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91.
Zack Frehlick Harvey Lui David I. McLean Shuo Tang Haishan Zeng 《Journal of biophotonics》2013,6(4):305-309
We present a multimodal in vivo skin imaging instrument that is capable of simultaneously acquiring multiphoton and reflectance confocal images at up to 27 frames per second with 256 × 256 pixel resolution without the use of exogenous contrast agents. A single femtosecond laser excitation source is used for all channels ensuring perfect image registration between the two‐photon fluorescence (TPF), second harmonic generation (SHG), and reflectance confocal microscopy (RCM) images. Images and videos acquired with the system show that the three imaging channels provide complementary information in in vivo human skin measurements. In the epidermis, cell boundaries are clearly seen in the RCM channel, while cytoplasm is better seen in the TPF imaging channel, whereas in the dermis, SHG and TPF channels show collagen bundles and elastin fibers, respectively. The demonstrated fast imaging speed and multimodal imaging capabilities of this MPM/RCM instrument are essential features for future clinical application of this technique. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
92.
VanLoock MS Agrawal RK Gabashvili IS Qi L Frank J Harvey SC 《Journal of molecular biology》2000,304(4):507-515
The ribosome undergoes pronounced periodic conformational changes during protein synthesis. Of particular importance are those occurring around the decoding site, the region of the 16 S rRNA interacting with the mRNA-(tRNA)(2) complex. We have incorporated structural information from X-ray crystallography and nuclear magnetic resonance into cryo-electron microscopic maps of ribosomal complexes designed to capture structural changes at the translocation step of the polypeptide elongation cycle. The A-site region of the decoding site actively participates in the translocation of the tRNA from the A to the P-site upon GTP hydrolysis by elongation factor G, shifting approximately 8 A toward the P-site. This implies that elongation factor G actively pushes both the decoding site and the mRNA/tRNA complex during translocation. 相似文献
93.
Chavan SS Huerta PT Robbiati S Valdes-Ferrer S Ochani M Dancho M Frankfurt M Volpe BT Tracey KJ Diamond B 《Molecular medicine (Cambridge, Mass.)》2012,18(9):930-937
Severe sepsis, a syndrome that complicates infection and injury, affects 750,000 annually in the United States. The acute mortality rate is approximately 30%, but, strikingly, sepsis survivors have a significant disability burden: up to 25% of survivors are cognitively and physically impaired. To investigate the mechanisms underlying persistent cognitive impairment in sepsis survivors, here we developed a murine model of severe sepsis survivors following cecal ligation and puncture (CLP) to study cognitive impairments. We observed that serum levels of high mobility group box 1 (HMGB1), a critical mediator of acute sepsis pathophysiology, are increased in sepsis survivors. Significantly, these levels remain elevated for at least 4 wks after CLP. Sepsis survivors develop significant, persistent impairments in learning and memory, and anatomic changes in the hippocampus associated with a loss of synaptic plasticity. Administration of neutralizing anti-HMGB1 antibody to survivors, beginning 1 wk after onset of peritonitis, significantly improved memory impairments and brain pathology. Administration of recombinant HMGB1 to na?ve mice recapitulated the memory impairments. Together, these findings indicate that elevated HMGB1 levels mediate cognitive decline in sepsis survivors, and suggest that it may be possible to prevent or reverse cognitive impairments in sepsis survivors by administration of anti-HMGB1 antibodies. 相似文献
94.
Summary An anaerobic hybrid reactor was used in the anaerobic treatment of an acidic petrochemical effluent. An organic loading rate of 20.04 kg COD/(m3d) at a HRT of 17 hours was obtained with a volatile fatty acid removal of 91%, and COD removal of 84%. A final reactor effluent containing 44 mg/l ammonia nitrogen and 12.3 mg/l PO4-P was produced. 相似文献
95.
The complete primary structure of the human snRNP E protein. 总被引:4,自引:2,他引:4
D R Stanford M Kehl C A Perry E L Holicky S E Harvey A M Rohleder K Rehder Jr R Luhrmann E D Wieben 《Nucleic acids research》1988,16(22):10593-10605
The snRNP E protein is one of four "core" proteins associated with the snRNAs of the U family (U1,U2,U4,U5, and U6). Screening of a human teratoma cDNA library with a partial cDNA for a human autoimmune antigen resulted in the isolation of a cDNA clone containing the entire coding region of this snRNP core protein. Comparison of the 5' end of this cDNA with the sequences of two processed pseudogenes and primer extension data suggest that the cDNA is nearly full length. The longest open reading frame in this clone codes for a basic 92 amino acid protein which is in perfect agreement with amino acid sequence data obtained from purified E protein. The predicted sequence of this protein reveals no extensive similarity to other snRNP proteins, but contains regions of similarity to a eukaryotic ribosomal protein. 相似文献
96.
Phospholipid lamellae are cholesterol carriers in human bile 总被引:2,自引:0,他引:2
G J S?mjen Y Marikovsky E Wachtel P R Harvey R Rosenberg S M Strasberg T Gilat 《Biochimica et biophysica acta》1990,1042(1):28-35
Cholesterol solubility and precipitation in bile are major factors in the pathogenesis of cholesterol gallstones. At present, mixed micelles and phospholipid vesicles are considered to be the only cholesterol carriers in bile. In this study we present evidence showing that phospholipid lamellae are major cholesterol carriers in human bile. Lamellae are a known aggregational form in pure phospholipid model systems. In the present study, lamellae were demonstrated by electron microscopy after negative staining and by small-angle X-ray diffraction in all human gallbladder bile samples examined. During diffraction experiments, cholesterol was found to crystallize from these lamellae. Cholesterol carriers in bile were separated by high-resolution chromatography and by prolonged ultracentrifugation. Lamellae were shown to solubilize most of the biliary cholesterol; vesicles solubilized a lesser amount; while micelles solubilized only a minor portion. Our data suggest that phospholipid aggregates are the main cholesterol carriers in bile. Bile salts may control the equilibrium between the various aggregational forms of cholesterol-carrying phospholipids. 相似文献
97.
Harvey J 《Molecular neurobiology》2003,28(3):245-258
It is well established that the adipocyte-derived hormone leptin is an important circulating satiety factor that regulates
body weight and food intake via its actions on specific hypothalamic nuclei. However, there is growing evidence that leptin
and its receptors are widely expressed throughout the brain, in regions not generally associated with energy homeostasis,
such as cortex, cerebellum, brainstem, basal ganglia, and hippocampus. In this review the author discusses recent advances
made in leptin neurobiology, with particular emphasis on the role of this endocrine peptide in normal and pathophysiological
hippocampal function. 相似文献
98.
Commercial-scale cellulosic ethanol production has been hindered by high costs associated with cellulose-to-glucose conversion and hexose and pentose co-fermentation. Simultaneous saccharification and fermentation (SSF) with a yeast strain capable of xylose and cellobiose co-utilization has been proposed as a possible avenue to reduce these costs. The recently developed DA24-16 strain of Saccharomyces cerevisiae incorporates a xylose assimilation pathway and a cellodextrin transporter (CDT) that permit rapid growth on xylose and cellobiose. In the current work, a mechanistic kinetic model of cellulase-catalyzed hydrolysis of cellulose was combined with a multi-substrate model of microbial growth to investigate the ability of DA24-16 and improved cellobiose-consuming strains to obviate the need for exogenously added β-glucosidase and to assess the impact of cellobiose utilization on SSF and separate hydrolysis and fermentation (SHF). Results indicate that improved CDT-containing strains capable of growing on cellobiose as rapidly as on glucose produced ethanol nearly as rapidly as non-CDT-containing yeast supplemented with β-glucosidase. In producing 75 g/L ethanol, SSF with any strain did not result in shorter residence times than SHF with a 12 h saccharification step. Strains with improved cellobiose utilization are therefore unlikely to allow higher titers to be reached more quickly in SSF than in SHF. 相似文献
99.
David A. Doron David M. Jacobowitz Eliahu Heldman Ciora Feuerstein Harvey B. Pollard John M. Hallenbeck 《In vitro cellular & developmental biology. Animal》1991,27(9):689-697
Summary Microvascular endothelial cells from the adult rat brain were cultured on Matrigel and found to express many differentiated
properties including secretion of prostacyclin (PGI2) and von Willebrand’s factor (vWF). Brain microvascular endothelial cells (BMECs) were purified by dextran and percoll gradients
after enzymatic treatment and cultured under various conditions. BMECs that were plated on Matrigel stained positively for
factor VIII-related antigen and incorporated Di-I-acetylated low density lipoprotein, whereas BMEC plated on fibronectin,
gelatin, or uncoated dishes did not express any of the above properties which are characteristic of endothelial cells. vWF
was measured by a sensitive ELISA in the culture media of BMECs plated on different types of matrices. Specificity of the
anti-human vWF antibodies for the rat vWF was verified by immunoabsorption on a solid phase, sodium dodecyl sulfate, and Western
blot analysis. BMECs also secreted vWF into the culture media only when the cells were plated on Matrigel, and this secretion
was augmented after a 6 h incubation with an interleukin-1 tumor necrosis factor-α mixture, but not by lipopolysaccharide. From different matrices tested, only Matrigel permitted the secretion of PGI2 by BMECs. Cells also proved to be sensitive to mechanical stimulation and became refractory to secretagogue if the mechanical
stimulation was serially repeated. Under the best conditions, stimulation of the cells with bradykinin (1μM) substantially increased PGI2 secretion. These data indicate that growth of BMECs on Matrigel in vitro permits the expression of classical endothelial
cell markers in a manner similar to the behavior of these cells in situ.
Supported by grant 1 RO1 NS2822501 from National Institutes of Health, Bethesda, MD. 相似文献
100.
We describe the characterization of the microalga Glossomastix chrysoplasta, an eicosapentaenoic acid (EPA) producer in the Pinguiophyceae class, Chromophyte division. Growth conditions were selected to optimize algal growth and EPA production. EPA represented up to 30% of the fatty acid content of Glossomastix chrysoplasta, at levels of 22 mg EPA per gram dry weight. Up to 72% of the EPA was produced as glycolipids, components of structural lipids. The optimal growth conditions in continuous culture were found to be greater than 500 micromol photons/m(2) . s light intensity, 0.33/day dilution rate, pH 7.20-7.45, and a temperature of 18-20 degrees C. Macronutrient studies indicated the limiting nutrient to be bicarbonate or dissolved carbon dioxide, and consequently decreasing pH increased EPA production. 相似文献