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41.
42.
T. Yoshimaru Y. Suzuki T. Matsui† K. Yamashita† T. Ochiai‡ M. Yamaki† K. Shimizu 《Clinical and experimental allergy》2002,32(4):612-618
BACKGROUND: Previous studies have shown that rat peritoneal mast cells and mast cell model rat basophilic leukaemia (RBL-2H3) cells generate intracellular reactive oxygen species (ROS) in response to antigen challenge. However, the physiological significance of the burst of ROS is poorly understood. OBJECTIVE: The present study was undertaken to investigate the role of superoxide anion in mediator release in rat and human cell systems. METHODS: RBL-2H3 cells were directly stimulated with anti-rat FcepsilonRI alpha-subunit monoclonal antibody (mAb). For the analysis of human cell system, leucocytes were isolated by dextran sedimentation from healthy volunteers or from patients, and challenged either with anti-human FcepsilonRI mAb or with the relevant antigens. Superoxide generation was determined by chemiluminescence-based methods. The releases of histamine and leukotrienes (LT)s were determined by enzyme-linked immunosorben assay (ELISA). RESULTS: Cross-linking of FcepsilonRI on RBL-2H3 cells or on human leucocytes from healthy donors by the anti-FcepsilonRI mAb resulted in a rapid generation of superoxide anion, as determined by chemiluminescence using superoxide-specific probes. Similarly, leucocytes from patients generated superoxide anion in response to the challenge with the relevant allergen but not with the irrelevant allergen. Furthermore, diphenyleneiodonium (DPI), a well-known inhibitor of flavoenzymes suppressed the superoxide generation and the release of histamine and LTC4 induced by the anti-FcepsilonRI mAb or by allergen in parallel. CONCLUSION: These results indicate that both RBL-2H3 cells and human basophils generate superoxide anion upon FcepsilonRI cross-linking either by antibody or by allergen challenge and that blockade of the generation prevents the release of allergic mediators. The findings strongly support the role of superoxide generation in the activation of mast cells and basophils under both physiological and pathological conditions. The findings suggest that drugs regulating the superoxide generation have potential therapeutic use for allergic disorders. 相似文献
43.
The effects of chronic dietary protein restriction on ischemic renal failure were evaluated in rats subjected to 90 min of bilateral renal clamping. The rats were kept on either 20% casein (regular) diet or casein-free (protein-free) diet 10 days before and 21 days after renal injury. Rats on regular protein diet showed higher levels of BUN and serum creatinine and had a lower inulin clearance (microliter/min/100 g BW) than animals on protein-free diet (289 +/- 34 vs 582 +/- 103, p less than 0.05) 2 days after ischemia. However, the inulin clearance measured 21 days following ischemia was significantly higher in rats on regular diet (1468 +/- 181) than those maintained on protein-free diet after ischemia (560 +/- 167). When unilateral 90 min ischemia was performed in rats on regular diet, the postischemic kidneys showed an incomplete recovery of the inulin clearance (226 +/- 35) compared to the contralateral kidney (900 +/- 116), 21 days after ischemia; whereas in rats on a protein-free diet the inulin clearance averaged 106 +/- 17 in the postischemic kidney and 345 +/- 41 in the right kidney. When left renal ischemia and contralateral nephrectomy were performed, the inulin clearance was 1149 +/- 74 in rats on regular diet and 534 +/- 60 in rats on protein-free diet, 21 days following renal insult. These results suggest that protein restriction can play a protective role against renal ischemia in an initial phase, but it limits the late recovery from ischemia. The presence of a normal contralateral kidney inhibits the functional recovery of the postischemic kidney and a contralateral nephrectomy produces a compensatory functional hypertrophy of the postischemic kidney, even in rats on a protein-free diet. 相似文献
44.
Two variant cells lines resistant to the nitrosourea derivative ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride), namely C6/ACNU and 9L/ACNU, were selected in vivo from rat brain tumors. Stable resistance to ACNU proved to be a characteristic of these cell lines, whether they were grown in vivo or in vitro. These cell lines exhibited a different pattern of cross-resistance to a wide range of chemotherapeutic agents with dissimilar chemical structures and mechanisms of action as compared with that of other ACNU-resistant cell lines established in vitro. Distinct cross-resistance was observed in both the C6/ACNU and 9L/ACNU cell lines to chloroethyl-nitrosoureas such as BCNU (carmustine), CCNU (lomustine), and methyl CCNU and, additionally, to vincristine, vinblastine, Adriamycin (doxorubicin), and arabinosylcytosine, but not to bleomycin, methotrexate, cis-platinum, and 5-fluorouracil. This might point to a multifactorial mechanism of drug resistance in ACNU-resistant cell lines derived from rat C6 and 9L brain tumor cells. 相似文献
45.
T Shimizu D K Dudley P Borodchack J Belcher S L Perkins W Gibb 《Gynecologic and obstetric investigation》1992,34(3):142-145
Fibronectin production from amnion and placental tissues was evaluated in pregnant woman smokers and nonsmokers in order to examine if there were alterations of fibronectin metabolism in intrauterine tissues. In both amnion and placental tissues, cycloheximide inhibited the fibronectin output indicating that it was being synthesized. Mean fibronectin output by amnion in pregnant woman smokers was significantly lower than that in pregnant woman nonsmokers. In contrast, in the placenta from pregnant woman smokers, the output was significantly higher than that in pregnant woman nonsmokers. The present observations indicate that smoking alters an important biochemical constituent in amnion and placenta, possible leading to some complications. 相似文献
46.
K Nakajima J Taki H Bunko M Taniguchi N Shuke I Kuji K Hisada M Shimizu 《Kaku igaku. The Japanese journal of nuclear medicine》1992,29(4):485-493
99mTc teboroxime is a new myocardial imaging agent that has characteristics of high accumulation in the heart and rapid clearance. We performed tomographic teboroxime study and compared the findings with that of 201Tl. Myocardial teboroxime clearance was calculated by dynamic single photon emission computed tomography (SPECT) using continuous repetitive rotation acquisition method. Teboroxime SPECT image was reconstructed by the three-minute data started from 4 minutes after injection. In 45 myocardial regions (15 patients), complete agreement between 201Tl and 99mTc teboroxime was obtained in 33 regions (73%), when the findings were classified as normal, ischemia and infarction. Significant delay in clearance was seen in the region of coronary stenosis (greater than or equal to 75%) compared with that in the control region (p = 0.0087 at rest, and p = 0.0385 at peak exercise by paired T test). Septum-to-lateral ratios of the clearance and myocardial initial count showed positive correlation (r = 0.743). Further clinical application of this radiopharmaceutical is expected as a new myocardial imaging agent. 相似文献
47.
48.
T Nakanishi A Shimizu 《Rinsho byori. The Japanese journal of clinical pathology》1992,40(11):1161-1167
We reevaluated the optimum conditions for analysis of 13 urinary organic acids using solvent extraction and GC/MS by the stable isotope dilution technique. The acids analyzed were uracil, and lactic, oxalic, 3-hydroxybutyric, succinic, fumaric, glutaric, adipic, pyroglutamic, 2-ketoglutaric, orotic, sebacic, and citric acids. Analytical recovery and accuracy for 13 organic acids ranged from 90 to 107% and from 1.6 to 13.7%, respectively. The optimal pH for most organic acids was 1-2, while that for oxalic and citric acids was 0.25, and that for 2-ketoglutaric and orotic acids was 0.5. The presence of urinary albumin decreased the extraction rates of organic acids, especially of orotic and citric acids; in slight albuminuria (0.5 g/l) the extraction recovery (the extraction rate with albumin/that without albumin) of orotic and citric acid was 38% and 67%, respectively, and in more marked albuminuria (5 g/l), 6% and 26%. Membrane pretreatment with Centricon-3 improved these extraction rates under the condition of albuminuria. Dehydration with the desiccant agent decreased urinary acid extraction rates, especially of uracil and orotic and citric acids. The extraction rates of these three organic acids was decreased in albuminuria and by the desiccant agent. Accurate quantitative analysis of urinary organic acids by the stable isotope dilution technique is necessary for routine examination conducted in clinical laboratories. 相似文献
49.
Analogues of erythrocyte protein 4.1, spectrin and ankyrin were examined in the thyroid gland of pig and rat by immunohistochemical techniques. Analysis with immunofluorescence microscopy revealed that the peripheral cytoplasm and apical-lateral plasma membrane of follicle epithelial cells of thyroid glands were stained with antibodies against erythrocyte protein 4.1, spectrin, or ankyrin. The results indicate that membrane skeletal protein lattice might exist in thyroid follicle epithelial cells. 相似文献
50.
H Katoh K Manabe A Shimizu K Shima H Chigasaki K Tsuchiya 《No shinkei geka. Neurological surgery》1992,20(10):1119-1123
A case of traumatic spinal subarachnoid hematoma causing compression of the cauda equina is reported here. The patient, a 76 year-old woman, who had fallen down by accident 1 month before, was admitted to our hospital presenting lumbar pain radiating into her right thigh, monoplegia of the right leg and urinary incontinence. Myelography and metrizamide CT demonstrated a filling defect mimicking intradural extramedullary tumor at the level of L1 and L2. Magnetic resonance imagings (MRI) revealed a subacute or chronic hematoma compressing the conus medullaris and the cauda equina. Operation was performed and an old hematoma, which occupied most of the spinal subarachnoid space and compressed the conus and cauda equina from right to left, was removed. No definite bleeding point was detected and no traumatic change was seen on the cord. Neither tumor nor abnormal vessel was detected. After surgery, the symptoms improved partially. On a review of the literature, we found only 4 cases of traumatic spinal subarachnoid hematoma, all of which occupied the cervical or thoracic portion of the spine. Our case is the first report, except for the cases following lumbar spinal tap, of traumatic spinal subarachnoid hematoma causing compression of the cauda equina. Though usually blood in CSF diffuses immediately, a clot may be formed when a large amount of bleeding obstructs the spinal canal. In our case, furthermore, deformity and narrowing of the spinal canal had preceded for many years, following lumbar vertebral compressed fracture related with osteoporosis. This might have promoted the process of canal obstruction and clot formation.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献