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Biomedical subjects

S Kawanami

Publications and source records attributed to S Kawanami.

At least 37 records · Page 2Linked to original sources
PubMed1987

Purification of acetylcholine receptor-like protein from fetal calf thymus.

A cobrotoxin binding protein from the fetal calf thymus was isolated by affinity chromatography after solubilization with sodium cholate. The specific activity as a nicotinic acetylcholine receptor (AChR) was determined by assessing the binding to [3H]-alpha-bungarotoxin (BuTx), using the high-pressure liquid chromatography. An AChR-like protein was detected in the amount of 1.39-2.14 nmol per g protein. The first peak of 420k-protein from gel filtration of the eluate of affinity chromatography on a Sephacryl column showed one major polypeptide band with an Mr of 40k, by polyacrylamide gel electrophoresis in sodium dodecylsulfate, two major protein bands with pI 5.4-5.6 and 9.2 by isoelectric focusing, and reacted with sera from patients with myasthenia gravis.

Animals↗
PubMed1984

Enzyme-linked immunosorbent assay for antibody against the nicotinic acetylcholine receptor in human myasthenia gravis.

Antibody against acetylcholine receptor (AChR) of human skeletal muscle was measured using enzyme-linked immunosorbent assay and found in 23 (74%) of 31 Japanese patients with generalized myasthenia gravis. In 15 patients with generalized myasthenia gravis who had not undergone thymectomy and who were not receiving adrenocorticosteroids, the antibody was found in 13 (87%). Antibody was also found in 13 (54%) of 24 patients with myasthenia gravis against AChR fractions obtained from fetal calf thymus. Based on the subunit structures of the AChR protein, the double precipitation assay using iodine 125-alpha-bungarotoxin is also capable of detecting antibody against the toxin binding site, by cross reactivity. This is among the first reports of experiments in which enzyme-linked immunosorbent assay was used to measure the antibodies in human myasthenia gravis and provides evidence of anti-AChR antibody against antigens from fetal calf thymus.

Autoantibodies↗
PubMed1984

Isolation of acetylcholine receptor-like protein from fetal calf thymus.

Cobrotoxin-binding protein from fetal calf thymus was isolated by affinity chromatography after solubilization with Triton X-100 or sodium cholate. Its specificity as a nicotinic acetylcholine receptor (AChR) was determined by assessing the binding to radiolabeled alpha-bungarotoxin (BuTx) and to serum containing antibody against AChR obtained from a patient with myasthenia gravis (MG). AChR-like protein was detected in the amount of 0.41 -2.04 X 10(-9) mol alpha-BuTx binding sites per g protein. Polyacrylamide gel electrophoresis in sodium dedecylsulfate (SDS) revealed polypeptide bands with molecular weights of 40,000, 46,000, 55,000, 70,000, 35,000, and 26,000 daltons. As this protein may play an important role in immunopathological changes in MG, related studies are underway.

Animals↗
PubMed1983

Segmental demyelination and remyelination in lumbar spinal roots of patients dying with diabetes mellitus.

Morphometric evaluations of histopathological changes in postmortem materials from three patients with diabetes mellitus with neuropathy, nephropathy, and retinopathy were made on the sural nerve, lumbar spinal roots, lumbar dorsal root ganglion (2 cases), and fasciculus gracilis. In all three patients there was a marked decrease in densities of both the large and the small myelinated fibers in the sural nerves. In the lumbar spinal roots, segmental demyelination and remyelination with or without decrease in the number of myelinated fibers per root was the main finding in both dorsal and ventral roots, being more common in the dorsal roots. At the third cervical segment of the fasciculus gracilis, the myelinated fiber density was slightly decreased in one patient and moderately decreased in the other two. The number of cell bodies of the fifth dorsal root ganglion was within normal limits in the two patients where this was examined, although the median diameters approximated the lower limit found in controls. The potential presence of segmental demyelination and remyelination in dorsal and ventral spinal roots should be considered especially when assessing electromyographic changes and nerve conduction in diabetic patients.

Adult↗
PubMed1979

Role of thymectomy in the surgical treatment of myasthenia gravis.

Of the 26 patients with myasthenia gravis undergone thymectomy, 11 cases had either benign or malignant thymoma as judged not only by hitological examination but also by their clinical and operative findings. Age of initial onset ranged from 13 to 64 years old. Fifteen out of 26 (58 per cent) benefited from thymectomy. Duration of the symptom from the onset to the operation and the presence or absence of the thymoma are not related to their outcome. Benign or malignant nature of thymoma should not be determined by histological examination alone but by combined evaluation of clinical and operative findings. Serial studies of serum immunoglobulin levels before and after thymectomy suggested that this disorder could be associated with humoral antibody (IgG). HLA typing of the patients with myasthenia gravis did not indicate the presence of any specific antigens.

Adolescent↗
PubMed1979

Lymphocyte function in myasthenia gravis.

Mitogen-induced blastoid transformation of peripheral blood lymphocytes from patients with myasthenia gravis was studied using a microplate culture technique and evaluated with 3H-thymidine incorporation. It was found that both phytohaemagglutinin and pokeweed mitogen responses decreased significantly in patients with myasthenia gravis. In myasthenic crisis, indices of stimulation by phytohaemagglutination became very low. The autologous plasma neither inhibited nor facilitated mitogenic responses of lymphocytes. The decreased mitogen responsiveness of lymphocytes suggests that part of the T lymphocyte function is subnormal in myasthenia.

Adult↗
PubMed1979

T and B lymphocytes in myasthenia gravis.

Peripheral blood lymphocytes from seventeen non-thymectomized and nine thymectomized patients with myasthenia gravis (MG) and thirteen healthy controls were examined for the presence of surface markers characteristic of T and B lymphocytes by rosette formation with sheep red blood cells (SRBC). T cells were identified by their capacity to spontaneously form rosettes with SRBCs. The percentage of B lymphocytes was determined by the erythrocyte antibody complement (EAC) rosette-forming test. The EAC complex was prepared with either whole rabbit anti-SRBC serum or with the IgM fraction of rabbit anti-SRBC serum. The two kind of erythrocyte complement rosette-forming cells (EAC-RFC) are designated erythrocyte-haemolysin-complement RFC (EA(H)C-RFC), and erythrocyte-IgM-complement RFC (EA(M)C-RFC). The percentage of total lymphocytes and T cells was not altered in MG patients. The percentage of 'active' T cells, which have been considered to be more actively involved in cellular immunity, was also similar in MG patients and controls. A significant increase in EA(H)C-RFC occurred in both thymectomized and non-thymectomized MG patients, while in B cells detected by EA(M)C-RFC no alterations were found. The increase in EA(H)C-RFC in lymphocytes from MG patients may be due to an increase in the 19S antibody-forming B lymphocytes or to an increase in T cells which have Fc receptors on their surface.

Adolescent↗
PubMed1978

HLA and Japanese MS.

Determination of HLA-A, -B and -C types in 43 Japanese patients with multiple sclerosis (MS) and of DR type in 25 MS patients was carried out using antisera from the 7th International Histocompatibility Workshop. The results were compared with 46 controls typed simultaneously. Twenty-three patients were also tested for HLA-Dw2. The conclusions were: 1) There were no significantly higher occurrences of HLA-A3, B7, Dw2 or DRw2 in Japanese MS. 2) Japanese MS might nevertheless be associated with the human major histocompatibility complex, because HLA-B40 was significantly less frequent in MS and two anti HLA-DRw sera, 7w008 and 034, reacted positively more often against lymphocytes from MS patients.

Epitopes↗
PubMed1976

Leucocyte migration inhibition in myasthenia gravis. The effect of thymectomy.

Cellular hypersensitivity in myasthenia gravis (MG) to the thymus, muscles and peripheral nerves was examined by the method of the leucocyte migration inhibition test. The group of MG patients without thymoma had inhibition of leucocyte migration by thymus antigens. After thymectomy, they had a normal value of leucocyte migration. However, in the group of MG patients with thymoma, the inhibition of leucocyte migration by thymus antigens was observed after thymectomy. No significant inhibition of leucocyte migration was observed using muscle and peripheral nerve antigens. Cellular immunity in myasthenia gravis and the pathogenesis of the disease was discussed.

Adult↗