Integration of multienzyme co-immobilization and biomimetic catalysis in magnetic metal-organic framework nanoflowers for α-amylase detection in fermentation samples

Multiple enzymes induce biological cascade catalysis is essential in nature and industrial production. However, the shortcomings of enzymes, including unsatisfactory stability, reusability, and sensitivity in harsh microenvironment, have restricted their broader use. Here, we report a facile method for fabricating a cascade system by combining the benefits of immobilized enzymes and biomimetic catalysis based on magnetic metal-organic framework nanoflowers (mMOFNFs). mMOFNFs prepared through the layered double hydroxide-derived strategy exhibited remarkable peroxidase-like activity and accessible amino interface, enabling it to serve not only as a reliable carrier for α-glucosidase and glucose oxidase fixation, but also as a nanozyme participating in cascade. On this basis, a colorimetric biosensor of excellent sensitivity and selectivity for α-amylase detection was constructed with a wide range (2-225 U L-1), low detection limit (2.48 U L-1), and rapid operation (30 min). This work provides a versatile strategy for establishing multi-enzyme cascade systems and rapid analysis of α-amylase.

Enzyme-integrated metal-organic framework platform for cascade detection of α-amylase

As one of the most important industrial enzymes, α-amylase is widely used in food processing, such as starch sugar and fermentation, bringing high added value to industry of more than a trillion dollars. We developed a multi-enzyme system (Glu&Gox@Cu-MOF-74) prepared by embedding α-glucosidase (Glu) and glucose oxidase (Gox) into the biomimetic metal-organic framework Cu-MOF-74 using in situ encapsulation within 15 min at room temperature for efficient and sensitive detection of α-amylase activity. Benefitting from the remarkable peroxidase-mimicking property and rigid skeleton of Cu-MOF-74, the biocatalytic platform exhibited excellent cascade activity and tolerance in various extremely harsh environments compared to natural enzymes. On this basis, a cascade biocatalytic platform was constructed for the detection of α-amylase activity with wide linear range (5-100 U/L) and low limit of detection (1.45 U/L). The colorimetric cascade scheme is important for the sensitive and selective determination of α-amylase in complex fermentation samples, and the detection time is short (~0.5 h). This work provides new ideas for the detection of α-amylase based on the cascade amplification method.

High-sensitivity profiling of dipeptides in sauce-flavor Baijiu Daqu by chemical derivatization and ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry

Dipeptides in sauce-flavor Baijiu Daqu are protein degradation products during the fermentation of Daqu, which are believed to play a crucial role in the flavor and quality of Baijiu. Herein, we integrated dansyl chloride derivatization with ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) for comprehensively profiling dipeptides in Daqu. The derivatization efficiency was higher than 99.1 % for all 17 dipeptide standards under the optimized derivatization conditions. In total, 118 dipeptides were detected in Daqu. The method was validated and the analytical characteristics including the linearity (spanned across 2-4 orders of magnitude), precision (1.2-19.9 %), limit of detection (varied from 1.1 to 53.4 pmol/mL) and the stability (3.6-15.8 %) are satisfactory. The usefulness of the method was examined by studying the distribution characteristics of dipeptides in Daqu under different production conditions. The present method provides an effective and robust strategy for comprehensively analyzing dipeptide compounds in complex biological samples.

[Interpretation of the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030)]

On June 16, 2023, National Disease Control and Prevention Administration of the People's Republic of China, in collaboration with other ministries, formulated and issued the Action Plan to Accelerate the Elimination of Schistosomiasis in China (2023-2030). The implementation of this plan provides an important basis for achieving the targets set in the "Healthy China 2030" action plan and the implementation of the rural revitalization strategy. This paper describes the background, principles, targets, control strategies, safeguard measures and effectiveness evaluation of the plan, in order to guide the scientific and standardized implementation of actions for schistosomiasis elimination at the grassroots level, and facilitate the progress towards elimination of schistosomiasis in China with a high quality.

Fusion data from FT-IR and MALDI-TOF MS result in more accurate classification of specific microbiota

Microbes are usually present as a specific microbiota, and their classification remains a challenge. MALDI-TOF MS is particularly successful in library-based microbial identification at the species level as it analyzes the molecular weight of peptides and ribosomal proteins. FT-IR allows more accurate classification of bacteria at the subspecies level due to the high sensitivity, specificity and repeatability of FT-IR signals from bacteria, which is not achievable with MALDI-TOF MS. Previous studies have shown that more accurate identification results can be obtained by the fusion of FT-IR and MALDI-TOF MS spectral data. Here, we constructed 20 groups of model microbiota samples and used FT-IR, MALDI-TOF MS, and their fusion data to classify them. Hierarchical clustering analysis (HCA) showed that the classification accuracy of FT-IR, MALDI-TOF MS, and the fusion data was 85%, 90%, and 100%, respectively. These results indicate that both FT-IR and MALDI-TOF MS can effectively classify specific microbiota, and the fusion of their spectral data could improve the classification accuracy. The FT-IR and MALDI-TOF MS data fusion strategy may be a promising technology for specific microbiota classification.

MALDI-TOF MS Is an Effective Technique To Classify Specific Microbiota

MALDI-TOF MS is well-recognized for single microbial identification and widely used in research and clinical fields due to its specificity, speed of analysis, and low cost of consumables. Multiple commercial platforms have been developed and approved by the U.S. Food and Drug Administration. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used for microbial identification. However, microbes can present as a specific microbiota, and detection and classification remain a challenge. Here, we constructed several specific microbiotas and tried to classify them using MALDI-TOF MS. Different concentrations of nine bacterial strains (belonging to eight genera) constituted 20 specific microbiotas. Using MALDI-TOF MS, the overlap spectrum of each microbiota (MS spectra of nine bacterial strains with component percentages) could be classified by hierarchical clustering analysis (HCA). However, the real MS spectrum of a specific microbiota was different than that of the overlap spectrum of component bacteria. The MS spectra of specific microbiota showed excellent repeatability and were easier to classify by HCA, with an accuracy close to 90%. These results indicate that the widely used MALDI-TOF MS identification method for individual bacteria can be expanded to classification of microbiota. IMPORTANCE MALDI-TOF MS can be used to classify specific model microbiota. The actual MS spectrum of the model microbiota was not a simple superposition of every single bacterium in a certain proportion but had a specific spectral fingerprint. The specificity of this fingerprint can enhance the accuracy of microbiota classification.

Taking Microbiota into Consideration in Mesenchymal Stem Cell Research

Mesenchymal stem cells (MSCs) are a promising therapy in regenerative medicine, but the clinical efficacy has yet to be identified, because the functions of MSCs are modulated by many factors, including the age and health condition of donors, origin of the tissue, and several other unknown factors. Recently, it has been revealed that, besides host factors, the microbiota that inhabits the human body is a modulator of MSCs as well. Here, we highlight the role of microbiota in the alteration of MSCs functions, with a specific focus on the self-renewal ability, multiple differentiation potential, and the immunomodulation capacity of MSCs. We also review the clinical trials and model research on the synergic and antagonistic effects of microbiota in stem cell therapy. In addition, we discuss the underlying mechanisms of the interplay between microbiota and MSCs, which are elucidated using omics approaches followed by verification experiments. As oral and maxillofacial tissues are important sources of MSCs, as well as a major access to diverse microbes, further studies are needed to elucidate these interactions in the oral field to make greater advancements in regenerative medicine.

Insights into the novel function of system Xc- in regulated cell death

System Xc-, also named cystine/glutamate antiporter, is an important intracellular antioxidant element. It is composed of the light chain SLC7A11 (xCT) and the heavy chain SLC3A2 (4F2hc) and functions as raw materials for the synthesis of glutathione (GSH). Recent studies have demonstrated that system Xc- plays an important role in different types of regulated cell death, which is referred to cell death controlled by dedicated molecular machinery. It has been shown that system Xc- involves in ferroptosis, apoptosis, and autophagy-dependent cell death, contributing to different diseases and drug resistance, such as cancer, neurological disorders, and cisplatin resistance to cancers. To date, the intervention of system Xc- by its inhibitors or activators displays a beneficial effect on the treatment of certain diseases. In this review, we summarize recent findings on the role of system Xc- in regulated cell death, including molecular mechanisms and potential therapeutic applications.

Comparing nanoparticle polymeric micellar paclitaxel and solvent-based paclitaxel as first-line treatment of advanced non-small-cell lung cancer: an open-label, randomized, multicenter, phase III trial

BACKGROUND

Polymeric micellar paclitaxel (pm-Pac) is a novel Cremophor EL-free, nanoparticle micellar formulation of paclitaxel. We aimed to compare the efficacy and safety between pm-Pac plus cisplatin and solvent-based paclitaxel (sb-Pac) plus cisplatin in advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 448 stage IIIB to IV NSCLC patients were randomly assigned (2:1) to receive six 3-week cycles of either pm-Pac (230 mg/m²) plus cisplatin (70 mg/m²; n = 300), followed by dose escalation of pm-Pac to 300 mg/m² from the second 3-week cycle if prespecified toxic effects were not observed after the first cycle, or sb-Pac (175 mg/m²) plus cisplatin (70 mg/m²; n = 148). The primary end point was objective response rate (ORR) assessed by independent review committees (IRCs). The secondary end points included IRC-assessed progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Patients in the pm-Pac-plus-cisplatin group showed significant improvements in IRC-assessed ORR compared with those in the sb-Pac-plus-cisplatin group (50% versus 26%; rate ratio 1.91; P < 0.0001). Additionally, subgroup analysis showed that a higher ORR was consistently observed in both squamous and nonsquamous histological types. IRC-assessed median PFS was significantly higher in the pm-Pac-plus-cisplatin group than in the sb-Pac-plus-cisplatin group (6.4-month versus 5.3-month; hazard ratio 0.63; P = 0.0001). Median OS was not significantly different between the two groups. The incidence of treatment-related serious adverse events (9% versus 18%; P = 0.0090) was significantly lower in the pm-Pac-plus-cisplatin group than in the sb-Pac-plus-cisplatin group.

CONCLUSION

Pm-Pac plus cisplatin yielded superior ORR and PFS along with a favorable safety profile and should become an option for patients with advanced NSCLC.

CLINICAL TRIAL IDENTIFIER

ClinicalTrials.gov NCT02667743; https://clinicaltrials.gov/ct2/show/NCT02667743.

Hepatitis B virus and risk of non-Hodgkin lymphoma: An updated meta-analysis of 58 studies

Previous studies have focused on the relationship between hepatitis B virus (HBV) infection and non-Hodgkin lymphoma (NHL). However, the results remain inconsistent and somehow conflicting in different subgroups. The aim of this study was to combine the findings of independent studies to comprehensively assess the association between HBV and NHL using a meta-analysis. Relevant studies were identified through structured keyword searches in PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) database, and 58 studies with a total of 53 714 NHL cases and 1 778 591 controls were finally included. Pooled estimates indicated a significantly increased NHL risk in HBV-infected individuals (summary odds ratio [sOR]: 2.50; 95% confidence interval [CI]: 2.20-2.83) regardless of the study design (case-control studies: sOR: 2.47; 95% CI: 2.16-2.82; cohort studies: sOR: 2.64; 95% CI: 1.78-3.91). Considerable heterogeneity was observed across studies that was primarily attributed to the NHL subtypes (meta-regression: P < .05). Overall, B-cell NHL (sOR: 2.46; 95% CI: 1.97-3.07) presented a stronger association with HBV infection than T-cell NHL (sOR: 1.67; 95% CI: 1.34-2.10). Within the B-cell NHL subtypes, HBV infection was significantly associated with diffuse large B-cell lymphoma (DLBCL, sOR: 2.06; 95% CI: 1.48-2.88) and follicular lymphoma (FL, sOR: 1.54; 95% CI: 1.11-2.12), but not with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) and Burkitt lymphoma. The results of this meta-analysis support a positive link between HBV infection and NHL development. Further investigations for the mechanisms underlying HBV-induced NHL are warranted.

[Qidong Chronic Hepatitis B Cohort: participants enrollment and comparison of baseline characteristics by gender stratification]

Objective: To establish a study cohort of chronic hepatitis B (CHB) in Qidong and evaluate its baseline characteristics. Methods: CHB outpatients of the Third People's Hospital of Qidong were invited to participate in baseline survey from January 1, 2016, including questionnaire survey, liver function detection, serum detection of HBV infection and upper abdomen ultrasound detection. Anticipated sample size was at least one thousand. Baseline data were inputted by EpiData 3.1 software and then cleaned and analyzed by SAS 9.3 software. Results: As of 18 July, 2016, a total of 1 006 participants had been enrolled into the current study, including 615 males with an average age of (44.26±9.97) years and 391 females with an average age of (46.66±11.17) years. The difference in family history of liver disease was not significant between males and females (P>0.05), while the differences in other key information, such as age, education level, tobacco consumption, alcohol drinking, tea consumption, and antiviral intervention, were significant between males and females (P<0.05). Among the key clinical parameters, such as ALT, HBeAg, HBsAg, HBV DNA, albumin, and width of splenic vein and portal vein, only the abnormal rates of ALT and total bilirubin levels were higher in males than in females, the difference was significant (P<0.05). Conclusion: Outpatient department-based CHB cohort was established successfully in Qidong, and sub-cohort could be divided according to the differences on baseline characteristics.

MicroRNA-related genetic variants in iron regulatory genes, dietary iron intake, microRNAs and lung cancer risk

Background

Genetic variations in MicroRNA (miRNA) binding sites may alter structural accessibility of miRNA binding sites to modulate risk of cancer. This large-scale integrative multistage study was aimed to evaluate the interplay of genetic variations in miRNA binding sites of iron regulatory pathway, dietary iron intake and lung cancer (LC) risk.

Patients and methods

The interplay of genetic variant, dietary iron intake and LC risk was assessed in large-scale case-control study. Functional characterization of the validated SNP and analysis of target miRNAs were performed.

Results

We found that the miRNA binding site SNP rs1062980 in 3' UTR of Iron-Responsive Element Binding protein 2 gene (IREB2) was associated with a 14% reduced LC risk (P value = 4.9×10 - 9). Comparing to AA genotype, GG genotype was associated with a 27% reduced LC risk. This association was evident in males and ever-smokers but not in females and never-smokers. Higher level of dietary iron intake was significantly associated with 39% reduced LC risk (P value = 2.0×10 - 8). This association was only present in individuals with AG + AA genotypes with a 46% reduced risk (P value = 1.0×10 - 10), but not in GG genotype. The eQTL-analysis showed that rs1062980 significantly alters IREB2 expression level. Rs1062980 is predicted to alter a miR-29 binding site on IREB2 and indeed the expression of miR-29 is inversely correlated with IREB2 expression. Further, we found that higher circulating miR-29a level was significantly associated with 78% increased LC risk.

Conclusion

The miRNA binding site SNP rs1062980 in iron regulatory pathway, which may alter the expression of IREB2 potentially through modulating the binding of miR-29a, together with dietary iron intake may modify risk of LC both individually and jointly. These discoveries reveal novel pathway for understanding lung cancer tumorigenesis and risk stratification.

Clinical analysis of hyperkalemic renal tubular acidosis caused by calcineurin inhibitors in solid organ transplant recipients

WHAT IS KNOWN AND OBJECTIVE

Calcineurin inhibitor (CNI)-based immunosuppressive regimen is widely used for preventing rejection in solid organ transplantation. Hyperkalemic renal tubular acidosis (RTA) caused by CNI is uncommon and potentially underappreciated. We reported four such cases to increase awareness of this risk and to provide recommendations for its management based on our experience.

CASE SUMMARY

Four middle-aged males underwent solid organ transplant (two kidneys, one liver, one heart) and were treated with CNI-based immunosuppressive regimen (one cyclosporine A, three tacrolimus). On post-operative day 13-35, hyperkalemic hyperchloremic non-gap metabolic acidosis developed. All patients had relatively preserved renal function, normal urine output and plasma aldosterone level. Reduction in CNI dosage was partly effective; the patient on cyclosporine A was treated with fludrocortisone, and two others temporarily switched to sirolimus (SRL).

WHAT IS NEW AND CONCLUSION

We should alert for CNI-induced hyperkalemic RTA in transplant recipients. By CNI dosage reduction or adding low dose fludrocortisone, or temporarily switching to SRL, the prognosis of CNI-induced hyperkalemic RTA is favourable.