Ewing Sarcoma: influence of TP53 Arg72Pro and MDM2 T309G SNPs

The Ewing Sarcoma is an important tumor of bone and soft tissue. The SNPs Arg72Pro of TP53 and T309G of MDM2 have been associated with many cancer types and have been differently distributed among populations worldwide. Based on a case–control design, this study aimed to assess the role of these SNPs in 24 Ewing Sarcoma patients, compared to 91 control individuals. DNA samples were extracted from blood and genotyped for both SNPs by PCR–RFLP and confirmed by DNA sequencing. The results showed an association between the G allele of the T309G and Ewing Sarcoma (P = 0.02). Comparing to the TT carriers, the risk of G allele carriers was 3.35 (95 % CI = 1.22–9.21) with P = 0.02. At the genotypic level, an association of the TT genotype with the control group (P = 0.03) was found. Comparing to the TT genotype, the risk of TG and GG was 2.97 (95 % CI = 1.03–8.58) with P = 0.04 and 5.00 (95 % CI = 1.23–20.34) with P = 0.02, respectively. No associations regarding the Arg72Pro SNP were found. Considering that the T309G has been associated with several types of cancer, including sarcomas, our results indicate that this SNP may also be important to Ewing Sarcoma predisposition.     

Mercury Concentration in Breast Milk and Infant Exposure Assessment During the First 90 Days of Lactation in a Midwestern Region of Brazil

Breast milk samples collected from 18 nursing mothers between the 15th and 90th day of lactation were digested in nitric acid in a microwave, and total mercury (THg) levels were quantified by atomic fluorescence spectrometry. Participants responded to a 24-h dietary recall questionnaire on the 74th and 76th day of lactation and to a Food Frequency Questionnaire querying the frequency of fish intake over the last 90 days. Usual intake was estimated using the PC-SIDE software package. A meal of fish was offered on the 75th day of lactation. Mothers’ individual mean THg levels ranged from <0.76 to 22.7 ng/mL during the period, and the mean level for all samples (n?=?142) was 6.47?±6.04 ng/mL. The multilevel mixed linear model used showed high heterogeneity of the mercury levels among the mothers, and THg levels did not change significantly over the period under study. However, a significant increase in THg levels was observed after the intervention with the fish meal. Exposure increased for most infants on the 90th day of lactation, with intakes exceeding the THg provisional tolerable weekly intake (PTWI) at least once during the period for 77.8 % of samples. Mothers consumed mostly food from the fat and grain groups, and a significant correlation was detected between consumption of food of these groups and breast milk THg levels (p?=?0.006 and 0.007). A significant correlation was also found between vegetable consumption and carbohydrate intake and THg levels in the samples (p?=?0.015 and 0.045, respectively). No correlation was found between mothers’ daily fish consumption frequency and THg levels. Although this study showed that mercury intake by infants during lactation may exceed the toxicologically safe exposure level (PTWI), we nevertheless believe that the benefits of lactation for both the mother and the infant outweigh the eventual risks that this exposure may represent.     

Molecular targets underlying SUMO‐mediated neuroprotection in brain ischemia

SUMOylation (small ubiquitin‐like modifier conjugation) is an important post‐translational modification which is becoming increasingly implicated in the altered protein dynamics associated with brain ischemia. The function of SUMOylation in cells undergoing ischemic stress and the identity of small ubiquitin‐like modifier (SUMO) targets remain in most cases unknown. However, the emerging consensus is that SUMOylation of certain proteins might be part of an endogenous neuroprotective response. This review brings together the current understanding of the underlying mechanisms and downstream effects of SUMOylation in brain ischemia, including processes such as autophagy, mitophagy and oxidative stress. We focus on recent advances and controversies regarding key central nervous system proteins, including those associated with the nucleus, cytoplasm and plasma membrane, such as glucose transporters (GLUT1, GLUT4), excitatory amino acid transporter 2 glutamate transporters, K⁺ channels (K2P1, K_v1.5, K_v2.1), GluK2 kainate receptors, mGluR8 glutamate receptors and CB1 cannabinoid receptors, which are reported to be SUMO‐modified. A discussion of the roles of these molecular targets for SUMOylation could play following an ischemic event, particularly with respect to their potential neuroprotective impact in brain ischemia, is proposed.     

Follicular 17β-estradiol and progesterone concentrations and degree of cumulus cell expansion as predictors of in vivo-matured oocyte developmental competence in superstimulated heifers

The quality of an oocyte is crucial for successful generation of offspring, but few selection parameters have been identified that reliably predict oocyte developmental competence. The objective of the present study was to determine whether the developmental competence of in vivo-matured oocytes derived from superstimulated heifers could be predicted by 17β-estradiol and progesterone concentrations in follicular fluid, degree of cumulus cell expansion, and follicular diameter. Cumulus oocyte complexes were individually collected from follicles ≥8 mm 22 hours after an induced LH peak and individually fertilized and cultured in vitro. Only oocytes that originated from follicles with 17β-estradiol ≤0.25 μM and progesterone ≥0.26 μM developed into blastocysts. When a combination of these cutoff values was evaluated as a predictor of oocyte competence, the sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 75%, 49%, and 100%, respectively. Hormone concentrations in follicular fluid were also associated with the degree of cumulus cell expansion and only cumulus oocyte complexes with full expansion developed into blastocysts; sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 71%, 45%, and 100%, respectively, when full expansion was used as the predictive criterion for blastocyst production. Follicular diameter was not a good predictor of oocyte competence. In conclusion, concentrations of 17β-estradiol and progesterone in the preovulatory follicle and the degree of cumulus cell expansion are predictors of blastocyst production in superstimulated heifers and can be used as selection markers for oocyte developmental competency.     

Human-Associated Methicillin-Resistant Staphylococcus aureus from a Subtropical Recreational Marine Beach

Reports of Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) detected in marine environments have occurred since the early 1990s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible sources and to identify the risks to bathers of exposure to these organisms. During 40 days over 17 months, 1,001 water and 36 intertidal sand samples were collected by either bathers or investigators at a subtropical recreational beach. Methicillin-sensitive S. aureus (MSSA) and MRSA were isolated and identified using selective growth media and an organism-specific molecular marker. Antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) type, pulsed-field gel electrophoresis (PFGE) pattern, multi-locus sequence type (MLST), and staphylococcal protein A (spa) type were characterized for all MRSA. S. aureus was isolated from 248 (37 %) bather nearby water samples at a concentration range of <2–780 colony forming units per ml, 102 (31 %) ambient water samples at a concentration range of <2–260 colony forming units per ml, and 9 (25 %) sand samples. Within the sand environment, S. aureus was isolated more often from above the intertidal zone than from intermittently wet or inundated sand. A total of 1334 MSSA were isolated from 37 sampling days and 22 MRSA were isolated from ten sampling days. Seventeen of the 22 MRSA were identified by PFGE as the community-associated MRSA USA300. MRSA isolates were all SCCmec type IVa, encompassed five spa types (t008, t064, t622, t688, and t723), two MLST types (ST8 and ST5), and 21 of 22 isolates carried the genes for Panton–Valentine leukocidin. There was a correlation (r?=?0.45; p?=?0.05) between the daily average number of bathers and S. aureus in the water; however, no association between exposure to S. aureus in these waters and reported illness was found. This report supports the concept that humans are a potential direct source for S. aureus in marine waters.     

Serologic survey of West Nile virus in horses from Central-West,Northeast and Southeast Brazil

Since the emergence of West Nile virus (WNV) in North America in 1999, there have been several reports of WNV activity in Central and South American countries. To detect WNV in Brazil, we performed a serological survey of horses from different regions of Brazil using recombinant peptides from domain III of WNV. Positive samples were validated with the neutralisation test. Our results showed that of 79 ELISA-positive horses, nine expressed WNV-specific neutralising antibodies. Eight of the infected horses were from the state of Mato Grosso do Sul and one was from the state of Paraíba. Our results provide additional evidence for the emergence of WNV in Brazil and for its circulation in multiple regions of the country.     

Cleanup of industrial effluents containing heavy metals: a new opportunity of valorising the biomass produced by brewing industry

Heavy metal pollution is a matter of concern in industrialised countries. Contrary to organic pollutants, heavy metals are not metabolically degraded. This fact has two main consequences: its bioremediation requires another strategy and heavy metals can be indefinitely recycled. Yeast cells of Saccharomyces cerevisiae are produced at high amounts as a by-product of brewing industry constituting a cheap raw material. In the present work, the possibility of valorising this type of biomass in the bioremediation of real industrial effluents containing heavy metals is reviewed. Given the auto-aggregation capacity (flocculation) of brewing yeast cells, a fast and off-cost yeast separation is achieved after the treatment of metal-laden effluent, which reduces the costs associated with the process. This is a critical issue when we are looking for an effective, eco-friendly, and low-cost technology. The possibility of the bioremediation of industrial effluents linked with the selective recovery of metals, in a strategy of simultaneous minimisation of environmental hazard of industrial wastes with financial benefits from reselling or recycling the metals, is discussed.     

Cathepsin L silencing enhances arsenic trioxide mediated in vitro cytotoxicity and apoptosis in glioblastoma U87MG spheroids

Despite improved treatment options, glioblastoma multiforme (GBM) remains the most aggressive brain tumour with the shortest post-diagnostic survival. Arsenite (As₂O₃) is already being used in the treatment of acute promyelocytic leukaemia (APL), yet its effects on GBM have not been evaluated in detail. In U87MG cell monolayers, we have previously shown that arsenite cytotoxicity significantly increases upon transient inhibition of lysosomal protease Cathepsin L (CatL). As multicellular spheroids more closely represent in vivo tumours, we aimed to evaluate the impact of permanent CatL silencing on arsenite treatment in U87MG spheroids. CatL was stably silenced using shRNA expression plasmid packed lentiviruses. By using metabolic- and cell viability assays, we demonstrated that long-term CatL silencing significantly increased arsenite cytotoxicity in U87MG spheroids. Silenced CatL also increased arsenite-mediated apoptosis in spheroids via elevated p53 expression, Bax/Bcl2 ratio and caspase 3/7 activity, though with lower efficacy than in monolayers. Arsenite cytotoxicity was enhanced by lower CatL activity, since similar cytotoxicity increase was also observed using the novel CatL inhibitor AT094. The results have significant translational impact, since stable CatL silencing would enable the application of lower systemic doses of arsenite to achieve the desired cytotoxic effects on GBMs in vivo.     

The first case of fatal pneumonia caused by Panton–Valentine leukocidin-producing Staphylococcus aureus in an infant in the Czech Republic

Panton–Valentine leukocidin-producing strains of Staphylococcus aureus can cause severe skin and soft tissue infections and necrotizing pneumonia with a high mortality rate. This is a report on the first case of fatal pneumonia with mediastinitis in an infant in the Czech Republic. The causative agent was a methicillin-susceptible S. aureus strain with pronounced production of the PVL toxin and hyperproduction of enterotoxin A.