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Bjørn Nicolaissen

Publications and source records attributed to Bjørn Nicolaissen.

4 recordsLinked to original sources
PubMed2006

A novel method for preserving cultured limbal epithelial cells.

AIM: To investigate organ culture preservation of cultured limbal epithelial cells in order to enhance the availability of tissue-engineered epithelia that are used to treat patients with limbal stem cell deficiency. METHODS: Limbal epithelial cells were cultured for 3 weeks on intact amniotic membrane fastened to a polyester membrane carrier. The cultured epithelia were stored for 1 week at 23 degrees C in organ culture medium. The preserved epithelia were then examined using a colorimetric cell viability assay, light microscopy and immunohistochemistry. RESULTS: The viability of the preserved epithelia was 84% (20%), and no statistically significant difference was found compared with non-preserved epithelia. In general, the cell borders were maintained, the nuclei showed no sign of degeneration, and the original layered structure was preserved. Mild intercellular oedema was occasionally observed. Expression of p63, K19 and vimentin was maintained. CONCLUSIONS: Cultured limbal epithelial cells can be preserved in organ culture medium for 1 week at room temperature, while maintaining the original layered structure and undifferentiated phenotype.

Amnion↗
PubMed2006

Donor corneas for transplantation: a scanning electron microscopic study of the epithelium.

PURPOSE: Donor corneas are processed in eye banks and used for transplantation as a standard routine. The maximum time limit post-mortem for harvesting donor tissue varies greatly between eye banks. This study aimed to examine the corneal epithelium for structural changes post-mortem. METHODS: A total of 51 corneas harvested between 14 and 163 hours post-mortem were examined using scanning electron and light microscopy. RESULTS: Cell loss occurred through desquamation of flat superficial cells during the first days. In corneas with a post-mortem time of more than 2-3 days, large superficial cell sheets and deeper cells detached, starting centrally. Deep peripheral cells remained. The loss of the superficial cells revealed the 3-dimensional structure of the epithelium and the membrane characteristics of deeper cells. CONCLUSION: The longer the time post-mortem, the greater the epithelial cell loss. However, a rim of peripheral cells remained, even after 7 days. The superficial cell layer showed signs of strong lateral attachment and broke up in a sheet-like fashion. The intercellular adhesion between deeper cells and adhesion between the basal cells and the basement membrane appeared to be weak post-mortem. The cell membrane structures of the remaining cells were surprisingly well retained. The clinical implication of the study is discussed.

Adult↗
PubMed2006

Use of amniotic membrane as an adjuvant in refractory glaucoma.

PURPOSE: To evaluate the results after amnion-shielded trabeculectomy with concomitant use of mitomycin C. METHODS: The study comprised patients with severely refractory glaucomas who had previously undergone two or more regular trabeculectomies with mitomycin C and, in one case, cyclodestructive cryotherapy. The patients were admitted for surgery between May 2003 and May 2004. Trabeculectomy was performed through a limbus-based incision in nine eyes of nine patients. Cryopreserved human amniotic membranes obtained from our biobank were impregnated with 0.4 mg/ml mitomycin C and washed for 2 mins in balanced salt solution. One membrane was sutured to the scleral surface and partly positioned under the scleral flap, and another was secured to subconjunctival tissue. RESULTS: The mean preoperative intraocular pressure (IOP) was 32.2 mmHg (range 22-44 mmHg). After a follow-up of 6-18 months (mean 9.8 months), the mean IOP was 16.4 mmHg (range 11-26 mmHg). The mean number of glaucoma medications was reduced from 2.4 preoperatively to 1.4 postoperatively. There were no devastating complications. CONCLUSIONS: Amnion-shielded trabeculectomy is a procedure that should be evaluated as an option in refractory glaucoma.

Amnion↗