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1.
Kaposi's sarcoma. CT-radiographic correlation 总被引:1,自引:0,他引:1
The role of CT in the diagnosis of intrathoracic Kaposi's sarcoma (KS) was evaluated retrospectively in 24 patients, in the absence of coexistent opportunistic infections. In all cases the diagnosis of KS was initially established by histologic evaluation of extrathoracic disease: 15 patients had verified parenchymal KS and nine patients endobronchial KS. (Chest roentgenograms were analyzed separately for each group: in 14 patients serial films were available for review. The predominant radiographic findings was the presence of nonspecific, bilateral, perihilar infiltrates in 22 of 24 cases (92 percent). Corresponding CT scans documented the presence of abnormal hilar densities characteristically extending into the adjacent pulmonary parenchyma along distinctly perivascular and peribronchial pathways. Discrete, poorly marginated nodules were identified radiographically in ten cases (42 percent); these proved to be randomly distributed throughout the parenchyma on CT. Radiographic evidence of mediastinal adenopathy was distinctly unusual, seen in only two cases (8 percent). While CT typically demonstrated shotty adenopathy, significantly enlarged nodes (greater than 1 cm) were rarely identified. We concluded that CT is more specific than routine roentgenograms for identifying pulmonary KS. While not pathognomonic, peribronchial and perivascular disease is sufficiently characteristic to obviate more invasive diagnostic procedures, especially in patients with established KS. 相似文献
2.
用体外培养的人的伪表皮作为模型,进行药物毒理学作用的研究,观察了二甲亚砜(DMSO)在不同浓度和不同接触时间条件下,对人的伪表皮细胞脱氧核糖核酸(DNA)、核糖核酸(RNA)和蛋白质合成的影响:随着接触时间的延长,DNA、RNA和蛋白质合成均受抑制。低浓度条件下(1%),DNA、RNA和蛋白质合成增加;在15~50%浓度下,DNA和蛋白质合成抑制,而RNA合成仍增加;在高浓度条件下(70%~100%),DNA、RNA和蛋白质合成均明显抑制。 相似文献
3.
The authors made an analysis of the surgical methods in 94 cases of retinal detachment. In 36 cases it was a cerclage, in 44 an episcleral implant. In 8 patients invagination of the sclera was performed, in 3 photocoagulation as a separate intervention and in 3--cerclage with a simultaneous episcleral implant. Reattachment of the retina was achieved in 69.1% of cases. 相似文献
4.
The platelet membrane glycoprotein IIb-IIIa complex is essential for platelet aggregation and functions as a fibrinogen receptor on the activated platelet. When incorporated into phospholipid vesicles, this glycoprotein complex can function as an apparent calcium channel which facilitates the transit of calcium across a phospholipid barrier. In order to further evaluate this calcium channel, the effect of calcium channel blockers of the dihydropyridine (nifedipine and nicardipine), arylalkylamine (verapamil) and benzothiazepine (diltiazem) classes were evaluated on GPIIb-IIIa liposomes with encapsulated fura-2 (a fluorescent calcium indicator). Nicardipine, verapamil, and nifedipine significantly inhibited calcium influx into GPIIb-IIIa liposomes; however, this required 190 microM, 400 microM, and 140 microM drug, respectively. These concentrations are 10-1,000 fold greater than those clinically obtainable. In contrast, diltiazem at concentrations greater than 220 microM and amiloride at concentrations greater than 800 microM showed no inhibitory effects. When aspirinized platelets were activated with 30 micrograms/ml bovine fibrillar collagen, both nicardipine and diltiazem produced a decrease in both the initial rise and maximum cytoplasmic calcium concentration. Parallel experiments were performed to assess the effects of verapamil, nicardipine, and diltiazem on platelet aggregation in platelet rich plasma. Nicardipine, 190-380 microM, induced a prolongation of the lag phase, but no effect on the final degree of platelet aggregation to collagen. Similar inhibition of platelet aggregation was seen with diltiazem and verapamil although the effect of diltiazem was less pronounced particularly at higher concentrations of collagen. No effect was seen on aggregation with 32 microM ADP which is release independent, or on the primary wave of low dose ADP induced platelet aggregation.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Modelling spinal circuitry involved in locomotor pattern generation: insights from deletions during fictive locomotion 总被引:3,自引:3,他引:3
Ilya A. Rybak Natalia A. Shevtsova Myriam Lafreniere-Roula David A. McCrea 《The Journal of physiology》2006,577(2):617-639
The mammalian spinal cord contains a locomotor central pattern generator (CPG) that can produce alternating rhythmic activity of flexor and extensor motoneurones in the absence of rhythmic input and proprioceptive feedback. During such fictive locomotor activity in decerebrate cats, spontaneous omissions of activity occur simultaneously in multiple agonist motoneurone pools for a number of cycles. During these 'deletions', antagonist motoneurone pools usually become tonically active but may also continue to be rhythmic. The rhythmic activity that re-emerges following a deletion is often not phase shifted. This suggests that some neuronal mechanism can maintain the locomotor period when motoneurone activity fails. To account for these observations, a simplified computational model of the spinal circuitry has been developed in which the locomotor CPG consists of two levels: a half-centre rhythm generator (RG) and a pattern formation (PF) network, with reciprocal inhibitory interactions between antagonist neural populations at each level. The model represents a network of interacting neural populations with single interneurones and motoneurones described in the Hodgkin-Huxley style. The model reproduces the range of locomotor periods and phase durations observed during real locomotion in adult cats and permits independent control of the level of motoneurone activity and of step cycle timing. By altering the excitability of neural populations within the PF network, the model can reproduce deletions in which motoneurone activity fails but the phase of locomotor oscillations is maintained. The model also suggests criteria for the functional identification of spinal interneurones involved in the mammalian locomotor pattern generation. 相似文献
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Czarniak E Samet A Bronk M Rybak B Kochowska-Bronk M Zajac-Lenczewska I Ksiazek J Skokowski J 《Pneumonologia i alergologia polska》2003,71(1-2):31-35
The clinical specimens received from patients hospitalized in Department of Thoracic Surgery between 1997 and 2001 were microbiologically examined. The main specimen for microbiological examination was pleural fluid (median 34%). The frequency of specimens from bronchial tree increased significantly (from 4% to 26%) with concurrent decrease of sputum (from 29% to 6%). Among isolated pathogens, Gram negative rods were the most frequent (median 48%) and Pseudomonas sp. was the main pathogen among them. Occurrence of staphylococci was median 22% and Staphylococcus aureus, with a little decrease in analyzed period, was still the main Gram positive pathogen. Simultaneously the occurrence of MRSA in the last three years dropped three times. The number of isolations of yeasts have risen from 5.8% to 10.3%. 相似文献
10.
Telfer JF; Thomson AJ; Cameron IT; Greer IA; Norman JE 《Human reproduction (Oxford, England)》1997,12(10):2306-2312
Superoxide, an agent which attenuates the half-life of nitric oxide, is
metabolized and synthesized by superoxide dismutase (SOD) and xanthine
oxidase, respectively. Over the last few years much work has focused on the
role of nitric oxide in human parturition. The aim of this study was to
determine whether the onset of human parturition is associated with a
change in the expression of copper/zinc superoxide dismutase (Cu/Zn SOD),
manganese superoxide dismutase (Mn SOD) or xanthine oxidase within the
uterus. Samples of myometrium, placenta, decidua and fetal membranes were
obtained from women before and after the onset of labour at term.
Immunocytochemistry was used to localize Cu/Zn SOD, Mn SOD and xanthine
oxidase and measure SOD enzyme activity. Cu/Zn and Mn SOD-like
immunoreactivity was detected in syncytiotrophoblast cells, villous stromal
cells and endothelial cells of blood vessels in the placenta. In the
myometrium Cu/Zn and Mn SOD were localized to myocytes and endothelial
cells and to some vascular smooth muscle cells. In the fetal membranes we
observed staining for Cu/Zn SOD and Mn SOD in the amnion, chorion,
extravillous trophoblast and decidua. There was no difference in SOD enzyme
activity or staining intensity for SOD between different cell types before
and during labour. Xanthine oxidase immunoreactivity was identified in each
of the tissues examined and again there was no difference in immunostaining
in tissues obtained from women delivered before or after the onset of
labour. These results show that the pregnant uterus is capable of both
synthesizing and degrading superoxide and suggest that superoxide dismutase
and xanthine oxidase may play a role in the maintenance of uterine
quiescence during pregnancy, but not in the initiation of parturition.
相似文献