104 resultados para sensitive topic
Resumo:
Twenty-four shed-reared lambs were each infected orally with 250 metacercariae of Fasciola hepatica, using either the triclabendazole (TCBZ)-sensitive Cullompton isolate or the TCBZ-resistant Sligo isolate. Twelve weeks after infection the lambs were treated with TCBZ (10 mg/kg) or with the experimental fasciolicide, Compound Alpha (Cpd alpha), a benzimidazole derivative of TCBZ (15 mg/kg). The lambs were euthanised 48,72 and 96 h after TCBZ treatment, or 24, 48 and 72 h after Cpd a treatment, and flukes were collected from the liver and/or gall bladder of each animal. Untreated animals harbouring 12-week infections were euthanised 24 h after administration of anthelmintic to the treatment groups, and the untreated flukes provided control material. A semi-quantitative assessment of the degree of histological change induced by the two drugs after different times of exposure was achieved by scoring the intensity of three well-defined lesions that developed in the testes and uteri of a representative sample of flukes from each lamb. In general, it was found that in those tissues where active meiosis and/or mitosis occurred (testis, ovary, and vitelline follicles), there was progressive loss of cell content due to apparent failure of cell division to keep pace with expulsion of the mature or effete products. Further, actively dividing cell types tended to become individualised, rounded and condensed, characteristic of apoptotic cell death. Protein synthetic activity was apparently inhibited in the Mehlis' secretory cells. In the uterus, where successful formation of shelled eggs represents the culmination of a complex sequence of cytokinetic, cytological and synthetic activity involving the vitelline follicles, the ovary and the Mehlis' gland, histological evidence indicating failure of ovigenesis was evident from 24 h post-treatment onwards. The development of these lesions may be related to the known antitubulin activity of the benzimidazole class of anthelmintics, to the induction of apoptosis in cells where mitosis or meiosis has aborted due to failure of spindle formation, and to drug-induced inhibition of protein synthesis. The semi-quantitative findings indicated that Cpd a is slightly less efficacious than TCBZ itself in causing histological damage to the reproductive structures of TCBZ-sensitive flukes, and that, like TCBZ, it caused no histological damage in flukes of the TCBZ-resistant isolate. This study illustrates the potential utility of histological techniques for conveniently screening representative samples of flukes in field trials designed to validate instances of drug resistance or to test the efficacy of new products against known drug-resistant and drug-susceptible fluke isolates. It also provides reference criteria for drug-induced histopathological changes in fluke reproductive structures which may aid interpretation of TEM findings. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Odontoblasts form the outermost cellular layer of the dental pulp where they have been proposed to act as sensory receptor cells. Despite this suggestion, evidence supporting their direct role in mediating thermo-sensation and nociception is lacking. Transient receptor potential (TRP) ion channels directly mediate nociceptive functions, but their functional expression in human odontoblasts has yet to be elucidated. In the present study, we have examined the molecular and functional expression of thermo-sensitive TRP channels in cultured odontoblast-like cells and in native human odontoblasts obtained from healthy wisdom teeth. PCR and western blotting confirmed gene and protein expression of TRPV1, TRPA1 and TRPM8 channels. Immunohistochemistry revealed that these channels were localised to odontoblast-like cells as determined by double staining with dentin sialoprotein (DSP) antibody. In functional assays, agonists of TRPV1, TRPA1 and TRPM8 channels elicited [Ca2+]i transients that could be blocked by relevant antagonists. Application of hot and cold stimuli to the cells also evoked rises in [Ca2+]i which could be blocked by TRP-channel antagonists. Using a gene silencing approached we further confirmed a role for TRPA1 in mediating noxious cold responses in odontoblasts. We conclude that human odontoblasts express functional TRP channels that may play a crucial role in mediating thermal sensation in teeth. Cultured and native human odontoblasts express functional TRP channels that may play a crucial role in mediating thermal sensation in teeth.
Resumo:
Molecular testing for the BCR-ABL1 fusion gene by real time quantitative polymerase chain reaction (RT-qPCR) is the most sensitive routine approach for monitoring the response to therapy of patients with chronic myeloid leukaemia. In the context of tyrosine kinase inhibitor (TKI) therapy, the technique is most appropriate for patients who have achieved complete cytogenetic remission and can be used to define specific therapeutic milestones. To achieve this effectively, standardization of the laboratory procedures and the interpretation of results are essential. We present here consensus best practice guidelines for RT-qPCR testing, data interpretation and reporting that have been drawn up and agreed by a consortium of 21 testing laboratories in the United Kingdom and Ireland in accordance with the procedures of the UK Clinical Molecular Genetics Society.
Resumo:
Background: Postal and electronic questionnaires are widely used for data collection in epidemiological studies but non-response reduces the effective sample size and can introduce bias. Finding ways to increase response to postal and electronic questionnaires would improve the quality of health research. Objectives: To identify effective strategies to increase response to postal and electronic questionnaires. Search strategy: We searched 14 electronic databases to February 2008 and manually searched the reference lists of relevant trials and reviews, and all issues of two journals. We contacted the authors of all trials or reviews to ask about unpublished trials. Where necessary, we also contacted authors to confirm methods of allocation used and to clarify results presented. We assessed the eligibility of each trial using pre-defined criteria. Selection criteria: Randomised controlled trials of methods to increase response to postal or electronic questionnaires. Data collection and analysis: We extracted data on the trial participants, the intervention, the number randomised to intervention and comparison groups and allocation concealment. For each strategy, we estimated pooled odds ratios (OR) and 95% confidence intervals (CI) in a random-effects model. We assessed evidence for selection bias using Egger's weighted regression method and Begg's rank correlation test and funnel plot. We assessed heterogeneity among trial odds ratios using a Chi 2 test and the degree of inconsistency between trial results was quantified using the I 2 statistic. Main results: Postal We found 481 eligible trials.The trials evaluated 110 different ways of increasing response to postal questionnaires.We found substantial heterogeneity among trial results in half of the strategies. The odds of response were at least doubled using monetary incentives (odds ratio 1.87; 95% CI 1.73 to 2.04; heterogeneity P < 0.00001, I 2 = 84%), recorded delivery (1.76; 95% CI 1.43 to 2.18; P = 0.0001, I 2 = 71%), a teaser on the envelope - e.g. a comment suggesting to participants that they may benefit if they open it (3.08; 95% CI 1.27 to 7.44) and a more interesting questionnaire topic (2.00; 95% CI 1.32 to 3.04; P = 0.06, I 2 = 80%). The odds of response were substantially higher with pre-notification (1.45; 95% CI 1.29 to 1.63; P < 0.00001, I 2 = 89%), follow-up contact (1.35; 95% CI 1.18 to 1.55; P < 0.00001, I 2 = 76%), unconditional incentives (1.61; 1.36 to 1.89; P < 0.00001, I 2 = 88%), shorter questionnaires (1.64; 95%CI 1.43 to 1.87; P < 0.00001, I 2 = 91%), providing a second copy of the questionnaire at follow up (1.46; 95% CI 1.13 to 1.90; P < 0.00001, I 2 = 82%), mentioning an obligation to respond (1.61; 95% CI 1.16 to 2.22; P = 0.98, I 2 = 0%) and university sponsorship (1.32; 95% CI 1.13 to 1.54; P < 0.00001, I 2 = 83%). The odds of response were also increased with non-monetary incentives (1.15; 95% CI 1.08 to 1.22; P < 0.00001, I 2 = 79%), personalised questionnaires (1.14; 95% CI 1.07 to 1.22; P < 0.00001, I 2 = 63%), use of hand-written addresses (1.25; 95% CI 1.08 to 1.45; P = 0.32, I 2 = 14%), use of stamped return envelopes as opposed to franked return envelopes (1.24; 95% CI 1.14 to 1.35; P < 0.00001, I 2 = 69%), an assurance of confidentiality (1.33; 95% CI 1.24 to 1.42) and first class outward mailing (1.11; 95% CI 1.02 to 1.21; P = 0.78, I 2 = 0%). The odds of response were reduced when the questionnaire included questions of a sensitive nature (0.94; 95% CI 0.88 to 1.00; P = 0.51, I 2 = 0%). Electronic: We found 32 eligible trials. The trials evaluated 27 different ways of increasing response to electronic questionnaires. We found substantial heterogeneity among trial results in half of the strategies. The odds of response were increased by more than a half using non-monetary incentives (1.72; 95% CI 1.09 to 2.72; heterogeneity P < 0.00001, I 2 = 95%), shorter e-questionnaires (1.73; 1.40 to 2.13; P = 0.08, I 2 = 68%), including a statement that others had responded (1.52; 95% CI 1.36 to 1.70), and a more interesting topic (1.85; 95% CI 1.52 to 2.26). The odds of response increased by a third using a lottery with immediate notification of results (1.37; 95% CI 1.13 to 1.65), an offer of survey results (1.36; 95% CI 1.15 to 1.61), and using a white background (1.31; 95% CI 1.10 to 1.56). The odds of response were also increased with personalised e-questionnaires (1.24; 95% CI 1.17 to 1.32; P = 0.07, I 2 = 41%), using a simple header (1.23; 95% CI 1.03 to 1.48), using textual representation of response categories (1.19; 95% CI 1.05 to 1.36), and giving a deadline (1.18; 95% CI 1.03 to 1.34). The odds of response tripled when a picture was included in an e-mail (3.05; 95% CI 1.84 to 5.06; P = 0.27, I 2 = 19%). The odds of response were reduced when "Survey" was mentioned in the e-mail subject line (0.81; 95% CI 0.67 to 0.97; P = 0.33, I 2 = 0%), and when the e-mail included a male signature (0.55; 95% CI 0.38 to 0.80; P = 0.96, I 2 = 0%). Authors' conclusions: Health researchers using postal and electronic questionnaires can increase response using the strategies shown to be effective in this systematic review. Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
--------------------------------------------------------------------------------
Reaxys Database Information|
--------------------------------------------------------------------------------
Resumo:
A fluorescent DNA probe containing an anthracene group attached via an anucleosidic linker can identify all four DNA bases at a single site as well as the epigenetic modification C/5-MeC via a hybridisation sensing assay.
Resumo:
Haptoglobin (Hp) is recognised as a major acute phase protein in the bovidae and its presence in serum is used as an indicator of inflammation. A mouse monoclonal antibody (1D9) specific for bovine Hp was labelled with a lanthanide (Eu) chelate and used to develop a competitive immunoassay. This competitive immunoassay allowed direct measurement of Hp in serum and was validated for intra- and interassay coefficients of variation (below 8%). Cross-reactivity with other serum proteins was measured (less than 0.1%) and limits of detection for Hp in serum were established for adult male (0.344 mu g/ml) and adult female cattle (1.589 mu g/ml). The immunoassay was compared with an established haptoglobin-haemoglobin binding assay.