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V Kahn

Publications and source records attributed to V Kahn.

4 recordsLinked to original sources
PubMed1992

Effect of different isomers of dihydroxybenzoic acids (DBA) on the rate of DL-dopa oxidation by mushroom tyrosinase.

Dihydroxybenzoic acids (DBA), such as 3,4-DBA, 3,5-DBA, and 2,4-DBA--at all concentrations tested--inhibited the rate of DL-DOPA oxidation to dopachrome (lambda max = 475 nm) by mushroom tyro0sinase. 2,3-DBA and 2,5-DBA at relatively low concentration had a synergistic effect on the reaction, whereas at relatively high concentrations they inhibited the rate of DL-DOPA oxidation. The synergistic effect of 0.6-13.3 mM 2,3-DBA on the rate of DL-DOPA oxidation to dopachrome (lambda max = 475 nm) was found to be due to the ability of 2,3-DBA-o-quinone (formed by the oxidation of 2,3-DBA by mushroom tyrosinase or by sodium periodate) to oxidize DL-DOPA to dopachrome (via dopaquinone) non-enzymatically. A similar explanation is likely to be valid for the synergism exerted by 2,5-DBA on the rate of DL-DOPA oxidation by mushroom tyrosinase.

Basidiomycota↗
PubMed1992

Synergism exerted by 4-methyl catechol, catechol, and their respective quinones on the rate of DL-DOPA oxidation by mushroom tyrosinase.

4-Methyl catechol and catechol, at concentrations ranging from 0.03 to 9 mM and 0.066 to 20 mM, respectively, have a synergistic effect on the rate of DL-DOPA oxidation by mushroom tyrosinase to material absorbing at 475 nm. The synergism results from the ability of 4-methyl catechol-o-quinone (4-methyl-o-benzoquinone) and of catechol-o-quinone (o-benzoquinone) to oxidize DL-DOPA non-enzymatically to dopaquinone, with the later being immediately converted to dopachrome (lambda max = 475 nm).

Basidiomycota↗
PubMed1976

The teaching of child psychiatry in U.S. medical schools: results of a survey.

The major results of this survey are that most schools have special programs in child psychiatry and that these are distinct from the adult psychiatry course. The course content involves clinical evaluation of children, information on child development and psychopathology, assigned reading, and liaison with pediatrics. Most schools have full-time psychiatrists on their faculty, and the child psychiatry course is taught by child psychiatrists; but less than 20 percent of the psychiatric faculty are child psychiatrists in a majority of the schools in the country. Finally, although evaluation by students and faculty is common in most of the schools, only slightly more than one-third of the institutions gave grades in child psychiatry and slightly fewer than one-third gave examinations in this subject.

Child Psychiatry↗