84 research outputs found

    Image Analysis for Cystic Fibrosis: Computer-Assisted Airway Wall and Vessel Measurements from Low-Dose, Limited Scan Lung CT Images

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    Cystic fibrosis (CF) is a life-limiting genetic disease that affects approximately 30,000 Americans. When compared to those of normal children, airways of infants and young children with CF have thicker walls and are more dilated in high-resolution computed tomographic (CT) imaging. In this study, we develop computer-assisted methods for assessment of airway and vessel dimensions from axial, limited scan CT lung images acquired at low pediatric radiation doses. Two methods (threshold- and model-based) were developed to automatically measure airway and vessel sizes for pairs identified by a user. These methods were evaluated on chest CT images from 16 pediatric patients (eight infants and eight children) with different stages of mild CF related lung disease. Results of threshold-based, corrected with regression analysis, and model-based approaches correlated well with both electronic caliper measurements made by experienced observers and spirometric measurements of lung function. While the model-based approach results correlated slightly better with the human measurements than those of the threshold method, a hybrid method, combining these two methods, resulted in the best results

    Treatment of anorexia and weight loss with megestrol acetate in patients with cystic fibrosis

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    Four patients with severe cystic fibrosis lung disease, anorexia and weight loss, received Megestrol Acetate (MA), as an appetite stimulant. The initial dose was 400–800 mg daily and was continued for 6–15 months. Appetite was improved, with significant weight gain in all patients and an increase in their weight for age percentile from <5% at the start of the study to approximately the 25 th percentile after 6 months of use and improvement in quality of life. One patient discontinued MA after 6 months, and subsequently appetite and weight were depressed. Pediatr Pulmonol. 1999; 28:380–382. © 1999 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35316/1/11_ftp.pd

    Lung Function after the Minimal Invasive Pectus Excavatum Repair (Nuss Procedure)

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    Background The Nuss procedure was introduced at our center in 1999. The operation was mainly performed for cosmesis. Little information is available regarding the influence of this operation on lung function. Methods The aim of this study, a prospective analysis, was to analyze the effect of the Nuss procedure on lung function variables. Between 1999 and 2007 a total of 203 patients with pectus excavatum were treated with the Nuss procedure, of whom 145 (104 male, 41 female) were located at Emma Children’s Hospital. In the latter subset of consecutive patients, static lung function variables [total lung capacity (TLC), functional residual capacity (FRC), vital capacity (VC)] and dynamic lung function variables [forced expired volume in 1 s (FEV1), maximum expiratory flow (MEF50)] were performed using spirometry and body box measurements at four time points: prior to operation Some of these data were presented at the International Surgical Week

    Thermal Stability of the Human Immunodeficiency Virus Type 1 (HIV-1) Receptors, CD4 and CXCR4, Reconstituted in Proteoliposomes

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    BACKGROUND: The entry of human immunodeficiency virus (HIV-1) into host cells involves the interaction of the viral exterior envelope glycoprotein, gp120, and receptors on the target cell. The HIV-1 receptors are CD4 and one of two chemokine receptors, CCR5 or CXCR4. METHODOLOGY/PRINCIPAL FINDINGS: We created proteoliposomes that contain CD4, the primary HIV-1 receptor, and one of the coreceptors, CXCR4. Antibodies against CD4 and CXCR4 specifically bound the proteoliposomes. CXCL12, the natural ligand for CXCR4, and the small-molecule CXCR4 antagonist, AMD3100, bound the proteoliposomes with affinities close to those associated with the binding of these molecules to cells expressing CXCR4 and CD4. The HIV-1 gp120 exterior envelope glycoprotein bound tightly to proteoliposomes expressing only CD4 and, in the presence of soluble CD4, bound weakly to proteoliposomes expressing only CXCR4. The thermal stability of CD4 and CXCR4 inserted into liposomes was examined. Thermal denaturation of CXCR4 followed second-order kinetics, with an activation energy (E(a)) of 269 kJ/mol (64.3 kcal/mol) and an inactivation temperature (T(i)) of 56°C. Thermal inactivation of CD4 exhibited a reaction order of 1.3, an E(a) of 278 kJ/mol (66.5 kcal/mol), and a T(i) of 52.2°C. The second-order denaturation kinetics of CXCR4 is unusual among G protein-coupled receptors, and may result from dimeric interactions between CXCR4 molecules. CONCLUSIONS/SIGNIFICANCE: Our studies with proteoliposomes containing the native HIV-1 receptors allowed an examination of the binding of biologically important ligands and revealed the higher-order denaturation kinetics of these receptors. CD4/CXCR4-proteoliposomes may be useful for the study of virus-target cell interactions and for the identification of inhibitors

    Growth And The Growth Hormone-Insulin Like Growth Factor 1 Axis In Children With Chronic Inflammation:Current Evidence, Gaps In Knowledge And Future Directions

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    Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt is often seen during adolescence. The underlying inflammatory state mediated by pro-inflammatory cytokines, prolonged use of glucocorticoid and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the growth hormone-insulin like growth factor axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate studies further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biologic therapy may lead to improvement of growth in some of these children but approximately one third continue to grow slowly. There is increasing evidence that the use of relatively high dose recombinant human growth hormone may lead to partial catch up growth in chronic inflammatory conditions, although long term follow-up data is currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease and cystic fibrosis, systemic abnormalities of the growth hormone-insulin like growth factor axis and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human growth hormone in these conditions and discuss the role of recombinant human insulin like growth factor-1

    Positive effort dependence of maximal expiratory flow

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