A Novel Mouse Wound Model for Scar Tissue Formation in Abdominal-Muscle Wall

Scar tissue formation is a result of excess healing reactions after wounding. Hypertrophic scars scarcely develop in a mouse. In the present study, we established a novel experimental model of a scar-forming wound by resecting a small portion of the abdominal wall on the lower center of the abdomen, which exposed contractive forces by the surrounding muscle tissue. As a tension-less control, a back-skin excision model was used with a splint fixed onto the excised skin edge, and granulation tissue formed on the muscle facia supported by the back skeleton. One week after the resection, initial healing reactions such as fibroblast proliferation took place in both models. However, after 21 days, lesions with collagen-rich granulation tissues forming multiple nodular/spherical-like structures developed only in the abdominal-wall model. The lesions are analogous to scar lesions in humans. Such lesions, however, did not develop in the back-skin excision model. Therefore, this animal model is unique in that fibrous scar tissues form under a physiological condition without using any artificial factors and is valuable for studying the pathogenesis and preclinical treatment of scar lesions.

Antifibrotic Effect of Bletilla striata Polysaccharide-Resveratrol-Impregnated Dual-Layer Carboxymethyl Cellulose-Based Sponge for The Prevention of Epidural Fibrosis after Laminectomy

The application of antifibrotic materials can alleviate epidural fibrosis by restricting excessive fibroblast proliferation and mitigating scar tissue formation. Here, a biodegradable carboxymethyl cellulose (CMC)-Bletilla striata polysaccharide (BSP)-resveratrol (RES) sponge was fabricated to inhibit scar tissue formation post laminectomy surgery. Fibroblasts NIH/3T3, myoblasts C2C12, neural cells PC-12, and Schwann cells RSC96 were used to evaluate the in vitro cytocompatibility. Laminectomies on 10 Sprague–Dawley rats with/without the application of the CMC-BSP-RES sponge were performed. The severity of adhesion between the dura mater and formed scar tissue was qualitatively scored. All cell lines exhibited good viability with no significant difference in cytotoxicity when cultured with variable extractions of the CMC-BSP-RES sponge. S100a4 and P4hb expressions were downregulated in NIH/3T3 cultured in the CMC-BSP-RES sponge, implying that this sponge potentially inhibits fibroblast activity. No post-operative shrinkage or dura mater expansion along the surgical site was detected. The peel-off tests revealed that the tenacity of adhesion de-creased. Histopathological examinations verified that the average number of fibroblasts in the CMC-BSP-RES group considerably decreased. The CMC-BSP-RES sponge is a biocompatible and effective material for alleviating post-operative epidural fibrosis and mitigating fibroblast expression following laminectomy.

The Paramedian Forehead Flap: A Retrospective Clinical Model for Understanding the Connection Between Supraorbital and Supratrochlear Nerve Pathology and Headaches

Background: In the later stages of a paramedian forehead flap (PMFF) surgery, the supratrochlear (STN) and branches of the supraorbital nerve (SON) are transected during flap inset above the supraorbital rim. This can lead to either a nerve release if the compression point was previously distal to the transection point or a new nerve compression through neuroma or scar tissue formation. We inferred that PMFF could be a model for understanding the correlation between STN/SON pathology and migraines headaches (MH). We hypothesized that patients undergoing PMFF would experience either a change in severity or an onset of a new headache (HA) or MH. Methods: One hundred ninety-nine patients who underwent a PMFF at a tertiary medical centre were identified and contacted by phone. Patients were asked about the presence of MH or HA before and after the procedure. If a patient reported a perioperative history of MH/HA, their pre- and postoperative MH/HA characteristics were recorded. Results: Of the 199 patients contacted, 74 reported no perioperative HA/MH history and 14 reported a perioperative history of HA/MH. Of these 14 patients, 5 had stable HA/MH pre- and post-surgery, and 9 reported a change in HA/MH post-surgery. In this subset of 9 patients, 3 reported change in HA/MH quality post-surgery, 1 reported HA/MH resolution post-surgery, and 5 reported new onset HA/MH post-surgery. Conclusion: Sixty-four percent of patients with perioperative HA/MH experienced a change in headache quality following surgery. These results suggest a potential connection between SON and STN pathology and HA/MH pathophysiology; further work is warranted.

Experimental Methods to Simulate and Evaluate Postsurgical Peripheral Nerve Scarring

As a consequence of trauma or surgical interventions on peripheral nerves, scar tissue can form, interfering with the capacity of the nerve to regenerate properly. Scar tissue may also lead to traction neuropathies, with functional dysfunction and pain for the patient. The search for effective antiadhesion products to prevent scar tissue formation has, therefore, become an important clinical challenge. In this review, we perform extensive research on the PubMed database, retrieving experimental papers on the prevention of peripheral nerve scarring. Different parameters have been considered and discussed, including the animal and nerve models used and the experimental methods employed to simulate and evaluate scar formation. An overview of the different types of antiadhesion devices and strategies investigated in experimental models is also provided. To successfully evaluate the efficacy of new antiscarring agents, it is necessary to have reliable animal models mimicking the complications of peripheral nerve scarring and also standard and quantitative parameters to evaluate perineural scars. So far, there are no standardized methods used in experimental research, and it is, therefore, difficult to compare the results of the different antiadhesion devices.

Wound Healing Efficacy of Guava Leaf Extract

A wound is a break in the continuity of the skin. The body’s response to injury and the restoration of the same is healing. Wound healing is a biological process that is initiated by trauma and often terminated by scar formation. In this research, guava leaf extract was used as antiseptic and its efficacy was tested to commercially available products. The result revealed that all mice which received guava leaf extract formed scar earlier as compared to povidone iodine and PNSS. Since maturation phase which also refers to remodeling phase is responsible for the new epithelium and final scar tissue formation, and as the development of these completes the complex process of wound healing, the researchers suggest that the use of guava leaf extract in comparison with povidone iodine and PNSS when it comes to wound healing is the most affordable in treatment and promoting normal and more rapid wound healing.

Male coercion and female injury in a sexually cannibalistic mantis

Sexual conflict can generate coercive traits in males that enhance mating success at the expense of female fitness. Pre-copulatory sexual cannibalism—where females consume males without mating—typically favours cautious rather than coercive mating tactics, and few examples of the latter are known. Here, we show that males of the highly cannibalistic springbok mantis, Miomantis caffra , wrestle females during pre-mating interactions. We find that most initial contacts between males and females involve a violent struggle whereby each sex tries be the first to grasp hold of the other with their raptorial forelegs. When females win the struggle, they always cannibalize males. However, when males grasp females first, they dramatically increase the chance of mating. We also find striking evidence that, on some occasions, males wound females with their fore-tibial claws during struggles, resulting in haemolymph loss and scar tissue formation. Taken together, our results show how males can overcome the threat of cannibalism by coercively wrestling females. We argue that pre-copulatory injury in this species is likely to be a negative pleiotropic side-effect of coercive mating behaviour and foraging morphology.

Identifying wound infections for veterinary nurses

Heavily contaminated wounds are a common occurrence in both referral and primary care practice, with traumatic and bite wounds being among the most typical aetiologies seen. Each type of wound can be affected by numerous factors that can inhibit the healing process, one of these major factors is infection. Wound infections and the formation of biofilms can present veterinary nurses with a variety of challenges, which is why it is important that we understand the difference between normal inflammatory signs and the signs of infection. The early identification of infection and biofilms within a wound can influence healing times, scar tissue formation and length of healing. This article aims to highlight the difference between inflammation and infection, the different levels of contamination within a wound, and ways to decipher between superficial and deep tissue infections.