[Pathomechanisms of Autoantibody Production Against the Nervous System].

[Pathomechanisms of Autoantibody Production against the Nervous System].

Brain Nerve. 2013 Apr; 65(4): 323-32
Arimura K

Abstract In immune-mediated neurological disorders, the production of autoantibodies against the nervous system occurs mainly because of impaired immune tolerance. In myasthenia gravis (MG), the thymus shows pathologic alterations, particularly in anti-AChR antibody-positive patients. Further, resection of the thymus induces a clinical recovery. The MG thymus contains all the elements, including AChR antigens, AChR-specific T cells, and antigen-secreting B cells, that are required to initiate and sustain autoantibody production. Central tolerance, established by the repertoire selection of immature T lymphocytes in the thymus, is impaired in MG patients who are positive for anti-AChR antibodies. Recent evidence suggests that chronic inflammation elicited by viral infection is important for the production of AChR antibodies. Antibodies against ganglioside are crucial for the diagnosis of Guillain-Barre syndrome (GBS). Molecular mimicry between the lipooligosaccharides of Camplylobacter jejuni and gangliosides of the peripheral nerve causes the production of antibodies. However, less than 1 in 1000 patients infected with C. jejuni develop GBS. This fact suggests that some host factors might influence the production of antibodies. A recent hypothesis suggests that transient impairment of peripheral tolerance due to infection may play a crucial role in GBS pathogenesis. In summary, autoantibody production might correlate with the impairment of immune tolerance as well as with innate immunity. HubMed – rehab

Brevetoxicosis in seabirds naturally exposed to karenia brevis blooms along the central west coast of Florida.

J Wildl Dis. 2013 Apr; 49(2): 246-60
Fauquier DA, Flewelling LJ, Maucher JM, Keller M, Kinsel MJ, Johnson CK, Henry M, Gannon JG, Ramsdell JS, Landsberg JH

Harmful algal bloom events caused by the dinoflagellate Karenia brevis occurred along the central west Florida, USA, coast from February 2005 through December 2005 and from August 2006 through December 2006. During these events, from 4 February 2005 through 28 November 2006, live, debilitated seabirds admitted for rehabilitation showed clinical signs that included disorientation, inability to stand, ataxia, and seizures. Testing of blood, biologic fluids, and tissues for brevetoxin by enzyme-linked immunosorbent assay found toxin present in 69% (n=95) of rehabilitating seabirds. Twelve of the 19 species of birds had evidence of brevetoxin exposure. Commonly affected species included Double-crested Cormorants (Phalacrocorax auritus), Brown Pelicans (Pelecanus occidentalis), Great Blue Herons (Ardea herodias), and Common Loons (Gavia immer). Serial blood and fecal samples taken from several live seabirds during rehabilitation showed that brevetoxin was cleared within 5-10 days after being admitted to the rehabilitation facility, depending on the species tested. Among seabirds that died or were euthanized, the highest brevetoxin concentrations were found in bile, stomach contents, and liver. Most dead birds had no significant pathologic findings at necropsy, thereby supporting brevetoxin-related mortality. HubMed – rehab

Effect of low-level laser therapy (LLLT) on acute neural recovery and inflammation-related gene expression after crush injury in rat sciatic nerve.

Lasers Surg Med. 2013 Apr 8;
Alcântara CC, Gigo-Benato D, Salvini TF, Oliveira AL, Anders JJ, Russo TL

BACKGROUND AND OBJECTIVES: Peripheral nerve function can be debilitated by different kinds of injury. Low-level laser therapy (LLLT) has been used successfully during rehabilitation to stimulate recovery. The aim of this study was to evaluate the effects of LLLT (660?nm, 60?J/cm(2) , 40?mW/cm(2) ) on acute sciatic nerve injury. MATERIALS AND METHODS: Thirty Wistar male rats were divided into three groups: (1) Normal, intact nerves; (2) I3d, crushed nerves evaluated on Day-3 post-injury; (3) I?+?L3d, crushed nerves submitted to two sessions of LLLT and investigated at 3 days post-injury. Sciatic nerves were removed and processed for gene expression analysis (real-time PCR) of the pro-inflammatory factors TWEAK, Fn14 and TNF-? and extracellular matrix remodeling and axonal growth markers, such as TIMP-1, MMP-2, and MMP-9. Zymography was used to determine levels of MMP-2 and MMP-9 activity and Western blotting was used to evaluate TNF-? protein content. Shapiro-Wilk and Levene’s tests were applied to evaluate data normality and homogeneity, respectively. One-way ANOVA followed by Tukey test was used for statistical analysis with a significance level set at 5%. RESULTS: An increase in TNF-? protein level was found in I?+?L3 compared to Normal and I3d (P?HubMed – rehab

Continuous detection of muscle aspect ratio using keypoint tracking in ultrasonography.

IEEE Trans Biomed Eng. 2013 Apr 4;
Li Q, Zhang H, Chen X, Qi S, Chen S, Wang T

Muscle aspect ratio of cross-sectional area (CSA) is one of the most widely used parameters for quantifying muscle function in both diagnosis and rehabilitation assessment. Ultrasound imaging has been frequently used to non-invasively study the characteristics of human muscles as a reliable method. However, the aspect ratio measurement is traditionally conducted by manual digitization of reference points, thus it is subjective, time-consuming and prone to errors. In this paper, a novel method is proposed to continuously detect the muscle aspect ratio. Two keypoint pairs are manually digitized on the lateral and longitudinal borders at the first frame, and automatically tracked by optical flow technique at the subsequent frames. The muscle aspect ratio is thereby obtained based on the estimated muscle width and thickness. Six ultrasound sequences from different subjects are used to evaluate this method, and the overall coefficient of multiple correlation (CMC) of the results between manual and proposed method is 0.97±0.02. The linear regression show that a good linear correlation between the results of the two methods is obtained (R2 = 0.974), with difference -0.01±0.16. The method proposed here provides an accurate, high repeatable and efficient approach for estimating muscle aspect ratio during human motion, thus justifying its application in biological sciences. HubMed – rehab

Effects of a Low-Volume, Vigorous Intensity Step Exercise Program on Functional Mobility in Middle-Aged Adults.

Ann Biomed Eng. 2013 Apr 9;
Doheny EP, McGrath D, Ditroilo M, Mair JL, Greene BR, Caulfield B, De Vito G, Lowery MM

Aging-related decline in functional mobility is associated with loss of independence. This decline may be mitigated through programs of physical activity. Despite reports of aging-related mobility impairment in middle-aged adults, this age group has been largely overlooked in terms of exercise programs that target functional mobility and the preservation of independence in older age. A method to quantitatively assess changes in functional mobility could direct rehabilitation in a proactive rather than reactive manner. Thirty-three healthy but sedentary middle-aged adults participated in a four week low-volume, vigorous intensity stepping exercise program. Two baseline testing sessions and one post-training testing session were conducted. Functional mobility was assessed using the timed up and go (TUG) test, with its constituent sit-to-walk and walk-to-sit phases examined using a novel inertial sensor-based method. Additionally, semi-tandem balance and knee extensor muscle isometric torque were assessed. Trunk acceleration during walk-to-sit reduced significantly post-training, suggesting altered movement control due to the exercise program. No significant training-induced changes in sit-to-walk acceleration, TUG time, balance or torque were observed. The novel method of functional mobility assessment presented provides a reliable means to quantify subtle changes in mobility during postural transitions. Over time, this exercise program may improve functional mobility. HubMed – rehab