Identifying individual's distractor suppression using functional connectivity between anatomical large-scale brain regions.

Distractor suppression (DS) is crucial in goal-oriented behaviors, referring to the ability to suppress irrelevant information. Current evidence points to the prefrontal cortex as an origin region of DS, while subcortical, occipital, and temporal regions are also implicated. The present study aimed to examine the contribution of communications between these brain regions to visual DS. To do it, we recruited two independent cohorts of participants for the study. One cohort participated in a visual search experiment where a salient distractor triggering distractor suppression to measure their DS and the other cohort filled out a Cognitive Failure Questionnaire to assess distractibility in daily life. Both cohorts collected resting-state functional magnetic resonance imaging (rs-fMRI) data to investigate function connectivity (FC) underlying DS. First, we generated predictive models of the DS measured in visual search task using resting-state functional connectivity between large anatomical regions. It turned out that the models could successfully predict individual's DS, indicated by a significant correlation between the actual and predicted DS (r = 0.32, p < 0.01). Importantly, Prefrontal-Temporal, Insula-Limbic and Parietal-Occipital connections contributed to the prediction model. Furthermore, the model could also predict individual's daily distractibility in the other independent cohort (r = -0.34, p < 0.05). Our findings showed the efficiency of the predictive models of distractor suppression encompassing connections between large anatomical regions and highlighted the importance of the communications between attention-related and visual information processing regions in distractor suppression. Current findings may potentially provide neurobiological markers of visual distractor suppression.

MicroRNA­203a­3p improves bleomycin and pingyangmycin sensitivity by inactivating the PI3K/AKT pathway in hemangioma.

MicroRNAs (miRs) have been found to play a fundamental role in the pathology and progression of hemangioma. Of note, miR-203a-3p prevents hemangioma progression via inactivation of the PI3K/AKT pathway. Bleomycin and pingyangmycin are drugs used in sclerotherapy, but certain hemangioma patients experience drug resistance, leading to poor clinical outcomes. The present study aimed to explore the impact of miR-203a-3p on bleomycin and pingyangmycin sensitivity in hemangioma, as well as the involvement of the PI3K/AKT pathway. miR-203a-3p or negative control mimics were transfected into human hemangioma endothelial cells, which were treated with 0-20 µM bleomycin or pingyangmycin. Subsequently, 740 Y-P, a PI3K/AKT pathway agonist, was added. Cell viability, rate of apoptosis and the expression levels of proteins involved in the PI3K/AKT pathway, including phosphorylated (p)-PI3K, PI3K, p-AKT and AKT, were detected. miR-203a-3p overexpression significantly decreased the half-maximal inhibitory concentration (IC50) values of bleomycin (5.84±0.87 vs. 14.23±2.17 µM; P<0.01) and pingyangmycin (5.13±0.55 vs. 12.04±1.86 µM; P<0.01), compared with untreated cells. In addition, under bleomycin or pingyangmycin treatment, miR-203a-3p overexpression significantly reduced the proportion of EdU positive cells (both P<0.05) and B-cell leukemia/lymphoma-2 (BCL2) protein expression levels (both P<0.05), whilst increasing cell apoptosis rate (both P<0.05) and cleaved caspase 3 protein expression levels (both P<0.05) compared with untreated controls. Furthermore, miR-203a-3p overexpression significantly inhibited the phosphorylation of PI3K and AKT (both P<0.05), an effect that was significantly diminished by 740 Y-P treatment (both P<0.01). In addition, 740 Y-P significantly increased IC50 values of bleomycin (P<0.01) and pingyangmycin (P<0.001) and also significantly increased the proportion of EdU-positive cells and BCL2 protein expression levels, while decreasing the apoptosis rate and cleaved caspase 3 protein expression levels in cells treated with bleomycin or pingyangmycin (all P<0.05). Of note, 740 Y-P weakened the effect of miR-203a-3p overexpression on the aforementioned cellular characteristics. The present study demonstrated that miR-203a-3p improved the sensitivity of cells to bleomycin and pingyangmycin treatment by inhibiting PI3K/AKT signaling in hemangioma.

Value of optical coherence tomography measurement of macular thickness and optic disc parameters for glaucoma screening in patients with high myopia.

BACKGROUND: The basic method of glaucoma diagnosis is visual field examination, however, in patients with high myopia, the diagnosis of glaucoma is difficult. AIM: To explore the value of optical coherence tomography (OCT) for measuring optic disc parameters and macular thickness as a screening tool for glaucoma in patients with high myopia. METHODS: Visual values (contrast sensitivity, color vision, and best-corrected visual acuity) in three groups, patients with high myopia in Group A, patients with high myopia and glaucoma in Group B, and patients with high myopia suspicious for glaucoma in Group C, were compared. Optic disc parameters, retinal nerve fiber layer (RNFL) thickness, and ganglion cell layer (GCC) thickness were measured using OCT technology and used to compare the peri-optic disc vascular density of the patients and generate receiver operator characteristic (ROC) test performance curves of the RNFL and GCC for high myopia and glaucoma. RESULTS: Of a total of 98 patients admitted to our hospital from May 2018 to March 2022, totaling 196 eyes in the study, 30 patients with 60 eyes were included in Group A, 33 patients with 66 eyes were included in Group B, and 35 patients with 70 eyes were included in Group C. Data were processed for Groups A and B to analyze the efficacy of RNFL and GCC measures in distinguishing high myopia from high myopia with glaucoma. The area under the ROC curve was greater than 0.7, indicating an acceptable diagnostic value. CONCLUSION: The value of OCT measurement of RNFL and GCC thickness in diagnosing glaucoma in patients with high myopia and suspected glaucoma is worthy of development for clinical use.

MicroRNA­203a­3p suppresses endothelial cell proliferation and invasion, and promotes apoptosis in hemangioma by inactivating the VEGF­mediated PI3K/AKT pathway.

Our previous study demonstrated that microRNA-203a-3p (miR-203a-3p) was involved in the regulation of long non-coding RNA MEG8-mediated the progression of hemangioma, which is a benign tumor characterized by endothelial hyperplasia in the blood vessels and primarily occurring in infants and females. Therefore, the present study aimed to further investigate the effects of miR-203a-3p on endothelial cell proliferation, invasion and apoptosis, as well as its underlying mechanism in hemangioma. Human hemangioma endothelial cells (HemECs) were first transfected with either miR-203a-3p mimics or a miR-203a-3p inhibitor. Subsequently, vascular endothelial growth factor A (VEGFA) was overexpressed in these cells. Cell proliferation (by Cell Counting Kit-8 assay), apoptosis (by TUNEL assay), invasion (by Transwell assay) and PI3K/AKT signaling (by western blot) were assessed following transfection of these cells. Notably, transfection with miR-203a-3p mimics caused a reduction in cell proliferation, invasion and in the phosphorylation levels of PI3K and AKT, and promoted cell apoptosis in HemECs. By contrast, transfection with the miR-203a-3p inhibitor exerted the opposite effects compared with those of the miR-203a-3p mimics. miR-203a-3p was revealed to directly suppress VEGFA expression in HemECs. VEGFA overexpression alone increased cell proliferation and invasion, but decreased apoptosis. Furthermore, VEGFA co-transfection reversed the effects mediated by miR-203a-3p mimics transfection in HemECs. Mechanistically, miR-203a-3p was demonstrated to inactivate the PI3K/AKT pathway, whereas VEGFA overexpression produced the opposite effect. VEGFA co-transfection also attenuated the miR-203a-3p mimics-induced inactivation of PI3K/AKT signaling in HemECs. In conclusion, these data suggested that miR-203a-3p may inhibit endothelial cell proliferation and invasion, and promote apoptosis by inactivating VEGFA and PI3K/AKT signaling in hemangioma. These findings also implicated miR-203 as a possible treatment option for this disease.

Neural circuit control of innate behaviors.

All animals possess a plethora of innate behaviors that do not require extensive learning and are fundamental for their survival and propagation. With the advent of newly-developed techniques such as viral tracing and optogenetic and chemogenetic tools, recent studies are gradually unraveling neural circuits underlying different innate behaviors. Here, we summarize current development in our understanding of the neural circuits controlling predation, feeding, male-typical mating, and urination, highlighting the role of genetically defined neurons and their connections in sensory triggering, sensory to motor/motivation transformation, motor/motivation encoding during these different behaviors. Along the way, we discuss possible mechanisms underlying binge-eating disorder and the pro-social effects of the neuropeptide oxytocin, elucidating the clinical relevance of studying neural circuits underlying essential innate functions. Finally, we discuss some exciting brain structures recurrently appearing in the regulation of different behaviors, which suggests both divergence and convergence in the neural encoding of specific innate behaviors. Going forward, we emphasize the importance of multi-angle and cross-species dissections in delineating neural circuits that control innate behaviors.

Evaluation of GeneXpert vanA/vanB in the early diagnosis of vancomycin-resistant enterococci infection.

PURPOSE: Vancomycin-resistant enterococci infection is a worrying worldwide clinical problem. To evaluate the accuracy of GeneXpert vanA/vanB in the diagnosis of VRE, we conducted a systematic review in the study. METHODS: Experimental data were extracted from publications until May 03 2021 related to the diagnostic accuracy of GeneXpert vanA/vanB for VRE in PubMed, Embase, Web of Science and the Cochrane Library. The accuracy of GeneXpert vanA/vanB for VRE was evaluated using summary receiver to operate characteristic curve, pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. RESULTS: 8 publications were divided into 3 groups according to two golden standard references, vanA and vanB group, vanA group, vanB group, including 6 researches, 5 researches and 5 researches, respectively. The pooled sensitivity and specificity of group vanA and vanB were 0.96 (95% CI, 0.93-0.98) and 0.90 (95% CI, 0.88-0.91) respectively. The DOR was 440.77 (95% CI, 37.92-5123.55). The pooled sensitivity and specificity of group vanA were 0.86 (95% CI, 0.81-0.90) and 0.99 (95% CI, 0.99-0.99) respectively, and those of group vanB were 0.85 (95% CI, 0.63-0.97) and 0.82 (95% CI, 0.80-0.83) respectively. CONCLUSION: GeneXpert vanA/vanB can diagnose VRE with high-accuracy and shows greater accuracy in diagnosing vanA.

Knockdown of lncRNA MEG8 inhibits cell proliferation and invasion, but promotes cell apoptosis in hemangioma, via miR­203­induced mediation of the Notch signaling pathway.

As a member of the long non­coding (lnc)RNA family, lncRNA maternally expressed 8, small nucleolar RNA host gene (MEG8), has been reported to serve an oncogenic role in several types of malignancies, including hepatocellular carcinoma, non­small cell lung cancer and pancreatic cancer. The current study aimed to investigate the effect of the knockdown of MEG8 on human hemangioma endothelial cell (HemEC) proliferation, apoptosis and invasion, in addition to determining the underlying molecular mechanism. The knockdown of lncRNA MEG8 was achieved by transfecting lncRNA MEG8 small interfering (si)RNA into HemECs, while the combined knockdown of lncRNA MEG8 knockdown and microRNA (miR)­203 was established by co­transfecting lncRNA MEG8 siRNA and a miR­203 inhibitor into HemECs. The cell proliferation, apoptosis and invasion and the expression levels of miR­34a, miR­200b, miR­200b and Notch signaling pathway­related factors were detected via CCK­8 Kit, flow cytometry, Transwell, reverse transcription­quantitative PCR and western blot assay, respectively. The knockdown of lncRNA MEG8 significantly inhibited proliferation (P<0.05) and invasion (P<0.05), but promoted apoptosis (P<0.01) in HemECs. Furthermore, lncRNA MEG8 knockdown upregulated miR­203 (P<0.01) expression, but did not alter miR­34a or miR­200b expression (both P>0.05). Subsequent experiments revealed that miR­203 silencing exerted no significant effect on the expression levels of lncRNA MEG8 (P>0.05) in HemECs. In addition, miR­203 silencing increased cell proliferation (P<0.05) and invasion (P<0.01), but suppressed apoptosis (P<0.05). miR­203 silencing also reversed the effect of lncRNA MEG8 knockdown on the proliferation (P<0.05), apoptosis (P<0.001) and invasion (P<0.01) of HemECs. Moreover, lncRNA MEG8 knockdown downregulated jagged canonical notch ligand 1 (JAG1; P<0.05) and Notch1 (P<0.05) expression levels, while miR­203 silencing upregulated JAG1 (P<0.01) and Notch1 (P<0.01) expression levels and reversed the effects of lncRNA MEG8 knockdown on JAG1 (P<0.01) and Notch1 (P<0.01) expression in HemECs. In conclusion, the findings of the present study suggested that lncRNA MEG8 knockdown may inhibit cell proliferation and invasion, but promote cell apoptosis in hemangioma via miR­203­induced mediation of the Notch signaling pathway.

Evaluation of Xpert GBS assay and Xpert GBS LB assay for detection of Streptococcus agalactiae.

BACKGROUND: Group B Streptococcal (GBS) infection is the primary agent of neonatal morbidity and mortality. Rapid and simple methods to detect GBS are Xpert GBS and GBS LB assays based on real-time polymerase chain reaction (PCR). However, since the diagnostic accuracy of the two techniques in diagnosing GBS remains unclear, we designed this study to appraise the diagnostic accuracy of the aforementioned. METHODS: A systematic search of all literature published before July 16, 2020 was conducted using Embase, PubMed, Web of Science, and Cochrane Library. The study quality was evaluated through Review Manager 5.3. Accordingly, data extracted in the included studies were analyzed using Meta-DiSc 1.4 and Stata 12.0 software. The diagnosis odds ratio (DOR) and bivariate boxplot were utilized to evaluate the heterogeneity. Publication bias was appraised by using Deeks' funnel plot. RESULTS: A total of 13 studies were adopted and only 19 sets of data met the criteria. The sensitivity and specificity of Xpert GBS were 0.91 (95% CI 0.89-0.92) and 0.93 (95% CI 0.92-0.94). The area under the curve (AUC) was 0.9806. The sensitivity and specificity results of Xpert GBS LB were 0.96 (95% CI 0.95-0.98) and 0.94 (95% CI 0.92-0.95), respectively. The AUC was 0.9950. No publication bias was found. CONCLUSIONS: The Xpert GBS and GBS LB assays are valuable alternative methods with high sensitivity and specificity. However, determining whether they can be used as clinical diagnostic standards for GBS is essential for the future.

Specific Hypothalamic Neurons Required for Sensing Conspecific Male Cues Relevant to Inter-male Aggression.

The hypothalamus regulates innate social interactions, but how hypothalamic neurons transduce sex-related sensory signals emitted by conspecifics to trigger appropriate behaviors remains unclear. Here, we addressed this issue by identifying specific hypothalamic neurons required for sensing conspecific male cues relevant to inter-male aggression. By in vivo recording of neuronal activities in behaving mice, we showed that neurons expressing dopamine transporter (DAT+) in the ventral premammillary nucleus (PMv) of the hypothalamus responded to male urine cues in a vomeronasal organ (VNO)-dependent manner in naive males. Retrograde trans-synaptic tracing further revealed a specific group of neurons in the bed nucleus of the stria terminalis (BNST) that convey male-relevant signals from VNO to PMv. Inhibition of PMvDAT+ neurons abolished the preference for male urine cues and reduced inter-male attacks, while activation of these neurons promoted urine marking and aggression. Thus, PMvDAT+ neurons exemplify a hypothalamic node that transforms sex-related chemo-signals into recognition and behaviors.

Insights into the Mechanism of n-Hexane Reforming over a Single-Site Platinum Catalyst.

We demonstrate that the single-site catalyst Pt1/CeO2 greatly enhances the selectivity of cyclization and aromatization in the n-hexane reforming reaction. Specifically, the selectivity of single-site Pt1/CeO2 toward both cyclization and aromatization is above 86% at 350 °C. The turnover frequency of Pt1/CeO2 is 58.8 h-1 at 400 °C, which is close to that of Pt cluster/CeO2 (61.4 h-1) and much higher than that of Pt nanoparticle/CeO2 with Pt sizes of 2.5 and 7 nm. On the basis of the catalytic results for methylcyclopentane reforming, the dehydrocyclization and further aromatization of n-hexane are attributed to the prominent adsorption of ring intermediate products on the single-site Pt1/CeO2 catalysts. On the other side, with the multiple Pt adjacent active sites, the cluster and nanoparticle Pt/CeO2 samples favor the C-C bond cracking reaction. Ultimately, this in-depth study unravels the principles of hydrocarbon activation with different Pt sizes and represents a key step toward the rational design of new heterogeneous catalysts.

miR-874-3p inhibits cell migration through targeting RGS4 in osteosarcoma.

BACKGROUND: The present study explored the role and mechanism of microRNA-874-3p (miR-874-3p) in the migration of the osteosarcoma cell line, U-2 OS. METHODS: The expression profile of osteosarcoma (OS) microRNA (GSE65071) datasets was downloaded from the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo) to identify differentially expressed miRNAs in OS and its biological functions. A quantitative reverse transcription-polymerase chain reaction was performed to detect the expression of miR-874-3p and its target gene regulator of G protein 4 (RGS4) in human osteosarcoma cells U-2 OS and normal osteoblast hFOB1.19. Plasmid overexpression miR-874-3p and pcDNA-RGS4 were transfected into U-2 OS using Lipofectamine 2000 (Thermo Fisher, Waltham, MA, USA). Cell migration was measured using Transwell migration assays. Bioinformatic analysis and luciferase reporter assay were conducted to search for the target gene of miR-874-3p. RESULTS: In total, 167 differentially expressed miRNAs were detected after the analysis of GSE65071; of which 78 were up-regulated genes and 89 were down-regulated. miR-874-3p was down-regulated and selected for further analysis. The expression level of miR-874-3p in U-2 OS cells was significantly decreased compared to the hFOB1.19 cell line (p < 0.05). Overexpression of miR-874-3p significantly inhibited the proliferation and migration of U-2 OS cells and overexpression of RGS4 reversed the inhibitory effect of miR-874-3p on U-2 OS cells. Through luciferase report analyses and bioinformatic analysis, RGS4 may be the candidate target gene of miR-874-3p. CONCLUSIONS: In conclusion, overexpression of miR-874-3p suppressed OS cell proliferation and migration. Thus, miR-874-3p might present a therapeutic agent for the treatment of OS.

VMHvl-Projecting Vglut1+ Neurons in the Posterior Amygdala Gate Territorial Aggression.

Despite being innate, displays of aggression are influenced by cortical activities. Here, using Vglut1 as a marker for inputs from cortical structures, we identify a small population of excitatory neurons located in the posterior amygdala (PA) that project to the ventrolateral division of ventromedial nucleus of the hypothalamus (VMHvl), a region that critically regulates territorial aggression. Indeed, activities of PA Vglut1+ (PAVglut1) neurons, as analyzed by post hoc c-Fos expression, differentiate trials in which attacks occur, or not, during resident-intruder assays. More importantly, chemogenetic activation of VMHvl-projecting PAVglut1 neurons robustly promote aggression while inhibition of these neurons reduces attacks. Finally, a connectivity map places VMHvl-projecting PAVglut1 neurons at the interface between emotion regulation and aggression as they receive broad inputs from limbic structures and project collaterally to the VMHvl and other targets. Taken together, these results point to VMHvl-projecting PAVglut1 neurons as a potential site for cortical gating of territorial aggression.

[Effects of phytoremediation on soil enzyme activity and thermodynamic characteristics of enzymatic reaction in severe saline-alkali land.] / æ¤è¢«ä¿®å¤å¯¹é‡åº¦ç›ç¢±åœ°åœŸå£¤é ¶æ´»æ€§å’Œé ¶ååº”çƒ­åŠ›å­¦ç‰¹å¾çš„å½±å“.

With the environmental changes and the increases of anthropogenic disturbance, the area and degree of salinization in saline-alkaline lands of Songnen Plain have been increasing with an unprecedented rate. In this study, the effects of restoration of natural vegetation, Leymus chinensis, Avena sativa and Medicago sativa, on the enzymatic activities and thermomechanical characteristics of enzyme catalyzed reaction of two oxidoreductases (catalase, polyphenol oxidase) and three hydrolases (alkaline phosphatase, sucrase, urease) were investigated in heavily saline-alkaline soils from western Songnen Plain. The results showed that the activities of those five soil enzyme as well as the activation free energy (ΔG) increased with increasing temperature, reaching respective maximum at 40 and 45 ℃. The activation enthalpy (ΔH) and entropy (ΔS) of soil enzyme did not change with increasing temperature. The temperature coefficient (Q10) slightly changed and ranged from 1.05 to 1.36 by every 10 ℃ enhancement of temperature. Compared with the bare land, catalase activity increased in natural vegetation and L. chinensis rehabilitated land, but decreased in A. sativa and M. sativa remediation land. The change of ΔG of catalase showed a contrary trend with that of enzyme activities, while ΔH and ΔS increased in the restoration areas of L. chinensis and A. sativa, and decreased in the restoration of natural vegetation and M. Sativa. The activity of polyphenol oxidase decreased or remained unchanged in all restoration sites, and ΔH and ΔS decreased in natural vegetation and L. chinensis restoration sites, while remained unchanged in A. sativa and M. sativa restoration sites. ΔG of polyphenol oxidase reached the maximum at 40 ℃ in each restoration site and decreased or remained unchanged at other temperatures. The activities of three hydrolytic enzymes increased in each restoration site compared with the bare land, and the ΔG of the enzymes decreased or remained unchanged in each repaired area, while ΔH and ΔS varied greatly among the restoration sites. Taken together, significant responses of soil enzyme activity and their thermodynamic characteristics to temperature change and vegetation restoration were detected, which would provide better understanding for the restoration of heavily salinized soil.

Medial preoptic area in mice is capable of mediating sexually dimorphic behaviors regardless of gender.

The medial preoptic area (mPOA) differs between males and females in nearly all species examined to date, including humans. Here, using fiber photometry recordings of Ca2+ transients in freely behaving mice, we show ramping activities in the mPOA that precede and correlate with sexually dimorphic display of male-typical mounting and female-typical pup retrieval. Strikingly, optogenetic stimulation of the mPOA elicits similar display of mounting and pup retrieval in both males and females. Furthermore, by means of recording, ablation, optogenetic activation, and inhibition, we show mPOA neurons expressing estrogen receptor alpha (Esr1) are essential for the sexually biased display of these behaviors. Together, these results underscore the shared layout of the brain that can mediate sex-specific behaviors in both male and female mice and provide an important functional frame to decode neural mechanisms governing sexually dimorphic behaviors in the future.

Plasmonic nanohalo optical probes for highly sensitive imaging of survivin mRNA in living cells.

A strategy is designed for sensitive detection of tumor biomarker survivin mRNA based on resonance Rayleigh scattering of a single AuNP nanohalo probe that couples large gold nanoparticles (L-AuNPs, 52 nm) with small AuNPs (S-AuNPs, 18 nm) through the affinity interaction between streptavidin and biotin. This core-satellite plasmon ruler is further applied to imaging survivin mRNA in living cells.

Dual-Wavelength Electrochemiluminescence Ratiometry Based on Resonance Energy Transfer between Au Nanoparticles Functionalized g-C3N4 Nanosheet and Ru(bpy)3(2+) for microRNA Detection.

Here, a dual-wavelength ratiometric electrochemiluminescence (ECL) approach is reported based on resonance energy transfer (RET) from graphite-like carbon nitride nanosheet (g-C3N4 NS) to Ru(bpy)3(2+) for sensitive detection of microRNA (miRNA). In this approach, Au nanoparticles (Au NPs) functionalized g-C3N4 NS nanohybrid (Au-g-C3N4 NH) coated on glassy carbon electrode (GCE) could exhibit strong and stable ECL emissions with emission peak centered at 460 nm. The ECL emission at such wavelength matched well with the absorption peak of Ru(bpy)3(2+) as well as impeccably stimulating the emission of Ru(bpy)3(2+) at the wavelength of 620 nm, producing ECL-RET with high efficiency. Thus, based on the ECL signals quenching at 460 nm and increasing at 620 nm, a dual-wavelength ratiometric ECL-RET system was achieved. This system was then utilized for determination of target miRNA. With the attachment of thiol-modified molecular beacon on Au-g-C3N4 NH, target miRNA hybridized with the molecular beacon to form a DNA-RNA duplex. The obtained DNA-RNA duplex could be cleaved by duplex-specific nuclease to release target miRNA which would take part in the next cycle for further hybridization. Finally, the introducing of Ru(bpy)3(2+) was through the probe DNA-Ru(bpy)3(2+) complementary with the rest single-strand DNA on electrode. By measuring the ratio of ECL(460 nm)/ECL(620 nm), we could accurately quantify the concentration of miRNA-21 in a wide range from 1.0 fM to 1.0 nM. This work provides an important reference for the study of dual-wavelength ECL ratiometry and also exhibits potential capability in the detection of nucleic acids.

Oriented assembly of invisible probes: towards single mRNA imaging in living cells.

Due to the complexity of biological systems and the ultralow concentration of analytes, improving the signal-to-noise ratio and lowering the limit of detection to allow highly sensitive detection is key to biomolecule analysis, especially intracellular analysis. Here, we present a method for highly sensitive imaging of mRNA in living cells by using novel invisible oriented probes to construct a turn-on signal generation mechanism from zero background. Two DNA probes (S1 and S2) are asymmetrically modified on two small gold nanoparticles (AuNPs) with a diameter of 20 nm. The hybridization of the two DNA probes with a single target mRNA leads to the formation of an AuNP dimer which shows a prominent plasmonic coupling effect. It generates a strong scattering signal from zero-background under a dark-field spectral analysis system. The unique design of the oriented assembly dimer has the ability to easily discriminate the target signal from the inherent cellular background noise in intracellular detection, thus making this approach a valuable technique for imaging single survivin mRNA and monitoring the distribution of survivin mRNA in tumor cells.

Association of monocyte chemoattractant protein-1 (MCP-1)2518A/G polymorphism with proliferative diabetic retinopathy in northern Chinese type 2 diabetes.

BACKGROUND: The pathogenesis of proliferative diabetic retinopathy (PDR) remains poorly understood. Recent studies have implicated that monocyte chemoattractant protein-1 (MCP-1) is associated with diabetic microvascular or macrovascular complications. However, the relationship between single nucleotide polymorphism(SNP)c.2518A/G -rs1024611 in the MCP-1 gene with diabetic retinopathy remains controversial. In the present study, we evaluated the association of SNP in the MCP-1 gene with diabetic retinopathy (DR) and diabetic macular edema (DME) in a Chinese population from Northern China with type 2 diabetes. METHODS: We conducted a case-control study, which enrolled 1,043 subjects with type 2 diabetes (528 with DR, including 277PDR; 515 without DR), and SNP genotyping of c.2518A/G in the MCP-1 gene was performed using the polymerase chain reaction. Genomic DNA was isolated from 3 ml samples of whole blood using a modified conventional DNA extraction method. The genotype and allele frequencies of 2518A/G were studied by using an automated DNA sequencer (ABI PRISM 3730 DNA Sequencer). RESULTS: The demographic and clinical characteristics did not differ among genotype subgroups. The MCP-1(-2518) GG genotype was significantly associated with DR susceptibility with OR of 1.481 (95 % CI, 1.019-2.153) (P = 0.046). There were no significant differences in the MCP-1(-2518) G allele frequencies in DR compared to non-diabetic retinopathy (DNR) (P > 0.05, OR = 0.841, 95 % CI, 0.705-1.002). The MCP-1(-2518) GG genotype was significantly associated with high-risk PDR susceptibility with OR of 2.656 (95 % CI, 1.222-5.775) (P = 0.014). The MCP-1(-2518) G allele was significantly increased in high-risk PDR patients (P = 0.020, OR = 1.481, 95 % CI, 1.070-2.051) compared with A allele. Genotype and allele frequencies of various DME of the DR patients were compared, but there were no significant associations established (P > 0.05). CONCLUSIONS: It is likely that the MCP-1 c.2518G/G genotype is a susceptibility gene for DR in Chinese type 2 diabetic patients, especially the high-risk PDR. There is no association with DME and c.2518G/G.

Effect of high glucose concentration on VEGF and PEDF expression in cultured retinal Müller cells.

To explore the effect of high glucose concentration on the expression of vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) in the cultured rat retinal Müller cells. Rat Müller cells were cultured and RT-PCR and Western-blot analysis were used to measure the levels of VEGF and PEDF in cultured Müller cells at different high glucose concentrations. Under 10, 20, 30 mmol/L high glucose conditions, the levels of VEGF mRNA and protein increased and the levels of PEDF mRNA and protein decreased. These results suggest that the VEGF and PEDF expression in Müller cells are unbalance under high glucose concentration, which contribute to retinal neovascularization in diabetic retinopathy.