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Biomedical subjects

S Nishimura

Publications and source records attributed to S Nishimura.

At least 199 records · Page 11Linked to original sources
PubMed1998

Effects of parent Shamo cocks on the histochemical properties of M. iliotibialis lateralis and M. supracoracoideus on their crossbred broilers.

1. Four Shamo (a Japanese game bird) cocks showing different characteristics in the histochemical properties of M. iliotibialis lateralis (ITL) were crossed with White Rock hens to produce male and female crossbred broilers of the 4 lines (90 d of age). Normal broilers (56 d) were used, for comparison. 2. Histochemical properties of ITL and M. supracoracoideus (SC) were compared among the crossbred lines and normal broilers. Myofibres were divided into Types II R, II I and II W showing high, moderate and low reduced nicotinamide adenine dinucleotide dehydrogenase (NADH-DH) activities, respectively. 3. In the ITL of the crossbred cockerels, the percentage of Type II R and II I fibres decreased and conversely Type II W increased in comparison to those in the Shamo. 4. Sex differences of the histochemical properties were recognised only in the ITL of the crossbred, in which the percentage of Type II R fibres was greater in the male. 5. The different characteristics of the parent Shamo cocks were reproduced only in the different fibre type composition of the ITL muscle in the crossbred cockerels. 6. The histochemical features of fibre type seemed to develop with bird age, particularly subsarcolemmal accumulation of formazan granules (indicating high NADH-DH activity) in Type IIR fibres. 7. Breed, line, sex and age differences in the histochemical properties were demonstrated clearly in ITL but not in SC.

Age Factors↗
PubMed1998

Body composition analysis of cachectic rabbits by total body electrical conductivity.

A simple formula (1.536 x TOBEC + 475.146 = LBM, where TOBEC is total body electrical conductivity and LBM is lean body mass) to estimate LBM in grams was developed on the basis of the total body fat data obtained by ether extraction and TOBEC in normal rabbits. The formula was also applicable to rabbits with cachexia induced by inoculation of VX2 carcinoma or by starvation. We were able to assess the losses of body fat in the rabbits with cachexia at 10-day intervals by using TOBEC.

Animals↗
PubMed1998

Oxidative refolding of bovine pancreatic RNases A and B promoted by Asn-glycans.

It was previously revealed [Yamaguchi, H. and Uchida, M. (1996) J. Biochem. 120, 474-477] that both intra- and extramolecular high-mannose type Asn-glycans promote the renaturation of reductively denatured bovine pancreatic RNases A and B under oxidation conditions. To characterize the conformational changes of the polypeptides during the renaturation promoted by the intramolecular Asn-glycans, RNase B was compared with its nonglycosylated form, RNase A, as to the features of the regeneration from their reductively denatured species under Cu2+-catalyzed oxidation conditions. The refolding intermediates of RNase B, as compared with those of RNase A, seemed to contain much less impaired disulfide linkages. In agreement with this finding, the proper refolding of RNase B was much faster than that of RNase A, as revealed by the intrinsic fluorescence and 1-anilino-8-naphthalenesulfonate binding of the refolding intermediates. Such a promoting effect was also observed for extramolecular Asn-glycans of the complex as well as of the high-mannose type. In contrast, common mono-, oligo-, and polysaccharides, but not yeast mannan, exhibited much lower stimulatory effects on the oxidative refolding of RNase A.

Anilino Naphthalenesulfonates↗
PubMed1998

Promotion of polypeptide folding by interactions with Asn-Glycans.

We have recently revealed that the intramolecular Asn-glycans promote the refolding of reductively denatured bovine pancreatic RNase B, and that extramolecular Asn-glycans of both high-mannose and complex types also markedly stimulate the oxidative refolding of RNase B and its nonglycosylated form, RNase A [Yamaguchi, H. and Uchida, M. (1996) J. Biochem. 120, 474-477; Nishimura et al. (1998) J. Biochem. 123, 516-520]. The present investigation was undertaken to see whether this function of Asn-glycans is specific to the refolding of pancreatic RNases; i.e., extramolecular Asn-glycans were examined for their effects on the oxidative refolding of hen egg white lysozyme and bovine alpha-lactalbumin by monitoring changes in activity, dynamic volume, intrinsic fluorescence, and affinity for a fluorescent probe, 1-anilino-8-naphthalenesulfonate. Asn-glycans of both high-mannose and complex types markedly stimulated the oxidative refolding of these proteins, giving similar results to those previously obtained with RNases, though differences attributable to the characteristics of individual proteins were observed in the promotive effects. Thus it seems probable that Asn-glycans generally promote the proper folding of denatured polypeptides.

Anilino Naphthalenesulfonates↗
PubMed1998

The development of sinoatrial dysfunction in pacemaker patients with isolated atrioventricular block.

The purpose of this paper is the assessment of sinus node competence over time in patients with isolated atrioventricular block (AV block). Patients implanted with AV synchronous pacemakers for isolated AV block between December 1993 and June 1995 were prospectively evaluated at predischarge, 6 weeks, and subsequent 6 months follow-up with respect to atrial rate monitors/24-hour Holter and modified exercise test. Patients unable to maintain AV synchronous pacing or complete a modified exercise test were excluded. Sinus node competency is interpreted as: (1) absence of atrial brady- or tachyarrhythmia, (2) ability to achieve a minimum heart rate of 100 beats/min with modified exercise test or during daily activities. There were 58 patients (22 women), mean age 71.0 +/- 13.8 with an average follow-up of 30.4 months (11-40). Three patients did not complete a modified exercise test, 4 patients were lost to follow-up, and 2 patients were unable to maintain AV synchronous pacing. Of the remaining 49 patients, 3 developed chronic or paroxysmal atrial fibrillation. No patient developed significant bradyarrhythmias. All patients achieved a heart rate of > or = 100 beats/min modified exercise test. In our group of patients with isolated AV block within a moderate follow-up period, development of sinoatrial dysfunction was rare (6%). A longer follow-up is required to delineate the natural history of sinoatrial dysfunction in patients with isolated AV block.

Aged↗
PubMed1998

When pacemakers fail: an analysis of clinical presentation and risk in 120 patients with failed devices.

Although pacemaker recalls are common, the optimal mechanism for risk assessment and triage of patients at risk for sudden loss of device system function is unknown. A retrospective chart review of 120 patients with factory proven failed devices was performed. Logistic regression analysis was used to determine clinical correlates of emergency room versus outpatient clinic presentation at time of device failure. Twenty-two patients (18%) presented to emergency and 98 (82%) to clinic. Sixty-three devices had no device output at the time of presentation. Multivariate logistic regression analysis revealed that antiarrhythmic drug use (odds ratio: 7.4, 95% CI: 2.0-28.0), atrioventricular nodal disease as an indication for pacing (odds ratio: 2.8, 95% CI: 1.2-3.0), and female gender (odds ratio: 2.2, 95% CI: 1.0-4.5) were the only significant correlates of emergency room presentations. Pacemaker dependency (escape heart rate < 40 beats/min) did not correlate with location of presentation even though no device output at the time of presentation was associated with emergency room presentation (odds ratio: 2.5, 95% CI: 1.1-5.8). Neither the presence of structural heart disease nor symptoms at the time of device implantation (syncope or presyncope) were correlated with location of presentation upon unexpected device failure. Although there were no deaths in the 120 failed devices studied, there were 26 deaths in the total group of 227 patients with recalled devices that could not be studied. Antiarrhythmic drug use, electrocardiographic pacing indication, and female gender may be more sensitive predictors of emergency room presentation and significant symptoms in the event of unanticipated pacemaker failure. The inability of any retrospective analysis to accurately assess mortality in the setting of pacemaker system failure underscores the need for prospective databases in recall situations.

Age Factors↗
PubMed1998

Circadian secretion patterns of melatonin after major surgery.

Biorhythms, such as regular variation in core body temperature and the pattern of the secretion of melatonin, are thought to be mediated by the same biological clock. Core body temperature is affected by the inflammatory response to major surgery. Apart from the well-known inhibitory effect of bright light on its secretion, melatonin is an exceedingly good marker of one of the central generating systems of circadian rhythms. We sequentially measured the plasma melatonin concentration pattern in patients who had undergone esophagectomy with thoracotomy to elucidate the circadian rhythm after major surgery. From seven patients who had received esophagectomy with thoracotomy for esophageal cancer, plasma concentrations of melatonin were measured using an RIA method. Blood samples were collected via each patient's arterial line at 00.00, 02.00, 04.00, 06.00, 08.00, 12.00, 16.00, 20.00, and 24.00 hr on the first postoperative day for six of the patients, and, for one patient, every 2 hr until the third postoperative day and every 4 hr thereafter until the sixth postoperative day. Four patients out of seven had melatonin concentrations of over 30 pg/ml (mean 34 pg/ml) at 24.00 hr on the first postoperative day. Five patients showed circadian secretion patterns of melatonin during the first postoperative day. One patient whose melatonin concentrations were measured consecutively for 6 days showed a regular circadian secretion pattern through the 6 days of the study. Even the stress caused by extremely invasive surgery did not significantly disturb the melatonin secretion pattern.

Aged↗
PubMed1998

J-104,871, a novel farnesyltransferase inhibitor, blocks Ras farnesylation in vivo in a farnesyl pyrophosphate-competitive manner.

Farnesylation of the activated ras oncogene product by protein farnesyltransferase (FTase) is a critical step for its oncogenic function. Because squalene synthase and FTase recruit farnesyl pyrophosphate as a common substrate, we modified squalene synthase (SS) inhibitors to develop FTase inhibitors. Among the compounds tested, a novel FTase inhibitor termed J-104,871 inhibited rat brain FTase with an IC50 of 3.9 nM in the presence of 0.6 microM farnesyl pyrophosphate (FPP), whereas it scarcely inhibited rat brain protein geranylgeranyltransferase-I or SS. The in vitro inhibition of rat brain FTase by J-104,871 depends on the FPP concentration but not on the concentration of Ras peptide. Thus, in vitro studies strongly suggest that J-series compounds have an FPP-competitive nature. J-104,871 also inhibited Ras processing in activated H-ras-transformed NIH3T3 cells with an IC50 value of 3.1 microM. We tested the effects of lovastatin and zaragozic acid A, which modify cellular FPP levels, on Ras processing of J-104,871. Lovastatin, a hepatic hydroxymenthyl coenzyme A reductase inhibitor that reduced the cellular FPP pool, increased the activity of J-104,871, whereas 3 microM zaragozic acid A, an SS inhibitor that raised the FPP level, completely abrogated the activity of J-104,871 even at 100 microM. These results suggest that J-104,871 inhibits FTase in an FPP-competitive manner in whole cells as well as in the in vitro system. Furthermore, J-104,871 suppressed tumor growth in nude mice transplanted with activated H-ras-transformed NIH3T3 cells.

3T3 Cells↗
PubMed1998

Power Doppler findings of adenoma malignum of uterine cervix.

Adenoma malignum (minimum deviation adenocarcinoma) is a rare neoplasma of the uterine cervix, the diagnosis of wich cannot be determined by cervical smear. Recently, magnetic resonance imaging (MRI) was reported as useful for its diagnosis, but differentiation of adenoma malignum from deep-seated nabothian cysts remains problematic. We report here a case of adenoma malignum of the uterine cervix, for which MRI findings could not neglect deep-seated nabothian cysts. However, transvaginal power Doppler ultrasonography clearly showed richness of small vessels, whose arterial flow had higher velocity in the diastolic phase, around the cystic lesion of the uterine cervix. These findings indicate that, at least in the case reported here, transvaginal power and pulsed Doppler ultrasonography is a useful tool for the diagnosis of adenoma malignum of the uterine cervix.

Adenocarcinoma↗
PubMed1998

Neural precursor cell chain migration and division are regulated through different beta1 integrins.

Proliferation and tangential migration of neural precursor cells are essential determinants of CNS development. We have established cell culture models of both these processes using neural precursor cells grown as neurospheres. The pattern of migration that we observe in these cells is homotypic and occurs in the absence of a glial or neuronal scaffold, and is therefore equivalent to that previously described as chain migration. To determine the role of integrins in proliferation and migration, we have analysed the expression pattern of integrins on neurosphere cells and then performed blocking peptide and antibody experiments. Neurosphere cells express five major integrins, alpha5 beta1, alpha 6Abeta1, alphav beta1, alphav beta5 and alpha vbeta8 and, in addition, express low levels of alpha 6Bbeta1. Chain migration is inhibited by blocking the alpha 6beta1 integrin. Proliferation, by contrast, is inhibited by blocking the other beta1 integrins, alphav beta1 and alpha5 beta1. These results show that integrins are important regulators of neural precursor cell behaviour, with distinct beta1 integrins regulating proliferation and migration. They also demonstrate a novel role for the alpha6 beta1 integrin in the cell-cell interactions underlying homotypic chain migration.

Animals↗
PubMed1998

Cloning of cDNA for a cell wall-bound acid invertase from tomato (Lycopersicon esculentum) and expression of soluble and cell wall-bound invertases in plants and wounded leaves of L. esculentum and L. peruvianum.

A cDNA, Wiv-1, for an isozyme of acid invertase (EC 3.2.1.26) was cloned from wounded leaves of tomato (Lycopersicon esculentum). The encoded protein had a basic isoelectric point and strong similarity to the amino acid sequences of plant cell wall-bound invertases. The conserved sequence WECPD that is found in all plant cell wall-bound invertases was also found in the deduced protein. These results suggested that Wiv-1 encoded a cell wall-bound acid invertase of tomato. Wounding increased the levels of mRNAs for soluble and cell wall-bound invertases and the activities of these invertases in leaves of L. esculentum and of a related species, L. peruvianum. The induction of Aiv-1 mRNA for the soluble enzyme in wounded leaves was not very strong, while that of Wiv-1 mRNA for the wall-bound enzyme was prominent. The level of Aiv-1 mRNA reached a maximum 48 h after wounding while that of Wiv-1 mRNA continued to rise for up to 96 h. These findings suggested that the genes for the two isozymes responded independently to wounding. The levels in various organs of Aiv-1 and Wiv-1 mRNAs were higher in L. esculentum than in L. peruvianum. Possible roles of cell wall-bound acid invertase in wound response and in developing plant are discussed.

Amino Acid Sequence↗
PubMed1998

Umbilical arterial flow change during hemodialysis.

A pregnant woman was performed hemodialysis 3 times a week from early gestation. At 30 weeks of gestation, fetal growth and amniotic fluid volume were normal. We performed 3-hour hemodialysis 6 times a week. Cesarean section was performed at 38 weeks of gestation, she delivered a healthy neonate weighing 2575 g. During hemodialysis, we performed Doppler flow velocimetry on the umbilical artery. The resistance index revealed a remarkable decrease after 1.5 hour hemodialysis. But it recovered 3 hours of administration as well as after completion of treatment. We speculated this change in the resistance index of the umbilical artery was caused by transient maternal hypovolemia.

Adult↗
PubMed1998

Acute myelomonoblastic leukemia carrying the PEBP2beta/MYH11 fusion gene.

As recurrent chromosome abnormalities in leukemia are highly associated with particular subtypes, the genetic events of specific chromosome alteration must be associated with leukemogenesis and characteristics of the disease. The chromosomal breakpoints involved in inv(16) and t(16;16) have been shown to generate the fusion gene PEBP2beta(CBFbeta)/MYH11. The PEBP2beta/MYH11 fusion transcripts in all 8 patients with M4Eo, 2 of 18 with M4, and one CML in the blastic phase were detected by using RT-PCR and Southern blotting. We demonstrated the marked expression of CD34 and c-KIT (CD117) antigens in myelomonoblastic leukemia cells from all patients carrying this fusion gene, which was in contrast to the patients with M4 but without the fusion gene. These results indicate that immunophenotypic analysis is useful for detection of leukemia with the fusion gene, and that the PEBP2beta/MYH11 fusion gene is involved in immature cells expressing CD34 and c-KIT antigens.

Artificial Gene Fusion↗
PubMed1998

Multiple appearing and vanishing aneurysms: primary angiitis of the central nervous system. Case report.

The authors present the case of a patient with ischemic episodes and recurrent intracerebral hemorrhages probably caused by primary angiitis of the central nervous system (CNS). An initial angiogram revealed multiple cerebral artery aneurysms as well as vascular wall irregularity; a second angiogram obtained 2 years later, however, did not demonstrate the previous aneurysms but instead showed new ones together with stenosis. Based on the histopathological findings and clinical course in this case, the multiple aneurysms appear to have been induced by vascular wall fragility and subsequent self-repair resulting from primary angiitis of the CNS. The authors present the histological and clinical characteristics of this unusual case of granulomatous, necrotizing CNS vasculitis.

Central Nervous System Diseases↗
PubMed1998

TGF-beta1 produced by gastric cancer cells affects mesothelial cell morphology in peritoneal dissemination.

In vitro morphologic change of mesothelial cells was observed following the addition of serum-free conditioned medium (SF-CM) from peritoneal dissemination cell line OCUM-2MD3. The same morphologic change of mesothelial cells was observed following the addition of 10 ng/ml TGF-beta1, but not following the addition of b-FGF, IGF-I, VEGF or PDGF-AA. In the in vivo study, mesothelial cells of mice treated with SF-CM from OCUM-2MD3 and TGF- beta1 were separated from one another, resulting in exposure of the submesothelial connective tissue. The molecular size of the mesothelial morphology changing activity was estimated by running the SF-CM from OCUM-2MD3 through a gel filtration column TSK-gel G2000SW. The mesothelial morphology changing activity was recognized at positions equivalent of Mr 6, 500-30,000. 25 kDa TGF-beta1 was detected in the active fraction from the TSK-gel G2000SW column and the SF-CM of OCUM-2MD3 by Western blotting using a monoclonal antibody against TGF-beta1. These findings suggest that TGF-beta1 produced by gastric cancer cells changes the morphology of mesothelial cells and may thus be closely associated with peritoneal dissemination.

Animals↗
PubMed1998

Tranilast and cisplatin as an experimental combination therapy for scirrhous gastric cancer.

We examined the effect of Tranilast on the reduction of the administered dose of cisplatin using a scirrhous gastric cancer model. Scirrhous gastric cancer cell line, OCUM-2M, and gastric fibroblasts, NF-10, were used. The IC50 values of CDDP to OCUM-2M cells were decreased by Tranilast in vitro. The combination treatment with Tranilast and CDDP decreased the xenografted tumor size. The combination therapy decreased fibrosis and mitosis, and increased apoptosis. These findings suggest that Tranilast increased the CDDP response on scirrhous gastric cancer. The combination treatment with Tranilast and CDDP may be useful as a new therapy for scirrhous gastric carcinoma.

Adenocarcinoma, Scirrhous↗