Nicotinic Receptor Alpha-5 Subunit Gene Polymorphism is Associated with Heavy Smoking Under a Range of Nicotine Dosing Conditions.

INTRODUCTION: This study aimed to assess the role of the rs16969968 variant of nicotinic receptor alpha-5 subunit in regulating smoking behavior and nicotine intake in response to nicotine manipulations among dependent smokers in a naturalistic environment. METHODS: Sixty-nine adults (19 females) smoking 10 or more cigarettes per day were asked to complete four 2-week study phases during which they smoked exclusively one of two types of Spectrum nicotine research cigarettes (FTC nicotine yield 0.8 and 1.6 mg, respectively), their usual brand of cigarettes, or their usual brand of cigarettes while wearing a 21-mg nicotine patch. Measurements included rs16969968 genotype, number of cigarettes per day, smoking topography, and plasma cotinine. RESULTS: Compared to controls (G/G carriers), A allele carriers reported smoking 4 to 5 more cigarettes per day across all conditions (all ps < .05). Mean total smoke volume per day and cotinine were greater in A allele carriers than in controls (ps = 0.05, 0.046, respectively). No significant genotype differences were found in smoking compensation indices for the switch from Medium to High nicotine yield cigarettes. Nicotine patch-induced reductions in cigarettes smoked per day and total smoke volume per day showed significant interactions between genotype and pre-patch levels, heavier smokers showing greater effects of genotype (p = .052 and p =.006, respectively). CONCLUSIONS: Results suggest that the rs16969968 variants regulate heaviness of smoking primarily by their impact on daily numbers of cigarettes smoked, but no genotype differences were found in smoking compensation after switching from Medium to High nicotine cigarettes. IMPLICATIONS: The differences in daily cigarette consumption between rs16969968 risk-allele carriers and controls are shown to be consistent regardless of manipulations of cigarette nicotine content and transdermal nicotine supplementation and markedly greater among dependent smokers than those observed in the general smoker populations. G/G allele carriers, relative to A allele carriers, appeared to be more sensitive to the nicotine patch manipulation, reducing their smoking to a greater extent. These findings support continued efforts in the development of personalized intervention strategies to reduce the rs16969968-conveyed genetic propensity for heavy smoking.

Patterns of Heart Failure Dyadic Illness Management: The Important Role of Gender.

BACKGROUND: The ways in which patients with heart failure (HF) and their care partners work together to manage HF are often overlooked. OBJECTIVE: The aim of this study was to identify and compare different patterns of HF dyadic illness management. METHODS: This was a secondary analysis of data on HF dyads. Heart failure management was measured using patient and care partner versions of the Self-Care of HF Index and European HF Self-care Behavior Scale. Latent class modeling was used to identify patterns of HF dyadic management. RESULTS: The mean age of the 62 patients and their care partners was 59.7 ± 11.8 and 58.1 ± 11.9 years, respectively. A majority of patients (71.0%) had class III/IV HF, and a majority of the couples (95.2%) were married. Two distinct dyadic patterns were observed, 1 collaborative management type (n = 42, 67.7%) and 1 autonomous management type (n = 20, 32.3%). Dyads in the autonomous pattern were mostly female patients with male care partners; patients in this pattern also were more anxious and depressed, and reported worse relationship quality compared with collaborative dyads. CONCLUSION: There is an engendered spectrum of collaboration in how HF patient-care partner dyads work together to manage HF that needs to be considered in clinical care and research.

Heart Failure Symptom Biology in Response to Ventricular Assist Device Implantation.

BACKGROUND: We have a limited understanding of the biological underpinnings of symptoms in heart failure (HF), particularly in response to left ventricular assist device (LVAD) implantation. OBJECTIVE: The aim of this study was to quantify the degree to which symptoms and biomarkers change in parallel from before implantation through the first 6 months after LVAD implantation in advanced HF. METHODS: This was a prospective cohort study of 101 patients receiving an LVAD for the management of advanced HF. Data on symptoms (dyspnea, early and subtle symptoms [HF Somatic Perception Scale], pain severity [Brief Pain Inventory], wake disturbance [Epworth Sleepiness Scale], depression [Patient Health Questionnaire], and anxiety [Brief Symptom Inventory]) and peripheral biomarkers of myocardial stretch, systemic inflammation, and hypervolumetric mechanical stress were measured before implantation with a commercially available LVAD and again at 30, 90, and 180 days after LVAD implantation. Latent growth curve and parallel process modeling were used to describe changes in symptoms and biomarkers and the degree to which they change in parallel in response to LVAD implantation. RESULTS: In response to LVAD implantation, changes in myocardial stretch were closely associated with changes in early and subtle physical symptoms as well as depression, and changes in hypervolumetric stress were closely associated with changes in pain severity and wake disturbances. Changes in systemic inflammation were not closely associated with changes in physical or affective symptoms in response to LVAD implantation. CONCLUSIONS: These findings provide new insights into the many ways in which symptoms and biomarkers provide concordant or discordant information about LVAD response.

Comparative symptom biochemistry between moderate and advanced heart failure.

BACKGROUND: We have a limited understanding of the biological underpinnings of symptoms in heart failure (HF). OBJECTIVES: The purpose of this paper was to compare relationships between peripheral biomarkers of HF pathogenesis and physical symptoms between patients with advanced versus moderate HF. METHODS: This was a two-stage phenotype sampling cohort study wherein we examined patients with advanced HF undergoing ventricular assist device implantation in the first stage, and then patients with moderate HF (matched adults with HF not requiring device implantation) in the second stage. Linear modeling was used to compare relationships among biomarkers and physical symptoms between cohorts. RESULTS: Worse myocardial stress, systemic inflammation and endothelial dysfunction were associated with worse physical symptoms in moderate HF (n=48), but less physical symptom burden in advanced HF (n=48). CONCLUSIONS: Where patients are in the HF trajectory needs to be taken into consideration when exploring biological underpinnings of physical HF symptoms.

Reproductive interference by male Drosophila subobscura on female D. persimilis: A laboratory experiment.

While females often reject courtship attempts by heterospecific males, reproductive interference by harassment from such males can nonetheless occur, potentially reducing female fitness. Such effects may be profound following a range expansion, when males from a new species may suddenly encounter (and perhaps even become abundant relative to) females of related native species. Drosophila subobscura recently invaded North America and may impact native species through reproductive interference and other processes. We test for the potential for reproductive interference by D. subobscura males on D. persimilis females in the laboratory. D. subobscura males aggressively copulated with D. persimilis females, including many females that exhibit rejection behaviors. Despite females attempting to dismount the males, the heterospecific copulations are on average longer than conspecific copulations, and females exhibit some reluctance to remate with conspecific males following this harassment. Females confined with both conspecific and heterospecific males produce fewer adult progeny than those with either conspecific males only or with conspecific males and distantly related D. simulans males that do not engage in female harassment. Overall, our results illustrate how reproductive interference by an invasive species can have negative effects on resident natural populations.