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Biomedical subjects

K Matsubara

Publications and source records attributed to K Matsubara.

At least 181 records · Page 10Linked to original sources
PubMed1996

Molecular cloning of a human neuroD from a neuroblastoma cell line specifically expressed in the fetal brain and adult cerebellum.

Several neuron-specific cDNAs were identified using large-scale collection of 3'-directed partial cDNA sequences from a human neuroblastoma cell line. One of such cDNAs encoded a protein homologous to the mouse NeuroD. The mouse NeuroD, a basic helix-loop-helix (bHLH) protein seems to function as a differentiation factor for neurogenesis, as the gene is transiently expressed in postmitoic differentiating neurons. The human counterpart has a bHLH domain completely identical to that of the mouse NeuroD. But its expression was not only in the fetal brain but also in the adult cerebellum. The result of cross-species in situ hybridization also showed the transcripts were detected in the granule cell layer of the adult mouse cerebellum. The results suggest that the human as well as the mouse neuroD may play some important functions not only in the fetal brain but also in the fetal brain but also in the matured neurons of the cerebellum.

Amino Acid Sequence↗
PubMed1996

Hypoalbuminemia, oliguria and peripheral cyanosis in an infant with severe atopic dermatitis.

A six-month old male infant with severe atopic dermatitis was admitted with hypoalbuminemia, oliguria and cyanosis of the extremities. There was marked edema and generalized eczema with foul, yellowish exudates. The patient's major clinical manifestations were attributed to the loss of albumin through the skin. Although atopic dermatitis is a common disease in children, here we want to show that systemic disturbances may arise from such condition, describe the total care given the patient, and emphasize the wholistic approach in managing cases of severe atopic dermatitis. Intensive treatment was instituted and the patient was discharged after three weeks and remained in a stable condition.

Cyanosis↗
PubMed1996

Non-existence of a positive correlation between urinary levels of alpha 1-microglobulin and ulinastatin in patients with Parkinson's disease.

Urinary levels of alpha 1-microglobulin (alpha 1M) and of ulinastatin (UT) and the alpha 1M/UT ratio did not differ significantly between age-matched controls and patients with Parkinson's disease, and among subdivided groups based on Yahr's stages in Parkinson's disease. Furthermore, these indexes did not correlate with Yahr's stages. Although alpha 1M and UT levels did not correlate in patients with Parkinson's disease, a positive correlation was observed in the control group. The non-existence of a positive correlation between alpha 1M and UT levels distinguishes Parkinson's disease from other neuropsychiatric diseases such as dementia (Alzheimer-type and vascular dementia), schizophrenia and mood disorder.

Aged↗
PubMed1996

The human genome efforts and the cDNA project.

Molecular biology has been moving swiftly toward clarifying the entire genome of organisms, including human. The human genome efforts that promote this transaction are characterized by the large-scale, high throughput production of data about the structure of the genome of the molecular level and its computer-assisted management. In addition, functional analyses of the genome have become important for decoding the entire genetic information carried in the human genome. In the functional analyses of the genome, the large-scale collection of partial cDNA sequences, the cDNA project, is becoming important, because it allows researchers to register genes active in any given tissue, on one hand, and, on the other hand, it allows for quantitative description of gene activities in tissues. Tissue-specific or stage-specific genes can be discovered by comparing expression profiles from different tissues or from a tissue at different stages of development, respectively.

DNA, Complementary↗
PubMed1996

A gene expression profile of human corneal epithelium and the isolation of human keratin 12 cDNA.

PURPOSE: To describe the quantitative and qualitative aspects of gene expression in human corneal epithelium and to discover novel cornea-specific genes. METHODS: A 3'-directed cDNA library was constructed with messenger RNA prepared from normal human corneal epithelial cells, and inserts in 1069 randomly chosen clones were sequenced. These sequences were compared with each other to determine the frequency of appearance and were searched against GenBank for identification. The resultant expression profile, a list of gene species and their recurrences, reflected the composition of mRNA in the cornea. Recurrently appearing sequences, representing abundant transcripts, were compared with sequences in expression profiles obtained from seven other tissues and from those in dbEST to discover cornea-specific genes. RESULTS: The expression profile of human corneal epithelium showed that the most abundant transcript in this tissue was that for apolipoprotein J. Altogether 62 genes were suggested to be very active, including calcyclin, alpha-enolase, keratin 3, connexin 43, and 12 novel genes. The expression of four of these 12 novel genes seemed to be limited to cornea because they were not found in seven other expression profiles nor in dbEST. Full-length cDNA corresponding to one of these (GS8025), isolated from a separately made cDNA library, contained open reading frame highly homologous to mouse keratin 12, which is known to be cornea specific. CONCLUSIONS: An expression profile of corneal epithelium provides probes to monitor physiological and pathologic conditions of this tissue in terms of gene expression. Furthermore, by comparing this profile with those of other tissues, probes to isolate genes uniquely transcribed in corneal epithelium are determined. These genes are assumed to carry unique functions for this tissue and are candidate genes for inherited diseases that manifest only in cornea. As an example, human cornea-specific keratin was isolated, and partial cDNA sequences for three more cornea-specific genes were presented.

Adult↗
PubMed1996

ABO genotyping following a single PCR amplification.

Using primers designed by Lee and Chang, 200 base-pair (bp) fragment of ABO locus was amplified by PCR, which spans the site of the single nucleotide deletion associated with O allele. O allele could be identified by Kpn I digestion of the PCR product as reported. A and B alleles were also distinguishable by Mae II digestion of the product. Thus restriction digestion by Kpn I and Mae II could genotype ABO blood group following the single amplification. The nucleotide substitution in the 200-bp product between A and B alleles was also found in O allele, resulting in 2 different suballeles OA and OG. The single-strand conformational polymorphism of the PCR product was also investigated for ABO genotyping following the single amplification.

ABO Blood-Group System↗
PubMed1996

A unique and sensitive ELISA technique for typing ABH antigens in bloodstains using UEA-I lectin--the removal of detergent with a Sephadex G-25 mini-column improves sensitivity.

A unique sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of ABH antigens in bloodstains has been developed. Human anti-A and -B antisera and Ulex europaeus anti-H lectin were coated on the inner surface of microplate wells. The sample antigens from bloodstains, solubilized with n-octyl-beta-D-glucopyranoside which was then removed by passing through a Sephadex G-25 (G-25) mini-column, were placed in the wells. After washing the wells repeatedly, peroxidase-conjugated Ulex europaeus lectin I was added and incubated. Antigen activities were determined by the development of colors using o-phenylenediamine/H2O2. This technique permitted clear detection of all ABH antigens corresponding to the antisera and lectin with high sensitivities. The A and B antigens were solubilized as aggregates with H antigen from the erythrocyte membrane. Excess detergent remaining in the sample reduced the sensitivity and accuracy of this ELISA, probably due to the removal of antibody from the wells by the effect of the surfactant. The treatment of solubilized antigens with G-25, an indispensable step, eliminated the adverse effect of the detergent on the ELISA. The ELISA method reported here was proved to be easy, economical and sensitive, and this technique should be useful in the forensic practice.

ABO Blood-Group System↗
PubMed1995

Monitoring cell physiology by expression profiles and discovering cell type-specific genes by compiled expression profiles.

A gene expression profile is the list showing the expressed gene species and the abundance of their transcripts in a given cell or tissue. This list is made by constructing 3'-directed cDNA libraries consisting of only the 3'-termini of mRNA and sequencing randomly selected clones from such libraries: genes are identified by the sequences, and the composition of mRNA, which reflects gene activities, is measured from the frequency of appearance of the gene transcripts. For practical reasons, the number of sequenced clones has been limited to approximately 1000 per library at present, but the resulting profile covers almost all highly or moderately expressed genes, along with many less active genes. We constructed expression profiles from the HL60 human promyelocytic cell line and two of its derivatives, granulocytoids induced by DMSO and monocytoids induced by TPA. In HL60, a significant fraction of the abundantly expressed genes was for protein synthesis. Upon induction, these genes were partially or totally silenced; transcripts for proteins that characterize the granulocytes and monocyte-macrophages became abundant. By compiling and comparing different expression profiles, genes can be categorized into those expressed in diverse cell types and those active only in limited cell types. Although at present, the number of expression profiles that can be compiled is limited and this categorization is applicable only to abundantly expressed genes, 13 novel genes that may represent granulocyte- or monocyte-specific functions have been discovered.

Base Sequence↗
PubMed1995

N-methyl-4-phenylpyridinium and an endogenously formed analog, N-methylated beta-carbolinium, inhibit striatal tyrosine hydroxylation in freely moving rats.

The effects of N-methyl-4-phenylpyridinium (MPP+) and its endogenous analog, 2,9-di-methyl-norharmanium (2,9-Me2NH+), on in vivo tyrosine hydroxylation were evaluated in freely moving rats. MPP+ gradually but almost completely reduced tyrosine hydroxylation, even at a dose as low as 0.05 mM. This effect was considered to be caused by the inhibition of tyrosine hydroxylase (TH) activation. On the contrary, 1 mM 2,9-Me2NH+ rapidly reduced 3,4-dihydroxyphenylalanine production to 10% of the basal level only during its perfusion, indicating direct inhibition of TH activity. The present study revealed that MPP+ and 2,9-Me2NH+ were taken up into dopaminergic neurons and then inhibited in vivo dopamine synthesis prior to cell death possibly in different manners.

1-Methyl-4-phenylpyridinium↗
PubMed1995

Genomic aberrations in human hepatoblastomas detected by 2-dimensional gel analysis.

Hepatoblastoma is a frequent embryonic tumor found in children. The mechanism of its formation and development remain unknown. We analyzed genomic DNA aberrations associated with three hepatoblastomas by means of restriction landmark genomic scanning (I. Hatada et al., Proc. Natl. Acad. Sci. USA, 88:9523-9527, 1991). About 2000 NotI restriction landmarks were monitored in each of the hepatoblastomas, which revealed that the intensity of eight spots decreased in the tumor genome, suggesting allelic loss. Three of these spots were identical to those that decreased in human hepatocellular carcinomas. These results suggested that common, early events are involved in the genesis of the two types of liver tumor.

Carcinoma, Hepatocellular↗
PubMed1995

Cloning of no tI-cleaved genomic DNA fragments appearing as spots in 2D gel electrophoresis.

RLGS (Restriction Landmark Genomic Scanning) is a simple and rapid scanning of genomic DNA in two-dimensional electrophoresis. Human genomic DNA is first cleaved by NotI, and the cleaved ends are radio-labeled and cleaved further by EcoRV, followed by size-fractionation by first dimensional electrophoresis. The sample is then cleaved in situ by the second enzyme HinfI and resolved by the second dimensional electrophoresis. Nearly 2,000 spots emerge with spot intensities reflecting the copy number in the genome. Because of the resolving power and capacity to scan the entire genome, RLGS has been used to monitor genomic aberrations and imprinting. Here, we report a means of cloning the DNA in spots. The DNA was eluted and ligated to biotinylated NotI and HinfI likers followed by affinity separation using streptavidin. The ligated fragment was recovered by EcoRV cleavage, the target sequence of which was located in the NotI linker and amplified by PCR using a primer pair, the sequences of which lie in the linkers. The products were then cloned into a vector for further tests. An amplified spot in stomach cancer genomic DNA and a dwindling spot in liver cancer genomic DNA were taken as examples for cloning.

Base Sequence↗
PubMed1995

Carbohydrate gluing, an architectural mechanism in the supramolecular structure of an annelid giant hemoglobin.

We report a carbohydrate-dependent supramolecular architecture in the extracellular giant hemoglobin (Hb) from the marine worm Perinereis aibuhitensis; we call this architectural mechanism carbohydrate gluing. This study is an extension of our accidental discovery of deterioration in the form of the Hb caused by a high concentration of glucose. The giant Hbs of annelids are natural supramolecules consisting of about 200 polypeptide chains that associate to form a double-layered hexagonal structure. This Hb has 0.5% (wt) carbohydrates, including mannose, xylose, fucose, galactose, glucose, N-acetylglucosamine (GlcNAc), and N-acetylgalactosamine (GalNAc). Using carbohydrate-staining assays, in conjunction with two-dimensional polyacrylamide gel electrophoresis, we found that two types of linker chains (L1 and L2; the nomenclature of the Hb subunits followed that for another marine worm, Tylorrhynchus heterochaetus) contained carbohydrates with both GlcNAc and GalNAc. Furthermore, two types of globins (a and A) have only GlcNAc-containing carbohydrates, whereas the other types of globins (b and B) had no carbohydrates. Monosaccharides including mannose, fucose, glucose, galactose, GlcNAc, and GalNAc reversibly dissociated the intact form of the Hb, but the removal of carbohydrate with N-glycanase resulted in irreversible dissociation. These results show that carbohydrate acts noncovalently to glue together the components to yield the complete quaternary supramolecular structure of the giant Hb. We suggest that this carbohydrate gluing may be mediated through lectin-like carbohydrate-binding by the associated structural chains ("linkers").

Amino Acid Sequence↗
PubMed1995

Improvement of nasal bioavailability of luteinizing hormone-releasing hormone agonist, buserelin, by cyclodextrin derivatives in rats.

The effects of chemically modified cyclodextrins on the nasal absorption of buserelin, an agonist of luteinizing hormone-releasing hormone, were investigated in anesthetized rats. Of the cyclodextrins tested, dimethyl-beta-cyclodextrin (DM-beta-CyD) was the most effective in improving the rate and extent of the nasal bioavailability of buserelin. Fluorescence spectroscopic studies indicated that the cyclodextrins formed inclusion complexes with buserelin, which may reduce the diffusibility of buserelin across the nasal epithelium and may participate in the protection of the peptide against enzymatic degradation in the nasal mucosa. Additionally, the cyclodextrins increased the permeability of the nasal mucosa, which was the primary determinant based on the multiple regression analysis of the nasal absorption enhancement of buserelin. Scanning electron microscopic observations revealed that DM-beta-CyD induced no remarkable changes in the surface morphology of the nasal mucosa at a minimal concentration necessary to achieve substantial absorption enhancement. The present results suggest that DM-beta-CyD could improve the nasal bioavailability of buserelin and is well-tolerated by the nasal mucosa of the rat.

Absorption↗
PubMed1995

Left ventricular performance during exercise testing in patients with silent and symptomatic myocardial ischemia.

We compared cardiohemodynamic response to dynamic exercise in 32 patients with exercise-induced silent or symptomatic myocardial ischemia. All patients had coronary artery disease without prior myocardial infarction and left ventricular hypertrophy. Patients underwent supine leg-exercise testing and received right heart catheterization. All patients exhibited ischemic ST-segment depression on electrocardiogram during exercise testing. They were classified retrospectively into two groups according to the absence (n = 10, group 1) or presence (n = 22, group 2) of chest pain induced by exercise. There was no significant difference between groups in the magnitude of peak ST-segment depression. Pulmonary artery wedge pressure at peak exercise was significantly lower (p < 0.01), and the cardiac index was significantly higher (p < 0.01), in group 1 versus group 2. Our results indicate that exercise-induced left ventricular dysfunction is less severe in patients with silent myocardial ischemia than in those with symptomatic ischemia.

Adult↗
PubMed1995

N-methyl(R)salsolinol produces hydroxyl radicals: involvement to neurotoxicity.

Recently, (R)-1,2-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [N-methyl-(R)salsolinol, NM(R)Sal] and 1,2-dimethyl-6,7-dihydroxyisoquinolinium ion [DiMeDHIQ+] were found to cause a syndrome similar to parkinsonism in rodents. NM(R)Sal is produced in the brain by N-methylation of a naturally occurring catechol isoquinoline, 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [(R)salsolinol, (R)Sal], which is formed from dopamine. The mechanism of NM(R)Sal cytotoxicity to dopamine neurons was examined using in vitro experiments. NM(R)Sal was found to be nonenzymatically oxidized into DiMeDHIQ+, with concomitant formation of hydroxyl radicals. The oxidation and the radical production were completely inhibited by the antioxidants, ascorbic acid and reduced glutathione, and the radical formation was enhanced by Fe(II) and, to a less extent, by Fe(III). The oxidation of NM(R)Sal into DiMeDHIQ+ and the production of hydroxyl radicals may be essential for neurotoxicity to develop in dopamine neurons. The possible involvement of this catechol isoquinoline in the pathogenesis of Parkinson's disease is discussed.

Animals↗
PubMed1995

Micro-bead embolization of uterine spiral arteries and changes in uterine arterial flow velocity waveforms in the pregnant ewe.

The aim of the present study was to simulate the pathological uteroplacental circulation observed in complicated human pregnancies in the pregnant ewe and to analyze its velocimetric changes. Four pregnant ewes at 16-17 weeks of pregnancy were used in the study. Micro-beads (Gelfoam) were administered stepwise into the uterine artery and changes in the uterine circulation were assessed by Doppler velocimetry. Gelfoam administration successfully embolized the uterine spiral arteries located in the decidual segment. The Gelfoam embolization decreased the uterine blood flow dose-dependently from 550 +/- 48 ml/min (mean +/- SD) to 142 +/- 12 ml/min and reciprocally increased the uterine vascular resistance from 139 +/- 12 mmHg min l-1 to 540 +/- 46 mmHg min l-1 at 0 mg and 30 mg Gelfoam, respectively. It dose-dependently attenuated the pregnancy-related physiological elevation in diastolic flow velocity, while the systolic flow velocity was unaffected, resulting ina dose-dependent increase in the pulsatility index from 0.5 +/- 0.2 to 3.2 +/- 0.7 at 0 mg and 30 mg Gelfoam, respectively. The pulsatility index linearly correlated with the uterine vascular resistance, giving a high correlation coefficient of r = 0.947. It could be concluded that the uterine arterial pulsatility index is an indicator of uterine vascular resistance.

Animals↗