ABSTRACT
Lung transplantation has become the most effective treatment of end-stage lung diseases. Along with persistent optimization of lung transplantation technique and perioperative management, the short-term clinical efficacy after lung transplantation has been significantly improved, whereas the long-term clinical prognosis remains unoptimistic. Besides chronic lung allograft dysfunction, postoperative malignant tumors also threaten the long-term survival of the recipients. Common malignant tumors following lung transplantation include nonmelanoma skin cancer, posttransplant lymphoproliferative disease and lung cancer. After solid organ transplantation, a large majority of the recipients require lifelong immunosuppressive therapy. The intensity of immunosuppressive therapy for the lung transplant recipients is generally higher than other organ transplant recipients. Immunosuppression is the main factor which leads to the impairment of anti-tumor immune monitoring function and promotes the incidence and development of malignant tumors. In this article, the risk factors, prevention and treatment of the most common malignant tumors after lung transplantation were reviewed, aiming to provide reference for comprehensive diagnosis and treatment of malignant tumors following lung transplantation.
ABSTRACT
Lung transplantation is the only effective treatment of end-stage lung diseases. Nevertheless, shortage of donor lungs has become increasingly prominent worldwide. A large quantity of patients died while waiting for lung transplantation. Urgent lung transplantation is a prioritized allocation strategy for donor lung transplantation according to the urgency of diseases, aiming to shorten the waiting time for donor lungs and reduce the fatality of patients on the waiting list for lung transplantation. However, no consensus has been reached worldwide on the definition, criteria and application of the terminology of urgent lung transplantation. In addition, the survival and net benefits of lung transplant recipients based on this allocation system are still controversial. On the basis of previous clinical research on urgent lung transplantation, the definition criteria, risk factors, survival outcomes, limitations and optimization measures were explicitly elucidated in this article, aiming to provide theoretical reference for comprehensive evaluation of the feasibility of urgent lung transplantation and further optimizing the allocation system of donor lungs.
ABSTRACT
@#PEGylated uricase was prepared with the N-terminal amino site-specific modification by periodate oxidation followed by reductive-amination. A monomethoxy poly(ethylene glycol)intermediate was synthesized by amidation from monomethoxy poly(ethylene glycol)amine hydrochloride 20000(mPEG20000-NH2 ·HCl)with the relative molecular mass of 20 kD and N-(tert-butoxycarbonyl)-L-serine(Boc-Ser-OH), and then the Boc group of the intermediate was removed by trifluoroacetic acid(TFA)to produce the desired product Ser-mPEG20000. This compound could be oxidated by periodate to obtain a new poly(ethylene glycol)aldehyde derivative with high activity, which could be used to modify proteins with the N-terminal amino site-specific PEGylation after ultrafiltration, and the modification conditions to uricase by Ser-mPEG20000 were optimized. The structures of poly(ethylene glycol)intermediate and the target product were characterized by IR and 1H NMR, and the overall yield of the target product was 72. 8%. The preliminary modification to uricase indicated that the desired product Ser-mPEG20000 could modify proteins easily and efficiently. The optimal modification conditions of uricase PEGylated by Ser-mPEG20000 were obtained as follows: the molar ratio of Ser-mPEG20000 to uricase was 2 ∶1; the pH value of solution was 5. 0; the reaction temperature was 25 °C and the reaction time was 6 h.