Biomedical subjects

Y Shneyour

Publications and source records attributed to Y Shneyour.

6 recordsLinked to original sources

PubMed2000

Congenital diaphragmatic hernia in a family segregating a reciprocal translocation t(5;15)(p15.3;q24).

Congenital diaphragmatic hernia (CDH) is a relatively common malformation of unknown cause with high mortality due to hypoplasia of the lungs and pulmonary hypertension. We studied a family in which two fetuses had CDH, and two pregnancies resulted in first trimester missed abortions. Both fetuses with CDH had an apparently normal karyotype. In a subsequent pregnancy, fluorescent in situ hybridization analysis of amniocytes showed a balanced translocation 46,XY, t(5;15) (p15.3;q24) also present in the mother and in a normal child, suggesting that the diaphragmatic hernia in the first two fetuses was caused by a cryptic unbalanced translocation. This hypothesis is supported by a previous observation of CDH in a distal deletion of 15q as part of a multiple congenital anomalies syndrome. It is suggested that a gene distal to 15q21 is important for the normal development of the diaphragm.

Abortion, Induced↗

PubMed1993

A possible effect of ultrasound on RNA synthesis in cultured amniocytes.

The effect of both diagnostic and therapeutic ultrasound on cellular RNA synthesis was investigated in amniocytes cultured in F-10 medium enriched with fetal calf serum. The rate of RNA synthesis was tested using incorporation of H3 uridine, which was added following the exposure to acid insoluble RNA. Cultured amniocytes which were not exposed to ultrasound served as the control. Different results were obtained following the two ranges of exposure. A significant decrease in RNA synthesis was demonstrated immediately following diagnostic ultrasound and a certain increase in RNA synthesis was demonstrated soon after exposure to therapeutic doses. These effects were transient and could not be shown 24 hours later. It is concluded that the routine use of ultrasound can not have any clinical implications on RNA synthesis.

Amniotic Fluid↗

PubMed1983

G-418, an elongation inhibitor of 80 S ribosomes.

The mode of action of the aminoglycoside G-418 was studied in wheat-germ, cell-free translation systems programmed with rat-liver polyadenylated RNA. Incorporation of amino acids into protein was effectively inhibited by G-418 in the microM concentration range. The inhibition pattern obtained was not uniform. The synthesis of polypeptides with higher molecular weights was more inhibited than that of smaller polypeptides. An identical inhibition pattern within a similar range of concentrations was obtained with cycloheximide, a known elongation inhibitor. Translation activity was abolished when the wheat-germ 80 S ribosomes were removed and could be partially reconstructed upon addition of the ribosomes. Incubation with G-418 prior to isolation yielded ribosomes defective in their reconstruction ability. The inhibition pattern was not uniform and exhibited again the same relationship between the size of a polypeptide and the extent of inhibition of its synthesis. Therefore, we suggest that in wheat-germ, cell-free translation systems G-418 affects the 80 S ribosomes and inhibits the elongation cycle.

Animals↗

PubMed1983

Mutator activity in Schizophyllum commune.

A strain with an elevated level of spontaneous mutations and an especially high rate of reversion at a specific locus (pab-) was identified. The mutator trait is recessive. UV sensitivity and the absence of a UV-specific endonucleolytic activity were associated with the enhancement of the mutation rate in mutator strains. The endonuclease associated with the regulation of the mutation rate also acted on single-stranded DNA. The molecular weight of this enzyme is about 38000 daltons.

Agaricales↗

PubMed1978

Selection with cycloheximide of metabolic and UV-sensitive mutants of Schizophyllum commune and Saccharomyces cerevisiae.

The difference in lethality to cycloheximide between actively dividing and non-dividing cells was exploited to enhance detection of auxotrophic and UV-sensitive mutants in the fungi Schizophyllum commune and Saccharomyces cerevisiae.

Agaricales↗

PubMed1976

Ultrastructure of an indigotin-producing dome mutant of Schizophyllum commune.

Electron microscopic observations of an indigotin-producing dome mutant of Schizophyllum commune Fr. have shown that large wall ingrowths occur within the hyphae. These ingrowths are coupled with morphological abnormalities produced by the dome mutation. The pigment indigotin appears to be produced by progressive condensation within vacuoles and to a lesser extent within the wall ingrowths. Cytochemical techniques have shown that the wall ingrowths are similar in structure to the hyphal walls. there was no evidence for the passage of condensed indigotin into the medium; the pigment granules found in the medium must therefore form outside the hyphae.

Agaricales↗