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Dendritic arbors are crucial for nervous system assembly, but the intracellular mechanisms that govern their assembly remain incompletely understood. Here, we show that the dendrites of PVD neurons in Caenorhabditis elegans are patterned by distinct pathways downstream of the DMA-1 leucine-rich transmembrane (LRR-TM) receptor. DMA-1/LRR-TM interacts through a PDZ ligand motif with the guanine nucleotide exchange factor TIAM-1/GEF in a complex with act-4/Actin to pattern higher order 4° dendrite branches by localizing F-actin to the distal ends of developing dendrites. Surprisingly, TIAM-1/GEF appears to function independently of Rac1 guanine nucleotide exchange factor activity. A partially redundant pathway, dependent on HPO-30/Claudin, regulates formation of 2° and 3° branches, possibly by regulating membrane localization and trafficking of DMA-1/LRR-TM. Collectively, our experiments suggest that HPO-30/Claudin localizes the DMA-1/LRR-TM receptor on PVD dendrites, which in turn can control dendrite patterning by directly modulating F-actin dynamics through TIAM-1/GEF. [ABSTRACT FROM AUTHOR]

Statement of problem The laboratory-based enamel acid-etching doctrine with 30% to 50% phosphoric acid for 60 seconds to generate the maximum amount of Type 1 and/or Type 2 etch pattern has been established for more than 30 years. However, this recommendation may not be clinically relevant. Purpose The purpose of this systematic review was to compare clinically accepted protocols of enamel acid etching with the laboratory protocol. Material and methods Studies were identified by searching 4 electronic databases: Medline, CINAHL Plus, Embase, and Cochrane Library. The final search was run on November 8, 2012. All clinical studies published in English that investigated enamel acid pretreatment methods on human permanent teeth were included. Additional publications were obtained from the reference lists of the included studies. The clinical evidence of all included studies was tabulated. Results Initially, 4543 publications were retrieved from the databases. A total of 4508 articles were excluded, including 2285 duplicates, 1805 publications according to exclusion criteria by their titles and abstracts, 368 laboratory articles, 49 reviews, and 1 pilot study. Only 1 study was added from reference lists of the included studies. Finally, 36 clinical publications were included. The included clinical studies provided different levels of clinical evidence on the efficacy of acid-etching protocols to enable successful enamel adhesion. Conclusions Clinical protocols of enamel acid etching differ from the laboratory-generated doctrine, which may imply that maximization of the Type 1 and/or Type 2 etch pattern is not important in the clinical acid etching of human enamel. [ABSTRACT FROM AUTHOR]

Examines the status of Hong Kong after it was reverted to China on July 1, 1997. Political challenge that faced Hong Kong; Policy of the Chinese central government; Challenge to the dominance of the bureaucracy in the governance of Hong Kong.

Purpose: To investigate short- and long-term post-surgical three-dimensional changes of pharyngeal airway morphology and hyoid bone position in dento-skeletal class II deformity patients after two-jaw surgery with segmentation., Methods: Relations between skeletal movement, hyoid bone position and three-dimensional pharyngeal airway changes were retrospectively analyzed on pre- and post-surgical CBCTs in dento-skeletal class II patients who underwent orthognathic two-jaw surgery with segmentation., Results: While long-term significant reductions in length (P= 0.003), surface area (P= 0.042) and volume (P= 0.004) were found in the nasopharynx, the highly significant increases in oropharyngeal airway length, surface area, volume and the minimal cross-sectional area (P < 0.05) prevailed only in the short-term. Although a significant antero-superior movement of the hyoid bone was detected both in short- and long-term follow-up CBCTs (P < 0.05), only its superior, but not the anterior movement was found to be associated with an increased lateral width of the oropharyngeal minimal cross-sectional area., Conclusion: Two-jaw orthognathic surgery with segmentations in dento-skeletal class II patients improved oropharyngeal airway parameters significantly in the short-, but not long-term., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)