Atherosclerosis is the major cause of ischemic stroke.Given the importance of the early diagnosis and intervention of atherosclerotic plaques,the use of molecular imaging techniques for early diagnosis of atherosclerosis has become a research focus in recent years.This article reviews the advances in research on molecular imaging in the aspect of early diagnosis of atherosclerosis.

Objective:To investigate the prognostic significance of D-dimer level in patients with diffuse large B-cell lymphoma (DLBCL).Methods:The clinical data of 70 newly diagnosed DLBCL patients who were admitted to Tianjin People's Hospital from January 2015 to June 2019 were retrospectively analyzed. The optimal cut-off value of D-dimer for survival was determined according to the receiver operating characteristic (ROC) curve, and the patients were grouped. The differences of coagulation related indexes and clinicopathological features between patients with different D-dimer levels were compared. Kaplan-Meier method was used for univariate analysis of overall survival (OS), and Cox regression model was used for multivariate analysis of OS.Results:According to ROC curve, the best cut-off value of D-dimer for survival was 0.75 mg/L. The proportion of patients with different clinical staging, international prognostic index score, lactate dehydrogenase level had statistically significant differences between the D-dimer ≥0.75 mg/L group (36 cases) and <0.75 mg/L group (34 cases) (all P < 0.05). The prothrombin time of D-dimer ≥ 0.75 mg/L group and < 0.75 mg/L group were (13.5±0.9) s and (13.0±0.8) s, respectively, and the activated partial thromboplastin time were (37±5) s and (34±6) s, respectively,and the differences were statistically significant (all P < 0.05). Univariate analysis showed that the 5-year OS rates of DLBCL patients with Ann Arbor stage Ⅲ-Ⅳ, international prognostic index score > 2, lactate dehydrogenase level > 240 U/L, B symptoms, D-dimer level ≥0.75 mg/L were decreased (all P < 0.05). Multivariate Cox regression analysis showed that D-dimer ≥0.75 mg/L was an independent risk factor for OS of DLBCL patients ( HR=0.368, 95% CI 0.144-0.944, P= 0.038). Conclusion:The level of D-dimer can be used as a clinical indicator to judge the prognosis of DLBCL patients, and the prognosis of patients with high D-dimer level is poor.

Objective: To investigate the prognostic value of prognostic nutritional index (PNI) in patients with diffuse large B-cell lym-phoma (DLBCL). Methods: We retrospectively reviewed the medical records of 82 patients with DLBCL treated at Tianjin Union Medi-cal Center between June 2010 and June 2016. The optimal cutoff value of PNI was determined using a receiver operating characteristic (ROC) curve and the Youden index. The relationship of high and low PNI with the clinical characteristics of the patients, therapeutic ef-ficacy, and prognosis were analyzed. Results: Overall, mean PNI of the patients was 46.17±8.8. When the PNI was 44.15, the Youden in-dex was found to be maximal, with a sensitivity of 74.6% and specificity of 67.2%. There were 38 patients (46.3%) in the low PNI group (<44.15) and 44 patients (53.7%) in the high PNI group (≥44.15). Data analysis showed that PNI was correlated with Eastern Coopera-tive Oncology Group performance status (ECOG PS), Ann Arbor stage, international prognostic index (IPI) score, and lactic acid dehydro-genase (LDH) level (P<0.05). The total effective rate of the low PNI group was significantly lower than that of the high PNI group (65.8% vs. 86.4%; χ2=4.848; P=0.028). The 3-year overall survival (OS) rate of the entire group of patients was 69.1%. The 1-, 2-, and 3-year OS rates of the low PNI group (86.8%, 67.8%, and 56.9%, respectively) were significantly lower than that of the high PNI group (96.7%, 89.5%, and 80.2%, respectively; χ2=9.421, P=0.002). Univariate analysis showed that PNI<44.15, ECOG PS≥2, IPI>2, stageⅢ/Ⅳ, and lymphocyte count<1.0×109/L had a significant impact on predicting OS (P<0.05). Multivariate analysis showed that PNI<44.15 (P=0.006) and stageⅢ/Ⅳ(P=0.011) were independent factors for predicting OS. Conclusions: PNI might be used as a simple and feasible clinical prognostic indicator in patients with DLBCL.

Objective: To investigate the characteristic and prognostic significance of leukemia stem cells associated antigens expressions including CD34, CD38, CD123, CD96 and TIM-3 in t (8;21) AML. Methods: Bone marrow samples of 47 t (8;21) AML patients were collected at diagnosis from October 2015 to April 2018 in Peking University Peoples’ Hospital, then flow cytometry method was performed to detect the expression frequencies of CD34, CD38, CD123, CD96 and TIM-3 to analyze the relationship between leukemia stem cells associated antigens expressions and relapse. Results: Of 47 t (8;21) AML patients tested, the median percentages of CD34⁺CD38^-, CD34⁺ CD38^-CD123⁺, CD34⁺CD38^- CD96⁺ and CD34⁺ CD38^- TIM-3⁺ cells among nucleated cells were 2.37%, 0.24%, 0.27% and 0.06%, respectively. All the frequencies of CD34⁺CD38^-, CD34⁺CD38^-CD123⁺, CD34⁺CD38^-CD96⁺ and CD34⁺ CD38^-TIM-3⁺ cells had no impact on the achievement of CR after the first course of induction. All higher frequencies of CD34⁺CD38^-, CD34⁺CD38^-CD123⁺, CD34⁺CD38^-CD96⁺ cells were related to higher 2-year CIR rate. Whereas, the frequency of CD34⁺ CD38^- TIM-3⁺ cells had no impact on CIR rate. Both high frequency of CD34⁺ CD38^- cells and the high level of minimal residual diseases (patients with <3-log reduction in the RUNX1-RUNX1T1 transcript level after the second consolidation therapy) were independent poor prognostic factors of CIR[P=0.025, HR=6.9 (95%CI 1.3-37.4) ; P=0.031, HR=11.1 (95%CI 1.2-99.2) ]. Conclusion Different leukemia stem cells associated antigens had distinct prognostic significance in t (8;21) AML. High frequencies of CD34⁺ CD38^-, CD34⁺ CD38^- CD123⁺ and CD34⁺CD38^-CD96⁺ cells at diagnosis predicted relapse in patients with t (8;21) AML.

Objective: To understand the mechanism of chemotherapy resistance in nasopharyngeal carcinoma under hypoxic conditions through the perspective of protein SUMOylation modification. Methods: Cobalt chloride (CoCl₂) was used to establish the hypoxic model of human nasopharyngeal carcinoma CNE1 cells. Then, the cell cycle was detected by flow cytometry, and the expression level of small ubiquitin-related modifier(SUMO) and cyclin-dependent kinase 6 (CDK6) proteins were detected by western blotting. MTT assay was used to determine the median lethal dose (IC₅₀) of cancer cells against cisplatin, and enzyme-linked immunosorbent assay (ELISA) was used to determine lactate dehydrogenase (LDH) level. Results: The cell cycle of CNE1 induced by hypoxia was arrested in G0/G1 phase.The results of Western blot showed that the protein expression level of CDK6 in CNE1 cells was lower than that in the control group (0.83±0.25 vs. 0.43±0.21, t=14.67, P=0.003). The protein level of conjugated SUMO1 was significantly lower than that in the control group (2.69±0.48 vs. 1.38±0.31, t=17.22, P=0.001), while the level of free SUMO1 protein was significantly higher than that in the control group (2.01±0.43 vs. 2.60±0.59, t=15.45, P=0.002).The LC50 of CNE1 cells in the control group was significantly lower than that in the hypoxic group (29.44 μg/ml vs. 97.72 μg/ml, t=12.79, P=0.001). After CNE1 cells received 50 μg/ml cisplatin for 48 h, the LDH content in the supernatant of the control group was significantly higher than that in the hypoxic group ((541.49±64.59) ng/ml vs. (234.67±41.03) ng/ml, t=11.94, P=0.007)). The apoptosis rate of CNE1 cells in the control group was significantly higher than that in the hypoxic group ((76.64±5.37)% vs. (32.84±4.77) ng/ml, t=8.49, P=0.003)). Conclusion Hypoxia can dissociate the covalent modification of CDK6 and SUMO1, inhibit cell cycle and increase the chemotherapy resistance of nasopharyngeal carcinoma.

【Objective】 To investigate the clinical features and gene analysis of one pedigree with multiple endocrine neoplasia type 2A （MEN2A） so as to clarify the diagnosis and classification of the disease， guide treatment and prevention， and improve prognosis. 【Methods】 The clinical data of a 36-member MEN2A family， including 6 probands， with medullary thyroid carcinoma， were investigated， and the peripheral blood genomic DNA of 28 family members （blood sample of one proband was not collected） was extracted. PCR amplification was performed on exons 8， 10， 11， 13， 14， 15 and 16 of the RET gene， and the products were directly sequenced. 【Results】 Review of the medical history showed that two probands with medullary thyroid carcinoma were accompanied with hyperparathyroidism， and one family member had pheochromocytoma. The RET gene mutation test confirmed that 13 family members， consisting of 5 probands and 8 family members， had the RET proto-oncogene exon 10 missense mutation. The heterozygous missense had mutation c.1852T>A， leading to the conversion of cysteine （TGC） at position 618 to serine （AGC） （Cys618Ser）. All subjects carrying RET gene Cys618Ser mutation had abnormal thyroid ultrasound change， accompanied with elevated calcitonin levels. Subjects carrying wild type of RET gene had normal calcitonin levels. The family was finally diagnosed with MEN2A by RET gene detection. 【Conclusion】 RET gene detection plays key role in the diagnosis and treatment of patients with MEN2A family and has guiding value in the follow-up and prognosis of asymptomatic carriers. There is a positive correlation between calcitonin level and the RET protooncogene mutation Cys618Ser. Patients suspected of MEN2A should be screened in time.