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101.
Ichioka S Minegishi M Iwasaka M Shibata M Nakatsuka T Ando J Ueno S 《Bioelectromagnetics》2003,24(6):380-386
High intensity static magnetic fields, when applied to the whole body of the anesthetized rat, have previously been reported to decrease skin temperature. The hypothesis of the present study was that in diamagnetic water, molecules in the air play significant roles in the mechanism of skin temperature decrease. We used a horizontal cylindrical superconducting magnet. The magnet produced 8 T at its center. A thermistor probe was inserted in a subcutaneous pocket of the anesthetized rats to measure skin temperature. Animals (n=10) were placed in an open plastic holder in which the ambient air was free to move in any direction (group I). Animals (n=10) were placed in a closed holder in which the air circulation toward the direction of weak magnetic field was restricted (group II). Each holder was connected to a hydrometer to measure humidity around the animal in the holder. The data acquisition phase consisted of a 5 min baseline interval, followed by inserting the animal together with the holder into the center of the magnet bore for a 5 min exposure and a 5 min postexposure period outside the bore. In group I, skin temperature and humidity around the animal significantly decreased during exposure, followed by recovery after exposure. In group II, skin temperature and humidity did not decrease during the measurement. The skin temperature decrease was closely related to the decrease in humidity around the body of the animal in the holder, and the changes were completely blocked by restricting the air circulation in the direction of the bore entrance. Possible mechanisms responsible for the decrease in skin temperature may be associated with magnetically induced movement of water vapor at the skin surface, leading to skin temperature decrease. 相似文献
102.
Sugiyama M Suzuki S Tonouchi N Yokozeki K 《Bioscience, biotechnology, and biochemistry》2003,67(12):2524-2532
Xylitol production from D-arabitol by the membrane and soluble fractions of Gluconobacter oxydans was investigated. Two proteins in the soluble fraction were found to have the ability to increase xylitol production. Both of these xylitol-increasing factors were purified, and on the basis of their NH(2)-terminal amino acid sequences the genes encoding both of the factors were cloned. Expression of the cloned genes in Escherichia coli showed that one of the xylitol-increasing factors is the bifunctional enzyme transaldolase/glucose-6-phosphate isomerase, and the other is ribulokinase. Using membrane and soluble fractions of G. oxydans, 3.8 g/l of xylitol were produced from 10 g/l D-arabitol after incubation for 40 h, and addition of purified recombinant transaldolase/glucose-6-phosphate isomerase or ribulokinase increased xylitol to 5.4 g/l respectively, confirming the identity of the xylitol-increasing factors. 相似文献
103.
Karita S Nakayama K Goto M Sakka K Kim WJ Ogawa S 《Bioscience, biotechnology, and biochemistry》2003,67(1):183-185
A cellulolytic and thermophilic anaerobe was isolated from soil. This bacterium made a halo on a roll-tube culture containing Avicel. Analysis of the PCR-based 16S rRNA gene sequence showed that the bacterium was closely related to Moorella thermoacetica. Scanning electron microscopy showed the bacterium is a rod and has no protuberant structure on the surface of cells growing on cellulose, suggesting that this strain is a non-cellulosomal cellulolytic bacterium. Carboxymethyl cellulase and xylanase activities were detected in the culture broth. A major fermentation product from ball-milled cellulose was acetate. This strain has a potential to convert cellulosic biomass to acetate, directly. 相似文献
104.
Masakazu Takahashi Shigeo Moriguchi Toshiko Minami Hiroyuki Suganuma Akira Shiota Yasuyuki Takenaka Fumito Tani Ryuzo Sasaki Masaaki Yoshikawa 《Letters in Peptide Science》1998,5(1):29-35
Albutensin A is an ileum-contracting peptide derived from serum albumin. The sequences of bovine, human and porcine albutensin A are ALKAWSVAR, AFKAWAVAR, and AFKAWSLAR, respectively. These albutensin A homologs all exhibited biphasic ileal contractions in the longitudinal strips of guinea pig ileum. The order of potency in the contraction was porcine > bovine > human homologs. The ileal contraction profiles were similar to those of oryzatensin and casoxin C, agonist peptides for complement C3a receptors derived from rice albumin and bovine -casein, respectively. All three homologs of albutensin A have homology with the COOH-terminal sequences of complements C3a and C5a, which are essential for their activities; porcine albutensin A showed the highest homology. Indeed, porcine albutensin A was confirmed to act through both C3a and C5a receptors by a radioreceptor assay and cross-desensitization in the ileal contraction. In addition, bovine and human homologs also showed affinity for both receptors. This study suggests that a bioactive peptide acting through both C3a and C5a receptors is released by the proteolytic cleavage of serum proteins other than complement components. 相似文献
105.
Entrainment, Instability, Quasi-periodicity, and Chaos in a Compound Neural Oscillator 总被引:2,自引:0,他引:2
We studied the dynamical behavior of a class of compound central pattern generator (CPG) models consisting of a simple neural network oscillator driven by both constant and periodic inputs of varying amplitudes, frequencies, and phases. We focused on a specific oscillator composed of two mutually inhibiting types of neuron (inspiratory and expiratory neurons) that may be considered as a minimal model of the mammalian respiratory rhythm generator. The simulation results demonstrated how a simple CPG model— with a minimum number of neurons and mild nonlinearities— may reproduce a host of complex dynamical behaviors under various periodic inputs. In particular, the network oscillated spontaneously only when both neurons received adequate and proportionate constant excitations. In the presence of a periodic source, the spontaneous rhythm was overriden by an entrained oscillation of varying forms depending on the nature of the source. Stable entrained oscillations were inducible by two types of inputs: (1) anti-phase periodic inputs with alternating agonist-antagonist drives to both neurons and (2) a single periodic drive to only one of the neurons. In-phase inputs, which exert periodic drives of similar magnitude and phase relationships to both neurons, resulted in varying disruptions of the entrained oscillations including magnitude attenuation, harmonic and phase distortions, and quasi-periodic interference. In the absence of significant phasic feedback, chaotic motion developed only when the CPG was driven by multiple periodic inputs. Apneic episodes with repetitive alternation of active (intrinsic oscillation) and inactive (cessation of oscillation) states developed when the network was driven by a moderate periodic input of low frequency. %and amplitudes of intermediate strength, Similar results were demonstrated in other, more complex oscillator models (that is, half-center oscillator and three-phase respiratory network model). These theoretical results may have important implications in elucidating the mechanisms of rhythmogenesis in the mature and developing respiratory CPG as well as other compound CPGs in mammalian and invertebrate nervous systems. 相似文献
106.
Junko Saito Takahiro Tabuchi Akira Shibanuma Junko Yasuoka Masakazu Nakamura Masamine Jimba 《PloS one》2015,10(10)
BackgroundExposure to second hand smoke (SHS) is one of the major causes of premature death and disease among children. While socioeconomic inequalities exist for adult smoking, such evidence is limited for SHS exposure in children. Thus, this study examined changes over time in socioeconomic inequalities in infants’ SHS exposure in Japan.MethodsThis is a repeated cross-sectional study of 41,833 infants born in 2001 and 32,120 infants born in 2010 in Japan from nationally representative surveys using questionnaires. The prevalence of infants’ SHS exposure was determined and related to household income and parental education level. The magnitudes of income and educational inequalities in infants’ SHS exposure were estimated in 2001 and 2010 using both absolute and relative inequality indices.ResultsThe prevalence of SHS exposure in infants declined from 2001 to 2010. The relative index of inequality increased from 0.85 (95% confidence interval [CI], 0.80 to 0.89) to 1.47 (95% CI, 1.37 to 1.56) based on income and from 1.22 (95% CI, 1.17 to 1.26) to 2.09 (95% CI, 2.00 to 2.17) based on education. In contrast, the slope index of inequality decreased from 30.9 (95% CI, 29.3 to 32.6) to 20.1 (95% CI, 18.7 to 21.5) based on income and from 44.6 (95% CI, 43.1 to 46.2) to 28.7 (95% CI, 27.3 to 30.0) based on education. Having only a father who smoked indoors was a major contributor to absolute income inequality in infants’ SHS exposure in 2010, which increased in importance from 45.1% in 2001 to 67.0% in 2010.ConclusionsThe socioeconomic inequalities in infants’ second hand smoke exposure increased in relative terms but decreased in absolute terms from 2001 to 2010. Further efforts are needed to encourage parents to quit smoking and protect infants from second hand smoke exposure, especially in low socioeconomic households that include non-smoking mothers. 相似文献
107.
Shigeki Kobayashi Takehisa Susa Hironori Ishiguchi Takeki Myoren Wakako Murakami Takayoshi Kato Masakazu Fukuda Akihiro Hino Takeshi Suetomi Makoto Ono Hitoshi Uchinoumi Hiroki Tateishi Mamoru Mochizuki Tetsuro Oda Shinichi Okuda Masahiro Doi Takeshi Yamamoto Masafumi Yano 《PloS one》2015,10(1)
Objectives
The purpose of this study was to investigate whether adding a low-dose β1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism.Background
The molecular mechanism underlying how the combination of low-dose β1-blocker and milrinone affects intracellular Ca2+ handling in heart failure remains unclear.Methods
We investigated the effect of milrinone plus landiolol on intracellular Ca2+ transient (CaT), cell shortening (CS), the frequency of diastolic Ca2+ sparks (CaSF), and sarcoplasmic reticulum Ca2+ concentration ({Ca2+}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB).Results
In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca2+}SR. Co-administration of β1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca2+}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes.Conclusion
A low-dose β1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca2+ leak. 相似文献108.
109.
Pyrrole derivatives as potent inhibitors of lymphocyte-specific kinase: Structure,synthesis, and SAR
Tetsuo Takayama Hiroki Umemiya Hideaki Amada Tetsuya Yabuuchi Fumiyasu Shiozawa Hironori Katakai Akiko Takaoka Akie Yamaguchi Mayumi Endo Masakazu Sato 《Bioorganic & medicinal chemistry letters》2010,20(1):108-111
We have described the synthesis, enzyme inhibitory activity, structure–activity relationships, and proposed binding mode of a novel series of pyrrole derivatives as lymphocyte-specific kinase (Lck) inhibitors. The most potent analogs exhibited good enzyme inhibitory activity (IC50s <10 nM) for Lck kinase inhibition. 相似文献
110.