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Well-characterized Population (well-characterized + population)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Stem cells: A minireview

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue S38 2002
Kathyjo A. Jackson
Abstract The identification of adult-derived stem cells which maintain plasticity throughout the course of a lifetime, has transformed the field of stem cell biology. Bone marrow derived hematopoietic stem cells (HSC) are the most well-characterized population of these multipotential cells. First identified for their ability to reconstitute blood lineages and rescue lethally irradiated hosts, these cells have also been shown to differentiate and integrate into skeletal muscle, cardiac myocytes, vascular endothelium, liver, and brain tissue. Various populations of HSC are being studied, exploiting cell surface marker expression, such as Sca-1, c-kit, CD34, and lin,; as well as the ability to efflux the vital dye Hoecsht 33342. Detection of engrafted donor derived cells into various tissue types in vivo is a laborious process and may involve detection of ,-galactosidase via colorimetric reaction or antibody labeling or green fluorescent protein (GFP) via fluorescence microscopy, as well as in situ hybridization to detect the Y-chromosome. Using these techniques, the search has begun for tissue specific stem cells capable of host tissue regeneration, self renewal, and transdifferentiation. Caution is urged when interpreting these types of experiments because although they are stimulating, limitations of the technologies may provide misleading results. J. Cell. Biochem. Suppl. 38: 1,6, 2002. © 2002 Wiley-Liss, Inc. [source]

Putative heterotopic ossification progenitor cells derived from traumatized muscle,

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2009
Wesley M. Jackson
Abstract Heterotopic ossification (HO) is a frequent complication following combat-related trauma, but the pathogenesis of traumatic HO is poorly understood. Building on our recent identification of mesenchymal progenitor cells (MPCs) in traumatically injured muscle, the goal of this study was to evaluate the osteogenic potential of the MPCs in order to assess the role of these cells in HO formation. Compared to bone marrow-derived mesenchymal stem cells (MSCs), a well-characterized population of osteoprogenitor cells, the MPCs exhibited several significant differences during osteogenic differentiation and in the expression of genes related to osteogenesis. Upon osteogenic induction, MPCs showed increased alkaline phosphatase activity, production of a mineralized matrix, and up-regulated expression of the osteoblast-associated genes CBFA1 and alkaline phosphatase. However, MPCs did not appear to reach terminal differentiation as the expression of osteocalcin was not substantially up-regulated. With the exception of a few genes, the osteogenic gene expression profile of traumatized muscle-derived MPCs was comparable to that of the MSCs after osteogenic induction. These findings indicate that traumatized muscle-derived MPCs have the potential to function as osteoprogenitor cells when exposed to the appropriate biochemical environment and are the putative osteoprogenitor cells that initiate ectopic bone formation in HO. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1645,1651, 2009 [source]

IgE sensitization, respiratory allergy symptoms, and heritability independently increase the risk of otitis media with effusion

ALLERGY, Issue 3 2006
F. M. Chantzi
Background and aims:, Epidemiological evidence examining the role of atopy and/or allergy in the pathogenesis of otitis media with effusion (OME) is inconclusive. The aim of this study was to assess any increased risk for OME attributable to allergy-related factors, in a well-characterized population using a case-control design and multivariate analysis. Subjects and methods:, Eighty-eight 1,7-year-old children with OME, diagnosed by clinical and tympanometric evaluation and 80 matched controls were enrolled. A standardized questionnaire was completed, in order to assess factors related to OME and allergy-related symptoms and diagnoses using strict clinical definitions. Specific IgE was measured by skin-prick tests and/or CAP-FEIA. Results:, The patient and control groups were well matched. Factors conferring increased risk for OME in the univariate analysis included IgE sensitization, dyspnea, wheezing, asthma, paroxysmal sneezing, rhinitis, eczema, ,any allergic disease,' family history of otitis media, and family history of allergy. After multivariate analysis IgE sensitization, wheezing, nasal obstruction, family history of otitis, and child-care attendance remained as independent risk factors for development of OME. Conclusion:, IgE sensitization and respiratory allergy symptoms are independent risk factors for the development of OME, suggesting that both immunological and mechanical pathways may contribute to the development of the disease. Otitis heritability provides additional risk, as well as frequent exposure to viral upper respiratory tract infections in children attending daycare. Treatment and/or prevention of OME using anti-allergic medications should be further examined. [source]

Kiwifruit allergy: actinidin is not a major allergen in the United Kingdom

CLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2007
J. S. A. Lucas
Summary Background Actinidin has previously been reported as the major allergen in kiwifruit. Objectives To investigate the relevance of actinidin in a well-characterized population of UK patients with kiwifruit allergy. Methods To identify the allergens in kiwifruit, using Western blots, we examined the IgE-binding patterns of 76 patients with a history of kiwifruit allergy, 23 of who had had a positive double-blind, placebo-controlled food challenge. In addition, IgE binding to purified native actinidin was studied in 30 patients, and to acidic and basic isoforms of recombinant actinidin in five patients. Inhibition of IgE binding to kiwifruit protein extract by purified native actinidin was investigated by both inhibition immunoblots and inhibition ELISAs using pooled sera. Results Twelve protein bands in kiwifruit protein extract were bound by IgE. A protein band with a molecular weight of 38 kDa was the major allergen recognized by 59% of the population. IgE did not bind to actinidin in the kiwifruit protein extract, or to purified native or recombinant forms of actinidin during Western blotting. Pooled sera bound to kiwifruit protein extract but not purified actinidin on ELISA, and pre-incubating sera with actinidin did not inhibit IgE binding to kiwifruit protein extract on immunoblot or ELISA. Conclusion A novel 38 kDa protein, not actinidin, is the major allergen in this large study population. Identification of major allergens in one patient group is therefore not necessarily reproducible in another; therefore, major allergens should not be defined until there is a sufficient body of data from diverse geographical and cultural populations. [source]