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K Ohta

Publications and source records attributed to K Ohta.

At least 361 records · Page 20Linked to original sources
PubMed1996

Distribution of and age-related changes in ciliary neurotrophic factor protein in rat tissues.

We developed a sensitive enzyme-linked immunosolvent assay for measuring ciliary neurotrophic factor (CNTF) and examined age-related changes in the CNTF contents of a variety of rat tissues during postnatal development. CNTF contents were substantially higher in the sciatic nerve and spinal cord than in the other tissues tested, the kidney coming third. In all the tissues except the sciatic nerve (90 ng/g), the CNTF content was less than 1 ng/g at 1 week of age, then gradually increased. It was highest at 5 weeks of age in the sciatic nerve (3171 ng/g), spinal cord (118 ng/g), and kidney (36.8 ng/g), after which it slowly decreased. In contrast, the maximum in the brain stem (9 ng/g) and cerebellum (3.6 ng/g) was at 8 weeks of age, whereas in skeletal muscle it was at 2 weeks of age (14.6 ng/g). These findings indicate that CNTF functions in the postnatal development of the rat.

Aging↗
PubMed1996

Evaluation of sialyl Lewisx antigen in the skin and the sera of patients with psoriasis vulgaris.

The roles of sialyl-Lewisx antigen were evaluated in the pathogenesis of psoriasis. Sialyl-Lewisx expression was investigated immunohistochemically in the epidermis of normal human skin and erythematous lesional skin of psoriasis vulgaris by avidin-biotin-peroxidase complex procedures. A few sialyl-Lewisx positive dendritic cells were detected in the epidermis of normal human skin. In 7 out of 9 cases of psoriasis vulgaris, the number of sialyl-Lewisx-positive epidermal dendritic cells increased in the erythematous lesion over the adjacent normal skin; there were no marked changes in the numbers of CD1a-positive cells in the epidermis between the two skin types. In the double immunofluorescence studies, more than half of the sialyl-Lewisx-positive epidermal cells in psoriatic erythema were stained with a monoclonal Lag antibody that specifically reacts with Birbeck granules and related structures of human Langerhans cells. Furthermore, we determined the changes in serum levels of sialyl-Lewisx antigens in patients with psoriasis. Although levels in the sera were not significantly elevated over those of controls, the increases correlated with the degree of disease activity. These findings suggest that sialyl-Lewisx antigen is possibly involved in the development of psoriasis.

Biopsy, Needle↗
PubMed1996

Effects of an AT1 receptor antagonist, an ACE inhibitor and a calcium channel antagonist on cardiac gene expressions in hypertensive rats.

1. This study was undertaken to determine whether the AT1 receptor directly contributes to hypertension-induced cardiac hypertrophy and gene expressions. 2. Stroke-prone spontaneously hypertensive rats (SHRSP) were given orally an AT1, receptor antagonist (losartan, 30 mg kg-1 day-1), an angiotensin converting enzyme inhibitor (enalapril 10 mg kg-1 day-1), a dihydropyridine calcium channel antagonist (amlodipine, 5 mg kg-1 day-1), or vehicle (control), for 8 weeks (from 16 to 24 weeks of age). The effects of each drug were compared on ventricular weight and mRNA levels for myocardial phenotype- and fibrosis-related genes. 3. Left ventricular hypertrophy of SHRSP was accompanied by the increase in mRNA levels for two foetal phenotypes of contractile proteins (skeletal alpha-actin and beta-myosin heavy chain (beta-MHC)), atrial natriuretic polypeptide (ANP), transforming growth factor-beta-1 (TGF-beta 1) and collagen, and a decrease in mRNA levels for an adult phenotype of contractile protein (alpha-MHC). Thus, the left ventricle of SHRSP was characterized by myocardial transition from an adult to a foetal phenotype and interstitial fibrosis at the molecular level. 4. Although losartan, enalapril and amlodipine lowered blood pressure of SHRSP to a comparable degree throughout the treatment, losartan caused regression of left ventricular hypertrophy of SHRSP to a greater extent than amlodipine (P < 0.01). 5. Losartan significantly decreased mRNA levels for skeletal alpha-actin, ANP, TGF-beta 1 and collagen types I, III and IV and increased alpha-MHC mRNA in the left ventricle of SHRSP. Amlodipine did not alter left ventricular ANP, alpha-MHC and collagen types I and IV mRNA levels of SHRSP. 6. The effects of enalapril on left ventricular hypertrophy and gene expressions of SHRSP were similar to those of losartan, except for the lack of inhibition of collagen type I expression by enalapril. 7. Unlike the hypertrophied left ventricle, there was no significant difference between losartan and amlodipine in the effects on non-hypertrophied right ventricular gene expressions of SHRSP. 8. Our results show that hypertension causes not only left ventricular hypertrophy but also molecular transition of myocardium to a foetal phenotype and interstitial fibrosis-related molecular changes. These hypertension-induced left ventricular molecular changes may be at least in part mediated by the direct action of local angiotensin II via the AT1, receptor.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

[Characteristics of Salmonella strains isolated from sporadic diarrheal cases during 1992-1994 in the Philippines].

A total of 263 Salmonella strains isolated in Metro Manila, the Philippines from 1992 to 1994, were examined for their serovar-distribution and drug-resistance. Salmonella serovar Typhi (S. Typhi) and S. Enteritidis phage type was also tested. The serological typing results showed that the strains were classified into 10 O-groups and 32 serovars. S. Weltevreden, S. Enteritidis, S. Typhi, S. Typhimurium, and S. Derby were predominant in the serovars identified. The drug-resistance test using nine drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 95 strains (36.1%) were resistant to any of the seven drugs except FOM and NFLX. The serovars of a high resistant rate were S. Ruiru (100%), S. Typhimurium (87.0%), S. Senftenberg (80.0%), S. Derby (66.7%), and S. Agona (50.0%). Drug-resistance patterns of the resistant strains varied to 21 types, and 80 of them were multidrug-resistant. Phage types of 37 S. Typhi strains were B1 (27 strains), E2 (6 strains), and others (4 strains). Phage types of 38 S. Enteritidis strains were 4 (32 strains), 7 (3 strains), and others (3 strains).

Ampicillin Resistance↗
PubMed1996

[Evolution of susceptibilities of Campylobacter jejuni isolated from diarrhoeal cases to fluoroquinolones in Tokyo].

Recently, the increase in the number of resistant strains of Campylobacter jejuni to fluoroquinolone has been reported in European countries. We also studied antimicrobial susceptibilities of 600 clinical isolates of Campylobacter jejuni isolated during a 6 year period from 1989 through 1994 in four Tokyo Metropolitan Hospitals. The susceptibility to 6 antimicrobial agents, norfloxacin (NFLX), ofloxacin (OFLX), ciprofloxacin (CPFX), nalidixic acid (NA), erythromycin (EM) and tetracycline (TC) were examined. The overall resistant rates were as follows: NFLX, 45 strains (7.5%); OFLX, 45 strains (7.5%); CPFX, 44 strains (7.3%); NA, 62 strains (10.3%); EM, 4 strains (0.6%) and TC, 259 strains (43.2%). The number of resistant strains to fluoroquinolones and NA has increased significantly since 1993 in Japan, but the susceptibility to erythromycin has still remained the same level during the past 6 years. The susceptibility to TC was variable, and MICs gave a bimobal distribution, as pointed out previously. The resistance pattern of NFLX, OFLX, CPFX and NA were observed most frequently in those isolates.

Anti-Infective Agents↗
PubMed1996

[Serovar-distribution and drug-resistance of Salmonella strains isolated from domestic and imported cases in 1990-1994 in Tokyo].

A total of 3,647 non-typhoidal Salmonella strains consisting of 2,655 domestic strains and 992 imported strains isolated in Tokyo from 1990 to 1994, were examined for their serovar-distribution and their drug-resistance. The serological typing results showed that the domestic strains were classified into 15 O-groups and 96 serovars, and the imported strains were classified into 13 O-groups and 73 serovars. Among the serovars identified, Salmonella serovar Enteritidis (S. Enteritidis), S. Thompson, S. Hadar, S. Litchfield, and S. Tennessee were predominant in the domestic strains, whereas S. Hadar, S. Enteritidis, S. Anatum, S. Derby, and S. Blockley were predominant in the imported strains. The drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 30.5% of the domestic strains and 40.5% of the imported strains were resistant to any of the drugs examined. The serovars of a high resistant rate during this period were S. Hadar (96.2%), S. Blockley (88.7%), S. Enteritidis (63.4%), S. Virchow (54.3%), and S. Typhimurium (51.3%) in the domestic strains and S. Krefeld (100%), S. Hadar (98.9%), S. Blockley (98.2%), S. Emek (83.3%), S. Kentucky (76.5%), S. Panama (69.2%), S. Derby (63.8%), S. Typhimurium (57.1%), S. Rissen (55.6%), and S. Agona (53.7%) in the imported strains. Drug-resistance patterns of the resistant isolates varied to 62 types. Prevalent patterns recognized were SM, TC.SM, TC.SM.KM, TC, TC.SM.KM.ABPC and CP.TC.SM.KM in the domestic strains and TC.SM, TC, CP.TC.SM.ST, TC.SM.KM, and CP.TC.SM.KM in the imported strains.

Diarrhea↗
PubMed1996

[Detection of the trh gene in Vibrio parahaemolyticus isolated from overseas travellers' diarrhea and their biochemical characteristics].

A total of 478 Vibrio parahaemolyticus strains isolated from overseas travellers' diarrhea during the last 7 years of 1989 to 1995 were examined for the production of Kanagawa hemolysin by reversed passive latex agglutination (RPLA) test. Three hundred-seventy (77.4%) out of 478 strains were positive for Kanagawa hemolysin, whereas 108 strains were weakly positive or negative. For those Kanagawa hemolysin-weakly positive or negative strains, the tdh and trh genes associated with the production of TDH (thermostable direct hemolysin) and TRH (TDH-related hemolysin), respectively, were studied by the polymerase chain reaction method. The trh gene was detected in 98 (90.7%) out of 108 strains. In 35 strains belonging to 13 serotypes such as O3: K6, O1:K33, O3:K59, the trh gene alone was detected. On the other hand, both trh and tdh genes were detected in 63 strains of 17 serotypes including O1:K69, O3:K72, O6:K46. Among the strains of 4 serotypes including O1:K56, O1:KUT, O3:KUT and O5:KUT, two types of the trh positive alone and the trh and tdh positive were observed. Of interest, all of the 98 trh-positive strains were positive for the urease hydrolysis, whereas all Kanagawa hemolysin-positive strains were not. Furthermore, the strains of serotype O6:K18 (4 strains) were positive for the fermentation of dulcitol, and the strains of serotype O1:K1 (5 strains) were indole negative. These characteristics of the strains were completely different from those of typical V. parahaemolyticus strains.

Diarrhea↗
PubMed1996

T lymphocytes and silica-induced pulmonary inflammation and fibrosis in mice.

BACKGROUND: Silica-induced pulmonary inflammation and fibrosis in animals provides a good model for chronic pulmonary inflammation and fibrosis. Although lymphocytes are implicated in the pathogenesis of pulmonary fibrosis, experimental models using silica-treated athymic nude mice have not been successful in showing the fibrogenic mechanism regulated by T cells. The aim of this study was to re-evaluate the role of T lymphocytes in the development of silicosis by comparing the response to silica administration of nude athymic mutants with that of euthymic animals. METHODS: Suspensions of silica particles were transnasally administered to nude athymic mice (Balb/c nu/nu) as well as to their euthymic littermates (Balb/c nu/+). The degree of pulmonary inflammation and fibrosis was assessed on days 14, 28, and 56 based upon histological observation, analysis of collagen deposition in the lungs, and analysis of the cellular constituent, protein, and phospholipid content in the bronchoalveolar lavage fluid. RESULTS: Histologically, athymic mice developed less severe interstitial pneumonitis than euthymic mice. In euthymic mice the lung hydroxyproline content increased with time after silica administration from 6.48 (0.38) micrograms hydroxyproline/mg dry lung weight on day 0 to 8.87 (0.41) micrograms/mg on day 56. A gradual increase in lung hydroxyproline content was also observed in athymic mice but the increase was significantly smaller than in euthymic mice (6.63 (0.43) micrograms/mg on day 0, 7.90 (0.19) micrograms/mg on day 56). Administration of silica resulted in an increase in the number of macrophages and neutrophils and in the total protein and phospholipid content of the bronchoalveolar lavage (BAL) fluid in both mouse strains. No significant difference was detected between athymic and euthymic mice in the numbers of macrophages, but the increase in neutrophils in the BAL fluid of athymic mice was significantly smaller than in euthymic mice on days 14 and 56. The total protein and phospholipid content of the BAL fluid from athymic mice was lower than that from euthymic mice. CONCLUSIONS: T lymphocytes appear to be involved in the pathogenesis of silica-induced pneumonitis. Since pulmonary fibrosis develops even in nude athymic mice, T cells do not seem to play a primary part in fibrogenic response but they regulate, at least to some extent, the response of inflammatory cells and fibrogenesis of the lung.

Animals↗
PubMed1996

Role of angiotensin-converting enzyme, adrenergic receptors, and blood pressure in cardiac gene expression of spontaneously hypertensive rats during development.

We undertook this study to investigate the regulatory mechanism of cardiac gene expression in spontaneously hypertensive rats (SHR) during development. We measured cardiac mRNAs by Northern blot analysis. In 9-week-old SHR at the very early stage of cardiac hypertrophy, the expression of various cardiac genes related to the regulation of cardiac contraction and relaxation was already significantly changed compared with control Wistar-Kyoto rats, indicating that cardiac molecular changes are responsible for cardiac remodeling or the modulation of cardiac performance in SHR. We gave various types of antihypertensive drugs, at oral doses causing a mild and comparable hypotensive effect, to 27-week-old SHR to examine the effects on the altered cardiac gene expression. Imidapril, an angiotensin-converting enzyme inhibitor, normalized the increased gene expression of atrial natriuretic polypeptide and collagen types I and III and the decreased expression of alpha-myosin heavy chain in SHR heart. Atenolol (a beta 1-blocker) combined with doxazosin did not affect cardiac ANP and alpha-myosin heavy chain expression of SHR but normalized the increased collagen expression. In contrast, despite a hypotensive effect comparable to these two drug treatments, doxazosin (an alpha 1-blocker) alone or manidipine (a calcium antagonist) did not normalize these altered gene expressions of SHR. These results show that the cardiac renin-angiotensin system is involved in the altered cardiac gene expression in SHR. The beta 1- but not alpha 1-adrenergic receptor is also responsible for the increased cardiac collagen expression in SHR.

Actins↗
PubMed1996

Antitumor actions of cytokines on new human papillary thyroid carcinoma cell lines.

To investigate the in vitro effects of cytokines on the growth of human papillary thyroid carcinoma (PTC) cells, we established six new PTC cell lines, designated BHP 5, 14, 15, 17, 18, and 19, from different patients. We studied the antiproliferative actions of cytokines by using BHP cells, NP cells (PTC cell line), and ARO cells (anaplastic thyroid carcinoma cell line). These cells were treated with various concentrations of tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN gamma), interleukin-1 beta (IL-1 beta), and transforming growth factor-beta 1 (TGF beta 1), alone and in combination. Cell proliferation was assessed by [3H]thymidine incorporation and cell number measurement. In BHP cell lines, IFN gamma, IL-1 beta, and TGF beta 1 inhibited [3H]thymidine incorporation and decreased cell number, but TNF alpha stimulated [3H]thymidine incorporation. In NP cells, treatment with each cytokine decreased [3H]thymidine incorporation and cell number. In contrast, the proliferation of ARO cells was either stimulated by or resistant to TNF alpha, IL-1 beta, and TGF beta 1. The effects of these cytokines on [3H]thymidine incorporation were additive in these cell lines. The results suggest that IL-1 beta and TGF beta 1 play a pivotal role in growth inhibition of PTC cells, and the escape from negative control of IL-1 beta and TGF beta 1 may be a step toward anaplastic changes. The additive effects of these cytokines suggest that they act through different pathways.

Animals↗
PubMed1996

Regional specification of motoneurons along the anterior-posterior axis is independent of the notochord.

Cek8 and low affinity NGF receptor (LNGFR) are expressed at high levels on the chick spinal motoneurons of the brachial and lumbar segments from embryonic day (E) 5 to E7, but weakly on the motoneurons of the non-limb-innervating segments. We determined by means of heterotopic neural tube transplantation, that the expression of these molecules was already intrinsically determined at E2. We used these spatiotemporal specific molecules as markers of motoneuron subpopulations. To analyze how motoneurons acquire regional specification along the anterior-posterior (A-P) axis and in the transverse plane, we observed the expression of these molecules on ectopic motoneurons induced by implanting a supernumerary notochord or floor plate at E2. The ectopic motoneurons induced by the graft obtained from either the thoracic or lumbar segments had the same expression profile as the normal motoneurons at each A-P level. These findings suggest that regional specification of motoneurons, at least of Cek8 and LNGFR expression, is independent of the notochord and the floor plate and that the whole neural tube appears to be committed to differentiate into the motoneuron subtypes along the A-P axis at the operative stages.

Animals↗
PubMed1996

Nucleotide sequence of a cDNA coding for cyclophilin of the sea urchin Hemicentrotus pulcherrimus.

We present the nucleotide sequence of a cDNA coding for cyclophilin homologue of the sea urchin Hemicentrotus pulcherrimus. The 1,755-nucleotide sequence contains a 492-bp open reading frame corresponding to a translation product of 164 amino acids. Comparison of the deduced amino acid sequence with the previous data shows a high degree of conservation (approximately 80% homology). Southern blot analysis of genomic DNA suggests the presence of a multigene for sea urchin cyclophilin. Northern blot analysis indicates a mRNA size of approximately 3 kb and that message is accumulated at blastula stage.

Amino Acid Isomerases↗
PubMed1996

Apoptosis-related fas antigen on memory T cells in aqueous humor of uveitis patients.

To investigate the role of lymphocytes in the pathogenesis of uveitis, we analyzed the expression of memory markers, CD29 and CD45RO antigens, and apoptosis-related Fas antigen on T lymphocytes in the aqueous humor (AH) and peripheral blood (PB) from patients with uveitis. Using three-color flow cytometry, we assessed the number of T lymphocyte subsets that stained with fluorescence-conjugated anti-CD3, CD4, CD8, CD29, CD45RA, CD45RO, HLA-DR, and Fas monoclonal antibodies in the AH and PB from 19 patients with active uveitis who were diagnosed as having sarcoidosis, Vogt-Koyanagi-Harada disease, HLA-B27+ uveitis, or idiopathic uveitis. Cells from AH and PB were evaluated by light and electron microscopy before and after 6 h of incubation. The majority of lymphocytes in AH but not in PB, were CD3+HLA-DR+ (activated) T cells. The percentage of CD4+ lymphocytes was significantly higher in uveitic AH than in PBL (P < 0.01). While the percentage of CD4+ CD45RA+ (naive) cells within T cells was much lower in uveitic AH than in PB, the percentage of CD4+CD29+ or CD4+CD45RO+ (memory) cells was significantly higher in uveitic AH than in PBL (P < 0.01). Fas antigen was expressed preferentially on memory cells in uveitic AH. Apoptosis of cells in the AH was observed by microscopically following after incubation with no stimulation. Lymphocytes from the AH of patients with uveitis were more activated than those from PB. The majority of T lymphocytes from uveitic AH expressed memory markers and Fas antigen. Results suggest that an increase in the number of Fas+ memory T lymphocytes in AH is involved in the pathogenesis of uveitis.

Adolescent↗
PubMed1996

[Quality control of surgery in multicenter study--interinstitutional and individual differences].

UNLABELLED: In a prospective randomized controlled trial (PRCT) of adjuvant chemotherapy for gastric cancer patients participated by 6 cancer center hospitals, inter-institutional and inter-individual differences about several factors related to the surgery and remote survivals were analyzed. From 1988 to 1992, 1,049 evaluable patients were enrolled and stratified to 6 groups according to the grade of the serosal invasion and curability, and analyzed statistically. RESULTS: 1) There were no inter-institutional differences about postoperative survival rate, but there were slight differences about patient's background factors and entry policy of each institution. 2) There were no inter-institutional differences about several factors related to the surgery such as operative time, bleeding volume during operation, and the length of the administration periods. 3) There were no inter-individual differences about the length of the administration periods, but there were a little differences about operative time and the volume of hemorrhage. When the PRCT of adjuvant chemotherapy of which the end point is survival would be designed, no inter-institutional differences about remote survival and surgical operation in each institution should be confirmed before starting the trial.

Chemotherapy, Adjuvant↗
PubMed1996

[LY188011 phase I study. Research Group of Gemcitabine (LY188011)].

LY188011 (Gemcitabine hydrochloride) is a new derivative of deoxycytidine. Phase I study was carried out by a cooperative study group. LY188011 was administered weekly for 3 consecutive weeks starting with an initial dose of 60 mg/m2 (1n) and then increasing the dosage to 1,000 mg/m2 (16.7n). Dose limiting factor was found to be myelosuppression (decreases of WBC, neutrophils and platelet), and MTD was considered to be 1,000 mg/m2. The nadir of WBC and platelet were observed after about 1-3 weeks. It took 1-2 weeks for their recovery. Other adverse reactions included fever, fatigue, anorexia, nausea/vomiting, anemia and transient elevations of GOT and GPT. However, those adverse reactions were mild. T1/2 rho of plasma concentration was about 19 min and the C5min was dependent on the dose. Anti-cancer effects were observed in one gastric cancer and two colon cancer patients. It is recommended that the dosing schedule for an early phase II study is 800 mg/m2 weekly for 3 weeks with 1 week of rest as one cycle, in multiple cycles.

Adult↗