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Abstract: Transgenic expression of the human complement regulatory molecule CD59 in mice and genetic deletion of the major xenoantigen galactose α 1,3 galactose (Gal KO) each resulted in partial protection of spleen cells from lysis by human serum. These protective effects were additive when the two genetic modifications were combined. However, when the effects of these genetic modifications were examined in an ex vivo model in which mouse hearts were perfused with human plasma, it was Gal KO which was the modification which determined protection. CD59 expression alone was not protective and CD59 expression in combination with Gal knockout did not result in a significant additional increase in protection over and above that provided by Gal knockout alone. The likely explanation for this discrepancy between the in vitro and ex vivo data is that the H2-Kb promoter used to drive CD59 expression results I in substantially less expression on endothelium than on spleen cells.  相似文献   
33.
小包装全氟丙烷气体动力学实验研究   总被引:1,自引:0,他引:1  
为检验塑料小包装全氟丙烷气体(C3F8)在不同包装和储存方法时浓度变化,将装有5~7mlC3F8的聚氯乙烯小袋,根据不同储藏温度和外包装方法随机分成四组:(1)22℃聚乙烯外包装,(2)36℃聚乙烯外包装,(3)22℃铝箔真空外包装,(4)-29℃聚乙烯外包装;每一组C3F8小袋气体存放一定时间后,应用气相色谱分析方法进行浓度测量。结果:第3组C3F8浓度最高和稳定,第2组浓度随放置时间降低最明显,第4组是临床应用气体的储藏和包装方法,其30天样本浓度和第3组相等,但放置一年时浓度降低。结果显示:塑料小包装C3F8予以铝箔真空外包装是一种可行的方法,利于C3F8运输和普及;聚乙烯外包装的C3F8,应放在-29℃保存,时间不超过一年。  相似文献   
34.
Background The role of IgE in airway hyperreaetivity is obscure. Objective In order to clarify the role of IgE in airway hyperreactivity, we investigated the effect of anti-IL-4 monoclonal antibody, rapamycin and interferon-γ on the antigen-induced IgE response, airway eosinophilia and hyperreactivity in mice. Methods Mice were immunized with an antigen (ovalbumin; OA) at intervals of 12 days. OA was inhaled 10 days after the secondary immunization. Twenty-four hours after the last inhalation, airway reactivity to acetylcholine was measured and bronchoalveolar lavage fluid (BALF) was obtained. Results Three inhalations of antigen caused an increase in the number of eosinophils in bronchoalveolar lavage fluid (BALF) and in airway hyperreactivity to acetylcholine with a significant elevation of serum IgE level. Anti-IL-4 at a dose of 1000 μg/animal and rapamycin at doses between 0.1 and 1 mg/kg inhibited the IgE production, but did not affect the airway eosinophilia or hyperreactivity to acetylcholine. In contrast, IFN-γ clearly inhibited the antigen-induced airway eosinophilia and hyperreactivity, but did not affect the IgE antibody production. Conclusion These results suggest that the inhibition of IgE production does not suppress the onset of airway hyperreactivity and eosinophilia in mice, and that IFN-γ inhibits the antigen-induced airway hyperreactivity, probably due to the inhibition of airway eosinophilia.  相似文献   
35.
The present work tries to establish the antioxidant capacity of the peripheral nervous tissue of the rat, in terms of the enzymatic activities present in this tissue that either prevent the formation of activated species as the semiquinone radical (DT-diaphorase), protect against activated oxygen species (superoxide dismutase, glutathione peroxidase), conjugate natural toxic products or xenobiotics (glutathione S-transferases, especially the activity conjugating 4-hydroxy-nonenal), or complete the glutathione system metabolism (glutathione disulfide reductase, γ-glutamyl transpeptidase). All the activities studied are lower in this tissue than they are in liver, except for γ-glutamyl transpeptidase. The relevance of the results obtained and its possible relationship with different neuropathies is discussed. It is concluded that the peripheral nervous tissue is by far less protected than the liver against oxidative damage.  相似文献   
36.
Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B2, prostaglandin E2, leukotriene B4 and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B2 was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E2 & leukotriene B4 peaks and a second peak of thromboxane B2 were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothetized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms.  相似文献   
37.
One hundred endolymphatic mastoid shunt operations in 89 patients with classical Menière's disease were analysed. The disease was bilateral in 18 patients (20%). The patients were carefully pre-selected by a comprehensive protocol of audiovestibular and metabolic investigations. All patients had definite electrophysiological evidence of endolymphatic hydrops with an enhanced negative summating potential on transtympanic electrocochleography. The surgical results were analysed both by the original American Academy of Ophthalmology and Otolaryngology Guidelines (AAOO, 1972) and the more recent modifications of the American Academy of Otolaryngology, Head and Neck Surgery (AA-HNS, 1985). Control of the vertigo was achieved in 81% of the patients overall, in 88% of the patients with unilateral disease and in 63% of the patients with bilateral disease. A significant hearing improvement was obtained in 19% of patients, no change in 55% and hearing became worse in 26%. Tinnitus improved in 38% of patients, was unchanged in 52% and became worse in 10%. Disability was assessed and there was no disability in 44% of the patients post-operatively, some degree of disability in 48% but only 8% were severely disabled and unable to sustain gainful employment.  相似文献   
38.
在微量注射大量肝脏mRNA之后,通过电压箝方法进行功能鉴定,两栖类卵母细胞成功地表达了AVPV1a受体。但在灌流AV4-8溶液时,却不能诱导卵母细胞产生内向振荡电流反应。提示AVP4-8不能通过AVPV1a受体而介导生理学效应。  相似文献   
39.
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed.  相似文献   
40.
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