Biomedical subjects

S Kotake

Publications and source records attributed to S Kotake.

At least 55 records · Page 3Linked to original sources

PubMed1998

Identification of a peptide inducing experimental autoimmune uveoretinitis (EAU) in H-2Ak-carrying mice.

When certain strains of mice bearing H-2Ak are immunized with the interphotoreceptor retinoid-binding protein (IRBP), EAU is induced. Thus far uveitogenic determinant(s) has not been determined in the H-2Ak mouse system. In addition it is hard to prepare purified IRBP. In the present study, to circumvent these problems we attempted to identify uveitogenic peptides derived from bovine IRBP in H-2Ak haplotype mice. Six peptides which had been selected according to the H-2Ak binding motif (Dxxxxxxxx[A, R, T]) were synthesized. We report here that all the peptides are immunogenic but only one peptide, K2, which consisted of IRBP201-216 residues, induces EAU in various mice carrying H-2Ak. Amino acid substitution of K2 revealed that the core region interacted with both H-2Ak and T cell antigen receptor (TCR). The amino acid sequence of the core region derived from bovine IRBP was identical to the corresponding region of mouse IRBP. In addition, K2 appeared to be a natural peptide antigen processed from bovine IRBP. Altogether, we concluded that K2 is one of the natural autoantigens involved in induction of EAU in H-2Ak mice.

Amino Acid Sequence↗

PubMed1998

MICA gene polymorphisms and HLA-B27 subtypes in Japanese patients with HLA-B27-associated acute anterior uveitis.

PURPOSE: HLA-B27-associated acute anterior uveitis (HLA-B27 AAU) seems to be triggered by external factors in persons with a particular genetic background. It is still uncertain whether HLA-B27 or other gene(s) near the HLA-B region predisposes to uveitis in a linkage disequilibrium with B27. The authors investigated microsatellite polymorphism within the transmembrane region of the MICA gene, located 47 kb centromeric of the HLA-B gene, and HLA-B27 subtypes. METHODS: Seventeen HLA-B27-positive Japanese patients with HLA-B27 AAU, 51 Japanese controls, and 20 B27-positive Japanese controls were examined for MICA gene polymorphism within the transmembrane region using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology. Furthermore, B27-positive patients with HLA-B27 AAU and B27-positive controls were examined for HLA-B27 subtypes by the PCR-sequence-specific primer method. RESULTS: The microsatellite allele in the MICA gene, consisting of four repetitions of GCT/AGC (designated A4 allele), was present at a significantly higher phenotype frequency in the patient group (64.7%) than in the control group (25.5%) (chi 2 = 6.95, Pc = 0.042). Furthermore, the frequency of the A4 allele was significantly higher, even when compared with 20% in the B27-positive control group (chi 2 = 5.88, Pc = 0.042). The frequency of HLA-B27 subtypes was not significantly different between B27-positive patients with HLA-B27 AAU and B27-positive controls. CONCLUSIONS: These results suggest that the MICA gene itself, or other nearby gene(s), linked to the MICA A4 allele may be involved in the development of HLA-B27 AAU and that HLA-B27 subtypes are not important in the development of HLA-B27 AAU in a Japanese population.

Acute Disease↗

PubMed1998

[Clinical manifestations and diagnosis of patients with sarcoidosis].

We reviewed the records of new patients with uveitis who visited the Hokkaido University Hospital between 1991 and 1994. For the diagnosis of sarcoidosis, we used the criteria revised by the Diffuse Pulmonary Disease Research Committee of Japan in 1989. The total number of patients was 374, and 61 cases were diagnosed as sarcoidosis. Of 61 patients with sarcoidosis, 58 cases were diagnosed histologically. Transbronchial lung biopsy was the basis for 70% of the histological diagnosis. After the revision of the criteria of sarcoidosis, the percentage of histological diagnosis increased. The Diffuse Pulmonary Disease Research Committee of Japan also proposed guidelines for the diagnosis of ocular sarcoidosis in 1990. We applied these guidelines to our uveitis patients. Most of the patients (77.1%) with sarcoidosis were included in the group of probable sarcoidosis, but 20% of patients with uveitis who were not diagnosed as having sarcoidosis were also included in this group. These guidelines are not yet adequate.

Adult↗

PubMed1997

Effects of recombinant human bone morphogenetic protein-2 on human bone marrow cells cultured with various biomaterials.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is known to induce orthotopic and ectopic bone formation in vivo. Several in vitro studies using rat or mouse clonal cell lines have shown that rhBMP-2 may be involved in the differentiation of osteoblasts from osteoblast precursor cells or stromal cells in the bone marrow. However, there is little information available about the effects of rhBMP-2 on cultured human bone marrow cells. We investigated the effects of rhBMP-2 cultured on human bone marrow cells and osteoblastic cells on various biomaterials. Human bone cells were divided into fresh bone marrow cells, fibroblast colony-forming units (cfu-F, stromal precursors), and osteoblastic cells. The cells were cultured with or without rhBMP-2 on various biomaterials, including titanium alloy, pure titanium, cobalt alloy, and hydroxyapatite. It was found that rhBMP-2 (500 ng/mL) significantly stimulated alkaline phosphatase production by fresh bone marrow cells and cfu-F. However, when cultured on titanium alloy or pure titanium, only fresh bone marrow cells showed an increase of alkaline phosphatase production after rhBMP-2 stimulation. Production of osteocalcin, a marker of mature osteoblasts, was not stimulated by rhBMP-2 in any combinations tested. These findings suggest that rhBMP-2 may be involved in inducing the differentiation of osteoblast precursor cells into osteoblastic cells rather than stimulating further differentiation of osteoblastic cells into mature osteoblasts. In addition, grafts of fresh human bone marrow cells of cfu-F stimulated by rhBMP-2 may have the potential to promote bone formation at sites of nonunion as well as around titanium joint prostheses.

Adult↗

PubMed1997

Characteristics of endogenous uveitis in Hokkaido, Japan.

BACKGROUND: Etiological characteristics of endogenous uveitis vary among areas and races around the world. There are few epidemiological reports on the etiology of uveitis from areas within Asia. We report statistical data on uveitis in Japan. METHODS: We reviewed all of the records of patients with endogenous uveitis who visited the Uveitis Survey Clinic of Hokkaido University Hospital in 1981 and 1994 and extended the survey to include new patients with uveitis seen over the 3-year period from 1992 to 1994. RESULTS: Bechcet's disease, sarcoidosis and Vogt-Koy-anagi-Harada disease were the three most frequently diagnosed diseases in both 1981 and 1994. The proportion of patients with unclassified uveitis decreased from 38% to 30% during the 13-year period from 1981 to 1994 as a result of the establishment of new disease categories during this time. Notable additions included human T-lymphotropic virus type 1-associated uveitis and tubuloinerstitial nephritis and uveitis syndrome. Sarcoidosis is now the most frequent endogenous uveitis in our clinic. CONCLUSION: Not only does the etiological basis of uveitis vary among ethnic groups but advances in clinical and basic research have changed the diagnostic approach to uveitis, altering the etiological profile over time.

Adolescent↗

PubMed1997

Levels of endogenous interleukin-1, interleukin-6, and tumor necrosis factor in congenic mice infected with Borrelia garinii.

This study describes the levels of interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) in the sera and parenchymal organs of various congenic mouse strains infected with Borrelia garinii. A significant elevation of inflammatory cytokine levels was found in the organs of C3H/HeN (H-2k) and B10.BR (H-2k) mice but not in those of BALB/c mice (H-2d). Focally produced cytokines can contribute to antimicrobial defense against these organisms. High levels of IL-1 alpha were observed in the sera of C3H/HeN, B10.BR and B10 (H-2b) mice infected with B. garinii and they were associated with the presence of spirochetes in the skin. Thus, susceptible mice demonstrated a stronger cytokine response than resistant mice. This study presents in vivo evidence that B. garinii infection affects the immunopathogenesis of Lyme disease.

Animals↗

PubMed1997

In vivo gene expression of type 1 and type 2 cytokines in synovial tissues from patients in early stages of rheumatoid, reactive, and undifferentiated arthritis.

It has been reported that the mRNA of the type 1 cytokine, interferon-gamma (IFN-gamma)--but not the type 2 cytokine interleukin-4 (IL-4)--is detected in synovial tissues of rheumatoid arthritis (RA) patients, whereas both IFN-gamma and IL-4 mRNA are detected in reactive arthritis (ReA). To evaluate such data more extensively, we obtained 208 synovial specimens in a prospective study of 52 early synovitis patients (13 RA, 11 ReA, 28 undifferentiated oligoarthropathy) and analyzed type 1 and type 2 cytokine mRNA expression in specimens containing sufficient mRNA. Using a nested reverse transcriptase polymerase chain reaction technique, we measured the relative mRNA levels of 10 cytokines and CD3 delta chain. We detected IL-10, IL-15, and CD3 delta chain mRNA in all RA and ReA patients and frequently detected tumor necrosis factor-alpha, IL-1 beta, and IFN-gamma mRNA. IL-6 and IL-12 p40 mRNA were detected in approximately one-half of the patients. We also detected greater amounts of IL-2 and IFN-gamma mRNA in ReA than were detected in RA. However, we rarely detected IL-4 or IL-13 mRNA. Similar cytokine profiles were observed in undifferentiated oligoarthropathy. The amounts of cytokine mRNAs, except for IL-10, in specimens from the patients taking prednisone or second-line antirheumatic drugs tended to be less than in specimens from the patients taking neither prednisone nor second-line antirheumatic drugs. These results suggest that cytokine mRNA profiles in patients with RA, ReA, and undifferentiated arthritis in their early stages are skewed toward proinflammatory macrophage-derived and type 1 cytokines. IL-10--not IL-4 or IL-13--mRNA appears to be the major antiinflammatory cytokine mRNA. Drug therapy is associated with depressed proinflammatory and type 1 cytokine mRNA production. The differences in the expression of IL-2 and IFN-gamma mRNA between RA and ReA may reflect unique etiological or host factors associated with the early stages of these diseases.

Adult↗

PubMed1996

A simple nested RT-PCR method for quantitation of the relative amounts of multiple cytokine mRNAs in small tissue samples.

It is difficult to quantitate cytokine mRNA profiles in small human tissue specimens obtained by a needle biopsy, even using standard RT-PCR methods, because the amount of mRNA in the specimens is very small. To address this problem, we developed highly sensitive, quantitative, nested RT-PCR techniques to evaluate the expression of multiple cytokine mRNAs in synovial specimens obtained by needle biopsy. To reduce effects of variation of initial RNA concentrations, cDNA from each target RNA sample was normalized, using a simplified competitive PCR method, to the levels of beta-actin cDNA. The first and the second (nested) PCR were performed in the same tube to prevent contamination. The number of PCR-product bands, evident on polyacrylamide gel electrophoresis, was used to quantitate the relative amounts of target cDNA. Using our methods, it was possible to evaluate, in a single synovial tissue specimen obtained by needle biopsy, the relative amounts of mRNAs for 10 cytokines (TNF-alpha, IL-1 beta, IL-2, IL-4, IL-6, IL-10, IL-12 p40, IL-13, IL-15, IFN-gamma) and CD3 delta chain. Our methods are particularly valuable if there are multiple target mRNAs, numerous samples, or if the amounts of mRNAs are limited. The methods are applicable to a wide variety of tissues and target mRNAs.

Arthritis, Rheumatoid↗

PubMed1996

Genetic maps of polymorphic DNA loci on rat chromosome 1.

Genetic linkage maps of loci defined by polymorphic DNA markers on rat chromosome 1 were constructed by genotyping F2 progeny of F344/N x LEW/N, BN/SsN x LEW/N, and DA/Bkl x F344/Hsd inbred rat strains. In total, 43 markers were mapped, of which 3 were restriction fragment length polymorphisms and the others were simple sequence length polymorphisms. Nineteen of these markers were associated with genes. Six markers for five genes, gamma-aminobutyric acid receptor beta3 (Gabrb3), syntaxin 2 (Stx2), adrenergic receptor beta1 (Adrb1), carcinoembryonic antigen gene family member 1 (Cgm1), and lipogenic protein S14 (Lpgp), and 20 anonymous loci were not previously reported. Thirteen gene loci (Myl2, Aldoa, Tnt, Igf2, Prkcg, Cgm4, Calm3, Cgm3, Psbp1, Sa, Hbb, Ins1, and Tcp1) were previously mapped. Comparative mapping analysis indicated that a large portion of rat chromosome 1 is homologous to mouse chromosome 7, although the homologs of two rat genes are located on mouse chromosomes 17 and 19. Homologs of the rat chromosome 1 genes that we mapped are located on human chromosomes 6, 10, 11, 12, 15, 16, and 19.

Animals↗

PubMed1996

Linkage maps of rat chromosomes 15, 16, 17, 19, and X.

Linkage maps of rat chromosomes 15, 16, 17, 19, and X were constructed by multipoint genetic linkage analysis of 22 polymorphic markers in 40 F2 progeny of Fischer (F344/N) and Lewis (LEW/N) inbred rat strains. These markers are associated with eight genes (angiotensin receptor A, M3 muscarinic acetylcholine receptor, heme oxygenase, endothelin receptor A, haptoglobin, tyrosine aminotransferase, phosphoribosylpyrophosphate synthetase subunit II, and 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase) and 14 anonymous loci. Linkage analysis placed the markers into five linkage groups covering 11.7,7.9,11.6,42.5, and 5.1cM. These linkage groups were assigned to rat chromosomes 15, 16, 17, 19, and X, respectively, either by mouse x rat somatic cell hybrid analysis or based on previously identified locations of severalloci. In polymorphism analysis, these markers exhibited two to nine different alleles in 16 inbred rat strains.

Alleles↗

PubMed1996

Interleukin-6 and soluble interleukin-6 receptors in the synovial fluids from rheumatoid arthritis patients are responsible for osteoclast-like cell formation.

Chronic immune responses and inflammatory reactions in rheumatoid arthritis (RA) often cause severe destruction of cartilage and bone, but its mechanism is still a matter of controversy. We reported that interleukin-6 (IL-6) alone does not induce osteoclast formation, but soluble interleukin-6 receptors (sIL-6R) triggered the formation in the presence of IL-6 in cocultures of murine osteoblastic cells and bone marrow cells. In this study, we examined the involvement of sIL-6R and IL-6 in joint destruction in patients with RA. Although the frequency of patients having osteoclast-like multinucleated cells in synovium derived from the knee joint was not significantly different between RA (65%) and osteoarthritis (OA) patients (43%), the number of osteoclast-like cells found in the synovium was greater in the former than in the latter. Multinucleated cells obtained from RA synovium expressed the osteoclast-specific phenotype such as tartrate-resistant acid phosphatase, carbonic anhydrase II, vacuolar proton-ATPase and vitronectin receptors at similar levels to those from a human giant cell tumor of bone. The concentration of both IL-6 and sIL-6R was significantly higher in the synovial fluids from patients with RA than with OA. The concentration of IL-6 and sIL-6R correlated well with the roentgenologic grades of joint destruction. Dose-response curves for human IL-6 and human sIL-6R in inducing osteoclast-like cell formation in cocultures indicated that the RA synovial fluids contained sufficient IL-6 and sIL-6R to induce osteoclastogenesis. When synovial fluids from RA and OA patients were added to the cocultures, some of the RA synovial fluids containing high levels of IL-6 and sIL-6R stimulated osteoclast-like cell formation, which was strikingly inhibited by adding anti-IL-6R antibody simultaneously. These results suggest that IL-6 in the RA synovial fluids is at least in part responsible for joint destruction in the presence of sIL-6R through osteoclastogenesis.

Acid Phosphatase↗

PubMed1996

Localization of the gene responsible for the op (osteopetrotic) defect in rats on chromosome 10.

Osteopetrosis, a skeletal disorder of inadequate bone resorption with an abnormal increase in skeletal mass, results from a variety of independent single gene mutations that affect osteoclast differentiation and/or function. The osteopetrotic defect, op, is one of four spontaneous, nonallelic mutations in rats that result in osteopetrosis. In intercross progeny of (BN/SsN x LEW/SsN. +/op) F1 carriers, we mapped this locus by linkage analysis with microsatellite markers to rat chromosome 10. The linkage group contained, as well as op, 15 anonymous DNA loci and 9 DNA loci associated with genes (interleukin-3, myosin heavy chain [skeletal, embryonic], asialoglycoprotein receptor [hepatic lectin]-1, vesicle-associated membrane protein [synaptobrevin-2], sex hormone binding globulin, aldolase C, nitric oxide synthase [inducible], erythroblastic leukemia avian viral oncogene homolog-2, and proline-rich protein). The markers for these loci include nine not previously reported. The op locus mapped to the end of the chromosome 10 linkage group, within 1 cM of the anonymous DNA locus, D10Mit6. Based on its location, the op gene is likely to be distinct from seven described mutations in mice as well as three other mutations in rats. These results may permit a positional cloning strategy to be undertaken to identify the gene and mutation underlying the op defect.

Animals↗

PubMed1996

Characteristics of endogenous uveitis in Hokkaido, Japan.

BACKGROUND: Etiological characteristics of endogenous uveitis vary around the world. There are few epidemiological reports on the etiology of uveitis from areas within Asia. We set out to examine the statistical data on uveitis in Japan. METHODS: We reviewed all the records of patients with endogenous uveitis who visited the Uveitis Survey Clinic of Hokkaido University Hospital in 1981 and 1994 and extended the survey to include new patients with uveitis seen over the past 3 years. RESULTS: Behçet's disease, sarcoidosis and Vogt-Koyanagi-Harada disease were the three most frequently diagnosed diseases in patients with endogenous uveitis in both 1981 and and 1994. The proportion of patients with unclassified disease entities decreased (from 38% to 30%) during the 13-year period from 1981 to 1994 as a result of the new disease categories established during this interval. Notable additions included human T-lymphotropic virus type 1-associated uveitis and tubulointerstitial nephritis and uveitis syndrome. Sarcoidosis is now the most frequent cause of endogenous uveitis in our clinic. CONCLUSION: Not only does the etiological basis of uveitis vary with ethnicity, but advances in clinical and basic research have changed the approach to the diagnosis of uveitis, altering the etiological profile over time.

Adolescent↗

PubMed1996

Detection and immunolocalization of macrophage migration inhibitory factor in rat iris and ciliary epithelium.

To elucidate the role of macrophage migration inhibitory factor (MIF) in ocular inflammation, we examined the localization of MIF in the normal anterior uveal tract of rats. Immunohistochemistry using an anti-MIF antibody revealed that MIF was present in non-pigment epithelial cells of the ciliary body and the epithelial cells of the iris. Western blot analysis of these tissues showed a single band specific for MIF protein. The expression of MIF mRNA in these tissues was further confirmed by reverse transcription-polymerase chain reaction. Since MIF is known to be a potent proinflammatory cytokine, identification of the protein in iris and ciliary epithelial cells suggests the possibility that it may play an important role in ocular inflammation.

Animals↗

PubMed1996

Familial occurrence of Behçet's disease.

The familial occurrence of Behçet's disease in the 564 Behçet's patients treated in the Uveitis Survey Clinic of the Hokkaido University Hospital between 1967 and 1992 was investigated. Familial occurrence of Behçet's disease was found in 18 patients from 9 families. The male-to-female ratio was 3.5 in the familial cases, which was significantly higher than in the sporadic cases. Familial occurrence was most frequently seen among siblings. Most patients, including all female patients, had the complete type. They had typical ocular lesions, and exhibited bilateral uveoretinitis with poor visual prognosis, particularly the female patients. Frequency of HLA-B5 was 92% in the familial patients, which was much higher than in both the controls and the sporadic cases. It seems probable that patients with familial occurrence of this disease have a poorer prognosis with more susceptible immunogenetic backgrounds.

Adult↗

PubMed1996

[Behçet's disease and streptococcal antigens].

Many studies have been carried out concerning microbial infections and the occurrence of Behçet's disease. Recently, attention has been focused on the streptococci. The serum antibody titer and delayed type hypersensitivity of patients with Behçet's disease against streptococcal antigens were significantly higher than those of controls. We also found that the oral flora of patients with Behçet's disease was dominated by Streptococcus sanguis, whose serotypes were different from controls. Recent studies have revealed that some streptococcal antigens are associated with heat shock protein and that human gamma delta T cell lines recognize streptococcal antigens. These results suggest that an autoimmune response might be implicated in the etiology of Behçet's disease. To make clear autoimmune mechanisms of Behçet's disease, we have analysed immunogenic antigens of S. sanguis.

Amino Acid Sequence↗

PubMed1995

Characterization of Streptococcus sanguis isolated from patients with Behçet's disease.

The DNA homology and cell wall sugar constituents of eight Streptococcus sanguis(-like) strains, three isolated from the patients with Behçet's disease (BD114-23, BD113-20, BD118-1), two from patients with Kawasaki disease (MCLS-1, MCLS-2), and three type and reference strains of ATCC (ATCC10556T: S. sanguis, ATCC10557: S. oralis, and ATCC10558T: S. gordonii) were analyzed. Strains BD114-23 and BD118-1 showed high DNA homology to ATCC10556T, and their cell wall constituents were identical. Conversely, BD113-20, MCLS-1, MCLS-2, and ATCC10557 showed little DNA homology to ATCC10556T and ATCC10558T, but showed approximately 50 to 60% homology to each other. The cell wall constituents of BD113-20, MCLS-1, MCLS-2, and ATCC10557, however, were somewhat different, indicating that some of the clinical isolates have different characters from those of the three ATCC strains.

Behcet Syndrome↗

PubMed1995

Prevalence of antibodies against Borrelia species in patients with unclassified uveitis in regions in which Lyme disease is endemic and nonendemic.

We studied 93 patients with unclassified uveitis from two regions in Japan (Hokkaido and Kanagawa) to assess the contribution of Borrelia species to this condition. The seroprevalence of antibody to Borrelia species was higher in patients from Hokkaido than in those from Kanagawa. The unclassified uveitis of seropositive patients was probably a complication of Lyme borreliosis since (i) the antibody titers were as high as those in clinically diagnosed Lyme disease patients, (ii) healthy controls from Hokkaido showed low seroprevalence in contrast with unclassified uveitis patients from Hokkaido, and (iii) the reaction pattern of antibodies in sera from patients with unclassified uveitis was the same as that in patients with Lyme disease. This is the first report to reveal the high risk of Lyme borreliosis in patients with unclassified uveitis in regions endemic for Lyme disease. In case of unclassified uveitis as well as in cases of inflammatory disease of unknown origin, Lyme disease should be taken into consideration, especially in regions in which Lyme diseases is endemic, even if it is reported only in animals.

Animals↗