Roles for the Synechococcus elongatus RNA-Binding Protein Rbp2 in Regulating the Circadian Clock.

The cyanobacterial circadian oscillator, consisting of KaiA, KaiB, and KaiC proteins, drives global rhythms of gene expression and compaction of the chromosome and regulates the timing of cell division and natural transformation. While the KaiABC posttranslational oscillator can be reconstituted in vitro, the Kai-based oscillator is subject to several layers of regulation in vivo. Specifically, the oscillator proteins undergo changes in their subcellular localization patterns, where KaiA and KaiC are diffuse throughout the cell during the day and localized as a focus at or near the pole of the cell at night. Here, we report that the CI domain of KaiC, when in a hexameric state, is sufficient to target KaiC to the pole. Moreover, increased ATPase activity of KaiC correlates with enhanced polar localization. We identified proteins associated with KaiC in either a localized or diffuse state. We found that loss of Rbp2, found to be associated with localized KaiC, results in decreased incidence of KaiC localization and long-period circadian phenotypes. Rbp2 is an RNA-binding protein, and it appears that RNA-binding activity of Rbp2 is required to execute clock functions. These findings uncover previously unrecognized roles for Rbp2 in regulating the circadian clock and suggest that the proper localization of KaiC is required for a fully functional clock in vivo.

Update on the utilization of grafts in pelvic reconstruction surgeries.

PURPOSE OF REVIEW: Implanted grafts are increasingly used by pelvic reconstructive surgeons and gynecologists. In addition, the marketing of a variety of grafts has been aggressively expanded without scientific evidence to support their use. This review aims to provide an update of the current status and role of grafts in reconstructive pelvic surgery and to review the current knowledge of the biology of currently marketed synthetic and biologic grafts. RECENT FINDINGS: Xenografts are preferable to human tissue-banked grafts due to more predictable integrity. How these biomaterials compare to synthetics in terms of surgical outcomes has not been well studied, however. Absorbable materials that mimic some behaviors of synthetic and biological materials have been developed. Furthermore, several new techniques have been advocated with limited studies. SUMMARY: While the reduction of surgical failure rates in vaginal surgery is desirable, the addition of graft materials must demonstrate improvement in anatomical, functional, and quality of life outcomes over time. Furthermore, future complications due to improper placement or movement of a graft and the possible shrinkage of the graft are of concern. Therefore, significant research is necessary for the preclinical testing of materials, and expertise needs to be developed for the management of complications.

Newer pharmacologic options in management of overactive bladder syndrome.

PURPOSE OF REVIEW: Urinary incontinence is an under-reported epidemic that currently affects an estimated 13 million people in the United States, of whom about 11 million are women, according to the National Institute of Diabetes and Digestive and Kidney Diseases (Publication No. 02-4132). Because many patients are unaware of curative options and perceive it to be an inevitable outcome of advancing age, they fail to report their symptoms and increase their risk of developing associated co-morbid disease. Failure to diagnose and treat this condition increases financial burdens on individuals, their families and health care organizations. RECENT FINDINGS: Pharmacologic therapy of urge incontinence previously had limited treatment success because efficacious drugs were poorly tolerated, resulting in low patient compliance. Tolerance and effectiveness continue to be improved due to innovative new drugs and alternative delivery systems. SUMMARY: The goal of this review is to update the clinician on the efficacy and the tolerability of established and investigational pharmacologic modalities of therapy.