Quantitative spectrophotometric determination of nipagin in solutions for injections

Polyploid strains of Candida scottii differ by their susceptibility to the action of nistatin. Haploid strain is most resistant, diploid strain is less resistant than haploid strain, and triploid strain is more susceptible than diploid strain. UV-treatment resulted in mutants which were 1.5--2 times more resistant to the action of nistatin than parent forms. The frequency of nistatin-resistant mutants increases with the ploidity of the cultures and with the doses of UV-irradiation.     

Experimental amniocentesis and teratogenesis. 1. Evaluation of the intra-amniotic route of treatment in teratological studies

Experiments were designed to evaluate the usefulness of the intra-amniotic route of administration of test-substances in teratological studies. Particular attention was given to the differences in fetal parameters of growth and development and the incidence of fetal mortality between treated and untreated offspring which might be induced as a result of the treatment. Amniocentesis on gestational days 14, 15 or 16 produced a high incidence of fetal mortality and a significant reduction in the weights and crown-rump lengths of treated offspring. With increasing gestational age at the time of treatment and by reducing the volume of solvent injected, fetal mortality was decreased.     

Zinc sulfate: an adjuvant to wound healing in patients undergoing radical vulvectomy

In an experimental study we tried to find out whether halothane, in addition to its effects on vegetative efferents, has also an influence on catecholamine metabolism of the corresponding brain sections. We studied the effects of halothane in the brain stem of rats on dopamine and norepinephrine contents and on the transformation of L-dopa into dopamine and L-norepinephrine. Anaesthesia with 2 vol% halothane reduced dopamine content by 41.4%, norepinephrine content by 17.8%. These findings could be observed even 3 h after narcosis. Electrophysiological studies show that the central nervous sympathetic activity at rest and after central excitation is clearly reduced during anaesthesia with 2 vol% halothane; 70 min after narcosis it returned to normal. Administration of L-dopa led to an increase of dopamine by 43.5% within 45 min. This transformation of L-dopa into dopamine is not affected by concurrent halothane anaesthesia. There is no increase in norepinephrine after administration of L-dopa. Thus, the effect of halothane on catecholamine metabolism in the brain stem affects the precursors of L-dopa. Halothane is said to inhibit transport of the L-dopa precursor L-tyrosine from plasma to brain tissue. Along with such an inhibition goes the depression of the sympathetic activity. In this respect and obviously on the basis of its position within the catecholamine metabolism, dopamine is more important than norepinephrine.     

Pressure and Temperature Effects on Point-Defect Equilibria and Band Gap of ZnS

The pressure (100–200 MPa) and temperature (900–1100°C) effects on the equilibria of native point defects and background impurities in Zn-enriched ZnS are studied using cathodoluminescence and transmission spectra. The optimal conditions are found under which high pressures and temperatures accelerate migration of defects and impurities. The associated structural and compositional changes are studied by scanning electron microscopy. The increase in the concentration of dissolved oxygen at high pressures and temperatures is accompanied by a reduction in the band gap of ZnS, growth and blue shift (to 395–400 nm) of the shorter wavelength component of the SA blue emission in ZnS, and quenching of the longer wavelength component (445 nm). In addition, at 300 K a free-exciton bandI ₁ emerges at 342 nm. It is shown that the data available in the literature can be used to evaluate the concentration of dissolved oxygen in ZnS · O from its band gap. The effects of different oxygen species on the transmission of ZnS are studied in the range 3.5–15 m.