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Marker Studies (marker + studies)
Selected AbstractsDifferential expression of periodontal ligament-specific markers and osteogenic differentiation in human papilloma virus 16-immortalized human gingival fibroblasts and periodontal ligament cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2007S.-H. Pi Background and Objective:, Periodontal ligament cells and gingival fibroblasts are important in the remodeling of periodontal tissue, but human papilloma virus (HPV)16-immortalized cell lines derived from human periodontal ligament cells and gingival fibroblasts has not been characterized. The purpose of this study was to establish and differentially characterize the immortalized cell lines from gingival fibroblasts and periodontal ligament by HPV16 transfection. Material and Methods:, Cell growth, cell cycle analysis, western blot for cell cycle regulatory proteins and osteogenic differentiation markers, and reverse transcription,polymerase chain reaction for periodontal ligament-specific markers were performed. Results:, Both immortalized cell lines (immortalized gingival fibroblasts and immortalized periodontal ligament cells) grew faster than primary cultured gingival fibroblasts or periodontal ligament cells. Immortalized gingival fibroblasts and immortalized periodontal ligament cells overexpressed proteins p16 and p21, and exhibited degradation of proteins pRb and p53, which normally cause cell cycle arrest in G2/M-phase. Western blotting and reverse transcription,polymerase chain reaction for periodontal ligament-specific and osteogenic differentiation marker studies demonstrated that a cell line, designated IPDL, mimicked periodontal ligament gene expression for alkaline phosphatase, osteonectin, osteopontin, bone sialoprotein, bone morphogenic protein-2, periostin, S-100A4 and PDLs17. Conclusion:, These results indicate that IPDL and immortalized gingival fibroblast cell lines consistently retain normal periodontal ligament and gingival fibroblast phenotypes, respectively, and periodontal ligament markers and osteogenic differentiation in IPDL are distinct from immortalized gingival fibroblast cells. [source] Histologic classification of ductal carcinoma in situMICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2002Shabnam Jaffer Abstract Prior to the current mammographic era, ductal carcinoma in situ (DCIS) usually presented as a large mass, was classified morphologically by architecture, and treated by mastectomy. The introduction of screening mammography led to an increase in the incidence of DCIS, a decrease in the average size of DCIS, and an increased emphasis on its heterogeneous nature. Thus, a reproducible and prognostically relevant classification system for DCIS is necessary. The ultimate goal of this classification is proper selection of patients for whom lumpectomy would suffice rather than mastectomy. Features to evaluate include: extent and size of disease, adequacy of resection margins, and histology. While none of the proposed histological classification systems were endorsed at the recent Consensus Conference on the Classification of DCIS, nuclear grade was the most important feature common to most of them. Architecture was given secondary importance. By definition, DCIS is a non-invasive clonal proliferation of epithelial cells originating in the terminal duct lobular unit, which would be expected to be monomorphic; however, it is the degree of nuclear pleomorphism that is primarily used to separate DCIS into low, intermediate, and high grades. Architecturally, DCIS has been divided into the following types: comedo, solid, cribriform, micropapillary, and papillary. Different architectural patterns and grades may be present in a given particular case; however, some combinations of patterns occur more frequently than others. Interobserver studies have shown nuclear grading to be interpreted with greater consistency than architecture, and nuclear grading methods have correlated with biological and molecular marker studies. Microsc. Res. Tech. 59:92,101, 2002. © 2002 Wiley-Liss, Inc. [source] Population structure of the Southeast Asian river catfish Mystus nemurusANIMAL GENETICS, Issue 6 2003S. Usmani Summary A total of 143 microsatellites were isolated from Mystus nemurus using a 5, anchored polymerase chain reaction technique or the random amplified hybridization microsatellite method, the first set of microsatellite markers developed for the Southeast Asian river catfish. Twenty polymorphic microsatellite loci were used as markers for population characterization of M. nemurus from six different geographical locations in Malaysia (Perak, Kedah, Johor, UPM, Sarawak and Terengganu). The number of alleles per locus ranged from 2 to 11 with 6.3 as the average number of alleles per locus. Characterization of the populations showed relatively high levels of genetic variation compared with previous studies using allozyme markers. The highest genetic similarity was found between Perak and Kedah, while the highest genetic distance was found between Terengganu and Kedah. The majority of clustering was in accordance with geographical locations and the histories of the populations. Microsatellite analysis indicated that the Sarawak population might be genetically closer to the Peninsular Malaysian populations than has been previously shown by other molecular marker studies. [source] Prenatal diagnosis for risk of spinal muscular atrophyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 11 2002I. Cuscó Objectives Prenatal diagnosis of spinal muscular atrophy is usually performed in high risk couples by detection of a homozygous deletion in the survival motor neurone gene (SMN1). However, other relatives at risk of being carriers very often request genetic counselling and the possibility of prenatal diagnosis. The aim of this study was to validate a SMN1 gene quantitative test to help the couples formed by one spinal muscular atrophy carrier and a partner of the general population (1/200 potential risk) to achieve a less ambiguous risk result for the pregnancy. Design Spinal muscular atrophy carrier studies in at-risk individuals. Setting Department of Genetics and Gynaecology and Obstetrics in a large university hospital. Population Seventy-nine obligate carriers (more than one affected child with deletion in the offspring) and 58 non-carriers (relatives of spinal muscular atrophy families defined by marker studies) were tested to set up a quantitative analysis. The method was applied in different situations in 126 members from 34 families with spinal muscular atrophy patients. Methods DNA studies of the SMN1 gene by marker analysis and quantitative assay. Main outcome measures To determine double (non-carrier) or single dose (carrier) of exon 7 of the SMN1 gene in relatives of spinal muscular atrophy patients. Bayesian calculation of risk. Results The sensitivity and specificity of the method were 96% and 100%, respectively. Studies on different couples with an a priori risk of 1/200 allowed us to reduce the final risk to 1/5000 or to increase it to 1/4. Conclusions The quantitative method can be used to achieve a less ambiguous risk in pregnancies with a 1/200 risk and in families where no sample is available to study the index case. Screening of gamete donors when the recipient is a known carrier should also be considered. [source] 2333: Cultivation of limbal stem cells-derived corneal epithelium on different biologic materials for clinical transplantationACTA OPHTHALMOLOGICA, Issue 2010G PETROVSKI Purpose To develop simple, reproducible, animal-materials free method for cultivating limbal stem-cells and differentiating them into corneal epithelium on different human biologic materials for clinical transplantation. Methods The limbal tissues (2x2mm) were harvested from cadavers not more than 8 hours after death and proliferated in vitro on cell culture tissue plates, human amniotic membranes (HAM) or human lens capsules in medium containing human AB serum. Cell viability was tested using the MTT assay and annexin-FITC/Propidium Iodide positivity methods. Molecular gene and immunofluorescent marker studies for stemness, proliferation and differentiation were used for the analysis. Results Over a period of one year, 50 limbal tissue explants were cultivated. Emergence of cells at one edge of the explants occurred within 24 hours from culturing and formed monolayer within 14 days. Although the speed of cell growth varied among donors and types of media for growth, inadequate growth at two weeks was never recorded. The viability of the cells at 7 and 14 days of cultivation was higher than 96% except in case of HAM use where viability was below 80%. The growing cells were characterized for their positivity for stemness (P63, ABCG2), proliferation (ki67) and epithelial cell markers CK 3, 8, 12, 14, 18 and 19. Conclusion We demonstrate a simple, animal-materials free technique for generating corneal epithelium from cadavers or alternatively from autologous donors for viable cell growth on different biologic materials for transplantation. The growth of corneal epithelium on lens capsules proved to be superior compared to the other cultivation techiques. [source] Using fractional exhaled nitric oxide to guide asthma therapy: design and methodological issues for ASthma TReatment ALgorithm studiesCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2009P. G. Gibson Prof. Summary Background Current asthma guidelines recommend treatment based on the assessment of asthma control using symptoms and lung function. Noninvasive markers are an attractive way to modify therapy since they offer improvedselection of active treatment(s) based on individual response, and improvedtitration of treatment using markers that are better related to treatment outcomes. Aims: To review the methodological and design features of noninvasive marker studies in asthma. Methods Systematic assessment of published randomized trials of asthma therapy guided by fraction of exhaled nitric oxide(FENO). Results FENO has appeal as a marker to adjust asthma therapy since it is readily measured, gives reproducible results, and is responsive to changes in inhaled corticosteroid doses. However, the five randomised trials of FENO guided therapy have had mixed results. This may be because there are specific design and methodological issues that need to be addressed in the conduct of ASthma TReatment ALgorithm(ASTRAL) studies. There needs to be a clear dose response relationship for the active drugs used and the outcomes measured. The algorithm decision points should be based on outcomes in the population of interest rather than the range of values in healthy people, and the algorithm used needs to provide a sufficiently different result to clinical decision making in order for there to be any discernible benefit. A new metric is required to assess the algorithm performance, and the discordance:concordance(DC) ratio can assist with this. Conclusion Incorporating these design features into future FENO studies should improve the study performance and aid in obtaining a better estimate of the value of FENO guided asthma therapy. [source] | ||||||||||