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991.
J Liu WM Flanagan JA Drazba ML Estes GH Barnett T Haqqi S Kondo BP Barna 《Canadian Metallurgical Quarterly》1997,159(2):812-819
IL-4 is a pleiotrophic cytokine that has been shown to affect cells of the central nervous system. We have demonstrated that IL-4 inhibits DNA synthesis and proliferation in human astroglia expressing IL-4 receptors. In this study, we sought to identify mechanisms that could account for the antimitogenic effects of IL-4. Epidermal growth factor (EGF)-stimulated human astroglia were arrested in G1 phase by IL-4, even though IL-4 stimulated levels of the G1 cyclins, D1 and E. Histone H1 kinase activity of cdk2 immunoprecipitates, however, was sharply reduced by IL-4; impairment of kinase activity was also evident in cyclin E immunoprecipitates, which contained evidence of hypophosphorylated (inactive) cdk2 product. Reduced cyclin E-associated cdk2 activity was not due to impaired cyclin-dependent kinase-activating kinase (CAK) activity, which was unaffected by IL-4. Inactive cyclin E/cdk2 complexes from IL-4 + EGF-treated cells contained, however, strikingly elevated p27Kip1 cdk inhibitor. Elevated p27 was also detectable in whole cell lysates after 24 and 48 h of IL-4 treatment; by 72 h, p27 was no longer elevated. Pretreatment with antisense but not mismatch p27 oligonucleotides attenuated the inhibitory effects of IL-4 on DNA synthesis and histone kinase activity of cyclin E/cdk2 complexes. Antisense p27 also abrogated IL-4-mediated elevation of p27 in whole cell lysates and cyclin E/cdk2 complexes. These findings demonstrate that IL-4 regulates the cell cycle machinery of astroglial cells via a p27Kip1 braking mechanism. 相似文献
992.
993.
GH Bopp 《Canadian Metallurgical Quarterly》1976,15(4):161-163
The applicability of the image converter in kidneys stone operations, and particularly in coral calculus operations, is discussed. A comparison is made with other X-ray methods and the advantages of an extended area of use of the image converter is presented. 相似文献
994.
Nutrient Cycling in Agroecosystems - 相似文献
995.
EJ de Geus GH Willemsen CH Klaver LJ van Doornen 《Canadian Metallurgical Quarterly》1995,41(3):205-227
The present study describes a device (AMD43) for ambulatory measurement of respiration rate and respiratory sinus arrhythmia from the combined electrocardiogram (ECG) and thoracic impedance signals. Respiratory time intervals derived from this ambulatory device closely corresponds to those derived from simultaneous recordings with a 'classical' laboratory set-up. Good cross-instrument comparison was also found for respiratory sinus arrhythmia parameters derived with both the peak-to-trough and spectral analyses methods. It is discussed how simultaneous measurement of respiration rate, respiratory sinus arrhythmia may be used to assess cardiac vagal tone in real-life situations. 相似文献
996.
997.
MA Mittleman M Maclure JB Sherwood RP Mulry GH Tofler SC Jacobs R Friedman H Benson JE Muller 《Canadian Metallurgical Quarterly》1995,92(7):1720-1725
PURPOSE: We performed this study to identify prognostic factors in a subgroup of patients with carcinoma of unknown primary site treated with cisplatin combination chemotherapy. PATIENTS AND METHODS: Seventy-nine patients with poorly differentiated adenocarcinoma or undifferentiated carcinoma of unknown primary site were treated on two consecutive phase II chemotherapy protocols. The first protocol consisted of treatment with 3-week courses of cisplatin, etoposide, and bleomycin (BEP). In the second protocol, cisplatin was administered weekly combined with oral administration of etoposide (DDP/VP). To identify prognostic factors, univariate and multivariate analyses were conducted. RESULTS: In the univariate analysis, performance status, histology, liver or bone metastases, and serum levels of alkaline phosphatase and AST were significant variables to predict survival. In the multivariate analysis, performance status and alkaline phosphatase were the most important prognostic factors. CONCLUSION: Good-prognosis patients had a performance score of 0 (World Health Organization [WHO]) and an alkaline phosphatase serum level less than 1.25 times the upper limit of normal (N). These patients had a median survival duration greater than 4 years. Intermediate-prognosis patients were characterized by either a WHO performance status < or = 1 or an alkaline phosphatase level > or = 1.25 N. These patients had a median survival duration of 10 months and a 4-year survival rate of only 15%. The poor-prognosis group had both a WHO performance status > or = 1 and an alkaline phosphatase level > or = 1.25 N. These patients had a median survival duration of only 4 months and none survived beyond 14 months. Treatment strategies for these three groups are discussed. It is suggested that this prognostic model be validated in other patients series. 相似文献
998.
999.
Adrenal medulla and carotid body of cats are studied with acrylic aldehyde-dichromate and glutaraldehyde-dichromate methods for catecholamines. The frequency of dark vesicles and the mean diameter of the cores obtained by these specific methods are compared with those found by the standard glutaraldehyde-osmium method in normal and reserpine-treated animals. In the samples of normal organs fixed with aldehyde-dichromate methods, the number of dark-cored vesicles is significantly higher than in the controls. On the contrary, in the adrenal gland of reserpine-treated specimens the specific methods demonstrate reductions in the frequency of dark vesicles that can be semiquantitatively compared with the known diminution in the content of catecholamines produced by the drug. In the carotid body it was not found a so strict relation, nevertheless the specific methods give a consistently lower frequency of dark vesicles in reserpine-treated than in control animals. It is suggested that the discrepancy between standard and specific methods in the carotid body is due to substances existent in the dark cores contrasted by the former procedure but not by the latter. The constancy of the mean diameter of the cores even in glands that have lost 93% of their granules confirms the suggestion of an all-or-nothing exocytotic mechanism of discharge of the secretory vesicles. The inverse relation shown between the frequency of dark and clear vesicles indicates that membranes emerge in the cytoplasm after exocytosis as clear vesicles. 相似文献
1000.
GH Sharwood-Smith 《Canadian Metallurgical Quarterly》1976,31(4):508-510
Doses of four commercial formulations and one experimental formulation of Bacillus thuringiensis Berliner were mixed with the diet used to rear colonies of the Indian meal moth Plodia interpunctella (Hübner). Indian meal moth eggs were introduced to the treated diet, and the resultant adult emergence was tabulated. The experimental formulations ranked as follows in efficacy in controlling the Indian meal moth: Dipel (50% lethal concentration [LC50], 25 mg/kg) greater than Bactospeine WP (LC50, 100 mg/kg) greater than Thuricide (LC50, 150 mg/kg) greater than IMC 90007 (LC30, 180 mg/kg) greater than Bactospeine Flowable (LC50, 440 mg/kg). 相似文献