Gene loss, thermogenesis, and the origin of birds.

Compared to related taxa, birds have exceptionally enlarged and diversified skeletal muscles, features that are closely associated with skeletal diversification and are commonly explained by a diversity of avian ecological niches and locomotion types. The thermogenic muscle hypothesis (TMH) for the origin of birds proposes that such muscle hyperplasia and the associated skeletal innovations are instead the consequence of the avian clade originating from an ancestral population that underwent several successive episodes of loss of genes associated with thermogenesis, myogenesis, and skeletogenesis. Direct bird ancestors met this challenge with a combination of behavioral strategies (e.

The histone methyltransferase inhibitor BIX01294 enhances the cardiac potential of bone marrow cells.

Bone marrow (BM) has long been considered a potential stem cell source for cardiac repair due to its abundance and accessibility. Although previous investigations have generated cardiomyocytes from BM, yields have been low, and far less than produced from ES or induced pluripotent stem cells (iPSCs). Since differentiation of pluripotent cells is difficult to control, we investigated whether BM cardiac competency could be enhanced without making cells pluripotent.

Inhibition of heart formation by lithium is an indirect result of the disruption of tissue organization within the embryo.

Lithium is a commonly used drug for the treatment of bipolar disorder. At high doses, lithium becomes teratogenic, which is a property that has allowed this agent to serve as a useful tool for dissecting molecular pathways that regulate embryogenesis. This study was designed to examine the impact of lithium on heart formation in the developing frog for insights into the molecular regulation of cardiac specification.

GATA6 reporter gene reveals myocardial phenotypic heterogeneity that is related to variations in gap junction coupling.

This study examined transgenic mice whose expression of a β-galactosidase (lacZ) reporter is driven by a GATA6 gene enhancer. Previous investigations established that transcription of the transgene was associated with precardiac mesoderm and primary heart tube myocardium, which decreased progressively, so that its expression was no longer observed within ventricular myocardium by midgestation. Expression of this reporter in the adult was investigated for insights into myocyte homeostasis and cardiovascular biology.

Canonical WNT signaling enhances stem cell expression in the developing heart without a corresponding inhibition of cardiogenic differentiation.

WNT signaling has been shown to influence the development of the heart. Although recent data suggested that canonical WNTs promote the emergence and expansion of cardiac progenitors in the pregastrula embryo, it has long been accepted that once gastrulation begins, canonical WNT signaling needs to be suppressed for cardiac development to proceed. Yet, this latter supposition appears to be odds with the expression of multiple canonical WNTs in the developing heart.

Cell state switching factors and dynamical patterning modules: complementary mediators of plasticity in development and evolution.

Ancient metazoan organisms arose from unicellular eukaryotes that had billions of years of genetic evolution behind them. The transcription factor networks present in single-celled ancestors at the origin of the Metazoa (multicellular animals) were already capable of mediating the switching of the unicellular phenotype among alternative states of gene activity in response to environmental conditions. Cell differentiation, therefore, had its roots in phenotypic plasticity, with the ancient regulatory proteins acquiring new targets over time and evolving into the "developmental transcription factors" (DTFs) of the "developmental-genetic toolkit.

The brown adipocyte differentiation pathway in birds: an evolutionary road not taken.

Background: Thermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common white fat adipocytes by having numerous small lipid droplets rather than a single large one, elevated numbers of mitochondria, and mitochondrial expression of the nuclear gene UCP1, the uncoupler of oxidative phosphorylation responsible for non-shivering thermogenesis.

Results: We have identified in vitro inductive conditions in which mesenchymal cells isolated from the embryonic chicken limb bud differentiate into avian brown adipocyte-like cells (ABALCs) with the morphological and many of the biochemical properties of terminally differentiated brown adipocytes.

[The antiaggregation activity of the vascular wall in patients suffering from arterial hypertension with metabolic syndrome].

The subjects of the study were patients suffering from arterial hypertension with metabolic syndrome; the study found that thrombocyte aggregation function was intensified, while the antiaggregation activity of the vascular wall was weakened in these patients. The mentioned changes are underlied by deep alterations in lipid exchange, the activation of serum lipid peroxidation, and disturbances in the synthesis of prostacycline in the vascular wall, associated with the intensification of thromboxane formation in the platelets.

Superoxide radical anions on the surface of zirconia and sulfated zirconia: formation mechanisms, properties and structure.

In situ ESR spectroscopy has been used for direct comparison of different thermal and light-induced processes leading to generation of superoxide radical anions on the surface of various zirconia and sulfated zirconia materials. For materials of both types the magnetic resonance parameters of the radical anions were found to be practically independent of the generation method, except for oxygen coadsorption with NO that yields radicals with somewhat smaller gz values. The parameters appear to depend mostly on the state of the surface zirconia cations stabilizing the radical anions, so that the g tensor anisotropy is significantly smaller over sulfated zirconia.

[Physical activity and work capacity of patients in the late periods after the surgical correction of pulmonary stenosis].

From analysis of the data on the physical activity and working capacity of 162 patients with valvular stenosis of the pulmonary artery and tetraology of Fallot before and after correction of the anomaly, it was found that only 26.5% of patients have good physical resources before operation. In the late periods after effective correction of the defect in all grades of stenosis and even in secondary stenosis of the right conus arteriosus, reverse dynamics of functional disorders occurs and high physical activity is restored in more than 90% of patients.

[Clinical diagnosis and prognosis of the course of congenital heart defects with pulmonary stenosis].

An analysis of 433 observations is presented (164 cases of isolated pulmonary stenosis, 132 cases of its combination with atrial septal defect, and 137--with ventricular septal defect), the patients being 1 year 1 month to 36 years old, and the form of their heart disease being verified during surgery on a "dry" heart. The mentioned diseases were classified into 3 groups according to the tactical importance of the pulmonary stenosis. Haemodynamic studies in patients with pulmonary stenosis and an intact ventricular septum have demonstrated that with age right-ventricular hypertension progresses the faster the greater the pulmonary artery valve is stenosed.