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Biomedical subjects

H N Neufeld

Publications and source records attributed to H N Neufeld.

At least 19 recordsLinked to original sources

Effects of uncomplicated acute myocardial infarction on biochemical parameters of stress and sexual function.

The blood levels of several "stress indicators" (prolactin [PRL], growth hormone [hGH], total catecholamines, and adenosine 3',5'-cyclic monophosphate [cAMP]) were measured in men during the first 2 weeks of uncomplicated acute myocardial infarction (AMI) and during a 3-month follow-up period. PRL levels were significantly elevated during the first day, and hGH was elevated during the week after the AMI. The levels returned to the control baseline values thereafter. The levels of the total catecholamines and cAMP in blood remained normal throughout the study period. Sexual function during the 3-month follow-up was measured in 29 patients, using a specially designed questionnaire. Impotence was found in five patients and decreased libido in four. No correlation was noted between PRL values, the other stress indicators, and sexual dysfunction. A trend toward increased incidence of sexual dysfunction was found among patients with recurrent AMI.

Adult

[Suspected acute coronary events in emergency room patients].

Identification of patients in whom chest pain is due to an acute coronary event is among the most challenging problems in emergency medicine. Because of the dangers of missing the diagnosis in patients with a possibly fatal condition, emergency room (ER) physicians often admit patients for 'observation' or 'to rule out MI.' As a result of such a policy, only 30-50% of such patients admitted to the CCU may finally be diagnosed as having an acute myocardial infarction (AMI), resulting in deleterious medical, psychological and economic consequences for the others. A series of 2280 patients who were referred to the ER was followed for 2 weeks. 1362 (59.7%) of those admitted were discharged; 16.1% were hospitalized in the CCU and 83.9% in medical wards. 95 (64.6%) of those hospitalized in the CCU and 97 (12.7%) of those admitted to medical wards had an AMI. The proportion of cases in which hospitalization was unnecessary was 10.2% in the CCU and 29.8% in the medical wards. Unjustified discharges from the ER were 4.3% of referrals. These data are similar to those reported from the USA and from our first study in 1969. It is hoped that by using a triage algorithm in the ER, differentiation between chest pain due to coronary heart disease and that due to other causes will be more accurate and therefore the demand on scarce resources due to unnecessary admissions will be substantially reduced.

Acute Disease

Carbon dioxide laser effect on platelet function and surface ultrastructure in vitro.

Platelet aggregation may be an important factor in the feasibility of transcatheter laser angioplasty. The in vitro effects of increasing doses of CO2 laser irradiation on platelet number, function, and surface ultrastructure were examined. Results indicated a progressive dose-response reduction of both platelet number and function following laser irradiation. By scanning electron microscopy the irradiated platelets showed dose-related changes in pseudopods as well as progressive damage of the cell membrane.

Adult

Haemodynamic effects of intravenous isosorbide-5-mononitrate in acute and chronic left heart failure of ischaemic aetiology.

Isosorbide-5-mononitrate was administered in a continuous intravenous infusion, according to the haemodynamic response, to 19 patients with left heart failure of ischaemic aetiology; 12 with acute heart failure complicating an acute myocardial infarction and 7 with chronic ischaemic failure. In both groups, the following statistically significant haemodynamic changes were observed: a decrease in PCWP from 25.4 +/- 4.6 to 17.2 +/- 4.6 mmHg; an increase in SWI from 19.1 +/- 10 to 23.6 +/- 13.1 gm m-2; a slight increase in cardiac index with no change in arterial pressure and only minimal decrease in vascular resistance. There were two major differences in the haemodynamic response between the patients with acute heart failure and those with chronic disease: (a) the duration of the effect of isosorbide-5-mononitrate on the PCWP was longer in the first group (mean, 8 hours, compared to 1.5 hours in the chronic group), and (b) the effect on afterload was more pronounced in the group with chronic ischaemic failure than in the first group. Thus, isosorbide-5-mononitrate administered by intravenous infusion under careful monitoring appears to have a beneficial role in the treatment of acute as well as chronic ischaemic heart failure.

Aged

Hour-glass deformity of the pulmonary valve: a third type of pulmonary valve stenosis.

In the 12 years from 1975 to 1987, 55 patients had open pulmonary valve surgery for isolated congenital stenosis of the pulmonary valve. Three types of pulmonary stenosis were seen: (a) dome-shaped pulmonary stenosis (34 patients); (b) dysplastic pulmonary valves with thick cauliflower-like cusps (12 patients), and (c) hour-glass deformity of the pulmonary valve, with "bottle-shaped" sinuses (nine patients). This third type has not been described before. Preoperative identification of the valve structure is important because the choice of treatment (balloon dilatation for some dome-shaped valves and excision for dysplastic and hour-glass valves) depends on the type of stenosis.

Adolescent

Hemodynamics, circulating catecholamines and response to intravenous nitrate therapy in a specific subset of acute myocardial infarction: the hypertensive-hyperkinetic-coronary-active group.

A specific subset of acute myocardial infarction was defined and named 'the hypertensive-hyperkinetic-coronary-active' subgroup. This subgroup included patients with acute myocardial infarction without pump failure or hypovolemia who continued to have hypertension and tachycardia, after relief of pain and who also had at least two recurrent ischemic episodes in the first days after a transmural event. Fifteen patients belonging to this group (group A) were studied in comparison with 15 other patients with acute myocardial infarction complicated by pump failure (group B). The alterations in hemodynamics, in circulating catecholamine levels and the clinical course during an intravenous infusion of isosorbide dinitrate were evaluated and the data obtained in the two groups were compared. The patients in group A had tachycardia, hypertension and upper normal filling pressures (pulmonary capillary wedge pressures: 15.8 +/- 1.8 mm Hg). They had high levels of circulating catecholamines (1,343 +/- 407 ng/l), a cardiac output of 5.9 +/- 0.6 liters/min and stroke work index of 78 +/- 11 (mean +/- SD). The effect of intravenous nitrates on the left ventricular function curves of the two groups was the following: a marked shift downward and slight shift to the left in group A, as opposed to a moderate but significant shift upward and marked shift to the left in group B. The episodes of recurrent ischemia subsided in 13 out of 15 patients from group A. It appears therefore that the hyperkinetic patients with acute infarction are characterized by a hypersympathetic response, a typical hemodynamic profile and a particular response to nitrate therapy directionally opposite to the changes obtained in patients with acute infarction complicated with failure.

Aged

Hemodynamic effects of oral isosorbide-5-mononitrate and dinitrate in ischemic heart failure.

Isosorbide-5-mononitrate (ISMN), the main metabolite of isosorbide dinitrate (ISDN) was recently introduced in clinical use. The hemodynamic effects of oral ISMN and ISDN, administered in equal doses, were studied in a randomized, crossover fashion in 20 patients with pump failure of ischemic etiology. Baseline hemodynamic criteria for admission into the study were: pulmonary capillary wedge pressure (PCW) of at least 20 mmHg and systolic arterial pressure (AP) above 90 mmHg. Hemodynamic parameters were serially measured and systemic vascular resistance was calculated up to 6 h postadministration of either ISMN or ISDN single dose (40 mg). Maximal effects obtained were statistically significantly different from baseline. While ISMN and ISDN appeared to be equipotent in reducing the filling pressure, with a maximum effect reached in 60-120 min, the mononitrate maintained its effects for a longer period.

Administration, Oral

Calcium antagonists--adverse drug interactions.

In the clinical management of heart disease, calcium channel blockers are generally prescribed in combination with one or more anti-angina, antiarrhythmic, or antihypertensive agents. Two different mechanisms are involved in drug interactions: pharmacokinetic and pharmacodynamic. In the former, the disposition of one drug is altered by the action of another, causing an increase or decrease in its absorption or its modified distribution, metabolism, or excretion. In pharmacodynamic interactions, the physiologic effects of one drug interfere either directly or indirectly with those of another, for instance, by alterations in fluid or electrolyte balance. This effect may be antagonistic or additive. The present work outlines the possible adverse interactions between the three main calcium antagonists and other therapeutic agents, including digoxin, beta blockers and antiarrhythmic, anesthetic, antihypertensive, antiasthmatic, and antidiabetic drugs and contrast media. Knowledge of these effects is of major clinical importance in the treatment of cardiac patients.

Adrenergic beta-Antagonists

Distributions of total cholesterol, triglycerides, and high-density lipoprotein cholesterol in Israeli Jewish children of different geographic-ethnic origins, ages 9-17 years.

To determine age and ethnic patterns of blood lipid levels in childhood and adolescence and to extend previous adult and late adolescent Israeli data to prepubertal ages, the levels of plasma total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) were determined among 1,153 schoolchildren in the area of Petah-Tikva. Half of the children were born to immigrants from Yemen. Among boys, TC levels progressively decreased as age increased from 10-11 to 14-15 years (159 to 142 mg/dl). The age-specific TC and HDL-C means among boys are compatible with an initial swift fall with age, followed by a rise restricted to TC during puberty. Among girls, progressively lower means through ages 12-13 and increasingly higher ones for older age groups are also compatible with puberty-determined changes, previously observed in American cohorts. The differences in TC were only partly accounted for by lower HDL-C means at higher ages (52 mg/dl in the youngest and 45 mg/dl in the oldest age group, respectively, among boys, compared with 53 mg/dl for girls at both ages 9 and 16-17). TG levels in boys, but not in girls, showed age differences paralleling those found for HDL-C, but in an inverse direction. TC means were lower as age increased only among female offspring of European-born Jews (159 to 148 mg/dl, ages 9-12 compared with ages 13-17), a phenomenon that requires further study. Overall, TC and HDL-C were clearly higher among girls than boys beginning at ages 12-13, with little or no sex differences in TG. The sex differences in TC, contrary to previous studies, were not fully accounted for by HDL-C sex differences. The ethnic variability paralleled previous findings in Israeli adults and adolescents, showing low TC levels among male offspring of Yemenite and other Asian-born fathers. The ethnic differences among girls were small. No specific pattern of age-related lipid changes was found in the group of Yemenite origin, who represented offspring of parents with notoriously low levels of coronary heart disease incidence.

Adolescent

Enhanced risk of coronary heart disease mortality in lean hypertensive men.

A recently presented hypothesis contends that the excess coronary heart disease mortality associated with hypertension is more prominent in lean men than in overweight men. This hypothesis was addressed using data collected in the Israeli Ischemic Heart Disease Study (n = 10,059). The ratios of age-adjusted 15-year death rates in hypertensive and normotensive men were 4.7, 2.8, 2.0, and 1.9 in the Quetelet index groups of less than 2.29, 2.29 to 2.56, 2.56 to 2.83 and greater than 2.83 g/cm2, respectively. The corresponding ratios for all-cause mortality were 2.2, 2.1, 2.0, and 1.7, respectively. The group with the highest all-cause age-adjusted mortality, at 33.6%, was that of the leanest (less than 2.29 g/cm2, bottom 20% of the Quetelet index distribution) hypertensive subjects. The same group also displayed the highest coronary heart disease mortality (age-adjusted rate, 18.2%). The findings persisted for both smokers and nonsmokers and after exclusion of men with coronary heart disease or diabetics at intake, men on antihypertensive medication, or those who died in the first 2 years of follow-up (1963-1965). A multivariate risk score for developing myocardial infarction was calculated, based on levels of age, systolic blood pressure, total cholesterol, high density lipoprotein cholesterol, cigarette smoking, diabetes mellitus, and Quetelet index. This score varied little across the four Quetelet index groups in hypertensive men: 5-year mean estimated risks of myocardial infarction were between 70 and 74/1000. In normotensive men the scores increased from 19/1000 in the leanest subjects to 29/1000 in the overweight ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Alpha-tocopherol: effect on plasma lipoproteins in hypercholesterolemic patients.

This study was designed to examine the hypothesis that dl-alpha-tocopheryl acetate (vitamin E) increases the level of high-density lipoprotein cholesterol (HDLC) with a concomitant decrease of the ratio of total cholesterol/HDLC and a resultant amelioration of the coronary risk profile. Vitamin E (500 IU/day) or placebo were administered under double-blind randomized allocation to 69 hypercholesterolemic patients for 3 months. Sixty patients completed the study (30 in the active treatment group and 30 in the placebo group). Vitamin E raised the mean level of HDLC from 1.39 +/- 0.38 (SD) to 1.58 +/- 0.41 mmol, a 13.6% increase. This increase significantly (P less than 0.05) exceeded a parallel smaller increase of only 0.05 mmol (3.8%) in the placebo group. As total cholesterol (TC) declined by similar proportions in the vitamin E (7.8%) and placebo (9.4%) groups, a concomitant reduction of 23% in the TC/HDLC ratio was achieved in the vitamin E group, significantly exceeding a 9.1% reduction under placebo. Significant beneficial effects were noted on apolipoprotein (Apo) A (which rose) and Apo B (which declined). An increase of Apo A/Apo B ratio by 17.9% was observed only in the vitamin E group. These results suggest that the oral administration of vitamin E (500 IU/day) is beneficial in hyperlipoproteinemia and offers a potential tool for treating the increased coronary heart disease risk.

Apolipoproteins A

The effects of varying lengths and powers of CO2 laser pulses transmitted through an optical fiber on atherosclerotic plaques.

We have studied the changes induced in atherosclerotic arteries by a CO2 laser beam delivered through a silver halide optical fiber. We found that the crater depth and diameter correlate with the total energy delivered and with the mode of delivery. Short-duration high-power pulses caused shallower and narrower craters and less damage to the arterial wall compared to the same energy delivered as low-power pulses of long duration. Thus, high-power pulses for short periods may be an effective and safe procedure for evaporization of atherosclerotic plaques.

Arteriosclerosis

Improvement by oral metoprolol of exercise-induced ischemic dysfunction in patients with coronary heart disease.

The effect of metoprolol on global left ventricular function during exercise was analyzed with nuclear ventriculography in 17 patients with ischemic heart disease. All had stable angina pectoris and ST-segment depression of more than 0.1 mV during treadmill exercise when not taking metoprolol. Each patient was stressed with supine bicycle exercise to the same load on a maintenance dose of metoprolol (100 mg X 2/day) and on a second occasion without the drug, the two being separated by 7 days. The mean heart rate and systolic blood pressure were significantly reduced both at rest and exercise with metoprolol. There was no significant difference of rest left ventricular ejection fraction with or without metoprolol. At exercise, however, every patient showed improvement of left ventricular function, the average left ventricular ejection fraction increasing by 14% (+/- 6) relative to the same exercise without metoprolol (p less than 0.001). We conclude that chronic metoprolol treatment in patients with ischemic heart disease can ameliorate left ventricular dysfunction induced by exercise and may thereby reduce myocardial ischemia.

Administration, Oral

Severe aortic regurgitation: a rare presentation of giant cell arteritis.

A 53-year-old patient with no past history of rheumatic fever or lues presented with severe aortic regurgitation, underwent hemodynamic evaluation, and subsequently, an uneventful aortic valve replacement. The initial pathological interpretation was nonspecific aortitis. Six months following surgery arthralgia, muscular pain, difficulty in mastication, and fatigue occurred. There was no fever, however, sedimentation rate was 100/130. Cardiac examination was normal. Review of the pathological specimens revealed granulomatous arteritis with giant cells, typical of giant cell arteritis. Though the association of aortic regurgitation and giant cell arteritis is well recognized, only two such cases of severe aortic regurgitation requiring valve replacements have yet been described, of them, one probably had Takayasu's arteritis. An accurate diagnosis is of importance since steroid treatment is effective, and if introduced early, the inflammatory process may be arrested.

Aorta