Probabilistic risk assessment of dietary exposure to lead in residents of Guangzhou, China.

Lead and its compounds can have cumulative harmful effects on the nervous, cardiovascular, and other systems, and especially affect the brain development of children. We collected 4918 samples from 15 food categories in 11 districts of Guangzhou, China, from 2017 to 2022, to investigate the extent of lead contamination in commercial foods and assess the health risk from dietary lead intake of the residents. Lead was measured in the samples using inductively coupled plasma mass spectrometry. Dietary exposure to lead was calculated based on the food consumption survey of Guangzhou residents in 2011, and the health risk of the population was evaluated using the margin of exposure (MOE) method. Lead was detected in 76.5% of the overall samples, with an average lead content of 29.4 µg kg-1. The highest lead level was found in bivalves. The mean daily dietary lead intakes were as follows: 0.44, 0.34, 0.25, and 0.28 µg kg-1 body weight (bw) day-1 for groups aged 3-6, 7-17, 18-59, and ≥ 60 years, respectively. Rice and rice products, leafy vegetables, and wheat flour and wheat products were identified as the primary sources of dietary lead exposure, accounting for 73.1%. The MOE values demonstrated the following tendency: younger age groups had lower MOEs, and 95% confidence ranges for the groups aged 3-6 and 7-17 began at 0.6 and 0.7, respectively, indicating the potential health risk of children, while those for other age groups were all above 1.0. Continued efforts are needed to reduce dietary lead exposure in Guangzhou.

Molecular Transmission Network and Drug Resistance in Treatment-Naive HIV-1-Infected Patients in the Liangshan District, China.

This study aimed to investigate the molecular transmission network and drug resistance in treatment-naive HIV-1-infected patients in the Liangshan District, China. The research subjects for this study were HIV-1-infected patients who did not receive any antiretroviral therapy (ART) in the Liangshan District between January 2022 and July 2023. Peripheral venous whole-blood samples were collected from the research subjects. Two milliliters of blood was used for CD4+ T lymphocyte counting detection. Ten milliliters of blood was centrifuged to separate the plasma and blood cells for quantitative detection of HIV-1 RNA and DNA and drug resistance testing of HIV-1. A total of 156 participants were included in this study (88 males and 68 females). The median age of the participants was 37 years. The findings revealed a positive correlation between the HIV-1 DNA and the HIV-1 RNA levels (r = 0.478, p < 0.001). However, a negative correlation was observed between the HIV-1 DNA levels and CD4+ T lymphocyte counts (r = -0.186, p = 0.020). Of the 156 participants, 145 were successfully tested for drug resistance of HIV-1 RNA and HIV-1 DNA simultaneously. Four cases failed the HIV-1 RNA drug resistance testing, and another two failed the HIV-1 DNA drug resistance testing. The most common HIV-1 subtype was the CRF07_BC recombinant. In this study, the overall incidence of transmitted drug resistance (TDR) was 8.33%. The resistance rates of non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI) were 7.69% and 0.64%, respectively. In addition, 32 participants were found to have drug-resistant mutations. The primary drug-resistant mutations were K103N, V179D, E157Q, and A128T, mainly against efavirenz (EFV) and nevirapine (NVP) resistance. The drug resistance of HIV-1-infected ART-naive patients in the Liangshan District cannot be ignored. HIV-1 drug resistance testing is recommended before initiating ART.

Unraveling the contribution of dietary intake to human phthalate internal exposure.

Human exposure to phthalates (PAEs) occurs primarily through diet, but the contribution of dietary exposure to the total internal exposure of PAEs has not been well studied. This work investigated the relationship between dietary exposure and human internal exposure to PAEs. Daily food samples were determined to evaluate the health risk of dietary exposure, and phthalate metabolites (mPAEs) were determined from urine samples of 360 volunteers of Guangzhou to assess their internal exposure. The total mPAEs concentration in the urine samples ranged from 8.43 to 1872 ng/mL, with mono-(2-ethylhexyl) phthalate (MEHP), mono-n-butyl phthalate (MnBP), and mono-isobutyl phthalate (MiBP) being the most predominant mPAEs. The concentration of PAEs in food ranged from n.d-40200 µg/kg, and benzyl butyl phthalate (BBzP), di-n-butyl phthalate (DnBP) and di-(2-ethylhexyl) phthalate (DEHP) were the most prevalent. PAE exposure was significantly associated with age, and children exhibited the highest concentration of mPAEs. Using Monte Carlo simulation to estimate PAE exposure's health risk eliminated uncertainties caused by single-point sampling and provided more reliable statistical results. The hazard quotient (HQ) was used to evaluate PAE exposure health risks. The results showed that 37% of the volunteers had HQ levels higher than 1 based on urinary mPAE concentrations, while 24% of the volunteers had HQ levels greater than 1 because of dietary exposure to PAEs. Dietary intake was the predominant exposure route for PAEs, and accounted for approximately 65% (24% out of 37%) of the cases where HQ levels exceeded 1. The work revealed the correlation between dietary external and internal exposure to PAEs, and further studies are needed to better understand the implications.

Probabilistic risk assessment of dietary exposure to pentachlorophenol in Guangzhou, China.

Pentachlorophenol (PCP) is a ubiquitous environmental contaminant commonly existing as its sodium salt (NaPCP), which enters the human body primarily through long term but low-level dietary exposure. PCP contributes to chemical carcinogenesis and teratogenesis. In this study, the probabilistic risk of dietary exposure to PCP in Guangzhou citizens was investigated. In total, 923 food samples in the categories of pork, livestock (beef and lamb), poultry, offal, eggs, and freshwater fish (considered to be relatively susceptible to PCP contamination) were collected from various markets in Guangzhou and tested for PCP. Probabilistic risk assessment model calculations for PCP dietary exposure and margin of exposure (MOE) values were performed using @RISK software, based on a Monte Carlo simulation with 10,000 iterations. The overall detection rate of PCP (above 1 µg kg-1, the detection limit) was 19.9% (184/923), with an average of 7.9 µg kg-1. The highest rate of PCP detection, 28.2%, was in livestock (beef and lamb). The MOE value for dietary PCP exposure in general Guangzhou residents averaged 400, which was far below 5,000 (the borderline for judging a health risk). The lowest MOE value, 190, was observed in the 3- to-6-year old population and indicates a significant risk. In conclusion, this study suggests that PCP exposure in Guangzhou residents is of considerable health risk, especially for the pre-school young children.

Dietary risk assessment of neonicotinoid pesticide in 21 kinds of market-sold vegetables in Guangzhou City / 预防医学

Objective@#To evaluate the dietary risk of neonicotinoid insecticides in market-sold vegetables in Guangzhou City, so as to provide insights into ensuring food safety for residents.@*Methods@#Forty-five samples of 21 kinds of vegetables were collected from supermarkets and farmer's markets in Guangzhou City from June to September in 2022, and 10 kinds of neonicotinoid insecticides were determined using liquid chromatography-mass spectrometry (LC-MS). The vegetable consumption was obtained through the survey of food consumption and nutrients intake of residents in Guangzhou City. The dietary risk was evaluated by calculating daily exposure and non-carcinogenic risk quotients of neonicotinoid insecticides. @*Results@#A total of 27 samples of vegetables were detected with neonicotinoid insecticides, and the detection rate was 60.00%. Among 10 kinds of neonicotinoid insecticides, 6 kinds were identified, including clothianidin, thiamethoxam, imidacloprid, acetamiprid, dinotefuranand and nitenpyram. The detection rates of clothianidin, thiamethoxam and imidacloprid were relatively high (26.67%, 11.11% and 6.67%), and some samples exceeded the standard, with the rate of 4.44%, 2.22% and 2.22%, respectively. The total exposure of neonicotinoid pesticides (IMIRPF) was 3 053.00 ng/g, and the contents and IMIRPF of imidacloprid were the highest in roots and tubers. The daily exposure of imidacloprid, acetamiprid, dinotefuran, clothianidin, thiamethoxam and nitenpyram was 34.58, 3.85, 1.20, 6.87, 7.19 and 0.86 ng/(kg·d). Non-carcinogenic risk quotients of imidacloprid, acetamiprid, dinotefuran, clothianidin, thiamethoxam and nitenpyram was 5.76×10-4, 0.55×10-4, 0.06×10-4, 0.69×10-4, 0.90×10-4 and 0.02×10-4, respectively, which was lower than 1; and the sum of non-carcinogenic risk quotients was 7.98×10-4, which was lower than 1. @*Conclusions@#The dietary risk of neonicotinoid pesticides is low in 21 kinds of market-sold vegetables in Guangzhou City; however, the contents of neonicotinoid insecticides in some vegetable samples exceed the standard. The supervision of vegetable markets should be strengthened.

Automatic detection of early gastric cancer in endoscopy based on Mask region-based convolutional neural networks (Mask R-CNN)(with video).

The artificial intelligence (AI)-assisted endoscopic detection of early gastric cancer (EGC) has been preliminarily developed. The currently used algorithms still exhibit limitations of large calculation and low-precision expression. The present study aimed to develop an endoscopic automatic detection system in EGC based on a mask region-based convolutional neural network (Mask R-CNN) and to evaluate the performance in controlled trials. For this purpose, a total of 4,471 white light images (WLIs) and 2,662 narrow band images (NBIs) of EGC were obtained for training and testing. In total, 10 of the WLIs (videos) were obtained prospectively to examine the performance of the RCNN system. Furthermore, 400 WLIs were randomly selected for comparison between the Mask R-CNN system and doctors. The evaluation criteria included accuracy, sensitivity, specificity, positive predictive value and negative predictive value. The results revealed that there were no significant differences between the pathological diagnosis with the Mask R-CNN system in the WLI test (χ2 = 0.189, P=0.664; accuracy, 90.25%; sensitivity, 91.06%; specificity, 89.01%) and in the NBI test (χ2 = 0.063, P=0.802; accuracy, 95.12%; sensitivity, 97.59%). Among 10 WLI real-time videos, the speed of the test videos was up to 35 frames/sec, with an accuracy of 90.27%. In a controlled experiment of 400 WLIs, the sensitivity of the Mask R-CNN system was significantly higher than that of experts (χ2 = 7.059, P=0.000; 93.00% VS 80.20%), and the specificity was higher than that of the juniors (χ2 = 9.955, P=0.000, 82.67% VS 71.87%), and the overall accuracy rate was higher than that of the seniors (χ2 = 7.009, P=0.000, 85.25% VS 78.00%). On the whole, the present study demonstrates that the Mask R-CNN system exhibited an excellent performance status for the detection of EGC, particularly for the real-time analysis of WLIs. It may thus be effectively applied to clinical settings.

Probabilistic Risk Assessment of Dietary Exposure to Chloramphenicol in Guangzhou, China.

Chloramphenicol has been used in veterinary medicine, where its residues can remain in food of animal origin, thus potentially causing adverse health effects. This facilitated the ban for its use in food-producing animals globally, but its residues have remained ubiquitous. In this study, food commodities possibly contaminated with chloramphenicol, including livestock meat, poultry, edible viscera, fish, shrimp and crab, molluscs, milk, and eggs, were collected from domestic retail shops in all the 11 districts of Guangzhou and tested for its residue. Probabilistic risk assessment model calculations for its dietary exposure, and the margin of exposure (displayed as mean values and 5th percentile to 95th percentile ranges) were performed by using @RISK software based on a Monte Carlo simulation with 10,000 iterations. The results indicated the detection of chloramphenicol in 248 out of 1454 samples (17.1%), which averaged to a level of 29.1 µg/kg. The highest average value was observed in molluscs (148.2 µg/kg, with the top value as 8196 µg/kg); meanwhile, based on the dietary structure of a typical Cantonese, pond fish, pork, and poultry meat contributed most (about 80%) to the residents' dietary exposure to chloramphenicol. The margin of exposure for dietary chloramphenicol exposure in Guangzhou residents was 2489, which was apparently below 5000 (the borderline for judging a health risk), particularly low in preschool children (2094, suggesting an increased risk). In conclusion, the study suggests that chloramphenicol exposure in Guangzhou residents is considerable, and its relevant health hazard, especially for preschool children, is worthy of further investigation.

MicroRNA-873 acts as a tumor suppressor in esophageal cancer by inhibiting differentiated embryonic chondrocyte expressed gene 2.

Esophageal cancer is one of the most common digestive malignant diseases worldwide and emerging evidences revealed that microRNAs (miRNAs) were implicated in the development and progression of esophageal cancer. However, the expression level and biological function of microRNA-873(miR-873) in esophageal cancer are still largely elusive. In this study, we investigated the expression and biological roles of miR-873 in human esophageal cancer. Our results revealed that miR-873 was significantly underexpressed in esophageal cancer tissues and cell lines when compared with the para-tumor tissue and primary human esophageal epithelial cells. Furthermore, overexpression of miR-873 could remarkably inhibit esophageal cancer cell growth, migration and invasion. Moreover, we validated differentiated embryonic chondrocyte expressed gene 2 (DEC2) as a direct target of miR-873 which could reverse the repressive effects of miR-873 on esophageal cancer cell. In summary, our investigation demonstrated that miR-873 was underexpressed in esophageal cancer and might act as a tumor suppressor gene by directly targeting DEC2.

Spatio-temporal analysis of the incidence of colorectal cancer in Guangzhou, 2010-2014.

INTRODUCTION: Colorectal cancer (CRC) is a common type of neoplasm. This study examined the spatio-temporal distribution of the CRC incidence in Guangzhou during 2010-2014. METHODS: Colorectal cancer incidence data were obtained from the Guangzhou Cancer Registry System. Spatial autocorrelation analysis and a retrospective spatio-temporal scan were used to assess the spatio-temporal cluster distribution of CRC cases. RESULTS: A total of 14,618 CRC cases were registered in Guangzhou during 2010-2014, with a crude incidence of 35.56/100,000 and an age-standardized rate of incidence by the world standard population (ASRIW) of 23.58/100,000. The crude incidence increased by 19.70% from 2010 (32.88/100,000) to 2014 (39.36/100,000) with an average annual percentage change (AAPC) of 4.33%. The AAPC of ASRIW was not statistically significant. The spatial autocorrelation analysis revealed a CRC incidence hot spot in central urban areas in Guangzhou City, which included 25 streets in southwestern Baiyun District, northwestern Haizhu District, and the border region between Liwan and Yuexiu Districts. Three high- and five low-incidence clusters were identified according to spatio-temporal scan of CRC incidence clusters. The high-incidence clusters were located in central urban areas including the border regions between Baiyun, Haizhu, Liwan, and Yuexiu Districts. CONCLUSIONS: This study revealed the spatio-temporal cluster pattern of the incidence of CRC in Guangzhou. This information can inform allocation of health resources for CRC screening.

Evolution of Cancer Registration Combining Online Reporting with Follow-up in the Community: Practices in Guangzhou, China

Background: An efficient registration system with accurate and timely information on cancer incidence and mortality is key to development of policies to prevent and control cancer. A traditional registration system usually needs 3-4 years to collect data and publish a cancer report. However, researchers, policymakers and healthcare professionals need to know the latest cancer registration data quickly. Methods: A computer system has been operating with cases reported online by hospitals and followed up in communities at the Cancer Registry of Guangzhou (CRG) since 2008. The comparability, completeness, accuracy and timeliness of collected data were here evaluated. Results: From 2010 to 2014, 181,194 cancer cases from 1,916,253 medical records of cancer were reported to the CRG online. 53,473 cases were deleted as duplicates (47,906), wrong diagnoses (410) or residents of other places (5,157) during the follow up. Successful final follow-up rates were over 90% for both newly and previously diagnosed cases by general practitioners in community clinics. The CRG coding and classification system follows international standards. The annual trends for all sites by sex were stable from 2010 to 2014. All age-specific incidence rates for childhood cancers were within the limits of the respective international references. The overall M:I ratio for all sites but C44 was 56.7%.,ratios for most sites in Guangzhou being between Hong Kong and Shanghai. A total of 75.7% of the cancer cases reported in 2010­2012 were morphologically verified. Ninety five percent of new cases completed registration within 29.0 months in 2010, reducing to 8.0 months in 2014. Conclusion: The online report system with community follow up at the CRG yields reasonably accurate and close-to-complete data. It takes less time to confirm diagnosis and other information so that reporting annual incidence one year after the close of registration becomes possible.

[A 1:1 matched case-control study on the interaction between HBV, HCV infection and DNA repair gene XPC Ala499Val, Lys939Gln for primary hepatocellular carcinoma].

OBJECTIVE: To evaluate the interaction between environmental factors, HBV/HCV infections and DNA repair gene XPC exon 8 Ala499Val, exon 15 Lys939Gln on related risks to primary hepatocellular carcinoma (PHC). METHODS: A 1:1 matched case-control study was conducted in Shunde city, Guangdong province. The genotypes of Ala499Val and Lys939Gln were detected by polymerase chain reaction restrictive fragment length polymorphism (PCR-RFLP) analysis, and gene-environment interactions were analyzed by conditional logistic regression. RESULTS: Among people infected by HBV with non- or at least one mutant gene of Ala499Val carriers, the risk of PHC significantly increased, with ORs as 3.768 (95%CI: 1.137 - 12.485) and 3.667(95%CI: 1.122 - 11.981) respectively. With non- or at least one mutant gene of Lys939Gln, the risk was increasing with ORs as 6.778 (95%CI: 2.025 - 22.688) and 3.152 (95%CI: 1.062 - 9.351) respectively. In those with HCV infection, non- or at least one mutant gene of Ala499Val might increase the risk with ORs as 2.955 (95%CI: 0.587 - 14.869), 1.085(95%CI: 0.307 - 3.839) respectively. However, when compared to the ones with no mutant gene of Lys939Gln among the same research subjects, those carrying at least one gene may decrease the risk, with OR lowered from 4.197 (95%CI: 0.870 - 20.243) to 0.887 (95%CI: 0.228 - 3.448). But the interactions between HBV infection, HCV infection and XPC genes were not statistically significant. CONCLUSION: Among people infected by HCV, the mutant gene of Ala499Val had the tendency to lower the risk of PHC, and the mutant gene of Lys939Gln also appeared the same in the population with either HBV infection or HCV infection in Shunde, Guangdong. Another study with large samples should be performed to analyze the interactions among environments-genes.

Kinetics of the H2O2-dependent ligninase-catalyzed oxidation of veratryl alcohol in the presence of cationic surfactant studied by spectrophotometric technique.

The kinetics of ligninase-catalyzed oxidation of veratryl alcohol (VA) by H(2)O(2) in the aqueous medium containing cationic surfactant cetyltrimethylammonium bromide (CTAB) has been investigated using spectrophotometric technique. Steady-state kinetic studies at different concentrations of CTAB indicate that the reaction follows a ping pong mechanism and the mechanism always holds but the kinetic parameters vary with CTAB concentrations. CTAB is a weak inhibitor for ligninase; it lowers the maximum initial velocity. CTAB also causes the Michaelis constant of H(2)O(2) to decrease dramatically and that of VA to increase markedly. Based on the changes in kinetic parameters of the enzyme-catalyzed reaction at different CTAB concentrations (lower than, near to and larger than its critical micelle concentration) and the effects of the CTAB monomer and the micelles on the spectra of VA and its corresponding aldehyde, a conclusion could be made that modification of the enzymatic protein by the surfactant monomer should be responsible for the above-mentioned results.