The Experts below are selected from a list of 121884 Experts worldwide ranked by ideXlab platform
George Ayala - One of the best experts on this subject based on the ideXlab platform.
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modeling the impact of Social Discrimination and financial hardship on the sexual risk of hiv among latino and black men who have sex with men
American Journal of Public Health, 2012Co-Authors: George Ayala, Trista Bingham, Junyeop Kim, Darrell P Wheeler, Gregorio A MillettAbstract:Objectives. We examined the impact of Social Discrimination and financial hardship on unprotected anal intercourse with a male sex partner of serodiscordant or unknown HIV status in the past 3 months among 1081 Latino and 1154 Black men who have sex with men (MSM; n = 2235) residing in Los Angeles County, California; New York, New York; and Philadelphia, Pennsylvania.Methods. We administered HIV testing and a questionnaire assessing 6 explanatory variables. We combined traditional mediation analysis with the results of a path analysis to simultaneously examine the direct, indirect, and total effects of these variables on the outcome variable.Results. Bivariate analysis showed that homophobia, racism, financial hardship, and lack of Social support were associated with unprotected anal intercourse with a serodiscordant or sero-unknown partner. Path analysis determined that these relations were mediated by participation in risky sexual situations and lack of Social support. However, paths between the explana...
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homophobia and racism experienced by latino men who have sex with men in the united states correlates of exposure and associations with hiv risk behaviors
Aids and Behavior, 2012Co-Authors: Yuko Mizuno, Gregorio A Millett, Trista Bingham, George Ayala, Craig B. Borkowf, Ann StueveAbstract:Using cross-sectional data collected from 1081 Latino men who have sex with men (MSM) recruited with respondent-driven sampling (RDS) techniques from Los Angeles and New York, we examined the extent to which Latino MSM reported exposure to Social Discrimination (i.e., experienced both homophobia and racism, homophobia only, racism only, or neither homophobia nor racism). More than 40% of respondents experienced both homophobia and racism in the past 12 months. Los Angeles participants, those with lower income, and those who reported being HIV-positive were more likely to report experiencing both types of Social Discrimination. Adjusting for potential confounders, men exposed to both homophobia and racism were more likely than men exposed to neither form of Discrimination to report unprotected receptive anal intercourse with a casual sex partner (AOR = 1.92, 95% CI, 1.18–3.24) and binge drinking (AOR = 1.42, 95% CI, 1.02–1.98). Our findings suggest the presence of a syndemic of adverse Social experiences and call for more intervention research to address both homophobia and racism experienced among Latino MSM in the United States.
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strategies for managing racism and homophobia among u s ethnic and racial minority men who have sex with men
Aids Education and Prevention, 2011Co-Authors: Kyunghee Choi, Jay P Paul, George AyalaAbstract:Despite widespread recognition that experiences of Social Discrimination can lead to poor physical and mental health outcomes for members of minority groups, little is known about how U.S. ethnic minority men who have sex with men (MSM) manage their experiences of racism and homophobia. We conducted six focus group discussions (n=50) and 35 in-depth interviews with African American, Latino, and Asian or Pacific Islander MSM (aged 18+) recruited in Los Angeles, CA. This process revealed five strategies that MSM of color employed in order to mitigate the impact of racism and homophobia. To minimize opportunities for stigmatization, men used (1) concealment of homosexuality and (2) disassociation from Social settings associated with stigmatization. To minimize the impact of experienced stigma, men (3) dismissed the stigmatization and (4) drew strength and comfort from external sources. Men also actively countered stigmatization by (5) direct confrontation. More research is needed to understand the efficacy of these coping strategies in mitigating negative health consequences of stigmatization and Discrimination.
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use. Language: en
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use.
Mario Engelmann - One of the best experts on this subject based on the ideXlab platform.
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consequences of temporary inhibition of the medial amygdala on Social recognition memory performance in mice
Frontiers in Neuroscience, 2015Co-Authors: Julia Noack, Rita Murau, Mario EngelmannAbstract:Different lines of investigation suggest that the medial amygdala is causally involved in the processing of information linked to Social behaviour in rodents. Here we investigated the consequences of temporary inhibition of the medial amygdala by bilateral injections of lidocaine on long-term Social recognition memory as tested in the Social Discrimination task. Lidocaine or control NaCl solution was infused immediately before learning or before retrieval. Our data show that lidocaine infusion immediately before learning did not affect long-term memory retrieval. However, intra-amygdalar lidocaine infusions immediately before choice interfered with correct memory retrieval. Analysis of the aggressive behaviour measured simultaneously during all sessions in the Social recognition memory task support the impression that the lidocaine dosage used here was effective as it – at least partially – reduced the aggressive behaviour shown by the experimental subjects towards the juveniles. Surprisingly, also infusions of NaCl solution blocked recognition memory at both injection time points. The results are interpreted in the context of the importance of the medial amygdala for the processing of non-volatile odours as a major contributor to the olfactory signature for Social recognition memory.
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chronic infusion of a crh1 receptor antisense oligodeoxynucleotide into the central nucleus of the amygdala reduced anxiety related behavior in Socially defeated rats
Regulatory Peptides, 1995Co-Authors: Gudrun Liebsch, J C Probst, Rudiger Gerstberger, Mario Engelmann, Rainer Landgraf, Florian Holsboer, Carsten T Wotjak, Alexandra MontkowskiAbstract:We studied the role of central amygdala CRH receptors in behavioral responses to an anxiogenic stimulus. An antisense oligodeoxynucleotide corresponding to the rat CRH1 receptor mRNA was infused chronically into the central amygdaloid nucleus of male rats via osmotic minipumps (0.25 μg/0.5 μl/h). Control groups received infusions of either a scrambled sequence oligodeoxynucleotide or vehicle. On the 4th day of treatment, rats were subjected to 10 min of Social defeat and immediately afterwards tested on the elevated plus-maze. Antisense oligodeoxynucleotide-treated rats spent significantly more time exploring the open arms of the plus-maze than scrambled sequence- and vehicle-treated animals, both of which did not differ from each other. The Social Discrimination test, on the other hand, revealed no difference in juvenile recognition abilities among the treatment groups. Using in situ hybridization and receptor autoradiography, we were not able to detect clear signals of CRH1 receptor mRNA and CRH binding sites in the central amygdaloid nucleus of either group, confirming the reportedly low expression and density of CRH receptors in this brain area. The present data support the view that CRH receptors in the central nucleus of the amygdala are involved in the mediation and expression of anxiety-related behavior, but simultaneously raise questions as to the mechanisms of antisense oligodeoxynucleotide action.
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Social Discrimination procedure an alternative method to investigate juvenile recognition abilities in rats
Physiology & Behavior, 1995Co-Authors: Mario Engelmann, Carsten T Wotjak, Rainer LandgrafAbstract:Experiments were performed to establish the Social Discrimination procedure as an alternative method to the widely used Social recognition test for investigating short-term olfactory memory processes in rats. The time that 4-mo old male animals spent investigating conspecific juveniles was taken as an index of their juvenile recognition/Discrimination abilities. When the same juvenile was reexposed to the adult 30 min after its initial exposure, it was investigated at a significantly lower intensity compared to a simultaneously presented novel juvenile. If the second exposure to the previously exposed juvenile occurred 2 h later, however, both juveniles were investigated equally, indicating an extinction of olfactory memory. The simultaneous presentation of the previously exposed juvenile and novel juvenile provides not only an internal control under identical experimental conditions (thus reducing the number of sessions for a given experimental series), but also the opportunity to separate specific (i.e., memory-related) from nonspecific (i.e., investigatory behavior-suppression) effects in pharmacological studies. Furthermore, the Social Discrimination procedure enables even in sexually naive adult male rats the detection of juvenile recognition abilities which seem to be masked in the Social recognition test by sexual/aggressive behavior-motivated investigation. The method described here might be an attractive alternative to the conventional Social recognition procedure.
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v1 vasopressin receptor antisense oligodeoxynucleotide into septum reduces vasopressin binding Social Discrimination abilities and anxiety related behavior in rats
The Journal of Neuroscience, 1995Co-Authors: Rainer Landgraf, J C Probst, Alexandra Montkowski, Rudiger Gerstberger, Florian Holsboer, Carsten T Wotjak, Mario EngelmannAbstract:To develop and validate a vasopressin (AVP) receptor knockdown strategy, we infused an antisense oligodeoxynucleotide to the V1 subtype mRNA into the septum of male rats with osmotic minipumps and measured behavioral, cellular and molecular parameters. Compared to vehicle and scrambled-sequence oligo controls, chronic antisense administration for up to 4 d diminished the ability of the animals to distinguish a previously exposed juvenile from a novel one and to respond to exogenous AVP (1 ng/5 microliters, intracerebroventricular) with an improved Social memory. Furthermore, anxiety-related behavior was reduced. As measured in the behaviorally tested rats, antisense treatment resulted in a reduced binding of radiolabeled AVP in the septum, but not in other limbic brain areas (receptor autoradiography), and an increased amount of V1 receptor mRNA (reverse transcriptase PCR), indicating translational arrest and ongoing transcriptional activity. In sense oligo-treated rats, on the other hand, both the Social and the anxiety-related behavior scores lay between levels obtained in control and antisense-treated animals. These sense-treated rats showed a slightly reduced V1 receptor density in the septum and reduced receptor mRNA levels, indicating hybridization of the sense oligo to the DNA. The data show the potential of antisense targeting to further reveal relationships between local gene expression, neuropeptide-receptor interactions in distinct brain areas, and behavioral performance.
Rainer Landgraf - One of the best experts on this subject based on the ideXlab platform.
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viral vector mediated gene transfer of the vole v1a vasopressin receptor in the rat septum improved Social Discrimination and active Social behaviour
European Journal of Neuroscience, 2003Co-Authors: Rainer Landgraf, Inga D Neumann, Elisabeth Frank, John Matthew Aldag, Catherine A Sharer, Ernest F Terwilliger, Massanobu Niwa, A Wigger, Larry J YoungAbstract:This study explores the effects of enhancing vasopressin Via receptor expression in the septum using viral vector-mediated gene transfer on Social Discrimination and Social interactions. Bilateral infusion of an adeno-associated viral vector containing the prairie vole V1 a receptor gene (V1aR-AAV) regulated by a neuron-specific enolase promoter resulted in a stable increase in V1 a receptor binding density in the rat septum without affecting oxytocin receptor density. Control animals were infused with a vector expressing the lacZ gene. In a Social Discrimination paradigm, only V1aR-AAV-treated animals succeeded in discriminating a previously encountered from a novel juvenile after an interexposure interval (IEI) of more than 2 h, demonstrating the functional incorporation of the vole Via a receptor in the rat septal circuits underlying short-term memory processes. Microdialysis administration of synthetic vasopressin during the first juvenile exposure, used to mimic intraseptal release patterns of the neuropeptide, produced similar prolongations in recognition (up to an IEI of 24 h) in both VlaR-AAV and control animals. Septal microdialysis administration of a selective V1 a, but not oxytocin, receptor antagonist in both groups prevented Discrimination even after an IEI of as short as 0.5h, confirming the specificity of the vole Via receptor involvement in Social Discrimination abilities. In addition, active Social interactions were found to be increased among V1aR-AAV rats compared to controls. Viral vector-mediated gene transfer provides a valuable tool for studies on the role of localized gene expression on behavioural parameters.
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chronic infusion of a crh1 receptor antisense oligodeoxynucleotide into the central nucleus of the amygdala reduced anxiety related behavior in Socially defeated rats
Regulatory Peptides, 1995Co-Authors: Gudrun Liebsch, J C Probst, Rudiger Gerstberger, Mario Engelmann, Rainer Landgraf, Florian Holsboer, Carsten T Wotjak, Alexandra MontkowskiAbstract:We studied the role of central amygdala CRH receptors in behavioral responses to an anxiogenic stimulus. An antisense oligodeoxynucleotide corresponding to the rat CRH1 receptor mRNA was infused chronically into the central amygdaloid nucleus of male rats via osmotic minipumps (0.25 μg/0.5 μl/h). Control groups received infusions of either a scrambled sequence oligodeoxynucleotide or vehicle. On the 4th day of treatment, rats were subjected to 10 min of Social defeat and immediately afterwards tested on the elevated plus-maze. Antisense oligodeoxynucleotide-treated rats spent significantly more time exploring the open arms of the plus-maze than scrambled sequence- and vehicle-treated animals, both of which did not differ from each other. The Social Discrimination test, on the other hand, revealed no difference in juvenile recognition abilities among the treatment groups. Using in situ hybridization and receptor autoradiography, we were not able to detect clear signals of CRH1 receptor mRNA and CRH binding sites in the central amygdaloid nucleus of either group, confirming the reportedly low expression and density of CRH receptors in this brain area. The present data support the view that CRH receptors in the central nucleus of the amygdala are involved in the mediation and expression of anxiety-related behavior, but simultaneously raise questions as to the mechanisms of antisense oligodeoxynucleotide action.
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Social Discrimination procedure an alternative method to investigate juvenile recognition abilities in rats
Physiology & Behavior, 1995Co-Authors: Mario Engelmann, Carsten T Wotjak, Rainer LandgrafAbstract:Experiments were performed to establish the Social Discrimination procedure as an alternative method to the widely used Social recognition test for investigating short-term olfactory memory processes in rats. The time that 4-mo old male animals spent investigating conspecific juveniles was taken as an index of their juvenile recognition/Discrimination abilities. When the same juvenile was reexposed to the adult 30 min after its initial exposure, it was investigated at a significantly lower intensity compared to a simultaneously presented novel juvenile. If the second exposure to the previously exposed juvenile occurred 2 h later, however, both juveniles were investigated equally, indicating an extinction of olfactory memory. The simultaneous presentation of the previously exposed juvenile and novel juvenile provides not only an internal control under identical experimental conditions (thus reducing the number of sessions for a given experimental series), but also the opportunity to separate specific (i.e., memory-related) from nonspecific (i.e., investigatory behavior-suppression) effects in pharmacological studies. Furthermore, the Social Discrimination procedure enables even in sexually naive adult male rats the detection of juvenile recognition abilities which seem to be masked in the Social recognition test by sexual/aggressive behavior-motivated investigation. The method described here might be an attractive alternative to the conventional Social recognition procedure.
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v1 vasopressin receptor antisense oligodeoxynucleotide into septum reduces vasopressin binding Social Discrimination abilities and anxiety related behavior in rats
The Journal of Neuroscience, 1995Co-Authors: Rainer Landgraf, J C Probst, Alexandra Montkowski, Rudiger Gerstberger, Florian Holsboer, Carsten T Wotjak, Mario EngelmannAbstract:To develop and validate a vasopressin (AVP) receptor knockdown strategy, we infused an antisense oligodeoxynucleotide to the V1 subtype mRNA into the septum of male rats with osmotic minipumps and measured behavioral, cellular and molecular parameters. Compared to vehicle and scrambled-sequence oligo controls, chronic antisense administration for up to 4 d diminished the ability of the animals to distinguish a previously exposed juvenile from a novel one and to respond to exogenous AVP (1 ng/5 microliters, intracerebroventricular) with an improved Social memory. Furthermore, anxiety-related behavior was reduced. As measured in the behaviorally tested rats, antisense treatment resulted in a reduced binding of radiolabeled AVP in the septum, but not in other limbic brain areas (receptor autoradiography), and an increased amount of V1 receptor mRNA (reverse transcriptase PCR), indicating translational arrest and ongoing transcriptional activity. In sense oligo-treated rats, on the other hand, both the Social and the anxiety-related behavior scores lay between levels obtained in control and antisense-treated animals. These sense-treated rats showed a slightly reduced V1 receptor density in the septum and reduced receptor mRNA levels, indicating hybridization of the sense oligo to the DNA. The data show the potential of antisense targeting to further reveal relationships between local gene expression, neuropeptide-receptor interactions in distinct brain areas, and behavioral performance.
Michele D Kipke - One of the best experts on this subject based on the ideXlab platform.
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use. Language: en
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use.
Caroly F Wong - One of the best experts on this subject based on the ideXlab platform.
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use. Language: en
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harassment Discrimination violence and illicit drug use among young men who have sex with men
Aids Education and Prevention, 2010Co-Authors: Caroly F Wong, George Ayala, George Weiss, Michele D KipkeAbstract:We examined the relationship among Social Discrimination, violence, and illicit drug use among an ethnically diverse cohort of young men who have sex with men (YMSM) residing in Los Angeles. Five Hundred twenty-six YMSM (aged 18-24 years) were recruited using a venue-based, stratified probability sampling design. Surveys assessed childhood financial hardship, violence (physical assault, sexual assault, intimate partner violence), Social Discrimination (homophobia and racism), and illicit drug use in the past 3 months. Analyses examined main and interaction effects of key variables on drug use. Experiences of financial hardship, physical intimate partner violence and homophobia predicted drug use. Although African American participants were less likely to report drug use than their Caucasian peers, those who experienced greater sexual racism were at significantly greater risk for drug use. Racial/ethnic minority YMSM were at increased risk for experiencing various forms of Social Discrimination and violence that place them at increased risk for drug use.
