Stable isotope coded derivatization (ICD) is an isotope labeling technique for specific functional groups of the target analytes through chemical derivatization.ICD combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) enables systematically analyzing the biomolecules with the same labeling reaction characteristic.ICD technique can effectively solve the limited sensitivity in complex bio-matrices analysis and unavailability of isotope internal standards in quantitative analysis.In recent years, ICD technique has been widely used in metabolomics research field.Based on this background, the ICD technique and the design of ICD reagents are briefly described in this review.The recent advances in ICD reagents for carboxyl, amino, carbonyl, thiol and hydroxyl groups and their applications in the analysis of small molecule metabolites in bio-matrices with LC-MS/MS are reviewed.

Objectives To screen the high-risk population of stroke in China using color Doppler flow imaging (CDFI)and to establish a stroke risk prediction model in Chinese population in order to prevent and treat stroke early. Methods Forty-one base hospitals and 715 286 people in the project areas of the first 6 provinces of China conducted routine physical examinations and investigated the related risk factors for cardiocerebrovascular diseases from July 2011 to April 2012 using a cross-sectional study,among them 61 860 patients underwent carotid CDFI screening,and 49 386 of them were high-risk population (exposed to≥3 risk factors). The bilateral common carotid interma-media thickness (IMT),the number of plaques and the degree of carotid stenosis were screened and documented. And whether carotid IMT thickening or not,with or without carotid plaques,and degree of carotid artery stenotic rate 0-49% and≥50% were performed by multivariate logistic regression analysis with the risk factors for stroke,respectively. Results (1)Logistic regression analysis showed that hypertension,atrial fibrillation,smoking,and lack of physical exercise were the independent risk factors for carotid IMT thickening (hypertension:OR,1. 17;95%CI 1. 12-1. 22;atrial fibrillation:OR,1. 15;95%CI 1. 09-1. 21;smoking:OR,1. 13;95%CI 1. 08-1. 17;and lack of physical exercise:OR,1. 12;95%CI 1.08-1. 16). (2)Hypertension,atrial fibrillation, smoking,and diabetes were the independent risk factors for carotid plaque and carotid artery stenosis rate≥50%(carotid plaque,hypertension:OR,1. 55;95%CI 1. 47-1. 62;atrial fibrillation:OR,1. 13;95%CI 1.06-1. 21;smoking:OR,1. 16;95%CI 1. 11-1. 22;and diabetes:OR,1. 30;95%CI 1. 24-1. 37). Carotid stenosis rate≥50%,hypertension:OR,1. 78;95%CI 1.55-2. 03;atrial fibrillation:OR,1. 59;95%CI 1. 39-1. 81;smoking:OR,1. 33;95%CI 1. 20-1. 48;and diabetes:OR,1. 30;95%CI 1. 17-1. 45. Simple obesity did not increase the incidences of carotid atherosclerotic plaque and carotid artery stenosis ≥50%(OR,0. 78, 0.83;95%CI 0. 75-0. 82 ,0. 75-0. 92,respectively). Conclusions Neck vascular ultrasound can be used as a valuable means for screening high-risk population and detecting risk factors of stroke. It has an important clinical significance for the early diagnosis and treatment of carotid atherosclerosis disease.

Objective:To analyze clinical characteristics of primary pancreatic lymphoma (PPL) patients.Methods:Clinical features of 22 patients diagnosed as PPL admitted to Peking Union Medical College Hospital from January 2002 to May 2023 were analyzed retrospectively.Results:The median age was 56.4±13.3 years. The median time from onset to diagnosis was 1.0 (1.0, 3.0) months. The main clinical manifestations were abdominal pain (15/22), weight loss (14/22) and jaundice (10/22). Elevated lactate dehydrogenase (LDH) was observed in 15/20 (75%) patients. Only 2 (2/9, 22.2%) patients had increased CA199 levels and 2 (2/9, 22.2%) patients had increased CEA levels. The maximum tumor diameter was 5.0 (3.8, 6.9) cm. Contrast-enhanced CT mostly showed low enhancement lesions. Major pancreatic duct dilatation were rare on CT scan (4/20). Fifteen patients were confirmed by pancreatic pathology, of which 8 were obtained by surgery, 4 were obtained by CT or ultrasound-guided percutaneous biopsy, and 3 were obtained by EUS-FNA. The main pathological type was diffuse large B-cell lymphoma (14/22). 19 patients received chemotherapy, and 6 patients died with a median follow-up of 5.0 (1.5, 35.5) months.Conclusions:PPL is rare and easy to be misdiagnosed. Elevated LDH levels, normal tumor markers, and non-dilatation of main pancreatic duct are important diagnostic clues. It is important to obtain pathology by EUS-FNA and other methods for definite diagnosis.