bluuebunny/crossref_metadata_2025_split huggingface dataset:
Osmosis in small pores: a molecular dynamics study of the mechanism of solvent transport
Authors: Kim K. S. , Davis I. S. , Macpherson P. A. , Pedley T. J. , Hill A. E. 
Published: November 2004

Osmosis through semi–permeable pores is a complex process by which solvent is driven by its free energy gradient towards a solute–rich reservoir. We have studied osmotic flow across a semi–permeable cylindrical pore using hard–sphere molecular dynamics which simulates osmosis in the absence of attractive forces between solute and solvent. In addition, we recorded the rates of pressure–driven solvent flow and the diffusive flow of labelled solvent under concentration gradients. It is apparent that there are differences, which are radius dependent, between viscous and diffusive solvent permeabilities in small pores.The osmotic flow rate is decreased by allowing solute entry into part of the pore, an effect which is not due to solute obstruction. The flow rate is dependent on the structure of the pore, which for asymmetric pores leads, surprisingly, to flow asymmetry or osmotic rectification. In the absence of any possible viscous rectification at these very low flow rates the effect correlates with changes between diffusive and pressure flows created by the presence of solute, an effect which has been predicted from thermodynamic arguments. The geometry of a semi–permeable pore in relation to the solute size is therefore required to predict the osmotic flow rate, a departure from the classical picture.Finally, by extracting transport parameters from simulations with pure solvent, we examine the departure of observed flow rate from that predicted by continuum mechanics, obtaining drag coefficients which we compare with those derived from hydrodynamics alone.
Dynamics of Individual Wealth Accumulation: A Use of Simulation Methods for Estimating Limited Dependent‐Variables Models
Authors: Lollivier Stéfan 
Published: November 2004

This paper presents an estimation of the behaviour of wealth accumulation, carried out on panel data. One of the aims of the study is to test some of the predictions resulting from the buffer‐stock model of saving, especially the unit permanent income elasticity of wealth accumulation and the shape of the age profile.However, in the data available the wealth variable is not continuous. It is known only through a system of eleven intervals. Therefore, methods based on the use of the simulator by Geweke, Hajivassiliou and Keane have been implemented estimators.
International Migration and the Role of Remittances in Eastern Europe
Authors: León‐Ledesma Miguel , Piracha Matloob 
Published: November 2004

AbstractIn this paper we analyse the effect of remittances on employment performance for Central and East European (CEE) economies. We show that the impact of remittances on unemployment depends on its effect on productivity growth and investment. In order to empirically analyse the impact of remittances we estimate a productivity equation using a set of 11 transition countries during the 1990 to 1999 period. Our results show support for the view that remittances have a positive impact on productivity and employment both directly and indirectly through its effect on investment.
Retinol binding protein isolated from acute renal failure patients inhibits polymorphonuclear leucocyte functions
Authors: Cohen G. , Hörl W. H. 
Published: November 2004

AbstractBackground  Protein factors accumulating in sera of patients with end‐stage renal disease (ESRD) that interfere with the nonspecific immune response by inhibiting essential functions of polymorphonuclear leucocytes (PMNLs) have previously been described. No such factor has been isolated from acute renal failure (ARF) patients to date.Materials and methods  Using a three‐step chromatographic procedure involving ion exchange, size exclusion and hydrophobic interaction chromatography we purified the apo‐ and holo‐form of retinol binding protein (RBP) from high‐flux dialyser (polyacrylonitrile; AN69) ultrafiltrates of patients with ARF. Their effect on the chemotaxis of PMNLs isolated from healthy donors was determined by the under‐agarose method. Whole‐blood assays applying flow cytometry were used to assess phagocytosis and the oxidative metabolism of PMNLs. Apoptosis was assessed by determining the DNA content using propidium iodide.Results  Isolated apo‐ and holo‐forms of RBP were truncated on their C‐terminus as determined by mass spectrometry. All isolates significantly inhibited the chemotactic movement of PMNLs obtained from healthy donors and the PMNL oxidative metabolism stimulated by E. coli. These effects were concentration dependent. Retinol binding protein had no influence on the PMNL oxidative metabolism stimulated by PMA and on PMNL phagocytosis. Commercially available RBP isolated from urine influenced PMNL functions in the same way. Inhibition of p38 mitogen‐activated protein kinase (MAPK) by SB203580 significantly attenuated the phagocytosis‐induced respiratory burst and RBP did not lead to a further decrease. Polymorphonuclear leucocyte apoptosis was significantly inhibited by RBP.Conclusions  The apo‐ and holo‐forms of RBP isolated from the ultrafiltrate of ARF patients inhibit PMNL chemotaxis, oxidative metabolism and apoptosis. Therefore, RBP may be considered a uraemic toxin contributing to a disturbed immune defence.
Oxygen consumption is increased relative to work rate in patients with McArdle's disease
Authors: O'Dochartaigh C. S. , Ong H. Y. , Lovell S. M. , Riley M. S. , Patterson V. H. , Young I. S. , Nicholls D. P. 
Published: November 2004

AbstractBackground Patients with McArdle's disease suffer exercise incapacity as a result of myophosphorylase deficiency, and for a given work rate have excessive circulatory and ventilatory responses. We hypothesized that the rate of increase of oxygen consumption with work rate (ΔVO2‐ΔWR slope) would also be elevated in such patients as a result of these excessive responses.Patients and methods Five patients with McArdle's disease and five matched controls carried out a maximal incremental cardiopulmonary exercise test. Controls then carried out a second test matched to the maximal test of a paired patient. Venous blood was sampled at rest, peak exercise and recovery.Results During the matched test, the ΔVO2‐ΔWR slope was higher in the patients than in the controls [19·9 (15·0–24·6) vs. 11·7 (9·2–13·5) mL min−1 W−1; mean (range);P = 0·022], and the peak‐achievedVO2was also greater in the patient group [1201 (890–1575) vs. 918 (599–1248) mL min−1;P = 0·003]. A similar pattern was observed for heart rate [173 (165–182) vs. 108 (105–134) b.p.m.;P = 0·001] and plasma norepinephrine levels [12·6 (9·2–19·9) vs. 2·9 (2·2–4·9) nmol l−1;P = 0·003].Conclusion There is an increased rate of rise inVO2relative to work rate during exercise in patients with McArdle's disease. There is also a greater rise in catecholamines, which may be the result of a physiological response to substrate starvation, and is likely to contribute to the increase inVO2.
Nurse–patient relationships in palliative care
Authors: Mok Esther , Chiu Pui Chi 
Published: November 2004

Aim.  The aim of this paper is to report a study exploring aspects of nurse–patient relationships in the context of palliative care.Background.  Although there are numerous studies addressing nurse–patient relationships, little research has focused on these in the context of palliative are. Furthermore, no previous study has examined the relationship in the Chinese context.Methods.  Qualitative data were collected from 10 hospice nurses and 10 terminally ill patients by means of open ended unstructured interviews. Respondents were asked to reflect on practices and incidents that would allow an understanding of the meaning of nurse–patient relationships in palliative care.Results.  Four major categories emerged from the perspectives of patients and nurses: (1) forming a relationship of trust; (2) being part of the family; (3) refilling with fuel along the journey of living and dying; and (4) enriched experiences. Responses revealed that a relationship of trust is formed, and that nurses are not only regarded as health professionals, but also become part of the family or a good friend. Nurses who develop trusting relationships demonstrate a holistic approach to caring, show their understanding of patients’ suffering, are aware of their unvoiced needs, provide comfort without actually being asked, and are reliable, proficient, competent and dedicated in their care.Conclusion.  Trust, the achievement of the goals of patients and nurses, caring and reciprocity are important elements of nurse–patient relationships in palliative care. Such relationships not only improve patients’ physical and emotional state, but also facilitate their adjustment to their illness, ease pain and can ultimately lead to a good death experience. It is nurses’ personal qualities and skills, which are embedded in these relationships, that constitute excellence in nursing care. Nurses also derive satisfaction and are enriched through the relationships.
A framework for the introduction and evaluation of advanced practice nursing roles
Authors: Bryant‐Lukosius Denise , DiCenso Alba 
Published: November 2004

Aim.  This paper describes a participatory, evidence‐based, patient‐focused process for advanced practice nursing (APN) role development, implementation, and evaluation (PEPPA framework).Background.  Despite the growing demand for advanced practice nurses, there are limited data to guide the successful implementation and optimal utilization of these roles. The participatory, evidence‐based, patient‐focused process, for guiding the development, implementation, and evaluation of advanced practice nursing (PEPPA) framework is an adaptation of two existing frameworks and is designed to overcome role implementation barriers through knowledge and understanding of APN roles and environments. The principles of participatory action research directed the construction of the new framework.Conclusions.  The process for implementing and evaluating APN roles is as complex and dynamic as the roles themselves. The PEPPA framework is shaped by the underlying principles and values consistent with APN, namely, a focus on addressing patient health needs through the delivery of coordinated care and collaborative relationships among health care providers and systems. Engaging environmental stakeholders as participants in the process provides opportunity to identify the need and shared goals for a clearly defined APN role. The process promotes increased understanding of APN roles and optimal use of the broad range of APN knowledge, skills, and expertise in all role domains and scope of practice. The steps for planning and implementation are designed to create environments to support APN role development and long‐term integration within health care systems. The goal‐directed and outcome‐based process also provides the basis for prospective ongoing evaluation and improvement of both the role and delivery of health care services.
Iontophoresis with glycopyrrolate for the treatment of palmoplantar hyperhidrosis
Authors: Dolianitis Con , Scarff Catherine E , Kelly John , Sinclair Rodney 
Published: November 2004

SUMMARY To determine the comparative efficacy of tap water iontophoresis to iontophoresis with the anticholinergic glycopyrrolate, we undertook a single‐blinded right–left comparison study in 20 patients with palmoplantar hyperhidrosis. Most patients had their palms treated and one patient had the soles treated. We compared the duration of symptom relief following iontophoresis with glycopyrrolate unilaterally to iontophoresis with glycopyrrolate bilaterally. Patients filled in daily efficacy assessment cards. Each palm was rated as ‘dry’, ‘slightly wet’, ‘moderately wet’ or ‘very wet’. Following treatment with unilateral tap water iontophoresis, unilateral glycopyrrolate and bilateral glycopyrrolate, patients reported hand dryness for a median of 3, 5 and 11 days, respectively. As the data was paired, treatment differences were analysed using a sign‐rank test. Bilateral glycopyrrolate was superior to both unilateral glycopyrrolate and tap water in most patients. Unilateral glycopyrrolate was superior to tap water in most patients. All differences between groups were found to be statistically significant. We postulate that the increased efficacy of bilateral glycopyrrolate when compared with unilateral glycopyrrolate relates to its systemic absorption. We conclude that glycopyrrolate iontophoresis is more effective than tap water iontophoresis in the treatment of palmoplantar hyperhidrosis and that glycopyrrolate iontophoresis has both local and systemic effects on perspiration.
Evidence for rapid auditory perception as the foundation of speech processing: a sparse temporal sampling fMRI study
Authors: Zaehle T. , Wüstenberg T. , Meyer M. , Jäncke L. 
Published: November 2004

AbstractWe examined the processing of verbal and nonverbal auditory stimuli using an event‐related functional magnetic resonance imaging (fMRI) study to reveal the neural underpinnings of rapid temporal information processing and it's relevance during speech perception. In the context of a clustered sparse‐temporal fMRI data collection eight right‐handed native German speakers performed: (i) an auditory gap detection task; and (ii) a CV syllable discrimination task. A tone perception task served as a nontemporal control condition. Here we aimed to research to what extent the left hemisphere preferentially processes linguistically relevant temporal information available in speech and nonspeech stimuli. Furthermore, we sought to find out as to whether a left hemisphere's preference for linguistically relevant temporal information is specifically constrained to verbal utterances or if nonlinguistic temporal information may also activate these areas. We collected haemodynamic responses from three time points of acquisition (TPA) with varying temporal distance from stimulus onset to gain an insight on the time course of auditory processing. Results show exclusively left‐sided activations of primary and secondary auditory cortex associated with the perception of rapid temporal information. Furthermore, the data shows an overlap of activations evoked by nonspeech sounds and speech stimuli within primary and secondary auditory cortex of the left hemisphere. The present data clearly support the assumption of a shared neural network for rapid temporal information processing within the auditory domain for both speech and nonspeech signals situated in left superior temporal areas.
Two populations of cold‐sensitive neurons in rat dorsal root ganglia and their modulation by nerve growth factor
Authors: Babes Alexandru , Zorzon Daniel , Reid Gordon 
Published: November 2004

AbstractCold sensing in mammals is not completely understood, although significant progress has been made recently with the cloning of two cold‐activated ion channels, TRPM8 and TRPA1. We have used rat DRG neurons in primary culture and calcium fluorimetry to identify distinct populations of cold‐sensitive neurons, which may underlie different functions. Menthol sensitivity clearly separated two classes of cold‐responding neurons. One group was menthol‐sensitive (MS), was activated at warmer temperatures and responded faster and with a larger increase in intracellular calcium concentration during cooling; the fraction of MS neurons in culture and their cold sensitivity were both increased in the presence of nerve growth factor. Neurons in the menthol‐insensitive (MI) group required stronger cooling for activation than MS cells and neither their proportion nor their cold sensitivity were significantly altered by nerve growth factor. The two groups of cold‐sensitive neurons also had different pharmacology. A larger fraction of MS cells were capsaicin‐sensitive and coexpression of menthol and capsaicin sensitivity was observed in the absence of NGF. MI neurons were not stimulated by the super‐cooling agent icilin or by the irritant mustard oil. Taken together these findings support a picture in which TRPM8 is the major player in detecting gentle cooling, while TRPA1 does not seem to be involved in cold sensing by MI neurons, at least in the temperature range between 32 and 12 °C.
Subregional changes in discharge rate, pattern, and drug sensitivity of putative GABAergic nigral neurons in the kindling model of epilepsy
Authors: Gernert Manuela , Fedrowitz Maren , Wlaz Piotr , Löscher Wolfgang 
Published: November 2004

AbstractThe substantia nigra pars reticulata (SNr) is thought to act as a seizure‐gating mechanism in kindling and other epilepsy models. We investigated whether the kindling process induces site‐specific (anterior‐posterior) and seizure‐outlasting alterations in the activity of putative GABAergic SNr neurons and in their response to pharmacological manipulation. Female Wistar rats were kindled via the basolateral amygdala by daily stimulation.In vivoextracellular single unit recordings of SNr neurons were performed in kindled rats 1 day after a generalized seizure in order to examine activity changes that outlast the kindled seizures. Sham‐kindled and naive rats served as controls. We found a significant and seizure‐outlasting increase of discharge rates within the posterior but not within the anterior SNr of kindled rats when compared to controls. Furthermore, kindling resulted in seizure‐outlasting burst‐like firing pattern of SNr neurons. The antiepileptic drug valproic acid (VPA; 100 mg/kg i.v.) significantly reduced SNr discharge rates in all animal groups. Interestingly, neurons located in the anterior SNr of kindled rats were significantly less depressed by VPA compared to the reduction obtained in naive controls. The present data disclose kindling induced functional plasticity within basal ganglia regions. The findings are relevant for a better understanding of the mechanisms underlying the seizure‐gating function of the SNr and might provide new targets for rational therapeutic manipulations, which aim to establish a remote control of epileptic seizures.
Spinal implantation of hNT neurons and neuronal precursors: graft survival and functional effects in rats with ischemic spastic paraplegia
Authors: Marsala Martin , Kakinohana Osamu , Yaksh Tony L. , Tomori Zoltan , Marsala Silvia , Cizkova Dasa 
Published: November 2004

AbstractTransient spinal ischemia, a complication associated with aortic cross‐clamp may lead to spastic paraplegia. Once fully developed this deficit is permanent. Quantitative histopathological assessments and pharmacological studies show that the ischemic spasticity is secondary to the loss of lumbar GABA and glycinergic inhibitory interneurons. In the present study, we investigated whether human hNT neurons or committed Sprague–Dawley rat spinal neuronal precursors (SNPs) when grafted into previously ischemic spinal segments depleted of inhibitory neurons would restore local inhibitory tone and ameliorate spasticity. Rats with functionally and electrophysiologically defined spasticity that received spinal graft of hNT neurons or neuronal precursors and immunosuppressive treatment displayed a progressive recovery of motor function that correlated with the improvement of otherwise exacerbated peripheral motor response evoked by stimulation of motor cortex. In contrast, in control, medium‐injected or oligodendrocyte‐grafted animals no significant therapeutic effect was seen. Stereological quantification of grafted neurons revealed 1–2% survival at three months after transplantation. These surviving neurons displayed a robust axo‐dendritic sprouting and expression of markers typical of mature neurons including NSE, NeuN and synaptophysin. In both treatment groups a subpopulation of grafted neurons developed GABA immunoreactivity. These data provide evidence that a region specific grafting of hNT neurons or other neuronally committed cells, which have a potential to develop inhibitory neurotransmitter phenotype, represent an effective treatment modality to modulate ischemia‐induced spastic paraplegia.
Chronic interleukin‐6 exposure alters metabotropic glutamate receptor‐activated calcium signalling in cerebellar Purkinje neurons
Authors: Nelson Thomas E. , Netzeband Jeffrey G. , Gruol Donna L. 
Published: November 2004

AbstractChronic central nervous system expression of the cytokine interleukin‐6 (IL‐6) is thought to contribute to the histopathological, pathophysiological, and cognitive deficits associated with various neurological disorders. However, the effects of chronic IL‐6 expression on neuronal function are largely unknown. Previous studies have shown that chronic IL‐6 exposure alters intrinsic electrophysiological properties and intracellular Ca2+ signalling evoked by ionotropic glutamate receptor activation in cerebellar Purkinje neurons. In the current study, using primary cultures of rat cerebellum, we investigated the effects of chronic IL‐6 exposure on metabotropic glutamate receptor (mGluR)‐activated Ca2+ signalling and release from intracellular Ca2+ stores. Chronic exposure (6–10 days) of Purkinje neurons to 500 units/mL IL‐6 resulted in elevated resting Ca2+ levels and increased intracellular Ca2+ signals evoked by the group I mGluR agonist (S)‐3,5‐dihydroxyphenylglycine (DHPG) compared to untreated control neurons. Chronic IL‐6 treatment also augmented Ca2+ signals evoked by brief 100 mm K+ depolarization, although to a lesser degree than responses evoked by DHPG. Depleting intracellular Ca2+ stores with sarcoplasmic‐endoplasmic reticulum ATPase inhibitors (thapsigargin or cyclopiazonic acid) or blocking ryanodine receptor‐dependent release from intracellular stores (using ryanodine) resulted in a greater reduction of DHPG‐ and K+‐evoked Ca2+ signals in chronic IL‐6‐treated neurons than in control neurons. The present data show that chronic exposure to elevated levels of IL‐6, such as occurs in various neurological diseases, alters Ca2+ signalling involving release from intracellular stores. The results support the hypothesis that chronic IL‐6 exposure disrupts neuronal function and thereby may contribute to the pathophysiology associated with many neurological diseases.
Medial prefrontal cortical integration of psychological stress in rats
Authors: J. McDougall S. , Widdop Robert E. , Lawrence Andrew J. 
Published: November 2004

AbstractThe present study aimed to determine whether the medial prefrontal cortex (mPFC) (prelimbic and infralimbic regions) is implicated in the integration of a stress response. Sprague‐Dawely rats were implanted with telemetry probes and guide cannulae so that either muscimol or vehicle could be administered locally within the mPFC or dorsomedial hypothalamus (DMH). The heart rate and blood pressure of rats was continuously recorded as either muscimol or vehicle was administered centrally and rats were either exposed to restraint stress or left alone in their home cages. After the stress challenge, or equivalent period, rats that had received intra‐mPFC injections were processed for immunohistochemical detection of Fos throughout the neuraxis. Bilateral microinjection of muscimol into the mPFC had no effect upon either baseline cardiovascular parameters or restraint stress‐induced tachycardia or pressor responses whereas, in the DMH, pretreatment with muscimol attenuated the cardiovascular stress response. Analysis of Fos expression throughout the CNS of nonstressed rats showed no effect of muscimol injections into the mPFC on baseline expression in the nuclei examined. In contrast, rats that had received muscimol injections into their mPFC and were subsequently restrained exhibited an increase in the number of Fos‐positive cells in the DMH, medial amygdala, and medial nucleus tractus solitarius as compared to vehicle‐injected rats that experienced restraint stress. These results indicate that, during acute psychological stress, the mPFC does not modulate the cardiovascular system in rats but does inhibit specific subcortical nuclei to exert control over aspects of an integrated response to a stressor.