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51.
One of the limitations of the use of phage antibody libraries in high throughput selections is the production of sufficient phage antibody library at the appropriate quality. Here, we successfully adapt a bioreactor-based protocol for the production of phage peptide libraries to the production of phage antibody libraries. The titers obtained in the stirred-tank bioreactor are 4 to 5 times higher than in a standard shake flask procedure, and the quality of the phage antibody library produced is indistinguishable to that produced using standard procedures as assessed by Western blotting and functional selections. Availability of this protocol will facilitate the use of phage antibody libraries in high-throughput scale selections. 相似文献
52.
D Deprez J Fransen M Lenoir RM Philippaerts R Vaeyens 《Biology of sport / Institute of Sport》2015,32(1):65-70
The aim of the study was to investigate test reliability of the Yo-Yo intermittent recovery test level 1 (YYIR1) in 36 high-level youth soccer players, aged between 13 and 18 years. Players were divided into three age groups (U15, U17 and U19) and completed three YYIR1 in three consecutive weeks. Pairwise comparisons were used to investigate test reliability (for distances and heart rate responses) using technical error (TE), coefficient of variation (CV), intra-class correlation (ICC) and limits of agreement (LOA) with Bland-Altman plots. The mean YYIR1 distances for the U15, U17 and U19 groups were 2024 ± 470 m, 2404 ± 347 m and 2547 ± 337 m, respectively. The results revealed that the TEs varied between 74 and 172 m, CVs between 3.0 and 7.5%, and ICCs between 0.87 and 0.95 across all age groups for the YYIR1 distance. For heart rate responses, the TEs varied between 1 and 6 bpm, CVs between 0.7 and 4.8%, and ICCs between 0.73 and 0.97. The small ratio LOA revealed that any two YYIR1 performances in one week will not differ by more than 9 to 28% due to measurement error. In summary, the YYIR1 performance and the physiological responses have proven to be highly reliable in a sample of Belgian high-level youth soccer players, aged between 13 and 18 years. The demonstrated high level of intermittent endurance capacity in all age groups may be used for comparison of other prospective young soccer players. 相似文献
53.
Using inbreeding theory as applied to neutral alleles inherited maternally,
we generate expected probability distributions of times to identity by
descent for random pairs of mitochondrial genotypes within a population or
within an entire species characterized by high gene flow. For comparisons
with these expectations, empirical distributions of times to most recent
common ancestry were calculated (by conventional mtDNA clock calibrations)
from mtDNA haplotype distances observed within each of three vertebrate
species--American eels, hardhead catfish, and redwinged blackbirds. These
species were chosen for analysis because census population size in each is
currently large and because both genetic and life-history data are
consistent with the postulate that historical gene flow within these
species has been high. The observed molecular distances among mtDNA
lineages were two to three orders of magnitude lower than predicted from
census sizes of breeding females, suggesting that rate of mtDNA evolution
is decelerated in these species and/or that long-term effective population
size is vastly smaller than present-day population size. Several
considerations point to the latter possibility as most likely. The genetic
structure of any species is greatly influenced by historical demography;
even for species that are currently abundant, mtDNA gene lineages appear to
have been channeled through fairly small numbers of ancestors.
相似文献
54.
Developmental and wound-, cold-, desiccation-, ultraviolet-B-stress-induced modulations in the expression of the petunia zinc finger transcription factor gene ZPT2-2
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van Der Krol AR van Poecke RM Vorst OF Voogt C van Leeuwen W Borst-Vrensen TW Takatsuji H van Der Plas LH 《Plant physiology》1999,121(4):1153-1162
The ZPT2-2 gene belongs to the EPF gene family in petunia (Petunia hybrida), which encodes proteins with TFIIIA-type zinc-finger DNA-binding motifs. To elucidate a possible function for ZPT2-2, we analyzed its pattern of expression in relation to different developmental and physiological stress signals. The activity of the ZPT2-2 promoter was analyzed using a firefly luciferase (LUC) reporter gene, allowing for continuous measurements of transgene activity in planta. We show that ZPT2-2::LUC is active in all plant tissues, but is strongly modulated in cotyledons upon germination, in leaves in response to desiccation, cold treatment, wounding, or ultraviolet-B light, and in petal tissue in response to pollination of the stigma. Analysis of mRNA levels indicated that the modulations in ZPT2-2::LUC expression reflect modulations in endogenous ZPT2-2 gene expression. The change in ZPT2-2::LUC activity by cold treatment, wounding, desiccation, and ultraviolet-B light suggest that the phytohormones ethylene and jasmonic acid are involved in regulating the expression of ZPT2-2. Although up-regulation of expression of ZPT2-2 can be blocked by inhibitors of ethylene perception, expression in plants is not induced by exogenously applied ethylene. The application of jasmonic acid does result in an up-regulation of gene activity and, thus, ZPT2-2 may play a role in the realization of the jasmonic acid hormonal responses in petunia. 相似文献
55.
Fredrik RM Huss Erika Nyman Carl-Johan Gustafson Katrin Gisself?lt Elisabeth Liljensten Gunnar Kratz 《Organogenesis》2008,4(3):195-200
Full thickness skin wounds in humans heal with scars, but without regeneration of the dermis. A degradable poly(urethane urea) scaffold (PUUR), Artelon® is already used to reinforce soft tissues in orthopaedics, and for treatment of osteoarthritis of the hand, wrist and foot. In this paper we have done in vitro experiments followed by in vivo studies to find out whether the PUUR is biocompatible and usable as a template for dermal regeneration. Human dermal fibroblasts were cultured on discs of PUUR, with different macrostructures (fibrous and porous). They adhered to and migrated into the scaffolds, and produced collagen. The porous scaffold was judged more suitable for clinical applications and 4 mm Ø, 2 mm-thick discs of porous scaffold (12% w/w or 9% w/w polymer solution) were inserted intradermally in four healthy human volunteers. The implants were well tolerated and increasing ingrowth of fibroblasts was seen over time in all subjects. The fibroblasts stained immunohistochemically for procollagen and von Willebrand factor, indicating neocollagenesis and angiogenesis within the scaffolds. The PUUR scaffold may be a suitable material to use as a template for dermal regeneration.Key words: dermal regeneration, tissue engineering, polymer scaffold, wound healing, in vitro, in vivo, guided tissue regeneration, human, burns 相似文献
56.
Differential inhibition of cytosolic PEPCK by substrate analogues. Kinetic and structural characterization of inhibitor recognition 总被引:1,自引:0,他引:1
The mechanisms of molecular recognition of phosphoenolpyruvate (PEP) and oxaloacetate (OAA) by cytosolic phosphoenolpyruvate carboxykinase (cPEPCK) were investigated by the systematic evaluation of a variety of PEP and OAA analogues as potential reversible inhibitors of the enzyme against PEP. The molecules that inhibit the enzyme in a competitive fashion were found to fall into two general classes. Those molecules that mimic the binding geometry of PEP, namely phosphoglycolate and 3-phosphonopropionate, are found to bind weakly (millimolar Ki values). In contrast, those competitive inhibitors that mimic the binding of OAA (oxalate and phosphonoformate) coordinate directly to the active site manganese ion and bind an order of magnitude more tightly (micromolar Ki values). The competitive inhibitor sulfoacetate is found to be an outlier of these two classes, binding in a hybrid fashion utilizing modes of recognition of both PEP and OAA in order to achieve a micromolar inhibition constant in the absence of direct coordination to the active site metal. The kinetic studies in combination with the structural characterization of the five aforementioned competitive inhibitors demonstrate the molecular requirements for high affinity binding of molecules to the active site of the enzyme. These features include cis-planar carbonyl groups that are required for coordination to the active site metal, a bridging electron rich atom at the position corresponding to the C2 methylene group of OAA to facilitate interactions with R405, a carboxylate or sulfonate moiety at a position corresponding to the C1 carboxylate of OAA, and the edge-on aromatic interaction between a carboxylate and Y235. 相似文献
57.
Andy?Pang Andrew?D?Smith Paulo?AS?Nuin Elisabeth?RM?TillierEmail author 《BMC bioinformatics》2005,6(1):236
Background
General protein evolution models help determine the baseline expectations for the evolution of sequences, and they have been extensively useful in sequence analysis and for the computer simulation of artificial sequence data sets. 相似文献58.
Christopher Uhlig Pedro L Silva Débora Ornellas Raquel S Santos Paulo J Miranda Peter M Spieth Thomas Kiss Michael Kasper B?rbel Wiedemann Thea Koch Marcelo M Morales Paolo Pelosi Marcelo Gama de Abreu Patricia RM Rocco 《Respiratory research》2014,15(1):56
Introduction
We investigated the effects of intravenous and intratracheal administration of salbutamol on lung morphology and function, expression of ion channels, aquaporin, and markers of inflammation, apoptosis, and alveolar epithelial/endothelial cell damage in experimental pulmonary (p) and extrapulmonary (exp) mild acute respiratory distress syndrome (ARDS).Methods
In this prospective randomized controlled experimental study, 56 male Wistar rats were randomly assigned to mild ARDS induced by either intratracheal (n = 28, ARDSp) or intraperitoneal (n = 28, ARDSexp) administration of E. coli lipopolysaccharide. Four animals with no lung injury served as controls (NI). After 24 hours, animals were anesthetized, mechanically ventilated in pressure-controlled mode with low tidal volume (6 mL/kg), and randomly assigned to receive salbutamol (SALB) or saline 0.9% (CTRL), intravenously (i.v., 10 μg/kg/h) or intratracheally (bolus, 25 μg). Salbutamol doses were targeted at an increase of ≈ 20% in heart rate. Hemodynamics, lung mechanics, and arterial blood gases were measured before and after (at 30 and 60 min) salbutamol administration. At the end of the experiment, lungs were extracted for analysis of lung histology and molecular biology analysis. Values are expressed as mean ± standard deviation, and fold changes relative to NI, CTRL vs. SALB.Results
The gene expression of ion channels and aquaporin was increased in mild ARDSp, but not ARDSexp. In ARDSp, intravenous salbutamol resulted in higher gene expression of alveolar epithelial sodium channel (0.20 ± 0.07 vs. 0.68 ± 0.24, p < 0.001), aquaporin-1 (0.44 ± 0.09 vs. 0.96 ± 0.12, p < 0.001) aquaporin-3 (0.31 ± 0.12 vs. 0.93 ± 0.20, p < 0.001), and Na-K-ATPase-α (0.39 ± 0.08 vs. 0.92 ± 0.12, p < 0.001), whereas intratracheal salbutamol increased the gene expression of aquaporin-1 (0.46 ± 0.11 vs. 0.92 ± 0.06, p < 0.001) and Na-K-ATPase-α (0.32 ± 0.07 vs. 0.58 ± 0.15, p < 0.001). In ARDSexp, the gene expression of ion channels and aquaporin was not influenced by salbutamol. Morphological and functional variables and edema formation were not affected by salbutamol in any of the ARDS groups, regardless of the route of administration.Conclusion
Salbutamol administration increased the expression of alveolar epithelial ion channels and aquaporin in mild ARDSp, but not ARDSexp, with no effects on lung morphology and function or edema formation. These results may contribute to explain the negative effects of β2-agonists on clinical outcome in ARDS. 相似文献59.
60.
Responses of acutely isolated neurons from the rostral nucleus of the
solitary tract (rNST) to GABA receptor agonists and antagonists were
investigated using whole-cell recording in current clamp mode. The isolated
neurons retain their morphology and can be divided into multipolar,
elongate and ovoid cell types. Most rNST neurons (97%), including all three
cell types, respond to GABA with membrane hyperpolarization and a reduction
in input resistance. The GABA(A) receptor agonist muscimol reduces neuronal
input resistance in a concentration-dependent manner, whereas the GABA(B)
receptor agonist baclofen had no effect on any of the neurons tested. The
GABA and muscimol reversal potentials were both found to be -75 mV Both the
GABA competitive antagonist picrotoxin and the GABA(A) receptor antagonist
bicuculline block the effect of GABA in a concentration-dependent manner.
These results suggest that GABA activates all neurons in the rNST and that
inhibitory synaptic activity is important in brainstem processing of
gustatory and somatosensory information.
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