Language processing of auditory cortex revealed by functional magnetic resonance imaging in presbycusis patients.

CONCLUSION: Contralateral temporal lobe activation decreases with aging, regardless of hearing status, with elderly individuals showing reduced right ear advantage. BACKGROUND: Aging and hearing loss possibly lead to presbycusis speech discrimination decline. OBJECTIVES: To evaluate presbycusis patients' auditory cortex activation under verbal stimulation. METHOD: Thirty-six patients were enrolled: 10 presbycusis patients (mean age = 64 years, range = 60-70), 10 in the healthy aged group (mean age = 66 years, range = 60-70), and 16 young healthy volunteers (mean age = 25 years, range = 23-28). These three groups underwent simultaneous 1 kHz and 90 dB single-syllable word stimuli and (blood-oxygen-level-dependent functional magnetic resonance imaging) BOLD fMRI examinations. RESULTS: The main activation regions were superior temporal and middle temporal gyrus. For all aged subjects, the right region of interest (ROI) activation volume was decreased compared with the young group. With left ear stimulation, bilateral ROI activation intensity held. With right ear stimulation, the aged group's activation intensity was higher. Using monaural stimulation in the young group, contralateral temporal lobe activation volume and intensity were higher vs ipsilateral, while they were lower in the aged and presbycusis groups. On left and right ear auditory tasks, the young group showed right ear advantage, while the aged and presbycusis groups showed reduced right ear advantage.

[Study on the purification and scavenging free radical activity of water soluble polysaccharide of leave in Hippohae rhamnoides L].

The crude polysaccharide was extracted from Leave in Hippohae rhamnoides L. with hot water, and precipitated by ethanol. The crude polysaccharide has been fractionated by acidic ethanol. Three fractions (SJ1, SJ2, SJ3) were got respectively. SJ2 deproteinizationed by the combined methods of enzyme and Seveage, purified by DEAE-Sephadex A-25 gel filtration. PC analysis indicated that SJ22 is composed of Xyl,Ara,Glc,Gal,GaL A. The identification of purify by Sepharose CL-4B, paper chromatography and cellulous acetate electrophoresis showed it was homogeneous. Typical absorption of polysaccharides was shown in its IR spectrum. It contained a-glucosidic bonds by IR analysis. It had typical absorption of protein by UV scaning. SJ22 is first isolated from Leave in Hippohae rhamnoides L Scavenging free radical experiment showed that SJ22 was effective in scavenging superoxideradical and hydroxylradical, but only a little effective in scavenging lipid radical.