Objective:To establish a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the fast determination of maduramicin ammonium (MAD) in rat serum.Methods:In February 2024, rat serum samples were selected and directly injected after extraction and purification with methanol: acetonitrile (1: 1), separated on a C18 chromatographic column, and gradient-eluted using 0.1% formic acid aqueous solution -0.1% formic acid methanol solution as the mobile phase. Under optimized instrument conditions, electrospray positive ion multiple reaction monitoring (MRM) mode was employed for quantification using the external standard method, followed by methodological validation of the established approach.Results:The linearity of MAD in serum was good in the concentration range of 0.5-100 μg/L, and the correlation coefficient was 0.9997. The mean recoveries of MAD from spiked samples were 86.0%-109.6%, with the relative standard deviations were less than 10%. The limit of detection was 0.23 μg/L, The limit of detection was 0.75 μg/L.Conclusion:This method is high sensitive and reliable, which is suitable for the determination of MAD in in mouse serum.

Objective:To establish a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the fast determination of maduramicin ammonium (MAD) in rat serum.Methods:In February 2024, rat serum samples were selected and directly injected after extraction and purification with methanol: acetonitrile (1: 1), separated on a C18 chromatographic column, and gradient-eluted using 0.1% formic acid aqueous solution -0.1% formic acid methanol solution as the mobile phase. Under optimized instrument conditions, electrospray positive ion multiple reaction monitoring (MRM) mode was employed for quantification using the external standard method, followed by methodological validation of the established approach.Results:The linearity of MAD in serum was good in the concentration range of 0.5-100 μg/L, and the correlation coefficient was 0.9997. The mean recoveries of MAD from spiked samples were 86.0%-109.6%, with the relative standard deviations were less than 10%. The limit of detection was 0.23 μg/L, The limit of detection was 0.75 μg/L.Conclusion:This method is high sensitive and reliable, which is suitable for the determination of MAD in in mouse serum.

Background Di(2-ethylhexyl) phthalate (DEHP) is the highest consumed and the most widely used phthalic acid ester, their effects on lipid metabolism have attracted the attention of many scholars. However, the associated mechanism is still unclear. Objective To observe the effect of DEHP on lipid metabolism in rats, probe its possible mechanism, and provide a research basis for the effect of DEHP on human lipid metabolism. Methods Forty healthy male SD rats were randomly divided into 4 groups: solvent control (0 mg·kg⁻¹ DEHP), low DEHP (187 mg·kg⁻¹), medium DEHP (375 mg·kg⁻¹), and high DEHP (750 mg·kg⁻¹) groups. DEHP was administered by oral gavage for 6 d per week, consecutively 8 weeks. The rats were weighed once a week during the exposure period. At 24 h after the last exposure, the rats were anesthetized with 20% urethane and sacrificed by apical puncture. Rat livers were harvested and weighed before hematoxylin-eosin (HE) histopathological observation. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA levels of lipid metabolism-related genes Janus kinase 3 (JAK3), signal transducer and activator of transcription 5b (STAT5b), and peroxisome proliferator-activated receptor γ (PPARγ) in liver, and Western blot was used to detect the expression levels of lipid metabolism-related proteins JAK3, STAT5b, and PPARγ in liver. Results Compared with the control group, there was no significant difference in the body weight gain of the rats in each group (P>0.05). The liver organ coefficients of the DEHP exposure groups were higher than that of the control group (P<0.001), and increased with higher DEHP dosages. The level of high-density lipoprotein cholesterol (HDL-C) in serum decreased in all DEHP exposure groups (P<0.05), and the level of low-density lipoprotein cholesterol (LDL-C) in serum increased in the high DEHP group (P<0.05). The results of liver histopathological morphology showed that the hepatocytes of each DEHP group were enlarged and edematous in varying degrees, with loose stroma and irregular arrangement of cells, which were manifested as inflammatory cell infiltration and fatty degeneration of liver cells. Compared to the control group, the mRNA levels of JAK3, STAT5b, and PPARγ in liver tissues of rats in each DEHP group decreased (P<0.001). Compared to the control group, the relative expression levels of JAK3 in each DEHP group decreased (P<0.05), and the relative expression levels of STAT5b and PPARγ in the medium and high DEHP groups decreased (P<0.05). Conclusion DEHP exposure can induce abnormal lipid metabolism in rats, and the mechanism may be related to DEHP inhibiting the activation of JAK3/STAT5b/PPARγ signaling pathway.

Objective:To investigate the association between body mass index (BMI) trajectories in children and adolescents and subclinical renal damage (SRD) in adulthood.Methods:4 623 participants aged 6-18 years old were recruited from the ongoing cohort of Hanzhong adolescent hypertension study in 1987, and the subjects were followed up in 1989, 1992, 1995, 2005, 2013 and 2017, respectively. Group-based trajectory modeling was used to identify distinct BMI trajectories in longitudinal analysis. Generalized linear model was applied to examine the association between different BMI trajectories and SRD incidence in adulthood.Results:A total of 2 678 subjects from childhood to adulthood were enrolled in this study. All subjects were divided into three groups according to three distinct BMI trajectories: low-increasing BMI group ( n=1 017), moderate-increasing BMI group ( n=1 353), and high-increasing BMI group ( n=308). Over follow up for 30 years, a total of 248 participants (9.3%) developed SRD. Urinary albumin-to-creatinine ratio (uACR) in low to high-increasing BMI group was 0.9(0.6, 1.4), 1.0(0.7, 1.7), 1.6(0.8, 3.2), respectively ( P trend<0.001), and estimated glomerular filtration rate was 98.5(87.6, 111.6) , 96.2(86.4, 109.7), 95.3 (87.5, 125.0) ml·min -1·(1.73 m 2) -1, respectively ( P trend=0.025). The generalized linear model analysis showed that uACR was increased linearly from low to high-increasing BMI group [ β=3.16(95% CI 1.02-5.31), Ptrend=0.004]. There was no correlation or linear trend between BMI trajectory and estimated glomerular filtration rate [ β=-2.30(95% CI-5.18-0.57), Ptrend=0.117]. Compared with the low-increasing BMI group, the high-increasing BMI group had greater odds of experiencing SRD in adulthood after adjusting for multiple confounders such as age, gender, medical history and lifestyle ( OR=2.83, 95% CI 1.84-4.36, Ptrend<0.001). Conclusions:Higher BMI trajectorie is correlated with higher level of uACR and risk of SRD in middle age. Identifying long-term BMI trajectorie from early age may assist in predicting individuals′ renal function in later life.

【Objective】 Based on our previously established salt-sensitive hypertension cohort, we conducted chronic salt loading and potassium supplementation interventions, aiming to examine the association between genetic variants in renalase and blood pressure (BP) responses to dietary interventions of salt and potassium intake. 【Methods】 In 2004, 514 subjects from 126 families were recruited in Shaanxi Province to establish the salt-sensitive hypertension study cohort. Among them, 334 non-parent subjects were selected and sequentially maintained on a low-salt diet for 7 days, then a high-salt diet for 7 days and a high-salt diet with potassium supplementation for another 7 days. Ten single nucleotide polymorphisms (SNPs) in the renalase gene were genotyped on the MassARRAY platform. 【Results】 SNP rs2576178 of the renalasegene was significantly associated with systolic BP (SBP) and mean arterial pressure (MAP) responses to low-salt intervention (SBP: β=-2.730, P<0.05; MAP: β=-1.718, P<0.05). In addition, SNP rs12356177 was significantly associated with diastolic BP response to low-salt diet (β=-1.608, P<0.05). However, we did not find any association for the renalase SNPs with BP response to high-salt diet with potassium supplementation reached nominal statistical significance. 【Conclusion】 Genetic variants in renalase gene are significantly associated with BP response to low-salt diet, suggesting that renalase may be mechanistically involved in BP salt-sensitivity.

Purpose To explore the feasibility of double low dose technology in multi-slice head and neck CT angiography, so to reduce contrast agent as well as reduce radiation dose. In that way, the hazards of radiation and the risk of contrast induced nephropathy would be reduced. Materials and Methods Fifty-one patients took double low proposal were recruited as double low group. Another 51 patients who took conventional proposal were recruited as conventional group. The scanning parameters of double low group were 100 kV, 300 mA, 0.7 ml/kg iodinated contrast agent and which of conventional group were 120 kV, 350 mA, 1.0 ml/kg iodinated contrast agent. The CT value of the vessels and image noise were measured. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), subjective image quality score, radiation dose and iodine load between the two groups were compared. Results The volume CT dose index (CTDIvol) of the double low group and the conventional group were 18.00 mGy and 33.86 mGy, respectively. And the effective dose were 3.85 mSv/(mGy · cm) and 7.25 mSv/(mGy · cm), respectively. The iodine loads were 224 mgI/kg and 320 mgI/kg, respectively. SNR and CNR at the aortic arch were higher in double low group than in conventional group, but which was not statistic significant (t=-1.572 and -1.783, P>0.05). The SNR and CNR of bilateral carotid arteries, internal carotid arteries, and middle cerebral arteries had no statistic significance between the two groups (t=0.341-1.739, P>0.05). The subjective image quality scores of double low group and conventional group were (3.69±0.47) scores and (3.70±0.46) scores, which showed no statistic difference (Z= - 0.213, P>0.05). Conclusion Approving images of multi-slice head and neck CT angiography can be obtained by using double low dose technology without adaptive statistical iterative reconstruction.