Epidemiological and Genomic Analysis of SARS-CoV-2 in Ten Patients from a Mid-sized City outside of Hubei, China

A novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing COVID-19 pandemic. In this study, we performed a comprehensive epidemiological and genomic analysis of SARS-CoV-2 genomes from ten patients in Shaoxing, a mid-sized city outside of the epicenter Hubei province, China, during the early stage of the outbreak (late January to early February, 2020). We obtained viral genomes with > 99% coverage and a mean depth of 296X demonstrating that viral genomic analysis is feasible via metagenomics sequencing directly on nasopharyngeal samples with SARS-CoV-2 Real-time PCR Ct values less than 28. We found that a cluster of 4 patients with travel history to Hubei shared the exact same virus with patients from Wuhan, Taiwan, Belgium and Australia, highlighting how quickly this virus spread to the globe. The virus from another cluster of two family members living together without travel history but with a sick contact of a confirmed case from another city outside of Hubei accumulated significantly more mutations (9 SNPs vs average 4 SNPs), suggesting a complex and dynamic nature of this outbreak. We also found 70% patients in this study had the S genotype, consistent with an early study showing a higher prevalence of genotype out of Hubei than that inside Hubei. We calculated an average mutation rate of 1.37x10-3 nucleotide substitution per site per year, which is similar to that of other coronaviruses. Our findings add to the growing knowledge of the epidemiological and genomic characteristics of SARS-CoV-2 that are important for guiding outbreak containment and vaccine development. The moderate mutation rate of this virus also lends hope that development of an effective, long-lasting vaccine may be possible.

Two different methods of free iliac flap grafting in the repair of tibial defect / 中华整形外科杂志

Objcetive@#To explore the treatment of long segment defect of tibia by using tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle iliac flap.@*Methods@#From February 2012 to August 2017, The People′s Hospital of Zun Yi City Bo Zhou District treated 16 patients who had long segment defect of tibia.There were 11 males and 5 females, age from 22 to 58 years old, the average age was 42 years old. Iliac flap grafting with tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle was used to treat the defect of long segment of tibia. There were 4 cases with simple tibial defect and 12 cases with skin defect. The longest tibial defect was 5-8 cm.@*Results@#In this study, four patients used iliac flaps with deep circumflex iliac pedicle, the area of flaps ranged from 2.5 cm×5.0 cm to 5.0 cm×10.0 cm, while the area of iliac flaps ranged from 5.0 cm×2.5 cm to 8.0 cm×4.0 cm. Twelve patients used grafting with tensor fascia lata combined with iliac flap, the area of flaps ranged from 5.0 cm×12.0 cm to 12.0 cm×23.0 cm, while the area of iliac flaps ranged from 7.0 cm×2.0 cm to 8.0 cm×4.0 cm. All 16 cases of bone flap were survived, fracture healing, without surgical complications. The average follow-up period was 1.5 years, the flaps had good appearance in 10 cases and was slightly bloated in 6 cases; the ankle had normal motion in 14 cases and had poor dorsal extension in 2 cases. X-ray films showed that the bone flap repaired the bone defects and reached bone healing.@*Conclusions@#Vascularized tensor fascia lata combined with iliac flap or deep circumflex iliac pedicle iliac flap grafts increase local blood supply and accelerate the process of fracture healing.

PAF-AH and PLA2 activity of Leptospira interrogans LA_2144 gene product / 中华微生物学和免疫学杂志

Objective To analyze the enzymatic activity of Leptospira interrogans ( L. interrogans) LA_2144 gene product to hydrolyze platelet activating factor acetylhydrolase ( PAF-AH) and phosphatidase A2(PLA2). Methods Bioinformatic softwares were used to predict transmembrane regions, signal peptides and domains of the LA_2144 gene of L. interrogans strain Lai. A prokaryotic expression system for signal peptide-free LA_2144 gene was established. The expressed target recombinant protein rLep2144 was extrac-ted by Ni-NTA affinity chromatography and then renatured. Spectrometry was used to detect the activity of rLep2144 to hydrolyze PAF-AH substrate 2-thio PAF and the Km and Kcat values as well as the activity to hy-drolyze PLA2 substrate arachidonoyl 2-thio PC. Real-time fluorescence quantitative RT-PCR and Western blot were performed to detect the transcription, protein expression and secretion of LA_2144 gene during infection of human and mouse vascular endothelial cells ( HUVEC and EOMA) with L. interrogans. Results L. interrogans LA_2144 gene contained a signal peptide and a domain belonging to SGNH hydrolase super-family, but no transmembrane regions. The established prokaryotic expression system for signal peptide-free LA_2144 gene could efficiently express rLep2144. The extracted rLep2144 was shown as a single protein fragment in separation gel and then successfully renatured. rLep2144 had a stronger PAF-AH activity with the Km and Kcat values of 688. 235 μmol/L and 0. 976/s, but its PLA2 activity was relatively weak. Expres-sion of the LA_2144 gene at mRNA and protein levels in HUVEC and EOMA was rapidly increased after the cells were infected with L. interrogans (P<0. 05) and the secretion of LA_2144 gene product could be detec-ted. Conclusions L. interrogans LA_2144 gene product had a stronger PAF-AH and a certain PLA2 activi-ty, which might involve in the hemorrhage and inflammatory response in leptospirosis.