29 research outputs found
Use of a Granulocyte Immunofluorescence Assay Designed for Humans for Detection of Antineutrophil Cytoplasmic Antibodies in Dogs with Chronic Enteropathies
Perinuclear antineutrophil cytoplasmic antibodies (pANCA) previously have been shown to be serum markers in dogs with chronic enteropathies, with dogs that have foodâresponsive disease (FRD) having higher frequencies of seropositivity than dogs with steroidâresponsive disease (SRD). The indirect immunofluorescence (IIF) assay used in previous publications is timeâconsuming to perform, with low interobserver agreement. Fortyâfour dogs with FRD, 20 dogs with SRD, 20 control dogs, and 38 softâcoated wheaten terrier (SCWT) or SCWTâcross dogs
Single copy shRNA configuration for ubiquitous gene knockdown in mice
RNA interference through the expression of small hairpin RNA (shRNA) molecules has become a very promising tool in reverse mouse genetics as it may allow inexpensive and rapid gene function analysis in vivo. However, the prerequisites for ubiquitous and reproducible shRNA expression are not well defined. Here we show that a single copy shRNA-transgene can mediate body-wide gene silencing in mice when inserted in a defined locus of the genome. The most commonly used promoters for shRNA expression, H1 and U6, showed a comparably broad activity in this configuration. Taken together, the results define a novel approach for efficient interference with expression of defined genes in vivo. Moreover, we provide a rapid strategy for the production of gene knockdown mice combining recombinase mediated cassette exchange and tetraploid blastocyst complementation approaches
Influence of the ITCZ on H2O2 in near surface waters in the equatorial Atlantic Ocean
H2O2 was measured in the upper water column (0â200 m) along a west-east transect through the Equatorial Atlantic as part of the German SOLAS (Surface Ocean Lower Atmosphere) cruise Meteor 55 (M55). Vertical profiles of H2O2 showed characteristic exponential decay consistent with light profiles and rainwater inputs. Integrated (0â100 m) water column H2O2 inventories ranged from 1.1â8.9 mmol mâ2 with the highest values in the Amazon Plume. H2O2 inventories were also higher at the Equatorial Upwelling and after heavy rain showers in the region of the Inter Tropical Convergence Zone (ITCZ). Analysis of rain water samples collected during the cruise gave a volume weighted mean of 10.8 ÎŒmol Lâ1 (range 1.5â22.3 ÎŒmol Lâ1). This work highlights the importance of rainwater as a major source for H2O2 in the surface waters under the ITCZ
Regeneration of Fe(II) during EIFeX and SOFeX
Investigations into Fe(II) cycling during two Southern Ocean mesoscale iron enrichment experiments, SOFeX and EIFeX, clearly show the importance of Fe(II) to iron speciation during these experiments. In both cases the added Fe(II) persisted significantly longer than its expected oxidation time indicating a significant Fe reduction process at work. During EIFeX diel studies showed a strong photochemically induced cycle in Fe(II) production in sunlit surface waters. Our results suggest that the photochemical cycling of iron may also be important in unfertilized waters of the Southern Ocean
Development and bioorthogonal activation of palladium-labile prodrugs of gemcitabine
Bioorthogonal
chemistry has become one of the main driving forces
in current chemical biology, inspiring the search for novel biocompatible
chemospecific reactions for the past decade. Alongside the well-established
labeling strategies that originated the bioorthogonal paradigm, we
have recently proposed the use of heterogeneous palladium chemistry
and bioorthogonal Pd<sup>0</sup>-labile prodrugs to develop spatially
targeted therapies. Herein, we report the generation of biologically
inert precursors of cytotoxic gemcitabine by introducing Pd<sup>0</sup>-cleavable groups in positions that are mechanistically relevant
for gemcitabineâs pharmacological activity. Cell viability
studies in pancreatic cancer cells showed that carbamate functionalization
of the 4-amino group of gemcitabine significantly reduced (>23-fold)
the prodrugsâ cytotoxicity. The <i>N</i>-propargyloxycarbonyl
(<i>N</i>-Poc) promoiety displayed the highest sensitivity
to heterogeneous palladium catalysis under biocompatible conditions,
with a reaction half-life of less than 6 h. Zebrafish studies with
allyl, propargyl, and benzyl carbamate-protected rhodamines confirmed <i>N</i>-Poc as the most suitable masking group for implementing <i>in vivo</i> bioorthogonal organometallic chemistry
Prevalence and factors associated with occupational burnout among HIV/AIDS healthcare workers in China: a cross-sectional study
Dry and wet deposition of nutrients from the tropical Atlantic atmosphere: Links to primary productivity and nitrogen fixation
Atmospheric deposition fluxes of soluble nutrients (N, P, Si, Fe, Co, Zn) to the tropical North Atlantic were determined during cruise M55 of the German SOLAS programme. Nutrient fluxes were highest in the east of the section along 10°N, owing to the proximity of source regions in West Africa and Europe, and lowest in the west, for both dry and wet deposition modes. In common with other recent studies, atmospheric P and Si inputs during M55 were strongly depleted relative to the stoichiometry of phytoplankton Fe, N, P and Si requirements. Atmospheric N inputs were equivalent to 0.1â4.7% of observed primary productivity during the cruise. Atmospheric nutrient supply was also compared to observed nitrogen fixation rates during M55. While atmospheric Fe supply may have been sufficient to support N fixation (depending on the relationship between our simple Fe leaching experiment and aerosol Fe dissolution in seawater), atmospheric P supply was well below the required rate. The stable nitrogen isotope composition of nitrateâN in aerosol and rain was also determined. Results of a simple model indicate that atmospheric deposition and nitrogen fixation introduce similar amounts of isotopically light nitrogen into surface waters of the study region. This implies that nitrogen isotope-based methods would overestimate nitrogen fixation here by a factor of 2, if atmospheric inputs were not taken into account
Pre-Session Assessment of Preferences for Students with Profound Multiple Disabilities
This study evaluated the effectiveness of a brief 2 min pre-session stimulus preference assessment in predicting the levels of responding of four students with profound multiple disabilities during a 5-minute experimental session immediately following the assessment. During the pre-session assessment, students were presented with four stimuli selected from a pool of stimuli identified as either preferred (2 stimuli) or neutral (2 stimuli)from a previous preference assessment. The duration of the student\u27s target behavior (smiling or laughing) was recorded. The stimulus with the longest duration was considered preferred and the stimulus with the shortest duration was considered neutral An alternating treatments design (ATD) was then used to evaluate the prediction of student responding based on the pre-session assessment immediately prior to an experimental session. Either the preferred, neutral, or both stimuli were presented within the context of a social interaction and the duration of the student\u27s target behavior (smiling or laughing) was recorded. Teacher behavior, time of day, position of the child, materials, and activities, were controlled. Results indicate that the 2 min pre-session assessment had predictive value, that is, there were higher levels of student responding during the condition when the preferred stimulus was wed than when the neutral stimulus was used across all four students