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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 235 records · Page 13Linked to original sources
PubMed1994

Anti-annexin V antibody in systemic lupus erythematosus patients with lupus anticoagulant and/or anticardiolipin antibody.

We investigated anti-annexin V antibody (aANX) in patients with systemic lupus erythematosus (SLE), and correlated to positivity with lupus anticoagulant (LA)/anticardiolipin antibody (aCL). aANX was positive in 12/47 SLE patients (26%), including 7 with beta 2-glycoprotein 1 (GPI)-dependent aANX. The positivity of aANX was higher in patients with aCL (19%) and LA/aCL (50%) than in those without LA/aCL (10%). From these results, it is concluded that aANX is an autoantibody closely related to LA/aCL, and can be a possible new risk marker for thrombosis.

Annexin A5↗
PubMed1994

Detection of endogenous albumin as an index of blood parenchymal border alteration.

We used a microdialysis technique to establish a method to detect sequential changes in disruption of the blood parenchymal border. Twelve cats were divided into two groups; one group underwent occlusion of the middle cerebral artery for 60 minutes, the other a cold injury model. Microdialysis probes were implanted bilaterally into the white matter, and dialysates were collected successively at 30 minute intervals for 6 hours in the occlusion model and 4 hours in the cold injury model. Regional cerebral blood flow was measured simultaneously using the hydrogen clearance method. The water content of the white matter was measured using specific gravity. The proteins in the dialysate were analyzed using electrophoresis with silver stain, and, with densitometric analysis, the density of the 66.2 kDa band was quantified as albumin. The ratio of this density to the preoperative density was defined as the "albumin index." On the side of the lesion in the cold injury model, this index significantly increased 3 hours after the cold injury compared with the contralateral side, and a correlation between the water content and this index was observed. The albumin index was believed to indicate the severity of disruption of the blood parenchymal border.

Animals↗
PubMed1994

Endogenous superoxide dismutase activity in reperfusion injuries.

To elucidate the relationship between reperfusion injuries and free radicals, we monitored the endogenous superoxide dismutase (SOD) activity by intracerebral microdialysis. Six cats underwent a transient occlusion of the middle cerebral artery for 60 minutes after microdialysis probes were implanted bilaterally into the white matter under the ectosylvian gyrus. Dialysates were collected at 30 minute intervals over the course of 5 hours after reperfusion. The SOD activity of the dialysates was measured with electron spin resonance spectrometry. Regional cerebral blood flow was measured simultaneously and the water content of the white matter was assayed at the end of the experiment. After reperfusion, SOD activity increased significantly in the first 30 minutes compared with the preoperative value, and decreased over 4-4.5 hours and 4.5-5 hours in the occluded side. The water content in the occluded side was significantly higher than that in the contralateral side. The highest SOD activity during reperfusion and the water content in the occluded side seemed to correlate, although not significantly. A leakage of intracellular SOD or a reactive increase of SOD activity in response to the reperfusion injury are possible mechanisms of increase in extracellular SOD.

Animals↗
PubMed1994

New development of transarterial immunoembolization (TIE) for therapy of hepatocellular carcinoma with intrahepatic metastases.

The prognosis of patients with multiple hepatocellular carcinoma (HCC) remains disappointing. In this study, we devised a new therapeutic modality for HCC consisting of transarterial immunoembolization (TIE) using OK-432 and fibrinogen and then analyzed the preliminary results. In the first series, we applied the treatment to 19 patients with advanced HCC who had proved to be insensitive to several previous conventional treatments. In all, 14 patients (74%) with unresected HCC have currently survived for between 2 and 16 months after TIE. The remaining 5 patients died at 17, 14, 8, 7, and 4 months after TIE. The serum levels of tumor markers decreased in all of the patients, and a marked reduction in tumor size was observed in six patients after TIE. A high fever occurred in all cases, and abdominal pain and loss of appetite were also observed after TIE. However, deterioration of liver function was negligible. After confirmation of the safety of this method, we started a second study series in which this TIE treatment was selected as the first choice. Six patients have been treated to date. All patients in this group underwent hepatic resection at 6-48 days following TIE. Histological examination of the resected specimens following TIE showed massive infiltration of mononuclear cells around tumor cell nests and lytic necrosis as well as coagulation necrosis of the main tumor and the intrahepatic metastases. In conclusion, our results indicate that TIE may be a safe and promising therapy for patients with HCC.

Adult↗
PubMed1994

Desensitization of prostaglandin F2 alpha receptor-mediated phosphoinositide hydrolysis in cultured rat astrocytes.

Desensitization of prostaglandin (PG) F2 alpha receptor-mediated phosphoinositide (PI) hydrolysis was investigated in cultured rat astrocytes. Prolonged exposure of astrocytes differentiated by dibutyryl cyclic AMP-treatment to PGF2 alpha caused the desensitization of subsequent PGF2 alpha-induced PI hydrolysis. The desensitization was time- and PGF2 alpha dose-dependent; maximal decrease in the PI hydrolysis was observed after exposure to 10 microM PGF2 alpha for 4 h and the degree of the desensitization was 31.7 +/- 2.7% of control. Pretreatment with either PGD2 or PGE2 also induced the desensitization of subsequent PGF2 alpha-stimulated PI hydrolysis and conversely pretreatment of PGF2 alpha decreased the PI responses to PGD2 and PGE2. The desensitization prevented by phloretin and was reversible upon removal of the agonist. Protein synthesis inhibitors blocked the recovery of the desensitization. Treatment of the cells with phorbol 12-myristate 13-acetate had no effect on the desensitization. These results suggest that prolonged exposure of the astrocytes to PGF2 alpha caused the desensitization of the receptors.

Animals↗
PubMed1994

Tunicamycin inhibits prostaglandin F2 alpha receptor-mediated phosphoinositide hydrolysis in cultured rat astrocytes.

Effect of tunicamycin, an inhibitor of N-linked glycosylation, on prostaglandin (PG) F2 alpha-stimulated phosphoinositide (PI) hydrolysis was examined in cultured rat astrocytes. Pretreatment of cultured astrocytes with tunicamycin (25-250 ng/ml) inhibited subsequent PGF2 alpha (1 microM)-stimulated PI-hydrolysis in concentration- and time-dependent manners. The inhibition completely recovered after removal of tunicamycin and re-incubation for 12 h. Tunicamycin pretreatment (100 ng/ml for 12 h) significantly blocked [35S]methionine incorporation into cultured astrocytes, but cell viability was not affected under the condition. Inhibitors of processing of N-linked sugar chains such as bromoconduritol, 1-deoxymannojirimycin, and swainsonine had no effect on PI response to PGF2 alpha. These observations suggest that PGF2 alpha receptor is N-linked glycosylated.

Animals↗
PubMed1994

Plasma concentrations of total/free and functional protein S are not decreased in systemic lupus erythematosus patients with lupus anticoagulant and/or antiphospholipid antibodies.

We conducted an investigation to clarify whether or not the levels of total, free, and functional protein S and C4-binding protein (C4bp) in plasma are decreased in systemic lupus erythematosus (SLE) patients, especially those with antiphospholipid antibody (aPL), which is known to be a causative factor of such complications as habitual abortion and arteriovenous thrombosis. Fifty patients with SLE were recruited as subjects of the study. Serum aPL (anticardiolipin, antiphosphatidyl serine, antiphosphatidyl inositol, and antiphosphatidic acid antibodies) were measured by ELISA. Lupus anticoagulant was determined by a PTT, KCT, and diluted RVVT. Furthermore, plasma concentrations of total, free, and functional protein S and C4bp were measured. There were no significant differences in the mean levels of total, free, or functional protein S and C4bp between aPL-positive, aPL-negative SLE patients, and the healthy controls. From these results, we concluded that the protein S level is not the sole factor causing complications, and that other factor(s) may be involved in the induction of such complications in this clinical setting.

Antibodies, Antiphospholipid↗
PubMed1994

Natural flavonoids and lignans are potent cytostatic agents against human leukemic HL-60 cells.

Anti leukemic-cell efficacy of 28 naturally occurring and synthetic flavonoids and 11 naturally occurring lignans on human promyelocytic leukemic cell line HL-60 were examined using MTT assay methods. Differences between anti cell-proliferative activity and cytotoxicity of these compounds were compared with those of 4 clinical anti-cancer agents. Eight of the 28 flavonoids and 4 of the 11 lignans showed considerable suppressive effects on HL-60 cell growth with IC50s ranging from 10-940 ng/ml. Among these compounds, genistein, honokiol, machilin A, matairesinol, and arctigenin had the strongest effects with IC50s less than 100 ng/ml, which were almost equivalent to the effects of current anti-cancer agents. The flavonoid genistein and the lignans, however, showed little or no cytotoxicity against HL-60 cells as assessed by dye exclusion tests (LC50s > 2,900 ng/ml), whereas the regular anti-cancer agents had potent cytotoxicity. All of the flavonoids and lignans, except for machilin A and arctigenin, were less effective against growth of human T lymphocytic leukemia cell line MOLT-4. In addition, the flavonoid and the lignans showed little or no inhibiting activity on mitogen-induced blastogenesis of human peripheral-blood lymphocytes. The lignans and genistein were strongly suppressive against incorporations of [3H]thymidine, [3H]uridine, and [3H]leucine into HL-60 cells. These results showed that some of the naturally occurring flavonoids and lignans inhibited HL-60 cell growth with a non-toxic mechanism, possibly via cessation of DNA, RNA, and/or protein synthesis of the leukemic cells.

Antineoplastic Agents↗
PubMed1994

Cloning and expression of a cDNA for rat prostaglandin F2 alpha receptor.

We have cloned a cDNA for rat prostaglandin (PG) F2 alpha receptor from cultured rat astrocytes. The cDNA encodes a polypeptide of 366 amino acids with seven putative transmembrane domains. Specific binding of [3H]PGF2 alpha in membranes of COS-7 cells transfected with the cDNA was displaced with unlabeled PGs in the order of PGF2 alpha > PGD2 > PGE2 > PGI2. In the cDNA-transfected LLC-PK1 cells, PGF2 alpha stimulated phosphoinositide hydrolysis. A significant 4.7-kb mRNA transcript was detected in cultured rat astrocytes and whole brain and pregnant ovary of adult rats by Northern blot analysis.

Amino Acid Sequence↗
PubMed1994

Superoxide scavenging activity in vitro and in the cerebral extracellular space measured by microdialysis.

Using the electron spin resonance (ESR) spin-trapping method and a high molecular cut-off membrane, we measured the superoxide scavenging activity in dialysates obtained from microdialysis. The activity in the dialysates of the Cu,Zn-superoxide dismutase (SOD) solution and feline serum were measured in vitro, and the recovery rate was calculated to be 12.88 +/- 0.9% in Cu,Zn-SOD solution and 21.52 +/- 4.38 in feline serum, which was significantly different. This difference was believed to originate from the higher osmotic pressure due to proteins in the serum and substances other than Cu,Zn-SOD that acted as antioxidants in the serum. In an in vivo study, microdialysis probes were implanted into the cerebral hemispheres in 6 cats. The sequential changes of superoxide scavenging activity were measured for 16 h and during induced cardiac arrest. No significant difference was observed and the microdialysis technique itself did not seem to cause the significant alteration of the activity in the extracellular space, although at cardiac arrest, the activity varied widely. This method can be used to study the reaction against superoxide injury in further experiments involving brain insult.

Animals↗
PubMed1994

Preliminary report on an automated screening test for detection of antibody to human immunodeficiency virus type 1 in whole blood.

We developed and evaluated an automated screening test for antibody to human immunodeficiency virus type 1 (HIV-1) using EDTA-2Na-treated whole blood and an extract of paper disk-absorbed dried whole blood from 60 hemophiliacs infected with HIV-1 and 210 diseased and healthy controls. The specificity and the sensitivity of this system were judged to be 100% with both the whole blood and the extract. This test allows measurement of HIV-1 antibody in whole blood and dried whole blood on a small paper disk and gives a result within 13 minutes; the system can process 150 samples per hour. Therefore, it may be useful at many testing sites, such as emergency departments, intensive care units, blood banks, and commercial laboratories, as well as for mail-order testing from remote areas and developing countries.

AIDS Serodiagnosis↗
PubMed1994

Low temperature collagenase digestion for islet isolation from 48-hour cold-preserved rat pancreas.

We examined the efficacy of relatively low temperature collagenase digestion at 20 degrees C on the yield and viability of islets after long-term cold preservation. Wistar rat pancreases were distended with University of Wisconsin solution via a pancreatic duct at the time of harvesting to which collagenase and 2.5 mM calcium chloride were added. The pancreases were cold-preserved at 4 degrees C for 24 or 48 hr. After storage, they were incubated for collagenase digestion at 37 degrees C or 20 degrees C for various incubation periods to obtain the peak yield. At 20 degrees C, in vitro collagenase activity measured by the FALGPA method was one fourth of that at 37 degrees C, and pancreases were well digested with a prolonged digestion period (60-90 min vs. 15-20 min for the 37 degrees C group). In vitro insulin secretion of islets isolated from freshly removed pancreases was maintained at 20 degrees C for 120 min in University of Wisconsin solution as compared with 30 min at 37 degrees C. Therefore, the preserved pancreases used in this study were incubated either at 37 degrees C or 20 degrees C at various times in order to obtain peak islet yields. The islet yields from 24-hr cold-preserved pancreases at 37 degrees C and 20 degrees C digestion were 573 +/- 59/rat (n = 6) and 497 +/- 84/rat (n = 11), respectively, and those from 48-hr cold-preserved pancreases were 395 +/- 113/rat (n = 6) and 414 +/- 75/rat (n = 6), respectively. The yields from 24- and 48-hr cold-preserved pancreases were significantly low compared with 635 +/- 52/rat for fresh pancreases (n = 15), but there was no significant difference between the 2 methods. The viability of the isolated islets, which was examined by transplantation to streptozotocin-induced diabetic C57BL/6 mice, showed a significant difference in the capacity to ameliorate diabetes. The functional success rate of islet transplantation after 24-hr cold preservation was equally good (8/8 for 37 degrees C group vs. 9/10 for 20 degrees C group), but the rate for those from 48-hr cold-preserved pancreases was significantly better with digestion at 20 degrees C than at 37 degrees C (1/8 for 37 degrees C group vs. 7/8 for 20 degrees C group, P < 0.05). We concluded that viable islets can be isolated from 48-hr cold-preserved pancreases with the low temperature collagenase digestion method, which shows promise as a modality for successful clinical islet transplantation.

Animals↗