Myogenic Differentiation of Mouse Embryonic Stem Cells That Lack a Functional Pax7 Gene

The transcription factor Pax7 plays a key role during embryonic myogenesis and sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Overexpression of Pax7 has been shown to promote the myogenic differentiation of pluripotent stem cells. However, the effects of the absence of functional Pax7 in differentiating embryonic stem cells (ESCs) have not yet been directly tested. Herein, we studied mouse stem cells that lacked a functional Pax7 gene and characterized the differentiation of these stem cells under conditions that promoted the derivation of myoblasts in vitro. We analyzed the expression of myogenic factors, such as myogenic regulatory factors and muscle-specific microRNAs, in wild-type and mutant cells. Finally, we compared the transcriptome of both types of cells and did not find substantial differences in the expression of genes related to the regulation of myogenesis. As a result, we showed that the absence of functional Pax7 does not prevent the in vitro myogenic differentiation of ESCs

Zoonotic Viruses in Three Species of Voles from Poland

Rodents are known to be reservoir hosts for a plethora of zoonotic viruses and therefore play a significant role in the dissemination of these pathogens. We trapped three vole species (Microtus arvalis, Alexandromys oeconomus and Microtus agrestis) in northeastern Poland, all of which are widely distributed species in Europe. Using immunofluorescence assays, we assessed serum samples for the presence of antibodies to hantaviruses, arenaviruses and cowpox viruses (CPXV). We detected antibodies against CPXV and Puumala hantavirus (PUUV), the overall seroprevalence of combined viral infections being 18.2% [10.5–29.3] and mostly attributed to CPXV. We detected only one PUUV/TULV cross-reaction in Microtus arvalis (1.3% [0.1–7.9]), but found similar levels of antibodies against CPXV in all three vole species. There were no significant differences in seroprevalence of CPXV among host species and age categories, nor between the sexes. These results contribute to our understanding of the distribution and abundance of CPXV in voles in Europe, and confirm that CPXV circulates also in Microtus and Alexandromys voles in northeastern Poland

Cell cycle regulation of embryonic stem cells and mouse embryonic fibroblasts lacking functional Pax7

The transcription factor Pax7 plays a key role during embryonic myogenesis and in adult organisms in that it sustains the proper function of satellite cells, which serve as adult skeletal muscle stem cells. Recently we have shown that lack of Pax7 does not prevent the myogenic differentiation of pluripotent stem cells. In the current work we show that the absence of functional Pax7 in differentiating embryonic stem cells modulates cell cycle facilitating their proliferation. Surprisingly, deregulation of Pax7 function also positively impacts at the proliferation of mouse embryonic fibroblasts. Such phenotypes seem to be executed by modulating the expression of positive cell cycle regulators, such as cyclin E

Distinct Modulation of Spontaneous and GABA-Evoked Gating by Flurazepam Shapes Cross-Talk Between Agonist-Free and Liganded GABAA Receptor Activity

GABAA receptors (GABAARs) play a crucial inhibitory role in the CNS. Benzodiazepines (BDZs) are positive modulators of specific subtypes of GABAARs, but the underlying mechanism remains obscure. Early studies demonstrated the major impact of BDZs on binding and more recent investigations indicated gating, but it is unclear which transitions are affected. Moreover, the upregulation of GABAAR spontaneous activity by BDZs indicates their impact on receptor gating but the underlying mechanisms remain unknown. Herein, we investigated the effect of a BDZ (flurazepam) on the spontaneous and GABA-induced activity for wild-type (WT, α1β2γ2) and mutated (at the orthosteric binding site α1F64) GABAARs. Surprisingly, in spite of the localization at the binding site, these mutations increased the spontaneous activity. Flurazepam (FLU) upregulated this activity for mutants and WT receptors to a similar extent by affecting opening/closing transitions. Spontaneous activity affected GABA-evoked currents and is manifested as an overshoot after agonist removal that depended on the modulation by BDZs. We explain the mechanism of this phenomenon as a cross-desensitization of ligand-activated and spontaneously active receptors. Moreover, due to spontaneous activity, FLU-pretreatment and co-application (agonist + FLU) protocols yielded distinct results. We provide also the first evidence that GABAAR may enter the desensitized state in the absence of GABA in a FLU-dependent manner. Based on our data and model simulations, we propose that FLU affects agonist-induced gating by modifying primarily preactivation and desensitization. We conclude that the mechanisms of modulation of spontaneous and ligand-activated GABAAR activity concerns gating but distinct transitions are affected in spontaneous and agonist-evoked activity

Characteristics of the heart failure population in Poland: ZOPAN, a multicentre national programme

Background: It is difficult to define the optimal management of elderly heart failure (HF) patients with complex comorbidities. Thus, comprehensive characterisation of HF patients constitutes a crucial pre-condition for the successful management of this fragile population. Aim: To analyse the ‘real life’ HF patients, including the evaluation of their health conditions, management and their use of public health resources. Methods and results: We examined 822 consecutive patients diagnosed with HF in NYHA classes II–IV in primary care practices. The mean age was 68.5 years, and 56% were male. Only 23% of the patients who were of pre-retirement age remained professionally active. Ischaemic or hypertension aetiology was found in 90% of participants. Nearly all patients had multiple comorbidities. Most patients received converting enzyme inhibitors (88%) and beta-blockers (77%), 60% of them both, although dosing was frequently inadequate. During the six months preceding the study, 31% had cardiovascular hospitalisation and 66% required unscheduled surgery visits. Conclusions: The real life HF population differs from trial populations. Most of the real life patients who had not yet reached retirement age were professionally inactive, mainly due to a disability caused by cardiovascular conditions. Moreover, extremely few participants were free from any comorbidity. Compared to 20th century Polish data, there has been an improvement in the overall quality of HF-recommended pharmacotherapy. It must be stressed, however, that the percentage of those on optimal dosage remains unsatisfactory. Kardiol Pol 2011; 69, 1: 24-31Wstęp: Ustalenie optymalnego leczenia pacjentów w podeszłym wieku z niewydolnością serca (HF), którzy są obciążeni wieloma chorobami współistniejącymi, jest zagadnieniem szczególnie trudnym. Dlatego też podstawą skutecznego postępowania w tej grupie osób jest dokładna charakterystyka populacji. Cel: Celem pracy była analiza charakterystyki chorych z HF na podstawie codziennej praktyki lekarskiej, z oceną ich stanu zdrowia, jakości opieki oraz stopnia obciążenia dla systemu opieki zdrowotnej. Metody i wyniki: Do badania włączono 822 kolejnych pacjentów ambulatoryjnych z HF w II-IV klasie NYHA z ośrodków podstawowej opieki zdrowotnej. Średni wiek badanej grupy wynosił 68,5 roku, 56% stanowili mężczyźni, a 23% pacjentów w okresie przedemerytalnym pozostawała aktywna zawodowo. Etiologia niedokrwienna lub nadciśnienie tętnicze było wskazywane jako przyczyna HF w 90% przypadków. Choroby współistniejące stwierdzano u prawie wszystkich badanych osób. Większość pacjentów otrzymywała inhibitory enzymu konwertującego angiotensynę (88%), a 77% - beta-adrenolityki, z czego 60% chorych przyjmowało połączenie tych dwóch leków, przy czym ich dawkowanie było niższe od zalecanego. W okresie 6 miesięcy poprzedzających badanie 31% osób było hospitalizowanych z przyczyn sercowo-naczyniowych, a 66% wymagało dodatkowych, nieplanowanych wizyt lekarskich. Wnioski: Rzeczywisty obraz populacji chorych z HF różni się od opisywanego w badaniach klinicznych. Większość pacjentów w okresie przedemerytalnym była nieaktywna zawodowo, przede wszystkim z powodu chorób sercowo-naczyniowych. Dodatkowo brak chorób współistniejących stwierdzano jedynie u niewielkiego odsetka osób. W porównaniu z poprzednimi danymi w przypadku populacji polskiej poprawiła się jakość opieki nad chorymi z HF w odniesieniu do stosowanej farmakoterapii, nadal jednak dawkowanie leków odbiega od standardów. Kardiol Pol 2011; 69, 1: 24-3

Impact of Semantic Relatedness on Associative Memory: An ERP Study

Encoding and retrieval processes in memory for pairs of pictures are thought to be influenced by inter-item similarity and by features of individual items. Using Event-Related Potentials (ERP), we aimed to identify how these processes impact on both the early mid-frontal FN400 and the Late Positive Component (LPC) potentials during associative retrieval of pictures. Twenty young adults undertook a sham task, using an incidental encoding of semantically related and unrelated pairs of drawings. At test, we conducted a recognition task in which participants were asked to identify target identical pairs of pictures, which could be semantically related or unrelated, among new and rearranged pairs. We observed semantic (related and unrelated pairs) and condition effects (old, rearranged and new pairs) on the early mid-frontal potential. First, a lower amplitude was shown for identical and rearranged semantically related pairs, which might reflect a retrieval process driven by semantic cues. Second, among semantically unrelated pairs, we found a larger negativity for identical pairs, compared to rearranged and new ones, suggesting additional retrieval processing that focuses on associative information. We also observed an LPC old/new effect with a mid-parietal and a right occipito-parietal topography for semantically related and unrelated old pairs, demonstrating a recollection phenomenon irrespective of the degree of association. These findings suggest that associative recognition using visual stimuli begins at early stages of retrieval, and differs according to the degree of semantic relatedness among items. However, either strategy may ultimately lead to recollection processes

Identification and functional characterization of pVHL-dependent cell surface proteins in renal cell carcinoma

The identification of cell surface accessible biomarkers enabling diagnosis, disease monitoring, and treatment of renal cell carcinoma (RCC) is as challenging as the biology and progression of RCC is unpredictable. A hallmark of most RCC is the loss-of-function of the von Hippel-Lindau (pVHL) protein by mutation of its gene (VHL). Using the cell surface capturing (CSC) technology, we screened and identified cell surface N-glycoproteins in pVHL-negative and positive 786-O cells. One hundred six cell surface N-glycoproteins were identified. Stable isotope labeling with amino acids in cell culture-based quantification of the CSC screen revealed 23 N-glycoproteins whose abundance seemed to change in a pVHL-dependent manner. Targeted validation experiments using transcriptional profiling of primary RCC samples revealed that nine glycoproteins, including CD10 and AXL, could be directly linked to pVHL-mediated transcriptional regulation. Subsequent human tumor tissue analysis of these cell surface candidate markers showed a correlation between epithelial AXL expression and aggressive tumor phenotype, indicating that pVHL-dependent regulation of glycoproteins may influence the biologic behavior of RCC. Functional characterization of the metalloprotease CD10 in cell invasion assays demonstrated a diminished penetrating behavior of pVHL-negative 786-O cells on treatment with the CD10-specific inhibitor thiorphan. Our proteomic surfaceome screening approach in combination with transcriptional profiling and functional validation suggests pVHL-dependent cell surface glycoproteins as potential diagnostic markers for therapeutic targeting and RCC patient monitoring

Sex- and age-related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long-Term Registry

Aims: This study aimed to assess age- and sex-related differences in management and 1-year risk for all-cause mortality and hospitalization in chronic heart failure (HF) patients. Methods and results: Of 16 354 patients included in the European Society of Cardiology Heart Failure Long-Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline-directed medical therapy (GDMT) were high (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P\ua0 64 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1-year follow-up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all-cause mortality were lower in women than in men (7.1% vs. 8.7%; P\ua0=\ua00.015), as were rates of all-cause hospitalization (21.9% vs. 27.3%; P\ua075 years. Conclusions: There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all-cause mortality in patients with LVEF 6445%