Search PubMed⌕ Search

Biomedical subjects

T Kamakura

Publications and source records attributed to T Kamakura.

50 records · Page 3Linked to original sources
PubMed1991

A random allocation system with the minimization method for multi-institutional clinical trials.

This paper describes the random allocation system used to perform precise and rapid treatment assignments in multi-institutional clinical trials. This system is based on sophisticated randomization procedures, according to Pocock and Simon's minimization method and Zelen's method for institution balancing. The major advantage of randomized treatment assignments with this system is to balance treatment numbers for each level of various prognostic factors over the entire trial and at the same time balance the allocation of treatments within an institution. Therefore, the randomized treatment assignments by this system can prevent degrading of the statistical power of a particular treatment factor. This system is designed to run on a small-sized notebook computer and therefore can be set up beside a telephone for registration, without occupying a large space. At present, this system is conveniently being used in two clinical trials.

Algorithms↗
PubMed1991

Blasticidin S-resistance gene (bsr): a novel selectable marker for mammalian cells.

Blasticidin S is a microbial antibiotic that inhibits protein synthesis in both prokaryotes and eukaryotes. The blasticidin S-resistance gene (bsr), isolated from Bacillus cereus K55-S1 strain, was inserted into pSV2 plasmid vector and introduced into cultured mammalian cells by transfection. The bsr gene was integrated into the genome and conferred blasticidin S resistance on HeLa cells. The transfection frequency of the bsr gene was as high as that of the aminoglycoside phosphotransferase gene, the so-called neo gene, which is a representative selectable marker for mammalian cells. Transfectants in which several copies of bsr had been integrated into the genome were highly resistant to blasticidin S. Furthermore, blasticidin S killed the cells more rapidly than G418, which is conventionally used as a selective drug for the neo gene. Thus bsr is concluded to be useful as a drug-resistance marker for mammalian cells.

Anti-Bacterial Agents↗
PubMed1990

Expression of the blasticidin S deaminase gene (bsr) in tobacco: fungicide tolerance and a new selective marker for transgenic plants.

Blasticidin S (BS), a fungicide of microbial origin, is used for the practical control of rice blast disease. It has broad antimicrobial activity but occasionally exhibits adverse phytotoxic effects on some dicot plants. An inactivating enzyme, BS deaminase, was discovered in the BS resistant strain, Bacillus cereus K55-S1, and the structural gene, bsr, for the enzyme has been cloned. We introduced the bsr gene into tobacco plants using the Ti plasmid vector system and demonstrated that the bsr gene conferred a BS resistant phenotype to the plants. Thus the bsr gene could be useful as a selective marker for plant transformation and provides an example for a new approach to the solution of phytotoxicity problems associated with the use of some types of fungicide.

Aminohydrolases↗
PubMed1985

Point process models in asthma attacks for assessing environmental risk factors.

Point process models are reviewed and discussed for assessing the effects of environmental risk factors on asthma attacks. It is pointed out that the logit model and proportional intensity model are useful for analyzing the data based on the diaries recorded consecutively during several months or during a few years. Some covariates that seems to influence upon asthmatics are explored using these models. Further work on estimating the smoothed base-line intensity function is briefly discussed in terms of the Bayes model.

Asthma↗
PubMedDate not supplied

Endoscopic injection sclerotherapy for esophageal varices in the elderly.

A group of 1127 patients who underwent sclerotherapy for esophageal varices were compared for outcome in terms of age: over and under age 70 years. Esophageal varices were completely eradicated in 81 of 110 patients > 70 years (73.6%) and in 791 of 1017 patients < 70 years (77.8%). Gastrointestinal bleeding after sclerotherapy occurred in 9 patients > 70 years (8.2%) and in 84 of those < 70 years (8.3%). Complications occurred in 16 patients > 70 years (14.5%) and in 141 < 70 years (13.9%). Liver failure and hepatoma accounted for more than 80% of the causes of death in both groups (80.3% versus 83.8%). The 5-year cumulative survival rates in patients with bleeding esophageal varices (bleeders) without hepatoma were 21.8% in those > 70 years and 58.7% in those < 70 years (p < 0.01), the relative survivals being 25.3% versus 66.6%. Patients without hepatoma and treated by prophylactic sclerotherapy accounted for 66.2% of patients > 70 years and 61.7% of those < 70 years, the relative survivals being 75.9% versus 71.9%. As analyzed by the Cox proportional-hazards model, age > 70 years was a prognostic factor in the bleeders (p < 0.01) but not in the nonbleeders. We recommend that elderly patients with esophageal varices be given prophylactic sclerotherapy, as the outcome for these patients is poor once bleeding has occurred.

Aged↗
PubMedDate not supplied

Prognostic value of combination assays for CEA and CA 19-9 in gastric cancer.

Preoperative serum CEA and CA 19-9 levels in 158 patients with gastric cancer were analyzed with respect to prognostic factors, using univariate and multivariate analysis. The incidence of high preoperative levels of both CEA and CA 19-9 was 10.1% (16/158). 13.9% (22/158) showed high CEA levels and normal CA 19-9 levels, whereas the reverse was true in 16.5% (26/158). Neither marker showed a high level in 59.5% (94/158). The multivariate analysis showed that in addition to tumor stage, the depth of invasion, liver metastasis and peritoneal dissemination, combination assays of preoperative serum CEA and CA 19-9 levels were an independent prognostic factor. Combination assays of preoperative serum CEA and CA 19-9 will allow us to conduct a more careful postoperative follow-up of high-risk patients, and also help determine the optimum adjuvant chemotherapy.

Aged↗
PubMedDate not supplied

Influence of blood transfusion on postoperative long-term liver function in patients with hepatocellular carcinoma.

BACKGROUND/AIMS: To research for possible adverse effects of blood transfusion on liver function at a relatively long term after hepatic resection, liver function tests at one and two years after the surgery were studied in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Seventy-one patients with no evidence of cancer recurrence during two years after the surgery were selected for this retrospective analysis. Patients were divided into two groups depending on perioperative blood transfusion: those who received blood transfusion (BT(+), n = 38), and those without blood transfusion (BT(-), n = 33). RESULTS: There were no statistical difference in the preoperative clinical features including liver function tests except decreased prothrombin time index (P < 0.01) and larger amount of intraoperative blood loss (P < 0.01) in BT(+) group. Platelet counts at 2 year after the surgery were significantly higher in the BT(-) group (P < 0.05). Two-way ANOVA showed no significant difference in liver function tests between the two groups. In multiple regression analysis, blood transfusion significantly correlated with serum total bilirubin at 1 year, but did not at 2 years after the surgery. CONCLUSIONS: The influence of blood transfusion in the patients with hepatocellular carcinoma was considered to be minimum within 2 years after hepatectomy.

Analysis of Variance↗
PubMedDate not supplied

The value of prophylactic R2 lymph node dissection for gastric cancer.

Three hundred and eleven patients with an R2 lymph node dissection for gastric cancer were reviewed in order to examine the efficacy of prophylactic R2 lymph node dissection. In 246 patients, who were all macroscopically determined to have either N0 or N1 lymph node metastasis at the time of operation, 30 showed histologic lymph node metastasis in the N2 group. When the 5-year survival rates in the 61 patients with histologic N2 lymph node metastasis were compared according to the macroscopic evaluation of lymph node metastasis at the time of operation, 30 patients who were determined to have either N0 or N1 lymph node metastasis showed a better prognosis than the 31 patients who were determined to have N2 lymph node metastasis (p < 0.01). Therefore, prophylactic R2 lymph node dissection contributes to an improved prognosis for gastric cancer patients who are found to macroscopically have either N0 or N1 lymph node metastasis on the basis of an intra-operative evaluation.

Female↗
PubMedDate not supplied

Indicative value of carcinoembryonic antigen (CEA) for liver recurrence following curative resection of stage II and III gastric cancer.

BACKGROUND/AIMS: We investigated the role of preoperative and serial postoperative serum CEA levels in advanced gastric cancer patients with curative operation. MATERIALS AND METHODS: Preoperative and serum postoperative CEA levels were measured in 115 patients with Stage II and III gastric cancer and who underwent curative gastric resection. RESULTS: The 5-year survival rates of patients with high preoperative CEA levels (> 5 ng/ml) were poorer than in case of low preoperative CEA levels (< 5 ng/ml) in both stage II (P < 0.05) and stage III (P < 0.01) gastric cancer. When the site of the recurrence was diagnosed in 47 patients with less than a 5-year survival, a high level of preoperative CEA was more likely to be associated with a liver metastasis (13/18, 72.2%) than with peritoneal dissemination (4/15, 26.7%) (P < 0.05). In the course of serial measurements of postoperative levels of CEA, CEA increased in patients with liver metastasis, and CEA levels began to elevate 3.2 months before clinical detection, while, little change of postoperative serum CEA levels was noted in patients with peritoneal dissemination. CONCLUSIONS: We propose that the preoperative and serial postoperative assays of serum CEA level are predictive for liver metastasis in patients with stage II and III gastric cancer and treated by curative gastric resection.

Bone Neoplasms↗