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Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

At least 91 records · Page 5Linked to original sources
PubMed2000

Pathology of the arteries in the central nervous system with special reference to their dilatation: blood flow.

Arteries that belong to the central nervous system (CNS) have thick and monotonous internal elastic lamina (IEL), Willis ring, and no collateral branch to the systemic circulation. These characteristics suggest that the circulation of the CNS is constant. In order to know how flow controls the arterial configuration of the CNS, flow of the vertebral and basilar arteries was increased experimentally using eight adult male Japanese white rabbits. Flow increase was induced by the simple ligation of the bilateral common carotid arteries (ligation group, n = 4) or by the ligation of the bilateral common carotid arteries at 1 week after arteriovenous fistula (AVF) between the left common carotid artery and the left external jugular vein (ligation plus AVF group, n = 4). Cineangiography revealed distinct flow increase in the ligation group at 5 weeks after ligation and in the ligation plus AVF group at 5 weeks after AVF (4 weeks after ligation). Vertebral and basilar arteries were remarkably dilated and elongated. Histopathologically, severe disruption of the IEL and focal thinning of the media were distinct. Endothelial cells were preserved and there was no inflammatory cell infiltration. These morphological features are consistent with increased flow-induced adaptive remodeling. It is suggested that the constancy of the flow may give the arterial tree of the CNS these morphological characterizations.

Animals↗
PubMed2000

Three-dimensional hysterosalpingo-contrast sonography (3D-HyCoSy) as an outpatient procedure to assess infertile women: a pilot study.

OBJECTIVES: This study aimed to assess the use of three-dimensional hysterosalpingo-contrast sonography (3D-HyCoSy) as a routine outpatient procedure for evaluating infertile women. METHODS: In 25 unselected infertile patients, tubal patency and uterine cavity were investigated by 3D-HyCoSy with saline as a contrast medium. The efficacy of the procedure was evaluated with X-ray hysterosalpingography (XHSG) as reference. RESULTS: The positive predictive value, negative predictive value, sensitivity, and specificity of predicting tubal patency by 3D-HyCoSy were 100, 33.3, 84.4, and 100%, respectively. The full contour of the uterine cavity was depicted in 96% of cases by 3D-HyCoSy and 64% by XHSG (P < 0.005). The uterine cavity area measured on 3D-HyCoSy correlated well with the volume of contrast medium required on XHSG (r2 = 0.8166). CONCLUSIONS: 3D-HyCoSy provided advantages of better assessment of uterine cavity over XHSG. Compared with conventional XHSG, the efficacy of 3D-HyCoSy to assess tubal patency was acceptable. In addition, the procedure of 3D-HyCoSy appears to be better tolerated, requiring no sedation or anesthesia and a reduced examination time. Thus, 3D-HyCoSy with saline as a contrast medium is feasible and could comprise a routine outpatient procedure in the initial evaluation of infertile women.

Adult↗
PubMed2000

The progression of invasiveness regarding the role of transforming growth factor beta receptor type II in gastric cancer.

AIMS: Transforming growth factor beta (TGF beta) is a potent growth inhibitor of epithelial cells. The expression of TGF beta receptors is required for the effect of TGF beta. In this study, we used immunohistochemistry to demonstrate the roles of the expression of TGF beta type I (T beta R-I) and type II (T beta R-II) receptors in the progression of gastric carcinoma. METHODS: To evaluate the potential prognostic value of T beta R-I and T beta R-II, 158 consecutive gastric cancer tissues specimens obtained over a 3-year period were examined. RESULTS: A total of 50 (32%) and 28 (18%) patients had T beta R-I(+) and T beta R-II(+), respectively. The 5-year survival rates of the patients with T beta R-I(+) and those with T beta R-I(-) were 74% and 71%, respectively. In contrast, the 5-year survival rates of the patients with T beta R-II(+) and those with T beta R-II(-) were 57% and 75%, respectively, and the difference was statistically significant (P<0.05). The extent of T beta R-II was closely correlated to the macroscopic types based on the Borrmann classification (P<0.01), and curability (P<0.05). However, a significant difference between the 5-year survival rates of the patients with T beta R-II(+) and those with T beta R-II(-) was only obtained in advanced cases (P<0.05) not in either curative cases, non-curative cases, or early cases. CONCLUSIONS: Our data suggest that when T beta R-II expression correlates with the progression of invasiveness in gastric cancer, it may lead to a non-curative resection and a poor prognosis.

Adult↗
PubMed2000

The influence of human T lymphotropic virus type I infection on the outcome of cardiovascular surgery.

OBJECTIVE: Human T lymphotropic virus type I infects CD4(+) T cells and affects cell-mediated immunity. Cardiopulmonary bypass transiently alters lymphocyte subsets, resulting in a reduction in CD4(+) T cells and an increase in CD8(+) T cells. We proposed that cardiovascular operations and human T lymphotropic virus type I infection may act synergistically, resulting in serious damage to cell-mediated immunity. METHODS: A total of 517 consecutive patients who were preoperatively screened for anti-human T lymphotropic virus type I antibody and underwent cardiovascular operations with cardiopulmonary bypass were enrolled in this study. Of the 517 patients, 82 (16%) had positive test results for anti-human T lymphotropic virus type I antibody. The surgical outcome of patients with positive and negative results for anti-human T lymphotropic virus type I antibody was analyzed retrospectively. RESULTS: There was no difference between the 2 groups with respect to early mortality. Distribution of survival curve was also not significantly different (P =.5; mean follow-up duration, 2.4 +/- 1.8 years [range, 0-9.4 years] and 3.2 +/- 2.8 years [range, 0-9.8 years]) in the groups with positive and negative antibody results, respectively). In particular, long-term follow-up did not reveal adult T-cell leukemia or human T lymphotropic virus type I-associated myelopathy, and occurrence of neoplasm did not differ between groups. Early infectious complication was, however, significantly higher in the group with positive antibody results than in the group with negative results (P =.02). Logistic regression analysis revealed human T lymphotropic virus type I infection as a significant risk for this complication (P =.04; odds ratio, 2.5; 95% confidence interval, 1. 0-5.8). CONCLUSION: A combination of human T lymphotropic virus type I infection and cardiovascular operation is believed to increase the potential risk of infectious complications shortly after the operation. However, this synergistic effect seems to be transient and has little influence on long-term prognosis.

Aged↗
PubMed2000

Preoperative autologous donation of blood for a simple cardiac anomaly: analysis of children weighing under twenty kilograms.

OBJECTIVE: Preoperative autologous donation of blood has been expanded to cardiac operations in children. However, because of problems such as lack of cooperation and hemodilution during cardiopulmonary bypass, its efficacy in small children is unclear. This study clarifies the clinical significance of preoperative autologous donation of blood in small children. METHODS: Thirty-seven patients weighing under 20 kg (age range, 3-9 years; weight range, 13-20 kg) underwent preoperative autologous donation and cardiac operations to treat a simple anomaly. Twenty-five age- and weight-matched patients who were not cooperative or refused preoperative autologous donation served as control subjects. Autologous blood was collected by the simple or leapfrog method and stored as blood components. Each collecting volume was 5 to 10 mL/kg. RESULTS: The donation was performed 6+/-2 times during 50+/-16 days, and the whole storage volume was 48+/-17 mL/kg. There was no serious complication. The minimum hematocrit level negatively correlated with the priming volume of cardiopulmonary bypass (preoperative donation patients: P<.01, r(2) = 0.4; control subjects: P =.5, r (2) = 0.03). Blood loss did not significantly differ between preoperative donation patients and control subjects, and the transfused blood volumes were 43+/-13 mL/kg and 29+/-22 mL/kg, respectively. All of the autologous blood products but fresh frozen plasma were reinfused. Use of homologous blood was significantly less in preoperative donation patients than in control subjects (0% vs 80%, P <.01). In preoperative donation patients postoperative recovery in hemoglobin level was significantly better, which is concurrent with a higher reticulocyte level. CONCLUSION: Preoperative autologous donation can be performed safely with clinical efficacy, even in children under 20 kg. This can be improved further through coupling with another procedure.

Analysis of Variance↗
PubMed2000

Somnolence syndrome in a child following 1200-cGy total body irradiation in an unrelated bone marrow transplantation.

Neurological complications may occur following intensive chemotherapy and hematopoietic cell transplantation. Postirradiation somnolence syndrome has been observed in children with acute lymphoblastic leukemia who received central nervous system preventive therapy with 1800-2400 cGy cranial irradiation. The authors report a 16-year-old boy with chronic myelogenous leukemia in chronic phase, who developed symptoms compatible with the somnolence syndrome (SS) 6 weeks following HLA-matched unrelated bone marrow transplantation (BMT). The preparative regimen consisted of 1200 cGy total body irradiation (TBI), cytosine arabinoside and cyclophosphamide. The patient developed lethargy and low-grade fever, with intermittent rhythmical delta activity in electroencephalograph. He recovered spontaneously without specific therapy 3 weeks after developing symptoms. This is the first report describing that as low as 1200 cGy TBI can induce SS in a child. After allogeneic BMT, some patients develop neurological symptoms. The authors suggest that somnolence syndrome should be included in differential diagnosis in these patients.

Adolescent↗
PubMed2000

Identification of ribonucleotide reductase protein R1 as an activator of microtubule nucleation in Xenopus egg mitotic extracts.

Microtubule nucleation on the centrosome and the fungal equivalent, the spindle pole body (SPB), is activated at the onset of mitosis. We previously reported that mitotic extracts prepared from Xenopus unfertilized eggs convert the interphase SPB of fission yeast into a competent state for microtubule nucleation. In this study, we have purified an 85-kDa SPB activator from the extracts and identified it as the ribonucleotide reductase large subunit R1. We further confirmed that recombinant mouse R1 protein was also effective for SPB activation. On the other hand, another essential subunit of ribonucleotide reductase, R2 protein, was not required for SPB activation. SPB activation by R1 protein was suppressed in the presence of anti-R1 antibodies or a partial oligopeptide of R1; the oligopeptide also inhibited aster formation on Xenopus sperm centrosomes. In accordance, R1 was detected in animal centrosomes by immunofluorescence and immunoblotting with anti-R1 antibodies. In addition, recombinant mouse R1 protein bound to gamma- and alpha/beta-tubulin in vitro. These results suggest that R1 is a bifunctional protein that acts on both ribonucleotide reduction and centrosome/SPB activation.

Amino Acid Sequence↗
PubMed2000

Preoperative concurrent chemoradiotherapy against muscle-invasive bladder cancer: results of partial cystectomy in elderly or high-risk patients.

BACKGROUND: Good local control has been reported in cases of muscle-invasive bladder cancer treated by chemoradiotherapy and transurethral resection (TUR). However, definitive irradiation or extensive chemotherapy is often intolerable for elderly or poor-risk patients. We report here benefits of partial cystectomy after concurrent low-dose chemoradiotherapy for high-risk patients. METHODS: Thirty-seven patients with localized muscle-invasive bladder cancer (T2-T4) were treated with concurrent cisplatin (50-100 mg/body x 2 courses) and pelvic irradiation (40 Gy) preoperatively. Among 17 patients (46%) who achieved complete response (CR), 10 were not suitable for radical cystectomy and underwent partial cystectomy. Radical cystectomy was performed in 24 cases [CR = 6, partial response (PR) = 18]. Two patients (one CR and one PR) rejected open surgery and were treated by TUR of the primary site. One no change (NC) patient received no further treatment because of mental disorder. RESULTS: Median follow-up was 12 months (range 2-37 months). Fifteen of 36 evaluable cases (42%) achieved a pathological T0 response (no residual tumor). Estimated 3-year disease-free survival was 56% for all patients and 100% for T0 responders. Seven of 21 patients with pathological persistent tumor developed local recurrence (three patients) or distant metastasis (four patients). All of the 10 patients (eight with T0 response and two with a small residual tumor nest) who underwent partial cystectomy were recurrence-free for an observation period of up to 3 years. CONCLUSIONS: Bladder preservation by partial cystectomy may be a choice for patients who show a good response to preoperative chemoradiotherapy and are not suitable for radical cystectomy.

Aged↗
PubMed2000

Structure of mouse preproendothelin-3 and phylogenetic analysis of the endothelins.

Endothelin (ET)-related peptide hormones, ET-1, vasoactive intestinal contractor (VIC), ET-2 and ET-3, have multiple physiological roles including vasoconstriction. To reveal the structural diversity of the precursor proteins of the ET family, cDNAs, cross-hybridizing with ET-1 and VIC probes, were cloned from the mouse intestine library. The deduced protein is a 214-amino acid precursor of mouse ET-3, preproendothelin-3 (PPET-3), which is the counterpart of the hypothalamus-, not placenta-, derived human PPET-3. Sequence identities of PPET-3 amino acids of mouse with human and rat are 65% over 194 amino acids and 65% over 214 amino acids. Phylogenetic analysis of the precursor proteins for ET-1, VIC and ET-3 suggest that members of the ET family are distantly related and probably descended from a common ancestral gene.

Amino Acid Sequence↗
PubMed2000

The endothelin-2/vasoactive intestinal contractor gene: expression and promoter activity in PC12 rat pheochromocytoma cells.

In order to understand the physiological roles of vasoactive intestinal contractor (VIC)/endothelin-2 (ET-2), we examined the expression of this peptide by specific reverse transcriptase polymerase chain reaction (RT-PCR) analysis and found that PC12 rat pheochromocytoma cells express the VIC gene. The 5'-flanking 1.0 kilo base pair (kb) region of the mouse VIC gene is sufficient to express a secreted alkaline phosphatase (SEAP) reporter gene in transiently transfected PC12 cells. The 1.0 kb promoter region may contain cis-acting elements that determine the rate of the VIC gene transcription in PC12 cells.

Animals↗
PubMed2000

Incidence of amantadine-resistant influenza A viruses in sentinel surveillance sites and nursing homes in Niigata, Japan.

We surveyed the incidence of amantadine-resistant influenza A viruses both at sentinel surveillance sites and at nursing homes, and verified their types of change by partial nucleotide sequence analysis of the M2 protein. Fifty-five influenza A viruses from 27 sentinel surveillance sites during six influenza seasons from 1993 to 1999, and 26 influenza A viruses from 5 nursing homes from 1996 to 1999 were examined for susceptibility to the drug by virus titration in the presence or absence of amantadine. While amantadine-resistant viruses were not found in sentinel surveillance sites, a high frequency of resistance (8/26, 30.8%) in nursing homes was observed. Resistant viruses can occur quickly and be transmitted when used in an outbreak situation at nursing homes, where amantadine is used either for neurologic indications or for influenza treatment. Eight resistant viruses had a single amino acid change of the M2 protein at residue 30 or 31. In vitro, all 11 sensitive viruses turned resistant after 3 or 5 passages in the presence of 2 microg/ml amantadine, and they showed an amino acid change at residue 27, 30, or 31. The predominant amino acid substitution in the M2 protein of resistant viruses is Ser-31-Asp (a change at 31, serine to asparagine). The results indicate that a monitoring system for amantadine-resistant influenza viruses should be established without delay in Japan.

Amantadine↗
PubMed2000

[Incidence of amantadine-resistant influenza A (genotype Ser-31-Asn) in nursing homes in Niigata, Japan].

The antiviral agent amantadine specifically inhibit influenza A virus infection, but the emergence of drug-resistant viruses occur more readily with amantadine treatment. In human influenza viruses, single amino acid changes at 4 sites spanning the transmembrane domain of the M2 protein can confer drug resistance. Amantadine was approved for treatment of Parkinson's disease in 1975, and for the influenza A virus infection in November 1998, in Japan. Annual consumption of amantadine for influenza treatment increased suddenly after the approval. According to our previous report, the predominant genotype of resistant virus is the substitution S-31-N in M2 both in vitro and in clinical samples, as in the other reports. Based on the above findings, we focused on single amino acid change at position 31 (genotype S-31-N) and applied polymerase chain-reaction restriction fragment length polymorphism (PCR-RFLP), directly from throat swab samples, by using primers that insert a restriction site for Sca I. With this technique, we surveyed the incidence of amantadine resistant viruses in nursing homes, Niigata, Japan. Thirty-one (22.0%) of 141 PCR positive samples from 8 nursing homes in 1998-99 season showed resistant patterns, and only 6 (19.4%) of them were after the administration of amantadine for treatment. All of these 8 nursing homes used amantadine for Parkinson's disease, but only half of them used the drug for influenza A infection. The incidence of resistant viruses was not significantly different from facilities with amantadine for influenza treatment to those without, 25.5% and 14.0% respectively. The occurrence of outbreaks and sporadic illness in those facilities, with different administration status were observed, but fortunately we could not find any evidence to relate the emergence of resistant viruses to the outbreaks. This is the first report that the resistant influenza viruses already exist in nursing facilities where amantadine was used for not only influenza but also Parkinson's disease in Japan.

Amantadine↗
PubMed2000

Fluctuating gene expression and localized cellular distribution of vasoactive intestinal contractor (VIC) in mouse uterus.

To understand the physiological roles of vasoactive intestinal contractor (VIC) and endothelin-2 (ET-2) in the uterus, we examined the expression levels of VIC mRNA by real-time quantitative reverse transcription-linked polymerase chain reaction (RT-PCR) and characterized the cellular distribution of VIC peptide and mRNA by immunostaining and in situ hybridization in mouse uterus. In pregnant mouse uterus, VIC mRNA expression changed considerably between Days 10.5 and 12.5 of pregnancy. The expression levels were significantly (p<0.05) higher (approximately fivefold) in the later stage of pregnancy (Days 12.5-17.5) than in the earlier stage (Days 7.5-10.5). In nonpregnant uterus, VIC mRNA expression was significantly (p <0.05) higher (approximately threefold) in proestrus and estrus than in diestrus. Immunohistochemical studies demonstrated the presence of VIC peptide in endometrial epithelial cells, myometrial cells, and vascular smooth muscle cells during the estrous cycle and pregnancy and after parturition. Notably, myometrial cells showed dominant immunostaining in proestrus and estrus, in the later pregnancy stage, and in the early postpartum period, analogous to the expression pattern of VIC mRNA. In situ hybridization confirmed localization of VIC mRNA in myometrial cells. These findings suggest that VIC may play an important role in the function of myometrial cells.

Animals↗
PubMed2000

[Japanese Kana word recognition].

Three experiments were conducted to investigate letter migration in Japanese Kana word recognition. The participants were presented two brief masked "source" words (e.g., [symbol: see text]) each made up of two components (letters), followed by a "probe" word (e.g., [symbol: see text]). The probe word in the critical trials was a blend of two letters, one each from the two source words. The task was to decide whether the probe was one of the source words. The results indicated that the proportion of false positive responses depends on consistency of positions of the components in probe word with those in source words set (global consistency), and on consistency between the first letter of source and probe words (left local consistency). The results also showed that statistical properties of letters, i.e., the number of companions (adjoining letters) of a letter influenced the false response. These results were compared with those with a Kanji word suggesting that knowledge of conjunctive properties of word-components affects word recognition irrespective of scripts.

Adult↗
PubMed2000

[A case of xanthogranulomatous pyelonephritis presenting with the flank subcutaneous mass].

A 51-year-old female exhibited fever, left flank pain and left flank mass in March, 1993. Drip infusion pyelography (DIP) revealed a non-functioning left kidney with shadows of calculi, and abdominal computerized tomography (CT) showed renal calculi and multilocular cystic lesions in the left kidney extending through the perinephric space into the mass on the left flank. Percutaneous nephrostomy and percutaneous drainage were performed, followed by left nephrectomy. Histopathological findings revealed xanthogranulomatous pyelonephritis. There have been a few case reports of xanthogranulomatous pyelonephritis forming nephrocutaneous fistula in the back.

Cutaneous Fistula↗
PubMed2000

[Perioperative risk factors in valve surgery concomitant with coronary artery bypass grafting].

Between January 1990 and December 1999, 20 patients underwent the valve surgery concomitant with coronary artery bypass grafting. There were 16 males and 4 females, their mean age was 66.5 years. Of the 20 patients, aortic stenosis was noted in 7, aortic regurgitation in 3, mitral stenosis in one, and mitral regurgitation in 9 patients. The cause of mitral regurgitation was considered to be an ischemic change in six patients, including ruptured papillary muscle due to myocardial infarction in two patients. On the contrary, LMT lesion was recognized in 5, LAD lesion in 17, LCX in 16, and RCA in 12 patients. Seven patients had preoperative myocardial infarction, three patients were required preoperative IABP support. AVR was performed in 10, MVR in 5, and MAP in 5 patients. The number of bypass was 1.9 +/- 0.85. Four patients died of LOS and MOF. The remaining 16 patients have been doing well. The significant difference between the survived and the not survived patients was recognized in the factor of emergency, preoperative IABP, papillary muscle rupture due to myocardial infarction, history of PTCA, LAD lesion, and the time of CPB. The factors regarding coronary artery had the influence on the outcome of a patients of valve surgery concomitant with CABG. Therefore, an appropriate myocardial protection and perioperative management for ischemia were mandatory.

Adult↗