Creatine has no beneficial effect on skeletal muscle energy metabolism in patients with single mitochondrial DNA deletions: a placebo-controlled, double-blind 31P-MRS crossover study

The purpose of our randomized, double-blind, placebo-controlled crossover study in 15 patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) because of single large-scale mitochondrial (mt) DNA deletions was to determine whether oral creatine (Cr) monohydrate can improve skeletal muscle energy metabolism in vivo. Each treatment phase with Cr in a dosage of 150 mg/kg body weight/day or placebo lasted 6 weeks. The effect of Cr was estimated by phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS), clinical and laboratory tests. (31)P-MRS analysis prior to treatment showed clear evidence of severe mitochondrial dysfunction. However, there were no relevant changes in (31)P-MRS parameters under Cr. In particular, phosphocreatine (PCr)/ATP at rest did not increase, and there was no facilitation of post-exercise PCr recovery. Clinical scores and laboratory tests did not alter significantly under Cr, which was tolerated without major side-effects in all patients. Cr supplementation did not improve skeletal muscle oxidative phosphorylation in our series of patients. However, one explanation for our negative findings may be the short study duration or the limited number of patients included.     

Triterpenoid saponins, new metalloprotease snake venom inhibitors isolated from Pentaclethra macroloba.

We report here the antiproteolytic and antihemorrhagic properties of triterpenoid saponin inhibitors, named macrolobin-A and B, from Pentaclethra macroloba, against Bothrops snake venoms. The inhibitors were able to neutralize the hemorrhagic, fibrin(ogen)olytic, and proteolytic activities of class P-I and P-III metalloproteases isolated from B. neuwiedi and B. jararacussu venoms. Clotting and fibrinogenolytic activities induced by snake venoms and isolated thrombin-like enzymes were partially inhibited. Furthermore, the potential use of these inhibitors to complement antivenom therapy as an alternative treatment and/or used as molecular models for development of new therapeutical agents in the treatment of snake bite envenomations needs to be evaluated in future studies.     

Development of an animal model for neuroleptic malignant syndrome: heat-exposed rabbits with haloperidol and atropine administration exhibit increased muscle activity, hyperthermia, and high serum creatine phosphokinase level

The neuroleptic malignant syndrome (NMS) is a life-threatening complication of neuroleptic treatment. To elucidate the pathogenesis of NMS, an animal model has been developed. Experimental rabbits treated with haloperidol (1 mg/kg) by intramuscular injection, were studied for the diagnostic symptoms of increased muscle rigidity, elevated body temperature, and high serum creatine phosphokinase (CPK) level. Administration of haloperidol (1 mg/kg) and atropine (0.4 mg/kg), and exposure to high ambient temperature (35°C) induced a significant increase in electromyographic activity with muscle rigidity similar to that observed in patients with NMS. Such rabbits also showed elevated body temperature and serum CPK value. In addition to the similarity of the signs and symptoms, all parameters measured (muscle rigidity, body temperature, and serum CPK level) were normalized by dantrolene treatment. The effectiveness of dantrolene in the experimental animal partially confirms the validity of this animal model for NMS. This experimental animal model for NMS may be useful to elucidate the pathogenesis of NMS.     

槲皮素磷酸酯钾对实验性心肌梗塞的影响

iv10～20mg/kg(木解)皮素磷酸酯钾使兔急性心肌梗塞范围明显缩小,ST段明显降低,并能对抗冠脉结扎后引起的血清CPK含量增加及心律失常,这些作用与普萘洛尔相似。但iv40mg/kg后作用不明显。     

血尿酸对急性心肌梗死预后的影响

目的 探讨血尿酸水平对急性心肌梗死(AMI)预后的影响.方法 对198例急性心肌梗死患者的血尿酸水平及其肌酸激酶同工酶(CK-MB)峰值,梗死后心绞痛、心律失常、心源性休克、心力衰竭的发生率和病死率的相关关系进行分析比较.结果 198例中正常血尿酸133例,高血尿酸65例.高血尿酸组CK-MB峰值较高,梗死后心绞痛、心律失常、心力衰竭的发生率和病死率均高于正常血尿酸组(P＜0.01或P＜0.05).结论 高血尿酸与AMI预后不良有关.     

火药爆炸复合烧伤大鼠血浆CK-MB与心肌MDA变化

目的 探讨烟花火药爆炸复合烧伤大鼠血浆肌酸激酶心肌同工酶(CK—MB)与心肌丙二醛(MDA)含量的变化。方法 Wistar大鼠128只，随机分为正常对照组(n=8)、烧伤组(n=40)、爆炸伤组(n=40)和复合伤组(n=40)，分别致伤形成大鼠20％体表面积Ⅲ度烧伤、火药爆炸伤和两者复合伤。动态观察大鼠伤后1、3、6、12、24h血浆CK—MB，心肌MDA含量并进行相关分析。结果 复合伤组较单因素致伤组大鼠血浆CK—MB升高明显，心肌组织MDA含量呈类似变化，CK—MB与MDA有相关性。结论 烟花火药爆炸复合烧伤对大鼠心肌的损害较单纯烧伤或爆炸伤更为严重，提示烧伤和爆炸伤有协同致伤作用，氧自由基代谢紊乱参与烟花火药爆炸复合烧伤后心肌的损伤。     

A novel compound heterozygous dysferlin mutation in Miyoshi myopathy siblings responding to dantrolene

Miyoshi myopathy (MM) is an autosomal recessive distal muscular dystrophy characterized by mutations of the dysferlin gene. Although several pairs of homozygous/heterozygous mutations have been reported, few effective treatments of MM are available. We had observed the decreased serum creatine kinase (CK) before and after administration of dantrolene in the elder brother and the increased serum CK before and after discontinuance of the drug on suspicion of drug-induced hepatopathy in the younger sister. We report a novel pair of heterozygous mutations in the 3'-splicing site of exon 26 and the translation site of exon 28 of the dysferlin gene in two siblings, and effective treatment of their MM with dantrolene.     

Metabolite changes with age measured by proton magnetic resonance spectroscopy in normal subjects

Abstract  To determine whether there are metabolite changes in the left medial temporal and frontal lobes with aging, we performed proton magnetic resonance spectroscopy in 36 normal subjects. The N-acetylaspartate/creatine-phosphocreatine ratio in the medial temporal lobe tended to be decreased in subjects over 60 years of age. The ratio decrease in the frontal lobe related to aging was lower than that in the medial temporal lobe. There were no significant differences in the metabolite ratios between males and females. These findings suggest that structures in the medial temporal lobe may be more susceptible to neuronal dysfunction associated with aging than those in the frontal lobe.     

肉苁蓉总苷对阿霉素所致小鼠心肌毒性的保护作用

目的：探讨肉苁蓉总苷（GCs)对阿霉素（Dox)所致小鼠心肌损害的保护作用及其机制。方法：选用NIH小鼠一次腹腔注射Dox(17.5mg/kg)造成急性心肌损伤模型，测定心肌超氧化物歧化酶（SOD）活性；硒－谷胱苷肽过氧化物酶（Se-GSH-Px)活性；丙二醛（MDA）含量及血清肌酸磷酸激酶（CPK）活性。电镜检查心肌细胞超微结构的改变。结果：腹腔注射Dox 48h后可致小鼠心肌明显损害，心肌SOD及Se-GSH-Px活性下降，MDA含量升高，血清中CPK的活性增强，同时出现心肌组织超微结构的损伤。GCs(62.5、125.0、250.0mg/kg）能增加心肌SOD、Se-GSH-Px活性，降低MDA含量，减少CPK释放，减轻心肌超微结构的损伤。结论：肉苁蓉总苷对阿霉素所致心肌损害有一定的保护作用，其机制可能与其保护心肌SOD及Se-GSH-Px活性及其清除自由基，防止脂质过氧化有关。