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Shyam Mahabal Vijay Bhaskar Reddy Konala Murali Krishna Mamidi Mohammad Mahboob Kanafi Suniti Mishra Krupa Shankar Rajarshi Pal Ramesh Bhonde 《Cytotechnology》2016,68(4):1009-1018
Human skin has continuous self-renewal potential throughout adult life and serves as first line of defence. Its cellular components such as human epidermal keratinocytes (HEKs) and dermal mesenchymal stromal cells (DMSCs) are valuable resources for wound healing applications and cell based therapies. Here we show a simple, scalable and cost-effective method for sequential isolation and propagation of HEKs and DMSCs under defined culture conditions. Human skin biopsy samples obtained surgically were cut into fine pieces and cultured employing explant technique. Plated skin samples attached and showed outgrowth of HEKs. Gross microscopic examination displayed polygonal cells with a granular cytoplasm and H&E staining revealed archetypal HEK morphology. RT–PCR and immunocytochemistry authenticated the presence of key HEK markers including trans-membrane protein epithelial cadherin (E-cadherin), keratins and cytokeratin. After collection of HEKs by trypsin–EDTA treatment, mother explants were left intact and cultured further. Interestingly, we observed the appearance of another cell type with fibroblastic or stromal morphology which were able to grow up to 15 passages in vitro. Growth pattern, expression of cytoskeletal protein vimentin, surface proteins such as CD44, CD73, CD90, CD166 and mesodermal differentiation potential into osteocytes, adipocytes and chondrocytes confirmed their bonafide mesenchymal stem cell like status. These findings albeit preliminary may open up significant opportunities for novel applications in wound healing. 相似文献
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Evolution of antibiotic resistance genes: the DNA sequence of a kanamycin resistance gene from Staphylococcus aureus 总被引:14,自引:0,他引:14
The kanamycin resistance gene from Staphylococcus aureus has been sequenced
and its structure compared with similar genes isolated from Streptomyces
fradiae and from two transposons, Tn5 and Tn903, originally isolated from
Klebsiella pneumoniae and Salmonella typhimurium, respectively. The genes
are all homologous but, since their common ancestor, have undergone
extensive divergence, with more than 43% divergence between the closest
pair. The phylogeny of the genes cannot be made congruent to the phylogeny
of the taxa from which they were isolated without requiring rather
improbable differences in rates. One is therefore led to conclude that
there have been multiple occurrences of gene transfer between these
species. Thus, although they are homologous, they are neither orthologous
nor paralogous. It is suggested that homologous genes of this type be
called xenologous.
相似文献
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