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Biomedical subjects

H Cohen

Publications and source records attributed to H Cohen.

At least 505 records · Page 28Linked to original sources

Therapeutic trials with oral colchicine in psoriasis.

Twenty-two psoriatic patients were treated orally with the antichemotactic agent, colchicine, at a dosage of 0.02 mg per kg per day for a duration of 2-4 months. Complete clearing or marked improvement were noted in 8 of the 9 patients, in whom thin papules and thin plaques were the predominant type of lesion. Much less favorable results were obtained in patients with chronic, stable, thick plaque-type disease, although decreased scaliness, erythema and infiltration and marked diminution of the pruritus were observed in almost all of the cases. A considerable improvement of the joint pains was noted in each of the 8 patients who suffered from arthralgias. Five additional patients with extensive, chronic, stable plaque-type psoriasis were given oral colchicine immediately after complete clearing of their skin lesions with Goeckerman's method or with methotrexate. Four of them continued to take colchicine for 8-9 months and during that time they remained free of significant skin disease. These findings lend support to the hypothesis that the migration of the activated psoriatic neutrophils into the skin could be an important factor in the initiation and possibly also in the perpetuation of the psoriatic lesions. Closely controlled, long-term studies conducted in large numbers of patients are warranted in order to determine the exact therapeutic role of oral colchicine in the long-term management of psoriasis.

Administration, Oral↗

High pressure liquid chromatographic determination of vitamin D3 in instant nonfat dried milk.

Vitamin D3 was determined in commercially fortified instant nonfat dried milk by using normal phase high pressure liquid chromatography (HPLC). The sample was extracted with dichloromethane with sodium phosphate tribasic solution added. The sample was cleaned up by using a Sep-Pak silica cartridge and then a microparticulate column containing 10 micrometer Partisil-10 PAC packing material. The final analysis was performed by using a normal phase HPLC system with 10 micrometer LiChrosorb NH2 column. Recovery of vitamin D3 at levels as low as 10000 IU/kg was 97.7% with a standard deviation of 3.9%.

Animals↗

Sephadex LH-20 cleanup, high pressure liquid chromatographic assay, and fluorescence detection of zearalenone in animal feeds.

A high pressure liquid chromatographic (HPLC) method is described to determine zearalenone in animal feeds at levels as low as 0.01 ppm. Samples are extracted with chloroform-ethanol and initially purified using a SEP-PAK silica cartridge, followed by column chromatography using Sephadex LH-20. Separation by normal phase HPLC is followed by fluorescence detection. Recoveries at levels of 1.0-0.01 ppm averaged greater than 90%. Confirmation included HPLC analysis of the sample and a zearalenone standard, using 3 different excitation wavelengths, and comparison of fluorescence responses obtained. The method was successfully applied to the analysis of 1 corn and 3 cornmeal samples. Zearalenone was detected in all 4 samples at levels of 0.379-19.2 ppm.

Animal Feed↗

Coexistence of IgA myeloma and Gaucher's disease.

An elderly woman of Ashkenazic Jewish descent, who had had adult Gaucher's disease diagnosed seven years previously, was found to have IgA myeloma. The diagnosis of IgA myeloma was confirmed by the presence of lytic lesions in the skull and long bones, atypical plasma cells in bone marrow, and monoclonal elevation of IgA, kappa-type. In addition, the marrow contained Gaucher's cells. A causal relationship between these two pathologic entities remains speculative.

Aged↗

Determination of vitamin E in animal feeds by normal phase high pressure liquid chromatography.

A simple and rapid quantitative method for the determination of vitamin E in animal feeds is described. The method involves direct extraction with a mixture of isooctane--1,4-dioxane (80 + 20) followed by saponification. Additional purification was achieved by using a silica gel Sep-Pak. Elution time for vitamin E alcohol was 7.98 min (standard deviation (SD) 0.06) using a Partisil-10 PAC column and an isocratic mobile phase of hexane--dichloromethane--isopropanol (70 + 30 + 0.2) with a flow rate of 1 mL/min, and detection at 292 nm and 0.01 AUFS by a variable UV monitor. The average recovery of vitamin E was 96.64% (SD 5.19) in 4 different animal feeds. The method compared favorably with the official AOAC method. The minimum detectable amount of vitamin E in an animal feed is 10 IU/kg.

Animal Feed↗

Corticotropin regulation of the synthesis of a specific rat adrenal cytosolic protein. Effects of hypophysectomy and actinomycin D.

The mechanism of corticotropin stimulation of the synthesis of a specific rat adrenal cytosolic protein was investigated. This protein (protein E) has a mol.wt. of approx. 30000. It is detected by polyacrylamide-gel electrophoresis of cytosol prepared from adrenal slices from rats treated with corticotropin in vivo and control rats, the slices being incubated with [(3)H]- and [(14)C]-leucine respectively. In rats 1-15 days after hypophysectomy, corticotropin, like dibutyryl cyclic AMP, induces an increase in protein E similar to that induced in control rats, even though both compounds no longer stimulate total protein synthesis. Corticotropin stimulation of protein E synthesis is mediated by cyclic AMP but not by corticosterone, since aminoglutethimide, a steroidogenic inhibitor, does not affect corticotropin stimulation, and dexamethasone alone has no effect. Actinomycin D, when injected in vivo 1h before or after corticotropin injection, prevents the effect of corticotropin on protein E synthesis, which is interpreted as evidence that mRNA synthesis is necessary for the stimulation of protein E synthesis. When injected more than 2h after corticotropin, actinomycin D does not prevent corticotropin stimulation of protein E synthesis, but completely blocks corticotropin stimulation of total protein synthesis. This is interpreted as meaning that, after stimulation of mRNA coding for protein E, corticotropin has no effect on the synthesis of protein E. On the other hand, corticotropin stimulation of protein E synthesis persists after hypophysectomy even though it no longer stimulates total protein synthesis. These data suggest that the factor(s) involved in the synthesis of protein E are more stable than those involved in total protein synthesis.

Adrenal Glands↗

Pseudo atrioventricular block.

Pseudo first- and second-degree atrioventricular (AV) block can occur due to depressive effects of concealed junctional discharges on AV conduction of sinus impulses. Pseudo AV block is not indicative of a primary impairment of AV conduction and is reversible by interventions that suppress ectopy.

Electrocardiography↗

Submitral calcification or sclerosis in elderly patients: M mode and two dimensional echocardiography in "mitral anulus calcification".

Submitral calcification or sclerosis was visualized with M mode echocardiography in 84 elderly patients, 35 of whom were also studied with two dimensional echocardiography. Posterior submitral calcification, commonly referred to as "mitral anulus calcification," was present in 82 patients and was located in the angle between the posterior mitral leaflet and left ventricular posterior wall, rather than in the mitral anulus proper. M mode scans from the left ventricle to the left atrium showed that posterior submitral calcification ended abruptly in 66 cases, and in these it became contiguous with the posterior atrioventricular junction (true mitral anulus) in only 14 instances, in 16 patients the posterior submitral calcification sloped anteriorly to merge with the posterior aortic root. Anterior submitral calcification was visualized in 12 patients, 10 of whom also had posterior submitral calcification. Anterior submitral calcification was usually located immediately anterior to the base of the anterior mitral cusp. In two cases, if appeared to arise in the region between the aortic and mitral rings; in one instance, it was located in the mid left ventricle, in the mitral chordal region. We suggest that the terms anterior and posterior submitral calcification are more appropriate than "mitral anulus calcification" because in most cases such calcific deposits do not appear to be located in or to arise from the true mitral anulus.

Age Factors↗

Potency measurement of pertussis vaccines and consistency in production.

If one accepts the minimum requirement of 4 i.u. shd-1 for the potency of pertussis vaccine--and there is no convincing evidence to reject this--the usual MPT with 20 mice per dilution offers a sufficient guarantee that no vaccines with too low potency will be accepted, provided that the consistency in production has been sufficiently proven. As higher concentrations than necessary should be avoided in view of the undesirable side-effects, the establishment of requirements for the lower level of the 95% confidence limits might, however, entail exactly this risk.

Animals↗

Production of choriogonadotropin-like factor by a microorganism.

Extracts from an acetone powder preparation of a culture of a microorganism tentatively named Progenitor cryptocides contain choriogonadotropin (CG)-like factor as determined by radioimmunoassay with antiserum to human (h)CG beta subunit COOH-terminal peptide and radioreceptor assay with bovine corpus luteum membranes. Possible interference by proteases in the extracts was excluded. Immunoreactive materials reacting with antisera to hCG beta subunit and hCG beta subunit COOH-terminal peptide were also found in the extracts. No free alpha subunit was detected. The CG-like factor was purified by chromatography on Sephadex G-100, concanavalin A-Sepharose, and DEAE-Sephadex A-50. The factor was adsorbed by concanavalin A-Sepharose, suggesting that it contains mannose and glucose moieties. The factor was eluted at the same position as standard hCG on Sephadex G-100. It dissociated into two bands when subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis; the bands corresponded to the respective standard hCG subunits. The biological activity of the purified factor as determined by the rat uterine weight assay and the ovarian weight assay was equivalent to 380 (95% confidence limits: 320-490) and 880 (780-1020) international units/mg, respectively. It can be concluded from the present results that a microorganism produces a glycoprotein that is biologically active and has physicochemical properties similar to those of hCG.

Bacteria↗

Quantitative analysis of vitamin D3 in a feed using normal phase high pressure liquid chromatography.

A procedure is described for the separation and quantification of Vitamin D3 from different feeds and premixes. The study was conducted, first using a liquid partition step as a preliminary clean-up after extraction, then chromatography on activated Silica gel 60 before final analysis on a high pressure liquid chromatograph (HPLC) using a LiChrosorb NH2 (10 mu) column and a variable wavelength UV detector set at 264 nm. Total analysis on the HPLC was achieved in fifteen minutes. The detector response curve for an authentic D3 standard was linear using peak areas with a minimum detectable amount being 5 ng. The overall percent recovery of D3 in feeds was 94.4 +/- 2.4%. The minimum detectable amount of D3 in animal feeds was found to be in the region of 2,000 I.U./kg.

Animal Feed↗