secondary degeneration
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Author(s):  
Mayuri K. Wanjari ◽  
Rebecca Timothy ◽  
Suchitra Menon ◽  
Rakesh Krishna Kovela ◽  
Mohammad Irshad Qureshi ◽  
...  

Background: Despite the most significant efforts of many experts to provide natural therapeutic therapies, spinal cord injury (SCI) is a traumatic event with limited functional recovery. After a spinal cord injury, paraplegia can develop. Damage to the ligaments, vertebrae, or discs of the spinal column causes this. Paraplegia is the loss of muscle function in the lower half of the body, including both legs. Leg paralysis, in this case in which affects all parts of the pelvic organs, legs, and torso. This is partly owing to the complex character of SCI, which involves a great deal of disarray and malfunction as a result of the initial injury. Secondary degeneration is caused by neurotoxicity, vascular malfunction, neuroinflammation, apoptosis, and demyelination. Presentation of Case: 34year old male patient with wedge compression was diagnosed on x-ray after a fall from the tree. Discussion: The requirements for regeneration, rehabilitation, and neuroprotection appear to necessitate a diverse set of therapeutic approaches that can be used at different stages of the post-injury response. Conclusion: We'll focus on one strategy, in particular, physical training/exercise, which looks to have a wide range of applications and benefits for those with a chronic or acute SCI.


2021 ◽  
Author(s):  
Artemis Zavaliangos-Petropulu ◽  
Bethany Lo ◽  
Miranda R Donnelly ◽  
Nicolas Schweighofer ◽  
Keith Lohse ◽  
...  

Persistent sensorimotor impairments after stroke can negatively impact quality of life. The hippocampus is involved in sensorimotor behavior but has not been widely studied within the context of post-stroke upper limb sensorimotor impairment. The hippocampus is vulnerable to secondary degeneration after stroke, and damage to this region could further weaken sensorimotor circuits, leading to greater chronic sensorimotor impairment. The purpose of this study was to investigate the cross-sectional association between non-lesioned hippocampal volume and upper limb sensorimotor impairment in people with chronic stroke. We hypothesized that smaller ipsilesional hippocampal volumes would be associated with worse upper-limb sensorimotor impairment. Cross-sectional T1-weighted brain MRIs were pooled from 357 participants at the chronic stage after stroke (>180 days post-stroke) compiled from 18 research cohorts worldwide in the ENIGMA Stroke Recovery Working Group (age: median = 61 years, interquartile range = 18, range = 23-93; 135 women and 222 men). Sensorimotor impairment was estimated from the Fugl-Meyer Assessment of Upper Extremity scores. Robust mixed-effects linear models were used to test associations between post-stroke sensorimotor impairment and hippocampal volumes (ipsilesional and contralesional separately; Bonferroni-corrected, p-value < 0.025), controlling for age, sex, lesion volume, and lesioned hemisphere. We also performed an exploratory analysis to test whether sex differences influence the relationship between sensorimotor impairment and hippocampal volume. Upper limb sensorimotor impairment was positively associated with ipsilesional (p = 0.005; d = 0.33) but not contralesional (p = 0.96; d = 0.01) hippocampal volume, such that impairment was worse for participants with smaller ipsilesional hippocampal volume. This association remained significant independent of lesion volume or other covariates (p = 0.001; d = 0.36). Evidence indicates an interaction between sensorimotor impairment and sex for both ipsilesional (p = 0.008; d = -0.29) and contralesional (p = 0.006; d = -0.30) hippocampal volumes, whereby women showed progressively worsening sensorimotor impairment with smaller hippocampal volumes compared to men. The present study has identified a novel association between chronic post-stroke sensorimotor impairment and ipsilesional, but not contralesional, hippocampal volume. This finding was not due to lesion size and may be stronger in women. We also provide supporting evidence that smaller hippocampal volume post-stroke is likely a consequence of ipsilesional damage, which could provide a link between vascular disease and other disorders, such as dementia.


2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Andrea Paola Ibarra-García ◽  
Antonio Ibarra

Spinal cord injury (SCI) induces several destructive events that develop immediately after the primary insult. These phenomena increase tissue damage; that is why, numerous therapeutic approaches are studied in order to neutralize these destructive mechanisms. In line with this, several studies indicate that after injury, neural tissue could be protected by an adaptive immune response directed against self-antigens. Immunization with neural-derived peptides (INDP) reduces secondary degeneration of neurons after spinal cord insult and promotes a significant motor recovery. The combination of antioxidants or other immunomodulatory peptides after SCI can improve the protective effect induced by INDP. INDP in acute SCI is a promising strategy, so further studies should be addressed to be able to formulate the best strategy.


2021 ◽  
pp. 628-633
Author(s):  
Sohyeon Kim ◽  
Sung-Il Sohn ◽  
Hyungjong Park ◽  
JoonSik Kim ◽  
Jeong-Ho Hong

Cerebral infarction is known to cause secondary degeneration of the areas connected to the primarily damaged regions. This has been named as acute network injury and is usually recognized in newborns or babies by high signal intensity on diffusion-weighted imaging (DWI). In this article, we present 2 cases demonstrating several characteristics of network injury. Some features are comparable to previous studies and others are distinctive to our cases. The patients not only showed secondary injury in the thorough pyramidal tract along the longitudinal extensions of neural tracts as expected but also followed transverse connections to reach the contralateral hemisphere. The location of network injury varied according to the initial lesion and projected in an omnidirectional manner as long as the brain parts are interconnected. In addition, the cases well demonstrated the temporal changes on brain imaging. Network injury appeared on DWI around a week after major damage and then subsequently disappeared. The overall process of appearance to disappearance was completed within 2 weeks from the symptom onset. As ominous neurological outcomes are thought to be related to acute network injuries, a comprehensive understanding of the phenomenon is pivotal in improving diagnosis and management.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
So-Young Chang ◽  
Hee-Won Jeong ◽  
Eunjeong Kim ◽  
Jae Yun Jung ◽  
Min Young Lee

Hearing loss is a sensory deprivation that can affect the quality of life. Currently, only rehabilitation devices such as hearing aids and cochlear implants are used, without a definitive cure. However, in chronic hearing-deprived patients, in whom secondary auditory neural degeneration is expected, a relatively poor rehabilitation prognosis is projected. Stem cell therapy for cochlear neural structures would be an easier and feasible strategy compared with cochlear sensory cells. Considering the highly developed cochlear implantation technology, improving cochlear neural health has significant medical and social effects. Stem cell delivery to Rosenthal’s canal in an acutely damaged mouse model has been performed and showed cell survival and the possibility of differentiation. The results of stem cell transplantation in chronic auditory neural hearing loss should be evaluated because neural stem cell replacement therapy for chronic (long-term) sensorineural hearing loss is a major target in clinics. In the present study, we established a mouse model that mimicked chronic auditory neural hearing loss (secondary degeneration of auditory neurons after loss of sensory input). Then, mouse embryonic stem cells (mESCs) were transplanted into the scala tympani and survival and distribution of transplanted cells were compared between the acute and chronic auditory neural hearing loss models induced by ouabain or kanamycin (KM), respectively. The mESC survival was similar to the acute model, and perilymphatic distribution of cell aggregates was more predominant in the chronic model. Lastly, the effects of mESC transplantation on neural signal transduction observed in the cochlear nucleus (CN) were compared and a statistical increase was observed in the chronic model compared with other models. These results indicated that after transplantation, mESCs survived in the cochlea and increased the neural signaling toward the central auditory pathway, even in the chronic (secondary) hearing loss mouse model.


2021 ◽  
Author(s):  
Floriane Bretheau ◽  
Adrian Castellanos-Molina ◽  
Benoit Mailhot ◽  
Maxime Kusik ◽  
Dominic Belanger ◽  
...  

Abstract Spinal cord injury (SCI) triggers neuroinflammation, and subsequently secondary degeneration and oligodendrocyte (OL) death. We report that the alarmin interleukin (IL)-1α is released by damaged microglia after SCI. Intra-cisterna magna injection of IL-1α in mice rapidly induced neutrophil infiltration and OL death throughout the spinal cord, mimicking what is seen at sites of SCI. These effects were abolished by co-treatment with the IL-1R1 antagonist anakinra, as well as in IL-1R1-knockout mice which showed enhanced locomotor recovery after SCI. Conditional restoration of IL-1R1 expression in astrocytes or endothelial cells (ECs), but not in OLs or microglia, restored IL-1α-induced effects, while astrocyte- or EC-specific Il1r1 deletion reduced OL loss. Conditioned medium derived from IL-1α-stimulated astrocytes is toxic for OLs; further, IL-1α-stimulated astrocytes generate reactive oxygen species (ROS) and blocking ROS production in IL-1α-treated or SCI mice prevented OL loss. Thus, after SCI, microglia release IL-1α, which induces astrocyte- and EC-mediated OL degeneration.


Author(s):  
Åsa Bergström ◽  
Marco Gerling ◽  
Noémi Van Hul ◽  
Carlos Fernández Moro ◽  
Björn Rozell ◽  
...  

AbstractChronic cholestatic liver diseases including primary sclerosing cholangitis (PSC) present a complex spectrum with regards to the cause, age of manifestation and histopathological features. Current treatment options are severely limited primarily due to a paucity of model systems mirroring the disease. Here, we describe the Keratin 5 (K5)-Cre; Klf5fl/fl mouse that spontaneously develops severe liver disease during the postnatal period with features resembling PSC including a prominent ductular reaction, fibrotic obliteration of the bile ducts and secondary degeneration/necrosis of liver parenchyma. Over time, there is an expansion of Sox9+ hepatocytes in the damaged livers suggestive of a hepatocyte-mediated regenerative response. We conclude that Klf5 is required for the normal function of the hepatobiliary system and that the K5-Cre; Klf5fl/fl mouse is an excellent model to probe the molecular events interlinking damage and regenerative response in the liver.


Author(s):  
Ziyi Liu ◽  
Xinfeng Bai ◽  
Peifeng Wan ◽  
Fan Mo ◽  
Ge Chen ◽  
...  

Collagens are major constituents of the extracellular matrix (ECM) that play an essential role in the structure of the inner ear and provide elasticity and rigidity when the signals of sound are received and transformed into electrical signals. LOXL3 is a member of the lysyl oxidase (LOX) family that are copper-dependent amine oxidases, generating covalent cross-links to stabilize polymeric elastin and collagen fibers in the ECM. Biallelic missense variant of LOXL3 was found in Stickler syndrome with mild conductive hearing loss. However, available information regarding the specific roles of LOXL3 in auditory function is limited. In this study, we showed that the Col2a1-Cre-mediated ablation of Loxl3 in the inner ear can cause progressive hearing loss, degeneration of hair cells and secondary degeneration of spiral ganglion neurons. The abnormal distribution of type II collagen in the spiral ligament and increased inflammatory responses were also found in Col2a1–Loxl3–/– mice. Amino oxidase activity exerts an effect on collagen; thus, Loxl3 deficiency was expected to result in the instability of collagen in the spiral ligament and the basilar membrane, which may interfere with the mechanical properties of the organ of Corti and induce the inflammatory responses that are responsible for the hearing loss. Overall, our findings suggest that Loxl3 may play an essential role in maintaining hearing function.


2021 ◽  
Author(s):  
Robert J Casson ◽  
John P. M. Wood ◽  
Jack Ao ◽  
Jagjit Gilhotra ◽  
Shane Durkin ◽  
...  

Retinitis pigmentosa (RP) encompasses a genetically diverse group of blinding inherited retinal diseases. In most subtypes the gene defect is expressed in the rod photoreceptors, yet in many affected individuals the cone photoreceptors undergo secondary degeneration, leading to loss of the remaining central vision. There is evidence that bioenergetic and oxidative stress are involved in this secondary cone loss. Photobiomodulation (PBM) uses low energy light in the far red or near-infrared spectrum to manipulate cellular activity. We have used a novel slit lamp-mounted retinal PBM laser to deliver precise energy levels to targeted retina. We showed that PBM laser attenuates oxidative and bioenergetic stress-induced photoreceptor loss in vitro and rescues cones in the rd1 murine model of RP. In a phase I trial (ACTRN12618000651280), foveal laser treatment was safe in humans with RP and temporarily recovered, on average, 5 letters of visual acuity.


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