Cell competition for neuron-derived trophic factor controls the turnover and lifespan of microglia.

Microglia are brain-resident macrophages capable of long-term maintenance through self-renewal. Yet the mechanism governing the turnover and lifespan of microglia remains unknown. In zebrafish, microglia arise from two sources, rostral blood island (RBI) and aorta-gonad-mesonephros (AGM). The RBI-derived microglia are born early but have a short lifespan and diminish in adulthood, while the AGM-derived microglia emerge later and are capable of long-term maintenance in adulthood. Here, we show that the attenuation of RBI microglia is due to their less competitiveness for neuron-derived interleukin-34 (Il34) caused by age-dependent decline of colony-stimulating factor-1 receptor a (csf1ra). Alterations of Il34/Csf1ra levels and removal of AGM microglia revamp the proportion and lifespan of RBI microglia. The csf1ra/CSF1R expression in zebrafish AGM-derived microglia and murine adult microglia also undergo age-dependent decline, leading to the elimination of aged microglia. Our study reveals cell competition as a general mechanism controlling the turnover and lifespan of microglia.

Effect of controlling nitrogen and phosphorus release from sediment using a biological aluminum-based P-inactivation agent (BA-PIA).

A biological aluminum-based P-inactivation agent (BA-PIA) has been developed and demonstrated to effectively remove nitrogen and phosphorus; however, whether it can control the release of nitrogen and phosphorus in sediment still needs study. This study aimed to examine the effect of BA-PIA on controlling sediment nitrogen and phosphorus release. BA-PIA was prepared by artificial aeration. The use of BA-PIA in controlling nitrogen and phosphorus release was studied using water and sediment from a landscape lake in static simulation experiments. The sediment microbial community was analyzed using high-throughput sequencing. Static simulation showed that the reduction rates of total nitrogen (TN) and total phosphorus (TP) by BA-PIA were 66.8 ± 1.46% and 96.0 ± 0.98%, respectively. In addition, capping of BA-PIA promotes the conversion of easily released nitrogen (free nitrogen) in the sediment to stable nitrogen (acid-hydrolyzable nitrogen). The content of weakly adsorbed phosphorus and iron-adsorbed phosphorus in the sediment was reduced. The relative abundance of nitrifying bacteria, denitrifying bacteria, and microorganisms carrying phosphatase genes (such as Actinobacteria) in the sediment increased by 109.78%. The capping of BA-PIA not only effectively removed the nitrogen and phosphorus in water but greatly reduced the risk of nitrogen and phosphorus release from sediment. BA-PIA was able to make up for the deficiency of the aluminum-based phosphorus-locking agent (Al-PIA) that only removes phosphorus, giving it improved application prospects.

Rapid detection of heterocyclic aromatic amines in cakes by digital imaging colorimetry based on magnetic solid phase extraction with sulfonated hyper-cross-linked polymers.

To improve the hydrophobicity and poor separability of hyper-cross-linked polymers (HCPs) in extraction, a porous magnetic adsorbent (Fe3O4@SHCP) was constructed by facile post-modification to introduce sulfonic acid groups and magnetic nanoparticles for the magnetic solid-phase extraction of heterocyclic aromatic amines (HAAs). Owing to the double extraction mechanism adopted by Fe3O4@SHCP, it has a high extraction efficiency for HAAs. Coupled with high-performance liquid chromatography (HPLC), 5 HAAs in baked cakes were detected at one time. Under optimal extraction conditions, the enrichment factor of HAAs was up to 952-986, with LODs at 0.05-0.3 ng·g-1. Based on the HPLC method, novel digital imaging colorimetry (DIC) was developed to accurately and rapidly monitor HAAs in cakes. Additionally, the established DIC method has been used to successfully evaluate the effect of baking temperature and duration on HAAs in baked cakes.

Synchronous Construction of Hierarchical Porosity and Thiol Functionalization in COFs for Selective Extraction of Cationic Dyes in Water Samples.

Pore size and functionalization are two critical factors for covalent organic frameworks (COFs) as effective adsorbents. However, due to the low crystallinity of COFs, it is a grand challenge to accomplish pore diameter adjustment and functionalization at the same time. In this work, we developed a simple and ingenious strategy, cutting off linkage, to synchronously construct hierarchical porosity and modify thiol groups in COFs under mild conditions. The hybrid COFs containing disulfide bonds were designed and synthesized, and then the disulfide bonds were cleaved by glutathione, resulting in the formation of thiol groups as well as the increase in pore size caused by skeleton defects. The pore diameter of thiol-functionalized hierarchical porous COFs (denoted as HP-TpEDA-SH) was concentrated at 2.6 and 3.5 nm. Thanks to the electrostatic attraction of thiol groups to cationic dyes and the higher number of available adsorption sites, the maximum extraction amounts of methylene blue (MB), malachite green (MG), and crystal violet (CV) by HP-TpEDA-SH were 2.6, 2.1, and 3.3 times those of microporous COFs under optimal extraction conditions, respectively. The proposed analytical method (solid-phase extraction-high-performance liquid chromatography/ultraviolet (SPE-HPLC/UV)) with HP-TpEDA-SH as the adsorbent showed low detection limits of 1.3, 0.13, and 0.12 µg·L-1 for MB, MG, and CV, respectively. The recoveries of three spiked water samples ranged from 81.5 to 113.8%, with relative standard deviations (RSDs) less than 9.7%. This work not only opened a new avenue for the preparation of functionalized hierarchical porous COFs but also established an effective method for detecting trace cationic dyes in fishery water.

Preparation of magnetic mesoporous metal-phenolic coordination spheres for extraction of crystal violet and leuco-metabolites in fish.

To address the undesirably low porosity of phenolic resin, a new material termed magnetic mesoporous metal-phenolic coordination spheres (Fe3O4@Co-TA) was synthesized by chelating tannic acid (TA) with metal ions. Fe3O4@Co-TA was characterized by transmission electron microscopy, scanning electron microscopy, hysteresis loop (B-H) analysis, Fourier-transform infrared spectroscopy, and N2 adsorption-desorption. The results indicated that the new material comprises mesopores (2 nm and 3 nm) and exhibits a good magnetic response (44 emu/g). Combined with high-performance liquid chromatography (HPLC), a novel method for the detection of crystal violet (CV) and leucocrystal violet (LCV) by magnetic solid-phase extraction was established. Under the optimal extraction conditions, the linear ranges of CV and LCV detection were 0.2‒60 µg/L and 0.04‒40 µg/L, the detection limits were 0.04 µg/L and 0.008 µg/L, and the enrichment factors were 435 and 460, respectively. Fe3O4@Co-TA was reused ten times without significant reduction of the extraction ability. This method was successfully used for the detection of CV and LCV in fish samples, providing an effective technique for food safety monitoring and quality control.

Paeoniflorin Improved Constipation in the Loperamide-Induced Rat Model via TGR5/TRPA1 Signaling-Mediated 5-Hydroxytryptamine Secretion.

Slow transit constipation (STC) is a common type of constipation with a high incidence rate and a large number of patients. We aimed to investigate the therapeutic effects and potential mechanism of paeoniflorin (PAE) on loperamide-induced Sprague Dawley (SD) rat constipation models. Rats with loperamide-induced constipation were orally administered different concentrations of PAE (10, 20, or 40 mg/kg). In vitro, enterochromaffin (EC)-like RIN-14B cells were treated with 20, 40, or 80 µg/ml PAE. We found that PAE treatment significantly improved the symptoms of constipation and increased the intestinal transit rate. Hematoxylin and eosin (H&E) staining showed that PAE alleviated colonic tissue pathological damage. Besides, our results implied that PAE concentration-dependently promoted the content of 5-hydroxytryptamine (5-HT) catalyzed by tryptophan hydroxylase (Tph)-1 in the serum of loperamide-induced rats and in RIN-14B cells. Western blot and immunofluorescence (IF) stain indicated that PAE also promoted the expression of G protein-coupled BA receptor 1 (TGR5), transient receptor potential ankyrin 1 (TRPA1), phospholipase C (PLC)-γ1, and phosphatidylinositol 4,5-bisphosphate (PIP2) in vivo and in vitro. RIN-14B cells were cotreated with a TGR5 inhibitor (SBI-115) to explore the mechanism of PAE in regulating the 5-HT secretion. We observed inhibition of TGR5 reversed the increase of 5-HT secretion induced by PAE in RIN-14B cells. We provided evidence that PAE could promote 5-HT release from EC cells and improve constipation by activating the TRPA1 channel and PLC-γ1/PIP2 signaling. Thus, PAE may provide therapeutic effects for patients with STC.

[Preparation of magnetic metal-organic frameworks-polydopamine for extraction and detection of cationic dyes from water samples in a fishery].

The catechol group of dopamine (DA) can chelate with the metal ion in the crystal of molecular organic frameworks (MOFs). Based on this principle, a magnetic metal polydopamine (PDA) framework (Fe3O4@Z67D) was prepared using ZIF-67 as the template, which was etched by DA, followed by polymerization of the DA monomers to form a PDA coating with a porous structure. The morphology, structure, and properties of the material were determined by various characterization methods. Fe3O4@Z67D was used as an adsorbent, and a magnetic solid-phase extraction/high-performance liquid chromatography method for the determination of two cationic dyes, methylene blue (MB) and crystal violet (CV), was established. Under the optimized extraction and detection conditions, the linear ranges for MB and CV were 0.5-200 µg/L and 0.01-50 µg/L, respectively, and the corresponding detection limits were 0.04 µg/L and 0.008 µg/L. The experimental results showed that the enrichment factors of Fe3O4@Z67D for the two dyes were 777 and 688, respectively. The extraction performance was largely unaffected even after the new material was reused 10 times. The method was applied successfully for the adsorption and detection of the above mentioned two dyes in fishpond water. The spiking recoveries of the two cationic dyes ranged from 82.0% to 109.0%, and the RSD was lower than 2.9%.

Tenofovir versus entecavir in lowering the risk of hepatocellular carcinoma development in patients with chronic hepatitis B: a critical systematic review and meta-analysis.

BACKGROUND: Controversy exists on whether tenofovir disoproxil fumarate (TDF) is superior to entecavir (ETV) in lowering the risk of hepatocellular carcinoma (HCC) development. This meta-analysis was performed to clarify this issue with critical clinical and methodological considerations. METHODS: PubMed, EMBASE, and Cochrane Library were searched from inception to Oct 28, 2019. Randomized control trials and observational studies reporting the impact of TDF and ETV on the risk of HCC in patients with chronic hepatitis B (CHB) were eligible. Risk ratios (RRs) calculated with cumulative incidence rate and/or annual incidence rate, or hazard ratio (HR) were pooled using random-effect models. Subgroup analyses were performed to assess the potential impact of between-study level and within-study level factors. RESULTS: A total of 32 studies with 78,136 CHB patients were included. Overall cumulative incidence rate of HCC was lower in TDF group than ETV group (3.07% vs. 5.25%; RR 0.55; 95% CI 0.42-0.72). However, this difference was not statistically significant in pooled results of hazard ratio (HR 0.87; 95% CI 0.73-1.04) and RR calculated with annual incidence rate (RR 0.88; 95% CI 0.67-1.16). Potential confounding factors at between-study level included prior nucleos(t)ide usage, disease stage at baseline and region of study. More importantly, at within-study level, disparity in follow-up duration between TDF and ETV groups may impact the result, usually favoring a treatment with shorter follow-up duration. CONCLUSIONS: Compared with ETV, TDF treatment tended to have a lower overall cumulative incidence rate of HCC. However, disparity in follow-up duration may be a key factor to influence the result.

[Percutaneous endoscpic lumbar discectomy for the treatment of upper lumbar disc herniation].

OBJECTIVE: To evaluate the preliminary clinical outcomes of percutaneous endoscopic lumbar discectomy (PELD) for patient with upper lumbar disc herniation and failing to respond to conservative treatment. METHODS: From December 2008 to June 2011, 12 patients with upper lumbar disc herniation and failing to respond to conservative treatment were treated, including 8 males and 4 females, aged from 28 to 82 years old (averaged, 50.67 years old). Duration of upper lumbar disc herniation was 3 to 10 months, with an average of 5.75 months. MRI exam revealed 12 "degeneration discs" low in signal on T2 image, including 1 discs of T12L1, 1 of L1,2, 3 of L2,3 and 7 of L3,4. Discography showed positive response, fluoroscopy confirmed annulus fibrosus tears of posterior intervertebral disc in 12 discs. PELD was performed. Visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated before operation and after operation. The clinical outcome was determined by modified Macnab criteria at the final follow-up. RESULTS: The average operation time of each patient was 1.45 h (ranged, 1.0 to 2.5 h), and the mean length of postoperative hospital stay was 5.83 days (ranged,4 to 9 days). There was no happening in ruptured meninges and nerve damage. Twelve patients were followed up,and the duration ranged from 1 to 12 months (averaged, 5.5 months). The VAS score decreased from preoperative 8.00 +/- 1.21 to postoperative 1.92 +/- 0.79 (P < 0.01). The ODI decreased from preoperative (78.81 +/- 13.65)% to the final follow-up (16.19 +/- 3.52)% (P < 0.01). According to the modified Macnab criteria, 3 patients got an excellent result, 8 good, 1 fair. CONCLUSION: PELD is effective in treating patient with upper lumbar disc herniation failing to respond to conservative treatment.