[Covered airway stent loaded with (125)I seeds for tracheal adenoid cystic carcinoma: a clinical observation of 8 cases].

Objective: To explore the efficacy and safety of the covered airway stent loaded with (125)I seeds for the treatment of tracheal adenoid cystic carcinoma (TACC). Methods: We retrospectively reviewed the clinical data from 8 patients with TACC who had received placement of the covered stent loaded with (125)I seeds between December 2014 and July 2017 in the endoscopic center of the Second Affiliated Hospital of Xiamen Medical College. We compared the difference in the dyspnea index, the diameter of the airway lumen, and the lesion surrounding the airway wall before and after treatment. The complications were also recorded during follow-up. Results: Eight patients underwent successful placement of a total of 11 radioactive stents (2 straight-type stents, 2 L-shape stents, and 7 Y-shape stents, all loaded a total of 243 radioactive particles). Displacement of stents took place within 2 weeks in 2 patients, who were managed with re-stenting and fixation. No further displacement occurred during follow-up. The median time to stent removal was 2.9(interquartile range: 2.3,3.0) months. After stent placement, the dyspnea index was significantly decreased compared with pre-treatment level (mean: 0.1 vs. 3.4, t=8.881, P<0.001). Bronchoscopic re-assessment showed that the residual tumor within the airway was detected in only one patient and that the tumor completely disappeared in the remaining 7 patients. Treatment with stents loaded with radioactive particles yielded smooth and pale airway mucosa with formation of partial scar formation. Chest computed tomography re-assessment demonstrated significantly larger luminal diameter than that before treatment (mean: 13.1 mm vs. 3.3 mm, t=-7.839, P<0.001). The airway wall thickness was notably reduced after treatment (mean: 4.3 mm vs. 14.4 mm, t=7.620, P<0.001). The lesions surrounding the airway wall completely disappeared in 7 patients and decreased for more than 50% in a single patient. The median duration of follow-up was 28.0(interquartile range: 24.8,31.5) months. Recurrence of tumor was documented in a single case within 2 years. Six patients did not experience recurrence within the 2-year follow-up period. No death or severe complications were recorded during follow-up. Conclusion: The (125)I radioactive stent is effective for dilating the stenotic airway and ameliorating the symptoms, and thus might be an effective and safe method for the treatment of TACC. Further studies that explore the efficacy of stents loaded with (125)I particles are needed.

Upregulation of miR-27a contributes to the malignant transformation of human bronchial epithelial cells induced by SV40 small T antigen.

The introduction of the Simian virus 40 (SV40) early region, the telomerase catalytic subunit (hTERT) and an oncogenic allele of H-Ras directly transforms primary human cells. SV40 small T antigen (ST), which forms a complex with protein phosphatase 2A (PP2A) and inhibits PP2A activity, is believed to have a critical role in the malignant transformation of human cells. Recent evidence has shown that aberrant microRNA (miRNA) expression patterns are correlated with cancer development. Here, we identified miR-27a as a differentially expressed miRNA in SV40 ST-expressing cells. miR-27a is upregulated in SV40 ST-transformed human bronchial epithelial cells (HBERST). Suppression of miR-27a expression in HBERST cells or lung cancer cell lines (NCI-H226 and SK-MES-1) that exhibited high levels of miR-27a expression lead to cell growth arrested in the G(0)-G(1) phase. In addition, suppression of miR-27a in HBERST cells attenuated the capacity of such cells to grow in an anchorage-independent manner. We also found that suppression of the PP2A B56γ expression resulted in upregulation of miR-27a similar to that achieved by the introduction of ST, indicating that dysregulation of miR-27a expression in ST-expressing cells was mediated by the ST-PP2A interaction. Moreover, we discovered that Fbxw7 gene encoding F-box/WD repeat-containing protein 7 was a potential miR-27a target validated by dual-luciferase reporter system analysis. The inverse correlation between miR-27a expression levels and Fbxw7 protein expression was further confirmed in both cell models and human tumor samples. Fbxw7 regulates cell-cycle progression through the ubiquitin-dependent proteolysis of a set of substrates, including c-Myc, c-Jun, cyclin E1 and Notch 1. Thus, promotion of cell growth arising from the suppression of Fbxw7 by miR-27a overexpression might be responsible for the viral oncoprotein ST-induced malignant transformation. These observations demonstrate that miR-27a functions as an oncogene in human tumorigenesis.

α4 is highly expressed in carcinogen-transformed human cells and primary human cancers.

A regulator of the protein phosphatase 2A (PP2A), α4, has been implicated in a variety of functions that regulate many cellular processes. To explore the role of α4 in human cell transformation and tumorigenesis, we show that α4 is highly expressed in human cells transformed by chemical carcinogens including benzo(a)pyrene, aflatoxin B(1), N-methyl-N'-nitro-N-nitrosoguanidine, nickel sulfate and in several hepatic and lung cancer cell lines. In addition, overexpression of α4 was detected in 87.5% (74/80) of primary hepatocellular carcinomas, 84.0% (21/25) of primary lung cancers and 81.8% (9/11) of primary breast cancers, indicating that α4 is ubiquitously highly expressed in human cancer. Functional studies revealed that elevated α4 expression results in an increase in cell proliferation, promotion of cell survival and decreased PP2A-attributable activity. Importantly, ectopic expression of α4 permits non-transformed human embryonic kidney cells (HEKTER) and L02R cells to form tumors in immunodeficient mice. Furthermore, we show that the highly expressed α4 in transformed cells or human tumors is not regulated by DNA hypomethylation. A microRNA, miR-34b, that suppresses the expression of α4 through specific binding to the 3'-untranslated region of α4 is downregulated in transformed or human lung tumors. Taken together, these observations identify that α4 possesses an oncogenic function. Reduction of PP2A activity due to an enhanced α4-PP2A interaction contributes directly to chemical carcinogen-induced tumorigenesis.

A submerged tubular ceramic membrane bioreactor for high strength wastewater treatment.

A 4 L submerged tubular ceramic membrane bioreactor (MBR) was applied in laboratory scale to treat 2,400 mg-COD/L high strength wastewater. A prolonged sludge retention time (SRT) of 200 day, in contrast to the conventional SRT of 5 to 15 days, was explored in this study, aiming to reduce substantially the amount of disposed sludge. The MBR system was operated for a period of 142 days in four runs, differentiated by specific oxygen utilization rate (SOUR) and hydraulic retention time (HRT). It was found that the MBR system produced more than 99% of suspended solid reduction. Mixed liquor suspended solids (MLSS) was found to be adversely proportional to HRT, and in general higher than the value from a conventional wastewater treatment plant. A chemical oxygen demand (COD) removal efficiency was achieved as high as 98% in Run 1, when SOUR was in the range of 100-200 mg-O/g-MLVSS/hr. Unexpectedly, the COD removal efficiency in Run 2 to 4 was higher than 92%, on average, where higher HRT and abnormally low SOUR of 20-30 mg-O/g-MLVSS/hr prevailed. It was noted that the ceramic membrane presented a significant soluble nutrient rejection when the microbial metabolism of biological treatment broke down.

[Histopathological observation of experimental slight viral myocarditis].

To study the diagnostic method of slight viral myocarditis in the field of forensic pathology, slight viral myocarditis model was induced in Balb/c murine by coxsackie virus B3. Organs of hearts, livers, spleens, lungs and kidneys were examined through routine pathological methods. Pathological changes at different levels of these organs were observed. The results indicated that viral myocarditis was a kind of disease with multiple organ alterations and that the pathological observation and comprehensive analysis of multiple organs was one of the useful methods for diagnosing slight viral myocarditis.

[Study on the specificity of complement C5 for the postmortem diagnosis of myocardial infarction].

In order to explore the specificity of complement C5 in the postmortem diagnosis of myocardial infarction, changes of C5 staining in normal, infarcted and other non-infarcted myocardia with direct or indirect myocardial injuries (myocarditis, mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion and organophosphate poisoning) were studied with immunohistochemistry and image analysis. The results showed that positive C5 staining could be observed in groups of myocardial infarction and myocarditis, but not in groups of mechanical asphyxia, electrocution, hemorrhagic shock, cardiac contusion, and organophosphate poisoning. It is indicated that positive reaction of C5 could only be affected by myocarditis, which means that it was more specific for the diagnosis of myocardial infarction.

[Evaluation of anti-muscle actin monoclonal antibody HHF35 in the diagnosis of early myocardial infarction].

In order to explore the specificity of anti-muscle actin monoclonal antibody HHF35 in the postmortem diagnosis of early myocardial infarction, the changes of HHF35 staining in the infarcted myocardia and other non-infarcted myocardia with direct or indirect myocardial injury were studied with immunohistochemical S-P method. The results showed that the loss of HHF35 staining of different degrees was found in the infarcted myocardia, but also in the other non-infarcted myocardia with direct or indirect myocardial injury, such as cardiac contusion, myocarditis, hemorrhagic shock, electrocution, mechanical asphyxia. So it should be cautious in diagnosing early myocardial infarction with HHF35 immunohistochemistry.