Gut Dysbiosis Is Associated With the Severity of Cryptogenic Stroke and Enhanced Systemic Inflammatory Response.

Studies implicate that gut dysbiosis is related with many neurological diseases. However, the potential role of gut dysbiosis in cryptogenic stroke (CS) has not been elucidated yet. In this study, a high prevalence of gastrointestinal (GI) dysfunction and gut inflammation with increased intestinal permeability have been found in CS patients compared with normal controls (NCs). The systemic inflammation in CS patients was also identified by measuring the levels of plasma C-reactive protein (CRP), lipopolysaccharide (LPS), LPS-binding protein (LBP), and white blood cells (WBC) count. Using 16S rRNA sequencing, we found increased alpha diversity, accompanied by a higher abundance of Enterobacteriaceae, Streptococcaceae, and Lactobacillaceae at the family level and Escherichia-Shigella, Streptococcus, Lactobacillus, and Klebsilla at the genus level in the intestinal microbiota of CS patients compared to NCs. Our results showed that the abundance of Klebsilla was positively correlated with the systemic inflammation, the National Institutes of Health Stroke Scale (NIHSS) scores, and the infarct volumes. In conclusion, gut dysbiosis in CS patients was associated with the severity of CS and the systemic inflammation. Maintaining the intestinal homeostasis may be a potential strategy for the treatment of CS.

Lysozyme (Lys), Tannic Acid (TA), and Graphene Oxide (GO) Thin Coating for Antibacterial and Enhanced Osteogenesis.

Dental implants have great potential in the global market, around $3.7 billion in 2015, which will increase to $7 billion in 2023 with an annual increase rate of 8.2%. Incorporating antibacterial and osteogenic agents into implants is helpful to make the dental implants successful, which can be endowed by coatings. In recent years, graphene oxide (GO) and its composite materials have shown advances in the biomedical field. Lysozyme (Lys) and tannic acid (TA) are naturally derived, with promising antibacterial and osteogenic properties as well. In the present study, the strong antibacterial and enhanced osteogenic multilayer coating is fabricated using the facile and controllable layer by layer (LBL) technique to integrate GO, Lys, and TA. The thickness of coating exhibited a continuous growth with the deposited process as proved from UV-vis and ellipsometry data, and the physical properties of the coating, such as wettability, roughness, and stiffness are well characterized. The coatings exhibited the synergic effect on the killing bacteria, both Gram-negative bacteria and Gram-positive bacteria represented by E. coli and S. aureus, respectively, and enhancing osteogenesis of dental pulp stem cells (hDPSCs), showing the potential application on coatings of dental implants. Thus, the strategy applied here will inspire the design and development of dual functional surfaces for the success of implanted dental surface in future.

[Determination of Nicotine and Cotinine in Urine by Dispersive Liquid-Liquid Microextraction Combined with Gas Chromatography-Mass Spectrometry].

OBJECTIVE: To develop a method for the determination of nicotine and cotinine in urine samples by dispersive liquid-liquid microextraction (DLLME) combined with gas chromatography-mass spectrometry (DLLME-GC/MS). METHODS: The experimental conditions for GC-MS and DLLME were investigated in detail. DLLME was performed with the following procedure: 5 mL of urine sample was adjusted to pH9. 0 with NaOH solution; NaCl was added to increase ionic strength; 100 µL chloroform (containing internal standard of quinolone) as extractant was mixed with 1 000 pL methanol as dispersant and then injected into the urine sample to make it emulsified and dispersed. The sample solution was centrifuged for 5 min at 4,000 r/min, and 1 µL of its extraction solvent was injected into the GC/MS system for analysis. GC separation was performed with DB-5 column under programmed temperature. Nicotine and cotinine were quantified using selected ion monitoring (SIM) mode of mass spectrum detection and internal standard working curve. RESULTS: Good linear relationship was obtained for detecting nicotine and cotinine ranging from 0. 2 ng/mL to 100 ng/mL, with a detection limit of 0. 010 ng/mL and 0. 022 ng/mL for nicotine and cotinine respectively. The relative standard derivation (RSD) for determination of nicotine and cotinine in urine samples were 8.2% and 9.6% respectively. The spiked recoveries ranged from 92.0% to 108.0% for nicotine, 83.0% to 110.0% for cotinine. CONCLUSION: The method is rapid, sensitive, accurate and simple, with little consumption of organic solvent. It is suitable for determination of nicotine and cotinine in urine, and can meet the requirements for evaluating human tobacco exposure.