Surgical anatomy of the facial nerve: from middle cranial fossa approach to endoscopic approach. A pictorial review.

Purpose: The pathology of the facial nerve is extremely varied and extensive knowledge of the surgical anatomy in different approaches is required to manage it. During the last 15 years, the development of endoscopic ear surgery has significantly changed anatomical concepts, introducing new surgical approaches. The aim of this review is to illustrate five different surgical approaches to the facial nerve: the endoscopic approach, the middle cranial fossa approach, two translabyrinthine approaches (one simple and one endoscopic-assisted) with decompression of the whole petrous portion of the facial nerve, and a transotic approach with temporal craniotomy. Methods: Representative cases of middle and/or inner ear pathologies, surgically treated at our ENT Department, were selected to illustrate each of the five different approaches involving the facial nerve throughout its course. Results: In all cases, the pathology was removed with effective decompression of the facial nerve. The surgical anatomy in each surgical approach is described and illustrated. Conclusions: Facial nerve surgery is challenging for ENT specialists. An excellent knowledge of facial nerve anatomy is needed to eradicate pathology, avoiding nerve injuries and providing a good outcome after surgery

Coherent QED, Giant Resonances and (e+e−)(e^{+}e^{-}) Pairs in High Energy Nucleus-Nucleus Collisions

We show that the coherent oscillations of the e.m. field induced by the collective quantum fluctuations of the nuclear matter field associated with the giant resonances, with frequencies $\omega_{A}\simeq 78A^{-{1/3}}$ MeV, give rise to a significant $(e^+e^-)$ pair production in high energy Heavy Ion collisions. The approximate parameterless calculation of such yield is in good agreement with recent experimental observations.Comment: 27 pages, 13 figure

Genome-wide identification of direct HBx genomic targets

Background: The Hepatitis B Virus (HBV) HBx regulatory protein is required for HBV replication and involved in HBV-related carcinogenesis. HBx interacts with chromatin modifying enzymes and transcription factors to modulate histone post-translational modifications and to regulate viral cccDNA transcription and cellular gene expression. Aiming to identify genes and non-coding RNAs (ncRNAs) directly targeted by HBx, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) to analyse HBV recruitment on host cell chromatin in cells replicating HBV. Results: ChIP-Seq high throughput sequencing of HBx-bound fragments was used to obtain a high-resolution, unbiased, mapping of HBx binding sites across the genome in HBV replicating cells. Protein-coding genes and ncRNAs involved in cell metabolism, chromatin dynamics and cancer were enriched among HBx targets together with genes/ncRNAs known to modulate HBV replication. The direct transcriptional activation of genes/miRNAs that potentiate endocytosis (Ras-related in brain (RAB) GTPase family) and autophagy (autophagy related (ATG) genes, beclin-1, miR-33a) and the transcriptional repression of microRNAs (miR-138, miR-224, miR-576, miR-596) that directly target the HBV pgRNA and would inhibit HBV replication, contribute to HBx-mediated increase of HBV replication. Conclusions: Our ChIP-Seq analysis of HBx genome wide chromatin recruitment defined the repertoire of genes and ncRNAs directly targeted by HBx and led to the identification of new mechanisms by which HBx positively regulates cccDNA transcription and HBV replication

Salvage neck dissection for isolated neck recurrences in head and neck tumors: Intra and postoperative complications

Background and Objectives: The current evidence regarding complications after salvage neck dissection (ND) for isolated regional recurrences (IRRs) in head and neck cancers is poor. The aim of this study is to evaluate the incidence and differences in complication rates of salvage ND after primary surgery, radiotherapy, chemoradiotherapy, or combined treatments. Methods: This was a multicentric retrospective study on 64 patients who underwent salvage ND for IRR in three Italian institutes between 2008 and May 2020. Results: Complications were detected in 7 of the 34 patients (20.8%) and surgeons described difficult dissection in 20 patients (58.82%). Accidental vascular ligations or nervous injury during surgery were never detected. None of the variables analyzed were statistically significant in predicting the risk of complications, disease-free survival, or overall survival. Conclusions: IRR represents a rare entity among total relapses. The incidence of complications after salvage ND for IRR is higher than after primary surgery but at an acceptable rate in experienced hands. However, an adequate balance between functional and oncological outcomes is mandatory

Isometric force production parameters during normal and experimental low back pain conditions

BACKGROUND: The control of force and its between-trial variability are often taken as critical determinants of motor performance. Subjects performed isometric trunk flexion and extension forces without and with experiment pain to examine if pain yields changes in the control of trunk forces. The objective of this study is to determine if experimental low back pain modifies trunk isometric force production. METHODS: Ten control subjects participated in this study. They were required to exert 50 and 75% of their isometric maximal trunk flexion and extension torque. In a learning phase preceding the non painful and painful trials, visual and verbal feedbacks were provided. Then, subjects were asked to perform 10 trials without any feedback. Time to peak torque, time to peak torque variability, peak torque variability as well as constant and absolute error in peak torque were calculated. Time to peak and peak dF/dt were computed to determine if the first peak of dF/dt could predict the peak torque achieved. RESULTS: Absolute and constant errors were higher in the presence of a painful electrical stimulation. Furthermore, peak torque variability for the higher level of force was increased with in the presence of experimental pain. The linear regressions between peak dF/dt, time to peak dF/dt and peak torque were similar for both conditions. Experimental low back pain yielded increased absolute and constant errors as well as a greater peak torque variability for the higher levels of force. The control strategy, however, remained the same between the non painful and painful condition. Cutaneous pain affects some isometric force production parameters but modifications of motor control strategies are not implemented spontaneously. CONCLUSIONS: It is hypothesized that adaptation of motor strategies to low back pain is implemented gradually over time. This would enable LBP patients to perform their daily tasks with presumably less pain and more accuracy

Coding potential of the products of alternative splicing in human

Background: Analysis of the human genome has revealed that as much as an order of magnitude more of the genomic sequence is transcribed than accounted for by the predicted and characterized genes. A number of these transcripts are alternatively spliced forms of known protein coding genes; however, it is becoming clear that many of them do not necessarily correspond to a functional protein. Results: In this study we analyze alternative splicing isoforms of human gene products that are unambiguously identified by mass spectrometry and compare their properties with those of isoforms of the same genes for which no peptide was found in publicly available mass spectrometry datasets. We analyze them in detail for the presence of uninterrupted functional domains, active sites as well as the plausibility of their predicted structure. We report how well each of these strategies and their combination can correctly identify translated isoforms and derive a lower limit for their specificity, that is, their ability to correctly identify non-translated products. Conclusions: The most effective strategy for correctly identifying translated products relies on the conservation of active sites, but it can only be applied to a small fraction of isoforms, while a reasonably high coverage, sensitivity and specificity can be achieved by analyzing the presence of non-truncated functional domains. Combining the latter with an assessment of the plausibility of the modeled structure of the isoform increases both coverage and specificity with a moderate cost in terms of sensitivity

Standing balance in persistent whiplash: A comparison between subjects with and without dizziness

Objective: Dizziness and unsteadiness, associated with altered balance, are frequent complaints in subjects suffering persistent whiplash associated disorders. Research has been inconclusive with respect to possible aetiology. This study assessed balance responses in subjects with whiplash associated disorders, taking into account several possible causes

Modulation in voluntary neural drive in relation to muscle soreness

The aim of this study was to investigate whether (1) spinal modulation would change after non-exhausting eccentric exercise of the plantar flexor muscles that produced muscle soreness and (2) central modulation of the motor command would be linked to the development of muscle soreness. Ten healthy subjects volunteered to perform a single bout of backward downhill walking exercise (duration 30 min, velocity 1 ms−1, negative grade −25%, load 12% of body weight). Neuromuscular test sessions [H-reflex, M-wave, maximal voluntary torque (MVT)] were performed before, immediately after, as well as 1–3 days after the exercise bout. Immediately after exercise there was a −15% decrease in MVT of the plantar flexors partly attributable to an alteration in contractile properties (−23% in electrically evoked mechanical twitch). However, MVT failed to recover before the third day whereas the contractile properties had significantly recovered within the first day. This delayed recovery of MVT was likely related to a decrement in voluntary muscle drive. The decrease in voluntary activation occurred in the absence of any variation in spinal modulation estimated from the H-reflex. Our findings suggest the development of a supraspinal modulation perhaps linked to the presence of muscle soreness

A pilot study using Tissue Velocity Ultrasound Imaging (TVI) to assess muscle activity pattern in patients with chronic trapezius myalgia

<p>Abstract</p> <p>Background</p> <p>Different research techniques indicate alterations in muscle tissue and in neuromuscular control of aching muscles in patients with chronic localized pain. Ultrasound can be used for analysis of muscle tissue dynamics in clinical practice.</p> <p>Aim</p> <p>This study introduces a new muscle tissue sensitive ultrasound technique in order to provide a new methodology for providing a description of local muscle changes. This method is applied to investigate trapezius muscle tissue response – especially with respect to specific regional deformation and deformation rates – during concentric shoulder elevation in patients with chronic trapezius myalgia and healthy controls before and after pain provocation.</p> <p>Methods</p> <p>Patients with trapezius myalgia and healthy controls were analyzed using an ultrasound system equipped with tissue velocity imaging (TVI). The patients performed a standardized 3-cm concentric shoulder elevation before and after pain provocation/exercise at a standardized elevation tempo (30 bpm). A standardized region of interest (ROI), an ellipsis with a size that captures the upper and lower fascia of the trapezius muscle (4 cm width) at rest, was placed in the first frame of the loop registration of the elevation. The ROI was re-anchored frame by frame following the same anatomical landmark in the basal fascia during all frames of the concentric phase. In cardiac measurement, tissue velocities are measured in the axial projection towards and against the probe where red colour represents shortening and red lengthening. In the case of measuring the trapezius muscle, tissue deformation measurements are made orthogonally, thus, indirectly. Based on the assumption of muscle volume incompressibility, blue represents tissue contraction and red relaxation. Within the ROI, two variables were calculated as a function of time: <it>deformation </it>and <it>deformation rate</it>. Hereafter, max, mean, and quadratic mean values (RMS) of each variable were calculated and compared before and after pain provocation/exercise.</p> <p>Results</p> <p>This new methodology seems valuable when looking at local muscle changes and studying the mechanism behind chronic muscle pain. The univariate analyses indicate that patients with chronic trapezius myalgia after pain provocation due to exercise at group level showed decreased strain and unchanged strain rate while healthy controls had unchanged strain and increased strain rate. However, the multivariate analysis indicates that most patients showed lower levels according to both strain and strain rate after exercise compared to most controls.</p> <p>Conclusion</p> <p>Tissue velocity imaging can help describe musculoskeletal tissue activity and dynamics in patients with chronic pain conditions. An altered muscle tissue dynamic after pain provocation/exercise among the majority of trapezius myalgia patients compared with the healthy controls was found.</p