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排序方式: 共有167条查询结果,搜索用时 15 毫秒
1.
Lucia Pitzurra Manuela Puliti Mohamed Ali Burhan Fuad Francesco Bistoni Elisabetta Blasi 《FEMS immunology and medical microbiology》1993,7(4):289-295
Abstract The present study was designed to establish the susceptibility of macrophage-mediated effector functions to tetanus toxin (TT). Using the murine macrophage cell line, GG2EE, generated in vitro by v- raf /v- myc oncogenes, we have previously provided evidence that TT selectively inhibits interferon gamma (IFN-γ), but not basal, lysozyme activity. Here we show that while neither phagocytic nor candidacidal activities are affected by TT treatment, antitumoral activity is significantly impaired after exposure to TT. This phenomenon, which is dose-dependent, is fully ascribed to the holotoxin, as heat inactivated TT, C or A-B fragments result ineffective. Furthermore, C but not A-B fragment competes with TT in abrogating its inhibitory effects. Overall, these data indicate that TT is not a broad-spectrum, down-regulating signal on macrophage-mediated functions, thus implying that its toxic action is exerted on specific molecular targets. 相似文献
2.
The effect of cyclic anaerobic–aerobic conditions on the biodegradative capability of the mixed microbial culture for the
azo dye Remazol Brilliant Violet 5R (RBV-5R) was investigated in the sequencing batch reactor (SBR) fed with a synthetic textile
wastewater. The SBR had a 12-h cycle time with anaerobic–aerobic periods of 3/9, 6/6 and 9/3 h. General SBR performance was
assessed by measurement of catabolic enzymes (catechol 2,3-dioxygenase, azo reductase), chemical oxygen demand (COD), color
and amount of aromatic amines. In this study, under steady-state conditions, the anaerobic period of the cyclic SBR was found
to allow the reductive decolorization of azo dye. Longer anaerobic periods resulted in higher color removal efficiencies,
approximately 71% for the 3-h, 87% for 6-h and 92% for the 9-h duration. Total COD removal efficiencies were over 84% under
each of the cyclic conditions and increased as the length of the anaerobic period was increased; however, the highest color
removal rate was attained for the cycle with the shortest anaerobic period of 3 h. During the decolorization of RBV-5R, two
sulfonated aromatic amines (benzene based and naphthalene based) were formed. Additionally, anaerobic azo reductase enzyme
was found to be positively affected with the increasing duration of the anaerobic period; however; it was vice versa for the
aerobic catechol 2,3-dioxygenase (C23DO) enzyme. 相似文献
3.
Vegetation History and Archaeobotany - Studies of the origins of agriculture in the Near East have revealed that the eight plant species known as “Founder Crops”, i.e. emmer, einkorn,... 相似文献
4.
Asiye Başusta Burak Çetinkaya Nuri Başusta 《Zeitschrift fur angewandte Ichthyologie》2020,36(6):888-892
Fish specimens were captured by a commercial bottom trawler at a depth of 50–80 m from Iskenderun Bay (Hatay, Turkey) between December 2017 and May 2018. The bottom trawl gear used was equipped with a 44 mm stretched mesh size net at the cod-end. Blind side and eyed side otolith lengths (OL), otolith breadths (OB) and otolith weights (OW) were measured from each specimen to the nearest 0.001 mm and 0.0001g respectively. A total of 110 fish (43 females and 67 males) were collected. Total length ranged from 20.8 to 28.2 cm and 68.0 to 166.1 g (males) and 21.1 to −28.5 cm and 74.5 to 201.4 g (females). The coefficients of determination between fish weight and otolith weight, and total length and otolith weight (sexes combined) were found as R2 = .7694 (0.77) and R2 = .6274 (0.63), respectively. A moderate positive relationship between the total length-otolith dimensions, and fish weight-otolith dimensions, was also demonstrated. 相似文献
5.
Pericytes are CD146+ perivascular cells (PCs) that have multipotential differentiation capacity as mesenchymal stem cells. Beside their crucial roles in vascular development and blood flow regulation, they have ability to differentiate into vascular cell types in vivo. These properties make pericytes preferred cells in the field of vascular tissue engineering. Culture medium for in vitro differentiation of pericytes to vascular smooth muscle cells (SMCs) has not been defined yet. The aim of this study is to try different culture media for SMC differentiation of CD146+ PCs. For this purpose, CD146+ PCs were isolated from human umbilical cord vein. Then they were characterized by immunofluorescence staining and flow cytometric analysis. Three different culture media including; (1) Transforming growth factor beta 1 (TGF-β1)+ bone morphogenic protein 4, (2) TGF-β1+ l-ascorbic acid (l-AA) and (3) Horse serum, were compared for differentiation of CD146+ PCs to SMCs by IFS and real time polymerase chain reaction. As a result, in the case of SMC differentiation of CD146+ PCs, second culture medium including TGF-β1 and l-AA was found to be more effective than other two media. These results are important for establishing proper culture conditions for in vitro SMC differentiation of CD146+ PCs. 相似文献
6.
Queck SY Jameson-Lee M Villaruz AE Bach TH Khan BA Sturdevant DE Ricklefs SM Li M Otto M 《Molecular cell》2008,32(1):150-158
Cell-density-dependent gene regulation by quorum-sensing systems has a crucial function in bacterial physiology and pathogenesis. We demonstrate here that the Staphylococcus aureus agr quorum-sensing regulon is divided into (1) control of metabolism and PSM cytolysin genes, which occurs independently of the small regulatory RNA RNAIII, and (2) RNAIII-dependent control of additional virulence genes. Remarkably, PSM expression was regulated by direct binding of the AgrA response regulator. Our findings suggest that quorum-sensing regulation of PSMs was established before wide-ranging control of virulence was added to the agr regulon, which likely occurred by development of the RNAIII-encoding region around the gene encoding the PSM delta-toxin. Moreover, the agr regulon in the community-associated methicillin-resistant S. aureus MW2 considerably differed from that previously determined using laboratory strains. By establishing a two-level model of quorum-sensing target gene regulation in S. aureus, our study gives important insight into the evolution of virulence control in this leading human pathogen. 相似文献
7.
The intestinal parasites are noted to be an important health problem in Turkey as similarly reported in the globe. The aim of this study was to investigate the changes in total content of essential elements, namely, zinc, iron, copper, cobalt, magnesium, and selenium, in children infected with intestinal parasites aged between 6 and 12 years inhabiting in Hatay Province, Turkey. These essential elements were measured in the children/patient who was positive for intestinal parasites, Giardia intestinalis and Enterobius vermicularis. Scores were obtained from the positive study group (SG), and their age matched the healthy children control group (CG). Serological levels of zinc, iron, copper, cobalt, magnesium, and selenium were analyzed by Varian Liberty Series II inductively coupled plasma atomic emission spectrometer (ICP-AES). The mean magnesium concentrations were found to be statistically different at 95% confidence interval level between study groups. As a result of this study, selenium was found to be uncorrelated with all other elements examined; whereas, copper was observed to have statistically significant correlations with cobalt, magnesium, and zinc. In addition, cobalt-magnesium, cobalt-zinc, and magnesium-zinc metal pairs were found to have statistically significant correlations based on study findings. 相似文献
8.
Celik-Ozenci C Akkoyunlu G Korgun ET Savas B Demir R 《Molecular reproduction and development》2004,67(4):414-423
It is accepted that angiogenesis plays an important role in the development of the corpus luteum (CL) and is probably necessary for normal lutein cell function. A number of drugs currently being tested in clinical trials as possible angiogenesis inhibitors were not originally developed with the intention of suppressing tumor angiogenesis. Interferon alpha (IFN-alpha) is one of the notable examples of such 'accidental angiogenesis inhibitors' and daily administration of IFN-alpha is known to suppress tumor growth, tumor vascularization, and down-regulation of various growth factors. We investigated the effects of IFN-alpha treatment on the expression of vascular endothelial growth factor (VEGF), and its receptors KDR and Flt-1, and CD34 in CL during the first week of pseudopregnancy and pregnancy in hormonally induced rat ovaries by immunohistochemistry and Western blot techniques. Basal body temperatures of the drug-treated rats, as an indicator of treatment effect, were determined daily and were increased significantly when compared to controls (38.03 +/- 0.18 vs. 36.6 +/- 0.1 degrees C), respectively. The effect of IFN-alpha treatment was minimal when the entire week was evaluated, however, the expression of VEGF decreased at 3rd, 5th, and 7th days of both pregnancy and pseudopregnancy, when compared to the 1st day, whereas there was not a such alteration in the untreated rats regarding these days. The daily subcutaneous administrations of 672.500 U IFN-alpha2b had minimal effects on the expressions of VEGF, and its two receptors KDR and Flt-1 in either pregnant or pseudopregnant corpora lutea utilizing HSCORE. 相似文献
9.
Işcan M Ada AO Coban T Kapucuoğlu N Aydin A Isimer A 《Biological trace element research》2002,89(2):177-190
When male rats were given a single dose of cadmium (Cd) (3.58 mg CdCl2·H2O/kg, ip) 72 hr prior to sacrifice, the testicular 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities toward the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB),
ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (EPNP), and cumene hydroperoxide (CHPx) decreased significantly as compared to controls. Cd also inhibited
reduced glutathione (GSH) level while increasing the lipid peroxidation (LP) level significantly. When the animals were given
a single dose of nickel (Ni) (59.5 mg NiCl2·6H2O/kg, ip) 16 hr prior to sacrifice, significant decreases were observed in EROD and GST activities toward CDNB, EAA, EPNP,
and CHPx, and GSH level. No significant alterations were noted in DCNB GST activity and LP level by Ni. For the combined treatment,
rats received the single dose of Ni 56 hr after the single dose of Cd and were killed 16 hr later. In these animals, lesser
depressions were observed on EROD activity and LP level than those of Cd alone. The combination of metals significantly inhibited
GST activities and GSH level but not to a greater degree than noted by Cd or Ni alone. Plasma testosterone levels of Cd-,
Ni-, and combination-treated rats decreased significantly compared to controls. The strongest depression was achieved by Cd
alone. Cd, both alone and in combination with Ni, increased the tissue Ni uptake significantly. Ni, however, did not produce
such an effect on the tissue uptake of Cd in either case. Cd treatment caused interstitial edema and coagulation necrosis
in seminiferous tubules and also caused fibrinoidal necrosis in vascular endothelium. Ni treatment did not produce any pathological
testicular alterations compared to controls. Combined treatment produced fewer pathological alterations (i.e., only interstitial
edema) than that of Cd treatment. These results reveal that the combination of Cd and Ni does not have a synergistic effect
on testicular xenobiotic metabolizing enzymes, and in contrast, Ni has an ameliorating effect on pathological disturbances
caused by Cd alone in the rat testis. 相似文献
10.
Effects of oxygen transfer on recombinant protein production by Pichia pastoris under glyceraldehyde-3-phosphate dehydrogenase promoter were investigated. Recombinant glucose isomerase was chosen as the model protein. Two groups of oxygen transfer strategies were applied, one of which was based on constant oxygen transfer rate where aeration rate was Q O/V = 3 and 10 vvm, and agitation rate was N = 900 min?1; while the other one was based on constant dissolved oxygen concentrations, C DO = 5, 10, 15, 20 and 40 % in the fermentation broth, by using predetermined exponential glucose feeding with μ o = 0.15 h?1. The highest cell concentration was obtained as 44 g L?1 at t = 9 h of the glucose fed-batch phase at C DO = 20 % operation while the highest volumetric and specific enzyme activities were obtained as 4440 U L?1 and 126 U g?1 cell, respectively at C DO = 15 % operation. Investigation of specific enzyme activities revealed that keeping C DO at 15 % was more advantageous with an expense of relatively higher by-product formation and lower specific cell growth rate. For this strategy, the highest oxygen transfer coefficient and oxygen uptake rate were K L a = 0.045 s?1 and OUR = 8.91 mmol m?3 s?1, respectively. 相似文献