[Cytotoxic effect of photodynamic liposome gel combined with trastuzumab on drugresistant breast cancer cells in vitro]

OBJECTIVE

To evaluate the cytotoxic effect of photodynamic therapy (PDT) combined with targeted therapy using cross-linked liposomes and gels (Ce6-PC-Tmab@A-Gel) loaded with photosensitizer Chlorin (Ce6) and the tumor-targeting drug Trastuzumab (Tmab) in drug-resistant HER2+ breast cancer cells.

OBJECTIVE

Ce6-PC-Tmab liposomes were prepared using the thin-film hydration method. The general properties, encapsulation efficiency and near-infrared responsivity of the nanoparticles were evaluated. Ce6-PC-Tmab@A-Gel with a shear response was prepared by freeze drying and stirring crosslinking, and its microstructure was observed with scanning electron microscopy (SEM) and the shear response evaluated using a rheometer. The inhibitory effect of Ce6-PC-Tmab@A-Gel in drug-resistant HER2⁺ breast cancer SK-BR-3 cells was assessed with cytotoxicity assay (MTT assay) combined with near-infrared light.

OBJECTIVE

The particle size of Ce6-PC-Tmab was 239.7±9.7 nm and the potential was -2.03±0.09 mV. The entrapment efficiency of Tmab by Ce6-PC-Tmab liposomes was (40.22± 0.73)%. The prepared Ce6-PC-Tmab@A-Gel had a good shear response with excellent drug release characteristics under nearinfrared light, and increased intensity and duration of near-infrared light exposure enhanced Tmab release from the gel. Ce6-PC-Tmab@A-Gel was stable at room temperature and in a simulated tumor microenvironment (pH 6.25). Cytotoxicity assay (MTT) showed that Ce6-PC-Tmab@A-Gel combined with near-infrared light resulted in a survival rate of (31.37±1.73)% in SKBR-3 cells, much lower than that in the control group and other treatment groups (P < 0.01); the combined treatment also had a high efficiency of ROS production, and ROS release reached (22.36 ± 0.11)% after 2 min of near-infrared light exposure.

OBJECTIVE

The prepared Ce6-PC-Tmab@A-Gel has good near-infrared light response release characteristics to ensure effective targeted therapy with Tmab. The injectable gel system potentially allows long-term local drug release in the tumor to improve the treatment efficacy against drug-resistant breast cancer.

Cell wall thickness and the molecular mechanism of heterogeneous vancomycin-intermediate Staphylococcus aureus

Methicillin‐resistant Staphylococcus aureus (MRSA) with reduced sensitivity to vancomycin (VAN) has caused many clinical cases of VAN treatment failure, but the molecular mechanism underlying the reduced sensitivity to VAN is still unclear. We isolated a heterogeneous VAN‐intermediate Staphylococcus aureus (hVISA), which was also a MRSA strain with reduced sensitivity to VAN. To investigate the molecular mechanism underlying the reduced sensitivity to VAN exhibited by the hVISA strain, we compared the hVISA strain with a VAN‐sensitive MRSA strain, known as the N315 strain. The images captured by transmission electron microscopy showed that the cell wall of the hVISA strain was significantly thicker than that of the N315 strain (36·72 ± 1·04 nm vs 28·15 ± 1·25 nm, P < 0·05), and the results of real‐time quantitative PCR analysis suggested that the expression levels of the cell wall thickness related genes (glmS, vraR/S, sgtB, murZ and PBP4) of the hVISA strain were significantly higher than those of the N315 strain (P < 0·05). In conclusion, this study indicated that the upregulation of the expression of the genes related to cell wall synthesis might be the molecular mechanism underlying the cell wall thickening of the hVISA strain and might be related to its resistance to VAN.

[Analysis of the self-conscious health status and influencing factors of greenhouse agricultural workers in Beijing suburb]

Objective: To explore the self-conscious health status and related influencing factors of greenhouse agricultural workers in Beijing suburb, so as to provide scientific basis for developing strategies to improve and promote the occupational health conditions of those workers. Methods: According to the production characteristics and scale of the main agricultural districts or counties in the suburb of Beijing, 182 agricultural production personnel were randomly selected to investigate the general situation, occupational situation and self-conscious health status during June 2018 to December 2019. The relevant factors which may affect the self-conscious health conditions were also analyzed by statistical methods. Results: The detection or reported rate of self-conscious health problems was 51.6% (94/182) , among which 29.1% (53/182) workers reported musculoskeletal disorder diseases and 21.4% (39/182) workers reported nervous system diseases. And the self-conscious health status of greenhouse agricultural workers were statistically different in household registration, gender, marital status, working years, mixing or spraying pesticides, smoking or eating in the greenhouse (P<0.05) . Moreover, gender, mixing or spraying pesticide, eating and smoking behavior in the workplace all had an impact on the risk of self-conscious health status of greenhouse agricultural workers (P< 0.05) . Specifically, male is the protective factor to reduce the occurrence of self-conscious symptoms of greenhouse agricultural workers (OR=0.447, 95%CI: 0.234~0.852) , while mixing or spraying pesticides and smoking or eating behaviors in the workplace are the risk factors (OR=1.055, 2.524; 95%CI: 0.503~2.210, 1.107~5.755) . Conclusion: Reducing pesticide use from the source thus minimize related exposure opportunities, strengthening occupational health education thus foster good hygienic habits and improve individual protection consciousness are of great significance for the health protection of greenhouse agricultural workers in Beijing suburb.

[Research progress on the expression and carcinogenic mechanisms of SETD2 in malignant tumors]

The human epigenetic gene of SET domain containing 2 (SETD2) is located at the cytogenetic band p21.31 of chromosome 3, which encodes the histone3 lysine36 trimethyltransferase SETD2, the major enzyme that catalyzes the trimethylation of lysine 36 on histone 3 (H3K36me3) of human. SETD2 involves in many pathologic and physiological processes such as transcriptional elongation, DNA damage repair, alternative splicing, epigenetic modifications of gene expression, viral immunology, embryonic development, and angiogenesis. A growing list of tumor types including renal cell carcinoma and mesothelioma develops with mutation or inactivation of SETD2. SETD2 loss-of-function promotes the occurrences and development of cancers by inhibiting process of transcription extension, damage repair, cell cycles, apoptosis and cell metabolism. The under expression and mutation of SETD2 is synthetically lethal with the inhibition of G2M checkpoint and PI3K-AKT pathway and SETD2 is considered as a potential epigenetic therapy targets. Furthermore, a loss of SETD2 indicates worse pathological features. There are huge prospects in the diagnosis and treatment of related cancers.

Apelin-13 promotes late endothelial progenitor cells differentiation by regulating Krüppel-like factor 4

OBJECTIVE

The endothelial progenitor cells (EPCs) differentiation plays an essential role in angiogenesis. The purpose of this study is to determine the potential mechanisms of apelin-13 in EPCs differentiation.

MATERIALS AND METHODS

The rats EPCs were isolated from the bone marrow and identified by DIL-acLDL and FITC-UEA-1 staining. EPCs were divided into four groups: the negative control group, the Krüppel-like factor 4 (KLF4) upregulation group, the KLF4 downregulation group, and the apelin-13 group. The EPCs differentiation was evaluated by cell migration, proliferation, and the expressions of surface markers CD31, CD34, CD133, and VEGFR-2 on mRNA and the protein levels, as well as immunofluorescence.

RESULTS

In the KLF4 up-regulation and apelin-13 groups, the EPCs number of G1, S, and G2/M phases decreased and suggested that KLF4 and apelin-13 were closely related to the EPCs proliferation. EPCs showed stronger migration ability with the elevation of KLF4 and apelin-13 while declined migration was detected in KLF4 siRNA transfected EPCs. The surface markers expressions on mRNA and the protein levels increased in the KLF4 upregulation group, and in the apelin-13 group there were similar results, as well as increased KLF4 expression.

CONCLUSIONS

The upregulation of apelin-13 significantly increased the expressions of EPCs surface markers, which were involved in early EPCs differentiated into late EPCs and influenced the cells migration and proliferation. Taking the elevation of KLF4 which performed similar effects of apelin-13, we believe that apelin-13 activates or synergizes with KLF4 to promote this process.

How the 'kitome' influences the characterization of bacterial communities in lepidopteran samples with low bacterial biomass

AIMS

We aimed to elucidate whether the DNA extraction kit and bacteria therein affect the characterization of bacterial communities associated with butterfly samples harbouring different bacterial abundancies.

METHODS AND RESULTS

We analysed bacteria associated with eggs of Pieris brassicae and with adults of this butterfly, which were either untreated or treated with antibiotics (ABs). Three DNA extraction kits were used. Regardless of the extraction kit used, PCR amplification of the bacterial 16S rRNA gene detected very low bacterial presence in eggs and AB-treated butterflies. In untreated butterflies, bacterial signal intensity varied according to the kit and primers used. Sequencing (MiSeq) of the bacterial communities in untreated and AB-treated butterflies revealed a low alpha diversity in untreated butterflies because of the dominance of few bacteria genera, which were detectable regardless of the kit. However, a significantly greater alpha diversity was found in AB-treated butterflies, evidencing a true bias of the results due to bacterial contaminants in the kit.

CONCLUSIONS

The so-called 'kitome' can impact the profiling of Lepidoptera-associated bacteria in samples with low bacterial biomass.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study highlights the necessity of method testing and analysis of negative controls when investigating Lepidoptera-associated bacterial communities.

Lrp6 Dynamic Expression in Tooth Development and Mutations in Oligodontia

Genes associated with the WNT pathway play an important role in the etiology of tooth agenesis. Low-density lipoprotein receptor-related protein 6 encoding gene (LRP6) is a recently defined gene that is associated with autosomal dominant inherited tooth agenesis. Here, we aimed to identify novel LRP6 mutations in patients with tooth agenesis and investigate the significance of Lrp6 during tooth development. Using whole-exome sequencing, we identified 4 novel LRP6 heterozygous mutations (c.2292G>A, c.195dup, c.1095dup, and c.1681C>T) in 4 of 77 oligodontia patients. Notably, a patient who carried a nonsense LRP6 mutation (c.2292G>A; p.W764*) presented a hypohidrotic ectodermal dysplasia phenotype. Preliminary functional studies, including bioinformatics analysis and TOP-/FOP-flash reporter assays, demonstrated that the activation of WNT/β-catenin signaling was compromised as a consequence of LRP6 mutations. RNAscope in situ hybridization revealed dynamic and special changes of Lrp6 expression during murine tooth development from E11.5 to E16.5. It was noteworthy that Lrp6 was specifically expressed in the epithelium at E11.5 to E13.5 but was expressed in both dental epithelium and dental papilla from E14.5 and persisted in both tissues at later stages. Our study broadens the mutation spectrum of human tooth agenesis and is the first to identify a LRP6 mutation in patients with hypohidrotic ectodermal dysplasia and reveal the dynamic expression pattern of Lrp6 during tooth development. Information from this study is conducive to understanding the functional significance of Lrp6 on the biological process of tooth development.

Observation of the efficacy of naloxone combined with acyclovir in the treatment of children viral encephalitis and its impacts on IL-1 and IL-6

OBJECTIVE

To analyze the clinical efficacy of naloxone combined with acyclovir in the treatment of children viral encephalitis and the impacts on inflammatory factors IL-1 and IL-6.

PATIENTS AND METHODS

96 children with viral encephalitis were retrospectively analyzed. They were treated from July 2013 to January 2014 in our hospital. They were divided into control group (45 cases treated with acyclovir) and observation group (51 cases treated with acyclovir combined with naloxone). Both groups were treated with comprehensive measures. Changes of the content of serum IL-1 and IL-6 in the two groups before and after treatment were monitored by enzyme-linked immunosorbent assay (ELISA). Signs, recovery time of clinical symptoms, total effective rate, occurrence of adverse reactions and adverse reactions after treatment of children in the two groups were compared.

RESULTS

Levels of serum IL-1 and IL-6 of children in the control group and the observation group decreased after treatment, and the decrease was greater in the observation group (p<0.05). Signs and recovery time of clinical symptoms of the observation group were significantly shorter than that of the control group (p<0.05). Indexes of serum in the observation group were significantly lower than those of the control group after treatment (p<0.05). The total effective rate of the observation group was significantly higher than that of the control group (p<0.05). The prevalence of adverse reactions and sequelae in the observation group were lower than those in the control group (p<0.05).

CONCLUSIONS

In the treatment of children, viral encephalitis has naloxone combined with ganciclovir had a more significant effect on the decrease of levels of serum IL-1 and IL-6; naloxone combined with acyclovir in the treatment of children viral encephalitis had better effects, lower adverse reactions and lower prevalence of sequelae compared with sole medication, which is worth clinical promotion.

Effects of oxaliplatin on inflammation and intestinal floras in rats with colorectal cancer

OBJECTIVE

The aim of this study was to investigate the effects of oxaliplatin on intestinal floras, inflammation level, apoptosis-related gene expressions and oxidative stress in rats with colorectal cancer.

MATERIALS AND METHODS

A total of 30 adult Sprague-Dawley (SD) rats were selected as research objects and were divided into control group, model group and oxaliplatin group. Rats in control group were raised normally, without any treatment. Rats in model group were subcutaneously injected with dimethylhydrazine (25 mg/kg) to establish the model of colorectal cancer. Meanwhile, rats in oxaliplatin group were injected with oxaliplatin (15 mg/kg) once every 2 weeks for 12 consecutive weeks. Peripheral blood, intestinal tumor tissues and feces were collected from rats. In addition, inflammatory indexes [tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), interleukin-4 (IL-4) and IL-1β], oxidative stress indexes [catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and total antioxidant capacity (T-AOC)], expressions of apoptosis-related genes [apoptotic protease activating factor-1 (Apaf1), Caspase-9, Survivin and B-cell lymphoma-2 (Bcl-2)] and intestinal floras were detected.

RESULTS

The abundance of microorganisms such as Sphaerobacterales, Adlercreutzia and Coriobacterium glomerans increased significantly in the intestines in control group (p<0.05). However, the abundance of Bifidobacterium, Rikenellaceae and Paraprevotella in the intestines was obviously higher in model group (p<0.05). Oxaliplatin group exhibited remarkably higher abundance of such microorganisms as Cyanobacteria, Alistipes and Metascardovia in rat intestines (p<0.05). The content of Alistipes was the highest in oxaliplatin group, followed by control group and model group, and the difference was statistically significant (p<0.05). The levels of serum TNF-α, CRP and IL-1β were remarkably higher in model group than those in control group (p<0.05). Oxaliplatin group exhibited notably lower levels of serum TNF-α, CRP and IL-1β (p<0.05) and higher IL-4 level than model group (p<0.05). The content of serum CAT, SOD, GSH and T-AOC was markedly elevated in model group compared with control group (p<0.05). However, it was significantly reduced in oxaliplatin group in comparison with model group (p<0.05). Compared with control group, model group had distinctly lower expressions of Apaf1, Caspase-9 and Survivin but an evidently higher expression level of Bcl-2 in tumor tissues (p<0.05). Moreover, the expressions of Apaf1, Caspase-9 and Survivin were clearly higher, while that of Bcl-2 was prominently lower in tumor tissues in oxaliplatin group than model group (p<0.05).

CONCLUSIONS

Oxaliplatin exerts significant effects on the inflammation, oxidative stress, apoptosis-related genes and intestinal floras in rats with CRC.

[Initial implantation experience and short-term follow-up results of implanting leadless intracardiac transcatheter pacing system]

Objective: To explore the utility and safety of leadless intracardiac transcatheter pacing system. Methods: The study was a prospective observational study. Patients underwent Micra transcatheter pacing system in Beijing Anzhen hospital from December 2019 to January 2020 were enrolled. The baseline characteristics, platelet count, hemoglobin, anticoagulation and/or antiplatelet therapy, mean procedural time, average fluoroscopy time, number of deployment and electrical parameters (threshold, R-wave amplitude, impedance) were recorded. Ultrasonography of bilateral femoral and iliac veins was performed in all patients. Patients were followed including access site complication, adverse event and device evaluation at implant, hospital discharge, 1 and 3 months post-implant. R-wave≥5 mV, impedance between 400 and 1 500 Ω and threshold increase≤1.5 V than implant is considered a stable parameter. Femoral access site complications included hematoma, hemorrhage, pseudoaneurysm, and arteriovenous fistula. Adverse events included dislodgement, cardiac effusion/perforation and infection. Left ventricular end diastolic diameter and ejection fraction before and at 1 month after implant were reported. Results: Five patients were enrolled and pacemaker implantation was successful in all 5 patients. Patients were all males and the average age was (78.4±8.4) years. 2 patients received aspirin and clopidogrel therapy, 1 patient suffered from anemia and thrombocytopenia occurred in 1 patient. No stenosis, occlusion and vascular malformation of bilateral femoral and iliac veins was observed. The mean implant time was (39.6±1.7) minutes. The average fluoroscopy time was (9.2±1.3) minutes and the number of deployment was (1.40±0.55). Electrical parameters(threshold, R-Wave amplitude and impedance) were as follows: (0.40±0.10) V/0.24 ms, (10.80±3.72) mV and (822.00±162.23) Ω at implant; (0.45±0.07) V/0.24 ms, (13.04±2.41) mV, and (748.0±91.5) Ω at discharge, (0.40±0.06) V/0.24 ms, (14.26±4.11) mV, and (700.0±91.7) Ω at 1 month post-implant and (0.39±0.05) V/0.24 ms, 14.40±3.97 mV, and (682.0±96.0) Ω at 3 months post-implant, respectively. Threshold increase was ≤1.5 V compared to that during implantation, electrical parameters were acceptable and stable. There was no difference in LVEDD [(44.00±5.24) mm vs. (44.00±5.34) mm,P=1.000] and EF [(62.00±3.39)% vs. (62.20±3.56)%, P=0.861] before and 1 month post-implant. No incidence of access site complications, cardiac effusion/perforation, dislodgment or infections occurred during the 3 months. Conclusions: The leadless transcatheter pacemaker implantation performed in our study archived a high implant success rate and favorable safety profile as well as associated with low and stable pacing thresholds. The long-term safety and benefit of leadless pacemaker need to be evaluated in future clinical studies.

[Analysis of influencing factors of textile workers' occupational stress]

Objective: To explore the occupational stress status and influencing factors of workers in a textile factory in Zhejiang Provice. Methods: In October 2018, 505 workers from a textile factory in Zhejiang Province were selected as research objects by convenient sampling method. A total of 505 questionnaires were distributed, 495 of which were effective and the effective recovery rate was 98.0%. Job Content Questionnaire (JCQ) and Effort Reward Imbalance Questionnaire (REI) were used to investigate textile workers' occupational stress and analyze its influencing factors. The differences of the composition ratio of different groups were tested by χ(2) test. The influencing factors such as age, gender and occupation on occupational stress were analyzed by multivariate logistic regression. Results: ERI analysis results showed that the high and low occupational stress accounted for 30.1% and 69.9%, respectively. The differences of occupational stress among workers of different job types and working ages were statistically significant (P<0.05) . The detection rates of high occupational stress of paper workers and spinners were 47.8% (11/23) and 44.8% (30/67) , respectively, higher than other jobs. The detection rate of high occupational stress for workers with more than 5 years of service was 46.4% (13/28) . The results of JCQ analysis showed that there was no statistical significance in the differences of daily working hours and length of service between different gender, education levels, types of work patterns, and occupational stress (P>0.05) . Job types had significant effects on the occupational stress defined by ERI (P<0.05) , the risk of occupational stress was 2.151 times than that of the coiler. Conclusion: There are significant differences in occupational stress risk among workers of different types of work in textile industry, so different measures should be taken to prevent and control occupational stress in different jobs.

[Association between perceived built environment attributes and adults' leisure-time physical activity in four cities of China]

Objective: To explore the associations between perceived built environment attributes and adults' leisure-time physical activity in four cities of China. Methods: Multistage cluster random sampling method was used to select adults aged 25 to 64 in Hangzhou, Suzhou, Chengdu, and Qingdao. Data were collected from June 2017 to July 2018. The perception of the urban built environment was assessed by the neighborhood environment walkability scale-abbreviated (NEWS-A), and the physical activity was assessed by the International Physical Activity Questionnaire. Generalized linear mixed models were used to explore the relationship between the perceived built environment and leisure-time physical activities. Results: A total of 3 789 participants were included in the analysis. After adjusting for potential confounders, better access to public services (OR=1.34, 95%CI: 1.02-1.75) and higher aesthetic quality (OR=1.37, 95%CI: 1.09-1.73) were positively associated with the possibility of engaging in leisure-time physical activity in the past week. Similarly, these two attributes were positively associated with leisure-time walking. Higher scores on the perception of street connectivity were positively associated with leisure-time walking [exp(β)=1.09, 95%CI: 1.00-1.19]. Higher residential density [exp(β)=1.000 4, 95%CI:1.000 0-1.000 8], better access to physical activity destinations[exp(β)=1.09, 95%CI: 1.00-1.19], and better aesthetics [exp(β)=1.11, 95%CI:1.00-1.22] were associated with higher leisure-time physical activity. Similarly, these three attributes were positively associated with the possibility of meeting the WHO recommendations. Conclusion: Changing some urban built environment attributes may increase leisure-time physical activity.

[Heritability of alcohol intake among adult twins, calculate by the structural equation model]

Objective: To explore the genetic and environmental effects on alcohol intake. Methods: Data on 9 231 pairs of adult twins of the same sex was collected from the Chinese National Twin Registry (CNTR), between 2015 and 2018 and used in this study. Structural equation model was used to estimate the effects of genetic and environmental factors on alcohol intake. Results: A total of 9 231 pairs of twins were included in the analysis, of which 6 085 pairs were monozygotic (MZ). The average age of MZ was (36.91±13.07) years old, and males accounted for 56.80%. The average age of dizygotic twins (DZ) was (35.22±12.48) years old, and males accounted for 55.91%. There were 350 pairs of alcohol-drinking twins were with high-risk, accounting for 1.90% and another 367 pairs (1.99%) were with medium-risk. Alcohol-drinkers with medium-risk were affected by additive genetics, common and unique environmental factors, seen among the twins. The overall heritability appeared as 24.3% (95%CI: 0 to 56.8%). Furthermore, 50.7% of the variation (95%CI: 20.4%-79.0%) could be explained by the common environmental factors and 24.9% (95%CI: 18.3%-36.5%) by unique environmental factors. High-risk related drinking behavior was affected by both common and unique environmental factors. The common environmental component appeared as 75.6% (95%CI: 69.6%-80.8%) and unique environmental component as 24.4% (95%CI: 19.2%-30.4%), respectively. Gender difference was seen in the heritability of those with medium or high-risk drinking behaviors. The heritability of men was 30.8% (95%CI: 9.8%-53.5%), while in women it was mainly affected by the environment. Conclusion: Both alcohol drinkers with medium and high-risk drinking behaviors were mainly affected by the environment factors and gender. With the increase of drinking volume, the effect of environment on drinking behaviors became more obvious.

[Association between snoring and hypertension among Zhejiang adults in a cross sectional study]

Objective: To explore the association between snoring and prevalent hypertension among adults in Zhejiang with a cross-sectional study. Methods: After excluding participants with self-reported, physician-diagnosed heart diseases, stroke and cancer at baseline study, 56 728 participants aged 30-79 in the China Kadoorie Biobank study from Tongxiang, Zhejiang were included for the final analysis. Three multivariable logistic regression models were used to estimate the ORs for the associations of snoring with prevalent hypertension. Results: The proportion of participants who snored frequently, snored sometimes, and never snored were 24.55%, 23.94%, and 51.51%, respectively. The corresponding figures of males were 32.40%, 26.55%, and 41.05%, respectively. The corresponding figures of females were 19.00%, 22.08%, and 58.92%, respectively (P<0.001). After adjusted socio-demographic factors, behavioral lifestyle, BMI, waist circumference, and sleep duration etc., in comparison with participants who never snored, the odds ratios (95%CI) of hypertension for those who snored frequently and snored sometimes were 1.17 (1.12-1.23) and 1.12 (1.07-1.18), respectively. The effects of snoring on hypertension were statistically significantly different between women and men, participants who were central obese and those who were not, and between premenopausal and post-menopausal women. Conclusion: Snoring was associated positively with hypertension among adults. The effect of snoring on prevalent hypertension were obvious, especially among people, being female, being central obese, and being premenopausal.

Discovery of selection-driven genetic differences of Duroc, Landrace, and Yorkshire pig breeds by EigenGWAS and Fst analyses

Pigs are one of the earliest domesticated animals and multiple breeds have been developed to meet the various demands of consumers. EigenGWAS is a novel strategy to identify candidate genes that underlying population genetic differences and to infer candidate regions under selection as well. In this study, EigenGWAS and F_st analyses were performed using the public re-sequencing data of three typical commercial pig breeds, Duroc, Landrace and Yorkshire. The intersection of genome-wide significant SNPs detected by EigenGWAS and top-ranked 1% SNPs of F_st results were treated as signals under selection. Using the data of all three breeds, 3062 signals under selection were detected and the nearby genomic regions within 300 kb upstream and downstream covered 6.54% of whole genome. Pairs of breeds were analysed along with the pathway analysis. The gene function enrichment results indicated that many candidate genes located in the genomic regions of the signals under selection were associated with biological processes related to growth, metabolism, reproduction, sensory perception, etc. Among the candidate genes, the FSHB, AHR, PTHLH, KDR and FST genes were reported to be associated with reproductive performance; the KIT, KITLG, MITF, MC1R and EDNRB genes were previously identified to affect coat colour; the RETREG1, TXNIP, BMP5, PPARD and RBP4 genes were reported to be associated with lipid metabolism and growth traits. The identified genetic differences across the three commercial breeds will advance understanding of the artificial selection history of pigs and the signals under selection will suggest potential uses in pig genomic breeding programmes.

[Heritability of coronary heart disease, based on the data from the Chinese adult twins]

Objective: To analyze the heritability of coronary heart disease (CHD) among the Chinese twin adults. Methods: A total of 20 477 same-sex twin pairs aged 25 years and older from the Chinese National Twin Registry were interviewed. Structure equation model was used to estimate the heritability of CHD. Results: After adjusting for age and gender, the overall heritability of CHD was 0.75(0.68-0.81). Stratified analyses showed that genetic factors play a more important role in CHD incidence in ≥40 years or female twins. While the development of CHD was mainly influenced by environmental factors in 25-39 years or male twins. Conclusion: CHD is influenced by both genetic and environmental factors and the heritability is high.