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Biomedical subjects

M Levy

Publications and source records attributed to M Levy.

At least 379 records · Page 21Linked to original sources
PubMed1989

Racial differences in young children's blood pressure. Responses to dynamic exercise.

Studies have observed that black children exhibit greater blood pressure increases in response to dynamic exercise than white children. Seventy-five (51 white, 24 black) children aged 4 to 6 years old had their blood pressure and heart rate measured before, during, and 5 minutes after dynamic upright exercise on the treadmill. Girls had higher preexercise heart rate values than the boys, and showed a marginally slower recovery of diastolic blood pressure values. Black children had significantly lower preexercise and peak exercise heart rate values, higher systolic blood pressure values at peak exercise, and greater systolic blood pressure increases in response to exercise than did white children. These differences are discussed in terms of mechanisms that may be responsible for racial differences in essential hypertension.

Black People↗
PubMed1989

Hepatitis during measles in young adults: possible role of antipyretic drugs.

Fifty-six per cent of 118 young adults observed during a recent measles epidemic had some disturbance on liver function tests. Five per cent developed overt jaundice. Patients treated for fever with paracetamol were found to have significantly higher rates of transaminase impairment compared to those treated with dipyrone. Sixty-five and 58% of patients given paracetamol had elevated ALT and AST levels, respectively. Only 15% of patients given dipyrone had elevated levels of these two enzymes (p less than 0.01 for ALT and p less than 0.02 for AST). The mean levels of transaminases and bilirubin in the paracetamol-treated patients were significantly higher than those found in the dipyrone-treated patients [92 +/- 86 vs. 42 +/- 49 IU (p less than 0.02) for AST and 12 +/- 6.0 vs. 7.0 +/- 2.0 mumoles per liter (p less than 0.01) for bilirubin]. The cumulative dose of paracetamol in those who had impaired liver function was higher than that ingested by patients who did not develop liver damage, although still within the usual therapeutic range [11.6 +/- 5.8 vs. 7.6 +/- 4.2 gm (p = 0.02)]. The possible ways in which measles infection and paracetamol in combination can lead to hepatic damage are discussed.

Acetaminophen↗
PubMed1989

Study of the in vitro bioactivation of albendazole in human liver microsomes and hepatoma cell lines.

The metabolism of albendazole (ABZ), a benzimidazole anthelminthic, was studied in either microsomal preparations of human liver biopsies or cultured human hepatoma cell lines. Metabolites were analyzed by HPLC. Our data show that microsomes from human biopsies and two human cell lines, HepG2 and Hep3B, oxidize the drug to the sulfoxide very efficiently, whereas the third cell line tested, SK-HEP-1, does not. Both cytochrome P-450 dependent monooxygenases and flavin-containing monooxygenases appear to be involved in human ABZ metabolism. Using the cell line displaying the highest ABZ-metabolizing activity, HepG2, the cytotoxic and the inducing effects of the parent drug ABZ and of two primary metabolites, the sulfoxide and the sulfone were studied. These three chemicals provoked a rise in mitotic index resulting from cell division blockage at the prophase or at the metaphase (ABZ metabolites) stage, and ABZ was more cytotoxic than its metabolites. With regard to enzyme-inducing effects, our data clearly demonstrate that the sulfoxide and, to a lesser degree, the sulfone are potent inducers of some drug metabolizing enzymes (i.e., cytochrome P-488 dependent monooxygenases and UDP glucuronyltransferase), whereas ABZ fails to increase and even slightly decreases these enzymatic activities. In conclusion, the HepG2 human hepatoma cell line appears to be suitable for the study of many parameters of metabolism and action of ABZ and other structurally related compounds in humans.

Albendazole↗
PubMed1989

Effect of age on the pharmacokinetics of dipyrone.

The pharmacokinetics of the dipyrone metabolite, 4-methylaminoantipyrine (MAA) was evaluated, following the administration of a single oral dose of dipyrone 1.0 g to 12 young (21-30 years) and 9 elderly (73-90 years) healthy volunteers. Maximal concentration, time to peak and absorption rate of MAA were similar for both groups. The elimination half-life was 2.6 (0.2) h for the young and 4.5 (0.5) h for the elderly subjects. Total clearance of MAA, corrected for lean body mass (LBM), was lower in the elderly than in the young 2.65 vs 3.97 ml.min-1.kg-1 LBM. There was no differences between the groups in the apparent volume of distribution. A good correlation was found between the total body clearance of MAA and the creatinine clearance, which was also reduced in the elderly (r = 0.61).

Adult↗
PubMed1989

SESAM-DIABETE, an expert system for insulin-requiring diabetic patient education.

SESAM-DIABETE is an interactive educational expert system that provides personalized advice and therapeutic recommendations for insulin-requiring diabetic patients. Because of its sophisticated explanation facilities, this system is intended to complete the more traditional educational tools for diabetic patients. It has been developed using an original essential expert system, namely SESAM, itself implemented in an upper-layer of Lisp, MBX. Its control structure uses a top-down strategy to solve a problem; i.e., it decomposes the current problem into subproblems easier to solve, this method being recursively applied to each subproblem. All information about patients is kept in a Patient Medical Record, which allows their follow-up. This system is currently available from their home for selected patients through the French telematic network TELETEL and is under clinical evaluation.

Computer Communication Networks↗
PubMed1989

The relationship between hostility and blood pressure in children.

The relationship between two dimensions of hostility and resting blood pressure was examined in 98 children aged 7 to 10 years. The children completed the expressive and experienced hostility subscales of the Buss-Durkee Hostility Inventory and one week later had blood pressure and obesity levels assessed. Multiple regression analyses and analyses of variance showed that expressive hostility was positively associated with blood pressure, although this relationship became marginally significant when the effects of obesity were controlled. A significant inverse relationship was found between experienced hostility and systolic blood pressure. These results are discussed as they relate to findings in adults on hostility and cardiovascular disease and the relationship between hostility, blood pressure, and obesity.

Blood Pressure↗
PubMed1989

Plasma exchange and immunosuppression for rapidly progressive glomerulonephritis: prognosis and complications.

Rapidly progressive glomerulonephritis frequently leads to death or dialysis. In 21 cases treated by plasma exchange and immunosuppression we observed seven deaths, with 12 others progressing to chronic renal failure within 3 months. Patients who died were older than those who survived (57.5 +/- 17.7 vs 40.5 +/- 16.5 years, mean +/- SD, P = 0.05), but had similar clinical symptoms (hypertension, haematuria, proteinuria, extrarenal signs) and biochemical presentation (initial creatininaemia). They required the same degree of haemodialysis, of plasma exchanges and of bolus methylprednisolone. The causes of death were infection (three cases), cardiac arrhythmia (two cases) and gastrointestinal bleeding (two cases). Among the 14 remaining patients, only two recovered normal renal function. Twelve had chronic renal failure, six of them requiring chronic dialysis or transplantation. Severe renal failure at entry and anuria were more frequently observed in patients whose renal function did not improve during treatment. Plasma exchange and steroid bolus infusions also seemed to have a beneficial effect on renal function.

Adult↗
PubMed1989

Heterogeneous renal responses to atrial natriuretic factor. I. Chronic caval dogs.

Atrial natriuretic factor (ANF) (175 ng.kg-1.min-1) was administered to 14 normal, alert dogs and again after constriction of the thoracic vena cava. The average natriuresis observed in the dogs when they were normal was blunted by 55% when they developed ascites and were avidly retaining sodium. Of the 14 caval dogs, 7 showed a natriuretic response no different from the control phase while 7 showed no natriuresis at all in response to the ANF. Ten dogs were restudied when they entered a phase of sodium balance despite the persistence of ascites. All 10 dogs now responded to ANF, and 5 dogs previously not responding now showed a mean change of urinary sodium excretion rate (delta UnaV) of 204 mu eq/min. The two groups could not be differentiated in terms of plasma volume, systemic or renal hemodynamics, or plasma levels of renin and aldosterone. We conclude that there is reversible attenuation of the ANF natriuretic effect in 50% of chronic caval dogs, which disappears when they lose avidity for sodium retention.

Aldosterone↗
PubMed1989

Heterogeneous renal responses to atrial natriuretic factor. II. Cirrhotic dogs.

The renal response to atrial natriuretic factor (ANF) (175 ng.kg-1.min-1) was tested in nine dogs during a control period and again after the appearance of experimental cirrhosis, ascites, and avid sodium retention. During the cirrhotic phase, plasma volume had increased by 28.4% (P less than 0.05), renal perfusion and glomerular filtration rate (GFR) were unchanged from control values, and plasma immunoreactive ANF (iANF) had declined from 71.6 +/- 9.5 to 34.7 +/- 5.4 pg/ml (P less than 0.05). During the control phase, change of urinary sodium excretion rate (delta UNaV) increased by 132 +/- 22 mu eq/min but was attenuated in the cirrhotic phase (delta UNaV = 29 +/- 12.5 mu eq/min). Of these nine cirrhotic dogs, five responded with a delta UNaV ranging from 20 to 114 mueq/min (mean delta UNaV = 59.6 +/- 10.6 mu eq/min), whereas 4 were nonresponders (delta UNaV = 1.3 +/- 0.6 mu eq/min). In neither group could delta UNaV be correlated to changes in GFR, clearance of p-aminohippurate, or filtration fraction. In an additional 10 dogs studied only during cirrhosis, 5 were natriuretic responders and 5 were nonresponders. Atrial content of ANF, half time of infused ANF, and plasma levels of iANF did not differentiate the two groups. We conclude that, like chronic caval dogs with ascites, salt-retaining cirrhotic dogs show heterogeneity of natriuretic response to infused ANF, which is unexplained by differences in renal perfusion.

Animals↗
PubMed1989

Response to atrial natriuretic peptide in dogs with hypovolemic acute pancreatitis.

The ability of atrial natriuretic peptide (ANP) to preserve renal function in dogs with hypovolemic acute renal insufficiency was tested in anesthetized dogs 4 h after the induction of acute pancreatitis. Plasma volume had decreased by 21.5% and glomerular filtration rate (GFR) by 43.2%. Blood pressure had declined by 30 mmHg. ANP was given intravenously at 50 and 150 ng.kg-1.min-1. With the lower dose, blood pressure (BP), GFR, and clearance of p-aminohippuric acid (CPAH) did not change but urine flow (V) and sodium excretion (UNaV) increased. With the higher dose, BP declined by 25 mmHg, GFR declined, but V and UNaV still increased. When plasma volume was maintained with 4% colloid during the progression of pancreatitis and ANP 50 ng.kg-1.min-1 given, BP declined, GFR did not change, and there was a magnified increment in V and UNaV. The administration of glucagon (5 micrograms/min iv) to dogs with hypovolemic pancreatitis caused BP to decline by 17 mmHg. Despite a major increment in GFR, fractional excretion of sodium increased only slightly, compared with that obtained with ANP. We conclude that glucagon preserves GFR more effectively than ANP in hypovolemia, but ANP is more effective in protecting urinary water and sodium excretion.

Acute Disease↗
PubMed1989

Assessment of children's Type A behavior: relationship with negative behavioral characteristics and children and teacher demographic characteristics.

Thirty-two teachers rated Type A behavior, using Matthews Youth Test for Health, (MYTH) and negative characteristics of hyperactivity, negative peer relations, social withdrawal, and depression in 105 children, between the ages of 6 and 11, from lower to middle class Black and White families. Children's age, gender, race, and socioeconomic status (SES) and teachers' gender, grade taught, and years of teaching experience were not related to teachers' MYTH ratings. However, White teachers rated children higher on Type A behavior than Black teachers. Controlling for teacher race effects, MYTH total scores, rather than reflecting a global negative view of the child, showed a strong overlap with hyperactivity and were differentiated from social withdrawal and depression. The MYTH Impatience/Aggression factor was highly related to hyperactivity and negative peer interactions; the Competitiveness factor was associated with a lack of social withdrawal. The conclusions verify the multidimensional nature of children's Type A behavior pattern and the importance of rater demographic characteristics in the assessment of children's behavior.

Black or African American↗