同步辐射技术在环境污染监测及生态毒理研究中的应用

随着环境问题的日趋严重,其研究也愈加深入,更多的高新技术也应用到该领域中。同步辐射是电子以接近光速的速度作圆周运动或蛇形运动,在改变运动方向时,沿着运动轨道的切线方向发出的电磁辐射,可在宽广的能量区域中利用高亮度、性能优越的光。本文综述了同步辐射技术在水体、大气和极地环境的污染监测中的作用,同时总结了其在有机化合物、典型重金属元素生态毒性研究中的应用,并进一步展望了该技术在环境领域的应用前景。     

Physiological parameters in ecotoxicology.

1. Regulated physiological parameters are normally maintained at a constant level by regulatory mechanisms. Acute toxic effects develop whenever a pollutant causes a regulated parameter to be displaced beyond tolerated limits, and thus, regulated parameters may be convenient toxicity parameters. The present study indicates that delta mu Na+ across the adductor muscle membrane of Mytilus edulis is a regulated parameter, and that injuries develop whenever this parameter drops below -700 J/mole. 2. Regulatory physiological parameters may display quick and substantial changes when regulatory mechanisms are activated to counteract variations in the regulated parameters. Thus, regulatory parameters may be used as sensitive alarm parameters in environmental monitoring. The present results indicate that the phosphate index [(ATP x P-arginine)/(Pi)2], metabolic rate and strombine may be used as alarm parameters. 3. The combined response of all parameters may provide a pollutant-specific fingerprint in environmental monitoring.     

Applications of affinity chromatography in proteomics

Affinity chromatography is a powerful protein separation method that is based on the specific interaction between immobilized ligands and target proteins. Peptides can also be separated effectively by affinity chromatography through the use of peptide-specific ligands. Both two-dimensional electrophoresis (2-DE)- and non-2-DE-based proteomic approaches benefit from the application of affinity chromatography. Before protein separation by 2-DE, affinity separation is used primarily for preconcentration and pretreatment of samples. Those applications entail the removal of one protein or a class of proteins that might interfere with 2-DE resolution, the concentration of low-abundance proteins to enable them to be visualized in the gel, and the classification of total protein into two or more groups for further separation by gel electrophoresis. Non-2-DE-based approaches have extensively employed affinity chromatography to reduce the complexity of protein and peptide mixtures. Prior to mass spectrometry (MS), preconcentration and capture of specific proteins or peptides to enhance sensitivity can be accomplished by using affinity adsorption. Affinity purification of protein complexes followed by identification of proteins by MS serves as a powerful tool for generating a map of protein-protein interactions and cellular locations of complexes. Affinity chromatography of peptide mixtures, coupled with mass spectrometry, provides a tool for the study of protein posttranslational modification (PTM) sites and quantitative proteomics. Quantitation of proteomes is possible via the use of isotope-coded affinity tags and isolation of proteolytic peptides by affinity chromatography. An emerging area of proteomics technology development is miniaturization. Affinity chromatography is becoming more widely used for exploring PTM and protein-protein interactions, especially with a view toward developing new general tag systems and strategies of chemical derivatization on peptides for affinity selection. More applications of affinity-based purification can be expected, including increasing the resolution in 2-DE, improving the sensitivity of MS quantification, and incorporating purification as part of multidimensional liquid chromatography experiments.     

Applications of proteomics in pharmaceutical research and development

The significance of proteomics in the pharmaceutical industry has increased since overcoming initial difficulties. This review discusses recent proteomics publications from pharmaceutical companies to identify new trends in proteomics applications to research and development. Applications of proteomics such as chemical proteomics, protein expression profiling, targeted protein quantitation, analysis of protein-protein interactions and post-translational modification are widely used by various sections of the industry. Technological advancements in proteomics will further accelerate pharmaceutical research and development.     

Transcriptomics applied to obesity and caloric restriction

Caloric restriction still remains the most efficient way to promote weight loss. Deciphering the molecular basis of adaptation to energy restriction is critical for the tailoring of new therapeutic strategies. This review focuses on the recent input of gene profiling on adipose tissue in obesity pathogenesis and on the new insights on adaptations occurring during very low caloric diet (VLCD) in humans. Hypocaloric diets improve a wide range of metabolic parameters including lipolytic efficiency, insulin sensitivity, and inflammatory profile. In the subcutaneous white adipose tissue (scWAT) the VLCD induced a decrease in the mRNA levels for the antilipolytic alpha2-adrenergic receptor associated with changes in catecholamine-induced adipocyte lipolytic capacity. The improvement in insulin sensitivity was not associated with a change in subcutaneous adipose tissue adiponectin gene expression or in its plasma level, suggesting that adiponectin is not involved in the regulation of VLCD-induced improvement of insulin sensitivity and that there is a small contribution of subcutaneous adipose tissue to plasma adiponectin levels. Pangenomic microarray studies in human scWAT revealed that a panel of inflammatory markers and acute phase reactants were over expressed in obese compared to lean subjects. Caloric restriction improved the inflammatory profile of obese subjects through a decrease of pro-inflammatory factors and an increase of anti-inflammatory molecules. These genes were mostly expressed in the stroma vascular fraction of the adipose tissue. Specific cell-type isolation and immunohistochemistry demonstrated that monocyte/macrophage lineage cells were responsible for the expression of both mRNA and protein inflammatory markers. The acute phase proteins serum amyloid A was highly expressed in mature adipocytes from obese subjects. Caloric restriction decreased both serum amyloid mRNA and circulating levels. Obesity now clearly appears as chronic low-grade inflammation state. Modulation of the inflammatory pathways may represent new therapeutic targets for the treatment of obesity-related complications.     

Applications of proteomics in hepatic diseases research

Proteomics has become an important part in the leading research area and been widely used in the disease-associated study. In hepatic research field, proteomics could be applied in study of hepatic diseases including liver cancer, cirrhosis and hepatotoxicities, etc. Significant proteins could be identified as biomarkers, drug targets and clues for pathogenesis illumination.     

Applications of proteomics in hepatic diseases research

Since the completion of human genome draft in the process of Human Genome Project (HGP), life science has entered the post-genome era in the early 21st century. Proteomics has become an important part in the leading research area and been applied in many fields of life science such as the occurrence and de-velopment of tumor, cell differentiation and embryo-genesis, mechanisms of gene regulation, mechanisms and therapy of major diseases, pharmacy, relationship between environment and health …     

Applications of urinary proteomics in biomarker discovery

Urine is an important source of biomarkers. This article reviews current advances, major challenges, and future prospects in the field of urinary proteomics. Because the practical clinical problem is to distinguish diseases with similar symptoms, merely comparing samples from patients of a particular disease to those of healthy individuals is inadequate for finding biomarkers with sufficient diagnostic power. In addition, the variation of expression levels of urinary proteins among healthy individuals and individuals under different physiological conditions adds to the difficulty in identifying biomarkers. We propose that establishing the natural variation in urinary protein expression among a healthy population can serve as a reference to help identify protein abundance changes that are caused by disease, not by individual variations or physiological changes. We also discuss that comparing protein expression levels between urine and plasma may reveal the physiological function of the kidney and that may facilitate biomarker discovery. Finally, we propose that establishing a data-sharing platform for data collection and integrating results from all urinary biomarker studies will help promote the development of urinary proteomics.     

Applications of monolithic silica capillary columns in proteomics

The use and applicability of silica based capillary monolithic reversed-phase columns in proteomic analysis has been evaluated by liquid chromatography-mass spectrometry (LC-MS). Chromatographic performance of the monolithic capillaries was evaluated with a tryptic digest of cytochrome C showing very good resolution and reproducibility in addition to the known advantages of a low pressure drop over a time period of 6 months. Monoliths were subsequently tested for their suitability to separate proteins and peptides from samples typically encountered in proteomic research such as in-gel digested tryptic peptide mixtures or fractions of proteolytically digested human serum. The monolithic capillaries also proved useful in the analysis of phospholipid species in bronchoalveolar lavage fluid. Compared to particle-filled conventional capillary columns, rapid and highly efficient separation of peptides and proteins was achieved using these bimodal pore size distribution columns, and good quality collision induced dissociation (CID) mass spectra were obtained on an ion trap mass spectrometer. These novel monolithic separation media are thus a promising addition to the methodological toolbox of proteomics research.     

Molecular biologist's guide to proteomics.

The emergence of proteomics, the large-scale analysis of proteins, has been inspired by the realization that the final product of a gene is inherently more complex and closer to function than the gene itself. Shortfalls in the ability of bioinformatics to predict both the existence and function of genes have also illustrated the need for protein analysis. Moreover, only through the study of proteins can posttranslational modifications be determined, which can profoundly affect protein function. Proteomics has been enabled by the accumulation of both DNA and protein sequence databases, improvements in mass spectrometry, and the development of computer algorithms for database searching. In this review, we describe why proteomics is important, how it is conducted, and how it can be applied to complement other existing technologies. We conclude that currently, the most practical application of proteomics is the analysis of target proteins as opposed to entire proteomes. This type of proteomics, referred to as functional proteomics, is always driven by a specific biological question. In this way, protein identification and characterization has a meaningful outcome. We discuss some of the advantages of a functional proteomics approach and provide examples of how different methodologies can be utilized to address a wide variety of biological problems.     

Applications of MALDI-TOF mass spectrometry in clinical proteomics

Introduction: The development of precision medicine requires advanced technologies to address the multifactorial disease stratification and to support personalized treatments. Among omics techniques, proteomics based on Mass Spectrometry (MS) is becoming increasingly relevant in clinical practice allowing a phenotypic characterization of the dynamic functional status of the organism. From this perspective, Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) MS is a suitable platform for providing a high-throughput support to clinics.

Areas covered: This review aims to provide an updated overview of MALDI-TOF MS applications in clinical proteomics. The most relevant features of this analysis have been discussed, highlighting both pre-analytical and analytical factors that are crucial in proteomics studies. Particular emphasis is placed on biofluids proteomics for biomarkers discovery and on recent progresses in clinical microbiology, drug monitoring, and minimal residual disease (MRD).

Expert commentary: Despite some analytical limitations, the latest technological advances together with the easiness of use, the low time and low cost consuming and the high throughput are making MALDI-TOF MS instruments very attractive for the clinical practice. These features offer a significant potential for the routine of the clinical laboratory and ultimately for personalized medicine.