1,082 research outputs found
Fear of Forgetting: How Societies Deal with Genocide
This thesis discusses how certain societies (Germany, Israel, and Argentina) that have been involved in two documented cases of genocide in the 20th Century -- one that was the source for and falls within the United Nations Treaty definition of genocide (the Holocaust), and one that does not (the Dirty War in Argentina) --have dealt with these events in their recent past. In dealing with these issues, the thesis employs the analysis of genocide developed by the Argentine scholar, Daniel Feierstein, who has proposed that all genocides progress through a series of steps that first create what he calls a negative otherness to the victims of the genocide, that then isolates and debilitates the victim group, and that ultimately leads, as a penultimate (not final) step, to the physical annihilation of the victims of the genocide. Feierstein\u27s most novel and provocative contribution to the study of genocide, however, is his concept that there is an additional and final step -- which he calls the threat of âsymbolic realizationâ -- that will actually take place in society after the killing or physical annihilation has been completed and the historical order of things has been restored. In Feiersteinâs view, the purpose of genocide is to use the technologies of power of the state against the victim group in order to permanently change social relations within the state by excluding and then annihilating the victims of the genocide. For this reason, Feierstein argues that, unless the post-genocide society continues to confront the causes and reality of the genocide as a present and ongoing political and social dynamic in the society, so that the memory and cultural and social presence of the victim group is preserved in an immediate way, the genocide will be realized on a symbolic level in the sense that the change of social relations that the perpetrators of the genocide intended will in fact occur. In the analysis that follows of the issues of assigning culpability, providing reparations, and constructing memorials in post-genocide societies, the thesis argues that, whether consciously articulated or not, what drives the bitter controversy and debates over these matters in post-genocide societies is an underlying fear on the part of victims and victim groups that the significance of what they have suffered and why they have suffered will be lost and forgotten (symbolically realized, in Feiersteinâs terminology) in the state\u27s efforts at reconciliation precisely through the process of assigning guilt, awarding reparations, and constructing memorials. Going a step beyond where Feierstein leaves off, the thesis suggests, however, that this sort of symbolic realization is, in fact, an inevitable and unavoidable consequence of the process of writing the history of the genocide (or any event) and the detachment, analysis, contextualization, reductiveness, and simplification that history requires
New treatments for breast cancer: Breakthroughs for patient care or just steps in the right direction?
Three areas of clinical research in breast cancer treatment led to news breaking presentations at the American Society of Clinical Oncology (ASCO) meeting, 1998, in Los Angeles. All three subjects represent important advances in cancer medicine. Prevention: Two related drugs, tamoxifen and raloxifene, were found in placebo controlled trials to significantly reduce the incidence of breast cancer for women at increased risk of developing the disease. Patterns of relapse showed that the reduced rate of breast cancer was exclusively observed for tumors expressing estrogen receptors, while the rate of tumors classified as estrogen-receptor negative was similar for the treatment and the control groups. This may indicate that the observed reduction in breast cancer incidence is due to a treatment effect on occult disease rather than its prevention. We certainly have no adequate information on mortality prevention. Adjuvant therapies: Taxol given every three weeks for four courses following an adjuvant treatment with four courses of doxorubicin and cyclophosphamide (AC) combination was found to be superior to not adding treatment after the four courses of AC in a trial involving 3170 patients. At 22 months of median follow-up, the quoted P-values were P = 0.0077 for disease-free survival and P = 0.039 for overall survival, but these did not cross the prospectively defined interim analysis boundaries for statistical significance at the 0.05 level. The difference was observed early during follow-up, and was exclusively seen in the 40% of patients who had ER-negative primaries and, therefore, did not receive tamoxifen following chemotherapy. One may thus argue that the early difference observed was primarily due to differences in the duration of the treatment regimens in the two groups and the early entry into the trial of patients with particularly aggressive neoplasia (e.g., ER-negative primaries) who would have benefited from a longer duration treatment. Treatment of advanced disease: The use of monoclonal antibodies to c-erb-B2 was found to induce responses in metastatic breast cancer. Patients with tumors expressing c-erb-B2 responded to weekly infusions of this biological agent. It was particularly impressive that the response rate for patients receiving infusion of the monoclonal antibodies together with the cytotoxics was superior to that with chemotherapy alone in a randomized trial. It is important to note that only patients with tumors overexpressing c-erbB-2 (the overall incidence is about 20%) were tested. It must still be demonstrated that the effect of these monoclonal antibodies is indeed confined to cells overexpressing c-erbB-2. Treatment related cardiac tox-icity remains a problem, and the effects of treatment in various subsets of patients need to be defined before starting investigations in the adjuvant setting, which is a clear further objective of this specific research. The significant findings from clinical research opened several new questions, which must be answered before allowing them to be employed in routine patient car
Q-TWiST analysis of lapatinib combined with capecitabine for the treatment of metastatic breast cancer
The addition of lapatinib (Tykerb/Tyverb) to capecitabine (Xeloda) delays disease progression more effectively than capecitabine monotherapy in women with previously treated HER2+ metastatic breast cancer (MBC). The quality-adjusted time without symptoms of disease or toxicity of treatment (Q-TWiST) method was used to compare treatments. The area under survival curves was partitioned into health states: toxicity (TOX), time without symptoms of disease progression or toxicity (TWiST), and relapse period until death or end of follow-up (REL). Average times spent in each state, weighted by utility, were derived and comparisons of Q-TWiST between groups performed with varying combinations of the utility weights. Utility weights of 0.5 for both TOX and REL, that is, counting 2 days of TOX or REL as 1 day of TWiST, resulted in a 7-week difference in quality-adjusted survival favouring combination therapy (P=0.0013). The Q-TWiST difference is clinically meaningful and was statistically significant across an entire matrix of possible utility weights. Results were robust in sensitivity analyses. An analysis with utilities based on EQ-5D scores was consistent with the above findings. Combination therapy of lapatinib with capecitabine resulted in greater quality-adjusted survival than capecitabine monotherapy in trastuzumab-refractory MBC patients
Expression-based clustering of CAZyme-encoding genes of Aspergillus niger
Background: The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains Delta xlnR, Delta araR, Delta amyR, Delta rhaR and Delta galX that were grown on their specific inducing compounds. Results: The cluster analysis of the expression data revealed several groups of co-regulated genes, which goes beyond the traditionally described co-regulated gene sets. Additional putative target genes of the selected regulators were identified, based on their expression profile. Notably, in several cases the expression profile puts questions on the function assignment of uncharacterized genes that was based on homology searches, highlighting the need for more extensive biochemical studies into the substrate specificity of enzymes encoded by these non-characterized genes. The data also revealed sets of genes that were upregulated in the regulatory mutants, suggesting interaction between the regulatory systems and a therefore even more complex overall regulatory network than has been reported so far. Conclusions: Expression profiling on a large number of substrates provides better insight in the complex regulatory systems that drive the conversion of plant biomass by fungi. In addition, the data provides additional evidence in favor of and against the similarity-based functions assigned to uncharacterized genes.Peer reviewe
Expression-based clustering of CAZyme-encoding genes of Aspergillus niger
Background: The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains Delta xlnR, Delta araR, Delta amyR, Delta rhaR and Delta galX that were grown on their specific inducing compounds. Results: The cluster analysis of the expression data revealed several groups of co-regulated genes, which goes beyond the traditionally described co-regulated gene sets. Additional putative target genes of the selected regulators were identified, based on their expression profile. Notably, in several cases the expression profile puts questions on the function assignment of uncharacterized genes that was based on homology searches, highlighting the need for more extensive biochemical studies into the substrate specificity of enzymes encoded by these non-characterized genes. The data also revealed sets of genes that were upregulated in the regulatory mutants, suggesting interaction between the regulatory systems and a therefore even more complex overall regulatory network than has been reported so far. Conclusions: Expression profiling on a large number of substrates provides better insight in the complex regulatory systems that drive the conversion of plant biomass by fungi. In addition, the data provides additional evidence in favor of and against the similarity-based functions assigned to uncharacterized genes.Peer reviewe
Subpopulation Treatment Effect Pattern Plot (STEPP) Methods with R and Stata
We introduce the stepp packages for R and Stata that implement the subpopulation treatment effect pattern plot (STEPP) method. STEPP is a nonparametric graphical tool aimed at examining possible heterogeneous treatment effects in subpopulations defined on a continuous covariate or composite score. More pecifically, STEPP considers overlapping subpopulations defined with respect to a continuous covariate (or risk index) and it estimates a treatment effect for each subpopulation. It also produces confidence regions and tests for treatment effect heterogeneity among the subpopulations. The original method has been extended in different directions such as different survival contexts, outcome types, or more efficient procedures for identifying the overlapping subpopulations. In this paper, we also introduce a novel method to determine the number of subjects within the subpopulations by minimizing the variability of the sizes of the subpopulations generated by a specific parameter combination. We illustrate the packages using both synthetic data and publicly available data sets. The most intensive computations in R are implemented in Fortran, while the Stata version exploits the powerful Mata language
Ki-67 Expression in Breast Cancer; Its Association with Grading Systems, Clinical Parameters and Other Prognostic Factors -- A Surrogate Marker?
BACKGROUND. The number of mitoses and, thus, the proliferative capacity of a tumor
is one of the most crucial variables for tumor grading. The Ki-67 nuclear antigen may
be considered as an alternative to mitotic counts in grading schemes and as a single
parameter that can be used in fine-needle aspirates and small biopsies.
METHODS. Immunohistochemistry using the anti-Ki-67 antibody MIB-1 was performed
on 434 breast carcinoma specimens from the International Breast Cancer
Study Group (formerly Ludwig) Trial V. Three groups based on Ki-67 percent were
used to replace the mitotic counts component in the Nottingham grade (NHG) to
produce the Nottingham/Ki-67 grade (NKG) and to assess Ki-67 as a single parameter.
RESULTS. In both the lymph node positive subgroup and the lymph node negative
subgroup, the NKG and Ki-67 group was correlated significantly with Bloomâ
Richardson grade (BRG), NHG, and Nottingham type. Tumor size in the lymph
node negative cohort and estrogen receptor status, progesterone receptor status,
and c-erbB-2 expression in the lymph node positive cohort also were correlated
significantly with NKG. Ki-67 percentage was correlated significantly with c-erbB-2
expression in the lymph node positive cohort only. NKG was similar to BRG and
NHG when it was evaluated for prognostic significance. Patients with higher
categoric Ki-67 percentages had worse overall and disease free survival in all
groups except for the untreated, lymph node negative group.
CONCLUSIONS. Ki-67 detection represents a valuable tool and is a good objective
substitute for mitotic counts when used in a grading system. When it is used alone,
Ki-67 detection provides valuable information, although it is necessary to combine
this with other parameters in the study of core biopsies and fine-needle aspirates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91948/1/2003 Cancer Ki-67 Expression in Breast Carcinoma.pd
The effect of endocrine responsiveness on high-risk breast cancer treated with dose-intensive chemotherapy: results of International Breast Cancer Study Group Trial 15-95 after prolonged follow-up
Background: The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established. Patients and methods: Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m2 plus cyclophosphamide 4 mg/m2 with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features. Results: At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58-1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03). Conclusions: After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encourage
The presence of trace components significantly broadens the molecular response of Aspergillus niger to guar gum
Guar gum consists mainly of galactomannan and constitutes the endosperm of guar seeds that acts as a reserve polysaccharide for germination. Due to its molecular structure and physical properties, this biopolymer has been considered as one of the most important and widely used gums in industry. However, for many of these applications this (hemi-) cellulosic structure needs to be modified or (partially) depolymerized in order to customize and improve its physicochemical properties. In this study, transcriptome, exoproteome and enzyme activity analyses were employed to decipher the complete enzymatic arsenal for guar gum depolymerization by Aspergillus niger. This multi-omic analysis revealed a set of 46 genes encoding carbohydrate-active enzymes (CAZymes) responding to the presence of guar gum, including CAZymes not only with preferred activity towards galactomannan, but also towards (arabino-) xylan, cellulose, starch and pectin, likely due to trace components in guar gum. This demonstrates that the purity of substrates has a strong effect on the resulting enzyme mixture produced by A. niger and probably by other fungi as well, which has significant implications for the commercial production of fungal enzyme cocktails.Peer reviewe
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