Evaluation of Ion Torrent sequencing technology for rapid clinical human leucocyte antigen typing

The development of techniques to define the human leucocyte antigen (HLA) region has proven to be challenging due to its high level of polymorphism. Within a clinical laboratory, a technique for high‐resolution HLA typing, which is rapid and cost effective is essential. NGS has provided a rapid, high‐resolution HLA typing solution, which has reduced the number of HLA ambiguities seen with other typing methods. In this study, the One Lambda NXType NGS kit was tested on the Ion Torrent PGM platform. A total of 362 registry donors from four ethnic populations (Europeans, South Asians, Africans and Chinese) were NGS HLA typed across 9‐loci (HLA‐A, ‐B, ‐C, ‐DRB1,‐DRB345 ‐DQB1 and ‐DPB1). Concordance rates of 91%–98% were obtained (for HLA‐A, ‐B, ‐C, ‐DRB1, ‐DQB1 and ‐DPB1) when compared to historical PCR‐SSO HLA types, and the identification of uncommon alleles such as A*24:07:01 and C*04:82 were observed. A turnaround time of four days was achieved for typing 44 samples. However, some limitations were observed; primer locations did not allow all ambiguities to be resolved for HLA Class II where Exon I and IV amplification are needed (HLA‐DRB1*04:07:01/04:92, HLA‐DRB1*09:01:02/*09:21 and HLA‐DRB1*12:01:01/*12:10). This study has demonstrated high‐resolution typing by NGS can be achieved in an acceptable turnaround time for a clinical laboratory; however, the Ion Torrent workflow has some technical limitations that should be addressed.     

Combined in vitro and in silico analyses of missense mutations in GNPTAB provide new insights into the molecular bases of mucolipidosis II and III alpha/beta

Mucolipidosis (ML) II and III alpha/beta are inherited lysosomal storage disorders caused by mutations in GNPTAB encoding the α/β‐precursor of GlcNAc‐1‐phosphotransferase. This enzyme catalyzes the initial step in the modification of more than 70 lysosomal enzymes with mannose 6‐phosphate residues to ensure their intracellular targeting to lysosomes. The so‐called stealth domains in the α‐ and β‐subunit of GlcNAc‐1‐phosphotransferase were thought to be involved in substrate recognition and/or catalysis. Here, we performed in silico alignment analysis of stealth domain‐containing phosphotransferases and showed that the amino acid residues Glu³⁸⁹, Asp⁴⁰⁸, His⁹⁵⁶, and Arg⁹⁸⁶ are highly conserved between different phosphotransferases. Interestingly, mutations in these residues were identified in patients with MLII and MLIII alpha/beta. To further support the in silico findings, we also provide experimental data demonstrating that these four amino acid residues are strictly required for GlcNAc‐1‐phosphotransferase activity and thus may be directly involved in the enzymatic catalysis.     

Palliative noninvasive ventilation in patients with acute respiratory failure

Over the last two decades, the increasing use of noninvasive ventilation (NIV) has diminished the need for endotracheal ventilation, thus decreasing the rate of ventilation-induced complications. Thus, NIV has decreased both intubation rates and mortality rates in specific subsets of patients with acute respiratory failure (e.g., patients with hypercapnia, cardiogenic pulmonary edema, immune deficiencies, or post-transplantation acute respiratory failure). NIV is also increasingly used as a palliative strategy when endotracheal ventilation is deemed inappropriate. In this context, palliative NIV can either be administered to offer a chance for survival, or to alleviate the symptoms of respiratory distress in dying patients. The literature provides information from 10 studies published between 1992 and 2006, in which 458 patients received palliative NIV. The technique was feasible, usually well tolerated, and half of the patients survived. The objectives of this review article are to define palliative NIV, to delineate the place for palliative NIV among overall indications of NIV, and to define the contribution of NIV to the palliative strategies available for patients with acute respiratory failure. Potential benefits and harm from NIV in patients who are not eligible for endotracheal ventilation are discussed. The appropriateness of palliative NIV should be reported in a study that relies on both quantitative criteria (rate of palliative NIV use and mortality) and qualitative criteria (patient comfort, end-of-life process, family burden, and health-care provider satisfaction).     

Echoendoscopic ultrasound/fine needle aspiration of an hepatic cystadenoma

The diagnosis of hepatic cystadenoma is difficult with the conventional radiologic imaging. When these hepatobiliary cystic tumors are located in the left liver, Echoendoscopic ultrasound/Fine needle aspiration can help in the diagnosis by showing high levels of cystic CEA and CA 19-9 in a mucinous fluid. Definitive histological evaluation is assessed by the examination of the operative specimen.     

Solvent-induced selectivity of Williamson etherification in the pursuit of amides resistant against oxidative degradation

This article reports two discoveries. (1) 2-Methoxyethanol induces unprecedented selectivity for etherification of 5-hydroxy-2-nitrobenzic acids without forming undesired esters. (2) Such compounds are precursors for amides showing unusual robustness against oxidative degradation, essential for molecular electrets that transfer strongly oxidizing holes at about −6.4 eV vs. vacuum.

Selective etherification produces precursors for amides resistant to oxidative degradation, i.e., showing reversible oxidation at 1.5 to 1.7 V vs. SCE.