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排序方式: 共有10000条查询结果,搜索用时 626 毫秒
61.
Tarek Sadek Hakim Mazouz Hedi Bahloul Roxana Oprisiu Najeh El Esper Isabelle El Esper Francis Boitte Michel Brazier Philippe Moriniere Albert Fournier 《Nephrology, dialysis, transplantation》2003,18(3):582-588
BACKGROUND: Sevelamer hydrochloride was recently proposed as a phosphate binder to prevent hypercalcaemia in place of calcium alkaline salts in dialysis patients. So far, it has been evaluated only in patients receiving calcitriol, without comparison with CaCO(3) alone, although the latter was found to be as effective as the combination of calcitriol and Al(OH)(3) in suppressing parathyroid hormone (PTH) without inducing hypercalcaemia and to have a better lowering effect on serum phosphate. Moreover, this bile salt binder may decrease serum 25-OH vitamin D. Therefore, we compared for 5 months two strategies for controlling moderate hyperparathyroidism: CaCO(3) alone vs sevelamer in conjunction with measures to increase calcium balance. METHODS: Forty-two patients were randomized: 21 continued their treatment with 4.8 g/day CaCO(3) and 21 were switched to sevelamer (initial dose: 2.4 g/day, increased to 4.4 g/day). Each month, when serum-corrected calcium decreased below 2.30 mmol/l, dialysate calcium was increased or alphacalcidol was given at each dialysis session, according to serum PO(4) levels. The following parameters were monitored: serum Ca, PO(4), bicarbonate and protein, weekly; and serum PTH, 25-OH vitamin D and total, LDL and HDL cholesterol monthly. RESULTS: Except for higher serum phosphate at month 1, lower serum bicarbonate at month 2 and lower LDL cholesterol at month 5 in the sevelamer group, no difference was found between the two groups. Compared with baseline levels, PTH increased and 25-OH vitamin D decreased significantly in both groups, these two parameters being inversely correlated. CONCLUSIONS: Given comparable control of plasma calcium, phosphate and 25-OH vitamin D, PTH control is comparable in both strategies. Sevelamer does not induce greater vitamin D depletion than CaCO(3). The transient decrease of serum bicarbonate after discontinuation of CaCO(3) in the sevelamer group suggests a less optimal prevention of acidosis. The sevelamer-induced decrease in LDL cholesterol gives this drug a potential advantage in cardiovascular prevention. 相似文献
62.
We report on a boy with severe growth and mental retardation, syndactyly of toes and facial anomalies. This phenotype can easily be classified in the group of craniodigital syndromes, but it is difficult to make a more clearly defined diagnosis, based on other minor anomalies, because of the presence of overlapping features. On the basis of various pathognomic features, we conclude that our patient could be an additional case of Filippi syndrome. Moreover, newly recognised features in this patient may be due to variability in phenotypic expression. 相似文献
63.
Lixian Zhang Peng Shi El‐Kebir Boukas Changhong Wang 《Optimal control applications & methods.》2006,27(5):273-291
In this paper, the problem of designing H∞ state‐feedback controllers for switched linear discrete‐time systems with polytopic uncertainties is investigated. Two approaches on designing robust and parameter‐dependent H∞ controllers are proposed and the existence conditions of the desired controllers are derived and formulated in terms of a set of linear matrix inequalities. By solving the corresponding convex optimization problem, the desired controllers are obtained, respectively, and different optimal H∞ noise‐attenuation level bounds of corresponding closed‐loop systems are given as well. The designed controllers have their own advantages and disadvantages regarding the conservatism and realization complexity. An illustrative example emerging in networked control systems (NCS) and numerical simulations are presented to show the applicability and effectiveness of the obtained theoretic results. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
64.
Anna Szymańska Elżbieta Korobowicz Wiesław Gołąbek 《European archives of oto-rhino-laryngology》2006,263(7):657-660
Nasopharyngeal angiofibromas occur predominantly in males in their puberty and adolescence; the incidence in other age groups and in women is exceptional. This report describes a case of a 57-year-old woman with nasopharyngeal angiofibroma presenting typical radiological findings in computed tomography, MR imaging and angiography. The tumour was successfully removed and histopathological examination confirmed the diagnosis. In 6 years follow-up the patient is free of symptoms. 相似文献
65.
O. H. Hishmat O. A. El-Shabrawy H. I. El Diwani N. M. Fawzy 《Archives of pharmacal research》1988,11(2):87-92
A number of substituted furodiketochroman derivatives (III a-f ) have been synthesized by fusion of aromatic aldehydes with 5-hydroxybergapten and 5-hydroxyisopimpinellin. On the other hand, when the reaction was carried out in a solvent, the corresponding bis-furocoumarin derivatives (IV c-n ) were obtained. The anticoagulant effect of compoundsIII a,b,d andIV b,c,f,g,i,k , was tested. They failed to demonstrate any significant effect. The effect of the tested compounds on the arterial blood pressure was studied. CompoundsIV c ,III d ,III b ,IV b ,IV g ,IV k andIV i showed lowering effects on the normal systolic blood pressure of anaesthetized rats in a decreasing manner. 相似文献
66.
M. El‐Batawy A. S. Zahran S. A. Madkor C. J. Smith 《Food and Agricultural Immunology》1993,5(1):57-60
An enzyme‐linked immunosorbent assay (ELISA) for the detection of porcine pepsin in milk‐clotting enzyme preparations has been developed. The assay is capable of detecting porcine pepsin in the range 1 μgto 1 mg ml‐1 without enhancement or modification. The specificity of the technique was studied by inhibition assay. Slight cross‐reactions with bovine rennet and Mucor miehei rennet occurred at high concentrations (1.0 mg ml‐1). The ELISA used in this investigation appears to provide a quick, sensitive and specific method for the detection of porcine pepsin and has potential applications in the dairy industry. 相似文献
67.
Sidi Mohammed El Amine Debbal 《Journal of medical engineering & technology》2020,44(7):396-410
Abstract Heart auscultation has been recognised for a long time as an important tool for the diagnosis of heart disease; it is the most common and widely recommended method to screen for structural abnormalities of the cardiovascular system. Detecting relevant characteristics and forming a diagnosis based on the sounds heard through a stethoscope, however, is a skill that can take years to be acquired and refine. The efficiency and accuracy of diagnosis based on heart sound auscultation can be improved considerably by using digital signal processing techniques to analyse phonocardiographic (PCG) signals. The study of the functioning of the heart is very important for the diagnosis of different cardiac pathologies. The phonocardiogram signal (PCG) is the signal generated after conversion of the sound noises coming from the heart into an electrical signal, it groups together a set of four cardiac noises (S1, S2, S3, S4) which are in direct correlation with cardiac activity. The short-term Fourier Transform (STFT) is an analytical technique that describes the evolution of the time and frequency behaviour of these four heart sounds. A statistical study has been carried out in this direction in order to better highlight the characteristics of the PCG signal. A fairly high number of cycles (twenty) was used to further refine the expected results. The objective of this paper is to use a statistical analysis based on the results obtained by the use of The STFT technic this in order to find statistical parameters (mean, standard deviation, etc.) which can give us a clear vision of the electrophysiological behaviour of the phonocardiogram signal. This aspect has not been done so far and which however can give appreciable practical results. 相似文献
68.
Mechanotransduction of bone cells<Emphasis Type="Italic">in vitro</Emphasis>: Mechanobiology of bone tissue 总被引:11,自引:0,他引:11
Mullender M El Haj AJ Yang Y van Duin MA Burger EH Klein-Nulend J 《Medical & biological engineering & computing》2004,42(1):14-21
Mechanical force plays an important role in the regulation of bone remodelling in intact bone and bone repair. In vitro, bone
cells demonstrate a high responsiveness to mechanical stimuli. Much debate exists regarding the critical components in the
load profile and whether different components, such as fluid shear, tension or compression, can influence cells in differing
ways. During dynamic loading of intact bone, fluid is pressed through the osteocyte canaliculi, and it has been demonstrated
that fluid shear stress stimulates osteocytes to produce signalling molecules. It is less clear how mechanical loads act on
mature osteoblasts present on the surface of cancellous or trabecular bone. Although tissue strain and fluid shear stress
both cause cell deformation, these stimuli could excite different signalling pathways. This is confirmed by our experimental
findings, in human bone cells, that strain applied through the substrate and fluid flow stimulate the release of signalling
molecules to varying extents. Nitric oxide and prostaglandin E2 values increased by between two- and nine-fold after treatment with pulsating fluid flow (0.6±0.3 Pa). Cyclic strain (1000
μstrain) stimulated the release of nitric oxide two-fold, but had no effect on prostaglandin E2. Furthermore, substrate strains enhanced the bone matrix protein collagen I two-fold, whereas fluid shear caused a 50% reduction
in collagen I. The relevance of these variations is discussed in relation to bone growth and remodelling. In applications
such as tissue engineering, both stimuli offer possibilities for enhancing bone cell growth in vitro. 相似文献
69.
Humphrey RK Beattie GM Lopez AD Bucay N King CC Firpo MT Rose-John S Hayek A 《Stem cells (Dayton, Ohio)》2004,22(4):522-530
70.
Skill NJ Griffin M El Nahas AM Sanai T Haylor JL Fisher M Jamie MF Mould NN Johnson TS 《Laboratory investigation; a journal of technical methods and pathology》2001,81(5):705-716
Diabetic nephropathy (DN) is characterized by an early, progressive expansion and sclerosis of the glomerular mesangium leading to glomerulosclerosis. This is associated with parallel fibrosis of the renal interstitium. In experimental renal scarring, the protein cross-linking enzyme, tissue transglutaminase (tTg), is up-regulated and externalized causing an increase in its crosslink product, epsilon-(gamma-glutamyl)-lysine, in the extracellular space. This potentially contributes to the extracellular matrix (ECM) accumulation central to tissue fibrosis by increasing deposition and inhibiting breakdown. We investigated if a similar mechanism may contribute to the ECM expansion characteristic of DN using the rat streptozotocin model over 120 days. Whole kidney epsilon-(gamma-glutamyl)-lysine (HPLC analysis) was significantly increased from Day 90 (+337%) and peaked at Day 120 (+650%) (p < 0.05). Immunofluorescence showed this increase to be predominantly extracellular in the peritubular interstitial space, but also in individual glomeruli. Total kidney transglutaminase (Tg) was not elevated. However, using a Tg in situ activity assay, increased Tg was detected in both the extracellular interstitial space and glomeruli by Day 60, with a maximal 53% increase at Day 120 (p < 0.05). Using a specific anti-tTg antibody, immunohistochemistry showed a similar increase in extracellular enzyme in the interstitium and glomeruli. To biochemically characterize glomerular changes, glomeruli were isolated by selective sieving. In line with whole kidney measurement, there was an increase in glomerular epsilon-(gamma-glutamyl) lysine (+361%); however, in the glomeruli this was associated with increases in Tg activity (+228%) and tTg antigen by Western blotting (+215%). Importantly, the ratio of glomerular epsilon-(gamma-glutamyl) lysine to hydroxyproline increased by 2.2-fold. In DN, changes in the kidney result in increased translocation of tTg to the extracellular environment where high Ca(2+) and low GTP levels allow its activation. In the tubulointerstitium this is independent of increased tTg production, but dependent in the glomerulus. This leads to excessive ECM cross-linking, contributing to the renal fibrosis characteristic of progressive DN. 相似文献