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Biomedical subjects

T Takayanagi

Publications and source records attributed to T Takayanagi.

At least 19 recordsLinked to original sources
PubMed1998

Cyclooxygenase 2 expression by endothelin-1-stimulated mouse resident peritoneal macrophages in vitro.

Macrophages have been shown to produce endothelin and to play a role in the pathogenesis of neural damage after cerebral ischemia or vasospasm after subarachnoid hemorrhage. Cyclooxygenase 2 is induced during inflammation following brain insult and participates in inflammation-mediated neurotoxicity. However, it has not yet been established how endothelin-1 acts on cyclooxygenase 2 expression in macrophages. In the present study, we examined the effects of endothelin-1 on cyclooxygenase 2 expression and prostaglandin E2 production, and the effects of endothelin ET(A) and ET(B) receptor antagonists. Stimulation by endothelin-1 ranging from 10(-11) to 10(-9) M time and dose dependently increased the production of prostaglandin E2 and the expression of cyclooxygenase 2 protein without changing that of cyclooxygenase 1 protein, an effect which was inhibited by dexamethasone, nonsteroidal anti-inflammatory drugs and the selective endothelin ET(B) receptor antagonist, BQ788 (N-cis-2,6-dimethylpiperidinocarbonyl-L-gamma-methyl-leucyl-D-L-me thoxycarbonyl-tryptophanyl-D-norleucine). The selective endothelin ET(A) receptor antagonist, BQ123 [cyclo (D-Trp-D-Asp-Pro-D-Val-Leu)] also inhibited these reactions, but its potency was less than that of the selective endothelin ET(B) receptor antagonist. Endothelin ET(A) and ET(B) receptor antagonists had no effects on cyclooxygenase 2 protein expression and prostaglandin E2 production in lipopolysaccharide-stimulated macrophages. We conclude that endothelin-1 increases cyclooxygenase 2 protein expression and prostaglandin E2 production via mainly endothelin ET(B) receptors and partly endothelin ET(A) receptors in macrophages; however, lipopolysaccharide increases both cyclooxygenase 2 protein expression and prostaglandin E2 production in pacrophages without involving endothelin ET(A) or ET(B) receptor-mediated processes.

Animals↗
PubMed1998

Intrathymic selection of NK1.1(+)alpha/beta T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad.

Generation and negative selection of NK1.1(+)alpha/beta T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10. D2 x DO10)F1 and (C57BL/6 x DO10)F1 mice and Rag-1(-/-)/DO10 mice, which had been established by breeding and backcrossing between Rag-1(-/-) and DO10 mice. Almost all T cells from these mice were shown to bear Valpha13/Vbeta8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1(+) Valpha13/Vbeta8.2(+) thymocytes was generated in these mice. However, the actual cell number of both NK1.1(+) and NK1.1(-) thymocytes in I-Ad/d mice (positive selecting background) was larger than that in I-Ab/d mice (negative selecting background). Markedly low but significant proportions of NK1.1(+) Valpha13/Vbeta8.2(+) cells were detected in the spleens from I-Ad/d and I-Ab/d mice. It was shown that the splenic NK1.1(+) T cells of the I-Ab/d mice were anergized against stimulation through TCR. When (B10.D2 x DO10)F1 and (C57BL/6 x DO10)F1 mice were given cOVA, extensive or intermediate elimination of NK1.1(+)alpha/betaTCR+ thymocytes was induced in I-Ad/d or I-Ab/d mice, respectively. However, the clonal elimination was not as complete as that seen in the major NK1.1(-) thymocyte population. The present findings indicate that normal generation of NK1.1(+)alpha/betaTCR+ thymocytes occurs in the absence of Valpha14-Jalpha281 and that substantial negative selection operates on the NK1.1(+)alpha/betaTCR+ cells.

Animals↗
PubMed1998

Production of interleukin-12 and expression of its receptors by murine microglia.

Production of interleukin-12 (IL-12) by cultured murine microglia and astrocytes was examined, by means of ELISA to detect heterodimeric p70 and RT-PCR to analyze the expression of mRNA encoding p35 and p40. Microglia, but not astrocytes, produced IL-12 p70 in response to lipopolysaccharide and interferon-gamma. The microglial cell line, Ra2, produced only p40, but not p35, upon above stimulation. Thus, it is possible that some population of microglia induce helper 1 type T cell response via producing IL-12 in the CNS. Microglia were induced to express mRNA encoding IL-12 receptors which were exclusively expressed in activated T and NK cells.

Animals↗
PubMed1998

Bullous pemphigoid associated with Shy-Drager syndrome.

We report a patient with Shy-Drager syndrome who developed multiple tense blisters mainly on the extremities. Circulating anti-basement membrane zone autoantibodies were detected by the indirect immunofluorescence method. Immunoblot analysis using normal human epidermal extracts demonstrated that this patient's serum reacted only with 230 kD bullous pemphigoid antigen (BPAG1). Concerning the pathoetiology of the association of bullous pemphigoid and Shy-Drager syndrome, we discuss a sequence similarity between BPAG1 and dystonin, a candidate gene for dystonia musculorum.

Autoantibodies↗
PubMed1998

CAG repeat expansions in patients with sporadic cerebellar ataxia.

CAG repeat expansions cause spinocerebellar ataxia type 1 (SCA1), SCA2, SCA3, SCA6 and dentatorubral-pallidoluysian atrophy (DRPLA). So far these expansions have been examined mainly in ataxia patients with a family history. However, some sporadic cases with SCA have recently been reported. To elucidate the frequency and characteristics of sporadic SCAs, we screened 85 Japanese ataxia patients without a family history for the SCA1, SCA2, SCA3, SCA6 and DRPLA mutations. As a result, 19 patients (22%) were found to have expanded CAG repeats. Among sporadic SCAs, the SCA6 mutation was most frequently observed. The sporadic SCA6 patients had smaller CAG repeats and a later age of onset than SCA6 patients with an established family history. We also identified one father-child pair in which intermediate sized CAG repeats expanded into the SCA2 disease range during transmission. These findings suggest that patients with ataxia even without a family history should be examined for a CAG repeat expansion.

Age Factors↗
PubMed1998

Identification of a new fluke allergen identified by monoclonal IgE antibodies for Paragonimus miyazakii.

IgE-producing hybridomas were acquired from fusing splenic cells to myeloma cells of BALB/c mice infected with Paragonimus miyazakii. With the use of the monoclonal antibody (mAb)xIgE obtained, the localization of the allergen in P. miyazakii, as well as its molecular weight, was evaluated. The allergen was present in the gut epithelium and luminal contents of adult flukes. Because this allergen was absent in the related species Paragonimus westermani and Paragonimus ohirai, we believe that it is specific to P. miyazakii. The allergen was estimated to be less than 14,400 daltons and was 1 of the smallest components that appeared after electrophoresis.

Allergens↗
PubMed1998

[A case of acute multifocal motor neuropathy with conduction block after Campylobacter jejuni enteritis].

The patient was a 25-year-old male with acute multifocal motor neuropathy with conduction block (MMNCB) after Campylobacter jejuni enteritis. After having suffered from diarrhea for 3 days, he rapidly developed asymmetrical distal-dominant muscle weakness in all extremities. Sensory disturbance was unremarkable except for slight disturbance in deep sensation. Deep tendon reflexes were normal throughout the course of present illness. CSF analysis revealed increased protein up to 66 mg/dl without pleocytosis. In electrophysiological examinations, persistant multifocal conduction blocks in the motor nerves were predominantly noted in the distal part of the extremities. Serum titers of anti-Campylobacter jejuni antibody, anti-GM1 antibody and anti-GalNAc-GD1a antibody were elevated. Muscle weakness resolved completely within 7 weeks. The sural nerve biopsy did not reveal either axonal degeneration, nor demyelination. These clinical and laboratory findings suggested that this case was most likely an acute type of MMNCB after Campylobacter jejuni enteritis.

Acute Disease↗
PubMed1998

[A case of Bartter's syndrome with chronic renal failure due to chronic interstitial nephritis].

We report a case of 45-year-old women with Bartter's syndrome and concomitant renal dysfunction. In 1986, the patient demonstrated muscle weakness and serum potassium levels as low as 1.1 mEq/l. She was suspected of having Bartter's syndrome because of hypokalemia, metabolic alkalosis, hyperreninemia, hyperaldosteronism and normotension. Pretibial edema developed in 1989 for which she received 40 to 100 mg/week of furosemide intermittently for the next 5 years. Her serum potassium level ranged from 1.5 to 3.9 mEq/l. In 1991, her serum creatinine level rose to 2.1 mg/dl, then continued to increase gradually. She was admitted to our hospital in 1994 for evaluation of the renal dysfunction. Decreased creatinine clearance (44 ml/min) and a defect in urinary concentrating capacity (Fishberg's test, 370 mOsm/kg.H2O) were detected. Renal biopsy revealed juxtaglomerular cell hyperplasia. These findings resulted in the diagnosis of Bartter's syndrome. The renal biopsy also showed diffuse interstitial fibrosis and marked tubular atrophy. We postulate in this case that long-term hypokalemia due to Bartter's syndrome and the administration of furosemide led to chronic interstitial nephritis and renal dysfunction.

Bartter Syndrome↗
PubMed1998

[A report of two siblings with both maternal dentato-rubro-pallido-luysian atrophy and paternal Ehlers-Danlos syndrome type III].

The report deals with the first description of two siblings, a 43-year-old woman and 39-year-old man, who have developed cerebellar ataxia, choreoathetosis, dementia, epilepsy, hyperelasticity of the skin, and hypermobility and dislocation of joints. The frequent dislocations of joints sometimes could not be corrected surgically. Their mother and maternal uncle have the same neurological signs and symptoms as the siblings do. However, they do not present with the signs of skin and joints. Gene analysis of peripheral blood lymphocytes from these 4 patients revealed that the CAG repeat length of the dentato-rubro-pallido-luysian atrophy (DRPLA) gene is increased in all four. On the contrary, their father has displayed only hyperelasticity of the skin. From the clinical signs, family history and skin biopsy, we consider that the siblings and their father have Ehlers-Danlos syndrome (EDS) type III. In conclusion, the previously unreported coincidental development of maternal DRPLA and paternal EDS observed in two siblings deserves to be described.

Adult↗
PubMed1997

International Cooperative Ataxia Rating Scale for pharmacological assessment of the cerebellar syndrome. The Ataxia Neuropharmacology Committee of the World Federation of Neurology.

Despite the involvement of cerebellar ataxia in a large variety of conditions and its frequent association with other neurological symptoms, the quantification of the specific core of the cerebellar syndrome is possible and useful in Neurology. Recent studies have shown that cerebellar ataxia might be sensitive to various types of pharmacological agents, but the scales used for assessment were all different. With the long-term goal of double-blind controlled trials-multicentric and international-an ad hoc Committee of the World Federation of Neurology has worked to propose a one-hundred-point semi-quantitative International Cooperative Ataxia Rating Scale (ICARS). The scale proposed involves a compartimentalized quantification of postural and stance disorders, limb ataxia, dysarthria and oculomotor disorders, in order that a subscore concerning these symptoms may be separately studied. The weight of each symptomatologic compartment has been carefully designed. The members of the Committee agreed upon precise definitions of the tests, to minimize interobserver variations. The validation of this scale is in progress.

Cerebellar Ataxia↗
PubMed1997

Influence of graft versus host reaction on the T cell repertoire differentiating from bone marrow precursors following allogeneic bone marrow transplantation.

When lethally irradiated AKR (Mls-1a) mice were reconstituted with bone marrow (BM) cells plus a small number (0.5%) of mature T cells from allogeneic B10.AQR or B10 (Mls-1b) mice and minor GVHR was induced in the recipients, almost complete donor chimerism was accomplished in the early stages after reconstitution. By contrast, in irradiated AKR mice reconstituted with T cell-depleted BM cells alone from B10 or B10.AQR mice, radio-resistant T cells of recipient origin persisted for a relatively long period in peripheral lymphoid tissues. In this paper the influence of residual T cells in the chimeric mice on generation of the T cell repertoire derived from donor BM is discussed. It will be demonstrated that the recipient (AKR) T cells are capable of producing Mls-1a antigens (Ag) after lethal irradiation in vivo. These recipient T cells eventually induce clonal elimination of Mls-1a reactive V beta 6+, V beta 8.1+ and V beta 9+ T cells derived from developing thymocytes of donor BM origin. The Mls-1a reactive T cells are not eliminated in GVHR chimeras in which recipient T cells are absent. However, V beta 5+ T cells reactive to I-E plus Etc-1 Ag are deleted in the chimeras undergoing GVHR. These results indicate that recipient cells which produce tissue-specific antigens (tolerogens) should be taken into consideration when generation of the T cell repertoire of donor origin following allogeneic BM transplantation is investigated.

Animals↗
PubMed1997

Effects of non-major histocompatibility antigens on acute graft-versus-host reaction after allogeneic bone marrow transplantation.

In the present study using an experimental BMT system we analyzed the effects of disparity at non-MHC Ag including minor lymphocyte stimulatory-1a (Mls-1a) Ag on the acute GVH reaction (GVHR) induced by MHC class I Ag. Mismatch at MHC (class I) Ag alone did not induce clinically detectable acute GVHR in this model. However, BMT mice prepared with a combination of both class I and non-MHC Ag mismatches showed signs of clinical GVHR and various cytokines were produced by the spleen cells at an early stage (4 days) after BMT. Although no clinical GVHR was detected in BMT chimeras prepared with a non-MHC mismatched but MHC matched combination, large amounts of various cytokines were secreted by spleen cells. Cytokine production in the latter two kinds of chimeras paralleled the increase of Mls-1a reactive Vbeta6+ T cells in the host spleen. Marked cytokine production induced by Mls-1a Ag was confirmed by MLR. Thus, these cytokines appeared to be produced by T cells responding to Mls-1a (ie Vbeta6+ T cells) and to augment the T cell responses to MHC class I which resulted in clinically detectable GVHR in chimeras prepared with the combination mismatched at both MHC class I and non-MHC loci.

Animals↗
PubMed1997

Spinocerebellar ataxia type 6. Molecular and clinical features of 35 Japanese patients including one homozygous for the CAG repeat expansion.

Spinocerebellar ataxia type 6 (SCA6) is a newly classified autosomal-dominant cerebellar ataxia (ADCA) associated with CAG repeat expansion. We screened 111 patients with cerebellar ataxia for the SCA6 mutation. Of these, 35 patients were found to have expanded CAG repeats in the SCA6 gene, indicating that second to SCA3, SCA6 is the most common ADCA in Japan. Expanded alleles ranged from 21 to 29 repeats, whereas normal alleles had seven to 17 repeats. There was no change in the CAG repeat length during meiosis. The age at onset was inversely correlated with the repeat length. The main clinical feature of the 35 patients with SCA6 was slowly progressive cerebellar ataxia; multisystem involvement was not common. The 35 patients included nine cases without apparent family history of cerebellar ataxia. The sporadic cases had smaller CAG repeats (21 or 22 repeats) and a later age at onset (64.9 +/- 4.9 years) than the other cases with established family history. We also identified one patient who was homozygous for the SCA6 repeat expansion. The homozygote showed an earlier age of onset and more severe clinical manifestations than her sister, a heterozygote carrying an expanded allele with the same repeat length as the homozygote. This finding suggests that the dosage of the CAG repeat expansion plays an important role in phenotypic expression in SCA6.

Adult↗
PubMed1997

[A family with dentato-rubro-pallido-luysian atrophy (DRPLA): an intergenerational contraction of the CAG repeat].

We describe the relation of the CAG repeat length to the genetic anticipation in a Japanese family with dentato-rubro-pallido-luysian atrophy (DRPLA). The proband, a 21-year-old woman, developed epilepsy at age 19. Her mother has displayed cerebellar ataxia, choreoathetosis, and dementia since age 40, and the grandmother has shown cerebellar ataxia since age 52. So a genetic anticipation was observed. The CAG repeat sizes of peripheral blood lymphocytes from the proband, mother, and grandmother were found to be 61, 59, and 60, respectively. Thus, the mother showed earlier onset but a smaller CAG repeat length as compared to the grandmother. This case is thought to be rare and valuable in respect that the intergenerational contraction of the CAG repeat was shown in spite of the genetic anticipation was observed.

Adult↗
PubMed1997

[A case of dystrophia myotonica with homozygous DM kinase abnormalities].

We report a case of dystrophia myotonica (DM) in a 38-year-old man with homozygous DM kinase abnormality. His distal muscle strength was reduced moderately; muscle biopsy showed type 1 predominance and type 1 fiber atrophy. The patient's WAIS total IQ score was under 60. Since his childhood, his cognitive deficit has been more severe than his muscle weakness. MRI demonstrated many abnormal changes in the brain of this patient, but these changes were mild in comparison to the severity of his reduced cognition and low IQ. The relationship between mental dysfunction and DM kinase abnormalities is quite different from that seen in cases of heterozygous DM kinase abnormalities. This case demonstrated severe mental changes in spite of mild DM kinase abnormalities. We suspect the homozygous DM kinase abnormality to be a cause of the different clinical presentations of this patient.

Adult↗
PubMed1997

[An apparently sporadic case with spinocerebellar ataxia type 1 (SCA1)].

We reported a sporadic case with late onset SCA1. There was no family history of neurological diseases. His parents had been healthy until they died at the age of 77 and 89 years, respectively. The patient noticed gait disturbance at age of 60. Thereafter, he gradually developed cerebellar ataxia, hyporeflexia, mild atrophy of the facial and limb muscles and moderate deep sensory disturbance. MRI of the brain showed moderate atrophy of the cerebellum and brainstem. Sequencing analysis of SCA1 gene demonstrated that the patient had an expanded allele with 40 CAG repeats and no CAT interruption. Consequently, he was diagnosed as having SCA1. These results suggest the possibility that among apparently sporadic cases with cerebellar ataxia, there are some cases of SCA1 with mild CAG repeat expansion.

Atrophy↗
PubMed1997

[A case of idiopathic hypereosinophilic syndrome with special reference to mental disorders and brain images].

We reported a case of idiopathic hypereosinophilic syndrome with psychiatric symptoms and abnormal areas in subcortical white matter on brain MRI. The 25-year-old man was referred to us because of fever, confusional state and emotional incontinence. He soon became apathetic and emotionless. While he was confused, we studied brain CT twice and brain MRI four times. In deep white matter around the lateral ventricles and the cortices of parietal lobe, occipital lobe and cerebellar hemispheres, T1-weighted MRI revealed low intensity areas and T2-weighted MRI showed high intensity areas. After gadolinium infusion, some above-stated areas were enhanced. The lesions in the deep white matter disappeared when symptoms diminished, while lesions in the occipital cortex remained unchanged. Brain MRI studies were beneficial and useful to analyse the rare idiopathic hypereosinophilic syndrome with psychic disorders.

Adult↗