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Biomedical subjects

T Kamakura

Publications and source records attributed to T Kamakura.

At least 37 records · Page 2Linked to original sources
PubMed1994

Univariate and multivariate analyses of the prognostic significance of discontinuous intramural metastasis in patients with esophageal cancer.

A review of 167 cases of esophageal carcinoma without preoperative treatment revealed 24 (14.4%) to have intramural metastasis (IM) within the esophagus. Among the clinicopathologic factors, the length of the lesions (P < 0.01), lymph node metastasis (P < 0.001), and the depth of the invasion of the tumor (P < 0.0001) were found to be statistically significant different factors between the two groups of patients both with and without intramural metastasis. The survival curve for patients with IM was significantly lower than that for patients without IM (P < 0.0001). A univariate analysis revealed that the depth of invasion, lymph node metastasis, IM (P < 0.0001), and the length of the lesion (P < 0.001) all had a significant correlation with the prognosis. Moreover, in a multivariate analysis, the depth of the invasion (< 0.001), length of the lesion (0.001), and IM (0.049) were all determined to be significant prognostic factors. Therefore, IM is considered to be one of the independent significant prognostic factors for predicting a poor prognosis in esophageal cancer.

Adult↗
PubMed1994

Amino-acid alterations in the beta-tubulin gene of Neurospora crassa that confer resistance to carbendazim and diethofencarb.

We have previously shown that increased sensitivity to diethofencarb in the carbendazim(MBC)-resistant F914 strain of Neurospora crassa is caused by a single amino-acid change in beta-tubulin, 198Glu to Gly. Three diethofencarb-resistant mutants that are also resistant to MBC were isolated from strain F914. They contained single base-pair-substitution mutations in the beta-tubulin gene. The amino acid changes in beta-tubulin, Phe from 250Leu, Val from 165Ala, and Ala from 237Thr, were responsible for diethofencarb-resistance in the mutant strains FR511, FR513, and FR421, respectively. The amino acid at position 198 of beta-tubulin in these mutants was Gly, which is the same as in strain F914. beta-tubulin genes with 198Glu were constructed by site-directed mutagenesis. The altered beta-tubulin genes derived from FR511 and FR421 transformed the wild-type strain to resistance to MBC, indicating that 250Phe and 237Ala in beta-tubulin are responsible for resistance not only to diethofencarb but also to MBC.

Amino Acid Sequence↗
PubMed1994

Cloning of the blasticidin S deaminase gene (BSD) from Aspergillus terreus and its use as a selectable marker for Schizosaccharomyces pombe and Pyricularia oryzae.

Aspergillus terreus produces a unique enzyme, blasticidin S deaminase, which catalyzes the deamination of blasticidin S (BS), and in consequence confers high resistance to the antibiotic. A cDNA clone derived from the structural gene for BS deaminase (BSD) was isolated by transforming Escherichia coli with an Aspergillus cDNA expression library and directly selecting for the ability to grow in the presence of the antibiotic. The complete nucleotide sequence of BSD was determined and proved to contain an open reading frame of 393 bp, encoding a polypeptide of 130 amino acids. Comparison of its nucleotide sequence with that of bsr, the BS deaminase gene isolated from Bacillus cereus, indicated no homology and a large difference in codon usage. The activity of BSD expressed in E. coli was easily quantified by an assay based on spectrophotometric recording. The BSD gene was placed in a shuttle vector for Schizosaccharomyces pombe, downstream of the SV40 early region promoter, and this allowed direct selection with BS at high frequency, following transformation into the yeast. The BSD gene was also employed as a selectable marker for Pyricularia oryzae, which could not be transformed to BS resistance by bsr. These result promise that the BSD gene will be useful as a new dominant selectable marker for eukaryotes.

Amino Acid Sequence↗
PubMed1994

Microsoft Excel Program for creating attractive survival curves.

This paper describes the design of a Microsoft Excel Program which interactively creates attractive and outstanding survival curves. This program enables medical researchers to easily create quality presentation graphs of survival curves and obtain high quality slides and prints, which can be inserted in papers or used directly at medical meetings. Through the use of vertical bars, this program can display the exact points where censored cases occur on survival curves, making it possible to monitor censoring patterns between groups. Furthermore, this program can also create survival curves based on the proportional hazards model for specific patterns of covariate values, given estimated regression coefficients and baseline survival function. This program may be a most useful and effective tool in creating medical research papers containing survival analysis.

Age Factors↗
PubMed1994

Estimation of risk of major complications after hepatic resection.

To identify the risk factors predicting major postoperative complications from among preoperative and intraoperative variables, an extensive retrospective analysis of 209 patients who underwent hepatic resections was performed using multivariate logistic regression. The major complications were defined as liver failure, intractable ascites and pleural effusion, intraperitoneal infection, intra-abdominal hemorrhage requiring reoperation, major bile leakage, and gastrointestinal tract bleeding. First, detailed pre- and intraoperative data including medical history, laboratory data, portion and extent of hepatectomy, operative time, and amount of blood loss were univariately analyzed. Next, any significant variables were multivariately analyzed using the logistic regression method. Diabetes, increased intraoperative blood loss, resection of segment 8, and an increased serum blood urea nitrogen level were independent and significant variables predicting major postoperative complications. A higher level of serum cholesterol and a procedure involving a portion of left lateral segment were found to decrease the risk. Both more careful operative procedures and intensive management of DM and renal dysfunction in the perioperative period could result in a better quality of life after hepatic resection.

Blood Loss, Surgical↗
PubMed1994

Multiple comparison among groups of growth curves.

The problem of comparing a sequence of independent experiments divided into several groups with a control is discussed under the logistic growth-curve models. We propose a method for constructing multiple testing procedures using the closed testing procedures and the random-effect model for summarizing estimated values of parameters.

Animals↗
PubMed1994

Patient registration and treatment allocation in multicenter clinical trials using a FAX-OCR system.

This article describes the design and results of implementation of an automated patient registration and treatment allocation system (RETAS) used in multicenter clinical trials. RETAS was developed using a FAX-OCR system by which handwritten Japanese and English characters, as well as numericals and forms with check boxes, are sent from participating institutions by Fax, processed using an optical character reader, and then transmitted to a host computer at a statistical center. Based on the facsimile data, RETAS can automatically review eligibility, collect patient identification data and provide a randomized treatment allocation. RETAS permits uninterrupted, unattended operation at a statistical center, 24 hours a day, 7 days a week. Therefore, it drastically decreases the workload of personnel at the statistical center needed to support central telephone registration coverage. Consequently, staff members are free to focus on patient registration, treatment allocation, and follow-up of patients. The treatment allocation procedure in this system is based on Pocock and Simon's minimization method combined with Zelen's method for institution balancing. By this system it was possible to balance treatment numbers for each level of various prognostic factors over an entire trial and, at the same time, balance the allocation of treatments within an institution. The system currently supports the protocol of a clinical trial for Adjuvant Chemo-Endocrine Therapy for Breast Cancer in West Japan.

Computer Systems↗
PubMed1994

Role of lymph node dissection and splenectomy in node-positive gastric carcinoma.

BACKGROUND: In gastric carcinoma the relationship between survival of patients and degree of lymph node dissection is still controversial and there is no agreement about the efficacy of extended lymph node dissection and splenectomy. METHODS: Long-term results after surgery were statistically analyzed in 240 patients who underwent curative gastrectomy with lymph node dissection for node-positive gastric carcinoma from 1975 to 1990. RESULTS: The survival of patients was not significantly different among R1, R2, and R3 dissections, with the 10-year survival rate being 57%, 50%, and 44%, respectively. The survival rate was also not different between R2 and R3, even when the cases were stratified by the level of lymph node metastasis (N1, 66% vs 58%; N2, 28% vs 31%). The survival of patients was not significantly different between cases treated without splenectomy and those treated with splenectomy, with 10-year survival rates being 47% and 26%, respectively. The survival rate was also not different between non-splenectomy- and splenectomy-treated cases, even when the patients were compared in the same level of lymph node metastasis (N1, 60% vs 45%; N2, 23% vs 11%). CONCLUSIONS: In cases of curative gastrectomy the survival time of patients was not influenced by the level of lymph node dissection and splenectomy. For the treatment of node-positive gastric carcinoma (N1, N2) the long-term efficacy of R3 dissection and splenectomy seems limited.

Female↗
PubMed1994

Changes in regulating blood coagulation in hepatic resection with special references to soluble thrombomodulin and protein C.

The protein C anticoagulant pathway in hepatic resection was studied. The patients were divided into two groups--group 1 consisted of patients with a normal liver and group 2 consisted of patients with either hepatitic or a cirrhotic liver. Plasma protein C activity and soluble thrombomodulin were then sequentially measured during hepatectomy and in the early postoperative period. The protein C activity in group 1 decreased during hepatectomy and reached a low immediately after operation, and thereafter, recovered to near preoperative levels. However, the preoperative value in group 2 was lower than that in group 1 and the postoperative values were significantly lower than those in group 1 (p < 0.05). The level of soluble thrombomodulin in group 1 decreased during hepatectomy but later returned to preoperative levels. However, in group 2, the preoperative value was higher than that in group 1 and the postoperative values were greater than that of the preoperative values, while the values were significantly higher than those in group 1 (p < 0.05). During hepatectomy, hypercoagulability may contribute to the low levels of protein C and soluble thrombomodulin. The postoperative significant increase of soluble thrombomodulin may, thus, indicate the occurrence of endothelial injury in the remnant liver. The sequential measurements of both parameters can, therefore, be useful in detecting coagulopathy and endothelial injury in hepatic resection.

Aged↗
PubMed1994

Effect of nafamostat mesilate on coagulation and fibrinolysis in hepatic resection.

The effect of nafamostat mesilate on coagulation and fibrinolysis was investigated in a study of 22 patients with hepatocellular carcinoma who underwent a hepatic resection. The patients were divided into two groups: group 1, control (n = 11) and group 2, those with the intraoperative and postoperative use of nafamostat mesilate (0.2 to 0.4 milligram per kilogram per hour, n = 11). Nafamostat mesilate tended to suppress the coagulation expressed by thrombin-antithrombin III complex and fibrinopeptide A both during and immediately after operation. Moreover, nafamostat mesilate significantly suppressed the fibrinolysis expressed by euglobulin lysis activity both during and after operation. With regard to the initial stage of the fibrinolytic system, such as tissue-type plasminogen activator and plasminogen activator inhibitor-1, there was no difference between the groups. Therefore, the suppression of the euglobulin lysis activity may be caused by the inhibition of plasmin activity. There was no difference between the groups regarding operative blood loss. However, the rate of blood transfusion in group 2 was lower than that in group 1, and no fresh frozen plasma was required for the patients who lost over 2,000 milliliters of blood. Nafamostat mesilate can suppress euglobulin lysis activity both intraoperatively and postoperatively, and thus decrease the amount of blood transfusion needed. Therefore, at present, nafamostat mesilate seems to be one of the most useful agents for stabilizing the coagulant and fibrinolytic systems in hepatic resection.

Aged↗
PubMed1993

The association between transfusion and cancer-free survival after curative resection for hepatocellular carcinoma.

BACKGROUND: In cases of surgery for hepatocellular carcinoma (HCC), postoperative intrahepatic recurrence is the main obstacle to long-term survival of patients. The association between perioperative transfusion and recurrence-free survival was studied in 126 patients with HCC who underwent hepatic resection between 1985 and 1990 and in whom complete follow-up information was available until 1992. METHODS: Patients who received neither whole blood nor packed erythrocytes during hospitalization formed the no transfusion group (n = 72), and the remaining patients who were given either whole blood or packed erythrocytes during hospitalization constituted the transfusion group (n = 54). RESULTS: The 1-year, 3-year, and 5-year recurrence-free survival rates of the nontransfused versus transfused groups were 80.6% versus 74.1%, 50.9% versus 33.4%, and 37.1% versus 26.2%, respectively (P = 0.1590). After adjustment for other covariates, the serum albumin level and histological intrahepatic metastasis (im) remained as significant variables for recurrence-free survival. Although there was no association between the erythrocyte transfusion and the recurrence-free survival of the patients with serum albumin levels either more than 3.5 g/dl or less than or equal to 3.5 g/dl, the 1-year, 3-year, and 5-year recurrence-free survival rates of the nontransfused versus transfused groups of the patients with im-negative HCC were 92.2% versus 80.0%, 62.6% versus 36.3%, and 47.4% versus 27.1%, respectively (P = 0.0254). CONCLUSIONS: The association between erythrocyte transfusion and the recurrence-free survival was recognized only in patients with im-negative HCC.

Adult↗
PubMed1993

The significance of methicillin-resistant Staphylococcus aureus infection in general surgery: a multivariate analysis of risk factors and preventive approaches.

To investigate the characteristics, risk factors, and prevention of methicillin-resistant Staphylococcus aureus (MRSA), a total of 3,627 patients were studied. Among these, 1,336 patients with various infections were used in a risk factor analysis of MRSA to determine the relationship between the use of antibiotics and the incidence of MRSA. Only 3.0% of infections were attributed to MRSA, the esophagus and colorectal region being highly involved, as anastomotic or pelvic abscesses, while the lung had a lower incidence. Almost half the patients with MRSA infections (47.6%) had concomitant infection. A univariate analysis revealed the following significant factors: The coexistence of gastrointestinal or metastatic malignancy, sepsis, tracheostomy, and the prior use of antibiotics such as the beta-lactam compounds or aminoglycosides. A multivariate analysis showed that gastrointestinal malignancy, sepsis, and the prior use of aminoglycosides, tetracycline, macrolides, and carbapenems were independently significant factors. To promote the education of doctors and nurses, regular in-service meetings on MRSA were held in the ward. Moreover, preventive approaches such as patient isolation, strategically placed hand washing equipment, and the use of disposable gloves and contaminated waste bags, have been initiated, and the incidence of MRSA has decreased significantly since then. Thus, to control MRSA, the following steps should be taken: (1) constant and careful surveillance, (2) regular risk factor analyses, (3) the optimal administration of antibiotics, and (4) the education of all hospital staff.

Cross Infection↗
PubMed1992

A visual field quantification system for the Goldmann Perimeter.

We have developed a visual field quantification system that can accurately quantify the measurement results by the Goldmann Perimeter (GP). This system calculates the plural indexes introduced in published papers. In recent years, several isopter quantification methods have been proposed. In these methods, the isopters are digitized and the data are input into a computer, after which a computer program evaluates the changes in the isopters quantitatively. However, each program is only able to evaluate private indexes. We have developed a system that quantifies data using multiple methods. This system used five methods that have been introduced in published papers. With this system, a physician can analyze GP data with multiple methods and can diagnose diseases accurately. We have already input about 2500 GP recording papers into the computer by this system. We then calculated the plural indexes, and visualized the temporal changes in the perimetry.

Humans↗
PubMed1992

The effect of a multiple literature database search--a numerical evaluation in the domain of Japanese life science.

In literature database searching, we show that it is necessary to use plural databases for a more improved search. We also compare the results of a single database search with that of multiple database search in the domain of Japanese life sciences. We searched the MEDLINE and EMBASE using the same search terms. There were some differences in the results, owing to differences in the journals and recording methods. We herein show some of the differences in the journals contained in both databases. Furthermore, we show the differences in the number of papers derived from the same journal. Next, as an example of a practical search, we selected some universities in Japan, searched both databases regarding papers published from these universities and then merged the results by hand. According to our results, only 63% of all papers were common to both databases.

Biological Science Disciplines↗
PubMed1991

Markers of adverse drug reactions in medication histories. An analysis of inhaled steroid utilization.

Prescription sequence analysis is based on the observation that a subset of adverse drug reactions are themselves indications for the prescription of another drug. We propose an approach to the analysis of clustering of prescriptions in medication histories that contain records of a presumed side-effect-causing drug A and a side-effect-alleviating drug B. This set of histories with records of both A and B is analysed in a logistic regression model that considers the start of B against exposure and non-exposure of A, stratified on the level of the individual histories. A correction is presented for the periods of B use, during which a new start of B cannot occur. Prescription sequence analysis is demonstrated with a set of histories of use of inhaled steroids (A) and topical oral anticandida drugs (B). A can cause oral candidiasis, B is therapy for this condition. An odds ratio of 1.43 was found for the association of A use and the initiation of therapy with B.

Administration, Inhalation↗
PubMed1991

Clinical features of the differentiated and undifferentiated types of advanced gastric carcinoma: univariate and multivariate analyses.

This study was done to define clinical features for the different pathological types of advanced gastric carcinoma. One thousand one hundred three patients were identified and classified into two groups: 479 patients (43.4%) had a differentiated adenocarcinoma and 624 patients (56.6%) had an undifferentiated adenocarcinoma. Patients with the undifferentiated type were more likely to have large invasive tumors and a higher incidence of peritoneal dissemination. Conversely, the patients with the differentiated type were more likely to have a liver metastasis. Multivariate analysis, using Cox' proportional hazard model adjusted for sex, age, and other factors, suggested that tumor size was one of the seven most independent prognostic factors in patients with the undifferentiated type (relative risk = 1.01), but this parameter lost prognostic value in patients with the differentiated type. With regard to correlation between survival time and tumor size, the larger the tumor (over 10 cm), the shorter the survival time of patients with the undifferentiated type, as compared to findings in patients with the differentiated type (P less than 0.01). Thus, differences in clinical characteristics, including characteristics in the individual patients, extent of tumor, distant metastasis, prognostic factors, and prognosis correlate with the histopathological type of gastric carcinoma.

Adenocarcinoma↗
PubMed1991

Micro-mainframe-like personal clinical research system.

We constructed a micro-mainframe-link clinical research system for personal use (Personal Clinical Research System). This system was developed with both a mainframe computer and a personal computer (PC). The prepared programs included a database manager (on the mainframe computer), a user interface program (on the PC), and a communication control program that connected the mainframe computer with the PC. The database on the mainframe computer was constructed by two methods. The first method was to transmit data from the PC to the mainframe computer. The second method was to extract data from the patient information database. Using this system, a physician is able to construct a personal research database that contains interesting data for the physician. In addition, the physician is able to accumulate data on a special field using this system. A discharge summary system is now in operation as an example of this system.

Computers, Mainframe↗