Localization of dynamin 2 in rat seminiferous tubules during the spermatogenic cycle.

Dynamin is a protein essential to endocytosis. Dynamin 2, a dynamin isoform, is expressed most intensely in testicular tissue; however, precise localization has never been studied. Therefore, we investigated the expression of dynamin 2 in rat testicular tissue using immunohistochemical methods, and discuss here the physiological function of this protein. Testicular tissues were obtained from Wistar rats at 10, 21 and 63 days of age. Immunohistochemistrical examination and Western blot analysis were conducted using dynamin 2 specific antibody. Western blot analysis showed that expression in 21- and 63-day-old rats was more intense than that in 10-day-old rats. Dynamin 2 expression was observed using immunohistochemical method in the seminiferous tubules of all rats. In the 63-day-old rats, the expression was intense, especially in spermatids in the earlier maturation stages and in spermatocytes, and was observed in Sertoli cells. However, in spermatids, the expression gradually declined as spermatids matured to spermatozoa. In the 21-day-old rats, the expression was evident in spermatocytes and Sertoli cells, but that in the 10-day-old rats was weak. Intense expression of dynamin 2 during spermatogenesis suggests that this protein plays an important role in this process.</p

Naked Singularity and Thunderbolt

We consider quantum theoretical effects of the sudden change of the boundary conditions which mimics the occurrence of naked singularities. For a simple demonstration, we study a massless scalar field in $(1 + 1)$-dimensional Minkowski spacetime with finite spatial interval. We calculate the vacuum expectation value of the energy-momentum tensor and explicitly show that singular wave or {\em thunderbolt} appears along the Cauchy horizon. The thunderbolt possibly destroys the Cauchy horizon if its backreaction on the geometry is taken into account, leading to quantum restoration of the global hyperbolicity. The result of the present work may also apply to the situation that a closed string freely oscillating is traveling to a brane and changes itself to an open string pinned-down by the ends satisfying the Dirichlet boundary conditions on the brane.Comment: 12 pages, 1 figure, references added, to appear in Phys. Rev.

Importância dos Saca-Rabos (Herpestes Ichneumon) como Reservatório de Mycobacterium avium subsp. paratuberculosis. Deteção por Técnicas Tradicionais e Moleculares

Poster apresentado nas IV Jornadas de Genética, realizadas na UTAD, Vila Real, nos dias 1,2 e 3 de Março de 2012.Os saca-rabos (Herpestes ichneumon) também conhecidos por mangustos, são carnívoros diurnos selvagens que juntamente com a geneta (Genetta genetta) representam os exemplares da família Viverridae em Portugal. É uma espécie cinegética de caça menor que se alimenta de coelhos, roedores, aves, cobras, insectos e ovos. Neste estudo colheram-se amostras de 8 animais mortos por atropelamento e em ações de controlo de predadores, durante os anos de 2010 e 2011, nos concelhos de Idanha-a-Nova e Penamacor do distrito de Castelo Branco. As amostras colhidas foram fígado, pulmão, baço, intestino, rim, gânglio mesentérico, retrofaríngeo, mediastínico, amígdalas e fezes. As amostras foram submetidas à técnica de PCR e a cultura microbiológica em meios específicos. Em três saca-rabos (37,5%) detectou-se Mycobacterium avium subsp. paratuberculosis (Map) através da técnica de biologia molecular. Dois eram machos e um era fêmea. Map foi confirmado também em cultura nos dois machos. Sete saca-rabos (87,5%) apresentaram bactérias álcool-ácido resistentes compatíveis com Map em esfregaços de diferentes tecidos, quando corados pelo método de Ziehl-Neelsen. Estes resultados preliminares confirmam os saca-rabos como reservatório de Map no nosso país. Atualmente, estão a ser desenvolvidos mais estudos para a avaliação dos saca-rabos na dinâmica da infeção de Map em mamíferos selvagens

Expression and Role of IL-1β Signaling in Chondrocytes Associated with Retinoid Signaling during Fracture Healing

The process of fracture healing consists of an inflammatory reaction and cartilage and bone tissue reconstruction. The inflammatory cytokine interleukin-1β (IL-1β) signal is an important major factor in fracture healing, whereas its relevance to retinoid receptor (an RAR inverse agonist, which promotes endochondral bone formation) remains unclear. Herein, we investigated the expressions of IL-1β and retinoic acid receptor gamma (RARγ) in a rat fracture model and the effects of IL-1β in the presence of one of several RAR inverse agonists on chondrocytes. An immunohistochemical analysis revealed that IL-1β and RARγ were expressed in chondrocytes at the fracture site in the rat ribs on day 7 post-fracture. In chondrogenic ATDC5 cells, IL-1β decreases the levels of aggrecan and type II collagen but significantly increased the metalloproteinase-13 (Mmp13) mRNA by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. An RAR inverse agonist (AGN194310) inhibited IL-1β-stimulated Mmp13 and Ccn2 mRNA in a dose-dependent manner. Phosphorylated extracellular signal regulated-kinases (pERK1/2) and p-p38 mitogen-activated protein kinase (MAPK) were increased time-dependently by IL-1β treatment, and the IL-1β-induced p-p38 MAPK was inhibited by AGN194310. Experimental p38 inhibition led to a drop in the IL-1β-stimulated expressions of Mmp13 and Ccn2 mRNA. MMP13, CCN2, and p-p38 MAPK were expressed in hypertrophic chondrocytes near the invaded vascular endothelial cells. As a whole, these results point to role of the IL-1β via p38 MAPK as important signaling in the regulation of the endochondral bone formation in fracture healing, and to the actions of RAR inverse agonists as potentially relevant modulators of this process

Who's Afraid of Naked Singularities?

To probe naked spacetime singularities with waves rather than with particles we study the well-posedness of initial value problems for test scalar fields with finite energy so that the natural function space of initial data is the Sobolev space. In the case of static and conformally static spacetimes we examine the essential self-adjointness of the time translation operator in the wave equation defined in the Hilbert space. For some spacetimes the classical singularity becomes regular if probed with waves while stronger classical singularities remain singular. If the spacetime is regular when probed with waves we may say that the spacetime is `globally hyperbolic.'Comment: 25 pages, 3 figures, Accepted for publication in Phys.Rev.

Pneumonia Caused by Severe Acute Respiratory Syndrome Coronavirus 2 and Influenza Virus: A Multicenter Comparative Study

Background: Detailed differences in clinical information between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia (CP), which is the main phenotype of SARS-CoV-2 disease, and influenza pneumonia (IP) are still unclear. Methods: A prospective, multicenter cohort study was conducted by including patients with CP who were hospitalized between January and June 2020 and a retrospective cohort of patients with IP hospitalized from 2009 to 2020. We compared the clinical presentations and studied the prognostic factors of CP and IP. Results: Compared with the IP group (n = 66), in the multivariate analysis, the CP group (n = 362) had a lower percentage of patients with underlying asthma or chronic obstructive pulmonary disease (P < .01), lower neutrophil-to-lymphocyte ratio (P < .01), lower systolic blood pressure (P < .01), higher diastolic blood pressure (P < .01), lower aspartate aminotransferase level (P < .05), higher serum sodium level (P < .05), and more frequent multilobar infiltrates (P < .05). The diagnostic scoring system based on these findings showed excellent differentiation between CP and IP (area under the receiver operating characteristic curve, 0.889). Moreover, the prognostic predictors were different between CP and IP. Conclusions: Comprehensive differences between CP and IP were revealed, highlighting the need for early differentiation between these 2 pneumonias in clinical settings

Identification of cell cycle–arrested quiescent osteoclast precursors in vivo

Osteoclasts are multinucleated cells that resorb bone. Although osteoclasts originate from the monocyte/macrophage lineage, osteoclast precursors are not well characterized in vivo. The relationship between proliferation and differentiation of osteoclast precursors is examined in this study using murine macrophage cultures treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB (RANK) ligand (RANKL). Cell cycle–arrested quiescent osteoclast precursors (QuOPs) were identified as the committed osteoclast precursors in vitro. In vivo experiments show that QuOPs survive for several weeks and differentiate into osteoclasts in response to M-CSF and RANKL. Administration of 5-fluorouracil to mice induces myelosuppression, but QuOPs survive and differentiate into osteoclasts in response to an active vitamin D3 analogue given to those mice. Mononuclear cells expressing c-Fms and RANK but not Ki67 are detected along bone surfaces in the vicinity of osteoblasts in RANKL-deficient mice. These results suggest that QuOPs preexist at the site of osteoclastogenesis and that osteoblasts are important for maintenance of QuOPs

Sulfoxide Synthesis from Sulfinate Esters under Pummerer-like Conditions

A facile synthetic method of allyl sulfoxides by S-allylation of sulfinate esters through sulfonium intermediates has been developed without [3,3]-sigmatropic rearrangement and further Pummerer-type reactions of the resulting allyl sulfoxides. On the basis of the plausible reaction mechanism involving sulfonium salt intermediates, S-alkynylation and S-arylation were also accomplished.<br /