INTERACTION BETWEEN THE HYPOXIA INDUCIBLE FACTOR 1 ALPHA AND THE HUMAN POLYOMAVIRUS BK: A RISK FACTOR FOR THE DEVELOPMENT OF POLYOMAVIRUS ASSOCIATED NEPHROPATHY

Polyomaviruses are nonenveloped viruses with an icosahedral capsid of about 40-45 nm in diameter. The human polyomavirus BK (BKV) is a member of the Polyomaviridae family detected in 1971 in the urine of an immunosuppressed renal transplant recipient who developed ureteric stenosis. BKV has a worldwide seroprevalence of about 90%. After the primary infection, BKV establishes a life-long latency within the urogenital tract. The severe immunological impairment occurring in transplant kidney recipients leads to BKV reactivation that may result in the polyomavirus associated nephropathy (PVAN). During transplantation, kidney is subjected to hypoxic conditions, driven by the action of Hypoxia Inducible Factor (HIF). It has been proved that HIF isoform-1\u3b1 (HIF-1\u3b1) may interact with several viruses, but till now there are no evidences regarding the interaction between BKV and HIF-1\u3b1. In the present study, we aimed to achieve a better understanding about the relation between BKV infection and hypoxia conditions in kidney cells in case of transplantation. Firstly, 17 kidney paraffin-embedded tissue samples were collected from kidney transplant patients, who developed or not PVAN (PVAN and NOT PVAN group) and from a control group in order to evaluate HIF-1\u3b1 expression levels in vivo. Total RNA was extracted from paraffin embedded tissues, reverse transcripted into cDNA and HIF-1\u3b1 expression was measured by means of a qualitative Real Time PCR. Then, in vitro experiments were conducted using the VERO cell line to evaluate the possible interaction between the BKV promoter and HIF-1\u3b1. Luciferase and Chromatin Immunoprecipitation (ChIP) assays were performed on BKV transfected VERO cells, to verify the interaction between the viral promoter and HIF-1\u3b1. In parallel, to clarify the nature of the interaction between HIF-1\u3b1 and the BKV promoter, the sequences were in silico analyzed using BLASTN 2.2.32+ software to find whether one or more hypoxia response elements (HRE) core sequences were present in the BKV promoters. Finally, the effect of hypoxia on BKV replication was assessed by evaluating BKV replication in BKV infected VERO cells, treated and not treated with the hypoxia mimic Cobalt Chloride (CoCl2). The HIF-1\u3b1 expression level resulted 13.6 folds higher in PVAN tissues than in the control group while no differences were observed between the NOT PVAN tissues and the control group. Luciferase assay showed that the presence of HIF-1\u3b1 stabilized the BKV promoter, increasing its activity from 2-folds to 6-folds (p<0.05) in transfected cells. ChIP assay showed a physical interaction between HIF-1\u3b1 and the BKV promoter. BLASTN analysis showed no match between HRE sequence and the BKV promoter sequences, confirming that no binding sites for HIF-1\u3b1 are present in the viral promoter. Finally, data obtained from BKV infected VERO cells revealed that BKV viral load was 5-fold increased in CoCl2 treated cells compared to not treated infected cells. These data, taken together, are significant to define the role of hypoxic stress in BKV replication after renal transplantation. In particular, it can be concluded that the replication of this opportunistic virus, mainly due to immunosuppressive therapy, is furthermore stimulated and favorite by HIF-1\u3b1 activation, driven by hypoxic conditions during transplantation. The experimental results suggested a hypothetical molecular mechanism underling this thesis, which can be outlined as follows: cellular response to hypoxic environment prevents HIF-1\u3b1 proteasomal degradation, allowing the creation of a HIF-1 active complex. This complex translocates to the nucleus where it binds to the BKV promoter, stimulating the transcription of viral genes and promoting the BKV replication. If confirmed by further experiments, this scenario may have important clinical implications: exposition to hypoxia during renal transplantation process should be considered as a crucial risk factor for the development of PVAN. These findings could be translated into clinical practice, replacing modulation of HIF system with ex-vivo organ preservation technologies, such as extra-corporeal membrane oxygenation, or considering HIF-1\u3b1 as a target to be inhibited, perhaps using RNA interference technology

Permeation of Ternary Mixture Containing H2S, CO2 and CH4 in Aquivion® Perfluorosulfonic Acid (PFSA) Ionomer Membranes

Aquivion (R) E87-12S Perfluorosulfonated acid ionomer material (PFSA) has been studied as a membrane technology for natural gas sweetening from CO2 , H2S due to its interesting chemical and mechanical stability and good separation performance for polar compounds in humid environments. In the present work, permeation of the H2S/CO2/CH4 ternary mixture in this short-side PFSA chain was investigated at pressures up to 10 bar, temperatures up to 50 degrees C, and in a range of relative humidity (RH) from 20% to 90%. The results obtain confirm the strong dependence of Aquivion (R) on water activity and temperature, and its ability to separate gases based on their water solubility without substantial differences between pure and mixed gas experiments. Indeed, even when tested in ternary mixture, the permeation behavior remains similar to that observed for pure components and binary mixtures. In particular, the permeability of H2S is higher than that of CO(2 )and methane CH4, reaching values of 500 Barrer at 50 degrees C and 80% RH, against 450 and 23 Barrer for the other two gases respectively. Additionally, when tested at higher pressures of up to 10 bar under humid conditions, the membrane properties remained largely unchanged, thus confirming the overall stability and durability of Aquivion (R) E87-12S in acid environments

Compounds with antioxidant activity as a supplement of media used for human semen cryopreservation: a narrative review

Sperm cryopreservation is an important technique in preserving male fertility. Several methods for semen and sperm cryopreservation are available; however, the quality of thawed spermatozoa is poor and this is due to different mechanisms during the freezing-thawing process, including temperature changes, crystal ice formation, osmotic stress and oxidative stress (OS). OS is the result of an overproduction of reactive oxygen species (ROS) that, if present in high concentration, can damage the cellular structures and impair sperm function. Modulation of OS is an important issue in human sperm freezing. A large group of antioxidant molecules is used in cryopreservation processes as a pharmacological strategy to counteract the oxidizing effects of preservation procedures and thus protect sperm quality. The main body of the review comprises the analysis of different studies, starting from 2000 up to the present, dealing with the effects of different antioxidant compounds, including natural extract, used as supplement of cryopreservation media. Many studies have reported several beneficial effects of antioxidants that are added during freezing-thawing protocols on sperm cryo-damages; however, these improvements are not always evident. Over the past decade, the attention has been mainly focused on the phytoextracts and natural extracts. Phytoextracts can be obtained by waste products, which are a rich source of compounds with strong antioxidant activity. Because these by-products can be used in the industrial, cosmetic, nutraceutical, and human and animal reproductive fields, this topic of research is worthwhile implementing. The freezing and thawing protocols still have many pitfalls and the quality of thawed spermatozoa is not satisfactory. For this reason, new strategies to minimize cyodamages and to increase sperm cryostability are advisable to guarantee better sperm function and survival, permitting successful future clinical application

Protection against oxidative damage of erythrocyte membrane by the flavonoid quercetin and its relation to iron chelating activity

AbstractIncubation of glutathione (GSH) depleted mouse erythrocytes with the oxidants phenylhydrazine, acrolein, divicine and isouramil resulted in the release of free iron and in lipid peroxidation and hemolysis. The addition of the flavonoid quercetin, which chelates iron and penetrates erythrocytes, resulted in remarkable protection against lipid peroxidation and hemolysis. The protection seems to be due to intracellular chelation of iron, since a semi-stoichiometric ratio between released iron and the amount of quercetin necessary to prevent lipid peroxidation and hemolysis was found. Incubation of GSH depleted human erythrocytes with divicine and isouramil did not induce lipid peroxidation and hemolysis in spite of a substantial release of iron. However, divicine and isouramil produced alterations of membrane proteins, such as spectrin and band 3, as well as formation of senescent cell antigen. The addition of quercetin prevented these alterations

Accidentes laborales en veterinarios rurales

El ejercicio de la Veterinaria está asociado a numerosos riesgos ocupacionales. Los objetivos de este trabajo fueron estimar la frecuencia de veterinarios rurales que tuvieron accidentes laborales (AL), describir tipo de lesión y elementos involucrados, factores asociados y ausencia laboral. Se desarrolló un censo en veterinarios rurales (N= 741) que asistieron a reuniones obligatorias de capacitación continua. La tasa de respuesta a un cuestionario estructurado anónimo fue del 75.8% (n= 562). El análisis de los datos incluyó: χ2, t de Student, correlación de Pearson y regresión logística. El 97,1% había sufrido accidentes durante el ejercicio profesional, el 59,6% había requerido atención médica y el 81,4% padecía alguna dolencia derivada de su trabajo. El 52,1% tuvo al menos un día de ausencia laboral debido a accidentes de trabajo (37,9 ± 51,7 días). Sexo, edad y antigüedad profesional estuvieron significativamente asociados con la ocurrencia de AL in labore. en el análisis bivariante, pero no en el multivariante, probablemente debido al muy bajo número de entrevistados que no sufrieron AL. Algunas características de los profesionales, unida a la especial naturaleza de los pacientes, la existencia de instalaciones inapropiadas para ejercer la práctica clínica en condiciones de campo y la necesidad de trasladarse en vehículos automotores para entrar en contacto con los pacientes pueden contribuir para que esta profesión tenga un alto riesgo laboral

Avaliação in vitro da atividade anti-leishmania da ivermectina e dipropionato de imidocarb sobre Leishmania braziliensis e Leishmania infantum

Orientadora: Profa. Dra. Iara José de Messias-Reason.Coorientador: Prof. Dr. Fabiano Borges Figueiredo e Dr. Gustavo GonçalvesDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Medicina Interna e Ciências da Saúde. Defesa : Curitiba, 20/12/2022Inclui referências: p.58-62Resumo: As leishmanioses compõem um grupo de doenças tropicais infecciosas, endêmicas e prioritárias globalmente. Frente à indisponibilidade vacinal, baixa disponibilidade, alto custo e toxicidade de fármacos, o uso de drogas comercializadas para tratamento de outras doenças, que não àquelas tradicionalmente propostas pelo fabricante, é desejável. Neste contexto destacam-se os fármacos Ivermectina (IVM) e Dipropionato de Imidocarb (DPI), cuja potencial atividade anti-leishmania pode ser investigada. O objetivo geral é avaliar a atividade anti-leishmania dos fármacos veterinários IVM e DPI. Os materiais e métodos compreendem experimentação in vitro, realizada por meio de teste de viabilidade das promastigotas (obtido pelo teste MTT) e amastigotas (obtido por leitura no equipamento Operetta®) de L. braziliensis e L. infantum frente aos fármacos, teste de citotoxicidade das linhagens celulares VERO e THP-1 frente aos fármacos. Para as formas amastigotas foi empregada a linhagem THP-1 como células hospedeiras. A curva de crescimento das promastigotas de L. braziliensis e L. infantum frente aos fármacos IVM e DPI foi realizada ao longo de oito dias consecutivos. Os resultados foram analisados com auxílio de testes estatísticos; p<0,05 representou diferença estatística significativa entre o teste e o grupo controle. A análise da viabilidade da IVM frente à promastigota de L. braziliensis e de L. infantum apresentou diferença estatística em todas as concentrações. A viabilidade do DPI frente à promastigota de L. braziliensis apresentou diferença estatística entre as concentrações de 100 e 1,23 ug/mL; e entre 100 a 3,7 ug/mL frente à promastigota de L. infantum. Quanto à citotoxicidade da IVM frente às células VERO, houve diferença em todas as concentrações; quanto ao DPI houve diferença estatística apenas na concentração de 333,33ug/mL. No teste de citotoxicidade da IVM frente às células THP-1 houve diferença estatística nas duas maiores concentrações, 100 e 33,33ug/mL; para DPI a análise mostrou não haver diferença nas diversas concentrações. Na análise da viabilidade das amastigotas de L. braziliensis com IVM, não houve diferença entre as concentrações testadas, diferentemente dos testes com amastigotas de L. infantum, em que houve diferença estatística das concentrações mais altas, 17 e 3,4ug/mL. Na viabilidade das amastigotas de L. braziliensis com DPI, houve diferença estatística nas concentrações 25, 5 e 1ug/mL; para amastigotas de L. infantum houve diferença nas concentrações de 25 e 5 ug/mL. A IVM foi eficaz contra os parasitos, porém tóxica contra as células; o DPI foi eficaz contra os parasitos e apresentou baixa toxicidade para as células. Conclui-se que o reposicionamento de DPI para o tratamento de leishmanioses causadas por L. braziliensis e L. infantum é promissor considerando a atividade anti-leishmania com baixa toxicidade demonstrada in vitro. Resultado esse inédito e promissor para futuros ensaios in vivo.Abstract: Leishmaniases make up a group of infectious, endemic and priority tropical diseases globally. Faced with vaccine unavailability, low availability, high cost and drug toxicity, the use of drugs marketed for the treatment of other diseases, other than those traditionally proposed by the manufacturer, is desirable. In this context, the drugs Ivermectin (IVM) and Imidocarb Dipropionate (DPI) stand out, whose potential anti-leishmania activity can be investigated. The general objective is to evaluate the anti-leishmanial activity of the veterinary drugs IVM and DPI. The materials and methods include in vitro experimentation, carried out by means of a viability test of promastigotes (obtained by the MTT test) and amastigotes (obtained by reading in the Operetta® equipment) of L. braziliensis and L. infantum against drugs, cytotoxicity test of VERO and THP-1 cell lines against drugs. For amastigotes, the THP-1 cell line was used as host cells. The growth curve of L. braziliensis and L. infantum promastigotes against the drugs IVM and DPI was carried out over eight consecutive days. The results were analyzed with the aid of statistical tests; p<0.05 represented a statistically significant difference between the test and the control group. The viability analysis of IVM against the promastigotes of L. braziliensis and L. infantum showed statistical difference in all concentrations. The viability of DPI against the promastigote of L. braziliensis showed statistical difference between the concentrations of 100 and 1.23 ug/mL; and between 100 and 3.7 ug/mL against the promastigotes of L. infantum. As for the cytotoxicity of IVM against VERO cells, there was difference in all concentrations; as for the DPI, there was a statistical difference only in the concentration of 333.33ug/mL. In the IVM cytotoxicity test against THP-1 cells, there was a statistical difference in the two highest concentrations, 100 and 33.33ug/mL; for DPI the analysis showed no difference in the different concentrations. In the viability analysis of L. braziliensis amastigotes with IVM, there was no difference between the tested concentrations, unlike the tests with L. infantum amastigotes, in which there was a statistical difference in the highest concentrations, 17 and 3.4ug/mL. In the viability of L. braziliensis amastigotes with DPI, there was statistical difference in the concentrations 25, 5 and 1ug/mL; for amastigotes of L. infantum there was a difference in the concentrations of 25 and 5 ug/mL. IVM was effective against parasites, but toxic against cells; DPI was effective against parasites and showed low toxicity to cells. It is concluded that the repositioning of DPI for the treatment of leishmaniasis caused by L. braziliensis and L. infantum is promising considering the anti-leishmanial activity with low toxicity demonstrated in vitro. This unprecedented and promising result for future in vivo tests