The bidirectional role of GABAA and GABAB receptors during the differentiation process of neural precursor cells of the subventricular zone.

The intricate process of neuronal differentiation integrates multiple signals to induce transcriptional, morphological, and electrophysiological changes that reshape the properties of neural precursor cells during their maturation and migration process. An increasing number of neurotransmitters and biomolecules have been identified as molecular signals that trigger and guide this process. In this sense, taurine, a sulfur-containing, non-essential amino acid widely expressed in the mammal brain, modulates the neuronal differentiation process. In this study, we describe the effect of taurine acting via the ionotropic GABAA receptor and the metabotropic GABAB receptor on the neuronal differentiation and electrophysiological properties of precursor cells derived from the subventricular zone of the mouse brain. Taurine stimulates the number of neurites and favors the dendritic complexity of the neural precursor cells, accompanied by changes in the somatic input resistance and the strength of inward and outward membranal currents. At the pharmacological level, the blockade of GABAA receptors inhibits these effects, whereas the stimulation of GABAB receptors has no positive effects on the taurine-mediated differentiation process. Strikingly, the blockade of the GABAB receptor with CGP533737 stimulates neurite outgrowth, dendritic complexity, and membranal current kinetics of neural precursor cells. The effects of taurine on the differentiation process involve Ca2+ mobilization and the activation of intracellular signaling cascades since chelation of intracellular calcium with BAPTA-AM, and inhibition of the CaMKII, ERK1/2, and Src kinase inhibits the neurite outgrowth of neural precursor cells of the subventricular zone.

Taurine Promotes Differentiation and Maturation of Neural Stem/Progenitor Cells from the Subventricular Zone via Activation of GABAA Receptors.

Neurogenesis, the formation of new neurons in the brain, occurs throughout the lifespan in the subgranular zone of the dentate gyrus and subventricular zone (SVZ) lining the lateral ventricles of the mammal brain. In this process, gamma-aminobutyric acid (GABA) and its ionotropic receptor, the GABAA receptor (GABAAR), play a critical role in the proliferation, differentiation, and migration process of neural stem/progenitor cells (NPC). Taurine, a non-essential amino acid widely distributed throughout the central nervous system, increases the proliferation of SVZ progenitor cells by a mechanism that may involve GABAAR activation. Therefore, we characterized the effects of taurine on the differentiation process of NPC expressing GABAAR. Preincubation of NPC-SVZ with taurine increased microtubule-stabilizing proteins assessed with the doublecortin assay. Taurine, like GABA, stimulated a neuronal-like morphology of NPC-SVZ and increased the number and length of primary, secondary, and tertiary neurites compared with control NPC of the SVZ. Furthermore, neurite outgrowth was prevented when simultaneously incubating cells with taurine or GABA and the GABAAR blocker, picrotoxin. Patch-clamp recordings revealed a series of modifications in the NPCs' passive and active electrophysiological properties exposed to taurine, including regenerative spikes with kinetic properties similar to the action potentials of functional neurons.

The influence of psychosocial factors on patient-reported outcome measures in rotator cuff tears pre- and post-surgery: a systematic review.

PURPOSE: Recent research shows that major levels of psychological distress correlate with higher pain and reduced function in patients with shoulder and rotator cuff pathology. A systematic review updating a review published in 2016 was conducted to determine the degree of consistency and the strength of association between psychosocial factors and patient-reported outcomes (PROMs) in patients with rotator cuff repair (RCR) with new high-quality literature. METHODS: The bibliographic searches were conducted from May to June 2020 within the following databases: MEDLINE/PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, and Web of Science. The articles included should discuss the association between psychosocial factors and outcomes in patients with documented or diagnosed rotator cuff tears through clinical and/or radiological examination. The Methodological Index for Non-Randomized Studies (MINORS) tool was used to assess the methodological quality. RESULTS: Fifteen articles were included. Negative psychosocial factors were found consistently associated with worse function and disability in the pre- and post-operative period. In particular, psychosocial factors regarding emotional or mental health were associated with a weak to a substantial degree with preoperative and postoperative function/disability and pain intensity in patients undergoing RCR. CONCLUSION: In patients undergoing repair of the rotator cuff tear, there was a correlation between poor psychological function before surgery and worsening post-surgical outcomes, such as persistence of postoperative pain intensity and worse levels of function/disability.

Conocimientos sobre salud ocupacional en tenientes del ejército del Perú / Occupational health knowledge in lieutenants of the Peruvian army

Introducción: La salud ocupacional es una actividad multidisciplinaria que promueve y protege la salud de los trabajadores. El conocimiento de las condiciones de riesgo previene los accidentes y enfermedades ocupacionales. Objetivo: Determinar el nivel de conocimientos en salud ocupacional en tenientes del Ejército del Perú. Métodos: Estudio observacional y transversal. Participaron 86 tenientes de una promoción de la Escuela de Infantería. Se realizó el Cuestionario de conocimientos en salud ocupacional. Se aplicó estadística descriptiva para las características generales y para la asociación con los conocimientos, la prueba ji cuadrado. Resultados: La edad promedio fue 28,4 años (DE=1,26; Mín.26, Máx.32), 51,16 por ciento presentaron nivel bajo de conocimientos; trabajadores que no recordaban haber recibido capacitaciones en salud ocupacional y que sufrieron accidente de trabajo tuvieron nivel bajo de conocimientos, 80 por ciento (p = 0,049) y 73,68 por ciento (p = 0,026) respectivamente. La pregunta con mayores aciertos fue sobre el examen de salud ocupacional anual con un 75,58 por ciento, y la de menor conocimiento, sobre la cobertura del seguro complementario de riesgos con un 25,58 por ciento. Conclusiones: El nivel de conocimiento predominante sobre salud ocupacional en tenientes del ejército del Perú, fue bajo, con mayores porcentajes en los que no recuerdan capacitación en salud ocupacional y los que tuvieron algún accidente laboral(AU)

Introduction: Occupational health is a multidisciplinary activity that promotes and protects the health of workers. Knowledge of risk conditions prevents occupational accidents and diseases. Objective: To determine the level of occupational health knowledge in lieutenants of the Peruvian Army. Methods: Observational and cross-sectional study. 86 lieutenants of a promotion of the Infantry School participated. The Occupational Health Knowledge Questionnaire was applied. Descriptive statistics were applied for the general characteristics and the Chi-square test for the association with knowledge. Results: Mean age 28,4 years (SD = 1,26; Min. 26, Max. 32), 51,16 percent presented a poor level of knowledge; workers who did not remember having received training in Occupational Health and who suffered a work accident, 80 percent (p = 0,049) and 73,68 percent (p = 0,026) they had a bad level respectively. The question with the highest correct answers was about the annual occupational health examination with 75,58 percent, and the one with the least knowledge about the complementary risk insurance coverage with 25,58 percent. Conclusions: The predominant level of knowledge about occupational health in lieutenants in the Peruvian army was poor, with higher percentages in those who did not remember training in occupational health and those who had an occupational accident(AU)

Differential replicative fitness of the four dengue virus serotypes circulating in Colombia in human liver Huh7 cells

ABSTRACT Dengue has been a significant public health problem in Colombia since the simultaneous circulation of the four dengue virus serotypes. The replicative fitness of dengue is a biological feature important for virus evolution and contributes to elucidating the behavior of virus populations and viral pathogenesis. However, it has not yet been studied in Colombian isolates. This study aimed to compare the replicative fitness of the four dengue virus serotypes and understand the association between the serotypes, their in vitro infection ability, and their replication in target cells. We used three isolates of each DENV serotype to infect Huh-7 cells at an MOI of 0.5. The percentage of infected cells was evaluated by flow cytometry, cell viability was evaluated by MTT assay, and the pathogenicity index was calculated as a ratio of both parameters. The replicative fitness was measured by the number of viral genome copies produced using quantitative PCR and the production of infectious viral progeny was measured by plaque assay. We showed that Huh-7 cells were susceptible to infection with all the different strain isolates. Nevertheless, the biological characteristics, such as infectious ability and cell viability, were strain-dependent. We also found different degrees of pathogenicity between strains of the four serotypes, representative of the heterogeneity displayed in the circulating population. When we analyzed the replicative fitness using the mean values obtained from RT-qPCR and plaque assay for the different strains, we found serotype-dependent behavior. The highest mean values of replicative fitness were obtained for DENV-1 (log 4.9 PFU/ml) and DENV-4 (log 5.28 PFU/ml), followed by DENV-2 (log 3.9 PFU/ml) and DENV-3 (log 4.31 PFU/ml). The internal heterogeneity of the replicative fitness within each serotype could explain the simultaneous circulation of the four DENV serotypes in Colombia.

Differential replicative fitness of the four dengue virus serotypes circulating in Colombia in human liver Huh7 cells.

Dengue has been a significant public health problem in Colombia since the simultaneous circulation of the four dengue virus serotypes. The replicative fitness of dengue is a biological feature important for virus evolution and contributes to elucidating the behavior of virus populations and viral pathogenesis. However, it has not yet been studied in Colombian isolates. This study aimed to compare the replicative fitness of the four dengue virus serotypes and understand the association between the serotypes, their in vitro infection ability, and their replication in target cells. We used three isolates of each DENV serotype to infect Huh-7 cells at an MOI of 0.5. The percentage of infected cells was evaluated by flow cytometry, cell viability was evaluated by MTT assay, and the pathogenicity index was calculated as a ratio of both parameters. The replicative fitness was measured by the number of viral genome copies produced using quantitative PCR and the production of infectious viral progeny was measured by plaque assay. We showed that Huh-7 cells were susceptible to infection with all the different strain isolates. Nevertheless, the biological characteristics, such as infectious ability and cell viability, were strain-dependent. We also found different degrees of pathogenicity between strains of the four serotypes, representative of the heterogeneity displayed in the circulating population. When we analyzed the replicative fitness using the mean values obtained from RT-qPCR and plaque assay for the different strains, we found serotype-dependent behavior. The highest mean values of replicative fitness were obtained for DENV-1 (log 4.9 PFU/ml) and DENV-4 (log 5.28 PFU/ml), followed by DENV-2 (log 3.9 PFU/ml) and DENV-3 (log 4.31 PFU/ml). The internal heterogeneity of the replicative fitness within each serotype could explain the simultaneous circulation of the four DENV serotypes in Colombia.

Multidimensional study of orofacial chronic neuropathic pain: an experimental study in rats

Orofacial neuropathic chronic pain (NCP) is frequently attributed to lesions caused by orofacial surgeries and dental treatments. there are many experimental models available to study orofacial NCP, however, many are extremely painful for the animal due to the amplitude of the innervated region. a previously proposed mental nerve constriction model, mNC, was used in this project. forty wistar rats were randomly divided into two groups: one group included rats with mNC (n=20), and another rats with sham lesions (n=20). through the use of the fixed ratio program and the progressive program, a decrease of motivation for a sweet substance, caused by the lesion, was evaluated. the possibility of alterations in cognitive learning and adaptation abilities was also assessed using the go/no-go behavioral task. the mNC group showed low induced and spontaneously evoked pain responses, as well as a decrease in the motivation for sucrose, a sign of anhedonia. this decrease does not depend on taste processing. finally, although no alterations in the learning-memory process were observed, the mNC group did show alterations when adapting to a new rule.

The rabies virus phosphoprotein synthesis and subcellular localization are modified by nerve growth factor.

Rabies virus P protein participates as a regulating factor in viral transcription and replication; recent studies found an antitranscriptional and antireplicative effect of nerve growth factor (NGF) and Neurotrophin-3 (NT-3) in infected neuron cultures. We investigated here the specific effect of the neurotrophins on P protein, evaluating its synthesis and subcellular distribution in adult mouse dorsal root ganglia neuron cultures infected and treated with NGF or NT-3. The results showed that NGF, but not NT-3, caused an increase in the quantity of P protein and an accumulation of protein in neuronal bodies, revealing changes in transport to the neuritic processes.

LÍNEA CELULAR DE Aedes aegypti (DIPTERA: CULICIDAE) AEGY28 REFRACTARIA A LA INFECCIÓN CON LOS VIRUS DENGUE 2 Y FIEBRE AMARILLA / AEGY28 Cell Line of Aedes aegypti (Diptera Culicidae) is Infection Refractory to Dengue 2 and Yellow Fever Virus

Los cultivos celulares de mosquitos son frecuentemente utilizados para el aislamiento, identificación y caracterización de arbovirus. Para el estudio de los virus dengue (VDEN) y virus de fiebre amarilla (VFA) se emplean, principalmente, la línea celular C6/36 de Aedes albopictus y la línea celular AP61, obtenida de Aedes pseudoscutellaris. La línea celular de A. aegypti AEGY28, previamente obtenida a partir de tejidos embrionarios del vector, se utilizó en el presente trabajo para evaluar la susceptibilidad a la infección por VDEN y VFA. Para ello, los cultivos celulares se ensayaron a diferente multiplicidad de infección con los aislados clínicos de virus dengue tipo 2 (COL789, MOI: 1 y 5) y VFA (V341, MOI 0,02). Posteriormente se realizó la detección de antígenos virales por la técnica de inmunocitoquímica y su cuantificación por la técnica de CellELISA fluorométrica. Se usaron como controles positivos de infección, tanto células C6/36 como células VERO. Inesperadamente, no se observó inmunoreactividad en las células de A. aegypti infectadas con ambos tipos de virus en ninguno de los MOI o tiempos estudiados. Tampoco se evidenció antígeno por la técnica fluorométrica ni fue posible detectar RNA viral por RTPCR a partir de células infectadas. Por lo tanto, se puede concluir que la línea celular de A. aegypti no es susceptible a la infección por VDEN ni por VFA. Ello podría estar relacionado con características propias de la membrana celular o de la maquinaria enzimática necesaria para la replicación viral.

Mosquito cell derived cultures are useful tools for arbovirus isolation, identification or characterization. For studying dengue (DENV) and yellow fever viruses (YFV) Aedes albopictus C6/36 or Aedes pseudoscutellaris AP61 cell lines, are normally used. The Aedes aegypti AEGY28 cell line was obtained from embryonic tissues and characterized previously by one of us. In order to evaluate its susceptibility to two Flavivirus, AEGY28 cells were inoculated with different multiplicity of infection (MOI) with type 2 DENV (COL789, MOI: 1 and 5) and YFV clinical isolates (V341, MOI 0,02) then processed at different times post infection (p.i.). Immunostaining and fluorometric cellELISA were carried out to identify and quantify viral antigens. C6/36 and Vero cells were used as positive controls. Unexpectedly, immunoreactivity was not found in inoculated AEGY28 cells, even in higher MOI or late times p.i., therefore antigen quantification using fluorometric cellELISA were not plausible. Reverse transcriptase PCR with specific primers did not detect viral RNA in AEGY28 inoculated cells. We can conclude that Aedes aegypti AEGY28 cell line is not susceptible to dengue and yellow fever Flavivirus, a finding possibly related with the lacking of specific molecules at the plasma membrane or absence of cell machinery necessary for viral replication.

[Production and characterization of a polyclonal antibody against rabies virus phosphoprotein]. / Producción y caracterización de un anticuerpo policlonal dirigido contra la fosfoproteína del virus de la rabia.

INTRODUCTION: The expression of recombinant viral proteins has been a useful tool to study molecular biology and pathogenesis of virus infections. Because commercial specific antibodies to rabies virus phosphoprotein (P) are currently unavailable, these antibodies must be generated de novo in order to study the role of P protein during the infectious process. OBJECTIVE: A polyclonal antibody was produced and characterized for use against the phosphoprotein (P) of rabies virus. The antibody was raised in rabbits with a recombinant viral phosphoprotein (P) produced in Escherichia coli. MATERIALS AND METHODS: Gene P coding for the viral phosphoprotein (P) was amplified by RT-PCR and cloned into the expression vector PinPoint Xa-1 T. The recombinant protein P was expressed in Escherichia coli, purified by affinity chromatography and used to produce a polyclonal antibody anti-P. The antibody anti-P was purified and characterized by immunocytochemistry, immunofluorescence, fluorometric CELL-ELISA and Western blotting. RESULTS: The recombinant viral phosphoprotein was successfully expressed as a 50 kd biotinylated fusion protein which corresponds to the whole protein P of rabies virus. The polyclonal antibody raised against this recombinant protein P was able to detect with high specificity, protein P in cultures of sensorial neurons infected with rabies virus. CONCLUSIONS: The P protein obtained from heterologous expression in Escherichia coli became a specific antigen that was used to produce a polyclonal antibody capable of detecting native P protein in rabies virus infected cells.

kDNA markers define two major Trypanosoma rangeli lineages in Latin-America.

Trypanosoma rangeli is a hemoflagellate parasite of man, domestic and wild animals in Central and South America. The genus Rhodnius is particularly susceptible to infection by T. rangeli and transmission by salivary inoculation has been demonstrated in 12 of 14 nominal species of naturally and experimentally infected insects. This report describes the molecular characterization of 37 strains of T. rangeli isolated from vertebrate and invertebrate hosts. Strains were analyzed by hybridization with kinetoplast DNA (kDNA) probes, polymerase chain reaction (PCR) amplification of kDNA minicircles and random amplification polymorphic DNA (RAPD). Strains isolated from Rhodnius prolixus present KP1, KP2 and KP3 minicircle amplification products but strains isolated from R. colombiensis or Panstrongylus megistus present amplification products derived only from KP2 and KP3 minicircles. The two T. rangeli groups defined as KP1(+) and KP1(-) present a high genetic divergence as they have probably been co-evolutioned with different adaptive radiated lines of the genus Rhodnius in Latin-America. The data obtained from insects with intestinal and salivary glands infections confirm that each Rhodnius species select the sub-population of T. rangeli KP1(+) or KP1(-) which is susceptible to transmit it by salivary inoculation to the vertebrate host.