Influence of socioeconomic factors on medically unnecessary ambulance calls

<p>Abstract</p> <p>Background</p> <p>Unnecessary ambulance use has become a socioeconomic problem in Japan. We investigated the possible relations between socioeconomic factors and medically unnecessary ambulance calls, and we estimated the incremental demand for unnecessary ambulance use produced by socioeconomic factors.</p> <p>Methods</p> <p>We conducted a self-administered questionnaire-based survey targeting residents of Yokohama, Japan. The questionnaire included questions pertaining to socioeconomic characteristics, dichotomous choice method questions pertaining to ambulance calls in hypothetical nonemergency situations, and questions on the city's emergency medical system. The probit model was used to analyze the data.</p> <p>Results</p> <p>A total of 2,029 out of 3,363 targeted recipients completed the questionnaire (response rate, 60.3%). Probit regression analyses showed that several demographic and socioeconomic factors influence the decision to call an ambulance. Male respondents were more apt than female respondents to state that they would call an ambulance in nonemergency situations (p < 0.05). Age was an important factor influencing the hypothetical decision to call an ambulance (p < 0.05); elderly persons were more apt than younger persons to state that they would call an ambulance. Possession of a car and hesitation to use an ambulance negatively influenced the hypothetical decision to call an ambulance (p < 0.05). Persons who do not have a car were more likely than those with a car to state that they would call an ambulance in unnecessary situations.</p> <p>Conclusion</p> <p>Results of the study suggest that several socioeconomic factors, i.e., age, gender, household income, and possession of a car, influence a person's decision to call an ambulance in nonemergency situations. Hesitation to use an ambulance and knowledge of the city's primary emergency medical center are likely to be important factors limiting ambulance overuse. It was estimated that unnecessary ambulance use is increased approximately 10% to 20% by socioeconomic factors.</p

Molecular mechanisms of extracellular adenine nucleotides-mediated inhibition of human Cd4+ T lymphocytes activation

We have previously reported that ATPγS, a slowly hydrolyzed analog of ATP, inhibits the activation of human CD4+ T lymphocytes by anti-CD3 and anti-CD28 mAb. In this report we have partially characterized the signaling mechanisms involved in this immunosuppressive effect. ATPγS had no inhibitory effect on CD4+ T-cell activation induced by PMA and anti-CD28, indicating that it acts proximally to the TCR. It had no effect on the calcium rise induced by CD3/CD28 stimulation, but inhibited the phosphorylation of three kinases, ERK2, p38 MAPK and PKB, that play a key role in the activation of T cells. The receptor involved in these actions remains unidentified

Sensory substitution information informs locomotor adjustments when walking through apertures

The study assessed the ability of the central nervous system (CNS) to use echoic information from sensory substitution devices (SSDs) to rotate the shoulders and safely pass through apertures of different width. Ten visually normal participants performed this task with full vision, or blindfolded using an SSD to obtain information regarding the width of an aperture created by two parallel panels. Two SSDs were tested. Participants passed through apertures of +0%, +18%, +35%, and +70% of measured body width. Kinematic indices recorded movement time, shoulder rotation, average walking velocity across the trial, peak walking velocities before crossing, after crossing and throughout a whole trial. Analyses showed participants used SSD information to regulate shoulder rotation, with greater rotation associated with narrower apertures. Rotations made using an SSD were greater compared to vision, movement times were longer, average walking velocity lower and peak velocities before crossing, after crossing and throughout the whole trial were smaller, suggesting greater caution. Collisions sometimes occurred using an SSD but not using vision, indicating that substituted information did not always result in accurate shoulder rotation judgements. No differences were found between the two SSDs. The data suggest that spatial information, provided by sensory substitution, allows the relative position of aperture panels to be internally represented, enabling the CNS to modify shoulder rotation according to aperture width. Increased buffer space indicated by greater rotations (up to approximately 35% for apertures of +18% of body width), suggests that spatial representations are not as accurate as offered by full vision

Activation of P2X7-mediated apoptosis Inhibits DMBA/TPA-induced formation of skin papillomas and cancer in mice

<p>Abstract</p> <p>Background</p> <p>The study tested the hypothesis that apoptosis can prevent and control growth of neoplastic cells. Previous studies in-vitro have shown that the pro-apoptotic P2X₇receptor regulates growth of epithelial cells. The specific objective of the present study was to understand to what degree the P2X₇system controls development and growth of skin cancer in vivo, and what cellular and molecular mechanisms are involved in the P2X₇action.</p> <p>Methods</p> <p>Skin neoplasias in mice (papillomas, followed by squamous spindle-cell carcinomas) were induced by local application of DMBA/TPA. Experiments in-vitro utilized cultured epidermal keratinocytes generated from wild-type or from P2X₇-null mice. Assays involved protein immunostaining and Western blots; mRNA real-time qPCR; and apoptosis (evaluated in situ by TUNEL and quantified in cultured keratinocytes as solubilized DNA or by ELISA). Changes in cytosolic calcium or in ethidium bromide influx (P2X₇pore formation) were determined by confocal laser microscopy.</p> <p>Results</p> <p>(a) Co-application on the skin of the P2X₇specific agonist BzATP inhibited formation of DMBA/TPA-induced skin papillomas and carcinomas. At the completion of study (week 28) the proportion of living animals with cancers in the DMBA/TPA group was 100% compared to 43% in the DMBA/TPA+BzATP group. (b) In the normal skin BzATP affected mainly P2X₇-receptor – expressing proliferating keratinocytes, where it augmented apoptosis without evoking inflammatory changes. (c) In BzATP-treated mice the degree of apoptosis was lesser in cancer than in normal or papilloma keratinocytes. (d) Levels of P2X₇receptor, protein and mRNA were 4–5 fold lower in cancer tissues than in normal mouse tissues. (e) In cultured mouse keratinocytes BzATP induced apoptosis, formation of pores in the plasma membrane, and facilitated prolonged calcium influx. (f) The BzATP-induced apoptosis, pore-formation and augmented calcium influx had similar dose-dependence for BzATP. (g) Pore formation and the augmented calcium influx were depended on the expression of the P2X₇receptor, while the BzATP-induced apoptosis depended on calcium influx. (h) The BzATP-induced apoptosis could be blocked by co-treatment with inhibitors of caspase-9 and caspase-3, but not of caspase-8.</p> <p>Conclusion</p> <p>(a) P2X₇-dependent apoptosis is an important mechanism that controls the development and progression of epidermal neoplasia in the mouse. (b) The P2X₇-dependent apoptosis is mediated by calcium influx via P2X₇pores, and involves the caspase-9 (mitochondrial) pathway. (c) The diminished pro-apoptotic effect of BzATP in mouse cancer keratinocytes is possibly the result of low expression of the P2X₇receptor. (d) Activation of P2X₇-dependent apoptosis, e.g. with BzATP could be a novel chemotherapeutic growth-preventive modality for papillomas and epithelial cancers in vivo.</p

The Toronto prehospital hypertonic resuscitation-head injury and multi organ dysfunction trial (TOPHR HIT) - Methods and data collection tools

<p>Abstract</p> <p>Background</p> <p>Clinical trials evaluating the use of hypertonic saline in the treatment of hypovolemia and head trauma suggest no survival superiority over normal saline; however subgroup analyses suggest there may be a reduction in the inflammatory response and multiorgan failure which may lead to better survival and enhanced neurocognitive function. We describe a feasibility study of randomizing head injured patients to hypertonic saline and dextran vs. normal saline administration in the out of hospital setting.</p> <p>Methods/Design</p> <p>This feasibility study employs a randomized, placebo-controlled design evaluating normal saline compared with a single dose of 250 ml of 7.5% hypertonic saline in 6% dextran 70 in the management of traumatic brain injuries. The primary feasibility endpoints of the trial were: 1) baseline survival rates for the treatment and control group to aid in the design of a definitive multicentre trial, 2) randomization compliance rate, 3) ease of protocol implementation in the out-of-hospital setting, and 4) adverse event rate of HSD infusion.</p> <p>The secondary objectives include measuring the effect of HSD in modulating the immuno-inflammatory response to severe head injury and its effect on modulating the release of neuro-biomarkers into serum; evaluating the role of serum neuro-biomarkers in predicting patient outcome and clinical response to HSD intervention; evaluating effects of HSD on brain atrophy post-injury and neurocognitive and neuropsychological outcomes.</p> <p>Discussion</p> <p>We anticipate three aspects of the trial will present challenges to trial success; ethical demands associated with a waiver of consent trial, challenging follow up and comprehensive accurate timely data collection of patient identifiers and clinical or laboratory values. In addition all the data collection tools had to be derived de novo as none existed in the literature.</p> <p>Trial registration number</p> <p>NCT00878631</p

Ancillary human health benefits of improved air quality resulting from climate change mitigation

<p>Abstract</p> <p>Background</p> <p>Greenhouse gas (GHG) mitigation policies can provide ancillary benefits in terms of short-term improvements in air quality and associated health benefits. Several studies have analyzed the ancillary impacts of GHG policies for a variety of locations, pollutants, and policies. In this paper we review the existing evidence on ancillary health benefits relating to air pollution from various GHG strategies and provide a framework for such analysis.</p> <p>Methods</p> <p>We evaluate techniques used in different stages of such research for estimation of: (1) changes in air pollutant concentrations; (2) avoided adverse health endpoints; and (3) economic valuation of health consequences. The limitations and merits of various methods are examined. Finally, we conclude with recommendations for ancillary benefits analysis and related research gaps in the relevant disciplines.</p> <p>Results</p> <p>We found that to date most assessments have focused their analysis more heavily on one aspect of the framework (e.g., economic analysis). While a wide range of methods was applied to various policies and regions, results from multiple studies provide strong evidence that the short-term public health and economic benefits of ancillary benefits related to GHG mitigation strategies are substantial. Further, results of these analyses are likely to be underestimates because there are a number of important unquantified health and economic endpoints.</p> <p>Conclusion</p> <p>Remaining challenges include integrating the understanding of the relative toxicity of particulate matter by components or sources, developing better estimates of public health and environmental impacts on selected sub-populations, and devising new methods for evaluating heretofore unquantified and non-monetized benefits.</p

Purinergic signalling and immune cells

This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Fine root chemistry and decomposition in model communities of north-temperate tree species show little response to elevated atmospheric CO 2 and varying soil resource availability

Rising atmospheric [CO 2 ] has the potential to alter soil carbon (C) cycling by increasing the content of recalcitrant constituents in plant litter, thereby decreasing rates of decomposition. Because fine root turnover constitutes a large fraction of annual NPP, changes in fine root decomposition are especially important. These responses will likely be affected by soil resource availability and the life history characteristics of the dominant tree species. We evaluated the effects of elevated atmospheric [CO 2 ] and soil resource availability on the production and chemistry, mycorrhizal colonization, and decomposition of fine roots in an early- and late-successional tree species that are economically and ecologically important in north temperate forests. Open-top chambers were used to expose young trembling aspen ( Populus tremuloides ) and sugar maple ( Acer saccharum ) trees to ambient (36 Pa) and elevated (56 Pa) atmospheric CO 2 . Soil resource availability was composed of two treatments that bracketed the range found in the Upper Lake States, USA. After 2.5 years of growth, sugar maple had greater fine root standing crop due to relatively greater allocation to fine roots (30% of total root biomass) relative to aspen (7% total root biomass). Relative to the low soil resources treatment, aspen fine root biomass increased 76% with increased soil resource availability, but only under elevated [CO 2 ]. Sugar maple fine root biomass increased 26% with increased soil resource availability (relative to the low soil resources treatment), and showed little response to elevated [CO 2 ]. Concentrations of N and soluble phenolics, and C/N ratio in roots were similar for the two species, but aspen had slightly higher lignin and lower condensed tannins contents compared to sugar maple. As predicted by source-sink models of carbon allocation, pooled constituents (C/N ratio, soluble phenolics) increased in response to increased relative carbon availability (elevated [CO 2 ]/low soil resource availability), however, biosynthetically distinct compounds (lignin, starch, condensed tannins) did not always respond as predicted. We found that mycorrhizal colonization of fine roots was not strongly affected by atmospheric [CO 2 ] or soil resource availability, as indicated by root ergosterol contents. Overall, absolute changes in root chemical composition in response to increases in C and soil resource availability were small and had no effect on soil fungal biomass or specific rates of fine root decomposition. We conclude that root contributions to soil carbon cycling will mainly be influenced by fine root production and turnover responses to rising atmospheric [CO 2 ], rather than changes in substrate chemistry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47710/1/442_2005_Article_191.pd