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Biomedical subjects

K Orita

Publications and source records attributed to K Orita.

At least 55 records · Page 3Linked to original sources
PubMed1996

Postoperative adjuvant randomised trial comparing chemoendocrine therapy, chemotherapy and immunotherapy for patients with stage II breast cancer: 5-year results from the Nishinihon Cooperative Study Group of Adjuvant Chemoendocrine Therapy for Breast Cancer (ACETBC) of Japan.

Between 1985 and 1988, the effect of using ftorafur (FT) or PSK (an immunotherapy agent) in combination with the conventional postoperative adjuvant therapy using mitomycin (MMC) plus tamoxifen (TAM) was assessed in stage II, oestrogen receptor-positive (ER+) breast cancer patients. Furthermore, in ER- breast cancer stage II patients, the effects of postoperative adjuvant therapy using MMC plus FT were compared with the effects of postoperative adjuvant therapy using MMC plus PSK. Patients had primary stage II breast cancer and had undergone total mastectomy plus axillary dissection or more radical surgery. On the day of surgery, MMC (13 mg/m2) was administered intravenously. Then, ER+ patients received one of three regimens of drug therapy, starting 2 weeks after surgery: regimen A (daily oral treatment with 30 mg of TAM), regimen B (daily oral treatment with 30 mg of TAM and 600 mg of FT) or regimen C (daily oral treatment with 30 mg of TAM and 3 g of PSK) [corrected]. ER- patients received either regimen D (daily oral treatment with 600 mg of FT) or regimen E (daily oral treatment with 3 g of PSK), starting 2 weeks after surgery. Of the 540 ER+ patients registered, 525 were evaluated. The 5-year overall survival rate for ER+ patients was higher for patients who received regimen B (94.2%) than for those who received regimen A (86.9%) or regimen C (89.9%) (P = 0.063). The 5-year relapse-free survival rate was higher for regimen B (88.9%) than for regimen A (78.6%) and regimen C (77.2%) (P = 0.010). Stratified analysis revealed better results with the FT-combined therapy in patients positive for lymph node metastasis and premenopausal patients. These results indicate the effectiveness of using FT in combination with TAM. Of the 376 ER- patients registered, 364 were evaluated. The 5-year overall and relapse-free survival rate for ER- patients did not differ significantly between patients who received regimen D and those who received regimen E.

Adult↗
PubMed1996

Changes in cellular ultrastructure induced by gamma-interferon in K562 cells may be prerequisite for apoptosis.

We report here the time-course of electron microscopic changes induced by gamma-interferon (IFN-gamma) in the human erythromyeloid leukemia cell line K562. In K562 cells treated with IFN-gamma for 6h, the nuclei were polygonal in shape and microvilli were far more abundant on cell membranes compared with control K562 cells, and invaginations were often seen in the cell membranes. There was a reduction in the number of cell-membrane microvilli and an increase in the number of lysosomal bodies in the cytoplasm of K562 cells treated with IFN-gamma for 12h. After treatment with IFN-gamma for 24h, the cell membrane microvilli disappeared, large numbers of cellular organelles were observed, such as mitochondria and lysosomes, and the cytoplasm became electron-dense. Cytoplasmic vesicles and vacuoles were also observed. These vesicles may correspond to an intermediate step in the ultimate cellular disintegration associated with apoptosis caused by IFN-gamma.

Apoptosis↗
PubMed1996

Postoperative gastric motility, secretory function, and pre- and postoperative carbohydrate metabolic states in esophageal cancer patients.

This study was undertaken to assess postoperative gastric motility and gastric acid secretion, and pre- and postoperative carbohydrate metabolism in patients with esophageal cancer. The gastric motility was compared among 3 different reconstruction routes in 26 patients who were divided into 2 groups according to the duration of postoperative follow-up; group A, 3 months or less; and group B, 18 months or more. The routes used for subtotal resection of the stomach were the posterior mediastinal, retrosternal, and subcutaneous routes. All patients showed positive resting pressure in the esophagus, but peristaltic waves did not reach the gastric tube at dry swallowing in any patients and peristaltic waves appeared after eating pudding only in 1 patient in group B. The resting pressure and gastric emptying time were similar among reconstruction routes, but the incidence and amplitude of metoclopramide (MCP)-induced peristaltic waves were significantly higher in group B than in group A. Furthermore, 24-h intragastric pH monitoring of gastric secretion in a group of 9 patients revealed individual variation in gastric secretion. Some patients showed high acidity soon after operation, suggesting the need for prophylactic treatment for preventing gastric ulcer. Postoperatively, postprandial serum gastrin levels were significantly higher than preoperative levels. In the other group of 11 patients tested, preoperative and postoperative carbohydrate metabolism were not significantly different. Postoperatively, carbohydrate metabolism recovered to preoperative levels after a transient decrease. These results demonstrated that postoperative motility improved over time although no difference was found among the 3 reconstruction routes used.

Adult↗
PubMed1996

Pancreaticogastrostomy: effect of partial gastrectomy on the pancreatic stump in rabbits.

To assess the influence of digestive juice on the pancreatic stump when pancreaticogastrostomy was performed after pancreatoduodenectomy, the pancreatic stump was anastomosed to the intact stomach (group I), the stomach after partial gastrectomy (group II), or the jejunum (group III) in rabbits, and the nature of the digestive juice at the anastomotic site as well as the histologic changes of the pancreatic tissue were investigated. The digestive juice was highly acidic in group I, slightly acidic in group II, and almost neutral in group III. Histological examination of the pancreatic stump revealed extensive coagulative necrosis and delayed replacement with granulation tissue in group I, while there was less prominent liquefactive necrosis and early replacement with granulation tissue in groups II and III. Intraperitoneal abscess formation around the anastomotic site and atrophic fibrosis of the pancreas (similar to the changes after pancreatic duct ligation) occurred in 27.8% and 46.2% of group I rabbits, respectively, but no such changes were detected in groups II and III (both P < 0.05). These results indicate that the highly acidic gastric juice had a widespread corrosive effect on the anastomosed pancreatic tissue, and that partial gastrectomy may be necessary to prevent anastomotic leakage and pancreatic duct obstruction after pancreaticogastrostomy.

Amylases↗
PubMed1996

Effect of low dose cyclophosphamide on the synthesis of acute phase protein and its significance for cancer chemotherapy.

Patients with far advanced colorectal cancers received chemotherapy consisting of low-dose cyclophosphamide (LDCY) 333 mg/m2 every four weeks intravenously and by oral administration of 5'-DFUR (a masked compound of 5-Fluorouracil). Serum levels of immunosuppressive acidic protein (IAP), an acute phase protein, were measured every four weeks for a total of thirty-one LDCY trials of ten patients. LDCY chemotherapy significantly decreased the IAP levels in cancer patients with high IAP levels. These results suggested that LDCY chemotherapy could counteract host responses against tumors and could have decreased immunosuppressive responses in cancer patients.

Acute-Phase Proteins↗
PubMed1996

A case of traumatic neuroma of the gallbladder in the absence of previous surgery and cholelithiasis.

We experienced a patient with traumatic neuroma of the gallbladder with no history of gallbladder surgery or cholelithiasis. A 74-year-old man was referred to our department after a gallbladder tumor was incidentally discovered during a preoperative screening examination for prostate hypertrophy. Ultrasonography, MRI, CT and endoscopic retrograde cholangiography revealed a protuberant lesion of the gallbladder. Laparoscopic cholecystectomy was attempted but adhesion between the liver and duodenum forced us to convert to open laparotomy. Cholecystectomy and adjacent liver tissue resection was performed. Diagnosis was made by frozen histology during operation. It revealed no malignancy. Postoperative pathological examination revealed traumatic neuroma associated with inflammation. To our knowledge, this is the first reported case of gallbladder neuroma without a history of gallstones or surgery in the English and Japanese literature since 1980. This traumatic neuroma should be considered in a differential diagnosis in treating gallbladder neoplasm, even in the absence of an operative history or cholelithiasis.

Aged↗
PubMed1996

Enhancement of experimental metastasis by gamma-interferon in a murine adenocarcinoma.

This study was conducted to examine the effect of gamma-interferon (IFN-gamma) on experimental metastasis formation by murine colon 26 adenocarcinoma in BALB/c mice. We found that the number of experimental lung metastases was increased after colon 26 cells were pretreated for 1 h with as little as 1 OIU/ml of IFN-gamma. 5-[125I] iodo-2'-deoxyuridine-radiolabeled colon 26 cells pretreated with IFN-gamma remained at higher level in the lung at 24h after intravenous injection than when the cells were not pretreated. In vivo elimination of asialo GM1-positive cells increased the number of lung metastases and, in such mice, there was no longer a difference in metastatic ability between control and IFN-gamma-treated cells. Colon 26 cells were completely resistant to lysis by isolated splenocytes. Splenocytes incubated in vitro with interleukin 2 exhibited moderate cytotoxicity against colon 26 cells, but there were no significant differences between control and IFN-gamma-treated cells. Colon 26 cells pretreated with IFN-gamma demonstrated resistance to tumor necrosis factor alpha-mediated growth inhibition. The enhancement of metastases by IFN-gamma was dependent on de novo protein synthesis since the enhancement was abolished by cycloheximide. Taken together, the data suggest that the metastatic ability of colon 26 cells pretreated with IFN-gamma is significantly higher due to the resistance to asialo GM1-positive cells accompanied with de novo protein synthesis.

Adenocarcinoma↗
PubMed1996

Oxygen-dependent inhibition of neutrophil respiratory burst by nitric oxide.

Effect of nitric oxide (NO) on the respiratory burst of neutrophils was examined under different oxygen tensions. Phorbol myristate acetate (PMA) stimulated oxygen consumption and superoxide (O2) generation in neutrophils by a mechanism which was inhibited reversibly by NO. The inhibitory effect of NO increased significantly with a decrease in oxygen tension in the medium. The inhibitory effect of NO was suppressed in medium containing oxyhemoglobin (HbO2), a NO scavenging agent. In contrast, 3-morpholinosydnonimine (SIN-1), a compound that rapidly generates peroxynitrite (ONOO-) from the released NO and O2-, slightly stimulated the PMA-induced respiratory burst. These results suggested that NO, but not ONOO-, might reversibly inhibit superoxide generation by neutrophils especially at physiologically low oxygen tensions thereby decreasing oxygen toxicity particularly in and around hypoxic tissues.

Animals↗
PubMed1996

[Expression of CD44 variant isoforms in human primary colon carcinomas and metastasis].

The CD44 is a cell adhesion molecule that is present as numerous isoforms created by mRNA alternative splicing. A variety of human carcinomas display the overexpression of CD44 variant isoforms. To identify the relationship between the expression of CD44 variant isoforms and the metastatic potential of colon carcinomas, we performed a polymerase chain reaction analysis following reverse transcriptase treatment for CD44 expression in fresh surgical specimens obtained from 25 colon carcinomas and corresponding normal colonic mucosa. The CD44H, a common type of the CD44 isoform, was amplified from all carcinomas and normal tissues, whereas a splice variant form corresponding to CD44E was expressed in 19 out of 23 colon carcinomas (83%) and 7 out of 19 normal mucosa specimens (37%), suggesting that the CD44E expression was predominantly observed in colon carcinomas compared to normal tissues (p < 0.05). The multivariant form of CD44 was identified in 10 out of 23 carcinomas (44%) and 5 out of 19 normal samples (26%). The CD44E/CD44H (E/H) ratio was significantly higher in colon carcinomas than in normal mucosa (p < 0.01). However, neither the E/H ratio nor CD44 multivariant expression correlated with the clinicopathological features. These results suggest that CD44E expression and high E/H ratio are commonly observed in colon carcinomas and that the expression of the CD44 multivariants is not associated with clinicopathological parameters.

Aged↗