Faculty of Nursing Works

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The effect of various stresses, corticosteroids and adrenergic agents on phagocytosis in the rainbow trout Oncorhynchus mykiss
(1994) Narnaware, Yuwaraj; Baker, Bridget; Tomlinson, Mike
The effect of acute and chronic stress on the phagocytic activity of putative macrophages from the rainbow trout. Oncorhynchus mykiss has been assessed, using an in vitro phagocytic index, in which the average number of engulfed yeast cells in a population of phagocytes is determined. An injection stress given under light anaesthesia, or a longer noise stress combined with confinement, both significantly reduced, within 3 h, the level of phagocytic activity of macrophages from the spleen and pronephros. Daily injection stress over six days had a lesser effect on the proportion of phagocytically active cells even though plasma cortisol levels were equally raised. Daily dexamethasone injection depressed the proportion of phagocytically active cells more than saline injection. In these in vivo experiments, it was not possible to determine whether stress and steroids depressed the phagocytic activity of individual macrophages or caused the active macrophages to migrate out of the spleen and pronephros. Administration of cortisol (200 nM) to trout macrophages in vitro failed to depress phagocytic activity within a 3h period but both α- and β-adrenergic agonists (10 μM) were usually depressive. It is proposed that the autonomic nervous system may be an early regulator of macrophage phagocytosis following stress and that corticosteroids only exert their suppressive effect on macrophage activity in the longer term.
Influence of environmental color and diurnal phase on MCH gene expression in the trout
(1995) Suzuki, M.; Narnaware, Yuwaraj; Baker, B. I.
Melanin-concentrating hormone (MCH) gene expression in the brain of rainbow trout, reared and maintained in either pale or black-coloured tanks, was studied using in situ hybridization histochemistry. MCH transcripts were most prevalent in the magnocellular neurones of the nucleus lateralis tuberis (NLT), which project to the pituitary gland. They were also present, although at much lower levels, in dorsally projecting parvocellular neurones, sited more posteriorly above the lateral ventricular recess (LVR). In the NLT the most intense hybridization signal was seen over the pituitary stalk; above the LVR, the most active neurones were located caudally. In both the NLT and above the LVR, MCH hybridization signal was 4-fold stronger in white-reared fish than in black-reared fish. There was also a marked diurnal variation in MCH expression in both sites, with high levels at 16.00 h and lower levels at 04.00 h. The results show that gene activity in both hormonal (NLT) and neuromodulator/neurotransmitter (LVR) MCH neurones is induced by pale environmental colour and that MCH gene activity is subject to pronounced diurnal variation.
Evidence that cortisol may protect against the immediate effects of stress on circulating leukocytes in the trout
(1996) Narnaware, Yuwaraj; Baker, B. I.
Rainbow trout stressed by an intraperitonal injection of saline displayed reduced phagocytic activity of their spleen and head-kidney macrophages within 3 hr. Phagocytic activity was similarly depressed by injecting noradrenalin, but was maintained in fish injected with the adrenergic blocking agent phentolamine, suggesting that endogenous catecholamines are involved in this stress response. Since stress may increase the number of circulating granulocytes, it is proposed that noradrenalin, released during stress, causes the liberation of active macrophages from the lymphocytic tissue, the remaining macrophages therefore showing a lowered phagocytic index. Cortisol injection, like phentolamine, prevented the depressive effect of stress on the phagocytic index but did not antagonize the depressive effect of exogenous noradrenalin. It is suggested that the stress-induced release of endogenous catecholamines may be prevented by cortisol. Injection stress caused a decline in the number of circulating lymphocytes/thrombocytes, indicating their retrafficking into some other tissue. This was opposed by cortisol and by high doses of noradrenalin. It is proposed that cortisol or noradrenalin may oppose, directly or indirectly, the expression of adhesion molecules which are normally induced after stress.
Effect of injected growth hormone on phagocytosis in silver sea bream (Sparus sarba) adapted to hyper- and hypo-osmotic salinities
(1997) Narnaware, Yuwaraj; Kelly, Scott; Woo, Norman
Growth hormone (GH) is known to exert a myriad of functions throughout the vertebrates and in fish, its growth-stimulating and osmoregulatory e#ects are most prominent (Sakamoto et al., 1993; Chen et al., 1994). In mammals, GH is generally considered to be the principal hormone which exerts immunoregulatory properties and there is recent evidence for a similar e#ect of GH in fish (Sakai et al., 1996a,b,c). GH influences the immune processes from antibody formation to the appearance of di#erentiation markers on lymphocytes and augments the cytolytic activity of T cells, their proliferation and delayed type hyper-sensitivity (Blalock, 1989, 1994). These also include the enhancement of natural killer cell activity, mitogenic responses of lymphocytes and antibody production (Kelley, 1989).
Stimulation of macrophage phagocytosis and lymphocyte count by exogenous prolactin administration in silver sea bream (Sparus sarba) adapted to hyper- and hypo-osmotic salinities
(1998) Narnaware, Yuwaraj; Kelly, Scott; Woo, Norman
Juvenile silver sea bream (Sparus sarba) were adapted to hyper- (33 ppt) and hypo-osmotic (6 ppt) salinities for 3 weeks and injected daily with ovine prolactin (1 μg/g body weight i.p.) during the last 7 days of the adaptation period. Fish injected with prolactin exhibited significant increases in percent phagocytosis and phagocytic index of both pronephric and splenic macrophages regardless of salinity. Prolactin injection also resulted in elevated blood lymphocyte counts in both hyper- and hypo-osmotically adapted sea bream. The present results provide further evidence for the existence of a neuroendocrine–immune link in teleosts.
Health-related hardiness and the effect of a psycho-educational group on clients' symptoms
(1999) Austin, W.; Pollard, Cheryl
In the health literature, an individual's ability to resist illness when under stress has been referred to as ‘hardiness’. Resources, which may be used to sustain a sense of well being, can be categorized by two broad domains, ‘control’ and ‘commitment and challenge'. In this research, a quasi-experimental nonequivalent control group design was used to determine the impact of a specific clinical nursing intervention (the Wellness Program) in terms of its usefulness in fostering the development of health-related hardiness. Findings demonstrated a significant reduction in symptoms related to obsessive compulsiveness, hostility, psychoticism and average level of distress after subjects completed a relatively short psycho-educational health promotion group. Subjectively, the treatment group subjects also described positive changes in thoughts, feelings and behaviours. This research has implications for clinical interventions using small groups to promote health.
Processes underlying children's responses to witnessing physical aggression in their families
(1999) Onyskiw, Judee
This study used structural equation modeling to test the hypotheses that intra-family aggression affects children: (1) because of observational learning/modeling of aggressive behaviour, and (2) because intra-family aggression disrupts mother's ability to provide warm, responsive parenting. This study examined whether there were effects due to the child's age or gender, and if there were differences depending on whether the information was provided from the mother or the child.
Effect of salinity and ration size on macrophage phagocytosis in juvenile black sea bream (Mylio macrocephalus)
(2000) Narnaware, Yuwaraj; Kelly, Scott; Woo, Ying Shiu Norman
The effects of salinity adaptation and ration size on macrophage phagocytosis were assessed in black sea bream (Mylio macrocephalus) juveniles. Salinity had no effect on phagocytosis in fish that were fed a 10% ration size. Reducing ration size from 10 to 5% resulted in a significant reduction in splenic and pronephric macrophage phagocytosis of fish adapted to hyper-(33 p.p.t.) and hypo-osmotic (6 p.p.t.) salinities. The fish that were adapted to an iso-osmotic salinity (12 p.p.t.) and fed a 5% ration size were able to maintain macrophage phagocytic activity at levels comparable to those of fish that were fed a 10% ration size. It is proposed that the adaptation of sea bream to an iso-osmotic medium is beneficial in that it stimulates the immune response through activation of macrophage phagocytosis.
Brain regulation of feeding behavior and food intake in fish
(2000) Lin, Xinwei; Volkoff, Hélène; Narnaware, Yuwaraj; Bernier, Nicholas J.; Peyon, Pierre P.; Peter, Richard E.
In mammals, the orexigenic and anorexigenic neuronal systems are morphologically and functionally connected, forming an interconnected network in the hypothalamus to govern food intake and body weight. However, there are relatively few studies on the brain control of feeding behavior in fish. Recent studies using mammalian neuropeptides or fish homologs of mammalian neuropeptides indicate that brain orexigenic signal molecules include neuropeptide Y, orexins, galanin and β-endorphin, whereas brain anorexigenic signal molecules include cholecystokinin, bombesin, corticotropin-releasing factor, cocaine- and amphetamine-regulated transcript, and serotonin. Tachykinins may also have an anorectic action in fish. The brain hypothalamic area is associated with regulation of food intake, while sites outside the hypothalamus are also involved in this function. There is correlation between short-term changes in serum growth hormone levels and feeding behavior, although possible mechanisms integrating these functions remain to be defined.
Regulation of food intake by neuropeptide Y in goldfish
(2000) Narnaware, Yuwaraj; Peyon, Pierre P.; Lin, Xinwei; Peter, Richard E.
In mammals, neuropeptide Y (NPY) is a potent orexigenic factor. In the present study, third brain ventricle (intracerebroventricular) injection of goldfish NPY (gNPY) caused a dose-dependent increase in food intake in goldfish, and intracerebroventricular administration of NPY Y1-receptor antagonist BIBP-3226 decreased food intake; the actions of gNPY were blocked by simultaneous injection of BIBP-3226. Goldfish maintained on a daily scheduled feeding regimen display an increase in NPY mRNA levels in the telencephalon-preoptic area and hypothalamus shortly before feeding; however, a decrease occured in optic tectum-thalamus. In both fed and unfed fish, brain NPY mRNA levels decreased after scheduled feeding. Restriction in daily food ration intake for 1 wk or food deprivation for 72 h resulted in increased brain NPY mRNA levels. Results from these studies demonstrate that NPY is a physiological brain signal involved in feeding behavior in goldfish, mediating its effects, at least in part, through Y1-like receptors in the brain.
Neuropeptide Y stimulates food consumption through multiple receptors in goldfish
(2001) Narnaware, Yuwaraj; Peter, Richard E.
In this study, the acute effects of brain intracerebroventricular (icv) injections of mammalian neuropeptide Y (NPY) Y1 ([31Leu,34Pro]NPY), Y2 (NPY2–36) and Y5 ([d-32Trp]NPY) receptor subtype agonists on food intake in goldfish were examined. Icv injection of Y1 and Y5 receptor agonists in dosages of 1 and 5 ng/g exhibited dose-dependent effects on food intake; however, higher dosages of both receptor subtypes had desensitising effects on food intake, and caused a decrease in food intake in comparison to the lower dosages. At 10 and 20 ng/g, Y1 receptor agonist-treated fish exhibited feeding significantly lower than intact and saline-injected fish; fish treated with the same dosages of Y5 agonist exhibited food intake similar to intact and saline-injected fish. Y2 agonist had no effects on food intake. Co-icv administration of Y1 and Y5 agonists in dosages of 1 and 5 ng/g caused enhanced food intake that was additive of the individual doses alone. However, desensitising one receptor did not influence the responsiveness of the other. Co-icv injection of Y1 receptor agonist in desensitizing high dosages (10 and 15 ng/g) with Y5 receptor agonist in lower doses (1 and 5 ng/g, respectively) or vice versa, resulted in a food intake similar to the dosages of Y1 and Y5 receptor agonists at 1 and 5 ng/g given alone. Overall, this study demonstrates that NPY acts centrally through Y1 and Y5 receptors to stimulate food intake in goldfish. The Y1 and Y5 receptors appear to act independently in the stimulation of food intake in goldfish.
Effects of food deprivation and refeeding on neuropeptide Y (NPY) mRNA levels in goldfish
(2001) Narnaware, Yuwaraj; Peter, Richard E.
In mammals, NPY is a key factor in the regulation of feeding behavior. In the present study, the effects of refeeding for 1–3 h in 72–75-h food deprived (FD) goldfish on the levels of NPY mRNA in telencephalon-preoptic (TEL-POA), hypothalamus (HYP) and optic tectum-thalamus (OT-THAL) were examined, using Northern blot analysis. Goldfish FD for 72 h exhibited a significant increase in NPY mRNA levels in all brain regions. At 1 h after 72-h FD (73-h FD), NPY mRNA was significantly increased in TEL-POA and OT-THAL, but remained the same as 72-h FD fish in HYP. At 3 h after 72-h FD (75 h), all brain regions exhibited a significant increase in NPY mRNA levels. However, subsequent refeeding for 1–3 h rapidly and completely reversed the effects of FD in all brain regions, reaching fed levels within 1–3 h of refeeding. Serum GH levels were highest in 72-h FD fish, but decreased significantly over 1–3 h after 72-h FD; whereas, refeeding reversed the increase in serum GH levels only at 3 h after refeeding. Taken together, these results further support that NPY is a physiological brain transducer involved in the regulation of daily appetite and feeding in goldfish.
Influence of diet composition on food intake and neuropeptide Y (NPY) gene expression in goldfish brain
(2002) Narnaware, Yuwaraj; Peter, Richard E.
In this study, goldfish demonstrate preference for high carbohydrate and high fat diets, with no preference shown for high protein diets. Fish fed high (45% and 55%) carbohydrate (CHO) diets for 1 and 4 weeks exhibited decreased NPY gene expression in telencephalon–preoptic area (TEL–POA) and optic tectum–thalamus (OT–THAL) compared to fish fed low CHO (35% and 40%) diets. In hypothalamus (HYP), NPY gene expression was significantly increased after 1 week in fish fed both low and high CHO diets compared to control diet (40% CHO); after 4 weeks, the pattern in HYP was reversed. Fish fed a high fat (9%) diet had low NPY gene expression in TEL–POA after 1 and 4 weeks; however, HYP NPY expression was increased in fish fed a low (3%) fat diet after 1 week, and 2% and 3% fat diets after 4 weeks. In OT–THAL, NPY gene expression was decreased in fish fed a 2% fat diet for 1 week, and increased after 4 weeks. Feeding diets with different protein contents for 1 or 4 weeks did not influence NPY gene expression in goldfish brain. The results demonstrate, for the first time in a lower vertebrate, that NPY gene expression in goldfish brain is influenced by macronutrient intake.
Health and use of health services of children exposed to violence in their families
(2002) Onyskiw, Judee
Objective: to obtain baseline data on the health status and use of health services of children exposed to violence in their families. These baseline findings suggest that exposure to domestic violence has an adverse impact on children’s health and use of health services. As future cycles become available, these children will be followed to determine the long-term impact on these outcomes.
The role of the forensic nurse in the assessment of abuse among female suicide survivors
(2002) Symonds-Brown, Holly; Constantino, R. E.; Crane, P.; Sutton, L.
Examined experiences of abuse in 49 female suicide survivors (aged 24-59 yrs). The Ss completed a socio-demographic questionnaire and the Victim Rejection Scale. The results showed that 65.3% of the survivors of suicide had experienced some form of abuse, the most frequent being verbal abuse. It is concluded that experiences of abuse may effect the bereavement process and coping strategies in surviving the suicide of a spouse. Implications for forensic nursing are discussed.
Measuring knowledge utilization in health care
(2003) Estabrooks, Carole; Wallin, Lars; Milner, Margaret
In this paper we address the need for methodological advances in the research utilization field focusing on the area of measurement. Unresolved measurement challenges present an important and practical problem. An inability to adequately measure research utilization calls into question studies that claim to demonstrate either its causes or its effects. In this paper we: briefly review the concept of research utilization and its meanings, review the requirements of good measurement instruments, review existing research utilization instruments in nursing, and discuss implications and future requirements for scholarship in this field.
The role of intermediaries: getting evidence into practice
(2004) Ferguson, Linda; Milner, Margaret; Snelgrove Clarke, Erna
Ehrenberg and Estabrooks' assertion that using research does matter began this series of articles on research utilization (RU) in practice. RU with due consideration of patient preferences, clinical judgment, and available resources can contribute to positive patient outcomes. For many reasons, however, the use of research in nursing practice is limited. We now know that passive diffusion of research has had a limited effect on the use of research to improve patient outcomes. We need better understanding of factors in the practice setting that support research use. Nurses have consistently reported lack of time, lack of access to research, and lack of skill in critiquing research as their main barriers to greater RU. The identification of RU as a social process, coupled with research that demonstrates nurses prefer social mediums over other knowledge sources, suggests that intermediaries may be a necessary link to greater research use. The authors discuss the role of intermediaries and their ability to influence the use of research in clinical practice. They highlight some important points to consider from the literature and suggest strategies that enhance RU within the context of the intermediary role.
The prevalence of pressure ulcers in a tertiary care pediatric and adult hospital
(2004) Groeneveld, Audrey; Anderson, Marjorie; Allen, Sandy; Bressmer, Sandy; Golberg, Maria; Magee, Bernice; Milner, Margaret; Young, Sue
According to the Agency for Healthcare Research and Quality (AHRQ, formerly the AHCRP), the occurrence of pressure ulcers in acute care facilities continues to be a significant healthcare problem. The frail elderly, the very young, and patients undergoing lengthy operative procedures are especially at risk. Pressure ulcers are costly in terms of patient morbidity and mortality, quality of life, and consumption of healthcare resources. For nurses working in acute care settings, the prevention and treatment of pressure ulcers in their patients remains an important nursing care concern, which will increase as the population of frail elderly in acute care increases.
Clinical nurse educators as agents for change: increasing research utilization
(2005) Milner, Margaret; Estabrooks, Carole; Humphrey, C.
The purpose of this study was to examine the determinants of research utilization among clinical nurse educators. The primary goal for clinical nurse educators is the facilitation of professional development of practicing nurses. Responsibilities include promoting best practice by mentoring others, acting as an information source, and assisting in the development of policies and procedures based on available research evidence. Using Rogers’ (Diffusion of Innovations, 4th edn., The Free Press, New York) diffusion of innovations theory as a theoretical foundation, we conducted a secondary analysis to test a predictive model of research utilization using linear regression. Results show that educators report significantly higher research use than staff nurses and managers. Predictors of research utilization include attitude toward research, awareness of information based on research, and involvement in research activities. Localite communication predicted conceptual research use and mass media predicted symbolic use, lending support to the idea that overall, instrumental, conceptual, and symbolic research utilization are conceptually different from one another. Our findings show that the research utilization behaviors of clinical nurse educators position them to facilitate evidence-based nursing practice in organizations. We discuss the theoretical, conceptual, and nursing role implications of our findings for nursing practice, education, and research. Suggestions for future research includes studying actual use of research findings of clinical nurse educators and designing intervention studies that assesses the effectiveness of clinical nurse educators as facilitators of research utilization in organizations.
Sources of practice knowledge among nurses
(2005) Estabrooks, Carole; Rutakumwa, William; O’Leary, Katherine; Profetto McGrath, Joanne; Milner, Margaret; Levers, Merry Jo; Scott Findlay, Shannon
Several studies have been published listing sources of practice knowledge used by nurses. However, the authors located no studies that asked clinicians to describe comprehensively and categorize the kinds of knowledge needed to practice or in which the researchers attempted to understand how clinicians privilege various knowledge sources. In this article, the authors report findings from two large ethnographic case studies in which sources of practice knowledge was a subsidiary theme. They draw on data from individual and card sort interviews, as well as participant observations, to identify nurses’ sources of practice knowledge. Their findings demonstrate that nurses categorize their sources of practice knowledge into four broad groupings: social interactions, experiential knowledge, documents, and a priori knowledge. The insights gained add new understanding about sources of knowledge used by nurses and challenge the disproportionate weight that proponents of the evidence-based movement ascribe to research knowledge.

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