Gold Coating of Silver Nanoplates for Enhanced Dispersion Stability and Efficient Antimicrobial Activity against Intracellular Bacteria.

Silver nanoparticles have antibacterial activity. However, the nanoparticles are unstable and easily form aggregates, which decreases their antibacterial activity. To improve the dispersion stability of silver nanoparticles in aqueous media and to increase their effectiveness as antibacterial agents, we coated triangular plate-like silver nanoparticles (silver nanoplates, Ag NPLs) with one or two layers of gold atoms (Ag@Au1L NPLs and Ag@Au2L NPLs, respectively). These gold coatings improved the dispersion stability in aqueous media with high salt concentrations. Ag@Au1L NPLs showed stronger antibacterial activity on pathogenic bacteria than Ag NPLs and Ag@Au2L NPLs. Furthermore, the Ag@Au1L NPLs decreased the number of bacteria in RAW 264.7 cells. The Ag@Au1L NPLs displayed no cytotoxicity towards RAW 264.7 cells and could be used as antibacterial agents for intracellular bacterial infections.

Panax notoginseng saponins promote hair follicle growth in mice via Wnt/ß-Catenin signaling pathway.

Panax notoginseng saponins (PNS), the active ingredients of the traditional Chinese medicine Panax notoginseng, have strong neuroprotective and anti-platelet aggregation effects. To investigate whether PNS can promote hair follicle growth in C57BL/6J mice, the optimal concentration of PNS was initially determined, followed by clarification of the mechanism underlying their effects. Twenty-five male C57BL/6J mice had the hair on a 2 × 3 cm2 area of the dorsal skin shaved and were equally divided into five groups: control group, 5% minoxidil (MXD) group, and three PNS treatment groups [2% (10 mg/kg), 4% (20 mg/kg), and 8% (40 mg/kg) PNS]. They were then intragastrically administered the corresponding drugs for 28 days. The effects of PNS on C57BL/6J mice were analyzed by subjecting their dorsal depilated skin samples to different assessments, including hematoxylin and eosin staining, immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting (WB). The group with 8% PNS exhibited the largest number of hair follicles from 14 days onwards. Compared with the control group, the number of hair follicles increased significantly in the mice treated with 8% PNS and 5% MXD, which significantly increased in a PNS-dose-dependent manner. Immunohistochemistry and immunofluorescence results revealed that treatment with 8% PNS activated the metabolism of hair follicle cells, with them showing higher rates of proliferation and apoptosis than those in the normal group. In qRT-PCR and WB analysis, the expression of ß-catenin, Wnt10b, and LEF1 was upregulated in the PNS and MDX groups compared with that in the control group. Examination of the WB bands revealed that the greatest inhibitory effect of Wnt5a occurred in mice in the 8% PNS group. PNS may promote the growth of hair follicles in mice, with 8% PNS demonstrating the strongest effect. The mechanism behind this may be related to the Wnt/ß-catenin signaling pathway.

Post-stroke seizure-Do the locations, types and managements of stroke matter?

OBJECTIVE: To determine the incidence of post-stroke seizures and the associated risk factors in a government-restructured hospital in Singapore. METHODS: This retrospective study included consecutive patients (age ≥21 years) admitted to the stroke rehabilitation facility at Changi General Hospital, Singapore, between June 2008 and May 2017, with a minimum post-discharge follow-up of 6 months. Patients with known epilepsy central nervous system infection or tumor, a history of neurosurgery and or missing data were excluded from study. To determine the incidence of seizures, the patients' hospital records, including those for all initial and subsequent admissions and outpatient follow-ups, were reviewed. All prescribed medications were checked and documented. Seizures were diagnosed on the basis of clinical examination with or without electroencephalography. RESULTS: In total, 722 patients (women, 38%) with a mean age of 64 years were included. Of these, 48 (6.64%) experienced post-stroke seizures during a follow-up period of 6-108 months. The incidence of seizures was significantly higher in patients with hemorrhagic stroke (42%, p = 0.010), those with ischemic partial anterior circulation stroke (PACS) (27%, p = 0.025), those who underwent a neurosurgical procedure after stroke (p < 0.001), those with a low activated partial thromboplastin time (APTT) at admission (mean, 25.6; p = 0.015), and those using levodopa (21%, p < 0.001). Neurosurgical intervention after stroke (odds ratio [OR] 6.2, 95% confidence interval [CI] 2.9-13.1; p < 0.001), APTT (per-unit increase; OR 0.86, 95% CI 0.76-0.98; p = 0.028), and underlying ischemic heart disease (IHD; OR 2.2, 95% CI 1.08-4.60; p = 0.029) were found to be independent predictors of seizure occurrence after stroke. SIGNIFICANCE: Post-stroke seizure incidence from our study is 6.64%, with a median follow-up of 49 months. Among patients with stroke, those with underlying IHD, those who undergo a neurosurgical procedure, and those with a low APTT at admission need careful monitoring. Levodopa should be used with caution and withdrawn as soon as possible.

Effects of pulsed laser irradiation on gold-coated silver nanoplates and their antibacterial activity.

Gold-coated silver nanoplates, when subjected to pulsed laser irradiation, changed their shape from triangular to spherical, accompanied by a shift of their extinction spectra. The simple single crystal structure of the silver nanoplates changed to multiple small crystal domains. The ratio of silver to gold of the particles also changed from 22 : 1 to 4.5 : 1, enabling more silver to be released. As a result, the antibacterial activity of the gold-coated silver nanoplates was significantly increased after pulsed laser irradiation.

Stroke in Myanmar: attitudes and treatment.

The burden of stroke in low-middle-income countries has increased during the past few decades but has decreased in developed countries and it is important to know why; though it may be attributed primarily to attitudes toward stroke management and prevention among doctors, and consequently in the population. We have conducted a study to investigate how stroke is managed in Myanmar, south-east Asia, with a population of approximately 60 million. We found that attitude differed markedly from that reflected in international guidelines. We expected this attitude to be reflected in the general population and speculate that the poor development and sub-optimal work on prevention and treatment of stroke stems from these attitudes.