Characteristics of Tetanic Force Produced by the Sternomastoid Muscle of the Rat

The sternomastoid (SM) muscle plays an important role in supporting breathing. It also has unique anatomical advantages that allow its wide use in head and neck tissue reconstruction and muscle reinnervation. However, little is known about its contractile properties. The experiments were run on rats and designed to determine in vivo the relationship between muscle force (active muscle contraction to electrical stimulation) with passive tension (passive force changing muscle length) and two parameters (intensity and frequency) of electrical stimulation. The threshold current for initiating noticeable muscle contraction was 0.03 mA. Maximal muscle force (0.94 N) was produced by using moderate muscle length/tension (28 mm/0.08 N), 0.2 mA stimulation current, and 150 Hz stimulation frequency. These data are important not only to better understand the contractile properties of the rat SM muscle, but also to provide normative values which are critical to reliably assess the extent of functional recovery following muscle reinnervation

Force Characteristics of the Rat Sternomastoid Muscle Reinnervated with End-to-End Nerve Repair

The goal of this study was to establish force data for the rat sternomastoid (SM) muscle after reinnervation with nerve end-to-end anastomosis (EEA), which could be used as a baseline for evaluating the efficacy of new reinnervation techniques. The SM muscle on one side was paralyzed by transecting its nerve and then EEA was performed at different time points: immediate EEA, 1-month and 3-month delay EEA. At the end of 3-month recovery period, the magnitude of functional recovery of the reinnervated SM muscle was evaluated by measuring muscle force and comparing with the force of the contralateral control muscle. Our results demonstrated that the immediately reinnervated SM produced approximately 60% of the maximal tetanic force of the control. The SM with delayed nerve repair yielded approximately 40% of the maximal force. Suboptimal recovery of muscle force after EEA demonstrates the importance of developing alternative surgical techniques to treat muscle paralysis

Association between Incidental Pelvic Inflammation and Aggressive Prostate Cancer

The impact of pelvic inflammation on prostate cancer (PCa) biology and aggressive phenotype has never been studied. Our study objective was to evaluate the role of pelvic inflammation on PCa aggressiveness and its association with clinical outcomes in patients following radical prostatectomy (RP). This study has been conducted on a retrospective single-institutional consecutive cohort of 2278 patients who underwent robot-assisted laparoscopic prostatectomy (RALP) between 01/2013 and 10/2019. Data from 2085 patients were analyzed to study the association between pelvic inflammation and adverse pathology (AP), defined as Gleason Grade Group (GGG) > 2 and ≥ pT3 stage, at resection. In a subset of 1997 patients, the association between pelvic inflammation and biochemical recurrence (BCR) was studied. Alteration in tumor transcriptome and inflammatory markers in patients with and without pelvic inflammation were studied using microarray analysis, immunohistochemistry, and culture supernatants derived from inflamed sites used in functional assays. Changes in blood inflammatory markers in the study cohort were analyzed by O-link. In univariate analyses, pelvic inflammation emerged as a significant predictor of AP. Multivariate cox proportional-hazards regression analyses showed that high pelvic inflammation with pT3 stage and positive surgical margins significantly affected the time to BCR (p ≤ 0.05). PCa patients with high inflammation had elevated levels of pro-inflammatory cytokines in their tissues and in blood. Genes involved in epithelial-to-mesenchymal transition (EMT) and DNA damage response were upregulated in patients with pelvic inflammation. Attenuation of STAT and IL-6 signaling decreased tumor driving properties of conditioned medium from inflamed sites. Pelvic inflammation exacerbates the progression of prostate cancer and drives an aggressive phenotype.</p

The Mount Sinai Prebiopsy Risk Calculator for Predicting any Prostate Cancer and Clinically Significant Prostate Cancer: Development of a Risk Predictive Tool and Validation with Advanced Neural Networking, Prostate Magnetic Resonance Imaging Outcome Database, and European Randomized Study of Screening for Prostate Cancer Risk Calculator

Background: The European Association of Urology guidelines recommend the use of imaging, biomarkers, and risk calculators in men at risk of prostate cancer. Risk predictive calculators that combine multiparametric magnetic resonance imaging with prebiopsy variables aid as an individualized decision-making tool for patients at risk of prostate cancer, and advanced neural networking increases reliability of these tools.Objective: To develop a comprehensive risk predictive online web-based tool using magnetic resonance imaging (MRI) and clinical data, to predict the risk of any prostate cancer (PCa) and clinically significant PCa (csPCa) applicable to biopsy-naive men, men with a prior negative biopsy, men with prior positive low-grade cancer, and men with negative MRI.Design, setting, and participants: Institutional review board-approved prospective data of 1902 men undergoing biopsy from October 2013 to September 2021 at Mount Sinai were collected.Outcome measurements and statistical analysis: Univariable and multivariable analyses were used to evaluate clinical variables such as age, race, digital rectal examination, family history, prostate-specific antigen (PSA), biopsy status, Prostate Imaging Reporting and Data System score, and prostate volume, which emerged as predictors for any PCa and csPCa. Binary logistic regression was performed to study the probability. Validation was performed with advanced neural networking (ANN), multi-institutional European cohort (Prostate MRI Outcome Database [PROMOD]), and European Randomized Study of Screening for Prostate Cancer Risk Calculator (ERSPC RC) 3/4.Results and limitations: Overall, 2363 biopsies had complete clinical information, with 57.98% any cancer and 31.40% csPCa. The prediction model was significantly associated with both any PCa and csPCa having an area under the curve (AUC) of 81.9% including clinical data. The AUC for external validation was calculated in PROMOD, ERSPC RC, and ANN for any PCa (0.82 vs 0.70 vs 0.90) and csPCa (0.82 vs 0.78 vs 0.92), respectively. This study is limited by its retrospective design and over-estimation of csPCa in the PROMOD cohort.Conclusions: The Mount Sinai Prebiopsy Risk Calculator combines PSA, imaging and clinical data to predict the risk of any PCa and csPCa for all patient settings. With accurate validation results in a large European cohort, ERSPC RC, and ANN, it exhibits its efficiency and applicability in a more generalized population. This calculator is available online in the form of a free web-based tool that can aid clinicians in better patients counseling and treatment decision-making.Patient summary: We developed the Mount Sinai Prebiopsy Risk Calculator (MSP-RC) to assess the likelihood of any prostate cancer and clinically significant disease based on a combination of clinical and imaging characteristics. MSP-RC is applicable to all patient settings and accessible online. Crown Copyright (C) 2022 Published by Elsevier B.V. on behalf of European Association of Urology.</p

Characteristics of Tetanic Force Produced by the Sternomastoid Muscle of the Rat

The sternomastoid (SM) muscle plays an important role in supporting breathing. It also has unique anatomical advantages that allow its wide use in head and neck tissue reconstruction and muscle reinnervation. However, little is known about its contractile properties. The experiments were run on rats and designed to determine in vivo the relationship between muscle force (active muscle contraction to electrical stimulation) with passive tension (passive force changing muscle length) and two parameters (intensity and frequency) of electrical stimulation. The threshold current for initiating noticeable muscle contraction was 0.03 mA. Maximal muscle force (0.94 N) was produced by using moderate muscle length/tension (28 mm/0.08 N), 0.2 mA stimulation current, and 150 Hz stimulation frequency. These data are important not only to better understand the contractile properties of the rat SM muscle, but also to provide normative values which are critical to reliably assess the extent of functional recovery following muscle reinnervation

Limb Muscle Reinnervation with the Nerve-Muscle-Endplate Grafting Technique: An Anatomical Feasibility Study

Background. Peroneal nerve injuries results in tibialis anterior (TA) muscle paralysis. TA paralysis could cause “foot drop,” a disabling condition that can make walking difficult. As current treatment methods result in poor functional recovery, novel treatment approaches need to be studied. The aim of this study was to explore anatomical feasibility of limb reinnervation with our recently developed nerve-muscle-endplate grafting (NMEG) in the native motor zone (NMZ). Methods. As the NMEG-NMZ technique involves in nerves and motor endplates (MEPs), the nerve supply patterns and locations of the MEP bands within the gastrocnemius (GM) and TA muscles of rats were investigated using Sihler’s stain and whole-mount acetylcholinesterase (AChE) staining, respectively. Five adult rats underwent TA nerve transaction. The denervated TA was reinnervated by transferring an NMEG pedicle from the ipsilateral lateral GM. At the end of a 3-month recovery period, maximal muscle force was measured to document functional recovery. Results. The results showed that the TA was innervated by the deep peroneal nerve. A single MEP band was located obliquely in the middle of the TA. The GM was composed of two neuromuscular compartments, lateral (GM-l) and medial (GM-m), each of which was innervated by a separate nerve branch derived from the tibial nerve and had a vertically positioned MEP band. The locations of MEP bands in the GM and TA muscles and nerve supply patterns demonstrated that an NMEG pedicle can be harvested from the GM-l and implanted into the NMZ within the TA muscle. The NMEG-NMZ pilot study showed that this technique resulted in optimal muscle force recovery. Conclusion. NMEG-NMZ surgery is feasible for limb reinnervation. Specifically, the denervated TA caused by peroneal nerve injuries can be reinnervated with a NMEG from the GM-l