A novel classification of lateral malleolus morphological characteristics based on three-dimensional computed tomography reconstruction.

BACKGROUND: The study was to establish a novel classification of the morphological characteristics of fibula anterior-inferior margin (FAIM), which was reported in few studies. METHODS: The 501 images with three-dimensional computed tomography (3D CT) reconstruction were reviewed retrospectively. The width, height, thickness, long axis, short axis, and lateral malleolus angle were measured. RESULTS: The FAIM was divided into Angular, Flat, and Arc. The Flat has no distinct fibular obscure tubercles (FOT). The short axis of Angular and Arc were more significant than the Flat (P < 0. 05). The height of left was larger than the right, but short axis was less than it (P < 0.05). The height and short axis of males were larger than the females (P < 0.05). CONCLUSIONS: A novel classification (the Angular, Flat and Arc) of FAIM was identified based on lateral malleolus morphology, and it suggested that not all have obvious FOT. LEVEL OF EVIDENCE: Level Ⅲ, retrospective study.

Neuronal extracellular vesicles and associated microRNAs induce circuit connectivity downstream BDNF.

Extracellular vesicles (EVs) have emerged as mediators of cellular communication, in part via the delivery of associated microRNAs (miRNAs), small non-coding RNAs that regulate gene expression. We show that brain-derived neurotrophic factor (BDNF) mediates the sorting of miR-132-5p, miR-218-5p, and miR-690 in neuron-derived EVs. BDNF-induced EVs in turn increase excitatory synapse formation in recipient hippocampal neurons, which is dependent on the inter-neuronal delivery of these miRNAs. Transcriptomic analysis further indicates the differential expression of developmental and synaptogenesis-related genes by BDNF-induced EVs, many of which are predicted targets of miR-132-5p, miR-218-5p, and miR-690. Furthermore, BDNF-induced EVs up-regulate synaptic vesicle (SV) clustering in a transmissible manner, thereby increasing synaptic transmission and synchronous neuronal activity. As BDNF and EV-miRNAs miR-218 and miR-132 were previously implicated in neuropsychiatric disorders such as anxiety and depression, our results contribute to a better understanding of disorders characterized by aberrant neural circuit connectivity.