bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economic Analysis of Reprocessing Single-Use Medical Devices: A Systematic Literature Review
Authors: Jacobs Philip , Polisena Julie , Hailey David , Lafferty Susan 
Published: February 2008

Background.Although an increasing number of medical devices are labeled “for single use only,” cleaning and reuse of single-use medical devices continues, because of the economic incentive. We conducted a survey of the economic literature to obtain the current evidence available and to assess the costs and benefits of reusing single-use medical devices.Methods.A comprehensive literature search was carried out to identify articles that compared single use and reuse of single-use medical devices and that met specific scientific criteria, including evaluation of economic outcomes. Each selected article was independently reviewed by 2 reviewers to extract cost and clinical outcome data and to assess the quality of the study.Results.Nine published articles met the selection criteria. The savings were about 49% of the direct cost. These savings would be offset by adverse-event costs, but none were detected. However, quality of the studies was generally poor.Conclusions.There is little available evidence of quality in the published literature to assess the practice of reuse of single-use medical devices. Moreover, data on clinical outcomes are missing and, where available, cannot be attributed specifically to the reuse of single-use medical devices.
Epidural lidocaine‐bicarbonate‐adrenaline vs levobupivacaine for emergency Caesarean section: a randomised controlled trial*
Authors: Allam J. , Malhotra S. , Hemingway C. , Yentis S. M. 
Published: February 2008

SummaryEpidural mixtures containing lidocaine with or without additives are commonly used to convert epidural analgesia in labour to anaesthesia for emergency Caesarean section, but direct comparisons with alternative, single agents in this situation are few. In a prospective double‐blinded trial, we compared a freshly prepared lidocaine‐bicarbonate‐adrenaline mixture (final concentrations 1.8%, 0.76% and 1 : 200,000, respectively) with our standard agent, levobupivacaine 0.5%, for extending epidural blockade for emergency Caesarean section. Using a sequential analysis technique, with data analysed in blocks of 40, women receiving epidural analgesia in labour who required top‐up for Caesarean section were randomly assigned to receive 20 ml of epidural solution over 3 min. The first analysis (n = 40) indicated that the study should be stopped, as significant differences were found in our primary outcome data. Median (IQR [range]) times to reach a block to touch to T5 and cold to T4 were, respectively, 7 (6–9 [5–17]) min and 7 (5–8 [4–17]) min for lidocaine‐bicarbonate‐adrenaline, and 14 (10 −17 [9–31]) min and 11 (9–14 [6–30]) min for levobupivacaine (p = 0.00004 and 0.001, respectively). Pre‐ and intra‐operative supplementation/pain, maternal side‐effects and neonatal outcomes (excluding five women who underwent instrumental delivery) were similar between the groups. Intra‐operative maternal sedation (scored by the mother on a 10‐point scale) was greater with lidocaine‐bicarbonate‐adrenaline (4.5 (3–8 [1–9])) than with levobupivacaine (3 (1–4 [1–7])), but not significantly so (p = 0.07). We conclude that epidural lidocaine‐bicarbonate‐adrenaline halves the onset time when extending epidural analgesia for Caesarean section although there is a possibility of increased maternal sedation.
Coagulation and biochemical effects of balanced salt‐based high molecular weight vs saline‐based low molecular weight hydroxyethyl starch solutions during the anhepatic period of liver transplantation
Authors: Ahn H. J. , Yang M. , Gwak M. S. , Koo M. S. , Bang S. R. , Kim G. S. , Lee S. K. 
Published: February 2008

SummaryThe anhepatic period of liver transplantation is generally marked by a decrease in preload, and the infusion of hydroxyethyl starch (HES) solution is often an effective way to restore volume deficits in non‐anaemic patients. However, the infusion of even limited amounts of HES solution during the anhepatic period may result in a worsening coagulopathy. Moreover, lactate‐containing HES solution may cause some degree of biochemical derangements in compromised recipients. Therefore, we compared two different types of HES solutions: a balanced salt‐based high molecular weight HES solution (670/0.75; high MW group) and a saline‐based low molecular weight HES solution (130/0.4; low MW group) with respect to coagulation and biochemical profiles. First, in an in vitro study (n = 48), thromboelastography was performed to determine the effects of two HES solutions on coagulation after diluting (11%) the recipient's blood sample with each HES solution. Second, in an in vivo study, 500 ml of one of the two 6% HES solution was administered to 74 recipients (n = 37, each group) for 30 min after starting the anhepatic period. The coagulation profiles, including thromboelastography, and biochemical profiles were measured before and 30 min after the end of infusion. Less impairment in the thromboelastography profiles and aPTT was observed in the high MW group. A higher calcium concentration and less reduction in platelet count were noted in the high MW group, but lactate accumulation was greater. In conclusion, a balanced salt‐based high molecular weight HES solution is a more effective volume replacement during the anhepatic period of liver transplantation with respect to coagulation than a saline‐based low molecular weight HES solution, although lactate accumulation is a possible concern.
Apnoea in pregnancy: an investigation using physiological modelling
Authors: McClelland S. H. , Bogod D. G. , Hardman J. G. 
Published: February 2008

SummaryOxygen desaturation during apnoea following anaesthetic induction in obstetrics is hazardous for mother and baby. This study investigated apnoea during pregnancy using computer simulation. The Nottingham Physiology Simulator was configured to replicate normal pregnant physiology. Three pregnant and three non‐pregnant subjects were created, representing population variation according to published physiological values. They each commenced apnoea from four levels of pre‐oxygenation from none to 99% complete denitrogenation. During apnoea, the physiological changes of rapid sequence induction were simulated. We found reduced apnoea tolerance in pregnancy, the median [range] time taken to fall to Sao2 < 90% after 99% complete denitrogenation being 4 min 52 s [3:43–6:17] in the pregnant subjects, vs 7 min 25 s [5:49–9:42] in the non‐pregnant subjects. The time taken to fall from Sao2 90% to 40% was 35 s [32–45] in the pregnant vs 45 s [38–56] in the non‐pregnant subjects. Two minutes of pre‐oxygenation by tidal breathing provides approximately 3.5–6 min before desaturation to < 90%.
Tracheal pressures during open suctioning*
Authors: Vanner R. , Bick E. 
Published: February 2008

SummaryThe purpose of this bench‐top study was to determine the subatmospheric tracheal pressures that could be generated by different sizes of suction catheters when placed into the different sizes of tracheal tubes encountered in adult anaesthetic practice. Five sizes of suction catheter were studied from 8 to 16 Fr and five sizes of tracheal tubes from 5 to 9 mm internal diameter. We found that the larger suction catheters generated potentially dangerous levels of subatmospheric pressure. If the size of suction catheter was limited so that the ratio of the outside diameter of the suction catheter to the inside diameter of the tracheal tubes was 0.5 or less, tracheal pressures were not more than 2 mmHg subatmospheric. We were able to recommend sizes of suction catheter to use for each size of tracheal tube.
Population pharmacokinetic modelling for enterohepatic circulation of mycophenolic acid in healthy Chinese and the influence of polymorphisms in UGT1A9
Authors: Jiao Zheng , Ding Jun‐jie , Shen Jie , Liang Hui‐qi , Zhong Long‐jin , Wang Yi , Zhong Ming‐kang , Lu Wei‐yue 
Published: February 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Mycophenolic acid (MPA) undergoes enterohepatic circulation (EHC) in the body and several population models have been proposed to describe this process using sparse data.• Recent studies in Whites have found that polymorphism in UGT1A9 could partly explain the large interindividual variability associated with the pharmacokinetics of MPA. WHAT THIS STUDY ADDS • A new population pharmacokinetic model for EHC combining MPA and its main glucuronide metabolite (MPAG) simultaneously was established based on physiological aspects of biliary excretion using intensive sampling data.• Pharmacokinetic profiles of MPA and MPAG with the UGT1A9 polymorphism in healthy Chinese were characterized.AIMSTo establish a population pharmacokinetic model that describes enterohepatic circulation (EHC) of mycophenolic acid (MPA) based on physiological considerations and to investigate the influence of polymorphisms of UGT1A9 on the pharmacokinetics of MPA.METHODSPharmacokinetic data were obtained from two comparative bioavailability studies of oral mycophenolic mofetil formulations. Nonlinear mixed effects modelling was employed to develop an EHC model including both MPA and its main glucuronide metabolite (MPAG) simultaneously. Demographic characteristics and UGT1A9 polymorphisms were screened as covariates.RESULTSIn total, 590 MPA and 589 MPAG concentration–time points from 42 healthy male volunteers were employed in this study. The chain compartment model included an intestinal compartment, a gallbladder compartment, a central and a peripheral compartment for MPA and a central compartment for MPAG. The typical population clearance (CL/F) estimates with its relative standard error for MPA and MPAG were 10.2 l h−1 (5.7%) and 1.38 l h−1 (6.9%), respectively. The amount of MPA recycled in the body was estimated to be 29.1% of the total amount absorbed. Covariate analysis showed that body weight was positively correlated with CL/F of MPA, intercompartment CL/F of MPA and distribution volume of MPA peripheral compartment. Polymorphisms of UGT1A9 did not show any effect on the pharmacokinetics of MPA and MPAG. The model evaluation tests indicated that the proposed model can describe the pharmacokinetic profiles of MPA and MPAG in healthy Chinese subjects.CONCLUSIONSThe proposed model may provide a valuable approach for planning future pharmacokinetic–pharmacodynamic studies and for designing proper dosage regimens of MPA.
Transfer of chloroquine and desethylchloroquine across the placenta and into milk in Melanesian mothers
Authors: Law Irwin , Ilett Kenneth F. , Hackett L. Peter , Page‐Sharp Madhu , Baiwog Francesca , Gomorrai Servina , Mueller Ivo , Karunajeewa Harin A. , Davis Timothy M. E. 
Published: February 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • The literature on placental and milk transfer of chloroquine and its major bioactive metabolite desethylchloroquine is sparse and incomplete. WHAT THIS STUDY ADDS • We have provided data on the transplacental transfer of chloroquine and desethylchloroquine in Melanesian women (n = 19), measured transfer of these drugs into breast milk (n = 16) and estimated absolute and relative infant doses for the breastfed infant.• The data for desethylchloroquine are novel.• In all three areas we have significantly increased both quantity and quality of the available database.AIMSTo investigate the transfer of chloroquine and its major bioactive metabolite desethylchloroquine across the placenta and into breast milk.METHODSIn Papua New Guinea, chloroquine (CQ; 25 mg base kg−1) is recommended for prophylaxis of malaria during pregnancy, and at the Alexishafen Health Centre women are routinely prescribed CQ at the time of delivery. Fetal‐cord and maternal serum samples were collected at delivery (n = 19) and milk samples were collected from day 3 to day 17–21 after delivery (n = 16). CQ and its primary active metabolite desethylchloroquine (DECQ) were quantified by high‐performance liquid chromatography. For both CQ and DECQ cord/maternal ratios (C/M) were calculated to characterize placental transfer, and infant exposure via milk was estimated by standard methods.RESULTSThe median (interquartile range) C/M was 1.1 (0.9, 1.6) for CQ and 1.2 (0.5, 1.8) for DECQ. The average concentration in milk over the time of sampling was 167 μg l−1 (27, 340) for CQ and 54 μg l−1 (22, 106) for DECQ. Estimated absolute and relative infant doses were 34 μg kg−1 day−1 (7, 50) and 15 μg kg−1 day−1 (4, 26), and 2.3% (0.5, 3.6) and 1.0% (0.4, 2.0) for CQ and DECQ (as CQ equivalents), respectively.CONCLUSIONInfant exposure to CQ and DECQ during pregnancy will be similar to that in the maternal circulation, and dependent on maternal dose and frequency. The median CQ + DECQ relative infant dose of 3.2% (as CQ equivalents) was low, confirming that use of CQ during lactation is compatible with breastfeeding.
Assessment of antitussive efficacy of dextromethorphan in smoking related cough: objective vs. subjective measures
Authors: Ramsay James , Wright Caroline , Thompson Rachel , Hull David , Morice Alyn H. 
Published: February 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Dextromethorphan is widely used as a cough suppressant in over the counter medications.• Its efficacy in altering cough reflex sensitivity has been shown in healthy volunteers. In contrast evidence for an effect on clinically important cough is poor. WHAT THIS STUDY ADDS • A significant decrease in evoked cough was seen with dextromethorphan compared with placebo. However, both placebo and active treatment improved subjective data to a similar degree.• We doubt the validity of currently used objective tests in the investigation of antitussives.AIMSUsing an established model of smokers cough we measured the antitussive effects of dextromethorphan compared with placebo.METHODSThe study was a randomized, double‐blind placebo controlled, crossover comparison of 22 mg 0.8 ml−1 dextromethorphan delivered pregastrically with matched placebo. Objective and subjective measurements of cough were recorded. Subjective measures included a daily diary record of cough symptoms and the Leicester quality of life questionnaire. Cough frequency was recorded using a manual cough counter. The objective measure of cough reflex sensitivity was the citric acid, dose–response cough challenge.RESULTSDextromethorphan was significantly associated with an increase in the concentration of citric acid eliciting an average of two coughs/inhalation (C2) when compared with placebo, 1 h post dose by 0.49 mM (95% CI 0.05, 0.45, geometric mean 3.09) compared with placebo 0.24 mM (geometric mean 1.74) P < 0.05 and at 2 h 0.57 mM (95% CI 0.01, 0.43, geometric mean 3.75) compared with placebo 0.34 mM (geometric mean 2.19) P < 0.05). There was a highly significant improvement in the subjective data when compared with baseline. However, there was no significant difference between placebo and active treatment. No correlation was seen between cough sensitivity to citric acid and recorded cough counts or symptoms. When both subjective and objective data were compared with screening data there was evidence of a marked ‘placebo’ effect.CONCLUSIONSThe objective measure of cough sensitivity demonstrates dextromethorphan effectively diminishes the cough reflex sensitivity. However, subjective measures do not support this. Other studies support these findings, which may represent a profound sensitivity of the cough reflex to higher influences.
Mycorrhizal and rhizomorph dynamics in a loblolly pine forest during 5 years of free‐air‐CO2‐enrichment
Authors: PRITCHARD S. G. , STRAND A. E. , McCORMACK M. L. , DAVIS M. A. , OREN R. 
Published: February 2008

AbstractSoil fungi couple plant and ecosystem resource demands to pools of soil resources. Research on these organisms is needed to predict how rising atmospheric CO2 will influence forest ecosystem processes and soil carbon (C) sequestration potential. We examined the influence of free‐air‐CO2‐enrichment (FACE) on mycorrhizal and extraradical rhizomorph dynamics over a 5‐year period in a loblolly pine forest using minirhizotrons. Standing crop of mycorrhizal root tips varied greatly spatially and through time. Summed across all years, CO2 enrichment increased mycorrhizal root tip production by 194% in deep soil (15–30 cm) but did not influence mycorrhizal production in shallow soil (0–15 cm). Production and mortality of soil rhizomorph length was 27% and 25% greater in CO2‐enriched plots compared with controls over a 5‐year period beginning in January of 2000 and running through autumn 2004. Effects of atmospheric CO2 enrichment on longevity of mycorrhizal root tips and rhizomorphs varied with soil depth (mycorrhizae and rhizomorphs) and with diameter (rhizomorphs). For instance, survival of mycorrhizal tips was reduced in CO2‐enriched plots in deep soil (15–30 cm depth) but was increased in shallower soil (0–15 cm). Rhizomorph turnover was accelerated in shallow soil but effects on survivorship in deep soil varied according to diameter. A drought in 2002 coupled with loss of leaf area to an ice storm late in 2002 were followed by reductions in rhizomorph and mycorrhizal production, increases in mortality, and decreases in standing crop during 2003 and 2004. These effects tended to be more severe in CO2‐enriched plots. Positive effects of atmospheric CO2 enrichment on mycorrhizal fungi, primarily observed in deeper soil, are probably contributing to the prolonged stimulation of NPP by CO2 enrichment at the Duke FACE study site.
The sensitivity of annual grassland carbon cycling to the quantity and timing of rainfall
Authors: CHOU WENDY W. , SILVER WHENDEE L. , JACKSON RANDALL D. , THOMPSON ANDREW W. , ALLEN‐DIAZ BARBARA 
Published: February 2008

AbstractGlobal climate models predict significant changes to the rainfall regimes of the grassland biome, where C cycling is particularly sensitive to the amount and timing of precipitation. We explored the effects of both natural interannual rainfall variability and experimental rainfall additions on net C storage and loss in annual grasslands. Soil respiration and net primary productivity (NPP) were measured in treatment and control plots over four growing seasons (water years, or WYs) that varied in wet‐season length and the quantity of rainfall. In treatment plots, we increased total rainfall by 50% above ambient levels and simulated one early‐ and one late‐season storm. The early‐ and late‐season rain events significantly increased soil respiration for 2–4 weeks after wetting, while augmentation of wet‐season rainfall had no significant effect. Interannual variability in precipitation had large and significant effects on C cycling. We observed a significant positive relationship between annual rainfall and aboveground NPP across the study (P=0.01, r2=0.69). Changes in the seasonal timing of rainfall significantly affected soil respiration. Abundant rainfall late in the wet season in WY 2004, a year with average total rainfall, led to greater net ecosystem C losses due to a ∼50% increase in soil respiration relative to other years. Our results suggest that C cycling in annual grasslands will be less sensitive to changes in rainfall quantity and more affected by altered seasonal timing of rainfall, with a longer or later wet season resulting in significant C losses from annual grasslands.
Effect of soil water stress on soil respiration and its temperature sensitivity in an 18‐year‐old temperate Douglas‐fir stand
Authors: JASSAL RACHHPAL S. , BLACK T. ANDREW , NOVAK MICHAEL D. , GAUMONT‐GUAY DAVID , NESIC ZORAN 
Published: February 2008

AbstractWe analyzed 17 months (August 2005 to December 2006) of continuous measurements of soil CO2 efflux or soil respiration (RS) in an 18‐year‐old west‐coast temperate Douglas‐fir stand that experienced somewhat greater than normal summertime water deficit. For soil water content at the 4 cm depth (θ) > 0.11 m3 m−3 (corresponding to a soil water matric potential of −2 MPa), RS was positively correlated to soil temperature at the 2 cm depth (TS). Below this value of θ, however, RS was largely decoupled from TS, and evapotranspiration, ecosystem respiration and gross primary productivity (GPP) began to decrease, dropping to about half of their maximum values when θ reached 0.07 m3 m−3. Soil water deficit substantially reduced RS sensitivity to temperature resulting in a Q10 significantly < 2. The absolute temperature sensitivity of RS (i.e. dRS/dTS) increased with θ up to 0.15 m3 m−3, above which it slowly declined. The value of dRS/dTS was nearly 0 for θ < 0.08 m3 m−3, thereby confirming that RS was largely unaffected by temperature under soil water stress conditions. Despite the possible effects of seasonality of photosynthesis, root activity and litterfall on RS, the observed decrease in its temperature sensitivity at low θ was consistent with the reduction in substrate availability due to a decrease in (a) microbial mobility, and diffusion of substrates and extracellular enzymes, and (b) the fraction of substrate that can react at high TS, which is associated with low θ. We found that an exponential (van't Hoff type) model with Q10 and R10 dependent on only θ explained 92% of the variance in half‐hourly values of RS, including the period with soil water stress conditions. We hypothesize that relating Q10 and R10 to θ not only accounted for the effects of TS on RS and its temperature sensitivity but also accounted for the seasonality of biotic (photosynthesis, root activity, and litterfall) and abiotic (soil moisture and temperature) controls and their interactions.
Multiple invasions of Errantivirus in the genus Drosophila
Authors: Ludwig A. , Valente V. L. da S. , Loreto E. L. S. 
Published: February 2008

AbstractAiming to contribute to the knowledge of the evolutionary history of Errantivirus, a phylogenetic analysis of the env gene sequences of Errantivirus gypsy, gtwin, gypsy2, gypsy3, gypsy4 and gypsy6 was carried out in 33 Drosophilidae species. Most sequences were obtained from in silico searches in the Drosophila genomes. The complex evolutionary pattern reported by other authors for the gypsy retroelement was also observed in the present study, including vertical transmission, ancestral polymorphism, stochastic loss and horizontal transfer. Moreover, the elements gypsy2, gypsy3, gypsy4 and gypsy6 were shown to have followed an evolutionary model that is similar to gypsy. Fifteen new possible cases of horizontal transfer were suggested. The infectious potential of these elements may help elucidate the evolutionary scenario described in the present study.
Extraction of policosanols from hydrolysed rice bran wax by high‐intensity ultrasound
Authors: Liu Yuanfa , Yu Jun , Wang Xingguo 
Published: February 2008

SummaryThis study provided a detailed method for extraction and purification of policosanols from hydrolysed rice bran wax (RBW) by high‐intensity ultrasound (HIU), where the hydrolysis of RBW under HIU was focused. The optimised operating conditions for hydrolysis were as the following: 20 kHz, 100 W, 1:2 of wax to 4% sodium hydroxide (w:v) and 50 min at ambient temperature, under which the hydrolysis rate of 94.3% was obtained. Thereafter, policosanols were extracted and purified from the hydrolysed RBW. With the analysis by GC, it was shown that even‐numbered aliphatic alcohols were the major components of the policosanols, accounting for 95% or so, where triacontanol (C30) was the predominant component with 26.95%, followed by octacosanol (C28) with 17.04%, dotriacotanol (C32) with 16.01%, tetracosanol (C24) with 11.13%, hexacosanol with 10.90%; however, the odd‐numbered alcohols only accounted for about 5% and they were non‐acosanol (C29) with 2.92%, heptacosanol (C27) with 1.57% and pentacosanol (C25) with 0.65%.