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Biomedical subjects

K Okada

Publications and source records attributed to K Okada.

At least 937 records · Page 52Linked to original sources
PubMed1992

Analysis of binding protein for tissue-type plasminogen activator in human endothelial cells.

The specific binding sites for tissue-type plasminogen activator (t-PA) were investigated in human umbilical vein endothelial cells. After adding 125I-t-PA (M.W. 70 kDa) to endothelial cells in suspension culture, the ligand was recovered from the cell extract after disuccinimidyl suberate treatment as a high molecular complex with M.W. of 90 kDa on SDS-PAGE. The complex reacted to only anti-t-PA IgG but not to anti-PAI-1 IgG immunoblot analysis, indicating a t-PA specific binding protein. 125I-t-PA ligand blotting of the cell extract revealed that the binding protein had M.W. 20 kDa. The binding of 125I-t-PA to endothelial cells was reduced in the presence of an excess amount of t-PA, plasminogen and 6-aminohexanoic acid, indicating that the binding sites were also recognized by plasminogen, and that t-PA and plasminogen were bound via lysine binding sites in the molecule. These findings suggest that human endothelial cells have specific t-PA binding molecules which may be expressed on the cell surface as t-PA receptors.

Aminocaproic Acid↗
PubMed1992

Experimental studies on biochemical modulation targeting topoisomerase I and II in human tumor xenografts in nude mice.

Topoisomerase (topo) I and II are nuclear enzymes which are novel targets of cancer chemotherapy. A new camptothecin (CPT) analog, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyl-oxy-CPT (CPT-11), is a topo-I inhibitor with a higher activity and less toxicity than CPT. To investigate topo-I and -II-targeting chemotherapy in an in vivo model, we studied the effect of sequential or co-treatment using CPT-11 and adriamycin (ADR) a topo-II inhibitor, in 6 human tumor xenografts (2 esophageal, 2 gastric and 2 colon tumor lines). In sequential treatment, adriamycin was administered i.v. 24 hr after CPT-11 treatment, and no antagonistic effect of this treatment schedule was observed. ADR cytotoxicity was potentiated significantly by CPT-11 pretreatment in the case of 2 esophageal and 2 gastric tumor lines and 1 colon tumor line. On the other hand, co-treatment abolished the sensitivity to CPT-11 and ADR in all 6 tumor lines. Moreover, CPT-11 did not significantly enhance the cytotoxicity of other agents tested, including mitomycin C (MMC) and cisplatin (CDDP). Flow cytometry and dot-blot analyses showed that CPT-11 pretreatment induced an increase in the S-phase cell population with an increase of topo-II mRNA expression after 24 and 48 hr, respectively, in the esophageal and colon tumor lines. These results suggest that CPT-11 can modulate topo-11 levels to enhance the effect of topo-II inhibitors in some human tumors, and this suggests a new clinical method of topo-I and -II targeting chemotherapy for human solid tumors.

Animals↗
PubMed1992

Biochemical properties of endothelin converting enzyme in renal epithelial cell lines.

This is the first report clearly demonstrating the presence of endothelin (ET) converting enzyme (ECE) in non-vascular cells (renal epithelial cell lines, MDCK and LLC-PK1). ECEs derived from these epithelial cells were very similar to the endothelial ECE in the following biochemical properties: 1) The optimum pH was 7.0; 2) the Km value for big ET-1 was approximately 30 microM; 3) the enzyme was potently inhibited by EDTA, o-phenanthroline and phosphoramidon; and 4) the enzyme did not convert big ET-2 or big ET-3. These data suggest that phosphoramidon-sensitive ECE is involved in the processing of big ET-1 to ET-1 in the renal tubule.

Animals↗
PubMed1992

Tissue-type plasminogen activator and its inhibitor in human glomerulonephritis.

We carried out an immunohistochemical study of tissue-type plasminogen activator (PA) and urokinase-type PA, and their inhibitors, PA inhibitor-1 and PA inhibitor-2, using renal biopsy specimens obtained from 86 patients with various forms of glomerulonephritis. The controls were four normal renal tissue specimens. On immunofluorescent observation, granular staining for tissue-type PA was found to be distributed along the glomerular capillary walls. The fluorescence was weak in the normal renal tissue and occasionally intense in the tissues of patients with IgA nephritis, minimal change nephrotic syndrome, and lupus nephritis. PA inhibitor-1 was abundant in the glomerular epithelial cells and scarce in the mesangial area and glomerular capillary lumens of the normal renal tissues. This was confirmed by immunoelectron microscopy using gold staining. The fluorescence of PA inhibitor-1 was weaker in some specimens of nephritic tissues than in the normal renal tissues. Urokinase-type PA and PA inhibitor-2 were negative within the glomeruli in all the specimens. In the glomerulonephritic tissues which were fibrin deposition-positive, tissue-type PA expression in the glomeruli tended to be strong. An association between fibrin deposition and PA inhibitor-1 staining was not clear. These data suggest that expression of tissue-type PA in the glomeruli increases in association with fibrin deposition.

Fibrin↗
PubMed1992

Clinical study of bone-related relapse in prostate carcinoma.

Prostate carcinoma is usually highly responsive to initial endocrine therapy. However, when relapse occurs, the subsequent clinical course is very poor. In this study, we tried to reveal the clinical aspects of bone-related relapse in 392 patients who received endocrine therapy for prostate carcinoma. In 17 stage B patients who had relapsed, 76% experienced relapse within 4 years following the start of treatment, 76% within 3 years in 27 stage C patients, and 71% within 2.5 years found in 45 stage D patients. Pre-treatment levels of serum enzymes and initial response of the primary lesion and of serum enzymes failed to predict relapse. The Gleason sum tended to be correlated with relapse. In particular, patients with a Gleason sum of 9-10 had a lower non-relapse rate during the follow-up period than patients with lower sums. With the recent use of more sophisticated measurements of PSA and/or PAP, the reduction rate or interval to normalization of the markers must be more relevant to predicting relapse.

Acid Phosphatase↗
PubMed1992

Evaluation of transcatheter arterial embolization with epirubicin-lipiodol emulsion for hepatocellular carcinoma.

A total of 18 patients with hepatocellular carcinoma (HCC) were treated by transcatheter arterial embolization (TAE) with a 4'-epi-doxorubicin (EDX)-lipiodol emulsion. Infusion of the EDX-lipiodol emulsion (EDX-L) via the hepatic artery was followed by the injection of gelatin sponge in 12 cases. The response and survival of these 12 patients following EDX-L treatment were compared with those of 42 subjects treated with a doxorubicin-lipiodol emulsion (DX-L) and those of 23 patients treated by TAE with gelatin sponge (GS) only. In the group treated with EDX-L, nine cases were AFP-positive in sera and four showed a decrease in serum AFP values to less than 10% of the pretreatment level. Seven cases showed a partial response, and nine cases showed no change in the size of the tumor. In the group treated with EDX-L, nine cases are alive, and the oldest has survived for more than 431 days since the treatment. The half-year survival value was 57%, and the 1-year survival value was 49%. These values did not differ significantly from those calculated for the group treated with DX-L. The 1-year survival value determined for patients treated with a lipiodol emulsion (EDX-L or DX-L) followed by GS was 65%, and the 2-year survival value was 39%. These results rates are significantly better than those obtained in patients treated with GS only (1-year survival, 39%; 2-year survival, 13%.

Aged↗
PubMed1992

The inflammatory cytokines in measles: correlation between serum interferon-gamma levels and lymphocyte subpopulations.

Interleukin-1 (IL-1 beta), tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) were measured in serum from children with measles using an immunoradiometric assay. The IFN-gamma level was increased in 52 out of 54 patients in the acute phase of measles (less than 7 days of illness), and then declined to an undetectable level in the convalescent phase. Neither IL-1 nor TNF could be detected during the course of the illness. The mean serum IFN-gamma level was at its peak on day 4 and could be detected over a 7-day period after the onset of fever, coinciding with the febrile period (6.9 +/- 1.5 days). In the acute phase, the phytohaemagglutinin responses, absolute number of platelets, total lymphocyte counts, CD3+, CD4+, CD8+ cell counts and the CD4/8 ratio were depressed, while stab cell number and lactate dehydrogenase levels were higher than those in the convalescent phase. Using Spearman rank sum test, the IFN-gamma level was correlated negatively with the peripheral lymphocyte (P less than 0.01), CD3+ (P less than 0.05), CD4+ (P less than 0.05) cell counts and the CD4/8 ratio (P less than 0.05) and correlated positively with the stab cell count (P less than 0.01) but not with any other parameter. When the acute phase findings were compared between 28 complicated and 40 uncomplicated patients, the former were younger (P less than 0.01) and had higher maximum body temperature during the illness (P less than 0.05) than the latter, there was no difference in their IFN-gamma levels. These results show that endogenous IFN-gamma appears in the circulation during the acute febrile phase of measles, but does not contribute directly to any complication of the disease.

Acute Disease↗
PubMed1992

Extracorporeal shock wave lithotripsy and xanthine calculi in Lesch-Nyhan syndrome.

We report a case of Lesch-Nyhan syndrome (LNS) with urinary xanthine calculi. At eight years of age calculi in the renal pelvis were successfully disintegrated by extracorporeal shock wave lithotripsy (ESWL) without any complications. Follow-up sonography is very useful for management of patients with LNS, particularly when they are on allopurinol therapy.

Allopurinol↗
PubMed1992

The potentiating effect of KC-404 on prostacyclin-induced vasodilation in isolated human cerebral artery.

1. KC-404 (10(-9)-10(-6) g/ml) produced concentration-dependent relaxations in human middle cerebral arteries contracted with prostaglandin F2 alpha. 2. KC-404 (10(-8) and 10(-7) g/ml) has the ability to significantly potentiate prostaglandin I2-induced relaxations in human middle cerebral arteries. 3. KC-404, at least in low concentrations, may elicit human cerebral vasodilation predominantly by potentiating relaxant responses to prostaglandin I2 produced spontaneously in vascular wall. 4. KC-404 is expected to increase cerebral blood flow at least by dilation of major cerebral arteries, and this agent may be beneficial for the treatment of cerebrovascular disorders.

Cerebral Arteries↗
PubMed1992

Sex determination by discriminant function analysis of lateral cranial form.

To sex the cranium, morphological features of cranial specimens were quantified with a personal computer that automatically measures distance and gradient for 39 craniometric points in the lateral contour line of the skull, which were digitized by a tablet digitizer connected to the computer. Specimens used for discriminant analysis were 50 male and 50 female adult Japanese skulls. The lateral contour showed sex differences in the nasal bone, supraorbital ridge, forehead and vertex. The nasal bone and supraorbital ridge were more developed in male contour line, and the forehead was more rounded in female contour line. But compared with the supraorbital ridge and forehead, the vertex had a wide variety of contour lines in both sexes. The vertex seemed to be less reliable as the indicator of sex. The sex differences were better reflected by gradient than distance. From variables of the gradient and distance showing significant sex differences, the discriminant function was derived and tested in 21 other specimens (13 male and 8 female skulls). The mean ratio of correct sexing of the human skull by the discriminant function was 86%.

Adult↗
PubMed1992

Balloon cystoscopy with neodymium:YAG laser.

We performed balloon cystoscopy for the diagnosis of gross hematuria as well as for the treatment of bladder tumor using the neodymium:YAG laser. Animal experiments were done to evaluate the efficacy of laser irradiation through the balloon, which proved to have the same effect as conventional laser irradiation. A total of 40 patients with bladder diseases was observed and treated by balloon cystoscopy, and the results were examined comparatively. Even with gross hematuria the structure of the mucosa and the tumor could be observed in detail without irrigating the inside of the bladder. Most bladder tumors were successfully treated with laser irradiation through the balloon through the optic lens system. Therefore, balloon cystoscopy appears to be a useful endoscopic modality in neodymium:YAG laser surgery for the treatment of bladder tumor.

Animals↗
PubMed1992

A monoclonal antibody (1G10) recognizes a novel human mesangial antigen.

We have identified a unique mesangial matrix protein of the human glomerulus by using a monoclonal antibody, 1G10, generated against culture human glomerular cells. By immunofluorescence, the antigen recognized by 1G10 (1G10 antigen) is present in mesangium and smooth muscle tissue and cannot be detected in any other tissue examined. Immunoelectron microscopy of glomeruli indicated that 1G10 antigen is present exclusively in the mesangial matrix at the endothelial-mesangial interface. The 1G10 antigen is also expressed by cultured mesangial cells, but not by cultured glomerular epithelial cells, umbilical endothelial cells or fibroblasts. 1G10 did not react with the mesangial matrix proteins [fibronectin (FN), laminin (LAM), collagen types I, III, IV, V, and VI (Col I, III, IV, V, VI), heparin sulfate proteoglycan (HSPG), or thrombospondin (TS)] present under normal and diseased states or smooth muscle antigens (myosin, actin), but did react with a 4 M urea extract of renal cortex and a 0.3% deoxycholate extract of isolated glomeruli. Two dimensional immunoblot analysis using the urea extract demonstrated the binding of 1G10 to an approximately 200 KDa polypeptide with pI 6.0. On one dimensional immunoblot this band did not show cross react with polyclonal antisera to FN, LAM, Col IV, V, VI, HSPG or TS. This mesangial matrix component is trypsin and periodate sensitive, suggesting that it has the character of glycoprotein. In renal biopsy specimens from patients with mesangial proliferative glomerulonephritis (GN) and membranoproliferative GN, the expression of the 1G10 antigen increased along with mesangial hypercellularity or increased accumulation of mesangial matrix, but decreased in completely sclerosed glomeruli. No significant changes in 1G10 antigen expression was observed in membranous GN or minimal change nephrosis compared to normal glomeruli. This study suggests that the 1G10 antigen may not only be a useful marker for the clinical assessment of GN, but may also serve as a potential tool for the study of the pathogenesis of glomerular diseases characterized by cellular proliferation and mesangial matrix expansion.

Animals↗
PubMed1992

The effect of humoral and cell-mediated immunity in resistance to systemic Serratia infection.

Protection against experimental Serratia marcescens infection in mice was enhanced by prior injection of formalin-killed or viable bacteria of the same strain. From the first to the fourth week after vaccination, specific immunity was involved in the host defence against systemic serratia infection. The transfer of antiserum specific for S. marcescens increased bacterial clearance from the liver, but did not increase the survival of the mice. Bacterial clearance from the liver was also increased by the transfer of spleen cells from immunised mice, but, again, survival was not increased. However, the transfer of both antiserum and spleen cells from vaccinated mice increased both bacterial clearance from the liver and survival (p less than 0.01). These results suggest an additive effect of humoral immunity and T-cell-mediated immunity in protection against systemic serratia infection.

Animals↗