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Biomedical subjects

A Cohen

Publications and source records attributed to A Cohen.

At least 757 records · Page 42Linked to original sources
PubMed1985

The effect of an advanced cardiac life support course on advanced cardiac life support ability.

Thousands of health care providers spend time, money, and energy each year taking the AHA-sponsored ACLS courses, and ACLS-certified health care providers are frequently given greater job responsibility than other health care providers in the same setting. The purpose of this study was to determine the effect of an ACLS course on the ability of health care providers to perform ACLS in a simulated situation. A nonequivalent control group design was used. The sample consisted of 76 health care providers whose job responsibilities included ACLS. The Mega-Code skill station from the ACLS course was used to evaluate ACLS performance. Chi-square analyses showed a significant (p less than 0.05) difference in the posttest pass/fail results of the two groups and a significant (p less than 0.05) difference in the changes from pretest to posttest of the two groups. The research hypotheses were supported, and the researches concluded that the course had a positive effect on the subjects' ACLS ability.

Clinical Competence↗
PubMed1985

Conversion from cyclosporine to azathioprine in renal graft recipients.

Only one of six patients in whom a clinical diagnosis of rejection was confirmed by both biopsy and FNA benefited from a switch from cyclosporine to azathioprine. Nine patients, in whom nephrotoxicity and rejection could not be separated and in whom the biopsy was positive but the FNA negative, improved when converted to cyclosporine. This improvement was, however, followed by subsequent rejection episodes in four of these patients. This study suggests caution in changing from CsA therapy in patients with unstable function.

Azathioprine↗
PubMed1985

Botulism intoxication after surgery in the gut.

Botulism intoxication is described in a 45-year-old woman who was hospitalized with symptoms suggesting an intestinal obstruction. At intervention a 20-cm length of necrotic small intestine was excised and prophylactic antibiotics were given. Five days after surgery--during which time the patient was fed only parenterally--dryness of the mouth, difficulty in swallowing, general weakness, and difficulty with speech and in keeping her eyes open were noted. The patient was alert and well oriented. The clinical symptoms and the electrophysiological studies suggested the diagnosis of botulism. A serum sample caused death in mice upon inoculation and two samples of feces were positive for the presence of Clostridium botulinum organisms. Supportive treatment with botulinum antitoxin was given and the patient was discharged in good condition.

Anti-Bacterial Agents↗
PubMed1985

High frequency needle dissection rhytidectomy.

Fifty consecutive rhytidectomies were performed utilizing high frequency needle dissection on one side and standard sharp dissection on the other for all incisions and flap elevation. The efficacy of this technique in hemostasis, prevention of hematoma, and wound healing is compared to the conventional technique of rhytidectomy. The advantages and disadvantages of the modality are discussed.

Ambulatory Surgical Procedures↗
PubMed1985

Primary human marrow cultures for erythroid bursts in a serum-substituted system.

To determine environmental requirements for erythroid burst formation in primary culture, we added human bone marrow cells to serum-depleted methylcellulose, agar, or fibrin clot cultures. Optimal BFU-E proliferation was present in cultures prepared with Iscove's modified Dulbecco medium, 248 micrograms/ml transferrin, 1.63 micrograms/ml ferric chloride, 117 micrograms/ml bovine serum albumin, and each of seven preparations of erythropoietin. Burst number was comparable to that in serum containing culture. Reducing sodium dodecyl sulfate electrophoresis of commercial albumin preparations showed them to contain abundant lipoproteins. Results of experiments with human plasma albumin found to be greater than 98% pure by one- and two-dimensional gel electrophoresis and delipidated albumin indicate that an albumin source is needed for burst formation to occur. Together with albumin, exogenous phosphatidylcholine but not phosphatidylserine augmented burst number. Bursts routinely appeared in serum-depleted culture without added burst-promoting activity (BPA). However, leukocyte-conditioned medium (LCM) and its high-speed supernatant and pellet fractions enhanced burst formation. Antimembrane IgG capable of neutralizing BPA reduced burst number to a level below that achieved in LCM-depleted culture, suggesting that endogenous BPA was inactivated. We conclude that human marrow BFU-E proliferation requires iron-saturated transferrin, albumin, and erythropoietin. Exogenous BPA and phospholipids enhance but are not essential for burst formation to proceed in primary culture.

Blood↗
PubMed1985

[Homosexuality].

Explore the source record for details and available documents.

Female↗
PubMed1985

[Study of the peptide hormones of the hypothalamo-postpituitary system of the dromedary, Camelus dromedarius, (Camelidae, Mammalia) of Tunisia].

Ocytocin and vasopressin are two nonapeptides of the hypo thalamo-Post-hypophysary system. They are isolated and purified from dromedary post-hyphophysis, freshly collected in the meat centers of the south of Tunisia. The use of three chromatographies steps were found to be essential in obtaining high Pure hormones. These steps cousist in a sephadex G25 gel filtration and two successive High performance liquid chromatographies: H.P.L.C. The analysis of the two hormones by thin layer chromatography and Radioimmunoassays, and the identification of the amino-acid composition demonstrate that camel vasopressin is a 8 arginin vasopressin but ocytocin is identic to the other hormones isolated from different animal species.

Amino Acids↗
PubMed1984

Evidence for distinct catabolic pathways of adenine ribonucleotides and deoxyribonucleotides in human T lymphoblastoid cells.

The catabolisms of deoxy-ATP and ATP were compared in cultured human T lymphoblastoid cells incubated under various conditions. It was found that in the presence of deoxycoformycin, an inhibitor of adenosine deaminase, deoxyadenosine was the only product of deoxy-ATP catabolism. In contrast, the main products of ATP catabolism in either the presence or the absence of deoxycoformycin were inosine and hypoxanthine. These results demonstrate that deoxy-ATP catabolism proceeds exclusively via deoxyadenosine deamination, whereas ATP catabolism proceeds mainly via adenylate deamination. These findings thus provide an explanation for the selective deoxynucleotide metabolic abnormalities associated with adenosine deaminase deficiency in humans.

Adenosine↗
PubMed1984

Impaired osmoregulation at high altitude. Studies on Mt Everest.

Osmoregulation was studied in 13 mountaineers who had experienced long-term exposure to high altitude on Mt Everest. Serum osmolality rose from 290 +/- 1 mOsm/kg to 295 +/- 2 mOsm/kg at 5,400 m and finally to 302 +/- 4 mOsm/kg at 6,300 m after a mean of 26.5 days above 5,400 m. Despite this degree of osmoconcentration, plasma arginine-vasopressin concentration remained unchanged: 1.1 +/-0.1 microU/mL at sea level, 0.8 +/- 0.1 microU/mL at 5,400 m, and 0.9 +/- 0.1 microU/mL at 6,300 m. Urinary vasopressin excretion was also similar at all three altitudes. We conclude that prolonged exposure to high altitude may result in persistent impairment of osmoregulation, caused in part by an inappropriate arginine-vasopressin response to hyperosmolality.

Altitude↗
PubMed1984

Nucleotide catabolism and nucleoside cycles in human thymocytes. Role of orthophosphate.

The catabolism of GTP and ATP in intact human thymocytes was studied, and the effect of intracellular Pi concentrations on various catabolic reactions was evaluated. Induction of nucleotide catabolism was performed with either NaN3 or deoxyglucose. NaN3 induced an increase in intracellular Pi, whereas deoxyglucose induced a decrease in Pi in human thymocytes. At elevated Pi concentrations, an intracellular accumulation of GMP, IMP and AMP was observed, and the entry of these nucleotides into the nucleoside cycles was diminished. In contrast, at lowered Pi concentrations, there was no accumulation of nucleoside monophosphates, but the production of purine bases and nucleosides was increased as a result of enhanced nucleotide entry into the nucleoside cycles. The dephosphorylation of nucleotides thus seems to be regulated by intracellular Pi concentrations. ATP catabolism proceeded mainly via adenylate deamination at both elevated and lowered Pi concentrations. Guanylate formed during GTP catabolism was mainly dephosphorylated, but significant amounts of GMP were also deaminated to yield IMP.

Adenosine Triphosphate↗
PubMed1984

Experimental models for gastric leiomyosarcoma. The effects of N-methyl-N'-nitro-N-nitrosoguanidine in combination with stress, aspirin, or sodium taurocholate.

A series of experiments was devised to determine possible modifying effects of stress, aspirin, and sodium taurocholate on the activity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the Buffalo rat stomach. MNNG is a well known, direct-reacting carcinogen, and has been a reliable agent for the experimental production of gastric adenocarcinoma. The authors were able to produce adenocarcinomas in rats, but found a great number of gastric leiomyosarcomas. These occurred only in the groups given MNNG in combination with stress, aspirin, or sodium taurocholate, and did not occur in experimental groups given either MNNG, stress, aspirin, or sodium taurocholate alone, and did not occur in the control group.

Adenocarcinoma↗
PubMed1984

The effect of interferon on cells deficient in nucleoside transport or lacking thymidine kinase activity.

Mutants of mouse T-lymphoma S49 cells lacking thymidine kinase activity or deficient in nucleoside transport were selected by growth in the presence of 5'-fluorodeoxyuridine and their sensitivity to interferon tested. All five thymidine kinase and both transport deficient mutants were sensitive to the antiproliferative effects of interferon. The replication of encephalomyocarditis virus was also inhibited by interferon, and the intracellular levels of (2'-5')oligo-adenylate synthetase were elevated in all mutants tested. These results suggest that an intact nucleoside transport system or thymidine kinase activity are not essential for the expression of interferon sensitivity in these cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1984

Guanosine triphosphate catabolism in purine nucleoside phosphorylase deficient human B lymphoblastoid cells.

GTP catabolism induced by sodium azide or deoxyglucose was studied in purine nucleoside phosphorylase (PNP) deficient human B lymphoblastoid cells. In PNP deficient cells, as in control cells, guanylate was both dephosphorylated and deaminated but dephosphorylation was the major pathway. Only nucleosides were excreted during GTP catabolism by PNP deficient cells and the main product was guanosine. The level of nucleoside excretion was largely affected by intracellular orthophosphate (Pi) level. In contrast, normal cells excreted nucleosides only at low Pi level while at high Pi levels, purine bases (guanine and hypoxanthine) were exclusively excreted. PNP deficiency had no effect on the extent of GMP deamination.

Azides↗