Phenotypic characterization and predictive analysis of p.Asp47Asn LDL receptor mutation associated with Familial Hypercholesterolemia in a Chilean population

BackgroundFamilial hypercholesterolemia (FH) is an inherited disorder mainly caused by mutations in the LDL receptor (LDL-R) and characterized by elevation of low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease.ObjectiveIn this study, we evaluated the clinical phenotype of the p.Asp47Asn, described as an uncertain pathogenic variant, and its effect on the structure of LDL-R and ligand interactions with apolipoproteins.Methods27 children and adolescents with suspected FH diagnosis were recruited from a pediatric endocrinology outpatient clinic. Blood samples were collected after 12 h fasting for lipid profile analysis. DNA sequencing was performed for six FH-related genes by Ion Torrent PGM platform and copy number variation by MLPA. For index cases, a familial cascade screening was done restricted to the same mutation found in the index case. In silico analysis were developed to evaluate the binding capacity of LDL-R to apolipoproteins B100 and E.ResultsLipid profile in children and adolescents demonstrated higher LDL-C levels in p.Asp47Asn carriers compared to the wild type genotype. In silico analysis predicted a reduction in the binding capacity of the ligand-binding modules LA1-2 of p.Asp47Asn LDL-R for ApoB100 and ApoE, which was not produced by local structural changes or folding defects but as a consequence of a decreased apparent affinity for both apolipoproteins.ConclusionThe clinical phenotype and the structural effects of p.Asp47Asn LDL-R mutation suggest that this variant associates to FH.     

High prevalence of polymorphisms of angiotensin-converting enzyme (I/D) and endothelial nitric oxide synthase (Glu298Asp) in patients with systemic sclerosis

PURPOSE: Systemic sclerosis is characterized by progressive microvascular occlusion and fibrosis and by an imbalance in the fibrinolytic system. In vivo and in vitro studies suggest that the renin-angiotensin system partly regulates vascular fibrinolytic balance. Angiotensin II increases the production and secretion of plasminogen activator inhibitor-1, while angiotensin-converting enzyme (ACE) contributes to reduced production of tissue plasminogen activator and endothelial nitric oxide synthesis by bradykinin degradation. The aim of our study was to investigate the effects of ACE insertion/deletion (I/D) and endothelial nitric oxide synthase (eNOS) Glu298Asp (G894-->T) and T-786-->C polymorphisms in patients with systemic sclerosis. SUBJECTS AND METHODS: We studied 73 consecutive patients (47 with limited and 26 with diffuse cutaneous systemic sclerosis) and 112 control subjects. ACE I/D and eNOS polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: The ACE I/D and the eNOS G894-->T polymorphisms were more common in patients than in controls (for the ACE D allele: odds ratio [OR] = 3.4; 95% confidence interval [CI]: 1.5 to 7.9; P = 0.003; for the eNOS T allele: OR = 1.9; 95% CI: 1.0 to 3.4; P = 0.04). There was no association between the eNOS T-786-->C polymorphism and systemic sclerosis. CONCLUSIONS: Our findings of an increased risk of systemic sclerosis in ACE D and eNOS 894T allele carriers suggest that these polymorphisms may contribute to the pathogenesis of the disease.     

Association between Endothelial Nitric Oxide Synthase Glu298Asp Gene Polymorphism and Diabetic Nephropathy Susceptibility

The association between endothelial nitric oxide synthase (eNOS) Glu298Asp gene polymorphism and diabetic nephropathy (DN) risk is still controversial. A meta-analysis was performed to evaluate the association between eNOS Glu298Asp gene polymorphism and DN susceptibility. A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic database. Eight articles were identified for the analysis of association between eNOS Glu298Asp gene polymorphism and DN risk. T allele was associated with DN susceptibility in overall populations, in Asians, and for Caucasians (overall populations, p = 0.005; Asians, p = 0.004; Caucasians, p = 0.002). Furthermore, GG genotype might play a protective role against DN onset for overall populations, Asians, Caucasians, and Africans. However, a link between eNOS Glu298Asp gene polymorphism and DN risk was not found in overall populations, Asians, Caucasians, and Brazil population. In conclusion, T allele might become a significant genetic molecular marker for the onset of DN in overall populations, in Asians, and for Caucasians. However, more studies should be performed in the future.     

滋肾通络方对MCAO大鼠脑组织氨基酸递质含量的影响

目的:观察滋肾通络方对大脑中动脉闭塞MCAO大鼠脑组织氨基酸递质含量的影响.方法:例作MCAO大鼠模型,随机分为假手术组、模型组、中药高剂量组、中药低剂量组和西药组.灌胃20天后,取大鼠脑组织,匀浆,取上清液,用氨基酸分析仪检测各组Asp、Glu、Gly的含量.结果:模型组Asp、Glu、Cly的含量均升高,用药组的Asp、Glu、Gly的含量均降低.且中药组的下降趋势优于西药组.结论:滋肾通络方可降低兴奋性氨基酸的含量,从而对脑缺血损伤具有保护作用.     

静脉用人血丙种球蛋白治疗川崎病36例临床观察

目的 探讨静脉用人血丙种球蛋白治疗川崎病的临床效果。方法 将70例川崎病按治疗方法不同分成两组，治疗组36 例给予阿司匹林和IVIG 联合治疗，对照组34 例单用阿司匹林治疗，比较两组临床症状消退时间。结果 疾病早期（病程7d内）应用丙种球蛋白，患儿在退热、球结膜充血、手足肿胀、颈淋巴结肿大消散与对照组差异显著（P〈0.01），可明显降低冠状动脉病变的发生率。结论 静脉用丙种球蛋白治疗川崎病疗效肯定，值得临床推广和应用。     

Effect of Moisture on the Stability of a Lyophilized Humanized Monoclonal Antibody Formulation

Purpose. To determine the effect of moisture and the role of the glass transition temperature (T_g) on the stability of a high concentration, lyophilized, monoclonal antibody. Methods. A humanized monoclonal antibody was lyophilized in a sucrose/histidine/polysorbate 20 formulation. Residual moistures were from 1 to 8%. T_g values were measured by modulated DSC. Vials were stored at temperatures from 5 to 50°C for 6 or 12 months. Aggregation was monitored by size exclusion chromatography and Asp isomerization by hydrophobic interaction chromatography. Changes in secondary structure were monitored by Fourier transform infrared (FTIR). Results. T_g values varied from 80°C at 1% moisture to 25°C at 8% moisture. There was no cake collapse and were no differences in the secondary structure by FTIR. All formulations were stable at 5°C. High moisture cakes had higher aggregation rates than drier samples if stored above their T_g values. Intermediate moisture vials were more stable to aggregation than dry vials. High moisture samples had increased rates of Asp isomerization at elevated temperatures both above and below their T_g values. Chemical and physical degradation pathways followed Arrhenius kinetics during storage in the glassy state. Only Asp isomerization followed the Arrhenius model above the T_g value. Both chemical and physical stability at T T_g were fitted to Williams-Landel-Ferry (WLF) kinetics. The WLF constants were dependent on the nature of the degradation system and were not characteristic of the solid system. Conclusion. High moisture levels decreased chemical stability of the formulation regardless of whether the protein was in a glassy or rubbery state. In contrast, physical stability was not compromised, and may even be enhanced, by increasing residual moisture if storage is below the T_g value.     

Pharmacogenetics of Naltrexone in Asian Americans: A Randomized Placebo-Controlled Laboratory Study

Recent clinical and laboratory studies have shown that the effects of naltrexone for alcoholism may be moderated by the Asn40Asp single-nucleotide polymorphism (SNP) of the μ-opioid receptor gene (OPRM1). Allele frequencies for this polymorphism, however, have been shown to vary substantially as a function of ethnic background, such that individuals of Asian descent are more likely to carry the minor (Asp40) allele. The objective of this study is to test the naltrexone pharmacogenetic effects of the Asn40Asp SNP in a sample of Asian Americans. This study consists of a double-blinded, randomized, placebo-controlled laboratory trial of naltrexone. Participants (n=35, 10 females; 13 Asn40Asn and 22 Asp40 carriers) were non-treatment-seeking heavy drinkers recruited from the community. After taking naltrexone or placebo, participants completed an intravenous alcohol administration session. The primary outcome measures were subjective intoxication and alcohol craving. Results suggested that Asp40 carriers experienced greater alcohol-induced sedation, subjective intoxication, and lower alcohol craving on naltrexone, as compared to placebo, and to Asn40 homozygotes. There results were maintained when controlling for ALDH2 (rs671) and ADH1B (rs1229984) markers and when examining the three levels of OPRM1 genotype, thereby supporting an OPRM1 gene dose response. These findings provide a much-needed extension of previous studies of naltrexone pharmacogenetics to individuals of Asian descent, an ethnic group more likely to express the minor allele putatively associated with improved biobehavioral and clinical response to this medication. These findings help further delineate the biobehavioral mechanisms of naltrexone and its pharmacogenetics.     

Phosphorylation and function of cardiac myosin binding protein-C in health and disease

During the past 5 years there has been an increasing body of literature describing the roles cardiac myosin binding protein C (cMyBP-C) phosphorylation play in regulating cardiac function and heart failure. cMyBP-C is a sarcomeric thick filament protein that interacts with titin, myosin and actin to regulate sarcomeric assembly, structure and function. Elucidating the function of cMyBP-C is clinically important because mutations in this protein have been linked to cardiomyopathy in more than sixty million people worldwide. One function of cMyBP-C is to regulate cross-bridge formation through dynamic phosphorylation by protein kinase A, protein kinase C and Ca²⁺-calmodulin-activated kinase II, suggesting that cMyBP-C phosphorylation serves as a highly coordinated point of contractile regulation. Moreover, dephosphorylation of cMyBP-C, which accelerates its degradation, has been shown to associate with the development of heart failure in mouse models and in humans. Strikingly, cMyBP-C phosphorylation presents a potential target for therapeutic development as protection against ischemic-reperfusion injury, which has been demonstrated in mouse hearts. Also, emerging evidence suggests that cMyBP-C has the potential to be used as a biomarker for diagnosing myocardial infarction. Although many aspects of cMyBP-C phosphorylation and function remain poorly understood, cMyBP-C and its phosphorylation states have significant promise as a target for therapy and for providing a better understanding of the mechanics of heart function during health and disease. In this review we discuss the most recent findings with respect to cMyBP-C phosphorylation and function and determine potential future directions to better understand the functional role of cMyBP-C and phosphorylation in sarcomeric structure, myocardial contractility and cardioprotection.     

Hydrops Fetalis Associated with Homozygosity for Hb Adana [α59(E8)Gly→Asp (α2)]

We describe cases of hydrops fetalis associated with nondeletional α-thalassemia (α-thal), in three unrelated Indonesian families. The genotypes of the fetuses and their parents were generated by DNA sequencing and by a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP)-based method to rapidly identify mutations detected by sequencing. Two of the fetuses had hydrops fetalis and homozygous α59(E8)Gly→Asp (α2), also known as Hb Adana. The third fetus was also suspected to be homozygous for Hb Adana because both parents were carriers of this mutation. This study shows that homozygosity for Hb Adana is associated with hydrops fetalis in the Indonesian population. We discuss this mutation and its various phenotypes including compound heterozygosity with other α-thal mutations and describe a simple approach to genetic testing that will clarify the risk of hydrops fetalis in the offspring of couples carrying this nondeletional mutation.