Objective:A high performance liquid chromatography (HPLC) method was developed to determine the enzymatic activity of CD38 in blood, which was the major enzyme responsible for consuming nicotinamide adenine dinucleotide (NAD). Additionally, the study aimed to detect the differences in CD38 enzymatic activity among individuals of varying ages and health statuses.Methods:A 50 μl whole blood matrix and enzyme reaction substrate of 150 μl β-NAD at a concentration of 500 μmol/L were selected for the analysis. To eliminate the impact of endogenous β-NAD, the whole blood sample was pre-incubated at 37 ℃ for 20 minutes before adding the substrate. The reaction was terminated by perchloric acid (PCA) after incubation at 37 ℃ for 40 min. The change in product nicotinamide (NAM) before and after the enzymatic reaction was measured by HPLC to calculate the CD38 activity. The linearity, limit of detection, limit of quantification, precision, and stability of the method were evaluated. The CD38 enzymatic activities in 60 healthy volunteers and 30 colorectal cancer patients in blood were determined by the developed method.Results:Pre-incubation at 37 ℃ for 20 minutes eliminated the effect of endogenous β-NAD. The correlation coefficient of NAM was 0.999 in the concentration range of 0.1-3.2 μmol/L, with limit of detection of 0.5 nmol/L and limit of quantification of 2.1 nmol/L. The average within-run imprecision ( CV) and total CV were 3.22%-4.03% and 2.91%-4.70%, respectively. The recovery rate ranged from 94.82% to 96.81%. The CD38 activity of whole blood was stable by storage at 4 ℃ for 48 hours, storage at room temperature for 8 hours, thawing of frozen whole blood at room temperature for 2 hours, or repeated freeze-thawing three times. NAM, NAD standards, and pre-treatment samples were stable after 48 hours at 4 ℃ and 8 hours at room temperature. CD38 activity gradually decreased with increasing concentration of the added CD38 inhibitor 4-aminoquinoline derivative (78c). Measurement of 60 healthy physical examination population samples showed significantly higher CD38 enzyme activity in the elderly group than that in the young group ( t=-2.776, P=0.007) and measurement of 30 colorectal cancer patients showed significantly higher CD38 enzyme activity than that in healthy people ( t=-2.572, P=0.012). Conclusion:The established HPLC method for determining CD38 enzymatic activity is characterized by its simplicity, efficiency, accuracy, and reproducibility. This technique serves as a valuable tool for investigating aging and aging-related diseases.

Population aging increases the demand for human aging research and its clinical applications.Traditionally, the chronological age(CA), that is, the age based on the calendar, is used to describe the state of aging.However, the aging process and speed among individuals are not consistent and often show clear individual differences in biological aging.Therefore, CA cannot truly reflect people's conditions of body structure and function, has drawbacks leading to unreliable and wrong assessment, and is unable to accurately describe the human body's state of aging.In recent years, it has been proposed that the biological age(BA)should be used to more comprehensively and accurately describe the stage of human aging.Combining mathematical algorithms with a variety of biomarkers, predictive models can be constructed to quantify BA.These approaches have been increasingly appreciated for their improved accuracy and received further investigation.This article reviews the value of BA, currently commonly used calculation methods and their progress and prospects in healthy aging.

Mendelian randomization is a genetic epidemiological method for confounding adjustment of cross-sectional data by introducing genotypes as instrumental variables of exposure factors and possesses unique advantages for the adjustment of unmeasured and unknown confounding factors.In recent years, Mendelian randomization has been widely used and achieved rapid progress in the etiology research of common diseases in the elderly.This article reviews this method and its application in these diseases, including cardiovascular disease, type 2 diabetes mellitus, osteoporosis, Alzheimer's disease and malignant tumor.

Elevated levels of circulating branched-chain amino acids(BCAA)increase the risk of cardiometabolic diseases(CMD)and may be a new risk factor for CMD.However, BCAA have been used as dietary supplements to promote health in clinical nutrition and medicine.BCAA are essential amino acids that must be acquired from food sources.Whether BCAA supplements can cause elevated circulating BCAA levels and consequently lead to CMD is still controversial.Recent studies have found that the roles of BCAA may vary under different conditions such as energy excess, energy deficiency and energy balance.This article reviews recent advances in research on BCAA and CMD.

Objective To propose and validate a reduced volume β-quantification method to measure serum high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Methods The reduced volume β-quantification method involved separation of LDL and HDL by ultracentrifugation and preparation of HDL by chemical precipitation. The sampling and reconstitution of the bottom fractions were performed gravimetrically and sample volume was thus decreased from 5 to 0.8 ml. High performance liquid chromatography was used to determine the cholesterol concentration of bottom fractions and HDL-C in the supernatant. Serum levels of LDL-C depended on a calculation of bottom fractions cholesterol minus HDL-C. Results The total CVs for HDL-C and LDL-C were 0.65％ -1.75％ and 0.63％ -1.11％. The results of the developed method were consistent with the current reference method and well within the allowable bias for Cholesterol Reference Method Laboratory Network surveys. Conclusion A new method for the measurement of HDL-C and LDL-C has been established. This method requires a small amount of serum and is easy to operate, exhibiting a desirable precision and accuracy. It is reliable and can be used as a candidate reference method for HDL-C and LDL-C.

PURPOSE: Numerous previous studies have reported inconsistent results about the differences between synchronous contralateral breast cancer (sCBC) and metachronous contralateral breast cancer (mCBC). This study aimed to compare the clinical characteristics and outcomes between sCBC and mCBC and determine predictive factors for the survival of sCBC and mCBC patients. METHODS: Using the Surveillance, Epidemiology, and End Results Program database, we identified sCBC or mCBC patients from 2000 to 2010. The Kaplan-Meier method and Cox proportional hazards regression analysis were used to analyze overall survival and breast cancer-specific survival (BCSS) rates of sCBCs and mCBCs, respectively. RESULTS: Overall, 14,057 sCBC (n = 8,139, 57.9%) and mCBC (n = 5,918, 42.1%) patients were included. The first tumors of sCBC were more likely to have higher stage and more lymph and distant metastases, whereas those of mCBC were more often infiltrating ductal carcinoma (IDC), had localized stage, were estrogen receptor (ER) and progesterone receptor (PR) negative, and had less axillary nodal involvement. The second tumors of mCBC tended to be IDC and have higher grade, adverse stage, ER and PR-negativity; and more axillary nodal involvement, compared to the second tumors of sCBC. mCBC patients had significantly favorable 5-year BCSS but worse long-term BCSS compared with sCBC patients. Moreover, subgroup analysis revealed no significant difference of BCSS between sCBC and mCBC among patients aged 18–60 years. Multivariate analysis indicated that age, grade, and stage of 2 tumors; surgery for second tumor; and ER status of the second tumor were independent prognostic factors for BCSS of contralateral breast cancer (CBC). CONCLUSION: The characteristics and outcomes of sCBCs and mCBCs were substantially different. sCBC and mCBC patients may have different prognosis, and the prognosis of CBC depends on the first and second tumors.
Age of Onset ; Breast Neoplasms ; Breast ; Carcinoma, Ductal ; Estrogens ; Humans ; Methods ; Multivariate Analysis ; Neoplasm Metastasis ; Prognosis ; Receptors, Progesterone ; Risk Factors ; SEER Program

Objective To establish a method for measuring blood phosphatidylethanol by liquid chromatography coupled with tandem mass spectrometry(LC-MS/MS), which can be applied for objective and quantitative of alcohol intake.Methods Whole blood samples were treated with isopropanol to precipitate protein,and phosphopropanol(16:0/16:0)was used as the standard.After centrifugation, the supernatants were transferred and evaporated under a stream of nitrogen until dryness.Then the residuals were analyzed by LC-MS/MS.Various methodological parameters, including linearity, limit of detection (LOD), limit of quantitation(LOQ), recovery, and precision, were investigated.Finally, blood samples from 40 Chinese individuals with more than one year of regular drinking habits were analyzed, and distributions of phosphatidylethanol were evaluated.Results The correlation coefficients were higher than 0.9992.The LOD and LOQ were lower than 0.74 and 2.48 ng/ml, respectively.The inter-and total assay coefficient of variations were 0.77%-3.18% and 2.30%-6.95%, respectively, with recoveries ranged from 96.88% to 102.99%.The relationship between phosphatidylethanol level and self-reported alcohol consumption was significantly and positively correlated(r =0.769, P <0.001).Furthermore, Kruskal-Wallis analysis showed a significant difference in total phosphatidylethanol levels among individuals with different levels of alcohol intake(χ2=18.850,P<0.001).Conclusions An LC-MS/MS method for whole blood phosphatidylethanol detection has been developed.This method is simple,sensitive and accurate and can effectively reflect light,moderate and heavy alcohol intake.The method will be applied to the assessment of alcohol consumption and its association with the risks of drinking related diseases.

Objective To examine the stability of high-density lipoprotein cholesterol (HDL-C)during serum incubation at different temperature and time periods.Methods Ten healthy volunteers (4 males and 6 females,aged 24 to 59 years)from Beijing Hospital were recruited in May 2015.Fasting venous blood samples were collected and centrifuged to separate the sera.Serum samples were incubated at 4℃ for 24 h,25℃for 0,1,8 and 24 h (with or without an LCAT inhibitor).Serum to-tal cholesterol (TC),total free cholesterol (TFC)HDL-C and HDL-FC were measured by the HPLC Method.Results HDL-FC and HDL-C changed -6.91% and -2.17% during serum incubation at 4℃for 24h.TFC,HDL-FC and HDL-C changed significantly (averaged -13.70%,-25.88% and -1.53% respectively)during serum incubation at 25℃ for 24 h,in which the decrease of TFC and HDL-FC were inhibited by the addition of the LCAT inhibitor.The decrease of HDL-C was even higher in the presence of the LCAT inhibitor.Conclusion Serum TFC,HDL-C and HDL-FC levels changed during serum incubations,which were caused by the LCAT and CETP activities and the transfer of cholesterol among lipoproteins. For accurate measurement of serum HDL-C,prolonged serum storage should be avoided in clinical laboratories.

Objective To develop a solid phase extraction and Folin-Ciocalteu method for the measurement of total polyphenols in urine samples.Methods From a group of individuals attending an annual physical examination at Beijing hospital, 123 healthy volunteers (52 males and 71 females, ranging in age from 18 to 81 years ) were recruited during the period from December 2013 to April 2014.Urine samples were stored in 0.5%HCl at -80 ℃.For analysis, samples were applied to the Plexa PAX solid phase extraction cartridge, to purity the polyphenols through washing, evaporating and reconstituting.Total polyphenols were measured by Folin-Ciocalteu colorimetric assay, calculated by gallic acid standard curve, and corrected by urine creatinine concentrations.The relationship between total polyphenols and fruits and vegetable intake and cardiovascular disease risk factors were analyzed. Results Gallic acid standard solution and urine samples were stable in 0.5% HCl for 48 h at RT and 7days at 4 ℃, respectively.The PAX cartridge effectively eliminated the possible interfere materials in urine and had better recovery for most of the polyphenol types.The inter assay and total CVs for the measurement of total polyphenols were 2.7%-3.8% and 2.4%-4.6 %, respectively.Total polyphenol concentrations of 123 healthy subjects were 114.13(82.97-146.70) mg GAE/g Crea.Total polyphenol levels positively correlated with both HDL-C (r=0.194, P=0.032) and apoAI (r=0.312,P<0.001), and negatively correlated with serum uric acid levels(r=-0.220,P=0.014).Conclusions We established a measurement of total polyphenols in urine samples using solid phase extraction and Folin-Ciocalteu method.This simple, precise method reliable and may be use to assess dietary polyphenols intake.

[Objective] To observe the clinical effect of applying wet union principle in saccharose treating pressure sores.[Method] Randomly divide 44 cas-es into treatment group 25 cases and control group 19 cases. Both groups were actively treated with primary diseases, the control one with hydrogen per-oxide, NS and traditional therapy of iodine; the treatment one added with saccharose applied on surface of sores; 1m as a course, after 1 course, compare their treatment results.[Results] In treatment group, the total effective rate, treating period and times al were al better than control group, the difference of the comparison had statistical meaning.[Conclusion] Adding saccharose to treat pressure sores can cure the sores surface more quickly and shorten the treat-ing period, is the ideal method for pressure sores.