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Novel coronavirus Omicron variant infection can cause severe illness and even death in certain populations. Omicron variant infection may lead to systemic inflammatory response, coagulation disorder, multi-organ dysfunction and other pathophysiological changes, which are different from other Novel coronavirus variants to a certain extent, so therapeutic strategies should not be the same. The National Medical Center for Major Public Health Events invited experts in fields of infectious diseases, respiratory medicine, intensive care, pediatrics and fever clinic to develop this quick guideline based on the current best evidence and extensive clinical practices. This quick guideline aims to standardize the diagnosis and treatment of novel coronavirus Omicron infection, and to improve the disease management abilities of clinicians.
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Objective:To investigate the expression of macrophage migration inhibitory factor (MIF) in bone marrow fluid and peripheral blood of patients with acute myeloid leukemia (AML) and its effect on the expression of interleukin-8 (IL-8) in bone marrow mesenchymal stem cells (BM-MSC).Methods:Fifty bone marrow fluid samples and 50 peripheral blood samples were collected from 50 patients with AML diagnosed in the First People's Hospital of Yunnan Province from October 2017 to January 2019, of which 17 patients were newly diagnosed, 26 patients were complete remission (CR), and 7 patients were partial remission (PR) or non-remission (NR). Fifty plasma samples from 50 healthy subjects and 50 bone marrow fluid samples from 50 patients with iron deficiency anemia were used as the controls. Enzyme-linked immunosorbent assay (ELISA) was used to detect the level of MIF protein in the samples, and the relationship between MIF expression level and clinicopathological characteristics of AML patients was analyzed. BM-MSC was successfully isolated and cultured from 42 bone marrow fluid samples of AML patients, the suitable samples for experiment were chosen and divided into BM-MSC control group (untreated BM-MSC), recombinant human macrophage migration inhibitory factor (rhMIF) group and rhMIF+ISO-1 group. ELISA and real-time fluorescence quantitative polymerase chain reaction were used to detect the expression level of IL-8 protein and mRNA in each BM-MSC group.Results:The expression levels of MIF protein in bone marrow fluid and plasma in AML group were (24.9±7.7) ng/ml and (60.5±12.1) ng/ml, the difference was statistically significant ( P < 0.01), and those in control group were (5.3±2.6) ng/ml and (2.0±1.1) ng/ml, respectively, and there were statistical differences between the two groups (t values were 136.71, 33.97 and 17.58, all P < 0.01). MIF protein expression levels in bone marrow fluid and plasma of AML patients in newly diagnosed group and PR+NR group were higher than those in CR group, and the differences were statistically significant (all P < 0.01). MIF protein expression levels were higher in bone marrow fluid and plasma of patients with ≥60 years of age, peripheral blood white blood cell count ≥30×10 9/L and bone marrow myeloblast ratio > 0.50 (all P < 0.05), but the differences were not statistically significant between patients with different gender (both P > 0.05). The detection results of each BM-MSC group showed that rhMIF promoted the IL-8 expression in BM-MSC at the gene and protein levels, which could be inhibited by the MIF inhibitor ISO-1 (all P < 0.01). Conclusion:The increased expression levels of MIF in bone marrow fluid and plasma of patients with AML are associated with the disease progression, and rhMIF can promote the expression of IL-8 in BM-MSC.
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Objective@#To evaluate the value of T cell spot test of tuberculosis infection(T-SPOT.TB) and inflammatory indicators for diagnosis of active tuberculosis in patients with fever of unknown origin (FUO). @*Methods@#Patients with FUO in Tongji Hospital from Jan 1st 2014 to Feb 28th 2015 were retrospectively enrolled, and general condition, laboratory examination including T-SPOT.TB, blood routine test, procalcitonin (PCT), high sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), lactate dehydrogenase (LDH), serum ferritin (SF) and final diagnosis were collected and analyzed. @*Results@#A total of 395 hospitalized patients with FUO were retrospectively enrolled into this study, among which there were 36 (9.11%) confirmed active tuberculosis (including 7 pulmonary cases and 29 extra-pulmonary cases), 189 (47.85%) bacterial infections, 50 (12.66%) viral infections, 4 (6.32%) fungal infections, 20 (5.06%) neoplastic diseases, 51(12.91%) autoimmune diseases, 25 (6.32%) other diseases. While 20 (5.06%) patients remained un-diagnosed. The sensitivity of T-SPOT.TB for the diagnosis of active TB in patients with FUO was 80.56% (95%CI: 63.43%-91.20%), and the specificity was 83.57% (95%CI: 79.23%-87.16%). The positive predictive value was 32.95% (95%CI: 23.52%-43.89%), and the negative predictive value was 97.72% (95%CI: 95.16%-99.00%). There were significant differences in positive LDH levels (187[141, 255] U/L vs 209[160, 343] U/L) and SF levels (296.2[191.3, 494.8] g/L vs 528.1[281.1, 1 022.0] μg/L) between active tuberculosis group and bacterial infection group (χ2=77.692, H=13.442, H=16.142, all P<0.05). The combination of T-SPOT.TB and multiple inflammatory indicators obtained most valuable efficiency (AUC=0.866) for TB diagnosis. Similarly, there were significant differences in positive ESR (31[15, 78] mm/1 h vs 10[6, 19] mm/1 h), ratio of neutrophil granulocytes ([71.17±12.59]% vs [57.08±20.38]%) between active tuberculosis group and viral infection group (H=32.797, F=6.171, all P<0.05). The combination acquired most valuable efficiency (AUC=0.929). @*Conclusions@#For patients with FUO, T-SPOT.TB combined with inflammatory indicators are valuable for the diagnosis of active tuberculosis.
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Objective To investigate the expression of macrophages in the bone marrow of chronic lympho-cytic leukemia (CLL) patients and its clinical significance in the pathogenesis of CLL .Methods Fifty-eight patients with newly diagnosed CLL were selected ,including 24 cases of Binet A ,19 cases of Binet B ,15 cases of Binet C ,and 20 patients with iron deficiency anemia were selected as control group .Immunohistochemical staining was used to detect the expression of CD68+ (M1+M2 type) and CD163 (M2 type) in CLL patients . The expression differences in bone marrow tissues of CLL patients at different stages were compared . Results The numbers of CD68+ and CD163+ cells in CLL group were significantly higher than those in con-trol group (P<0 .05) ,while those in Binet C stage patients were higher than in Binet B stage patients (P<0 .05) and those in Binet B stage patients were higher than in Binet A stage patients (P<0 .05) .The progres-sion of CLL was positively correlated with the infiltration density of CD 163+ cells (P<0 .05) .Conclusion Macrophages have a high density of infiltration in the bone marrow of CLL patients ,and the infiltration densi-ty varies in different periods of CLL .With the progresses of the disease ,macrophages infiltrated into bone marrow gradually polarize to M 2 type ,w hich is relevant with the course of CLL progress .
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Objective To investigate the inhibitory effect of rhIFN-γ on human chronic myeloid leukemia cell line K562,and the impaction on the expression of CD123.Methods MTT method was used to test cell relative viability with rhIFN-γ at different concentrations.The expression of CD123 on K562 ceils was detected by flow cytometry.Results The relative inhibition of K562 cells proliferation was hampered when the cells were treated with rhIFN-γ for 72 h at the concentration of 5 x 10P ～ 108 U/L,respectively.However,rhIFN-γ at 2 x 105 U/L was benefit to K562 cells proliferation.After treatment with rhIFN-γ at 0,2 x 105 U/L and 107 U/L,the percentages of CD123 expression on K562 cells were (4.10 ± 1.46) ％,(7.2 ± 2.50) ％ as well as (21.6 ± 1.17) ％,respectively.Compared with the control group,107 U/L rhIFN-γ significantly increased the expression of CD123 on K562 cells (P＜0.05).Conclusion The effect of rhIFN-γ on the growth of K562 cells has two aspects (inhibition or proliferation),and it can increase the expression of CD 123.
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Objective To investigate the changes of IL‐1β,IL‐2 ,IL‐4 ,IL‐6 ,IL‐10 and INF‐γexpressions in bone marrow of chro‐nic myeloid leukemia(CML)patients .Methods The IL‐1β,IL‐2 ,IL‐4 ,IL‐6 ,IL‐10 and INF‐γexpression levels were detected by u‐sing flow cytometry in 30 cases of CML chronic phase(CML‐CP) ,21 cases of CML accelerated phase(CML‐AP) ,15 cases of CML blastic phase(CML‐BP) ,42 cases of CML remission after treatment and 7 cases of non‐remission .Then the detection results were compared with those in the control group .Results The expression levels of INF‐γ and IL‐2 in each CML groups were lower than those in the control group(PCML‐AP> CML‐CP ,the difference among groups had statistical significance (P0 .05) .Conclusion The changes of serum cytokines in bone marrow microenvironment of CMLpatients have certain significance to the occurrence ,development and prognosis of CML ;the de‐tection of IL‐1β,IL‐2 ,IL‐4 ,IL‐6 ,IL‐10 and INF‐γlevels in bone marrow is hopeful to provide new ideas and theoretical basis for im‐mune therapy and prognosis judgment of CML patients .
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Objective To investigate the expression of the vascular endothelial growth factor (VEGF) and mucin MUC5AC in nasal mucosa before and after chronic rhinitis - sinusitis and nasal polyps - endoscopic sinus surgery.Methods 75 cases chronic rhinitis - sinusitis and nasal polyps - endoscopic sinus surgery patients were selected as nasal polyps group and 75 cases of nasal bone fracture or epistaxis patients as the control group from January 2012 to January 2015. Took the samples of nasal polyps before surgery and the maxillary sinus mucosa specimens after surgery six weeks of nasal polyps’ patients and on the edge of the inferior turbinate mucosa specimens of the control group to detect eosinophil count by HE staining, and detect the expression of VEGF and mucin MUC5AC by immunohistochemical staining.Results The specimens eosinophils of preoperative nasal polyp group and postoperative nasal polyp group were higher than that of control group (P < 0.05), the nasal eosinophils of postoperative nasal polyp group was lower than that of preoperative nasal polyp group (P < 0.05). The expression of specimens VEGF and mucin MUC5AC area percentages in preoperative nasal polyp group and postoperative nasal polyp group were higher than that in control group (P < 0.05), the expression of nasal VEGF and mucin MUC5AC area percentages in the postoperative nasal polyp group was lower than that of preoperative nasal polyp group (P< 0.05).Conclusion Eosinophil count and the expression levels of VEGF and mucin MUC5AC of nasal mucosa in chronic rhinitis - sinusitis and nasal polyps - endoscopic sinus surgery preoperative are higher, and reduce at postoperative six weeks, VEGF and mucin MUC5AC may be involved nasal repair.
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Objective To investigate the effect of PBL combined with EBM applied in the teaching of fever of unknown origin. Methods PBL combined with EBM teaching was applied in fever of unknown origin course for 30 clinical medicine specialty(eight years) students of Tongji class of grade 2009(experiment group), while PBL teaching was applied in fever of unknown origin course for 30 clinical medicine specialty (eight years) students of Tongji class of grade 2008 (control group). After teaching, the theory examination for both basic knowledge and case analysis was organized for all students of both groups. At the same time the questionnaire survey was conducted to 30 students of grade 2009 to evaluate the teaching effect. The results were assessed by using SPSS 18.0 statistical software for the T-test of the experimental group and the control group.Inspection level was α=0.05. Results The theory test score of students in the experimental group was (93.5±3.2) point, signifi-cantly higher than that of the students in the control group(84.7±2.8). There was statistically signifi-cant difference between the scores of the two groups of students (P=0.00). Survey results showed 19 students ( 63 . 33%) thought that the development of PBL teaching combined with evidence-based medicine teaching had its necessity, and 16 students(53.33%) thought that the teaching method im-proved their clinical thinking ability of logical reasoning. Conclusion The concept of PBL combined with EBM has achieved significant resultsinthe teaching offever of unknown origin, and it is necessary to carry out this teaching mode in medical colleges with certain teaching strength.
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Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.
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Animales , Ratones , Línea Celular , Citocinas , Alergia e Inmunología , Mediadores de Inflamación , Alergia e Inmunología , Mastocitos , Alergia e Inmunología , Microbiología , FN-kappa B , Alergia e Inmunología , Proteína Adaptadora de Señalización NOD2 , Alergia e Inmunología , Staphylococcus aureus , FisiologíaRESUMEN
In order to investigate the role of the MexA-MexB-OprM efflux pump system in the pathogenesis of Pseudomonas aeruginosa (PA)-induced pulmonary infection, pulmonary infection models were established by intratracheal injection of K767 (wild type), nalB (MexA-MexB-OprM up-regulated mutant), and ΔmexB (knockout) strains, separately. All mice were treated with Meropenem (intraper Δ itoneal injection, 100 mg/kg body weight, twice every day), and strain-related pathology, bacteria count, cytokine level, myeloperoxidase (MPO, indicator of neutrophil recruitment) activity, and macrophage inflammatory protein-2 (MIP-2) expression were evaluated at early (3rd day post-infection) and late (7th and 14th day post-infection) stages of infection. E-test showed that ΔmexB was more significantly Δ sensitive to panipenan (ETP), meropenem (MP) and imipenem (IP) than K767 and nalB strains. There was no significant difference in sensitivity to cefepime (TM) among the three stains. In contrast to the K767 and nalB groups, the ΔmexB group showed decreased bacteria burden over time and less exte Δ nsive pathological change. Additionally, MPO activity and levels of inflammatory cytokines (IL-1b, IL-12, and TNF-α) were increased at the early stage (day 3) and decreased at the later stage (day 14). Serum MIP-2 expression level was steadily increased in all three groups from early to late stages, but significantly higher in ΔmexB group than in K767 and nalB groups ( Δ P<0.05). In conclusion, the MexA-MexB-OprM efflux pump system might play an important role in PA-induced chronic pulmonary infection. High expression of the MexA-MexB-OprM efflux pump could increase antibacterial resistance and promote infection.
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Animales , Ratones , Proteínas de la Membrana Bacteriana Externa , Metabolismo , Pulmón , Microbiología , Proteínas de Transporte de Membrana , Metabolismo , Ratones Endogámicos BALB C , Infecciones por Pseudomonas , Metabolismo , Microbiología , Pseudomonas aeruginosa , MetabolismoRESUMEN
Objective To investigate the efficacy of small interfering RNA against Pseudomonos aeruginosa expressing MexA-MexB-OprM multidrug efflux pump in vivo.Methods Two short hairpin (sh)RNA expression vectors targeting the MexB gene,and negative controls,were designed,synthesized,and electrotransformed into the P.aeruginosa strain PAO1.The in vivo therapeutic efficacy of the MexB small interfering (si)RNAs was determined by infecting a murine model of chronic P.aeruginosa lung infection (1 × 107 CFU/ml).The mice were killed on day 3,5 and 7 after infection with the Pseudomonas aeruginosa strains.Results In the murine infection model,treatment with MexB-siRNAs led to significantly reduced bacteria burden of the bellows by day 5 and 7 post-infection,and reduced the P.aeruginosa-induced pathological changes.In addition,MexB-siRNA2 treatment enhanced neutrophil recruitment and production of inflammatory cytokines (IL-1β,IL-12) in the early infection stage (day 3) (P＜0.05),both of which decreased by day 7.Conclusion MexB-siRNA could inhibit both mRNA expression and the activity of P.aeruginosa in vitro.siRNA was effective in reducing the bacterial load in a murine model of chronic lung infection.Targeting of MexB with siRNA appears to be a novel strategy for treating P.aeruginosa infections.
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In order to investigate the role of the MexA-MexB-OprM efflux pump system in the pathogenesis of Pseudomonas aeruginosa (PA)-induced pulmonary infection, pulmonary infection models were established by intratracheal injection of K767 (wild type), nalB (MexA-MexB-OprM up-regulated mutant), and ΔmexB (knockout) strains, separately. All mice were treated with Meropenem (intraper Δ itoneal injection, 100 mg/kg body weight, twice every day), and strain-related pathology, bacteria count, cytokine level, myeloperoxidase (MPO, indicator of neutrophil recruitment) activity, and macrophage inflammatory protein-2 (MIP-2) expression were evaluated at early (3rd day post-infection) and late (7th and 14th day post-infection) stages of infection. E-test showed that ΔmexB was more significantly Δ sensitive to panipenan (ETP), meropenem (MP) and imipenem (IP) than K767 and nalB strains. There was no significant difference in sensitivity to cefepime (TM) among the three stains. In contrast to the K767 and nalB groups, the ΔmexB group showed decreased bacteria burden over time and less exte Δ nsive pathological change. Additionally, MPO activity and levels of inflammatory cytokines (IL-1b, IL-12, and TNF-α) were increased at the early stage (day 3) and decreased at the later stage (day 14). Serum MIP-2 expression level was steadily increased in all three groups from early to late stages, but significantly higher in ΔmexB group than in K767 and nalB groups ( Δ P<0.05). In conclusion, the MexA-MexB-OprM efflux pump system might play an important role in PA-induced chronic pulmonary infection. High expression of the MexA-MexB-OprM efflux pump could increase antibacterial resistance and promote infection.
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Staphylococcus aureus (S. aureus) is an important human pathogen which can cause a chronic condition with a high relapse rate despite the aggressive antimicrobial treatment. Recent studies showed that intracellular pattern recognition receptors (including NOD) in response to bacteria or bacterial products play a proinflammatory role by activating nuclear transcription factor-κB (NF-κB). But how NOD2 mediates the proinflammatory response to S. aureus in mast cells (MCs) is unclear. So, in this study, we attempted to examine the role of NOD2 in inflammatory responses of MCs to S. aureus. P815 cells (a mouse mast cell line) were cultured. Real-time PCR was used to detect the NOD2 mRNA expression in P815 cells during S. aureus infection. The siRNA against NOD2 gene was synthesized and transfected into S. aureus-infected P815 cells. By using the methods of ELISA and flow cytometry, the effects of NOD2 gene silencing on cell phagocytosis, cytokine secretion, NF-κB activation and cell apoptosis of the S. aureus-infected P815 cells were examined. It was found that S. aureus infection could increase the expression of NOD2 mRNA in P815 cells. NOD2 gene interference in P815 cells reduced the number of S. aureus engulfed by P815 cells, the level of cytokines and the activation of NF-κB. In addition, S. aureus could induce the apoptosis of P815 cells, but NOD2 gene silencing did not affect the cell apoptosis rate. Our data suggested that NOD2 plays a key role in pathogen recognition, signal transduction, and NF-κB activation in the inflammatory responses of MCs infected by S. aureus.
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Objective To identify the efficacy small interfering RNA against Pseudomonas aeruginosa expressing MexA-MexB-OprM efflux pumps.Methods Four siRNA ( siRNA1,siRNA2,siRNA3 and siRNA4) against mexB gene were designed and prepared by electricity transference in vitro.MICs of antibiotic combined with efflux pump inhibitors against multiple resistant strain PAO1 and PAO3 were determined by E-test method.The mRNA expression levels of efflux pump gene (mexB) were quantified by real time fluorescent quantitative PCR.Results siRNA expression vectors were constructed success by enzyme cut method.48 after PAO1 and multiple drug resistant PAO3 transfected with siRNA4,the sensibilities to antibiotic were enhanced.48 after PAO1 and multiple drug resistant PAO3 transfected with siRNAl,siRNA2 and siRNA3,the sensibilities to antibiotic didn't change obviously.48 after PAO1 and multiple drug resistant PAO3 ttransfected with siRNA4,the expression level of mexB was decreased obviously (P ＜ 0.05 ).48 after PAO1 and multiple drug resistant PAO3 transfected with siRNA1,siRNA2 and siRNA3,the expression level of mexB didn't change obviously.Conclusion siRNA against Pseudomonas aeruginosa expressing MexA-MexB-OprM efflux pumps enhanced the sensibility to antibiotic and inhibited the expression of mexB gene.Our results demonstrate the using RNAi may be potential targets for novel therapies directed against treatment of antibiotic-resistant infections.
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Objective To investigate the effect of pvdQ(PA2385)gene on Pseudomonas aeruginosa swarming motility.Methods The plasmid pME6032 with pvdQ gene was constructed and identified,then transformed into Pseudomonas aeruginosa PAO1 using the eleetroporation to build pvdQ-overexpression strain.The pME6032-PAO1 strain was constructed with the same method.The cloning plasmid pEX18Gm containing sacB was successfully used to construct unmarked deletion mutant of pvdQ gene and pvdQ mutant strain. Bacteria were inoculated in LB and were cultured overnight.The clones were measured for the diameter of the swarming zone.The statistical analysis was done using one-factor ANOVA.Results Strains of pvdQ-overexpression and pvdQ-mutant were successfully constructed and confirmed by polymerase chain reaction(PCR).The four strains were compared for the swarming motility by changes in diameter:PAO1(20.52±1.80)mm,pME6032-PAO1 strain(19.39±2.10)mm,pvdQ-overexpression strain(51.20±2.16)mm,pvdQ-mutant strain(3.30±0.55)mm.The diameter of pME6032-PAO1 strain was not significantly different from that of wild strain PAO1(t=-0.1493,P>0.05).However,the diameter of pvdQ(Q-mutant strain was significantly shorter than that of wild strain PAO1(t=2.8525,P<0.05).while the diameter of pvdQ-overexpression strain was longer than that of the wild strain PAO1(t=1.4230,P<0.05).Conclusions pvdQ gene may be involved in regulating the swarming motility of Pseudomonas aeruginosa,which can promote Pseudomonas aeruginosa swarming motility.
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Objective To investigate the effects of NOD2 on inflammatory responses of macrophages to Staphylococcus aureus. Methods Real-time RT-PCR detected NOD2 gene expression of macrophages infected by S. aureus. Synthesis of siRNA against NOD2 and interfere with macrophages, observed the effects of NOD2 gene silencing to phagocytosis of 5. aureus, cytokine secretion, activation of nuclear transcription factors, cell apoptosis of the macrophages infected by S. aureus using F.I .IS A, flow cytometry etc. Results S. aureus infection of macrophages can cause increased expression of intracellular NOD2. NOD2 gene silencing of macrophage lead to the decreased ability of phagocytosis with S. aureus, the lower levels of cytokines secretion, deficiencies of NF-κB activation. S. aureus can cause macrophage apoptosis, with the apoptosis rate increased with time. Conclusion The intracellular pattern recognition receptor NOD2 play a key role in pathogen recognition, signal transduction, activation of nuclear transcription factors in the process of macrophages infected by S. aureus.
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ObjectiveTo investigate the alteration of MexB protein expression by plasmid containing siRNA template strand was transformed into Pseudomonas aeruginosa.Methods siRNA molecules specifically against mexB were designed and ligated into pGPU6/GFP/Neo vector to construct the recombinant plasmid pGPU6/GFP/Neo-siRNA.MexB gene was cloned into expression vector pET22b+ to construct plasmid pET22b+/mexB,the recombinant expression plasmid was transformed into E.coli BL21 (DE3)plysS and protein MexB was induced to express,then purified protein MexB was used to prepare specific antibodies in rabbits.The plasmids with siRNA molecules specifically against mexB were transformed into wild type strain,clinical multiresistant strain and mexB overexpression strain of Pseudomonas aeruginosa by electroporation respectively,and the changes of the expression of MexB were detected in 8,12,24 h respectively by Western blot.ResultspGPU6/GFP/Neo-siRNA was constructed successfully.Protein MexB was expressed successfully and the rabbit polyclonal antibodies against MexB was prepared well.The gene silence of mexB by siRNA molecules was effective in the three strains of Pseudomonas aeruginosa,but it depended on the silencing time.ConclusionThe expression of MexB was reduced in 8 h and 12 h,but in 24 h,the expression was unchanged.
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Objective To investigate whether Pseudomonas aeruginosa pvdQ( PA2385 ) gene reveals altered antibiotic susceptibility under swarming conditions. Methods The plasmid pME6032 with pvdQ gene was constructed and identified, then transformed into Pseudomonas aeruginosa PAO1 by the electroporation, building pvdQ overexpression strain. Using the same method building pME6032-PAO1 strain.Bacteria were inoculated in LB overnight , measuring the colony diameter of the swarming zone . Results Strains of pvdQ overexpression was successfully constructed by real-time PCR. Comparison of two strains of the swarming motility of change in diameter: The result showed that PAO1 and pvdQ overexpression strains can both improve the antibiotics resistance. Swarmer cells of pvdQ overexpression strain exhibited a 2- to 4-fold increase in antibiotic resistance toward ceftazidime,ciprofloxacin, meropenem and polymyxin B compared to PAO1 on BM2-swarming agar plates. Conclusion pvdQ gene played an important role in elevating the antibiotics resistance, which through prarticipated in the swarmer cell differentiation.
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Objective To investigate the effect of quorum sensing autoinducer 3OC12-HSL of Pseudomonas aeruginosa on the apoptosis of Caco-2 cells and its mechanism. Methods Caco-2 cells were incubated with 3OC12-HSL for 4 h and then examined by MTT method for cytoactivities. Flow cytometry was used to analyze apoptosis rate of Caco-2 cells. Expression of apoptosis associated proteins p-p38/MAPK and NF-κB were detected by Western blot. Results After exposure to 3OC12-HSL for 4 h, cytoactivities of Caco-2 cells was reduced(P<0.05) with dose-dependent pattern, and higher dose of 3OC12-HSL leaded to increasing apoptosis rate of Caco-2 cells(P<0.05). 3OC12-HSL raised expression of apoptosis associated proteins p-p38/MAPK and NF-κB detected by Western blot. Conclusion Quorum sensing autoinducer 3OC12-HSL can effect cytoactivities of Caco-2 cells and may induce its apoptosis by enhancing the expression of p-p38/MAPK and NF-κB protein.
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Objective To evaluate the results of rotary self-locking intramedullary nail (RSIN) for treating long tubular bone fracture of extremities, and discuss the current problems. Methods One hundred and twenty-two patients with long tubular bone fracture of extremities,including 59 femoral fractures,57 tibial fractures and 6 humeral fractures,who had been treated by RSIN were retrospectively investigated. Results All of the patients achieved clin-ical healing,with an average time of 24 weeks. Nobody was found to appear maluniun,infection and the break of inter-nal fixture. Internal fixations were removed after the fracture healing,with an average time of 14 months. It was diffi-cult to remove the internal fixations in 5 cases, and one case refractured after removing the internal fixations. Conclu-sion RSIN has the advantages such as easy operation,less trauma,no pendulum effect,early motion after operation and so on, except the characters of general interlocking intramedullary nail such as anti-rotation, anti-crispition and anti-displacement.