Spinal cord injury (SCI) often results in permanent loss of motor and sensory function. After SCI, the blood–spinal cord barrier (BSCB) is disrupted, causing the infiltration of neutrophils and macrophages, which secrete several kinds of cytokines, as well as matrix metalloproteinases (MMPs). MMPs are proteases capable of degrading various extracellular matrix (ECM) proteins, as well as many non-matrix substrates. The tissue inhibitor of MMPs (TIMP)-1 is significantly upregulated post-SCI and operates via MMP-dependent and MMP-independent pathways. Through the MMP-dependent pathway, TIMP-1 directly reduces inflammation and destruction of the ECM by binding and blocking the catalytic domains of MMPs. Thus, TIMP-1 helps preserve the BSCB and reduces immune cell infiltration. The MMP-independent pathway involves TIMP-1’s cytokine-like functions, in which it binds specific TIMP surface receptors. Through receptor binding, TIMP-1 can stimulate the proliferation of several types of cells, including keratinocytes, aortic smooth muscle cells, skin epithelial cells, corneal epithelial cells, and astrocytes. TIMP-1 induces astrocyte proliferation, modulates microglia activation, and increases myelination and neurite extension in the central nervous system (CNS). In addition, TIMP-1 also regulates apoptosis and promotes cell survival through direct signaling. This review provides a comprehensive assessment of TIMP-1, specifically regarding its contribution to inflammation, ECM remodeling, and scar formation after SCI.

Basal cell carcinoma (BCC) occurrences in the conjunctiva are exceptionally rare. These lesions become exceedingly rarer next to an adjacent area of squamous cell carcinoma. A collision tumor of both basal cell and squamous cell carcinoma is infrequently encountered in the literature. An elderly male patient was evaluated for concern of ocular surface squamous neoplasia on his left conjunctiva. The lesion appeared as a tan-white elevated lesion with atypical vessels in papillary fronds. The patient underwent surgical excision of the lesion, and the tissue was sent to ocular pathology for histopathologic evaluation. The final diagnosis was basal cell carcinoma and squamous cell carcinoma. The two tumors of both basal cell carcinoma and squamous cell carcinoma were juxtaposed with an abrupt transition zone with no fluidity of differentiation. The lesion had typical features for BCC with positive stain for Bcl-2, P63, P53, CD10, and BerEP4. Additionally, the SCC region stained positive for EMA, P63, and P53. We report a single lesion of the conjunctiva with features of both basal cell carcinoma and squamous cell carcinoma. This case report describes a unique case of two independent neoplasms of the conjunctiva. This further adds to the literature of collision tumors to characterize the lesion with appropriate immunohistochemical analysis.

Background: Proximal sciatic nerve injuries are a challenge to treat due to the limited options for donor nerves and the long distance needed for regeneration. Methods: In our cadaveric study using five human cadavers, we aimed to evaluate the feasibility of transferring the tibial and common peroneal components of the sciatic nerve to the femoral nerve motor branches of the vastus medialis (VM) and vastus lateralis without the need for interposition nerve graft. The femoral nerve branches of the VM and lateralis were exposed anteriorly. The sciatic nerve was exposed posteriorly and passed through a narrow window within the adductor magnus and medial to the femur. The sciatic nerve was then separated into its tibial and peroneal components, which were then coapted to the VM and lateralis motor branches of the femoral nerve. Results: Using the entire tibial and peroneal components of the sciatic nerve, we were able to gain more length and directly coapt the femoral nerve branches without utilizing interposition grafts. The disadvantage of this technique is suturing to a mixed nerve with motor and sensory components, which could compromise functional outcomes. Further studies are needed to determine how the procedure will impact a patient’s gait cycle. Conclusion: Clinical application is needed to determine preliminary outcomes before widespread utilization of this technique.