Biomedical subjects

Sherry C Wang

Publications and source records attributed to Sherry C Wang.

4 recordsLinked to original sources

PubMed2006

Do good things come to those who drink? A longitudinal investigation of drinking expectancies and hazardous alcohol use in female college athletes.

PURPOSE: To prospectively examine the link between positive and negative drinking expectancies and hazardous alcohol use, and to explore the reciprocal associations between expectancies and hazardous use among female college athletes. METHOD: Participants were part of a larger (n = 189), ongoing longitudinal study on female athletes' socialization experiences and health behaviors from an all-women's college in the Northeastern United States. The sample for the present study were 85 college-aged (17-22 years) female students (Mean age = 19.6) who indicated alcohol use in the past year and provided data at both time points (baseline and one year later). Respondents completed self-report questionnaires on their age, hazardous alcohol use, and expectations about the effects of drinking. RESULTS: Logistic regression analyses showed that positive drinking expectancies predicted increased odds of hazardous alcohol use at baseline and one year later (even after controlling for baseline hazardous use). Positive expectancies accounted for a higher proportion of variance in predicting increased odds of hazardous alcohol use at both time points than did negative expectancies. Bivariate correlational analyses examining the bi-directional associations between expectancies and hazardous alcohol use also revealed some indication that positive expectancies were associated with hazardous alcohol use rather than vice-versa. No such relations emerged for negative expectancies. CONCLUSIONS: Findings shed light on the utility of positive expectancies in predicting concurrent and subsequent hazardous alcohol use among female student-athletes. Future research directions and potential implications for prevention efforts are discussed.

Adolescent↗

PubMed2005

The bacterial nucleoid: a highly organized and dynamic structure.

Recent advances in bacterial cell biology have revealed unanticipated structural and functional complexity, reminiscent of eukaryotic cells. Particular progress has been made in understanding the structure, replication, and segregation of the bacterial chromosome. It emerged that multiple mechanisms cooperate to establish a dynamic assembly of supercoiled domains, which are stacked in consecutive order to adopt a defined higher-level organization. The position of genetic loci on the chromosome is thereby linearly correlated with their position in the cell. SMC complexes and histone-like proteins continuously remodel the nucleoid to reconcile chromatin compaction with DNA replication and gene regulation. Moreover, active transport processes ensure the efficient segregation of sister chromosomes and the faithful restoration of nucleoid organization while DNA replication and condensation are in progress.

Bacteria↗

PubMed2004

The topoisomerase IV ParC subunit colocalizes with the Caulobacter replisome and is required for polar localization of replication origins.

The process of bacterial DNA replication generates chromosomal topological constraints that are further confounded by simultaneous transcription. Topoisomerases play a key role in ensuring orderly replication and partition of DNA in the face of a continuously changing DNA tertiary structure. In addition to topological constraints, the cellular position of the replication origin is strictly controlled during the cell cycle. In Caulobacter crescentus, the origin of DNA replication is located at the cell pole. Upon initiation of DNA replication, one copy of the duplicated origin sequence rapidly appears at the opposite cell pole. To determine whether the maintenance of DNA topology contributes to the dynamic positioning of a specific DNA region within the cell, we examined origin localization in cells that express temperature-sensitive forms of either the ParC or ParE subunit of topoisomerase (Topo) IV. We found that in the absence of active Topo IV, replication initiation can occur but a significant percent of replication origins are either no longer moved to or maintained at the cell poles. During the replication process, the ParC subunit colocalizes with the replisome, whereas the ParE subunit is dispersed throughout the cell. However, an active ParE subunit is required for ParC localization to the replisome as it moves from the cell pole to the division plane during chromosome replication. We propose that the maintenance of DNA topology throughout the cell cycle contributes to the dynamic positioning of the origin sequence within the cell.

Base Sequence↗

PubMed2002

Dynamic localization of proteins and DNA during a bacterial cell cycle.

A cellular differentiation programme that culminates in an asymmetric cell division is an integral part of the cell cycle in the bacterium Caulobacter crescentus. Recent work has uncovered mechanisms that ensure the execution of many events at different times during the cell cycle and at specific places in the cell. Surprisingly, in this one-micron bacterial cell, the dynamic spatial disposition of regulatory proteins, structural proteins and specific regions of the chromosome are important components of both cell-cycle progression and the generation of daughter cells with different cell fates.

Bacterial Proteins↗