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71.
Noritsugu Yabe Kouji Komiya Tetsuya Takezono Hisao Matsui 《In vitro cellular & developmental biology. Animal》1993,29(10):795-806
Summary Lysozyme at 1 to 100μg/ml of exposure levels augmented or inhibited proliferative response of human peripheral blood lymphocytes stimulated with
interleukin-2 (IL-2). This contradictory effect of lysozyme depended on IL-2 concentration, activating state of lymphocytes,
addition time of lysozyme, and serum existence. Lymphocytes increased their IL-2-mediated proliferating ability in response
to lysozyme when stimulated with less than suboptimal concentration of IL-2. Lymphocyte activation with anti-CD3 antibody
changed the augmented proliferative response into the inhibited response by lysozyme addition whereas elimination of MHC class
II molecule-expressing cells augmented the response. Addition of lysozyme within 1 h after IL-2 exposure was most effective
in promoting the proliferation whereas additions after 16 to 24 h were ineffective or inhibitory. Addition after longer than
24 h inversely restored the proliferative response. Serum seemed to retard lysozyme action because either sequential serum
addition 1 h after exposure of IL-2 and lysozyme to cells or exposure of IL-2 and serum after pretreatment of cells with lysozyme
changed the proliferative responsiveness from inhibition into augmentation. Thus lysozyme may regulate lymphocyte proliferation
responding to a magnitude of antigenic stimuli and to the progression of cellular events that periodically occur. 相似文献
72.
Tetsuya Kimura Taku Hamada Linda Massako Ueno Toshio Moritani 《Journal of electromyography and kinesiology》2003,13(5):433-440
The present study examined, whether or not mechanomyogram (MMG) amplitude and frequency component could reflect the contractile properties of the triceps surae muscles, composed of relatively slow soleus (SOL) and fast medial gastrocnemius (MG), during experimentally induced hypothermia condition. In eight male subjects, lying in prone position, supramaximal single twitch and repetitive electrical stimulations at 10 Hz were applied at the intramuscular temperatures of control (34 degrees C), 15, 20, and 25 degrees C, respectively. The hypothermia induced substantial reduction in muscle contractile properties, e.g. prolonged twitch contraction and half relaxation times, resulted in a highly significant reduction in the fluctuation of force signal during the repetitive stimulations. These changes were almost mirrored by the similar and significant reductions in the MMG amplitude in both SOL and MG. Power spectrum analysis revealed that peak frequency components of MMG and fluctuation of force were almost matched with the applied stimulation frequencies, independent of the temperature condition. These results strongly suggest that MMG analysis could be employed to study muscle contractile properties varying across different physiological conditions. 相似文献
73.
Tetsuya Tanigawa Yasuo Mizo-oku Kouichi Moriguchi Takashi Suzuki Takahiko Osumi Masaaki Odomi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,683(2):135
A simple and rapid quantitative method for 13C-labelled urea ([13C]urea) in human serum was developed by using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS). This method is used to establish and normalize the [13C]urea breath test, which is considered as an effective diagnostic method for Helicobacter pylori infection. HPLC-APCI-MS, involving a simple pretreatment process such as diluting serum with water, was shown to be able to discriminate the extrinsic [13C]urea from intrinsic urea present at high concentration in serum. In addition, a 13C nuclear magnetic resonance spectroscopic quantitative method for [13C]urea in human urine is also described. The precision and accuracy of measured concentrations in these two methods were found to be within the acceptable limit. An application of these methods to investigate the pharmacokinetic profile of orally administered [13C]urea in human serum and urine is also presented. 相似文献
74.
Yuji Moriwaki Tetsuya Yamamoto Kei Yamaguchi Sumio Takahashi Kazuya Higashino 《Histochemistry and cell biology》1996,105(1):71-79
Tissues from male Wistar rats, fixed with 4% paraformaldehyde and embedded in paraffin, were studied with immunoperoxidase techniques using polyclonal antibodies raised against aldehyde oxidase or xanthine oxidase purified from rat liver. Immunohistochemical studies demonstrated that aldehyde oxidase-bearing cells were strongly stained in renal tubules, esophageal, gastric, intestinal and bronchial epithelium as well as liver cytoplasm. Weak but positive immunoreactivity was observed on the pulmonary alveolar epithelial cells, gastric glands and intestinal goblet cells. In contrast, it was demonstrated that cells with xanthine oxidase were strongly stained in renal tubules, esophageal, gastric, and small and large intestinal and bronchial epithelia etc. Positive immunostaining was also found in adrenal gland, skeletal muscle, spleen and cerebral hippocampus. Immunoreactivity againt aldehyde oxidase was not found in adrenal gland, spleen, mesentery or aorta, while immunoreactivity against xanthine oxidase was not found in mesentery or aorta. Although the significance of this ubiquitous and similar localization of aldehyde and xanthine oxidase seems unclear at present, these results may provide a clue as to the full understanding of the pathophysiological role of these oxidases in tissues. 相似文献
75.
76.
Chloroplast division in Nannochloris bacillaris Naumann (Chlorophyta) was examined by electron microscopy after preparation of samples by freeze-substitution. A pair of belts appeared on the surface of the outer and inner envelope membranes at the middle of the chloroplast. These belts seemed to be constructed of thin fibrils that run parallel to the longitudinal direction of the belts. The outer fibrillar belt increased in width as the constriction of the chloroplast advanced. It appears that the fibrillar belt is the division apparatus of the chloroplast. It encircles the chloroplast and finally divides the chloroplast in two as the diameter of the belt decreases. 相似文献
77.
Ken Lee Akihiro Ito †Kunio Koshimura †Tetsuya Ohue †Yasutaka Takagi †Soichi Miwa 《Journal of neurochemistry》1995,64(2):874-882
Abstract: Hypoxia is known to disturb neuronal signal transmission at the synapse. Presynaptically, hypoxia is reported to suppress the release of neurotransmitters, but its postsynaptic effects, especially on the function of neurotransmitter receptors, have not yet been elucidated. To clarify the postsynaptic effects, we used cultured bovine adrenal chromaffin cells as a model of postsynaptic neurons and examined specific binding of l -[3 H]nicotine (an agonist for nicotinic acetylcholine receptors: nAChRs) and 22 Na+ flux under control and hypoxic conditions. Experiments were performed in media preequilibrated with a gas mixture of either 21% O2 /79% N2 (control) or 100% N2 (hypoxia). Scatchard analysis of the specific binding to the cells revealed that the KD under hypoxic conditions was twice as large as that under control conditions, whereas the B max was unchanged. When the specific [3 H]nicotine binding was kinetically analyzed, the association constant ( k 1 ) but not the dissociation constant ( k −1 ) was decreased to 40% of the control value by hypoxia. When the binding assay was performed using the membrane fraction, these changes were not observed. Nicotine-evoked 22 Na+ flux into the cells was suppressed by hypoxia. In contrast, specific [3 H]quinuclidinyl benzilate binding to the intact cells was unaffected by hypoxia. These results demonstrate that hypoxia specifically suppresses the function of nAChRs (and hence, neuronal signal transmission through nAChRs), primarily by acting intracellularly. 相似文献
78.
79.
Marcus J. Swann David Bloor Tetsuya Haruyama Masuo Aizawa 《Biosensors & bioelectronics》1997,12(12):13
A fructose dehydrogenase (FDH) modified electrode is produced by the electroadsorption of a layer of FDH on a platinum electrode followed by the electropolymerization of a polypyrrole (PPy) film around and over the enzyme. This immobilizes and stabilizes the enzyme as well as providing an electron transfer pathway to the electrode. The amperometric response to fructose and the enzymatic activity are measured as a function of PPy film thickness. The electrode is shown to have a maximum response at a PPy thickness of approximately the thickness of the enzyme layer. A measure of the electrode efficiency is also obtained, this is the amperometric response to fructose as a percentage of that expected on the basis of the enzyme activity. The functioning of the electrode is also dependent on the counter-ion used for PPy polymerization. This is shown to be mainly related to the nucleation and growth of the PPy film in the interfacial region. 相似文献
80.
Q. Wang C.K. Noguchi M. Kuninobu Y. Hara K. Kakimoto H.I. Ogawa Y. Kato 《Biotechnology Techniques》1997,11(2):105-108
Continuous anaerobic digestion of waste activated sludge pretreated at low temperatures below 100°C increased methane generation by 30%. pH values of the digestion mixture increased, approximately from 0.3 to 0.55 by pretreatment, although its volatile fatty acids concentration was greater than the control. An abrupt increase in propionate : acetate ratio in digestion stage (e.g. from less than 1:1 to over 3.5 :1), provided a reliable indicator for impending failure.This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献