Adolescents and Sexual Risk-Taking: The Interplay of Constraining Relationship Beliefs, Healthy Sex Attitudes, and Romantic Attachment Insecurity

Introduction: Although sexual exploration during adolescence may be perceived as normative, many adolescents who are sexually active are likely to engage in risky sexual behaviors detrimental to their well-being. The present study examined the influence of insecure attachment (anxious and avoidant dimensions), healthy sex attitudes, and constraining relationship beliefs on the following sexual risk indicators: age at first sex, number of sexual partners, condom use, length of time knowing sexual partners, seriousness of relationship, and frequency of sex. Methods: Cross-sectional data from two cohorts recruited one year apart for a five-year project were analyzed. Adolescents were public high school students from a Southern state in the USA (cohort 1: N = 878, 51.1% females, M = 16.50 years old; cohort 2: N = 759, 46.9% females, M = 15.78 years old). Results: Across both cohorts, healthy sex attitudes were related to having sex for the first time at an older age, having less sexual partners in a lifetime, and knowing one’s sexual partner longer. High scores on the avoidant attachment dimension were related to less commitment to the relationship. This dimension also was related to holding lower scores on healthy sex attitudes, which in turn was related to having more sexual partners and knowing one’s sexual partner for a shorter time. Although not replicated, higher endorsement of constraining relationship beliefs was associated with inconsistent condom use and greater sex frequency. Conclusion: Findings suggests that attachment insecurity, healthy sex attitudes, and constraining relationship beliefs work together to influence adolescent sexual risks

Correlation of Real-time Catecholamine Release and Cytosolic Ca 2+ at Single Bovine Chromaffin Cells

Previous investigations of the role of Ca2+ in stimulus-secretion coupling have been undertaken in populations of adrenal chromaffin cells. In the present study, the simultaneous detection of intracellular Ca2+, with the fluorescent probe fura-2, and catecholamine release, using a carbon-fiber microelectrode, are examined at single chromaffin cells in culture. Results from classic depolarizing stimuli, high potassium (30-140 mM) and 1,1-dimethyl-4-phenylpiperazinium (3-50 microM), show a dependence of peak cytosolic Ca2+ concentration and catecholamine release on secretagogue concentration. Catecholamine release induced by transient high K+ stimulation increases logarithmically with K+ concentration. Continuous exposure to veratridine (50 microM) induces oscillations in intracellular Ca2+ and at higher concentrations (100 microM) concomitant fluctuation of cytosolic Ca2+ and catecholamine secretion. Mobilization of both caffeine- and inositol trisphosphate-sensitive intracellular Ca2+ stores is found to elicit secretion with or without extracellular Ca2+. Caffeine-sensitive intracellular Ca2+ stores can be depleted, refilled, and cause exocytosis in medium without Ca2+. Single cell measurement of exocytosis and the increase in cytosolic Ca2+ induced by bradykinin-activated intracellular stores reveal cell to cell variability in exocytotic responses which is masked in populations of cells. Taken together, these results show that exocytosis of catecholamines can be induced by an increase in cytosolic Ca2+ either as a result of transmembrane entry or by release of internal stores

Comparison of cytosolic Ca 2+ and exocytosis responses from single rat and bovine chromaffin cells

The relationship between cytosolic Ca2+ and catecholamine secretion during stimulus-secretion coupling has been examined at individual chromaffin cells isolated from the cow and rat. Vesicular catecholamine exocytosis was determined via amperometric measurements with carbon fiber microelectrodes and fura-2 was used for simultaneous fluorescent monitoring of cytosolic Ca2+ at the same cell.12 Individual secretory vesicles in cells from the two species were found to release similar amounts of catecholamine. In addition, the time courses for secretion from individual vesicles was similar with rat and bovine chromaffin cells. The total quantity of catecholamine released and the change in cytosolic Ca2+ were also similar in response to exposure to K+ (60 mM), DMPP (50 uM), and histamine (50 uM), although both responses were more prolonged following DMPP and histamine at bovine cells. Agents that mobilize intracellular Ca2+-stores such as methacholine, caffeine and bradykinin resulted in different cytosolic Ca2+ and exocytosis responses at the rat and bovine chromaffin cells. Results indicates a heightened Ca2+ store activity or a more filled state in chromaffin cells from the rat. The results of this study clearly show that single cell techniques can be used to characterize stimulus-secretion coupling. The requirement for lower numbers of cells with these techniques means that chromaffin cells from rodents can be routinely employed. This can be advantageous to minimize biological variability21 which occurs with organs obtained from slaughter houses and enables the investigation of genetically-altered animals

Extracellular Ionic Composition Alters Kinetics of Vesicular Release of Catecholamines and Quantal Size During Exocytosis at Adrenal Medullary Cells

The temporal resolution of carbon-fiber microelectrodes has been exploited to examine the plasticity of quantal secretory events at individual adrenal medullary cells. The size of individual quantal events, monitored by amperometric oxidation of released catecholamines, was found to be dependent on the extracellular ionic composition, the secretagogue, and the order of depolarization delivery. Release was observed with either exposure to 60 Mi K* in the presence of Ca2+ or exposure to 3 mM Baz+ in solutions of different pH, with and without external Ca2'. Ba2' was demonstrated to induce Ca2 +- independent exocytotic release for an extended period of time (>4 min) relative to release induced by K* (-30 s), which is Ca2+-dependent. In all cases, simultaneous changes of intracellular divalent cations, monitored by fura-2 fluorescence, accompanied quantal release and had a similar time course. Exocytosis caused by Ba2+ in Ca2+-free medium had a larger mean spike area at pH 8.2 than at pH 7.4. When Ba4+-induced spikes measured at pH 7.4 were compared, the spikes in CaX+-free medium were found to be broader and shorter, but had the same area. Release induced by Ke after exposure to Ba2+ was comprised of larger quantal events when compared to preceding K* stimulations. Finally, spikes obtained with Ba2+ exposure at an extracellular pH of 5.5 had a different shape than those obtained in more basic solutions. These changes in spike size and shape are consistent with the interactions between catecholamines and other intravesicular components

Mapping the field of military nursing research 1990–2013: A bibliometric review

BACKGROUND: Over the past 20 years, military forces worldwide have been engaged in a number of conflicts and humanitarian operations and the impact of this on the field of military nursing research is unknown. The aim of this bibliometric review was to investigate the research field of military nursing in the main databases with the purpose to describe trends in military nursing research since 1990. OBJECTIVES: To identify military nursing papers in the main databases and to describe the field of military nursing research for the period 1990–2013 in terms of research productivity, trends in topic focus, trends in authorship and country of publication. METHOD: Bibliometric review of published military nursing research papers was undertaken in March 2014 and data was extracted and coded and trends were analyzed using SPSSv21. RESULTS: In total 237 articles were included in the review. The majority of publications emanating from America (n = 175, 73.8%) and the quantity of papers has increased significantly since the commencement of the second Gulf War in Iraq from 2003 onwards (n = 156, 65.8%). This has been accompanied by a shift in topic focus from professional (n = 16, 20.3%) and occupational issues (n = 17, 21.5%) pre 2003, to clinical (n = 48, 30.4%) and an increase in multidisciplinary research from 4% in 1990–94 to 29% in 2010–13. The mean citations were 10.6 (sd 17.0) and the mean references per paper post 2003 showed a marked increase from 23.5 to 25.4. CONCLUSION: The military nursing research field appears stronger than it has been in the past twenty years and has demonstrated increased transferability to other fields. To maintain this momentum and further develop the field of military nursing research, military forces worldwide need to devise focused nursing research strategies that involve international and multidisciplinary collaboration.Department of HE and Training approved lis

Walking groups for women with breast cancer: mobilising therapeutic assemblages of walk, talk and place

Walking is widely accepted as a safe and effective method of promoting rehabilitation and a return to physical activity after a cancer diagnosis. Little research has considered the therapeutic qualities of landscape in relation to understanding women’s recovery from breast cancer, and no study has considered the supportive and therapeutic benefits that walking groups might contribute to their wellbeing. Through a study of a volunteer-led walking group intervention for women living with and beyond breast cancer (Best Foot Forward) we address this gap. A mixed-methods design was used including questionnaires with walkers (n=35) and walk leaders (n=13); telephone interviews with walkers (n=4) and walk leaders (n=13); and walking interviews conducted outdoors and on the move with walkers (n=15) and walk leaders (n=4). Questionnaires were analysed descriptively. Interviews were audio-recorded, transcribed verbatim, and analysed thematically. Our study found that the combination of walking and talking enabled conversations to roam freely between topics and individuals, encouraging everyday and cancer-related conversation that created a form of ‘shoulder-to-shoulder support’ that might not occur in sedentary supportive care settings. Walking interviews pointed to three facets of the outdoor landscape – as un/natural, dis/placed and im/mobile – that walkers felt imbued it with therapeutic qualities. ‘Shoulder-to-shoulder support’ was therefore found to be contingent on the therapeutic assemblage of place, walk and talk. Thus, beyond the physical benefits that walking brings, it is the complex assemblage of walking and talking in combination with the fluid navigation between multiple spaces that mobilises a therapeutic assemblage that promotes wellbeing in people living with and beyond breast cancer

The Effects of Protein Kinase C Beta II Peptide Modulation on Superoxide Release in Rat Polymorphonuclear Leukocytes

Phorbol 12-myristate 13-acetate (PMA; a diacylglycerol mimetic) is known to augment polymorphonuclear leukocyte (PMN) superoxide (SO) release via protein kinase C (PKC) activation. However, the role of PKC beta II (βII) mediating this response is not known. It’s known that myristic acid (myr-) conjugation facilitates intracellular delivery of the cargo sequence, and that putative PKCβII activator and inhibitor peptides work by augmenting or attenuating PKCβII translocation to cell membrane substrates (e.g. NOX-2). Therefore, we hypothesize that myr- conjugated PKCβII peptide-activator (N-myr-SVEIWD; myr-PKCβ+) would increase PMA-induced rat PMN SO release, whereas, myr-PKCβII peptide-inhibitor (N-myr-SLNPEWNET; myr-PKCβ-) would attenuate this response compared to non-drug treated controls. Rat PMNs (5x106) were incubated for 15min at 370C in the presence/absence of myr-PKCβ+/- (20 μM) or SO dismutase (SOD;10μg/mL; n=8) as positive control. PMA (100nM) induced PMN SO release was measured spectrophotometrically at 550nm via reduction of ferricytochrome c for 390 sec. PMN SO release increased absorbance to 0.39±0.04 in non-drug treated controls (n=28), and 0.49±0.05 in myr-PKCβ+(n=16). This response was significantly increased from 180 seconds to 240 seconds (p\u3c0.05). By contrast, myr-PKCβ- (0.26±0.03; n=14) significantly attenuated PMA-induced SO release compared to non-drug controls and myr-PKCβ+ (p\u3c0.05). SOD-treated samples showed \u3e90% reduction of PMA-induced SO release and was significantly different from all groups (p\u3c0.01). Cell viability ranged between 94± to 98±2% in all groups as determined by 0.2% trypan blue exclusion. Preliminary results suggest that myr-PKCβ- significantly attenuates PMA-induced SO release, whereas myr-PKCβ+ significantly augments PMA-induced SO release, albeit transiently. Additional dose response and western blot experiments are planned with myr-PKCβ+/- in PMA-induced PMN SO release assays. This research was supported by the Department of Bio-Medical Sciences and the Division of Research at PCOM and by Young Therapeutics, LLC