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Biomedical subjects

S Imamura

Publications and source records attributed to S Imamura.

At least 343 records · Page 19Linked to original sources
PubMed1989

Immunological effects of in vitro hyperthermia.

The effect of in vitro hyperthermia treatment on the immunological function of human peripheral blood mononuclear cells (PBMC) was investigated to evaluate the immunosuppressive effect of hyperthermia, which has been successfully used for the treatment of cancer. The viability was slightly reduced after the treatment in a temperature dependent manner, however, it was statistically insignificant. Both natural killer (NK) activity and phytohaemagglutinin (PHA)-induced blastogenesis were temperature-dependently reduced after the treatment. After the treatment at 44 degrees C, NK activity was only 4.3% and no PHA-induced blastogenesis was observed. The reduced NK activity after the treatment may be in part due to a decreased number of subpopulations of highly active NK cells. Leu 7-1, 11+ cells and Leu 7+, 11+ cells. Therefore, the possibility of hyperthermia-induced inhibition of the host immune system must be considered when we use hyperthermia clinically for cancer treatment.

Cell Survival↗
PubMed1989

Demonstration of clonal proliferation of T lymphocytes in early neoplastic disease. Studies with probes for the beta-chain of the T cell receptor and human T cell lymphotropic virus type I.

This study demonstrates that the detection of rearrangement of the T-cell receptor gene and adult T cell leukemia virus or human T cell lymphotropic virus type I (ATLV/HTLV-I) integration in the genome are sensitive and practical methods for the diagnosis and characterization of cutaneous T cell neoplasms. Biopsy specimens obtained from small skin nodules containing a dense infiltration of lymphocytes were analyzed by Southern blotting with the use of probes for both the beta-chain of the T-cell receptor gene and the ATLV/HTLV-I genome. DNA samples from one patient with early, chronic adult T cell lymphoma or leukemia, revealed the monoclonal proliferation of lymphocytes. For another patient with early cutaneous T cell lymphoma analysis by Southern blotting with the beta-chain probe of DNA from three separate lesions revealed identical rearranged bands, indicating not only the monoclonal proliferation of T cells in each lesion but also the clonal origin of each lesion. In contrast, analysis by Southern blotting of DNA samples extracted from three nodules from a patient with lymphomatoid papulosis showed no rearranged band and therefore no clonal proliferation. DNA extracted from blood lymphocytes of these patients failed to hybridize with the probes described above as a rearranged band. These results indicate that analysis of DNA extracted from skin lesions may have diagnostic value in determining monoclonal proliferation of lymphocytes in patients with early stage cutaneous lymphomas.

Adult↗
PubMed1989

Familial occurrence of anomalous pancreaticobiliary duct union associated with gallbladder neoplasms.

The authors present two cases of anomalous pancreaticobiliary duct union that occurred in a mother and her daughter; the former was associated with gallbladder adenocarcinoma, and the latter, gallbladder adenoma with high grade dysplasia. This disorder has been considered a developmental anomaly, although the true etiology has not been known. This is the first report of familial occurrence of this anomaly, and it may point to the presence of a genetic factor in its development. Another implication is the presence of histological features which suggest the possible sequence of anomalous pancreaticobiliary duct union to intestinal metaplasia to adenoma or dysplasia to cancer of the gallbladder.

Adenocarcinoma↗
PubMed1988

Cutaneous-type adult T-cell leukemia/lymphoma. A unique clinical feature with monoclonal T-cell proliferation detected by Southern blot analysis.

A 60-year-old woman suffered from multiple subcutaneous nodules with a self-limited clinical course. High titer of the antibody against the adult T-cell leukemia/lymphoma (ATL)-associated cell antigen was detected and atypical lymphocytes were present in less than 1% of the peripheral leukocytes. Tumor cells were identified by the molecular biology technique Southern blot analysis, which showed monoclonal cell expansion of the helper/inducer T cells integrated with human T-cell lymphotropic virus type I/adult T-cell leukemia virus. This patient was diagnosed as having the cutaneous type of smoldering ATL in a very early stage. In this case, only gene analysis of the skin lesion could facilitate making an early differential diagnosis of ATL from other lymphoproliferative diseases, including nonviral cutaneous T-cell lymphoma and benign lymphoid hyperplasia.

Antibodies, Monoclonal↗
PubMed1988

Relationship between macrophage infiltration and epidermopoiesis in delayed-type hypersensitivity.

The relationship between epidermopoiesis and macrophage infiltration was studied in delayed-type hypersensitivity (DTH) skin lesions in guinea pigs that had been sensitized with heat-killed tubercle bacilli or bovine serum albumin (BSA). Macrophages were identified with acid-phosphatase and nonspecific esterase stains, and the epidermal proliferative response was studied at DTH challenge sites by autoradiography. The number of macrophages in the sensitized animals was higher than that in the nonsensitized animals 48-72 h following challenge injections, when labelling indices were also elevated in the former group. Soluble factor(s) from cultured macrophages transiently enhanced the DNA synthesis of epidermal cells in cultures and in the sites injected with the factor(s). These results suggest that macrophages retained in the DTH lesion may play a role in an acceleration of epidermal proliferation, thus leading to acanthosis and lichenification.

Animals↗
PubMed1988

Calpain activates two transglutaminases from porcine skin.

Two transglutaminases (TGase) with estimated molecular weight of 55,000 (55-K TGase) and 120,000 (120-K TGase) were partially purified from the cytosolic fraction of porcine skin (epidermis-rich preparation) using DEAE-cellulose and gel-filtration chromatographies. The enzyme activities of both transglutaminases were enhanced more than 20-fold by treatment with calpain (Ca2+-dependent cysteine proteinase) in the presence of Ca2+, and this enhancement was inhibited by adding EDTA, leupeptin, or an endogenous calpain-specific inhibitor protein (calpastatin). 55-K TGase was effectively activated by a smaller amount of calpain than was 120-K TGAse, while known activating reagents such as thrombin and dimethyl sulfoxide or heat treatment preferentially activated 120-K TGase. One of the physiological functions of calpain in the epidermis may be the activation of epidermal transglutaminases.

Animals↗
PubMed1988

Antithrombotic treatment in livedo vasculitis.

Two patients with livedo vasculitis were treated successfully with antiplatelet drugs including ticlopidine hydrochloride, dipyridamole, and low-dose aspirin. Increased platelet functions were restored 1 week after the beginning of the treatment, followed by dramatic improvement of painful leg ulcers within 1 month. Livedo status was unchanged. We claim that antiplatelet therapy should be the first choice of treatment in this disease.

Adult↗
PubMed1988

Letterer-Siwe disease: immunopathologic study with a new monoclonal antibody.

Three cases of Letterer-Siwe disease were studied with the monoclonal antibody Lag, which reacts to the antigen on the membranes of Birbeck granules and related structures of human Langerhans cells. Both lymph nodes and lesional skin contained abundant Lag-positive cells. By two-dimensional gel electrophoresis, antigenic substances in the lymph nodes of patients with Letterer-Siwe disease were found to have the same molecular weight of 40,000 dalton and isoelectric points extending from 4.7 to 6.5 as those in normal human skin and lymph nodes. Our results support the contention that Letterer-Siwe disease is a proliferative disorder of Langerhans cells. A double-staining method with Lag and anti-T6 antibody revealed that Lag reacted to 70% of T6-positive cells in the lymph nodes but to almost all such cells in skin lesions of patients with Letterer-Siwe disease, suggesting that the proliferating cells consist of at least Lag+, T6+, and Lag-, T6+ subpopulations.

Antibodies, Monoclonal↗
PubMed1988

Effects of substance P and substance K on the growth of cultured keratinocytes.

The effects of substance P and substance K, which are coexpressed in the same mRNA as a beta-preprotachykinin in peripheral tissues and released in the inflammatory lesion of the skin, were examined on epidermal proliferation using spontaneously transformed mouse epidermal cell line (Pam 212 cells). Substance P stimulated the synthesis of DNA of Pam 212 cells in the medium containing 2%-10% fetal calf serum (FCS). Stimulation of DNA synthesis was dose dependent if the cells were cultured in the medium containing 2% FCS (quiescent condition). This effect was inhibited by spantide. In a serum-free medium, substance P had no effect on keratinocyte proliferation. In contrast, substance K, which shares a common amino acid sequence with substance P on its C-terminal, did not affect DNA synthesis of Pam 212 cells in either medium condition. Substance P released in inflammation may stimulate epidermal proliferation.

Animals↗
PubMed1988

Purification and characterization of calpains from pig epidermis and their action on epidermal keratin.

Two forms of Ca++-dependent cysteine proteinases, calpain I, requiring low Ca++ (microM concentration), and calpain II, requiring high Ca++ (mM concentration), were purified from the cytosolic fraction of pig epidermis. Calpains I and II were separated on DEAE-cellulose chromatography, and thereafter they were purified by separate but almost identical procedures, which included chromatographies on Sephacryl S-300, Blue Sepharose CL-6B, and DEAE Bio-Gel A. Purified calpains I and II required 10 and 450 microM Ca++ for half-maximal activation, respectively, and had an optimal pH of 7.0 to 8.0. Both enzymes were heterodimers and composed of one heavy subunit (83 kDa for calpain I and 80 kDa for calpain II) and one light subunit (29 kDa for both enzymes). The action of calpains I and II on keratin extracted from the same tissue was studied. Both enzymes rapidly cleaved keratin into small fragments. The cleavage depends on Ca++ and could be blocked by leupeptin and calpastation, an endogenous calpain-specific inhibitor, which was also found in the cytosolic fraction of pig epidermis and partially purified.

Animals↗