Molecularly imprinted polymers: synthesis and characterisation

This short review aims to present, in clear English, a summary of the principal synthetic considerations pertaining to good practice in the polymerisation aspects of molecular imprinting, and is primarily aimed at researchers familiar with molecular imprinting methods but with little or no prior experience in polymer synthesis. It is our hope that this will facilitate researchers to plan their own syntheses of molecular imprints in a more logical and structured fashion, and to begin to appreciate the limitations of the present synthetic approaches in this molecularly complex area, as well as the scope for rationally designing improved imprinted materials in the future.     

Molecularly imprinted polymers in pseudoimmunoassay

Immunoassays are a class of analytical techniques based on the selective affinity of a biological antibody for its antigen. Competitive binding assays, of which the radioimmunoassay (RIA) was the first example, are based on the competition between analyte and a labelled probe for a limited number of binding sites. Molecularly imprinted polymers (MIPs) have been shown to be suitable replacements for biological antibodies in such techniques. Molecularly imprinted sorbent assays (MIAs) similar to RIA have been developed for a range of analytes of clinical and environmental interest. Limits of detection and selectivities of such assays are often similar to those using biological antibodies. Some assays have been used for measurements directly in biological fluids. The field is reviewed and it is shown that some perceived disadvantages of MIPs do not hinder their application in competitive binding assays: many MIAs have been demonstrated in aqueous solvents, and it has been shown that the quantity of template required to prepare imprinted polymers can be drastically reduced, and that binding site heterogeneity is not a problem as long as the sites which bind the probe most strongly are selective. Finally, recent developments including assays in microtitre plates, the use of enzyme-labelled probes, flow-injection assays and a scintillation proximity MIA are discussed.     

Molecularly imprinted polymer formats for capillary electrochromatography

The research aimed towards the adaptation of molecularly imprinted polymers (MIPs) to the capillary format and the use of these highly selective matrices for capillary electrochromatography (CEC) is reviewed in this article. The MIP is prepared by incorporation of a template molecule into a polymerization protocol. After polymerization and extraction of the template from the resulting polymer a highly selective material with recognition cavities complementary to the template in size, shape and chemical functionality is obtained. MIPs have been used as recognition elements in several different analytical techniques. In combination with CEC a novel separation system with a unique selectivity towards a predetermined target (the template) is achieved. The merge of molecular imprinting technology (MIT) and CEC have introduced several interesting polymer formats, due to the adaptation of the MIP to the miniaturized capillary format. The polymer formats can be classified according to their preparation protocols and appearance into three conceptually different categories, i.e. the monolith, the coating and the nanoparticles. The preparation protocols, characteristics and applications of these formats will be discussed.     

Peptidomics

Peptides occur in the whole animal kingdom, from the least evolved phyla with a very simple nervous system (coelenterates) to the highest vertebrates and are involved in most, if not all, physiological processes in animals. Knowing the amino acid sequence of peptide hormones or neurotransmitters is important since this allows for synthesis of large quantities of peptides to perform further functional analysis. Immunocytochemistry, radioimmunoassays (RIA), enzyme-linked immunosorbant assays (ELISA) and mass spectrometry can then provide information on the temporal and spatial distribution and quantification of the (neuro)peptide. Ever since the 1970s, a wealth of peptides has been discovered and investigated and this flow seems to be far from over. This is partially due to the use of new approaches mainly based on chromatographical purifications as well as molecular biological techniques. Surprisingly, peptides have so far been neglected in most proteomic studies. The finalization of the genome projects has opened new opportunities for rapid identification and functional analysis of (neuro)peptides as well. In analogy with the proteomics technology, where all proteins expressed in a cell or tissue are analyzed, the peptidomic approach aims at the simultaneous visualization and identification of the whole peptidome of a cell or tissue, i.e. all expressed peptides with their post-translational modifications (PTMs). This technology provides us with a fast and efficient tool to analyze the peptides from any tissue. This paper reviews the approaches that have been used so far to achieve this.     

Proteomics of Staphylococcus aureus--current state and future challenges

This paper presents a short review of the proteome of Staphylococcus aureus, a gram-positive human pathogen of increasing importance for human health as a result of the increasing antibiotic resistance. A proteome reference map is shown which can be used for future studies and is followed by a demonstration of how proteomics could be applied to obtain new information on S. aureus physiology. The proteomic approach can provide new data on the regulation of metabolism as well as of the stress or starvation responses. Proteomic signatures encompassing specific stress or starvation proteins are excellent tools to predict the physiological state of a cell population. Furthermore proteomics is very useful for analysing the size and function of known and unknown regulons and will open a new dimension in the comprehensive understanding of regulatory networks in pathogenicity. Finally, some fields of application of S. aureus proteomics are discussed, including proteomics and strain evaluation, the role of proteomics for analysis of antibiotic resistance or for discovering new targets and diagnostics tools. The review also shows that the post-genome era of S. aureus which began in 2001 with the publication of the genome sequence is still in a preliminary stage, however, the consequent application of proteomics in combination with DNA array techniques and supported by bioinformatics will provide a comprehensive picture on cell physiology and pathogenicity in the near future.     

胶原蛋白研发的最新进展

胶原蛋白是一组由多糖蛋白分子组成的大家族,是结缔组织的主要蛋白成份。胶原蛋白富含多样性及组织分布的特异性,是与各种组织和器官功能相关的功能性蛋白。胶原蛋白不但在个体的发生、分化以及形成过程中与其它结缔组织一样起着重要的作用,而且与机体的衰老和疾病有极其密切的关系。与此同时,胶原蛋白由于其独特的理化性质、优良的生物相容性以及材料间的兼容性,在许多领域得到了广泛应用。本文对胶原蛋白的种类、性质、产品标准及其应用市场进行了综述。     

Mutagens formed from beta-carbolines with aromatic amines

Norharman, widely distributed in our environment such as cigarette smoke and cooked foods, is not mutagenic to Salmonella strains, but becomes mutagenic to Salmonella typhimurium TA98 and YG1024 with S9 mix in the presence of aromatic amines, including aniline and o-toluidine. Therefore, we have designated norharman as a "co-mutagen". Since, humans are simultaneously exposed to norharman and aromatic amines in daily life, it is important to clarify the mechanisms of its co-mutagenic action to further understanding of the potential genotoxic effects in humans. Regarding the mechanisms of this action of norharman with aniline, a mutagenic compound, 9-(4'-aminophenyl)-9H-pyrido[3,4-b]indole[aminophenylnorharman (APNH)] is produced by their interaction, and converted to the hydroxyamino derivative which eventually forms the DNA adduct, dG-C8-APNH through possible ultimate reactive forms with esterification, and this induces mutations. Also other aminophenyl-beta-carboline compounds, such as 9-(4'-amino-3'-methylphenyl)-9H-pyrido[3,4-b]indole[amino-3'-methylphenylnorharman (3'-AMPNH)], 9-(4'-amino-2'-methylphenyl)-9H-pyrido[3,4-b]indole [amino-2'-methylphenylnorharman (2'-AMPNH)], 9-(4'-aminophenyl)-1-methyl-9H-pyrido[3,4-b]indole[aminophenylharman (APH)] and 9-(4'-amino-3'-methylphenyl)-1-methyl-9H-pyrido[3,4-b]indole[amino-3'-methylphenylharman (AMPH)], have been found on reaction of norharman or harman with aniline or toluidine isomers. These compounds showed mutagenic and clastogenic actions in bacterial and mammalian cells. Among them, APNH demonstrated the most potent activity, and it was most extensively studied. When APNH was administered as a single dose to F344 rats, severe testicular toxicity was observed after 6 days. Moreover, liver preneoplastic lesions (GST-P-positive foci) in the liver clearly developed in animals fed 10-50 ppm of APNH in the diet for 4 weeks. Since, APNH was detected in 24 h urine of rats upon simultaneous administration with norharman and aniline by gavage, it is likely to be also produced from norharman and aniline in the human body. From these findings, it is suggested that aminophenyl-beta-carboline derivatives may be classified as one of the novel types of endogenous mutagens and carcinogens.     

Event-related potentials elicited by social commerce and electronic-commerce reviews

There is an increasing interest regarding the use of electroencephalography (EEG) in social commerce and electronic commerce (e-commerce) research. There are several reviews in the field of social commerce or e-commerce; these have great potential value and mining them is fundamental and significant. To our knowledge, EEG is rarely applied to study these. In this study, we examined the neural correlates of social commerce reviews (SCRs) and e-commerce reviews (ECRs) by using them as stimuli to evoke event-related potentials. All SCRs were from friends through a social media platform, whereas ECRs were from strangers through an e-commerce platform. The experimental design was similar to that of a priming paradigm, and included 40 pairs of stimuli consisting of product information (prime stimulus) and reviews (target stimulus). The results showed that the P300 component was successfully evoked by SCR and ECR stimuli. Moreover, the P300 components elicited by SCRs had higher amplitudes than those elicited by ECRs. These findings indicate that participants paid more attention to SCRs than to ECRs. In addition, the associations between neural responses and reviews in social commerce have the potential to assist companies in studying consumer behaviors, thus permitting them to enhance their social commerce strategies.     

The impact of left common pulmonary vein on cryoballoon ablation of atrial fibrillation. A meta-analysis

IntroductionConflicting results regarding the impact of left common pulmonary vein (LCPV) on clinical outcome of atrial fibrillation (AF) ablation with cryoballoon technology have been reported.MethodsWe systematically searched PubMed and Cochrane library for articles that compared the arrhythmia recurrence rate after cryoballoon ablation between patients with normal pattern PVs and patients with LCPV. Studies of first ablation for persistent and paroxysmal AF using the 28 mm Arctic Front Advance, Medtronic cryoballoon (CB-A) reporting clinical success rates at a mean follow-up of ≥12 months were included. Data were analyzed by applying a random effects model.ResultsA total of 5 studies with a total of 1178 patients met our predefined inclusion criteria. After a mean follow-up of 18.4 months, the overall success rate of CB-A ablation among patients with persistent and paroxysmal AF was 57%; in the LCPV group the success rate was 46% and in the normal anatomical pattern group it was 61%. No significant heterogeneity was noted among the studies (I² = 35.8%; Q (df = 3) = 6.23 p-value = 0.18). Arrhythmia recurrence after CB-A ablation was not statistically significant between the two groups (LogOR 0.24; 95% CI [-0.16-0.63]; p-value = 0.23). No significant difference in PNI was observed between the two groups (p-value = 0.693).ConclusionThe presence of LCPV does not affect the long-term outcome of paroxysmal and persistent atrial fibrillation ablation with 28 mm CB-A compared to normal left PVs pattern.     

Association of Insulin-Like Growth Factor-1 With Polycystic Ovarian Syndrome: A Systematic Review and Meta-analysis

ObjectiveCirculating concentration of insulin-like growth factor (IGF)-1 in patients with polycystic ovary syndrome (PCOS) is still unclear. Therefore, we aimed to investigate the association of IGF-1 with PCOS through this meta-analysis.MethodsLiterature search was conducted through PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (up to July 2022). A manual search was performed on the references of related original research. Then, we applied the random-effects model to evaluate the overall effect size by calculating the standard mean difference and its 95% CI. Subgroup analyses were used to explore the sources of heterogeneity. In addition, a sensitivity analysis was performed and publication bias was assessed.ResultsTwenty studies were included in this meta-analysis involving 657 individuals: 362 patients with PCOS and 295 normal controls. The results of meta-analysis showed that serum IGF-1 levels were significantly higher in patients with PCOS than in controls (standard mean difference, 0.89; 95% CI, 0.34-1.45; P = .002). The final pooled data were determined by the random-effects model because a significant high heterogeneity (I² = 89%) was found. A subgroup analysis based on body mass index showed that elevated IGF-1 level was associated with normal-weight and overweight patients in the PCOS group, but there was no significant association with obesity. The sensitivity analysis indicated that no individual study significantly affected the overall pooled result and no publishing bias was observed.ConclusionThese data suggest that elevated serum IGF-1 levels may not be a major cause of PCOS pathogenesis. Body mass index may be a major determinant of serum IGF-1.