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Background In recent years gut microbiota has been found to play an important role in the occurrence and development of various chronic diseases, and diet is an important factor influencing gut microbiota. However, the effects of maternal high-fat diet in pre-pregnancy and pregnancy-and-lactation periods on offspring gut microbiota are still unclear. Objective To investigate the effects of maternal high-fat diet in pre-pregnancy and pregnancy-and-lactation periods on gut microbiota of offspring mice. Methods C57BL/6J female mice were divided into four groups according to the diet patterns (high-fat diet, HFD; control diet, CD) given before and after conception, namely the pre-pregnancy control diet and post-pregnancy control diet group (CD-CD group), the pre-pregnancy control diet and post-pregnancy high-fat diet group (CD-HFD group), the pre-pregnancy high-fat diet and post-pregnancy control diet group (HFD-CD group), and the pre-pregnancy high-fact diet and post-pregnancy high-fat diet group (HFD-HFD group). Female mice were conceived in the same cage with male mice after 6 weeks of feeding, and the successfully conceived females continued to be randomly divided into two groups receiving either high-fat or control diet, and when the offspring mice were born, they were breastfed directly by the mothers, with each mother nursing only one offspring mouse. The number of offspring mice in each group was 6, with half males and half females. The body weight of offspring mice were recorded and body weight gain was compared between the four groups. After the lactational period, fresh feces of the offspring were collected, and the fecal DNA was extracted. Specific primers were designed according to the bacterial 16S rDNA(V3+V4) sequence and then the sequencing was performed using the Illumina HiSeq 2500 platform. Species annotation and operational taxonomic unit (OTU) analysis of sequencing data were conducted using QIMME, USEARCH and R software. In alpha diversity analysis, ACE and Chao1 indices were used to evaluate species richness, Shannon and Simpson indices considered both species richness and evenness. In beta diversity analysis, principal coordinates analysis (PCoA) and analysis of similarities (Anosim analyses) were used to find the differences in composition of gut microbiota between four groups, and line discriminant analysis effect size (LefSe) was conducted to identify which specific taxa contributed to the significant differences between groups. Results A greater effect of post-pregnancy diet on offspring body weight was observed, and the lowest body weight was recorded in the HFD-CD group during the whole experimental period. The results of OTU analysis showed that high-fat diet during post-pregnancy period reduced the number of OTUs in offspring mice, and the results of alpha diversity analysis showed that high-fat diet during post-pregnancy period reduced the richness of intestinal flora (ACE, P<0.05; Chao1, P<0.05), whereas differences in the α-diversity indices did not show statistical significance in the offspring mice with pre-pregnancy high-fat diet. The high-fat diet at different periods also led to changes in the dominant intestinal flora of the offspring. The high-fat diet during post-pregnancy period increased the abundance of Tenericutes (P<0.05), and decreased the abundance of Bacteroides, Epsilonbacteraeota, Cyanobacteria, and Deferribacteres (all Ps<0.05). At the genus level, high-fat diet during both pre-pregnancy and post-pregnancy periods decreased the abundance of Lactobacillus (P<0.05), and high-fat diet during pre-pregnancy period increased the abundance of Alistipes (P<0.05), while high-fat diet during post-pregnancy period increased the abundance of Lachnospira and Ruminococcus, and decreased the abundance of Muribaculaceae and Helicobacter (all Ps<0.05). The results of beta diversity analysis showed that the CD-CD group had a similar flora composition to the HFD-CD group, and the CD-HFD group had a similar flora composition to the HFD-HFD group, and the results of Anosim analysis showed statistically significant differences between groups (R=0.743, P<0.01). The LEfSe analysis counted all species with an effect on the differences between groups greater than the set value, which were Lactobacillus in the CD-CD group, Clostridiales in the CD-HFD group, Bacteroidetes and Helicobacters in the HFD-CD group, and Blautia, Ruminococcaceae, and Roseburia in the HFD-HFD group. Conclusion It is found that varied effects of high-fat diet in different periods on the flora of the offspring mice. The high-fat diet during pre-pregnancy and post-pregnancy periods could reduce the abundance of Lactobacillus, but show different effects on the abundance of other intestinal flora such as Muribaculaceae, Lachnospiraceae, and Helicobacter differed. Diet during post-pregnancy period has a greater influence on modeling the offspring gut microbiota.
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Objective To evaluate the therapeutic effect of antibiotics combined with recombinant tuberculosis vaccine AEC/BC02 on Mycobacterium tuberculosis infection in guinea pigs. Methods Two weeks after guinea pigs were challenged subcutaneously with a high dose of Mycobacterium tuberculosis,the guinea pigs with the positive skin test responses to the recombinant ESAT6-CFP10 allergen were randomly di-vided into four groups:normal saline (NS),AEC/BC02,antibiotics and antibiotics+AEC/BC02. In antibiotics+AEC/BC02 group,guinea pigs firstly received isoniazid ( INH) and rifapentine ( RFT) treatment once a week for a total of three times,and then were immunized with a single dose of AEC/BC02 vaccine six times at 10-day intervals. Guinea pigs in AEC/BC02 and antibiotics groups were respectively vaccinated with AEC/BC02 vaccine and given INH and RFT treatment at the same dose and frequency as given to antibiotics+ AEC/BC02 group. Thirteen weeks after challenge,all guinea pigs were sacrificed for necropsy. Results The gross pathological scores of NS,AEC/BC02,antibiotics and antibiotics+AEC/BC02 groups were 83±8,77± 22,45±28 and 19±14,respectively. Antibiotics+AEC/BC02 group had a significantly lower gross pathological score than antibiotics,AEC/BC02 and NS groups (P<0. 05,P<0. 01,P<0. 01,respectively). Moreover,the gross pathological scores of antibiotics and AEC/BC02 groups were significantly decreased as compared with that of NS group (both P<0. 01). However,there was no significant difference between AEC/BC02 and NS groups. The spleen bacterial load of antibiotics+AEC/BC02 group was (2. 50±1. 26) lg CFU,which was sig-nificantly lower than those of NS [(4. 92+0. 52) lg CFU],AEC/BC02 [(4. 78+0. 84) lg CFU] and antibi-otics [(4. 39+0. 50) lg CFU] groups (P<0. 01). Compared with NS group,antibiotic and AEC/BC02 groups showed no significant difference in spleen bacterial load. Histopathological changes indicated different levels of granulomatous lesions appeared in lung tissues of all groups and the most severe change was ob-served in AEC/BC02 group,followed by that in NS,antibiotics and antibiotics+AEC/BC02 groups. Conclu-sion INH and RFT treatment in combination with AEC/BC02 vaccine in the treatment of guinea pigs with Mycobacterium tuberculosis infection was superior to either treatment alone as it significantly alleviated organ lesions and lowered the bacterial loads in spleen and lung.
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Objective To identify the cross-reactive antigens shared by Mycobacteria smegmatis(MS) and Mycobacteria tuberculosis(MTB) and to analyze their antigenicity.Methods Bacterial antigens were extracted from strains of MS and MTB by ultrasonication.Western blot assay was performed to analyze common antigens that reacted with both of the antiserum samples against MS and MTB.The extracted bacterial antigens were mixed with incomplete Freund′s adjuvant and then were injected into muscles of mice.Cytokines secreted by murine spleen lymphocytes following stimulation with various antigens of MS and MTB were determined by ELISPOT and flow cytometry on the 7th day.IgG levels in serum samples were detected by ELISA 7 days after injection.Results There were cross-reactive antigens shared by MS and MTB.Potent humoral immune responses and cellular immunity against both MS and MTB could be induced by those cross-reactive antigens after sensitization the mice by either MS or MTB antigens.Cytokines of IL-2 and IFN-γ in CD4+ and CD8+T cells of mice stimulated with MS or MTB antigens were significantly increased as compared with those of non-sensitization group and those of Brucella antigens stimulation group.ConclusionCross-reactive antigens shared by MS and MTS can effectively promote specific immune reactions to the infection of MTB, which provides a scientific basis for the development of tuberculosis vaccines.
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Objective To establish a suitable guinea pig model for evaluating the protective effects of new TB vaccines in BCG prime-boost regimen .Methods Two different immunization strategies by using the recombinant TB vaccine were employed to boost BCG primed guinea pigs in this study .One was for short-term evaluation with 14 weeks interval between prime and boost immunization and another was for long -term evaluation with 54 weeks interval .In the short-term evaluation group , guinea pigs were boosted twice with the recombinant TB vaccine ( AEC/BC02 ) in every two weeks , while guinea pigs in the long-term evaluation group were boosted for three times with two weeks interval between each injection .A negative con-trol group ( NS→NS) and a BCG control group ( BCG→NS) were both set up in two evaluation groups .One week after the last immunization , all guinea pigs were challenged with M.tuberculosis.Six to seven weeks after bacteria challenge , all animals were euthanized and dissected to evaluate lesion scores of liver , spleen and lung, as well as the viable bacterial load in spleen .Results In the short-term evaluation group , the le-sion scores in those boosted with vaccine (3.33±5.00) was lower than that of BCG control group (5.56± 7.27) (P>0.05) and negative control group (47.00±28.11) (P=0.0001).The difference between BCG control group and negative control group in lesion score was also significant .The animals in vaccine boosted group had lower bacterial loads (0.78±1.55 log10 ) in spleen than that in BCG control group (1.06±1.87) (P>0.05) and negative control group (5.47±0.61) (P=0.0003).In the long-term evaluation group, the lesion score in those boosted with vaccine was lower (5.0±7.6) than that in BCG control group (14.4± 13.5) (P=0.0394) and negative control group (56.9±14.1) (P0.05) and negative control group (5.43±0.56) (P=0.01).There was a significant difference in bacterial load between BCG control group and negative group (P=0.0089).Conclusion The results suggest that the interval time between BCG-prime and boost immunization should be properly prolonged in the guinea pig model used for evaluating the protective effects of new TB vaccines in BCG prime -boost regimen .
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Objective To establish a guinea pig model of latent Mycobacterium tuberculosis infec-tion for evaluating the effects of therapeutic vaccines .Methods Guinea pigs were subcutaneously inocula-ted with 5.0×103 CFU Mtb.The skin test was performed with 0.5μg recombinant ESAT6-CFP10 protein to detect positive conversion rates at different time points .Two weeks after Mtb inoculation , guinea pigs in model group received 5 mg isoniazid treatment ( three times a week for four weeks ) by oral gavage , while those in control group received normal saline .At the sixth week after Mtb infection , guinea pigs with and without isoniazid treatment were dissected for pathology examination .The pathological scores of liver , spleen and lung, as well as bacteria loads in spleen were compared between two groups .The established guinea pig model of latent infection was then validated by testing two reference vaccines ( AEC/BC02 and AEC/BC03 ) . Results Two weeks after Mtb inoculation , all guinea pigs showed positive EC skin test with induration area of (19.9±3.0) mm.Upon four weeks of isoniazid treatment , the guinea pigs in model group showed no pathological changes with zero scores in the examined organs .No bacterium was detected in spleen of ani-mals from model group.However, the total pathological score was 38.8±16.5 and bacteria load in spleen was (5.1±0.3) Log10 CFU with the guinea pigs from control group .Natural recurrence of tuberculosis in model group was observed after drug withdrawal .The total pathological scores were 48.5±23.9 and 51.3± 23.41.The bacterial loads in spleen were (4.5±1.3) and (4.2±1.1) Log10 CFU and bacterial loads in lung were (4.1±1.2) and (3.4±1.3) Log10 CFU respectively as verified with reference vaccines of AEC /BC02 and AEC/BC03.Conclusion Isoniazid treatment inhibited the proliferation of inoculated Mtb in guinea pigs.A guinea pig model of latent Mycobacterium tuberculosis infection is successfully established with an advantage of good repeatability .Therefore, it can be used to evaluate the effects of therapeutic vaccines on latent Mycobacterium tuberculosis infection.
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Objective To establish a suitable guinea pig model for evaluating the protective effects of new therapeutic TB vaccines in preclinical study .Methods The guinea pigs were subcutaneously injected with single-cell suspension of multi-drug resistant M.tuberculosis at a dose of 1000 CFU, 0.2 ml per animal.The study was divided into experimentⅠand experimentⅡ.In experimentⅠ, the guinea pigs were given immuno-therapy and/or chemical treatment on day 3 after infection .Four guinea pigs in each group were dissected at weeks 5, 7 and 9 after infection for evaluating lesion scores and histopathology changes of liver , spleen and lung, as well as bacterial load in spleen .In experimentⅡ, the guinea pigs were given immunotherapy and/or chemical treatment with different doses on day 14 after infection .All guinea pigs were dissected at week 5 after infection for evaluating lesion scores of liver , spleen and lung , as well as bacterial load in spleen .Results In experimentⅠ, all of the three treatments including immunotherapy combined with chemotherapy , immunotherapy alone and chemotherapy alone could effectively prevent organ lesion and reduce bacterial load in spleen , which were significantly different from negative control group .The immunotherapy combined with chemotherapy showed better treatment effects than other two treatments .Along with a prolonged period after drug withdrawal , the de-gree of organ lesion in immunotherapy group and chemotherapy group rebounded sharply , but only slightly in im-munotherapy combined with chemotherapy group .In experimentⅡ, animals in all treatment groups showed alle -viated organ lesion and reduced bacterial load in spleen .A relatively better treatment effect was observed in im-munotherapy combined with chemotherapy group .Conclusion The established guinea pig model of M.tubercu-losis infection showed an advantage of good repeatability .It might be used to evaluate the protective effects of new therapeutic vaccines against tuberculosis in preclinical study .
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Objective To comparatively evaluate the effects of a recombinant Mtb protein ESAT 6-CFP10 ( rESAT6-CFP10 ) and a purified protein derivative ( PPD ) as skin test reagents in guinea pigs . Methods Guinea pigs were sensitized with different Mycobacteria species .After sensitization , all guinea pigs were intradermally injected with rESAT6-CFP10 and PPD.At 48 h after the injection, the size of ery-thema at injection sites was measured by using a double-blind method .For guinea pigs sensitized with viable Mtb, the size of erythema at injection sites were measured at 24 h after the injection .The positive conversion rates of skin test with rESAT 6-CFP10 and PPD were calculated .Results The results of PPD skin test were positive in all guinea pigs sensitized with viable Mtb , killed Mtb and BCG with erythema diameters of (11.4 ±0.9) mm, (11.8±1.1) mm and (13.2±0.8) mm, respectively.Positive skin test with rESAT6-CFP10 was only observed in guinea pigs infected by viable Mtb-showing erythema diameters of (13.7±5.7) mm. The skin test with rESAT6-CFP10 was negative in guinea pigs sensitized by killed Mtb-and vaccinated by BCG.The skin tests by using rESAT6-CFP10 and PPD were performed on randomly selected guinea pigs at ninth day after infection by Mycobacterium tuberculosis H37Rv.At the 2nd week, totally 24 selected guinea pigs showed positive skin test results with rESAT6-CFP10 (24/24) with erythema diameters of (19.9± 3.0) mm, while only 15 out of 24 had positive PPD skin test with erythema diameters of (6.1±5.5) mm. At the 4th week, all guinea pigs showed positive PPD skin test (3/3) with erythema diameters of (12.7± 2.5) mm.Conclusion The skin test by using recombinant ESAT 6-CFP10 protein can effectively distin-guish viable Mtb infection from BCG vaccination and killed Mtb sensitization , which is a more suitable anti-gen than PPD for the early diagnosis of Mtb infection .
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Objective To study the interaction of genetic polymorphisms of CYP2E1 and environmental hazard factors in gastric cancer. Methods 1∶1 case-control study was carried out in Nanjing area, using PCR-RFLP technology to determined the genetic polymorphisms of CYP2E1 and epidemiological data about environmental exposure of 121 cases and controls were collected. Interaction indexes (?) were calculated to determine the type of gene-environment interaction. Results After confounding adjusted, the result showed that interaction existed in genetic polymorphisms of CYP2E1 RsaⅠand the family history of digestive system disease, smoking, pickled food, irregular diet habit, interaction indexes (?) value were 1.855, 2.626, 1.736 and 1.714 respectively. A low exposure-gene effect interaction was found in CYP2E1 RsaⅠgenotype and the frequency of pickled food consumed, while a high exposure-gene effect interaction exist in CYP2E1 RsaⅠgenotype and irregular diet habit. Conclusion Genetic and environmental hazard factors co-effect the development of gastric cancer, genetic polymorphisms of CYP2E1 and environmental risk factors show an interaction in gastric cancer.
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Objective To determine the association of glutathione-stransferase M1(GSTM1), T1(GSTT1) genetic polymorphisms, smoking and alcohol consumption with the risk of gastric cancer. Methods 1:1 matched case-control study and molecular epidemiology technique were used to analysis the genetic polymorphisms of GSTM1, GSTT1 genotype among 60 cases of gastric cancer patients and sex-and age-matched controls, who were selected from Nanjing Zhongda Hospital and Jiangsu Province Cancer Hospital. Statistical analysis was performed to elucidate interaction of GSTM1. GSTT1 genotype and smoking and alchol consumption in the risk for stomach cancer. Results The frequency of GSTT1 null genotype among cases and controls was 61.67% and 40.00% respectively (?2 =6.08, P