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Biomedical subjects

K Nishida

Publications and source records attributed to K Nishida.

At least 91 records · Page 5Linked to original sources
PubMed2000

Characterization of immediate early genes expressed in chlorovirus infection.

By Southern blot analysis of restriction fragments of a chlorovirus CVK2 genomic contig with probes of RNA expressed immediate early in infection, sixteen genes were specifically found to be expressed in the host cells. These genes include those for aminoacyl-tRNA synthetase, nucleolin, ribosomal protein S5, hyaluronan synthase, TFIID etc. All of these transcripts were polyadenylated and most likely expressed in the host nucleus. The structural characteristics of these genes are discussed in connection with their expression mechanism. The biological importance of the gene products in viral infection are also considered.

Chlorella↗
PubMed2000

Potential applications of gene therapy to the treatment of intervertebral disc disorders.

Gene therapy involves the transfer of genes to cells such that the recipient cells express these genes and thereby synthesize the ribonucleic acid and protein that they encode. Recent investigations suggest that gene therapy may have potential applications in the treatment of intervertebral disc disorders, particularly those associated with disc degeneration. The successful in vivo transfer of therapeutic genes to target cells within the intervertebral disc in clinically relevant animal models is one example of the rapid progress that is being made. The purpose of the current review is to address several important technical issues, including choice of vectors and gene delivery strategy and the characteristics of the target tissues, which are relevant to future clinical applications of gene therapy for the treatment of intervertebral disc disorders. It already is apparent from the growing literature that gene therapy has the potential of becoming a valuable clinical treatment mode for intervertebral disc disorders in the twenty-first century.

Adenoviridae↗
PubMed2000

Epithelial barrier function and ultrastructure of gelatinous drop-like corneal dystrophy.

PURPOSE: Recently, mutations in the M1S1 gene have been identified as responsible for gelatinous drop-like corneal dystrophy (GDLD). How the abnormal M1S1 gene product causes GDLD is not known, although evidence suggests that it may compromise corneal epithelial function. This investigation attempted to determine the effect of the abnormal M1S1 gene product by assessing epithelial barrier function and epithelial ultrastructure in GDLD corneas. METHODS: Epithelial barrier function was assessed on the basis of fluorescein uptake. The method used a modified slit-lamp fluorophotometer. High-resolution scanning electron and atomic force microscopy was used to investigate the amyloid deposits and epithelial cell structure. RESULTS: Epithelial permeability was orders of magnitude higher in GDLD corneas than normal. The structure of the amyloid deposits was characterized, and clear abnormalities in epithelial morphology and cell junctions were observed. CONCLUSIONS: The high epithelial permeability observed in GDLD corneas was directly correlated with abnormalities in epithelial structure, including irregular cell junctions. This suggests that the abnormal M1S1 gene product may affect epithelial cell junctions resulting in increased cell permeability in GDLD corneas.

Adult↗
PubMed2000

BodyMap: a collection of 3' ESTs for analysis of human gene expression information.

BodyMap is a collection of site-directed 3' expressed sequence tags (ESTs) (gene signatures, GSs) that contains the transcript compositions of various human tissues and was the first systematic effort to acquire gene expression data. For the construction of BodyMap, cDNA libraries were made, preserving abundance information and histologic resolutions of tissue mRNAs. By sequencing 164,000 randomly selected clones, 88,587 GSs that represent chromosomally coded transcripts have been collected from 51 human organs and tissues. They were clustered into 18,722 independent 3' termini from transcripts, and more than 3000 of these were not found among ESTs assembled in UniGene (Build 75). Assessment of the prevalence of polyadenylation signals and comparison with GenBank cDNAs indicated that there was no significant contamination by internally primed cDNAs or genomic fragments but that there was a relatively high incidence (12%) of alternative polyadenylation sites. We evaluated the sensitivity and resolution of expression information in BodyMap by in silico Northern hybridization and selection of tissue-specific gene probes. BodyMap is a unique resource for estimation of the absolute abundance of transcripts and selection of gene probes for efficient hybridization-based gene expression profiling.

3' Untranslated Regions↗
PubMed2000

Ultra-small-angle neutron scattering studies on phase separation of poly(vinyl alcohol) gels

Time-resolved light scattering measurements during the gelation process of a poly(vinyl alcohol) (PVA) solution in a mixture of dimethyl sulfoxide and water (H2O) have shown that a spinodal decomposition (SD) type phase separation takes place in the early stage of gelation. In this case the kinetics of SD is valid only before macroscopic gelation occurs because the growth rate is slowed down by gelation. Such SD type phase separation makes the solution opaque as it proceeds, and hence the structural change can no longer be followed by light scattering. To investigate the structure of the opaque PVA gel as well, we have employed an ultra-small-angle neutron scattering technique using a Bonse-Hart camera. These observations reveal that even after the macroscopic gelation the structure due to the microphase separation on a spatial scale of several &mgr;m continues to grow against the elasticity. This may be because at first the gel structure is too soft to suppress the growth of the microphase separation, but within 24 h after the quenching the growth terminates. On the basis of the results, we will discuss a possible mechanism of the microphase separation after gelation.

Journal Article↗
PubMed2000

Further evidence of spinodal decomposition during the induction period of polymer crystallization: time-resolved small-angle x-ray scattering prior to crystallization of poly(ethylene naphthalate)

Aiming to clarify spinodal decomposition of polymers in the induction period of crystallization, time-resolved small-angle x-ray scattering measurements have been made in situ for poly(ethylene naphthalate) while it was crystallized from the glass, or in the case of the so-called glass crystallization. It is confirmed for this polymer that in the very beginning of the induction period a scattering peak appears at around 0.03 A (-1) in scattering vector q, which corresponds to a characteristic wavelength of 200 A in density fluctuations, and grows with time. Time evolution of this scattering peak is described by the kinetics of the spinodal decomposition as previously reported for the glass crystallization of poly(ethylene terephthalate).

Journal Article↗
PubMed2000

Three new regions on chromosome 17p13.3 distal to p53 with possible tumor suppressor gene involvement in lung cancer.

We investigated loss of heterozygosity (LOH) at the distal portion of the p53 gene on the short arm of chromosome 17 in lung cancers in order to search for new tumor suppressor genes. The roles of the putative genes were also studied in terms of pathological features. One hundred and forty-five resected non-small cell lung cancers were examined for LOH using 11 markers mapped on, and distal to the p53 locus, and deletion maps were constructed. Four commonly deleted regions were found: one from TP53 to ENO3, where the p53 gene resides, and three others from ENO3 to D17S1566, D17S379 to D17S1574 and distal to ABR, with LOH frequencies almost the same as, or higher than, at the TP53 locus. Examination of the relationship between LOH of the latter three regions and histopathological parameters of adenocarcinomas (genetically negative for p53 mutation) revealed allelic losses on D17S379 to be associated with advanced lesions, while D17S513 was more frequently deleted in poorly differentiated tumors. These results indicate that new tumor suppressor gene(s) may reside on these three distinctly deleted regions on chromosome 17p13.3 distal to the p53 gene in lung cancer, with possible roles in progression and differentiation of adenocarcinomas.

Adenocarcinoma↗
PubMed2000

Role of Gab1 in heart, placenta, and skin development and growth factor- and cytokine-induced extracellular signal-regulated kinase mitogen-activated protein kinase activation.

Gab1 is a member of the Gab/DOS (Daughter of Sevenless) family of adapter molecules, which contain a pleckstrin homology (PH) domain and potential binding sites for SH2 and SH3 domains. Gab1 is tyrosine phosphorylated upon stimulation of various cytokines, growth factors, and antigen receptors in cell lines and interacts with signaling molecules, such as SHP-2 and phosphatidylinositol 3-kinase, although its biological roles have not yet been established. To reveal the functions of Gab1 in vivo, we generated mice lacking Gab1 by gene targeting. Gab1-deficient embryos died in utero and displayed developmental defects in the heart, placenta, and skin, which were similar to phenotypes observed in mice lacking signals of the hepatocyte growth factor/scatter factor, platelet-derived growth factor, and epidermal growth factor pathways. Consistent with these observations, extracellular signal-regulated kinase mitogen-activated protein (ERK MAP) kinases were activated at much lower levels in cells from Gab1-deficient embryos in response to these growth factors or to stimulation of the cytokine receptor gp130. These results indicate that Gab1 is a common player in a broad range of growth factor and cytokine signaling pathways linking ERK MAP kinase activation.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Conjunctival inflammation in the chronic phase of Stevens-Johnson syndrome.

AIMS: To understand the immunopathogenesis of the corneal conjunctivalisation in Stevens-Johnson syndrome. METHODS: Conjunctivalised corneas from five patients with Stevens-Johnson syndrome were studied immunohistochemically for several cell surface antigens and two cytokines. Chemical injury specimens were also studied. RESULTS: In all cases, immunohistochemistry revealed LFA-1, CD4, CD8, and CD68 on subepithelial infiltrating cells. Also, HLA-DR and ICAM-1 were found on the surfaces of epithelial cells, subepithelial infiltrating cells, subepithelial fibroblasts, and endothelial cells in blood vessels. IFN-gamma was found in basal epithelial cells; subepithelial cells and subepithelial extracellular matrix CD19 and IL4 were not detected. CONCLUSIONS: The infiltrating cell population in the Stevens-Johnson syndrome samples includes macrophages, CD4 positive T cells, and CD8 positive T cells. The cytokine expression pattern suggests CD4 positive T cells are Th1 cells. The infiltrating cell population is similar in Stevens-Johnson syndrome and chemical injury conjunctivalised corneas.

Adult↗
PubMed2000

Capacity for epithelial differentiation in synovial sarcoma: analysis of a new human cell line.

AIM: To analyse the capacity for epithelial differentiation in synovial sarcoma using a new human cell line. METHODS: A new human cell line, KU-SS-1, was established from a monophasic, spindle cell type of synovial sarcoma by grafting those cells on to severe combined immunodeficient (SCID) mice and then transferring them to in vitro culture systems. The KU-SS-1 cells were characterised by light and electron microscopy, and by immunohistochemical, flow cytometric, and cytogenetic analysis. RESULTS: Primary tumour and cultured cells at passage 20 showed a positive reaction for vimentin, which is a mesenchymal marker. After 40 passages, subcultured cells were injected into SCID mice to induce further tumours. These advanced subcultured cells and the tumour cells that they induced were positive for cytokeratin, an epithelial marker, and exhibited epithelial ultrastructural features such as intermediate junctions. Furthermore, two colour immunofluorescent analysis for proliferating nuclear cell antigen (PCNA) and intermediate filaments showed that a large number of PCNA expressing cells were positive for vimentin, and that part of this fraction also expressed cytokeratin. The existence of cells with reactivity for these three markers indicated that, in this cell line, a fraction with high proliferating capacity had both mesenchymal and epithelial markers. In addition, cytogenetically, this cell line expressed the SYT-SSX chimaeric transcript as a result of the t(X;18) (p11;q11) translocation. CONCLUSIONS: A human synovial sarcoma cell line was established and stably maintained in cell culture for more than 70 passages. In addition, this cell line showed epithelial differentiation, which supports the hypothesis that synovial sarcoma is a carcinosarcoma like tumour with true epithelial differentiation. This cell line will be a useful tool for investigating the nature of this tumour and will contribute to clinical studies.

Adult↗
PubMed2000

Pharmacokinetic prediction of the ocular absorption of an instilled drug with ophthalmic viscous vehicle.

We previously developed an in vivo pharmacokinetic model that accounts for the corneal diffusion in albino rabbits and predicts the concentration of beta-blockers in the anterior segments. The purpose of this study is to pharmacokinetically predict the ocular absorption and characterize the systemic absorption of instilled drug with ophthalmic viscous vehicle to assist in its design and evaluation. Tilisolol and carboxymethylcellulose sodium salt (CMC) were used as the model ophthalmic drug and viscous polymer, respectively. After instillation of tilisolol with CMC vehicle in rabbits, the disposition of the drug in tear fluid, aqueous humor, and plasma were determined by HPLC. The ocular and systemic absorption were analyzed by a mathematical model including a diffusion process and a two-compartment model with first-order absorption, respectively. CMC vehicle increased the area under the concentration-time curve (AUC) of tilisolol in the tear fluid and aqueous humor and slightly reduced the AUC in plasma. The concentrations of tilisolol in the aqueous humor after instillation with CMC vehicle were accurately predicted from the tear concentrations by using the in vivo ocular pharmacokinetic model. CMC vehicle improved the ocular delivery of tilisolol.

Absorption↗
PubMed2000

Modification of ocular permeability of peptide drugs by absorption promoters.

The purpose of this study was to investigate the effect of absorption promoters on the ocular membrane permeability of thyrotropin-releasing hormone (TRH) and luteinizing hormone-releasing hormone (LHRH) as model peptides. The permeabilities of TRH and LHRH were measured using a two-chamber glass diffusion cell mounted with isolated ocular membranes of albino rabbits. Saponin, EDTA, benzalkonium chloride and paraben were used as absorption promoters. These promoters enhanced the permeability of hydrophilic molecules through the cornea and conjunctiva. The promoting effects of the absorption promoters on the conjunctival drug penetrations were not as strong as those on the corneal penetrations. The different responses of the corneal and conjunctival drug penetrations to these promoters may be useful in controlling the extent and pathway of the ocular and systemic absorptions of instilled drugs. The promotional effects of absorption promoters on the corneal drug penetration apparently increased with an increase in penetrant molecular weights, although those on the conjunctival drug penetrations did not depend on the molecular weights.

Absorption↗
PubMed2000

Increased osteocyte apoptosis during the development of femoral head osteonecrosis in spontaneously hypertensive rats.

We investigated the presence of osteocyte apoptosis in the necrotic trabeculae of the femoral head of spontaneously hypertensive rat (SHR) using the in situ nick end labeling (TUNEL) method and transmission electron microscopy. The occurrence of osteonecrosis and ossification disturbance was significantly higher in SHR compared with Wistar Kyoto (WKY) rats, and Wistar (WT) rats used as control animals (P < 0.01). A high population of TUNEL positive osteocytes was detected mainly in 10- and 15-week-old SHRs. Sectioned examination of the femoral head of SHRs and WKY rats by electron microscopy revealed apoptotic cell appearances such as aggregation of chromatin particles and lipid formation. In contrast, a positive reaction was significantly lower in osteocytes in the femoral heads of WT rats (P < 0.01). Our results indicate that apoptosis forms an important component of the global pathologic process affecting the femoral head of SHR, which leads to osteonecrosis in this region.

Animals↗
PubMed2000

[A case of percutaneous and transpapillary placements of expandable metallic stents in a patient with cholangiocarcinoma at the hilum of the liver].

A 76-year-old woman was admitted with obstructive jaundice. US and MR cholangiopancreatography (MRCP) revealed an inoperative cholangiocarcinoma, 3 cm in diameter at the hilum of the liver, the obstruction of the hepatic duct bifurcation and the separation of bilateral hepatic bile ducts. Percutaneous transhepatic biliary drainage (PTBD) was performed from bilateral hepatic bile ducts. The right PTBD tube was spontaneously extubated. We could not succeed in performing internal biliary drainage across the hilar malignant stricture from a left hepatic bile duct, because of bad angulation. Transpapillary insertion into the common bile duct (CBD) was extremely difficult due to the collapse of the CBD. Endoscopic sphincterotomy (EST) after precutting method was performed. Although we performed the ballooned dilatation of malignant stricture and the insertion of a self-expandable metallic stent (EMS) into a right hepatic bile duct transpapillary. After dilatation of the hilar malignant stricture by the initial EMS, we inserted a guidewire into the CBD through the wire mesh of a stent from the left PTBD tube. We could insert the second EMS from a left hepatic bile duct to the CBD transhepatically, using a dilator and a dilating balloon. Finally, we performed the ballooned dilatation from bilateral hepatic bile ducts to the CBD transpapillary. She was discharged after bilateral internal biliary drainages, successfully.

Aged↗
PubMed2000

[Midazolam-atropine lollipop for pediatric premedication].

Strawberry flavored sweet lollipop containing midazolam (5 mg) and atropine (0.25 mg) was evaluated for the premedication of pediatric patients as judged by sedative and anti-anxious effects and gastric fluid volume and acidity. The subjects of this prospective, double blind, random and controlled study were 175 children aged between 6 months and 10 years. They were divided into three groups: group A patients receiving the lollipop containing only 5 mg midazolam (n = 78), group B patients receiving the lollipop containing only 0.25 mg atropine (n = 21), and group C patients receiving the lollipop containing 5 mg midazolam and 0.25 mg atropine (n = 76). The plasma midazolam concentration was measured in ten children in group A. The sedative and anti-anxious effects were scaled with four levels. The children receiving the lollipop containing midazolam (group A and C) showed a better level of the sedative and anti-anxious state. The volume of gastric fluid of group A was more than those of group B and C. The pH of group A gastric fluid was also higher than those of other groups. The correlation equation of the plasma midazolam concentration (y ng.ml-1) against time (t min) was y = 149 x e(-t/64), (r = 0.775). These results suggest that midazolam-atropine lollipop is one of the favorable choices as the premedication for pediatric patients.

Adjuvants, Anesthesia↗
PubMed1999

Modulation of the biologic activity of the rabbit intervertebral disc by gene therapy: an in vivo study of adenovirus-mediated transfer of the human transforming growth factor beta 1 encoding gene.

STUDY DESIGN: In vivo studies using a rabbit model to determine the biologic effects of direct, adenovirus-mediated transfer of a therapeutic gene to the intervertebral disc. OBJECTIVES: 1) To deliver an exogenous therapeutic gene to rabbit lumbar intervertebral discs in vivo, 2) to quantify the resulting amount of gene expression, and 3) to determine the effect on the biologic activity of the discs. SUMMARY OF BACKGROUND DATA: Although growth factors such as transforming growth factor beta 1 appear to have promising therapeutic properties, there currently is no practical method for sustained delivery of exogenous growth factors to the disc for the management of certain chronic types of disease (e.g., disc degeneration). A possible solution is to modify the disc cells genetically through gene transfer such that the cells manufacture the desired growth factors endogenously on a continuous basis. METHODS: Saline, with or without virus, was injected directly into lumbar discs of 22 skeletally mature female New Zealand white rabbits. Group 1 (n = 11) received the adenovirus construct Ad/CMV-hTGF beta 1 containing the therapeutic human transforming growth factor beta 1-encoding gene. Group 2 (n = 6) received adenovirus containing the luciferase marker gene. Group 3 (n = 5) received saline only. The rabbits were killed 1 week after injection. Immunohistochemical staining for human transforming growth factor beta 1 was performed on the disc tissues of one rabbit from Group 1. Nucleus pulposus tissues from the remaining rabbits were cultured in serumless medium. Bioassays were performed to determine human transforming growth factor beta 1 production and proteoglycan synthesis. RESULTS: Discs injected with Ad/CMV-hTGF beta 1 exhibited extensive and intense positive immunostaining for transforming growth factor beta 1. The nucleus pulposus tissues from the discs injected with Ad/CMV-hTGF beta 1 exhibited a 30-fold increase in active transforming growth factor beta 1 production, and a 5-fold increase in total (active + latent) transforming growth factor beta 1 production over that from intact control discs (P < 0.05). Furthermore, these tissues exhibited a 100% increase in proteoglycan synthesis compared with intact control tissue, which was statistically significant (P < 0.05). CONCLUSIONS: The results of this study suggest that the intervertebral disc is an appropriate site for adenovirus-mediated transfer of exogenous genes and subsequent production of therapeutic growth factors. Gene therapy therefore may have useful applications for study of the basic science of the intervertebral disc and for clinical management of degenerative disc disease.

Adenoviridae↗
PubMed1999

Preventive effect of Oren-gedoku-to (Huanglian-Jie-Du-Tang) extract on the development of stress-induced acute gastric mucosal lesions in rats.

The preventive effect of Oren-gedoku-to (Huanglian-Jie-Du-Tang) extract (TJ-15), a traditional Chinese herbal medicine for the therapies of gastric ulcers and gastritis, on the development of stress-induced acute gastric mucosal lesions was examined in rats with water immersion restraint (WIR) stress. Simultaneous p.o. administration of TJ-15 at a dose of 20, 100 or 250 mg/kg prevented dose-dependently gastric mucosal lesion development in rats subjected to WIR stress over a 6-h period. In the gastric mucosa of rats with WIR stress alone, lipid peroxide concentration and xanthine oxidase (XOD) and myeloperoxidase--an index of neutrophil infiltration--activities increased with lesion development, while nonprotein SH concentration decreased. The simultaneous administration of TJ-15 attenuated all these changes with gastric mucosal lesion development in a dose-dependent manner. These results indicate that simultaneously administered TJ-15 exerts a preventive effect on the development of WIR stress-induced acute gastric lesions in rats, and suggest that the preventive effect of TJ-15 could be due to its preventive actions on enhanced sulfhydryl oxidation and lipid peroxidation via oxygen free radicals generated by the xanthine-xanthine oxidase system and infiltrated neutrophils in the gastric mucosa and on neutrophil infiltration into the tissue.

Animals↗