Leukemic-like membrane properties acquired by B lymphocytes when depleted of 185,000-dalton macromolecular insoluble cold globulin

Human peripheral blood lymphocytes can be phenotypically identified by the presence of one or both of two proteins, 225,000-dalton macromolecular insoluble cold globulin (225-MICG) and 185,000-dalton MICG (185-MICG). T cells synthesize and insert into their plasma membrane 225-MICG, null cells 185-MICG, and B cells both 225 and 185- MICG. In contrast, the monoclonal B cells of chronic lymphocytic leukemia are characterized by the presence of 225-MICG and the absence of 185-MICG. We have recently found it possible to chemically deplete 185-MICG from viable normal B cells by treating them with diisopropylfluorophosphate (DFP), thus making normal B cells phenotypically resemble leukemic cells. In the present report we determined whether certain peculiar properties of these leukemic cells would be associated with the normal B cells chemically depleted of 185- MICG. In normal B cells, SIg diffuses in the lipid bilayer to form clusters and caps under appropriate conditions, while in chronic lymphocytic leukemia (CLL) cells this does not occur. Normal B cells depleted of 185-MICG fail to undergo capping of SIg or surface MICG under appropriate conditions. Both DFP-treated B cells and CLL cells tend to rupture when smeared on a glass slide. Both CLL cells and DFP- treated B cells fail to secrete 225-MICG after it has been synthesized intracellularly. The relationship of these findings to the mechanisms of secretion and capping are discussed.     

筛选心肌缺血再灌注大鼠差异表达基因

目的：利用抑制性消减杂交技术，筛选出大鼠心肌缺血再灌注的差异表达基因，以期通过基因线索探讨其损伤机制。方法：实验于2006—03／10在中山大学中山医学院完成。①实验分组：Sprague-Dawley雄性大鼠40只，随机分为手术组，对照组，每组20只。②实验干预：手术组结扎左冠状动脉，心电图出现急性心肌梗死改变90min后，去除结扎线，再灌注60min，建立心肌缺血再灌注大鼠模型。对照组仅穿线不结扎，余同手术组。③取缺血区心肌，提取Total RNA，构建cDNA文库，利用抑制性消减杂交技术筛选差异表达基因，测序，登录Genbank寻找同源性基因。结果：共获得124个阳性结果，56个为高表达基因，68个为低表达基因，其中发现5个新的cDNA片段。其中能量代谢、物质运输、信号转导相关差异表达基因分别占所有差异表达基因的39．25％，15．89％，15．89％，并且主要变化为下调。结论：抑制性消减杂交技术是一种高效的筛选差异基因的方法。心肌缺血再灌注后基因变化涉及多种功能的基因，以能量代谢、物质运输、信号转导相关基因下调明显。     

体外培养的脐静脉内皮细胞中过氧化物酶体增殖物激活受体γ及内皮素1基因表达与罗格列酮的影响

目的:观察过氧化物酶体增殖物激活受体γ(PPARγ)的高选择性强效激动剂罗格列酮对体外培养的正常人脐静脉内皮细胞中PPARγ基因及内皮素1基因转录及翻译水平的影响,探讨两者间的相互关系及在抗颈动脉粥样硬化中的作用。方法:实验于2007-03在武汉市第一医院中心实验室完成。①培养人脐静脉内皮细胞,采用MTT法得出罗格列酮浓度为5μmol/L时对细胞活性影响最小。②实验分为2组,罗格列酮干预组采用5μmol/L罗格列酮干预人脐静脉内皮细胞24h,同时设空白对照组。③通过Quantitative real-time PCR定量检测2组PPARγ与内皮素1的mRNA表达;Western blot检测PPARγ蛋白与内皮素1前体蛋白水平;然后对PPARγ及内皮素1的RT-PCR及Westernblot结果进行相关性分析。结果:①罗格列酮干预组人脐静脉内皮细胞PPARγmRNA和蛋白质水平高于空白对照组(P<0.001),内皮素1 mRNA及内皮素1前体蛋白水平低于空白对照组(P<0.001)。②PPARγ与内皮素1 mRNA及蛋白表达量的变化之间均有一定的相关性(r=0.914,P=0.011;r=0.999,P=0.028)。结论:罗格列酮可以通过增加PPARγ的表达量在转录和翻译水平抑制内皮素1及其前体在人脐静脉内皮细胞的基因表达,共同在动脉粥样硬化形成过程中发挥作用。     

Structure of the 26S proteasome from Schizosaccharomyces pombe at subnanometer resolution

The structure of the 26S proteasome from Schizosaccharomyces pombe has been determined to a resolution of 9.1 Å by cryoelectron microscopy and single particle analysis. In addition, chemical cross-linking in conjunction with mass spectrometry has been used to identify numerous residue pairs in close proximity to each other, providing an array of spatial restraints. Taken together these data clarify the topology of the AAA-ATPase module in the 19S regulatory particle and its spatial relationship to the α-ring of the 20S core particle. Image classification and variance analysis reveal a belt of high “activity” surrounding the AAA-ATPase module which is tentatively assigned to the reversible association of proteasome interacting proteins and the conformational heterogeneity among the particles. An integrated model is presented which sheds light on the early steps of protein degradation by the 26S complex.     

Effect of an innovative model of complexity care on family caregiver experience: Qualitative study in family practice

ObjectiveTo investigate the experiences of family caregivers who participated in an innovative model of interprofessional team–based care specifically designed for elderly patients with complex care needs.DesignQualitative study.SettingLarge academic family practice in Toronto, Ont.ParticipantsFamily caregivers of elderly patients who had attended the IMPACT (Interprofessional Model of Practice for Aging and Complex Treatments) clinic (N = 13).MethodsIndividual semistructured interviews, which were conducted face-to-face, audiorecorded, transcribed verbatim, and analyzed using the constant comparative method.Main findingsFamily caregivers who attended the IMPACT clinic believed it enhanced caregiver experience and capacity. Caregivers experienced increased validation and engagement with the treatment team. Feelings of isolation were reduced, resulting in increased confidence and greater feelings of empowerment in their caregiver role.ConclusionWhile the needs and value of caregivers are increasingly acknowledged, health care teams continue to struggle with how to relate to and engage with family caregivers—how best to support them and work with them in the context of their family members’ care. Interprofessional teams who adopt the IMPACT model—providing synchronous, real-time interventions that include the caregiver—can facilitate increased caregiver capacity, confidence, and empowerment.     

肠缺血再灌注大鼠肺及血液白细胞介素6、白细胞介素8和肿瘤坏死因子α变化与辅酶Q10的干预

目的:观察大鼠肠缺血再灌注时肺及血液白细胞介素6、白细胞介素8和肿瘤坏死因子α的变化以及辅酶Q10的影响。方法:实验于2006-12/2007-02在滨州医学院药理学实验室和免疫学实验室(山东省重点学科三级实验室)完成。①实验分组:清洁级健康Wistar大鼠30只,体质量290～390g,随机数字表法分为假手术组、肠缺血再灌注组,辅酶Q10处理组(缺血再灌注 辅酶Q10),每组10只。②实验方法:建立肠缺血再灌注模型,钝性分离肠系膜上动脉的根部,假手术组不作其他处理;肠缺血再灌注组再灌前30min时经股静脉注入生理盐水10mL/kg;辅酶Q10处理组再灌前30min时经股静脉注入辅酶Q1010mg/kg。③实验评估:酶联免疫吸附法(ELISA)检测各组动物血液、肺组织匀浆及肺泡灌洗液中的白细胞介素6、白细胞介素8和肿瘤坏死因子α含量;光镜下观察肺组织形态学变化。肺泡灌洗液沉渣进行白细胞计数和分类。结果:纳入大鼠30只,均进入结果分析。①肺组织形态学变化:假手术组肺组织无病理改变;肠缺血再灌注组肺间质明显水肿,中性粒细胞浸润,有少量的出血和纤维蛋白渗出;辅酶Q10处理组肺间质轻度水肿,少量的中性粒细胞。②肺泡灌洗液白细胞计数组间无显著性差异,多形核细胞分类肠缺血再灌注组明显高于假手术组(P<0.05),而辅酶Q10处理组与其他两组间差异无显著性意义(P>0.05)。③各组动物血液、肺组织匀浆及肺泡灌洗液中的白细胞介素6、白细胞介素8和肿瘤坏死因子α含量:与假手术组比较,肠缺血再灌注组血液、肺组织匀浆及肺泡灌洗液中白细胞介素6、白细胞介素8和肿瘤坏死因子α显著升高(P<0.05或P<0.01)。与肠缺血再灌注组比较,辅酶Q10处理组血液、肺组织匀浆和肺泡灌洗液中白细胞介素6含量显著降低(P<0.05);白细胞介素8和肿瘤坏死因子α含量在血液中显著降低(P<0.05);而在肺组织匀浆中含量未见显著降低(P>0.05);在肺泡灌洗液中含量亦未见显著降低(P>0.05)。结论:辅酶Q10可能通过抑制白细胞介素6、白细胞介素8和肿瘤坏死因子α炎性因子的释放,对大鼠肠缺血再灌后肺损伤有一定的保护作用。     

山茱萸化学成分的研究

从山茱萸(Cornus officinalis Sieb.et Zucc.)的果实中分得一新的双环烯醚萜甙化合物,命名为山茱萸新甙(cornuside)。通过波谱分析(IR,MS,¹HNMR和¹³CNMR)和理化常数测定,确定了它的结构。     

Clinical isolates of Staphylococcus aureus have osteolytic surface proteins and a proportion of the population have antibodies that block this activity: is this of prognostic significance?

Staphylococcus aureus is directly implicated in the bone destruction associated with infected orthopaedic implants and bacterial arthritis. The Oxford (laboratory) strain of this organism has surface-associated proteins (SAPs) which have potent osteolytic activity. In this study, we have examined the osteolytic activity of SAPs from clinical isolates and also investigated the role of the humoral immune response to such proteins. Nine patients with infected orthopaedic prostheses or infective arthritis, and six volunteers not suffering from overt S. aureus infection, were examined. The sera from 5/9 patients and 4/6 volunteers were able to neutralize the osteolytic activity of the SAPs. The SAPs were extracted from four clinical isolates and were found to have osteolytic activity, but with a wide range of efficacies and potencies. All four patients from whom the clinical isolates were obtained had serum IgG antibodies to the surface proteins from their autologous isolates as determined by ELISA. In conclusion, clinical isolates of S. aureus contain osteolytic SAPs which may be responsible for bone destruction. Apparently disease-free individuals and patients have antibodies able to block this activity. However, since the capacity of patients' sera to neutralize the activity of the SAPs derived from their own S. aureus isolate was not investigated, it is unclear whether these findings are of prognostic value.      

Enhanced co-stimulatory ability of synovial fluid accessory cells in rheumatoid arthritis

We have established in vitro assays that allow the examination of co- stimulatory function of rheumatoid arthritis (RA) antigen-presenting cells (APC). Synovial fluid (SF) and peripheral blood (PB) APC co- stimulatory ability was compared in the activation of peptide-specific human T-cell clones. T-cell receptor (TCR) stimulation by peptide or anti-CD3 antibody allowed the direct comparison of SF and PB APC co- stimulatory activity, separately from their ability to process antigen. SF APC from 15 RA patients consistently enhanced T-cell proliferation when compared to their PB counterparts. Moreover, increasing the numbers of PB APC present resulted in only a minor increase in T-cell proliferation, failing to achieve levels stimulated by SF APC. We propose that the enhanced co-stimulatory function of synovial APC may be a significant factor in the persistence of local immune responses in RA.