Biomedical subjects

Michael Conway

Publications and source records attributed to Michael Conway.

4 recordsLinked to original sources

PubMed2006

Purification and 3D structural analysis of oligomeric human multidrug transporter ABCG2.

ABCG2 is a multidrug efflux pump associated with resistance of cancer cells to a plethora of unrelated drugs. ABCG2 is a "half-transporter," and previous studies have indicated that it forms homodimers and higher oligomeric species. In this manuscript, electron microscopic structural analysis directly addressed this issue. An N-terminal hexahistidine-tagged ABCG2(R482G) isoform was expressed to high levels in insect cells. An extensive detergent screen was employed to effect extraction of ABCG2(R482G) from membranes and identified only the fos-choline detergents as efficient. Soluble protein was purified to >95% homogeneity by a three-step procedure while retaining the ability to bind substrates. Cryonegative stain electron microscopy of purified ABCG2(R482G) provided 3D structural data at a resolution of approximately 18 A. Single-particle analysis revealed that the complex forms a tetrameric complex ( approximately 180 A in diameter x approximately 140 A high) with an aqueous central region. We interpret the tetrameric structure as comprising four homodimeric ABCG2(R482G) complexes.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

PubMed2006

Subjective impact, meaning making, and current and recalled emotions for self-defining memories.

Two studies examined the impact of self-defining events on individuals (i.e., subjective impact), meaning making with regard to these events, and how subjective impact may account for the pattern of current and recalled emotions for these self-defining memories (Singer & Moffitt, 1991-1992). In Study 1, participants recalled self-defining memories, indicating how much impact the recalled events have had on them and described meaning making for these events. Subjective impact was shown to be a good marker for meaning making. Participants in Study 2 each recalled five self-defining memories, reporting their current emotions about the events, the emotions they recalled feeling at the time, and the impact the events have had on them. As expected, for negative memories, people reported less negative emotion (e.g., sadness) and more positive emotion (e.g., pride) compared to how they recalled feeling at the time. For positive memories, people reported equally intense positive emotion (e.g., love) and less negative emotion (e.g., fear) compared to how they recalled feeling at the time. These patterns of current and recalled emotions were accounted for by impact ratings.

Adolescent↗

PubMed2004

Childhood and adult sexual abuse, rumination on sadness, and dysphoria.

OBJECTIVE: The study addressed the hypothesis that adults reporting sexual abuse are more likely to exhibit a general tendency to ruminate on sadness. The relations between reported abuse, rumination on sadness, and dysphoria were also examined. METHOD: Undergraduate students (101 women and 100 men) reported on childhood and adult sexual abuse and instances of intimidation, as well as completing the Rumination on Sadness Scale [Journal of Personality Assessment 75 (2000) 404] and the Beck Depression Inventory [Depression: Clinical, Experimental, and Theoretical Aspects, Harper & Row, New York]. RESULTS: Participants who reported more abuse were more likely to report rumination on sadness. Both reports of abuse and of rumination were linked to dysphoria. Overall, causal modeling indicated that two models were equally effective in accounting for the data: (a) victimization leads to dysphoria, with this relation being partly mediated by rumination and (b) victimization leads to dysphoria, which in turn leads to rumination. Both models are consistent with prior research. For men considered separately, both models were equally effective. For women, model a best accounted for the data. CONCLUSION: One of the pathways by which victimization may lead to depression in adulthood is by encouraging the development of a tendency to ruminate on sadness. Alternatively, victimization may lead to depression by other means, and the experienced depression or dysphoria may foster rumination.

Adult↗

PubMed2003

Gender differences in worry and associated cognitive-behavioral variables.

Research has shown that there is a significant gender difference in the worry report of women and men, with women often reporting more worry than men. The present study investigated this phenomenon by looking at gender differences in cognitive variables associated with worry; namely, intolerance of uncertainty, negative problem orientation, positive beliefs about worry, and cognitive avoidance. The sample consisted of 217 female and 100 male university students who completed six questionnaires assessing worry and associated cognitive variables. Women reported more worry than men on two measures of the tendency to worry, as well as more worries about lack of confidence issues. Women also reported a more negative problem orientation and engaging in more thought suppression, a type of cognitive avoidance. Thought suppression and negative orientation were found to make a significant contribution to the prediction of worry scores. Moreover, when both variables were controlled, the significant prediction of gender to worry disappeared. Hypotheses accounting for gender differences in thought suppression and negative problem orientation are discussed.

Adolescent↗