144 resultados para Stone pathology


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In this work, olive stone (OS) was utilized to investigate its capacity as biosorbent for methylene blue (MB) and Cr(III), which are usually present in textile industry effluents. Equilibrium and kinetic experiments were performed in batch experiments. The biosorption process followed pseudo-second-order kinetics. The equilibrium data were fitted with several models, but Langmuir and Sips models best reproduced the experimental results. Maximum biosorption capacities were 3.296 mg/g (0.0116 mmol/g) and 4.990 mg/g (0.0960 mmol/g) for MB and Cr(III), respectively. Several operation variables, such as
biosorbent mass, flow rate, and initial concentration on the removal of dye and metal, were evaluated in column system. The removal efficiency improved as OS mass increased and decreased when flow rate and initial concentration increased. Also, MB uptake was substantially decreased by increasing the initial concentration of Cr(III), ranging from 6.09 to 2.75 mg/g. These results show that the presence of Cr(III) significantly modifies the biosorption capacity of MB by the OS. These results suggest that OS is a potential low-cost food industry waste for textile industry wastewater treatment.

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The biosorption process of anionic dye Alizarin Red S (ARS) and cationic dye methylene blue (MB) as a function of contact time, initial concentration and solution pH onto olive stone (OS) biomass has been investigated. Equilibrium biosorption isotherms in single and binary systems and kinetics in batch mode were also examined. The kinetic data of the two dyes were better described by the pseudo second-order model. At low concentration, ARS dye appeared to follow a two-step diffusion process, while MB dye followed a three-step diffusion process. The biosorption experimental data for ARS and MB dyes were well suited to the Redlich-Peterson isotherm. The maximum biosorption of ARS dye, qmax = 16.10 mg/g, was obtained at pH 3.28 and the maximum biosorption of MB dye, qmax = 13.20 mg/g, was observed at basic pH values. In the binary system, it was indicated that the MB dye diffuses firstly inside the biosorbent particle and occupies the biosorption sites forming a monodentate complex and then the ARS dye enters and can only bind to untaken sites; forms a tridentate complex with OS active sites.

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Microarray technology has recently accelerated the study of the molecular events involved in prostate cancer, offering the prospect of more precise prognosis and new therapeutic strategies. This review summarises current knowledge of the molecular pathology of prostate cancer. The expression and function of numerous genes have been shown to be altered in prostate cancer. Many of these genes are involved in cell cycle regulation, steroid hormone metabolism or regulation of gene expression. The mechanisms by which androgen independence arises are discussed, including cross-activation, gene amplification and point mutations of the androgen receptor. Analysis of changes in the levels of expression of large numbers of genes during prostate cancer progression have provided a better understanding of the basis of the disease, yielding new molecular markers, such as hepsin, with potential use in diagnosis and prognosis.

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Molecular techniques have a key role to play in laboratory and clinical haematology. Restriction enzymes allow nucleic acids to be reduced in size for subsequent analysis. In addition they allow selection of specific DNA or RNA sequences for cloning into bacterial plasmids. These plasmids are naturally occuring DNA molecules which reside in bacterial cells. They can be manipulated to act as vehicles or carriers for biologically and medically important genes, allowing the production of large amounts of cloned material for research purposes or to aid in the production of medically important recombinant molecules such as insulin. As acquired or inherited genetic changes are implicated in a wide range of haematological diseases, it is necessary to have highly specific and sensitive assays to detect these mutations. Most of these techniques rely on nucleic acid hybridisation, benefitting from the ability of DNA or RNA to bind tighly to complimentary bases in the nucleic acid structure. Production of artificial DNA molecules called probes permits nucleic acid hybridiation assays to be performed, using the techniques of southern blotting or dot blot analysis. In addition the base composition of any gene or region of DNA can be determined using DNA sequencing technology. The advent of the polymerase chain reaction (PCR) has revolutionised all aspects of medicine, but has particular relevance in haematology where easy access to biopsy material provides a wealth of material for analysis. PCR permits quick and reliable manipulation of sample material and its ability to be automated makes it an ideal tool for use in the haematology laboratory.

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Molecular Medicine and Molecular Pathology are integral parts of Haematology as we enter the new millennium. Their origins can be linked to fundamental developments in the basic sciences, particularly genetics, chemistry and biochemistry. The structure of DNA and the genetic code that it encrypts are the critical starting points to our understanding of these new disciplines. The genetic alphabet is a simple one, consisting of just 4 letters, buts its influence is crucial to human development and differentiation. The concept of a gene is not a new one but the Human Genome Project (a joint world-wide effort to characterise our entire genetic make-up) is providing an invaluable understanding of how genes function in normal cellular processes and pinpointing how disruption of these processes can lead to disease. Transcription and translation are the key events by which our genotype is converted to our phenotype (via a messenger RNA intermediate), producing the myriad proteins and enzymes which populate the cellular factory of our body. Unlike the bacterial or prokaryotic genome, the human genome contains a large amount of non coding DNA (less than 1% of our genome codes for proteins), and our genes are interrupted, with the coding regions or exons separated by non coding introns. Precise removal of the intronic material after transcription (though a process called splicing) is critical for efficient translation to occur. Incorrect splicing can lead to the generation of mutant proteins, which can have a dilaterious effect on the phenotype of the individual. Thus the 100,000-200,000 genes which are present in each cell in our body have a defined control mechanism permitting efficient and appropriate expression of proteins and enzymes and yet a single base change in just one of those genes can lead to diseases such as haemophilia or fanconis anaemia.

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Background: Identifying new and more robust assessments of proficiency/expertise (finding new "biomarkers of expertise") in histopathology is desirable for many reasons. Advances in digital pathology permit new and innovative tests such as flash viewing tests and eye tracking and slide navigation analyses that would not be possible with a traditional microscope. The main purpose of this study was to examine the usefulness of time-restricted testing of expertise in histopathology using digital images.
Methods: 19 novices (undergraduate medical students), 18 intermediates (trainees), and 19 experts (consultants) were invited to give their opinion on 20 general histopathology cases after 1 s and 10 s viewing times. Differences in performance between groups were measured and the internal reliability of the test was calculated.
Results: There were highly significant differences in performance between the groups using the Fisher's least significant difference method for multiple comparisons. Differences between groups were consistently greater in the 10-s than the 1-s test. The Kuder-Richardson 20 internal reliability coefficients were very high for both tests: 0.905 for the 1-s test and 0.926 for the 10-s test. Consultants had levels of diagnostic accuracy of 72% at 1 s and 83% at 10 s.
Conclusions: Time-restricted tests using digital images have the potential to be extremely reliable tests of diagnostic proficiency in histopathology. A 10-s viewing test may be more reliable than a 1-s test. Over-reliance on "at a glance" diagnoses in histopathology is a potential source of medical error due to over-confidence bias and premature closure.

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The Middle Stone Age (MSA) covers the evolution, emergence, and dispersal of Homo sapiens. This article focuses on archaeological data and on published material from key stratified sites with some form of geochronological control from across eastern Africa. The MSA is often characterised by a shift from handaxe production towards discoidal and Levallois techniques. Although evidence for the controlled use of fire remains minimal, it seems likely that MSA hominins used it, as well as being highly skilled in working stone and probably bone and wood. MSA hominins appear to have exploited a range of different ecozones and many MSA sites are focused on ecotones, maximising access to resources. Over time, use of rockshelters and caves also seems to have increased. Although much work remains, the MSA is presently one of the most exciting and dynamic periods in the study of human evolution.

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Small bowel accounts for only 0.5% of cancer cases in the US but incidence rates have been rising at 2.4% per year over the past decade. One-third of these are adenocarcinomas but little is known about their molecular pathology and no molecular markers are available for clinical use. Using a retrospective 28 patient matched normal-tumor cohort, next-generation sequencing, gene expression arrays and CpG methylation arrays were used for molecular profiling. Next-generation sequencing identified novel mutations in IDH1, CDH1, KIT, FGFR2, FLT3, NPM1, PTEN, MET, AKT1, RET, NOTCH1 and ERBB4. Array data revealed 17% of CpGs and 5% of RNA transcripts assayed to be differentially methylated and expressed respectively (p < 0.01). Merging gene expression and DNA methylation data revealed CHN2 as consistently hypermethylated and downregulated in this disease (Spearman -0.71, p < 0.001). Mutations in TP53 which were found in more than half of the cohort (15/28) and Kazald1 hypomethylation were both were indicative of poor survival (p = 0.03, HR = 3.2 and p = 0.01, HR = 4.9 respectively). By integrating high-throughput mutational, gene expression and DNA methylation data, this study reveals for the first time the distinct molecular profile of small bowel adenocarcinoma and highlights potential clinically exploitable markers.

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Professor Manuel Salto-Tellez of Queen’s University, Belfast, Northern Ireland is an expert histopathologist and molecular diagnostician. Professor Salto-Tellez is a lead investigator at the Northern Ireland Molecular Pathology Laboratory and also serves as a member of the Editorial Advisory Board for Expert Review of Molecular Diagnostics. In this interview, he proposes directions for the future of molecular pathology and molecular diagnostics, integrating all aspects of pathology toward a common goal.

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Molecular testing is becoming an important part of the diagnosis of any patient with cancer. The challenge to laboratories is to meet this need, using reliable methods and processes to ensure that patients receive a timely and accurate report on which their treatment will be based. The aim of this paper is to provide minimum requirements for the management of molecular pathology laboratories. This general guidance should be augmented by the specific guidance available for different tumour types and tests. Preanalytical considerations are important, and careful consideration of the way in which specimens are obtained and reach the laboratory is necessary. Sample receipt and handling follow standard operating procedures, but some alterations may be necessary if molecular testing is to be performed, for instance to control tissue fixation. DNA and RNA extraction can be standardised and should be checked for quality and quantity of output on a regular basis. The choice of analytical method(s) depends on clinical requirements, desired turnaround time, and expertise available. Internal quality control, regular internal audit of the whole testing process, laboratory accreditation, and continual participation in external quality assessment schemes are prerequisites for delivery of a reliable service. A molecular pathology report should accurately convey the information the clinician needs to treat the patient with sufficient information to allow for correct interpretation of the result. Molecular pathology is developing rapidly, and further detailed evidence-based recommendations are required for many of the topics covered here.

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The pathogenesis of Alzheimer's disease (AD) is complex involving multiple contributing factors. The extent to which AD pathology impacts upon the metabolome is still not understood, nor is it known how disturbances change as the disease progresses. For the first time we have profiled longitudinally (6, 8, 10, 12 and 18 months) both the brain and plasma metabolome of APP/PS1 double transgenic and wild type (WT) mice. A total of 187 metabolites were quantified using a targeted metabolomics methodology. Multivariate statistical analysis produced models that distinguished APP/PS1 from WT mice at 8, 10 and 12 months.Metabolic pathway analysis found perturbed polyamine metabolism in both brain and blood plasma. There were other disturbances in essential amino acids,branched chain amino acids and also in the neurotransmitter serotonin.Pronounced imbalances in phospholipid and acylcarnitine homeostasis was evident in two age groups. AD-like pathology therefore impacts greatly on both the brain and blood metabolomes, although there appears to be a clear temporal sequence whereby changes to brain metabolites precede those in blood.