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Biomedical subjects

K Shibata

Publications and source records attributed to K Shibata.

At least 559 records · Page 31Linked to original sources
PubMed1989

[Continuous wave Doppler echocardiographic evaluations of the severity of mitral regurgitation].

To ascertain the usefulness of continuous wave Doppler echocardiography in evaluating the severity of mitral regurgitation (MR), 29 patients with MR and 10 normal subjects were examined. The patients were categorized in three groups according to the angiographic evidence of severity of MR. To analyze the flow velocity patterns of MR, the time to peak velocity index (time from onset of MR signal to peak flow velocity/duration of MR signal), the A/B ratio (the ratio of the first and second half of the systolic MR signal area), systolic peak velocity, and diastolic peak velocity were measured using continuous wave Doppler echocardiograms. The velocity patterns of MR differed significantly among the three groups. With severer MR, the flow velocity pattern showed an earlier appearance of the peak in systole, a steeper decrease in systole and a greater increase in early diastole. The time to peak velocity index was 55 +/- 7% (mean +/- SD) in mild MR, 42 +/- 6% in moderate MR and 35 +/- 5% in severe MR. This index shortened significantly in accord with the severity of MR (mild vs moderate MR: p less than 0.001, moderate vs severe MR: p less than 0.05). The A/B ratio was 1.06 +/- 0.12 in mild MR, 1.23 +/- 0.10 in moderate MR and 1.41 +/- 0.07 in severe MR. This ratio increased significantly with the severity of MR (mild vs moderate MR: p less than 0.01, moderate vs severe MR: p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Right ventricular regional wall motion and function after tetralogy repair].

The right ventricular (RV) function is very important after correction of tetralogy of Fallot (TOF) similarly to left ventricular (LV) function. The influence to RV contraction caused by RV outflow tract patch after repair of TOF is serious. There are a few literatures about contraction mode of RV but we can't see any reports about regional RV wall motion before and after surgery of TOF. This paper is the first report about RV regional wall motion and function after 20 cases of tetralogy repair. We would emphasize the following points. 1) Regional wall motion of RV at antero-basal and anterolateral is getting worse but is improved at anteroapical of RV. 2) Appropriate rate of RV systolic pressure to LV systolic pressure just after weaning from cardiopulmonary bypass and rate of patch length to RV length is below 0.5 and 0.4 respectively. 3) There is positive correlation between RV ejection fraction and wall motion at anteroapical of RV.

Child↗
PubMed1989

[A case of Morgagni's hernia complicated with esophageal hiatus hernia].

A rare case of Morgagni's hernia complicated with esophageal hiatus hernia is reported. A 85-year-old female suffered from swallowing disturbance admitted for evaluation of abnormal finding on chest X-ray film. The diagnosis was confirmed by chest roentgenogram, gastro-intestinal series and CT scan. Satisfactory repair was performed by the transabdominal approach and the postoperative course was excellent without any complication.

Aged↗
PubMed1988

The mammillary body, a potential site of action of neurotensin in passive avoidance behavior in rats.

Sites of action of neurotensin (NT) in passive avoidance behavior were investigated by intracerebral injection in male Wistar rats, which were trained in a step-down type one-trial learning passive avoidance test. An unavoidable foot shock was delivered through the grid floor of a dark compartment (learning trial) and passive avoidance latencies were tested 24 h after the learning trial (retention test). NT at small doses, 0.2 and 0.5 microgram, injected into the mammillary body increased the latency of the retention test in passive avoidance behavior, without affecting locomotor activity or rectal temperature. However, NT injected into the central amygdaloid nucleus did not influence either passive avoidance behavior or rectal temperature. When injected into the preoptic area, the nucleus accumbens or the substantia nigra, NT did not alter the passive avoidance behavior either. Responsiveness to electric foot shock was reduced after injection of NT into the mammillary body. Thus, the change in the responsiveness to electric foot shock did not comply with that in the passive avoidance behavior following intramammillary body injection of NT. These results suggest that the mammillary body is a site of action of NT in passive avoidance behavior and may play an important role in learning the behavior.

Animals↗
PubMed1988

Simultaneous micro-determination of nicotinamide and its major metabolites, N1-methyl-2-pyridone-5-carboxamide and N1-methyl-4-pyridone-3-carboxamide, by high-performance liquid chromatography.

A simultaneous micro-determination of nicotinamide and its major metabolites, N1-methyl-2-pyridone-5-carboxamide (2-py) and N1-methyl-4-pyridone-3-carboxamide (4-py) by high-performance liquid chromatography is described. The method employs a 7-ODS-L (250 mm X 4.6 mm I.D., particle size 7 microns) column eluted with 10 mM potassium dihydrogenphosphate-acetonitrile (96:4, v/v; pH adjusted to 3.0 by the addition of concentrated phosphoric acid) at a flow-rate of 1.0 ml/min. The UV detector was set at 260 nm. The detection limits for nicotinamide, 2-py and 4-py were 10 pmol (1.22 ng), 2 pmol (304 pg) and 2 pmol (304 pg), respectively, at a signal-to-noise ratio 5:1. Isonicotinamide was used as an internal standard. The technique was applied to the analysis of rat and human urines. The total analysis time was ca. 15 min.

Animals↗
PubMed1988

Tricuspid regurgitation due to chest trauma: an unusual laceration around the annulus of the anterior leaflet.

A 70-year-old male with tricuspid regurgitation due to a blunt chest trauma inflicted 16 years previously underwent prosthetic valve replacement. At surgery, a tear, which produced tricuspid regurgitation, was found around the annulus of the anterior leaflet of the tricuspid valve. Since this area has not been reported as a location for heart trauma-producing tricuspid regurgitation, a possible mechanism of tricuspid regurgitation is discussed in this patient.

Aged↗
PubMed1988

Production of normal piglets from microsurgically split morulae and blastocysts.

The embryo splitting technique was applied to pig embryos, and the developmental ability of the split embryos was examined by means of in vitro culture and transfer. Morulae, early blastocysts and blastocysts were collected from Landrace x Large White F(1) gilts which had been mated to Duroc boars. The embryos were bisected with a fine glass or alloy (PtIr) needle after the softening of zonae pellucidae. The halved-embryos, which had either been placed in zonae pellucidae or not, were transferred to recipient gilts immediately after the micromanipulation (Experiment 1) or after cultivation for 15 to 20 h (Experiment 2). In Experiment 1, two fetuses were obtained from one of three recipients which had received 12 half-embryos. In Experiment 2, three of five recipients became pregnant, and in one recipient, seven piglets of a litter were obtained from 12 zona-free half-embryos produced from the original seven blastocysts. The results obtained indicate that a simple method not requiring the encasing of split embryos into zonae pellucidae is satisfactory to produce viable half-embryos.

Journal Article↗
PubMed1988

Regulation of biosynthesis and phosphorylation of P210bcr/abl protein during differentiation induction of K 562 cells.

The changes of P210bcr/abl and other tyrosine phosphorylated proteins in K562 cells during growth and differentiation were studied by metabolic labeling with 32PO4 and immunoprecipitation with anti-phosphotyrosine sera. The anti-phosphotyrosine sera recognized P210bcr/abl and other phosphoproteins with mol wt of 150, 115, 100, 70 and 64 kD. The 2-day incubation of K562 cells with inducers for differentiation, hemin, sodium butyrate and TPA, decreased the level of P210bcr/abl protein and other phosphoproteins. Inhibitors of tyrosine protein kinase, amiloride and genistein, also reduced the phosphorylation of P210bcr/abl protein and other substrates, but did not induce differentiation of the cells. Although most of these additives inhibited the cell growth, cytotoxic agents such as adriamycin, vincristine and Ara-C did not affect the level of P210bcr/abl protein. The experiments using 35S-methionine labeled cells and the immunoprecipitation with anti-abl sera suggested that reduced biosynthesis but not dephosphorylation of P210bcr/abl protein mainly accounted for the reduction of P210bcr/abl protein reacting to anti-phosphotyrosine sera in differentiation-induced cells. These results indicate that the reduction of P210bcr/abl protein synthesis plays some roles in cellular differentiation of K562 cells.

Cell Differentiation↗
PubMed1988

Purification and characterization of an arginine-specific carboxypeptidase from Mycoplasma salivarium.

The carboxypeptidase which had been shown to be present exclusively in nonfermentative mycoplasmas was found to be associated with cell membranes of Mycoplasma salivarium. The enzyme was released from the membranes with Triton X-100 and purified by ion-exchange chromatography on DEAE-Sephacel, affinity chromatography on arginine-Sepharose 4B, and chromatofocusing. The purified enzyme had a molecular mass of 218 kilodaltons, as estimated by gel filtration through Sepharose CL-6B, and yielded one band of activity in analytical disc-polyacrylamide gel electrophoresis performed in the presence of 0.5% (wt/vol) Triton X-100. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme treated in the presence or absence of 2-mercaptoethanol revealed one band with a molecular mass of 87 kilodaltons. The enzyme catalyzed selectively the cleavage of the C-terminal arginine residue of peptides such as N-benzoylglycyl-L-arginine, tuftsin, and bradykinin and was inhibited considerably by o-phenanthroline and EDTA but only slightly by NiCl2. The inhibition of the enzyme by EDTA was fully reversed by the addition of ZnCl2, whereas the addition of CoCl2 activated the enzyme.

Arginine↗
PubMed1988

Chemical modification of hitachimycin. Synthesis, antibacterial, cytocidal and in vivo antitumor activities of hitachimycin derivatives.

Several acyl derivatives of hitachimycin have been synthesized and their activities, including antibacterial, cytocidal against HeLa cells and in vivo antitumor against sarcoma 180, evaluated. Some of these derivatives showed higher antitumor activity than hitachimycin. Among the derivatives, 11-O-propionyl-15-O-butyrylhitachimycin (12) and the 11-O-acylhitachimycins (15-17) were most effective in in vivo assay.

Acylation↗
PubMed1988

Clinical application of a new vital staining method for the conduction system during heart operations.

A new method for vital staining of the conduction system during heart operations, the iodine gas method, was used in 12 patients. The right bundle branch stained well in all cases, and could be confirmed by the naked eye. The conduction system was not damaged by the staining procedure. The iodine gas used in this method had no adverse effects on thyroid function (thyroxine, triiodothyronine, thyroxine binding globulin, protein bound iodine) or liver function (serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, lactic dehydrogenase). This method, therefore, was found to be valuable and without complication for preventing conduction disturbances during cardiac operations.

Cardiac Surgical Procedures↗