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971.
R H Beekman V Katch C Marks A P Rocchini 《Medicine and science in sports and exercise》1984,16(3):306-310
To validate the CO2-rebreathing method ( Defare 's method) for estimating cardiac output in children and young adults, measurements were compared to thermodilution ( TDCO ) cardiac output in 16 subjects (age 7-19 yr) with congenital heart disease. Data were collected at rest (N = 11) and during 4-min stages of supine bicycle exercise (N = 13). Estimated arterial-venous (-v-a)CO2 content differences related linearly to the measured CO2 content difference (Y = 0. 29X + 2.47, r = 0.65, P less than 0.001). With this (v-a)CO2 difference correction for all patients (N = 16), the correlation between CO2-rebreathing cardiac output and the TDCO was r = 0.87 (SEE = +/- 1.8 l X min-1). The correlation was higher for exercise (r = 0.81) than for rest (r = 0.65). We conclude that the CO2-rebreathing method, with a (v-a)CO2 content difference adjustment, is a simple, noninvasive technique providing estimates of cardiac output in children and young adults with congenital heart disease. Individual estimates should be treated with caution, especially when used for clinical evaluations. 相似文献
972.
Assay of glyceryl trinitrate, isosorbide dinitrate, and their metabolites in plasma by large-bore capillary column gas-liquid chromatography 总被引:2,自引:0,他引:2
B P Booth B M Bennett J F Brien D A Elliott G S Marks J L McCans K Nakatsu 《Biopharmaceutics & drug disposition》1990,11(8):663-677
Two large-bore capillary columns, one with dimethyl polysiloxane (HP-1) as the stationary phase and the other with phenyl (50 per cent) methyl (50 per cent) polysiloxane (DB-17), were used to develop gas-liquid chromatographic (GLC) assays for measuring isosorbide dinitrate (ISDN), glyceryl trinitrate (GTN), and their metabolites. ISDN, isosorbide-2-mononitrate (2-ISMN), and isosorbide-5-mononitrate (5-ISMN) in plasma, ranging in concentration from 1 to 300 nM, and GTN, glyceryl-1,2-dinitrate (1,2-GDN), and glyceryl-1,3-dinitrate (1,3-GDN), ranging in concentration from 3 to 60 nM in plasma, were analysed on both columns. GLC analysis yielded baseline resolution of the analytes. The method using the dimethyl polysiloxane column gave a lower limit of detectability for GTN of 0.75 nM (signal/noise (s/n) = 2), and the procedure using the phenyl-methyl column provided a lower limit of detectability for ISDN of 81 pM (s/n = 2). The large-bore column GLC procedures exhibited shorter retention times for both ISDN and GTN than those previously reported for capillary-column assays. The chromatographic resolution of analytes and column efficiency of the large-bore capillary columns were comparable to the results previously found using capillary-column GC. The assays for ISDN and GTN have been shown to be appropriate for pharmacokinetic studies in volunteers and patients. We determined that the HP-1 column is appropriate for the analysis of GTN and metabolites, and the DB-17 column is suitable for analysis of ISDN and its metabolites. We conclude that the use of large-bore capillary columns provides rapid and reliable GLC assays for organic nitrates. 相似文献
973.
S C Marks 《International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association》1979,47(1):26-32
Osteoclasts and osteolytic osteocytes have been observed in the majority of 60 samples of bone taken from five patients with lepromatous or tuberculoid leprosy. These results are interpreted to mean that bone loss in patients with leprosy is an acceleration of a normal cellular process and not the result of avascular necrosis. The acceleration of bone resorption could be due to local release of products from M. leprae or host cells, a hypothesis testable by organ culture methods. The presence of lymphocytes and mononuclear cells in bone samples in this and previous studies is discussed with respect to recent evidence of a role for lymphoid cells in bone resorption. 相似文献
974.
R C Stuart T F Gorey E Kay P Marks P J Byrne T P Hennessy 《Journal of the Royal College of Surgeons of Edinburgh》1989,34(6):321-325
Acute gastric stress ulceration was induced in rats by cold restraint and was not associated with alteration of gastric pH or serum gastrin level. Cimetidine and oral and intravenous allopurinol were prophylactic but allopurinol was more effective in reducing the depth of the lesion and acted without alteration in gastric pH. The efficacy of allopurinol in preventing stress ulceration offers further indirect evidence of the role of ischaemia and oxygen free radical generation in the aetiology of stress ulceration. 相似文献
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979.
Torulopsis glabrata--an opportunistic pathogen in man 总被引:4,自引:0,他引:4
980.