Skin reactivity to thimerosal and phenol-preserved Montenegro antigen in Brazil

A randomized double-blind trial was performed to determine the frequency of positive reactions to the Montenegro antigen (leishmanin) preserved in thimerosal (Merthiolate) 1:10,000 or phenol 0.4%. The respective products were tested separately in 400 young healthy individuals from a non-endemic area for Leishmaniases. Each volunteer received one of the following reagents: merthiolated antigen, phenolated antigen, merthiolated saline, or phenolated saline. The frequency of positive responses to each reagent after the first application was as follows: 0% (phenolated saline), 9.2% (merthiolated saline), 34.6% (antigen in phenolated saline), and 41.1% (antigen in merthiolated saline). After 1 week, volunteers who had tested positive for merthiolated or phenolated antigen were retested with the respective preservative, while negatives were retested with the preservative they had not received during the first test. In all, 331 volunteers who received merthiolated saline during the study, of whom 41 (12.4%) tested positive. Meanwhile, 326 volunteers who received phenolated saline, 4 (1.2%) tested positive. Positive reactions in each group were similar in relation to gross appearance skin reactions. Considering the high frequency of hypersensitivity to thimerosal in the study population, it is recommended that this compound should be replaced as a preservative of the leishmanin antigen. Almost 30% of positive reactions to Montenegro antigen in what is considered a non-endemic region was surprising and will be the object of future studies.     

Statistical evaluation of alternative models of human evolution

An appropriate model of recent human evolution is not only important to understand our own history, but it is necessary to disentangle the effects of demography and selection on genome diversity. Although most genetic data support the view that our species originated recently in Africa, it is still unclear if it completely replaced former members of the Homo genus, or if some interbreeding occurred during its range expansion. Several scenarios of modern human evolution have been proposed on the basis of molecular and paleontological data, but their likelihood has never been statistically assessed. Using DNA data from 50 nuclear loci sequenced in African, Asian and Native American samples, we show here by extensive simulations that a simple African replacement model with exponential growth has a higher probability (78%) as compared with alternative multiregional evolution or assimilation scenarios. A Bayesian analysis of the data under this best supported model points to an origin of our species approximately 141 thousand years ago (Kya), an exit out-of-Africa approximately 51 Kya, and a recent colonization of the Americas approximately 10.5 Kya. We also find that the African replacement model explains not only the shallow ancestry of mtDNA or Y-chromosomes but also the occurrence of deep lineages at some autosomal loci, which has been formerly interpreted as a sign of interbreeding with Homo erectus.     

Nerve-sparing radical retropubic prostatectomy in patients previously submitted to holmium laser enucleation of the prostate for bladder outlet obstruction due to benign prostatic enlargement

OBJECTIVES: To evaluate the feasibility and safety of nerve-sparing radical retropubic prostatectomy (NSRRP) for localised prostate cancer after holmium laser enucleation of the prostate (HoLEP) for bladder outlet obstruction due to benign prostatic enlargement (BPE). METHODS: Fifteen consecutive patients with prostate cancer following HoLEP underwent NSRRP. They were matched with an equal number of patients who also underwent NSRRP following transurethral resection of the prostate (TURP group) or open prostatectomy (OP group). Patients were preoperatively assessed with validated questionnaires (International Prostate Symptom Score [IPSS] and International Index of Erectile Function-Erectile Function [IIEF-EF]). Intraoperative, perioperative, and follow-up functional data according to validated questionnaires (IPSS, IIEF-EF, International Consultation on Incontinence Questionnaire-Short Form [ICIQ-SF]) were evaluated with analysis of variance and chi2 tests. RESULTS: At diagnosis, the prostate-specific antigen (PSA) level, clinical stage, Gleason sum distributions, body mass index, ICIQ-SF, and IPSS were not significantly different among the groups. IIEF-EF scores was higher in the HoLEP group (p=0.02). Mean operative time was longer in the OP group (p=0.02), but no difference was found in mean blood loss (p=0.5). Final pathology showed no substantial differences among the groups, although a lower positive surgical margin rate was found in the HoLEP group (p=0.04). Mean follow-up was 23.8+/-10.5 mo. The groups showed no statistical differences in urinary continence rate (p=0.6), IPSS (p=0.3), or IIEF-EF (p=0.4). CONCLUSIONS: NSRRP is feasible in prostate cancer patients who previously underwent HoLEP for BPE and provides satisfactory functional outcomes.     

Altered RNome expression in Murine Gastrocnemius Muscle following Exposure to Jararhagin,a Metalloproteinase from Bothrops jararaca Venom

Small RNAs (sRNAs) and microRNAs (miRNAs) are small endogenous noncoding single-stranded RNAs that regulate gene expression in eukaryotes. Experiments in mice and humans have revealed that a typical small RNA can affect the expression of a wide range of genes, implying that small RNAs function as global regulators. Here, we used small RNA deep sequencing to investigate how jararhagin, a metalloproteinase toxin produced from the venom of Bothrops jararaca, affected mmu-miRNAs expression in mice 2 hours (Jar 2hrs) and 24 hours (Jar 24hrs) after injection compared to PBS control. The findings revealed that seven mmu-miRNAs were substantially differentially expressed (p value (p (Corr) cut-off 0.05, fold change ≥ 2) at 2 hrs after jararhagin exposure and that the majority of them were upregulated when compared to PBS. In contrast to these findings, a comparison of Jar 24hrs vs. PBS 24hrs demonstrated that the majority of identified mmu-miRNAs were downregulated. Furthermore, the studies demonstrated that mmu-miRNAs can target the expression of several genes involved in the MAPK signaling pathway. The steady antithetical regulation of mmu-miRNAs may correlate with the expression of genes that trigger apoptosis via MAPK in the early stages, and this effect intensifies with time. The findings expand our understanding of the effects of jararhagin on local tissue lesions at the molecular level.     

Powder 3D Printing of Bone Scaffolds with Uniform and Gradient Pore Sizes Using Cuttlebone-Derived Calcium Phosphate and Glass-Ceramic

The pore geometry of bone scaffolds has a major impact on their cellular response; for this reason, 3D printing is an attractive technology for bone tissue engineering, as it allows for the full control and design of the porosity. Calcium phosphate materials synthesized from natural sources have recently attracted a certain interest because of their similarity to natural bone, and they were found to show better bioactivity than synthetic compounds. Nevertheless, these materials are very challenging to be processed by 3D printing due to technological issues related to their nanometric size. In this work, bone scaffolds with different pore geometries, with a uniform size or with a size gradient, were fabricated by binder jetting 3D printing using a biphasic calcium phosphate (BCP) nanopowder derived from cuttlebones. To do so, the nanopowder was mixed with a glass-ceramic powder with a larger particle size (45–100 µm) in 1:10 weight proportions. Pure AP40mod scaffolds were also printed. The sintered scaffolds were shown to be composed mainly by hydroxyapatite (HA) and wollastonite, with the amount of HA being larger when the nanopowder was added because BCP transforms into HA during sintering at 1150 °C. The addition of bio-derived powder increases the porosity from 60% to 70%, with this indicating that the nanoparticles slow down the glass-ceramic densification. Human mesenchymal stem cells were seeded on the scaffolds to test the bioactivity in vitro. The cells’ number and metabolic activity were analyzed after 3, 5 and 10 days of culturing. The cellular behavior was found to be very similar for samples with different pore geometries and compositions. However, while the cell number was constantly increasing, the metabolic activity on the scaffolds with gradient pores and cuttlebone-derived powder decreased over time, which might be a sign of cell differentiation. Generally, all scaffolds promoted fast cell adhesion and proliferation, which were found to penetrate and colonize the 3D porous structure.