Dibutyryl cyclic adenosine monophosphate attenuates lung injury caused by cold preservation and ischemia-reperfusion

AbstractObjective: Dibutyryl adenosine 3`,5`cyclic monophosphate (db-cAMP) is a membrane-permeable analog of adenosine 3`,5`cyclic monophosphate (cAMP). We examined the effect of db-cAMP against lung injury caused by cold preservation and ischemia-reperfusion. Methods: Rats were divided into three groups (each n = 6) according to the presence or absence of db-cAMP in the preservative solution and cold ischemia (4° C for 15 hours). In the fresh group, the lung was flushed with the preservative solution and reperfusion was performed immediately. In the control group and the db-cAMP group, the lung was flushed either with the solution or with a combination of the solution plus db-cAMP, respectively, and preserved at 4° C for 15 hours. The lung was reperfused for 60 minutes in an ex vivo rat lung perfusion model. Results: The shunt ratios of the reperfused lung in the db-cAMP group were 4.0% ± 1.6% and 3.4% ± 1.2% 10 and 60 minutes, respectively, after the initiation of reperfusion, being as low as those in the fresh group and significantly lower than those in the control group (p < 0.01). The wet/dry weight ratio of the lung tissue after reperfusion was 5.99 ± 1.50 in the db-cAMP group, which was similar to that in the fresh group (5.45 ± 0.23) and significantly lower than that in the control group (14.20 ± 3.43) (p < 0.01). Electron microscopic examination showed less damage in the pulmonary arterial endothelium in the db-cAMP group. Conclusions: We conclude that db-cAMP attenuates the lung injury by cold preservation and ischemia-reperfusion, at least partly by protection of the vascular endothelium. (J Thorac Cardiovasc Surg 1997;114:635-42

Pulmonary Adenocarcinoma with Heterotopic Ossification

Pulmonary adenocarcinoma is a common malignancy that often involves calcification; however, bone formation in primary lung adenocarcinoma is extremely rare. In ten cases of primary pulmonary adenocarcinoma with heterotopic ossification, we detected immunoreactivity against TGF-β1, osteopontin, osteocalcin and Runx2 in the fibroblastic stroma and tumor cells within the area of ossification. Our results suggest that in primary pulmonary adenocarcinoma, heterotopic ossification occurs via intramembranous bone formation. To our knowledge, only 11 other cases of pulmonary adenocarcinoma with heterotopic ossification have been reported. Here, we present ten cases of pulmonary adenocarcinoma showing heterotopic ossification with a description of previously published results and the histogenesis of heterotopic bone formation

MCM2 - a promising marker for premalignant lesions of the lung: a cohort study

BACKGROUND: Because cells progressing to cancer must proliferate, marker proteins specific to proliferating cells may permit detection of premalignant lesions. Here we compared the sensitivities of a classic proliferation marker, Ki-67, with a new proliferation marker, MCM2, in 41 bronchial biopsy specimens representing normal mucosa, metaplasia, dysplasia, and carcinoma in situ. METHODS: Parallel sections were stained with antibodies against MCM2 and Ki-67, and the frequencies of staining were independently measured by two investigators. Differences were evaluated statistically using the two-sided correlated samples t-test and Wilcoxon rank sum test. RESULTS: For each of the 41 specimens, the average frequency of staining by anti-MCM2 (39%) was significantly (p < 0.001) greater than by anti-Ki-67 (16%). In metaplastic lesions anti-MCM2 frequently detected cells near the epithelial surface, while anti-Ki-67 did not. CONCLUSIONS: We conclude that MCM2 is detectable in 2-3 times more proliferating premalignant lung cells than is Ki-67. The promise of MCM2 as a sensitive marker for premalignant lung cells is enhanced by the fact that it is present in cells at the surface of metaplastic lung lesions, which are more likely to be exfoliated into sputum. Future studies will determine if use of anti-MCM2 makes possible sufficiently early detection to significantly enhance lung cancer survival rates

Ultrastructural changes of the intracellular surfactant pool in a rat model of lung transplantation-related events

<p>Abstract</p> <p>Background</p> <p>Ischemia/reperfusion (I/R) injury, involved in primary graft dysfunction following lung transplantation, leads to inactivation of intra-alveolar surfactant which facilitates injury of the blood-air barrier. The alveolar epithelial type II cells (AE2 cells) synthesize, store and secrete surfactant; thus, an intracellular surfactant pool stored in lamellar bodies (Lb) can be distinguished from the intra-alveolar surfactant pool. The aim of this study was to investigate ultrastructural alterations of the intracellular surfactant pool in a model, mimicking transplantation-related procedures including flush perfusion, cold ischemia and reperfusion combined with mechanical ventilation.</p> <p>Methods</p> <p>Using design-based stereology at the light and electron microscopic level, number, surface area and mean volume of AE2 cells as well as number, size and total volume of Lb were determined in a group subjected to transplantation-related procedures including both I/R injury and mechanical ventilation (I/R group) and a control group.</p> <p>Results</p> <p>After I/R injury, the mean number of Lb per AE2 cell was significantly reduced compared to the control group, accompanied by a significant increase in the luminal surface area per AE2 cell in the I/R group. This increase in the luminal surface area correlated with the decrease in surface area of Lb per AE2. The number-weighted mean volume of Lb in the I/R group showed a tendency to increase.</p> <p>Conclusion</p> <p>We suggest that in this animal model the reduction of the number of Lb per AE2 cell is most likely due to stimulated exocytosis of Lb into the alveolar space. The loss of Lb is partly compensated by an increased size of Lb thus maintaining total volume of Lb per AE2 cell and lung. This mechanism counteracts at least in part the inactivation of the intra-alveolar surfactant.</p

Exogenous surfactant application in a rat lung ischemia reperfusion injury model: effects on edema formation and alveolar type II cells

<p>Abstract</p> <p>Background</p> <p>Prophylactic exogenous surfactant therapy is a promising way to attenuate the ischemia and reperfusion (I/R) injury associated with lung transplantation and thereby to decrease the clinical occurrence of acute lung injury and acute respiratory distress syndrome. However, there is little information on the mode by which exogenous surfactant attenuates I/R injury of the lung. We hypothesized that exogenous surfactant may act by limiting pulmonary edema formation and by enhancing alveolar type II cell and lamellar body preservation. Therefore, we investigated the effect of exogenous surfactant therapy on the formation of pulmonary edema in different lung compartments and on the ultrastructure of the surfactant producing alveolar epithelial type II cells.</p> <p>Methods</p> <p>Rats were randomly assigned to a control, Celsior (CE) or Celsior + surfactant (CE+S) group (n = 5 each). In both Celsior groups, the lungs were flush-perfused with Celsior and subsequently exposed to 4 h of extracorporeal ischemia at 4°C and 50 min of reperfusion at 37°C. The CE+S group received an intratracheal bolus of a modified natural bovine surfactant at a dosage of 50 mg/kg body weight before flush perfusion. After reperfusion (Celsior groups) or immediately after sacrifice (Control), the lungs were fixed by vascular perfusion and processed for light and electron microscopy. Stereology was used to quantify edematous changes as well as alterations of the alveolar epithelial type II cells.</p> <p>Results</p> <p>Surfactant treatment decreased the intraalveolar edema formation (mean (coefficient of variation): CE: 160 mm³(0.61) vs. CE+S: 4 mm³(0.75); p < 0.05) and the development of atelectases (CE: 342 mm³(0.90) vs. CE+S: 0 mm³; p < 0.05) but led to a higher degree of peribronchovascular edema (CE: 89 mm³(0.39) vs. CE+S: 268 mm³(0.43); p < 0.05). Alveolar type II cells were similarly swollen in CE (423 μm³(0.10)) and CE+S (481 μm³(0.10)) compared with controls (323 μm³(0.07); p < 0.05 vs. CE and CE+S). The number of lamellar bodies was increased and the mean lamellar body volume was decreased in both CE groups compared with the control group (p < 0.05).</p> <p>Conclusion</p> <p>Intratracheal surfactant application before I/R significantly reduces the intraalveolar edema formation and development of atelectases but leads to an increased development of peribronchovascular edema. Morphological changes of alveolar type II cells due to I/R are not affected by surfactant treatment. The beneficial effects of exogenous surfactant therapy are related to the intraalveolar activity of the exogenous surfactant.</p

Impact of Normothermic Preservation with Extracellular Type Solution Containing Trehalose on Rat Kidney Grafting from a Cardiac Death Donor

BACKGROUND: The aim of this study was to investigate factors that may improve the condition of a marginal kidney preserved with a normothermic solution following cardiac death (CD) in a model of rat kidney transplantation (RTx). METHODS: Post-euthanasia, Lewis (LEW) donor rats were left for 1 h in a 23°C room. These critical kidney grafts were preserved in University of Wisconsin (UW), lactate Ringer's (LR), or extracellular-trehalose-Kyoto (ETK) solution, followed by intracellular-trehalose-Kyoto (ITK) solution at 4, 23, or 37°C for another 1 h, and finally transplanted into bilaterally nephrectomized LEW recipient rats (n = 4-6). Grafts of rats surviving to day 14 after RTx were evaluated by histopathological examination. The energy activity of these marginal rat kidneys was measured by high-performance liquid chromatography (HPLC; n = 4 per group) and fluorescence intensity assay (n = 6 per group) after preservation with UW or ETK solutions at each temperature. Finally, the transplanted kidney was assessed by an in vivo luciferase imaging system (n = 2). RESULTS: Using the 1-h normothermic preservation of post-CD kidneys, five out of six recipients in the ETK group survived until 14 days, in contrast to zero out of six in the UW group (p<0.01). Preservation with ITK rather than ETK at 23°C tended to have an inferior effect on recipient survival (p = 0.12). Energy activities of the fresh donor kidneys decreased in a temperature-dependent manner, while those of post-CD kidneys remained at the lower level. ETK was superior to UW in protecting against edema of the post-CD kidneys at the higher temperature. Luminescence intensity of successful grafts recovered within 1 h, while the intensity of grafts of deceased recipients did not change at 1 h post-reperfusion. CONCLUSIONS: Normothermic storage with extracellular-type solution containing trehalose might prevent reperfusion injury due to temperature-dependent tissue edema

Delayed mite hatching in response to mechanical stimuli simulating egg predation attempts

ダニの卵に触れると孵化が止まることを発見 --捕食者に狙われる卵がいつ孵るかの駆け引き--. 京都大学プレスリリース. 2019-09-25.Delayed or induced hatching in response to predation risk has been reported mainly in aquatic systems, where waterborne cues from predators and injured neighbouring eggs are available. Newly emerged larvae of the terrestrial predatory mite Neoseiulus womersleyi are vulnerable to predation by con- and heterospecific predatory mites, whereas their eggs are not. We examined whether N. womersleyi embryos delay hatching in response to artificial mechanical stimuli that simulates egg predation attempts. When embryos near the hatching stage were artificially stimulated every 5 min for 60 min, most stopped hatching for the duration of the 60-min period, whereas unstimulated embryos did not. Stimulated embryos resumed hatching when the treatment was stopped, and the proportion of hatched stimulated embryos caught up with that of unstimulated embryos within 120 min after stimuli stopped. Since hatching did not stop in response to changes in gravity direction, the effect of direct mechanical stimuli on the eggs was considered a proximate factor in delayed hatching. These results suggest that N. womersleyi embryos recognise immediate predation risk via mechanical stimuli, and delay hatching until the predation risk is reduced