Free-algebra functors from a coalgebraic perspective

Given a set $\Sigma$ of equations, the free-algebra functor $F_{\Sigma}$ associates to each set $X$ of variables the free algebra $F_{\Sigma}(X)$ over $X$. Extending the notion of \emph{derivative} $\Sigma'$ for an arbitrary set $\Sigma$ of equations, originally defined by Dent, Kearnes, and Szendrei, we show that $F_\Sigma$ preserves preimages if and only if $\Sigma \vdash \Sigma'$, i.e. $\Sigma$ derives its derivative $\Sigma'$. If $F_\Sigma$ weakly preserves kernel pairs, then every equation $p(x,x,y)=q(x,y,y)$ gives rise to a term $s(x,y,z,u)$ such that $p(x,y,z)=s(x,y,z,z)$ and $q(x,y,z)=s(x,x,y,z)$. In this case n-permutable varieties must already be permutable, i.e. Mal'cev. Conversely, if $\Sigma$ defines a Mal'cev variety, then $F_\Sigma$ weakly preserves kernel pairs. As a tool, we prove that arbitrary $Set-$endofunctors $F$ weakly preserve kernel pairs if and only if they weakly preserve pullbacks of epis

A multi-gene signature predicts outcome in patients with pancreatic ductal adenocarcinoma.

© 2014 Haider et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Improved usage of the repertoires of pancreatic ductal adenocarcinoma (PDAC) profiles is crucially needed to guide the development of predictive and prognostic tools that could inform the selection of treatment options

Low NKp30, NKp46 and NKG2D expression and reduced cytotoxic activity on NK cells in cervical cancer and precursor lesions

<p>Abstract</p> <p>Background</p> <p>Persistent high risk HPV infection can lead to cervical cancer, the second most common malignant tumor in women worldwide. NK cells play a crucial role against tumors and virus-infected cells through a fine balance between activating and inhibitory receptors. Expression of triggering receptors NKp30, NKp44, NKp46 and NKG2D on NK cells correlates with cytolytic activity against tumor cells, but these receptors have not been studied in cervical cancer and precursor lesions. The aim of the present work was to study NKp30, NKp46, NKG2D, NKp80 and 2B4 expression in NK cells from patients with cervical cancer and precursor lesions, in the context of HPV infection.</p> <p>Methods</p> <p>NKp30, NKp46, NKG2D, NKp80 and 2B4 expression was analyzed by flow cytometry on NK cells from 59 patients with cervical cancer and squamous intraepithelial lesions. NK cell cytotoxicity was evaluated in a 4 hour CFSE/7-AAD flow cytometry assay. HPV types were identified by PCR assays.</p> <p>Results</p> <p>We report here for the first time that NK cell-activating receptors NKp30 and NKp46 are significantly down-regulated in cervical cancer and high grade squamous intraepithelial lesion (HGSIL) patients. NCRs down-regulation correlated with low cytolytic activity, HPV-16 infection and clinical stage. NKG2D was also down-regulated in cervical cancer patients.</p> <p>Conclusion</p> <p>Our results suggest that NKp30, NKp46 and NKG2D down-regulation represent an evasion mechanism associated to low NK cell activity, HPV-16 infection and cervical cancer progression.</p

T-cell metagene predicts a favorable prognosis in estrogen receptor-negative and HER2-positive breast cancers

Introduction: Lymphocyte infiltration (LI) is often seen in breast cancer but its importance remains controversial. A positive correlation of human epidermal growth factor receptor 2 (HER2) amplification and LI has been described, which was associated with a more favorable outcome. However, specific lymphocytes might also promote tumor progression by shifting the cytokine milieu in the tumor. Methods: Affymetrix HG-U133A microarray data of 1,781 primary breast cancer samples from 12 datasets were included. The correlation of immune system-related metagenes with different immune cells, clinical parameters, and survival was analyzed. Results: A large cluster of nearly 600 genes with functions in immune cells was consistently obtained in all datasets. Seven robust metagenes from this cluster can act as surrogate markers for the amount of different immune cell types in the breast cancer sample. An IgG metagene as a marker for B cells had no significant prognostic value. In contrast, a strong positive prognostic value for the T-cell surrogate marker (lymphocyte-specific kinase (LCK) metagene) was observed among all estrogen receptor (ER)-negative tumors and those ER-positive tumors with a HER2 overexpression. Moreover ER-negative tumors with high expression of both IgG and LCK metagenes seem to respond better to neoadjuvant chemotherapy. Conclusions: Precise definitions of the specific subtypes of immune cells in the tumor can be accomplished from microarray data. These surrogate markers define subgroups of tumors with different prognosis. Importantly, all known prognostic gene signatures uniformly assign poor prognosis to all ER-negative tumors. In contrast, the LCK metagene actually separates the ER-negative group into better or worse prognosis

Trophic macrophages in development and disease

Specialized phagocytes are found in the most primitive multicellular organisms. Their roles in homeostasis and in distinguishing self from non-self have evolved with the complexity of organisms and their immune systems. Equally important, but often overlooked, are the roles of macrophages in tissue development. As discussed in this Review, these include functions in branching morphogenesis, neuronal patterning, angiogenesis, bone morphogenesis and the generation of adipose tissue. In each case, macrophage depletion impairs the formation of the tissue and compromises its function. I argue that in several diseases, the unrestrained acquisition of these developmental macrophage functions exacerbates pathology. For example, macrophages enhance tumour progression and metastasis by affecting tumour-cell migration and invasion, as well as angiogenesis

Correlates of physical activity among 142,118 adolescents aged 12-15 years from 48 low- and middle-income countries

Physical inactivity is a serious public health concern in adolescents from low- and middle-income countries (LMICs). Despite this, only a few multinational studies has investigated correlates of physical activity (PA) in young adolescents in this part of the world. In this study, we identified physical activity correlates using data from the Global school-based Student Health Survey. In total, 142,118 adolescents from 48 LMICs [age 13.8±1.0 years; 49% girls) were included in the analyses. PA was assessed by the PACE+ Adolescent Physical Activity Measure and participants were dichotomised into those who do (60 minutes of moderate-vigorous PA every day of the week) and do not comply with the World Health Organization recommendations. We used multivariable logistic regression in order to assess the correlates. The prevalence of low PA was 15.3% (95%CI=14.5%-16.1%). Boys (OR=1.64; 95%CI=1.47-1.83) and those who participated in physical education for ≥5 days/week (OR=1.12; 95%CI=1.10-1.15) were more likely to meet PA guidelines, while adolescents with food insecurity (OR=0.85; 95%CI=0.80-0.90), low fruit and vegetable intake (OR=0.68; 95%CI=0.63-0.74), low parental support/monitoring (OR=0.68; 95%CI=0.62-0.74), no friends (OR=0.80; 95%CI=0.72-0.88), and who experienced bullying (OR=0.93; 95%CI=0.86-0.99) were less likely to have adequate levels of PA. There were a few variations in the correlates depending on country-income level. Our data indicate that in adolescents aged 12 to 15 years living in LMICs physical activity participation is a complex and multi-dimensional behavior determined by sociocultural, socio-economic, and policy-related factors. Longitudinal research is needed to confirm/refute the present findings

Sedentary behaviour and sleep problems among 42,489 community-dwelling adults in six low- and middle-income countries

There is a lack of multinational research investigating the association between sleep problems and sedentary behaviour. In this study, we investigated the relationship between the time spent sedentary during waking hours and sleep problems in six low- and middle-income countries. Cross-sectional, community-based data from the Study on Global Ageing and Adult Health survey were analysed. Adjusted logistic regression analyses were undertaken to explore the relationship between self-reported sleep problems (such as difficulties falling asleep, waking up frequently during the night or waking up too early in the morning) in the last 30 days and self-reported sedentary time (categorized as <4, 4 to <8, 8 to <11 or ≥11 hr/day). Among 42,489 individuals aged ≥18 years (mean age=43.8 ± 14.4 years; 50.1% women), those who were sedentary for 8 to <11 hr/day (n = 2,782) and ≥11 hr/day (n = 674) had a 1.61 (95% confidence interval =1.03-2.50) and 1.75 (95% confidence interval =1.17-2.62) times higher odds of having sleep problems, respectively, compared with those being sedentary for less than 4 hr per day (n = 24,637). The strongest associations were observed among those aged 50-64 years. The observed associations were independent of a wide range of sociodemographic factors, physical and mental health conditions and physical activity behaviour. Considering the social and occupational costs of sleep problems, it is important that future longitudinal research should consider the directionality of the data.status: publishe