bluuebunny/crossref_metadata_2025 huggingface dataset:
Estrogen and Stress Interact to Regulate the Hypothalamic Expression of a Human Proenkephalin Promoter‐β‐Galactosidase Fusion Gene in a Site‐Specific and Sex‐Specific Manner
Authors: Priest Catherine A. , Borsook David , Pfaff Donald W.
Published: November 2003

Gonadal steroids and physiological stressors affect the regulation of proenkephalin (PPE) gene expression in the paraventricular (PVN) and ventromedial (VMH) hypothalamic nuclei. To examine the effects of these modulators at the cellular level, the current study utilized a transgenic mouse line that expresses a human proenkephalin promoter/bacterial β‐galactosidase fusion gene (ENK‐1). Previous studies have demonstrated that the regulatory sequences included in this transgene are sufficient to support appropriate transcriptional regulation of the reporter gene in the PVN of male ENK‐1 mice in response to stress. The present experimental paradigm was designed to examine possible interactions of sex and circulating estrogen levels with the opioid responses to acute systemic stressors, an intraperitoneal injection of hypertonic (1.5 M) or isotonic (0.15 M) saline. Adult ENK‐1 mice were gonadally intact, gonadectomized, or 21 days postpartum. Forty‐eight hours before perfusion, castrated males and ovariectomized females received either 10 μg estradiol benzoate or oil vehicle and 4 animals per group received no further treatment. Six h before perfusion, remaining animals received a single intraperitoneal injection of either hypertonic or isotonic saline. Tissues were sectioned through the hypothalamus and processed for X‐gal histochemistry. In the VMH of ovariectomized females that received isotonic saline, estrogen significantly elevated transgene expression. This effect was not seen in females that only received estrogen or in those that received the severe systemic stressor of an injection of hypertonic saline. Estrogen and stress did not interact to elevate transgene expression in the VMH of males. A different pattern of expression was observed in the PVN; injection of hypertonic saline induced transgene expression only in gonadally intact males and in castrated males given estrogen. These findings demonstrate that stress and estrogen have sex‐specific and site‐specific regulatory effects on the expression of a PPE promoter transgene in hypothalamic neurons.
Gender‐Specific Induction of Pituitary RNA by Estrogen and its Modification by Thyroid Hormone
Authors: Zhu Yuan‐Shan , Dellovade Tammy , Pfaff Donald W.
Published: November 2003

Estrogen and thyroid hormones play important roles in the regulation of pituitary function. We presently show that pituitary weight and total cellular RNA levels were significantly decreased by ovariectomy in female rats and were significantly increased by castration in males, without alterations in pituitary DNA levels as compared to intact animals. Treatment with a single dose of estrogen produced a significant increase in pituitary RNA in ovariectomized females but not castrated males. This effect was more obvious following multiple doses of estrogen, and was blocked by pretreatment with cycloheximide, or surprisingly by concomitant administration of triiodothyronine (T3). Analysis of estrogen response element (ERE) binding activity in pituitary nuclear protein extracts revealed that estrogen produced a rapid induction of a slow mobility complex of ERE binding in ovariectomized females much greater than in castrated males. Thus, estrogen‐induced increases in pituitary total RNA levels are dependent on new protein synthesis, are gender‐specific, are inhibited by T3, and may be mediated via specific estrogen‐induced changes in protein‐DNA interactions.
D1 Dopamine Receptor Agonist (SKF‐38393) Induction of FosImmunoreactivity in Progestin Receptor‐Containing Areasof Female Rat Brain
Authors: Meredith J. M. , Auger A. P. , Blaustein J. D.
Published: November 2003

Injection of dopamine or dopamine receptor subtype agonists facilitates the expression of lordosis in estrogen‐primed female rats. The D1 receptor specific agonist, SKF‐38393, facilitates lordosis in estradiol‐primed female rats via a process that requires progestin receptors. Based on these data, neuronal response to the D1 receptor agonist SKF‐38393 was assessed by expression of the immediate early gene protein, Fos. In the first experiment we examined the modulation of Fos expression by D1 agonists in progestin receptor‐containing areas of estradiol‐primed female rat brain. In the second experiment we examined if there are progestin receptor‐containing cells that respond to stimulation of D1 receptors with increased Fos expression. Ten to 14 days following ovariectomy and stereotaxic surgery, animals were injected with 5 μg estradiol benzoate. Forty eight h later they were injected intracerebroventricularly with 100 ng of SKF‐38393 or saline. One h following injection animals were perfused, and brain sections immunostained for Fos protein. Results from the first experiment suggest that SKF‐38393 increased the total number of Fos immunoreactive cells in the mid‐ventromedial hypothalamic nucleus/ventrolateral portion (VMHVL), the caudal VMHVL, the paraventricular hypothalamic nucleus and the caudate putamen. In the medial preoptic area, the rostral VMHVL and the arcuate hypothalamic nucleus, there was a significant increase in the number of darkly stained Fos‐immunoreactive cells following the SKF‐38393 treatment. In the second study, SKF‐38393 increased the number of progestin receptor‐containing cells which contained Fos immunoreactivity in the caudal VMHVL. The results suggest potential sites of action for the facilitation of sexual behavior by centrally administered D1 agonists.
Osmotic Modulation in Glutamatergic Excitatory Synaptic Inputs to Neurons in the Supraoptic Nucleus of Rat Hypothalamus in vitro
Authors: Inenaga Kiyotoshi , Cui Lu‐Ning , Nagatomo Toshihisa , Honda Eiko , Ueta Yoichi , Yamashita Hiroshi
Published: November 2003

To clarify influence of osmotic stimulation on the excitatory synaptic inputs to the neurosecretory cells of the supraoptic nucleus (SON), the blind patch technique was used in rat hypothalamic slice preparations. Stable whole‐cell recordings were made from 22 neurons in the SON. To observe spontaneous excitatory postsynaptic currents (sEPSCs) in the SON neurons, membrane potentials were clamped between −50 and −90 mV. The effects of hypertonic stimulation on the frequency of the sEPSCs were tested in 18 SON neurons. Bath application of mannitol 30 or 60 mM increased the frequency of the sEPSCs. During the application of mannitol (60 mM), the frequency of the sEPSCs increased in 12 of 15 neurons without a change in amplitude. Hypertonic stimulation with NaCl (30 mM) had similar effects to that of mannitol. The increased frequency of miniature EPSCs (mEPSCs) during mannitol application persisted in the presence of TTX in all 8 SON neurons tested with no change in amplitude. Both the non‐NMDA antagonist CNQX at 10–30 μM (n=6) and the non‐selective glutamate antagonist kynurenic acid at 1 mM (n=3) almost completely blocked the EPSCs while the NMDA antagonist AP‐5 at 10 μM had no effect on the frequency of the EPSCs in the 4 neurons tested. During application of CNQX, mannitol (60 mM) was added to the perfusion medium in 3 SON neurons. Under these conditions, mannitol had no effect on the frequency of EPSCs. We conclude that hypertonic stimulation directly influences glutamatergic inputs to the neurosecretory cells of the SON by an action on the presynaptic terminals and enhances the excitatory synaptic events.
Peptidergic Modulation of Serotonin Release from Cultured Rat Pinealocytes
Authors: Simonneaux Valérie , Miguez Jesus M. , Pevet Paul
Published: November 2003

This paper describes the effects of β‐adrenergic and peptidergic inputs on serotonin (5‐HT) synthesis, outflow and metabolism into melatonin in cultured dissociated rat pinealocytes. The spontaneous outflow of 5‐HT from pinealocytes was high as demonstrated by the elevated levels of extracellular 5‐HT accumulated in the medium (about 5 ng/h/70,000 pineal cells). The β‐adrenergic agonist isoproterenol (ISO) used at concentrations up to 10−6 M induced a moderate (+20–40%) increase in intra‐ and extracellular 5‐HT levels together with a large release of melatonin. At a higher ISO stimulation (10−5 M), the intra‐ and extracellular levels of 5‐HT were significantly (−25–30%) reduced whereas melatonin secretion was dramatically increased. This is interpreted as a large 5‐HT mobilization for melatonin synthesis and release, consequently reducing both the intracellular pool and outflow of 5‐HT. The peptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) up to 10−7 M induced always a moderate (+20–30%) increase in intra‐ and extracellular levels of 5‐HT. However, the use of nM concentrations of VIP or PACAP together with 10−6 M ISO induced a decrease in 5‐HT outflow (−25–30%) and a dramatic increase in melatonin secretion as did 10−5 M ISO alone. Neuropeptide Y (NPY) is another pineal peptide which induced a stimulation of 5‐HT outflow (+30–40%) although its effect on melatonin release was marginal. The above results are discussed in term of the multineuronal regulation of the synthetic and secretory activities of the rat pineal gland.
Inhibitory Effect of 5‐Hydroxytryptamine Receptor Activation on Caudal Neurosecretory Cells of the Flounder, Platichthys flesus
Authors: Hubbard P. C. , Balment R. J. , McCrohan C. R.
Published: November 2003

Immunocytochemical evidence suggests that the neuroendocrine Dahlgren cells of the teleost caudal neurosecretory system (CNSS) are innervated by descending serotonergic fibres. However, the modulatory effect(s) of 5‐hydroxytryptamine (5‐HT) on the activity of the CNSS are not known. The present study investigates the effect of superfusion of 5‐HT and the selective 5‐HT1 receptor agonist 5‐carboxamidotryptamine (5‐CT) on the electrophysiological properties of Dahlgren cells recorded intracellularly in an isolated CNSS preparation from the flounder. Superfusion of 5‐HT (10−7−10−3M) caused a concentration‐dependent, reversible hyperpolarization of the resting membrane potential (Em) of cells previously identified as ‘Type 1’ (putative urotensin I‐secreting) cells (control =−63.5±1.5 mV; 10−4M 5‐HT=−95.0±0.9 mV, n=6, P<0.01). The EC50 was 7.6±4.1 μM (n=6). Hyperpolarization resulted in a reduction or cessation of firing of these cells, suggesting an inhibitory role for the serotonergic input to the CNSS. Hyperpolarization was accompanied by a concomitant decrease in the membrane input resistance (control =16.6±2.8 MΩ; 10−4M 5‐HT=6.4±1.3 MΩ; n=6, P<0.05) and time constant (control =60.3±13.1 ms; 10−4M 5‐HT=16.0±4.4 ms, n=6, P<0.05). These effects were mimicked by the superfusion of much lower concentrations of 5‐CT (EC50=47.1±7.1 nM, n=4) suggesting that they are possibly mediated by a 5‐HT1 receptor subtype, if the teleost 5‐HT1 receptor has a markedly higher affinity for 5‐CT than 5‐HT, in common with mammalian 5‐HT1 receptors. In contrast to the findings in Type 1 cells, cells identified as ‘Type 2’ (putative urotensin II‐secreting) did not respond to either 5‐HT or 5‐CT, suggesting that the serotonergic input into the CNSS plays no role in the modulation of activity of this sub‐population of neuroendocrine cells. Accordingly, these data suggest a functional difference between Type 1 and Type 2 Dahlgren cells, previously differentiated only on electrophysiological criteria and spatial distribution within the CNSS.
Dopamine‐β‐Hydroxylase Activity is Necessary for Hypothalamo‐Pituitary‐Adrenal (HPA) Responses to Ether, and Stress‐Induced Facilitation of Subsequent HPA Responses to Acute Ether Emerges as HPA Responses are Inhibited by Increasing Corticosterone (B)
Authors: Murakami Kazuharu , Akana Susan F. , Dallman Mary F.
Published: November 2003

To determine a role of norepinephrine (NE) in stress‐induced HPA function, young male rats were treated with diethyldithiocarbamide (DDC) which inhibits dopamine‐β‐hydroxylase, the enzyme that synthesizes NE from dopamine (DA). DDC injected 5 h prior to ether stress stimulated ACTH and corticosterone (B) during this time, and there was no further HPA response to ether. To control for elevated B feedback in DDC effects on HPA responses to ether, rats were adrenalectomized (Adx) and replaced with no (0% B), moderate (40% B) and high (80% B) levels of steroid 5 d prior to DDC or saline with ether stress 5 h later; Sham‐Adx rats were included. In Adx rats increasing B inhibited thymus weight, median eminence CRF content, pituitary and plasma ACTH. In saline‐treated rats, ether 5 h later caused increased CRF content and plasma ACTH in Sham‐Adx and Adx, 0%B, increased ACTH in Adx, 40%B, and no response in Adx, 80% B. B treatment did not alter catecholamine content, and DDC treatment reduced NE content in the paraventricular nuclei by 50–60% in all groups. 5 h after DDC, pituitary ACTH was decreased in all rats with B and plasma ACTH was increased in sham‐Adx and Adx, 40%B; thus DDC caused significant, prolonged stress which should facilitate subsequent HPA responses to acute stress. There was no HPA response to ether in Sham‐Adx, Adx, 0% or 40% B groups, but there was a marked ACTH response to ether in the Adx, 80%B group treated with DDC. We conclude that: 1) the HPA response to ether stress is probably mediated by catecholamines; 2) DDC does not stimulate responses in the HPA axis in the absence of B; and, 3) facilitation of HPA responses to acute stress depends on increased steady‐state B signals. Facilitated responses are probably not mediated by catecholamines. The consequence of facilitation is that under conditions of chronic stress and elevated B concentrations, as in depression or anorexia nervosa in man, or adjuvent‐induced arthritis in rats, the HPA axis is continually responsive to new stimuli.
Transient Suppression of Resting Corticosterone Levels Induces Sustained Increase of AVP Stores in Hypothalamic CRH‐Neurons of Rats
Authors: Schmidt E. D. , Janszen A. W. J W. , Binnekade R. , Tilders F. J. H.
Published: November 2003

Previous studies showed that various stressors can induce delayed (days) and long‐lasting (weeks) increases of vasopressin (AVP) stores in terminals of CRH neurons in the external zone of the median eminence (ZEME) in adult rats. Here we tested whether this long‐lasting neuroplastic change can be induced by mechanisms other than stressor provoked transsynaptic activation of CRH neurons.
Corticosteroid Effects on Gene Expression of Myelin Basic Protein in Oligodendrocytes and of Glial Fibrillary Acidic Protein in Type 1 Astrocytes
Authors: Melcangi R.C. , Magnaghi V. , Cavarretta I. , Riva M.A. , Martini L.
Published: November 2003

The paper describes the effects of corticosterone and deoxycorticosterone (DOC), used in their native or in their 5&agr;‐reduced molecular forms (dihydrocorticosterone, DHC; dihydrodeoxycorticosterone, DHDOC; and tetrahydrodeoxycorticosterone, THDOC) on the gene expression of the myelin basic protein (MBP) and of the glial fibrillary acidic protein (GFAP) in pure cultures, respectively, of oligodendrocytes and type 1 astrocytes obtained from the neonatal rat brain. Among the different steroids tested (corticosterone, DHC, DOC, DHDOC and THDOC), only DHDOC was effective on the gene expression of MBP in the oligodendrocyte cultures; the mRNA levels of this typical oligodendrocyte marker were decreased following exposure to this steroid for 24 h. In the case of the astrocytic marker GFAP, its gene expression was increased by the exposure to corticosterone for 6 and 24 h, while DHC was ineffective; the mineralocorticoid DOC was also ineffective, while its 5&agr;‐reduced derivative, DHDOC, strongly inhibited GFAP gene expression, starting at 6 h after beginning of the treatment.
Peptidases that Degrade Gonadotropin‐Releasing Hormone: Influence on LH Secretion in the Ewe
Authors: Lew Rebecca A. , Cowley Michael , Clarke Iain J. , Smith A. Ian
Published: November 2003

Several peptidases have been postulated to degrade the hypothalamic peptide gonadotropin‐releasing hormone (GnRH), but it is not known if such enzymes contribute significantly to the delivery of GnRH to the pituitary in vivo. Furthermore, the activity of GnRH‐inactivating peptidases may vary in different reproductive states, such as across the estrous cycle. In the present study, specific fluorescent substrates were used to measure the activity of the two major GnRH‐degrading enzymes, prolyl endopeptidase (PEP) and endopeptidase 3.4.24.15 (EP 24.15), in soluble extracts of the median eminentes (ME) of ewes during different phases of the estrous cycle. Levels of EP 24.15 and PEP activity in the ME did not vary significantly across the cycle, although PEP activity was lowest at the time of the preovulatory luteinizing hormone (LH) surge. However, a statistically significant decline in PEP activity (18%, P=0.02) was observed in the ME of OVX ewes in which a surge was induced by estrogen when compared to oil‐treated OVX controls, suggesting a possible negative regulation of PEP activity by this steroid.
Intraventricular Infusion of Arginine Vasotocin induces Singing in a Female Songbird
Authors: Maney Donna L. , Goode Christopher T. , Wingfield John C.
Published: November 2003

Arginine vasotocin (AVT) has been implicated in the activation of courtship and aggressive behaviors in many vertebrate taxa. Here, we tested its effect on singing and other vocal behavior in a songbird. Female white‐crowned sparrows (Z. l. gambelii) were implanted with chronic cannulae aimed at the third ventricle. Infusions of AVT dramatically increased the number of songs and other vocalizations during a 40 min period following infusion. Half of the subjects sang full song following AVT treatment. No bird sang after treatment with saline; any type of vocalization after saline treatment was rare. Female white‐crowned sparrows are known to sing in both spring and winter in the wild; this behavior is thought to be aggressive, functioning in dominance interactions and territoriality. Central infusion of AVT induced singing and other vocalizations in estrogen‐primed, photostimulated subjects as well as in non‐reproductive subjects housed on short photoperiods. Thus, the effects of AVT on vocal behavior may not require breeding levels of gonadal steroids and are probably not seasonal. We hypothesize that both in the breeding and non‐breeding seasons, AVT increases motivation to sing.
Changes in Oxytocin Receptor mRNA in Rat Brain During Pregnancy and the Effects of Estrogen and Interleukin‐6
Authors: Young Larry J. , Muns Scott , Wang Zuoxin , Insel Thomas R.
Published: November 2003

Changes in brain oxytocin receptor (OTR) binding sites during the course of pregnancy may influence the sudden onset of maternal behavior in female rats at parturition. In situ hybridization was used to identify changes in OTR messenger ribonucleic acid (mRNA) expression during pregnancy and parturition. Two patterns of mRNA regulation were observed. Relative to diestrus virgin control females, OTR mRNA was elevated in the lateral septum and medial preoptic area at days 13–15 of pregnancy but not on the morning of parturition. In the central nucleus of the amygdala and ventromedial nucleus of the hypothalamus (VMH), OTR mRNA was most abundant on the morning of parturition. Strong signals for OTR mRNA were detected in the bed nucleus of the stria terminalis, hypothalamic paraventricular nucleus, supraoptic nucleus and suprachiasmatic nucleus. However no group differences were detected in these areas. As estrogen and interleukin‐6 have been suggested to modulate OTR gene expression and both are elevated at the time of parturition, their effects on OTR mRNA in the brain were examined. Estrogen and interleukin‐6, given simultaneously, significantly elevated the concentration of OTR mRNA in the VMH, but not in the amygdala. The increase in the VMH was significantly greater than that produced by estrogen alone, and interleukin‐6 alone had no effects. These results demonstrate that transcriptional regulation of OTR gene expression mediates changes in receptor density in the brain in a region specific manner during pregnancy and suggests a potential mechanism for some of these changes.
Pituitary Adenylate Cyclase‐Activating Polypeptide (PACAP) Actions on αT3‐1 Gonadotrophs Show Desensitization
Authors: McArdle Craig A. , Forrest‐Owen Wyn
Published: November 2003

PACAP is a hypothalamic hypophysiotropic factor that acts upon a number of pituitary cells, including gonadotrophs. In the gonadotroph‐derived αT3‐1 cell line, PACAP acts via PVR1 receptors to stimulate adenylyl cyclase and phosphoinositidase C. PACAP‐stimulated cAMP accumulation is inhibited by protein kinase C‐activating phorbol esters in these cells and the current work was undertaken primarily to establish whether it is also subject to homologous regulation. In acute experiments, PACAP27‐stimulated cAMP accumulation (intracellular plus extracellular) was measured (in the presence of phosphodiesterase inhibitor) both in intact cells and in cell membranes. The peptide increased cAMP accumulation, but initial rates of PACAP27‐stimulated cAMP accumulation were reduced to between 10 and 50% within 10 min of stimulation in both cells and membranes. The initial rate of forskolin‐stimulated cAMP accumulation was maintained in membranes but not in intact cells (although the deviation from linearity was less pronounced than with PACAP27). Thus, rapid homologous desensitization to PACAP27 occurs in intact αT3‐1 cells, but is not entirely receptor specific. Rapid homologous desensitization of PACAP27‐stimulated cAMP accumulation also occurred in the presence of a protein kinase C activating phorbol ester, which inhibited cAMP accumulation without altering the kinetics of the PACAP27 effect. Brief pre‐treatment (3 min) with PACAP27 also reduced the ability of PACAP27, but not gonadotrophin‐releasing hormone, to cause a spike‐type elevation of cytosolic Ca2+ concentration (a consequence of phosphoinositidase C activation). In chronic desensitization studies, pre‐treatment for 6 h with PACAP27 caused a dose‐dependent (IC50 approximately 10 nM) reduction of PACAP‐stimulated cAMP accumulation and down regulated cell surface PVR1 receptors (to approximately 50%). Thus, it appears that PACAP27‐stimulated (PVR‐1 receptor mediated) adenylyl cyclase undergoes rapid homologous desensitization in αT3‐1 cells, which is paralleled by homologous desensitization of PACAP27‐stimulated phosphoinositidase C activity and involves mechanisms distinct from those underlying heterologous desensitization by phorbol esters. Chronic desensitization of PACAP‐stimulated cAMP accumulation and down‐regulation of cell surface PVR‐1 receptors also occurs in these cells although the receptor loss may not entirely explain the observed desensitization.
Dynamic Variations in Plasma Corticosteroid‐Binding Globulin and Basal HPA Activity following Acute Stress in Adult Rats
Authors: Tannenbaum Beth , Rowe Wayne , Sharma Shakti , Diorio Josie , Steverman Allen , Walker Mathieu , Meaney Michael J.
Published: November 2003

We report on dynamic changes in plasma corticosteroid‐binding globulin (CBG) binding and basal hypothalamic‐pituitary‐adrenal (HPA) activity following acute stress in adult rats. Plasma CBG binding was significantly reduced at 24 and 48 h following a single 60 min period of restraint. Basal levels of plasma ACTH and total corticosterone (B) during the light phase of the cycle were elevated at 24 h following restraint. These effects occurred only when animals were stressed in the light phase of the cycle; animals exposed to restraint stress during the dark phase of the cycle showed no change in plasma CBG binding or in basal HPA activity. Pituitary intracellular transcortin, which is derived from circulating CBG, was also decreased by restaint stress. The decrease in CBG binding was also associated with a significant increase in resting‐state free B levels. Together, these effects produced a substantially (i.e. ∼10‐fold) increased ‘basal’ glucocorticoid signal 24 h following acute stress. These data suggest that the increase in the circulating glucocorticoid signal associated with acute stress endures well beyond the period of increased total B levels.
Evaluation of a health care assistant pilot programme
Authors: Chang A. M. , Lam L. W.
Published: November 2003

Health Care Assistants (HCAs) were piloted in four wards of a large teaching hospital in Hong Kong. Evaluation of this pilot programme was based on patients’ and nurses’ satisfaction with HCAs, the HCAs’ job satisfaction, and the retention rate of HCAs. Data were collected at 3 and 6‐months following the introduction of HCAs to ascertain the level of satisfaction and the rate of HCA retention. Overall, the HCAs’ work was seen as satisfactory and contributing to the work being carried out on each ward. Both nurses and patients were highly satisfied with HCA’s, the mean total levels of satisfaction by nurses being 97 out of a possible range of 26–104 and for patients 53 out of a possible range of 14–56. While there was a high level of nurses’ approval of introducing HCAs into the health care team there were significant differences (P<0.05) with Nursing Officers, followed by Ward Managers being more in agreement than Registered Nurses. There were eight HCA activities seen by more than 70% of nurses to have been carried out frequently. The mean total job satisfaction of HCAs was 67 out of a possible 17–95. Although the 50% retention rate of HCAs was poor, there was overall satisfaction with the work of the HCAs.
Case mix type as a predictor of nursing workload
Authors: Campbell T. , Taylor S. , Callaghan S. , Shuldham C.
Published: November 2003

In the current health care service, the need to measure nursing workload has become the subject of major debate. Attempts have been made to relate workload and nurse staffing, however, despite there being systems for this there appears to be no single recognized formula. Case mix groups have been advocated as a useful tool for measuring nursing workload, particularly in Canada where work continues. Case mix groups work on the basis that patients who are clinically similar and use equivalent resources are grouped using procedure and diagnostic codes. The retrospective study examines the relationship between case mix, resource utilization and nursing effort to determine whether future workload could be predicted using these parameters. The sample included 798 patients and 30 nurses over the period 1993–1994 with analysis of data from the Patient Administration System (PAS) and TEAMWORK, which purports to measure nurse workload. Results showed that there was little relationship between nursing workload and case mix grouping and recommendations are made for future research.
Analysis of job‐share as a process of change
Authors: Taylor B. M.
Published: November 2003

This paper describes the introduction of a district nursing job‐share in a primary health care team. Exploring change theory and different strategies for organizational change, the implications for members of the team are considered. In addition, changes in the balance of power which resulted in conflict within the district nursing team are discussed.
Out to tender — the nurses’ role in awarding the contract for therapeutic bed/mattress hire
Authors: Gray B. , Delve M. , Robinson F.
Published: November 2003

Aim: A project group was established to award the contract for hire of therapeutic beds and mattresses for a large hospital Trust within the United Kingdom National Health Service (NHS).Background: No structure existed for awarding or evaluating such a contract. Involving nurses in the process was intended to bring the decision‐making nearer the patient.Method: The project group consisted of volunteers from a range of clinical nursing grades. They were highly motivated with an interest in pressure sore management. Expertise from NHS Supplies was also involved.Results: The project group successfully awarded the contract, producing a robust operational tool through an objective process. Awareness was raised regarding control of expenditure and a commitment to education. Ongoing evaluation of the contract has also been the responsibility of this group.Conclusion: The project group achieved its aim of awarding a contract that best met the needs of the Trust and continues to monitor that contract. The systematic approach, comprehensive documentation and collaboration with NHS Supplies are felt to contribute to its success. Explicit criteria within the contract provides a clear framework for its monitoring and evaluation.
Management of change: an essential skill for nursing in the 1990s
Authors: Mcphail G.
Published: November 2003

Change is nothing new and indeed has been our only constant, but change today is faster and more complex than it has ever been before (Manion 1994). Bushy (1992) agrees that the past decade has been a time for rapid global changes, with Muller (1992) citing the rapid increase in technology as the root cause. Muller (1992) believes that nurses need to develop a new mindset which is more in tune with the realities of the 1990s, acknowledging that we are and will be living in a constantly changing world, and Zukowski (1995) suggests that regardless of whether or not we accept change, we must learn to manage it. Although change creates uncertainty and discomfort, Poggenpoel (1992) emphasizes that it often leads to real innovation, providing abundant opportunities for creating a better way forward. This paper explores the subject of change management, looking first at the reasons behind the current climate of change in the healthcare system, then outlining change theory in relation to nursing, before discussing the role of the nurse as a change agent.
Introducing change in nursing: the case of research
Authors: Cutcliffe J. R. , Bassett C.
Published: November 2003

This paper examines the issue of encouraging change in nursing and focuses on how to move from task‐orientated to science‐based practice. Therefore, it considers the current theory on the process of change and using two clinical vignettes (one from psychiatric and one from general nursing practice) illustrates how science based practice was introduced. From these vignettes it draws four conclusion: (1) small‐scale cultural change is possible even within large bureaucracies; (2) the nature and identity of change agents is not always immediately obvious; (3) there is arguably no one singular best way of bringing about change and; (4) change activists need to have an understanding of several models of change. It then makes managerial, educational and structural recommendations based on these conclusions.
Prosthetic rehabilitation in the elderly inhabitants of Helsinki, Finland
Authors: NEVALAINEN M.J. , NÄRHI T.O. , SIUKOSAARI P. , SCHMIDT‐KAUNISAHO K. , AINAMO A.
Published: November 2003

The aim of this study was to document the number of remaining natural teeth, to examine the prosthetic rehabilitation and to evaluate further prosthetic treatment needs among a representative sample of 76–86‐year‐old inhabitants of Helsinki. The edentulous made up 46% (168) of the subjects, 40% of the men and 48% of the women. Of these edentulous, 94% (158) wore complete dentures in both jaws, 2% wore only a maxillary denture, and 4% wore no dentures at all. One edentulous subject had an implant‐supported overdenture in the lower jaw. More than half (54%) of all subjects had 1–32 natural teeth left. These dentate subjects had 47% (mean 13·2, excluding the wisdom teeth) of their natural teeth remaining. Of the remaining teeth, 13% (mean 1·8) were crowned and 5% (mean 0·6) were indicated to be extracted. Among the dentate, 37% (mean 10·4) of their natural teeth were missing and replaced by some type of fixed or removable prosthesis. Eleven per cent (mean 3·1) of missing teeth had not been replaced and were considered not to need prosthetic replacement. However, 5% (mean 1·3) of the missing teeth without prosthetic replacement were judged to need a prosthesis. Among the dentate, 37% wore a complete denture in one jaw; 34% of the dentate subjects used acrylic removable partial dentures (ARPD), and 19% used metallic removable partial dentures (MRPD). Of the dentate, 45% had crowns and fixed bridges. Altogether, 25% wore some kind of combination of fixed and removable prosthesis, whereas 14% had no type of prosthetic rehabilitation at all. The age of the current prosthesis varied from less than one year to over 50 years. Of all the subjects, 37% (6% of the edentulous and 63% of the dentate) had experienced inadequate prosthetic rehabilitation.
Peak temperatures of some prosthetic acrylates on polymerization
Authors: VALLITTU P.K.
Published: November 2003

The aim of this study was to determine peak temperatures of some prosthetic acrylic resins at the time of polymerization. The acrylic resins included two temporary restoration resins, three autopolymerizing resins for different applications and one heat‐cured denture base resin. The peak temperatures were measured with a ferro‐constantan thermocouple from test specimens of three different volumes at different temperatures. The results revealed that with increasing volume of polymerizing acrylic resin the peak temperature also increased. In general, acrylic resins for temporary restorations had lower peak temperatures than other acrylic resins. However, despite the lower peak temperatures, the temperature of temporary restoration resins during polymerization can be as high as 82°C. Therefore, to minimize thermal injuries of the tissues of vital tooth, dentists must be aware of the heat formation of the acrylic resins used in the oral cavity.
The effects of adding chlorhexidine and polyhexamethylene bisguanide to a light‐cured periodontal dressing material
Authors: THORSTENSEN A.E.R. , DUGUID R. , LLOYD C.H.
Published: November 2003

The effect of adding two bisguanide antimicrobial agents (chlorhexidine and PHMB) on some physical properties of the light‐cured periodontal dressing material Barricaid® are reported. The physical properties tested were elastic modulus, initial and 10 min recovery strains, and tear stress. The addition of both chlorhexidine and PHMB solutions reduced the elastic modulus as did water. The addition of PHMB to Barricaid® produced greater initial recovery in the strain test than either the addition of chlorhexidine or water, but there were no differences between the treatments after 10 min. Tear stress was also reduced by the addition of water and the chlorhexidine and PHMB solutions. These results suggest that as far as the physical properties of Barricaid® are concerned the addition of the antimicrobial agent PHMB had no long‐term advantages over chlorhexidine.
Pilot study comparing the photoelastic stress distribution for four endodontic post systems
Authors: COHEN B. I. , CONDOS S. , MUSIKANT B. L. , DEUTSCH A. S.
Published: November 2003

This pilot study compared stress distribution using photoelastic blocks for both vertical loading and oblique loading (26° angle) for four groups of post systems (Flexi‐Post®, Flexi‐Flange®, ParaPost® and AccessPost™ dowels). For each group, three test blocks of photoelastic material were prepared with simulated endodontic canals, and the specimens were then photographed. Minimal stresses were observed for all the posts after cementation in the unloaded state. Stress distribution for the Flexi‐Post, Flexi‐Flange and AccessPost were favourable under vertical loading at 134 N and oblique loadings of 89 N and 134 N. Stress patterns were symmetric over the entire length of these posts. Stress distribution for the ParaPost under vertical loading at 134 N generated stress patterns that were asymmetric with concentration of stresses apically compared to coronally. Stress distribution for the ParaPost during oblique loadings of 89 N and 134 N were asymmetric with stress concentrated apically as compared to coronally. Stress distribution for the Flexi‐Post, Flexi‐Flange and AccessPost were all favourable under loading conditions studied.
Loading conditions of endosseous implants in an edentulous human mandible: a three‐dimensional, finite‐element study
Authors: MEIJER H.AJ. , STARMANS F.J.M. , STEEN W.H.A. , BOSMAN F.
Published: November 2003

The design of dental superstructures influences the loading on dental implants and the deformation of the anterior interforaminal bone in an edentulous mandible. This deformation causes stress in the bone around the implants and may lead to bone resorption and loss of the implant. The stress distribution around dental implants in an edentulous mandible was calculated by means of a three‐dimensional, finite‐element model of the anterior part of the jaw. This model was built from data obtained from slices of a single human mandible and was provided with four endosseous implants in the interforaminal region. The implants were either connected with a bar or remained solitary. The solitary implants or the bars were loaded either uniformly or non‐uniformly. In case of a non‐uniform distribution, either the central bar or the central implants were loaded or the lateral bars or the lateral implants were loaded. The most extreme stresses in the bone were always located around the neck of the implant. In the case of the uniform distribution of the loading there were more or less equal extreme principal stresses around the central and lateral implants. If the load was not uniformly distributed on the superstructure then the implant that was nearest to the place of loading showed the highest stress concentration; with connected implants there was a reduction in the magnitude of the extreme principal stresses compared to solitary implants.
Analysis of the articulation after glossectomy
Authors: WAKUMOTO M. , OHNO K. , IMAI S. , YAMASHITA Y. , AKIZUKI H. , MICHI K.‐I.
Published: November 2003

Rehabilitation of the oral cancer patient should aim to achieve not only morphological restoration but also post‐operative functions. However, there are few reports describing quantitative evaluation of the latter. The authors have attempted quantitative evaluation of post‐operative articulatory function after glossectomy, and report the evaluation of it by speech intelligibility, electropalatography (EPG), and acoustical analysis. Subjects were five directly sutured patients and five patients reconstructed with forearm flap, all after glossectomy. The target syllable was /ta/ from among speech intelligibility test samples. The speech intelligibility and acoustical analysis were investigated pre‐operation, and 1, 6 and 12 months post‐operation. EPG data were collected by DP‐01(RION) at 6 months post‐operation. Acoustical analyses were carried out by consonant frequency characteristics and formant variance from consonant to vowel transitions. As a result, subjects reconstructed with a forearm flap showed higher restorative tendency than directly sutured subjects. Articulatory characteristics expected from acoustical analysis were more in agreement with the results of EPG than with the results of the speech intelligibility test. From the results, it was suggested that the acoustical analysis used for this research could reveal changes in articulatory movement and will be useful for quantitatively evaluating post‐operative articulatory functions.
Symptoms of the cervical spine in temporomandibular and cervical spine disorders
Authors: DE WIJER A. , STEENKS M.H. , DE LEEUW J.R.J. , BOSMAN F. , HELDERS P.J.M.
Published: November 2003

This study was performed to assess the prevalence of signs and symptoms related to cervical spine disorders (CSD) in subgroups of patients with temporomandibular disorders (TMD) and to compare TMD patients and CSD patients with regard to the results of orthopaedic cervical spine tests. One hundred and eleven consecutive patients with TMD and 103 consecutive patients with signs and symptoms of CSD were examined. The results indicated that there is a considerable overlap in the signs and symptoms of patients with TMD and patients with CSD. Signs and symptoms on neck extension occurred more often in CSD patients than in subgroups of TMD patients. No significant differences in upper cervical extension, neck flexion, and shoulder girdle function were found between CSD patients and subgroups of patients with TMD. Patients with CSD reported neck pain during active and passive movements of the neck more often than the subgroups of patients with TMD. TMD patients and CSD patients did not differ with regard to pain on shoulder girdle function and palpation of the shoulder girdle. Logistic regression analyses showed that orthopaedic tests of the cervical spine are of minor importance in discriminating between patients with TMD and patients with CSD. It is concluded that TMD with a myogenous involvement in contrast to TMD with only an arthrogenous involvement should no longer be viewed as a local disorder of the stomatognathic system. The upper quarter, including the stomatognathic system, cervical spine, and shoulder girdle, should be evaluated in patients with more complex or persistent symptoms in the head and neck region.
An in vivo quantitative analysis of the fit of Nobel Biocare implant superstructures
Authors: CHESHIRE P.D. , HOBKIRK J.A.
Published: November 2003

Loss of osseointegration of implant fixtures and mechanical failure of superstructures have been attributed to failure to achieve a passive fit between the superstructure and the transmucosal abutment (TMA). The fit of five mandibular superstructures, fabricated on Nobel Biocare implants, was investigated in vivo, using a polyvinyl siloxane impression material to record the discrepancies. Following sectioning of the impressions, the vertical and horizontal discrepancies were analysed at four locations using a travelling microscope. The discrepancies obtained were measured both when the gold cylinder screws were maximally tightened by hand and when tightened with a torque driver to the recommended value of 10 Ncm. The vertical discrepancies for the hand tightened abutments ranged from 0 μm to 63 μm with a mean of 14 μm. In the mechanically tightened group, the vertical discrepancies ranged from 0 μm to 130 μm with a mean of 21 μm. The horizontal discrepancies for the mechanically tightened abutments ranged from 0 μm to 140 μm with a mean of 31 μm, compared with a mean of 46 μm and range of 0 μm to 113 μm, for the hand‐tightened abutments. A close fit was seldom achieved. It is concluded that considerable discrepancies existed around superstructures that had been judged to have a clinically acceptable fit. These were reduced in the vertical direction by hand tightening of the gold screws.
Effect of mixed silanes on the hydrolytic stability of composites
Authors: CRAIG R.G. , DOOTZ E.R.
Published: November 2003

A filler for a urethanedimethacrylate composite was silanated with mixtures of fluoroalkyl‐, aminoalkyl‐, phenyl‐, vinyl‐, bis silyl ethane‐ and 3‐methacryloxypropyltrimethoxysilane (MAOP) in an attempt to increase the hydrophobicity of the coupling agent layer. Diametral tensile strength was used to evaluate composites stored for (1) 24 h in 23°C (RT) air; (2) 24 h in RT air plus 24 h in 100°C air; (3) 24 h in RT air plus 24 h in 100°C water; and (4) 24 h in RT air plus 24 h in 100°C air plus 24 h in 100°C water. Water sorption and solubility of composites was also determined on samples stored for 24 h in RT air. Heating composites for 24 h in 100°C air increased the tensile strength in eight of 13 silane treatments, while heating in 100°C water for 24 h caused decreases for five silane treatments, no change for six and increases in tensile strength for two silane treatments. When composites that had been stored for 24 h at RT plus heated for 24 h in 100°C air were then heated for 24 h in 100°C water, only one silane treatment, the vinyltriethoxysilane at 25% (25% V), showed no significant decrease in tensile strength. Also, the composite silanated with 25% V had the highest value for tensile strength after storing for 24 h at RT air plus 24 h in 100°C air plus 24 h in 100°C water. These data indicate that the use of vinyltriethoxysilane increases the hydrolytic stability of the composite. Water sorption and solubility of the silanated composites were not satisfactory tests for evaluating hydrolytic stability of composites.
Absolute serum hormone levels predict the magnitude of change in anterior knee laxity across the menstrual cycle
Authors: Shultz Sandra J. , Gansneder Bruce M. , Sander Todd C. , Kirk Susan E. , Perrin David H.
Published: November 2003

This study aimed to determine whether absolute sex hormone concentrations predict the magnitude of knee joint laxity changes across the menstrual cycle. Twenty‐two females (18–30 years, body mass index ≤30), who reported normal menstrual cycles for the previous 6 months were tested daily across one complete menstrual cycle for serum levels of estradiol (E = pg/mL), progesterone (P = ng/mL), and testosterone (T = ng/dL), and knee joint laxity (KLax = mm displacement at 134N) measured with a standard knee arthrometer. The change in KLax across the cycle (maximum–minimum), and minimum (early follicular) and peak (postovulatory) hormone concentrations were recorded for each subject. A stepwise linear regression determined if the minimum, peak, or absolute change in hormone concentrations would predict the magnitude of change in KLax across the cycle. KLax changed on average 3.2 ± 1.1 mm across the menstrual cycle (range, 1.5–5.3 mm). Minimum levels of E (39.9 ± 11.8 pg/mL) and P (0.61 ± 0.27 ng/mL), coupled with peak concentrations of E (199.6 ± 54.9 pg/mL) and T (22.5 ± 10.5 ng/dL) explained 57.6% of the change in KLax across the cycle. Greater absolute changes in KLax were observed in response to peak E and T levels when minimum E concentrations were lower and minimum P concentrations were higher in the early follicular phase. The absolute minimum concentrations of E and P in the early follicular phase appear to be important factors in determining the sensitivity of the knee joint's response to changing hormone levels. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Mentoring state hospital nurses to write
Authors: Davidhizar R. , Cosgray R.
Published: November 2003

There is a shortage of clinical nurses, particularly in the area of psychiatric nursing, who feel competent and comfortable writing for publication. This is unfortunate since clinical nurses have valuable experiences to share, to promote and advance the nursing profession. This manuscript describes the work of one Director of Nursing at a state hospital who mentored the nursing staff to write for publication. Over a period of five years some 28 articles have been published by nurses at this hospital. This success in publication has led to an increase in self‐esteem among nurses, an increased willingness to share their writing experiences with others, and increased numbers of workshop presentations on clinical subjects. This article describes how the mentoring process can be used to promote authorship, and specifically, how it was used at this one hospital.