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Biomedical subjects

Y Hosoi

Publications and source records attributed to Y Hosoi.

At least 73 records · Page 4Linked to original sources
PubMed1996

[A case report of multiple pseudoaneurysms of the left ventricle following acute myocardial infarction].

Multiple pseudoaneurysms of the left ventricle following acute myocardial infarction were successfully repaired in a 50-year-old man. Three days after onset of acute myocardial infarction, we electively performed PTCA on the right coronary artery which was completely occluded at the proximal segment. One month after PTCA, the left ventriculogram revealed multiple pseudoaneurysms of the left ventricle. Primary closure of orifices of the pseudoaneurysms was performed using pledgeted mattress sutures under cardiopulmonary bypass. Histology of aneurysm confirmed the diagnosis of pseudoaneurysm.

Aneurysm, False↗
PubMed1995

Embryo culture in explanted oviducts in mice and cattle.

Developmental block of early embryos is due to the lack of some components in the culture medium and/or caused by inappropriate environmental conditions for embryonic development. It was shown in our experiments that the development of mouse and bovine embryos under the influence of oviducts in vitro can provide us with a model to analyze the oviductal factors that promote embryonic development. In the first experiment, it was shown that mouse zygotes developed to the blastocyst stage when a coculture system with ampulla was applied, and the duration of embryo coculture significantly affected the further development of embryos. In the second experiment, it was shown that the proportion of blastocysts of cleaved ova obtained after coculture with mouse ampulla was significantly higher than that obtained after coculture with a granulosa cell monolayer or culture without cells.

Animals↗
PubMed1995

Non-destructive elemental analysis of vertebral body trabecular bone using muonic X-rays.

Non-destructive elemental analysis with muonic X-rays was performed on human vertebral bone and lumbar torso phantoms. It can provide quantitative information on all elements in small deep-seated localized volumes. The experiment was carried out using the superconducting muon channel at TRIUMF in Vancouver, Canada and a lithium drifted germanium detector with an active area of 18.5 cm2. The muon channel produced backward-decayed negative muons with wide kinetic energy range from 0.5 to 54.2 MeV. The muon beam was collimated to a diameter of 18 mm. The number of incoming muons was about 4 x 10(6) approximately 5 x 10(7) per data point. In the measurements with human vertebral bones fixed with neutralized formaldehyde, the correlation coefficient between calcium content measured by muons and by atomic absorption analysis was 0.99 and the level of significance was 0.0003. In the measurements with lumbar torso phantoms, the correlation coefficient between calcium content measured by muons and by atomic absorption analysis was 0.99 and the level of significance was 0.02. The results suggest that elemental analysis in vertebral body trabecular bone using muonic X-rays closely correlates with measurements by atomic absorption analysis.

Adolescent↗
PubMed1995

Tissue- and development-specific expression of goat insulin-like growth factor-I (IGF-I) mRNAs.

We cloned four kinds of goat insulin-like growth factor-I (IGF-I) cDNAs. Each of them encodes the same mature IGF-I and different signal peptides. In this study, we analyzed expression of the four kinds of mRNAs in tissues in various developmental stages by a reverse transcriptase-polymerase chain reaction assay. The results suggest that their expression may be controlled by different promoters, the activities of which are tissue- and development-specific.

Animals↗
PubMed1995

Enhanced mitogen-induced proliferation of rat splenocytes by low-dose whole-body X-irradiation.

To elucidate the stimulative effect on the immune system, we studied the effect of acute low-dose whole-body X-irradiation on the mitogen-induced proliferative responses of rat splenocytes and thymocytes. Concanavalin A (Con A)-induced mitogen response of rat splenocytes 4 hours after 5 cGy irradiation was significantly higher (by 80%, p < 0.02) than that in sham-irradiated controls; whereas that of rat thymocytes did not show change after irradiation of 1-10 cGy. In the rats X-irradiated with doses greater than 25 cGy, Con A-induced mitogen responses of splenocytes and thymocytes were reduced. In a way similar to the Con A-induced mitogen response of splenocytes, the mitogen response of splenocytes induced by phytohemagglutinin (PHA) or lipopolysaccharide (LPS) was significantly increased by X-irradiation with 5 cGy (by 50%, p < 0.02). The enhancement of mitogen response of splenocytes was observed within a few hours after irradiation, being a temporary effect. After 5 cGy irradiation the level of leukotriene B4 (LTB4) in the supernatant fraction of the splenocyte suspension showed a significant increase (by 40%, p < 0.05).

Animals↗
PubMed1995

[A case of successful surgical treatment of recrudescent stanford type A aortic dissection after early thrombogenic closure and reduction of dissecting lumen].

A 51-year-old woman was admitted with acute chest and back pain. A CT scan (2 hours after onset) was demonstrated acute type A aortic dissection. The dissecting lumen was already closed with thrombus. A DSA was performed. It showed no intimal tear and a normal aortic figure. Repeat CT (5 hours after onset) was performed. It showed reduction of dissecting lumen compared with previous CT. Although medical treatment was continued, she recomplained intermittent slight chest and back pain. On the sixteenth day after her admission, repeat CT revealed recrudescent dissection and opened dissecting lumen of ascending aorta. Graft replacement was successfully performed using circulatory arrest and retrograde cerebral perfusion. She was discharged in good health.

Acute Disease↗
PubMed1995

[Comparison of long-term clinical results of the three models of the Björk-Shiley valve prosthesis and the Omnicarbon valve prosthesis].

A multi-institutional cooperative study, that was a comparison of long-term results of the replacement of the four models of the oblique disc valve prosthesis which had been implanted on aortic and mitral position alone or double from December 1976 to September 1992 in the eight national hospitals in Japan was performed. Seven hundred and thirty-four patients and 765 prostheses that consisted of 582 patients and 610 prostheses of the Björk-Shiley (BS) valve, including 326 patients of the Spherical disc (SP) valve (49 aortic, 259 mitral, and 18 double aortic-mitral), 103 patients of the Convexoconcave disc (CC) valve (45, 51, 7) and 153 patients of the Monostrut (MS) valve (101, 49, 3), and of 152 patients (71, 78, 3) and 155 prostheses of the Omnicarbon (OC) valve were compared with their mortality and morbidity in every valve position respectively according to the approval by STS-guideline. The MS valve and the OC valve showed 0% to 11.3% of operative mortality, 0.3%/py to 1.8%/py of valve related mortality, 85.5% +/- 5.6% to 98.4% +/- 1.6% of actuarial survival rate at 10 years, and 58.5% +/- 6.4% to 82.7% +/- 5.7% of actuarial free rate of all mortality and morbidity at 10 years in every valve position. Structural deteriorations occurred in two patients of the CC valve in the mitral position only, and its rate of all valve positions showed 0.04%/py. Significant differences were seen in actuarial survival rate at 10 years after aortic valve replacement, and in operative mortality rate, improved degree of NYHA class, structural deterioration rate and actuarial free rate of all mortality and morbidity after mitral valve replacement between the group of the MS and OC valve and the group of the SP and CC valve. Therefore the MS valve or the OC valve should be selected to implant rather than the SP valve or the CC valve, and the patient who had been implanted with the CC valve should be treated considering valve position, valve position, valve size, age and activity of the patient and the manufactured date of the prosthesis.

Bioprosthesis↗
PubMed1994

Differential expression patterns of mRNAs for members of the fibroblast growth factor receptor family, FGFR-1-FGFR-4, in rat brain.

We have examined the region-specific expression of mRNAs for four members of rat FGF receptor family, FGFR-1, FGFR-2 FGFR-3, and FGFR-4, in rat brain by in situ hybridization. The FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but differentially in the brain. However, the FGFR-4 mRNA was not expressed in the brain. The FGFR-1 mRNA was strongly expressed in several regions including the hippocampus, cerebellum, and pedunculopotine tegmental nucleus. The FGFR-2 mRNA expression was high in the choroid plexus, and moderate in the fiber-rich regions (the corpus callosum, external capsule, and internal capsule) and the olfactory bulb. The FGFR-3 mRNA was expressed diffusely in the brain. We have also examined the cellular localization of these mRNAs in the brain. Although the FGFR-1 mRNA was expressed preferentially in neurons, the FGFR-2 and FGFR-3 mRNAs were expressed preferentially in glial cells. The present findings that the FGFR-1, FGFR-2, and FGFR-3 mRNAs were expressed widely but with region- and cell-specificity in the brain indicate that these receptors have different roles in the brain.

Amino Acid Sequence↗
PubMed1994

In situ hybridization study of mu- and kappa-opioid receptor mRNAs in the rat spinal cord and dorsal root ganglia.

Distributions of mu- and kappa-opioid receptor mRNAs in the lumbar spinal cord and dorsal root ganglia of the adult rat were examined using the in situ hybridization technique. In the lumbar spinal cord, mu-opioid receptor mRNA was expressed intensely in laminae I, II and VIII. On the other hand, kappa-opioid receptor mRNA was expressed intensely in laminae I and II, and moderately throughout laminae III-VIII. In the dorsal root ganglia, mu-opioid receptor mRNA was intensely expressed and kappa-opioid receptor mRNA was expressed in a smaller number of cells than mu-opioid receptor mRNA.

Animals↗
PubMed1994

Molecular cloning and in situ hybridization histochemistry for rat mu-opioid receptor.

We cloned a cDNA for the rat mu-opioid receptor from a rat thalamus cDNA library. The deduced amino-acid sequence of rat mu-opioid receptor consists of 398 residues with the features shared by the members of the G-protein coupled receptor family, and is 59% and 60% identical with those of rat kappa-opioid and mouse delta-opioid receptors, respectively. Northern blot analysis showed that expression of mu-opioid receptor mRNA was intensive in the thalamus, striatum, hypothalamus and pons-medulla, moderate in the hippocampus and midbrain, and slight in the cerebral cortex and cerebellum. More detailed distribution of the mRNA in the rat brain was examined using the in situ hybridization technique. Intense expression of mu-opioid receptor mRNA was observed in the internal granular and glomerular layers of the olfactory bulb, caudate putamen, nucleus accumbens, medial septum, diagonal band, medial preoptic area, several nuclei of thalamus, amygdala, interpeduncular nucleus, medial raphe nucleus, inferior colliculus, parabrachial nucleus, locus coeruleus, nucleus solitary tract and ambiguus nucleus. Furthermore, mu-opioid receptor mRNA was moderately expressed in the hippocampus, globus pallidus, ventral pallidus, arcuate hypothalamic nucleus, supramammillary nucleus, superior colliculus, periacqueductal gray, and several nuclei of lower brain stem, including raphe magnus nucleus, reticular gigantocellular nucleus and lateral paragigantocellular nucleus.

Animals↗
PubMed1994

Inhibition of gonadotrophin-induced ovulation in rabbits by perfusion with dibutyryl cAMP via reduction of ovarian prostaglandin production.

The role of cAMP in ovulation, oocyte maturation and prostaglandin production was assessed using a rabbit ovary preparation perfused in vitro. Dibutyryl cAMP (10(-3), 10(-4) or 10(-5) mol l-1) was added to the perfusate of one ovary. The contralateral, control ovary was perfused with medium alone. Thirty minutes after the onset of perfusion, 50 iu hCG was added to the perfusate of all ovaries. Dibutyryl cAMP inhibited hCG-induced ovulation in a dose-related fashion. No difference in ovum maturity or degeneration was found between control ovaries and ovaries treated with dibutyryl cAMP. Ovarian progesterone production was not affected by exposure to dibutyryl cAMP. The concentrations of 6-keto PGF1 alpha (the stable metabolite of prostacyclin) and PGF2 alpha in the perfusate of ovaries treated with dibutyryl cAMP were 49.6% and 32.0% of the control values, respectively, 12 h after hCG administration. Inhibition of 6-keto PGF1 alpha production by dibutyryl cAMP was dose related. Production of PGE2 was unaffected by dibutyryl cAMP. These data raise the possibility that continuous exposure to dibutyryl cAMP may inhibit hCG-induced ovulation in the perfused rabbit ovary via a reduction in PGF2 alpha and prostacyclin production.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Expression of a candidate ataxia-telangiectasia group D gene in cultured fibroblast cell lines and human tissues.

A candidate gene for ataxia-telangiectasia group D (ATDC) has been cloned (Kapp et al. 1992), sequenced and found to be a member of a recently reported gene family (Leonhardt et al. 1994). Transcriptional behaviour of ATDC has been examined in a number of cell lines and human tissues using a 3.0 kb cloned cDNA as a probe. Three normal and two ataxia-telangiectasia (A-T) group D, non-transformed fibroblast cell lines produced a 2.4 kb mRNA transcript. The size of mRNA transcripts seen and the level of expression differ in different human tissues. Many tissues have multiple transcripts of ATDC and the most prominent transcripts observed were 3.0, 2.4 and 1.6 kb. Two out of three SV-40 transformed normal and one SV-40-transformed A-T group D fibroblast cell lines demonstrated no transcription of ATDC by RNA blotting analysis. These results suggest that SV-40 transformation may affect the expression of ATDC. Reverse transcription-polymerase chain reaction analysis showed that ATDC was expressed at low levels in all of these cells. Additional Northern blot analysis demonstrated that X-irradiation with 10 Gy had no effect on ATDC expression at 1, 4 and 24 h after irradiation in either SV-40-transformed normal or in SV-40-transformed A-T group D fibroblast cell lines. Further understanding of ATDC will require cloning of additional transcripts and studies of ATDC protein behaviour.

Ataxia Telangiectasia↗
PubMed1994

[Successful surgical correction of endocardial cushion defect in a 64-year-old female patient].

We have experienced a surgical correction of ECD of a 64-year-old female patient. The preoperative left ventriculogram showed typical goose-neck deformity of the left ventricle and mild mitral regurgitation. The correction consisted of repair of the mitral cleft, and patch closure of the ostium primum. Postoperative course was uneventful. The operation of ECD should be recommended even in an older patient.

Cardiac Catheterization↗
PubMed1994

[Surgical removal of right atrial myxoma in the elderly].

We have experienced a surgical treatment of right atrial myxoma in a 76-year-old woman. The patient was admitted with complaints of palpitation and low grade fever. Echocardiography revealed the atrial tumor, which prolapsed into the right ventricle in diastole. The tumor was removed under cardiopulmonary bypass including the atrial septum where it was attached. The tumor weighed 68 g and showed typical pathological findings of myxoma. The patient is doing well 6 years after surgery.

Aged↗
PubMed1993

In situ hybridization study of kappa-opioid receptor mRNA in the rat brain.

Distribution of kappa-opioid receptor mRNA in rat brain was examined by in situ hybridization technique. kappa-Opioid receptor mRNA was expressed in various brain regions, especially intensely in the neocortex (layer V and VI), caudate-putamen, nucleus accumbens, preoptic area, paraventricular thalamic nucleus, amygdala, several nuclei of hypothalamus, ventral tegmental area and substantia nigra pars compacta.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1993

Suppressive effect of low dose total body irradiation on lung metastasis: dose dependency and effective period.

The dose dependency and effective period of suppressive effects by low dose total body irradiation (TBI) in both artificial and spontaneous lung metastasis were investigated using murine squamous cell carcinoma. In the artificial lung metastasis of the tumour cells injected through a tail vein, the TBI of 0.15-0.20 Gy resulted in significant net suppression of lung colony formation. With this dose range, the effective period lasted for 12 h ranging from 9 h before to 3 h after the tumour cell injection. Similar suppressive effect was also observed in the spontaneous lung metastasis. These data suggest that careful assessment of effective dose and duration of low dose TBI on human metastasis could provide a new therapy to suppress clinical metastasis.

Animals↗
PubMed1993

Prostacyclin production in cultured endothelial cells is highly sensitive to low doses of ionizing radiation.

In an attempt to detect if low doses of ionizing radiation affect the physiological function of blood vessels, the effect of prostacyclin production was examined using cultured endothelial cells. Irradiation with 5 cGy suppressed the production to 53% of the levels in unirradiated control cells. The PGI2 production decreased with an increase in the dose, showing a maximal decrease at 100 cGy without further decrease at 200 cGy. The suppressive effect lasted for 15 min after irradiation and disappeared later. Preincubation with alpha-tocopherol abrogated the suppressive effect completely, although preincubation with ascorbic acid showed little effect. These results suggest that low dose irradiation inhibits the prostacyclin production by changing the cellular membranes transiently.

Animals↗