Experimental arthritis induced by continuous infusion of IL-8 into rabbit knee joints.

To determine the roles of IL-8 in inflammatory synovitis, examination was made of the results of continuously injecting human recombinant IL-8 into the knee joints of New Zealand while rabbits. Recombinant human IL-8 was infused continuously into the joint cavity at 75 ng/h for 14 days by a polypropylene catheter connected to a mini-osmotic pump implanted in each rabbit. Infiltration of inflammatory cells into joint cavity and histopathological changes in synovial tissue were examined at 7 and 14 days following the start of infusion. The continuous infusion of IL-8 for 14 days led to severe arthritis characterized by apparent erythema and joint pain, the accumulation of leucocytes, infiltration of mononuclear cells in synovial tissue, and marked hypervascularization in the synovial lining layer. IL-8 may be a factor which can contribute to the inflammatory process of chronic arthritis by mediating leucocyte recruitment and hypervascularization in inflamed joints.     

HeLa cell invasiveness and O antigen of Shigella flexneri as separate and prerequisite attributes of virulence to evoke keratoconjunctivitis in guinea pigs.

Many rough mutants selected from isogenic smooth virulent and avirulent strains of Shigella flexneri were examined for virulence, using tissue culture infection and Sereny tests. Many of the rough mutants isolated from a virulent smooth strain were capable of penetrating tissue culture cells but incapable of producing a positive Sereny test. In contrast, we could not obtain from smooth avirulent strains any rough mutants capable of penetrating HeLa cells. Chemical analysis of lipopolysaccharide of some representative rough strains showed several patterns of sugar composition with a range of from Ra to Re chemotypes. There was no correlation between HeLa cell invasiveness and chemotypes of lipopolysaccharides, thus indicating little significance of oligosaccharides of the rough core as well as O antigens in the ability of S. flexneri to penetrate HeLa cells. When these invasive rough strains were given O antigen genes from a smooth avirulent Shigella Hfr strain, most of the transconjugants that expressed O antigens regained the ability to evoke keratoconjunctivitis in guinea pigs. We also examined the chromosomal loci of HeLa cell invasion by transferring carbohydrate fermentation genes of Escherichia coli K-12 Hfr and found two chromosomal loci, the rha and lac-gal regions, which control the ability to penetrate HeLa cells. These results suggested that O antigens and ability to penetrate tissue culture cells are independent and prerequisite attributes of virulence in Shigella flexneri to evoke keratoconjunctivitis in guinea pigs.     

Human monoclonal anti-nuclear antibodies produced by human-mouse heterohybridomas

To obtain human monoclonal anticentromere antibodies, mouse myelomas were fused with unfractionated mononuclear cells from the peripheral blood of a patient diagnosed as having the CREST variant of scleroderma: with only anticentromere antibodies. After a single fusion an heterohybridoma secreting a human antibody specific for nuclear antigens, as detected by indirect immunofluorescence staining, was isolated. The monoclonal antibody secreted by the clone was of the human IgM class. Indirect immunofluorescence staining of the antibody on HEp-2 cells showed multiple nuclear dots or a discrete speckled pattern resembling that of an anticentromere antibody. Immunoblot analysis showed antibody binding to a 33 kD antigen derived from the nuclear protein fraction. Enzyme-immunoassay results clearly showed that the antibody reacted with the chromosomal protein fraction and not calf thymus DNA.     

Electrophysiological comparison between patients with Binswanger's encephalopathy and Alzheimer's disease

Short-latency somatosensory (SSEPs), brainstem auditory evoked potentials (BAEPs) and event-related potentials (ERPs) were studied in 7 patients with Binswanger's encephalopathy, 12 patients with Alzheimer's disease and 17 normal subjects. Patients with Binswanger's encephalopathy showed significantly prolonged central conduction time (CCT) and P300 latency, and prolonged tendency of I-V IPL compared to those of normal subjects. In particular, CCT showed significant prolongation compared to that of patients with Alzheimer's disease. In patients with Alzheimer's disease, I-V IPL and P300 latency were significantly prolonged compared to those of normals although there was no significant difference in CCT between Alzheimer's disease and normal subjects. These results indicate some difference between Binswanger's encephalopathy and Alzheimer's disease from the electrophysiological aspects although both of these entities are characterized by progressive mental deterioration.     

Relationship between immediate hypersensitive reactions by buckwheat ingestion and specific IgE for rice in subject with positive IgE-RAST for buckwheat]

IgE-mediated mechanisms are important in immediate hypersensitive reactions (IHR) to buckwheat. However, a part of subjects with high IgE for buckwheat show no IHR to buckwheat ingestion. Inspite of cross-allergenicity between buckwheat and rice, rice ingestion rarely induces IHR even in subjects with high IgE for rice unlike buckwheat-induced IHR. We speculated that there were some relationships between the presence of IHR to buckwheat and recognition of cross-allergenic determinants on buckwheat components with rice components. We examined IgE-RAST for rice in 58 subjects with positive IgE-RAST for buckwheat. IgE-RAST for Dermatophagoides pteronyssinus (Dp), egg white and cow's milk as unrelated antigens with rice were also assessed for a comparison. Subjects (n = 33) without IHR to buckwheat showed higher IgE-RAST values for rice than those (n = 25) with IHR, whereas there were no differences in IgE-RAST values for Dp, egg white and cow's milk between two groups with and without IHR. IgE-RAST values for buckwheat showed significant close correlations to those for rice in subjects without IHR to buckwheat but not in those with IHR. There were no significant correlations between IgE-RAST values for buckwheat and for Dp, egg white or cow's milk in both groups with and without IHR. These results suggested that the IgE from subjects without IHR to buckwheat recognized cross-allergenic determinants with rice on the buckwheat components.     

Restriction site polymorphism at the LPA (Lp(a) apoliprotein; apoliprotein(a)) locus

A restriction site polymorphism in the Lp(a) apolipoprotein gene (the LPA gene) is reported. The basis for the polymorphism is presence or absence of an MspI restriction site that appears to be 3' to the last kringle IV structure of the gene. The "1" gene (presence of the restriction site) has a frequency of 0.316 and the "2" gene (absence of the restriction site) has a frequency of 0.684. Both members of each of 67 monozygotic (MZ) twin pairs had the same genotype and there was Mendelian segregation of the DNA variants in 40 families with a total of 75 children. There was a lower proportion of people with genotype 1-1 in the top quartile than in the 3 bottom quartiles of the population distribution of Lp(a) lipoprotein levels but the difference did not reach statistical significance.     

Ras homolog gene family H (RhoH) deficiency induces psoriasis-like chronic dermatitis by promoting TH17 cell polarization

1. Download : Download high-res image (104KB)
2. Download : Download full-size image

     

Modulation of the control of muscle sympathetic nerve activity during severe orthostatic stress

We tested the hypothesis that arterial baroreflex (ABR)-mediated beat-to-beat control over muscle sympathetic nerve activity (MSNA) is progressively modulated as orthostatic stress increases in humans, but that this control becomes impaired just before the onset of orthostatic syncope. In 17 healthy subjects, the ABR control over MSNA (burst incidence, burst strength and total MSNA) was evaluated by analysing the relationship between beat-to-beat spontaneous variations in diastolic blood pressure (DAP) and MSNA during supine rest (control) and during progressive, stepwise increases in lower body negative pressure (LBNP) that were incremented by −10 mmHg every 5 min until presyncope (nine subjects) or −60 mmHg was reached. (1) The linear relationships between DAP and burst strength and between DAP and total MSNA were shifted progressively upward as LBNP increased until the level at which syncope occurred. The relationship between DAP and burst incidence, however, gradually shifted upward from control only to LBNP =−30 mmHg; there was no further upward shift at higher LBNPs. (2) Although the slope of the relationship between DAP and burst strength and between DAP and total MSNA remained constant at all LBNPs tested, except at the level where syncope occurred, the slope of the relationship between DAP and burst incidence was reduced at LBNPs of −40 mmHg and higher ( versus control). (3) In syncopal subjects, the slopes of the relationships between DAP and burst incidence, burst strength, and total MSNA were all substantially reduced during the 1–2 min period prior to the onset of syncope. Taken together, these results suggest baroreflex control over MSNA is progressively modulated as orthostatic stress increases, so that its sensitivity is substantially reduced during the period immediately preceding the severe hypotension associated with orthostatic syncope.     

Education of medical technologists in North America

The increasing complexity of diseases and advancing medical technologies have recently raised the number of test items and their use. This has caused each department to ask for clinical support by medical technologists, including consultation services on clinical laboratory tests in Japan. Under these circumstances, we think it is necessary to consider a Japanese education system for medical technologists to foster people with advanced ability capable in providing adequate clinical support. It is important that we study medical technologist systems and education systems superior to than ours. Therefore, to investigate the state of the Japanese education system for medical technologists, we conducted a comparison between the medical technologist systems and education systems in foreign countries and those of Japan. The social background in which medical technologists are positioned, their scope of work, and the education systems overseas are different from Japan on many points and we were given many suggestions for what a system in Japan should be like.