743 research outputs found
Clinicopathological predictors of chemoresponsiveness in epithelial ovarian cancer: a preliminary institutional study
Objective: One-third of women with epithelial ovarian cancer are resistant to standard platinum-based chemotherapy, and insufficient data exist in predicting response to chemotherapy. We describe the clinical and pathological factors of patients with complete and incomplete response to treatment.
Method: In this retrospective study, data was reviewed from 75 medical charts of 243 patients with primary epithelial ovarian cancers as a preliminary study. All patients underwent chemotherapy and cytoreductive surgery for primary disease. Fifty-six patients had complete response (CR) to chemotherapy and 19 had incomplete response (IR). Fifty-eight and 17 patients had optimal and suboptimal cytoreductive surgery, respectively. Clinical and pathological factors were compared in patients with complete and incomplete response to treatment, and optimal and suboptimal surgery. Overall survival (OS), cancer-specific survival (CSS), and time to recurrence (TTR) were estimated using the Kaplan-Meier method for patient groups.
Results: The majority of patients in both the CR and IR groups were diagnosed at advanced stage ovarian cancer. The CR group had significantly lower preoperative CA125 and was more likely to have optimal chemotherapy. The CR group was also more likely to have lymph nodes removed during cytoreductive surgery. A significantly lower percentage of CR patients died from the disease and had statistically longer disease free survival. Patients who underwent suboptimal surgery had significantly shorter survival, but no difference existed in the time until recurrence between patients with optimal and suboptimal surgery. OS, CSS, and TTR were significantly increased in the CR group and in patients that had optimal surgery.
Conclusion: Complete response during treatment and optimal surgery significantly increases OS, CSS, and TTR. Preoperative CA125 and lymph node removal during surgery may be predictive of complete treatment response
Automated Rendezvous and Docking Using Tethered Formation Flight
This paper analyzes capture strategies for tether-based autonomous rendezvous and docking. Once both spacecrafts are connected by tethers, docking is achieved through the use of reaction wheels and tether motors without the use of propellant. Autonomous rendezvous and docking is crucial for many upcoming missions including on-orbit servicing and potential Mars missions. The tether-based capture strategies investigated are a spin-up tether deployment and a free-flying child spacecraft attaching the tether. These strategies are compared to a traditional two-agent propulsive docking strategy. The capture strategies are simulated from initial orbit through to completed dock, with the total fuel consumption and dock time compared, along with initial pointing/location requirements. In addition to having lower fuel cost, the tether-based strategies are also more reliable due to redundancy, since tethers can be reeled back in and multiple tethers can be stored for use in case of primary tether failure
Autonomous In-Orbit Satellite Assembly from a Modular Heterogeneous Swarm
This paper presents a decentralized, distributed guidance and control scheme to combine a heterogeneous swarm of component satellites into a large satellite structure. The component satellites for the heterogeneous swarm are chosen to promote flexibility in final shape inspired by crystal structures and Islamic tile art. After the ideal fundamental building blocks are selected, basic nanosatellite-class satellite designs are made to assist in simulations involving attitude control. The Swarm Orbital Construction Algorithm (SOCA) is a guidance and control algorithm to allow for the limited type heterogeneity and docking ability required for in-orbit assembly. The algorithm consists of two parts, a distributed auction which uses barrier functions to ensure the proper agent selection for each target, and a trajectory generation portion which leverages model predictive control and sequential convex programming to achieve optimal collision-free trajectories to the desired target point even with nonlinear system dynamics. The optimization constraints use a boundary layer to determine whether the collision avoidance or the docking constraints should be applied. The algorithm was tested in a simulated perturbed 6-DOF spacecraft dynamic environment for planar and out-of-plane final structures and on two robotic platforms, including a swarm of frictionless spacecraft simulation robots
Dual trigger protocol is an effective IVF strategy in both normal and high responders without compromising pregnancy outcomes
To compare pregnancy outcomes between normal versus high responders after dual trigger of final oocyte maturation with gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG) in fresh in-vitro fertilization (IVF) cycles, where ovarian stimulation was achieved by a flexible GnRH antagonist protocol
Marital Status as an Independent Predictor of Event-Free Survival of Patients with Heart Failure
Background: Depressive symptoms are a well-known predictor of mortality in patients with heart failure, and positive spousal support is associated with improved outcomes in these patients. However, in the context of depressive symptoms, the effect on survival of having a spouse is unknown.
Objective: To determine the effect of marital status on event-free survival in patients with heart failure who did or did not have depressive symptoms.
Methods: Depressive symptoms were assessed by using the Back Depression Inventory-II in patients with heart failure who were followed-up for up to 4 years to collect data on mortality and hospitalizations. Patients were grouped according to the presence and absence of depressive symptoms by using the standard cutoff score of 14 on the Beck Depression Inventory-II. Kaplan-Meier and Cox regression analyses were used to compare event-free survival for married and nonmarried patients who were stratified according to the presence or absence of depressive symptoms.
Results: Of 166 patients, 56% were married, and 33% had depressive symptoms. Levels of depressive symptoms were similar between married and nonmarried patients (10.9 vs 12.1; P=.39). Married patients experienced longer event-free survival than did nonmarried patients (P=.01).
Conclusions: Patients with a spouse had longer event-free survival than nonmarried patients did, even in the context of depressive symptoms
Resistance loci affecting distinct stages of fungal pathogenesis: use of introgression lines for QTL mapping and characterization in the maize - Setosphaeria turcica pathosystem
<p>Abstract</p> <p>Background</p> <p>Studies on host-pathogen interactions in a range of pathosystems have revealed an array of mechanisms by which plants reduce the efficiency of pathogenesis. While R-gene mediated resistance confers highly effective defense responses against pathogen invasion, quantitative resistance is associated with intermediate levels of resistance that reduces disease progress. To test the hypothesis that specific loci affect distinct stages of fungal pathogenesis, a set of maize introgression lines was used for mapping and characterization of quantitative trait loci (QTL) conditioning resistance to <it>Setosphaeria turcica</it>, the causal agent of northern leaf blight (NLB). To better understand the nature of quantitative resistance, the identified QTL were further tested for three secondary hypotheses: (1) that disease QTL differ by host developmental stage; (2) that their performance changes across environments; and (3) that they condition broad-spectrum resistance.</p> <p>Results</p> <p>Among a set of 82 introgression lines, seven lines were confirmed as more resistant or susceptible than B73. Two NLB QTL were validated in BC<sub>4</sub>F<sub>2 </sub>segregating populations and advanced introgression lines. These loci, designated <it>qNLB1.02 </it>and <it>qNLB1.06</it>, were investigated in detail by comparing the introgression lines with B73 for a series of macroscopic and microscopic disease components targeting different stages of NLB development. Repeated greenhouse and field trials revealed that <it>qNLB1.06<sub>Tx303 </sub></it>(the Tx303 allele at bin 1.06) reduces the efficiency of fungal penetration, while <it>qNLB1.02<sub>B73 </sub></it>(the B73 allele at bin 1.02) enhances the accumulation of callose and phenolics surrounding infection sites, reduces hyphal growth into the vascular bundle and impairs the subsequent necrotrophic colonization in the leaves. The QTL were equally effective in both juvenile and adult plants; <it>qNLB1.06<sub>Tx303 </sub></it>showed greater effectiveness in the field than in the greenhouse. In addition to NLB resistance, <it>qNLB1.02<sub>B73 </sub></it>was associated with resistance to Stewart's wilt and common rust, while <it>qNLB1.06<sub>Tx303 </sub></it>conferred resistance to Stewart's wilt. The non-specific resistance may be attributed to pleiotropy or linkage.</p> <p>Conclusions</p> <p>Our research has led to successful identification of two reliably-expressed QTL that can potentially be utilized to protect maize from <it>S. turcica </it>in different environments. This approach to identifying and dissecting quantitative resistance in plants will facilitate the application of quantitative resistance in crop protection.</p
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REDUCE-IT USA: Results From the 3146 Patients Randomized in the United States.
BackgroundSome trials have found that patients from the United States derive less benefit than patients enrolled outside the United States. This prespecified REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl - Intervention Trial) subgroup analysis was conducted to determine the degree of benefit of icosapent ethyl in the United States.MethodsREDUCE-IT randomized 8179 statin-treated patients with qualifying triglycerides ≥135 and <500 mg/dL and low-density lipoprotein cholesterol >40 and ≤100 mg/dL and a history of atherosclerosis or diabetes mellitus to icosapent ethyl 4 g/d or placebo. The primary composite end point was cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina. The key secondary composite end point was cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. A hierarchy was prespecified for examination of individual and composite end points.ResultsA total of 3146 US patients (38.5% of the trial) were randomized and followed for a median of 4.9 years; 32.3% were women and 9.7% were Hispanic. The primary composite end point occurred in 24.7% of placebo-treated patients versus 18.2% of icosapent ethyl-treated patients (hazard ratio [HR], 0.69 [95% CI, 0.59-0.80]; P=0.000001); the key secondary composite end point occurred in 16.6% versus 12.1% (HR, 0.69 [95% CI, 0.57-0.83]; P=0.00008). All prespecified hierarchical end points were meaningfully and significantly reduced, including cardiovascular death (6.7% to 4.7%; HR, 0.66 [95% CI, 0.49-0.90]; P=0.007), myocardial infarction (8.8% to 6.7%; HR, 0.72 [95% CI, 0.56-0.93]; P=0.01), stroke (4.1% to 2.6%; HR, 0.63 [95% CI, 0.43-0.93]; P=0.02), and all-cause mortality (9.8% to 7.2%; HR, 0.70 [95% CI, 0.55-0.90]; P=0.004); for all-cause mortality in the US versus non-US patients, Pinteraction=0.02. Safety and tolerability findings were consistent with the full study cohort.ConclusionsWhereas the non-US subgroup showed significant reductions in the primary and key secondary end points, the US subgroup demonstrated particularly robust risk reductions across a variety of individual and composite end points, including all-cause mortality.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT01492361
A predictive model for serous epithelial ovarian cancer chemo-response using clinical characteristics
One of the prognostic factors most highly associated with ovarian cancer survival is response to initial chemotherapy. Current prediction models of chemo-response built with comprehensive molecular datasets, like The Cancer Genome Atlas (TCGA), could be improved by including clinical and outcomes data designed to study response to treatment. The objective of this study was to create a prediction model of ovarian cancer chemo-response using clinical-pathological features, and to compare its performance with a similar TCGA clinical model
Depressive symptoms and poor social support have a synergistic effect on event-free survival in patients with heart failure
Depressive symptoms and poor social support are predictors of increased morbidity and mortality in patients with heart failure (HF). However, the combined contribution of depressive symptoms and social support event-free survival of patients with HF has not been examined
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