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61.
The involvement of sulphate‐reducing bacteria (SRB) in microbially influenced corrosion (MIC) of steel and the serious implications associated with their presence in industrial environments have long been known and extensively described. Desulfovibrio desulfuricans ATCC 27774 is an interesting metabolic case of SRB, as it can use both sulphate and nitrate as respiratory substrates during lactate oxidation. This strain has been extensively studied from both a biochemical and structural point of view but, so far, restricted information is available concerning its role in MIC. This work describes a comparative study of the corrosive aggressivity of ATCC 27774 strain towards mild steel when grown either in lactate/sulphate or lactate/nitrate media. The carbon source and electron acceptor's consumption rates were analysed and the metabolic features were correlated with weight loss measurements and SEM observations.  相似文献   
62.
The latex obtained from Hancornia speciosa is used in folk medicine for treatment of several diseases, such as acne, warts, diabetes, gastritis and inflammation. In this work, we describe the biocompatibility assessment and angiogenic properties of H. speciosa latex and its potential application in medicine. The physical–chemical characterization was carried out following different methodologies (CHN elemental analyses; thermogravimetric analyses and Fourier transform infrared spectroscopy). The biocompatibility was evaluated through cytotoxicity and genotoxicity tests in fibroblast mouse cells and the angiogenic properties were evaluated using the chick chorioallantoic membrane (CAM) assay model. The physical–chemical results showed that the structure of Hancornia speciosa latex biomembrane is very similar to that of Hevea brasiliensis (commercially available product). Moreover, the cytotoxicity and genotoxicity assays showed that H. speciosa latex is biocompatible with life systems and can be a good biomaterial for medical applications. The CAM test showed the efficient ability of H. speciosa latex in neovascularization of tissues. The histological analysis was in accordance with the results obtained in the CAM assay. Our data indicate that the latex obtained from H. speciosa and eluted in water showed significant angiogenic activity without any cytotoxic or genotoxic effects on life systems. The same did not occur with H. speciosa latex stabilized with ammonia. Addition of ammonia does not have significant effects on the structure of biomembranes, but showed a smaller cell survival and a significant genotoxicity effect. This study contributes to the understanding of the potentialities of H. speciosa latex as a source of new phytomedicines.  相似文献   
63.
The clinical and radiological features in 100 patients with collagen diseases (rheumatoid arthritis, lupus, sclerodermia, dermatomyositis, and panarteritis nodosa) were compared with respiratory performance. 56 patients were drawn from the series of Pende et Al. and 44 from a personal series. The results are set out in tables and graphs. It was found that lung lesions due to collagen disease have no special clinical and radiological features. Respiratory performance is that of a restrictive syndrome that gradually progresses from A.R. to E.S., S. and P.M., accompanied by obstruction of the large airways, as shown by hyperinsufflation in sclerodermia and reduced specific conductance in rheumatoid arthritis.  相似文献   
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65.
BACKGROUND: Transcatheter arterial chemoembolisation, a procedure for the treatment of hepatocellular carcinoma, provokes a pronounced but transient increase in hepatic cytolysis parameters. A definite evaluation of the impairment of liver function after this treatment, performed by adequate techniques, is still lacking. AIMS: To assess and quantify the impairment of liver metabolic activity after arterial chemoembolisation in patients with cirrhosis. The variations of hepatic vein pressure gradient provoked by this procedure were evaluated. PATIENTS: 15 patients with cirrhosis (Child's class A and B) and hepatocellular carcinoma. METHODS: 17 transcatheter arterial chemoembolisations with epirubicin, iodised oil, and gelfoam were performed; liver function was assessed before, the following day, and after seven days measuring galactose elimination capacity; aminopyrine breath test was also performed in six patients before the procedure and seven days after. In 10 patients intrinsic hepatic clearance of indocyanine green and hepatic vein pressure gradient were measured by hepatic vein catheterisation before and 30 minutes after chemoembolisation. RESULTS: Intrinsic hepatic clearance of indocyanine green decreased significantly from (mean (SEM)) 355 (140) ml/min to 277 (98) ml/min after the procedure (p = 0.0007). Galactose elimination capacity did not show significant changes, being 4.00 (0.90) mg/min/kg body weight at baseline, 4.20 (0.90) mg/min/kg body weight after one day, and 3.95 (0.87) mg/min/kg body weight seven days after chemoembolisation. Aminopyrine breath test was 2.31 (1.09)% and remained unchanged after treatment, being 2.39 (2.04)% at day 7. Baseline hepatic vein pressure gradient was 17.0 (5.5) mm Hg, and 14.4 (3.7) mm Hg 30 minutes after chemoembolisation (p = 0.09). CONCLUSIONS: A single transcatheter chemoembolisation in cirrhotic patients was detected by galactose elimination capacity and aminopyrine breath test one and seven days after the procedure. Therefore it can be considered a safe therapeutic tool for hepatocellular carcinoma in Child's class A and B cirrhotic patients.  相似文献   
66.
To gain insight into the factors controlling the maintenance or loss of T cell self tolerance we produced beef insulin (BI)-transgenic BALB/c mice. Transgenic mice express BI under control of the human insulin promoter and secrete physiological amounts of beef insulin. Although these mice are tolerant to BI, as evidenced by the lack of insulin-specific IgG antibody production following intraperitoneal immunization, tolerance is not complete. Footpad immunization results in a weak antigen-specific T cell proliferative response, indicating the presence of self-reactive BI-specific T cell in the periphery. These T cells are functional in vivo, providing support for IgG1, IgG2a, and IgG2b BI-specific antibody production, but require higher higher concentrations of antigen than nontransgenic T cells (both in vivo and following recall responses in vitro) to become activated. In vitro, BI-specific T cell proliferation in BI-transgenic mice can be largely restored by addition of interleukin-2, indicating that a significant component of T cell tolerance is mediated by anergy. To characterize the autoreactive T cells that become activated when tolerance is broken, BI-specific T cell hybridomas were generated from transgenic mice and compared to a panel of hybridomas previously derived from nontransgenic BALB/c mice. The majority of BI-transgenic hybridomas recognized the immunodominant A1-14 beef insulin peptide but with lower avidity than BALB/c hybridomas. Consistent with this, none of the dominant T cell receptor rearrangements found in the BALB/c BI-specific T cell receptor repertoire were found in the transgenic hybridomas. These results indicate that, despite evidence for clonal inactivation of many BI-specific T cells in BI-transgenic mice, loss of tolerance results from activation of low-affinity antigen-specific T cells that appear to have escaped this process.  相似文献   
67.
68.
cAMP-dependent protein kinase (PKA) is composed of two genetically distinct catalytic (C) and regulatory (R) subunits. There are two different classes of PKA, designated as type I and type II, which contain distinct R subunits (RI or RII, respectively) but share a common C subunit. Enhanced expression of type I PKA has been correlated with cell proliferation and neoplastic transformation. Detection of the different PKA subunits is usually performed by photoaffinity labeling with 8-N3-32P-cAMP or by radioimmunolabeling techniques. Both techniques are time consuming and require a high number of cells and the use of radioactive reagents. Using the MCF-10A normal human mammary cell line infected with a recombinant retroviral vector containing the human RI alpha gene (MCF-10A RI alpha), we have developed a flow-cytometric assay to detect the intracellular content of RI alpha protein in human cells. MCF-10A and MCF-10A RI alpha cells were fixed in 1.5% paraformaldehyde at 37 degrees C for 15 min and permeabilized by methanol and acetone (1:1) at -20 degrees C for 5 min before staining with a specific IgG2a MoAb followed by a FITC-conjugate rabbit-anti mouse IgG. This procedure was also successfully utilized to recognize RI alpha protein content in human peripheral blood lymphocytes. Flow-cytometric detection of the RI alpha subunit in human cells is feasible and allows the study of the role of type I PKA in cell growth and neoplastic transformation.  相似文献   
69.
Franzen PL  Misoguti L  Zilio SC 《Applied optics》2008,47(10):1443-1446
We propose a method for measuring hyper-Rayleigh scattering employing pulse trains produced by a Q-switched and mode-locked Nd:YAG laser. The use of the entire pulse train under the Q-switch envelope avoids the need of any device to scan the irradiance, as is usually done with nanosecond and femtosecond single-pulse lasers. To verify the feasibility of the technique, we performed measurements in different solutions of para-nitroaniline and compared the results with those obtained with nanosecond pulses. In both cases, the agreement with the hyperpolarizability values reported in the literature is about the same, but the measurements carried out with pulse trains are at least 20 times faster. Besides the advantage of acquisition speed, the use of pulse trains also allows the instantaneous inspection of slow luminescence contributions arising from multiphoton absorption.  相似文献   
70.
Over the past two decades, private house ownership has expanded exponentially throughout Europe. Over the past decade, this has intensified with the desire and ability among wealthier northern Europeans to own second homes in sunnier climes. It has not only driven up house prices in pockets of Europe, but has also impacted on the social and cultural lives of local communities in ‘desirable locations’, having an adverse effect on the quality of the built environment. Lino Bianco describes the situation in Malta and how, after decades of largely uncontrolled development by real-estate investors, the government is taking stock and encouraging through investment in architectural education, and property legislation, the growth of an indigenous architecture that is contextual, sensitive and energy-conscious. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
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