Sleep disordered breathing in the paediatric population can manifest as an array of different systemic symptoms; among them is a distinct malocclusion and craniofacial phenotype. Emerging research suggests that the treatment of this malocclusion and/or craniofacial phenotype through orthodontic intervention may help with the symptoms of these patients. Selecting the patients who would benefit from orthodontic treatment can be a difficult task for the physician with minimal dental training. Therefore the aim of this study is to develop a simple index to be used by medical professionals to identify those paediatric patients with orthodontic treatment needs who may benefit their obstructive sleep apnoea (OSA) symptoms.
Methods and analysis
The methodology in this project has been devised through the WHO's recommendations on developing an index, with modifications based on the specific needs of this study. Based on the available literature, a draft index will be produced and subjected to multiple iterative revisions based on the feedback from: the Index Development Group, a group of multidisciplinary and internationally acclaimed experts in the field; the External Review Group, a group of potential end users and interested parties and the Steering Committee. Once the index has been formalised, it will be subjected to a pair of reliability tests using physicians and orthodontists scored 2 weeks apart. Subsequently, the index will be validated using dichotomous responses from orthodontists on whether they would treat a patient for OSA symptoms, and comparing the responses to the score of the index on the same patient.
Ethics and dissemination
The index will be translated into French and will be presented in orthodontic and medical conferences, workshops, seminars, round table discussions, and free copies for download will be made available on the website of the University of Alberta Interdisciplinary Airway Research Clinic (iarc.ualberta.ca). Furthermore, the index will be published in a peer-reviewed medical journal to further increase the exposure of the index.
PAEDIATRICS; HEALTH SERVICES ADMINISTRATION & MANAGEMENT
RNA-binding proteins mediate posttranscriptional functions in the circadian systems of multiple species. A conserved RNA recognition motif (RRM) protein encoded by the lark gene is postulated to serve circadian output and molecular oscillator functions in Drosophila and mammals, respectively. In no species, however, has LARK been eliminated, in vivo, to determine the consequences for circadian timing. The present study utilized RNA interference (RNAi) techniques in Drosophila to decrease LARK levels in clock neurons and other cell types in order to evaluate the circadian functions of the protein. Knockdown of LARK in timeless (TIM)– or pigment dispersing factor (PDF)–containing clock cells caused a significant number of flies to exhibit arrhythmic locomotor activity, demonstrating a requirement for the protein in pacemaker cells. There was no obvious effect on PER protein cycling in lark interference (RNAi) flies, but a knockdown within the PDF neurons was associated with increased PDF immunoreactivity at the dorsal termini of the small ventral lateral neuronal (s-LNv) projections, suggesting an effect on neuropeptide release. The expression of lark RNAi in multiple neurosecretory cell populations demonstrated that LARK is required within pacemaker and nonpacemaker cells for the manifestation of normal locomotor activity rhythms. Interestingly, decreased LARK function in the prothoracic gland (PG), a peripheral organ containing a clock required for the circadian control of eclosion, was associated with weak population eclosion rhythms or arrhythmicity.
clock output; posttranscriptional; RNA binding; locomotor activity; eclosion
Preclinical studies in aged, surgically-menopausal rhesus monkeys have revealed powerful benefits of intermittent estrogen injections on prefrontal cortex-dependent working memory, together with corresponding effects on dendritic spine morphology in the prefrontal cortex. This contrasts with the inconsistent effects of hormone therapy (HT) reported in clinical studies in women. Factors contributing to this discrepancy could include differences in the formulation and sequence of HT regimens, resulting in different neurobiological outcomes. The current study evaluated, in aging surgically menopausal rhesus monkeys, the cognitive effects of four HT regimens modeled directly on human clinical practice, including continuous estrogen treatment opposed by progesterone. None of the regimens tested produced any cognitive effect, despite yielding physiologically relevant serum hormone levels, as intended. These findings have implications for the design of regimens that might optimize the benefits of hormone treatment for healthy aging, and suggest that common HT protocols used by women may fail to result in substantial cognitive benefit, at least via direct effects on the prefrontal cortex.
ovarian hormones; aging; macaque; learning; memory; prefrontal; temporal
Amphitropic proteins, such as the virulence factor phosphatidylinositol-specific phospholipase C (PI-PLC) from Bacillus thuringiensis, often depend on lipid-specific recognition of target membranes. However, the recognition mechanisms for zwitterionic lipids such as phosphatidylcholine, which is enriched in the outer leaflet of eukaryotic cells, are not well understood. A 500 nanosecond long molecular dynamics simulation of PI-PLC at the surface of a lipid bilayer revealed a strikingly high number of interactions between tyrosines at the interfacial binding site and lipid choline groups with structures characteristic of cation-π interactions. Membrane affinities of PI-PLC tyrosine variants mostly tracked the simulation results, falling into two classes: (i) those with minor losses in affinity, Kd(mutant)/Kd(wildtype)≤5, and (ii) those where the apparent Kd was 50-200 times higher than wildtype. Estimating ΔΔG for these Tyr/PC interactions from the apparent Kd values reveals that the free energy associated with class I is ~1 kcal/mol, comparable to the value predicted by the Wimley-White hydrophobicity scale. In contrast, removal of class II tyrosines has a higher energy cost: ~2.5 kcal/mol towards pure PC vesicles. These higher energies correlate well with the occupancy of the cation-π adducts throughout the MD simulation. Together, these results strongly indicate that PI-PLC interacts with PC headgroups via cation-π interactions with tyrosine residues, and suggest that cation-π interactions at the interface may be a mechanism for specific lipid recognition by amphitropic and membrane proteins.
amphitropic membrane proteins; cation-π; molecular dynamics simulations; fluorescence correlation spectroscopy; phosphatidylinositol-specific phospholipase C (PI-PLC)
We examine overweight/obesity management in primary care in relation to body mass index (BMI), documentation of weight status, and comorbidities.
This analysis of baseline data from the Cholesterol Education and Research Trial included 2,330 overweight and obese adult primary care patients from southeastern New England. Data were obtained via a telephone interview and abstraction of subjects’ medical record. BMI (kg/m2) was calculated from measured height and weight. Management of overweight/obesity included advice to lose weight, physical activity recommendations, dietary recommendations, and referral for nutrition counseling.
Documentation of weight status was more common with increasing BMI (13% of overweight patients, 39% of mildly obese, and 77% of moderately/severely obese). Documentation of overweight/obesity was associated with increased behavioral treatment; the biggest increase was seen for advice to lose weight (ORs were 7.2 for overweight patients, 3.3 for patients with mild obesity, and 4.0 for moderate/severe obesity). While weight-related comorbidities were associated with increased overweight/obesity management at all BMIs, the biggest increase in odds was for patients with moderate/severe obesity.
Documentation of weight management was more common among patients with documented overweight/obesity and with weight-related comorbidities. These insights may help in designing new interventions in primary care setting for overweight and obese patients.
Trichomonas vaginalis is the most prevalent curable sexually transmitted infection in the United States and may lead to pre-term delivery, infertility, and increased HIV transmission. Incarcerated women may be at especially high risk for infection, although few studies have examined routine screening for Trichomonas infection in this population.
Women older than 18 years entering the Rhode Island Department of Corrections between September 2009 and May 2011 were recruited to participate. All women submitted a self-collected vaginal swab for APTIMA transcription-mediated amplification testing. Each participant completed a survey addressing demographics, symptoms, sexual behavior, and substance use by audio computer-assisted self-interview. Data analysis was completed using multivariate logistic regression in SAS.
Data for 387 women were analyzed. The mean age was 30 years, 60% were white, 18% were Hispanic, 10% were black, and 12% had other race/ethnicity. Forty-four percent reported vaginal symptoms, and 77% reported illicit drug and/or heavy alcohol use in the 30 days before incarceration. The prevalence of Trichomonas was 14% by APTIMA. The strongest predictors of infection included black race (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.9–13.4; P < 0.01), more than 1 year since last Papanicolaou test (OR, 2.5; 95% CI, 1.3–4.8; P < 0.01) and presence of vaginal symptoms (OR, 2.3; 95% CI, 1.2–4.7; P = 0.02).
Trichomonas infection is common in incarcerated women, especially among black women, women with vaginal symptoms, and those not receiving routine gynecologic care. Screening for Trichomonas infection in high-risk populations, particularly if using highly sensitive methods such as transcription-mediated amplification, may lead to increased detection and treatment.
This study investigated the prospective association between prenatal methamphetamine (MA) exposure and child behavioral problems at 5 years while also examining the home environment at 30 months and several primary caregiver (PC) risk factors. Participants were 97 MA-exposed and 117 comparison children and their PCs enrolled in the Infant Development, Environment and Lifestyle Study. Hypotheses were that child behaviors would be adversely impacted by (a) prenatal MA exposure, (b) home environments that provided less developmental stimulation and emotional responsiveness to the child, and (c) the presence of PC psychological symptoms and other risk factors. Prenatal MA exposure was associated with child externalizing behavioral problems at 5 years. Home environments that were more conducive to meeting children’s developmental and emotional needs were associated with fewer internalizing and externalizing behavioral problems. Independent of prenatal MA exposure, PC parenting stress and psychological symptoms were associated with increased child behavioral problems. Findings suggest prenatal MA exposure may contribute to externalizing behavioral problems in early childhood and the importance of considering possible vulnerabilities related to prenatal MA exposure in the context of the child’s caregiving environment.
infants; children; pregnant women; methamphetamine use; prenatal substance exposure; primary caregiver; caregiving environment; parenting stress
In the United States, tobacco use among prisoners is nearly three times that of the general population. While many American prisons and jails are now tobacco-free, nearly all inmates return to smoking as soon as they are released back into the community.
To better understand the role that personal relationships may play in enabling return to smoking, we enrolled former-smokers who were inmates in a tobacco-free prison. Baseline assessments were conducted six weeks prior to inmates’ scheduled release and included measures of smoking prior to incarceration, motivation, confidence and plans for remaining quit after release. We also assessed global social support (ISEL) and a measure of social support specific to quitting smoking (SSQ). Smoking status was assessed three weeks after prison release and included 7-day point-prevalence abstinence validated by urine cotinine, days to first cigarette and smoking rate.
A diverse sample comprised of 35% women, 20% Hispanic, and 29% racial minorities (average age 35.5 years) provided baseline data (n = 247). Over 90% of participants provided follow up data at 3-weeks post-release. Prior to incarceration participants had smoked an average of 21.5 (SD = 11.7) cigarettes per day. Only 29.2% had definite plans to remain smoking-abstinent after release. Approximately half of all participants reported that “most” or “all” of their family (42.2%) and friends (68%) smoked, and 58.8% reported their spouse or romantic partner smoked.
SSQ scores were not significantly predictive of smoking outcomes at three weeks, however, social support from family and friends were each significantly and positively correlated with motivation, confidence, and plans for remaining abstinent (all p values <0.05). These smoking-related attitudinal variables were significantly predictive of smoking outcomes (all p values <0.01). General social support (ISEL) was not associated with smoking-related attitudinal variables or smoking outcomes.
Inmates of smoke-free prisons have a head-start on being smoke-free for life. They have been abstinent well past the duration of nicotine withdrawal and have great financial incentive not to begin smoking again. However, this advantage may be offset by a lack of non-smoking role models among their family and friends, and perceived lack of support for remaining smoke-free.
ClinicalTrials.gov Identifier: NCT01684995
Smoking abstinence; Tobacco; Prison; Incarceration; Social support
Examine maternal and infant medical outcomes of prenatal exposure to methamphetamine (MA).
Four hundred and twelve mother-infant pairs (204 MA-exposed and 208 unexposed matched comparisons) were enrolled in the Infant Development, Environment and Lifestyle (IDEAL) study. Exposure was determined by maternal self-report during this pregnancy and/or positive meconium toxicology. Maternal interviews assessed prenatal drug use, pregnancy course, and sociodemographic information. Medical chart reviews provided medical history, obstetric complications, infant outcomes, and discharge placement.
MA-using mothers were more likely to be poor, to have a psychiatric disorder/emotional illness and less prenatal care, and to be less likely to breast-feed their infant than comparison mothers. After adjusting for covariates, MA-exposed infants were more likely to exhibit poor suck, to have smaller head circumferences and length, to require neonatal intensive care unit (NICU) admission, and to be referred to child protective services (CPS). Several outcomes previously reported from studies that lacked adequate control groups or adjustment for covariates were not significantly different in this study.
Prenatal MA exposure is associated with maternal psychiatric disorder/emotional illness, poor suck, NICU admission, and CPS involvement, and MA-exposed infants were less likely to be breast-fed; however, the absence of many serious complications, such as fetal distress, chronic hypertension, preeclampsia, placenta previa, abruptio placentae, and cardiac defects, suggests confounding variables influenced prior studies.
amphetamine; methamphetamine; drug; antenatal; neonate
This study evaluated how enrollment in special education services in 11 year old children relates to prenatal cocaine exposure, psychopathology, and other risk factors.
Participants were 498 children enrolled in The Maternal Lifestyle Study, a prospective, longitudinal, multisite study examining outcomes of children with prenatal cocaine exposure. Logistic regression was used to examine the effect of prenatal cocaine exposure and psychopathology on enrollment in an individualized education plan (a designation specific to children with special education needs), with environmental, maternal, and infant medical variables as covariates.
Prenatal cocaine exposure, an interaction of prenatal cocaine exposure and Oppositional Defiant Disorder, child Attention Deficit Hyperactivity Disorder, parent-reported internalizing behaviors, and teacher-reported externalizing behaviors, predicted enrollment in an individualized education plan. Other statistically significant variables in the model were male gender, low birth weight, being small for gestational age, white race, caregiver change, low socio-economic status, low child intelligence quotient, caregiver depression, and prenatal marijuana exposure.
Prenatal cocaine exposure increased the likelihood of receiving an individualized education plan with adjustment for covariates. Psychopathology also predicted this special education outcome, in combination with and independent of prenatal cocaine exposure.
cocaine; special education; behavior; prenatal substance exposure
Chronic obstructive pulmonary disease (COPD) is a progressive, debilitating disease associated with significant clinical burden and is estimated to affect 15 million individuals in the US. Although a large number of individuals are diagnosed with COPD, many individuals still remain undiagnosed due to the slow progression of the disorder and lack of recognition of early symptoms. Not only is there under-diagnosis but there is also evidence of sub-optimal evidence-based treatment of those who have COPD. Despite the development of international COPD guidelines, many primary care physicians who care for the majority of patients with COPD are not translating this evidence into effective clinical practice.
This paper describes the design and rationale for a randomized, cluster design trial (RCT) aimed at translating the COPD evidence-based guidelines into clinical care in primary care practices. During Phase 1, a needs assessment evaluated barriers and facilitators to implementation of COPD guidelines into clinical practice through focus groups of primary care patients and providers. Using formative evaluation and feedback from focus groups, three tools were developed. These include a computerized patient activation tool (an interactive iPad with wireless data transfer to the spirometer); a web-based COPD guideline tool to be used by primary care providers as a decision support tool; and a COPD patient education toolkit to be used by the practice team. During phase II, an RCT will be performed with one year of intervention within 30 primary care practices. The effectiveness of the materials developed in Phase I are being tested in Phase II regarding physician performance of COPD guideline implementation and the improvement in the clinically relevant outcomes (appropriate diagnosis and management of COPD) compared to usual care. We will also examine the use of a patient activation tool - ‘MyLungAge’ - to prompt patients at risk for or who have COPD to request spirometry confirmation and to request support for smoking cessation if a smoker.
Using a multi-modal intervention of patient activation and a technology-supported health care provider team, we are testing the effectiveness of this intervention in activating patients and improving physician performance around COPD guideline implementation.
COPD; Guidelines; Randomized Clinical Trial; Primary care
Staphylococcus aureus secretes a phosphatidylinositol-specific phospholipase C (PIPLC) as a virulence factor that is unusual in exhibiting higher activity at acidic pH values than other enzymes in this class. We have determined the crystal structure of this enzyme at pH 4.6 and pH 7.5. Under slightly basic conditions, the S. aureus PI-PLC structure closely follows the conformation of other bacterial PI-PLCs. However, when crystallized under acidic conditions, a large section of mobile loop at the αβ-barrel rim in the vicinity of the active site shows ~10 Å shift. This loop displacement at acidic pH is the result of a titratable intramolecular π-cation interaction between His258 and Phe249. This was verified by a structure of the mutant protein H258Y crystallized at pH 4.6, which does not exhibit the large loop shift. The intramolecular π-cation interaction for S. aureus PI-PLC provides an explanation for the activity of the enzyme at acid pH and also suggests how phosphatidylcholine, as a competitor for Phe249, may kinetically activate this enzyme.
Despite generally lower socioeconomic status and worse access to healthcare, Latinos have better overall health outcomes and longer life expectancy than non-Latino Whites. This “Latino Health Paradox” has been partially attributed to healthier cardiovascular (CV) behaviors among Latinos. However, as Latinos become more acculturated, differences in some CV behaviors disappear. This study aimed to explore how associations between acculturation and CV behaviors among Latinos vary by country of origin. Combined weighted data from the 2005 and 2007 California Health Interview Survey (CHIS) were used to investigate associations between acculturation level and CV behaviors among Latinos by country of origin. Among all Latinos, increased acculturation was associated with more smoking, increased leisure-time physical activity, and greater consumption of fast foods, but no change in fruit/vegetable and less soda intake. These trends varied, however, by Latino sub-groups from different countries of origin. Country of origin appears to impact associations between acculturation and CV behaviors among Latinos in complex ways.
Acculturation Cardiovascular behaviors Latinos Country of origin
Aged rhesus monkeys exhibit deficits in hippocampus-dependent memory, similar to aging humans. Here we explored the basis of cognitive decline by first testing young adult and aged monkeys on a standard recognition memory test (delayed nonmatching-to-sample test; DNMS). Next we quantified synaptic density and morphology in the hippocampal dentate gyrus (DG) outer (OML) and inner molecular layer (IML). Consistent with previous findings, aged monkeys were slow to learn DNMS initially, and they performed significantly worse than young subjects when challenged with longer retention intervals. Although OML and IML synaptic parameters failed to differ across the young and aged groups, the density of perforated synapses in the OML was coupled with recognition memory accuracy. Independent of chronological age, monkeys classified on the basis of menses data as peri/post-menopausal scored worse on DNMS, and displayed lower OML perforated synapse density, than pre-menopausal monkeys. These results suggest that naturally occurring reproductive senescence potently influences synaptic connectivity in the DG OML, contributing to individual differences in the course of normal cognitive aging.
delayed nonmatching-to-sample; disector method; estrogen; hippocampus; menopause; outer molecular layer; perforated synapse; post-synaptic density; recognition memory
Itaconic acid, or methylenesuccinic acid, is not generally classified as a mammalian metabolite. Using NMR based metabolomics and 13C-labeling, we have detected itaconic acid in both macrophage-like VM-M3 and RAW 264.7 tumor cell lines as well as stimulated and unstimulated primary murine macrophages. Macrophage activation by addition of lipopolysaccharide and IFN-γ markedly increased itaconic acid production and secretion. Crude cell extracts synthesize itaconic acid via decarboxylation of cis-aconitate, indicative of a novel mammalian cis-aconitic decarboxylase activity. Our results highlight a previously unidentified biosynthetic pathway related to TCA cycle metabolism in mammalian cells and a novel metabolite that likely plays a role in macrophage-based immune response.
metabolomics; NMR; LC-MS; itaconic acid; tumor cells; macrophages
Unplanned pregnancies and sexually transmitted infections (STIs) are important and costly public health problems in the United States resulting from unprotected sexual intercourse. Risk factors for unplanned pregnancies and STIs (poverty, low educational attainment, homelessness, substance abuse, lack of health insurance, history of an abusive environment, and practice of commercial sex work) are especially high among women with a history of incarceration. Project CARE (Contraceptive Awareness and Reproductive Education) is designed to evaluate an innovative intervention, Motivational Interviewing with Computer Assistance (MICA), aimed at enhancing contraceptive initiation and maintenance among incarcerated women who do not want a pregnancy within the next year and who are anticipated to be released back to the community. This study aims to: (1) increase the initiation of highly effective contraceptives while incarcerated; (2) increase the continuation of highly effective contraceptive use at 3, 6, 9, and 12 months after release; and (3) decrease unsafe sexual activity.
This randomized controlled trial will recruit 400 women from the Rhode Island Department of Corrections (RI DOC) women’s jail at risk for an unplanned pregnancy (that is, sexually active with men and not planning/wanting to become pregnant in the next year). They will be randomized to two interventions: a control group who receive two educational videos (on contraception, STIs, and pre-conception counseling) or a treatment group who receive two sessions of personalized MICA. MICA is based on the principles of the Transtheoretical Model (TTM) and on Motivational Interviewing (MI), an empirically supported counseling technique designed to enhance readiness to change targeted behaviors. Women will be followed at 3, 6, 9, and 12 months post release and assessed for STIs, pregnancy, and reported condom use.
Results from this study are expected to enhance our understanding of the efficacy of MICA to enhance contraceptive initiation and maintenance and reduce sexual risk-taking behaviors among incarcerated women who have re-entered the community.
Social isolation confers increased risk for coronary heart disease (CHD) events and mortality. In two recent studies, low levels of social integration among older adults were related to higher levels of C-reactive protein (CRP), a marker of inflammation, suggesting a possible biological link between social isolation and CHD. The current study examined relationships among social isolation, CRP, and 15-year CHD death in a community sample of US adults aged 40 years and older without a prior history of myocardial infarction. A nested case-cohort study was conducted from a parent cohort of community-dwelling adults from the southeastern New England region of the United States (N = 2,321) who were interviewed in 1989 and 1990. CRP levels were measured from stored sera provided by the nested case-cohort (n = 370), which included all cases of CHD death observed through 2005 (n = 48), and a random sample of non-cases. We found that the most socially isolated individuals had two-and-a-half times the odds of elevated CRP levels compared to the most socially integrated. In separate logistic regression models, both social isolation and CRP predicted later CHD death. The most socially isolated continued to have more than twice the odds of CHD death compared to the most socially integrated in a model adjusting for CRP and more traditional CHD risk factors. The current findings support social isolation as an independent risk factor of both high levels of CRP and CHD death in middle-aged adults without a prior history of myocardial infarction. Prospective study of inflammatory pathways related to social isolation and mortality are needed to fully delineate whether and how CRP or other inflammatory markers contribute to mechanisms linking social isolation to CVD health.
USA; social isolation; social integration; social support; inflammation; C-reactive protein; coronary heart disease; mortality
Little is known about the association between prenatal cocaine exposure and obesity. We tested whether prenatal cocaine exposure increases the likelihood of obesity in 561 9-year-old term children from the Maternal Lifestyle Study (MLS). Overall, 21.6% of children met criterion for obesity (body mass index [BMI] ≥ 95th percentile, age and sex-specific). While there was no overall cocaine effect on obesity, multivariate logistic analysis revealed that children exposed to cocaine but not alcohol were 4 times more likely to be obese (OR 4.11, CI 2.04–9.76) than children not exposed to either drug. No increase in obesity prevalence was found in children exposed to alcohol but not cocaine (OR 1.08, CI .59–1.93) or both (OR 1.21, CI 0.66–2.22). Alcohol exposure may attenuate the effect of cocaine exposure on obesity. Increased obesity associated with cocaine but not alcohol exposure was first observed at 7 years. BMI was also elevated from 3 to 9 years in children exposed to cocaine but not alcohol, due to increasing weight but normal height. Prenatal exposure to cocaine may alter the neuroendocrine system and metabolic processes resulting in increased weight gain and childhood obesity.
Prenatal cocaine exposure; prenatal alcohol exposure; childhood obesity; growth; fetal origins
One of the goals of the 2011 International Year of Chemistry is to celebrate the contributions of women to science. A question that has been frequently asked in this regard is... Why is it necessary to highlight women in the "age of equality"? The reasons are varied but the facts are that many women scientists worked in obscurity throughout the 19th and even well into the 20th century, sometimes publishing anonymously to be heard. This celebration of Women in Science is one way to recognize both the resiliency and passion of these women. As part of this celebration, Chemistry Central Journal's Thematic Series of "Women in Chemistry" includes this article describing the path several women took as they pursued chemistry careers spanning the latter part of the 20th century and into the early 21st century. Sharon Haynie, Nancy Jones, Cheryl Martin, Paula Olsiewski, Mary Roberts and Amber Hinkle each have unique story of their personal journey from childhood to adulthood. As you read these stories, listen generously, and feel free to share your own stories, comments and thoughts.
PTEN is an important control element of PI3K/AKT signaling involved in controlling the processes of embryonic development, cell migration and apoptosis. While its dysfunction is implicated in a large fraction of cancers, PTEN activity in the same pathway may also contribute to metabolic syndromes such as diabetes. In those cases, selective inhibitors of PTEN may be useful. A new class of chiral PTEN inhibitors based on the 3-deoxy-phosphatidylinositol derivatives was recently identified [Wang et al. (2008) J. Am. Chem. Soc. 130, 7746]. However, lack of detailed understanding of protein-ligand interactions has hampered efforts to develop effective agonists or antagonists of PTEN. Here, we use computational modeling to characterize the interactions of the diverse 3-deoxyphosphatidylinositol inhibitors with the PTEN protein. We show that, while each of the compounds binds with the inositol headgroup inserting into the proposed active site of the PTEN phosphatase domain, hydrogen bonding restrictions lead to distinct binding geometries for ligand pairs of opposite chirality. We furthermore demonstrate that the binding modes differ primarily in the orientation of acyl tails of the ligands and that the activity of the compounds is primarily controlled by the effectiveness of tail-protein contacts. These findings are confirmed by binding affinity calculations which are in good agreement with experiment. Finally, we show that while more potent D-series ligands bind in a manner similar to that of the native substrate, an alternate hydrophobic pocket suitable for binding the opposite chirality L-series inhibitors exists, offering the possibility of designing highly selective PTEN- targeting compounds.
PTEN; apoptosis; PI3K/AKT; molecular dynamics; cancer; phosphatidylinositol
We sought to determine the association between small for gestational age (SGA), birth weight, and childhood obesity within preterm polysubstance exposed children. We sampled 312 preterm children with 11-year body mass index (BMI; age- and sex-specific) data from the Maternal Lifestyle Study (51% girls, 21.5% SGA, 46% prenatal cocaine, and 55% tobacco exposed). Multinomial regression analyzed the association between 11-year obesity (OBE) and overweight (OW) and SGA, birth weight, first-year growth velocity, diet, and physical activity variables. Overall, 24% were OBE (BMI for age ≥95th percentile) and 16.7% were OW (BMI ≥85th and <95th percentiles). In adjusted analyses, SGA was associated with OW (odds ratio [OR]=3.4, confidence interval [CI] 1.5 to 7.5). Higher birth weight was associated with OBE (OR = 1.8, CI 1.3 to 2.4) and OW (OR=1.4, CI 1.1 to 2.0). Growth velocity was associated with OBE (OR=2.7, CI 1.8 to 4.0) and OW (OR=1.6, CI 1.1 to 2.4). Low exercise was associated with OBE (OR=2.1, CI 1.0 to 4.4) and OW (OR=2.1, CI 1.0 to 4.5). There was no effect of substance exposure on obesity outcomes. Many (41%) of these high-risk preterm 11-year-olds were obese/overweight. Multiple growth-related processes may be involved in obesity risk for preterm children, including fetal programming as indicated by the SGA effect.
Childhood obesity; premature birth; infant SGA; birth weight; exercise; prenatal drug exposure
Maximal oxygen uptake (VO2max), the gold standard for measurement of cardiorespiratory fitness, is frequently difficult to assess in overweight individuals due to physical limitations. Reactance and resistance measures obtained from bioelectrical impedance analysis (BIA) have been suggested as easily obtainable predictors of cardiorespiratory fitness, but the accuracy with which ht2/Z can predict VO2max has not previously been examined in overweight adolescents.
The impedance index was used as a predictor of VO2max in 87 overweight girls and 47 overweight boys ages 12 to 17 with mean BMI of 38.6 ± 7.3 and 42.5 ± 8.2 in girls and boys respectively. The Bland Altman procedure assessed agreement between predicted and actual VO2max.
Predicted VO2max was significantly correlated with measured VO2max (r2=0.48, p<0.0001). Using the Bland Altman procedure, there was significant magnitude bias (r2=0.10; p<0.002). The limits of agreement for predicted relative to actual VO2max were −589 to 574 mL O2/min.
The impedance index was highly correlated with VO2max in overweight adolescents. However, using BIA data to predict maximal oxygen uptake over-predicted VO2max at low levels of oxygen consumption and under-predicted VO2max at high levels of oxygen consumption. This magnitude bias, along with the large limits of agreement of BIA-derived predicted VO2max, limit its usefulness in the clinical setting for overweight adolescents.
Cycle ergometry; Obesity; Pediatrics; Physical Fitness; VO2max
A family history of later-onset breast cancer (FHLBC) may suggest multi-factorial inheritance of breast cancer risk, including unhealthy lifestyle behaviors that may be shared within families. We assessed whether adherence to lifestyle behaviors recommended for breast cancer prevention--including maintaining a healthful body weight, being physically active and limiting alcohol intake--modifies breast cancer risk attributed to FHLBC in postmenopausal women.
Breast cancer outcomes through August 2003 were analyzed in relationship to lifestyle and risk factors collected by questionnaire during enrollment (between 1993 and 1998) of 85,644 postmenopausal women into the Women's Health Initiative Observational Study.
During a mean follow-up of 5.4 years, 1997 women were diagnosed with invasive breast cancer. The rate of invasive breast cancer among women with an FHLBC who participated in all three behaviors was 5.94 per 1,000 woman-years, compared with 6.97 per 1,000 woman-years among women who participated in none of the behaviors. The rate among women with no FHLBC who participated in all three behavioral conditions was 3.51 per 1,000 woman-years compared to 4.67 per 1,000 woman-years for those who participated in none. We did not observe a clinically important departure from additive effects (Interaction Contrast: 0.00014; 95% CI: -0.00359, 0.00388).
Participating in breast healthy behaviors was beneficial to postmenopausal women and the degree of this benefit was the same for women with and without an FHLBC.