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Biomedical subjects

G Levy

Publications and source records attributed to G Levy.

At least 217 records · Page 12Linked to original sources
PubMed1989

Induction of macrophage procoagulant activity by Bacteroides fragilis.

Fibrin deposition in the peritoneal cavity during acute peritonitis appears to predispose the host to abscess formation by providing an environment for bacterial proliferation protected from host defenses. The purpose of the present study was to determine whether the potent abscess-inducing anaerobe Bacteroides fragilis could promote fibrin deposition by inducing mononuclear cells to express procoagulant activity (PCA). B. fragilis stimulated PCA in a dose-dependent fashion, achieving a maximum at 10(7) CFU/ml. Heat-killed B. fragilis induced comparable levels of PCA, while a nonspecific phagocytic stimulus, latex beads, was not stimulatory. B. fragilis was capable of inducing PCA even when phagocytosis was blocked by preexposure of cells to latex beads. The results suggested that phagocytosis was neither necessary nor sufficient for the generation of PCA. Cell separation studies showed that PCA was solely produced by macrophages and that lymphocytes did not augment its production. These studies suggest one potential mechanism by which B. fragilis might initiate abscess formation.

Animals↗
PubMed1989

Transient tachypnoea of the newborn and asthma.

A total of 58 children aged 4-5 years who were diagnosed as having transient tachypnoea of the newborn were studied. In contrast with the control group (n = 58), the infants with transient tachypnoea of the newborn had a significantly higher incidence of recurrent (more than two) episodes of wheezy breathlessness, symptoms consistent with asthma, and signs consistent with atopy.

Asthma↗
PubMed1989

Kinetics of drug action in disease states. XXIX. Effect of experimental nephrotic syndrome on the pharmacodynamics of heptabarbital: implications of severe hypoalbuminemia.

The purpose of this investigation was to determine the effect of nephrotic syndrome (NS) on the pharmacodynamics of a barbiturate. NS was induced in male rats by puromycin aminonucleoside; it caused hypoproteinemia, increased liver and kidney weight and elevated serum creatinine and urea nitrogen concentrations. Serum albumin concentration decreased from 3.5% in controls to 0.90% in NS animals. The rats were infused i.v. with heptabarbital, 1 mg/min, until they lost their righting reflex. The total dose (mean +/- S.D.) required by rats with NS, 40.2 +/- 4.2 mg/kg, was substantially lower than that required by normal animals (68.6 +/- 6.2 mg/kg, P less than .001). Serum protein binding of heptabarbital was reduced from 49% in controls to 26% in NS rats. However, the drug concentration in cerebrospinal fluid (CSF) at the pharmacologic endpoint was not significantly different in controls and NS rats (18.9 +/- 1.5 vs. 18.3 +/- 1.4 mg/l). Serum, CSF and the brain contained appreciable concentrations of a metabolite of heptabarbital. To determine if the metabolite contributes to the pharmacologic effect of the parent drug, rats received an i.v. injection of 46, 60 or 100 mg/kg of heptabarbital. Concentrations of heptabarbital in CSF at return of righting reflex (which occurred after 15, 25 and 50 min, respectively) were independent of dose whereas metabolite concentrations increased with increasing dose. Thus, the metabolite of heptabarbital in male rats is pharmacologically inactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Kinetics of drug action in disease states. XXXVII. Effects of acute fluid overload and water deprivation on the hypnotic activity of phenobarbital and the neurotoxicity of theophylline in rats.

Fluid overload and dehydration are potentially serious physiologic perturbations. Their effects on the pharmacodynamics of drugs are essentially unknown. This investigation was designed to determine the effects of acute fluid overload or water deprivation on the hypnotic activity of phenobarbital and on the neurotoxicity of theophylline in male Lewis rats. In the first experiment, 5% dextrose in water (D5W) was infused i.v. in an amount equal to 5 or 10% of body weight and phenobarbital was infused immediately thereafter until the onset of loss of righting reflex (LRR). The total infused dose and the serum and cerebrospinal fluid (CSF) concentrations of phenobarbital at that time were significantly lower than in control animals. When phenobarbital was infused about 2.5 hr after D5W, the infused dose and the serum and CSF concentrations of phenobarbital at LRR were normal. When the rats received D5W and an injection of vasopressin, 25 I.U./kg, or vasopressin only, the infused dose and the serum and CSF concentrations of phenobarbital at LRR were significantly lower than in controls despite the 2.5-hr interval between the respective pretreatments and the phenobarbital infusion. Water deprivation for 24 or 48 hr had no significant effect on phenobarbital dose and concentrations at LRR. Intravenous infusion of D5W to 10% of body weight immediately or 2.5 hr before theophylline infusion had no significant effect on the total infused dose and the serum and CSF concentrations of theophylline at onset of maximal seizures. This lack of effect occurred despite appreciable hyponatremia and hypomagnesemia immediately after D5W infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Aspartame and phenylalanine do not enhance theophylline-induced seizures in rats.

Oral administration of the artificial sweetener aspartame, 1 g/kg, or of an equimolar dose of its metabolite phenylalanine, to fasted rats 1 hour before slow i.v. infusion of theophylline until the onset of maximal seizures had no significant effect on the total dose and the serum and cerebrospinal fluid concentrations of theophylline at the pharmacologic endpoint. These findings indicate that consumption of aspartame is not a potential risk factor for theophylline-induced neurotoxicity.

Animals↗
PubMed1989

[The interview in dental clinical examination: the role of reformulation].

Faced to the major role of the patients examination as a part of our interventions in dentistry, and with to our pedagogic mission towards students, we propose a method of interviewing the patients based on the principle of reformulation, basic technique in the help-talk. The described experimentation demonstrates the interest of method compared with the classical "interrogatory", particularly with rebellious or "problematic" patients. The personalized interview is efficient in obtaining their cooperation which is a key factor for the subsequent treatment.

Adult↗
PubMed1989

[Guided teaching with the Philips 6/6 method].

Complementary to the didactic lecture, the guided teaching system enables the students to formulate and resolve one or more problematic cases specific to the topic. The application of the PHILIPS 6/6 inter-active non-directive method, allowed us through the teaching of a simple subject (the rubber dam in restorative dentistry) to emphasize the multiple performances of group dynamics as applied to dental education.

Dentistry, Operative↗
PubMed1989

[A comparative study of pulsed Doppler versus continuous Doppler technic without spectral analysis in obstetrics].

We conducted a study in 48 parturients in order to: --assess the possibilities of continuous Doppler examination without preliminary ultrasonographic localization and without spectral analysis, to measure the traditional hemodynamic parameters of fetal development (in particular on the umbilical cord). --to compare these results with those obtained using pulsed Doppler-scan as reference. The protocol was very strict and neither of the two practitioners was aware of the other practitioner's results. With the continuous Doppler examination, the uterine arteries were systematically localized and recorded. The technique is simple in trained hands. The material included an ultrasonograph fitted with two probes (3.5 and 5 MHz, equipped with a pulsed Doppler) and a continuous Doppler (only the 4 MHz probe was used). Because the tests were sometimes repeated, 63 measurements were obtained in 48 parturients, mean age was 29.3 years and mean gestational age was 32.9 weeks. The reason for the examination varied: intrauterine growth retardation and/or maternal hypertension, diabetes, etc. The results obtained from the cord proved to be very encouraging: 42 of the 54 measurements were comparable (77.7%) showed an index difference less than or equal to 0.05. Only 4 (7.4% of the measurements) maximum deviations were observed (exceeding 0.10). The mean Pourcelot index on the Doppler scan was 0.677. With the continuous Doppler, it was 0.676. The 13 abnormal measurements with the pulsed Doppler were also abnormal with the continuous Doppler. The uterine arteries were recorded and measured with the continuous Doppler 42 times on the right (68.8% of the cases) and 34 times on the left (55.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Tubal adenocarcinoma. Apropos of 4 cases and review of the literature].

The authors describe 4 cases of tubal cancer reported in the gynaecology department of the University Hospital in Caen and review the international literature. If all authors are in agreement on the early symptoms (leukorrhea, haemorrhages, pelvic pain), the lack of diagnosis before the procedure, the lack of information regarding the staging and the grading, as well as the surgical and radiation treatment, there is, above all, controversy regarding the use of chemotherapy, since the low number of patients in the different series does not permit reaching a conclusion.

Adenocarcinoma↗
PubMed1989

Kinetics of drug action in disease states. XXXIV. Effect of experimental thyroid disorders on the pharmacodynamics of phenobarbital, ethanol and pentylenetetrazol.

To determine the effect of thyroid disorders on the concentration-activity relationship of certain drugs acting on the central nervous system, rats were made hyperthyroid by administration of L-thyroxine and hypothyroid by administration of propylthiouracil. They then received a slow i.v. infusion of phenobarbital or ethanol until they lost their righting reflex, or of pentylenetetrazol until the onset of maximal seizures. Drug concentrations in serum, brain and cerebrospinal fluid (CSF) were determined at these pharmacologic endpoints. Hyperthyroidism was associated with a statistically significant increase in the infused hypnotic dose and brain concentration of phenobarbital but had no apparent effect on concentrations of the drug in serum and CSF. The hypnotic dose of ethanol was increased significantly in hyperthyroid rats and decreased in hypothyroid animals; ethanol concentrations in serum, brain and CSF at onset of effect were generally not affected by thyroid dysfunction except for a small but statistically significant increase of serum ethanol concentrations in the hyperthyroid rats. The convulsant dose of pentylenetetrazol was reduced significantly in hypothyroid animals and unaltered in hyperthyroid rats; the concentrations of the convulsant in serum, brain and CSF were not apparently changed by the thyroid dysfunctions. In general, experimental thyroid disorders had no pronounced effect on the pharmacodynamics (concentration-effect relationship) of phenobarbital, ethanol and pentylenetetrazol in rats.

Animals↗