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Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 271 records · Page 15Linked to original sources
PubMed1999

Melatonin secretion rhythm disorders in patients with senile dementia of Alzheimer's type with disturbed sleep-waking.

BACKGROUND: There is growing evidence that the dysregulation of circadian rhythms may play an important role in irregular sleep-waking in demented elderly. In this study, we investigated daily variation of the pineal hormone melatonin, which has been reported to possess hypnogenic and synchronizing effects, in patients with senile dementia of Alzheimer's type. METHODS: Serum melatonin secretion rhythms in inpatients with senile dementia of Alzheimer's type (SDAT group, n = 10, average age = 75.7 years) with disturbed sleep-waking and nondemented elderly (ND group, n = 10, age = 78.3 years) without clinical sleep disorders in the same facility were monitored under a dim light condition without excessive physical exercise. RESULTS: The SDAT group showed a significantly higher degree of irregularities in actigraphically recorded rest-activity (R-A) rhythm during the 7-day baseline period compared with the ND group. The SDAT group simultaneously showed significantly reduced amplitude, larger variation of peak times, and diminished amount of total secretion in the melatonin secretion rhythm compared with the ND group. There were significantly positive correlations between the severity of R-A rhythm disorder and the reduced amplitude as well as diminished amount of total melatonin secretion. CONCLUSIONS: The SDAT patients with disturbed sleep-waking possessed melatonin secretion rhythm disorders that may play an important role in irregular sleep-waking in demented elderly.

Aged↗
PubMed1999

Quantitative differences in the active-site hydrophobicity of five human glutathione S-transferase isoenzymes: water-soluble carcinogen-selective properties of the neoplastic GSTP1-1 species.

The active-site (the H-site) hydrophobicity of five human glutathione S-transferases (GSTs) was analyzed by application of linear free energy relationships (LFERs) with a series of S-alkylated glutathione inhibitors, GS(CH2)n - 1CH3 (n = 1-14). Distinct linear reltionships were observed in the plots of log Ki (inhibition constant) vs n for the five forms, whereby the Kis varied by three to four orders of magnitude. Mean free enthalpy changes per methylene group (-Delta DeltaG degreess), a measure of H-site hydrophobicity, were in the order M1-1 (4.6 kJ/mol) > A1-1 (3. 9 kJ/mol) > A1-2 (3.8 kJ/mol) > A2-2 (2.8 kJ/mol) > P1-1 (1.6 kJ/mol). The quantitative differences may in part account for the extraordinary broad and overlapping substrate specificities of the Alpha-, Mu-, and Pi-class isoenzymes. In contrast to the Alpha and Mu classes being selective for strongly electrophilic compounds, the neoplastic P1-1 species was indicated to be selective for weakly electrophilic and water-soluble carcinogens such as acrolein and hydroxyalkenals.

Binding Sites↗
PubMed1999

Electron transfer between QA and QB in photosystem II is thermodynamically perturbed in phototolerant mutants of Synechocystis sp. PCC 6803.

Several random mutations have been generated in the psbA2 gene of Synechocystis sp. PCC 6803 [Narusaka, Y., Murakami, A., Saeki, J., Kobayashi, H., and Satoh, K. (1996) Plant Sci. 115, 261-266]. The phototolerant mutant (I6) carrying all the amino acid substitutions in the lumenal side of D1 protein (S322I, I326F, and F328S) and a site-directed mutant of the same phenotype (NDFS) substituted in the stromal side of the protein (N234D and F260S) were characterized by thermoluminescence measurements. We observed (1) no significant differences in their growth rates at either low or high light irradiance, (2) a downshifted B-band in the NDFS mutant, (3) an upshifted Q-band in the I6 mutant, and (4) a damped period four oscillation of thermoluminescence in the B-band of both mutants. By examining the possible implications of these results on the redox properties of the PS II components in the mutants, we concluded that equilibrium constants for sharing an electron between the primary (QA) and secondary acceptor plastoquinones (QB) are decreased in both mutants.

Amino Acid Sequence↗
PubMed1999

Mechanical advantage of area of origin for the external pterygoid muscle in two murid rodents, Apodemus speciosus and Clethrionomys rufocanus.

The actions of masticatory muscles in relation to transverse grinding, associated with forward masticatory movement of the mandible, were investigated by using a mechanical model in the two murid rodents, the Japanese field mouse (Apodemus speciosus: subfamily Murinae) and the gray red-backed vole (Clethrionomys rufocanus: subfamily Arvicolinae). Furthermore, statics of the masticatory system on a sagittal plane while chewing is taking place were also analyzed in these rodents. The inward grinding movements of hemimandibles are generated by the posterior temporalis and internal and external pterygoids in both species. In addition to these muscles, the anterior temporalis also moves the hemimandibles lingually in Apodemus speciosus. The area of origin of the external pterygoid seems more advantageous for transverse grinding in A. speciosus than in Clethrionomys rufocanus. On the basis of the static analysis, the anterodorsal area of origin of the external pterygoid to the upper second and third molars in Clethrionomys rufocanus appears to be an adaptive character to prevent the jaw joints from dislocation during occlusion at a posterior point on the elongated row of cheek teeth.

Animals↗
PubMed1999

Thymidine phosphorylase expression is predominantly observed in stroma of well-differentiated adenocarcinoma of endometrium and correlates with a frequency of vascular involvement.

Thymidine phosphorylase (dThdPase) expression was studied in 20 cases of well-differentiated endometrial carcinomas to examine the clinicopathological significance. Immunohistochemical study showed predominant dThdPase expression in tumor stroma. No expression was detected in coexisting normal endometrial stroma or stroma of endometriosis. Seven cases (35%) showed strong stain and 13 (65%) showed weak stain. Based on the strength of immunoreactivity, patients were grouped into two groups: group S (strong) and group W (weak). In group S, 5 (71%) showed vascular involvement whereas in group W, only 3 (23%) cases were positive, giving a significant difference in the frequency of vascular involvement between the two groups (P < 0.03, chi2 analysis). No correlation was found between dThdPase expression and myometrial invasion. Patients with vascular involvement resulted in poorer outcome (P < 0.003) whereas between group S and W, there showed no difference in survival (group S vs group W; P < 0.15). A multivariate analysis including stage, vascular involvement, and dThdPase stain as variables showed none as independent risk factors. However, univariate analysis showed that the presence of a vascular involvement was a risk factor for a shorter survival (relative risk = 6.277, 95% range = 1.2-32.6, P < 0. 03). It is concluded that expression of dThdPase in endometrial carcinoma is a marker of a desmoreaction and a risk factor for vascular invasion. Since vascular invasion is a risk factor for poor outcome, the significance of dThdPase expression in endometrial carcinoma requires further clinical evaluations.

Adenocarcinoma↗
PubMed1999

Accumulation of technetium-99m pertechnetate in a patient with metastases of thyroid carcinoma.

Accumulation of both Tc-99m pertechnetate and radioiodine upon scintigraphy in thyroid carcinoma and/or in its metastases is a rare occurrence. In this paper we describe a patient who was taken to surgery for left lobectomy of the thyroid with follicular adenocarcinoma and who had accumulation of both I-131 and Tc-99m pertechnetate in lung metastases. The accumulation of I-131 was less than that of Tc-99m pertechnetate. The use of Tc-99m pertechnetate for imaging for diagnosis of functioning thyroid metastases is discussed.

Adenocarcinoma, Follicular↗
PubMed1999

Tc-99m Technegas scintigraphy to evaluate the lung ventilation in patients with oral corticosteroid-dependent bronchial asthma.

Bronchial asthma is a clinical syndrome characterized by the reversibility of airway obstruction. Recently it has been suggested that remodeling of the airway causes irreversible airway obstruction which may be responsible for the patient's symptoms. With this background, the purpose of the present study was to assess patients with corticosteroid-dependent asthma by Tc-99m Technegas scintigraphy (Technegas) in both planar and SPECT images. Twelve patients (7 females and 5 males aged 36-72 years with a median age of 60 years: 4 smokers and 8 non-smokers) with oral corticosteroid-dependent asthma were enrolled in this study. Lung ventilation scanning with Technegas in both planar and SPECT images, high-resolution computed tomography, and pulmonary function tests were performed in all patients. The results of Technegas scanning were graded and correlations with other clinical parameters were evaluated. Significant abnormalities were detected by ventilation scintigraphy with Technegas in patients with corticosteroid-dependent bronchial asthma even during remission. Our data demonstrate that airflow obstruction took place in patients with corticosteroid-dependent asthma even during remission. Technegas scanning appears to be a useful radiopharmaceutical for demonstrating airflow obstruction in patients with bronchial asthma.

Adrenal Cortex Hormones↗
PubMed1999

Visualization of esophageal non-Hodgkin's lymphoma with Ga-67 scintigraphy.

Although non-Hodgkin's lymphoma of the gastrointestinal tract is common, primary esophageal lymphomas represent less than 1% of all gastrointestinal tumors. We report a case of primary non-Hodgkin's lymphoma of the esophagus. Ga-67 scintigraphy showed characteristic intense accumulation in the esophageal wall. The histopathology belonged to the category of mucosa-associated lymphoid tissue lymphoma.

Citrates↗
PubMed1999

Clonal expansion of gammadelta-T lymphocytes in an HTLV-I carrier, associated with chronic neutropenia and rheumatoid arthritis.

We report on an HTLV-I carrier showing clonal proliferation of gammadelta-T lymphocytes associated with chronic neutropenia and rheumatoid arthritis (RA). A 75-year-old Japanese woman had a 20-year history of RA and was found to have neutropenia and lymphocytosis by routine examinations. Her white cell count was 5,800/microl with 89% lymphocytes. The proliferating gammadelta-lymphocytes did not show the typical morphology of large granular lymphocytes (LGL) and were positive for CD3, TCRdelta1, and HLA-DR but negative for CD4, CD8, and deltaTCS1. Clonally rearranged TCRgamma-chain (Jgamma) and TCRbeta-chain (Cbeta1) genes were detected by Southern blot analysis. Clonality of these proliferating gammadelta-T cells was confirmed by CDR3 size analysis for the TCRdelta-chain. Anti-HTLV-I antibody was positive and the pX region of HTLV-I proviral DNA was detected by PCR analysis, but clonal integration of HTLV-I proviral DNA was not detected by Southern blotting analysis. The patient's clinical course has been stable, except for infrequent infectious episodes. The association of HTLV-I/II infection with T-LGL leukemia has been reported by several groups, although most cases exhibit TCRalphabeta+ type T cells. Analysis of the junctional sequence of TCR on T-LGL leukemia cells may clarify the role of HTLV-I/II infection in clonal T-cell proliferation.

Aged↗
PubMed1999

Effects of nitroglycerin on fractal features of short-term heart rate and blood pressure variability.

PURPOSE: We investigated the effect of nitroglycerin(NTG) on fractal features of short-term heart rate variability (HRV) and blood pressure variability (BPV) using coarse-graining spectral analysis (CGSA). METHOD: Nine healthy young volunteers participated in this study. Five-minute recordings of electrocardiogram and blood pressure estimated by photoplethysmograph were made during stepwise NTG infusions of 0.2, 0.4, 0.8, and 1.6 microg.kg(-1).min(-1) under rate-controlled breathing at 0.25 Hz. CGSA broke down the total power of the time series into harmonic (low- and high-frequency) and nonharmonic (beta of 1/f(beta) and %fractal) components. RESULTS: A statistically significant difference from the control period was observed during the maximum dose of NTG infusion, with decrease in mean blood pressure, shortening of mean R-R interval, and increase in plasma norepinephrine and epinephrine. The beta in HRV increased significantly (0.89 +/- 0.06 vs. 1.27 +/- 0.13, P < 0.05). However, %fractal was not affected (47.9 +/- 6.7 vs. 50.1 +/- 4.0). Indicators of parasympathetic and sympathetic nervous system activity showed reduced and increased values, respectively. No change in BPV was observed for any measurement. CONCLUSION: The data suggest that NTG significantly affected fractal features, as well as harmonic components, of short-term HRV. NTG had no effect on BPV, suggesting a different mechanism for genesis of 1/f(beta) fluctuation in BPV and HRV.

Journal Article↗
PubMed1999

Mechanical properties of several nickel-titanium alloy wires in three-point bending tests.

The purpose of this study was to clarify the mechanical properties of 42 brands of nickel-titanium alloy orthodontic wires from 9 manufacturers by conducting three-point bending tests under uniform testing conditions. Manufacturers included A-Company, Hoya Medical, Lancer, Ormco, Rocky Mountain, Sankin, Tomy (GAC), TP, and 3M/Unitek. Cobalt-chrome, and titanium-molybdenum alloy wires were also tested as a reference for comparison of force levels. All reported data were recorded during the unloading process to simulate the force that a wire exerts on a tooth as it is moved into the dental arch from a position of malocclusion. The following results were obtained for the nickel-titanium wires tested. (1) Among the 0.016 inch round wires tested under a maximum deflection of 1.5 mm, the difference between the smallest (Copper nickel-titanium 35) and the largest (Aline) load values was 136 g. For the 0.016 x 0.022 inch rectangular wires tested, the difference between the smallest (Copper nickel-titanium 40) and the largest (Aline) load values was 337 g. (2) The change in load between 1.5 and 0.5 mm of deflection was examined to clarify the superelastic properties of the wires tested. For the 0.016 inch wires, 17 wire brands produced a load difference of less than 100 g, and two brands produced a difference of at least 100 g (Aline and Titanal = 100 g). For the 0.016 x 0.022 inch wires, 15 brands produced a load difference of less than 100 g, and eight brands produced a difference of over 100 g. The smallest and largest load differences were 3 g (Copper nickel-titanium 35) and 200 g (Aline). (3) The majority of the samples with a smaller load difference between deflections of 1.5 mm and 0.5 mm in the unloading process were found among super-elastic wires, while samples with a larger load difference were predominantly found among work-hardened wires. Compared with cobalt-chrome and TMA wires, nickel-titanium alloy wires exert significantly less force. However, the amount of force varies greatly from brand to brand. Consequently, when using nickel-titanium alloy wires, brands must be selected carefully by taking into consideration the severity of the malocclusion and the stage of orthodontic treatment in each case. It is the intent of this study to offer clinicians an unbiased guide for the selection of appropriate nickel-titanium alloy wires.

Dental Alloys↗
PubMed1999

Stimulation of early embryonic development in cattle by coculture with surfactant.

PURPOSE: Our purpose was to determine the efficacy of Surfacten, a bovine pulmonary surfactant, on the maturation of in vitro bovine ova. METHODS: We used Surfacten as a supplement to the coculture media both at the onset of coculture and after cleavage in bovine ova had been determined. The controls received no Surfacten. RESULTS: The maturation rate in bovine embryos to the blastocyst stage statistically improved (P < 0.05) in the series in which Surfacten was added to the media at the onset of coculture, compared with the controls and the series in which Surfacten was added after cleavage had been determined. CONCLUSIONS: Surfacten, a commercially available surfactant which is a naturally occurring phospholipid that dramatically increases in the cervical mucus and the ampullaris of the oviduct at or near the time of ovulation, improves the maturation of bovine embryos in vitro by making the coculture medium approach the conditions found in the oviducts.

Animals↗
PubMed1999

Fimbrial capture of the ovum and tubal transport of the ovum in the rabbit, with emphasis on the effects of beta 2-adrenoreceptor stimulant and prostaglandin F2 alpha on the intraluminal pressures of the tubal ampullae.

PURPOSE: Our purpose was to elucidate the roles of the ampullar and isthmic portions of the oviduct and the effects of drugs on oviductal contractility. METHODS: Prostaglandin F2 alpha (PGF2 alpha; Ono Pharmaceuticals, Osaka) and oxytocin (Atonin-O; Teikoku Hormone Manufacturing Co. Ltd., Tokyo) were used to stimulate oviductal contractility, and ritodrine hydrochloride (Utemerin; Solvay-Duphar Corp., Denmark) to inhibit the contractility. RESULTS: Both PGF2 alpha and Atonin-O were involved in ovum capture by the ampullar oviduct by stimulating contractility, thus altering the intraductal pressures. Utemerin is effective in inhibiting the enhanced contractility induced by PGF2 alpha and Atonin-O. CONCLUSIONS: Variations in pressure of the ampullar portion of the oviduct seem necessary for the capture of ova expelled from the ovary. Once in the isthmic portion of the oviduct, transport appears to be under the influence of ciliary activity rather than variations in contractility.

Adrenergic beta-Agonists↗
PubMed1999

Interleukin-10 level in sputum is reduced in bronchial asthma, COPD and in smokers.

Interleukin (IL)-10 is a potent regulatory cytokine that decreases inflammatory responses. This study investigated whether IL-10 levels in the airway are decreased in chronic airway inflammation associated with asthma or chronic obstructive pulmonary disease (COPD). Sputum was obtained from 12 healthy nonsmokers, 10 healthy smokers, 16 asthmatic patients and seven patients with COPD by means of the sputum-induction method. The IL-10 level was measured via enzyme-linked immunosorbent assay and immunocytochemical analysis. The IL-10 level in sputum was significantly lower in asthma and COPD patients and healthy smokers compared with that in healthy nonsmokers (nonsmokers, 68.0+/-11.3; smokers, 45.3+/-7.8; asthma, 26.7+/-4.0; COPD, 18.0+/-2.3 pg x mL(-1); p<0.05 for nonsmokers versus the other groups). The percentage of IL-10-positive cells in the sputum was also significantly lower in asthma and COPD and in smokers (nonsmokers, 13.2+/-1.7; smokers, 6.4+/-1.8; asthma, 5.4+/-3.5; COPD, 3.5+/-1.6%; p<0.05 for nonsmokers versus the other groups). The IL-10-positive cell appeared morphologically to be the macrophage. These data suggest that the reduced level of interleukin-10 within the airways plays a role in the pathogenesis of chronic airway inflammation in asthma and chronic obstructive pulmonary disease.

Adult↗
PubMed1999

Sepsis attenuates the intensity of the neuromuscular blocking effect of d-tubocurarine and the antagonistic actions of neostigmine and edrophonium accompanying depression of muscle contractility of the diaphragm.

BACKGROUND: Prolonged effects of non-depolarizing muscle relaxants in septic patients have been reported, although the influence of sepsis on neuromuscular transmission has not yet been clarified satisfactorily. These studies were intended to elucidate the influence of sepsis on neuromuscular transmission and on the action of drugs being utilized for regulation of muscle tone (a neuromuscular blocker and anti-cholinesterase (anti-ChE) drugs). METHODS: The effect of d-tubocurarine (dTc) on neuromuscular transmission and the antagonistic action of anti-ChE drugs (neostigmine and edrophonium) on dTc-induced twitch depression were estimated using sham control and septic rat nerve-hemidiaphragm preparations in vitro. Isometric twitch tension elicited by indirect (phrenic nerve) or direct (muscle) stimulation at 0.1 Hz was evaluated. RESULTS: Sepsis induced by panperitonitis attenuated the twitch tension elicited by indirect or direct stimulation (P < 0.01) without obvious morphological inflammatory damage to the diaphragm. dTc dose-dependently decreased twitch tension elicited by indirect stimulation (P < 0.01) less intensely in the septic group than in the sham group (P < 0.01). The antagonistic actions of the anti-ChE drugs on dTc (1 microM)-induced twitch depression were less intense in the septic group (P < 0.01 or 0.05). CONCLUSION: These results demonstrate that sepsis in the acute phase attenuates the effects of a neuromuscular blocker and anti-ChE drugs and depresses muscle contractility simultaneously.

Animals↗
PubMed1999

Diminution of 37-kDa laminin binding protein expression reduces tumour formation of murine lung cancer cells.

Expression of the 37-kDa laminin binding protein (37LBP/p40), a precursor of the 67-kDa laminin receptor, is well-correlated with the biological aggressiveness of cancer cells. To elucidate the direct role played by 37LBP/p40 in cancer cells, a murine lung cancer cell line T11, the 37LBP/p40 expression of which was remarkably diminished, was established by the introduction of the antisense 37LBP/p40-RNA using a retroviral vector. As a result, the population doubling time of T11 was prolonged (60 h) compared with that of P29, the non-transfected parental cell line (42 h), and TN2, a transfectant with vehicle only (40 h). In-vitro studies also showed that T11 cells adhered to immobilized laminin less firmly than P29 cells did. When 5 x 10(5) cells were subcutaneously inoculated into syngenic mice, the mean survival time of T11-recipients (77.0+/-14.8 days) was also significantly prolonged compared with that for P29 (34.8+/-5.5 days) and TN2 (36.7+/-6.1 days) recipients (P < 0.001). The electron-microscopic view of the tumour tissue revealed that T11 cells were loosely apposed and their intercellular space was markedly widened. Some of the T11 cells sporadically degenerated with the infiltration of lymphocytes and neutrophils. These results suggest that the suppressed expression of 37LBP/p40 reduces the capability of lung cancer cell proliferation in vitro and tumour formation in vivo.

Animals↗