In this article, a panel of ssDNA aptamers specific to Staphylococcus aureus was obtained by a whole bacterium-based SELEX procedure and applied to probing S. aureus. After several rounds of selection with S. aureus as the target and Streptococcus and S. epidermidis as counter targets, the highly enriched oligonucleic acid pool was sequenced and then grouped under different families on the basis of the homology of the primary sequence and the similarity of the secondary structure. Eleven sequences from different families were selected for further characterization by confocal imaging and flow cytometry analysis. Results showed that five aptamers demonstrated high specificity and affinity to S. aureus individually. The five aptamers recognize different molecular targets by competitive experiment. Combining these five aptamers had a much better effect than the individual aptamer in the recognition of different S. aureus strains. In addition, the combined aptamers can probe single S. aureus in pyogenic fluids. Our work demonstrates that a set of aptamers specific to one bacterium can be used in combination for the identification of the bacterium instead of a single aptamer.

We report a new in situ tissue slide-based SELEX strategy targeting neoplastic tissues from breast cancer patients. The methodology, using the molecular differences between clinical specimens, can evolve aptamers to all fractions of tissue. The aptamers may be used as new molecular probes for pathological diagnosis and tumour imaging, and also to reveal the molecular differences that are responsible for the diseases. The specific aptamers were enriched by unequal length strand PCR employing a structured (-) strand primer. After 12 rounds of selection, using the paraffin tissue sections from infiltrating ductal carcinomas as targets, and using the adjacent normal tissue from the same case as controls, one of the enriched ssDNA aptamers, BC15, was selected from a nucleic acid library and characterized as recognizing breast cancer cells either within the tissue sections or from the culture medium, but only weakly binding to adjacent normal cells or immortalized breast cell line MCF10A. The calculated equilibrium dissociation constants (K(d)) of BC15 bound to MCF7 cells was 111.0 +/- 36.9 nM. Through streptavidin magnetic beads mediated affinity purification assay followed by mass spectrometry identification and western blot confirmation, the target of BC15 was characterized to be hnRNP A1, which was further verified to be specifically and highly expressed in cancerous tissues of breast by hnRNP A1 antibody immunostaining as well as western blot. BC15 aptamer was also used to probe cancer cells in tissues from other pathological types of breast cancers including lobular carcinoma, ductal carcinoma complicated with lobular carcinoma, comedo carcinoma, and lymph node metastasis of breast ductal carcinoma origin or breast lobular carcinoma origin. Therefore, tissue slide-based SELEX holds promise in identifying tumour markers and developing specific molecular probes for cancer diagnosis.

Hemoglobinopathies are among the most common autosomal-recessive disorders worldwide. A comprehensive next-generation sequencing (NGS) test would greatly facilitate screening and diagnosis of these disorders. An NGS panel targeting the coding regions of hemoglobin genes and four modifier genes was designed. We validated the assay by using 2522 subjects affected with hemoglobinopathies and applied it to carrier testing in a cohort of 10,111 couples who were also screened through traditional methods. In the clinical genotyping analysis of 1182 β-thalassemia subjects, we identified a group of additional variants that can be used for accurate diagnosis. In the molecular screening analysis of the 10,111 couples, we detected 4180 individuals in total who carried 4840 mutant alleles, and identified 186 couples at risk of having affected offspring. 12.1% of the pathogenic or likely pathogenic variants identified by our NGS assay, which were undetectable by traditional methods. Compared with the traditional methods, our assay identified an additional at-risk 35 couples. We describe a comprehensive NGS-based test that offers advantages over the traditional screening/molecular testing methods. To our knowledge, this is among the first large-scale population study to systematically evaluate the application of an NGS technique in carrier screening and molecular diagnosis of hemoglobinopathies.

Background: Neuromodulators are considered potential therapeutic options for refractory gastro-oesophageal reflux-induced chronic cough. Aim: To compare the efficacy of gabapentin and baclofen in patients with suspected refractory gastro-oesophageal reflux-induced chronic cough. Methods: Two hundred and thirty-four patients with suspected refractory gastrooesophageal reflux-induced chronic cough, who failed an 8-week course of omeprazole and domperidone, were recruited into the open-labelled study and randomly assigned to receive either gabapentin (maximum daily dose of 900 mg) or baclofen (maximum daily dose of 60 mg) for 8 weeks as add-on therapy to the previous treatment. The primary end point was the successful rate of cough resolution; and the secondary end-points included cough sensitivity to capsaicin and gastro-oesophageal reflux disease questionnaire score and reported side effects. Results:One hundred and eleven patients in the gabapentin group and 106 in the baclofen group completed the study. The overall success rate for cough resolution was comparable (57.3% vs 53.0%, χ 2 = 0.357, P = 0.550) between the two groups.In parallel, cough sensitivity to capsaicin and gastro-oesophageal reflux disease questionnaire score decreased after treatment with either gabapentin or baclofen.However, gabapentin was associated with less frequent somnolence (20.5% vs 35.0%, χ 2 = 6.156, P = 0.013) and dizziness (11.1% vs 23.9%, χ 2 = 6.654, P = 0.010) than baclofen. Conclusions:Gabapentin and baclofen have similar therapeutic efficacy for suspected refractory gastro-oesophageal reflux-induced chronic cough. However, gabapentin may be preferable because of fewer side effects. Trial Register: http:// www.chictr.org/; No.: ChiCTR-ONC-13003066.Ran Dong and Xianghuai Xu contributed equally to this work.