Publications by authors named "Daniel Hellenbrand"

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.

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  • The study investigates the effectiveness of different suturing techniques (non-absorbable nylon, absorbable vicryl, and fibrin glue) in nerve grafting for rats with sciatic nerve injuries.
  • Results show that both vicryl and nylon sutures improved motor function significantly more than controls, with no major differences in nerve recovery overall among the different methods.
  • The findings suggest that vicryl sutures are equally effective as nylon sutures for nerve repair, challenging the previous notion that non-absorbable sutures are superior.
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  • - The study investigates how the position of the sciatic nerve (SN) in relation to the ischial spine (IS) may contribute to deep gluteal syndrome (DGS), a painful condition associated with gluteal neuropathies.
  • - Researchers analyzed MRI scans of 15 surgical patients who had piriformis release and compared them with 30 control patients, finding that the SN was more closely positioned to the IS in those with DGS.
  • - Results indicated that patients who underwent the surgery experienced significant pain relief, suggesting that proper SN-IS alignment could help identify individuals who might benefit from surgical treatment.
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After spinal cord injury, there is an extensive infiltration of immune cells, which exacerbates the injury and leads to further neural degeneration. Therefore, a major aim of current research involves targeting the immune response as a treatment for spinal cord injury. Although much research has been performed analyzing the complex inflammatory process following spinal cord injury, there remain major discrepancies within previous literature regarding the timeline of local cytokine regulation.

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Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials. Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans. As a result, functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.

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Spinal cord injury often results in devastating consequences for those afflicted, with very few therapeutic options. A central element of spinal cord injuries is astrogliosis, which forms a glial scar that inhibits neuronal regeneration post-injury. Chondroitinase ABC (ChABC) is an enzyme capable of degrading chondroitin sulfate proteoglycan (CSPG), the predominant extracellular matrix component of the glial scar.

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Article Synopsis
  • Traumatic spinal cord injury (SCI) leads to significant loss of motor and sensory functions, with current treatments failing to ensure meaningful recovery.
  • The injury causes immediate damage and initiates a harmful cascade involving ischemia and inflammation that can last over six months.
  • This review assesses immune responses and cytokine actions in rodent models, underscoring the need to better understand the underlying mechanisms of secondary injury to develop effective therapeutic strategies.
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Background: Posterior interosseous nerve palsy (PINP) is a disorder caused by damage to the posterior interosseous nerve, resulting in weak extension of the wrist and fingers as well as radial deviation of the wrist.

Methods: This study analyzed a new type of evaluation for PINP in hopes of increasing ease of diagnosis and earlier detection of the disorder. The window test is performed by the examiner laying hands on the ulnar aspect of the patient's pronated forearm while the patient tries to extend the wrist.

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Brachial plexus injury (BPI) occurs when the brachial plexus is compressed, stretched, or avulsed. Although rodents are commonly used to study BPI, these models poorly mimic human BPI due to the discrepancy in size. The objective of this study was to compare the brachial plexus between human and Wisconsin Miniature Swine (WMS ), which are approximately the weight of an average human (68-91 kg), to determine if swine would be a suitable model for studying BPI mechanisms and treatments.

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The gold standard for treating peripheral nerve injuries that have large nerve gaps where the nerves cannot be directly sutured back together because it creates tension on the nerve, is to incorporate an autologous nerve graft. However, even with the incorporation of a nerve graft, generally patients only regain a small portion of function in limbs affected by the injury. Although, there has been some promising results using growth factors to induce more axon growth through the nerve graft, many of these previous therapies are limited in their ability to release growth factors in a sustained manner and tailor them to a desired time frame.

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Background: The anti-inflammatory cytokine interleukin-10 (IL-10) has been explored previously as a treatment method for spinal cord injury (SCI) due to its ability to attenuate pro-inflammatory cytokines and reduce apoptosis. Primary limitations when using systemic injections of IL-10 are that it is rapidly cleared from the injury site and that it does not cross the blood-spinal cord barrier.

Objective: Here, mineral-coated microparticles (MCMs) were used to obtain a local sustained delivery of IL-10 directly into the injury site after SCI.

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Rats have been the primary model to study the process and underlying mechanisms of recovery after spinal cord injury. Two weeks after a severe spinal cord contusion, rats can regain weight-bearing abilities without therapeutic interventions, as assessed by the Basso, Beattie and Bresnahan locomotor scale. However, many human patients suffer from permanent loss of motor function following spinal cord injury.

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Spinal cord injury (SCI) is a devastating condition affecting 270,000 people in the United States. The use of growth factors is a potential treatment for reducing secondary damage, promoting axon growth, and restoring some of the lost function post-SCI. Glial cell line-derived neurotrophic factor (GDNF) is an important growth factor, because it can affect both neurons and support cells.

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Objective: Autologous peripheral nerve grafts are commonly used clinically as a treatment for peripheral nerve injuries. However, in research using an autologous graft is not always feasible due to loss of function, which in many cases is assessed to determine the efficacy of the peripheral nerve graft. In addition, using allografts for research require the use of an immunosuppressant, which creates unwanted side effects and another variable within the experiment that can affect regeneration.

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Because of the dynamics of spinal cord injury (SCI), the optimal treatment will almost certainly be a combination approach to control the environment and promote axonal growth. This study uses peripheral nerve grafts (PNGs) as scaffolds for axonal growth while delivering neurotrophin-3 (NT-3) via calcium phosphate (CaP) coatings on surgical sutures. CaP coating was grown on sutures, and NT-3 binding and release were characterized in vitro.

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The regeneration of axons after a spinal cord injury or disease is attracting a significant amount of interest among researchers. Being able to assess these axons in terms of morphology, length and origin is essential to our understanding of the regeneration process. Recently, two specific axon tracers have gained much recognition; biotinylated dextran amine (BDA) 10 kDa as an anterograde tracer and cholera toxin-B as a retrograde tracer.

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Spinal cord injury (SCI) is a devastating condition affecting 270,000 people in the United States. A potential treatment for decreasing the secondary inflammation, excitotoxic damage, and neuronal apoptosis associated with SCI, is the anti-inflammatory cytokine interleukin-10. The best characterized effects of IL-10 are anti-inflammatory-it downregulates pro-inflammatory species interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor-α, interferon-γ, matrix metalloproteinase-9, nitric oxide synthase, myeloperoxidase, and reactive oxygen species.

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