bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of remifentanil and alfentanil on seizure duration, stimulus amplitudes and recovery parameters during ECT
Authors: Akcaboy Z N. , Akcaboy E Y. , Yigitbas B. , Bayam G. , Dikmen B. , Gogus N. , Dilbaz N. 
Published: August 2005

Background and objective:  Propofol may decrease seizure duration in electroconvulsive therapy. Although not proven, prolonged seizures may be more efficacious. The goal of this study was to evaluate and compare effects of alfentanil and remifentanil on seizure duration, recovery parameters and degree of stimulus amplitude in patients undergoing electroconvulsive therapy.Methods:  Twenty‐four ASA I–II patients enrolled in this prospective, randomized trial, each receiving a total of seven electroconvulsive therapies. Patients were randomized to receive only Propofol, group P (0.75 mg kg−1, n = 8), Propofol with alfentanil, group A (10 µg kg−1 alfentanil + 0.5 mg kg−1 Propofol, n = 8) and Propofol with remifentanil, group R (1 µg kg−1 remifentanil +0.5 mg kg−1 propofol, n = 8) via an iv route. Supplemental doses of propofol were given as required to achieve loss of consciousness. Succinylcholine 0.5 mg kg−1 iv was given to all groups for muscular paralysis. We recorded hemodynamic parameters, cortical and motor seizure durations, and recovery parameters.Results:  Mean motor seizure duration was found to be significantly longer in patients receiving propofol‐remifentanil anesthesia (53.3 ± 13.6 s) and propofol‐alfentanil anesthesia (52.2 ± 0.4 s) compared with propofol anesthesia (37.6 ± 9.2 s) (P = 0.001). Recovery parameters and stimulus amplitudes were similar in groups A and R; significantly different from group P (P = 0.001).Conclusions:  Adding 10 µg kg−1 alfentanil or 1 µg kg−1 remifentanil to reduced doses of propofol provided unconsciousness and increased seizure durations. For patients who need higher stimulus amplitudes for longer seizure durations, combining low‐dose propofol with alfentanil or remifentanil may be good alternative regimens for ECT.
Bradycardia and hypertension in anticipation of, and exacerbated by, peribulbar block: a prospective audit
Authors: Van Den Berg A. A. 
Published: August 2005

Background:  Changes in heart rate (HR), systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) occur in anticipation of, and following, injection of a peribulbar local analgesic agent. We examined these changes in two groups of awake patients given a pre‐medication of either hydroxyzine 1.0 mg/kg alone (control) or hydroxyzine 1.0 mg/kg with morphine 0.05 mg/kg.Methods:  HR, SAP and DAP of 100 patients per group were monitored the day before surgery (baseline), every 5 min in the anesthesia holding room before peribulbar injection, every minute for the first 5 min after peribulbar injection and then every 5 min until transfer to the operating room. Within and between pre‐medication group values of HR, SAP and DAP before and after peribulbar injection were compared with baseline.Results:  The two groups of patients were similar. Before peribulbar injection, HR was unchanged in the hydroxyzine group, but 6% slower in those given morphine (P < 0.01). After injection, HR slowed in both groups, by 5% and 7% (P < 0.01, both comparisons), respectively. In anticipation of injection, SAP increased in both groups to 20% and 16% above baseline, respectively, and increased further after injection to 26% and 24% above baseline, respectively (P < 0.001, all comparisons). In both groups, maximum SAP following injection exceeded maximum SAP before injection (P < 0.02, both comparisons). DAP increased by 4% (P < 0.05) in the hydroxyzine group before injection, and by 5% and 4%, respectively (P < 0.005 and P < 0.05, respectively) after peribulbar injection.Conclusion:  The audit reveals pronounced increases in SAP accompanied by lesser increases in DAP and a tendency to slowing of HR in awake patients in anticipation of peribulbar injections. Peribulbar injections cause further increases in blood pressure and mild bradycardia. These changes occur similarly in patients pre‐medicated with hydroxyzine or hydroxyzine plus morphine. A mix of neuro‐humoral influences (anxiety/catecholamine/baroreceptor/trigemino‐vagal) are postulated as etiological.
Inter‐observer agreement of tests used for prediction of difficult laryngoscopy/tracheal intubation
Authors: Rosenstock C. , Gillesberg I. , Gätke M. R. , Levin D. , Kristensen M. S. , Rasmussen L. S. 
Published: August 2005

Background:  Guidelines recommend pre‐operative airway evaluation for the prediction of airway management difficulties. Combining tests for evaluation increases the accuracy of the assessment. One model including seven parameters transformed into a simplified airway risk index (SARI) has been proven to be valid. We determined the inter‐observer agreement of the specific test combinations included in SARI as well as of the total score.Methods:  Four observers assessed 136 patients, 120 without and 16 with a difficult airway history. Two residents and two specialists in anaesthesia performed the airway assessment consisting of the measurement of the mouth opening, the thyromental distance (TMD), the ability to protrude the mandible and an evaluation of the Mallampati class and head and neck mobility. Body weight was also recorded. Inter‐observer agreement between specialists and residents, separately, was analysed using kappa statistics and Spearman's correlation analysis and the limits of agreement were evaluated using the 95% confidence interval. The agreement between pairs of assessors was also evaluated.Results:  The inter‐observer agreement was good to excellent for both specialists and residents when measuring mouth opening (Spearman's correlation coefficient R = 0.88–0.97) and the horizontal distance between the upper and lower incisors during jaw protrusion (R = 0.56–0.97). The Mallampati classification assessment demonstrated satisfactory to complete inter‐observer agreement (κ = 0.41–1). The assessment of TMD and neck mobility showed considerable discrepancies between observers.Conclusions:  We demonstrated good inter‐observer agreement using three tests from SARI and recommend the Mallampati classification, mouth opening and ability of jaw protrusion for pre‐operative airway evaluation. A simplification of the assessment of TMD and neck mobility is warranted.
Ethical issues in intensive care – a survey among Scandinavian intensivists
Authors: Tallgren M. , Klepstad P. , Petersson J. , Skram U. , Hynninen M. 
Published: August 2005

Background:  The general principles of medical ethics are universally accepted. In practice, however, there is variation on how these principles are interpreted by people with different cultural backgrounds. The aim of this study was to document the views of Scandinavian intensive care physicians on intensive care unit (ICU) admission, triage, withholding and withdrawal of intensive care, and communication between the patient, the family and the ICU team.Methods:  A questionnaire was developed and sent to 84 intensive care physicians working in Denmark, Finland, Sweden and Norway.Results:  The response rate was 61%. In general, the responses were in agreement with published guidelines. Nevertheless, there was considerable variation on what factors are taken into account when priority decisions are made. In addition, the views on the content of information provided to the family varied. A majority of 80% reported priority decisions being made on a regular basis. Less than one‐half of the respondents had correct knowledge regarding the existence or lack of national guidelines on intensive care ethics. Only 8% of the respondents were aware of guidelines published by the Society of Critical Care Medicine.Conclusion:  Variation in priority determinants between individual physicians may compromise justice in health care. An effort should be made to discuss and adopt mutual principles. In addition, the quality of information available to the patients' representatives deserves our attention. The results of this study could be used as a basis for discussion when guidelines on the ethical aspects of intensive care are developed and reviewed.
Nitrous oxide diffusion into tracheal tube cuffs – efficacy of a new prototype cuff pressure release valve
Authors: Dullenkopf A. , Gerber A. C. , Weiss M. 
Published: August 2005

Background:  The aim of this study was to evaluate the performance of a new cuff pressure release valve (CPRV), in which the release pressure can be adjusted from 10 to 25 cmH2O, particularly intended to control pressure in paediatric cuffed tracheal tubes and to avoid cuff hyperinflation caused by N2O diffusion.Methods:  In vitro: the PRV was set to 10, 15, 20 or 25 cmH2O release pressure and connected to a cuffed tube placed into a box flushed with 66% N2O in O2. The cuff pressure was monitored with and without CPRV for 60 min. Experiments were performed four times using two different CPRVs. In vivo: with Institutional Review Board approval, CPRV was studied in 50 children undergoing general anaesthesia with tracheal intubation and standardized anaesthesia technique (including 66% N2O in O2) and ventilator settings. Patients were randomized into two groups (with and without CPRV). The cuff pressure baseline was 20 cmH2O and CPRV was set to 25 cmH2O. If the cuff pressure exceeded 25 cmH2O, it was manually released to 20 cmH2O. The numbers of deflations in both groups were noted and compared by Mann–Whitney U‐test (P < 0.05).Results:  In vitro: the cuff pressure exceeded 50 cmH2O after 60 min without CPRV, but did not exceed the settings with CPRV. In vivo: there was no need to manually deflate the cuff in the CPRV group but, in every patient in the control group, three (two to seven) deflating manoeuvres were required within the first hour of anaesthesia (P < 0.0001).Conclusion:  The CPRV allows reliable cuff pressure release at various pressure levels and reliably prevents cuff pressure increases caused by N2O.
In vivo characterization of the angiotensin‐(1–7)‐induced dopamine and γ‐aminobutyric acid release in the striatum of the rat
Authors: Stragier Bart , Hristova Ilina , Sarre Sophie , Ebinger Guy , Michotte Yvette 
Published: August 2005

AbstractThe effect of angiotensin (Ang)‐1–7 on dopamine, γ‐aminobutyric acid (GABA) and glutamate release in the striatum of the rat was examined using in vivo microdialysis. Ang‐(1–7) was administered locally in the striatum through the microdialysis probe. At a concentration of 100 µm, Ang‐(1–7) caused a significant increase in extracellular dopamine and GABA but had no effect on glutamate release. The Ang‐(1–7)‐induced dopamine release was blocked by EC33, an inhibitor of aminopeptidase A, an enzyme which converts Ang‐(1–7) into Ang‐(3–7), suggesting that this effect occurs after metabolism into Ang‐(3–7). Indeed, administration of Ang‐(3–7) (10–100 µm) into the striatum caused a more potent increase in the striatal dopamine release than Ang‐(1–7). Because Ang‐(3–7) is an inhibitor of insulin‐regulated aminopeptidase (IRAP) and because Ang IV, another IRAP inhibitor, also causes a concentration‐dependent increase in dopamine in the rat striatum, IRAP may be involved in this effect. In contrast, EC33 had no effect on the Ang‐(1–7)‐induced GABA increase but the GABA release was blocked by the putative AT1‐7 receptor antagonist A779 (0.1 µm) and by the nitric oxide synthase inhibitor L‐NAME (1 mm). These drugs could not block the effect of Ang‐(1–7) on the striatal dopamine release suggesting that only the observed effects on GABA release are mediated by the AT1‐7 receptor and/or are associated with a release of nitric oxide.
Spatio‐temporal Ca2+ dynamics of moth olfactory projection neurones
Authors: Carlsson Mikael A. , Knüsel Philipp , Verschure Paul F. M. J. , Hansson Bill S. 
Published: August 2005

AbstractWe studied the Ca2+ dynamics of odour‐evoked glomerular patterns in the antennal lobe of the moth Spodoptera littoralis using optical imaging. Here we selectively stained a large population of antennal lobe output neurones, projection neurones, by retrograde filling with FURA‐dextran from the inner antennocerebral tract in the protocerebrum. Different plant‐associated odorants evoked distributed patterns of activated glomeruli that were odour dependent and repeatable. These patterns were, however, dynamic during the period of odour exposure. Temporal responses differed across glomeruli and were stimulus dependent. Next we examined how the correlations between patterns evoked by different odorants changed with time. Initially, responses to structurally similar compounds were highly correlated, whereas responses to structurally different compounds differed. Within the period of odour exposure (1 s) we found a significant reduction in similarity of responses evoked by different odours, irrespective of initial similarity, whereas trial‐to‐trial correlations remained high. Our results suggested an ability for coarse classification at the initial encounter with an odour source. With time, however, the discrimination ability increases and structurally similar odours can be distinguished.
Up‐regulation of VGLUT2 expression in hypothalamic‐neurohypophysial neurons of the rat following osmotic challenge
Authors: Kawasaki Akiko , Hoshi Koichi , Kawano Michihiro , Nogami Haruo , Yoshikawa Hiroyuki , Hisano Setsuji 
Published: August 2005

AbstractA second vesicular glutamate transporter (VGLUT2) has been reported to be expressed in neurosecretory neurons of the hypothalamic‐neurohypophysial system. To study its role in the neurosecretory neurons, we evaluated the expression of the VGLUT2 gene in the paraventricular (PVN) and supraoptic (SON) nuclei as well as the immunoreactivity in the neurohypophysis under euhydrated and chronic hyperosmotic conditions with in situ hybridization and immunohistochemistry. The intensity of hybridization signals in the PVN, SON and thalamus of rats subjected to water deprivation for 7 days, or drinking 2% NaCl for 4 or 7 days, was compared with that of euhydrated rats (control). The overall intensity in the entire PVN or SON, but not the thalamus, was higher in osmotically stimulated rats than in controls. Within the PVN, a significantly higher intensity of signals than that of controls was found only in the dorsolateral posterior magnocellular region in 4‐day salt‐loaded rats and in all subregions in water‐deprived or 7‐day salt‐loaded rats. The intensity in the SON was higher in the stimulated rats than in controls, regardless of subregions. In the neurohypophysis, VGLUT2 staining was frequently localized in vasopressin terminals of control rats and was apparently reduced in stimulated rats. These results indicate that VGLUT2 is principally expressed in magnocellular vasopressin neurons, suggesting some local effect of intrinsic glutamate on neurohypophysial hormone secretion.
Purkinje cell spinogenesis during architectural rewiring in the mature cerebellum
Authors: Cesa Roberta , Morando Laura , Strata Piergiorgio 
Published: August 2005

AbstractSpines can grow and retract within hours of activity perturbation. We investigated the time course of spine formation in a model of plasticity involving changes in brain architecture where spines of a dendritic domain become innervated by a different neuronal population. Following a lesion of rat olivocerebellar axons, by severing the inferior cerebellar peduncle, new spines grow on the deafferented proximal dendrite of the Purkinje cells (PCs) and these new spines become innervated by parallel fibres (PFs) that normally contact only the distal dendrites. The varicosities of climbing fibre (CF) terminal arbors disappear within 3 days of the lesion. Spine density in the proximal dendritic domain begins to rise within 3 days and continues to increase towards a plateau at 6–8 days. In ‘slow Wallerian degeneration’ mice, in which axonal degeneration is delayed, climbing fibre varicosities virtually disappear at 14 rather than 3 days. Spine density in the proximal dendritic domain is similar to control Purkinje cells up to 14 days and increases significantly 18 days postlesion. The delayed spinogenesis in the latter mutant is the result of a persistence of the climbing fibre presynaptic structure in the absence of activity. Therefore, climbing fibre activity itself is not directly responsible for the suppression of spine formation, but suppression mechanisms tend to become weaker as long as the structural dismantling of the presynaptic varicosities proceeds. Thus, spinogenesis is guided by two different mechanisms; a rapid one related to changes in homotypic remodeling and a slower one, which requires the removal of a competitive afferent.
Nerve growth factor‐induced circadian phase shifts and MAP kinase activation in the hamster suprachiasmatic nuclei
Authors: Pizzio Gastón A. , Hainich Ernesto C. , Plano Santiago A. , Ralph Martin R. , Golombek Diego A. 
Published: August 2005

AbstractCircadian rhythms are entrained by light and by several neurochemical stimuli. In hamsters housed in constant darkness, i.c.v. administration of nerve growth factor (NGF) at various times in their circadian cycle produced phase shifts of locomotor activity rhythms that were similar in direction and circadian timing to those produced by brief pulses of light. Moreover, the effect of NGF and light were not additive, indicating signalling points in common. These points include the immediate‐early gene c‐fos and ERK1/2, a component of the mitogen‐activated protein kinases (MAPK) family. NGF activates c‐FOS and ERK1/2‐MAPK in the suprachiasmatic nuclei, the site of a circadian clock in mammals, when administered during the subjective night but not during the day. The effect of NGF on ERK1/2 activation was not inhibited by the administration of MK‐801, a glutamate/NMDA receptor antagonist. These results suggest that NGF, acting through MAPK activation, plays a role in photic entrainment of the mammalian circadian clock.
Membrane‐associated guidance cues direct the innervation of forebrain and midbrain by dorsal raphe‐derived serotonergic axons
Authors: Petit Audrey , Kennedy Timothy E. , Bagnard Dominique , Doucet Guy 
Published: August 2005

AbstractUnlike many neurons that extend an axon precisely to a single target, individual dorsal raphe 5‐HT neurons project to multiple brain regions and their axon terminals often lack classical synaptic specializations. It is not known how 5‐HT axon collaterals select between multiple target fields, or even if 5‐HT axons require specific guidance cues to innervate their targets. Nor is it known how these axon collaterals are restrained within specific innervation target regions. To investigate this, we challenged explants of dorsal raphe with co‐explants, or cell membrane preparations of ventral midbrain, striatum or cerebral cortex. We provide evidence for membrane‐associated cues that promote 5‐HT axon growth into each of these three target regions. The axon growth‐promoting activity was heat‐, protease‐ and phosphatidylinositol‐phospholipase‐C (PI‐PLC)‐sensitive. Interestingly, 5‐HT axons specifically lost the ability to grow in heterotypic explants, or membrane carpets, following contact with ventral midbrain or striatal, but not cortical, explants or membranes. This inductive activity associated with striatal and ventral midbrain membranes was sensitive to both high salt extraction and PI‐PLC treatment. By contrast, the activity that inhibited 5‐HT axon growth onto heterotypic membranes was sensitive only to high salt extraction. These results provide evidence that a glycosylphosphatidylinositol (GPI)‐linked membrane protein promotes 5‐HT axon growth, and that short‐range membrane‐bound, as well as GPI‐linked, molecules contribute to the guidance of 5‐HT axon collaterals. These findings suggest that 5‐HT axon collaterals acquire a target‐induced growth‐inhibitory response to alternative targets, increasing their selectivity for the newly innervated field.
Spatial learning with unilateral and bilateral hippocampal networks
Authors: De Hoz Livia , Moser Edvard I. , Morris Richard G. M. 
Published: August 2005

AbstractThis study investigated the ability of animals to learn both reference memory and delayed matching‐to‐place variants of the watermaze after large lesions of the hippocampus that deliberately spared only small remnants of the structure. Groups were created that had differing blocks of residual tissue in the septal pole of the hippocampus (15% or 30% of total volume), located either unilaterally (30 or 50% on one side, 0% on the other) or bilaterally (30 + 30%). These groups were capable of learning the reference memory task, as indexed by normal spatially focused searching in a probe trial, but their rate of learning was slower than that of sham‐lesioned rats. An impairment in the rate of learning was also seen in the delayed match–to‐place task, where one‐trial memory was observed only at the shortest (5 s) intertrial interval in the lesioned groups with the largest sparing. In both tasks performance was proportional to the volume of hippocampus spared and independent of whether this was unilaterally or bilaterally located. The findings are compatible with distributed processing accounts of hippocampal memory storage.
Clinical utility of human glandular kallikrein 2 within a neural network for prostate cancer detection
Authors: Stephan Carsten , Jung Klaus , Soosaipillai Antoninus , Yousef George M. , Cammann Henning , Meyer Hellmuth , Xu Chuanliang , Diamandis Eleftherios P. 
Published: August 2005

OBJECTIVETo assess, using artificial neural networks (ANNs), human glandular kallikrein 2 (hK2), prostate‐specific antigen (PSA), and percentage free/total PSA (f/tPSA), for discriminating between prostate cancer and benign prostatic hyperplasia (BPH).MATERIAL AND METHODSSerum samples from 475 patients with prostate cancer (n = 347) or BPH (n = 128) within the PSA range of 1–20 ng/mL were analysed for tPSA, fPSA and hK2 (research assay, Toronto, Canada). Data were analysed in the ranges of 1–4, 2–4, 4–10, and 2–20 ng/mL tPSA. Back‐propagation ANN models with the variables PSA, f/tPSA, and hK2, hK2/fPSA and hK2/(f/tPSA) were constructed. The diagnostic validity was evaluated by receiver‐operating characteristic (ROC) curve analysis.RESULTSWhereas the median concentration of hK2 was not significantly different between patients with BPH or prostate cancer in any of the tPSA ranges, the f/tPSA, hK2/fPSA and hK2/(f/tPSA), and the hK2‐based ANN outputs were always significantly different between patients with prostate cancer or BPH. Using ROC curve comparison, all variables were significantly better than hK2 in all ranges. The hK2‐based ANN performed better than f/tPSA except in the 4–10 ng/mL tPSA range. At 90% and 95% sensitivity, the hK2‐based ANN was also significantly better than f/tPSA in the 1–4 ng/mL tPSA range. hK2/(f/tPSA) achieved equal results to the hK2‐based ANN except in the range 2–20 ng/mL tPSA.CONCLUSIONSThe hK2‐based ANN improves the outcome of f/tPSA but not hK2/(f/tPSA) in almost all analysed subgroups. When comparing the results at 90% and 95% sensitivity the hK2‐based ANN only performed significantly better than f/tPSA in the lowest tPSA range. Only in lower tPSA ranges do hK2‐based ANNs show an advantage for further improving prostate cancer detection.