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A 31P NMR method based on pH dependent variation of the chemical-shift-difference between the resonances of orthophosphate and methylphosphonate was used to measure simultaneously intracellular pH (pHi) and extracellular pH (pHc) during long term storage of erythrocytes; pH was determined at both 4 degrees C and 37 degrees C. An equation describing the equilibrium distribution of membrane-permeant ions was derived by consideration of the electrochemical and osmotic constraints in the RBC suspension. Calculations using the model-equation and the measured pHi yielded the Donnan ratio and therefore pHo; the relationship between experimentally determined pHi and pHo values was accurately predicted by the model. Sensitivity analysis of the model-equation revealed that the observed increase in transmembrane pH gradient during storage is principally due to the alteration of the total net charge of intracellular (poly)-anions. 相似文献
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Moore AD; Godwin JD; Muller NL; Naidich DP; Hammar SP; Buschman DL; Takasugi JE; de Carvalho CR 《Radiology》1989,172(1):249-254
The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities. 相似文献
65.
Among 600 infants examined with ultrasound for vomiting, seven (mean age, 3 months) had distinctive features that can be considered diagnostic of gastric ulcer. The findings are thickening of the mucosa (greater than 4 mm) in the antropyloric region, elongation of the antropyloric canal, persistent spasm, and delayed gastric emptying. Two of the infants had slight thickening of the pyloric muscle. Gastrointestinal series or endoscopy demonstrated thickened gastric mucosa and a deformed gastric antrum in all infants, as well as actual ulceration in five. 相似文献
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An improved catheter for pulmonary arteriography via the antecubital approach is described. The catheter has been used successfully in 56 patients. 相似文献
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Sanne C Hammer Charlotte MHHT Robroeks Christian van Rij Jan Heynens Richard Droog Quirijn Jöbsis Han JE Hendriks Edward Dompeling 《Pediatric allergy and immunology》2008,19(7):626-633
Several epidemiological studies described poor asthma control in children. However, the diagnosis of childhood asthma in these studies is uncertain, and asthma control in children of an outpatient clinic population during treatment by a paediatrician is unknown. (1) to investigate the hypothesis that asthma control in a paediatric outpatient clinic population is better than epidemiological surveys suggest; (2) to find possible explanations for suboptimal asthma control. Asthmatic children aged 6–16 years, known for at least 6 months by a paediatrician at the outpatient clinic, were selected. During a normal visit, both the responsible physicians and parent/children completed a standardised questionnaire about asthma symptoms, limitation of daily activities, treatment, asthma attacks and emergency visits. Overall, excellent asthma control of 8.0% in this study was not significantly better than of 5.8% in the European AIR study (Chi‐square, p = 0.24). Separate GINA goals like minimal chronic symptoms and no limitation of activities were better met in our study. Good to excellent controlled asthma was perceived by most children/parents (83%), but was less frequently indicated by the paediatrician (73%), or by objective criteria of control (45%) (chi‐square, p = 0.0001). The agreement between patient‐perceived and doctor assessed control was low, but improved in poorly controlled children. Patients were not able to perceive the difference between ‘excellent asthma control’ and ‘good control’ (p = 0.881).Too little children with uncontrolled disease got step‐up of their asthma treatment. Although separate GINA goals like ‘minimal chronic symptoms’ and ‘no limitation of activities’ were significantly better in our study, overall, asthma control in this outpatient clinic population, treated by a paediatrician, was not significantly better than in the European AIR study. Poorly controlled disease was related to several aspects of asthma management, which are potentially accessible for improvements. 相似文献
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