Biological Assessment (biological + assessment)

Distribution by Scientific Domains


Selected Abstracts


Total Synthesis and Biological Assessment of Benzimidazole-Based Analogues of Epothilone A: Ambivalent Effects on Cancer Cell Growth Inhibition

CHEMBIOCHEM, Issue 1 2006
Fréderic Cachoux Dr.
Benzimidazole-based analogues of cis - and trans -Epo A, 2 and 3, have been prepared through stereoselective total synthesis. Both compounds are highly potent antiproliferative agents, but the effects of side-chain replacement on cellular activity are ambivalent. While significantly enhanced potency is observed against a drug-sensitive human cancer cell line, 2 and 3 more susceptible to P-gp-mediated drug efflux than Epo A or trans -Epo A. [source]


Chemical, biological and sensory evaluation of pasta products supplemented with ,-galactoside-free lupin flours

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2007
Alexia Torres
Abstract ,-Galactoside-free lupin flour has been used to supplement durum wheat semolina flour in order to increase the nutritive value of pasta products. Supplemented pasta products had a shorter cooking time, higher cooking water absorption, cooking loss and protein loss in water than control pasta prepared with only semolina. Sensory evaluation of cooked pastas showed that products supplemented with 80 g kg,1 of ,-galactoside-free Lupinus angustifolius var. Emir flour or with 100 g kg,1 of ,-galactoside-free Lupinus angustifolius var. Troll flour showed the same acceptability by panellists as the semolina pasta. These levels of supplementation were selected for further studies. The cooked ,-galactoside-free lupin/semolina pastas showed higher amounts of protein, dietary fibre, calcium, phosphorus, magnesium, zinc and antioxidant capacity than control pasta and a reasonable level of vitamin B1, vitamin B2 and vitamin E. Biological assessment of cooked pastas indicated that the true protein digestibility did not change after the fortification of semolina but protein efficiency ratio increased sharply in the pasta supplemented with ,-galactoside-free lupin flours (2.07 and 1.92 for Emir and Troll lupin varieties, respectively) in comparison with the control pasta (1.11). It is concluded that the ,-galactoside-free lupin flours are an adequate ingredient to improve the nutritional quality of pasta products without adding flatulent oligosaccharides. Copyright © 2006 Society of Chemical Industry [source]


A new index of habitat alteration and a comparison of approaches to predict stream habitat conditions

FRESHWATER BIOLOGY, Issue 10 2007
BRIAN FRAPPIER
Summary 1. Stream habitat quality assessment complements biological assessment by providing a mechanism for ruling out habitat degradation as a potential stressor and provides reference targets for the physical aspects of stream restoration projects. This study analysed five approaches for predicting habitat conditions based on discriminant function, linear regressions, ordination and nearest neighbour analyses. 2. Quantitative physical and chemical habitat and riparian conditions in minimally-impacted streams in New Hampshire were estimated using United States Environmental Protection Agency's Environmental Monitoring and Assessment Program protocols. Catchment-scale descriptors were used to predict segment-scale stream channel and riparian habitat, and the accuracy and precision of the different modelling approaches were compared. 3. A new assessment index comparing and summarizing the degree of correspondence between predicted and observed habitat based on Euclidean distance between the standardized habitat factors is described. Higher index scores (i.e. greater Euclidean distance) would suggest a greater deviation in habitat between observed conditions and expected reference conditions. As in most biotic indices, the range in index scores in reference sites would constitute a situation equivalent to reference conditions. This new index avoids the erroneous prediction of multiple, mutually exclusive habitat conditions that have confounded previous habitat assessment approaches. 4. Separate linear regression models for each habitat descriptor yielded the most accurate and precise prediction of reference conditions, with a coefficient of variation (CV) between predictions and observations for all reference sites of 0.269. However, for a unified implementation in regions where a classification-based approach has already been taken for biological assessment, a discriminant analysis approach, that predicted membership in biotic communities and compared the mean habitat features in the biotic communities with the observed habitat features, was similar in prediction accuracy and precision (CV = 0.293). 5. The best model had an error of 27% of the mean index value for the reference sites, indicating substantial room for improvement. Additional catchment characteristics not readily available for this analysis, such as average rainfall or winter snow-pack, surficial geological characteristics or past land-use history, may improve the precision of the predicted habitat features in the reference streams. Land-use history in New Hampshire and regional environmental impacts have greatly impacted stream habitat conditions even in streams considered minimally-impacted today; thus as regional environmental impacts change and riparian forests mature, reference habitat conditions should be re-evaluated. [source]


A pyrazolylamine-phosphonate monoester chelator for the fac -[M(CO)3]+ core (M = Re, 99mTc): synthesis, coordination properties and biological assessment

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 13 2007
Elisa Palma
Abstract Aiming to develop new strategies for the labeling of hydroxyl-containing biomolecules with the organometallic core fac -[99mTc(CO)3]+, we have prepared a new model bifunctional chelator, L4 (ethyl hydrogen (2-{[2-(3,5-dimethyl-1H -pyrazol-1-yl)ethyl]amino}ethyl)phosphonate), combining a pyrazolyl-amine chelating group and a monophosphonate ethyl ester function (,P(O)OHOEt). The phosphonate group allows metal stabilization, and, simultaneously, can be considered as a potential attachment site for a biomolecule. Reaction of L4 with the precursor [99mTc(H2O)3(CO)3]+ gave the model radiocomplex [99mTc(CO)3(k3 -L4)] (6a). This radiocomplex was identified by comparing its chromatographic profile with that of the corresponding Re analog (6) under the same conditions, also prepared and fully characterized by the usual analytical techniques. Radiocomplex 6a is moderately lipophilic (log Po/w = 1.07), presenting high stability in vitro without any measurable decomposition or ligand exchange, even in the presence of strong competing chelators such as histidine and cysteine (37°C, 24 h). Biodistribution studies of the complex in CD-1 mice indicated a rapid blood clearance, and a rapid clearance from main organs, occurring primarily through the hepatobiliary pathway. Complex 6a presents also a high robustness in vivo, demonstrated by its resistance to metabolic degradation in blood, and intact excretion into the urine, after RP-HPLC analysis of blood and urine samples. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Anaphylactic reaction to patent blue V after sentinel lymph node biopsy

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2006
P. Dewachter
Background:, We report a documented grade III IgE-mediated hypersensitivity reaction associated with the use of 2.5% patent blue V dye for sentinel lymph node biopsy during breast cancer surgery. Methods:, Immediately after the reaction, when hemodynamic stability was obtained, plasma histamine was measured whereas serum tryptase was not. Six weeks later, with the patient's consent, cutaneous tests to patent blue V dye, methylene blue dye, latex and all drugs used during surgery were performed according to standardized procedures. Results and conclusion:, Clinical symptoms, biological assessment results and cutaneous tests positivity confirmed the onset of an anaphylactic reaction due to patent blue V. Of interest, the positivity of the cutaneous tests observed with patent blue V was not found with methylene blue which might be proposed for further investigations in our patient. This case report confirms the need for systematic allergological investigation of all drugs and substances administered during the peri-operative period in case of an immediate hypersensitivity reaction occurring during anesthesia. [source]


Is the human population a large-scale indicator of the species richness of ground beetles?

ANIMAL CONSERVATION, Issue 5 2010
A. M. Barbosa
Abstract Empirical evidence has often shown a large-scale positive co-occurrence of biodiversity-rich and densely populated regions. This biogeographical pattern has important implications for conservation biology. Previous studies have supported two of the potential mechanisms behind this pattern: the distributions of biodiversity and of human beings tend to match climatic patterns, and human beings have settled in regions of higher habitat heterogeneity or they may have increased it. There has been little testing and evidence for an artefactual explanation: more populated regions may show more species only because of a more thorough sampling. Using a new country-wide dataset, we tested whether the human population density correlates with the species richness of ground beetles in Italy's regions, provinces and 10 × 10 km (UTM) grid cells. As expected, the observed and estimated (Chao index) number of species increases significantly with increasing human population density for regions, while there is no significant variation for provinces. But this is not the case when controlling for sampling effort. Variations in observed and estimated species richness are primarily associated with the available number of records, which is in turn well correlated with human population size. These results were confirmed for endemic and widespread species richness. At the UTM level, when controlling for sampling effort and area, there was a significant positive correlation between the total/widespread species richness and variation in the human population size, while the correlation was negative for endemic species. We found no significant role of habitat heterogeneity in the above relationships. The available distributional data of Carabidae in Italy suggest (1) that the species richness of bio-indicators may not be a reliable measure for regional biological assessment; (2) that some broad-scale human population,biodiversity correlations can be artefactual. [source]