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K Satoh

Publications and source records attributed to K Satoh.

At least 379 records · Page 21Linked to original sources

A carbon-centered radical as a reaction species in the DNA strand-breakage by D-glucosamine.

Electron spin resonance(ESR) studies using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and sodium 3,5-dibromo-4-nitrosobenzensulfonate (DBNBS) as a spin-trapping agent revealed the formation of both hydroxyl and carbon-centered radical-derived spin adducts in Cu2+-containing 50 mM Tris-HCl buffered solutions (pH 7.1) of D-glucosamine, D-mannosamine, and D-galactosamine, which were previously shown to have the ability to break the single-strand of plasmid pBR322 DNA in a nucleotide sequence-specific manner. HCl-free D-glucosamine has higher DNA breaking activity, and this activity is promoted more by the presence of Cu2+ than the original D-glucosamine hydrochloride, exhibits stronger radical signals in the ESR spectrum. It is suggested that D-glucosamine is unstable around neutral pH, being converted into certain intermediate(s) such as a dihydropyrazine compound, which generate(s) carbon-centered radicals, and that, besides the hydroxyl radical, the intermediate(s) is/are responsible for DNA strand breakage.

Benzenesulfonates↗

Carbonyl reductase purified from rabbit liver is not the product of a carbonyl reductase gene (RCBR5 or RCBR6) cloned from the rabbit liver cDNA library.

Six peptides were obtained by the digestion of carbonyl reductase purified from rabbit liver. The amino acid sequences of the six peptides were virtually identical to the corresponding regions in amino acid sequences deduced from two cloned carbonyl reductase genes (RCBR5 and RCBR6). However, there was a difference of one amino acid residue between the sequences of peptides from the purified enzyme and the corresponding region in the amino acid sequences deduced from the two cDNAs. The purified carbonyl reductase was confirmed to exhibit no reactivity towards menadione, even though the transient expression of the two cDNA for rabbit liver carbonyl reductase has been reported to cause a marked increase of menadione reductase activity in COS7 cells. The enzyme purified from rabbit liver was inactivated by thiol-specific reagents, 5,5'-dithiobis(2-nitrobenzoic acid) and sodium tetrathionate, suggesting that menadione probably interacts with the functional cysteine residue(s), and cannot serve as a substrate of the purified enzyme. Based on these results, it is concluded that the carbonyl reductase purified from rabbit liver is not the product of cloned carbonyl reductase gene (RCBR5 or RCBR6).

Alcohol Oxidoreductases↗

Effects of azelnidipine, a dihydropyridine calcium antagonist, on myocardial stunning in dogs.

Effects of azelnidipine, a dihydropyridine derivative, on stunned myocardium were examined in anesthetized open-chest dogs. The left anterior descending (LAD) coronary artery was ligated for 20 min and then released for 60 min. Dimethyl sulfoxide (DMSO), the solvent of azelnidipine, or azelnidipine (0.03, 0.1 or 0.3 mg/kg) was injected i.v. 20 min before ligation. Segment shortening was determined by sonomicrometry. The levels of high-energy phosphate were measured in 60-min reperfused hearts. Azelnidipine at 0.1 and 0.3 mg/kg significantly decreased diastolic blood pressure and increased % segment shortening. The increase in % segment shortening due to azelnidipine appeared to be abolished by propranolol and atropine pretreatment. Ischemia significantly decreased % segment shortening in all groups. The % segment shortening that had been decreased by ischemia recovered during reperfusion, but did not reach its preischemic level in each group. In the 0.1 and 0.3 mg/kg of azelnidipine-treated dogs, a significant enhancement of % segment shortening recovery during reperfusion was observed, as compared with that in the DMSO-treated dogs. Azelnidipine did not affect the high-energy phosphate levels in 60-min reperfused hearts. In conclusion, azelnidipine improved the contractile dysfunction in stunned myocardium, without any preservation of high-energy phosphate.

Animals↗

Exogenous recombinant human IL-12 augments MHC class I antigen expression on human cancer cells in vitro.

We investigated whether expressions of MHC class I and class II antigens relevant to tumor antigen presentation were changed on human tumor cells cultured with or without recombinant human IL-12(rhIL-12). We showed that the expression of MHC class I antigen on UTC-8, 28-1Cl and SBC-3 cells was augmented when these cancer cells were cultured with rhIL-12. The expression of class II antigen was slightly raised on UTC-8 and 28-1Cl cells by rhIL-12, but not enhanced on SBC-3 cells. These results suggest that rhIL-12 may provide possible enhancement of immunologic tumor recognition, and cytotoxic activity of lymphocytes against tumors through the enhanced expression of MHC class I antigen.

Carcinoma, Squamous Cell↗

Erythroid accelerating factor detected in serum from rats with drug induced hemolysis.

We have previously observed that an erythroid enhancing activity presents in rat serum in the early stage of drug induced hemolytic anemia. The further studies on biological and physicochemical aspects of this erythroid accelerating factor (EAF) is described in this paper. Hemolytic anemia was induced in rats by single intraperitoneal injection of acetylphenylhydrazine (APH) and serum was obtained from the rats on day 1 after APH injection. It was first fractionated by ultrafiltration on Amicon Diaflo membranes to give a series of fractions lying in the following ranges of molecular weight: 10-30 kDa, 30-50 kDa, 50-100 kDa, and >100 kDa. Among those fractions, largest increase in the number of colony forming unit erythroid CFU-E) colonies was shown in the fraction of >100 kDa that was subsequently fractionated by fast protein liquid chromatography (FPLC) system. EAF activity for CFU-E proliferation was detected in a FPLC fraction corresponding to a molecular weight of about 160 kDa. An addition of EAF significantly increased with dose dependent manner in the number of CFU-E colonies from rat bone marrow mononuclear cells. EAF alone had no burst promoting activity and exhibited no distinct activity to proliferate burst forming unit-erythroid even when interleukin-3 (IL-3) and high concentration (2 U/ml) of erythropoietin (Epo) were added together to the culture. The stimulating effect of EAF on CFU-E was markedly dependent on the presence of adherent cells in the culture. Partially purified protein was relatively heat-unstable (60% at 75 degrees C, 30 minutes) and sensitive to treatment with trypsin and alpha-galactosidase. These results suggest that EAF is a novel factor, possible glycoprotein to reinforce Epo function and is different from various cytokines previously documented because of differences of approximate molecular weight.

Animals↗

The usefulness of 99mTc-Technegas scintigraphy for diagnosing pulmonary impairment caused by pulmonary emphysema.

X-ray computed tomography (CT) has been used for diagnosis of pulmonary emphysema because it can reveal the morphology of low attenuation areas. Recently, 99mTc-Technegas imaging, one of several types of scintigraphic techniques, has been used for ventilation scintigraphy. Technegas scintigraphy was performed on 15 patients with pulmonary emphysema, and we compared the extent and degree of abnormal findings on Technegas scintigraphy with the extent of low attenuation areas shown by CT. We classified the findings of Technegas imaging into three grades, from mild to severe, according to the extent of peripheral irregularity and central hot spot formation. We also classified the findings of CT as centrilobular emphysema into three grades from mild to severe according to the extent of low attention areas in the peripheral lung fields. In 5 cases, CT and Technegas assessment resulted in equivalent diagnoses. In eight cases, Technegas images showed more detailed findings than CT images. In the two remaining cases, which were diagnosed as panlobular emphysema on CT, Technegas images showed the severe stage. Technegas scintigraphy was useful for diagnostic assessment of pulmonary emphysema, especially for panlobular emphysema, which is difficult to distinguish from the normal lung condition by CT assessment.

Adult↗

Studies of repeated administration of FK-506 on myocardial metabolism in rats.

The effect of a 14-day administration of FK-506 at 1 or 3 mg/kg on plasma lipids and myocardial energy and glucose metabolism in rats was investigated. FK-506 increased the level of blood glucose in rats when given daily at an oral dosage of 3 mg/kg for 14 days. The plasma level of total cholesterol was significantly increased by FK-506 at either 1 or 3 mg/kg, whereas that of triglyceride was not changed. There was no significant difference in energy charge potential and the lactate/pyruvate ratio of the myocardial tissue between FK-506- and solvent-treated groups. Because FK-506 administration for 14 consecutive days did not disturb myocardial energy and glucose metabolism, its cardiotoxic side effects were not recognized in the present experimental toxicological evaluation of rats.

Animals↗

[Probability of leaving cancer tissue unresected by limited operation in patients with peripheral, stage I non-small cell lung cancer].

To study the probability of leaving metastatic lymph nodes or intralobar metastasis unresected by limited surgery, we reviewed histopathologically 189 patients who had major pulmonary resection and complete lymph adenectomy for peripheral, p-T 1 or T 2 non-small cell lung cancer from 1975 to 1997 at our hospital. Lymph node involvements and or intralobar metastasis were found in 25 (26.0%) of 96 cases with tumor smaller than 3.0 cm and 44 (47.3%) of 93 cases with tumor larger than 3.0 cm. There was no difference between histological types of lung cancer. From this result, it was suggested that the risk of leaving cancer by limited operation would not be low. In conclusion, we believe that limited operation is not an alternative to the standard resection in patients with peripheral, stage I non-small cell lung cancer.

Aged↗

[A 49-year-old man with progressive bulbar palsy and respiratory failure].

We report a 49-year-old man with progressive bulbar palsy and respiratory failure. He was well until his 48 years of the age (December 1994) when he noted a difficulty in speaking in loud voice. In February, 1995, he noted regurgitation of foods to his nose and difficulty in his speech. He was admitted to our service in May 29, 1995. On admission, he was alert and oriented to all spheres and he was not demented. His higher cerebral functions were normal. In cranial nerves, he showed dysarthria and dysphagia; muscle atrophies were seen in the tongue, the bilateral sternocleidomastoid, supraspinatus, and infraspinatus muscles. Fasciculations were seen in these muscles. He showed no muscle weakness in his limbs except for the upper limb girdle muscles, no ataxia, no reflex abnormalities, nor sensory changes. EMG showed neurogenic changes in the affected muscles. MRI of the brain and the spinal cord was entirely normal. He was discharged for out patient follow-up, however, in October of 1995, he noted difficulty in swallowing solid foods. Gastrostomy was placed and he was discharged to his home. In February 11th of 1996, he was found unresponsive and brought into the ER of our hospital. On admission, he was comatose without spontaneous respiration. BP could not be obtained. He was immediately intubated and artificial ventilation was started. On the following morning, he became alert and he was not demented. He continued to show marked dysarthria and dysphagia; again no weakness was noted in the distal parts of the upper and lower extremities. Laboratory examination showed increase in serum CK to 2,173 IU/L and amylase to 2,032 IU/L. He was extubated on February 15th, however, his spontaneous respiration was not suffice to maintain his blood gas. According to his will, he was not placed on respirator and he died on February 24th, 1996. The patient was discussed in a neurological CPC and the chief discussant arrived at the conclusion that the patient had ALS. Although no upper neuron signs were observed clinically, it is not uncommon to see degeneration in the corticospinal tract in post-mortem examination. The question was what might have been the cause of increase in CK and amylase. Many participants thought that they were secondary to multiple organ failure due to prolonged hypoxic state at his last admission; other possibilities raised included acute myocardial infarction and acute bowel necrosis. Post-mortem examination revealed muscle atrophy in the facial, lingual, cervical, intercostal, and the upper limb girdle areas. The lungs were unremarkable except for old organized pneumonic foci in the right middle and lower lobes. Marked to moderate congestion was seen in many internal organs, however, no other gross abnormality was found. It was thought that respiratory palsy itself was the direct cause of his agonal event. In the spinal cord, the anterior horns showed various degree of neuronal loss and gliosis. No clear evidence of pyramidal tract degeneration was seen at the light microscope level. Lower brain stem motor neurons were markedly reduced. But no Bunina body was found. The substantia nigra showed moderate degree of neuronal loss and extraneuronal neuromelanins. The locus coeruleus showed similar but milder changes. The degree of nigral degeneration appeared to be well beyond those which could be seen in usual ALS patients. The question was whether or not this patient might have been in an early stage of the extended form of ALS.

Amyotrophic Lateral Sclerosis↗

Comparative study of technetium-99m-sestamibi and thallium-201 SPECT in predicting chemotherapeutic response in small cell lung cancer.

UNLABELLED: The purpose of this study was to evaluate the relationship between 99mTc-sestamibi (MIBI) accumulation by tumor and response to chemotherapy in small cell lung cancer patients compared with 201TI-chloride. METHODS: There were 19 patients with small cell lung cancer just before chemotherapy initiation. The patients were classified by a follow-up CT into complete remission, partial remission and no change groups. All patients underwent dual-isotope imaging with 201TI-chloride and 99mTc-MIBI. Regions of interest were placed over the tumors and contralateral normal lung tissue on one coronal view with a clearly defined lesion, and the tumor-to-normal (T/N) ratio and retention index were calculated. RESULTS: Early and delayed T/N ratios for 99mTc-MIBI in complete remission and partial remission groups were significantly higher (p < 0.05) than in the no change group. There was no significant correlation between T/N ratio and tumor response using 201TI-chloride. There were no significant differences in the retention index with respect to the tumor response in both 201TI-chloride and 99mTc-MIBI SPECT images. CONCLUSION: Technetium-99m-MIBI SPECT may be more effective than 201TI-chloride SPECT for evaluating response to chemotherapy in patients with small cell lung cancer.

Adult↗

[Gamma-knife radiosurgery for metastatic brain tumors from primary lung cancer].

Forty patients with metastatic brain tumors from primary lung cancer underwent radiosurgery (gamma-knife). We retrospectively compared their prior treatment history number of metastatic foci, and performance status, to evaluate the effects of, and indications for, gamma-knife therapy. After both the primary and the metastatic tumors were controlled, performance status could be used as an index in the choice of gamma-knife therapy. Our results demonstrate that repeated gamma-knife radiosurgeries prolonged survival time. Gamma-knife radiosurgery improves quality of life and prognosis of patients with metastatic brain tumors.

Adult↗

A mutation in plasma platelet-activating factor acetylhydrolase (Val279Phe) is a genetic risk factor for cerebral hemorrhage but not for hypertension.

Platelet-activating factor (PAF) acetylhydrolase is an enzyme that inactivates PAF. Deficiency of this enzyme is caused by a missense mutation in the gene. We previously found a higher prevalence of this mutation in patients with ischemic stroke. This fact suggests that the mutation might enhance the risk for stroke through its association with hypertension. We have addressed this hypothesis by analyzing the prevalence of the mutation in hypertension. We studied 138 patients with essential hypertension, 99 patients with brain hemorrhage, and 270 healthy controls. Genomic DNA was analyzed for the mutant allele by the polymerase-chain reaction. The prevalence of the mutation was 29.3% (27.4% heterozygotes and 1.9% homozygotes) in controls and 36.2% in hypertensives and the difference was not significant. The prevalence in patients with brain hemorrhage was significantly higher than the control: 32.6% heterozygotes and 6.1% homozygotes (p <0.05). PAF acetylhydrolase deficiency may be a genetic risk factor for vascular diseases.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

[MRI phase contrast flow measurement of portal vein: influence and compensation of respiratory motion and propriety of phase correction using background].

The purposes of this study were to (1) determine which condition, breath holding (BH) or quiet breathing (QB), is better for phase contrast (PC) measurement of the portal flow (PF); (2) assess the usefulness of respiratory compensation (RC), a technique that diminishes motion artifacts due to breathing, on PC flow measurement; and (3) evaluate the propriety of phase correction (PhC) using background for PC flow measurement. For purposes (1) and (2) respiratory simulation phantom (RSP) was measured, and PF measurements were performed in 6 healthy subjects (HS) and 53 patients. Thirty of the patients had liver cirrhosis (LC) and 23 did not. For purpose (3), flow measurements were carried out in the phantom and 6 HS. (1) In 6 HS, intra-subjective coefficients of variation (CV) were smaller under QB than under BH (p < 0.05). And PF in patients with LC was less than in those not under QB (p < 0.01). This difference was not statistically significant under BH. (2) In the RSP study PC flow measurement with high sort RC showed good reliability. (3) Intraobserver variation was smaller without PhC than with PhC (p < 0.05) in the HS study. It may be more useful to perform portal flow measurements under QB with RC and without PhC than with PhC or under BH.

Adult↗

[Typing of DNA using the primer extension preamplification (PEP) method--studies of reliability of typing and detection limits].

Primer extension preamplification (PEP), which can amplify sequence-independently a limited quantity of DNA as a whole, allows multiple DNA analyses by polymerase chain reaction (PCR). This technique may be applicable to forensic cases, especially in cases where only small amounts of DNA are available. To define the accuracy and sensitivity of PEP, the DNA typing results of nine loci (TH01, MCT118, HLA-DQ alpha, amelogenin, LDLR, GYPA, HBGG, D7S8, GC) by PCR with PEP (PEP-PCR) were compared with those by PCR without PEP. Both results were identical to each other for each sample tested. Furthermore, amplification of an initial genomic DNA by PEP was found to range from 15 to 600 times of the initial quantity and the efficiency of PEP may depend on the sequences flanking the loci tested. These results indicate that PEP can increase typing potential of PCR from forensic samples.

DNA↗

A follow-up study of atrophic gastritis and intestinal metaplasia after eradication of Helicobacter pylori.

BACKGROUND: Opinions differ as to whether atrophic gastritis and intestinal metaplasia (IM) improve after Helicobacter pylori eradication. We investigated the change of the severity of atrophy and IM after H. pylori eradication. MATERIALS AND METHODS: Twenty H. pylori-positive patients with histologically confirmed atrophic gastritis received anti-H. pylori therapy and achieved eradication. They were followed for 12-33 months (median 17 months) after the therapy. Biopsies were taken from the lesser and greater curvatures of the mid-antrum and middle body, and the incisura angularis of the stomach. The state of H. pylori infection was assessed histologically (Giemsa stain). Histological severity of atrophy and IM was graded according to the Updated Sydney System and scored on a 0-3 scale. The scores of atrophy and IM were compared between before and after the therapy (at the end of follow-up). RESULTS: No significant difference was found in the scores of antral or body atrophy between before and after the therapy. Scores of antral IM increased after the therapy, whereas those of body IM did not change significantly. Development of IM in the whole stomach was found in three of seven patients who had no IM before the therapy. All of them were male smokers and drinkers. In contrast, complete regression of IM was not found. CONCLUSIONS: Our results cast doubt on the reversibility of atrophy and IM after H. pylori eradication. Development of IM could be found in some of patients with atrophy even after H. pylori eradication.

Adult↗

[Elimination of artifacts in MRCP: technical consideration].

Artifacts of MR cholangiopancreatography (MRCP) include fluid-filled gastrointestinal tracts, respiratory motion artifacts, spasm of Oddi's sphincter, vascular compression of bile ducts, overlapping of various anatomical structures and bright signal of surrounding fatty tissue. In this article, various technical considerations to eliminate these artifacts were described for the better imaging analysis of MRCP. The use of high-concentration ferric ammonium citrate (Ferriseltz) is recommended to reduce bright signal of fluid-filled gastrointestinal tracts. In case of long breathhold sequences, O2-inhalation study is useful to eliminate respiratory motion artifacts. Careful attention should be paid to the spasm of Oddi's sphincter and the vascular compression of bile ducts to avoid erroneous interpretation of MRCP findings.

Arteries↗