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Biomedical subjects

A Levy

Publications and source records attributed to A Levy.

At least 469 records · Page 26Linked to original sources
PubMed1977

[Halothane hepatitis].

Explore the source record for details and available documents.

Chemical and Drug Induced Liver Injury↗
PubMed1976

Disposition of propranolol isomers in mice.

l-Propranolol was found to protect mice from hyperbaric oxygen-induced seizures. The disposition of effective doses of propranolol isomers in mice was followed using stereospecific antibodies with a radioimmunoassay procedure. Serum and tissue concentrations were determined and correlated with the protective effect. Following racemic administration, there were no differences in serum disposition of d- and l-propranolol, although there was initially a preferential uptake of the 1-isomer both into cardiac and brain tissue. The d-isomer exerted synergistic action on the 1-isomer protective effect.

Animals↗
PubMed1976

Truncus arteriosus communis. Clinical, angiocardiographic, and pathologic findings in 100 patients.

Salient clinical, hemodynamic, angiocardiographic, and pathologic findings are presented in 100 patients with truncus arteriosus communis, 79 of whom were studied at autopsy. In this study of typical truncus, all had a ventricular septal defect (type A). Truncus with a partially formed aorticopulmonary septum (type A1) was much the commonest form (50%). Cases with no remnant of aorticopulmonary septum (type A2) were second in frequency (21%). The distinction between types A1 and A2 could not be made with certainty in 9%, because these types merge into one another. Cases with absence of either pulmonary artery branch (type A3) were the least frequent form (8%). Truncus with interruption, atresia, preductal coarctation, or severe hypoplasia of the aortic arch (type A4) constituted 12%. The diagnosis of truncus is primarily angiocardiographic. The plane of the truncal valve in the lateral projection is distinctive. It tilts anteriorly, facing the patient's toes, which can be of assistance in differential diagnosis. The angiocardiographic features of type A4, although unfamiliar, are pathognomonic. Since the median age at death was only 5 weeks, and in view of the difficulties associated with pulmonary artery banding, our goal should be the surgical correction of truncus during the first and second months of life.

Adolescent↗
PubMed1976

Colonoscopic perforation: its emergency treatment.

One of the accepted complications of colonoscopy is perforation. This is known to occur in greater frequency in patients having undergone previous pelvic or colonic surgery, as well as patients suffering from diverticulosis. A case is presented of colonic perforation during diagnostic examination in an area of adhesions secondary to pelvic surgery. Immediately after the perforation, the patient entered into vascular collapse and respiratory distress, with a distended abdomen. The introduction of a large bore intravenous catheter into the abdominal cavity with the release of the pneumoperitoneum resulted in an instantaneous return of vital signs and the patient subsequently underwent surgery and recovered. It is felt that this method of emergency treatment can be life-saving in a patient perforating during colonoscopy.

Catheterization↗
PubMed1976

Antibodies as a means of isolating and characterizing biologically active substances: presence of a non-peptide, morphine-like compound in the central nervous system.

Antibodies generated against small molecular weight substances such as drugs are being used to isolate and characterize biologically active agonists. A morphine-like compound can be extracted from brain of various species which has determinant groups that are recognized by specific morphine antibodies. It has a regional distribution which can be quantitated as immuno-equivalents. Immunological, chemical and chromatographic tests show great similatiries of the compound to morphine. This morphine-like compound has biological activity as it inhibits the electrically induced contractions both of the guinea pig ileum and mouse vas deferens but the inhibition is not reversed by naloxone or naltrexone.

Animals↗
PubMed1976

Endoscopy of the upper gastrointestinal tract.

Fiberendoscopy of the upper gastrointestinal tract recently has become a routine diagnostic procedure. This is due to its broad spectrum of applications and to its "reputation" of simplicity and innocuousness. The possible complications of fiberendoscopy, however, are similar to those of rigid endoscopy. Most of these complications can and must be avoided by strict adhesion to elementary precautions: adequate teaching and supervision of endoscopists in training; emphasis on all stages of the patient's preparation, psychological and pharmacological, each adopted to the individual patient and constant awareness of the possibility of complications.

Bacterial Infections↗
PubMed1976

[Chromosome effect of cyclophosphamide in various strains of mice].

The chromosomes of four different mouse strains were examined after administration of a single dose of cyclophosphamide, 100 mg/kg. Chromosomal breaks and rearrangements were produced in C3H mice three to four times as frequently and in AKR mice twice as frequently as in C57 B1 and XLII Orl mice. This indicates that cytogenetic investigations in mutation research using mice as in vivo test systems may be variable depending on the mouse strain employed. Because the effect of the alkylating agent was not pronounced in the two strains having a high incidence of cancer and leukemia (C3H and AKR), the possibility of a relationship between chromosomal instability and cancer proneness is discussed.

Animals↗
PubMed1976

Stereospecific radioimmunoassay for propranolol isomers.

Antisera against propranolol were produced in rabbits immunized with propranolol conjugated to bovine serum albumin. The antiserum against dl-propranolol recognized both d- and l-propranolol to the same degree. However, antiserum against l-propranolol was able to discriminate the l-propranolol selectively. The antisera were used to develop radioimmunoassays for dl-propranolol and l-propranolol. The assay can detect as little as 10 pg of propranolol. Metabolites of propranolol do not interfere with the assay unless concentrations are very high. Serum and heart levels of l-propranolol and the d-isomer were determined in the rat after i.v. injection (1 mg/kg) of dl-propranolol. l-Propranolol declines rapidly in the blood after the injection. Concomitantly, there is a rapid accumulation of l-propranolol by the heart. The d-form of propranolol remains in the blood and is metabolized rapidly as reflected by a shorter half-life (23.8 minutes) than the one found for l-propranolol (5.20 minutes).

Animals↗
PubMed1975

Metrizamide density gradients of sea urchin chromatin: fractions rich and poor in nascent DNA.

A crude, lightly sheared chromatin preparation obtained from a mixture of [methyl-3H] thymidine pulse and [2-14C] thymidine long-labeled sea urchin embryos (swimming blastulae), was centrifuged in metrizamide to form an isopycnic gradient. The buoyant density of the 3H pulse labeled chromatin was slightly higher than that of the 14C labeled bulk chromatin. The 3H/14C ratios in the higher and lower density regions of the overlapping radioactivity peaks, indicated the presence of fractions rich and poor in nascent DNA in these two density regions. After 15 min chase, the difference disappeared, indicating that the chromatin fractions with nascent DNA have a half-life shorter than 15 min.

Animals↗
PubMed1975

[Spinal cord compression in multiple cartilagineous exostoses (case report)].

A 53-year-old patient with multiple cartilagineous exostoses developed narrowing of the thoracic spinal canal with compression of the cord and spastic paraplegia. The importance of radiologic examination of the whole spine as well as of the extremities is emphasized. When there is an exostosis in the spine neurologic examination disclosing cord compression should be carried out at regular intervals. If there are signs of cord compression, early decompressive laminectomy is the treatment of choice.

Arthritis↗