Biomedical subjects

Manabu Arai

Publications and source records attributed to Manabu Arai.

7 recordsLinked to original sources

PubMed2006

Priming ditransitive structures in comprehension.

Many studies have shown evidence for syntactic priming during language production (e.g., Bock, 1986). It is often assumed that comprehension and production share similar mechanisms and that priming also occurs during comprehension (e.g., Pickering & Garrod, 2004). Research investigating priming during comprehension (e.g., Branigan, Pickering, & McLean, 2005; Scheepers & Crocker, 2004) has mainly focused on syntactic ambiguities that are very different from the meaning-equivalent structures used in production research. In two experiments, we investigated whether priming during comprehension occurs in ditransitive sentences similar to those used in production research. When the verb was repeated between prime and target, we observed a priming effect similar to that in production. However, we observed no evidence for priming when the verbs were different. Thus, priming during comprehension occurs for very similar structures as priming during production, but in contrast to production, the priming effect is completely lexically dependent.

Cognition↗

PubMed2006

Dynamic enhanced MRI predicts chemosensitivity in breast cancer patients.

BACKGROUND: Primary chemotherapy for breast cancer is effective as postoperative adjuvant therapy. However, one of the critical disadvantages was a treatment delay for patients with progressive disease. The present study attempts to clarify quantitative parameters on MRI which can be used to predict the sensitivity to treatment in breast cancer patients. METHODS: The subjects consisted of 26 patients with invasive ductal breast cancer who received primary chemotherapy before surgery. The mean maximum tumor dimension was 3.3cm, and 21 cases had nodal involvements. Three cases demonstrated histological grade 3. Dynamic enhanced MRI was evaluated at three different time periods; prior to, in the midst of preoperative chemotherapy, and just before the initial operation. The signal intensity ratio (SIR) and early contrast uptake (ECU) were calculated, as well as the correlation between these dynamic data and the tumor reduction rates were analyzed retrospectively. P-values of less than 0.05 were considered to indicate statistically significant. RESULTS: Responders to chemotherapy had the significantly higher SIR and ECU values than non-responders (p=0.0454 and 0.0334, respectively). ECU value significantly decreased as tumor reduction by chemotherapy (p=0.0028). Pathological tumor dimension was significantly correlated with the tumor size estimated on presurgical MRI (p<0.0001). CONCLUSIONS: Our current series demonstrated the significant correlation between pretreatment MRI data and tumor reduction by chemotherapy in breast cancer patients. With these results, it seems possible to define good and non-responders prior to treatment.

Adult↗

PubMed2005

Progesterone regulation of the expression and function of multidrug resistance type I in porcine granulosa cells.

P-glycoprotein (P-gp) coded with the multidrug resistance type I (MDR1) is expressed in various normal tissues including ovaries and may function as detoxification and steroid transport. The present study was performed to analyze the expression and function of MDR1 in granulosa cells stimulated with FSH, LH, estradiol-17beta (E) and progesterone (P). The granulosa cells isolated from porcine ovarian follicles were cultured for 24h in a serum-supplemented medium, and then cultured for 48h with the hormones in a serum-free culture medium. MDR1 was highly expressed in large follicles and induced in cultured granulosa cells stimulated with LH as revealed by RT-PCR. Highly expressed MDR1 resulted in the increased P-gp activity. However, FSH had no effect. P significantly increased the MDR1 expression and P-gp activity in the cells stimulated with LH, whereas E had no stimulatory effect. Aminoglutethimide suppressed the MDR1 expression and P-gp activity, but which were completely restored by P. These results indicate that P participates in MDR1 expression and P-gp function of granulosa cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2005

Development of multidrug resistance type I P-glycoprotein function during in vitro maturation of porcine oocyte.

The present study was performed to evaluate the expression and function of P-glycoprotein (P-gp) encoded the multidrug resistance type I (MDR1) gene, protecting from xenotoxics, in porcine oocyte during in vitro maturation. Cumulus-oocyte complexes (COCs) were cultured to obtain the germinal vesicle (GV), first metaphase and second metaphase (MII) oocytes. The P-gp function was assessed by means of the rhodamine 6G (R6G) efflux from oocytes with P-gp inhibitors such as verapamil and PSC-833. The MDR1 transcript was detected in the GV and MII oocytes by RT-PCR analysis using primer sets based on the human gene. P-gp inhibitors significantly blocked the R6G efflux from the MII oocytes, whereas the reagents were ineffective in the GV oocytes. The R6G efflux from oocytes was accelerated at the MII stage more than at the GV stage. Thus, the MDR1-type P-gp function is poor at the GV stage, but the function improves during oocyte maturation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Early results of intersphincteric resection for patients with very low rectal cancer: an active approach to avoid a permanent colostomy.

PURPOSE: Abdominoperineal resection has been the standard surgery for very low rectal cancer located within 5 cm of the anal verge. However, permanent colostomy exerts serious limitations on quality of life. The present study aimed to investigate curability and functional results of intersphincteric resection and additional partial external sphincteric resection for carcinoma of the anorectal junction. METHODS: Thirty-five patients were prospectively studied from November 1999 to September 2002. All patients displayed adenocarcinoma (T3: n = 26; T2: n = 7; T1: n = 2) located between 0 and 2 cm above the dentate line. Abdominotransanal rectal resection with total mesorectal excision was performed in all patients (total intersphincteric resection: n = 14; subtotal intersphincteric resection: n = 5; additional partial external sphincteric resection: n = 6). All patients underwent diverting colostomy, which was closed at a median of six months postoperatively. Twenty patients received preoperative radiochemotherapy. RESULTS: All patients had curative intent with microscopic safety margins (mean surgical cut end: 4 mm; mean distal cut end: 10 mm). No postoperative mortality was encountered. Morbidity was identified in 13 patients (perianastomotic abscess: n = 4; anastomotic leakage and fistula: n = 4; postoperative bleeding: n = 2; wound infection: n = 1; anastomotic stenosis: n = 1; anovaginal fistula: n = 1). One of these patients received a permanent colostomy. Five patients developed recurrence (liver: n = 1; lung: n = 2; local and lung: n = 1; abdominal wall: n = 1) during the median observation period (23 months). Two of these patients underwent curative resection of liver or lung metastases. Twenty-one patients have received stoma closure, and although continence was satisfactory in all, 5 displayed occasional minor soiling 12 months after stoma closure. Anal canal manometry demonstrated significant reduction in maximum resting pressure (median: 50 cmH(2)O at 12 months after stoma closure), but acceptable function results were obtained. CONCLUSION: Curability and anal function were achieved by means of intersphincteric resection without or with additional partial external sphincteric resection. These procedures can be recommended for low rectal cancer patients who are candidates for abdominoperineal resection.

Adenocarcinoma↗

PubMed2004

Estrogen regulation of nitric oxide synthesis in the porcine oocyte.

The endothelial type (NOS-3) of three isoforms of nitric oxide (NO) synthase occurs in porcine oocytes and granulosa cells, but the regulation of NO synthesis in oocytes remains unknown. The present study was designed to evaluate steroid control in the process of oocyte NO synthesis. Cumulus-oocyte complexes (COCs), obtained from small-sized antral follicles of immature porcine ovaries, were cultured in estrogen-deprived medium, and the effect of steroids or steroid-free porcine follicular fluids on the NO release from oocytes was investigated. Oocytes that were isolated from cultured COCs were incubated with 1 microM ionomycin. The NO metabolites were identified using a NO detector-high-pressure liquid chromatography system. Oocytes from COCs cultured with 10 nM 17beta-estradiol (E2) released NO in response to ionomycin, whereas progesterone and testosterone had little effect on the synthesis of NO. An inhibitor of NOS suppressed the synthesis of NO. The maximal synthesis was observed after a 15 h-culture with E2. However, oocytes freshly obtained from antral follicles did not response to ionomycin, and the E2 action was suppressed by the addition of steroid-free follicular fluids. Analyses of RT-PCR and Western blotting showed that E2 did not increase NOS-3 expression. In addition, estrogen receptor beta was detected in oocytes and cumulus cells, and estrogen receptor alpha was detected only in cumulus cells. These findings suggest that oocyte NOS-3 is promoted for the synthesis of NO by E2 without increases in NOS-3 expression, but the synthesis of NO is suppressed, at least in the oocytes of early antral follicles.

Animals↗

PubMedDate not supplied

Port site recurrence diagnosed by positron emission tomography after laparoscopic surgery for colon cancer.

Port site recurrence after laparoscopic surgery for colorectal cancer patients is a rare complication. We report a case of port site recurrence in a 46-year-old woman that was detected by positron emission tomography (PET) using 18[F]-fluoro-deoxyglucose (FDG). Surgical treatment consisted of laparoscopic ileo-cecal resection and lymph node dissection. At her nine months postoperative follow-up examination, her serum carcinoembryonic antigen (CEA) levels had raised to 15.8ng/mL. Although computed tomography and colonoscopic examination were performed, lung, liver and local recurrence in the colon were not detected. FDG-PET was then performed and detected a higher concentration of FDG at the port site in the abdominal wall. Port site recurrence was diagnosed clinically and surgical resection of tumor at the port site was performed. Pathology revealed a moderately differentiated adenocarcinoma diagnosed as port site recurrence. This case suggests that FDG-PET is an important examination for the detection of port site recurrence when serum CEA levels are rising and routinely radiographic examinations are unable to detect the site of recurrence.

Cecal Neoplasms↗