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Biomedical subjects

Y Takasaki

Publications and source records attributed to Y Takasaki.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Microscopic polyangiitis accompanying interstitial pneumonia with aluminum lung].

A 67-year-old man who had worked as an aluminum grinder had been given a diagnosis of pneumoconiosis. Ten years later, he was admitted with fever, dyspnea on exertion, and numbness. Chest roentgenograms showed linear-reticular shadows in both lower lung fields. ELISA-based tests were positive for perinuclear anti-neutrophil cytoplasmic antibody (P-ANCA). Renal biopsy specimens disclosed crescentic glomerulonephritis and angiitis of small arteries. Our diagnosis was microscopic polyangiitis accompanying interstitial pneumonia with aluminum lung. The results of high-energy dispersion X-ray microanalysis indicated that the patient's lungs contained aluminum. His general condition improved with the administration of corticosteroid and immunosuppressive agents, and his chief symptoms disappeared.

Aged↗
PubMed2000

[Polysomnography].

Polysomnography(PSG) is essential for the diagnosis of all pathophysiologic conditions due to both any types of sleep disordered breathing and to any types of sleep disturbance. Since this issue's objection is to describe the outline of PSG, we will explain here about when PSG is needed, what type of measurements are necessary for PSG, and how it should be interpreted from the result of the PSG tracing for the diagnosis for sleep apnea syndrome, etc.

Diagnosis, Differential↗
PubMed2000

[Objective evaluation of treatment for sleep apnea syndrome].

CPAP treatments for sleep apnea syndrome (SAS) are being established; however, there is no established evaluation method to scale the long-lasting effectiveness of the treatment. The only available method is to judge the results from each patient's subjective symptoms. We therefore tested a self-contained microcomputer with an acceleration sensor (Lifecorder) in an attempt to evaluate the effectiveness of treatments objectively. Fifteen patients with OSAS were the subjects. We keep the records of Lifecorders that were worn by the subjects a month before and a month after nasal CPAP treatment. We also assessed their daily physical activity levels; the number of steps taken, calories consumed, intensity of each activity along with improvement in their subjective symptoms. The number of steps taken in a day increased as did the calories consumed after treatment in 9 subjects. Moderate and intensive activities also increased among those 9 subjects. Our results indicate that evaluation with a Lifecorder, which is simple and inexpensive, can provide objective indicators to assess the effectiveness of treatments in patients' daily activities.

Adult↗
PubMed1999

A critical evaluation of enzyme immunoassays for detection of antinuclear autoantibodies of defined specificities. I. Precision, sensitivity, and specificity.

OBJECTIVE: To determine the performance characteristics of enzyme-based immunoassay (EIA) kits for the detection of antinuclear and other autoantibodies of defined specificities. METHODS: Nine manufacturers of EIA kits to detect antibodies of defined specificities participated in a study in which they received coded sera from the Centers for Disease Control and Prevention. These coded sera contained different dilutions of antibody of one specificity mixed with sera containing antibodies of other specificities. The manufacturers were asked to use their standard technology to determine antibody content and send the data to a committee of the International Union of Immunological Societies for analysis. The data were analyzed for sensitivity and specificity in the detection of anti-double-stranded DNA (anti-dsDNA), anti-single-stranded DNA, antihistone, anti-Sm, anti-U1 RNP, anti-SSA/Ro, anti-SSB/La, anti-Scl-70 (DNA topoisomerase I), anticentromere, and anti-Jo-1 antibodies. In addition, replicate samples were included in the coded sera to evaluate the precision of each EIA method. RESULTS: Lack of sensitivity and specificity was most evident in the anti-dsDNA and anti-Sm kits, although 2 kits for anti-dsDNA achieved acceptable sensitivity and specificity. Generally, anti-SSA/Ro, anti-SSB/La, anti-Scl-70, anticentromere, and anti-Jo-1 kits performed well. Many false-positive results were obtained with a multiple myeloma serum containing cryoprecipitates, but multiple myeloma sera without cryoprecipitates presented no problem in the EIA system. Precision, based on evaluation of replicate samples, varied from very good to poor. CONCLUSION: No single manufacturer was clearly superior to others in terms of their products' overall sensitivity, specificity, and precision. Areas that needed improvement were in kits for the detection of antibodies to dsDNA and to Sm antigen. Some EIA kits achieved good sensitivity and specificity. Individual manufacturers were informed of the performance of their respective kits so they could take measures to correct perceived deficiencies and thus improve the reliability of a group of important diagnostic assays used in the evaluation of systemic rheumatic diseases.

Antibodies, Antinuclear↗
PubMed1999

Expression of CD80 and CD86 on peripheral blood T lymphocytes in patients with systemic lupus erythematosus.

CD80 and CD86 were detected in high amounts on circulating T cells in the peripheral blood of some patients with systemic lupus erythematosus (SLE), using flow cytometry and monoclonal antibodies. Patients with other connective tissue diseases did not have a high percentage of T cells expressing CD80 or CD86 in their peripheral blood. CD80 was expressed mainly on CD4 T cells, whereas CD86 was expressed on CD8 T cells, and these two populations were associated with particular clinical features. These two molecules were expressed on different T-cell populations and might have different roles in the generation and regulation of immune responses. Since high expression of CD86 on T cells was detected much earlier than the appearance of clinical features and a high titer of anti-DNA antibody, it may be a useful parameter for predicting the flare of SLE.

Adult↗
PubMed1999

Levels of IL-12 in the sera of patients with systemic lupus erythematosus (SLE)--relation to Th1- and Th2-derived cytokines.

IL-12 is a cytokine that induces Th1-derived cytokines (interferon-gamma (IFN-gamma) and IL-2). The significance of IL-12 in human autoimmunity is no clear, and the serum levels of IL-12 in SLE are not clearly established. Therefore, we examined the levels of IL-12 in 39 patients with active SLE, with sandwich ELISA. The levels of IL-12 in patients were significantly higher than in normal subjects. Patients with high levels of IL-12 also had high levels of IFN-gamma, while their levels of IL-13 were significantly lower than in patients with normal levels of IL-12. Patients with pulmonary involvement had high levels of IL-12, and steroid therapy decreased the IL-12 level in three patients. In a retrospective study of seven patients, various changes of IL-12 and IL-13 were recognized before disease flare. Thus, in SLE patients, the level of IL-12 was increased and this increase was related to the change of Th1- or Th2-derived cytokines with some organ involvement.

Adult↗
PubMed1999

Crystal structure of beta-amylase from Bacillus cereus var. mycoides at 2.2 A resolution.

The crystal structure of beta-amylase from Bacillus cereus var. mycoides was determined by the multiple isomorphous replacement method. The structure was refined to a final R-factor of 0.186 for 102,807 independent reflections with F/sigma(F) > or = 2.0 at 2.2 A resolution with root-mean-square deviations from ideality in bond lengths, and bond angles of 0.014 A and 3.00 degrees, respectively. The asymmetric unit comprises four molecules exhibiting a dimer-of-dimers structure. The enzyme, however, acts as a monomer in solution. The beta-amylase molecule folds into three domains; the first one is the N-terminal catalytic domain with a (beta/alpha)8 barrel, the second one is the excursion part from the first one, and the third one is the C-terminal domain with two almost anti-parallel beta-sheets. The active site cleft, including two putative catalytic residues (Glu172 and Glu367), is located on the carboxyl side of the central beta-sheet in the (beta/alpha)8 barrel, as in most amylases. The active site structure of the enzyme resembles that of soybean beta-amylase with slight differences. One calcium ion is bound per molecule far from the active site. The C-terminal domain has a fold similar to the raw starch binding domains of cyclodextrin glycosyltransferase and glucoamylase.

Amino Acid Sequence↗
PubMed1999

Intracellular redistribution of truncated La protein produced by poliovirus 3Cpro-mediated cleavage.

The La autoantigen (also known as SS-B), a cellular RNA binding protein, may shuttle between the nucleus and cytoplasm, but it is mainly located in the nucleus. La protein is redistributed to the cytoplasm after poliovirus infection. An in vitro translation study demonstrated that La protein stimulated the internal initiation of poliovirus translation. In the present study, a part of the La protein was shown to be cleaved in poliovirus-infected HeLa cells, and this cleavage appeared to be mediated by poliovirus-specific protease 3C (3Cpro). Truncated La protein (dl-La) was produced in vitro from recombinant La protein by cleavage with purified 3Cpro at only one Gln358-Gly359 peptide bond in the 408-amino-acid (aa) sequence of La protein. The dl-La expressed in L cells was detected in the cytoplasm. However, green fluorescence protein linked to the C-terminal 50-aa sequence of La protein was localized in the nucleus, suggesting that this C-terminal region contributes to the steady-state nuclear localization of the intact La protein in uninfected cells. The dl-La retained the enhancing activity of translation initiation driven by poliovirus RNA in rabbit reticulocyte lysates. These results suggest that La protein is cleaved by 3Cpro in the course of poliovirus infection and that the dl-La is redistributed to the cytoplasm. dl-La, as well as La protein, may play a role in stimulating the internal initiation of poliovirus translation in the cytoplasm.

3C Viral Proteases↗
PubMed1999

Met5-enkephalin protects isolated adult rabbit cardiomyocytes via delta-opioid receptors.

In rats and rabbits, endogenous opioid peptides participate in ischemic preconditioning. However, it is not known which endogenous opioid(s) can trigger cardioprotection. We examined preconditioning-induced and opioid-induced limitation of cell death in isolated, calcium-tolerant, adult rabbit cardiomyocytes. Cells were subjected to simulated ischemia by pelleting and normothermic hypoxic incubation. Preconditioning was elicited with 15 min of simulated ischemia followed by 15 min of resuspension and reoxygenation. All cells underwent 180 min of simulated ischemia. Cell death was assessed by trypan blue permeability. Morphine protected cells, as did preconditioning; naloxone blocked the preconditioning-induced protection. Exogenous Met5-enkephalin (ME) induced protection, but exogenous beta-endorphin did not. ME-induced protection was blocked by the delta-selective antagonist naltrindole. Additionally, two other proenkephalin products, Leu5-enkephalin and Met5-enkephalin-Arg-Phe, provided protection equipotent to ME. These data suggest that one or more proenkephalin products interact with delta-opioid receptors to endogenously trigger opioid-mediated protection.

Animals↗
PubMed1999

Site-directed mutagenesis of restriction endonuclease HindIII.

Site-directed mutagenesis by inverse PCR was done on the HindIII gene. Target residues to be mutated were chosen according to (i) the fact that a mutant obtained by sodium nitrite treatment showed almost no HindIII activity, where Asp-123 was replaced with Asn, and (ii) the model proposed by Stahl et al. (Stahl, F., Wende, W., Jeltsch, A. and Pingoud, A. Biol. Chem. 379, 467-473 (1998)). Seven kinds of mutants were obtained by the PCR, and their enzymatic and biochemical properties were examined. Three mutants, P50S, D108L, and D123N, showed fairly low HindIII activity. On the other hand, the other four, P84Q, E86K, V106E, and K125N, retained the activity. In particular, E86K showed higher activity than the wild enzyme. This fact was confirmed when activities of the purified wild and E86K enzymes were assayed. These results coincided fairly well with data using E. coli strains that carry the respective mutant plasmids, on their resistance to phage T7 and on growth rate. We conclude that the PE motif at residues 50 and 51, and DXK motif at residues 108-110, are responsible for the enzymic reaction of HindIII.

Amino Acid Sequence↗
PubMed1999

Repair of the mandibular nerve by autogenous grafting after ablative surgery of the mandible.

In this paper, we introduce our original method of autologous nerve grafting for substitution of the mandibular nerve after mandibular resection in three subjects. The lateral cutaneous nerve of the forearm served as a donor nerve, and the graft was imbedded microsurgically at the junctures using an epineurial nerve suture technique. Oversized grafts were chosen in order to insert them without tension in a space between the stumps of the recipient nerve and the regeneration zone of the bone. In all three subjects, sensibility of the lower lip and chin recovered completely after about ten months.

Case-Control Studies↗
PubMed1999

[Plasmapheresis for collagen diseases].

Recently plasmapheresis has been performed for connective tissue disease. Double-filtration plasmapheresis (DFPP) has mainly been performed for rheumatoid arthritis (RA) and systemic lupus erythematosus (SEL) since 1980. In DFPP, autoantibodies and immune complex are removed by the second filter. The adaptation of plasmapheresis is commonly for cases (1) which are resistant to some medications, (2) which have a high titer of antibodies or immune complex, (3) in which the medication must be decreased or stopped because of side effects and complications, or (4) which are in the acute active phase. We suggest DFPP to be useful as a treatment for connective tissue disease.

Antigen-Antibody Complex↗
PubMed1999

Circulating levels of beta-chemokines in systemic lupus erythematosus.

OBJECTIVE: Recent evidence suggests the role of beta-chemokines and their receptors in human immunodeficiency virus infection. We examined the serum levels of beta-chemokines in patients with systemic lupus erythematosus (SLE). METHODS: The serum levels of beta-chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, RANTES, and monocyte chemoattractant protein-1 (MCP-1) in patients with SLE were determined by ELISA. RESULTS: There were significant differences between the patients with SLE and healthy controls in the serum concentrations of RANTES (p < 0.001) and MCP-1 (p < 0.01), but not MIP-1alpha (p = 0.07) and MIP-1beta (p = 0.68). A decrease of RANTES and an increase of MCP-1 was observed with the progression of disease activity in the patients with SLE. CONCLUSION: Changes in the serum levels of RANTES and MCP-1 may indicate an interaction between SLE disease activity and the production of beta-chemokines.

Adolescent↗
PubMed1999

[Chlamydia-induced reactive arthritis--HLA-B 27 negative two patients].

Two cases with HLA-B 27 negative, Chlamydia-induced reactive arthritis (ReA) were described. Case 1: A 30 y.o. male developed balanitis, urethritis, arthritis of both knees, elbows, shoulders and hip joints on May in 1997. Laboratory findings revealed CRP 2.7 mg/dl (normal range < 0.3), ESR 33 mm/h and negative rheumatoid factor (RF) test. Anti-Chlamydia trachomatis antibodies, IgG 2.22, IgA 3.33 were positive. HLA-typing revealed A 2, A 24 (9), B 39 (16), B 52 (5). He was diagnosed as ReA and arthritis subsided with treatment of minocycline and nonsteroidal antiinflammatory drugs (NSAIDs). Case 2: A 40 y.o. Iranian American male developed balanitis, urethritis, lumbago, arthritis of both elbows, knees and foot joints, iridocyclitis on August in 1995. Chlamydia trachomatis was detected in the urethral swab culture. He was diagnosed as ReA and treated with minocycline and NSAIDs. He was referred to our hospital on June in 1996. Arthritis at both knees and feet was detected. Laboratory findings revealed CRP 0.8 mg/dl, negative RF test was revealed. Antibodies to Chlamydia were positive (IgG 1.49, IgA 1.53) positive. HLA typing revealed A 1, A 2, B 37, B 55 (22). He was again treated with minocycline and NSAIDs and ReA ameliorated. Since HLA-B 22, B 37 and B 39 have been reported to cross-react or to have homology with B 27, B 22, B 37 and B 39 are likely to related to inducing ReA.

Adult↗
PubMed1999

Immunological analysis of pulmonary hypertension in connective tissue diseases.

OBJECTIVE: To analyze the immunological characteristics of the sera of patients with inflammatory connective tissue diseases complicated by pulmonary hypertension (PH). METHODS: Sera of 24 patients with mixed connective tissue disease complicated by PH (MCTD-PH), sera of 11 patients with other connective tissue diseases complicated by PH (Other-PH; 6 systemic sclerosis, 3 systemic lupus erythematosus, 2 rheumatoid arthritis), and sera of 15 patients with MCTD not complicated by PH (MCTD-non-PH) were tested for IgG antibodies against U1RNP proteins, U1RNP-70K protein, U1RNP-A protein, and U1RNP-C protein, and for IgG and IgM antibodies to beta2-glycoprotein I dependent cardiolipin (CL) and human umbilical vein endothelial cells. We also measured the serum levels of von Willebrand factor related antigens and interleukin 6 (IL-6). RESULTS: (1) The titers of the anti-U1RNP, anti-U1RNP-70K, anti-U1RNP-A, and anti-U1RNP-C antibodies were significantly higher in the MCTD-PH and MCTD-non-PH groups than in the Other-PH group. However, there were no statistically significant differences in the titers of these 4 antibodies between the MCTD-PH and MCTD-non-PH groups. (2) The titers of the IgG aCL and the serum IL-6 levels were significantly higher in the MCTD-PH group than in the MCTD-non-PH group. (3) Statistically significant correlations between the anti-U1RNP and IgG anti-CL antibody titers, and between the IgG anti-endothelial cell and IgG anti-CL antibody titers were observed within the MCTD-PH and Other-PH groups, but not within the MCTD-non-PH group. CONCLUSION: The occurrence of anti-U1RNP, anti-endothelial cell, and anti-CL antibodies is associated with PH in certain patients with connective tissue disease.

Autoantibodies↗
PubMed1999

[Churg-Strauss syndrome with pulmonary eosinophilia and intrapulmonary lymph nodes 2 years before the onset of vasculitis].

We report a case of a 55-year-old man who had been treated for bronchial asthma diagnosed at the age of 51. One year following diagnosis, chest X-ray films disclosed nodular shadows. Biopsy specimens obtained by video-assisted thoracoscopic surgery were histopathologically identified as intrapulmonary lymph nodes. Three years after the initial diagnosis, the patient experienced sensory disturbance of the lower extremities, low-grade fever, and weight loss. At this point he was admitted to our hospital. On admission, physical examination and clinical investigations showed peripheral eosinophilia and signs of vasculitis. Specimens obtained by transbronchial lung biopsy and bronchoalveolar lavage showed strong evidence of tissue damage with infiltration of eosinophils but no evidence of necrotizing vasculitis or extra-vascular granuloma. Churg-Strauss syndrome (CSS) was diagnosed, and treatment was initiated with prednisolone at a dose of 60 mg/day. Except for the sensory disturbances in the lower extremities, after a few days of treatment the patient's symptoms subsided and his clinical data improved. This case was clinically important because pulmonary eosinophilic infiltration into vessel walls was confirmed a year after the diagnosis of bronchial asthma, and 2 years before the patient demonstrated signs of vasculitis. Further, it was a very rare case of CSS in which intrapulmonary lymph nodes had developed beneath the visceral pleura despite the absence of a history of heavy smoking, thus suggesting continuous stimulation by some as yet unknown antigen.

Asthma↗