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Biomedical subjects

Y Nagata

Publications and source records attributed to Y Nagata.

At least 163 records · Page 9Linked to original sources
PubMed1999

A case of sarcoidosis involving the tongue.

Sarcoidosis is a systemic granulomatous disorder which commonly affects the skin. Involvement of the tongue is rare; a review of the previous literature over the last 30 years revealed only six cases of sarcoidosis affecting the tongue. We studied a case of sarcoidosis involving the tongue in a 32-year-old Japanese woman with characteristic clinical and pathological findings. She visited our department with a complaint of a tongue lesion of which she had been aware for a month. A diagnosis of sarcoidosis was made for the lesion by clinical and pathological examinations. Oral involvement by sarcoidosis is rare, however this disorder should be considered as a possible cause of intraoral granulomatous lesions.

Adrenal Cortex Hormones↗
PubMed1999

Role of the cytomegalovirus (CMV)-antigenemia assay as a predictive and follow-up detection tool for CMV disease in AIDS patients.

Forty-two patients were evaluated to determine the value of the CMV antigenemia (CMV-Ag) test as a follow-up marker as well as a prediction marker of CMV disease. Twenty patients were positive for at least one positive CMV-Ag assay and 9 of them developed CMV retinitis. With the threshold value (10 positive cells), sensitivity was 56% and specificity was 94%. The CMV-Ag assay, with the threshold value, produced high specificity, positive predictive value and negative predictive value but relatively poor sensitivity. Eight patients experienced CMV disease relapse a total of 16 times. At relapse, 8 of the 16 times showed negative for CMV-Ag assay; 7 underwent systemic maintenance while 1 underwent local maintenance. It is inferred that the CMV-Ag test is a poor follow-up marker to detect the relapse of CMV disease, particularly in patients undergoing systemic maintenance.

AIDS-Related Opportunistic Infections↗
PubMed1999

The contribution of menopause to changes in body-fat distribution.

OBJECTIVE: To investigate whether menopause contributes to changes in body-fat distribution, irrespective of aging or obesity. METHODS: The subjects were 545 premenopausal (aged 16-55 years; mean +/- standard deviation, 37.7 +/- 9.1 years) and 219 postmenopausal (aged 45-65 years, 58.0 +/- 5.0 years) women. Baseline characteristics included age, body mass index (BMI), and menopausal status (premenopause or postmenopause). The ratio of trunk fat to leg fat (trunk-leg ratio) was estimated by dual-energy X-ray absorptiometry. The trunk-leg ratio and baseline characteristics were compared between the 2 groups. In all subjects (n = 764), possible correlations between the trunk-leg ratio and the baseline characteristics were determined using univariate and multivariate analysis. In postmenopausal women, the relationship of the trunk-leg ratio to YSM or age after adjusting for BMI was investigated. RESULTS: The trunk-leg ratio and BMI were significantly higher in postmenopausal women than in premenopausal women. In all subjects, age and BMI were positively correlated with the trunk-leg ratio (r = 0.445 and 0.587, respectively, p < 0.0001). Menopause was also positively correlated with the trunk-leg ratio on univariate regression analysis (standardized regression coefficient = 0.369, p < 0.0001). On multiple regression analysis, age, BMI, and menopause were independently correlated with the trunk-leg ratio (p < 0.05). In postmenopausal women, age and YSM were positively correlated with the trunk-leg ratio, independent of the BMI (p < 0.01). CONCLUSIONS: Menopause contributes to a change in body-fat distribution, irrespective of aging or obesity.

Abdomen↗
PubMed1999

Differences in umbilical cord serum lipid levels with mode of delivery.

OBJECTIVE: To investigate whether umbilical cord serum lipid levels differ with mode of delivery. DESIGN: Retrospective observation study. POPULATION: Two hundred and ninety mothers aged 29.1 years (SD 4.7) who had vaginal delivery, and 44 mothers aged 30.4 years (SD 4.7) who had elective caesarean section were enrolled. MAIN OUTCOME MEASURES: Maternal and umbilical cord blood were obtained immediately after delivery. Serum lipid levels including total cholesterol, high density lipoprotein cholesterol, saturated fatty acid, mono-unsaturated fatty acid and polyunsaturated fatty acid were measured. Obstetric variables and serum lipid levels were compared between the two groups. In each group the correlations of fetal serum lipid levels with maternal serum lipid levels were investigated. RESULTS: There were no significant differences in maternal age, neonatal weight, gestational duration, placental weight and neonatal gender distribution between the two groups. Only the two fetal serum lipid levels (including total cholesterol and non-high density lipoprotein cholesterol) showed a correlation with maternal fetal lipid levels with correlation coefficients > 0.3 in the caesarean section group. However, saturated fatty acid, mono-unsaturated fatty acid and total fatty acid levels in the non-high density lipoprotein low density lipoprotein, very low density lipoprotein, intermediate density lipoprotein and free fatty acid fraction in the umbilical cord serum were significantly higher in the vaginal delivery cases (P < 0.01). CONCLUSIONS: Umbilical cord serum levels of saturated and mono-unsaturated fatty acids increase during vaginal delivery.

Adolescent↗
PubMed1999

Two different types of dehalogenases, LinA and LinB, involved in gamma-hexachlorocyclohexane degradation in Sphingomonas paucimobilis UT26 are localized in the periplasmic space without molecular processing.

gamma-Hexachlorocyclohexane (gamma-HCH) is one of several highly chlorinated insecticides that cause serious environmental problems. The cellular proteins of a gamma-HCH-degrading bacterium, Sphingomonas paucimobilis UT26, were fractionated into periplasmic, cytosolic, and membrane fractions after osmotic shock. Most of two different types of dehalogenase, LinA (gamma-hexachlorocyclohexane dehydrochlorinase) and LinB (1,3,4,6-tetrachloro-1,4-cyclohexadiene halidohydrolase), that are involved in the early steps of gamma-HCH degradation in UT26 was detected in the periplasmic fraction and had not undertaken molecular processing. Furthermore, immunoelectron microscopy clearly showed that LinA and LinB are periplasmic proteins. LinA and LinB both lack a typical signal sequence for export, so they may be secreted into the periplasmic space via a hitherto unknown mechanism.

Bacterial Proteins↗
PubMed1999

Cloning and sequencing of a novel meta-cleavage dioxygenase gene whose product is involved in degradation of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis.

Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole source of carbon and energy. In a previous study, we showed that gamma-HCH is degraded to chlorohydroquinone (CHQ) and then to hydroquinone (HQ), although the rate of reaction from CHQ to HQ was slow (K. Miyauchi, S. K. Suh, Y. Nagata, and M. Takagi, J. Bacteriol. 180:1354-1359, 1998). In this study, we cloned and characterized a gene, designated linE, which is located upstream of linD and is directly involved in the degradation of CHQ. The LinE protein consists of 321 amino acids, and all of the amino acids which are reported to be essential for the activity of meta-cleavage dioxygenases are conserved in LinE. Escherichia coli overproducing LinE could convert both CHQ and HQ, producing gamma-hydroxymuconic semialdehyde and maleylacetate, respectively, with consumption of O(2) but could not convert catechol, which is one of the major substrates for meta-cleavage dioxygenases. LinE seems to be resistant to the acylchloride, which is the ring cleavage product of CHQ and which seems to react with water to be converted to maleylacetate. These results indicated that LinE is a novel type of meta-cleavage dioxygenase, designated (chloro)hydroquinone 1, 2-dioxygenase, which cleaves aromatic rings with two hydroxyl groups at para positions preferably. This study represents a direct demonstration of a new type of ring cleavage pathway for aromatic compounds, the hydroquinone pathway.

Amino Acid Sequence↗
PubMed1999

Possible involvement of IL-12 expression by Epstein-Barr virus in Sjögren syndrome.

AIM: To determine the correlation between interleukin 12 (IL-12) expression and Epstein-Barr virus (EBV) in Sjögren syndrome. METHODS: Indirect immunohistochemical technique, enzyme linked immunosorbent assay (ELISA), and immunoblot analysis were used to investigate IL-12 expression by EBV activation, using 13 surgical specimens and four B cell lines. RESULTS: Marked expression of IL-12 was found in the epithelial cells and the infiltrating B cells of salivary gland tissues from patients with Sjögren syndrome (six of 10 cases), but not in those from normal individuals (none of three cases). A striking topographic correlation between IL-12 and EBV was found. In addition, levels of IL-12 production by B cell lines were clearly enhanced by EBV activation in vitro. CONCLUSIONS: IL-12 expression closely reflects the intracellular event of EBV activation in Sjögren syndrome, and may contribute to the T helper cell type 1 (Th1) cytokine overexpression seen in this disease.

Adult↗
PubMed1999

A splicing mutation of the tyrosinase gene causes yellow oculocutaneous albinism in a Japanese patient with a pigmented phenotype.

BACKGROUND: Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair. OBJECTIVE: We studied a Japanese girl who had brown hair, a lighter skin color than her unaffected family and brown eyes at 9 months of age. METHODS: We performed direct sequencing analyses of the tyrosinase gene in her genomic DNA. RESULTS: The patient was a compound heterozygote for the +DeltaC310 mutation (known to result in absent melanogenic activity) and a second t-->a transition at the 3' end of intron 2. CONCLUSION: The t-->a transition has previously been reported as a splicing mutation in other Caucasian patients with a typical yellow OCA phenotype. However, this patient showed much more pigmentation than that reported in Caucasians. Therefore, we estimate that the mild phenotype results from her genetic pigment background.

Albinism, Oculocutaneous↗
PubMed1999

Effects of a water-soluble prodrug of vitamin E on doxorubicin-induced toxicity in mice.

Effects of the administration of a water-soluble prodrug of vitamin E on doxorubicine (DXR)-induced lethal and oxidative toxicity in mice were studied. The prodrug used was d-alpha-tocopheryl N,N-dimethylaminoacetate hydrochloride (TDMA). It was intravenously administered to animals 2 h prior to an intraperitoneal administration of DXR (15 mg/kg). The single preadministration of the prodrug (10-50 mg/kg equivalent for d-alpha-tocopherol) delayed the DXR-induced death and the ameliorative effect was TDMA-dose dependent. The extent of total lipid peroxidation of the heart and liver was assessed by 2-thiobarbituric acid reactant substance levels. DXR significantly accelerated lipid peroxidation in the liver but not in the heart. The elevation of liver lipid peroxide was significantly suppressed to a normal range by a single preadministration of TDMA (50 mg/kg equivalent for d-alpha-tocopherol). TDMA did not significantly affect the antitumor activity of DXR in mice inoculated with L1210 leukemia cells.

Animals↗
PubMed1999

Technetium-99m complexes with steroid-2-aminooxyethyliminodiacetic acid conjugates.

Conjugates of 2-aminooxyethyliminodiacetic acid with estrone, testosterone, epiandrosterone, 17-alpha-hydroxy-progesterone and progesterone were synthesized and their complexes with Tc-99m were successfully prepared in good yields, which indicated the agent to be promising for metal-labeling of biomolecules and related substances containing one or more carbonyl groups. The biodistribution and scintigraphic studies in mice bearing Ehrlich tumor and mammary tumor showed that the radioactivity accumulated considerably in the tumor tissues, but the tumor images were somewhat obscured.

Animals↗
PubMed1999

Bone marrow-derived dendritic cells incorporate and process hydrophobized polysaccharide/oncoprotein complex as antigen presenting cells.

We have previously shown that a novel hydrophobized polysaccharide/oncoprotein complex vaccine can induce immune responses against the HER2/neu/c-erbB2 (HER2) expressing tumors. Bone marrow-derived dendritic cells (DCs), as antigen presenting cells (APCs), are the first candidates for presentation of tumor antigens. The aim of this study was to see whether DCs are able to elicit antigen specific host immune responses by stimulating the proliferation of T cells after exposure to cholesteryl group bearing pullulan (CHP) and HER2 protein complex. Vaccination by CHP-HER2 complex was as effective as cholesteryl group bearing mannan (CHM) and HER2 complex on which we reported previously. Immunization of mice with HER2 expressing CMS17HE tumor cells generated both CD4+ T cells and CD8+ T cells reactive with CHP-HER2 complex pretreated DCs. In addition, immunization with either CHP-HER2 complex or HER2 protein alone could also generate both CD4+ T cells and CD8+ T cells specifically reactive with CHP-HER2 complex pretreated DCs. The complete rejection of tumors occurred when immunization with CHP-HER2 complex pretreated DCs was started 10 days after tumor inoculation. Therefore, bone marrow-derived DCs pretreated with hydrophobized polysaccharide/oncoprotein complex are a powerful tool for enhancing the effectiveness of oncoprotein for anti-tumor vaccination, opening new options for immune cell therapy.

Animals↗
PubMed1999

Brasilicardin A, a new terpenoid antibiotic from pathogenic Nocardia brasiliensis: fermentation, isolation and biological activity.

A novel tricyclic diterpenoid antibiotic, brasilicardin A, was isolated from the culture broth of Nocardia brasiliensis IFM 0406. The antibiotic exhibited immunosuppressive activity in a mouse mixed lymphocyte reaction (MLR) assay system and its IC50 value was 0.057 microg/ml. Although the inhibitory activity of cyclosporin A (CyA) against IL-2 production was confirmed in the MLR assay system, brasilicardin A did not have the activity. The results of in vitro toxicity testing of brasilicardin A against various human cell lines were compared with those of CyA.

Aminoglycosides↗
PubMed1999

[Outbreak of tuberculosis among middle aged employees in an office].

We experienced an outbreak of tuberculosis in a salesmen's office during the period from 1993 to 1997. The outbreak was detected retrospectively. In July, 1997, a 47-year-old man was diagnosed as pulmonary tuberculosis. As he worked with a 42-year-old man who was already registered in our health center, we suspected an outbreak and started a survey. Contact examinations were carried out for 9 employees of his office and 3 members of his friends. As the result of these examinations, one employee showed strongly positive tuberculin skin test, and was indicated isoniazid chemoprophylaxis. Furthermore, some contacts told us that seven cases of active tuberculosis and three cases of primary infection indicated chemoprophylaxis had occurred among employees and their family members. The index case was a 41-year-old man who was diagnosed as tuberculosis in January, 1993. The second case among employees had previous history of pulmonary tuberculosis. Almost the patients among the employees had a hard life suffering from debts, and had heavy alcohol use. These facts may partly explain the spread of tuberculosis in this office. As each case was registered at different health centers, we hadn't noticed the outbreak for 4 years. But it is true that insufficient approach of health centers to contacts caused a serious delay of detecting the outbreak. A thorough investigation for contacts and complete contact examinations are needed.

Adolescent↗
PubMed1998

Effects of SN-38 (an active metabolite of CPT-11) on responses of human and rodent cells to irradiation.

PURPOSE: Modulators of the DNA-unwinding enzyme, topoisomerase I (Topo I), inhibit DNA repair and have been reported to increase the lethal effects of X rays, which create breaks in DNA. CPT-11 is a derivative of camptothecin, a Topo I inhibitor, and is clinically available. In this study, we tested the in vitro combination effects of SN-38, an active form of CPT-11, and irradiation on several cell lines. MATERIALS AND METHODS: Exponentially growing or confluent cultures of CHO cells were treated with SN-38 for 30 min. Cells were then irradiated. Thereafter, the cells were further incubated with the drug for 0 to 3 h. Exponentially growing other cell lines were exposed to 200 nM SN-38 for 30 min before, during, and 3 h after irradiation. The cell survival rate was determined using a conventional clonogenic assay. RESULTS: SN-38 (200 nM to 4 microM) alone showed slight toxicity to CHO cells in the confluent culture after a 3.5-h incubation. When the cells were treated with the lower doses of SN-38 (50 to 800 nM) during the exponentially growing phase, the cell survival rates were much lower. In combination with irradiation, SN-38 showed only additive effects to irradiation when cells were treated in confluent cultures. However, higher combination effects of SN-38 and irradiation were observed in the cells treated in the exponentially growing phase. When cells were irradiated during the exponentially growing phase, a significant combination effect of 200 nM SN-38 and irradiation was also observed in some cell lines, but not in others. CONCLUSION: SN-38 and irradiation showed supraadditive effects in some cell lines, when treated in the exponentially growing phase, but not in other cell lines or when cells were treated in the confluent phase.

Animals↗
PubMed1998

Activation of p38 MAP kinase and JNK but not ERK is required for erythropoietin-induced erythroid differentiation.

p38 MAP kinase (p38) and JNK have been described as playing a critical role in the response to a variety of environmental stresses and proinflammatory cytokines. It was recently reported that hematopoietic cytokines activate not only classical MAP kinases (ERK), but also p38 and JNK. However, the physiological function of these kinases in hematopoiesis remains obscure. We found that all MAP kinases examined, ERK1, ERK2, p38, JNK1, and JNK2, were rapidly and transiently activated by erythropoietin (Epo) stimulation in SKT6 cells, which can be induced to differentiate into hemoglobinized cells in response to Epo. Furthermore, p38-specific inhibitor SB203580 but not MEK-specific inhibitor PD98059 significantly suppressed Epo-induced differentiation and antisense oligonucleotides of p38, JNK1, and JNK2, but neither ERK1 nor ERK2 clearly inhibited Epo-induced hemoglobinization. However, in Epo-dependent FD-EPO cells, inhibition of either ERKs, p38, or JNKs suppressed cell growth. Furthermore, forced expression of a gain-of-function MKK6 mutant, which specifically activated p38, induced hemoglobinization of SKT6 cells without Epo. These results indicate that activation of p38 and JNKs but not of ERKs is required for Epo-induced erythroid differentiation of SKT6 cells, whereas all of these kinases are involved in Epo-induced mitogenesis of FD-EPO cells.

Animals↗
PubMed1998

D-serine content and D-[3H]serine binding in the brain regions of the senescence-accelerated mouse.

An established senescence-accelerated model mouse strain, SAMP8, shows the deterioration of learning and memory compared with a normal control strain, SAMR1. D-Serine binds to strychnine-insensitive glycine binding sites of the N-methyl-D-aspartate (NMDA) receptor complex, and enhances glutamate binding to the receptor complex. To investigate the relationship of endogenous brain D-serine and the brain dysfunction caused by aging, the level of brain free D-serine and the D-[3H]serine binding to the brain samples were examined using the SAMP8 and SAMR1 mice. The free D-serine level was highest in the cerebral frontal and occipital cortices in both the SAMP8 and SAMR1; no difference in the D-serine level was shown between the two strains. A receptor autoradiographical analysis showed that the D-[3H]serine binding to the brain section was highest in the hippocampus, and the binding in the SAMP8 brains was lower than that of the SAMR1. The D-[3H]serine binding to the crude cerebral membranes indicated that the value of the total binding sites for the SAMP8 was lower than that for the SAMR1, whereas the value of the dissociation constant Kd for the SAMP8 was similar to that of the SAMR1. These results suggest that the number of D-[3H]serine binding sites was decreased in the SAMP8 compared to the SAMR1, but the affinity of D-[3H]serine to the binding sites was not altered. These results support the view that a decrease of NMDA receptor complex is involved in the age-related neural dysfunction of SAMP8 mice.

Aging↗