Repeated short periods of regional myocardial ischemia: effect on local function and high energy phosphate levels

Summary The effect of recurrent periods of ischemia on the myocardium was investigated in 15 open-chest dogs. Ischemia was produced by 3 minutes of proximal occlusion of the left anterior descending coronary artery. Each occlusion was followed by reperfusion of 3 minutes duration. Forty occlusions with a total of 120 minutes of ischemia were performed, and regional function (sonomicrometry) as well as high energy phosphates (needle biopsies) were determined at the end of the 5th, 20th, and 40th period of ischemia and reperfusion. The first periods of ischemia had a cumulative effect both on regional postischemic function (44% and 59% respectively of preischemic control after 20 occlusions) and on the ATP content, but with increasing number of occlusions the additive effects became smaller (ATP reduction/mol/gww/per occlusion). The ATP breakdown per occlusion was diminished with increasing number of periods of ischemia, and no significant adenosine was measured in the ischemic myocardium. Higher than normal postischemic creatine phosphate levels (9.1 mol/g w w at the 40th reperfusion vs. 6.7 mol/gw w control) indicated a functioning oxidative phosphorylation in the presence of an ATP utilization problem at the sarcomere level, because indicators of the cellular energy level (energy charge, free energy change of ATP hydrolysis) quickly normalized during reperfusion. Stunned myocardium is therefore not a problem of energy supply but rather of energy utilization. Reduced ATP utilization and regional dysfunction are the expressions of the same cellular defect which resides either in the ATP-splitting contractile apparatus or in the electromechanical coupling. Contractile dysfunction during reperfusion protects the heart against subsequent periods of ischemia because ATP turnover is reduced.Parts of the results were presented at the 57th Sessions of the American Heart Association, Miami, Florida/U.S.A. 1984     

Chronic Intake of Energy Drinks and Their Sugar Free Substitution Similarly Promotes Metabolic Syndrome

Energy drinks containing significant quantities of caffeine, taurine and sugar are increasingly consumed, particularly by adolescents and young adults. The putative effects of chronic ingestion of either standard energy drink, Mother^TM (ED), or its sugar-free formulation (sfED) on metabolic syndrome were determined in wild-type C57BL/6J mice, in comparison to a soft drink, Coca-Cola (SD), a Western-styled diet enriched in saturated fatty acids (SFA), and a combination of SFA + ED. Following 13 weeks of intervention, mice treated with ED were hyperglycaemic and hypertriglyceridaemic, indicating higher triglyceride glucose index, which was similar to the mice maintained on SD. Surprisingly, the mice maintained on sfED also showed signs of insulin resistance with hyperglycaemia, hypertriglyceridaemia, and greater triglyceride glucose index, comparable to the ED group mice. In addition, the ED mice had greater adiposity primarily due to the increase in white adipose tissue, although the body weight was comparable to the control mice receiving only water. The mice maintained on SFA diet exhibited significantly greater weight gain, body fat, cholesterol and insulin, whilst blood glucose and triglyceride concentrations remained comparable to the control mice. Collectively, these data suggest that the consumption of both standard and sugar-free forms of energy drinks induces metabolic syndrome, particularly insulin resistance.     

用腰椎X—线片半定量诊断骨质疏松的研究

目的验证JOA X-线骨质疏松诊断标准的可靠性.方法47名女性病人(年龄65.3±7.2岁)行腰椎常规X-线检查和第三腰椎正、侧位DEXA骨密度测量.用t检验验证X-线骨质疏松等级间骨密度的差异性,用Spearman相关性分析法检验X-线骨质疏松等级与骨密度值的相关性.结果X-线骨质疏松等级间骨密度具有显著性差异(P＜0.01),X-线骨质疏松等级与第三腰椎侧位骨密度值之间相关性最高(r=0.714).结论通过腰椎X-线片按照JOA标准划分骨质疏松等级,可以作为粗略检查腰椎骨质疏松的方法.     

自发性高血压大鼠左室不同部位心肌纤维化程度的改变: 病理变化与心肌密度改变的对比观察

目的：探讨自发性高血压大鼠（SHR）左室室间隔、前壁、后壁及侧壁 心肌纤维化的动态变化,以及心脏超声显像结合计算机分析检测心肌密度这一方法的可靠性。方法：应用病理及生化检查,检测SHR左室室间隔、间壁、后壁及侧壁心肌纤维化的病变程度;通过心脏超声显像并结合计算机分析,检测大鼠的心肌密度的变化。结果：14周时,代表心肌纤维化水平的参数羟脯氨酸浓度（HC）在SHR室间隔、前壁及后壁即已增高,以室间隔最为明显,而左室侧壁虽有增高趋势,但未达到显著性水平;24周时各部位均明显增加,但各部位之间的差异明显减少。在14周时,代表血管周围纤维化水平的参数血管周围胶原面积（PVCA）在左室各部位较对照组均显著增高,24周时增高更为明显,但各部位之间无显著性差异。而代表间质纤维化水平的参数胶原容积分数（CVF）在14周时只有室间隔显著增高,其余各部位无明显变化;24周时各部位均有显著增高,但仍以室间隔增高最为明显。心肌灰度均值在14周时各部位均较对照组显著增高,各部位之间比较,室间隔最高,侧壁最低,二者之间有显著性差别。24周时各部位均较14周显著增高,但各部位之间差别变小。在室间隔,灰度离散度在14及24周均未出现显著性改变,而其他部位则在14周时增高,24周时趋于正常。结论：在高血压发病过程中,心肌纤维化尤其是间质纤维化的变化程度是不均衡的,以室间隔程度最重,左室侧壁最轻;应用心脏超声显像并结合计算机分析测定心肌密度,可客观地反应心肌纤维化的程度。     

Design and psychometric testing of a new patient-reported outcome measure for ankle treatment

BackgroundSeveral outcome scores are used to assess the outcome of ankle surgery, but many are not validated and there is currently no ‘gold-standard’. Consequently, there is demand to develop a new ‘gold-standard’ score to assess ankle surgery. The study aim was to review existing scores to develop and validate a new patient-reported outcome measure (PROM) to assess the outcome of operative ankle surgery.MethodsThe questionnaire items covered three areas: pain, symptoms and activity. The scale was reviewed by a patient group, resulting in the Oswestry Ankle score (Os-Ankle). The Os-Ankle was validated using a cohort of 206 patients at both pre-operative and post-operative stages of ankle surgery. Patients provided two other outcome scores, the scores currently used at our centre: the Manchester-Oxford Foot Questionnaire (MOxFQ) and the Veterans Rand-12 (VR-12). Factor analysis and Rasch were determined to assess the psychometric testing and design of the Os-Ankle score. A follow up paper assesses the validity of the Os-Ankle against two existing scores.ResultsResults of the factor and Rasch analysis suggested that 12-items should be removed. The remaining 18-items fitted the Rasch model well, suggesting good internal consistency.ConclusionA new ankle PROM, the Os-Ankle, was successfully developed and demonstrated good psychometric testing. The Os-Ankle evaluates pain, symptoms and activities and results in a single score. The Os-Ankle has been validated in our follow up paper, and is ready to be implemented by ankle clinicians to monitor clinical outcomes. With the publication of two back to back papers, it will allow for further engage with other clinicians and other centres.Level of evidenceLevel II, prospective comparative study.     

人体胆结石高能震波碎石的动物实验

目的　研究人体 3种胆结石在一定能量下 ,冲击次数和能量的关系 ,确定不损伤胆囊和小肠内膜的能量安全阈值 .方法　犬胆囊和小肠内放入固醇石、混合石和色素石 ,在不同的输出电压下 ,放电碎石 .结果　固醇石、混合石和色素石破碎所需的能量不同 ,在同样电压下 ,固醇石所需的次数最少 ,混合石次之 ,色素石最多 ;病理检查表明 ,在电压 <15 k V时 ,胆囊和小肠粘膜处 ,细胞膜轻度充血 ,出现小出血点 .当电压 >15 k V后 ,粘膜有脱落 ,膜下组织水肿 .结论　电压具有依赖性 ;该仪器临床应用的冲击电压应小于 15 k V     

医学重复观测数据裂区方差分析的假定条件的检验

目的 重复观测数据存在自相关性常导致一元方差分皙误用,探讨一元方差分析两个假定条件的检验。方法 通过标准正交对比变换克服数据间的自相关性,应用似然比统计量进行假定条件的检验。结果 给出了重复观测数据一元方差分析的假定条件检验方法,并用软件REP得以实现。结论 只有满足假定条件,才可以保证重复观测资料单变量方差分析的有产性。     

Lipoic (thioctic) acid increases brain energy availability and skeletal muscle performance as shown by in vivo31P-MRS in a patient with mitochondrial cytopathy

A woman affected by chronic progressive external ophthalmoplegia and muscle mitochondrial DNA deletion was studied by phosphorus magnetic resonance spectroscopy (³¹P-MRS) prior to and after 1 and 7 months of treatment with oral lipoic acid. Before treatment a decreased phosphocreatine (PCr) content was found in the occipital lobes, accompanied by normal inorganic phosphate (Pi) level and cytosolic pH. Based on these findings, we found a high cytosolic adenosine diphosphate concentration [ADP] and high relative rate of energy metabolism together with a low phosphorylation potential. Muscle MRS showed an abnormal work-energy cost transfer function and a low rate of PCr recovery during the post-exercise period. All of these findings indicated a deficit of mitochondrial function in both brain and muscle. Treatment with 600 mg lipoic acid daily for 1 month resulted in a 55% increase of brain [PCr], 72% increase of phosphorylation potential, and a decrease of calculated [ADP] and rate of energy metabolism. After 7 months of treatment MRS data and mitochondrial function had improved further. Treatment with lipoate also led to a 64% increase in the initial slope of the work-energy cost transfer function in the working calf muscle and worsened the rate of PCr resynthesis during recovery. The patient reported subjective improvement of general conditions and muscle performance after therapy. Our results indicate that treatment with lipoate caused a relevant increase in levels of energy available in brain and skeletal muscle during exercise.     

急性胰腺炎时大鼠肝脏能量代谢变化的实验研究

目的　研究急性胰腺炎时大鼠肝脏能量代谢变化规律。方法　将大鼠分成 2组 ,对照组及急性胰腺炎组 ,比较各组肝组织内能荷及ATP的含量。结果　术后 1～ 12hATP及能荷变化不大 ,2 4h后ATP及能荷水平均显著下降 (P <0 0 0 1)。结论　急性胰腺炎时肝脏功能明显受损 ,揭示临床治疗胰腺炎时应加强对肝脏功能的维护。