403 research outputs found
The availability of local aerial photography in southern California
Some of the major photography and photogrammetric suppliers and users located in Southern California are listed. Recent trends in aerial photographic coverage of the Los Angeles basin area are also noted, as well as the uses of that imagery
Aluminum Tolerance QTL in Diploid Alfalfa
Aluminum (Al) toxicity associated with acid soils greatly inhibits alfalfa (Medicago sativa L.) productivity throughout much of the world’s major grassland areas. In this paper, we report the identification of quantitative trait loci (QTL) controlling aluminum tolerance in diploid alfalfa (Medicago sativa L). An in vitro callus growth bioassay was used to select aluminum tolerant and aluminum sensitive parents, and to screen an F2 population for aluminum tolerance. Fifty-eight cDNA probes were mapped to nine linkage groups, and the F2 genotypic classes were contrasted with means from the callus growth bioassay using ANOVA. We also used Mapmaker-QTL to identify markers associated with aluminum tolerance. Four markers, UGAc044, UGAc053, UGAc141, and UGAc782, were found to be associated with aluminum tolerance. UGAc044 had the greatest effect, accounting for 15% (LOD 2.3) of the variation in aluminum tolerance
Synergistic drug combinations from electronic health records and gene expression.
ObjectiveUsing electronic health records (EHRs) and biomolecular data, we sought to discover drug pairs with synergistic repurposing potential. EHRs provide real-world treatment and outcome patterns, while complementary biomolecular data, including disease-specific gene expression and drug-protein interactions, provide mechanistic understanding.MethodWe applied Group Lasso INTERaction NETwork (glinternet), an overlap group lasso penalty on a logistic regression model, with pairwise interactions to identify variables and interacting drug pairs associated with reduced 5-year mortality using EHRs of 9945 breast cancer patients. We identified differentially expressed genes from 14 case-control human breast cancer gene expression datasets and integrated them with drug-protein networks. Drugs in the network were scored according to their association with breast cancer individually or in pairs. Lastly, we determined whether synergistic drug pairs found in the EHRs were enriched among synergistic drug pairs from gene-expression data using a method similar to gene set enrichment analysis.ResultsFrom EHRs, we discovered 3 drug-class pairs associated with lower mortality: anti-inflammatories and hormone antagonists, anti-inflammatories and lipid modifiers, and lipid modifiers and obstructive airway drugs. The first 2 pairs were also enriched among pairs discovered using gene expression data and are supported by molecular interactions in drug-protein networks and preclinical and epidemiologic evidence.ConclusionsThis is a proof-of-concept study demonstrating that a combination of complementary data sources, such as EHRs and gene expression, can corroborate discoveries and provide mechanistic insight into drug synergism for repurposing
Altered Expression of Telomere-Associated Genes in Leukocytes among BRCA1 and BRCA2 Carriers
Telomere dysfunction resulting from telomere shortening and deregulation of shelterin components has been linked to the pathogenesis of age-related disorders, including cancer. Recent evidence suggests that BRCA1/2 (BRCA1 and BRCA2) tumor suppressor gene products play an important role in telomere maintenance. Although telomere shortening has been reported in BRCA1/2 carriers, the direct effects of BRCA1/2 haploinsufficiency on telomere maintenance and predisposition to cancer development are not completely understood. In this study, we assessed the telomere-associated and telomere-proximal gene expression profiles in peripheral blood leukocytes from patients with a BRCA1 or BRCA2 mutation, compared to samples from sporadic and familial breast cancer individuals. We found that 25 genes, including TINF2 gene (a negative regulator of telomere length), were significantly differentially expressed in BRCA1 carriers. Leukocyte telomere length analysis revealed that BRCA1/2 carriers had relatively shorter telomeres than healthy controls. Further, affected BRCA1/2 carriers were well differentiated from unaffected BRCA1/2 carriers by the expression of telomere-proximal genes. Our results link BRCA1/2 haploinsufficiency to changes in telomere length, telomere-associated as well as telomere-proximal gene expression. Thus, this work supports the effect of BRCA1/2 haploinsufficiency in the biology underlying telomere dysfunction in cancer development. Future studies evaluating these findings will require a large study population
Avoidant Coping and Self-efficacy Mediate Relationships between Perceived Social Constraints and Symptoms among Long-term Breast Cancer Survivors
Objective
Many breast cancer survivors feel constrained in discussing their cancer experience with others. Limited evidence suggests that social constraints (e.g., avoidance and criticism) from loved ones may negatively impact breast cancer survivors' global health, but research has yet to examine relationships between social constraints and common physical symptoms. Informed by social cognitive processing theory, this study examined whether perceived social constraints from partners and healthcare providers (HCPs) were associated with fatigue, sleep disturbance, and attentional functioning among long-term breast cancer survivors (N = 1052). In addition, avoidant coping and self-efficacy for symptom management were examined as potential mediators of these relationships.
Methods
Long-term breast cancer survivors (mean years since diagnosis = 6) completed questionnaires assessing social constraints from partners and HCPs, avoidant coping, self-efficacy for symptom management, and symptoms (i.e., fatigue, sleep disturbance, and attentional functioning). Structural equation modeling was used to evaluate the hypothesized relationships among variables in two models: one focused on social constraints from partners and one focused on social constraints from HCPs.
Results
Both models demonstrated good fit. Consistent with theory and prior research, greater social constraints from both partners and HCPs were associated with greater symptom burden (i.e., greater fatigue and sleep disturbance, poorer attentional functioning). In addition, all relationships were mediated by avoidant coping and self-efficacy for symptom management.
Conclusions
Findings are consistent with social cognitive processing theory and suggest that symptom management interventions may be enhanced by addressing the impact of social constraints from survivors' partners and HCPs on their coping and self-efficacy
Impact of Genetic Ancestry on Outcomes in ECOG-ACRIN-E5103
Purpose:
Racial disparity in breast cancer outcomes exists between African American and Caucasian women in the United States. We have evaluated the impact of genetically determined ancestry on disparity in efficacy and therapy-induced toxicity for breast cancer patients in the context of a randomized, phase III adjuvant trial.
Patients and Methods:
This study compared outcomes between 386 patients of African ancestry (AA) and 2473 patients of European ancestry (EA) in a randomized, phase III breast cancer trial; ECOG-ACRIN-E5103. The primary efficacy endpoint, invasive disease free survival (DFS) and clinically significant toxicities were compared including: anthracycline-induced congestive heart failure (CHF), taxane-induced peripheral neuropathy (TIPN), and bevacizumab-induced hypertension.
Results:
Overall, AAs had significantly inferior DFS (p=0.002; HR=1.5) compared with EAs. This was significant in the estrogen receptor-positive subgroup (p=0.03); with a similar, non-significant trend for those who had triple negative breast cancer (TNBC; p=0.12). AAs also had significantly more grade 3-4 TIPN (OR=2.9; p=2.4 ×10-11) and grade 3-4 bevacizumab-induced hypertension (OR=1.6; p=0.02), with a trend for more CHF (OR=1.8; p=0.08). AAs had significantly more dose reductions for paclitaxel (p=6.6 ×10-6). In AAs, dose reductions in paclitaxel had a significant negative impact on DFS (p=0.03); whereas in EAs, dose reductions did not impact outcome (p=0.35).
Conclusion:
AAs had inferior DFS with more clinically important toxicities in ECOG-ACRIN-E5103. The altered risk to benefit ratio for adjuvant breast cancer chemotherapy should lead to additional research with the focus centered on the impact of genetic ancestry on both efficacy and toxicity. Strategies to minimize dose reductions for paclitaxel, especially due to TIPN, are warranted for this population
Charcot-Marie-Tooth gene, SBF2, associated with taxaneinduced peripheral neuropathy in African Americans
PURPOSE:
Taxane-induced peripheral neuropathy (TIPN) is one of the most important survivorship issues for cancer patients. African Americans (AA) have previously been shown to have an increased risk for this toxicity. Germline predictive biomarkers were evaluated to help identify a priori which patients might be at extraordinarily high risk for this toxicity.
EXPERIMENTAL DESIGN:
Whole exome sequencing was performed using germline DNA from 213 AA patients who received a standard dose and schedule of paclitaxel in the adjuvant, randomized phase III breast cancer trial, E5103. Cases were defined as those with either grade 3-4 (n=64) or grade 2-4 (n=151) TIPN and were compared to controls (n=62) that were not reported to have experienced TIPN. We retained for analysis rare variants with a minor allele frequency <3% and which were predicted to be deleterious by protein prediction programs. A gene-based, case-control analysis using SKAT was performed to identify genes that harbored an imbalance of deleterious variants associated with increased risk of TIPN.
RESULTS:
Five genes had a p-value < 10-4 for grade 3-4 TIPN analysis and three genes had a p-value < 10-4 for the grade 2-4 TIPN analysis. For the grade 3-4 TIPN analysis, SET binding factor 2 (SBF2) was significantly associated with TIPN (p-value=4.35 x10-6). Five variants were predicted to be deleterious in SBF2. Inherited mutations in SBF2 have previously been associated with autosomal recessive, Type 4B2 Charcot-Marie-Tooth (CMT) disease.
CONCLUSION:
Rare variants in SBF2, a CMT gene, predict an increased risk of TIPN in AA patients receiving paclitaxel
Double-Blind Phase III Trial of Adjuvant Chemotherapy With and Without Bevacizumab in Patients With Lymph Node-Positive and High-Risk Lymph Node-Negative Breast Cancer (E5103)
Purpose Bevacizumab improves progression-free survival but not overall survival in patients with metastatic breast cancer. E5103 tested the effect of bevacizumab in the adjuvant setting in patients with human epidermal growth factor receptor 2-negative disease. Patients and Methods Patients were assigned 1:2:2 to receive placebo with doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (arm A), bevacizumab only during AC and paclitaxel (arm B), or bevacizumab during AC and paclitaxel followed by bevacizumab monotherapy for 10 cycles (arm C). Random assignment was stratified and bevacizumab dose adjusted for choice of AC schedule. Radiation and hormonal therapy were administered concurrently with bevacizumab in arm C. The primary end point was invasive disease-free survival (IDFS). Results Four thousand nine hundred ninety-four patients were enrolled. Median age was 52 years; 64% of patients were estrogen receptor positive, 27% were lymph node negative, and 78% received dose-dense AC. Chemotherapy-associated adverse events including myelosuppression and neuropathy were similar across all arms. Grade ≥ 3 hypertension was more common in bevacizumab-treated patients, but thrombosis, proteinuria, and hemorrhage were not. The cumulative incidence of clinical congestive heart failure at 15 months was 1.0%, 1.9%, and 3.0% in arms A, B, and C, respectively. Bevacizumab exposure was less than anticipated, with approximately 24% of patients in arm B and approximately 55% of patients in arm C discontinuing bevacizumab before completing planned therapy. Five-year IDFS was 77% (95% CI, 71% to 81%) in arm A, 76% (95% CI, 72% to 80%) in arm B, and 80% (95% CI, 77% to 83%) in arm C. Conclusion Incorporation of bevacizumab into sequential anthracycline- and taxane-containing adjuvant therapy does not improve IDFS or overall survival in patients with high-risk human epidermal growth factor receptor 2-negative breast cancer. Longer duration bevacizumab therapy is unlikely to be feasible given the high rate of early discontinuation
Poly(ADP-Ribose) Polymerase Inhibition: "Targeted" Therapy for Triple-Negative Breast Cancer
In contrast to endocrine-sensitive and HER2-positive breast cancer, novel agents capable of treating advanced triple negative breast cancer (TNBC) are lacking. PARP (Poly-(adenosine diphosphate [ADP]-ribose) polymerase) inhibitors are emerging as one of the most promising ‘targeted’ therapeutics to treat TNBC, with the intended ‘target’ being DNA repair. PARP's are a family of enzymes involved in multiple cellular processes including DNA repair. TNBC shares multiple clinico-pathologic features with BRCA-mutated breast cancers which harbor dysfunctional DNA repair mechanisms. Investigators hypothesized PARP inhibition, in conjunction with the loss of DNA-repair via BRCA-dependent mechanisms, would result in synthetic lethality and augmented cell death. This hypothesis has borne out in both preclinical models and in clinical trials testing PARP inhibitors in both BRCA-deficient and TNBC. The focus of this review will include an overview of the preclinical rationale for evaluating PARP inhibitors in TNBC, the presumed mechanism of action of this novel therapeutic class, promising results from several influential clinical trials of PARP inhibition in advanced breast cancer (both TNBC and BRCA-deficient), proposed mechanisms of acquired resistance to PARP inhibitors, and, finally, conclude with current challenges and future directions for the development of PARP inhibitors in the treatment of breast cancer
Prognostic Value of Tumor-Infiltrating Lymphocytes in Triple-Negative Breast Cancers From Two Phase III Randomized Adjuvant Breast Cancer Trials: ECOG 2197 and ECOG 1199
Purpose
Recent studies suggest that tumor-infiltrating lymphocytes (TILs) are associated with disease-free (DFS) and overall survival (OS) in operable triple-negative breast cancer (TNBC). We seek to validate the prognostic impact of TILs in primary TNBCs in two adjuvant phase III trials conducted by the Eastern Cooperative Oncology Group (ECOG).
Patients and Methods
Full-face hematoxylin and eosin–stained sections of 506 tumors from ECOG trials E2197 and E1199 were evaluated for density of TILs in intraepithelial (iTILs) and stromal compartments (sTILs). Patient cases of TNBC from E2197 and E1199 were randomly selected based on availability of sections. For the primary end point of DFS, association with TIL scores was determined by fitting proportional hazards models stratified on study. Secondary end points were OS and distant recurrence–free interval (DRFI). Reporting recommendations for tumor marker prognostic studies criteria were followed, and all analyses were prespecified.
Results
The majority of 481 evaluable cancers had TILs (sTILs, 80%; iTILs, 15%). With a median follow-up of 10.6 years, higher sTIL scores were associated with better prognosis; for every 10% increase in sTILs, a 14% reduction of risk of recurrence or death (P = .02), 18% reduction of risk of distant recurrence (P = .04), and 19% reduction of risk of death (P = .01) were observed. Multivariable analysis confirmed sTILs to be an independent prognostic marker of DFS, DRFI, and OS.
Conclusion
In two national randomized clinical trials using contemporary adjuvant chemotherapy, we confirm that stromal lymphocytic infiltration constitutes a robust prognostic factor in TNBCs. Studies assessing outcomes and therapeutic efficacies should consider stratification for this parameter
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