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1.
We investigated the response to challenge infection with Cryptosporidium parvum oocysts in immunosuppressed C57BL/6N mice. In the primary infection, fecal oocyst shedding and parasite colonization were greater in immunosuppressed mice than in nonimmunosuppressed mice. Compared with primary infection, challenge infection with C. parvum didn''t show any oocyst shedding and parasite colonization. Especially, oocyst shedding and parasite colonization from the mice infected with heat-killed oocysts were not detected. After challenge infection with C. parvum oocysts, however, these mice were shedding small numbers of oocysts and parasite colonization. Except normal control and uninfected groups, the antibody titers of other groups appear similar. Based on the fecal oocyst shedding, parasite colonization of ilea, and antibody titers in the mice, these results suggest that the resistance to challenge infection with C. parvum in immunosuppressed C57BL/6N mice has increased.  相似文献   

2.
为了解流行性乙型脑炎病毒基因I型毒株SD12在感染C57BL/6小鼠体内的病毒分布,应用qRT-PCR方法检测该毒株在小鼠体内各组织的动态分布情况.结果显示腹腔感染组中2 dpi仅能在心脏和脾脏检测出病毒核酸,5～7 dpi能够在心脏、肝脏、脑部、盲肠和扁桃体检测到病毒核酸.血脑屏障受损的腹腔感染组中最早2 dpi在肠...  相似文献   

3.
The classic piebald mutation in the endothelin receptor type B (Ednrb) gene was found on rolling Nagoya genetic background (PROD-s/s) mice with white coat spotting. To examine whether genetic background influenced the phenotype in the piebald mutant mice, we generated a congenic strain (B6.PROD-s/s), produced by repeated backcrosses to the C57BL/6J (B6) strain. Although B6.PROD-s/s mice showed white coat spotting, 7% of B6.PROD-s/s mice died between 2 and 5 weeks after birth due to megacolon. The PROD-s/s, s/s and Japanese fancy mouse 1 (JF1) strains, which also have piebald mutations on different genetic backgrounds with B6, showed only pigmentation defects without megacolon. In expression analyses, rectums of B6.PROD-s/s with megacolon mice showed ~5% of the level of Ednrb gene expression versus B6 mice. In histological analyses, aganglionosis was detected in the rectum of megacolon animals. The aganglionic rectum was thought to lead to severe constipation and intestinal blockage, resulting in megacolon. We also observed an abnormal intestinal flora, including a marked increase in Bacteroidaceae and Erysipelotrichaceae and a marked decrease in Lactobacillus and Clostridiales, likely inducing endotoxin production and a failure of the mucosal barrier system, leading ultimately to death. These results indicate that the genetic background plays a key role in the development of enteric ganglion neurons, controlled by the Ednrb gene, and that B6 has modifier gene (s) regarding aganglionosis.  相似文献   

4.
The development and testing of vaccines for Neospora caninum in mice require challenge studies to demonstrate a reduction in clinical signs or prevention of vertical transmission of the parasite after vaccination. Genetic susceptibility to N. caninum varies with the strain of mice. In this study, C57BL/6 mice were evaluated as a model for Neospora vaccine studies. A lethal challenge model was developed and the LD(50) was determined to be 1.5 x 10(7)N. caninum tachyzoites/mouse, delivered intraperitoneally. Brain lesions encountered in sections from sub-lethally challenged mice were scored on the basis of severity and total number of lesions to develop a histopathological scoring system for vaccine efficacy. A vertical transmission model for N. caninum vaccine studies was developed by studying mice that were infected either 2 weeks prior to mating or between days 12 and 14 of pregnancy. It was found that infection prior to mating reduced the average number of pups per litter. DNA extracted from fetal tissue was examined by a N. caninum specific polymerase chain reaction (PCR). The rate of vertical transmission was 0, 100 and 90.5% for the uninfected controls, mice infected during pregnancy and mice infected before mating, respectively. This study demonstrates that the C57BL/6 strain of mice is a good model for N. caninum vaccine studies because it is possible to establish a clear-cut lethal challenge model in C57BL/6 mice and they transmit the disease to their offspring efficiently.  相似文献   

5.
It is well-known that there are considerable strain differences in the relative copulation rates between male and superovulated female mice. In particular, the C57BL/6J strain of mice has a lower rate of successful copulation. We examined the effect of exposure to an electric field on sexual behavior in C57BL/6J male mice. When C57BL/6J males were exposed to a 50 Hz, 45 kV/m electric field for 30 min per day for 11 days and placed in a cage with a superovulated female of the same strain, the successful copulation rates of males was significantly improved compared with unexposed males (P<0.05). These results suggest that the exposure of C57BL/6J male mice to an electric field improves their sub-fertility activity in mating with superovulated females.  相似文献   

6.
Adipose tissues in mammals are categorized into white and brown adipose tissues in which cellular morphology, cell functions, and tissue distribution are different. White adipose tissue (WAT) plays a major role in energy reservation, while brown adipose tissue (BAT) mainly relates to the thermoregulation of the body. One interesting function of adipose tissue is the response to the infection, especially the pathogens that cause pneumonia. We have previously reported that DBA/2 (D2) mice are susceptible to pathogens causing pneumonia, Mycoplasma (M.) pulmonis and Sendai virus (SeV), whereas C57BL/6 (B6) mice are resistant to them. Furthermore, morphological alteration of mediastinal fat tissue (MFT) was seen after infection of M. pulmonis in D2 mice but not in B6 mice. In this study, we aimed to exhibit the difference in adipose tissue response in other areas, including interscapular brown adipose tissue (iBAT), inguinal white adipose tissue (ingWAT), and perigonadal WAT (perigoWAT) between resistant strain, B6 and susceptible strain, D2 after challenging them with M. pulmonis and SeV. Compared with B6 mice, D2 mice showed an increase in fat-associated lymphoid cluster in MFT, an increase in BAT in both iBAT and ingWAT after M. pulmonis and SeV infection. The results of this study indicate that pneumonia caused by M. pulmonis and SeV infection induces browning of adipocyte, suggesting that BAT plays a role in pathogen infection and inflammation.  相似文献   

7.
This study was to investigate the anti-obesity effects of diglyceride (DG)-conjugated linoleic acid (CLA) containing 22% CLA as fatty acids in C57BL/6J ob/ob male mice. There were four experimental groups including vehicle control, DG, CLA, and DG-CLA. The test solutions of 750 mg/kg dose were orally administered to the mice everyday for 5 weeks. CLA treatments significantly decreased mean body weight in the obese mice throughout the experimental period compared to the control (p < 0.01). All test solutions significantly decreased the levels of triglyceride, glucose and free fatty acids in the serum compared with control (p < 0.05). The levels of total cholesterol were also significantly reduced in DG and DG-CLA groups compared with the control group (p < 0.05). CLA significantly decreased weights of renal and epididymal fats compared with the control (p < 0.05). DG and DG-CLA also significantly decreased the epididymal fat weights compared with the control (p < 0.05). A remarkable decrease in the number of lipid droplets and fat globules was observed in the livers of mice treated with DG, CLA, and DG-CLA compared to control. Treatments of DG and CLA actually increased the expression of peroxisome proliferator-activated receptor gamma. These results suggest that DG-CLA containing 22% CLA have a respectable anti-obesity effect by controlling serum lipids and fat metabolism.  相似文献   

8.
SPF级BALB/cC57BL/6小鼠繁殖性能及生长发育的比较研究   总被引：1，自引：0，他引：1  
为提高SPF级实验动物的质量,选择10周龄BALB/c C57BL/6小鼠各50只（雌雄各半）,采取雌雄1？1近亲交配繁殖,并统计其生长发育和繁殖性能指标。BALB/c小鼠1～3周龄的平均窝重及离乳后的体重增长明显大于C57BL/6小鼠（p〈0.01）。第1胎交配分娩间隔,第1和第3胎离乳育成率品系间差异均有显著性（P〈0.05及P〈0.01）。BALB/c小鼠的体格比C57BL/6小鼠大,带乳能力比C57BL/6小鼠强但产仔能力比C57BL/6小鼠弱。  相似文献   

9.
对C57BL／6小鼠超排效果的研究   总被引：1，自引：0，他引：1  
本文以近交系C57BL／6小鼠为实验对象．研究注射不同剂量的PMSG和hCG对小鼠超排效果的影响。取C57BL／6小鼠各30只,按照注射剂量不同分为A、B、C三组,每组10只,A组注射PMSG2．5IU,HCG2．5IU,B组注射PMSG5．0IU,HCG5．0IU,C组注射PMSG7．5IU,HCG7．5IU。每只小鼠腹腔注射PMSG,间隔48h后分别注射HCG进行超数排卵,再与性成熟同系公鼠合笼,次日早上检查阴道栓．有栓雌鼠用颈椎脱臼法处死。在实体显微镜下由输卵管膨大部冲卵．收集卵母细胞置于盛有M2培养液的表面皿中检查计数．分析超排效果。结果表明。C57BU6小鼠B组的平均取卵数极显著高于A组的平均取卵数（P〈0．05）;B组的平均取卵数显著高于C组的平均取卵数（P〈0．05）;C组与A组的平均取卵数差异不显著（P〉0．05）。  相似文献   

10.
Inflammatory diseases such as type 2 diabetes (T2D) in humans and mice are under the influence of the composition of the gut microbiota (GM). It was previously demonstrated that treating Lep(ob) mice with antibiotics improved glucose tolerance. However, wild type C57BL/6J mice may also exhibit plasma glucose intolerance reminiscent of human T2D. We hypothesized that antibiotic treatment in C57BL/6 mice would have an impact on glucose tolerance without affecting weight and gut immunology. When compared to mice treated with erythromycin or the controls, treatment for five weeks with ampicillin improved glucose tolerance without significantly affecting the weight or the number of gut mucosal regulatory T cells, tolerogenic dendritic cells or T helper cells type 1. 16S rRNA gene based denaturing gradient gel electrophoresis profiles clearly clustered according to treatment and showed that antibiotic treatment reduced GM diversity. It is concluded that antibiotic treatment changes glucose metabolism as well as the composition of the GM in C57BL/6 mice, and that this does not seem to be correlated to weight development in the mice.  相似文献   

11.
The purpose of this study was to identify different expression of microRNAs between cerebellum of SPRN0/0 mice and C57BL/6 wild mice, and investigate relative expression results of microRNA in cerebrum of SPRN0/0 mice by Real-time PCR technology. The results showed that compared with cerebellum of C57BL/6 wild mice, eight microRNAs were decreased significantly:miR-135a, miR-24-2*, miR-146a, miR-7a, miR-380, miR-448, miR-128 and miR-152. miR-24-2* fold change to more than 10, five microRNAs including miR-448,miR-146a,miR-128,miR-380 and miR-152 fold change to more than 2, miR-135a and miR-7a fold change to more than 1. Thus, we concluded that these changes of microRNAs expression might be involved in Shadoo protein function and the establishment of target genes of microRNAs might provide new ideas for researching Shadoo protein function.  相似文献   

12.
Sixteen calves and 6 cows were each inoculated with 100 000 infective oocytes of the GT-1 strain of Toxoplasma gondii. Cattle were necropsied between 3 and 287 days post-inoculation (DPI) and their tissues were inoculated into mice or fed to Toxoplasma-free cats for the detection of Toxoplasma in bovine tissues. Ten to 10 000-fold more T. gondii were recovered from small intestine and mesenteric lymph nodes of calves at 3 and 6 DPI than from lungs and liver, and the number of T. gondii in bovine tissues was reduced 1000-fold between 6 and 8 DPI. By using the pepsin digestion technique, or feeding tissues to Toxoplasma-free cats, it was demonstrated that T. gondii encysted in bovine tissues as early as 11 DPI and persisted as late as 287 DPI. More Toxoplasma gondii cysts occurred in livers than in any other bovine tissue. Of the 6 cows inoculated at 95–155 days after breeding, 5 delivered normal calves and T. gondii was isolated from only one of these calves. One cow was barren. Toxoplasma gondii was not isolated either by mouse inoculation or by feeding cats tissues from 2 cows killed 132 and 190 DPI. Toxoplasma gondii was not isolated in mice inoculated with tissues of cows killed 98 and 109 DPI, but cats fed on bovine tissues shed T. gondii oocysts. The organism, however, was isolated in mice inoculated with the mesenteric lymph nodes of 1 of the 2 cows killed 162 and 168 DPI, and from the small intestine of the other. Cats fed tissues of these cows later shed T. gondii oocysts.  相似文献   

13.
Apolipoprotein E deficient (Apo E?/?) mice are more resistant to the development of obesity compared to C57BL/6 wild type mice. They also hold a high basal oxidative status due to the loss of antioxidant action of apolipoprotein E. Since obesity is also an inducer of inflammation, we studied the effect of high‐fat diet on obesity and oxidative stress in C57BL/6 and Apo E?/? mice for 9 weeks. The results confirmed that Apo E?/? mice fed high‐fat diet are more resistant to the increase of both body weight and adiposity compared to C57BL/6 mice. Despite this, Apo E?/? mice presented a higher basal oxidative stress that was enhanced by high‐fat diet. Macrophage infiltration, macrophage forming crown‐like structures and proinflammatory adipokines (interleukin 6 and tumor necrosis factor alpha) were all higher in adipose tissue from Apo E?/? compared to C57BL/6 mice, regardless of diet type. In conclusion, although Apo E?/? mice are more resistant to becoming obese, they develop more severe adipose tissue inflammation companied by its consequences.  相似文献   

14.
Lymphoma is the third most common cancer diagnosed in children, and T-cell lymphoma has the worst prognosis based on clinical observations. To date, a lymphoma model with uniform penetrance has not yet been developed. In this study, we generated a p53 deficient mouse model by targeting embryonic stem cells derived from a C57BL/6J mouse strain. Homozygous p53 deficient mice exhibited a higher rate of spontaneous tumorigenesis, with a high spontaneous occurrence rate (93.3%) of malignant lymphoma. Because tumor models with high phenotypic consistency are currently needed, we generated a lymphoma model by a single intraperitoneal injection of 37.5 or 75 mg/kg N-methyl-N-nitrosourea to p53 deficient mice. Lymphoma and retinal degeneration occurred in 100% of p53+/− mice administered with higher concentrations of N-methyl-N-nitrosourea, a much greater response than those of previously reported models. The main anatomic sites of lymphoma were the thymus, spleen, bone marrow, and lymph nodes. Both induced and spontaneous lymphomas in the thymus and spleen stained positive for CD3 antigen, and flow cytometry detected positive CD4 and/or CD8 cells. Based on our observations and previous data, we hypothesize that mice with a B6 background are prone to lymphomagenesis.  相似文献   

15.
A fatal encephalomyelitis was developed after intracerebral and hind limb inoculation of in 6-week-old C57BL/6J mice by the inoculation of fixed rabies virus (CVS-11 strain), intracerebrally and into hind. After the intracerebral inoculation, virus antigens were detected in the cerebral cortex and hippocampus at 2 days postinoculation (PI), and later spread centrifugally to thalamus, brain stem, cerebellum, spinal cord and spinal ganglia. At 4 days PI, severe apoptosis and DNA fragmentation were observed in the hippocampus and cerebral cortex. All mice infected intracerebrally were dead without limb paralysis at from 10 to 11 days PI. In contrast, mice infected with virus intramuscularly were persistently observed virus antigens in the myocytes at the site of inoculation from 2 days PI. At 4 days PI, the antigens were demonstrated in the spinal dorsal root ganglia, spinal cord and muscle spindles without their detection in the cerebrum and hippocampus. There were no apoptosis in the spinal cord and dorsal root ganglia, however hind limb paralysis was found in all infected mice. Hind limb paralysis was progressed to quadriparalysis, and mice were dead from 11 to 13 days PI. From 4 days PI, necrosis of neuron was observed in the the spinal and dorsal ganglia with infiltration of lymphocyte. This study suggested that the necrosis of spinal neurons was more important to cause the paralysis of hind limb rather than the severe cerebral infection and apoptosis in C57BL/6J mice infected with CVS-11 strain. The virus primarily replicated in the muscles was ascended the spinal cord via afferent fibers and retrogradely invaded the cerebrum, and with subsequent spread to muscle spindles.  相似文献   

16.
The accumulation of various T cell subsets in Bcg-susceptible (C57BL/6) and -resistant (C3H/HeN) strains of mice were compared following an intraperitoneal infection with Mycobacterium paratuberculosis. Groups of mice from both strains were killed at 3, 5, 10, 15, 30, and 150 days after infection and lymphocytes were harvested from the peritoneal exudate cells (PEC), spleen, intestinal epithelial lymphocytes (IEL), lamina propria lymphocytes (LPL), Peyer's patches, and mesenteric lymph node (MLN) and labelled with monoclonal antibodies to CD3, CD4, CD8, γδ TCR, CD25, and CD44 for flow cytometric analysis. Uninfected C3H/HeN mice had higher proportions of CD4+ cells in the spleen, MLN, LPL, IEL and Peyer's patches, while uninfected C57BL/6 mice had higher proportions of CD8+ and/or γδ T cells. Significant increases in accumulation of CD8+ and γδ T cells were detected in the peritoneum and other tissues in both strains of mice after infection. Higher CD4/CD8 ratios were observed in most lymphoid tissues of C3H/HeN mice, while increased proportions of CD8+ and/or γδ T cells were present in C57BL/6 mice. These results indicate that significant differences in T cell profiles exist between these two strains of mice, both inherently and in response to infection with M. paratuberculosis. Innately lower levels of CD4+ cells and/or higher percentages of CD8+ and γδ T cells may play a role in the increased susceptibility of C57BL/6 mice to infection with M. paratuberculosis.  相似文献   

17.
The differences between the dorsal skin of 11- and 16-week-old C57BL/6J mice were examined morphologically and biochemically. The dermis of the 16-week-old mice was thinner than that of the 11-week-old mice due to decreases in the amounts of soluble collagen and elastin. Next, the changes in dorsal skin exposed to UVA irradiation for 8 weeks (576 J/cm(2)) were examined in 3 (younger)- and 8 (older)-week-old C57BL/6J mice. The thickness of the dermis was not significantly different between the UVA-irradiated and control mice in either the younger or older group. The increase in the amount of collagen was related to the increase in the level of soluble collagen in the younger mice. In contrast, it was related to the increase in the level of insoluble collagen in the older mice. In the UVA-irradiated older mice, the activity of the latent form of MMP-13 was significantly higher than that in the control mice. These results suggest that aging and UVA-induced photoaging in the skin are histologically and biochemically different phenomena.  相似文献   

18.
The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) of the gastrointestinal tract of C57BL/6 mouse was studied with immunohistochemical method using seven types of specific anti-sera against chromogranin A (CGA), serotonin, somatostatin, human pancreatic polypeptide (HPP), glucagon, gastrin and cholecystokinin (CCK)-8. In this study, all these seven types of immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle in shape (open-type cell) while cells showing round in shape (closed-type cell) were found in the intestinal gland and stomach regions occasionally. Their relative frequencies were varied according to each portion of gastrointestinal tract. CGA-IR cells were demonstrated throughout the whole gastrointestinal tract and they showed most predominant in the pylorus and duodenum. Serotonin-IR cells were detected throughout whole gastrointestinal tract and they showed highest frequency in the stomach and colon. Somatostatin-IR cells were demonstrated throughout whole gastrointestinal tract except for large intestine and showed highest frequency in the fundus. HPP-IR cells were found in the fundus with rare frequency. Peculiarly, glucagon-IR cells were restricted to the fundus, ileum and colon with a few frequencies. Gastrin-IR cells were restricted to the pylorus with numerous frequency and CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with numerous and/or a few frequencies, respectively. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in C57BL/6 mouse.  相似文献   

19.
The immature platelet fraction (IPF) is a measure of newly released platelets, which has been used as a marker of platelet production in multiple human studies but is not widely available in multispecies analyzers. We developed gates to measure the IPF in diluted and undiluted murine blood samples on the Sysmex XN-1000V multispecies hematology analyzer. IPF gates were created using undiluted and diluted (1/10) blood samples obtained from adult and newborn (postnatal day 10, P10) C57BL/6J wild-type (WT) mice, and from 3 murine models of thrombocytopenia: c-MPL−/− mice, which lack the thrombopoietin receptor (hyporegenerative); antibody-mediated thrombocytopenia; and acute inflammation-induced thrombocytopenia. P10 mice were chosen because, at their size, we could consistently obtain (by terminal phlebotomy) the blood volume needed to run an undiluted sample. The undiluted blood IPF gate successfully differentiated between mechanisms of thrombocytopenia in both adult and P10 mice. For diluted samples, 2 IPF gates were generated: a thrombocytopenic (T) gate, which performed well in samples with platelet counts (PCs) <800 × 109/L in adult mice and <500 × 109/L in newborn mice, and a non-thrombocytopenic (NT) gate, which performed well in samples with PCs above these thresholds. PCs and IPFs measured in diluted blood using these gates agreed well with those measured in undiluted blood and had good reproducibility. These diluted gates allow for the accurate measurement of PCs and IPFs in small (10 µL) blood volumes, which can be obtained easily from adult and newborn mice as small as P1 to assess platelet production serially.  相似文献   

20.
More effective vaccines against Toxoplasma gondii may contribute to the control of this pathogen that has major veterinary and public health significance. In this study, two recombinant plasmids pcDNA/TgSAG1 and pVAX/mIL-18 containing T. gondii SAG1 (TgSAG1) and murine cytokine interleukin-18 (IL-18) were evaluated for their ability to protect mice against T. gondii challenge. Mice were given two intramuscular immunizations 3 weeks apart, and challenged with T. gondii 3 weeks later. All animals vaccinated with pcDNA/TgSAG1 alone or with pVAX/mIL-18 developed specific anti-TLA (T. gondii lysate antigen) antibodies and specific lymphocyte proliferative responses. Co-injection of pVAX/mIL-18 significantly increased the production of IFN-γ and IL-2. Further, challenge experiments showed that co-immunization with pVAX/mIL-18 significantly (P < 0.05) increased the survival rate (60%), compared with pcDNA/TgSAG1 alone (40%). Therefore, codelivery of the IL-18-secreting plasmid potentiates the induction and maintenance of the type 1 helper T-cell immune response and may be a potent strategy for enhancing the protective efficacy of vaccines against T. gondii.  相似文献   

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