Search

Fenfluramine, an appetite suppressant used for weight loss, can cause significant harm if overdosed. The unauthorized addition of fenfluramine to slimming foods has raised concerns. Currently, no rapid screening method is available for the quick detection of fenfluramine in the field. This study proposes six new haptens with varying spacer arm lengths and hydrophobicity, promising to elicit antibodies capable of being highly specific and strongly binding to fenfluramine. The study found that highly hydrophobic haptens with long spacer arms favored the generation of highly sensitive antibodies. Key interaction forces for antibody recognition of fenfluramine were revealed by intrinsic molecular mechanisms. Based on the above results, monoclonal antibody for fenfluramine was prepared and an ultrasensitive icELISA method with heterologous coating strategies was developed in slimming foods. The IC 50 of the method was 6.25 ng/mL, the linear detection range was 0.47-83.51 ng/mL and the detection limit was 0.10 ng/mL. Recovery rates in tea bags, tablets, capsules, coffee, and beverages ranged from 96.56 % to 108.90 %. The method was successfully applied to blind samples, showing strong correlation with HPLC-MS/MS results. Thus, the developed method is suitable for identifying fenfluramine adulteration in slimming foods., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

Chlorphenamine maleate is a prohibited additive found in herbal teas and health foods. Excessive intake of this substance can result in adverse health effects. In this study, two novel haptens, PEM and bepotastine (PB1), mimicking chlorphenamine maleate structure were designed and synthesized based on molecular simulation for developing two corresponding polyclonal antibodies (PEM-Ab and PB1-Ab), respectively. Afterward, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed to quickly and accurately detect chlorphenamine maleate in herbal teas using PB1-Ab, which has a high sensitivity and specificity. For chlorphenamine maleate, the half-maximal inhibitory concentration (IC 50 ) and limit of detection (LOD) of PB1-Ab under ideal circumstances were found to be 1.18 µg/L and 0.07 µg/L, respectively. Besides, an environmentally friendly sample pre-treatment strategy was employed that allowed easy and effective elimination of complex matrices. The ic-ELISA method observed the average recovery rate from 87.7% to 94.0% with the variance coefficient (CV) ranging from 2.2% to 9.4%. Additionally, the identification of 25 commercially available herbal teas using liquid chromatography-tandem mass spectrometry (LC-MS/MS) further confirmed the validity of our detection. The results of the two methods are consistent. Overall, the proposed ic-ELISA could be an ultrasensitive and reliable method for chlorphenamine maleate adulterated in foods or exposure to the environment.

Background: Human babesiosis is a worldwide disease caused by intraerythrocytic protozoa of the genus Babesia. It is transmitted by bites from ixodid ticks, and mechanically transmitted by blood transfusion. It is primarily treated with quinine and/or atovaquone, which are not readily available in China. In this study, we developed a novel treatment regimen involving doxycycline monotherapy in a patient with severe Babesia venatorum infection as an alternative therapeutic medication. The aim of our study is to provide a guidance for clinical practice treatment of human babesiosis., Case Presentation: A 73-year-old man who had undergone splenectomy and blood transfusion 8 years prior, presented with an unexplained fever, headache, and thrombocytopenia, and was admitted to the Fifth Medical Center of the PLA General Hospital. He was diagnosed with B. venatorum infection by morphological review of thin peripheral blood smears, which was confirmed by multi-gene polymerase chain reaction (PCR), and sequencing of the entire 18s rRNA and partial β-tubulin encoding genes, as well as isolation by animal inoculation. The doxycycline monotherapy regimen (peros, 0.1 g bisindie) was administered following pharmacological guidance and an effective outcome was observed. The patient recovered rapidly following the doxycycline monotherapy. The protozoan load in peripheral blood samples decreased by 88% in hematocrit counts after 8 days, and negative PCR results were obtained after 90 days of follow-up at the hospital. The treatment lasted for 3 months without any side effects or sequelae. The nine-month follow-up survey of the patient did not reveal any signs of recrudescence or anti-babesial tolerance., Conclusions: We have reported a clinical case of successful doxycycline monotherapy for human babesiosis caused by B. venatorum, which provides an optional medical intervention for human babesiosis., (© 2023. The Author(s).)

Human serum albumin (HSA) can bind with numerous drugs, leading to a significant influence on drug pharmacokinetics as well as undesirable drug-drug interactions due to competitive binding. Probing the HSA drug binding site thus offers great opportunities to reveal drug-HSA binding profiles. In the present study, a fluorescent probe ( E )-4-(2-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)vinyl)-1-propylpyridin-1-ium (TTPy) has been prepared, which exhibits enhancement of deep-red to near-infrared (NIR) fluorescence upon HSA binding. The competitive binding assay indicated that TTPy can target the HSA binding site of fenamates, a group of non-steroidal anti-inflammatory drugs (NSAIDs), with moderate binding affinity (1.95 × 10 6 M -1 at 303 K). More interestingly, TTPy enables fluorescent labeling of HSA upon visible light irradiation. This study provides promising ways for HSA drug binding site identification and photochemical protein labeling.

Garcinia biflavonoid 1 (GB1) is one of the active chemical components of Garcinia kola and is reported to be capable of reducing the intracellular lipid deposition, which is the most significant characteristic of non-alcoholic fatty liver disease. However, its bioactive mechanism remains elusive. In the current study, the lipid deposition was induced in HepG2 cells by exposure to oleic acid and palmitic acid (OA&PA), then the effect of GB1 on lipid metabolism and oxidative stress and the role of regulating PPARα in these cells was investigated. We found that GB1 could ameliorate the lipid deposition by reducing triglycerides (TGs) and upregulate the expression of PPARα and SIRT6, suppressing the cell apoptosis by reducing the oxidative stress and the inflammatory factors of ROS, IL10, and TNFα. The mechanism study showed that GB1 had bioactivity in a PPARα-dependent manner based on its failing to improve the lipid deposition and oxidative stress in PPARα-deficient cells. The result revealed that GB1 had significant bioactivity on improving the lipid metabolism, and its potential primary action mechanism suggested that GB1 could be a potential candidate for management of non-alcoholic fatty liver disease.

A growing number of β-agonists are illegally using for reducing animal fat deposition in animals, but the development of analytical methods always lags behind the emergence of new illegal compounds. Therefore, class specificity antibody-based immunoassays that can detect a great many β-agonists are important for timely supervision. In this study, a competitive inhibition enzyme-linked immunosorbent assay (ciELISA) based on a clenbuterol monoclonal antibody was developed to recognize 23 β-agonists and analogues. Holographic and three-dimensional quantitative structure-activity relationship (HQSAR and 3D QSAR) revealed that there are two critical binding epitopes on β-agonist hapten affecting antibody specificity, and these epitopes have been further validated using a ractopamine antibody with narrow specificity. Tert-butyl at C-2' epitope is needed to generate class specific antibodies, and different characteristics of substituents at benzene ring epitope would adjust antibody specificity. This investigation could provide reference for future design of β-agonist haptens., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Enantioselective antibodies have great potential to separate and detect chiral compounds. However, cross-reactivity of enantioselective antibodies to the distomer may limit the application. An in-depth understanding of interactions between antibodies and chiral drugs could be helpful to investigate antibody recognition to the distomer. In this study, a monoclonal antibody against chiral quinolone S -(-)-gatifloxacin ( S -GAT) was produced and its Fab fragment was prepared by proteolysis. The S -GAT Fab exhibited 10% cross-reactivity against the R -enantiomer compared to that of the S -enantiomer in an indirect competitive enzyme-linked immunosorbent assay (icELISA). The crystal structures of the S -GAT Fab apo form and complex with S -GAT were analyzed, and molecular docking of the R -enantiomer was carried out. The ligand conformation was further studied using molecular dynamics simulations. The results showed that the distomer R -enantiomer could enter the chiral center recognition region of the antibody by adjusting the piperazine ring conformation. Meanwhile, the antibody binding cavity had obvious conformational adaptability during ligand binding. It demonstrated that conformational change of both ligand and antibody was the key reason why antibodies recognize the distomer. Restricting conformational adaptability could improve the enantioselective recognition ability of antibodies. This study provided a new explanation for the cross-reactivity of enantioselective antibodies to the distomer, and could help to modulate antibody enantioselectivity for immunoassay of chiral drugs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A mild synthetic method to prepare dihydroquinolines has been presented. These dihydroquinolines, for the first time, showed great potential for fluorescence detection of the important biorelevant hydroxyl radicals ( • OH). Sensitive and selective • OH detection and intracellular organelle-targeted fluorescence imaging of • OH have been demonstrated by using one of the synthetic dihydroquinolines. Moreover, dihydroquinoline has also exhibited promising potential to construct advanced fluorescence probes for • OH with tunable photophysical properties.

Protein citrullination is an important posttranslational modification on an arginine residue. However, high quality fluorescent probes for measuring the citrullination level and capturing citrullinated proteins are quite limited. Inspired by the similarity between acid-promoted citrulline-labeling reaction and aldol reaction, here we present "turn-on" and "turn-off" fluorescent probes for measuring citrulline levels based on the scaffold of aldol sensors. Further application of the modified probe showed great potential to simultaneously monitor and capture citrullinated peptides.

Gene regulation in embryonic stem cells (ESCs) has been extensively studied at the epigenetic-transcriptional level, but not at the posttranscriptional level. Pumilio (Pum) proteins are among the few known translational regulators required for stem-cell maintenance in invertebrates and plants. Here we report the essential function of two murine Pum proteins, Pum1 and Pum2, in ESCs and early embryogenesis. Pum1/2 double-mutant ESCs display severely reduced self-renewal and differentiation, and Pum1/2 double-mutant mice are developmentally delayed at the morula stage and lethal by embryonic day 8.5. Remarkably, Pum1-deficient ESCs show increased expression of pluripotency genes but not differentiation genes, whereas Pum2-deficient ESCs show decreased pluripotency markers and accelerated differentiation. Thus, despite their high homology and overlapping target messenger RNAs (mRNAs), Pum1 promotes differentiation while Pum2 promotes self-renewal in ESCs. Pum1 and Pum2 achieve these two complementary aspects of pluripotency by forming a negative interregulatory feedback loop that directly regulates at least 1,486 mRNAs. Pum1 and Pum2 regulate target mRNAs not only by repressing translation, but also by promoting translation and enhancing or reducing mRNA stability of different target mRNAs. Together, these findings reveal distinct roles of individual mammalian Pum proteins in ESCs and their essential functions in ESC pluripotency and embryogenesis., Competing Interests: The authors declare no competing interest.

A new N2O-type BODIPY probe (LF-Bop) has been proposed for the selective and sensitive detection of biologically relevant small molecular thiols. This detection is based on the Michael addition reaction between the thiol and nitrostyrene groups in the probe, which decreases the quenching effect from the nitro group, thus resulting in the recovery of the deep-red fluorescence from the BODIPY structure. The results show that LF-Bop is able to detect all tested free thiols through a fluorescence turn-on assay. The lowest limit of detection (LOD) for glutathione was found to be down to nanomolar levels (220 nM). Based on this probe, we have developed a new fluorescence assay for the screening of acetylcholinesterase inhibitors. In total, 11 natural and synthetic alkaloids have been evaluated. Both experimental measurements and theoretical molecular docking results reveal that both natural berberine and its synthetic derivative dihydroberberine are potential inhibitors of acetylcholinesterase.

A novel sensitive and selective probe for the important antibiotic vancomycin (Van) has been synthesized by integrating a coumarin and a fluorescein as dual fluorescence reporters and a Van binding peptide D-Ala-D-Ala. Only weak green fluorescence was initially observed, which was mostly attributed to fluorescence self-quenching induced by fluorophore stacking. Upon the binding of Van with the D-Ala-D-Ala peptide, the fluorescence turned on, probably due the disaggregation of fluorophores. The intensity ratio of the dual emission bands I 519 /I 446 exhibited an excellent linear relationship with the concentration of Van increasing from 0-20 μM in synthetic urine. The lowest detection limit was calculated to be 92.8 nM in urine, which made the probe applicable in clinically relevant concentration ranges. The synthetic probe has also shown the potential for Van detection in human serum. More interestingly, this probe has been successfully applied for in vivo imaging of Van in zebrafish. Graphical Abstract.

Primaquine (PMQ), an important anti-malarial drug, has been recommended by the World Health Organization (WHO) for the treatment of life-threatening infections caused by P. vivax and ovale. However, PMQ has unwanted adverse effects that lead to acute hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. There is a need to develop simple and reliable methods for PMQ determination with the purpose of dosage monitoring. In early 2019, we have reported an UV-Vis and naked-eye based approach for PMQ colorimetric quantification. The detection was based on a Griess-like reaction between PMQ and anilines, which can generate colored azo products. The detection limit for direct measurement of PMQ in synthetic urine is in the nanomolar range. Moreover, this method has shown great potential for PMQ quantification from human serum samples at clinically relevant concentrations. In this protocol, we will describe the technical details regarding the syntheses and characterization of colored azo products, the reagent preparation, and the procedures for PMQ determination.

Primaquine (PMQ), a well-known anti-malarial drug, is of increasing importance as people moving toward global malaria eradication. PMQ has serious side effects that it often causes acute hemolytic toxicity in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The development of simple and reliable approaches for quantitative dose monitoring is thus becoming important during malarial treatment with PMQ. Herein, an unexpected Griess reaction on PMQ was systematically studied. The reaction happened between substituted aniline and a primaquine molecule in the presence of nitrite. Both experimental measurements and theoretic calculation showed that UV-vis absorption of the azo products varied because of different electron contributing effects of substituents. Based on the optimized conditions, a novel colorimetric method has been developed for PMQ determination with excellent sensitivity and selectivity. The detection limits for PMQ in water and synthetic urine samples were down to nanomolar range. More importantly, this method has been successfully used to quantify PMQ from human serum samples within clinically relevant concentration ranges., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Marsdenia tenacissima (Roxb.) Wight et Arn is a vine distributed in southwest area of China and used in folk medicine for treatment of tumors. Recent decades of studies on this plant reveal its synergistic effects with certain anticancer drugs in cancer therapy. In our previous study, an extract ETA which contains total aglycones made from M. tenacissima significantly enhanced antitumor activity of paclitaxel in tumor-bearing mice. However, the effective constituents in ETA and the underlying mechanisms remain unclear., Aim of the Study: Reveal the active components in ETA as well as the molecular mechanism in enhancing antitumor efficacy of paclitaxel., Material and Methods: Main constituents in ETA were purified by chemical methods. Effects of the purified constituents on metabolic activity of CYP450 enzymes were evaluated in human liver microsomes. Ability of the constituents to enhance antitumor activity of paclitaxel were investigated in nude mice bearing HeLa tumors. Pharmacokinetic study was performed in SD rats. Molecular docking was carried out for investigation of drug-protein interactions., Results: Three main C 21 steroidal aglycones, 11α-O-tigloyl-12β-O-acetyl-tenacigenin B (MT1), 11α-O-2-methylbutanoyl-12β-O-tigloyl-tenacigenin B (MT2) and 11α-O-2-methylbutanoyl-12β-O-acetyl-tenacigenin B (MT3), together with tenacigenin B (MT4) was prepared from ETA. Among them, MT1, MT2 and MT3 strongly inhibit the metabolic activity of CYP3A4. MT2 also showed inhibitory effects on CYP2C8, CYP2B6 and CYP2C19. In HeLa tumor xenografts, MT1, MT2 and MT3 (30 mg/kg) did not affect tumor growth themselves, but significantly enhanced paclitaxel-induced growth inhibition. In addition, coadministration of MT2 with paclitaxel resulted in significant reduction of liver CYP2C8. In pharmacokinetic study, MT2 significantly increased the blood concentration of paclitaxel with increased AUC value by 2.2-5.3 folds. Molecular docking analysis suggested hydrophobic interaction modes of tenacigenin B derivatives with CYP3A4, and also the essential roles of the C-11 and C-12 ester groups for effective interaction with CYP3A4., Conclusion: Our study proves that, 11α-O-tigloyl-12β-O-acetyl-tenacigenin B, 11α-O-2-methylbutanoyl-12β-O-tigloyl-tenacigenin B and 11α-O-2-methylbutanoyl-12β-O-acetyl-tenacigenin B, which are the main constituents of ETA, are active inhibitors of CYP3A4 with potential to increase therapeutic efficacy of anticancer drugs that are substrates of CYP3A4. Tenacigenin B derivatives with C-11 and C-12 ester group substitutions, or at least a large part of them, are active components in ETA and M. tenacissima to enhance in vivo antitumor efficacies of paclitaxel., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Standard bi-level non-invasive ventilation with fixed-level pressure support (PS) delivery may not maintain ventilation during the changes in pulmonary mechanics that occur throughout day and night, so average volume-assured pressure support (AVAPS) modes that target a preset volume by adjustment of PS may be effective., Objective: Our meta-analysis wants to compare AVAPS and pressure support non-invasive ventilation (PS-NIV) regarding arterial blood gases (ABGs), sleep efficiency and compliance., Method: Relevant publications indexed in PubMed, Cochrane Library, Embase, Web of Science, Wanfang Data, China National Knowledge Infrastructure and VIPI were identified. Appropriate articles identified from the reference lists of the above searches were also reviewed. We included randomized controlled trials involved the use of AVAPS and PS-NIV ventilation for chronic respiratory failure. Each included study weighted mean differences, and 95% confidence intervals (CI) were calculated for continuous outcomes. Statistical heterogeneity was assessed using the I 2 value ≤ 50% were considered as no statistical heterogeneity and used fixed effects model. Otherwise, a random effects model was used., Results: Eight trials were eligible. No significant difference was observed between AVAPS and PS-NIV groups to compare PaCO 2 (OR -0.97, CI-2.54-0.61, P = 0.23) and PaO 2 (OR -1.81, CI-4.29-0.67, P = 0.15) in ABGs. There was no significant difference between the two groups with sleep efficiency (OR -3.31, CI-7.58-0.95, P = 0.13) and visual analog scale (OR 0.32, CI-6.97-7.61, P = 0.93)., Conclusions: The evidence shows there is no significant difference in clinical outcomes when comparing AVAPS and PS-NIV used for chronic respiratory failure patients., (© 2019 John Wiley & Sons Ltd.)

Hydroxyl radical (•OH) is the most reactive oxygen species involved in many environmental and biological processes. The development of simple and reliable methods to quantitatively determine hydroxyl radicals is desired. Herein, a colorimetric strategy based on a modified Griess test has been presented. The detection started with the nitrite release from nitroimidazoles (nIm) upon its specific reaction with •OH radicals and subsequently nitrite quantification by Griess reagent. The result showed that this nitroimidazole modified Griess test (nIm-Griess) was successfully adapted for the measurement of •OH radicals generated by Fenton reaction, water radiolysis, as well as the activation of two antimalarials artemisinin (Art) and dihydroartemisinin (DHA)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Microaspiration of secretions around the tracheal cuff is a multifactorial process. Tracheal cuff shape might take a major part in its occurrence. The rationale for producing a taper-shaped cuff is established on the assumption that compared to a conventional cuff with a single fixed diameter, a continuum of minimum-to-maximum diameter sections might better fit the tracheal walls., Objectives: The primary objective of this meta-analysis was to compare ventilator-associated pneumonia (VAP) between tapered-cuff intubation and conventional-cuff intubation. The secondary objective was to compare intensive care unit (ICU) mortality between tapered-cuff intubation and conventional-cuff intubation., Methods: We searched the Cochrane Library, Embase, MEDLINE database through the PubMed search engine, and CINAHL from inception to April 2018. Randomized trials comparing VAP and ICU mortality between tapered-cuff intubation and conventional-cuff intubation in intubated adults were included. Two review authors assessed study quality and abstracted databasing on prespecified criteria independently., Results: We pooled summary estimates from 5 trials evaluating tapered-cuff involving 774 participants. Compared to VAP, no statistically significant difference was observed between the tapered-cuff and conventional-cuff groups (OR 0.82, CI 0.61-1.12, z  = 1.24, and p =0.21). No statistically significant difference was observed between the tapered-cuff and conventional-cuff groups with ICU mortality (OR 0.77, CI 0.55-1.08, z  = 1.49, and p =0.14)., Conclusions: In this meta-analysis, the tapered-cuff tracheal tube may not be superior to the standard-cuff tracheal tube in reducing VAP and ICU mortality.

As a folk medicine, Moringa oleifera L. is used effectively to treat inflammatory conditions and skin diseases. However, its mechanism of action is not well understood, limiting its medical use. We isolated and identified three compounds, namely niazirin, marumoside A and sitosterol- 3 - O - β -d-glucoside, from the seeds of Moringa oleifera , and studied their effects on the expression of Th17-relevant cytokines (IL-12/IL-23 p40, IL-17A, IL-22 and IL-23 p19) using lipopolysaccharide-stimulated THP-1 cells. Additionally, as Th17 plays a critical role in the pathogenesis of psoriasis, we used a 12 - O -tetradecanoylphorbol- 13 -acetate (TPA)-induced psoriasis-like skin lesion mouse model to study their potential therapeutic application in vivo. The compounds suppressed the expression of IL-12/IL-23 p40, IL-17A, IL-22 and IL-23 p19 in vitro, and in vivo they ameliorated psoriasis-like skin lesions, decreased IL-17A mRNA expression, and increased the expression of keratinocyte differentiation markers. To our knowledge, this is the first report regarding the mechanism and therapeutic application of Moringa oleifera seeds to treat psoriasis-like lesions in vivo.

Influenza viruses represent a serious threat to human health. Although our research group has previously demonstrated the antiviral and anti‑inflammatory activities of eleutheroside B1, a detailed explanation of the mechanism by which it is effective against the influenza virus remains to be elucidated. In the present study, the transcriptomic responses of influenza A virus‑infected lung epithelial cells (A549) treated with eleutheroside B1 were investigated using high‑throughput RNA sequencing, and potential targets were identified using a molecular docking technique, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) assay, and DNA methylation analysis. The transcriptomic data revealed that there are 1,871 differentially expressed genes (DEGs) between the cells infected with the influenza virus strain variant PR8, and the cells infected with PR8 and treated with eleutheroside B1. Among the DEGs, RNA polymerase II subunit A (POLR2A; encoding the largest subunit of RNA polymerase II) and mannosidase α class II member 1 (MAN2A1) were selected from the molecular docking analysis with eleutheroside B1. The docking score of Drosophila melanogaster MAN2A1 (3BVT) was 11.3029, whereas that of POLR2A was 9.0133. The RT‑qPCR results demonstrated that the expression levels of host genes (MAN2A2, POLR2A) and viral genes (PA, PB1, PB2, HA) were downregulated following eleutheroside B1 treatment. Bisulfite‑sequencing PCR was performed to investigate whether eleutheroside B1 was able to modify the DNA methylation of POLR2A, and the results suggested that the average proportion of methylated CpGs (‑222‑72 bp) increased significantly following treatment with eleutheroside B1. Taken together, these findings suggested that eleutheroside B1 may affect N‑glycan biosynthesis, the chemokine signaling pathway, cytokine‑cytokine receptor interaction and, in particular, may target the POLR2A to inhibit the production of influenza virus genes.

Background: The influence of the subglottic secretion drainage (SSD) on the microorganisms of ventilator associated pneumonia (VAP) is still unclear.A meta-analysis focusing on the influence of the SSD on the microorganisms of VAP., Methods: A comprehensive search was conducted through the online studies of PubMed, Embase, Cochrane Library, Google scholar, CNKI (China National Knowledge Infrastructure), and VIPI (Database for Chinese Technical Periodicals) using specific search terms.Included studies were randomized controlled trials (RCTs) that compare the microorganisms of VAP between SSD and standard endotracheal tube care in mechanically ventilated adults., Results: Nine RCTs were eligible. There was no significant difference in the rate of VAP caused by nonfermentative bacteria and enterobacteria between SSD group and control group (OR = 0.73, 95%CI, 0.53-1.01; P = .06). The episodes of VAP caused by Gram-positive cocci and Haemophilus influenzae organisms were lower in the SSD group (OR = 0.29, 95%CI, 0.18-0.48; P<0.00001). Less mean volume of SSD daily was observed in VAP group (OR = -16.97, 95%CI, -29.87-4.08; P = .010)., Conclusion: We found SSD to be associated with significant decreases in VAP caused by Gram-positive cocci and H influenzae organisms but no significant differences in VAP caused by nonfermentative bacteria and enterobacteria. Less mean volume of SSD daily was observed in VAP group.

Immunoassay methods are important for monitoring β-agonists illegally used for reducing animal fat deposition in livestock. However, there is no simultaneous screening surveillance immunoassay for detecting various β-agonist chemicals that are possibly present in food. In this study, through the use of an R-(-)-salbutamol derivative as the immunizing hapten, an antibody recognizing 31 β-agonists and analogues was generated for the first time. Three-dimensional quantitative structure-activity relationship (3D QSAR) revealed that strong steric and hydrophobic fields around the hapten spacer near C-2, as well as a chirality at C-1', dominantly modulated the class specificity of the raised antibody. However, a hapten spacer linked at C-2' or C-1 would lead to a narrow specificity, and the spacer charge at C-6 could affect the raised antibody specificity spectrum. A class specificity competitive indirect enzyme-linked immunosorbent assay (ciELISA) was established with an ideal recovery ranging from 81.8 to 118.3% based on the obtained antibody. With a good agreement to the HPLC/MS method, the proposed ciELISA was confirmed to be reliable for the rapid surveillance screening assay of β-agonists in urine. This investigation will contribute to the rational design and control of the immunoassay specificity.

Activation of axonal growth program is a critical step in successful optic nerve regeneration following injury. Yet the molecular mechanisms that orchestrate this developmental transition are not fully understood. Here we identified a novel regulator, insulin-like growth factor binding protein-like 1 (IGFBPL1), for the growth of retinal ganglion cell (RGC) axons. Expression of IGFBPL1 correlates with RGC axon growth in development, and acute knockdown of IGFBPL1 with shRNA or IGFBPL1 knockout in vivo impaired RGC axon growth. In contrast, administration of IGFBPL1 promoted axon growth. Moreover, IGFBPL1 bound to insulin-like growth factor 1 (IGF-1) and subsequently induced calcium signaling and mammalian target of rapamycin (mTOR) phosphorylation to stimulate axon elongation. Blockage of IGF-1 signaling abolished IGFBPL1-mediated axon growth, and vice versa, IGF-1 required the presence of IGFBPL1 to promote RGC axon growth. These data reveal a novel element in the control of RGC axon growth and suggest an unknown signaling loop in the regulation of the pleiotropic functions of IGF-1. They suggest new therapeutic target for promoting optic nerve and axon regeneration and repair of the central nervous system.

Antibody-based immunoassay methods have been important tools for monitoring drug residues in animal foods. However, because of limited knowledge about the quantitative structure-activity relationships between a hapten and its resultant antibody specificity, antibody production with the desired specificity is still a huge challenge. In this study, the three-dimensional quantitative structure-activity relationship (3D QSAR) was analyzed in accordance with the cross-reactivity of quinolone drugs reacting with the antibody raised by pipemidic acid as the immunizing hapten and compared with the reported cross-reactivity data and their hapten structures. It was found that the specificity of a quinolone antibody was strongly related to the conformation of the hapten used and that hapten conformations shaped like the letters "I", "P", and "Φ" were essential for the desired high specificity with low cross-reactivity, but that the hapten conformation shaped like the letter "Y" led to an antibody with broad specificity and high cross-reactivity. Almost all of the antibodies against quinolones could result from these four hapten conformations. It was first found that the concrete conformations dominated the specificity of the antibody to quinolone, which will be of significance for the accurate hapten design, predictable antibody specificity, and better understanding the recognition mechanism between haptens and the antibodies for immunoassays.

A polyclonal antibody against the quinolone drug pazufloxacin (PAZ) but with surprisingly broad specificity was raised to simultaneously detect 24 quinolones (QNs). The developed competitive indirect enzyme-linked immunosorbent assay (ciELISA) exhibited limits of detection (LODs) for the 24 QNs ranging from 0.45 to 15.16 ng/mL, below the maximum residue levels (MRLs). To better understand the obtained broad specificity, a genetic algorithm with linear assignment of hypermolecular alignment of data sets (GALAHAD) was used to generate the desired pharmacophore model and superimpose the QNs, and then advanced comparative molecular field analysis (CoMFA) and advanced comparative molecular similarity indices analysis (CoMSIA) models were employed to study the three-dimensional quantitative structure-activity relationship (3D QSAR) between QNs and the antibody. It was found that the QNs could interact with the antibody with different binding poses, and cross-reactivity was mainly positively correlated with the bulky substructure containing electronegative atom at the 7-position, while it was negatively associated with the large bulky substructure at the 1-position of QNs.

On the basis of the structural features of (fluoro)quinolones (FQs), pazufloxacin was first used as a generic immunizing hapten to raise a broad-specificity antibody. The obtained polyclonal antibody exhibited broad cross-reactivity ranging from 5.19% to 478.77% with 21 FQs. Furthermore, the antibody was able to recognize these FQs below their maximum residue limits (MRLs) in an indirect competitive chemiluminescence enzyme immunoassay (ic-CLEIA), with the limit of detection (LOD) ranging from 0.10 to 33.83 ng/mL. For simply pretreated milk samples with spiked FQs, the ic-CLEIA exhibited an excellent recovery with a range of 84.6-106.9% and an acceptable coefficient of variation below 15%, suggesting its suitability and reliability for the use of a promising tool to detect FQs. Meanwhile, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models, with statistically significant correlation coefficients (q(2)CoMFA = 0.559, r(2)CoMFA = 0.999; q(2)CoMSIA = 0.559, r(2)CoMSIA = 0.994), were established to investigate the antibody recognition mechanism. These two models revealed that in the antibody, the active cavity binding FQs' 7-position substituents worked together with another cavity (binding FQs' 1-position groups) to crucially endow the high cross-reactivity. This investigation will be significant for better exploring the recognition mechanism and for designing new haptens.

An approach for molecular similarity/substructure searching based on structural hierarchy matching is proposed. In this approach, small molecules are divided into two categories, acyclic and cyclic forms. The latter are further divided into three structural hierarchies, namely, framework, complicated-, and mono-rings. During searching, the similarity coefficients of a structural query and each retrieved molecule are calculated using the hierarchy of the query as the reference. A total of 13,911 chemicals were involved in this work, from which the minimal cyclic and acyclic substructures are extracted, and further processed into fuzzy structural fingerprints. Subsequently, the fingerprints are used as the searching indices for molecular similarity or substructure searching. The tests show that this approach can give user options to choose between one-substructure and multi-substructure searching with sorted results. Moreover, this algorithm has the potential to be developed for molecular similarity searching and substructure analysis.

A central enigma in epigenetics is how epigenetic factors are guided to specific genomic sites for their function. Previously, we reported that a Piwi-piRNA complex associates with the piRNA-complementary site in the Drosophila genome and regulates its epigenetic state. Here, we report that Piwi-piRNA complexes bind to numerous piRNA-complementary sequences throughout the genome, implicating piRNAs as a major mechanism that guides Piwi and Piwi-associated epigenetic factors to program the genome. To test this hypothesis, we demonstrate that inserting piRNA-complementary sequences to an ectopic site leads to Piwi, HP1a, and Su(var)3-9 recruitment to the site as well as H3K9me2/3 enrichment and reduced RNA polymerase II association, indicating that piRNA is both necessary and sufficient to recruit Piwi and epigenetic factors to specific genomic sites. Piwi deficiency drastically changed the epigenetic landscape and polymerase II profile throughout the genome, revealing the Piwi-piRNA mechanism as a major epigenetic programming mechanism in Drosophila., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The miRNA pathway, as a fundamental mechanism of gene regulation, plays a key role in controlling the establishment, self-renewal, and differentiation of stem cells. Such regulation is manifested as fine-tuning the temporal- and tissue-specificity of gene expression. This fine-tuning function is achieved by (1) miRNAs form positive and negative feedback loops with transcription factors and epigenetic factors to exert concerted control of given biological processes; and/or (2) different miRNAs converge to control one or more mRNA targets in a signaling pathway. These regulatory mechanisms are found in embryonic stem cells, iPS cells, and adult tissue stem cells. The distinct expression profiles of miRNAs and their regulatory roles in various types of stem cells render these RNAs potentially effective tools for clinical diagnosis and therapy.

The microRNA (miRNA) pathway, as a fundamental mechanism of gene regulation, plays a key role in controlling the establishment, self-renewal, and differentiation of stem cells. Such regulation is manifested as fine tuning the temporal- and tissue-specificity of gene expression. This fine-tuning function is achieved by (1) miRNAs form positive and negative feedback loops with transcription factors and epigenetic factors to exert concerted control of given biological processes and/or (2) different miRNAs converge to control one or more mRNA targets in a signaling pathway. These regulatory mechanisms are found in embryonic stem cells, iPS cells, and adult tissue stem cells. The distinct expression profiles of miRNAs and their regulatory roles in various types of stem cells render these RNAs potentially effective tools for clinical diagnosis and therapy., (Copyright © 2011 Wiley Periodicals, Inc.)

Two new 13,28-epoxy oleanane-type triterpenoids, namely heterogenoside E and F, were isolated from Lysimachia heterogenea Klatt, together with the eight known compounds: palmitic acid, β-stigmasterol, kaempferol, quercetin, hyperin, isorhamnetin, isorhamnetin-3-O-galactopyranoside and anagallisin C. Heterogenoside F possesses acetoxyl groups at the unusual C-21 and C-22 positions of its oleanane skeleton. The cytotoxic activities of anagallisin C, heterogenoside E and F were weak.

Canalization, also known as developmental robustness, describes an organism's ability to produce the same phenotype despite genotypic variations and environmental influences. In Drosophila, Hsp90, the trithorax-group proteins and transposon silencing have been previously implicated in canalization. Despite this, the molecular mechanism underlying canalization remains elusive. Here using a Drosophila eye-outgrowth assay sensitized by the dominant Kr(irregular facets-1)(Kr(If-1)) allele, we show that the Piwi-interacting RNA (piRNA) pathway, but not the short interfering RNA or micro RNA pathway, is involved in canalization. Furthermore, we isolated a protein complex composed of Hsp90, Piwi and Hop, the Hsp70/Hsp90 organizing protein homolog, and we demonstrated the function of this complex in canalization. Our data indicate that Hsp90 and Hop regulate the piRNA pathway through Piwi to mediate canalization. Moreover, they point to epigenetic silencing of the expression of existing genetic variants and the suppression of transposon-induced new genetic variation as two major mechanisms underlying piRNA pathway-mediated canalization.

Cytotoxicity-guided phytochemical analysis on the extract of Lysimachia heterogenea Klatt led to the isolation of 3beta,16beta-12-oleanene-3,16,23,28-tetrol (1) and its four new oligosaccharidic derivatives heterogenosides A, B, C, and D (2-5). Their structural elucidation was mainly based on NMR and mass spectral data. The time course experimental results indicated that unlike the likely lysis activity of heterogenosides B-D, heterogenoside A showed a significantly time-dependent cytotoxicity.

The gland cells were successfully collected from the stems of Lysimachia fordiana Oliver, and the homologous pigments of fordianin A, fordianin B, fordianaquinone A and fordianaquinone B were firstly detected in the glands by HPLC. This indicated that the stem was an ideal material for the preparation of the glands, and the gland was a center for the polycyclic pigments accumulation in this species.

3'-Deoxy-4-O-methylepisappanol, a new 3-benzylchroman derivative, was isolated from Sappan Lignum, together with thirteen known chemical compounds identified as protosappanin A, sappanchalcone, sappanone B, palmitic acid, (+)-(8S,8'S)-bisdihydrosiringenin, brazilein, 3-deoxysappanchalcone, (+)-lyoniresinol, 3-deoxysappanone B, protosappanin B, isoprotosappanin B, 3'-O-methylbrazilin and brazilin, respectively. Among these known compounds, this is the first time that (+)-(8S,8'S)-bisdihydrosiringenin was obtained from the family Caesalpiniaceae.

Tenacissimoside A (1) and 11alpha-O-benzoyl-12beta- O-acetyltenacigenin B (2), two derivatives of tenacigenin B (3) from the plant Marsdenia tenacissima, reversed multidrug resistance in P-glycoprotein (Pgp)-overexpressing multidrug-resistant cancer cells. The sensitivity of HepG2/Dox cells to the antitumor drugs doxorubicin, vinblastine, puromycin, and paclitexel was increased by 18-, 10-, 11-, and 6-fold by 20 microg/mL (or 25 microM) of 1 and 16-, 53-, 16-, and 326-fold by 20 microg/mL (or 39 microM) of 2, respectively. A preliminary mechanistic study has suggested that 1 might modulate Pgp-mediated multidrug resistance through directly interacting with the Pgp substrate site.

Objective: To investigate the chemical constituents in the ethyl acerate extract of Lysimachia fortunei., Method: The compounds were isolated by silica gel chromatography, and their structures were elucidated by NMR data and references., Result: Nine natural constituents were isolated, and their structures were identified as 9, 19-cyclolanost-24-en-3-one (1), 24-ethyl-5alpha-cholesta-7, 22(E)-dien-3-one (2), 1-pentatriacontanol (3), beta-stigmasterol (4), 24-ethyl-5alpha-cholesta-7, 22(E)-dien-3beta-ol (5), palmitic acid (6), isorhamnetin (7), kaempferol (8) and quercetin (9) respectively., Conclusion: All compounds mentioned above were isolated from this plant for the first time, and compound 1, 2 and 5 were obtained from the genus for the first time.

A new poly-substituted benzaldehyde, 1, and a known compound quercetin (2) were isolated from the leaves of Lysimachia fordiana Oliv. The structure of compound 1, named fordianol, was determined as 2-heptyl-3,6-dihydroxy-4- methoxybenzaldehyde on the basis of spectroscopic methods. Fordianol did not inhibit the growth of SWO-38 (human brain neuroglioma), MCF-7 (human breast cancer) or HeLa (human cervical carcinoma) cell lines.

Objective: To observe the effect of Fuzheng Jiangan formula( FZJGF) on liver fibrosis using immune induced liver fibrosis rat model., Method: The rat models with immunity liver fibrosis were induced by the human serum albumin. Rats were treated with normal saline, FZJGF (9. 85,39. 4 g x kg(-1) , two dosage groups) and Colchicine (0. 000 1 g . kg(-1) ). The activities of ALT, AST, contents of ALB and TP, and A/G, The contents of Laminin (LN), Hyaluronic acid (HA) and collagen type IV (IV-C) in rat serum were measured by radioimmunoassay method. The level of hydroxyproline (Hyp) in liver was detected by chemistry method. The pathological changes of liver tissue were observed by HE and Von-Gieson staining., Result: FZJGF could significant decrease the serum activities of ALT and AST, and increase the levels of TP,Alb and ratio A/G. The levels of LN, HA and IV-C were decreased significantly after the treatment using FZJGF. The pathological improvements were observed. FZJGF could markedly alleviate the deposition of collageneous fiber, and reduce the liver pseudoluboli and the fibrosis scores in the liver tissue compared with model group., Conclusion: FZJGF can inhibit formation and development of rat hepatic fibrosis induced by the human serum albumin.