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151.
B Murphy C.N Nunes J.J Ronan C.M Harper M.J Beall M Hanaway A.M Fairhurst L.H.T Van der Ploeg D.E Maclntyre T.N Mellin 《Neuropeptides》1998,32(6):491-497
Melanocortinergic neurons are believed to play a role in the control of food intake. Melanocortin receptor agonists and antagonists modulate feeding in several mouse models of chemically and genetically induced hyperphagia. To date, little information is available describing the role of this neurological system in the control of the natural feeding cycle in genetically intact rats.To evaluate the involvement of melanocortins in spontaneous nocturnal feeding, the synthetic melanocortin receptor agonist, MTII and the antagonist, SHU9119 were administered ICV (third ventricle) alone and in combination. Dose-dependent inhibition or stimulation of food intake was observed with MTII or SHU9119, respectively. Co-injections containing equal concentrations of MTII and SHU9119 resulted in food intake that was indistinguishable from controls. Food intake patterns observed in studies in which various dose combinations of MTII and SHU9119 were co-injected are consistent with the concept that both affect feeding by acting on similar melanocortin receptors.The hypothesis that effects of melanocortins on feeding may be mediated via an NPY related pathway was tested by co-injecting MTII and NPY in a 2-h satiated food intake paradigm. MTII inhibited food intake induced by 5.0 μg hNPY in a dose dependent manner with the highest dose tested abolishing the NPY feeding response.The studies suggest that melanocortins act via specific receptors to control food intake in rats, possibly via an NPY related pathway. If similar neurochemical processes operate in humans, selectively modulating specific melanocortin receptor signaling may be an approach to the treatment of human obesity. 相似文献
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154.
A C Beall Jr D L Bricker F J Alessi H H Whisennand M E DeBakey 《Annals of surgery》1971,173(6):971-978
155.
Zollikofer CL; Cragg AH; Einzig S; Castaneda-Zuniga WR; Castaneda F; Rysavy JA; Bruhlmann WF; Shebuski RJ; Amplatz K 《Radiology》1983,149(3):681-685
To prevent platelet aggregation following percutaneous transluminal angioplasty (PTA), cyclooxygenase inhibitors such as acetylsalicylic acid (ASA) and indomethacin are recommended. However, ASA blocks both the proaggregating effects of thromboxane (TXA2) and the antiaggregating and vasodilating effects of prostacyclin (PGI2). The authors measured the contractile response of dilated canine carotid arteries in situ and in vitro using an isometric force transducer. Following PTA, contraction of the arterial wall was significantly reduced (p less than 0.01). By blocking cyclooxygenase with indomethacin (3 micrograms/ml), contraction was greatly improved (p less than 0.001). These results suggest that PTA may result in marked release of prostacyclin by the damaged arterial wall, which could account for the decreased responsiveness of the artery to exogenous norepinephrine. 相似文献
156.
HAKAN SENTURK SEVAL ERDINÇCL MUSTAFA TASYUREKLI ALI MERT MACIT ARVAS CIHAT SEN 《Journal of gastroenterology and hepatology》1996,11(7):617-620
Rare causes of liver dysfunction in pregnancy may pose a challenge to the consulting gastroenterologist or hepatologist from both the diagnostic and therapeutic standpoints. We describe here liver function abnormalities in a case of hyperreactio luteinalis with light and electron microscopic findings. 相似文献
157.
3-D femoral stress analysis using CT scans and p-version FEM 总被引:1,自引:0,他引:1
P K Basu A G Beall D J Simmons M Vannier 《Biomaterials, medical devices, and artificial organs》1985,13(3-4):163-186
The potential of the finite element method as a computational aid for making objective clinical decisions has not yet been exploited due to the unreliability of the results obtained. The main reasons for this may be attributed to the poor quality of the finite elements available in the conventional softwares, improper modeling of the three dimensional problem, and errors introduced by incorrect representation of geometry and material properties. Herein, we report an attempt to derive a three-dimensional finite element model for the adult human femur which permits reliable representation of the local stress patterns. The geometry was obtained by serial computed tomography scans. The mechanical properties were based on laboratory tests and information available in the literature. The analysis is performed with a new generation software. Preliminary results suggest that the scheme could be automated and used for in vivo analysis. 相似文献
158.
To calculate the centre of pressure using piezoelectric force plates mounted on pads, no net tensile stresses may be imposed on the surface of the plate. This condition is violated when stairs are attached to the plates, unless the plates are preloaded. Typical shear forces encountered when climbing stairs were used to determine required preloads of approximately 16.4 N/cm step height. Vertical and horizontal loads were applied at known locations on the steps, and points of application were calculated. Deviations were within ± 3 mm. The effect of point of application inaccuracy on calculated joint moments is considerable. A 2 cm medial shift in the point of application resulted in calculated peak knee abduction/adduction moment errors of 35%. 相似文献
159.
160.
R. Thomas Solis George P. Noon Arthur C. Beall Michael E. DeBakey 《The Annals of thoracic surgery》1974,17(4):332-344
In order to quantitate particulate microembolism during cardiac operations, particles 13 to 80 μ in size were measured, with a particle size analyzer, in the blood of patients before and during cardiopulmonary bypass. Venous particle measurements did not change. The volume of particles in arterial blood drawn from the bubble oxygenator (41.3 ± 4.4 × 103 μ3/mm.3, mean ± SE) was greater than that in venous blood (30.7 ± 4.1 × 103 μ3/mm.31987, p < 0.05) only during the first 10 minutes on bypass. In contrast, the volume of particles in blood drawn from the cardiotomy return line was markedly elevated (903 ± 121 × 103 μ3/mm.3). These microemboli remained elevated throughout the procedure, were most evident when extravasated blood was collected with the coronary suction line, and had a size distribution similar to platelet aggregates which could be induced in vitro in the patient's blood. The microemboli differed from platelet aggregates in that they were more resistant to deaggregation in vitro and a greater percentage (17%) floated into plasma after centrifugation. A Dacron wool filter removed 89% of these microemboli, while a 40 μ pore mesh filter and a polyurethane foam filter removed 58 and 64%, respectively. The data thus indicate that Dacron wool filtration of blood infused through the cardiotomy system would virtually eliminate particulate microembolism during cardiopulmonary bypass. 相似文献