Search PubMed⌕ Search

Biomedical subjects

K Shiozawa

Publications and source records attributed to K Shiozawa.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Epidemiological aspects of enteritis due to Campylobacter jejuni].

From September 1986 through July 1987, all fecal specimens obtained from infants and children who visited the pediatric clinic of the Shizuoka General Hospital with complaints of abdominal pain or diarrhea were examined for thermophilic Campylobacters. Bacteriological and epidemiological studies were performed on household contacts. The mothers of the patients were compared with the mothers of age-matched control subjects. Bacteriological examination of animals in 49 primary schools in Shizuoka city was performed. C. jejuni was isolated from 47 (9.4%) of the 499 feces samples, occupying first place in the bacterial etiology of acute bacterial enteritis. Infants and young children below 10 years of age comprised 81% of the total cases. Fourteen (13%) strains of C. jejuni were isolated in 9 families among 105 household contacts of the index patients. Six symptomatic contacts in two households had eaten the same suspected chicken as the respective index patients. In three families, C. jejuni was isolated from the remainder of the chicken. The serotype of these isolates was identical to that of the isolates from the index cases and the other family members. It was also noted that the same chopping boards were used for the preparation of salads after cleansing with water. In two index cases, the antibody of convalescent serum against C. jejuni isolated from the chicken, as estimated by passive hemagglutination method, ranged from 1:320 to 1:1280. These facts strongly supported the assumption that they had been infected by the chicken. The remaining persons were asymptomatic and the possibility was left that the index cases had been secondarily infected by these carrier persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Human epidermal growth factor for the stratification of synovial lining layer and neovascularisation in rheumatoid arthritis.

Immunohistochemical study showed selective localisation of human epidermal growth factor (hEGF) to the synovial lining layer. Although the synovial lining layer of the rheumatoid, osteoarthritic, and traumatic joints was hEGF positive, hEGF staining was especially dense at the rheumatoid synovial lining layer; the staining increasing linearly according to the degree of stratification of the lining layer (r = 1). Human epidermal growth factor was ultrastructurally localised to cytoplasm, especially to rough endoplasmic reticulum, of the synovial lining fibroblast-like (type B) cell. Only the cell surface of macrophage-like (type A) cells was hEGF positive. When different histological variables were compared with each other a positive correlation was found between hEGF staining of the synovial lining layer and the degree of neovascularisation of rheumatoid synovium (r = 0.72). Although some lymphocytes were weakly hEGF positive, neovascularisation did not correlate with the extent of lymphocyte infiltration or of hEGF staining of lymphocytes. Lymphocyte infiltration or hEGF staining of lymphocytes did not correlate with hEGF staining of the synovial lining layer, whereas the lymphocyte infiltration correlated positively with the extent of perivascular accumulation of lymphocytes (r = 0.89). These findings suggest that (a) hEGF is synthesised by and secreted through endoplasmic reticulum and Golgi apparatus from the synovial lining type B cell; (b) hEGF is at least partially responsible for the pathogenesis of stratification of the rheumatoid synovial lining layer, and perhaps of neovascularisation of the rheumatoid synovium, whereas it is not responsible for lymphocyte accumulation to the rheumatoid synovium.

Arthritis, Rheumatoid↗
PubMed1988

Alpha-interferon treatment for adult T cell leukemia: low levels of circulating alpha-interferon and it's clinical effectiveness.

We describe a patient with adult T cell Leukemia to whom alpha-interferon therapy was highly effective. Although a combination chemotherapy (ACVP) first introduced was effective in reducing total leukocyte counts, the percentage of leukemic cells relative to total leukocyte counts was decreased first after the institution of alpha-interferon therapy. The patient is now under complete remission for four years. It was noted in this patient that circulating alpha-interferon, measured by a sensitive radioimmunoassay, was consistently low as compared with the value found in the age-, sex-matched healthy control (p less than 0.001). Since adult T cell leukemia is pathogenetically related to the retrovirus infection, low levels of circulating alpha-interferon of the patient may be important from both pathogenetic and therapeutic standpoints. Alpha-interferon therapy may be an useful additive for the chemotherapy of adult T cell leukemia.

Adult↗
PubMed1988

The restoration of proliferation and differentiation of peripheral blood mononuclear non-adherent cells into immunoglobulin-secreting cells by autologous synovial adherent cells from patients with rheumatoid arthritis.

The ability of enzyme-dissociated synovial adherent cells (SAC) obtained from patients with active rheumatoid arthritis to restore the proliferation and differention of peripheral blood mononuclear non-adherent cells (NAC) into immunoglobulin-secreting cells (ISC) was investigated. Autologous combinations of cells were used in this study to eliminate allogeneic reactions. Peripheral blood NAC, prepared by glass adherence and leucine methylester treatment to remove monocytes, almost completely lost their capacity to proliferate and differentiate into ISC in response to pokeweed mitogen. The response of NAC was restored by adding 12.5% of 'fresh SAC', which was obtained by glass-adherence after an overnight culture of non-rosette forming, enzyme-dissociated rheumatoid synovial cells. Although the response was also restorable by adding more than 25% fresh SAC, this was less satisfactory than adding 12.5% SAC. 'Old SAC', obtained by glass-adherence after 7 days culture of enzyme-dissociated synovial cells, did not restore the response of NAC. Immunohistochemical studies showed that 55% of fresh SAC and 3% of old SAC expressed HLA-DR antigens. When 100 units/ml of interferon gamma was present, 25% of old SAC remained HLA-DR-positive and some of these cells retained a dendritic morphology after 7 days culture. The results indicate that rheumatoid synovia contain macrophage-like cells that can effectively support the ultimate differentiation of lymphocytes to ISC.

Antibody-Producing Cells↗
PubMed1988

Virulence of Yersinia pseudotuberculosis isolated from pork and from the throats of swine.

Yersinia pseudotuberculosis was isolated from retail pork and from healthy swine throats. These wild-type strains and their representative cured isogenic strains were tested for the presence of plasmids and several virulence factors, and these characteristics were compared with those of virulent strains from humans. Two pork isolates (serotype IVB) and four swine isolates (serotypes IIB, IIC, III, and IVB) harbored a 42- to 48-megadalton plasmid which had similar fragmentation patterns resulting from digestion with restriction endonuclease. These six strains were lethal for mice via oral challenge and were positive in autoagglutination and calcium dependency tests. They also invaded HeLa cells and induced cytotoxicity. Histopathological examination and indirect fluorescent-antibody staining provided definite evidence of the pathogenicity of these strains when tissue sections from orally infected mice were used. The virulence factors of wild-type pork and swine isolates with the 42- to 48-megadalton plasmid were identical to those of two human isolates (serotypes IVB and VB). Hence, these pork and swine isolates should be considered potentially pathogenic for humans. The finding suggests that retail pork and swine may play an important role in the epidemiology of human infections caused by Y. pseudotuberculosis.

Agglutination Tests↗
PubMed1988

Yersinia pseudotuberculosis infection contracted through water contaminated by a wild animal.

We performed epidemiological studies on Yersinia pseudotuberculosis in one valley where a 3-year-old boy had been infected with Y. pseudotuberculosis serotype 4b in December 1982. Y. pseudotuberculosis serotype 4b was isolated from a water sample derived from a mountain stream from which the boy had drunk and from 1 of 41 rats trapped in the upper part of this stream in December 1986. The restriction endonuclease patterns of the plasmids in these isolates showed the rat and patient isolates to be identical but distinct from the water isolate. These data suggest the potential for transmission of Y. pseudotuberculosis through water contaminated by nondomesticated animals carrying this species.

Animals↗
PubMed1988

A review of the histopathological evidence on the pathogenesis of cartilage destruction in rheumatoid arthritis.

These are three ways of cartilage destruction as summarized in Fig. 1. The relative significance of the contribution among them to the pathogenesis of cartilage destruction varies individually. It appears important here to note that chondrocytes themselves are not actively involved in the pannus formation. Chondrocytes only provide a basis for extension of the pannus by proteolytic digestion of cartilage matrix. It is however possible in some individuals that the digestion of cartilage by chondrocytes plays the predominant role in their cartilage destruction. Besides the autonomous proliferative potential of pannus tissue, it seems evident that active synovitis is the main cause of cartilage loss. This is quite important from the therapeutic view point, because we can expect to halt the disease process causing joint deformities by controlling the active synovitis.

Antigen-Antibody Complex↗
PubMed1987

1 alpha,25-Dihydroxyvitamin D3 inhibits proliferative response of T- and B-lymphocytes in a serum-free culture.

The contribution of 1 alpha,25-dihydroxyvitamin D3 to the proliferative response of human B- and T-lymphocytes was examined in a serum-free culture, in which B-cells were stimulated with Staphylococcus aureus Cowan I, and T-cells with phytohemagglutinin, respectively. 1 alpha, 25-dihydroxyvitamin D3 inhibited mitogen-induced B-cell proliferation at a dose of 10(-7) M (P less than 0.01). T-cell proliferation was inhibited at the lower dose range between 10(-9) M and 10(-7) M. Thus, although 1 alpha, 25-dihydroxyvitamin D3 acts directly on B-cells, it appears that, under physiological circumstance, 1 alpha, 25-dihydroxyvitamin D3 regulates human B-cell growth indirectly through the effect on T-cells.

B-Lymphocytes↗
PubMed1987

Clinical studies of renal disease in Sjögren's syndrome.

When 17 patients with Sjögren's syndrome, without apparent clinical manifestations of renal disease, were examined renal function studies frequently indicated abnormalities in their renal phosphate handling. The percentage tubular reabsorption of phosphate (%TRP) was decreased in six (35.3%), and maximal tubular reabsorption rate for phosphate (TmPO4/GFR) was low in eight (47.1%). In contrast, indices of renal calcium handling and serum parathyroid hormone levels were normal, suggesting that the abnormalities of phosphate metabolism were due not to extrinsic, but rather to intrinsic disease processes occurring in the kidney in Sjögren's syndrome. When the patients were divided into two groups according to the presence or absence of a renal tubular acidification defect (RTAD), patients with RTAD were younger (p less than 0.005), had longer disease duration (p less than 0.01), lower creatinine clearance (p less than 0.05), and higher incidence of low %TRP (p less than 0.05). Thus the patients with lower creatinine clearance generally had disease of longer duration at diagnosis and tended also to have defects in concentrating and acidifying the urine.

Adult↗
PubMed1986

A sensitive radioimmunoassay for alpha-interferon: circulating alpha-interferon-like substance in the plasma of healthy individuals and rheumatoid arthritis patients.

A radioimmunoassay for circulating alpha-interferon (IFN alpha) has been developed using lymphoblastoid IFN alpha. The assay was specific for IFN alpha, and did not cross-react with IFN beta, IFN gamma, or ACTH, while it was specifically inhibited by recombinant IFN alpha. The radioimmunoassay (y) correlated linearly with the virus inhibition assay (x), with a regression line of y on x of y = 0.659x + 245 (u) (P less than 0.01). alpha-Interferon-like substance (IFN alpha-LS) was extracted and concentrated from plasma either by silicic acid or by antibody immunoadsorption. Serial dilutions of plasma and extracted samples of plasma showed dilution curves identical to those of standard IFN alpha, suggesting the presence of endogenous IFN alpha in human plasma. The circulating IFN alpha-LS of healthy individuals aged 20 to 45 was 0.207 +/- 0.055 ng/ml in males (n = 48) and 0.172 +/- 0.076 ng/ml in females (n = 34). Gel filtration studies on a Sephadex G-75 column suggested that circulating IFN alpha-LS exists in a fragmented form, inactive in virus inhibition assays, in the plasma of healthy individuals. The finding may help explain why biological IFN alpha is often undetectable in the plasma of healthy donors, yet is detectable by radioimmunoassay. Circulating IFN alpha-LS in the plasma of healthy individuals declined gradually with age. IFN alpha-LS was significantly decreased in the plasma of rheumatoid arthritis patients, when compared with the value found in the age and sex-matched healthy controls and in osteoarthritis patients (P less than 0.0001). The decrease was related neither to treatment nor to disease activity. IFN alpha-LS was, however, not decreased in the plasma of vasculitis patients. Decreased IFN alpha-LS in rheumatoid arthritis may be important from pathogenetic and therapeutic standpoints.

Adult↗
PubMed1985

Quantitative histologic studies on the pathogenesis of periarticular osteoporosis in rheumatoid arthritis.

The pathogenesis of periarticular osteopenia in rheumatoid arthritis (RA) was investigated by histomorphometry on juxtaarticular bone removed during joint surgery. Twenty areas from 12 RA patients were compared with 14 areas from 6 osteoarthritis (OA) patients. There was no difference between the 2 groups in the percent of total bone volume. However, increased bone formation was suggested by an increase in the percent of active osteoid surface in RA compared with that in OA. Bone resorption was also increased in RA, as evidenced by increases versus OA in percent total resorptive surface, percent active resorptive surface, and number of osteoclasts. These results demonstrate increased turnover of bone in RA, especially in the resorptive phase of the periarticular trabecular bone. It is proposed that soluble factor(s) synthesized in the contiguous rheumatoid synovium may be transferred to the periarticular bone space, stimulating osteoclasts to resorb bone.

Adrenal Cortex Hormones↗
PubMed1985

Suppression of tuberculin hypersensitivity caused by rubella infection.

During an outbreak of rubella, more than 4,000 primary schoolchildren who had been vaccinated with BCG before entrance were tested with tuberculin. According to the status of rubella infection, they were grouped into 3 groups: those having experienced the disease long ago, those having shown clinical manifestations of rubella during this epidemic, and those without any evidence of past or recent disease. There was a significant depression of mean reaction size for the second group compared with those in the other two. The breakdown of the second group into 4 subgroups according to the time interval between the tuberculin test and the time of onset of the disease made it clear that the reaction was smallest within 20 days after onset and that it was then gradually restored to the healthy level after 30 days. There was no evidence of suppression of hypersensitivity among subclinical infection cases. Methodologic problems concerning tuberculin data analysis in this kind of research are discussed, with an emphasis on the importance of a quantitative approach to these considerations.

Child↗
PubMed1985

1 alpha,25-dihydroxyvitamin D3 inhibits pokeweed mitogen-stimulated human B-cell activation: an analysis using serum-free culture conditions.

The effect of 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on pokeweed mitogen-induced generation of human immunoglobulin-secreting cells (ISC) was studied in serum-free culture. Human peripheral blood mononuclear cells (1.75 X 10(6)/ml) were cultured in 200 microliter microculture wells containing Iscove's MEM supplemented with 20 micrograms/ml of human transferrin, 20 micrograms/ml of soybean lecithin and 1 mg/ml of delipidated bovine albumin. The culture supported ISC generation of all isotypes, and the optimal concentration of pokeweed mitogen was 1 microgram/ml. After stimulation with a suboptimal concentration (0.3 micrograms/ml) of pokeweed mitogen, 1,25-(OH)2D3 suppressed the ISC generation at a dose range between 10(-9) M and 10(-7) M, and maximal inhibition was obtained at 10(-7) M. 1,25-(OH)2D3 had no effect on the spontaneous ISC generation. The effect was specific for 1,25-(OH)2D3 and no suppression was obtained by 24R,25-dihydroxyvitamin D3 or 25-hydroxyvitamin D3.

Antibody-Producing Cells↗
PubMed1984

Fibronectin on the surface of articular cartilage in rheumatoid arthritis.

The presence of fibronectin on the surface of articular cartilage in rheumatoid arthritis (RA) was investigated. Cartilage samples were stained by the immunoperoxidase method using anti-human fibronectin antibody, and observed under light and electron microscopy. Fibronectin was present on the articular surface in 7 of 8 RA patients. The degree of staining varied greatly among the patients. Five of 8 patients were positive for fibronectin in 50% or more of the cartilage areas studied. In total, fibronectin was observed in RA. Fibronectin was not observed in cartilage samples of osteoarthritic joints or joints which were not diseased but had undergone trauma. Ultrastructurally, it was observed to be associated with collagen fibrils and amorphous substance in the matrix. The fibronectin-negative surface of the rheumatoid cartilage was usually thick ultrastructurally, compared with the fibronectin-positive surface, and the staining for fibronectin roughly correlated with decreased proteoglycans on the surface. The presence of fibronectin in the matrix appeared to be revealed by partial degradation of proteoglycans with proteolytic enzymes in the synovial fluid, as well as by the deposition of fibronectin onto the surface of rheumatoid cartilage. Fibronectin on the articular surface may play an important role in promoting pannus extension onto the articular surface in RA.

Arthritis, Rheumatoid↗