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Parallel Experiments (parallel + experiment)
Selected AbstractsPreparation and characterization of a molecularly imprinted monolithic column for pressure-assisted CEC separation of nitroimidazole drugsELECTROPHORESIS, Issue 16 2010Sulan Liao Abstract A polymethacrylate-based molecularly imprinted monolithic column bearing mixed functional monomers, using non-covalent imprinting approach, was designed for the rapid separation of nitroimidazole compounds. The new monolithic column has been prepared via simple in situ polymerization of 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate and ethylene dimethacrylate, using (S)-ornidazole ((S)-ONZ) as template in a binary porogenic mixture consisting of toluene and dodecanol. The composition of the polymerization mixture was systematically altered and optimized by altering the amount of monomers as well as the composition of the porogenic solvent. The column performance was evaluated in pressure-assisted CEC mode. Separation conditions such as pH, voltage, amount of organic modifier and salt concentration were studied. The optimized monolithic column resulted in excellent separation of a group of structurally related nitroimidazole drugs within 10,min in isocratic elution condition. Column efficiencies of 99,000, 80,000, 103,000, 60,000 and 99,000,plates/m were obtained for metronidazole, secnidazole, ronidazole, tinidazole and dimetridazole, respectively. Parallel experiments were carried out using molecularly imprinted and non-imprinted capillary columns. The separation might be the result of combined effects including hydrophobic, hydrogen bonding and the imprinting cavities on the (S)-ONZ-imprinted monolithic column. [source] Determining the Vapor Pressures of Diacetone Diperoxide (DADP) and Hexamethylene Triperoxide Diamine (HMTD)PROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 6 2009Jimmie Abstract The vapor signature of diacetone diperoxide (DADP) and hexamethylene triperoxide diamine (HMTD) were examined by a gas chromatography (GC) headspace technique over the range of 15 to 55,°C. Parallel experiments were conducted to redetermine the vapor pressures of 2,4,6-trinitrotoluene (TNT) and triacetone triperoxide (TATP). The TNT and TATP vapor pressures were in agreement with the previously reported results. Vapor pressure of DADP was determined to be 17.7,Pa at 25,°C, which is approximately 2.6 times higher than TATP at the same temperature. The Clapeyron equation, relating vapor pressure and temperature, was LnP (Pa)=35.9,9845.1/T (K) for DADP. Heat of sublimation, calculated from the slope of the line for the Clapeyron equation, was 81.9,kJ mole,1. HMTD vapor pressure was not determined due to reduced thermal stability resulting in vapor phase decomposition products. [source] Screening of Protein-Ligand Interactions by Affinity ChromatographyBIOTECHNOLOGY PROGRESS, Issue 2 2003Carlos D. García This paper examines affinity chromatography (AC) as an alternative tool for the determination of protein-ligand interactions for the particular case in which the ligand is the same protein. The methodology is less labor-intensive and more sample-efficient than traditional methods used to measure the second virial coefficient ( B22), a parameter commonly used to evaluate protein-protein interactions. The chromatographic capacity factor ( k,) was studied for lysozyme and equine serum albumin for a wide range of experimental solution conditions such as crystallizing agent concentration, protein concentration and pH. Parallel experiments using AC to determine k, and static light scattering (SLS) to determine B22 showed that the two parameters were highly correlated. Two different column volumes (,1 and ,0.1 mL) were tested and gave essentially the same values for k,, showing the feasibility of miniaturization. [source] Transfer of Cd, Cu, Ni, Pb, and Zn in a soil-plant-invertebrate food chain: A microcosm study,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2006Renaud Scheifler Abstract The transfer of Cd, Cu, Ni, Pb, and Zn was evaluated in a soil-plant (lettuce, Lactuca sativa),invertebrate (snail, Helix aspersa) food chain during a microcosm experiment. Two agricultural soils, polluted and unpolluted, were studied. Lettuce was cultivated for eight weeks before introduction of snails into the microcosms (M-snails). In a parallel experiment, snails were exposed to lettuce only (i.e., without soil) in simpler exposure devices called containers (C-snails). Snail exposure duration was eight weeks for both M- and C-snails. No effects on snail survival were found. Both M- and C-snails exposed to polluted soil showed a growth reduction, but only after two weeks of exposure. Time-dependent accumulation in M-snails exposed to the polluted environment showed a regular increase of Cd and Zn concentrations over time and a rapid increase of Pb concentrations within the first two weeks, which then remained stable. Copper and Ni concentrations did not increase during any of the experiments. Concentrations in M- and C-snails were compared to estimate the relative contribution of soil and plant to the total bioaccumulation. The results suggest that the soil contribution may be higher than 80% for Pb, from 30 to 60% for Zn, and from 2 to 40% for Cd. [source] Evaluation of effects of rofecoxib on platelet function in an in vitro model of thrombosis with circulating human bloodEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 4 2004M. R. Hernandez Abstract Background, Cyclooxygenase (COX)-2-selective non-steroidal anti-inflammatory drugs have been used for anti-inflammatory therapy. However, it has also been described that they may increase risk of cardiovascular events. Objectives, To study the effects of COX2 inhibitor rofecoxib on platelet function using in vitro tests. Results were compared with those obtained in a parallel experiment with acetyl salicylic acid (ASA). Methods, Studies of platelet aggregation, using different agonists, were performed by a turbidimetric method. Adhesive and cohesive function of platelets were analyzed by perfusion techniques, treated blood was exposed to thrombogenic surfaces and platelet interaction was morphometrically evaluated. Results, Twenty-five µM of rofecoxib induced a prolonged lag time and a reduction in the percentage of aggregation when arachidonic acid, ADP or collagen were used as agonists. In perfusion studies with parallel chamber rofecoxib 50 µM and ASA 500 µM reduced overall platelet interaction with the collagen surface (17·4 ± 3·7, P < 0·05; vs. 32·1 ± 2·6%P < 0·05 and 17·9 ± 2·4, vs. 31·9 ± 3·24, P < 0·05, respectively). In studies performed on annular chambers, 25 µM of rofecoxib reduced platelet interaction; values of the thrombus and covered surface were 17·4 ± 4·5%; P < 0·05 and 21·1 ± 4·1%; P < 0·05, respectively, vs. 30·4 ± 7·5% and 33·5 ± 6·5 in the control. ASA did also impair thrombus formation but differences did not reach the levels of statistical significance. Moreover, rofecoxib but not ASA reduced significantly thrombus height and thrombus area (7·4 ± 0·5 µM; P < 0·005 and 96·0 ± 21·2 µM2; P < 0·05 vs. control 11·2 ± 0·9 µM and 220·0 ± 47·7µM2, respectively). Conclusion, We conclude that under our experimental conditions, rofecoxib diminished platelet aggregation induced by different agonists and inhibited platelet-mediated thrombogenesis in an in vitro model of thrombosis. [source] Cortico-cortical connectivity of the human mid-dorsolateral frontal cortex and its modulation by repetitive transcranial magnetic stimulationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2001Abstract Modulation of cortico-cortical connectivity in specific neural circuits might underlie some of the behavioural effects observed following repetitive transcranial magnetic stimulation (rTMS) of the human frontal cortex. This possibility was tested by applying rTMS to the left mid-dorsolateral frontal cortex (MDL-FC) and subsequently measuring functional connectivity of this region with positron emission tomography (PET) and TMS. The results showed a strong rTMS-related modulation of brain activity in the fronto-cingulate circuit. These results were confirmed in a parallel experiment in the rat using electrical stimulation and field-potential recordings. Future studies are needed to provide a direct link between the rTMS-induced modulation of cortical connectivity and its effects on specific behaviours. [source] Combined effects of elevated temperatures and reduced leaf litter quality on the life-history parameters of a saprophagous macroarthropodGLOBAL CHANGE BIOLOGY, Issue 1 2009JEAN-FRANCOIS DAVID Abstract Because soil macroinvertebrates strongly modify decomposition processes, it is important to know how their abundance will respond to global change. We investigated in laboratory microcosms, the effects of elevated temperatures and reduced leaf litter quality on the life-history traits of a saprophagous macroarthropod (development time, growth, survival and reproduction). Millipedes (Polydesmus angustus) from an Atlantic temperate forest were reared throughout their life cycle (,16 months) under two temperature regimes differing on average by 3.3 °C; in a factorial design, they were fed either on Atlantic leaf litter or on Mediterranean leaf litter with a higher C : N ratio; humidity was consistently high. The components of the population growth rate (r) were affected positively by the temperature rise and negatively by the switch from Atlantic to Mediterranean leaf litter. When both treatments were combined, litter effects offset temperature effects. These results show that the short-term response of saprophagous macroarthropods to warming is positive but depends on the availability of high-quality litter, which is difficult to predict in the global change context. In a parallel experiment, conspecific millipedes from a Mediterranean population, which have evolved for a long time in a warmer climate and on poor-quality litter, were reared at elevated temperatures on Mediterranean leaf litter. All components of r were higher than in the Atlantic population under the same conditions. This suggests that in the longer term, macroarthropods can overcome detrimental trophic interactions. Based on our study and the literature, we conclude that for decades the positive effects of warming on saprophagous macrofauna should exceed the negative effects of changes in litter quality. The abundance of those organisms in temperate forests could increase, which is confirmed by latitudinal patterns in Europe. Studies aimed at predicting the impacts of global change on decomposition will need to consider interactions with soil macroinvertebrates. [source] Fusion core structure of the severe acute respiratory syndrome coronavirus (SARS-CoV): In search of potent SARS-CoV entry inhibitorsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008Ling-Hon Matthew Chu Abstract Severe acute respiratory coronavirus (SARS-CoV) spike (S) glycoprotein fusion core consists of a six-helix bundle with the three C-terminal heptad repeat (HR2) helices packed against a central coiled-coil of the other three N-terminal heptad repeat (HR1) helices. Each of the three peripheral HR2 helices shows prominent contacts with the hydrophobic surface of the central HR1 coiled-coil. The concerted protein,protein interactions among the HR helices are responsible for the fusion event that leads to the release of the SARS-CoV nucleocapsid into the target host-cell. In this investigation, we applied recombinant protein and synthetic peptide-based biophysical assays to characterize the biological activities of the HR helices. In a parallel experiment, we employed a HIV-luc/SARS pseudotyped virus entry inhibition assay to screen for potent inhibitory activities on HR peptides derived from the SARS-CoV S protein HR regions and a series of other small-molecule drugs. Three HR peptides and five small-molecule drugs were identified as potential inhibitors. ADS-J1, which has been used to interfere with the fusogenesis of HIV-1 onto CD4+ cells, demonstrated the highest HIV-luc/SARS pseudotyped virus-entry inhibition activity among the other small-molecule drugs. Molecular modeling analysis suggested that ADS-J1 may bind to the deep pocket of the hydrophobic groove on the surface of the central coiled-coil of SARS-CoV S HR protein and prevent the entrance of the SARS-CoV into the host cells. J. Cell. Biochem. 104: 2335,2347, 2008. © 2008 Wiley-Liss, Inc. [source] Stimulation of the rat somatosensory cortex at different frequencies and pulse widthsNMR IN BIOMEDICINE, Issue 1 2006N. Van Camp Abstract Functional MRI (fMRI) during electrical somatosensory stimulation of the rat forepaw is a widely used model to investigate the functional organization of the somatosensory cortex or to study the underlying mechanisms of the blood oxygen level-dependent (BOLD) response. In reality, somatosensory stimuli have complex timing relationships and are of long duration. However, by default electrical sensory stimulation seems to be performed at an extremely short pulse width (0.3,ms). As the pulse duration may alter the neuronal response, our aim was to investigate the influence of a much longer stimulus pulse width (10,ms) using BOLD fMRI during electrical forepaw stimulation. The optimal neuronal response was investigated by varying the stimulus frequency at a fixed pulse duration (10,ms) and amplitude (1,mA). In a parallel experiment we measured the neuronal response directly by recording the somatosensory evoked potentials (SEPs). Quantification of the BOLD data revealed a shift in the optimal response frequencies to 8,10,Hz compared with 1,Hz at 0.3,ms. The amplitude of the recorded SEPs decreased with increasing stimulation frequency and did not display any correlation with the BOLD data. Nevertheless, the summated SEPs, which are a measure of the integrated neuronal activity as a function of time, displayed a similar response profile, with a similar maximum as observed by relative BOLD changes. This shift in optimal excitation frequencies might be related to the fact that an increased pulse width of an electrical stimulus alters the nature of the stimulation, generating also sensorimotor instead of merely somatosensory input. This may influence or alter the activated pathways, resulting in a shift in the optimal response profile. Copyright © 2006 John Wiley & Sons, Ltd. [source] Unexpected Photolysis of the Sunscreen Octinoxate in the Presence of the Sunscreen Avobenzone,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Robert M. Sayre ABSTRACT A major concern raised about photostability studies of sunscreen products is that the photodegradation of sunscreens does not readily translate into changes in product performance. This study examines the correlation between photochemical degradation of sunscreen agents and changes in protection provided by sunscreen films. Films of a commercial sunscreen product containing avobenzone, oxybenzone and octinoxate were irradiated using a fluorescent UV-A phototherapy lamp with additional UV-B blocking filter. Periodically, during irradiation the transmittances of the films were measured and samples collected for chemical analysis of the sunscreen agents using high-performance liquid chromatography techniques. The results show that UV-induced changes in UV transmittance of sunscreen films correlate with changes in concentration of sunscreen agents. In a parallel experiment, we also irradiated a thin film of the same product in the cavity of an electron spin resonance (ESR) spectrometer. We report the concomitant photolysis of avobenzone and octinoxate that predominates over expected E/Z photoisomerization and that irradiation of a film of this product produced free radicals detected by ESR spectroscopy that persisted even after exposure had ended. [source] Amplification of low quantity bacterial RNA for microarray studies: time-course analysis of Leptospirillum ferrooxidans under nitrogen-fixing conditions,ENVIRONMENTAL MICROBIOLOGY, Issue 6 2006Mercedes Moreno-Paz Summary We have developed a method for the amplification of low quantity total bacterial RNA for DNA microarrays analysis. Current methods are based on the linear amplification by the in vitro transcription from the T7 promoter, similar to that used for eukaryotic mRNA amplification. For the incorporation of T7 promoter, the prokaryotic RNA must be enzymatically modified for the incorporation of a polyA tail at the 3, end to emulate the eukaryotic mRNA. The method we describe and validate herein avoids this step by the direct and random incorporation of the T7 promoter. From 500 ng of total bacterial RNA, we obtained 130,150 µg of antisense RNA, such products being good substrate for fluorescent labelling and DNA microarray analysis. The method was validated with bacterial samples from which it is very difficult to obtain sufficient amounts and quality of total RNA for global gene expression analysis. This is critical for low cell density growing microorganisms, environmental samples, or many extremophiles where the composition of the cultural media severely affects the RNA yield, like in the case of the acidophile and iron oxidizer Gram-negative bacterium Leptospirillum ferrooxidans. We further validated our amplification method in parallel experiments with non-amplified RNA by following the expression of the L. ferrooxidans nif regulon along the time-course of growth. [source] SELECTION AGAINST LATE EMERGENCE AND SMALL OFFSPRING IN ATLANTIC SALMON (SALMO SALAR)EVOLUTION, Issue 2 2000Sigurd Einum Abstract., Timing of breeding and offspring size are maternal traits that may influence offspring competitive ability, dispersal, foraging, and vulnerability to predation and climatic conditions. To quantify the extent to which these maternal traits may ultimately affect an organism's fitness, we undertook laboratory and field experiments with Atlantic salmon (Salmo salar). To control for confounding effects caused by correlated traits, manipulations of the timing of fertilization combined with intraclutch comparisons were used. In the wild, a total of 1462 juveniles were marked at emergence from gravel nests. Recapture rates suggest that up to 83.5% mortality occurred during the first four months after emergence from the gravel nests, with the majority (67.5%) occurring during the initial period ending 17 days after median emergence. Moreover, the mortality was selective during this initial period, resulting in a significant phenotypic shift toward an earlier date of and an increased length at emergence. However, no significant selection differentials were detected thereafter, indicating that the critical episode of selection had occurred at emergence. Furthermore, standardized selection gradients indicated that selection was more intense on date of than on body size at emergence. Timing of emergence had additional consequences in terms of juvenile body size. Late-emerging juveniles were smaller than early-emerging ones at subsequent samplings, both in the wild and in parallel experiments conducted in seminatural stream channels, and this may affect success at subsequent size-selective episodes, such as winter mortality and reproduction. Finally, our findings also suggest that egg size had fitness consequences independent of the effects of emergence time that directly affected body size at emergence and, in turn, survival and size at later life stages. The causality of the maternal effects observed in the present study supports the hypothesis that selection on juvenile traits may play an important role in the evolution of maternal traits in natural populations. [source] Methods for the identi,cation of chemical respiratory allergens in rodents: comparisons of cytokine pro,ling with induced changes in serum IgEJOURNAL OF APPLIED TOXICOLOGY, Issue 4 2003R. J. Dearman Abstract No validated or widely recognized test methods are currently available for the prospective identi,cation of chemicals with the potential to cause respiratory allergy. The cellular and molecular mechanisms that result in the induction of chemical sensitization of the respiratory tract are unclear, although there is evidence for the selective development of T helper 2 (Th2)-type responses and, in some cases, the production of IgE antibody. We have therefore examined the utility of cytokine pro,ling using BALB/c mice, together with the measurement of induced increases in the total serum concentration of IgE in the Brown Norway (BN) rat, as markers for the prospective identi,cation of chemical respiratory allergens. Responses provoked by the reference respiratory allergen trimellitic anhydride (TMA) have been compared with those stimulated by the respiratory sensitizing diisocyanates toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI) and by the acid anhydride hexahydrophthalic anhydride (HHPA). Topical exposure of BN rats to TMA, TDI and HHPA each provoked marked immune activation (increases in lymph node cellularity and proliferation). However, only treatment with TMA stimulated vigorous increases in the total serum concentration of IgE. In contrast, exposure to HHPA, TDI or HDI failed to provoke signi,cant changes in serum IgE concentration or induced only transient and relatively weak increases in serum IgE levels. In parallel experiments using BALB/c strain mice, however, topical application of all four chemical respiratory allergens provoked a marked Th2-type cytokine secretion pro,le in draining lymph node cells. These data suggest that the measurement of induced changes in serum IgE is not suf,ciently sensitive for the robust identi,cation of chemical respiratory allergens. Furthermore, irrespective of the reasons for variations in TMA-induced IgE production among BN rats, doubts remain regarding the utility of these animals for the characterization of immune responses to chemical allergens. Cytokine pro,ling using the BALB/c strain mouse apparently provides a more robust method for the hazard assessment of chemical respiratory allergens. Copyright © 2003 John Wiley & Sons, Ltd. [source] Molecular response of nasal mucosa to therapeutic exposure to broad-band ultraviolet radiationJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1-2 2010David Mitchell Abstract Ultraviolet radiation (UVR) phototherapy is a promising new treatment for inflammatory airway diseases. However, the potential carcinogenic risks associated with this treatment are not well understood. UV-specific DNA photoproducts were used as biomarkers to address this issue. Radioimmunoassay was used to quantify cyclobutane pyrimidine dimers (CPDs) and (6,4) photoproducts in DNA purified from two milieus: nasal mucosa samples from subjects exposed to intranasal phototherapy and human airway (EpiAirwayÔ) and human skin (EpiDermÔ) tissue models. Immunohistochemistry was used to detect CPD formation and persistence in human nasal biopsies and human tissue models. In subjects exposed to broadband ultraviolet radiation, DNA damage frequencies were determined prior to as well as immediately after treatment and at increasing times post-treatment. We observed significant levels of DNA damage immediately after treatment and efficient removal of the damage within a few days. No residual damage was observed in human subjects exposed to multiple UVB treatments several weeks after the last treatment. To better understand the molecular response of the nasal epithelium to DNA damage, parallel experiments were conducted in EpiAirway and EpiDerm model systems. Repair rates in these two tissues were very similar and comparable to that observed in human skin. The data suggest that the UV-induced DNA damage response of respiratory epithelia is very similar to that of the human epidermis and that nasal mucosa is able to efficiently repair UVB induced DNA damage. [source] Mitogenic effects of phospholipase D and phosphatidic acid in transiently permeabilized astrocytes: effects of ethanolJOURNAL OF NEUROCHEMISTRY, Issue 1 2003Beate Schatter Abstract Investigations of lipid-mediated signalling pathways are often limited by a lack of methods for the intracellular delivery of lipid messengers. We established a procedure for the transient permeabilization of astrocytes by an oxygen-insensitive mutant of streptolysin-O (SLO) to investigate the participation of the phospholipase D (PLD) signalling pathway in astroglial cell proliferation. Exogenous PLD, when incubated in the presence of SLO, caused an increase in DNA synthesis (measured by thymidine incorporation) which was completely suppressed by ethanol (0.3%, v/v). In parallel experiments, phosphatidic acid also induced a dose-dependent mitogenic response which, however, was not affected by the presence of ethanol. Phosphatidic acid was more effective in this assay than diacylglycerol but its effect was sensitive to the protein kinase inhibitor Ro 31-8220. Our findings provide direct evidence that disruption of the PLD signalling pathway by ethanol is sufficient to suppress astroglial proliferation, an effect that might contribute to the inhibition of brain growth in alcoholic embryopathy. [source] Intratracheal clenbuterol in the horse: its pharmacological efficacy and analytical detectionJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2000J. D. HARKINS Clenbuterol, a ,2 agonist/antagonist, is the only bronchodilator approved by the US Food and Drug Administration for use in horses. The Association of Racing Commissioners International classifies clenbuterol as a class 3 agent, and, as such, its identification in post-race samples may lead to sanctions. Anecdotal reports suggest that clenbuterol may have been administered by intratracheal (IT) injection to obtain beneficial effects and avoid post-race detection. The objectives of this study were (1) to measure the pharmacological efficacy of IT dose of clenbuterol and (2) to determine the analytical findings in urine in the presence and absence of furosemide. When administered intratracheally (90,,g/horse) to horses suffering from chronic obstructive pulmonary disease (COPD), clenbuterol had effects that were not significantly different from those of saline. In parallel experiments using a behavior chamber, no significant effects of IT clenbuterol on heart rate or spontaneous locomotor activity were observed. Clenbuterol concentrations in the urine were also measured after IT dose in the presence and absence of furosemide. Four horses were administered i.v. furosemide (5,mg/kg), and four horses were administered saline (5,mL). Two hours later, all horses were administrated clenbuterol (IT, 90,,g), and the furosemide-treated horses received a second dose of furosemide (2.5 mg/kg, i.v.). Three hours after clenbuterol dose (1,h after hypothetical ,post-time'), the mean specific gravity of urine samples from furosemide-treated horses was 1.024, well above the 1.010 concentration at which furosemide is considered to interfere with drug detection. There was no interference by furosemide with ,enhanced' ELISA screening of clenbuterol equivalents in extracted and concentrated samples. Similarly, furosemide had no effect on mass spectral identification or quantification of clenbuterol in these samples. These results suggest that the IT dose of clenbuterol (90,,g) is, in pharmacological terms, indistinguishable from the dose of saline, and that, using extracted samples, clenbuterol dose is readily detectable at 3,h after dosing. Furthermore, concomitant dose of furosemide does not interfere with detection or confirmation of clenbuterol. [source] Laboratory studies to assess the risk of development of resistance to zoxamidePEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2001David H Young Abstract Laboratory studies were conducted to evaluate the risk of developing field resistance to zoxamide, a new Oomycete fungicide which acts on microtubules. Zoxamide, metalaxyl and dimethomorph were compared with respect to the ease with which fungicide-resistant mutants could be isolated and their level of resistance. Attempts to generate mutants of Phytophthora capsici and P infestans with resistance to zoxamide by mycelial adaptation on fungicide-amended medium were unsuccessful. Similarly, changes in sensitivity to zoxamide were small (resistance factors ,2.2) in mutants of P capsici isolated by chemical mutagenesis of zoospore cysts. In parallel experiments with metalaxyl, highly resistant mutants were obtained using both adaptation (P capsici or P infestans) and chemical mutagenesis (P capsici). For dimethomorph, chemical mutagenesis (P capsici) yielded moderately resistant mutants (maximum resistance factor,=,20.9), and adaptation (P capsici or P infestans) did not induce resistance. It is proposed that failure to isolate mutants resistant to zoxamide results from the diploid nature of Oomycete fungi and the likelihood that target-site mutations would produce a recessive phenotype. Our studies suggest that the risk of a highly resistant pathogen population developing rapidly in the field is much lower for zoxamide than for metalaxyl. However, as with any site-specific fungicide, appropriate precautions against resistance development should be taken. © 2001 Society of Chemical Industry [source] Selective over-expression of fibroblast growth factor receptors 1 and 4 in clinical prostate cancer,THE JOURNAL OF PATHOLOGY, Issue 1 2007K Sahadevan Abstract Fibroblast growth factor receptors (FGFRs) mediate the tumourigenic effects of FGFs in prostate cancer. These receptors are therefore potential therapeutic targets in the development of inhibitors to this pathway. To identify the most relevant targets, we simultaneously investigated FGFR1,4 expression using a prostate cancer tissue microarray (TMA) and in laser capture microdissected (LCM) prostate epithelial cells. In malignant prostates (n = 138) we observed significant FGFR1 and FGFR4 protein over-expression in comparison with benign prostates (n = 58; p < 0.0001). FGFR1 was expressed at high levels in the majority of tumours (69% of grade 3 or less, 74% of grade 4 and 70% of grade 5), while FGFR4 was strongly expressed in 83% of grade 5 cancers but in only 25% of grade 1,3 cancers (p < 0.0001). At the transcript level we observed a similar pattern, with FGFR1 and FGFR4 mRNA over-expressed in malignant epithelial cells compared to benign cells (p < 0.0005 and p < 0.05, respectively). While total FGFR2 was increased in some cancers, there was no association between expression and tumour grade or stage. Transcript analysis, however, revealed a switch in the predominant isoform expressed from FGFR2IIIb to FGFR2IIIc among malignant epithelial cells. In contrast, protein and transcript expression of FGFR3 was very similar between benign and cancer biopsies. The functional effect of targeting FGFR4 in prostate cancer cells has not previously been investigated. In in vitro experiments, suppression of FGFR4 by RNA interference effectively blocked prostate cancer cell proliferation (p < 0.0001) and invasion (p < 0.001) in response to exogenous stimulation. This effect was evident regardless of whether the cells expressed the FGFR4 Arg388 or Gly388 allele. In parallel experiments, FGFR3 suppression had no discernible effect on cancer cell behaviour. These results suggest evidence of selective over-expression of FGFR1 and FGFR4 in clinical prostate cancer and support the notion of targeted inhibition of these receptors to disrupt FGF signalling. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Blood and haemoglobin meal as protein sources in diets for gilthead sea bream (Sparus aurata): effects on growth, nutritive efficiency and fillet sensory differencesAQUACULTURE RESEARCH, Issue 10 2008Silvia Martínez-Llorens Abstract Two parallel experiments were conducted to evaluate the effect of partial substitution of fish meal by two different animal protein sources, blood meal (B) and haemoglobin meal (H) at 0, 50 and 100 g kg,1 of level inclusion in diets for gilthead sea bream, considering a long feeding period for juveniles (Trial 1) and a short feeding period (Trial 2) for on-growing fish. In Trial 1, 33 g juveniles were fed for 242 days and the fish fed with 5% and 10% of haemoglobin dietary inclusion obtained less growth, although feed efficiency, protein efficiency ratio and muscle composition were similar in all diets. In Trial 2, 179 g initial weight fish were fed for 164 days and growth of fish fed H10 showed the lowest growth, although nutrient efficiency and muscle composition were not affected significantly. The results of these experiments demonstrated that blood meal can substitute fish meal (up to 10%) with no effect on performance, but may lead to sensory differences compared with fish fed diet 0, while the inclusion of 5% blood meal had no effect on growth or sensory characteristics. Fish fed 10% haemoglobin inclusion had the poorest growth values. [source] | ||||||||||||||||