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J Kirsch

Publications and source records attributed to J Kirsch.

70 records · Page 4Linked to original sources
PubMed1983

An attempt to evaluate the relative clinical potencies of various diluted and undiluted proprietary corticosteroid preparations.

Two series of tests have been performed in order to assess the vasoconstrictor potency of several diluted and undiluted proprietary corticosteroid preparations. Results showed that differences in concentration of a particular corticosteroid were not always reflected as significant differences in vasoconstrictor potency. A previous finding that Eumovate ointment exhibits early vasoconstrictor activity similar to that of Betnovate ointment was confirmed. The extemporaneous dilution of proprietary corticosteroid preparations remains a widespread but controversial habit. In addition, several proprietary products are represented by a range of dilutions of the same corticosteroid with each concentration targeted at a different segment of the market place. Recent work by our group has revealed some interesting results concerning the vasoconstrictor potency of both diluted and undiluted preparations (Gibson et al., 1982). The aim of this study was to extend the investigation to cover a number of widely used preparations.

Administration, Topical↗
PubMed1983

A comparison of the potencies of several diluted and undiluted corticosteroid preparations using the vasoconstrictor assay.

10 subjects were assessed using the vasoconstrictor assay technique in a double-blind study in order to evaluate the relative potencies of several diluted and undiluted proprietary corticosteroid preparations. Dermovate ointment achieved a significantly higher score than any other preparation but there was no significant difference between the scores for Betnovate ointment (betamethasone valerate 0.1%), Propaderm Forte cream (beclomethasone dipropionate 0.5%), Propaderm ointment (beclomethasone dipropionate 0.025%), Nerisone Forte ointment (diflucortolone valerate 0.3%), and Nerisone ointment (diflucortolone valerate 0.1%). Furthermore, no significant difference in scores could be demonstrated between Adcortyl ointment (triamcinolone acetonide 0.1%), Ledercort ointment (triamcinolone acetonide 0.1%) and extemporaneous dilutions of these ointments 1 part in 4 in their recommended diluents (triamcinolone acetonide 0.025%). The relevance of these findings to clinical practice is discussed.

Administration, Topical↗
PubMed1982

The dilution of proprietary corticosteroid ointments--an attempt to evaluate relative clinical potencies.

Ten subjects were assessed using the vasoconstrictor assay technique in a double-blind study in order to evaluate the potencies of several diluted and undiluted proprietary corticosteroid ointments. Results showed that clobetasol propionate 0.05% (Dermovate) ointment at a dilution of one part in ten (clobetasol propionate 0.005%) in white soft paraffin was equipotent with betamethasone valerate 0.1% (Betnovate) ointment; and no difference in potency was demonstrated between beclomethasone dipropionate 0.025% (Propaderm), betamethasone valerate 0.1% (Betnovate) and clobetasone butyrate 0.05% (Eumovate).

Administration, Topical↗
PubMed1975

Mating type and sporulation in yeast. II. Meiosis, recombination, and radiation sensitivity in an alpha-alpha diploid with altered sporulation control.

In wild-type S. cerevisiae, diploid cells must be heterozygous at the mating-type locus in order to sporulate. In the preceding paper, we described a number of mutants (CSP mutants), isolated from nonsporulating aa and alpha-alpha parent strains, in which sporulation appeared to be uncoupled from control by mating type. The characterization of one of these mutants (CSP1) is now extended to other processes controlled by mating type. This mutant is indistinguishable from alpha-alpha cells and unlike aalpha cells for mating factor production and response, zygote formation, intragenic mitotic recombination, and for X-ray sensitivity. The mutant apparently undergoes a full round of DNA synthesis in sporulation medium, but with delayed kinetics. Only 20% of the cells complete sporulation. Among spores in completed asci, the frequency of both intra- and intergenic recombination is the same as it is for spores produced by aalpha cells. However, experiments in which cells were shifted from sporulation medium back to minimal growth medium gave a frequency of meiotic recombination between ade2 or leu2 heteroalleles only 25% to 29% as high for CSP1 alpha-alpha diploid or CSP1 aa disomic cells as for aalpha diploid or disomic cells. Because the latter result, indicating recombination defectiveness, measured recombinant production in the entire cell population, whereas the result indicating normal recombination sampled only completed spores, we infer that all meiotic recombination events occuring in the population of CSP1 alpha-alpha cells are concentrated in those few cells which complete sporulation. This high degree of correlation between meiotic recombination and the completion of meiosis and sporulation suggests that recombination may be required for proper meiotic chromosome segregation in yeast just as it appears to be in maize and in Drosophila.

Alleles↗
PubMed1968

Enzymes of fructose metabolism in human liver.

The enzyme activities involved in fructose metabolism were measured in samples of human liver. On the basis of U/g of wet-weight the following results were found: ketohexokinase, 1.23; aldolase (substrate, fructose-1-phosphate), 2.08; aldolase (substrate, fructose-1,6-diphosphate), 3.46; triokinase, 2.07; aldehyde dehydrogenase (substrate, D-glyceraldehyde), 1.04; D-glycerate kinase, 0.13; alcohol dehydrogenase (nicotinamide adenine dinucleotide [NAD]) substrate, D-glyceraldehyde), 3.1; alcohol dehydrogenase (nicotinamide adenine dinucleotide phosphate [NADP]) (substrate, D-glyceraldehyde), 3.6; and glycerol kinase, 0.62. Sorbitol dehydrogenases (25.0 U/g), hexosediphosphatase (4.06 U/g), hexokinase (0.23 U/g), and glucokinase (0.08 U/g) were also measured. Comparing these results with those of the rat liver it becomes clear that the activities of alcohol dehydrogenases (NAD and NADP) in rat liver are higher than those in human liver, and that the values of ketohexokinase, sorbitol dehydrogenases, and hexosediphosphatase in human liver are lower than those values found in rat liver. Human liver contains only traces of glycerate kinase. The rate of fructose uptake from the blood, as described by other investigators, can be based on the activity of ketohexokinase reported in the present paper. In human liver, ketohexokinase is present in a four-fold activity of glucokinase and hexokinase. This result may explain the well-known fact that fructose is metabolized faster than glucose.

Alcohol Oxidoreductases↗
PubMedDate not supplied

Differential expression of glycine receptor subunits in the retina of the rat: a study using immunohistochemistry and in situ hybridization.

Immunohistochemistry and in situ hybridization were used to study the distribution of glycine receptor (GlyR) subunits and the GlyR-associated protein gephyrin in the rat retina. Monoclonal antibodies against the alpha and beta subunits of the GlyR and gephyrin showed a strong punctate labeling pattern in the inner plexiform layer. Glycine receptor mRNAs were found in the inner nuclear layer and the ganglion cell layer. The alpha 1 subunit mRNA is predominantly present in the outer half of the INL and on some but not all ganglion cells. GlyR alpha 2 subunit mRNA is predominantly present in the inner half of the INL and on nearly all cells in the ganglion cell layer. GlyR alpha 3-, GlyR beta-, and gephyrin-mRNAs are present in the entire INL and in cells in the ganglion cell layer. The differential expression of glycine receptor subunits indicates a functional diversity of glycine receptors in the retina.

Animals↗
PubMedDate not supplied

Gephyrin antisense oligonucleotides prevent glycine receptor clustering in spinal neurons.

Each neuron in the mammalian brain carries many postsynaptic membrane specializations containing high densities of receptors that mediate signal transduction upon neurotransmitter release from the apposed nerve terminal. Little is known about the mechanisms by which receptors are transported to and anchored at postsynaptic sites, but extracellular as well as intracellular components may be involved. Ultrastructural studies have shown that the peripheral membrane protein gephyrin, which co-purifies with the postsynaptic inhibitory glycine receptor (GlyR) upon affinity chromatography, is situated on the cytoplasmic face of glycinergic postsynaptic membranes. Moreover, gephyrin binds with high affinity to polymerized tubulin and has been postulated to link the GlyR to the subsynaptic cytoskeleton. Here we report that treatment of rat spinal neurons in culture with gephyrin antisense oligonucleotides prevents the formation of GlyR clusters in the dendritic plasma membrane. Thus, gephyrin is essential for localizing the GlyR to presumptive postsynaptic plasma membrane specializations.

Animals↗