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Biomedical subjects

Z Ota

Publications and source records attributed to Z Ota.

At least 55 records · Page 3Linked to original sources
PubMed1995

Escape of red blood cells through gaps in glomerular basement membrane in a patient with mixed connective tissue disease.

Hematuria in patients with glomerulonephritis seems to result from the passage of red blood cells through anatomical gaps in the glomerular basement membrane. However, such morphological evidence has rarely been demonstrated. A patient with mixed connective tissue disease associated with membranous glomerulonephritis is described in whom the renal biopsy specimen showed an escape of red blood cells through a gap in the basement membrane. These findings support the morphological basis of hematuria in glomerulonephritis.

Adult↗
PubMed1995

Minimal-change nephrotic syndrome associated with systemic lupus erythematosus.

A case of systemic lupus erythematosus (SLE) associated with minimal-change nephrotic syndrome (MCNS) is described. A 41-year-old woman with SLE presented with symptoms of nephrotic syndrome. Renal biopsy revealed minor glomerular abnormalities without the deposition of immune complexes. The initial heavy proteinuria promptly decreased after the prednisolone dosage was increased and disappeared 4 weeks later. The patient had a relapse of nephrotic syndrome without exacerbation of immunoserological reactions when the prednisolone dose was subsequently decreased. Remission was achieved 5 days after methylprednisolone pulse therapy. T cell dysfunction, which is present both in SLE and MCNS, might have triggered MCNS during the course of SLE.

Adult↗
PubMed1995

Apoptosis in thyroid diseases: a histochemical study.

Recent studies demonstrate that apoptosis is an important process in physiological and pathological cell death. We examined the apoptotic phenomena in thyroid tissues by two methods: immunohistological and in situ end-labeling of fragmented DNA (ISEL). In thyroid tissues from patients with Hashimoto's thyroiditis and thyroid cancer, fragmented nuclear DNA and LeY (apoptosis associated antigen) were observed. In tissues from patients with Graves' disease, LeY and bcl-2 oncoprotein were expressed, but no ISEL positive cells were observed. In contrast, thyrocytes in normal thyroid tissues were not stained with ISEL or anti-LeY antibodies (Abs). Fas antigen (Ag) was expressed in various thyroid tissues, including normal subjects. The clinical meaning of this was not determined. These results suggest that the apoptotic process takes place in Hashimoto's thyroiditis and thyroid cancer, and is overcome in Graves' disease by bcl-2 expression.

Apoptosis↗
PubMed1995

Effect of vasopressin V1- and V2-receptor stimulation on blood pressure in DOCA-salt hypertensive rats.

We recently reported that stimulation of the arginine vasopressin (AVP) V1-receptor enhanced the pressor response in spontaneously hypertensive rats (SHR). In the present study, we investigated acute changes in systolic blood pressure (SBP) and heart rate (HR) after intravenous injections of AVP, OPC-21268 (a V1-receptor antagonist), and OPC-31260 (a V2-receptor antagonist), in anesthetized DOCA-salt hypertensive rats (DOCA) and age-matched sham-operated Wistar rats (control) to determine whether the pressor effect is specific to SHR or is present in other hypertensive animal models. SBP increased significantly in DOCA rats 9 min after injection of AVP 5 ng/kg without a concomitant increase in HR. Neither OPC-21268 3mg/kg nor OPC-31260 3mg/kg caused significant changes in SBP or HR. SBP tended to increase when AVP was administered after injection of OPC-31260. HR increased significantly 15 min after the combined treatment with OPC-31260 and AVP in DOCA rats compared with control rats. SBP did not change significantly when AVP was administered after injection of OPC-21268 in DOCA or control rats, but HR decreased significantly from 1 to 4 min after injection of AVP in DOCA rats. Our results suggest that V1-receptor stimulation does not enhance the pressor response in the DOCA rat, which is a model of volume-dependent hypertension, suggesting that the AVP system, especially V1-receptor, is not as important in the development or maintenance of hypertension in DOCA rats as in SHR.

Animals↗
PubMed1995

ICRF-193 modifies etoposide-induced apoptosis in thymocytes.

Etoposide (VP-16), one of the topoisomerase II (TopoII) inhibitors, interferes with TopoII by inducing the formation of and stabilizing a cleavable enzyme-DNA complex. VP-16 has been demonstrated to induce apoptosis in murine thymocytes. To clarify the mechanism of action of VP-16, we examined the in vitro effect of a non-cleavable-complex-forming type TopoII inhibitor, ICRF-193 which inhibits the DNA strand breakage induced by VP-16, on murine thymocytes in which apoptosis had been induced with VP-16. DNA fragmentation is characteristic of apoptosis. In the early stages, ICRF-193 decreased DNA fragmentation induced by VP-16, although this inhibitory effect decreased in the later. These data suggest that TopoII inhibitors induce apoptosis in murine thymocytes in two ways: with DNA-strand breaks in the early stage or without them. ICRF-193 itself induced apoptosis in murine thymocytes. The time course of DNA fragmentation caused by ICRF-193 was different from that of VP-16.

Animals↗
PubMed1995

Diuretic effect of cilazapril and dopamine system in the spontaneously hypertensive rat.

To assess the role of the kidney dopamine system on the diuretic state induced by angiotensin-converting enzyme (ACE) inhibitors, we examined the changes in urinary excretion and plasma level of dopamine, and kidney dopamine receptors in spontaneously hypertensive rats (SHR) treated with cilazapril, an ACE inhibitor. We administered cilazapril 10 mg/kg orally to 13-week-old SHR daily for 21 days (CILAZA group). Systolic blood pressure was significantly decreased in the CILAZA group on Day 6 compared with that in vehicle-treated SHR (control group). The urine volume was three- to fivefold higher in the CILAZA group, and total urinary dopamine secretion was also increased compared with the control group. There was no significant difference in affinity and number of kidney dopamine receptors between the CILAZA and the control groups. In conclusion, the diuretic effect caused by cilazapril is partly mediated by inhibition of the water reabsorption via the increase of dopamine production in the kidney.

Administration, Oral↗
PubMed1995

Enhanced pressor response in spontaneously hypertensive rats induced by stimulation of vasopressin-V1 receptors.

To elucidate the effect of the arginine vasopressin (AVP) system in vivo, especially V1 and V2 activity, on blood pressure, we measured the acute changes in blood pressure and heart rate after AVP, OPC-21,268 (a V1 receptor antagonist), and OPC-31,260 (a V2 receptor antagonist) were injected intravenously in anesthetized spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at the age of 15 weeks. Compared with the control period, single injection of AVP 5 ng/kg significantly increased systolic blood pressure in WKY rats without a concomitant increase in heart rate, but there was no significant increase in blood pressure in SHR. In contrast, single injection of either OPC-21,268 3 mg/kg or OPC-31,260 3 mg/kg did not affect blood pressure or heart rate in either SHR or WKY rats. Injection of AVP after the administration of OPC-31,260 induced a greater increase in blood pressure in SHR than in WKY rats, whereas injection of AVP after the administration of OPC-21,268 did not induce any clear increase in blood pressure in SHR or WKY rats. These results suggest that SHR have enhanced pressor activity mediated by V1 receptors and that this increase may be due to an increase in their number. In conclusion, enhancement of V1 activity may contribute to the development of high blood pressure in SHR.

Animals↗
PubMed1995

Crohn's disease associated with growth hormone secretory dysfunction.

A 10-year-old boy presented in 1989 with repeated episodes of vomiting, abdominal distension and severe growth retardation. Endocrinologic examination indicated growth hormone (GH) secretory dysfunction. Administration of recombinant human GH (rhGH) led to growth, but the patient discontinued treatment. He was readmitted to our hospital in 1993, at the age of 16. His stature was very short. Laboratory findings suggested malnutrition. Radiologic examination revealed regional stenosis and a cobblestone appearance of the intestine. The histologic diagnosis was compatible with Crohn's disease. Administration of prednisolone alleviated gastrointestinal symptoms with the improvement of GH secretory function.

Child↗
PubMed1995

Thrombotic thrombocytopenic purpura and myoglobinuric acute renal failure following radiation therapy in a patient with polymyositis and cervical cancer.

A 73-year-old woman was admitted to receive radiation treatment for uterine cervical cancer, however a complex series of events ensued, leading to death. She developed an acute exacerbation of polymyositis complicated by thrombotic thrombocytopenic purpura, rhabdomyolysis and acute renal failure. Radiation therapy may have produced an immune disturbance leading to the acute exacerbation of polymyositis. Auto-immune-mediated endothelial damage might have triggered a series of events leading to thrombotic thrombocytopenic purpura. Rhabdomyolysis seemed to be the main cause of acute renal failure.

Acute Kidney Injury↗
PubMed1995

Transition of morphologic features in lupus nephritis: does steroid therapy accelerate glomerulosclerosis?

We retrospectively evaluated the morphologic change of 28 follow up biopsies from 24 cases of lupus nephritis according to the classification of the World Health Organization and determined the activity index (AI) and the chronicity index (CI). In the cases with biopsies repeated within 6 months, the AI decreased significantly from 6.7 +/- 1.3 to 3.5 +/- 0.8, while the CI showed no significant change. In cases which were rebiopsied after longer intervals, AI increased significantly from 3.2 +/- 0.7 to 7.5 +/- 1.2; the CI did not change significantly. When AI and CI changes in the cases biopsied again beyond 6 months were compared with respect to therapy, AI showed no significant difference in the methylprednisolone pulse therapy group but was significantly increased in the oral steroid therapy group. The CI tended to be increased in both groups, but not significantly. Steroid pulse therapy was effective in improving active lesions with a high AI. Steroid therapy for lupus nephritis prevented short-term progression of glomerulosclerosis and did not accelerate glomerulosclerosis.

Biopsy↗
PubMed1995

[Activation of complement during hemodialysis].

In hemodialysis using 3 types of dialysis membrane materials [regenerated cellulose (RC), cellulose triacetate (CTA), and polysulfone (PS)], activation of the complement, reduction of white blood cells, and variation of vitronectin (VN) were observed. RC membrane caused a significant reduction of white blood cells and elevations of Bb and soluble membrane attack complex (S-MAC), indicating a strong activation of the alternative complement pathway. Especially, the increase of S-MAC persisted for a long time during hemodialysis. Because reduction of VN was transient, it was assumed that the S-MAC escaping removal by VN receptors might have persisted in the circulation. These findings suggested that S-MAC would become useful as an index for evaluating biocompatibility of various artificial organs including dialysis membranes.

Aged↗
PubMed1995

Developmental change of kidney dopamine receptors in spontaneously hypertensive rats.

To elucidate the role of the kidney dopamine system on blood pressure regulation, we investigated the developmental change of kidney dopamine receptors in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. The autoradiogram of [3H]-SCH23390, a specific DA1 receptor antagonist, showed that DA1 receptors were localized mainly in the rat renal cortex. The radiolabeled receptor assay (RRA) of [3H]-spiperone was performed on 3-, 7-, and 18-week-old SHR using the homogenate of renal cortex. Neither dissociation constant (Kd) nor maximum binding capacity (Bmax) were different between SHR and WKY rats at the age of 3 and 7 weeks. Nevertheless, Kd and Bmax were significantly low in 18-week-old SHR. The systolic blood pressure of 7-, and 18-week-old SHR was significantly higher than that of age matched WKY rats. The urinary dopamine excretion in 16-week-old SHR was significantly higher than that in age-matched WKY rats, although urine volume and urinary sodium excretion were the same as those in the control in both sodium-loaded and -restricted state. In summary, although renal dopamine production was enhanced in SHR in the hypertensive state, dopamine was found not to contribute to natriuresis since the number of dopamine receptors was reduced in these rats. We also found that enhanced dopamine production in response to a salt load was lacking in these rats. These two pathological phenomena noted in the renal dopamine system play a role in the progression of hypertension in SHR.

Aging↗
PubMed1995

Urinary detection of type IV collagen and its increase in glomerulonephritis.

Type IV collagen is the major component of the glomerular extracellular matrix. The nature of type IV collagen antigens in the urine from various forms of glomerulonephritis was studied using enzyme-linked immunosorbent assay for monoclonal antibodies to the 7S domain and some of the non-7S and non-NC1 domains. The size distribution of antigenic material in urinary samples from a patient with IgA nephropathy was analyzed by gel filtration chromatography. The results demonstrated a single peak at 340 kDa, suggesting the measurement of almost intact type IV collagen molecules. The urinary concentration of type IV collagen in patients with membranous nephropathy and chronic renal failure was significantly increased compared with that of normal controls. Measurement of the urinary concentrations of type IV collagen is useful in the diagnosis of glomerular disease, particularly in cases where invasive methods are contraindicated and clinically membranous nephropathy is suspected.

Adolescent↗
PubMed1995

[A case of systemic lupus erythematosus associated with severe fibrinoid necrosis located mainly in the glomerular afferent arteriole].

We report here, a patient of systemic lupus erythematosus (SLE) with severe fibrinoid necrosis in the afferent arteriole of the glomerulus, in whom antiphospholipid antibody might have contributed to the pathogenesis. A 24-year-old female who was suffering from severe anemia with fragmented red blood cells, acute renal failure and thrombocytopenia, was admitted to our hospital. Further examinations revealed findings compatible with active lupus nephritis. Moreover, she was found to be positive for antiphospholipid antibody, and anticardiolipin antibody, as well as for lupus anticoagulant and syphilis test. Intensive treatment by methylprednisolone pulse therapy, hemodialysis, and double filtration plasmapheresis were performed. However, 13 days after admission she died suddenly because of intracranial hemorrhage. Pathological investigation of renal tissue revealed severe fibrinoid necrosis of the arterioles mainly in the glomerular afferent arteriole associated with diffuse proliferative lupus nephritis. In this case, hemolytic uremic syndrome (HUS) was associated with SLE. Antiphospholipid antibody was considered to be not only an accelerator in the arterial lesions of HUS, but also an initiator of HUS itself.

Adult↗
PubMed1995

Changes in soluble ICAM-1 level during hemodialysis.

Intercellular adhesion molecule-1 (ICAM-1) is expressed on the surface of various types of cells, including lymphocytes, monocytes and vascular endothelial cells. Recently, ICAM-1 was reported to be shed from the cell membranes and released into circulation. The soluble ICAM-1 (sICAM-1) level has been reported to be increased in patients with certain inflammatory diseases. It is well known that the functions of leukocytes including neutrophils, lymphocytes and monocytes are impaired in patients with chronic hemodialysis. In this study, we evaluated the effect of hemodialysis (HD) on the lymphocytes and monocytes by periodically measuring the serum concentration of sICAM-1 during HD. Pre-HD sICAM-1 levels in chronic hemodialysis patients were significantly increased as compared with healthy subjects. Two hundred and forty minutes after the start of HD, sICAM-1 levels were significantly higher than the pre-HD levels. The sICAM-1 levels at the venous side of the dialyzer were significantly increased compared with the levels at the arterial side. There was no significant difference between the sICAM-1 levels of the patients under hemodialysis with the regenerated cellulose membrane and those with the polymethylmethacrylate membrane. These results suggest that ICAM-1 is shed from the surface of mononuclear cells (lymphocytes and monocytes) and released into circulation stimulated by hemodialysis membranes. Chronic hemodialysis may impair the function of mononuclear cells by inducing the shedding of ICAM-1.

Aged↗
PubMed1995

A comparative study of myocardial troponin T levels in patients undergoing hemodialysis.

This study included 25 patients receiving hemodialysis (HD) but in whom diabetes mellitus was not the primary disease (HD-non DM group), 25 patients receiving hemodialysis with diabetes mellitus as the primary disease (HD-DM group), and 50 patients with diabetes mellitus who had not yet been treated with hemodialysis (DM group). The following markers of myocardial injury were measured in these patients: troponin T (TnT), creatine kinase (CK), myoglobin (Mb), and myosin light chain-1 (MLC-1). No significant correlation was found between myocardial TnT and Cr in any study group. The Mb and MLC-1 values in patients receiving HD were markedly higher than normal regardless of the primary disease involvement, while myocardial TnT was found to be only slightly abnormal. These results suggest that myocardial TnT may be a more useful marker of myocardial injury in HD patients than the markers in current use. In the present investigation, myocardial TnT was the only marker that was higher in the HD-DM group than in the HD-non DM group. This suggests the possibility that the HD-DM group included more patients with arteriosclerotic lesions, such as myocardial injury.

Aged↗