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Biomedical subjects

A Kasuga

Publications and source records attributed to A Kasuga.

46 records · Page 3Linked to original sources
PubMed1993

The role of cytotoxic macrophages in non-obese diabetic mice: cytotoxicity against murine mastocytoma and beta-cell lines.

The cytotoxicity of macrophages from non-obese diabetic (NOD) mice against murine mastocytoma (P-815), and murine beta-cell lines having the NOD gene background (MIN6N-9a), were examined. Peritoneal exudate cells from 20-week-old mice showed higher cytotoxicity, measured as inhibition of thymidine uptake into P-815, than those from 12-week-old mice (p < 0.01). In cyclophosphamide-injected mice, cytotoxicity of peritoneal exudate cells had increased at 8 days post-injection, at which time the mice were not diabetic. To confirm macrophage cytotoxicity against pancreatic cells and examine its cytolytic mechanism, the cytotoxicity of peritoneal exudate cells from cyclophosphamide-injected NOD mice against MIN6N-9a cells was measured by the chromium release assay. These peritoneal exudate cells showed higher cytotoxicity as compared to those of saline-injected mice (p < 0.001). Macrophages were demonstrated to be the major component of peritoneal exudate cells (50%) by flowcytometric analyses. Cytotoxicity increased with macrophage enrichment by adhesion (p < 0.01). Furthermore, a macrophage toxin, silica, completely blocked the cytotoxicity (p < 0.001). Cytokines (interleukin 1 and tumour necrosis factor) and a nitric-oxide-producing vasodilator, sodium nitroprusside, were cytotoxic to MIN6N-9a cells but only sodium nitroprusside showed cytotoxicity when incubated for the same period as peritoneal exudate cells. Thus, macrophages play an important role in beta-cell destruction and soluble factors other than cytokines (e.g. nitric oxide) may be mediators of this early cytolytic process.

Aging↗
PubMed1993

Detection of heat shock protein in patients with insulin-dependent diabetes mellitus.

We have investigated whether antibodies to heat shock protein (hsp) 65 are present in sera from patients with insulin-dependent diabetes mellitus by using Mycobacterium leprae hsp65. Fifty-two sera from patients with IDDM, 36 from patients with unclassified insulin-treated diabetes mellitus and 41 from normal healthy controls were examined by ELISA assay. Seventeen (32.7%) out of 52 IDDM sera and 10 (27.8%) out of unclassified insulin-treated diabetic sera were positive for anti-Mycobacterium (anti-M. leprae) hsp65 antibodies while none of the healthy control sera were positive. Based on western blot analysis, 12 of the 17 IDDM sera and 1 of 2 sera from the unclassified insulin-treated diabetics were positive for anti-M.leprae hsp65 antibodies while all normal control sera were negative. These results support the idea that hsp65 may play a role in the pathogenesis of IDDM. Future studies are necessary to elucidate the role of hsp65 in the pathogenesis of IDDM.

Antibodies, Bacterial↗
PubMed1993

A case of aldosterone producing adenoma associated with high PRA after long-term angiotensin converting enzyme inhibitor treatment.

A 62-year-old patient with non-insulin dependent diabetes (NIDDM) was admitted to our hospital for blood pressure control. He had been treated with angiotensin converting enzyme inhibitor (ACEI) for 7 years and showed marked hypokalemia with increased urinary potassium excretion. Hormonal examination revealed a normal plasma aldosterone concentration and increased plasma renin activity (PRA, 13.4 ng/ml/h), so potassium losing nephropathy was suspected. After discontinuation of the ACEI, PRA decreased to normal. An adrenal adenoma was found on abdominal magnetic resonance imaging (MRI) and adrenalectomy was performed to confirm aldosterone producing adenoma (APA). Although ACEIs are said not to alter PRA in APA, this drug was primarily responsible for the increased PRA in this case. This is a rare case of APA, which showed markedly increased PRA during ACEI treatment.

Adenoma↗
PubMed1991

The suppressive effect of anti-asialo GM1 antibody on low-dose streptozotocin-induced diabetes in CD-1 mice.

To elucidate the role of natural killer (NK) cells in the pathogenesis of diabetes in streptozotocin-induced diabetes, we examined whether treatment with anti-asialo GM1 antibody prevents the occurrence of diabetes in CD-1 mouse model. Anti-asialo GM1 antibody was injected intraperitoneally 2-3 times a week starting three days before the first streptozotocin injection. In controls, rabbit immunoglobulin or saline was injected instead of anti-asialo GM1 antibody. Three of twelve anti-asialo GM1 antibody-treated mice developed diabetes, however eight of eight (100%) rabbit immunoglobulin injected mice and 20 of 23 saline-injected mice developed diabetes. The incidence of diabetes in the anti-asialo GM1 antibody-injected group was significantly higher than in the two control groups (p less than 0.01, p less than 0.01, respectively). The NK-cell activities of spleen cells from anti-asialo GM1 antibody-treated mice were significantly lower than in control mice. Flow-cytometry analysis demonstrated that anti-asialo GM1 antibody-positive cells had disappeared from spleens of anti-asialo GM1 antibody-injected mice but no suppression of T-lymphocytes could be demonstrated. These results suggest that NK cells play a role in the pathogenesis of streptozotocin-induced diabetes in CD-1 mice.

Animals↗
PubMed1991

Anti-asialo GM1 antibody suppression of cyclophosphamide-induced diabetes in NOD mice.

To elucidate the role of natural killer (NK) cells in the pathogenesis of diabetes in the non-obese diabetic (NOD) mouse, we examined whether or not cyclophosphamide-induced diabetes occurs in NOD mice intraperitoneally (i.p.) injected with anti-asialo GM1 antibody. Two weeks after a single intraperitoneal injection of cyclophosphamide, none of the 24 NOD mice which had previously been treated with antiasialo GM1 antibody, 2-3 times per week for either 2 or 3 weeks, had developed indications of diabetes such as glycosuria or a high plasma glucose level. On the other hand, signs of diabetes were found in 10 of 24 control NOD mice injected with normal rabbit Ig instead of anti-asialo GM1 antibody (p less than 0.01). The NK cell activities of spleen cells from anti-asialo GM1 antibody-treated mice were significantly lower than those of control mice (p less than 0.01). Flowcytometry analysis demonstrated that anti-asialo GM1 antibody-positive cells had disappeared from the spleens of anti-asialo GM1 antibody-injected mice but no suppression of CD8+ and CD4+ cells could be demonstrated. These observations suggest that NK cells are involved in the development of diabetes in NOD mice.

Animals↗
PubMed1989

Spontaneous rupture of the quadriceps tendon in patients on maintenance hemodialysis--report of three cases with clinicopathological observations.

Three patients receiving maintenance hemodialysis therapy for end-stage renal failure presented with spontaneous rupture of the quadriceps tendon(s). Biochemical data and the skeletal roentgenograms were compatible with secondary hyperparathyroidism. Histological examination of the excised quadriceps tendon specimens suggested that repeated minor avulsion fractures of the bone cortex at the tendon insertion site had preceded the final total tendon rupture and that osteitis fibrosa was responsible for these minor fractures. Serum alkaline phosphatase level had been increasing continuously for approximately five years prior to the tendon rupture in all three patients, indicating that uncontrolled osteitis fibrosa due to secondary hyperparathyroidism over these years preceded the tendon rupture.

Adult↗
PubMed1986

Spontaneous hepatocellular carcinomas in lungfish.

Liver tumors were observed in 2 South American lungfish (Lepidosiren paradoxa) and in 1 African lungfish (Protopterus amphibius) kept in 3 different aquariums in Japan for 2-5 years. In the first case a single, large nodule (70 X 60 X 55 mm) in the liver had been noted externally as a swelling 1 year prior to death. In the second case 2 rounded nodules (25 X 15 X 15 mm and 15 X 10 X 10 mm) were incidentally found at autopsy. In the third case, which also demonstrated abdominal swelling for 1 year preceding death, 2 green nodules (50 X 50 X 40 mm and 17 X 17 X 17 mm) were found in the liver together with multiple metastatic lesions. Histologically, variation was evident from tumor to tumor, even within the same animal. The most common histologic type was typical trabecular hepatomas. Admixtures of glandular or papillary structures were noted in some tumors. A region of poorly differentiated hepatocellular carcinoma with spindle-shaped cells in a sheetlike arrangement was noted in one case. The cause of these tumors is unknown. Since liver tumors were discovered at relatively high incidence (3/14 autopsied cases, including 6 species), lungfish seem to be predisposed to the development of liver tumors.

Animals↗