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PubMed1982

Lymphocyte abnormality in human myotonic dystrophy and experimental drug-induced myotonia.

In the cytoplasm of peripheral blood lymphocytes in 3 of 13 patients with myotonic dystrophy, myelin-like structures were observed electronmicroscopically. Some were connected to the cytoplasmic membranes, and some were surrounded by a limiting membrane possessing acid phosphatase activity. These findings suggest an aberration of cytoplasmic membranes in lymphocytes. Similar structures had appeared in lymphocytes of normal rats that became myotonic with 20, 25-diazacholesterol. These findings suggest that a primary genetic defect in human myotonic dystrophy, which participates in the formation of myelin-like structures in lymphocytes, might be also responsible for the occurrence of a myotonic phenomenon.

Adolescent↗
PubMed1987

Neurologic complications after gastric restriction surgery for morbid obesity.

We report the occurrence of neurologic complications in 23 patients who underwent gastric restriction surgery for the treatment of morbid obesity. Complications occurred 3 to 20 months after surgery. All the patients had had protracted vomiting for the first 3 months after the operation. The following syndromes were found: chronic or subacute symmetric polyneuropathy (12 patients), acute severe polyneuropathy (1 patient), burning feet syndrome (2 patients), meralgia paresthetica (3 patients), myotonic syndrome (1 patient), posterolateral myelopathy (2 patients), and Wernicke-Korsakoff encephalopathy (2 patients). The patients suffering from burning feet syndrome and those with Wernicke-Korsakoff encephalopathy showed a clear improvement after parenteral thiamine treatment. As to the rest of the patients, the occurrence of the complications seems to be linked to nutritional causes, although no such deficiencies were detected.

Adult↗
PubMed1981

Effects of steroid blockers on LH-induced ovulation in the domestic fowl, Gallus domesticus.

The spontaneous ovulation of hens was suppressed by daily injection of PMSG. The LH injected to overcome the block was accompanied by one of 4 compounds known to inhibit steroidogenesis at different sites in the biosynthetic pathway. A dose of 300 mg aminoglutethimide phosphate, which inhibits the conversion of cholesterol to 20 alpha-hydroxycholesterol, blocked the LH-induced ovulation and prevented the normal rise in plasma progesterone. Metyrapone, an inhibitor of 11 beta-hydroxylase, and SC 12937 and AY 9944, inhibitors of cholesterol synthesis, did not prevent ovulation or the progesterone rise induced by exogenous LH. Administration of progesterone overcame the inhibitory effect of aminoglutethimide, and it is suggested that progesterone is involved in the ovulatory process of the fowl.

Aminoglutethimide↗
PubMedDate not supplied

Determination of DiazaCon in quail feed and quail serum by ion pair reversed-phase chromatography.

Liquid chromatographic (LC) methods were developed for quantitating the potential avian contraceptive DiazaCon in quail feed and serum. DiazaCon was extracted from ground quail feed with basic n-butyl chloride. The n-butyl chloride extract was evaporated to dryness. The DiazaCon residues were dissolved in an aqueous methanolic ion pairing solution and quantitated by LC at 206 nm. Avian sera was combined with an equal volume of a pH 4 aqueous solution of ion pairing reagent and filtered to remove interfering proteins. DiazaCon was quantitated by LC. Mean recoveries for 500 and 2000 ppm fortified feed were 89.1 and 91.0%, respectively. The mean recovery for sera fortified at 5 levels ranging from 35 to 2000 ppm was 84.9%. Method limits of detection were approximately 14 and 13 ppm for feed and sera, respectively.

Animal Feed↗
PubMed1965

Myotonia and keratoderma induced by 20,25 diazacholestenol.

A new inhibitor of cholesterol synthesis, 20,25 diazachlestenol, produced myotonia in 31 persons; and, in six of these, a keratoderma which resembles the natural disease, keratoderma climactericum. These observations further emphasize the importance of normal lipid synthesis in orderly cornification.

Azacosterol↗
PubMedDate not supplied

Effect of 22,25-diazacholesterol dihydrochloride on the spermatogenesis of a wild rat, Bandicota bengalensis.

The effects of 22,25-diazacholesterol dihydrochloride (SC-12937) on the spermatogenesis of the bandicoot rat (Bandicota bengalenesis), heretofore unreported on any mammalian species, were studied. Rats were given a single subcutaneous injection of SC-12937 at a dosage of 100 or 200 mg/kg body weight and were killed on days 2 or 10 post-injection. Quantitative analysis of the germinal epithelium was performed on testicular sections (5 micron) stained with periodic acid-Schiff-hematoxylin to assess spermatogenesis. Treatment with SC-12937 at both dosages was found to interfere with the spermatogenic process of this pest rat. In addition to its antispermatogenic action, at higher dosage (200 mg/kg), this compound produced a marked suppression in accessory organ function. The results indicate that a single administration of SC-12937 in low dosage can cause spermatogenic inhibition without affecting accessory organ function in the bandicoot rat.

Animals↗
PubMed1987

The effect of 3-methylcholanthrene on postlanosterol cholesterol biosynthetic pathways in mouse skin.

Repeated topical application of 3-methylcholanthrene to the backs of BALB/c mice lowered the tissue levels of lathosterol and provitamin D3, intermediates in one of the cholesterol biosynthetic pathways (the delta 7 pathway), though the activities of lathosterol 5-desaturase and provitamin D3 7-reductase were similar to those of control animals. These results seemed to indicate that carcinogen treatment exerted a depressive effect at some earlier step(s) than lathosterol synthesis. However, the content of cholesterol in mouse skin was not lowered in these animals, suggesting that another biosynthetic pathway might be activated. When diazacholesterol, which is known to inhibit the conversion of desmosterol to cholesterol, was administered together with the carcinogen, a marked accumulation of desmosterol was observed compared to animals given only diazacholesterol. Since desmosterol is an intermediate in the pathway in which the delta 24 double bond is reduced at the final step (the delta 24 pathway), this seemed to suggest that the delta 24 pathway was activated by carcinogen treatment.

Administration, Topical↗
PubMed1988

Alteration of cholesterol biosynthetic pathways in the skin of mice administered polycyclic aromatic hydrocarbons.

When polycyclic aromatic hydrocarbons were applied solely or together with a tumor promoter (12-O-tetradecanoylphorbol-13-acetate) to the skin of mice, a marked decrease in the level of lathosterol was observed, reflecting a significant change in the metabolism of sterols. Yet the total amount of cholesterol was not changed. When diazacholesterol (a metabolic inhibitor) was administered to mice, both desmosterol and 5 alpha-cholesta-7,24-dien-3 beta-ol accumulated in the skin, whereas the level of lathosterol decreased. These results seem to suggest that a significant portion of lathosterol is formed via 5 alpha-cholesta-7,24-dien-3 beta-ol in addition to the pathway through methostenol. When polycyclic aromatic hydrocarbon was applied to the skin of the mouse treated with diazacholesterol, a significant increase of desmosterol and a marked drop of the level of 5 alpha-cholesta-7,24-dien-3 beta-ol were observed. These results strongly suggest that polycyclic aromatic hydrocarbons perturb the metabolism of sterol in the skin of mice while keeping the total amount of cholesterol unchanged. A similar metabolism also seems to be operating in tumor tissue itself.

Animals↗
PubMed1984

Diazacholesterol-induced ichthyosis in the hairless mouse. Assay for comparative potency of topical retinoids.

Although the new synthetic retinoids are effective when administered systemically, they have not been shown to be effective as topical agents. We compared the topical activity of six synthetic retinoids (two arotinoids, etretinate, all-trans- and 13-cis-tetrazole-retinamide, isotretinoin, and tretinoin) on tail skin in the diazacholesterol-fed mouse model of ichthyosis. Responses were assessed clinically and by measurement of stratum corneum thickness. Although the arotinoids dramatically reduced scaling, they were toxic at concentrations above 0.1%, as was etretinate at 1.0% or greater. Lower concentrations were effective without producing local or systemic toxic reactions. Clinical responses were paralleled by equivalent decrements in stratum corneum thickness, which also permitted quantitative comparisons. The order of potency for the retinoids was as follows: arotinoids, etretinate, tetrazole-retinamides, tretinoin = isotretinoin, vehicle. These results demonstrate that (1) the synthetic retinoids hold promise as topical agents; (2) irritation is not an absolute requirement for topical retinoid activity; and (3) the diazacholesterol-fed mouse offers a new assay of topical retinoid potency in a well-defined animal model of ichthyosis.

Administration, Topical↗
PubMed1983

Diazacholesterol-induced ichthyosis in the hairless mouse. I. Morphologic, histochemical, and lipid biochemical characterization of a new animal model.

Several drugs that interfere with sterol metabolism have been associated with hyperkeratosis in man. We found that 20,25-diazacholesterol (30 to 60 mg/kg/day), administered to hairless mice that were otherwise given normal laboratory chow and water ad libitum, consistently produced ichthyosis after 6 to 9 weeks, an effect that was reversible with removal of drug or with coadministration of a high cholesterol diet. Scaling was most pronounced over the tail, but some stratum corneum retention was noted over the entire skin surface. As measured in frozen sections, stratum corneum thickness was three to 10 times thicker in treated animals than in either controls or revertants. Oil red O-stained frozen sections and freeze fracture replicas revealed decreased stratum corneum membrane lipids in the diazacholesterol-treated animals, but this finding was not specific, since a similar deficit was found in control and revertant tail stratum corneum but not in the stratum corneum from other sites. Stratum corneum lipid extracts revealed reduced total free sterols, reduced cholesterol, accumulation of several normally absent sterol precursors, and increased glycosphingolipids on thin-layer chromatography and high pressure liquid chromatography. In summary, we describe a syndrome of drug-induced ichthyosis in hairless mice that parallels the drug-induced syndrome in man. This syndrome is reversible and accompanied by distinctive abnormalities in cutaneous sterol metabolism. The diazacholesterol model may further our understanding of the pathogenesis of human keratinizing disorders and may provide a valuable analogue for testing new forms of therapy, such as retinoids, for scaling dermatoses.

Animals↗
PubMed1981

Effect of a chemical carcinogen and phorbol esters on sterol metabolism of mouse skin.

The effect of 20-methylcholanthrene and phorbol esters on sterol metabolism of mouse skin was studied. When 4 beta-phorbol esters were administered to mice that were previously painted once with 20-methylcholanthrene, a depression of some sterols in skin occurred, of which that of lathosterol was most marked. This effect was not observed when the order of application was reversed. Using a metabolic inhibitor, diazacholesterol, it was shown that sterols which reduce in mouse skin by administration of carcinogen and promoters were similar to those which reduce by administration of carcinogen only and are the members of one of the two cholesterol-biosynthetic pathways, i.e., a pathway which proceeds through intermediates with a saturated side chain. The intensity of the lathosterol-depressing effect of phorbol esters depends on the order of application of 20-methylcholanthrene and promoters, the amount of promoters, molecular species of alcoholic moiety of esters, and configuration at C-4 of phorbol moiety. Of the phorbol esters tested, 4 beta-phorbol-12-myristate-13-acetate revealed the highest activity, which was followed by 4 beta-phorbol-12,13-didecanoate, 4 beta-phorbol-12,13-dibutyrate, 4 beta-phorbol-12,13-dibenzoate, 4 beta-phorbol-12,13-diacetate, 4 alpha-phorbol-12,13-didecanoate, and 4 alpha-phorbol. 4 alpha-Phorbol was practically inactive. When beta-naphthoflavone was substituted for 20-methylcholanthrene, little effect was observed except in TPA, which revealed a rather marked lathosterol-depressing activity. Phorbol esters themselves did show some activity of lathosterol depression without prior application of 20-methylcholanthrene, but the effects were much weaker. When anthralin was applied to mouse skin after the painting of 20-methylcholanthrene, a low but definite lathosterol-depressing effect was observed.

Administration, Topical↗
PubMedDate not supplied

Experimental myotonia.

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2,4-Dichlorophenoxyacetic Acid↗