bromochloroacetic-acid and Spinal-Cord-Injuries

Laboratory study using a rat T9 contusion model of spinal cord injury (SCI).. The purpose of this study was to evaluate which method of delivery of soluble keratin biomaterials would best support functional restoration through the macrophage polarization paradigm.. SCI is a devastating neurologic event with complex pathophysiological mechanisms that currently has no cure. After injury, macrophages and resident microglia are key regulators of inflammation and tissue repair exhibiting phenotypic and functional plasticity. Keratin biomaterials have been demonstrated to influence macrophage polarization and promote the M2 anti-inflammatory phenotype that attenuates inflammatory responses.. Anesthetized female Lewis rats were subjected to moderate T9 contusion SCI and randomly divided into: no therapy (control group), an intrathecally injected keratin group, and a keratin-soaked sponge group (n = 11 in all groups). Functional recovery assessments were obtained at 3- and 6-weeks post-injury (WPI) using gait analysis performed with the DigiGait Imaging System treadmill and at 1, 3, 7, 14, 21, 28, 35, and 42 days post-injury by the Basso, Beattie, Bresnahan (BBB) locomotor rating scale. Histology and immunohistochemistry of serial spinal cord sections were performed to assess injury severity and treatment efficacy.. Compared to control rats, applying keratin materials after injury improved functional recovery in certain gait parameters and overall trended toward significance in BBB scores; however, no significant differences were observed with tissue analysis between groups at 6 WPI.. Results suggest that keratin biomaterials support some locomotor functional recovery and may alter the acute inflammatory response by inducing macrophage polarization following SCI. This therapy warrants further investigation into treatment of SCI.Level of Evidence: N/A.

Topics: Animals; Biocompatible Materials; Disease Models, Animal; Female; Keratins; Rats; Rats, Inbred Lew; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord; Spinal Cord Injuries

After spinal cord transection, lampreys recover functionally and axons regenerate. It is not known whether this is accompanied by neurogenesis. Previous studies suggested a baseline level of nonneuronal cell proliferation in the spinal cord and rhombencephalon (where most supraspinal projecting neurons are located). To determine whether cell proliferation increases after injury and whether this includes neurogenesis, larval lampreys were spinally transected and injected with 5-bromo-2&prime-deoxyuridine (BrdU) at 0-3 weeks posttransection. Labeled cells were counted in the lesion site, within 0.5 mm rostral and caudal to the lesion, and in the rhombencephalon. One group of animals was processed in the winter and a second group was processed in the summer. The number of labeled cells was greater in winter than in summer. The lesion site had the most BrdU labeling at all times, correlating with an increase in the number of cells. In the adjacent spinal cord, the percentage of BrdU labeling was higher in the ependymal than in nonependymal regions. This was also true in the rhombencephalon but only in summer. In winter, BrdU labeling was seen primarily in the subventricular and peripheral zones. Some BrdU-labeled cells were also double labeled by antibodies to glial-specific (antikeratin) as well as neuron-specific (anti-Hu) antigens, indicating that both gliogenesis and neurogenesis occurred after spinal cord transection. However, the new neurons were restricted to the ependymal zone, were never labeled by antineurofilament antibodies, and never migrated away from the ependyma even at 5 weeks after BrdU injection. They would appear to be cerebrospinal fluid-contacting neurons.

Topics: Animals; Bromodeoxyuridine; Cell Proliferation; Central Nervous System; Keratins; Lampreys; Nerve Tissue Proteins; Neurogenesis; Spinal Cord Injuries

In contrast to mammals, the spinal cord of lampreys spontaneously recovers from a complete spinal cord injury (SCI). Understanding the differences between lampreys and mammals in their response to SCI could provide valuable information to propose new therapies. Unique properties of the astrocytes of lampreys probably contribute to the success of spinal cord regeneration. The main aim of our study was to investigate, in the sea lamprey, the release of aminoacidergic neurotransmitters and the subsequent astrocyte uptake of these neurotransmitters during the first week following a complete SCI by detecting glutamate, GABA, glycine, Hu and cytokeratin immunoreactivities. This is the first time that aminoacidergic neurotransmitter release from neurons and the subsequent astrocytic response after SCI are analysed by immunocytochemistry in any vertebrate. Spinal injury caused the immediate loss of glutamate, GABA and glycine immunoreactivities in neurons close to the lesion site (except for the cerebrospinal fluid-contacting GABA cells). Only after SCI, astrocytes showed glutamate, GABA and glycine immunoreactivity. Treatment with an inhibitor of glutamate transporters (DL-TBOA) showed that neuronal glutamate was actively transported into astrocytes after SCI. Moreover, after SCI, a massive accumulation of inhibitory neurotransmitters around some reticulospinal axons was observed. Presence of GABA accumulation significantly correlated with a higher survival ability of these neurons. Our data show that, in contrast to mammals, astrocytes of lampreys have a high capacity to actively uptake glutamate after SCI. GABA may play a protective role that could explain the higher regenerative and survival ability of specific descending neurons of lampreys.

Topics: Animals; Astrocytes; Axons; Fish Proteins; Fluorescent Antibody Technique; gamma-Aminobutyric Acid; Glutamic Acid; Glycine; Immunohistochemistry; Keratins; Lampreys; Microscopy, Confocal; Neurons; Neurotransmitter Agents; Photomicrography; Spinal Cord Injuries; Spinal Cord Regeneration; Time Factors

Secondary degeneration leads to an expansion of the initial tissue damage sustained during a spinal cord injury (SCI). Dampening the cellular inflammatory response that contributes to this progressive tissue damage is one possible strategy for neuroprotection after acute SCI. We initially examined whether treatment with a PEGylated form of rat interferon-beta (IFN-beta) would modulate the expression of several markers of inflammation and neuroprotection at the site of a unilateral cervical level 5 contusion injury. Adult female Sprague-Dawley rats were injured using the Infinite Horizon Impactor at a force of 200 kdyn (equivalent to a severe injury) and a mean displacement of 1600-1800 mum. A single dose (5x10(6) units) of PEGylated IFN-beta or vehicle was administered 30 min following SCI. Here we demonstrate temporal changes in pro- and anti-inflammatory cytokine levels and the expression of heat shock proteins and iNOS (involved in neuroprotection) at the lesion epicenter and one segment caudally after SCI and PEG IFN-beta treatment. The results suggested a potential therapeutic treatment strategy for modulation of secondary damage after acute SCI. Therefore, we examined whether acute treatment with PEG IFN-beta would improve forelimb function alone or when combined with forced exercise (Ex). Animals began the Ex paradigm 5 days post SCI and continued for 5 days/week over 8 weeks. Locomotion (forelimb locomotor scale [FLS], hindlimb BBB, and TreadScan) and sensorimotor function (grid walking) was tested weekly. Additional outcome measures included lesion size and glial cell reactivity. Significant FLS improvements occurred at 1 week post SCI in the PEGylated IFN-beta-treated group but not at any other time point or with any other treatment approaches. These results suggest that this acute neuroprotective treatment strategy does not translate into long term behavioral recovery even when combined with forced exercise.

Topics: Acute Disease; Animals; Cervical Vertebrae; Combined Modality Therapy; Exercise Therapy; Female; Forelimb; Interferon-beta; Keratins; Locomotion; Myelitis; Neuroprotective Agents; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord Injuries

To investigate the changes of oligodendrocyte proliferation and differentiation in response to implantation of degradable human hair keratin (HHK) into the spinal cord with acute injury in adult rats.. Rat models of acute spinal cord injury were established by direct impact of the exposed spinal cord with a weight-dropping device, 12 of which received immediate HHK implant into the injured spinal cord. The rats of control injury group (n=12) were subjected to the injury but did not receive subsequent implant, and those in sham operation group (n=12) only had the spinal cord exposure without injury. Another 8 rats were used as the normal control group. Samples of the spinal cord were obtained 1, 4, 12, and 26 weeks respectively after the operations and serial sections were prepared for examination with light and electron microscope.. One week after the injury, few oligodendrocytes were observed among the large number of the infiltrating leukocytes in the injured spinal cord with HHK implants. Staining with hematoxylin eosin and Mallory's phosphotungstic acid-hematoxylin at the fourth week revealed oligodendrocyte proliferation around the HHK implant. The period from the 12th to 26th week was characterized by nerve regeneration and myelin sheath reconstruction, in the course of which empty cavity occurred within the sheath of the oligodendrocytes, and lamellar separation of the myelin sheath were observed. Phagocytized myelin sheath and axone fragment were detected in oligodendrocytes, with the newly generated oligodendrocytes scattering abound the rebuilt myelin sheath.. HHK can be beneficial for the proliferation and differentiation of oligodendrocytes and myelin sheath rebuilding and repair in the course of neuronal regeneration after acute spinal cord injury.

Topics: Animals; Cell Differentiation; Cell Division; Female; Hair; Humans; Keratins; Nerve Regeneration; Oligodendroglia; Prostheses and Implants; Rats; Rats, Sprague-Dawley; Spinal Cord Injuries

A prospective, immunohistochemical study of bladder biopsies taken from spinal cord injury (SCI) patients.. To investigate whether cytokeratin 14 immunostaining may be useful to detect early squamous metaplasia in bladder biopsies from patients with SCI.. Southport, United Kingdom.. Biopsy of bladder mucosa was taken from adults with SCI, while they underwent an elective therapeutic procedure in the urinary tract. A total of, 54 biopsies, which showed transitional epithelium only with no evidence of squamous metaplasia on routine H&E staining, formed the study group. In all, 22 biopsies, which showed squamous metaplasia on routine H&E staining, acted as controls. All biopsies were benign with no evidence of dysplasia or malignancy. Immunohistochemical staining for cytokeratin 14 was performed on all biopsies in a single batch, using a standard avidin-biotin complex method.. All control biopsies showed positive immunostaining for cytokeratin 14 in basal and parabasal cells in areas of squamous metaplasia. Of the 54 biopsies, which showed only transitional epithelium on H&E staining, immunohistochemistry for cytokeratin 14 showed no staining in 47 biopsies. The remaining seven biopsies showed positive immunostaining for cytokeratin 14 in the epithelium, in individual cells or clusters of basal cells, revealing unexpected early squamous metaplasia in these biopsies.. Immunostaining for cytokeratin 14 identifies an early phenotypic switch from transitional to squamous epithelium in bladder mucosa. Cytokeratin 14 staining is sufficiently sensitive to identify early squamous metaplasia, which is not yet evident on examination of routine H&E stained sections. This early identification may be of use in alerting physicians to change bladder management regimens to prevent predisposition to recurrent urinary infection and progression of squamous metaplasia. A cost/benefit analysis should be performed to assess the feasibility of routine cytokeratin 14 immunostaining of bladder biopsies from SCI patients.

Topics: Animals; Biopsy; Humans; Keratin-14; Keratins; Metaplasia; Mice; Prospective Studies; Spinal Cord Injuries; Urinary Bladder