Search results for "bacteri"
showing 10 items of 5466 documents
The evolution and changing ecology of the African hominid oral microbiome
2021
Significance The microbiome plays key roles in human health, but little is known about its evolution. We investigate the evolutionary history of the African hominid oral microbiome by analyzing dental biofilms of humans and Neanderthals spanning the past 100,000 years and comparing them with those of chimpanzees, gorillas, and howler monkeys. We identify 10 core bacterial genera that have been maintained within the human lineage and play key biofilm structural roles. However, many remain understudied and unnamed. We find major taxonomic and functional differences between the oral microbiomes of Homo and chimpanzees but a high degree of similarity between Neanderthals and modern humans, incl…
Randomized Comparative Trial with Ceftizoxime and Cefotaxime in Urinary Tract Infections
1984
Ceftizoxime, a new, semisynthetic, beta-lactamase-resistant cephalosporin, is not metabolized in man and is excreted almost entirely as the original active compound in the urine. The efficacy and safety of ceftizoxime were assessed in 80 patients with acute and chronic urinary infections, with and without associated pathological conditions, in comparison with cefotaxime. Two dosage schedules, 1 g or 0.5 g every 12 h, i.v. or i.m. for 10 days, were adopted according to the severity of each case and to separate randomization tables for each schedule; causal agents were all sensitive to both drugs in vitro. The overall results were excellent. Safety was excellent in almost all cases. In this t…
NG2-expressing cells in the nervous system revealed by the NG2-EYFP-knockin mouse.
2008
The NG2 glycoprotein is a type I membrane protein expressed by immature cells in the developing and adult mouse. NG2+ cells of the embryonic and adult brain have been principally viewed as oligodendrocyte precursor cells but have additionally been considered a fourth glial class. They are likely to be a heterogeneous population. In order to facilitate studies on the function of NG2+ cells and to characterize these cells in situ, we generated an enhanced yellow fluorescent protein (EYFP) “knockin mouse.” EYFP-expressing cells in heterozygous knockin mice expressed the NG2 protein in all regions and at all ages studied. The EYFP+ cells did not express markers of mature glia, developing or mat…
Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils
2006
Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In …
Bacteriochlorin-diketopyrrolopyrrole (DPP) hybrids : New near-infrared fluorophores for biosensing/bioimaging applications
2020
Near-infrared (700-900 nm) absorbing and emitting organic-based fluorophores are valuable tools for bioimaging applications. Indeed, biological component absorption, diffusion and autofluorescence are quite low in this region (known as the first therapeutic window NIR-I), making tissues relatively transparent to these long wavelengths. Bacteriochlorins are porphyrins derivatives in which two double bonds are reduced. These molecules display a strong absorption and emission within NIR-I spectral range. DPPs are structurally simpler fluorophores displaying very interesting properties. They have high fluorescence quantum yields, are highly (photo)chemically and thermally stable. The aim of thi…
Molecular analysis of the nitrate-reducing community from unplanted and maize-planted soils
2002
ABSTRACT Microorganisms that use nitrate as an alternative terminal electron acceptor play an important role in the global nitrogen cycle. The diversity of the nitrate-reducing community in soil and the influence of the maize roots on the structure of this community were studied. The narG gene encoding the membrane bound nitrate reductase was selected as a functional marker for the nitrate-reducing community. The use of narG is of special interest because the phylogeny of the narG gene closely reflects the 16S ribosomal DNA phylogeny. Therefore, targeting the narG gene provided for the first time a unique insight into the taxonomic composition of the nitrate-reducing community in planted an…
Genetic and Environmental Controls on Nitrous Oxide Accumulation in Lakes
2015
We studied potential links between environmental factors, nitrous oxide (N2O) accumulation, and genetic indicators of nitrite and N2O reducing bacteria in 12 boreal lakes. Denitrifying bacteria were investigated by quantifying genes encoding nitrite and N2O reductases (nirS/nirK and nosZ, respectively, including the two phylogenetically distinct clades nosZ(I) and nosZ(II)) in lake sediments. Summertime N2O accumulation and hypolimnetic nitrate concentrations were positively correlated both at the inter-lake scale and within a depth transect of an individual lake (Lake Vanajavesi). The variability in the individual nirS, nirK, nosZ(I), and nosZ(II) gene abundances was high (up to tenfold) a…
Concise asymmetric synthesis of Linezolid through catalyzed Henry reaction
2013
A new asymmetric synthesis of the antibiotic Linezolid was performed through a copper-catalyzed Henry reaction as the key step. The use of camphor-derived aminopyridine ligands helped to improve the yields of the chiral precursor and to obtain Linezolid in good overall yield and enantiomeric excess.
Mapping field-scale spatial patterns of size and activity of the denitrifier community
2009
International audience; There is ample evidence that microbial processes can exhibit large variations in activity on a field scale. However, very little is known about the spatial distribution of the microbial communities mediating these processes. Here we used geostatistical modelling to explore spatial patterns of size and activity of the denitrifying community, a functional guild involved in N-cycling, in a grassland field subjected to different cattle grazing regimes. We observed a non-random distribution pattern of the size of the denitrifier community estimated by quantification of the denitrification genes copy numbers with a macro-scale spatial dependence (6–16 m) and mapped the dis…
Zum Problem der Stickstoffbilanz beim Keimwachstum in Stabilisatoren
1960
Es wurde das Keimwachstum in Verbindung mit Stickstoffbilanzen in experimentell infizierten Blutkonserve-Stabilisatoren untersucht. Hierbei zeigte sich, das bei einzelnen Stammen gramnegativer Stabchen eine deutliche Keimvermehrung in diesen Medien stattfindet, obwohl sie in ihrer chemischen Zusammensetzung keine Stickstoffquelle enthalten. Da es im Verlauf der Keimvermehrung zu einer progressiven N-Zunahme kam (Initialwert der beimpften Stabilisatormenge 4–6 γ, Endwert zwischen 10 und 20 γ/ml), vermuten wir, das eine Fixierung atmospharischen Stickstoffs durch die genannten Keime stattgefunden hat. Kontrollteste mit anderen gramnegativen sowie mit grampositiven Bakterien verliefen negativ.