The predictive value of MiR-221 in cancer chemoresistance: a systematic review and meta-analysis

BACKGROUND

Many studies have reported that microRNA-221 (miR-221) is abnormally expressed in various cancers, and there has not been a study to systematically analyze the association between miR-221 and chemoresistance in different cancers.

METHODS

We systematically searched PubMed, Web of Science, Ovid, and Cochrane for relevant studies. The pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate.

RESULTS

A total of 30 studies with 1670 patients were enrolled in our study. Thirteen cancer types have been studied, and traditional chemotherapy, targeted drugs, endocrine therapy, chemoradiotherapy, and other treatments were used. High miR-221 expression was associated with poor chemotherapy response in most studies, and the meta-analysis confirmed this result (OR = 3.64, 95%CI: 1.73-7.62, p = 0.001). Besides, the higher level of miR-221 was related to shorter overall survival (OS) (HR = 2.16, 95%CI: 1.47-3.16, p < 0.001) and progression-free survival (PFS) (HR = 1.81, 95%CI: 1.51-2.16, p < 0.001) in patients after chemotherapy.

CONCLUSION

Our results highlight that high miR-221 expression has possible associations with chemoresistance and poor prognosis in multiple cancers. Further studies are needed to discover the molecular mechanisms underlying these associations to provide a solid evidence base for it being used as biomarkers of response to chemotherapeutic interventions in cancer.

Brine available two-dimensional nano-architectonics of fluorescent probe based on phosphate doped ZIF-L for detection of Fe3

Herein, we propose a simple and effective strategy for designing a zeolitic imidazolate frameworks (ZIFs) fluorescent probe with a two-dimensional leaf-like structure. By doping ZIF-L with phosphate, we developed a fluorescent probe for iron (Fe3+) in systems with high salinity. The fluorescence of P-ZIF-L was quenched effectively with the presence of Fe3+. The physicochemical structure, surface morphology, selectivity, stability and composition of the probe were investigated. Under optimized conditions, the fluorescent probe had a detection limit of 0.5 μM. Furthermore, the results that the probe exhibited desirable salt-tolerance and was suitable for determination of Fe3+ in brine water samples with satisfactory results.

Sequence Variation of Candida albicans Sap2 Enhances Fungal Pathogenicity via Complement Evasion and Macrophage M2-Like Phenotype Induction

Candida albicans (C. albicans) is an opportunistic pathogen increasingly causing candidiasis worldwide. This study aims to investigate the pattern of systemic immune responses triggered by C. albicans with disease associated variation of Sap2, identifying the novel evasion strategies utilized by clinical isolates. Specifically, a variation in clinical isolates is identified at nucleotide position 817 (G to T). This homozygous variation causes the 273rd amino acid exchange from valine to leucine, close to the proteolytic activation center of Sap2. The mutant (Sap2-273L) generated from SC5314 (Sap2-273V) background carrying the V273L variation within Sap2 displays higher pathogenicity. In comparison to mice infected with Sap2-273V strain, mice infected with Sap2-273L exhibit less complement activation indicated by less serum C3a generation and weaker C3b deposition in the kidney. This inhibitory effect is mainly achieved by Sap2_273L -mediated stronger degradation of C3 and C3b. Furthermore, mice infected with Sap2-273L strain exhibit more macrophage phenotype switching from M0 to M2-like and more TGF-β release which further influences T cell responses, generating an immunosuppressed cellular microenvironment characterized by more Tregs and exhausted T cell formation. In summary, the disease-associated sequence variation of Sap2 enhances pathogenicity by complement evasion and M2-like phenotype switching, promoting a more efficient immunosuppressed microenvironment.

Simultaneous detection of multi-component greenhouse gases based on an all-fibered near-infrared single-channel frequency-division multiplexing wavelength-modulated laser heterodyne radiometer

The performance of an all fibered near-infrared (NIR) single-channel frequency-division multiplexing wavelength-modulated laser heterodyne radiometer (FDM WM-LHR) is demonstrated in ground-based solar occultation mode. The system modulates the laser through the high-frequency signal output by the lock-in amplifier to replace the traditional chopper modulation, making it more stable and compact. Moreover, personal computers are used to simultaneously control the operating current of two distributed feedback (DFB) lasers through a general purpose interface bus-universal serial bus (GPIB-USB), thereby controlling the central wavelength of the laser at 1602.88 and 1653.727 nm, which serve as the absorption lines for the local oscillator detection of the two main greenhouse gases: CO₂ and CH₄. Firstly, the performance of traditional laser heterodyne radiometer (LHR) and the wavelength-modulated laser heterodyne radiometer (WM-LHR) are compared. The results reveal that both the radiometers have an optimized 2f signal when the modulation amplitude m = 2.2. In the actual measurement, 0.25 V and 0.21 V are selected as the modulation amplitude of the laser for the detection of CH₄ and CO₂. Under the same experimental parameters, at 1602.88 nm, the signal-to-noise ratio (SNR) for the 2f signal of CO₂ in the WM-LHR system is 500.24, while that for the direct absorption signal (DAS) of CO₂ in the traditional LHR system is 337.94. At 1653.727 nm, the SNR for the 2f signal in the WM-LHR system and the DAS of CH₄ in the traditional LHR system are 512.04 and 389.58, respectively. Obviously, the SNR for the WM-LHR system is greatly improved. Finally, the application of frequency-division multiplexing (FDM) technology in the WM-LHR system is discussed. The modulation frequency of the two lasers should be appropriately selected to avoid interference between the signals. Overall, the results show that the FDM WM-LHR system can not only detect multiple gases simultaneously but also reduce the implementation cost of the ground-based radiometer. In addition, this study provides useful insights on planetary atmosphere exploration.

A national, multicenter, retrospective study of Castleman disease in China implementing CDCN criteria

Background

Castleman disease (CD) is a group of rare and heterogenous lymphoproliferative disorders including unicentric CD (UCD), human herpesvirus-8(HHV-8)-associated multicentric CD (HHV8-MCD), and HHV-8-negative/idiopathic multicentric CD (iMCD). Knowledge of CD mainly comes from case series or retrospective studies, but the inclusion criteria of these studies vary because the Castleman Disease Collaborative Network (CDCN) diagnostic criteria for iMCD and UCD were not available until 2017 and 2020, respectively. Further, these criteria and guidelines have not been systematically evaluated.

Methods

In this national, multicenter, retrospective study implementing CDCN criteria, we enrolled 1634 CD patients (UCD, n = 903; MCD, n = 731) from 2000 to 2021 at 40 Chinese institutions to depict clinical features, treatment options, and prognostic factors of CD.

Findings

Among UCD, there were 162 (17.9%) patients with an MCD-like inflammatory state. Among MCD, there were 12 HHV8-MCD patients and 719 HHV-8-negative MCD patients, which included 139 asymptomatic MCD (aMCD) and 580 iMCD meeting clinical criteria. Of 580 iMCD patients, 41 (7.1%) met iMCD-TAFRO criteria, the others were iMCD-NOS. iMCD-NOS were further divided into iMCD-IPL (n = 97) and iMCD-NOS without IPL (n = 442). Among iMCD patients with first-line treatment data, a trend from pulse combination chemotherapy toward continuous treatment was observed. Survival analysis revealed significant differences between subtypes and severe iMCD (HR = 3.747; 95% CI: 2.112-6.649, p < 0.001) had worse outcome.

Interpretation

This study depicts a broad picture of CD, treatment options and survival information in China and validates the association between the CDCN's definition of severe iMCD and worse outcomes, requiring more intensive treatment.

Fundings

Beijing Municipal Commission of Science and Technology, CAMS Innovation Fund and National High Level Hospital Clinical Research Funding.

A ratiometric fluorescence platform for lead ion detection via RNA cleavage-inhibited self-assembly of three-arm branched junction

Heavy metal pollution can pose a threat to food safety and human health, and accurate quantification of heavy metal ions is a vital requirement. Emerging DNA nanostructures-based biosensors offer attractive tools toward ultra-sensitive or rapid analysis of heavy metal ions. However, the problems including complex design, severe reaction conditions and undesirable reliability are inevitable obstacle in advancing their extension and application. Herein, a ratiometric fluorescent platform was established for monitoring lead ion (Pb²⁺) in food based on dual Förster resonance energy transfer (FRET) and RNA cleavage-inhibited self-assembly of three-arm branched junction (TBJ). GR-5 DNAzyme was employed for Pb²⁺ recognition, and enzyme-free amplification technique catalytic hairpin assembly (CHA) served to form FRET probes-carried TBJ. The substrate strand (S) of DNAzyme triggered the generation of CHA-TBJ, and Pb²⁺-responsive cleavage of S hindered the assembly of CHA-TBJ, causing opposite changes in the FRET states of FAM/BHQ1 and ROX/BHQ2 pairs. The fluorescence responses were recorded through synchronous fluorescence spectrometry to indicate Pb²⁺ concentration, allowing sensitive and reliable identification of Pb²⁺ in the linear range of 0.05-5 ng mL^-1 with the detection limit of 0.03 ng mL^-1. The Pb²⁺ detection can be achieved under conventional reaction conditions, simple mixing procedures and one-step measurement operation. The approach can afford excellent specificity for Pb²⁺ against competing metal ions, and can be applied to analyze Pb²⁺ in tea samples with satisfactory results. This facile fluorescence platform shows a capable method for Pb²⁺ detection, and provides new avenue in the development of ratiometric approaches and DNAzyme strategies for monitoring heavy metal pollution, facilitating the transformation of DNAzyme-based biosensors for food safety control.

[The regulation of APGAT4 on the growth and lenvatinib resistance of hepatocellular carcinoma]

Objective: To investigate the effect of 1-acyl-sn-glycerol-3-phosphate acyltransferaseδ (APGAT4) on the growth and lenvatinib resistance of hepatocellular carcinoma (HCC), and provide novel targets for HCC treatment. Methods: Using the bioinformatics methods to screen out upregulated genes in lenvatinib resistant cell lines from GEO dataset and survival related genes from TCGA dataset. Immumohistochemical staining was used to detect the expression AGPAT4 in HCC tissues, and its correlation with patients' survival. CCK8, EdU, cell cycle, and cell apoptosis assays were used to investigate the impact of role AGPAT4 on the proliferation and lenvatinib reistance of HCC cells. AGPAT4 stable knockdown cell line and subcutaneous nude mouse model were established to test the therapeutic effects of Lenvatinib. Analysis of variance was used to compare the differences between data sets. Results: APGAT4 was the common factor that predicted poor survival and Lenvatinib resistance. The mRNA and protein levels of APGAT4 were significantly upregulated in HCC tissues compared to the para-tumor tissues (P < 0.05). Using siRNA could significantly knocked down the mRNA and protein expression of APGAT4 in HCC cell lines Hep3B and HCCLM3. Compared with the control group, the proliferation ability of HCC cell lines (Hep3B and HCCLM3) in APGAT4 knockdown group was significantly inhibited, and the cell cycle was arrested in G2/M phase (P < 0.05). In addition, compared to the control group, HCC cell lines (Hep3B and HCCLM3) in APGAT4 knockdown group showed significant decrease in the Lenvatinib half maximal inhibitory concentration, and were more sensitive to lenvatinib-induced apoptosis (P < 0.05). In HCC subcutaneous nude mouse model, compared to the control group, the growth of tumor in APGAT4 knockdown group was significantly suppressed, and more apoptosis cells were induced (P < 0.05). Conclusion: APGAT4 promotes the growth and Lenvatinib resistance of HCC, which is a potential target for HCC treatment. Targeting APGAT4 treatment is conducive to inhibit the growth and Lenvatinib resistance of HCC.

[Cross-sectional study on the use of masks among occupational groups with high-risk positions for overseas import and pollution transmission]

Objective: To investigate the wearing of masks and the knowledge of masks among high-risk positions for overseas import and pollution transmission. Methods: From May 14 to 17, 2022, a convenient sampling method was used to conduct an online survey among 963 workers in high-risk positions for overseas import and pollution transmission in Beijing. The behaviors of individual use and wearing masks, the distribution and supervision of the unit, the knowledge of personal mask protection and the subjective feelings of wearing masks were analyzed. The χ(2) test and logistic regression model were used to analyze the influencing factors of the correct selection of masks. Results: The majority of the workers in high-risk positions for overseas import and pollution transmission were male (86.0%, 828/963), age concentration in 18-44 years old (68.2%, 657/963), and the majority of them had college or bachelor degrees (49.4%, 476/963). 79.4%(765/963) of the workers chose the right type of masks, female, 45-59 years old and high school education or above were the risk factors for correct selection of masks (P <0.05). Workers had good behaviors such as wearing/removing masks, but only 10.5% (101/963) could correctly rank the protective effect of different masks. 98.4% (948/963) of the workers believed that their work units had provided masks to their employees, and 99.1% (954/963) and 98.2%(946/963) of them had organized training and supervision on the use of masks, respectively. 47.4%(456/963) of the workers were uncomfortable while wearing masks. Conclusion: The overall selection and use of masks among occupational groups in high-risk positions for overseas import and pollution transmission in China need to be further standardized. It is necessary to strengthen supervision and inspection on the use of masks among occupational groups, and take improvement measures to improve the comfort of wearing masks.

ACSL4: a Double-edged Sword Target in Multiple Myeloma, Promotes Cell Proliferation and Sensitizes Cell to Ferroptosis

Overactive fatty acid metabolism is usually found in hematological malignancies including multiple myeloma (MM), but the underlying mechanisms remain unclear. Here, we reveal that acyl-CoA synthetase long-chain family member 4 (ACSL4) is abnormally over-expressed in MM cell lines and MM patients compared to healthy donors. Knockdown of ACSL4 inhibited MM cell proliferation and reduced fatty acid levels possibly by regulating lipid metabolism genes including c-Myc and sterol regulatory element binding proteins (SREBPs). As a propellent in ferroptosis, ACSL4 also determines the sensitivity of MM cells to ferroptosis inducer RSL3. Knockdown of ACSL4 rendered MM cells resistance to ferroptosis. Our findings suggest that ACSL4 is a double-edged sword target in MM. Based on the high expression of ACSL4, ferroptosis induction represents a promising therapeutic strategy for MM.

Characteristics and Controlling Role in Hydrocarbon Accumulation of Strike-Slip Faults in the Maigaiti Slope

The Maigaiti Slope is a significant oil-gas-bearing field in the Tarim Basin. Based on 3D and 2D seismic data, systematic interpretation, stage sorting and genetic analysis of strike-slip faults in the Maigaiti Slope were carried out for the first time. The relationship between strike-slip faults and hydrocarbon accumulation was studied in combination with the fine dissection of hydrocarbon reservoirs. The study suggested that: (1) Staging and segmentation characteristics of strike-slip faults are evidently presented in the Maigaiti Slope. According to active periods, strike-slip faults can be divided into early Caledonian period, late Caledonian period, Hercynian period, and Himalayan period. According to plane distribution characteristics, strike-slip faults can be divided into the west Maigaiti Segment, mid-Maigaiti Segment, Madong Segment, and Bachu Segment. The main active periods and plane distribution of strike-slip faults in different sections are remarkably different. This analysis suggests that it is the response to multi-period and multi-directional tectonic movements, which are primarily dominated by the migration and evolution of the Hetian paleo-uplifts. (2) The coupling relationship between the active period of strike-slip faults and the trap forming period is the key to hydrocarbon accumulation in the Carboniferous–Ordovician, which determines the petroleum properties and enrichment horizon of the Cambrian post-salt system; medium-heavy oil is in the Caledonian period, light oil in the Indosinian period, and dry gas in the Himalayan period.

Self-Assembled Nanodelivery System with Rapamycin and Curcumin for Combined Photo-Chemotherapy of Breast Cancer

Nanodelivery systems combining photothermal therapy (PTT) and chemotherapy (CT), have been widely used to improve the efficacy and biosafety of chemotherapeutic agents in cancer. In this work, we constructed a self-assembled nanodelivery system, formed by the assembling of photosensitizer (IR820), rapamycin (RAPA), and curcumin (CUR) into IR820-RAPA/CUR NPs, to realize photothermal therapy and chemotherapy for breast cancer. The IR820-RAPA/CUR NPs displayed a regular sphere, with a narrow particle size distribution, a high drug loading capacity, and good stability and pH response. Compared with free RAPA or free CUR, the nanoparticles showed a superior inhibitory effect on 4T1 cells in vitro. The IR820-RAPA/CUR NP treatment displayed an enhanced inhibitory effect on tumor growth in 4T1 tumor-bearing mice, compared to free drugs in vivo. In addition, PTT could provide mild hyperthermia (46.0 °C) for 4T1 tumor-bearing mice, and basically achieve tumor ablation, which is beneficial to improving the efficacy of chemotherapeutic drugs and avoiding damage to the surrounding normal tissue. The self-assembled nanodelivery system provides a promising strategy for coordinating photothermal therapy and chemotherapy to treat breast cancer.

Research progress of traditional Chinese medicine compound "Xiaochaihu Decoction" in the treatment of depression

Depression is a common psychiatric disorder under the category of depression syndrome in Traditional Chinese Medicine (TCM) theory. Meanwhile, Xiaochaihu Decoction is a classical TCM formulation regulating Qi, resolving and dissipating stagnation. Clinically, the formulation has long been adopted to treat Shaoyang stagnation syndrome for depression syndrome. In this review, potential targets of action and the corresponding pathways of Xiaochaihu Decoction are explored for depression treatment via network pharmacology. The article also systematically summarizes the active components and pharmacological mechanisms of seven Chinese herbal medicine components in Xiaochaihu Decoction and guides the future study direction of Xiaochaihu Decoction, which may serve a promising treatment for depression.

A prognostication system based on clinical parameters and [18F]-FDG PET/CT in patients with newly diagnosed multiple myeloma

PURPOSE

This study aimed to assess prognosis of patients with newly diagnosed multiple myeloma (NDMM) by combining [¹⁸F]-FDG positron emission tomography (PET)/CT parameters and clinical indices.

METHODS

Clinical data and PET/CT parameters of 133 NDMM patients were retrospectively analyzed for associations between clinical indices and PET/CT parameters. Independent predictors of progression-free survival (PFS) and overall survival (OS) were determined. A new prognostic prediction system (NPPS) was constructed based on our findings. Prediction effectiveness was compared among the NPPS, International Staging System (ISS), Revised ISS (R-ISS), and R2-ISS.

RESULTS

Prevalence of elevated β2-microglobulin, serum creatinine (sCr), serum calcium (sCa), and C-reactive protein concentrations was higher in patients with higher SUVmax (≥ 5.3). Prevalence of elevated sCa, sCr, and extramedullary disease (EMD) was higher in patients with a higher number of focal lesions (≥ 10). SUVmax, serum free-light chain (sFLC) ratio, and EMD were independent predictors of PFS and OS. The NPPS used SUVmax, sFLC ratio, and EMD could effectively predict OS and was more effective at prognostication than the ISS, R-ISS, and R2-ISS.

CONCLUSIONS

[¹⁸F]-FDG PET/CT parameters play a significant role in predicting prognosis in NDMM patients. The NPPS based on SUVmax, sFLC ratio, and EMD outperformed the ISS, R-ISS, and R2-ISS in prognostication.

CCL18 promotes migration and invasion of multiple myeloma cells and is associated with poor prognosis

CCL18 has recently been implicated in malignancies and is increasingly mentioned as a potential tumoral biomarker and furtherly a molecular target for therapeutic intervention, but its expression and clinical significance in multiple myeloma have not been explored. Serum CCL18 levels were measured by ELISA method in 254 newly diagnosed multiple myeloma (NDMM), 21 monoclonal gammopathy of undetermined significance (MGUS) and 22 healthy adults. The study suggests that the serum CCL18 level in NDMM patients was significantly higher than that in MGUS and healthy adults. High level of CCL18 were associated with advanced ISS and R-ISS stages in MM. Patients with high serum CCL18 displayed a significantly more frequent occurrence of renal impairment and hypercalcemia, while the proportion of achieving complete remission (CR) was lower. More importantly, Cox analysis identified CCL18 and LDH as independent predictors of PFS in MM patients, whereas CCL18, creatinine and LDH were independent predictors of OS. Finally, we show that CCL18 can promote migration and invasion of myeloma cell lines RPMI8226 and MM.1S. CCL18 may play a tumor-promoting role by increasing the migration and invasion abilities of myeloma cells.

Carbon Dot-Anchored Cobalt Oxyhydroxide Composite-Based Hydrogel Sensor for On-Site Monitoring of Organophosphorus Pesticides

The development of a portable, quantitative, and user-friendly sensor for on-site monitoring of organophosphorus pesticides (OPs) is significantly urgent to guarantee food safety. Herein, a carbon dot/cobalt oxyhydroxide composite (CD/CoOOH)-based fluorescent hydrogel sensor is constructed for precisely quantifying OPs using a homemade portable auxiliary device. As a fluorescence signal indicator, the orange-emissive CD/CoOOH composite is encapsulated into an agarose hydrogel kit for amplifying the detection signals, shielding background interference, and enhancing stability. Acetylcholinesterase (AChE) catalyzes the hydrolysis of the substrate to produce thiocholine, which induces the decomposition of CoOOH and makes the fluorescence enhancement of the hydrogel platform possible. OPs can specifically block the AChE activity to limit thiocholine production, resulting in a decrease in platform fluorescence. The image color of the fluorescent hydrogel kit is transformed into digital information using a homemade auxiliary device, achieving on-site quantitative detection of paraoxon (model target) with a detection limit of 10 ng mL^-1. Harnessing CD/CoOOH composite signatures, hydrogel encapsulation, and portable optical devices, the proposed fluorescence hydrogel platform demonstrated high sensitivity and good anti-interference performance in agricultural sample analysis, indicating considerable potential in the on-site application.

Looking into Endoplasmic Reticulum Stress: The Key to Drug-Resistance of Multiple Myeloma?

Multiple myeloma (MM) is the second most common hematologic malignancy, resulting from the clonal proliferation of malignant plasma cells within the bone marrow. Despite significant advances that have been made with novel drugs over the past two decades, MM patients often develop therapy resistance, especially to bortezomib, the first-in-class proteasome inhibitor that was approved for treatment of MM. As highly secretory monoclonal protein-producing cells, MM cells are characterized by uploaded endoplasmic reticulum stress (ERS), and rely heavily on the ERS response for survival. Great efforts have been made to illustrate how MM cells adapt to therapeutic stresses through modulating the ERS response. In this review, we summarize current knowledge on the mechanisms by which ERS response pathways influence MM cell fate and response to treatment. Moreover, based on promising results obtained in preclinical studies, we discuss the prospect of applying ERS modulators to overcome drug resistance in MM.

Engineering DNAzyme strategies for fluorescent detection of lead ions based on RNA cleavage-propelled signal amplification

Based on the high recognition ability and flexible programmability of GR5 DNAzyme, two fluorescent biosensors were engineered for amplified detection of Pb²⁺ via incorporating Ti₃C₂T_X MXenes and embedding 2-aminopurine (2-AP), respectively. The quencher-required approach relied on the DNA affinity and fluorescence quenching ability of Ti₃C₂T_X MXenes. Benefiting from the low background signal modulated by Ti₃C₂T_X MXenes, the sensitive determination of Pb²⁺ was achieved in the linear range of 0.2-10 ng mL^-1 with the limit of detection (LOD) of 0.05 ng mL^-1. The quencher-free approach combined the fluorescent trait of 2-AP embedded in DNA structure, and the RNA cleavage-propelled digestion process of Exonuclease I (Exo I) for signal amplification, indicating the sensitive detection of Pb²⁺ with the LOD as low as 0.02 ng mL^-1 in the linear range of 0.1-10 ng mL^-1. Both DNAzyme assays exhibited simple procedures, favorable specificity, rapid analysis, and satisfactory application in standard reference materials (lead in drinking water) and spiked water samples. The two fluorescent biosensors established in this work would not only provide theoretic fundament for DNA adsorption of Ti₃C₂T_X MXenes and the design of 2-AP-embedded DNAzyme assays, but also hold a great potential for on-site monitoring of lead pollution in water samples.

Label-Free Fluorescence Sensing Strategy Based on Functional Nucleic Acids via Energy Transfer between DNA-Templated Silver Nanoclusters and Gold Nanorods

A simple and low-cost fluorescence signal-on sensing strategy has been developed based on functional nucleic acids (FNAs) via energy transfer between DNA-templated silver nanoclusters (DNA-AgNCs) and gold nanorods (GNRs). FNAs were used as highly selective recognition probes, in which an aptamer was used to detect small molecules represented by tetracycline, and DNAzyme was used to detect heavy metal ions represented by Pb²⁺. The fluorescent DNA-AgNCs were synthesized by the designed oligonucleotide sequences, which consisted of three parts: AgNCs synthesis template C₆G₅C₆, spacer T₅, and complementary sequences of the aptamer or enzyme strand. The difference in electrostatic interactions between ss/dsDNA and positively charged GNRs leads to energy transfer with different efficiencies. The analytes represented by tetracycline and Pb²⁺ can destroy the dsDNA structure and reduce the energy-transfer efficiency between DNA-AgNCs and GNRs, thus achieving fluorescence recovery and a signal-on analytical strategy. This strategy has excellent specificity and sensitivity with limit of detections of 4.411 nM for tetracycline and 1.416 nM for Pb²⁺ and has been successfully applied to detect tetracycline in milk and Pb²⁺ in river water. Using DNA-AgNCs formed in situ as signal probes, this strategy does not require labels or modifications and can be completed without complex analytical instruments. Moreover, this strategy can be extended to detect other targets by replacing FNA sequences. Therefore, it has promising prospects in the sensitive, simple, and rapid detection of contaminants in food and environment samples.

Toxicological safety evaluation of Qin-Zhi-Zhu-Dan formula in rats during the treatment and recovery periods

Background: Qinzhi Zhudan Formula (QZZD), optimized from Angong Niuhuang Wan, consists of Radix Scutellariae, Fructus Gardeniae and Pulvis Fellis Suis. We had investigated the neuroprotective effects of QZZD and its active components, and demonstrated that it could treat cerebral ischemia and dementia through multiple pathways and mechanisms. Nevertheless, toxicological data on this formula still remains limited. In the study, we sought to examine the toxicological effects of QZZD during the treatment and recovery periods.

Methods: We investigated potential toxicities of QZZD in Sprague-Dawley (SD) rats via 28-day gavage administration. SD rats were randomly divided into control group and treatment groups of A (0.5 g/kg/d QZZD), B (1.5 g/kg/d QZZD), and C (5.0 g/kg/d QZZD). The 56-day course includes treatment period (administration with water or QZZD once a day for 28 consecutive days) and recovery period (28 days). The rats received daily monitoring of general signs of toxicity and mortality, as well as weekly determination of body weight and food consumption. Moreover, the complete blood cell count, biochemistry, coagulation, and urine indicators, organ weights, and histopathological report were analyzed respectively at the end of the treatment and recovery periods.

Results: There was no death related to the active pharmaceutical ingredients of QZZD during the treatment period. The maximum no observed adverse effect level (NOAEL) was 0.5 g/kg/d, which is approximately 16.7 times of the equivalent dose of clinical dose in rats. In group TB (1.5 g/kg/d QZZD) and TC (5.0 g/kg/d QZZD), there were adverse effects of blue coloring of tail skin, weight loss, a significant increase of total bilirubin (TBIL), blackening of liver and kidney in gross examination, hyperplasia of bile duct and karyomegaly of hepatocytes in histopathological examination. Besides, in females rats, the food consumption was reduced, while in male rats, there was decrease in triglycerides (TG) and slight increase in white blood cell (WBC) count and neutrophils. In group TC (5.0 g/kg/d QZZD), the indicators of red blood cell (RBC) count, hemoglobin (HGB) and hematocrit (HCT) were decreased slightly, while the platelet count (PLT) was increased. However, these changes were not considered to be toxicologically significant because they resolved during the recovery period.

Conclusion: Overall, QZZD exhibited a good safety profile. The maximum no observed adverse effect level was 0.5 g/kg/d, and no target organs toxicity were identified. The present findings might confirm the safety of QZZD in clinical practices.

Systemic regulation of soybean nodulation and nitrogen fixation by nitrogen via isoflavones

Nitrogen (N) inhibits soybean (Glycine max L.) nodulation and N₂ fixation. Isoflavones secreted by soybean roots can stimulate signal transduction for symbiotic nodules, thus playing a key role in root nodule development and N₂ fixation. The relationship between the inhibition of soybean nodulation, N₂ fixation and isoflavones by N is still unclear. In this study, dual-root soybean plants were prepared by grafting, and N or isoflavones were supplied to unilateral roots. The number and dry weight of the soybean nodules, nitrogenase activity, isoflavone concentrations and relative changes in the level of expression of nodulation-related genes were measured to study the response relationship between the N systemic regulation the soybean nodule N₂ fixation and changes in the concentrations of isoflavones in its roots. The results showed that N supply to one side of the dual-root soybeans systematically affected the N₂ fixation of root nodules on both sides, and this effect began in the early stage of nodulation. Moreover, a unilateral supply of N systematically affected the concentrations of daidzein and genistein on both sides of the roots. The concentrations of isoflavones were consistent with the change trend of soybean root nodule and nodulation-related gene expression level. Treatment with unilateral N or isoflavones affected the soybean nodule N₂ fixation and its nodulation-related genes, which had the same response to the changes in concentrations of root isoflavones. N regulates soybean nodulation and N₂ fixation by systematically affecting the concentrations of isoflavones in the roots.

Platform Formed from ZIF-8 and DNAzyme: "Turn-On" Fluorescence Assay for Simple, High-Sensitivity, and High-Selectivity Detection of Pb2

Lead contamination has posed a potential threat to the environment and food safety, arousing extensive concern. In this work, we fabricated a novel fluorescent sensing platform based on zeolitic imidazolate framework-8 (ZIF-8) and DNAzyme for monitoring Pb²⁺ in water and fish samples. ZIF-8 was proposed as a fluorescence quencher with the advantages of simple synthesis, low cost, and high quenching efficiency. The Pb²⁺-dependent GR5 DNAzyme containing the large ssDNA loop can be adsorbed onto ZIF-8 accompanied by fluorescence quenching. Upon binding with Pb²⁺, GR5 DNAzyme was activated and cleaved, leading to the release of FAM-labeled 5-base ssDNA, which restored the fluorescence. The "turn-on" assay can detect Pb²⁺ through the one-pot procedure in the range of 0.01-10.0 nM with a detection limit of 7.1 pM. The platform is promising for on-site monitoring of Pb²⁺ owing to the excellent performance of high sensitivity, low background, strong anti-interference ability, and simple operation.