Biomedical subjects

H Orita

Publications and source records attributed to H Orita.

132 records · Page 8Linked to original sources

PubMedDate not supplied

Inhibition of postsurgical adhesions in a standardized rabbit model: intraperitoneal treatment with tissue plasminogen activator.

The direct effects of tissue plasminogen activators (TPA) delivered locally into the peritoneal cavity at the site of injury on the subsequent formation of postsurgical adhesions in rabbits were studied. A 3 x 5 cm flap of parietal peritoneum (approximately 1 mm thick) was sharply dissected from the right lateral peritoneal sidewall. The serosal surface of the adjacent small bowel was abraded with a scalpel until punctate bleeding developed. Alzet minipumps containing varying doses of TPA were sewn into the subcutaneous space with their polyethylene catheter tips leading from the pump into the peritoneal cavity, 2-3 mm over the injury test site. Within 7 days after the implantation of the pumps, the rabbits were killed and the extent of adhesions was determined. The threshold dosage at which significant beneficial antiadhesion properties are obtained was between 0.015 and 0.05 mg TPA/mL of buffer at 6 x 10(-4) mg/kg/day. Effective adhesion prevention occurred with only two days of treatment beginning the day of surgery.

Animals↗

PubMedDate not supplied

Margins of resection of the esophagus for gastric cancer with esophageal invasion.

BACKGROUND/AIMS: We retrospectively examined the rate of infiltration of proximal margins of resection in patients resected for gastric cancer with esophageal invasion. MATERIAL AND METHODS: In the 175 proximal margins examined, the incidence was related to the gross appearance, histologic type, size, depth of invasion, shape of the oral edge, length of grossly tumor-free edge and length of histologic esophageal invasion. RESULTS: Multivariate analysis indicated that undifferentiated adenocarcinoma and length of histologic esophageal invasion are significant risk factors for positive margin. Infiltration occurred in 13.7% (24 cases) of the oral margins of transection. Eight patients were potentially curative other than positive margin and 5 were caused by underestimation of the distance of oral margin. With reference to the length of margin of resection, no involvement was found when the cranial distance between the lesion and the line of transection exceeded 2 cm in patients with orally well-defined type esophageal invasion. In patients with the orally ill-defined type, transection with a distance greater than 4 cm commonly guarantee safety of the proximal margin, except for cases with lymphatic invasion. CONCLUSIONS: These data provide the surgeon with a rational basis for assessing the extent of resection when performing esophagectomy combined with gastrectomy for cancer.

Adenocarcinoma↗

PubMedDate not supplied

Transcolonic approach for a stapled end-to-end colorectal anastomosis in low anterior resection.

We designed the transcolonic approach for a stapled end-to-end colorectal anastomosis using a premium curved EEA in low anterior resection. The advantage of this repair is the elimination of transanal introduction of the stapler by a second assistant from below, which make the stapled anastomosis technically easier and safer. The fact that the anvil can be removed from the center shaft by pressing on the anvil release button allows the anvil to be released from anus, which theoretically prevents suture break down. This procedure can be considered for selected patients who have anal structure and where it is impossible to insert the instrument.

Anastomosis, Surgical↗

PubMedDate not supplied

Relationship between hormone receptor levels and cell-kinetics in human colorectal cancer.

BACKGROUND: This study was done to determine the potential role of sex steroid hormone receptors in the development of human colorectal cancer. METHOD: Receptors for estrogen (ER) and progesterone(PgR) were investigated in surgical specimens from 22 patients with colorectal cancer, using enzyme immunoassay. These values were examined in relation to cell kinetics parameters determined by DNA flow cytometry. RESULTS: ER and PgR were detected in 27% and 41%, respectively. There were no significant differences in the expression of ER or PgR according to the age, sex of the patients, tumor size, location, histological differentiation and lymph node metastasis. Although ER status appeared to be independent of DNA parameters, there were better correlations of PgR-negative tumors with increased hyperaneuploid levels. There were significantly higher values of heterogeneity index score in PgR-negative tumors compared with PgR-positive tumors. In the multiple regression analysis, PgR levels proved to be a major independent factor for changes in DNA index and heterogeneity index score. CONCLUSION: The PgR status is a critical factor for determining the proliferative activity of colorectal cancer tissue and may play a biological role in regulating the growth of the tumor.

Adenocarcinoma↗

PubMedDate not supplied

c-erbB-2 expression is predictive for lymphatic spread of clinical gastric carcinoma.

BACKGROUND/AIMS: In patients with gastric carcinoma, the prognostic significance of c-erbB-2 oncogene expression was elucidated, but its role in the aggressive behavior of tumors is not clear. PATIENTS AND METHODS: We asked whether or not cerbB-2 gene expression may have predictability with regard to the metastatic potential in 160 patients with gastric carcinoma using a immunohistochemical staining and a multivariate analysis. RESULTS: c-erbB-2 immunoreactivity was observed in 11% (17/160) of tumors. Patients with c-erbB-2 product positive tumors had a significant shorter prognosis (p < 0.05), and were characterized by a high incidence of peritoneal dissemination (41%), liver metastasis (18%) and lymph node involvement (94%). In the multivariate logistic analysis revealed that c-erbB-2 expression was a significant risk factor related to lymph node involvement (p < 0.01). CONCLUSIONS: Our multivariate analysis revealed that c-erbB-2 expression is linked to the metastatic potential in patients with gastric carcinoma.

Female↗

PubMedDate not supplied

Metastatic potential of colorectal adenoma containing carcinoma determined by pre-operative assessment of morphology.

BACKGROUND/AIMS: Colectomy with lymphadenectomy is sometimes considered to be the appropriate management for patients with colorectal carcinoma in adenoma invading beyond the muscularis mucosa. Our study was done to determine whether gross features of the tumor would provide information to predict the metastatic potential. MATERIAL AND METHODS: Thirty one carcinomas in adenomas from 29 patients were surgically resected. Macroscopic findings with regard to size and morphologic type were compared with the presence or absence of lymph node metastasis and vessel invasion. RESULTS: The rate of lymph node metastasis in all cases was 20.0% (6/30). Lymphatic and venous invasion was also identified in 7 (22.6%) and 5 (16.1%) cases, respectively. There was no evidence of nodal involvement in pedunculated lesions, but the incidence of nodal involvement was 18.8% and 60.0% in sessile and protruded tumors, respectively. There was a significant correlation between morphologic type and the incidence of lymph node metastasis. The mean size of node positive tumors was 5.9 cm with a range of 3.8-9.0 cm, that is significantly larger than the value of 3.8 cm in cases of node negative tumors. All the node positive tumors exceeded 3.5 cm. With adjustment made for the morphology, the estimated risk of nodal involvement of tumors with a sessile shape and larger than 3.5 cm was 33.3%. Therefore, both large sessile and protruded types mean a high risk for lymph node metastasis. CONCLUSIONS: Macroscopic features, size and gross type are critical factors in determining the metastatic potential of carcinoma in colorectal adenoma. We recommend segmental colectomy with lymphadenectomy for such patients.

Adenoma↗