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排序方式: 共有3232条查询结果,搜索用时 15 毫秒
31.
Buchs A Slovik Y Rapoport M Rosenfeld C Khanokh B Nitzan M 《Medical & biological engineering & computing》2005,43(2):252-257
Photoplethysmography (PPG) records the cardiac-induced changes in tissue blood volume by light-transmission measurements.
The baseline and amplitude of the PPG signal show very low-frequency (VLF) spontaneous fluctuations, which are mediated by
the sympathetic nervous system, and high correlation between right and left extremities of healthy subjects. As sympathetic
neuropathy is one of the diabetic complications, the right-left correlation of the PPG fluctuations was examined in diabetic
patients. The PPG signal was simultaneously measured in the two index fingers and the two second toes of 35 diabetic patients
and 33 non-diabetic subjects. For each PPG pulse, the baseline and amplitude were determined, and the right-left correlation
coefficients of the VLF fluctuations in the baseline and amplitude were derived. The VLF fluctuations in the baseline showed
high right-left correlation, both for fingers (0.93±0.05) and toes (0.93±0.06), for the non-diabetic subjects, and significantly
lower correlation (0.78±0.22 and 0.84±0.17, respectively) for the diabetic patients. Similar results were obtained for the
amplitude VLF fluctuations. The right-left correlation coefficients for diabetic patients decreased with the disease duration
for the toe baseline and toe amplitude fluctuations and correlated with heart rate response to deep breathing for the finger
baseline and toe amplitude fluctuations. The right-left correlation coefficients of the PPG fluctuations provide a simple
and convenient means for assessing the adequacy of the sympathetic nervous system function. 相似文献
32.
Elsa Baehr Peter Rosenfeld Laura Miller Rufus Baehr 《International journal of psychophysiology》2004,52(2):159-167
OBJECTIVE: Since the clinical picture of premenstrual dysphoric disorder (PMDD) in the Luteal phase of the menstrual cycle is characterized by extreme negative affect, we predicted and obtained a change in frontal cortical EEG alpha asymmetry, which has been shown to be an index of affect. METHOD: We observed two monthly cycles for five women diagnosed as having PMDD and one monthly cycle for five non-PMDD control subjects. RESULTS: Asymmetry percent scores for the five PMDD women, and for the five control subjects before and after the Luteal phase were typically within the normal non-depressed range, however the asymmetry scores for the PMDD group fell into the negative range during the Luteal period while the control subjects remained stable. DISCUSSION: We predicted alpha asymmetry scores would be affected by the luteal phase in PMDD cases. This hypothesis was clearly confirmed. 相似文献
33.
Maureen Handoko Lisa T. Emrick Jill A. Rosenfeld Xia Wang Alyssa A. Tran Alicia Turner John W. Belmont Undiagnosed Diseases Network Brendan H. Lee Carlos A. Bacino Hsiao‐Tuan Chao 《American journal of medical genetics. Part A》2019,179(3):475-479
Genetic alterations leading to overactivation of mammalian target of rapamycin (mTOR) signaling result in brain overgrowth syndromes such as focal cortical dysplasia (FCD) and megalencephaly. Megalencephaly with cutis tri‐color of the Blaschko‐linear type pigmentary mosaicism and intellectual disability is a rare neurodevelopmental disorder attributed to the recurrent mosaic c.5930C > T (p.Thr1977Ile) MTOR variant. This variant was previously reported at low to intermediate levels of mosaicism in the peripheral blood of three unrelated individuals with consistent clinical findings. We report a fourth case of a 3‐year‐old female presenting with megalencephaly, obstructive hydrocephalus due to cerebral aqueductal stenosis, asymmetric polymicrogyria, dysgenesis of the corpus callosum, hypotonia, developmental delay, and cutaneous pigmentary mosaicism. Oligonucleotide and SNP chromosomal microarray (CMA), karyotype, and trio whole exome sequencing (WES) in the peripheral blood, as well as a targeted gene variant panel from fibroblasts derived from hyperpigmented and non‐hyperpigmented skin did not detect any abnormalities in MTOR or other genes associated with brain overgrowth syndromes. Unlike the previously reported cases, the de novo c.5930C > T (p.Thr1977Ile) MTOR variant was detected at 32% mosaicism in our patient only after WES was performed on fibroblast‐derived DNA from the hyperpigmented skin. This case demonstrates the tissue variability in mosaic expression of the recurrent p.Thr1977Ile MTOR variant, emphasizes the need for skin biopsies in the genetic evaluation of patients with skin pigmentary mosaicism, and expands the clinical phenotype associated with this pathogenic MTOR variant. 相似文献
34.
35.
Shalman E Barak C Dgany E Noskowitcz H Einav S Rosenfeld M 《Computers in biology and medicine》2001,31(5):353-363
Arterial stenosis is known to be one of the most serious cardiovascular diseases. Angiographical estimation of arterial stenosis provides limited information on the severity of the occlusion and the flow of blood through it. Hemodynamical assessment of the flow and pressure behaviour, is known to be clinically important. Hemodynamically based parameters, such as pressure based myocardial fractional flow reserve (FFR) and the flow based coronary flow reserved (CFR) were introduced to provide a much better tool for treating arterial diseases.We have developed a new method for simultaneous measurement of pressure-derived CFR and FFR. The advantage of pressure derived hemodynamic parameters is very substantial, and its relatively straightforward application in clinical setting is solid. The method has been validated by means of a computational fluid dynamics (CFD) model of the arterial stenosis and in vitro bench studies. 相似文献
36.
37.
Association of volume with outcome of coronary artery bypass graft surgery. Scheduled vs nonscheduled operations 总被引:14,自引:3,他引:11
J A Showstack K E Rosenfeld D W Garnick H S Luft R W Schaffarzick J Fowles 《JAMA》1987,257(6):785-789
Empirical evidence suggests that mortality rates for coronary artery bypass graft (CABG) surgery are lower in hospitals that perform a higher volume of the procedure. In recent years, the criteria for CABG surgery have been expanded to include patients with a wide variety of co-morbidities. To address the question of whether the volume-outcome relationship continues to exist for this new group of patients, discharge abstracts for 18,986 CABG operations at 77 hospitals in California in 1983 were analyzed using multiple-regression techniques. Higher-volume hospitals had lower in-hospital mortality (adjusted for case mix); this effect was greatest in patients who might be characterized as having "non-scheduled" CABG surgery. Higher-volume hospitals also had shorter average postoperative lengths of stay and fewer patients with extremely long stays. The results of this study suggest that the greatest improvement in average outcomes for CABG surgery would result from the closure of low-volume surgery units. 相似文献
38.
39.
Dave P. Nichols Scott H. Donaldson Carla A. Frederick Steven D. Freedman Daniel Gelfond Lucas R. Hoffman Andrea Kelly Michael R. Narkewicz Jessica E. Pittman Felix Ratjen Scott D. Sagel Margaret Rosenfeld Sarah Jane Schwarzenberg Pradeep K. Singh George M. Solomon Michael S. Stalvey Shannon Kirby Jill M. VanDalfsen Steven M. Rowe 《Journal of cystic fibrosis》2021,20(2):205-212
Highly effective CFTR modulator drug therapy is increasingly available to those with cystic fibrosis. Multiple observational research studies are now being conducted to better understand the impacts of this important therapeutic milestone on long-term outcomes, patient care needs, and future research priorities. PROMISE is a large, multi-disciplinary academic study focused on the broad impacts of starting elexacaftor/tezacaftor/ivacaftor in the US population age 6 years and older. The many areas of investigation and rationale for each are discussed by organ systems, along with recognition of remaining important questions that will not be addressed by this study alone. Knowledge gained through this and multiple complementary studies around the world will help to understand important health outcomes, clinical care priorities, and research needs for a large majority of people treated with these or similarly effective medications targeting the primary cellular impairment in cystic fibrosis. 相似文献
40.
SUMMARY Previous studies have shown that premature infants may be at risk for hypoxemia and bradycardia when placed in standard car seats. However, the relationship of such breathing abnormalities to sleep state have not been studied. The purpose of the present study was to investigate the effect of car seat positioning on respiratory patterns in preterm infants during sleep and to evaluate their relationship to sleep state. Complete polysomnography, including sleep and breathing parameters, was performed on twenty-eight premature infants. Each infant was randomly assigned to the car seat or prone (crib) position for the first recording period. Following the recording of at least two sleep cycles, the position was reversed. The percentage of active and quiet sleep was calculated and breathing parameters were measured. In the car seat, the infants spent significantly more time in active sleep and less time in quiet sleep than in the prone position, of the respiratory parameters, periodic breathing (PB) was significantly higher in the car seat. The presence of at least one abnormal breathing events (bradycardia, desaturation, PB apnoea) was also significantly higher in the car seat. An analysis of variance (ANOVA) of PB revealed significant sleep-state effect (active vs. quiet sleep), but no significant condition or interaction effects, indicating that PB was more frequent in active sleep regardless of the sleeping condition. It is concluded that increased active sleep in the car seat condition, rather than the positioning of the infant in the seat per se, may account for the increase in periodic breathing and possibly other breathing abnormalities reported in car seats. 相似文献