Treponema pallidum(Tp),a common sexually transmitted pathogen,can infect the fetus via pla-cental vertical transmission,leading to congenital syphilis(CS).This infection results in adverse pregnancy outcomes,such as stillbirth,miscarriage,preterm birth,and fetal growth restriction.However,the exact pathogenesis remains un-clear.Studies indicate that patients with early syphilis primarily exhibit pro-inflammatory immune responses.The Tp has been proven to induce dysfunction in various immune cells and abnormal expression of cytokines,potentially disrupting im-mune tolerance homeostasis and leading to adverse pregnancy outcomes.Grounded in the current understanding of CS and maternal-fetal immunology by scholars both domestically and internationally,this paper provides a comprehensive review of the potential mechanisms of Tp interacting with the cells of the maternal-fetal interface,ultimately leading to adverse pregnancy outcomes.It summarizes the pathogenesis characteristics,clinical manifestations,and maternal-fetal immune responses of CS.

The oblique lumbar interbody fusion (OLIF) procedure has yielded favorable outcomes for individuals afflicted with degenerative lumbar conditions; however, certain complications warrant attention. We present a case of a 48-year-old female experiencing recurrent radicular pain post-OLIF. This patient, who endured persistent lower back discomfort for a decade, underwent MRI scans which revealed an intervertebral disc herniation at the L 4, 5 level and L 4 spondylolisthesis. The length of the right upper articular process of L 5 was 10.46 mm, and the distance between right upper articular process of L 5 and right nerve root of L 4 was 1.34 mm. Subsequent to OLIF, she reported recurrent radicular pain in her right leg. Post-operative CT scans revealed that the inclination of the right upper articular process of L 5 augmented from 59.46° to 65.22°. The distance from this process to the anterior foramen wall diminished from 0.63 mm to 0.25 mm, while its distance from the superior wall expanded from 0.31 mm to 0.39 mm. Furthermore, the foraminal cross-sectional area decreased from 0.29 mm 2 to 0.18 mm 2, and the lordotic angle of the intervertebral space amplified from 0.52° to 7.33°. Such measurements suggest that following OLIF, there was asymmetric retraction of the intervertebral space, accompanied by an anteroinferior tilt of the upper articular process, leading to persistent nerve root compression and thus necessitating immediate surgical nerve root decompression. This paper also elucidates the influence of the anatomical characteristics of the facet joint or articular process on lumbar functionality. Consequently, it could be postulated that hypertrophic or aberrantly elongated articular processes might induce nerve root compression due to intervertebral space retraction post-OLIF. Hence, spine surgeons should diligently assess and recognize the ramifications of such anomalies on OLIF surgical outcomes.

Objective:To investigate the short-term clinical outcomes of posterior percutaneous pedicle screw fixation combined with percutaneous vertebroplasty (PVP) for treating Kümmell's disease with intravertebral instability.Methods:A retrospective case series study was made on 18 patients with Kümmell's disease with intravertebral instability treated at Lishui Hospital of Zhejiang University from January 2012 to February 2016. There were 4 males and 14 females, aged 65-86 years [(76.0±5.5)years]. Segment of injury was T 7 in 1 patient, T 10 in 2, T 11 in 3, T 12 in 4, L 1 in 6, and L 2 in 2. All patients underwent posterior percutaneous pedicle screw fixation combined with PVP. The operation time, intraoperative blood loss, amount of cement injected into the vertebra, and length of postoperative hospital stay were recorded. The visual analogue scale (VAS), Oswestry disability index (ODI), Cobb angle, and wedge angle of the operative segment were recorded and compared preoperatively, postoperatively, and at the latest follow-up. Meanwhile, the complications were recorded. Results:All patients were followed up for 12-28 months [(17.7±4.4)months]. The operation time was 110-175 minutes [(137.9±21.9)minutes] and the blood loss was 50-165 ml [(110.7±35.6)ml]. The amount of cement injected into the vertebra was 2.5-6.0 ml [(4.7±0.9)ml]. The length of hospital stay was 7-14 days [(9.4±2.3)days]. The VAS was (7.8±1.2) points preoperatively, (3.3±0.7) points at 1 week postoperatively and (2.4±0.7)points at the latest follow-up. The ODI was (67.3±7.3)% preoperatively, (30.5±7.5)% at 1 week postoperatively and (21.8±8.3)% at the latest follow-up. The Cobb angle was (26.2±9.5)° preoperatively, (12.6±7.2)° at 1 week postoperatively and (16.7±6.2)°at the latest follow-up. The wedge angle was (21.1±6.1)° preoperatively, (8.4±4.6)° at 1 week postoperatively, and (13.2±4.1)° at the latest follow-up. The above clinical and radiological parameters were significantly improved after operation ( P<0.05), and showed no significant differences at the latest follow-up when compared to that at 1 week postoperatively ( P>0.05). Five patients showed slight screw loosening, but there was no obvious dislocation of internal fixation. One case developed distal vertebral compression fracture at 6 months postoperatively and cured after a second PVP. Conclusion:For Kümmell's disease with intravertebral instability, posterior percutaneous pedicle screw fixation combined with PVP can effectively restore and maintain the spinal sequence, rapidly relieve the pain and improve clinical function. However, the long-term efficacy needs further study.

Objective:To investigate the preliminary clinical and radiographic outcomes of percutaneous endoscopic lumbar discectomy (PELD) combined with oblique lateral interbody fusion (OLIF) for the degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation.Methods:Data of 11 patients with degenerative lumbar spondylolisthesis, lumbar spine instability or lumbar spinal stenosis with ruptured disc herniation who had undergone PELD combined with OLIF between March 2017 to July 2018 in our spine surgery center were retrospectively analyzed. There were 5 males and 6 females with an average age of 61.2±6.8 years old. All the patients were diagnosed with degenerative lumbar diseases including lumbar spondylolisthesis (7 cases), lumbar spinal stenosis (3 cases) and segmental instability (1 case). The patients were treated with PELD combined with OLIF. The visual analogue scale (VAS) scores of low back pain and lower limb pain and the Oswestry disability index (ODI) of lumbar function, spinal canal anteroposterior diameter, intervertebral disc height, vertical diameter of intervertebral foramen, segmental angle and the whole lumbar lordotic angle were collected.Results:All patients received PELD with local anesthesia before OLIF with general anesthesia. The mean operation time was 52.3±13.2 min and the mean blood loss was 10.9±4.7 ml for PELD. The mean operation time was 56.8±18.0 min and the mean blood loss was 65.5±24.6 ml for OLIF. All patients were followed up for an average of 11.2 months. At the latest follow-up, the mean VAS score for back pain was 1.3±0.8, the mean VAS score for leg pain 1.1±0.5, the mean ODI 14.6%±5.3%, thus all of those were improved significantly compared to those of pre-operation ( t=10.37, 16.49, 8.73; P< 0.05). The radiographic results showed the mean pre-operative intervertebral disc height, vertical diameter of intervertebral foramen, spinal canal anteroposterior diameter, segmental angle, and lumbar lordosis angle was 7.1±1.2 mm, 15.3±2.2 mm, 6.2±1.3 mm, 10.2°±3.5°, 16.2°±6.2°, and thus all of those were increased significantly to the latest follow-up 11.5±1.8 mm, 19.2±2.6 mm, 10.4±2.5 mm, 19.3°±7.8°, 27.4°±8.3°, respectively ( t=5.83, 4.21, 6.59, 10.32, 7.65; P< 0.05). One of the patients had weakness of flexor hip strength and one had a transient paresthesia immediately post-operation. All symptoms were relieved within 1 month. Another one case had cage subsidence and encountered serious back pain after 1 month, and alleviated after percutaneous pedicle screw fixation. Conclusion:PELD combined with OLIF can overcome the limitations of OLIF with indirect decompression effects, resulting in successful direct neural decompression without posterior decompressive procedures and providing a satisfactory outcome for the patients with degenerative lumbar diseases with ruptured disc herniation.

Objective To screen and identify the in vivo-induced antigen Tp0462 of Treponema pallidum (Tp),and to evaluate its value for clinical serological diagnosis of syphilis.Methods Genomewide DNA was extracted from the Tp Nichols strain,and polymerase chain reaction (PCR) was performed to amplify the Tp0462 gene.A recombinant plasmid pET30a (+)-Tp0462 was constructed and transfected into the Escherichia coli (E.coli) Rosetta (DE3) strain.Recombinant protein Tp0462 was abundantly expressed,purified and identified.A total of 18 New Zealand rabbits were randomly and equally divided into 3 groups:viable Tp-incubating group incubated with viable Tp in the testes,inactived Tp-incubating group incubated with ultraviolet irradiation-killed Tp in the testes,and control group receiving no treatment.After incubation,blood samples were collected at different time points,and the sera were isolated for identification of characteristics of in vivo-induced antigen Tp0462.Enzyme-linked immunosorbent assay for Tp0462 (Tp0462-ELISA),Treponema pallidum particle agglutination assay (TPPA),preliminary syphilis screening ELISA and rapid plasma reagin (RPR) card test were applied in 336 clinical serum samples from patients with syphilis,so as to preliminarily evaluate the value of Tp0462 for the diagnosis of syphilis.Results The optimum conditions for expression of the recombinant plasmid Tp0462-pET30a(+) in E.coli Rosetta (DE3) strains were the treatment with 0.5 mmol/L isopropyl thiogalactoside (IPTG) on a shaker at 180 rpm for 4 hours.In the viable Tp-incubating group,the serum level of specific anti-Tp0462 antibody sharply increased from week 2,and went steady after week 5.However,the specific anti-Tp0462 antibody maintained a low level in the inactived Tp-incubating group and the control group.The viable Tp-incubating group showed a significantly higher level of specific anti-Tp0462 antibody compared with the inactived Tp-incubating group and the control group (both P ＜ 0.05),while no significant difference was observed between the inactived Tp-incubating group and the control group (P =0.256).The level of anti-Tp92 antibody was significantly higher in the viable Tp-incubating group and the inactived Tp-incubating group than in the control group (P ＜ 0.05),while there was no significant difference between the viable Tp-incubating group and the inactived Tp-incubating group (P =0.127).Compared with TPPA,the sensitivity,specificity,consistency rate and area under the curve (AUC) of Tp0462-ELISA for the diagnosis of syphilis were 91.7％,98.8％,95.2％ and 0.997 respectively.Tp0462-ELISA was consistent to preliminary syphilis screening ELISA and RPR with a Kappa coefficient of 0.846 and 0.293,respectively.Conclusion Tp0462-ELISA has shown evidently higher sensitivity and specificity in the serodiagnosis of syphilis,and Tp0462 can serve as promising antigens for the diagnosis of syphilis.

Objective To evaluate immune protective effects of Treponema pallidum(Tp)pcD/Tp92 DNA vaccine delivered through different inoculation routes against Tp-induced skin infection in New Zealand rabbits. Methods A total of 108 New Zealand rabbits were randomly and equally divided into 6 groups:A1 and A2 groups treated with intramuscular injection of empty plasmids pcD and pcD/Tp92 DNA vaccine respectively for 2 sessions, B1, B2, C1 and C2 groups firstly treated with intramuscular injection of the pcD/Tp92 DNA vaccine for 1 session for primary immunization, then receiving nasogastric feeding with pcD/Tp92 DNA vaccine, pcD/Tp92 DNA vaccine+cytosine-phosphate-guanine(CpG)oligodeoxynucleotide (ODN), and recombinant Tp92 protein, and recombinant Tp92 protein+CpG ODN respectively for booster immunization. Enzyme-linked immunosorbent assay(ELISA)was conducted to detect the serum level of anti-Tp92 IgG antibody at week 0, 2, 4, 6, 8 after immunization, the SIgA level in the nasopharyngeal region and vaginal mucosa at week 8 after immunization, as well as levels of interleukin-2(IL-2)and interferon-γ (IFN-γ)in the culture supernatant of rabbit spleen cells at week 8 after immunization, and methyl thiazolyl tetrazolium(MTT)assay was performed to estimate proliferative activity of rabbit splenic lymphocytes in three rabbits from each group. At week 10 after immunization, other 15 rabbits from each group were subcutaneously inoculated with Tp standard strain, and changes of skin lesions at the inoculation site during early-stage infection were observed and recorded. Results At week 8 after immunization, the C2 group showed significantly higher serum level of anti-Tp92 IgG antibody(1.825 ± 0.175), supernatant levels of IL-2 (154.7 ± 14.6)and IFN-γ(277.4 ± 24.4), and proliferative activity of T cells(3.57 ± 0.24)compared with the A2(1.372 ± 0.322, 112.3 ± 13.4, 232.8 ± 25.3, 3.08 ± 0.22, respectively, all P<0.05), B1(0.893 ± 0.297, 76.6 ± 21.5, 165.7 ± 22.6, 2.12 ± 0.14, respectively, all P<0.05)and B2(1.294 ± 0.124, 97.3 ± 18.7, 211.3 ± 24.6, 2.88 ± 0.18, respectively, all P<0.05)groups. In addition, effective immunoprotection was achieved in the C2 group with more production of mucosa-specific SIgA antibody, as well as the lowest Tp-positive rate (6.67%) and ulcer formation rate (6.67%) in skin lesions at the inoculation sites. Conclusion The effective vaccination strategy, namely intramuscular injection of the pcD/Tp92 DNA vaccine for primary immunization followed by nasogastric feeding with mucosal adjuvant CpG ODN combined with recombinant Tp92 protein for booster immunization, can induce the strongest mucosal immune responses and immune protective effects.

Objective To evaluate the clinical effect of interspinous H-shaped bone grafting and bilateral facet interbody fusion in treatment of thoracolumbar fracture with severe disc injury and posterior ligamentous complex (PLC) injury after posterior pedicle screw fixation and its role in prevention of delayed kyphosis.Methods The study involved 19 cases of thoracolumbar fractures with severe disc injury and PLC injury,including 11 males and 8 females,at age of 23-59 years (mean 43.8 years.All cases were treated with posterior pedicle screw fixation (including 11 cases treated with unilateral laminectomy decompression) and C-arm X-ray showed favorable fracture reduction.For prevention of postoperative delayed kyphosis,the interspinous H-shaped bone grafting plus bilateral facet interbody fusion by using the iliac autografts was done.Neurologic recovery was assayed by using Frankel scale and lumbar and iliac pain by visual analogue scale (VAS).Cobb angle was detected as well.Results All cases were followed up for 24-64 months.At final follow-up,all cases showed neurological improvement for at least 1 to 2 Frankel grades except for two cases with Frankel Grade A,with mean Cobb angle of (2.0 ± 3.7) ° (range,-4.9°-8.1 °),mean VAS of lower back pain of (1.1 ± 1.2) points (range,0-4 points) and insignificant angle loss or kyphosis.The thin layer CT scan indicated complete integration of the transplanted bone grafts,with no complications like implant loosening or breakage.Conclusion Interspinous H-shaped bone grafting and bilateral facet interbody fusion is a good choice for prevention of delayed kyphosis after posterior pedicle screw fixation of thoracolumbar fracture with severe disc injury and PLC injury.

Objective To assess the clinical efficacy of minimally invasive internal fixation combined with percutaneous kyphoplasty (PKP) in treatment of thoracolumbar burst fractures in the elderly.Methods Twenty-one cases of neurologically intact thoracolumbar burst fractures treated by PKP between January 2007 and December 2008 were included in this study.There were 8 males and 13 females at age of 65-78 years (means,70.6 years).Mean period from injury to operation was (3.7 ± 1.1) days (range,3-7 days).The injured segments included Ti1 in two cases,T12 in six,L1 in eight and L2 in five.Kphosis Cobb' s angle,correction degree of kyphosis angle,correction loss of kyphosis,perioperative indicators,visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated after operation.Results All the cases were followed up for a period of 26-56 months (mean 34.2 months).Operation averaged 98.7 minutes (range,80-120 minutes) and showed mean blood loss of 32.8 ml (range,30-85 ml).Ambulation started at mean 18.2 hours after operation (range,8-19 hours).VAS averaged (0.9 ± 0.6) points at postoperative one week.Postoperative X-ray films revealed mean 10.4° correction of kyphotic Cobb angle,followed by mean 1.8 °of loss in the follow-up longer than 24 months.According to hyperextension and hyperflexion radiographies,there was no abnormal activity of fixed segments,implant loosening and breakage or adjacent vertebral fractures.Conclusion Minimally invasive internal fixation combined with PKP can relieve pain and restore function in a short time and is thought to be a preferable treatment option for thoracolumbar burst fractures in the elderly.

Objective To investigate the immune response to and protective effect of a bivalent DNA vaccine expressing interleukin-2(IL-2)and Gpd proteins in New Zealand rabbits.Methods Seventy-two male New Zealand white rabbits were equally and randomly divided into 4 groups to be immunized with recombinant plasmids pcDNA3.1(+)/Gpd-IL-2(pcD/Gpd-IL-2),pcDNA3.1(+)/Gpd(pcD/Gpd),empty plasmid pcDNA3.1(+)(pcD)and phosphate buffered saline(PBS),respectively.Immunization was carried out by intramuscular injection at multiple sites with a 2-week interval for 3 times.On week 10 after the initial immunization,the rabbits were challenged intradermally with T.pallidum(Nichols strain).Enzyme-linked immunosorbent assay(ELISA)was used to quantify the serum level of anti-Gpd antibodies in the rabbits and the level of IL-2 and interferon(IFN-γ)in the supernatant of Gpd protein-stimulated spleen cells from the rabbits at different time pionts.MTT assay was conducted to detect the proliferation response of spleen cells collected from the rabbits on day 0,14,28,140 and 168 after the challenge.Results Compared with pcD and PBS,both the vaccines pcD/Gpd and pcD/Gpd-IL-2 elicited significantly higher levels of anti-Gpd IgG antibodies in rabbits at different time points during the vaccination and infection period,with the titers peaking at 1 ∶ 1024 and 1∶4096,respectively(both P ＜ 0.01).There were also significant differences in the serum levels of anti-Gpd IgG antibodies between the pcD/Gpd-and pcD/Gpd-IL-2-immunized rabbits at different time points(all P ＜0.01).The levels of IL-2 in the supematant of spleen cells from pcD/Gpd-and pcD/Gpd-IL-2-immunized rabbits on week 8 after the immunization were 110 ± 12.6 and 167 ± 15.7 μg/L respectively,and those of IFN-γwere 225 ± 17.6 and 447 ± 22.4 μg/L respectively,significantly higher than those in that from the other two groups of rabbits(all P ＜ 0.01).Furthermore,an apparent proliferation response was observed in spleen cells from pcD/Gpd-and pcD/Gpd-IL-2-immunized rabbits with a higher stimulation index compared with pcD-and PBS-immunized rabbits(all P ＜ 0.01).Dark-field microscopic examination of early-stage infected lesions revealed that pcD/Gpd-IL-2-immunized rabbits had a lower detection rate(17.5％)of Tp from lesions,occurrence of ulcerative lesions(15％)and shorter curing time compared with pcD/Gpd-immunized rabbits.Conclusion The recombinant plasmid pcDNA3.1(+)/Gpd-IL-2 could induce protective humoral and cellular immune response more efficiently in rabbits.

Objective To construct a recombinant plasmid encoding Tp0821,a membrane lipoprotein of T. pallidum,express and purify this protein,and to evaluate its immunocompetence.Methods The recombinant plasmid pQE32/Tp0821 was constructed and induced to express the corresponding protein.Then,New Zealand rabbits were immunized with purified recombinant protein to prepare polycional antibodies,and the titer of polyclonal antibody was determinated.Indirect ELISA was developed with the recombinant protein of T. pallidum as coating antigen to detect 80 control sera and 150 FTA-ABS-positive sera.Results The recombinant plasmid pQE32/Tp0821 was constructed and a fusion protein with expected molecular weight was expressed.Specific humoral response was elicited by the recombinant protein in New Zealand rabbits and the antibody titer reached 1:6400.Compared with FTA-ABS test,the indirect ELISA showed a sensitivity and specificity of 92.6%and 98.6%,respectively,in the detection of control and clinical sera.Conclusion The recombinant protein Tp0821 shows excellent immunocompetence,which can be applied to the serological diagnosis of syphilis.