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61.
The mode of inhibitory action of Zataria multiflora Boiss. essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The EO at concentrations used in this study suppressed the size of the colony as well as sporulation. SEM of mycelia treated with given concentrations of EO showed morphological alterations ranging from loss of turgidity and uniformity of mycelia at low concentrations of EO to evident destruction of the hyphae at higher concentration of EO. Semi-thin sections of mycelia exposed to different concentrations of EO were analysed by light microscopy and revealed that the major change at level as low as 50 ppm of EO was limited to vacuolisation of cytoplasm resulting in cell swelling, while at higher concentrations, detachment of the cell membrane from the cell wall, deformation of mycelia and shedding the cytoplasm from the cell were the main alterations. These damages were well documented by TEM, which showed that the main sites of action of EO were the plasma membrane and cell wall. In conclusion, morphological and structural changes observed in this study may be one of the mechanisms involved in growth inhibition of the fungi and reducing aflatoxin production. 相似文献
62.
PURPOSE: We evaluated the frequency and features of extraosseous bone formation in the kidneys of patients undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: Percutaneous nephrolithotomy was performed in 621 patients at our institution between 1997 and 2006. In 21 cases metaplastic bone arising from the urothelium was observed. Clinical, radiographic and histopathological features of this group were studied in detail. RESULTS: Patient age ranged from 7 to 40 years (median 11). Extraosseous bone formation was identified in 7 right (33%) and 14 left (67%) kidneys. In all cases extraosseous bone was identified at the angle of the pelvis and ureter, just proximal to the ureteropelvic junction. The typical radiographic appearance of a radiopaque eccentric halo surrounding an area of lesser radiological density connected with the urothelium was seen in 10 of 13 radiographs (77%). Histopathological evaluation showed well formed trabecular bone with surface osteoblastic activity, areas of intratrabecular adipose bone marrow and hematopoietic cells in 5 cases (24%); woven bone intimately related to trabecular bone with scattered hematopoietic cells in 14 (67%); and entirely woven bone with associated mineral deposits and prominent fibroblastic proliferation in 2 (10%). CONCLUSIONS: Although rarely reported in the literature, metaplastic bone formation in the renal pelvis was seen relatively frequently in our patient population. The pathogenesis of this phenomenon is not clearly understood. Recognition of extraosseous bone is important, since it has implications for management and prognosis. In-depth studies of this phenomenon are required to arrive at any conclusions regarding its etiology. 相似文献
63.
Tardive dyskinesia (TD), a syndrome of involuntary hyperkinesias in the orofacial region that develops in patients chronically treated with neuroleptic agents is a major limitation of the therapy. Rats chronically treated with haloperidol exhibit vacuous chewing movements (VCMs) with the twitching of facial musculature and tongue protrusion. The syndrome is widely used as an animal model of TD. Evidence suggests a role of 5-hydroxytryptamine (5-HT; serotonin)-1A receptors in the pathogenesis and treatment of TD because repeated administration of haloperidol resulted in an increase in the effectiveness of 5-HT-1A receptors while drugs with agonist activity at 5-HT-1A receptors could attenuate haloperidol-induced VCMs. The present study was designed to test the hypothesis that a decrease in the responsiveness of somatodendritic 5-HT-1A receptors by the coadministration of buspirone could reverse the induction of VCMs and supersensitivity at 5-HT-1A receptors by haloperidol. Rats treated with haloperidol at a dose of 1 mg/kg twice a day for 2 weeks displayed VCMs with twitching of facial musculature that increased in a time dependent manner as the treatment continued to 5 weeks. Coadministration of buspirone attenuated haloperidol-induced VCMs after 2 weeks and completely prevented it after 5 weeks. The intensity of 8-hydroxy-2-di (n-propylamino) tetralin (8-OH-DPAT)-induced locomotion was greater in saline+haloperidol injected animals but not in buspirone+haloperidol injected animals. 8-OH-DPAT-induced decreases of 5-HT metabolism were greater in saline+haloperidol injected animals but not in buspirone+haloperidol injected animals. It is suggested that an impaired somatodendritic 5-HT-1A receptor dependent response is a major contributing factor in the pathophysiology of TD and a normalization of the somatodendritic response by drugs may help extending therapeutics in schizophrenia. 相似文献
64.
Intelligent optimal control with dynamic neural networks. 总被引:2,自引:0,他引:2
The application of neural networks technology to dynamic system control has been constrained by the non-dynamic nature of popular network architectures. Many of difficulties are-large network sizes (i.e. curse of dimensionality), long training times, etc. These problems can be overcome with dynamic neural networks (DNN).In this study, intelligent optimal control problem is considered as a nonlinear optimization with dynamic equality constraints, and DNN as a control trajectory priming system. The resulting algorithm operates as an auto-trainer for DNN (a self-learning structure) and generates optimal feed-forward control trajectories in a significantly smaller number of iterations. In this way, optimal control trajectories are encapsulated and generalized by DNN. The time varying optimal feedback gains are also generated along the trajectory as byproducts. Speeding up trajectory calculations opens up avenues for real-time intelligent optimal control with virtual global feedback.We used direct-descent-curvature algorithm with some modifications (we called modified-descend-controller-MDC algorithm) for the optimal control computations. The algorithm has generated numerically very robust solutions with respect to conjugate points. The adjoint theory has been used in the training of DNN which is considered as a quasi-linear dynamic system. The updating of weights (identification of parameters) are based on Broyden-Fletcher-Goldfarb-Shanno BFGS method. Simulation results are given for an intelligent optimal control system controlling a difficult nonlinear second-order system using fully connected three-neuron DNN. 相似文献
65.
Abdul Samad K Prasanna MK Akhar AP 《Indian journal of dermatology, venereology and leprology》2002,68(4):225-226
Sezary syndrome (SS), is described as the classical triad of pruritic erythroderma, lymphadenopathy, and presence of more than 10% of circulating Sezary cells in the peripheral blood. We report on unusual case of advanced cutaneous T - cell lymphoma with classical haematological and histopathological features of Sezary syndrome, but lacking the clinical features of erythroderma. A 66 year old man presented with asymptomatic multiple papules, plaques and nodules and with generalized lymphadenopathy. Peripheral smear showed more than 60% of Sezary cells. Skin and lymph node biopsy showed typical features of T-cell lymphoma and immunohistochemistry and CD marker studies showed the cells to be atypical T-lymphocytes. This unusual case is highlighted to denote that erythroderma need not be taken as a hard and fast criterion for diagnosing Sezary syndrome. 相似文献
66.
Liposomal drug delivery systems: an update review 总被引:3,自引:0,他引:3
The discovery of liposome or lipid vesicle emerged from self forming enclosed lipid bi-layer upon hydration; liposome drug delivery systems have played a significant role in formulation of potent drug to improve therapeutics. Recently the liposome formulations are targeted to reduce toxicity and increase accumulation at the target site. There are several new methods of liposome preparation based on lipid drug interaction and liposome disposition mechanism including the inhibition of rapid clearance of liposome by controlling particle size, charge and surface hydration. Most clinical applications of liposomal drug delivery are targeting to tissue with or without expression of target recognition molecules on lipid membrane. The liposomes are characterized with respect to physical, chemical and biological parameters. The sizing of liposome is also critical parameter which helps characterize the liposome which is usually performed by sequential extrusion at relatively low pressure through polycarbonate membrane (PCM). This mode of drug delivery lends more safety and efficacy to administration of several classes of drugs like antiviral, antifungal, antimicrobial, vaccines, anti-tubercular drugs and gene therapeutics. Present applications of the liposomes are in the immunology, dermatology, vaccine adjuvant, eye disorders, brain targeting, infective disease and in tumour therapy. The new developments in this field are the specific binding properties of a drug-carrying liposome to a target cell such as a tumor cell and specific molecules in the body (antibodies, proteins, peptides etc.); stealth liposomes which are especially being used as carriers for hydrophilic (water soluble) anticancer drugs like doxorubicin, mitoxantrone; and bisphosphonate-liposome mediated depletion of macrophages. This review would be a help to the researchers working in the area of liposomal drug delivery. 相似文献
67.
Diversity of expression of the sensory neuron-specific TTX-resistant voltage-gated sodium ion channels SNS and SNS2 总被引:8,自引:0,他引:8
Amaya F Decosterd I Samad TA Plumpton C Tate S Mannion RJ Costigan M Woolf CJ 《Molecular and cellular neurosciences》2000,15(4):331-342
The differential distribution of two tetrodotoxin resistant (TTXr) voltage-gated sodium channels SNS (PN3) and SNS2 (NaN) in rat primary sensory neurons has been investigated. Both channels are sensory neuron specific with SNS2 restricted entirely to those small dorsal root ganglion (DRG) cells with unmyelinated axons (C-fibers). SNS, in contrast, is expressed both in small C-fiber DRG cells and in 10% of cells with myelinated axons (A-fibers). All SNS expressing A-fiber cells are Trk-A positive and many express the vanilloid-like receptor VRL1. About half of C-fiber DRG neurons express either SNS or SNS2, and in most, the channels are colocalized. SNS and SNS2 are found both in NGF-responsive and GDNF-responsive C-fibers and many of these cells also express the capsaicin receptor VR1. A very small proportion of small DRG cells express either only SNS or only SNS2. At least four different classes of A- and C-fiber DRG neurons exist, therefore, with respect to expression of these sodium channels. 相似文献
68.
Goldberg RJ Samad NA Yarzebski J Gurwitz J Bigelow C Gore JM 《The New England journal of medicine》1999,340(15):1162-1168
BACKGROUND: Limited information is available on trends in the incidence of and mortality due to cardiogenic shock complicating acute myocardial infarction. We studied the incidence of cardiogenic shock complicating acute myocardial infarction and in-hospital death rates among patients with this condition in a single community from 1975 through 1997. METHODS: We conducted an observational study of 9076 residents of metropolitan Worcester, Massachusetts, who were hospitalized with confirmed acute myocardial infarction in all local hospitals during 11 one-year periods between 1975 and 1997. Our study included periods before and after the advent of reperfusion therapy. RESULTS: The incidence of cardiogenic shock remained relatively stable over time, averaging 7.1 percent among patients with acute myocardial infarction. The results of a multivariable regression analysis indicated that the patients hospitalized during recent study years were not at a substantially lower risk for shock than patients hospitalized in the mid-to-late 1970s. Patients in whom cardiogenic shock developed had a significantly greater risk of dying during hospitalization (71.7 percent) than those who did not have cardiogenic shock (12.0 percent, P<0.001). A significant trend toward an increase in in-hospital survival among patients with cardiogenic shock in the mid-to-late 1990s was found in crude and adjusted analyses. CONCLUSIONS: Our findings indicate no significant change in the incidence of cardiogenic shock complicating acute myocardial infarction over a 23-year period. However, the short-term survival rate has increased in recent years at the same time as the use of coronary reperfusion strategies has increased. 相似文献
69.
Type I choledochal cysts were diagnosed on ultrasonography in 14 patients. The cysts were seen as oval or fusiform anechoic structures located in the subhepatic space and separate from the gallbladder. The continuity of the cyst with the bile duct in the porta hepatis was a specific feature for correct diagnosis of the condition. 相似文献
70.
OBJECTIVE: To determine the predictive value of flow-mediated vasodilation (FMD) compared with angina pectoris, exercise electrocardiography, and myocardial perfusion imaging (MPI). METHODS: This study was carried out in Shahid Madani Heart Center, Tabriz, Iran from April 2004 to September 2006. A total of 92 patients with chest pain syndrome were enrolled in this study. Using high resolution ultrasound system endothelial function was evaluated, and the result of the flow-mediated dilation (FMD%) was defined as the percent change in the internal diameter of the brachial artery during reactive hyperemia related to baseline. RESULTS: Coronary artery disease (CAD) was documented in 77 (83.7%) patients. The percentage of FMD was lower in patients with CAD compared with those +/- 4.61, p=0.001). In comparison with typical anginal chest pain (sensitivity 46.7%, specificity 80%), exercise stress test (sensitivity 75%, specificity 60%), and MPI (sensitivity 96.5, specificity 55.6%) the receiver operator characteristic curve showed the percentage FMD optimal cut-off value as =7.41 with a sensitivity of 87.0%, specificity of 66.7%, negative predictive value of 93.0%, and positive predictive value of 50%. CONCLUSION: In patients with chest pain syndrome, the FMD is a sensitive indicator of CAD with moderate specificity that is unable to predict accurately the extent and severity of it. 相似文献