Search PubMed⌕ Search

Biomedical subjects

E Cohen

Publications and source records attributed to E Cohen.

At least 379 records · Page 21Linked to original sources
PubMed1976

Electrical properties of developing oocytes of the migratory locust, Locusta migratoria.

The electrical properties of developing nonfertilized oocytes of Locusta migratoria were studied, using intracellular microelectrodes. The inseries potential of the combined oomembrane and of the follicular cells was about 20 mV in the youngest oocytes. It increased as the oocytes developed and it reached a plateau of about 50 mV before full maturation, generally four to seven oocytes away from the fully-developed terminal oocyte. Current-voltage relations were always linear for hyperpolarizing currents. Most oocytes exhibited, however, rectification to outward current. Input resistance values varied with oocyte size from about 5 X 10(6) ohm for young oocytes to about 0.2 X 10(6) ohm for the more developed ones. Some oocytes displayed a transient depolarization on turning off a hyperpolarizing step of current. This depolarization was not correlated with the size of the oocyte or with any observed morphological feature. Any two adjacent oocytes were electrotonically coupled. A single ovariole thus represented a longitudinal chain of developing oocytes which were connected electrically. This was supported by electron microscope observations which revealed junctions partially impermeable to lanthanum and gap junctions between the follicular cells themselves and between follicular cells and oocytes. The coupling coefficient was dependent on the direction of current flow. The attenuation of voltage along an ovariole was always greater at the distal than at the proximal side.

Animals↗
PubMed1976

Thoracic duct cannulation in a patient with lung cancer.

Previously the authors demonstrated limited effectiveness of tumor specific active immunotherapy adjunct to radical surgery in patients with lung cancer. In order to improve the therapeutic effectiveness, a patient with inoperable lung carcinoma was treated with a radical surgery, tumor vaccination, and "unblocking procedures" which consisted of splenectomy and throacic duct canulation. In vitro studies demonstrated the evidence of sensitization of the patient against his own tumor, removal of blocking factor by the thoracic duct fistual from the circulation.

Adenocarcinoma, Papillary↗
PubMed1976

Generation of cytotoxic lymphocytes in vitro: response of immune rat spleen cells to a syngeneic gross virus-induced lymphoma in mixed lymphocyte-tumor culture.

Spleen cells from W/Fu rats 4 to 6 weeks after immunization with syngeneic Gross virus-induced lymphoma (C58NT)D cells usually lack detectable activity in a short-term 51Cr release assay. The results presented here demonstrate that these spleen cells retain the capacity to generate significant proliferative and cytotoxic activity upon re-exposure to mitomycin C-treated (C58NT)D cells in vitro. Optimal conditions were defined in W/Fu rats for this secondary immune response in vitro to the (C58NT)D cells. The cytotoxic response was observed to be quantitative, reproducible, and specific. Optimal generation occurred 5 days after initiation of cultures with a 30:1 responding cell:stimulating cell ratio. In vitro generated cytotoxic cells inhibit tumor growth in vivo when administered as a mixture with tumor cells.

AKR murine leukemia virus↗
PubMed1976

Antibody to carcinoembryonic antigen in hamsters bearing GW-39 human tumors.

The appearance of anti-carcinoembryonic antigen (CEA) activity in the sera of hamsters bearing i.m. heterografts of GW-39, a CEA-producing colonic tumor of human origin, was demonstrated in radioimmunoassay using radioiodinated CEA purified from GW-39. Column chromatography, sucrose gradient ultracentrifugation, and radioimmunoelectrophoresis of pooled sera from tumor-bearing hamsters showed that the CEA antibody was of the immunoglobulin M type. The CEA antibody in tumor sera contained two specificities that reacted with different determinants on the CEA. On specificity reacted with a blood group-related determinant, whereas the remaining specificity was against a unique site on the CEA. Sequential analysis of individual tumor-bearing animals revealed that an increase in tumor growth paralleled the concomitant appearance of circulating CEA and highest antibody titer, suggesting that immunoglobulin M antibody, antigen, or complexes thereof influence tumor growth in this model.

Animals↗
PubMed1976

[Indications of choice for extra-amniotic perfusion of physiologic serum].

After a preliminary report on 20 cases, we have used extra-amniotic perfusion of isotonic saline, in association or not with syntocinon, for performing:--56 2nd trimester therapeutic abortions,--16 labor inductions in interrupted 2nd and 3rd trimester pregnancies, with macerated fetus (missed abortion and missed labor). This method, relatively simple, permits the discharge of the conceptus within a reasonable time. Our experience allowed us to draw the indications of choice in the use of this method, which are the following: 1. When the amniotic puncture may be difficult (at the beginning of the 4th month or if the age of pregnancy is uncertain). 2. When there is an increased risk of hemorrhage with coagulation disorder macerated fetus or some systemic diseases). 3. When there are counter-indications for the use of hypertonic saline solution or prostaglandins (some renal, cardiac or respiratory diseases). 4. When one needs a fetus in a relatively good state for embryologic, histologic or genetic studies, which are important in case of abortion for rubella or chromosomic anomaly. In view of the innocuousness of this method, its use for labor induction in evolutive pregnancies is suggested.

Abortion, Therapeutic↗
PubMed1976

Simple modification of a liquid scintillation counter to decrease cost of and time for radioimmunoassay.

A simple, inexpensive modification in the elevator mechanism of a liquid scintillation counter allows for radioimmunoassay tubes (12 X 75 mm) containing the antibody-bound radioligand to be counted directly, thereby obviating the need for counting vials and considerably decreasing the amount of fluor used. Furthermore, because assay and counting are all done in the same tube, the modification shortens assay time and increases precision by avoiding what is often the most time consuming and inaccurate step, the transfer of antibody-bound radioligand to a counting vial. We find that use of this modification results in about a 75% decrease in the overall cost for materials and a substantial decrease in assay time.

Costs and Cost Analysis↗
PubMed1975

Epidemiology of rheumatic heart disease in black shcoolchildren of Soweto, Johannesburg.

A survey to determine the prevalence of rheumatic heart disease (R.H.D.) in Black children was conducted in the creeches and primary schools of the South Western Townships of Johannesburg (Soweto). A total of 12 050 Black children were examined by 10 cardiologists in May to October 1972. The overal prevalence rate of R.H.D. was 6.9 per 1000, with a peak rate of 19.2 per 1000 in children of the seventh school grade. The maximal age incidence was 15-18 years and there was a female preponderance of 1 6:1. A rise in prevalence occurred with increasing family size. Most children (92%) were asymptomatic, and in 82.5% R.H.D. was diagnosed for the first time during the school survey. The commonest valve lesion was mitral regurgitation, which was present in 93% and occurred as an isolated lesion in 47.5%. Lancefield's group A beta-haemolytic streptococcus was isolated from the throats of 52 per 1000 Soweto children. The auscultatory features of a non-ejection systolic click and late systolic murmur were prevalent (13.9 per 1000) and had several epidemiological factors in common with R.H.D. A comprehensive preventative campaign is urgently needed in South Africa, directed at both primary and secondary prophylaxis of R.H.D. The socioeconomic status of the community must be improved if optimal prevention is to be achieved.

Adolescent↗
PubMed1975

Beta-aminocinnamonitriles as potential antiinflammatory agents.

A number of beta-aminocinnamonitriles have been prepared by the reaction of salts of acetonitrile and propionitrile with benzonitrile. These materials were evaluated in the carrageenan antiinflammatory screen in Royal Hart, Wistar strain rats. Despite good weight gains in the parent molecule, beta-aminocinnamonitrile (1), only marginal activity was found in related compounds and some possible "metabolites."

Animals↗
PubMed1975

4-Amino-5-arylpyrimidines as antiinflammatory agents.

4-Amino-5-arylpyrimidines were synthesized by a variety of methods and have demonstrated antiinflammatory activity in the carrageenan-induced edema in the rat but displayed little activity against adjuvant-induced arthritis in rats or against uv-induced erythema in guinea pigs.

Animals↗
PubMed1975

The treatment and postoperative complications of congenital megacolon: A 25 year followup.

In 1948 one of us (O.S.) proposed a new method of treatment, abdominoperineal resection, for patients with congential megacolon. Since then, 483 patients have been treated by 13 pediatric surgeons in Chicago and Boston using this technique. Two hundred and eight-two of the patients were last interviewed and examined more than 5 years after the resection. There were 16 postoperative deaths (3.3%) and 6 late deaths (1.2%) from enterocolitis. Both early and late complications were infrequent and are discussed in detail. Almost 90% of the patients reported that they now have normal bowel habits. None of the patients developed urinary incontinence or impotence, although ten patients (2.1%) reported permanent fecal soiling. This is the first large group of patients treated for congenital megacolon who have been followed to adulthood. The low incidence of postoperative complications and minimal frequency of long-term complications indicate that the abdominoperineal resection is a safe, effective method of treatment for congenital megacolon.

Adolescent↗
PubMed1975

The effect of potassium loading on sodium excretion and plasma renin activity in Addisonian man.

Potassium has been shown to suppress plasma renin activity (PRA). This study was designed to study the role of increased aldosterone production in the mediation of such a response. Five patients with adrenal insufficiency were placed on a diet of 60 meq potassium and 100-150 meq of sodium while receiving a constant amount of cortisone acetate and Florinef. Upright PRA was determined each day for 2-3 days in the control period and then for 3-4 days after potassium intake had been increased to 200-300 meq/day. Potassium loading induced a natriuresis. Hence, patients were either sodium replaced (six studies in four patients) or allowed to become sodium depleted (three patients). Potassium loading without replacement was associated with a decrease in weight, negative sodium balance, hyperkalemia, and a positive potassium balance. PRA rose during the experimental period. Potassium loading with sodium replacement was associated with little change in weight or sodium balance. Hyperkalemia and positive potassium balance were present to the same degree as found in the studies without sodium replacement. When all PRA values are considered (both morning and evening values) there was no significant change with potassium loading (+ 1.31 ng/ml per h; range + 6.9 to -2.0). We conclude that hyperkalemia or a positive potassium balance did not suppress PRA in Addisonian man in these studies when sodium balance was maintained, nor did it prevent a rise in PRA when sodium balance was negative.

Addison Disease↗