Pharmacokinetics of levonorgestrel and etonogestrel in rat or minipig following intravenous, subcutaneous, or intradermal administration.

The objective of these studies was to determine the pharmacokinetics of levonorgestrel and etonogestrel in Sprague-Dawley rat or Göttingen minipig following various administration routes.Four sequential crossover studies were conducted: Study 1 administered levonorgestrel 30 µg intravenously and intradermally in four minipigs; Study 2 administered levonorgestrel 30 µg intravenously in 12 rats; Study 3 administered levonorgestrel 60 µg intravenously and subcutaneously in 12 rats; and Study 4 administered etonogestrel 30 µg intravenously in 12 rats. Samples were quantified using liquid chromatography-tandem mass spectrometry and pharmacokinetic parameters were estimated via noncompartmental analysis.Cmax and AUCinf for etonogestrel and levonorgestrel were similar following 30 µg intravenous bolus in rats, suggesting comparable pharmacokinetics. Levonorgestrel exposure was dose-proportional in rats, based on two-fold higher AUCinf following levonorgestrel 60 versus 30 µg. The bioavailability of intradermal and subcutaneous levonorgestrel was 97.7% (Study 1) and 90.3% (Study 3), respectively. The minipig levonorgestrel clearance was 21.5 L/hr, which was about 20-fold higher than both the rat levonorgestrel (range: 0.985-1.45 L/hr) and etonogestrel clearance (range: 0.803-0.968 L/hr).These studies contribute to the gap in knowledge of nonclinical levonorgestrel and etonogestrel pharmacokinetics, which is necessary for the ongoing development of long-acting reversible contraceptives.

Reported electronic cigarette use among adolescents in the Niagara region of Ontario.

BACKGROUND: Use of electronic cigarettes (e-cigarettes) among adolescents has not been fully described, in particular their motivations for using them and factors associated with use. We sought to evaluate the frequency, motivations and associated factors for e-cigarette use among adolescents in Ontario. METHODS: We conducted a cross-sectional study in the Niagara region of Ontario, Canada, involving universal screening of students enrolled in grade 9 in co-operation with the Heart Niagara Inc. Healthy Heart Schools' Program (for the 2013-2014 school year). We used a questionnaire to assess cigarette, e-cigarette and other tobacco use, and self-rated health and stress. We assessed household income using 2011 Canadian census data by matching postal codes to census code. RESULTS: Of 3312 respondents, 2367 answered at least 1 question in the smoking section of the questionnaire (1274 of the 2367 respondents [53.8%] were male, with a mean [SD] age of 14.6 [0.5] yr) and 2292 answered the question about use of e-cigarettes. Most respondents to the questions about use of e-cigarettes (n = 1599, 69.8%) had heard of e-cigarettes, and 380 (23.8%) of these respondents had learned about them from a store sign or display. Use of e-cigarettes was reported by 238 (10.4%) students. Most of the respondents who reported using e-cigarettes (171, 71.9%) tried them because it was "cool/fun/new," whereas 14 (5.8%) reported using them for smoking reduction or cessation. Male sex, recent cigarette or other tobacco use, family members who smoke and friends who smoke were strongly associated with reported e-cigarette use. Reported use of e-cigarettes was associated with self-identified fair/poor health rating (odds ratio [OR] 1.9 (95% confidence interval [CI] 1.2-3.0), p < 0.001), high stress level (OR 1.7 (95% CI 1.1-2.7), p < 0.001) and lower mean (33.4 [8.4] × $1000 v. 36.1 [10.7] × $1000, p = 0.001) and median [interquartile range] (26.2 [5.6] × $1000 v. 28.1 [5.7] × $1000) household incomes. INTERPRETATION: Use of e-cigarettes is common among adolescents in the Niagara region and is associated with sociodemographic features. Engaging in seemingly exciting new behaviours appears to be a key motivating factor rather than smoking cessation.

Universal screening for cardiovascular disease risk factors in adolescents to identify high-risk families: a population-based cross-sectional study.

BACKGROUND: Universal screening of children for dyslipidemia and other cardiovascular risk factors has been recommended. Given the clustering of cardiovascular risk factors within families, one benefit of screening adolescents may be to identify "at-risk" families in which adult members might also be at elevated risk and potentially benefit from medical evaluation. METHODS: Cross-sectional study of grade 9 students evaluating adiposity, lipids and blood pressure. Data collected by Heart Niagara Inc. through the Healthy Heart Schools' Program. Parents completed questionnaires, evaluating family history of dyslipidemia, hypertension, diabetes and early cardiovascular disease events in parents and siblings (first-degree relatives), and grandparents (second-degree relatives). Associations between positive risk factor findings in adolescents and presence of a positive family history were assessed in logistic regression models. RESULTS: N = 4014 adolescents ages 14-15 years were screened; 3467 (86 %) provided family medical history. Amongst adolescents, 4.7 % had dyslipidemia, 9.5 % had obesity, and 3.5 % had elevated blood pressure. Central adiposity (waist-to-height ratio ≥0.5) in the adolescent was associated with increased odds of diabetes in first- (OR:2.0 (1.6-2.6), p < 0.001) and second-degree relatives (OR:1.3 (1.1-1.6), p = 0.002). Dyslipidemia was associated with increased odds of diabetes (OR:1.6 (1.1-2.3), p < 0.001), hypertension (OR:2.2 (1.5-3.2), p < 0.001) and dyslipidemia (OR:2.2 (1.5-3.2),p < 0.001) in first degree relatives. Elevated blood pressure did not identify increased odds of a positive family history. CONCLUSIONS: Presence of obesity and/or dyslipidemia in adolescents identified through a universal school-based screening program is associated with risk factor clustering within families. Universal pediatric cardiometabolic screening may be an effective entry into reverse cascade screening.

Sleep disturbance and cardiovascular risk in adolescents.

BACKGROUND: Evidence suggests that inadequate or disturbed sleep is associated with increased cardiovascular risk in adults. There are limited data on sleep quality and associated cardiovascular risk in children. METHODS: We obtained data on adolescents from the 2009/10 cycle of the Healthy Heart Schools' Program, a population-based cross-sectional study in the Niagara region of Ontario. Participants underwent measurements of cardiometabolic risk factors, including body mass index (BMI), lipid profile and blood pressure, and they completed questionnaires measuring sleeping habits and nutritional status. We assessed sleep disturbance using the sleep disturbance score derived from the Pittsburgh Sleep Quality Index. We explored associations between sleeping habits and cardiovascular risk factors. RESULTS: Among 4104 adolescents (51% male), the mean hours of sleep per night (± standard deviation) were 7.9 ± 1.1 on weeknights and 9.4 ± 1.6 on weekends. In total, 19% of participants reported their sleep quality as fairly bad or very bad on weeknights and 10% reported it as fairly bad or very bad on weekends. In the multivariable regression models, a higher sleep disturbance score was associated with increased odds of being at high cardiovascular risk (highest v. lowest tertile odds ratio [OR] 1.43 [95% confidence interval (CI) 1.16-1.77], p < 0.001), increased odds of hypertension (highest v. lowest tertile OR 1.44 [95% CI 1.02-2.05], p = 0.05) and increased odds of elevated non-high density lipoprotein cholesterol (highest v. lowest tertile OR 1.28 [95% CI 1.00-1.64], p = 0.05). The mean duration of sleep was not associated with these outcomes. INTERPRETATION: In healthy adolescents, sleep disturbance is associated with cardiovascular risk factor abnormalities. Intervention strategies to optimize sleep hygiene early in life may be important for the prevention of cardiovascular disease.

Physical activity interacts with adiposity in determining cardiometabolic risk in adolescents.

BACKGROUND: Moderate-to-vigorous physical activity (MVPA) has been negatively associated with cardiometabolic risk. We sought to determine if MVPA interacts with body-mass index (BMI) and waist circumference (WC) in determining cardiometabolic risk in adolescents. METHODS: This cross-sectional study included cardiometabolic risk (blood pressure [BP], nonfasting lipids) screening and a 7-day recall physical activity questionnaire in 4,104 adolescents (51% male; mean age: 14.6 ± 0.5 years old). WC- and BMI- percentiles were used to define anthropometric categories (including obese adolescents: 90th WC, 85th BMI). RESULTS: Obesity in adolescents was associated with lower levels of high-density lipoprotein (HDL cholesterol (Estimate [EST]: -0.28(0.07) mmol/L, p < .001) and higher non-HDL cholesterol (EST: +0.38(0.14) mmol/L, p = .008). Each additional day with 20 min of MVPA was associated with lower non-HDL cholesterol (EST: -0.014(0.005) mmol/L/days/week, p = .003), independent of anthropometric category. Each additional day with 20 min of MVPA was associated with an increased odds ratio (OR) for higher BP category in obese adolescents (OR: 1.055, 95% CI: 1.028-1.084, p < .001) and a lower odds ratio for higher BP category in presumably-muscular adolescents (OR: 0.968, 95% CI: 0.934-0.989, p = .005). CONCLUSIONS: An increase in MVPA was associated with an increased likelihood for higher BP category in obese adolescents. The dose-response relationship between physical activity and cardiometabolic risk needs to be evaluated in adolescents of varying anthropometry categories.

Population trends toward increasing cardiovascular risk factors in Canadian adolescents.

OBJECTIVE: To determine prevalence and cross-sectional trends over time for cardiovascular risk factors in Canadian adolescents. STUDY DESIGN: Cross-sectional trends in cardiovascular risk and lifestyle factors were gathered annually in 14- to 15-year-old students in the Niagara region, Ontario, Canada. RESULTS: A total of 20 719 adolescents were screened between 2002 and 2008. The proportion of obese adolescents (>95th percentile for body mass index [BMI]) increased significantly, by +0.34%/year (P = .002). The proportions of adolescents with borderline high cholesterol (4.4-5.1 mmol/L) (+0.57%/year; P <.001) and with high cholesterol (≥5.2 mmol/L) (+0.43%/year; P <.001) both increased significantly over time. The proportion of adolescents with prehypertension decreased by -0.23%/year (P = .02), whereas the proportion of those with stage I hypertension (5%-6%) or stage II hypertension (2%-4%) remained constant. The proportion of adolescents classified as being at high cardiovascular risk increased by +0.67%/year (P <.001). Family history, low levels of physical activity, sedentary behaviors, poor nutrition, and lower socioeconomic status were all independently and negatively associated with all aspects of cardiovascular risk. CONCLUSIONS: A significant proportion of 14- to 15-year-old Canadian adolescents have at least one cardiovascular risk factor, and the cross-sectional trends worsened during the period 2002-2008.

A new hexaaminomacrocycle for ditopic binding of bromide.

A hexaaminomacrocycle L, containing four secondary and two tertiary amines has been synthesized and crystallized with hydrobromic acid. Structural analysis of the bromide complex suggests that the ligand in its tetrtaprotonated form, is involved in coordinating two bromides from both sides via hydrogen bonding interactions with N…Br(-) distance of 3,351 Å, forming a ditopic complex. The other two bromides are outside the cavity, and singly bonded to the macrocycle. The molecules are packed showing layer structures in which the internal bromides are locked between the layers of macrocycles. The bromide anions are coordinated alternatively by one and two hydrogen bonds with the protonated amines from the two adjacent macrocycles.

Evaluation of 18F-annexin V as a PET imaging agent in an animal model of apoptosis.

UNLABELLED: Annexin V is a 36-kDa protein that binds with high affinity to phosphatidylserine lipids in the cell membrane. Because one of the earliest measurable events in apoptosis is the eversion of phosphatidylserine from the inner membrane leaflet to the outer cell surface, annexin V has proven useful for detecting the earliest stages of apoptosis. METHODS: Annexin V was radiolabeled with 18F using N-succinimidyl-4-18F-fluorobenzoic acid chemistry, to a specific activity of 555-925 kBq/mug of protein. 18F-Annexin V (14.8-51.8 MBq) was administered intravenously to rats after pretreatment with cycloheximide (5 mg/kg) to induce liver apoptosis, and the injected rats were imaged by PET over 2 h. After imaging, rats were dissected and individual organs were weighed and counted. RESULTS: Pretreatment of rats with cycloheximide resulted in a 3- to 9-fold increase in uptake of 18F-annexin V in the liver of treated animals at 2 h, compared with controls. By morphologic analysis, treated livers showed a 3- to 6-fold higher level of apoptosis than controls, with higher levels also seen with longer exposure to cycloheximide. Terminal deoxynucleotide end-labeling (TUNEL) assays performed on liver slices showed that cycloheximide induced a 5- to 8-fold increase in the number of TUNEL-positive nuclei. These TUNEL results correlated with the uptake of 18F-annexin V in dissected liver tissue, with an r2 value of 0.89. Biodistribution analysis of normal rats showed highest uptake of 18F-annexin V in the kidneys and urinary bladder, indicating rapid renal clearance of 18F-annexin V metabolites. CONCLUSION: The PET data, the organ-specific uptake data from dissection, and the morphologic and TUNEL measures of apoptosis together indicate that 18F-annexin V binds specifically to apoptotic tissues in this model of chemically induced apoptosis in rat liver. The short physical half-life of 18F-annexin V and the rapid clearance of its metabolites to the urinary system suggest that 18F-annexin V will be useful in early assessment of the clinical response to cancer therapy in individual patients.

Lower socioeconomic status, adiposity and negative health behaviours in youth: a cross-sectional observational study.

OBJECTIVE: Understanding obesity and its modifiable risk factors in youth is key to addressing the burden of cardiovascular disease later in life. Our aim was to examine the associations among adiposity, negative health behaviours and socioeconomic status in youth from the Niagara Region. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional observational study of 3467 grade 9 students during their mandatory health and physical education class to investigate the association between socioeconomic status (postal code), self-reported health behaviour and adiposity in the Niagara Region, Ontario, Canada. RESULTS: Median household income was $63,696 and overall percentage below the after-tax low-income cut-off was 4.2%. Negative health behaviours (especially skipped meals, lower fruit and vegetable consumption, higher screen time) were associated with lower income neighbourhoods, however, the absolute effect was small. Those participants in the lowest income quintile had a significantly greater body mass index z-score than those in the highest (0.72±1.19 vs 0.53±1.12), but the overall trend across quintiles was not statistically significant. A similar trend was noted for waist-to-height ratio. The lowest income neighbourhoods according to after-tax low-income cut-off had small but statistically significant associations with higher adiposity compared with the middle or highest income neighbourhoods. CONCLUSIONS: Obesity prevention efforts should target modifiable behaviours, with particular attention to adolescents from lower income families and neighbourhoods.

Role of waist measures in characterizing the lipid and blood pressure assessment of adolescents classified by body mass index.

OBJECTIVE: To determine if the interaction of waist circumference percentile and waist to height ratio(WHtR) with body mass index (BMI) may serve to provide further risk specification in the lipid and blood pressure assessment of adolescents beyond BMI classification. DESIGN: Population-based, cross-sectional study. Data collected during the 2009-2010 academic school year. SETTING: Geographically and administratively defined Niagara Region, Ontario, Canada. Data collected in school, during subjects' mandatory physical education class. Part of the Heart Niagara Inc Healthy Heart Schools' Program. PARTICIPANTS: Entire population of grade 9 (14- and 15-year-old) students in the Niagara Region, Ontario.Four thousand eight hundred eighty-four students enrolled in grade 9 during the study period, of which 4104 participated (51% male) and 3248 (79%) had complete data. MAIN OUTCOME MEASURES: Nonfasting lipid values and blood pressure categories in subjects categorized based on BMI/waist circumference percentile and BMI/WHtR. RESULTS: The associations between blood pressure, lipid profile, and measures of adiposity (BMI alone, BMI/waist circumference percentile, and BMI/WHtR) were statistically significant but had a limited strength and were not statistically significant from each other. For overweight and obese subjects, increased WHtR categories were associated with worsened lipid profile and increased odds of hypertension both relative to subjects with both normal BMI and normal WHtR and subjects with normal WHtR within each BMI category. CONCLUSION: Waist measures should be included in the screening and assessment of overweight and obese adolescents.

Charge-assisted encapsulation of two chlorides by a hexaprotonated azamacrocycle.

A chloride complex of a hexaprotonated azamacrocycle has been isolated, and its structure has been determined by X-ray crystallography showing two encapsulated chloride anions in the cavity. The two internal guests are coordinated at two binding sites on the opposite side of the macrocycle through trigonal recognition by hydrogen-bonding interactions. The other four chlorides are located outside the cavity, each with a single hydrogen bond from secondary amines. Ab initio calculations based on density functional theory (DFT) suggest that the encapsulation of two chlorides inside the cavity leads to a significant charge transfer from the anions to the protonated amines.

Magnetic nanoparticles: inner ear targeted molecule delivery and middle ear implant.

Superparamagnetic iron oxide nanoparticles (SNP) composed of magnetite (Fe(3)O(4)) were studied preliminarily as vehicles for therapeutic molecule delivery to the inner ear and as a middle ear implant capable of producing biomechanically relevant forces for auditory function. Magnetite SNP were synthesized, then encapsulated in either silica or poly (D,L,-Lactide-co-glycolide) or obtained commercially with coatings of oleic acid or dextran. Permanent magnetic fields generated forces sufficient to pull them across tissue in several round window membrane models (in vitrocell culture, in vivo rat and guinea pig, and human temporal bone) or to embed them in middle ear epithelia. Biocompatibility was investigated by light and electron microscopy, cell culture kinetics, and hair cell survival in organotypic cell culture and no measurable toxicity was found. A sinusoidal magnetic field applied to guinea pigs with SNP implanted in the middle ear resulted in displacements of the middle ear comparable to 90 dB SPL.

Production of [F-18]fluoroannexin for imaging apoptosis with PET.

Recombinant human-annexin-V was conjugated with 4-[F-18]fluorobenzoic acid (FBA) via its reaction with the N-hydroxysuccinimidyl ester (FBA-OSu) at pH 8.5. A series of reactions using varying amounts of annexin-V, unlabeled FBA-OSu, and time produced products with different conjugation levels. Products were characterized by mass spectrometry and a cell-binding assay to assess the effect of conjugation. In each case, the conjugated protein was a mixture of proteins with a range of conjugation. Annexin-V could be conjugated with an average of two FBA mole equivalents without decreasing its affinity for red blood cells (K(d) 6-10 nM) with exposed phosphatidylserine. An average conjugation of 7.7 (range 3-13) diminished the binding 3-fold. Large-scale production and purification of [F-18]FBA-OSu from [F-18]fluoride was accomplished within 90 min and in 77% radiochemical yield (decay-corrected to the end of cyclotron bombardment). The conjugation reaction of annexin with [F-18]FBA-OSu was studied with respect to activity level, protein mass, and concentration. Under the most favorable conditions, >25 mCi [F-18]fluoroannexin (FAN) was isolated in 64% yield (decay-corrected for a 22 min conjugation process) from labeling 1.1 mg of annexin-V. A pilot PET imaging study of [F-18]fluoroannexin in normal rats showed high uptake in the renal excretory system and demonstrated sufficient clearance from most other internal organs within 1 h. [F-18]Fluoroannexin should prove useful in imaging targeted apoptosis.