Caracterização e avaliação da influência das propriedades físico-químicas sobre a incidência de Staphylococcus aureus em hambúrguer de carne bovina produzido em um frigorífico localizado no município de Campo Grande/MS

Bactérias da espécie Staphylococcus aureus são um importante veículo de Doenças Transmitidas por Alimentos (DTAs). Este micro-organismo é amplamente encontrado em alimentos à base de carne bovina, como hambúrgueres. Neste contexto, o presente estudo tem como objetivo estimar a influência dos teores de cinza, proteína, umidade, gordura, cálcio e carboidratos no desenvolvimento de Staphylococcus aureus em hambúrguer de carne bovina. Utilizou-se uma amostragem de 69 lotes de hambúrgueres de carne bovina produzidos em indústria de alimentos localizada em Campo Grande, MS, Brasil. Os resultados obtidos mostraram que os parâmetros físico-químicos avaliados não apresentam correlação com o crescimento de S. aureus em hambúrguer de carne bovina. Vê-se como importante a elaboração de outros estudos com o objetivo de determinar os fatores que influenciam o crescimento desta bactéria em produtos cárneos

The Added Complications of Climate Change: Understanding and Managing Biodiversity, Ecosystems, and Ecosystem Services Under Multiple Stressors.

Ecosystems around the world are already threatened by land-use and land-cover change, extraction of natural resources, biological disturbances, and pollution. These environmental stressors have been the primary source of ecosystem degradation to date, and climate change is now exacerbating some of their effects. Ecosystems already under stress are likely to have more rapid and acute reactions to climate change; it is therefore useful to understand how multiple stresses will interact, especially as the magnitude of climate change increases. Understanding these interactions could be critically important in the design of climate adaptation strategies, especially because actions taken by other sectors (eg energy, agriculture, transportation) to address climate change may create new ecosystem stresses

Preparing for and managing change: Climate adaptation for biodiversity and ecosystems

The emerging field of climate-change adaptation has experienced a dramatic increase in attention as the impacts of climate change on biodiversity and ecosystems have become more evident. Preparing for and addressing these changes are now prominent themes in conservation and natural resource policy and practice. Adaptation increasingly is viewed as a way of managing change, rather than just maintaining existing conditions. There is also increasing recognition of the need not only to adjust management strategies in light of climate shifts, but to reassess and, as needed, modify underlying conservation goals. Major advances in the development of climate-adaptation principles, strategies, and planning processes have occurred over the past few years, although implementation of adaptation plans continues to lag. With ecosystems expected to undergo continuing climate-mediated changes for years to come, adaptation can best be thought of as an ongoing process, rather than as a fixed endpoint. © The Ecological Society of America

Interpretation of TOMS observations of tropical tropospheric ozone with a global model and in-situ observations

We interpret the distribution of tropical tropospheric ozone columns (TTOCs) from the Total Ozone Mapping Spectrometer (TOMS) by using a global three-dimensional model of tropospheric chemistry (GEOS-CHEM) and additional information from in situ observations. The GEOS-CHEM TTOCs capture 44% of the variance of monthly mean TOMS TTOCs from the convective cloud differential method (CCD) with no global bias. Major discrepancies are found over northern Africa and south Asia where the TOMS TTOCs do not capture the seasonal enhancements from biomass burning found in the model and in aircraft observations. A characteristic feature of these northern tropical enhancements, in contrast to southern tropical enhancements, is that they are driven by the lower troposphere where the sensitivity of TOMS is poor due to Rayleigh scattering. We develop an efficiency correction to the TOMS retrieval algorithm that accounts for the variability of ozone in the lower troposphere. This efficiency correction increases TTOCs over biomass burning regions by 3–5 Dobson units (DU) and decreases them by 2–5 DU over oceanic regions, improving the agreement between CCD TTOCs and in situ observations. Applying the correction to CCD TTOCs reduces by ∼5 DU the magnitude of the “tropical Atlantic paradox” [Thompson et al., 2000], i.e. the presence of a TTOC enhancement over the southern tropical Atlantic during the northern African biomass burning season in December–February. We reproduce the remainder of the paradox in the model and explain it by the combination of upper tropospheric ozone production from lightning NOx, persistent subsidence over the southern tropical Atlantic as part of the Walker circulation, and cross-equatorial transport of upper tropospheric ozone from northern midlatitudes in the African “westerly duct.” These processes in the model can also account for the observed 13–17 DU persistent wave-1 pattern in TTOCs with a maximum over the tropical Atlantic and a minimum over the tropical Pacific during all seasons. The photochemical effects of mineral dust have only a minor role on the modeled distribution of TTOCs, including over northern Africa, due to multiple competing effects. The photochemical effects of mineral dust globally decrease annual mean OH concentrations by 9%. A global lightning NOx source of 6 Tg N yr−1 in the model produces a simulation that is most consistent with TOMS and in situ observations

On the relative role of convection, chemistry, and transport over the South Pacific Convergence Zone during PEM-Tropics B: A case study

A mesoscale 3D model (Meso‐NH) is used to assess the relative importance of convection (transport and scavenging), chemistry, and advection in the vertical redistribution of HOx and their precursors in the upper tropical troposphere. The study is focused on marine deep convection over the South Pacific Convergence Zone (SPCZ) during the PEM‐Tropics B Flight 10 aircraft mission. The model reproduces well the HOx mixing ratios. Vertical variations and the contrast between north and south of the SPCZ for O3 are captured. Convection uplifted O3‐poor air at higher altitude, creating a minimum in the 9–12 km region, in both modeled and observed profiles. The model captured 60% of the observed HCHO variance but fails to reproduce a peak of HCHO mixing ratio at 300 hPa sampled during the northern spirals. Simulated HCHO mixing ratios underestimate observations in the marine boundary layer. In the model, convection is not an efficient process to increase upper tropospheric HCHO, and HCHO is unlikely to serve as a primary source of HOx. Convection plays an important role in the vertical distribution of CH3OOH with efficient vertical transport from the boundary layer to the 10–15 km region where it can act as a primary source of HOx. The SPCZ region acts as a barrier to mixing of tropical and subtropical air at the surface and at high altitudes (above 250 hPa). The 400–270 hPa region over the convergence zone was more permeable, allowing subtropical air masses from the Southern Hemisphere to mix with tropical air from NE of the SPCZ and to be entrained in the SPCZ‐related convection. In this altitude range, exchange of subtropical and tropical air also occurs via airflow, bypassing the convective region SW and proceeding toward the north of the SPCZ

Autocrine Activation of the MET Receptor Tyrosine Kinase in Acute Myeloid Leukemia

Although the treatment of acute myeloid leukemia (AML) has improved significantly, more than half of all patients develop disease that is refractory to intensive chemotherapy. Functional genomics approaches offer a means to discover specific molecules mediating aberrant growth and survival of cancer cells. Thus, using a loss-of-function RNA interference genomic screen, we identified aberrant expression of the hepatocyte growth factor (HGF) as a critical factor in AML pathogenesis. We found HGF expression leading to autocrine activation of its receptor tyrosine kinase, MET, in nearly half of the AML cell lines and clinical samples studied. Genetic depletion of HGF or MET potently inhibited the growth and survival of HGF-expressing AML cells. However, leukemic cells treated with the specific MET kinase inhibitor crizotinib developed resistance due to compensatory upregulation of HGF expression, leading to restoration of MET signaling. In cases of AML where MET is coactivated with other tyrosine kinases, such as fibroblast growth factor receptor 1 (FGFR1), concomitant inhibition of FGFR1 and MET blocked compensatory HGF upregulation, resulting in sustained logarithmic cell kill both in vitro and in xenograft models in vivo. Our results demonstrate widespread dependence of AML cells on autocrine activation of MET, as well as the importance of compensatory upregulation of HGF expression in maintaining leukemogenic signaling by this receptor. We anticipate that these findings will lead to the design of additional strategies to block adaptive cellular responses that drive compensatory ligand expression as an essential component of the targeted inhibition of oncogenic receptors in human cancers

The B-Cell Specific Transcription Factor, Oct-2, Promotes Epstein-Barr Virus Latency by Inhibiting the Viral Immediate-Early Protein, BZLF1

The Epstein-Barr virus (EBV) latent-lytic switch is mediated by the BZLF1 immediate-early protein. EBV is normally latent in memory B cells, but cellular factors which promote viral latency specifically in B cells have not been identified. In this report, we demonstrate that the B-cell specific transcription factor, Oct-2, inhibits the function of the viral immediate-early protein, BZLF1, and prevents lytic viral reactivation. Co-transfected Oct-2 reduces the ability of BZLF1 to activate lytic gene expression in two different latently infected nasopharyngeal carcinoma cell lines. Furthermore, Oct-2 inhibits BZLF1 activation of lytic EBV promoters in reporter gene assays, and attenuates BZLF1 binding to lytic viral promoters in vivo. Oct-2 interacts directly with BZLF1, and this interaction requires the DNA-binding/dimerization domain of BZLF1 and the POU domain of Oct-2. An Oct-2 mutant (Δ262–302) deficient for interaction with BZLF1 is unable to inhibit BZLF1-mediated lytic reactivation. However, an Oct-2 mutant defective for DNA-binding (Q221A) retains the ability to inhibit BZLF1 transcriptional effects and DNA-binding. Importantly, shRNA-mediated knockdown of endogenous Oct-2 expression in several EBV-positive Burkitt lymphoma and lymphoblastoid cell lines increases the level of lytic EBV gene expression, while decreasing EBNA1 expression. Moreover, treatments which induce EBV lytic reactivation, such as anti-IgG cross-linking and chemical inducers, also decrease the level of Oct-2 protein expression at the transcriptional level. We conclude that Oct-2 potentiates establishment of EBV latency in B cells

Identification and Characterization of Peripheral T-Cell Lymphoma-Associated SEREX Antigens

Peripheral T-cell lymphomas (PTCL) are generally less common and pursue a more aggressive clinical course than B-cell lymphomas, with the T-cell phenotype itself being a poor prognostic factor in adult non-Hodgkin lymphoma (NHL). With notable exceptions such as ALK+ anaplastic large cell lymphoma (ALCL, ALK+), the molecular abnormalities in PTCL remain poorly characterised. We had previously identified circulating antibodies to ALK in patients with ALCL, ALK+. Thus, as a strategy to identify potential antigens associated with the pathogenesis of PTCL, not otherwise specified (PTCL, NOS), we screened a testis cDNA library with sera from four PTCL, NOS patients using the SEREX (serological analysis of recombinant cDNA expression libraries) technique. We identified nine PTCL, NOS-associated antigens whose immunological reactivity was further investigated using sera from 52 B- and T-cell lymphoma patients and 17 normal controls. The centrosomal protein CEP250 was specifically recognised by patients sera and showed increased protein expression in cell lines derived from T-cell versus B-cell malignancies. TCEB3, BECN1, and two previously uncharacterised proteins, c14orf93 and ZBTB44, were preferentially recognised by patients' sera. Transcripts for all nine genes were identified in 39 cancer cell lines and the five genes encoding preferentially lymphoma-recognised antigens were widely expressed in normal tissues and mononuclear cell subsets. In summary, this study identifies novel molecules that are immunologically recognised in vivo by patients with PTCL, NOS. Future studies are needed to determine whether these tumor antigens play a role in the pathogenesis of PTCL

Rational Design for Enhanced Acyltransferase Activity in Water Catalyzed by the Pyrobaculum calidifontis VA1 Esterase

Biocatalytic transesterification is commonly carried out employing lipases in anhydrous organic solvents since hydrolases usually prefer hydrolysis over acyl transfer in bulk water. However, some promiscuous acyltransferases can catalyze acylation in an aqueous solution. In this study, a rational design was performed to enhance the acyltransferase selectivity and substrate scope of the Pyrobaculum calidifontis VA1 esterase (PestE). PestE wild type and variants were applied for the acylation of monoterpene alcohols. The mutant PestE_I208A is selective for (–)-menthyl acetate (E-Value = 55). Highly active acyltransferases were designed, allowing for complete conversion of (–)-citronellol to citronellyl acetate. Additionally, carvacrol was acetylated but with lower conversions. To the best of our knowledge, this is the first example of the biocatalytic acylation of a phenolic alcohol in bulk water. In addition, a high citronellol conversion of 92% was achieved with the more environmentally friendly and inexpensive acyl donor ethyl acetate using PestE_N288F as a catalyst. PestE_N288F exhibits good acyl transfer activity in an aqueous medium and low hydrolysis activity at the same time. Thus, our study demonstrates an alternative synthetic strategy for acylation of compounds without organic solvents

Effects of exposure to organic solvents and occupational noise on hearing loss and tinnitus in US adults from 1999 to 2004

There is evidence that organic solvents are ototoxic, and studies suggest there is an interaction between organic solvents and noise on ototoxicity. The purpose of this study was 1) to explore the association between organic solvent exposure and hearing loss or tinnitus and 2) to determine if interaction exists between occupational noise and organic solvent exposure on hearing loss or tinnitus. This study used data from the National Health and Nutrition Examination Survey (NHANES) from 1999-2004 to analyze data on hearing outcomes and organic solvent exposure. The following organic solvents were studied: 1) 1,4-dichlorobenzene, 2) benzene, 3) ethylbenzene, 4) styrene, 5) toluene, 6) o-xylene, and 7) m-/p-xylene. Study participants were excluded if they had bilaterally unsymmetrical hearing loss, missing data on covariates, or detectable blood measurements that exceed the calibrated range of assay. The number of study participants included in this study was 2,513, but the sample size varied by analysis as the available data for each organic solvent and outcome varied. Data from the Occupational Information Network (O*NET) was used to approximate occupational noise exposure in study participants based on their job. Logistic regression was used to determine associations between organic solvent exposure and hearing outcomes (i.e., self-reported hearing loss, audiometrically-assessed hearing loss, self-reported tinnitus, high-frequency hearing loss, and low-frequency hearing loss). The age of study participants ranged from 20-59 years. A majority of study participants had an income equal to or over $20,000 (80.5%) and were non-Hispanic white (49.7%), while a minority of study participants had recently used ototoxic medication (4.3%), were smokers (22.4%), were diabetic (5.0%), or were classified as exposed to non-occupational noise (30.0%). After adjusting for covariates, there was no evidence of an association between hearing loss or tinnitus and organic solvent exposure except for three solvents: higher levels of benzene, ethylbenzene and toluene were associated with high-frequency hearing loss (benzene adjusted odds ratio (OR)=1.43, 95% confidence interval (CI) 1.15- 1.78; ethylbenzene adjusted OR=1.24, 95% CI 1.02-1.50; and toluene adjusted OR=1.27, 95% CI 1.06-1.52). Moreover, the effect estimates for high-and low-frequency hearing loss were higher as compared to audiometrically-assessed hearing loss. Additionally, no evidence of interactions between organic solvent exposure and occupational noise on high-frequency hearing loss was observed. In conclusion, this dissertation found, in a large, diverse population with blood measurements of organic solvents, there was no indication of association between organic solvent exposure and self-reported and audiometrically-assessed hearing loss or self-reported tinnitus, but there was evidence of an association between organic solvents and high-frequency hearing loss