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Biomedical subjects

T Araki

Publications and source records attributed to T Araki.

At least 217 records · Page 12Linked to original sources
PubMed1999

Purification and characterization of beta-1,3-xylanase from a marine bacterium, Vibrio sp. XY-214.

beta-1,3-Xylanase was purified to gel electrophoretic homogeneity and 83-fold from a cell-free culture fluid of Vibrio sp. XY-214 by ammonium sulfate precipitation and successive chromatographies. The enzyme had a pl of 3.6 and a molecular mass of 52 kDa. The enzyme had the highest level of activity at pH 7.0 and 37 degrees C. The enzyme activity was completely inhibited by Cu2+, Hg2+, and N-bromosuccinimide. The enzyme hydrolyzed beta-1,3-xylan to produce mainly xylotriose and xylobiose but did not act on xylobiose, p-nitrophenyl-beta-D-xyloside, beta-1,4-xylan, beta-1,3-glucan, or carboxymethyl cellulose.

Amino Acid Sequence↗
PubMed1999

The amino acid sequence of wood duck lysozyme.

The amino acid sequence of wood duck (Aix sponsa) lysozyme was analyzed. Carboxymethylated lysozyme was digested with trypsin and the resulting peptides were sequenced. The established amino acid sequence had the highest similarity to duck III lysozyme with four amino acid substitutions, and had eighteen amino acid substitutions from chicken lysozyme. The valine at position 75 was newly detected in chicken-type lysozymes. In the active site, Tyr34 and Glu57 were found at subsites F and D, respectively, when compared with chicken lysozyme.

Amino Acid Sequence↗
PubMed1999

Prenatal diagnosis of autosomal recessive polycystic kidney disease. A case report.

We present a case of autosomal recessive polycystic kidney disease diagnosed at 28 weeks' gestation by ultrasonographic examination and magnetic resonance imaging (MRI). The fetal kidneys were symmetrically enlarged and highly echogenic by ultrasonographic examination and showed high-signal intensity on T2-weighted images by MRI. Cystic lesions were recognized by neither examination. In addition, the pulsatility index of the fetal renal artery was normal. These findings suggest a high water content in the renal parenchyma with tiny cysts and normal blood flow in autosomal recessive polycystic kidney disease.

Adult↗
PubMed1999

Prenatal diagnosis of acute massive fetomaternal hemorrhage.

We present here 2 cases of acute and 2 cases of chronic massive fetomaternal hemorrhage. A sinusoidal fetal heart rate pattern may indicate chronic fetomaternal hemorrhage, but, when increased variability is observed in fetal monitoring, maternal hemoglobin F should be measured to exclude acute fetomaternal hemorrhage.

Acute Disease↗
PubMed1999

Characteristics of monochorionic-diamniotic growth-retarded twins during the third trimester.

The goal of this study was to assess the characteristics of monochorionic-diamniotic (MD) growth-retarded twin infants with twin-twin transfusion syndrome (TTTS) compared with those without TTTS during the third trimester. Retrospective analyses of the growth patterns and amniotic fluid volumes were performed on 5 MD twin pregnancies in which one or both twins showed growth retardation with TTTS, and the results weve compared with those without TTTS. Eighty-three percent of growth-retarded twin infants without TTTS in MD twin gestation showed an asymmetric growth pattern, while all TTTS cases showed a symmetric pattern (p < 0.05). Polyhydramnios of the co-twin was found in 80% of TTTS cases, while no polyhydramnios was found in patients without TTTS (p < 0.05). Assessment of growth patterns and amniotic fluid volume may be useful to exclude the possibility of TTTS in MD growth-retarded twin pregnancies during the third trimester.

Adult↗
PubMed1999

Effects of TU-199, a novel H+, K(+)-ATPase inhibitor, on gastric acid secretion and gastroduodenal ulcers in rats.

We studied the effects of TU-199, a novel H+, K(+)-ATPase inhibitor, on gastric acid secretion and gastroduodenal lesions in rats in comparison with those of omeprazole. TU-199 inhibited hog gastric H+, K(+)-ATPase activity and its potency was almost equal to that of omeprazole (IC50 = 6.2 and 4.2 microM, respectively). In vivo, TU-199 inhibited basal gastric acid secretion in pylorus-ligated rats in a dose-dependent manner (ED50 = 4.2 mg/kg p.o.). In gastric fistula rats. TU-199 (2.5 and 5 mg/kg i.d.) also inhibited gastric acid secretion stimulated by histamine, carbachol or tetragastrin. Furthermore, TU-199 prevented the formation of water-immersion restraint stress-, pylorus ligation- and indomethacin-induced gastric lesions, and mepirizole-induced duodenal ulcer in rats. These antisecretory and antiulcer effects of TU-199 were 2-4 times more potent than those of omeprazole. The results demonstrate that TU-199 potently inhibits the acid secretion and formation of ulcers in various experimental rat models via an inhibition of H+, K(+)-ATPase. These findings suggest that TU-199 may have a beneficial effect against peptic ulcer disease in humans.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

Perfusion MR imaging with a superparamagnetic iron oxide using T2-weighted and susceptibility-sensitive echoplanar sequences: evaluation of tumor vascularity in hepatocellular carcinoma.

OBJECTIVE: The study purpose was to examine the usefulness of perfusion echoplanar MR imaging with a superparamagnetic iron oxide (SHU-555A) for evaluating the vascularity of hepatocellular carcinomas. SUBJECTS AND METHODS: Twenty-two patients with 32 hepatocellular carcinomas underwent perfusion imaging with bolus injection (0.7-1.1 ml) of SHU-555A. Echoplanar sequences included multishot spin-echo (17 patients) and single-shot gradient-echo (five patients) imaging. Image acquisition was repeated every 30 sec for 3 min with the multishot spin-echo sequence and every 2 sec for 100 sec with the single-shot gradient-echo sequence. Lesion signal intensity versus time curves were created for quantitative analysis. RESULTS: Transient decreases in tumor signal intensity (28.8% with multishot spin-echo and 63.3% with the single-shot gradient-echo) were seen in the perfusion phase. These decreases in signal intensity were statistically significantly (p < .01) different for each histologic type of hepatocellular carcinoma (poorly differentiated, 43.3%; well differentiated, 18.4%; and moderately differentiated, 24.8%). After the perfusion phase, the tumor signal intensities rapidly recovered. The multishot spin-echo sequence could detect some signal changes even in lesions smaller than 1 cm. CONCLUSION: Hepatocellular carcinoma vascularity can be evaluated with perfusion echoplanar imaging with SHU-555A. Because of its excellent temporal resolution, the single-shot gradient-echo echoplanar sequence detects the transient signal decrease in most lesions. The high image quality of the multishot spin-echo echoplanar sequence allows evaluation of the vascularity of even very small lesions.

Aged↗
PubMed1999

Effect of beta-agonists on production of cytokines by activated T cells obtained from asthmatic patients and normal subjects.

Intracellular levels of cAMP were found to regulate T cell activity. We examined whether beta2-agonists altered cytokine production and cyclic adenosine monophosphate (cAMP) accumulation in concanavalin A (ConA)-activated peripheral T cells from asthmatic patients. Procaterol and isoproterenol weakly decreased the ConA-elicited interleukin (IL)-4 and IL-5 secretion; however, the inhibitory effect of procaterol on the ConA-induced IL-2 secretion was inferior to that of isoproterenol in normal controls and was little in asthmatics. The intracellular accumulation of cAMP by procaterol was not altered compared with that by isoproterenol. Results suggest that there is a qualitative difference between procaterol- and isoproterenol-induced cAMP accumulation in T cells.

Adrenergic beta-Agonists↗
PubMed1999

[An elderly case of idiopathic thrombocytopenic purpura associated with acute myocardial infarction].

We report a rare case of idiopathic thrombocytopenic purpura (ITP) associated with acute myocardial infarction (AMI). A 72-year-old woman with hypertension and hemorrhoids was admitted because of chest pain, severe anemia (RBC 340 x 10(4)/microliter, Hb 5.4 g/dl, Ht 21.7%) and thrombocytopenia (0.2 x 10(4)/microliter). AMI was diagnosed by electrocardiogram (ST elevation and negative T in V2-5), echocardiogram (hypokinesis in anteroseptal wall) and laboratory (CPK 470 U/l) findings and was treated with only blood transfusion. Chest pain disappeared the day after admission, and neither heart failure nor arrhythmia occurred. Based on bone marrow findings (hyperplasia of erythroblast and megakaryocyte), endoscopic (internal hemorrhoids) and laboratory (antiplatelet antibody positive, platelet associated IgG 257.8 ng/10(7) cells) findings, iron deficiency anemia and ITP were diagnosed. Anemia improved after blood transfusion, but thrombocytopenia (< 1.0 x 10(4)/microliter) without active bleeding continued after steroid and gamma-globulin therapy. At discharge, electrocardiogram showed a negative T in I, aVL and V2-5, and T1 and BMIPP myocardial scintigram showed defects in the anteroseptal and apical wall.

Aged↗
PubMed1999

[Two cases of interstitial cystitis complicated with migraine].

Two cases of interstitial cystitis complicated with migraine and atopic tendency are reported. In the bladder tissue of the two cases, mast cells were increased and in one case which was observed with immunohistochemical staining, most of the mast cells among muscle layers were chymase-positive mast cells. We considered that the degranulation of mast cells was related with the cause of interstitial cystitis and migraine.

Aged↗
PubMed1999

[Application of MR-guided intravascular procedures by passive tracking utilizing the magnetic susceptibility effect: a preliminary report].

In MR-guided intravascular procedures, the position of catheters must be confirmed on near-real-time MR images. One way of monitoring this is by passive tracking utilizing the magnetic susceptibility effect. A catheter with a stainless steel braid had suitable visibility when tracked by magnetic susceptibility on fast GRE images, although the direction of the static magnetic field affected the apparent width of the catheter. Passive tracking with a 1.5T MRI unit was performed in a patient at one image/2 seconds with fast GRE. The catheter could be introduced to the SMA and celiac artery from the aorta with passive tracking.

Animals↗
PubMed1999

[Evaluation of two-dimensional thick-slice MR DSA: preliminary study].

We have used two-dimensional contrast-enhanced MR angiography for a single thick slice and called it MR DSA. This technique realizes nearly subsecond scanning per image and is therefore superior to other types of contrast-enhanced MR angiography in temporal resolution. To determine the optimal parameters of this technique, we calculated SSR (the signal of brain to the signal of contrast agent ratio) in various settings. We also obtained MR DSA images of 26 cases. We believe that MR DSA may play a supportive role in conventional MR imaging or angiography, since its high temporal resolution is of value in the evaluation of cerebrovascular diseases.

Angiography, Digital Subtraction↗
PubMed1999

[Guillain-Barré syndrome with cerebellar symptoms and elevated serum anti-GD1b IgG antibody].

We reported a 46-year-old woman with Guillain-Barré syndrome (GBS) after suffering from common cold. She also had cerebellar symptoms; ataxic speech, poor finger-nose and heel-knee tests, dysmetria, dysdiadochokinesis, poor one foot standing, positive Mann's test, ataxic gait, and poor tandem gait without Romberg's sign, and sensory disturbance. We ruled out other diseases with cerebellar symptoms; for example, Wernicke encephalopathy, multiple sclerosis, cerebellar vascular disease and encephalitis in the brain stem and cerebellum. Anti-GD1bIgG antibody was elevated in her serum in the acute phase. She was treated with immuno-adsorption therapy (TR-350) in the acute phase. The antibody titer decreased with clinical improvement after immuno-adsorption therapy. The involvement of the anti-GD1bIgG antibody in the pathogenetic mechanism of peripheral neuropathy and cerebellar symptoms was suggested.

Autoantibodies↗
PubMed1999

Fetal brain death and Dandy-Walker malformation.

The diagnosis of brain death by Doppler ultrasonography and magnetic resonance imaging is reported in a fetus at 23 weeks' gestation. This is believed to be the first instance in which brain death has been shown in a premature fetus with a brain-stem anomaly.

Abortion, Spontaneous↗
PubMed1998

The choleretic effects of N-acetylglucosaminides, major urinary metabolites of ursodeoxycholic acid, in bile fistula rats.

We investigated the effects of three bile acids conjugated with N-acetylglucosamine, ursodeoxycholate N-acetylglucosaminide, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, on bile flow and biliary excretion of various markers in comparison with ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid in bile fistula rats. These bile acids were infused intravenously at a constant rate of 0.3 or 0.6 micromol/min/100 g b.w. for 2 h. All bile acids examined increased bile flow in a dose-dependent manner. In particular, ursodeoxycholate N-acetylglucosaminide has a longer-lasting effect after its infusion on bile flow than the other bile acids. Furthermore, these bile acids markedly increased biliary total bile acid excretion. At a higher dose level, the coefficient of determination (r2) between the biliary total bile acid excretion and bile flow for ursodeoxycholate N-acetylglucosaminide (r2 = 0.39) was lower than that for the other bile acids (r2 = 0.75-0.92). The ursodeoxycholate N-acetylglucosaminide, as well as tauroursodeoxycholic acid, glycoursodeoxycholic acid, tauroursodeoxycholate N-acetylglucosaminide and glycoursodeoxycholate N-acetylglucosaminide, was mostly excreted in an unchanged form in bile, whereas ursodeoxycholic acid was excreted as a conjugate with taurine. The three N-acetylglucosaminides as well as ursodeoxycholic acid, tauroursodeoxycholic acid and glycoursodeoxycholic acid significantly increased the biliary excretion of cholesterol, phospholipid, bilirubin and total Ca2+. In contrast, the N-acetylglucosaminides significantly decreased in biliary bicarbonate concentration, whereas ursodeoxycholic acid significantly increased biliary bicarbonate concentration. However, tauroursodeoxycholic acid and glycoursodeoxycholic acid did not significantly change the biliary bicarbonate concentration. The results indicate that N-acetylglucosaminides have a choleretic effect in bile fistula rats. Our present study also demonstrates that N-acetylglucosaminides, but not ursodeoxycholic acid, tauroursodeoxycholic acid or glycoursodeoxycholic acid, can significantly reduce the biliary bicarbonate concentration. Furthermore, our findings suggest that ursodeoxycholate N-acetylglucosaminide may partly exert a choleretic effect via mechanisms different from those of the other bile acids.

Animals↗