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1.
Plasmonics - This study shows development of highly sensitive and stable localized surface plasmon resonance (LSPR)-active U-bent glass and polymeric optical fiber (GOF and POF) sensor probes by a...  相似文献   
2.
Background: To analyse the post-partum concentrations of intra- and extra-cellular blood antioxidants in women with uncomplicated pregnancies.

Methods: Whole blood and plasma thiols, plasma vitamin E and C, serum cholesterol and triglyceride, ferric reducing ability of plasma (FRAP) concentrations were compared between women delivered by caesarean section (n=17) or spontaneous delivery (n=10). A repeated mixed model was used for statistical analysis.

Results: The majority of whole blood thiols increased significantly in both groups the first days post-partum. However, within the caesarean group free cysteine, oxidised cysteine, homocysteine and glutathione and plasma cysteine and homocysteine levels dropped significantly after 24 h, while FRAP levels peaked significantly in this group. Plasma vitamin E levels decreased significantly in both groups within 24 to 48 h after delivery. Independent of the way of delivery whole blood and plasma thiols were significantly increased and vitamin E levels were significantly decreased 3 months post-partum while plasma vitamin C levels and FRAP were unchanged compared to ante-partum levels.

Discussion: Decreased plasma vitamin E levels shortly post-partum are associated with decreased lipid peroxidation. The 24 h post-partum drop of some plasma and whole blood thiols in the caesarean group may be due to prolonged fasting.  相似文献   
3.
Mouse embryos genetically null for all alphav integrins develop intracerebral hemorrhage owing to defective interactions between blood vessels and brain parenchymal cells. Here, we have used conditional knockout technology to address whether the cerebral hemorrhage is due to primary defects in vascular or neural cell types. We show that ablating alphav expression in the vascular endothelium has no detectable effect on cerebral blood vessel development, whereas deletion of alphav expression in central nervous system glial cells leads to embryonic and neonatal cerebral hemorrhage. Conditional deletion of alphav integrin in both central nervous system glia and neurons also leads to cerebral hemorrhage, but additionally to severe neurological defects. Approximately 30% of these mutants develop seizures and die by 4 weeks of age. The remaining mutants survive for several months, but develop axonal deterioration in the spinal cord and cerebellum, leading to ataxia and loss of hindlimb coordination. Collectively, these data provide evidence that alphav integrins on embryonic central nervous system neural cells, particularly glia, are necessary for proper cerebral blood vessel development, and also reveal a novel function for alphav integrins expressed on axons in the postnatal central nervous system.  相似文献   
4.
Lipopolysaccharides (LPS; endotoxin) activate immunocompetent cells of the host via a transmembrane signaling process. In this study, we investigated the function of the LPS-binding protein (LBP) in this process. The cytoplasmic membrane of the cells was mimicked by lipid liposomes adsorbed on mica, and the lateral organization of LBP in these membranes and its interaction with LPS aggregates were characterized by atomic force microscopy. Using cantilever tips functionalized with anti-LBP antibodies, single LBP molecules were localized in the membrane at low concentrations. At higher concentrations, LBP formed clusters of several molecules and caused cross-linking of lipid bilayers. The addition of LPS to LBP-containing liposomes led to the formation of LPS domains in the membranes, which could be inhibited by anti-LBP antibodies. Thus, LBP mediates the fusion of lipid membranes and LPS aggregates.  相似文献   
5.
Lipid-specific membrane activity of human beta-defensin-3   总被引:2,自引:0,他引:2  
Defensins represent a major component of innate host defense against bacteria, fungi, and enveloped viruses. One potent defensin found, e.g., in epithelia, is the polycationic human beta-defensin-3 (hBD3). We investigated the role of the lipid matrix composition, and in particular the presence of negatively charged lipopolysaccharides (LPS) from sensitive (Escherichia coli, Salmonella enterica serovar Minnesota) or resistant (Proteus mirabilis) Gram-negative bacteria or of the zwitterionic phospholipids of human cells, in determining the action of polycationic hBD3 on the different membranes, and related to their biological activity. The main focus was directed on data derived from electrical measurements on a reconstitution system of the OM as a planar asymmetric bilayer composed on one side of LPS and on the other of a phospholipid mixture. Our results demonstrate that the antimicrobial activity and the absence of cytotoxicity can be explained by the lipid-specificity of the peptide. A clear correlation between these aspects of the biological activity of hBD3 and its interaction with lipid matrices could be found. In particular, hBD3 could only induce lesions in those membranes resembling the lipid composition of the OM of sensitive bacterial strains. The permeation through the membrane is a decisive first step for the biological activity of many antimicrobial peptides. Therefore, we propose that the lipid-specificity of hBD3 as well as some other membrane-active antimicrobial peptides is important for their activity against bacteria or mammalian cells.  相似文献   
6.
A novel actinomycete, strain HMC10T, was isolated from a soil sample taken from the banks of the Gamka River in the Swartberg Nature Reserve, Western Cape Province, South Africa. Strain HMC10T was identified as a member of the genus Nonomuraea by a polyphasic approach. Strain HMC10T could be differentiated from other members of the genus Nonomuraea on the basis of physiology and 16S rRNA gene sequence analysis. DNA-DNA hybridization further differentiated strain HMC10T from its nearest phylogenetic neighbour, Nonomuraea turkmeniaca NRRL B-16246T (4.5 ± 3.8% DNA relatedness). Strain HMC10T exhibited weak antibiosis against Mycobacterium aurum A+, but none against Mycobacterium tuberculosis H37RvT. The name Nonomuraea candida is proposed, with the type strain HMC10T (= DSM 45086T = NRRL B-24552T). The GenBank accession number for the 16S rRNA gene sequence of Nonomuraea candida HMC10T is DQ285421.  相似文献   
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8.

Background  

Common structural biology methods (i.e., NMR and molecular dynamics) often produce ensembles of molecular structures. Consequently, averaging of 3D coordinates of molecular structures (proteins and RNA) is a frequent approach to obtain a consensus structure that is representative of the ensemble. However, when the structures are averaged, artifacts can result in unrealistic local geometries, including unphysical bond lengths and angles.  相似文献   
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10.
Nonproductively rearranged H and L chain loci of B cell hybridoma lines expressing heavily mutated antibodies were cloned and partially sequenced. The results confirm earlier data showing that somatic point mutations are as frequent in nonproductively rearranged loci containing a rearranged V gene as in productively rearranged loci. They establish in addition that in nonproductive H chain loci which bear a DJH rearrangement the frequency of somatic mutations is more than 10 times lower (0.2%) than in VDJH loci expressed by the same cells (2.5%). Thus, the hypermutation mechanism operating in B cell differentiation is targeted at V genes rearranged to the J locus and may require nucleotide sequences associated with both V and J elements in order to be fully activated. An inversion of the JH2 segment was detected in one DJH locus. This inversion appears to be the result of a secondary joining event occurring occasionally in the course of B cell development.  相似文献   
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