950 resultados para refrigerator samples
Resumo:
A total of 2538 quarter milk samples from 638 lactating dairy cows from 47 farms in the canton of Bern, Switzerland, were investigated for streptococci. A novel, simple and inexpensive laboratory method was used for the differentiation of Streptococcus species, and a risk factor analysis was carried out. The prevalence in the quarter milk samples was 0.2 per cent for Streptococcus agalactiae, 1.3 per cent for Streptococcus uberis, 1.3 per cent for Streptococcus dysgalactiae, 0.1 per cent for Enterococcus species and 2.9 per cent for minor Streptococcus species (designated Streptococcus-Lactococcus-Enterococcus [SLE] group). Based on the somatic cell count (SCC), S uberis and S dysgalactiae were classified as 'major' pathogens and the bacteria in the SLE group as 'minor' pathogens. For S uberis, S dysgalactiae and bacteria in the SLE group, the most significant risk factor was an intramammary infection (IMI) of a neighbouring quarter by the same pathogen. Other significant risk factors for S uberis infection were a positive California Mastitis Test (CMT) result and a SCC of more than 100,000 cells/ml. Significant risk factors for IMI with S dysgalactiae were a positive CMT result, teat injury and palpable abnormalities in the udder. Infection with bacteria in the SLE group was significantly associated with a SCC of more than 100,000 cells/ml, a lactation number of more than 2, the right rear quarter (as the location of infection) and a positive CMT result.
Resumo:
Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030.
Resumo:
A capillary electrophoresis method with contactless conductivity detection was evaluated as a new approach for quantification of creatine and phosphocreatine in human quadriceps femoris biopsy samples. The running buffers employed consisted of 1 M acetic acid at a pH of 2.3 for the determination of creatine and 50 mM 3-(N-morpholino)propanesulfonic acid/30 mM histidine at a pH of 6.4 for the determination of phosphocreatine in the centrifuged muscle extracts. The limits of detection for creatine and phosphocreatine were found to be 2.5 and 1.0 μM, respectively. Creatine and phosphocreatine were determined in six human muscle biopsy samples and the results were found comparable to those of a standard enzymatic assay. The procedures developed for creatine and phosphocreatine also allow the determination of creatinine as well as adenosine diphosphate and adenosine triphosphate.
Resumo:
This project had a threefold aim and sought to provide answers to several different questions. Kossowska first focused on the relationship between Openness to Experience and ideological variables such as authoritarianism and conservatism. The main questions here were (1) whether there are differences between the Polish and Belgian samples studied with respect to the relationship between political ideology and Openness to Experience, and (2) whether this relationship applies to all facets of Openness to Experience. The study showed significant negative correlations between Openness and right-wing ideology in both adult samples, and that Fantasy and Actions were the most robust correlates of political ideology. A second problem examined concerned the relationship between ideology and cognitive functioning. The important questions here were about the conceptualisation and measurement of cognitive variables such as rigidity, intolerance of ambiguity, or the need for closure, which determine individuals' attitudes to politics. The results confirmed the significance of the need for closure construct in both samples for understanding the process of formulating and holding political beliefs. The last aspect of the study was the differences in political beliefs between the Polish and Belgian samples in relation to the social, political and economic situation in the two countries. The most important question here was the changes in the political mentality of Poles during the period of system transition. Kossowska expected to find differences between Poles and Belgians with respect to the level of conservatism and authoritarianism, but in fact both samples showed comparable levels of right-wing political beliefs.
Resumo:
To investigate the serum level distribution of angiogenic markers (PlGF, endoglin, sFlt-1) and acute-phase proteins (SAA, CRP) in patients with HELLP syndrome or preeclampsia (PE) including matched controls.
Resumo:
A robust, inexpensive, and fully validated CE method for the simultaneous determination of the enantiomers of propafenone (PPF), 5-hydroxy-propafenone (5OH-PPF) and N-despropyl-propafenone (NOR-PPF) in serum and in in vitro media is described. It is based upon liquid-liquid extraction at alkaline pH followed by analysis of the reconstituted extract by CE in presence of a pH 2.0 running buffer composed of 100 mM sodium phosphate, 19% methanol, and 0.6% highly sulfated beta-CD. For each compound, the S-enantiomers are shown to migrate ahead of their antipodes, and the overall run time is about 30 min. Enantiomer levels between 25 and 1000 ng/mL provide linear calibration graphs, and the LOD for all enantiomers is between 10 and 12 ng/mL. The assay is shown to be suitable for the determination of the enantiomers of PPF and its metabolites in in vitro incubations comprising human liver microsomes or single CYP450 enzymes (SUPERSOMES). Incubations with CYP2D6 SUPERSOMES revealed, for the first time, the simultaneous formation of the enantiomers of 5OH-PPF and NOR-PPF with that enzyme. CE data can be used for the evaluation of the enzymatic N-dealkylation and hydroxylation rates.
Resumo:
P-glycoprotein (p-gp) is a transmembrane protein functioning as a drug-efflux pump in the intestinal epithelium. Human patients with inflammatory bowel disease (IBD) who fail to respond to treatment with steroids express high levels of p-gp in lamina propria lymphocytes. The purpose of this study was to investigate p-gp expression in duodenal biopsy samples of dogs with chronic enteropathies and to evaluate the expression of p-gp after treatment with a known inducer of p-gp (prednisolone). Duodenal biopsy samples from 48 dogs were evaluated immunohistochemically with the mouse monoclonal antibody C219 for expression of p-gp in lamina propria lymphocytes. Biopsy samples were available from 15 dogs after treatment with prednisolone and 16 dogs after dietary therapy alone ("elimination diet"). Treatment with prednisolone resulted in an increase in p-gp expression (P=0.005). In contrast, dietary treatment alone produced no significant change in p-gp expression (P=0.59). A low p-gp score before initiation of steroid treatment was significantly associated with a positive response to treatment (P=0.01). These results indicate that lamina propria lymphocyte expression of p-gp is upregulated after prednisolone treatment in dogs with IBD, and that mucosal expression of p-gp may be of value in predicting the response to therapy.
Resumo:
Imaging of biological samples has been performed with a variety of techniques for example electromagnetic waves, electrons, neutrons, ultrasound and X-rays. Also conventional X-ray imaging represents the basis of medical diagnostic imaging, it remains of limited use in this application because it is based solely on the differential absorption of X-rays by tissues. Coherent and bright photon beams, such as those produced by third-generation synchrotron X-ray sources, provide further information on subtle X-ray phase changes at matter interfaces. This complements conventional X-ray absorption by edge enhancement phenomena. Thus, phase contrast imaging has the potential to improve the detection of structures on images by detecting those structures that are invisible with X-ray absorption imaging. Images of a weakly absorbing nylon fibre were recorded in in-line holography geometry using a high resolution low-noise CCD camera at the ESRF in Grenoble. The method was also applied to improve image contrast for images of biological tissues. This paper presents phase contrast microradiographs of vascular tree casts and images of a housefly. These reveal very fine structures, that remain invisible with conventional absorption contrast only.
Resumo:
BACKGROUND: There are inherent conceptual problems in investigating the pharmacodynamics of cancer drugs in vivo. One of the few possible approaches is serial biopsies in patients. However, this type of research is severely limited by methodological and ethical constraints. MATERIALS AND METHODS: A modified 3-dimensional tissue culture technique was used to culture human tumor samples, which had been collected during routine cancer operations. Twenty tumor samples of patients with non-small cell lung cancer (NSCLC) were cultured ex vivo for 120 h and treated with mitomycin C, taxotere and cisplatin. The cytotoxic activity of the anticancer agents was quantified by assessing the metabolic activity of treated tumor cultures and various assays of apoptosis and gene expression were performed. RESULTS: The proliferative activity of the tissue was maintained in culture as assessed by Ki-67 staining. Mitomycin C, cisplatin and taxotere reduced the metabolic activity of the tumor tissue cultures by 51%, 29% and 20%, respectively, at 120 h. The decrease in metabolic activity corresponded to the induction of apoptosis as demonstrated by the typical morphological changes, such as chromatin condensation and nuclear fragmentation. In addition, activated caspase-3 could be verified in apoptotic cells by immunohistochemistry. To verify functional aspects of apoptosis, the induction of chemotherapy-induced cell death was inhibited with the caspase inhibitor z-VAD.fmk. RNA was extracted from the tissue cultures after 120 h of ex vivo drug treatment and was of sufficient quality to allow quantitative PCR. CONCLUSION: The 3-dimensional ex vivo culture technique is a useful method to assess the molecular effects of pharmacological interventions in human cancer samples in vitro. This culture technique could become an important tool for drug development and for the prediction of in vivo drug efficacy.