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M Arai

Publications and source records attributed to M Arai.

At least 253 records · Page 14Linked to original sources

[Wernicke's encephalopathy developed several years after total gastrectomy. Report of 2 cases].

We present here 2 cases of Wernicke's encephalopathy developed several years after total gastrectomy. Case 1. A 48-year-old male developed impaired recent memory and unsteady gait. He had undergone total gastrectomy for advanced gastric cancer 5 years previously; he had been on tegafur regimen for 4 and a half years. He had had 630 ml of beer every day for 6 months until admission. On admission, there were bilateral abducens palsy, horizontal nystagmus, gait ataxia, and areflexia. Cranial MR imaging was unremarkable. After intravenous infusion of vitamin B1, the patient improved. Case 2. A 56-year-old male developed exertional dyspnea, memory loss, and unsteady gait. He had undergone total gastrectomy for a large submucosal tumor 4 years previously; he had had 300-500 ml of sake almost every day thereafter. Examination revealed bilateral abducens palsy, severe gait ataxia, and areflexia. Chest CT scans demonstrated moderate amount of pericardial effusion. Blood vitamin B1 level was abnormally low. After administration of vitamin B1, he improved. Both patients had had alcoholic drinks; laboratory findings demonstrated no liver dysfunction. Drinking alcohol, even in relatively small quantities, could precipitate the development of Wernicke's encephalopathy in gastrectomized individuals. Our 2 cases stress the importance of supplementary vitamin B1 administration after total gastrectomy.

Gastrectomy↗

Concentration of levofloxacin in cervical mucus and its clinical effects on cervicitis.

An investigation was made on the concentration of levofloxacin (LVFX) in cervical mucus and its clinical effects on cervicitis. The results were as follows: 1) The concentrations of orally administered LVFX in the cervical mucus of 110 subjects were determined by HPLC. During 1-4 hour after the administration the mean concentration of LVFX in the cervical mucus reached a level of 2 micrograms/g, which was higher than the serum level. The transfer of LVFX to the cervical mucus was almost the same as that to other genital organs. 2) When LVFX was given to 102 patients at a dose of 100-200 mg, t.i.d for 4-5 days and the efficacy was evaluated with clinical improvement, the clinical efficacy rate of LVFX was 72/102 (70.6%). Significant bacteriological effects were observed in 70/73 (95.9%), especially, the disappearance rate of C. trachomatis was 18/18 (100%). 3) The administration LVFX did not cause any subjective or objective side effects and any abnormalities were not detected in the laboratory test done in this study. These results demonstrate that LVFX can be sufficiently transferred to the cervical mucus for the treatment of cervicitis due to the infection of C. trachomatis etc.

Adult↗

Blood coagulation in the hepatic sinusoids as a contributing factor in liver injury following orthotopic liver transplantation in the rat.

Blood coagulation equilibrium in the hepatic sinusoids may be deranged after orthotopic liver transplantation, since tissue factor activity increases in Kupffer cells and thrombomodulin expression disappears in sinusoidal endothelial cells in orthotopically transplanted rat liver. The presence of sinusoidal blood coagulopathy and its contribution to the development of early graft failure following orthotopic liver transplantation were investigated in rats. Orthotopic liver transplantation was performed using livers preserved in cold UW solution, according to the method of Kamada, in rats. Abnormalities in the hepatic sinusoids were evaluated electron-microscopically. Anticoagulation therapy was done using antithrombin III concentrate infused immediately and 12 hr after operation. Fibrin deposition and endothelial cell destruction in the hepatic sinusoids were observed in transplanted rats 5 hr after operation. In these rats, plasma antithrombin III activity was decreased to less than 40%o of normal levels, and massive hepatic necrosis developed with increased plasma thrombin-antithrombin III complex concentration 24 hr after operation. Anticoagulation therapy significantly attenuated the extent of hepatic necrosis, with normalization of plasma antithrombin III activity and further increase in plasma thrombin-antithrombin III complex concentration. A hypercoagulative state exists after orthotopic liver transplantation in rats. Fibrin deposition in the hepatic sinusoids associated with this state may contribute to the development of early graft injury.

Animals↗

Import into mitochondria of phospholipid hydroperoxide glutathione peroxidase requires a leader sequence.

An in vitro import system was used to characterize the mechanism of import of phospholipid hydroperoxide glutathione peroxidase (PHGPx) into mitochondria. Mitochondria were isolated from rat liver and incubated at 25 degrees C with [35S]methionine-labeled products of the in vitro translation of mRNA that encoded 23-kDa and 20-kDa PHGPx. 23-kDa PHGPx was imported into mitochondria in a time-dependent manner and was processed to yield the 20-kDa form of PHGPx. The 20-kDa form of PHGPx, without a leader sequence, associated weakly with mitochondria but was not imported. An analysis with an uncoupler of oxidative phosphorylation showed that a membrane potential in the mitochondria was also required for the import of PHGPx. It appears, therefore, that the leader sequence in the precursor to PHGPx is the signal for import into the mitochondria. This is the first report to indicate that the precursor to PHGPx is imported into the mitochondria via the action of a leader sequence.

Animals↗

Cloning and sequencing of the cDNA encoding beta-glucosidase 1 from Aspergillus aculeatus.

A cDNA was isolated from an Aspergillus aculeatus cDNA library using synthetic oligodeoxyribonucleotide mixtures that corresponded to the internal amino acid (aa) sequence of mature beta-glucosidase 1 (BGL1). Analysis of the nucleotide sequence of the cloned cDNA insert revealed a 2580-bp open reading frame (ORF) that encoded a 860-aa protein. The deduced aa sequence of the ORF shared sequence similarity with several BGL from other microorganisms.

Amino Acid Sequence↗

Overexpression of phospholipid hydroperoxide glutathione peroxidase suppressed cell death due to oxidative damage in rat basophile leukemia cells (RBL-2H3).

The role of phospholipid hydroperoxide glutathione peroxidase (PHGPx) in the cellular defense against oxidative stress was investigated in a novel cell model. We isolated stable transfectants of RBL-2H3 cells that overexpressed PHGPx. The activity of PHGPx in RBL2H3 cells that had been transfected with the 761bp cDNA for rat PHGPx (RPHGPx2) that we had cloned previously was 3.8 times higher than that in parent cells and in cells that had been mock-transfected with the vector without a cDNA insert. Cells that overexpressed PHGPx were three times more resistant than parent cells and mock-transfected cells to the cytotoxic effects of an radical initiator (AAPH) that induced the oxidative stress. This resistance to damage by AAPH of cells that overexpressed PHGPx was not observed after pretreatment with buthionine sulfoximine (BSO), an inhibitor of the synthesis of glutathione. Overexpression of PHGPx could suppress the peroxidation of membrane lipids and, in particular, the production of phosphatidylcholine hydroperoxide by AAPH in RBL2H3 cells. PHGPx was also able to prevent cell death in response to extracellular attack by a lipid peroxide. This is the first report to indicate directly that PHGPx can scavenge phosphatidylcholine hydroperoxide, which induces oxidative damage at the cellular level.

Amidines↗

Syntheses of 1-O-carboxyalkyl GLA-60 analogues.

As part of our ongoing study to survey potent LPS antagonists, the following six compounds were synthesized in an efficient manner: 3-carboxypropyl and carboxymethyl 2-deoxy-2-(2,2-difluorotetradecanamido)-4-O-phosphono-3-O-[(R)-3- (tetradecanoyloxy)tetradecanoyl]-alpha- and beta-D-glucopyranosides (11 and 23; 32 and 36), as well as the non-fluorinated equivalents, carboxymethyl 2-deoxy-4-O-phosphono-2-tetradecanamido-3-O-[(R)-3-(tetradecano yloxy)- tetradecanoyl]-alpha-D-glucopyranoside (44) and carboxymethyl 2-deoxy-2-[(R)-3-(hydroxy)tetradecanamido]-4-O-phosphono-3-O-[(R)- 3- (tetradecanoyloxy)tetradecanoyl]-alpha-D-glucopyranoside (48). Of these compounds, 32 was most pronounced in terms of LPS-antagonistic activity.

Carbohydrate Conformation↗

Cloning of a cluster of chitinase genes from Aeromonas sp. No. 10S-24.

A gene encoding chitinases from Aeromonas sp. No. 10S-24 was cloned into Escherichia coli DH5 alpha using pUC19, and its nucleotides were sequenced. The chitinase gene was clustered in ORFs (open reading frame) 1 to 4, in a 8-kb fragment of DNA. ORF-1 consisted of 1608 bp encoding 535 amino acid residues, and ORF-2 consisted of 1425 bp encoding 474 amino acid residues. ORF-3 was 1617 bp long and encodes a protein consisting of 538 amino acids. ORF-4 encodes 287 amino acids of the N-terminal region. The amino acid sequences of ORF-1 and ORF-3 share sequence homology with chitinase D from Bacillus circulans, and chitinase A and B from Streptomyces lividans. The amino acid sequence of ORF-2 shared sequence homology with chitinase II from Aeromonas sp. No. 10S-24, and chitinase from Saccharopolyspora erythraea. A region of the sequence starting from Ala-28 of the amino acid sequence of ORF-3 coincided with the N-terminal amino acid sequence of chitinase III from Aeromonas sp. No. 10S-24.

Aeromonas↗

Monocytic differentiation modulates apoptotic response to cytotoxic anti-Fas antibody and tumor necrosis factor alpha in human monoblast U937 cells.

Interferon-gamma (IFN-gamma), vitamin D3 (VD), and retinoic acid (RA) induce differentiation of human monoblastic leukemia U937 cells to macrophage-like cells with potential superoxide anion-generating activity upon further stimulation. Here we report that U937 cells thus differentiated show various responses to apoptotic induction with a cytotoxic anti-Fas antibody and tumor necrosis factor (TNF). VD-or RA-treated U937 cells acquired resistance against Fas- or TNF receptor (TNFR)-mediated apoptosis, whereas apoptotic cell death was accelerated in IFN-gamma-treated cells. By flow cytometric analyses, no decrease in expression of surface Fas antigen or p55 TNFR was observed in differentiated U937 cells. Cell surface expression of CD11b was seen only when differentiation was induced with VD or RA but not with IFN-gamma. The growth of VD- or RA-treated cells was retarded but IFN-gamma-treated cells were prolific. These findings suggest that the differentiation state differs with the inducer and that the cellular response to apoptotic induction is closely related to the state including the cell cycle.

Antigen-Antibody Reactions↗

Sarcoplasmic reticulum genes are upregulated in mild cardiac hypertrophy but downregulated in severe cardiac hypertrophy induced by pressure overload.

Changes in contractile and relaxation properties of heart muscle in the cardiac hypertrophy induced by pressure overload have been attributed to alterations in intracellular Ca2+ transport as well as the phenotypic and quantitative changes in contractile protein. However, contradictory data have been reported regarding Ca2+ uptake, release and storage by the sarcoplasmic reticulum (SR). The purpose of this study was to evaluate the changes in SR Ca(2+)-ATPase, ryanodine receptor, calsequestrin and alpha-actin gene expression, and the changes in Ca2+ uptake capacity in various degrees of hypertrophied hearts due to pressure overload. Cardiac hypertrophy was produced in rats by placing a constricting clip (0.80 mm) around the suprarenal abdominal aorta for 8 days. The mRNA levels and Ca2+ uptake capacity were then measured as a function of the severity of cardiac hypertrophy. Ca(2+)-ATPase and ryanodine receptor mRNA levels were increased in mildly hypertrophied hearts but were diminished in severely hypertrophied hearts, showing a bimodal response to pressure overload, Ca2+ uptake capacity showed similar changes along with a positive correlation with Ca(2+)-ATPase mRNA level (r = 0.67, P < 0.001). In contrast, the level of calsequestrin mRNA expression was unaltered and that of alpha-actin was markedly increased over a range of severity of cardiac hypertrophy. These findings suggest that the expression of sarcoplasmic reticulum genes for Ca2+ uptake and release is up- or downregulated dependent on the degree of pressure overload. The gene for the SR Ca2+ storage protein, calsequestrin, might be under different control from these genes in pressure overload. Our findings suggest that the decrease in ratio of mRNAs encoding Ca2+ uptake and release proteins to those encoding contractile proteins could significantly contribute to the slowed contractile and relaxation properties seen in pressure-overloaded hearts.

Actins↗

Rebamipide protects against activation of neutrophils by Helicobacter pylori.

Our objectives were to determine whether rebamipide, a unique antiulcer agent, would inhibit adhesive reactions between neutrophils and endothelial cells as well as the production of active oxygen species from neutrophils elicited by an extract of H. pylori. A water extract of H. pylori that was prepared from biopsy materials obtained from a patient with gastric ulcer increased the surface expression of CD18 on human neutrophils isolated from peripheral blood, the adhesion of neutrophil-endothelial cells, and the production of active oxygen species by neutrophils. Rebamipide, at concentrations of 10(-5) and 10(-6) M, reduced the adherence of neutrophils to endothelial cells as well as the CD18 expression on neutrophils induced by this bacterial extract. Rebamipide also inhibited the production of active oxygen species from neutrophils stimulated by H. pylori extract. These results suggest that rebamipide protects against the gastric mucosal inflammation associated with H. pylori by inhibiting neutrophil function.

Alanine↗

Changes in serum levels of metalloproteinases and their inhibitors by treatment of chronic hepatitis C with interferon.

We treated 18 patients with chronic hepatitis C by recombinant interferon-alpha (6 MIU for 24 weeks). In seven patients, serum aminotransferase levels declined to normal (responders). To evaluate the effect of interferon on matrix metalloproteinases (MMPs) and their inhibitors, namely tissue inhibitors of metalloproteinases (TIMPs), the serum levels of these enzymes were determined by enzyme immunoassay (EIA) using a specific monoclonal antibody. In responders, there was a tendency, but not a significant one, towards either an increase in serum MMP 1 levels or a decrease in serum TIMP 1 levels. In contrast, in nonresponders, both a significant decrease in MMP 1 and MMP 3 and a significant increase in TIMP 1 were observed. The number of cases of either increase in serum MMP levels or decreased in serum TIMP levels was significantly larger in responders than in nonresponders. Furthermore, the ratio of MMP 1 to TIMP 1 significantly increased in responders, suggesting that the balance between matrix formation and degradation in hepatic fibrosis tended to move toward degradation. These data indicate that interferon may exert a beneficial effect on hepatic fibrosis in parallel with improvement of aminotransferase activity.

Adult↗

Effect of a cholecystokinin receptor antagonist (loxiglumide) on gallbladder contractile function in guinea pigs.

We evaluated the effect of the specific cholecystokinin (CCK) receptor antagonist, loxiglumide, on gallbladder contractile function in guinea pigs. Five mg/kg body weight (BW) of loxiglumide was administered orally to guinea pigs once a day for 3 days. We then investigated gallbladder contractile function and plasma CCK concentrations in the guinea pigs. Maximal gallbladder pressure induced by cerulein was significantly depressed on the 1st and 3rd days following loxiglumide administration. On the 1st day, the plasma CCK concentration was significantly increased compared with that of the control group during fasting and 15 min after the administration of an intraduodenal test meal. These results suggest that the disturbed gallbladder contraction is due to the competitive inhibition of CCK by loxiglumide. Gallbladder contractile function in guinea pigs is depressed by loxiglumide; however, this effect is reversible after short-term loxiglumide administration.

Animals↗

Spatial frequency sweep pattern reversal VER acuity vs Snellen visual acuity: effect of optical defocus.

The effect of artificially induced image defocusing on visual acuities (VAs) measured by spatial frequency sweep pattern reversal visual evoked response (SPVER) and Snellen measurement was studied in six normal subjects. The steady-state SPVER was recorded using vertical gratings of 10 different spatial frequencies ranging from 0.52 to 30.36 c/deg. The SPVER acuity was compared with Snellen acuity (SA) measured under the same conditions of optical defocus. With moderate defocusing [< + 1.0 diopter (D), VA > 20/40], the SPVER acuities were equal to or poorer than the SAs. With more defocus (> + 1.5 D, VA < 20/70), the SPVER acuities became better than the SAs. The discrepancies between the SA and SPVER acuities may be the result of the influence of the parafoveal area on the SPVER at lower visual acuity levels.

Adult↗

An anti-CD18 antibody limits infarct size and preserves left ventricular function in dogs with ischemia and 48-hour reperfusion.

OBJECTIVES: This study investigated whether an antibody against neutrophil adhesion protein CD18 could limit myocardial infarct size and preserve left ventricular function after prolonged reperfusion in a canine model. BACKGROUND: Myocardial reperfusion injury is mediated in part by accumulation of activated neutrophils. Although antibodies against CD18 have been shown to reduce neutrophil influx and infarct size after ischemia and 3 to 4 h of reperfusion, it is unknown whether protection is sustained beyond this time or whether there is meaningful preservation of ventricular function. METHODS: Dogs undergoing 90-min circumflex coronary artery occlusion and 48-h reperfusion were randomized to receive 1 mg/kg bodyweight of R15.7 (an anti-CD18 antibody, n = 12) or saline (control, n =12) 10 min before reperfusion. Contrast left ventriculography was used to measure left ventricular ejection fraction and regional chord shortening at baseline, during occlusion and at 48 h. Microspheres injected during occlusion were used to measure collateral flow and risk region size. Postmortem infarct size was measured with triphenyltetrazolium chloride. RESULTS: In the dose administered, R15.7 bound to neutrophils in vivo, with >85% saturation of CD18 for >24 h, with sustained antibody excess in the plasma. R15.7 significantly reduced infarct size after adjusting for the effect of collateral flow (p = 0.0002, analysis of covariance). In a subgroup of dogs with collateral flow <30% of nonischemic flow, infarct size was reduced from 34.6 +/- 3.9% (mean +/- SE) of the region at risk in the control group to 19.5 +/- 3.3% in the antibody group (p = 0.008). Ejection fraction and regional chord shortening did not differ between the two groups at baseline or during occlusion, but after 48-h reperfusion, ejection fraction and inferior wall regional cord shortening (representing the infarct zone) were both higher in the R15.7 group than the control group (43.6 +/- 2.9% vs. 28.5 +/- 1.8%, p < 0.01; 2.55 +/- 0.29% vs. 1.06 +/- 0.18%, p < 0.05). CONCLUSIONS: A single injection of an anti-CD18 antibody given before reperfusion can limit myocardial infarct size by nearly 50% and preserve global and regional left ventricular function after 48 h of reperfusion.

Animals↗

Malignant hyperthermia during epidural anesthesia.

We anesthesized a patient susceptible to malignant hyperthermia (MH) three different times by epidural anesthesia with different types of local anesthetics. His skinned fiber test showed a marked acceleration of calcium (Ca2+)-induced Ca2+ release (CICR). When ester type local anesthetic was used for ankle contracture repair, MH signs appeared following the release of the tourniquet. CICR test is reliable for diagnosing different types of MH.

Adolescent↗

Rapid formation of a molten globule intermediate in refolding of alpha-lactalbumin.

BACKGROUND: The molten globule state is an intermediate between the native and the fully unfolded states of globular proteins and is purported to be an obligatory on-pathway intermediate of protein folding. The molten globule state of alpha-lactalbumin has been best characterized, but two major issues have yet to be clarified. At which stage of the kinetic refolding is the molten globule state stably organized? And what is the major driving force that stabilizes the molten globule state? We address these questions in this paper. RESULTS: We have investigated the refolding kinetics of alpha-lactalbumin using stopped-flow CD and fluorescence, acrylamide quenching and pulsed hydrogen exchange NMR techniques. A burst-phase intermediate was observed to form within 15 ms. The intermediate was characterized by pronounced, hydrogen-bonded secondary structure, exposure of hydrophobic surfaces and the absence of tertiary structure. Furthermore, the stability of the secondary structure is the same as that in the equilibrium molten globule state. CONCLUSIONS: The burst-phase intermediate in alpha-lactalbumin refolding is identical with the molten globule state. Two different models, the hydrophobic collapse model and the secondary-structure coalescence model, of protein folding are discussed on the basis of the present results. The importance of solvent-separated hydrophobic interactions that stabilize the molten globule state is proposed.

Animals↗