Curcumin and Ethanol Effects in Trembler-J Schwann Cell Culture.

Charcot-Marie-Tooth (CMT) syndrome is the most common progressive human motor and sensory peripheral neuropathy. CMT type 1E is a demyelinating neuropathy affecting Schwann cells due to peripheral-myelin-protein-22 (PMP22) mutations, modelized by Trembler-J mice. Curcumin, a natural polyphenol compound obtained from turmeric (Curcuma longa), exhibits dose- and time-varying antitumor, antioxidant and neuroprotective properties, however, the neurotherapeutic actions of curcumin remain elusive. Here, we propose curcumin as a possible natural treatment capable of enhancing cellular detoxification mechanisms, resulting in an improvement of the neurodegenerative Trembler-J phenotype. Using a refined method for obtaining enriched Schwann cell cultures, we evaluated the neurotherapeutic action of low dose curcumin treatment on the PMP22 expression, and on the chaperones and autophagy/mammalian target of rapamycin (mTOR) pathways in Trembler-J and wild-type genotypes. In wild-type Schwann cells, the action of curcumin resulted in strong stimulation of the chaperone and macroautophagy pathway, whereas the modulation of ribophagy showed a mild effect. However, despite the promising neuroprotective effects for the treatment of neurological diseases, we demonstrate that the action of curcumin in Trembler-J Schwann cells could be impaired due to the irreversible impact of ethanol used as a common curcumin vehicle necessary for administration. These results contribute to expanding our still limited understanding of PMP22 biology in neurobiology and expose the intrinsic lability of the neurodegenerative Trembler-J genotype. Furthermore, they unravel interesting physiological mechanisms of cellular resilience relevant to the pharmacological treatment of the neurodegenerative Tremble J phenotype with curcumin and ethanol. We conclude that the analysis of the effects of the vehicle itself is an essential and inescapable step to comprehensibly assess the effects and full potential of curcumin treatment for therapeutic purposes.

Revealing stage-specific expression patterns of long noncoding RNAs along mouse spermatogenesis.

The discovery of a large number of long noncoding RNAs (lncRNAs), and the finding that they may play key roles in different biological processes, have started to provide a new perspective in the understanding of gene regulation. It has been shown that the testes express the highest amount of lncRNAs among different vertebrate tissues. However, although some studies have addressed the characterization of lncRNAs along spermatogenesis, an exhaustive analysis of the differential expression of lncRNAs at its different stages is still lacking. Here, we present the results for lncRNA transcriptome profiling along mouse spermatogenesis, employing highly pure flow sorted spermatogenic stage-specific cell populations, strand-specific RNAseq, and a combination of up-to-date bioinformatic pipelines for analysis. We found that the vast majority of testicular lncRNA genes are expressed at post-meiotic stages (i.e. spermiogenesis), which are characterized by extensive post-transcriptional regulation. LncRNAs at different spermatogenic stages shared common traits in terms of transcript length, exon number, and biotypes. Most lncRNAs were lincRNAs, followed by a high representation of antisense (AS) lncRNAs. Co-expression analyses showed a high correlation along the different spermatogenic stage transitions between the expression patterns of AS lncRNAs and their overlapping protein-coding genes, raising possible clues about lncRNA-related regulatory mechanisms. Interestingly, we observed the co-localization of an AS lncRNA and its host sense mRNA in the chromatoid body, a round spermatids-specific organelle that has been proposed as a reservoir of RNA-related regulatory machinery. An additional, intriguing observation is the almost complete lack of detectable expression for Y-linked testicular lncRNAs, despite that a high number of lncRNA genes are annotated for this chromosome.

F-actin distribution at nodes of Ranvier and Schmidt-Lanterman incisures in mammalian sciatic nerves.

Very little is known about the function of the F-actin cytoskeleton in the regeneration and pathology of peripheral nerve fibers. The actin cytoskeleton has been associated with maintenance of tissue structure, transmission of traction and contraction forces, and an involvement in cell motility. Therefore, the state of the actin cytoskeleton strongly influences the mechanical properties of cells and intracellular transport therein. In this work, we analyze the distribution of F-actin at Schmidt-Lanterman Incisures (SLI) and nodes of Ranvier (NR) domains in normal, regenerating and pathologic Trembler J (TrJ/+) sciatic nerve fibers, of rats and mice. F-actin was quantified and it was found increased in TrJ/+, both in SLI and NR. However, SLI and NR of regenerating rat sciatic nerve did not show significant differences in F-actin, as compared with normal nerves. Cytochalasin-D and Latrunculin-A were used to disrupt the F-actin network in normal and regenerating rat sciatic nerve fibers. Both drugs disrupt F-actin, but in different ways. Cytochalasin-D did not disrupt Schwann cell (SC) F-actin at the NR. Latrunculin-A did not disrupt F-actin at the boundary region between SC and axon at the NR domain. We surmise that the rearrangement of F-actin in neurological disorders, as presented here, is an important feature of TrJ/+ pathology as a Charcot-Marie-Tooth (CMT) model.

Deslizamento de retalho palatino: visão estética / The palatal sliding flap: an aesthetic view

A relação implante/estética está se tornando cada vez mais desafiadora, pois para uma prótese adequada, devemos conhecer e imitar forma e contorno do dente adjacente, papila interdental, zênite gengival, dentre outros. Pensando nesta combinação, os autores propuseram, neste trabalho, uma técnica modificada visando oferecer um prognóstico estético favorável. As técnicas utilizadas foram a de preenchimento alveolar com osso liofilizado bovino pós-exodontia e deslizamento de retalho palatino modificado no fechamento da ferida alveolar. O objetivo desta associação de técnicas é a manutenção do rebordo para diminuição da perda de crista óssea e/ou parede vestibular, manutenção do arcabouço alveolar quando existem defeitos estabelecidos, fechamento por primeira intenção da ferida cirúrgica e ganho de tecido gengival para a reorganização de papila interdental e zênite gengival evitando, assim, a necessidade de um segundo momento cirúrgico na manipulação de tecido mole para ganho estético. Os resultados são provenientes da prática clínica, porém, de extrema satisfação.

The relationship between aesthetics and implants is becoming more and more important. It is imperative that we know about the restored tooth’s planned shape and contour to have an appropriate prosthesis with adequate interdental papillae and gingival margins. In this paper, the authors propose a modified extraction closure procedure attempting to offer a favorable aesthetic prognosis for the final implant. We used two different alveolar preservation techniques with freeze-dried bone after tooth extraction and a modified palatal rotation flap for soft tissue coverage. The aim was to keep buccal and alveolar crest bone loss to a minimum and to have closure and healing by primary intention. The procedure was designed to enhance soft tissue reorganization of the interdental papillae and marginal gingival tissue. Using these combined techniques, there is no need to gain soft tissue in a second surgical procedure. The results are variable, but extreme satisfactory.

El marxismo en América Latina

Esta antología reúne textos marxistas latinoamericanos de carácter diverso, análisis sociales, propuestas políticas, de épocas también diversas, pero con algo en común: todos ellos se refieren a América Latina y tienden a ejemplificar los diversos niveles en que ha sido instrumentada la teoría marxista en el continente

El marxismo en América Latina

Esta antología reúne textos marxistas latinoamericanos de carácter diverso, análisis sociales, propuestas políticas, de épocas también diversas, pero con algo en común: todos ellos se refieren a América Latina y tienden a ejemplificar los diversos niveles en que ha sido instrumentada la teoría marxista en el continente