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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 163 records · Page 9Linked to original sources
PubMed1996

Increased Fas antigen on T cells in multiple sclerosis.

Programmed cell death of antigen specific T cells (apoptosis) may be an important process in the pathogenesis of autoimmune diseases such as multiple sclerosis (MS). Fas antigen was recognized as an apoptosis-related antigen. To investigate Fas antigen in multiple sclerosis (MS), we measured the expression rate of Fas antigen and activation markers on T cells in peripheral blood (PB) of 19 MS patients, 18 controls and in cerebrospinal fluid (CSF) of nine MS patients by flow cytometry. The positive rate of Fas antigen in MS patients was higher than that of healthy controls in PB. In patients with MS, the expression rates of Fas antigen and activation markers were higher in CSF than in PB. The above findings suggest that there is acceleration or impairment of apoptosis on activated T cells in MS.

Antigens, CD↗
PubMed1996

Systemic hemodynamics and serum nitrate levels in patients undergoing endoscopic variceal ligation.

The effects of endoscopic variceal ligation (EVL) on systemic hemodynamics are unknown. This study was conducted to determine whether the obliteration of portal-systemic collaterals by EVL affects systemic hemodynamics and serum nitrate concentrations in patients with compensated cirrhosis. We measured systemic and hepatic hemodynamics, azygos vein blood flow (AzBF), and serum nitrate concentrations before and immediately following EVL. A prompt decrease in left ventricular end-diastolic volume (LVEDV), stroke volume, cardiac index (CI), and an increase in systemic vascular resistance index (SVRI) were observed following variceal ligation. The reduction in LVEDV was associated with a decline in CI with a rise in SVRI. There was also a prompt reduction in serum nitrate concentration following variceal ligation. AzBF also significantly decreased following variceal ligation. These findings indicate that EVL decreased cardiac output via a reduction in cardiac preload (central venous return). Blood flow through portal-systemic collaterals has an important role in the enhanced cardiac preload of cirrhotic patients. The sudden decrease in serum nitrate concentrations suggests that endogenous nitric oxide may be involved in the regulation of systemic hemodynamics in patients with compensated cirrhosis.

Aldosterone↗
PubMed1996

Effects of endoscopic variceal sclerotherapy on azygos vein blood flow and systemic haemodynamics.

The present study was designed to determine the systemic haemodynamic effects of obliterating oesophageal varices by endoscopic sclerotherapy. We evaluated systemic and splanchnic haemodynamics before and after the first course of sclerotherapy in cirrhotic patients. The baseline cardiac index was significantly correlated with baseline azygos vein blood flow (r = 0.64; P < 0.01) and the azygos vein blood flow and cardiac index significantly decreased (-33% and -16%, respectively; P < 0.01) following sclerotherapy. The systemic vascular resistance index was also increased significantly (+ 20%; P < 0.01) in these patients. Moreover, the per cent change in azygos vein blood flow was directly correlated with that of the cardiac index (r = 0.51; P < 0.03). We conclude from these findings that the obliteration of portosystemic collaterals by sclerotherapy significantly reverses hyperdynamic circulation in such patients via a decrease in cardiac preload. The blood flow of the portosystemic shunt per se is a leading contributor to the hyperdynamic circulation observed in patients with well-developed portal systemic collateral vessels.

Adult↗
PubMed1996

Increased gene expression of insulin-like growth factor-i receptor in experimental diabetic rat glomeruli.

Renal hypertrophy is a characteristic and early manifestation of diabetes in humans and experimental animals. We examined the precise distribution of insulin-like growth factor-I (IGF-I) mRNA and IGF-I receptor mRNA in the experimental diabetic rat kidney using a nonradioactive in situ hybridization technique. No significant difference in the distribution of IGF-I mRNA was found between the diabetic and control rats. IGF-I mRNA-positive cells were found in the collecting ducts and in scattered single cells in the distal tubules. The number of IGF-I mRNA-positive cells was very low in the glomeruli. Expression of IGF-I receptor mRNA was rarely seen in the glomeruli of control rats. IGF-I receptor mRNA was detected after induction of diabetes in glomerular mesangial, visceral epithelial, and parietal epithelial cells. The number of IGF-I receptor mRNA-positive cells in a glomerulus increased significantly, peaking at 4 weeks as compared with the control rats. Overexpression of IGF-I receptor in glomerular cells, especially mesangial and visceral epithelial cells, may contribute to glomerular hypertrophy in diabetic nephropathy.

Animals↗
PubMed1996

The critical role of intercellular adhesion molecule-1 in Masugi nephritis in rats.

Intercellular adhesion molecule-1 (ICAM-1, CD54), an adhesion molecule of the immunoglobulin superfamily, is an endothelial cell surface ligand for such leukocyte integrins as lymphocyte-function-associated molecule 1 (LFA-1, CD11a/CD18), Mac-1 (CD11b/CD18) and CD43. These molecules mediate adhesive interactions between leukocytes and endothelial cells and are critically involved in infiltration of leukocytes into inflammatory lesions. We examined the expression of ICAM-1 in renal tissues of Masugi nephritis rats and directly examined the role of ICAM-1 by administration of neutralizing monoclonal antibodies (MAbs) to rat ICAM-1, LFA-1 alpha-subunit (LFA-1 alpha), beta-subunit (LFA-1 beta) and Mac-1 alpha-subunit (Mac-1 alpha). Within 3 h after injection of nephrotoxic serum, increased expression of ICAM-1 was detected in the glomeruli by in situ hybridization and an immunofluorescence study. Proteinuria was significantly suppressed by the MAbs against ICAM-1, Mac-1 alpha and LFA-1 beta. Neutrophil infiltration into the glomeruli was significantly prevented by injection of the MAbs against ICAM-1, LFA-1 alpha and LFA-1 beta. These results indicate that both ICAM-1/LFA-1 and ICAM-1/Mac-1 pathways are involved in neutrophil infiltration into the glomeruli. On the other hand, monocytic infiltration was prevented by the MAbs against ICAM-1, LFA-1 alpha and LFA-1 beta but not by anti-Mac-1 alpha MAb. Due to these results, ICAM-1 is considered to be a critical molecule involved in the pathogenesis of the leukocyte infiltration into the glomeruli in the heterologous phase of Masugi nephritis. Anti-ICAM-1 antibody may be beneficial in the treatment of leukocyte-mediated glomerular diseases.

Animals↗
PubMed1996

Effects of 19-oxygenated lanosterol derivatives on 3-hydroxy-3-methylglutaryl coenzyme a reductase activity and lanosterol demethylase activity.

The effects of 19-oxygenated lanosterol derivatives on lanosterol 14 alpha-demethylase (P-450(14DM)) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity were studied. 3 beta-Hydroxylanost-9(11)-en-19-oic acid (6) was found to be an effective inhibitor (IC50:0.5 microM) of P-450(14DM) in the reconstituted system using purified pig liver P-450(14DM) and was most active in inhibiting HMG-CoA reductase activity (IC50:1.0 microM) in mouse L cells. In [2-14C]acetate incorporation studies using mouse L cells, 6 was found to reduce the incorporation of acetate into C27-sterol (desmosterol) with a concomitant increase in radiolabeled C30-sterols. These results demonstrate that 6 is a dual-action inhibitor of cholesterol biosynthesis.

Acetates↗
PubMed1996

Cortical laminar necrosis and central pontine myelinolysis in a patient with Sheehan syndrome and severe hyponatremia.

Hypoxic encephalopathy and osmotic demyelination are independent clinical entities. We describe a rare case with these two complications as demonstrated by magnetic resonance imaging (MRI). A 58-year-old woman had adrenal crises twice a decade due to Sheehan syndrome. At the second crisis, hyponatremia was remarkable with consciousness disturbance which was rapidly corrected by intravenous administration of glucocorticoid and hypertonic saline. The maneuver improved consciousness disturbance, but resulted in hypokalemic ventricular fibrillation with circulatory failure. After the normalization of the circulation, however, her consciousness level deteriorated again. Repeated brain MRI revealed acute and chronic phases of cortical laminar necrosis and central pontine myelinolysis.

Brain↗
PubMed1996

A variety of clinical applicabilities of immobilized dextran sulphate as lipoprotein adsorbent and avoidance of anaphylactoid (anion-blood contact) reaction in its use.

Dyslipidemia including hyper-LDL(low density lipoprotein) cholesterol which is very often refractory to dietary/medical treatments is known to be a risk factor of many arteriosclerotic lesions. An extracorporeal procedure of plasma adsorption, LDL adsorption, utilizing dextran sulphate as a ligand immobilized on cellulose gel beads has been clinically applied in a variety of dyslipidemic conditions as listed below. Its usefulness in secure reduction of the serum LDL level and consequent symptomatic improvements has been confirmed. Familial hypercholesterolemia(FH): A regular repetition of the LDL adsorption ameliorates hyper-LDL cholesterolemia as resulting in regression of the multiple stenoses in the coronary arteries. Focal glomerulosclerosis(FGS): A seesion of the LDL adsorption improves kidney function and reduces a urinary protein excretion in FGS patients with dyslipidemia. Arteriosclerosis obliterans(ASO): More than 60 ASO patients with dyslipidemia have been treated by the LDL adsorption in our center. In over 80% of the patients, marked improvement in clinical symptoms such as leg pain/intermittent claudication has been brought out. Hemodialysis-relevant dyslipidemia(HDDL): HDDL which develops in the long-term HD patients has been treated. Transplantation-relevant dyslipidemia(TXDL): TXDL with deterioration of the transplanted kideny function has been treated by the LDL adsorption. Kidney function improves. Anaphylactoid reaction which is tentatively explained as a result of release of bradykinin in contact of blood with polyanionic material of the adsorbent, dextran sulphate, develops, in particular, while an angiotensin-converting enzyme inhibitor is administered as a depressant. However, it can be avoided in a use of nafmostat mesilate, a protease inhibitor, as an anticoagulant.

Adsorption↗