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Biomedical subjects

H Kuratsune

Publications and source records attributed to H Kuratsune.

At least 19 recordsLinked to original sources
PubMed2006

Mental fatigue-induced decrease in levels of several plasma amino acids.

To investigate the relation between plasma amino acid levels and mental fatigue, we measured the plasma concentrations of 20 amino acids in 9 healthy volunteers before and after a fatigue-inducing mental task session for 8 hr. As fatigue-inducing mental tasks, the subjects performed an advanced trail making test, a Japanese KANA pick up test, and a mirror drawing test. As a control, 8-hr relaxation session was performed in the same subjects at an interval of 4 weeks. Immediately after the fatigue session, the plasma levels of branched-chain amino acids, tyrosine, cysteine, methionine, lysine, and arginine were below those after a relaxation session. The values for other blood parameters including total protein, albumin, glucose, and total cholesterol did not show any differences between the 2 sessions. These results indicate that mental fatigue may be characterized by a decrease in the plasma level of these amino acids.

Adult↗
PubMed2001

Effect of transforming growth factor-beta1 on the cell growth and Epstein-Barr virus reactivation in EBV-infected epithelial cell lines.

Transforming growth factor (TGF)-beta1 is a multifunctional cytokine that plays important roles in regulating cell growth and differentiation in many biological systems. In this study, we found that gastric tissue-derived Epstein-Barr virus (EBV)-infected epithelial cell lines GT38 and GT39 had resistance to TGF-beta1-mediated growth inhibition and apoptosis compared to a TGF-beta1-susceptible gastric carcinoma cell line HSC-39. However, TGF-beta1 partially induced EBV reactivation in GT38 and GT39 cells, as shown by the induction of EBV immediate-early BZLF1 RNA and its protein product ZEBRA and early antigen-D. The expressions of TGF-beta receptor I and II were detected in GT38 and GT39 cells by Northern and Western blot analyses. Both cell lines spontaneously produced the TGF-beta1, which was sufficient for inhibiting cell growth of HSC-39 cells. Taken together, these data suggest that TGF-beta1 may be a key factor for EBV reactivation and selective growth of EBV-infected epithelial cells in vivo.

Activin Receptors, Type I↗
PubMed2001

Anti-prothrombin antibodies combined with lupus anti-coagulant activity is an essential risk factor for venous thromboembolism in patients with systemic lupus erythematosus.

Anti-prothrombin antibodies (anti-prothrombin) and anti-beta2-glycoprotein I antibodies (anti-beta2-GP I) are the most common and characterized anti-phospholipid antibodies (aPL) detected using specific enzyme-linked immunosorbent assay (ELISA) systems. Recently, lupus anti-coagulant (LA) activity detected by a phospholipid-dependent coagulation assay was reported to be associated with anti-prothrombin and/or anti-beta2-GP I. Here we show that the co-existence of IgG anti-prothrombin and LA activity might be an essential risk factor for venous thromboembolism (VTE) in patients with systemic lupus erythematosus (SLE). We examined not only the levels of antibodies to prothrombin and anti-beta2-GP I (both IgG and IgM isotypes) using an ELISA system, but also LA activity detected using both diluted Russell's viper venom time (dRVVT) and STACLOT LA test in 124 patients with SLE. The SLE patients were divided into four groups according to the results of ELISA and LA assay results for each aPL: group A, ELISA+ and LA+ group B, ELISA+ and LA-; group C, ELISA- and LA+ group D, ELISA- and LA-. Regarding IgG anti-prothrombin, the prevalence of VTE was significantly higher in group A (16/35 cases, 45.7%, P < 0.001, Fisher's exact probability test) than in the other groups (B, 2/30, 6.7%; C, 1/22, 4.5%; D, 1/37, 2.7%). With respect to IgM anti-prothrombin and IgG or IgM anti-beta2-GP I, the prevalence of VTE was higher in both groups A and C than in group D, but no statistical difference in prevalence was found between groups A and C. Multivariate logistic regression analysis of risk factors for VTE confirmed that the co-existence of IgG anti-prothrombin and LA activity was the only significant risk factor for VTE (odds ratio, 19.13; 95% confidence intervals, 4.74-77.18).

Adolescent↗
PubMed2001

The elevation of natural killer cell activity induced by laughter in a crossover designed study.

The elevation of natural killer cell activity (NKCA) by laughter was not confirmed due to incomplete methodology of previous studies although positive emotion is believed to be favorable for health. To verify NKCA elevation by laughter in a crossover design, we measured NKCA before and after watching films, presenting 75-min comic film and non-emotional control film at different days to the same 21 healthy male subjects. Electromyogram of left major zygomatic muscle was obtained during the films to quantify the magnitude of laughter as an index of emotional expression. As indices of emotional experience, the self-rated pleasantness of the comic film and mood state before and after film were measured using visual analogue scale and Profiles of Mood State (POMS), respectively. The comic film significantly elevated NKCA (26.5-29.4%, p<0.05), whereas the control film did not (27.1-24.8%, not significant). This is the first study to demonstrate NKCA elevation by laughter in a crossover designed study. To examine the contribution of experiential and expressive aspects of laughter to NKCA elevation, correlation of NKCA elevation with the self-rated pleasantness, mood scores before and after comic film and the magnitude of laughter was statistically tested. We found that NKCA elevation was negatively correlated with the scores of negative mood scales of POMS while NKCA elevation had no significant correlation with self-rated pleasantness and the magnitude of laughter. Further group analysis revealed that high scores of depression and anger-hostility suppressed NKCA elevation by laughter. We also found that NKCA before and after comic film had tendency of correlation with self-rated pleasantness of the comic film while NKCA had no correlation with the magnitude of laughter. These findings suggest that NKCA elevation and NKCA before and after comic film seem to be related with the experiential aspects of laughter rather than with the expressive aspects.

Adolescent↗
PubMed2001

Association between the prevalence of antibodies to beta(2)-glycoprotein I, prothrombin, protein C, protein S, and annexin V in patients with systemic lupus erythematosus and thrombotic and thrombocytopenic complications.

BACKGROUND: Anti-phospholipid (aPL) antibodies (Abs) frequently found in the plasma of patients with systemic lupus erythematosus (SLE) have been associated with thrombotic complications. Our aim was to clarify the roles in thrombosis of aPL Abs that react with complexes of phospholipids and plasma proteins such as beta(2)-glycoprotein I (beta(2)-GPI), prothrombin, protein C, protein S, and annexin V. METHODS: We determined the prevalence of aPL Abs to various phospholipid-binding plasma proteins in SLE patients with arterial thrombosis (30 cases), venous thrombosis (19 cases), thrombocytopenia (14 cases), fetal loss (14 cases), and patients without complications (91 cases). The aPL Abs were measured by an ELISA system in which human plasma proteins (beta(2)-GPI, prothrombin, protein C, protein S, and annexin V) were immobilized on gamma-irradiated or plain polystyrene plates. RESULTS: All types of aPL Abs were frequently observed in the patients with SLE when gamma-irradiated polystyrene plates were used (51 of 168 cases positive for anti-beta(2)-GPI, 94 of 168 cases positive for anti-prothrombin, 36 of 168 cases positive for anti-protein C, 47 of 168 cases positive for anti-protein S, and 50 of 168 cases positive for anti-annexin V), whereas no Abs to these plasma proteins were detected when plain polystyrene plates were used. Multivariate analysis confirmed that both anti-beta(2)-GPI and anti-prothrombin Abs were significant risk factors for arterial thrombosis [odds ratios (ORs), 8.8 and 14.5, respectively; 95% confidence intervals (CIs), 3.2-25 and 1.8-116, respectively] but not for venous thrombosis. The presence of anti-protein S Abs was a significant risk factor for venous thrombosis (OR, 30.4; CI, 3.3-281) but not for arterial thrombosis. The only significant risk factor for fetal loss was the presence of anti-annexin V Abs (OR, 5.9; CI, 1.4-14.8). CONCLUSIONS: Patients with SLE frequently have some aPL Abs to beta(2)-GPI, prothrombin, protein C, protein S, and annexin V. Thrombotic complications in SLE may depend on the antigenic specificities of these Abs, alone or in combination.

Adolescent↗
PubMed1999

Borna disease virus infection in two family clusters of patients with chronic fatigue syndrome.

A high rate of Borna disease virus (BDV) infection has been demonstrated in patients with chronic fatigue syndrome (CFS). Herein, we focused on BDV infection in two family clusters of patients with CFS: a father, mother, two sons and one daughter (family #1); and a father, mother, two daughters and one son (family #2). All members, except for the elder son in family #1 and the father and son in family #2, were diagnosed with CFS. The results supported that all the family members with CFS were infected with BDV, as evidenced by the presence of antibodies to viral p40, p24 and/or gp18 and BDV p24 RNA in peripheral blood mononuclear cells. The healthy members, except for the father of family #2 who was positive for antibody to p24, were all negative by both assays. Follow-up studies in family #1 continued to reveal BDV antibodies and BDV RNA, except in the mother, who lost the RNA upon slight recovery from the disease.

Amino Acid Sequence↗
PubMed1999

Platelet activation induced by combined effects of anticardiolipin and lupus anticoagulant IgG antibodies in patients with systemic lupus erythematosus--possible association with thrombotic and thrombocytopenic complications.

Antiphospholipid antibodies (aPL) are well known to be associated with arterial and venous thrombosis. In a series of 180 patients with systemic lupus erythematosus (SLE), the prevalence of arterial thrombosis was obviously higher in the patients who had both anticardiolipin antibodies (aCL) and lupus anticoagulant (LA) (17/35, 48.6%, p<0.05) (Table 1) than in the other patients bearing aCL or LA alone or neither of them (2/145, 1.4%). Since a substantial fraction of the former group of patients with arterial thrombosis also had thrombocytopenia (12/17, 70.6%), there was a possibility that aCL and LA might have enhanced platelet activation and aggregation. To test this possibility, we studied the in vitro effects of aCL and LA on the enhancement of platelet activation by flow cytometric analysis using anti-CD62P and anti-CD41 monoclonal antibodies directed against platelet activation-dependent granule-external membrane (PADGEM) protein and platelet glycoprotein IIb (GPIIb), respectively. Platelet activation defined by the surface expression of CD62P was not induced by aCL+ x LA+ plasma only, but was significantly augmented by aCL+ x LA+ plasma in combination with adenosine diphosphate (ADP) at a low concentration that had only a modest effect on platelet activation. In contrast, aCL+ x LA-, aCL- x LA+ and aCL- x LA- plasma samples were incapable of enhancing platelet activation in the presence or absence of ADP stimulation. In addition to plasma samples, the purified IgG from aCL+ x LA+ plasma (aCL+ x LA+-IgG) also yielded apparent enhancement of platelet activation induced by ADP. Furthermore, platelet activation was generated by the mixture of aCL+ x LA--IgG and aCL- x LA+-IgG fractions prepared from individual patients, but not by each fraction alone. These results suggest that aCL and LA may cooperate to promote platelet activation, and may be involved, at least partially, in the pathogenesis of arterial thrombosis and thrombocytopenia in patients with SLE.

Adolescent↗
PubMed1998

High prevalence of thrombocytopenia in SLE patients with a high level of anticardiolipin antibodies combined with lupus anticoagulant.

The relationship between thrombocytopenia and the level of anticardiolipin antibodies (aCL) and/or the existence of lupus anticoagulant (LA) ware studied in 146 patients with systemic lupus erythematosus (SLE). These patients were divided into six groups: A, those LA positive with a high level of aCL (>10 U/ml) (10 cases); B, those LA positive with a low level of aCL (3-10 U/ml) (15 cases); C, those LA positive but aCL negative (<3 U/ml) (12 cases); D, LA negatives with a high level of aCL (12 cases); E, LA negatives with a low level of aCL (16 cases); and F, aCL and LA double negatives (81 cases). The prevalence of thrombocytopenia (platelet count < or = 100 x 10(9)L) was by far the highest in group A (9/10 cases, 90.0%, P < 0.005, Fisher's exact probability test) as compared with group B (4/15 cases, 26.7%), group C (4/12 cases, 33.3%), group D (1/12 cases, 8.3%), group E (4/16 cases, 25.5%), and group F (9/81 cases, 11.1%). When the relationship between moderate thrombocytopenia and arterial or venous thrombosis was studied in these patients with SLE, thrombocytopenia was detected in 10 (83.3%, P < 0.005, Fisher's exact probability test) of 12 patients with arterial thrombosis; however, it was present in only 4 (23.5%) of 17 patients with venous thrombosis and in 14 (12.3%) of 114 patients without thrombosis. These findings suggest that a high aCL activity combined with LA positively reflects a high risk for both thrombocytopenia and arterial thrombosis.

Adolescent↗
PubMed1998

Dehydroepiandrosterone sulfate deficiency in chronic fatigue syndrome.

The chronic fatigue syndrome (CFS) is a condition of unknown etiology, characterized by a persistent debilitating fatigue, the muscle-related symptoms and the neuropsychiatric symptoms. Recently, it has been reported that the patients with CFS might have impaired activation of the hypothalamic-pituitary-adrenal axis, and suggested that a part of the patho-genesis of CFS might be associated with abnormalities of the endocrine system. Herein, we show that the majority of Japanese patients with CFS had a serum dehydroepiandrosterone sulfate (DHEA-S) deficiency. Serum DHEA-S is one of the most abundantly produced hormones which is secreted from the adrenal glands, and its physiological function is thought to be a precursor of sex steroids. DHEA-S has recently been shown to have physiological properties, such as neurosteroids, which are associated with such psychophysiological phenomena as memory, stress, anxiety, sleep and depression. Therefore, the deficiency of DHEA-S might be related to the neuropsychiatric symptoms in patients with CFS.

17-Hydroxycorticosteroids↗
PubMed1998

Low levels of serum acylcarnitine in chronic fatigue syndrome and chronic hepatitis type C, but not seen in other diseases.

Recently, we found a serum acylcarnitine (ACR) deficiency in Japanese patients with chronic fatigue syndrome (CFS). To clarify whether this ACR abnormality is a characteristic of CFS or not, we also studied the levels of serum carnitine in Swedish subjects. Both serum ACR and free carnitine (FCR) levels in normal healthy subjects were quite different between Japanese (n=131) and Swedish people (n=46) (p<0.001). However, it is confirmed that Swedish patients with CFS (n=57) also had serum ACR deficiency (p<0.001). When we studied the levels of serum ACR and FCR in Japanese patients with various kinds of diseases (CFS, hematological malignancies, chronic pancreatitis, hypertension, diabetes mellitus, chronic hepatitis type C, psychiatric diseases), a significant decrease in the levels of serum ACR was only found in patients with CFS and chronic hepatitis type C (p<0.001). Therefore, we concluded that ACR deficiency in serum might be a characteristic abnormality in only certain types of diseases.

Acute Disease↗
PubMed1998

[Association between antiphospholipid antibodies and arterial or venous thrombosis/thrombocytopenia].

The relationship between thrombotic or thrombocytopenic complications and the existence of anticardiolipin antibodies (aCL) and/or lupus anticoagulant (LA) was studied in 146 patients with systemic lupus erythematosus (SLE). The prevalence of arterial thrombosis was obviously higher in patients who had both aCL and LA than in patients with either aCL or LA alone or in those with neither. Since a substantial fraction of the former group of patients with arterial thrombosis also had thrombocytopenia, there is a possibility that aCL and LA might enhance platelet activation and aggregation. To test this hypothesis, we studied the in vitro effects of aCL and LA on the enhancement of platelet activation by flow cytometric analysis using anti-CD62P and anti-CD41 monoclonal antibodies directed against platelet activation-dependent granule-external membrane (PADGEM) protein and platelet glycoprotein IIb (GPIIb). The IgG fraction purified from aCL+.LA+ plasma apparently enhanced platelet activation induced by adenosine diphosphate (ADP) at a low concentration, but IgG fractions from aCL+.LA- or aCL-.LA+ plasma did not cause enhancement of platelet activation. These results suggest that aCL and LA may cooperate to promote platelet activation, and may be involved, at least partially, in the pathogenesis of arterial thrombosis in patients with SLE.

Adolescent↗
PubMed1997

Polyclonal B-cell lymphocytosis with features resembling hairy cell leukemia-Japanese variant.

Polyclonal B lymphocytosis was found in four patients having clinical and hematologic features resembling those of hairy cell leukemia (HCL). All four patients were women between 37 and 67 years of age. Three patients had splenomegaly. Lymphadenopthy was absent or slight. Persistent lymphocytosis was seen in all the patients, and anemia and/or thrombopenia was observed in three of the patients. Abnormal lymphocytes have long microvilli and prominent membranous ruffles on their surfaces. Bone marrow aspirates and biopsy specimens showed increased numbers of abnormal lymphocytes with round nuclei and abundant pale cytoplasm. Although these findings were similar to those of HCL, studies of Ig gene rearrangements and expression showed the polyclonal proliferation of B cells. We called this new disease hairy B-cell lymphoproliferative disorder (HBLD). All four patients exhibited a polyclonal increase in serum IgG. The morphology of the cells in HBLD was more similar to that of leukemia cells of a variant form of HCL (HCL-Japanese variant) than to typical HCL cells. The surface IgG+, CD5-, CD11c+, CD22+, CD24-, CD25- phenotype and the weak tartrate-resistant acid phosphatase activity in the cells were identical to those of HCL cells of the Japanese variant. Our findings suggest that the B cells in HBLD are the nonmalignant counterpart of leukemic B cells in HCL-Japanese variant.

Adult↗
PubMed1997

High uptake of [2-11C]acetyl-L-carnitine into the brain: a PET study.

The brain uptake of acetylcarnitine was investigated in rhesus monkeys using different position labeled acetyl-L-carnitine and related molecules with 11C by positron emission tomography. The uptake values of radio-labeled acetylcarnitine into the brain were quite different depending on the labeling positions of 11C. That is, the uptake values of L-[methyl-11C]carnitine and acetyl-L-[methyl-11C]carnitine were almost the same and extremely low, while the uptake of [1-11C]-acetyl-L-carnitine was slightly higher. The uptake value of [2-11C]acetyl-L-carnitine was by far the highest among the 11C-labeled acetyl-L-carnitine and L-carnitine. The uptake of [2-11C]acetyl-L-carnitine into the brain was suppressed by the intravenous administration of glucose. These results suggest that endogenous serum acetyl-L-carnitine has some roles on conveying an acetyl moiety into the brain especially under an energy crisis, and that an unknown metabolic pathway of [2-11C]acetyl moiety might be rather active in the brain.

Acetylcarnitine↗
PubMed1997

Synthesis of O-[11C]Acetyl CoA, O-[11C]Acetyl-L-carnitine, and L-[11C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey.

The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with 11C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1-11C]acetyl CoA and O-[2[11C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1-11C]acetyl-L-carnitine and O-[2-11C] acetyl-L-carnitine in 70-80% yield, based on [1-11C]acetate or [2-11C]acetate, respectively. By an N-methylation reaction with [11C]methyl iodide, L-[methyl-11C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl-11C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [11C]methyl iodide. Initial data of the kinetics of the different 11C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented.

Acetyl Coenzyme A↗
PubMed1997

Risk of arterial thrombosis in patients with anticardiolipin antibodies and lupus anticoagulant.

The relationship between arterial or venous thrombosis and the levels of anticardiolipin antibodies (aCL) and/or existence of lupus anticoagulant (LA) was studied. The 141 patients with systemic lupus erythematosus (SLE) were divided into four groups: aCL single positive (25 cases), LA single positive (11 cases), aCL and LA double positive (25 cases), aCL and LA double negative (80 cases). The prevalence of thrombosis was higher in aCL and LA double positive patients (21/25 cases, 84.0%, P <0.01) than that in aCL single positive patients (4/25 cases, 16.0%), LA single positive patients (1/11 cases, 9.1%) and double negative patients (3/80 cases, 3.8%). Furthermore, in these double positive patients, all patients (10/10 cases) with a high positive level of aCL (> 10 units/ml) had arterial thrombosis, whereas only 2/15 patients (13.3%) with a low positive level of aCL (3-10 units/ml) were affected. Venous thrombosis was frequently found in the low positive group (9/15 cases, 60.0%). On the contrary, none of 105 LA negative patients had arterial thrombosis and only seven (6.7%) had venous thrombosis. These findings indicate that a high aCL activity combined with a LA positive result might be a risk factor for arterial thrombosis.

Adolescent↗
PubMed1997

[Demonstration on Borna disease virus in patients with chronic fatigue syndrome].

Chronic fatigue syndrome (CFS), a recently named heterogeneous disorder, is an illness of unknown etiology. The association between CFS and several viral infection has been suggested. Here, we centered on the possible link between CFS and Borna disease virus (BDV) infection. BDV is a neurotropic, nonsegmented negative-strand (NNS) RNA virus. Recent epidemiological data have suggested that BDV may be closely associated with depression and schizophrenia in humans. In Japanese patients with CFS, the prevalence of BDV infection was 34% (30/89) and 12% (7/57) by immunoblotting and PCR analysis, respectively. Furthermore, anti-BDV antibodies and BDV RNA were detected in a family cluster with CFS. These results suggested that this virus contributes to or initiates CFS, although the single etiologic role of BDV is unlikely.

Adult↗