Sensitive and Extraction-Free Detection of Methicillin-Resistant Staphylococcus aureus through Ag+ Aptamer-Based Color Reaction.

Refractory infections, such as hospital-acquired pneumonia, can be better diagnosed with the assistance of precise methicillin-resistant Staphylococcus aureus (MRSA) testing. However, traditional methods necessitate high-tech tools, rigorous temperature cycling, and the extraction of genetic material from MRSA cells. Herein, we propose a sensitive, specific, and extraction-free strategy for MRSA detection by integrating allosteric probe-based target recognition and exonuclease-III (Exo-III)-enhanced color reaction. The penicillin-binding protein 2a (PBP2a) aptamer in the allosteric probe binds with MRSA to convert protein signals to nucleic acid signals. This is followed by the DNA polymerase-assisted target recycle and the production of numerous single-strand DNA (ssDNA) chains which bind with silver ion (Ag+) aptamer to form a blunt terminus that can be identified by Exo-III. As a result, the Ag+ aptamer pre-coupled to magnetic nanoparticles is digested. After magnetic separation, the Ag+ in liquid supernatant catalyzes 3,3',5,5'-tetramethylbenzidine (TMB) for a color reaction. In addition, a concentration of 54 cfu/mL is predicted to be the lowest detectable value. Based on this, our assay has a wide linear detection range, covering 5 orders of magnitude and demonstrating a high specificity, which allows it to accurately distinguish the target MRSA from other microorganisms.

Effects of Shenshao Decoction on the inflammatory response in the aorta of a rat atherosclerotic model.

OBJECTIVE: To investigate the effect of Shenshao Decoction on the inflammatory status: in the aorta in a rat model of atherosclerosis. METHODS: Forty Sprague-Dawley rats were randomly divided into: five groups, 8 rats in each group: control untreated group, atherosclerosis group, atherosclerosis with Shenshao Decoction (low dose) group, atherosclerosis with Shenshao Decoction (high dose) group, atherosclerosis with simvastatin group. To stimulate atherosclerosis, the rats were fed vitamin D3 and a high-cholesterol diet. Four weeks later, treatments were maintained for eight weeks. Morphology changes were investigated by hematoxylin and eosin staining. Serum levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were obtained by enzymatic assays with use of an automated biochemical analyzer. The expression of malondialdehyde (MDA), glutathione peroxidase (GSH-PX) were detected by enzyme-enzymelinked immunosorbent assay. The expression levels of interleukin (IL)-1ß, IL-17A, and IL-23 were detected by linked immunoblotting. RESULTS: Shenshao Decoction treatment decreased TC, TG, LDL-C and MDA and increased: GSH-PX levels (P<0.01). Compared with the control group, IL-1ß, IL-17A, and IL-23 were lower in the high and

Rho-associated coiled kinase inhibitor Y-27632 promotes neuronal-like differentiation of adult human adipose tissue-derived stem cells.

BACKGROUND: Y-27632 is a specific inhibitor of Rho-associated coiled kinase (ROCK) and has been shown to promote the survival and induce the differentiation of a variety of cells types. However, the effects of Y-27632 on adult human adipose tissue-derived stem cells (ADSCs) are unclear. This study aimed to investigate the effects of Y-27632 on the neuronal-like differentiation of ADSCs. METHODS: ADSCs were isolated from women undergoing plastic surgery and cultured. ADSCs were treated with different doses of Y-27632 and observed morphological changes under microscope. The expression of nestin, neuron specific enolase (NSE) and microtubule-associated protein-2 (MAP-2) in ADSCs treated with Y-27632 was detected by immunocytochemistry and Western blotting analysis. RESULTS: Y-27632 had the potency to induce neuronal-like differentiation in ADSCs in a dose-dependent manner. Moreover, the differentiation induced by Y-27632 was recovered upon drug withdraw. ADSCs treated with Y-27632 expressed neuronal markers such as NSE, MAP-2 and nestin while untreated ADSCs did not express these markers. CONCLUSION: Selective ROCK inhibitor Y-27632 could potentiate the neuronal-like differentiation of ADSCs, suggesting that Y-27632 could be utilized to induce the differentiation of ADSCs to neurons and facilitate the clinical application of ADSCs in tissue engineering.