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Biomedical subjects

T Yoshiki

Publications and source records attributed to T Yoshiki.

At least 109 records · Page 6Linked to original sources
PubMed1994

Ultrastructural and immunohistochemical characterization of basal cells in three-dimensional culture models of the skin.

Keratinocytes were cultured on fibroblast-free dermal substitutes made of type I collagen film (collagen dermal substitute) and an extracellular matrix gel film (matrix dermal substitute), each of which was laid on a lyophilized type I collagen sponge. The morphology of the basal keratinocytes in these three-dimensional culture models of the skin was studied ultrastructurally and immunohistochemically to assess their differentiation to basal cells. The basal keratinocytes in the artificial epidermis cultured on the collagen dermal substitute showed poorly organized tonofibril networks and desmosomes. Neither the tonofibril-hemidesmosome complex nor the lamina densa were detected along the interface, where many cytoplasmic projections of basal keratinocytes were noted. There were no detectable antigens of type IV or VII collagen, LDA-1, or laminin in the interface. Bullous pemphigoid (BP) and 1-2B7B antigens and integrins were expressed along the cytoplasmic membrane and the projections of the basal keratinocytes. A high molecular weight keratin (keratin 1, 68 kDa, 34 beta B4) was detected only in part of the uppermost layers of this artificial epidermis. In contrast, basal keratinocytes in the artificial epidermis on the matrix dermal substitute developed tonofibril networks radiating to desmosomes and hemidesmosomes, under which a primitive lamina densa was present. Basement membrane zone antigens, such as type IV and VII collagens, LDA-1 and laminin were noted along the interface as were 1-2B7B and BP antigens and integrins. Laminin and type VII collagen were also detected along or in the membrane of the endoplasmic reticulum of basal keratinocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Basement Membrane↗
PubMed1994

Genetic heterogeneity of dominantly inherited olivopontocerebellar atrophy (OPCA) in the Japanese: linkage study of two pedigrees and evidence for the disease locus on chromosome 12q (SCA2).

We did a linkage study of 2 multigenerational pedigrees with dominant olivopontocerebellar atrophy (OPCA) other than SCA1, with chromosome 12q microsatellites. Multipoint linkage analysis led to the conclusion that the disease locus locates within the 6.2 cM interval between IGF1 and D12S84/D12S105. This result coincides with that of Cuban ataxia pedigrees designated as SCA2. Our study provides genetic evidence that dominant OPCA in the Japanese consists of at least two genetically different disorders; SCA1 and SCA2.

Adolescent↗
PubMed1994

Lymphokine-activated killer cytotoxicity against pancreas adenocarcinoma cell lines and vascular endothelial cells.

Eight pancreas carcinoma cell lines of duct cell origin (PCI-6, 10, 19, 24, 35, 43, 55, and 64) were established. Using one of these lines, PCI-24, human umbilical vein endothelial cells (HUVEC), and several recombinant cytokines, conditions and specificity of anti-PCI LAK induction were investigated, with the focus on a search for lymphokine-activated killer (LAK) activity that differentiates neoplastic (PCI) from non-neoplastic (HUVEC) cells. Interferon-gamma (IFN-gamma), IFN-alpha, IL-4, IL-6, and IL-7, but not tumor necrosis factor-alpha (TNF-alpha) or IL-1 beta, induced a weak LAK activity against PCI-24, whereas IL-2-induced (1000 U/mL) LAK exhibited a far more potent cytotoxicity. When these cytokines were added at the suboptimal dose IL-2 (100 U/mL), no significant augmentation in LAK activity was induced. Staphylococcal protein A (SpA) induced LAK activity as potent as that seen with IL-2 (1000 U/mL). Both IL-2-induced and SpA-induced LAK had a potent, dose-dependent cytotoxicity against HUVEC. HUVEC inhibited both IL-2- and SpA-induced LAK cytotoxicity against PCI-24 to almost the same extent as seen with PCI-24. Thus, two potent LAK-inducers did not generate LAK activity that differentiates neoplastic from non-neoplastic cells. Thus, in vitro cytotoxicity of LAK against non-neoplastic endothelial cells is unavoidable when handling cytokines in LAK induction.

Adenocarcinoma↗
PubMed1994

Analysis of restriction fragment length polymorphism for the HLA-DR gene in Japanese patients with sarcoidosis.

BACKGROUND: It is commonly assumed that some immunological disorder may play a part in the pathogenesis of sarcoidosis. Previous studies by several groups have shown a significant association with HLA-DR antigens in patients with sarcoidosis. In this study, restriction fragment length polymorphism (RFLP) analysis of the HLA-DR gene was designed to confirm the association at the gene level and to look for a gene rearrangement which may influence susceptibility to sarcoidosis. METHODS: Thirty two unrelated Japanese patients with sarcoidosis were tested for HLA antigens and subjected to RFLP analysis after digestion with Eco RI, Pst I, Bam HI, Pvu II, and Hind III by using an HLA-DR beta cDNA probe. A group of 47 unrelated healthy Japanese subjects served as controls. Frequencies of each restriction fragment were compared between the patients and the control subjects. Correlation between fragment frequencies and clinical features were also analysed. RESULTS: No restriction fragments of HLA-DR beta gene were found specific to the patients with sarcoidosis. The RFLP analysis could detect polymorphism of HLA-DR beta genes that was not distinguishable by conventional serological methods. Several restriction fragments of the DR beta gene were seen only in DRw52 positive individuals, and showed higher frequencies in the patients than in control subjects. The patients with these DNA fragments were likely to have limited stage disease with no ophthalmic involvement. CONCLUSIONS: An association between HLA and sarcoidosis was noted at the DNA level, although no restriction fragments were specific for this disease. RFLP analysis of the HLA gene is a more useful method than the usual HLA typing, and should be the first step in identifying the gene sequence which is connected with susceptibility to sarcoidosis.

Adolescent↗
PubMed1994

[Pathways leading to intractable vasculitis syndromes: a review].

Intractable vasculitis syndromes are reviewed in terms of pathways leading to the diseases. The III-type, IV-type, and II-type allergic reaction, as well as angiospasm and endothelial dysfunction pathways are important in the pathogenesis of vasculitis. Each pathway has been described, using appropriate animal models or experimental and clinical data. Antigens of microorganisms are, among others, important pathogenic factors, activating several pathways. Endogenous retroviral antigens in the mouse, and possibly in humans, cause vasculitis through the II-type and III-type hypersensitivity, and experiments on the intractable vasculitis remain to be focused on this point.

Animals↗
PubMed1994

[HAM rat disease: an animal model of HTLV-I infection].

We have established a model of HTLV-I infection in the WKAH rat strain. By inoculating MT-2, an HTLV-I producing human T cell line, HAM rat disease, a demyelinating disease resembling human HAM/TSP, developed in the WKAH rat strain. The affected lesion in the HAM rat disease is distributed symmetrically in the lateral and anterior funiculi of the thoratic spinal cord similar to that of HAM/TSP, and the histological features are also mimicked except for infiltration of lymphocytes. Using this model, it is suggested that the apoptosis of oligodendrocyte appears to be the most important process implicated in the demyelinating process of the spinal cord. The pathogenesis of HAM/TSP is also discussed herein.

Animals↗
PubMed1994

Carcinosarcoma of the ureter with unusual histologic features.

We report a rare case of carcinosarcoma of the ureter presented as a retroperitoneal tumor. The tumor originated in the ureter as a polypoid protrusion and spread around peri-ureteral, retroperitoneal tissues. The polypoid ureteral tumor was composed of an intra-epithelial carcinoma and a submucosal mesenchymal tumor; the histology of the retroperitoneal tumor in the original site was that of a carcinosarcoma. The bulk of the tumor in the retroperitoneum was composed of blastematous, epithelial and sarcomatous neoplastic cells with foci resembling an incomplete glomeruloid formation, thus mimicking a Wilms' tumor. The lesion appeared to originate from multipotential cells in the mucosal layer of the ureter. Whether or not this tumor has a true nephrogenic property is currently unknown. When a retroperitoneal tumor of the adult resembling a Wilms' tumor is found, one should suspect a possible carcinosarcomatous origin in the ureter.

Aged↗
PubMed1994

Massive apoptosis in infantile myofibromatosis. A putative mechanism of tumor regression.

Two cases of solitary infantile myofibromatosis (IM) are presented. Solitary IM are tumors prone to spontaneous regression. Histopathologically, several tumor lobules in our IM cases had central areas of massive cell death, with nuclear pyknosis, cytoplasmic hyalinization and nuclear fragmentation but without lymphoid or neutrophilic cell infiltration. These central cell death areas consisted of about 40% in case 2 and 50% in case 1 of the entire tumor tissues, respectively. Electron microscopy revealed that the condensed nuclei and cytoplasm were fragmented into "apoptotic bodies", with or without phagocytosis by histiocytes. DNA fragmentation, as evidenced by the terminal deoxy transferase-mediated uptake of biotinylated dUTP, was identified at massive cell death areas on paraffin sections from both cases. A characteristic 180- to 190-bp nucleosomal ladder was detected in DNA obtained from the tumor cells in case 1. The collective evidence suggested that these tumors underwent a central, massive apoptosis. As massive cell death similar to that seen in the present cases has been described in other documented cases of IM, we propose that the spontaneous regression that frequently occurs with this type of tumor may be mediated by massive apoptotic cell death.

Actins↗
PubMed1993

Importance of E-selectin (ELAM-1) and sialyl Lewis(a) in the adhesion of pancreatic carcinoma cells to activated endothelium.

Adhesion molecules involved in attachment between human pancreatic carcinoma and activated endothelial cells in vitro were investigated. Basal adhesion occurred between 6 pancreatic carcinoma cell lines and unstimulated human umbilical vein endothelial cells (HUVEC), and augmented basal adhesion to activated HUVEC was only seen when pancreatic cancer cells expressed sialyl Lewisa (SLea) and sialyl Lewisx (SLex). Activation of HUVEC with interleukin 1-beta (IL-1 beta) or tumor necrosis factor-alpha (TNF-alpha), but not with interferon-gamma (IFN-gamma), generated the augmentative basal adhesion. Dose dependence and additive effect were observed in augmentation of the basal adhesion induced by IL-1 beta and/or TNF-alpha. Increase in adhesion correlated with up-regulation of the surface E-selectin (or ELAM-1) on HUVEC, and was evident at both 25 degrees C and 4 degrees C. Anti-E-selectin and anti-SLea blocked the augmented attachment, whereas anti-SLex, an antibody against another known ligand for E-selectin, did not. The collective evidence indicates that attachment between pancreas carcinoma cells and activated endothelial cells is regulated by cytokines such as IL-1 beta and TNF-alpha, and is mediated by SLea on pancreas carcinoma and E-selectin on endothelial cells. These molecules may be of significant importance in blood-borne metastasis of pancreatic carcinoma cells to inflamed sites.

Aged↗
PubMed1993

Increased IgE level as a marker of host-versus-graft disease: inhibition of this HVGD with a monoclonal antibody to IL-4.

BALB/c mice injected at birth with (BALB/c x C57BL/6)F1 hybrid spleen cells developed host versus graft disease (HVGD) with immunological features, such as various autoantibodies, immune complex nephritis, hepatosplenomegaly, and malignant lymphomas. In addition we found that the increased IgE levels correlated strongly with the histological grades or stages of the liver disease. In the sera of mice with HVGD and liver alterations, anti-smooth muscle antibodies (ASMA) and anti-nuclear antibodies (ANA) were detected. The subclass of ASMA was IgG1, whereas the subclasses of ANA were IgG1, IgG2a, and IgG2b. When the recipient BALB/c mice were injected at birth and at Day 3 in addition also with monoclonal anti-IL-4 antibody 11B11, the increase of IgE and IgG1 was markedly reduced and the liver disease was drastically prevented. These observations suggest that IL-4 plays an important role in the initiation of the immunoregulatory function or pathogenesis of the allogeneic effects and that the monoclonal anti-IL-4 antibody 11B11 prevents the immunodysfunctions and the autoimmune hepatopathy in mice with HVGD. The increased IgE level in the serum is a good marker of HVGD.

Animals↗
PubMed1993

Cytokine regulation of cell-to-cell interactions in lymphokine-activated killer cell cytotoxicity in vitro.

The permanent pancreas carcinoma cell line, PCI-24, was developed in order to analyse cytokine regulation on pancreas carcinoma and lymphokine-activated killer (LAK) cell interaction. PCI cells expressed ICAM-1 and HLA-ABC, but not HLA-DR antigens. PCI cells showed augmented ICAM-1 and HLA-ABC expression when incubated with interferon gamma (IFN gamma) and tumour necrosis factor alpha. A similar but weak augmentary effect on the HLA-ABC and ICAM-1 surface expression was seen with interleukin-1 beta treatment. Natural attachment of LAK to PCI cells was augmented by recombinant IFN gamma in close association with ICAM-1 up-regulation on PCI cells. In addition, natural attachment was significantly inhibited by anti-LFA-1 and anti-ICAM-1 antibody treatments. Cytotoxicity of the LAK cells against PCI cells was also significantly inhibited with the same treatment. Thus, the attachment of LAK cells to PCI cells through LFA-1/ICAM-1 molecules appeared to be essential for the cytotoxicity for PCI cells. Pretreatment of PCI cells, but not of LAK cells, with IFN gamma or other cytokines resulted in a decrease of susceptibility for LAK cell cytotoxicity. The decreased susceptibility inversely correlated with HLA-ABC expression on the PCI cells. The collective evidence indicates that, although LAK cell attachment to pancreas carcinoma cells through the LFA-1/ICAM-1 molecule is augmented by IFN gamma, IFN gamma treatment of pancreas carcinoma cells reduces LAK cell cytotoxicity possibly through an increase in HLA-ABC or a regulation of molecules closely associated to HLA-ABC expression.

Aged↗
PubMed1993

Susceptibility of renal tubular cells to lymphokine-activated killer (LAK) cells: application of culture system using a collagen gel matrix.

Monolayer cultures of renal tubular (hKEC) cells were established. These cells formed empty spheroids after 2-3 weeks of culture in a collagen gel matrix. A subcellular polarity from the apex to basement was induced in these "spheroidal" hKEC cells. The weak expression of laminin at the outer surface was evident on spheroidal but not on monolayered hKEC cells. The regulation of HLA-ABC, DR, and intercellular adhesion molecule-1 (ICAM-1) antigens on hKEC cells in the gel matrix was investigated utilizing digestion of gel matrix by collagenase. Enzymatic digestion of the collagen gel did not significantly affect the surface expression of HLA-ABC and ICAM-1, but reduced HLA-DR expression as shown by flow cytometry. The MHC and ICAM-1 molecules on both spheroid-forming and monolayered hKEC cells were upregulated by adding a supernatant of mixed lymphocyte reaction (MLR) and recombinant human interferon (IFN)-gamma. HLA-DR antigen expression was inconsistently induced on the hKEC cells cultured in collagen gel without MLR supernatant or IFN-gamma. In contrast, no HLA-DR expression was found on monolayered hKEC cells in the absence of MLR supernatant or IFN-gamma. Spheroid-forming hKEC cells, when dispersed by enzymatic digestion, were more susceptible to cytolysis by lymphokine-activated killer (LAK) cells than were the enzymatically dispersed, monolayered cells in the 51Cr-release assay. The LAK cells were seen to migrate into the collagen gel and kill the hKEC cells. Thus, LAK cells may function to favor the acceleration of graft rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Surface↗
PubMed1993

[Immunohistochemical study of c-erbB-2 proto-oncogene product in prostatic cancer].

The c-erbB-2 proto-oncogene product is expressed in adenocarcinomas of breast cancer and ovarian cancer, and its significance as a prognostic factor has been increasingly noted. We immunohistochemically studied the expression of c-erbB-2 proto-oncogene product using anti-c-erbB-2 gene product polyclonal antibody (Nichirei), which was produced using a synthetic peptide at the C-terminal portion as the immunogen. The subjects consisted of 52 patients with prostatic cancer who were treated at the Department of Urology, Shiga University of Medical Science, from 1982 to 1990. The expression of c-erbB-2 gene was observed in 40 of the 52 patients (76.9%). The positive rate was highest in patients with poorly differentiated cancer and in stage D2 patients, but there were no significant differences in positive rates among patients with different histological types or clinical stages. The probability that progression would occur was significantly (p < 0.05) lower in the group that tested positive for c-erbB-2 than in the group that tested negative among 33 stage D2 patients after 5 years of treatment. When cause specific survival rates were calculated using the Kaplan-Meier method, the group that tested positive had a significantly (p < 0.001) poorer outcome than the group that tested negative after 3 years and 6 months of treatment. The above results suggest that c-erbB-2 expression in prostatic cancer may be useful in predicting the prognosis of the disease.

Adenocarcinoma↗
PubMed1993

[Human prostatic tissue specific antigens: a model for the research of monoclonal antibodies against unknown antigens].

Mouse monoclonal antibodies were prepared using a cell mixture containing prostatic secretory, basal cells and stromal cells as an immunogen, and by the immunofluorescence method with cryosections of prostate tissue. An immunohistochemical screening process was used in the expectation that it would help identify not only the antibodies reacting with the secretory cells predominant in the prostate but also those reacting with relatively rare cells in the prostate tissue. Two cell clones have been established which produce antibodies (IgG1) that react well with prostatic secretory cells: a clone producing antibodies specific to prostatic acid phosphatase (PAP) and one producing antibodies specific to prostate-specific antigen (PSA). These antibodies could recognize the native antigens in the seminal plasma, respectively. These findings indicate that antibodies recognizing only one substance can be prepared, even when a mixture of prostatic tissue including many proteases is used as an immunogen. Production of antibodies against prostate-specific antigens other than PAP and PSA by this method should provide a useful means for analyzing unknown antigens in the prostate.

Acid Phosphatase↗
PubMed1993

The prognostic value of the HNK-1 (Leu-7) antigen in prostatic cancer--an immunohistochemical study.

The anti-HNK-1 (Leu-7) monoclonal antibody (MAb) was revealed to be reactive with noncancerous and cancerous prostatic epithelial cells, although this antibody was originally found to be reactive against natural killer cells. However, the prognostic significance of HNK-1 antigen in prostatic cancer patients remains unknown. The expression of HNK-1 antigen on prostatic cancer was investigated immunohistochemically using the avidin-biotin-peroxidase complex (ABC) method with the anti-HNK-1 monoclonal antibody. Of the 52 patients with prostatic cancer, 49 patients (94%) showed reactivity to anti-HNK-1 MAb and the immunoreaction was associated with the histological differentiation of prostatic cancer. Well differentiated cancer showed the highest percentage of positively stained cancer cells and poorly differentiated cancer showed the lowest percentage. No statistically significant differences existed between groups classified by stage, although the more advanced cancers tended to have weaker reactions. The five-year survival rate and interval free of progression were then studied using the Kaplan-Meier method on 33 patients with stage D2 disease who had received endocrine therapy. The findings indicated that a high survival rate and a longer interval free of progression were associated with a higher fraction of positively stained cancer cells. In conclusion, the expression of HNK-1 antigen on prostatic cancer may be a useful prognostic factor in patients with prostatic cancer.

Adult↗
PubMed1992

A rat model of human T lymphocyte virus type I (HTLV-I) infection. 1. Humoral antibody response, provirus integration, and HTLV-I-associated myelopathy/tropical spastic paraparesis-like myelopathy in seronegative HTLV-I carrier rats.

Human T lymphocyte virus type I (HTLV-I) can be transmitted into several inbred strains of newborn and adult rats by inoculating newly established HTLV-I-immortalized rat T cell lines or the human T cell line MT-2. The transmission efficiency exceeds 80%, regardless of strain differences or the age at transmission. The production of anti-HTLV-I antibodies significantly differs among the strains and depends on the age at the time of transmission. Rats neonatally inoculated with HTLV-I-positive rat or human cells generally become seronegative HTLV-I carriers throughout their lives, whereas adult rats inoculated with HTLV-I-positive cells at 16 wk of age become seropositive HTLV-I carriers. The HTLV-I provirus genome is present in almost all organs, regardless of whether the carriers are seronegative or seropositive. According to antibody titers to HTLV-I, there are three groups of inbred rat strains: ACI, F344, and SDJ (high responders); WKA, BUF, and LEJ (intermediate responders); and LEW (low responder). Three of three 16-mo-old seronegative HTLV-I carrier rats of the WKA strain developed spastic paraparesis of the hind legs. Neuropathological examinations revealed that the lesions were confined primarily to the lateral and anterior funiculi of the spinal cord. Both myelin and axons were extensively damaged in a symmetrical fashion, and infiltration with massive foamy macrophages was evident. The most severe lesions were at levels of the thoracic cord and continued from the cervical to the lumbar area. These histopathological features as well as clinical symptoms largely parallel findings in humans with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). These HTLV-I carrier rats, in particular the WKA rats described above, can serve as a useful animal model for investigating virus-host interactions in the etiopathogenesis of HTLV-I-related immunological diseases, particularly HAM/TSP.

Aging↗