Virion-bound ICAM-1 and activated LFA-1: a combination of factors conferring resistance to neutralization by sera from human immunodeficiency virus type 1-infected individuals independently of the disease status and phase

The role of the supplementary interaction between virion-bound host ICAM-1 and LFA-1 on target cells in sensitivity to neutralization of human immunodeficiency virus type 1 (HIV-1) is poorly studied. Serum samples from four long-term nonprogressors (LTNPs) and sequential sera from one progressor were used to assess neutralization sensitivity of isogenic ICAM-1-negative and ICAM-1-bearing HIV-1(NL4-3), a prototype of T-cell-line-adapted viruses. We found that virus neutralization sensitivity to the studied sera is not modified by the additional interaction between virally embedded ICAM-1 and LFA-1 under an inactive state. However, expression on the target cell surface of an activated LFA-1 form renders ICAM-1-bearing virus particles, but not viruses devoid of ICAM-1, more refractory to neutralization by sera from three out of four LTNPs and all sequential sera from the person who has experienced a progression of the HIV-1-associated disease. Although no conclusive correlation could be drawn between virus susceptibility to neutralization and the disease status or stages of HIV-1 infection, these findings demonstrate that other nonspecific virus-cell interactions mediated by virion-anchored host proteins and their normal cognate ligands on target cells represent factors that can affect the mechanism of HIV-1 neutralization.     

Functional CD4+T cell subsets defined by expression of CD45RC and NTA260 antigens and age-associated polarization in murine lupus

Using two mAb, one specific to the alternative exon 6-dependentepitope of CD45 molecules(JH6.2) and one a natural thymocytotoxicautoantibody (NTA) with an unknown reactive epitope (NTA260),we subdivided splenic CD4⁺ T cells from 2-month-old BALB/c miceinto five phenotypically distinct subsets. CD45RC⁺NTA260^–(SI) cells were phenotypically analogous to CD4⁺ T cells predominatingin newborn mice and produced a significant amount of IL-2, butnot so IL-4, IL-10 or IFN-_{RC="http://intimm.oxfordjournals.org/math/gamma.gif" ALT="{gamma}" BORDER="0">} when stimulated with immobilizedanti-CD3 mAb in vitro. They appeared to consist mainly of naiveT_hP cells. The CD45RC⁺;NTA260⁺ (S II) subset also produced IL-2,but not other cytokines; however, the IL-2 levels produced weremuch higher than seen with the S I subset, thereby suggestingthe predominance of further maturated T_hP cells. The D45RC^–NTA260⁺(S III) subset mainly produced IL-4, IL-10, IFN-RC="http://intimm.oxfordjournals.org/math/gamma.gif" ALT="{gamma}" BORDER="0"> and less IL-2,and contained memory cells that helped the secondary antibodyresponse to a recall antigen, and hence contained T_h2 and probablya mixture of T_h0 and T_h1 cells. The CD45RC^–NTA260^–(S IV) subset was a poor responder to the immobilized anti-CD3mAb. The CD45RC^brightNTA260^dull(S V) subset consisted of a smallnumber of cells that were phenotypically analogous to activatedCD4⁺ T cells. While an age-associated decrease in the proportionof S I and less markedly in S II and in turn increase in S IIIsubsets of CD4⁺ T cells occurred in normal BALB/c mice, autoimmunedisease-prone (NZBxNZW)F₁ mice showed a marked age-associateddecrease in the proportion of not only S I, II but also IIIsubsets. As aged (NZBxNZW)F₁ mice carry CD4⁺ T helper cellsfor IgG anti-DNA antibody production, such age-associated polarizationto the S IV subset appears to be critical in the pathogeneslsof autoimmune disease in these mice.     

大花红景天对苯血液毒性干预的探讨

目的研究大花红景天(Rhod iola Crenu lata,RC)对苯血液毒性的干预作用。方法用1 600 mg/kg苯对100只成年雌性大鼠灌胃3周复制出苯血液毒性的动物模型后,按白细胞数分为模型对照组,13.5 mg/kg鲨肝醇组,1 000、2 000、4 000 mg/kg RC组进行治疗,每周5 d,连续5周,另设不做处理的正常对照组,每组10只。实验结束时,测定血细胞、骨髓象、骨髓细胞超微结构、骨髓嗜多染红细胞微核率、血清超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量。结果RC治疗苯中毒大鼠5周后,RC可恢复苯引起的白细胞减少,降低骨髓嗜多染红细胞微核率,提高骨髓红细胞系水平(P<0.01),2 000 mg/kg RC组可促进苯中毒大鼠骨髓粒细胞系增生(P<0.01)。但RC对血清SOD活力和MDA含量并无影响。结论RC对苯中毒引起的白细胞下降有一定的治疗作用,但效果并不明显。     

An Efficient Method for Optimizing HPC-FRP Retrofit Systems of Flexural Strengthened One-Way Continuous Slabs Based on ACI 440.2R

An innovative retrofit system consisting of fiber-reinforced polymers (FRP) and high-performance concrete (HPC) considering the difficulty of the accessibility and installation of FRP on the underside of reinforced concrete (RC) slabs was found to be efficient in the flexural strengthening of existing RC slabs. It is important to note that continuous slabs using the FRP-HPC retrofit systems are less effective in exploiting FRP tensile strength and can cause sudden failure once excessively enhanced flexural strength exceeds shear strength. A design method to ensure ductile failure mode was also proposed for strengthened continuous RC slabs in the previous literature. Thus, it is necessary to optimize retrofit systems in terms of mechanical performance aspects to improve the efficiency of retrofitted slabs in serviceability. This study proposes a design method for optimizing the strength of materials and inducing ductile failure of continuous slab retrofitting FRP-HPC systems. The proposed approach demonstrated its effectiveness for strengthening a continuous RC slab with various FRP-HPC retrofit systems through a case study. The results show that the design factored load in the serviceability limit state does not change appreciably from a decrease in carbon fiber-reinforced polymers (CFRP) of 38%; the design factored load decreased only by 9% and the ultimate failure load by 13% while reducing CFRP by 20% and HPC by 25%.     

Time-Dependent Seismic Fragility of Typical Concrete Girder Bridges under Chloride-Induced Corrosion

Recent studies highlighted the importance of the combined effects of prestress loss and corrosion deterioration for concrete girder bridge structures when the effect of damage on the performance level is estimated. The multi-deterioration mechanisms connected with chloride erosion include the cross-sectional area loss of longitudinal bars and stirrups, the reduction in the ductility, the decrease in the strength of steels and the strength loss of concrete in RC columns. For the corroded RC columns and corroded elastomeric bridge bearings, analytical models of the material degradation phenomena were employed for performing the probabilistic seismic performance analysis, which could obtain the system seismic fragility of aging bridges by considering the failure functionality of multiple correlated components (e.g., columns, bearings). The combined effects of prestress loss and cracking were also considered when developing time-dependent system seismic fragility functions. Here, a typical multi-span reinforced concrete girder bridge was used as a case study for studying the time-variant seismic performance. The results revealed the importance of the joint effects of the multi-deterioration mechanisms when modeling the time-dependent seismic fragility of aging bridge systems, as well as the significance of considering the combined effects of prestress loss and cracking.     

Fatigue Life Prediction of CFRP-Strengthened RC Beams with Flexural Crack under Hygrothermal Environments

The durability of reinforced concrete (RC) beams strengthened with carbon fiber-reinforced polymer (CFRP) is a worldwide concern in structural engineering. As an important part of the strengthened beam, the performance of the CFRP–concrete interface under hygrothermal environments is a delicate problem. In this paper, the fatigue behavior of CFRP-strengthened RC beams is analyzed by a theoretical model. In the model, CFRP–concrete interface degradation under hygrothermal environments is involved. Since interface debonding and rebar fracture induced by intermediate cracking are two typical failure modes, the damage models of rebar and the CFRP–concrete interface are established. Based on the theoretical model, the failure mode of CFRP-strengthened RC beams can be predicted, and fatigue life can be determined. The results showed that IC debonding is more likely to occur under hygrothermal environments. The accurate prediction of failure modes is essential for fatigue life prediction.     

Does an additional antirotation U-Blade (RC) lag screw improve treatment of AO/OTA 31 A1-3 fractures with gamma 3 nail?

IntroductionPoor bone quality and unstable fractures increase the cut-out rate in implants with gliding lag screws. The U-Blade (RC) lag screw for the Gamma3^® nail was introduced to provide monoaxial rotational stability of the femoral head and neck fragment. The purpose of this study was to evaluate whether the use of the U-Blade (RC) lag screw is associated with reduced cut-out in patients with OTA/AO 31A1-3 fractures.Material & methodsBetween 2009 and 2014, 751 patients with OTA/AO 31A1-3 fractures were treated with a Gamma3^® nail at our institution. Out of this sample 199 patients were treated with U-blade (RC) lag screws. A total of 135 patients (117 female, 18 male) with standard lag screw (treatment group A) were matched equally regarding age (±4 years) sex, fracture type and location to 135 patients with U-blade (RC) lag screw (treatment group B). Within a mean follow up of 9.2 months (range 6–18 months) we assessed the cut-out rate, the calTAD, lag screw migration, the Parker's mobility score and the Parker’s ratio at postoperatively, six and 12 months following surgery. Furthermore we recorded all complications, ASA-Score, hospital stay and duration of surgery retrospectively.ResultsThe most common fracture among group B with a cut-out of the lag screw were AO/OTA 2.3 and 3.2 fractures whereas in group A cut-out was most commonly seen in AO/OTA 2.1, 2.2 and 2.3 fractures, there was no significant reduction of the cut-out rate in group B 2.2% (n = 3) compared to group A 3.7% (n = 5). The duration of surgery was significantly shorter in group A (p < 0.05). There was no significant difference in lag screw placement, the Parker’s ratio and mobilization.ConclusionIn our study the U-Blade (RC) lag screw did not reduce the cut-out in treatment of OTA/AO 31A1-3 fractures at all. Considering the longer duration of surgery and the higher costs of the U-Blade (RC) lag screw, our results do not justify its use. However, further prospective randomized studies will be necessary.     

改良小骨窗与大骨瓣开颅血肿清除术治疗高血压脑出血的临床对比研究

目的 研究小骨窗开颅术与大骨瓣开颅术对高血压脑出血的治疗效果.方法 对2007至2011年间收治的80例高血压脑出血患者随机分为实验组和对照组各40例,实验组使用小骨窗开颅术,对照组使用大骨瓣开颅血肿清除术进行治疗,对两组患者治疗效果及并发症情况进行观察和比较.结果 对照组患者痊愈3例,显著改善22例,有效率62.5％；实验组痊愈5例,显著改善30例,有效率87.5％,实验组显著高于对照组(P＜0.05).实验组患者肺部感染发生率30％,显著低于对照组的52.5％(P＜ 0.05),其余并发症两组比较差异无显著性(P＞0.05).结论小骨窗开颅术比大骨瓣开颅血肿清除术有更好的治疗效果而操作更简便,术后并发症更少,是一种理想的手术方案.