查看更多>>摘要：Two tiny muscles are attached to the ossicles of the middle ear: the stapedius, whose role as a protector of the inner ear against loud noise has been widely accepted, and the tensor tympani, which remains a mystery since no valid method of detecting its contraction has yet been developed. However, tonic contraction of the tensor tympani has been associated with a number of otological conditions including fullness, tinnitus, slight hearing loss, and Menie`re-like findings. Our hypothesis is that an easily recognizable sign in the acoustic immittance testing that is part of almost every basic audiological evaluation indicates the contraction of the tensor tympani. During acoustic reflex assessment, a loud stimulus causes a bilateral contraction of the stapedial muscles and an increase in impedance which appears as a deflection in the tracing of the immittance test results. In the case of a contracted tensor tympani, when an intense sound is sent to provoke the acoustic reflex, the stapedius must overcome its resistance which would otherwise have the opposite effect on the footplate. This effort can be seen as a small peak or "preshoot" preceding the greater negative deflection of the impedance. We report the cases of ten patients with unilateral aural symptoms such as tinnitus, impaired noise tolerance, fullness, ear pressure and/ or ear discomfort during chewing; the preshoot was present only in the symptomatic ear. If further studies confirm our hypothesis, this could give rise to new therapeutical strategies aimed at reducing contraction of the tensor tympani and balancing its function.
查看更多>>摘要：Obesity and type 2 diabetes are major factors in COVID-19 causing a progression to excessive morbidity and mortality. An important characteristic of these conditions is poor glycaemic control leading to inappropriate chemical reactions and the production of glycated proteins in which positively charged lysine and arginine residues are neutralised. We propose that this protein glycation primes the inflammatory system as the presence of aspartate and glutamate residues in any glycated zwitterionic protein will thus increase its anionic characteristics. As a result, these macromolecules will be recognised by the innate immune system and identified as originating from infection or cell damage (sterile inflammation). Many proteins in the body exist to nonspecifically target these anionic macromolecules and rely heavily on positively charged (cationic) bindingsites to produce a relatively non-specific interaction as the first step in the body's response. Proteins involved in this innate immunity are collectively referred to as damage associated molecular pattern molecules or pathogen associated molecular pattern molecules. A crucial player in this process is RAGE (Receptor for Advanced Glycation End products). RAGE plays a central role in the inflammatory response and on ligand binding stimulates many aspects of inflammation including the production of the key inflammatory mediator NF-Kappa B, and the subsequent production of inflammatory cytokines. This process has the potential to show a positive feedback loop resulting in a dramatic response within the tissue. We propose that protein glycation primes the inflammatory system by generating negatively charged surfaces so that when a SARS-Cov-2 infection occurs within the lung the further release of negatively-charged macromolecules due to cell damage results in a potentially catastrophic inflammatory response resulting in the cytokine storm associated with COVID-19 morbidity and mortality. That part of the population who do not suffer from inflammatory priming (Phase 1), such as the young and the non-obese, should not be subjected to the catastrophic inflammatory response seen in others (Phase 2). This hypothesis further highlights the need for improved dietary intake to minimise the inflammatory priming resulting from poor glycaemic control.
NSTL
Elsevier