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To evaluate factors affecting corneal endothelial cell density (ECD) under enucleation and preservation time studies at Eye Bank of the Federal District of Brazil. We conducted a case–control study collecting data from 1128 corneas where death-to-enucleation time and enucleation-to-preservation time were within 24 h. Low cell count were those corneas with an ECD less than 2000 cells/mm2 and high cell count was defined as those with ECD greater than 2000 cells/mm2. We calculated the independent risk factors related to: cause of death, donor age, death-to-enucleation time, enucleation-to-preservation time and primary graft failure. Correlation analysis was used to assess which parameters influence ECD: death-to-enucleation time, enucleation-to-preservation time, average cell area (AVE), coefficient of variation and percentage of hexagonal cells. Of the total number of corneas, 1004 had ECD data and were selected for the study. 87.4% (n = 877) had high cell counts with 2699 ± 412 cells/mm2. The mean donor age was 38.8 ± 16 years. The most common causes of death were external causes (48.6%, n = 488). Longer times from death-to-enucleation, up to 24 h were not associated with a decrease in ECD (OR 0.58; P = 0.44) or risk of graft survival (P = 0.74). Enucleation-to-preservation intervals greater than 12 h showed increased risk of graft survival (P = 0.04). AVE was the main parameter for ECD (R2 = 0.96, P

To evaluate factors affecting corneal endothelial cell density (ECD) under enucleation and preservation time studies at Eye Bank of the Federal District of Brazil. We conducted a case-control study collecting data from 1128 corneas where death-to-enucleation time and enucleation-to-preservation time were within 24 h. Low cell count were those corneas with an ECD less than 2000 cells/mm

Trauma is a leading cause of death and disability worldwide. Corneal tissue donors generally are those who suffered an injury to the brain or fatal trauma caused by stroke, vehicle/motorbike accidents, gunshot wounds, and drowning or cardiovascular death. In Brazil, the Distrito Federal (DF) Eye Bank, located within a trauma center hospital, and the Secretariat of Public Security have collaborated with the aim of increasing the overall number of cornea donations from fatal trauma victims. The purpose of this study was to determine the suitability of cornea tissue for transplantation derived from trauma-related death. The records of eyes donated in the DF Eye Bank were analyzed retrospectively for the period from 2004-2013. We had 3388 cornea donors, the majority of which were between 21 and 30 years old (17.4%), which were derived from violent death (84.1%; P = .00) and were predominately male (73.5%). Among the donated corneas, 54.0% were used for optic purposes. Mechanical trauma caused by gunshot, stabbing or blunt force (23.7%), and road traffic injuries (11%) were the main causes of violent death. Another common cause of death was cardiovascular disease (26.3%). Donor tissue derived from violent death had no statistical interference on tissue suitability for transplantation (P = .06). Because of the large waiting lists, and waiting times for transplants, it is advisable to increase the available tissue from corneas donors derived from violent death through the implementation of this interagency model of collaboration and by the practicing of active tissue donor screening in trauma center hospitals.

Nef proteins from all primate Lentiviruses, including the simian immunodeficiency virus of chimpanzees (SIVcpz), increase viral progeny infectivity. However, the function of Nef involved with the increase in viral infectivity is still not completely understood. Nonetheless, until now, studies investigating the functions of Nef from SIVcpz have been conducted in the context of the HIV-1 proviruses. In an attempt to investigate the role played by Nef during the replication cycle of an SIVcpz, a Nef-defective derivative was obtained from the SIVcpzWTGab2 clone by introducing a frame shift mutation at a unique restriction site within the nef sequence. This nef-deleted clone expresses an N-terminal 74-amino acid truncated peptide of Nef and was named SIVcpz-tNef. We found that the SIVcpz-tNef does not behave as a classic nef-deleted HIV-1 or simian immunodeficiency virus of macaques SIVmac. Markedly, SIVcpz-tNef progeny from both Hek-293T and Molt producer cells were completely non-infectious. Moreover, the loss in infectivity of SIVcpz-tNef correlated with the inhibition of Gag and GagPol processing. A marked accumulation of Gag and very low levels of reverse transcriptase were detected in viral lysates. Furthermore, these observations were reproduced once the tNef peptide was expressed in trans both in SIVcpzΔNef and HIV-1WT expressing cells, demonstrating that the truncated peptide is a dominant negative for viral processing and infectivity for both SIVcpz and HIV-1. We demonstrated that the truncated Nef peptide binds to GagPol outside the protease region and by doing so probably blocks processing of both GagPol and Gag precursors at a very early stage. This study demonstrates for the first time that naturally-occurring Nef peptides can potently block lentiviral processing and infectivity.

Vital to patient safety is the accurate assessment and minimization of risk for human immunodeficiency virus (HIV), Hepatitis C (HCV), and Hepatitis B (HBV) virus transmission by deceased donor organ and tissue transplantation. The pathogens are tested by serological kits based on enzyme-linked immunosorbent assay (ELISA), chemiluminescence (CLIA) and eletrochemiluminescence (ECLIA) immunoassays. Organ transplantation is a highly successful life-saving treatment in Brazil, but the Brazilian Health Surveillance Agency currently mandates that all deceased organ donors are screened for HIV, HCV and HBV following living donor policies. In this review, six ELISA (Wama®, Bio-Rad®, Biomerieux®, DiaSorin®, Acon Biotech® and Biokit®), three CLIA (Abbott®, Siemens®, Diasorin®) and one ECLIA (Roche®) were utilized for evaluating the effectiveness of those serological tests for deceased donors in Brazil according to manufacturer's guidelines. NAT for HIV, HCV and HBV can assist with detection of pre-seroconversion for those infections, and only Cobas® TaqScreen MPX® test, the Tigris System® Procleix Ultrio Assay® and the Bio-Manguinhos® HIV/HCV/HBV NAT are commercially available. Between all the tests, only the manufacturer Abbott® and Cobas® TaqScreen MPX® test are currently validated for cadaver samples.

Human and Simian Immunodeficiency Viruses (HIV and SIV) are the etiological agents of the Acquired Immunodeficiency Syndrome (AIDS) in humans and the Simian AIDS (SAIDS) in macaques, respectively. HIVs and SIVs are members of the Retroviridae family, Lentivirus genera, and are considered complex retroviruses since its genome organization predicts the presence of at least 6 open reading frames (ORFs) in addition to the main Gag, Pol and Env ORFs present in the genomes of all retroviruses. These additional ORFs code for both regulatory (Tat and Rev) and accessory (Nef, Vif, Vpr, Vpu and Vpx) viral proteins and are all organized from the 5’ half of the genome in a way that overlap both with each other and with the Pol and Env ORFs and the non-coding 3’ Long Terminal Repeat (LTR) region (Figure 1). To ensure its expression and to achieve an optimal production of the viral progeny, complex mechanisms have evolved in these viruses that tightly control the expression of these ORFs during the viral replication cycle. The existence of such a number of viral proteins in addition to the viral structural (Gag and Env) and enzymatic (Pol) proteins allows the virus to explore new mechanisms to control the different steps of the replication cycle and to avoid the host cell defense. In this chapter we shall review the different steps of the HIV and SIV replication cycle with emphasis in the role taken by the viral accessory protein Nef, in both subverting the host cell machinery and influencing the function and activation of viral structural and enzymatic proteins in order to optimize viral progeny production as well as in evading the host cell defenses. Lentiviral accessory proteins Vif, Vpr, Vpu and Nef were classically regarded as nonessential for virus production and/or infectivity since laboratory adapted HIV strains lacking the expression of these proteins could still replicate to several levels (Adachi et al., 1991). Since then, several studies demonstrated the crucial importance of these proteins to the efficient replication, infectivity and spread of both HIV and SIV (Kirchhoff, 2010). Vif (Aguiar and Peterlin, 2008) and Vpu (Adachi et al., 1991) have now been acknowledged as crucial viral factors that counteract the host cell innate defense. Vif interacts and prompts the degradation of a family of cytidine deaminases DNA/RNA editing enzymes, known as Apoliprotein B mRNA-editing Enzymes (APOBECs), that otherwise would inhibit HIV and SIV replication by causing hypermutation of nascent