Recurrence of membranous nephropathy after kidney transplantation: A multicenter retrospective cohort study.

Membranous nephropathy (MN) is a leading cause of kidney failure worldwide and frequently recurs after transplant. Available data originated from small retrospective cohort studies or registry analyses; therefore, uncertainties remain on risk factors for MN recurrence and response to therapy. Within the Post-Transplant Glomerular Disease Consortium, we conducted a retrospective multicenter cohort study examining the MN recurrence rate, risk factors, and response to treatment. This study screened 22,921 patients across 3 continents and included 194 patients who underwent a kidney transplant due to biopsy-proven MN. The cumulative incidence of MN recurrence was 31% at 10 years posttransplant. Patients with a faster progression toward end-stage kidney disease were at higher risk of developing recurrent MN (hazard ratio [HR], 0.55 per decade; 95% confidence interval [CI], 0.35-0.88). Moreover, elevated pretransplant levels of anti-phospholipase A2 receptor (PLA2R) antibodies were strongly associated with recurrence (HR, 18.58; 95% CI, 5.37-64.27). Patients receiving rituximab for MN recurrence had a higher likelihood of achieving remission than patients receiving renin-angiotensin-aldosterone system inhibition alone. In sum, MN recurs in one-third of patients posttransplant, and measurement of serum anti-PLA2R antibody levels shortly before transplant could aid in risk-stratifying patients for MN recurrence. Moreover, patients receiving rituximab had a higher rate of treatment response.

Development and validation of a simple web-based tool for early prediction of COVID-19-associated death in kidney transplant recipients.

This analysis, using data from the Brazilian kidney transplant (KT) COVID-19 study, seeks to develop a prediction score to assist in COVID-19 risk stratification in KT recipients. In this study, 1379 patients (35 sites) were enrolled, and a machine learning approach was used to fit models in a derivation cohort. A reduced Elastic Net model was selected, and the accuracy to predict the 28-day fatality after the COVID-19 diagnosis, assessed by the area under the ROC curve (AUC-ROC), was confirmed in a validation cohort. The better calibration values were used to build the applicable ImAgeS score. The 28-day fatality rate was 17% (n = 235), which was associated with increasing age, hypertension and cardiovascular disease, higher body mass index, dyspnea, and use of mycophenolate acid or azathioprine. Higher kidney graft function, longer time of symptoms until COVID-19 diagnosis, presence of anosmia or coryza, and use of mTOR inhibitor were associated with reduced risk of death. The coefficients of the best model were used to build the predictive score, which achieved an AUC-ROC of 0.767 (95% CI 0.698-0.834) in the validation cohort. In conclusion, the easily applicable predictive model could assist health care practitioners in identifying non-hospitalized kidney transplant patients that may require more intensive monitoring. Trial registration: ClinicalTrials.gov NCT04494776.

Deep evolutionary origin of limb and fin regeneration.

Salamanders and lungfishes are the only sarcopterygians (lobe-finned vertebrates) capable of paired appendage regeneration, regardless of the amputation level. Among actinopterygians (ray-finned fishes), regeneration after amputation at the fin endoskeleton has only been demonstrated in polypterid fishes (Cladistia). Whether this ability evolved independently in sarcopterygians and actinopterygians or has a common origin remains unknown. Here we combine fin regeneration assays and comparative RNA-sequencing (RNA-seq) analysis of Polypterus and axolotl blastemas to provide support for a common origin of paired appendage regeneration in Osteichthyes (bony vertebrates). We show that, in addition to polypterids, regeneration after fin endoskeleton amputation occurs in extant representatives of 2 other nonteleost actinopterygians: the American paddlefish (Chondrostei) and the spotted gar (Holostei). Furthermore, we assessed regeneration in 4 teleost species and show that, with the exception of the blue gourami (Anabantidae), 3 species were capable of regenerating fins after endoskeleton amputation: the white convict and the oscar (Cichlidae), and the goldfish (Cyprinidae). Our comparative RNA-seq analysis of regenerating blastemas of axolotl and Polypterus reveals the activation of common genetic pathways and expression profiles, consistent with a shared genetic program of appendage regeneration. Comparison of RNA-seq data from early Polypterus blastema to single-cell RNA-seq data from axolotl limb bud and limb regeneration stages shows that Polypterus and axolotl share a regeneration-specific genetic program. Collectively, our findings support a deep evolutionary origin of paired appendage regeneration in Osteichthyes and provide an evolutionary framework for studies on the genetic basis of appendage regeneration.

Comparison of burst versus ramp antitachycardia pacing therapy for ventricular tachycardia: A meta-analysis.

Current guidelines recommend at least one attempt of defibrillator antitachycardia pacing (ATP) therapy, showing preference for burst therapy. The objective of this study is to compare ramp versus burst ATP therapy proportion of success and acceleration in treating spontaneous or induced ventricular tachycardia (VT). The review protocol was previously published in PROSPERO. Data synthesis and measures of heterogeneity (I2 ) was performed by CMA® software v.3 comparing proportions in both groups. Sensitivity analysis was performed as subgroup or meta-regression according to quality, clinical characteristics, and differences in design. Thirteen studies including 30,117 VT episodes in 1672 patients were analyzed. There was no significant difference in the proportion of success between burst and ramp therapy in spontaneous VT (odds ratio = 1.116; 95% confidence interval [CI] = 0.788-1.579; I2 = 89%). There was no significant difference in the proportion of success between burst and ramp therapy in induced VT (odds ratio = 0.820; 95% CI = 0.468-1.437; I2 = 93%). No significant difference was found in the proportion of acceleration between burst and ramp in spontaneous VT (odds ratio = 0.792; 95% CI = 0.476-1.317; I2 = 83%). No significant difference was found in the proportion of acceleration between burst and ramp in induced VT (odds ratio = 1.234; 95% CI = 0.802-1.898; I2 = 55%). Sensitivity analysis did not change main results. There is no difference in success or in acceleration proportion between burst or ramp ATP therapy irrespective if the VT was spontaneous or induced. Future implantable cardioverter defibrillator programming guidelines should offer both ATP therapies without preference in one of them.

Integrating high cell density cultures with adapted laboratory evolution for improved Gag-HA virus-like particles production in stable insect cell lines.

Stable insect cell lines are emerging as an alternative to the insect cell-baculovirus expression vector system (IC-BEVS) for protein expression, benefiting from being a virus-free, nonlytic system. Still, the titers achieved are considerably lower. In this study, stable insect (Sf-9 and High Five) cells producing Gag virus-like particles (VLPs) were first adapted to grow under hypothermic culture conditions (22°C instead of standard 27°C), and then pseudotyped with a model membrane protein (influenza hemagglutinin [HA]) for expression of Gag-HA VLPs. Adaptation to lower temperature led to an increase in protein titers of up to 12-fold for p24 (as proxy for Gag-VLP) and sixfold for HA, with adapted Sf-9 cells outperforming High Five cells. Resulting Gag-HA VLPs producer Sf-9 cells were cultured to high cell densities, that is, 100 × 106 cell/ml, using perfusion (ATF® 2) in 1 L stirred-tank bioreactors. Specific p24 and HA production rates were similar to those of batch culture, enabling to increase volumetric titers by 7-8-fold without compromising the assembly of Gag-HA VLPs. Importantly, the antigen (HA) quantity in VLPs generated using stable adapted cells in perfusion was ≈5-fold higher than that from IC-BEVS, with the added benefit of being a baculovirus-free system. This study demonstrates the potential of combining stable expression in insect cells adapted to hypothermic culture conditions with perfusion for improving Gag-HA VLPs production.

Production of high-quality SARS-CoV-2 antigens: Impact of bioprocess and storage on glycosylation, biophysical attributes, and ELISA serologic tests performance.

Serological assays are valuable tools to study SARS-CoV-2 spread and, importantly, to identify individuals that were already infected and would be potentially immune to a virus reinfection. SARS-CoV-2 Spike protein and its receptor binding domain (RBD) are the antigens with higher potential to develop SARS-CoV-2 serological assays. Moreover, structural studies of these antigens are key to understand the molecular basis for Spike interaction with angiotensin converting enzyme 2 receptor, hopefully enabling the development of COVID-19 therapeutics. Thus, it is urgent that significant amounts of this protein became available at the highest quality. In this study, we produced Spike and RBD in two human derived cell hosts: HEK293-E6 and Expi293F™. We evaluated the impact of different and scalable bioprocessing approaches on Spike and RBD production yields and, more importantly, on these antigens' quality attributes. Using negative and positive sera collected from human donors, we show an excellent performance of the produced antigens, assessed in serologic enzyme-linked immunosorbent assay (ELISA) tests, as denoted by the high specificity and sensitivity of the test. We show robust Spike productions with final yields of approx. 2 mg/L of culture that were maintained independently of the production scale or cell culture strategy. To the best of our knowledge, the final yield of 90 mg/L of culture obtained for RBD production, was the highest reported to date. An in-depth characterization of SARS-CoV-2 Spike and RBD proteins was performed, namely the antigen's oligomeric state, glycosylation profiles, and thermal stability during storage. The correlation of these quality attributes with ELISA performance show equivalent reactivity to SARS-CoV-2 positive serum, for all Spike and RBD produced, and for all storage conditions tested. Overall, we provide straightforward protocols to produce high-quality SARS-CoV-2 Spike and RBD antigens, that can be easily adapted to both academic and industrial settings; and integrate, for the first time, studies on the impact of bioprocess with an in-depth characterization of these proteins, correlating antigen's glycosylation and biophysical attributes to performance of COVID-19 serologic tests.

Latex membranes with methylene blue dye for antimicrobial photodynamic therapy.

The search for new materials that can be applied in the treatment of injured human tissues has led to the development of new dressings. Membranes have potential as dressing materials because they can be fitted to and interact with the tissue surface. In this study, we analyze the morphological properties and wettability of latex membranes, along with the incorporation of the photosensitizer methylene blue, in the context of the utility of the membranes in curative applications involving photodynamic therapy (PDT). It was observed that deposition of the photosensitizer into latex membranes increased both the surface roughness and wettability. Antifungal testing indicated that antimicrobial PDT assisted by the latex membranes incorporating methylene blue effectively inactivated Candida albicans.

Exploring the causes of the high incidence of delayed graft function after kidney transplantation in Brazil: a multicenter study.

This retrospective multicenter (n = 18) cohort study evaluated the incidence, risk factors, and the impact of delayed graft function (DGF) on 1-year kidney transplant (KT) outcomes. Of 3992 deceased donor KT performed in 2014-2015, the incidence of DGF was 54%, ranging from 29.9% to 87.7% among centers. Risk factors (lower-bound-95%CI OR upper-bound-95%CI ) were male gender (1.066 1.2491.463 ), diabetic kidney disease (1.053 1.2961.595 ), time on dialysis (1.005 1.0071.009 ), retransplantation (1.035 1.3971.885 ), preformed anti-HLA antibodies (1.011 1.3831.892 ), HLA mismatches (1.006 1.0661.130 ), donor age (1.011 1.0171.023 ), donor final serum creatinine (sCr) (1.239 1.3171.399 ), cold ischemia time (CIT) (1.031 1.0431.056 ), machine perfusion (0.401 0.5420.733 ), and induction therapy with rabbit antithymocyte globulin (rATG) (0.658 0.8000.973 ). Duration of DGF > 4 days was associated with inferior renal function and DGF > 14 days with the higher incidences of acute rejection, graft loss, and death. In conclusion, the incidence and duration of DGF were high and associated with inferior graft outcomes. While late referral and poor donor maintenance account for the high overall incidence of DGF, variability in donor and recipient selection, organ preservation method, and type of induction agent may account for the wide variation observed among transplant centers.

A scalable insect cell-based production process of the human recombinant BMX for in-vitro covalent ligand high-throughput screening.

Bone Marrow Tyrosine kinase in the chromosome X (BMX) is a TEC family kinase associated with numerous pathological pathways in cancer cells. Covalent inhibition of BMX activity holds promise as a therapeutic approach against cancer. To screen for potent and selective covalent BMX inhibitors, large quantities of highly pure BMX are normally required which is challenging with the currently available production and purification processes. Here, we developed a scalable production process for the human recombinant BMX (hrBMX) using the insect cell-baculovirus expression vector system. Comparable expression levels were obtained in small-scale shake flasks (13 mL) and in stirred-tank bioreactors (STB, 5 L). A two-step chromatographic-based process was implemented, reducing purification times by 75% when compared to traditional processes, while maintaining hrBMX stability. The final production yield was 24 mg of purified hrBMX per litter of cell culture, with a purity of > 99%. Product quality was assessed and confirmed through a series of biochemical and biophysical assays, including circular dichroism and dynamic light scattering. Overall, the platform herein developed was capable of generating 100 mg purified hrBMX from 5 L STB in just 34 days, thus having the potential to assist in-vitro covalent ligand high-throughput screening for BMX activity inhibition.

Yellow fever disease in a renal transplant recipient: Case report and literature review.

Yellow fever (YF) is a viral disease, with clinical presentation among immunosuppressed patients not fully understood. YF vaccination (YFV), a live vaccine, is contraindicated in patients receiving immunosuppressive treatment due to the risk of developing the disease after vaccination. We report a case of a 50-year-old male recipient who presented wild-type YF five years after a deceased donor kidney transplant. He lived in a YF endemic area and inadvertently received YFV. One day after YFV, the patient presented nausea, vomiting, fever, diarrhea, polyarthralgia, thrombocytopenia, and increased levels of liver function enzymes. The serological test was compatible with YF disease, and quantitative viral load confirmed the diagnosis of wild-type YF. The patient received supportive care for twelve days, with hospital discharge in good clinical condition and stable renal function. One month after discharge, the patient developed de novo donor-specific anti-HLA antibodies (DSA) and histological evidence of endothelial lesion, with a diagnosis of acute antibody-mediated rejection (AMR), treated with plasmapheresis and human IVIg therapy. Six months after therapy, he presented normal renal function with a reduction of DSA MFI. In the reported case, we observed a clinical wild-type YF diagnosed even after YF vaccine administration, with good clinical outcome. De novo DSA and AMR occurred after the recovering of disease, with an adequate response to therapy and preserved allograft function. We reviewed the published literature on YF and YFV in solid organ transplantation.

Diagnostic accuracy of intravascular ultrasound-derived minimal lumen area compared with fractional flow reserve--meta-analysis: pooled accuracy of IVUS luminal area versus FFR.

INTRODUCTION: Although intravascular ultrasound minimal luminal area (IVUS-MLA) is one of many anatomic determinants of lesion severity, it has been proposed as an alternative to fractional flow reserve (FFR) to assess severity of coronary artery disease. OBJECTIVE: Pool the diagnostic performance of IVUS-MLA and determine its overall accuracy to predict the functional significance of coronary disease using FFR (0.75 or 0.80) as the gold standard. METHODS: Studies comparing IVUS and FFR to establish the best MLA cutoff value that correlates with significant coronary stenosis were reviewed from a Medline search using the terms "fractional flow reserve" and "ultrasound." DerSimonian Laird method was applied to obtain pooled accuracy. RESULTS: Eleven clinical trials, including two left main (LM) trials (total N = 1,759 patients, 1,953 lesions) were included. The weighted overall mean MLA cutoff was 2.61 mm(2) in non-LM trials and 5.35 mm(2) in LM trials. For non-LM lesions, the pooled sensitivity of MLA was 0.79 (95% CI = 0.76-0.83) and specificity was 0.65 (95% CI = 0.62-0.67). Positive likelihood ratio (LR) was 2.26 (95% CI = 1.98-2.57) and LR- was 0.32 (95% CI = 0.24-0.44). Area under the summary receiver operator curve for all trials was 0.848. Pooled LM trials had better accuracy: sensitivity = 0.90, specificity = 0.90, LR+ = 8.79, and LR- = 0.120. CONCLUSION: Given its limited pooled accuracy, IVUS-MLA's impact on clinical decision in this scenario is low and may lead to misclassification in up to 20% of the lesions. Pooled analysis points toward lower MLA cutoffs than the ones used in current practice.

Post-Transplant Glomerulonephritis: Challenges and Solutions.

Glomeruli can be damaged in several conditions after kidney transplantation, with a potential impact on the graft function and survival. Primary glomerulonephritis, a group of glomerular immunological damage that results in variable histological patterns and clinical phenotypes, can occur in kidney transplant recipients as a recurrent or de novo condition. Specific immunologic conditions associated with kidney transplantation, such as acute rejection episodes, can act as an additional trigger after transplantation, impacting the incidence of these glomerulopathies. The post-transplant GN recurrence ranges from 3% to 15%, varying according to the GN subtype and post-transplant time, mainly occurring after 3-5 years of kidney transplantation. Advances in the knowledge of glomerulonephritis pathophysiology have provided new approaches to pre-transplant risk evaluation and post-transplant monitoring. Glomeruli can be affected by several systemic viral infections, such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), cytomegalovirus (CMV), and BK virus. The diagnosis of these infections, as well as the identification of possible complications associated with them, are important to minimize the negative impacts of these conditions on kidney transplant recipients' outcomes.

Post-transplant diabetes mellitus: risk factors and outcomes in a 5-year follow-up.

Introduction: Kidney transplantation is associated with an increased risk of posttransplant diabetes mellitus (PTDM), impacting recipient and graft survivals. The incidence of PTDM ranges from 15% to 30%, with most cases occurring in the first year post-transplant. Some clinical and laboratory characteristics pre- and post-transplant may be associated with a higher PTDM incidence in a more extended follow-up period. This study aimed to analyze the prevalence of PTDM among renal transplant recipients without previous DM diagnosis during a five-year post-transplant follow-up, as well as clinical and laboratory characteristics associated with a higher incidence of PTDM during this period. Material and methods: Single-center retrospective cohort including kidney transplant recipients older than 18 years with a functioning graft over six months of follow-up between January and December 2018. Exclusion criteria were recipients younger than 18 years at kidney transplantation, previous diabetes mellitus diagnosis, and death with a functioning graft or graft failure within six months post-transplant. Results: From 117 kidney transplants performed during the period, 71 (60.7%) fulfilled the inclusion criteria, 18 (25.3%) had PTDM diagnosis, and most (n=16, 88.9%) during the 1st year post-transplant. The need for insulin therapy during the hospital stay was significantly higher in the PTDM group (n=11, 61.1% vs. n=14, 26.4%, PTDM vs. non-PTDM). Other PTDM risk factors, such as older age, high body mass index, HLA mismatches, and cytomegalovirus or hepatitis C virus infections, were not associated with PTDM occurrence in this series. During 5-year post-transplant follow-up, the graft function remained stable in both groups. Conclusion: The accumulated incidence of PTDM in this series was similar to the reported in other studies. The perioperative hyperglycemia with the need for treatment with insulin before hospital discharge was associated with PTDM.

Oral Glucose Tolerance Test as a Risk Marker for Developing Post-Transplant Diabetes Mellitus.

INTRODUCTION: The incidence of post-transplant diabetes mellitus (PTDM) can reach 30% during the first 6 months after kidney transplantation (KT), increasing the risk of graft failure and mortality. There is no well-established biomarker for predicting PTDM occurrence. This study evaluated the association between the abnormal 2-hour oral glucose tolerance test (OGTT) and the PTDM incidence. METHODS: A retrospective single-center study, including adult kidney transplant recipients from deceased donors, was performed between March 2021 and June 2022. EXCLUSION CRITERIA: age <18 years; pretransplant diabetes mellitus (DM); death with a functioning graft; loss of follow-up and/or graft failure before 6 months post-transplant. The results of pretransplant OGTT, fasting (FPG), and afternoon plasma glucose levels at hospitalization and FPG in the first, second, and third months post-transplant were evaluated. For analysis, patients were grouped according to the PTDM diagnosis: PTDM and non-PTDM. RESULTS: From 164 KT performed in the period, 50 (30%) were included, most male (n = 34, 68%), with a mean age of 48.3 ± 12.5 years. Nine patients (18%) developed PTDM, 44% between 3 and 6 months. General characteristics and immunosuppressive therapy were similar between the groups. The mean FPG in the pretransplant OGTT was significantly higher in the PTDM group compared with the non-PTDM group (85.7 ± 7.9 vs 79.1 ± 8.2, P = .03). The number of patients classified as impaired glucose tolerance (IGT) on the pre-transplant OGTT was significantly higher in the PTDM group. CONCLUSION: IGT in the pretransplant OGTT was associated with PTDM cases in kidney transplant recipients without a previous diagnosis of DM.

A tentative list of reptilian fauna of Algeria and their conservation status.

Background: Algeria is situated at the crossroads between Europe and Africa. The northern part of the country is listed as an area of high biodiversity. Currently, the ecosystems (rivers, lakes, deserts, forests etc.) and the species are under more pressure than ever. The impact of humans is significant and many factors constitute a strong threat to this fauna, especially reptiles, which are the most vulnerable because of their low mobility. Thus, pollution, the drying up of wetlands and their conversion to agriculture have clearly affected the existence of many species. The herpetofauna of Algeria is one of the most diversified in the Mediterranean Basin, consisting of 104 species of which 16.98% are endemic. We suppose that the present list of reptilian fauna provided in this paper is not exhaustive and it is expected to include more species given the lack of research on reptiles in Algeria and its large area. New information: Our dataset contains information on reptile occurrences in Algeria. The dataset is based on original research by the staff of the Laboratory of Environmental Sciences and Agroecology of Chadli Bendjedid University in Algeria. The conservation status of all recorded species is given.

Impact of COVID-19 on anti-HLA antibodies in kidney transplantation.

The effects of COVID-19 on the immune profile of kidney transplant recipients are unknown. Immunosuppression adjustment during the illness can increase the risk for de novo donor-specific anti-HLA antibodies (DSA) and acute rejection episodes. This single-center retrospective study includes adult kidney transplant recipients diagnosed with COVID-19 between March 2020 and December 2022, screened for anti-HLA antibodies (AbHLA) pre-transplant and after COVID-19. Analyzed data comprised demographics, immunosuppressive therapy before and during the illness, hospitalization rate, and AbHLA specificity. Two hundred sixty-seven transplant recipients were included and divided according to the pre-transplant AbHLA profile: absent [PRA- (n = 206, 77%)], non-DSA (N = 46, 17%), and DSA+ (n = 15, 6%). The DSA+ group was younger (40.5 ± 16.5; PRA- 50.3 ± 13.4; non-DSA 49.3 ± 11.7 years; p = 0.02). The hospitalization rate was higher in groups with preformed AbHLA (DSA+ n = 8, 53%; non-DSA = 24, 52%; PRA- n = 54, 26%; p < 0.01). Immunosuppression was maintained in 222 (83%), withdrawn in 33 (12%), and reduced in 11 (4%) cases without difference among groups. Twenty-two (8%) cases of de novo DSA were observed after COVID-19 [PRA-, n = 16 (73%) and non-DSA, n = 6 (27%)]. In the DSA+ group, the AbHLA profile remained stable. There were 6 (2%) cases of post-COVID-19 antibody-mediated rejection (DSA+ n = 4, 66%; non-DSA n = 1, 17%, PRA- n = 1, 17%) without T cell-mediated rejection cases. Post-COVID-19 de novo DSA was more frequent in groups without pre-transplant AbHLA, not having association with changes in immunosuppressive therapy.

Factors influencing the work of researchers in Scientific Initiation: A systematic review protocol.

INTRODUCTION: Scientific Initiation (SI) is an educational activity that allows students to begin their scientific training and research under the guidance of an experienced researcher. While several studies have examined students' perceptions of SI, research on the perspective of researchers working in this field is currently lacking. Thus, this study's aim is to describe the protocol design for conducting a systematic review. At the same time, the review aims also to identify factors influencing the work of researchers in SI and explore the motivations leading researchers to engage in research projects within institutions and their respective impacts. METHOD AND ANALYSES: Literature search will be done using the bibliographic databases, including Academic Search Premier, APA PsycNet, CINAHL Plus, ERIC, SocINDEX, Scopus, and Web of Science. The search strategy was guided by the PICo framework (Population, phenomenon of Interest, and Context). The preparation and development of this protocol following guidelines were employed: Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols 2015 (PRISMA-P 2015), Peer Review of Electronic Search Strategies 2015 (PRESS 2015), and PRISMA-Search (PRISMA-S). Original, peer-reviewed articles that examine the factors related to the work of researchers in SI will be included without any language or publication date restrictions. Qualitative, quantitative, and mixed-methods studies will be screened by two independent researchers. The included studies will be analyzed to identify factors, policies, and their impacts obtained analytically. Findings will be objectively categorized and synthetically represented through figures, diagrams, and graphic models. The risk of bias will be assessed using the Critical Appraisal Skills Program (CASP) and the Downs and Black checklists. A third senior reviewer will resolve any discrepancies. DISCUSSION: We aim to understand the factors that drive researchers to engage in SI research through the dissemination of the findings of this systematic review. This may aid the development of institutional strategies and actions that can support the enhancement of SI programs and encourage greater researcher participation.

Carbon monoxide modulates apoptosis by reinforcing oxidative metabolism in astrocytes: role of Bcl-2.

Modulation of cerebral cell metabolism for improving the outcome of hypoxia-ischemia and reperfusion is a strategy yet to be explored. Because carbon monoxide (CO) is known to prevent cerebral cell death; herein the role of CO in the modulation of astrocytic metabolism, in particular, at the level of mitochondria was investigated. Low concentrations of CO partially inhibited oxidative stress-induced apoptosis in astrocytes, by preventing caspase-3 activation, mitochondrial potential depolarization, and plasmatic membrane permeability. CO exposure enhanced intracellular ATP generation, which was accompanied by an increase on specific oxygen consumption, a decrease on lactate production, and a reduction of glucose use, indicating an improvement of oxidative phosphorylation. Accordingly, CO increased cytochrome c oxidase (COX) enzymatic specific activity and stimulated mitochondrial biogenesis. In astrocytes, COX interacts with Bcl-2, which was verified by immunoprecipitation; this interaction is superior after 24 h of CO treatment. Furthermore, CO enhanced Bcl-2 expression in astrocytes. By silencing Bcl-2 expression with siRNA transfection, CO effects in astrocytes were prevented, namely: (i) inhibition of apoptosis, (ii) increase on ATP generation, (iii) stimulation of COX activity, and (iv) mitochondrial biogenesis. Thus, Bcl-2 expression is crucial for CO modulation of oxidative metabolism and for conferring cytoprotection. In conclusion, CO protects astrocytes against oxidative stress-induced apoptosis by improving metabolism functioning, particularly mitochondrial oxidative phosphorylation.

Carboxylesterase 2 production and characterization in human cells: new insights into enzyme oligomerization and activity.

Carboxylesterase 2 (CES2), the main carboxylesterase expressed in human intestine, is an increasingly important enzyme in anti-cancer combined therapies for the treatment of different pathologies like colon adenocarcinoma and malignant glioma. The production of human recombinant CES2, in human embryonic kidney cells (HEK-293T cells) using serum-free media, is herein described. CES2 secretion to the media was achieved by the simple addition of an in-frame C-terminal 10× histidine tag (CES2-10xHis) without the need of addition of extra N-terminal signalling sequences or the mutation or deletion of the C-terminal HTEL motif responsible for retaining the protein in the lumen of endoplasmic reticulum. This secretion allowed a fourfold increase in CES2 production. The characterization of human recombinant CES2 showed that this protein exists in other active and inactive forms than the described 60 kDa monomer.