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Biomedical subjects

T Yamabe

Publications and source records attributed to T Yamabe.

At least 37 records · Page 2Linked to original sources
PubMed1996

Influence of serum follicle stimulating hormone to luteinizing hormone ratio during buserelin acetate-induced pituitary desensitization on ovarian response to exogenous gonadotrophins in an in-vitro fertilization and embryo transfer programme.

We investigated the effect of endogenous gonadotrophins during pituitary desensitization with gonadotrophin-releasing hormone agonist (GnRHa) on ovarian responsiveness or the outcome of in-vitro fertilization (IVF) and embryo transfer. The results of 67 women who participated in the IFV programme at Nagasaki University Hospital, Japan, were analysed retrospectively. All women received GnRHa from the third day of menstrual cycle, and ovarian stimulation with exogenous gonadotrophins was initiated when the serum oestradiol concentration decreased to < 30 pg/ml. The serum follicle stimulating hormone (FSH)/luteinizing hormone (LH) ratio, rather than serum FSH or LH concentrations during GnRHa-induced pituitary desensitization, showed a significant positive correlation with age and the total dose of exogenous gonadotrophins. The FSH/LH ratio also showed a significant negative correlation with oestradiol response and the number of retrieved oocytes, and was significantly lower in pregnant women compared with the non-pregnant group during pituitary desensitization. Our results indicate that, even under pituitary desensitization with GnRHa, the serum FSH/LH ratio influences individual ovarian responsiveness and the state of the intra-ovarian hormonal environment. Our results suggest that the FSH/LH ratio may be a useful clinical predictor of the ovarian response to exogenous gonadotrophins under pituitary desensitization.

Adult↗
PubMed1996

Major histocompatibility complex class I expression on neurons in subacute sclerosing panencephalitis and experimental subacute measles encephalitis.

Lack of major histocompatibility class I antigens on neurons has been implicated as a possible mechanism for viral persistence in the brain since these antigens are required for cytotoxic T-lymphocyte recognition of infected cells. In subacute sclerosing panencephalitis (SSPE), measles virus (MV) persists in neurons, resulting in a fatal chronic infection. MHC class I mRNA expression was examined in formalin-fixed brain tissue from 6 SSPE patients by in situ hybridization. In addition MHC class I protein expression in MV-infected neurons was examined in experimental Subacute Measles Encephalitis (SME) by double immunohistochemistry. MHC class I mRNA expression was found to be upregulated in SSPE tissues studied, and in 5 out of 6 cases the expression was definitively seen on neurons. The percentage of neurons expressing MHC class I mRNA ranged between 20 to 84% in infected areas. There was no correlation between the degree of infection and expression of MHC class I molecules on neurons. Importantly, the number of neurons co-expressing MHC class I and MV antigens was markedly low, varying between 2 to 8%. Similar results were obtained in SME where 20 to 30% of the neurons expressed MHC class I but <8% co-expressed MHC class I and MV antigens. Perivascular infiltrating cells in the infected regions in SME expressed IFNgamma immunoreactivity. The results suggest that MV may not be directly involved in the induction of MHC class I on neurons and that cytokines such as IFNgamma may play an important role. Furthermore, the paucity of neurons co-expressing MHC class I and MV antigens in SSPE and SME suggests that such cells are either rapidly cleared by cytotoxic T lymphocytes (CTL), or, alternatively, lack of co-expression of MHC class I on MV infected neurons favors MV persistence in these cells by escaping CTL recognition.

Adult↗
PubMed1996

Primary prevention of HTLV-I in Japan.

The ATL prevention program (AAP) in the Nagasaki Prefecture since 1987 consists of screening of pregnant women and asking the seropositives to refrain from breast-feeding. We screened approximately 90% of gravidas in the Prefecture and > 90% of the seropositive women agreed not to breast-feed. The maternal transmission rate dropped from approximately 20% to approximately 3%. PCR of cord bloods showed that 2.5% were PCR-positive. However, among formula-fed children, none of the cord-positives seroconverted, and none of the seropositives tested had been cord-positive. Breast-feeding for less than six months decreased the transmission rate significantly, but may have a higher transmission rate than the formula feeding.

Adolescent↗
PubMed1996

[Effect of prolonged intravenous ritodrine tocolysis on diurnal glucose profiles in pregnant women with normal carbohydrate tolerance].

Our purpose was to investigate an effect of prolonged intravenous ritodrine tocolysis on maternal carbohydrate metabolism in women with normal glucose tolerance. In patients with preterm labor, diurnal plasma glucose levels were measured both during the 24 hours after beginning the therapy (phase 1) and each day during over five days of continuous ritodrine tocolysis (phase 2). We also measured diurnal plasma glucose levels in normal pregnant women without any therapy (control group). In phase 1, in comparison with before therapy, a significant increase in the plasma glucose levels was observed with the highest level at 9 hours after starting ritodrine (146.4 +/- 31.6mg/dl). The higher plasma glucose levels persisted during phase 1. Although infusion rates were similar in both phases, maternal plasma glucose levels in phase 1 were significantly higher than in phase 2 (mean plasma glucose level, 128.1 +/- 21.3mg/dl vs. 92.7 +/- 11.6 mg/dl, p < 0.05; maximum plasma glucose level, 159.5 +/- 25.2mg/dl vs. 106.6 +/- 14.5mg/dl, p < 0.05). Diurnal glucose levels in phase 2 were similar to those in the control group. In phase 1, there seemed to be a dose-dependent relation between the ritodrine infusion rates and plasma glucose levels, but we did not find any relationship between them in phase 2. In conclusion, although hyperglycemia occurs during the initial phase of continuous ritodrine therapy (at least 24 hours), prolonged ritodrine infusion leads to normalization of the maternal plasma glucose levels.

Blood Glucose↗
PubMed1996

A comparison of the prevalence and risk factors of high blood pressure among Japanese living in Japan, Hawaii, and Los Angeles.

THE AUTHORS STUDIED THE PREVALENCE AND RISK FACTORS of hypertension in samples of 2053 Japanese ages 40 to 70 in Hiroshima, Hawaii, and Los Angeles. The prevalence of hypertension (systolic blood pressure greater than or equal to 140 mmHg, diastolic blood pressure greater than or equal to 90 mmHg, or receiving antihypertensive drug treatment) was higher in Hawaii and Los Angeles for both sexes and almost all ages than in Hiroshima. The age- and sex-adjusted prevalence of hypertension in Hawaii, Los Angeles, and Hiroshima was 42.6%, 37.2%, and 29.7%. Hypertension was associated with a significant elevation in serum glucose, insulin, triglyceride, and total cholesterol levels in the combined participant population of Hawaii, Los Angeles, and Hiroshima. Age- and sex-adjusted mean values of serum total cholesterol, triglyceride, and insulin were highest in Hawaii and lowest in Hiroshima. The mean body mass index and 2-hour serum glucose levels were greatest in Hawaii and equal in the two other cohorts. These results suggest that hyperinsulinemia and hyperlipidemia may explain the prevalence of hypertension in the research participants.

Adult↗
PubMed1995

Risk factors for restenosis after percutaneous transluminal coronary angioplasty: role of lipoprotein (a).

To evaluate serum levels of lipoprotein (a) (Lp[a]) as a predictor of restenosis after percutaneous transluminal coronary angioplasty (PTCA), we evaluated 71 patients who underwent elective single-vessel angioplasty. Patients were divided into two groups according to the presence (n = 24 [34%]; group R) or absence (n = 47 [66%]; group N) of restenosis. Serum insulin levels were similar before and after the glucose challenge test in both groups. The median level of serum Lp(a) was 34.9 mg/dl in group R compared with 19.4 mg/dl in group N (p < 0.01). The frequency of the apo E4 allele was 4 (17%) in group R and 4 (9%) in group N (p = NS). The incidence of restenosis was significantly higher in patients with Lp(a) levels > or = 30 mg/dl than in those with Lp(a) levels < 30 mg/dl (65% vs 26%; p < 0.01). Our results indicate that a serum Lp(a) level > or = 30 mg/dl is a risk factor for restenosis.

Aged↗
PubMed1995

Local injection of methotrexate dissolved in saline versus methotrexate suspensions for the conservative treatment of ectopic pregnancy.

To compare the local injection of methotrexate (MTX) dissolved in saline and MTX suspensions for the laparoscopic treatment of ectopic pregnancy in terms of success rate and postoperative tubal patency. A total of 26 patients with unruptured ectopic pregnancies were selected from among 60 women with ectopic pregnancies admitted to the Nagasaki University clinic. Of these patients, 12 were treated with MTX dissolved in saline solution (solution group) and 14 with MTX suspensions consisting of lipiodol (LPD) with phosphatidylcholine (PC) added as a dispersing stabilizer (suspension group). Except for one case treated under transvaginal guidance, all the patients were treated by laparoscopy. Persistent ectopic pregnancy was recognized in seven cases (58%) in the solution group but in only two cases (14%) in the suspension group. Moreover, rupture occurred in two cases in the solution group but in no case in the suspension group. A patent treated tube was found in seven of 10 cases in the saline group and in 10 of 12 cases in the suspension group. During the follow-up period of 6-31 months, five women in the saline group and three women in the suspension group had an intrauterine pregnancy. In this study, the local injection of MTX is considered to be a reasonable method for the treatment of unruptured ectopic pregnancy, and the MTX suspension seems to be more effective and useful than MTX solution.

Adolescent↗
PubMed1995

A new approach to methotrexate and lipiodol suspensions for ectopic pregnancy: preliminary in vitro and animal experiments.

OBJECTIVES: To measure and evaluate the in vitro release of MTX from suspensions of methotrexate (MTX) and lipiodol (LPD), and to investigate the MTX concentration and fertility rate using an animal model. METHODS: This study was divided into three components: a) An in vitro Release Study, b) Animal Study No. 1 (concentration of tissue and plasma levels), and c) Animal Study No. 2 (fertility rate after MTX suspension). RESULT: The releasing rate in vitro was more rapid with MTX-S (MTX dissolved in saline) than with either MTX-LPD (MTX dissolved in lipiodol) or MTX-LPD-PC (MTX suspended in lipiodol and phosphatidylcholin, i.e., MTX suspension). The tissue concentration tended to be higher with an MTX suspension than with MTX-S. There was no significant difference in the fertility rate or the nidation index among the 3 groups (Groups 1, 2, and 3). CONCLUSION: The injection of an MTX suspension is useful for increasing the tissue concentration and maintaining the long-term effectiveness of MTX, and this technique might offer a new approach in the treatment of ectopic pregnancy (EP) or in second-line therapy for persistent EP.

Animals↗
PubMed1995

Association between maternal antibodies to the external envelope glycoprotein and vertical transmission of human T-lymphotropic virus type I. Maternal anti-env antibodies correlate with protection in non-breast-fed children.

Vertical transmission of human T-lymphotropic virus type I (HTLV-I) depends primarily on breast-feeding; substitution of bottle-feeding has reduced the transmission rate from 20% in breast-fed children to 3% among bottle-fed. To determine the correlates of transmission for long breast-feeding (> or = 6 mo), short breast-feeding (< 6 mo), and bottle-feeding mothers, the antibody titers of transmitter (T) mothers and non-transmitter (nT) mothers were analyzed by using synthetic and recombinant epitopes representing the immunodominant epitopes of gag (Gag1a, r24), env (Env1/5, MTA1, RE3), and tax (Tax8/22-24) proteins. Seroreactivity to gag and tax epitopes was not significantly different except for anti-r24 antibody titer, which was significantly higher among T-mothers (geometric mean 134) when compared with nT-mothers (62) in the long-feeding group (P < 0.001). Profiles of antibody titers against env epitopes were different. Within the long-feeding group, Env1/5, MTA1, and RE3 titers were significantly higher among T-mothers (258, 1,476, and 738, respectively) when compared with nT-mothers (106, 279, and 320, respectively) (P < 0.01 for all three epitopes). In contrast, within the bottle-feeding group, antibody titers to Env1/5 (269) and RE3 (418) among nT-mothers were significantly higher than those among T-mothers (80 and 113, respectively) (P < 0.01). These data confirm that high-titered anti-HTLV-I antibodies in the long-feeding group correlate with milk-borne transmission of HTLV-I and, more importantly, imply that maternal anti-env antibodies may reduce the risk of non-milkborne infection.

Amino Acid Sequence↗
PubMed1995

Effect of cilazapril on vascular restenosis after percutaneous transluminal coronary angioplasty.

BACKGROUND: In experimental studies using cilazapril, the strongest inhibition of neointima formation was obtained when treatment was initiated 6 days before injury. The MERCATOR trial showed no reduction in restenosis with cilazapril given after percutaneous transluminal coronary angioplasty (PTCA). The purpose of this study is to determine whether previous administration of cilazapril could prevent restenosis. METHODS: A total of 167 patients were randomly and prospectively assigned to the cilazapril group or the control group. In the cilazapril group, 78 patients received a 2 mg dose of cilazparil daily, starting 7 days before PTCA and continuing for 6 months. Only 128 patients (cilazapril 56, control 72) completed the study because 39 dropped out. Coronary angiograms were evaluated by the quantitative coronary angiogram (QCA) system. RESULTS: There were no differences between the two groups of patients with regard to baseline clinical and angiographic characteristics. QCA analysis (cilazapril 66 lesions, control 101 lesions): the loss at follow-up in minimal lumen diameter was 0.36 +/- 0.57 mm in the cilazapril group and 0.57 +/- 0.75 mm in the control group (P < 0.05). Restenosis rate: in the cilazapril group, 16 of 56 patients (28.6%) had restenosis in contrast to 36 of 72 patients (50.0%) in the control group (P < 0.02). When vessel restenosis was evaluated, 16 of 63 vessels (25.4%) demonstrated restenosis in the cilazapril group, in contrast to 41 of 82 vessels (50.0%) in the control group (P < 0.01). CONCLUSIONS: Treatment using cilazapril 7 days before PTCA significantly reduced the rate of restenosis. These data suggest that previous administration of cilazapril might be important for preventing restenosis.

Aged↗
PubMed1994

Thiol-mediated redox regulation of lymphocyte proliferation. Possible involvement of adult T cell leukemia-derived factor and glutathione in transferrin receptor expression.

The proliferative response of PBMC to PHA, Con A, OKT3 mAb and IL-2-dependent proliferation of PHA-blasts was examined in a thiol-free environment (cultured in a L-cystine- and GSH-free medium). [3H]TdR incorporation assay and cell cycle analysis revealed that stimulated PBMC could not enter the S phase when deprived of these thiol compounds. In thiol-free cultures, an increase in intracellular free Ca2+ concentration and IL-2R alpha-chain/p 55 (Tac) induction was still observed, whereas transferrin receptor induction was markedly reduced, suggesting that the proliferative response of mitogenically stimulated PBMC was arrested in the late G1 phase in which transferrin receptor is induced. In GSH-depleted cultures, a similar reduction of the proliferative response of PBMC and PHA-blasts was observed when the concentration of L-cystine was lowered, in a dose-dependent manner. Each reduction or loss of proliferative response was partially restored by supplementation of 2-ME or adult T cell leukemia-derived factor (ADF)/human thioredoxin which is considered to be an endogenous dithiol-reducing factor. L-Cystine transport analysis showed that mitogenically stimulated PBMC and PHA blasts incorporated L-cystine, whereas resting PBMC did not. Furthermore, ADF as well as 2-ME exhibited an enhancing activity on the L-cystine transport in PHA blasts. Together with the fact that L-cystine transport is a limiting step in glutathione synthesis, these findings suggest that GSH and ADF might cooperate in the thiol-mediated redox regulation process and might also play key roles in cell cycle (late G1 to S) progression of activated lymphocytes.

Amino Acid Sequence↗
PubMed1994

HTLV-I proviral DNA in umbilical cord blood of babies born to carrier mothers.

Human T-lymphotropic virus type I (HTLV-I) in cord blood raises the possibility of intrauterine transmission as an alternative pathway to transmission via breast milk. However, none of 7 children with HTLV-I proviral DNA positive cord blood had seroconverted by 24-48 months. Contamination of cord blood by maternal blood was precluded on the basis of viral load and IgA concentration. Thus cord blood proviral DNA is not a hallmark of intrauterine infection. Moreover, none of the cord blood samples of 9 formula-fed children later confirmed to be infected was positive for HTLV-I, indicating that intrauterine infection is not a likely candidate as an alternative pathway.

Breast Feeding↗
PubMed1994

Extracellular human T-cell lymphotropic virus type I Tax protein induces cytokine production in adult human microglial cells.

Tropical spastic paraparesis (HAM/TSP) is caused by human T-cell lymphotropic virus type I (HTLV-I) infection. Although the virus infects T cells in vivo and is capable of infecting microglia in vitro, the inflammatory demyelination has not been linked to virus in central nervous system tissue. Thus, indirect mechanisms (e.g., cytokines) could be involved in demyelination and inflammation. The ability of HTLV-I Tax protein to induce tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-6 in primary adult human microglia and peripheral blood macrophages (PBMs) was examined by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction (RT-PCR). Tax (20 ng/ml) induced TNF-alpha in microglia (from undetectable or low basal levels to 215-1,075 pg/ml, mean 576 +/- 375 pg/ml, n = 4) and in PBMs (70-1,900, mean 646 +/- 844 pg/ml, n = 4). This induction was dose dependent, Tax specific, and maximal at 8 hours after stimulation. IL-6 levels in microglia increased from a basal level of 368 +/- 194 to 664 +/- 270 pg/ml 24 hours after Tax stimulation. In contrast, IL-1 beta levels were modestly induced (< or = 26 pg/ml). An increase in mRNA levels of the three cytokines was observed by semiquantitative RT-PCR (TNF-alpha = 28-fold; IL-6 = 5.6-fold; IL-1 beta = 3.6-fold). Thus, in HAM/TSP, extracellular Tax released from infiltrating T cells could induce cytokine release by microglia and contribute to demyelination and inflammation in the absence of detectable virus.

Adult↗
PubMed1994

Influence of intraballoon pressure on development of severe mitral regurgitation after percutaneous transvenous mitral commissurotomy.

To evaluate the influence of intra-balloon pressure on the development of severe mitral regurgitation (> or = grade 3+), we measured intraballoon pressure during percutaneous transvenous mitral commissurotomy (PTMC) in 62 patients using the Inoue balloon catheter. The peak intraballoon pressure was 2.29 +/- 0.55 kg/cm2. Severe mitral regurgitation as a result of leaflet tear occurred in 7 patients (11%). Patients were divided into two groups those with (n = 7) and those without (n = 55) severe mitral regurgitation. Intraballoon pressure had been significantly higher in those with vs. those without severe mitral regurgitation (2.76 +/- 0.31 kg/cm2 vs. 2.23 +/- 0.55 kg/cm2, P < 0.01). Multiple logistic regression analysis revealed that the occurrence of severe mitral regurgitation was related to only the peak intraballoon pressure. These data suggest that a high intraballoon pressure is a risk factor for severe mitral regurgitation as a result of leaflet tear.

Adult↗
PubMed1994

Influence of ovarian endometrioma on fertility.

OBJECTIVE: This study examines the influence of ovarian endometrioma on fertility. STUDY DESIGN: For 117 infertile women who were diagnosed as having endometriosis by laparoscopy and who underwent danazol therapy, we examined (1) the relationship between ovarian endometrioma and level of bead-phagocytotic macrophages in ascites and the interleukin-1 beta level, (2) the relationship between ovarian endometrioma and pregnancy rate during the 36 months after danazol therapy, and (3) the relationship between ovarian endometrioma and pregnancy rate, considering the severity of the lesion on the bilateral tubes and the pelvic peritoneum. RESULTS: (1) The levels of bead-phagocytotic macrophages in patients with or without ovarian endometrioma were 68% and 67%, respectively (not significant). Similarly, no significant difference was seen in the interleukin-1 beta positive rate between the two groups. (2) The pregnancy rates of the former group and the latter group were 36% and 43%, respectively (not significant). (3) The existence or absence of ovarian endometrioma made no significant difference in the pregnancy rate in a group of patients with no lesions in the bilateral tubes or in another group with no lesions and scattered endometriotic implants on the peritoneum. CONCLUSIONS: It seems unlikely that ovarian endometrioma itself significantly impedes fertility after danazol therapy.

Adult↗
PubMed1994

Cytokine-gene expression in measles-infected adult human glial cells.

The expression of interleukin (IL)-1 beta, IL-6 and tumor necrosis factor (TNF) alpha transcripts in cultured human glial cells was examined using reverse transcription followed by polymerase chain reaction (PCR) amplification and Southern blot quantitation. Microglial cultures derived from brain biopsy specimens from three different individuals expressed transcripts for the three cytokines under basal culture conditions. This expression was enhanced in response to measles virus (MV) infection (IL-1 beta, 2.2-8.8-fold; IL-6, 2.5-8.4-fold; TNF alpha, 2.2-3.2-fold). Neither IL-1 beta nor TNF alpha transcripts were detectable in undissociated brain tissue from two individuals, suggesting that the basal expression of these cytokines in culture may have been induced by tissue dissociation or by the culture conditions. Oligodendrocytes did not express cytokine transcripts under basal culture conditions, and IL-1 beta and IL-6 but not TNF alpha transcripts could be induced by MV. Similarly, meningeal fibroblasts expressed IL-1 beta and IL-6 but not TNF alpha in response to MV-infection, suggesting that the production of TNF alpha is more cell type-restricted than either IL-1 beta or IL-6. The results indicate that adult human microglia can participate in the inflammatory response to MV infection in the CNS by producing cytokines that contribute to inflammation and demyelination. In addition, besides their role in myelination, oligodendrocytes can potentially influence immunoreactivity in the CNS by producing IL-1 beta and IL-6.

Adolescent↗