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1.
    

Background

The risks and benefits of infection prophylaxis are uncertain in children with cancer and thus, preferences should be considered in decision making. The purpose of this report was to describe the attitudes of parents, children and healthcare professionals to infection prophylaxis in pediatric oncology.

Methods

The study was completed in three phases: 1) An initial qualitative pilot to identify the main attributes influencing the decision to use infection prophylaxis, which were then incorporated into a discrete choice experiment; 2) A think aloud during the discrete choice experiment in which preferences for infection prophylaxis were elicited quantitatively; and 3) In-depth follow up interviews. Interviews were recorded verbatim and analyzed using an iterative, thematic analysis. Final themes were selected using a consensus approach.

Results

A total of 35 parents, 22 children and 28 healthcare professionals participated. All three groups suggested that the most important factor influencing their decision making was the effect of prophylaxis on reducing the chance of death. Themes of importance to the three groups included antimicrobial resistance, side effects of medications, the financial impact of outpatient prophylaxis and the route and schedule of administration.

Conclusion

Effect of prophylaxis on risk of death was a key factor in decision making. Other identified factors were antimicrobial resistance, side effects of medication, financial impact and administration details. Better understanding of factors driving decision making for infection prophylaxis will help facilitate future implementation of prophylactic regiments.  相似文献   
2.
Schlemm’s canal (SC) endothelial cells are likely important in the physiology and pathophysiology of the aqueous drainage system of the eye, particularly in glaucoma. The mechanical stiffness of these cells determines, in part, the extent to which they can support a pressure gradient and thus can be used to place limits on the flow resistance that this layer can generate in the eye. However, little is known about the biomechanical properties of SC endothelial cells. Our goal in this study was to estimate the effective Young’s modulus of elasticity of normal SC cells. To do so, we combined magnetic pulling cytometry of isolated cultured human SC cells with finite element modeling of the mechanical response of the cell to traction forces applied by adherent beads. Preliminary work showed that the immersion angles of beads attached to the SC cells had a major influence on bead response; therefore, we also measured bead immersion angle by confocal microscopy, using an empirical technique to correct for axial distortion of the confocal images. Our results showed that the upper bound for the effective Young’s modulus of elasticity of the cultured SC cells examined in this study, in central, non-nuclear regions, ranged between 1,007 and 3,053 Pa, which is similar to, although somewhat larger than values that have been measured for other endothelial cell types. We compared these values to estimates of the modulus of primate SC cells in vivo, based on images of these cells under pressure loading, and found good agreement at low intraocular pressure (8–15 mm Hg). However, increasing intraocular pressure (22–30 mm Hg) appeared to cause a significant increase in the modulus of these cells. These moduli can be used to estimate the extent to which SC cells deform in response to the pressure drop across the inner wall endothelium and thereby estimate the extent to which they can generate outflow resistance.  相似文献   
3.
Breast cancers show a lack of response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), despite 30% of tumors expressing EGFR. The mechanism of this resistance is unknown; however, we have recently shown that Met kinase activity compensates for loss of EGFR kinase activity in cell culture models. Met has been implicated in the pathogenesis of breast tumors and therefore may cooperate with EGFR for tumor growth. Here we have found that EGFR phosphorylation and cell proliferation is in part regulated by Met expression. In addition, we found that Met constitutive phosphorylation occurred independent of the Met ligand hepatocyte growth factor (HGF). Ligand-independent Met phosphorylation is mediated by Met amplification, mutation, or overexpression and by Met interaction with other cell surface molecules. In SUM229 breast cancer cells, we found that Met was not amplified or mutated, however it was overexpressed. Met overexpression did not directly correlate with ligand-independent Met phosphorylation as the SUM229 cell line was the only Met expressing breast cancer line with constitutive Met phosphorylation. Interestingly, Met expression did correlate with EGFR expression and we identified an EGFR/Met complex via co-immunoprecipitation. However, we only observed Met constitutive phosphorylation when c-Src also was part of this complex. Ligand-independent phosphorylation of Met was decreased by down regulating EGFR expression or by inhibiting c-Src kinase activity. Lastly, inhibiting EGFR and Met kinase activities resulted in a synergistic decrease in cell proliferation, supporting the idea that EGFR and Met functionally, as well as physically interact in breast cancer cells to regulate response to EGFR inhibitors.  相似文献   
4.

Background

Infection remains the most common cause of death from toxicity in children with cancer in low- and middle-income countries. Rapid administration of antibiotics when fever develops can prevent progression to sepsis and shock, and serves as an important indicator of the quality of care in children with acute lymphoblastic leukemia and acute myeloid leukemia. We analyzed factors associated with (1) Longer times from fever onset to hospital presentation/antibiotic treatment and (2) Sepsis and infection-related mortality.

Method

This prospective cohort study included children aged 0–16 years with newly diagnosed acute leukemia treated at Benjamin Bloom Hospital, San Salvador. We interviewed parents/caregivers within one month of diagnosis and at the onset of each new febrile episode. Times from initial fever to first antibiotic administration and occurrence of sepsis and infection-related mortality were documented.

Findings

Of 251 children enrolled, 215 had acute lymphoblastic leukemia (85.7%). Among 269 outpatient febrile episodes, median times from fever to deciding to seek medical care was 10.0 hours (interquartile range [IQR] 5.0–20.0), and from decision to seek care to first hospital visit was 1.8 hours (IQR 1.0–3.0). Forty-seven (17.5%) patients developed sepsis and 7 (2.6%) died of infection. Maternal illiteracy was associated with longer time from fever to decision to seek care (P = 0.029) and sepsis (odds ratio [OR] 3.06, 95% confidence interval [CI] 1.09–8.63; P = 0.034). More infectious deaths occurred in those with longer travel time to hospital (OR 1.36, 95% CI 1.03–1.81; P = 0.031) and in families with an annual household income InterpretationIlliteracy, poverty, and longer travel times are associated with delays in assessment and treatment of fever and with sepsis and infectious mortality in pediatric leukemia. Providing additional education to high-risk families and staying at a nearby guest house during periods of neutropenia may decrease sepsis and infectious mortality.  相似文献   
5.
    
Hypertension, a risk factor for atherosclerosis, increases the uptake of low density lipoproteins (LDL) by the arterial wall. Our objective in this work was to use computational modeling to identify physical factors that could be partially responsible for this effect. Fluid flow and mass transfer patterns in the lumen and wall of an arterial model were computed in a coupled manner, replicating as closely as possible previous experimental studies in which LDL uptake into the artery wall was measured in straight, excised arterial segments. Under conditions of both flow and no-flow, simulations predicted an increase in concentration polarization of LDL at the artery wall when arterial pressure was increased from 120 to 160 mmHg. However, this led to only a slight increase in mean LDL concentration within the arterial wall. However, if the permeability of the endothelium to LDL was allowed to vary with intra-arterial pressure, then the simulations predicted that the uptake of LDL would be enhanced 1.9-2.6 fold at higher pressure. The magnitude of this increase was consistent with experimental data. We conclude that the concentration polarization effects, enhanced by elevated intra-arterial pressure, cannot explain the increase in LDL uptake seen under hypertensive conditions. Instead, the data are most consistent with a pressure-linked increase in endothelial permeability to LDL.  相似文献   
6.
Proteomics is an emerging field that uses many types of proteomic platforms however has few standardized procedures. Deciding which platform to use to perform large-scale proteomic studies is either based on personal preference or on so-called "figures of merit" such as dynamic range, resolution, and the limit of detection; these factors are often insufficient to predict the outcome of the experiment as the detection of peptides correlates to the chemical properties of each peptide. There is a need for a novel figure of merit that describes the overall performance of a platform based on measured output, which in proteomics is often a list of identified peptides. We report the development of such a figure of merit based on a predictive genetic algorithm. This algorithm takes into account the properties of the observed peptides such as length, hydrophobicity, and pI. Several large-scale studies that differed in sample type or platform were used to demonstrate the usefulness of the algorithm for improved experimental design. The figures that were obtained were clustered to find platforms that were biased in similar ways. Even though some platforms are different, they lead to the identification of similar peptide types and are thus redundant. The algorithm can thus be used as an exploratory tool to suggest a minimal number of complementary experiments in order to maximize experimental efficiency.  相似文献   
7.
The effects of L-641,953 (R-8-fluoro-dibenzo[b, f]thiepin-3-carboxylic acid-5-oxide) have been studied on pulmonary and other smooth muscle preparations in vitro and in vivo. When studied in vitro on guinea-pig tracheal chains, L-641,933 produced significant shifts in the dose-response curves to the prostaglandin endoperoxide analogues, U-44069 (pA2 7.06) and U-46619 (pA2 7.14), and prostaglandin (PG) F2 alpha (pA2 6.33) had minimal activity against contractions induced by histamine (pA2 4.38), 5-hydroxytryptamine (pA2 4.63), and acetylcholine (pA2 4.56) and slightly enhanced relaxation induced by PGE2. When tested on the guinea-pig gall bladder strip in vitro, L-641,953 antagonized contractions induced by U-44069 (pA2 7.03) but was less active against those induced by PGF2 alpha (pA2 6.03), PGE1 (pA2 5.62), and histamine (pA2 4.84). When tested in vitro on the guinea-pig pulmonary artery, L-651-953 significantly antagonized contractions induced by U-44069 (pA2 7.04), U-46619 (pA2 7.14), and PGF2 alpha (pA2 7.16) but was less effective against contractions induced by histamine (pA2 4.19). Schild analysis indicated that L-641,953 was fully competitive against contractions of either the guinea-pig tracheal chain induced by U-46619 or the guinea-pig pulmonary artery induced by U-44069 and U-46619. When tested on human platelets in vitro L-641,953 inhibited aggregation induced by U-44069 (IC50 1.3 X 10(-6) M) but not ADP.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
    
Gel-free proteomics has emerged as a complement to conventional gel-based proteomics. Gel-free approaches focus on peptide or protein fractionation, but they do not address the efficiency of protein processing. We report the development of a microfluidic proteomic reactor that greatly simplifies the processing of complex proteomic samples by combining multiple proteomic steps. Rapid extraction and enrichment of proteins from complex proteomic samples or directly from cells are readily performed on the reactor. Furthermore, chemical and enzymatic treatments of proteins are performed in 50 nL effective volume, which results in an increased number of generated peptides. The products are compatible with mass spectrometry. We demonstrated that the proteomic reactor is at least 10 times more sensitive than current gel-free methodologies with one protein identified per 440 pg of protein lysate injected on the reactor. Furthermore, as little as 300 cells can be directly introduced on the proteomic reactor and analyzed by mass spectrometry.  相似文献   
9.
    
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10.
Elevated intraocular pressure is an important risk factor for the development of glaucoma, a leading cause of irreversible blindness. This ocular hypertension is due to increased hydrodynamic resistance to the drainage of aqueous humor through specialized outflow tissues, including the trabecular meshwork (TM) and the endothelial lining of Schlemm's canal. We know that glucocorticoid therapy can cause increased outflow resistance and glaucoma in susceptible individuals, that the cytoskeleton helps regulate aqueous outflow resistance, and that glucocorticoid treatment alters the actin cytoskeleton of cultured TM cells. Our purpose was to characterize the actin cytoskeleton of cells in outflow pathway tissues in situ, to characterize changes in the cytoskeleton due to dexamethasone treatment in situ, and to compare these with changes observed in cell culture. Human ocular anterior segments were perfused with or without 10(-7) M dexamethasone, and F-actin architecture was investigated by confocal laser scanning microscopy. We found that outflow pathway cells contained stress fibers, peripheral actin staining, and occasional actin "tangles." Dexamethasone treatment caused elevated IOP in several eyes and increased overall actin staining, with more actin tangles and the formation of cross-linked actin networks (CLANs). The actin architecture in TM tissues was remarkably similar to that seen in cultured TM cells. Although CLANs have been reported previously in cultured cells, this is the first report of CLANs in tissue. These cytoskeletal changes may be associated with increased aqueous humor outflow resistance after ocular glucocorticoid treatment.  相似文献   
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