Biomedical subjects

T Satoh

Publications and source records attributed to T Satoh.

At least 451 records · Page 25Linked to original sources

PubMed1997

Overexpression in Escherichia coli of chemically synthesized gene for active 0.19 alpha-amylase inhibitor from wheat kernel.

A synthetic gene encoding 0.19 alpha-amylase inhibitor (alpha-AI) from wheat kernel was obtained by enzymatic assembly of 18 oligodeoxynucleotides which were chemically synthesized. The synthetic gene was introduced into vector pET15b for expression in Escherichia coli BL21(DE3) under the control of T7 promoter. However, in SDS-PAGE and Western blotting analyses of the E. coli cell lysate, the expression product could not be detected. Expression analysis for various partially deleted gene fragments suggested that the putative hairpin-like structure of mRNA in the 5'-terminal coding region might interrupt efficient expression. When the hairpin structure was eliminated by using degenerate codons, the resulting gene could be overexpressed in E. coli. Although the gene product was accumulated in an insoluble fraction as inclusion bodies, its inhibitory activity could be recovered by solubilization with 8 M urea, followed by refolding through two successive steps of dialysis at alkaline pH. After purification, the recombinant 0.19 alpha-AI showed the same characteristics as the authentic inhibitor in terms of N-terminal amino acid sequence, peptide mapping on reverse-phase HPLC, far-UV circular dichroism (CD) spectrum and have inhibition of human salivary alpha-amylase. Thus, we have established an overexpression system in E. coli for active recombinant 0.19 alpha-AI.

Amino Acid Sequence↗

PubMed1997

Impaired left ventricular myocardial metabolism in patients with pulmonary hypertension detected by radionuclide imaging.

To assess whether left ventricular myocardial metabolism is affected by the presence of right ventricular pressure overload, we performed 123I-beta-methyl-iodophenyl pentadecanoic acid (123I-BMIPP) and 99Tc(m)-sestamibi (99Tc(m)-MIBI) single photon emission tomography in 24 patients with pulmonary hypertension and in 10 control subjects. The left ventricle was divided into six regions using a short-axis tomogram at the mid-ventricular level. The relative regional uptake (RRU, %) was determined for each region as the ratio of the regional uptake per pixel to the maximum uptake in the six regions. Right heart catheterization was performed to obtain mean pulmonary arterial pressure. 123I-BMIPP uptake in the septum and the adjacent myocardium of the left ventricle was lower in patients with pulmonary hypertension than in control subjects (septal RRU, 75 +/- 6 vs 85 +/- 4%; anteroseptal RRU, 76 +/- 6 vs 86 +/- 3%; posteroseptal RRU, 75 +/- 4 vs 84 +/- 4%; P < 0.001). The reduction in 99Tc(m)-MIBI uptake was confined to the septum in patients with pulmonary hypertension (79 +/- 5 vs 85 +/- 5%; P < 0.05). Interestingly, the septal RRU of 123I-BMIPP and the sum of the septal, anteroseptal and posteroseptal RRUs of 123I-BMIPP were negatively correlated with mean pulmonary arterial pressure (r = -0.70 and -0.55, respectively; P < 0.01). In conclusion, myocardial metabolism in the interventricular septum and the adjacent regions of the left ventricle may be impaired in proportion to the degree of pulmonary hypertension.

Adult↗

PubMed1997

Minimum alveolar concentration of sevoflurane for tracheal extubation in children.

BACKGROUND: One advantage of tracheal extubation during deep anaesthesia is that respiratory complications are reduced. Sevoflurane is a suitable anaesthetic agent for children. This study was conducted to determine the minimum alveolar concentration of sevoflurane required to prevent cough or movement during and after tracheal extubation (MACextubation). METHODS: We studied 30 nonpremedicated children, aged 2-10 yr, undergoing plastic surgery. They were allocated randomly to five groups (end-tidal sevoflurane concentrations: 2.0, 2.5, 3.0, 3.5, 4.0%). After surgery, 60% nitrous oxide was discontinued and the target concentration of sevoflurane was maintained for at least 10 min in 100% oxygen, then the trachea was extubated to determine MACextubation. Logistic regression was used to estimate MACextubation of sevoflurane. RESULTS: MACextubation was 2.3 (0.2; standard error)% (95% confidence limits: 1.2% and 2.7%). CONCLUSIONS: Tracheal extubation in 50% of anaesthetized children age 2-10 yr may be accomplished without coughing or moving at 2.3% end-tidal concentration of sevoflurane.

Anesthetics, Inhalation↗

PubMed1997

A novel method to evaluate thromboresistance of drip chambers with filter used in extracorporeal blood circuits for hemodialysis.

We have developed a novel method to simultaneously evaluate thromboresistance of two different types of drip chambers with a filter used in extracorporeal blood circuits for hemodialysis using canine arteriovenous shunt models. Bilateral bypasses between the femoral artery and vein on both sides of the animal were formed with 2 test circuits consisting of polyvinyl chloride tubing and two types of drip chambers with filters. Blood flow was derived into the drip chambers with a filter and returned to the femoral vein without using peristaltic pumps and systemic anticoagulants. By monitoring the quantitative changes of the blood flow rate through each drip chamber with a filter and measuring the time elapsed before the blood flow through its was completely obstructed by clots, thromboresistance of the drip chambers was evaluated under the same blood conditions. The drip chamber with a filter that had a small effective filter area, a big pore size, and slitlike pores showed better thromboresistance. This novel method proved useful in evaluating the thromboresistance of differently designed drip chambers with a filter.

Animals↗

PubMed1997

Radiofrequency catheter ablation for AV nodal reentrant tachycardia associated with persistent left superior vena cava.

Slow AV nodal pathway ablation using RF is highly effective for patients with refractory AV nodal reentrant tachycardia (AVNRT). We report three catheter ablation cases using RF current in patients associated with persistent left superior vena cava (PLSVC). Three patients with drug refractory AVNRT of common variety were involved in this study. An electrode catheter introduced through the left subclavian vein inserted directly into the coronary sinus, a typical anatomical finding of PLSVC. The ablation procedure was initially performed at the posteroinferior region of Koch's triangle. A slow pathway potential could not be found from that area; nonsustained junctional tachycardia (NSJT) did not occur during the delivery of RF current; there was failure to eliminate slow AV nodal pathway conduction. The catheter then was moved into the bed of the proximal portion of the markedly enlarged coronary sinus. A slow AV nodal pathway potential was recorded through the ablation catheter, and the delivery of RF current caused NSJT in two patients. Complete elimination of slow AV nodal pathway conduction was accomplished in these two patients by this method. No adverse effects were provoked by this procedure. Catheter ablation of the slow AV nodal pathway guided by a slow pathway potential and the appearance of NSJT was feasible and safe in the area of the coronary sinus ostium in patients associated with PLSVC.

Adult↗

PubMed1997

Metallothionein expression and concentrations of copper and zinc are associated with tumor differentiation in hepatocellular carcinoma.

Metallothionein is the carrier protein of heavy metal ions, such as copper (Cu) and zinc (Zn). In this study, the relationships among immunohistochemical expression of metallothionein, concentrations of Cu and Zn, histological differentiation and proliferative activity of hepatocellular carcinoma were investigated in 51 cases. The concentrations of Cu and Zn in both tumor and non-tumor tissues were determined using electron probe microanalysis. Immunohistochemical expression of metallothionein in tumor tissues decreased with the degree of differentiation, whereas the number of hepatocytes positive for Ki-67 increased. Furthermore, the concentrations of Cu and Zn in tumor tissues decreased with the degree of histological differentiation in human hepatocellular carcinoma.

Biomarkers, Tumor↗

PubMed1997

[A case of primary HIV-1 infection].

A previously healthy 28 year old Japanese man came to us with a genital ulcer which appeared 13 days before admission to our hospital. He had subsequently fever (40 degrees C), arthralgia, a sore throat and oral aphtha 6 days before admission. He had a history of sexual contact with a female commercial sex worker one week before his illness. On the day of admission, he had shallow ulcers on the lip, tongue and penis. Initial laboratory test included leukopenia and thrombocytopenia. His fever abated 3 days after admission. His condition and bicytopenia recovered completely after 12 days of admission. Although, his serum HIV-1 antibody was negative when he was admitted, 3 months later the antibody was seroconverted. And p24 antigen and HIV-1 RNA of stocked serum were positive. Diagnosis of primary HIV-1 infection was made. Recently, HIV-1 infection has been increasing in Japan. Consideration of this disease in differential diagnosis of acute febrile illness is necessary.

Adult↗

PubMed1997

Polymorphonuclear cells in chronic hemodialysis patients have intact phagocytotic and impaired bactericidal activities.

Although it has been well documented that chronic hemodialysis (HD) patients are highly susceptible to infectious diseases, the reasons for this have yet to be clarified. The present study was thus designed in order to better define this issue. Fifty-eight stable chronic HD patients without any evidence of infection were selected for the study. Blood samples were collected before and after HD from the same patient to determine the effect of HD. Reactive oxygen species (ROS) production in polymorphonuclear cells (PMNC) was measured by chemiluminescence using luminol. When the PMNC collected after HD were stimulated in vitro with a calcium ionophore (A23187), they produced a larger amount of ROS than that obtained from healthy volunteers [mean 7.4 x 10(5) photon counts (n = 58) vs. 3.0 x 10(5) photon counts (n = 17); p < 0.01]. A higher production of ROS after HD was seen in patients using membranes such as cellulose triacetate, polymethylmetacrylate and cellulose diacetate, whereas cuprophane did not seem to augment ROS production at all. On the other hand, when the PMNC after HD were stimulated with phorbol myristate acetate, their photon counts (mean 4.3 x 10(7)) were comparable to those before HD (mean 3.5 x 10(7)), and to those of PBMC obtained from healthy volunteers (mean 4.1 x 10(7)). It was thus suggested that the enhanced ROS production of PMNC was related to some stimuli, possibly even to the assay used to measure ROS. The phagocytotic activity and bactericidal effect of PBMC were measured by coculturing 1 x 10(5) PMNC with 1 x 10(5) CFU of Escherichia coli. Similar phagocytotic activities were noted in the PMNC from healthy volunteers and chronic HD patients before and after HD: the mean number of phagocytosed bacteria (log10 CFU) was 3.3, 3.3, and 3.3, respectively. However, in the case of a bactericidal effect, only the PMNC from healthy volunteers, but not the PMNC from HD patients, could effectively kill the bacteria, since the number of bacteria in PMNC decreased from 10(3.3) to 10(2.1). The PMNC from HD patients could not kill the bacteria-regardless of the characteristics of the membranes. It was thus concluded that the PMNC of chronic HD patients possess an intact phagocytotic activity which impaired bacterial killing, and was probably due to an abnormality occurring in the ROS production pathway.

Adult↗

PubMed1997

Subcortical hypoperfusion associated with asymptomatic white matter lesions on magnetic resonance imaging.

BACKGROUND AND PURPOSE: We examined whether hemodynamic and metabolic abnormalities in the cerebral white matter, basal ganglia, and thalamus are associated with asymptomatic white matter lesions (WML) depicted on MR images. METHODS: A positron emission tomographic study with H2(15)O, C15O, and 15O2 was performed in eight normal control subjects without any WML (mean +/- 1 SD age, 68.5 +/- 10.2 years) and in 15 asymptomatic subjects with WML (71.3 +/- 8.5 years) to measure regional cerebral blood flow (CBF), cerebral blood volume, oxygen extraction fraction (OEF), and oxygen metabolic rate. RESULTS: In the cerebral white matter in the asymptomatic subjects with WML, significantly lower CBF (20.3 +/- 3.9 mL/100 mL per minute; P < .05) and significantly higher OEF (0.43 +/- 0.08; P < .05) were found compared with those for control subjects (23.5 +/- 2.6 mL/100 mL per minute and 0.37 +/- 0.06, respectively). The severity of WML was not related to the magnitude of hypoperfusion. In the basal ganglia, significantly lower CBF (44.9 +/- 6.9 mL/100 mL per minute; P < .01) and significantly higher OEF (0.54 +/- 0.08; P < .01) were found in the WML group than in control subjects (70.1 +/- 12.0 mL/100 mL/min and 0.39 +/- 0.03, respectively). In the thalamus, there was no significant difference in CBF and OEF between the control and WML groups. CONCLUSIONS: Hypoperfusion of the cerebral white matter and basal ganglia in asymptomatic WML subjects may be induced by the arteriosclerosis of long penetrating medullary arteries and lenticulostriate arteries but may not be directly related to the production of WML. The role of hypoperfusion in the production of WML and acceleration of its development remains to be elucidated.

Aged↗

PubMed1997

Xenon contrast CT-CBF measurements in high-intensity foci on T2-weighted MR images in centrum semiovale of asymptomatic individuals.

BACKGROUND AND PURPOSE: White matter lesions (WMLs) on T2-weighted MR images occurring in the centrum semiovale of normal individuals are a subject of great clinical interest. We therefore investigated regional cerebral blood flow (rCBF) of the centrum semiovale among neurologically normal individuals. METHODS: One hundred thirty-five neurologically normal subjects were divided into four grades of WML on the basis of their MR images. rCBF values in the centrum semiovale were measured by xenon contrast CT methods. RESULTS: Advanced age and associated hypertension were significant risk factors for higher grade WMLs. Centrum semiovale rCBF values on the left side were 24.27 +/- 2.60 mL.100 g-1.min-1 in grade 0, 23.52 +/- 2.78 in grade I, 19.35 +/- 2.81 in grade II, 15.82 +/- 2.05 in grade III, and 11.31 +/- 2.56 in grade IV. Differences were significant between grades (P < .005 between grade 0 and grades II, III, and IV; between grade II and grades III and IV; and between grades III and IV). Patients with hypertension had lower rCBF values than those without in grades 0, I, II, and III, with significant difference in grade I (P < .005). Age-matched studies between patients 61 to 70 years old confirmed a significant difference between WML grades. CONCLUSIONS: WMLs in centrum semiovale are associated with greater age, hypertension, and reduced rCBF values.

Adult↗

PubMed1997

Expression of thyrotropin-releasing hormone (TRH) receptor mRNA in somatotrophs in the rat anterior pituitary.

A response of growth hormone (GH) to thyrotropin-releasing hormone (TRH) is observed in lower mammals and patients with diseases such as a cromegaly, but not in normal subjects. We have previously demonstrated the existence of intact TRH receptor mRNA in GH-secreting adenoma. To examine whether intact somatotrophs in the anterior pituitary also express TRH receptor, we attempted to localize both TRHR mRNA and GH immunoreactivity simultaneously. In situ hybridization analysis revealed TRHR mRNAs specifically in the anterior pituitary, and 61.1% of the anterior pituitary cells expressed this transcript. Staining for GH and PRL on the same samples showed that the somatotrophs apparently expressed TRHR mRNA and approximately 62.3% and 30.9% of hybridization-positive cells were somatotorophs and mammotrophs, respectively. Moreover, TRHR mRNA level in the somatotrophs expressed as the number of silver grains per cell was equivalent to that in the mammotrophs. These findings demonstrated expression of the TRHR mRNA in somatotrophs in the rat anterior pituitary, and also showed that more than 50% of the TRHR mRNA detected in the anterior pituitary was derived from these cells.

Animals↗

PubMed1997

A novel transcript for the thyrotropin-releasing hormone receptor in human pituitary and pituitary tumors.

We measured the amounts of TRH receptor (TRHR) messenger ribonucleic acid (mRNA) in human normal pituitary and pituitary tumors and found a novel transcript of the TRHR gene. Competitive PCR revealed expression of the TRHR mRNA in all pituitary adenomas examined, and its level was variable and similar to that in the normal pituitary. When the C-terminal region was amplified by PCR, an additional short product was observed. Cloning and sequence analysis of this short fragment revealed that the deleted sequence corresponded exactly to the 5'-sequence of exon 3, indicating alternative splicing of the TRHR mRNA. This alternative splicing resulted in a frame shift, yielding a C-terminal truncated protein (HTRHR2) on translation. Expression analysis of HTRHR2 in Chinese hamster ovary cells showed no significant binding to [3HIMeTRH or response of intracellular calcium to TRH administration. However, the mRNA ratio of HTRHR2 vs. the wild type (HTRHR1) was significantly different among pituitary tumors. The highest ratio was observed in prolactinomas (30%), and almost no detectable expression was found in GH-producing tumors. These findings indicate that this novel transcript of the human TRH receptor gene is produced in a tumor-specific manner and may be a useful parameter for evaluation of individual pituitary tumors.

Adenoma↗

PubMed1997

Evaluation of propolis. I. Evaluation of Brazilian and Chinese propolis by enzymatic and physico-chemical methods.

To establish a method of evaluating propolis, the effects of the ethanol and water extracts from various collecting of propolis from different countries and plant sources on hyaluronidase activity were investigated along with their absorption spectra and specific absorbance (E(1%)1 cm value). The relations between the hyaluronidase inhibitory activities of these extracts and their E(1%)1 cm values were also examined, and the following was found: 1) the enzyme inhibitory activities of the ethanol extracts were more potent than those of the water extracts; 2) the enzyme inhibitory activities of the ethanol extracts from Araucaria angustifolia (BERT.) O. KTZE were low compared with those of other ethanol extracts; 3) the enzyme inhibitory activities of all the ethanol extracts correlated excellently with their E(1%)1 cm values, but in the water extracts, they decreased with increase in E(1%)1 cm values; 4) the water extracts of Chinese propolis from Hebei, Jiangsu, Sichuan and Zhejiang Provinces inhibited weakly compared with that from Brazilian and other Chinese propolis; 5) the shapes of absorption bands of the propolis extracts and the E(1%)1 cm values were approximately dependent on the place or the plant source from which propolis was collected. These experimental results indicated that, for the exact evaluation of propolis, the enzymatic method, measuring the hyaluronidase inhibitory activity, was superior to the physicochemical method.

Anti-Inflammatory Agents↗

PubMed1997

Enantioselective fluorination of organic molecules. I. Synthetic studies of the agents for electrophilic, enantioselective fluorination of carbanions.

In order to develop novel methods for electrophilic and enantioselective fluorination of active methine compounds, preliminary experiments were carried out. The N-tosyl derivative 5 obtained from D-phenylglycine was fluorinated with FClO3 or diluted F2 gas to give the N-fluoro-N-tosyl derivative 6. N-tosyl- or N-mesyl-(S)-alpha-phenethylamine 7 or 8 was subjected to FClO3 fluorination to produce the corresponding N-fluoro derivative, 10 or 11, respectively. Enantioselective fluorination of some methine compounds was attempted employing the above N-fluoro agents. Best result was obtained when 2-benzyl-1-tetralone/KHMDS was treated with 10 to produce the fluorinated tetralone 17 in 53% yield with enantiomeric excess (ee) of 48%.

Anions↗

PubMed1997

Effects of mechanical stimulation in measurement of thermal pain threshold.

The improved thermal dolorimeter developed by Fukumoto has made it easy to measure thermal pain thresholds, but mechanical stimulations may be included as the probe is pressed into the skin. In order to evaluate these effects of mechanical stimulation on the improved thermal dolorimeter, the pain threshold temperatures were measured by a probe pressed to the human skin surface with weighting loads from 0.5 to 2.5 kgf. The loads of 2.0-2.5 kgf felt invasive to 8 of the 12 subjects, i.e., they experienced pain and numbness. The threshold temperature of one of these subjects, who developed water blisters around load-added area on the skin after the experiments, exceeded 50 degrees C. The result that no significant difference could be found among the thresholds at the loads of over 2.0 kgf suggests the load of less than 2.0 kgf should be kept to execute proper experiments. In order to investigate other effects on thermal property by compressing, the blood flow was measured when the skin was compressed and three dimensional heat transfer simulations were conducted. The results of the simulations demonstrated that the temperatures of the heat source which were measurable in practice differed approximately 1 to 2 degrees C from the true thresholds. The velocity of heating is also increased and subjects will be given stronger feelings of heating.

Adult↗

PubMed1997

Patent ductus arteriosus with combined valvular disease at age 91.

This report describes a 91-year-old patient with patent ductus arteriosus (PDA) complicated by combined valvular disease (CVD) (aortic and mitral stenosis, and aortic, mitral, pulmonic and tricuspid regurgitation). This patient seems to be the oldest living female with PDA and CVD hitherto reported in the medical literature. The patient developed several bouts of congestive heart failure which were treated medically. She not only has survived without surgical management, but is still enjoying her life at age 91. The features of PDA in the elderly are reviewed.

Aged↗

PubMed1997

[A case of fulminant hepatitis caused by antiandrogen, flutamide in a patient with prostate cancer].

Luteinizing hormone-releasing hormone analogue, 3.6 mg goserelin acetate and flutamide, 375 mg per day were used to treat metastatic prostate cancer in a 66-year-old male. Marked increase in serum aminotransferases and total bilirubin levels was noted after 7 weeks of treatment. The enzyme levels returned to normal at 2 months following discontinuation of the treatment. Though incidences of severe hepatotoxicity are rare (0.003-0.18%), cases of flutamide-induced death have been reported. Careful monitoring of patients is mandatory while administering flutamide.

Aged↗

PubMed1997

The latest seroepidemiological pattern of hepatitis A in Japan.

Age-specific prevalence of anti-hepatitis A virus antibody (anti-HAV) was surveyed with 2,708 sera collected in 1994 in various areas of Japan. By age-group analyses, we found strong association of anti-HAV antibody with higher age group. The prevalence ratios of antibody in the groups of 30-34, 35-39, 40-44, 45-49, 50-54, 55-59, 60-64 and 65 years or older were 0, 4.2, 22.0, 44.8, 57.6, 76.4, 84.5 and 91.4%, respectively. Geometric mean titers of anti-HAV antibody in the positive age groups were approximately 6,000 mIU/ml. The seropositives among older population were ascribed to the infections more than 40 years ago and the high anti-HAV titers have been maintained since that time. In Japan, people younger than 40 years of age are extremely risky to HAV infection, since 99% have no antibody. Those in forties are also risky since two-thirds of them are seronegative. In Japan, an inactivated vaccine was licensed in 1994. Vaccination may be recommended for such high-risk groups as travelers going to endemic areas, patients who have received blood product medication and child-care staffs.

Adolescent↗