Sexting,Substance Use,and Sexual Risk Behavior in Young Adults

PurposeCell phone use has become more widespread over the past decade. Young adults are frequently early adopters of new technologies, including cell phones. Most previous research examining sexting, the act of sending sexually explicit or suggestive images via text message, has focused on the legal or social consequences of this behavior. The current study focused on the public health implications of sexting by examining associations between sexting, substance use, and sexual risk behavior in youth.MethodsYoung adults (N = 763) completed online questionnaires assessing demographics, cell phone use (e.g., texting, sexting), substance use, and sexual risk behaviors.ResultsSexting was reported by a substantial minority of participants (44%). Compared with their nonsexting counterparts, participants who engaged in sexting were more likely to report recent substance use and high-risk sexual behaviors, including unprotected sex and sex with multiple partners. Of those who engaged in sexting, a considerable percentage (31.8%) reported having sex with a new partner for the first time after sexting with that person. In multivariate analyses, sexting was associated with high-risk sexual behavior, after accounting for demographic factors, total texting behaviors, and substance use.ConclusionsResults suggest that sexting is robustly associated with high-risk sexual behavior. Many individuals exchange explicit or provocative photos with long-term sexual partners, but at least some participants in this study were incurring new sexual risks after sexting. Additional research is needed to understand the contexts in which sexting occurs, motivations for sexting, and relationship of sexting to risk behavior.     

Does the perception of downloading speed influence the evaluation of web-based lectures?

Medical schools put little emphasis upon education on public health, even though public health has played an important role in this century. One way to harness its benefit in order to improve global health in the 21st century is to globally share lectures on public health through the Internet. We have developed the Supercourse comprising of web-based learning modules on epidemiology in a standardized format with the size of each web page less than 10 kilobytes. A cross-sectional observational study was conducted to investigate the association of the perception of the access speed to Web-based lectures by teachers with their perception of lecture quality. There were 223 teachers who rated the lectures: 72% were from North America or Western Europe, 40% had taught epidemiology, and 14% reported that the speed of access was slow. Odds ratio of above-average rating among those who reported that the speed of access was fast relative to those who reported that the speed of access was slow was 4.25 (2.03-8.91; P = 0.001). The odds ratios were similar and significant after taking into account several other factors, including the variation of rating across lectures, region, and experiences in teaching epidemiology. The results indicate that the perception of the quality of Web-based lectures is related to the speed of access to a web page. The speed of access may be as important, if not more important, as the content itself. This suggests that, to share educational materials on the Web globally for teachers, one must consider not only the content, but also how people at local sites gain access to the Internet.     

Ureolytic Biomineralization Reduces Proteus mirabilis Biofilm Susceptibility to Ciprofloxacin

Ureolytic biomineralization induced by urease-producing bacteria, particularly Proteus mirabilis, is responsible for the formation of urinary tract calculi and the encrustation of indwelling urinary catheters. Such microbial biofilms are challenging to eradicate and contribute to the persistence of catheter-associated urinary tract infections, but the mechanisms responsible for this recalcitrance remain obscure. In this study, we characterized the susceptibility of wild-type (ure+) and urease-negative (ure−) P. mirabilis biofilms to killing by ciprofloxacin. Ure+ biofilms produced fine biomineral precipitates that were homogeneously distributed within the biofilm biomass in artificial urine, while ure− biofilms did not produce biomineral deposits under identical growth conditions. Following exposure to ciprofloxacin, ure+ biofilms showed greater survival (less killing) than ure− biofilms, indicating that biomineralization protected biofilm-resident cells against the antimicrobial. To evaluate the mechanism responsible for this recalcitrance, we observed and quantified the transport of Cy5-conjugated ciprofloxacin into the biofilm by video confocal microscopy. These observations revealed that the reduced susceptibility of ure+ biofilms resulted from hindered delivery of ciprofloxacin into biomineralized regions of the biofilm. Further, biomineralization enhanced retention of viable cells on the surface following antimicrobial exposure. These findings together show that ureolytic biomineralization induced by P. mirabilis metabolism strongly regulates antimicrobial susceptibility by reducing internal solute transport and increasing biofilm stability.     

Biology and Therapy of Neoplastic Meningitis

Neoplastic meningitis (NM) occurs in 5% to 8% of cancer patients, commonly as an end-stage process in previously metastatic disease. As newer therapeutics extend patient survival by maintaining long-term control of systemic malignancies, the incidence of NM is likely to rise. This can be expected both because of a change in the natural history of the underlying disease and the generally poor penetrance of many newer anticancer drugs into the central nervous system, thereby creating a sanctuary site for malignant cells. Currently available treatments have provided limited benefit in overall survival in NM, although long-term survival does occur. Because of the morbidity occasionally associated with treatment, prognostic indicators are being analyzed to identify patients who may benefit from systemic and/or intrathecal therapy before making the decision to initiate treatment. Additionally, because of the relative insensitivity of traditional cerebrospinal fluid analysis, new markers of NM are being investigated. This endeavor is being aided by ongoing research into the underlying biology of the metastatic process.