Multi-parametric evaluation of autologous cultivated Limbal epithelial cell transplantation outcomes of Limbal stem cell deficiency due to chemical burn.

BACKGROUND: The sparsity of established tools for the grading of limbal stem cell deficiency hinder objective assessments of the clinical outcome of cultivated limbal epithelial cell transplantation. To advance towards the development of standards for the comparison of the outcomes of these bio-surgical protocols we have now applied a battery of recognized objective and patient-declared subjective outcome criteria to the autologous modality of cultivated limbal epithelial cell transplantation. METHODS: The prospective study involved ten patients (M/F = 9/1; mean age = 42.1 years) displaying overt unilateral limbal stem cell deficiency complying with the inclusion criteria described in Methods. Limbal biopsies were obtained from the contralateral eye and their outgrowths after 2-week cultures were transplanted on the affected eye after pannus resection. Outcomes were followed up for 12 months. The objective tests were scores for best-corrected visual acuity (BCVA); using the LogMAR scale, a multiparametric ocular surface score (OSS), and the Schirmer's test. Subjective scores were based on patient answers to a) perception of visual improvement/pain; b) the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25); and c) the 12-item Ocular Surface Disease Index Questionnaire (OSDI). All procedures were performed under good manufacture practices using solely xeno-free reagents. In all cases, a single biopsy was divided into two pieces and they were expanded in order to prevent outgrowth failure. In 5 patients, both biopsies generated healthy culture sheet. In those cases the lesser outgrowth were used for immune-histological characterization. RESULTS: The experimental parallel outgrowth samples showed a similar percent of p63α+ cells. PreOp and 12-month PostOp BCVAs and OSSs were, respectively, 1.15 ± 0.70; 0.21 ± 0.13 and 7.40 ± 2.01; 2,30 ± 1.30, (p < 0.05). Patient's responses to all three question sets except ocular pain were consistent with significant improvement (p < 0.05). CONCLUSION: Objective clinical metrics demonstrate that in patients with limbal stem cell deficiency, cultivated limbal epithelial cell transplantation improves vision and ocular surface health and subjective visual perceptions.

The protective effect of Gingko biloba in a rat model of ovarian ischemia/reperfusion injury: Improvement in histological and biochemical parameters.

BACKGROUND: Ovarian torsion is one of the most common gynecological emergencies, which especially affects women of reproductive age. OBJECTIVES: We aimed to evaluate the effect of Ginkgo biloba (GB) supplementation in ovarian ischemia/ reperfusion injury in an experimental torsion/de-torsion rat model. MATERIAL AND METHODS: This study was carried out in the Ege University Faculty of Medicine in Izmir, Turkey. Thirty mature female Sprague-Dawley albino rats were randomly divided into 5 groups: in Group 1 (control), the abdominal wall was only opened and closed; in the torsion group (Group 2), ischemia was induced for 3 h, using atraumatic vascular clips to create a torsion model; in the torsion/GB group (Group 3), the rats were given 80 mg/kg (oral gavage) of GB 30 min before torsion was induced and the torsion model was formed; in the torsion/de-torsion group (Group 4), the rats underwent 3 h of ischemia and then the vascular clips were removed and reperfusion took place for 3 h; in the torsion/de-torsion/GB group (Group 5), the rats underwent 3 h of ischemia followed by GB (oral gavage) 30 min prior to a 3-h reperfusion period. Ovarian tissue damage was evaluated by a histopathological scoring system. Ovarian tissue malondialdehyde (MDA) and plasma pentraxin-3 were measured. RESULTS: In comparison with the sham group, both the torsion and torsion/de-torsion groups had significantly higher scores for follicular degeneration, vascular congestion, edema, hemorrhage, and leukocyte infiltration. Ginkgo biloba significantly decreased these scores in both groups. Ovarian malondialdehyde and plasma pentraxin 3 were significantly higher both in the torsion and torsion/de-torsion groups compared with the sham group. Ginkgo biloba decreased these levels significantly both in the torsion/GB and torsion/de-torsion/GB groups. CONCLUSIONS: Supplementing GB during a surgical procedure decreases ischemia/reperfusion injury to an ovary in an experimental rat model based on histopathological parameters, tissue malondialdehyde, and plasma pentraxin-3 levels.

Limbal Stem Cell Deficiency and Treatment with Stem Cell Transplantation.

The cornea is the outermost tissue of the eye and it must be transparent for the maintenance of good visual function. The superficial epithelium of the cornea, which is renewed continuously by corneal stem cells, plays a critical role in the permanence of this transparency. These stem cells are localized at the cornea-conjunctival transition zone, referred to as the limbus. When this zone is affected/destroyed, limbal stem cell deficiency ensues. Loss of limbal stem cell function allows colonization of the corneal surface by conjunctival epithelium. Over 6 million people worldwide are affected by corneal blindness, and limbal stem cell deficiency is one of the main causes. Fortunately, it is becoming possible to recover vision by autologous transplantation of limbal cells obtained from the contralateral eye in unilateral cases. Due to the potential risks to the donor eye, only a small amount of tissue can be obtained, in which only 1-2% of the limbal epithelial cells are actually limbal stem cells. Vigorous attempts are being made to expand limbal stem cells in culture to preserve or even enrich the stem cell population. Ex vivo expanded limbal stem cell treatment in limbal stem cell deficiency was first reported in 1997. In the 20 years since, various protocols have been developed for the cultivation of limbal epithelial cells. It is still not clear which method promotes effective stem cell viability and this remains a subject of ongoing research. The most preferred technique for limbal cell culture is the explant culture model. In this approach, a small donor eye limbal biopsy is placed as an explant onto a biocompatible substrate (preferably human amniotic membrane) for expansion. The outgrowth (cultivated limbal epithelial cells) is then surgically transferred to the recipient eye. Due to changing regulations concerning cell-based therapy, the implementation of cultivated limbal epithelial transplantation in accordance with Good Laboratory Practice using xenobiotic-free systems is becoming widely accepted both in Turkey and worldwide.