Guinea pigs as an animal model for sciatic nerve injury

Mesenchymal stem cells derived from bone marrow and adipose tissue for repairing acute sciatic nerve injury in a rabbit model

Peripheral nerve injury is one of the common disabling clinical conditions and around 50% of the cases end up in permanent impairment. Due to the lack of effective treatment options regenerative medicine employing stem cells is being evaluated. The presented study evaluated and compared regeneration potential of mesenchymal stem cells (MSCs) derived from bone marrow (BM) and adipose tissue (AD) in acute rabbit sciatic nerve injury (axonotmesis) model. A total of n = 54 grey giant rabbits were made subject of the study and divided equally into 3 groups: Control, BM-MSCs in Collagen I and AD-MSCs in Collagen I as per the treatment given. Iliac crest BM and omental AD was harvested from the same donor for isolation and culture of MSCs. The repair of sciatic nerve injury was evaluated on days 60 and 90. The clinical and histopathological scores and SEM morphology was better in cell treated groups as compared to the control. Morphology and histological studies revealed injured nerve in different levels of regenerative process. Gene expression was more than double for N-Cadherin in cell treated groups as compared to the control, especially at day 60. Between cell treated groups, BM-MSCs group showed better response as compared to the AD-MSCs, although statistically non-significant (p > 0.05). Incomplete nerve regeneration observed under various diagnostic parameters was in compliance to the incomplete clinical recovery at day 90. It was concluded that MSCs may improve sciatic nerve healing but fall short of complete regeneration at day 90, although BM-MSCs may have an edge over AD-MSCs.

Effect of vitamin B complex administration on pain and sensory problems related to inferior alveolar nerve damage following mandibular implant placement surgery

Background. Inferior alveolar nerve damage can lead to mild to severe paresthesia and even facial pain. One of the treatments considered today for the reconstruction and treatment of damaged peripheral nerves is the use of vitamin supplements. This study aimed to evaluate the effect of vitamin B complex supplementation on pain and sensory problems following mandibular implant placement surgery. Methods. In this single-blind clinical trial, 46 patients applying for implant placement, who were eligible for the study, were evaluated. All the patients were examined for sensory facial injury and inferior alveolar nerve injury within 24 hours after implant placement. The nerve damage was recorded by AI (asymmetry index) in the initial examination. Patients who reported clinical and radiographic signs of nerve damage due to implant or drill impingement of the nerve canal were excluded from the study and promptly treated with anti-inflammatory protocols. Then the patients were randomly divided into control (n=23) and intervention (n=23) groups. Patients in the control group received routine treatment after implantation, and patients in the intervention group received vitamin B complex pills in addition to routine treatment. A placebo was used to eliminate the inductive effect of the drug in the control group. Follow-up of patients was performed at intervals of 14 days and 1, 2, and 3 months after treatment. Data analysis was performed using SPSS 24 and Kruskal-Wallis, Wilcoxon, and chi-squared tests. Results. In both groups, a decreasing trend in pain intensity was observed for up to three months. There were no significant differences between the mean pain intensity in the intervention and control groups at all the follow-up intervals. In both groups, a decrease in the rate of paresthesia was observed during the 3-month follow-up. The mean of paresthesia in the two groups was not significantly different at any follow-up interval. Conclusion. Vitamin B complex might not affect pain intensity and paresthesia after implant surgery.

A guide to reducing adverse outcomes in rabbit models of sciatic nerve injury

Background

Peripheral nerve damage can have debilitating consequences. Rabbit sciatic nerve transection models allow the effective evaluation of surgical repair strategies for large nerve gaps. Despite advantages in size, ease of handling, and functional utility, rabbits can suffer from a number of side effects that affect animal welfare and the quality of scientific inquiry. Such side-effects, which include pressure ulcers and traumatic damage to the foot, are primarily a consequence of insensitivity of the distal hindlimb following sciatic nerve injury. In this study, we present a number of methodologies for identifying, treating, and preventing unintended adverse effects in rabbit sciatic nerve injury models.

Results

First, we categorize pressure ulcers according to their severity and describe the deployment of a padded bandaging technique to enable ulcer healing. We also introduce a proactive bandaging approach to reduce the likelihood of pressure ulcer formation. Second, we define phenotypes that distinguish between foot injuries resulting from self-mutilation (autotomy) from those caused by incidental traumatic injury secondary to sensori-motor damage. Finally, we detail an effective strategy to reduce the usage of Elizabethan collars; through a gradual weaning protocol, their usefulness in preventing autotomy is retained, while their propensity to impede rabbit grooming and cause abrasion-injury to the neck region is minimized.

Conclusions

We suggest that application of these methods offer a practical and systematic approach to avoid adverse side effects associated with rabbit sciatic nerve damage, enabling improved animal welfare and scientific outcomes in a powerful nerve injury model.

Sciatic nerve injury model in rabbits: What to expect

Rabbits are commonly used for sciatic nerve injuries larger than 1.5 cm. This report provides insight into risks and benefits associated with using rabbit models in sciatic nerve injury models and proposes interventions that researchers can use to prevent experimental complications. Fifty-six rabbits from a sciatic nerve injury study that involved a 40 mm sciatic nerve injury were analyzed to examine postoperative complication rates. Autophagy of the phalanges and plantar pressure ulcer development were the most common and serious complications faced. These complications led to 23.2% (n = 13) of rabbits not being used for data in the original experiment due to euthanasia outside of intended postoperative time points. This increased the cost needed to complete the experiment by $25,038.44. It is our recommendation that alternative models be used instead of rabbits for sciatic nerve injuries. If rabbits must be used, a treatment protocol for preventing autophagy and pressure ulcers is outlined below.