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Biomedical subjects

Y Matsubara

Publications and source records attributed to Y Matsubara.

At least 19 recordsLinked to original sources
PubMed2003

Introduction of exogenous DNA into gonads of chick embryos by lipofection and electroporation of stage X blastoderms in vivo.

1. In order to introduce exogenous DNA into gonads of chick embryos, stage X blastoderms of freshly laid and unincubated eggs were transfected by lipofection and electroporation in vivo. 2. The introduced DNA, green fluorescence protein (GFP) gene, was efficiently expressed in the blastoderms incubated for 24 h (78.8%, 78/99). 3. The GFP gene was present in most of the embryonic bodies and extra-embryonic membranes died by d 10 of incubation, when analysed by polymerase chain reaction. On d 16 to 20 of incubation, the GFP gene was detected in 7.0 to 20.9% of embryos in the heart, liver, stomach and brain, but not in the sartorius muscle. For the gonads, the GFP gene was detected in 22.2% (6/27) of the testes and 6.3% (1/18) of the ovaries examined. 4. These results suggest that it is possible to introduce exogenous DNA into gonads of chick embryos by lipofection and electroporation of stage X blastoderms in vivo.

Animals↗
PubMed2002

The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946.

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.

Journal Article↗
PubMed2002

Lung herniation as an anatomic consequence of pneumonectomy.

BACKGROUND: Pneumonectomy causes an overdistention of the remaining lung as an adaptive response. Excessive lung herniation occasionally causes serious lung dysfunction. METHODS: Twenty-seven patients were selected from 152 patients who underwent pneumonectomy for lung cancer between 1990 and 1998. Complete resections were accomplished; no recurrence was observed for 3 years in these 27 patients. To evaluate the extent of herniation, the Lung Herniation Index (LHI) was developed and defined as the sum of proportions of the maximal transverse length of the remaining lung divided by the transverse length of the thoracic cavity, measured at the level of the aortic arch and the inferior pulmonary vein on chest computed tomography. Sequential changes in LHI were compared between groups. RESULTS: Changes in LHI did not differ between groups delineated on the basis of an FEV1 of 70 % (p = 0.45) and RV/TLC of 40 % (p = 0.99). Patients with a low body mass index (BMI) (< 20 kg/m(2)), however, showed a significantly greater degree of lung herniation than those with a high BMI (> or = 20 kg/m(2)) (p < 0.05). CONCLUSIONS: Concomitant COPD has no effect on lung herniation. Some preventive procedure should be considered for patients with low BMI.

Adult↗
PubMed2001

Structure and expression of the glycine cleavage system in rat central nervous system.

The glycine cleavage system (GCS) is a mitochondrial multienzyme system consisting of four individual proteins, three specific components (P-, T-, and H-proteins) and one house-keeping enzyme, dihydrolipoamide dehydrogenase. Inherited deficiency of the GCS causes nonketotic hyperglycinemia (NKH), an inborn error of glycine metabolism. NKH is characterized by massive accumulation of glycine in serum and cerebrospinal fluids and severe neuronal dysfunction in neonates. To elucidate the neuropathogenesis of NKH, we cloned cDNAs encoding three specific components of the GCS and studied the gene expression in rat central nervous system. P-, T-, and H-protein cDNAs encoded 1024, 403, and 170 amino acids, respectively. In situ hybridization analysis revealed that P-protein mRNA was expressed mainly in glial-like cells, including Bergmann glias in the cerebellum, while T- and H-protein mRNAs were detected in both glial-like cells and neurons. T- and H-protein mRNAs, but not P-protein mRNA, were expressed in the spinal cord. Primary astrocyte cultures established from cerebral cortex had higher GCS activities than hepatocytes whereas those from spinal cord expressed only H-protein mRNA and had no enzymatic activity. An important role of glycine as inhibitory neurotransmitter has been established in the brainstem and spinal cord and another role of glycine as an excitation modulator of N-methyl-D-aspartate receptor is suggested in the hippocampus, cerebral cortex, olfactory bulbus, and cerebellum. Our results suggest that the GCS plays a major role in the forebrain and cerebellum rather than in the spinal cord, and that N-methyl-D-aspartate receptor may participate in neuropathogenesis of NKH.

Age Factors↗
PubMed2001

A novel mutation in glial fibrillary acidic protein gene in a patient with Alexander disease.

Alexander disease is a rare, progressive, leukoencephalopathy whose hallmark is the widespread accumulation of Rosenthal fibers. The most common form affects infants and young children, and is characterized by progressive failure of central myelination, usually leading to death before adulthood. Definitive diagnosis of Alexander disease has required biopsy or autopsy to demonstrate the presence of Rosenthal fibers. However, missense mutations in the coding region of the glial fibrillary acidic protein (GFAP) gene have recently been associated with a high percentage of pathologically proven cases. Here we report that a 10-year-old Japanese patient who showed clinical signs of Alexander disease is heterozygous for a C to T transition in which predicts a novel A244V amino acid substitution in the conserved 2A alpha-helix domain of GFAP. The nucleotide change was not found in 65 normal individuals (130 alleles). These results provide further support for a causative role for GFAP mutations in Alexander disease, and suggest DNA sequencing as an alternative diagnostic to biopsy.

Alanine↗
PubMed2001

Structure of human holocarboxylase synthetase gene and mutation spectrum of holocarboxylase synthetase deficiency.

Holocarboxylase synthetase (HLCS) is an enzyme that catalyzes the incorporation of biotin into apo-carboxylases, and its deficiency causes biotin-responsive multiple carboxylase deficiency. The reported sequences of cDNA for human HLCS from liver, lymphocyte, and KG-1 myeloid cell lines differ at their 5' regions. To elucidate variations of the human HLCS mRNA and longer 5' cDNA ends, we performed screening of the human liver cDNA library and rapid amplification of the cDNA ends (RACE). Our results suggest the existence of three types of HLCS mRNA that start at different exons. The first type starts at exon 1, and the second type starts at exon 3, and both are found in various human tissues. The third type, corresponding to the cDNA from the KG-1 cell, starts at exon 2 of the HLCS gene. Various splicing patterns from exons 3-6 were also observed. None of the variations of cDNA found created a new initiation codon. Mutation screening from exons 6-14, therefore, was sufficient to detect amino acid changes in HLCS in patients. Our direct sequencing strategy for screening mutations in the HLCS gene revealed mutations in five Japanese patients and seven non-Japanese patients. Our analyses involving 12 Japanese and 13 non-Japanese patients and studies by others indicate that (1) there is no panethnically prevalent mutation; (2) the Arg508Trp, Gly581Ser, and Val550Met mutations are found in both Japanese and non-Japanese populations; (3) the IVS10+5G-->A mutation is predominant and probably a founder mutation in European patients; (4) the 655-656insA, Leu237Pro, and 780delG mutations are unique in Japanese patients; (5) the spectrum of the mutations in the HLCS gene may vary substantially among different ethnic groups.

Base Sequence↗
PubMed2001

An amebic lung abscess: report of a case.

Recently the number of amebiasis cases has increased in Japan. Pleuropulmonary amebiasis is a very rare complication of liver amebiasis. We report herein the case of a 54-year-old man presenting with an amebic lung abscess in his right lower lung. The diagnosis of lung amebiasis was established from a direct examination of the pus in which trophozoites of Entamoeba histolytica were detected. After the oral administration of metronidazole, the laboratory findings improved and he thus underwent a right lower lobectomy. He was discharged without any relapse of infection 20 days after a thoracotomy. We conclude that a protozoan infection should thus be suspected in the case of a pleuropulmonary infection in which several types of antibiotics prove to be ineffective.

Amebiasis↗
PubMed2001

Chromosomal localization, structure, single-nucleotide polymorphisms, and expression of the human H-protein gene of the glycine cleavage system (GCSH), a candidate gene for nonketotic hyperglycinemia.

Nonketotic hyperglycinemia (NKH) is an inborn error of metabolism caused by deficiency in the glycine cleavage system (GCS); this system consists of four individual constituents, P-, T-, H-, and L-proteins. Several mutations have been identified in P- and T-protein genes, but not in the H-protein gene (GCSH), despite the presence of case reports of H-protein deficiency. To facilitate the mutational and functional analyses of GCSH, we isolated and characterized a human p1-derived artificial chromosome (PAC) clone encoding GCSH. GCSH spanned 13.5kb and consisted of five exons. Using the PAC clone as a probe, we mapped GCSH to chromosome 16q24 by fluorescence in situ hybridization. The transcription initiation site was determined by the oligonucleotide-cap method, and potential binding sites for several transcriptional factors were found in the 5' upstream region. Direct sequencing analysis revealed five single-nucleotide polymorphisms. The expression profiles of P-, T-, and H-protein mRNAs were studied by dot-blot analysis, using total RNA from various human tissues. GCSH was expressed in all 29 tissues examined, while T-protein mRNA was detected in 27 of the 29 tissues. In contrast, the P-protein gene was expressed in a limited number of tissues, such as liver, kidney, brain, pituitary gland, and thyroid gland, suggesting distinct transcriptional regulation of each GCS constituent.

Alleles↗
PubMed2001

Development of the fiber neutron monitor for the energy range 15-100 MeV on the International Space Station (ISS).

In order to investigate the space environment, a new neutron monitor has been prepared. The sensor consists of scintillation fibers (FIB) and will be on board the exposed facility of the Japanese Experimental module (Kibo) of the International Space Station (ISS). The sensor is one of the instruments which measures the particle and plasma environment around the ISS. The sensor will be used by the cosmonauts who work on the ISS, to help them avoid a strong particle radiation which may arrive soon. We believe that such an alert is necessary for the cosmonauts to prevent unnecessary radiation from the sun. Furthermore, the sensor will be very useful in understanding the particle acceleration mechanism at the solar surface. The design of the Engineering Model (EM) was finished and its properties were investigated. This report discusses these results.

Equipment Design↗
PubMed2001

Cloning of porcine IGF1 receptor cDNA and detection of sequence polymorphisms using RT-PCR.

A cDNA encoding the porcine type 1 insulin-like growth factor receptor (IGF1R) was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR). The sequence of a 4.2-kb product was determined and had an open reading frame, encoding 1367 amino acids with 98.1 and 95.2% sequence similarity to the human and rat IGF1R, respectively. In the comparison of RT-PCR derived IGF1R sequences from 12 unrelated pigs, 12 silent sequence variants were found.

Animals↗
PubMed2001

Characterization of CD44 expressed on alveolar macrophages in patients with diffuse panbronchiolitis.

Interleukin (IL)-8 may play an important role in neutrophil infiltration in the airways of patients with diffuse panbronchiolitis (DPB). Furthermore, alveolar macrophages could produce IL-8 subsequent to CD44-hyaluronic acid (HA) interaction. The purpose of this study was to evaluate the contribution of CD44 expressed on alveolar macrophages to the pathogenesis of DPB. We examined the concentration of soluble CD44 (sCD44) in bronchoalveolar lavage fluid (BALF) and CD44 expression on macrophages in BALF from patients with DPB before and after low-dose, long-term macrolide therapy. We also assessed the HA-binding ability of alveolar macrophages as a functional analysis of the CD44 molecule. The sCD44 concentration in BALF was significantly lower in patients with DPB than in healthy volunteers. Percentages of alveolar macrophages expressing low CD44 (CD44 low(+)) and HA-nonbinding alveolar macrophages were higher in patients with DPB compared with healthy volunteers. Furthermore, macrolide therapy normalized CD44 expression and HA-binding ability of macrophages in BALF from DPB patients. Our findings suggest that alveolar macrophage dysfunction could result from abnormalities of CD44 expression in patients with DPB and that these events could contribute to the pathogenesis of DPB.

Adult↗
PubMed2001

GJB2 (connexin 26) mutations and childhood deafness in Thailand.

HYPOTHESIS: The purpose of this study was to elucidate whether GJB2 mutations are responsible for childhood deafness in Southeast Asia. BACKGROUND: GJB2 mutations are responsible for a large part of childhood deafness in many countries. In Whites, there is a common mutation (35delG) that accounts for about 70 to 80% of the GJB2 mutations. Previously, we and others reported a common GJB2 mutation (235delC) in Japanese patients with prelingual deafness. The association of the 235delC mutation with a single haplotype suggested a founder effect of the mutation. METHODS: We analyzed the GJB2 gene in 17 deaf patients from 12 unrelated families in Thailand. Genomic DNA was extracted from peripheral lymphocytes of each patient and the entire coding region of the GJB2 gene was sequenced. RESULTS: GJB2 mutations were found in 4 patients in 3 families. Patient 1 was a homozygote of 235delC. Patient 2 was a compound heterozygote of 235delC and W24X (71G --> A). Patient 3A and 3B (in 1 family) were heterozygotes of a novel mutation M34L (100A --> T). CONCLUSION: The 235delC mutation may be widely distributed in Asian countries outside of Japan.

Child↗
PubMed2001

Ingestion of gelatin has differential effect on bone mineral density and body weight in protein undernutrition.

Malnutrition, particularly protein undernutrition, contributes to the occurrence of osteoporotic fracture by lowering bone mass. In this study, the effects of dietary protein on bone mineral density and body weight in protein undernutrition were compared between gelatin and milk casein. When mice were fed for 10 wk with a low protein diet containing 10(%) casein or 6% casein +4% gelatin, there was no significant difference in the final body weight between the 6% casein+4% gelatin group and the 10% casein group. In contrast, bone mineral content and bone mineral density of the femur were significantly higher in the 6% casein+4% gelatin group than in the 10% casein group. Bone mineral content and bone mineral density did not differ significantly in 14% protein groups between 14% casein and 6% casein +80% gelatin. These results suggest that gelatin has differential effects on bone mineral density and body weight in protein undernutrition.

Animals↗
PubMed2001

Localization of primordial germ cells or their precursors in stage X blastoderm of chickens and their ability to differentiate into functional gametes in opposite-sex recipient gonads.

This study was performed to determine the distribution of primordial germ cells and their precursors in stage X blastoderm of chickens. The blastoderm (Barred Plymouth Rock chickens) isolated from the yolk was separated into three portions: the central disc, the marginal zone and the area opaca. The dissociated blastodermal cells derived from the central disc, marginal zone and area opaca were transferred into a recipient blastoderm (White Leghorn chicken) from which a cell cluster was removed from the centre of the central disc. The manipulated embryos were cultured in host eggshells until hatching. The chicks were raised until sexual maturity and test mated with Barred Plymouth Rock chickens to assess the donor cell contribution to the recipient germline. Germline chimaeric chickens were produced efficiently (46.7%, 7/15) when the blastodermal cells derived from the central disc were transferred into recipient embryos of the same sex, whereas no germline chimaeric chickens were produced when the blastodermal cells derived from the marginal zone or area opaca were transferred into recipient embryos of the same sex (0/12). Germline chimaeric chickens were also produced by transfer of blastodermal cells derived from the central disc (6.7%, 1/15), marginal zone (10.0%, 1/10) or area opaca (11.1%, 1/9) into recipient embryos of the opposite sex. It is concluded that primordial germ cells are induced during or shortly after stage X and that the cells derived from the central disc have the highest potential to give rise to germ cells. Cells derived from the marginal zone and area opaca can also give rise to germ cells, although the frequency is low.

Animals↗