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21.
A patient with severe aortic insufficiency due to fenestration of the non-coronary aortic valve leaflet is described. A preoperative echocardiogram demonstrated early closure of the mitral valve and early diastolic separation of the aortic valve leaflets. These findings disappeared after partial surgical correction and subsequent hemodynamic improvement. Premature opening of the aortic valve is common in severe aortic insufficiency. 相似文献
22.
Variations in the β-carotene, vitamin C and vitamin E content of D. tertiolecta have been shown to result from the nitrogen source used in the culture medium. Differences of 101%, 38% and 69% have been found in β-carotene, ascorbic acid and tocopherol content in mg/g of dry matter, respectively, and differences of 147%, 63% and 37% occurred in β-carotene, vitamin C and E concentrations in mg/litre of culture, respectively. Considering the β-carotene, vitamin C and vitamin E content in mg/g of chlorophyll a, maximum variations occurred in β-carotene content, with differences of 145% among the different nitrogen sources. Maximum β-carotene and vitamin C values were found in urea cultures, whereas urea cultures showed the minimum values for vitamin E. 相似文献
23.
Mesoplodon peruvianus , a new species of beaked whale, is described on the basis of ten specimens which have either stranded or been captured between 11°12'S and 15°19'S latitude along the coasts of the provinces of Lima and Ica, south central Peru. This is the thirteenth living species of Mesoplodon recognized in the world's oceans. The animals that were examined were uniformly gray above, shading to lighter gray below. This whale is the smallest species of Mesoplodon (maximum body length 3.72 m) and is characterized by its teeth, which are small (31 to 65 mm long), ovate in cross section, and positioned 2.5% to 8.4% of the mandibular length from the anterior extremity, and posterior to the mandibular symphysis. 相似文献
24.
25.
Julio Fernández Pardal Enri Borda Martha F. Gimeno Alvaro L. Gimeno 《Life sciences》1981,29(15):1583-1589
The spontaneous 3H-noradrenaline efflux from the isolated epididymal and prostatic portions of the rat vas deferens, was investigated. The spontaneous tritium efflux was higher in the epididymal portion than in the prostatic one from normal animals. Such differences were abolished after castration. On the other hand, acetylsalicylic acid enhanced the total tritium efflux only in the epididymal portion, whereas phentolamine and phenoxybenzamine increased the total tritium efflux from the two portions of the rat vas deferens in both experimental groups. The prostatic portion released a similar amount of 3H normetanephrine than the apididymal end, whereas other metabolic fractions (3,4-dihydroxyphenylglycol; 3,4-dihydroxymandelic acid and O-methylated deaminated metabolites) were smaller in the prostatic portion in comparison with the epididymal portion from control vas deferens. The results presented in the isolated rat vas deferens suggest the existence of a prostaglandin as well as an alpha adrenoceptive modulation of the spontaneous total tritium efflux. 相似文献
26.
Gene expression in normal and virally transformed mouse 3T3B and hamster BHK21 cells 总被引:8,自引:0,他引:8
Cell lines 3T3B (mouse), 3T3B-SV40, BHK21 (hamster) and BHK21 polyoma virus (PyY) were labelled with [35S]methionine under conditions in which 500–600 cpm were incorporated per cell during a 20 h incubation period. Two-dimensional gel electrophoresis analysis of the total [35S]methionine-labelled polypeptides from 200–300 cells followed by fluorography revealed about 500 acidic (isoelectric focusing, IEF) and 150 basic polypeptides (non-equilibrium pH gradient electrophoresis, NEPHGE) whose position could be reproducibly assessed. Counting of 33 abundant acidic polypeptides present in both 3T3B and 3T3B-SV40 revealed significant changes in the relative proportion of ten of them. Seven, including the subunit of the 100 Å filaments ‘fibroblast type’ (55K) (1.1% in 3T3B; 0.6% in 3T3B-SV40), three cytoarchitectural proteins and three soluble proteins, corresponded to a decrease of 40% or more in the radioactivity of the spots in transformed cells, and only in three cases was there a significant increase in radioactivity of polypeptides in 3T3B-SV40 cells. Among the polypeptides that show less than 40% variation we have identified total actin (42K) (13% of total label in 3T3B; 10% in 3T3B-SV40), α- and β-tubulin (55K) (1.6% of total label in 3T3B; 2% in 3T3B-SV40), eleven polypeptides present in Triton skeletons, and nine soluble proteins. We have also observed 25 obvious changes in polypeptide intensities (16 acidic and 9 basic) but these were not quantitated. Only three polypeptides were found in transformed cells that were not detected in normal cells. One of these corresponded to the large T antigen and the other two to Triton-soluble proteins of a molecular weight in the range of 52–54K. Similar quantitative studies on the hamster BHK21/BHK21PyY pair confirmed at least the major observations made in 3T3B and 3T3B-SV40. 相似文献
27.
Photosynthetic fructose-1,6-diphosphatase (FDPase) fractions I and II, earlier purified from spinach leaves, show a similar amino acid composition, with the exception of a higher glutamic acid content in the latter. In both fractions glutamic and aspartic acids are the main amino acids. pH activity profiles of fractions I and II are similar, with optima at 8·65–8·70, both showing a high specificity for fructose- 1,6-diphosphate. These two fractions are Mg2+-dependent for activity, with an Optimum Mg2+ concentration of 10 mM in standard conditions, which shifts to 5 mM when the MG2+/EDTA ratio is increased to 10; Mn2+ and Co2+ are slightly active. EDTA enhances FDPase activity slightly, with an optimum at 0·4–0·8 mM. Cysteine has no activating effect, and acts as an inhibitor above 10 mM. Both I and II have an optimum substrate concentration of 4 mM, and the substrate inhibits at concns above this value. Kinetic velocity curves are sigmoidal, with the concave zone located in the range of physiological substrate concns. (Hill coefficient 1·75 for both). This suggests a strong regulatory role of fructose-1,6-diphosphate. Km values are 1·4 × 10−3 M (fraction I) and 1·1 × 10−3 M (fraction II). The highest activity rate occurs at 60°, in accordance with the high thermostability of both fractions; the activation energies are 14·3 kcal/mol (fraction I) and 13·0 kcal/mol (fraction II). 相似文献
28.
Jiwen Liu Zice Fu An-Rong Li Michael Johnson Liusheng Zhu Andrew Marcus Jay Danao Tim Sullivan George Tonn Tassie Collins Julio Medina 《Bioorganic & medicinal chemistry letters》2009,19(17):5114-5118
The evaluation of the CXCR3 antagonist AMG 487 in clinic trials was complicated due to the formation of an active metabolite. In this Letter, we will discuss the further optimization of the quinazolinone series that led to the discovery of compounds devoid of the formation of the active metabolite that was seen with AMG 487. In addition, these compounds also feature increased potency and good pharmacokinetic properties. We will also discuss the efficacy of the lead compound 34 in a mouse model of cellular recruitment induced by bleomycin. 相似文献
29.
Cytoskeleton proteins are substrates for proteases and further apoptotic death. We evaluated the participation of cytoskeleton
in morphological changes during cell death induced by two apoptotic conditions, potassium deprivation (K5) and staurosporine,
in cerebellar granule neurons (CGC). We found that K5 induced somatic damage, but neurites were relatively preserved, which
corresponded to the reorganization of actin and α-tubulin in neurites. Staurosporine (STS) induced an early alteration of
neurites with reorganization of cytoskeleton proteins in somas. Caspase inhibitor ZVAD totally inhibited STS-induced α-tubulin
reorganization and partially blocked STS-induced actin reorganization. α-tubulin and actin reorganization induced by K5 was
affected by ZVAD. Calpain inhibitor (IC1) did not affect α-tubulin or actin reorganization induced by STS, K5 or ionomycin.
Neither ZVAD, nor IC1 changed α-tubulin or actin levels upon K5 treatment. STS increased α-tubulin and actin levels, but neither
ZVAD nor IC1 changed α-tubulin levels upon STS treatment. In contrast, ZVAD reduced the STS-induced increase of actin. These
results suggest that CGC cytoskeleton proteins undergo a differential expression and reorganization depending on the apoptotic
condition. 相似文献
30.
Rojas P Garduño B Rojas C Vigueras RM Rojas-Castañeda J Rios C Serrano-Garcia N 《Neurochemical research》2001,26(11):1245-1251
EGb761 has been suggested to be an antioxidant and free radical scavenger. Excess generation of free radicals, leading to lipid peroxidation (LP), has been proposed to play a role in the damage to striatal neurons induced by 1-methyl-4-phenylpyridinium (MPP+). We investigated the effects of EGb761 pretreatment on MPP+ neurotoxicity. C-57 black mice were pretreated with EGb761 for 17 days at different doses (0.63, 1.25, 2.5, 5 or 10 mg/kg) followed by administration of MPP+, (0.18, 0.36 or 0.72 mg/kg). LP was analyzed in corpus striatum at 30 min, 1 h, 2 h and 24 h after MPP+ administration. Striatal dopamine content was analyzed by HPLC at the highest EGb761 dose at 2 h and 24 h after MPP+ administration. MPP+-induced LP was blocked (100%) by EGb761 (10 mg/kg). Pretreatment with EGb761 partially prevented (32%) the dopamine-depleting effect of MPP+ at 24 h. These results suggest that supplements of EGb761 may be effective at preventing MPP+-induced oxidative stress. 相似文献