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Biomedical subjects

Y Tanno

Publications and source records attributed to Y Tanno.

At least 73 records · Page 4Linked to original sources
PubMed1993

[Peripheral neuropathy in large granular lymphocytic leukemia].

A 16-year old woman with LGL leukemia developed peripheral neuropathy. She showed virus-associated hemophagocytic syndrome (VAHS)-like signs including high fever, liver dysfunction, huge splenomegaly, hepatomegaly and pancytopenia. The presence of chronic active EB virus infection was proved by marked high titers for IgG and IgA antibodies to the Epstein-Barr viral capsid and early antigens and low titers of antibody to Epstein-Barr nuclear antigens. She showed dysesthesia and paresthesia of bilateral lower extremities with marked swelling and tenderness, and later developed muscular weakness and atrophy with areflexia of lower extremities. Findings of the central nervous system dysfunction were not observed except for the acceleration of jaw jerk. Pleocytosis and increased protein levels in the cerebrospinal fluid were found. Pulse therapy of methyl-prednisolone and high dose intravenous immunoglobulin therapy (20 g/day for 3 days) were effective for neurological findings. The increased neopterin in the cerebrospinal fluid suggested that peripheral neuropathy was caused by activated macrophages.

Adolescent↗
PubMed1993

[Molecular genetic analysis for myoclonus epilepsy associated with ragged-red fibers (MERRF)].

Two mutations in tRNA(Lys) gene of mitochondrial DNA were detected as the causes of this disease. We reviewed our previous studies and the recent literatures. We analyzed the mtDNA nucleotide sequence of a MERRF patient, the original case of MERRF described by Fukuhara et al., and identified a point mutation of 8,344 in tRNA(Lys) gene. This mutation detected in all 8 MERRF patients from 6 independent families, and not detected in 15 controls by polymerase chain reaction using a mismatched primer. We also quantitated the degrees of heteroplasmy of the point mutation at nt 8,344 of tRNA(Lys) in various postmortem tissues from two patients with MERRF. The percentages of the mutant mtDNA were similar in both clinically affected and unaffected tissues.

Base Sequence↗
PubMed1993

[Molecular genetic analysis for Leber's hereditary optic neuropathy (LHON)].

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease characterized of acute visual loss predominantly affecting young men. So far twelve mutations in the mitochondrial DNA have been associated in this disease. We reviewed these mutations, and showed methods to detect these mutations which are being used in our laboratory. Seven mutations (nps 3460, 5244, 7444, 11778, 13708, 15257, 15812) can be detected by the the loss of the sites, and 4 mutations (nps 4216, 4917, 11778, 3394) can be detected by the appearance of the restriction sites. Since only two mutations (nps 4160 and 14484) don't affect the restriction sites, we use mismatched primers as a method to detect the mutations by polymerase chain reaction.

Base Sequence↗
PubMed1992

Functional analysis of alternatively spliced transcripts of the human histidine decarboxylase gene and its expression in human tissues and basophilic leukemia cells.

L-Histidine decarboxylase (HisDC) is the enzyme catalyzing the formation of histamine from L-histidine. HisDC activity is expressed specifically in mast cells/basophils, endocrine cells in stomach, and histaminergic neurons in brain. As a first step in the analysis of the regulation of HisDC gene expression, we have cloned the cDNA coding for HisDC from a cDNA library of a human basophilic leukemia cell line, KU-812-F. We identified two types of HisDC cDNA, representing the 2.4-kb and 3.4-kb HisDC mRNA constitutively expressed in these cells. Sequence analysis of these cDNA revealed that the 3.4-kb mRNA contains the insert sequence of 824 bases and suggests that both 2.4-kb and 3.4-kb mRNA may represent the alternatively spliced transcripts of the HisDC gene. Using expression plasmids containing a cDNA for each HisDC mRNA, we analyzed the function of possible HisDC isoforms. We show that only the 2.4-kb mRNA encodes functional HisDC and is expressed in human brain and lung. However, we were unable to detect the 3.4-kb mRNA in these tissues. Thus, the 3.4-kb mRNA may be generated by KU-812-F cell-specific splicing of the HisDC gene transcripts. Furthermore, we demonstrated the increase in the level of 2.4-kb HisDC mRNA and HisDC activity in KU-812-F cells following treatment with phorbol 12-myristate 13-acetate.

Alternative Splicing↗
PubMed1992

Delta F508 mutation of cystic fibrosis gene is not found in chronic bronchitis with severe obstruction in Japan.

Diffuse panbronchiolitis (DPB) in Japan is a chronic bronchitis observed in nonsmoking adults, with severe obstruction and poor prognosis. DPB shares pathologic and clinical characteristics with mild adult cystic fibrosis (CF), except that CF is frequent in whites (Europeans and Americans of European descent) but not in Japanese. Recently, the cystic fibrosis transmembrane conductance regulator (CFTR) gene was identified, and a 3-base pair deletion (delta F508) was confirmed as a major mutation responsible for CF. We extracted genomic DNA from white blood cells of 17 DPB patients and from paraffin-embedded tissues of 4 DPB patients at autopsy. Two polymerase chain reaction (PCR) primers were made in exon 10 of the CFTR gene so that a three-base shorter segment of 78 base pairs was amplified from the CFTR gene with the delta F508 mutation; the DNA segment amplified from the normal gene contains an F508 area with 81 base pairs. Every DNA segment amplified from DPB patients showed a normal 81-base pair length, indicating no DNA sample contained the delta F508 mutation. These results based on delta F508 mutation analysis in the CF gene indicate that DPB may represent a disease different from CF.

Adult↗
PubMed1992

Human lung mast cells and pulmonary macrophages produce tumor necrosis factor-alpha in sensitized lung tissue after IgE receptor triggering.

Tumor necrosis factor (TNF) is considered to play a key role in the pathogenesis of allergic disorders. We examined TNF production in human lung fragments after IgE receptor triggering at mRNA and protein levels. IgE receptor triggering was performed by sensitizing lung fragments with monoclonal human IgE and then exposing them to anti-human IgE antibody. Cytotoxic activity against L929 cells appeared in the culture supernatant of lung fragments 2 h after IgE receptor triggering and increased for up to 4 h. This cytotoxic activity was completely neutralized by anti-human TNF antibody. Northern blot analysis demonstrated that 1.8-kb TNF mRNA transcripts in sensitized lung fragments were expressed as early as 1 h after IgE receptor triggering and continued up to 4 h. Immunohistochemical analysis revealed TNF localization in tissue mast cells, alveolar macrophages, tissue macrophages, and bronchial epithelial cells. Double staining with anti-TNF antibody and alcian blue clearly identified that lung mast cells are one of the TNF-positive cell types in the pulmonary tissue. With immunoelectron microscopy, TNF immunoreactivity was detected in the rough endoplasmic reticulum and the perinuclear spaces in tissue macrophages, and in the cytosol and the perinuclear spaces in bronchial epithelial cells. In addition, IgE was detected on the cell surface of mast cells, tissue macrophages, and alveolar macrophages. These results suggest that TNF is released from mast cells and pulmonary macrophages through IgE receptor triggering and may play a key role in the allergic reaction in human airway.

Animals↗
PubMed1992

Strong correlation between the number of CAG repeats in androgen receptor genes and the clinical onset of features of spinal and bulbar muscular atrophy.

X-linked spinal and bulbar muscular atrophy (SBMA), a motor neuron disease associated with androgen insensitivity, is caused by androgen receptor gene mutations with an increased number of tandem CAG repeats in exon 1. We investigated the increased number of CAG repeats in androgen receptor genes of 19 SBMA patients and found that this correlated strongly with the age at onset of muscle weakness. Thus, SBMA is the first genetic disease in which a strong correlation between the degree of genetic abnormality (number of CAG tandem repeats) and clinical phenotypic expression is demonstrable. The results further indicate that androgen gene mutation is directly involved in the degeneration of motor neurons.

Adult↗
PubMed1992

Role of chronic Pseudomonas aeruginosa infection in the development of bronchiectasis.

To understand the role of Pseudomonas aeruginosa infection in the development of bronchiectasis, we investigated by CT the presence of bronchiectasis in two groups of chronic bronchitis patients and in a control group. There were no differences in clinical or laboratory findings between groups A and B. Three observers without any knowledge of these patients reported bronchiectasis on a scale of 0 to 3 and bronchial wall thickness on a scale of 0 to 3 in each lobe of both lungs. Bronchiectasis and wall thickness scores in group A (chronic bronchitis with P aeruginosa infection) were significantly higher than bronchiectasis scores and wall thickness in group B (chronic bronchitis without P aeruginosa infection). Both scores in group B were higher than those in group C (control group). These findings support the idea that chronic P aeruginosa infection plays a role in the development of bronchiectasis.

Adult↗
PubMed1992

[Myoclonus epilepsy associated with ragged-red fibers--report of a patient with negative myoclonus].

A 21-year-old woman, who had no particular familial history, was admitted to our hospital because of hand tremor and gait disturbance. On neurological examination, she showed muscle weakness in the proximal extremities. There was an ataxia on heel-to-shin testing. Action and postural myoclonus involving the extremities were also noted. In addition, with dorsiflexion of the hands, asterixis-like movement was manifested. Pyruvate was 1.0 mg/dl and lactate was 24.1 mg/dl in cerebrospinal fluid. Brain CT scan revealed mild cerebellar atrophy. EEG showed synchronous diffuse slow wave. Median nerve SEPs showed a large N20-P25 component (20 microV). Median nerve C-reflex was not evoked. With dorsiflexion of the hands, the asterixis-like movement was induced with brief cessation of surface EMG activity in the forearm muscles, as shown by the accelerometer trace. Biopsy specimens of the biceps brachii muscle revealed numerous ragged-red fibers. By PCR-RFLP method with use of a mismatched primer, we analyzed mitochondrial DNA extracted from peripheral leukocytes. The A to G mutation at nucleotide position 8,344 in a tRNA(Lys) gene of a mitochondrial genome was detected. In this patient, clonazepam was effective on the asterixis-like movements. From existence of positive myoclonus, giant SEPs and efficacy of clonazepam, we considered this movement to be negative myoclonus. Our study indicated the possibility that such an involuntary movement could be induced by certain posture in patients with MERRF.

Adult↗
PubMed1991

Quantitation of mitochondrial DNA carrying tRNALys mutation in MERRF patients.

An A to G transition at nucleotide position 8,344 in tRNALys of mitochondrial DNA has been recently identified as a causative mutation of myoclonus epilepsy associated with ragged-red fibers (MERRF). To investigate if the degree of heteroplasmy of mitochondrial DNA is correlated with the severity of MERRF, we have developed a novel method for quantitation of the mutant mitochondrial DNA by polymerase chain reaction using a mismatched primer. With the method, populations of mutant mtDNAs from 5 cases of MERRF carrying the tRNALys mutation were analyzed. The tight linkage of the severity of symptoms and the degree of heteroplasmies is not necessarily observed for all cases, though there is a tendency that patients with less wild type mtDNAs show severer clinical symptoms and earlier onset.

Adolescent↗
PubMed1991

Distinct clustering of point mutations in mitochondrial DNA among patients with mitochondrial encephalomyopathies and with Parkinson's disease.

The total sequence data for mitochondrial DNA (mtDNA) revealed distinct clustering of point mutations (pms) in mtDNA among one patient with myoclonus epilepsy with ragged-red fibers (MERRF), two patients with Parkinson's disease (PD), two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and one patient with fatal infantile cardiomyopathy (FICM). Among 33 to 62 pms found in each patients, sequentially diverged five clusters of pms were detected and designated as C-1 to C-5. C-1, consisted of fourteen pms, existed in the MERRF patient, C-1 and C-2 (nine pms) in one PD patient, C-1 to C-3 (seven pms) in another PD patient, C-1 to C-4 (one pm) in one MELAS patient and C-1 to C-5 (three pms) in another MELAS patient and the FICM patient. From these clustering of pms, a phylogenetic tree of mitochondrial encephalomyopathies (ME) was constructed. This tree clearly indicated that the ME and PD patients are members of the same gene family, and the MELAS and FICM patients are each others' closest relative. Each patient's unique pms (14 to 28 pms) were detected and, from their characteristic features, the types of the mutations specific for the disease were classified as mit- + syn- for MERRF, mit- + p- for PD, and syn- + mit- for MELAS. An inverse relation was found between the total number of pms and life span of the MELAS and FICM patients.

Adolescent↗
PubMed1991

Simple detection of tRNA(Lys) mutation in myoclonus epilepsy associated with ragged-red fibers (MERRF) by polymerase chain reaction with a mismatched primer.

We developed a simple method for the detection of a tRNA(Lys) mutation in myoclonus epilepsy associated with ragged-red fibers (MERRF) by polymerase chain reaction with use of a mismatched primer. Although the tRNA(Lys) mutation does not alter recognition sequences for commercially available restriction enzymes, we have successfully changed two nucleotides flanking the A to G mutation at nucleotide position 8344 in a tRNA(Lys) gene of a mitochondrial genome. As a result, the mutation can be detected as a Nae I restriction fragment length polymorphism. With this method, all eight MERRF patients and an asymptomatic mother of a MERRF patient, from six independent families, had the same tRNA(Lys) mutation. Our method is simple and should also be useful for the quantitation of heteroplasmies.

Base Sequence↗
PubMed1990

Histidine decarboxylase in human basophilic leukemia (KU-812-F) cells. Characterization and induction by phorbol myristate acetate.

The human leukemic cell line KU-812-F is known to differentiate into mature basophil-like cells under serum-free culture conditions. In the present study, the activity of histidine decarboxylase (HDC), a histamine-forming enzyme, in KU-812-F cells was found to be high, ranging from 10 to 57 pmol/min/mg protein. The great variation in HDC activity appeared to be due to different percentages and degrees of maturity of basophil-like cells during differentiation of this cell line. The enzyme was inhibited by alpha-fluoromethylhistidine but not by carbidopa, was unable to form dopamine from L-3,4-dihydroxyphenylalanine, and had a Km value for histidine of 0.27 mM, indicating that it was HDC and not aromatic amino acid decarboxylase. The HDC activity increased 1.8-fold when the cells were stimulated by phorbol myristate acetate, which is known to activate protein kinase C, and this increase was blocked by staurosporine, a potent inhibitor of protein kinase C.

Alkaloids↗
PubMed1990

Production of tumor necrosis factor with IgE receptor triggering from sensitized lung tissue.

Mast cells and basophils have been known to play a central role in allergic inflammation through the release of chemical mediators by cross-linkage of IgE receptors. The IgE receptor triggering and calcium ionophore A23187 have also been shown to induce gene expression and production of tumor necrosis factor (TNF) by rat basophilic leukemia cells. In the present study, we examined whether IgE receptor triggering could induce gene expression and production of TNF in rat lung tissue. The lung tissue released not only histamine but also cytotoxic activity on L929 cells 2 and 4 h after incubation with dinitrophenyl conjugated to ovalbumin (DNP-OVA) following passive sensitization with anti-DNP monoclonal rat IgE antibody, whereas neither DNP-OVA nor anti-DNP IgE antibody could induce the cytotoxic activity when used solely. Calcium ionophore A23187 also could induce both histamine release and cytotoxic activity. These activities induced by IgE receptor triggering, A23187, and lipopolysaccharide were completely neutralized by preincubation with anti-mouse TNF-rabbit serum, but not with normal rabbit serum. Northern blot analysis using cDNA probe of mouse TNF demonstrated expression of TNF gene as early as 2 h after IgE receptor triggering. These data demonstrating that IgE receptor triggering induced gene expression and production of TNF in lung tissue suggest the participation of TNF in the pathogenesis of late asthmatic response through its biologic activities such as the attraction and activation of neutrophils and eosinophils.

Animals↗
PubMed1990

Effects of interleukin 3, interleukin 4, and fibroblasts on cultures of human lung mast cells in bronchoalveolar lavage fluids.

The effects of T cell factors, including interleukin (IL)-3 and IL-4, and fibroblasts on the growth and differentiation of human lung mast cells (MCs) obtained by bronchoalveolar lavage (BAL) were examined. The number of MCs identified by alcian blue-safranin staining was twice that of the control culture without conditioned medium (CM) when BAL cells were cultured for 2 weeks in RPMI 1640 containing 10% fetal calf serum and partially purified CM derived from PHA-stimulated lymphocytes. In the presence of both recombinant (r) IL-3 and rIL-4, the number of MCs was twice as high as the control without increase in the per-cell histamine content after 2 weeks' culture. In umbilical cord blood cultures, IL-3 plus IL-4 augmented basophilic cells about 20-fold more than the control when cultured for 2 weeks. In some cases, the percentage of safranin-positive MCs was about 2-5 fold greater, with 2-7 fold higher histamine content, when cultured for 10 days with CM and fibroblasts derived from human embryonic lung. However, in all BAL experiments, there was no increase in the total number of MCs after culture compared with the initial number of MCs, unlike the umbilical cord blood cultures. These results suggest that T cell factors, including IL-3 and IL-4, and fibroblasts may influence the phenotype and the survival of lung mast cells in BAL, whereas there was no evidence for the presence of MC precursors in BAL fluids.

Bronchoalveolar Lavage Fluid↗
PubMed1990

[Molecular genetic analysis of neurologic diseases].

With the recent progress in molecular genetics, our understanding of neurologic diseases on molecular basis has improved tremendously. Molecular analyses of gene mutations in hereditary neurologic diseases bring us not only the identification of mutations but also better understanding of molecular mechanisms involved in the neurologic diseases. We have identified a missense mutation (444Leu----Pro) in glucocerebrosidase gene of a type 2 Gaucher patient. The mutant glucocerebrosidase carrying 444Pro is unstable and degraded rapidly before the mutant protein is targetted to lysosomes. Detailed analysis on the 444Leu----Pro mutations among three phenotypes (types 1, 2 and 3) of Gaucher disease, it has been demonstrated that patients homozygous for the mutation frequently have the neurologic involvement (types 1 and 2). Very recently we have identified a mutation in tRNA(Lys) gene of mitochondrial genome of patients with myoclonus epilepsy associated with ragged-red fibers. The pathophysiologic mechanism with the tRNA(Lys) mutation is considered to be based on the impaired function of tRNA(Lys).

Amino Acid Sequence↗
PubMed1990

Production of tumour necrosis factor by mastocytoma P815 cells.

P815, a transformed mouse mastocytoma cell line, produced and released cytotoxic factors after stimulation with phorbol 12-myristate 13-acetate (PMA), but not with lipopolysaccharide (LPS), calcium ionophore A23187 and IgE receptor triggering. The cytotoxic activity was reduced 60% by antibodies to mouse tumour necrosis factor (TNF). In addition, we demonstrated that TNF mRNA was already expressed under normal culture conditions and that it increased after stimulation with PMA. Although it was unknown whether factors other than TNF were lymphotoxin or some other unknown factors, it has been suggested that mast cells have cytotoxic activity, and that they contribute to inflammatory response through the release of TNF, which has a wide range of biological activity.

Animals↗