猪溶血素突变体的构建及活性评价

目的:构建无溶血活性的猪溶血素突变体,并对制备蛋白进行功能评价。方法:根据猪溶素的晶体结构,采用定点突变分别将其353位脯氨酸突变为丙氨酸、亮氨酸和缬氨酸。重组表达的突变体蛋白采用镍柱亲和层析进行柱上复性后,评价纯化蛋白的溶血活性和免疫原性。结果:获得三种猪溶素突变体,SLY(P353A),SLY(P353L)和SLY(P353V)。溶血试证明SLY(P353V)无溶血活性,蛋白质免疫印迹和动物实验显示SLY(P353V)具有免疫原性。结论:猪溶素突变体SLY(P353V)无溶血活性,有免疫原性。     

Screening for hereditary haemochromatosis

Hereditary haemochromatosis (HH) is a common autosomal recessive disorder of iron overload in Caucasian populations. Clinical manifestations usually occur in individuals homozygous for the C282Y mutation in the HFE gene product and who have developed significant iron loading. Current screening methods can detect affected individuals either prior to or early during disease evolution, enabling early introduction of phlebotomy treatment that can normalise life expectancy. Evaluation of possible iron overload, via measurement of serum transferrin saturation and ferritin level, is the most appropriate initial test for those subjects presenting clinically for evaluation. HFE genotyping, when combined with serum biochemical measurements, defines the presence of likely iron overload and the underlying genetic disorder and is the preferred initial screening modality for families of an affected individual. Definitive proof of iron overload requires measurement of hepatic iron concentration or total iron burden via therapeutic phlebotomy; elevated serum ferritin level alone is not adequate. We now recognise that the natural history of HH is not as discrete as previously believed, because genetic and environmental modifiers of disease penetrance are increasingly identified as influencing the clinical expression of HH. In fact, a minority of C282Y homozygotes develop classical 'iron overload disease', although it has recently emerged that the disorder may predispose to breast and colorectal cancer. Uncertainties as to the true clinical impact of the condition at a population level lead to current recommendations of cascade screening of families of affected patients, case-finding in high-risk groups, such as patients with clinical manifestations consistent with the diagnosis, and a high level of clinical awareness in the community to facilitate early diagnosis. Generalised population screening is not presently recommended.     

Neonatal Fc receptor stimulation induces ubiquitin c-terminal hydrolase-1 overexpression in podocytes through activation of p38 mitogen-activated protein kinase

Ubiquitin c-terminal hydrolase-1 is overexpressed in renal podocytes in some immune complex-mediated glomerulonephritides, an effect closely related to extensive podocyte injury. Neonatal Fc receptor is newly recognized to be present on human renal podocytes. It is presumed that neonatal Fc receptor serves as a sensor for immune stimulation transduction and is involved in the pathogenesis of podocyte injury. In our current study, we found that neonatal Fc receptor was constitutively expressed in normal podocytes and up-regulated by immune stimulation induced by antithymocyte serum. An increase in neonatal Fc receptor expression was observed in human podocytes within diseased glomeruli in 97 cases of various glomerulonephritides. The expression percentage was significantly higher in immune-mediated disease, including membranous nephropathy (46.7%), immunoglobin A nephropathy (66.7%), lupus nephritis (87.5%), and acute proliferative glomerulonephritis (100%), than in normal kidney samples (16.7%) (P < .05), whereas there was no significant difference between minimal-change disease and normal kidney. Further study showed that neonatal Fc receptor up-regulated the expression of ubiquitin c-terminal hydrolase-1 via activation of p38 in podocytes subjected to immune stimulation in vitro. These data suggest that neonatal Fc receptor acts as an immune sensor that evokes an inflammatory response, which may lead to functional and morphological changes in podocytes in glomerulonephritides.     

Cellular uptake and intracellular trafficking of PEG-b-PLA polymeric micelles

Besides as an inert carrier for hydrophobic anticancer agents, polymeric micelles composed of di-block copolymer poly(ethylene glycol)-poly(lactic acid) (PEG-b-PLA) function as biological response modifiers including reversal of multidrug resistance in cancer. However, the uptake mechanisms and the subsequent intracellular trafficking remain to be elucidated. In this paper, we found that the uptake of PEG-b-PLA polymeric micelles incorporating nile red (M-NR) was significantly inhibited by both dynamin inhibitor dynasore and dynamin-2 dominant negative mutant (dynamin-2 K44A). Exogenously expressed caveolin-1 colocalized with M-NR and upregulated M-NR internalization in HepG2 cells expressing low level of endogenous caveolin-1, while caveolin-1 dominant negative mutant (caveolin-1 Y14F) significantly downregulated M-NR internalization in C6 cells expressing high level of endogenous caveolin-1. Exogenously expressed clathrin light chain A (clathrin LCa) did not mainly colocalize with the internalized M-NR and had no effect on M-NR uptake. These results suggested that dynamin- and caveolin-dependent but clathrin-independent endocytosis was involved in M-NR cellular uptake. We further found that M-NR colocalized with lysosome and microtubulin after internalization.     

Surgical removal of an intravascular ultrasonography catheter captured in a stent after percutaneous coronary intervention

A-79-year-old woman underwent percutaneous coronary intervention (PCI) to the right coronary artery (RCA) for effort angina, followed by intravascular ultrasonography (IVUS) to ascertain stent expansion. The IVUS catheter became entangled in the stent and could not be withdrawn from the outside. The patient was transferred to our hospital for its surgical removal. For the emergent surgery, we opened the stent region in the RCA and directly removed the IVUS catheter with the twisted stent. Additional coronary artery bypass grafting (CABG) involving three vessels was performed. She was discharged 42 days after surgery.     

振动排痰机对股骨颈骨折术后并发肺部感染老年患者血气分析指标的影响

目的探讨振动排痰机对股骨颈骨折术后并发肺部感染老年患者血气分析指标的影响。方法将26例股骨颈骨折术后并发肺部感染老年患者,根据不同排痰方法分为振动排痰机组(13例)及人工扣背组(13例)。比较两组患者血气分析指标变化情况的差异。结果人工扣背组患者排痰后除血氧饱和度(SaO2)指标外,其余指标排痰前后比较,差异无统计学意义(均P>0.05)。振动排痰机组患者排痰后SaO2、氧分压(PaO2)、二氧化碳分压(PaCO2)指标均较排痰后有明显改善,排痰前后比较,差异具有统计学意义(均P<0.05)。排痰后两组患者PaO2和PaCO2指标组间比较,差异具有统计学意义(均P<0.05)。结论采用振动排痰机可改善股骨颈骨折术后并发肺部感染老年患者血气分析指标和肺通气,具有良好辅助治疗作用。其操作便利,值得临床应用推广。     

高糖状态下小鼠肾小球足细胞凋亡和组成型光形态建成1蛋白的表达

背景:组成型光形态建成1蛋白与细胞凋亡有关。目的:观察高糖对体外培养的小鼠肾小球足细胞凋亡和组成型光形态建成1蛋白表达的影响。方法:将不同浓度葡萄糖溶液分别加入体外培养的条件永生性小鼠肾小球足细胞株培养液中,培养不同时间后检测肾小球足细胞凋亡指数和死亡指数,以筛选最佳剂量效应葡萄糖浓度。用30mmol/L葡萄糖溶液干预小鼠肾小球足细胞(高糖组),并设立对照组和采用30mmol/L甘露醇干预的甘露醇组。结果与结论:在一定浓度范围内,葡萄糖呈时间和剂量依赖性诱导肾小球足细胞凋亡和死亡(P<0.05),随着葡萄糖浓度的进一步加大,肾小球足细胞死亡指数明显升高,而凋亡指数变化不大。与对照组比较,高糖组凋亡指数显著增加(P<0.05),其COP1 mRNA及蛋白表达水平均明显下降(P<0.05)。结果证实,高糖可诱导肾小球足细胞的凋亡,其机制可能与其下调COP1的表达有关。     

Cryosurgery as primary treatment for localized prostate cancer

Objective  

To present the early results of the use of third-generation cryotherapy as primary treatment for localized prostate cancer in China.