Concentration and activation biresponsive strategy in one analysis system with simultaneous use of G4 structure-specific signal probe and enzyme-catalyzed reaction.

BACKGROUND: Enzymes with critical effects on life systems are regulated by expression and activation to modulate life processes. However, further insights into enzyme functions and mechanisms in various physiological processes are limited to concentration or activation analysis only. Currently, enzyme analysis has received notable attention, particularly simultaneous analysis of their concentration and activation in one system. Herein, N-methyl mesoporphyrin IX (NMM), a specific dye with notable structural selectivity for parallel G-quadruplex nucleic acid enzyme (G4h DNAzyme), is employed for the analysis of its concentration. In addition, the peroxidase activity of G4h DNAzyme is characterized based on G4h DNAzyme-catalyzed decomposition of H2O2 to continuously consume luminol. Accordingly, an increased fluorescence (FL) response of NMM and a decreased FL response of luminol could be simultaneously employed to analyze the concentration and activation of G4h DNAzyme. RESULT: Herein, a novel concentration and activation biresponsive strategy is proposed using a G4h DNAzyme-based model that simultaneously employs a G4h structure-specific signal probe for enzyme concentration analysis and G4h DNAzyme-catalyzed reactions for enzyme activation analysis. Under optimal conditions, the biresponsive strategy can be effectively used for the simultaneous analysis of G4h DNAzyme concentration and activation, with detection limits of 718.7 pM and 233.4 nM respectively, delivering acceptable performances both in cell and in vitro. SIGNIFICANCE: This strategy can not only be applied to concentration and activation analyses of G4h DNAzyme but can also be easily extended to other enzymes by simultaneously combining concentration analysis via target-induced direct reaction and activation analysis via target-induced catalytic reaction, offering deeper insights into various enzymes and enabling their effective implementation in bioanalysis and biochemistry.

Progress of researches on the mechanism of acupuncture treatment for Alzheimer's disease by modulating synaptic plasticity. / é’ˆåˆºè°ƒèŠ‚çªè§¦å¯å¡‘æ€§æ²»ç–—é˜¿å°”èŒ¨æµ·é»˜ç— æœºåˆ¶çš„ç ”ç©¶è¿›å±•.

Alzheimer's disease (AD) is a neurodegenerative disease with high incidence in the elderly population, and the synaptic changes in central neurons are the key pathological feature. The clinical effect of acupuncture and moxibustion in the treatment of AD is positive, and the research on the mechanism of acupuncture intervention of AD from the perspective of central synaptic plasticity regulation has been conducted uninterruptedly. In the present paper, we made a summation about the relevant experimental studies in recent years, and analyzed its mechanisms underlying improvement of AD by regulating synaptic plasticity from 1) repairing synaptic structure (synaptic contact area ï¼»total number of synapses, synaptic surface density, synaptic number densityï¼½, postsynaptic dense zone thickness, synaptic gap width, and interface curvature), 2) improving synaptic transmission efficiency (regulating long-term potentiation and long-term depression), 3) promoting the expression of synapse related proteins (synaptophysin, postsynaptic density protein 95, growth associated protein 43), 4) regulating the expression of neurotransmitters (acetylcholine, monoamines, amino acids, etc.) and receptors (α7 nicotinic acetylcholine receptor, glutaminergic receptor, etc.), and 5) improving the level of neurotrophic factors (brain derived neurotrophic factor, BDNF) and BDNF/SYN/microtubule-associated protein 2 signaling, etc., hoping to provide a reference for future studies.

Study on the Effects of Acupuncture with the "Yizhi Tiaoshen" Acupoint Formula on Blood Oxygen Metabolism and Neural Function in Key Brain Regions of AD Rats.

Purpose: Exploring the effects of acupuncture at the "Yizhi Tiaoshen" acupoint on blood oxygen metabolism and neurological function changes in the brain regions of AD model rats. Methods: The AD model was replicated by intraperitoneal injection of D-galactose combined with bilateral hippocampal CA1 injection of Okadaic acid (OA). Thirty rats with successfully replicated model were selected through Morris water maze experiment and randomly divided into model group, donepezil hydrochloride group, and acupuncture group, with 10 rats in each group. After treatment, fNIRs were used to detect changes in Oxy Hb, Deoxy Hb, and Total Hb in the cerebral cortex of rats in each group, in order to evaluate the neurological function changes in key brain areas. Results: The escape latency of the donepezil hydrochloride group and the acupuncture group was shortened, the number of crossings through the original platform increased, and the duration of stay in the quadrant where the original platform was located was prolonged. Based on fNIRs detection, the main differential channels of blood oxygen metabolism in AD rats were identified as 2-2 and 8-7, corresponding to the prefrontal and parietal lobes, respectively. The concentrations of Oxy Hb and Total Hb were significantly increased in both treatment groups, while the concentration of Deoxy Hb was significantly decreased. Conclusion: Acupuncture with the "Yizhi Tiaoshen" acupoint formula and donepezil hydrochloride can improve the learning and memory function of AD rats, and its mechanism may be related to improving blood oxygen metabolism in the prefrontal and parietal regions and protecting neuronal function.

Effect of acupuncture at the acupoints for Yizhi Tiaoshen on the functional connectivity between the hippocampus and the brain in the patients with Alzheimer's disease. / 针刺"益智调神"ç©´æ–¹å¯¹é˜¿å°”èŒ¨æµ·é»˜ç— æ‚£è€ æµ·é©¬ä¸Žå ¨è„‘åŠŸèƒ½è¿žæŽ¥çš„å½±å“.

OBJECTIVES: To analyze the effect of acupuncture at the acupoints for Yizhi Tiaoshen (benefiting the intelligence and regulating the spirit) on the functional connectivity between the hippocampus and the whole brain in the patients with Alzheimer's disease (AD), and reveal the brain function mechanism of acupuncture in treatment of AD using resting state functional magnetic resonance imaging (rs-fMRI). METHODS: Sixty patients with mild to moderate AD were randomly divided into an acupuncture + medication group (30 cases, 3 cases dropped out) and a western medication group (30 cases, 2 cases dropped out). In the western medication group, the donepezil hydrochloride tablets were administered orally, 2.5 mg to 5 mg each time, once daily; and adjusted to be 10 mg each time after 4 weeks of medication. Besides the therapy as the western medication group, in the acupuncture + medication group, acupuncture was supplemented at the acupoints for Yizhi Tiaoshen, i.e. Baihui (GV 20), Sishencong (EX-HN 1), and bilateral Shenmen (HT 7), Neiguan (PC 6), Zusanli (ST 36), Sanyinjiao (SP 6) and Xuanzhong (GB 39). The needles were retained for 30 min in one treatment, once daily; and 6 treatments were required weekly. The duration of treatment was 6 weeks in each group. The general cognitive function was assessed by the mini-mental state examination (MMSE) and Alzheimer's disease assessment scale-cognitive part (ADAS-Cog) before and after treatment in the two groups. Using the rs-fMRI, the changes in the functional connectivity (FC) of the left hippocampus and the whole brain before and after treatment were analyzed in the patients of the two groups (11 cases in the acupuncture + medication group and 12 cases in the western medication group). RESULTS: After treatment, compared with those before treatment, MMSE scores increased and ADAS-Cog scores decreased in the two groups (P<0.05); MMSE score was higher, while the ADAS-Cog score was lower in the acupuncture + medication group when compared with those in the western medication group (P≤0.05). After treatment, in the western medication group, FC of the left hippocampus was enhanced with the left fusiform gyrus, the inferior frontal gyrus of the left triangular region, the bilateral superior temporal gyrus and the right superior parietal gyrus (P<0.05), while FC was weakened with the left inferior temporal gyrus, the left middle frontal gyrus and the right dorsolateral superior frontal gyrus when compared with that before treatment (P<0.05). After treatment, in the acupuncture + medication group, FC of the left hippocampus was increased with the right gyrus rectus, the left inferior occipital gyrus, the right superior temporal gyrus and the left middle occipital gyrus (P<0.05), and it was declined with the left thalamus (P<0.05) when compared with those before treatment. After treatment, in the acupuncture + medication group, FC of the left hippocampus was strengthened with the bilateral inferior temporal gyrus, the bilateral middle temporal gyrus, the right gyrus rectus, the bilateral superior occipital gyrus, the left lenticular nucleus putamen, the left calcarine fissure and surrounding cortex, the inferior frontal gyrus of the left insulae operculum, the left medial superior frontal gyrus and the right posterior central gyrus (P<0.05) compared with that of the western medication group. CONCLUSIONS: Acupuncture at the acupoints for Yizhi Tiaoshen improves the cognitive function of AD patients, and its main brain functional mechanism is related to intensifying the functional connectivity of the left hippocampus with the default network (inferior temporal gyrus, middle temporal gyrus and superior frontal gyrus, gyrus rectus), as well as with the sensory (posterior central gyrus) and visual (calcarine fissure and surrounding cortex and superior occipital gyrus) brain regions.

Ultrasensitive quantitation of Paraquat based on a small molecule-induced dual-cycle amplification strategy.

Paraquat (PQ) is a typical biotoxic small molecule. Knowledge of how to directly introduce it into cyclic amplification rather than transform it into a secondary target is lacking in current analytical methods. Considering the urgent need for trace pesticide residue detection and the inherent defects of small molecule analysis, a CRISPR/Cas12a-driven small molecule-induced dual-cycle strategy was developed based on the immune competition method. The key to signal amplification is the mutual activation and acceleration between Cycle 1 triggered by the small molecule and Cycle 2 driven by CRISPR/Cas12a. Impressively, small molecules have been successfully incorporated into the dual-cycle strategy, which achieves a low detection limit (3.1 pg/mL) and a wide linear range (from 10 pg/mL to 50 µg/mL). Moreover, the designed biosensor was successfully employed to evaluate the PQ residual level in real samples and showed effective implementation for the bioanalysis of small molecule targets and pesticide residue-related food safety.

Insights of Life Molecules' Dynamic Distribution in Live Cells via Sequence-Structure Bispecific Fluorescent RNA.

Life molecules' distributions in live systems construct the complex dynamic reaction networks, whereas it is still challenging to demonstrate the dynamic distributions of biomolecules in live systems. Herein, we proposed a dynamic analysis strategy via sequence-structure bispecific RNA with state-adjustable molecules to monitor the dynamic concentration and spatiotemporal localization of these biomolecules in live cells based on the new insight of fluorescent RNA (FLRNA) interactions and their mechanism of fluorescence enhancement. Typically, computer-based nucleic acid-molecular docking simulation and molecular theoretical calculation have been proposed to provide a simple and straightforward method for guiding the custom-design of FLRNA. Impressively, a novel FLRNA with sequence and structure bispecific RNA named as a structure-switching aptamer (SSA) was introduced to monitor the real-time concentration and spatiotemporal localization of biomolecules, contributing to a deeper insight of the dynamic monitoring and visualization of biomolecules in live systems.

Three-in-One System Based on Multi-Path Nucleic Acid Amplification for Bioanalysis of Pre-miRNA/miRNA and Dicer Activity.

Today, a lot of attention is being paid to the pre-miRNAs/miRNAs or activity of Dicer due to their important functions in various physiological processes. Especially, the intrinsic relationship among these associated targets is of significant importance for more in-depth research on the mechanism of disease formation and early diagnosis. Herein, a strategy for simultaneous bioanalysis of miRNAs/pre-miRNAs and Dicer enzyme based on the self-designed multi-path nucleic acid amplification technology was proposed. Typically, in the presence of pre-miRNA-155, it can hybridize with Helper to generate a structure with two new toeholds, one of which could react with H1, H2, and H3, performing a modified CHA reaction with obvious fluorescence responses of FAM, and another of which could hybridize with H4, H5, and H6 to construct the [H4-H5-H6]n DNA nanosphere with obvious fluorescence responses of Cy5. Similarly, miRNA-155 could just hybridize with H1, H2, and H3 to generate the same modified CHA reaction with obvious fluorescence responses of FAM. Due to the successful multi-path nucleic acid amplification, the proposed bioanalysis strategy could be successfully employed for miRNA-155 and pre-miRNA-155 analysis in the range from 500 pM to 100 nM and 1 to 300 nM, respectively. The proposed strategy could be applied to explore another inter-related nucleic acid relationship also, providing great potential in bioanalysis of various nucleic acids.

Endoscopic management of delayed bleeding after polypectomy of small colorectal polyps: two or more clips may be safe.

Background: The resection of small colorectal polyps (≤10 mm) is routine for endoscopists. However, the management of one of its main complications, namely delayed (within 14 days) postpolypectomy bleeding (DPPB), has not been clearly demonstrated. We aimed to assess the role of coloscopy in the management of DPPB from small colorectal polyps and identify the associated factors for initial hemostatic success. Methods: We conducted a retrospective study of 69 patients who developed DPPB after the removal of colorectal polyps of ≤10 mm and underwent hemostatic colonoscopy at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between April 2013 and June 2021. Demographics, clinical variables, and colonoscopic features were collected independently. We applied univariate and multivariate analyses to assess factors associated with initial hemostatic success. Results: General colonoscopy without oral bowel preparation was successfully performed in all the patients, with a median duration of 23.9 (12.5-37.9) minutes. Among 69 patients, 62 (89.9%) achieved hemostasis after initial hemostatic colonoscopy and 7 (10.1%) rebled 2.7 ± 1.1 days after initial colonoscopic hemostasis and had rebleeding successfully controlled by one additional colonoscopy. No colonoscopy-related adverse events occurred. Multivariate analysis showed that management with at least two clips was the only independent prognostic factor for initial hemostatic success (odds ratio, 0.17; 95% confidence interval, 0.03-0.91; P = 0.04). All the patients who had at least two clips placed at the initial hemostatic colonoscopy required no further hemostatic intervention. Conclusions: Colonoscopy is a safe, effective, and not too time-consuming approach for the management of patients with DPPB of small colorectal polyps and management with the placement of at least two hemoclips may be beneficial.

Proximity hybridization-induced competitive rolling circle amplification to construct fluorescent dual-sensor for simultaneous evaluation of glycated and total hemoglobin.

The glycated hemoglobin (HbA1c) level, defined as the ratio of HbA1c to total hemoglobin (tHb), has been considered as a standard index for diabetes mellitus diagnosis, avoiding any short-term fluctuation of the blood glucose level. However, it is still a key challenge that some complicated separation procedures are required to detect HbA1c and tHb in a single experiment. Herein, we developed a dual-sensing fluorescent assay for HbA1c and tHb based on proximity hybridization-induced rolling circle amplification (RCA) and T7 exonuclease aided signal cycle to calculate the HbAlc level in one single experiment. Typically, four DNA-tagged probes were used for immunoreactions of anti-HbA1c antibodies (Ab1) and anti-Hb antibodies (Ab2) with HbA1c and Hb, respectively. The RCA1 and RCA2 were induced by the complexes of assistant DNAs and the products of proximity hybridization with anti-HbA1c-DNA1 (2) and anti-Hb-DNA3 (4), respectively. Meanwhile, the tHb in solution could prevent the existing RCA2 based on its competing with Hb-DNA3 for Ab2-DNA4. Thus, RCA1 and RCA2 routes create "signal-on" and "signal-off" readouts, respectively. After the hybridization of signal probes and RCA products, the quenched fluorescence was recovered by the digestion of T7 exonuclease. Under optimized conditions, the method displayed high sensitivity with a limit of detection 2.17 ng/mL and 33.4 ng/mL for HbA1c and tHb, respectively, and the real sample analysis results were found to match well with the theoretical data, holding feasibility for rapid, homogeneous, and easy HbA1c level evaluation and great promise as a potential alternative tool to analyze HbA1c level clinically.

High-risk human papilloma virus infection and cervical neoplasm in female inflammatory bowel disease patients: a cross-sectional study.

BACKGROUND AND AIM: This cross-sectional study investigated the prevalence and risk factors of high-risk human papilloma virus (HPV) infection, especially types 16 and 18, and cervical neoplasia in female Inflammatory bowel disease (IBD) patients. METHODS: From July 2014 to January 2017, sexually active, female, Chinese IBD patients (21-60 years) and age-matched controls underwent cervical ThinPrep cytology testing (TCT) and high-risk HPV-DNA detection, and completed questionnaires about awareness of cervical cancer and HPV. Cervical dysplasia was categorized as cervical intraepithelial neoplasia (CIN) 1, 2 and 3. RESULTS: Of 124 IBD patients (30 ulcerative colitis and 94 Crohn's disease), 17 (13.7%) had high-risk HPV among whom 9 (7.3%) had HPV 16/18 infection and 4 (3.2%) had cervical CIN (3 CIN 3, 1 CIN 1) by pathology. Among 372 controls, 33 (8.9%) had high-risk HPV and only 1 (0.3%) had HPV 16 infection. Cervical TCT detected atypical squamous cells of unknown significance in one control; no control had CIN. The HPV 16/18 infection rate and CIN prevalence were significantly higher in IBD patients than controls (both P < 0.001). The HPV-infection rate was higher in patients administered methotrexate [P = 0.005, odds ratio (95% confidence interval) 4.76 (1.471-15.402)] or more than two immunosuppressants [P = 0.013, odds ratio (95% confidence interval) 3.64 (1.255-10.562)]. Thiopurine, steroid, infliximab and disease behavior/location were not associated with HPV infection. Only 29.3% of patients had undergone cervical-cancer screening. Awareness of HPV infection and HPV-related cervical cancer was poor (28.2%). CONCLUSIONS: Female IBD patients are at increased risk of high-risk HPV infection and cervical neoplasia, which may be associated with immunosuppressants. Education and routine follow-up with HPV-DNA testing and TCT are recommended, especially in female Chinese IBD patients.