白藜芦醇对一次性力竭游泳大鼠肝脏组织保护作用的量效关系

目的:观察白藜芦醇对一次性力竭游泳大鼠肝脏组织的作用及发挥作用的最佳口服剂量。方法:实验于2006-05/07在成都体育学院运动医学系动物实验室完成。①实验分组:选取雄性SD大鼠70只,随机分为7组,每组10只,分别为安静对照组,运动对照组,运动 15mg/kg白藜芦醇组,运动 50mg/kg白藜芦醇组,运动 100mg/kg白藜芦醇组,运动 200mg/kg白藜芦醇组,运动 300mg/kg白藜芦醇组。②实验干预:不同剂量白藜芦醇组每天灌胃15,50,100,200,300mg/kg白藜芦醇,安静对照组和运动对照组分别灌胃相同体积的溶媒(二甲亚砜 生理盐水),连续5周。末次给予实验用样品1h后,各运动组每只鼠尾跟部负荷3%体质量铅皮,置于水深50cm、水温(31±1)℃游泳槽中游泳。游泳力竭后即刻,股动脉取血并迅速取出肝组织。③指标检测:赖氏比色法测定血清中谷丙转氨酶活性;邻苯三酚自氧化法测定肝组织超氧化物歧化酶活性;硫代巴比妥酸法测定肝组织丙二醛含量。结果:纳入动物70只,均进入结果分析。①血清谷丙转氨酶活性和肝组织中丙二醛含量:运动对照组显著高于安静对照组,不同剂量白藜芦醇组低于运动对照组(P<0.05或P<0.01)。运动 100,200,300mg/kg白藜芦醇组低于运动 15,50mg/kg白藜芦醇组[谷丙转氨酶活性:(972.36±121.86),(944.36±105.35),(888.34±88.68),(1773.52±89.35),(1377.78±27.01)nkat/L,P<0.01;丙二醛含量:(7.90±2.56),(7.69±3.69),(7.13±2.62),(19.90±2.21),(12.16±1.78)μmol/g,P<0.05]。100,200,300mg/kg白藜芦醇组间差异无显著性。②肝脏组织中超氧化物歧化酶活性:运动对照组显著低于安静对照组,不同剂量白藜芦醇组高于运动对照组(P<0.05或P<0.01)。运动 100,200,300mg/kg白藜芦醇组高于15,50mg/kg白藜芦醇组[(2325.80±163.37),(2379.14±121.86),(2447.16±89.18),(1096.05±120.19),(1514.64±28.17)μkat/g,P<0.01]。结论:①白藜芦醇对力竭性运动大鼠肝脏组织具有保护作用。②100,200,300mg/kg白藜芦醇对肝脏组织发挥保护作用效果优于15,50mg/kg,建议使用100mg/kg白藜芦醇就能达到理想效果。     

Structural requirements of platelet chemokines for neutrophil activation

Using recombinantly expressed proteins and synthetic peptides, we examined the structural/functional features of the platelet chemokines, neutrophil-activating peptide-2 (NAP-2) and platelet factor 4 (PF4); that were important in their activation of neutrophils. Previous studies with the chemokine interleukin-8 (IL-8) had shown that the N- terminal region preceding the first cysteine residue was critical in defining neutrophil-activating properties. We examined whether NAP-2 and PF4 had similar structural requirements. In the Ale-glu-leu-arg (AELR) N-terminus of NAP-2, substitution of E or R abolished Ca2+ mobilization and elastase secretion. Unlike the parent molecule PF4, AELR/PF4, the hybrid formed by replacing the N-terminal sequence of PF4 before the first cysteine residue with the homologous sequence of NAP- 2, stimulated Ca2+ mobilization and elastase secretion. Furthermore, the effect of amino acid substitutions in the ELR motif differed from those seen with NAP-2 in that conserved substitutions of E or R in NAP- 2 abolished activity, but only reduced neutrophil activation in the hybrid. These studies show that just as with IL-8, the N-termini of NAP- 2 and PF4 are critical for high-level neutrophil-activating function. Desensitization studies provided information on receptor binding. NAP- 2, which binds almost exclusively to the type 2 IL-8 receptor (IL-8R), did not desensitize neutrophils to activation by IL-8 because IL-8 could bind to and activate via both type 1 and 2 IL-8R. AELR/PF4 appears to bind to both types of receptors because it desensitized neutrophils to NAP-2 activation; but was not desensitized by NAP-2, and because it desensitized to and was desensitized by IL-8. Thus, although NAP-2 and AELR/PF4 share approximately 60% amino acid homology, they have different receptor affinities. Studies were performed to define the role of the C-termini of these platelet chemokines in receptor binding. Heparin and a monoclonal antibody specific for the heparin- binding domain of PF4 both inhibited Ca2+ mobilization and elastase release, further suggesting that the C-terminus of these chemokines is important in receptor binding. Synthetic NAP-2(51-70) failed to mobilize Ca2+, whereas PF4(47-70) and PF4(58-70) induced Ca2+ mobilization and secretion of elastase at high concentrations. Pertussis toxin inhibited neutrophil activation by 40% to 50%, establishing a role for G-protein-coupled receptors such as the IL-8Rs in activation by the PF4 C-terminal peptides.(ABSTRACT TRUNCATED AT 400 WORDS)     

A humanised tissue‐engineered bone model allows species‐specific breast cancer‐related bone metastasis in vivo

Bone metastases frequently occur in the advanced stages of breast cancer. At this stage, the disease is deemed incurable. To date, the mechanisms of breast cancer‐related metastasis to bone are poorly understood. This may be attributed to the lack of appropriate animal models to investigate the complex cancer cell–bone interactions. In this study, two established tissue‐engineered bone constructs (TEBCs) were applied to a breast cancer‐related metastasis model. A cylindrical medical‐grade polycaprolactone‐tricalcium phosphate scaffold produced by fused deposition modelling (scaffold 1) was compared with a tubular calcium phosphate‐coated polycaprolactone scaffold fabricated by solution electrospinning (scaffold 2) for their potential to generate ectopic humanised bone in NOD/SCID mice. While scaffold 1 was found not suitable to generate a sufficient amount of ectopic bone tissue due to poor ectopic integration, scaffold 2 showed excellent integration into the host tissue, leading to bone formation. To mimic breast cancer cell colonisation to the bone, MDA‐MB‐231, SUM1315, and MDA‐MB‐231BO breast cancer cells were cultured in polyethylene glycol‐based hydrogels and implanted adjacent to the TEBCs. Histological analysis indicated that the breast cancer cells induced an osteoclastic reaction in the TEBCs, demonstrating analogies to breast cancer‐related bone metastasis seen in patients.     

The effectiveness of a treatment protocol for male lower urinary tract symptoms in general practice: a practical randomised controlled trial

BACKGROUND: Randomised controlled trials have shown the efficacy of several treatment modalities for lower urinary tract symptoms (LUTS) in selected populations. The effectiveness in daily practice has hardly been investigated, especially in primary care and is dependent on choices between all possible treatment options and best investigated in a comprehensive study, including all treatment modalities (watchful waiting, alpha-blockers, 5-alpha-reductase inhibitors, and surgery). AIM: Assessment of the effectiveness of a comprehensive treatment protocol for LUTS in primary care. DESIGN OF STUDY: Randomised controlled trial. SETTING: Fourteen general practices in the Netherlands. METHOD: Intervention: treatment protocol based on a formalised expert opinion. Control condition: usual care. Study population: 208 subjects with moderate to severe LUTS (IPSS > or =8, median = 13). OUTCOME MEASURES: symptom severity (IPSS [International Prostate Symptom Score]), bother score (Dan-PSS [Danish Prostate Symptom Score]), and maximum urinary flow (Q(max)); incidence of acute urinary retention and urinary tract infections. RESULTS: In the intervention group markedly more subjects used an alpha-blocker at end of follow-up than in the usual care group (24% versus 6%). No significant differences were found between intervention and control group in IPSS, Q(max) or Dan-PSS. CONCLUSION: alpha-blockers and watchful waiting are the most frequent treatment modalities for LUTS in primary care. Our study showed no evidence that a protocol using well-defined indications for all possible treatment modalities based on a formalised expert opinion procedure has added value. Based on our results, we cannot recommend a broadening of the indication for alpha-blockers, which, however, seems to be the current trend.     

Minimal important differences in the Migraine-Specific Quality of Life Questionnaire (MSQ) version 2.1

To propose minimal important differences (MID) for the Migraine-Specific Quality of Life Questionnaire version 2.1 (MSQ v2.1). To our knowledge (to date), no published MID values exist for the MSQ v2.1 in any population. Analyses were performed on data from two pivotal clinical trials of topiramate for migraine prevention ( n  = 916), as well as from the QualityMetric National Headache Survey ( n  = 1016). Analyses included both distribution- and anchor-based MID techniques as well as group- and individual-level MID values. Group-level anchor-based MID values ranged from 3.2 [Role Restrictive domain (RR)] to 7.5 [Emotional Functioning domain (EF)], setting the minimum level of appropriate MID (which can also aid with power analysis). Individual-level distribution-based MID values resulted in highly similar estimates from two large databases: median MID of 8.5 for RR, 9.2 for Role Preventive (RP) and 12.0 for EF. Finally, individual-level anchor-based MID values ranged from 5.0 (RR and RP domains) to 10.6 (EF). For group-level purposes of calculating power for future studies, an MID of 3.2, 4.6 and 7.5 for RR, RP and EF is recommended. For within-group analyses for analysing clinical trial efficacy of each patient's change with responder analyses, 5 points is necessary for RR. For RP and EF, ranges are recommended: 5.0 to 7.9 for RP and 8.0 to 10.6 for EF. These latter two domains tend to have more error in the MID, and thus a sensitivity analysis with both ends of the range should be used to confirm significant differences in responder analyses.     

Is phenytoin contraindicated in patients receiving cranial irradiation ?

Three recent publications have reported the development of erythema multiforme and Stevens-Johnson syndrome in patients receiving cranial irradiation and sodium phenytoin. Some authors have recommended that patients receiving whole brain radiation therapy and who have had seizures should not be prescribed phenytoin but an alternative anticonvulsant. This article reviews the current literature pertaining to the development of this potentially lethal complication in patients receiving whole brain radiation and phenytoin, with reference to the single recorded case of Stevens-Johnson syndrome in a patient receiving cranial irradiation and phenytoin in Auckland, New Zealand. While the clinical picture in the 16 patients reported in the literature and the current case report differed from the classical form of erythema multiforme, a similar pattern of presentation and outcome appeared in all patients reviewed, suggesting that the combination of phenytoin, cranial irradiation and the gradual reduction of concomitant steroids seem to lead to the development of erythema multiforme and/or Stevens-Johnson syndrome. The data presented, although sparse, suggest that phenytoin should not be prescribed in patients receiving cranial irradiation.