Focal Solute Trapping and Global Glymphatic Pathway Impairment in a Murine Model of Multiple Microinfarcts.

Microinfarcts occur commonly in the aging brain as a consequence of diffuse embolic events and are associated with the development of vascular dementia and Alzheimer's disease. However, the manner in which disperse microscopic lesions reduce global cognitive function and increase the risk for Alzheimer's disease is unclear. The glymphatic system, which is a brain-wide perivascular network that supports the recirculation of CSF through the brain parenchyma, facilitates the clearance of interstitial solutes including amyloid ß and tau. We investigated whether glymphatic pathway function is impaired in a murine model of multiple microinfarcts induced by intraarterial injection of cholesterol crystals. The analysis showed that multiple microinfarcts markedly impaired global influx of CSF along the glymphatic pathway. Although suppression of global glymphatic function was transient, resolving within 2 weeks of injury, CSF tracers also accumulated within tissue associated with microinfarcts. The effect of diffuse microinfarcts on global glymphatic pathway function was exacerbated in the mice aged 12 months compared with the 2- to 3-month-old mice. These findings indicate that glymphatic function is focally disrupted around microinfarcts and that the aging brain is more vulnerable to this disruption than the young brain. These observations suggest that microlesions may trap proteins and other interstitial solutes within the brain parenchyma, increasing the risk of amyloid plaque formation.SIGNIFICANCE STATEMENT Microinfarcts, small (<1 mm) ischemic lesions, are strongly associated with age-related dementia. However, how these microscopic lesions affect global cognitive function and predispose to Alzheimer's disease is unclear. The glymphatic system is a brain-wide network of channels surrounding brain blood vessels that allows CSF to exchange with interstitial fluid, clearing away cellular wastes such as amyloid ß. We observed that, in mice, microinfarcts impaired global glymphatic function and solutes from the CSF became trapped in tissue associated with microinfarcts. These data suggest that small, disperse ischemic lesions can impair glymphatic function across the brain and trapping of solutes in these lesions may promote protein aggregation and neuroinflammation and eventually lead to neurodegeneration, especially in the aging brain.

Antibodies to sulfatide in cerebrospinal fluid of patients with multiple sclerosis.

The identity of target antigen(s) in multiple sclerosis (MS) remains elusive despite much effort to identify it. We analyzed cerebrospinal fluid (CSF) from patients with MS, other neurological diseases (OND), other diseases (OD) and healthy controls for antibodies against purified sulfatide, a major glycosphingolipid of human myelin, by an enzyme-linked immunosorbent assay (ELISA) and a thin-layer chromatogram (TLC)-immunostaining technique. Elevated anti-sulfatide antibodies were significantly higher in MS patients as compared with the OND group (p<0.05) and all controls combined (P<0.025). Binding of high titer antibodies to sulfatide was confirmed with TLC-immunostaining. Anti-sulfatide antibodies were detected in all subtypes of MS although the frequency was higher in patients with secondary progressive MS (SPMS) than in patients with primary progressive (PPMS) and relapsing-remitting MS (RRMS). The data demonstrate a humoral response to sulfatide in the CSF of patients with MS.

[Infrared spectroscopy of the dry residue of liquor crystallograms in various diseases]. / Infrakrasnaia spektroskopiia sukhogo ostatka kristallogramm likvora pri razlichnykh patologicheskikh sostoianiiakh.

The article presents the results of an examination of the dry residue of liquor crystallograms (DRLC) using infrared spectroscopy technique. 36 spectrograms were studied. Elements of similarity and difference were revealed in the spectrograms of organic substance (antifreeze, sodium cyclamate and fatty tissue), of DRLC of the crystal-forming matter CuCl(2)x2H(2)0, of DRLC of a live person and cadaveric liquor (with no brain injury in respective case histories), of DRLC of liquor of live persons with a brain injury, of DRLC of liquor of persons who died of a brain injury and of persons who died of other causes.