bluuebunny/crossref_metadata_2025 huggingface dataset:
Anoxic persistence of lumbar respiratory bursts and block of lumbar locomotion in newborn rat brainstem–spinal cords
Authors: Taccola Giuliano , Secchia Lucia , Ballanyi Klaus
Published: October 2007

The tolerance of breathing in neonates to oxygen depletion is reflected by persistence of inspiratory‐related motor output during sustained anoxia in newborn rat brainstem preparations. It is not known whether lumbar motor networks innervating expiratory abdominal muscles are, in contrast, inhibited by anoxia similar to locomotor networks in neonatal mouse lumbar cords. To test this, we recorded inspiratory‐related cervical/hypoglossal plus pre/postinspiratory lumbar/facial nerve activities and, sometimes simultaneously, locomotor rhythms in newborn rat brainstem–spinal cords. Chemical anoxia slowed 1 : 1‐coupled cervical and lumbar respiratory rhythms and induced cervical burst doublets associated with depressed preinspiratory and augmented postinspiratory lumbar activities. Similarly, anoxia evoked repetitive hypoglossal bursts and shifted facial activity toward augmented postinspiratory bursting in medullas without spinal cord. Selective lumbar anoxia augmented pre/postinspiratory lumbar bursting without slowing the rhythm. This suggests a medullary origin of both anoxic inspiratory double bursts and preinspiratory depression, but a mixed medullary/lumbar origin of boosted postinspiratory lumbar activity. Lumbar respiratory rhythm is likely to be generated by the parafacial respiratory group expiratory centre as indicated by lack of normoxic and anoxic bursting following brainstem transection between the facial motonucleus and the more caudal pre‐Bötzinger complex inspiratory centre. Opposed to sustained respiratory activities, anoxia reversibly abolished non‐rhythmic spinal discharges and electrically or chemically evoked lumbar locomotor activities, followed by pronounced postanoxic spinal hyperexcitability. We hypothesize that (i) the anoxia tolerance of neonatal breathing includes pFRG‐driven lumbar expiratory networks, (ii) the anoxic respiratory pattern transformation is due to disturbed inspiratory–expiratory centre interactions, and (iii) postanoxic lumbar hyperexcitability contributes to spasticity in cerebral palsy.
The relevance of non‐excitable cells for cardiac pacemaker function
Authors: Fahrenbach John P. , Mejia‐Alvarez Rafael , Banach Kathrin
Published: October 2007

Age‐dependent changes in the architecture of the sinus node comprise an increasing ratio between fibroblasts and cardiomyocytes. This change is discussed as a potential mechanism for sinus node disease. The goal of this study was to determine the mechanism through which non‐excitable cells influence the spontaneous activity of multicellular cardiomyocyte preparations. Cardiomyocyte monolayers (HL‐1 cells) or embryonic stem cell‐derived cardiomyocytes were used as two‐ and three‐dimensional cardiac pacemaker models. Spontaneous activity and conduction velocity (θ) were monitored by field potential measurements with microelectrode arrays (MEAs). The influence of fibroblasts (WT‐fibs) was determined in heterocellular cultures of different cardiomyocyte and fibroblast ratios. The relevance of heterocellular gap junctional coupling was evaluated by the use of fibroblasts deficient for the expression of Cx43 (Cx43−/−‐fibs). The beating frequency and θ of heterocellular cultures depended negatively on the fibroblast concentration. Interspersion of fibroblasts in cardiomyocyte monolayers increased the coefficient of the interbeat interval variability. Whereas Cx43−/−‐fibs decreased θ significantly less than WT‐fibs, their effect on the beating frequency and the beat‐to‐beat variability seemed largely independent of their ability to establish intercellular coupling. These results suggest that electrically integrated, non‐excitable cells modulate the excitability of cardiac pacemaker preparations by two distinct mechanisms, one dependent and the other independent of the heterocellular coupling established. Whereas heterocellular coupling enables the fibroblast to depolarize the cardiomyocytes or to act as a current sink, the mere physical separation of the cardiomyocytes by fibroblasts induces bradycardia through a reduction in frequency entrainment.
Voltage is a partial activator of rat thermosensitive TRP channels
Authors: Matta José A. , Ahern Gerard P.
Published: October 2007

TRPV1 and TRPM8 are sensory nerve ion channels activated by heating and cooling, respectively. A variety of physical and chemical stimuli activate these receptors in a synergistic manner but the underlying mechanisms are unclear. Both channels are voltage sensitive, and temperature and ligands modulate this voltage dependence. Thus, a voltage‐sensing mechanism has become an attractive model to explain the generalized gating of these and other thermo‐sensitive TRP channels. We show here using whole‐cell and single channel measurements that voltage produces only a partial activation of TRPV1 and TRPM8. At room temperature (20–25°C) membrane depolarization evokes responses that saturate at ∼50–60% of the maximum open probability. Furthermore, high concentrations of capsaicin (10 μm), resiniferatoxin (5 μm) and menthol (6 mm) reveal voltage‐independent gating. Similarly, other modes of TRPV1 regulation including heat, protein kinase C‐dependent phosphorylation, and protons enhance both the efficacy and sensitivity of voltage activation. In contrast, the TRPV1 antagonist capsazepine produces the opposite effects. These data can be explained by an allosteric model in which voltage, temperature, agonists and inverse agonists are independently coupled, either positively or negatively, to channel gating. Thus, voltage acts separately but in concert with other stimuli to regulate channel activation, and, therefore, a voltage‐sensitive mechanism is unlikely to represent a final, gating mechanism for these channels.
Unilateral suppression of pharyngeal motor cortex to repetitive transcranial magnetic stimulation reveals functional asymmetry in the hemispheric projections to human swallowing
Authors: Mistry Satish , Verin Eric , Singh Salil , Jefferson Samantha , Rothwell John C. , Thompson David G. , Hamdy Shaheen
Published: October 2007

Inhibitory patterns of repetitive transcranial magnetic stimulation (rTMS) were applied to pharyngeal motor cortex in order to establish its role in modulating swallowing activity and provide evidence for functionally relevant hemispheric asymmetry. Healthy volunteers underwent single pulse TMS before and for 60 min after differing intensities of 1 Hz rTMS (n= 9, 6 male, 3 female, mean age 34 ± 3 years) or theta burst stimulation (TBS) (n= 9, 6 male, 3 female, mean age 37 ± 4 years). Electromyographic responses recorded from pharynx and hand were used as a measure of cortico‐motor pathway excitability. Swallowing behaviour was then examined with a reaction time protocol, before and for up to 60 min after the most effective inhibitory protocol (1 Hz) applied to each hemisphere. Interventions were conducted on separate days and compared to sham using ANOVA. Only high intensity 1 Hz rTMS consistently suppressed pharyngeal motor cortex immediately and for up to 45 min (−34 ± 7%, P≤ 0.001). Adjacent hand and contralateral pharyngeal motor cortex showed no change in response (−15 ± 12%, P= 0.14 and 15 ± 12%, P= 0.45, respectively). When used to unilaterally disrupt each hemisphere, rTMS to pharyngeal motor cortex with the stronger responses altered normal (−12 ± 3%, P≤ 0.001) and fast (−9 ± 4%, P≤ 0.009) swallow times, not seen following rTMS to the contralateral cortex or after sham. Thus, suppression of pharyngeal motor cortex to rTMS is intensity and frequency dependent, which when applied to each hemisphere reveals functionally relevant asymmetry in the motor control of human swallowing.
During hypoxic exercise some vasoconstriction is needed to match O2delivery with O2demand at the microcirculatory level
Authors: Lundby Carsten , Boushel Robert , Robach Paul , Møller Kirsten , Saltin Bengt , Calbet José A. L.
Published: October 2007

To test the hypothesis that the increased sympathetic tonus elicited by chronic hypoxia is needed to match O2delivery with O2demand at the microvascular level eight male subjects were investigated at 4559 m altitude during maximal exercise with and without infusion of ATP (80 μg (kg body mass)−1min−1) into the right femoral artery. Compared to sea level peak leg vascular conductance was reduced by 39% at altitude. However, the infusion of ATP at altitude did not alter femoral vein blood flow (7.6 ± 1.0versus7.9 ± 1.0 l min−1) and femoral arterial oxygen delivery (1.2 ± 0.2versus1.3 ± 0.2 l min−1; control and ATP, respectively). Despite the fact that with ATP mean arterial blood pressure decreased (106.9 ± 14.2versus83.3 ± 16.0 mmHg,P< 0.05), peak cardiac output remained unchanged. Arterial oxygen extraction fraction was reduced from 85.9 ± 5.3 to 72.0 ± 10.2% (P< 0.05), and the corresponding venous O2content was increased from 25.5 ± 10.0 to 46.3 ± 18.5 ml l−1(control and ATP, respectively,P< 0.05). With ATP, leg arterial–venous O2difference was decreased (P< 0.05) from 139.3 ± 9.0 to 116.9 ± 8.4−1and legwas 20% lower compared to the control trial (1.1 ± 0.2versus0.9 ± 0.1 l min−1) (P= 0.069). In summary, at altitude, some degree of vasoconstriction is needed to match O2delivery with O2demand. Peak cardiac output at altitude is not limited by excessive mean arterial pressure. Exercising legis not limited by restricted vasodilatation in the altitude‐acclimatized human.
The Effects of Varying the Combustor-Turbine Gap
Authors: Cardwell N. D. , Sundaram N. , Thole K. A.
Published: October 2007

To protect hot turbine components, cooler air is bled from the high pressure section of the compressor and routed around the combustor where it is then injected through the turbine surfaces. Some of this high pressure air also leaks through the mating gaps formed between assembled turbine components where these components experience expansions and contractions as the turbine goes through operational cycles. This study presents endwall adiabatic effectiveness levels measured using a scaled up, two-passage turbine vane cascade. The focus of this study is evaluating the effects of thermal expansion and contraction for the combustor-turbine interface. Increasing the mass flow rate for the slot leakage between the combustor and turbine showed increased local adiabatic effectiveness levels while increasing the momentum flux ratio for the slot leakage dictated the coverage area for the cooling. With the mass flow held constant, decreasing the combustor-turbine interface width caused an increase in uniformity of coolant exiting the slot, particularly across the pressure side endwall surface. Increasing the width of the interface had the opposite effect thereby reducing coolant coverage on the endwall surface.
Influence of Aerodynamic Loading on Rotor-Stator Aerodynamic Interaction in a Two-Stage Low Pressure Research Turbine
Authors: Canepa Edward , Formosa Piergiorgio , Lengani Davide , Simoni Daniele , Ubaldi Marina , Zunino Pietro
Published: October 2007

The unsteady flow within a two-stage low-pressure research turbine equipped with high lift profiles has been investigated in detail for three different aerodynamic loading conditions. Experiments have been carried out at low speed. Velocity and turbulence intensity in the blade-to-blade plane at midspan have been measured by means of a crossed hot-wire probe, upstream and downstream of each blade row. The probe has been traversed circumferentially over 1.5 bladings pitch and the phase-locked data acquisition and ensemble average technique have been used to reconstruct the flow in space and time. The effects of multistage configuration have been identified and analyzed by considering the velocity components and turbulence intensity. Potential interaction from the downstream blading in relative motion, periodic wake perturbations from the upstream blading and preceding stage perturbations make the flow in the second stage extremely complex. Overall the flow downstream of rotors is perturbed in space by upstream and downstream stators, while flow downstream of stators is mostly perturbed in time by rotor effects. As expected, high lift profiles are significantly sensitive to incidence variation, with this effect further enhanced by the multistage cumulative interactions.
Interaction of Tip Clearance Flow and Three-Dimensional Separations in Axial Compressors
Authors: Gbadebo Semiu A. , Cumpsty Nicholas A. , Hynes Tom P.
Published: October 2007

This paper considers the interaction of tip clearance flow with three-dimensional (3D) separations in the corner region of a compressor cascade. Three-dimensional numerical computations were carried out using ten levels of tip clearance, ranging from zero to 2.18% of blade chord. The 3D separations on the blade suction surface were largely removed by the clearance flow for clearance about 0.58% of chord. For this cascade, experimental results at zero and 1.7% chord tip clearance were used to assess the validity of the numerical predictions. The removal mechanism was associated with the suppression of the leading edge horseshoe vortex and the interaction of tip clearance flow with the endwall boundary layer, which develops into a secondary flow as it is driven towards the blade suction surface. Such interaction leads to the formation of a new 3D separation line on the endwall. The separation line forms the base of a separated stream surface which rolls up into the clearance vortex.
Optimizing Truck Cab Layout for Driver Accommodation
Authors: Parkinson Matthew B. , Reed Matthew P. , Kokkolaras Michael , Papalambros Panos Y.
Published: October 2007

One important source of variability in the performance and success of products designed for use by people is the people themselves. In many cases, the acceptability of the design is affected more by the variability in the human users than by the variability attributable to the hardware from which the product is constructed. Designing for human variability as an inherent part of the product optimization process can improve the overall performance of the product. This paper presents a new approach to artifact design that applies population sampling and stochastic posture prediction in an optimization environment to achieve optimal designs that are robust to variability among users, including differences in age, physical size, strength, and cognitive capability. A case study involving the layout of the interior of a heavy truck cab is presented, focusing on simultaneous placement of the seat and steering-wheel adjustment ranges. Trade-offs between adjustability (an indicator of cost), driver accommodation, and safety are explored under this paradigm.
Unified Solving Jacobian∕Hessian Matrices of Some Parallel Manipulators With n SPS Active Legs and a Passive Constrained Leg
Authors: Lu Yi , Hu Bo
Published: October 2007

Some parallel manipulators with n spherical joint-prismatic joint-spherical joint (SPS)-type active legs and a passive constrained leg possess a larger capability of load bearing and are simple in structure of the active leg. In this paper, a unified and simple approach is proposed for solving Jacobian∕Hessian matrices and inverse∕forward velocity and acceleration of this type of parallel manipulators. First, a general parallel manipulator with n SPS-type active legs and one passive constrained leg in various possible serial structure is synthesized, and some formulae for solving the poses of constrained force∕torque and active∕constrained force matrix are derived. Second, the formulae for solving extension of active legs, the auxiliary velocity∕acceleration equation are derived. Third, the formulae for solving inverse∕forward velocity and acceleration and a Jacobian matrix without the first-order partial differentiation and a Hessian matrix without the second-order partial differentiation are derived. Finally, the procedure is applied to three parallel manipulators with four and five SPS-type active legs and one passive constrained leg in different serial structures and to illustrate.
Dynamic Modeling of the Milner Continuously Variable Transmission—The Basic Kinematics
Authors: Akehurst S. , Parker D. A. , Schaaf S.
Published: October 2007

In the Milner continuously variable transmission altering the axial separation between two moveable halves of the outer race set allows the radial position of the planet balls to vary, along with the contact positions on the inner and outer races and, hence, the transmission ratio changes. An inelastic analytical model implemented in SIMULINK is presented which allows the component positions, speeds, forces, and torques to be calculated. Use of a free body approach for individual components allows both individual and coupled component motions to be studied. Examples of the steady-state results and experimental verification are presented. Use of the model for dynamic investigations and to improve future versions of the transmission is discussed.
A Multiattribute Utility Theory-Based Method for Product Line Selection
Authors: Thevenot Henri J. , Steva Elizabeth D. , Okudan Gül E. , Simpson Timothy W.
Published: October 2007

This paper presents a method based on multiattribute utility theory (MAUT) that facilitates the selection of a product line. The method helps select the subset of products to manufacture based on criteria at the: (1) product level (e.g., manufacturing cost, profit); and (2) product family level (e.g., commonality, component reuse, variety, market coverage). An example involving a family of staplers is used to demonstrate the method and to provide a well-documented engineering application of MAUT in product family design.
Geometric Analysis and Synthesis of the Metamorphic Robotic Hand
Authors: Dai Jian S. , Wang Delun
Published: October 2007

This paper presents a novel robotic hand with a metamorphic palm which changes the traditional structure of a robotic hand. Based on this new hand structure, the paper investigates motion of the robotic fingers with respect to the palm by presenting finger operation planes and by revealing the relationship between finger motion and palm motion. The study presents the normals of the finger operation planes as a function of the input angles of the palm and uses these normals to relate finger motion to palm motion. This leads to the coaxial condition of the finger-palm relationship that is then converted to the coplanar condition of normals of all finger operation planes. The condition is then used to generate a coupler trajectory, and the iterative trajectory fitting and curve approximation are used for synthesis of palm links, leading to differential geometry based synthesis of angular lengths of the metamorphic palm.
Bacteroides: the Good, the Bad, and the Nitty-Gritty
Authors: Wexler Hannah M.
Published: October 2007

Summary:Bacteroides species are significant clinical pathogens and are found in most anaerobic infections, with an associated mortality of more than 19%. The bacteria maintain a complex and generally beneficial relationship with the host when retained in the gut, but when they escape this environment they can cause significant pathology, including bacteremia and abscess formation in multiple body sites. Genomic and proteomic analyses have vastly added to our understanding of the manner in which Bacteroides species adapt to, and thrive in, the human gut. A few examples are (i) complex systems to sense and adapt to nutrient availability, (ii) multiple pump systems to expel toxic substances, and (iii) the ability to influence the host immune system so that it controls other (competing) pathogens. B. fragilis, which accounts for only 0.5% of the human colonic flora, is the most commonly isolated anaerobic pathogen due, in part, to its potent virulence factors. Species of the genus Bacteroides have the most antibiotic resistance mechanisms and the highest resistance rates of all anaerobic pathogens. Clinically, Bacteroides species have exhibited increasing resistance to many antibiotics, including cefoxitin, clindamycin, metronidazole, carbapenems, and fluoroquinolones (e.g., gatifloxacin, levofloxacin, and moxifloxacin).
Fusarium
Infections in Immunocompromised Patients
Authors: Nucci Marcio , Anaissie Elias
Published: October 2007

Fusarium
species cause a broad spectrum of infections in humans, including superficial, locally invasive, and disseminated infections. The clinical form of fusariosis depends largely on the immune status of the host and the portal of entry, with superficial and localized disease occurring mostly in immunocompetent patients and invasive and disseminated disease affecting immunocompromised patients. Risk factors for severe fusariosis include prolonged neutropenia and T-cell immunodeficiency, especially in hematopoietic stem cell transplant recipients with severe graft-versus-host disease. The most frequent presentation of disseminated fusariosis is a combination of characteristic cutaneous lesions and positive blood cultures, with or without lung or sinus involvement. The prognosis is poor and is determined largely by degree of immunosuppression and extent of infection, with virtually a 100% death rate among persistently neutropenic patients with disseminated disease. These infections may be clinically suspected on the basis of a constellation of clinical and laboratory findings, which should lead to prompt therapy. Treatment options include the lipid formulations of amphotericin B, voriconazole, and posaconazole. Prevention of fusarial infection among high-risk patients should be considered.
Clinical Significance of Human Immunodeficiency Virus Type 1 Replication Fitness
Authors: Dykes Carrie , Demeter Lisa M.
Published: October 2007

The relative fitness of a variant, according to population genetics theory, is that variant's relative contribution to successive generations. Most drug-resistant human immunodeficiency virus type 1 (HIV-1) variants have reduced replication fitness, but at least some of these deficits can be compensated for by the accumulation of second-site mutations. HIV-1 replication fitness also appears to influence the likelihood of a drug-resistant mutant emerging during treatment failure and is postulated to influence clinical outcomes. A variety of assays are available to measure HIV-1 replication fitness in cell culture; however, there is no agreement regarding which assays best correlate with clinical outcomes. A major limitation is that there is no high-throughput assay that incorporates an internal reference strain as a control and utilizes intact virus isolates. Some retrospective studies have demonstrated statistically significant correlations between HIV-1 replication fitness and clinical outcomes in some patient populations. However, different studies disagree as to which clinical outcomes are most closely associated with fitness. This may be in part due to assay design, sample size limitations, and differences in patient populations. In addition, the strength of the correlations between fitness and clinical outcomes is modest, suggesting that, at present, it would be difficult to utilize these assays for clinical management.
Artificial playing surface increases the injury risk in pivoting indoor sports: a prospective one-season follow-up study in Finnish female floorball
Authors: Pasanen K , Parkkari J , Rossi L , Kannus P
Published: October 2007

Objectives:

To compare the injury risk in pivoting indoor sports between two different surfaces: artificial floors and wooden floors.

Methods:

Female players (n = 331) from 26 top-level Finnish floorball teams were followed for one competitive season (6 months). All traumatic game related time-loss injuries were recorded. Injury incidences were calculated as the number of injuries per 1000 game hours for both surfaces. Incidence rate ratios (IRRs) were obtained from Poisson regression models.

Results:

Over the competitive season, 62 traumatic injuries occurred during the games. The injury incidence per 1000 playing hours was 59.9 (95% CI 43.2 to 83.0) on artificial floors and 26.8 (95% CI 18.2 to 39.3) on wooden floors, the adjusted IRR being twofold higher (IRR = 2.1; 95% CI 1.2 to 3.5, p = 0.005) on artificial floors than wooden floors. The risk for non-contact injuries (adjusted IRR = 12.5; 95% CI 2.9 to 54.9, p = 0.001) and severe injuries (adjusted IRR = 3.3; 95% CI 0.9 to 10.9, p = 0.052) was especially high when playing on artificial floors.

Conclusions:

The study attested that the risk of traumatic injury in pivoting indoor sports is higher when playing on artificial floors than wooden floors. The higher shoe–surface friction on the former surface is likely to explain the higher injury risk.
Changes in technical regulations and drivers’ safety in top-class motor sports
Authors: Lippi G , Salvagno G L , Franchini M , Guidi G C
Published: October 2007

Motor racing is a dangerous sport and an inherently risky activity. The organisers of top-class motor sports championships, Formula One and MotoGP, have agreed on a set of regulations to reduce speed and improve safety over the last 10 years. These changes include limitations in weight, fuel and engine capacity. Nevertheless, there is evidence that most of the restrictions that have been introduced over the past 10 years have failed slow down vehicles, since the lap times have decreased almost linearly from 1995 to 2006 and drivers continue to die or to sustain serious injuries that keep them away from competition. Therefore, new and efficient measures should be adopted, such as lowering the cornering speed, having heavier and safer vehicles, having barriers surrounding the track to protect both spectators and competitors better, and having innovative clothing and protective devices to defend key anatomical structures while minimising the hindrance to the rider.
Cardiopulmonary exercise testing and its application
Authors: Albouaini Khaled , Egred Mohaned , Alahmar Albert , Wright David Justin
Published: October 2007

Cardiopulmonary exercise testing (CPET) has become an important clinical tool to evaluate exercise capacity and predict outcome in patients with heart failure and other cardiac conditions. It provides assessment of the integrative exercise responses involving the pulmonary, cardiovascular and skeletal muscle systems, which are not adequately reflected through the measurement of individual organ system function. CPET is being used increasingly in a wide spectrum of clinical applications for evaluation of undiagnosed exercise intolerance and for objective determination of functional capacity and impairment. This review focuses on the exercise physiology and physiological basis for functional exercise testing and discusses the methodology, indications, contraindications and interpretation of CPET in normal people and in patients with heart failure.
Suicide-associated comorbidity among US males and females: a multiple cause-of-death analysis
Authors: Rockett Ian R H , Wang Shuhui , Lian Yinjuan , Stack Steven
Published: October 2007

Objective:

To describe physical and mental comorbidity among male and female suicides in the US. This research replicates a seminal Australian study, which permits inference on comparative cause-of-death data quality.

Design and setting:

National cross-sectional study of suicides and unintentional injury decedents (comparison group) using Multiple Cause of Death (MCOD) public use files for 1999–2003.

Main outcome measures:

Prevalence of medical conditions; relative odds of suicide-associated comorbidity.

Results:

For 14% of male suicides and 19% of female suicides, comorbidity was shown on their death certificates. Respective prevalences for mental and physical comorbidity were 7.2% and 7.1% for males and 10.0% and 9.3% for females. Mean numbers of psychopathologies mentioned were virtually identical for male and female suicides (1.22 and 1.21) for whom comorbidity was registered. Mean mentions of physical disease were lower for male suicides: 1.64 vs 1.77. Multiple medical conditions were registered for 4% of male suicides and 6% of female suicides. Suicides manifested excess comorbidity for depression and mood disorders (adjusted odds ratio (AOR) = 34.6, 95% CI = 32.41 to 36.92), schizophrenia (AOR = 2.5, 95% CI = 2.16 to 2.88), and cancer (AOR = 2.1, 95% CI = 1.93 to 2.19), but unexpectedly no excess comorbidity for HIV.

Conclusions:

The US system of death certification appears to be less fastidious than the Australian system. Although comorbidity patterns were very similar, only half as much psychopathology was reported for US suicides as for Australian suicides. A questionable deficit of comorbid physical disease was also documented for US suicides. Findings have important implications for medical training, as well as for suicide surveillance, policy, and prevention.
Intracluster correlation coefficient in multicenter childhood trauma studies
Authors: Roudsari Bahman , Fowler Raymond , Nathens Avery
Published: October 2007

Objective:

To calculate the intracluster correlation coefficient (ICC) for emergency department (ED) shock rate, early trauma death (ie, death during the first 24 h after arrival at hospital), and in-hospital trauma death rate for multicenter childhood injuries.

Methods:

The National Trauma Data Bank (5th revision), the largest multicenter trauma registry in the US, was used. Data from 80 trauma centers were used to calculate the ICC for in-hospital trauma death rate. Thirty three states provided data for calculation of the ICC for ED shock and early trauma death rate.

Results:

From 2000 to 2004, 13% of the 952 242 patients in the National Trauma Data Bank were <15 years old. Approximately 17 000 of these children had injuries with an injury severity score >15, of whom 84% (14 095 subjects) were hospitalized at 80 level I or II trauma centers in 33 states. The ICCs for ED shock rate, early trauma death rate, and in-hospital death rate were 0.005 (95% CI 0.000 to 0.010), 0.014 (95% CI 0.004 to 0.024), and 0.023 (95% CI 0.013 to 0.033), respectively. These ICCs were calculated for boys and girls and also for blunt and penetrating injuries.

Conclusion:

Clustered childhood trauma studies that aim to compare different aspects of pre-hospital and hospital trauma care should incorporate these ICCs for sample calculation. When cluster randomized clinical trials are mounted, if sample sizes are calculated without adjustment for ICC, then the planned trial is likely to be seriously underpowered.
Demographic, socioeconomic, and attitudinal associations with children’s cycle-helmet use in the absence of legislation
Authors: Lang Iain A
Published: October 2007

The association of demographic, socioeconomic, and attitudinal factors with children’s cycle-helmet use was investigated using self-reported data from 9775 children aged 8–12 in England, where there are currently no legal requirements that cyclists (of any age) wear helmets. The results suggest that demographic factors, socioeconomic status, and attitudes influence whether children wear bicycle helmets but that attitudinal factors are most important.
Prevention of motor-vehicle deaths by changing vehicle factors
Authors: Robertson Leon S
Published: October 2007

Objective:

To estimate the effect of changing vehicle factors to reduce mortality in a comprehensive study.

Design/methods:

Odds of death in the United States during 2000–2005 were analyzed, involving specific makes and models of 1999–2005 model year cars, minivans, and sport utility vehicles using logistic regression after selection of factors to be included by examination of least-squares correlations of vehicle factors to maximize independence of predictors. Based on the regression coefficients, percentages of deaths preventable by changes in selected factors were calculated. Correlations of vehicle characteristics to environmental and behavioral risk factors were also examined to assess any potential confounding.

Results:

Deaths in the studied vehicles would have been 42% lower had all had electronic stability control (ESC) systems. Improved crashworthiness as measured by offset frontal and side crash tests would have produced an additional 28% reduction, and static stability improvement would have reduced the deaths 11%. Although weight–power that reduces fuel economy is associated with lower risk to drivers, it increases risk of deaths to pedestrians and bicyclists but has an overall minor effect compared to the other factors.

Conclusion:

A large majority of motor-vehicle-related fatalities could be avoided by universal adoption of the most effective technologies.
Child drowning deaths in Xiamen city and suburbs, People’s Republic of China, 2001–5
Authors: Fang Ya , Dai Long , Jaung Michael S , Chen Xiaoxuan , Yu Songlin , Xiang Huiyun
Published: October 2007

Background:

Risk-factor research and prevention programs targeting drowning deaths in children have been well developed in industrialized countries, but little research has been undertaken in developing countries where the majority of drowning deaths occur. We conducted an epidemiological study to describe the sociodemographic characteristics, drowning circumstances, and medical service in drowning deaths of children in Xiamen city and suburbs, People’s Republic of China.

Material and methods:

Drowning deaths in 1–14-year-old children between 2001 and 2005 were identified using death certificates. Parents of each case were interviewed face to face about the sociodemographics of the family and child, the drowning event, and medical care received. Mortalities were calculated using census data for urban and rural areas, and Poisson regression was used to evaluate confounding effects and interactions of several major risk factors for drowning death.

Results:

Of 67 drowning deaths identified, 52 (77.6%) were males. A higher proportion of deaths were in children aged 5–9 years (40.3%) and 10–14 years (40.3%). The drowning mortality per 100 000 population was 5.84 in rural areas and 0.75 in urban areas. Drowning events occurred most commonly during the summer months (56.7% from June to August), during the hours of 13:00–17:59 (62.7%), and in natural or man-made bodies of water (eg, ponds, ditches, construction sites, and wells). None of the children were proficient swimmers, the majority of drowning events (88.1%) occurred in the absence of adult supervision, and 86.6% children died at the scene without any medical care. Results from muiltivariable Poisson regression analysis indicated that 10–14-year-old boys were at the highest risk of drowning deaths in this area.

Discussion and conclusions:

Drowning deaths in children in Xiamen city and suburbs follow trends that are markedly different from patterns observed in other countries. Different prevention strategies may be required for preventing child drowning deaths in Xiamen and other developing regions.
Hypoxia-inducible factor-1α expression correlates with focal macrophage infiltration, angiogenesis and unfavourable prognosis in urothelial carcinoma
Authors: Chai C-Y , Chen W-T , Hung W-C , Kang W-Y , Huang Y-C , Su Y-C , Yang C-H
Published: October 2007

Background:

Hypoxia inducible factor (HIF)-1α is a critical regulatory protein of cellular response to hypoxia and is closely related to angiogenic process.

Aims:

To explore the potential role and the prognostic value of HIF-1α in urothelial carcinoma (UC).

Methods:

Clinicopathological and follow-up data on 99 UC cases were reviewed and immunostained for HIF-1α, CD68, vascular endothelial growth factor (VEGF) and CD34 antigen. Tumour-associated macrophage (TAM) counts and HIF-1α expression were compared with clinicopathologic characteristics, overall survival (OS) and disease-free survival rates (DFS).

Results:

High expression of HIF-1α was detected in 55 of 99 (55.6%) tumours. HIF-1α expression was correlated with tumour size, histological grade, tumour invasiveness and recurrence. VEGF and microvessel density (MVD) demonstrated their positive correlation with HIF-1α overexpression, supporting the correlation of HIF-1α up-regulation with tumour angiogenesis. Higher TAM infiltration was identified in high expression of HIF-1α cases rather than HIF-1α low expression cases (p = 0.002). Kaplan–Meier analysis found that HIF-1α overexpression and high TAM count was only associated with worse DFS (p = 0.009, p = 0.023) but was not associated with OS (p = 0.696, p = 0.141). Multivariate analyses indicated only tumour size (p = 0.038) to be an independently significant prognostic factor for OS, in addition, HIF-1α expression (p = 0.011), as well as histological grade (p = 0.038), and MVD (p = 0.004), to be independently significant prognostic factors for DFS.

Conclusions:

Our results indicate that HIF-1α is a key regulator of the angiogenic cascade. We show that HIF-1α is an independent prognostic factor for disease-free survival.
A detailed morphologic and immunohistochemical comparison of pre- and postmenopausal endometriosis
Authors: Cumiskey J , Whyte P , Kelehan P , Gibbons D
Published: October 2007

Background:

Endometriosis depends on oestrogenic stimulation for its continued growth, accounting for its prevalence during reproductive years. There is doubt among clinicians regarding its existence in postmenopausal women in the absence of exogenous or endogenous sex hormones. We postulated that endometriosis occurring in postmenopausal women would show a different morphologic and immunohistochemical profile to the disease occurring in premenopausal women.

Methods:

We reviewed the most recent 100 cases of endometriosis in our department plus all cases occurring in women aged ⩾50 dating back to 1999. Cases were divided into <50 (n = 91), 50–59 (8) and ⩾60 (6), and analysed for extent of disease, proportions of epithelium and stroma, and amount of haemorrhage. Immunohistochemistry for oestrogen receptor (OR), progesterone receptor (PR) and CD10 was performed and analysed on all cases aged ⩾50 and on controls <50.

Results:

There was statistically less disease in older women when cases occurring in the cervix and in scars were excluded (p = 0.0191). There was no statistical difference in the proportions of epithelium or stroma, but there was a statistical difference in the amount of haemorrhage (p = 0.0154) with older women showing less haemorrhage. There was no significant difference in immunohistochemical profile.

Conclusions:

Endometriosis does occur in postmenopausal women but is less common, is present in smaller volumes, and is less active. It has the same immunohistochemical profile as the disease occurring in premenopausal women and we infer from this that it has the potential to reactivate given the appropriate stimulation.
Light and electron microscopy characteristics of the muscle of patients withSURF1gene mutations associated with Leigh disease
Authors: Pronicki M , Matyja E , Piekutowska-Abramczuk D , Szymańska-Dębińska T , Karkucińska-Więckowska A , Karczmarewicz E , Grajkowska W , Kmieć T , Popowska E , Sykut-Cegielska J
Published: October 2007

Aims:

Leigh syndrome (LS) is characterised by almost identical brain changes despite considerable causal heterogeneity.SURF1gene mutations are among the most frequent causes of LS. Although deficiency of cytochromecoxidase (COX) is a typical feature of the muscle in SURF1-deficient LS, other abnormalities have been rarely described. The aim of the present work is to assess the skeletal muscle morphology coexisting withSURF1mutations from our own research and in the literature.

Methods:

Muscle samples from 21 patients who fulfilled the criteria of LS andSURF1mutations (14 homozygotes and 7 heterozygotes of c.841delCT) were examined by light and electron microscopy.

Results:

Diffuse decreased activity or total deficit of COX was revealed histochemically in all examined muscles. No ragged red fibres (RRFs) were seen. Lipid accumulation and fibre size variability were found in 14 and 9 specimens, respectively. Ultrastructural assessment showed several mitochondrial abnormalities, lipid deposits, myofibrillar disorganisation and other minor changes. In five cases no ultrastructural changes were found. Apart from slight correlation between lipid accumulation shown by histochemical and ultrastructural techniques, no other correlations were revealed between parameters investigated, especially between severity of morphological changes and the patient’s age at the biopsy.

Conclusion:

Histological and histochemical features of muscle of genetically homogenous SURF1-deficient LS were reproducible in detection of COX deficit. Minor muscle changes were not commonly present. Also, ultrastructural abnormalities were not a consistent feature. It should be emphasised that SURF1-deficient muscle assessed in the light and electron microscopy panel may be interpreted as normal if COX staining is not employed.
Effect of storage and postage on recovery and quantitation of bacteria in sputum samples
Authors: Pye A , Hill S L , Bharadwa P , Stockley R A
Published: October 2007

Aims:

The aims of the study were to compare bacterial recovery following storage of sputum samples at 20°C room temperature and 4°C (refrigerated) for 24 h, and to determine the effect of postage on viable bacterial numbers.

Methods:

A total of 38 individual sputum samples from clinically stable patients with bronchiectasis were split into three equal aliquots and quantitative bacterial culture was performed (i) immediately, (ii) following storage at 4°C for 24 h or (iii) following storage at 20°C for 24 h. A further 42 sputum samples were split into two equal aliquots and quantitative bacterial culture was performed either immediately or following postage back to the laboratory by first-class mail from an outside location.

Results:

The predominant organism could still be recovered following storage at 4°C and 20°C, but viable numbers were significantly reduced following storage at 4°C (p<0.004) by at least an order of magnitude (10-fold) in 24% of samples stored at 4°C compared with only 8% stored at 20°C. Posting samples back to the laboratory did not affect the recovery of bacterial species and there was no difference in viable numbers isolated.

Conclusions:

The results suggest that storage at room temperature is preferable to refrigeration as it retains the species isolated and the viable number. The data also confirm that sputum samples can be posted to the laboratory from patients in the community without affecting qualitative or quantitative results.
Coercion and pressure in psychiatry: lessons from Ulysses
Authors: Widdershoven Guy , Berghmans Ron
Published: October 2007

Coercion and pressure in mental healthcare raise moral questions. This article focuses on moral questions raised by the everyday practice of pressure and coercion in the care for the mentally ill. In view of an example from literature—the story of Ulysses and the Sirens—several ethical issues surrounding this practice of care are discussed. Care giver and patient should be able to express feelings such as frustration, fear and powerlessness, and attention must be paid to those feelings. In order to be able to evaluate the intervention, one has to be aware of the variety of goals the intervention can aim at. One also has to be aware of the variety of methods of intervention, each with its own benefits and drawbacks. Finally, an intervention requires a context of care and responsibility, along with good communication and fair treatment before, during and after the use of coercion and pressure.
Relevance and limits of the principle of “equivalence of care” in prison medicine
Authors: Niveau Gérard
Published: October 2007

The principle of “equivalence of care” in prison medicine is a principle by which prison health services are obliged to provide prisoners with care of a quality equivalent to that provided for the general public in the same country. It is cited in numerous national and international directives and recommendations.

The principle of equivalence is extremely relevant from the point of view of normative ethics but requires adaptation from the point of view of applied ethics. From a clinical point of view, the principle of equivalence is often insufficient to take account of the adaptations necessary for the organization of care in a correctional setting. The principle of equivalence is cost-effective in general, but has to be overstepped to ensure the humane management of certain special cases.
Interacting effects of particulate pollution and cold temperature on cardiorespiratory mortality in Scotland
Authors: Carder M , McNamee R , Beverland I , Elton R , Van Tongeren M , Cohen G R , Boyd J , MacNee W , Agius R M
Published: October 2007

Objectives:

To determine whether the effect of black smoke on cardiorespiratory mortality is modified by cold temperatures.

Methods:

Poisson regression models were used to investigate the relationship between lagged black smoke concentration and daily mortality, and whether the effect of black smoke on mortality was modified by cold temperature for three Scottish cities from January 1981 to December 2001.

Main results:

For all-cause respiratory and non-cardiorespiratory mortality, there was a significant association between mortality and lagged black smoke concentration. Generally the maximum black smoke effect occurred at lag 0, although these estimates were not statistically significant. A 10 μgm−3increase in the daily mean black smoke concentration on any given day was associated with a 1.68% (95% CI 0.72 to 2.65) increase in all-cause mortality and a 0.43% (95% CI −0.97 to 1.86), 5.36% (95% CI 2.93 to 7.84) and 2.13% (95% CI 0.82 to 3.47) increase in cardiovascular, respiratory and non-cardiorespiratory mortality, respectively, over the ensuing 30-day period. The effect of black smoke on mortality did not vary significantly between seasons (cool and warm periods). For all-cause, cardiovascular and non-cardiorespiratory mortality the inclusion of interaction terms did not improve the models, although for all-cause and non-cardiorespiratory mortality there was a suggestion for interaction between temperature and recent black smoke exposure.

Conclusions:

The results of this study suggested a greater effect of black smoke on mortality at low temperatures. Since extremes of cold and particulate pollution may coexist, for example during temperature inversion, these results may have important public health implications.
Adjustment for temporal confounders in a reanalysis of a case–control study of beryllium and lung cancer
Authors: Schubauer-Berigan M K , Deddens J A , Steenland K , Sanderson W T , Petersen M R
Published: October 2007

Objectives:

To evaluate potential confounding of the association between beryllium and lung cancer in a reanalysis of data from a published case–control study of workers at a beryllium processing facility.

Methods:

The association of cumulative and average beryllium exposure with lung cancer among 142 cases and five age-match controls per case was reanalysed using conditional logistic regression. Adjustment was made independently for potential confounders of hire age and birth year. Alternative adjustments to avoid taking the logarithm of zero were explored.

Results:

Adjustment for either birth cohort or hire age (two highly correlated factors) attenuated lung cancer risk associated with cumulative exposure; however, lung cancer risk was significantly associated with average exposure using a 10-year lag following adjustment. Stratification of analyses by birth cohort found greater lung cancer risk from cumulative and average exposure for workers born before 1900 than for workers born later. The magnitude of the association between lung cancer and average exposure was not reduced by modifying the method used to take the log of exposure.

Conclusion:

In this reanalysis, average, but not cumulative, beryllium exposure was related to lung cancer risk after adjustment for birth cohort. Confounding by birth cohort is likely related to differences in smoking patterns for workers born before 1900 and the tendency for workers hired during the World War II era to have been older at hire.