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The aim of the study was a cross-cultural comparison of personality traits between individuals from two very different cultures and refugees who resettled several years before from one to the other. Four hundred forty four Swedish individuals of the normal population; and 100 Iranian refugees in Sweden, and a group of 335 individuals from Tehran, capital of Iran, were investigated by means of the Temperament and Character Inventory, a questionnaire to assess temperament and character Iranians are those that are most frequently correctly classified followed by the Swedish based on temperament scores by means of a Discriminance analyses. Iranian refugees in Sweden were classified to about 50 per cent as Swedish and to slightly more then one-third as Iranians. Especially concerning character, 4 per cent only could be correctly classified as refugees. The results give some perspective on the adaptation process and personality changes in refugees several years after resettlement in another country with a complete different culture.  相似文献   

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Summary The dual localization of certain hydrolases in lysosomes and in endoplasmic reticulum as studied in enzyme staining reactions is now supported by cytobiochemical studies on mouse liver and kidney -glucuronidase and acid phosphatase. Use was made of the renal -glucuronidase response to endogenous androgen for both studies. Accordingly, sucrose homogenates were prepared of liver and kidney of male BALB/C mice previously injected with gonadotrophin along with control animals receiving saline instead. The homogenates were subjected to differential ultracentrifugation yielding six fractions. These were characterized as to their organelle composition by measurements of marker enzymes and by observations with the electron microscope. In all subcellular fractions, -glucuronidase was uniformly increased 5 to 8 times over the corresponding control value and, in fractions rich in lysosomes, this enzyme was easily released by alternate freezing and thawing. On the other hand, the microsomal -glucuronidase and acid phosphatase enzymes were not liberated by freezing and thawing nor were they after treatment with 0.1 % Triton X-100 and by employing other reagents and conditions which are known to release lysosomal enzymes. In contrast to microsomal acid phosphatase, microsomal -glucuronidase activity could be liberated by treatment with hyaluronidase. This soluble -glucuronidase showed the same optimum pH, Michaelis Constant and heat inactivation behavior as the lysosomal -glucuronidase prepared by freezing and thawing treatment. These observations define two populations of microsomal vesicles each identifiable by an individual membrane-associated acid hydrolase. One of these -glucuronidase, increases in specific activity in the animal on androgens and is released by hyaluronidase and the other, acid phosphatase, does not respond to androgen and is not released by hyaluronidase. There would appear to be a variety of mechanisms by which hydrolases enter into association with the membranes of the endoplasmic reticulum and from there, a variety of routes to the lysosomes. A comment is made concerning the question of acid phosphatases and -glucuronidase as enzyme markers for lysosomes in mouse kidney.Aided in part by Research Grant, P-106, of the American Cancer Society, Inc., New York, and by U.S.P.H.S. Grant CA-07538 and by a Research Career Award, CA-K6-18453 to William H. Fishman.  相似文献   

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From in vitro studies involving multilamellar liposomes or other artificial systems, several groups of workers have deduced that Trolox (a water-soluble analogue of vitamin E) and ascorbate are synergistic antioxidants. Here, we demonstrate that while Trolox and ascorbate individually protect cultured hepatocytes against oxyradicals generated either with xanthine oxidase plus hypoxanthine or with hydrogen peroxide, the two antioxidants do not appear to be synergistic when used in equimolar combinations. Also, in a rat model of hepatic ischemia-reperfusion, we observed that infusion of Trolox or ascorbate (7.5-10 mumol/kg body weight) into the postischemic liver reduced the reperfusion injury by 76 or 67%, respectively. However, when both compounds were used together (each at the same dose as used separately), the organ salvage amounted to only 79%. Therefore, there is no evidence of synergism between Trolox and ascorbate in our in vitro and especially in vivo systems.  相似文献   

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For many years, zinc salts have been used both topically and orally to treat minor burns and abrasions as well as to enhance wound repair in man and animals. In this study we describe the protective effects of zinc against UV-induced genotoxicity in vitro and against sunburn cell formation in mouse skin in vivo. Cultured skin cells from neonatal mice showed a dramatic increase in the number of micronuclei as a result of UVA and UVB irradiation. Inclusion of zinc at 5 μg/mL in the medium significantly reduced the frequency of micronuclei and of micronucleated cells. In hairless mice, topical application of zinc chloride for 5 consecutive days or a single application 2 h prior to UV exposure reduced the number of sunburn cells in the epidermis as did application of zinc 1 h after exposure. Application 2 h after irradiation also tended to have a protective effect, although there was a large variation between animals. It is proposed that an influx of zinc can protect epidermal cells against some of the more delayed effects of UV-induced damage.  相似文献   

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Background

Hypoxia inducible factor-1α (HIF-1α) is responsible for the majority of HIF-1-induced gene expression changes under hypoxia and for the “angiogenic switch” during tumor progression. HIF-1α is often upregulated in tumors leading to more aggressive tumor growth and chemoresistance, therefore representing an important target for antitumor intervention. We previously reported that zinc downregulated HIF-1α levels. Here, we evaluated the molecular mechanisms of zinc-induced HIF-1α downregulation and whether zinc affected HIF-1α also in vivo.

Methodology/Principal Findings

Here we report that zinc downregulated HIF-1α protein levels in human prostate cancer and glioblastoma cells under hypoxia, whether induced or constitutive. Investigations into the molecular mechanisms showed that zinc induced HIF-1α proteasomal degradation that was prevented by treatment with proteasomal inhibitor MG132. HIF-1α downregulation induced by zinc was ineffective in human RCC4 VHL-null renal carcinoma cell line; likewise, the HIF-1αP402/P564A mutant was resistant to zinc treatment. Similarly to HIF-1α, zinc downregulated also hypoxia-induced HIF-2α whereas the HIF-1β subunit remained unchanged. Zinc inhibited HIF-1α recruitment onto VEGF promoter and the zinc-induced suppression of HIF-1-dependent activation of VEGF correlated with reduction of glioblastoma and prostate cancer cell invasiveness in vitro. Finally, zinc administration downregulated HIF-1α levels in vivo, by bioluminescence imaging, and suppressed intratumoral VEGF expression.

Conclusions/Significance

These findings, by demonstrating that zinc induces HIF-1α proteasomal degradation, indicate that zinc could be useful as an inhibitor of HIF-1α in human tumors to repress important pathways involved in tumor progression, such as those induced by VEGF, MDR1, and Bcl2 target genes, and hopefully potentiate the anticancer therapies.  相似文献   

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To contribute to the question of the putative role of cystatins in Alzheimer disease and in neuroprotection in general, we studied the interaction between human stefin B (cystatin B) and amyloid-β-(1–40) peptide (Aβ). Using surface plasmon resonance and electrospray mass spectrometry we were able to show a direct interaction between the two proteins. As an interesting new fact, we show that stefin B binding to Aβ is oligomer specific. The dimers and tetramers of stefin B, which bind Aβ, are domain-swapped as judged from structural studies. Consistent with the binding results, the same oligomers of stefin B inhibit Aβ fibril formation. When expressed in cultured cells, stefin B co-localizes with Aβ intracellular inclusions. It also co-immunoprecipitates with the APP fragment containing the Aβ epitope. Thus, stefin B is another APP/Aβ-binding protein in vitro and likely in cells.  相似文献   

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Rorsman P  Braun M  Zhang Q 《Cell calcium》2012,51(3-4):300-308
The glucoregulatory hormones insulin and glucagon are released from the β- and α-cells of the pancreatic islets. In both cell types, secretion is secondary to firing of action potentials, Ca(2+)-influx via voltage-gated Ca(2+)-channels, elevation of [Ca(2+)](i) and initiation of Ca(2+)-dependent exocytosis. Here we discuss the mechanisms that underlie the reciprocal regulation of insulin and glucagon secretion by changes in plasma glucose, the roles played by different types of voltage-gated Ca(2+)-channel present in α- and β-cells and the modulation of hormone secretion by Ca(2+)-dependent and -independent processes. We also consider how subtle changes in Ca(2+)-signalling may have profound impact on β-cell performance and increase risk of developing type-2 diabetes.  相似文献   

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NPY is present in the retina of different species but its role is not elucidated yet. In this work, using different rat retina in vitro models (whole retina, retinal cells in culture, microglial cell cultures, rat Müller cell line and retina endothelial cell line), we demonstrated that NPY staining is present in the retina in different cell types: neurons, macroglial, microglial and endothelial cells. Retinal cells in culture express NPY Y(1), Y(2), Y(4) and Y(5) receptors. Retina endothelial cells express all NPY receptors except NPY Y(5) receptor. Moreover, NPY is released from retinal cells in culture upon depolarization. In this study we showed for the first time that NPY is present in rat retina microglial cells and also in rat Müller cells. These in vitro models may open new perspectives to study the physiology and the potential pathophysiological role of NPY in the retina.  相似文献   

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As is well known from earlier studies, the genotoxic effect of lead exposure was partly attributed to the formation of the highly reactive oxygen metabolites (ROMs) in the blood. However, lead ions have no ability to generate ROMs. Therefore, the recently published studies paid more attention to the role of δ-aminolevulinic acid (ALA) accumulation in lead-induced DNA damage. If the above-mentioned assumptions were taken into consideration, it seemed a reasonable approach to study the possible protective effects of antioxidants against genotoxic effects of lead. According to our results, N-acetylcysteine (NAC) and melatonin (MEL) were able to reduce significantly (p < 0.05) the lead- and ALA-induced sister chromatid exchange frequencies in human lymphocytes in vitro. In spite of a relative reduction in the lead- and ALA-induced micronucleus formation in human lymphocytes, the reduction was not statistically significant (p > 0.05). These results could be evaluated as supportive evidence for the hypothesis that increased antioxidant capacity of cells might fortify the efficiency of protective pathways against cytogenetic damage in lead exposure.  相似文献   

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The genesis of wheat microsporial polyembryoids in vitro was analyzed in detail. The nature of different phenotypes of cereal polymeric embryos was identified. They represent the class “multiple shoot meristems,” which results from a cleavage polyembryony and is accompanied by organ fasciations of all known types (radial, flat, or ring). The morphological nature of cereal embryonic organs has been clarified: shoot meristem—axial organ; scutellum—lateral outgrowth of this axis; coleoptile—derivative of shoot meristem but fused with scutellum; terminality of scutellum—the result of linear fasciation that occurred historically. An explanation is given on how the structural model of an auxin polar transport works during the establishment of bilateral symmetry in a cereal embryo that is associated with the inverted polarization of the carrier protein PIN1 on cell membranes and, correspondingly, with the inverted auxin transport performed by this carrier (Fischer-Iglesias et al., 2001; Forestan et al., 2010).  相似文献   

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Background

Emerging bacterial zoonoses in bats and rodents remain relatively understudied. We conduct the first comparative host–pathogen coevolutionary analyses of bacterial pathogens in these hosts, using Bartonella spp. and Leptospira spp. as a model.

Methodology/Principal Findings

We used published genetic data for 51 Bartonella genotypes from 24 bat species, 129 Bartonella from 38 rodents, and 26 Leptospira from 20 bats. We generated maximum likelihood and Bayesian phylogenies for hosts and bacteria, and tested for coevoutionary congruence using programs ParaFit, PACO, and Jane. Bartonella spp. and their bat hosts had a significant coevolutionary fit (ParaFitGlobal = 1.9703, P≤0.001; m2 global value = 7.3320, P≤0.0001). Bartonella spp. and rodent hosts also indicated strong overall patterns of cospeciation (ParaFitGlobal = 102.4409, P≤0.001; m2 global value = 86.532, P≤0.0001). In contrast, we were unable to reject independence of speciation events in Leptospira and bats (ParaFitGlobal = 0.0042, P = 0.84; m2 global value = 4.6310, P = 0.5629). Separate analyses of New World and Old World data subsets yielded results congruent with analysis from entire datasets. We also conducted event-based cophylogeny analyses to reconstruct likely evolutionary histories for each group of pathogens and hosts. Leptospira and bats had the greatest number of host switches per parasite (0.731), while Bartonella and rodents had the fewest (0.264).

Conclusions/Significance

In both bat and rodent hosts, Bartonella exhibits significant coevolution with minimal host switching, while Leptospira in bats lacks evolutionary congruence with its host and has high number of host switches. Reasons underlying these variable coevolutionary patterns in host range are likely due to differences in disease-specific transmission and host ecology. Understanding the coevolutionary patterns and frequency of host-switching events between bacterial pathogens and their hosts will allow better prediction of spillover between mammal reservoirs, and ultimately to humans.  相似文献   

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A link between biological and human sciences may be established, under the condition that we should admit the existence of reciprocal influences between them. The model for the regulation of agonistic antagonistic couples (MRAAC) is built from the study of biological systems and gives rise to specific types of control. This model can be helpful in decision processes in some human sciences such as management, economical and political strategies. The reason for such an opportunity lies in the fact that MRAAC is a general and phenomenological model able to incorporate the whole of the agonistic antagonistic systems. This type of regulation might be related to the concept of the viability of a system (yet also valid for human science systems) and to a functional and structural pattern which is the basis for agonistic antagonistic networks.  相似文献   

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ABSTRACT

Interleukin-23 (IL-23, IL-23p19) is a proinflammatory cytokine in the IL-12-related family. Although inflammatory cells in herniated discs have been shown to contain IL-23, little is known about the presence and role of IL-23 in human disc cells. We analyzed disc specimens for IL-23 localization using immunohistochemistry in control, herniated and non-herniated discs from which annulus fibrosus (annulus) cells were isolated and cultured to identify IL-23 gene expression and production. Microarray analysis was used to assess the expression of IL-23 in disc tissue and in cells exposed to two proinflammatory cytokines, IL-1ß and TNF-α. IL-23 was present in annulus cells at the protein level and its expression was up-regulated significantly in herniated compared to control disc tissue. Direct measurement of medium components confirmed production of IL-23 and its receptor, IL-23R, by annulus cells in vitro. Annulus cells in three-dimensional culture exposed to TNF-α, but not IL-1ß, resulted in significant up-regulation of IL-23 expression compared to control cells. Our findings are evidence for the constitutive presence of IL-23 in the human disc and that its expression in vitro is modified by exposure to TNF-α.  相似文献   

19.
The diversification and distribution of Abies species throughout the Mediterranean region has led to a complex of species which are difficult to classify. An open question is whether these mainly allopatric taxa have exchanged genetic information via secondary contact. We studied the variation and geographic distribution of paternally inherited chloroplast DNA markers in nine Mediterranean Abies taxa. Markers with high and low mutation rates were applied in order to differentiate among a scenario of secondary genetic contact and a scenario of complete isolation after speciation. The observed molecular variation was analysed using statistical parsimony, geostatistics, and measures of population genetic differentiation. Ancient paternal lineages, represented by markers with low mutation rates, were shared among species. The central and widespread A. alba retained all ancient lineages whereas other species exhibited fewer, down to a single lineage. In contrast, modern lineages, depicted by markers with high mutation rates, were largely separated among species. The western Mediterranean A. pinsapo and A. numidica were clearly separated from each other and from the remaining Abies species. This indicates the absence of secondary contact. The same scenario applies to the eastern Mediterranean Abies species. An exception is the parapatric complex of A. alba, A. cephalonica, and their supposed hybrid A. borisii regis, which exhibited evidence of secondary contact.  相似文献   

20.
Previous studies showed low selenium (Se) concentrations in Belgian children. Serum α-tocopherol, retinol, total cholesterol, high-density lipoprotein and low-density lipoprotein cholesterol, selenium (Se), and thiobarbituric acid-reactive substances were examined. In order to obtain further information on the Se status in Belgian children, Se, α-tocopherol, retinol, and lipid concentrations were examined and signs of peroxidative lipid damage were evaluated in a subgroup. The study was performed in 524 children (0–14 yr old) during vaccination campaigns. Three age groups were analyzed: 0–1, 1–4, and 4–14 yr. In 87 of them, where sufficient amounts of serum were available, analysis of thiobarbituric acid-reactive substances was done. Infants have high serum α-tocopherol concentrations: (23.2 μmol/L [median and interquartile range: 18.6–30.2]) and low Se concentrations (0.37 mol/L [0.27–0.47]). Se concentrations rise significantly during the first 4 yr (p < 0.0001) (Mann-Whitney U-test, tied p-values): 0.70 μmol/L (0.59–0.82); in the 4–14 yr olds, it was 0.75 μmol/L (0.67–0.86). These values remain low compared to results coming from other parts of the world. α-Tocopherol concentrations decrease significantly after infancy (p < 0.0001). The ratio α-tocopherol/total cholesterol is higher in infants. This is induced by the high vitamin E content of infant formulas. Signs of serum lipid peroxidation could not be detected by analysis of serum malondialdehyde concentrations. High α-tocopherol concentrations, as those observed in infant serum lipids, could be one of the protective mechanisms from the peroxidative lipid damages, sometimes observed in a low-Se status.  相似文献   

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