GCD

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Zhe Zhang - One of the best experts on this subject based on the ideXlab platform.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Youxue Zhang, Mei Liao, Tao Hu, Weihao Zheng, Bin Hu, Yu Zhao, Fan Yang, Linyan Su
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine (SVM) classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15%, 92.92%, and 89.83% respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from healthy controls. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Mei Liao, Weihao Zheng, Yu Zhao, Fan Yang, Zhijun Yao, Yuanwei Xie, Yan Zhang, Jurg Gutknecht, Dennis Majoe
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls; HCs) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15, 92.92, and 89.83%, respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from HCs. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

Harvey M Friedman - One of the best experts on this subject based on the ideXlab platform.

  • herpes simplex virus type 1 and 2 glycoprotein c prevents complement mediated neutralization induced by natural immunoglobulin m antibody
    2006
    Co-Authors: Lauren M Hook, John M Lubinski, Ming Jiang, Michael K Pangburn, Harvey M Friedman
    Abstract:

    Glycoprotein C (gC) of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) binds complement component C3b and protects virus from complement-mediated neutralization. Differences in complement interacting domains exist between gC of HSV-1 (gC1) and HSV-2 (gC2), since the amino terminus of gC1 blocks complement C5 from binding to C3b, while gC2 fails to interfere with this activity. We previously reported that neutralization of HSV-1 gC-null virus by HSV antibody-negative human serum requires activation of C5 but not of downstream components of the classical complement pathway. In this report, we evaluated whether activation of C5 is sufficient to neutralize HSV-2 gC-null virus, or whether formation of the membrane attack complex by C6 to C9 is required for neutralization. We found that activation of the classical complement pathway up to C5 was sufficient to neutralize HSV-2 gC-null virus by HSV antibody-negative human serum. We evaluated the mechanisms by which complement activation occurred in seronegative human serum. Interestingly, natural immunoglobulin M antibodies bound to virus, which triggered activation of C1q and the classical complement pathway. HSV antibody-negative sera obtained from four individuals differed over an approximately 10-fold range in their potency for complement-mediated virus neutralization. These findings indicate that humans differ in the ability of their innate immune systems to neutralize HSV-1 or HSV-2 gC-null virus and that a critical function of gC1 and gC2 is to prevent C5 activation.

  • kinetic analysis of glycoprotein c of herpes simplex virus types 1 and 2 binding to heparin heparan sulfate and complement component c3b
    2002
    Co-Authors: Ann H Rux, Huan Lou, John D Lambris, Harvey M Friedman, Roselyn J Eisenberg, Gary H Cohen
    Abstract:

    Abstract Glycoprotein C (gC) from herpes simplex virus (HSV) facilitates virus entry by attaching the virion to host cell-surface heparan sulfate (HS). Although gC from HSV-1 (gC1) and from HSV-2 (gC2) bind to heparin, gC2 is believed to play a less significant role than gC1 in attachment of virus to cells. This attachment step is followed by the binding of gD to one of several cellular receptors. gC also plays an important role in immune evasion by binding to the C3b fragment of the third component of the host complement system. Yet, although both gC1 and gC2 protect HSV against complement-mediated neutralization, only gC on HSV-1-infected cells acts as a receptor for C3b. We used optical biosensor technology to quantitate the affinities ( K D ) and the stabilities ( k off ) between both serotypes of gC with heparin, HS, and C3b to address three questions concerning gC interactions. First, can differences in affinity or stability account for differences between the contributions of HSV-1 and HSV-2 gC in attachment? Our data show that the gC2–HS complex is highly unstable ( k off = 0.2 s −1 ) compared to the gC1–HS complex ( k off = 0.003 s −1 ), suggesting why gC2 may not play an important role in attachment of virus to cells as does gC1. Second, does gC2 have a lower affinity for C3b than does gC1, thereby explaining the lack of C3b-receptor activity on HSV-2 infected cells? Surprisingly, gC2 had a 10-fold higher affinity for C3b compared to gC1, so this functional difference in serotypes cannot be accounted for by affinity. Third, do differences in gC–HS and gD-receptor affinities support a model of HSV entry in which the gC–HS interaction is of lower affinity than the gD-receptor interaction? Our biosensor results indicate that gC has a higher affinity for HS than gD does for cellular receptors HveA (HVEM) and HveC (nectin-1).

Linyan Su - One of the best experts on this subject based on the ideXlab platform.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Youxue Zhang, Mei Liao, Tao Hu, Weihao Zheng, Bin Hu, Yu Zhao, Fan Yang, Linyan Su
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine (SVM) classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15%, 92.92%, and 89.83% respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from healthy controls. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

Dennis Majoe - One of the best experts on this subject based on the ideXlab platform.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Mei Liao, Weihao Zheng, Yu Zhao, Fan Yang, Zhijun Yao, Yuanwei Xie, Yan Zhang, Jurg Gutknecht, Dennis Majoe
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls; HCs) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15, 92.92, and 89.83%, respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from HCs. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

Mei Liao - One of the best experts on this subject based on the ideXlab platform.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Youxue Zhang, Mei Liao, Tao Hu, Weihao Zheng, Bin Hu, Yu Zhao, Fan Yang, Linyan Su
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine (SVM) classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15%, 92.92%, and 89.83% respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from healthy controls. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.

  • frequency specific functional connectivity density as an effective biomarker for adolescent generalized anxiety disorder
    2017
    Co-Authors: Zhe Zhang, Mei Liao, Weihao Zheng, Yu Zhao, Fan Yang, Zhijun Yao, Yuanwei Xie, Yan Zhang, Jurg Gutknecht, Dennis Majoe
    Abstract:

    Several neuropsychiatric diseases have been found to influence the frequency-specific spontaneous functional brain organization (SFBO) in resting state, demonstrating that the abnormal brain activities of different frequency bands are associated with various physiological and psychological dysfunctions. However, little is known about the frequency specificities of SFBO in adolescent generalized anxiety disorder (GAD). Here, a novel complete ensemble empirical mode decomposition with adaptive noise method was applied to decompose the time series of each voxel across all participants (31 adolescent patients with GAD and 28 matched healthy controls; HCs) into four frequency-specific bands with distinct intrinsic oscillation. The functional connectivity density (FCD) of different scales (short-range and long-range) was calculated to quantify the SFBO changes related to GAD within each above frequency-specific band and the conventional frequency band (0.01-0.08 Hz). Support vector machine classifier was further used to examine the discriminative ability of the frequency-specific FCD values. The results showed that adolescent GAD patients exhibited abnormal alterations of both short-range and long-range FCD (S-FCD and L-FCD) in widespread brain regions across three frequency-specific bands. Positive correlation between the State Anxiety Inventory (SAI) score and increased L-FCD in the fusiform gyrus in the conventional frequency band was found in adolescents with GAD. Both S-FCD and L-FCD in the insula in the lower frequency band (0.02-0.036 Hz) had the highest classification performance compared to all other brain regions with inter-group difference. Furthermore, a satisfactory classification performance was achieved by combining the discrepant S-FCD and L-FCD values in all frequency bands, with the area under the curve (AUC) value of 0.9414 and the corresponding sensitivity, specificity, and accuracy of 87.15, 92.92, and 89.83%, respectively. This study indicates that the alterations of SFBO in adolescent GAD are frequency dependence and the frequency-specific FCD can potentially serve as a valuable biomarker in discriminating GAD patients from HCs. These findings may provide new insights into the pathophysiological mechanisms of adolescent GAD.