Arsenic transformations and biomarkers in meadow voles (Microtus pennsylvanicus) living on an abandoned gold mine site in Montague, Nova Scotia, Canada

Arsenic is one of the most widely encountered environmental contaminants because of a number of anthropogenic sources; in Canada the main anthropogenic release of arsenic is from mine tailings ponds. The present study is part of a series of studies to measure chemical and biological effects of exposure for meadow voles (Microtus pennsylvanicus) living on arsenic contaminated sites. Two additional objectives were addressed in the present study: the effect of higher arsenic concentrations compared with previous studies, and the comparison of chemical speciation and biological effects. To obtain the higher environmental concentrations, specimens were collected from a former gold mining site in Montague, NS that contains highly elevated concentrations of arsenic in soils and plants. Meadow voles were collected and their tissues were analyzed for total arsenic to measure uptake, and arsenic speciation to examine the chemical effects of the high arsenic exposure. In addition to the arsenic analysis, a biomonitoring study was undertaken to examine the sub-cellular effects in meadow voles resulting from the elevated arsenic exposure. Meadow voles living on the contaminated site had substantially higher concentrations of total arsenic than animals from the background (reference) location. The extractable arsenic in internal tissues was present mainly as monomethylarsonic acid (up to 14% of total arsenic). A statistically significant relationship was observed between the reduction of glutathione in vole livers and the increase in liver arsenic concentrations, and micronucleated monochromatic red blood cells were also significantly elevated in voles from the arsenic contaminated site. This is one of the few field studies where sub-cellular effects were observed, and the first to show a co-existence of such effects with relatively high proportions of monomethylarsonic acid in voles living near mine tailings.     

金刚烷类化合物与库车坳陷克拉2构造凝析油的形成机理研究

借助于色谱和色谱—质谱分析技术,对库车坳陷克拉2构造和牙哈构造带原油中轻烃、链烷烃、多环芳烃、甾萜烷生物标志化合物和金刚烷类化合物进行了系统分析。结果表明：克拉2构造凝析油的轻烃和全烃组成中特别富含芳烃化合物,甾烷、萜烷中明显富含低分子量化合物如三环萜烷系列、孕甾烷和升孕甾烷,这一特征明显不同于牙哈构造带来源相似的原油和凝析油,显示其形成机理的特殊性。此外,克拉2构造凝析油和牙哈构造带原油中普遍存在烷基单金刚烷系列和烷基双金刚烷系列,但只有克拉2构造凝析油中检测出烷基三金刚烷系列。定量结果表明克拉2构造凝析油中金刚烷类化合物的浓度较牙哈构造带原油高约一个数量级,这些特征表明克拉2构造凝析油的成熟度明显高于牙哈构造带原油。依据甲基单金刚烷指数MAI和甲基双金刚烷指数MDI与镜质体反射率RO间的对应关系,发现克拉2构造凝析油对应的RO值约为1.9%,热裂解程度大于97%,属于典型的热裂解原油,这与富含芳烃的特征吻合;而牙哈构造带原油对应的RO值约为1.2%～1.4%,且不同构造单元原油的热裂解程度变化较大,介于20%～80%之间,这与后期高成熟油气侵入程度有关。     

塔里木盆地塔河油田原油地球化学特征的化学计量学分析及应用

塔里木盆地塔河油田由于存在多期次原油充注导致其成因至今无法得到很好地解释。应用地球化学手段对塔河油田原油地球化学特征进行综合研究,结果显示：塔河油田奥陶系原油沉积于海相沉积环境,处于成熟—过成熟阶段,正构烷烃分布较完整、具有UCM鼓包、普遍存在25?降藿烷、伽马蜡烷含量低,C₂₉藿烷丰度高、规则甾烷呈现C₂₉>C₂₇>C₂₈分布、规则甾烷αββ构型丰度高于ααα构型等特征,表明塔河油田原油遭受过较强程度的微生物降解作用,存在至少2个期次的原油充注。利用主成分分析（PCA）和层序聚类分析（HCA）方法对原油生物标志化合物指标进行分析,将塔河油田原油分为3类：I类原油具有三环萜烷/五环萜烷、Ts/17αC₃₀藿烷、重排甾烷/规则甾烷、C₃₁/C₃₂藿烷、C₂₉/C₃₀藿烷、C₂₄/C₂₃三环萜烷、C₂₀₊₁₉/C₂₃₊₂₄三环萜烷、Ts/Tm高,Ph/nC₁₈低,正构烷烃分布完整,呈现出多期充注特征,但主要表现出早期生物降解原油的特征,早期生物降解原油的贡献高于后期充注正常原油的贡献;II类原油的nC₂₁^-/nC₂₂⁺值最低,部分样品正构烷烃缺失,UCM鼓包明显,主要代表早期经历过强烈微生物降解的原油; III类原油nC₂₁^-/nC₂₂⁺、αβC₃₁?22S/（22S+22R）、C₂₄四环/（C₂₄四环+C₂₆三环）值最高,正构烷烃受热成熟度的影响最大,高碳数正构烷烃大量热裂解导致低碳数正构烷烃相对富集,代表混合原油但正常原油的贡献较大。     

Oil-source rock correlations of Jurassic and Cretaceous oils in the West Khalda area,North Western Desert,Egypt

Oil-source rock correlations are used in this study in order to achieve their relationship, depositional environments, and diagenetic processes in the source rocks. For this purpose many parameters are used, e.g., gross composition of oil and source rock extracts, and biomarker analyses. Ten representative oil samples and seven source rock hydrocarbon extracts were analyzed using relative geochemical analyses, and gas chromatography-mass spectrometry. The results revealed a genetic close relation between them and supported the indigenous mixed source of Alam El Bueib oil, which related to different sources, including Khatatba, Alam El Bueib, and Bahariya formations. Accordingly, Alam El Bueib formation can be considered as an important source for petroleum generation in that area.     

Grand rounds in proteomics at the FDA white oak, silver spring, MD, USA, april 3, 2007

The application of proteomics in drug development could be a major source of novel biomarkers to improve the efficacy and safety of new drugs. Training of US Food and Drug Administration (FDA) reviewers on current applications of proteomics is important for the future review of proteomic data. A Grand Rounds in Proteomics was held on April 3, 2007 at the FDA in White Oak, Silver Spring, MD, USA. The goal of this activity was to contribute to reviewer training as well as to generate discussions regarding the readiness of proteomic platforms in drug development, similar in scope to applications in genomics and metabolomics. Several speakers from industry and academia presented data on proteomic applications in drug development (meeting agenda available in the Supporting Information). An additional goal of this meeting was to encourage proteomic data submissions within the Voluntary eXploratory Data Submissions (VXDS) at the FDA. VXDS meetings represent key venues for exchange between the FDA and sponsors of scientific and clinical data on exploratory biomarkers. The FDA has received a limited number of VXDS submissions containing proteomic data. This meeting was an opportunity to identify possible areas in proteomics where future VXDS submissions may be received. Voluntary submissions have been transformed into regulatory submissions in genomics, and a similar path may also be followed by proteomic data in the future. Proteomic biomarkers may also be suitable for submission to the Pilot Process for Biomarker Qualification at the FDA.     

Diving into the rat plasma proteome to get to the bottom of decompression sickness

Decompression sickness (DCS) is the collective term for an array of signs and symptoms triggered by ambient pressure reduction. It is of particular concern to divers as they decompress on ascend from depth to sea surface, but despite a long history of studies the determinants of DCS risk are incompletely understood and there are no validated biomarkers. In this issue of Proteomics Clinical Applications, Lautridou et al. [8] report on their search for DCS biomarkers in rats exposed to simulated diving. By comparing the plasma proteomes from animals showing neurological symptoms to those emerging from dives unaffected, they identified several high‐abundance proteins not previously associated with DCS. The most significant finding was a near depletion of thyroxine‐ and vitamin A transporter transthyretin in symptomatic rats. In addition to their potential role as diagnostic biomarkers, the proteins identified in Lautridou's study may offer new pieces in the yet incomplete puzzle of DCS etiology.     

Accumulation and effects of metals in caged carp and resident roach along a metal pollution gradient

Metal accumulation and effects on plasma Ca(2+), alanine transaminase (ALT) and fish condition factor were examined in caged carp (Cyprinus carpio) and resident roach (Rutilus rutilus) at four locations along the Grote Nete River system (Belgium). Cadmium and zinc accumulation were found in carp and roach, with highest concentrations at the most contaminated site (dissolved Cd: 1.82 microg/l, Zn: 967 microg/l). On the tissue level, highest cadmium concentrations were measured in kidneys of carp and roach, followed by gills, intestine and liver, while low concentrations were observed in carcass and muscle. For zinc, a similar pattern was observed (intestine>kidney>gills>liver>carcass>muscle). Comparison between species showed higher cadmium concentrations in feral roach, while zinc levels were lower, owing to the high zinc concentrations in control carp. Furthermore, comparison of metal concentrations between two sampling periods (2005 and 2000-2001) revealed a drastic decrease in cadmium concentration in gills, liver and muscle of roach, similar to the reduction in waterborne cadmium concentrations, while differences for zinc were much less pronounced. In addition to metal accumulation, increased metallothionein concentrations (approximately 2x) were found in carp and roach, while no metal-related effects were found on ALT, Ca(2+)or condition factor. However, negative effects on fish community structure, as assessed by the index of biotic integrity (IBI), were found along the pollution gradient and indicated long-term adverse effects of metal pollution.     

Urinary extracellular vesicles for biomarker source to monitor polycystic kidney disease

Extracellular vesicles (EVs) are bilayered lipid vesicles, 50–1000 nm in diameter and secreted by most types of cells. They contain many proteins, mRNAs, miRNAs, and lipids that reflect the pathophysiological state of the cells they originate from, and are therefore considered to be a rich source of potential biomarkers. In this issue (Pocsfalvi, G. et al., Proteomics Clin. Appl. 2015, 9, 552–567), Pocsfalvi et al. conducted pioneering investigations to determine whether changes in the protein content of EVs occur during progression of autosomal dominant polycystic kidney disease (ADPKD), a common genetic disorder that predominantly affects the kidneys. Most significantly, iTRAQ-based quantitative proteomics showed that cytoskeleton-regulating and Ca²⁺-binding proteins are differentially expressed in urinary EVs of ADPKD patients. Impressively, these proteins are involved in biological processes that are closely related to the pathogenic state of tubular epithelial cells in ADPKD, demonstrating the possibility to monitor the status of patients using urinary EVs.