920 resultados para Leave alone
Resumo:
Purpose: Some phase II studies have suggested that the combination of interferons (IFNs) with dacarbazine (DTIC) in the treatment of malignant melanoma (MM) increases the antitumor activity of DTIC alone. In an attempt to confirm this hypothesis, a randomized study was performed with the further intent of observing whether low doses of recombinant interferon alfa-2a (rIFNα2a) could be as effective as intermediate doses. Patients and Methods: Two hundred sixty-six patients were randomized onto three different treatment arms: DTIC 800 mg/m 2 intravenously (IV) days 1 and 21; DTIC plus rIFNα2a 9 mIU intramuscularly (IM) daily; and DTIC plus rIFNα2a 3 mIU IM three times per week. Major prognostic factors were well balanced among the three arms. Chemotherapy was administered for a maximum of eight cycles. After 6 months of therapy, rIFNα2a was continued until disease progression at 3 mIU three times per week in responding patients who had received the combined treatment. Results: The percentage of objective responses did not differ among the three groups (20%, 28%, and 23%, respectively), although a significant prolongation of response duration was observed when rIFNα2a was added to DTIC (2.6 v 8.4 v 5.5 months, respectively). However, this improvement in response duration did not translate into an amelioration of overall survival. The addition of rIFNα2a led to the onset of flu-like syndrome, but in no case was it necessary to withdraw the treatment program and no toxic deaths or life-threatening toxicities were reported. Conclusion: In this study, rIFNα2a significantly prolonged response duration, whereas no effects on response rate and survival were observed; rIFNα2a 3 mIU appeared to be equally effective and better tolerated than 9 mIU.
Resumo:
During bone development and repair, angiogenesis, osteogenesis and bone remodelling are closely associated processes that share some common mediators. In the present study non-adherent human bone marrow mononuclear cells under the induction of sRANKL and M-CSF, differentiated into osteoclasts with TRAP positive staining, VNR expression, and Ca-P resorptive activity. The effects of various combinations of rhBMP-2 (0, 3, 30, 300 ng/ml) and rhVEGF (0, 25 ng/ml) on osteoclastogenesis potentials were examined in this experimental system. The percentages of TRAP-positive multiple nucleated cells represent osteoclast differentiation potential and the percentages of resorptive areas in the Ca-P coated plates resemble osteoclast resorption capability. The presence of rhBMP-2 at 30 and 300 ng/ml showed inhibitory effects on osteoclast differentiation and their resorptive capability in the human osteoclast culture system. rhVEGF (25 ng/ml) enhanced the resorptive function of osteoclast whenever it was used alone or combined with 3 ng/ml rhBMP-2. However, rhVEGF induced resorptive function was inhibited by 30 ng/ml and 300 ng/ml rhBMP-2 at a dose-dependent manner. Statistical analysis demonstrated that an interactive effect exists between rhBMP-2 and rhVEGF on human osteoclastogenesis. These findings suggested that an interactive regulation may exist between BMPs and VEGF signaling pathways during osteoclastogenesis, exact mechanisms are yet to be elucidated.
Resumo:
Purpose: Up to now, there have been no established predictive markers for response to epidermal growth factor receptor (EGFR/HER1/erbB1) inhibitors alone and in combination with chemotherapy in colorectal cancer. To identify markers that predict response to EGFR-based chemotherapy regimens, we analyzed the response of human colorectal cancer cell lines to the EGFR-tyrosine kinase inhibitor, gefitinib (Iressa, AstraZeneca, Wilmington, DE), as a single agent and in combination with oxaliplatin and 5-fluorouracil (5-FU). Experimental Design: Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and crystal violet cell viability assays and analyzed by ANOVA. Apoptosis was measured by flow cytometry, poly(ADP-ribose) polymerase, and caspase 3 cleavage. EGFR protein phosphorylation was detected by Western blotting. Results: Cell lines displaying high constitutive EGFR phosphorylation (a surrogate marker for EGFR activity) were more sensitive to gefitinib. Furthermore, in cell lines exhibiting low constitutive EGFR phosphorylation, an antagonistic interaction between gefitinib and oxaliplatin was observed, whereas in cell lines with high basal EGFR phosphorylation, the interaction was synergistic. In addition, oxaliplatin treatment increased EGFR phosphorylation in those cell lines in which oxaliplatin and gefitinib were synergistic but down-regulated EGFR phosphorylation in those lines in which oxaliplatin and gefitinib were antagonistic. In contrast to oxaliplatin, 5-FU treatment increased EGFR phosphorylation in all cell lines and this correlated with synergistic decreases in cell viability when 5-FU was combined with gefitinib. Conclusions: These results suggest that phospho-EGFR levels determine the sensitivity of colorectal cancer cells to gefitinib alone and that chemotherapy-mediated changes in phospho-EGFR levels determine the nature of interaction between gefitinib and chemotherapy.
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This paper responds to Wassell and LaVan’s paper on the transition from a preservice coteaching experience to independent teaching as a beginning inservice teacher. Wassell and LaVan describe coteaching as an alternative to traditional teaching. In our response, we argue that coteaching can also be applied alongside independent teaching in preservice courses, as opposed to an alternative to independent teaching, which has been shown to alleviate some of the transition issues described by Wassell and LaVan. We then present a critical discussion of different models and vocabularies of coteaching which apply in different sociocultural settings to expand the concept of coteaching. We attempt to extend Wassell and LaVan’s use of Guba and Lincoln’s (Fourth generation evaluation, 1989) authenticity criteria from the research methodology towards considering the criteria also as a framework for coteaching as practice for preservice and cooperating teachers. Finally, we reflect on the role of critical ethnography in Wassell and LaVan’s study in terms of the researchers’ intervention and whether improvements in the transition can be effectively introduced which do not require such intervention. We conclude our discussion with some suggestions to take forward this important work.
Resumo:
This paper uses a unique Portuguese dataset to examine the effect of access to unemployment benefits (UBs) and their maximum potential duration on escape rates from unemployment. In examining the time profile of transitions out of unemployment, the principal contributions of the paper are twofold. First, it provides a detailed state space of potential outcomes: open-ended employment, fixed-term contracts, part-time work, government-provided jobs, self employment, and labour force withdrawal. Second, it is able to exploit major exogenous discontinuities in the maximum duration of unemployment benefits to identify disincentive effects. While confirming strong disincentive effects, it is shown that use of an aggregate hazard function regression model compounds very different and even contradictory effects of the determinants of unemployment.
Resumo:
This ongoing prospective study examined characteristics of school neighborhood and neighborhood of residence as predictors of sick leave among school teachers. School neighborhood income data for 226 lower-level comprehensive schools in 10 towns in Finland were derived from Statistics Finland and were linked to register-based data on 3,063 teachers with no long-term sick leave at study entry. Outcome was medically certified (> 9 days) sick leave spells during a mean follow-up of 4.3 years from data collection in 2000-2001. A multilevel, cross-classified Poisson regression model, adjusted for age, type of teaching job, length and type of job contract, school size, baseline health status, and income level of the teacher's residential area, showed a rate ratio of 1.30 (95% confidence interval: 1.03, 1.63) for sick leave among female teachers working in schools located in low-income neighborhoods compared with those working in high-income neighborhoods. A low income level of the teacher's residential area was also independently associated with sick leave among female teachers (rate ratio = 1.50, 95% confidence interval: 1.18, 1.91). Exposure to both low-income school neighborhoods and low-income residential neighborhoods was associated with the greatest risk of sick leave (rate ratio = 1.71, 95% confidence interval: 1.27, 2.30). This study indicates that working and living in a socioeconomically disadvantaged neighborhood is associated with increased risk of sick leave among female teachers.
Resumo:
The use of barcode technology to capture data on pharmacists' clinical interventions is described.