Ischemia-reperfusion (IR) injury is a major cause of organ dysfunction following lung transplantation. We have recently described increased apoptosis in transplanted human lungs after graft reperfusion. However, a direct correlation between ischemic time, cell death, and posttransplant lung function has not yet been demonstrated. We hypothesized that an increased ischemic period would lead to an increase in cell death, and that the degree and type of cell death would correlate with lung function. To investigate this, we preserved rat lungs at 4 degrees C for 20 min and 6, 12, 18, and 24 h, and then transplanted the lungs and reperfused them for 2 h. Cell viability was determined with a triple staining technique combining trypan blue, terminal deoxynucleotidyl transferase-uridine nucleotide end-labeling, and propidium iodide nuclear staining. Percentages of apoptotic and necrotic cells were calculated from total cell numbers. Following 20 min and 6 and 12 h of cold preservation, less than 2% of graft cells were dead, whereas after 18 and 24 h of cold preservation, 11% and 27% of cells were dead (p < 0.05), the majority of which were necrotic. After transplantation and reperfusion, the mode of cell death changed significantly. In the 6- and 12-h groups, approximately 30% of cells were apoptotic and < 2% were necrotic, whereas in the 18- and 24-h groups, 21% and 29% of cells, respectively, were necrotic and less than 1% were apoptotic. Lung function (Pa(O(2))) decreased significantly (p < 0.05) with increasing preservation time. The percentage of necrotic cells was inversely correlated with posttransplant graft function (p < 0.0001). The study demonstrates a significant association among cold preservation time, extent and mode of cell death, and posttransplant lung function, and suggests new potential strategies to prevent and treat IR injury.
Patterns of CRC FU were widely variable despite implementation of a guideline. Despite patient and provider agreement with the principles of CRC FU, adoption was inhibited by confusion among multiple providers regarding investigation coordination.
We examined the effect of adenovirus-mediated transtracheal transfer of the human interleukin 10 (hIL-10) gene on lung ischemia-reperfusion (IR) injury, which is the insult due to hypothermic preservation plus graft reperfusion, and posttransplant lung function in Lewis rat lungs. Thirty rats were divided into 6 groups (n = 5). Groups 1 and 4 received 5 x 10(9) PFU of Ad5E1RSVhIL-10, groups 2 and 5 received 5 x 10(9) PFU of Ad5BGL2 ("empty" vector), and groups 3 and 6 received 3% sucrose (diluent). After 24 hr of in vivo transfection, lungs were stored at 4 degrees C (cold ischemic time, CIT) for 6 hr (groups 1-3) or 24 hr (groups 4-6) before transplantation. After 2 hr of reperfusion, lung function was assessed by oxygenation (FIO2, 1.0), airway pressure (AwP), and wet-to-dry (W/D) weight ratios. Rat tumor necrosis factor alpha (rTNF-alpha), interferon gamma (IFN-gamma), IL-10, and hIL-10 were measured in graft tissue and recipient plasma by ELISA and detected by immunohistochemistry (IHC). Partial pressure of oxygen (PaO2) levels in the hIL-10 group (6 hr of CIT) were higher than in empty vector and diluent groups (PaO2, 530 +/- 23 vs. 387 +/- 31 and 439 +/- 27 mmHg, respectively, p < 0.05). IL-10 rats after 24 hr of CIT showed higher PaO2 levels (260 +/- 29 mmHg) than empty vector (96 +/- 24 mmHg) or diluent (133 +/- 10 mmHg) lungs (p < 0.05). AwP and W/D ratios were reduced in hIL10 lungs (p < 0.05) compared with the other groups. rTNF-alpha and INF-gamma were reduced in tissue and plasma in groups 1 and 4 (p < 0.05). rIL-10 was reduced in the tissue of hIL-10 lungs (p < 0.05). IHC showed equal distribution of cytokines in tissue and abundant transgene expression in large and small airway epithelium in hIL-10 lungs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.