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Selected AbstractsThe hippocampus and caudomedial neostriatum show selective responsiveness to conspecific song in the female zebra finchDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2002David J. Bailey Abstract The perception of song is vital to the reproductive success of both male and female songbirds. Several neural structures underlying this perception have been identified by examining expression of immediate early genes (IEGs) following the presentation of conspecific or heterospecific song. In the few avian species investigated, areas outside of the circuit for song production contain neurons that are active following song presentation, specifically the caudal hyperstriatum ventrale (cHV) and caudomedial neostriatum (NCM). While studied in detail in the male zebra finch, IEG responses in these neural substrates involved in song perception have not been quantified in females. Therefore, adult female zebra finches were presented with zebra finch song, nonzebra finch song, randomly generated tones, or silence for 30 min. One hour later they were sacrificed, and their brains removed, sectioned, and immunocytochemically processed for FOS expression. Animals exposed to zebra finch song had a significantly higher density of FOS-immunoreactive cells in the NCM than those presented with other songs, tones, or silence. Neuronal activation in the cHV was equivalent in birds that heard zebra finch and non-zebra finch song, expression that was higher than that observed in the groups that heard no song. Interestingly, the hippocampus (HP) and adjacent parahippocampal area (AHP) were activated in a manner comparable to the NCM. These results suggest a general role for the cHV in song perception and a more specific role for the NCM and HP/AHP in facilitating recognition of and responsiveness to species-specific song in female zebra finches. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 43,51, 2002 [source] Subtractive Screening for Probiotic Properties of Lactobacillus Species from the Human Gastrointestinal Tract in the Search for New ProbioticsJOURNAL OF FOOD SCIENCE, Issue 8 2007S. Delgado ABSTRACT:, In the search for new probiotics, 61 Lactobacillus spp. isolates, belonging to 12 species and isolated as dominant lactic acid bacteria from the feces of healthy humans, were subjected to a subtractive system of in vitro analyses, which included desirable and undesirable traits. Twenty-four isolates were able to grow in 2% bovine bile, of which 13 grew in acidified broth at pH 3.5 in acidified cysteine-containing MRS broth. Intrinsic resistance to certain antimicrobial agents (cefoxitin, metronidazole, vancomycin) was observed in most isolates, but atypical resistances to erythromycin, clindamycin, or tetracycline were also found in 5 strains. Undesirable traits such as ,-chymotrypsin or N-acetyl-,-glucosaminidase activities were not detected, but low ,-glucuronidase and moderate ,-glucosidase activities were recorded in 2 strains. Two Lactobacillus gasseri and 2 Lactobacillus paracasei selected strains inhibited several intestinal pathogens in an agar spot test, including strains of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. They also adhered to human Caco-2 and HT-29 epithelial cells in a manner comparable to Lactobacillus rhamnosus strain GG, and were unable to degrade pig gastric mucin in a plate assay. Together, these results suggest these 4 strains to be good probiotic candidates, concluding that the subtractive screening devised in this work could be a valuable tool in large-scale surveys for probiotics. [source] N,N -dimethyl-thioamphetamine and methyl-thioamphetamine, two non-neurotoxic substrates of 5-HT transporters, have scant in vitro efficacy for the induction of transporter-mediated 5-HT release and currentsJOURNAL OF NEUROCHEMISTRY, Issue 5 2008Marco Gobbi Abstract We studied two non-neurotoxic amphetamine derivatives (methyl-thioamphetamine, MTA and N,N- dimethylMTA, DMMTA) interacting with serotonin (5-HT) transporters (SERTs) with affinities comparable to that of p- Cl-amphetamine (pCA). The rank order for their maximal effects in inducing both [3H]5-HT release from rat brain synaptosomes or hSERT-expressing HEK-293 cells, and currents in hSERT-expressing oocytes, was pCA » MTA , DMMTA. A correlation between drug-induced release and currents is also strengthened by the similar bell shape of the dose,response curves. Release experiments indicated that MTA and DMMTA are SERT substrates although MTA is taken up by HEK-293 cells with a Vmax 40% lower than pCA. The weak effects of MTA and DMMTA in vitro might therefore be due to their properties as ,partial substrates' on the mechanisms, other than translocation, responsible for currents and/or release. After either local or systemic in vivo administration, MTA and DMMTA release 5-HT in a manner comparable to pCA. These findings confirm that the neurotoxic properties of some amphetamine derivatives are independent of their 5-HT-releasing activity in vivo. It is worth noting that only those amphetamine derivatives with high efficiency in inducing 5-HT release and currents in vitro have neurotoxic properties. [source] Aggregation and membrane permeabilizing properties of designed histidine-containing cationic linear peptide antibiotics,JOURNAL OF PEPTIDE SCIENCE, Issue 4 2008Arnaud Marquette Abstract Members of the LAH4 family of cationic linear peptide antibiotics have been designed to form amphipathic helical structures in membrane environments and switch from alignments parallel to the bilayer surface to transmembrane orientations in a pH-dependent manner. Here the aggregation in aqueous buffer of two members of the family has been investigated by DLS. The peptides form monomers or small oligomers at pH = 5 but associate into nano-sized aggregates at physiological pH. The diameter of these latter complexes can be considerably reduced by sonication. Furthermore, the membrane interactions of the various supramolecular aggregates with POPC or mixed POPC/POPS vesicles have been investigated in calcein-release assays. In all the cases tested, the large preformed oligomeric peptide aggregates of 20,40 nm in size were more active than the structures with the smallest hydrodynamic radii in releasing the fluorescent dye from LUV. In contrast, the relative activity after sonication depends on the specific environment tested. The data suggest that these amphiphiles form micellar structures and support the notion that they can act in a manner comparable to detergents. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd. [source] Pharmaceutical and immunological evaluation of a single-shot hepatitis B vaccine formulated with PLGA microspheresJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2002Li Shi Abstract A single-shot Hepatitis B vaccine formulation using poly(d,l)-lactide-co-glycolide acid (PLGA) microspheres as a delivery system was examined using a variety of biophysical and biochemical techniques as well as immunological evaluation in C3H mice. PLGA microsphere encapsulation of the Hepatitis B surface antigen (HBsAg), a lipoprotein particle, resulted in good recoveries of protein mass, protein particle conformational integrity, and in vitro antigenicity. Some partial delipidation of the HBsAg, however, was observed. The loading and encapsulation efficiency of HBsAg into the PLGA microspheres were measured along with the morphology and size distribution of the vaccine-loaded PLGA microspheres. The in vitro release kinetics of HBsAg from the PLGA microspheres was evaluated and found to be affected by experimental conditions such as stirring rate. HBsAg showed enhanced storage stability at 37°C in the slightly acidic pH range reported to be found inside PLGA microspheres; thus, the antigen is relatively stable under conditions of temperature and pH that may mimic in vivo conditions. The immunogenicity of the microsphere formulations of HBsAg was compared with conventional aluminum adjuvant formulated HBsAg vaccine in C3H mice. Comparisons were made between aluminum formulations (one and two injections), PLGA microsphere formulations (single injection), and a mixture of aluminum and PLGA microsphere formulations (single injection). The nine-month serum antibody titers indicate that a single injection of a mixture of aluminum and PLGA-formulated HBsAg results in equal or better immune responses than two injections of aluminum-formulated HBsAg vaccine. Based on these invitro and in vivo studies, it is concluded that HBsAg can be successfully encapsulated and recovered from the PLGA microspheres and a mixture of aluminum-adjuvanted and PLGA-formulated HBsAg can auto-boost an immune response in manner comparable to multiple injections of an aluminum-formulated vaccine. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:1019,1035, 2002 [source] Aspirin and salicylate inhibit colon cancer medium- and VEGF-induced endothelial tube formation: correlation with suppression of cyclooxygenase-2 expressionJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2003M. I. Shtivelband Summary., To determine whether aspirin and salicylate suppress colon cancer cell-mediated angiogenesis, we evaluated the effects of aspirin and sodium salicylate on endothelial tube formation on Matrigel. Aspirin and sodium salicylate concentration-dependently inhibited human endothelial cell (EC) tube formation induced by conditioned medium collected from DLD-1, HT-29 or HCT-116 colon cancer cells. Aspirin and sodium salicylate at pharmacological concentrations were equally effective in blocking tube formation. Neutralizing antivascular endothelial growth factor (VEGF) antibodies blocked colon cancer medium-induced tube formation. VEGF receptor 2 but not receptor 1 antibodies inhibited tube formation to a similar extent as anti-VEGF antibodies. These results indicate that VEGF interaction with VEGF receptor 2 is the primary mechanism underlying colon cancer-induced angiogenesis. Aspirin or sodium salicylate inhibited VEGF-induced tube formation in a concentration-dependent manner comparable to that of inhibition of colon cancer medium-induced endothelial tube formation. It has been shown that cyclooxygenase-2 (COX-2) is pivotal in cancer angiogenesis. We found that colon cancer medium-induced COX-2 protein expression in EC and aspirin or sodium salicylate suppressed the cancer-induced COX-2 protein levels at concentrations correlated with those that suppressed endothelial tube formation. Furthermore, aspirin and sodium salicylate inhibited COX-2 expression stimulated by VEGF. These findings indicate that aspirin and other salicylate drugs at pharmacological concentrations inhibit colon cancer-induced angiogenesis which is correlated with COX-2 suppression. [source] | |||||||||||||