bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Bispectral Index® and Narcotrend® Index to the Measurement of the Electroencephalographic Effects of Isoflurane with and without Burst Suppression
Authors: Kreuer Sascha , Bruhn Jörgen , Larsen Reinhard , Grundmann Ulrich , Shafer Steven L. , Wilhelm Wolfram 
Published: September 2004

Background
The Narcotrend monitor (MonitorTechnik, Bad Bramstedt, Germany) has recently been introduced as an intraoperative monitor of anesthetic state, based on a classification scheme originally developed for visual assessment of the electroencephalogram. The authors compared the performance of the Narcotrend index (software version 4.0) to the Bispectral Index (BIS, version XP; Aspect Medical Systems, Natick, MA) as electroencephalographic measures of isoflurane drug effect during general anesthesia.

Methods
The authors observed 15 adult patients scheduled to undergo radical prostatectomy with a combined epidural-isoflurane general anesthesia technique. At least 45 min after induction of general anesthesia, during a phase of constant surgical stimulation, end-tidal isoflurane concentrations were varied between 0.5 and 2.0 multiples of minimum alveolar concentration, and the BIS and the Narcotrend index were recorded. The prediction probability (PK) was calculated for the BIS and the Narcotrend index to predict isoflurane effect compartment concentration for each measure. The correlation analysis of the BIS and the Narcotrend index with the isoflurane effect compartment concentration was obtained by pharmacodynamic modeling based on two sigmoidal curves to account for the discontinuity in both indices with the onset of burst suppression.

Results
The prediction probabilities were indistinguishable (BIS PK = 0.72 +/- 0.07 (mean +/- SD); range, 0.61-0.84; Narcotrend index PK = 0.72 +/- 0.10; range, 0.51-0.87), as were the correlations between the electroencephalographic measures and isoflurane effect compartment concentrations (BIS R = 0.82 +/- 0.12; Narcotrend index R = 0.85 +/- 0.09). The pharmacodynamic models for the BIS and the Narcotrend index yielded nearly identical results.

Conclusions
The BIS and the Narcotrend index detected the electroencephalographic effects of isoflurane equally. Combining two fractional sigmoid Emax models adequately described the data before and after the onset of burst suppression.
Do Indomethacin and Propofol Cause Cerebral Ischemic Damage?
Authors: Rasmussen Mads , Østergaard Leif , Juul Niels , Gyldensted Carsten , Poulsen Peter V. , Cold Georg E. 
Published: September 2004

Background
Diffusion-weighted magnetic resonance imaging was used to determine whether indomethacin and propofol induce cerebral ischemic damage in patients undergoing craniotomy for cerebral tumors. As a secondary aim, the authors investigated whether low jugular bulb oxygen saturation values were associated with brain parenchymal damage as evaluated by diffusion-weighted imaging.

Methods
Nine patients subjected to craniotomy for supratentorial brain tumors in propofol-fentanyl anesthesia were studied. Magnetic resonance imaging including diffusion- and perfusion-weighted and structural sequences were performed (1) on the day before surgery, (2) before and (3) 20 min after administration of indomethacin (bolus of 0.2 mg/kg followed by infusion of 0.2 mg.kg.h) in the propofol-fentanyl-anesthetized patient, and (4) 2 days after surgery. Apparent diffusion coefficient maps were calculated. Jugular bulb oxygen saturation, arteriovenous oxygen difference, mean arterial blood pressure, and arterial oxygen and carbon dioxide tensions were measured simultaneously with the magnetic resonance examinations performed during anesthesia.

Results
No ischemic lesions were detected in the diffusion-weighted or apparent diffusion coefficient images. A nonsignificant decrease in jugular bulb oxygen saturation from 51% (range, 40-61%) to 43% (range, 37-63%) and increase in arteriovenous oxygen difference from 4.4 mm (range, 2.7-4.6 mm) to 4.7 mm (range, 2.9-5.2 mm) was observed after indomethacin administration.

Conclusion
Administration of indomethacin during propofol anesthesia is not associated with evidence of ischemic damage in patients with brain tumors, as evaluated by diffusion-weighted imaging.
Comparative Effects of Bupivacaine and Ropivacaine on Intracellular Calcium Transients and Tension in Ferret Ventricular Muscle
Authors: Mio Yasushi , Fukuda Norio , Kusakari Yoichiro , Amaki Yoshikiyo , Tanifuji Yasumasa , Kurihara Satoshi 
Published: September 2004

Background
Recent evidence suggests that ropivacaine exerts markedly less cardiotoxicity compared with bupivacaine; however, the mechanisms are not fully understood at the molecular level.

Methods
Isolated ferret ventricular papillary muscles were microinjected with the Ca-binding photoprotein aequorin, and intracellular Ca transients and tension were simultaneously measured during twitch in the absence and presence of bupivacaine or ropivacaine.

Results
Bupivacaine and ropivacaine (10, 30, and 100 microm) reduced peak systolic [Ca]i and tension in a concentration-dependent manner. The effects were significantly greater for bupivacaine, particularly on tension (approximately twofold). The percentage reduction of tension was linearly correlated with that of [Ca]i for both anesthetics, with the slope of the relationship being approximately equal to 1.0 for ropivacaine and approximately equal to 1.3 for bupivacaine (slope difference, P < 0.05), suggesting that the cardiodepressant effect of ropivacaine results predominantly from inhibition of Ca transients, whereas bupivacaine suppresses Ca transients and the reaction beyond Ca transients, i.e., myofibrillar activation, as well. BAY K 8644, a Ca channel opener, abolished the inhibitory effects of ropivacaine on Ca transients and tension, whereas BAY K 8644 only partially inhibited the effects of bupivacaine, particularly the effects on tension.

Conclusion
The cardiodepressant effect of bupivacaine is approximately twofold greater than that of ropivacaine. Bupivacaine suppresses Ca transients more markedly than does ropivacaine and reduces myofibrillar activation, which may at least in part underlie the greater inhibitory effect of bupivacaine on cardiac contractions. These results suggest that ropivacaine has a more favorable profile as a local anesthetic in the clinical settings.
Local Anesthetics Reduce Mortality and Protect against Renal and Hepatic Dysfunction in Murine Septic Peritonitis
Authors: Gallos George , Jones Dean R. , Nasr Samih H. , Emala Charles W. , Lee H Thomas 
Published: September 2004

Background
Mortality from sepsis frequently results from multiple organ injury and dysfunction. Cecal ligation and puncture is an established murine model of septic peritonitis that produces septic shock characterized by an initial hyperinflammatory response. In addition to their anesthetic properties, local anesthetics have been shown to attenuate inflammatory responses both in vivo and in vitro. In the current study, the ability of local anesthetic infusions to protect against sepsis-induced mortality, as well as renal and hepatic dysfunction after cecal ligation and puncture, was investigated.

Methods
C57BL/6 mice received mini-osmotic pumps containing saline (vehicle), 10% lidocaine, or 1% bupivacaine and were subjected to cecal ligation and puncture. Twenty-four hours after cecal ligation and puncture, renal and hepatic functions were assessed as well as markers of inflammation (proinflammatory cytokine protein and mRNA concentrations and myeloperoxidase activity). Renal apoptosis and 7-day survival was also assessed.

Results
Mice treated with lidocaine or bupivacaine infusion showed improved survival and had significantly lower plasma creatinine, aspartate aminotransferase, and alanine aminotransferase concentrations compared with mice receiving vehicle alone. Significant reduction in plasma tumor necrosis factor-alpha and keratinocyte-derived chemokine, as well as reductions in myeloperoxidase activity, intracellular adhesion molecule-1 protein expression, mRNA concentrations of proinflammatory markers, and apoptosis were observed in renal cortices from both local anesthetic groups.

Conclusions
The current data demonstrate that local anesthetic infusions confer a protective effect in mice from septic peritonitis by attenuating the hyperacute inflammatory response. This suppression resulted in improved mortality and less progression to acute kidney and liver injury and dysfunction.
Effect of Bupivacaine on the Isolated Rabbit Heart
Authors: Simon Lionel , Kariya Nobutaka , Edouard Alain , Benhamou Dan , Mazoit Jean-Xavier 
Published: September 2004

Background
Newborns and infants seem to be at greater risk of bupivacaine cardiotoxicity than adults do. Few experiments have studied the effects of local anesthetics on myocardium associated with developmental changes, and their conclusions are conflicting. The authors compared the effects of bupivacaine on an isolated heart preparation in newborn and adult rabbits.

Methods
The authors used a constant-flow, nonrecirculating Langendorff preparation paced atrially. Adult and newborn rabbit hearts were exposed to step-increasing concentrations of bupivacaine. For each concentration, heart rate was modified with pacing from 180 to 360 beats/min by increments of 30 beats/min. QRS complex duration (index of ventricular conduction) and the first derivative of left ventricular pressure (index of contractility) were measured. The two groups were compared using an Emax model.

Results
In newborn and adult rabbits, QRS complex duration increased with increasing bupivacaine concentration. No difference was observed between neonatal and adult hearts. Contractility decreased with increasing bupivacaine concentration. Newborn rabbits were approximately three times more sensitive than adult rabbits to the effects of bupivacaine. However, the concentration leading to 50% decrease in the first derivative of left ventricular pressure was much higher than the concentration leading to half maximum increase in QRS complex duration.

Conclusions
In conclusion, using a whole organ preparation, the authors demonstrated that bupivacaine induces similar impairment in ventricular conduction in newborn and adult rabbits. In particular, the tonic and the phasic blocks were of similar intensity in both groups. Conversely, the effect of bupivacaine on contractility was markedly higher in newborn rabbits than in adult rabbits. Also, contractility was less impaired than ventricular conduction in both groups.
Popliteal Sciatic Perineural Local Anesthetic Infusion
Authors: Ilfeld Brian M. , Thannikary Lisa J. , Morey Timothy E. , Vander Griend Robert A. , Enneking F Kayser 
Published: September 2004

Background
This randomized, double-blind study investigated the efficacy of continuous and patient-controlled ropivacaine infusion via a popliteal sciatic perineural catheter in ambulatory patients undergoing moderately painful orthopedic surgery of the foot or ankle.

Methods
Preoperatively, patients (n = 30) received a posterior popliteal sciatic perineural catheter and nerve block. Postoperatively, patients were discharged home with a portable infusion pump delivering 0.2% ropivacaine (500 ml) in one of three dosing regimens: the basal group (12-ml/h basal rate, 0.05-ml patient-controlled bolus dose), the basal-bolus group (8-ml/h basal rate, 4-ml bolus dose), or the bolus group (0.3-ml/h basal rate, 9.9-ml bolus dose).

Results
The bolus group experienced an increase in baseline pain, breakthrough pain incidence and intensity, and sleep disturbances compared with the other two groups (P < 0.05 for all comparisons). Compared with the basal-bolus group, the basal group experienced an increase in these outcome measures only after local anesthetic reservoir exhaustion, which occurred earlier than in the other two groups (P < 0.05 for all comparisons). Satisfaction scores did not differ among the three groups.

Conclusions
This study demonstrates that when providing analgesia with 0.2% ropivacaine via a popliteal sciatic perineural catheter after moderately painful surgery of the foot or ankle, a continuous infusion is required to optimize infusion benefits. Furthermore, adding patient-controlled bolus doses allows for a lower continuous basal rate and decreased local anesthetic consumption and thereby increases the duration of infusion benefits when in an ambulatory environment with a limited local anesthetic reservoir.
Contribution of Interaction between Nitric Oxide and Cyclooxygenases to the Production of Prostaglandins in Carrageenan-induced Inflammation
Authors: Toriyabe Masaki , Omote Keiichi , Kawamata Tomoyuki , Namiki Akiyoshi 
Published: September 2004

Background
Nitric oxide (NO) and prostaglandins (PGs) are crucial mediators contributing to generation of inflammatory responses and pain. This study was designed to investigate the effects of peripherally released NO on cyclooxygenase (COX) expression/activation and production of PGs in carrageenan-induced inflammation.

Methods
A microdialysis probe was implanted subcutaneously into the skin of hind paws of rats. The concentrations of NO metabolites, PGE2, and 6-keto-PGF1alpha (metabolite of PGI2) in the dialysate were measured. Carrageenan was injected into the plantar surface of the hind paw during perfusion of the dialysis catheter with modified Ringer's solution or N-monomethyl-L-arginine acetate. In addition, the effects of the selective COX-1 inhibitor SC-560 and the selective COX-2 inhibitor NS-398 on the production of NO, PGE2, and 6-keto-PGF1alpha were examined. Western blotting was performed to evaluate the expression of COX-1 and COX-2 in the skin at the site of the inflammation.

Results
Carrageenan injection resulted in increases in the concentrations of NO, PGE2, and PGI2, and these increases were completely suppressed by N-monomethyl-L-arginine acetate. SC-560 effectively inhibited the increase in PGE2 and PGI2 concentrations for the first 2 h, and NS-398 inhibited 3-6 h after carrageenan. Western blot analysis showed that the concentrations of both COX-1 and COX-2 in the skin increased after carrageenan. The up-regulation of COX-1 in the skin was observed 3 and 6 h after carrageenan and was not suppressed in the rats treated with N-monomethyl-L-arginine acetate. The up-regulation of COX-2 in the skin was also observed 3 and 6 h after carrageenan and was completely suppressed in the rats treated with N-monomethyl-L-arginine acetate.

Conclusion
The results of the current study suggest that NO activates COX-1 in the early phase of carrageenan and up-regulates COX-2 expression in the late phase in the skin, resulting in production of PGE2 and PGI2 at the site of inflammation, which would contribute to exacerbation of the inflammatory process.
Influence of the Type of Anesthesia Provider on Costs of Labor Analgesia to the Texas Medicaid Program
Authors: Abouleish Amr E. , Prough Donald S. , Vadhera Rakesh B. 
Published: September 2004

Background
The Texas Medicaid Program (Medicaid) defines billable time for labor analgesia as face-to-face time; therefore, anesthesia providers determine billed time. The authors' goal was to determine the influence of anesthesia providers on labor analgesia costs billed to Medicaid.

Methods
Under the Freedom of Information Act, Medicaid provided data on claims paid for 6 months in 2001 for labor analgesia administered during the course of a vaginal delivery. Claims were either time based (codes 00946 or 00955) or a flat fee (codes 26311 or 26319). Using modifiers, the authors grouped time-based claims as either anesthesiologist group or certified registered nurse anesthetist (CRNA) group. The cost to Medicaid was based on the 2001 fee schedule. The conversion factor was 18.21 USD per American Society of Anesthesiologists unit. The flat-fee reimbursement was 152.50 USD. CRNA services were paid at 85% of the fee schedule. Average time per time claim, percent of providers with more than 4 h of billed time, and cost per claim were determined for each group. Providers with more than 120 claims (> 20 claims/month) were considered high-volume.

Results
The database included 21,378 claims (anesthesiologist group: 12,698 claims from 219 providers; CRNA group: 8,680 claims from 117 providers). For time-based claims, the average time per case was significantly higher in the CRNA group (146 min) than in the anesthesiologist group (105 min). The CRNA group cost to Medicaid (225.11 USD) was 19% more per claim than the anesthesiologist group (189.26 USD). The difference in cost per claim was greater among high-volume providers--213.10 USD for the CRNA group versus 168.76 USD for the anesthesiologist group. If a flat-fee program were instituted using the average cost per claim for all groups (203.81 USD), the Texas Medicaid program would save more than 500,000 USD annually.

Conclusions
The costs of labor analgesia billed to Texas Medicaid were 19% to 26% less per patient when provided by anesthesiologists than by CRNAs, despite lower per-unit reimbursement of CRNAs.
Conservation laws of linear elasticity in stress formulations
Authors: Li Shaofan , Gupta Anurag , Markenscoff Xanthippi 
Published: September 2004

In this paper, we present new conservation laws of linear elasticity which have been discovered. These newly discovered conservation laws are expressed solely in terms of the Cauchy stress tensor, and they are genuine, non–trivial conservation laws that are intrinsically different from the displacement conservation laws previously known. They represent the variational symmetry conditions of combined Beltrami–Michell compatibility equations and the equilibrium equations.
To derive these conservation laws, Noether's theorem is extended to partial differential equations of a tensorial field with general boundary conditions. By applying the tensorial version of Noether's theorem to Pobedrja's stress formulation of three–dimensional elasticity, a class of new conservation laws in terms of stresses has been obtained.
The social context of well–being
Authors: Helliwell John F. , Putnam Robert D. 
Published: September 2004

Large samples of data from the World Values Survey, the US Benchmark Survey and a comparable Canadian survey are used to estimate equations designed to explore the social context of subjective evaluations of well–being, of happiness, and of health. Social capital, as measured by the strength of family, neighbourhood, religious and community ties, is found to support both physical health and subjective well–being.Our new evidence confirms that social capital is strongly linked to subjective well–being through many independent channels and in several different forms. Marriage and family, ties to friends and neighbours, workplace ties, civic engagement (both individually and collectively), trustworthiness and trust: all appear independently and robustly related to happiness and life satisfaction, both directly and through their impact on health.
History, Violence and Self‐Glorification in Afro‐Mexican corridos from Costa Chica de Guerrero
Authors: Ramsay Paulette A. 
Published: September 2004

‘The poetry, the culture itself, exists not in a dictionary but in the tradition of the spoken word. It is based as much on sound as it is on song. That is to say, the noise that it makes is part of the meaning, and if you ignore the noise (or what you would think of as noise, shall I say), then you lose part of the meaning.’(Braithwaite, 1984)‘Y no importa si es el calipso de Trinidad, o “dancehall” de Jamaica, o el choteo cubano o el chuchumbé mexicano, la expresión popular afro de toda la región ha tendido a aprovecharse del “relajamiento” como arma en socavar la estructura social dominante y a reconstruir un individuo más liberado.’1(Pereira, 1995)
Seasonal differences in leaf attributes in Australian tropical tree species: family and habitat comparisons
Authors: PRIOR L. D. , BOWMAN D. M. J. S. , EAMUS D. 
Published: September 2004

Summary

An individual evergreen leaf in the northern Australian savanna biome experiences seasonal extremes in rainfall, raising questions of whether there is a corresponding shift in the physiology of these leaves, and whether estimates of leaf function for the biome differ between wet and dry seasons.
A range of leaf attributes was measured for 21 tree species in four contrasting habitats during the wet season, and again during the dry season for the 14 species that retained leaves.
The 14 leaf‐retaining species showed decreases in assimilation rates, foliar saturated water content and chlorophyll content, and increases in leaf mass per area and leaf density between wet and dry seasons. Species means were strongly correlated between seasons for attributes other than assimilation and stomatal conductance.
Seasonal variation in CO2 assimilation rates was larger in non‐Myrtaceous species than in the leaf‐retaining Myrtaceous species that largely dominate the biome, and also varied considerably among the four habitats, which had different edaphic conditions. Assimilation per unit mass decreased between the wet and dry seasons by only 5% in the Melaleuca swamp and 17% in the Eucalyptus open forest, compared with 47% in the dry monsoon forest and 57% in the mixed woodland.
Biome means differed between seasons because wet‐season means included measurements of fully deciduous species which tended to have large, thin, nitrogen‐rich leaves.
Variations in leaf production and floral display of Anthurium schlechtendalii (Araceae) in response to herbivory and environment
Authors: CANTO A. , PARRA‐TABLA V. , GARCÍA‐FRANCO J. G. 
Published: September 2004

Summary

The study of the impact of herbivory on plant fitness and its relationship with environmental conditions is essential to an understanding of the ecological and evolutionary routes in different populations of the same plant species. This paper addresses the effects of herbivory and environment on growth (leaf production) and floral display (inflorescence production) in the tropical aroid Anthurium schlechtendalii ssp. schlechtendalii Kunth (Araceae).
Defoliation experiments were conducted in three natural A. schlechtendalii populations in Mexico: coastal sand dunes (Telchac); thorny dry forest (Dzemul); and medium‐height subhumid forest (Hobonil). Experiments were also conducted under common‐garden conditions using plants transplanted from the three populations.
Logistic regression models showed that herbivory did not affect growth negatively, but did affect floral display in A. schlechtendalii. The effect on floral display differed as a function of environment, damage intensity and season. When the plants experienced no resource limitation (common garden), herbivory inhibited inflorescence production in the first season (2001) and at the highest damage level (75%). When plants experienced heterogeneous resource conditions (field experiment), inflorescence production was inhibited in the second season (2002) at intermediate damage intensities.
Overall, A. schlechtendalii plants maintained growth regardless of damage intensity, but inflorescence production was reduced, indicating a trade‐off between growth and floral display due to herbivory. Results also suggested that plants were constrained in their response by the environmental history of their native site.