bluuebunny/crossref_metadata_2025_split huggingface dataset:
Levobupivacaine caudal anesthesia in children: a randomized double‐blind comparison with bupivacaine
Authors: FRAWLEY GEOFF P. , DOWNIE SARAH , HUANG GRACE H. 
Published: April 2006

SummaryBackground:  Levobupivacaine is the pure S‐enantiomer of bupivacaine. Despite obvious benefits in the event of accidental intravascular injection there has been no studies demonstrating a clinically significant benefit to levobupivacaine over racemic bupivacaine for pediatric regional anesthesia. Given the similar pharmacokinetic profiles of both drugs the studies to date have been underpowered to demonstrate what is likely to be a small difference in clinical effectiveness. Our aim was to determine if there are significant differences in the clinical effectiveness of levobupivacaine compared with racemic bupivacaine for caudal anesthesia in children having lower abdominal surgery. A secondary aim was to determine if there are differences in the incidence of postoperative motor blockade between these agents.Methods:  Three hundred and ten children ranging in age from 1 month to 10.75 years in age having lower abdominal surgery were enrolled. Patients were randomized in a double blind manner to receive a caudal block with either 0.25% bupivacaine (n = 152) or 0.25% levobupivacaine (n = 155) to a total volume of 1 ml·kg−1. Motor blockade (modified Bromage scale) and postoperative pain or distress (FLACC behavioral scale for postoperative pain) were measured at predetermined time points during the subsequent 120 min.Results:  There were no significant adverse effects attributable to levobupivacaine. Success rates were defined as a lack of hemodynamic response to first surgical incision and low postoperative pain scores. At a mean duration of 5 min between block completion and first incision success for 1 ml·kg−1 of 0.25% bupivacaine was 91% and 94% for 0.25% levobupivacaine. Satisfactory postoperative analgesia was present in 98% of patients after bupivacaine caudal anesthesia and 97.5% for levobupivacaine. At 30 min following caudal anesthesia the incidence of postoperative motor block with racemic bupivacaine was 84% and decreased to 7% at 120 min. For levobupivacaine motor block at 30 min postcaudal was present in 85% and decreased to 11% at 120 min.Conclusions:  Levobupivacaine is an effective agent for caudal anesthesia in children at a recommended dose of 2.5 mg·kg−1. The rapidity of onset was suitable for establishment of surgical anesthesia and postoperative analgesia was achieved in greater than 97.5% of patients. It appears to be of equivalent potency to racemic bupivacaine in children requiring lower abdominal surgery.
Brain‐derived neurotrophic factor enhances glucose utilization in peripheral tissues of diabetic mice
Authors: Yamanaka M. , Tsuchida A. , Nakagawa T. , Nonomura T. , Ono‐Kishino M. , Sugaru E. , Noguchi H. , Taiji M. 
Published: April 2006

Aims: Repetitive subcutaneous or intracerebroventricular administration of brain‐derived neurotrophic factor (BDNF) ameliorates glucose metabolism and enhances energy expenditure in obese diabetic C57BL/KsJ‐db/dbmice. To explore the mechanism of action through which BDNF regulates glucose metabolism, we examined the effects of BDNF on glucose utilization and norepinephrine (NE) content in peripheral tissues of diabetic mice.Methods: [14C]2‐deoxyglucose ([14C]2‐DG) uptake into peripheral tissues was analysed after intravenous injection of [14C]2‐DG indb/dband normal C57BL/6 mice, and [14C]2‐DG uptake and NE content in peripheral tissues were analysed after subcutaneous administration of BDNF (20 mg/kg) to maledb/dband normal mice for 8 days.Results: [14C]2‐DG uptake in the diaphragm, heart, gastrocnemius, soleus and interscapular brown adipose tissue (BAT) ofdb/dbmice was significantly lower than in normal mice. Repetitive administration of BDNF todb/dbmice for 8 days enhanced [14C]2‐DG uptake in the diaphragm, heart, soleus, BAT and liver. The NE content in heart, skeletal muscle, interscapular BAT and liver ofdb/dbmice given BDNF was high compared withdb/dbmice given vehicle, whereas no significant change in NE content in peripheral tissues was observed in normal mice given BDNF and those given vehicle. BDNF did not affect [14C]2‐DG uptake or NE content in the white adipose tissue ofdb/dbmice.Conclusions: These data indicate that BDNF ameliorates glucose metabolism by enhancement of glucose utilization in muscle and BAT, with this effect caused by modulation of the central and peripheral nervous systems.
On the Bias of the Multiple-Imputation Variance Estimator in Survey Sampling
Authors: Kim Jae Kwang , Michael Brick J. , Fuller Wayne A. , Kalton Graham 
Published: April 2006

SummaryMultiple imputation is a method of estimating the variances of estimators that are constructed with some imputed data. We give an expression for the bias of the multiple-imputation variance estimator for data that are collected with a complex sample design. The bias may be sizable for certain estimators, such as domain means, when a large fraction of the values are imputed. A bias-adjusted variance estimator is suggested.
Testing for Order-Restricted Hypotheses in Longitudinal Data
Authors: Pilla Ramani S. , Qu Annie , Loader Catherine 
Published: April 2006

SummaryIn many biomedical studies, we are interested in comparing treatment effects with an inherent ordering. We propose a quadratic score test (QST) based on a quadratic inference function for detecting an order in treatment effects for correlated data. The quadratic inference function is similar to the negative of a log-likelihood, and it provides test statistics in the spirit of a χ2-test for testing nested hypotheses as well as for assessing the goodness of fit of model assumptions. Under the null hypothesis of no order restriction, it is shown that the QST statistic has a Wald-type asymptotic representation and that the asymptotic distribution of the QST statistic is a weighted χ2-distribution. Furthermore, an asymptotic distribution of the QST statistic under an arbitrary convex cone alternative is provided. The performance of the QST is investigated through Monte Carlo simulation experiments. Analysis of the polyposis data demonstrates that the QST outperforms the Wald test when data are highly correlated with a small sample size and there is a significant amount of missing data with a small number of clusters. The proposed test statistic accommodates both time-dependent and time-independent covariates in a model.
A New Approach to Cluster Analysis: the Clustering-Function-Based Method
Authors: Li Baibing 
Published: April 2006

SummaryThe purpose of the paper is to present a new statistical approach to hierarchical cluster analysis with n objects measured on p variables. Motivated by the model of multivariate analysis of variance and the method of maximum likelihood, a clustering problem is formulated as a least squares optimization problem, simultaneously solving for both an n-vector of unknown group membership of objects and a linear clustering function. This formulation is shown to be linked to linear regression analysis and Fisher linear discriminant analysis and includes principal component regression for tackling multicollinearity or rank deficiency, polynomial or B-splines regression for handling non-linearity and various variable selection methods to eliminate irrelevant variables from data analysis. Algorithmic issues are investigated by using sign eigenanalysis.
Regularized Semiparametric Model Identification with Application to Nuclear Magnetic Resonance Signal Quantification with Unknown Macromolecular Base-Line
Authors: Sima Diana M. , Van Huffel Sabine 
Published: April 2006

SummaryWe formulate and solve a semiparametric fitting problem with regularization constraints. The model that we focus on is composed of a parametric non-linear part and a nonparametric part that can be reconstructed via splines. Regularization is employed to impose a certain degree of smoothness on the nonparametric part. Semiparametric regression is presented as a generalization of non-linear regression, and all important differences that arise from the statistical and computational points of view are highlighted. We motivate the problem formulation with a biomedical signal processing application.
Fracture sealing and fluid overpressures in limestones of the Jabal Akhdar dome, Oman mountains
Authors: HILGERS C. , KIRSCHNER D. L. , BRETON J.‐P. , URAI J. L. 
Published: April 2006

AbstractFractures are important conduits for fluid flow in the Earth's crust. To better understand the spatial and temporal relations among fracturing, fracture sealing, and fluid flow, we have studied fractures, faults, and veins in a large dome (Jabal Akhdar) in the Oman mountains. Our work combines the results of meso‐ and microstructural analyses and stable isotope analyses. Seven generations of fractures and veins have been identified in the carbonate‐dominated dome. The earliest generations of veins developed during extension and subsidence of the Mesozoic basin. These veins formed in the inclined segments of bedding‐parallel stylolites and in extensional fractures that are perpendicular to bedding (#1 and #2, respectively). These extension‐related veins are truncated by bedding‐parallel veins (#4) that formed during top‐to‐north bedding‐parallel shear of both the northern and southern limbs of the dome. These veins are consistent with a change in stress regime and may be related to an earlier generation of strongly deformed pinch‐and‐swell veins (#3) that are exposed locally on the southern limb of the dome. Normal faults contain a set of en‐echelon tension gashes (#5) and veins emplaced in dilational jogs along the fault planes (#6). In the northern part of the dome, veins (#7) associated with thrusts post‐date the normal faults. Samples of veins and their host rocks were analyzed to provide information on fluid‐rock interaction in the dome and the scale(s) of fluid movement. Oxygen isotope values range from +16.2 to +29.3‰; carbon isotope values range from 0 to +3.6‰. The results of the structural and isotopic analyses are consistent with the early veins (#2–#5) having precipitated from overpressured fluid in a isotopically rock‐buffered system. During normal faulting (#5 and #6), a more open system allowed external fluid to infiltrate the dome at drained conditions and precipitate the youngest sets of veins (#6 and #7).
Development of a multibottle gas‐tight fluid sampler WHATS II for Japanese submersibles/ROVs
Authors: SAEGUSA S. , TSUNOGAI U. , NAKAGAWA F. , KANEKO S. 
Published: April 2006

AbstractThis paper summarizes the design and performance of our recently developed gas‐tight fluid sampler WHATS II, especially designed to collect seafloor venting gas‐rich fluid from submersibles/remotely operated vehicles (ROVs). It consists of four 150‐cm3 stainless steel sample cylinders, eight ball valves, a motor‐driven arm, a rail, a peristaltic pump, a control unit, and a flexible Teflon tube connected to a titanium inlet tube. All the parts have been designed to be used at undersea as deep as 4000 m. The motor‐driven arm on the rail can open and close each of the four cylinders. By pumping out distilled water that has filled an open cylinder and the dead spaces of the sampler, we can fill the cylinder with sample fluid. WHATS II can take a maximum of four different gas‐tight samples in a series. The whole operation can be arranged from the cabin, etc., of a submersible/ROV. Use of only one motor to operate eight valves makes the sampler small, light (21 kg in sea water), and easy to handle. In addition, the sampler is able to collect an almost uncontaminated gas‐tight sample from the seafloor. To date, the sampler has been used in more than 90 dive surveys by Japanese submersibles/ROVs, including Shinkai 2000, Shinkai 6500, and Hyper Dolphin, with a success rate of >90%.
JUSTIFIED COMMITMENTS? CONSIDERING RESOURCE ALLOCATION AND FAIRNESS IN MÉDECINS SANS FRONTIÈRES‐HOLLAND
Authors: FULLER LISA 
Published: April 2006

ABSTRACTNon‐governmental aid programs are an important source of health care for many people in the developing world. Despite the central role non‐governmental organizations (NGOs) play in the delivery of these vital services, for the most part they either lack formal systems of accountability to their recipients altogether, or have only very weak requirements in this regard. This is because most NGOs are both self‐mandating and self‐regulating. What is needed in terms of accountability is some means by which all the relevant stakeholders can have their interests represented and considered. An ideally accountable decision‐making process for NGOs should identify acceptable justifications and rule out unacceptable ones. Thus, the point of this paper is to evaluate three prominent types of justification given for decisions taken at the Dutch headquarters of Médecins sans Frontières. They are: population health justifications, mandate‐based justifications and advocacy‐based justifications. The central question at issue is whether these justifications are sufficiently robust to answer the concerns and objections that various stakeholders may have. I am particularly concerned with the legitimacy these justifications have in the eyes of project beneficiaries. I argue that special responsibilities to certain communities can arise out of long‐term engagement with them, but that this type of priority needs to be constrained such that it does not exclude other potential beneficiaries to an undesirable extent. Finally, I suggest several new institutional mechanisms that would enhance the overall equity of decisions and so would ultimately contribute to the legitimacy of the organization as a whole.
ETHICAL CONSIDERATIONS FOR CLINICAL PHOTOGRAPHY IN THE GLOBAL SOUTH
Authors: MACINTOSH TRACY 
Published: April 2006

ABSTRACTClinical photography is an important tool for teaching practitioners and field workers about the clinical manifestations of famine and undernutrition, particularly with respect to the Global South. Current international guidelines for clinical photography are not consistently applied or enforced, which has led to violations of privacy and rights, particularly for patients and victims of disaster in the Global South. Combining existing clinical photography guidelines from the North with ongoing clinical ethics debates in the South, this paper explores approaches to establishing photography guidelines throughout the world that will be sensitive to the privacy and dignities of all patients and victims of emergencies.
DESCRIPTIVE ETHICS: A QUALITATIVE STUDY OF LOCAL RESEARCH ETHICS COMMITTEES IN MEXICO
Authors: VALDEZ‐MARTINEZ EDITH , TURNBULL BERNARDO , GARDUÑO‐ESPINOSA JUAN , PORTER JOHN D.H. 
Published: April 2006

ABSTRACTObjective:  To describe how local research ethics committees (LRECs) consider and apply research ethics in the evaluation of biomedical research proposals.Design:  A qualitative study was conducted using purposeful sampling, focus groups and a grounded theory approach to generate data and to analyse the work of the LRECs.Setting and participants:  11 LRECs of the Mexican Institute of Social Security (IMSS).Results:  LRECs considered ethics to be implicit in all types of research, but that ethics reviews were only necessary for projects that included the direct participation of human beings. The LRECs appeared to understand the importance of consent, as in the completion of a consent form, but did not emphasise the importance of the process of acquiring ‘informed’ consent. The committees considered their main roles or functions to be: (a) to improve the methodological quality of research and to verify – if applicable – the ethical aspects; (b) to encourage personnel to undergo research training; (c) to follow‐up research to oversee the adherence to norms and compliance with a specified research timetable.Conclusions:  This study provides a valuable insight into how these LRECs understand the ethical review process. The emphasis of the committees was on rules, regulations, improving research methodology and research training, rather than a focus on efforts to protect the rights and well being of research subjects. The results encourage further normative and descriptive lines of investigation concerning education and the development of LRECs.
STRENGTHENING MEDICAL ETHICS BY STRATEGIC PLANNING IN THE ISLAMIC REPUBLIC OF IRAN
Authors: LARIJANI BAGHER , MALEK‐AFZALI HOSSEIN , ZAHEDI FARZANEH , MOTEVASELI ELAHEH 
Published: April 2006

ABSTRACTTo bring attention to medical ethics and to enhance the quality of health care in Iran, the Ministry of Health and Medical Education has introduced a strategic plan for medical ethics at a national level. This plan was developed through the organization and running of workshops in which experts addressed important areas related to medical ethics. They analysed strengths and weaknesses, opportunities and threats, and outlined a vision, a mission and specific goals and essential activities surrounding medical ethics. The current strategic plan has six main goals that will be reviewed in this paper. Some major activities that were carried out in recent years, and some future plans, will be also reviewed.
Altered growth characteristics of skin fibroblasts from wild‐derived mice, and genetic loci regulating fibroblast clone size
Authors: Yuan Rong , Flurkey Kevin , Van Aelst‐Bouma Renee , Zhang Weidong , King Benjamin , Austad Steve , Miller Richard A. , Harrison David E. 
Published: April 2006

SummaryMouse fibroblast senescence in vitro is an important model for the study of aging at cellular level. However, common laboratory mouse strains may have lost some important allele variations related to aging processes. In this study, growth in vitro of tail skin fibroblasts (TSFs) derived from a wild‐derived stock, Pohnpei (Pohn) mice, differed from growth of control C57BL/6 J (B6) TSFs. Pohn TSFs exhibited higher proliferative ability, fewer apoptotic cells, decreased expression of Cip1, smaller surface areas, fewer cells positive for senescence associated‐β‐galactosidase (SA‐β‐gal) and greater resistance to H2O2‐induced SA‐β‐gal staining and Cip1 expression. These data suggest that TSFs from Pohn mice resist cellular senescence‐like changes. Using large clone ratio (LCR) as the phenotype, a quantitative trait locus (QTL) analysis in a Pohn/B6 backcross population found four QTLs for LCR: Fcs1 on Chr 3 at 55 cm; Fcs2 on Chr X at 50 cm; Fcs3 on Chr 4 at 51 cm and Fcs4 on Chr 10 at 25 cm. Together, these four QTLs explain 26.1% of the variations in LCRs in the N2 population. These are the first QTLs reported that regulate fibroblast growth. Glutathione S transferase mu (GST‐mu) genes are overrepresented in the 95% confidence interval of Fcs1, and Pohn TSFs have higher H2O2‐induced GST‐mu 4, 5 and 7 mRNA levels than B6 TSFs. These enzymes may protect Pohn TSFs from oxidation.
Stiripentol, a Putative Antiepileptic Drug, Enhances the Duration of Opening of GABAA‐Receptor Channels
Authors: Quilichini Pascale P. , Chiron Catherine , Ben‐Ari Yehezkel , Gozlan Henri 
Published: April 2006

Summary: Purpose:Stiripentol (STP) is currently an efficient drug for add‐on therapy in infantile epilepsies because it improves the efficacy of antiepileptic drugs (AEDs) through its potent inhibition of liver cytochromes P450. In addition, STP directly reduces seizures in several animal models of epilepsy, suggesting that it might also have anticonvulsive effects of its own. However, its underlying mechanisms of action are unknown.Methods:We examined the interactions of STP with γ‐aminobutyric acid (GABA) transmission by using patch‐clamp methods in CA3 pyramidal neurons in the neonatal rat.Results:STP markedly increased miniature inhibitory postsynaptic current (mIPSC) decay‐time constant in a concentration‐dependent manner. The prolongation of mIPSC duration does not result from an interaction with GABA transporters because it persisted in the presence of GAT‐1 inhibitors (SKF‐89976A and NO‐711). An interaction with benzodiazepine or neurosteroid binding sites also was excluded because STP‐mediated increase of decay time was still observed when these sites were initially saturated (by clobazam, zolpidem, or pregnanolone) or blocked (by flumazenil or dehydroepiandrosterone sulfate), respectively. In contrast, saturating barbiturate sites with pentobarbital clearly occluded this effect of STP, suggesting that STP and barbiturates interact at the same locus. This was directly confirmed by using outside‐out patches, because STP increased the duration and not the frequency of opening of GABAAchannels.Conclusions:At clinically relevant concentrations, STP enhances central GABA transmission through a barbiturate‐like effect, suggesting that STP should possess an antiepileptic effect by itself.
The Opening Effect of Pregabalin on ATP‐Sensitive Potassium Channels in Differentiated Hippocampal Neuron–derived H19‐7 Cells
Authors: Huang Chin‐Wei , Huang Chao‐Ching , Wu Sheng‐Nan 
Published: April 2006

Summary: Purpose:Adenosine triphosphate (ATP)‐sensitive K+(KATP) channels can couple an intracellular metabolic state to an electrical activity, which is important in the control of neuronal excitability and seizure propagation. We investigated whether the newer antiepileptic drug, pregabalin (PGB), could exert effects on KATPchannels in differentiated hippocampal neuron–derived H19‐7 cells.Methods:The inside‐out configuration of the patch‐clamp technique was used to investigate KATPchannel activities in H19‐7 cells in the presence of PGB. Effects of various compounds known to alter KATPchannel activities were compared.Results:The activity of KATPchannels in these cells was characterized. The single‐channel conductance from a linear current–voltage relation was 78 ± 2 pS (n = 8) with a reversal potential of 63 ± 2 mV (n = 8), similar to that of KATPchannels reported in pancreatic β cells. 2,4‐Dinitrophenol activated channel activity, but the further addition of glucose (20 mM) or glibenclamide (30 μM) could offset these increments. PGB significantly opened these KATPchannel activities in a concentration‐dependent fashion with a median effective concentration (EC50) value of 18 μM. A significant increase was noted in the mean open lifetime of KATPchannels in the presence of PGB (1.71 ± 0.04 to 5.62 ± 0.04 ms).Conclusions:This study suggests that in differentiated hippocampal neuron–derived H19‐7 cells, the opening effect on KATPchannels could be one of the underlying mechanisms of PGB in the reduction of neuronal excitability.