BACKGROUND: The epidermal permeability barrier necessary for terrestrial life resides in the intercellular spaces of the stratum corneum and is composed of lipids. OBJECTIVE: Since strrtum corneum lipid may be important for the permeability barrier, we studied the differences and effects of experimentally altered barrier function using acetone and tape-stripping technique. METHODS: The permeability barrier of hairless mouse was disrupted by tape-stripping and acetone treatment and the recovery rate was assessed by histochemical staining, electron microscopic examination and lipid analysis. RESULTS: Although the transepidermal water loss recovered completely by 48 hours in both of the acute models, acetone treated samples seem to have on over-all better recovery rate than tape-stripped samples. The return of barrier function to normal in both tape-stripped and acetone-treated skin was accompanied by a comparable return of normal nile red and ruthenium tetroxide staining. The amount of lipid in stratum corneum paralleled both the return of barrier function towards normal and the extent of prior damage to the barrier in acetone treated skin, yet, the lipid synthesis in tape-stripped skin showed a slower return of lipid content. CONCLUSION: The difference in the recovery rate of the two acute models may be due to the fact that acetone mainly extracts intercellular lipids, whereas, tape-stripping has a prolonged effect by removal of comeocyte in addition to the intercellular lipids. This shows the importance of comeocytes as well as the intercellular lipid bilayer in the recovery of normal barrier function.
Acetone* ; Animals ; Extracellular Space ; Lipid Bilayers ; Mice ; Mice, Hairless ; Permeability ; Ruthenium ; Skin ; Water

No abstract available.
C-Reactive Protein* ; Child* ; Diagnosis, Differential* ; Humans ; Meningitis*

Stratum corneum lipids, which are enriched in sphingolipids, free fatty acids, and cholesterol, are required for epidermal barrier function. When the epidermal permeability barrier is perturbed, the transepidermal water loss returns to normal by 24-48 hours in parallel with the reappearance of stratum corneum lipids, derived from secreted lamellar bodis and accelerated lipid synthesis. Recent evidence shows that topical application of individual lipids interferes with barrier recovery while complete mixtures of cholesterol, fatty acids, and ceramides facilitate recovery after barrier disrupton. Metabolic imbalances and perturbed barrier function can be either the cause or the consequences of the pathobiology of scaling disease. Many skin diseases relating cornification and dryness are indeed related to abnormality of one or several combinations of lipids. Recently the cytokines which have changed during barrier recovery seem to be important in understanding of epidermal lipid homeostasis as well as barrier recovery.
Ceramides ; Cholesterol ; Cytokines ; Fatty Acids ; Fatty Acids, Nonesterified ; Homeostasis* ; Permeability ; Skin Diseases ; Sphingolipids ; Water

No abstract available.

BACKGROUND: Paraquat, a widely used herbicide, is extremely toxic, causing multiple organ failure in humans. Paraquat especially leads to irreversible progressive pulmonary fibrosis, which is related to oxygen free radicals. However, its biochemical mechanism is not clear. Natural mechanisms that prevent damage from oxygen free radicals include changes in glutathione level, G6PDH, superoxide dismutase(SOD), catalase, and glutathione peroxidase. The authors think catalase is closely related to paraquat toxicity in the lungs METHOD: The effects of 3-amino-1,2,4-triazole(aminotriazole), a catalase inhibitor, on mice administered with paraquat were investigated. We studied the effects of aminotriazole on the survival of mice administered with paraquat, by comparing life spans between the group to which paraquat had been administered and the group to which a combination of paraquat and aminotriazole had been administered. We measured glutathion level, glucose 6-phosphate dehydrogenase(G6PDH), superoxide dismutase(SOD), catalase, and glutathione peroxidase(GPx) in the lung tissue of 4 groups of mice: the control grouts, group A(aminouiazole injected), group B(paraquat administered), group C(Paraquat and aminotriazole administered). RESULTS: The mortality of mice administered with paraquat which were treated with aminotriazole was significantly increased compared with those of mice not treated with aminotriazole. Glutathione level in group B was decreased by 20%, a significant decrease compared with the control group. However, this level was not changed by the administration of aminotriazole(group C). The activity of G6PDH in all groups was not significantly changed compared with the control group. The activities of SOD, catalase, and glutathione peroxidase(GPx) in the lung tissue were significantly decreased by paraquat administration(group B); catalase showed the largest decrease. Catalase and GPX were significantly decreased by aminotriazole treatment in mice administered with paraquat but change in SOD activity was not significant.(group C). CONCLUSION: Decrease in catalase activity by paraquat suggests that paraquat toxicity in the lungs is closely related to catalase activity. Paraquat toxicity in mice is enhanced by aminotriazole administration, and its result is related to the decrease of catalase activity rather than glutathione level in the lungs. Production of hydroxyl radicals, the most reactive oxygen metabolite, is accelerated due to increased hydrogen peroxide by catalase inhibition and the lung damage probably results from nonspecific tissue injury of hydroxyl radicals.
Amitrole* ; Animals ; Catalase ; Free Radicals ; Glucose ; Glutathione ; Glutathione Peroxidase ; Humans ; Hydrogen Peroxide ; Lung* ; Mice* ; Mortality ; Multiple Organ Failure ; Oxygen ; Paraquat* ; Pulmonary Fibrosis ; Superoxides

No abstract available.
Child* ; Humans

No abstract available.
Hernia* ; Pneumoperitoneum*

No abstract available.
Anemia* ; Child* ; Communicable Diseases* ; Humans

No abstract available.
Child* ; Guillain-Barre Syndrome* ; Humans ; Plasmapheresis*

No abstract available.
Humans ; Infant*