Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 361 records · Page 20Linked to original sources

PubMed1995

Anti-HLA antibody screening with extracted platelet HLA antigens by the mixed passive hemagglutination method.

For the detection of anti-HLA antibody in the serum of patients receiving frequent platelet transfusions, we developed a new method in which platelet antigens are extracted into physiological saline containing 3% sucrose and coated as a layer on a U-type Terasaki plate. In the present study, screening of anti-HLA antibodies was conducted with this plate by the mixed passive hemagglutination test although the plate contained both HLA and HPA. The reactivity determined by this method correlated well with antihuman immunoglobulin-lymphocyte cytotoxicity test (AHG-LCT) results (r = 0.963). The plate can be preserved for at least 2 years at -80 degrees C and is easier to handle than the frozen lymphocyte panels used in the LCT test in which lymphocytes must be kept alive. This new method is an alternative way to screen HLA antibodies. In addition, it is expected that this method will be used to screen anti-HPA antibodies.

Blood Platelets↗

PubMed1995

Some binding properties of the envelope of Porphyromonas gingivalis to hemoglobin.

Porphyromonas gingivalis was found to bind to hemoproteins (hemoglobin, myoglobin, catalase, cytochrome c) and the binding properties of the envelope of P. gingivalis to hemoglobin were investigated. Maximum amount of hemoglobin bound to 1 mg of the envelope was 58 micrograms. No significant binding was observed at 4 degrees C and the binding was inhibited strongly by tosyl-L-lysine chloromethyl ketone, Leupeptin, EDTA and partially by meta-periodate. Heating of the envelope at 70 degrees C for 15 min resulted in complete loss of the binding activity. The binding activity of the envelope was not influenced by the treatment with the endogenous proteases. The envelope saturated with hemoglobin could no longer bind to other hemoproteins tested, indicating that binding site for these hemoproteins are common.

Hemoglobins↗

PubMed1995

Effect of Campylobacter rectus LPS on plasminogen activator-plasmin system in human gingival fibroblast cells.

The plasminogen activator (PA)-plasmin system is implicated in the degradation of the extracellular matrix in inflammation through activation of metalloproteases and prekallikrein. We examined the activation of the PA-plasmin system in human gingival fibroblast cells (Gin-1 cells) following treatment with lipopolysaccharide (LPS) from Campylobacter rectus, which is frequently detected at sites of periodontal disease. The C. rectus LPS stimulated the plasmin activity in the conditioned medium of Gin-1 cells in a time- and dose-dependent manner, and C. rectus LPS also stimulated the PA activity in the conditioned medium. The PA produced by Gin-1 cells was determined to be urokinase PA (uPA), as preincubation of Gin-1 conditioned medium with anti-uPA antiserum completely inhibited the PA activity while that with anti-tPA antiserum had no inhibitory effect. The concentration of PA inhibitor-1 (PAI-1) in the conditioned medium was decreased by the addition of C. rectus LPS. Therefore, the enhancement of plasmin activity in the conditioned medium was dependent on increased uPA activity via the decrease of the PAI-1 level of Gin-1 cells treated with C. rectus LPS. Furthermore, the conditioned medium of Gin-1 cells treated with C. rectus LPS showed significantly increased kallikrein activity, indicating the conversion of prekallikrein to kallikrein, which converts kininogen into kinin. These findings suggest that C. rectus LPS is a potent stimulator of inflammation of gingival tissue which acts through stimulation of the PA-plasmin system.

Campylobacter↗

PubMed1995

Dual functions of the AML1/Evi-1 chimeric protein in the mechanism of leukemogenesis in t(3;21) leukemias.

The chromosomal translocation t(3;21)(q26;q22), which is found in blastic crisis in chronic myelogenous leukemias and myelodysplastic syndrome-derived leukemias, produces AML1/Evi-1 chimeric transcription factor and is thought to play important roles in acute leukemic transformation of hemopoietic stem cells. We report here the functional analyses of AML1/Evi-1. It was revealed that AML1/Evi-1 itself does not alter the transactivation level through mouse polyomavirus enhancer-binding protein 2 (PEBP2; PEA2) sites (binding site of AML1) but dominantly suppresses the transactivation by intact AML1, which is assumed to be a stimulator of myeloid cell differentiation. DNA-binding competition is a putative mechanism of such dominant negative effects of AML1/Evi-1 because it binds to PEBP2 sites with higher affinity than AML1 does. Furthermore, AML1/Evi-1 stimulated c-fos promoter transactivation and increased AP-1 activity, as Evi-1 (which is not normally expressed in hemopoietic cells) did. Experiments using deletion mutants of AML1/Evi-1 showed that these two functions are mutually independent because the dominant negative effects on intact AML1 and the stimulation of AP-1 activity are dependent on the runt domain (DNA-binding domain of AML1) and the zinc finger domain near the C terminus, respectively. Furthermore, we showed that AML1/Evi-1 blocks granulocytic differentiation, otherwise induced by granulocyte colony-stimulating factor, of 32Dcl3 myeloid cells. It was also suggested that both AML1-derived and Evi-1-derived portions of the fusion protein play crucial roles in this differentiation block. We conclude that the leukemic cell transformation in t(3;21) leukemias is probably caused by these dual functions of AML1/Evi-1 chimeric protein.

3T3 Cells↗

PubMed1995

Estramustine phosphate for preventing flare-up in luteinizing hormone-releasing hormone analogue depot therapy.

The usefulness of estramustine phosphate (ECT) for preventing flare-up in goserelin acetate depot therapy for advanced prostate cancer was studied. Pretreatment with ECT 560 mg daily for 3 weeks almost completely prevented the rise in testosterone level seen in goserelin acetate depot therapy and no signs or symptoms of tumor flare were observed. Long-term ECT completely blocked the rise in luteinizing hormone and testosterone level, but ECT at this dosage was likely to cause complications. The administration of ECT 560 mg daily for 3 weeks prior to goserelin acetate depot therapy was considered sufficient to prevent tumor flare, and its effect was considered to be more marked than that of short-term treatment with antiandrogens.

Acid Phosphatase↗

PubMed1995

Inhibition of prostaglandin E2 and interleukin 1-beta production by low-power laser irradiation in stretched human periodontal ligament cells.

It is well-known that orthodontic treatment usually causes some discomfort and pain to the patients. Recently, it has been reported that low-power laser irradiation is effective in reducing the pain accompanying tooth movement. However, the mechanism of such pain relief cannot be elucidated. Since high levels of prostaglandin (PG) E2 and interleukin (IL)-1 beta are found in the periodontal ligament (PDL) during tooth movement, and both factors are involved in the induction of pain, the effects of low-power laser irradiation on PGE2 and IL-1 beta production in stretched human PDL cells were studied in vitro. The PDL cells, derived from healthy premolars extracted for orthodontic treatment, were utilized for experiments. Cells were seeded in flexible-bottomed culture plates, and the bottom of each plate was elongated (18% increase) under vacuum at 6 cycles per min for 1, 3, or 5 days. The stretched cells were irradiated with a Ga-Al-As low-power diode laser (60 mW) once a day for 3, 6, or 10 min (from 10.8 to 36.0 J) for 1, 3, or 5 days. PGE2 and IL-1 beta levels in the medium were measured by radioimmunoassay. In response to mechanical stretching, human PDL cells showed a marked elevation in PGE2 production in a time-dependent manner. IL-1 beta production was also elevated, but this remained constant. The increase in PGE2 production was significantly inhibited by laser irradiation in a dose-dependent manner. The increase in IL-1 beta production was also significantly inhibited by laser irradiation, although the inhibition was only partial.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1995

Induction and regulation of connexin26 by glucagon in primary cultures of adult rat hepatocytes.

In the adult rat hepatocyte, the gap junction proteins consist of a major component, connexin32 (Cx32) and a minor component, connexin26 (Cx26). Although we recently reported our success in inducing and maintaining Cx32 in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor and 2% dimethyl sulfoxide, it was very difficult to induce Cx26 in the primary hepatocytes. In the present study, we found that the addition of 10(-7) M glucagon into the culture medium could dramatically induce Cx26 mRNA and protein. Although the expression of Cx32 mRNA was also influenced by glucagon, the increase of the expression was small. Immunocytochemically, Cx26-positive spots were observed between most adjacent cells and were co-localized with the Cx32-positive spots. We also examined whether 0.5 mM dibutyl cyclic AMP could induce expression of Cx26 in the cells. The effect of dexamethasone on the expression of Cx26 mRNA compared to that of Cx32 mRNA was examined. For the induction and maintenance of Cx26 mRNA, more than 10(-7) M dexamethasone was necessary in this culture. These results suggest that expression of Cx26 in hepatocytes may be regulated by the concentrations of glucagon and glucocorticoid hormones.

Animals↗

PubMed1995

Benzylphthalimides and phenethylphthalimides with thalidomide-like activity on the production of tumor necrosis factor alpha.

Benzylphthalimide analogs (P1P's) and phenethylphthalimide analogs (P2P's) have been found to exhibit thalidomide-like activity on the production of tumor necrosis factor (TNF)-alpha by the human leukemia cell line, HL-60, stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA). Structure-activity relationships are discussed on the basis of the TNF-alpha production-enhancing activity. Benzylphthalimide (P1P-00) exhibited which is weaker than that of thalidomide, but introduction of a methyl group at the ortho-position of the benzyl moiety (P1P-10) resulted an increase to a level comparable with that of thalidomide. Phenethylphthalimide (P2P-00) is more potent than thalidomide, and its fluorinated derivative, 2-phenethyl-4,5,6,7-tetrafluoro-1H-isoindole-1,3-dione (FP2P-00), exhibited potent activity at very low concentrations.

HL-60 Cells↗

PubMed1995

N-Alkylphthalimides: structural requirement of thalidomidal action on 12-O-tetradecanoylphorbol-13-acetate-induced tumor necrosis factor alpha production by human leukemia HL-60 cells.

Phthalimide analogs N-substituted with n-butyl, tert-butyl, hexyl and adamantyl groups were designed and prepared as simplified analogs of thalidomide and methylthalidomide. All the compounds prepared except N-n-butylphthalimide showed thalidomidal activity on 12-O-tetradecanoylphorbol-13-acetate-induced tumor necrosis factor (TNF)-alpha production by human leukemia HL-60 cells. Among the investigated compounds, including thalidomide and methylthalidomide, N-adamantylphthalimide showed the most potent TNF-alpha production-enhancing activity.

Humans↗

PubMed1995

Toxicity and properties of the extract from Sarcocystis cruzi cysts.

The extract from Sarcocystis cruzi cysts in bovine muscle was subcutaneously injected to mice, guinea pigs, chickens, and rabbits to detect its toxicity. Only rabbits showed reactions after administration of the extract at a dose of 25 micrograms. The main clinical signs of the rabbits were depression, reduction in body temperature and intermittent diarrhea and the hematological findings observed were elevation in WBC, RBC, PCV, TP, BUN, AST, AUT and creatinine values and reduction in glucose, K+ and pH of blood. The extract, crude toxin, was a water soluble, acid-alkali stable and thermolabile protein and estimated to be a molecular mass of 15-16 kd.

Animals↗

PubMed1995

Immunophenotypes of Reed-Sternberg cells and their variants: a study of 68 cases of Hodgkin's disease.

Utilizing a panel of monoclonal and polyclonal antibodies, routine paraffin sections in 68 cases of Hodgkin's disease were examined for the presence of immunoreactivity in Reed-Sternberg (R-S) and related cells by the avidin-biotin-peroxidase complex (ABC) technique. In 14 cases of lymphocyte-predominant Hodgkin's disease (LPHD), R-S cells and the polyploid lymphocytic and histiocytic (L & H) variants of R-S cells were immunoreactive for L26 and alpha 1-antitrypsin (alpha 1-AT) in 9 (64%) and 6 (43%), respectively, whereas the remaining antibodies were negative or rarely positive against L & H variants of R-S cells. R-S cells in 24 cases of mixed cellularity Hodgkin's disease (MCHD) were positive with alpha 1-AT in 63% of cases, positive with LN3 in 71% of cases and positive for BerH2 in 92% of cases. The lacunar cell type of R-S cells in 19 cases of nodular sclerosing Hodgkin's disease (NSHD) were reactive for alpha 1-AT in all cases, BerH2 in 18 cases (95%), and LN3 in 17 cases (89%). Pleomorphic variant of R-S cells in 11 cases of lymphocyte depleted Hodgkin's disease (LDHD) showed reactivity with alpha 1-AT in 9 cases (82%), BerH2 in 6 cases (55%), and LN3 in 9 cases (82%). The incidence of L26 in R-S cells was higher in LPHD than in other three subtypes, whereas the immunohistochemical finding of alpha 1-AT had reverse relevance to the result of L26. The incidence of BerH2 in MCHD and NSHD was higher than that of this antibody in the whole of Hodgkin's disease. R-S cells in NSHD and LDHD were highly positive to LN3, and detection rate of these two types was higher than that in the whole of Hodgkin's disease. No cases showed immunoreactivity with anti-T-cell antibodies (CD3, UCHL1 and DFT1), a marker for natural killer cell (Leu7), and a marker for interdigitating reticulum cell (S-100 protein). These results suggest that correlation between predominant staining pattern and R-S cells and variants thereof in each histological subtype of Hodgkin's disease are as follows: LPHD shows L26+, alpha 1-AT-, BerH2-; MCHD and NSHD show L26-, alpha 1-AT+, BerH2+; and LDHD shows L26-, alpha 1-AT+, BerH2+ or L26+, alpha 1-AT+, BerH2-.

Antibodies, Monoclonal↗

PubMed1995

Osteomas of the skull: comparison of magnetic resonance imaging and histological findings.

Magnetic resonance (MR) images of five patients with osteomas of the skull and six patients with other primary skull tumors were reviewed. All osteomas appeared as low-intensity areas on T1-weighted images. T2-weighted images showed homogeneous low-intensity areas in two dense osteomas, a high-intensity area in one spongy osteoma, and mixed intensity areas in two mixed spongy and dense osteomas, respectively. The signal intensities of osteomas on T2-weighted MR images correlated well with the histological findings. Other skull tumors showed no specific MR imaging appearance.

Adolescent↗

PubMed1995

Effect of lymphokine-activated killer cells with or without radiation therapy against malignant brain tumors.

The use of autologous lymphokine-activated killer (LAK) cells to treat malignant brain tumors was evaluated in 10 patients, one with metastatic malignant melanoma and nine with malignant glioma. LAK cells were obtained by culturing autologous peripheral blood lymphocytes with human recombinant interleukin-2 (rIL-2) for 7-28 days. All patients underwent surgery to remove as much tumor as possible and an Ommaya reservoir was implaced in the tumor cavity. Two of the 10 patients had received radiotherapy elsewhere, so were treated with LAK cells alone. Eight patients were treated with a combination of LAK cells and radiotherapy, using 1.8-2.0 Gy fractions given five times a week with a total dosage between 54 and 65 Gy. LAK cells and rIL-2 were injected to the tumor cavity via the Ommaya reservoir once a week for inpatients and once a month for outpatients. The duration of the LAK therapy ranged from 3 to 23 months (mean 13.7 mos). Neuroimaging evaluation revealed two complete responses, three partial responses, four no changes, and one progressive disease. In one patient with pontine glioma, the Karnofsky performance score was raised from 20 to 60. There were no side effects after the injection of LAK cells and rIL-2. The results suggest low-dose LAK therapy is a useful and safe treatment modality for malignant brain tumors.

Adult↗

PubMed1995

[Comparison by SES-PAGE of molecular weights of lipopolysaccharides from Campylobacter jejuni Lior serotype reference strains and clinical isolates].

To compare the molecular weights (MWs) of lipopolysaccharides (LPSs) from 30 Lior serotype reference strains and 17 clinical isolates of Campylobacter jejuni, we analyzed their migration rates by SDS-PAGE and the silver staining of the gel. LPSs from the serotype strains showed one band in the low-molecular-weight region of the gel as did those from R mutants of enterobacteria. Based on those from Salmonella minnesota R mutants, MWs of LPSs from C. jejuni strains were calculated to fall within a range of 3900 to 5300. Furthermore, in comparison of MWs of LPSs from the clinical isolates with those from the same serotype reference strains, six out of eight serotypes did not coincide each other. These results indicate that the Lior method is unrelated with the Penner method in the serotyping of C. jejuni.

Campylobacter jejuni↗

PubMed1995

[Characterization by RFLP of DNAs from Campylobacter jejuni Lior serotype reference strains and clinical isolates and detection of C. jejuni by DNA-probe].

The Lior serotype reference strains and clinical isolates of Campylobacter jejuni were compared in the restriction fragment length polymorphism (RFLP) pattern to distinguish C. jejuni strains. These reference strains showed RFLP patterns different from one to another, while the patterns of some isolates were not coincident with those of the same serotype reference strains. Furthermore, we tried to hybridize HindIII-digested fragments from these strains with the DNA probe encoding the 46-kDa protein of C. jejuni by Southern and slot blottings. The 1.8-kbp fragments from all strains of C. jejuni hybridized with this probe, but those from other species of Campylobacter or enterobacteria did not. These results indicate that the Lior serotype is unrelated with the RFLP pattern of DNA of C. jejuni strains, but the DNA probe is useful to detect C. jejuni.

Campylobacter jejuni↗

PubMed1995

Annexin V is localized in association with Z-line of rat cardiac myocytes.

OBJECTIVE: The aim of this study was to characterize a 33-kDa protein (p33) isolated from bovine liver and to determine the subcellular localization of the protein in rat cardiocytes as well as in non-cardiac tissues. METHODS: Cycles of calcium-induced precipitation coupled with EGTA-resolubilization were used to isolate crude annexins from bovine and rat tissues. Column chromatography was performed to purify the p33 from the crude annexins. The protein was identified as annexin V by partial amino acid sequence determination. Specificity of anti-annexin V antibody was examined by using Western blotting after one- or two-dimensional electrophoresis. For characterization of the protein, immunofluorescence microscopy and actin-binding assays were carried out. RESULTS: Immunofluorescence microscopy showed that annexin V was stained as a striated pattern along myofibrils on frozen sections of both atria and ventricles of adult rats. The striations were seen more clearly in cultured rat atrial myocytes. Examination of doubly stained cardiocytes with anti-annexin V and anti-alpha-actinin by a confocal laser scanning microscope suggests that annexin V is localized in association with the Z-line of rat cardiac myocytes. We also found that annexin V was stained intensely in actin-rich regions of non-cardiac tissues such as bile canaliculi of rat liver and brush border-terminal web region in the epithelial cells of both small intestine and kidney proximal tubular cells. F-actin binding experiments revealed that annexin V failed to bind to F-actin directly in vitro. CONCLUSION: Our results suggest that annexin V is a new component of the Z-line in rat cardiocytes and might be involved in regulation of its organization.

Actins↗

PubMed1995

[Endoscopic treatment of esophageal and gastric cancers].

Since 1978 we have applied various endoscopic procedures to esophageal and gastric malignancies for a palliative or a radical purpose. An outline of our experience was presented herein. Endoscopic Laser irradiation has been given to 61 cases (64 lesions) of early gastric cancers as a radical treatment since 1978. The irradiation was repeated once a week until getting disappearance of cancer cells in biopsy specimens. The Laser irradiation has also been given to 13 cases of advanced gastric cancers since 1978 and 12 cases of advanced esophageal cancers since 1985 for palliative purposes, such as, mass reduction, hemostasis, and removals of stenosis or obstruction. From 1991 the endoscopic mucosal resection (EMR) method has been used to 75 cases (93 lesions) as a radical treatment for gastric adenomas (n = 24) and well-differentiated adenocarcinomas less than 2 cm in size without ulceration (n = 69). The endoscopic Laser irradiation for early gastric cancers showed a survival rate of 62.8% after 5 years. The recurrence was preferentially found in depressed cancers and polypoid cancers of more than 3 cm in size, and often appeared within one year after the treatment. The Laser treatment for advanced gastric and esophageal cancers showed a survival rate of 69% and 33% after 6 months, respectively. In many cases, subjective symptoms like gastric bleeding or dysphasia were markedly improved after the treatment. The complete removal of gastric tumors was obtained at 65% with the conventional strip biopsy method, and at 80% with the double snare polypectomy or EMR using the EVL device.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

[Clinical analysis of ureteral injuries].

Six cases of ureteral injuries were analyzed. Two cases were male and 4 cases were female. The right side was affected in 1 case and the left in 5 cases. The affected portion was the uretero-pelvic junction in 1 case and lower iliac vessels in the other cases. Five cases were iatrogenic injuries in surgical or gynecological pelvic operation, and the other was due to blunt trauma. Intraoperative diagnosis was made in 4 cases. Drain leakage led to diagnosis in one case and pyelonephritis in another. Ureteroureterostomy was performed in 2 cases, pyeloureterostomy in 1 case, ureteroneocystostomy with psoas hitch in 1 case, Boari bladder flap in 1 case and simple suture in 1 case. 4-0 or 5-0 Dexon with an atraumatic needle was used for all anastomoses. Except for case 1, who died of the recurrence of carcinosarcoma, renal functions were preserved in all patients during the follow-up period ranging from 5 months to 7 years 8 months.

Adult↗