CRISPR/Cas12a-derived ratiometric fluorescence sensor for high-sensitive Pb2+ detection based on CDs@ZIF-8 and DNAzyme

Benefiting from specific target recognition and trans-cleavage capabilities, the CRISPR/Cas12a system has great application prospects in the design of highly sensitive and rapid fluorescence biosensors. The CRISPR/Cas12a-based fluorophore-quencher molecular beacons exhibit single-color emission and are easily exposed to interference from environmental factors. Herein, we design a CRISPR/Cas12a-derived ratiometric fluorescence sensor for Pb2+ detection based on embedded carbon dots@zeolitic imidazolate framework-8 (CDs@ZIF-8) composites and DNAzyme. The functions of ZIF-8 about encapsulating red emissive CDs in the inner cavity and adsorbing DNA on the outer surface are integrated to establish dual fluorescence signals, thereby reducing the possibility of interference and improving sensing accuracy. The presence of Pb2+ is converted into the change of activator by the GR5 DNAzyme to activate the CRISPR/Cas12a system, which provides signal amplification through multiple turnovers of side branch cutting, achieving highly sensitive detection of Pb2+ with a low detection limit of 18 pM. This method has the advantages of simplicity, universality, and excellent quantitative ability, and has broad prospects in sensing applications.

Zeolitic Imidazolate-Framework-Engineered Heterointerface Catalysis for the Construction of Plant-Wearable Sensors

Plant-wearable sensors provide real-time information that enables pesticide inputs to be finely tuned and play critical roles in precision agriculture. However, tracking pesticide information in living plants remains a formidable challenge owing to inadequate shape adaptabilities and low in-field sensor sensitivities. In this study, plant-wearable hydrogel discs are designed by embedding a dual-shelled upconversion-nanoparticles@zeolitic-imidazolate-framework@polydopamine (UCNPs@ZIF@PDA) composite in double-network hydrogels to deliver on-site pesticide-residue information. Benefiting from the enzyme-mimetic catalytic activity of ZIFs and enzyme triggered-responsive property of PDA shell, the hydrogel discs are endowed with high sensing sensitivity toward 2,4-dichlorophenoxyacetic acid pesticide at the nanogram per milliliter level via boosting fluorescence quenching efficiency. Notably, hydrogel discs mounted on tomato plants exhibit sufficient adaptability to profile dynamic pesticide degradation when used in conjunction with an ImageJ processing algorithm, which is practically applicable. Such hydrogel discs form a noninvasive and low-cost toolkit for the on-site acquisition of pesticide information, thereby contributing to the precise management of the health status of a plant and the judicious development of precision agriculture.

[10-Methacryloyloxydecyl dihydrogen phosphate in resin-to-zirconia bonding durability: a systematic review and meta-analysis]

Objective: To systematically assess the durability of the 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) pretreated resin-to-zirconia bonding and conducted a meta-analysis to provide clinical guidance on zirconia bonding strategies. Methods: A comprehensive search was conducted on PubMed, Scopus, Web of Science, CNKI, and Wanfang database to identify relevant studies on the resin-to-zirconia bonding after surface pretreatment with 10-MDP. Strict inclusion and exclusion criteria were applied to select appropriate literature and extract essential information and data. The included studies were categorized based on aging methods (water storage, thermocycling, or both), 10-MDP application methods (within primer, adhesive, resin cement, or both), and additional surface treatments (alumina sandblasting, tribochemical silica coating, acid etching, laser etching, and plasma treatment) and were analyzed by Review Manager 5.4. The evaluation indicator was the bonding strength of zirconia after surface pretreatment with 10-MDP. Results: A total of 72 studies were included in the systematic review, with 68 studies eligible for the meta-analysis. The bonding strength of zirconia decreased significantly after aging [P<0.001; mean difference (MD): 5.58; 95%CI: 5.11-6.05]. No significant differences in bonding strength of zirconia were observed after aging when employing various application methods of 10-MDP (all P>0.05). The bonding strength of zirconia was significantly enhanced after aging when 10-MDP was applied in conjunction with additional surface treatments, as compared to the application of 10-MDP alone (P<0.001; MD: 10.17; 95%CI: 8.20-12.14). Conclusions: The bonding strength of zirconia pretreated with 10-MDP exhibited a reduction after undergoing water storage or thermocycling. The application of 10-MDP with additional surface treatments enhanced the bonding strength of zirconia after aging, while the application methods of 10-MDP did not exert an influence.

Comparison of the efficacy of febuxostat vs. benzbromarone in the treatment of gout: a meta-analysis in Chinese gout patients

OBJECTIVE

Febuxostat and benzbromarone are two common drugs for the treatment of gout, but the clinical efficacy of these two drugs is controversial. This meta-analysis aimed to compare the efficacy of febuxostat and benzbromarone in the treatment of gout.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were searched for articles related to febuxostat and benzbromarone in the treatment of gout from inception to January 7, 2023. Titles and abstracts were reviewed in accordance with predesigned inclusion and exclusion criteria, and data were extracted independently. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies, and the continuous variables were expressed as the standard mean square error (SMD) by STATA 16 (Stata Corp., College Station, TX, USA). The sensitivity analysis was conducted by randomly removing a study, and the heterogeneity was analyzed by funnel plots and Egger's test.

RESULTS

According to the search strategy, a total of 1,043 publications were retrieved from the three aforementioned databases, of which 45 publications were excluded due to duplication. Fourteen studies remained after screening titles and abstracts, and a total of 7 studies met the inclusion criteria after a comprehensive evaluation of the 14 studies. Meta-analysis showed that the uric acid (UA)-reducing effect of febuxostat is better than that of benzbromarone, while febuxostat showed a better ability to improve the estimated glomerular filtration rate (eGFR) and reduce Cr and blood urea nitrogen (BUN). In terms of hepatotoxicity, benzbromarone was not as potent as febuxostat in increasing alanine transaminase (ALT) and aspartate transaminase (AST), suggesting that benzbromarone has less hepatotoxicity. Moreover, there was no significant difference in the effect on blood lipid levels between the two drugs.

CONCLUSIONS

The beneficial effect of febuxostat on renal function-related indexes such as the eGFR, Cr and BUN is significant, while benzbromarone is more effective in reducing UA and has relatively less hepatotoxicity. The specific efficacy of the two drugs needs to be confirmed by further research.

Zeolitic imidazolate framework/aptamer-based fluorescence assay for the facile and high-sensitivity detection of acetamiprid

Accurate monitoring of trace pesticides in complex matrix remains a challenge in food safety supervision. Herein, we designed a facile zeolitic imidazolate framework (ZIF)-8/aptamer-based assay for the sensitive detection of acetamiprid. ZIF-8 efficiently adsorbs 6-carboxyfluorescein-labeled complementary DNA (cDNA-FAM) via electrostatic interaction, hydrogen bonding and Zn2+ coordination, which contributed to resistance to cDNA-FAM displacement by biological ligands. ZIF-8 serves as an "ion pump" that contains lots of Zn2+ who boosts cDNA-FAM adsorption and triggers the photoinduced electron transfer (PET) effect from FAM to ZIF-8, improving the sensing sensitivity. Acetamiprid could trigger the change in the adsorption state of cDNA-FAM, further tuning the PET effect and causing fluorescence conversion. The fluorescence assay showed a high sensitivity for monitoring acetamiprid with a detection limit of 0.05 ng mL-1 in the apple sample. This ZIF/DNA-based analytical platform provides a powerful tool for facile and low-cost screening of pesticide residues, with promising applications in food safety monitoring.

[Association between cognitive function and probability of prodromal Parkinson's disease in middle aged and elderly people aged 55 years and above in 4 provinces in China]

Objective: To analyze probability of prodromal Parkinson's disease (pPD) and assess the association between global cognitive function and cognitive domain function and probability of pPD in ≥55 years old middle-aged and elderly people in Hebei, Zhejiang, Shaanxi and Hunan Provinces in China. Methods: Data were collected from dataset of the Community-based Cohort Study on Nervous System Disease 2020. We selected 4 634 Alzheimer disease and Parkinson's disease free persons aged ≥55 years with completed information on demographics, disease history, cognitive test, and risk factors of Parkinson's disease for this study. Cognitive function was assessed using Montreal Cognitive Assessment Scale (Chinese version). Calculation of probability of pPD and assessment of possible/probable pPD were performed according to the criteria published by the International Parkinson and Movement Disorder Society. Multivariate linear regression model was used to analyze the association between cognitive function and probability of pPD. Results: The M (Q1,Q3) of global cognitive function and cognitive domains in terms of memory, execution, visuospatial function, language, attention and orientation were 25 (20, 30), 13 (11, 15), 10 (7, 12), 6 (4, 7), 5 (4, 6), 15 (12, 18) and 6 (6, 6) points, respectively. The M(Q1,Q3) of probability of pPD was 0.42% (0.80%, 1.73%), and the proportion of the study subjects with possible/probable pPD was 0.4%. Differences in the distribution of probability of pPD were significant among groups by total cognitive score quartiles (P<0.001), and the difference in proportions of study subjects with possible/probable pPD was significant and showed decline trend (P=0.001). After adjusted for confounders, the results of multivariate linear regression analyses showed that probability of pPD in the Q2, Q3 and Q4 group decreased by 23.4%, 31.2% and 20.1% compared with Q1 group, and corresponding β values were 0.766 (95%CI: 0.702-0.836), 0.688 (95%CI: 0.631-0.751) and 0.799 (95%CI: 0.730-0.875), respectively, the trend was significant (P<0.001). Higher index scores of execution, visuospatial function, language, attention and orientation were highly related to lower probability of pPD (P<0.001). Conclusion: Declines in global cognitive function and cognitive domains of execution, visuospatial function, language, attention and orientation might increase the probability of pPD in middle-aged and elderly people, suggesting the importance of cognitive intervention in early stage for pPD prevention.

Toxoplasmosis in ring-tailed lemurs (Lemur catta) and a peahen (Pavo cristatus) in a zoological collection caused by the common toxoplasma genotype in wild animals in the US

Toxoplasmosis is caused by the ubiquitous Apicomplexan protozoan Toxoplasma gondii. This pathogen affects domestic and wildlife species, but prosimians including ring-tailed lemurs (Lemur catta) are highly susceptible to infection with high mortality rates. Avian species are considered resistant to infection and are often used in surveillance efforts to determine genotypes of T. gondii present in geographical areas. This study describes the gross and histologic lesions of an outbreak of toxoplasmosis in a university-run zoological collection involving three ring-tailed lemurs and a peahen (Pavo cristatus). DNA was extracted from the liver of the lemurs and peahen to determine the genotype of T. gondii by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), which revealed that all samples were ToxoDB PCR-RFLP genotype #5 (haplogroup 12) that is common in wildlife in North America.

Association of Dietary Quality with Cognitive Function in Chinese Adults Aged 55 Years and Above: A Longitudinal Study

OBJECTIVES

Diet is an important modifiable factor for brain health and aging. Present study aimed to explore association of dietary quality with cognitive function and poor cognition in middle-aged and older adults participating in the China Health and Nutrition Survey (CHNS).

DESIGN

A longitudinal study with a twenty-year follow-up.

SETTING AND PARTICIPANTS

Data were drawn from the CHNS 1997, 2000, 2004, 2006, 2015 and 2018. Subjects aged 55 years and more who participated in at least two waves and had completed data on socio-demographics, lifestyle, disease history, anthropometrics, dietary measure and cognitive assessment were eligible in present study.

METHODS

Baseline diet were assessed by 3-day 24-hour dietary recalls and used to evaluate diet quality via China Elderly Dietary Guidelines Index 2022 (CDGI 2022-E). Cognitive function was examined using part items of the Telephone Interview for Cognitive Status-modified. Three-level linear mixed effects models and three-level mixed effects logistic regression models were performed to estimate the association between diet quality and cognitive function and odds of poor cognition, respectively.

RESULTS

At baseline, 4173 subjects with median age of 63.7 years were recruited. Median of CDGI 2022-E total score was 44.7. Median score of global cognition was 16.0, and the proportion of people with poor cognitive function was 13.9%. Difference in global cognitive score was observed by tertiles of CDGI 2022-E (p<0.05). Significant associations of high diet quality with increment in global cognitive score [β (95%CI): 0.704 (0.394~1.015)], composite cognitive z score [0.086 (0.045~0.128)] and standardized verbal memory score [0.221 (0.122~0.320)] were observed in total subjects. Consistent associations were also found in those below 65 years at baseline. The likelihood of poor cognition in the highest tertile of CDGI 2022-E decreased by 18% (95%CI: 0.698~0.965) relative to the lowest tertile group in total population.

CONCLUSIONS

High diet quality may be beneficial for improving cognitive function and delaying cognitive decline in Chinese middle-aged and older population.

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.

[Efficacy of recombinant human growth hormone treatment in children born small for gestational age with syndromic and non-syndromic short stature]

Objective: To analyse the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) with syndormic and non-syndormic short stature. Methods: The clinical data of 59 children born SGA who were diagnosed as short stature and admitted to the Center of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital from July 2012 to June 2021 were collected and analyzed. According to the 2019 consensus on short stature, they were divided into syndromic group and non-syndromic group. Before treatment and 6, 12, 18 and 24 months after treatment, height standard deviation score (Ht-SDS), difference of height standard deviation (∆Ht-SDS) and homeostasis model assessment-insulin resistance index (HOMA-IR) were compared between groups, while Ht-SDS and HOMA-IR were compared before and after treatment. Independent t test or Kruskal-Wallis test were used for comparison between the 2 groups, and paired t test or Mann-Whitney U test were used for the intra-group comparison. Results: Among the 59 cases, 37 were males and 22 females, aged (5.5±2.3) years. There was no significant difference in Ht-SDS after 12 months of treatment between 2 groups (0.9±0.4 vs. 1.2±0.4, t=1.68, P=0.104) or in height SDS after 24 months of treatment (1.4±0.7 vs. 1.9±0.5, t=1.52, P=0.151). After 12 months of treatment, the insulin resistance index of the non-syndromic group was significantly higher than that of the syndromic group (2.29 (1.43, 2.99) vs. 0.90 (0.55, 1.40), Z=-2.95, P=0.003). There were significant differences in Ht-SDS between 6 months and before treatment, 12 months and 6 months in syndromic type (Z=7.65, 2.83 P<0.001, P=0.020), but all were significant differences in non-syndromic type between 6 months and before treatment, 12 months and 6 months, 18 months and 12 months, 24 months and 18 months (Z=11.95, 7.54, 4.26, 3.83, all P<0.001). Conclusion: The efficacy of rhGH treatment in children born SGA is comparable between syndromic and non-syndromic short stature cases, but non-syndromic children treated with rhGH need more frequent follow-up due to the risk of insulin resistance.

[Association between fasting plasma glucose and mild cognitive impairment in Chinese 55 and older population from four provinces]

Objective: To analyze the association of fasting plasma glucose (FPG) with mild cognitive impairment (MCI) in the Chinese middle-aged and elderly population from four provinces. Methods: Data were drawn from the baseline data of the Community-based Cohort Study on Nervous System Disease 2018-2019. We selected 3 272 subjects aged 55 and above with completed information on demographics, lifestyle, disease history, cognitive test, psychological assessment, and bio-chemistries measurement, and who were capable of performing basic activities of daily living but without Alzheimer's disease during recruitment. A multivariate logistic regression model was employed to analyze the association between FPG and MCI. Results: Median level of FPG in the study population was 5.5 mmol/L. The prevalence of MCI was 24.8%, and those in groups of the FPG quintile were 19.4%, 22.2%, 29.2%, 26.6%, and 26.1%, respectively, which significantly increased the trend (P=0.002). After adjustment of confounders, multivariate logistic regression analysis found that the MCI risk of subjects in the Q₃,Q₄ and Q₅ groups was 1.641 (95%CI: 1.226-2.131), 1.373 (95%CI: 1.036-1.825), 1.402 (95%CI: 1.054-1.871) times as high as that in the Q₁ group, respectively. Conclusion: High FPG level might serve as a risk factor for MCI in the middle-aged and elderly population, suggesting the importance of monitoring and controlling plasma glucose even without diabetes.

[Transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin]

Objective: To understand the transmission characteristics and risk factors of household COVID-19 clusters caused by 2019-nCoV Omicron variant in Tianjin and provide evidence for COVID-19 prevention and control. Methods: Field epidemiological method was used to investigate the epidemiological characteristics of COVID-19 cases, and descriptive analysis was used to describe the epidemiological information. Results: A total of 430 cases were reported in this epidemic in Tianjin, in which 409 cases were included in this study. Among these cases, 70.90% (290/409) occurred in families. The family secondary attack rate was 33.64% The family secondary attack rate in age group 12-17 years (13.79%) was significantly lower than that in age group 18-49 years (36.48%), the OR was 0.378 (95%CI: 0.170-0.840). The logistic regression analysis showed that compared with centralized quarantine, the OR of the index cases found in closed-off/controlled areas and in home quarantine were 2.951 (95%CI:1.322-6.586) and 2.287 (95%CI:1.164-4.495), respectively, compared with the cases without sore throat, the OR of the index cases with sore throat was 3.003 (95%CI: 1.576-5.720), and compared with cases in families without completed COVID-19 vaccinations in all members, the OR of the cases in families with completed COVID-19 vaccinations in all members was 0.268 (95%CI: 0.132-0.552). Conclusions: The risk of household transmission of infection with Omicron variant was high. Detecting the index case in closed-off/controlled areas or in home quarantine and sore throat in index cases were the risk factors of the household transmission, completed COVID-19 vaccination was the protective factor.

[Preliminary analysis of the promotion effect of laparoscopic standardized surgical treatment for gastric cancer in regional medical centers in Shanghai]

Objective: To explore the promotion effect of laparoscopic standardized surgery for gastric cancer observational in some regional medical centers in Shanghai. Methods: A retrospective cohort study was carried out. Eleven regional medical centers in Shanghai received the promotion program of laparoscopic standardized surgery for gastric cancer, which was led by Ruijin Hospital, Shanghai Jiaotong University School of Medicine (Shanghai Minimally Invasive Surgery Center) from January to December 2020. Clinicopathological data of gastric cancer patients treated at these 11 regional medical centers before and after the promotion program were collected. Inclusion criteria were as follows: patients undergoing laparoscopic distal gastrectomy or total gastrectomy; gastric cancer confirmed by pathology; without distant metastasis or peritoneal metastasis. Patients who did not undergo laparoscopic D2 radical resection, or received neoadjuvant chemotherapy before surgery, or without complete clinical data were excluded. Patients undergoing laparoscopic surgery from January to December 2019 were included in the pre-promotion group (46 cases). Patients undergoing laparoscopic surgery from January to December 2021 were included in the post-promotion group (102 cases). In addition, patients undergoing laparoscopic surgery at Ruijin Hospital from January 2021 to December were included in the control group (138 cases). The baseline data, perioperative measurements postoperative complications, and pathological results of the three groups were analyzed and compared. Results: There were no significant differences in baseline characteristics among the three groups (all P>0.05). Compared with the pre-promotion group, the operation time in post-promotion group was significantly shorter [(207.3±36.0) minutes vs. (254.2±47.1) minutes, t=7.038,P<0.001], and the number of harvested lymph node was significantly more (24.4±12.2 vs. 18.9±5.5, t=2.900, P=0.004). However, there were no significant differences in the extent of resection, time to fluid intake, and postoperative hospital stay between the two groups (all P>0.05). Compared with the control group, the operation time [(207.3±36.0) minutes vs (172.6±26.0) minutes, t=8.281, P<0.001], time to fluid intake [(6.3±3.2) days than (5.5±3.0) days, t=2.029, P=0.044], and the postoperative hospital stay [(14.3±5.6) days vs. (10.1±4.8) days, t=6.036, P<0.001] in the post- promotion group were still longer. Total gastrectomy was less common in the post-promotion group compared with the control group [18 cases (17.6%) vs. 41 cases (29.7%), χ²=7.380, P=0.007]. However, there was no significant difference in the number of harvested lymph node between the two groups (P>0.05). The morbidity of postoperative complication in the post-promotion group (9.8%, 10/102) was significantly lower than that in the pre-promotion group (23.9%, 11/46) (χ²=5.183, P=0.023), while above morbidity was not significantly different between the post-promotion group and the control group [9.8% vs. 6.5% (9/138), χ²=0.867, P=0.352]. Conclusion: After the promotion of laparoscopic standardized surgery for gastric cancer in regional medical centers, the standardization degree of surgery has been improved, and the morbidity of postoperative complication decreases. Laparoscopic standardized surgery for gastric cancer can be promoted to more regional medical centers.

[Consistency evaluation of 2 methods in detecting serum insulin-like growth factorⅠ in children]

Objective: To evaluate the consistency of mass spectrometry (MS) and chemiluminescence immunoassay (CLIA) in detecting serum insulin-like growth factor-1 (IGF-1) and IGF-1 standard deviation score (SDS). Methods: This cross-sectional parallel control study prospectively collected the serum samples of 115 children with short stature disorders who were admitted in the Department of Endocrinology, Beijing Children's Hospital, Capital Medical University from February 2020 to December 2021. The serum IGF-1 level was detected by CLIA and MS, and converted to SDS for consistency analysis. Pearson analysis was used to analyze the correlation between the 2 methods, and Deming regression equation was established. Bland-Altman diagram and weighted Kappa coefficient were used to evaluate the consistency of the 2 methods. Results: There were 46 boys (40.0%) and 69 girls (60.0%), aged (8±3) years. Among the 115 cases, 37 were Turner syndrome, 59 were small for gestational age (SGA) at term, 1 was growth hormone deficiency (GHD) and 18 were other diseases. Pearson correlation analysis showed a preferable correlation between IGF-1 measured by the 2 detection methods (r=0.94, P<0.01), and IGF-1 SDS was also significantly correlated (r=0.92, P<0.01). Bland-Altman analysis showed that the consistency of serum IGF-1 levels detected by the 2 methods was poor, and the mean difference between CLIA and MS was 33.38 μg/L. The result detected by CLIA was significantly higher than that by MS, with SDS of 43.51 μg/L (95%CI -51.89-118.7 μg/L). After converting the results to SDS and removing 3 outliers (including 1 GHD patient), the weighted Kappa showed acceptable consistency (κ=0.68). Conclusion: In clinical application, after converting to IGF-1 SDS, IGF-1 detected by MS and CLIA can be used for cross-reference, but too high or too low levels should be cautious about.

[Research advances on the characteristics of fibroblast in keloid]

In re-cent 20 years, the development of cell biology technology has promoted the research of keloid. Keloid fibroblasts (KFbs) are the main effector cells in keloid, which are closely related to the occurrence and development of keloid. It is significantly different in terms of biological characteristics and gene expression between KFbs and normal fibroblasts. This articles reviews the characteristics of KFbs from multiple perspectives, describing its biological character- istics in details including microstructures, metabolic character- istics, and proliferation properties, and introducing the main characteristics of heterogeneity and genomics of KFbs. The further research on KFbs will help to elucidate the pathogenesis of keloids and provide valuable strategies for the prevention and treatment of keloids.

Ratiometric fluorescent hydrogel for point-of-care monitoring of organophosphorus pesticide degradation

The residues of organophosphorus pesticides have caused the potential risk in environment and human health, arousing worldwidely great concern. Herein, we fabricated a robust gold nanoclusters/MnO₂ composites-based hydrogel portable kit for accurate monitoring of paraoxon residues and degradation in Chinese cabbages. With the immobilization of gold nanoclusters/MnO₂ composites into a hydrogel, a ratiometric fluorescent signal is generated by catalyzing the oxidation of o-phenylenediamine, which possesses a built-in correction with low background interference. Coupling with acetylcholinesterase catalytic reactions and pesticide inhibition effect, the portable kit can sensitively detect paraoxon residues with a detection limit of 5.0 ng mL^-1. For on-site quantification, the fluorescent color variations of portable kit are converted into digital information that exhibits applicative linear range toward pesticide. Notably, the hydrogel portable kit was successfully applied for precisely monitoring the residue and degradation of paraoxon in Chinese cabbage, providing a potential pathway toward practical point-of-care testing in food safety monitoring.

[Soluble egg antigen of Schistosoma japonicum induces macrophage apoptosis in mice]

OBJECTIVE

To investigate the dynamic changes of macrophage numbers and apoptosis during Schistosoma japonicum infection, and to investigate the possible mechanisms of macrophage apoptosis induced by S. japonicum soluble egg antigen (SEA).

METHODS

C57BL/6 mice at ages of 6~8 weeks were randomly divided into 4 groups, including three experimental groups and a normal control group. Each mouse in the experimental groups was infected with (12 ± 1) cercariae of S. japonicum via the abdominal skin, and all mice in an experimental group were sacrificed 3, 5, 8 weeks post-infection, respectively, while mice in the control group were not infected with S. japonicum cercariae and sacrificed on the day of S. japonicum infection in the experimental group. Mouse liver specimens and peritoneal exudation cells were sampled in each group, and the dynamic changes of macrophage numbers and apoptosis were detected. Mouse peritoneal macrophages were isolated, purified and treated with S. japonicum SEA, PBS and ovalbumin (OVA) in vitro, and the macrophage apoptosis was detected using flow cytometry. The mRNA and protein expression of BCL-2 protein family members were determined in macrophages using real-time quantitative PCR (qP-CR) and Western blotting assays, and the activation of caspase 3 was determined using flow cytometry and Western blotting. In addition, macrophages were in vitro treated with S. japonicum SEA in presence of a caspase inhibitor, H₂O₂ or N-acetyl-L-cysteine, and the apoptosis of macrophages was detected using flow cytometry.

RESULTS

The total macrophage numbers continued to increase in mouse liver [(0.873 ± 0.106) × 106, (2.737 ± 0.460) × 10⁶ and (3.107 ± 0.367) × 10⁶ cells, respectively; F = 81.900, P < 0.01] and peritoneal specimens [(5.282 ± 1.136) × 105, (7.500 ± 1.200) × 10⁵ and (12.800 ± 0.800) × 10⁵ cells, respectively; F = 55.720, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum, and the numbers of apoptotic macrophages also continued to increase in mouse liver [(0.092 ± 0.018) × 10⁶, (0.186 ± 0.025) × 10⁶ and (0.173 ± 0.0270) × 10⁶ cells; F = 57.780, P < 0.01] and peritoneal specimens [(0.335 ± 0.022) × 10⁵, (0.771 ± 0.099) × 10⁵ and (1.094 ± 0.051) × 10⁵ cells; F = 49.460, P < 0.01] 3, 5 and 8 weeks post-infection with S. japonicum. The apoptotic rate of SEA-treated macrophages [(24.330 ± 0.784)%] was significantly higher than that of PBS-[(18.500 ± 1.077)%] and OVA-treated macrophages [(18.900 ± 1.350)%] (both P values < 0.01). There were no significant differences in the mRNA or protein expression of Bcl-2 [Bcl - 2 mRNA expression: (1.662 ± 0.943) vs. (1.000 ± 0.000), t = 1.215, P > 0.05; BCL protein expression: (0.068 ± 0.004) vs. (0.070 ± 0.005), t = 0.699, P > 0.05], Bax [Bax mRNA expression: (0.711 ± 0.200) vs. (1.000 ± 0.000), t = 2.507, P > 0.05; BAX protein expression: (0.089 ± 0.005) vs. (0.097 ± 0.003), t = 2.232, P > 0.05] and Bak [Bak mRNA expression: (1.255 ± 0.049) vs. (1.00 ± 0.00), t = 0.897, P > 0.05; BAK protein expression: (0.439 ± 0.048) vs. (0.571 ± 0.091), t = 2.231, P > 0.05] between in SEA- and PBS-treated macrophages. S. japonicum SEA induced macrophage apoptosis in the presence of a caspase inhibitor (F = 0.411, P > 0.05); however, SEA failed to induce macrophage apoptosis in the presence of H₂O₂ or NAC (F = 11.880 and 9.897, both P values < 0.05).

CONCLUSIONS

S. japonicum SEA may induce macrophage apoptosis through promoting reactive oxygen species expression during S. japonicum infections in mice.