Aquacel Ag with Vaseline gauze in the management of toxic epidermal necrolysis (TEN).

UNLABELLED: Toxic epidermal necrolysis (TEN) is a rare condition with potentially high mortality and involves severe exfoliative disease of the skin and mucous membranes induced by drugs. The reported fatality of TEN varies widely from 20% to 60%. The technique for TEN wound coverage described in this article involves the use of various dressings. PATIENTS AND METHODS: Nine women with histologically confirmed TEN (>30% total body surface area, TBSA) were treated at our burn intensive care unit. All patients received hydrotherapy and wounds were covered with Aquacel Ag and Vaseline gauzes onlay. Following this, elastic cotton bandage was wrapped around the dressing. The dressing was changed and the wound evaluated twice a week. Efficacy was established by the wound achieving>or=95% re-epithelialisation of the study area. RESULTS: The mean age was 60.1 years (range from 7 to 88 years). The percentage of body surface area affected by epidermal slough ranged from 30% to 85% TBSA, with a mean of 51%. One patient expired due to severe sepsis on day 3. Eight patients achieved over 95% wound healing. All wounds healed well without the need for skin grafting. However, two of them expired on day 14 and day 20 because of pneumonia and retention of carbon dioxide, respectively. The average duration to achieve 95% wound healing was 10.4 days in eight cases (range from 7 to 14 days). No adverse reactions were noted. CONCLUSION: Aquacel Ag dressing can be easily removed during hydrotherapy. The wound pain is reduced. By changing the dressing just twice a week, we were able to evaluate the wound directly, decrease the odour and increase the quality of life of the patients. In addition, lower frequency of dressing changes decreases the manpower requirements and is cost effective. Use of Aquacel Ag with Vaseline gauze is a good alternative for the management of TEN wounds.

Isolation and characterization of human gastric cell lines with stem cell phenotypes.

AIM: The aim of this study was to develop an in vitro human gastric stem and/or progenitor cell model that may be used to study the mechanism of gastric carcinogenesis induced by Helicobacter pylori infection. METHODS: Human gastric biopsy was minced and digested with collagenase and dispase and cultured in a low-calcium medium (serum-free keratinocyte medium; keratinocyte-SFM) supplemented with N-acetyl-L-cysteine and L-ascorbic acid 2-phosphate. Actively proliferating epithelial colonies with sustained growth were isolated and characterized for karyotype and phenotypes related to stem cell characteristics including proliferation and differentiation potential, ability of anchorage-independent growth (AIG), gap junctional intercellular communication (GJIC) and the expression of Oct-4, a transcription factor previously shown to be expressed in embryonic stem cells, adult stem cells and undifferentiated tumor cells. To study the carcinogenic effect of H. pylori infection, gastric stem and/or progenitor cells were incubated with H. pylori culture products and/or N-methyl-N-nitro-N-nitrosoguanidine (MNNG), a chemical carcinogen, to see the telomerase activation. RESULTS: Multiple cell lines with stem cell features were isolated by this new cell culture method. The results based on detailed characterization of one cell clone, KMU-GI2, revealed stem cell features of these cells. The initial clone contained mostly undifferentiated epithelial-like cells, which, upon subculture and propagation, gave rise to a heterogeneous cell population. Single cell-derived subclones, similar to the parental population, retained high differentiation potential and were capable of giving rise to many morphologically different cell types (i.e. epithelial-like, glial or neuron-like, round and various peculiar-shaped cells). Although these cells were normal in karyotype and competent in GJIC, they had the ability to grow in soft agar. Cells expressing epithelial membrane antigen (EMA), mucin 5AC, glial fibrillary acidic protein (GFAP), cytokeratin-18 (CK-18), trefoil factor 1 (TFF-1) and Oct-4 were found in the cell culture, but not E-cadherin-, gastrin- or telomerase-expressing cells. Furthermore, spontaneously immortalized non-tumorigenic clones could be derived from the cell population. After treating these cell cultures with the chemical carcinogen, MNNG and H. pylori culture products for 5 days, telomerase activity and telomerase mRNA expression were significantly elevated, while treatment with either of them showed no effect. CONCLUSION: The new cell culture method can be used to develop gastric epithelial cell clones with sustained growth from endoscopic biopsy. The gastric cell clone showed several stem and/or progenitor cell phenotypes (i.e. the ability of AIG, high differentiation capacity, high susceptibility to spontaneous immortalization and the expression of Oct-4). The telomerase expression in these gastric stem and/or progenitor cells can be upregulated by exposure to H. pylori culture products and MNNG, an important step in neoplastic transformation. These results show that putative human gastric stem and/or progenitor cell clones can be developed by our method and these cells could be useful for studying the mechanisms of human gastric carcinogenesis including the mechanism of action of H. pylori, as well as the regulation of the proliferation and differentiation of human gastric mucosa.

Accelerated growth and prolonged lifespan of adipose tissue-derived human mesenchymal stem cells in a medium using reduced calcium and antioxidants.

Human mesenchymal stem cells (MSCs) have been isolated from bone marrow and other adult tissues and are potentially useful for tissue engineering. Adipose tissue has several clear advantages as a starting material for harvesting stem cells, as it is abundant and relatively easy to procure. However, existing methods to expand adipose-derived MSCs are less than optimal. Here we describe a new cell culture method that accelerates greatly the growth rate and prolongs the lifespan of adipose MSCs. This was accomplished by using a growth medium with low calcium and supplemented with N-acetyl-L-cysteine and L-ascorbic acid-2-phosphate. Cells produced early in these cultures displayed characteristics similar to those previously reported for multipotential stem cells, including a high frequency of anchorage- independent growth in soft agar, lack of gap junctional intercellular communication in a cell type with serpiginous morphology, and the expression of Oct-4. Furthermore, these cells could readily be induced to differentiate into adipocytes, osteoblasts, and chondrocytes. Thus, modification of growth medium by reduction of calcium and addition of antioxidants greatly enhanced the growth rate and extended the lifespan of adipose-derived multipotential human MSCs.