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101.
了解TGFβ1基因对血管内皮细胞表达细胞外基质蛋白及与基质黏附力的影响。用DOTAP脂质体转染p MAMneo TGFβ1于原代培养的脐静脉内皮细胞,经G4 18筛选,TGFβ1表达经免疫荧光鉴定。Western blot确定 型胶原、纤黏连蛋白的表达,微管吸吮系统确定内皮细胞与基质的黏附力。结果表明生理情况下的内皮细胞能表达少量的TGFβ1及胶原、纤黏连蛋白。经G4 18筛选,外源性TGFβ1在血管内皮细胞中稳定表达,能显著提高胶原、纤黏连蛋白纤维的表达及细胞与基质的黏附。说明TGFβ1在血管组织工程中促进内皮细胞的黏附具有一定的应用价值。 相似文献
102.
Matsumoto N Asano M Ogura Y Takenouchi-Ohkubo N Chihaya H Chung-Hsing W Ishikawa K Zhu L Moro I 《Scandinavian journal of immunology》2003,58(4):471-476
Using a recombinant vaccinia virus containing the T7 RNA polymerase, we have established a system for the transient expression of human polymeric immunoglobulin receptor (pIgR) in baby hamster kidney cells, a baby hamster-derived fibroblastic cell line. This transfection system resulted in the successful expression of pIgR in these cells, and Western blot analysis showed that human pIgR was expressed as two different molecular weight forms of 92 and 107 kDa. Treatment with endoglycosidase H showed that the difference between these two forms was due to the glycosylation status of the protein. In order to examine the functional role of glycosylation, we treated the transfected cells with tunicamycin, which prevents a core glycosylation step in the endoplasmic reticulum. Non-glycosylated pIgR was released into the culture medium of the transfected cells, albeit with extremely low efficiency. Taking these results together, we conclude that the glycosylation of pIgR may play a positive role in the efficient transport or release of free pIgR. 相似文献
103.
本实验通过结扎兔冠状动脉左室支复制动脉缺血-再灌注模型,应用心外膜接触电极记录单相动作电位,观察后除极电位在再灌注性心律失常中及镁离子的拮抗作用。结果表明,再灌性心律失常的52.6%与早期后去极化有关。硫酸镁可终止及预防RA,对再灌中出现触发活动有抑制作用。 相似文献
104.
用婴幼儿轮状病毒抗原免疫产卵母鸡,制备出抗婴幼儿轮状病毒鸡卵黄免疫球蛋白(抗-HRVIgY)同时研究抗-HRVIgY的抗人类胃酸屏障能力,抗消化道蛋白酶的酶解以及临床使用的安全性和效果,研究结果表明:抗-HRVIgY具有一定的抗胃酸屏障能力和抗消化道蛋白酶酶解作用,抗-HRVIgY安全无毒,对婴幼儿轮状病毒感染具有被动免疫保护作用。 相似文献
105.
Ruthenium red has been shown to have a positive inotropic effect on isolated perfused hearts. The cellular mechanism of this action is not clear. Ruthenium red is able to block the Ca2+ release channel in isolated sarcoplasmic reticulum (SR) vesicle and reconstituted channel preparations. However, the effect of ruthenium red on SR Ca2+ release has not been studied in skinned cardiac muscle preparations. In the present study we investigated the actions of ruthenium red on both the characteristics of force generation by the contractile apparatus and Ca2+ release from the SR in chemically skinned rat papillary muscle. Ruthenium red (2 and 10 M) significantly increased the Ca2+ sensitivity of the contractile apparatus (decreasing Ca2+ required for the half-maximal response from 1.56±0.04 M to 1.46±0.05 M) but had no effect on the maximal Ca2+-activated force in triton X-100 treated fibers. This result may suggest one explanation for the positive inotropic effect of ruthenium red on the heart. On the other hand, ruthenium red had no significant effect on either caffeine-induced Ca2+ release or Ca2+-induced Ca2+ release from the SR in saponin-skinned muscle fibers. Lack of a blocking effect on SR Ca2+ release by ruthenium red in skinned fibers suggests that the SR Ca2+ channels in intact preparations have characteristics that are different from those of either vesicular or reconstituted channel preparations. 相似文献
106.
Multispacer typing of Rickettsia prowazekii enabling epidemiological studies of epidemic typhus 下载免费PDF全文
Currently, there is no tool for typing Rickettsia prowazekii, the causative agent of epidemic typhus, currently considered a potential bioterrorism agent, at the strain level. To test if the multispacer typing (MST) method could differentiate strains of R. prowazekii, we amplified and sequenced the 25 most variable intergenic spacers between the R. prowazekii and R. conorii genomes in five strains and 10 body louse amplicons of R. prowazekii from various geographic origins. Two intergenic spacers, i.e., rpmE/tRNA(fMet) and serS/virB4, were variable among tested R. prowazekii isolates and allowed identification of three and two genotypes, respectively. When the genotypes obtained from the two spacers were combined, we identified four different genotypes. MST demonstrated that several R. prowazekii strains circulated in human body lice during an outbreak of epidemic typhus in Burundi. This may help to discriminate between natural and intentional outbreaks. Our study supports the usefulness of MST as a versatile method for rickettsial strain genotyping. 相似文献
107.
The role of near infrared (NIR) diffusive light imaging as an adjunct to ultrasound in differentiating benign from malignant lesions was evaluated in 27 mammography patients with infiltrating ductal carcinomas, apocrine metaplasia, fibroadenomas, radial scar and ductal hyperplasia, cysts, and normal tissues. Conventional ultrasound/mammography images were graded based on BI-RADS assessment categories. The spatial NIR measurements were made at wavelengths of 750 and 830 nm. Functional images, such as relative changes of deoxyhemoglobin (deoxyHb) and total blood concentration, were estimated from the dual wavelength measurements. Maximum relative deoxyHb and blood concentration changes were measured, and spatial correlation of masses in relative deoxyHb and blood concentration images for each breast were calculated. For the five biopsy proven benign lesions, ultrasound/mammography diagnoses were suspicious for malignancy (four cases) and highly suspicious for malignancy (one case). Four lesions showed less than 1.0 V maximum deoxyHb and less than 1.5 V maximum blood concentration levels on average and spatial image correlation showed no correlated masses in both deoxyHb and blood concentration images. For the four biopsy proven malignant lesions, ultrasound/mammography diagnoses were highly suspicious for malignancy. Maximum deoxyHb and blood concentration changes were greater than 2.9 V on average except one lesion which showed smaller deoxyHb signal (maximum 0.85 V) but the deoxyHb mass and blood concentration mass were highly correlated. 相似文献
108.
Jin H Kang Y Xiao C Zhu K Ma Y Xie Q Ma J Xie Q He C Yang Z Sun Z Zhang X Chen M Zhang F Wang B 《Viral immunology》2005,18(3):539-548
Prime-boost strategy has been exhibited its potency to enhance immune responses, which would be important to the success to develop a vaccine against the foot-and-mouth disease virus (FMDV). An eukaryotic expression construct encoding the FMDV capsid VP1 protein with a recombinant VP1 protein or a commercial FMDV vaccine were tested in the prime-boost strategy in mice and cattle trials. The levels of induced specific antibodies, T cell proliferations, and DTH activities were significantly higher in the prime-boost groups than in those vaccinated with DNA, protein or FMDV vaccine alone. More importantly, the levels of neutralizing antibodies in the former groups were significantly higher than others and could last for at least four months in cattle trials. This study suggests that the prime-boost strategy significantly improves the effective immunity and may provide a longer protection against FMDV infection. 相似文献
109.
Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. Although a benign tumor, lipoblastomas tend to recur and may resemble myxoid liposarcoma. The authors report 26 cases over a 15-year period at Texas Children's Hospital. There was a slight female predilection (14F:12M). The most common symptom was a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung were the tumor sites. Most tumors were circumscribed lipoblastomas and the minority were diffuse infiltrative lipoblastomatosis. Reexcision for residual or recurrent tumor was necessary more frequently in patients with lipoblastomatosis. Histopathologic examination and ultrastructural examination revealed cellular neoplasms composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts, a fine vascular network, and often a myxoid appearance resembling myxoid liposarcoma. Cytogenetics was performed in 4 cases with chromosome 8q abnormality being most common. The major concern with lipoblastoma in children is to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur. Although asymptomatic, lipoblastomas may cause dysfunction of other organ systems due to mass effect. Complete surgical excision with at least 2 years of follow-up is the preferred therapy. 相似文献
110.
Zhu M Natarajan R Nadler JL Moore JM Gelband CH Sumners C 《Journal of neurophysiology》2000,84(5):2494-2501
Angiotensin II (Ang II) elicits an Ang II type 2 (AT(2)) receptor-mediated increase in voltage-dependent delayed rectifier K(+) current (I(KV)) in neurons cultured from newborn rat hypothalamus and brain stem. In previous studies, we have determined that this effect of Ang II is mediated via a Gi protein, activation of phospholipase A(2) (PLA(2)), and generation of arachidonic acid (AA). AA is rapidly metabolized within cells via lipoxygenases (LO), cyclooxygenase (COX) or p450 monooxygenase enzymes, and the metabolic products are known regulators of K(+) currents and channels. Thus in the present study, we have investigated whether the AT(2) receptor-mediated effects of Ang II on neuronal I(KV) require AA metabolism and if so, which metabolic pathways are involved. The data presented here indicate that the stimulatory actions of Ang II and AA on neuronal I(KV) are attenuated by selective blockade of 12-LO enzymes. However, the effects of Ang II are not altered by blockade of 5-LO or p450 monooxygenase enzymes. Furthermore, the actions of Ang II are mimicked by a 12-LO metabolite of AA, but 5-LO metabolites such as leukotriene B(4) and C(4) do not alter neuronal I(KV). These data indicate that the AT(2) receptor-mediated stimulation of neuronal I(KV) is partially mediated through 12-LO metabolites of AA. 相似文献