AIM To study whether chronic administration of methylamine may induce elevation of semicarbazide-sensitive amine oxidase (SSAO) activity and initiate the injury of cardiovascular endothelium. METHODS New Zealand rabbits were treated with methylamine hydrochloride (100 mg·kg-1) by ig, once a day for 6 months. The rabbits were weighed every other week and the dosage was adjusted according to the body weight. The number of circulating endothelial cells (CEC) in the arterial blood, nitric oxide (NO) concentration in the serum and ultrastructure of endothelial cells of aorta were assessed. The plasma SSAO activity and formaldehyde concentration were assessed by liquid chromatography. RESULTS The number of CEC, NO concentration, levels of SSAO activity and formaldehyde concentration in the methylamine group were increased significantly, compared with the control group. Ultrastructure of endothelial cells in the methylamine group showed inordinate morphological changes (multiple intranuclear inclusions, karyopyknosis and karyorrhexis). CONCLUSIONChronic administration of methylamine can induce the elevation of SSAO activity and initiate the injury of cardiovascular endothelium.

[ ABSTRACT] AIM:To observe the effect of the metabolites generated from oxidative deamination of methylamine ( MA) or benzylamine ( BZA ) catalyzed by semicarbazide-sensitive amine oxidase ( SSAO ) on 3T3-L1 adipocytes. METHODS:3T3-L1 preadipocytes were induced to differentiation.SSAO activity was determined by high performance liquid chromatography ( HPLC) at different differentiation time points.MTT assay was applied to detect cell vitality after exposure to different concentrations of MA or BZA.Fluorescence probe DCFH-DA was used to determine the production of reactive oxygen species after incubation of 3T3-L1 adipocytes with MA or BZA.After exposure to 0.5 mmol/L MA or BZA for 4 h, malondialdehyde ( MDA) , total superoxide dismutase ( T-SOD) and glutathione ( GSH) in the adipocytes or prea-dipocytes were measured.RESULTS:SSAO activity increased with the increase in the differentiation days, and reached a maximum at the 8th day.Incubation of the cells with different concentrations of MA or BZA for 4 h did not significantly de-creased the cell vitality (P>0.05).After exposure to 0.5 mmol/L MA or BZA, the reactive oxygen species in adipocytes significantly increased, and were about 3 to 4 times as compared with control group (P<0.05).After treatment with 0.5 mmol/L MA or BZA for 4 h, MDA content significantly increased, while the activity of SOD and the expression of GSH de-creased in mature adipocytes compared with control group (P<0.05).However, MDA, T-SOD and GSH did not change significantly after treatment with equal molar of MA or BZA in the preadipocytes ( P>0.05 ) .CONCLUSION: MA or BZA induces oxidative stress in the mature adipocytes, which might result from the deamination products catalyzed by SSAO.

AIM To study whether inhibition of semicarbazide (Sem)-sensitive amine oxidases (SSAO) attenuates myocardial ischemia-reperfusion (I-R) injury. METHODS Male Sprague-Dawley rats were randomly divided into 4 groups. Each group consisted of 10 rats. Sham group: the ligature was placed under the left coronary artery (LCA), but not ligated. Sham+Sem group: Sem (30 mg·kg-1, ip) was given 10 min prior to the experiment, the LCA ligature was not ligated. I-R group: the LCA was occluded for 30 min and reperfused for 180 min. I-R+Sem group: Sem (30 mg·kg-1, ip) was given 10 min prior to the experiment, and then 30 min ischemia followed by 180 min reperfusion. Myocardial infarct size was determined by using nitroblue tetrazolium staining. Plasma creatine kinase (CK) and myeloperoxidase (MPO) activities, and malondialdehyde (MDA) and hydroxyl radicals levels were determined by spectrophotometer. Plasma SSAO activity was determined by high performance liquid chromatography. HE staining was used for histopathological evaluation. RESULTS There were no significant differences on each index between sham and sham+Sem groups. Plasma MPO and SSAO activities, and MDA and hydroxyl radials levels significantly increased in I-R group, compared with sham group. Myocardial infarct size was remarkably smaller in I-R+Sem group (27.7±3.7)%, compared with I-R group (43.2±3.1)%. Plasma MDA level, MPO activity and hydroxyl radical level were lower in I-R+Sem group than those in I-R group, from (27.5±9.3) μmol·min-1·L-1,(2.6±0.4)mmol·L-1 and (628±50)mmol·min-1·L-1 down to (14.2±5.6)μmol·min-1·L-1,(1.7±0.5)mmol·L-1 and (503±88)mmol·min-1·L-1, respectively. Histological results showed that inhibition of SSAO activity significantly attenuated leukocyte infiltration. CONCLUSIONPlasma SSAO activity is increased in myocardial I-R injury and inhibition of SSAO can attenuate myocardial I-R injury.

Objective To investigate the predictive value of baseline neutrophil-to-lymphocyte ratio (NLR) in the curative effect and prognosis of breast cancer patients treated with neoadjuvant chemotherapy.Methods The clinical data of 304 breast cancer patients received neoadjuvant chemotherapy in Beijing Cancer Hospital during 2010 were retrospectively analyzed.The correlations of baseline NLR with clinicopathological parameters of breast cancer patients were analyzed by Wilcox or Kruskal-Wallis tests,and the correlation of NLR with pathologic complete response (pCR) after neoadjuvant chemotherapy was analyzed by the binary logistic regression.The effect of clinic pathological parameters on the disease-free survival(DFS) of the patients was evaluated by the univariable and muhivariable Cox regression models.Results The medians of NLR in pCR + patients (n =62) and pCR-patients (n =242) were 1.76 and 1.72,respectively,and there was no significant difference between themn (P ＞ 0.05).Multivariate analysis indicated that the TNM stage (P ＜ 0.05) and pCR (P ＜ 0.05) were the independent risk factors influencing the prognosis of breast cancer patients.There was no significant correlation between NLR and 5-year DFS (HR=0.842,95％CI=0.566-1.255,P＞0.05).Condusion NLR lacks the predictive value in the curative effect and prognosis of breast cancer patients treated with neoadjuvant chemotherapy,while TNM stage and pCR are the independent risk factors influencing the prognosis of breast cancer patients.

Objective:To provide evidence for optimizing the screening strategy for gastric cancer (GC), we evaluated the risk of incident GC for individuals with different precancerous gastric lesions in a prospective cohort study.Methods:Based on the National Upper Gastrointestinal Cancer Early Detection Program launched in Linqu, Shandong, a high-risk area of gastric cancer in China, we included a total of 14 087 subjects diagnosed with different gastric lesions stages by endoscopic screening from 2012 to 2018. Study subjects were prospectively followed up until December 31, 2019. The incidence of GC during the follow-up was ascertained by repeated endoscopic examinations, cancer, death registry reports, and active follow-up of study subjects and was confirmed by reviewing medical records extracted from the hospital information management system. The Poisson regression model was applied to calculate the relative risk ( RR) and 95% CI for GC occurrence among subjects with different gastric lesions. Results:Among 14 087 subjects with different gastric lesions as determined by their first endoscopic examination in 2012-2018, 7 608 (54.00%) had a global diagnosis of superficial gastritis (SG), 2 848 (20.22%) had chronic atrophic gastritis (CAG), 3 103 (22.03%) had intestinal metaplasia (IM), and 520 (3.69%) had low-grade intestinal neoplasia (LGIN). During the follow-up, 109 subjects were diagnosed with GC, including 63 with high-grade intestinal neoplasia (HGIN) and 46 with invasive GC. Compared to subjects having normal gastric mucosa or SG, those with CAG ( RR=3.85, 95% CI: 2.04-7.28), IM ( RR=5.18, 95% CI: 2.79-9.60), and LGIN ( RR=19.08, 95% CI: 9.97-36.53) had significantly increased risk of progression to GC. Individuals with these gastric lesions had an elevated risk of developing HGIN and invasive GC. For subjects with LGIN, the RR was 22.96 (95% CI: 9.71-54.27) for developing HGIN and 14.64 (95% CI: 5.37-39.93) for developing invasive GC. Subgroup analyses found that all age group subjects with LGIN diagnosed during the initial endoscopic examination had a significantly increased risk of developing the GC. Conclusions:Our large-scale prospective study on a high-risk area of GC showed that most residents aged 40-69 years had gastric lesions of different stages. Subjects with more advanced gastric lesions had a significantly increased risk of progression to GC.

The liquid chromatography tandem mass spectrometry was used to detect the urinary proteomics of 223 residents aged 40-69 years old who participated in the National Upper Gastrointestinal Cancer Early Detection Program in Linqu County, Shandong Province from November 22 to December 7, 2018, and analyze the alcohol consumption related proteomic profiles and individual urinary protein. There were significant differences in urinary protein profiles between alcohol consumption group and non-alcohol consumption group. The expression of 26 urinary proteins was up-regulated and 20 urinary proteins were down-regulated in alcohol consumption group ( P<0.05). The differentially expressed proteins had enzyme inhibitor activity and phospholipid binding function, and mainly enriched in pathways involving proximal tubule bicarbonate regeneration, complement and coagulation cascade, and cholesterol metabolism. The protein expressions of complement factor I (CFI), angiotensin converting enzyme 2 (ACE2) and protein C inhibitor (SERPINA5) were positively correlated with daily alcohol consumption.

The liquid chromatography tandem mass spectrometry was used to detect the urinary proteomics of 223 residents aged 40-69 years old who participated in the National Upper Gastrointestinal Cancer Early Detection Program in Linqu County, Shandong Province from November 22 to December 7, 2018, and analyze the alcohol consumption related proteomic profiles and individual urinary protein. There were significant differences in urinary protein profiles between alcohol consumption group and non-alcohol consumption group. The expression of 26 urinary proteins was up-regulated and 20 urinary proteins were down-regulated in alcohol consumption group ( P<0.05). The differentially expressed proteins had enzyme inhibitor activity and phospholipid binding function, and mainly enriched in pathways involving proximal tubule bicarbonate regeneration, complement and coagulation cascade, and cholesterol metabolism. The protein expressions of complement factor I (CFI), angiotensin converting enzyme 2 (ACE2) and protein C inhibitor (SERPINA5) were positively correlated with daily alcohol consumption.

Traditional survival methods have a wide application in the field of biomedical research. However, applying traditional survival methods requires data to meet a set of special assumptions while the Random Survival Forest model can overcome this inconvenience. Herein, we used the clinical data of Primary Biliary Cholangitis (PBC) from Mayo Clinic to introduce and demonstrate Random Survival Forest model from mathematical principles, model building, practical example and attentions, aiming to provide a novel method for doing survival analysis.

Traditional survival methods have a wide application in the field of biomedical research. However, applying traditional survival methods requires data to meet a set of special assumptions while the Random Survival Forest model can overcome this inconvenience. Herein, we used the clinical data of Primary Biliary Cholangitis (PBC) from Mayo Clinic to introduce and demonstrate Random Survival Forest model from mathematical principles, model building, practical example and attentions, aiming to provide a novel method for doing survival analysis.

Objective To improve the quality standards of Kunxian capsules (KC) and effectively control the product quality. Methods Triptolide, icariin and hypericin were used as the indicator components, to increase or improve the thin layer chromatography (TLC) identification methods of Kunming begonia, epimedium and dodder. Agilent ZORBA SB-C₁₈ (4.6 mm×250 mm, 5 μm) as a chromatographic column, the HPLC method for the determination of triptolide was improved with acetonitrile-0.1% formic acid solution as the mobile phase and 220 nm as the detection wavelength. Results The spots in the TLC method of Kunming begonia, epimedium and dodder has strong specificity, good and clear separation of characteristic spots, negative and no interference. The quantitative analysis of the content of triptolide in KC showed that there is a good linear relationship (r=0.9995) between the mass concentration of triptolide and the peak area in the range of 40.16-502.00 μg/ml, the average recovery was 98.12%, RSD was 8.25%, and the accuracy was good. Conclusion The TLC identification method and HPLC method established in this experiment have strong specificity and good reproducibility, and can effectively control the quality of KC.