Objective To explore the method for measurement of tritium in nuclear power plant liquid effluent purified by a mixed ion-exchange resin, to verify the feasibility of the method by experiments, and to provide technical support for the development of standard methods for the measurement of tritium in liquid effluent of nuclear power plants. Methods The purification effect of the mixed ion-exchange resin was determined by measuring the quenching factor, conductivity, and β-nuclide adsorption efficiency of the samples purified using the resin. A comparison was made between the ion-exchange resin method and the atmospheric distillation method for tritium determination. The precision and accuracy of the method were verified by calculating the relative standard deviation and the recovery in repeated measurement of samples with different activity concentrations and spiked samples. Results There were no significant differences in quenching factor, conductivity, and tritium activity concentration between the two methods. The adsorption efficiencies of EC20MB resin for common β-nuclides such as carbon, iron, nickel, strontium, yttrium, and cesium ranged from 99.28% to 99.88%. Repeated measurement of the same sample showed relative standard deviations of 5.2%-9.4% and recoveries of 86.8%-107%. Conclusion There were no significant differences between the results of the ion-exchange resin purification method and the atmospheric distillation method. The precision and accuracy of the method met the requirements of the ecological and environmental management authorities for monitoring tritium in liquid effluent from nuclear power plants. This method can be widely used in daily monitoring work.

Objective To investigate the effects of the estrogen synthesis inhibitor letrozole on the composition,diversity,and abundance of the intestinal microbiota in rats with polycystic ovary syndrome(PCOS).Methods A rat model of PCOS was induced using the estrogen synthesis inhibitor letrozole.The gut microbiota structures of normal and PCOS rats were analyzed 16S rRNA sequencing.Results At the phylum level,rats in the PCOS group had a lower abundance of Firmicutes(73.29%±5.34%vs.77.17%±4.01%)and a higher abundance of Bacteroidetes(23.85%±6.22%vs.17.21%±6.90%)compared with the normal group.At the genus level,the abundances of Rochella(5.61%±3.20%vs.16.13%±6.20%)and Zurichella(1.75%±2.23%vs.9.98%±7.34%)were lower in the PCOS group than in the normal group,but the abundances of Lactobacillus(18.83%±11.50%vs.15.88%±7.06%),Prevotella(4.58%±1.09%vs.0.46%±0.15%),and Ruminococcus(2.97%±1.56%vs.1.16%±0.60%)were increased.Analysis of Kyoto Encyclopedia of Genes and Genomes signaling pathways of the differentially expressed bacteria showed that signaling pathways related to bile acid biosynthesis in the intestine were changed in the PCOS rat model.Conclusions The structure of intestinal flora in PCOS rat model constructed by intragastric administration of letrozole is significantly disordered,which may be related to the signaling pathways related to bile acid biosynthesis.

Microplastics(MPs)and nanoplastics(NPs)have become hazardous materials due to the massive amount of plastic waste and disposable masks,but their specific health effects remain uncertain.In this study,fluorescence-labeled polystyrene NPs(PS-NPs)were injected into the circulatory systems of mice to determine the distribution and potential toxic effects of NPs in vivo.Interestingly,whole-body imaging found that PS-NPs accumulated in the testes of mice.Therefore,the toxic effects of PS-NPs on the reproduction systems and the spermatocytes cell line of male mice,and their mechanisms,were investigated.After oral exposure to PS-NPs,their spermatogenesis was affected and the spermatogenic cells were damaged.The spermatocyte cell line GC-2 was exposed to PS-NPs and analyzed using RNA sequencing(RNA-seq)to determine the toxic mechanisms;a ferroptosis pathway was found after PS-NP exposure.The phenomena and indicators of ferroptosis were then determined and verified by ferroptosis inhibitor ferrostatin-1(Fer-1),and it was also found that nuclear factor erythroid 2-related factor 2(Nrf2)played an important role in spermatogenic cell ferroptosis induced by PS-NPs.Finally,it was confirmed in vivo that this mechanism of Nrf2 played a protective role in PS-NPs-induced male reproductive toxicity.This study demonstrated that PS-NPs induce male reproductive dysfunction in mice by causing spermatogenic cell ferroptosis dependent on Nrf2.

Breast cancer is one of the most malignant tumors and is associated with high mortality rates among women. Lycium barbarum polysaccharide (LBP) is an extract from the fruits of the traditional Chinese herb, L. barbarum. LBP is a promising anticancer drug, due to its high activity and low toxicity. Although it has anticancer properties, its mechanisms of action have not been fully established. Ferroptosis, which is a novel anticancer strategy, is a cell death mechanism that relies on iron-dependent lipid reactive oxygen species (ROS) accumulation. In this study, human breast cancer cells (Michigan Cancer Foundation-7 (MCF-7) and MD Anderson-Metastatic Breast-231 (MDA-MB-231)) were treated with LBP. LBP inhibited their viability and proliferation in association with high levels of ferroptosis. Therefore, we aimed to ascertain whether LBP reduced cell viability through ferroptosis. We found that the structure and function of mitochondria, lipid peroxidation, and expression of solute carrier family 7 member 11 (SLC7A11, also known as xCT, the light-chain subunit of cystine/glutamate antiporter system X_c^-) and glutathione peroxidase 4 (GPX4) were altered by LBP. Moreover, the ferroptosis inhibitor, Ferrostatin-1 (Fer-1), rescued LBP-induced ferroptosis-associated events including reduced cell viability and glutathione (GSH) production, accumulation of intracellular free divalent iron ions and malondialdehyde (MDA), and down-regulation of the expression of xCT and GPX4. Erastin (xCT inhibitor) and RSL3 (GPX4 inhibitor) inhibited the expression of xCT and GPX4, respectively, which was lower after the co-treatment of LBP with Erastin and RSL3. These results suggest that LBP effectively prevents breast cancer cell proliferation and promotes ferroptosis via the xCT/GPX4 pathway. Therefore, LBP exhibits novel anticancer properties by triggering ferroptosis, and may be a potential therapeutic option for breast cancer.
Breast Neoplasms/drug therapy* ; Drugs, Chinese Herbal/pharmacology* ; Female ; Ferroptosis ; Glutathione/metabolism* ; Humans ; Iron/metabolism*

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Background: Pancreatic encephalopathy (PE) is one of the severe systemic complications of severe acute pancreatitis (SAP). In recent years, the incidence of PE was on the rise. There are few tools for early prediction of SAP complicated with PE. Aims: To screen the early independent risk factors of PE from clinical testing indices and scoring system of SAP patients, and then construct an early predictive scoring model of PE and used for intervening in advance. Methods: The clinical data of 130 patients with SAP from Jan. 2016 to Sept. 2020 at Shaanxi Hanzhong 3201 Hospital were analyzed retrospectively. Early independent risk factors of PE was screened by univariate analysis and multivariate Logistic regression analysis. The predictive scoring model was constructed by the weighted least square method. Results: Univariate analysis showed that history of alcohol abuse, lactic acid, intra-abdominal pressure (IAP), CT severity index (CTSI), extrapancreatic inflammation on CT (EPIC) and Glasgow coma scale (GCS) score were correlated to PE (P<0.05). Multivariate Logistic regression analysis showed that history of alcohol abuse (OR=2.843, 95% CI: 1.759-4.595, P=0.011), IAP (OR=1.077, 95% CI: 1.020-1.138, P=0.007), and EPIC score (OR=1.768, 95% CI: 1.181-2.649, P=0.006) were independent risk factors for PE in the early stage. According to the early predictive scoring model constructed, risk of PE was divided into low risk (0-3), medium risk (4-6) and high risk (>6), and differences in the incidence of PE in SAP patients among the three groups were statistically significant (P<0.05). Conclusions: The predictive scoring model constructed has the value for early prediction and evaluation of SAP complicated with PE, and risk stratification is helpful for taking intervention measures in advance to reduce the incidence of PE.

BACKGROUND: In recent years, the development of tissue engineering has provided a new approach for the treatment of periodontal bone defect. Tissue engineering therapy includes seed cells, scaffolds and growth factors. Platelet gel contains a large number of platelet growth factors, and collagen is often used for the preparation of scaffold materials. Therefore, the platelet gel and collagen biologically active composite membrane can provide scaffolds and growth factors for the defect bone. OBJECTIVE: To investigate the effect of autologous platelet gel-collagen biologically active composite membrane on the repair of periodontal bone defect in rats. METHODS: Forty-two Wistar rats (Shanghai Xipuer-Bikai Experimental Animal Co., Ltd., China) were selected. (1) Collagen was cut into 5 mm×2 mm size, and 10 mL of whole blood was extracted from 6 rats to obtain platelet-rich plasma. Autologous platelet gel-collagen composite membrane was prepared by adding bovine thrombin, calcium chloride and collagen in a certain proportion. Platelets in whole blood and in platelet-rich plasma were detected. The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in whole blood and platelet-rich plasma were detected by ELISA. (2) The models of mandibular periosteal defect were established in 36 rats (the size of the bone defect was 5 mm×2 mm, and the root surface cementum was removed) , and randomly divided into two groups. Autologous platelet gel-collagen group placed the autologous platelet gel-collagen composite membrane in the bone defect, and the control group did not place any materials. The hematoxylin-eosin staining of periodontal tissues of rats in each group was analyzed at 2, 4 and 8 weeks after surgery. Rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height were measured. The expression of bone morphogenetic protein-2 was detected by immunohistochemical staining. RESULTS AND CONCLUSION: (1) The mean platelet count in platelet-rich plasma was 4.78 times as high as the whole blood, indicating that the number of platelets increased significantly after prepared into platelet-rich plasma (P < 0.05) . The levels of platelet derived growth factor AB, transforming growth factor-β, basic fibroblast growth factor and vascular endothelial growth factor in platelet-rich plasma were 3.10, 3.45, 7.17 and 5.45 times of the whole blood, respectively (P < 0.05) . (2) The results of hematoxylin-eosin staining observed that the rate of new born, new centumum formation, new alveolar bone formation, and new periodontal ligament tissue formation height at 2 weeks in the autologous platelet gel-collagen group showed no significant difference from the control group (P> 0.05) . At 4 and 8 weeks, all above indexes in the autologous platelet gel-collagen group were significantly higher than those in the control group (P < 0.05) . (3) Results of immunohistochemical staining revealed that at 2 weeks, bone morphogenetic protein-2 in the autologous platelet gel-collagen group began to express, and the expression of bone morphogenetic protein-2 was highest at 4 weeks (P < 0.05) , and the positive expression was weakened at 8 weeks (P> 0.05) . (4) Our results clarify that autologous platelet gel-collagen bioactive composite membrane can significantly promote the regeneration of new tooth, which is associated with the expression of bone morphogenetic protein-2, and reduce the repair time after periodontal tissue defect.

Objective To explore the efficacy of moderate dose bromocriptine by one-off oral administration in treatment of patients with non-acute prolactin (PRL) type pituitary adenoma.Methods Forty-three patients with definite diagnosis of non-acute prolactin type pituitary adenoma,admitted to our hospital from January 2016 to December 2017,were chosen in our study.All patients were administrated with 5 mg bromocriptine at 18 pm;the serum PRL levels were examined at 2,3 and 12 h after bromocriptine administration.The curative effects of these patients were judged by decline rate of PRL,and the curative effects of patients with different genders,different initial PRL levels and different ages were compared.Results In these 43 patients,bromocriptine showed excellent effect in 20 patients,obvious effect in 18 and invalid effect in 5.There were statistically significant differences in the efficacy of bromocriptine between different genders (P＜0.05).There were statistically significant differences in efficacy of patients with different genders after taking bromocriptine (P＜0.05).The female patients had obviously higher rate of obvious effect than the male patients.Patients with different initial PRL values had statistically significant differences in efficacy after taking bromocriptine (P＜0.05).Patients with PRL initial value of 40-200 ng/mL had significantly higher rate of obvious effect than patients with PRL initial value of ＞200 ng/mL.There was no significant difference in efficacy between patients ＜ 45 years old and patients＞45 years old (P＞0.05).Conclusion The treatment ofhyperprolactin caused by prolactin type pituitary adenoma with moderate dose bromocriptine by one-off oral administration is effective;female patients have obviously better effect than male patients;and for patients with initial prolactin＞200 ng/mL,the effect is better.

The term,cerebral small vessel disease (CSVD),describes a syndrome of neuroimaging,pathological,and associated clinical features caused by small intracranial vascular lesions.Recent studies have found different MRI features of CSVD in patients with ischemic strokes caused by large artery atherosclerosis (LAA),significantly influencing the stroke outcomes.This paper reviews the effects of CSVD on clinical outcomes of cerebral infarction patients caused by LAA and their mechanisms.

Chronic liver diseases can further develop to liver fibrosis and cirrhosis. Currently, there is no effective treatment except liver orthotopic transplantation at this point. The extreme shortage of liver organ source forced people to find alternative treatment strategies. Mesenchymal stem cells ( MSCs) have the abilities of immunomodulatory, hepatocyte differentiation, promotion of liver cells regeneration in situ and inhibiting the activation of hepatic stellate cells. Therefore, MSCs transplantation provides a very broad prospect for cell therapy. It is important to provide preclinical evaluation of the efficacy and safety before the application of cell therapy in clinical trials. The progress of various animal models of human liver diseasees and significance of using MSCs to treat liver diseases in preclincal studies based on these animal models were reviewed in this paper.