Composição fenólica de ligninas dioxano determinadas pela reação oxidativa com o nitrobenzeno

A correta quantificação da concentração de lignina em plantas forrageiras, pelo método espectrofotométrico, pressupõe a existência de um padrão de referência. Um padrão de referência deve ter composição fenólica semelhante à da lignina da parede celular. O objetivo deste trabalho foi verificar se ligninas extraídas com solução ácida de dioxano para serem utilizadas como padrão de referência, apresentariam variação na composição fenólica da mesma maneira que a lignina da parede celular. Amostras de parede celular de "bromegrass", milho e trevo-vermelho foram submetidas ao método para extração de ligninas com solução ácida de dioxano. A composição fenólica das ligninas foi analisada mediante oxidação alcalina pelo nitrobenzeno com posterior separação dos componentes monoméricos via HPLC. As ligninas extraídas confirmaram a existência de variação na composição fenólica da mesma maneira às ligninas intactas presentes na parede celular e de substancial presença de ácidos cinâmicos nas ligninas de gramíneas. No que diz respeito à composição fenólica, ligninas extraídas com solução ácida de dioxano podem ser consideradas potenciais padrões de referência paras as análises espectrofotométricas.

Espectros de duas formas de lignina obtidos por ressonância magnética nuclear

O conteúdo de lignina pode ser útil na estimativa da digestão da fibra de plantas forrageiras. A determinação quantitativa da lignina pelo método espectrofotométrico pressupõe a existência de um padrão de referência satisfatório. O objetivo deste trabalho foi avaliar, por meio da ressonância magnética nuclear (RMN), duas ligninas, uma extraída com brometo de acetila (LBrAc) e outra com solução ácida de dioxano (LDiox), para utilização como padrão de referência em análises espectrofotométricas. A ressonância de próton acusou altos teores de carboidratos contaminantes nas amostras de LBrAc. Como a cromatografia líquida já havia indicado menor presença de carboidratos contaminantes na LDiox, os espectros por ressonância de carbono, mais rica em detalhes do que a espectroscopia anterior, porém mais demorada, foram realizados somente nas ligninas LDiox. Este espectro revelou picos típicos, comuns à maioria das ligninas. Os achados da RMN foram condizentes com a análise química, a qual identificou que o carboidrato da parede celular que acompanha a LBrAc seria possivelmente a celulose, ao passo que a pequena contaminação da LDiox teria origem nas pentosanas. A LDiox pode ser considerada melhor padrão de referência para as análises espectrofotométricas do que a LBrAc.

PPARβ/δ attenuates palmitate-induced endoplasmic reticulum stress and induces autophagic markers in human cardiac cells.

BACKGROUND: Chronic endoplasmic reticulum (ER) stress contributes to the apoptotic cell death in the myocardium, thereby playing a critical role in the development of cardiomyopathy. ER stress has been reported to be induced after high-fat diet feeding in mice and also after saturated fatty acid treatment in vitro. Therefore, since several studies have shown that peroxisome proliferator-activated receptor (PPAR)β/δ inhibits ER stress, the main goal of this study consisted in investigating whether activation of this nuclear receptor was able to prevent lipid-induced ER stress in cardiac cells. METHODS AND RESULTS: Wild-type and transgenic mice with reduced PPARβ/δ expression were fed a standard diet or a high-fat diet for two months. For in vitro studies, a cardiomyocyte cell line of human origin, AC16, was treated with palmitate and the PPARβ/δ agonist GW501516. Our results demonstrate that palmitate induced ER stress in AC16 cells, a fact which was prevented after PPARβ/δ activation with GW501516. Interestingly, the effect of GW501516 on ER stress occurred in an AMPK-independent manner. The most striking result of this study is that GW501516 treatment also upregulated the protein levels of beclin 1 and LC3II, two well-known markers of autophagy. In accordance with this, feeding on a high-fat diet or suppression of PPARβ/δ in knockout mice induced ER stress in the heart. Moreover, PPARβ/δ knockout mice also displayed a reduction in autophagic markers. CONCLUSION: Our data indicate that PPARβ/δ activation might be useful to prevent the harmful effects of ER stress induced by saturated fatty acids in the heart by inducing autophagy.

TraumaHawk: Improving Treatment for Crash Victims Using Photos and a Smartphone App

Photographic documentation of crashed vehicles at the scene can be used to improve triage of crash victims. A U.S. expert panel developed field triage rules to determine the likelihood of occupants sustaining serious injuries based on vehicle damage that would require transport to a trauma center (Sasser et al., 2011). The use of photographs for assessing vehicle damage and occupant compartment intrusion as it correlates to increased injury severity has been validated (Davidson et al., 2014). Providing trauma staff with crash scene photos remotely could assist them in predicting injuries. This would allow trauma care providers to assess the appropriate transport, as well as develop mental models of treatment options prior to patient arrival at the emergency department (ED). Crash-scene medical response has improved tremendously in the past 20-30 years. This is in part due to the increasing number of paramedics who now have advanced life support (ALS) training that allows independence in the field. However, while this advanced training provides a more streamlined field treatment protocol, it also means that paramedics focused on treating crash victims may not have time to communicate with trauma centers regarding crash injury mechanisms. As a result, trauma centers may not learn about severe trauma patients until just a few minutes before they arrive. The information transmitted by the TraumaHawk app allows interpretation of injury mechanisms from crash scene photos at the trauma center, providing clues about the type and severity of injury. With strategic crash scene photo documentation, trained trauma professionals can assess the severity and patterns of injury based on exterior crush and occupant intrusion. Intrusion increases the force experienced by vehicle occupants, which translates into a higher level of injury severity (Tencer et al., 2005; Assal et al., 2002; Mandell et al., 2010). First responders have the unique opportunity to assess the damaged vehicle at the crash scene, but often the mechanism of injury is limited or not even relayed to ED trauma staff. To integrate photographic and scene information, an app called TraumaHawk was created to capture images of crash vehicles and send them electronically to the trauma center. If efficiently implemented, it provides the potential advantage of increasing lead-time for preparation at the trauma center through the crash scene photos. Ideally, the result is better treatment outcomes for crash victims. The objective of this analysis was to examine if the extra lead-time granted by the TraumaHawk app could improve trauma team activation time over the current conventional communication method.

A high-resolution anatomical atlas of the transcriptome in the mouse embryo.

Ascertaining when and where genes are expressed is of crucial importance to understanding or predicting the physiological role of genes and proteins and how they interact to form the complex networks that underlie organ development and function. It is, therefore, crucial to determine on a genome-wide level, the spatio-temporal gene expression profiles at cellular resolution. This information is provided by colorimetric RNA in situ hybridization that can elucidate expression of genes in their native context and does so at cellular resolution. We generated what is to our knowledge the first genome-wide transcriptome atlas by RNA in situ hybridization of an entire mammalian organism, the developing mouse at embryonic day 14.5. This digital transcriptome atlas, the Eurexpress atlas (http://www.eurexpress.org), consists of a searchable database of annotated images that can be interactively viewed. We generated anatomy-based expression profiles for over 18,000 coding genes and over 400 microRNAs. We identified 1,002 tissue-specific genes that are a source of novel tissue-specific markers for 37 different anatomical structures. The quality and the resolution of the data revealed novel molecular domains for several developing structures, such as the telencephalon, a novel organization for the hypothalamus, and insight on the Wnt network involved in renal epithelial differentiation during kidney development. The digital transcriptome atlas is a powerful resource to determine co-expression of genes, to identify cell populations and lineages, and to identify functional associations between genes relevant to development and disease.

Oral rivaroxaban for symptomatic venous thromboembolism.

BACKGROUND: Rivaroxaban, an oral factor Xa inhibitor, may provide a simple, fixed-dose regimen for treating acute deep-vein thrombosis (DVT) and for continued treatment, without the need for laboratory monitoring. METHODS: We conducted an open-label, randomized, event-driven, noninferiority study that compared oral rivaroxaban alone (15 mg twice daily for 3 weeks, followed by 20 mg once daily) with subcutaneous enoxaparin followed by a vitamin K antagonist (either warfarin or acenocoumarol) for 3, 6, or 12 months in patients with acute, symptomatic DVT. In parallel, we carried out a double-blind, randomized, event-driven superiority study that compared rivaroxaban alone (20 mg once daily) with placebo for an additional 6 or 12 months in patients who had completed 6 to 12 months of treatment for venous thromboembolism. The primary efficacy outcome for both studies was recurrent venous thromboembolism. The principal safety outcome was major bleeding or clinically relevant nonmajor bleeding in the initial-treatment study and major bleeding in the continued-treatment study. RESULTS: The study of rivaroxaban for acute DVT included 3449 patients: 1731 given rivaroxaban and 1718 given enoxaparin plus a vitamin K antagonist. Rivaroxaban had noninferior efficacy with respect to the primary outcome (36 events [2.1%], vs. 51 events with enoxaparin-vitamin K antagonist [3.0%]; hazard ratio, 0.68; 95% confidence interval [CI], 0.44 to 1.04; P<0.001). The principal safety outcome occurred in 8.1% of the patients in each group. In the continued-treatment study, which included 602 patients in the rivaroxaban group and 594 in the placebo group, rivaroxaban had superior efficacy (8 events [1.3%], vs. 42 with placebo [7.1%]; hazard ratio, 0.18; 95% CI, 0.09 to 0.39; P<0.001). Four patients in the rivaroxaban group had nonfatal major bleeding (0.7%), versus none in the placebo group (P=0.11). CONCLUSIONS: Rivaroxaban offers a simple, single-drug approach to the short-term and continued treatment of venous thrombosis that may improve the benefit-to-risk profile of anticoagulation. (Funded by Bayer Schering Pharma and Ortho-McNeil; ClinicalTrials.gov numbers, NCT00440193 and NCT00439725.).

Local effects and global impact in neurotoxicity and neurodegeneration: The Xi"an International Neurotoxicology Conference

'Neurotoxicity and Neurodegeneration: Local Effect and Global Impact' was the theme of the Xi"an International Neurotoxicology Conference (XINC), held in Xi"an, June 2011. The Conference was a joint event of the 13th Biennial Meeting of the International Neurotoxicology Association (INA-13) and the 11th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health (NEUREOH-11) of the Scientific Committee on Neurotoxicology and...

Local effects and global impact in neurotoxicity and neurodegeneration: The Xi"an International Neurotoxicology Conference

'Neurotoxicity and Neurodegeneration: Local Effect and Global Impact' was the theme of the Xi"an International Neurotoxicology Conference (XINC), held in Xi"an, June 2011. The Conference was a joint event of the 13th Biennial Meeting of the International Neurotoxicology Association (INA-13) and the 11th International Symposium on Neurobehavioral Methods and Effects in Occupational and Environmental Health (NEUREOH-11) of the Scientific Committee on Neurotoxicology and...

Associations of baroreflex sensitivity, heart rate variability, and initial orthostatic hypotension with prenatal and recent postnatal methylmercury exposure in the Seychelles Child Development Study at age 19 years.

BACKGROUND: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. METHODS: Subjects in the Seychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects' hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. RESULTS: Prenatal MeHg exposures were similar in boys and girls (6.7±4.3, 6.7±3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2±5.8 vs 7.9±4.3 ng/g, p=0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8±7 ms/mm Hg, PNN50: 24.9±6.8%, rMSSD: 68±22, LF/HF: 0.61±0.28) in both sexes. After standing, 51.4% of subjects had a transient systolic BP drop>40 mm Hg, but only 5.3% reported dizziness or had syncope. Prenatal and recent postnatal MeHg levels, overall, were not associated with BRS, E/I ratio, PNN50, rMSSD, LF/HF ratio, Max30/Min15 ratio, and IOH. CONCLUSIONS: This study provides no support for the hypothesis that prenatal or recent postnatal MeHg exposure from fish consumption is associated with impaired autonomic heart rate control.