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Biomedical subjects

R Levy

Publications and source records attributed to R Levy.

At least 811 records · Page 45Linked to original sources
PubMed1976

Beneficial effect of lidocaine on ventricular electrical stability and spontaneous ventricular fibrillation during experimental myocardial infarction.

Several studies have questioned the efficacy of lidocaine in reducing the incidence of ventricular fibrillation shortly after acute myocardial infarction when arrhythmogenic mechanisms may be different from those operative several hours later. To determine whether lidocaine inhibits the occurrence of early ventricular fibrillation, the left anterior descending and septal coronary arteries were occluded at their origins in open chest anesthetized dogs. Fourteen of 16 control dogs died with ventricular fibrillation. Fifteen dogs received two different dose regimens of lidocaine before coronary occlusion. Of the 11 treated dogs maintaining lidocaine bl), 6 survived (P less than 0.05). Five dogs received the larger dose; all died, four having blood levels of 6.3 mug/ml or greater at the time of death. Ventricular fibrillation threshold also increased in six of eight dogs when lidocaine was administered after coronary occlusion. It is concluded that lidocaine at blood levels of 1.2 to 5.5 mug/ml significantly reduces the incidence of ventricular fibrillation early after coronary occlusion. Administration of this agent therefore may be of particular value in the early phase of acute myocardial infarction.

Animals↗
PubMed1976

[Detection of mineral oil and paraffin in foods].

The author describes a thin-layer chromatographic method for the detection of small amounts of mineral oil and paraffin in foods. Fatty acids, glycerides, fat-soluble vitamins, sterols, and unsaturated hydrocarbons remain at the starting point. This method permits to detect as little as 0.2 mug of mineral oil or 20 mug of mineral oil/kg of food in low-fat products. 0.01% of mineral oil-like contaminants may be detected in fats.

Animals↗
PubMed1975

The use of an interactive computer terminal in the assessment of cognitive function in elderly psychiatric patients.

The use of a teaching machine is the assessment of mental function has been described by Gredye and his colleagues. This report concerns its use in testing 56 elderly patients suffering from functional psychiatric disorders of dementia. After a diagnostic interview patients were tested on the teaching machine as well as on the Mill Hill, Progressive Matrices, Paired Associate Learning Test and Digit Copying Test. After a fixed period all tests were repeated and clincal progress rated. Results showed a significant correlation (P less than 0.01) between teaching-machine scores and those on the standard psychological tests. The correlation between the machine scores on the two occasions was high (r equals 0.58) but this was complicated by practice effects and by low 'ceiling' of the test. It is concluded that the test provided a relatively reliable and valid measure of cognitive function but that its value would be increased by providing a parallel form and by extending its level of difficulty.

Age Factors↗
PubMed1975

Detection of mannitol formation by bacteria.

A test is described by means of which formation of mannitol from fructose by lactic acid bacteria can be readily detected. The test is based on removal of interference of residual fructose by dehydration with hydrochloric acid followed by thin-layer chromatography.

Bacteriological Techniques↗
PubMed1975

In vitro cortisone sensitivity of in vivo cortisone-resistant thymocytes.

Thymus cells from untreated or hydrocortisone-treated mice were cultured for 20 hr in the presence or absence of a water-soluble glucocorticoid, hydrocortisone sodium succinate. By two independent assays of cell viability or function, virtually all thymocytes from untreated hosts were inactivated by hydrocortisone sodium succinate, whereas most, but not all, thymocytes from hydrocortisone-treated hosts were inactivated. Thus, the thymocytes which survive after treatment of the animal with glucocorticoids are only partially resistant to the effects of glucocorticoids in vitro.

Animals↗
PubMed1975

The covalent binding of daunomycin and adriamycin to antibodies, with retention of both drug and antibody activities.

Daunomycin and adriamycin, two potent cancer chemotherapeutic agents, were linked to immunoglobulins, making use of various covalent cross-linking methods. The most suitable method for binding of the drugs to the antibodies, which retained both antibody and drug activity, was periodate oxidation of the drug, followed by the linking of the oxidized drug to the immunoglobulin and subsequent reduction of the product with sodium borohydride. The activity of the drug-antibody conjugates was tested in vitro on tumor and normal cell cultures and was found to be similar to that of the free drug. A significant amount of antibody activity was retained, as found both with anti-bovine serum albumin antibodies, assayed by chemically modified bacteriophage, and with anti-mouse tumor antibodies, assayed by C'-dependent cytotoxicity.

Animals↗
PubMed1975

The specific cytotoxic effects of daunomycin conjugated to antitumor antibodies.

Daunomycin was covalently bound to immunoglobulins by periodate oxidation as described in the preceding paper. Conjugates were prepared with immunoglobulins directed against either of two mouse lymphoid tumors or with nonspecific immunoglobulins. These conjugates were tested for their toxic effects on various tumor target cells as measured either by their inhibition of RNA synthesis or by their reduction of the growth of the tumor cells after transplantation. We found that the drug preferentially affected the target cells that the antibody to which it was attached could recognize. These daunomycin-antibody conjugates are therefore sufficiently toxic and selective in their effects to be potentially useful in in vivo therapeutic studies.

Animals↗
PubMed1974

Coronary hypertonia and angina.

Coronary hypertonia was observed in a patient with unstable angina. It was possible on one occasion to reproduce the clinical picture, electrocardiographic changes, lactate production and coronary hypertonia by means of atrial pacing. He had a normal left coronary arteriogram when the diffuse spasm was relieved by nitroglycerin. Therefore hypertonia (or spasm) of the left coronary artery was believed to be the cause of his variant angina with subendocardial ischemia.

Angina Pectoris↗