The basical structure of diketopiperazines is a cyclic dipeptide condensed by two amino acids. Because of the stable framework of the six-member ring structure, and having two hydrogen bond donor and two hydrogen bond receptor, DKPs have become important chemical pharmacophores, with strong biological activities and pharmacological activities in the drug. A series of cyclic compounds were found from marine organisms in recent years, research showed that their functions are not limited on anti-bacterial, cytotoxic activity, and so on, but also playing an important role in regulatory mechanism of quorum sensing as signal molecules, they have become research hot point in ecological chemistry. This paper reviewed the research progress of diketopiperazines found in the marine microbial metabolites, and the future study trends was discussed and outlooked.

Lung cancer (LC) is the most common cancer and the leading cause of cancer-related death worldwide. The 5-year survival rate for LC remains low at 18% and is 5% for patients with metastatic disease, while the 5-year overall survival rate of patients with stage I NSCLC can reach 77.9%, hence early diagnosis and treatment of LC is the key to improve the prognosis. As a non-invasive detection technique, Raman spectroscopy can realize the non-destructive detection of the differences in molecular level structure between cancerous tissues and normal tissues, which can be used for the early diagnosis of lung cancer. The aim of this review is to summarize the progress of Raman spectroscopycombined with different tissue or body fluid samplesin the diagnosis of early LC.
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Early Detection of Cancer ; methods ; Humans ; Lung Neoplasms ; diagnosis ; Spectrum Analysis, Raman ; methods

Objective: To investigate the value of the folate receptor (FR)-positive circulating tumor cell (CTC) detection in the diagnosis of benign and malignant subcentimeter pulmonary nodules(the maximum diameter ≤10 mm). Methods: Thirty-seven patients with subcentimeter pulmonary nodules (the chest CT showed the maximum diameter was ≤10 mm) in the Xuanwu Hospital of Capital Medical University from July to December 2018 were collected. Among them, 22 cases were diagnosed with early stage lung adenocarcinoma by postoperative pathological diagnosis and another 15 cases were benign lung lesion. Venous blood samples from these patients were collected before surgery and then utilized to detect FR⁺ CTC level (defined unit as FU/3 ml) by novel ligand-targeted polymerase chain reaction (LT-PCR), and the enzyme-linked immunosorbent assay was used to detect the levels of tumor markers, including carcinoembryonic antigen (CEA), neuron-specific enolase(NSE), cytokeratin 19 fragment CYFRA21-1, carbohydrate antigen 125 (CA125), CA199, pro-gastrin releasing peptide (pro-GRP), etc. The t-test was used to compare the measurement values between the groups. The CTC value 8.70 FU/3 ml described in the detection kit instruction was used as the threshold. The binary logistic regression was used to analyze the risk factors of malignant pulmonary nodules. The kappa consistency test was used to identify the consistency of the diagnosis results obtained by the FR⁺ CTC level and the pathological results of surgically resected specimens. The receiver operating characteristic curve (ROC) was drawn to evaluate the efficiency of each index for the diagnosis of benign and malignant subcentimeter pulmonary nodules. Results: The level of FR⁺ CTC in patients with early stage lung cancer was higher than that in patients with benign lung lesion, and the difference was statistically significant [(11.0±3.0) FU/3 ml vs. (7.0±3.7) FU/3 ml, t=-3.327, P = 0.001]. The level of FR⁺ CTC was not related to the age, gender and smoking history of patients (all P>0.05). Logistic regression analysis indicated that high-level FR⁺ CTC was one of the risk factors for malignant pulmonary nodules (OR = 37.333, 95% CI 3.994-349.010, P = 0.002). The kappa consistency test indicated that the level of FR⁺ CTC used for the diagnosis of lung subcentimeter nodules presented a certain accuracy (κ = 0.627, P < 0.01). ROC illustrated that the FR⁺ CTC was better than CEA, NSE and CYFRA21-1 when it was used as an indicator for the diagnosis of malignant pulmonary nodules. The area under the curve(AUC) of FR⁺ CTC was 0.830 (95% CI 0.639-0.968), and the diagnostic sensitivity and specificity were 72.7% (95% CI 49.6%-88.4%) and 93.3% (95% CI 66.0%-99.7%), respectively. When FR⁺ CTC, CEA, NSE and CYFRA21-1 were combined for lung cancer diagnosis, the AUC, sensitivity and specificity were 0.776 (95% CI 0.614-0.938), 86.4% and 73.3%, respectively. Conclusion The detection of FR⁺ CTC has a high value in the diagnosis of benign and malignant subcentimeter pulmonary nodules.

Objective    To evaluate the learning curve of CT-guided medical glue localization for pulmonary nodule before video-assisted thoracic surgery (VATS). Methods    The clinical data of the patients with pulmonary nodules who underwent CT-guided medical glue localization before VATS in our hospital from July 2018 to March 2021 were retrospectively analyzed. The patients were divided into 3 groups: a group A (from July 2018 to August 2019), a group B (from September 2019 to June 2020) and a group C (from July 2020 to March 2021). The localization time, morbidity, complete resection rate and other indexes were compared among the three groups. Results    A total of 77 patients were enrolled, including 24 males and 53 females aged 57.4±10.1 years. There were 25 patients in the group A, 21 patients in the group B, and 31 patients in the group C. 77 pulmonary nodules were localized. There was no significant difference among the groups in the basic data (P>0.05). The localization time in the group C was 10.6±2.0 min, which was statistically shorter than that in the group A (15.4±4.4 min) and group B (12.9±4.3 min) (P<0.01). The incidence of complications in the group C was lower than that in the group A and group B (25.8% vs. 52.0% vs. 47.6%, P=0.04). The success rate of localization of the three groups was not statistically different (P=0.12). Conclusion    There is a learning curve in CT-guided medical glue localization for single pulmonary nodule before VATS. After the first 46 cases, the operation time can be shortened, and the incidence of complications can be decreased.

Objective     To assess the long-term results and relevant influencing factors of extended thymectomy and medicine-alone treatment of non-thymomatous myasthenia gravis (MG) patients. Methods     We retrospectively analyzed the clinical data of 174 patients with non-thymomatous MG diagnosed and treated in our department from December 2009 to April 2017, including 81 males and 93 females, aged 13-88 (47.1±17.8) years. According to the different treatment methods, the patients were divided into two groups: an operation group (91 patients receiving extended thymectomy) and a medicine-alone group (83 patients receiving medical therapy alone). The efficacy was evaluated according to the Myasthenia Gravis Foundation of America (MGFA). Survival curves of the patients were plotted using the Kaplan-Meier method to evaluate the remission rate and survival rate. Cox regression analysis was used to assess the influencing factors of the outcomes. Results     The patients were followed up for 3 to 94 (39.1±26.9) months. As a result, 29 patients (31.9%) achieved complete remission in the surgery group and 13 patients (15.7%) were completely relieved in the medicine-alone group (P=0.014). Further analysis showed that treatment pattern (P=0.018) and MG type (P=0.021) were the main factors related to the efficacy. Conclusion     For patients with non-thymomatous MG, extended thymectomy is superior to the medicine-alone in terms of complete remission rate and the postoperative immunosuppression ratio.