The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%. 相似文献
Objective: To test whether ventilatory thresholds, measured during an exercise test, could be assessed using time varying analysis of respiratory sinus arrhythmia frequency (fRSA).
Methods: Fourteen sedentary subjects and 12 endurance athletes performed a graded and maximal exercise test on a cycle ergometer: initial load 75 W (sedentary subjects) and 150 W (athletes), increments 37.5 W/2 min. fRSA was extracted from heart period series using an evolutive model. First (TV1) and second (TV2) ventilatory thresholds were determined from the time course curves of ventilation and ventilatory equivalents for O2 and CO2.
Results:fRSA was accurately extracted from all recordings and positively correlated to respiratory frequency (r = 0.96 (0.03), p<0.01). In 21 of the 26 subjects, two successive non-linear increases were determined in fRSA, defining the first (TRSA1) and second (TRSA2) fRSA thresholds. When expressed as a function of power, TRSA1 and TRSA2 were not significantly different from and closely linked to TV1 (r = 0.99, p<0.001) and TV2 (r = 0.99, p<0.001), respectively. In the five remaining subjects, only one non-linear increase was observed close to TV2. Significant differences (p<0.04) were found between athlete and sedentary groups when TRSA1 and TRSA2 were expressed in terms of absolute and relative power and percentage of maximal aerobic power. In the sedentary group, TRSA1 and TRSA2 were 150.3 (18.7) W and 198.3 (28.8) W, respectively, whereas in the athlete group TRSA1 and TRSA2 were 247.3 (32.8) W and 316.0 (28.8) W, respectively.
Conclusions: Dynamic analysis of fRSA provides a useful tool for identifying ventilatory thresholds during graded and maximal exercise test in sedentary subjects and athletes.
The past 4 years have seen a growing interest in cholesterol metabolism and its relationship to Alzheimer's disease. From the first report linking cholesterol and beta-amyloid metabolisms to the recent positive report on the use of atorvastatin (Lipitor, Pfizer Inc.), a cholesterol-lowering drug, in mild-to-moderate Alzheimer's disease, this review examines the scientific progress pertaining to etiopathology of Alzheimer's disease over the past 15 years and the central role of lipids in this field of research. The role of key proteins involved in this metabolic pathway such as apolipoprotein E, lipoprotein lipase, caveolin, hydroxy-methylglutaryl Coenzyme A reductase, low-density lipoprotein receptors, cholesterol 24-hydroxylase, acyl-coenzyme A:cholesterol acyltransferase and beta-amyloid are discussed. 相似文献
Idiopathic polypoidal choroidal vasculopathy (IPCV) has recently been recognized as a distinct cause of recurrent subretinal hemorrhages and exudates as well as multiple hemorrhagic retinal pigment epithelium detachments in the macula. IPCV is usually considered to have a good visual prognosis. We report the case of a 44-year-old woman with particularly severe bilateral macular and peripheral IPCV. The patient was followed for 13 years and had final visual acuity of counting fingers in the right eye and 20/400 in the left eye. Patients with IPCV with macular choroidal neovascularization tend to have a poor visual prognosis. This case of IPCV should alert the physician to be particularly attentive to the follow-up of these patients. 相似文献
The present paper examines the susceptibility to chlordecone (Kepone, CD) and carbon tetrachloride across different ages (35, 45, and 63-days-old) in male and female Sprague-Dawley rats using different lengths of time on a CD diet (10 ppm). The principal findings are that the hepatotoxicity and mortality associated with CD-CCl4 interaction is highly age-dependent for both sexes. There was marked hepatotoxicity occurring in both sexes as they reached 45 days-of-age and females were considerably more susceptible than males to both CD-CCl4-induced hepatotoxicity and lethality. While 63-day-old females are more susceptible to the CD-CCl4 interaction than their male counterparts, the magnitude of the sex difference is diminished from that observed in 45-day-old rats. These findings challenge the hypothesis of Mehendale (1990, Med. Hypotheses 33, 289-299) that chlordecone (CD) pretreatment eliminates the well-established sex difference in CCl4-treated rats. In contrast to the CD-CCl4 findings, the sex difference in CCl4-induced hepatotoxicity was not age-dependent and was consistent over the three ages studied. The findings that CD-CCl4 interaction is highly age-dependent (within the 3 ages tested) but that CCl4-induced hepatotoxicity is not, suggest that the CD-CCl4 interaction acts via a mechanism that does not primarily involve CCl4 potentiation. 相似文献