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Biomedical subjects

K Omori

Publications and source records attributed to K Omori.

At least 235 records · Page 13Linked to original sources
PubMed1977

Nucleotide sequence of a region in 23-S RNA adjacent to peptidyl transferase catalytic center of Escherichia coli ribosomes.

N-Iodoacetylphenylalanyl-tRNAPhe was used as an affinity label to localize the RNA components intimately involved in the catalytic center of Escherichia coli ribosomes. This analogue could alkylate the specific region of 23-S RNA that waslocated within 2000 nucleotides from the 3' terminus of the molecule. Sequence analysis revealed that the alkylation by the active substrate (N-iodoacetylphenylalanyl-tRNAPhe) was directed to 5'-terminal adenosine residue of a heptanucleotide, A-U-U-U-U-A-Gp, which seemed to be derived from a heptadecanucleotide, U-U-A-A-A-A-A-C-A-C-A-U-U-U-U-A-Gp, in the original 23-S RNA. The significance of the unique sequence in the ribosomal functions is discussed.

Acyltransferases↗
PubMed1976

PAH clearance, sodium excretion, and PAH extraction ratio in acidotic near-term lambs treated with hypertonic sodium bicarbonate.

The electrolyte changes and renal hemodynamic adjustment to hypertonic sodium bicarbonate (NaHCO3) correction of a metabolic acidosis were studied in 4 neonatal lambs and in 2 controls. PAH clearance increased from 0.92 to 1.65 ml/min/kg (p less than 0.05), urine flow from 0.37 to 0.61 ml/min/kg (p less than 0.05), and Na excretion from 8.4 to 23.7 muEq/min/kg (p less than 0.05) during the NaHCO3 infusion. These increases were transient and returned to pre-infusion levels following NaHCO3 infusion. Calculation of Na intake and output revealed a net retention of 5.1 mEq/kg in the study lambs which was reflected in a rise of serum Na and osmolarity (Osm) during the post-NaHCO3 -infusion period. The extraction ratio of sodium p-aminohippurate (EPAH) and its relationship to arterial pH were studied in 4 additional lambs. The EPAH did not change with metabolic acidosis but for unknown reasons, the infusion of NaHCO3 resulted in a temporary depression of EPAH (p less than 0.001).

Acidosis↗
PubMed1976

Leiomyosarcomas of the small intestine induced in dogs by N-methul-N'-nitro-N-nitrosoguanidine.

Leiomyosarcomas of the small intestine were found in dogs during experimental induction of gastric carcinoma by oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Leiomyosarcomas were found most frequenly in the duodenum and jejunum, and occasionally in the stomach but never in the ileum, colon, or rectum. The leiomyosarcomas developed in all the dogs given 50 mug/ml of MNNG in deionized water to drink but not in dogs fed on porridge food made from standard pellet diet mashed with MNNG at the same concentration in tap water. Intestinal sarcomas developed in 3 months to 5 years after the end of MNNG administration, and frequently metastasized to the liver and/or the peritoneum.

Administration, Oral↗
PubMed1975

Placenta to lamb fetus transfusion in utero during acute hypoxia.

Maternal and fetal hemodynamics, placental blood flow, fetal-placental blood volume, placental blood volume, and fetal blood volumes were measured in six chronic sheep prepartions to evaluate their changes during acute fetal hypoxia induced by maternal hypoxia. During fetal hypoxia, the maternal and fetal arterial blood pressure and heart rate were essentially unchanged. The placental blood flow (control equal to 325 ml.per kilogram per minute) was also unchanged during the hypoxia period. However, the placental blood volume decreased significantly from 65 to 60 and 51 ml. per kilogram at 15 and 30 minutes of hypoxia period, respectively. The fetal blood volume increased reciprocally and significantly from 86 to 109 and 102 ml. per kilogram at the same periods of hypoxia since the fetal-placental blood volumes were unchanged. These blood volume changes persisted for 30 to 60 minutes following the stoppage of hypoxia experiments. The placental vascular resistance measured in six experiments showed a significant increment during hypoxia, suggesting placental vasoconstriction as the responsible mechanism for the reduction of placental blood volume and reciprocal increase in fetal blood volume. The data suggest that significant placental transfusion to the lamb fetus may occur in utero during fetal hypoxia resulting in a higher fetal blood volume before birth.

Acute Disease↗
PubMed1975

Free groin skin flaps.

The operative technique of free groin flap transfer is described and some typical results presented. The overall complete success rate in 47 cases was 80 per cent, but complete necrosis only occurred in II per cent of the transferred flaps.

Adult↗
PubMed1975

Free groin flaps: their vascular basis.

By studying the vascular base of flaps raised from cadavers we obtained a basic knowledge of free groin flaps for clinical application. The method of selection of the nutrient vessels in 70 free groin flaps based on this knowledge has been described.

Child, Preschool↗
PubMed1975

Umbilical blood flow and glucose uptake in lamb fetus following single umbilical artery ligation.

Umbilical blood flow (UBF) and fetal glucose uptake were measured in 5 lamb fetuses 4-20 days following single umbilical artery ligation (SUAL). The ligation was performed at 108-119 days gestation (sheep pregnancy = 145-150 days), and the blood flow and glucose uptake studies were performed as chronic preparation at 120-137 days of gestation. In comparison with 9 control subjects at matched gestation, the SUAL fetuses had significantly lower UBF (mean plus or minus SEM, 735 plus or minus 70 vs. 475 plus or minus 24 ml/min, p less than 0.01) and fetal glucose uptake (2190 plus or minus 1.6 vs. 14.8 plus or minus 1.9 mg/min, p less than 0.05). When the values were expressed per kilogram fetal weight, the UBF decreased with increasing gestational age in SUAL fetuses. In the control fetuses, the UBF increased with increasing gestational age. The fetal glucose uptake (FGU), when expressed per kilogram fetal weight, was essentially similar to that of the control subjects. The glucose gradients across the placenta were similar in both groups of fetuses. These data suggest that in lamb fetuses with placental vascular insufficiency induced by SUAL, the reduction of UBF and FGU may account for growth retardation in utero. It was also suggested that placental transfer of substrate other than glucose may also be impaired as a result o

Animals↗
PubMed1975

The glycosaminoglycans in human hepatic cancer.

A method is proposed for the analysis of glycosaminoglycans that were isolated from human liver, combining cellulose acetate electrophoresis and enzymatic digestion with mucopolysaccharidases. The major constituent of glycossaminoglycans in the healthy liver is heparin sulfate and/or heparin (about 65%), with approximately equal quantities of dermatan sulfate and hyalauronic acid (about 13.5 and 13%, respectively) and a small amount of chondroitin sulfate. These components, especially chondroitin sulfate and hyaluronic acid, are markedly increased in hepatic carcinomas.

Adenoma, Bile Duct↗