Search PubMed⌕ Search

Biomedical subjects

Y Matsui

Publications and source records attributed to Y Matsui.

At least 217 records · Page 12Linked to original sources
PubMed1996

Differences between 99mTc-DTPA and 99mTc-MAG3 captopril renographies in renovascular hypertension.

Captopril renography (CRS) with 99mTc-DTPA and 99mTc-MAG3 was performed on a 21-year-old woman with renovascular hypertension due to right renal artery stenosis caused by fibromuscular dysplasia. In the affected kidney, the renogram pattern was substantially changed with 99mTc-DTPA and 99mTc-MAG3 following the administration of captopril, and the quantitated renal uptake indicating individual renal function was significantly decreased in 99mTc-DTPA and slightly decreased in 99mTc-MAG3. In the contralateral normal kidney, the renogram showed some minor changes with both radioagents, while the quantitated renal uptake was significantly decreased with 99mTc-DTPA and substantially increased with 99mTc-MAG3. The combined use of physiologically different renal agents 99mTc-DTPA and 99mTc-MAG3 is helpful in investigating hemodynamic and functional changes in the stenosed kidney as well as the normal kidney in RVH.

Adult↗
PubMed1996

Progressive degeneration of articular cartilage and intervertebral discs. An experimental study in transgenic mice bearing a type IX collagen mutation.

Transgenic mice expressing mutant alpha 1(IX) collagen were produced and found to develop progressive joint degeneration with age, as well as accelerated intervertebral disc degeneration. Radiological and histological studies showed that cervical and lumbar disc degeneration was more advanced in the transgenic mice than in control litter-mates. The changes included shrinkage or disappearance of the nucleus pulposus, and fissures in the annulus fibrosus which sometimes lead to herniation of disc material and slight osteophyte formation. These findings suggest that mutations of the type IX collagen may cause certain forms of degenerative disease in the spine as well as in joints.

Animals↗
PubMed1996

Occurrence of Borrelia garinii oculo-neuroborreliosis in Japan.

We report a 64-year-old Japanese man with oculo-neuroborreliosis. His clinical features consisted of polyarthralgia, keratoconjunctivitis, chorioretinitis, optic neuritis, confusion, and polyradiculitis. Assay of antibodies to Borrelia species detected IgG-antibody to B. garinii in both serum and CSF. Progressive declining of serum IgG antibody titer against Borrelia garinii, in parallel with clinical improvement, was observed after administration of ceftriaxone.

Aged↗
PubMed1996

Masticatory function of postoperative tumor patients rehabilitated with osseointegrated implants.

PURPOSE: This study determined the level of masticatory function that can be achieved with osseointegrated implants in postoperative tumor patients. PATIENTS AND METHODS: Masticatory function was evaluated in 15 postoperative tumor patients with implants, 22 nontumor patients with implants, and 15 natural dentate controls. The area of occlusal contact was evaluated with a pressure-sensitive, color-developing bite sheet analyzed by computer. Chewing performance was evaluated by a low-adhesive, color-developing, chewing-gum system. RESULTS: Subjects in the tumor group had load-bearing tooth contacts similar to those of the natural dentate controls and nontumor implant patients. Continuity of the mandible was essential to sustain occlusal load. The presence of the hypoglossal nerve was the main factor in determining restoration of chewing performance. CONCLUSIONS: Surgical efforts to preserve the mobility of the residual tongue and prosthetic approaches to restore impaired mobility to as great an extent as possible are especially important for better functional rehabilitation of patients who have defects of the hypoglossal nerve.

Adult↗
PubMed1996

Yeast src homology region 3 domain-binding proteins involved in bud formation.

The yeast protein Bem1p, which bears two src homology region 3 (SH3) domains, is involved in cell polarization. A Rho-type GTPase, Rho3p, is involved in the maintenance of cell polarity for bud formation, and the rho3 defect is suppressed by a high dose of BEM1. Mutational analysis revealed that the second SH3 domain from the NH2 terminus (SH3-2) of Bem1p is important for the functions of Bem1p in bud formation and in the suppression of the rho3 defect. Boi2p, which bound to SH3-2 Bem1p, was identified using the two-hybrid system. Boi2p has a proline-rich sequence that is critical for displaying the Boi2p-Bem1p two-hybrid interaction, an SH3 domain in its NH2-terminal half, and a pleckstrin homology domain in its COOH-terminal half. A BOI2 homologue, BOI1, was identified as a gene whose overexpression inhibited cell growth. Cells overexpressing either BOI1 or BOI2 were arrested as large, round, and unbudded cells, indicating that the Boi proteins affect cell polarization. Genetic analysis revealed that BOI1 and BOI2 are functionally redundant and important for cell growth. delta boi1 delta boi2 cells became large round cells or lysed with buds, displaying defects in bud formation and in the maintenance of cell polarity. Analysis using several truncated versions of BOI2 revealed that the COOH-terminal half, which contains the pleckstrin homology domain is essential for the function of Boi2p in cell growth, while the NH2-terminal half is not, and the NH2-terminal half might be required for modulating the function of Bem1p. Overproduction of either Rho3p or the Rho3p-related GTPase Rho4p suppressed the boi defect. These results demonstrate that Rho3p GTPases and Boi proteins function in the maintenance of cell polarity for bud formation.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Separable cis-regulatory elements that contribute to tissue- and site-specific alpha 2(XI) collagen gene expression in the embryonic mouse cartilage.

Type XI collagen is a structural component of the cartilage extracellular matrix and plays an important role in skeletal morphogenesis. As a step toward defining the molecular mechanisms responsible for the regulation of type XI collagen expression, we characterized the promoter region of the mouse alpha 2(XI) collagen gene (Coll1a2). We also generated transgenic mice harboring various fragments of the promoter and the first intron of Coll1a2 linked to the Escherichia coli beta-galactosidase gene to identify the cis-acting elements responsible for tissue- and site-specific expression during development. Cloning and sequence analysis of the 5' flanking region of Coll1a2 showed that the putative 3' end of the retinoid X receptor beta gene was located 742 bp upstream of the Coll1a2 start site. This suggested that the promoter region of Coll1a2 was localized within this 742-bp sequence, which contained multiple consensus regulatory elements. Examination of the transgenic mice revealed that the longest DNA construct (containing the entire promoter and first intron sequences) directed lacZ expression in the notochord as well as in the primordial cartilage throughout the body, with the pattern of expression mimicking that of endogenous Coll1a2 transcripts. On the other hand, deletion of the upstream approximately 290 bp resulted in the elimination of lacZ expression in the primordial cartilage of the carpals, tarsals, and vertebral bodies, whereas lacZ expression in the notochord and in the other primordial cartilage elsewhere was not affected. Deletion of the first intron sequence also resulted in the loss of lacZ expression in the primordial cartilage of the carpals, tarsals, and vertebral bodies, as well as in the notochord. These results demonstrate that the upstream 742-bp and first intron segments of the mouse Coll1a2 gene contain the necessary information to confer high level tissue-specific expression in mouse embryos. In addition, our observations suggest the presence of site-specific cis-acting elements that control Coll11a2 gene expression in different cartilaginous components of the skeleton.

Animals↗
PubMed1996

Genetic analysis of the Saccharomyces cerevisiae RHO3 gene, encoding a rho-type small GTPase, provides evidence for a role in bud formation.

RHO3 encodes a Rho-type small GTPase of the yeast Saccharomyces cerevisiae. We isolated temperature-sensitive alleles and a dominant active allele of RHO3. Ts- rho3 cells lost cell polarity during bud formation and grew more isotropically than wild-type cells at nonpermissive temperatures. In contrast, cells carrying a dominant active mutant RHO3 displayed cold sensitivity, and the cells became elongated and bent, often at the position where actin patches were concentrated. These phenotypes of the rho3 mutants strongly suggest that RHO3 is involved in directing the growing points during bud formation. In addition, we found that SRO6, previously isolated as a multicopy suppressor of rho3, is the same as SEC4. The sec4-2 mutation was synthetic lethal with temperature-sensitive rho3 mutations and suppressed the cold sensitivity caused by a dominant active mutant RHO3. The genetic interactions between RHO3 and SEC4, taken together with the fact that the Rab-type GTPase Sec4p is required to fuse secretory vesicles together with plasma membrane for exocytosis, support a model in which the Rho3p pathway modulates morphogenesis during bud growth via directing organization of the actin cytoskeleton and the position of the secretory machinery for exocytosis.

Amino Acid Sequence↗
PubMed1996

The evaluation of masticatory function with low adhesive colour-developing chewing gum.

Many objective methods have been described to evaluate masticatory function. Recently, a new chewing gum system has been reported that utilizes a phloxine-sodium bicarbonate reaction and measures a chromatic coordinate as a functional indicator. A low-adhesive colour-developing chewing gum has been developed by selecting an appropriate gum base. This study examined the applicability of the system and reproducibility of results in subjects with different dental states. Tests were performed on 15 natural dentate subjects and 15 complete denture wearers after determination of germane test conditions through a pilot study. The colour was measured by a*, one of the coordinates in the L*a*b* colour system. All subjects could perform the test. The coefficient of variation ranged from 1.87% to 7.90%, averaging 5.15% in the natural dentate subjects and from 1.5% to 17.9%, averaging 9.75% in the complete denture wearers. The 95% confidence interval of a* was 28.76 +/- 1.76 in the natural dentate subjects and 10.05 +/- 2.58 in the complete denture wearers. The results indicated that this material can be useful for both complete denture wearers and subjects with a natural dentition with adequate reproducibility.

Adhesives↗
PubMed1996

A computerized method for evaluating balance of occlusal load.

In order to undertake a quantitative evaluation of balance occlusal load, the use of the Dental Prescale System was investigated. The method uses a test sheet that undergoes a colour-developing chemical reaction, for detecting contact area, and a computerized analysis system, for evaluating the balance of occlusal load. Twenty natural dentate subjects and 10 hemimaxillectomy patients participated in the study. Each subject bit a test sheet as hard as possible for 3 s. The balance of occlusal load was expressed as a percentage of the load on the side with the lesser occlusive load (%OLR). The %OLR ranged from 39.7% to 49.4% in the natural dentate subjects, and from 0% to 31.3% in the hemimaxillectomy patients at their resection site. The patients' low %OLRs were attributed to loss of sustaining structure and subjective occlusal adjustment by clinicians. Combining technical simplicity, relatively high reproducibility, and diverse analysis capability, this system is useful for quantitative evaluation of balance of occlusal load in clinical situations.

Adult↗
PubMed1996

Hepatocyte volume as an indicator of hepatic functional reserve in cirrhotic patients with liver tumours.

Using computed tomography (CT), measurements of whole liver volume have been used for the assessment of pre-operative functional reserve in cirrhotics. However, measurements of hepatocyte volume, which exclude stromal fibrous tissue, are considered to more directly reflect hepatic functional reserve. We investigated the relationship between total hepatocyte volume and each of the parameters of conventional liver function. Indocyanine green (ICG) tests and blood analyses for the assessment of liver function were performed prior to surgery in cirrhotic patients with liver tumours. Pre-operative liver volume was determined by integrating images of each liver area obtained by CT. Liver area was measured by an image processing program that traced the profile of the liver image while excluding the tumorous area. Sections of normal tissue stained by the haematoxylin-eosin method, were obtained from the resected liver. Using these sections, a hepatocyte area: whole tissue area ratio was calculated using the image processing program, by tracing the profiles of the hepatocyte nodules. The total volume of hepatocytes was then calculated by multiplying the liver volume by this ratio. The hepatocyte volume per unit bodyweight was significantly correlated with ICG tests and with many other parameters of normal liver function. However, the liver volume per unit bodyweight was correlated only with the plasma ICG disappearance rate and with the blood platelet count. These observations suggest that the functional reserve of the cirrhotic liver is assessed more precisely by hepatocyte volume than by liver volume.

Adult↗
PubMed1996

Identification of the bud emergence gene BEM4 and its interactions with rho-type GTPases in Saccharomyces cerevisiae.

The Rho-type GTPase Cdc42p is required for cell polarization and bud emergence in Saccharomyces cerevisiae. To identify genes whose functions are linked to CDC42, we screened for (i) multicopy suppressors of a Ts- cdc42 mutant, (ii) mutants that require multiple copies of CDC42 for survival, and (iii) mutations that display synthetic lethality with a partial-loss-of-function allele of CDC24, which encodes a guanine nucleotide exchange factor for Cdc42p. In all three screens, we identified a new gene, BEM4. Cells from which BEM4 was deleted were inviable at 37 degrees C. These cells became unbudded, large, and round, consistent with a model in which Bem4p acts together with Cdc42p in polarity establishment and bud emergence. In some strains, the ability of CDC42 to serve as a multicopy suppressor of the Ts- growth defect of deltabem4 cells required co-overexpression of Rho1p, which is an essential Rho-type GTPase necessary for cell wall integrity. This finding suggests that Bem4p also affects Rho1p function. Bem4p displayed two-hybrid interactions with Cdc42p, Rho1p, and two of the three other known yeast Rho-type GTPases, suggesting that Bem4p can interact with multiple Rho-type GTPases. Models for the role of Bem4p include that it serves as a chaperone or modulates the interaction of these GTPases with one or more of their targets or regulators.

Amino Acid Sequence↗
PubMed1996

Inhibition of testicular germ cell apoptosis and differentiation in mice misexpressing Bcl-2 in spermatogonia.

During normal spermatogenesis, more than half of the germ cells undergo apoptosis, but the physiological significance and molecular mechanisms of this programmed cell death are largely unknown. Because Bcl-2 functions as a death repressor, we have investigated the effect of misexpressing Bcl-2 in spermatogonia in transgenic mice using the human bcl-2 cDNA under the control of the human polypeptide chain elongation factor 1alpha (EF-1alpha) promoter. In the 2-week-old transgenic testes, exogenous Bcl-2 was expressed in spermatogonia and massive accumulation of spermatogonia was observed in seminiferous tubules by 4 weeks. At this time, only a few spermatocytes were apparent, and the accumulated cells degenerated, leading to vacuolization in some seminiferous tubules by 7 weeks. In older transgenic mice, abnormal accumulation of spermatogonia and degeneration of these germ cells was still observed, but some seminiferous tubules in which the level of Bcl-2 expression was reduced recovered normal spermatogenesis. These observations indicate that spermatogonial apoptosis is part of the normal program of mammalian spermatogenesis and is regulated by a pathway affected by Bcl-2.

Animals↗
PubMed1996

[Dissection of the interventricular septum with aorto-left ventricular communication due to infective endocarditis--report of a rare case].

Dissection of the interventricular septum is an uncommon manifestation, which is rarely associated with infective endocarditis, aneurysm of sinus of Valsalva and thoracic trauma. We report a 34-year-old male case with aorto-left ventricular communication due to infective endocarditis. The patient had chief complaints of dyspnea on exertion and precordial discomfort. Preoperative laboratory data showed normal white blood cell counts, a slightly elevated CRP, and negative blood culture in bacterial examinations. Echocardiogram revealed progressive dissection of the interventricular septum and stenosis of the left ventricular outflow tract. Disturbance of conduction including progressive atrioventricular block and bundle branch block were found in the electrocardiogram. The dissection extended over 2 x 2 x 2.5 cm in diameter, with an entry located at the basis of the right coronary cusp and reentry communicated to the left ventricle. Operative procedures included the aortic valve replacement with prosthetic valve due to severe inflammation, in addition to resection of the dissecting cavity. Pathological examination of the resected tissue accorded with infective endocarditis in active phase, showing necrosis, small cell infiltration and microabscess. However, a bacterial colony was not found in the surgical specimen. Postoperative course was uneventful and the patient was discharged in satisfactory conditions.

Adult↗
PubMed1996

[Successful aorto-coronary bypass grafting and concomitant left ventricular myotomy-myectomy in a patient with coronary artery disease associated with hypertrophic obstructive cardiomyopathy].

A 65-year-old man complained chest oppression at rest and dizziness. Echocardiography showed subaortic stenosis with outflow gradient of 100 mmHg, although interventricular septal thickness was only 12 mm and left ventricular posterior wall thickness was 11 mm, and mild mitral regurgitation. Selective coronary angiography demonstrated 90% stenosis in left main truncus, 50% stenosis in first diagonal branch, and hypoplastic right coronary artery. Emergent coronary artery revasculization concomitant with left ventricular myotomy myectomy was performed. Immediately after weaning off the cardiopulmonary pump, IABP was employed for cardiac assistance, because of residual left ventricular outflow pressure gradient, which was provoked by cathecholamine and amyl nitrite. He was discharged in 1 month in NYHA class I. Echocardiography 3 months after operation showed no residual outflow pressure gradient, no systolic anterior motion of mitral anterior leaflet, and mild approximately mitral regurgitation. Careful operative management, including myocardial protection and avoiding perforation of ventricular septum and postoperative medical care are mandatory to this group of patients. This case is the first successful coronary artery bypass grafting and concomitant left ventricular myotomy-myectomy reported in Japan.

Aged↗
PubMed1996

[A case of redo operation for ascending aortic aneurysm after modified Bentall operation for Marfan syndrome associated with type A acute dissecting aortic aneurysm].

A 37-year-old man who had undergone modified Bentall operation in December 1986 had redo operation for ascending aortic aneurysm. Initial operation, in other institute, included aortic root replacement using composite graft and reconstruction of coronary arteries. Left coronary ostium was directly anastomosed to composite graft while a saphenous vein was grafted between composite graft and right coronary artery concomitant with closing right coronary ostium. In addition, composite graft was wrapped with native aortic wall and Cabrol trick was carried out. In December 1994, this patient required redo operation for a 90 mm size of ascending aotric aneurysm which had been used for wrapping in the initial operation. The findings at reoperation revealed patent Cabrol trick, occluded saphenous vein graft, dehiscent proximal anastomosis of saphenous vein graft and partial dehiscence of distal anastomosis of composite graft. The repairs included new saphenous vein grafting to right coronary artery and re-anastomosis of distal site of composite graft. Cabrol trick was closed and composite graft was not wrapped. His post-operative course was excellent and post-operative scintigram indicated ameriolation of inferior wall ischemia.

Acute Disease↗
PubMed1996

[Selective thermocoagulation of unresectable malignant tumors using radiofrequency].

Based on our experimental findings on porcine liver, we have been conducting a clinical trial of selective hyperthermia by radiofrequency (RF) capacitive heating with laparotomy for patients with unresectable malignant tumors. In 10 patients with malignant tumors (8 carcinoma of the pancreas, 2 carcinoma of the gallbladder), laparotomy and RF heating were performed after informed consent. The local heat coagulation was produced by heating equipment using 13.56 MHz radiofrequency produced by Omron Corporation, Japan. Four 2-cm electrode needles were placed in the tumor in a square array at intervals of 2.0 cm. Hyperthermia was given for 30 min with a controlled temperature of 50 degrees C in the RF field (2 x 2 x 2 cm3). That of the surrounding area was maintained at less than 40 degrees C. The calculated volume treated by RF ranged between (2 x 2 x 2 cm3) x 1 and (2 x 2 x 2 cm3) x 6. We followed all patients by computed tomographic (CT) scan 2 weeks after coagulation. Tumor markers in the blood were assayed before and 14 days after heating. Follow-up CT scans demonstrated that after the tumor mass had been heterogeneously enhanced, it changed to a homogeneous low-density area in 6 of 10 patients. The levels of tumor markers decreased to lower than the pre-treatment values in 9 of 10 patients. In all patients, the changes in CT scans and/or decrease in the markers were confirmed. Complications such as bleeding or abscess formation were not observed. It was suggested that the selective hyperthermia was safely produced by this equipment. The encouraging results in these patients justify further clinical trials.

Biomarkers, Tumor↗