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Biomedical subjects

E Cohen

Publications and source records attributed to E Cohen.

At least 307 records · Page 17Linked to original sources
PubMed1984

Simple method for collagenase determination in 38 Pseudomonas aeruginosa strains.

Collagenase enzyme activity of 38 Pseudomonas aeruginosa strains and 38 strains of Escherichia coli from various pathological sources was measured by a simple method. This method uses plates with collagen gel. The rate of gel lysis is proportional to the collagenase concentration. The method is simple and requires no special materials or equipment. From the 38 P. aeruginosa strains, 34 were collagenase positive. All 38 strains of E. coli were collagenase negative.

Animals↗
PubMed1984

Use of nitroprusside during surgery for thoracoabdominal aortic aneurysm.

To assess the effects of sodium nitroprusside on the deleterious hemodynamic effects of clamping and unclamping of the aorta during resection of thoracoabdominal aortic aneurysm without the use of a shunt, 50 patients were studied. The risk factors included coronary artery disease (44%) associated with previous myocardial infarction (28%), hypertension (70%), congestive heart failure (6%), chronic obstructive pulmonary disease (34%), asthma (2%), and renal insufficiency (2%). Sodium nitroprusside infusion (3 micrograms/kg/min) was started before clamping and discontinued before unclamping of the aorta. The infusion rate was adjusted to maintain blood pressure and pulmonary capillary wedge pressure within the range of control. During cross-clamping cardiac index in the patients remained unchanged and even increased on unclamping, suggesting that left ventricular function was efficiently protected during these periods. All the patients survived the surgery, and the 30 day mortality was only 4%. Our data indicate that major aortic surgery can be carried out safely with the use of nitroprusside rather than of mechanical techniques to provide proximal decompression.

Adult↗
PubMed1983

Human lymphocyte agglutinins in Tursiops truncatus (bottlenose dolphin).

A naturally occurring heterophile agglutinin directed against human erythrocytes and lymphocytes is present in the serum of the marine mammal, Tursiops truncatus (Bottlenose dolphin). Differential specificity was demonstrated with the use of absorption techniques that showed at least 3 separate specificities directed against erythrocytes, T cells, and B cells, of which the B cell agglutinin was in the highest titer. Isolation techniques employing ion exchange and affinity chromatography have shown these agglutinins to be of the IgM class. Agglutinin activity is lost when lymphocytes are treated with pronase, suggesting that the surface receptor is protein or protein associated.

Agglutination Tests↗
PubMed1983

Discussion of statistical methods for determining purity of citrus juice.

It is difficult to develop statistical methods to determine the purity of fruit juice because of country-to-country and environmental differences among fruit. A test of an unknown sample of citrus juice can err in 2 ways: Pure juice can mistakenly be rejected as adulterated, or adulterated juice can be accepted as pure. Many of the statistical procedures proposed may misclassify a high proportion of samples of pure juice as adulterated. It is necessary to develop a statistical test that will only rarely reject samples of pure juice, and will have a good chance of rejecting adulterated juice.

Beverages↗
PubMed1982

Follow-up adjuvant chemotherapy and chemoimmunotherapy for stage II and III carcinoma of the breast.

Patients with stage II or III carcinoma of the breast were assigned to one of three adjuvant chemotherapy and chemoimmunotherapy treatment groups following radical or modified radical mastectomy. This study compares the efficacy of single drug treatment (melphalan) versus multiple drug regimens (CFP and CFP + BCG). In the initial phase of the project participants in the melphalan group showed a higher recurrence rate than those in the CFP and CFP + BCG groups. The recurrence rate of the melphalan group was 4.4 times higher than the recurrence rate of the combined polychemotherapy arms. However, after the initial phase, the recurrence rates for the polychemotherapy arms steadily increased and approached the dropping rate of the melphalan group. Currently (247 weeks after the beginning of the study and nine months after the last patient accrual), 194 patients have been treated (median follow-up time of 101 weeks), and no significant differences can be detected between the three treatment arms using any of the following criteria: disease-free interval, proportion of recurrence and recurrence rate. The only factors which are significant with respect to recurrence are the two prognostic factors: tumor size and degree of nodal involvement. The two chemotherapy groups, CFP and CFP + BCG, show no significant difference with respect to recurrence rate along the entire span of the study.

Antineoplastic Agents↗
PubMed1982

Malathion resistance in Tribolium strains and their hybrids: inheritance patterns and possible enzymatic mechanisms (Coleoptera, Tenebrionidae).

(1) The genetics of malathion resistance in two strains of the flour beetle, Tribolium castaneum, was investigated. In CTC-12, resistance is polygenic, while in Kano, it is due to a dominant allele at a single autosomal locus. Reciprocal hybrids with the susceptible control strains bb and pp showed an overdominant response in particular when Kano was the male parent in the original cross. (2) Three possible genetic mechanisms to explain these results are discussed. The model which best explains the genetic results, particularly the difference between the reciprocal crosses, assumes a modifier resistance allele on the Y chromosome. (3) The levels of activity of total esterases, carboxylesterases, mixed-function oxidases, epoxide hydrase, and glutathione transferase in the parent strains and their hybrids were measured quantitatively. Although total esterase activity may not be relevant for the breakdown of malathion, it was inhibited by the pesticide. The activity of the microsomal enzymes was high in CTC-12, low in bb, and intermediate in the hybrids, while carboxylesterases were very active in Kano as well as in the hybrids with bb and low in the latter. These patterns agree with the genetics of resistance in the two strains. A higher level of GSH transferase in the Kano x bb hybrids than in Kano seems to indicate a possible biochemical mechanism for their overdominant resistance.

Animals↗
PubMed1982

The specificity of Centruroides sculpturatus Ewing (Arizona lethal scorpion) hemolymph agglutinins.

C. sculpturatus sera agglutinate human erythrocytes independently of the ABO blood group, enzyme treatment, incubation temperature or sex of the scorpions. Tested with human lymphocytes and reptile and bird erythrocytes, C. sculpturatus serum reacts like an anti-sialic acid agglutinin. With leukemic lymphocytes, titers are higher than with normal lymphocytes. Mammalian erythrocytes show characteristic agglutination patterns for C. sculpturatus for Limulus polyphemus (horseshoe crab) that suggest different receptors for agglutinins of both species. Cross absorption and elution experiments indicate the presence of at least two specific agglutinins in C. sculpturatus serum. Agglutination is inhibited by N-acetylneuraminic acid and N-glycolyneuraminic acid, for all erythrocytes tested. Calcium is required for optimal activity of C. sculpturatus agglutinins. C. sculpturatus agglutinating activity is destroyed at 65% degrees C for 20 minutes. Titers are decreased by 2-mercaptoethanol, and more so after alkylation with iodoacetic acid suggesting that disulfide bonds are present in C. sculpturatus agglutinin molecules.

ABO Blood-Group System↗
PubMed1982

Saccharin preferences in prepubertal male and female rats: relationship to self-stimulation.

Saccharin preferences were studied in 48 male and female prepubertal rats (22-23 days old at the beginning of the experiment) of four genetic lines (LC1-low, LC1-high, LC2-low, and LC2-high) which differed in their inherent tendencies to self-stimulate. Sodium saccharin solutions of 0.1, 0.3, 0.5, 1, 3, 10, and 30 mM concentrations were used against water in two-bottle tests. It was found that (a) prepubertal rats prefer saccharin solutions to water, with the range of favored concentrations similar to that of adults; (b) male and female prepubertal rats do not differ as to saccharin preferences; (c) within the LC2 population, animals of the genetically high self-stimulating line prefer saccharin more than do their LC2-low counterparts; no such differentiation of the LC1 high and low lines was observed.

Animals↗