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Biomedical subjects

N Kamatani

Publications and source records attributed to N Kamatani.

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

Environmental factor dependent maximum likelihood method for association study targeted to personalized medicine.

The most challenging strategy for analyzing genome-wide polymorphisms and/or expression profiles is to solve multi-factor causal-relationship simultaneously. As the first step, we propose a framework of association study using maximum likelihood method that simultaneously handles genetic polymorphisms and epi-genetic information, e.g. environmental factors. We evaluate the theory by applying it to genotyped data of myocardial infarction (MI) patients.

Algorithms↗
PubMed1999

Influence of genotypes at SAA1 and SAA2 loci on the development and the length of latent period of secondary AA-amyloidosis in patients with rheumatoid arthritis.

To examine whether polymorphism at the SAA loci is associated with the development of amyloid protein A (AA)-amyloidosis, we determined the genotypes at the SAA1 and SAA2 loci in 43 AA-amyloidosis patients (amyloidosis population) and 77 patients with rheumatoid arthritis (RA) who had been ill for less than 5 years (early RA population). We also compared the frequencies of the genotypes at the SAA1 locus among 90 Korean, 95 Taiwanese, and 103 Japanese healthy subjects. The frequencies of the gamma/gamma genotype and gamma alleles at the SAA1 locus were significantly higher in the amyloidosis population than in the early RA population (34.9% versus 7.8%, and 58.1% versus 33.8%, chi2 test P=0.0001). The frequencies of the gamma allele at the SAA1 locus in Koreans, Taiwanese, and Japanese were 41.6%, 35.6%, and 37.4%, respectively. The length of the latent period of AA-amyloidosis was significantly longer in the patients with smaller numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: -0.42, P<0.05). On the other hand, the mean C-reactive protein (CRP) level during 2 years prior to the diagnosis of AA-amyloidosis was significantly higher in the patients with larger numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: 0.34, P<0.05). No significant association was found between amyloidosis and polymorphism at the SAA2 locus. We postulate that the allele SAA1gamma renders an RA patient susceptible to amyloidosis, possibly by affecting the severity of inflammation in RA.

Adult↗
PubMed1999

Radiopaque 2,8-dihydroxyadenine lithiasis.

2,8-Dihydroxyadenine (DHA) lithiasis is a rare type of urinary stone disease and the deficiency of adenine phosphoribosyltransferase (APRT) activity is known to be the cause of this disease. To identify a 2,8-DHA stone is important because this stone is well managed by medical therapy. Regarding a radiological finding, previous reports have considered 2,8-DHA to be radiolucent like uric acid stone. This report is a case of radiopaque 2,8-DHA stone and proposes that the composition of urinary stones should always be investigated for adequate medical treatment.

Adenine↗
PubMed1999

[A case of systemic lupus erythematosus complicated by Nocardia farcinica].

We report a patient with systemic lupus erythematosus (SLE) complicated with nocardiosis. This case is very important that the complication of nocardiosis in SLE is very rare and the treatment to both SLE and nocardiosis is very difficult. A twenty-one-year old female was admitted to our hospital because of thoracic empyema and active lupus nephritis. Her medical history revealed that the diagnose of SLE was made when she was 18 with lymphocytopenia, proteinuria, positive antinuclear antibodies, and high titer of antibodies to native DNA. She was treated with prednisolne 60 mg daily and became better. Proteinuria appeared again in September 1995 and she was admitted to the former hospital. Renal biopsy proved diffuse proliferative glomeluronephritis (WHO IVb). She was treated with 1 g per day of methylprednisolone for 3 days and succeeded with 60 mg day of prednisolone. In early November she developed left chest pain and fever and chest X-ray demonstrated left pleural effusion. Antibiotics, antituberculosis, and antifungal therapy failed to subside her pleuritis and it turned to empyema. Then she was transferred to our hospital for further treatment. Nocardia farcinica was detected from the aspirated pleural fluid obtained at the former hospital. Drainage and intrathoracic impenem injection were effective. While long usage of minocycline was continued for the nocardiosis, 500 mg of cyclophosphamide pulse therapy to lupus nephritis was administrated. Two weeks later a new pulmonary lesion with left chest pain and liver abscess developed. Administration of trimethoprim-sulfamethoxazole subsided the nocardiosis. She was discharged with 1 g per day of proteinuria the prescribed 13 mg per day of prednisolone and continuous TMP-SMZ intake for nocardial infection. When immunosuppressive therapy must be given to the immunocompromised host, a more potent therapy must be added to avoid infection.

Adult↗
PubMed1999

IL-17 in synovial fluids from patients with rheumatoid arthritis is a potent stimulator of osteoclastogenesis.

IL-17 is a newly discovered T cell-derived cytokine whose role in osteoclast development has not been fully elucidated. Treatment of cocultures of mouse hemopoietic cells and primary osteoblasts with recombinant human IL-17 induced the formation of multinucleated cells, which satisfied major criteria of osteoclasts, including tartrate-resistant acid phosphatase activity, calcitonin receptors, and pit formation on dentine slices. Direct interaction between osteoclast progenitors and osteoblasts was required for IL-17-induced osteoclastogenesis, which was completely inhibited by adding indomethacin or NS398, a selective inhibitor of cyclooxgenase-2 (COX-2). Adding IL-17 increased prostaglandin E2 (PGE2) synthesis in cocultures of bone marrow cells and osteoblasts and in single cultures of osteoblasts, but not in single cultures of bone marrow cells. In addition, IL-17 dose-dependently induced expression of osteoclast differentiation factor (ODF) mRNA in osteoblasts. ODF is a membrane-associated protein that transduces an essential signal(s) to osteoclast progenitors for differentiation into osteoclasts. Osteoclastogenesis inhibitory factor (OCIF), a decoy receptor of ODF, completely inhibited IL-17-induced osteoclast differentiation in the cocultures. Levels of IL-17 in synovial fluids were significantly higher in rheumatoid arthritis (RA) patients than osteoarthritis (OA) patients. Anti-IL-17 antibody significantly inhibited osteoclast formation induced by culture media of RA synovial tissues. These findings suggest that IL-17 first acts on osteoblasts, which stimulates both COX-2-dependent PGE2 synthesis and ODF gene expression, which in turn induce differentiation of osteoclast progenitors into mature osteoclasts, and that IL-17 is a crucial cytokine for osteoclastic bone resorption in RA patients.

Animals↗
PubMed1999

Responsiveness of peripheral blood B cells to recombinant CD40 ligand in patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the immunopathological significance of CD40/CD40 ligand system for B cell hyperactivation in SLE patients, the expression and the function of CD40 on B cells were compared with those of normal controls. METHODS: Expression of CD40 was evaluated by flow cytometry. DNA synthesis of B cells were measured by 3H - TdR incorporation. Antibody production was assessed by ELISA. RESULTS: There was no significant difference between SLE and normal controls in CD40 expression on peripheral blood B cells. Recombinant CD40 ligand-leucine zipper fusion protein (CD40L-LZ) significantly enhanced 3H - TdR incorporation by both SLE and normal B cells (P<0.01). 3H - TdR incorporation of SLE B cells without stimuli (P<0.001) and with CD40L-LZ stimulation (P<0.05) were significantly lower in SLE patients compared with normal controls. Active SLE B cells spontaneously produced significantly larger amounts of total IgG than normal B cells (P<0.05). CD40L-LZ significantly increased the production of total IgG by SLE B cells (P<0.05), but not by normal B cells. Active SLE B cells spontaneously produced IgG anti-dsDNA and IgG anti-ssDNA antibodies. CD40L-LZ significantly increased the production of these autoantibodies by SLE B cells (P<0.05). B cells from normal controls do not produce these autoantibodies spontaneously nor in response to CD40L-LZ. CONCLUSION: These findings indicate that signalling via CD40 plays an important role in B cell proliferation and autoantibody production in human SLE.

Autoantibodies↗
PubMed1999

[MPO-ANCA positive rapidly progressive glomerulonephritis in a patient with rheumatoid arthritis during treatment with D-penicillamine].

We present here a case of MPO-ANCA positive rapidly progressive glomerulonephritis (RPGN) after 34 months of D-penicillamine (D-PC) therapy for rheumatoid arthritis (RA). A 27-year-old Japanese woman was diagnosed as having RA in June 1994 at our out-patient clinic. Oral D-PC administration was initiated at a dose of 100 mg per day in January 1995. In August 1997, proteinuria, hematuria, renal insufficiency, and anemia developed. D-PC was withdrawn promptly, and prednisolone 5 mg per day was started. The patient was admitted to our hospital in September. On admission, anti-neutrophil cytoplasmic antibody against mycloperoxidase (MPO-ANCA) was strongly positive in the serum. Renal biopsy showed glomerulonephritis with cellular crescent formation in 60% of the glomeruli observed. Immunofluorescence examinations revealed deposits of granular IgG, IgA, C 1 q, and C 3 in the mesangium. The patient was treated with steroid pulse therapy along with administration of anti-coagulation and anti-platelet agents under the diagnosis of MPO-ANCA positive D-PC-induced RPGN. The renal function was gradually recovered and MPO-ANCA disappeared. Since RPGN is potentially a fatal disease, frequent monitoring of renal function and discontinuation of D-PC are required. In case MPO-ANCA becomes positive, prompt and correct diagnosis of the renal disorder could lead to a good prognosis as in this case. The present case may provide some important immunological insights into medical procedures to treat D-PC-induced RPGN and MPO-ANCA related glomerulonephritis.

Adult↗
PubMed1999

[A case of microscopic polyangiitis with severe cardiac and respiratory muscle involvement].

A 66-year-old female was admitted to our hospital in January, 1998, complaining of low grade fever and muscle weakness of her legs. Physical examination revealed muscle weakness of her neck (4/5) and proximal skeletal muscles of her bilateral legs (3/5-4/5). She showed proteinuria and microhematuria. Her serum levels of ureanitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase, creatinekinase, aldolase and myoglobin were all within the normal ranges. Antinuclear antibodies were negative, but her serum levels of pANCA (743 EU) and C reactive protein (18.0 mg/dl) were elevated. Neuroconduction velocity of her left common peroneal nerve was decreased to 40.8 m/sec and electric myograph showed neurogenic changes. Magnetic resonance images (MRI) of her bilateral thigh depicted high signal intensity in quadriceps by T 2 weighed images, but the signals were not enhanced by gadolinium injection. Muscle and renal biopsies revealed necrotizing vasculitis of the small arteries. Crescentic glomerulonephritis was also observed by renal biopsy. These findings supported the diagnosis of microscopic PN. On 16 th admission day, she developed acute cardiac and respiratory failures due to cardiac and respiratory muscle involvements with PN, and was assisted by mechanical ventilation. She was treated with methylprednisolone pulse therapy (500 mg/day, three consecutive days) on 18 th admission day, followed by 40 mg of oral prednisolone daily. However, her symptoms deteriorated, and herserum creatinine levels increased to 2.4 mg/dl. On 24 th admission day, intravenous cyclophosphamide pulse therapy (500 mg/day) was instituted. Her cardiac wall motion on echocardiography and serum creatinine levels gradually improved, but her skeletal and respiratory muscle weakness did not improve. On 38 th admission day, she was complicated with respiratory infection by methicillin resistant Staphylococcus aures. On 62 th admission day, she died of endotoxic shock. This is the first report describing respiratory muscle involvement with PN, and the second report describing MRI findings of muscle involvement by PN. Therefore, our case provides important clinical information for the diagnosis and treatment of the disease.

Aged↗
PubMed1999

[Nation-wide survey for the treatment with cyclosporin A of interstitial pneumonia associated with collagen diseases].

OBJECTIVES: This study was performed to investigate the efficacy and safety of cyclosporin A (CsA) for the treatment of interstitial pneumonia (IP) associated with collagen diseases in Japan. METHODS: Questionnaires were sent to 36 hospitals specializing in collagen diseases. RESULTS: Fifty-eight patients (7 polymyositis (PM), 19 dermatomyositis (DM), 7 systemic sclerosis (SSc), 7 rheumatoid arthritis (RA), 2 mixed connective tissue disease (MCTD), 1 systemic lupus erythematosus (SLE) and 1 Sjögren's syndrome (SS), 1 RA + SSc, 2 PM + SSc, 1 DM + SLE, and 10 idiopathic interstitial pneumonia (IIP) with IP were treated with CsA at 14 hospitals. IP was classified into the acute or chronic type. In the PM/DM group (7 PM, 19 DM, 2 PM + SSC, 1 DM + SLE), 65.5% were the acute type. In the other collagen disease group (7 SSc, 7 RA, 2 MCTD, 1 SLE, 1 SS, and 1 RA + SSc) and IIP group, 36.8% and 50% were the acute type, respectively. Mean dosages of CsA were 3.7 +/- 1.3 mg/kg/day for the PM/DM group, 3.0 +/- 1.0 for the other collagen disease group, and 3.8 +/- 4.8 for the IIP group. Oral corticosteroids were administered in combination with CsA in 100, 73.7, and 70% of the patients with PM/DM, other collagen disease, and IIP groups, respectively. CsA was effective for 72.2, 33.3, and 25% of the acute IP cases in the PM/DM, other collagen disease, and IIP groups, respectively. CsA was effective for 50.0, 50.0, and 60.0% of chronic IP cases in the PM/DM, other collagen disease, and IIP groups, respectively. Twenty-three adverse effects were observed, but most of them ameliorated upon withdrawal or reduction of the CsA dose. CONCLUSION: CsA is effective for the treatment of acute type IP associated with collagen diseases, especially PM/DM. To perform a prospective multi-center trial, standards for the recruitment of patients, efficacy assessments, and trial course and treatment should be determined carefully.

Anti-Inflammatory Agents↗
PubMed1998

Optimal range of serum urate concentrations to minimize risk of gouty attacks during anti-hyperuricemic treatment.

To find an optimal range of urate concentrations wherein the risk of attacks during the initial 6 months of treatment is minimized, data from 350 gouty patients treated with anti-hyperuricemic drugs were retrospectively analyzed. We determined the optimal range of urate concentrations to be 4.6-6.6 mg/dl. If urate concentrations were within this range, the risk ratio of an attack as opposed to outside of the range was 0.705 (95% confidence interval, 0.629-0.791). The increase (or decrease) in urate concentration in one month associated with minimal risk of gouty attacks was also determined. The lowest risk ratio of attack (0.451) occurred at a range of -0.1 to 0.6 mg/dl/month increase in urate concentrations (95% confidence interval, 0.310-0.655). In conclusion, we propose that urate concentrations during the initial 6 months of anti-hyperuricemic therapy should be maintained within a range of 4.6-6.6 mg/dl, and reduction in the urate concentrations during treatment should be as slow as possible.

Biomarkers↗
PubMed1998

A germline mutation abolishing the original stop codon of the human adenine phosphoribosyltransferase (APRT) gene leads to complete loss of the enzyme protein.

Adenine phosphoribosyltransferase (APRT) is a purine metabolic enzyme and a homozygous deficiency in this enzyme causes 2,8-dihydroxyadenine urolithiasis. Various germline abnormalities have been described, but we report here a unique type of germline mutation in a homozygous individual (SY) who had excreted 2,8-dihydroxyadenine crystals. In SY, TCA was substituted for the physiological stop codon TGA. This base substitution generates a new HinfI restriction site, and, using the polymerase chain reaction and subsequent digestion by this enzyme, it was confirmed that SY is homozygous for the base substitution. This base change is unique in that it generates an open reading frame that extends to the poly(A) addition site. The amount of mRNA in transformed B cells from SY was approximately a quarter of that in control subjects and no APRT proteins were detected. In eukaryotes, unlike in prokaryotes, no rescue systems for defective polypeptide termination caused by a missing stop codon have been found. Therefore, the outcome of the defect of SY is unclear from present knowledge about termination of polypeptide synthesis. Investigations into the mechanisms of the absence of protein in the cells of SY may lead to a better understanding of the physiological and nonphysiological termination of polypeptide synthesis in eukaryotic cells.

Adenine Phosphoribosyltransferase↗
PubMed1998

Identification of the gene loci that predispose to rheumatoid arthritis.

We have searched the human genome for genes that predispose to rheumatoid arthritis (RA) using fluorescence-based microsatellite marker analysis and affected sib-pair linkage study. A panel of 41 Japanese families, each with at least two affected siblings, was typed for genome-wide 358 polymorphic microsatellite marker loci. Markers were amplified by the PCR using fluorescence-tagged primers and sized based on the difference of CA repeats on DNA. Linkage analysis was made using maximum lod score (MLS). The MLS for D1S214 and D8S556 was 3.27 and 3.33, while the MLS for the HLA-DRB1 region was <3.0. According to detailed analysis by single-point analysis using MAPMAKER/SIBS, the MLS for D1S253 and D1S214 was 3.77 and 3.58. The MLS by multipoint analysis was 6.13 for D1S253. The MLS for D8S556 by single-point analysis was 4.20. The MLS for DXS1232 was 2.35 by single-point analysis, whereas the MLS for the region 2 cM right to DXS1232 and the region between DXS1227 and DXS1200 was 3.03 and 2.93 by multi-point analysis. Three principal chromosome regions of linkage, D1S253/214, D8S556 and DXS1232, have been identified which we call RA1, RA2 and RA3 for RA disease loci.

Arthritis, Rheumatoid↗
PubMed1998

Multiple extra-articular synovial cyst formation: case report and review of the literature.

OBJECTIVE: To investigate the clinical manifestations and the treatment strategy of a very rare entity of disease manifesting as multiple extra-articular cystic synovitis with recurrent polyarthralgia. METHODS: A 47 year old male patient with multiple extra-articular synovial cysts was followed up prospectively for 13 years. The clinical manifestations and response to various treatments were recorded. Comparisons are made among the five reported cases (including the present case). RESULTS: Multiple synovial cysts over the tendon sheath and bursae appeared successively with and without antecedent growth of nodules during 13 years of follow up. Although polyarthralgia and high titred rheumatoid factor persisted throughout the course, there were no roentgenographical changes of joints specific to rheumatoid arthritis (RA). The synovial cysts and arthralgia failed to respond to any of the disease modifying anti-rheumatic drugs (DMARDs) prescribed. Systemic involvements such as pulmonary interstitial fibrosis and skin ulcers were also noted, but they were not progressive. CONCLUSIONS: Multiple extra-articular cystic synovitis is an uncommon disease entity closely related to RA. It has been reported exclusively in Japanese subjects and therefore some cultural factors, either genetic or environmental, may contribute to its development.

Antirheumatic Agents↗