Biomedical subjects

M Nagai

Publications and source records attributed to M Nagai.

At least 145 records · Page 8Linked to original sources

PubMed1998

Functional polymorphism of -141C Ins/Del in the dopamine D2 receptor gene promoter and schizophrenia.

Several studies showed the density of D2 receptors was elevated in postmortem brains from schizophrenics. Genes which operate at the level of gene activation may be associated with the pathogenesis of schizophrenia. Arinami et al. [(1997) Human Molecular Genetics 6, 577-582] found a polymorphism in the 5'-flanking region of the D2 receptor gene designated as -141C Ins/Del. The promoter activity by luciferase assay of a plasmid containing the -141C Ins allele was higher than in the one containing the -141C Del allele. In addition, the -141C Ins allele frequency was significantly higher in schizophrenics than in control subjects. We replicated the -141C Ins/Del polymorphism in 170 schizophrenics and 121 healthy control subjects. The number of schizophrenics with the -141C Ins/Ins genotype was significantly higher than that of control subjects (P = 0.038). The frequency of the -141C Ins allele was significantly increased in the schizophrenics compared with the control subjects (P = 0.042). The mean age of onset for the patients with -141C Ins/Del was significantly lower than that for the patients with -141C Ins/Ins (P = 0.029). There was no association between the genotype and either positive symptoms or the response to antipsychotic medication. Our results suggest that the -141C Ins/Del polymorphism may affect the susceptibility to schizophrenia.

Adult↗

PubMed1998

Association between anxiety disorders and a functional polymorphism in the serotonin transporter gene.

Recently, individuals with the short form of the serotonin transporter were found to be associated with neurotic characteristics. An association study on this polymorphism was performed in anxiety disorder patients and control subjects. The short form allele frequency in patients tended to be higher than that in control subjects (81.7 vs. 74.5%). Although it is difficult to ascribe significance to these 'tendencies', these data may suggest that variation of this functional polymorphism makes some contribution to anxiety disorders.

Adult↗

PubMed1998

Functional polymorphism in the serotonin transporter promoter at the SLC6A4 locus and mood disorders.

BACKGROUND: Heils et al found a functional polymorphism in the transcriptional control region upstream of the serotonin transporter gene at the SLC6A4 locus. The transcriptional promoter activity of the short (s) form was less than twice that of the long (l) form of the serotonin transporter promoter gene. In addition, they found individuals with the s form with associated neurotic characteristics (e.g., anxiety, anger, hostility, and depression). The purpose of this study was to determine whether or not there is an association between this functional polymorphism and mood disorders. METHODS: The l/s polymorphism was studied in 80 patients with mood disorders and 92 control subjects. RESULTS: There was statistically no difference between mood disorders and healthy controls in either the genotype or the allele frequency. There was statistically no difference between the genotype and subdiagnosis, family history, single/recurrent episodes of depressive disorders, suicide attempts, or the mean age of onset. CONCLUSIONS: Our results suggest there is no association between the l/s polymorphism of the serotonin transporter gene and mood disorders.

Adult↗

PubMed1998

No association between anxiety disorders and catechol-O-methyltransferase polymorphism.

Several studies have shown that the morbidity risk for anxiety disorders is increased among the relatives of patients with obsessive-compulsive disorder (OCD). Recently, it was reported that a polymorphism of the catechol-O-methyltransferase (COMT) gene is significantly associated with OCD. The purpose of this study was to determine the association, if any, between the COMT polymorphism and anxiety disorders. We undertook an association study of the COMT polymorphism in 108 patients who met DSM-IV criteria for anxiety disorders and 135 healthy controls. All subjects were unrelated Japanese. The subdiagnostic groups did not differ significantly from the control group in either the genotypic or allelic frequencies. There were no statistically significant differences between the genotype and males, females, or a family history. The mean age of onset did not significantly differ among the genotypes. Our results suggest this functional COMT polymorphism does not make an important contribution to anxiety disorders in the Japanese population.

Adult↗

PubMed1998

Syntheses and structure-activity relationships of novel retinoid X receptor agonists.

As part of our studies to develop novel retinoids with increased affinity and selectivity for the retinoid X receptor (RXR) subfamily, we have designed and synthesized a series of (E,E,E)-7-(1,2,3, 4-tetrahydroquinolin-6-yl)-7-alkyl-6-fluoro-3-methylhepta-2, 4, 6-trienoic acid derivatives. These tetrahydroquinolines, generated by introducing a polar N atom into the hydrophobic part of the retinoid skeleton, showed high binding affinity to RXRs. Addition of fluorine at the 6-position of the 2,4,6-trienoic acid moiety afforded compounds which elicit potent and selective transactivation of the RXRs. Compound 14b (ER-35794), which possesses an ethyl substituent at the 7-position and fluorine at the 6-position of the triene moiety, is one of the most potent and selective RXR agonists reported to date.

Animals↗

PubMed1998

IL-4-dependent regulation of TGF-alpha and TGF-beta1 expression in human eosinophils.

TGFs play important roles in wound healing and carcinogenesis. We have previously demonstrated that eosinophils infiltrating into different pathologic processes elaborate TGF-alpha and TGF-beta1. Eosinophils infiltrating hamster cutaneous wounds were found to express TGFs sequentially. In this study, we examined the biologic mediators that may regulate the expression of TGF-alpha and -beta1 by eosinophils. Eosinophils were isolated from the peripheral blood of healthy donors and cultured in the absence or presence of IL-3, IL-4, and IL-5. Cells were analyzed by in situ hybridization and immunohistochemistry. Supernatants from these cultures were assayed for secreted TGF-alpha and TGF-beta1 using TGF-specific ELISAs. IL-3, IL-4, and IL-5 independently up-regulated TGF-beta1 mRNA and product expression by eosinophils in all donors. Interestingly, TGF-alpha production by eosinophils was up-regulated by IL-3 and IL-5 but was down-regulated by IL-4. Consistent with the ability of IL-4 to regulate eosinophil responses, IL-4 signaling molecules are present in human eosinophils. The observation that IL-4 can differentially regulate the expression of TGF-alpha and TGF-beta1 suggests that IL-4 may serve as a physiologic molecular switch of TGF expression by the infiltrating eosinophils in wound healing and carcinogenesis.

Adult↗

PubMed1998

Polymorphism in the promoter region of the alpha 2A adrenergic receptor gene and mood disorders.

Alpha 2 adrenergic receptors are thought to play a crucial role in the etiology or treatment of mood disorders. Polymorphism(s) in the promoter region of the alpha 2 receptor may affect the gene expression and be associated with mood disorders. We studied the previously reported polymorphisms of the alpha 2A receptor gene at position-1291 in 114 healthy controls and 103 mood disorder patients. There was statistically no difference between controls and patients in either the genotype or the allele frequency. There was statistically no difference between the genotype and the clinical characteristics. Our results suggest there is no association between this polymorphism in the promoter region of the alpha 2A receptor gene and mood disorders.

Alleles↗

PubMed1998

Low activity allele of catechol-o-methyltransferase gene and Japanese unipolar depression.

Several studies have shown that depressed patients have significantly lower catechol-o-methyltransferase (COMT) activity than healthy controls. Two COMT genes coding for low activity, COMTL, and high activity, COMTH have been identified. We undertook an association study on 75 depressive disorder patients, 40 bipolar disorder patients and 135 healthy controls. All the subjects were Japanese. Patients with depressive disorders exhibited a significantly higher rate of genotypes with the COMTL allele than healthy controls (p = 0.012), which was not the case in patients with bipolar disorders. The presence of the COMTL allele was significantly associated with depressive disorders (odds ratio 2.19, 95% CI 1.19-4.03). Our results suggest the COMTL allele contributed to the etiologies of depressive disorders.

Adult↗

PubMed1998

5-HT2A receptor gene promoter polymorphism--1438G/A and mood disorders.

A 5-HT2A receptor promoter polymorphism, -1438G/A, was reported to be significantly increased in patients with anorexia nervosa when compared with controls. In practice, many patients with anorexia nervosa suffer from mood disorders. Furthermore, 5-HT2A receptors are thought to play a role in the etiologies of mood disorders. Thus, we studied the polymorphism in 95 Japanese patients with mood disorders and 106 healthy Japanese controls. The allele frequency for the -1438G/A polymorphism did not differ between the patients and controls. In addition, the genotype frequencies did not differ according to the subdiagnosis, age of onset, family history of psychiatric illness or suicide attempts.

Adult↗

PubMed1998

Identification of alternative splicing forms of GLT-1 mRNA in the spinal cord of amyotrophic lateral sclerosis patients.

The glutamate transporter plays an essential role in regulating glutamate levels in the synaptic cleft. It has been postulated that the dysfunction of GLT-1, one subtype of glutamate transporter, may be etiologically related to amyotrophic lateral sclerosis (ALS). Two alternative splicing forms of GLT-1 messenger RNA (mRNA) were found in the cervical spinal cord of five ALS patients and three controls. Analysis with reverse transcription-polymerase chain reaction (RT-PCR) showed that the shorter mRNA was a result of exon 8 skipping. A truncated transcript containing an intronic sequence at the 3' end of exon 7 was also demonstrated. However, the incidence of both alternative mRNAs was not different between the five ALS patients and three controls. Interestingly, the mRNA were also found in the cerebral cortex of a control subject. These results suggest that alternative splicing forms of GLT-1 mRNAs do not play a pathogenetic role in ALS but rather a physiological one in the normal spinal cord and brain.

ATP-Binding Cassette Transporters↗

PubMed1998

Nucleotide sequence homology to bovine viral diarrhea virus 2 (BVDV 2) in the 5' untranslated region of BVDVs from cattle with mucosal disease or persistent infection in Japan.

Cytopathogenic and non-cytopathogenic bovine viral diarrhea viruses (BVDVs) were isolated from cattle with mucosal disease or persistent infection in Japan. These isolates were compared for antigenic properties by cross-neutralization tests with Japanese reference strains of BVDV belonging to classical type 1. Significantly low cross-reactivity to reference strains was noted, indicating the viruses to possibly represent a new serotype in Japan. Thus, to determine the genotype of the isolates, nucleotide sequences of the 5' untranslated region were determined and compared with those of previously reported BVDV 1 and 2. The isolates were clearly shown to belong to BVDV 2, not to BVDV 1.

Animals↗

PubMed1998

Deficient heme and globin synthesis in embryonic stem cells lacking the erythroid-specific delta-aminolevulinate synthase gene.

The erythroid-specific isoform of delta-aminolevulinate synthase (ALAS-E) catalyzes the first step of heme biosynthesis in erythroid cells, and ALAS-E gene mutations are known to be responsible for x-linked sideroblastic anemia. To study the role of ALAS-E in erythroid development, we prepared mouse embryonic stem (ES) cells carrying a disrupted ALAS-E gene and examined the effect of the lack of ALAS-E gene expression on erythroid differentiation. We found that mRNAs for erythroid transcription factors and TER119-positive cells were increased similarly both in the wild-type and mutant cells. In contrast, heme content, the number of benzidine-positive cells, adult globin protein, and mRNA for beta-major globin were significantly decreased in the mutant cells. These results were confirmed using another ES differentiation system in vitro and suggest that ALAS-E expression, hence heme supply, is critical for the late stage of erythroid cell differentiation, which involves hemoglobin synthesis.

5-Aminolevulinate Synthetase↗

PubMed1998

Thymic B-cell non-Hodgkin's lymphoma in a child.

A 13-year-old male developed thymic non-Hodgkin's lymphoma. Microscopically, the tumor was composed of large cells, resembling centroblasts. Immunohistochemically, the tumor demonstrated leukocyte common antigen+, L26 (B-cell)+, UCHL1 (T-cell)-, suggesting the B-cell phenotype. In contrast to the terminally differentiated phenotype (CD10-, surface immunoglobulin-) observed in adult cases, flow cytometric analysis showed that they were relatively immature: CD10+, CD19+, HLA-DR-, IgM+/-, kappa+. He was successfully treated with intensive chemotherapy. Since childhood thymic lymphomas are exclusively small non-cleaved cell lymphoma with T-cell phenotype, this case represents a unique entity in children.

Adolescent↗

PubMed1998

CD4+ T-lymphocytopenia in long-term survivors following intensive chemotherapy in childhood cancers.

BACKGROUND: It is generally believed the effects of short intensive courses of therapy are rapidly reversible in childhood cancers, and immunologic function following years of maintenance treatment with chemotherapy usually returns to normal by 6 months or less when treatment is terminated. However, we previously demonstrated that dysregulation of immunoglobulins, especially IgD, was observed in long-term survivors following intensive chemotherapy in cancer patients. With regard to cellular immunity, investigators reported that antineoplastic chemotherapy significantly reduces the number of CD4+ T-lymphocytes, and production of newly developing CD4+ T-lymphocytes was inversely related to the patients' age. However, the incidence of CD4+ lymphocytopenia in long-term survivors of childhood cancers is not known. PROCEDURE: Here, we report the flow cytometric analysis of peripheral blood from long-term survivors who continue complete remission off chemotherapy for more than 5 years. RESULTS: Six out of 74 long-term survivors (8.1%), showed low CD4+ T-lymphocyte count (<300/mm3). Three of six patients showed continued CD4+ T-lymphocytopenia over a year. In spite of the persistent low levels of CD4+ T cells, these three patients were not susceptible to severe infections. COMMENT: Intriguingly, in patients with CD4+ T-lymphocytopenia there has been a tendency toward increased numbers of natural killer cells or gamma delta T cells that may be operating as a thymus-independent compensatory mechanism to defend the hosts.

Adolescent↗

PubMed1998

Electrophoretic coating of multilayered apatite composite on alumina ceramics.

By means of an electrophoretic deposition technique followed by sintering, alumina and zirconia ceramics were coated with apatitic composites composed of porous surface and intermediate layers of hydroxyapatite and an adhesive calcium phosphate layer. The electrophoretic deposition of these layers was attained by the use of a mixed solvent of acetylacetone and alcohol as well as the mixed powders of the calcium phosphates and alumina. The adhesive layer was formed by the codeposition of calcium phosphate glass powders (Ca/P = 1/2) with hydroxyapatite, while the open porosity of the surface layer was increased with the addition of alumina to the hydroxyapatite layers. The resultant phases of sintered composite layers were tricalcium phosphate and alumina with a small amount of hydroxyapatite.

Aluminum Oxide↗

PubMed1998

Primarily extracranial jugular foramen neurinoma manifesting with marked hemiatrophy of the tongue: case report.

BACKGROUND: There have been no detailed descriptions of the clinical symptoms of a primarily extracranial jugular foramen neurinoma (JFN), because this type of tumor is extremely rare. CASE DESCRIPTION: Although the 51-year-old woman presented with only mild complaints of dysphagia and hoarseness, neurologic examination revealed marked left hemiatrophy of the tongue. Although magnetic resonance imaging suggested a JFN, the patient's mild symptoms and normal jugular foramen were potentially misleading in the diagnosis of this patient. Surgical exploration demonstrated that the tumor originated from the extracranial portion of the 10th cranial nerve, extending into the jugular foramen. Subtotal resection ameliorated the 12th cranial nerve palsy. CONCLUSION: The authors present a case of a primarily extracranial JFN manifesting as a 12th nerve palsy. The clinical symptoms and signs produced by a tumor in this extremely rare location are discussed.

Atrophy↗

PubMed1998

Suppression of alloreactivity with gamma delta T-cells: relevance to increased gamma delta T-cells following bone marrow transplantation.

Several reports have shown that an increase in T-cell receptor gamma/delta-positive T-cells (gamma delta T-cells) have been observed following bone marrow transplantation. gamma delta T-cells expanded from peripheral blood mononuclear cells from normal volunteers were used to investigate the function of gamma delta T-cells in vitro. Peripheral blood mononuclear cells were cultured with synthetic ligand of gamma delta T-cells, monoethyl phosphates (MEP), for 7 days. MEP specifically expanded gamma delta T-cells. Expanded gamma delta T-cells from subject "B" were added to an A anti-B or A anti-C mixed lymphocyte culture (MLC) containing responder cells from subject "A" and irradiated stimulator cells from subjects "B" or "C". The cultures were harvested on day 6 and tested for cytotoxicity against stimulator-type Con A blasts. gamma delta T-cells from subject "B" specifically inhibit generation of allospecific cytotoxic T lymphocytes (CTL) in A anti-B MLC. The results indicate that gamma delta T-cells exhibit veto-type suppression of alloreaction. If the current experiments are also applicable in vivo, gamma delta T-cells originating from the donor after bone marrow transplantation may inhibit graft rejection by suppressing recipient anti-donor reactivity. gamma delta T-cells may be involved in the suppression of allogeneic reaction in vivo following allogeneic bone marrow transplantation.

Bone Marrow Transplantation↗

PubMed1998

Biological effects of a relatively low concentration of 1-beta-D-arabinofuranosylcytosine in K562 cells: alterations of the cell cycle, erythroid-differentiation, and apoptosis.

Therapeutic strategies for leukemia are directed to induction of differentiation and apoptosis as well as growth inhibition. One of the key antileukemic agents, 1-beta-D-arabinofuranosylcytosine (ara C), is clinically applied according to these therapeutic aims. However, the molecular effects of 0.1 microg/ml of ara C, a concentration that corresponds to the serum level in leukemic patients on a conventional dose of ara C, have not been well disclosed. Here, we addressed these issues using K562 cells which derived from a blastic crisis of chronic myeloid leukemia. DNA synthesis of treated cells was suppressed from 1-6 h. But, it recovered at 12 h and no further inhibition was observed. The number of cells was not decreased but DNA fragmentation was observed at 72 h. The number of erythroid-differentiated cells also increased to 30% at 72 h. Along with treatment, no marked alteration of mRNAs for cell cycle-regulating genes was found and the retinoblastoma gene product remained hyperphosphorylated throughout treatment. The expression of mRNAs for apoptosis-regulating genes also remained unchanged, except for slight down-regulation of Bax. c-myc protein was not found later than 48 h, and Max mRNA was downregulated. c-jun was immediately induced, followed by the fluctuated expression level along with treatment. These findings suggest that the 0.1 microg/ml ara C changed the proliferation, differentiation and death of K562 cells in a biphasic manner. In the early phase, DNA synthesis was inhibited without altering the expression of cell cycle regulating-genes. In the latter phase, cell death and erythroid- differentiation occurred in accordance with the down-regulation of c-myc.

Apoptosis↗