Biomedical subjects

Yue Cao

Publications and source records attributed to Yue Cao.

5 recordsLinked to original sources

PubMed2003

An ER-fMRI investigation of morphological inflection in German reveals that the brain makes a distinction between regular and irregular forms.

The hypothesis that morphological processing is supported by a mental dictionary of stored entries plus a set of mental computations based on rules is examined using event-related fMRI. If a rules-plus-memory model () reflects the actual organization of the language faculty, two distinct patterns of brain activation should be observed for production of German irregular and regular noun and verb inflections. If a connectionist alternative to the rules-and-memory model (, and many others since), which seeks to explain the production of both irregular and regular forms within a single associative memory mechanism, is correct, there should be no neural differentiation between German regular and irregular inflection. The results we report support the existence of substantially differing patterns of activation for regulars vs. irregulars, an outcome that is consistent with the two-component rules-plus-memory account.

Adult↗

PubMed2003

Visual distortion provoked by a stimulus in migraine associated with hyperneuronal activity.

BACKGROUND: Migraineurs with visual aura are highly susceptible to illusions and visual distortion and are particularly sensitive to a pattern of regularly spaced parallel lines or stripes. PURPOSE: To determine whether the high degree of susceptibility to illusions and visual distortion in migraineurs with aura is associated with hyperneurological activity of the occipital cortex. METHODS: In order to investigate any relationships among neuronal activity, spatial frequency of square-wave gratings, and self-described visual distortion, we investigated the neuronal and psychophysical responses to square-wave gratings in migraineurs with visual aura and in nonheadache controls. RESULTS: Square-wave gratings provoked various types of visual distortion and illusions and induced a hyperneuronal response in the visual cortex of migraineurs with visual aura, a response that strongly depended upon the stimulus spatial frequency. CONCLUSION: The hyperneuronal activity of the occipital cortex is consistent with general cortical hyperexcitability in migraine.

Adult↗

PubMed2002

Comparing cortical activations for silent and overt speech using event-related fMRI.

At present, functional magnetic resonance imaging (fMRI) of cortical language functions favors "silent" task paradigms with no overt speaking, due to severe motion artifacts in MR images induced by vocalization. To the extent that the neural substrate of silent speaking might differ from that of overt speaking, this is a problem for understanding spoken language. The present study combined event related fMRI methodology with a set of techniques for motion reduction, detection, and correction to further investigate overt speech and compare it to silent speech. The purpose of the study was two-fold. We aimed to test a multiple-step image processing protocol involving discrimination and separation of motion-induced signals from activation-induced signals and we aimed to use this multi-step image processing protocol to compare the similarity of activation of cortical pathways potentially relevant to language production during silent and overt speech, focusing on Broca area and primary motor cortex as test cases. If the problem of motion artifact can be handled effectively, fMRI can add greatly to the tools available to investigate human language.

Adult↗

PubMed2002

Anti-thrombin is expressed in the benign prostatic epithelium and in prostate cancer and is capable of forming complexes with prostate-specific antigen and human glandular kallikrein 2.

Anti-thrombin, a member of the serpin family and an inhibitor of thrombin and blood coagulation factor Xa, was recently shown to inhibit angiogenesis and tumor growth. In the present study, we examined the expression of anti-thrombin in benign and malignant prostate gland. Using immunohistochemistry, anti-thrombin was found in prostate epithelium and stroma cells. Tissue microarrays of tumors (n = 112) and three different prostate cancer cell lines (PC-3, LNCaP, and DU-145) were all positive for anti-thrombin. Abundant expression in a population of prostatic tumor cells was further evidenced by in situ hybridization experiments. The immunostaining for anti-thrombin was confined to the cytoplasm, was most intense in Gleason grade 3 tumors, and in part overlapped with that of prostate-specific antigen. Western blotting of benign and malignant tissue homogenates revealed a predominant 58-kd anti-thrombin immunoreactive component. In vitro, anti-thrombin formed complexes more readily with human kallikrein 2, particularly in the presence of heparin, and less efficiently with prostate-specific antigen. Both complexes could be recognized by polyclonal and monoclonal IgGs against anti-thrombin. We conclude that anti-thrombin is widely expressed in prostate cancer but is gradually lost in tumors of high Gleason grade. Anti-thrombin may act as a local anti-angiogenic factor, the effect of which is partially lost in poorly differentiated prostatic tumors.

Animals↗

PubMed2002

High b-value diffusion imaging.

Perhaps one of the greatest benefits of the development of high b-value technology has been the insight provided into the physiologic basis of diffusion imaging. The multiexponential features of the diffusion process are revealed on scans obtained with high b-value. The subsequent isotropic diffusion images have the distinct advantage of more accurately reflecting the intrinsic ADC of the tissues examined. This feature has the potential to facilitate clinical diagnosis. The degree to which this is proved to be clinically relevant is dependent on future investigation, but initial results are promising. The clinical potential of high b-value imaging at higher field strength remains to be explored. The greater signal to noise afforded by the use of 3-T scanners will likely make higher b-value imaging more practical with less costly scan time penalties necessary at lower field strengths.

Blood-Brain Barrier↗