NACHO permits functional heterologous expression of an insect homomeric α6 nicotinic acetylcholine receptor.

Insect nicotinic acetylcholine receptors (nAChR) are molecular targets of highly effective insecticides. The use of chaperone proteins has been key to successful functional expression of these receptors in heterologous systems, permitting functional and pharmacological studies of insect nAChRs with particular subunit composition. Here, we report the first use of the chaperone protein, NACHO, to enable functional expression of an insect nAChR, the α6 subunit from Apis mellifera, in Xenopus laevis oocytes. This is also the first report of functional expression of a homomeric insect α6 nAChR. Using two-electrode voltage-clamp electrophysiology we show that the acetylcholine EC50 of the α6 receptor is 0.88 µM and that acetylcholine responses are antagonized by α-bungarotoxin. Spinosad showed agonist actions and kept the ion channel open when co-applied with acetylcholine, reinforcing the α6 nAChR subunit as a key molecular target for the spinosyn class of insecticide. The use of NACHO may provide a basis for future expression studies of insect α6 nAChRs, potentially providing a tool for the discovery of novel insecticides.

The Apis mellifera alpha 5 nicotinic acetylcholine receptor subunit expresses as a homomeric receptor that is sensitive to serotonin.

Insect nicotinic acetylcholine receptors (nAChRs) are molecular targets of highly effective insecticides such as neonicotinoids. Functional expression of these receptors provides useful insights into their functional and pharmacological properties. Here, we report that the α5 nAChR subunit of the honey bee, Apis mellifera, functionally expresses in Xenopus laevis oocytes, which is the first time a homomeric insect nAChR has been robustly expressed in a heterologous system without the need for chaperone proteins. Using two-electrode voltage-clamp electrophysiology we show that the α5 receptor has low sensitivity to acetylcholine with an EC50 of 2.37 mM. However, serotonin acts as an agonist with a considerably lower EC50 at 119 µM that is also more efficacious than acetylcholine in activating the receptor. Molecular modelling indicates that residues in the complementary binding site may be involved in the selectivity towards serotonin. This is the first report of a ligand-gated ion channel activated by serotonin from an insect and phylogenetic analysis shows that the α5 subunit of A. mellifera and other non-Dipteran insects, including pest species, belong to a distinct subgroup of subunits, which may represent targets for the development of novel classes of insecticides.

Methodology of the Youth Risk Behavior Surveillance System--2013.

Priority health-risk behaviors (i.e., interrelated and preventable behaviors that contribute to the leading causes of morbidity and mortality among youths and adults) often are established during childhood and adolescence and extend into adulthood. The Youth Risk Behavior Surveillance System (YRBSS), established in 1991, monitors six categories of priority health-risk behaviors among youths and young adults: 1) behaviors that contribute to unintentional injuries and violence; 2) sexual behaviors that contribute to human immunodeficiency virus (HIV) infection, other sexually transmitted diseases, and unintended pregnancy; 3) tobacco use; 4) alcohol and other drug use; 5) unhealthy dietary behaviors; and 6) physical inactivity. In addition, YRBSS monitors the prevalence of obesity and asthma among this population. YRBSS data are obtained from multiple sources including a national school-based survey conducted by CDC as well as schoolbased state, territorial, tribal, and large urban school district surveys conducted by education and health agencies. These surveys have been conducted biennially since 1991 and include representative samples of students in grades 9-12. In 2004, a description of the YRBSS methodology was published (CDC. Methodology of the Youth Risk Behavior Surveillance System. MMWR 2004;53 [No RR-12]). Since 2004, improvements have been made to YRBSS, including increases in coverage and expanded technical assistance.This report describes these changes and updates earlier descriptions of the system, including questionnaire content; operational procedures; sampling, weighting, and response rates; data-collection protocols; data-processing procedures; reports and publications; and data quality. This report also includes results of methods studies that systematically examined how different survey procedures affect prevalence estimates. YRBSS continues to evolve to meet the needs of CDC and other data users through the ongoing revision of the questionnaire, the addition of new populations, and the development of innovative methods for data collection.

Repeated radiological procedures in the last 6 months of life in old age: a retrospective study.

OBJECTIVES: This novel study looks at the use of radiological procedures in an elderly cohort of patients in their last 6 months of life. Radiological imaging plays a central part of clinical investigations, but too many may override the judgement of benefits, risks and resources. There is little information on the burden of radiological procedures performed towards the end of life in patients of old age. METHODS: Data from every fourth patient aged 80 years and over who died between 4 July 2021 and 30 December 2021 in a National Health Service (NHS) hospital were collected. All radiological procedures performed within the last 6 months of the patients' life were recorded from clinical documentation and related to their age. RESULTS: 96 patients were studied with a total of 699 radiological procedures performed. When scaled up, costs of CT and MRI scans alone are conservatively estimated as £312 000/annum in patients aged ≥80 years in their last 6 months of life for a single medium-sized NHS hospital. CONCLUSIONS: A very large number of radiological procedures were performed towards the end of life among patients of old age. This is consistent with the national trend of increased medicalisation and poor recognition of dying.

Cyclic-AMP Increases Nuclear Actin Monomer Which Promotes Proteasomal Degradation of RelA/p65 Leading to Anti-Inflammatory Effects.

The second messenger, cAMP has potent immunosuppressive and anti-inflammatory actions. These have been attributed, in part, to the ability of cAMP-induced signals to interfere with the function of the proinflammatory transcription factor Nuclear Factor-kappa B (NF-κB). However, the mechanisms underlying the modulation of NF-κB activity by cAMP remain unclear. Here we demonstrate an important role for cAMP-mediated increase in nuclear actin monomer levels in inhibiting NF-κB activity. Elevated cAMP or forced expression of a nuclear localised polymerisation defective actin mutant (NLS-ActinR62D) inhibited basal and TNFα induced mRNA levels of NF-κB-dependent genes and NF-κB-dependent reporter gene activity. Elevated cAMP or NLS-ActinR62D did not affect NF-κB nuclear translocation but did reduce total cellular and nuclear RelA/p65 levels. Preventing the cAMP-induced increase in nuclear actin monomer, either by expressing a nuclear localised active mutant of the actin polymerising protein mDIA, silencing components of the nuclear actin import complex IPO9 and CFL1 or overexpressing the nuclear export complex XPO6, rescued RelA/p65 levels and NF-κB reporter gene activity in forskolin-stimulated cells. Elevated cAMP or NLS-ActinR62D reduced the half-life of RelA/p65, which was reversed by the proteasome inhibitor MG132. Accordingly, forskolin stimulated association of RelA/p65 with ubiquitin affinity beads, indicating increased ubiquitination of RelA/p65 or associated proteins. Taken together, our data demonstrate a novel mechanism underlying the anti-inflammatory effects of cAMP and highlight the important role played by nuclear actin in the regulation of inflammation.

Combined role for YAP-TEAD and YAP-RUNX2 signalling in substrate-stiffness regulation of cardiac fibroblast proliferation.

Cardiac fibrosis is associated with increased stiffness of the myocardial extracellular matrix (ECM) in part mediated by increased cardiac fibroblast proliferation However, our understanding of the mechanisms regulating cardiac fibroblast proliferation are incomplete. Here we characterise a novel mechanism involving a combined activation of Yes-associated protein (YAP) targets RUNX Family Transcription Factor 2 (RUNX2) and TEA Domain Transcription Factor (TEAD). We demonstrate that cardiac fibroblast proliferation is enhanced by interaction with a stiff ECM compared to a soft ECM. This is associated with activation of the transcriptional co-factor, YAP. We demonstrate that this stiffness induced activation of YAP enhances the transcriptional activity of both TEAD and RUNX2 transcription factors. Inhibition of either TEAD or RUNX2, using gene silencing, expression of dominant-negative mutants or pharmacological inhibition, reduces cardiac fibroblast proliferation. Using mutants of YAP, defective in TEAD or RUNX2 activation ability, we demonstrate a dual role of YAP-mediated activation of TEAD and RUNX2 for substrate stiffness induced cardiac fibroblast proliferation. Our data highlights a previously unrecognised role of YAP mediated RUNX2 activation for cardiac fibroblast proliferation in response to increased ECM stiffness.

'Biting the hand that feeds': fever and altered sensorium following a dog bite.

Capnocytophaga canimorsus infection is the most severe and rapidly progressive bacterial infection transmitted by dog bite and fortunately is very rare. The authors describe a 68-year-old gentleman who presented in an acute confusional state 2 days after having been bitten on the left hand by a dog. Despite immediate broad-spectrum intravenous antibiotics, he developed significant sequelae including disseminated intravascular coagulopathy, microvascular emboli leading to peripheral necrosis, widespread local tissue destruction and septic arthritis. Our case illustrates a life-threatening presentation of infection with C canimorsus, which is known as 'the dog bite organism'. Early diagnosis and aggressive treatment is key to survival.

Virtual visits in palliative care: about time or against the grain?

While the additional value from adding the option of virtual visits is not in question, numerous issues are raised around how to decide between face-to-face and virtual visits in individual cases and how best to set up such provision within an organisation. With only limited palliative care-specific literature and no time to set up and evaluate pilots, we had to get on and set up a prototype 'virtual visits' model, retro-fitting guidance and a supporting ethical framework. We looked at the issues spanning clinical, ethical and logistics domains; identifying areas of benefit as well as drawbacks, some specific to the rushed implementation because of COVID-19's infective risks and the 'rules' of lockdown, but many are generic areas to help guide longer term service design. Unsurprisingly, it appears clear that a 'one-size-fits-all' mentality is a poor fit for the individualised needs of the heterogeneous palliative care population. Virtual visits have great potential even if they are not a panacea.

Malaria and Dengue Mosquito Vectors from Lao PDR Show a Lack of the rdl Mutant Allele Responsible for Cyclodiene Insecticide Resistance.

The gamma-aminobutyric acid (GABA) receptor, RDL, plays important roles in neuronal signaling and is the target of highly effective insecticides. A mutation in RDL, commonly A296S, underlies resistance to several insecticides such as cyclodienes. Even though the use of cyclodienes has been banned, the occurrence of mutations substituting A296 is notably high in mosquitoes from several countries. Here, we report a survey investigating the prevalence of the Rdl mutant allele in mosquitoes from Laos, a country where mosquito-borne diseases such as malaria and dengue fever are health concerns. Anopheles and Aedes mosquitoes were collected from 12 provinces in Laos. Adult bioassays on Aedes aegypti (Linnaeus) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) showed that all the populations tested were susceptible to dieldrin (4%) following WHO protocols. Exon 7 from a total of 791 mosquitoes was sequenced to identify the amino acid encoded for at 296 of RDL. Only one of these mosquitoes, Anopheles maculatus rampae Harbach and Somboon (Diptera: Culicidae) from Attapeu, carried the mutant allele being heterozygous for A296S. We therefore found a general lack of the Rdl mutant allele indicating that mosquitoes from Laos are not exposed to insecticides that act on the GABA receptor compared to mosquitoes in several other countries. Identifying the prevalence of the Rdl mutation may help inform the potential use of alternative insecticides that act on the GABA receptor should there be a need to replace pyrethroids in order to prevent/manage resistance.

Pro-anorexia websites: what a clinician should know.

OBJECTIVE: The purpose of this study was to conduct a content analysis of the "Tips and Tricks" section of pro-ana websites to better understand information shared on these sites, and aide clinicians in identification, treatment, and prevention of anorexia. METHOD: Nine pro-ana websites were evaluated to identify categories of information in "Tips and Tricks." A content analysis was performed using emergent coding methods and 16 categories were determined. Reliability was acceptable (Cohen's Kappa = 0.702). Discrepancies were corrected by consensus. Frequencies of individual categories were computed. RESULTS: Most "Tips and Tricks" are directed at dieting/restricting calories (28.6%) and distraction (14.0%). Most disturbing, 11% of comments were directed at lying and concealing symptoms. DISCUSSION: Clinicians aware of "Tips and Tricks" might be better equipped to recognize the symptoms of anorexia early in treatment. Knowledge of "Tips and Tricks" can also facilitate better education, making it difficult for clients to conceal their illness.

Cloning and functional expression of intracellular loop variants of the honey bee (Apis mellifera) RDL GABA receptor.

The insect GABA receptor, RDL (resistance to dieldrin), plays central roles in neuronal signalling and is the target of several classes of insecticides. To study the GABA receptor from an important pollinator species, we cloned Rdl cDNA from the honey bee, Apis mellifera. Three Rdl variants were identified, arising from differential use of splice acceptor sites in the large intracellular loop between transmembrane regions 3 and 4. These variants were renamed from previously, as Amel_RDLvar1, Amel_RDLvar2 and Amel_RDLvar3. When expressed in Xenopus laevis oocytes, the three variants showed no difference in sensitivity to the agonist, GABA, with EC50s of 29µM, 20µM and 29µM respectively. Also, the potencies of the antagonists, fipronil and imidacloprid, were similar on all three variants. Fipronil IC50 values were 0.18µM, 0.31µM and 0.20µM whereas 100µM imidacloprid reduced the GABA response by 17%, 24% and 31%. The possibility that differential splicing of the RDL intracellular loop may represent a species-specific mechanism leading to insensitivity to insecticides is discussed.

Youth risk behavior surveillance--United States, 2005.

In the United States, 71% of all deaths among persons aged 10-24 years result from 4 causes: motorvehicle crashes, other unintentional injuries, homicide, and suicide. Results from the 2005 national Youth Risk Behavior Survey (YRBS) indicated that during the 30 days preceding the survey, many high school students engaged in behaviors that increased their likelihood of death from these 4 causes: 9.9% had driven a car or other vehicle when they had been drinking alcohol, 18.5% had carried a weapon, 43.3% had drunk alcohol, and 20.2% had used marijuana. In addition, during the 12 months preceding the survey, 35.9% of high school students had been in a physical fight and 8.4% had attempted suicide. Substantial morbidity and social problems among youth also result from unintended pregnancies and sexually transmitted diseases, including human immunodeficiency virus infection. During 2005, a total of 46.8% of high school students had ever had sexual intercourse, 37.2% of sexually active high school students had not used a condom at last sexual intercourse, and 2.1% had ever injected an illegal drug. Among adults aged > or =25 years, 61% of all deaths result from 2 causes: cardiovascular disease and cancer. Results from the 2005 national YRBS indicated that risk behaviors associated with these 2 causes of death were initiated during adolescence. During 2005, a total of 23.0% of high school students had smoked cigarettes during the 30 days preceding the survey, 79.9% had not eaten > or =5 times/day of fruits and vegetables during the 7 days preceding the survey, 67.0% did not attend physical education classes daily, and 13.1% were overweight.

Youth Risk Behavior Surveillance - United States, 2015.

PROBLEM: Priority health-risk behaviors contribute to the leading causes of morbidity and mortality among youth and adults. Population-based data on these behaviors at the national, state, and local levels can help monitor the effectiveness of public health interventions designed to protect and promote the health of youth nationwide. REPORTING PERIOD COVERED: September 2014-December 2015. DESCRIPTION OF THE SYSTEM: The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health behaviors among youth and young adults: 1) behaviors that contribute to unintentional injuries and violence; 2) tobacco use; 3) alcohol and other drug use; 4) sexual behaviors related to unintended pregnancy and sexually transmitted infections (STIs), including human immunodeficiency virus (HIV) infection; 5) unhealthy dietary behaviors; and 6) physical inactivity. In addition, YRBSS monitors the prevalence of obesity and asthma and other priority health behaviors. YRBSS includes a national school-based Youth Risk Behavior Survey (YRBS) conducted by CDC and state and large urban school district school-based YRBSs conducted by state and local education and health agencies. This report summarizes results for 118 health behaviors plus obesity, overweight, and asthma from the 2015 national survey, 37 state surveys, and 19 large urban school district surveys conducted among students in grades 9-12. RESULTS: Results from the 2015 national YRBS indicated that many high school students are engaged in priority health-risk behaviors associated with the leading causes of death among persons aged 10-24 years in the United States. During the 30 days before the survey, 41.5% of high school students nationwide among the 61.3% who drove a car or other vehicle during the 30 days before the survey had texted or e-mailed while driving, 32.8% had drunk alcohol, and 21.7% had used marijuana. During the 12 months before the survey, 15.5% had been electronically bullied, 20.2% had been bullied on school property, and 8.6% had attempted suicide. Many high school students are engaged in sexual risk behaviors that relate to unintended pregnancies and STIs, including HIV infection. Nationwide, 41.2% of students had ever had sexual intercourse, 30.1% had had sexual intercourse during the 3 months before the survey (i.e., currently sexually active), and 11.5% had had sexual intercourse with four or more persons during their life. Among currently sexually active students, 56.9% had used a condom during their last sexual intercourse. Results from the 2015 national YRBS also indicated many high school students are engaged in behaviors associated with chronic diseases, such as cardiovascular disease, cancer, and diabetes. During the 30 days before the survey, 10.8% of high school students had smoked cigarettes and 7.3% had used smokeless tobacco. During the 7 days before the survey, 5.2% of high school students had not eaten fruit or drunk 100% fruit juices and 6.7% had not eaten vegetables. More than one third (41.7%) had played video or computer games or used a computer for something that was not school work for 3 or more hours per day on an average school day and 14.3% had not participated in at least 60 minutes of any kind of physical activity that increased their heart rate and made them breathe hard on at least 1 day during the 7 days before the survey. Further, 13.9% had obesity and 16.0% were overweight. INTERPRETATION: Many high school students engage in behaviors that place them at risk for the leading causes of morbidity and mortality. The prevalence of most health behaviors varies by sex, race/ethnicity, and grade and across states and large urban school districts. Long-term temporal changes also have occurred. Since the earliest year of data collection, the prevalence of most health-risk behaviors has decreased (e.g., riding with a driver who had been drinking alcohol, physical fighting, current cigarette use, current alcohol use, and current sexual activity), but the prevalence of other behaviors and health outcomes has not changed (e.g., suicide attempts treated by a doctor or nurse, smokeless tobacco use, having ever used marijuana, and attending physical education classes) or has increased (e.g., having not gone to school because of safety concerns, obesity, overweight, not eating vegetables, and not drinking milk). Monitoring emerging risk behaviors (e.g., texting and driving, bullying, and electronic vapor product use) is important to understand how they might vary over time. PUBLIC HEALTH ACTION: YRBSS data are used widely to compare the prevalence of health behaviors among subpopulations of students; assess trends in health behaviors over time; monitor progress toward achieving 21 national health objectives for Healthy People 2020 and one of the 26 leading health indicators; provide comparable state and large urban school district data; and help develop and evaluate school and community policies, programs, and practices designed to decrease health-risk behaviors and improve health outcomes among youth.

Methodology of the youth risk behavior surveillance system.

CDC developed the Youth Risk Behavior Surveillance System (YRBSS) to monitor six categories of priority health-risk behaviors among youth--behaviors that contribute to unintentional injuries and violence; tobacco use; alcohol and other drug use; sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases, including human immunodeficiency virus (HIV) infection; unhealthy dietary behaviors; and physical inactivity--plus overweight. These risk behaviors contribute markedly to the leading causes of death, disability, and social problems among youth and adults in the United States. YRBSS includes a national school-based survey conducted by CDC as well as state, territorial, and local school-based surveys conducted by education and health agencies. In these surveys, conducted biennially since 1991, representative samples of students in grades 9--12 are drawn. In 2003, a total of 15,214 students completed the national survey, and 32 states and 20 school districts also obtained data representative of their jurisdiction. Although multiple publications have described certain methodologic features of YRBSS, no report has included a comprehensive description of the system and its methodology. This report describes the background and rationale for YRBSS and includes a detailed description of the methodologic features of the system, including its questionnaire; operational procedures; sampling, weighting, and response rates; data-collection protocols; data-processing procedures; reports and publications; and data quality. YRBSS is evolving to meet the needs of CDC and other users of the data.

Come hither. Recruiting today's disillusioned medical residents.

It seems that one-fourth of today's medical residents would choose another field if they had their education to do over again. Why the disillusionment with medicine? This article discusses the reasons and offers guidelines for recruiting young physicians who approach employment with uncertainty, skepticism and priorities that differ from those of the previous generation.

Youth risk behavior surveillance - United States, 2011.

PROBLEM: Priority health-risk behaviors, which are behaviors that contribute to the leading causes of morbidity and mortality among youth and adults, often are established during childhood and adolescence, extend into adulthood, and are interrelated and preventable. REPORTING PERIOD COVERED: September 2010-December 2011. DESCRIPTION OF THE SYSTEM: The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health-risk behaviors among youth and young adults: 1) behaviors that contribute to unintentional injuries and violence; 2) tobacco use; 3) alcohol and other drug use; 4) sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infection; 5) unhealthy dietary behaviors; and 6) physical inactivity. In addition, YRBSS monitors the prevalence of obesity and asthma. YRBSS includes a national school-based Youth Risk Behavior Survey (YRBS) conducted by CDC and state and large urban school district school-based YRBSs conducted by state and local education and health agencies. This report summarizes results from the 2011 national survey, 43 state surveys, and 21 large urban school district surveys conducted among students in grades 9-12. RESULTS: Results from the 2011 national YRBS indicated that many high school students are engaged in priority health-risk behaviors associated with the leading causes of death among persons aged 10-24 years in the United States. During the 30 days before the survey, 32.8% of high school students nationwide had texted or e-mailed while driving, 38.7% had drunk alcohol, and 23.1% had used marijuana. During the 12 months before the survey, 32.8% of students had been in a physical fight, 20.1% had ever been bullied on school property, and 7.8% had attempted suicide. Many high school students nationwide are engaged in sexual risk behaviors associated with unintended pregnancies and STDs, including HIV infection. Nearly half (47.4%) of students had ever had sexual intercourse, 33.7% had had sexual intercourse during the 3 months before the survey (i.e., currently sexually active), and 15.3% had had sexual intercourse with four or more people during their life. Among currently sexually active students, 60.2% had used a condom during their last sexual intercourse. Results from the 2011 national YRBS also indicate many high school students are engaged in behaviors associated with the leading causes of death among adults aged ≥ 25 years in the United States. During the 30 days before the survey, 18.1% of high school students had smoked cigarettes and 7.7% had used smokeless tobacco. During the 7 days before the survey, 4.8% of high school students had not eaten fruit or drunk 100% fruit juices and 5.7% had not eaten vegetables. Nearly one-third (31.1%) had played video or computer games for 3 or more hours on an average school day. INTERPRETATION: Since 1991, the prevalence of many priority health-risk behaviors among high school students nationwide has decreased. However, many high school students continue to engage in behaviors that place them at risk for the leading causes of morbidity and mortality. Variations were observed in many health-risk behaviors by sex, race/ethnicity, and grade. The prevalence of some health-risk behaviors varied substantially among states and large urban school districts. PUBLIC HEALTH ACTION: YRBS data are used to measure progress toward achieving 20 national health objectives for Healthy People 2020 and one of the 26 leading health indicators; to assess trends in priority health-risk behaviors among high school students; and to evaluate the impact of broad school and community interventions at the national, state, and local levels. More effective school health programs and other policy and programmatic interventions are needed to reduce risk and improve health outcomes among youth.

'Biting the hand that feeds': fever and altered sensorium following a dog bite.

Capnocytophaga canimorsus infection is the most severe and rapidly progressive bacterial infection transmitted by dog bite and fortunately is very rare. The authors describe a 68-year-old gentleman who presented in an acute confusional state 2 days after having been bitten on the left hand by a dog. Despite immediate broad-spectrum intravenous antibiotics, he developed significant sequelae including disseminated intravascular coagulopathy, microvascular emboli leading to peripheral necrosis, widespread local tissue destruction and septic arthritis. Our case illustrates a life-threatening presentation of infection with C. canimorsus, which is known as 'the dog bite organism'. Early diagnosis and aggressive treatment is key to survival.

Youth risk behavior surveillance - United States, 2009.

PROBLEM: Priority health-risk behaviors, which are behaviors that contribute to the leading causes of morbidity and mortality among youth and adults, often are established during childhood and adolescence, extend into adulthood, and are interrelated and preventable. REPORTING PERIOD COVERED: September 2008- December 2009. DESCRIPTION OF THE SYSTEM: The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health-risk behaviors among youth and young adults: 1) behaviors that contribute to unintentional injuries and violence; 2) tobacco use; 3) alcohol and other drug use; 4) sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infection; 5) unhealthy dietary behaviors; and 6) physical inactivity. In addition, YRBSS monitors the prevalence of obesity and asthma. YRBSS includes a national school-based Youth Risk Behavior Survey (YRBS) conducted by CDC and state and local school-based YRBSs conducted by state and local education and health agencies. This report summarizes results from the 2009 national survey, 42 state surveys, and 20 local surveys conducted among students in grades 9-12. RESULTS: Results from the 2009 national YRBS indicated that many high school students are engaged in behaviors that increase their likelihood for the leading causes of death among persons aged 10-24 years in the United States. Among high school students nationwide, 9.7% rarely or never wore a seat belt when riding in a car driven by someone else. During the 30 days before the survey, 28.3% of high school students rode in a car or other vehicle driven by someone who had been drinking alcohol, 17.5% had carried a weapon, 41.8% had drunk alcohol, and 20.8% had used marijuana. During the 12 months before the survey, 31.5% of high school students had been in a physical fight and 6.3% had attempted suicide. Substantial morbidity and social problems among youth also result from unintended pregnancies and STDs, including HIV infection. Among high school students nationwide, 34.2% were currently sexually active, 38.9% of currently sexually active students had not used a condom during their last sexual intercourse, and 2.1% of students had ever injected an illegal drug. Results from the 2009 YRBS also indicated that many high school students are engaged in behaviors associated with the leading causes of death among adults aged >or=25 years in the United States. During 2009, 19.5% of high school students smoked cigarettes during the 30 days before the survey. During the 7 days before the survey, 77.7% of high school students had not eaten fruits and vegetables five or more times per day, 29.2% had drunk soda or pop at least one time per day, and 81.6% were not physically active for at least 60 minutes per day on all 7 days. One-third of high school students attended physical education classes daily, and 12.0% were obese. INTERPRETATION: Since 1991, the prevalence of many health-risk behaviors among high school students nationwide has decreased. However, many high school students continue to engage in behaviors that place them at risk for the leading causes of morbidity and mortality. The prevalence of most risk behaviors does not vary substantially among cities and states. PUBLIC HEALTH ACTION: YRBS data are used to measure progress toward achieving 15 national health objectives for Healthy People 2010 and three of the 10 leading health indicators, to assess trends in priority health-risk behaviors among high school students, and to evaluate the impact of broad school and community interventions at the national, state, and local levels. More effective school health programs and other policy and programmatic interventions are needed to reduce risk and improve health outcomes among youth.