[Research on the standard limits for vinyl chloride and trichloroethylene in the "Standards for Drinking Water Quality（GB5749-2022）" in China]

The usage of vinyl chloride and trichloroethylene in China has been increasing year by year, and they have been detected in both drinking water and environmental water, making them important environmental pollutants. Based on the latest research results on the health effects of vinyl chloride and trichloroethylene, the newly issued, "Standards for Drinking Water Quality (GB5749-2022)" in China has adjusted the standard limit of vinyl chloride from 0.005 mg/L to 0.001 mg/L and the standard limit of trichloroethylene from 0.07 mg/L to 0.02 mg/L. This article analyzed and discussed the relevant technical contents for determining the above standard limits, including the levels and exposure conditions of vinyl chloride and trichloroethylene in the water environment, health effects, derivation of safety reference values, and determination of hygiene standard limits. Suggestions were also made for the implementation of this standard.

[Research on the determination of the limit value of perchlorate in the "Standards for Drinking Water Quality（GB5749-2022）" in China]

Perchlorate is an environmental pollutant that has been a focus of attention in recent years. It has been detected in many environmental water bodies and drinking water in China, with a high level of presence in some areas of the Yangtze River Basin. The human body may ingest perchlorate through exposure pathways such as drinking water and food, and its main health effect is to affect the thyroid's absorption of iodine. The "Standards for Drinking Water Quality" (GB5749-2022) includes perchlorate as an expanded indicator of water quality, with a limit value of 0.07 mg/L. This article analyzes the technical content related to the determination of hygiene standard limits for perchlorate in drinking water, including the environmental presence level and exposure status of perchlorate, main health effects, derivation of safety reference values, and determination of hygiene standard limits.

[Methodological study on the establishment of limit values in the Standards of Drinking Water Quality]

The establishment of limit values for standards of drinking water quality is an important and complex process. This study systematically introduced the methodology of the establishment of standard limit values for drinking water quality and elaborated on the workflow of setting limit values of water quality indicators, principles and methods of selecting water quality indicators, derivation of safety reference values, and establishment of limit values. It also aimed to provide reference and support for the future revision of relevant standards.

[A monogenic lupus family caused by homozygous deletions of DNASE1L3 gene and literature review]

Objective: To report the clinical features and genetic variations of monogenic lupus caused by DNASE1L3 deficiency and to introduce preliminary experience on diagnosis and treatment for this disease. Methods: Clinical data of 3 children from the same pedigree were collected who were diagnosed with DNASE1L3 defect-associated monogenic lupus in August 2020 by Department of Pediatrics, Peking Union Medical College Hospital referred from Department of Pediatrics, Boai Hospital of Zhongshan. DNA was extracted from the peripheral blood of the patients and their parients to perform genetic analysis and confirmation. Six interferon-stimulated genes were relatively quantified to examine the activation of the type I interferon signaling. "DNASE1L3" "systemic lupus erythematosus" and "SLE" were searched in PubMed, Wangfang Data, CNKI databases for related reports from database established date to June 2022. Spectrum of genetic variations and clinical phenotypes were analyzed in combination with this pedigree. Results: Case 1, a 14-year-old girl with edema, hematuria, and heavy proteinuria, presented with membranous nephropathy. Case 2, the 12-year-old younger brother of case 1 with hematologic, cardiac, pulmonary, renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody and low complement C3, manifested with systemic lupus erythematosus. Case 3, the 8-year-old younger sister of case 1 with hematologic, cardiac, pulmonary and renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody, and low complement C3 and C4, manifested with systemic lupus erythematosus. Genetic testing revealed that all 3 patients carried homozygous deletions in exons 3 and 4 on DNASE1L3 gene. Interferon scores were elevated in case 1, 2 and their parents but normal in case 3. All 3 patients were diagnosed with monogenic lupus caused by DNASE1L3 defects. Literature searching identified 10 relevant publications in English and 0 publication in Chinese, involving 42 patients from 18 pedigrees (including the 3 cases from this pedigree). Nine variants were found: c.289_290delAC (p.T97Ifs*2), c.643delT (p.W215Gfs*2), c.320+4delAGTA, c.321-1G>A, Ex5 del, c.433G>A, c.581G>A (p.C194Y), c.537G>A (p.W179X), and Ex3-4 del. The hotspot variants were c.643delT (43% (36/84)) and c.289_290delAC (36% (30/84)). Kidney was affected in 31 cases (74%) of the 42 cases. Among the 25 patients, joints were affected in 16 cases (64%), fever were reported in 13 cases (52%) hematologic system was involved 13 cases (52%), rash was present in 10 cases (40%), intestinal tract was involved in 8 cases (32%), lungs were involved in 6 cases (24%), eyes were involved in 4 cases (16%), and the heart was involved in 4 cases (16%). The 2 cardiopulmonary affected patients from literature showed poor prognosis, with 1 died, and 1 right heart failure. Conclusions: The clinical manifestations of monogenic lupus caused by DNASE1L3 defect are highly heterogenous, primarily with renal, blood, joint, intestinal, and cardiopulmonary involvement. There is no correlation between the genotype and the phenotype. DNASE1L3 defects were predominantly mediated by null varations including nonsense, splicing, frameshift and exon deletions. The hotspot variants are c.643delT and c.289_290delAC. DNASE1L3 defects should be cautioned in early-onset lupus-like patients with renal, joint and hematologic involvement. Cardiopulmonary involved patients require close monitoring for poor prognosis. Copy number variations should be carefully analyzed after negative whole exome sequencing.

[Influencing factors of Legionella reproduction in secondary water supply operation and management]

Objective: To analyze the pollution status and influencing factors of Legionella pneumophila in a secondary water supply facility in a city. Methods: From June to August 2020, a survey on the level of Legionella pneumophila in secondary water supply unit was carried out in a city in northern China, and 304 sets of secondary water supply facilities were included in the study. A total of 760 water samples were collected from the inlet and outlet water of the secondary water supply facilities and some water samples in the water tank were collected for the detection of Legionella pneumophila, standard plate-count bacteria and related physical and chemical indicators. Through questionnaire survey, the basic information of secondary water supply facilities and daily management of water quality were collected. Multivariate logistic regression model was used to analyze the influencing factors of Legionella pneumophila contamination. Results: Among 304 sets of secondary water supply facilities, most of them were located in residential buildings [57.24% (174/304)]. High and low water tank water supply, low water tank variable frequency conversion water supply and non-negative pressure water supply accounted for 26.6% (81/304), 36.8% (112/304) and 36.5% (111/304), respectively. About 25.7% of facilities (78/304) were positive for Legionella pneumophila. Among them, the positive rates of Legionella pneumophila in high and low water tank water supply, low water tank variable frequency conversion water supply and non-negative pressure water supply facilities were 38.3% (31/81), 29.5% (33/112) and 12.6% (14/111), respectively. The results of multivariate logistic regression model analysis showed that the disinfectant residue could reduce the risk of Legionella pneumophila contamination in water samples, and the OR (95%CI) value was 0.083 (0.022-0.317). The increase of the standard plate-count bacteria and conductivity might increase the risk of Legionella pneumophila contamination in water samples. The OR (95%CI) values were 3.160 (1.667-5.99) and 1.004 (1.001-1.006), respectively. Compared with the non-negative pressure water supply, the risk of Legionella pneumophila contamination of secondary water supply facilities was increased by water supply from high and low water tanks and variable frequency conversion water supply from low water tanks, with OR (95%CI) values of 4.296 (2.096-8.803) and 2.894 (1.449-5.782), respectively. Conclusion: The positive rate of Legionella pneumophila in secondary water supply in the study city is high. Disinfectant residue, conductivity and method of water supply are associated with the positive rate of Legionella pneumophila.

[Mechanism of cleft palate in C57BL/6N mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin]

Objective: To explore the molecular mechanism of cleft palate in mice induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). Methods: The pregnant mice were randomly divided into TCDD-treated group (n=42) and control group (n=42). TCDD-treated group was given by gavage a single dose of TCDD (64 μg/kg) at 8: 00 AM on gestation day 10 (GD10) and the control group was given by gavage the isopyknic corn oil. At GD13-GD15, the fetal mice palate development was observed by HE staining. The mouse embryonic palatal mesenchymal cell proliferation was detected by 5-bromo-2-deoxyuridine (BrdU) immunofluorescence. The localization and expression of maternally expressed gene3 (MEG3) in mouse embryonic palatal mesenchymal cells was detected by situ hybridization and real-time PCR (RT-PCR). The key protein expressions of transforming growth factor-β (TGF-β)/Smad signaling pathway in mouse embryonic palatal mesenchyme were analyzed by Western blotting. The interaction of MEG3 and TGF-β receptor Ⅰ (TGF-βRⅠ) was examined by RNA binding protein immunoprecipitation (RIP). Results: At GD13 and GD14, compared with the control group, the ratio of BrdU-positive cells in the palatal mesenchyme of TCDD-treated fetuses decreased significantly (GD13, t=6.66, P=0.003; GD14, t=6.56, P=0.003). However, at GD15, the ratio of BrdU-positive cells was significantly increased (t=-5.98, P=0.004). MEG3 was mainly expressed in the nuclei of fetal mouse palatal mesenchymal cells, and the expression of MEG3 in TCDD group was significantly increased at GD13, GD14 and GD15(GD13, t=39.28, P=0.012; GD14, t=18.75, P=0.042; GD15, t=28.36, P=0.045). At GD14, TCDD decreased the levels of p-Smad2 and Smad4 in embryonic palate mesenchymal cells (p-Smad2, t=9.48, P=0.001;Smad4, t=63.10, P=0.001), whereas the expression of Smad7 was significantly increased at GD14 (t=30.77, P<0.001). The results of the RIP experiment showed that the amount of TGF-βRⅠ-bound MEG3 in mouse embryonic palatal mesenchymal cells in the TCDD group (23.940±1.301) was higher than that in the control group (8.537±1.523)(t=24.55, P<0.001). Conclusions: MEG3 is involved in the suppression of mouse embryonic palatal mesenchymal cell proliferation, functioning at least in part via interacting with the TGF-βRⅠ protein and thereby suppressing Smad signaling in the context of TCDD induced cleft palate.

[Clinical outcome of single posterior implant-supported monolithic zirconia crowns fabricated using full digital workflow and conventional workflow: a 3-year follow-up]

Objective: To compare the clinical performance of posterior single implant-supported monolithic zirconia crowns fabricated by full digital workflow and that of those fabricated by conventional workflow. Methods: This is prospective clinical research. Thirty-five patients who participated in a previous study during August 2017 to October 2018 at Department of Prosthodontics, Peking University School and Hospital of Stomatology were included in this 3-year follow-up study. The 35 patients, 17 females and 18 males, aged (49.0±15.4) years (24-86 years old), was allocated into two groups. In the full digital workflow group, intraoral scanning was taken immediately after implant placement, and a full zirconia implant crown was fabricated using model-free computer aided design/computer aided manufacturing (CAD/CAM) procedure (n=14). In the conventional group, a conventional impression was taken 3 months after implant placement and the stone model was produced. A full zirconia implant crown was fabricated using conventional model-based procedure (n=21). Three years following crown delivery, all the prostheses were evaluated in the aspect of color, surface roughness, contour and marginal integrity using modified US Public Health Service criteria (MUSPHS criteria). The soft and hard tissue around implant was evaluated using modified plaque index, probing depth (PD), number of implants with bleeding on probing, marginal bone loss (MBL). The biological and mechanical complication were also recorded. Statistical analysis was performed using independent samples t test, Mann-Whitney U test and Fisher's exact test. Results: The total survival rate of prosthesis and implant was 100% (35/35). No significant difference in MUSPHS criteria ratings on color, surface roughness, contour and marginal integrity of these crowns were found between the full digital workflow group and the conventional group (P>0.05). Sixteen out of the 35 crowns had a contour score of B due to loss of interproximal contact. Ten out of the 35 crowns had the screw hole sealing resin sinking or falling off, four in the full digital workflow group and six in the conventional group. There was no significant difference in the rate of prostheses mechanical complications between the two groups (P=1.000). For all the implants, there was no significant difference in MBL, PD, the modified plaque index, and number of implants with bleeding on probing between the two groups (U=119.50,133.00,142.50, t=-0.53, P>0.05). Conclusions: The clinical performance of implant-supported posterior single monolithic zirconia crowns fabricated by full digital workflow was stable. There was no significant difference in the clinical performance of the single implant crowns between the full digital workflow group and the conventional group.

Modulation of Multiple Signaling Pathways of the Plant-Derived Natural Products in Cancer

Natural compounds are highly effective anticancer chemotherapeutic agents, and the targets of plant-derived anticancer agents have been widely reported. In this review, we focus on the main signaling pathways of apoptosis, proliferation, invasion, and metastasis that are regulated by polyphenols, alkaloids, saponins, and polysaccharides. Alkaloids primarily affect apoptosis-related pathways, while polysaccharides primarily target pathways related to proliferation, invasion, and metastasis. Other compounds, such as flavonoids and saponins, affect all of these aspects. The association between compound structures and signaling pathways may play a critical role in drug discovery.

Liquiritin induces apoptosis and autophagy in cisplatin (DDP)-resistant gastric cancer cells in vitro and xenograft nude mice in vivo

Gastric cancer is reported as one of the leading factors resulting in tumor-related death worldwide. However, the therapies to suppress gastric cancer are still limited and the emergence of drug resistance makes it necessary to develop new and effective anticancer drugs and combinational chemotherapy schemes. Liquiritin (LIQ) is a major constituent of Glycyrrhiza Radix, exhibiting various pharmacological activities, including anticancer. In this study, we investigated the role of LIQ in human gastric cancer cells with cisplatin (DDP) resistance. The findings suggested that LIQ, when applied in single therapy, could moderately inhibit the proliferation and migration of DDP-resistant gastric cancer cells, SGC7901/DDP. DDP and LIQ in combination induced G0/G1 cell cycle arrest to suppress the proliferation of gastric cancer cells, which were associated with the decrease of cyclin D1, cyclin A and cyclin-dependent kinase 4 (CDK4) and increase of p53 and p21. In addition, LIQ combined with DDP significantly induce apoptosis and autophagy both in vitro and in vivo through enhancing cleavage of caspase-8/-9/-3 and PARP, as well as LC3B and Beclin 1 expression. Significantly, the two drugs, when used in combination, prevented gastric cancer cell xenografts in nude mice in vivo. Together, the results revealed that application of DDP and LIQ in combination possessed a potential value against the growth of human gastric cancer with DDP resistance.

Preliminary in vitro analysis of mechanism of cardiac microvascular endothelial barrier function

To preliminarily clarify the mechanism of cardiac microvascular endothelial barrier function leading to heart failure, primary HMVEC-D cells were selected and cultured for amplification. The cells were infected with adenovirus vector containing the ADP-ribosylation factor 6 (Arf6) Q67L gene. Full-length and functional fragments of myeloid differentiation primary response 88 and ARF nucleotide-binding site opener genes were established and transfected into HEK293T cells. GTP-Arf6 pull-down experiment, fluorescent quantitative real-time PCR, immuno-coprecipitation, and transendothelial electrical resistance analysis were conducted. Interleukin-1β (IL-1β) induced increase in vascular permeability, whereas inhibitor SC514 blocked IL-1β-induced transfer of nuclear factor-κB into the nucleus, from the cytoplasm. Increase in amount of activated Arf6 promoted reduction in transendothelial electrical resistance. In addition, SecinH3 significantly inhibited increase in vascular permeability, and the progression of heart failure was significantly relieved. Cardiac microvascular endothelial barrier function can lead to heart failure. However, IL-1β induced increase in vascular permeability, which nullified the function of cardiac microvascular endothelial barrier. These findings are closely related to the activation of the Arf6-VE-cadherin signaling pathway.

Colonic polyps: application value of computer-aided detection in computed tomographic colonography

BACKGROUND

Colonic polyps are frequently encountered in clinics. Computed tomographic colonography (CTC), as a painless and quick detection, has high values in clinics. In this study, we evaluated the application value of computer-aided detection (CAD) in CTC detection of colonic polyps in the Chinese population.

METHODS

CTC was performed with a GE 64-row multidetector computed tomography (MDCT) scanner. Data of 50 CTC patients (39 patients positive for at least one polyp of ≥ 0.5 cm in size and the other 11 patients negative by endoscopic detection) were retrospectively reviewed first without computer-aided detection (CAD) and then with CAD by four radiologists (two were experienced and another two inexperienced) blinded to colonoscopy findings. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detected colonic polyps, as well as the areas under the ROC curves (Az value) with and without CAD were calculated.

RESULTS

CAD increased the overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the colonic polyps detected by experienced and inexperienced readers. The sensitivity in detecting small polyps (5 - 9 mm) with CAD in experienced and inexperienced readers increased from 82% and 44% to 93% and 82%, respectively (P > 0.05 and P < 0.001). With the use of CAD, the overall false positive rate and false negative rate for the detection of polyps by experienced and inexperienced readers decreased in different degrees. Among 13 sessile polyps not detected by CAD, two were ≥ 1.0 cm, eleven were 5 - 9 mm in diameter, and nine were flat-shaped lesions.

CONCLUSIONS

The application of CAD in combination with CTC can increase the ability to detect colonic polyps, particularly for inexperienced readers. However, CAD is of limited value for the detection of flat polyps.

Transmission disequilibrium analysis of the GSN gene in a cohort of family trios with schizophrenia

Apoptosis is thought to play a role in neuronal pathology in schizophrenia. Recently, the GSN gene was reported to have anti-apoptotic properties. In a genome-wide expression analysis on schizophrenia, GSN was also found to be significantly down-regulated in schizophrenia. All the hints suggest that GSN is a novel candidate gene in occurrence of schizophrenia. In this work, we genotyped 3 SNPs around the GSN locus in 493 sets of the Han Chinese trio sample using allele-specific PCR. A weak association or a marginally positive result was detected (0.05 for P-value of the overtransmitted haplotype and 0.02 for a global P-value).

[A clinical investigation into the effect of comfort denture adhesive on masticatory function with complete dentures]

OBJECTIVE

The purpose of this study was to evaluate the clinical effect of the new developed form of Comfort denture adhesive (Comfort DA).

METHODS

10 edentulous patients with complete dentures were selected for this study. The maximum biting force and masticatory efficiency were recorded before and after application of the adhesive to all the new and old dentures. Subjective test was also used to evaluate this adhesive in enhancing retention and stability of complete denture using the questionnaire way.

RESULTS

The data indicated that significantly greater biting forces were generated with old dentures than with the new dentures. The major findings were that the adhesive produced a statistically significant improvement in the masticatory efficiency after application. Subjective views of the patients indicated that this tested product significantly improved denture retention, stability and had other favorable features. The time of adhesion was about 6 8 hours.

CONCLUSION

The generally favorable clinical performance of the developed Comfort DA formulation indicated that it might be an efficacious denture adhesive.

[STR polymorphisms in five Chinese ethnic groups(2)]

Population genetic studies were performed in Chinese Han, Hui, Mongolian, Tibetan and Uygur. Allele frequency distributions were analyzed for ten loci, i.e., D3S1358, VWA, CSF1PO, FGA, THO1, TPOX, D5S818, D13S317 and D7S820 by GeneScan. The results showed that there were 60 STR alleles and 149 genotypes in Han; 63 STR alleles and 144 genotypes in Hui; 69 STR alleles and 173 genotypes in Mongolian; 77 STR alleles and 168 genotypes in Tibetan; 70 STR alleles and 148 genotypes in Uygur. Significant differences were identified among ethnic groups (African-American, US-Caucasian and Chinese-Oriental), but similarity was found among the five Chinese populations, and immunogenomics and pharmacogenomics studied in this report. These findings indicated that the nine STR loci and amelogenin locus were very useful for individual identification in forensic science.

[Anti-inflammatory and anti-bacterial functions of bezoar antipyretic tablets]

Bezoar Antipyretic Tablets can inhibit markedly acute exudative inflammation. It can also inhibit markedly drug-resistant Staphylococcus aureus, etc. It has no influence on Bacillus pyocyaneus, etc.