OBJECTIVETo study the bioaffinity between 8 bufadienolides(Bu) and tumor cells and analyze the correlation between the bioaffinity and the anti-tumor activities of Bu.

METHODMix and cultivate the chloroform extract of Chansu and MGC-803. Measure the content of 8 Bu in supernatant and cells using HPLC and calculate their affinity rate.

RESULTThe coefficient correlation between the decrease of Bu in cell supernatant after affinity and its MGC-803 restrictive activities, and between the cotent percentage of the free Bu in free cells with its MGC-803 restrictive activities, and between the difference between the decrease and the percentage and its MGC-803 restrictive activities is r = 0.82 (P < 0.05), r = -0.04 and r = 0.83 (P < 0.05) respectively.

CONCLUSIONEight Bu have different levels of affinity with MGC-803 which correlate with their anti-tumor activities.

Amphibian Venoms ; chemistry ; Animals ; Antineoplastic Agents ; isolation & purification ; pharmacology ; Anura ; Bufanolides ; isolation & purification ; pharmacology ; Cell Line, Tumor ; Chromatography, High Pressure Liquid ; methods ; Neoplasms ; drug therapy

Objective:To study the expression of zonula occludens-1(ZO-1) in neonates with necrotizing enterocolitis (NEC) and to explore the effects of disialyllacto-N-tetraose (DSLNT), a compound extracted from human milk, on the intestinal barriers in rat model of NEC.Methods:(1) Human study: From Feb 2013 to Dec 2020, the pathological samples of ileum tissue from 21 neonates (12 patients with NEC and 9 with intestinal atresia) from Pathology Department of our hospital were collected. The expressions of ZO-1 in these samples were examined using immunohistochemistry (IHC) method. (2) Animal study: A total of 28 newborn rats were randomly assigned into control group ( n=8), NEC group ( n=10) and DSLNT+NEC group ( n=10). Experimental NEC model was established based on hypoxia (95%N 2 10 min) /cold exposure (4 ℃ 10 min) three times a day for consecutive 3 days. DSLNT+NEC group were fed with formula+DLSNT (300 μmol/L) during hypoxia/cold exposure. All the surviving rats were sacrificed at the end of the experiment (72 h) and the terminal ileum tissues were collected. Hematoxylin-Eosin (HE) staining was used to evaluate tissue damage and Western blotting was used to determine the expressions of ZO-1. (3) Cellular study: Bacterial lipopolysaccharide (LPS) was used to establish a cellular inflammation model in human intestinal epithelial cell lines (Caco-2) and DSLNT (300 μmol/L) was applied to this model. Thiazolyl blue assay was used to examine cell viabilities and immunofluorescence assay was used to detect ZO-1 expression. The effects of DSLNT on cell growth and tight junctions of Caco-2 cells were analyzed. Results:(1)Human study: The villi of mucous layer of the lesion were damaged in NEC patients. ZO-1 expressions at the epithelial junction of NEC patients were decreased compared with intestinal atresia patients and non-lesion intestines of NEC patients. (2)Animal study: Apical extrusion, necrosis and shedding of epithelial cell were seen at the lesions in NEC group. The expression of ZO-1 in NEC group was significantly lower than the control group and DSNLT+NEC group ( P<0.05).DSNLT+NEC group had higher survival rates (8/10 vs. 6/10) and lower ileum inflammatory pathological scores [2.0(1.0, 2.8) vs. 3.5(3.0, 4.0)] than NEC group. (3) Cellular study: Caco-2 cells exposed to LPS showed inhibited cell growth and decreased ZO-1 immunofluorescence staining. Caco-2 cells in the DSLNT+LPS group showed better viability than LPS group and were comparable with the control group. The expression of ZO-1 was significantly increased in the DSLNT+LPS group. Conclusions:Tight junction injury of the intestinal epithelial cell is an important characteristic of NEC. ZO-1 is a potential target for the prevention and treatment of NEC. DSLNT may protect the neonatal intestines by modulating the expression of ZO-1 and keeping tight junction integrity.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors