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Biomedical subjects

K Tajima

Publications and source records attributed to K Tajima.

At least 145 records · Page 8Linked to original sources
PubMed1999

Structural analyses of new tri- and tetrasaccharides produced from disaccharides by transglycosylation of purified Trichoderma viride beta-glucosidase.

A new beta-glucosidase was partially purified from Trichoderma viride cellulase. This beta-glucosidase catalyzed a transglycosylation reaction of cellobiose to give beta-D-Glc-(1-->6)-beta-D-Glc-(1-->4)-D-Glc (1, yield: 18.8%) and beta-D-Glc-(1-->6)-beta-D-Glc-(1-->6)-beta-D-Glc-(1-->4)-D-Glc (2, 3.7%), regioselectively. Furthermore, the enzyme regioselectively converted laminaribiose and gentiobiose into beta-D-Glc-(1-->6)-beta-D-Glc-(1-->3)-D-Glc (3, 15.3%) and beta-D-Glc-(1-->6)-beta-D-Glc-(1-->6)-D-Glc (4, 20.2%), respectively. The structures (1-4) of the products were determined by 1H and 13C NMR spectroscopies. This high regio- and stereoselectively of the beta-glucosidase could be applied for oligosaccharide synthesis.

Carbohydrate Sequence↗
PubMed1999

The presence of ancient human T-cell lymphotropic virus type I provirus DNA in an Andean mummy.

The worldwide geographic and ethnic clustering of patients with diseases related to human T-cell lymphotropic virus type I (HTLV-I) may be explained by the natural history of HTLV-I infection. The genetic characteristics of indigenous people in the Andes are similar to those of the Japanese, and HTLV-I is generally detected in both groups. To clarify the common origin of HTLV-I in Asia and the Andes, we analyzed HTLV-I provirus DNA from Andean mummies about 1,500 years old. Two of 104 mummy bone marrow specimens yielded a band of human beta-globin gene DNA 110 base pairs in length, and one of these two produced bands of HTLV-I-pX (open reading frame encoding p40x, p27x) and HTLV-I-LTR (long terminal repeat) gene DNA 159 base pairs and 157 base pairs in length, respectively. The nucleotide sequences of ancient HTLV-I-pX and HTLV-I-LTR clones isolated from mummy bone marrow were similar to those in contemporary Andeans and Japanese, although there was microheterogeneity in the sequences of some mummy DNA clones. This result provides evidence that HTLV-I was carried with ancient Mongoloids to the Andes before the Colonial era. Analysis of ancient HTLV-I sequences could be a useful tool for studying the history of human retroviral infection as well as human prehistoric migration.

Asian People↗
PubMed1999

Reproductive factors related to the risk of colorectal cancer by subsite: a case-control analysis.

The authors hypothesized that reproductive factors of colorectal cancer, which are probably mediated by endogenous hormones, would differ according to colonic subsite. Information on reproductive factors was obtained from 372 female colorectal cancer cases (113 proximal colon, 126 distal colon, 133 rectum) and 31,061 cancer-free controls at the Aichi Cancer Center Hospital, Japan, between 1988 and 1995. Multiple logistic analysis showed that late age at interview, family history of colorectal cancer among first-degree relatives, menstrual regularity, late age at menopause, late age at first pregnancy and late age at first full-term pregnancy were significantly associated with the risk of colorectal cancer. None of the risk factors were significantly dissociated between colon and rectal cancer. In polytomous logistic regression analysis, particularly noteworthy was the fact that the odds ratios for age at menarche (P-value for heterogeneity of odds ratios = 0.010), age at first pregnancy (P = 0.016) and age at first full-term pregnancy (P = 0.028) were significantly higher for distal than for proximal colon cancer. This study supports the hypotheses that there might be an association between reproductive factors and risk of colon cancer, and that the carcinogenesis of colon cancer, by subsite, might show aetiologic distinctions.

Case-Control Studies↗
PubMed1999

Alternating combination chemotherapy COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan, prednisone) in multiple myeloma: a multicenter phase II study (JCOG8906). Lymphoma Study Group of the Japan Clinical Oncology Group.

BACKGROUND: The main form of cytotoxic treatment for multiple myeloma (MM) is conventional dose chemotherapy at present. METHOD: Between November 1989 and December 1991, a multicenter phase II study of alternating conventional dose combination chemotherapy (CCT) with COP (cyclophosphamide, vincristine, prednisone) and MP (melphalan and prednisone) to evaluate its clinical usefulness for overt MM patients was conducted by the Lymphoma Study Group of the Japan Clinical Oncology Group (JCOG). RESULTS: Eighty-one previously untreated patients were enrolled in the study. For 69 eligible patients, the response rate was 50.7% [95% confidence interval (CI) 38.4-63.0%]. The median survival time was 38.5 (95% CI 32.0-44.4) months. The survival rate at 3 and 5 years was 50.7 and 27.3%, respectively. Grade 4 toxicity by the criteria of the World Health Organization consisted of anemia in eight patients, leucocytopenia in three, cardiac in one and hepatic in two, but there was no treatment-related death. CONCLUSION: The COP-MP regimen for overt MM is thought to be one of the effective CCTs according to the results of the present phase II study.

Adult↗
PubMed1999

Long-term follow-up results of adult patients with acute lymphocytic leukemia or lymphoblastic lymphoma treated with short-term, alternating non-cross-resistant chemotherapy: Japan Clinical Oncology Group Study 8702. Lymphoma Study Group.

BACKGROUND: Patients with acute lymphocytic leukemia (ALL) and those with lymphoblastic lymphoma (LBL) have overlapping clinical and immunophenotypic features and they have been treated with the same or very similar chemotherapy regimens. The goal of this multi-institutional phase II trial was to evaluate the therapeutic efficacy of a short-term, six-drug chemotherapy regimen for adult patients with untreated ALL or LBL. METHODS: Forty-six eligible patients, 41 with ALL and five with LBL, were treated with a short-term (planned total therapy duration; 36-38 weeks), simplified chemotherapy program; two courses of VEPA-L (vincristine, cyclophosphamide, prednisolone, doxorubicin, I-asparaginase plus intrathecal methotrexate and prednisolone) followed by four courses of M-VEPA (methotrexate plus VEPA), without the traditional maintenance therapy using daily 6-mercaptopurine and weekly methotrexate. RESULTS: Thirty-six (78%; 95% confidence interval 64-89%) of the 46 eligible patients achieved complete remission (CR). Among the 36 patients who achieved CR, four (11%) died of treatment complications, 26 (72%) relapsed and six (17%) remain alive in continuous CR. The median survival for all 46 eligible patients is 14 months and the median disease-free survival (DFS) for the 36 patients who achieved CR is 11 months. The estimate of the proportion of survival at 7 years of all 46 eligible patients is 15% at a median follow-up time of 96 months and that of DFS of the 36 patients achieving CR is 17% at a median follow-up time of 93 months. Subgroup analysis showed that an elevated serum C-reactive protein (CRP) level, age of 30 years or older, the presence of B-symptom and T-cell phenotype were likely to be associated with shortened survival. Although the observed CR rate (78%) is within the range of satisfaction, the long-term survival rate (15%) is inferior to those of published programs incorporating maintenance therapy. CONCLUSIONS: A fraction of adult patients with ALL or LBL are curable with a short-term, six-drug chemotherapy regimen. However, this simplified therapy of shorter duration cannot be recommended.

Adolescent↗
PubMed1999

Formation of 8-nitroguanine from 2'-deoxyguanosine by NO/O2 system.

We investigated the reaction of 2'-deoxyguanosine (dGuo) with NO/O2 gas mixture under physiological condition and detected 8-nitroguanine, which is known as a novel DNA lesion caused by peroxynitrite (ONOO-). The yield increased with increase in the ratio of O2 and pH. The reaction mechanism is discussed.

Deoxyguanosine↗
PubMed1999

Role of ovarian theca and granulosa cell interaction in hormone productionand cell growth during the bovine follicular maturation process.

We have investigated the possible role of theca and granulosa cell interaction in the control of the hormone-producing activity and growth of granulosa and theca cells during bovine ovarian follicular development, using a coculture system in which granulosa and theca cells were grown on opposite sides of a collagen membrane. When follicular cells were isolated from small follicles (3-5 mm), theca cells reduced estradiol, progesterone, and inhibin production by granulosa cells to 14 +/- 5%, 64 +/- 6%, and 27 +/- 4%, respectively, of the production by granulosa cells cultured alone. On the other hand, when the cells were isolated from large follicles (15-18 mm), theca cells increased these levels to 253 +/- 34%, 156 +/- 24%, and 287 +/- 45%, respectively. Theca cells did not affect the growth of granulosa cells. Androstenedione production by theca cells was augmented by granulosa cells to 861 +/- 190% (in small follicles) and 1298 +/- 414% (in large follicles), respectively. The growth of theca cells was also augmented by granulosa cells (small follicle, 210 +/- 43%, and large follicle, 194 +/- 24%, respectively). These results indicate that theca cells secrete factor(s) inhibiting the differentiation of immature while promoting that of matured granulosa cells; they also suggest that granulosa cells secrete factor(s) promoting both the differentiation and growth of theca cells throughout the follicular maturation process.

Androstenedione↗
PubMed1999

Tea polyphenol intake and changes in serum pepsinogen levels.

Following a phase I study, a phase II study was conducted to evaluate the effects of two different doses of tea polyphenols on serum pepsinogen levels. Subjects were patients aged 40 to 69 years who had undergone gastroscopy between 1995 and 1997 at Aichi Cancer Center Hospital, and had been found to have no disease requiring medication. Those with pepsinogen I < 70 ng/ml and pepsinogen I/II ratio < 6 were included in this study. Capsules containing 100 mg of tea polyphenols were administered for 1 year: 1 capsule per day for 101 patients (42 males and 59 females), and 6 capsules (equivalent to 10 cups) per day for 83 patients (30 males and 53 females). The enrollment of the 1 capsule group preceded that of the 6 capsule group, in which re-participation was allowed. Blood samples were obtained 1 year after participation from 86 participants of the 1 capsule group and 77 participants (43 new participants and 34 re-participants) of the 6 capsule group. The compliance in polyphenol capsule intake ranged from 11.4 to 105.7% (87.6% on average) of the scheduled amount for the 1 capsule group and 3.2 to 112.3% (77.8% on average) for the 6 capsule group. No serious polyphenol-related adverse effects were reported. The difference in pepsinogen I between before and after 1 year intake of the polyphenol was 3.1 ng/ml for the 43 participants of the 6 capsule group, but 3.5 ng/ml for the 1 capsule group. The mean pepsinogen I/II ratio for the 43 participants increased from 2.37 by 0.08. This increase was not larger than that for the 1 capsule group (from 2.61 by 0.11). Among 34 participants in both interventions, no significant increase in pepsinogen I and I/II ratio for the 6 capsule intervention was observed. This result suggests that additional polyphenol intake for 1 year in Japanese does not improve pepsinogen levels, which are considered to reflect stomach atrophy, a high-risk condition for stomach cancer.

Adult↗
PubMed1999

Comparative case-referent study of risk factors among hormone-related female cancers in Japan.

To assess the impact of reproductive and anthropometric factors as a risk indicator for female cancers in hormone-related organs, i.e., the breast, endometrium and ovary, we conducted a comparative case-referent study using data from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. The case group consisted of 1,465, 133 and 99 women who had first been diagnosed as having breast, endometrial and ovarian cancer, respectively. The referents were 25,488 female first-visit outpatients who had not previously been diagnosed with any type of cancer. The odds ratios (ORs) and their 95% confidence intervals (95%CI) were estimated using an unconditional logistic regression model. An inverse association with experience of delivery and a positive association with body mass index (BMI) and with change of BMI after 20 years of age, were observed consistently for all three cancer sites. We observed similar risk and protective factors for breast and endometrial cancer, but the effect of reproduction and overweight condition (BMI> or =25) were more prominent in endometrial cancer. Although the present study failed to find site-specific risk factors for ovarian cancer, the results provided evidence that being overweight and/or weight gain in adult life is a common risk factor for all three cancer sites. The results obtained from this study suggested that avoidance of weight gain may reduce the risk of female hormone-related cancers.

Adult↗
PubMed1999

Protective effect of allium vegetables against both esophageal and stomach cancer: a simultaneous case-referent study of a high-epidemic area in Jiangsu Province, China.

To study the relation between allium vegetable intake and cancer of the esophagus (EC) and stomach (SC) in Yangzhong city, which is one of the highest-risk areas for these cancers in Jiangsu province, China, a simultaneous case-referent study was conducted using histopathologically confirmed cases (EC: n = 81, SC: n = 153) and population-based referents (n = 234). A questionnaire was used to collect information on the general status of subjects, their dietary habits, frequency intake of allium vegetables and other foods, tea consumption, smoking and alcohol drinking. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by a multiple logistic regression model. The results showed that frequent intake of allium vegetables (including garlic, onion, Welsh onion and Chinese chives), raw vegetables, tomatoes and snap beans, and tea consumption were inversely associated with the risk for EC and SC. In the highest consumption category (> or = 1 time/week) of garlic, onion, Welsh onion and Chinese chives, the adjusted ORs compared with the lowest category (< 1 time/month) were 0.30 (CI = 0.19-0.47), 0.25 (CI = 0.11-0.54), 0.15 (CI = 0.08-0.26), and 0.57 (CI = 0.23-1.42) for EC, and 0.31 (CI = 0.22-0.44), 0.17 (CI = 0.08-0.36), 0.22 (CI = 0.15-0.31) and 0.40 (CI = 0.17-0.94) for SC, respectively. The main results in the present study suggested that allium vegetables, like raw vegetables, may have an important protecting effect against not only stomach cancer, but also esophageal cancer.

Adult↗
PubMed1999

Stability after sagittal split ramus osteotomy without post-operative maxillomandibular fixation in the treatment of prognathic patients with asymmetric mandibles.

OBJECTIVE: To examine post-operative stability in prognathic patients with mandibular asymmetry who underwent sagittal split ramus osteotomy (SSRO) of the mandible and titanium screw fixation without post-operative maxillomandibular fixation (MMF). DESIGN: Skeletal and dental changes after surgery with and without post-operative MMF were compared between prognathic patients with symmetric and asymmetric mandibles. SETTING AND SAMPLE POPULATION: Second Department of Oral and Maxillofacial Surgery at Tokyo Medical and Dental University. Twenty prognathic patients were examined. EXPERIMENTAL VARIABLE: An appliance for repositioning the proximal segment was applied in all 20 patients. Ten patients with symmetric mandibles received post-operative MMF with stainless steel wires and intermaxillary rubber traction after the removal of MMF (Group I), while the other 10 patients with asymmetric mandibles underwent post-operative intermaxillary rubber traction only (Group II). OUTCOME MEASURE: Posteroanterior cephalograms were obtained pre-operatively; 2-3 days post-operatively; and 3, 6, and 12 months after surgery. Changes in the positions of the gonion points (Go) and upper and lower incisors (U-1 and L-1) were examined. RESULTS: In both groups, the Go tended to shift laterally as a consequence of the operation. Although the tendencies of the post-operative changes in the Go points of Groups II and I were different, statistical analyses revealed no significant differences between the two groups. At the last stage of the follow-up period, the absolute value of the change in L-1 tended to be larger in Group II than in Group I, but without any statistical significance. CONCLUSION: This study suggests that post-operative change in prognathic patients with asymmetric mandibles treated without post-operative MMF is comparable to that in patients with symmetric mandibles treated with post-operative MMF. Accordingly, post-operative MMF may be avoided, even in prognathic patients with asymmetric mandibles.

Adolescent↗
PubMed1999

Phase II study of combined administration of 5-fluorouracil, epirubicin and mitomycin-C by hepatic artery infusion in patients with liver metastases of gastric cancer.

This multicenter phase II study evaluated the efficacy of the FEM regimen (5-fluorouracil 333 mg/m(2) each week, epirubicin 30 mg/m(2) once every 4 weeks and mitomycin-C 2.7 mg/m(2) once every 2 weeks) administered by hepatic artery infusion (HAI) for unresectable hepatic metastases of gastric cancer. The response rates were 55.6% (complete response: 3, partial response: 32, no change: 21, progressive disease: 7/63) and the mean 50% survival was 10.5 months. Most responders died due to the progression of extrahepatic lesions. HAI of the FEM regimen induced a high response rate in patients with hepatic metastases of gastric cancer, and the prognosis-determining factor was the existence of extrahepatic lesions in many patients.

Aged↗
PubMed1999

Sexual behaviour of commercial sex workers and their clients in Cambodia. Japan-Cambodia Collaborating Research Group.

OBJECTIVE: This study surveyed the sexual behaviour of commercial sex workers and their clients in an attempt to identify factors of transmission of STDs (including HIV/AIDS) and to control their epidemics in Cambodia and South-East Asia. DESIGN: Cross-sectional study. SETTING: Trained questioners asked items of the questionnaires to each objective subject in December 1996. Data were analysed to show the descriptive status by risk group of each person. PARTICIPANTS: 200 direct commercial sex workers, 220 indirect commercial sex workers, and 211 clients in Phnom Penh. RESULTS: Prostitution was widely accepted by both young males and females, and this was an easy way for young girls to obtain money. Although commercial sex workers and clients were knowledgeable about prevention methods against STDs, they seldom used condoms. Some commercial sex workers had been infected with STDs many times, and many of them incompletely treated the diseases by themselves. Social support from governmental and non-governmental organisation was poor. CONCLUSIONS: It is very important to support both commercial sex workers in practicing preventive methods against STDs and also visiting physicians when they notice symptoms of STDs. It is strongly recommended that not only governmental but also non-governmental organisations should be more active in this area.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Comparative study of lifestyles of residents in high and low risk areas for gastric cancer in Jiangsu Province, China; with special reference to allium vegetables.

There is a low risk area for gastric cancer in Jiangsu Province, China, where people frequently consume raw allium vegetables. As a first step epidemiological study to clarify the factors involved in the low incidence of gastric cancer, we conducted a comparative study of the ecological factors in a high risk area (HRA), Yangzhong, and a low risk area (LRA), Pizhou, using a questionnaire. Subjects were selected from the general population according to age and sex, and comprised 414 residents of the HRA and 425 residents of the LRA. Ecological factors were compared for the two areas by Cochran-Mantel-Haenszel method, age-adjusted. Smoking and drinking habits were found to be more common in the LRA. On the other hand, allium vegetables were consumed in the LRA much more frequently, with high consumption of raw vegetables fruit, tomatoes, kidney beans and soybean products. People who consumed garlic en masse 3 times or more per week were 82% of men and 75% of women in the LRA, and 1% of men and women in the HRA. The results of the survey suggest that frequent consumption of allium vegetables, in addition to other anticancer foods, may be a factor in low mortality for gastric cancer.

Adult↗
PubMed1999

Effect of life styles on the risk of subsite-specific gastric cancer in those with and without family history.

To evaluate a combined effect of gastric cancer family history (GCFH) and selected living habits on the subsite-specific of gastric cancer, a hospital-based case-referent study was conducted in Tokai area of Japan. The study subjects were 850 newly diagnosed gastric cancer (GC) patients and 28,619 cancer-free first-visit outpatients. Odds ratios (ORs) of all subsites of GC in subjects with both GCFH and habitual smoking were significantly higher (OR = 4.22) compared with those with merely GCFH (OR = 1.81) or habitual smoking (OR = 2.83). When positive GCFH subjects frequently consumed raw vegetable, the risk of GC decreased in cardia (OR = 0.68), antrum (OR = 0.43) and all subsites (OR = 0.74). Our findings provided evidence that GCFH and habitual smoking increased the risk of GC with family history, while frequent intake of raw vegetable decreased the risk and it was modified by other environmental factors.

Adult↗