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Biomedical subjects

Masaki Tamura

Publications and source records attributed to Masaki Tamura.

12 recordsLinked to original sources
PubMed2006

Adult moyamoya disease in the asymptomatic Japanese population.

Moyamoya disease (MMD) is a spontaneous occlusive disease of the Willis circle. This study evaluated the presence of the radiological hallmarks of adult MMD on a "brain check-up" (BC) using MRI and MR angiography, in Japan. BC was offered to 11,402 healthy subjects (7570 men and 3832 women) between January 1997 and November 2003. The mean age of all subjects was 53.2 years (SD 11.1); the mean age of men was 53.2 years (SD 10.9) and women 53.2 years (SD 11.5). MMD was diagnosed according to the criteria of the Research Committee on Spontaneous Occlusion of the Circle of Willis in Japan. Eight subjects (4 men and 4 women) were diagnosed as probable MMD without neurological deficits. Thus, the percentage of subjects with asymptomatic MMD on BC was 0.07% for the total group, 0.05% in men and 0.10% in women. The female to male ratio was 3.3:1. The mean age of the MMD patients was 54.0 years (SD 12.0); men 54.8 years (SD 12.8) and women 53.3 years (SD 13.9). Estimates of the prevalence of MMD in the Japanese population were calculated as 50.7 per 100,000 people; 28.9 in men and 94.3 in women. Five patients had a family history of definite MMD and seven had a family history of subarachnoid or intracerebral hemorrhage. MRI and angiography showed stenosis of the bilateral internal carotid arteries (ICA) in five patients and a unilateral ICA in three. Moyamoya vessels were confirmed on cerebral angiography. Our standard BC protocol is limited for the detection of moyamoya vessels in the initial stages of MMD. The present study suggests that the radiological features of MMD are asymptomatic in the early stages of the disease.

Adult↗
PubMed2006

Alteration of TH1 and TH2 cells by intracellular cytokine detection in patients with unexplained recurrent abortion before and after immunotherapy with the husband's mononuclear cells.

OBJECTIVE: To elucidate the possible mechanisms of immunotherapy for unexplained recurrent aborters using their husband's mononuclear cells. DESIGN: Prospective clinical study. SETTING: Institutional practice at the Outpatient Clinic for Infertility, Niigata University Medical Hospital. PATIENT(S): Fifty-two unexplained recurrent aborters were chosen as an experimental group. INTERVENTION(S): Each patient was injected with her husband's mononuclear cells as immunotherapy. Peripheral blood was obtained from the patients. MAIN OUTCOME MEASURE(S): The percentage of CD4-positive cells, TH1 cells, TH2 cells, and the TH1/TH2 ratio were analyzed in the patients before and after immunotherapy. The same analyses were performed in the successful and the unsuccessful group. RESULT(S): To date, 42 of the 52 patients have become newly pregnant. Of the 42, 34 patients have already delivered (successful group) and 3 are now pregnant, while the remaining 8 cases experienced repeated abortion (unsuccessful group). The percentage of TH2 cells significantly increased in the total patient population, while the TH1/TH2 ratio significantly decreased in the total patient population and in the successful group. CONCLUSION(S): These findings suggest that immunotherapy with the husband's mononuclear cells for unexplained recurrent abortion induces a dominant state of TH2 cells in the patients.

Abortion, Habitual↗
PubMed2006

Studies on the human leukocyte antigens in patients with polycystic ovary syndrome in a Japanese population--possible susceptibility of HLA-A11 and -DRB1*0403 to patient population with polycystic ovary syndrome.

PROBLEM: The objective of this study was to identify the human leukocyte antigen (HLA) alleles that confer susceptibility or resistance to polycystic ovary syndrome (PCOS) in the Japanese population. METHOD OF STUDY: HLA-A, -B and -C antigens were determined in 56 patients with PCOS using conventional serological method. HLA-DRB1 genotypes were determined using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 68 patients with PCOS. As a control population, 237 healthy individuals (males and females) were examined concerning HLA-A, -B and -C antigens, and 292 individuals were examined concerning HLA-DRB1 genotypes. The rate of possession of each antigen was compared between the two populations. RESULTS: The rate of possession of the HLA-A11 and HLA-DRB1*0403 in the patients with PCOS was significantly higher compared with that in the control group. The rate of possession of HLA-B39 in the patients with PCOS was significantly lower compared with that in the general population group. CONCLUSION: Human leukocyte antigen systems appear to be linked to PCOS.

Female↗
PubMed2006

Prophylactic therapy for patients with reproductive failure who were positive for anti-phospholipid antibodies.

PROBLEM: To elucidate the efficacy of the treatment using a Japanese-modified Chinese herbal medicine, Sairei-to, and low-dose aspirin with or without a corticosteroid hormone for the patients with adverse pregnancy histories positive for anti-phospholipid antibodies. METHOD OF STUDY: Fifteen cases positive for anti-phospholipid antibodies, who had experienced preterm delivery in which an extremely low birthweight infant (<1000 g) was born as a result of intrauterine growth restriction with or without severe preeclampsia, were treated with the medication according to the current protocol. Four cases with the same condition, who were treated with only low-dose aspirin, or without medication, were chosen as a control population. The pregnancy outcome was compared between the two groups. RESULTS: The rate of patients in whom the next pregnancy continued until the 36th week of gestation or later was significantly higher in treated patients (80.0%) compared with the control population (0%). CONCLUSIONS: In this series, we obtained case report data that Sairei-to may provide some benefit for patients with reproductive disorders positive for anti-phospholipid antibodies; however, randomized controlled trial evidence is needed before current treatment can be recommended.

Adult↗
PubMed2005

Molecular genetic studies on the compatibility of HLA class II alleles in patients with unexplained recurrent miscarriage in the Japanese population.

It is hypothesized that patients having unexplained recurrent miscarriage lack an appropriate immune reaction against their partner's antigens, which means possible compatibility of HLA antigens between the patient couples. The conclusion, however, has not yet been achieved, so the purpose was to determine whether significant compatibility of HLA class II exists between the couples. The HLA-DRB1 and -DQB1 genotypes were determined using PCR-RFLP method in 91 patient couples and in 72 normal couples. The number of patient couples with zero-allele mismatch was not significantly different compared with that of control couples regarding HLA-DRB1 genotype and phenotype, as well as regarding HLA-DQB1 genotype and phenotype. While the number of patient couples with zero- and one-allele mismatch was significantly higher compared with that in control as to HLA-DR and -DQ phenotype (P=0.029 by Chi-square test). In conclusion, it is suggested that the compatibility of HLA class II antigens between couples might be involved in the genesis of unexplained recurrent miscarriage.

Abortion, Habitual↗
PubMed2004

cis-Diamminedichloroplatinum-resistant cell lines derived from human epithelial ovarian carcinoma express increased susceptibility to angiogenesis inhibitor TNP-470.

OBJECTIVE: To elucidate the efficacy of TNP-470 on ovarian carcinomas by using cis-diamminedichloroplatinum (CDDP)-resistant cell lines. METHODS: The susceptibility of human ovarian carcinoma-derived cell lines and its resistant cell lines against cis-diamminedichloroplatinum (CDDP) to angiogenesis inhibitor, TNP-470, were analyzed using three human cultured cell lines derived from ovarian carcinoma (TYK, KF-92, and Nakajima) and each CDDP-resistant cell line (TYK-R, TYK-R', KF/ra, KF/rb, Nakajima-S1, and Nakajima-S2). RESULTS: TNP-470 revealed suppression of thymidine incorporation by all of the nine cell lines linearly dependent on the concentration of TNP-470. Significant suppression was not observed for either uridine or leucine incorporation by all nine cell lines. To elucidate the site of each cell line, in which TNP-470 revealed the antitumor effect, the incorporation of (3)H-TNP-470 by cultured cells or by DNA extracted from cultured cells was examined in the cell lines, and the ratio of (3)H-TNP-470 incorporation by DNA to (3)H-TNP-470 incorporation by cultured cells ranged from 2.3% to 4.4% in three parent cell lines. The ratio in the CDDP-resistant cell lines ranged from 11.0% to 46.7%. The ability of TNP-470 to inhibit neoplastic growth in vivo was evaluated using KF-92, KF/ra, KF/rb, Nakajima, Nakajima-S1, and Nakajima-S2. Concerning KF-92, KF/ra, and KF/rb, 30 mg/kg of TNP-470 significantly suppressed the tumorigenicity of KF-92, 10 and 30 mg/kg of TNP-470 suppressed the tumorigenicity of KF/ra, and 30 mg/kg of TNP-470 suppressed the tumorigenicity of KF/rb. Concerning Nakajima, Nakajima-S1, and Nakajima-S2, TNP-470 revealed no inhibitory effect on the tumorigenicity of Nakajima. Contrary, significant inhibition was observed when 30 mg/kg of TNP-470 was used to the CDDP-resistant cell lines Nakajima-S1 and Nakajima-S2. CONCLUSION: These results suggest that the clinical application of TNP-470 may be one of the possible treatments for the CDDP-resistant ovarian carcinomas.

Adenocarcinoma↗
PubMed2003

Results of immunotherapy for patients with unexplained secondary recurrent abortions.

Twenty-six unexplained secondary recurrent aborters underwent vaccinations by using their husband's mononuclear leukocytes according to the protocol adopted for primary recurrent aborters (group I). No mixed lymphocyte culture reaction-blocking antibodies (MLR-BAbs) detected by one-way MLR between spouses were observed in these patients prior to vaccination. In all 26 patients, MLR-BAbs appeared in their sera after vaccination with the husband's mononuclear leukocytes. Of 22 newly pregnant patients after vaccinations, pregnancy successfully continued in 20; thus, the success rate of the therapy was 90.9%. Pregnancy outcome was also analyzed in unexplained secondary recurrent aborters who revealed positive MLR-BAbs without immunotherapy (group II). In this group, in 9 of 12 patients (75.0%), the pregnancy continued successfully. The rate of continuation of pregnancy was not significantly different between groups I and II. Furthermore, the outcome of 11 pregnancies in 9 unexplained secondary recurrent aborters was analyzed in those who were negative for MLR-BAbs and had become pregnant without immunotherapy (group III). Pregnancy was successfully continued in only 2 cases (18.2%) in this group. The rate of successful pregnancy in experimental groups I and II was significantly higher compared with that in group III (P < 0.0005 and P < 0.01, respectively). Thus, immunotherapy using the husband's mononuclear leukocytes on unexplained secondary recurrent aborters with negative MLR-BAbs appears to be effective.

Abortion, Habitual↗
PubMed2003

Molecular genetic studies of HLA-DRB1 alleles in patients with unexplained recurrent abortion in the Japanese population.

BACKGROUND: Recently, evidence that HLA antigens are markers for recurrent spontaneous abortion has gained increased attention. Although the association between HLA class II antigens and patients with unexplained recurrent abortion was elucidated by a large population study in a Caucasian population, such analyses have been conducted in only a small Japanese population. The aim of the present study was to determine whether HLA-DR antigens are associated with patient populations with unexplained recurrent abortion in the Japanese population. METHODS: HLA-DRB1 genotypes were determined using a PCR-restriction fragment length polymorphism (PCR-RFLP) method in 93 patients with unexplained recurrent abortion (79 primary recurrent aborters and 14 secondary recurrent aborters) and in 115 normal fertile women. The rate of possession of each HLA-DRB1 genotype was compared among the three populations. RESULTS: The rate of possession of the HLA-DRB1*1502 in patients with secondary recurrent abortion was significantly higher (P < 0.01 after correction for multiple comparisons) compared with the control, fertile women. The rate of possession of HLA-DRB1*1502 was also higher in patients with primary recurrent abortions than in controls, but the difference was not statistically significant after correction. CONCLUSIONS: These findings suggest that HLA-DRB1*1502 might be a risk allele for unexplained recurrent abortion in the Japanese population.

Abortion, Habitual↗
PubMed2003

Associations between patients with endometriosis and HLA class II; the analysis of HLA-DQB1 and HLA-DPB1 genotypes.

BACKGROUND: Although the aetiology of endometriosis remains unclear, many immunological abnormalities involving changes in cell-mediated and humoral immunity may be associated with endometriosis. Several disorders are thought to be associated with particular HLA antigen types. This study examines the possible association between HLA-DQ and DP. METHODS: A total of 83 patients diagnosed with endometriosis following laparoscopic examination were typed for the HLA-DQB1 and DPB1 alleles using PCR-restriction fragment length polymorphism (RFLP). The HLA DQB1 and DPB1 allele frequencies in these patients and in 222 controls were compared. RESULTS: The prevalence of HLA-DQB1*0301 in the patient group was 16.3% (27/166 alleles), compared with 8.3% in the overall control group (37/444 alleles) and 7.7% in the females of the control group (18/234 alleles). Thus, the prevalence of the HLA-DQB1*0301 allele was significantly greater in patients with endometriosis, compared with the general controls [OR 2.13, 95% CI 1.25-3.64, P = 0.004 (chi(2) analysis), Corrected P-values; Pc = 0.049] and with the general female controls [OR 2.33, 95% CI 1.24-4.39, P = 0.008 (chi(2) analysis), Pc; NS]. There was no significant association in the frequencies of DPB1 alleles between the patients and controls. CONCLUSIONS: The HLA systems may be involved in the aetiology of endometriosis, although further study is needed.

Adult↗
PubMed2003

Effect of sairei-to combined with aspirin and prednisolone on four recurrent reproductive failure women who are positive for anti-phospholipid antibodies.

We treated four pregnancy cases positive for antiphospholipid antibodies (APLs) who had experienced recurrent second trimester fetal or neonatal losses using a Japanese modified Chinese herbal medicine, Sairei-to, low dose aspirin and adrenocorticosteroid hormone. The clinical courses of their new pregnancies in conjunction with the dynamic changes in their APL titers are described in this paper, and the possible efficacy of this treatment is discussed. The concept that autoimmune abnormalities, especially positive APLs, are generative factors for a range of reproductive failures, such as recurrent abortions, intrauterine growth retardation, intrauterine fetal death and preeclampsia, is now attracting a great deal of attention in the fields of reproductive immunology and perinatal medicine (Yasuda et al., 1995). The main mechanisms in the generation of reproductive failures are considered to be direct damage to chorionic villi by APLs during the period of placentation (Rote et al., 1998), as well as the formation of thrombi intervillous spaces (Arakawa et al., 1999). Considering these mechanisms of the reproductive failure generation by APLs, the application of immune suppressive therapy in combination with anti-coagulation therapy should be reconsidered as a treatment option. In this context, we treated four pregnancy cases positive for APLs who had experienced recurrent second trimester fetal or neonatal losses using a Japanese modified Chinese herbal medicine, Sairei-to, low dose aspirin and an adrenocorticosteroid hormone.

Abortion, Habitual↗