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11.
Morrot A; Strickland DK; Higuchi M de L; Reis M; Pedrosa R; Scharfstein J 《International immunology》1997,9(6):825-834
Chagas' disease patients (CDP) develop both humoral and cellular immune
responses against the major cysteine proteinase (cruzipain) from
Trypanosoma cruzi. Here we demonstrate that complexes formed by cruzipain
and alpha 2-macroglobulin (alpha 2M) are efficiently internalized by human
monocytes, and that this process results in enhanced presentation of
cruzipain peptides to CD4+ T cells from CDP. Purified or serum alpha 2M
binds to polymorphic cruzipains, but only a fraction of the proteinases
become covalently linked. Once bound to alpha 2M, fluorescein-labeled
cruzipain (FITC-cruzipain) or [125I]cruzipain were more efficiently
internalized by normal peripheral blood mononuclear cells (PBMC) or
monocytes; this effect was abolished by (I) pre-treating the cells with
receptor-associated protein (rRAP), a known antagonist the of alpha 2M
receptor (alpha 2MR/LRP), and (II) inactivating [125I]cruzipain's active
site prior to the reaction with alpha 2M, indicating that the exposure of
receptor binding sites on alpha 2M complexes required bait region cleavage.
We then sought to determine if the alpha 2MR/LRP-dependent uptake of alpha
2M:cruzipain by monocytes resulted in increased CD4+ T cell responses of
PBMC-CDP (n = 13). These effects were only revealed after depletion of
CD19+ B lymphocytes from PBMC-CDP; the threshold of T cell stimulation was
far lower in cultures stimulated with alpha 2M:cruzipain, as compared to
antigen alone. Myocardial specimens from CDP with chronic myocardiopathy
(three necropsies) were analyzed by immunohistochemistry with mAb
anti-cruzipain or anti-alpha 2MR/LRP (CD81+). Extracellular depots of
cruzipain were localized amidst inflammatory mononuclear infiltrates, part
of which contained CD91+ macrophage-like cells. Ongoing studies should
clarify if T. cruzi cysteinyl proteinases play a role in the pathogenesis
of Chagas' heart disease.
相似文献
12.
13.
目的测试骶骨螺钉经上终板固定技术的生物力学性能,并与经前皮质固定技术比较。方法取17具新鲜成年男性骶骨标本,两侧分别采用螺钉经上终板固定和经前皮质固定技术。经前皮质固定的螺钉指向前内侧,平行于终板;经上终板固定的螺钉指向前内侧,矢状面上向头侧成30°~35°角,钉尖对向S1上终板的前部。植入螺钉时测定最大扭矩;通过模拟生理应力进行疲劳试验,测定固定刚度变化和拔出力。结果经上终板固定组螺钉最大扭矩为(3.18±0.49)Nm,经前皮质固定组为(1.98±0.76)Nm, 差异有非常显著性(P< 0.01),经上终板固定组比经前皮质固定组高60.6%; 经上终板固定组拔出力为(1457±276)N,经前皮质固定组为(1122±364)N, 差异有显著性(P< 0.05),经上终板固定组比经前皮质固定组高29.9%;在循环负载过程中,两组刚度在负载早期(前5000个循环)均明显下降,然后趋于平稳,经上终板固定组的最后刚度高于经前皮质固定组(P< 0.05)。两组中螺钉的最大扭矩与拔出力均有显著相关性,相关系数分别为0.94和0.95(P< 0.01)。结论骶骨螺钉经上终板固定技术与经前皮质固定技术相比有一定的力学优越性。 相似文献
14.
15.
目的探讨蜂胶对糖尿病伤口愈合的作用及其机制。方法采用荧光电泳法,检测不同葡萄糖浓度(5、25mmol/L)和不同蜂胶浓度(10、50、100、200μg/ml)处理的体外培养的人成纤维细胞及单核巨噬细胞系的基质金属蛋白酶MMP-9蛋白的表达。结果高浓度葡萄糖(25mmol/L)状态下,MMP-9表达增加,但与低浓度(5mmol/L)比较,差异无统计学意义。蜂胶可显著降低MMP-9的表达,并呈剂量依赖性(P〈.05)。结论高糖能增加单核巨噬细胞系及成纤维细胞MMP-9的表达,可能会影响糖尿病患者伤口的愈合。蜂胶可抑制这些细胞MMP-9的表达,有益于细胞基质的积聚,从而有益于糖尿病患者伤口的愈合。 相似文献
16.
DK Bilku AR Dennison TC Hall MS Metcalfe G Garcea 《Annals of the Royal College of Surgeons of England》2014,96(1):15-22
INTRODUCTION
Surgical stress in the presence of fasting worsens the catabolic state, causes insulin resistance and may delay recovery. Carbohydrate rich drinks given preoperatively may ameliorate these deleterious effects. A systematic review was undertaken to analyse the effect of preoperative carbohydrate loading on insulin resistance, gastric emptying, gastric acidity, patient wellbeing, immunity and nutrition following surgery.METHODS
All studies identified through PubMed until September 2011 were included. References were cross-checked to ensure capture of cited pertinent articles.RESULTS
Overall, 17 randomised controlled trials with a total of 1,445 patients who met the inclusion criteria were identified. Preoperative carbohydrate drinks significantly improved insulin resistance and indices of patient comfort following surgery, especially hunger, thirst, malaise, anxiety and nausea. No definite conclusions could be made regarding preservation of muscle mass. Following ingestion of carbohydrate drinks, no adverse events such as apparent or proven aspiration during or after surgery were reported.CONCLUSIONS
Administration of oral carbohydrate drinks before surgery is probably safe and may have a positive influence on a wide range of perioperative markers of clinical outcome. Further studies are required to determine its cost effectiveness. 相似文献17.
18.
Background: General anaesthesia (GA) for cardiac magnetic resonance imaging (MRI) in patients with congenital heart disease (CHD) is challenging for the anaesthesiologist. 相似文献
19.
Muscular sufficiency, serum protein, enzymes and bioenergetic studies (31-phosphorus magnetic resonance spectroscopy) in chronic malnutrition 总被引:2,自引:0,他引:2
Muscle sufficiency was significantly lower in 1336 children with chronic malnutrition of moderate to severe degree. Eighteen children with a chronic moderate degree of malnutrition and 8 well-nourished, age-matched controls were selected for biochemical and 31-phosphorus magnetic resonance spectroscopy (31 -P MRS) studies. The results showed that: (a) serum total protein, albumin, iron, calcium and inorganic phosphate were similar in both groups; (b) serum enzyme levels were significantly increased in the malnourished group; (c) 31-P MRS showed significantly higher means for total ATP, β-ATP, a-ATP and inorganic phosphate for the malnourished compared to the control group. In chronic malnutrition, proteins are maintained by degradation in muscle resulting in release of amino acids and enzymes. 31-P MRS studies showing increases in total ATP, β-ATP and inorganic phosphate and a decrease in phosphocreatine suggest that ATP is maintained at the cost of phosphocreatine. 相似文献
20.