ABSTRACT
OBJECTIVE@#To investigate the effect of the chemoprotectant tempol on the anti-tumor activity of cisplatin (DDP).@*METHODS@#The cellular toxicity of tempol in human colon cancer SW480 cells and mouse colon cancer CT26 cells were evaluated using MTT and cell counting kit-8 assays. CalcuSyn software analysis was used to determine the interaction between tempol and DDP in inhibition of the cell viability. A subcutaneous homograft mouse model of colon cancer was established. The mice were randomly divided into control group, tempol group, cisplatin group and tempol + DDP treatment group with intraperitoneal injections of the indicated agents. The tumor size, body weight and lifespan of the mice were measured, and HE staining was used to analyze the cytotoxic effect of the agents on the kidney and liver. Immunohistochemistry and Western blotting were performed to detect the expression of Bax and Bcl2 in the tumor tissue, and TUNEL staining was used to analyze the tumor cell apoptosis. The level of reactive oxygen species (ROS) in the tumor tissue was determined using flow cytometry.@*RESULTS@#Tempol showed inhibitory effects on the viability of SW480 and CT26 cells. CalcuSyn software analysis showed that tempol had a synergistic anti-tumor effect with DDP (CI < 1). In the homograft mouse model, tempol treatment alone did not produce obvious anti-tumor effect. HE staining showed that the combined use of tempol and DDP alleviated DDP-induced fibrogenesis in the kidneys, but tempol also reduced the anti-tumor activity of DDP. Compared with the mice treated with DDP alone, the mice treated with both tempol and DDP had a significantly larger tumor size ( < 0.01) and a shorter lifespan ( < 0.05). Tempol significantly reversed DDP-induced expression of Bax and Bcl2 in the tumor tissue and tumor cell apoptosis ( < 0.001), and obviously reduced the elevation of ROS level in the tumor tissue induced by DDP treatment ( < 0.05).@*CONCLUSIONS@#Tempol can attenuate the anti-tumor effect of DDP while reducing the side effects of DDP. Caution must be taken and the risks and benefits should be carefully weighed when considering the use of tempol as an anti-oxidant to reduce the toxicities of DDP.
Subject(s)
Animals , Humans , Mice , Antineoplastic Agents , Antioxidants , Apoptosis , Cell Line, Tumor , Cell Proliferation , Cisplatin , Cyclic N-Oxides , Pharmacology , Drug Resistance, Neoplasm , Spin LabelsABSTRACT
Objective To comparatively analyze the SD rat chloasma model established by using the two methods of progesterone injection and ultraviolet radiation.Methods The rat chloasma model was established by adopting the high and low doses of progesterone injection and ultraviolet irradiation.The plaque area was observed and the skin section was observed by light microscope.The SOD and MDA levels closely related with chloasma melanin deposition were detected.Results The significant pigment deposition on the back skin in the high dose progesterone group was seen by naked eye and the scattered pigment deposition was seen in the low dose progesterone group;significant pigment deposition could be found in the ultraviolet group.Compared with the control group,the MDA level of various tissues in the high dose progesterone group was increased,while the SOD level was decreased,serum and skin SOD level in the low dose progesterone group was decreased,the difference was statistically significant(P＜0.05).Serum and skin SOD level in the high dose ultraviolet group was decreased,while the MDA level was increased,the skin SOD level in the low dose ultraviolet group was decreased(P＜0.05),but the difference between the two groups was not statistically significant (P＞0.05).The melanin grains were heaped up as the small black body under light microscope,which in the progesterone group showed the clutter distribution,the difference between the high dose group and low dose group was significant;which in the ultraviolet group showed the linear dense arrangement and the intergroup had no significant difference.Conclusion Progesterone injection and ultraviolet irradiation all can successfully establish the SD rat chloasma model,and the constructing model effect and stability of ultraviolet irradiation are better.
ABSTRACT
Objective To test the levels of enterovirus 71 (EV71) antibody among children of different ages in Shanghai in 2011,and to investigate the relationship between antibody levels and virus infection.Methods EV71 antibody was detected by microneutralization assay from the serum specimens of healthy children of different ages collected during July to August,2011.The results were analyzed by t test for quantitative data with normal distribution,and by x2 test for count data.Results The positive rate of EV71 antibody among the 93 serum specimens was 58.1％ (54/93).The geometric mean titer (GMT) of EV71-specific neutralizing antibody was 1 ∶ 14.48.The positive rate of EV71 antibody in infants less than 6 months old was 87.5％ (21/24),and the GMT was 1∶29.56.In children aged 2 to 3 years,the positive rate of EV71 antibody decreased to 3.7％ (1/27),and GMT decreased to 1∶4.21,which were both statistically significantly lower than those less than 6 months old (x2 =36.37,t=7.58; both P＜0.01).The positive rate of EV71 antibody increased to 83.3％ (20/24) in children aged 5 to 6 years,with GMT reaching 1∶21.74.Whereas in children aged 7 to 8 years,the positive rate was 66.7％ (12/18) and GMT was 1∶20.76,without statistically significant difference compared with those aged 5 to 6 years (x2 =1.58,t=0.597; both P＞0.05).No statistically significant difference was found between boys and girls in positive rate of EV71 antibody [62.7 ％ (32/51) vs 52.4 ％ (22/42),x2 =1.02,P＞0.05] or GMT (1 ∶ 16.23 vs 1 ∶ 12.61,t=0.881,P＞0.05).Conclusions Children aged 2 to 3 years were at higher risk for EV71 infection,with EV71 antibody level significantly lower than other age groups.
ABSTRACT
Objective To evaluate shell vials of MHV,a combination of Madin-Darby canine kidney cells (MDCK),human epidermoid cancer cells (Hep-2) and African green monkey kidney cells (Vero),and conventional cell culture in detecting influenza viruses and enterovirus from fresh clinical specimens.Methods Specimens from patients with influenza-like illness and children with hand-foot-mouth disease were inoculated with both shell vials of MHV and MDCK/Vero.Then cytopathological effect (CPE) was examined daily.Influenza viruses and enteroviruses were detected by multiple reverse transcriptase-polymerase chain reaction (mRT-PCR).Results CPE of MDCK/Vero cells were stronger than the shell vials of MHV.The isolation rate of influenza virus by MHV was 24.6％ (34/138) and that by MDCK was 28.3％ (39/138),which was not significantly different (x2 =1.92,P＞0.05).That of enterovirus by MHV was 28.1％ (9/32) and that by Vero was 37.5％ (12/32),which was not significantly different (x2 =3.00.P＞0.05).Conclusions CPE in MDCK/Vero cells are easier to be observed than the shell vials of MHV.However,the shell vials of MHV are appropriate in public health emergencies,which can be used for isolation of influenza viruses and enterovirus in patients with respiratory symptoms.
ABSTRACT
Objective To evaluate the survival ability of enterovirus 71 (EV71) on different surface and under different climate.Methods Each 1 × 105 tissue culture infective dose 50 (TCID50)EV71 was added on different aseptic surface of plastic,rubber,cloth and wood,respectively.Then these materials were put into biotron (artificial climatic chamber) which could simulate different temperature and moisture.The viruses were recovered after a definite time and then inoculated into Vero cell.The cytopathic effect (CPE) was observed everyday to survey the survival ability of EV71 on different medium surface.Results The recovery rates of EV71 on medium surface ranged from 89 ％-93 ％.The survival time of EV71 on medium surface varied under different climatic conditions.The longest survival time of the virus was observed under the condition of 20 ℃ as the temperature and 80％ as the humidity.After 24 hours of incubation,the infectious titer on plastic surface reduced about 4 lg.After 72 hours of incubation,the infectious titer reduced at least 3.89 lg on cloth and wood surface.Conclusions Temperature and humidity can affect the survival time of EV71 on medium surface,which is longer in the condition of low temperature and high humidity.The survival ability of EV71 on natural cloth and wood surface is better than that on synthetic plastic surface.
ABSTRACT
Objective To understand the genetic and antigenic variations of influenza A (H1N1) isolates in Shanghai area in winter of 2010.Methods A total of 137 throat swabs were collected from patients with influenza-like illness in the sentinel hospital in Shanghai area from December 2010 to January 2011,then inoculated into Madin-Darby canine kidney (MDCK) cells.The types of influenza were identified by direct immunofluorescence assay (DIF) and influenza A (H1N1) subtype was determined by reverse transcriptase-polymerase chain reaction (RT-PCR).The mutations of gene and amino acid locus were analyzed through the whole genome sequencing of hemagglutinin (HA),neuraminidase (NA) and polymerase (PB2) segments from some influenza A (H1N1) isolates.Results Total of 53 human influenza virus strains were isolated including 48 influenza A (H1N1) virus strains.Nineteen strains were selected for sequencing by simple random sampling.The phylogenetic tree of HA gene revealed that the latest isolates and most of influenza A (H1N1) viruses isolated before June 2010 were not in the same stem.Analysis of amino acid residues in HA protein showed that mutations were found in antigenic determinant region in some strains.Residues at the enzyme active sites of NA protein were strictly conservative,no change was observed in amino acid residues which were related to drug resistance against oseltamivir and zanamivir.The 627 and 701 residues in PB2 protein were glutamic acid and aspartic acid,respectively,which was still the feature of avian influenza virus,but E677G mutation was detected.Conclusion Compared to influenza A (H1N1) strains isolated in spring and summer,some variations have been detected in the strains isolated in Shanghai area in winter of 2010,some antigen drift and adaptive evolution in mammalian hosts have appeared.
ABSTRACT
Objective To establish a clinical test assay for detecting common respiratory viruses and enteroviruses (EV) by using mixed cultured Madin-Darby canine kidney cells (MDCK), human epidermoid cancer cells (Hep-2) and African green monkey kidney cells (Vero) to isolate common respiratory viruses and enteroviruses. Methods Throat swabs with influenza A and B viruses,adenovirus and EV71 were incubated with mixed cultured MDCK, Hep-2 and Vero in a single vial to observe the presence of cytopathic effects. Polymerase chain reaction (PCR), reverse transcription (RT)-PCR and monoclonal antibody-based immunofluorescene assay were also used for confirmatory test. Results The sensitive cell lines developed obvious cytopathic effects to the corresponding viruses, which were confirmed by the specific green particles observed by immunofluorescence assay and specific target PCR segments. Conclusions The shell-vial of mixed cells can simultaneously isolate different common respiratory viruses and EV. The isolated pathogens can be further confirmed by antigen test and PCR. This assay may improve the diagnosis of clinical viral diseases.
ABSTRACT
Objective To evaluate the survivability of hand foot mouth disease(HFMD)virus,in tap water for daily use.Methods HFMD viruses were isolated from cases of HFMD in Shanghai and Zhejiang from in 2008.Six isolated strains (five subtype of enterovirus 71 and one coxackie virus)were selected in this study.These viruses were mixed with chloride 1.0 mg/L tap-water and then inoculated into Vero cells.The cytopathic effect (CPE)was checked everyday in order to survey the survivability of each virus strain.The decline of virus survivability was analyzed by scatter diagram.Results These six strains of HMFD virus could survive longer than one month in tap water with initial chloride concentration of 1.0 mg/L and still had celluar infectivity.The survivabilities were varied between viruses isolated from different HFMD cases.Conclusions The survivabilities of enterovirus 71 and coxackie virus stains are quite strong in water.Therefore,the transmission route of water-borne pathogens should be monitored in regions using tap water during HFMD epidemic period.
ABSTRACT
Objective To study the gene characteristics of VP1 region of Enterovirus 71 (EV71) strains isolated from clinical specimens of children with hand-foot-and-mouth disease(HFMD) in Shanghai in 2010.MethodsEighteen EV71 isolates were selected from different periods of year 2010,including strains isolated from fatal cases and non-fatal cases.Complete VP1 gene (891nucleotides) of the eighteen EV71 isolates were amplified and sequenced,and then compared with that of genotype A,B,C reference EV71 strains in GeneBank by homogeneity and phylogenetic tree analyses.ResultsThe nucleotide homogeneities between these 18 Shanghai strains and the representative isolates of genotype A and B were 81.5 ％ -82.6 ％ and 83.4 ％- 84.2 ％,respectively,while the amino acid homogeneities were 94.3 ％- 95.0％ and 96.6％ -97.0％,respectively.The nucleotide and amino acid homogeneities between the 18 Shanghai strains and the representative isolates of genotype C were 87.4％- 99.2％ and 98.7％ -100.0％,respectively.Of note,the nucleotide and amino acid homogeneities between Shanghai strains and Fuyang EV71strains (representative strain of C4 subtype) appeared to be 97.8％- 99.2％ and 99.3％- 100.0％,respectively.The eighteen EV71 Shanghai strains were classified as genotype C,subgenogroup C4 in the phylogenetic tree.There was no remarkable difference in VP1 gene between the strains isolated from fatal cases and non-fatal cases.ConclusionThe EV71 strains isolated from Shanghai belong to subgenogroup C4.