[Asymptomatic infection of COVID-19 and its challenge to epidemic prevention and control]

COVID-19 had caused the epidemic in Wuhan of China in December 2019. The asymptomatic infection of COVID-19 was found with the further research. This paper summarizes the discovery of the asymptomatic infection cases, analyzes their outcomes and transmission risks, and put forward the targeted suggestions for the prevention and control of asymptomatic infection of COVID-19 according to the existing problems in epidemic response.

Emerging salt marshes as a source of Trichoderma arenarium sp. nov. and other fungal bioeffectors for biosaline agriculture

AIMS

Sustainable agriculture requires effective and safe biofertilizers and biofungicides with low environmental impact. Natural ecosystems that closely resemble the conditions of biosaline agriculture may present a reservoir for fungal strains that can be used as novel bioeffectors.

METHODS AND RESULTS

We isolated a library of fungi from the rhizosphere of three natural halotolerant plants grown in the emerging tidal salt marshes on the south-east coast of China. DNA barcoding of 116 isolates based on the rRNA ITS1 and 2 and other markers (tef1 or rpb2) revealed 38 fungal species, including plant pathogenic (41%), saprotrophic (24%) and mycoparasitic (28%) taxa. The mycoparasitic fungi were mainly species from the hypocrealean genus Trichoderma, including at least four novel phylotypes. Two of them, representing the taxa Trichoderma arenarium sp. nov. (described here) and T. asperelloides, showed antagonistic activity against five phytopathogenic fungi, and significant growth promotion on tomato seedlings under the conditions of saline agriculture.

CONCLUSIONS

Trichoderma spp. of salt marshes play the role of natural biological control in young soil ecosystems with a putatively premature microbiome.

SIGNIFICANCE AND IMPACT OF THE STUDY

The saline soil microbiome is a rich source of halotolerant bioeffectors that can be used in biosaline agriculture.

Effects of capsaicin on laying performance, follicle development, and ovarian antioxidant capacity in aged laying ducks

The present study was conducted to evaluate the effects of dietary addition of capsaicin (CAP) on egg production performance, follicular development, and ovarian antioxidant capacity in laying ducks. Three hundred seventy eight 58-wk-old laying ducks were randomly divided into 3 treatments, each treatment consisted 6 replicates, with 12 individually caged laying ducks per replicate. Ducks fed a basal diet served as control, the other 2 groups of ducks were fed the same diet containing 150 mg/kg CAP but in the manner of feed restriction (pair-fed) or ad libitum fed. The experiment lasted for 8 wk. The results showed that the dietary supplementation with CAP under conditions of ad libitum feeding increased feed intake (P < 0.001) and tended (P < 0.1) to increase egg production and egg weight in laying ducks but had no effects on daily egg mass and feed conversion ratio. The relative weight of large yellow follicles from the 2 CAP-supplemented groups at 64 wk of age were significantly higher than that of the controls (P = 0.01). The relative weight of the small yellow follicles in the CAP free-fed group was significantly higher than that of the other 2 groups (P < 0.01). Capsaicin supplementation under ad libitum feding conditions tended to increase the number of dominant follicles in laying ducks (P = 0.06). The ovarian mRNA expression of genes related to calcium signaling (TRPV4, ATP2A2, ITPR1, and CaM) in the CAP ad libitum fed groups were significantly higher than those of the other 2 groups (P < 0.05). The ovarian mRNA expression of CDK1 in CAP free-fed ducks was significantly higher than that of the other 2 groups (P = 0.01). Capsaicin supplementation significantly increased the plasma glutathione peroxidase activity (P < 0.01) in comparison with the control group but reduced the malondialdehyde content in the ovaries of laying ducks (P < 0.01). The results of this study indicates that dietary supplementation of CAP increased feed intake and improved egg production performance probably by activating calcium signaling pathway and improving redox status.

[Study on spatial clustering characteristics of tuberculosis in China, 2013-2018]

Objective: To explore the tuberculosis (TB) clustering areas and changing tendency in China from 2013 to 2018, so as to provide evidence for improving the control and prevention programs on TB. Methods: Spatial distribution of TB in China from 2013 to 2018 was studied using data from TB information management system of Chinese disease prevention and control information system. The SaTScan 9.6 software was used to detect and analyze the TB clusters and relative risks. Likelihood ratio and P value under the scan windows were used as the main index to define the clusters. Results: The TB registration rate declined in China from 2013 to 2018. High-risk clusters were mainly located in western regions of Xinjiang, Tibet, Shaanxi, Sichuan, Chongqing, Yunnan, Guizhou, Guangxi provinces and central and eastern regions of Inner Mongolia, Hubei, Hunan, Jiangxi, Guangdong and Hainan provinces. The number of counties with TB clusters declined slowly, from 1 112 in 2013 to 806 in 2018. In comparison with areas other than the clusters, the RR of TB in the clusters remained at high levels in southern Xinjiang and western Tibet from 2013 to 2018 (RR>3.0). Conclusions: The number of the counties with TB clustering declined slowly from 2013 to 2018, and most of them were located in western and central China. Early detection and health education should be focused on TB patients to prevent the spread of TB. Management programs set for TB patients should be strengthened, especially in the western parts of the country where TB clusters and high relative risks existed.

Exercise stress global longitudinal strain echocardiography can detect subclinical cardiac dysfunction and assist in risk stratification in children with Kawasaki disease: a 3-year follow-up study

Background

Global longitudinal strain (GLS) echo has been regarded as a sensitive and reproducible indicator for detection of subclinical cardiac dysfunction in children with Kawasaki disease (KD), but whether it can assist in differentiating KD patients with different severity of coronary artery lesions (CALs) has been rarely reported. The purpose of this study was to determine the feasibility of GLS derived from rest and exercise stress echo in risk stratification in patients with KD.

Methods

43 children with KD and 50 healthy controls were enrolled. KDs was divided into 3 groups according to the severity of CALs based on Z score, which was measured at the 3-year follow-up, G1 = KD without CALs (Z&lt;2), G2 = KD with mild CALs (2≤Z&lt;5), G3 = KD with severe CALs (Z≥5). Both group underwent echo at the onset of KD diagnosis and at the 3 years' follow-up, including: diameter of LA and LV, thickness of LVPW and IVS, LVFS, LVEF, and rest GLS (GLSrest). Both group also accomplished the exercise stress echo at the 3 years' follow-up, who squatted quickly to reach target heart rate and stress GLS (GLSstress) was recorded. Patients in G3 underwent a CMR examination, including LGE, to detect myocardial ischemia or infarction.

Results

38 KDs and 50 HCs had normal exercise tolerance. There were 18, 8, and 12 patients in G1, G2, and G3, respectively. LA, LV, LVPW, IVS and LVEF, were not significantly different in the KDs at the onset and 3-year follow-up, and so did that between KDs and HCs (all p&gt;0.05). Both GLSrest and GLSstress in the KDs were significantly decreased compared with HCs (GLSrest: −17.2±9.1% vs. −22.3±0.7%, p&lt;0.01; GLSstress: −20.7±3.5% vs. −27.7±0.7%, p&lt;0.01, seen in Fig.1A, B). However, there were no significant difference in GLSrest among 3 subgroups of KDs (G1: −18.0±10.0%; G2: −19.7±1.2%; G3: 14.4±10.4%; all p&gt;0.05, seen in Fig.1C). GLSstress in the G3 decreased significantly compared with that in G1 and G2 (G3 vs. G1: −16.8±2.6% vs. −22.8±1.9%, p&lt;0.01; G3 vs. G2: −16.8±2.6% vs. −22.1±2.5%, p&lt;0.01, seen in Fig. 1D). GLSrest had no correlation with Z score (r=0.08, p=0.62), but GLSstress correlated well with Z score (r=0.70, p&lt;0.01). 8 of 12 (67%) patients in the G3 underwent CMR and 6 of 8 (75%) were found endomyocardial enhancement on LGE, which indicated myocardial infarction corresponding to the territory of abnormal coronary arteries (seen in Fig. 2).

Conclusions

GLS derived from rest and exercise stress speckle-tracking echo can detect subclinical cardiac dysfunction in KD patients with normal LV systolic function by conventional measurements, but rest GLS could not assist in differentiating KD patients with different severity of CALs. Exercise stress GLS, which correlated well with Z score, has the potential in risk stratification in children with KD, and thus may provide prognostic value in multidisciplinary treatment strategy.

Statistics and echo, CMR imaging

Funding Acknowledgement

Type of funding source: None

Morphological and microstructural brain changes in thyroid-associated ophthalmopathy: a combined voxel-based morphometry and diffusion tensor imaging study

PURPOSE

To explore the morphological and microstructural changes of grey and white matter in the patients of thyroid-associated ophthalmopathy (TAO).

METHODS

Twenty-five TAO patients and 25 well-matched healthy controls were recruited. Structural T1- and diffusion-weighted magnetic resonance imaging data were analyzed using voxel-based morphometry and voxel-based analysis of diffusion tensor imaging.

RESULTS

Compared with healthy controls, TAO group showed significantly decreased grey matter volume in the brain region of the right middle frontal gyrus. Meanwhile, TAO group showed significantly decreased fractional anisotropy (FA), but increased mean, axial and radial diffusivities in the brain regions of the right superior occipital gyrus, middle occipital gyrus and cuneus in TAO group. In addition, the FA value in significant brain regions showed a positive correlation with visual acuity (r = 0.456, P = 0.025) and a negative correlation with disease duration (r =  - 0.609, P = 0.003).

CONCLUSION

Significant morphological and microstructural abnormalities in areas corresponding to known functional deficits of vision and cognition could be found in TAO patients. These results extended our understanding of neural relationships with TAO.

Traumatic fractures in China from 2012 to 2014: a National Survey of 512,187 individuals

The China National Fracture Study has been conducted to provide a national dataset of traumatic fractures across China. A national representative sample of 512,187 individuals was selected. The population-weighted incidence rates, distribution, injury mechanisms, and risk factors for traumatic fractures were identified for various groups of individuals.

INTRODUCTION

The China National Fracture Study (CNFS) has been conducted to provide a comprehensive and up-to-date national dataset of traumatic fractures across China. This study aims to report the national incidences and distributions of traumatic fractures that occurred in 2012, 2013, and 2014 and to analyze the risk factors.

METHODS

A national representative sample of individuals was selected from 24 rural counties and 24 urban cities of 8 provinces using stratified random sampling and the probability proportional to size (PPS) methodology. Participants were interviewed to identify whether they sustained traumatic fractures of the trunk and/or four extremities that had occurred in 2012, 2013, and 2014. The main risk factors associated with traumatic fractures were analyzed by multiple logistic regression models.

RESULTS

A total of 512,187 individuals, including 259,649 males and 252,538 females, participated in the CNFS. The population-weighted incidence rates of traumatic fractures in China were calculated to be 2.5 (95% CI, 2.2-2.8) per 1000 population in 2012, 2.8 (95% CI, 2.5-3.3) in 2013, and 3.2% (95% CI, 2.8-3.6) in 2014. The population-weighted incidence rates of fragility fractures among participants aged 65 years and older were calculated to be 27.4 (95% CI, 21.4-33.4) per 1000 population in 2012, 36.0 (95% CI, 28.6-43.5) in 2013, and 42.4 (95% CI, 34.9-49.9) in 2014. The most common cause of fracture was low-energy injuries, followed by traffic accidents. For all age groups, sleeping less than 7 h was a risk factor for traumatic fractures. Alcohol consumption and previous fracture history were identified as risk factors for adults aged 15 years and over. Cigarette smoking was found to be a risk factor for males aged 15-64 years old. For individuals aged 15-64 years old, underweight incurred a risk effect for males and overweight for females. Alcohol consumption, sleeping less than 7 h per day, living in the central and eastern regions, a body mass index less of than 18.5, and having a previous fracture history were identified as strong risk factors for fragility fractures.

CONCLUSION

The national incidence, distribution, and injury mechanisms for traumatic fractures were revealed in the CNFS. Risk factors were identified for various groups of individuals.

Quantitative T1ρ MRI of the Head and Neck Discriminates Carcinoma and Benign Hyperplasia in the Nasopharynx

BACKGROUND AND PURPOSE

T1ρ imaging is a new quantitative MR imaging pulse sequence with the potential to discriminate between malignant and benign tissue. In this study, we evaluated the capability of T1ρ imaging to characterize tissue by applying T1ρ imaging to malignant and benign tissue in the nasopharynx and to normal tissue in the head and neck.

MATERIALS AND METHODS

Participants with undifferentiated nasopharyngeal carcinoma and benign hyperplasia of the nasopharynx prospectively underwent T1ρ imaging. T1ρ measurements obtained from the histogram analysis for nasopharyngeal carcinoma in 43 participants were compared with those for benign hyperplasia and for normal tissue (brain, muscle, and parotid glands) in 41 participants using the Mann-Whitney U test. The area under the curve of significant T1ρ measurements was calculated and compared using receiver operating characteristic analysis and the Delong test, respectively. A P < . 05 indicated statistical significance.

RESULTS

There were significant differences in T1ρ measurements between nasopharyngeal carcinoma and benign hyperplasia and between nasopharyngeal carcinoma and normal tissue (all, P < . 05). Compared with benign hyperplasia, nasopharyngeal carcinoma showed a lower T1ρ mean (62.14 versus 65.45 × ms), SD (12.60 versus 17.73 × ms), and skewness (0.61 versus 0.76) (all P < .05), but no difference in kurtosis (P = . 18). The T1ρ SD showed the highest area under the curve of 0.95 compared with the T1ρ mean (area under the curve  = 0.72) and T1ρ skewness (area under the curve  = 0.72) for discriminating nasopharyngeal carcinoma and benign hyperplasia (all, P < .05).

CONCLUSIONS

Quantitative T1ρ imaging has the potential to discriminate malignant from benign and normal tissue in the head and neck.

The effect of Clostridium tyrobutyricum Spo0A overexpression in the intestine of mice

Clostridium tyrobutyricum shows probiotic properties and can affect the composition of gut microbiota and regulate the intestinal immune system. Compared with other probiotics, this spore-producing bacterium shows unparalleled advantages in commercial production. In addition to being resistant to extreme living environments for extended periods, its endophytic spores are implicated in inhibiting cancer cell growth. We speculated that C. tyrobutyricum spores can also promote gut health, which mean it can maintain intestinal homeostasis. To date, the beneficial effects of C. tyrobutyricum spores on gut health have not been reported. In this study, a Spo0A-overexpressing C. tyrobutyricum strain was developed to increase spore production, and its probiotic effects on the gut were assessed. Compared with the wild-type, the engineered strain showed significantly increased sporulation rates. Mice administered with the engineered strain exhibited enhanced intestinal villi and the villus height/crypt depth ratio, weight gain and improved Firmicutes/Bacteroidetes ratio to facilitate intestinal homeostasis. This study demonstrated for the first time that enhanced spore production in C. tyrobutyricum can improve intestinal homeostasis, which is advantageous for its commercial application in food and pharmaceutical industry.

T2 mapping histogram at extraocular muscles for predicting the response to glucocorticoid therapy in patients with thyroid-associated ophthalmopathy

AIM

To evaluate the performance of T2 mapping histograms at the extraocular muscles (EOMs) in predicting the response to glucocorticoid therapy in the patients with active and moderate-severe thyroid-associated ophthalmopathy (TAO).

MATERIALS AND METHODS

Thirty active and moderate-severe TAO patients (responsive group, n=20; unresponsive group, n=10) were enrolled, and evaluated using T2 mapping before treatment. Histogram parameters (mean, median, max, min, 10th, 90th percentiles, skewness, and kurtosis) of T2 relaxation time (T2RT) at the EOMs for each orbit, and clinical variables (age, sex, disease duration, anti-thyroid treatment, smoking habit, pre-treatment thyroid function, thyrotrophin receptor antibody, diplopia presence, activity and severity scores) were collected and compared between groups. Logistic regression and receiver operating characteristic (ROC) curve analyses were used to assess the predictive value of identified independent variables for treatment response.

RESULTS

The responsive group showed significantly shorter disease duration (p=0.003), while higher T2RT_min than unresponsive group (p<0.001). Multivariate analysis showed that T2RT_min and disease duration were independent predictors for responsive TAOs. ROC curve analyses indicated that setting a cut-off value of ≥54.3 for T2RT_min demonstrated the optimal predicting specificity for responsive TAOs (100%), while a combination of T2RT_min ≥54.3 and disease duration ≤4.5 showed optimal predicting efficiency and sensitivity (area under the curve, 0.820; sensitivity, 65%).

CONCLUSIONS

Histogram analysis can help to exhibit the heterogeneity of T2RT at the EOMs. T2RT_min, together with disease duration may be the promising marker for predicting response to glucocorticoid therapy in the patients with active and moderate-severe TAO.

[The value of ultrasonic elastography in the differential diagnosis of choroidal melanoma and choroidal hemangioma]

Objective: To explore the role of the scoring and strain ratio methods of ultrasonic elastography in the differential diagnosis of choroidal melanoma and choroidal hemangioma. Methods: A cross-sectional study. Twenty-five patients (25 eyes) with choroidal melanoma treated in the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University from July to October 2016 were included in this study. There were 13 males and 12 females, with an average age of (48±12) years old. Twenty-five patients (25 eyes) with choroidal hemangioma treated in the same period were selected for differential diagnosis, including 12 males and 13 females, with an average age of (37±13) years. The lesions were examined by ultrasound elastography and scored, and the strain ratio of the tumor to the orbital tissue was measured. Two independent sample t test was used to compare the difference in the elasticity score and strain ratio between choroidal melanoma and choroidal hemangioma. The sensitivity, specificity and area under the receiver operating characteristic (ROC) curve were calculated to analyze the value of the two methods in the differential diagnosis of choroidal melanoma and choroidal hemangioma. Results: The elastography score of choroidal melanoma was (3.48±0.77) points, including 2 points in 3 cases, 3 points in 8 cases, 4 points in 13 cases, and 5 points in 1 case. The elastography score of hemangioma was (2.28±0.46) points, including 2 points in 18 cases and 3 points in 7 cases. The difference in the elasticity score between patients with the two kinds of tumors was statistically significant (t=6.694, P<0.01). The strain ratio was 42.97±15.83 and 12.21±9.24 in the patients with choroidal melanoma and choroidal hemangioma, respectively, and the difference was statistically significant (t=8.392, P<0.01). Using 3 points as the diagnostic critical point of the elastography score, the sensitivity was 88.0%, the specificity was 72.0%, and the area under the ROC curve was 0.80 (95% cofidence interval: 0.663 to 0.900, P<0.01). Using 21.67 as the diagnostic critical point of the strain ratio, the sensitivity was 92.0%, the specificity was 92.0%, and the area under the ROC curve was 0.92 (95% cofidence interval: 0.808 to 0.978, P<0.01). Conclusions: Ultrasound elastography plays a role in the differential diagnosis of choroidal melanoma and choroidal hemangioma. The differential diagnostic value of the strain ratio method is higher than the scoring method. (Chin J Ophthalmol, 2020, 56: 676-680).

A preliminary study: proteomic analysis of exosomes derived from thyroid-stimulating hormone-stimulated HepG2 cells

BACKGROUND

Thyroid-stimulating hormone (TSH) plays an important role in the regulation of lipid metabolism. However, little is known about the role that exosomes play in the process of TSH-induced lipotoxicity in non-alcoholic fatty liver disease (NAFLD). As a preliminary step, the present study set out to investigate alterations in protein expression in exosomes derived from TSH-stimulated HepG2 cells.

METHODS

HepG2 cells were treated with TSH, exosomes were collected, and proteins were identified by mass spectrometry (MS). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis were performed to analyze the identified proteins.

RESULTS

TSH treatment significantly increased exosomal production and changed the exosomal proteomic profile in HepG2 cells. Among the 1728 proteins, 140 identified proteins were upregulated and seven proteins were downregulated. GO analysis and KEGG analysis revealed that these proteins were involved in multiple processes including metabolism, apoptosis, and inflammation.

CONCLUSION

Our preliminary study demonstrated that exosomes derived from TSH-stimulated hepatocytes were increased and showed a specific altered spectrum of proteins, many of which were involved in metabolism, signal transduction, apoptosis, and inflammation. This study offers new insights into the pathogenesis of TSH-induced lipotoxicity in NAFLD.

[The role of large-scale testing platform in the prevention and control of the COVID-19 pandemic: an empirical study based on a novel numerical model]

Objective: China adopted an unprecedented province-scale quarantine since January 23rd 2020, after the novel coronavirus (COVID-19) broke out in Wuhan in December 2019. Responding to the challenge of limited testing capacity, large-scale (>20 000 tests per day) standardized and fully-automated laboratory (Huo-Yan) was built as an ad-hoc measure. There is so far no empirical data or mathematical model to reveal the impact of the testing capacity improvement since quarantine. Methods: Based on the suspected case data released by the Health Commission of Hubei Province and the daily testing data of Huo-Yan Laboratory, the impact of detection capabilities on the realization of "clearing" and "clearing the day" of supected cases was simulated by establishing a novel non-linear and competitive compartments differential model. Results: Without the establishment of Huo-Yan, the suspected cases would increase by 47% to 33 700, the corresponding cost of quarantine would be doubled, the turning point of the increment of suspected cases and the achievement of "daily settlement" (all newly discovered suspected cases are diagnosed according to the nucleic acid testing result) would be delayed for a whole week and 11 days. If the Huo-Yan Laboratory could ran at its full capacity, the number of suspected cases could start to decrease at least a week earlier, the peak of suspected cases would be reduced by at least 44%, and the quarantine cost could be reduced by more than 72%. Ideally, if a daily testing capacity of 10 500 tests was achieved immediately after the Hubei lockdown, "daily settlement" for all suspected cases could be achieved. Conclusions: Large-scale, standardized clinical testing platform, with nucleic acid testing, high-throughput sequencing, and immunoprotein assessment capabilities, need to be implemented simultaneously in order to maximize the effect of quarantine and minimize the duration and cost of the quarantine. Such infrastructure, for both common times and emergencies, is of great significance for the early prevention and control of infectious diseases.

[Analysis of clinicopathological features of clear cell tumor of the lung]

Objective: To analyze the clinicopathological features of clear cell tumor of the lung (CCTL). Methods: A total of 9 cases were collected from August 2008 to August 2019 in the Department of Pathology of the First Medical Center of PLA General Hospital and Hainan Hospital of PLA General Hospital. Their clinical data, pathological characteristics, immunohistochemical staining and special staining results were summarized and analyzed. Results: There were 3 males and 6 females, aged from 28 to 70 years (average 52.2 years). All tumors were located in the peripheral part of the lung, and were solitary in 8 cases, and multiple (24 nodules) in 1 case. The lesion was round or oval, with clear boundary. The diameter of the nodule was 0.5-5.5 cm. Histologically, the tumor cells were oval, short fusiform or polygonal, with obvious nucleoli. The tumor cells were mostly distributed in sheet around thin-walled vessels, and there was hyaline degeneration around the blood vessels. Neither necrosis nor mitosis could be seen. Immunohistochemical staining showed tumor cells were diffusely positive for Vimentin, and CD34, Melan-A, specific monoclonal antibody against melanoma (HMB45) and S-100 were positive with different degrees. Broad spectrum cytokeratin (CK), epithelial membrane antigen (EMA), smooth muscle actin (SMA), desmin, CD10, paired box gene 8 (PAX-8) or myomodulatory protein (Myo-D1) were all negative. The positive index of the proliferating cell nuclear antigen (Ki-67) was low. Schiff dyeing with periodate (PAS) staining was positive, PAS staining of glycogen digested by amylase (d-PAS) staining was negative. All the tumors in the nine cases were resected and patients were followed up for 5-137 months. Except 1 case was lost for follow-up, the other 8 cases survived without recurrence or metastasis of the disease. Conclusions: CCTL is a rare benign tumor, most of which are single, few of which can be multiple; histopathological characteristics and immunohistochemical staining are helpful for diagnosis and differentiated diagnosis. After complete resection, the prognosis was good. However, when histological features indicating malignancy, intense follow-up should be considered.

Estimation of dietary manganese requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, tibial characteristics, and serum biochemical and antioxidant indices

This study was aimed at estimating the dietary manganese (Mn) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 17 wk were randomly allocated to 6 treatments. The birds were fed with a basal diet (Mn, 17.5 mg/kg) or diets supplemented with 20, 40, 80, 120, or 160 mg/kg of Mn (as MnSO₄·H₂O) for 18 wk. Each treatment had 6 replicates of 14 ducks each. As a result of this study, dietary Mn supplementation did not affect the productive performance of laying duck breeders in the early laying period (17–18 wk), but affected egg production, egg mass, and feed conversion ratio (FCR) from 19 to 34 wk (P < 0.05), and there was a linear and quadratic effect of supplement level (P < 0.05). The proportion of preovulatory ovarian follicles increased (P < 0.01) linearly and quadratically, and atretic follicles (weight and percentage) decreased (P < 0.05) quadratically with dietary Mn supplementation. The density and breaking strength of tibias increased (quadratic; P < 0.05), the calcium content of tibias decreased (linear, quadratic; P < 0.01), and Mn content increased (linear, quadratic; P < 0.001) with increase in Mn. The addition of Mn had a quadratic effect on serum contents of estradiol, prolactin, progesterone, luteinizing hormone, and follicle-stimulating hormone (P < 0.001). Dietary Mn supplementation decreased serum contents of total protein (linear, P < 0.05), glucose (quadratic, P < 0.05), total bilirubin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and calcium (linear, quadratic; P < 0.05). The serum total antioxidant capacity and total and Mn-containing superoxide dismutase activities increased (linear, quadratic; P < 0.001), and malondialdehyde content decreased (linear, quadratic; P < 0.001) in response to Mn supplemental levels. The dietary Mn requirements, in milligram per kilogram for a basal diet containing 17.5 mg/kg of Mn, for Longyan duck breeders from 19 to 34 wk of age were estimated to be 84.2 for optimizing egg production, 85.8 for egg mass, and 95.0 for FCR. Overall, dietary Mn supplementation, up to 160 mg/kg of feed, affected productive performance, tibial characteristics, and serum biochemical and antioxidant status of layer duck breeders. Supplementing this basal diet (17.5 mg/kg of Mn) with 85 to 95 mg/kg of additional Mn was adequate for laying duck breeders during the laying period.

Genome-wide Analyses Identify a Novel Risk Locus for Nonsyndromic Cleft Palate

The 3 major subphenotypes observed in patients with nonsyndromic orofacial clefts (NSOFCs) are nonsyndromic cleft lip only (NSCLO), nonsyndromic cleft lip with palate (NSCLP), and nonsyndromic cleft palate only (NSCPO). However, the genetic architecture underlying NSCPO is largely unknown. Here we performed a 2-stage genome-wide association study (GWAS) on NSCPO and replication analyses of selected variants in other NSOFCs from the Chinese Han population. We identified a novel locus (15q24.3) and a known locus (1q32.2) where variants in or near the gene reached genome-wide significance (2.80 × 10^-13 < P < 1.72 × 10^-08) in a test for association with NSCPO in a case-control design. Although a variant from 15q24.3 was found to be significantly associated with both NSCPO and NSCLP, the direction of estimated effects on risk were opposite. Our functional annotation of the risk alleles within 15q24.3 coupled with previously established roles of the candidate genes within identified risk loci in periderm development, embryonic patterning, and/or regulation of cellular processes supports their involvement in palate development and the pathogenesis of cleft palate. Our study advances the understanding of the genetic basis of NSOFCs and provides novel insights into the pathogenesis of NSCPO.

Arsenite induces dysfunction of regulatory T cells through acetylation control of the Foxp3 promoter

Arsenic is known to cause damage to the body's immune system by inducing epigenetic changes. However, the molecular mechanism of this damage remains elusive. Here, we report that arsenic disrupts the morphology of lymphocytes, decreases cell viability, and results in abnormal proportions of T lymphocyte subsets. Moreover, our results revealed that arsenic can reduce global acetylation of histone H4 at K16 (H4K16 ac) in lymphocytes via decreasing the level of males absent on the first but upregulates mRNA and protein levels of the forkhead/winged-helix box P3 (Foxp3) gene by increasing the acetylation of histone H4 at K16 (H4K16) at the promoter of Foxp3. Finally, arsenic-induced dysfunction of regulatory T cells (Tregs) could be ameliorated by trichostatin A. Our research indicates that arsenic-induced immunosuppressive effect in human lymphocytes may be related to the acetylation of H4K16 at the promoter of Foxp3 and that histone deacetylase inhibitors may play a role in the prevention and treatment of immune injury caused by arsenic.

Random lasing from optical fibers with phase separated glass cores

A novel random laser, integrating a passive optical fiber with a phase separated aluminosilicate core-silica cladding as the feedback medium, is proposed and presented. The core exhibits greatly enhanced Rayleigh scattering, therefore requiring a significantly reduced length of scattering fiber (4 m) for lasing. With a Yb-doped fiber as the gain medium, the fiber laser operates at 1050 nm with low threshold power and possesses an output that can be amplified through conventional means. Furthermore, the laser was found to have a high degree of spatial coherence, spectral broadening with increasing input power, and temporal spectral variation. The facile setup and results herein pave the way for further study and applications based on low threshold random fiber lasers.

Development of a combined immunochromatographic lateral flow assay for accurate and rapid Escherichia coli O157:H7 detection

Escherichia coli O157:H7 is an important pathogenic Bacterium that threatens human health. A convenient, sensitive and specific method for the E. coli O157:H7 detection is necessary. We developed two pairs of monoclonal antibodies through traditional hybridoma technology, one specifically against E. coli O157 antigen and the other specifically against E. coli H7 antigen. Using these two pairs of antibodies, we developed two rapid test kits to specifically detect E. coli O157 antigen and E. coli H7 antigen, respectively. The detection sensitivity for O157 positive E. coli is 1 × 10³ CFU per ml and for H7 positive E. coli is 1 × 10⁴ CFU per ml. Combining these two pairs of antibodies together, we developed a combo test strip that can specifically detect O157: H7, with a detection sensitivity of 1 × 10⁴ CFU per ml, when two detection lines are visible to the naked eye. This is currently the only rapid detection reagent that specifically detects O157: H7 by simultaneously detecting O157 antigen and H7 antigens of E. coli. Our product has advantages of simplicity and precision, and can be a very useful on-site inspection tool for accurate and rapid detection of E. coli O157:H7 infection.

Mechanism of LncRNA FOXC2-AC1 promoting lung cancer metastasis by regulating miR-107

OBJECTIVE

Previous studies have shown that long non-coding RNA (lncRNA) FOXC2-AC1 is one of cancer-promoting genes. However, the role of FOXC2-AC1 in lung cancer (LCa) has not been reported. This study aimed to investigate the expression characteristics of FOXC2-AC1 in LCa, and to further explore the mechanism by which it accelerates the metastasis of LCa.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect the level of FOXC2-AC1 in 62 pairs of LCa tissues and adjacent normal tissues, and the relationship between FOXC2-AC1 and LCa pathological parameters as well as the prognosis of patients were analyzed. Meanwhile, FOXC2-AC1 level was further verified in LCa cells by qRT-PCR. In addition, FOXC2-AC1 knockdown and overexpression models were constructed using lentivirus in LCa cell lines including H1299 and SPCA1, and the effect of FOXC2-AC1 on the biological function of LCa cells was analyzed by cell counting kit-8 (CCK-8) test along with transwell invasion and migration assay. Finally, the potential mechanism was explored using Western blotting assay.

RESULTS

In this study, qRT-PCR results indicated that the expression level of FOXC2-AC1 in LCa was considerably higher than that in normal tissues, with statistically significant differences. Compared with patients with low expression of FOXC2-AC1, patients with high expression of FOXC2-AC1 had higher incidence of distant metastasis and lower overall survival rate. Compared with the control group, the cell proliferation, invasion and metastasis capacities of FOXC2-AC1 overexpressing group were considerably enhanced, while opposite results were observed in the FOXC2-AC1 silencing group. In addition, miR-107 expression was found significantly reduced no matter in LCa cell lines or in tissues and showed a negative correlation with FOXC2-AC1. Subsequently, luciferase reporter gene assay demonstrated that overexpression of miR-107 significantly attenuated the luciferase activity of the wild-type FOXC2-AC1 vector without reducing the activity of the mutant vector or empty vector, further proving that FOXC2-AC1 could be targeted by miR-107 through this binding site. In addition, rescue experiment also found that FOXC2-AC1 and miR-107 have mutual regulation, which jointly affected the malignant progression of LCa.

CONCLUSIONS

These studies indicate that LncRNA FOXC2-AC1 is notably upregulated in LCa and is significantly correlated with LCa distant metastasis as well as poor prognosis. Therefore, it is suggested that lncRNA FOXC2-AC1 may promote malignant progression of LCa through the mutual regulation of miR-107.

Which animals are at risk? Predicting species susceptibility to Covid-19

In only a few months, the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, leaving physicians, scientists, and public health officials racing to understand, treat, and contain this zoonotic disease. SARS-CoV-2 has made the leap from animals to humans, but little is known about variations in species susceptibility that could identify potential reservoir species, animal models, and the risk to pets, wildlife, and livestock. While there is evidence that certain species, such as cats, are susceptible, the vast majority of animal species, including those in close contact with humans, have unknown susceptibility. Hence, methods to predict their infection risk are urgently needed. SARS-CoV-2 spike protein binding to angiotensin converting enzyme 2 (ACE2) is critical for viral cell entry and infection. Here we identified key ACE2 residues that distinguish susceptible from resistant species using in-depth sequence and structural analyses of ACE2 and its binding to SARS-CoV-2. Our findings have important implications for identification of ACE2 and SARS-CoV-2 residues for therapeutic targeting and identification of animal species with increased susceptibility for infection on which to focus research and protection measures for environmental and public health.

[Progress in the application of exposomics in risk assessment of environmental chemicals]

With the increasing number of environmental chemicals, the risk assessment system based on animal toxicity testing is difficult to satisfy the current demands and needs to be reformed urgently. With the wide application of high-throughput screening technology, the advantage of exposomics in risk assessment is gradually emerging. Exposomics aims to study the health effects of mixed environmental exposure at different stages of life (especially in the early stage of life) through the dynamic monitoring of external and internal exposure levels. Exposomics is introduced into risk assessment to systematically study gene-environment interaction so as to provide a reliable basis for the construction of exposure-biomarker-disease network. This review summarized the importance and application prospect of exposomics in risk assessment of environmental chemicals in terms of the research progress, application in risk assessment and existing problems, opportunities and challenges.