Kiyoe Ohta

Production of prostacyclin-like substance in stroke-prone and stroke-resistant spontaneously hypertensive rats

Activities of aortae to produce prostaglandin (PG) I2-like substance in stroke-prone spontaneously hypertensive rats (SHRSP), stroke-resistant SHR (SHRSR) and normotensive control rats from the Wistar-Kyoto (WK) colony were compared. PGI2-like substance was produced by the incubation of the aortic ring in pH 9.0 borate-buffered saline and the amount produced was estimated by comparison of its anti-aggregatory activity with that produced by known amounts of the sodium salt of synthetic PGI2. Before the development of stroke, amounts of this substance generated in SHRSP and SHRSR were significantly higher than those in WK rats (p less than 0.01 and p less than 0.02, respectively). Remarkably reduced capacity to generate PGI2-like substance was observed in some SHRSP after the development of stroke.

HTLV‐I Myelitis: Isolation of Virus, Genomic Analysis, and Infection in Neural Cell Cultures

Human T-lymphotropic virus type I (HTLV-I) is an exogenous retrovirus originally associated with an endemic malignancy termed adult T-cell leukemia ( ATL). More recently recognized HTLV-I myelitis (HTLV-I M).2 is characterized by perivascular infiltration of lymphocytes and foamy cells and predominant involvement of white matter usually without association with ATL. Western blotting analysis of sera from patients with ATL and of sera and cerebrospinal fluid (CSF) of patients with HTLVI M revealed similar antibody binding patterns to HTLV-I antigens. To elucidate the pathogenetic mechanism of HTLV-I M, we established virusproducing T-cell lines from the peripheral blood and CSF mononuclear cells of 25 patients with HTLV-I M. All cell lines were positively stained with HTLV-I M sera, ATL sera, and monoclonal antibodies to HTLV-I gag proteins p15, p19, and p24, and revealed type C viral particles by electron microscopic studies. Cytofluorographic analysis showed most of the line cells have T3, T4, 2H4 , T8 ., TI 1 +, Tac + (IL2R ), and Ia + helper inducer surface markers. By restriction map analysis, we found two major subgroups of HTLV-I: MT-2 type and ATK-1 type.4 They were almost equally distributed among the patients with HTLV-I M. We also found two types of the provirus in DNA derived from fresh peripheral blood lymphocytes of patients with ATL. It was concluded that two subgroups of HTLV-I exist in Japan, and both have the ability to cause both ATL and HTLV-I M (FIGS. 1 and 2). Cultured human endothelial cells and glial line cells (GFAP-positive and GFAPnegative) were infected by HTLV-I and showed syncithium formation, degenerative changes, and cell lysis when co-cultured with HTLV-I-producing T-cell lines derived either from HTLV-I M or ATL. GFAP-positive astrocytes in dissociated newborn rat brain cell cultures were also infected with HTLV-I derived from either of the two diseases. Galactocerebroside-positive oligodendrocytes rapidly disappeared in these cultures within a few days after application of irradiated virus-producing T cells, although HTLV-I-antigen-positive oligodendrocytes were only rarely recognized by a double-staining indirect immunofluorescence technique. Application of the conditioned medium of HTLV-I-infected T-cell line cultures did not suppress oligodendrocyte

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.

CHEMICAL ANALYSIS OF VASCULAR COLLAGEN IN STROKE-PRONE SPONTANEOUSLY HYPERTENSIVE RATS

Chemical characteristics of vascular collagen were studied in stroke-prone spontaneously hypertensive rats (SHRSP) which developed cerebrovascular lesions spontaneously in over 90% of the population. Aminoacid analysis of arterial collagen among SHRSP showed no remarkable difference from stroke-resistant SHR (SHRSR) and normotensive Wistar-Kyoto rats (WK). The uronic acid content of the aorta, which elevated with aging, was increased in SHRSR and especially in SHRSP. The hexose content of collagen was also increased in SHRSP characteristically with a concomitant increase in the ratio of the disaccharide unit (glucosyl-galactosyl-hydroxylysine) to the monosaccharide (galactosyl-hydroxylysine). The relative increase in beta and gamma components was also noted in SHRSP. These structural changes of vascular collagen especially noted in SHRSP may be related to the fragility of arterial wall or to the stroke-proneness.

Sera from Patients with Multiple Sclerosis React with Human T‐Cell Lymphotropic Virus‐I GAG Proteins: Western Blotting and Solid‐Phase Radioimmunoassay Analyses

We examined the presence of IgG and IgM antibodies reactive with HTLV-I viral antigens in sera from Japanese patients with multiple sclerosis (MS) in the Kyoto district, a nonendemic area for adult T-cell leukemia (ATL), using Western blotting analysis and a sensitive radioimmunoassay (RIA). Our data revealed that 11 (24%) of 46 patients with clinically definite MS had IgG and/or IgM antibodies reactive with antigens corresponding to the group-specific antigen (gag) proteins (p15, p19, and p24) by Western blotting analysis using disrupted virions from the virus-producing TCL Kan cells as antigens (FIG. 1). Those seropositive MS patients consisted of four with IgG antibodies reactive mainly to the gag p24 and/or p15 protein, four with IgM antibodies reactive mainly to the gag p24 and/or p19 protein, and three with both IgG and IgM antibodies (TABLE 1). These immunostaining patterns of MS sera were clearly distinguishable from those of patients with ATL who had antibodies to the envelop (env) proteins and their precursors in addition to the gag proteins. The antibody in MS sera was generally of low titer and reactive at a high serum concentration ( 1 / 10 dilution). None of the sera from 9 patients with other neurologic diseases (OND) and from I1 healthy controls had the viral antibodies. We also developed a simple and highlysensitive RIA for the detection of antibody to HTLV-I or p24 and surveyed 55 patients with clinically definite MS, 27 patients with OND, and 36 normal controls. The average age of patients with MS was 42.0 (range 14 to 69 years). Of all MS sera tested by RIA, 45% (25/55) had IgG and/ or IgM antibodies against HTLV-I-disrupted virions, and 44% (24/ 55) had IgG and/or IgM antibodies against HTLV-I p24. This result is similar to that of Koprowski et al. who used a sensitive EIA method. The levels of antibodies and the frequency were low in comparison with those in ATL, HTLV-I myelitis, or HTLV-I carriers. There was no apparent relation between the occurrence of the antibodies in MS and

ANTI‐ACETYLCHOLINE RECEPTOR ANTIBODIES IN MYASTHENIC SERUM AND THYMUS: THEIR CORRESPONDENCE AND DISCREPANCY WITH CLINICAL CONDITIONS

The author reported the relationship between the titers of antiacetylcholine receptor ( AChR) antibodies, clinical state and findings of single fiber electromyography in a series of myasthenic patients using two theoretically different assay systems in order to elucidate their correspondence and discrepancy with clinical conditions. One hundred and forty-one myasthenic patients out of 210, namely 65%, showed positive result by immunoprecipitation method, assuming that the antibody recognizes antigenic determinants other than toxin binding sites in AChR protein, thus constitutes of “noninhibitory” antibody. We adopted a new classification of patients into familial and non-familial types, the latter being divided into thymoma and nonthymoma groups. In the nonthymoma group the patients were classified into four types; ocular, generalized mild, moderate and severe types. Serial changes of the titers of anti-AChR antibody assayed by immunoprecipitation method showed close and parallel fluctuation associated with clinical changes; namely, yearly decrease after complete thymectomy, monthly decrease during steroid therapy, and abrupt changes during myasthenic crisis. We obtained positive results in 53 out of 70 (73%) myasthenics using the concanavalin A Sepharose method, assuming that the antibody recognizes the neurotoxin binding site and/or sugar chain on AChR. There was more loose correlation of the inhibitory activity of the “inhibitory” antibody with the clinical state, comparing with the case in “noninhibitory” antibody. Comparative and simultaneous assays in 81 myasthenic patients using the immunoprecipitation and concanavalin A method were carried out. In 20 cases of the ocular type, the titers of both antibodies were low comparing with other myasthenic groups. In 16 cases of thymoma, there was a significant correlation at the 5 % level between both antibody titers. On the contrary, in 45 cases of generalized nonthymoma, they were diverse and scattered without significant correlation to each other. These data suggested that there may be different types of immune responses producing heterogeneous anti-AChR antibodies depending upon the types of myasthenia gravis and/or clinical conditions. This could elucidate part of the occasional discrepancies between the antibody titers and clinical symptoms.