Search PubMed⌕ Search

Biomedical subjects

H Cohen

Publications and source records attributed to H Cohen.

At least 487 records · Page 27Linked to original sources
PubMed1982

Induction (or stimulation) of prolactin and growth hormone production in a rat pituitary tumor cell line by bromodeoxyuridine.

Under basal conditions, a rat pituitary tumor cell line (C8 11RAP) does not secrete any detectable PrL, FSH, and LH, and secretes only minute amounts of GH (27.1 +/- 0.5 ng/10(6) cells.24 h), as evaluated by RIA. Bromodeoxyuridine (BrdUrd) added to the culture medium induced the accumulation of PRL into cells and medium, increased that of GH, but did not induce that of LH or FSH. The amount of radioimmunoassayable PRL and GH accumulated in the medium increased after a lag period of 15 days and was drug concentration dependent. Maximal accumulation was 232.9 +/- 36.8 and 493.6 +/- 41.5 ng/10(6) cells.24 h for PRL and GH, respectively, at 50 micrograms/ml BrdUrd. In the presence of BrdUrd (greater than or equal to 20 micrograms/ml), the cells grew more slowly and were more strongly attached to the flasks. All of the effects induced by BrdUrd were reversible. PRL and GH were characterized by three methods; 1) radiocompetition with increasing dilution of samples; 2) Sephadex chromatography, followed by RIAs; and 3) sodium dodecyl sulfate-polyacrylamide gel electrophoresis done on the immunoprecipitate of the proteins secreted by cells incubated with [3H]leucine. Chronic treatment with TRH (3 X 10(-6) M) of cells grown without BrdUrd was unable to increase the production of GH or to induce that of PRL. On the other hand, after the same treatment of cells cultured in the presence of BrdUrd, the amounts of PRL accumulated in the culture medium or cells were increased 2- to 7-fold over unstimulated levels; under the same conditions, GH accumulation in the medium was also increased, but this augmentation was less than that of PRL. These results indicate that BrdUrd simultaneously induces or stimulates the production of PRL and GH in C8 11RAP cells, and that TRH increases the production of both hormones only in BrdUrd-treated cells.

Animals↗
PubMed1982

Capillary gas-liquid chromatographic determination of vomitoxin in cereal grains.

A gas-liquid chromatographic (GLC) method, using an electron capture detector, is described for determining vomitoxin in cereal grains at levels as low as 0.05 ppm. Samples are extracted with chloroform-ethanol and initially purified by using a Sep-Pak silica cartridge, followed by column chromatography using Sephadex LH-20. Additional purification is achieved by using a disposable cyano cartridge. Heptafluorobutyrylimidazole (HFBI) is added to form esters of the analytes. The HFB esters of vomitoxin are separated on a 30 m X 0.25 mm fused silica column coated with SE-54 and measured with a 63Ni electron capture detector. Samples were confirmed by gas-liquid chromatography/mass spectrometry using electron impact ionization and single ion monitoring at the molecular ion mass of 884.05 and at 10 000 resolving power. The method has been applied to wheat, oats, barley, and corn. The limit of detection is 0.05 ppm vomitoxin. Average recoveries were 89.8% with a coefficient of variation of 4.0%.

Chromatography, Gas↗
PubMed1981

Congestive heart failure due to adriamycin cardiotoxicity: its natural history in children.

The congestive heart failure (CHF) associated with Adriamycin cardiotoxicity is frequently fatal. To investigate the course of Adriamycin-induced congestive heart failure, all Adriamycin-treated children who developed congestive heart failure at the Children's Hospital Medical Center and Sidney Farber Cancer Institute were studied. Criteria for Adriamycin-induced congestive heart failure included clinical evidence of left ventricular (LV) failure and echocardiographic evidence of abnormal left ventricular function. Fifteen children fulfilled these criteria. Eleven patients received between 400 and 500 mg/m2 of Adriamycin; four patients received cumulative doses over 500 mg/m2. Twelve of 15 (80%) children survived their acute episode of congestive heart failure. At follow-up, three patients had normalized their echocardiographic parameters of left ventricular function, three had died of their malignancies with compensated cardiac function until death, and six were clinically asymptomatic despite persistence of abnormal LV function on echocardiogram. Only three patients died of Adriamycin cardiomyopathy. In children treated with aggressive medical therapy, congestive heart failure secondary to Adriamycin cardiotoxicity may be reversible in certain cases.

Adolescent↗
PubMed1981

Pancreatitis, child abuse, and skeletal lesions.

A case of pancreatitis associated with trauma of child abuse is reported. Skeletal changes secondary to pancreatitis developed and the distribution of the bony lesions included both metaphyseal and epiphyseal growth centers. The coexistence of pancreatitis, child abuse, and subsequent skeletal lesions is again emphasized, as well as the unique occurrence of lesions in the epiphyseal centers.

Acute Disease↗
PubMed1981

Theoretical and practical considerations in the application of killed poliovirus vaccine for the control of paralytic poliomyelitis.

This paper contains a summary of the principles upon which the preparation and use of killed poliovirus vaccine (KPV) are based, as well as a summary of earlier and more recent work suggesting the feasibility of formulating a KPV preparation that would be fully and durably effective in a one- or two-dose regimen. The essential factor in the preparation of such a vaccine is the inclusion of a sufficient mass of the immunizing antigen, for each of the three antigenic types of poliovirus, to induce the formation of humoral antibody and/or immunologic memory after the first dose. The results of a series of studies carried out in West African and Scandinavian countries are summarized, which suggest that such a vaccine should contain 40, 8, and 32 D-antigen units for types I, II and III, respectively. If the D-antigen unit measurement is to be used as a guide to KPV standardization, the details of the method of manufacture are important; in this regard, the method of vaccine preparation used at the Rijks Instituut voor de Volksgezondheid should serve as a reference standard for the preparation of vaccines expected to produce the effects described.

Antibody Formation↗
PubMed1981

Induction of lymphomas in mice by busulfan and chloramphenicol.

Busulfan causes long-lasting defects in the hematopoietic stem cells and in the immune system of mice. We designed studies to determine whether chloramphenicol further damaged the already defective hematopoietic stem cells of mice that were pretreated with busulfan, and we unexpectedly observed that mice given injections of the combination of busulfan and chloramphenicol developed lymphomas in relatively high incidence. The disease is invariably associated with splenomegaly and enlargement of the thymus. Leukocytosis with lymphoblasts in the peripheral blood occurred in some affected mice. The malignant cell is a lymphoblast of thymic origin. Thirteen of 37 mice which received both busulfan and chloramphenicol developed lymphomas. An additional five of the remaining 24 mice without proven lymphoma died and were not autopsied. Twelve of the 13 proven lymphomas developed within 280 days from the start of the experiment. Four of the 35 mice treated with busulfan alone developed lymphomas, and an additional five of the remaining 31 died but were not autopsied. Two of 41 mice treated with only chloramphenicol developed lymphomas. Of the mice treated with either busulfan or chloramphenicol alone that developed lymphomas, all did so more than 280 days from the start of the experiment. None of the control mice developed lymphoma. We conclude that both busulfan and chloramphenicol may induced lymphomas in mice that are not known to develop them spontaneously. The combination of both busulfan and chloramphenicol increased the frequency and accelerated the onset of the disease.

Animals↗
PubMed1981

High pressure liquid chromatographic determination and fluorescence detection of aflatoxins in corn and dairy feeds.

A high pressure liquid chromatographic (HPLC) method is described for the determination of aflatoxins B1, B2, G1, and G2 in animal feeds at levels as low as 2.5 ppb. Samples are extracted with acetonitrile-water and initially purified by using a Sep-Pak silica cartridge. The aflatoxins are then reacted with trifluoracetic acid and acetonitrile-water (1 + 1). After filtration, the aflatoxins are completely resolved on a 10 micrometer C18 column using a radial compression separation system with an acetonitrile-water solvent system. Aflatoxins G2a, B2a, G2, and B2 were reported in less than 30 min, using fluorescence detection. The method was successfully applied to samples at levels of 20-2.5 ppb added aflatoxins with recoveries in the range of 82-99%.

Aflatoxins↗
PubMed1981

[Conjunctival ocular myosis (Oesterus ovis) about 3 cases (author's transl)].

Conjunctival lesions are the most frequent expression of ocular myiasis encountered in the Mediterranean region. Presenting typically with inflamed and oedematous eyes, and superficial corneal erosions, these affections are rarely diagnosed as they are excluded from the differential diagnosis. Early, adequate treatment will prevent major complications.

Adult↗
PubMed1980

Endometrial carcinoma after Hodgkin disease in childhood.

A 34-year-old patient developed metastic endometrial carcinoma after Hodgkin disease in childhood. She had ovarian failure after abdominal irradiation and chemotherapy for Hodgkin disease, and received exogenous estrogens, a treatment implicated in the development of endometrial cancer in menopausal women. Young women on replacement estrogens for ovarian failure after cancer therapy may also have increased risk of endometrial carcinoma and should be examined periodically.

Adenocarcinoma↗
PubMed1980

Lumbar epidural anaesthesia and sensory profiles in term pregnant patients.

Sensory profiles of lumbar epidural anaesthesia were studied in 57 patients, during active labour. The local anaesthetics used were chloroprocaine three per cent with and without epinephrine, chloroprocaine two per cent, bupivacaine 0.25 per cent and a mixture of chloroprocaine three per cent and bupivacaine 0.5 per cent. A common pattern of spread was found for all local anaesthetic solutions with the onset of the block affecting the dermatomes innervated by the thinnest nerve roots (T12L1). There was a percentage of failure to block the thickest nerve root (S1). Inguinal and suprapubic discomfort ("missing segment") occurred when S1 was not blocked. Under the conditions of this experiment, the addition of bupivacaine to chloroprocaine did not increase the duration of the blockade significantly.

Anesthesia, Epidural↗