ABSTRACT
In this study, the effectiveness of a tissue-engineered skin (Activskin; Aierfu, Xi'an, China) was evaluated for the treatment of various refractory ulcers. These ulcers were treated with Activskin after debridement and irrigation with saline. A second application of Activskin was essential if the first application failed to persist on the wounds. Clinical efficacy and safety were assessed at regular clinic visits during 6 months of follow-up. All 11 treated patients improved with Activskin. The ulcers healed by inward migration from the wound edge. The average healing time was 27.8 days. No recurrent ulceration or other adverse events were observed during follow-up. These results provide preliminary evidence that Activskin is safe and effective in the management of refractory ulcers.
Subject(s)
Skin Ulcer/therapy , Skin, Artificial , Tissue Engineering , Adult , Aged , Aged, 80 and over , Diabetic Foot/therapy , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pressure Ulcer/therapy , Retreatment , Skin Ulcer/pathology , Treatment Outcome , Wound HealingABSTRACT
A rapid and efficient yeast transformation procedure has been developed through investigation of factors affecting transformation efficiency. The manipulation of the entire procedure can be done within one and one half hours. High yield of transformants is obtained by: adding calf thymus DNA as carrier DNA; adding PEG4000, carrier DNA and plasmid DNA to cell suspension simultaneously; prolonging heat shock at 42 degrees C from 5 min to 25 min and spreading the transformation mixture directly onto agar plates after heat shock. The pretreatment of yeast intact cells with LiAc can be omitted in this procedure. The transformation rates of four types of plasmid DNA were as follows: pCN60: 3.5-7.2 x 10(4) (for linear pCN60/BamHI: 1.6 x 10(5)); YEp13: 1.7-2.6 x 10(4) (for linear YEp13/BamHI: 8.0 x 10(4)); RC4: 3.7 x 10(4); YIp5/StuI: 7.6 x 10(3). Seven recipient strains transformed by using this procedure all reached the yields of over 10(4) transformants per microgramme of DNA.
Subject(s)
Plasmids , Saccharomyces cerevisiae/genetics , Transformation, Genetic , Animals , Cattle , DNA/analysis , Genetic Techniques , TemperatureABSTRACT
TRP5, one of five genes required for tryptophan synthetase in S. cerevisiae, has been isolated on recombinant plasmids. A genomic DNA bank, containing the entire yeast genome was constructed by complete digestion of yeast 1412-4D DNA with restriction endonuclease BamH1, size fractionated by sucrose gradient (2-4 kb), and insertion of the fragments into the yeast shuttle vector pCN60. 9 recombinants plasmids capable of complementing trp5 mutations were isolated by transformation of yeast cell C9 (alpha, trp5, adel, ade6). The recombinant plasmids, containing 3.2 kb DNA fragments located TRP5 gene, were named pCN60 (TRP5). Tryptophan synthetase activity of transformants was 3-fold higher than that of original strain 1412-4D.
