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Measurements of the neutral weak-vector form factors of the nucleon provide unique access to the strange quark content of the nucleon. These form factors can be studied by using parity-violating electron scattering. A comprehensive program of experiments has been performed at three accelerator laboratories to determine the role of strange quarks in the electromagnetic form factors of the nucleon. This article reviews the remarkable technical progress associated with this program, describes the various methods used in the different experiments, and summarizes the physics results along with recent theoretical calculations. [ABSTRACT FROM AUTHOR]

Objectives: Vitamin A and E deficiency is common in cystic fibrosis (CF). These vitamins have immunomodulating properties and we determined whether decreased serum vitamin A and E levels in young infants are associated with early CF lung disease and lower airway inflammation. Methods: A post-hoc analysis was undertaken on previous data collected prospectively in 39 newly diagnosed infants identified by a newborn CF screening programme. Assessment of CF genotype, nutrition, pancreatic status, serum retinol and α-tocopherol levels was performed at diagnosis. Pulmonary status was determined clinically, by Brasfield chest radiographic scores and analysis of bacterial counts and inflammatory indices in bronchial lavage (BL) fluid. These assessments were repeated 12 months later. Results: At diagnosis, 20 out of 39 (51%) CF infants had low serum retinol (mean (SD) 0.7 (0.3) μmol/L) and 9/38 (24%) had low α-tocopherol (mean (SD) 13.4 (8.4) μmol/L) levels. Dietary energy intake was related to serum retinol concentrations at diagnosis ( r2 = 0.27; P = 0.001). At 1 year, serum retinol and α-tocopherol levels had normalized following vitamin A and E supplementation. Respiratory symptoms, radiographic scores and BL inflammatory indices systematically deteriorated during infancy, reaching significance for free neutrophil elastase activity (9 out of 29 vs 21 out of 33; P = 0.01) and IL-8 levels (79 vs 416; P = 0.046) in BL fluid. No association was seen between serum vitamin levels at diagnosis and airway inflammatory indices at either diagnosis or 12 months later. Conclusion: We found in this CF birth cohort no evidence to implicate vitamin A or E deficiency in the development of lung disease or airway inflammation during infancy. [ABSTRACT FROM AUTHOR]

Aims: To determine the relation between lower airway infection and inflammation, respiratory symptoms, and lung function in infants and young children with cystic fibrosis (CF). Methods: A prospective study of children with CF aged younger than 3 years, diagnosed by a newborn screening programme. All were clinically stable and had testing as outpatients. Subjects underwent bronchial lavage (BL) and lung function testing by the raised volume rapid thoracoabdominal compression technique under general anaesthesia. BL fluid was cultured and analysed for neutrophil count, interleukin 8, and neutrophil elastase. Lung function was assessed by forced expiratory volume in 0.5, 0.75, and 1 second. Results: Thirty six children with CF were tested on 54 occasions. Lower airway infection shown by BL was associated with a 10% reduction in FEV[sub 0.5] compared with subjects without infection. No relation was identified between airway inflammation and lung function. Daily moist cough within the week before testing was reported on 20/54 occasions, but in only seven (35%) was infection detected. Independent of either infection status or airway inflammation, those with daily cough had lower lung function than those without respiratory symptoms at the time of BL (mean adjusted FEV[sub 0.5] 195 ml and 236 ml respectively). Conclusions: In young children with CF, both respiratory symptoms and airway infection have independent, additive effects on lung function, unrelated to airway inflammation. Further studies are needed to understand the mechanisms of airway obstruction in these young patients. [ABSTRACT FROM AUTHOR]

Respiratory syncytial virus (RSV) lower respiratory tract infections are common, yet long-term sequelae in previously healthy infants and children are rarely reported. We report a child who developed bronchiectasis and bronchiolitis obliterans following an RSV lower respiratory tract infection but in whom adenovirus was detected on stored serum. Co-infection with adenovirus is the likely cause for the bronchiectasis and bronchiolitis obliterans. [ABSTRACT FROM AUTHOR]