The mechanism and long-term consequences of early blood–brain barrier (BBB) disruption after cerebral ischaemic/reperfusion (I/R) injury are poorly understood. Here we discover that I/R induces subtle BBB leakage within 30–60 min, likely independent of gelatinase B/MMP-9 activities. The early BBB disruption is caused by the activation of ROCK/MLC signalling, persistent actin polymerization and the disassembly of junctional proteins within microvascular endothelial cells (ECs). Furthermore, the EC alterations facilitate subsequent infiltration of peripheral immune cells, including MMP-9-producing neutrophils/macrophages, resulting in late-onset, irreversible BBB damage. Inactivation of actin depolymerizing factor (ADF) causes sustained actin polymerization in ECs, whereas EC-targeted overexpression of constitutively active mutant ADF reduces actin polymerization and junctional protein disassembly, attenuates both early- and late-onset BBB impairment, and improves long-term histological and neurological outcomes. Thus, we identify a previously unexplored role for early BBB disruption in stroke outcomes, whereby BBB rupture may be a cause rather than a consequence of parenchymal cell injury.

Fast Free-of-Acrylamide Clearing Tissue (FACT) is a new sodium dodecyl sulfate (SDS)-based clearing protocol for the chemical clearing and imaging of brain tissue containing transgenic or immunolabeled fluorescent proteins. In the present study, we have developed this new method and optimized multiple dimensions of the workflow, including reduced clearing time, improved efficiency of fluorescent signals without the need for electrophoretic or complex instrumentations, preservation of cytoarchitectural details, optimized confocal microscopy, and accelerated data collection. We systematically compared seven clearing protocols with the FACT protocol, using transgenic mouse brains with fluorochrome expression in microglia. Only six days were required for detecting transgene-labeled markers in a 1-mm thick brain slice from adult mice, and 14 days were required for detecting antibody-labeled markers in the same-sized tissue. Preservation of fluorescent signal was achieved by decreasing clearing time, adjusting the pH of the SDS solution, and using the appropriate temperature for tissue clearing, all of which contributed to the superiority of our method. We conclude that the FACT protocol can be successfully applied to the fluorescent imaging of mouse brain tissue, and will facilitate structural analyses and connectomics of large assemblies of cells and their networks in the context of three-dimensional organ systems.

Background and Purpose Type-2 diabetes mellitus (T2DM) is a major comorbidity that exacerbates ischemic brain injury and worsens functional outcome after stroke. T2DM is known to aggravate white matter impairment but the underlying mechanism is not completely understood. This study was designed to test the hypothesis that T2DM impedes post-stroke white matter recovery by suppressing both oligodendrogenesis and beneficial microglia/macrophage responses. Methods Permanent distal middle cerebral artery occlusion was performed in wild-type, homozygous diabetic db/db, and heterozygous db/+ mice. The adhesive removal, open field, and Morris water maze tests were used to assess neurobehavioral outcomes. Neuronal tissue loss, white matter damage, oligodendrogenesis, and microglia/macrophage responses were evaluated up to 35d after stroke. The functional integrity of white matter was measured by electrophysiology. Primary microglia-oligodendrocyte co-cultures were used for additional mechanistic studies. Results T2DM exacerbated structural damage and impaired conduction of compound action potentials in white matter 35d after stroke. The deterioration in white matter integrity correlated with poor sensorimotor performance. Furthermore, T2DM impaired the proliferation of oligodendrocyte precursor cells (OPCs) and the generation of new myelinating oligodendrocytes. T2DM also promoted a shift of microglia/macrophage phenotype toward the pro-inflammatory modality. Co-culture studies confirmed that microglia/macrophage polarization toward the pro-inflammatory phenotype under high glucose conditions suppressed OPC differentiation. Conclusions Deterioration of white matter integrity and impairments in oligodendrogenesis after stroke are associated with poor long-term functional outcomes in experimental diabetes mellitus. High glucose concentrations may shift microglia/macrophage polarization toward a pro-inflammatory phenotype, significantly impairing OPC differentiation and white matter repair.

Aims To explore whether educational information delivered via a medical smartphone app in conjunction with verbal and written instructions, compared with traditional booklet‐based and verbal instructions, could improve the quality of bowel preparation for hospitalized patients undergoing colonoscopy. Design A prospective, single‐blinded, randomized controlled trial. Methods We performed a prospective, endoscopist‐blinded, randomized, controlled trial at Qilu Hospital of Shandong University in China between October 2017–March 2018. Inpatients who are eligible, based on the inclusion criteria, were randomized into two groups. Both groups received oral and written instructions for bowel preparation. In addition, the smartphone app group received instructions through a medical smartphone app. The primary outcome was the rate of adequate bowel preparation according to the Boston bowel preparation scale score. The secondary outcomes included patient compliance with instructions on how to take laxatives, side effects and rates of adenoma detection. Results A total of 293 patients were enrolled in this study. Demographic characteristics were comparable between the two groups. The χ2 test showed that the medical smartphone app group showed significant improvement in the rate of adequate bowel preparation compared with the control group (77.2% vs. 56.8%, p < .001). The adenoma detection rate (ADR) was significantly higher in the smartphone app group than in the control group (21.4% vs. 12.8%, p = .029) based on the χ2 test. The rates of incomplete compliance with instructions were 15.17% in the smartphone app group and 33.11% in the control group (p < .001) based on the χ2 test. The overall adverse events were 23.45% and 37.84% in the smartphone app and control groups, respectively (p = .008), based on the χ2 test. Conclusion Instructions provided via a mobile social media app in conjunction with traditional verbal and written methods could improve the quality of bowel preparation, increase the ADR and decrease adverse effects. App instructions could be an effective addition to oral and written instructions for inpatients undergoing colonoscopy. Impact This study suggested that clinical personnel could deliver information via smartphone as a powerful addition to traditional educational methods that could improve work efficiency and help patients increase the success rate of bowel preparation. Trial registration: Chinese clinical trial registration number: ChiCTR1900024666.

China is the world’s leading country for potato production but potato is not native to China. To gain insights into the genetic diversity of potato germplasm various studies have been performed but no study has been reported for potato landraces in China. To improve the available genepool for future potato breeding programs, a diverse population containing 292 genotypes (including foreign elite lines, local landraces and cultivars) was developed and genotyped using 30 SSR markers covering the entire potato genome. A total of 174 alleles were detected with an average of 5.5 alleles per locus. The model-based structure analysis discriminated the population into two main sub-groups, which can be further subdivided into seven groups based on collection sites. One sub-group (P1) revealed less genetic diversity than other (P2) and contained a higher number of commercial cultivars possibly indicating a slight reduction in diversity due to selection in breeding programs. The P2 sub-group showed a wider range of genetic diversity with more new and unique alleles attained from wild relatives. The potato landraces, clustered in sub-population P1 may be derived from historical population imported from ancient European and International Potato Center genotypes while sub-population P2 may be derived from modern populations from International Potato Center and European genotypes. It is proposed that in the first step, the potato genotypes were introduced from Europe to China, domesticated as landraces, and then hybridized for modern cultivars.