C and V proteins of Sendai virus target signaling pathways leading to IRF-3 activation for the negative regulation of interferon-beta production

We here report a molecular basis for downregulation of interferon (IFN)-beta production by V and C proteins of Sendai virus (SeV). The infection of HeLa cells with SeV poorly induced IFN-beta even if the expression of C/C' was disrupted. In contrast, when the expression of C/C'/Y1/Y2 or V/W was disrupted, SeV infection strongly induced IFN-beta production and significantly activated the interferon regulatory factor (IRF)-3 pathway. The independent expression of C or V inhibited the double-stranded (ds) RNA- or Newcastle disease virus (NDV)-induced activation of IRF-3 and NF-kappa B, as well as the IFN-beta promoter. This inhibitory effect was also observed when Y1, Y2, or a C-terminal half fragment (aa 85-204) of C was independently expressed. Phosphorylation and homodimer formation of IRF-3 were suppressed not only in cells infected with SeV capable of expressing both C/C'/Y1/Y2 (or Y1/Y2) and V/W, but also in HeLa cells constitutively expressing Y1. These results suggest that C, Y1, Y2, and V block signaling pathways leading to IRF-3 activation to downregulate IFN-beta production.     

Practical application of nutritional assessment protein and inflammatory marker in the nutrition support team (NST)

Recently nutrition support team (NST) has been established for the purpose of prevention of complications which are caused by nutrition disorders and reduction of the medical expenses. Although physical examinations and blood biochemical data had been used as the indexes evaluating nutritional of patients, they were not suitable for the evaluation for the short-term in-patient. On the contrary, serum albumin (ALB) has been wildly used as a nutritional marker. However, it is impossible to evaluate nutrition state for the short-term in-patient and acute phase disease patient accurately, because the plasma half-life is 21 days and it takes long time to detect the change in nutritional state by its value. Rapid turnover proteins (RTP), whose plasma half-life is shorter, has paid attention to evaluate nutritional state for the short-term in-patients and acute phase disease patients. Although, prognostic inflammatory and nutritional index (PINI) was considered as a useful maker for evaluating inflammatory and nutritional states using the concentrations of transthyretin (TTR), a RTP, alpha1-acid glycoprotein (alpha1-AG), a chronic inflammation marker, C reactive protein (CRP), a acute inflammation marker, and ALB, However, it has several pitfalls. We newly made serum amyloid A (SAA) index using SAA instead of CRP. When we compared SAA index with PINI in many diseases, it turned out that SAA index became a more effective index which reflected the patient condition than did PINI. As for this index, it is expected to be used by NST while further alternation may be needed.     

Gain-of-function polymorphism in mouse and human Ltk: implications for the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE), a complex multigenic disease, is a typical antibody-mediated autoimmune disease characterized by production of autoantibodies against a variety of autoantigens and immune complex-type tissue inflammation, most prominently in the kidney. Evidence suggests that genetic factors predisposing to aberrant proliferation/maturation of self-reactive B cells initiate and propagate the disease. In SLE-prone New Zealand Black (NZB) mice and their F1 cross with New Zealand White (NZW) mice, B cell abnormalities can be ascribed mainly to self-reactive CD5+ B1 cells. Our genome-wide scans to search for susceptibility genes for aberrant activation of B1 cells in these mice showed evidence that the gene, Ltk, encoding leukocyte tyrosine kinase (LTK), is a possible candidate. LTK is a receptor-type protein tyrosine kinase, belonging to the insulin receptor superfamily, and is mainly expressed in B lymphocyte precursors and neuronal tissues. Sequence and functional analyses of the gene revealed that NZB has a gain-of-function polymorphism in the LTK kinase domain near YXXM, a binding motif of the p85 subunit of phosphatidylinositol 3-kinase (PI3K). SLE patients also had this type of Ltk polymorphism with a significantly higher frequency compared with the healthy controls. Our findings suggest that these polymorphic LTKs cause up-regulation of the PI3K pathway and possibly form one genetic component of susceptibility to abnormal proliferation of self-reactive B cells in SLE.     

Application of Scanning Acoustic Microscopy for Assessing Stress Distribution in Atherosclerotic Plaque

Scanning acoustic microscopy (SAM) was equipped to assess the acoustic properties of normal and atherosclerotic coronary arteries. The SAM image in the atherosclerotic lesion clearly demonstrated that the sound speed was higher than that in the normal intima, and that the variation of elasticity was found within the fibrous cap of the plaque. Young's elastic modulus of each region was calculated and the finite element analysis was applied to derive the stress distribution in these arterial walls. In a case of normal coronary artery, the stress was dominant in the intima and the distribution was rather homogeneous and in a case of atherosclerosis, high stress was concentrated to the relatively soft lesion in the fibrous cap overlying lipid pool. SAM provides information on the physical properties, which cannot be obtained by the optical microscope. The results would help in understanding the pathological features of atherosclerosis. © 2001 Biomedical Engineering Society. PAC01: 8764-t, 8763Df, 8719Xx, 8719Rr     

Functional CD4+T cell subsets defined by expression of CD45RC and NTA260 antigens and age-associated polarization in murine lupus

Using two mAb, one specific to the alternative exon 6-dependentepitope of CD45 molecules(JH6.2) and one a natural thymocytotoxicautoantibody (NTA) with an unknown reactive epitope (NTA260),we subdivided splenic CD4⁺ T cells from 2-month-old BALB/c miceinto five phenotypically distinct subsets. CD45RC⁺NTA260^–(SI) cells were phenotypically analogous to CD4⁺ T cells predominatingin newborn mice and produced a significant amount of IL-2, butnot so IL-4, IL-10 or IFN- when stimulated with immobilizedanti-CD3 mAb in vitro. They appeared to consist mainly of naiveT_hP cells. The CD45RC⁺;NTA260⁺ (S II) subset also produced IL-2,but not other cytokines; however, the IL-2 levels produced weremuch higher than seen with the S I subset, thereby suggestingthe predominance of further maturated T_hP cells. The D45RC^–NTA260⁺(S III) subset mainly produced IL-4, IL-10, IFN- and less IL-2,and contained memory cells that helped the secondary antibodyresponse to a recall antigen, and hence contained T_h2 and probablya mixture of T_h0 and T_h1 cells. The CD45RC^–NTA260^–(S IV) subset was a poor responder to the immobilized anti-CD3mAb. The CD45RC^brightNTA260^dull(S V) subset consisted of a smallnumber of cells that were phenotypically analogous to activatedCD4⁺ T cells. While an age-associated decrease in the proportionof S I and less markedly in S II and in turn increase in S IIIsubsets of CD4⁺ T cells occurred in normal BALB/c mice, autoimmunedisease-prone (NZBxNZW)F₁ mice showed a marked age-associateddecrease in the proportion of not only S I, II but also IIIsubsets. As aged (NZBxNZW)F₁ mice carry CD4⁺ T helper cellsfor IgG anti-DNA antibody production, such age-associated polarizationto the S IV subset appears to be critical in the pathogeneslsof autoimmune disease in these mice.     

Evaluation of a new reflectance pulse oximeter for clinical applications

The design of a noninvasive reflectance pulse oximeter that uses the same principle of transmittance pulse oximeter and analyses the oxygen saturation of arterial blood was described. Four sets of red and infra-red LEDs were used as light sources. The respective reflectance photoelectric outputs were used to make an internal calibration curve of the instrument relative to the arterial oxygen saturation values measured with a Co-Oximeter (OSM-3) in five healthy nonsmoking subjects during steady-state hypoxaemia. The accuracy of the present instrument was studied in six patients with respiratory failure. From 22 samples, a good correlation coefficient (0.98) with a standard deviation of 1.42 was obtained in the range between 73 and 100 per cent between the arterial oxygen saturation measured with the present instrument and that with the Co-Oximeter. The result strongly suggests the usefulness of this oximeter in monitoring patients with hypoxaemia.     

PERINEURIAL CELL TUMOR AND THE SIGNIFICANCE OF THE PERINEURIAL CELLS IN NEUROFIBROMA

The authors attempted to clarify the exact cell components of neurofibroma by immunohistochemical and ultrastructural studies. Materials were randomly selected, 40 cases of neurilemoma and neurofibroma (-tosis) in addition to 2 cases of tumors composed exclusively of perineurial cells and three cases of normal peripheral nerve. The applied markers included antisera of S-100 protein for Schwann cells, blood coagulation factor XIIIa for endoneurial fibroblasts or perineurial cells, and laminin and collagen type IV for the basement membrane. S-100 protein was demonstrated only in normal or neoplastic Schwann cells, but not in perineurial cells. On the other hand, factor XIIIa was often recognized in endoneurial fibroblasts and perineurial cells, but not in Schwann cells. Neurofibroma was basically composed of a mixture of Schwann cells, perineurial cells, and endoneurial fibroblasts, the population of each type of cell differing according to the case and area within a given tumor. Perineurial cell tumor exclusively composed of perineurial cells, though rare, appears to be a definite entity, and its characteristic histological and ultrastructural features were described.     

A case with multiple myeloma in which serum forms gel precipitation upon exposure to air

We present the case of a 69-years-old man who was admitted to hospital with multiple myeloma. IgG-kappa type monoclonal protein was detected in the serum. When we separated the serum obtained from blood sample of the patient and the lid of the collecting tube was opened, the patient's serum became gelled immediately. When the lid of the collecting tube remained closed, the patient's serum did not become gelled even at 4 degrees C. Moreover, the gelled serum of the patient did not resolve at 56 degrees C. Taken together, these results indicated that gel formation of the patient's serum may not be due to cryoglobulin. It was found that the pH of the patient's serum elevated to pH 8.0 quickly after exposed to air. It was also found that the patient's serum, but not the sera of other IgG-kappa multiple myeloma patients, became gelled as soon as PBS of pH 8.0 was added. These results highly suggest that the patient's serum becomes gelled at pH 8.0. However, the isoelectric focusing of isolated precipitation in the patient showed fractions around the pH 8.5-8.7 zone, which was different from the pH at which the precipitation began to form. We think that this may be the first report of a multiple myeloma patient whose serum becomes gelled after exposed to air.     

Pseudomonas aeruginosa

We investigated the causes of nosocomial infection of P. aeruginosa in a recent outbreak of P. aeruginosa in our hospital. Multi-drug-resistant-P. aeruginosa(MDRPS) that did not produce class B beta-lactamase was isolated from 20(40.0%) patients, occurring in 50 patients hospitalized in the Internal Medicine Ward E in our hospital in 1999 was investigated. All of the patients had brain-vesicular damage as the underlying disease, and 12 patients had been fed by nasal feeding or through a gastric stoma. MDRPS was isolated from sputum(7), urine samples(8), wound discharge(4) and 1 catheter. The bacteria were resistant to piperacillin, ceftazidime, sulbactam/cefoperazone, minocycline and ofloxacin, and in 40% the MIC of the imipenem was more than 8 micrograms/ml. We did not detect MDRPS in any equipment parts or waste water, including the sink in Ward E, but it was detected in the nutrient fluid for nasal feeding and in the line of one patient. The DNA homology of MDRPS isolated from the patient and the nutritive liquid was the same as that of some strains isolated in Ward E, as shown by random amplified DNA polymorphism PCR. In conclusion, we speculated that some nosocomial infections due to MDRPS resistant to imipenem were caused by contaminated nasal feeding.