Objective:To access the feasibility and efficacy of percutaneous endoscopic debridement (PED) combined with percutaneous pedicle screw fixation (PPSF) in the treatment of lumbar pyogenic spondylodiscitis.Methods:49 patients (male 29, female 20), aged 51.2±13.9 years (range 19-81 years), who were diagnosed with lumbar pyogenic spondylodiscitis and received PED with PPSF in Orthopedic Department, Sun Yat-Sen Memorial Hospital and Zhuhai People's Hospital from January 2014 to March 2017, were retrospectively reviewed. The patients were operated in the prone position with the infected locus thoroughly debrided, vertebrae fixed and clinical outcomes were assessed by observing the changes of complaining symptoms, laboratory parameters, clinical functional scores (American Spinal Injury Association impairment scale, AIS; visual analog scale, VAS; Oswestry disability index, ODI) and imaging studies during perioperative and follow-up stages.Results:The mean operative time was 110.1±19.8 min (80-165 min), with intra-operative blood loss 47.8±20.6 ml (range 20-120 ml). All patients reported relief of back pain. Causative pathogens were identified in 36 of 49 biopsy specimens, with staphylococcal bacteria being the most prevalent strain (accounting for 50.0%). During 3-12 months' follow-up, 95.9% (47/49) patients' infection was well-controlled. At 3 month post-operative, C-reactive protein declined from 62.1±37.2 mg/L to 7.5±5.8 mg/L, white blood cell declined from (14.2±3.9)×10 9/L to (6.2±1.1)×10 9/L, ESR declined from 90.3±37.4 mm/1 h to 16.9±7.2 mm/1 h, and the values at 3 months post-operative had significant difference compared with values at pre-operative ( t=10.15, P<0.001; t=13.49, P<0.001; t=13.82, P<0.001). Spontaneous fusion was observed among 56.8% (21/37) of the patients during long-term radiological follow-ups (more than 1.5 years). At the last follow-up, the VAS declined from 7.4±0.6 points pre-operative to 0.5±0.3 post-operative, ODI declined from 78.2%±9.1% pre-operative to 14.0%±8.6% post-operative, and the values at the last follow-up had significant difference compared with values at pre-operative ( t=72.00, P<0.001; t=35.89, P<0.001). There were 38 cases of AIS E, and 11 cases of AIS D at pre-operative, while 43 cases of AIS E and 6 cases of AIS D. However, there were 11 patients developed post-operative complications, among whom 2 with recurrent infection, 2 with secondary neurological impairment. Conclusion:PED combined with PPSF effectively eliminated infected locus, stabilized the affected vertebrae, improved patients' clinical outcomes with small trauma, thereby offering an alternative for the treatment of lumbar pyogenic spondylodiscitis.

Objective An approach for analysis of hepatitis C virus (HCV) quasispecies using Hiseq high-throughput sequencing (hereinafter referred to as Hiseq sequencing) technique was developed and then applied to investigate a possible case of HCV needle sharing transmission. Methods One case of HCV antibody seroconversion (P1) was found in a methadone clinic on January 15, 2015. Four HCV antibody positive injecting drug users (IDUs), P2 to P5, suspected to be involved in needle sharing transmission with P1 during the period (after March 24, 2014) that P1 may be infected with HCV were investigated, and another 28 HCV antibody positive IDUs were selected as controls (C1 to C28). These controls came from the same methadone clinic or lived in the same town with P1. The RNAs were extracted from the plasma specimens and then reverse-transcribed into cDNA. After HCV subtyping, Hiseq sequencing was performed to detect and sequence the HCV quasispecies (263 bp) in the specimens with the same subtype as P1. The frequency of quasispecies was counted and ranked. Intrapersonal and interpersonal genetic distance and phylogenetic tree were calculated. Results The HCV subtype of specimen P1 was 3b. All the other specimens with the same subtype were P2, C7, C12, C14, C15, C16, C19, C20 and C28. Hiseq sequencing was successfully performed in 9 out of these 10 specimens, and 249 753 to 1 086 333 (average 869 608) cleaned sequences representing 3 to 172 (average 48) unique HCV quasispecies were obtained. The medians (P50) of intrapersonal genetic diversities from the 9 specimens were 0.4% to 12.3%. The P50 (P25, P75) of genetic diversities between P1 and the other 8 specimens were 19.0% (18.4%, 19.8%), 10.4%(2.8%, 18.3%), 19.6% (17.8%, 21.4%),24.9% (23.8%, 26.1%), 19.8% (18.7%, 20.7%), 20.1% (18.9%, 21.2%), 20.6% (20.0%, 21.1%), 23.6% (22.4%, 24.8%). There were no significant difference between the genetic diversities of P1 and P2 and those of P1 and other 7 specimens (H=9.40, P=0.100). The genetic diversities between few HCV quasispecies from P1 and few ones from C7 were 0. Phylogenetic tree analysis indicated that there was no HCV transmission relationship between P1 and P2, but there was HCV transmission relationship between P1 and C7. Conclusion With the feature of high-throughput, easier operation and lower cost, Hiseq sequencing technique has high practical value in tracing HCV transmission at the quasispecies level.

Objective An approach for analysis of hepatitis C virus (HCV) quasispecies using Hiseq high-throughput sequencing (hereinafter referred to as Hiseq sequencing) technique was developed and then applied to investigate a possible case of HCV needle sharing transmission. Methods One case of HCV antibody seroconversion (P1) was found in a methadone clinic on January 15, 2015. Four HCV antibody positive injecting drug users (IDUs), P2 to P5, suspected to be involved in needle sharing transmission with P1 during the period (after March 24, 2014) that P1 may be infected with HCV were investigated, and another 28 HCV antibody positive IDUs were selected as controls (C1 to C28). These controls came from the same methadone clinic or lived in the same town with P1. The RNAs were extracted from the plasma specimens and then reverse-transcribed into cDNA. After HCV subtyping, Hiseq sequencing was performed to detect and sequence the HCV quasispecies (263 bp) in the specimens with the same subtype as P1. The frequency of quasispecies was counted and ranked. Intrapersonal and interpersonal genetic distance and phylogenetic tree were calculated. Results The HCV subtype of specimen P1 was 3b. All the other specimens with the same subtype were P2, C7, C12, C14, C15, C16, C19, C20 and C28. Hiseq sequencing was successfully performed in 9 out of these 10 specimens, and 249 753 to 1 086 333 (average 869 608) cleaned sequences representing 3 to 172 (average 48) unique HCV quasispecies were obtained. The medians (P50) of intrapersonal genetic diversities from the 9 specimens were 0.4% to 12.3%. The P50 (P25, P75) of genetic diversities between P1 and the other 8 specimens were 19.0% (18.4%, 19.8%), 10.4%(2.8%, 18.3%), 19.6% (17.8%, 21.4%),24.9% (23.8%, 26.1%), 19.8% (18.7%, 20.7%), 20.1% (18.9%, 21.2%), 20.6% (20.0%, 21.1%), 23.6% (22.4%, 24.8%). There were no significant difference between the genetic diversities of P1 and P2 and those of P1 and other 7 specimens (H=9.40, P=0.100). The genetic diversities between few HCV quasispecies from P1 and few ones from C7 were 0. Phylogenetic tree analysis indicated that there was no HCV transmission relationship between P1 and P2, but there was HCV transmission relationship between P1 and C7. Conclusion With the feature of high-throughput, easier operation and lower cost, Hiseq sequencing technique has high practical value in tracing HCV transmission at the quasispecies level.