Search PubMed⌕ Search

Biomedical subjects

E Grossman

Publications and source records attributed to E Grossman.

At least 127 records · Page 7Linked to original sources
PubMed1993

Hemodynamic and neurohumoral effects of fish oil in hypertensive patients.

Recent studies showed that supplementation of a large dose of fish oil is effective in lowering blood pressure. Whether supplementation of a low dose of fish oil is also effective in lowering blood pressure is controversial. The present study evaluates the hemodynamic and humoral effects of low-dose dietary fish oil supplementation in patients with mild hypertension. Eleven patients with mild hypertension were given 3 g/day of n-3 polyunsaturated fatty acids for 6 week. Twenty-four hour blood pressure monitoring and humoral parameters were recorded before and during fish oil treatment. In five patients, blood pressure response to angiotensin II (AII) infusion (1, 2, 3, 6, 9 ng/kg/min) was also recorded before and during treatment. Casual mean arterial pressure was unchanged (111 +/- 1 mm Hg v 109 +/- 3 mm Hg; P = NS). Average 24-h mean arterial pressure (MAP) also did not change during fish oil treatment (98 +/- 2 mm Hg v 99 +/- 3 mm Hg; P = NS). Fish oil supplementation did not attenuate the vascular reactivity to AII infusion. Maximal MAP following AII infusion (9 ng/kg/min) was 128 +/- 5 mm Hg before and 129 +/- 7 mm Hg during fish oil treatment (P = NS). Plasma levels of norepinephrine, renin activity, aldosterone, and atrial natriuretic peptide remained unchanged during treatment. Plasma levels of total cholesterol slightly increased from 200 +/- 10 mg/dL to 211 +/- 9 mg/dL (P < .05), but plasma levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides were unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Oral yohimbine increases blood pressure and sympathetic nervous outflow in hypertensive patients.

Yohimbine is an alpha 2-adrenoceptor antagonist that is FDA approved for treatment of impotence. The drug is an indolalkylamine alkaloid chemically similar to reserpine and is believed to act through sympatholysis. We examined effects of oral yohimbine on blood pressure (BP) and plasma levels of catechols in patients with essential hypertension, a condition in which most drug treatments can produce impotence. In 25 unmedicated hypertensive subjects, vital signs were measured and blood samples were obtained through an indwelling antecubital venous catheter at baseline and 1 and 2 h after subjects ingested 4 5.4-mg tablets of yohimbine. Mean blood pressure (MBP) increased by an average of 5 mm Hg (p < 0.01), plasma norepinephrine (NE) levels increased by 66% (p < 0.001), and plasma dihydroxyphenylglycol (DHPG) levels increased by 25% (p < 0.01) at 1 h after drug administration. The magnitude of the pressor response was unrelated to baseline MBP but positively correlated with the baseline NE level (r = 0.61, p < 0.01) and with the yohimbine-induced increment in plasma NE (r = 0.4, p < 0.01). The results indicate that yohimbine does not inhibit and actually stimulates sympathetically mediated NE release in humans and that the increased NE release produces a pressor response. Yohimbine should be administered with caution to patients with high BP, especially in individuals with evidence for increased basal sympathetic outflow or those undergoing concurrent treatment with tricyclic antidepressants or other drugs that interfere with neuronal uptake or metabolism of NE.

Administration, Oral↗
PubMed1993

[Citric acid as an adjunct to periodontal surgery].

This review focuses on the effect of acid demineralisation of the root surface as an adjunct to periodontal surgery in order to obtain new attachment. Several animal studies have shown that the treatment facilitates attachment of connective tissue to the root surface. Clinical studies, however, have failed to demonstrate the effectiveness of citric acid as an adjuvant to surgical debridement.

Animals↗
PubMed1993

Effect of urbanisation on blood pressure in Ethiopian immigrants.

Blood pressure, heart rate, height and weight were measured in a group of Ethiopian immigrants who arrived in Israel in 1991 after waiting some 6 months in Addis Ababa. The findings were compared with a previous group of Ethiopians who immigrated immediately after physical hardships and malnutrition. The recent arrivals had higher BP levels and higher Quetelet indices than the earlier group. BP values of > 140 mmHg systolic or 90 mmHg diastolic were found in 15 of 102 newcomers (14.7%) in 1991, in contrast to < 1% in the earlier group. Our findings demonstrate an important effect of urbanisation in the same environment on rise in BP, probably through changes in lifestyle.

Adolescent↗
PubMed1993

Development and verification of the proximal/marginal plaque index.

The purpose of this study was to compare the ability of experienced and newly trained investigators to use the published Global Plaque Index and a newly developed Proximal/Marginal Index (PMI) that focuses on disclosed plaque at clearly defined proximal and marginal surfaces. Four independent clinical studies were performed, two with each index, on 11 subjects per study. In each study, examinations were conducted before and after brushing, to determine inter- and intra-examiner comparisons over a range of plaque levels. Inter-examiner reliability estimates for the PMI were at a level below Global Plaque index means. Intra-examiner agreement values were similar for both indices. Both scoring systems are considered sufficiently validated to detect product differences in clinical studies.

Clinical Competence↗
PubMed1993

Clinical plaque removal efficacy of three toothbrushes.

A single-blind, randomized clinical study compared plaque removal efficacy of three toothbrush designs under conditions simulating normal use. Ninety (90) subjects with substantially complete dentition used one of the three toothbrushes: Advanced Design Reach, Crest Complete and Oral-B 40. Subjects were examined for plaque before and after a single brushing using the Global Plaque Index to estimate plaque on the entire tooth surface, and the Proximal/Marginal Plaque Index (PMI), a new index, was used to estimate plaque at proximal and marginal surfaces of the teeth. The Advanced Design Reach toothbrush reduced plaque scores significantly more than did the other toothbrushes tested (p < 0.05) using either scoring method. At marginal and proximal sites, combined or separate, Advanced Design Reach toothbrush was significantly more effective than the other toothbrushes in plaque removal and produced significantly more plaque free sites than the other two toothbrushes. Evaluation of all anterior and posterior parts of the dentition with the Global Plaque Index indicated that Advanced Design Reach was superior in removing plaque in these regions. Both plaque indices were highly correlated (correlation coefficient 0.91) indicating excellent consistency by the dental examiner.

Adolescent↗
PubMed1993

Plaque removal efficacy of two children's toothbrushes: a one-month study.

Reach Wonder Grip toothbrush for children was evaluated for plaque removal efficacy and compared to the Colgate Plus Junior (extra soft). The subjects appeared at the test site with overnight (14-18 hours) plaque accumulation. After qualifying for the study, sixty-eight (68) subjects were randomly assigned one of the test brushes. They then participated in the test evaluation at the clinical site wherein plaque levels were measured before and after a one minute brushing. Plaque removal efficacy was evaluated by the Global Plaque Index (percent of tooth surface covered by stained deposit). The subjects then used the assigned toothbrush at home for one month and returned to the test site to repeat the baseline evaluations. After their final plaque evaluations, the subjects were given a new toothbrush from each brand to use at home for one week and the subject and the parent were asked to complete a preference questionnaire. Sixty-seven (67) subjects completed the one month study. After one month's use of twice per day brushing, neither of the test toothbrushes demonstrated any evidence of oral irritation that could be related to toothbrushing. The results indicated that Reach Wonder Grip for Children was significantly more effective (p < 0.05) than Colgate Plus Junior in removing overall (Global) plaque at the initial exam period. The preference questionnaire indicated that the Reach Wonder Grip toothbrush was preferred by both the children and their parents. It is concluded that the new Reach Wonder Grip toothbrush for children is safe and effective for plaque removal.

Child↗
PubMed1992

Role of glucose carrier in human erythrocyte water permeability.

Although the transport properties of human erythrocyte water channels have been well characterized, the identity of the protein(s) mediating water flow remains unclear. Recent evidence that glucose carriers can conduct water raised the possibility that the glucose carrier, which is abundant in human erythrocytes, is the water channel. To test this possibility, water permeabilities and glucose fluxes were measured in large unilamellar vesicles (LUV) containing human erythrocyte lipid alone (lipid LUV), reconstituted purified human erythrocyte glucose carrier (Glut1 LUV), or reconstituted glucose carrier in the presence of other human erythrocyte ghost proteins (ghost LUV). In glucose and ghost LUV, glucose carriers were present at 25% of the density of native erythrocytes, were oriented randomly in the bilayer, and exhibited characteristic inhibition of glucose flux when exposed to cytochalasin B. Osmotic water permeability (Pf, in centimeters per second; n = 4) averaged 0.0012 +/- 0.00033 in lipid LUV, 0.0032 +/- 0.0015 in Glut1 LUV, and 0.006 +/- 0.0014 in ghost LUV. Activation energies of water flow for the three preparations ranged between 10 and 13 kcal/mol; p-(chloromercuri)benzenesulfonate (pCMBS), an organic mercurial inhibitor of erythrocyte water channels, and cytochalasin B did not alter Pf. These results indicate that reconstitution of glucose carriers at high density increases water permeability but does not result in water channel activity. However, because the turnover number of reconstituted carriers is reduced from that of native carriers, experiments were also performed on erythrocyte ghosts with intact water channel function. In ghosts, Pf averaged 0.038 +/- 0.013 (n = 9), while the activation energy for water flow averaged 3.0 +/- 0.3 kcal/mol.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

Sympathoadrenal contribution to plasma dopa (3,4-dihydroxyphenylalanine) in rats.

1. To determine the sources of dopa (3,4-dihydroxyphenylalanine) in plasma, we measured regional arteriovenous differences, tissue concentrations and urinary excretion of dopa during systemic intravenous infusions of I-[3H]dopa into anaesthetized intact rats and rats pretreated with the sympathetic neurotoxin, 6-hydroxydopamine. 2. In intact rats, large arteriovenous increments in plasma dopa concentrations were noted in the femoral (47%) and adrenal (141%) beds, with a small arterial-portal venous increment (11%), whereas in the kidney there was a substantial (47%) arteriovenous decrement in plasma dopa levels. Skeletal muscle appeared to be a major source of dopa in arterial plasma. 3. Treatment with 6-hydroxydopamine abolished the afferent-efferent increment of plasma dopa concentrations in the femoral bed. The arteriovenous decrement of plasma dopa concentrations in the kidney was preserved, and the arteriovenous increment in the adrenal bed was decreased by about half. Arterial plasma dopa levels fell by 41%. 4. Regional extraction percentages of I-[3H]dopa were used to estimate the clearances and rates of appearance (spillovers) of dopa in plasma. Dopa spillover was detected in the femoral, renal, splanchnic and adrenal beds, with skeletal muscle accounting for about 44% and the kidneys accounting for about 18% of dopa in arterial plasma. Whereas chemical sympathectomy decreased the femoral and renal spillover of dopa by 90% or more, arterial dopa levels and estimated dopa spillover into arterial plasma were decreased by only about 45%. 5. The kidneys accounted for 22% of dopa clearance from arterial plasma. From the renal extraction of I-[3H]dopa and the urinary excretion of [3H]dopamine, it was estimated that 77% of dopa removed in the kidneys was excreted as dopamine in intact animals and 69% was excreted as dopamine in sympathectomized animals. Conversely, about 80% of urinary endogenous dopamine was derived from plasma dopa, regardless of 6-hydroxydopamine treatment. 6. The results indicate that endogenous dopa in arterial plasma is derived substantially but not exclusively from sympathetic nerve endings that are destroyed by 6-hydroxydopamine, especially in skeletal muscle and the kidneys. Regional dopa spillover therefore probably reflects regional catecholamine biosynthesis. In rats, urinary dopamine is derived mainly from renal decarboxylation of circulating dopa.

Adrenal Glands↗
PubMed1992

Effect of ionizing radiation on sympathetic nerve function in rat parotid glands.

Ionizing radiation (IR) irreversibly damages salivary glands. The pathologic mechanism is unknown. Previously we reported that parotid serous acinar cells may not be the primary site of damage by IR. The purpose of this study was to determine if IR alters sympathetic nerve function in rat parotid glands. Male adult rats received a single dose of radiation (20 Gy) to the head and neck. Three days after IR, parotid saliva secretion induced by norepinephrine (NE) was completely blocked. Catecholamine uptake and metabolism were studied by injecting [3H] dopamine ([3H]DA) into irradiated rats, as a bolus. After 60 min, animals were sacrificed and the parotid gland, submandibular gland, and left ventricle removed. Tissue contents of [3H]DA and [3H]NE, identified by HPLC, were unaffected by IR. The results indicate that IR abolishes acinar responsiveness to NE without affecting parotid sympathetic nerve function.

Animals↗
PubMed1992

Effects of water immersion on sympathoadrenal and dopa-dopamine systems in humans.

Water immersion to the neck increases central blood volume and evokes a marked diuresis and natriuresis. The present study examined simultaneously effects of water immersion on activities of three endogenous systems thought to participate in sodium homeostasis: the sympathetic nervous system, the atrial natriuretic peptide system, and the renal dopa-dopamine system. Hourly urine collections and antecubital venous blood samples were obtained from 10 normal subjects before, during, and after sitting in a water-immersion tank for 3 h; four control subjects were studied while seated without immersion. Urine volume was increased by more than threefold after 1 h of immersion (from 1.2 +/- 0.2 ml/min at baseline to 5.9 +/- 0.7 ml/min, P less than 0.001) and peaked during the second hour. Urinary sodium excretion increased by more than twofold (from 103 +/- 17 mu eq/min at baseline to 196 +/- 36 mu eq/min at 1 h, P less than 0.001) and peaked during the third hour. Plasma levels and urinary excretion of norepinephrine (NE) and epinephrine were suppressed consistently during immersion (P less than 0.05). There was a marked, prompt, and sustained increase in plasma levels of immunoreactive atrial natriuretic factor (irANF) from 6.9 +/- 1.9 pg/ml baseline to 17.3 +/- 4.3 pg/ml at 1 h (P less than 0.001). Urinary excretion of dopa, dopamine, and 3,4-dihydroxyphenylglycol, a neuronal metabolite of NE, changed in a triphasic pattern, with decreased excretion during the first hour of immersion (P less than 0.01), small but consistent increases during the next 2 h, and decreased excretion, to below baseline, during recovery (P less than 0.01 for dopa and dopamine).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1992

End-organ disease in hypertension: what have we learned?

The major target organs that suffer from sustained hypertension are the heart, kidneys, and brain. Cardiac adaptation to arterial hypertension consists of left ventricular hypertrophy (LVH) of the concentric type, that is, an increase in wall thickness at the expense of chamber volume. However, LVH can no longer be considered a simple adaptive myocardial process serving to compensate for the increase in afterload and bring left ventricular wall stress back to normal. Data from the Framingham cohort have shown that the occurrence of LVH drastically increases the risk of sudden death and other cardiovascular morbidity and mortality irrespective of the levels of arterial pressure. Renal adaptation to arterial hypertension consists of a decrease in renal blood flow with elevations in filtration fraction and renal vascular resistance. With progressive hypertensive cardiovascular disease, glomerular filtration rate will fall as well. Recent data in patients with mild-to-moderate hypertension demonstrate that despite "efficacious" antihypertensive therapy, one-third to one-half of hypertensive patients may experience a significant decline in renal function. Cerebrovascular adaptation to hypertension consists of micro- and macrovascular disease leading to vascular dementia, or ischemic or hemorrhagic stroke. Cerebrovascular autoregulation, the mechanism by which cerebral blood flow is maintained, despite changes in arterial pressure, may be altered in hypertension.

Humans↗
PubMed1992

Carbamazepine neurotoxic reaction after administration of diltiazem.

A patient with epilepsy controlled by carbamazepine developed a carbamazepine neurotoxic reaction after being given an increased dosage of diltiazem hydrochloride as adjunctive therapy. Abrupt withdrawal of diltiazem reduced the circulating carbamazepine concentration and resulted in an epileptic attack. Awareness of the interaction between diltiazem and carbamazepine and careful monitoring of carbamazepine blood levels is recommended to prevent the dangerous neurotoxic effect associated with this combination.

Carbamazepine↗
PubMed1992

Left ventricular mass in diabetes-hypertension.

BACKGROUND: This study was undertaken to identify whether diabetes mellitus (DM) accelerates the development of left ventricular hypertrophy (LVH) in hypertensive patients. METHODS: Cardiac structure, systolic function, and hemodynamics were evaluated by two-dimensional M-mode echocardiography in diabetic and nondiabetic patients with essential hypertension. RESULTS: Patients with hypertension with and without DM had the same end-systolic and end-diastolic dimensions, cardiac output, total peripheral resistance, and ejection fraction. Diabetic hypertensive patients had greater interventricular septum (1.32 +/- 0.20 vs 1.07 +/- 0.20 cm) and posterior wall (1.20 +/- 0.20 vs 1.00 +/- 0.10 cm) thickness than did nondiabetic hypertensive patients. Consequently, left ventricular mass index was greater in patients with hypertension and DM than in those without DM (158 +/- 45 vs 113 +/- 20 g/m2). With the use of Devereux criteria for recognition of LVH (left ventricular mass index above 134 g/m2 in men and above 110 g/m2 in women), 72% of the diabetic patients had LVH, whereas only 32% of the nondiabetic patients had LVH. Left ventricular contractility, as reflected by the ratio of end-systolic wall stress to end-systolic volume index, was decreased in diabetic compared with nondiabetic hypertensive patients. CONCLUSIONS: The data suggest that DM accelerates the development of LVH in patients with essential hypertension independent of arterial pressure and, therefore, may contribute to the increased cardiovascular morbidity and mortality in patients with hypertension.

Analysis of Variance↗
PubMed1991

Method for measuring endogenous 3-O-methyldopa in urine and plasma.

The present report describes a method using column liquid chromatography with electrochemical detection for assaying concentrations of 3-O-methyldopa in urine and plasma. The technique combines a one-step sample preparation scheme with post-column flow-through electrodes in series, allowing adequate chromatographic separation of 3-O-methyldopa from other endogenous substances in urine. The validity of the method was confirmed by markedly decreased urinary 3-O-methyldopa levels after administration of an inhibitor of catechol-O-methyltransferase to rats, radioactivity in chromatographic fractions corresponding to 3-O-methyldopa in urine of rats undergoing infusion of [3H]-L-DOPA, and correlations between excretion rates of 3-O-methyldopa and catechols in humans. In healthy humans, urinary excretion of 3-O-methyldopa averaged 974 +/- 707 (S.D.) nmol per day, and plasma levels of 3-O-methyldopa averaged 89 +/- 32 nmol/l. The method should be useful in studies about the metabolism of endogenous and exogenous DOPA.

Animals↗
PubMed1991

Left ventricular filling in the systemic hypertension of obesity.

Cardiac structure and systolic as well as diastolic functions were evaluated by 2-dimensional M-mode echocardiography in lean and obese patients who were either hypertensive or normotensive. Diastolic function, as assessed by diminished normalized early peak filling rate and prolonged duration of rapid filling, was decreased in hypertensive patients compared with normotensive patients (p = 0.02). When compared with lean patients with similar blood pressure levels, obese patients exhibited a lower normalized peak filling rate (p = 0.0014) but no difference in duration of rapid filling. A significant correlation was observed between the normalized peak filling rate and either body mass index or left ventricular (LV) mass (r = 0.355 and r = -0.32, respectively; p less than 0.001). Obese patients had greater LV end-diastolic and systolic dimensions (p less than 0.005 and p less than 0.02, respectively), LV wall thickness (p less than 0.05) and LV mass (p less than 0.007) than lean patients. Impairment of LV filling was most pronounced in obese hypertensive patients. It is concluded that the burden on the left ventricle imposed by obesity causes cardiac enlargement and impairment of LV filling regardless of levels of arterial pressure.

Adult↗
PubMed1991

Cardiovascular effects of isradipine in essential hypertension.

The immediate and short-term cardiovascular effects of oral isradipine therapy were evaluated in 11 patients with mild to moderate systemic hypertension. Isradipine, 5 mg administered orally, induced a significant reduction in arterial pressure from 165 +/- 6/88 +/- 3 mm Hg to 140 +/- 5/76 +/- 2 mm Hg (p less than 0.001) within 2.5 hours by a decrease in total peripheral resistance associated with an increase in heart rate and cardiac output. Contrary to the acute effect, oral therapy with isradipine for 3 months reduced arterial pressure through a decrease in total peripheral resistance but without causing an increase in heart rate or cardiac output or activation of the sympathetic nervous system. Isradipine slightly reduced left ventricular mass and improved cardiac systolic function and left ventricular filling. Renal blood flow increased, and renal vascular resistance (p less than 0.01) and total blood volume (p less than 0.002) decreased without a change in either sodium excretion or body weight. Thus, isradipine, when given for 3 months, decreased arterial pressure by reducing total peripheral resistance without activation of reflexive mechanisms. Its favorable effects on systemic hemodynamics, total blood volume, renal blood flow, and cardiac structure and function suggest isradipine to be an excellent choice for antihypertensive therapy.

Adult↗