254 research outputs found
Unannounced telephone pill counts for assessing varenicline adherence in a pilot clinical trial
Nia Thompson1, Niaman Nazir1, Lisa Sanderson Cox1,2, Babalola Faseru1,2, Kathy Goggin3, Jasjit S Ahluwalia4, Nicole L Nollen1,21University of Kansas School of Medicine, Department of Preventive Medicine and Public Health, Kansas City, KS, USA; 2University of Kansas Cancer Center, Kansas City, KS, USA; 3University of Missouri-Kansas City, Department of Psychology, Kansas City, MO, USA; 4University of Minnesota Medical School, Department of Medicine and Center for Health Equity, Minneapolis, MN, USABackground: Despite consistent evidence linking smoking cessation pharmacotherapy adherence to better outcomes, knowledge about objective adherence measures is lacking and little attention is given to monitoring pharmacotherapy use in smoking cessation clinical trials.Objectives: To examine unannounced telephone pill counts as a method for assessing adherence to smoking cessation pharmacotherapy.Research design: Secondary data analysis of a randomized pilot study.Participants: 46 moderate-to-heavy (>10 cigarettes per day) African-American smokers.Main measures: Smokers received 1 month of varenicline (Pfizer Global Pharmaceuticals, New York, NY) in a pill box at baseline. Unannounced pill counts were completed by telephone 4 days prior to an in-person pill count conducted at Month 1. At both counts, each compartment of the pill box was opened and the number of remaining pills was recorded.Results: Participants were a mean age of 48 years (SD = 13), predominately female (59%), low income (60% < $1800 monthly family income), and smoked an average of 17 (SD = 7) cigarettes per day. A high degree of concordance was observed between the number of pills counted by phone and in-person (rs = 0.94, P < 0.001). Participants with discordant counts (n = 7) had lower varenicline adherence (mean [SD] = 77% [18%] vs 95% [9%], P < 0.0005), but reported better medication adherence in the past (1.0 [0.8] vs 2.8 [1.0], P < 0.0004) than participants with matching phone and in-person counts (n = 39).Conclusion: Unannounced telephone pill counts appear to be a reliable and practical method for measuring adherence to smoking cessation pharmacotherapy.Keywords: medication adherence, African-Americans, smoking cessatio
The Role of Neighborhood Experiences in Psychological Distress among African American and White Smokers
Residential area characteristics and discrimination have been associated with psychological distress. Differences in these relationships across racial groups are not well understood. We examined the relative role of perceived discrimination, neighborhood problems, and neighborhood cohesion/trust in explaining differences in psychological distress (indicated by anxiety and depressive symptoms) between 224 African American and 225 white smokers (income ≤ 400% federal poverty level) in a smoking cessation intervention study. Surveys were linked to US census tract data. We conducted random intercept Poisson multilevel regression models and examined interactions between race and neighborhood experiences. African Americans had greater risk of anxiety and depressive symptoms and greater individual and neighborhood disadvantage than whites. Controlling for objective neighborhood characteristics, when perceived discrimination and perceived neighborhood characteristics were added to the regression models, the association between anxiety symptoms and race were no longer statistically significant; the association between depressive symptoms and race decreased, but remained statistically significant. Lower neighborhood social cohesion/trust and greater neighborhood problems increased depressive symptoms for African Americans, but not for whites. Perceived discrimination and neighborhood social cohesion/trust outweighed the importance of race in explaining anxiety symptoms. These findings underscore the need for multilevel interventions addressing social and environmental contexts
Plasmodium knowlesi Genome Sequences from Clinical Isolates Reveal Extensive Genomic Dimorphism.
Plasmodium knowlesi is a newly described zoonosis that causes malaria in the human population that can be severe and fatal. The study of P. knowlesi parasites from human clinical isolates is relatively new and, in order to obtain maximum information from patient sample collections, we explored the possibility of generating P. knowlesi genome sequences from archived clinical isolates. Our patient sample collection consisted of frozen whole blood samples that contained excessive human DNA contamination and, in that form, were not suitable for parasite genome sequencing. We developed a method to reduce the amount of human DNA in the thawed blood samples in preparation for high throughput parasite genome sequencing using Illumina HiSeq and MiSeq sequencing platforms. Seven of fifteen samples processed had sufficiently pure P. knowlesi DNA for whole genome sequencing. The reads were mapped to the P. knowlesi H strain reference genome and an average mapping of 90% was obtained. Genes with low coverage were removed leaving 4623 genes for subsequent analyses. Previously we identified a DNA sequence dimorphism on a small fragment of the P. knowlesi normocyte binding protein xa gene on chromosome 14. We used the genome data to assemble full-length Pknbpxa sequences and discovered that the dimorphism extended along the gene. An in-house algorithm was developed to detect SNP sites co-associating with the dimorphism. More than half of the P. knowlesi genome was dimorphic, involving genes on all chromosomes and suggesting that two distinct types of P. knowlesi infect the human population in Sarawak, Malaysian Borneo. We use P. knowlesi clinical samples to demonstrate that Plasmodium DNA from archived patient samples can produce high quality genome data. We show that analyses, of even small numbers of difficult clinical malaria isolates, can generate comprehensive genomic information that will improve our understanding of malaria parasite diversity and pathobiology
Discrete cilia modelling with singularity distributions
We discuss in detail techniques for modelling flows due to finite and infinite arrays of beating cilia. An efficient technique, based on concepts from previous ‘singularity models’ is described, that is accurate in both near and far-fields. Cilia are modelled as curved slender ellipsoidal bodies by distributing Stokeslet and potential source dipole singularities along their centrelines, leading to an integral equation that can be solved using a simple and efficient discretisation. The computed velocity on the cilium surface is found to compare favourably with the boundary condition. We then present results for two topics of current interest in biology. 1) We present the first theoretical results showing the mechanism by which rotating embryonic nodal cilia produce a leftward flow by a ‘posterior tilt,’ and track particle motion in an array of three simulated nodal cilia. We find that, contrary to recent suggestions, there is no continuous layer of negative fluid transport close to the ciliated boundary. The mean leftward particle transport is found to be just over 1 μm/s, within experimentally measured ranges. We also discuss the accuracy of models that represent the action of cilia by steady rotlet arrays, in particular, confirming the importance of image systems in the boundary in establishing the far-field fluid transport. Future modelling may lead to understanding of the mechanisms by which morphogen gradients or mechanosensing cilia convert a directional flow to asymmetric gene expression. 2) We develop a more complex and detailed model of flow patterns in the periciliary layer of the airway surface liquid. Our results confirm that shear flow of the mucous layer drives a significant volume of periciliary liquid in the direction of mucus transport even during the recovery stroke of the cilia. Finally, we discuss the advantages and disadvantages of the singularity technique and outline future theoretical and experimental developments required to apply this technique to various other biological problems, particularly in the reproductive system
Disparities and risks of sexually transmissible infections among men who have sex with men in China: a meta-analysis and data synthesis.
BACKGROUND: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. METHODS: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. RESULTS: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5-11.0%) for chlamydia, 1.5% (0.7-2.9%) for genital wart, 1.9% (1.3-2.7%) for gonorrhoea, 8.9% (7.8-10.2%) for hepatitis B (HBV), 1.2% (1.0-1.6%) for hepatitis C (HCV), 66.3% (57.4-74.1%) for human papillomavirus (HPV), 10.6% (6.2-17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2-5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4-4.7), 5.7 (2.7-12.3), and 2.2 (1.4-3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. CONCLUSION: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. TRIAL REGISTRATION: PROSPERO NO: CRD42013003721
Revealing Dissociable Attention Biases in Chronic Smokers Through an Individual-Differences Approach
Addiction is accompanied by attentional biases (AB), wherein drug-related cues grab attention
independently of their perceptual salience. AB have emerged in different flavours depending on
the experimental approach, and their clinical relevance is still debated. In chronic smokers we
sought evidence for dissociable attention abnormalities that may play distinct roles in the clinical
manifestations of the disorder. Fifty smokers performed a modified visual probe-task measuring two
forms of AB and their temporal dynamics, and data on their personality traits and smoking history/
status were collected. Two fully dissociable AB effects were found: A Global effect, reflecting the overall
impact of smoke cues on attention, and a Location-specific effect, indexing the impact of smoke cues
on visuospatial orienting. Importantly, the two effects could be neatly separated from one another
as they: (i) unfolded with dissimilar temporal dynamics, (ii) were accounted for by different sets of
predictors associated with personality traits and smoking history and (iii) were not correlated with one
another. Importantly, the relevance of each of these two components in the single individual depends
on a complex blend of personality traits and smoking habits, a result that future efforts addressing the
clinical relevance of addiction-related AB should take into careful consideration.This study was supported by funding provided by the University of Verona to CDL, CC and L
Fine-mapping the CYP2A6 regional association with nicotine metabolism among African American smokers
The nicotine metabolite ratio (NMR; 3’hydroxycotinine/cotinine) is a stable biomarker for CYP2A6 enzyme activity and nicotine clearance, with demonstrated clinical utility in personalizing smoking cessation treatment. Common genetic variation in the CYP2A6 region is strongly associated with NMR in smokers. Here, we investigated this regional association in more detail. We evaluated the association of CYP2A6 single-nucleotide polymorphisms (SNPs) and * alleles with NMR among African American smokers (N = 953) from two clinical trials of smoking cessation. Stepwise conditional analysis and Bayesian fine-mapping were undertaken. Putative causal variants were incorporated into an existing African ancestry-specific genetic risk score (GRS) for NMR, and the performance of the updated GRS was evaluated in both African American (n = 953) and European ancestry smokers (n = 933) from these clinical trials. Five independent associations with NMR in the CYP2A6 region were identified using stepwise conditional analysis, including the deletion variant CYP2A6*4 (beta = −0.90, p = 1.55 × 10−11). Six putative causal variants were identified using Bayesian fine-mapping (posterior probability, PP = 0.67), with the top causal configuration including CYP2A6*4, rs116670633, CYP2A6*9, rs28399451, rs8192720, and rs10853742 (PP = 0.09). Incorporating these putative causal variants into an existing ancestry-specific GRS resulted in comparable prediction of NMR within African American smokers, and improved trans-ancestry portability of the GRS to European smokers. Our findings suggest that both * alleles and SNPs underlie the association of the CYP2A6 region with NMR among African American smokers, identify a shortlist of variants that may causally influence nicotine clearance, and suggest that portability of GRSs across populations can be improved through inclusion of putative causal variants
Kernel bandwidth optimization in spike rate estimation
Kernel smoother and a time-histogram are classical tools for estimating an instantaneous rate of spike occurrences. We recently established a method for selecting the bin width of the time-histogram, based on the principle of minimizing the mean integrated square error (MISE) between the estimated rate and unknown underlying rate. Here we apply the same optimization principle to the kernel density estimation in selecting the width or “bandwidth” of the kernel, and further extend the algorithm to allow a variable bandwidth, in conformity with data. The variable kernel has the potential to accurately grasp non-stationary phenomena, such as abrupt changes in the firing rate, which we often encounter in neuroscience. In order to avoid possible overfitting that may take place due to excessive freedom, we introduced a stiffness constant for bandwidth variability. Our method automatically adjusts the stiffness constant, thereby adapting to the entire set of spike data. It is revealed that the classical kernel smoother may exhibit goodness-of-fit comparable to, or even better than, that of modern sophisticated rate estimation methods, provided that the bandwidth is selected properly for a given set of spike data, according to the optimization methods presented here
Design, baseline characteristics, and retention of African American light smokers into a randomized trial involving biological data
<p>Abstract</p> <p>Background</p> <p>African Americans experience significant tobacco-related health disparities despite the fact that over half of African American smokers are light smokers (use ≤10 cigarettes per day). African Americans have been under-represented in smoking cessation research, and few studies have evaluated treatment for light smokers. This paper describes the study design, measures, and baseline characteristics from <it>Kick It at Swope III </it>(KIS-III), the first treatment study of bupropion for African American light smokers.</p> <p>Methods</p> <p>Five hundred forty African American light smokers were randomly assigned to receive bupropion (150mg bid) (n = 270) or placebo (n = 270) for 7 weeks. All participants received written materials and health education counseling. Participants responded to survey items and provided blood samples for evaluation of phenotype and genotype of CYP2A6 and CYP2B6 enzymes involved in nicotine and bupropion metabolism. Primary outcome was cotinine-verified 7-day point prevalence smoking abstinence at Week 26 follow-up.</p> <p>Results</p> <p>Of 2,628 individuals screened, 540 were eligible, consented, and randomized to treatment. Participants had a mean age of 46.5 years and 66.1% were women. Participants smoked an average of 8.0 cigarettes per day, had a mean exhaled carbon monoxide of 16.4ppm (range 1-55) and a mean serum cotinine of 275.8ng/ml. The mean Fagerström Test for Nicotine Dependence was 3.2, and 72.2% of participants smoked within 30 minutes of waking. The average number of quit attempts in the past year was 3.7 and 24.2% reported using pharmacotherapy in their most recent quit attempt. Motivation and confidence to quit were high.</p> <p>Conclusion</p> <p>KIS-III is the first study designed to examine both nicotine and bupropion metabolism, evaluating CYP2A6 and CYP2B6 phenotype and genotype in conjunction with psychosocial factors, in the context of treatment of African American light smokers. Of 1629 smokers screened for study participation, only 18 (1.1%) were ineligible to participate in the study because they refused blood draws, demonstrating the feasibility of recruiting and enrolling African American light smokers into a clinical treatment trial involving biological data collection and genetic analyses. Future evaluation of individual factors associated with treatment outcome will contribute to advancing tailored tobacco use treatment with the goal of enhancing treatment and reducing health disparities for African American light smokers.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="URL">NCT00666978</a></p
Community health needs assessment with precede-proceed model: a mixed methods study
<p>Abstract</p> <p>Background</p> <p>Community health services in China have developed over the last few decades. In order to use limited health resources more effectively, we conducted a community health needs assessment. This aimed to provide an understanding of the community's health problems and the range of potential factors affecting risk behaviours for the priority health problems.</p> <p>Methods</p> <p>We used the precede-proceed model for the needs assessment. Triangulation of data, methods and researchers were employed in data collection.</p> <p>Results</p> <p>Main findings include: cardiovascular diseases (CVDs) were identified as the priority health problems in the study communities; risk factors associated with CVDs included smoking, physical inactivity and unhealthy eating behaviours, particularly amongst male residents with low education level; factors negatively affecting behaviours were classified into predisposing factors (limited knowledge, beliefs and lack of perceived needs), enabling factors (limited access to health promotion activities, unawareness of health promotion, lack of work-site and school health promotion, absence of health promotion related policy) and reinforcing factors (culture). Policies and organization were not perfect; there were limited staff skilled in providing health promotion in the community.</p> <p>Conclusion</p> <p>CVDs were identified by the communities as priority health problems. Future health programs should focus on smoking, physical inactivity and unhealthy eating behaviours. Behaviour change strategies should take predisposing factors, enabling factors and reinforcing factors into consideration. Policies, organization and human resource need strengthening.</p
- …