Bacterial contamination of amniotic membrane in a tissue bank from Iran

All surgical operations have the potential for contamination, and the equipment used can harbour bacteria. We collected samples from 100 elective primary hip and knee arthroplasties. These showed rates of contamination of 11.4% for the sucker tips, 14.5% for light handles, 9.4% for skin blades and 3.2% for the inside blades used during surgery; 28.7% of gloves used for preparation were also contaminated. Of the samples taken from the collection bags used during hip arthroplasty, 20% grew bacteria, which represents a significant microbial reservoir. Also, 17% of theatre gowns were contaminated at the end of the operation. Contamination was found in 10% of the needles used during closure of the fascia. Overall, 76% of the organisms grown were coagulase-negative staphylococcus. A total of 63% of operations showed contamination in the field of operation. Some changes in practice are suggested. Follow-up for a minimum of two years revealed one deep infection but the organism was not identified as a contaminant. These data provide a baseline for studying the bacteriology of the surgery of revision arthroplasty.

Human amniotic membrane isolated from the placenta contained basement membrane components such as type IV collagen, laminin, and 6 and 4 integrins, all of which remained detectable while preserved in glycerin for one week. One month after the n-heptanol removal of the total corneal epithelium and the limbal lamellar keratectomy, all rabbit eyes carried features of limbal deficiency, including conjunctival epithelial ingrowth, vascularization and chronic inflammation. Ten control eyes then received a total keratectomy, and 13 experimental eyes received an additional amniotic membrane transplantation. Three-month follow-ups revealed that all control corneas were revascularized to the center with granuloma and retained a conjunctival phenotype. In contrast, in the experimental groups, 5 corneas became clear with either minimal or no vascularization; the rest had either mild peripheral (5) or total (3) vascularization and more cloudy stroma. Using monoclonal antibodies for epithelial markers and matrix components, we concluded that the success correlated with the return of a cornea-like epithelial phenotype and the preservation of the amniotic membrane, whereas the failure maintained a conjunctival epithelial phenotype and the amniotic membrane was either partially degraded or covered by host fibrovascular stroma. Measures taken to facilitate the former might prove this procedure clinically useful for ocular surface reconstruction.