Lumbosacral plexus in Brazilian Common Opossum

The opossum has been suggested as an animal model for biomedical studies due to its adaptability to captivity and number of births per year. Despite many studies on morphology and experimental neurology using this opossum model, the literature does not offer details of the nerves of the lumbosacral plexus in this species. Ten lumbosacral plexus were dissected to describe the peripheral innervations of the Brazilian Common Opossum (Didelphis aurita) and compare the results with Eutheria clade species. The tensor fasciae latae muscle was absent and there was only one sartorius muscle for each limb. The distribution of the nerves were similar to other mammals, except for the caudal gluteal nerve, sartorius muscle innervations and the position of the pudendal nerve which arose from the major ischiatic foramen together with the ischiatic nerve, the cranial gluteal nerve and the caudal gluteal nerve. No anatomical variation was found. The special position of the pudendal nerve suggested that the Brazilian Common Opossum is a better model than rats or rabbits in surgical procedures with that specific nerve. In addition, the study revealed that the pelvic limb nerves are not an invariable structure of reference for muscle homology and homonym as reported previously. New investigation using other species of opossums are necessary to best comprehend the lumbosacral plexus distribution in the Methatheria clade and to confirm that other opossum species is eligible as a good model for pudendal nerve studies

Acceptance of the bodypainting as supportive method to learn the surface locomotor apparatus anatomy of the horse

Although bodypainting has been reported as a great resource for teaching surface anatomy of humans, its use in veterinary anatomy has not been scientifically reported. In the present study, bodypainting was performed on 4 horses for anatomy teaching purposes of the equine locomotor apparatus. We aimed to use the bodypainting method as an additional tool to classic teaching and to test the relevance of our purpose. Twenty one Brazilian veterinary students were given a 90-min session, which included a presentation of painted horses, with opportunities for the students to ask questions and to palpate anatomic locations on the horses. Based on a questionnaire, there was unanimous student satisfaction with this technique. Furthermore, student scores on practical tests to evaluate the attention retain given immediately before and 1 h after the session were 33.9 ± 19.8% and 69.0 ± 18.4%, respectively (p < 0.001). We concluded that bodypainting has great potential for support the classic lectures of the equine locomotor apparatus

Gross morphometry of the heart of the Common marmoset

  The Callithrix jacchus is a Brazilian endemic species that has been widely used asan experimental model in biomedical research. Anatomical data are necessary to support experimental studies with this species. Eleven hearts of C. jacchus from the German Primate Centre (DPZ) have been studied in order to characterize their gross morphometry and compare them with other animal models and human. Biometric data were also obtained. The mean values for morphometry of the hearts did not show any significant difference between male and female. The relative heart weight was similar to human, bovine and equine species. Considering those aspects, the C. jacchus could be used as non-human primate experimental modelfor biomedical studies on heart.

Hall Effect of Spin Waves in Frustrated Magnets

We examine a possible spin Hall effect for localized spin systems with no charge degrees of freedom. In this scenario, a longitudinal magnetic field gradient induces a transverse spin current carried by spin wave excitations with an anomalous velocity which is associated with the Berry curvature raised by spin chirality, in analogy with anomalous Hall effects in itinerant electron systems. Our argument is based on a semiclassical equations of motion applicable to general spin systems. Also, a microscopic model of frustrated magnets which exhibits the anamalous spin Hall effect is presented.Comment: 5 pages, title and presentation style are changed, accepted for publication in Phys. Rev. Let

The H3K27M mutation alters stem cell growth, epigenetic regulation, and differentiation potential

BACKGROUND: Neurodevelopmental disorders increase brain tumor risk, suggesting that normal brain development may have protective properties. Mutations in epigenetic regulators are common in pediatric brain tumors, highlighting a potentially central role for disrupted epigenetic regulation of normal brain development in tumorigenesis. For example, lysine 27 to methionine mutation (H3K27M) in the H3F3A gene occurs frequently in Diffuse Intrinsic Pontine Gliomas (DIPGs), the most aggressive pediatric glioma. As H3K27M mutation is necessary but insufficient to cause DIPGs, it is accompanied by additional mutations in tumors. However, how H3K27M alone increases vulnerability to DIPG tumorigenesis remains unclear. RESULTS: Here, we used human embryonic stem cell models with this mutation, in the absence of other DIPG contributory mutations, to investigate how H3K27M alters cellular proliferation and differentiation. We found that H3K27M increased stem cell proliferation and stem cell properties. It interfered with differentiation, promoting anomalous mesodermal and ectodermal gene expression during both multi-lineage and germ layer-specific cell specification, and blocking normal differentiation into neuroectoderm. H3K27M mutant clones exhibited transcriptomic diversity relative to the more homogeneous wildtype population, suggesting reduced fidelity of gene regulation, with aberrant expression of genes involved in stem cell regulation, differentiation, and tumorigenesis. These phenomena were associated with global loss of H3K27me3 and concordant loss of DNA methylation at specific genes in H3K27M-expressing cells. CONCLUSIONS: Together, these data suggest that H3K27M mutation disrupts normal differentiation, maintaining a partially differentiated state with elevated clonogenicity during early development. This disrupted response to early developmental cues could promote tissue properties that enable acquisition of additional mutations that cooperate with H3K27M mutation in genesis of DMG/DIPG. Therefore, this work demonstrates for the first time that H3K27M mutation confers vulnerability to gliomagenesis through persistent clonogenicity and aberrant differentiation and defines associated alterations of histone and DNA methylation

Impact of Mechanical Unloading on Microvasculature and Associated Central Remodeling Features of the Failing Human Heart

ObjectivesThis study investigates alterations in myocardial microvasculature, fibrosis, and hypertrophy before and after mechanical unloading of the failing human heart.BackgroundRecent studies demonstrated the pathophysiologic importance and significant mechanistic links among microvasculature, fibrosis, and hypertrophy during the cardiac remodeling process. The effect of left ventricular assist device (LVAD) unloading on cardiac endothelium and microvasculature is unknown, and its influence on fibrosis and hypertrophy regression to the point of atrophy is controversial.MethodsHemodynamic data and left ventricular tissue were collected from patients with chronic heart failure at LVAD implant and explant (n = 15) and from normal donors (n = 8). New advances in digital microscopy provided a unique opportunity for comprehensive whole-field, endocardium-to-epicardium evaluation for microvascular density, fibrosis, cardiomyocyte size, and glycogen content. Ultrastructural assessment was done with electron microscopy.ResultsHemodynamic data revealed significant pressure unloading with LVAD. This was accompanied by a 33% increase in microvascular density (p = 0.001) and a 36% decrease in microvascular lumen area (p = 0.028). We also identified, in agreement with these findings, ultrastructural and immunohistochemical evidence of endothelial cell activation. In addition, LVAD unloading significantly increased interstitial and total collagen content without any associated structural, ultrastructural, or metabolic cardiomyocyte changes suggestive of hypertrophy regression to the point of atrophy and degeneration.ConclusionsThe LVAD unloading resulted in increased microvascular density accompanied by increased fibrosis and no evidence of cardiomyocyte atrophy. These new insights into the effects of LVAD unloading on microvasculature and associated key remodeling features might guide future studies of unloading-induced reverse remodeling of the failing human heart

A Domain-Specific Language for Incremental and Modular Design of Large-Scale Verifiably-Safe Flow Networks (Preliminary Report)

We define a domain-specific language (DSL) to inductively assemble flow networks from small networks or modules to produce arbitrarily large ones, with interchangeable functionally-equivalent parts. Our small networks or modules are "small" only as the building blocks in this inductive definition (there is no limit on their size). Associated with our DSL is a type theory, a system of formal annotations to express desirable properties of flow networks together with rules that enforce them as invariants across their interfaces, i.e, the rules guarantee the properties are preserved as we build larger networks from smaller ones. A prerequisite for a type theory is a formal semantics, i.e, a rigorous definition of the entities that qualify as feasible flows through the networks, possibly restricted to satisfy additional efficiency or safety requirements. This can be carried out in one of two ways, as a denotational semantics or as an operational (or reduction) semantics; we choose the first in preference to the second, partly to avoid exponential-growth rewriting in the operational approach. We set up a typing system and prove its soundness for our DSL.Comment: In Proceedings DSL 2011, arXiv:1109.032

Mapping interactions with the chaperone network reveals factors that protect against tau aggregation.

A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease

Conference highlights of the 15th international conference on human retrovirology: HTLV and related retroviruses, 4-8 june 2011, Leuven, Gembloux, Belgium

The June 2011 15th International Conference on Human Retrovirology: HTLV and Related Viruses marks approximately 30 years since the discovery of HTLV-1. As anticipated, a large number of abstracts were submitted and presented by scientists, new and old to the field of retrovirology, from all five continents. The aim of this review is to distribute the scientific highlights of the presentations as analysed and represented by experts in specific fields of epidemiology, clinical research, immunology, animal models, molecular and cellular biology, and virology