral triiodothyronine formation.

To determine if the adrenergic nervous system, and specifically tyrosine hydroxylase, plays a role in the extrathyroidal conversion of T4 to T3, normal male volunteers were treated with T4 and subsequently with T4 and alpha-methyl-p-tyrosine (alpha-MPT), an inhibitor of tyrosine hydroxylase, for 2 weeks. The mean serum T4 and T3 concentrations increased during T4 administration and remained at the same levels during combined T4 and alpha-MPT administration. Urinary vanillylmandelic acid excretion declined significantly during alpha-MPT administration. These results do not support the hypothesis that tyrosine hydroxylase is involved in extrathyroidal T3 production.

Adult↗
PubMed1977

Phaeochromocytoma.

Factors involved in the evaluation and care of patients with phaeochromocytoma have been discussed with respect to important considerations for the consulting or practising physician. Historical, physical, biochemical and other diagnostic procedures, as well as therapeutic manoeuvres have been adequately documented so that the clinician requiring additional information in depth may seek out the pertinent literature. Utilizing this manner of approach should significantly improve the care of patients with phaeochromocytoma in the hands of physicians who have not themselves had extensive experience with this disease. However, it must be emphasized that because of the potential gravity of this condition, if the physician feels insecure in the care of a patient or has further questions, he should not hesitate to seek expert advice which will benefit both the patient and himself.

Adrenergic alpha-Antagonists↗
PubMed1975

Vagally mediated suppression of premature ventricular contractions in man.

Twelve patients with PVC's were studied to assess the possible role of the vagus nerves in suppressing PVC's. All were without significant heart disease and under forty years of age. A series of five autonomically active drugs, including vagotonic and vagolytic agents, was administered intravenously, each drug being given after the effects of the previous one had abated. Two of the patients did not have PVC's at the time of study. Of the remaining ten patients, five showed vagally mediated suppression of PVC's. Phenylephrine (40 to 60 mug per minute) reduced HR, from an average of 63.2 bpm to 48.5 bpm by a vagally mediated reflex, and decreased PVC incidence in all five patients. The per cent of ventricular heart beats which were PVC's (per cent PVC) decreased from an average of 18.2 per cent to 3.2 per cent in these patients (p smaller than 0.005 in each case). Edrophonium (10 mg.) produced less bradycardia and less reliable PVC suppression. In two of these five patients, atropine (1.5 mg.) increased PVC incidence markedly, although the per cent PVC did not change significantly because of the concomitant tachycardia. These data suggest that strongly increased vagal tone can suppress PVC's in a significant percentage of such patients. This finding in man extends previous animal work which has shown a protective role of the vagus against ventricular arrhythmias under certain conditions.

Adult↗