高血压病血压昼夜节律与心肌缺血的关系

目的 探讨高血压病患者血压昼夜节律改变与心肌缺血之间的关系及临床意义。方法对90例高血压病患者,根据动态心电图上有无心肌缺血(MI)分为MI组(40例)和无MI组(50例),并与20例健康体检者进行对照,观察3组的动态血压变化,同时分析血压昼夜节律正常组和异常组的心肌缺血的发生情况。结果 高血压病伴有MI的患者中,除dSBP、24hDBPL、dSBPL、dDBPL与无MI组比较无统计学差异外,其余各项动态血压指标均明显高于无MI组(P<0.01);高血压病血压昼夜节律异常组发生MI者明显高于血压昼夜节律正常组(P<0.05)。结论 高血压病患者中伴有血压昼夜节律异常者更易导致心肌缺血的发生。对高血压病患者的治疗,除积极控制血压外,还应注意检测和逆转异常的昼夜血压节律,对减少心肌缺血的发生和靶器官损害具有重要意义。     

核因子-κB活化参与Ox-LDL诱导人肾小球系膜细胞表达单核细胞趋化蛋白-1(英文)

目的：研究核因子-κB(NF-κB)在氧化低密度脂蛋白(Ox-LDL)诱导的体外培养的人肾小球系膜细胞表达单核/巨噬细胞趋化蛋白-1(MCP-1)中的作用。方法： 采用凝胶迁移率变动分析检测NF-κB的DNA结合活性变化，以免疫组化观测细胞内REL P65的核转位，用细胞ELISA法检测细胞内MCP-1及IκBα蛋白含量变化。结果： 不同浓度(10、25、50、100 mg/L)Ox-LDL刺激肾小球系膜细胞均可引起细胞NF-κB的DNA结合活性增强，50 mg/L Ox-LDL活化MCs效果最明显(8.50±1.14，P＜0.01 vs control； P＜0.05 vs 10, 25和100 mg/L Ox-LDL)。Ox-LDL刺激MCs 30-240 min均可以活化NF-κB，60 min时相点活性最强(11.0±2.11，P＜0.01 vs control； P＜0.05 vs 30 min or 240 min)。以50 mg/L Ox-LDL刺激MCs 1 h后，细胞内IκBα蛋白水平最低(0.050±0.006，n=5,P＜0.01 vs control)，作用24 h MCP-1表达水平最高(0.331±0.016， n=5,P＜0.01 vs control)。NF-κB活化的同时伴有REL P65核转位。上述效应可被NF-κB特异性抑制剂吡咯二硫氨基甲酸酯(PDTC)所抑制。结论： Ox-LDL刺激人肾小球系膜细胞产生MCP-1是由NF-κB调控，NF-κB参与了脂质肾损害的发病过程。     

利用噬菌体肽库技术获得与人Fas结合的多肽基序

目的　利用噬菌体随机肽库技术获得与人Fas胞外区结合的多肽及其多肽基序 ,观察多肽基序的生物学功能。方法　以人Fas胞外区与IgGFc段的融合蛋白Fas .Fc为筛选配基 ,筛选噬菌体随机九肽库 ;微量淘洗与ELISA相结合鉴定阳性克隆 ,DNA测序和分析。化学合成多肽进行竞争性ELISA以及细胞增殖抑制实验。结果　经过 4轮亲和筛选 ,微量淘洗鉴定 ,获得 4 2个阳性克隆 ;固定ELISA实验显示筛选到的噬菌体短肽能与Fas .Fc特异性结合 ,并呈剂量依赖关系 ;随机选取 13个阳性克隆进行DNA测序 ,其序列及出现几率分别为 :PRKARVDTS(2 / 13)、YKKKSLQVQ (2 / 13)、YKKKSMLQA(2 / 13)、SRKKYDQYA(4/ 13)、YARKIKPTA(2 / 13)和ARKKTEGAG(1/ 13)。经多重序列分析 ,获得多肽基序 : R/KKK A。在ELISA和竞争性ELISA实验中 ,化学合成多肽EGEFYKKKSM LQADPAK (P3)可抑制Fas与抗人Fas单抗Apo 1的结合 ,且呈剂量效应关系 ;P3不能抑制Fas与FasL的结合。细胞增殖实验表明 ,多肽可抑制Jurkat细胞增殖 ,且随多肽剂量的增加而加强。多肽与单抗Apo 1联合作用对Jurkat细胞增殖的影响与单独使用P3没有明显差别。结论　通过噬菌体随机肽库技术获得与Fas结合的多肽及其多肽基序 ,它们可能模拟了抗Fas抗体Apo 1对Fas的结合位点 ,为基于Fas凋     

含辛伐他汀药物血清对兔血管平滑肌细胞增殖的直接作用及意义

目的 :探讨辛伐他汀对体外培养兔血管平滑肌细胞增殖的影响及意义。方法 :16只雄性新西兰兔随机分为血清对照组和三个不同剂量的辛伐他汀亚组 (每日分别给予辛伐他汀 5mg/kg、10mg/kg、15mg/kg) ,7天后采血并混合每组 4只兔血 ,无菌分离制备三亚组的辛伐他汀含药血清。采用内皮素 1(ET 1)刺激正常喂饲原代培养兔主动脉血管平滑肌细胞的方法 ,建立血管平滑肌细胞增殖模型。采用MTT及3H TdR法检测各组辛伐他汀含药血清对血管平滑肌细胞增殖的作用。结果 :与不含药的正常对照组相比 ,不同亚组辛伐他汀含药血清呈剂量依赖性抑制血管平滑肌细胞增殖 (P <0 .0 1～0 .0 5 )。结论 :兔口服辛伐他汀后的血清具有抑制血管平滑肌细胞增殖的作用     

与大劣按蚊先天免疫相关丝氨酸蛋白酶的克隆及分析

目的克隆及分析与先天免疫相关的大劣按蚊差异基因。方法利用抑制性消减杂交 （ suppression subtractive hybridization, SSH）方法克隆大劣按蚊差异基因，并对与先天免疫相关的差异基因（文中命名为T6基因）进行生物信息学分析及半定量实验，分析约氏疟原虫感染前后其转录的变化，探讨它与按蚊抗疟原虫感染的先天免疫反应的关系。结果目前克隆的差异基因包含以下几类：①与先天免疫相关的酶类；②与能量代谢有关的酶：③与信号传递和调节有关的因子。对与先天免疫相关的分子进行的半定量实验表明，大劣按蚊T6基因的转录与感染疟原虫相关。结论本研究成功地克隆了与先天免疫相关的大劣按蚊差异基因，进一步的实验分析提示该基因可能与按蚊抗约氏疟原虫感染的黑化反应相关。     

Combination of Quantitative Computed Tomography and Blood Biochemistry for Evaluating the Relationship Between Nutrition and Bone Mineral Density in Patients on Maintenance Hemodialysis

PurposeTo investigate the effect of nutritional factors on bone mineral density (BMD) using quantitative computed tomography combined with blood biochemistry in patients on maintenance hemodialysis (MHD).MethodsSixty patients on MHD were divided into osteopenia (n = 20) and nonosteopenia (n = 40) groups. BMD, fat, and muscle mass were measured by quantitative computed tomography. The calcification of coronary artery and hilar lymph node and computed tomography attenuation values of the liver and spleen were also analyzed. Differences between the two groups were compared, and the risk factors for osteopenia were analyzed by logistic regression analysis.ResultsPatients in the osteopenia group had lower albumin levels than those in the nonosteopenia group (37.84 ± 3.00 vs 42.03 ± 4.05 g/L; P < .001). Logistic regression showed that patients with lower albumin levels had a higher risk of osteopenia (odds ratio, 1.462; 95% confidence interval, 1.313–1.801; P = .003). BMD was negatively correlated with fat mass (r = ?0.365, P = .004) and positively correlated with the ratio of muscle mass to fat mass (r = 0.431, P = .001). There was no significant difference in the rate of calcification of coronary artery or hilar lymph nodes between the two groups. Computed tomography values of the liver and spleen were positively correlated with the duration of dialysis (r = 0.55, P = .001; r = 0.42, P < .001, respectively).ConclusionLow albumin levels are associated with an increased risk of osteopenia in patients on MHD. Abdominal fat is a risk factor for reduction in BMD in MHD patients, and the ratio of abdominal muscle mass to fat mass is a protective factor for BMD.     

Evaluation of high protein intake to improve clinical outcome and nutritional status for patients with burns: a systematic review

Background and aimPatients with severe burns undergo a local and systemic response to the injury. As part of this response the patient becomes hypermetabolic. Current guidelines advise high protein intakes to counteract the catabolic response to burns, but this appears to be based on minimal experimental evidence. Hence the aim of this review was to examine the evidence for improvements in nutritional status and clinical outcome with the administration of high protein intakes for patients with burns.MethodsEight databases were searched for clinical trials with burn patients receiving two or more levels of protein intake at or above the level recommended for healthy individuals (0.75 g/kg/d) and presenting results for at least one of the following pre-defined outcomes: nitrogen balance, length of stay, weight change, survival, physical therapy index, protein fractional synthetic rate, immunological measurements, bacteraemic days, systemic antibiotic days and net protein synthesis.ResultsSix studies were included, 4 of which were randomized trials. All had major methodological limitations, in particular none was blinded. There was too much heterogeneity in study design, patient characteristics and the timing and magnitude of the interventions to justify formal meta-analysis. There was no reliable evidence of improvement in nitrogen balance, but there was some evidence of increased weight gain on higher protein diets. One small study reported an increase in survival and significant improvements in infection rates and some indicators of immune function in children. Length of stay was not significantly improved. There was weak evidence of an improvement in muscle strength and endurance but no significant increase in protein synthesis in muscle or skin, or net protein synthesis in the whole body.ConclusionThere is currently only very weak evidence to justify administering high protein diets to patients following burns.     

Adoption of rescue colloid during burn resuscitation decreases fluid administered and restores end-organ perfusion

IntroductionTraditionally, lactated Ringer’s solution (LR) has been utilized for the resuscitation of thermally injured patients via the Parkland or Brooke formulas. Both of these formulas include colloid supplementation after 24 h of resuscitation. Recently, the addition of albumin within the initial resuscitation has been reported to decrease fluid creep and hourly fluids given. Our institution has previously advocated for a crystalloid-driven resuscitation. Given reports of improved outcomes with albumin, we pragmatically adjusted these practices and present our findings for doing so.MethodsOur burn registry, consisting of prospectively collected patient data, was queried for those at least 18 years of age who, between July 2017 and December 2018, sustained a thermal injury and completed a formal resuscitation (24 h). At the attending physician’s discretion, rescue colloid was administered using 25% albumin for those failing to respond to traditional resuscitation (patients with sustained urine output of <0.5 mL/kg over 2–3 h, or unstable vital signs and ongoing fluid administration). We compared the total volume of the crystalloid-only and rescue colloid resuscitation fluids given to patients. We also examined the in/out fluid balances during resuscitation. Statistical analysis was performed using Stata software.ResultsA total of 91 patients with thermal injuries were included: the median age was 40 (IQR 31–57), 73% were male, and 30 patients received rescue albumin. The percentage of total body surface area burned (%TBSA) was greater in those who received rescue albumin (40.3% vs. 34%; p = 0.047). Despite a higher %TBSA in the albumin group, the total LR given during resuscitation was not significantly different between groups (15,914.43 mL vs. 11,828.71 mL; p = 0.129) even when normalized for TBSA and weight (ml LR/kg/%TBSA: 4.31 vs. 3.66; p = 0.129. The average in/out fluid ratio for the rescue group was higher than for the crystalloid group (0.83 ± 0.05 vs. 0.59 ± 0.11; p = 0.06) and returned to normal after colloid administration.ConclusionRescue albumin administration decreases the amount of fluid administered per %TBSA during resuscitation, and also increases end organ function as evidenced by increased urinary output. These effects occurred in patients who sustained larger burns and failed to respond to traditional crystalloid resuscitation. Our findings led us to modify our current protocol and a related prospective study of clinical outcomes.