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Objective To analyze result of the external quality assessment for laboratories of toxicological pathology diagnosis in organizations in China. Methods A total of 86 organizations that participated in the 2020-2021 external quality assessment in laboratory of toxicological pathology diagnosis (hereinafter referred to as "reference units") were selected as research subjects using convenient sampling method, and the assessment results were analyzed. Results The median of total score was 92, and the 0-100 percentiles were 64-100 in these 86 reference units. Among these reference units, 76 were rated as excellent, 10 as qualified, with the excellent and the qualified rate of 88.4% and 11.6%, respectively. No reference unit was rated as unqualified. The rates of excellence of the reference units in public health institutions, pharmaceutical research institutions, drug safety evaluation centers and testing companies were 95.7%, 84.2%, 85.7% and 86.7%, and the qualified rates were 4.3%, 15.8%, 14.3% and 13.3%, respectively. The distribution of excellence and qualification among the four types of reference units showed no statistical difference (P>0.05). The distribution of sample scores according to the three grades of poor, good, and excellent were 4.9%, 20.7%, and 74.5% in public health institutions, 8.6%, 23.7%, and 67.8% in pharmaceutical research institutions, 12.5%, 25.0%, and 62.5% in drug safety evaluation centers, and 5.4%, 17.5%, and 77.1% in testing companies. The proportion of excellence unit in public health institutions was higher than that in pharmaceutical research institutions (P<0.05). Conclusion The overall toxicological pathology diagnostic capabilities in China are good, and various types of reference units demonstrate comparable technical capabilities. However, there is a need for standardization of diagnostic terminology.
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The extraordinary advantages associated with mRNA vaccines, including their high efficiency, relatively low severity of side effects, and ease of manufacture, have enabled them to be a promising immunotherapy approach against various infectious diseases and cancers. Nevertheless, most mRNA delivery carriers have many disadvantages, such as high toxicity, poor biocompatibility, and low efficiency in vivo, which have hindered the widespread use of mRNA vaccines. To further characterize and solve these problems and develop a new type of safe and efficient mRNA delivery carrier, a negatively charged SA@DOTAP-mRNA nanovaccine was prepared in this study by coating DOTAP-mRNA with the natural anionic polymer sodium alginate (SA). Intriguingly, the transfection efficiency of SA@DOTAP-mRNA was significantly higher than that of DOTAP-mRNA, which was not due to the increase in cellular uptake but was associated with changes in the endocytosis pathway and the strong lysosome escape ability of SA@DOTAP-mRNA. In addition, we found that SA significantly increased the expression of LUC-mRNA in mice and achieved certain spleen targeting. Finally, we confirmed that SA@DOTAP-mRNA had a stronger antigen-presenting ability in E. G7-OVA tumor-bearing mice, dramatically inducing the proliferation of OVA-specific CLTs and ameliorating the antitumor effect. Therefore, we firmly believe that the coating strategy applied to cationic liposome/mRNA complexes is of potential research value in the field of mRNA delivery and has promising clinical application prospects.
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OBJECTIVE: To observe the pathological changes of rat silicosis model at different time points. METHODS: The specific pathogen free SD rats were randomly divided into control group and 7, 15, 21, 30, 45, 60, 75 and 90 day model groups based on their body weight, with 5 rats in each group. Non-exposed endotracheal intubation was performed. Silicosis rat model was established by intratracheal instillation of 250 g/L silica suspension in each rat, and 0.9% sodium chloride solution was perfused into the trachea of rats in the control group. The rats in the control group were sacrificed on the 90 th day after exposure, and the model rats in the other 8 groups were sacrificed on the 7 th, 15 th, 21 st, 30 th, 45 th, 60 th, 75 th and 90 th days after the end of exposure. The gross appearance of the lung tissue of rats was observed. The rat lung tissues were stained with hematoxylin-eosin and Masson staining to observe the pathological changes, and Ashcroft score was evaluated. RESULTS: The gross observation showed that the lungs of rats in the model groups had varying degree of gray changes, hardened texture, and spots and nodules on the surface of the lobes. These changes were aggravated with the increase of time after dust exposure. The results of histopathological examination of the lungs showed that the rats developed acute alveolar inflammation, and a large number of macrophages and neutrophils were seen in the lung tissues in the 7 th and 15 th day model groups. Cellular nodules appeared in the lung tissue, and fibrosis appeared in the center of the nodule in the rats of 21 st, 30 th, and the 45 th day model groups; the silicosis nodules appeared in the lung tissues of rats in the 60 th, 75 th, and 90 th day model groups, and the small nodules gradually merged into larger ones. Simultaneously, with the increase of time after dust exposure, the lung tissue of rats gradually showed severe pulmonary fibrosis. The lung organ coefficient and Aschcroft score of rats increased with the increase of time after dust exposure(P<0.01). CONCLUSION: The rat lung changes after dust exposure. Acute alveolar inflammation occurs on the 7 th to 15 th day after dust exposure; cellular nodules develop on the 21 st to 45 th day after dust exposure; silicosis nodules develop on the 60 th to 90 th day after dust exposure. The severity of lung fibrosis after dust exposure showed a time-effect relationship in rats.
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OBJECTIVE: To investigate the chronic toxicity and carcinogenicity of kresoxim-methyl in rats. METHODS: Specific pathogen free SD rats were randomly divided into control group and low-, medium-and high-dose groups according to the body weight of rats, 120 rats in each group with half male and half female rats. The chronic toxicity and carcinogenesis was induced in rats for 104 weeks by oral feeding. The dose of kresoxim-methyl in feed of male and female rats was 0, 75, 300 and 1 200 mg/kg. During the process of experiment, the body weight of rats was weighed. The blood biochemistry, organ coefficient and histopathology were examined at the end of the exposure, and the tumor incidence was calculated. RESULTS: There was no significant difference in mortality of the female or male rats in the four groups(P>0.05). At the 32 nd, 48 th and 56 th week after exposure, the body mass of female rats in the high dose group was lower than that in control group(P<0.05); at the 8 th, 16 th, 24 th and 32 nd week, the body mass of male rats in the high dose group was lower than that in the control group(P<0.05). The organ coefficients of heart and adrenal gland of female rats in the high dose group were higher than those in the control group and the low dose group(P<0.05). The organ coefficient of liver of male rats in the high dose group was lower than that in the control group(P<0.05). The alkaline phosphatase of male rats in the three dose groups was lower than that in the control group(P<0.05). The blood glucose of male rats in the high dose group was higher than that in the control group(P<0.05). The aspartate aminotransferase of male rats in the high dose group was lower than that in the control group(P<0.05). There was no significant difference among the three indexes in female rats(P>0.05). The tumor incidence of the control group and the low, medium and high dose groups were 68.3%, 75.0%, 75.0% and 78.8%, respectively, with no significant difference(P>0.05). The tumor incidence of the female rats was higher than that of the male rats(87.0% vs 61.5%,P<0.01).The tumor multiplicity of the above four groups were 38.3%, 35.8%, 35.0%, 39.8%, respectively, with no significant difference(P>0.05). The tumor multiplicity in female rats was higher than that in male rats(56.9% vs 17.6%,P<0.01). CONCLUSION: The no observed adverse effect level of kresoxim-methyl to female and male SD rats was 24.726 and 20.002 mg/(kg·d), respectively. No carcinogenicity of kresoxim-methyl to SD rats was observed.
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OBJECTIVE: To evaluate the diagnostic ability of toxicity pathology in patho-toxicological testing institutions in China. METHODS: The institutions participated in the 2018 Interlaboratory Comparison Activity of Toxicity Pathology Testing(hereinafter referred to as reference unit) were selected as the research subjects. The heart, spleen, skin, soft tissue, liver and mammary gland of SD rats of different groups in the 2-year carcinogenesis test were selected. The femur, knee joint and nose of Beagle dogs in the 4-week toxicity test and a total of 10 pathological tissues were selected as the comparison samples. The pathological diagnosis was carried out by the pathological diagnostic personnel of the reference unit, and the diagnostic results were reported. The expert appointed by the Toxicology and Pathology Committee of Chinese Toxicology Association compared the diagnostic results with the appointed value. RESULTS: A total of 167 pathological diagnostic personnel from 75 reference units in 24 provinces and municipalities participated in the comparison activity. The reference units were mainly distributed in East China, South China and North China, accounting for 77.3%(58/75). Totally 75 reference units fed back 750 effective diagnostic results. The qualified rates of diagnosis on heart, spleen, skin, soft tissue and breast samples were higher than 60.0%. The qualified rates of diagnosis on femur and knee joint, and nose samples were low(30.7% and 6.7%, respectively). There were 1(1.3%), 46(61.4%) and 28(37.3%) reference units rated as unqualified, qualified and excellent, respectively. CONCLUSION: Most of the testing institutions in China have a high level of patho-toxicological diagnostic ability, that can provide reliable diagnostic results for toxicology safety evaluation tests.
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OBJECTIVE: To observe the sub-acute toxicity of 1-bromopropane(1-BP) oral exposure for 28 days in SD rats. METHODS: Specific pathogen free adult female SD rats were randomly assigned to the control and exposed group, 8 rats in each group. The 1-BP was suspended in corn oil and administered by gavages in a dose of 800 mg/kg body weight to rats in the exposed group, once a day, 5 days per week for 4 weeks. The rats in the control group were given equal volume of corn oil. After the last exposure, blood and urine of rats were collected for 1-BP level detection and hematological examination. Brain, heart, lung, liver, kidney and spleen of rats were collected for gross pathological examination and histopathological examination. RESULTS: The rats of exposed group showed unstable standing, weakness of hind limbs, limping and lying down from the 3 rd week of exposure. From the 1 st to 4 th week of exposure, mean body weight of rats in the exposed group were significantly lower than those of the control group(P<0.05). In the exposed group, the level of 1-BP in urine was higher than that in blood(P<0.05), and that there was positive correlation between them(Spearman correlation coefficient=0.954, P<0.01). In the control group, 1-BP was not detected. The absolute weights of brain and lung tissue in the exposure group decreased(P<0.05), meanwhile the organ coefficients of heart, liver, spleen and kidney were significantly increased compared with the control group(P<0.05). The number of red blood cells, hemoglobin concentration, hematocrit, the mean hemoglobin concentration, the total serum cholesterol and triglycerides were decreased(P<0.05). No pathological change related to 1-BP exposure was observed in the main organs of the rats in the exposed group. CONCLUSION: The sub-acute oral toxicity of 1-BP is mainly neurotoxicity and hematotoxicity. The 1-BP level in urine may reflect its exposure.
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Objective To develop an ideal hypertension combined hyperlipidemia(HP/HL)rat model by feeding spontaneously hypertensive rats(SHRs)with high fat diet, and to evaluate the pathological changes in target organs including heart and kidney. Methods Twenty 3-week old male SHRs were randomly divided into two groups: normal fat control group(SHR-NC)and high fat group(SHR-HF). Moreover,ten 3-week old male Wistar-Kyoto rats(WKY)were taken as the model control group(WKY-NC). The rats in SHR-HF group were fed with high-fat diet to induce HP/HL, while rats of WKY-NC and SHR-NC groups were fed with normal diet. The systolic blood pressure(SBP)and body weight were measured every week. At the end of the experiment, the rats were sacrificed to take serum samples for blood lipid analysis including high density lipoprotein(HDL-C), low density lipoprotein(LDL-C), total cholesterol(TC)and triglyceride(TG). Heart and kidney tissue samples were collected to examine the pathological changes using HE and Masson staining. Results Compared with the SHR-NC group, the SHRs fed with high-fat diet for 23 weeks presented significant increase of blood pressure and TC, TG, LDL-C, and decrease of HDL-C. The HP/HL rat model showed pathological changes in the HP/HL target organs, heart and kidney. Renal tissues were severely damaged and showed a large area of fibrosis. Besides, left ventricular hypertrophy and myocardial fibrosis were also observed. Conclusions A HP/HL rat model is successfully constructed by feeding SHRs with high-fat diet for 23 weeks. Most importantly,this model exhibits progressive renal and cardiac alterations, similar to those of patients with HP/HL. This HP/HL rat model may become widely used for evaluation of HP/HL therapeutic drugs.
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OBJECTIVE: To explore the effects of sub-acute inhalation of 1-bromopropane( 1-BP) on the ultrastructure of cerebral cortex,hippocampus,cerebellum,and brainstem in male rats. METHODS: Specific pathogen free healthy male Wistar rats were randomly divided into control group and exposure group with 6 rats in each group. The rats of exposure group received 1-BP vapor at a concentration of 5 000 mg/m3. The rats in the control group were given fresh air in a dynamic inhalation chamber system for 4 weeks(6 hours/day,5 days/week). After the end of the exposure,the cerebral cortex,hippocampus,cerebellum and brainstem of rats were collected and the ultrastructural changes were observed under transmission electron microscope( TEM). RESULTS: After 3 weeks of exposure to 1-BP,the rats in the exposure group began to have unresponsiveness and decreased muscle strength in hind limbs. The body weight of exposure group was lower than that of control group from the 1 st to the 4 th week( P < 0. 05). TEM results showed destroyed structure of the myelin sheath in the region of cerebral cortex, hippocampus, cerebellum and brainstem, and irregular nucleus, vacuolar degeneration,increased lysosome of endoplasmic reticulum,mitochondrion swelling of neuron cells,karyopyknosis of astrocytes and vacuolation in the neurite of astrocytes located in the blood brain barrier( BBB). CONCLUSION: 1-BP sub-acute inhalation exposure could damage the myelin,neuron,astrocyte and BBB in male rats. The demyelination of nerve fiber and decreased permeability of BBB was particularly noticeable.
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OBJECTIVE: To observe the diagnostic capacity and its influencing factors in the toxicologic pathology diagnostic laboratories in China. METHODS: Inter-laboratory comparison of toxicologic pathology diagnosis was cosponsored by Chinese Society of Toxicology-Toxicologic Pathology Specialty Section and Guangdong Province Hospital for Occupational Disease Prevention and Treatment. Nine digital slices of digestive system lesions were screened as comparison samples,and the reference institution with toxicologic pathology diagnostic laboratories completed the diagnosis within the prescribed time. According to the three grades of “excellent”,“satisfaction”and “dissatisfaction”,the evaluation was carried out.RESULTS: A total of 74 reference institution participated in this comparison,which distributed in 20 provinces and 4 municipalities and 156 pathologists. The reference institutions were mainly distributed in North China,Southern China and East China. There was an average of 2 pathologists per laboratory,and in the quantity of academic title,the junior,intermediate,and senior was 15,70 and 46 persons respectively. Parasitic hepatocyte cysts( 97. 3%),adenocarcinoma of small intestine( 95. 9%) and polyarteritis nodosa of the pancreas( 89. 2%) had the highest rate of “excellent”grade,while the duodenal gland inflammation( 67. 6%),foam cell aggregation in colonic propria( 40. 5%) and hepatoma adenoma( 32. 4%) had the highest rate of dissatisfaction grade in the evaluation of single case. In the overall evaluation,reference laboratories reached the “excellent”grade and the “satisfaction”grade were 78. 4% and 21. 6% respectively.The number of pathologists provided by each reference laboratory had impacts on the overall evaluation level and the single case evaluation( neoplastic lesions) in the evaluation of single case( P < 0. 05). The types of the reference laboratory,the regional distribution and the grade of the academic title had no effect on the diagnostic ability( P > 0. 05). CONCLUSION: The reference laboratory is superior in diagnosing the digestive system lesions in the inter-laboratory comparison activity.The number of pathologists in the reference laboratory is one of the influencing factors of its diagnostic ability.
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OBJECTIVE: To observe the effects of bone marrow mesenchymal stem cells( BMSCs) on the treatment of pulmonary fibrosis in silicosis mice. METHODS: Specific pathogen free healthy male C57BL/6 mice were randomly divided into control group,silicosis group and treatment group with 10 mice in each group. The mice of the control group were given one intra-tracheal injection of 20. 0 μL 0. 90% sodium chloride solution. The silicosis group and treatment group received one 20. 0 μL( mass concentration 250 g/L) of silica dust suspension. After 4 weeks,mice in treatment group were injected with 250. 0 μL of BMSCs suspension( cell density 2 × 10~9/L) by tail vein and silicosis group injected with 250. 0 μL of 0. 90% sodium chloride solution instead,once a week with continuous treatment for 4 weeks. Control group was not given any treatment. Mice were euthanized two weeks after the last treatment. Pathological sections were observed,pulmonary fibrosis score( Ashcroft scores) was marked. Lung coefficient was measured. Lung tissue hydroxyproline( HYP) level and serum transforming growth factor β1( TGF-β1) level were measured. The level of pulmonary fibrosis was scored and the percentages of T helper cell 17( Th17 cell) and regulatory T cell( Treg cell) of spleen and hilar lymph node( HLN) were measured by flow cytometry. RESULTS: The results of lung histopathological examination showed that the pulmonary fibrosis was severe in silicosis group. Massive collagen fiber accumulation and silicotic nodule were found. In treatment group,fibrosis was mild,little collagen fiber accumulation and silicotic nodule were found. The lung coefficient,Aschcroft scores,lung tissue HYP level,serum TGF-β level and the percentage of Th17 cell of spleen and HLN in silicosis group were higher than that of control group( P < 0. 05),while the above indexes of treatment group were lower than that of silicosis group( P < 0. 01). The percentage of Treg cell of spleen and HLN in silicosis group were lower than that of control group( P < 0. 05),while those indexes of treatment group were higher than that of silicosis group( P < 0. 01).CONCLUSION: BMSCs could effectively alleviate the pulmonary fibrosis in silicosis mice and correct the imbalance of Th17/Treg.
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OBJECTIVE: To explore the repair effects of bone marrow mesenchymal stem cells( BMSCs) on hematopoietic injury induced by benzene poisoning in mice. METHODS: Five specific pathogen free healthy male Kunming mice were selected to obtain BMSCs through bone marrow attachment culturing method. The Kunming mice were randomly divided into poisoning group and BMSCs transplantation group,18 mice in each group,after the benzene poisoning model was established by subcutaneous multi-point injection of benzene and oil mixture 3 times/week,10 weeks continuously. Each group was injected through tail vein with 250. 0 μL 0. 9% sodium chloride solution or 250. 0 μL BMSCs suspension( cell density 2 × 109/L) once per week for 4 weeks,respectively. The control group( 10 mice) was not given any treatment.Mice were euthanized 2 weeks after treatment. The blood routine examination was conducted. Nucleated cells in bone marrow were observed after Giemsa staining. The clones of hemopoietic progenitor cells were counted and the levels of serum interferon-γ( IFN-γ) were examined using enzyme-linked immune sorbent assay. RESULTS: The mouse model of chronic benzene poisoning was established successfully. After the BMSCs transplantation treatment,the white blood cell count,platelet count,red blood cell count,hemoglobin level and bone marrow nucleated cell as well as granulocyte-macrophage colony forming unit( CFU-GM) in benzene poisoning group were significantly decreased compared with control group( P <0. 01),while those indexes of BMSCs treatment group were higher than that of benzene poisoning group( P < 0. 05). The counts of platelet,red blood cell,bone marrow nucleated cell and CFU-GM in BMSCs treatment group were significantly lower than that of control group( P < 0. 05). The level of serum IFN-γ in benzene poisoning group was higher than that of control group( P < 0. 01),and serum IFN-γ level in BMSCs treatment group was lower than that of benzene poisoning group( P < 0. 01). There was no significant difference of IFN-γ level in BMSCs treatment group compared with control group( P > 0. 05). CONCLUSION: BMSCs have repair effects on hematopoietic system injury caused by benzene poisoning.
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OBJECTIVE: To explore the spontaneous non-tumor lesion of kidney and its correlation with different age and sex in SD rats. METHODS: Eight hundred specific pathogen free SD rats were collected from the blank control groups used in subacute toxicity tests,subchronic toxicity tests and 1 or 2 years of chronic toxicity combined with carcinogenic tests. Rats were randomly divided into 4 groups with 10,19,56 or 108 weeks of experimental periods. Each group consisted of 100 female and 100 male rats. The renal tissues were collected at the end of each experiment,and the renal organ coefficients were calculated. The pathological non-tumor changes of the kidneys were analyzed. RESULTS: The renal organ coefficients in female rats at the age of 56 and 108 weeks were both lower than that of 10 and 19 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 56 weeks was lower than that of 10 and 19 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 108 weeks was higher than that of 56 weeks( P < 0. 008). The renal organ coefficient of male rats at the age of 108 weeks was higher than that of female rats of 108 weeks( P < 0. 008). The incidence of renal tubular calcium salt deposition,interstitial inflammatory cell infiltration and renal tubular dilatation in the female rats at the age of 108 weeks were higher than those in the male rats at the age of 108 weeks( P < 0. 05). The chronic progressive nephropathy incidence of female rats at the age of 108 weeks was lower than that of male rats aged 108 weeks( P < 0. 01).The renal tubular calcium salt deposition incidence of female rats aged 56 weeks was higher than that of male rats aged 56weeks( P < 0. 01). CONCLUSION: The spontaneous non-tumor lesions in the kidney of SD rats were common. The incidence of some lesions was different in the same age group with different sex.
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OBJECTIVE: To explore the feasibility of dynamic observation and measurement of living silicosis rat model by using small animal positron emission tomography( PET)-computed tomography( CT). METHODS: Specific pathogens free SD rats were divided into model group and control group. The silicosis rat model was established by one-time endotracheal injection of 30 g/L silica suspension,while the control group rats were injected of isopyknic 0. 9% sodium chloride solution. Six rats from each group were randomly selected for CT scan from 1st,2nd,3rd,4th,6th,8th and 12 th week after silica injection using the small animal PET-CT. CT value and standardized uptake value( SUV) of18F-fluorodeoxyglucose were measured. Lung tissue was collected for pathological sections. The levels of hydroxyproline( HYP) of lung tissue and serum transforming growth factor β1( TGF-β1) and interleukin-1( IL-1) were measured.RESULTS: Pathological sections of rats of model group showed inflammatory exudation,inflammation reduced and fibrosis increased with extended time. The results are identical with findings in PET-CT. Lung SUV of rats in model group in the1st-3rd weeks were higher than that in control group in the same time point( P < 0. 05) and decreased by the increasing time during the 1st-4 th weeks of dust injection( P < 0. 05). Lung CT values of model group in the 1st-12 th weeks were higher than that of control group in the same 7 time points( P < 0. 05) and decreased in the 1st-6th weeks and then increased in the 6th-12th weeks by the increasing time of dust injection( P < 0. 05). Lung coefficients and HYP levels of model group in the 7 time points were higher than that of control group in the same 7 time points( P < 0. 05). Lung coefficients decreased in 1st-4th weeks and lung HYP levels increased in 6th-12th weeks with the increasing time of dust injection( P < 0. 05). Excepted of the 3rd and 4th weeks,serum TGF-β1 levels of model group in other 5 time-points were higher than that of control group in the same 5 time points( P < 0. 05) and decreased in the 1st-4th weeks( P < 0. 05)then increased in the 4th-8th weeks( P < 0. 05) by the increasing time of dust injection. Serum IL-1 levels of model group in the 1st-4th weeks were higher than that of control group in the same 4 time points( P < 0. 05) and decreased by the increasing time of dust injection( P < 0. 05) and decreased by the increasing time of dust injection( P < 0. 05).CONCLUSION: Early inflammation and terminal fibrosis of living silicosis rat model could be observed effectively by small animal PET-CT,which can be used as a new approach for dynamic tracing silicosis in rat models.
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OBJECTIVE: To explore the effect of 1,2-dichloroethane(1,2-DCE) induced apoptosis on the expression of related proteins in human neuroblastoma cells(SH-SY5 Y cells). METHODS: SH-SY5 Y cells were cultured in complete medium with 1,2-DCE at final concentrations of 0,10,20,30,40,50,60,70 and 80 mmol/L. After being cultured for24 hours,the apoptosis of SH-SY5 Y cells was tested by flow cytometry using annexin Ⅴ-fluorescein isothiocyanate and propidium iodide. Western blot was used to detect the protein expression of P53,B cell lymphoma/leukmia-2(BCL-2)and BCL-2 associated X protein(BAX). RESULTS: At 1,2-DCE concentrations of 0-80 mmol/L,the total apoptosis rate of SH-SY5 Y cells increased with 1,2-DCE concentrations in a dose-dependent manner(P < 0. 01). At 1,2-DCE concentrations of 30-80 mmol/L,the early apoptosis rate and total apoptosis rate of SH-SY5 Y cells increased significantly than the control group(P < 0. 05). Compared with the other groups,the protein expression of P53 was the lowest when the1,2-DCE concentration was 20 mmol/L(P < 0. 05),and the protein expression of BCL-2 and the BCL-2/BAX ratio were the lowest when the 1,2-DCE concentration was 70 mmol/L(P < 0. 05). There is no dose-response relationship in the1,2-DCE concentrations and the protein expression levels of P53,BCL-2 and BAX,and BCL-2/BAX ratio. Linear multiple regression analysis revealed that the total apoptosis rate of SH-SY5 Y cells treated with 1,2-DCE was associated with the protein expression of P53 and BCL-2,and BCL-2/BAX ratio(P < 0. 05). CONCLUSION: 1,2-DCE could inhibit the apoptosis of SH-SY5 Y cells. The mechanisms may be related to the changes of P53 and BCL-2 protein expression,and BCL-2/BAX relative amount.
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OBJECTIVE: To explore the non-neoplastic hepatic lesions in SD rats at different ages. METHODS: The specificpathogen free SD rats were collected from the blank control groups used in subacute toxicity tests,subchronic toxicity tests and chronic toxicity combined with carcinogenic tests for safety evaluation. At the end of each experiment,i. e. week 10,19,56 and 108(assigned into four groups: 10,19,56 and 108 weeks,each contained 100 rats with each sex),rats were executed. The liver organ coefficient was calculated,the pathological examination was performed,and the non-tumorous lesions in the liver were analyzed. RESULTS: The liver organ coefficients at the age of 19,56,108 weeks were lower than that of 10 weeks(P < 0. 05); those at the age of 56 and 108 weeks were lower than that of 19 weeks(P < 0. 05),and that of 108 weeks was greater than of 56 weeks(P < 0. 05). Among the 10-week-old,19-week-old,56-week-old and 108-week-old groups,the types of non-neoplastic hepatic lesions detected in the female rats were 6,6,13 and 15 respectively,meanwhile those in the male rats were 6,6,13 and 15 respectively. Both male and female rats,the incidences of hepatocyte fatty degeneration,edema and hepatic infiltration of inflammatory cells were significantly increased with the increase of age in each group(P < 0. 05). The incidences of intrahepatic bile duct proliferation and intrahepatic bile duct fibrosis in rats at the age of 56 and 108 weeks were higher than those at the age of 10 and 19 weeks(P < 0. 008).Moreover,the frequency of hepatic sinus expansion lesions in rats at the age of 108 weeks was higher than those of 19 weeks(P < 0. 008). CONCLUSION: Spontaneous non-neoplastic lesions in the liver of SD rats were common,primarily demonstrated as hepatocyte fatty degeneration,edema and infiltration of inflammatory cells. The incidences of lesions increased with the increase of age.
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OBJECTIVE: To explore the immune cytotoxicity effect and its mechanism of trichloroethylene( TCE) on activated human T cells. METHODS: a) Different concentrations of TCE( 0. 32,0. 63,1. 25,2. 50,5. 00,10. 00 mmol / L)were used to treat activated T cells [activated with cluster of differentiation( CD) 3 and CD28] respectively. Dimethyl sulfoxide( DMSO) was used in the solvent group and the control group used no TCE or DMSO. The survival rate of activated T cells was calculated using CCK-8 assay after being cultured for 24 hours. b) Different concentrations of TCE( 0. 00,2. 50,5. 00 mmol/L) were used to treat activated T cells. The apoptosis of cells was detected using flow cytometry. c) Different concentrations of TCE( 0. 00,0. 32,0. 63,1. 25,2. 50,5. 00 mmol / L) were used to treat activated T cells and the level of cytokines as interleukin( IL)-2 and IL-6 in cell culture supernatant was detected using enzyme linked immunosorbent assay after culturing for 24 hours. d) The control group and TCE treatment group of activated T cells were treated with 0. 00 and 5. 00 mmol / L TCE respectively. Cells were collected after culturing 0,30,60 and 120 minutes. Western Blot was used to detect the protein expression of signal transducers and activators of transcription3( STAT3) and phospho-STAT3( p-STAT3). RESULTS: a) After 24-hour-exposure to TCE,the activated T cell survival rate of 10. 00 mmol / L TCE treatment group were significantly lower than that in the control group and DMSO group( P <0. 05). b) There were no significant differences in cell apoptosis of activated T cells after treatment with 0. 00,2. 50 and5. 00 mmol / L TCE( P > 0. 05). c) In groups treated with different concentrations of TCE( 0. 32,0. 63,1. 25,2. 50,5. 00 mmol / L),the level of IL-2 and IL-6 in the cell culture supernatant of activated T cells were significantly higher than that in the control group( P < 0. 05). With the increasing of TCE exposure doses,the levels of IL-2 and IL-6 significantly increased( P < 0. 01) with dose-effect relationship. Compared with the control group,the levels of IL-17 A,interferongamma and transforming growth factor-beta in cell culture supernatant of activated T cells of the TCE treatment groups were no significant differences( P > 0. 05). d) The expression of p-STAT3 protein was low in the control group at different times. The expression of p-STAT3 protein in TCE treatment group was low at 0 minute,but increased at 30,60,120 minutes. The expression of p-STAT3 protein in TCE treatment group was higher than that in the control group at different time points. The levels of STAT3 total protein in TCE treatment group and the control group were similar at different time points,and were higher than the p-STAT3 proteins. CONCLUSION: TCE at 5. 00 mmol / L had no observed toxic effect on activated T cells. High doses of TCE( ≥10. 00 mmol / L) showed cytotoxic damages to activated T cells,and low doses of TCE( ≤5. 00 mmol / L) could stimulate activated T cells to secrete IL-2 and IL-6. Treatment of TCE at 5. 00 mmol / L on activated T cells could up-regulated the level of p-STAT3.
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The rural health service is the important part of China’s health initiative and improving the rural grass-root health technical capabilities and service level marks the strategic initiatives and present needs to promote the rural health service development. The Traditional Chinese Medicine ( TCM) has a broad and solid mass base in rural areas and concentrating on the promotion of the TCM’s appropriate technologies constitutes an important way to strive for the rural health services development. Gangu and Jingning Counties of the Gansu province fully use the Health XI Project platform to promote the TCM’s appropriate technology application and explore the service model. With the achieved good experiment results, effective development of the TCM services is promoted.
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ObjectiveTocomparethedifferencesoftwostocksofguineapigs,thealbinoguineapigsandpigment guinea pigs , in establishing dyslipidemic model , to evaluate their lipid-lowering action , and to compare their properties for development of hyperlipidemia .Methods Two stocks of the 5-week-old guinea pigs were randomly divided into two groups, normal group (NC) and model group (Model).For the NC group, 12 guinea pigs were fed with normal chew .For the model group , after fed with high-fat diet for four weeks , 24 male guinea pigs were randomly grouped and treated with vehicle (VC group) and pitavastatin (Pit group) calcium, respectively, by gavage as well as received high-fat diet.Before and after modeling and pitavastatin treatment , blood samples were collected and subjected to analysis of plasma TC , TG, HDL-C and LDL-C, respectively .Results In the normal group , the blood lipid levels of albino guinea pigs were more stable than that of the pigmented pigs with the increase of age .After fed with high-fat diet , the plasma lipid levels of TC , TG and LDL-C were significantly increased in the two strains of guinea pigs , while HDL-C showed a decrease to varying degrees .Interestingly , the lipid level in the albino guinea pigs was significantly higher than that of pigment guinea pigs . And also, after drug administration for four weeks , pitavastatin treatment significantly decreased the elevated lipid level of TC, TG and LDL-C in the albino guinea pigs compared with that in the pigment guinea pigs .Conclusions The albino guinea pigs and pigment guinea pigs demonstrate certain differences in establishing dyslipidemic model and evaluating lipid -lowering pharmacodynamics .However , compared with the pigment guinea pigs , the albino guinea pigs have obvious superiority because of easy establishment of hyperlipidemia model and are more sensitive to lipid -lowering drugs .
ABSTRACT
Bovine serum albumin nanoparticles(BSANP) were prepared by desolvation method. The activated folic acid (N-hydroxysuccinimide ester of folic acid) was conjuated to the surface of BSANP via the amino groups. Then the folate-conjugated BSANPs (folate-BSANP) were purified with Sephadex G-50 column and completely separated from unreacted folic acid. After chymotryptic hydrolysis, the extent of folate conjugation on the BSANP was determined by quantitative ultraviolet(UV) spectrophotometric analysis. It was found that the spectrum of trypsin digest of folate-conjugate BSANP is basically identical with that of folate, thus indicating folate is successfully expressed on the surface of BSANP. The folate-BSANP was averagely 66 nm in diameter and was spherical in shape. Folate-conjugated BSANP was achieved, which represents a potential new drug carrier for tumor cell-selective targeting.