Publications

The retinal pigment epithelium (RPE) plays an important role in maintaining a healthy neural retina. With changes due to age, morbidity or removal of choroidal neovascularis developed as a means ofation, damage or defects of the RPE occur. Accordingly, RPE transplantation techniques have been repairing the damaged RPE. We conducted a study to transplant tissue-engineered RPE cell sheets in a rabbit model. RPE cells were isolated from pigmented rabbit eyes and seeded on temperature-responsive culture surfaces. Cultured RPE cells were arranged as a monolayer with a cobblestone cell shape that is characteristic of native RPE. The pigmented RPE cell sheets were non-invasively harvested without enzymatic treatment simply by reducing the culture temperature. Using 3-port vitrectomy, RPE cell sheets were transplanted into the subretinal space of albino rabbits. Seven days after surgery, the rabbits were sacrificed, and the eyes were enucleated and examined under both light and electron microscopy. After transplantation, our results show that the RPE cell sheets attached to the host tissues in the subretinal space more effectively than with the injection of isolated cell suspensions. Although the cell sheets maintained a monolayer structure in most areas, they were slightly folded or wrinkled in some regions. We conclude that tissue-engineered RPE cell sheets harvested from temperature-responsive culture dishes can be effectively transplanted beneath the neural retina.

OBJECTIVE

The objective of the study was to examine the relationship between bilateral oophorectomy (BSO) and risk of coronary heart disease (CHD).

STUDY DESIGN

We searched PubMed, EMBASE, meeting abstracts, and reference lists for studies that compared women with BSO at the time of hysterectomy with: (1) women with hysterectomy and ovarian conservation, (2) naturally menopausal women, (3) premenopausal women, or (4) women with no history of hysterectomy or BSO but unreported menopausal status. The primary outcome was fatal or nonfatal CHD.

RESULTS

We reviewed 1956 citations. Seven observational studies met inclusion criteria. Heterogeneity among studies precluded formal metaanalysis. Four studies reported BSO increases risk for CHD but only in some subgroups of women or not in fully adjusted multivariate models. Three studies found no increased risk of CHD following BSO, but these studies had significant limitations.

CONCLUSION

The existing evidence is inconclusive to determine the effect of BSO on risk of CHD.

Activation of sphingosine kinase/sphingosine-1-phosphate (SK/S1P)-mediated signalling has been recognized as critical for cardioprotection in response to acute ischaemia/reperfusion injury. Incubation of S1P with cultured cardiac myocytes subjected to hypoxia or treatment of isolated hearts either before ischaemia or at the onset of reperfusion (pharmacologic pre- or postconditioning) results in reduced myocyte injury. Synthetic agonists active at S1P receptors mimic these responses. Gene-targeted mice null for the SK1 isoform whose hearts are subjected to ischaemia/reperfusion injury exhibit increased infarct size and respond poorly either to ischaemic pre- or postconditioning. Measurements of cardiac SK activity and S1P parallel these observations. Ischaemic postconditioning combined with sphingosine and S1P rescues the heart from prolonged ischaemia. These observations may have considerable relevance for future therapeutic approaches to acute and chronic myocardial injury.

BACKGROUND

Although alveolar epithelial injury is a major determinant of outcome in patients with acute lung injury, there is no reliable biological marker of alveolar epithelial injury. The primary objective was to determine whether elevated levels of the receptor for advanced glycation end products (RAGE), a marker of alveolar epithelial injury, reflect impaired alveolar fluid clearance (AFC) in an ex vivo perfused human lung preparation. A second objective was to determine whether levels of a marker of endothelial injury, von Willebrand factor antigen (vWF:Ag), are associated with impaired AFC.

METHODS

Human lungs (N = 30) declined for transplantation by the California Transplant Donor Network were perfused at a constant pulmonary artery pressure of 12 mm Hg. Following rewarming to 36 degrees C, the lungs were inflated with a continuous positive airway pressure of 10 cm H(2)O. RAGE and vWF:Ag levels and AFC rates were then measured.

RESULTS

The rate of AFC was inversely correlated with RAGE levels in the alveolar fluid (p < 0.005). Similarly, the concentration of RAGE in the alveolar fluid was significantly higher in lungs with submaximal AFC, defined in a prespecified analysis as

CONCLUSIONS

RAGE may be a useful biological marker of alveolar epithelial injury and impaired AFC in donor lungs prior to transplant and perhaps in patients with acute lung injury.