Injection of botulinum toxin A in lateral pterygoid muscle as a novel method for prevention of traumatic temporomandibular joint ankylosis

AbstractTemporomandibular joint (TMJ) ankylosis can restrict the mandibular movement, followed by resulting in numerous problems. To understand the mechanism of TMJ ankylosis (TMJA) and prevent the generation of TMJA is urgent necessary. Although many factors contribute to it, trauma is the most common cause of TMJA. The mechanisms of TMJA are still unclear, and the distraction osteogenesis of the lateral pterygoid muscle (LPM) may play an important role. Injection of very small amounts of botulinum toxin type A (BTA) can temporarily block the muscle’s impulse and has been revealed to be an effective treatment method for many temporomandibular disorders. In this article, we make a hypothesis that LPM injection of BTA as a novel method for immobilization of mandible, followed by preventing the traumatic TMJA. Furthermore, the side effects of local injection of BTA also are minimal, temporary, reversible and self-limiting. If this strategy is validated, LPM injection of BTA will be a cost effective way to be administrated to prevent the traumatic TMJA

Anti-inflammatory Effects of α7-nicotinic ACh Receptors are Exerted Through Interactions with Adenylyl Cyclase-6

Background and purpose Alpha 7 nicotinic acetylcholine receptors (CHRNA7) suppress inflammation through diverse pathways in immune cells, so is potentially involved in a number of inflammatory diseases. However, the detailed mechanisms underlying CHRNA7’s anti‐inflammatory effects remain elusive. Experimental approach The anti‐inflammatory effects of CHRNA7 agonists in both murine macrophages (RAW 264.7) and bone marrow‐derived macrophages (BMDM) stimulated with LPS were examined. The role of adenylyl cyclase 6 (AC6) in Toll‐like Receptor 4 (TLR4) degradation was explored via overexpression and knockdown. A mouse model of chronic obstructive pulmonary disease was used to confirm key findings. Results Anti‐inflammatory effects of CHRNA7 were largely dependent on AC6 activation, as knockdown of AC6 considerably abnegated the effects of CHRNA7 agonists while AC6 overexpression promoted them. We found that CHRNA7 and AC6 are co‐localized in lipid rafts of macrophages and directly interact. Activation of AC6 led to the promotion of TLR4 degradation. Administration of CHRNA7 agonist PNU‐282987 attenuated pathological and inflammatory end points in a mouse model of chronic obstructive pulmonary disease (COPD). Conclusion and implications CHRNA7 inhibits inflammation through activating AC6 and promoting degradation of TLR4. The use of CHRNA7 agonists may represent a novel therapeutic approach for treating COPD and likely other inflammatory diseases

Search for light dark matter from atmosphere in PandaX-4T

We report a search for light dark matter produced through the cascading decay of $\eta$ mesons, which are created as a result of inelastic collisions between cosmic rays and Earth's atmosphere. We introduce a new and general framework, publicly accessible, designed to address boosted dark matter specifically, with which a full and dedicated simulation including both elastic and quasi-elastic processes of Earth attenuation effect on the dark matter particles arriving at the detector is performed. In the PandaX-4T commissioning data of 0.63 tonne$\cdot$year exposure, no significant excess over background is observed. The first constraints on the interaction between light dark matter generated in the atmosphere and nucleus through a light scalar mediator are obtained. The lowest excluded cross-section is set at $5.9 \times 10^{-37}{\rm cm^2}$ for dark matter mass of $0.1$ MeV$/c^2$ and mediator mass of 300 MeV$/c^2$. The lowest upper limit of $\eta$ to dark matter decay branching ratio is $1.6 \times 10^{-7}$

A Search for Light Fermionic Dark Matter Absorption on Electrons in PandaX-4T

We report a search on a sub-MeV fermionic dark matter absorbed by electrons with an outgoing active neutrino using the 0.63 tonne-year exposure collected by PandaX-4T liquid xenon experiment. No significant signals are observed over the expected background. The data are interpreted into limits to the effective couplings between such dark matter and electrons. For axial-vector or vector interactions, our sensitivity is competitive in comparison to existing astrophysical bounds on the decay of such dark matter into photon final states. In particular, we present the first direct detection limits for an axial-vector (vector) interaction which are the strongest in the mass range from 25 to 45 (35 to 50) keV/c$^2$