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Biomedical subjects

N Ishida

Publications and source records attributed to N Ishida.

At least 55 records · Page 3Linked to original sources
PubMed2001

Population study and validation of paternity testing for Thoroughbred horses by 15 microsatellite loci.

Microsatellite 15 TKY System was characterized for parentage verification of horse registry. The Microsatellite 15 TKY System was constructed by using 15 microsatellites, TKY279, TKY287, TKY294, TKY297, TKY301, TKY312, TKY321, TKY325, TKY333, TKY337, TKY341, TKY343, TKY344, TKY374, and TKY394, to provide stringent PCR-based microsatellite typing specifically optimized for multicolor fluorescence detection. The Microsatellite 15 TKY System showed good resolutions for 250 unrelated Thoroughbred horses, and the probability of exclusion (PE) at each microsatellite ranged from 0.437 to 0.621, resulting in a total PE value of 99.998% for Thoroughbred horses. These results indicated that the Microsatellite 15 TKY System is useful for paternity testing of Thoroughbred horses. A paternity testing case for a Thoroughbred horse family, in which candidate sires had close relations, was analyzed using the Microsatellite 15 TKY System. In this case, the Microsatellite 15 TKY System excluded paternity of a false sire. We concluded that the Microsatellite 15 TKY System can give sufficient and reliable information for paternity testing.

Animals↗
PubMed2001

Protective effect of PEG-SOD against early coronary reperfusion injury assessed in reperfused and non-reperfused ischaemic areas of the same heart.

OBJECTIVE: In order to investigate the salvage of ischaemic myocardium by polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), we compared reperfused and non-reperfused regions in the same canine heart and measured regional myocardial blood flow (RMBF) and myocardial CPK during coronary occlusion and reperfusion using non-radioactive, coloured microspheres. METHODS AND RESULTS: The chests of 17 mongrel dogs were opened under anaesthesia, and the left circumflex coronary artery was occluded for 90 min and then reperfused for 5 min. During this procedure, polystyrene microspheres of different colours were infused at four different times: prior to occlusion (orange), 10 min (red) and 90 min (blue) after occlusion, and 5 min after reperfusion (yellow). Thereafter, the heart was excised, cut in slices along the left circumflex coronary artery, and flow rates at the various times were assessed as a function of microsphere counts. In the control group (n=9), there are significant differences in the myocardial CPK level between reperfused and non-reperfused areas. The myocardial CPK level in reperfused area was significantly reduced compared to non-reperfused area in the outer layers (54 +/- 8 IU/g vs. 74 +/- 9 IU/g, P < 0.05), and also reduced in the inner layers (59 +/- 9 IU/g vs. 74 +/- 13 IU/g), however, it was not significantly different. In the PEG-SOD group (n=8), there was no significant difference in the myocardial CPK level between reperfused and non-reperfused areas in both inner and outer layers (inner layers; 68 +/- 11 IU/g vs. 68 +/- 6 IU/g, outer layer; 69 +/- 17 IU/g vs. 67 +/- 18 IU/g), indicating a significant protective effect of PEG-SOD. In the control group, transmural necrosis of the reperfused areas was 22.4 +/- 10.0%, which showed no significant difference compared with non-reperfused areas (23.1 +/- 9.9%). In the PEG-SOD group, transmural necrosis of the reperfused areas by TTC staining was 8.1 +/- 8.1%, which showed no significant difference compared with non-reperfused areas (8.5 +/- 7.1%). CONCLUSIONS: PEG-SOD prevents infarct extension during early coronary reperfusion.

Analysis of Variance↗
PubMed2001

Application of fluorescently labeled poly(dU) for gene expression profiling on cDNA microarrays.

The membrane filter hybridization technique has been widely used for gene expression profiling. The preparation of sensitive and reliable probes is critical for quantitative analysis in this technique. We report a method in which fluorescently labeled poly(dU) is used to detect poly(A)-containing mRNA that hybridizes to specific gene targets. The probe can be used commonly for every sample, alleviating problems encountered in preparing cDNA probes by reverse transcription, particularly when many samples are to be analyzed. Moreover, the sensitivity is at least comparable to cDNA probes prepared by conventional protocols, and intensities of signals after hybridization are independent of mRNA sizes and solely dependent on copy numbers. This method was also shown to be applicable to DNA chip technology.

Animals↗
PubMed2001

Time, love and species.

Physiological and behavioral phenomena of many animals are restricted to certain times of the day. Many organisms show daily rhythms in their mating. The daily fluctuation in mating activity of a few insects is controlled by an endogenous clock. The fruitfly, Drosophila, is the most suitable material to characterize the genetic basis of circadian rhythms of mating because some mutants with defective core oscillator mechanism, feedback loops, have been isolated. D. melanogaster wild-type display a robust circadian rhythm in the mating activity, and the rhythms are abolished in period or timeless null mutant flies (per(01) and tim(01)), the rhythms are generated by females but not males. Disconnected (disco) mutants which have a severe defect in the optic lobe and are missing lateral neurons show arrhythmicity in mating activities. Thus, the lateral neurons seem to be essential for the circadian rhythm in mating activity of Drosophila. Furthermore, an anti-phasic relation in circadian rhythms of the mating activity was detected between D. melanogaster and their sibling species D. simulans. The Queensland fruit flies or wild gypsy moth also show species-specific mating rhythm, suggesting that species-specific circadian rhythms in mating activity of insect appear to cause a reproductive isolation.

Animals↗
PubMed2001

[Mid-term results of triple valve operation].

UNLABELLED: From January 1995 to August 2000, 34 patients received the triple valve operation in our hospital. We evaluated the mortality, the cause of death, postoperative complications and mid-term results in these patients. Five-years'survival rate was determined by means of the Kaplan-Meire method. RESULTS: Two patient died after operation due to cardiac failure and cerebral infarction. Postoperativery, all patients had anticoagurant therapy with warfarin sodium. Mean follow-up was 3.2 years (0-5.6 years). There was one late sudden death among 32 perioerative survivors. There were 3 episodes of cerebral infarction. The rate of freedom from cardiac event at 5 years was 79%. Overall survival rate at 5 years was 94%. CONCLUSION: We obtained good mid-term results of triple valve operation. We recommend aggressive treatment for functional tricuspid valve regurgitation.

Aged↗
PubMed2001

Clinical studies of bioabsorbable poly-L-lactide sternal coaptation pins.

BACKGROUND: Median sternotomy has become the most commonly used incision in cardiac surgery. Since sternal dehiscence, however, is a major complication, we used bioabsorbable poly-L-lactide (P-L-LA) sternal coaptation pins for sternal closure to prevent it. METHODS: From February 1998 to October 1999, 99 patients (64 men, 35 women; mean age, 63+/-1.2 years) underwent median sternotomy for cardiac surgery using sternal coaptation pins. Nineteen patients had diabetes mellitus and seven had renal failure. In closure, two sternal pins were inserted into the bone marrow of the sternum, one into the manubrium, the other into the body, and the sternum was sutured with five stainless steel wires. RESULTS: Five patients died in the hospital. The causes of death were cardiac failure in two patients, respiratory problem in two and perforation of the stomach in one. The average length of hospitalization was 2 4.5+/-2.5 days. Sternal dehiscence occurred in one patient and mediastinitis in four. There was no bleeding from the bone marrow and no complication related to the use of the sternal pins. CONCLUSIONS: P-L-LA sternal pins were easy to insert and may be effective in preventing dehiscence of the sternum.

Absorbable Implants↗
PubMed2001

[Mid-term results of double valve (mitral-aortic) replacement for cases with poor LV function].

UNLABELLED: From March 1989 to July 2000, 82 patients have received the aortic-mitral replacement in our hospital. Among these patients, 11 patients had left ventricular ejection fraction less than 40%. We evaluated the mortality, the cause of death, postoperative complications and mid-term results of these patients. Five-years' survival rate was determined by means of the Kaplan-Meire method. Follow-up was complete for 100% of the patients. RESULTS: One patient (9%) died on 7 days after operation, due to multiorgan failure. Postoperativery, all patients had anticoagurant therapy with warfarin sodium and showed improvement in functional class. Mean follow-up was 3.4 years (0-5.9 years). The late death rate was 20% (2 patients). But there were no valve-related deaths during the follow-up periods. Overall survivals rate at 5 years was 70%. CONCLUSION: Despite the poor left ventricular function, we obtained satisfactory mid-term results of mitral-aortic valve operations.

Aged↗
PubMed2001

Ontogenetic changes of water states and structural organization in growing kidney beans: parameter-imaging based on the diffusion measurements.

Physical states of cell-associated water in growing kidney beans was studied by NMR microscopy. 1H-NMR images indicated the changes of water amount in the individual tissues. The seed gradually reduced water and water in the tissues of the pod varied according to growth stages. Images that reflect diffusive motion provide different contrast from that of the proton images; signal intensity was maintained in the tissues containing small amounts of water and showing weak signal on the proton images. These images are related to the activity of metabolism and physiological functions. The parameter-images provided the structural information about cellular matrix, the barrier spacing of water compartments and the reduced permeability of cell-membranes surrounding the compartment, were created based on the restricted diffusion of cell-associated water. The properties of the water compartment changed with the stages of growth in individual tissues of the fruits. Two types of water compartments were detected; one had approximately 65 microm spacing and constant permeability (20-25%) throughout the stages of growth, and another had the smaller and variable spacing (approximately 35 microm), and a lower permeability. The former belongs to the seed and the mesocarp, the exocarp and the epidermis of the pod. While the latter characterizes the properties of the primary tissue in the pod, the endocarp, which increased with development of the pod then showed reduction with the decrease of water in the pod with the fruit growth.

Biological Transport↗
PubMed2001

[Surgical repair of postinfarction ventricular septal perforation by endocardial patch with infarction exclusion].

UNLABELLED: We evaluated the surgical results of postinfarction ventricular septal perforation by endocardial patch with infarction exclusion. MATERIALS AND METHODS: We reviewed 8 patients complicating AMI who underwent surgical treatment at our institution from July 1997 to August 2000 (6 males, 2 females, mean age 73.9 +/- 9, range 57-87). The localization of AMI and VSP was anterior in 6 patients, inferior in 2. All patients had coronary angiography preoperatively. And 7 patients had the percutaneous transluminal coronary angioplasty of the infarct artery. RESULTS: There were 2 hospital deaths due to cerebral infarction and pulmonary hemorrhage. All deaths occurred in patients with cardiogenic shock. CONCLUSION: Good results were obtained by infarction exclusion technique. Better operative results may be expected with the preoperative coronary angioplasty of the infarct artery.

Aged↗
PubMed2000

Two circadian oscillatory mechanisms in the mammalian retina.

To investigate the mechanism that controls circadian rhythms in the mammalian retina, we examined the mRNA expression rhythms of serotonin N-acetyltransferase (NAT), the mammalian clock gene rPer2 and a clock-controlled gene Dbp in the retina of rats with lesions of the suprachiasmatic nucleus (SCN), the master clock in mammals. Northern blot analyses showed that retinal NAT mRNA still exhibited the circadian expression in the SCN-lesioned rats, whereas the lesion abolished the rhythms of rPer2 and Dbp mRNAs. These findings suggest that the mammalian retina has two circadian oscillatory mechanisms: one can generate rhythmicity independent of the SCN and the other requires the SCN to maintain circadian oscillation.

Animals↗
PubMed2000

Molecular characterization and nuclear localization of rat timeless-like gene product.

Among three period genes (per1, per2, per3) in mammals, only per2 gene was shown to be involved in the core clock mechanism. To elucidate the molecular function of rat PERIOD2 (rPER2), we searched for binding proteins to the PAS domain of rPER2. We isolated a binding protein to this domain and identified it as a TIMELESS-like protein (TLP) on the basis of mass analyses. Then, we isolated a rat TLP cDNA from the rat hypothalamus library. RNA blot analysis and in situ hybridization indicates that rTLP mRNA was expressed in all rat tissues from whole brain, the suprachiasmatic nucleus, eye, lung, heart, liver, kidney, placenta, and testis. When rTLP gene product was expressed in COS-1 cells, nuclear localization of rTLP was detected in 99.6% of transfected cells. These results suggest that the interaction of rPER2 with rTLP may influence the regulation of circadian clock components in nucleus after rPER2 is translocated into the nucleus.

Amino Acid Sequence↗
PubMed2000

The pineal gland is not essential for circadian expression of rat period homologue (rper2) mRNA in the suprachiasmatic nucleus and peripheral tissues.

To investigate the functional involvement of the pineal gland in circadian expression of the rat period homolog gene (rPer2) in the suprachiasmatic nucleus (SCN) and peripheral tissues, we performed Northern blot analysis in tissues from pinealectomized rats. The ectomy did not have any significant effects on rPer2 mRNA expression patterns both in a daily light-dark condition and in a constant darkness. These results suggest that the rhythmic secretion of pineal melatonin is not essential for the circadian expression of clock genes in the SCN and other peripheral tissues of rats.

Animals↗
PubMed2000

Phosphorylation at serine 10, a major phosphorylation site of p27(Kip1), increases its protein stability.

The association of the p27(Kip1) protein with cyclin and cyclin-dependent kinase complexes inhibits their kinase activities and contributes to the control of cell proliferation. The p27(Kip1) protein has now been shown to be phosphorylated in vivo, and this phosphorylation reduces the electrophoretic mobility of the protein. Substitution of Ser(10) with Ala (S10A) markedly reduced the extent of p27(Kip1) phosphorylation and prevented the shift in electrophoretic mobility. Phosphopeptide mapping and phosphoamino acid analysis revealed that phosphorylation at Ser(10) accounted for approximately 70% of the total phosphorylation of p27(Kip1), and the extent of phosphorylation at this site was approximately 25- and 75-fold greater than that at Ser(178) and Thr(187), respectively. The phosphorylation of p27(Kip1) was markedly reduced when the positions of Ser(10) and Pro(11) were reversed, suggesting that a proline-directed kinase is responsible for the phosphorylation of Ser(10). The extent of Ser(10) phosphorylation was markedly increased in cells in the G(0)-G(1) phase of the cell cycle compared with that apparent for cells in S or M phase. The p27(Kip1) protein phosphorylated at Ser(10) was significantly more stable than the unphosphorylated form. Furthermore, a mutant p27(Kip1) in which Ser(10) was replaced with glutamic acid in order to mimic the effect of Ser(10) phosphorylation exhibited a marked increase in stability both in vivo and in vitro compared with the wild-type or S10A mutant proteins. These results suggest that Ser(10) is the major site of phosphorylation of p27(Kip1) and that phosphorylation at this site, like that at Thr(187), contributes to regulation of p27(Kip1) stability.

3T3 Cells↗
PubMed2000

Activation of human CAII gene promoter by v-Src: existence of Ras-dependent and -independent pathways.

Carbonic anhydrase II (CAII) catalyzes the reversible hydration of carbon dioxide and plays key roles in acid base homeostasis in mammals. We found that human CAII gene promoter could be activated in human cells such as HeLa and T47D cells when the CAII promoter-luciferase gene was transfected with v-Src and assayed as a reporter of the promoter activity. Kinase negative mutants of Src, in contrast, showed little activation. The activation was completely suppressed with the introduction of a dominant-negative Ras in T47D cells, while no suppression was observed in HeLa cells. Introduction of various kinds of deletions into the CAII promoter revealed two essential regions responsible for this activation. No activation, however, was observed in activated Fyn-transfected human cells or in v-Src-transfected rodent cells. These findings suggest that Src can modulate the human CAII promoter by exerting its tyrosine kinase activity in certain human cells, and that two types of Src signaling pathways, Ras-dependent and -independent, exist in a cell type dependent manner.

Animals↗
PubMed2000

Synthesis of bis- and oligo-gem-difluorocyclopropanes using the olefin metathesis reaction

Synthesis of six types of novel bis- and oligo-gem-difluorocyclopropanes has been accomplished through the olefin metathesis reaction protocol. Two types of ruthenium-based olefin metathesis catalysts were tested: the ruthenium catalyst coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene and tricyclohexylphosphine ligands gave better results than the ruthenium catalyst that coordinated with two tricyclohexylphosphine ligands.

Journal Article↗
PubMed2000

Targeted disruption of Skp2 results in accumulation of cyclin E and p27(Kip1), polyploidy and centrosome overduplication.

The ubiquitin-proteasome pathway plays an important role in control of the abundance of cell cycle regulators. Mice lacking Skp2, an F-box protein and substrate recognition component of an Skp1-Cullin-F-box protein (SCF) ubiquitin ligase, were generated. Although Skp2(-/-) animals are viable, cells in the mutant mice contain markedly enlarged nuclei with polyploidy and multiple centrosomes, and show a reduced growth rate and increased apoptosis. Skp2(-/-) cells also exhibit increased accumulation of both cyclin E and p27(Kip1). The elimination of cyclin E during S and G(2) phases is impaired in Skp2(-/-) cells, resulting in loss of cyclin E periodicity. Biochemical studies showed that Skp2 interacts specifically with cyclin E and thereby promotes its ubiquitylation and degradation both in vivo and in vitro. These results suggest that specific degradation of cyclin E and p27(Kip1) is mediated by the SCF(Skp2) ubiquitin ligase complex, and that Skp2 may control chromosome replication and centrosome duplication by determining the abundance of cell cycle regulators.

Animals↗
PubMed2000

The prepro vasoactive intestinal contractor (VIC)/endothelin-2 gene (EDN2): structure, evolution, production, and embryonic expression.

Murine vasoactive intestinal contractor (VIC) and its human analog endothelin-2 (ET2) are potent vasoactive hormones composed of 21 amino acids. To study the structural characteristics of the VIC/ET2 gene (HGMW-approved symbol EDN2), we isolated the full length of the mouse VIC gene. Sequence analysis indicates that a biologically active mature VIC peptide is produced from a 175-residue precursor protein; preproVIC (PPVIC). Several remarkable similarities of the PPVIC gene to the human preproendothelin-1 gene strongly suggest that the two genes have arisen from a common progenitor by gene duplication. Transfection of ACHN adenocarcinoma cells with the cDNA resulted in the production of VIC peptide. VIC production was increased by the deletion of the 3'-untranslated region, which contains an AU-rich mRNA destabilizing sequence. Increased PPVIC gene expression during the late embryonic stage suggests an important function in development. This study provides the basis for disruption and regulation analysis of the gene, which may lead to a better understanding of VIC/ET2's physiological significance.

Amino Acid Sequence↗