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K Nishida

Publications and source records attributed to K Nishida.

At least 55 records · Page 3Linked to original sources
PubMed2001

Utility of Etest in choosing appropriate agents to treat fungal keratitis.

PURPOSE: To evaluate the utility of Etest in choosing the appropriate treatment of fungal keratitis. METHODS: Etest was used to determine the drug sensitivities of isolates from the eyes of three patients with fungal keratitis, and the clinical outcomes of treatment with selected drugs were evaluated. RESULTS: In all cases, drug sensitivity demonstrated by Etest accorded with clinical efficacy of the drugs. CONCLUSION: The results in these cases suggest that evaluating drug sensitivities with Etest is an efficient means of selecting optimal pharmacotherapy for fungal keratitis.

Aged↗
PubMed2001

Different susceptibilities of postmitotic checkpoint-proficient and -deficient Balb / 3T3 cells to ICRF-193, a catalytic inhibitor of DNA topoisomerase II.

Two distinct types of Balb / 3T3 cells were isolated which exhibit either 4 N DNA or both 4 N and 8 N DNA after exposure to colcemid for 48 h. They were found to differ with respect to the postmitotic checkpoint, but not the mitotic checkpoint. Firstly, the checkpoint-proficient and -deficient cells exhibited the same accumulation and subsequent decrease in the number of mitotic cells following exposure to microtubule inhibitors. Secondly, after exit from abnormal mitosis in the presence of ICRF (Imperial Cancer Research Fund)-193, the checkpoint-proficient cells were arrested in the next cycle G1, while the checkpoint-deficient cells progressed into S and G2 phase. When either mitotic or asynchronous cells were exposed to ICRF-193, the checkpoint-proficient cells proved more sensitive to the cytotoxic effect of this agent than the checkpoint-deficient cells. The different susceptibilities of the two types of cells to ICRF-193 were not caused by variation in topoisomerase (topo) II function since both the biochemical activity of this enzyme and chromosome segregation were inhibited by similar concentrations of ICRF-193 in both checkpoint-proficient and -deficient cells. We propose that the inhibition of chromosome segregation by ICRF-193 is monitored by the next G1 checkpoint, resulting in an irreversible G1 block in the case of postmitotic checkpoint-proficient cells. As the checkpoint-deficient cells can escape this G1 block, these cells have an increased survival capacity. In summary, ICRF-193 may prove to be a very useful drug for examination of the postmitotic checkpoint.

3T3 Cells↗
PubMed2001

In vitro and in vivo activities of syn2836, syn2869, syn2903, and syn2921: new series of triazole antifungal agents.

The in vitro and in vivo activities of four azole compounds belonging to a new series of 2(2,4-difluorophenyl)-3-(4-substituted piperazin-1-yl)-1-(1,2,4-triazol-1-yl) butanol antifungal agents is described. The compounds were selected from a library of azole compounds synthesized by our group. The in vitro activities of Syn2869, Syn2836, Syn2903, and Syn2921 against a panel of over 240 recently collected clinical isolates of yeast and molds were determined, and the results were compared with those obtained with fluconazole (FLC), itraconazole (ITC), and amphotericin B (AMB). The MICs at which 90% of the isolates were inhibited (MIC(90)s) for the four test compounds for strains of Candida spp. ranged from <0.048 to 0.78 microg/ml. All compounds were also active against FLC-resistant Candida albicans and other Candida sp. strains. Moreover, MIC(90)s for strains of Cryptococcus neoformans, Aspergillus spp., Trichophyton spp., and Microsporum spp. were also low and ranged from <0.048 to 0.39 microg/ml. The test compounds produced a fungistatic pattern during the time-kill kinetic studies. In vivo studies indicated that all four test compounds have good efficacies against C. albicans in a murine systemic infection model and significantly improved the survival rates of the infected mice. The results for Syn2903 were similar to those for FLC, while the other compounds were slightly less effective but had ranges of activities similar to the range of activity of ITC. The compounds were also evaluated against an Aspergillus fumigatus systemic infection. Syn2903 was also superior to ITC, whereas the efficacy data for the other compounds were similar to those for ITC. It was concluded from the data generated for this new series of azole compounds in the studies described above that further pharmacokinetic and toxicologic evaluations are warranted prior to selection of a candidate compound for preclinical testing.

Animals↗
PubMed2001

Tissue-specific autoregulation of the stat3 gene and its role in interleukin-6-induced survival signals in T cells.

Signal transducer and activator of transcription 3 (STAT3) mediates signals of various growth factors and cytokines, including interleukin-6 (IL-6). In certain IL-6-responsive cell lines, the stat3 gene is autoregulated by STAT3 through a composite IL-6 response element in its promoter that contains a STAT3-binding element (SBE) and a cyclic AMP-responsive element. To reveal the nature and roles of the stat3 autoregulation in vivo, we generated mice that harbor a mutation in the SBE (stat3(mSBE)). The intact SBE was crucial for IL-6-induced stat3 gene activation in the spleen, especially in the red pulp region, the kidney, and both mature and immature T lymphocytes. The SBE was not required, however, for IL-6-induced stat3 gene activation in hepatocytes. T lymphocytes from the stat3(mSBE/mSBE) mice were more susceptible to apoptosis despite the presence of IL-6 than those from wild-type mice. Consistent with this, IL-6-dependent activation of the Pim-1 and junB genes, direct target genes for STAT3, was attenuated in T lymphocytes of the stat3(mSBE/mSBE) mice. Thus, the tissue-specific autoregulation of the stat3 gene operates in vivo and plays a role in IL-6-induced antiapoptotic signaling in T cells.

Animals↗
PubMed2001

Comparative FISH mapping of Gab1 and Gab2 genes in human, mouse and rat.

Gab1 and Gab2 are members of the Gab family which act as adapters for transmitting various signals in response to stimuli through cytokine and growth factor receptors, and T- and B-cell antigen receptors. We determined chromosome locations of the two genes in human, mouse and rat by fluorescence in situ hybridization. The Gab1 gene was localized to chromosome 4q31.1 in human, 8C3 in mouse and 19q11.1--> q11.2 in rat, and the Gab2 gene was located on chromosome 11q13.4-->q13.5 in human, 7E2 in mouse and 1q33.2-->q33.3 in rat. All human, mouse and rat Gab1 and Gab2 genes were localized to chromosome regions where conserved homology has been identified among the three species.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Sustained ocular delivery of tilisolol to rabbits after topical administration or intravitreal injection of lipophilic prodrug incorporated in liposomes.

To improve the retention time of tilisolol in the precorneal area or vitreous body, we prepared liposomes incorporating the O-palmitoyl prodrug of tilisolol. O-Palmitoyl tilisolol was completely incorporated in the liposomes. After topical administration of O-palmitoyl tilisolol liposomes to the rabbit eye, O-palmitoyl tilisolol rapidly disappeared from the tear fluid. The inclusion of 2% carmellose sodium slightly prolonged the retention of O-palmitoyl tilisolol in the tear fluid. After intravitreal injection of O-palmitoyl tilisolol liposomes, there was a relatively prolonged retention of O-palmitoyl tilisolol in the vitreous body. At 24 and 48 h after intravitreal injection of O-palmitoyl tilisolol liposomes, the tilisolol concentration in the vitreous body was significantly higher compared with the concentration after intravitreal injection of tilisolol liposomes.

Administration, Topical↗
PubMed2001

Effect of instillation method on the absorption of phenolsulphonphthalein as a model drug from the liver and small intestinal serosal surface in rats.

We have examined the effect of the instillation method on the absorption of a drug from the liver and the small intestinal serosal surface in rats. We performed continuous microinstillation via an infusion pump and bolus instillation via a syringe, using phenolsulphonphthalein (phenol red) as the model drug. After continuous microinstillation of phenolsulphonphthalein 2.35 mg in 235 microL for 5 min on the liver and small intestinal serosal surface in rats, the AUC (area under the curve) of the plasma concentration profile up to 60 min was significantly higher compared with bolus instillation. A similar trend was observed after continuous microinstillation of phenolsulphonphthalein 2.35 mg in 117.5 microL for 2.5 min. The calculated absorption rate constants (Ka) after continuous microinstillation of phenolsulphonphthalein based on a two-compartment model with first-order absorption were higher than those after bolus instillation on the liver and small intestinal serosal surface at either instillation concentration. Moreover, Ka was increased after continuous microinstillation of 2.35 mg in 117.5 microL at either instillation site. Instillation of phenolsulphonphthalein on the liver surface resulted in a 1.2- to 2.3-fold higher Ka compared with the small intestinal serosal surface. This tendency was marked after continuous microinstillation of 2.35 mg in 117.5 microL. In conclusion, absorption could be enhanced by instilling a small amount of drug solution on the liver surface gradually and continuously, suggesting a promising approach for instillation site-selective drug delivery in the peritoneal cavity.

Algorithms↗
PubMed2001

Spectral characteristics of human atrial fibrillation waves of the right atrial free wall with respect to the duration of atrial fibrillation and effect of class I antiarrhythmic drugs.

The aim of this study was to use fast Fourier transform analysis to clarify the characteristics of human atrial fibrillation (AF) waves with respect to the duration of AF and the effect of class I antiarrhythmic drugs. Twenty-two patients (10 paroxysmal AF, 12 persistent AF) without organic heart disease were studied by conventional electrophysiological methods. Electrograms were recorded from the right atrial free wall during AF and spectral analysis was performed for 35s (16 consecutive 4096-ms epochs with 50% overlap) and the fibrillation cycle length (FCL) was calculated from the peak frequency. Mean FCL and SD were determined from 16-epoch data, and the temporal variability of FCL was defined as the SD of FCL. Paroxysmal AF had a longer mean FCL than persistent AF (178+/-26ms vs 139+/-16 ms, p<0.001) and AF duration had a significant inverse correlation with mean FCL (r=-0.79, p<0.001). The temporal variability of FCL was significantly greater in paroxysmal AF than in persistent AF (p<0.05) and there was a significant positive correlation between the mean FCL and the temporal variability of FCL (r=0.66, p<0.001). In 8 of 18 patients given a class I antiarrhythmic drug (cibenzoline or procainamide), AF was terminated and in those patients the mean FCLs before administration of class I drugs were significantly greater than in patients without AF termination. With respect to mean FCL before drug administration, conversion occurred in 100% of patients with FCL > or =168 ms and in 17% of those with FCL <168 ms. A longer duration of AF shortens the mean FCL, which is consistent with atrial electrical remodeling. Class I drugs prolong the mean FCL above a critical level and will terminate AF, which can be estimated from the mean FCL before drug administration.

Adult↗
PubMed2001

Spontaneous onset of torsade de pointes in long-QT syndrome and the role of sympathovagal imbalance.

The net effects of sympathetic and vagal activity on the QT interval and the mode of spontaneous onset of torsade de pointes (TdP) are still unclear in long-QT syndrome. Two patients with long-QT syndrome had syncope while undergoing Holter ECG investigation. The spontaneous onset of TdP in these patients was analyzed with respect to the relation between the RR and QT intervals. Both patients were high-school students (16- and 17-year-old boys) who had been diagnosed as long-QT syndrome and followed up without medical treatment because they had had neither a history of syncope nor arrhythmia induction by treadmill exercise tests. The first episode of syncope in both patients occurred during ordinary daily life and was not related to exercise or psychological stress. The dynamic changes between the RR and QT intervals associated with the spontaneous onset of TdP were analyzed by Holter ECG. Both patients showed sinus tachycardia followed by abrupt sinus bradycardia immediately before the onset of TdP. The enhanced rate of the adaptive response of the QT interval that occurred during the deceleration of the heart rate preceded the onset of TdP. These observations suggest that the complex situation that follows sympathovagal imbalance may have an important role in the dynamic change in the QT interval and initiation of TdP in patients with long-QT syndrome.

Adolescent↗
PubMed2001

Isolation of chlamydia psittaci from domestic cats with oculonasal discharge in Japan.

Eight strains of Chlamydia psittaci were isolated in Japan from the nasal and conjunctival swabs of six household cats using the L929 cell line of mouse fibroblast origin. The isolates were identified as C. psittaci on the basis of the formation of characteristic inclusion bodies in the cell culture detected by Giemsa stain and immunofluorescence. Comparison of nucleotide sequences of the ompA gene amplified from the three isolates with the published sequence of feline FEPN strain of C. psittaci showed almost 100% homology.

Animals↗
PubMed2001

Expression of caspase-3 and -9 relevant to cartilage destruction and chondrocyte apoptosis in human osteoarthritic cartilage.

To clarify the involvement of the caspase family in the pathway of NO-induced chondrocyte apoptosis, osteoarthritis (OA) cartilage obtained from 8 patients undergoing total hip arthroplasty were used for histopathological study. Cartilage samples taken from non-fibrillated areas of femoral head resected during surgery for femoral neck fracture were used for comparison. DNA fragmentation of chondrocytes was detected by the nick end-labeling (TUNEL) method. Apoptosis was further confirmed by transmission electron microscopy. The distributions of nitrotyrosine (NT), caspase-3, and -9 were examined immunohistochemically. The populations of apoptotic as well as NT-, caspase-3-, and -9-positive cells were quantified by counting the number of cells in the superficial, middle, and deep layers, respectively. The TUNEL-positive cells were observed primarily in superficial proliferating chondrocytes, clustering chondrocytes, and deep-layer chondrocytes of OA cartilage. Few positive cells were seen in the proliferating chondrocytes in the middle layer. Positive reactions for caspase-3 and -9 were observed in chondrocytes in similar areas. Histological OA grade showed significant correlations with the mean populations of apoptotic chondrocytes (% apoptosis) over the 3 areas. The populations of NT-positive cells (% NT) over the same areas also showed significant correlation with OA grade. Positivity for caspase-3 closely correlated with the OA grade, % apoptosis and %NT. It was concluded that caspase-3 and -9 could play a role in NO-induced chondrocyte apoptosis in OA cartilage.

Aged↗
PubMed2001

Elevated expression of transglutaminase 1 and keratinization-related proteins in conjunctiva in severe ocular surface disease.

PURPOSE: In severe ocular surface diseases, pathologic keratinization of the ordinarily nonkeratinized corneal and conjunctival mucosal epithelia results in severe visual loss. The expression in conjunctivalized corneas of various proteins known to play important roles in the physiological keratinization process in human epidermis was examined to better understand the mechanism of keratinization. METHODS: Conjunctiva covering the cornea was examined in 12 eyes with ocular surface disease in the chronic cicatricial phase. These comprised four Stevens-Johnson syndrome, four ocular cicatricial pemphigoid, and four chemical injuries. Normal conjunctivas from four age-matched individuals served as controls. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate transglutaminase 1 gene expression and immunohistochemistry to study the expression of transglutaminase 1 protein along with other keratinization-related proteins (involucrin, loricrin, filaggrin, and cytokeratins 1 and 10) and cytokeratin pairs 4/13 and 3/12. RESULTS: Semiquantitative RT-PCR showed that transglutaminase 1 mRNA expression was upregulated in keratinized conjunctiva compared with normal. Also, in this tissue, immunohistochemistry demonstrated elevated levels of transglutaminase 1, involucrin, filaggrin, and the cytokeratin pair 1/10. Levels of loricrin and cytokeratin pairs 4/13 and 3/12, however, remained the same. CONCLUSIONS: Various keratinization-related proteins, transglutaminase 1 included, are most likely involved in the pathogenesis of cicatrizing ocular surface diseases.

Adult↗
PubMed2001

MCP-1 receptor binding affinity is up-regulated by pre-stimulation with MCP-1 in an actin polymerization-dependent manner.

Monocyte chemoattractant protein-1 (MCP-1) induces monocyte chemotaxis via interaction with the MCP-1 receptor CCR2. We found that MCP-1 binding to monocytic THP-1 cells was increased by pre-treatment with MCP-1. The amount of CCR2 mRNA and the cell-surface expression of CCR2 were not affected by MCP-1 stimuli. In contrast, the MCP-1-treated THP-1 cells showed a sixfold increase in MCP-1 binding affinity compared with untreated cells. MCP-1 binding to CCR2B-transfected HEK-293 cells was also enhanced by pre-treatment with MCP-1, and MCP-1 binding affinity increased by sixfold. In both cell lines, the enhancement of MCP-1 binding by stimulation with MCP-1 was blocked by cytochalasin D, an inhibitor of actin polymerization. This effect of pre-treatment with MCP-1 is insensitive to pertussis toxin and partially blocked by U73122, an inhibitor of phospholipase C. These results demonstrate that the MCP-1 receptor binding affinity is up-regulated by MCP-1 stimuli in an actin polymerization-dependent manner.

Actins↗
PubMed2001

The effect of TGF-beta1 on differential gene expression profiles in human corneal epithelium studied by cDNA expression array.

PURPOSE: TGF-betas regulate cell proliferation and differentiation, and they play important roles in maintenance of corneal epithelium. However, the precise function of TGF-betas in the corneal epithelium remains unclear. In this study, cDNA expression array technology was used to demonstrate the effect of TGF-beta1 on the simultaneous expression of a large number of genes in cultured human corneal epithelial cells (HCECs). The change in protein level expression of the specific genes influenced by TGF-beta1 was also investigated. METHODS: Human cDNA expression array technology was used to study the simultaneous expression of 1176 specific cellular genes in HCECs incubated with TGF-beta1 (10 ng/ml). Moreover, gene-specific semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to confirm the gene expression pattern measured by the cDNA expression array. Western blot analysis was used to examine protein expression of the specific genes in the presence or absence of TGF-beta1. RESULTS: TGF-beta1 significantly upregulated the expression of 19 genes and significantly downregulated ras-related protein, caspase10, and beta4-integrin in the treated HCECs. The expression of 277 genes including alpha3-integrin, PAI-2, transferrin receptor, and cyclin-D1 was studied. Semiquantitative RT-PCR analysis confirmed the TGF-beta1-mediated changes in expression patterns of these genes. Furthermore, Western blot analysis revealed that TGF-beta1 remarkably decreased PAI-2, transferrin receptor, and integrin alpha3, and increased caspase10 on the protein level. CONCLUSIONS: TGF-beta1 regulates the expression of specific types of genes in HCECs. These results strongly suggest that TGF-beta1 is critically involved in the maintenance of the corneal epithelium through the control of a network of various signal-transduction pathways.

Blotting, Western↗
PubMed2000

Prognostic value of genetically diagnosed lymph node micrometastasis in non-small cell lung carcinoma cases.

The predictive value of lymph node micrometastasis, detected by immunohistochemical or genetic methods, is well appreciated in terms of prognosis. However, a major problem is high false-positive rates, because most methods focus on cytokeratin, which is a component not only of carcinoma but also normal epithelial and nonepithelial cells. Mutant allele-specific amplification (MASA) can detect DNAs derived from cancer cells itself, reportedly with high sensitivity. It was, therefore, used with nested-PCR using p53 or K-ras mutation for analysis of lymph node micrometastasis in non-small cell lung carcinoma (NSCLC) patients in the present study, in comparison with the immunohistochemical method using an anti-cytokeratin reagent for the same samples. Lymph nodes from 31 NSCLC patients with p53 and K-ras mutated tumors (30 and 1, respectively) staged as pathological (p)-T1-4 N0-1 and M0 were examined. Genetic and immunohistochemical methods demonstrated positive reactions in 34 (15%) and 61 (27%) of 229 lymph nodes, respectively (9 cases, 29%, and 24 cases, 77%). The concordance with the two methods was 77%, but 13 (39%) of 34 genetically positive lymph nodes could not be detected by immunohistochemistry (IHC). Of 22 cases with p-N0 disease, 6 (27%) were genetically positive in hilar and/or mediastinal lymph nodes, and 4 (67%) of them died after cancer relapse. In contrast, none of the patients without micrometastasis died of cancer (P < 0.001, log rank analysis). Of the same p-N0 patients, 17 (77%) were positive by IHC, and 4 (24%) of them died of cancer, whereas 5 negative patients did not suffer cancer relapse. Survival did not significantly differ between cases positive and negative (P = 0.246) by IHC. According to the g-N (N factor restaged by a genetic method), patients with g-N1 and g-N2 disease had a shorter survival than those with g-N0 disease (P = 0.042 and P < 0.001, respectively). However, no significant difference was observed with grading by IHC. Thus, detection of micrometastasis in regional lymph nodes with the MASA method, in other words with a carcinoma-specific marker, is of greater prognostic significance for early stage NSCLC patients than immunohistochemical results. This approach should facilitate selection of patients for whom postoperative adjuvant chemotherapy should be performed.

Adenocarcinoma↗
PubMed2000

Human intervertebral disc cells are genetically modifiable by adenovirus-mediated gene transfer: implications for the clinical management of intervertebral disc disorders.

STUDY DESIGN: Human intervertebral disc cells were cultured in monolayer and treated with adenovirus-containing marker genes to determine the susceptibility of the cells to adenovirus-mediated gene transfer. OBJECTIVES: To test the efficacy of the adenovirus-mediated gene transfer technique for transferring exogenous genes to human intervertebral disc cells in vitro. SUMMARY OF BACKGROUND DATA: Upregulated proteoglycan synthesis after direct in vivo adenovirus-mediated transfer of growth factor genes to the rabbit intervertebral disc has previously been reported. Before contemplating extending this approach to the treatment of human disc disease, it is necessary to demonstrate that human intervertebral disc cells are indeed susceptible to adenovirus-mediated gene transduction. METHODS: Human intervertebral disc cells were isolated from disc tissue obtained from 15 patients during surgical disc procedures. The cells were cultured in monolayer and treated with saline containing five different doses of adenovirus carrying the lacZ gene (Ad/CMV-lacZ), saline containing adenovirus carrying the luciferase gene (Ad/CMV-luciferase), or saline alone. Transgene expression was analyzed by 5-bromo-4-chloro-3-indolyl-beta-galactosidase (X-Gal) staining and luciferase assay. RESULTS: Adenovirus efficiently transferred lacZ and luciferase marker genes to cells from degenerated discs as well as to cells from nondegenerated discs. A minimum dose of 150 MOI Ad/CMV-lacZ was found to be sufficient to achieve transduction of approximately 100% of disc cells-regardless of patient age, sex, surgical indication, disc level, and degeneration grade. No statistically significant difference in the luciferase activities could be detected in disc cell cultures from degenerated and nondegenerated discs treated with Ad/CMV-luciferase. CONCLUSIONS: In vitro transducibility of human intervertebral disc cells by adenovirus is relatively insensitive to disc degeneration grade. Because the rate-limiting step for successful gene therapy is the ability to transfer genes efficiently to the target tissue, the achievement of efficient gene transfer to human intervertebral disc cells(using a direct, adenovirus-mediated approach) is an important and necessary step in the development of gene therapy strategies for the management of human intervertebral disc disorders.

Adenoviridae↗