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21.
We measured the amounts of three types of radiographic contrast media (RCM) that could be entrapped in liposomes prepared by the dehydration-rehydration vesicle (DRV) technique. To make DRVs, one initially makes water-containing, small unilamellar vesicles, adds contrast media and lyophilizes the mixture. Upon rehydration, the DRVs re-form, passively entrapping RCM. Diatrizoate, iohexol and iotrolan proved to be entrappable in similar amounts (diatrizoate was best), but all of these amounts were less than for other small molecules, such as carboxyfluorescein (P less than 0.05). Entrapment was directly proportional to lipid concentration (r = 0.76; P less than 0.002), and inversely related to iodine concentration (r = 0.86; P less than 0.002). Under ideal conditions with neutral lipids, 19.45 +/- 9.9% of diatrizoate was entrapped, corresponding to 1.05 +/- 0.50 g I per g lipid. These values are close to those achievable for large unilamellar vesicles. Use of an automated mixing device (the Microfluidizer) in place of sonication, facilitated production of large liposome batches and improved entrapment (P less than 0.05). Computed tomography (CT) scans of rats showed 30 and 218 HU of liver and spleen enhancement, respectively, per g I/kg injected DRVs. These studies showed this method (possible augmented by the Microfluidizer) allows efficient production of contrast-carrying liposomes. 相似文献
22.
Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial. 总被引:21,自引:0,他引:21
Heike A Bischoff Hannes B St?helin Walter Dick Regula Akos Margrith Knecht Christian Salis Matthias Nebiker Robert Theiler Michael Pfeifer Bettina Begerow Robert A Lew Martin Conzelmann 《Journal of bone and mineral research》2003,18(2):343-351
Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up&go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function. 相似文献
23.
Maroun Dick M.D. Tulio E. Bertorini M.D. Masanori Igarashi M.D. 《Developmental medicine and child neurology》1992,34(3):262-265
Respiratory failure is an unusual initial manifestation of congenital muscular dystrophy. The authors describe a case of congenital muscular dystrophy in a patient presenting with rhabdomyolysis at birth. Despite an initially poor prognosis, aggressive respiratory therapy during the neonatal period permitted normal subsequent development. The muscular dystrophy predominantly involved the respiratory muscles. 相似文献
24.
T C Greiner C P Burns F R Dick K M Henry I Mahmood 《American journal of clinical pathology》1992,98(5):522-525
Congenital dyserythropoietic anemia type II is a rare disorder that is often diagnosed in patients before age 20 years. Patients with this disorder, which is also called hereditary erythroblastic multinuclearity associated with a positive acidified serum lysis test, may have symptoms of iron overload. The purpose of this case report is to alert physicians to consider the diagnosis of congenital dyserythropoietic anemia type II in elderly patients who have anemia and iron overload. 相似文献
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Jeff A. Stanley Dick J. Drost Peter C. Williamson R. Terry Thompson 《Magnetic resonance in medicine》1995,34(1):17-24
In vivo 1H MR spectra of the prefrontal cortex acquired with the stimulated echo acquisition mode (STEAM) TE = 20 ms sequence were quantified to determine relative levels of cerebral metabolites. A priori knowledge of spectra from individual metabolites in aqueous solution was incorporated into a frequency domain quantification technique. The accuracy and precision of modeling these metabolites were investigated with simulated spectra of varying signal-to-noise ratios (SNRs) and relative metabolite levels. The efficacy of modeling in vivo data was tested by quantifying 10 repeated measures of two consecutively acquired in vivo spectra (an 8?cm3 volume of interest (VOI) and a 4?cm3 VOI positioned within the 8?cm3 VOI) on the same normal subject. The differences in levels of glutamate (Glu), phosphocreatine plus creatine (PCr+Cr) and choline-containing compounds (Cho1 between spectra from the 8? and 4?cm3 VOIs corresponded with the expected differences observed in the proportions of gray matter within the VOIs (estimated from 1H images). Correcting for the T1 and T2 relaxation, the estimated concentrations of N-acetylaspartate, PCr+Cr, Cho1, Glu, and glutamine were consistent with previous in vivo and in vitro reports. 相似文献