Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized

Breakthrough candidemia after the introduction of broad spectrum antifungal agents: A 5-year retrospective study

Candidemia is the main invasive fungal disease among hospitalized patients. Several breakthrough candidemia (BrC) cases have been reported, but few studies evaluate the epidemiology, risk factors, molecular characterization, antifungal susceptibility profile and outcome of those patients, especially in developing countries and including patients using broad spectrum antifungals. We conducted a retrospective study from 2011 to 2016, including patients aged 12 years or older with candidemia. Epidemiological characteristics and risk factors for candidemia were evaluated and compared with patients with BrC using univariate and multivariate analysis. Sequential Candida isolates from BrC were identified by internal transcribed spacer sequencing, genotyped with amplified fragment length polymorphism fingerprinting (AFLP), and tested for antifungal susceptibility. From 148 candidemia episodes, 27 breakthrough episodes (18%) were identified, with neutropenia and mucositis being independent risk factors for BrC. Candida non-albicans was more frequent in the BrC group (P < .001). AFLP showed high correlation with conventional methods of identification among breakthrough isolates and a high genetic similarity among isolates from the same patient was observed. C. albicans was the most susceptible species with low MIC values for all antifungal agents tested. In contrast, we found isolates of C. glabrata, C. parapsilosis and C. tropicalis resistant to triazoles and echinocandins. In conclusion, BrC occurred mainly in severely immunosuppressed patients, with neutropenia and mucositis. Mortality did not differ between the groups. Candida non-albicans species were more recovered from BrC, with C. albicans being the most susceptible to antifungals

Cost-Effectiveness of Rheumatic Heart Disease Echocardiographic Screening in Brazil : Data from the PROVAR+ Study

Introduction: In recent years, new technologies - noticeably ultra-portable echocardiographic machines - have emerged, allowing for Rheumatic Heart Disease (RHD) early diagnosis. We aimed to perform a cost-utility analysis to assess the cost-effectiveness of RHD screening with handheld devices in the Brazilian context. Methods: A Markov model was created to assess the cost-effectiveness of one-time screening for RHD in a hypothetical cohort of 11-year-old socioeconomically disadvantaged children, comparing the intervention to standard care using a public perspective and a 30-year time horizon. The model consisted of 13 states: No RHD, Undiagnosed Asymptomatic Borderline RHD, Diagnosed Asymptomatic Borderline RHD, Untreated Asymptomatic Definite RHD, Treated Asymptomatic Definite RHD, Untreated Mild Clinical RHD, Treated Mild Clinical RHD, Untreated Severe Clinical RHD, Treated Severe Clinical RHD, Surgery, Post-Surgery and Death. The initial distribution of the population over the different states was derived from primary echo screening data. Costs of the different states were derived from the Brazilian public health system database. Transition probabilities and utilities were derived from published studies. A discount rate of 3%/year was used. A cost-effectiveness threshold of $25,949.85 per Disability Adjusted Life Year (DALY) averted is used in concordance with the 3x GDP per capita threshold in 2015. Results: RHD echo screening is cost-effective with an Incremental Cost-Effectiveness Ratio of$10,148.38 per DALY averted. Probabilistic modelling shows that the intervention could be considered cost-effective in 70% of the iterations. Conclusion: Screening for RHD with hand held echocardiographic machines in 11-year-old children in the target population is cost-effective in the Brazilian context. Highlights: A cost-effectiveness analysis showed that Rheumatic Heart Disease (RHD) echocardiographic screening utilizing handheld devices, performed by non-physicians with remote interpretation by telemedicine is cost-effective in a 30-year time horizon in Brazil.The model included primary data from the first large-scale RHD screening program in Brazilian underserved populations and costs from the Unified Health System (SUS), and suggests that the Incremental Cost-Effectiveness Ratio of the intervention is considerably below the acceptable threshold for Brazil, even after a detailed sensitivity analysis.Considering the high prevalence of subclinical RHD in Brazil, and the significant economic burden posed by advanced disease, these data are important for the formulation of public policies and surveillance approaches.Cost-saving strategies first implemented in Brazil by the PROVAR study, such as task-shifting to non-physicians, computer-based training, routine use of affordable devices and telemedicine for remote diagnosis may help planning RHD control programs in endemic areas worldwide.On behalf of the PROVAR+ (Programa de RastreamentO da VAlvopatia Reumática e Outras Doenças Cardiovasculares) investigators</p

B Chromosomes in Psalidodon scabripinnis (Characiformes, Characidae) Species Complex

B chromosomes are extra-genomic components of cells found in individuals and in populations of some eukaryotic organisms. They have been described since the first observations of chromosomes, but several aspects of their biology remain enigmatic. Despite being present in hundreds of fungi, plants, and animal species, only a small number of B chromosomes have been investigated through high-throughput analyses, revealing the remarkable mechanisms employed by these elements to ensure their maintenance. Populations of the Psalidodon scabripinnis species complex exhibit great B chromosome diversity, making them a useful material for various analyses. In recent years, important aspects of their biology have been revealed. Here, we review these studies presenting a comprehensive view of the B chromosomes in the P. scabripinnis complex and a new hypothesis regarding the role of the B chromosome in the speciation process