Early or delayed operation,which is more optimal for kyphoplasty? A retrospective study on cement leakage during kyphoplasty

PurposeTo retrospectively assess the optimal operating time for kyphoplasty as far as the cement leakage during kyphoplasty is concerned.Materials and methodsOne hundred and six patients with a total of 117 osteoporotic vertebral compression fractures (VCFs) were enrolled in our study. According to the time of kyphoplasty, they were divided into two groups: group 1 (early operation group, who received the operation within 14 days after fracture, n = 46) and group 2 (delayed operation group, who received the operation between 15 and 28 days after fracture, n = 71). Preoperative and postoperative visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores were compared 3 days after surgery within each group and between the two groups. The radiographic outcomes were evaluated by the restoration rate (RR) of the treated vertebrae. The outcome of cement leakage was assessed after surgery using X-ray and computed tomography (CT) scans. Leaks of cement were classified into three types: those via the basivertebral vein (type B), via the segmental vein (type S) and through a cortical defect (type C).ResultsThe mean VAS and ODI scores decreased significantly from pre-surgery to post-surgery in each group, as did the RR (p > 0.05). There was no significant difference postoperatively on VAS and ODI scores (p > 0.05) between the two groups. However, significant differences were observed postoperatively on RR (p = 0.045) and vertebrae with leakage (p = 0.038). In addition, there was a significant difference on leakage site of type C between the two groups (p = 0.032).ConclusionBoth early and delayed operations of kyphoplasty can achieve satisfactory clinical and radiographic outcomes for osteoporotic VCFs. The risk of cement leakage during kyphoplasty will decrease obviously in delayed operation; so delayed operation, perhaps 2 weeks after fracture, is more safe and optimal than early operation as far as cement leakage is concerned, especially for vertebrae with cortical defects. But early operation of kyphoplasty is more effective in vertebral height restoration.     

针灸预处理对大鼠心肌缺血/再灌注后高迁移率族蛋白B1的影响

目的：探讨针灸预处理对大鼠心肌缺血/再灌注（I/R）后的保护作用以及对高迁移率族蛋白B1（HMGB1）表达的影响。方法选择60只Wistar大鼠,按随机数字表法分为假手术组、心肌I/R模型组、针灸预处理组,每组20只。采用结扎冠状动脉左室支左心耳下缘约0.5 cm处阻断血流10 min后再灌注1 h制备I/R损伤模型;假手术组仅穿线不结扎;针灸预处理组于I/R前7 d给予每日1次电针内关穴20 min,连续治疗7 d。采用苏木素-伊红（HE）染色,光镜下观察心肌组织病理学变化,半定量积分法计算3组心肌组织病理学评分;采用酶联免疫吸附试验（ELISA）检测血浆HMGB1、肿瘤坏死因子-α（TNF-α）、心肌肌钙蛋白T（cTnT）的含量,逆转录-聚合酶链反应（RT-PCR）、蛋白质免疫印迹试验（Western Blot）检测心肌组织HMGB1、单核细胞趋化蛋白-1（MCP-1）、TNF-α的mRNA及蛋白表达水平。结果光镜下可见心肌I/R模型组心肌纤维部分断裂,心肌细胞大片状坏死,边界不清,细胞出现浓缩、破裂、溶解、甚至消失,间质水肿并伴大量炎性细胞浸润;针灸预处理组上述表现较心肌I/R模型组明显减轻。与假手术组比较,心肌I/R模型组HMGB1、TNF-α、cTnT含量和组织病理学评分均明显升高〔HMGB1（μg/L）：9.64±1.16比2.15±.031,TNF-α（μg/L）：91±22比19±5, cTnT（μg/L）：1.50±0.35比0.07±0.03,组织病理学评分（分）：2.5±0.3比0.0±0.0,均P＜0.01〕,HMGB1、MCP-1、TNF-αmRNA和蛋白表达均明显升高（HMGB1 mRNA：1.42±0.16比0.02±0.00,MCP-1 mRNA：0.46±0.06比0.01±0.00,TNF-αmRNA：0.75±0.04比0.03±0.00;HMGB1蛋白：1.08±0.01比0.02±0.01, MCP-1蛋白：0.92±0.03比0.40±0.01,TNF-α蛋白：1.10±0.02比0.35±0.01,P＜0.05或P＜0.01）;与心肌I/R模型组比较,针灸预处理组HMGB1（6.58±0.73）、TNF-α（63±19）、cTnT（1.15±0.31）含量均明显降低（均P＜0.01）,HMGB1、MCP-1、TNF-αmRNA和蛋白表达明显降低（mRNA表达分别为0.74±0.12、0.18±0.02、0.10±0.03,蛋白表达分别为0.40±0.01、0.36±0.02、0.50±0.02,均P＜0.05）,组织病理学评分（1.2±1.0）明显降低（P＜0.01）。结论针灸预处理可减轻大鼠心肌I/R损伤,其机制可能与减轻HMGB1介导的晚期炎症反应有关。     

Genetics of osteoporosis

Genetic factors play an important role in regulating bone mineral density and other phenotypes relevant to the pathogenesis of osteoporosis such as ultrasound properties of bone, skeletal geometry, and bone turnover. Progress has been made in identifying quantitative traits for regulation of bone mineral density by linkage studies in man and mouse, but relatively few causal genes have been identified. Dramatic progress has been made in identifying the genes responsible for monogenic bone diseases and it appears that polymorphisms in many of these genes also play a role in regulating bone mineral density in the general population. Advances in knowledge about the genetic basis of osteoporosis and other bone diseases offer the prospect of developing new markers for assessment of fracture risk and the identification of novel molecular targets for the design of new drug treatments for osteoporosis.     

烧伤病区创面感染与医务人员手污染的相关分析

目的了解烧伤病区创面感染病原菌与工作人员手带菌情况,分析病原菌特征,并提出控制对策。方法调查深圳宝安区人民医院烧伤病区2006年-2007年住院烧伤患者,对烧伤创面感染者创面分泌物培养结果和工作人员手带菌情况进行调查分析。结果2006—2007年住院烧伤患者544例,发生烧伤创面感染48例,发病率8．82％。送检创面分泌物标本82份,检出病原菌株52株,其中G^-菌29株（55．77％）,G^＋菌22株（30．77％）,真菌1株（1．92％）。创面培养病原菌以金黄色葡萄球菌和铜绿假单胞菌为主;医务人员未经消毒手表面随机采样187份,检出细菌136株,细菌检出率71．96％,可见手污染带菌比例较高,其中以表皮葡萄球菌、铜绿假单胞菌、大肠埃希菌、金黄色葡萄球菌为主。结论创面感染病原菌与医务人员手污染菌有相关性,说明经医务人员污染手接触传播致烧伤创面感染情况不容忽视,故加强和重视烧伤病区医务人员手卫生监管对降低创面感染的发生有重要意义。     

ALS-associated mutations in TDP-43 increase its stability and promote TDP-43 complexes with FUS/TLS

Dominant mutations in two functionally related DNA/RNA-binding proteins, trans-activating response region (TAR) DNA-binding protein with a molecular mass of 43 KDa (TDP-43) and fused in sarcoma/translocation in liposarcoma (FUS/TLS), cause an inherited form of ALS that is accompanied by nuclear and cytoplasmic aggregates containing TDP-43 or FUS/TLS. Using isogenic cell lines expressing wild-type or ALS-linked TDP-43 mutants and fibroblasts from a human patient, pulse-chase radiolabeling of newly synthesized proteins is used to determine, surprisingly, that ALS-linked TDP-43 mutant polypeptides are more stable than wild-type TDP-43. Tandem-affinity purification and quantitative mass spectrometry are used to identify TDP-43 complexes not only with heterogeneous nuclear ribonucleoproteins family proteins, as expected, but also with components of Drosha microprocessor complexes, consistent with roles for TDP-43 in both mRNA processing and microRNA biogenesis. A fraction of TDP-43 is shown to be complexed with FUS/TLS, an interaction substantially enhanced by TDP-43 mutants. Taken together, abnormal stability of mutant TDP-43 and its enhanced binding to normal FUS/TLS imply a convergence of pathogenic pathways from mutant TDP-43 and FUS/TLS in ALS.     

Role of heteromultimers in the generation of myocardial transient outward K+ currents

Previous studies have demonstrated a role for Kv4 alpha subunits in the generation of the fast transient outward K+ current, I(to,f), in the mammalian myocardium. The experiments here were undertaken to explore the role of homomeric/heteromeric assembly of Kv4.2 and Kv4.3 and of the Kv channel accessory subunit, KChIP2, in the generation of mouse ventricular I(to,f). Western blots reveal that the expression of Kv4.2 parallels the regional heterogeneity in I(to,f) density, whereas Kv4.3 and KChIP2 are uniformly expressed in adult mouse ventricles. Antisense oligodeoxynucleotides (AsODNs) targeted against Kv4.2 or Kv4.3 selectively attenuate I(to,f) in mouse ventricular cells. Adenoviral-mediated coexpression of Kv4.2 and Kv4.3 in HEK-293 cells and in mouse ventricular myocytes produces transient outward K+ currents with properties distinct from those produced on expression of Kv4.2 or Kv4.3 alone, and the gating properties of the heteromeric Kv4.2/Kv4.3 channels in ventricular cells are more similar to native I(to,f) than are the homomeric Kv4.2 or Kv4.3 channels. Biochemical studies reveal that Kv4.2, Kv4.3, and KChIP2 coimmunoprecipitate from adult mouse ventricles. In addition, most of the Kv4.2 and KChIP2 are associated with Kv4.3 in situ. Taken together, these results demonstrate that functional mouse ventricular I(to,f) channels are heteromeric, comprising Kv4.2/Kv4.3 alpha subunits and KChIP2. The results here also suggest that Kv4.2 is the primary determinant of the regional heterogeneity in I(to,f) expression in adult mouse ventricle.     

Network Meta-Analysis of Novel Glucose-Lowering Drugs on Risk of Acute Kidney Injury

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Structural analysis of the dodecameric proteasome activator PafE in Mycobacterium tuberculosis

The human pathogen Mycobacterium tuberculosis (Mtb) requires a proteasome system to cause lethal infections in mice. We recently found that proteasome accessory factor E (PafE, Rv3780) activates proteolysis by the Mtb proteasome independently of adenosine triphosphate (ATP). Moreover, PafE contributes to the heat-shock response and virulence of Mtb. Here, we show that PafE subunits formed four-helix bundles similar to those of the eukaryotic ATP-independent proteasome activator subunits of PA26 and PA28. However, unlike any other known proteasome activator, PafE formed dodecamers with 12-fold symmetry, which required a glycine-XXX-glycine-XXX-glycine motif that is not found in previously described activators. Intriguingly, the truncation of the PafE carboxyl-terminus resulted in the robust binding of PafE rings to native proteasome core particles and substantially increased proteasomal activity, suggesting that the extended carboxyl-terminus of this cofactor confers suboptimal binding to the proteasome core particle. Collectively, our data show that proteasomal activation is not limited to hexameric ATPases in bacteria.Although the ubiquitin proteasome pathway plays essential roles in eukaryotes (reviewed in refs. 1 and 2), most bacterial species do not have proteasome systems and instead degrade proteins using ATP-dependent proteases like ClpP, Lon, and HslUV (reviewed in refs. 3 and 4). However, bacteria of the orders Actinomycetales and Nitrospirales also encode proteasomes that are structurally highly similar to eukaryotic and archaeal proteasomes (reviewed in refs. 5 and 6). Importantly, the human pathogen Mycobacterium tuberculosis (Mtb), an Actinomycete, requires proteasomal function to cause lethal infections in mice (7). Ablation of proteasomal degradation sensitizes bacteria to nitric oxide, an antimicrobial free radical made by macrophages and other cell types, and attenuates bacterial growth in mice (7–9). The potential to target persistent or latent bacteria has made the Mtb proteasome system a prioritized target for the development of antituberculosis drugs (10, 11). Indeed, Mtb-specific proteasome inhibitors have been identified that may provide a promising lead for new drugs to treat tuberculosis (12, 13).There are numerous similarities and differences between eukaryotic and bacterial proteasomes. The 20S proteasome core particle (20S CP), which consists of two seven-membered β-rings between two seven-membered α-rings, is highly conserved structurally between prokaryotes and eukaryotes (14–16). However, the accessory factors that associate with the 20S CPs quickly diverge among the domains of life. Both bacteria and eukaryotes use a covalent small protein modification to mark substrate proteins for degradation; however, the eukaryotic ubiquitin tag is a well-folded protein whereas the Mtb Pup (prokaryotic ubiquitin-like protein) tag is intrinsically disordered (17, 18). Furthermore, degradation of ubiquitylated proteins by eukaryotic 20S CPs largely relies on a complex regulatory particle that caps one or both ends of the 20S CP and includes a heterohexameric ring of adenosine triphosphatases (ATPases) for substrate recognition and unfolding (reviewed in refs. 19 and 20). In contrast, the mycobacterial 20S CP uses a homohexameric ATPase ring called Mpa (mycobacterial proteasome ATPase) for both the recognition and unfolding of pupylated proteins (18, 21, 22).In addition to the ATPase activators, proteolysis by eukaryotic proteasomes can also be stimulated by several ATP-independent factors, such as the 11S activators PA26 and PA28, as well as Blm10 (23–28). We and another group recently discovered that Mtb has an analogous factor encoded by Rv3780 that we call PafE (proteasome accessory factor E; also known as Bpa for bacterial proteasome activator), which stimulates the degradation of small peptides and β-casein in vitro (29, 30). Both studies also showed that a carboxyl (C)-terminal glycine-glutamine-tyrosine-leucine (GQYL) motif is essential for interacting with and activating 20S CPs, and the penultimate tyrosine residue contributes to activation similarly to tyrosines observed in the “HbYX” (hydrophobic-tyrosine-any amino acid) motif in other characterized proteasome activators (reviewed in ref. 28). Our work further showed that PafE promotes the degradation of at least one native Mtb protein substrate, heat-shock protein repressor (HspR), and that an Mtb pafE mutant is sensitive to heat shock and is attenuated for growth in mice (30). Importantly, PafE-mediated degradation does not require pupylation. Thus, there appear to be at least two independent paths for targeting proteins to the mycobacterial proteasome for degradation.Like the eukaryotic 11S proteasome activators, PafE does not require ATP to stimulate proteolysis. However, it was unknown if PafE formed heptameric complexes like PA26 or PA28. In this work, we show that PafE monomers assume a four-helix bundle structure that is similar to that found in 11S activators, but assemble differently into an unprecedented dodecameric ring structure with 12-fold symmetry. We used isothermal titration calorimetry, cryo-electron microscopy (cryo-EM), and X-ray crystallography to analyze interactions between PafE and 20S core particles, and found that PafE binding induces a larger gate-opening change than has been described for other organisms. We also found that PafE has an extended C terminus that limits the ability of PafE to activate proteasomal degradation in vitro and in vivo.     

羊水细胞培养技术的临床应用

目的探索羊水细胞染色体培养改良方法,提高培养、收获成功率,满足临床诊断需要。方法对493例羊水标本进行细胞培养和染色体收获,并对实验细节进行优化,建立标准操作程序。结果羊水培养成功率99.8%（492/493）,发现21-三体6例、18-三体2例、其他异常2例。结论采取严格质量控制;保留换液后的上清,解决因收获失败无法诊断的问题;采取肝素抗凝等,消除母血细胞干扰,可使羊水细胞培养成功。