Hormone therapy and physical activity as predictors of lung cancer risk and survival: The California Teachers Study

Cigarette smoking is responsible for the majority of lung cancer cases worldwide; however, a proportion of never smokers still develop lung cancer over their lifetime, prompting investigation into additional factors that may modify lung cancer incidence, as well as mortality. Although hormone therapy (HT), physical activity (PA), and lung cancer have been previously examined, the associations remain unclear. This study investigated exposure to HT and PA that may modulate underlying mechanisms of lung cancer etiology and progression among women by using existing, de-identified data from the California Teachers Study (CTS).^ The CTS cohort, established in 1995–1996, has 133,479 active and retired female teachers and administrators, recruited through the California State Teachers Retirement System, and followed annually for cancer diagnosis, death, and change of address. Each woman enrolled in the CTS returned a questionnaire covering a wide variety of issues related to cancer risk and women's health, including recent and past HT use and physical activity, as well as active and environmental cigarette smoke exposure. Complete data to assess the associations between HT and lung cancer risk and survival were available for 60,592 postmenopausal women. Between 1995 and 2007, 727 of these women were diagnosed with invasive lung cancer; 441 of these died. Complete data to assess the associations between PA and lung cancer risk and survival were available for 118,513 women. Between 1995 and 2007, 853 of these women were diagnosed with invasive lung cancer; 516 of these died.^ After careful adjustment for smoking habits and other potential confounders, no measure of HT use was associated with lung cancer risk; however, any HT use (vs. no use) was associated with a decrease in lung-cancer-specific mortality. Specifically, among women who only used estrogen (E-only), decreases in lung cancer mortality were seen for recent use, but not for former use; no association was observed for estrogen plus progestin (E+P). Furthermore, among former users of HT, a statistically significant decrease in lung cancer mortality was observed for E-only use within 5 years prior to baseline, but not for E-only use >5 years prior to baseline. Neither long-term recreational PA nor recent recreational PA alone were associated with lung cancer risk; however, among women with a BMI<25 and ever smokers, high long-term moderate+strenuous PA was associated with a decrease in lung cancer risk. Women with non-local disease showed a decrease in lung cancer mortality associated with increasing duration of strenuous long-term activity, and 1.50-3.00 h/wk/y of recent moderate or recent strenuous PA. Long-term moderate PA was associated with decreased lung cancer mortality in never smokers, whereas recent moderate PA was associated with increased lung cancer mortality in current smokers. ^ Placing our findings in the context of the current literature, HT does not appear to be associated with lung cancer risk and previous studies reporting a protective effect of HT use on lung cancer risk may be subject to residual confounding by smoking. Looking at our findings regarding PA overall, the evidence still remains inconclusive regarding whether or not physical activity influence lung cancer risk or mortality. Our results suggest that recreational PA may associated with decreased lung cancer risk among women with BMI<25 and ever smoking-women; however, residual confounding by smoking should be strongly considered. To our knowledge, this is the first study to investigate lifetime recreational PA and lung cancer mortality among women. Our results contribute to the growing body of knowledge regarding non-smoking-related risk factors for lung cancer incidence and mortality among women. Given the potential clinical and interventional significance, further study and validation of these findings is warranted.^

Perceived risk and outcome expectancy on the practice of home infusion technique in a hemophilia population

This study described home infusion techniques and practices, measured the perceived risk of HIV and hepatitis transmission to self and others, and measured the outcome expectancy of following risk reduction guidelines for 90 hemophilia patients and/or their infusion assistants. It also assessed general knowledge of HIV and hepatitis information for the same population.^ The study subjects were hemophilia patients or their infusion assistants from the Gulf States Hemophilia Center in Houston, the El Paso Satellite Hemophilia Clinic in El Paso, or Texas members of the Women Outreach Network of the National Hemophilia Foundation (WONN) group. Each subject was interviewed either by telephone or in person. The questionnaire used was developed for the study and consisted of 60 items. These items assessed general demographics for the patients and assistants, including questions about their training to do infusions as well as the actual practices, measured perceived personal risk for the transmission of HIV or hepatitis to the assistants, perceived risk of transmission of HIV or hepatitis to others for assistants and self-infusers, and the outcome expectancy for following recommended risk reduction guidelines also for both groups.^ The theoretical framework used assumed that perceived risk and outcome expectancy would be predictive of behavior. The findings did not support this theory. Instead, the findings suggest that infusion behavior is habitual in nature; most respondents perform exactly the same behavior for every infusion. Since none of the variables selected were predictive of the compliance behavior for home infusion the teaching method should be directed towards mastery learning, or learning that will incorporate the correct behavior into a habitual pattern of home infusion. ^

Effect of primary care availability and health insurance coverage on risk and cost of Preventable Hospitalizations in Harris County

Preventable Hospitalizations (PHs) are hospitalizations that can be avoided with appropriate and timely care in the ambulatory setting and hence are closely associated with primary care access in a community. Increased primary care availability and health insurance coverage may increase primary care access, and consequently may be significantly associated with risks and costs of PHs. Objective. To estimate the risk and cost of preventable hospitalizations (PHs); to determine the association of primary care availability and health insurance coverage with the risk and costs of PHs, first alone and then simultaneously; and finally, to estimate the impact of expansions in primary care availability and health insurance coverage on the burden of PHs among non-elderly adult residents of Harris County. Methods. The study population was residents of Harris County, age 18 to 64, who had at least one hospital discharge in a Texas hospital in 2008. The primary independent variables were availability of primary care physicians, availability of primary care safety net clinics and health insurance coverage. The primary dependent variables were PHs and associated hospitalization costs. The Texas Health Care Information Collection (THCIC) Inpatient Discharge data was used to obtain information on the number and costs of PHs in the study population. Risk of PHs in the study population, as well as average and total costs of PHs were calculated. Multivariable logistic regression models and two-step Heckman regression models with log-transformed costs were used to determine the association of primary care availability and health insurance coverage with the risk and costs of PHs respectively, while controlling for individual predisposing, enabling and need characteristics. Predicted PH risk and cost were used to calculate the predicted burden of PHs in the study population and the impact of expansions in primary care availability and health insurance coverage on the predicted burden. Results. In 2008, hospitalized non-elderly adults in Harris County had 11,313 PHs and a corresponding PH risk of 8.02%. Congestive heart failure was the most common PH. PHs imposed a total economic burden of $84 billion at an average of $7,449 per PH. Higher primary care safety net availability was significantly associated with the lower risk of PHs in the final risk model, but only in the uninsured. A unit increase in safety net availability led to a 23% decline in PH odds in the uninsured, compared to only a 4% decline in the insured. Higher primary care physician availability was associated with increased PH costs in the final cost model (β=0.0020; p<0.05). Lack of health insurance coverage increased the risk of PH, with the uninsured having 30% higher odds of PHs (OR=1.299; p<0.05), but reduced the cost of a PH by 7% (β=-0.0668; p<0.05). Expansions in primary care availability and health insurance coverage were associated with a reduction of about $1.6 million in PH burden at the highest level of expansion. Conclusions. Availability of primary care resources and health insurance coverage in hospitalized non-elderly adults in Harris County are significantly associated with the risk and costs of PHs. Expansions in these primary care access factors can be expected to produce significant reductions in the burden of PHs in Harris County.^

Risk and resiliency: The untold story of youth in military families

Background: Risky sexual behaviors have been shown to increase the risk of unintended pregnancy and sexually transmitted infections (STIs) among youth. Youth in military families may be especially at risk for engaging in risky sexual behaviors because they are exposed to factors that are unique to the military culture, such as multiple relocations and parental deployment. However, data on sexual behaviors among military-dependent youth are limited and few studies have examined how these factors influence the sexual behaviors among youth. Purpose: The purpose of this dissertation was to estimate the prevalence of risky sexual behaviors among military-dependent youth and to describe how military factors may influence their sexual behaviors. Methods: Youth, aged 15–19 years, who attended a military health facility in the southern United States between June 2011 and September 2011 were recruited to complete a short, paper-based survey (N= 208, males and females) and to participate in an in-depth interview (N = 25, females). For quantitative data, prevalence estimates were computed and chi-square analyses were conducted. Logistic regression analyses were also conducted, adjusting for age, gender, and parents' duty status. For qualitative data, thematic coding of transcribed interviews was performed. Common and unique themes were examined across participants' experiences. Results: Over half of the youth was sexually experienced (53.7%). Parental deployment and number of relocations were significantly associated with having had sex in the past 3 months; however no significant associations were found between these military factors and other sexual behaviors. Although some youth felt that being a military-dependent had negatively impacted their sexual decisions, most believed the military experience had little influence on their sexual decisions. Most youth in military families also perceived having higher parental expectations to avoid risky behaviors, in general, than youth in civilian families. Conclusions: The majority of military-dependent youth are sexually experienced; however, individual and parental factors may have a greater role in sexual initiation among youth than military stressors do. The findings highlight the need for implementation of evidence-based strategies to prevent teen pregnancy and STIs at military installations. Future studies with larger sample sizes are needed to further explore how youth may cope with these military factors and the impact of parental factors on the sexual behaviors of youth.^

Risk and protective factors associated with depression among racial and ethnic mothers of adolescents

The central paradigm linking disadvantaged social status and mental health has been the social stress model (Horwitz, 1999), the assumption being that individuals residing in lower social status groups are subjected to greater levels of stress not experienced by individuals from higher status groups. A further assumption is that such individuals have fewer resources to cope with stress, in turn leading to higher levels of psychological disorder, including depression (Pearlin, 1989). Despite these key assumptions, there is a dearth of literature comparing the social patterning of stress exposure (Hatch & Dohrenwend, 2007; Meyer, Schwartz, & Frost, 2008; Kessler, Mickelson, & Williams, 1999; Turner & Avison, 2003; Turner & Lloyd, 1999; Turner, Wheaton, & Lloyd, 1995), and the distribution and contribution of protective factors, posited to play a role in the low rates of depression found among African- and Latino-Americans (Alegria et al., 2007; Breslau, Aguilar-Gaxiola, Kendler, Su, Williams, & Kessler, 2006; Breslau, Borges, Hagar, Tancredi, Gilman, 2009; Gavin, Walton, Chae, Alegria, Jackson, & Takeuchi, 2010; Williams, & Neighbors, 2006). Thus, this study sought to describe both the distribution and contribution of risk and protective factors in relation to depression among a sample of African-, European-, and Latina-American mothers of adolescents, including testing a hypothesized mechanism through which social support, an important protective factor specific to women and depression, operates. ^ Despite the finding that the levels of depression were not statistically different across all three groups of women, surprising results were found in describing the distribution of both risk and protective factors, in that results reported among all women who were mothers when analyzed masked differences within each ethnic group when SES was assessed, a point made explicit by Williams (2002) regarding racial and ethnic variations in women's health. In the final analysis, while perceived social support was found to partially mediate the effect of social isolation on depression, among African-Americans, the direct effect of social isolation and depression was lower among this group of women, as was the indirect effect of social isolation and perceived social support when compared to European- and Latina-American mothers. Or, put differently, higher levels of social isolation were not found to be as associated with more depression or lower social support among African-American mothers when compared to their European- and Latina-American counterparts. ^ Women in American society occupy a number of roles, i.e., that of being female, married or single, mother, homemaker or employee. In addition, to these roles, ethnicity and SES also come into play, such that the intersection of all these roles and the social contexts that they occupy are equally important and must be taken into consideration when making predictions drawn from the social stress model. Based on these findings, it appears that the assumptions of the social stress model need to be revisited to include the variety of roles that intersect among individuals from differing social groups. More specifically, among women who are mothers and occupy a myriad of other roles, i.e., that of being female, married or single, African- or Latina-American, mother, homemaker or employee, the intersection of all the roles and the social contexts that women occupy are equally important and must be taken into consideration when looking at both the types and distribution of stressors across women. Predictions based on simple, mutually exclusive categories of social groups may lead to erroneous assumptions and misleading results.^

Phytol and phytyldiol concentrations at DYFAMED time series station and sediment trap

Particulate samples from the water column were collected monthly from depths of 5-150 m, between May 1996 and March 1997, in the northwestern Mediterranean Sea (Ligurian Sea) as part of the DYFAMED project within the French JGOFS program. These samples were analyzed by gas chromatography-electron impact mass spectrometry for their phytol and 3-methylidene-3,7,11-trimethylhexadecan-1,2-diol (phytyldiol) content. The corresponding Chlorophyll Phytyl side chain Photodegradation Index, molar ratio of phytyldiol to phytol, was calculated and the mean amount of chlorophyll photodegraded within the euphotic zone estimated. Seasonal differences in the chlorophyll photodegradation process appear in the one-year study. The chlorophyll appeared more photodegraded in the surface water (generally more than 40% photodegraded at 5-10 m) than at the deep chlorophyll maximum (DCM) (40-50 m) observed in the summer stratified waters (about 20% photodegraded). This difference was attributed to the healthy state of the phytoplankton community (coincidence with the highest primary production levels) and to the lower intensity of irradiance at the DCM level. On the other hand, the bulk of the detrital chlorophyll (chlorophyll associated with phytodetritus, phaeopigments) undergoes photodegradation before it sinks out of the photic zone. However, in January (winter mixed water) the pigments exported towards the sea floor were less photodegraded. This is thought to result from a shorter period of residence of the pigments in the photic zone due to vertical convection and grazing activity of macrozooplankton (salps), which are producers of rapid sinking fecal pellets.

Procyclical Productivity and Returns-to-Scale in Philippine Manufacturing

The Philippines is regarded as a highly oligopolistic economy, and it is argued that this is a cause of the relative stagnation of the economy to neighbouring East Asian economies. This presumption might be associated with increasing returns to scale and market power, which are consistent with the procyclical total factor productivity that is observed in the Philippines and the United States. However, this study found no strong evidence supporting increasing returns for aggregate manufacturing and three-digit manufacturing industries during 1956-1980 in the Philippines, based on data constructed by Hooley (1985). Further, this study does not support external effect discussed in Caballero and Lyons (1992).

Context-sensitive synaptic plasticity and temporal-to-spatial transformations in hippocampal slices

Hippocampal slices are used to show that, as a temporal input pattern of activity flows through a neuronal layer, a temporal-to-spatial transformation takes place. That is, neurons can respond selectively to the first or second of a pair of input pulses, thus transforming different temporal patterns of activity into the activity of different neurons. This is demonstrated using associative long-term potentiation of polysynaptic CA1 responses as an activity-dependent marker: by depolarizing a postsynaptic CA1 neuron exclusively with the first or second of a pair of pulses from the dentate gyrus, it is possible to “tag” different subpopulations of CA3 neurons. This technique allows sampling of a population of neurons without recording simultaneously from multiple neurons. Furthermore, it reflects a biologically plausible mechanism by which single neurons may develop selective responses to time-varying stimuli and permits the induction of context-sensitive synaptic plasticity. These experimental results support the view that networks of neurons are intrinsically able to process temporal information and that it is not necessary to invoke the existence of internal clocks or delay lines for temporal processing on the time scale of tens to hundreds of milliseconds.

Characterization of Fus3 Localization: Active Fus3 Localizes in Complexes of Varying Size and Specific Activity

The MAP kinase Fus3 regulates many different signal transduction outputs that govern the ability of Saccharomyces cerevisiae haploid cells to mate. Here we characterize Fus3 localization and association with other proteins. By indirect immunofluorescence, Fus3 localizes in punctate spots throughout the cytoplasm and nucleus, with slightly enhanced nuclear localization after pheromone stimulation. This broad distribution is consistent with the critical role Fus3 plays in mating and contrasts that of Kss1, which concentrates in the nucleus and is not required for mating. The majority of Fus3 is soluble and not bound to any one protein; however, a fraction is stably bound to two proteins of ∼60 and ∼70 kDa. Based on fractionation and gradient density centrifugation properties, Fus3 exists in a number of complexes, with its activity critically dependent upon association with other proteins. In the presence of α factor, nearly all of the active Fus3 localizes in complexes of varying size and specific activity, whereas monomeric Fus3 has little activity. Fus3 has highest specific activity within a 350- to 500-kDa complex previously shown to contain Ste5, Ste11, and Ste7. Ste5 is required for Fus3 to exist in this complex. Upon α factor withdrawal, a pool of Fus3 retains activity for more than one cell cycle. Collectively, these results support Ste5’s role as a tether and suggest that association of Fus3 in complexes in the presence of pheromone may prevent inactivation in addition to enhancing activation.