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Biomedical subjects

Y Kano

Publications and source records attributed to Y Kano.

At least 73 records · Page 4Linked to original sources
PubMed1998

Cellular and molecular dynamics in exercise-induced urticarial vasculitis lesions.

BACKGROUND: Based on the histologic findings of fully developed lesions, leukocytoclastic vasculitis has been regarded as the histologic criterion for differentiating urticarial vasculitis from urticaria. Nevertheless, because the early lesions have not been examined histologically, the key biological events leading to the development of leukocytoclastic vasculitis remain unknown. To address this issue, urticarial vasculitis lesions induced by physical exercise were sequentially examined histologically and immunohistochemically in a patient over the course of 24 hours. Serum levels of various cytokines also were determined in parallel. OBSERVATIONS: At 3 hours after exercise challenge, the number of identifiable mast cells decreased and the first cell type that appeared around the vessels was the eosinophil. The serum tumor necrosis factor alpha level was strikingly increased as compared with that before challenge. Intense expression of E-selectin was also induced at 3 hours. The deposition of eosinophil peroxidase was observed at 3 hours and reached maximum deposition at 10 hours. The eosinophil peroxidase deposits preceded the prominent influx of neutrophils and the subsequent deposits of neutrophil elastase. CONCLUSION: The extracellular deposition of eosinophil granule proteins, in addition to the deposition of immune complexes and a variety of cytokines from the infiltrating cells, appears to be one of the key biological events that determines whether urticarial lesions resolve without causing vasculitis or develop into vasculitis.

Antigen-Antibody Complex↗
PubMed1998

In vitro schedule-dependent interaction between paclitaxel and SN-38 (the active metabolite of irinotecan) in human carcinoma cell lines.

Paclitaxel and irinotecan are important new anticancer agents. The combination of these two agents has been considered for use against a variety of advanced solid tumors. Since the schedule-dependent effects of this combination may be crucial to its use, we studied the interaction of paclitaxel and SN-38 (the active metabolite of irinotecan) in various schedules in four human cancer cell lines in culture. Cell growth inhibition after 5 days was determined using an MTT assay. The effects of drug combinations at the IC80 level were analyzed by the isobologram method. Simultaneous exposure to paclitaxel and SN-38 for 24 h produced antagonistic (subadditive and protective) effects in the human lung cancer cell line A549, the breast cancer cell line MCF7, and the colon cancer cell line WiDr, and produced additive effects in the ovarian cancer cell line PA1. Sequential exposure to paclitaxel for 24 h followed by SN-38 for 24 h, and the reverse sequence, produced additive effects in all four cell lines. These findings suggest that sequential administration, not simultaneous administration, may be the appropriate schedule for the therapeutic combination of paclitaxel and irinotecan. Continued preclinical and clinical studies should provide further insights and assist in determining the optimal schedule for this combination in clinical use.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Improvement of lichen nitidus after topical dinitrochlorobenzene application.

Recently, a relationship between immunologic alterations and the development of lichen nitidus (LN) lesions has been described. We treated LN lesions with topical dinitrochlorobenzene (DNCB) application in a patient with peripheral CD4+ T lymphocytopenia. After 4 months, the eruption cleared. We investigated histologically and immunohistochemically biopsy specimens obtained before and after treatment. Our result suggests that local alterations of the pattern of cells and cytokines by topical DNCB application could have contributed to the resolution of the LN lesions.

Administration, Topical↗
PubMed1998

Novel cephalosporin derivatives possessing a bicyclic heterocycle at the 3-position. Part II: Synthesis and antibacterial activity of 3-(5-methylthiazolo[4,5-c]pyridinium-2-yl)-thiomethylcephalosporin derivatives and related compounds.

A series of cephalosporin derivatives with a thiazolopyridinium group at the 3-position was synthesized and evaluated for antibacterial activity. Some of these cephalosporin derivatives having a (5-alkylthiazolo[4,5-c]pyridinium-2-yl)thiomethyl group at the 3-position showed strong activity against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa. Among them, 5a showed a good antibacterial spectrum in vitro, and also showed a similar or slightly superior activity to that of ceftazidime in vivo against P. aeruginosa.

Animals↗
PubMed1998

Augmentation of the antitumor effect of adoptive immunotherapy by in vivo sensitization of EL-4 lymphoma and pre-treatment with sizofiran.

The antitumor effects of adoptive immunotherapy using LAK cells treated with sizofiran (SPG) following in vivo antigen sensitization with EL-4 lymphoma (EsLAK), comparing nonsensitized LAK cells (sLAK), were studied in mice with intraperitoneal implantation of EL-4 lymphoma. EL-4 cells treated with Mitomycin C (100 micrograms/ml) were introduced by inoculation into the peritoneum of C57BL/6 mice for antigen sensitization. Four days later, SPG (100 micrograms) was intramuscularly injected. Three days after SPG administration, mononuclear cells obtained from the spleen were prepared for LAK cells (EsLAK). The following results were obtained: 1) The survival period was significantly greater in the sLAK and EsLAK groups than in the control group. The survival period in the EsLAK group was significantly greater than that in the sLAK group. 2) The number of EL-4 cells in the peritoneal exudate cells 11 days postimplantation was lowest in the EsLAK group, and the number of lymphocytes including LGL was largest in the EsLAK group, compared with the sLAK group and the control group. 3) The EsLAK cells showed significantly more enhanced cytotoxic activity against EL-4 than the sLAK cells. 4) Histopathological findings of metastatic lesions of the liver and spleen stained by HE 11 days postimplantation showed less infiltrating tumor cells and more lymphocytic infiltrations in the sLAK and EsLAK groups compared with the control group. These results suggest that induction of LAK cells by administration of SPG to lymphocytes treated by in vivo sensitization with tumor antigen increases the efficacy of adoptive immunotherapy.

Adjuvants, Immunologic↗
PubMed1998

Construction of a bovine yeast artificial chromosome (YAC) library.

We have constructed a bovine yeast artificial chromosome (YAC) library to provide a common resource for bovine genome research. We used leukocytes of a Japanese black bull (Bos taurus) as the DNA source, AB1380 for the yeast host, and pYAC4 for the vector. The library consists of 24,576 clones arranged in 256 96-well microtiter plates. An average insert size estimated from the analysis of 251 randomly selected clones was 480 kb. The rate of chimeric YACs evaluated by fluorescence in situ hybridization (FISH) analysis of 44 randomly selected clones was 36.4%. To estimate the number of genome equivalents, PCR-based screening was performed with 48 primer pairs and isolated 3.2 clones on average. In order to provide broad access for the scientific community, this library has been incorporated into the Reference Library system which provides high density filters for colony hybridization screening and a common database of the library.

Animals↗
PubMed1998

Tourette syndrome in Japan: a nationwide questionnaire survey of psychiatrists and pediatricians.

In order to shed light on the clinical picture of patients with Tourette syndrome (TS) treated at medical institutions in Japan, a nationwide survey covering both pediatric patients and psychiatric patients was conducted. We mailed 316 questionnaires on experience in treating TS cases and the patients' present conditions etc. to specialists such as psychiatrists and pediatricians. A total of 164 responded. The survey found 154 TS patients being treated at the time of survey, 45 (29.2%) had obsessive-compulsive symptoms (OCS), and 10 (6.5%) had family histories of TS. It was suggested that TS is often associated with OCS and that familial cases of TS are slightly less common in Japan than they are in the USA. Of the 116 respondents who described their experiences, 85 (73.2%) said that they had treated one or more patients displaying the symptoms of frequent coprolalia, and 42 (36.2%) said that they had treated one or more patients suffering from developmental disorders. Based on these findings, we speculated that the rate of coprolalia in Japan is a little higher than the previously reported 4% and that TS is often associated with developmental disorders.

Adolescent↗
PubMed1998

Isolation and contraction of the stress fiber.

Stress fibers were isolated from cultured human foreskin fibroblasts and bovine endothelial cells, and their contraction was demonstrated in vitro. Cells in culture dishes were first treated with a low-ionic-strength extraction solution and then further extracted using detergents. With gentle washes by pipetting, the nucleus and the apical part of cells were removed. The material on the culture dish was scraped, and the freed material was forced through a hypodermic needle and fractionated by sucrose gradient centrifugation. Isolated, free-floating stress fibers stained brightly with fluorescently labeled phalloidin. When stained with anti-alpha-actinin or anti-myosin, isolated stress fibers showed banded staining patterns. By electron microscopy, they consisted of bundles of microfilaments, and electron-dense areas were associated with them in a semiperiodic manner. By negative staining, isolated stress fibers often exhibited gentle twisting of microfilament bundles. Focal adhesion-associated proteins were also detected in the isolated stress fiber by both immunocytochemical and biochemical means. In the presence of Mg-ATP, isolated stress fibers shortened, on the average, to 23% of the initial length. The maximum velocity of shortening was several micrometers per second. Polystyrene beads on shortening isolated stress fibers rotated, indicating spiral contraction of stress fibers. Myosin regulatory light chain phosphorylation was detected in contracting stress fibers, and a myosin light chain kinase inhibitor, KT5926, inhibited isolated stress fiber contraction. Our study demonstrates that stress fibers can be isolated with no apparent loss of morphological features and that they are truly contractile organelle.

Actin Cytoskeleton↗
PubMed1998

Clinical characteristics of Tourette syndrome.

The aim of the present study was to examine the clinical characteristics of Tourette syndrome (TS) in terms of symptomatology, outcome and organic and genetic factors, and to compare these with results of previous studies on TS in Western countries and in Japan, on the basis of precise information taken from a large number of TS patients under psychiatric treatment in Japan. There was a total of 64 TS patients (55 males and nine females) selected from those who visited our outpatient clinic from 1974 to 1993 and were found to meet the criteria for Tourette's disorder of DSM-III-R. The mean patient age at entry to the present study was 17.4 years (SD: 7.2). All data were collected through a systematic chart review of subjects, including data on tic symptoms and the course of their development; complications and developmental histories; family histories; medical and psychological examinations; treatment; severity and outcome. A check of the data showed that the mean age at onset was 6.9 years (SD: 2.7). An analysis of the progression of the symptoms revealed that 'generalized tics' afflicting the entire body were found in 64.1% of subjects and coprolalia was found in 50%. The main complications were obsessive-compulsive symptoms (OCS) in 62.5% of patients and attention deficit hyperactivity disorder (ADHD) in 17.2%. Of their parents, 7.0% had tic disorders except TS and 1.6% had TS. Contrary to results from previous studies of TS, our study revealed that at least the incidence of coprolalia in TS patients in Japan is not lower than in Western countries. However, the frequency of familial cases seemed to be lower than previously reported for Western patients. Outcome was fairly related with 'generalized tics,' OCS, aggressiveness and ADHD.

Adolescent↗
PubMed1998

Effect of aphidicolin on DNA methyltransferase in the nucleus.

Methylation of cytosine in the genomic DNA plays an important role in mammalian embryogenesis. DNA methyltransferase activity, which contributes mainly to the maintenance of the methylation pattern during proliferation, is under the control of the cell cycle, its activity being higher in the S phase than in the other phases (Adams, R.L.P., 1990, Biochem. J. 265, 309-320). In the present study, we examined how DNA methyltransferase is regulated in the cells arrested at S phase by aphidicolin treatment. The activity and protein levels of DNA methyltransferase in the nuclei were kept constant in proliferating mouse erythroleukemia cells, and increased about twofold after 6 h incubation in the presence of aphidicolin. This increase of DNA methyltransferase levels by aphidicolin treatment was positively correlated with the cell population at S phase. De novo synthesis of DNA methyltransferase protein was increased by the treatment. In addition, the relative half life of pulse labeled DNA methyltransferase was prolonged by aphidicolin treatment. Both increase in synthesis and prolongation of half life of DNA methyltransferase in S phase contributed to the increase of the activity and the protein levels by aphidicolin treatment. Prolongation of half life was abolished by cycloheximide, suggesting that newly synthesized protein(s) with a short half life participated in the degradation of DNA methyltransferase.

Animals↗
PubMed1998

Pharmacological properties of traditional medicines. XXIV. Classification of antiasthmatics based on constitutional predispositions.

It is commonly accepted that bronchial asthma or rhinitis accompanies disorders in body fluids and body temperature. The effects of ephedrine and the traditional antiasthmatics "Makyo-kanseki-to" and "Goko-to" were therefore studied on such constitutional predispositions as insensible perspiration and body temperature. Ephedrine markedly increased body temperature and exhibited a strong increased action on respiratory insensible perspiration, whereas Makyo-kanseki-to and Goko-to not only prevented the elevation of body temperature, but also increased respiratory insensible perspiration following the reduction of non-evaporative heat loss from the body surface. Thus, the diagnostic criteria of these two medicines used to treat hot-type asthma or dry cough were experimentally determined. The results also suggest that there is a great possibility that the administration of antiasthmatics may elicit side effects or make diseases worse unless their actions on constitutional predispositions are taken into account, such as body temperature and body fluids.

Amygdalin↗
PubMed1998

A new experimental device for the measurement of moisture emission and heat release from respiratory organs and body surface.

A new experimental device was developed to investigate respiratory diseases. The moisture and heat released from respiratory organs and the body surface of a rat were determined by means of this device as well as the rectal temperature. The high recovery of results was statistically confirmed, and the measured values at various environmental temperatures were significantly different from each other. Some standard drugs, such as ephedrine, aminophylline and chlorpromazine, were examined. Their stimulant or depressant actions were clearly observed. The results of some traditional medicines for the treatment of rhinitis and bronchial asthma from this measuring system were consistent with their clinical applications. These results suggest that this new experimental system is not only effective in the experimental understanding of cold-hot syndrome, but also contributes to the evaluation of the effects of traditional medicines.

Animals↗
PubMed1998

Schedule-dependent synergism and antagonism between paclitaxel and methotrexate in human carcinoma cell lines.

Paclitaxel and methotrexate are active against a variety of solid tumors. Because of differences in their mechanisms of action and toxicity profiles, the combination of these two agents has clinical potential. Clinical studies of this combination are in progress. We studied the optimal schedule of paclitaxel and methotrexate in combination at various schedules in vitro using human lung cancer A549, breast cancer MCF7, ovarian cancer PA1, and colon cancer WiDr cells. Cells were simultaneously exposed to paclitaxel and methotrexate for 24 h and sequentially exposed to paclitaxel for 24 h followed by methotrexate for 24 h or vice versa. Cell growth inhibition after 5 days was determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of drug combinations at the concentration of drug that produced 80% cell growth inhibition (the IC80 level) were analyzed by the isobologram method. The simultaneous exposure to paclitaxel and methotrexate produced additive to antagonistic effects in the A549 and PA1 cells, and antagonistic effects in the MCF7 and WiDr cells. The sequential exposure to paclitaxel followed by methotrexate produced additive effects in all four cell lines. The reverse sequence produced synergistic effects in the A549, MCF7, and WiDr cells, and additive effects in the PA1 cells. These findings suggest that a sequential administration of methotrexate followed by paclitaxel may be the appropriate schedule for this combination. On the basis of the observed in vitro synergism, further in vivo and clinical studies are necessary to clarify the toxicity and proposed antitumor effects of this schedule.

Antineoplastic Agents, Phytogenic↗
PubMed1997

Heat shock-induced excessive relaxation of DNA in Escherichia coli mutants lacking the histone-like protein HU.

Plasmid DNA in exponentially growing Escherichia coli immediately relaxes after heat shock but the relaxed DNA re-supercoils rapidly, the despite continued presence of the heat shock conditions. We have now obtained genetic evidence indicating that the histone-like protein HU of E. coli is required for this re-supercoiling of DNA. Plasmid DNA in a hupA-hupB double gene-disruption mutant relaxed excessively after heat shock, while the relaxation of DNA in a himA-himD double gene-disruption mutant and in an hns insertion mutant was transient, thereby indicating that HU protein, but not IHF or H-NS proteins, is required for the re-supercoiling of DNA. Exposure of the hupA-hupB double mutant to a temperature of 50 degrees C led to both excessive relaxation of DNA and to a decrease in viable cell number but temperatures lower than 46 degrees C did not lead to these events. Based on these results, we propose that HU protein maintains the negative supercoiling of DNA during thermal stress and contributes to cellular thermotolerance in E. coli.

Bacterial Proteins↗
PubMed1997

Construction and characterization of a rad51rad52 double mutant as a host for YAC libraries.

RAD52 or RAD51 recombination-deficient yeast strains stabilize otherwise unstable YACs containing ribosomal DNA or the human color vision locus (Kohno et al., 1994). Thus the RAD52RAD51 pathways(s) are apparently involved in the instability of YACs containing tandem repeat loci, presumably by promoting recombination-based deletion formation. Some other genomic loci are still unstable or unrecoverable in those strains, but we now find that greater stability is observed in a rad51rad52 double mutant strain that we have newly constructed. YACs containing a highly unstable region around DXS49 or centromeric regions throw off a variety of products in single mutants, but are much more stable in the rad51rad52 strain, which could therefore provide a better host for library construction and maintenance.

Chromosomes, Artificial, Yeast↗
PubMed1997

Morphological adaptation of capillary network in compensatory hypertrophied rat plantaris muscle.

The aim of this study was to examine the morphological adaptation of the capillary network in hypertrophied plantaris muscles by examining both capillary numbers and luminal circumferences. Hypertrophy of the plantaris muscle was induced by myectomy of the gastrocnemius muscle. This hypertrophy was characterised by increases in muscle mass and fibre cross-sectional area. All capillary parameters were determined using morphometric methods in perfusion-fixed plantaris muscle. Increased capillary-to-fibre ratio was observed in the overloaded plantaris muscle while no change was observed in the capillary luminal circumference. No differences were observed in the capillary density and the capillary-to-fibre perimeter ratio of the normal and the hypertrophied plantaris muscle. These results indicated that chronic overload-induced neocapillarization, but not enlargement of capillary luminal circumference, contributed to the prevention of decreases in the capillary-to-fibre perimeter ratio in the plantaris muscle in the hypertrophied process.

Adaptation, Physiological↗