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Biomedical subjects

T Kishikawa

Publications and source records attributed to T Kishikawa.

At least 55 records · Page 3Linked to original sources

Effect of methylergometrine maleate (methergin) on electrical and mechanical activities of pregnant human myometrium.

The effect of methylergometrine maleate (methergin) on electrical and mechanical activities of pregnant human isthmic myometrium was examined. Methergin (10(-8)-10(-6) g/ml) enhanced plateau potential and contraction, however, the effects were not prominent. Plateau potential and contraction were also potentiated after pretreatment with 10(-7) g/ml phentolamine (alpha-blocker), however 10(-7) g/ml methergin further increased these effects. It is suggested that methergin might potentiate contractions by changing the pattern of action potentials and not by alpha-adrenoceptor.

Action Potentials↗

Recurrent bleeding after arterial embolization in patients with hemoptysis.

Thirty-three patients with hemoptysis caused by nonmalignant diseases underwent arterial embolization. In seven (21.2 percent) of 33 patients, hemoptysis recurred after initial embolization in a follow-up period ranging from one day to four years. Although there was no difference in age and daily quantity of bleeding among patients with and without recurrences, those with mycetoma suffered the highest recurrence of bleeding after initial embolization (three [75 percent] of four patients). In the initial arteriograms of the seven patients were found six cases of markedly increased vascularity, three of increased vascularity in the bilateral lung, and three of nonbronchial systemic arterial supply to the diseased lung. Of six patients who received reexamination at the time of recurrent bleeding, the arteriogram demonstrated recanalization of previously embolized artery in five and revascularization by collateral circulation in five. In addition, hemoptysis recurred in three (60 percent) of five patients after second embolization and in one (50 percent) of two after third embolization. Four patients underwent surgical therapy: two after the initial embolization, one after the second, and one after the third, and these patients had no recurrence. While arterial embolization as initial treatment of hemoptysis is a highly useful procedure, this is a palliative procedure and potential for recurrence of hemoptysis exists as the lesion that has initially caused hemoptysis is not cured by the embolization. We emphasize that a combination therapy of repeated embolization and surgery will probably improve the efficacy of treatment of recurrent bleeding after initial embolization.

Adult↗

Spontaneous resolution of multiple hemangiomas of the brain. Case report.

A case of multiple intracerebral hemangiomas is reported. The lesions were angiographically hypervascular and accompanied by marked perifocal brain edema. After removal of the main lesion and postoperative steroid administration, the rest of the lesions resolved spontaneously. Histologically, the lesion was composed of capillaries and fibromyxoid stroma. The distinctive clinical, radiological and histological features of this lesion are discussed in contrast to several other types of intracranial vascular tumors.

Adult↗

Phospholipase activities of surfactant fractions and their role in the morphological change in surfactants in vitro.

Rat lung surfactants including lamellar body, common myelin and tubular myelin were evaluated for enzyme activities of phospholipase A and phospholipase C using [14C] phosphatidylcholine as the substrate. The metabolic profiles of phosphatidylcholine were correlated with ultrastructural changes of each fraction in vitro incubation to elucidate whether any of these enzymes has a role in the morphological change. Lamellar body showed phospholipase A and phospholipase C activities at neutral pH. Electron microscopic observation showed that although these enzymes had no direct role in change of integration of the lamellar body to lattice tubule, phospholipase C had a role in modulation of the lamellar body to loose lamellae, and phospholipase A had a role in degradation of lattice integration.

Acetophenones↗

Clinical features of long contraction wave recorded by an external tocodynamometer.

Clinical features of a long contraction wave, lasting 3 minutes or more, recorded on an external tocodynamometer were studied. The long wave was observed in 50 out of 1,050 pregnant women. Clinical significance was not indicated by the shape of each wave which was either a long relaxing type or a fused type, but by the frequency of occurrence. Vaginal delivery and its close relation to oxytocin administration were significantly more frequent in the sporadic type, in which the long wave was observed once within a week, and fetal distress and a low Apgar score were more frequently observed in the frequent type, in which long waves occurred twice or more within a week. The results suggest that the obstetric prognosis is normal unless the long wave occurs sporadically and its recovery is good, and that it is ominous when long waves are observed twice or more within a week. Careful observation is needed in that case.

Adult↗

[Computed tomographic diagnosis of postoperative maxillary cyst (POMC)--a comparison with conventional tomography].

We reviewed the computed tomographic (CT) findings of postoperative maxillary cyst (POMC) in 64 patients with 79 lesions, and evaluated its diagnostic efficacy. Typical CT finding of POMC was an expansile and homogeneous soft tissue mass with bone erosion. Thin-walled capsule and bony septation were also demonstrated in 72% and 35% of the lesions, respectively. A comparison between conventional tomography and CT has been made in the same subjects for evaluation of the detectability and extension diagnosis of POMC. CT proved to be superior to conventional tomography in diagnosing the presence and the extent of POMC. We conclude that conventional tomography is not necessary in diagnosis of POMC, when full examination of the paranasal sinus is performed by CT.

Adult↗

[Diagnostic imaging of gallbladder carcinomas with special reference to ultrasonographic findings. Retrospective review with emphasis on diagnostic problems in preoperatively undiagnosed gallbladder carcinomas].

The diagnostic images of twenty surgically-resected gallbladder carcinomas were retrospectively reviewed for correlations with macroscopic findings. Among them, nine cases were correctly diagnosed preoperatively; 11 were not. Macroscopically, all correctly diagnosed lesions were elevated type carcinomas. Preoperatively undiagnosed lesions were comprised by 9 superficial and 2 elevated types of carcinomas. None of these 11 undiagnosed carcinomas could be identified on retrospective review of the ultrasonographic findings. Thorough evaluation of the gallbladder wall was prevented by gallstones and/or emphysema in 6 cases, and by contraction of the gallbladder in 4 cases. There was no definite evidence of wall thickening in one case of diffuse superficial carcinoma involving the muscle layer. As for lesion detectability, computed tomography was inferior to ultrasonography, though the former demonstrated localized wall thickening of the gallbladder in the majority of cases of elevated type carcinomas. Intravenous cholangiographic findings were non-specific.

Adenocarcinoma↗

Characterization of DNA rearrangements of N-myc gene amplification in three neuroblastoma cell lines by pulsed-field gel electrophoresis.

We characterized N-myc gene amplification in three human neuroblastoma cell lines (IMR-32, TGW, GOTO). Rearrangements in long-range regions surrounding amplified N-myc genes were examined by pulsed-field gel electrophoresis. Since rare-cutting enzymes completely digested DNA at the middle of the N-myc gene, we were able to construct a physical map upstream and downstream of the germline N-myc gene, and to obtain information on restriction sites surrounding amplified N-myc genes. This method enables us to envisage the organization of amplified units over a long range. Digestion patterns differed considerably among the germline and the three cell lines, but were simple in each case. We estimated that the minimal distance between neighboring N-myc genes is at least several hundred kilobases. Our data suggest that amplification units contain several DNA fragments derived from different loci, but that they are homogeneous.

Base Sequence↗

Effects of external calcium, magnesium, and temperature on spontaneous contractions of pregnant human myometrium.

Spontaneous isometric contractions of small isolated segments from the isthmic region of pregnant human myometrium were recorded to clarify the characteristics of and influences of experimental conditions on contractions. There is a spontaneous periodicity in membrane activity of human myometrium, and contractions evoked with a sustained electric stimulus were affected by spontaneous rhythmic contractions. The frequency of contractions increased markedly, but their duration decreased when temperature of the bathing fluid was increased from 26 degrees C to 39 degrees C. Both excess (7 mM) and low (0.5 mM) calcium levels suppressed the generation of spontaneous contraction. Frequency and half-duration gradually decreased when external magnesium was increased from 0 mM to 3.6 mM. These results indicate that the pattern of contraction depends on the frequency of and intervals between each action potential, and that spontaneous contractility-particularly its frequency-is extremely sensitive to external temperature and ionic conditions.

Calcium↗

Enhancement of both intracellular uptake and antitumor action of cisplatinum on human neuroblastoma cells by encapsulation in liposomes.

Phospholipid vesicles (phosphatidylcholine:phosphatidylserine:cholesterol = 6:2:3 in molar ratio) with a small unilamellar structure were used as drug carriers for introducing cis-diamminedichloroplatinum (CDDP) into human neuroblastoma cells, IMR-32, GOTO, Nagai, and TGW. DNA synthesis of IMR-32 cells among the human neuroblastoma cell lines was inhibited most strongly by CDDP-liposomes. CDDP-liposomes dose-dependently inhibited the DNA synthesis of IMR-32 in a similar fashion to that observed with free CDDP, but the drug concentration required to induce 50% inhibition of DNA synthesis for CDDP-liposomes (IC50: 0.7 micrograms CDDP/ml) was 1/3 of the IC50 for free CDDP (2.0 micrograms CDDP/ml). In support of the marked growth-inhibitory action of CDDP-liposomes, the intracellular incorporation rate of CDDP-liposomes was 3-fold higher when liposomes were used as carriers than when free CDDP was directly applied. CDDP-liposomes showed a stronger growth inhibition on IMR-32 cells at a high cell density than at a low density in culture. CDDP-liposomes were rapidly incorporated by IMR-32 cells within 5 min, resulting in the inhibition of DNA synthesis to 40% of the control. Swiss albino mouse 3T3 cells were less inhibited by CDDP-liposomes than by free CDDP, suggesting that encapsulation of CDDP in liposomes decreases cytotoxicity to normal cells.

Biological Transport↗

Changes in serum calcium, magnesium, cyclic AMP and monoamine oxidase levels during pregnancy and under prolonged ritodrine treatment for preterm labor.

Changes in serum levels of calcium, magnesium, cAMP and monoamine oxidase (MAO) activity throughout pregnancy and during prolonged treatment for preterm labor with ritodrine were studied. cAMP levels in the third trimester of pregnancy were found to be significantly high and postpartum MAO activity was significantly low. In cases of preterm labor, serum levels of calcium, magnesium and MAO activity were significantly low during the initial stage of ritodrine administration, then recovered after more than 1 week of treatment despite the fact that given doses and serum levels of ritodrine remained constant and that the serum level of cAMP was still high. These results suggested that a control mechanism for MAO activity during pregnancy might exist due to an increase in catecholamine and that the beta 2-effect of ritodrine induced a lowering in serum calcium and magnesium levels. However, some homeostatic mechanism to regulate the ions might come into play later on the mechanism of down-regulation of ritodrine.

Adult↗