[Therapeutic plasma exchange for neuroimmunological disorders].
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Biomedical subjects
Publications and source records attributed to N Shibuya.
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The effects of ketamine on Ca(2+)-activated K+ channel currents were studied in dispersed single smooth muscle cells from rabbit portal vein using inside-out patch clamp technique. In a near physiological K+ and Ca2+ gradient, three populations of outward rectangular single currents were recorded in isolated cell membrane of rabbit portal vein at +60 mV membrane potential. These currents were judged as Ca(2+)-activated K+ channel currents since application of EGTA or Apamin in the internal solution inhibited these currents. Application of 10(-5)M or 10(-4)M ketamine inhibited the number of occurrences of channel opening and decreased open times, but did not reduce the amplitudes. When the 10(-3)M ketamine was applied, the Ca(2+)-activated K+ channel currents were abolished. We suggest that the depression of Ca(2+)-activated K+ channel currents may explain the continuous contraction observed in rabbit portal vein at a clinical concentration of ketamine from a point of electrophysiological K+ current study.
A stable subunit of Sambucus sieboldiana bark lectin (MSSA) was prepared by selective reduction of disulfide bridges between the subunits and alkylation with 4-vinylpyridine. Amino acid analysis of MSSA revealed that 1.4 cysteine residues per subunit were selectively modified. MSSA failed to agglutinate rabbit erythrocytes and precipitate fetuin. However, MSSA retained the ability to bind to fetuin, as detected by ELISA. Neu5Ac alpha 2-6lactose inhibited the binding to fetuin of both SSA and MSSA. Flow cytometric analysis showed that human histocytic lymphoma U937 cells were clearly stained with FITC-labeled MSSA (FITC-MSSA) without any detectable agglutination and that this staining was almost completely inhibited by the addition of Neu5Ac alpha 2-6lactose (2 mM). Treatment of U937 cells with native FITC-SSA at the sub-agglutinating concentration (0.3 microgram/ml) showed much poorer fluorescence intensity than that of MSSA, suggesting that MSSA is an invaluable tool for the detection of cell surface glycoconjugates containing NeuAc alpha 2-6Gal/GalNAc sequences by flow cytometry.
The interaction of Japanese elderberry bark lectin (Sambucus sieboldiana agglutinin, SSA) with carbohydrate was investigated by 1H-NMR. When a low affinity ligand, methyl beta-D-galactoside (beta MeGal), was mixed with SSA, each proton signal of beta MeGal was broadened. The signal of H-4 was markedly broad, while those of H-1, OCH3, and H-2 of beta MeGal were rather sharp. The specific broadening of Gal H-4 was more evident when SSA was mixed with methyl-beta-D-lactoside (beta MeLac). Position-dependent signal broadening suggests that beta MeGal binds to SSA such that H-4 is closely involved in the contact region, but H-1, OCH3, and H-2 are far from this region. In the case of a high affinity ligand, Neu5Ac(alpha 2-6)Gal(beta 1-4)Glc(= N6L), ligand signals of the SSA-N6L mixture did not change at all. But when a small amount of N6L was added to the SSA-beta MeGal mixture, the broad signals of bound beta MeGal became dramatically sharp. This indicates that the added N6L molecules liberated the bound beta MeGal from SSA. On the other hand, the sialyllactose with the alpha(2-3)-linkage(= N3L) could not substitute for bound beta MeGal because of its lower affinity. This demonstrates that the competitive binding experiment between two ligands is a useful technique to detect the interaction of lectins with high affinity ligands which could not be observed directly by NMR signal broadening and/or chemical shift change.
The effects of ketamine on membrane potentials and long-lasting type (L-type) voltage-dependent Ca2+ currents were investigated in dispersed single smooth muscle cells from rabbit portal veins. The amplitude and duration of the action potentials evoked by intracellular stimulation were inhibited by ketamine and were completely blocked by 10(-3) mol/l ketamine. Ketamine, however, did not alter the resting membrane potential. Whole cell voltage clamp experiments revealed that ketamine at concentrations higher than 10(-4) mol/l reduced the peak L-type voltage-dependent Ca2+ currents. These effects of ketamine were concentration-dependent and reversible at concentrations from 10(-4) to 10(-3) mol/l. Moreover, the activation threshold of L-type Ca2+ current (approximately -30 mV) was slightly shifted to the positive potential side by ketamine. This effect can explain that the action potential was abolished by 10(-3) mol/l ketamine. It is concluded that relaxation of the vascular smooth muscle by ketamine may have to be attributed to the inhibition of L-type voltage-dependent Ca2+ current.
Serotype-specific polysaccharide antigens from Actinobacillus actinomycetemcomitans ATCC 29523 (serotype a) and NCTC 9710 (serotype c) were extracted from whole cells by autoclaving and purified by ion-exchange chromatography and gel filtration. Analysis of component sugars by gas-liquid chromatography-mass spectrometry, high performance liquid chromatography, and NMR together with optical rotation data showed that the serotype a antigen was composed solely of 6-deoxy-D-talose, whereas the serotype c antigen consisted of 6-deoxy-L-talose. Structural analysis indicated that both of these antigens were composed of closely related repeating units, -3)-6-deoxy-alpha-D-Talp-(1-2)-6-deoxy-alpha-D-Talp-(1-(sero type a) and -3)-6-deoxy-alpha-L-Talp-(1-2)-6-deoxy-alpha-L-Talp-(1-(sero type c). 1H and 13C NMR analysis showed that both of these serotype antigens contained one acetyl group/2 sugar residues. These acetyl groups localized at the O-2 position of 3-linked 6-deoxy-D-talose (serotype a) or O-4 position of 3-linked 6-deoxy-L-talose residues (serotype c), respectively. These results coupled with our previous findings on the serotype b antigen (Amano, K., Nishihara, T., Shibuya, N., Noguchi, T., and Koga, T. (1989) Infect. Immun. 57, 2942-2946) showed that the serotype antigens from A. actinomycetemcomitans are a group of novel polysaccharides with structural features closely related biosynthetically.
The sialic acid-specific leukoagglutinating lectin from the seeds of Maackia amurensis (MAL) has been studied by the techniques of quantitative precipitin formation, hapten inhibition of precipitation, hapten inhibition using an enzyme-linked immunosorbent assay, and lectin affinity chromatography. The ability of the immobilized lectin to fractionate oligosaccharides based on their content of sialic acid has also been investigated. Our results indicate that MAL reacts with greatest affinity with the trisaccharide sequence Neu5Ac/Gc alpha 2,3Gal beta 1,4GlcNAc/Glc. The lectin requires three intact sugar units for binding and does not interact when the beta 1,4-linkage is replaced by a beta 1,3-linkage nor when the "reducing sugar" of the trisaccharide is reduced. Results from enzyme-linked immunosorbent assays show that an N-acetyllactosamine repeating sequence is not required; however, the N-acetyllactosamine repeating sequence does appear to enhance the binding of MAL to a series of glycolipids. In addition, the sialic acid may be substituted with either N-acetyl or N-glycolyl groups without reduction in binding. The C-8 and C-9 hydroxyl groups of sialic acid do not play a role in binding as shown by the strong reaction of periodate-treated glycoproteins. Comparison of the specificity of the three sialic acid-binding lectins indicates that Limax flavus agglutinin binds to Neu5Ac in any linkage and in any position in a glycoconjugate, Sambucus nigra lectin requires a disaccharide of the structure Neu5Ac alpha 2,6Gal/GalNAc, and MAL has a binding site complimentary to the trisaccharide Neu5Ac alpha 2,3Gal beta 1,4GlcNAc/Glc, to which sialic acid contributes less to the total binding affinity than for either S. nigra lectin or L. flavus agglutinin.
Polymerase chain reaction (PCR)-based diagnosis was carried out in 62 patients (57 probands) with Duchenne or Becker muscular dystrophy (DMD or BMD) and 226 members in 57 families. The PCR studies were also performed for carrier detection in 57 mothers and 58 sisters, and prenatal diagnosis of 4 fetuses at risk of DMD. The PCR with 7 sets of primers, which amplify 7 different exon-sequences of the dystrophin gene, detected gene deletion of at least one exon in 49% of the probands. The PCR with the other 4 primer sets, which amplify 3 intragenic loci, and subsequent endonuclease digestion detected in 84% of the mothers a heterozygous pattern in at least one such locus/segment. Using the same primer sets, carrier detection was successful in 5 sisters of familial DMD cases, while recombination between the ERT87 and the 3' end intragenic loci was observed in 11% of family members studied. Prenatal diagnosis was made in all the 4 fetuses; two males were affected, one male fetus non-affected, and the remaining one female fetus a carrier. Thus, the PCR study and the primers used in the present study are useful and convincing for rapid diagnosis of DMD and/or BMD.
There were 55 patients (soft disc, 21 and spondylosis, 34) who underwent anterior cervical discectomy without fusion (ACD) using an operating microscope. Discectomy of a single level was performed on 48 cases and two levels on 7. There were 37 patients with radiculopathy, and 18 patients with myelopathy or myeloradiculopathy who were followed clinically for 2-13 years postoperatively. Overall 81% of patients were improved in soft disc herniation, and no significant differences were noted between the group of radiculopathy and myelopathy. In spondylosis all but one patient reported initial relief of their preoperative symptoms; however, overall improvement was noted in only 16 patients (47%). The causes of symptomatic deterioration after ACD for spondylosis were later symptomatic recurrence in 5 patients, severe neck pain in 4, and development of new symptoms due to adjacent spur formation in 2. The authors eventually added interbody fusion in 4 cases. Cervical spine roentgenograms almost always showed a loss of height of the interspace and an anterior angulation immediately after ACD, but the alignment of the spine tended to improve with time, so that, at last follow-up, 82% had a good alignment. A spontaneous osseous fusion occurred in 74% of cases. An adjacent spur formation was observed in 3 patients with spondylosis. The most troublesome complication was neck and/or scapular pain. This pain usually subsided spontaneously, but this continued for more than 4 years postoperatively in 4 patients with spondylosis. Using an operating microscope ACD is a safe and effective procedure for patients with soft disc herniation, but the authors still prefer anterior cervical discectomy with interbody fusion for the patients with advanced spondylosis.
Serotype-specific polysaccharide antigens (SPAs) were extracted from whole cells of Actinobacillus actinomycetemcomitans ATCC 29523 (serotype a), Y4 (serotype b), and NCTC 9710 (serotype c) by autoclaving and purified by chromatography on DEAE-Sephadex A-25 and Sephacryl S-300 columns. Y4 SPA induced interleukin-1 (IL-1) release by P388D1 murine macrophages. Polymyxin B had virtually no effect on the release of IL-1. Rabbit anti-murine IL-1 serum strongly suppressed the proliferation of C3H/HeJ mouse thymocytes induced with the culture supernatants of Y4 SPA-stimulated P388D1 cells and a submitogenic dose of concanavalin A. Gel filtration of the culture supernatants of Y4 SPA-stimulated macrophages on Sephacryl S-200 showed that an IL-1 peak at a point corresponding to approximately 16.5 kDa was eluted. The ability of SPAs from strains ATCC 29523 and NCTC 9710 to induce the release of IL-1 was lower than that of Y4 SPA. The IL-1-releasing ability of serotype a and c antigens was enhanced by deacetylation of both polysaccharides, suggesting that acetyl groups of these antigens might hinder the interaction between the antigens and macrophages.
In the rice-producing district of Japan, environmental pollution by smoke from burnt rice straws has become a matter of concern. The mutagenicity of fly- and bottom-ashes of rice-straw and -husk was assayed by the Ames test, TA100 +/- S9 and TA98 +/- S9, and the relationship of combustion temperature to mutagenicity was investigated. Fly ash showed weak mutagenicity at 300 degrees C, with no remarkable change in mutagenic activity between 300 degrees C and 500 degrees C. Above 500 degrees C the mutagenic activity increased with a rise of temperature. The increasing rate of mutagenicity was much higher in the test system with S9 mix than that without S9. Moreover, the mutagenicity with TA100 was stronger than with TA98. With respect to bottom ash, weak mutagenic activity was observed at 300 degrees C, but at 400 degrees C decreased and at 500 degrees C or above could not be observed. Fly ash derived from burning 1 g of rice straw at 600 degrees C showed about 14 times and 2.5 times higher mutagenicity than main stream smoke condensates from the burning of 1 g of cigarette in TA100 + S9 and TA98 + S9 test systems respectively.
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We studied DNA sequences homologous to HTLV-1 in peripheral blood mononuclear cells (PBMC) of 30 patients with neurological disorders in Kyushu, where HTLV-1 is highly endemic. The regions of HTLV-1 amplified by means of polymerase chain reaction (PCR) included U3, U5, gag, pol, env and pX. Our system specifically detected HTLV-1 sequences only from HTLV-1-positive cells and was sufficiently sensitive to detect one proviral copy per 10(3) PBMC. All PCR-positive cases were seropositive, including 4 cases of tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM) (4/4), and one case each of myasthenia gravis (1/7) and multiple sclerosis (1/8). The PCR-positive rate of patients, excluding 4 TSP/HAM cases, was 8% (2/26), which is similar to the seroprevalence of the adult population in the area. The data suggest that multiple sclerosis is not associated with prototype HTLV-1.
Cardiac involvement is common in patients with Duchenne type muscular dystrophy (DMD). However, published reports of long-term follow-up studies in the same patients are very rare. The purpose of this study was to clarify the natural course of cardiac dysfunction in DMD, and to analyze the relationship between the deterioration of cardiac function and skeletal muscular function. The cardiac function was serially evaluated for 2-12 years in 34 patients with DMD. The systolic time intervals and echocardiography were used for evaluating the cardiac function. The PEP/ET (pre-ejection period/ejection time) of systolic time intervals significantly deteriorated in 9-12 years (p less than 0.001). The maximal systolic and diastolic endocardial velocity (MSEV and MDEV) and the D/S ratio of echocardiography significantly deteriorated in 5 years (p less than 0.001). The D/S ratio is the ratio of the mean systolic velocity and the mean diastolic velocity of the left ventricular posterior wall. In almost half the patients, the deterioration of these parameters was correlated with that of Swinyard's stage. The Swinyard's functional ability stage demonstrates the grade of the skeletal muscular dysfunction. However, there was no correlation between the deterioration of cardiac function and Swinyard's stage in the other half of the patients. Correlation coefficient in the whole group was 0.32 (p = n.s.) between the PEP/ET and Swinyard's stage, and was -0.15 (p = n.s.) between the D/S ratio and Swinyard's stage. Although the mean left ventricular ejection fraction calculated using echocardiography was slightly decreased for 5 years, no significant change was detected in the whole group. One patient had progressive deterioration of left ventricular function despite mild skeletal muscular dysfunction, and died from congestive heart failure. The cardiac dysfunction was predominant. We named it 'cardiac type' DMD. Since deterioration of cardiac function was not always correlated with deterioration of skeletal muscular function (Swinyard's stage), cardiac function must be carefully monitored in patients with DMD.
To evaluate the relationship of 24 hour total heart beats (THB) or ventricular arrhythmias and cardiopulmonary function, 29 patients with Duchenne's muscular dystrophy (DMD) were studied using Holter electrocardiographic and echocardiographic recordings. The THB were 144,428 +/- 12,237 beats per 24 hours in the child group (8 to 15 years, n = 12) and 136,355 +/- 19,991 beats per 24 hours in the adult group (16 to 25 years, n = 17). The THB in the adult group significantly correlated well with % VC (r = -0.74), PaCO2 (r = 0.67), PaO2 (r = -0.59) and the respiration rate (r = 0.71), but not in the child group. In both groups, the echocardiographic parameters of the left ventricular size and function (left ventricular dimension, ejection fraction and D/S ratio) did not significantly correlate with the THB. Premature ventricular contractions (PVCs) were observed in 14 of the 29 patients (48.3%), and high risk PVCs (Lown's grade 3-4b) were observed in 11 of these 14 patients (78.6%). Echocardiographic parameters of the left ventricular function in the high risk PVC group were significantly deteriorated as compared with the low risk PVC group (Lown's grade 0-2) (p less than 0.02-p less than 0.001). We conclude that the THB in the adult group was mainly related to depressed pulmonary function, and the severity of the PVCs in both the adult and child groups was mainly related to the degree of left ventricular dysfunction.
Mutagenicity and co-mutagenicity of MCPA- and MCPB-ethylester were examined in the Ames assay. It was found that they enhance the mutagenic action of 2-aminoanthracene in the Ames assay, although they were not mutagenic.
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A cis-diamminedichloroplatinum (CDDP)-selected cell line (MT-R10) was induced by continuous exposure of an in vitro passaged cell line (MT-P) established from a transplantable rat malignant fibrous histiocytoma (MFH-MT) to CDDP. MT-R10, capable of proliferating in the presence of 1.0 microgram CDDP/ml, was passaged in CDDP-free medium. The doubling time of MT-R10 at passage 10 (MT-R10/10) was almost the same as that of MT-P, being 22.3 and 25.5 h, respectively. The concentration of CDDP required for 50% inhibition of MT-R10/10 proliferation was two-fold higher than that of MT-P. MT-R10 consisted of round, epithelial-type cells arranged in compact sheets. Ultrastructurally, MT-R10 had numerous free ribosomes, some mitochondria, and other poorly developed cytoplasmic organelles suggesting its undifferentiated nature. MT-R10 showed no reaction for acid phosphatase or non-specific esterase. Tumors induced in syngeneic rats by inoculation with MT-R10 consisted of small, round, undifferentiated cells with scanty cytoplasm. They showed organoid and trabecular patterns, and were often arranged in compact sheets. The neoplastic cells showed no reaction for any of the histiocytic lysosomal and antigenic markers tested, but exhibited a strong reaction for alkaline phosphatase. Bone formation was often observed in the tumors. These observations suggest that CDDP-selected, undifferentiated cells may have osteogenic potential and may be one of the progenitor cells of MFH-MT.