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Biomedical subjects

Y Miyata

Publications and source records attributed to Y Miyata.

At least 145 records · Page 8Linked to original sources
PubMed1997

[Transurethral electrovaporization of the prostate (TUV-P): comparative study with transurethral resection (TUR-P)].

A total of 27 patients with benign prostatic hyperplasia were treated by transurethral electrovaporization of the prostate (TUV-P). A roller bar electrode was used for 13 patients and a roller loop electrode for 14. Therapeutic efficacy and complications of TUV-P were compared with those of transurethral resection of the prostate (TUR-P) performed before TUV-P was started (24 patients). The improvements in subjective symptom scores and objective voiding parameters after 3 months were not significantly different between the TUV-P and TUR-P groups. Furthermore, the improvements were similar between TUV-P using the roller bar and the roller loop. No patients treated by TUV-P had TUR syndrome or received blood transfusion, while blood transfusion was performed in 4 patients treated by TUR-P. Postoperative duration of urethral catheterization and hospital stay was significantly shorter in the TUV-P group than in the TUR-P group. The operative time for TUV-P (roller bar) was 1.6 min per g. preoperative prostate volume, while that for TUV-P (roller loop) and TUR-P was 2.1 and 1.9 min/g, respectively. From our experience, TUV-P was as effective as TUR-P for relieving bladder outlet obstruction with fewer complications. Furthermore, the operative time could be shortened with a roller loop.

Aged↗
PubMed1997

[Primary pulmonary lymphoma presenting as an endobronchial polypoid tumor].

A 58-year-old woman because of coughing and an abnormality on a chest renggenogram was referred to our hospital. A chest X-ray film and a computed tomogram revealed atelectasis of the right lower lobe and a round tumor in the left lower lobe. Fiberoptic bronchoscopy revealed an endobronchial polypoid tumor in the intermediate bronchus, which completely obstructed the orifice of the right lower-lobe bronchus. Microscopical examination revealed B-cell diffuse, large, non-Hodgkin's lymphoma. No extrapulmonary lesion was found, and therefore primary pulmonary non-Hodgkin's lymphoma was diagnosed. Chemotherapy resulted in rapid and complete regression of the tumor, which was confirmed endoscopically and histologically. The patient was still in complete remission 8 months after the end of chemotherapy. There have been no additional interventions.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Pulmonary metastasis after resection of non-invasive thymoma: a case report--analysis of nuclear DNA pattern and pathological findings].

After resection of a non-invasive thymoma, two metastatic lung tumors were found in the left upper lobe and the left lower lobe. There were differences in tumor doubling time (TDT) and invasion between the metastatic tumor in the lower lobe and the one in the upper lobe. The TDTs of the tumors were 834.1 days and 328.3 days, and the tumor of the left lower lobe invaded the left lateral basal segmental bronchus (B9). The differences in the two tumors were determined by pathological findings and nuclear DNA pattern. Pathologically, the resected thymoma and both of the metastatic tumors were mixed type, which consisted of epithelial cells and lymphocytes. But by epithelium form, the resected thymoma and the tumor in the lower lobe were classified as cortex type, and only the slow growing tumor in the upper lobe contained a spindle-cell component. The DNA pattern of the resected thymoma was aneuploid and the two metastatic tumors were diploid. As this case is very interesting clinically and pathologically, we reported it.

Cell Division↗
PubMed1997

[Interstitial pneumonia associated with human adjuvant disease which developed 30 years after silicone augmentation mammoplasty].

A 51-year-old woman was admitted to our hospital with exertional dyspnea, swelling and stiffness in her fingers. Raynaud's phenomenon and mammary and axillary lymphadenopathy. She had received silicone augmentation mammoplasty 30 years ago, and had since noticed bilateral mammary and axillary lymphadenopathy that was stable in size. In the 2 years before admittance she had become aware of an exacerbation of the lymphadenopathy had begun to experience and exertional dyspnea several months before admission suggesting a connective tissue disease. Physical examination revealed symmetrical weakness of the proximal limb muscles and fine crackles in the base of both lungs. Elevated myogenic enzymes, inflammatory reactions, and positive anti-SSA antibody were noted. Based upon these findings, muscle and lip biopsy results, myogenic EMG, and an apple tree appearance on sialography, a differential diagnosis of polymypositis or sjögren's syndrome was made. Axillary lymph node biopsy findings were consistent with silicone lymphadenitis. In addition, chest roentgenogram and HRCT (which revealed decreased lung volumes and interstitial opacities with no honeycombing, present predominatly in the subpleural space), pulmonary function tests (decreased VC and DLco), bronchoalveolar lavage (elevated total cell count and neutrophil and eosinophil fractions), and transbronchial lung biopsy specimens (unevently distributed alveolitis with fibrosis) indicated concurrent interstitial pneumonia. The clinical correlation between exacerbation of silicone lymphadenopathy and the development of connective tissue disease with accompanying interstitial pneumonia strongly suggested human adjuvant disease (HAD) as the pathogenesis. To our knowledge, interstitial pneumonia associated with HAD is rare.

Breast Implants↗
PubMed1996

Evaluation of the radiosensitizing effects of RK28 intravenous, intraarterial, and intratumoral injections on the rabbit VX2 tumor system.

PURPOSE: To evaluate the differences in the radiosensitizing effects of intravenous (i.v.) injection, intraarterial (i.a.) injection, and intratumoral (i.t.) injections of the hypoxic cell radiosensitizer RK28 ([1-(4'-hydroxy-2'-butenoxy)methyl-2-nitroimidazole], a 2-nitroimidazole with an acyclic sugar analogue substituted at the N-1 position of the imidazole ring) using an animal experimental system. METHODS AND MATERIALS: Rabbit VX2 tumors, which were implanted in the muscle of left hind legs and grown to 3 cm in diameter, were treated with RK28 (80 mg/kg x b.wt.) before 15 Gy of local x-ray irradiation. The auricular vein and the left saphenous artery were used for systemic injection and regional injection, respectively. For i.t. injection, a 21-gauge needle with three lateral holes was positioned in the central area of the tumor. Tumor regression was precisely evaluated by computed tomograpy (CT), and survival time was also studied. Using high-performance liquid chromatography (HPLC), pharmacokinetic studies for RK28 and its seven major metabolites were performed in tumor and serum at 0, 10, 20, 30, and 60 min after drug injection was completed. RESULTS: Radiosensitizing effects of RK28 were considered present after i.a. injection (p < 0.05) and i.t. injection (p < 0.05) after analyzing tumor volumes on day 21 after treatment. Increased survival was not observed in any group with RK28 injection compared with survival in the group treated by x-ray irradiation alone. Pharmacokinetic studies showed the average concentration of RK28 in the tumor during x-ray irradiation was 1.3 times higher after i.a. injection and 3.5 times higher after i.t. injection than that after i.v. injection. The time modifying factor50 (TMF50: ratio of time for tumor to decrease by 50%, radiation alone vs. radiation plus drug) was calculated to be 1.5 after i.v. injection, 1.7 after i.a. injection, and 2.3 after i.t. injection. The values of TMF50 correlated to the average concentrations of RK28 in the tumor. As to metabolites of RK28, beta-glucuronated compound and cysteine conjugate were highly detected. The concentrations of cysteine conjugate were higher in the tumor than in serum via i.v. injection. CONCLUSIONS: Radiosensitizing effects of RK28 were observed on the rabbit VX-2 tumor system after i.a. or i.t. injection. Pharmacokinetic studies proved that radiosensitizing effects depended on the concentration in the tumor, though the administration routes were different. Combined forms with nonprotein thiols were detected. However, survival benefits were not obtained by RK28. For clinical applications of RK28, i.a. or i.t. injection could facilitate better local control of cancer.

Animals↗
PubMed1996

Increased sensitivity of EBNA2-transformed rat fibroblasts to ionizing radiation.

To clarify whether expression of Epstein-Barr virus(EBV) nuclear antigen 2 (EBNA2) correlates with sensitivity to ionizing radiation, we tested EBNA2-transformed rat fibroblast clones for their radiosensitivity to X-rays. These transformed clones reproducibly generated tumors in mice. X-irradiation suppressed the growth of the tumors, and irradiated mice survived longer than non-irradiated ones. In contrast, tumors formed by activated H-ras or E6-E7 genes of human papillomavirus type 16 (HPV16) were strongly resistant to the same dose of X-irradiation. In in vitro culture, these EBNA2-expressing clones also showed higher radiosensitivity than cell lines transformed by activated H-ras and E6E7 genes. The averaged D(o) of EBNA2-expressing clones was 2.3 times lower than that of non-expressing and control clones. These results suggest that expression of EBNA2 is responsible for the radiosensitivity.

Animals↗
PubMed1996

Induction of apoptosis in a Drosophila neuronal cell line by calcium ionophore.

Apoptotic type cell death was induced by the calcium ionophore, A23187, in a Drosophila CNS derived cell line, ML-DmBG2-c2. It was judged by the ultrastructural observations and internucleosomal DNA fragmentation, typical characteristics of apoptosis. The ionophore failed to induce apoptosis in Ca2+- free medium, which suggests that the increase of intracellular Ca2+ concentration by the treatment of A23187 triggers apoptosis in the clonal cells.

Animals↗
PubMed1996

Changes in En(a-) human red blood cell membranes during in vivo ageing.

The human red blood cells with phenotype En(a-) were characterized by the lack of MN antigens. The red blood cells with phenotype En(a-) which were found in a Japanese family were tested to clarify the changes in membrane surfaces of the red blood cells during in vivo ageing. The contents of sialic acid, glucose, mannose, galactose, fucose, N-acetylglucosamine and N-acetylgalactosamine of the red blood cell membranes obtained from the old red blood cells with phenotype En(a-) were significantly lower than those of the young red blood cell membranes. Neither the young nor the old red blood cells with phenotype En(a-) showed the agglutination with Arachis hypogaea (PNA) which was capable of binding to T agglutinogen. It is presumed that En(a-) red blood cells are not exposed to sialidase in vivo. In comparison with the young En(a-) red blood cell membranes, the number and the distribution density of lectin receptor sites on the old ones for Limulus polyphemus (LPA), Canavalia ensiformis (Con A), Triticum vulgaris (WGA) and Bauhinia purpurea (BPA) were significantly lower. It is thought that En(a-) red blood cell ageing is accompanied by elimination of some sialoglycoconjugates which have affinity for LPA, Con A, WGA and BPA, whereas En(a-) red blood cells lack glycophorin A.

Adult↗
PubMed1996

Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins in rabbit gastric antral mucosa.

Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins (PGs) in rabbit gastric antral mucosa were examined. Fe(2+) inhibited the cyclooxygenase activity in the microsomal fraction. Zn(2+) suppressed the endoperoxide E(2) isomerase activity in the microsomal fraction and the 15-hydroxy PG dehydrogenase (PGDH) activity in the cytosolic fraction. Cu(2+) stimulated the cyclooxygenase activity, inhibited the PGDH activity and possibly induced non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha) Se(4+) possibly induced the non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha), as well as Cu(2+). These results suggest that Fe(2+), Zn(2+), Cu(2+) and Se(4+) can be modulators of the gastric antral mucosal PG levels by affecting the PG synthesizing enzymes, PG catabolizing enzyme and/or non-enzymatic reduction of PGG or PGH to PGF.

Animals↗
PubMed1996

Interleukin-1 beta and tumor necrosis factor-alpha stimulate synergistically the expression of monocyte chemoattractant protein-1 in fibroblastic cells derived from human periodontal ligament.

The present study demonstrates that interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) induce and synergistically stimulate monocyte chemoattractant protein-1 (MCP-1) expression in fibroblasts from human periodontal ligament. IL-1 beta and TNF-alpha induced in a dose-dependent manner the expression of the MCP-1 gene in the fibroblasts from the human periodontal ligament. However, such an inducing effect was not observed with IL-6 and interferon-gamma. The peak expression of the MCP-1 gene by IL-1 beta or TNF-alpha was observed at 3 h after initiation of their treatment. Furthermore, IL-1 beta in combination with TNF-alpha synergistically stimulated the MCP-1 gene expression in the cells. We also observed significant chemotactic activity for human monocytes in conditioned medium of fibroblasts from the human periodontal ligament treated with both cytokines. The stimulated chemotactic activity induced by these cytokines depended on both dose and treatment time. The chemotactic activity in conditioned medium of IL-1 beta-treated fibroblasts from the human periodontal ligament was neutralized by antiserum specific for MCP-1 protein. The MCP-1 gene product in conditioned medium of IL-1 beta-treated fibroblasts from the human periodontal ligament was shown to have a molecular mass of 11,000 Da by immunoprecipitation with the specific antiserum, and IL-1 beta also stimulated synergistically MCP-1 protein expression in combination with TNF-alpha. These results suggest that IL-1 beta and TNF-alpha may contribute to the infiltration of monocytes into inflammatory sites of periodontal ligament tissues via the MCP-1 gene product produced by fibroblasts from the human periodontal ligament.

Chemokine CCL2↗
PubMed1996

[Bacteriological studies of travellar's diarrhoea. 5) Analysis of enteropathogenic bacteria at Osaka Airport Quarantine Station from January 1992 through September 3rd, 1994].

During the last 2 years and 8 months before the closure of Osaka Airport Quarantine Station (from Jan. 1992 to Sep. 3, 1994), a total of 7,421,909 overseas travellers were quarantined. 15,919 reported themselves of suffering from diarrhoea. Bacteriological examination of a total of 6,031 individuals' stools were performed. 1) Various enteropathogenic bacteria were isolated from 31.2% of the stools examined. Isolated species were as follows: Plesiomonas shigelloides, 1,127 cases (59.9%); Vibrio parahaemolyticus, 293 cases (15.6%); Salmonella spp., 262 cases (13.9%); Shigella spp., 235 cases (12.5%); Aeromonas sobria, 93 cases (4.9%); V. cholerae non-O1, 69 cases (3.7%). 2) The enteropathogenic bacteria were isolated through out the year without any seasonal variation. 3) The major regions where the travellers were infected with the pathogens are as follows: V. cholerae non-O1 (NAG Vibrio) and enteropathogenic Escherichia coli, South-East and South-West Asia; Vibrio other than NAG, South-East and East Asia; Shigella, widely distributed but especially in India; P. shigelloides and Salmonella, widely distributed. 4) 2 strains of toxigenic (cholera toxin-producing) V. cholerae O139 were isolated from patients who had visited Indonesia and Thailand, respectively. 5) In 320 cases (17%), plural enteropathogenic bacteria were isolated from single patients, suggesting a high frequency of the mixed infections. 6) Among Shigella strains, S. sonnei were isolated the most, followed by S. flexneri (24.7%), S. boydii (8.8%) and S. dysenteriae (2.9%). 7) Among Salmonella serovers, Salmonella Enteritidis was isolated the most frequently (39 cases, 14.1%). 8) 218 (91.6%) of 238 Shigella strains and 103 (37.6%) of 276 Salmonella strains were resistant to one or more drugs tested (SM.CP.TC.KM.ABPC.NA.OFLX). 9) All of the 22 V. cholerae O1 strains were Ogawa, E1 Tor. Among them, 19 were toxigenic strains and 3 were non-toxigenic. 10) O4:K8 was the most frequently isolated serover of V. paraemolyticus. 87.4% of all V. parahaemolyticus strains were positive with thermostable direct hemolysin (TDH) gene, and 12.6% of them were positive with TDH-related hemolysin (TRH) gene by DNA-probe methods.

Diarrhea↗
PubMed1996

Myocardial bridge muscle on left anterior descending coronary artery differs from subepicardial myocardium of the left ventricle in dogs.

The myocardial bridge (MB) is a muscle band found sporadically above the coronary artery (CA) in humans and certain animals such as the dog, cat and sheep. The purpose of our study was to compare the structure of the MB muscle with that of tissue from the subepicardial myocardium. The histological studies included toluidine blue staining of 1-micron-thick sections and Gomori's trichrome staining of canine cardiac samples. The MB muscle of the dog heart is characterized by a distinctive spatial arrangement, with individual fibers separated by substantial elements of intercellular connective tissue in cross-section. Longitudinally, the long, slender fibers are aligned continuously with intermediation of intercalated disks lying perpendicular to the long axis of the fibers. In other regions of the left ventricular subepicardial myocardium, each myocyte is tightly packed in transverse view. There is great variation in the thickness (0.11-2.24 mm, average 0.45 mm) of MBs and the distance (24-236 microns, average 103 microns) between MBs and the left anterior descending coronary artery (LAD) among the 13 affected dogs examined, with no apparent relationship between the occurrence of MBs and either age or sex. These results on MB alignment suggest that the MB muscle generates force along the long axis of the fiber orientation as skeletal muscle does, and with minimal constriction of the CA; if so, the function of MB myocytes may differ from that of common cardiac myocytes, as does the structure. Then, the long-supposed downward compressive force of MBs on the LAD would be minimal in most cases; however, when the MB produces a systolic narrowing of the LAD known as the milking effect, the degree of lateral compression and its influence should depend not only on the substantial size of the MB muscle but also on the distance between the MB muscle and LAD. The environment surrounding the LAD may be a crucial factor in determining whether the MB influences the induction of heart disorders or not.

Animals↗
PubMed1996

Effects of chicken extract on the recovery from fatigue caused by mental workload.

Folk wisdom suggests that chicken extract is useful for recovery from physical and mental fatigue. To explore this question, the physiological effect of Brand's Essence of Chicken (BEC), a popular chicken extract used as a traditional remedy, was assessed during recovering from mental stress. We quantitated the blood levels of stress-related substances, and examined the task performance and subjects' mood states during mental workloads. Subjects were 20, healthy male students who have never tasted BEC. They took two bottles of BEC or a placebo (70 ml/bottle) daily in the morning for 7 days. On the final experimental day, two mental workload tests were performed: (A) a mental arithmetic test (MAT; 1600 trials of two or three figure-addition or subtraction for 40 min). (B) a short-term memory test (SMT; 20 trials of memorizing 9 digit numbers). Blood was collected before and after each workload task. After the mental workload, the recovery of mean cortisol level of subjects who consumed BEC was significantly faster than that for those consuming the placebo. The task performance of subjects performing the MAT and SMT was also improved with BEC consumption compared with placebo. According to the profile of mood state questionnaire, subjects felt more active and less fatigued during the workload when they took BEC regularly. We conclude that the extract of chicken has the potential to metabolize stress-related substance in blood and to promote recovery from mental fatigue.

Adolescent↗
PubMed1996

Eyeblinks in formation of impressions.

The purpose of this study was to investigate the influence of frequency of one's eyeblinks on creating a personal impression. The subjects, 102 males and 127 females, ages 15 to 60 years, rated on a 7-point semantic differential scale a rarely blinking person or a frequently blinking person described on a question-sheet. A factor analysis of the ratings yielded three factors, interpreted as Nervousness, Unfriendliness, and Lack of intelligence. The frequently blinking person was rated as more nervous and less intelligent than the rarely blinking person. Present results provided evidence that frequency of eyeblinks may play an important role on the formation of impressions. Further implications of the findings are discussed.

Adolescent↗
PubMed1996

[Single-stage surgery for annulo aortic ectasia, Stanford type-A aortic dissection and pectus excavatum in a patient with Marfan's syndrome].

A 43-year-old female was hospitalized on October 25, 1993, due to severe back pain. She was diagnosed with annulo aortic ectasis, Stanford type-A acute aortic dissection and pectus excavatum caused by Marfan's syndrome. On November 30, 1993, single-stage surgery was performed, including modified Bentall procedure, aortic arch replacement, elephant trunk method and sternoplasty. Concerning the procedure for pectus excavatum, sternoplasty was selected because we thought that sternoplasty could endure the long procedure which would cause infection compared with sternal turnover. Postoperative course was satisfactory, and she is well 18 months after surgery.

Adult↗