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Biomedical subjects

K Horie

Publications and source records attributed to K Horie.

At least 217 records · Page 12Linked to original sources

Influence of sulpiride-induced hyperprolactinemia on baboon menstrual cycles: a longitudinal study.

The influence of sulpiride-induced hyperprolactinemia on the hypothalamic-pituitary-ovarian function of the baboon (Papio cynocephalus) was investigated. Plasma levels of prolactin, LH, FSH, estrone, estradiol, 17-hydroxyprogesterone, progesterone and 20 alpha-dihydroprogesterone in control and consecutive treatment cycles (sulpiride i.m. injections 100 mg/day) were determined serially. The hormonal changes indicate that the ovary is the most sensitive site to the direct inhibitory action of sulpiride-induced hyperprolactinemia.

Animals↗

Glycosylation of myelin glycoproteins in peripheral nerve via lipid intermediates.

Membrane preparations from chick peripheral nervous system (PNS) catalyzed the transfer of [3H]glucose from UDP-[3H]glucose into glucosylphosphoryl dolichol. The initial rate of glucosylphophoryl dolichol formation in a non-myelin membrane fraction from actively myelinating chick PNS was 11 fold higher than that from adult. Exogenous dolichyl monophosphate stimulated glucosylphosphoryl dolichol synthesis in both fractions. The higher level of glucosylphosphoryl dolichol synthesis corresponded to the onset of myelination in chick PNS. Exogenous dolichyl monophosphate also stimulated the labeling of glucosylated oligosaccharide lipids and glycoproteins in the fraction. On SDS polyacrylamide gel electrophoresis, the relative mobility of the major and minor radioactive glycoprotein corresponded with that of the P0 and PASII glycoprotein in PNS myelin, respectively. The results suggest that myelin glycoproteins in PNS are glycosylated via lipid intermediates.

Aging↗

Conformational studies of Escherichia coli ribosomes with the use of acridine orange as a probe.

The interaction of E. coli vacant ribosomes with acridine orange (AO) was studied, to obtain conformational information about rRNAs in ribosomes. Acridine orange binds to an RNA in two different modes: cooperative outside binding with stacking of bound AO's and intercalation between nucleotide bases. Free 16S and 23S rRNAs have almost identical affinities to AO. At 1 mM Mg2+, AO can achieve stacking binding on about 40% of rRNA phosphate groups. The number of stacking binding sites falls to about 1/3 in the 30S subunit in comparison with free 16S rRNA. In the 50S subunit, the number of stacking binding sites is only 1/5 in comparison with free 23S rRNA. Mg2+ ions are more inhibitory for the binding of AO to ribosomes than to free rRNAs. The strength of stacking binding appears to be more markedly reduced by Mg2+ in active ribosomes than in rRNAs. "Tight couple" 70S particles are less accessible for stacking binding than free subunits. The 30S subunits that have irreversibly lost the capability for 70S formation under low Mg2+ conditions have an affinity to AO that is very different from that of active 30S but similar to that of free rRNA, though the number of stacking binding sites is little changed by the inactivation. 70S and 30S ribosomes with stacking bound AO's have normal sedimentation constants, but the 50S subunits reversibly form aggregates.

Acridine Orange↗

Tags penetrating dentin of a new adhesive resin.

The change of the dentinal tubules by acid-etching and the morphology and the adhering state of new adhesive composite resin tags penetrating the tubules were observed by SEM, comparing with the representative conventional composite resin. When the fractured surface of the unetched floor dentin were observed, all tubule entrances were closed by blocking with cutting debris up to 10 to 20 micrometers depth. Etching opened them by dissolving the debris and further widened the tubule entrances up to 10 to 20 micrometers depth by dissolving the peritubular dentin near the apertures. Resin tags penetrated 10 to 20 micrometers in vital teeth, 60 to 100 micrometers in freshly extracted teeth and several hundred micrometers in old extracted teeth. The tags of the new resin penetrating the tubules copied exactly the shape of the tubule walls, producing hollow depressions at the ends, indicating that the renin polymerized, adhering tightly to the walls, while those of the conventional resin produced highly tapered side walls with pointed ends, indicating that the resin shrank separating from the tubule walls on polymerization. The new resin did not produce any gap at the resin-dentin interface unlike the conventional resin.

Acid Etching, Dental↗

Radioimmunoassay method for baboon plasma gonadotropins.

Double antibody radioimmunoassay methods were developed for the determination of baboon luteinizing hormone (bLH) and follicle stimulating hormone (bFSH). The bLH radioimmunoassay employs a unique anti-ovine LH serum (GDN-15) and ovine LH (LER-1056-C2) for radioiodination, while the bFSH radioimmunoassay employs an heterologous system, i.e., an anti-ovine FSH serum (H-31) and purified human FSH for radioiodination. The reference standard used in both assays is a crude rhesus pituitary extract (LER-1909-2). Elevated endogeneous baboon plasma TSH and prolactin induced by the intravenous administration of 500 microgram of TRH had no influence on the levels of LH and FSH, whereas simultaneous intravenous administration of 100 microgram LHRH and 500 microgram TRH raised the levels of LH and FSH in plasma. hPRL, hCG, hTSH and hGH did not cross react with either the bLH or the bFSH assay system. The determination of plasma LH and FSH concentrations in daily samples from 6 mature female baboons throughout ovulatory menstrual cycles revealed patterns qualitatively similar to those of the rhesus monkey and human females.

Animals↗

Postoperative bronchopleural fistula: clinical and experimental study.

It is a well-known fact that in pulmonary tuberculosis patients treated by resection, the quality of the suture material used for closing the bronchial stump plays an important role in the pathogenesis of postoperative bronchopleural fistula. Of 426 cases treated surgically and in whom silk suture thread was used, 23 developed bronchopleural fistula, whereas none of the 220 cases sutured with nylon monofilament developed abnormality. Statistical analysis of 100 surgical cases with silk thread suture and of 100 cases with nylon monofilament suture showed that the two groups had no marked differences as to background factors. Howevers, as compared with the silk-thread suture group, the nylon-monofilament suture group revealed more consistently favorable postoperative bronchoscopic findings. Experimental studies with dogs showed a similar lack of complications when the monofilament suture material was used, as contrasted were conducted in hospital by the same surgical personnel using the same procedures, it can be said that, to insure prevention of complications, the suture material for bronchial stump closure should be of non-irritating nature and preferably of monofilament strength and quality, such as nylon monofilament.

Animals↗