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The authors present the case of a 58-year-old woman. At presentation the patient complained of vertigo and noise in the ears with six months history, and from headache, accompanied by nausea and vomiting from three months. The physical examination of the patient found no abnormalities. The neurological examination revealed discoordination syndrome and mild hemiparesis of the left limbs. Computed tomography of the brain without and with contrast medium showed oval tumor, localized in the region of trigonum collaterale and the posterior horn of the right lateral ventricle. Operative intervention was performed after a preoperative management of the patient: transcortical fenestration of the brain in the region of trigonum collaterale and the posterior horn of the right lateral ventricle. The tumor was totally removed. It is well isolated, oval in shape, with feeding blood vessel from plexus chorioideus and was attached to the wall of the ventricle with several thin bridges. Macroscopically the tumor was 3 cm in diameter, with smooth walls, well capsulated, grey-brownish in color and with firm elastic consistence. The histological findings revealed meningioma--meningotheliomatose variant.  相似文献   
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A number of 5-nitrofuryl and 3-methoxy-2-nitrophenyl derivatives of 6 beta-aminopenicillanic (6 beta-APA), 7 beta-aminocephalosporanic (7 beta-ACA) and 7 beta-aminodesacetoxycephalosporanic (7 beta-ADCA) acids were synthesized by the method of mixed anhydrides or via Schiff bases. The chemical structures of the new compounds were confirmed by IR-, 1H-NMR and mass spectral data, obtained by negative ion electrospray ionization. The in vitro testing results indicated that all penicillins and cephalosporins prepared exhibited antibacterial activity equal to or in many cases considerably higher than those of ampicillin (CAS 69-53-4) and cephalexin (CAS 23325-78-2) against the Gram-positive microorganisms, excluding B. subtilis L2, B. subtilis HB2 and S. aureus 1/45 "Oxford". Their activity towards the two strains of Proteus mirabilis was also good being greater than that of cephalexin contrary to the demonstrated lower activity towards all strains of E. coli tested. The most active compounds which simultaneously possessed the broadest spectrum of antibacterial activity proved to be compounds 1 and 8 both bearing as a substituent a 5-nitrofuran group.  相似文献   
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This paper presents a methodology for three-dimensional (3D) computer modelling of the breast, using a combination of 3D geometrical primitives and voxel matrices that can be further subjected to simulated x-ray imaging, to produce synthetic mammograms. The breast phantom is a composite model of the breast and includes the breast surface, the duct system and terminal ductal lobular units. Cooper's ligaments, the pectoral muscle, the 3D mammographic background and breast abnormalities. A second analytical x-ray matter interaction modelling module is used to generate synthetic images from monoenergetic fan beams. Mammographic images of various synthesized breast models differing in size, shape and composition were produced. A preliminary qualitative assessment performed by three radiologists and a quantitative evaluation study using fractal and grey-level histogram analysis were conducted. A comparative study of extracted features with published data has also been performed. The evaluation results indicated good correlation of characteristics between synthetic and actual radiographs. Applications foreseen are not only in the area of breast imaging experimentation but also in education and training.  相似文献   
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Many aquatic vertebrates use mechano-sensory lateral lines to decipher water movements. The peripheral and central organization of the lateral line system has much in common with the auditory system. Therefore, it was hypothesized that the information processing of both systems could be related. Analogous to acoustic objects, for instance, object representations along the central lateral line pathway must be generated from patterns of particle motion across peripheral receivers. Thus, the lateral line offers insight into key features of neural computation beyond a specific sensory system. Here, central processing of water surface waves was described in the African clawed frog which depends on wave signals for prey detection, recognition and localization. Neural responses to surface wave stimuli were recorded in the brainstem and midbrain of Xenopus. A total of 109 units displayed either excitatory or inhibitory responses to surface waves. The response pattern distribution differed significantly across the optic tectum and torus semicircularis magnocellularis (chi-square test, P < 0.05). Stimulus frequencies from 10 to 40 Hz were represented equally across lateral line nuclei but best frequencies were systematically distributed along the rostrocaudal axis of the midbrain (chi-square test, P < 0.05). Forty-one percent of 102 widely distributed units phase locked significantly to stimulus frequencies (Rayleigh test, P < 0.05; vector strength > 0.3) and 41% of 39 tested units featured non-monotone rate-level functions. These neurones were registered mainly in the dorsal tectum and magnocellular torus semicircularis (chi-square test, P < 0.05). Across all tested nuclei, 16 of 17 discreetly distributed units showed a directional response to spatial stimulation. The results suggest midbrain subdivisions with respect to processing of stimulus timing, frequency and amplitude.  相似文献   
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Purpose The purpose of the present study was to investigate the effects of phenothiazines (at clinically relevant doses) on the viability and proliferation of leukemic cell lines and normal lymphocytes, and to investigate the possibility of specific induction of apoptosis in leukemic cells.Methods Phenothiazines with different chemical structure and hydrophobicity were used: chlorpromazine (CPZ); levomepromazine (LVPZ); prometazine (PMZ); trifluoperazine (TFPZ); thioridazine (TRDZ). The leukemic cell lines used were: Daudi and Raji (derived from Burkitts lymphoma), K-562 (derived from myelogenous leukemia), and BALL-1, MOLT-4, HPB-ALL and CCRF-HSB-2 (derived from acute lymphoblastic leukemia). The cytotoxicity of the phenothiazines was determined by a CellTiter-Glo luminescent cell viability assay, using ATP bioluminescence as a marker of cell viability as well as a marker of mitochondrial activity. The proliferation of leukemic cells was determined using a CellTiter-AQ cell proliferation assay which is based on the reduction of a methyl-tetrazolium compound to the formazan product. Apoptosis induction was estimated using phosphatidylserine (PSer) translocation to the cell surface and DNA fragmentation as characteristics of the process.Results Phenothiazines (at concentrations in the range 0.1–10 M) did not affect the viability of normal lymphocytes during a 24-h incubation. Moreover, about 15–20% increase in ATP bioluminescence was observed in normal cells during treatment with 40 M phenothiazines. In contrast, the phenothiazines manifested strong cytotoxicity and antiproliferative activity against leukemic cells. The most powerful drugs were TFPZ and TRDZ, followed by CPZ. They showed a significant cytotoxic effect against leukemic cells even at 5–10 M. The most sensitive cell lines were MOLT-4 and Raji, and the most resistant were HPB-ALL and CCRF-HSB-2. All phenothiazines induced PSer exposure on the surface of leukemic cells, but not of normal lymphocytes. TFPZ, TRDZ and CPZ also induced DNA fragmentation in almost all leukemic cell lines during a 48-h incubation. The strongest apoptotic agent was TRDZ. The apoptosis induction was not accompanied by a significant release of cytochrome c from the mitochondria into the cytoplasm of native cells. Moreover, the drugs markedly suppressed Ca2+-induced cytochrome c release in isolated mitochondria of leukemic cells.Conclusions The results suggest that in clinically relevant doses (up to 20 M) some phenothiazines (TFPZ, TRDZ, CPZ) expressed a selective cytotoxicity and antiproliferative activity, and induced apoptosis in leukemic cells without any influence on the viability of normal lymphocytes. It is considered that the mechanism of apoptosis induction in phenothiazine-treated leukemic cells is associated with inhibition of mitochondrial DNA polymerase and decreased ATP production, which are crucial events for the viability of cancer cells.Abbreviations CPZ Chlorpromazine - LVPZ Levomepromazine - PBS(–) Phosphate-buffered saline (Ca2+- and Mg2+-free) - PMZ Prometazine - PSer Phosphatidylserine - ROS Reactive oxygen species - TFPZ Trifluoperazine - TRDZ Thioridazine  相似文献   
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Medical ethics     
Bliznakov EG 《Lancet》2000,356(9240):1522
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Summary. The studies reported here indicate that the sheep red blood cell surface can be modified with poly-L-lysyl gelatin, and such changes can be monitored by the technique of microelectrophoresis. When these cells are injected into mice, enhanced levels of hemolytic antibody are obtained over control unmodified cells for the primary, early, and late secondary responses. Although the experiments were designed primarily to demonstrate the phenomena, rather then to determine the mechanism, it seems unlikely that the enhancement is due to physical modification of the antigen.  相似文献   
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