牛津单髁膝关节置换：长期结果

牛津膝置换是使用最广泛的膝关节单髁置换（UKR）。牛津膝在37年前开始应用,拥有一个全匹配的活动衬垫,因而磨损率非常低。牛津膝最主要的使用指征是膝关节前内侧骨关节炎,这种病人至少占所有需要行膝关节置换术患者的50％。由于这一系统的设计特点,传统UKR的反指征,如年龄、活动量、肥胖、髌股关节损害和软骨钙质沉着症等对于牛津膝均不是反指征。与全膝关节置换（TKR）相比,牛津膝提供更快的康复、更好的功能、更大的活动度和更好的术后满意度,发生并发症更少、程度更轻,病残率和死亡率更低。一个持续超过30年的研究显示在90％的病例中,牛津膝为患者终生提供了优或良的临床结果,且不需要翻修。在最近15年,牛津膝通过微创手术入路植入,涉及6000多例使用该入路牛津膝置换的9个研究报道显示,10年生存率约95％。在许多这样的研究中,医生们在拟行膝关节置换的患者中约50％使用了牛津单髁膝置换。     

Genetic Typing of Classical Swine Fever Virus Isolates from China

The E2 genes of 73 classical swine fever virus (CSFV) originated from CSF suspected cases in different regions of China were genetically characterized and compared with reference CSF viruses. All Chinese viruses that characterized were segregated into two major groups and subdivided into four subgroups. Most of isolates (61.6%) belonged to group 2 and were further divided into three subgroups: subgroup 2.1, 2.2 and 2.3. Subgroup 2.1 was the largest subgroup which contained 46.6% of isolates, whiles subgroup 2.3 was the smallest subgroup which contained only one isolate (1.4%). The remaining 38.4% of isolates were classified into subgroup 1.1 within group 1. However, no group 3 and subgroups 1.2 and 1.3 viruses were found in this study. This study has provided epidemiological information useful for assessing the virus origin and establishing a national prevention and control strategy against the disease.     

Development and Application of a Loop‐mediated Isothermal Amplification Assay for Rapid Detection of Borrelia burgdorferi s. l. in Ticks

A loop‐mediated isothermal amplification (LAMP) assay was developed to detect Borrelia burgdorferi s. l. in ticks, which is a pathogen that causes Lyme disease. Cross‐reactions with Chlamydia psittaci, Mycoplasma mycoides subsp. capri and some tick‐borne pathogens were excluded. Analytical sensitivity of LAMP showed its detection limit was from 0.02 to 0.2 pg of DNA in detection of the reference samples at 65°C for 40 min. The performance of LAMP was assessed by testing 110 samples from susceptible tick species and comparing the results with conventional and nested PCR tests previously described. The results demonstrated that LAMP was significantly more sensitive than the conventional PCR (32.7% versus 15.5%, P < 0.05) and slightly more sensitive, although not significantly so, than nested PCR (32.7% versus 26.4%, P > 0.05). The assay was used to analyse a total of 1052 ticks collected from eight provinces in China. The results showed that the infection rates of B. burgdorferi s. l. varied from 12.5% to 88.9% across the different geographical sites. Selected positive samples were subjected to sequencing and sequence analysis for conformation of the accuracy of the assay. Here we report a highly sensitive, specific and easy diagnostic assay based on LAMP technology. These data indicate that LAMP is a useful approach for detecting B. burgdorferi s. l. in field‐collected ticks and has the potential as an alternative tool for the ecological and epidemiological surveillance of Lyme disease.     

Comparative characterization of stem cells from human exfoliated deciduous teeth and dental pulp stem cells

ObjectiveThis study focused on the characterization of stem cells from human exfoliated deciduous teeth (SHED) in comparison with dental pulp stem cells (DPSCs) to certify SHED as a key element in tissue engineering.MethodsIn the present study, SHED and DPSCs were assayed for their cell surface antigens and proliferation by measuring the cell cycles, growth rates, Ki67-positive efficiencies, and colony-forming units (CFUs). The evaluation of multi-differentiation was performed using alizarin red and oil red O and real-time PCR in vitro. The mineralization capability of the cells was examined in vivo by implanting with ceramic bovine bone (CBB) into subcutaneous of immunocompromised mice for 8 weeks. A three-dimensional pellet cultivation system is proposed for SHED and DPSCs to recreate the biological microenvironment that is similar to that of a regenerative milieu.ResultsSHED showed a higher proliferation rate and differentiation capability in comparison with DPSCs in vitro, and the results of the in vivo transplantation suggest that SHED have a higher capability of mineralization than the DPSCs. The mRNA expression levels of inflammatory cytokines, including matrix metalloproteinase-1 (MMP1), tissue inhibitors of metalloproteinase-1 (TIMP1), matrix metalloproteinase-2 (MMP2), tissue inhibitors of metalloproteinase-2 (TIMP2) and interleukin-6 (IL-6) were higher in SHED than that in DPSCs. In addition, the expression levels of Col I and proliferating cell nuclear antigen (PCNA) in SHED sheets were significantly higher than those in DPSCs sheets.ConclusionsThis study systematically demonstrated the differences in the growth and differentiation characteristics between SHED and DPSCs. Consequently, SHED may represent a suitable, accessible and potential alternative source for regenerative medicine and therapeutic applications.     

The optimal dose of recombinant human osteogenic protein-1 enhances differentiation of mouse osteoblast-like cells: an in vitro study

ObjectiveThere is no certain conclusion on the effect of recombinant human Osteogenic Protein-1 (OP-1, BMP-7) on the proliferation of the osteoblast-like cell line, MC3T3-E1. Furthermore, the optimal dose of rhOP-1 on cell differentiation still needs to be elucidated. This investigation aims to delineate the biofunctional characteristics of rhOP-1 in inducing osteoblastogenesis of MC3T3-E1 through in vitro time-course and dose–response studies.DesignMC3T3-E1 cells were cultured for 1, 4, 7 days with the addition of different rhOP-1 concentrations (0, 10, 20, 50, 100, 200, 400 ng/ml), and cell proliferation and cell differentiation were examined.ResultsMC3T3-E1 cell proliferation was stimulated by rhOP-1 in a dose-dependent manner (0–400 ng/ml) on day 1, whereas on day 4 and 7, it was still stimulated at low concentrations (10, 20, 50 ng/ml) but inhibited at high ones (200, 400 ng/ml). The alkaline phosphatase (ALP) activity, osteocalcin (OC) production, collagen deposition and extracellular matrix mineralization were dramatically elevated by rhOP-1 treatment, as a function of culture time and rhOP-1 concentration, and all of them reached a plateau at the concentration of 200 ng/ml. Real-time quantitative RT-PCR results showed Runx2, AKP-2, OC and Nog mRNA expressions increased in a dose- and time-dependent manner, and their expressions were significantly higher at high rhOP-1 concentrations than that of low ones. No significant differences were found between the effects of 200 ng/ml rhOP-1 and 400 ng/ml rhOP-1 on the differentiation of MC3T3-E1 cells, except the expression of Nog mRNA, whose expression level was much higher at 400 ng/ml than that at 200 ng/ml.ConclusionsThese results suggest that cell proliferation of MC3T3-E1 is depended on culture time and rhOP-1 concentration, rhOP-1 could stimulate the differentiation of MC3T3-E1 cells and the optimal concentration could be 200 ng/ml.     

Endovascular recanalisation therapy for prolonged basilar artery occlusion based on clinical-diffusion MRI mismatch

Objectives

Clinical-diffusion magnetic resonance imaging (MRI) mismatch (CDM) in patients with anterior circulation occlusions is an optional method used to select patients for recanalisation outside the 3-h time window. A similar concept has not been reported with posterior circulation occlusions.

Methods

CDM was defined as a Glasgow Coma Scale (GCS) score <8 with DWI lesions not located in the dorsal pons, midbrain or thalamus at the time of admission. Eligible patients were treated with endovascular recanalisation therapy (ERT). The treatment included intra-arterial rt-PA thrombolysis and angioplasty and stenting performed separately or combined. The recanalisation result was assessed by angiography immediately after the treatment according to the trial reports in the Thrombolysis in Myocardial Infarction Criteria (TIMI). The complications and outcome 3 months later were recorded.

Results

Nine patients with a mean age of 66.6 years were included in the study (7 men and 2 women). The median durations of clinical presentation and coma were 31 h (range 25–53 h) and 6 h (range 2–13 h). The median GCS score at admission was 6 (range 4–7). Occlusions were located in the proximal basilar artery (BA) (n = 2) and the middle BA (n = 7). ERT was successful in 8 patients (TIMI 2, n = 2 and TIMI 3, n = 6) but failed in 1 patient because recanalisation was not possible (TIMI 0). No intracranial haemorrhage or dissections occurred during treatment. The recanalised patients recovered consciousness within 9–27 h after treatment. The median GCS score upon discharge was 14 (range 3–15). Three months later, 6 patients had a good outcome (modified Rankin Score (mRS) 0–2), and 2 patients had a moderate outcome (mRS 3). The patient who did not undergo recanalisation died in the rehabilitation hospital 21 days later.

Conclusions

CDM may be a valid method for selecting patients with prolonged basilar artery occlusion (BAO) who are eligible for recanalisation treatment. ERT was feasible for patients with BAO. A good clinical outcome was achieved with successful recanalisation.