Calcaneal Tendon Plasticity Following Gastrocnemius Muscle Injury in Rat

Identification of optimal surgical plan for treatment of extraocular muscle damage in thyroid eye disease patients based on computational biomechanics

This study replicated the behavior of intraorbital tissue in patients with thyroid eye disease (TED) based on finite element analysis for general orbital decompression risk evaluation in thyroid eye disease patients. The orbit and intraorbital tissues of thyroid eye disease patients who underwent orbital decompression were modeled as finite element models. The stress was examined at specific locations of the removed orbital wall of a thyroid eye disease patient with undergone orbital decompression, and its variation was analyzed as a function of the shape and dimension (to be removed). As a result, in orbital decompression surgery which removes the orbital wall in a rectangular shape, the stress at the orbital wall decreased as the width and depth of the removed orbital wall increased. In addition, in the case of orbital decompression, it can be seen that the chamfered model compared to the non-chamfered model (a form of general orbital decompression) have the stress reduction rate from 11.08% to 97.88%. It is inferred that if orbital decompression surgery considering the chamfered model is performed on an actual thyroid eye disease patient, it is expected that the damage to the extraocular muscle caused by the removed orbital wall will be reduced.

Is contralateral autogenous patellar tendon graft a better choice than ipsilateral for anterior cruciate ligament reconstruction in young sportsmen? A randomized controlled trial

AIM

The aim of this study was to compare the peak extensor torque (primary outcome), sensory-motor capacity and Lysholm questionnaire score up to the fourth postoperative month post-primary anterior cruciate ligament reconstruction (ACLR) with bone-patellar-tendon-bone (BPTB) graft using either ipsilateral or contralateral technique in young sportsmen.

METHODS

We performed a randomized controlled trial from 2018 to 2019. The same preoperative protocol, surgical technique and postoperative protocol were used in both groups. Eighty-eight young adult male patients were randomized, and 44 of each group completed the trial.

RESULTS

After the follow up analysis, the contralateral receptor and donor limb demonstrated a statistically significant increase in peak extension torque compared with the ipsilateral operated limb (effect size (ES) = 0.99, power = 0.99, P < 0.0001; ES = 0.46, power = 0.56, P < 0.04). The symmetry between limbs was compared between groups. In the contralateral group, there was a significant decrease in the recipient limb (after surgery), compared with the donor limb (before surgery) (ES = 0.87, power = 0.99, P < 0.0001). In the ipsilateral group, the operated limb demonstrated a significant decrease in peak extension torque compared with the non-operated limb after surgery (ES = 1.88, power = 0.99, P < 0.0001). The comparison between groups in sensory-motor capacity and Lysholm score demonstrated a non-significant group effect postoperatively.

CONCLUSION

The use of contralateral BPTB is more effective in increasing peak extension torque when compared with ipsilateral technique in young sportsmen. Furthermore, patients achieved greater symmetry (side to side) in quadriceps muscle performance after the 4-month follow up with a contralateral graft.

Paternal Resistance Exercise Modulates Skeletal Muscle Remodeling Pathways in Fathers and Male Offspring Submitted to a High-Fat Diet

Although some studies have shown that a high-fat diet (HFD) adversely affects muscle extracellular matrix remodeling, the mechanisms involved in muscle trophism, inflammation, and adipogenesis have not been fully investigated. Thus, we investigated the effects of 8 weeks of paternal resistance training (RT) on gene and protein expression/activity of critical factors involved in muscle inflammation and remodeling of fathers and offspring (offspring exposed to standard chow or HFD). Animals were randomly distributed to constitute sedentary fathers (SF; n = 7; did not perform RT) or trained fathers (TF n = 7; performed RT), with offspring from mating with sedentary females. After birth, 28 male pups were divided into four groups (n = 7 per group): offspring from sedentary father submitted either to control diet (SFO-C) or high-fat diet (SFO-HF) and offspring from trained father submitted to control diet (TFO-C) or high-fat diet (TFO-HF). Our results show that an HFD downregulated collagen mRNA levels and upregulated inflammatory and atrophy pathways and adipogenic transcription factor mRNA levels in offspring gastrocnemius muscle. In contrast, paternal RT increased MMP-2 activity and decreased IL-6 levels in offspring exposed to a control diet. Paternal RT upregulated P70s6k and Ppara mRNA levels and downregulated Atrogin1 mRNA levels, while decreasing NFκ-B, IL-1β, and IL-8 protein levels in offspring exposed to an HFD. Paternal physical training influences key skeletal muscle remodeling pathways and inflammatory profiles relevant for muscle homeostasis maintenance in offspring submitted to different diets.

Extracellular matrix at the muscle - tendon interface: functional roles, techniques to explore and implications for regenerative medicine

The muscle-tendon interface is an anatomically specialized region that is involved in the efficient transmission of force from muscle to tendon. Due to constant exposure to loading, the interface is susceptible to injury. Current treatment methods do not meet the socioeconomic demands of reduced recovery time without compromising the risk of reinjury, requiring the need for developing alternative strategies. The extracellular matrix (ECM) present in muscle, tendon, and at the interface of these tissues consists of unique molecules that play significant roles in homeostasis and repair. Better, understanding the function of the ECM during development, injury, and aging has the potential to unearth critical missing information that is essential for accelerating the repair at the muscle-tendon interface. Recently, advanced techniques have emerged to explore the ECM for identifying specific roles in musculoskeletal biology. Simultaneously, there is a tremendous increase in the scope for regenerative medicine strategies to address the current clinical deficiencies. Advancements in ECM research can be coupled with the latest regenerative medicine techniques to develop next generation therapies that harness ECM for treating defects at the muscle-tendon interface. The current work provides a comprehensive review on the role of muscle and tendon ECM to provide insights about the role of ECM in the muscle-tendon interface and discusses the latest research techniques to explore the ECM to gathered information for developing regenerative medicine strategies.

Paternal Resistance Training Modulates Calcaneal Tendon Proteome in the Offspring Exposed to High-Fat Diet

The increase in high-energy dietary intakes is a well-known risk factor for many diseases, and can also negatively impact the tendon. Ancestral lifestyle can mitigate the metabolic harmful effects of offspring exposed to high-fat diet (HF). However, the influence of paternal exercise on molecular pathways associated to offspring tendon remodeling remains to be determined. We investigated the effects of 8 weeks of paternal resistance training (RT) on offspring tendon proteome exposed to standard diet or HF diet. Wistar rats were randomly divided into two groups: sedentary fathers and trained fathers (8 weeks, three times per week, with 8–12 dynamic movements per climb in a stair climbing apparatus). The offspring were obtained by mating with sedentary females. Upon weaning, male offspring were divided into four groups (five animals per group): offspring from sedentary fathers were exposed either to control diet (SFO-C), or to high-fat diet (SFO-HF); offspring from trained fathers were exposed to control diet (TFO-C) or to a high-fat diet (TFO-HF). The Nano-LC-MS/MS analysis revealed 383 regulated proteins among offspring groups. HF diet induced a decrease of abundance in tendon proteins related to extracellular matrix organization, transport, immune response and translation. On the other hand, the changes in the offspring tendon proteome in response to paternal RT were more pronounced when the offspring were exposed to HF diet, resulting in positive regulation of proteins essential for the maintenance of tendon integrity. Most of the modulated proteins are associated to biological pathways related to tendon protection and damage recovery, such as extracellular matrix organization and transport. The present study demonstrated that the father’s lifestyle could be crucial for tendon homeostasis in the first generation. Our results provide important insights into the molecular mechanisms involved in paternal intergenerational effects and potential protective outcomes of paternal RT.