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Biomedical subjects

K Okubo

Publications and source records attributed to K Okubo.

At least 109 records · Page 6Linked to original sources
PubMed1999

Cytotoxicity and microbicidal activity of electrolyzed strong acid water and acidic hypochlorite solution under isotonic conditions.

The cytotoxic effects of electrolyzed strong acid water and acidic hypochlorite solution, as well as these solutions after isotonization, against cultivated L cells were compared along with their microbicidal activities. Isotonization was accompanied by a reduction in the cytotoxic effects of these solutions against L cells. Microbicidal activity was also reduced somewhat but was still retained after isotonization. No difference was observed in these properties between these antiseptic solutions. The results obtained indicate that acidic hypochlorite solution may be useful as well as acidic electrolyzed water.

Animals↗
PubMed1999

Screening for aetiology of thrombophilia: a high prevalence of protein S abnormality.

We systematically screened for the aetiology of thrombophilia in 115 patients with venous, arterial and small vessel thromboses. Forty-one patients (36% of those we examined) suffering from a variety of thromboses, including deep vein thrombosis, pulmonary embolism, arterial occlusion, cerebral infarction, Moyamoya disease and ulcerative colitis, were characterized either with positive lupus anticoagulants or with decreased activities of protein S, protein C, antithrombin III and/or plasminogen. Eight mutation sites were confirmed in 11 thrombotic patients using gene analysis. Decreased protein S activity was found with a high incidence (23 out of 115) in Japanese patients who suffered from not only venous thrombosis but also arterial and small vessel thrombosis. We emphasize here the important role of protein S in the pathogenesis of thrombosis in the Japanese population.

Adolescent↗
PubMed1999

Adhesive explant culture of allergic nasal mucosa: effect of emedastine difumarate, an anti-allergic drug.

Allergic reaction of the nose comprises of an immediate and a late reaction. To evaluate nasal allergic reactions, many experiments have been performed by investigators. In this study, we performed a new tissue culture technique (adhesive explant culture) to analyze the migration of cells into the culture medium from the cultured allergic nasal mucosa in response to an allergen. Basophilic cells (mast cells and basophils) and eosinophils, which were released into the culture medium after the allergen challenge, were evaluated by the analysis of histamine and eosinophil cationic protein (ECP) content in the culture medium. Histamine and basophilic cells in the culture medium were more abundant in the immediate phase (within 30 min) after challenge than in the late phase (from 30 min to 10 hr). On the other hand, ECP and eosinophils in the culture medium were more abundant in the late phase than in the immediate phase. The increase of histamine content in both phases were not inhibited by pre-treatment of emedastine difumarate (EME), an anti-allergic drug. However, the increase of ECP in the late phase was inhibited by pre-treatment with EME. Moreover, the number of EG2-positive cells was also decreased by pre-treatment with EME. These results suggest that EME might lower the activation of eosinophils in the late phase of the allergic reaction. The present study also indicates that this adhesive explant culture system is useful model for studying the cellular allergic responses to drugs ex vivo.

Anti-Allergic Agents↗
PubMed1999

Isolation of pure human mucosal epithelium for RNA analysis.

Techniques for isolating the desired cell populations from complex tissues are essential for characterizing cells through mRNA analysis. We established a procedure for isolating pure mucosal epithelium from the human alimentary tract. To do this, we made rotating hooks that hold mucosal strips and detach the epithelial sheets from the irregular mucosae surface in medium containing EDTA. An additional step using a cell strainer was required to reduce contamination by lymphoid cells. Sheets of epithelial cells were detached successfully from mucosal samples derived from five different parts of the human alimentary tract. Contamination by lymphoid cells or fibroblasts was monitored by competitive RT-PCR and was no more than 0.5% of the total cells. Total RNA yields were 12.5-17 micrograms for each separation, and the integrity of the RNA was as good as that of RNAs extracted from mucosa immediately after resection. In conclusion, our method permits isolation of RNAs from a pure population of epithelial cells that can be used for mRNA-based gene expression analyses.

Cell Separation↗
PubMed1999

[Role of endothelium-derived hyperpolarizing factor in insulin-induced vasodilation in rat mesenteric artery].

Endothelium-derived hyperpolarizing factor (EDHF) as a factor in blood pressure regulation has received attention recently. However, its role in insulin-induced vasodilation is not clear. We investigated the mechanism of vasodilation induced by insulin in vitro using mesenteric arteries isolated from normotensive rats. The 2nd branch of the mesenteric artery was isolated from male Sprague-Dawley rats (12-14 weeks old), mounted on microcannules in a chamber and perfused with Krebs solution. The diameter of this segment was measured continuously with a video system under the following conditions: intraluminal insulin administration (10 and 100 mU/ml) with and without pretreatment by denudation, N omega-methyl-L-arginine methyl ester (L-NAME), indomethacin, tetrabuthylammonium (TBA, non-specific Ca2+ activated K channel blocker), charybdotoxin (ChTx, large-conductance Ca2+ activated K channel blocker), apaminn (small-conductance Ca2+ activated K channel blocker) or Na+/k(+)-ATPase blocker (ouabain). Insulin treatment induced dose-dependent vasodilation. The effects of insulin were significantly suppressed by denudation, TBA, apamin, and ChTx. L-NAME, indomethacin and ouabain did not influence the insulin-induced vasodilation. Results suggested that insulin dilates small arteries by activating the Ca2+ activated K channel.

Animals↗
PubMed1998

Cloning and developmental expression of the murine homolog of doublecortin.

While analyzing active genes in neonatal mouse hippocampus by quantitative 3'-cDNA collection, we identified a highly conserved murine homolog of doublecortin, the causative gene of X-linked lissencephaly (XLIS) and subcortical laminar heterotopia (SCLH) syndrome. The m-doublecortin cDNA contains nearly 8 kb 3' UTR homologous to hs-doublecortin and it was mapped to the X chromosome. The expression of m-doublecortin is limited to the developing CNS, especially the cortical plate, supporting that XLIS/SCLH syndrome is associated with an arrest of neuronal migration in the cerebral cortex. The m-doublecortin mRNA was absent in the ventricular zone where neuronal precursors proliferate, and interestingly it was found in various brain structures that are not typically affected in patients with this syndrome.

Amino Acid Sequence↗
PubMed1998

A mesangium-predominant gene, megsin, is a new serpin upregulated in IgA nephropathy.

Mesangial cells play an important role in maintaining a structure and function of the glomerulus and in the pathogenesis of glomerular diseases. To identify a specific gene expressed in human mesangial cells, we used a rapid large-scale DNA sequencing and computerized data processing to compare the transcripts in cultured human mesangial cells with various different cells and organs. Using this novel approach, we discovered a new mesangium-predominant gene termed "megsin." We obtained a full-length cDNA clone of megsin, which coded for a novel 380-amino acid protein. Amino acid homology search revealed that megsin belonged to the serpin (serine protease inhibitor) superfamily. The amino acid sequences in the reactive loop site of megsin showed characteristic features of functional serpins. Northern blot and reverse-transcribed PCR analyses of various tissues and cells demonstrated that megsin was predominantly expressed in human mesangial cells. In situ hybridization studies showed the megsin expression in the mesangium of normal glomeruli, while it increased in the expanded mesangium of glomeruli from patients with IgA nephropathy with the degree of mesangial proliferation. Here we report a new human mesangium-predominant gene that may function as an inhibitory serpin in normal and abnormal biological processes of glomerulus.

Amino Acid Sequence↗
PubMed1998

Expression profile of active genes in granulocytes.

A number of genes active in granulocytes have been intensively studied as to the function of their products and their expression controls. However, the intensities and relative order of these gene activities have not been studied. This report describes an expression profile of 748 different species of active genes in human peripheral granulocytes obtained by analyzing a 3'-directed cDNA library that faithfully represents the mRNA population in the source cells. A significant fraction (20.3% of the total) of the expressed genes in granulocytes consisted of nuclear proteins such as DNA binding proteins, of secretory proteins such as cytokines, and of membrane proteins such as major histocompatibility complex (MHC) proteins and receptors. By comparing this expression profile with 11 profiles similarly obtained with unrelated human cells/tissues, we discovered 10 novel genes that are likely to act specifically in granulocytes. Comparison of this expression profile with that obtained with granulocytoids widely used as a granulocyte model by inducing a cultured promyelocytic leukemia cell line HL60 showed similarities and dissimilarities of gene expressions.

Adult↗
PubMed1998

A novel SCG10-related gene uniquely expressed in the nervous system.

We have isolated a novel cDNA (HiAT3: hippocampus abundant transcript 3) in the course of screening for genes that are preferentially expressed in neonatal mouse hippocampus using random 3'-directed cDNA sequencing approach. It encodes a 180-aa protein that has high similarity to SCG10, a neuron-specific negative regulator of microtubule dynamics during neurite outgrowth. The expression of HiAT3 is limited to neurons and peaks about 1 week after birth. The identification of HiAT3 suggests that there may be an elaborate destabilizing regulation for microtubule dynamics in neurons in addition to the stabilizing effect of multiple microtubule-associated proteins (MAPs).

Amino Acid Sequence↗
PubMed1998

Identification of a novel gene marker specific for epithelial cells by utilizing a 3'-directed cDNA library.

To achieve reliability of molecular diagnosis using reverse transcription-PCR (RT-PCR), we established a unique method to search for a novel gene marker specific for colonic epithelial cells. Of eight candidate genes selected from a 3'-directed cDNA library in colonic mucosa, two genes were expressed in normal mucosa and cancer of the colon but not in either normal lymph node or normal liver tissue. Known sequences of these genes were reported to be located in the 3' noncoding region, and an additional sequence just upstream to gs04094 (one of the candidate genes) was determined. According to the newly identified sequence, we designed a new set of primers so that we could distinguish the DNA fragment amplified in RT-PCR from that in genomic PCR. RT-PCR using these primers demonstrated that gs04094 was expressed in all of 10 primary colon cancers and 4 liver metastases from colon cancer but in none of 5 normal lymph nodes, 10 peripheral blood samples, and 2 normal liver tissues. Sensitivity of this method was so high as to detect gs04094 mRNA in 10(-6) microg of colon cancer RNA per 1 microg of normal lymph node RNA. Thus, our strategy to search for a novel gene marker using 3'-directed cDNA library proved to be highly efficient.

Animals↗
PubMed1998

Oguchi disease with sectoral retinitis pigmentosa harboring adenine deletion at position 1147 in the arrestin gene.

PURPOSE: To report a Japanese patient with Oguchi disease and sectoral retinitis pigmentosa harboring a homozygous adenine deletion at position 1147 (1147delA) in the arrestin gene. METHOD: Case report. RESULTS: In both eyes, golden discoloration with Mizuo-Nakamura phenomenon and tapetoretinal degeneration of the fundus were exhibited. Electroretinography showed abnormal a-wave and absent b-wave. The presence of 1147delA in the arrestin gene was demonstrated. CONCLUSIONS: Our case provides further evidence of the close association of 1147delA in the arrestin gene in Japanese patients with Oguchi disease. Coexpression of both phenotypes of Oguchi disease and retinitis pigmentosa may suggest the possible involvement of additional defects of genes encoding the phototransduction proteins.

Adenine↗
PubMed1998

Interstitial laser coagulation for management of benign prostatic hyperplasia: a Japanese experience.

PURPOSE: The principle of interstitial laser coagulation is to shrink the prostate by generating intraprostatic necrosis without damaging the urethra or causing tissue sloughing. The clinical efficacy and durability of interstitial laser coagulation in the treatment of benign prostatic hyperplasia (BPH) were evaluated. MATERIALS AND METHODS: From December 1993 to June 1996, 76 patients with symptomatic BPH were treated with interstitial laser coagulation. A neodymium:YAG laser was used in combination with a specially designed interstitial thermotherapy light guide. The tip of the light guide was inserted into each lobe of the prostate transurethrally under direct vision. All evaluations were made at baseline and then 1, 3, 6 and 12 months after therapy. Treatment outcome was evaluated by International Prostate Symptom Score (I-PSS), flow rate and post-void residual urine volume. Disease specific quality of life was assessed via a quality of life assessment score and a BPH impact index. Independent of symptom assessment, a self-reporting questionnaire was prepared at 3 months postoperatively regarding satisfaction with treatment and sexual function. RESULTS: Among 44 patients followed to 12 months the mean I-PSS significantly decreased from 20.4 at baseline to 7.4, representing 64% improvement (p <0.001). Peak flow rate increased by 50% from a preoperative average of 7.4 to 11.1 ml. per second at 12 months in 42 patients (p <0.001). The post-void residual volume decreased by 57% from 102 to 44 ml. at 12 months in 40 cases (p <0.001). Steady and progressive improvement was observed on quality of life assessment and BPH impact index scores at 3, 6 and 12 months. No patients reported new onset of erectile dysfunction. No serious side effects were observed, except for loss of ejaculation in 3 cases and seminal vesicle abscess in 1. Only 6 patients (8%) required re-treatment for persisting obstructive symptoms during 12 months of followup. A recent change in methods towards more aggressive treatment plausibly influenced the outcomes to require less repeat treatment. CONCLUSIONS: After the interstitial laser coagulation procedure satisfactory results were obtained and improvement lasted through 12 months. Although the optimal number of fiber placements for each prostate is not known, more aggressive treatment appears to provide better outcomes.

Aged↗
PubMed1998

Functional quantitative analysis of the genome in cultured human mesangial cells. Technical note.

For normal physiological function, each cell tightly regulates gene expression in a specific fashion so that critical proteins are synthesized in a well-coordinated manner. Therefore, it is very important to uncover which genes are expressed in specific cells. Recent technological advances combined with rapid large-scale DNA sequencing and computerized data processing have allowed us to investigate the expression levels of a variety of transcripts in the mesangial cells, a target of injury in many forms of glomerulonephritis. Utilizing a large scale sequencing of a 3'-directed cDNA library, which allows us to avoid variable cloning efficiencies reflecting the size of cDNA, we investigated expression profiles of various molecules in cultured human mesangial cells. Among the 1,193 sequenced clones, 688 (57.7%) appeared more than once (redundant sequence group), representing 203 different species. Thirty-nine of these appeared more than three times. The most abundant mRNA was that of fibronectin, which consisted of 3.9% of the total mRNA population. Except for mitochondrial or ribosomal genes, calcyclin came next (2.5%), followed by two cytoskeletal genes, gamma-actin gene and calpactin 1 light chain gene, in addition to an amyloid precursor protein homolog (0.7%). In conclusion, we performed a molecular biological quantification of transcripts in mesangial cells. Fibronectin was the most abundantly expressed, followed by calcyclin, gamma-actin, calpactin 1 light chain, and an amyloid precursor protein homolog. We also discovered some candidate genes specific for human mesangial cells. The expression profile of the transcripts serves as an important tool in understanding the biological properties of mesangial cells.

Actins↗
PubMed1998

Isolation of genes identified in mouse renal proximal tubule by comparing different gene expression profiles.

An expression profile is a list based on a large scale sequencing of 1000 cDNA clones, showing the expressed genes and the abundance of their transcripts in a given cell or tissue (Okubo K et al: Nature Genet 2:173, 1992). We constructed an expression profile of mouse renal proximal tubules (PT) carefully isolated by microdissection in order to characterize its gene expression. Altogether 1000 clones were analyzed; there were 646 types of transcripts in PT, among which 196 were identical or homologous to the previously reported genes. The most abundant transcript was kidney-androgen regulated protein. By comparing the expression profile of PT with those obtained from other sources, several genes were identified only in PT. They included known transcripts and transcripts that were not homologous to the known genes. Three (GS4001, 3991, and 4059) of the non-homologous genes were analyzed by Northern blotting and in situ hybridization, and GS4001 and 4059 were predominantly expressed in the kidney, whereas GS3991 was detected in the liver as well as in the kidney. The sequence analysis of the full-size cDNAs demonstrated that GS4001 was a new member of aspartic proteinases and GS4059 was a novel gene. It also revealed that GS3991 was a mouse homologue of SA gene known to be expressed in PT. The expression profile of mouse PT and its comparison with those of other tissues and cells provide an alternate way of isolating genes predominantly expressed in PT, and also provides probes to study the molecular mechanisms of gene expression in the kidney.

3T3 Cells↗
PubMed1998

Value of the free to total prostate specific antigen ratio and prostate specific antigen density for detecting prostate cancer in Japanese patients.

BACKGROUND: This study evaluated the free to total serum prostate specific antigen (f/t PSA) ratio and prostate specific antigen density (PSAD) in detecting prostate cancer in Japanese males with a PSA level between 2.5 and 20.0 ng/mL in a community-based urology practice. METHODS: Twenty-six patients with clinically localized prostate cancer and 44 patients with histologically-proven benign prostatic hyperplasia (BPH) were studied. The serum levels of free PSA (fPSA) and total (t) PSA were determined using a chemiluminescent enzyme immunoassay. The f/t PSA ratio was calculated by dividing the fPSA value by the total PSA value and was compared with the PSA and PSAD via the receiver operating characteristic (ROC) curves. RESULTS: Patients with prostate cancer had a significantly lower f/t PSA ratio than patients with BPH. The PSAD was a superiordiagnostic tool over PSA (P< 0.01) when analyzed by ROC curves. The f/t PSA ratio was also superior to PSA, but lacked significance (P=0.12), and similarly, the PSAD was superior, but not significant, to the f/t PSA ratio. Using a cut-off value of 0.19, the PSAD had a sensitivity of 81% and a specificity of 82%. With a cut-off value of 14.0%, the f/t PSA ratio had a sensitivity of 81% and a specificity of 66%. CONCLUSION: This study showed that PSAD alone improved cancer detection significantly better than PSA. However, it is still unclear whether the f/t PSA ratio is superior to PSA or PSAD in the discrimination between BPH and prostate cancer in Japanese male patients.

Aged↗