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Biomedical subjects

J Levy

Publications and source records attributed to J Levy.

At least 199 records · Page 11Linked to original sources
PubMed1994

Obesity associated insulin resistance occurs in hypopituitary subjects.

The study aimed to assess the role of pituitary hormones in the relationship between insulin resistance and obesity. Twelve male subjects with hypopituitarism secondary to surgery for a non-functioning pituitary adenoma were recruited. Subjects were receiving replacement hormones. Fasting plasma samples were taken for insulin, C-peptide, glucose, and lipids. Body mass index and blood pressure were measured. In hypopituitary subjects on replacement therapy, a positive association between body mass index and fasting plasma insulin levels (r = 0.76, p < 0.004) was similar to that found in normal subjects. In conclusion pituitary function does not have a direct role in determining the relationship between fasting plasma insulin, an index of insulin resistance, and obesity.

Humans↗
PubMed1994

Detection of 4-quinolone resistance mutation in gyrA gene of Shigella dysenteriae type 1 by PCR.

To study 4-quinolone resistance, the N-terminal coding region of gyrA from nalidixic acid-susceptible and -resistant isolates of Shigella dysenteriae type 1 was amplified by PCR, cloned, and sequenced. DNA sequence analysis of gyrA from nalidixic acid-resistant isolates revealed a C-to-T transition at nucleotide position 248 leading to a Ser-83-to-Leu substitution which was absent in susceptible clinical isolates. Direct HinfI digestion of PCR-amplified DNA detected similar mutations. Thus, DNA gyrase A subunit mutation Ser-83 to Leu is implicated in 4-quinolone resistance in S. dysenteriae type 1.

4-Quinolones↗
PubMed1994

Relation of Helicobacter pylori infection and coronary heart disease.

BACKGROUND: There is evidence suggesting that early life experience may influence adult risk of coronary heart disease (CHD). Chronic bacterial infections have been associated with CHD. OBJECTIVE: To determine whether Helicobacter pylori, a childhood acquired chronic bacterial infection, is associated with an increased risk of coronary heart disease in later life. DESIGN: Case-control study controlling for potential confounding variables with an opportunistically recruited control group. SUBJECTS: 111 consecutive cases with documented CHD were recruited from a cardiology clinic and 74 controls from a general practice health screening clinic. All were white men aged 45-65. METHODS: Serum was analysed for the presence of H pylori specific IgG antibodies by ELISA (98% sensitive and 94% specific for the presence of infection). RESULTS: 59% of the cases and 39% of the controls were seropositive for H pylori (odds ratio 2.28, chi 2 7.35, p = 0.007). After adjustment by multiple logistic regression for age, cardiovascular risk factors, and current social class, the effect of H pylori was little altered (odds ratio 2.15, p = 0.03). Further adjustment for various features of the childhood environment known to be risk factors for H pylori infection only slightly weakened the association (odds ratio 1.9). H pylori seropositivity was not related to the level of risk factors in the control population. CONCLUSION: In this pilot study the association of adult coronary heart disease with H pylori seropositivity suggests that the early childhood environment may be important in determining the risk of CHD in adult life. The association needs confirmation in other better designed studies. If H pylori itself is responsible for the association, then this is of great potential importance as the infection is treatable.

Aged↗
PubMed1994

[Comparative study of lipids, apoproteins and lipoproteins in patients with coronary disease and in a control population].

We carried out a comparative study of various lipid parameters (apo AI and B, LpAI, Lp(a) and LpBCIII) in coronary heart disease patients (19 males and 4 females, mean age 61 +/- 11 years) and in controls (18 males and 14 females, mean age 55 +/- 3 years) selected so that cholesterol and triglycerides levels be beneath 6 and 2.3 mmol/l in both populations. Apo AI and B were analysed by immunonephelometry and lipoparticles by electroimmunodiffusion. Nonparametric statistics tests were performed on account of the small numbers in both groups. Our study confirms the protective effect of Lp AI but did not show an obvious superiority of Lp AI quantification compared to apo AI. It highlights the interest of Lp(a) as an independent and additional risk factor for atherogenesis: no obvious correlation with any other lipidic parameter was demonstrated. An increase in Lp(a) beyond 0.30 g/l increases atherogenic risk 2.5 fold. We did not show any benefit of LpBCIII quantification in 'normolipemic' coronary patients. In conclusion, a discriminant analysis including the apo B/apo AI and apo B/LpAI ratios and Lp(a) allows an accurate classification of 67% of the patients.

Apolipoproteins A↗
PubMed1994

[Stomatococcus mucilaginosus meningitis in immunocompromised child].

BACKGROUND: Opportunistic infections are responsible for significant morbidity and mortality in patients with malignancy developing granulocytopenia as a result of therapy. A case of Stomatococcus mucilaginosus meningitis is reported. CASE REPORT: A 2 year-old boy was admitted because he had developed fever and neutropenia during chemotherapy given for neuroectodermal tumor. He was previously treated for a Stomatococcus mucilaginosus septicemia with vancomycin given for 15 days through an intravenous catheter which has subsequently been left in place. At admission, fever was associated with severe degree of aplasia (70 WBC/mm3). The patient was given IV ceftazidime plus amikacin. Two days later, the boy developed acute meningitis due to Stomatococcus mucilaginosus; he was then given IV vancomycin (40 mg/kg/d) and imipenem (100 mg/kg/d). Persistence of abnormal clinical and bacteriological findings required subsequent intrathecal administration of vancomycin (1.5 mg/d) for 5 days. CSF cultures were negative 2 days later, leading to stop IV antibiotics after 3 weeks. The catheter was removed 1 week later. CONCLUSION: This patient represents the third reported case of Stomatococcus mucilaginosus meningitis. Combined intrathecal and systemic administration of vancomycin seems to have been useful in our case.

Child, Preschool↗
PubMed1994

Bile acid synthesis in HepG2 cells: effect of cyclosporin.

The hypothesis that cyclosporin specifically affects the pathway of bile acid synthesis that begins with 27-hydroxylation of cholesterol was evaluated in HepG2 cells, which synthesize chenodeoxycholic acid and cholic acid from endogenous 7 alpha-hydroxycholesterol. At a concentration in the medium of 8.3 microM cyclosporin, the proportion of cholic acid increased from 29 +/- 7% to 44 +/- 6% (P < 0.001) with no major change in total bile acid production. Chenodeoxycholic acid synthesis was enhanced by the addition of either 7 alpha-hydroxycholesterol or 5 beta-cholestane-3 alpha,7 alpha-diol to the medium and cholic acid synthesis was enhanced by the addition of 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol to the medium. Cyclosporin significantly inhibited only enhanced chenodeoxycholic acid synthesis, indicating a selective interference in mitochondrial side chain oxidation of less polar intermediates in bile acid synthesis derived from either initial 7 alpha- or initial 27-hydroxylation of cholesterol. The increase in the proportion of cholic acid that occurs in the presence of cyclosporin mimics that occurring in genetically determined sterol 27-hydroxylase deficiency (cerebrotendinous xanthomatosis). Cyclosporin is useful for dissecting the subcellular pathways of bile acid synthesis.

Bile Acids and Salts↗
PubMed1994

Cytologic characterization of bronchoalveolar lavage fluid collected through an endotracheal tube in cats.

Bronchoalveolar lavage was performed through an endotracheal tube in 34 specific-pathogen-free cats to determine expected values for bronchoalveolar lavage fluid cytologic analysis, using this method of collection. Saline solution for lavage was instilled in 3 separate aliquots at a volume of 5 ml/kg of body weight each. Analysis of sequential aliquots was performed to investigate the differences in cell counts among the 3 fractions. The effect of combining aliquots, including or omitting the first fraction, was evaluated to determine whether all aliquots could be combined for analysis without substantially affecting results. The total number of nucleated cells retrieved from each cat ranged from 0.9 to 31.1 x 10(6). Most of these cells were macrophages (78 +/- 15%, mean +/- SD) and eosinophils (16 +/- 14%). The first aliquot had the greatest number of epithelial cells, and the lowest total nucleated cell count and relative and absolute eosinophil counts. Differences among aliquots also were identified for relative and absolute macrophage counts, relative and absolute neutrophil counts, and absolute lymphocyte count. Statistically significant differences were found for many of the cell counts when values from the combination of the second and third aliquots were compared with values from the combination of all 3 aliquots. Magnitude of the differences was small, and these differences were not believed to be of practical consequence.

Animals↗
PubMed1994

Photodynamic inactivation of free and cell-associated HIV-1 using the photosensitizer, benzoporphyrin derivative.

The photosensitizer benzoporphyrin derivative monoacid ring A (BPD) has been investigated regarding its ability to destroy free and cell-associated human immunodeficiency virus type 1 (HIV-1) when activated by light. Experiments with free virus in tissue culture medium indicate that light-activated BPD was effective in rendering HIV uninfectious. Azidothymidine (AZT)-resistant strains of HIV appear equally susceptible to photodynamic inactivation under drug and light conditions that proved effective in inactivating AZT-sensitive strains of HIV. Experiments conducted on whole blood from individuals infected with HIV demonstrate that BPD and light treatment could significantly reduce cell-associated virus, under conditions that appear not to damage red blood cells. The amount of culturable virus from infected leukocytes surviving photodynamic treatment could be further reduced by the addition of AZT to the culture.

Cells, Cultured↗
PubMed1994

Association between preterm birth and increased maternal plasma cortisol concentrations.

OBJECTIVE: To measure the amniotic fluid (AF) and plasma concentrations of cortisol in women with preterm labor and intact membranes. METHODS: Thirty-eight normal healthy women with singleton gestations, preterm labor, and intact membranes at 32-36 weeks' gestation underwent amniocentesis for evaluation of the microbiologic status of the amniotic cavity. Nineteen women delivered within 1 week of amniocentesis (preterm labor and delivery group), and 19 delivered at term (preterm labor and term delivery group). Maternal plasma and AF concentrations of cortisol were measured with sensitive and specific, commercially available radioimmunoassay kits. RESULTS: The median plasma cortisol concentration was significantly higher in women who delivered prematurely than in those who delivered at term (260 versus 240 ng/mL; P = .014). However, no significant differences in median AF cortisol concentrations were detected between the groups (13 versus 14 ng/mL). CONCLUSIONS: Although maternal plasma cortisol concentrations were significantly higher in women with preterm birth, no similar changes were found in the AF. The rise in maternal plasma cortisol may be related to the stress mechanism of labor.

Adult↗
PubMed1993

Regulation of endometrial cancer cell growth by insulin-like growth factors and the luteinizing hormone-releasing hormone antagonist SB-75.

The involvement of IGFs in growth regulation of the Ishikawa endometrial tumor cell line and the possible interference of LH-RH analogues with a potential autocrine or paracrine loop involving IGFs was evaluated. The mitogenic effects of IGF-I, IGF-II, and insulin were compared. IGF-I was found to be 3-fold more potent than IGF-II and 30-fold more potent than insulin, suggesting that the effects of these growth factors are mediated by the IGF-I receptor. Ishikawa endometrial cancer cells secrete IGF-II, but not IGF-I, and insulin (1 microM) stimulates IGF-II release. The LH-RH antagonist [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]-GnRH (SB-75, CETRORELIX) inhibited basal and IGF-induced growth. Moreover, this antagonist almost completely inhibited IGF-II release from Ishikawa cells, while having no significant effect on the number or affinity of IGF-I binding sites. Inhibition of IGF-II release occurred at a lower SB-75 concentration than that needed for a reduction in cell number. The ED50 of SB-75 for IGF-II release was 0.3 microM as compared to 1.5 microns concentration which is required for reduction in cell number, suggesting that inhibition of growth factor release precedes cell growth inhibition. We conclude that the LH-RH antagonist SB-75 can inhibit the growth of endometrial cancer cells by interfering with the autocrine action of IGF-II and also by directly inhibiting the growth-stimulatory effects of IGFs, probably through effects on a post-receptor mechanism.

Cell Division↗
PubMed1993

Regional nodal management and patterns of failure following conservative surgery and radiation therapy for stage I and II breast cancer.

PURPOSE: To determine the incidence, pattern of regional nodal failure, and treatment sequelae as determined by the extent of lymphatic irradiation. METHODS AND MATERIALS: The records of 511 patients with 519 Stage I and II breast cancers treated with breast conserving surgery with or without axillary dissection and irradiation were reviewed. The extent of nodal irradiation was at the discretion of the attending radiation oncologist and varied considerably over the years. Management of the axilla consisted of axillary dissection alone in 351, axillary dissection and supplemental irradiation in 74, irradiation alone in 75, and simply observation in 21 patients. RESULTS: Overall, axillary recurrence was uncommon (1.2%), but was slightly more frequent after irradiation alone (2.7%) than after surgery alone (0.3%), p = 0.14. There was no benefit for supplemental axillary irradiation after an axillary dissection yielding negative or 1 to 3 positive nodes. In the 21 patients in whom the axilla was observed, axillary recurrence was not observed. Supraclavicular failures were rare in women with negative or 1 to 3 positive axillary lymph nodes (0.5%), and not significantly affected by elective irradiation. Internal mammary node recurrence was seen in only one patient, and was not significantly influenced by elective internal mammary irradiation. Both arm and breast edema were significantly more common in women having breast and nodal irradiation than after breast irradiation alone. These sequelae were not influenced significantly by the number of lymph nodes obtained in the axillary dissection specimen. Radiation pneumonitis was seen with increased frequency with more extensive nodal radiotherapy. Pneumonitis was not found to be affected by the administration or sequencing of chemotherapy. CONCLUSION: There is little justification for axillary or supraclavicular irradiation following an axillary dissection which yields negative or minimally involved (1 to 3 positive) lymph nodes. There were too few patients with extensive axillary node metastases (> or = 4 positive) in our series to draw conclusions about the optimal extent of nodal irradiation in this subset. Elective internal mammary lymph node irradiation increases technical complexity, does not appear to be advantageous, and when combined with supraclavicular irradiation places the patient at highest risk for pneumonitis.

Adult↗