[Progress in research of 2019-nCoV Omicron variant].

2019-nCoV Omicron (B.1.1.529) variant, which has brought new challenges to the prevention and control of COVID-19 pandemic, has the characteristics of stronger transmissibility and more rapid transmission and more significant immune evasion. It took only two months to become a predominant strain worldwide after its identification in South Africa in November 2021. Local epidemics caused by Omicron variant have been reported in several provinces in China. However, the epidemiological characteristics of highly mutated Omicron variant remain unclear. This article summarizes the progress in the research of functional mutations, transmissibility, virulence, immune evasion and cross-reactive immune responses of Omicron variant, to provide references for the effective prevention and control of COVID-19 pandemic caused by Omicron variant.

[Epidemiological characteristics of local COVID-19 epidemics and control experience in routine prevention and control phase in China].

The COVID-19 pandemic is still ongoing in the world, the risk of COVID-19 spread from other countries or in the country will exist for a long term in China. In the routine prevention and control phase, a number of local COVID-19 epidemics have occurred in China, most COVID-19 cases were sporadic ones, but a few case clusters or outbreaks were reported. Winter and spring were the seasons with high incidences of the epidemics; border and port cities had higher risk for outbreaks. Active surveillance in key populations was an effective way for the early detection of the epidemics. Through a series of comprehensive prevention and control measures, including mass nucleic acid screening, close contact tracing and isolation, classified management of areas and groups at risk, wider social distancing and strict travel management, the local COVID-19 epidemics have been quickly and effectively controlled. The experiences obtained in the control of the local epidemics would benefit the routine prevention and control of COVID-19 in China. The occurrence of a series of COVID-19 case clusters or outbreaks has revealed the weakness or deficiencies in the COVID-19 prevention and control in China, so this paper suggests some measures for the improvement of the future prevention and control of COVID-19.

[A ten-year follow-up study of a patient with chronic renal failure and metastatic pulmonary calcification after parathyroidectomy and review of the literature].

Objective: To analyze whether parathyroidectomy can prevent the progress of metastatic pulmonary calcification (MPC) in patients with chronic renal failure (CRF). Methods: A male patient with CRF complicated with MPC who underwent parathyroidectomy for secondary hyperparathyroidism and parathyroid adenoma was followed up for 10 years. The changes of MPC and the levels of blood calcium and phosphorus were measured. We searched the relevant literatures in PubMed and Wanfang databases with the key words of "metastatic pulmonary calibration" and "parathyroidectomy". Then, we manually retrieved the references of the literatures. A total of 18 patients (17 patients from 14 publications as well as the present case) were analyzed. By comparing the characteristics of MPC improvement group and MPC progression group, the factors affecting the prognosis of MPC after parathyroidectomy were explored. Results: After parathyroidectomy, the thoracic CT images of the patient gradually worsened from normal to diffuse ground glass opacity of both lungs, which indicated that parathyroidectomy did not prevent the progression of MPC in this patient. Among the 18 MPC patients who underwent parathyroidectomy, 10 patients had improved MPC, three had CRF, and two received peritoneal dialysis or hemodialysis respectively; eight patients had progressed MPC, all of the patients were CRF patients, one patient received peritoneal dialysis, and other patients received hemodialysis. Compared between the two groups, the proportion of CRF patients (P=0.004) and hemodialysis patients (P=0.003) in the progression group were significantly higher than those in the improvement group. Conclusion: Parathyroidectomy cannot prevent the progression of MPC in hemodialysis patients with CRF.

[Treatment strategies and research progress of acute ilio-femoral deep vein thrombosis].

In the past,treatment of acute ilio-femoral deep vein thrombosis (IFDVT) was mainly based on anticoagulation alone,but 30%-50% of patients will develop post-thrombotic syndrome,causing a serious medical burden.Thrombus removal technology such as catheter-directed thrombolysis and percutaneous mechanical thrombectomy can effectively remove blood clots and compensate for the deficiencies of simple anticoagulation,which is expected to improve the prognosis of such disease,but the current evidence is insufficient,and other treatments such as filter implantation and compression therapy are also controversial.This article summarizes the treatment strategies and the latest progress of acute IFDVT,hoping to help the treatment of this type of disease.

[Comparison of two epidemic patterns of COVID-19 and evaluation of prevention and control effectiveness: an analysis based on Guangzhou and Wenzhou].

Objective: To compare the epidemiological characteristics of COVID-19 in Guangzhou and Wenzhou, and evaluate the effectiveness of their prevention and control measures. Methods: Data of COVID-19 cases reported in Guangzhou and Wenzhou as of February 29, 2020 were collected. The incidence curves of COVID-19 in two cities were constructed. The real time reproduction number (R(t)) of COVID-19 in two cities was calculated respectively. Results: A total of 346 and 465 confirmed COVID-19 cases were analysed in Guangzhou and Wenzhou, respectively. In two cities, most cases were aged 30-59 years (Guangzhou: 54.9%; Wenzhou: 70.3%). The incidence curve peaked on 27 January, 2020 in Guangzhou and on 26 January, 2020 in Wenzhou, then began to decline in both cities. The peaks of imported COVID-19 cases from Hubei occurred earlier than the peak of COVID-19 incidences in two cities, and the peak of imported cases from Hubei occurred earlier in Wenzhou than in Guangzhou. In early epidemic phase, imported cases were predominant in both cities, then the number of local cases increased and gradually took the dominance in Wenzhou. In Guangzhou, the imported cases was still predominant. Despite the different epidemic pattern, the R(t) and the number of COVID-19 cases declined after strict prevention and control measures were taken in Guangzhou and in Wenzhou. Conclusion: The time and scale specific differences of imported COVID-19 resulted in different epidemic patterns in two cities, but the spread of the disease were effectively controlled after taking strict prevention and control measures.

[Risk assessment and early warning of imported COVID-19 in Guangdong province].

Objective: To assess the imported risk of COVID-19 in Guangdong province and its cities, and conduct early warning. Methods: Data of reported COVID-19 cases and Baidu Migration Index of 21 cities in Guangdong province and other provinces of China as of February 25, 2020 were collected. The imported risk index of each city in Guangdong province were calculated, and then correlation analysis was performed between reported cases and the imported risk index to identify lag time. Finally, we classified the early warming levels of epidemic by imported risk index. Results: A total of 1 347 confirmed cases were reported in Guangdong province, and 90.0% of the cases were clustered in the Pearl River Delta region. The average daily imported risk index of Guangdong was 44.03. Among the imported risk sources of each city, the highest risk of almost all cities came from Hubei province, except for Zhanjiang from Hainan province. In addition, the neighboring provinces of Guangdong province also had a greater impact. The correlation between the imported risk index with a lag of 4 days and the daily reported cases was the strongest (correlation coefficient: 0.73). The early warning base on cumulative 4-day risk of each city showed that Dongguan, Shenzhen, Zhongshan, Guangzhou, Foshan and Huizhou have high imported risks in the next 4 days, with imported risk indexes of 38.85, 21.59, 11.67, 11.25, 6.19 and 5.92, and the highest risk still comes from Hubei province. Conclusions: Cities with a large number of migrants in Guangdong province have a higher risk of import. Hubei province and neighboring provinces in Guangdong province are the main source of the imported risk. Each city must strengthen the health management of migrants in high-risk provinces and reduce the imported risk of Guangdong province.

[Risk assessment of exported risk of COVID-19 from Hubei Province].

Objective: To evaluate the exported risk of COVID-19 from Hubei Province and the imported risk in various provinces across China. Methods: Data of reported COVID-19 cases and Baidu Migration Indexin all provinces of the country as of February 14, 2020 were collected. The correlation analysis between cumulative number of reported cases and the migration index from Hubei was performed, and the imported risks from Hubei to different provinces across China were further evaluated. Results: A total of 49 970 confirmed cases were reported nationwide, of which 37 884 were in Hubei Province. The average daily migration index from Hubei to other provinces was 312.09, Wuhan and other cities in Hubei were 117.95 and 194.16, respectively. The cumulative COVID-19 cases of provinces was positively correlated with the migration index derived from Hubei Province, also in Wuhan and other cities in Hubei, with correlation coefficients of 0.84, 0.84, and 0.81. In linear model, population migration from Hubei Province, Wuhan and other cities in Hubei account for 71.2%, 70.1%, and 66.3% of the variation, respectively. The period of high exported risk from Hubei occurred before January 27, of which the risks before January 23 mainly came from Wuhan, and then mainly from other cities in Hubei. Hunan Province, Henan Province and Guangdong Province ranked the top three in terms of cumulative imported risk (the cumulative risk indices were 58.61, 54.75 and 49.62 respectively). Conclusion: The epidemic in each province was mainly caused by the importation of Hubei Province. Taking measures such as restricting the migration of population in Hubei Province and strengthening quarantine measures for immigrants from Hubei Province may greatly reduce the risk of continued spread of the epidemic.

[Evaluation of an automatic image-based screening technique for neonatal hyperbilirubinemia].

OBJECTIVE: To verify the accuracy of a smart phone software application, which is an automated image-based bilirubin (AIB) testing technique for testing peripheral blood total bilirubin (TB) in term and late preterm neonates. METHOD: During July 2015 to January 2016, jaundiced neonates were enrolled from department of neonatology in Tongji Hospital, Children's Hospital of Zhejiang University School of Medicine and Shenzhen Bao'an Maternal and Child Health Hospital. The enrolling criteria included gestational age (GA)≥34 weeks and peripheral blood total bilirubin test is required. Near-simultaneous TB, transcutaneous bilirubin (TcB), and AIB were determined. AIB consists of a cloud based off-line learning module and an on-line prediction module. Skin image, by smart phone is uploaded to a specific cloud server that includes learning based software to provide an individualized and immediate predicted bilirubin index. The t-test was used to determine if AIB and peripheral blood TB are significantly different. Agreement of AIB and TcB were compared with peripheral blood TB by Bland-Altman analysis. Linear regression was adopted to model the relationship of AIB and peripheral blood TB. The ROC curve of AIB was also plotted. RESULT: Two hundred and fifteen neonates were enrolled, gestational age 37 weeks+ 5 d, postnatal age (11±4) d, weight (2.9±0.7) kg, 116 male and 99 female. One hundred and forty-eight term neonates (GA≥37 weeks) and 67 preterm neonates (GA 34-<37 weeks) were enrolled in this study. There was no significant difference between AIB (197±51)µmol/L and peripheral blood TB(191±65)µmol/L (t=1.611, P=0.109). There was strong relevance between peripheral blood TB and AIB as shown by Bland-Altman analysis (96% (207/215) samples lay within the 95% limits of agreement). The regression analysis showed that the r(2) was 0.593 in the whole population, while the r(2) was 0.628 in the term neonates. The ROC of AIB yielded a 0.743 AUC, and with 82% sensitivity and 60% specificity based on Youden index criterion. CONCLUSION: Based on AIB's agreement with peripheral blood TB, the sensitivity and specificity, AIB can be used as a new technique to provide results for objective follow-up for progression and regression of jaundice.

Molecular cloning and characterization of a novel chicken gene named grni.

The full-length cDNA sequence of a novel expressed sequence tag (GenBank accession No. HQ184338) that was differentially expressed during Newcastle disease virus (NDV) infection in chickens was cloned from the chicken spleen by a rapid amplification of cDNA ends assay. This gene was further analyzed using bioinformatic methods and named grni. The full-length cDNA sequence was 1698 bp without introns, locating between 104,691,934 and 104,693,618 in galGal4 on chromosome 2. The open reading frame (ORF) contained 261 bp and encoded a deduced protein of 86 amino acid residues. Furthermore, the encoded protein contained two transmembrane regions without signal peptides, indicating that this protein is located in the mitochondrial membrane. Moreover, its homologous protein was not identified. Real-time polymerase chain reaction was used to detect the dynamic mRNA expression of this gene in the spleen, thymus, bursa of Fabricius, and trachea of NDV-infected chickens. Results suggested that the gene was involved in the transcriptional response of chicken to NDV infection. To obtain a fusion protein and prepare rabbit anti-serum, the predicted ORF of this gene was expressed in Escherichia coli. The expression of this gene at the protein level was further confirmed in the spleen, thymus, and bursa of Fabricius of NDV-infected chickens using Western blot analysis. In conclusion, a novel protein-coding gene named grni was successfully cloned and identified in chickens. Furthermore, this gene was found to be involved in the response of chickens to NDV infection.

KL-6 regulated the expression of HGF, collagen and myofibroblast differentiation.

OBJECTIVES: KL-6 is a pulmonary epithelial-derived mucin which is secreted mainly by type II alveolar epithelial cells. The level of KL-6 in serum is closely correlated to the clinical activity of various interstitial lung diseases (ILD) and acts as a prognostic factor for ILD patients. Previous studies have showed that KL-6 promoted chemotaxis, proliferation and inhibited the apoptosis of human lung fibroblasts. However, the underlying mechanism remains unknown. In this study, we investigated the function of KL-6 on the expression of hepatocyte growth factor (HGF), transforming growth factor-ß1 (TGF-ß1), collagen and α-smooth muscle actin(α-SMA) in human embryonic lung fibroblasts cell line MRC-5. METHODS: Human embryonic lung fibroblasts were cultured in Eagle's minimum essential medium. The cells plated in 6-well plates was cultured in serum-free medium at 37°C in 5% CO2 and challenged with recombinant KL-6 at a final concentration of 0, 10, 20, 40 ng/mL. Five micrograms of total RNA template were transcripted to cDNA by using AMV (Avian Myeloblastosis Virus) reverse transcriptase and random 9 mers as the first-strand primer. Synthesized cDNA was used in PCR experiments. The expression of TGF-ß1 and HGF in cell culture supernatants was measured using ELISA kit. Cells incubated with KL-6 for 72h were collected for flow-cytometry analysis. The analysis was done using a Beckman counter device. RESULTS: It was found that KL-6 up-regulated the expression of collagen type I and III in a dose-dependent manner. However, the addition of KL-6 significantly inhibited the production of HGF. As regard to the biological function, KL-6 induced myofibroblast differentiation confirmed by the elevated expression of a-SMA. CONCLUSIONS: KL-6 is one of the key molecules involved in epithelial-mesenchymal interactions and might contribute to the fibrosis in ILD.