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排序方式: 共有389条查询结果,搜索用时 11 毫秒
91.
Localization of surface vWF on resting and stimulated platelets 总被引:1,自引:0,他引:1
We used immunoelectron microscopic localization techniques to investigate whether platelets stimulated by ADP or ristocetin in the plasma milieu bind von Willebrand factor (vWF) to their surfaces. We found by both peroxidase- and ferritin-based methods that unstimulated platelets lack vWF on their surfaces, whereas platelets that are stimulated with ADP or ristocetin have vWF associated with their surfaces. The specificity of the findings was confirmed by absorption studies using severe von Willebrand disease (vWD) and hemophilic plasmas. The anti-vWF antibodies were blocked by incubation with hemophilic plasma but not by incubation with severe vWD plasma. Thus, in the plasma environment, in the presence of fibrinogen, vWF becomes associated with the platelet surface subsequent to stimulation with ADP or ristocetin. 相似文献
92.
LE Almaguer‐Mederos NS Falcón YR Almira YG Zaldivar DC Almarales EM Góngora MP Herrera KE Batallán RR Armiñán MV Manresa GS Cruz J Laffita‐Mesa TM Cyuz V Chang G Auburger S Gispert LV Pérez 《Clinical genetics》2010,78(2):169-174
Almaguer‐Mederosa LE, Falcón NS, Almira YR, Zaldivar YG, Almarales DC, Góngora EM, Herrera MP, Batallán KE, Armiñán RR, Manresa MV, Cruz GS, Laffita‐Mesa J, Cyuz TM, Chang V, Auburger G, Gispert S, Pérez LV. Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis. Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32–79 units. Using a Kaplan–Meier survival analysis, we obtained cumulative probability curves for disease manifestation at a particular age for each CAG repeat length in the 34–45 range. These curves were significantly different (p < 0.001) and showed small overlap. All these information may be very valuable in predictive‐testing programs, in the planning of studies for the identification of other genetic and environmental factors as modifiers of age at onset, and in the design of clinical trials for people at enlarged risk for SCA2. 相似文献
93.
Nathan DM美 Buse JB美 Davidson MB美 Ferrannini E意大利 Holman RR英 Sherwin R美 Zinman B加拿大 钱荣立 《中华糖尿病杂志》2009,17(1):75-77
在不到一年时间由同一批专家代表ADA和EASD先后起草和发布了两次关于“2型糖尿病高血糖处理的共识声明”同时发表在2008年1月和12月的《DiabetesCare》和《Diabetologia》上。第一次共识声明内容主要围绕TZDs药物的安全性,本刊作了摘译转载(参阅《中国糖尿病杂志22008年第7期)。第二次修订的共识声明,关注点为降糖药的新分级,论据及观点比较清晰,故仍摘译供读者参考。 相似文献
94.
M-J Castro AH Stam C Lemos B de Vries KRJ Vanmolkot J Barros GM Terwindt RR Frants J Sequeiros MD Ferrari JM Pereira-Monteiro & AMJM van den Maagdenberg 《Cephalalgia : an international journal of headache》2009,29(3):308-313
Almost all mutations in the SCN1A gene, encoding the α1 subunit of neuronal voltage-gated NaV 1.1 sodium channels, are associated with severe childhood epilepsy. Recently, two mutations were identified in patients with pure familial hemiplegic migraine (FHM). Here, we identified a novel SCN1A L263V mutation in a Portuguese family with partly co-segregating hemiplegic migraine and epilepsy. The L263V mutation segregated in five FHM patients, three of whom also had epileptic attacks, occurring independently from their hemiplegic migraine attacks. L263V is the first SCN1A mutation associated with FHM and co-occurring epilepsy in multiple mutation carriers, and is the clearest molecular link between migraine and epilepsy thus far. The results extend the clinical spectrum associated with SCN1A mutations and further strengthen the molecular evidence that FHM and epilepsy share, at least in part, similar molecular pathways. 相似文献
95.
96.
Characterization of four N-3-thymidine adducts formed in vitro by the reaction of thymidine and butadiene monoxide 总被引:1,自引:0,他引:1
Four products were characterized from the reaction of thymidine with
butadiene monoxide (BM), a known human mutagen and possible human
carcinogen. These products were purified by HPLC and characterized as
diastereomeric pairs of N-3-(1-hydroxy-3-buten-2-yl)thymidine and N-3-
(2-hydroxy-3-buten-1-yl)thymidine based upon their UV spectra, 1H NMR and
fast atom bombardment mass spectra. Incubation of thymidine with an excess
of BM at pH 7.4 and 37 degrees C allowed calculation of the
pseudo-first-order kinetic rate constants for the adduct formation, but
when these rate constants were compared with the rates we previously
determined with guanosine, adenosine and deoxycytidine, the results
suggested a lower reactivity with thymidine in comparison with the other
nucleosides. When incubations were carried out at lower BM concentrations,
the formation of adducts appeared to be linearly dependent on BM
concentration. The four thymidine adducts were completely stable for 1 week
when incubated at 37 degrees C in pH 7.4 phosphate buffer. These results
suggest that the interactions of BM with thymidine may play a role in the
molecular mechanisms of mutagenesis and carcinogenesis of BM.
相似文献
97.
98.
Simeone JF; Edelman RR; Stark DD; Wittenberg J; White EM; Butch RJ; Mueller PR; Brady TJ; Ferrucci JT Jr 《Radiology》1985,157(2):437-441
Eight healthy volunteers and 11 patients with pancreatic abnormalities were studied using a conventional body coil and a prototype magnetic resonance (MR) surface coil. Final pathologic diagnoses included carcinoma of the head (six), body (one), and tail of the pancreas (two) and chronic pancreatitis (two). In surface coil images of the volunteers, the body and tail of the pancreas was visualized in all cases but one, and the pancreatic duct was seen in five of eight cases. In-plane spatial resolution of 0.9 X 0.9 mm and 5-mm section thickness was obtained. At the same time, pancreatic surface coil images had a twofold improvement in the signal-to-noise ratio (SNR) compared with body coil images. T1-weighted spin-echo images gave greater SNR, reduced motion artifacts, provided superior anatomic detail, and offered more diagnostic information than comparable T2-weighted images. Significant abnormalities detected only by surface coil imaging included a small tumor surrounded by reactive edema and periglandular tumor invasion. This study demonstrates that surface coil imaging of the pancreas not only is feasible but provides an improved method for examining the pancreas by MR. 相似文献
99.
100.
Plasma-derived vitamin D binding protein (DBP) is an important physiologic regulator of the neutrophil chemotactic response to activated complement. A cell-associated form of DBP has been observed in numerous cell types. We now report that mature, circulating human neutrophils also contain cell-associated DBP. Immunofluorescence studies of normal untreated neutrophils showed the presence of DBP on the cell surface. Western blotting of detergent-soluble neutrophil lysates with a polyclonal anti-DBP showed two major immunoreactive bands, one with an apparent molecular weight of 56 Kd (identical to purified plasma-derived DBP) and a second less prominent band at 12 to 14 Kd. Quantitation of the immunoreactive bands by video densitometry indicated that normal human neutrophils contain 1.5 +/- 0.8 ng DBP/10(6) cells (n = 9). Immunoprecipitation of detergent-soluble lysates with the polyclonal anti-DBP showed only the 56-Kd form by Western blotting. In contrast, a monoclonal anti-DBP immunoprecipitated the 12 to 14 Kd form of DBP from lysates of surface-radioiodinated cells. Western blots of subcellular fractions showed that immunoreactive bands were found in the specific (secondary) granule and plasma-membrane fractions. In addition, pretreatment of neutrophils with 10 nmol/L phorbol myristate acetate (PMA) resulted in approximately a 50% reduction in the amount of DBP in both the specific granule and plasma-membrane fractions. Finally, analysis of the cell- free supernates showed that DBP was spontaneously released into the extracellular milieu: moreover, this release was enhanced if the cells were first stimulated with C5a, formyl-norleucyl-leucyl-phenylalanine (fNLP) or PMA. 相似文献