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Biomedical subjects

K Matsubara

Publications and source records attributed to K Matsubara.

At least 145 records · Page 8Linked to original sources
PubMed1997

The post-translational modifications of Ral and Rac1 are important for the action of Ral-binding protein 1, a putative effector protein of Ral.

Ral-binding protein 1 (RalBP1) is a putative effector protein of Ral and possesses the GTPase-activating activity for Rac1 and CDC42. We examined the roles of the post-translational modifications of Ral and Rac1 for the action of RalBP1. In COS cells, Ral(G23V), a constitutively active form, was mainly detected in the membrane fraction while most of Ral(G23V/C203S), a Ral mutant which is not post-translationally modified, was found in the cytosol fraction. When RalBP1 was expressed alone in COS cells, it was found in the cytosol but not in the membrane fraction. When RalBP1 was coexpressed with Ral(G23V), a part of RalBP1 was found in the membrane fraction. However, when RalBP1 was coexpressed with Ral(G23V/C203S), all of RalBP1 was recovered in the cytosol fraction. Although Ral bound to RalBP1 at a molar ratio of 1:1, the interaction of Ral with RalBP1 did not affect the GTPase-activating activity of RalBP1 for Rac1. Furthermore, RalBP1 was more active on the post-translationally modified form of Rac1 and CDC42 than the unmodified form. These results suggest that the post-translational modification of Ral is important for the subcellular localization of RalBP1 and that the interaction of Ral with RalBP1 is not essential for the activity of RalBP1 but plays a role in recruiting RalBP1 to the membrane where its substrates, Rac1 and CDC42, reside.

Animals↗
PubMed1997

Analysis of an expression profile of genes in the human adipose tissue.

Increasing evidence suggests that in addition to storing excess energy as fat, adipose tissue acts as an endocrine organ secreting various factors into the blood stream. Every time a new factor is found in adipose tissue, however, its implication is discussed independently, and a systematic analyses based upon a global view of gene expression of this tissue has not been performed. To describe the function of this tissue in terms of gene expression, and to find new factors, we performed random complementary DNA (cDNA) sequencing using a 3'-directed cDNA library that faithfully represents the composition of the messenger RNA (mRNA). Various well-known but unexpected genes, including those for gelsolin, plasma glutathione peroxidase (GPX-3) and carboxypeptidase E (CPE) were shown to be very active. By comparing the expression profile of active genes in the adipose with those of other tissues and with data in dbEST, we identified seven new genes that are specifically expressed in adipose tissue. Among these, one encoded a protein with collagen-like repeats and a putative secretion signal. These data can be used as new tools for analyses of the physiology of this tissue, as well as the etiology and complications of obesity.

Adipose Tissue↗
PubMed1997

A dopaminergic neurotoxin, 1(R), 2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, N-methyl(R)salsolinol, and its oxidation product, 1,2(N)-dimethyl-6,7-dihydroxyisoquinolinium ion, accumulate in the nigro-striatal system of the human brain.

N-Methyl(R)salsolinol was found to be an endogenous dopaminergic neurotoxin inducing parkinsonism in rodents and to increase in the cerebrospinal fluid of parkinsonian patients. The amounts of N-methyl(R)salsolinol and related compounds in the human brain regions were quantitatively analyzed. Only the (R)-enantiomer of salsolinol derivatives were detected, which suggests their enzymatic synthesis in situ. In the nigro-striatal system, the concentration of N-methyl(+)salsolinol was higher than in the frontal cortex, and its oxidized catechol isoquinolinium ion was detected only in the substantia nigra significantly. The accumulation of these neurotoxins in the nigro-striatal region might account for selective cell death of dopamine neurons in the substantia nigra of Parkinson's disease.

Chromatography, High Pressure Liquid↗
PubMed1997

Cloning of human and mouse cDNAs encoding novel zinc finger proteins expressed in cerebellum and hippocampus.

We identified a novel gene, kf-1, highly expressed in the normal cerebellum but not in the cerebral cortex, the expression of which could have been augmented in the cerebral cortex of a sporadic Alzheimer's disease patient. We cloned human and mouse entire kf-1 cDNAs encoding conserved 79 kDa proteins containing a zinc-binding RING-H2 finger motif at the carboxy-terminus as found in acetylcholine receptor-associated protein (RAPsyn). The 3'-untranslated regions are highly conserved between human and mouse as to constitute a common mRNA secondary structure. In situ hybridization analysis of mouse brain sections revealed strong kf-1 expression in the cerebellum and hippocampus. We propose that KF-1 is involved in membranous protein-sorting apparatus similarly to RAPsyn. We mapped the human kf-1 gene to 2p11.2.

Alzheimer Disease↗
PubMed1997

Validity and reliability of Structured Interview for Competency Incompetency Assessment Testing and Ranking Inventory.

The Structured Interview for Competency and Incompetency Assessment Testing and Ranking Inventory (SICIATRI) is a structured interview guide to assess the competency for giving informed consent to treatment among psychiatric and medical patients. The competency levels of 48 psychiatric and medical inpatients were assessed by SICIATRI. A relatively high- inter-rater reliability of the SICIATRI items (over half of the items had kappa > or = .60) and concurrent validity (sensitivity = .83, specificity = .67 as measured against the global judgement of competency rating by the attending physician) were obtained. In addition to its brevity (it takes about 20 minutes to complete), these findings may warrant application of this instrument in a clinical setting.

Adult↗
PubMed1997

Natural and artificial carbohydrate-glued protein aggregates.

Carbohydrate gluing (which may have a carbohydrate-lectin binding mechanism) was first recognized as a major contributor in the supramolecular assembly of annelid giant Hb from the marine-worm P. aibuhitensis. Although this assembly obviously also relies on protein-protein interactions, the authors tested the application of carbohydrate gluing in the assembly of a protein aggregate using a lectin and a carbohydrate-containing protein. The resultant aggregate was a mixture of the protein aggregate and the ingredient proteins. The significance of the method is that the assembly of the aggregate can be controlled by using a hapten sugar. This controllability, in conjunction with newly developing glyco-technology, has great potential for the construction of arbitrary protein molecules into a regular protein aggregate, thereby providing sophisticated functions.

Animals↗
PubMed1997

A comparative study of HLA-DRB typing by transcription-mediated amplification with the hybridization protection assay (TMA/HPA) versus PCR/SSOP.

To evaluate alternative human leukocyte antigen (HLA)-DNA typing methods, we used a system of transcription-mediated amplification (TMA) with a probe hybridization protection assay (HPA) in a microtiter plate format developed by Chugai Pharmaceutics Ltd. (Tokyo, Japan) to perform intermediate-level DRB typing for 502 individual samples. Two hundred fifty-two samples submitted to our Clinical Immunogenetics Laboratory were prospectively tested concurrently with a locally developed intermediate-level DRB polymerase chain reaction/sequence-specific oligonucleotide probe (PCR/SSOP) assay in a double-blind fashion. In addition, 250 retrospective samples of archived frozen cells or DNA from clinical and research panels, previously typed by allele-level DRB1 PCR/SSOP, were chosen to include 66 distinct DRB1 alleles representing Caucasian, American Black, Asian, and Native American ethnic groups. Among the prospectively typed samples, except for four samples with a TMA/HPA microplate handling problem, a single TMA/HPA allele assignment (1/462 alleles = 0.2%) was discordant with PCR/SSOP. Among the 250 retrospective samples, a single HPA probe for codon 57 aspartic acid consistently cross-reacted with the codon 57 valine sequence of DRB1*0807. However, TMA/HPA identified six samples with previous PCR/SSOP typing errors, all of which involved identification of sequences at codons 67-71 in samples heterozygous for two DR52-associated DRB1 alleles. Assay turnaround time from sample preparation to results was 11 h for 24 samples or 6-7 h for 1-4 samples. In summary, we found the TMA/HPA DRB typing system to provide rapid, reliable, and accurate HLA-DRB typing results. The current TMA/HPA methodology could be improved by use of a molded plastic cold block to provide more consistent and secure microtiter plate cooling than the current water/ice slurry. Nevertheless, this methodology, based on a microtiter plate format but without the usual plate washing steps of the traditional ELISA, has superior potential for microplate handling and reagent distribution with a robotics system and a work surface incorporating microplate heating and cooling units.

Alleles↗
PubMed1997

Cranial polyneuropathy with elevated serum antiganglioside antibody.

We report a 6-year-old girl with cranial polyneuropathy with elevated serum levels of antiganglioside antibodies. She manifested herpetic vesicles around the right upper eyelid and mouth without antecedent infection. She developed facial asymmetry and double vision 5 days after the first appearance of the vesicles. Neurological examination on admission disclosed palsies of the bilateral sixth and twelfth cranial nerves and right third and seventh cranial nerves, but limb muscle weakness, ataxia, and areflexia were not observed. Cerebrospinal fluid examination and MRI of the brain showed no abnormalities. Serum antibodies to gangliosides GQ1b and GT1b, but not GM1, and those to Campylobacter jejuni were significantly increased on admission and on the hospital day 14. These observations suggest that the present case is a variant form of Miller Fisher syndrome or Bickerstaff's brainstem encephalitis subsequent to asymptomatic C. jejuni infection. We treated her with intravenous administration of high-dose methylprednisolone and acyclovir, but almost no effect was observed. All cranial nerve palsies, however, had resolved completely approximately 4 months later. This may be the first pediatric case in which cranial polyneuropathy and antiganglioside antibodies were associated.

Antibodies, Bacterial↗
PubMed1997

TP53 mutations in stage I gallbladder carcinoma with special attention to growth patterns.

32 stage I cases of gallbladder carcinoma (GC) were examined to evaluate TP53 mutations with special attention to growth patterns. Their growth patterns were classified into two types: polypoid (P-type) and flat (F-type). 16 cases of GC were classified as P-type and 16 as F-type. p53 immunohistochemistry was performed using a mouse monoclonal anti-p53 antibody. Mutations in exons 5-8 were examined by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) and direct sequencing. The incidence of p53 immunoreactivity was greater in the cases of F-type (11/16, 69%) than those in P-type (14/16, 25%) (P < 0.05). PCR-SSCP or direct sequencing revealed that TP53 mutations were detected in all cases positive for p53 protein. These results suggest that TP53 mutations may contribute to the carcinogenesis of the F-type GC, and than this pathway in the F-type may differ from that in the P-type GC.

Adenocarcinoma↗
PubMed1997

Protection afforded by maltosyl-beta-cyclodextrin against alpha-chymotrypsin-catalyzed hydrolysis of a luteinizing hormone-releasing hormone agonist, buserelin acetate.

PURPOSE: The present study addresses how maltosyl-beta-cyclodextrin (G2-beta-CyD) impacts upon the alpha-chymotrypsin-catalyzed hydrolysis of buserelin acetate, an agonist of luteinizing hormone-releasing hormone with emphasis upon the direct effect of G2-beta-CyD on the activity of the protease. METHODS: Kinetic and solubility studies were performed in isotonic phosphate buffer (pH 7.4) at 25 degrees C and 37 degrees C. The interaction of alpha-chymotrypsin with G2-beta-CyD in the buffer solution was examined by differential scanning calorimetry. RESULTS: G2-beta-CyD decelerated the alpha-chymotrypsin-catalyzed hydrolysis of buserelin acetate to give the 1-3 tripeptide and the 4-9 hexapeptide fragments. This deceleration can be explained solely by a non-productive encounter between a complex of the substrate with G2-beta-CyD and the protease at relatively low CyD concentrations, while the direct inhibitory effect of G2-beta-CyD on the proteolytic activity made a considerable contribution to the overall deceleration of the hydrolysis at higher CyD concentrations. Calorimetric studies indicate the presence of intermediate states in the thermal unfolding of alpha-chymotrypsin, simultaneously accompanied by the autolysis. By contrast, a two-state thermal unfolding of alpha-chymotrypsin was observed in the presence of G2-beta-CyD, suggesting reduced proteolytic activity upon binding to G2-beta-CyD. CONCLUSIONS: These results suggest that G2-beta-CyD at higher concentrations inhibits the proteolytic action of alpha-chymotrypsin through direct interaction with the protease, as well as through the formation of a non-productive complex with the substrate.

Buserelin↗
PubMed1997

Pneumomediastinum in newborns induced by the Elder CPR/demand valve during resuscitation.

Two term and one post-term newborn infants with pneumomediastinum associated with the use of an Elder CPR (cardiopulmonary resuscitation)/demand valve during resuscitation are described. Because of apnea or irregular gasping respiration after vaginal delivery, they received repetitive positive-pressure ventilation with this resuscitator, which is designed to provide 100% oxygen with a limited pressure of up to 40 cmH2O. Following resuscitation, the infants had tachypnea and diminished breath sounds. Roentgenograms and computed tomography of the chest revealed pneumomediastinum in all three and cervical subcutaneous emphysema in one. They required 25-30% oxygen for 3-14 days until they recovered spontaneously. Thus, pressures as low as 40 cmH2O can cause barotrauma, and the Elder resuscitator, even when functioning properly, may injure the lungs of newborn infants.

Asphyxia Neonatorum↗
PubMed1997

Interstitial pneumonitis probably induced by cyclophosphamide in nephrosis.

A case of interstitial shadows associated with oral cyclophosphamide therapy in a 32-month-old girl with steroid-resistant nephrotic syndrome, who was admitted to the Nishi-Kobe Medical Center with systemic edema, is reported. Due to the lack of response to prednisolone, cyclophosphamide was also administered orally at a dose of 3 mg/kg per day, 4 weeks after the start of steroid therapy. Approximately 3 weeks after the combination treatment she developed a fever, dry cough and cyanosis. Radiographic examination showed diffuse ground-glass shadow in both lungs, presumably indicating that she had interstitial pneumonitis. Her pulmonary signs and symptoms deteriorated despite various antimicrobial treatments. A discontinuation of cyclophosphamide and the administration of high-dose methylprednisolone yielded a dramatic improvement. These findings suggest that the diffuse pulmonary disease in this case was induced by cyclophosphamide. Since interstitial pneumonitis may be fatal and irreversible, attention should be paid to this rare complication even in patients undergoing low-dose oral cyclophosphamide treatment.

Alkylating Agents↗
PubMed1997

Significant decreases of ulinastatin-like immunoreactive substance in the cerebrospinal fluid of patients with dementia.

Studies to elucidate changes in the contents of ulinastatin-like immunoreactive substance (UTIRS) and alpha 1-microglobulin-like immunoreactive substance (alpha 1 MIRS) in cerebrospinal fluid (CSF) of patients with dementia were performed. Levels of UTIRS in the dementia group were significantly (p < 0.01) lower than those in dementia-free subjects. In addition, lower levels of UTIRS were registered in subjects afflicted with a higher severity of dementia. However, the levels of alpha 1 MIRS were not affected in the dementia group compared with dementia-free subjects. Neither UTIRS nor alpha 1 MIRS contents were related to the existence and stages of Parkinson's disease. These results suggest that UTIRS levels in the CSF are associated with the severity of dementia.

Aged↗
PubMed1997

Spectroscopic characterization of the inclusion complex of a luteinizing hormone-releasing hormone agonist, buserelin acetate, with dimethyl-beta-cyclodextrin.

Inclusion complexation of buserelin acetate, and agonist of luteinizing hormone-releasing hormone, with dimethyl-beta-cyclodextrin (DM-beta-CyD) in aqueous solution was studied spectroscopically and its mode of interaction was assessed. Ultraviolet absorption and circular dichroism (CD) spectroscopies indicate that the aromatic side chains of buserelin acetate, L-tryptophan and L-tyrosine residues, are incorporated into the hydrophobic environment of the DM-beta-CyD activity. Furthermore, proton and carbon-13 nuclear magnetic resonance spectroscopies suggest that in addition to the two aromatic side chains, a tertiary butyl D-serine residue is inserted into the DM-beta-CyD cavity from the secondary hydroxyl side. On the other hand, the continuous variation plots for the buserelin acetate: DM-beta-CyD system showed a 1:1 stoichiometry of the complex. Therefore, the complexation should be initiated by the inclusion of one of the three binding sites on the buserelin molecule into DM-beta-CyD, which may in turn prevent the further access of the second cyclodextrin to the other binding sites, probably due to steric hindrance and/or conformational changes of the peptide. These structural features of the complex would account for the stabilizing effect of DM-beta-CyD on the enzymatic degradation of buserelin acetate.

Buserelin↗
PubMed1997

Different patterns of DNA alterations detected by restriction landmark genomic scanning in heterogeneous prostate carcinomas.

Alterations in the genomic DNAs of six heterogeneous prostate carcinomas, as well as that of individual and histologically distinct foci within the tumors, were examined using restriction landmark genomic scanning, a method employing two-dimensional gel analysis of a large number of DNA fragments generated by digestion with highly specific endonucleases. Upon autoradiographic imaging, these fragments appear as spots of varying intensity and location specific for each sample. In our study, comparison of cancer DNAs against normal prostate DNA controls yielded alterations in at least 35 spots. Despite differences in the histological grading of tumors, 3 spots common to all tumor samples showed consistent amplification of intensity and 8 other common spots demonstrated consistent reduction of intensity when compared with control. In addition, spot alterations occurred between histologically identical foci isolated from within single tumors. We suggest that these spot changes detected in DNA profiles generated by restriction landmark genomic scanning reflect aberrations in as yet unidentified oncogenes and tumor suppressor genes and indicate that prostate cancer is not only histologically heterogeneous and multifocal but also genetically multicentric.

Aged↗
PubMed1997

Chromosome abnormality in solid and cystic tumor of the pancreas.

We report a case of a solid and cystic tumor of the pancreas with chromosomal abnormalities. The patient, a 13-yr-old girl, successfully underwent surgical excision and has been asymptomatic for more than 10 months. The tumor had two parameters suggesting malignant potential; a local invasion into a bile duct, and high mitotic activity. Chromosomal analysis showed two complex abnormalities, of which double loss of X chromosomes and trisomy for chromosome 3 were common. The complexity and polyclonality may stem from a clonal evolution. The observed abnormalities may provide a crucial clue to the understanding of the developmental process of this neoplasm.

Adolescent↗
PubMed1997

An expression profile of genes in human retina and isolation of a complementary DNA for a novel rod photoreceptor protein.

PURPOSE: To characterize expression patterns of active genes in human retina, and to isolate novel genes that are uniquely expressed in this tissue. METHODS: A 3'-directed complementary DNA (cDNA) library that faithfully represents the composition of messenger RNA (mRNA) was constructed with an mRNA preparation from a cadaveric human retina. A total of 925 3' terminal sequences were collected by sequencing randomly selected clones, of which 789 were regarded as representing chromosomally coded genes (gene signatures [GS]). GS were compared with each other and searched against GenBank. The resulting expression profile, listing gene species and their frequency, represents the composition of mRNA in the retina. By comparing this expression profile with those obtained from 10 other source cells or tissues, genes uniquely active in the retina were discovered, including some not previously described. A full-sized cDNA corresponding to one of these was isolated and sequenced. Its expression was analyzed by multitissue Northern hybridization and in situ hybridization to the retina specimen. It was then mapped on human chromosomes. RESULTS: In the expression profile, 108 genes were detected recurrently, suggesting that they are very active. Fifty-five of them were identified in GenBank, including the most abundant opsin gene and several other genes for phototransduction. Among the remaining novel and active genes, 19 were considered unique to retina on the basis of their representation status in other expression profiles and in dbEST. One of these was identified as a gene that encodes a novel secretory protein expressed in a rod photoreceptor that maps to chromosome 18p11.3. CONCLUSIONS: The expression profile of active genes in the retina represents the composition of mRNA, which reflects the relative activities of genes in this tissue. A comparison of this expression profile with those obtained with other tissues resulted in isolation of a novel cDNA specifically expressed in the rod photoreceptor. It is anticipated that additional novel genes that are uniquely active in the neural retina may be obtained with the same strategy, leading to further clarification of the biologic or physiological characteristics of this tissue.

Amino Acid Sequence↗