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Biomedical subjects

C S Tse

Publications and source records attributed to C S Tse.

36 records · Page 2Linked to original sources

Central nervous system control of hyperphagia in hypothalamic obesity: dependence on adrenal glucocorticoids.

Gold thioglucose (GTG)-treated hyperphagic obese mice exhibit a pronounced anorexia upon adrenalectomy which is reversed by the systemic administration of adrenal glucocorticoids. To determine whether the return of hyperphagia was mediated by an action of the hormones on the central nervous system, food intake and body weight were monitored in anorexic GTG-treated obese adrenalectomized mice which received a single intracerebroventricular (icv) injection of very small amounts of adrenal glucocorticoids, including cortisone, corticosterone, and dexamethasone. The responses of untreated controls and adrenalectomized control mice were also studied. To rule out possible systemic effects of icv injections of adrenal glucocorticoids, food intake and body weight were also monitored in similar mice given a single ip injection of the hormones. We found that hyperphagia was restored and weight loss abolished in anorexic GTG-treated obese adrenalectomized mice after a single icv injection of adrenal glucocorticoids; the dose of cortisone required was found to be 1/60th of that previously shown to be needed systemically to restore hyperphagia. A single ip injection of these adrenal hormones in the small amounts given icv failed to induce hyperphagia in these mice. The icv and ip injections of the adrenal glucocorticoids did not significantly affect food intake or body weight of untreated controls and adrenalectomized control mice. These findings indicate that adrenal glucocorticoids act via the central nervous system in restoring hyperphagia in anorexic GTG-treated obese adrenalectomized mice.

Adrenal Glands↗

Isotretinoin in severe, recalcitrant cystic acne: a review.

Isotretinoin, an isomer of retinoic acid, recently has been approved by the Food and Drug Administration for treatment of severe, recalcitrant acne. The most impressive effects include inhibition of sebum production and a reversible decrease in sebaceous gland size. Isotretinoin has proved to be an effective drug; response to therapy has been seen in virtually 100 percent of patients treated. Almost all patients experience reversible cutaneous and mucous-membrane symptoms while on isotretinoin treatment. Other common side effects include conjunctivitis (38 percent) and eye irritation (50 percent). The recommended dosage is 1-2 mg/kg/d for no longer than 16 weeks. Isotretinoin is currently the treatment of choice for severe, recalcitrant acne; however, because of potential side effects associated with retinoids, isotretinoin should be reserved for those patients who are unresponsive to conventional therapy, including topical and systemic antibiotics.

Acne Vulgaris↗

Baker's asthma (grain-dust-induced asthma).

A 48-year-old black male with no underlying atopy developed asthma after working nine years at a bakery. The attacks of wheezing were preceded by nasal symptoms and usually occurred after several hours of work. Skin testing revealed reactivity to dust, molds, and wheat extracts; serum level of IgE was normal, and a RAST screen to common allergens was negative. A bronchial provocation test using commercial wheat extract was negative, but the same test using the patient's own bakery flour resulted in an immediate positive reaction. The pathogenesis and management of grain-dust-induced asthma are discussed.

Adult↗

Diverse profiles of immunoreactivity in toluene diisocyanate (TDI) asthma.

Possible immunoreactivity to chemically well-characterized mono- and diisocyanate protein conjugates was reevaluated in 15 workers with TDI asthma and 17 normal (nonexposed) volunteers. Lymphocytes of nine sensitive workers were incubated with TDI human serum albumin (HSA) conjugates. Leucocyte inhibitory factor (LIF) was produced. Leucocyte inhibitory factor was also induced by hexamethylene diisocyanate (HDI) protein conjugates in four of these workers who had no prior history of exposure to HDI. Disappearance of TDI- and HDI-induced LIF was noted in several sensitive workers who were removed from further TDI exposure. Three LIF-positive workers also demonstrated positive intracutaneous reactivity to TDI-HSA. One workers had a markedly positive RAST (25.5% binding) to a monofunctional (p-tolyl isocyanate) protein reagent. These studies suggest that isocyanates have the potential for eliciting heterogeneous immune responses in certain subpopulations of exposed workers. Continued contact with isocyanates may be necessary for maintenance of specific immunity. Possible cross reactivity between TDI and HDI may be determined by new antigenic sites created by isocyanate protein interactions.

Adult↗

In vivo suppression and enhancement of the murine homocytotropic antibody response by staphylococcal enterotoxin A.

Effects of staphylococcal enterotoxin A (SEA) on the mouse homocytotropic antibody (HCA) system were studied. Groups of BDF mice received 10 micrograms SEA either orally or intraperitoneally at 0, 24, 48 h before or after immunization with 100 micrograms ovalbumin in 1 mg A1(OH)3 gel. Primary and secondary HCA responses were determined by 48-hour passive cutaneous anaphylactic reactions in genetically hairless mice. It was found that effects of SEA on HCA responses were dependent on the time and route of SEA administration. In general, early administration (48 h before immunization) of SEA showed suppression, while later administration (either 24 h before or after immunization) of SEA demonstrated enhancement. A further delay of SEA administration (48 h after immunization) exerted suppressive effects except when it was given intraperitoneally in the anamnestic HCA experiments. The mouse HCA system proved to be a suitable in vivo correlate of in vitro plaque-forming cell responses modulated by SEA.

Animals↗

Corticosteroid aerosols in the treatment of asthma.

Since the 1950s, corticosteroid aerosols have proved useful in the treatment of asthma. Although their precise mechanism of action is not known, these topical agents have beneficial antiinflammatory and decongestive effects on the bronchial tree in both the allergic and nonallergic forms of this disease. Four of the newer aerosolized steroids--beclomethasone dipropionate, triamcinolone acetonide, flunisolide and budesonide--have been evaluated in clinical trials. The last drug is still investigational. Their side effects are minimal, the major ones being oral candidiasis and dysphonia. They are most effective when used prophylactically and should not be administered during acute asthmatic attacks, as insufficient amounts of drug are inhaled when the airways are obstructed. Patients must be instructed in the correct techniques of administering steroid aerosols to ensure optimal therapy.

Adrenal Cortex Hormones↗

Is home tooth bleaching gel cytotoxic?

Tooth whitening systems are widely used clinically and for home usage. The aim of this study was to determine the effects of two bleaching gels, each containing 10 percent and 15 percent carbamide peroxide, respectively, a 'bleaching gel' without carbamide peroxide, and carbamide peroxide alone on the viability of human endothelial cells in vitro in comparison with culture medium that acted as a negative control. The incubation period used was 30 minutes. A colorimetric viability assay (MTT assay) was employed. The results showed that the gel without carbamide peroxide is not cytotoxic compared to the negative control, while carbamide peroxide on its own and 10 percent and 15 percent carbamide peroxide bleaching gels were cytotoxic, but there were no significant differences (p greater than 0.05) among these latter three test groups. These data indicate that 10 percent and 15 percent carbamide peroxide bleaching gels are cytotoxic and that carbamide peroxide is the component responsible for this cytotoxic effect. This paper also discusses why this in vitro cytotoxic effect appears not to be significant in vivo.

Analysis of Variance↗