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Biomedical subjects

Y Miyazawa

Publications and source records attributed to Y Miyazawa.

At least 19 recordsLinked to original sources
PubMed2005

Checkpoint and physiological apoptosis in germ cells proceeds normally in spaceflown Caenorhabditis elegans.

It is important for human life in space to study the effects of environmental factors during spaceflight on a number of physiological phenomena. Apoptosis plays important roles in development and tissue homeostasis in metazoans. In this study, we have analyzed apoptotic activity in germ cells of the nematode C. elegans, following spaceflight. Comparison of the number of cell corpses in wild type or ced-1 mutants, grown under either ground or spaceflight conditions, showed that both pachytene-checkpoint apoptosis and physiological apoptosis in germ cells occurred normally under spaceflight conditions. In addition, the expression levels of the checkpoint and apoptosis related genes are comparable between spaceflight and ground conditions. This is the first report documenting the occurrence of checkpoint apoptosis in the space environment and suggests that metazoans, including humans, would be able to eliminate cells that have failed to repair DNA lesions introduced by cosmic radiation during spaceflight.

Animals↗
PubMed2004

Development of less invasive surgical procedures for thoracic esophageal cancer.

In order to minimize the invasiveness of the operative procedure for thoracic esophageal cancer, several procedures have been introduced since January 1997. They included: (i) perioperative use of steroids; (ii) muscle-sparing thoracotomy without costectomy; (iii) preparation of the gastric tube with preservation of sufficient blood supply; (iv) reconstruction of the alimentary tract via posterior-mediastinal route; and (v) formation of anastomosis between the remaining esophagus and the gastric tube at a location between the gastroepiploic arteries of the gastric greater curvature. Twenty-one patients who did not receive preoperative chemoradiotherapy underwent the newly developed procedure, and were compared with those receiving the original procedure. Hospital mortality was zero, and postoperative systemic inflammatory response syndrome was suppressed. The mean postoperative hospital stay was 21.5 days, and the actuarial 3-year survival rate was 76.2%. From the comparison with those receiving the original procedure, it can be concluded that the newly developed procedures were effective in minimizing surgical invasiveness and were sufficiently curative in terms of cancer treatment.

Anastomosis, Surgical↗
PubMed2003

Prognostic value of preoperative serum immunosuppressive acidic protein in patients with esophageal squamous cell carcinoma.

Immunosuppressive acidic protein (IAP) is a potent biological marker of immunological surveillance in patients with malignant tumors. The aim of this study was to analyze the clinicopathologic significance of IAP in patients with esophageal carcinoma. Preoperative serum IAP concentration was measured by enzyme-linked immunosorbent assay in 115 patients with primary esophageal squamous cell carcinomas. The associations between clinicopathologic factors, C-reactive protein (CRP) values and IAP concentration were determined. Prognostic values were determined by multivariate analysis using Cox's proportional hazards model. The IAP concentration is significantly higher in patients with stage II-IV cancers than in those with stage I cancer. Significant differences in IAP concentration were observed depending upon tumor size, tumor depth, lymph node status and CRP values. A high IAP concentration, more than 500 micro g/mL, was an independent prognostic factor. Thus, a high IAP concentration is associated with tumor progression and poor survival in patients with esophageal squamous cell carcinoma.

Aged↗
PubMed2002

Effects of the concomitant administration of tamsulosin (0.8 mg) on the pharmacokinetic and safety profile of intravenous digoxin (Lanoxin) in normal healthy subjects: a placebo-controlled evaluation.

A 20-day, nonrandomized, open-label, placebo-controlled study was performed to investigate whether concomitant administration of tamsulosin (0.8 mg) affects the pharmacokinetic and safety profile of intravenous digoxin (0.5 mg) in healthy subjects. Ten healthy subjects aged 21-39 years received a single oral dose of placebo on study days 1-8 and tamsulosin on days 9-18. Tamsulosin was initiated at 0.4 mg/day and the dose was increased to 0.8 mg/day from day 11. On days 2 and 15, subjects received a single intravenous dose of digoxin (0.5 mg). Safety monitoring was carried out throughout the study. Following digoxin administration, blood was drawn and urine collected over a 96-h period for pharmacokinetic determinations. Plasma tamsulosin concentrations were measured at regular intervals after dosing on day 15. The digoxin pharmacokinetic parameters with and without concomitant tamsulosin were compared. No significant difference was observed, and no irregularity was found in the plasma tamsulosin concentration data. Six subjects experienced adverse events while receiving placebo and seven while on tamsulosin. The most frequent adverse event was mild dizziness reported by four subjects. Moderate chest pain was reported in two subjects, but this was not considered to be related to the administration of the study medications. Some significant changes in vital signs were observed; however, none was accompanied by symptoms of medical concern. These changes were not temporally related to the administration of study drugs. Thus, concurrent administration of digoxin with tamsulosin did not produce any change in the pharmacokinetics of digoxin and the safety profile was acceptable. As reflected in the prescribing information for tamsulosin, no adjustment in tamsulosin dosing is required when it is administered concomitantly with digoxin.

Administration, Oral↗
PubMed2001

The complete DNA sequence of the mitochondrial genome of Physarum polycephalum.

The complete sequence of the mitochondrial DNA (mtDNA) of the true slime mold Physarun polycephalum has been determined. The mtDNA is a circular 62,862-bp molecule with an A+T content of 74.1%. A search with the program BLAST X identified the protein-coding regions. The mitochondrial genome of P. polycephalum was predicted to contain genes coding for 12 known proteins [for three cytochrome c oxidase subunits, apocytochrome b, two F1Fo-ATPase subunits, five NADH dehydrogenase (nad) subunits, and one ribosomal protein], two rRNA genes, and five tRNA genes. However, the predicted ORFs are not all in the same frame, because mitochondrial RNA in P. polycephalum undergoes RNA editing to produce functional RNAs. The nucleotide sequence of an nad7 cDNA showed that 51 nucleotides were inserted at 46 sites in the mRNA. No guide RNA-like sequences were observed in the mtDNA of P. polycephalum. Comparison with reported Physarum mtDNA sequences suggested that sites of RNA editing vary among strains. In the Physarum mtDNA, 20 ORFs of over 300 nucleotides were found and ORFs 14 19 are transcribed.

Amino Acid Sequence↗
PubMed2001

Spontaneous reduction in Epstein-Barr virus (EBV) DNA copy number in EBV-infected epithelial cell lines.

We found that spontaneous and 12-0-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus (EBV) reactivation occurred in short-term (ST)-cultured EBV-infected epithelial cell lines GT38 and GT39 after their establishment; however, it diminished in the long-term (LT)-cultured cells passaged for more than 2 years from ST-cultured cells. We hypothesized that the EBV reactivation may be related to the EBV DNA copy number in the cells. A higher level of EBV DNA content was detected in ST-cultured cells than in LT-cultured cells by Southern hybridization using an EBV DNA XhoI probe. Fluorescence in situ hybridization using EBV DNA BamHI W fragments showed that ST-cultured cells contained a higher EBV DNA copy number than that of LT-cultured cells. EBV DNA-negative cells were detected in small proportions in LT-cultured cells, but were undetected in ST-cultured cells. These results demonstrate that EBV genomes are not maintained stably in the cell lines, and some of them are lost in continuous passages of the cells. We discuss the mechanisms of reduction of EBV reactivation and EBV DNA in the cell lines.

Animals↗
PubMed2001

[Indications for surgery for morbid obesity and effectiveness of bariatric surgery].

In this paper we describe a history and technical aspects of bariatric surgery. And surgical techniques of Divided Vertical Banded Gastroplasty and perioperative management are presented. Our indications for surgery for morbid obesity are almost equal to the guidelines for obesity surgery adopted by the American Society for Bariatric Surgery October 1986. From 1982 to 2000, 64 bariatric surgical procedures were performed at the author's institution. Vertical banded gastroplasty was performed in 45 patients, Horizontal gastric partitioning in 8 patients, Gastric bypass in 10 patients, and Divided vertical banded gastroplasty in 1 patient. The average weight loss one year after Vertical banded gastroplasty is 1/3 of the patient weight. Most of the preexisting comorbid conditions related to the obesity showed improvement or were completely resolved after surgery. No major complications were observed postoperatively. We concluded that surgical procedures for morbid obesity are very effective therapy.

Gastric Bypass↗
PubMed2001

[Effect of different concentrations of tranilast on posterior capsule opacification].

PURPOSE: To evaluate the effect of different concentrations(0.5, 1.0, 2.0%) of tranilast eyedrops in preventing fibrous posterior capsule opacification (PCO) in rabbits. METHODS: Experimental phacoemulsification procedures and in-the-bag placement of intraocular lens(IOL) implant were performed. An anterior eye segment analysis system(EAS-1000, Nidek Co, Ltd) was used to evaluate the degree of PCO during 5 weeks after surgery. RESULTS: The development of PCO was significantly suppressed in the eyes treated with tranilast eyedrops from 1 week after surgery. The mean PCO density after treatment with 0.5% tranilast was 59.1 +/- 9.3 (mean deviation +/- standard error) and 57.1 +/- 8.2, while for 1.0% tranilast it was 40.1 +/- 6.8 and 46.6 +/- 8.4, and for 2.0% tranilast it was 38.5 +/- 6.0 and 37.5 +/- 5.6 (computer compatible tape, CCT) at 1 week and 5 weeks, respectively. In the control group, the mean PCO density was 89.3 +/- 10.4 and 137.4 +/- 32.8 at 1 week and 5 weeks, respectively(p < 0.05). However, no significant statistical difference was observed in any of the findings for the 3 different tranilast concentrations. CONCLUSION: These results suggest that the 0.5% tranilast eyedrops, which are already available on the market, are sufficiently effective for inhibiting PCO.

Animals↗
PubMed2001

[Breast cancer].

Neoadjuvant chemotherapy (NAC) represents a new approach based on sound theoretical, pharmacokinetic, and experimental principles. The purpose of NAC is to improve control of the primary site by downstaging and to improve control of micrometastatic disease. NAC has been standard therapy in the management of locally advanced breast cancer. Patients with earlier stage breast cancer may also benefit from treatment with NAC. Recently some investigators have mentioned that NAC can be used instead of adjuvant chemotherapy and would be most appropriate for patients who wish to preserve their breast but who have tumors too large for breast conserving surgery. In this article, we reviewed the present status of NAC (indication, clinical response, pathologic response, survival, possibility of breast conservation, prognostic/predictive factors, neoadjuvant endocrine therapy) and discussed several unanswered questions on NAC (survival benefit, optimal number of treatment cycles, optimal regimens) and future direction. Combined modality therapy including NAC appears to provide excellent local control, the possibility of breast conservation, and, probably, an increased survival rate, at least for some subsets of patients. Furthermore, through sequential sampling, NAC provides indeed the opportunity to identify molecular mechanisms associated with pathologic response and to study the possibility to guide the choice for induction treatment and patient populations submitted to neoadjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Tumorigenesis of Epstein-Barr virus-positive epithelial cell lines derived from gastric tissues in the SCID mouse.

To study the tumorigenesis of Epstein-Barr virus (EBV)-positive epithelial cell lines GT38 and GT39 derived from human gastric tissues, we inoculated these cells under the skin of severe combined immunodeficient (SCID) mice. The development of tumors was observed in each of the mice about 2 months after the inoculation. The tumors were diagnosed with undifferentiated carcinoma by hematoxylin/eosin staining. EBV-encoded small RNA1 was detected in the paraffin-embedded tumor sections. The tumor cells had human chromosome. The circular, but not linear, EBV DNA was detected in the tumors. The molecular sizes of EBV DNA termini were the same as that of the inoculated GT38 or GT39 cells. The expressions of EBV nuclear antigen 2 and latent membrane protein 1 reduced in the tumors. Transcripts of BamHI C and W promoters in latency III were detected in the tumors and the cultured cells in vitro. The tumor cells were passaged from one SCID mouse to other SCID mice and to cultures in vitro. This is the first evidence that the EBV-positive epithelial cell lines produced tumors in the SCID mouse.

Animals↗
PubMed2000

Comparison of the effects of zolpidem and zopiclone on nocturnal sleep and sleep latency in the morning: a cross-over study in healthy young volunteers.

Zolpidem (ZOL) and zopiclone (ZPC) are non-benzodiazepine hypnotics, with unique effects on sleep architecture compared with conventional benzodiazepines. The two compounds have different profiles in action to two major subtypes of the GABA-A receptors, therefore different effects on sleep structure may be expected. In the present study, the effects of ZOL (10mg) and ZPC (7.5mg) were compared in nine healthy young male subjects during nine-night sessions, employing a crossover design. Time courses during the sessions were significantly different between the compounds in the ratio (%) of S2 and S1. Compared to the baseline, an increase of S2 and a decrease of S1 and SR were caused by ZPC, not by ZOL. SWS was increased by both ZPC and ZOL. Significant changes by ZOL were found during the first 150-min, while changes by ZPC were mostly observed during the second 150-min. This might be related to their half-lives. ZOL did not affect sleep latency in the morning, while ZPC caused a significant decrease. Subjective sleepiness, however, was not increased in the ZPC or ZOL mornings. It was speculated that difference in the action to the GABA-A receptor subtypes might be related to the differences in the effects on the sleep architecture between the compounds.

Adult↗
PubMed2000

Emergency abdominal surgery in patients aged 80 years and older.

The outcome of emergency abdominal surgery in elderly patients remains unsatisfactory. We studied factors contributing to the outcome of abdominal emergency surgery in elderly patients, particularly in those aged 80 years and older. Subjects were 61 patients aged 80 years and older (group A) and 108 patients aged from 65 to 79 years (group B) who underwent emergency abdominal surgery between 1983 and 1997. Complications were significantly higher in group A than in group B, with respiratory failure the most common postoperative complication. Mortality rate within 30 days after surgery was also higher in group A (9.8%) than in group B (3.3%). Complications and mortality did not differ significantly between those with and without preexisting concomitant disease in group A. Systemic inflammatory response syndrome (SIRS) was seen in 35 patients in group A and 50 in group B. Severe complications occurred in 62.5% of group A with preoperative SIRS. Mortality in those with SIRS was significantly higher than those without. SIRS is thus a feasible predictor of poor outcome in patients aged 80 years and older who have emergency abdominal surgery and in those aged from 65 to 79 years. Patients with SIRS should initially receive minimal treatment whenever possible, rather than be overtreated, until their conditions stabilize.

Abdomen↗
PubMed2000

Differential effect of TPA on cell growth and Epstein-Barr virus reactivation in epithelial cell lines derived from gastric tissues and B cell line Raji.

We characterized the cell growth and Epstein-Barr virus (EBV) reactivation for EBV infected epithelial cell lines, GT38, GT39, and GTC-4 using 12-O-tetradecanoylphorbol-13-acetate (TPA). These cell lines grew similarly in liquid medium, and formed colonies in soft agar. The cell growth was inhibited with TPA, dose-dependently in liquid medium. The colony formation was enhanced with low concentrations of TPA, but was inhibited with high concentrations. The latent EBV was reactivated with high concentrations of TPA as shown by the expression of EBV BZLF1 gene product ZEBRA. The effects of TPA on GTC-4 were compared with a Burkitt's lymphoma cell line Raji. The mode of actions of TPA in GTC-4 was different from Raji in terms of cell growth and EBV reactivation. The effective concentrations of TPA for cell growth inhibition and EBV reactivation were higher in Raji than GTC-4. Cell cycle analysis showed that TPA (20 ng/ml) induced cell cycle arrest to Raji but not to GTC-4; however, the rate of trypan blue stained cells increased in the TPA treated GTC-4 but not Raji. These results demonstrated that TPA affects differentially for the stimulation and inhibition of cell growth, and also EBV reactivation depends on TPA concentrations and cell types.

Blotting, Western↗
PubMed2000

Superiority of a new UICC-TNM staging system for gastric carcinoma.

BACKGROUND: The definition of the degree of lymph node metastasis (n-classification) for gastric cancer differs greatly in the new Union Internationale Contre le Cancer--TNM classification (5th edition) and the Japanese gastric cancer classification (JGC). The feasibility of the new TNM classification is evaluated in comparison with the JGC. METHODS: At Chiba University, 940 patients who underwent a gastrectomy were retrospectively classified into appropriate stages with both the TNM and JGC systems, and the survival curves of the respective stages were also compared. RESULTS: Patients with 1 to 6 metastatic nodes (TNM-pN1) showed similar survival rates whether the metastases were limited to the perigastric area (JGC-n1) or reached distant areas (JGC-n2). The patients with node metastasis that was limited to the perigastric area (JGC-n1) had significantly different survival rates, depending on the number of metastatic nodes (TNM-pN1 or pN2, P = .022). A similar phenomenon was also observed in patients with TNM-N2 and JGC-n2. A multivariate analysis indicated the TNM N-classification, rather than the JGC n-classification, as an independent prognostic factor. CONCLUSIONS: The new TNM classification appears to be a better prognostic indicator than the JGC system for patients with gastric carcinoma.

Female↗
PubMed2000

Clinical benefits of steroid therapy on surgical stress in patients with esophageal cancer.

BACKGROUND: Despite improvements in surgical techniques and perioperative care, severe complications lead to long hospital stays for some esophageal cancer patients. The purpose of this study was to evaluate the safety and effectiveness of perioperative steroid therapy on the postoperative clinical course. METHODS: Fifty-seven patients operated for esophageal cancer in 1997 and 1998 were treated with perioperative steroid therapy. Fifty consecutive patients operated in 1995 and 1996 served as a control group. In the steroid group, each patient was given 250 mg of methylprednisolone intravenously before operation followed by 125 mg on postoperative days 1 and 2. Serum interleukin-6, polymorphonuclear cell elastase, and C-reactive protein levels, and the postoperative clinical course were compared between the groups. RESULTS: Morbidity rates including hyperbilirubinemia, anastomotic leakage, and liver dysfunction were significantly lower in the steroid group than in the control group. Days until extubation and hospital stay were significantly shorter for the steroid group. Inflammatory mediators, body temperature, heart rate, and respiratory index after the surgical procedure were significantly lower in the steroid group. Adverse effects possibly caused by steroid therapy were not observed. CONCLUSIONS: Perioperative steroid therapy was safe and effective for the inhibition of inflammatory mediators and the improvement of the postoperative clinical course of patients with esophageal cancer.

Acute-Phase Proteins↗
PubMed2000

[Evaluation of a new method for antifungal drugs susceptibility testing to yeasts].

We compared the Etest with a broth microdilution method (FP panel), performed according to the National Committee for modified Clinical Laboratory Standards (NCCLS) document M27-P guidelines, for determining the MICs of 81 clinical isolates of yeasts (7 Candida albicans, 8 Candida glabrata, 10 Candida parapsilosis, 6 Pichia anomala, 10 Candida tropicalis, 4 Candida guilliermondii, 4 Candida krusei, 6 Trichosporon cutaneum, 5 Candida ciferrii, 3 Candida famata, 4 Candida norvegensis, 2 Rhodotorula rubra, 3 Candida lusitaniae, 2 Candida curvata, 1 Candida inconspicua, 1 Candida intermedia, 1 Candida colliculosa, 1 Cryptococcus spp, 1 Tricosporon capitatum, 1 Pichia ohmeri, 1 Saccharomyces cerevisiae). The Etest results for 6 ATCC standard strains correlated well with reference MICs except those of flucytosine (5-FC) for C. krusei, which tended to be 1 to 2 log2 dilution higher than the MIC range determined by NCCLS guidelines. However, the best agreement between the results for clinical isolates was seen with 5-FC (100% agreement [Within +/- 2 log2 dilutions] between the results of the two methods). There was a 91.4% agreement between the results of the two methods with amphotericin B (Etest MICs tended to be 1 to 2 log2 dilution lower than those of the FP panel). The Etest results with litraconazole for clinical isolates except C. tropicalis were similar to MICs of the FP panel (Etest for C. tropicalis showed 1 to 2 log2 dilution lower than FP panel). Also, the Etest results with fluconazole for clinical isolates except C. tropicalis were similar of 1 log2 dilution higher than MICs of the FP panel (Etest for C. tropicalis showed more than 2 log2 dilution lower than FP panel). These results showed a good level of overall agreement between the Etest method and the broth microdilution test (FP panel). Since the Etest is a less laborintensive and much simpler method, it appears to be a useful procedure for testing the susceptibility of yeasts to antifungal agents.

Antifungal Agents↗
PubMed2000

[Extended-spectrum beta-lactamase (ESBL) produced by Escherichia coli and Klebsiella pneumoniae isolated from Teikyo University Hospital--the second report].

We studied the high-level resistant to cefotaxime (CTX, MIC > or = 512 micrograms/ml) clinical isolates of Escherichia coli and Klebsiella pneumoniae in Teikyo University Hospital. The CTX-resistance could be transferred to E. coli K-12 chi 1037 or ML4903 strains from 30 of the 33 isolates by conjugation at a frequency of 10(-4). When the hydrolysis rate of benzylpenicillin was 100%, the beta-lactamases which were extracted from the transconjugants hydrolyzed CTX, CAZ and AZT at the rate of 38-95%, 0-8.6% and 0-56%, respectively. These results demonstrate that these enzymes should be categorized into ESBL. The nucleotide sequence of CTX-resistant gene was identified to that of the CTX-M2 gene which was first described in Argentina. It was found to have 99.9% homology to Toho-1 gene in Japan and 99.6% homology to CMY-2 gene. Using a PCR methods for the detection of one of ESBL gene such as CTX-M2, Toho-1 or CMY-2, the DNA was amplified from all strains (11 isolates of E. coli and 21 isolates of K. pneumoniae).

Cefotaxime↗