Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with humans to a greater or lesser extent, and can generate adverse effects such as cellular stress when interacting with intra-and extracellular biomolecules. The skin is the first organ in contact with UV radiation, and the stress it generates can be analyzed by the expression of a bioindicator of cellular damage such as Hsp70. Therefore, the objective of the project was: to determine the effect of UVA, UVB and UVC radiation on HaCaT epithelial cells, by analyzing the expression of Hsp70. Materials and methods: HaCaT cells were cultured in vitro, which were irradiated with UVA, UVB and UVC light at different doses, to subsequently determine the degree of Hsp70 expression by Immunodetection by PAGE-SDS and Western Blot. Results: Basal expression of Hsp70 was observed in no irradiated HaCaT cells. When HaCaT cells were irradiated with UVA, UVB, UVC, an increase in this Hsp70 protein was observed. With UVA, a higher degree of expression was observed at a time of 30 minutes of irradiation. With UVB the highest expression shifted to a time of 20 minutes. With UVC, overexpression was observed after 10 minutes. Conclusion: UV radiation generates cellular stress on HaCaT cells, evaluated by the stress bioindicator Hsp70. According to the wavelength of UV radiation, those that have a shorter wavelength have a greater potential for cellular damage, such as UVC.

Evaluation of Clinical Characteristics and Plasma Cortisol Concentrations in Individuals with COVID-19 and Post-COVID Syndrome

COVID-19 generates systematic alterations in humans both in active stages of infection and over time, called post-COVID syndrome. Cortisol is a hormone that is overexpressed in inflammation and cellular stress processes. Its main function is to return to physiological homeostasis, so its evaluation together with other clinical parameters can allow us to determine the degree of systemic affectation by COVID-19. Objective: To evaluate changes in clinical parameters and plasma cortisol concentrations in patients with active COVID-19 and post-COVID syndrome. Material and Methods: Healthy patients, in stages of mild infection, critical and with post-COVID syndrome, were recruited, obtaining, through clinical diagnoses and interviews, their main clinical characteristics, in addition to plasma, in which cortisol concentrations were determined using competitive ELISA. Results: The critical stage group had higher frequencies of comorbidities, clinical symptoms, as well as more altered laboratory parameters compared to the other subgroups. In the post-COVID syndrome group after the initial infection, most laboratory parameters recovered, however, several clinical symptoms remained latent over time. The determination of cortisol showed an increase in its concentration, being higher in patients in critical stage and with post-COVID syndrome. Conclusion: COVID-19 disease generates clinical alterations that trigger an increase in plasma cortisol. These alterations increase as the stages of infection become more severe and some of them remain altered in patients with post-COVID syndrome.

Enhancing survival, engraftment, and osteogenic potential of mesenchymal stem cells

Mesenchymal stem cells(MSCs)are promising candidates for bone regeneration therapies due to their plasticity and easiness of sourcing.MSC-based treatments are generally considered a safe procedure,however,the long-term results obtained up to now are far from satisfactory.The main causes of these therapeutic limitations are inefficient homing,engraftment,and osteogenic differentiation.Many studies have proposed modifications to improve MSC engraftment and osteogenic differentiation of the transplanted cells.Several strategies are aimed to improve cell resistance to the hostile microenvironment found in the recipient tissue and increase cell survival after transplantation.These strategies could range from a simple modification of the culture conditions,known as cell-preconditioning,to the genetic modification of the cells to avoid cellular senescence.Many efforts have also been done in order to enhance the osteogenic potential of the transplanted cells and induce bone formation,mainly by the use of bioactive or biomimetic scaffolds,although alternative approaches will also be discussed.This review aims to summarize several of the most recent approaches,providing an up-to-date view of the main developments in MSCbased regenerative techniques.

Mechanisms of autophagy and apoptosis:Recent developments in breast cancer cells

Autophagy,the pathway whereby cell components are degraded by lysosomes,is involved in the cell response to environmental stresses,such as nutrient deprivation,hypoxia or exposition to chemotherapeutic agents.Under these conditions,which are reminiscent of certain phases of tumor development,autophagy either promotes cell survival or induces cell death. This strengthens the possibility that autophagy could be an important target in cancer therapy,as has been proposed.Here,we describe the regulation of survival and death by autophagy and apoptosis,especially in cultured breast cancer cells.In particular,we discuss whether autophagy represents an apoptosis-independent process and/or if they share common pathways. We believe that understanding in detail the molecular mechanisms that underlie the relationships between autophagy and apoptosis in breast cancer cells could improve the available treatments for this disease.

Presence of <i>Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae</i>in upper respiratory tract of swine in farms from Aguascalientes, Mexico

Respiratory diseases are one of the most important health problems in pig herds. The porcine respiratory disease complex (PRDC) is the term used to describe pneumonic diseases caused by multiple infectious agents that provoke weight loss in animals or death. In the PRDC multiple pathogens (bacteria and/or viruses) work in combination to induce this respiratory disease. Within this complex, Actinobacillus pleuropneumoniae, Streptococcus suis, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis and Mycoplasma hyopneumoniae are the main bacterial pathogens involved in great economic losses to the swine industry. The aim of this work was to estimate the presence of A. pleuropneumoniae, S. suis, P. multocida, B. bronchiseptica, H. parasuis and M. hyopneumoniae in the upper respiratory tract of pigs in representative swine farms inAguascalientes,Mexico, using PCR technique. The study was performed in 14 swine farms. We obtained a total of 212 nasal swabs. Near 20% of samples were positive for A. pleuropneumoniae (located in the 79% of farms);17% were positive for S. suis (in 86% of farms), of these, 3% were S. suis serovar 2;30% were positive for H. parasuis (93% of farms);23% of the samples to P. multocida (in 79% of farms);and 19% to M. hyopneumoniae (in 64% of farms). B. bronchiseptica was not detected in this study. The results obtained show that bacterial pathogens of PRDC were present in the upper respiratory tract of pigs in all farms studied;therefore, these pathogens are widely disseminated in pig farms of Aguascalientes, Mexico.

Porcine Respiratory Pathogens in Swine Farms Environment in Mexico

Respiratory pathogens are the main health problem in the swine industry worldwide. These pathogens are transmitted by direct contact between animals or by aerosols and however are not well known yet, if the environment works as its reservoir, inoculum and/or dispersion medium. The objective of this study was to determine the presence of respiratory pathogens in environmental samples from swine farms in Aguascalientes, Mexico, through of PCR and RT-PCR techniques. The bacteria Actinobacillus pleuropneumoniae and Pasteurella multocida were found viable in samples from water, food, soil and air. Streptococcus suis was found in a viable state in water samples. Haemophilus parasuis, Porcine Reproductive and Respiratory Syndrome virus and Swine Influenza virus (H1N1 and H3N2) were detected in drinking water samples. Mycoplasma hyopneumoniae and Porcine Circovirus type 2 (PCV2) were not detected in environmental samples. These results suggest that the environment of the farms acts as a reservoir, inoculum and/or vehicle of dispersion for these pathogens except for M. hyopneumoniae and PCV2.

Thermal preference, tolerance and temperature-dependent respiration in the California sea hare <i>Aplysia californica</i>

The thermoregulatory behavior of sea hare Aplysia californica was determined in a horizontal thermal gradient;with a preferred temperature (PT) of 18.3°C for the day cycle and 20.8°C for the night cycle. The displacement velocity demonstrated an initial rate of 30 cm·hˉ1 and gradually the velocity diminished to 18 cm·hˉ1 with several fluctuations mainly at 02:00 am. Critical Temperature Maxima (CTMax refers to the temperature point where at least 50% of the experimental group have a loss of attachment) was measured at three acclimation temperatures (16°C, 19°C and 22°C). At the lowest acclimation temperature (16°C), 50% of the experimental group had an attachment loss at CTMax 32.7°C, and in a higher acclimation temperature (22°C) CTMax was 36.2°C. The Oxygen Consumption Rate (OCR) was closely correlated to acclimation temperature, and at 16°C and 19°C sea hare had a relatively stable metabolic rate, with OCR increasing to 9 mg O2 hˉ1·kgˉ1 w.w. in a higher acclimation temperature.

Unilateral Impact of Altered Loading by Changing Teeth Height on the TMJ Fibrocartilage: Disc and Condyle of Wistar Rats

Temporomandibular joint (TMJ) is sensitive to loading and mechanical stress that provokes morphological changes produced by the impact in the occlusal plane. Here, this impact is evaluated in TMJ articular disc and articular cartilage using an in vivo model of unilateral occlusal plane impact and by analysis of serial tissue sections stained with Hematoxylin-Eosin (H-E) or with Masson trichrome technique. Thus, six groups of 5 Wistar rats (200 - 250 g) are subjected to biomechanical dental stimulation by placing unilateral resin occlusal interference, or unilateral tooth wear made by upper left molars artificial mechanical devastation (1 control and 2 experimental groups for each treatment). Each treatment is evaluated two times at 1 and 15 days post-treatment. By H-E staining, control groups show chondrocytes arrangement as several cord cell groups in comparison with the experimental groups, which show an arrangement in one cord cell along of articular disc. However, this yields no significant difference (p < 0.05) in cell number between control and experimental groups. In contrast, in articular cartilage chondrocytes are random distributed along the superficial zone in control groups, while in experimental groups cell-free regions are observed in superficial zone. An image Blue hue analysis for trichrome stain is performed to quantify collagen;this shows a significant collagen decrease (p < 0.05) in almost all experimental groups compared with the controls. A degenerative process biomechanically induced by unilateral occlusal plane modification, causes cell and tissue changes on the TMJ structures that remain the degenerative changes observed in early osteoarthritis.

Low-Dose Gamma Radiation Fields Decrease Cell Viability, Damage DNA, and Increase the Expression of Hsp70 and p53 Proteins in Human Leukocytes

Ionizing radiations are tools in diagnosis and treatment of diseases. Leukopenia from exposure to ionizing radiation has been reported. Due to their radiosensitivity, leukocytes are a biological model to analyze cell damage. Therefore, cell viability, DNA damage, and Hsp70 and p53 expression in human leukocytes exposed to low-dose gamma radiation fields from a 137Cs source were evaluated. A decrease in cell viability, DNA damage and an increase in the expression of Hsp70 and p53 proportional to the radiation dose received was found, which was 0.2, 0.4, 0.6, 0.8 and 1.0 mGy.