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Objective:To investigate the significance and mechanism of ten-eleven translocation (Tet1) against Mycobacterium marinum ( Mm) infection in mice. Methods:SPF wild-type C57BL/6 and Tet1-knockout (Tet1KO) mice were injected intravenously with Mm. All mice were monitored and the abscesses formed in tail were observed and quantified. Pathological changes in mouse tail tissues were observed using hematoxylin and eosin (HE) staining and transmission electron microscopy and the differences between the two groups were analyzed. Immunohistochemistry staining was used to detect the expression and distribution of TNF-α and TGF-β in mouse tail tissues. Moreover, mouse tail tissues were cultured on 7H10 plates for bacterial counting. The expression of NF-κBp65 and TGF-β was detected by Western blot. Results:Obvious lesions including abscesses and ulcers were formed in the Mm-infected C57BL/6, but only scattered small abscesses were observed in Mm-infected Tet1KO mice. During Mm infection, the bacterial load was gradually increased in C57BL/6 mice, but decreased in Tet1KO mice. Histopathological examination showed that obvious inflammatory cell infiltration and typical granulomatous lesions were found in Mm-infected C57BL/6 mice, while no significant inflammatory cell infiltration was detected in Mm-infected Tet1KO mice. Immunohistochemistry staining demonstrated that the expression of TNF-α and TGF-β was lower in Mm-infected Tet1KO mice than in Mm-infected C57BL/6 mice. Moreover, the expression of phosphorylated NF-κBp65 and TGF-β was significantly reduced in Mm-infected Tet1KO mice as compared with that in Mm-infected C57BL/6 mice. Conclusions:Deletion of Tet1 could alleviate the inflammatory damage mediated by Mm and enhance the host immune response to bacteria.
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Objective To establish a mouse model of pneumonia with C57BL/6 and MyD88KO mice after infection with an isolated ST23 Klebsiella pneumonia (KP) strain, which was an epidemic strain and identified by multilocus sequence typing (MLST). Methods Fifty C57BL/6 mice were randomly di-vided into three groups:KP infection,control and immunosuppressive groups. Thirty MyD88KO mice were divided into KP infection and control groups. All mice in the KP infection groups were infected with 50 μl of ST23 KP strain through nasal dripping. Equal volume of PBS was used to set up the control groups. Mice in the immunosuppressive group were first injected with cyclophosphamide for three days and then infected with equal volume of ST23 KP strains through nasal dripping. Clinical signs and survival curves during KP infec-tion were monitored. Moreover,pulmonary bacterial loads and histopathological changes in the KP-infected mice were detected at different time points. Results ST23 KP-infected C57BL/6 mice showed inflammatory cell infiltration in lung tissues on the 10th day and remained alive on the 21st day. All ST23 KP-infected MyD88KO mice died on the 5th day with severe histopathological damage in lung tissues. C57BL/6 mice that pretreated with cyclophosphamide had similar symptoms with MyD88KO mice after infection and died on the 5th day. Some critical inflammatory mediators such as TNF-a,nitric oxide synthase 1 (NOS1) and NF-κBp65 were up-regulated in lung tissues of mice after KP infection. No inflammatory syndromes were found in the mice of PBS control groups. Conclusion This study suggests that the mouse model of pneumonia is successfully established with KP strain. It will help researchers to study the characteristics and pathogenesis of ST23 KP strain-induced pneumonia and to seek safe treatments in the future.
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ObjectiveTo compare three types of acute Mycobacterium tuberculosis infection mouse models established through different infection routes and to set up the theoretical basis for further developing,selecting and applying these animal model in the tuberculosis-related research.MethodsStandard strain of Tubercle bacillus H37Rv was diluted to 1 × 106 colony forming unit (cfu)/mL.The mice were infected with the bacteria through different routes including intravenous injection,intranasal administration and inhalation of bacteria aerosol.Six weeks after the infection,the mice were euthaniz ed and necropsied. The lung tissues were collected and gross changes were observed.The colony counting was performed and the lung tissues were assessed by HE staining,acid fast staining.The e xpression level of tumor necrosis factor (TNF)-α per unit area in lung tissue was detected by immunohistochemistry. The data were analyzed by t test. Results The amounts of Mycobacterium tuberculosis in lung tissues of mice in inhalation group,intranasal administration group and intravenous injection group were (6.290±0.028),(6.150±0.021) and (6.120±0.008) lg cfu/mL,respectively; while no Mycobacterium tuberculosis was detected in control group. The difference between infection group and control group was statistically significant (t =3.762,P＜0.01),while there were no significant differences among infection groups with different infection routes (P＞0.05).According to the results of gross observations and histological assessment,the pathological changes were observed and red tubercle bacillus was detected by acid-fast staining in the lung tissues of all the mice in infection group.The results of immunohistochemistry showed that the expression levels of TNF-α per unit area were as follows:intravenous injection group (0.049 × 106 )＜intranasal administration group(0.759×106) ＜ inhalationgroup(1.042×106), whichwere statistically different (t =2.504,P＜ 0.05).ConclusionInhalation of bacteria aerosol may be the most efficient method to establish tuberculosis infection mouse model compared to intravenous injection and intranasal administration.
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Objective To established a bacteriemia model of BALB/c mice after infection with a ST-239 methicillin-resistant staphylococcus aureus(MRSA) strain, which was isolated and identified from Shanghai Huashan Hospital. Methods We monitored the clinical signs and gross observations of MRSA-infected mice, and examined the histopathology among different groups. Results This isolated MRSA strain ST-239 can induced a typical bacteriemia in BALB/c mice, including the severe mortality and extensive histopathologic injury. However, higher survival rate and slight inflammatory injury were observed in vancomycin-treated mices. Conclusion The solid results obatined in this model will benefit us to study the pathogenic characteristics and patholgenesis in MRSA-induced bacteriemia, and propeled us to seek a safety cure approaches in the future.
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Objective To evaluate the relationship of diurnal variation of antidiuretic hormone (ADH) with urinary output,serum osmolality and blood pressure in spinal cord injury (SCI) patients. MethodsThe study was prospective,random and contrastive. Twenty complete SCI patients (two females and 18 males,Complete SCI group) and ten healthy controls (two females and eight males,control group) were studied. Urinary output and osmolality in the day time (8:00-20:00) and at night (20:00-8:00) were recorded. Blood samples for the measurement of serum osmolality and ADH were drawn at 14:00 and 2:00. Results There was very significant difference in regard of urinary output between day time and night time in complete SCI Group and control Group ( P 0.05). However,ADH level increased in the healthy Group at night,with a very significant difference ( P
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Objective To study the safety of laparoscopic total mesorectal excision for middle and lower rectal cancer.Methods A retrospective comparison was made between 52 cases of open total mesorectal excision from December 2002 to December 2005(Open Group) and 49 cases of laparoscopic mesorectal excision from January 2003 to June 2006(Laparoscopic Group).Results There was no difference in baseline parameters between the two groups.As compared with the Open Group,the Laparoscopic Group presented less blood loss [for anterior resection: 160?106 ml(n=37) vs 298?186 ml(n=36),t=-3.908,P=0.000;for abdominoperineal resection: 180?153 ml(n=10) vs 356?170 ml(n=14),t=-2.604,P=0.016].The recovery time of bowel functions was shorter in the Laparoscopic Group than in the Open Group(2.4?1.8 d vs 3.6?1.5 d;t=-3.648,P=0.000).The overall complication rate in the Laparoscopic Group(14.3%,7/49) was lower than that in the Open Group(44.2%,23/52)(?2=10.834,P=0.001).No significant difference was seen between the two groups in the number of lymph node resected(12.7?6.5 vs 13.6?7.0;t=-0.668,P=0.505),with negative margins in both groups.Follow-up observations were carried out in 45 cases in the Laparoscopic Group(91.8%) for 2～42 months and in 47 cases in the Open Group(90.4%) for 6～42 months,respectively.The local recurrence rate was respectively 4.4% in the Laparoscopic Group(2/45) and 4.3% in the Open Group(2/47). Conclusions Laparoscopic total mesorectal excision for middle and lower rectal cancer is safe and feasible.
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Objective To introduce the methods,complications and management of transiliaca external artery port catheter system (PCS) implantation,and to discuss its feasibility and superiority. Methods Transiliaca external artery PCS implantation were performed in 110 patients with medium or advanced malignant hepatic tumor.There were 86 male and 24 female, with average 50.8 years old, including 68 cases primary hepatic cancer, 42 cases metastatic cancer. Follow-up time was 2～53 months. Results The operation successful rate was 98.2% (108/110). Complications included: puncture local hematoma in 5 cases (4.5%), cut infection in 1 case (0.9%), slow bleeding in cut in 2 cases (1.8%), light swelling and paining of right testicle in 1 case (0.9%), target arteries occlusion or serious narrowness in 6 cases (5.5%), displacement of the tip of catheter in 3 cases (2.7%). Complications rate was 15.5% (17/110).Conclusion Transiliaca external artery PCS implantation is safe and feasible, the successful rate is higher and complications rate is lower, it can be introduced as a sort of routine method.