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Biomedical subjects

J Levy

Publications and source records attributed to J Levy.

At least 343 records · Page 19Linked to original sources
PubMed1988

Antibiotic therapy in cystic fibrosis. Evaluation of efficacy.

Eradication of the bacterial pathogen, resolution of the local and systemic inflammatory signs, and recovery of organ function are the main criteria by which antibiotic treatment is evaluated. In cystic fibrosis (CF) the pathogen is seldom eradicated and systemic markers of inflammation are not always present. The main criterion for assessing the results of antimicrobial therapy in CF is therefore clinical improvement. The use of clinical scoring systems and double-blind design in therapeutic trials can reduce bias in evaluation of outcome. Assessment of the contribution of antibiotic therapy to the outcome requires greater knowledge of the role of bacterial infection in the pathogenesis of pulmonary exacerbations and could be improved by the development of quantifiable markers in respiratory secretions for inflammation.

Acute Disease↗
PubMed1987

Community-acquired bacteraemia in African children.

To examine the frequency of community acquired bacteraemia in children in Kigali, Rwanda, blood cultures were obtained from 900 consecutive febrile children (T degrees greater than or equal to 39 degrees C) seen at an outpatient clinic over the course of a year. A pathogen was isolated from 112 children (12.4%): Salmonella typhi from 47, S enteritidis from 23, S typhimurium from 13, Streptococcus pneumoniae from 14, Staphylococcus aureus from 9, and Haemophilus influenzae from 3. Salmonella species represented 74% of the isolates. The children with S typhi bacteraemia were older (mean age 75 months) than those with bacteraemia due to other organisms. Controls consisted of febrile, nonbacteraemic children without (group I) or with (group II) Plasmodium falciparum parasitaemia. Bacteraemic children were older and presented more frequently with diarrhoea, vomiting, and dehydration, but less frequently with convulsions than controls. The rate of hospital admission was higher among bacteraemic children (61%) than among group I (39%) or group II (46%) controls. The case-fatality rate was similar in the three groups (9.3% versus 2.9% and 7.3%). Community-acquired bacteraemia in Rwandese children is common and is mainly caused by Salmonella species.

Age Factors↗
PubMed1987

The use of theophylline clearance in pediatric status asthmaticus. I. Interpatient and intrapatient theophylline clearance variability.

A group of 167 pediatric asthmatics were followed up over four years, and their theophylline clearance values were recorded when they were admitted for status asthmaticus. A slow and gradual decrease of the clearance value was noted in all age groups. The clearance did not change significantly between the ages of 2 and 9 years. Longitudinal intrapatient clearance changes achieved statistical significance after the age of 9 years. When the patient groups were studied according to their initial clearance values, it became evident that only the patients with clearance values of 80 mL/kg/h showed significant changes of this value. In our patient group, obesity did not play a significant role in effecting a change in theophylline clearance.

Acute Disease↗
PubMed1987

The use of theophylline clearance in pediatric status asthmaticus. II. The choice of appropriate dose for the intravenous theophylline infusion.

We developed an individualized approach for determining the intravenous rate of theophylline infusion for the treatment of status asthmaticus in children. The method is based on the individual's theophylline clearance rate as determined at previous admissions. We compared the method with two standard recommended approaches used currently in clinical pediatrics--the American Academy of Pediatrics and the Food and Drug Administration guidelines.

Administration, Oral↗
PubMed1987

Estrogen and progesterone receptor levels are lower in specimens taken from previously biopsied breast tumor tissue.

Estrogen and progesterone receptor (ER and PgR) levels and peroxidase activity were measured in the first biopsy and in tissue removed 4-10 days later during mastectomy of previously biopsied tumor. The proportion of ER- and PgR-positive tumors declined from 71% and 63%, respectively, in the biopsy group, to 46% and 36% in the mastectomy group. Peroxidase activity was low or absent in all biopsy specimens, but was present in 16 out of 25 tumors which had been biopsied previously. Receptor levels in paired specimens obtained from the same patient were lower in the mastectomy in 14 out of 18 receptor-positive cases. This decrease in the receptor level was accompanied by a significant increase in peroxidase activity. We suggest that an attempt be made to perform receptor analysis from "virgin" tumor tissues at initial biopsy. If this is not possible, measurement of peroxidase activity could be helpful in evaluating the degree of receptor deterioration.

Biopsy↗
PubMed1987

Pediatric AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1987

GnRH analogs stimulate phospholipase C activity in mammary tumor membranes: modulation by GTP.

An in vitro assay for phospholipase C activity was developed, employing exogenously added 32P-labelled phosphatidylinositol 4,5-bisphosphate as substrate. This enzymatic assay used to analyse the direct effect of GnRH on mammary tumors. GnRH agonists stimulate membranal phosphoinositide-specific phospholipase C activity. The increase in inositoltrisphosphate production is dose dependent, and is inhibited by the GnRH antagonist Org-30276. We took advantage of this non-cellular assay system for evaluating the role of G-binding proteins in the phosphoinositide transducing system in mammary tumors. GTP gamma S stimulates the basal and GnRH-dependent phospholipase C activity. This effect was abolished by GDP beta S. The cytosolic phospholipase C activity was also stimulated by GTP gamma S but was not affected by the hormone. These results suggest that GnRH may affect the growth of mammary tumors directly and not only through the reduction of blood gonadotropin level.

Animals↗
PubMed1987

Mineral homeostasis in neonates of streptozotocin-induced noninsulin-dependent diabetic rats and in their mothers during pregnancy and lactation.

To assess the affect of mild diabetes on calcium metabolism in an animal model, we evaluated calcium homeostasis before pregnancy and during gestation and lactation in non-insulindependent (NIDD) diabetic rat mothers and their neonates (NeoDM). Plasma glucose, calcium (Ca), magnesium (Mg), phosphate (Pi), and immunoreactive parathyroid hormone (iPTH) were measured in the NIDD rats and controls before pregnancy, during the first, second, and third gestational week, and during lactation 12, 24, 48 and 72 h postpartum. The same measurements were performed on NeoDM and controls 12, 24, 48, and 72 h after birth. In the mothers, plasma calcitonin was assayed before pregnancy and at 72 h postpartum. Higher plasma glucose values before pregnancy (216 +/- 9 mg/dl vs 126 +/- 4) and during the second (105 +/- 5 vs 73 +/- 6) and third (114 +/- 8 vs 91 +/- 3) gestational week were observed in diabetic mothers when compared to controls. Glucose values decreased during the second and third gestational week in both groups compared to pregestational values. Plasma Ca, Mg, and Pi were similar in both groups during gestation and lactation except for the third gestational week when plasma Mg was lower in the diabetic mothers (P less than 0.05). Plasma iPTH rose to similar values in both groups during pregnancy. During lactation, plasma iPTH levels were higher and plasma calcitonin levels were lower compared to controls (P less than .05, P less than 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

High pressure liquid chromatographic quantitation of teicoplanin in human serum.

A reverse phase high-pressure liquid chromatographic method to assay teicoplanin in serum is described. The procedure involves a single protein precipitation step with acetonitrile containing the internal standard mephenesin, followed by direct injection of the supernatant into the chromatograph. This HPLC method has good linearity, precision, recovery and sensitivity over the range of serum concentrations observed with the recommended dosages of the drug (5-50 mg/l). The assay has been validated by a correlation study with a bioassay on 97 sera obtained from patients treated with teicoplanin (r = 0.9519, P less than 0.001). The small serum sample size (100 microliters) and the use of a common C18 column make this assay ideal for drug monitoring, provided that HPLC equipment is available.

Anti-Bacterial Agents↗
PubMed1987

Biliary atresia and noncardiac polysplenic syndrome: US and surgical considerations.

Ten percent of children with biliary atresia have an associated complex of anomalies, including polysplenia, azygous continuation of the inferior vena cava, preduodenal portal vein, hepatic arterial anomalies, and bilaterally bilobed lungs. These abnormalities will not be detected if the preoperative workup is limited to hepatobiliary nuclear scanning. Ultrasonography is important in the preoperative evaluation of patients suspected of having biliary atresia. It is important to identify the associated abnormalities preoperatively because they have an impact on the initial portoenterostomy and may preclude subsequent orthotopic liver transplantation.

Arteriovenous Malformations↗
PubMed1987

Effect of aging and exercise on the kidney. Anatomical and morphological studies.

The effect of short-term endurance exercise on the kidneys of C57BL/6J mice of various ages was studied. While as a function of age there was a slight increase in the ratio of kidney weight to body weight, after 6 weeks of training there was a significant hypertrophy of kidneys of old mice compared to young ones. In addition to these gross anatomical studies, light- and electron-microscopic studies were performed. Using light microscopy, semiquantitative morphological assessment of kidney damage revealed that in young animals about 66% of total glomeruli were characterized as normal. 32% of the glomeruli were singled out as slightly damaged but still functioning. These values remained basically the same for kidneys of young animals trained for 6 weeks. In old mice, on the other hand, only 37% of total glomeruli were characterized as normal morphologically, and over 60% showed various degrees of kidney sclerosis. Exercise for 6 weeks reduced the proportion of normal-appearing glomeruli to 6.25%, while the damaged glomeruli of all types increased to over 90%. Electron-microscopic pictures revealed an increased amount of mesangial damage and severe obliteration of capillary lumens in aging animals. These changes were magnified in old running mice. The results may indicate that while kidneys of young animals were not affected by 6 weeks of exercise, kidneys of old animals were adversely affected by this type of exercise regimen.

Aging↗
PubMed1987

The effect of insulin concentration on retroendocytosis in isolated rat adipocytes.

After internalization by isolated rat adipocytes, insulin can be degraded or released intact from the cell, a process termed retroendocytosis. To determine whether the amount of ligand entering the cell could modulate its ultimate intracellular disposition, adipocytes were incubated with 0.4-25 ng/ml radiolabeled insulin for 20 min at 37 C to reach steady state binding and internalization. After this, surface bound insulin was removed by acid extraction and the cells were reincubated in insulin-free 37 C buffer. The fractional rate of release of internalized cell associated radioactivity was similar at all insulin concentrations. However, insulin enhanced the appearance of trichloroacetic acid (TCA)-precipitable material in a dose-dependent manner reaching a maximum at an insulin concentration of 10 ng/ml. At 0.4 ng/ml insulin, 18 +/- 2% of the released radioactivity was TCA precipitable whereas 36 +/- 3% was precipitable at 25 ng/ml. Sephadex G-50 gel chromatography and reverse phase HPLC analysis of the reincubation medium confirmed TCA-precipitable material was intact insulin. To further investigate the dual pathways of intracellular insulin processing, adipocytes were incubated with 0.4 and 25 ng/ml insulin for 20 min, acid extracted to remove surface receptor insulin, and solubilized. Sephadex G-50 and HPLC analysis revealed that proportionately less insulin intermediates and low molecular weight degradation products are found in cells incubated at the higher insulin concentrations. In conclusion, as adipocytes internalize more insulin, less is converted into insulin intermediates and low molecular weight degradation products and more is diverted to retroendocytosis.

Adipose Tissue↗