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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 163 records · Page 9Linked to original sources
PubMed1997

[The change of hepatic energy status after transcatheter arterial embolization (TAE) for hepatocellular carcinoma--a study using 31P-MRS].

In six patients with hepatocellular carcinoma, adenosine triphosphate (ATP) phosphomonoester (PME), phosphoric acid (Pi) and pH were measured before and after transcatheter arterial embolization (TAE), using 31P-magnetic resonance spectroscopy (MRS). The effectiveness of TAE was judged by the extent of lipiodol accumulation within the tumor and change in serum alphafetoprotein level. The pH within the tumor decreased 2-9 days after TAE in all the cases, and beta ATP/Pi ratio decreased when TAE was effective, whereas the ratio did not decrease when TAE was ineffective. The beta ATP/Pi ratio measured by 31P-MRS seems to be a useful, non-invasive marker of the anti-tumor effect of TAE, although further investigation is needed.

Adenosine Triphosphate↗
PubMed1997

[Transarterial immuno-embolization therapy in patients with hepatocellular carcinoma].

Surgical resection, transcatheter arterial embolization (TAE) and percutaneous ethanol injection therapy (PEIT) are effective for hepatocellular carcinoma (HCC), but the recurrence rate is high. We have devised a new therapy of transarterial immuno-embolization (TIE) with OK-432, fibrinogen and thrombin, and 2 cases are reported. Case 1: A 78-year-old Japanese male with HCC (diameter, 4 cm in subsegment 5) received TIE. The tumor size was markedly decreased, and the patient survived for more than 3 years without recurrence. Case 2: A 61-year-old Japanese male with HCC (diameter, 4.5 cm in segment 5) received hepatic subsegmentectomy following TIE. Histological examination of resected specimens following TIE showed massive infiltration of mononuclear cells in the main tumor. Tumor recurrence had developed three times thereafter, but was effectively treated by TIE. TIE may be an effective therapy for HCC.

Aged↗
PubMed1996

Dominant negative inhibition of the association between beta-catenin and c-erbB-2 by N-terminally deleted beta-catenin suppresses the invasion and metastasis of cancer cells.

Aberrant tyrosine phosphorylation of beta-catenin inactivates the E-cadherin-mediated cell adhesion and invasion suppressor system in cancer cells. Elucidation of the association between beta-catenin and c-erbB-2 protein prompted us to investigate whether interference with this interaction can change the invasive phenotype. In a human gastric cancer cell line, TMK-1, N-terminally deleted beta-catenin, which binds to c-erbB-2 but not to cadherin, inhibited the association between endogenous beta-catenin and c-erbB-2 protein, and suppressed the tyrosine phosphorylation of beta-catenin. Cells expressing truncated beta-catenin exhibited markedly reduced invasiveness in vitro and peritoneal metastasis in vivo, and developed an epithelial morphology. These results suggest that tyrosine phosphorylation of beta-catenin regulated by c-erbB-2 protein may play an important role in the invasion, metastasis and morphogenesis of cancer cells and that inhibition of the aberrant tyrosine phosphorylation of beta-catenin effectively prevents invasion and metastasis of cancer cells.

Animals↗
PubMed1996

Bifunctional labeling reagent for oligosaccharides to incorporate both chromophore and biotin groups.

We have developed a convenient and effective method for biotinylation of oligosaccharides at their reducing ends. A novel biotin hydrazide having a phenyl group produced the biotin adduct of N-acetyllactosamine (LacNAc) by simple incubation at 90 degrees C for 1 h. Although the biotin adduct was obtained as a mixture of several stereoisomers, one of the isomers, cyclic beta-glycoside, became predominant upon letting the reaction mixture stand in a weakly acidic state (pH 3.5). This conversion may be very advantageous for functional analysis of oligosaccharides because natural N-linked oligosaccharides exist in the cyclic beta form. The limit of detection of labeled LacNAc in reversed-phase chromatography was 330 fmol and showed good linearity in the range from 330 fmol to 261 pmol. When this procedure was applied to complex type and high mannose type N-linked oligosaccharides, the labeled oligosaccharides were easily detected and separated by reversed-phase, gel filtration, and anion exchange chromatographies. Furthermore, these labeled oligosaccharides were able to be immobilized onto the solid phase using avidin-biotin technology and were stable enough to allow the binding assay to be performed repeatedly and under the conditions for in situ exoglycosidase digestion. These results suggest that this derivatization technique might be useful for both separation and functional analysis of oligosaccharides.

Biosensing Techniques↗
PubMed1996

Immobilization stress-induced increase of hippocampal acetylcholine and of plasma epinephrine, norepinephrine and glucose in rats.

We investigated the role of the hippocampal cholinergic neurons during immobilization stress in rats using a microdialysis technique. Blood levels of glucose, epinephrine and norepinephrine during immobilization stress were also determined. Acetylcholine release was initially increased by immobilization stress, then gradually decreased. Plasma level of epinephrine increased gradually and reached significance at 30 min after the start of immobilization and remained at the elevated level during immobilization. Plasma level of norepinephrine initially increased and reached significance at 30 min after the start of immobilization and remained at the elevated level during immobilization. Plasma level of glucose increased gradually and reached maximum and significance 45 min after the start of immobilization, then decreased. Fifteen min after immobilization, acetylcholine release increased again, while concentrations of epinephrine and norepinephrine were still elevated. Thus the response of acetylcholine and the other responses to immobilization stress were not parallel.

Acetylcholine↗
PubMed1996

Simultaneous expression of cadherin-11 in signet-ring cell carcinoma and stromal cells of diffuse-type gastric cancer.

We examined the expression of cadherin-11, a type II cadherin, in normal human tissues, cell lines and gastric cancer surgical specimens. Cadherin-11 was expressed widely in adult tissues, except the liver. It was expressed in fibroblast, mesothelial cell lines, and in only two signet ring cell carcinomas out of 16 various cancer cell lines. Cadherin-11 expression was detected in both signet ring cell carcinoma cells and surrounding fibroblasts of surgical specimens by in situ hybridization. These results suggest that cadherin-11 may play a role in the formation of diffuse-type gastric cancer through cancer-stromal interactions.

Adult↗
PubMed1996

Expression pattern of messenger RNAs for prostanoid receptors in glial cell cultures.

Expression level of messenger RNAs (mRNAs) for prostanoid EP3, FP, and TP receptors was investigated in cultured rat astrocytes, oligodendrocytes, and microglia, as well as in meningeal fibroblasts, rat glioma C6 cells, rat pheochromocytoma PC12 cells, whole brain, and several peripheral tissues by reverse transcriptase-polymerase chain reaction. Cultured astrocytes and oligodendrocytes expressed mRNAs for 3 prostanoid receptors examined. In contrast, cultured microglia and pheochromocytoma PC12 cells expressed EP3 and TP receptor mRNAs, but not FP receptor mRNA. Glioma C6 cells expressed only TP receptor mRNA among 3 prostanoid receptors with the same expression level as that in astrocytes. Cultured meningeal fibroblasts expressed 3 receptor transcripts, and their expression levels were lower than those in astrocytes. Expression level of mRNA for each prostanoid receptor in cultured glial cells was higher than that in whole brain. These observations suggest that each prostanoid has its specific roles in each glial cell type of the brain.

Animals↗
PubMed1996

Starvation reduces norepinephrine activities in both hypothalamus and heart in rats.

Norepinephrine (NE) activities in both hypothalamus and heart were simultaneously assessed in rats after food-deprivation for 2 days. The technique of gas chromatography-mass spectrometry was employed for the analysis of NE and its primary neuronal metabolite, 3,4-dehydroxyphenylethylene glycol (DHPG), and the ratio of DHPG to NE was used as an index of NE activity. Hypothalamic DHPG/NE ratio was significantly decreased by fasting and was completely reversed by a single day of refeeding. These changes in hypothalamic DHPG/NE ratio were parallel to those in cardiac DHPG/NE ratio. Supporting the concept in which hypothalamic NE neurons play an important role in modulating the sympathetic outflow, it is suggested the decrease in hypothalamic NE activity contributes to the reduction in cardiac NE activity during fasting.

Analysis of Variance↗
PubMed1996

Negligible synergistic effect of beta2-glycoprotein I on the reactivity of antioxidized low-density lipoprotein antibody to oxidized low-density lipoprotein.

We conducted this study to investigate whether antioxidized low-density lipoprotein (a-oxLDL) is an antibody to cryptic and/or neo-antigen on beta2-glycoprotein I (GPI), which is introduced by binding to anionic phospholipid, similar to that of GPI-dependent anticardiolipin antibody (aCL) employing a-oxLDL ELISA. We found that no significant optical density differences existed among systemic lupus erythematosus patients, including cases with aCL and/or lupus anticoagulant positivity, before and after the addition of GPI. Our results suggest that a-oxLDL is not an antibody to denatured GPI, but rather to oxLDL.

Autoantibodies↗
PubMed1996

Buffer may be the critical factor in measurement of anti-prothrombin antibody on a gamma-ray-irradiated plate by enzyme-linked immunosorbent assay.

We investigated the influence of different buffers (Tris-buffer and phosphate buffered saline (PBS)/Tween-20 buffer) on anti-prothrombin antibody (aPT) measurement by enzyme-linked immunosorbent assay (ELISA), employing a gamma-ray-irradiated plate. We found considerable discrepancies in aPT positivity between each buffer, and we suggest that the use of Tris-buffer is not suitable for aPT measurement with a gamma-ray-irradiated plate to measure aPT.

Autoantibodies↗
PubMed1996

Inactivation of p16INK4 in hepatocellular carcinoma.

We analyzed the p16INK4 status of 6 hepatocellular carcinoma (HCC) cell lines and 32 primary HCC tumors, including 9 early-stage tumors, to determine whether p16INK4 tumor-suppressor gene inactivation participates in hepatocarcinogenesis. p16INK4 was studied at its protein level through Western blotting, at its messenger RNA (mRNA) level through reverse-transcriptase polymerase chain reaction analysis (RT-PCR) and Northern blotting, and at its genomic level through Southern blotting and PCR-single-strand conformation polymorphism analysis. The p16 protein was absent from 3 of 6 cell lines (50%) and 11 of 32 primary tumors (34%), but present in noncancerous tissues, indicating that p16INK4 is involved in hepatocarcinogenesis. Furthermore, we suggest that the p16 protein loss may contribute to the following: (1) early-stage hepatocarcinogenesis, because it was observed in 22% of early stage tumors; and (2) tumor progression, because it occurred approximately twice as often in advanced rather than in early stage tumors (40%). It was striking that neither p16INK4 homozygous deletion and mutation nor loss of p16INK4 mRNA expression were observed in HCC cell lines and primary tumors, including those specimens from which the p16 protein was absent except the Li7HM cell line, in which p16INK4 mRNA was not detected. These results suggest that p16INK4 in HCC is inactivated predominantly by posttranscriptional regulation rather than by genomic aberrations and lack of transcription.

Base Sequence↗
PubMed1996

Plasma hepatocyte growth factor levels are increased in systemic inflammatory response syndrome.

Interleukin-1 (IL-1), a cytokine released from macrophages by endotoxin stimulation, has been shown to upregulate the genetic expression of the hepatocyte growth factor (HGF). The present study was conducted to determine whether plasma HGF is increased in patients with systemic inflammatory response syndrome (SIRS). The plasma levels of HGF, endotoxin, and beta-glucan were measured in 41 surgical patients without hepatic diseases, 18 of whom had been diagnosed with sepsis, and 33, with nonseptic SIRS. The plasma HGF was found to be significantly increased in the 18 patients with sepsis, at 0.69 +/- 0.47 ng/ml (mean +/- SD), and in the 23 patients with nonseptic SIRS, at 0.49 +/- 0.37 ng/ml, compared to values in 40 normal controls, at 0.10 +/- 0.03 ng/ml (P < 0.001). No significant correlations were observed between the plasma levels of HGF and endotoxin (r = 0.02) or beta-glucan (r = -0.05) in any of the patients; however, plasma HGF was significantly correlated with the WBC count (r = 0.34, P < 0.05) and with total bilirubin (r = 0.45, P < 0.01). Plasma HGF was also strongly correlated with alanine transaminase (ALT) in 8 patients with ALT levels higher than 50 U/l (r = 0.70), but there was no such correlation in 33 patients with ALT levels of 50 U/l or less (r = 0.30). Thus, although the clinicopathologic significance of HGF is not well understood, the present findings indicate that plasma HGF increases in response to infection or inflammation.

Digestive System Neoplasms↗
PubMed1996

The relationship between brain surface elastance and brain reexpansion after evacuation of chronic subdural hematoma.

BACKGROUND: Brain stiffness has been thought to be a factor affecting brain re-expansion after the evacuation of chronic subdural hematoma. METHODS: As an index of brain stiffness, the pressure for compressing the brain using an ophthalmodynamometer was defined as brain-surface elastance. This elastance in 14 patients was measured and analyzed in relation to brain re-expansion. RESULTS: Patients with an enlarged subdural space on computed tomography 1 month after the operation had higher elastance. There was a correlation between high elastance and high age. CONCLUSIONS: Measuring the elastance after evacuation of the hematoma may help predict the persistence of a subdural space.

Aged↗
PubMed1996

Calpain activation in plasma membrane bleb formation during tert-butyl hydroperoxide-induced rat hepatocyte injury.

BACKGROUND & AIMS: The mechanism of plasma membrane blebbing (dissociation of the lipid bilayer from the membrane cytoskeleton) in hepatocyte injury is not known. The aim of this study was to investigate the role of calpain, a calcium-dependent cytosolic protease, in bleb formation induced by oxidative stress. METHODS: Hepatocytes from Wistar rats were injured with tertbutyl hydroperoxide in the presence or absence of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or a specific calpain inhibitor, calpeptin (Z-Leu-nLeu-H). Bleb formation was examined by phase-contrast and transmission electron microscopies. Intracellular calcium concentration was measured using Fura-2. Western blot analyses were performed for cytoskeletal proteins (talin, alpha-actinin, and vinculin) and the intermediate (activated) and proactivated forms of calpain mu. RESULTS: tert-Butyl hydroperoxide induced a sustained increase in intracellular calciu, bleb formation, and, ultimately, hepatocyte death. Talin and alpha-actinin were degraded in a time-dependent manner, although no apparent changes of actin filament were observed. Before the cytoskeletal protein degradation, the intermediate form of calpain mu appeared as its proactivated form decreased. In addition, calpeptin or EGTA inhibited not only calpain mu activation but also cytoskeletal protein degradation and bleb formation. CONCLUSIONS: In tert-butyl hydroperoxide-treated hepatocytes, the activation of calpain promotes membrane blebbing via degradation of cytoskeletal proteins.

Animals↗
PubMed1996

Phosphatidyl serine-dependent antiprothrombin antibody is exclusive to patients with lupus anticoagulant.

We conducted this study to determine whether antiprothrombin antibody (aPT) [to prothrombin (PT) alone or PT/phosphatidyl serine (PS) complex] actually existed in patients with lupus anticoagulant (LA) and/or anticardiolipin antibody (aCL). aPT to PT alone was positive in 2/7 LA-positive (29%) and 3/7 LA/aCL-positive (43%) patients. aPT to PT/PS complex was positive in 4/7 LA-positive (57%) and 4/7 LA/aCL-positive (57%) patients in the presence of Ca2+. However, none of the aCL-positive patients without LA or the LA/aCL-negative patients were positive for aPT and aPT/PS. Thus, we confirmed the existence of aPT and aPT/PS specifically among LA-positive patients. However, the clinicopathological significance of aPT and aPT/PS in this clinical setting is yet to be clarified.

Antibodies, Anticardiolipin↗
PubMed1996

Determination of the presence of interleukin-6 in bile after orthotopic liver transplantation. Its role in the diagnosis of acute rejection.

OBJECTIVE: The authors evaluated the significance of interleukin-6 (IL-6) in bile in the diagnosis of acute rejection after liver transplantation. SUMMARY BACKGROUND DATA: Interleukin-6 in blood has not been shown to be useful as a marker of acute rejection in clinical liver transplantation. In a rat liver transplantation model, the authors have found that bile IL-6 levels correlated well with the severity of rejection as determined histologically, whereas kinetics of serum IL-6 differed among rats without any definite feature related to graft rejection. METHODS: Fifty-one patients who underwent orthotopic liver transplantation between May 1990 and February 1991 at the University of California, Los Angeles, were included in the study. After liver transplantation, bile and blood were collected daily, and IL-6 levels were measured by the enzyme-linked immunosorbent assay. RESULTS: Bile IL-6 increased to 1228 +/- 317 pg/mL on the day of transplantation and decreased to 50 pg/mL or less within 48 hours. Patients who had uneventful postoperative courses had low levels of bile IL-6 throughout their hospitalization. In patients with acute rejection, bile IL-6 significantly increased (1090 +/- 990 pg/mL; p<0.05), but decreased in response to antirejection therapy. In patients who had liver dysfunction due to ischemic change or sepsis, bile IL-6 did not increase. Patients with cholangitis had significantly increased levels of bile IL-6 (146 +/- 47; p<0.05). Interleukin-6 in blood increased with many kinds of complications other than rejection and seemed to be less specific than that in bile. CONCLUSIONS: Measurement of IL-6 in bile may be a useful, noninvasive tool for diagnosing acute rejection.

Acute Disease↗