21 resultados para Immunoglobulin Fab Fragments -- isolation

em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain


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Genes of interest can be targeted specifically to respiratory epithelial cells in intact animals with high efficiency by exploiting the receptor-mediated endocytosis of the polymeric immunoglobulin receptor. A DNA carrier, consisting of the Fab portion of polyclonal antibodies raised against rat secretory component covalently linked to poly-L-lysine, was used to introduce plasmids containing different reporter genes into airway epithelial cells in vivo. We observed significant levels of luciferase enzyme activity in protein extracts from the liver and lung, achieving maximum values of 13,795 +/- 4,431 and 346,954 +/- 199,120 integrated light units (ILU) per milligram of protein extract, respectively. No luciferase activity was detected in spleen or heart, which do not express the receptor. Transfections using complexes consisting of an irrelevant plasmid (pCMV lacZ) bound to the bona fide carrier or the expression plasmid (pGEMluc) bound to a carrier based on an irrelevant Fab fragment resulted in background levels of luciferase activity in all tissues examined. Thus, only tissues that contain cells bearing the polymeric immunoglobulin receptor are transfected, and transfection cannot be attributed to the nonspecific uptake of an irrelevant carrier-DNA complex. Specific mRNA from the luciferase gene was also detected in the lungs of transfected animals. To determine which cells in the lungs are transfected by this method, DNA complexes were prepared containing expression plasmids with genes encoding the bacterial beta-galactosidase or the human interleukin 2 receptor. Expression of these genes was localized to the surface epithelium of the airways and the submucosal glands, and not the bronchioles and alveoli. Receptor-mediated endocytosis can be used to introduce functional genes into the respiratory epithelium of rats, and may be a useful technique for gene therapy targeting the lung.

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El anlisis de los ensayos de John Tyndall, Fragments of Science, permite identificar la teora atmica, el principio de conservacin de la energa y el evolucionismo darwinista como los elementos constitutivos del andamiaje terico del naturalismo cientfico. As, en su ensayo On the Study of Physics se resumen sus brillantes facetas como educador y divulgador cientfico, desarrolladas fundamentalmente en el seno de la Royal Institution. En la lectura On Force, Tyndall da por finalizada la controversia Joule- Mayer sobre la primaca del descubrimiento del principio de conservacin de la energa, a la vez que plantea algunas de las claves de la lucha por el liderazgo en el seno de la comunidad cientfica. El discurso presidencial ante la British Association de 1874 en Belfast ejemplifica el coraje de Tyndall en su empeo por demarcar los territorios de la ciencia y la religin, a la luz de los nuevos desafos cientficos. En el trasfondo subyacen los procesos de secularizacin de la sociedad y de profesionalizacin de una comunidad cientfica heterognea. El compromiso cvico que Tyndall demuestra en The Belfast Address es digno corolario de una vida y obra que permite situarlo como paradigma de lo que, en la terminologa de Turner, se ha dado en denominar cientfico pblico.

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Two experiments were performed to determine the best strategy of use of the product TRACTcare 4P (ITPSA) (TC, specific immunoglobulin-rich egg yolk powder within an energetic fatty acid matrix) in piglets from weaning and for 6 weeks, in diets without or with inclusion of antibiotics. Each trial was performed with 144 piglets in 24 pens, in a completely randomized design blocked by initial body weight. Feeds were formulated according to animal requirements in two periods. In the first trial no antibiotics were included in the feeds and no room disinfection from previous trial was performed; treatments were: 1) Negative control (NC); 2) NC+TC on top of the feed within the hopper for the first 3 days on trial (30 g/pigday), and eventually if diarrhea appeared (TCOT); 3) NC+TC ad libitum provided in an extra hopper within the pen (TCAL); and 4) NC+TC at 5 g/kg added to the feed in the mixer (TC5). In the second trial, treatments were: 1) Positive control: basal diet that included 250 mg/kg amoxiciline (BD)+100 mg/kg colistine (AC); 2) BD+2 g/kg TC (TC2A); 3) BD+5 g/kg TC (TC5A); and 4) BD+8 g/kg TC (TC8A). In diets without antibiotics, the product TC at 5 g/kg in the feed numerically improved BW by 8% compared to Control animals, while G:F was almost identical between both groups. When antibiotics were used in the feed, replacement of colistin at 100 mg/kg for TC at 2 g/kg in feed numerically improved the performance compared to Positive control animals (for the whole trial period ADG 8% better: 390 g vs. 361 g; G:F 1% better: 0.748 kg/kg vs. 0.742 kg/kg), possibly due to the stimulation of feed consumption at weaning. In both trials, the lower number of dead and culled animals from TC5 and TC2A together with higher BW represented an advantage over Control treatments of 6% to 10% animals more and 15% to 17% total BW more at the end of the trial.

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Morphological descriptors are practical and essential biomarkers for diagnosis andtreatment selection for intracranial aneurysm management according to the current guidelinesin use. Nevertheless, relatively little work has been dedicated to improve the three-dimensionalquanti cation of aneurysmal morphology, automate the analysis, and hence reduce the inherentintra- and inter-observer variability of manual analysis. In this paper we propose a methodologyfor the automated isolation and morphological quanti cation of saccular intracranial aneurysmsbased on a 3D representation of the vascular anatomy.

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Stress in local isolation structures is studied by microRaman spectroscopy. The results are correlated with predictions of an analytical model for the stress distribution and with crosssectional transmission electron microscopy observations. The measurements are performed on structures on which the Si3N4 oxidation mask is still present. The influence of the pitch of the periodic local isolation pattern, consisting of parallel lines, the thickness of the mask, and the length of the bird"s beak on the stress distribution are studied. It is found that compressive stress is present in the Si substrate under the center of the oxidation mask lines, with a magnitude dependent on the width of the lines. Large tensile stress is concentrated under the bird"s beak and is found to increase with decreasing length of the bird"s beak and with increasing thickness of the Si3N4 film.

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Adenoviruses of primates include human (HAdV) and simian (SAdV) isolates classified into 8 species (Human Adenovirus A to G, and Simian Adenovirus A). In this study, a novel adenovirus was isolated from a colony of cynomolgus macaques (Macaca fascicularis) and subcultured in VERO cells. Its complete genome was purified and a region encompassing the hexon gene, the protease gene, the DNA binding protein (DBP) and the 100 kDa protein was amplified by PCR and sequenced by primer walking. Sequence analysis of these four genes showed that the new isolate had 80% identity to other primate adenoviruses and lacked recombination events. The study of the evolutionary relationships of this new monkey AdV based on the combined sequences of the four genes supported a close relationship to SAdV-3 and SAdV-6, lineages isolated from Rhesus monkeys. The clade formed by these three types is separated from the remaining clades and establishes a novel branch that is related to species HAdV-A, F and G. However, the genetic distance corresponding to the newly isolated monkey AdV considerably differs from these as to belong to a new, not yet established species. Results presented here widen our knowledge on SAdV and represents an important contribution to the understanding of the evolutionary history of primate adenoviruses.

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Adenoviruses of primates include human (HAdV) and simian (SAdV) isolates classified into 8 species (Human Adenovirus A to G, and Simian Adenovirus A). In this study, a novel adenovirus was isolated from a colony of cynomolgus macaques (Macaca fascicularis) and subcultured in VERO cells. Its complete genome was purified and a region encompassing the hexon gene, the protease gene, the DNA binding protein (DBP) and the 100 kDa protein was amplified by PCR and sequenced by primer walking. Sequence analysis of these four genes showed that the new isolate had 80% identity to other primate adenoviruses and lacked recombination events. The study of the evolutionary relationships of this new monkey AdV based on the combined sequences of the four genes supported a close relationship to SAdV-3 and SAdV-6, lineages isolated from Rhesus monkeys. The clade formed by these three types is separated from the remaining clades and establishes a novel branch that is related to species HAdV-A, F and G. However, the genetic distance corresponding to the newly isolated monkey AdV considerably differs from these as to belong to a new, not yet established species. Results presented here widen our knowledge on SAdV and represents an important contribution to the understanding of the evolutionary history of primate adenoviruses.

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Presentaci de tres bronzes de carcter jurdic procedents un d'ells d'Hellin i els altres probablement de la Btica. El primer sembla sser una limitatio o una adsignatio. El segon sembla correspondre a un passatge d'una llei d'poca flvia, i el tercer s, probablement, una adsignatio.

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Unassembled immunoglobulin light chains expressed by the mouse plasmacytoma cell line NS1 (KNS1) are degraded in vivo with a half-life of 50-60 min in a way that closely resembles endoplasmic reticulum (ER)-associated degradation (Knittler et al., 1995). Here we show that the peptide aldehydes MG132 and PS1 and the specific proteasome inhibitor lactacystin effectively increased the half-life of KNS1, arguing for a proteasome-mediated degradation pathway. Subcellular fractionation and protease protection assays have indicated an ER localization of KNS1 upon proteasome inhibition. This was independently confirmed by the analysis of the folding state of KNS1and size fractionation experiments showing that the immunoglobulin light chain remained bound to the ER chaperone BiP when the activity of the proteasome was blocked. Moreover, kinetic studies performed in lactacystin-treated cells revealed a time-dependent increase in the physical stability of the BiP-KNS1complex, suggesting that additional proteins are present in the older complex. Together, our data support a model for ER-associated degradation in which both the release of a soluble nonglycosylated protein from BiP and its retrotranslocation out of the ER are tightly coupled with proteasome activity.

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Previous studies have reported that a diet containing 10% cocoa, a rich source of flavonoids, has immunomodulatory effects on rats and, among others effects, is able to attenuate the immunoglobulin (Ig) synthesis in both systemic and intestinal compartments. The purpose of the present study was focused on investigating whether these effects were attributed exclusively to the flavonoid content or to other compounds present in cocoa. To this end, eight-week-old Lewis rats were fed, for two weeks, either a standard diet or three isoenergetic diets containing increasing proportions of cocoa flavonoids from different sources: one with 0.2% polyphenols from conventional defatted cocoa, and two others with 0.4% and 0.8% polyphenols, respectively, from non-fermented cocoa. Diet intake and body weight were monitored and fecal samples were obtained throughout the study to determine fecal pH, IgA, bacteria proportions, and IgA-coated bacteria. Moreover, IgG and IgM concentrations in serum samples collected during the study were quantified. At the end of the dietary intervention no clear changes of serum IgG or IgM concentrations were quantified, showing few effects of cocoa polyphenol diets at the systemic level. However, in the intestine, all cocoa polyphenol-enriched diets attenuated the age-related increase of both fecal IgA and IgA-coated bacteria, as well as the proportion of bacteria in feces. As these effects were not dependent on the dose of polyphenol present in the diets, other compounds and/or the precise polyphenol composition present in cocoa raw material used for the diets could be key factors in this effect.

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Background: Myotragus balearicus was an endemic bovid from the Balearic Islands (Western Mediterranean) that became extinct around 6,000-4,000 years ago. The Myotragus evolutionary lineage became isolated in the islands most probably at the end of the Messinian crisis, when the desiccation of the Mediterranean ended, in a geological date established at 5.35 Mya. Thus, the sequences of Myotragus could be very valuable for calibrating the mammalian mitochondrial DNA clock and, in particular, the tree of the Caprinae subfamily, to which Myotragus belongs. Results: We have retrieved the complete mitochondrial cytochrome b gene (1,143 base pairs), plus fragments of the mitochondrial 12S gene and the nuclear 28S rDNA multi-copy gene from a well preserved Myotragus subfossil bone. The best resolved phylogenetic trees, obtained with the cytochrome b gene, placed Myotragus in a position basal to the Ovis group. Using the calibration provided by the isolation of Balearic Islands, we calculated that the initial radiation of caprines can be dated at 6.2 0.4 Mya. In addition, alpine and southern chamois, considered until recently the same species, split around 1.6 0.3 Mya, indicating that the two chamois species have been separated much longer than previously thought. Conclusion: Since there are almost no extant endemic mammals in Mediterranean islands, the sequence of the extinct Balearic endemic Myotragus has been crucial for allowing us to use the Messinian crisis calibration point for dating the caprines phylogenetic tree.

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Lamellarins are a large family of marine alkaloids with potential anticancer activity that have been isolated from diverse marine organisms, mainly ascidians and sponges. All lamellarins feature a 3,4-diarylpyrrole system. Pentacyclic lamellarins, whose polyheterocyclic system has a pyrrole core, are the most active compounds. Some of these alkaloids are potently cytotoxic to various tumor cell lines. To date, Lam-D and Lam-H have been identified as lead compounds for the inhibition of topoisomerase I and HIV-1 integrase, respectively nuclear enzymes which are over-expressed in deregulation disorders. Moreover,these compounds have been reported for their efficacy in treatment of multi-drug resistant (MDR) tumors cells without mediated drug efflux, as well as their immunomodulatory activity and selectivity towards melanoma cell lines. This article is an overview of recent literature on lamellarins, encompassing their isolation, recent synthetic strategies for their total synthesis, the preparation of their analogs, studies on their mechanisms of action, and their structure-activity relationships (SAR).

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Barmumycin was isolated from an extract of the marine actinomycete Streptomyces sp. BOSC-022A and found to be cytotoxic against various human tumor cell lines. Based on preliminary one- and two-dimensional 1H- and 13C-NMR spectra, the natural compound was initially assigned the structure of macrolactone-type compound 1, which was later prepared by two different routes. However, major spectroscopic differences between isolated barmumycin and 1 led to revision of the proposed structure as E-16. Based on synthesis of this new compound, and subsequent spectroscopic comparison of it to an authentic sample of barmumycin, the structure of the natural compound was indeed confirmed as that of E-16.

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Aculeacin A is a lipopeptide that inhibits ,B-glucan synthesis in yeasts. A number of Saccharomyces cerevisiae mutants resistant to this antibiotic were isolated, and four loci (ACRI, ACR2, ACR3, and ACR4) whose products are involved in the sensitivity to aculeacin A of yeast ceils were defined. Mutants containing mutations in the four loci were also resistant to echinocandin B, another member of this lipopeptide family of antibiotics. In contrast, acri, acr3, and acr4 mutants were resistant to papulacandin B (an antibiotic containing a disaccharide linked to two fatty acid chains that also inhibits P-glucan synthesis), but acr2 mutants were susceptible'to this antibiotic. This result defines common and specific steps in the entry and action of aculeacin A and papulacandin B. The analysis of double mutants revealed an epistatic effect of the acr2 mutation on the other three mutations. Cell walls of the four different mutants did not show significant alterations in composition with respect to the parental strain, and in vitro glucan synthase activity was also unaffected. However, cell surface hydrophobicity in three of the mutants was considerably decreased with respect to the parental strain.