582 research outputs found
Whence Directionality: Guidance Mechanisms in Solitary and Collective Cell Migration
As individual cells or groups of cells move through the complex environment of the body, their migration is affected by multiple external cues. Some cues are diffusible signaling molecules, and some are solid biophysical features. How do cells respond appropriately? This perspective discusses the relationship between guidance input and the cellular output, considering effects from classical chemotaxis to contact-dependent guidance. The influences of membrane trafficking and of imposed constraints on directional movement are also considered. New insights regarding guidance and dynamic cell polarity have emerged from examining new cell migration models and from re-examining well known ones with new approaches and new tools
Regulatory mechanisms required for DE-cadherin function in cell migration and other types of adhesion
Cadherin-mediated adhesion can be regulated at many levels, as demonstrated by detailed analysis in cell lines. We have investigated the requirements for Drosophila melanogaster epithelial (DE) cadherin regulation in vivo. Investigating D. melanogaster oogenesis as a model system allowed the dissection of DE-cadherin function in several types of adhesion: cell sorting, cell positioning, epithelial integrity, and the cadherin-dependent process of border cell migration. We generated multiple fusions between DE-cadherin and α-catenin as well as point-mutated β-catenin and analyzed their ability to support these types of adhesion. We found that (1) although linking DE-cadherin to α-catenin is essential, regulation of the link is not required in any of these types of adhesion; (2) β-catenin is required only to link DE-cadherin to α-catenin; and (3) the cytoplasmic domain of DE-cadherin has an additional specific function for the invasive migration of border cells, which is conserved to other cadherins. The nature of this additional function is discussed
Binding site for p120/δ-catenin is not required for Drosophila E-cadherin function in vivo
Homophilic cell adhesion mediated by classical cadherins is important for many developmental processes. Proteins that interact with the cytoplasmic domain of cadherin, in particular the catenins, are thought to regulate the strength and possibly the dynamics of adhesion. β-catenin links cadherin to the actin cytoskeleton via α-catenin. The role of p120/δ-catenin proteins in regulating cadherin function is less clear. Both β-catenin and p120/δ-catenin are conserved in Drosophila. Here, we address the importance of cadherin–catenin interactions in vivo, using mutant variants of Drosophila epithelial cadherin (DE-cadherin) that are selectively defective in p120ctn (DE-cadherin-AAA) or β-catenin–armadillo (DE-cadherin-Δβ) interactions. We have analyzed the ability of these proteins to substitute for endogenous DE-cadherin activity in multiple cadherin-dependent processes during Drosophila development and oogenesis; epithelial integrity, follicle cell sorting, oocyte positioning, as well as the dynamic adhesion required for border cell migration. As expected, DE-cadherin-Δβ did not substitute for DE-cadherin in these processes, although it retained some residual activity. Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations. Thus, interaction with p120/δ-catenin does not appear to be required for DE-cadherin function in vivo
Anticoagulation therapy in heart failure and sinus rhythm: a systematic review and meta-analysis
Objective: Heart failure is a prothrombotic state, and it has been hypothesised that thrombosis and embolism cause non-fatal and fatal events in heart failure and reduced ejection fraction (HFrEF). We sought to determine the effect of anticoagulant therapy on clinical outcomes in patients with HFrEF who are in sinus rhythm.
Methods: We conducted an updated systematic review and meta-analysis to examine the effect of anticoagulation therapy in patients with HFrEF in sinus rhythm. Our analysis compared patients randomised to anticoagulant therapy with those randomised to antiplatelet therapy, placebo or control, and examined the endpoints of all-cause mortality, (re)hospitalisation for worsening heart failure, non-fatal myocardial infarction, non-fatal stroke of any aetiology and major haemorrhage.
Results: Five trials were identified that met the prespecified search criteria. Compared with control therapy, anticoagulant treatment did not reduce all-cause mortality (risk ratio [RR] 0.99, 95% CI 0.90 to 1.08), (re)hospitalisation for heart failure (RR 0.97, 95% CI 0.82 to 1.13) or non-fatal myocardial infarction (RR 0.92, 95% CI 0.75 to 1.13). Anticoagulation did reduce the rate of non-fatal stroke (RR 0.63, 95% CI 0.49 to 0.81, p=0.001), but this was offset by an increase in the incidence of major haemorrhage (RR 1.88, 95% CI 1.49 to 2.38, p=0.001).
Conclusions: Our meta-analysis provides evidence to oppose the hypothesis that thrombosis or embolism plays an important role in the morbidity and mortality associated with HFrEF, with the exception of stroke-related morbidity
Cell behaviors regulated by guidance cues in collective migration of border cells
The PDGF/VEGF-related receptor and the EGF receptor control the direction of collective cell migration by regulating the persistence and productivity of protrusions
Return to the workforce following first hospitalization for heart failure: a Danish nationwide cohort study
Background: Return to work is important financially, as a marker of functional status and for self-esteem in patients developing chronic illness. We examined return to work after first heart failure (HF) hospitalization.
Methods: By individual-level linkage of nationwide Danish registries, we identified 21455 patients of working age (18-60 years) with a first HF hospitalization in the period of 1997-2012. Of these 11880 (55%) were in the workforce prior to HF hospitalization and comprised the study population. We applied logistic regression to estimate odds ratios (OR) for associations between age, sex, length of hospital stay, level of education, income, comorbidity and return to work.
Results: One year after first HF hospitalization, 8040 (67.7%) returned to the workforce, 2981 (25.1%) did not, 805 (6.7%) died and 54 (0.5%) emigrated. Predictors of return to work included younger age (18-30 vs. 51-60 years, OR 3.12; 95% CI 2.42-4.03), male sex (OR 1.22 [1.18-1.34]) and level of education (long-higher vs. basic school OR 2.06 [1.63-2.60]). Conversely, hospital stay >7 days (OR 0.56 [0.51-0.62]) and comorbidity including history of stroke (OR 0.55 [0.45-0.69]), chronic kidney disease (OR 0.46 [0.36-0.59]), chronic obstructive pulmonary disease (OR 0.62 [0.52-0.75]), diabetes (OR 0.76 [0.68-0.85]) and cancer (OR 0.49 [0.40-0.61]) were all significantly associated with lower chance of return to work.
Conclusions: Patients in the workforce prior to HF hospitalization had low mortality but high risk of detachment from the workforce one year later. Young age, male sex, and higher level of education were predictors of return to work
Progressive Resistance Training and Cancer Testis (PROTRACT) - Efficacy of resistance training on muscle function, morphology and inflammatory profile in testicular cancer patients undergoing chemotherapy: design of a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Standard treatment for patients with disseminated germ cell tumors is combination chemotherapy with bleomycin, etoposide and cisplatin (BEP). This treatment is highly effective, but the majority of patients experience severe adverse effects during treatment and are at risk of developing considerable long-term morbidity, including second malignant neoplasms, cardiovascular disease, and pulmonary toxicity. One neglected side effect is the significant muscular fatigue mentioned by many patients with testicular cancer both during and after treatment. Very limited information exists concerning the patho-physiological effects of antineoplastic agents on skeletal muscle. The primary aim of this study is to investigate the effects of BEP-treatment on the skeletal musculature in testicular cancer patients, and to examine whether the expected treatment-induced muscular deterioration can be attenuated or even reversed by high intensity progressive resistance training (HIPRT).</p> <p>Design/Methods</p> <p>The PROTRACT study is a randomized controlled trial in 30 testicular cancer patients undergoing three cycles of BEP chemotherapy. Participants will be randomized to either a 9-week HIPRT program (STR) initiated at the onset of treatment, or to standard care (UNT). 15 healthy matched control subjects (CON) will complete the same HIPRT program. All participants will take part in 3 assessment rounds (baseline, 9 wks, 21 wks) including muscle biopsies, maximum muscle strength tests, whole body DXA scan and blood samples. <it>Primary outcome</it>: mean fiber area and fiber type composition measured by histochemical analyses, satellite cells and levels of protein and mRNA expression of intracellular mediators of protein turnover. Secondary outcomes: maximum muscle strength and muscle power measured by maximum voluntary contraction and leg-extensor-power tests, body composition assessed by DXA scan, and systemic inflammation analyzed by circulating inflammatory markers, lipid and glucose metabolism in blood samples. Health related Quality of Life (QoL) will be assessed by validated questionnaires (EORTC QLQ-C30, SF-36).</p> <p>Discussion</p> <p>This study investigates the muscular effects of antineoplastic agents in testicular cancer patients, and furthermore evaluates whether HIPRT has a positive influence on side effects related to chemotherapy. A more extensive knowledge of the interaction between cytotoxic-induced physiological impairment and exercise-induced improvement is imperative for the future development of optimal rehabilitation programs for cancer patients.</p> <p>Trial Registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN32132990">ISRCTN32132990</a>.</p
Effectiveness of community-based football compared to usual care in men with prostate cancer:Protocol for a randomised, controlled, parallel group, multicenter superiority trial (The FC Prostate Community Trial)
BACKGROUND: Prostate cancer is the most common non-cutaneous malignancy in men. Today most patients may expect to live years following the diagnosis and may thus experience significant morbidity due to disease progression and treatment toxicity. In order to address some of these problems exercise has been suggested and previously studies have shown improvements of disease specific quality of life and a reduction in treatment-related toxicity. Cohort studies with long term follow up have suggested that physical activity is associated with improved survival in prostate cancer patients. Previously one randomised controlled trial has examined the efficacy of football in prostate cancer patients undergoing androgen deprivation therapy to usual care and reported positive effects on lean body mass and bone markers. Against this background, we wish to examine the effectiveness of community-based football for men diagnosed with prostate cancer. METHODS: Using a randomised controlled parallel group, multicenter, superiority trial design, two hundred prostate cancer patients will be recruited and randomised (1:1) to either community-based football one hour twice weekly or to a control group. The intervention period will be six months. The primary outcome is quality of life assessed after 12 weeks based on the change from baseline in the Functional Assessment of Cancer Therapy–Prostate questionnaire. Secondary outcomes are change from baseline to six months in quality of life, lean body mass, fat mass, whole body and regional bone markers, as well as physical activity and functional capacity at 12 weeks and six months. Safety outcome variables will be falls resulting in seeking medical assessment and fractures during the six-month period. DISCUSSION: Football is viewed as a case for non-professional, supervised community-based team sport for promoting long-term physical activity in men diagnosed with prostate cancer. This randomised trial will provide data on effectiveness and safety for men with prostate cancer when football training is delivered in local football clubs. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT0243079
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