Evolution of neutralizing antibodies and cross-activity against different variants of SARS-CoV-2 in patients recovering from COVID-19

BACKGROUND

Patients recovering from COVID-19 may need vaccination against SARS-CoV-2 because acquired immunity from primary infection may wane, given the emergence of new SARS-CoV-2 variants. Understanding the trends of anti-spike IgG and neutralizing antibody titers in patients recovering from COVID-19 may inform the decision made on the appropriate interval between recovery and vaccination.

METHODS

Participants aged 20 years or older and diagnosed with COVID-19 between January and December, 2020 were enrolled. Serum specimens were collected every three months from 10 days to 12 months after the onset of symptom for determinations of anti-spike IgG and neutralizing antibody titers against SARS-CoV-2 Wuhan strain with D614G mutation, alpha, gamma and delta variants.

RESULTS

Of 19 participants, we found a decreasing trend of geometric mean titers of anti-spike IgG from 560.9 to 217 and 92 BAU/mL after a 4-month and a 7-month follow-up, respectively. The anti-spike IgG titers declined more quickly in the ten participants with severe or critical disease than the nine participants with only mild to moderate disease between one month and seven months after SARS-CoV-2 infection (-8.49 vs - 2.34-fold, p < 0.001). The neutralizing activity of the convalescent serum specimens collected from participants recovering from wild-type SARS-CoV-2 infection against different variants was lower, especially against the delta variants (p < 0.01 for each variant with Wuhan strain as reference).

CONCLUSION

Acquired immunity from primary infection with SARS-CoV-2 waned within 4-7 months in COVID-19 patients, and neutralizing cross-activities against different SARS-CoV-2 variants were lower compared with those against wild-type strain.

[Bacterial community diversity in Dermatophagoides farinae using high-throughput sequencing]

OBJECTIVE

To investigate the bacterial community diversity in Dermatophagoides farinae.

METHODS

Laboratory-cultured D. farinae was collected, and the composition of microbial communities was determined by sequence analyses of the V4 region in the bacterial 16S ribosomal RNA (16S rRNA) gene on an Illumina PE250 high-throughput sequencing platform. Following quality control and filtering of the raw sequence files, valid reads were obtained and subjected to operational taxonomic units (OTU) clustering and analysis of the composition of microbial communities and alpha diversity index using the Usearch software, Silva database, and Mothur software.

RESULTS

A total of 187 616 valid reads were obtained, and 469 OTUs were clustered based on a sequence similarity of more than 97%. OTU annotation showed that the bacteria in D. farinae belonged to 26 phyla, 43 classes, 100 orders, 167 families and 284 genera. The bacteria in D. farinae were mainly annotated to five phyla of Proteobacteria, Firmicutes, Bacteroidota, Actinobacteriota, and Acidobacteriota, with Proteobacteria as the dominant phylum, and mainly annotated to five dominant genera of Ralstonia, norank-f-Mitochondria, Staphylococcus and Sphingomonas, with Wolbachia identified in the non-dominant genus.

CONCLUSIONS

A high diversity is identified in the composition of the bacterial community in D. farinae, and there are differences in bacterial community diversity and abundance among D. farinae.

[A cross-sectional study of prevalence of chronic kidney disease and related factors in adults in Anhui province]

Objective: To understand the prevalence of chronic kidney disease (CKD) and related factors in adults in Anhui province based on the data of Chinese Chronic Diseases and Nutrition Surveillance program (2018) in Anhui. Methods: Multi-stage stratified cluster random sampling was used to select participants aged ≥18 years. Moreover, questionnaire survey, body measurements and laboratory tests were conducted. The complex weighting method was used to estimate the prevalence of CKD in residents with different characteristics, and complex sampling data logistic regression model was used for multivariate analysis to identify related risk factors. Results: A total of 7 181 participants were included. The overall prevalence of CKD was 11.06% in adults in Anhui, and the prevalence was 12.49% in women and 9.59% in men (P<0.05). The moderate, high and very high risk for CKD progression were 8.66%, 2.02% and 0.38%, respectively. Multivariate analysis showed that age (OR=1.03, 95%CI: 1.00-1.05), BMI (OR=1.05, 95%CI: 1.01-1.09), being woman (OR=1.38,95%CI: 1.22-1.55), hypertension (OR=2.50, 95%CI: 1.76-3.56), diabetes (OR=2.28, 95%CI: 1.51-3.43), dyslipidemia (OR=1.26, 95%CI: 1.11-1.43) and hyperuricemia (OR=2.16, 95%CI: 1.68-2.78) were risk factors for CKD. Conclusion: The prevalence of CKD in adults in Anhui was relatively high and age, gender, BMI, hypertension, diabetes, dyslipidemia and hyperuricemia were found to be associated with the prevalence of CKD. To prevent CKD and its complications, attention should be paid to the management of related risk factors, including overweight and obesity, hypertension, diabetes, dyslipidemia and hyperuricemia.

[A prospective cohort study on socioeconomic status and risk of all-cause mortality among patients with type 2 diabetes based on latent class analysis]

Objective: To investigate the relationship between socioeconomic status (SES) and all-cause mortality in patients with type 2 diabetes. Methods: A total of 17 553 patients with type 2 diabetes were recruited under the National Basic Public Health Service Project in Changshu county, Qingjiangpu district, and Huai'an district in Huai'an city of Jiangsu province as participants. Latent class analysis was applied to classify the individuals based on five socioeconomic indicators. Then, Cox proportional hazards regression models were used to estimate the associations of different levels of SES with all-cause mortality, and stratified analysis was performed according to age and area. Results: Among 100 529.08 person-years of the fo1low-up, the median follow-up time was 5.7 years, and 1 829 deaths occurred during the follow-up period. According to the relevant results of the latent class model, the model of the "three classes" was the best. The related population was then divided into low SES (8 256 people, 47.0%), medium SES (4 427 people, 25.2%), and high SES groups (4 870 people, 27.8%). Compared to patients with high SES, the multivariate-adjusted hazard ratio (95%CI) of all-cause mortality associated with low SES for males and females were 1.84 (1.53-2.21) and 1.41 (1.51-1.72), respectively. Stratified analysis showed that the hazard ration (95%CI) of all-cause mortality associated with low SES for males and females were 1.99 (1.12-2.95) and 2.01 (1.20-3.23), respectively, in people younger than 60 years old, and were 1.90 (1.57-2.31) and 1.40 (1.13-1.73) in people over 60 years old. The HR values (95%CI) for all-cause mortality associated with low SES for the male and females were 1.54 (1.17-2.04) and 1.27 (1.02-1.59) in the urban population with 2.11 (1.55-2.85) and 2.64 (1.17-3.35) in rural population, respectively. Conclusions: Lower SES increased the risk of all-cause mortality in type 2 diabetic patients, which is more significant in younger and rural populations.

Deep Underground Laboratory Measurement of ^{13}C(α,n)^{16}O in the Gamow Windows of the s and i Processes

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

Matrix metalloproteinase-7 promotes chronic kidney disease progression via the induction of inflammasomes and the suppression of autophagy

Deposition of extracellular matrix (ECM), epithelial-mesenchymal transition (EMT) and inflammation are crucial processes in chronic kidney disease (CKD) progression. The matrix metalloproteinases (MMPs) belong to a major enzyme group of proteinases that are involved in ECM degradation. MMP controls multiple biological processes, such as cell proliferation, EMT and apoptosis. The present study identified the roles of MMP7 in CKD progression. We demonstrated the transcriptional profiles of MMPs in kidney tissues of CKD patients in the Gene Expression Omnibus (GEO) data repository. MMP7 mRNA level was markedly upregulated in kidney tissues of CKD patients. MMP7 overexpression activated the NLRP3 and NLRP6 inflammasomes and increased fibrosis-related proteins in kidney cells. MMP7 inhibited oxidative stress-induced apoptosis and rapamycin-induced autophagy. We found that MMP7 expression in the kidney was increased in various CKD animal models. Knockdown of MMP7 affected renal function and renal fibrosis in a folic acid-induced CKD model. The inhibition of MMP7 decreased fibrosis and NLRP3 and NLRP6 inflammasomes and induced autophagy in kidney tissues. Taken together, these results provide insight into targeting MMP7 as a therapeutic strategy for CKD.

[The assistant effects of porcine fibrin sealant in improving stone clearance rate in flexible ureteroscopy lithotripsy in ex vivo porcine kidney model]

Objectives: To investigate the feasibility of using a porcine fibrin sealant to wrap and remove kidney calculi fragments through an isolated porcine kidney model. Methods: In the isolated porcine kidney stone model (implanted with 100 mg, air dried, ≤1 mm human stone fragments, n=6;implanted with 100 mg, air dried, ≤3 mm human stone fragments, n=6), the ureteral soft mirror combined with the 12/14Fr UAS was used to test the effect of stone extraction using only two stone extraction methods: basket extraction (control group, ≤1 mm stone fragments, n=3; ≤3 mm stone fragments, n=3) and basket-sealant extraction (test group, ≤1 mm stone fragments, n=3; ≤3 mm stone fragments, n=3). Compare the stone removal rate and operation time of the two stone retrieval methods. The sealant was put into urine of normal human and observed. Results: Porcine Fibrin Sealant can form a gel in saline and urine and adhere and wrap stone fragments. The time of procedures of test (basket-sealant) and control (basket) group in kidneys implanted with ≤ 1 mm stone fragments were (14.0±4.2) and (29.0±0.7)min (P<0.05) stone clearance rates were (90.9±1.4)% and (48.4±15.7)% (P<0.05), respectively. In kidneys implanted with ≤ 3 mm fragments, time of procedures were (12.8±4.0) and (30.0±0)min (P<0.05) Stone clearance rates were (91.1±5.0)% and (20.7±8.0)% (P<0.05). The Sealant dissolves by itself in normal human urine and normal saline at 37 ℃ for 24 hours. Conclusion: The appropriate concentration of Porcine Fibrin Sealant assisted stone retrieval may become a new method for removing small stone fragments in retrograde intrarenal surgery.

[Influence of systemic diseases on the diagnosis and treatment of dental diseases and prevention of related risks]

Patients with dental problems may suffer from various systemic diseases at the same time. The concomitant systemic diseases can have impacts and risks on the diagnosis, treatment planning and therapeutic practice in dentistry. The author briefly expounds the influences of systemic diseases on dental diagnosis and treatment and the prevention of risks from seven aspects: cardio-cerebral vascular system, blood system, respiratory system, endocrine system, digestive system, genitourinary system, nervous system and mental system, in order to provide references for the dental clinicians.

[Consensus of experts on the oral health management and medical risk prevention for the patients with chronic airway diseases (2022 edition)]

Today, there is greater awareness on the association between oral diseases and respiration diseases after the outbreak of COVID-19. However, confusion regarding the oral health management and medical risk prevention for patients with chronic airway diseases has been remained among dental clinicians. Therefore, the dental experts of the Fifth General Dentistry Special Committee, Chinese Stomatological Association, combined with the experts of respiratory and critical care medicine, undertook the formation of consensus on the oral health management of patients with chronic airway diseases in order to help dental clinicians to evaluate medical risks and make better treatment decision in clinical practice. In the present consensus report, the relationship of oral diseases and chronic airway diseases, the oral health management and the treatment recommendations of patients with chronic airway diseases are provided.

[Consensus of experts on the medical risk prevention for the patients with cardiovascular diseases during dental treatment (2022 edition)]

With the aging process of population in the society, the prevalence of cardiovascular diseases (CVD) in China is increasing continuously and the number of dental patients with CVD is increasing gradually too. Due to the lack of guidelines for dental patients with CVD in our country, how to implement standardized preoperative evaluation and perioperative risk prevention remains a problem to be solved for dentists at present. The present expert consensus was reached by combining the clinical experiences of the expert group of the Fifth General Dentistry Special Committee, Chinese Stomatological Association and respiratory and cardiology experts in diagnosis and treatment for CVD patients, and by systematically summarizing the relevant international guidelines and literature regarding the relationship between CVD and oral diseases and the diagnosis and treatment of dental patients with heart failure, hypertension and antithrombotic therapy. The consensus aims to provide, for the dental clinicians, the criteria on diagnosis and treatment of CVD in dental patients in China so as to reduce the risk and complications, and finally to improve the treatment levels of dental patients with CVD in China.

[Methylation of p16 gene and reduced expression of p16 protein in insulinoma associated with clinicopathological features]

Objective: To study the alterations of p16 gene and its expression in insulinoma and to correlate the findings with clinicopathological characteristics. Methods: Expression of p16 protein was detected in 72 insulinomas and 49 para-tumoral or normal pancreatic tissues by immunohistochemical staining. Genomic DNA was isolated from 32 tumor tissue and 17 paired pancreatic tissues and bisulfite-modified. Promoter methylation status of p16 gene was detected in 32 tumor tissue and 17 paired pancreatic tissues by methylation specific PCR. The findings were correlated with the clinicopathological features. Results: There were 30 males and 42 females in all 72 patients, aged (46.5±14.0) years. Loss or reduced expression of p16 protein was found in 42 of 72 insulinomas (58.3%) while loss or reduced expression of p16 was seen in only 34.7% (17/49) of para-tumoral or normal pancreatic tissues (χ²=6.52, P=0.011). Promoter methylation of p16 gene was found in 13 of 32 insulinomas (40.6%) and only 2 of 17 (11.8%) para-tumoral tissues (χ²=4.35, P=0.037). The expression of p16 protein in insulinoma was not associated with clinicopathological features such as gender, age, tumor size and tumor grade. Conclusions: Loss or reduced expression of p16 protein was found in insulinomas, and associated with p16 gene promoter methylation.

Integrating tumor mutational burden and transcriptome expression into prediction of immune checkpoint inhibitor response and prognosis of patients with colon cancer

Whether tumor mutational burden (TMB), which refers to the total number of somatic or acquired mutations per million bases in a particular region of the tumor genome, can serve as a predictive biomarker of immune checkpoint inhibitor (ICI) therapy for colon cancer remains unclear. Hereby, we retrospectively investigated the differentially expressed genes (DEGs) based on the level of TMB and tried to established a risk score model as a novel biomarker. The DNA mutation data were retrieved from the Masked Somatic Mutation in Genomic Data Commons data portal of the Cancer Genome Atlas, where the RNA sequencing data, clinical information, and survival outcomes of patients were downloaded. Patients with incomplete clinical information were excluded. The immune score and stromal score were calculated to investigate immune infiltration. The patients were grouped into TMB-high group and the TMB-low group based on the median value of TMB. An immune relevant gene set was obtained from the Immunology Database and Analysis Portal to identify immune-related DEGs. The Cox proportional hazard model and nomogram were applied to establish the risk model. In results: the TMB value was associated with age (p≤0.001), clinical stage (p≤0.001), N stage (p≤0.001), M stage (p=0.003), and immune score (p≤0.001). Twenty-nine immune-related DEGs were identified as enriched in immune response-related function or pathway and tumorigenesis signaling. Nine of 29 were determined to establish a riskScore model. The riskScore suggested a positive relationship with the TMB value (p=0.033), immune score (p≤0.001), and tumor immune dysfunction and exclusion (TIDE) (p=0.002) and presented an independent prognostic factor (p≤0.001, HR=1.04), which predicted the overall survival with good specificity. We concluded that the combination of TMB with transcriptome expression has a predictive and prognostic value for patients treated with ICIs.

[Meta analysis on acceptance rate of HIV pre-exposure prophylaxis among men who have sex with men in China]

Objective: To systematically evaluate the acceptance of pre-exposure prophylaxis (PrEP)among men who have sex with men (MSM) in China, so as to provide reference for the promotion of preventive drug use before human immunodeficiency virus exposure in China. Methods: By searching the databases of China national knowledge infrastructure, VIP database, Wanfan knowledge service platform, PubMed, Web of Science, Embase and The Cochrane Library with key words of "men who have sex with men" "pre-exposure prophylaxis" "PrEP" and "MSM". The literature on the willingness of Chinese MSM population to accept PrEP was systematically collected, and the data of the literature meeting the inclusion criteria were extracted for Meta analysis. Results: A total of 12 articles were selected in this study, including 6 articles in English and 6 in Chinese. The score of bias risk assessment of eligible articles was 14-18, which was more than 70% of the total score. The total number of samples was 11 269. The overall acceptance rate of PrEP was 0.77(95%CI:0.71-0.82). In subgroup analysis, the acceptance rates of different nationalities, marriage, household registration, age, education background, income, sexual orientation, sexual behavior and awareness of PrEP were statistically significant. Conclusion: In general, the acceptance rate of PrEP in MSM population is higher, but the awareness rate is low. There are differences in the acceptance rate among different groups.

[Comparison of early postoperative effects between anterior bladder and posterior bladder approaches in robotic assisted laparoscopic radical prostatectomy]

Objective: To examine the effect of robotic assisted laparoscopic radical prostatectomy with different approaches on early postoperative effects. Methods: Totally 44 patients (average age of 65.9 years, range: 46 to 81 years) underwent robotic assisted laparoscopic radical prostatectomy by a single operator at Department of Urology, Peking Union Medical Collage Hospital from March 2018 to March 2020 were retrospectively analyzed. The mean age was 65.9 years (range: 46 to 81 years), including 24 cases in the anterior bladder approach group (anterior approach group) and 20 cases in the posterior bladder approach group (posterior approach group). The preoperative clinical data, perioperative related data and postoperative urinary control recovery were compared between the two groups by t test, χ² test or Fisher exact test. Results: In terms of clinical data, there was no difference in age, prostate volume, preoperative prostate specific antigen and Gleason score(all P>0.05). There was no significant difference in operation time ((184±43) minutes vs. (193±42) minutes, t=-0.599, P=0.55), bleeding volume ((218±88) ml vs. (225±115) ml, t=-0.244, P=0.81), postoperative stage (T2/T3: 15/9 vs. 12/8, χ²=0.029, P=0.87) and positive rate of cutting edge (29.2% (7/24) vs. 30.0% (6/20), χ²=0.004, P=0.95). In terms of postoperative urinary control, patient rates who achieved urinary control immediately after extubation was significantly higher for the posterior approach group than the anterior approach group (30.0% (6/20) vs. 4.2% (1/24), P=0.04). There was no significant difference between two groups for those who achieved urinary control 3 months after operation (6 cases vs. 11 cases, P=0.06), 6 months after operation (20 cases vs. 19 cases, P=0.36) and those who achieved urinary control 12 months after operation (23 cases vs. 19 cases, P=1). Conclusion: For robotic assisted laparoscopic radical prostatectomy, the posterior approach does not prolong the operation time, does not increase the amount of bleeding, and improves the short-term postoperative urinary control.

Band-selective Holstein polaron in Luttinger liquid material A0.3MoO3 (A = K, Rb)

(Quasi-)one-dimensional systems exhibit various fascinating properties such as Luttinger liquid behavior, Peierls transition, novel topological phases, and the accommodation of unique quasiparticles (e.g., spinon, holon, and soliton, etc.). Here we study molybdenum blue bronze A_0.3MoO₃ (A = K, Rb), a canonical quasi-one-dimensional charge-density-wave material, using laser-based angle-resolved photoemission spectroscopy. Our experiment suggests that the normal phase of A_0.3MoO₃ is a prototypical Luttinger liquid, from which the charge-density-wave emerges with decreasing temperature. Prominently, we observe strong renormalizations of band dispersions, which are recognized as the spectral function of Holstein polaron derived from band-selective electron-phonon coupling in the system. We argue that the strong electron-phonon coupling plays an important role in electronic properties and the charge-density-wave transition in blue bronzes. Our results not only reconcile the long-standing heavy debates on the electronic properties of blue bronzes but also provide a rare platform to study interesting excitations in Luttinger liquid materials.

Direct Measurement of the Astrophysical ^{19}F(p,αγ)^{16}O Reaction in the Deepest Operational Underground Laboratory

Fluorine is one of the most interesting elements in nuclear astrophysics, where the ^{19}F(p,α)^{16}O reaction is of crucial importance for Galactic ^{19}F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential ^{19}F(p,αγ)^{16}O reaction channel. The γ-ray yields were measured over E_{c.m.}=72.4-344  keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-ray-induced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear ^{19}F(p,αγ)^{16}O reaction rate has been determined directly at the relevant astrophysical energies.

[Role of hepatic surgery in colorectal cancer multiple liver metastasis]

Colorectal cancer liver metastasis can be categorized as initially resectable and initially unresectable liver metastasis. Patients with initially resectable colorectal cancer liver metastases may benefit from hepatic surgery significantly,while those with initially unresectable metastases also have an opportunity to be treated radically by liver surgery after conversion therapy,so as to have a prolonged survival time. It is crucial to choose the right time and right way of surgical intervention. The timing depends on determination of tumor resectability,controlling of pre-operative systemic therapy and evaluation of liver function after systemic treatment. The selection of right way contains the election between synchronous operation and staged operation, resection margin and using of technologies such as laparoscope and associating liver partition and portal vein ligation for staged hepatectomy. This paper aims to explore the optimal timing for operation and the approaches of surgical method based on the research progress worldwide for prolonging the survival time of patients with colorectal cancer multiple liver metastases.

[Structuring process approach to laparoscopic anatomical liver central lobectomy for hepatocellular carcinoma]

Objective: To investigate the feasibility and oncological efficacy of structuring process approach to laparoscopic anatomical liver central lobectomy for hepatocellular carcinoma. Methods: The clinical data of 65 patients with hepatocellular carcinoma who underwent laparoscopic anatomical liver central lobectomy at the Department of Hepatobiliary Surgery, Sun Yat-sen Memorial Hospital from April 2017 to April 2021 was retrospectively analyzed. There were 39 males and 26 females,aged (M(Q_R)) 61.2 (29.5) years (range:25 to 80 years).The body mass index was (24.2±3.8) kg/m² (range:19.5 to 26.1 kg/m²) and the tumor diameter was (6.7±2.9)cm(range:3.4 to 10.5 cm).This structuring process approach was designed using a series of main vessels as the plane markers, along which liver transection was carried out. The perioperative indicators and early oncological efficacy were then analyzed. Results: All the procedures were successfully carried out laparoscopically. The operative time was (190.5±70.4) minutes (range:90 to 280 minutes). The blood loss was (370.6±120.8)ml(range:100 to 1 050 ml). No patient received blood transfusion or converted to laparotomy. Postoperative complications occurred in 8 cases(12.3%). Postoperative hospital stay was (7.5±2.5) days(range:5 to 18 days).There was no perioperative death and rehospitalization within 30 days. Pathological study showed all the operations to be R0 resections, the average surgical margin was (2.4±1.9)cm(range:0.5 to 3.1 cm).The tumor recurrence rate was 12.3% after 1 year follow-up. Conclusion: Structuring process approach to laparoscopic anatomical liver central lobectomy could be used to treat patients with hepatocellular carcinoma.

Protective effects of lycopene on mitochondrial oxidative injury and dysfunction in the liver of aflatoxin B1-exposed broilers

This study was conducted to investigate the effects of lycopene (LYC) on mitochondrial oxidative injury and dysfunction in the liver of aflatoxin B₁ (AFB₁)-exposed broilers. A total of 192 healthy 1-day-old male broilers were randomly divided into 3 groups with 8 replicates of 8 birds each. Birds in the 3 groups were fed basal diet (control), basal diet with 100 µg/kg AFB₁, and basal diet with 100 µg/kg AFB₁ and 200 mg/kg LYC, respectively. The experiment lasted 42 d. The results showed that AFB₁ decreased average daily body weight gain (ADG), average daily feed intake, and gain to feed ratio (G :F) compared to the control group, the LYC supplementation increased ADG and G/F compared to AFB₁ group (P < 0.05). Broilers in the AFB₁ group had lower mitochondrial glutathione (mGSH) concentration and glutathione peroxidase (GSH-Px), manganese superoxide dismutase (MnSOD), and thioredoxin reductase activities, and higher hydrogen peroxide (H₂O₂) and reactive oxygen species (ROS) concentrations than the control group (P < 0.05). The LYC increased mGSH concentration and GSH-Px and MnSOD activities, and decreased H₂O₂ and ROS concentrations compared to AFB₁ group (P < 0.05). Broilers fed the AFB₁ diet showed increased mitochondrial swelling and decreased adenosine triphosphate concentration than the control group, and LYC had opposite effects (P < 0.05). The AFB₁ decreased the activities of mitochondrial electron transfer chain (ETC) complexes I, II, III, and V, downregulated the mRNA expression levels of hepatic MnSOD, thioredoxin 2, thioredoxin reductase, peroxiredoxin-3, peroxisome proliferator-activated receptor γ coactivator 1α, nuclear respiratory factor 1, and mitochondrial transcription factor A compared with the control group (P < 0.05), and LYC increased activities of mitochondrial ETC complexes III and V, and upregulated mRNA expression levels of these genes in comparison to AFB₁ group (P < 0.05). In conclusion, the LYC protected broilers from AFB₁-induced liver mitochondrial oxidative injury and dysfunction by stimulating mitochondrial antioxidant capacity and maintaining mitochondrial biogenesis.

[Clinical application and research progress of balloon-occluded retrograde transvenous obliteration in the treatment of gastric varices with decompensated liver cirrhosis]

Gastric varices are one of the serious complications of liver cirrhotic portal hypertension. Balloon-occluded retrograde transvenous obliteration (BRTO), as an interventional treatment method, can effectively prevent and control gastroesophagel variceal bleeding. Simultaneously, it has an obvious effect in the treatment of hepatic encephalopathy and liver function improvement. This article reviews the clinical application and research progress of BRTO at home and abroad in recent years, with a view to provide reference for clinical treatment.

[Effect of simulated occlusal force on periodontal ligament stem cells of the deciduous teeth at different stages of root absorption]

Objective: To explore the related mechanisms of biological root resorption in decidual teeth by studying the biological effect of simulated occlusal force on the periodontal ligament stem cells (PDLSC) at different stages of root absorption. Methods: According to the tooth type and root absorption degree, healthy retained deciduous incisors and healthy first premolars that needed to be removed for orthodontic treatment were collected and divided into three groups with six teeth in each group: the deciduous unabsorbed group (UN group), the absorbed group (R group) and the permanent teeth group (P group). PDLSC was isolated from periodontal ligament and cultured. PDLSC of three groups were loaded with dynamic pressure of 0-45, 0-90, 0-135, 0-180, 0-225 and 0-270 kPa, respectively. The proliferation ability was detected by cell counting kit-8 (CCK-8) technique on day 1 to day 7, respectively. The apoptosis levels of PDLSC after loading with dynamic pressure of 0-45, 0-90, 0-135, 0-180 and 0-225 kPa were observed by the flow cytometry. The changes of microfilaments were observed by fibrous actin (F-actin) staining after the cytokeleton was subjected to dynamic pressure of 0-90 kPa. Results: PDLSC of three groups exhibited various proliferation abilities to dynamic pressure. The A values in the UN group and R group were significantly higher than those in the P group and the difference was statistically significant (P<0.05). However, there was no significant difference between the UN group and the R group (P>0.05). The A values of PDLSC in UN group and R group under dynamic pressures of 0-45, 0-90, 0-135 and 0-180 kPa had no statistical significance compared with the control group unloading dynamic pressure (P>0.05). However, under 0-225 and 0-270 kPa dynamic pressures, the A values at the day 3 to day 7 were statistically significant (P<0.05). The A values of PDLSC in P group under 0-45, 0-90, 0-135, 0-180 and 0-225 kPa dynamic pressures for 1 to 7 days were no statistically significant difference compared with the control group (P>0.05). The A value in P group under the 0-270 kPa was statistically significant only on day 3 (1.386±0.131) and day 5 to day 7 (1.728±0.226, 2.029±0.168 and 2.263±0.210, respectively)(P<0.05). The result of apoptosis showed that the A values of PDLSC in UN group, R group and P group were significantly increased under 0-90, 0-135, 0-180 kPa and above dynamic pressures, respectively (P<0.05) compared with the control group unloading dynamic pressure. Under 0-90 kPa dynamic pressure, F-actin fluorescence staining samples in three groups all showed green filaments which were arranged along the long axis of the cells in the R group and the P group, while some fibers in the UN group were closely arranged and promoted stress fiber assembly. Conclusions: The biological characteristics of PDLSC at different root absorption stages were changed when they were stimulated by mechanical stress, and PDLSC of the deciduous teeth at the root unabsorption stage were more sensitive to mechanical stress stimulation.

Distribution and risk assessment of hexachlorobutadiene, pentachloroanisole, and chlorobenzenes in sediment and wild fish from a region affected by industrial and agricultural activities in South China

Hexachlorobutadiene, pentachloroanisole, and chlorobenzenes are regulated to control their release into the environment. There is little information regarding the distribution and risks of these pollutants in Chinese rivers. Therefore, we selected a prosperous agricultural and industrial region in South China as our study area and investigated the contamination profiles and risks of these pollutants in sediment and fish tissue samples. The results showed that, when compared with their levels in sediment, these lipophilic pollutants tended to accumulate in fish tissues in the following order: liver > brain > muscle. Some trichlorobenzene was found to be the result of reductive dechlorination of higher chlorinated benzenes. Hexachlorobutadiene and hexachlorobenzene could pose medium risks at certain sampling sites, but in general, almost no risk was found to the ecosystem. When the estimated daily human intakes of analytes through fish consumption were calculated for different age groups, the results suggested the analytes were unlikely to be a serious health concern for human. Our results could be used to update the existing data on the occurrence of these pollutants in the aquatic environment and to provide information for further pollution control by the local government.

Discovery of emerging sulfur-containing PAHs in PM2.5: Contamination profiles and potential health risks

We reported the discovery and identification of emerging sulfur-containing polycyclic aromatic hydrocarbons, namely polycyclic aromatic sulfur heterocycles (PASHs), in PM_2.5 collected from two typical regions of China, Taiyuan and Guangzhou. Until now, there is no research on contamination status, sources and potential health risks of this unexpected group of organic contaminants in PM_2.5. High atmospheric concentrations (ngm^-3) and significant time-dependent variations were determined in PM_2.5 of Taiyuan from 2017 to 2018. Coal combustion/secondary formation and traffic emission/secondary formation were apportioned as possible pollution sources for the PM_2.5-bound PASHs in Taiyuan and Guangzhou, respectively. Dithiothreitol and cell viability assays were applied for evaluations of PASH-induced reactive oxygen species (ROS) production and cell toxicity based on the determined real exposure levels for adults. The results illustrated that PASHs in PM_2.5 possibly caused oxidative stress and inhibition of human bronchial epithelial cells in seriously polluted regions such as Taiyuan, suggesting that the pollutant-induced health concerns may need more investigations. This study provides new insights into PM_2.5 pollution, and is beneficial for the development of effective contamination control strategies and reduction of risks on public health.

Parameterized Analysis of Craniocerebral Injury Caused by Fist

Abstract

Objective Based on the theory of biomechanics, the finite element method was used to study the injury characteristics of different parts of brain hit by fist with different force and to predict the risk of craniocerebral injury, in order to provide reference for actual medical protection and forensic identification. Methods The finite element model of fist was constructed by using DICOM data modeling method and related software, and the effective mass and speed of fist were used to represent the kinetic energy of fist, and combined with human finite element model THUMS 4.02, the characteristics of craniocerebral injury caused by frontal and lateral blows were parametrically simulated. Results The probability of direct death from a blow to the head was low, but as fist power increased, so did the risk of craniocerebral injury. The characteristics of craniocerebral injury were also significantly different with the different fist hitting head locations. When the frontal area was attacked, the maximum equivalent stress of skull was 122.40 MPa, while that of brain tissue was 4.31 kPa. When the temporal area was attacked, the maximum equivalent stress of skull was 71.53 MPa, while that of brain tissue was 7.09 kPa. Conclusion The characteristics and risks of skull fracture and brain tissue injury are different when different parts of the brain are hit by fist. When the frontal area is hit, the risk of skull fracture is significantly higher than when the temporal area is hit. The risk of brain tissue injury is the opposite. The position with the highest probability of skull fracture is generally the place where the skull is directly impacted, and with the conduction of stress waves, it will spread to other parts of the skull, while the position with the highest risk of brain tissue injury is not the place where the brain is directly impacted.