Comparison of inhaled nitric oxide with aerosolized prostacyclin or analogues for the postoperative management of pulmonary hypertension: a systematic review and meta-analysis

Abstract

Background: This study aims to compare the effectiveness of inhaled prostacyclin or its analoguesversus nitric oxide (NO) in treating pulmonary hypertension (PH) after cardiac or pulmonary surgery remains unclear.

Methods: PubMed, Cochrane, and Embase databases were searched for literature published prior to December 2019 using the following keywords: inhaled, nitric oxide, prostacyclin, iloprost, treprostinil, epoprostenol, Tyvaso, flolan, and pulmonary hypertension. Randomized controlled trials and multiple-armed prospective studies that evaluated inhaled NO versus prostacyclin (or analogues) in patients for perioperative and/or postoperative PH after either cardiac or pulmonary surgery were included. Retrospective studies, reviews, letters, comments, editorials, and case reports were excluded.

Results: Seven studies with a total of 195 patients were included. No difference in the improvement of mean pulmonary arterial pressure (pooled difference in mean change= ?0.10, 95% CI: ?3.98 to 3.78, p?=?.959) or pulmonary vascular resistance (pooled standardized difference in mean change= ?0.27, 95% CI: ?0.60 to 0.05, p?=?.099) were found between the two treatments. Similarly, no difference was found in other outcomes between the two treatments or subgroup analysis.

Conclusions: Inhaled prostacyclin (or analogues) was comparable to inhaled NO in treating PH after cardiac or pulmonary surgery.

• Key messages

• This study compared the efficacy of inhaled prostacyclin or its analogues versus inhaled NO to treat PH after surgery. The two types of agent exhibited similar efficacy in managing MPAP, PVR, heart rate, and cardiac output was observed.

• Inhaled prostacyclin may serve as an alternative treatment option for PH after cardiac or pulmonary surgery.

     

Comparison of epidermal keratinocytes and dermal fibroblasts as potential target cells for somatic gene therapy of phenylketonuria

Phenylketonuria (PKU) is caused by deficiency of phenylalanine hydroxylase (PAH) and increased levels of phenylalanine. PAH requires the cofactor BH(4) to function and the rate-limiting step in the synthesis of BH(4) is GTP cyclohydrolase I (GTP-CH). The skin is a potential target tissue for PKU gene therapy. We have previously shown that overexpression of PAH and GTP-CH in primary human keratinocytes leads to high levels of phenylalanine clearance without BH(4) supplementation [Gene Ther. 7 (2000) 1971]. Here, we investigate the capacity of fibroblasts, another cell type from the skin, to metabolize phenylalanine. After retroviral gene transfer of PAH and GTP-CH both normal and PKU patient fibroblasts were able to metabolize phenylalanine, however, in lower amounts compared to genetically modified keratinocytes. Further comparative analyses between keratinocytes and fibroblasts revealed a higher copy number of transgenes in keratinocytes and also a higher metabolic capacity.     

Molecular basis of phenylketonuria and related hyperphenylalaninemias: mutations and polymorphisms in the human phenylalanine hydroxylase gene.

Mutations in the human phenylalanine hydroxylase gene producing phenylketonuria or hyperphenylalaninemia have now been identified in many patients from various ethnic groups. These mutations all exhibit a high degree of association with specific restriction fragment-length polymorphism haplotypes at the PAH locus. About 50 of these mutations are single-base substitutions, including six nonsense mutations and eight splicing mutations, with the remainder being missense mutations. One splicing mutation results in a 3 amino acid in-frame insertion. Two or 3 large deletions, 2 single codon deletions, and 2 single base deletions have been found. Twelve of the missense mutations apparently result from the methylation and subsequent deamination of highly mutagenic CpG dinucleotides. Recurrent mutation has been observed at several of these sites, producing associations with different haplotypes in different populations. About half of all missense mutations have been examined by in vitro expression analysis, and a significant correlation has been observed between residual PAH activity and disease phenotype. Since continuing advances in molecular methodologies have dramatically accelerated the rate in which new mutations are being identified and characterized, this register of mutations will be updated periodically.     

Assessment of polynuclear aromatic hydrocarbons ecotoxicity threshold in marine sediments through in situ input/decay measurements

The ability of decomposers to process variable amounts of xenobiotics in the marine sediment is a useful aggregate indicator of their capacity to prevent their accumulation and eventual ecotoxic effects. Since decomposition processes depend on environmental factors at the sediment which are difficult to mimic in laboratory systems, in situ evaluations in undisturbed sediments are of great interest. A method and its results are presented to evaluate the decomposition rates of PAHs (polynuclear aromatic hydrocarbons) in coastal undisturbed marine sediments at different levels of pollution input. The method is based on the application of pulse chromatography concepts to interpret trap and bed sediment monitoring data obtained at regular time intervals, using models of the water column as an anisotropic carrying medium. The results are for a 14 month data series from moderately polluted sediments near an urban site and at a more distant nearly pristine site on the south Atlantic coast. QSAR (quantitative structure activity relations) indicate that decay rates increase with higher UV absorption and lipidic solubility. At low levels of total PAH input to the sediments (<0.05 g day^–1 g^–1), decomposition mechanisms effectively process these compounds within a few days. At higher input levels (up to 0.12 g day^–1 g^–1), decomposition lags behind the inputs by approximately 25% and PAHs accumulate in the sediment. In situ estimates of the PAH input/decay ratios provide reliable ecosystem indicators of a safe threshold for anthropogenic inputs of PAHs to the marine environment and a basis for receptor-based standards aimed at their regulation.     

九个苯丙氨酸羟化酶基因单点突变重组质粒的构建和鉴定

目的构建Y154H、R157I、Y206C、G247R、D282G、G346R、S349A、A389G、R400K9个PAH基因突变型重组质粒,为下一步研究这些PAH突变体在哺乳动物细胞中表达蛋白功能奠定基础。方法①选择错义突变位点。结合突变位点所在酶蛋白的结构域(如催化结构域或与辅因子BH4结合位点)及患儿相关临床表型进行了9个突变位点的选择。②构建PAH基因突变型重组质粒。以野生型PAH真核表达载体pcDNA3.0-PAH-wt为模板,应用PrimerPremier5.0软件自行设计了9对突变引物,并在Platin-iumTaqDNA高保真聚合酶的作用下直接利用体外PCR定点突变法构建PAH基因突变型重组质粒。③初筛PAH基因突变型重组质粒。氨苄抗性初步筛选:利用重组基因含氨苄青霉素抗性基因的特点,可筛选出阳性克隆;PCR及酶切技术筛选:根据野生型与突变型靶序列酶切片段的差异进行筛选,其中S349A、D282G、G247R、Y206C、Y154H这5种突变存在MvaⅠ、MvaⅠ、HindⅢ、RsaⅠ、RsaⅠ的天然酶切位点,而R157I、G346R、A389G、R400K与其相应的野生型所在位点周围并不存在天然的酶切位点,需要在目的位点的上/下游设计引物,即人工构建DdeⅠ、HindⅢ、PstⅠ、MvaⅠ酶切位点,然后利用上述限制性内切酶进行突变体的酶切鉴定。④验证PAH基因突变型重组质粒,突变体最终由DNA测序加以验证。结果这9个突变型PAHcDNA序列除特定碱基位点被突变的碱基替换外,其他序列和野生型的完全保持一致。结论成功构建了9个PAH基因突变型重组质粒。体外定点突变技术准确、实用。     

Spanish smoked meat products: Benzo(a)pyrene (BaP) contamination and moisture

Traditional direct smoking is used for drying and flavouring foodstuffs, although carcinogenic compounds are added during this process, namely polycyclic aromatic hydrocarbons (PAH). The maximum permissible content of benzo(a)pyrene (BaP) (a current marker for the occurrence and effect of PAH in foods) in smoked meat products was reduced from 5 to 2 μg/kg on 1/09/2014, in compliance with European Regulation No. 835/2011. In this study, an analytical method has been developed to determine BaP content consisting of PAH extraction assisted by sonication followed by solid-phase extraction sample clean-up and analytical determination using gas chromatography/mass spectrometry. Sixteen commercial chorizo samples from 16 different Spanish producers from the Principality of Asturias were studied. Five of the samples exceeded the 2 ppb BaP limit. The relationship between moisture and BaP content in chorizo was examined, in order to verify the quality of the manufacturing process. Moisture content did not correlate with BaP content in chorizo.     

Mutational spectrum of the phenylalanine hydroxylase gene in patients with phenylketonuria in the central region of China

Phenylketonuria (PKU, OMIM 261600) caused by phenylalanine hydroxylase (PAH) deficiency is an autosomal recessive disease that is characterized by abnormalities of phenylalanine metabolism. In this study, a total of 77 patients, originating from the central region of China and who were diagnosed with PAH deficiency at the third affiliated hospital of Zhengzhou University, were enrolled in this study. The 13 exons and 12 flanking introns of the PAH gene were analyzed by Sanger sequencing and next generation sequencing. The sequencing data were aligned to the hg19, PAHvdb and HGMD databases to characterize the genotypes of PKU patients, and genotype–phenotype correlations and BH4 responsiveness predictions were performed using BIOPKUdb. In total, 149 alleles were characterized among the 154 PKU alleles. These mutations were located in exons 2–13, and intron 12 of the PAH gene, with a relative frequency of ≥5%, for EX6-96A>G, p.R241C, p.R243Q, p.V399V and p.R53H. Additionally, a novel variant, p.D84G, was identified. The genotype correlated with clinical symptoms in 33.3–100% of the cases, depending on the disease severity, and BH4 responsiveness predictions show that only five patients with MHP-PKU and one patient with Mild-PKU were predicted to be BH4 responsive. In conclusion, we have characterized the mutational spectrum of PAH in the central region of China and have identified a novel mutation. The hotspot mutation information might be useful for screening, diagnosis and treatment of PKU.