Relatively few thermodynamic parameters are available for RNA triloops. Therefore, 24 stemloop sequences containing naturally occurring triloops were optically melted, and the thermodynamic parameters ΔH°, ΔS°, ΔG°3 7 , and T M for each stem-loop were determined. These new experimental values, on average, are 0.5 kcal/mol different from the values predicted for these triloops using the model proposed by Mathews et al. [Mathews, D. H., Disney, M. D., Childs, J. L., Schroeder, S. J., Zuker, M., and Turner, D. H. (2004) Proc. Natl. Acad. Sci. USA 101, 7287-7292]. The data for the 24 triloops reported here were then combined with the data for five triloops that were published previously. A new model was derived to predict the free energy contribution of previously unmeasured triloops. The average absolute difference between the measured values and the values predicted using this proposed model is 0.3 kcal/mol. These new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA stem-loops containing triloops, and, furthermore, should allow for improved prediction of secondary structure from sequence.RNA stem-loops containing three nucleotides in the loop, triloops, are common secondary structure motifs found in naturally occurring RNA. For example, bacterial 16S rRNAs strongly favor tetraloops; however, the UUU triloop is the most common replacement (1). In the 16S-like rRNA variable regions, triloops account for 7% of the loops in bacteria and 16% of the loops in eukaryotes (2). Triloops are also found in large subunit rRNAs (3,4), 5S rRNAs (5), signal recognition particles (6), RNase P RNAs (7), and group I introns (8,9). More specifically, triloops are found in Brome mosaic virus (+) strand RNA (10), human rhinovirus isotype 14 (11), iron responsive element RNA (12), and an RNA aptamer for bacteriophage MS2 coat protein (13), to name a few. Although relatively unstable due to the strain in the loop, triloops may be an important structural feature due to the accessibility of the loop nucleotides for recognition by proteins, other nucleic acids, or small molecules. It has been shown that triloops play a role in various biological processes, including virus replication (11,14), viral synthesis (15), and iron response (12), to name a few. Nevertheless, only a few studies have thermodynamically characterized RNA triloops (16)(17)(18)(19)(20), and only three of these (16-18) were done using 1 M NaCl (the salt concentration in which most nearest neighbor parameters are derived).The current model used by secondary structure prediction algorithms to predict the thermodynamic contribution of RNA triloops to stem-loop stability is sequence independent; all triloops contribute 5.4 kcal/mol to stem-loop stability, with the exception of 5'CCC3' which contributes 6.9 kcal/mol (21). In addition, there are two unstable triloops sequences (5'CAACG3' and 5'GUUAC3') for which this predictive model is not used; instead, the ΔG°3 7,loop values (6.8 and 6.9 kcal/mol, respecti...

No abstract

No abstract

Transfusion after pelvic reconstructive surgery is uncommon. The variables associated with transfusion are preoperative hematocrit <30%, American Society of Anesthesiologists class, bleeding disorders, nonwhite race, Hispanic ethnicity, and concomitant hysterectomy. Recognition of these factors can help guide preoperative counseling regarding transfusion risk after pelvic reconstructive surgery and individualize preoperative preparation.

Objectives The aim of this study was to evaluate the quality, readability, and accuracy of Web-based information regarding labiaplasty and to characterize the types of Web sites providing this information. Methods Investigators used 3 major search engines to query the internet using the search terms labiaplasty, labia reduction, and vaginal rejuvenation. Two validated tools were used to evaluate Web sites: the JAMA benchmark tool and the DISCERN instrument. Three physicians independently reviewed each Web site. Interrater agreement was assessed, and reviewer scores were averaged. Flesch-Kincaid reading ease and Flesch-Kincaid grade level of each site were assessed. Data were analyzed using Stata 14.0 (College Station, TX). Results Of the 112 Web sites reviewed, 100 Web sites were from North America, 9 from Europe, 2 from Australia, and 1 from Asia. The median score using the JAMA tool was 1.0 (0.33–4.0), indicating low accountability, whereas the median score using the DISCERN tool was 28 (18.7–77) of 80 with higher scores indicating higher quality. Cohen’s weighted κ statistic (0.81) demonstrated near perfect agreement among reviewers for DISCERN scores. The median reading level was 11.9 (6.4–19.5). A majority of the Web sites (92) were for-profit businesses or blogs. Conclusions The internet enables patients to research sensitive topics and seek answers without worry of social stigma. Online health-related information is a widely used yet poorly studied source of medical information. The majority of Web sites reviewed lack balanced, evidence-based information. Given the wide variation in the quality of information, physicians should guide patients to reputable online resources.

Objectives The objective of this study were (1) to assess the feasibility of using online platforms as recruitment tools for pelvic floor disorder studies and (2) to compare the prevalence of symptoms of incontinence and care-seeking behavior by online platform to previously published prevalence estimates. Methods We conducted a cross-sectional study among women to assess the prevalence of incontinence symptoms, level of bother, and care-seeking behavior. Participants were recruited through Facebook ads, ResearchMatch, or Reddit. The effectiveness of Facebook ads was assessed using the click through rate and an overall completion rate (number of completes over number of times an ad was shown). A nontargeted ad was posted to a Reddit thread in which research opportunities are advertised. For ResearchMatch, investigators sent a recruitment email. Effectiveness of this method was assessed by observing how many women completed the survey compared with the number of women who received it. Results Among the 7361 women who initiated the questionnaire, 6650 (90%) completed it. A majority of participants were recruited through ResearchMatch. Online platforms were successful in recruiting women across a wide age range (ages, 18–93 years). The overall prevalence of incontinence was 46.1% with women 45 years and older having the highest prevalence (64.6%). Common reasons for not seeking care included “not bothersome enough,” “other health problems,” and “being unsure about treatment.” Conclusions Internet-based recruitment was found to be feasible. The prevalence of incontinence was higher than has been reported in other population-based samples. Significant barriers to care exist, and further studies should focus on educational strategies.

No abstract

No abstract