The oxidation of zinc vapor in CO-CO2-N2 gas mixtures

The kinetics of oxidation of zinc vapor in the Zn-CO-CO₂-N₂ system was investigated for zinc partial pressures of 0.01 to 0.09 atm, carbon monoxide partial pressures up to 0.5 atm, and carbon dioxide partial pressures up to 0.6 atm at 730 °C to 900 °C. The experimental apparatus consisted of a flow reactor and a multitemperature zone furnace. Known gas compositions were generated and the rate of oxidation of zinc vapor was determined from the mass of zinc oxide deposited under controlled conditions. The rate of oxidation of zinc was found to be a function of temperature and of the partial pressures of zinc, carbon monoxide, and carbon dioxide. It was autocatalytic with respect to carbon monoxide and independent of the total mass of zinc oxide deposited. The reactions occurring in parallel for this mechanism are

Activation and detoxification of dinitropyrenes by cytosol and microsomes from Aroclor-pretreated rats in the Ames and umu assays

PURPOSE: To evaluate the efficacy of topical mitomycin C in treating conjunctival and corneal epithelial dysplasia and neoplasia. METHODS: Seven eyes of seven patients with conjunctival and corneal epithelial dysplasia and neoplasia were treated with one drop of topical mitomycin C 0.04% four times a day for 7 days in alternate weeks. The patients' charts were reviewed retrospectively. Patients with either multiple recurrences or extensive ocular surface involvement were treated. In all eyes, the diagnosis of epithelial dysplasia or neoplasia was confirmed by histopathology before the onset of therapy. Patients were examined at least every 14 days during treatment and examined at intervals after completion of treatment. RESULTS: With topical mitomycin C, six eyes of seven patients had complete clinical regression of their conjunctival and corneal epithelial dysplasia and neoplasia. One eye of one patient had partial clinical regression of conjunctival and corneal epithelial dysplasia. Follow-up after completion of topical mitomycin C therapy and excision of residual disease ranged from 2 to 16 months (mean, 9 months; SD, 4.3 months) and was without clinical sign of recurrence. Topical mitomycin C therapy was associated with transitory ocular discomfort, conjunctival injection, tearing, photophobia, and punctate epithelial keratopathy. CONCLUSION: In this small series of eyes, topical mitomycin C was effective as a treatment for conjunctival and corneal epithelial dysplasia and neoplasia.     

Biosynthesis of a cyclic tautomer of (3-methylmaleyl)acetone from 4-hydroxy-3,5-dimethylbenzoate by Pseudomonas sp. HH35 but not by Rhodococcus rhodochrous N75

Vitamin E is one of the most important lipid-soluble antioxidant nutrients. Severe vitamin E deficiency can have a profound effect on the central nervous system. Cystic fibrosis, chronic cholestatic liver disease, abetalipoproteinemia, short bowel syndrome, isolated vitamin E deficiency syndrome and other malabsorption syndromes all may cause varying degrees of neurologic deficits due to related vitamin deficiencies. The classic abnormalities in vitamin E deficiency progress from hyporeflexia, ataxia, limitations in upward gaze and strabismus to long-tract defects, profound muscle weakness and visual field constriction. Patients with severe, prolonged deficiency may develop complete blindness, dementia and cardiac arrhythmias. Treatment must be tailored to the underlying cause of vitamin E deficiency and may include oral or parenteral vitamin supplementation. The more advanced the deficits, the more limited the response to therapy. Therefore, a good neurologic examination and periodic serum vitamin E levels are essential in patients at risk of vitamin E deficiency.     

Studies on anti-inflammatory agents. V. Synthesis and pharmacological properties of 3-(difluoromethyl)-1-(4-methoxyphenyl)-5- [4-(methylsulfinyl)phenyl]pyrazole and related compounds

A series of novel 1,5-diphenylpyrazole derivatives bearing hydrophilic substituents was prepared. The anti-inflammatory and analgesic activities of these compounds were evaluated by using the adjuvant arthritis and Randall-Selitto assays in rats, and the structure-activity relationships were studied. The optimal compound was 3-(difluoromethyl)-1-(4-methoxyphenyl)-5-[4-(methylsulfinyl)phenyl]pyraz ole (10) with oral ED50 values of 0.31 and 2.6 mg/kg on adjuvant-induced arthritis and carrageenin-induced foot edema, respectively. Compound 10 showed analgesic activities not only toward inflamed paw but also toward normal paw (ED30 = 0.55 and 1.8 mg/kg, respectively) in the Randall-Selitto assay, and moreover, 10 was effective in the tail-pinch assay (ED50 = 21 mg/kg) similarly to morphine. The asymmetric synthesis and pharmacological properties of the enantiomers of 10 are also reported.