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Biomedical subjects

S Imamura

Publications and source records attributed to S Imamura.

601 records · Page 34Linked to original sources
PubMedDate not supplied

[Cell mediated immune response in leprosy lesions].

Five biopsies from 2 leprosy patients, tuberculoid (TT), and polar lepromatous (LLp), were studies using immunoperoxidase procedures with monoclonal antibodies. Immunohistochemical patterns of them were remarkably different. In a TT patient, epithelioid cells and helper/inducer T (Leu 3a+) cells made the central core of a granuloma surrounded by suppressor/cytotoxic T (T8+) cells and B cells, indicating a possible immune-mediated cell response. The distribution of B cells suggests that not only T but also B cells may take part in the formation of the granuloma. In contrast, helper/inducer cells, suppressor/cytotoxic cells, and macrophages of a LLp patient were admixed uniformly at the site of the lesion, indicating a poor immune response. Although the ENL skin lesion of this LLp patient did not eliminate the bacilli, HLA-DR expression by keratinocytes and increased numbers of helper/inducer cells found in an ENL lesion, comparable to the findings of TT leprosy, suggests that a cell mediated immune response may play some role in the pathogenesis of ENL reaction.

Aged↗
PubMedDate not supplied

A novel Philadelphia chromosome-positive cell line with multipotential properties.

A novel Philadelphia chromosome-positive cell line was established from the peripheral blood of a patient with chronic myelogenous leukemia in megakaryoblastic crisis. This cell line, designated TN922 showed the positive phenotypes for myeloid, monocyte-macrophage, erythroid and megakaryocytic markers. The stimulation with phorbol 12-myristate 13-acetate (PMA) increased the expression of megakaryocytic markers including the platelet peroxidase activity, dimethylsulfoxide or transforming growth factor-beta promoted up-regulation of the erythroid markers. Stimulation with PMA, tumor necrosis factor-alpha or interleukin-6 also brought about the expression of monocytoid markers. These findings indicated that TN922 cell line has the property of acting as multipotential progenitor cells. TN922 cells showed gradual growth in the absence of growth factors but the addition of granulocyte/macrophage colony-stimulating factor (GM-CSF) promoted cell growth. The message of GM-CSF was detected in TN922 cells and the neutralizing antibody against GM-CSF receptor alpha-subunit suppressed cell growth. These results indicated that TN922 cell line proliferates in an autocrine secretion of GM-CSF.

Aged↗
PubMedDate not supplied

Multidrug resistance due to impaired DNA cleavage in a VP-16-resistant human leukemia cell line.

We established a VP-16-resistant line of human leukemia cells, K562/VP-H2, derived from K562 cells. K562/VP-H2 cells were 44-fold more resistant to VP-16 than were K562 cells. K562/VP-H2 cells were also resistant to doxorubicin, daunorubicin and mitoxantrone, but showed little or no resistance to vincristine, aclarubicin, idarubicin, idarubicinol, cytosine arabinoside, cis-platinum or camptothecin. K562/VP-H2 cells did not over-express P-glycoprotein or multidrug resistance protein, and showed intracellular accumulation of VP-16 similar to that in K562 cells. While the expressions of topoisomerase II-alpha gene and topoisomerase II-beta gene, or catalytic activity in nuclear extract of K562/VP-H2 cells were similar to that of K562 cells, the VP-16 induced DNA cleavage was reduced in K562/VP-H2 cells compared to K562 cells, suggesting that the reduction of topoisomerase II-mediated DNA cleavage through qualitative alteration of topoisomerase II may be the main mechanism of acquired multidrug resistance for K562/VP-H2 cells. The K562/VP-H2 cell line is an interesting model for studying resistance to antileukemia drugs targeting topoisomerase II.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

Lipoatrophic lesions preceded by pain and erythema - a new clinical entity?

A 46-year-old female patient presented with deeply depressed lesions on the abdominal wall after slight pain and erythema, without a history of trauma or injection. No general symptoms were noted. There was a marked decrease of subcutaneous fatty tissue with minimal inflammatory cell infiltration. We found three similar cases in the literature. Differential diagnoses were performed, but our case and the other three cases do not fit any of the heretofore described lipoatrophic diseases, and might be a new clinical entity.

Abdominal Muscles↗
PubMedDate not supplied

Cerebral angiography and ultrasonic quantitative flow measurement of common carotid artery in patients with cerebral infarction.

Blood flow rate and velocity in the common carotid artery were measured with an ultrasonic quantitative flow measurement (QFM) system and cerebral angiography was performed in 98 patients about four weeks after the onset of cerebral infarction. Angiography revealed complete occlusion in 13 patients (CO group), visible stenosis in 45 patients (S group), and no apparent stenosis in 40 patients (N group). In the CO group, damaged-side blood flow (DF; 4.80 ml/sec) and velocity (DV; 10.5 cm/sec) were significantly lower (P less than 0.01) than intact-side blood flow (7.19 ml/sec) and velocity (14.86 cm/sec). Both DF and DV were significantly lower in group CO than group S (7.55 ml/sec and 15.04 cm/sec) and in group S than group N (9.32 ml/sec and 18.07 cm/sec). Degree of stenosis in the internal carotid and middle cerebral arteries was significantly associated with reduced DF (P less than 0.05). Of the 24 patients with a mean DF of under 6.5 ml/sec, 15 had stenosis of 75% or more; of the 74 patients with a mean DF of 6.5 ml/sec or more, 66 had stenosis of less than 25%. The results indicate that blood flow determined by QFM reflects the degree of occlusion or stenosis in the intracranial trunk arteries and may thus provide a practical, noninvasive method of assessing the severity of cerebrovascular lesions.

Acute Disease↗
PubMedDate not supplied

Induction of neonatal immunologic tolerance to heart transplantation by intrathymic myocardial cell inoculation in rats.

To induce immunologic tolerance, intrathymic inoculation of myocardial cells in rats was performed during the neonatal period. Isolated myocardial cells from Wistar-Lewis (LEW/Crj) rat hearts were inoculated into the thymi of incompatible neonatal Wistar-King (WKAH/HKm) rats without use of immunosuppressants. Ten weeks later the heart from the LEW donor was transplanted heterotropically to the pretreated male WKAH rat (group 1, n = 14). As controls (groups 2 through 4), heart transplantation was performed in each of 10-week-old rats as follows: (1) The syngeneic heart was transplanted (group 2, n = 4); (2) the allogeneic heart was transplanted without use of immunosuppressants (group 2, n = 12); and (3) the allogeneic heart was transplanted with use of immunosuppressants (cyclosporine, 20 mg/kg/day, for 10 days after transplantation, (group 4, n = 5). In groups 1 through 3, four rats with heart transplants in each group were killed on the seventh day after transplantation and were histopathologically examined. No early rejection was seen in group 1. Hematoxylin-eosin staining of the thymus from the inoculated recipient revealed that donor myocardial cells continued to survive in the thymic tissue. The remaining rats in groups 1, 3, and 4 were saved for study of graft survival time. The longest proven graft survival in group 1 was 390 days, whereas it was only 7 days in group 3. These results indicated that intrathymic inoculation of donor myocardial cells in rats into incompatible neonatal recipients induced donor-specific tolerance for subsequent heart transplantation.

Animals↗