Dysregulation of the dopaminergic system secondary to traumatic brain injury: implications for mood and anxiety disorders.

Traumatic brain injury (TBI) represents a public health issue with a high mortality rate and severe neurological and psychiatric consequences. Mood and anxiety disorders are some of the most frequently reported. Primary and secondary damage can cause a loss of neurons and glial cells, leading to dysfunction of neuronal circuits, which can induce imbalances in many neurotransmitter systems. Monoaminergic systems, especially the dopaminergic system, are some of the most involved in the pathogenesis of neuropsychiatric and cognitive symptoms after TBI. In this work, we summarize the studies carried out in patients who have suffered TBI and describe alterations in the dopaminergic system, highlighting (1) dysfunction of the dopaminergic neuronal circuits caused by TBI, where modifications are shown in the dopamine transporter (DAT) and alterations in the expression of dopamine receptor 2 (D2R) in brain areas with dopaminergic innervation, thus establishing a hypodopaminergic state and (2) variations in the concentration of dopamine and its metabolites in biological fluids of post-TBI patients, such as elevated dopamine (DA) and alterations in homovanillic acid (HVA). On the other hand, we show a large number of reports of alterations in the dopaminergic system after a TBI in animal models, in which modifications in the levels of DA, DAT, and HVA have been reported, as well as alterations in the expression of tyrosine hydroxylase (TH). We also describe the biological pathways, neuronal circuits, and molecular mechanisms potentially involved in mood and anxiety disorders that occur after TBI and are associated with alterations of the dopaminergic system in clinical studies and animal models. We describe the changes that occur in the clinical picture of post-TBI patients, such as alterations in mood and anxiety associated with DAT activity in the striatum, the relationship between post-TBI major depressive disorders (MDD) with lower availability of the DA receptors D2R and D3R in the caudate and thalamus, as well as a decrease in the volume of the substantia nigra (SN) associated with anxiety symptoms. With these findings, we discuss the possible relationship between the disorders caused by alterations in the dopaminergic system in patients with TBI.

Cannabidiol attenuates hypersensitivity and oxidative stress after traumatic spinal cord injury in rats.

Neuropathic pain (NP) arises as a direct consequence of traumatic spinal cord injury (SCI), which leads to devastating consequences for people suffering from this condition since no specific treatment has been defined. One relevant mechanism in generating painful stimuli involves the direct participation of reactive oxygen species (ROS) at the cellular and subcellular levels. Cannabidiol (CBD) is one of the two most crucial cannabinoid components of the cannabis plant and has been proposed as a potential treatment for NP. Its antioxidant, neuroprotective and anti-inflammatory properties have been documented. However, there is insufficient evidence regarding CBD as treatment of NP induced by SCI or the mechanisms that underlie this effect. In this study, we evaluated the antinociceptive effect of CBD as an acute treatment after the nociceptive behaviors characteristic of NP were established (hypersensitivity threshold and hypersensitivity response). Furthermore, the participation of oxidative stress was determined by lipid peroxidation (LP) and glutathione concentration (GSH) in female Wistar rats with SCI. Acute treatment with CBD (2.5-20 mg/kg, i.p.) decreased nociceptive behaviors in a dose-dependent manner, decreased LP, and increased GSH concentration in injured tissue 15 days after injury. The findings of this study suggest that the antinociceptive effect induced by CBD is regulated by reducing oxidative stress by decreasing the LP and increasing the concentration of antioxidant (GSH) defenses.

An approach to cellular tropism of SARS-CoV-2 through protein-protein interaction and enrichment analysis.

COVID-19, caused by SARS-CoV-2, is a primarily pulmonary disease that can affect several organs, directly or indirectly. To date, there are many questions about the different pathological mechanisms. Here, we generate an approach to identify the cellular-level tropism of SARS-CoV-2 using human proteomics, virus-host interactions, and enrichment analysis. Through a network-based approach, the molecular context was visualized and analyzed. This procedure was also performed for SARS-CoV-1. We obtained proteomes and interactomes from 145 different cells corresponding to 57 different tissues. We discarded the cells without the proteins known for interacting with the virus, such as ACE2 or TMPRSS2. Of the remaining cells, a gradient of susceptibility to infection was observed. In addition, we identified proteins associated with the coagulation cascade that can be directly or indirectly affected by viral proteins. As a whole we identified 55 cells that could be potentially controlled by the virus, with different susceptibilities, mainly being pneumocytes, heart, kidney, liver, or small intestine cells. These results help to explain the molecular context and provide elements for possible treatments in the current situation. This strategy may be useful for other viruses, especially those with limited reported PPI, such as a new virus.

Presencia de bacterias en prótesis dentales durante el proceso de elaboración / Presence of bacteria in dental prostheses during the elaboration process

Existe una creciente preocupación sobre el tema de la infección cruzada en clínicas y laboratorios dentales. El laboratorio odontológico debe seguir normas de bioseguridad que garanticen a todo el equipo de salud la prevención de estas infecciones. Los técnicos que allí laboran corren el riesgo de exponer su cara a salpicaduras, así como a rocíos de sangre y saliva. Este estudio fue diseñado para saber si los laboratorios a los que recurrimos cumplen con estas normas de bioseguridad, y qué tan confiados podemos estar de la desinfección por parte de ellos, ya que las prótesis deberían estar desinfectadas correctamente antes de colocarlas en boca (AU)

There is growing concern about the issue of cross infection in dental clinics and laboratories. The dental laboratory must follow biosafety standards that guarantee the prevention of these infections to the entire health team. The technicians who work there run the risk of exposing their face to splashes and spray of blood and saliva. This study was designed to find out if the laboratories we use comply with these biosafety standards, and how confident we can be of their disinfection by them, since the prostheses should be properly disinfected before placing them in the mouth (AU)

Análisis bacteriológico de piezas de mano de alta velocidad utilizadas en la práctica clínica / Bacteriological analysis of high speed handpieces used in clinical practice

Los profesionales de la salud están expuestos a una gran variedad de microorganismos desde esporas, bacterias, hongos, virus y protozoarios que pueden encontrarse en la sangre y/o saliva de los pacientes. Cualquiera de estos microorganismos puede causar una enfermedad infectocontagiosa a través de pinchazos y/o salpicaduras producidas por el aerosol durante la práctica dental. Objetivo: Determinar la presencia bacteriana en las piezas de alta velocidad utilizadas en la práctica clínica. Material y métodos: Es un estudio experimental, observacional y transversal en el que se evaluó la contaminación de 30 piezas de alta velocidad utilizadas en la práctica clínica. Previo al estudio se efectuó una estandarización obteniendo una kappa del 0.85. Se realizó una base de datos en el programa SPSS versión 22, con el que se llevó a cabo el análisis descriptivo para determinar medidas de tendencia central. Resultados: 73.3% de las muestras analizadas tuvieron crecimiento bacteriano, entre las bacterias que se encontraron resultó que 54.5% de ellas fueron bacterias Gram positivas y el resto Gram negativas. La bacteria con mayor presencia en la muestra fue el Bacillus en 45.5% seguida del Streptococcus en 27.3%, el restante 27.2% fue Staphylococcus, Coccus y Streptobacillus. Conclusiones: El uso correcto de las piezas de alta, así como su desinfección en la consulta dental es de suma importancia, ya que nos ayudan a evitar contaminaciones cruzadas y a prevenir que dentro del área de trabajo se formen focos de infección (AU)

Health professionals are exposed to a wide variety of microorganisms from spores, bacteria, fungi, viruses and protozoa that can be found in the blood and/or saliva of patients. Any of these microorganisms can cause an infectious disease through punctures and / or splashes produced by the aerosol during dental practice.1,2 Objective: To determine the bacterial presence in the high-speed pieces used in clinical practice. Material and methods: It are an experimental, observational and transversal study; where the contamination of 30 high-speed pieces used in clinical practice was evaluated. Prior to the study, a standardization was made obtaining a kappa of 0.85. A database was made in the program SPSS version 22, with which the descriptive analysis was carried out to determine measures of central tendency. Results: 73.3% of the analyzed samples showed bacterial growth, among the bacteria that were found, 54.5% of them were gram-positive bacteria and the rest were gram-negative. The bacterium with the highest presence in the sample was for Bacillus in 45.5% followed by Streptococcus in 27.3%, the remaining 27.2% was for Staphylococcus, Coccus and Streptobacillus. Conclusions: The correct use of the discharging parts, as well as their disinfection in the dental practice is of the utmost importance as they help us to avoid cross contamination and to prevent foci of infection from forming within the work area (AU)