The Epidemiology and Phenomenology of Non-Suicidal Self-Injurious Behavior Among Adolescents: A Critical Review of the Literature

This article critically reviewed the research addressing the epidemiology and phenomenology of non-suicidal self-injury (NSSI) among adolescents. Articles were identified through a search of Medline and Psychinfo. Findings indicate a lifetime prevalence of NSSI ranging from 13.0% to 23.2%. Reasons for engaging in NSSI include to regulate emotion and to elicit attention. Correlates of NSSI include a history of sexual abuse, depression, anxiety, alexithymia, hostility, smoking, dissociation, suicidal ideation, and suicidal behaviors. Suggested areas of future research include identifying the psychiatric diagnoses associated with NSSI among adolescents, determining the temporal link between NSSI and suicide attempts, learning more about the course of NSSI, understanding the biological underpinnings of NSSI, and identifying effective treatments for NSSI in adolescents.     

Decision making in patients with pulmonary nodules

Integrating current evidence with fundamental concepts from decision analysis suggests that management of patients with pulmonary nodules should begin with estimating the pretest probability of cancer from the patient's clinical risk factors and computed tomography characteristics. Then, the consequences of treatment should be considered, by comparing the benefits of surgery if the patient has lung cancer with the potential harm if the patient does not have cancer. This analysis determines the "treatment threshold," which is the point around which the decision centers. This varies widely among patients depending on their cardiopulmonary reserve, comorbidities, and individual preferences. For patients with a very low probability of cancer, careful observation with serial computed tomography is warranted. For those with a high probability of cancer, surgical diagnosis is warranted. For patients in the intermediate range of probabilities, either computed tomography-guided fine-needle aspiration biopsy or positron emission tomography, possibly followed by computed tomography-guided fine-needle aspiration biopsy, is best. Patient preferences should be considered because the absolute difference in outcome between strategies may be small. The optimal approach to the management of patients with pulmonary nodules is evolving as technologies develop. Areas of uncertainty include quantifying the hazard of delayed diagnosis; determining the optimal duration of follow-up for ground-glass and semisolid opacities; establishing the roles of volumetric imaging, advanced bronchoscopic technologies, and limited surgical resections; and calculating the cost-effectiveness of different strategies.     

The educational value of online mastery quizzes in a human anatomy course for first-year dental students

The purpose of this study was to evaluate the effectiveness of online mastery quizzes in enhancing dental students' learning and preparedness for anatomy examinations. First-year dental students taking an integrated anatomy course at The Ohio State University were administered online mastery quizzes, made available for five days before each examination. The mastery quizzes were comprised of ten multiple-choice questions representative of the upcoming examination in content and difficulty. The students were allowed to access this resource as many times as they desired during the five-day window before each examination; the highest score for each student was added to his or her final course grade. The results indicate that almost all the students took advantage of this resource to reinforce content, clarify concepts, and prepare for the examinations. Statistical analyses of the students' exam performance showed that the mastery quizzes neither improved nor reduced their exam scores, but multiple regression analyses showed that the initial mastery quiz scores had a predictive value for their examination performance, suggesting a potential for mastery quizzes as an intervention tool for such a course. Online mastery quizzes, when used effectively, may be an effective resource to further engage dental and other students in educational endeavors and examination preparation and as a predictor of success.     

Capsule enhances pneumococcal colonization by limiting mucus-mediated clearance

Expression of a polysaccharide capsule is required for the full pathogenicity of many mucosal pathogens such as Streptococcus pneumoniae. Although capsule allows for evasion of opsonization and subsequent phagocytosis during invasive infection, its role during mucosal colonization, the organism's commensal state, remains unknown. Using a mouse model, we demonstrate that unencapsulated mutants remain capable of nasal colonization but at a reduced density and duration compared to those of their encapsulated parent strains. This deficit in colonization was not due to increased susceptibility to opsonophagocytic clearance involving complement, antibody, or the influx of Ly-6G-positive cells, including neutrophils seen during carriage. Rather, unencapsulated mutants remain agglutinated within lumenal mucus and, thus, are less likely to transit to the epithelial surface where stable colonization occurs. Studies of in vitro binding to immobilized human airway mucus confirmed the inhibitory effect of encapsulation. Likewise, pneumococcal variants expressing larger amounts of negatively charged capsule per cell were less likely to adhere to surfaces coated with human mucus and more likely to evade initial clearance in vivo. Removal of negatively charged sialic acid residues by pretreatment of mucus with neuraminidase diminished the antiadhesive effect of encapsulation. This suggests that the inhibitory effect of encapsulation on mucus binding may be mediated by electrostatic repulsion and offers an explanation for the predominance of anionic polysaccharides among the diverse array of unique capsule types. In conclusion, our findings demonstrate that capsule confers an advantage to mucosal pathogens distinct from its role in inhibition of opsonophagocytosis--escape from entrapment in lumenal mucus.