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Uninfected Controls (uninfected + control)
Selected AbstractsDOES THE CYTOSKELETON OF INTESTINAL EPITHHELIAL CELLS FUNCTION AS A CELLULAR ALARM TO IDENTIFY THE E. COLI INFECTIONJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2001Zhe Li Intestinal epithelial cells play an important role in regulating host immunity in response to intestinal infection. Pathogenic bacteria (EPEC and EHEC) cause profound cytoskeletal rearrangement in intestinal epithelial cells during attachment or invasion. Rearrangement of cytoskeletal proteins could be a signal to up-regulate host defence response. Aims, To determine the role of actin cytoskeleton and microtubles in IL-8 mRNA response to E. coli infection. Methods, T84 cell monolayers in 6-well plates were infected with HB101, EPEC and EHEC (105 CFU/well) and compared with uninfected control at 3, 6 and 12 h post infection. Control and infected monolayers were treated with nocodazole (Noc, microtubule disrupter, 30 mm), taxol (Tax, microtubule stabiliser, 10 mm), cytochalasin D (CytoD, actin depolymeriser, 100 nm) and Jasplakinolide (Jasp, actin polymeriser, stabilise actin filaments, 1 mm) and studied 6 h post infection. IL-8 gene expression was measured by semiquantitative RT,PCR in control and uninfected monolayers with and without drug treatment and IL8 protein secretion by ELISA. The morphology of F-actin and ,-tubulin was examined by FITC-phaloidin staining (FAS), immunohistochemistry and confocal microscopy. Results, IL-8 mRNA and IL-8 were increased by infection with all bacterial strains at 3 and 6 h but both IL-8 mRNA and IL-8 in EHEC and EPEC infection were decreased compared with control and HB101 at 12 h. Disruption of microfilaments by Noc increased IL-8 (2.7 fold) while preservation of microfilaments by Tax inhibited IL8 response (0.5 fold) to HB101 infection only. CytoD decreased (0.1,0.5 fold) IL8 expression at all time points in all infections while stabilising actin by Jasp markedly increased the IL8 response (2,6 fold) in control, HB101, EHEC and EPEC at 3 and 6 h. CytoD inhibited Noc-induced IL8 gene expression. Confocal microscopy demonstrated that CytoD and Noc caused major morphological damage to the actin and ,-tubulin by 6 h. Similar changes were also observed in EPEC and EHEC infection at 12 h but not HB101. Jasp preserved actin stress filaments in both EPEC and EHEC. Conclusions, Disruption of microtubules and exogenous rearrangement of actin by pathogenic organism may be primary stimuli to up-regulate proinflammatory cytokine gene expression. Preservation of actin filaments is required for this response and may be necessary for signal transduction to the nucleus. [source] Modulation of the innate immune response of rohu Labeo rohita (Hamilton) by experimental freshwater lice Argulus siamensis (Wilson) infectionAQUACULTURE RESEARCH, Issue 9 2010Shailesh Saurabh Abstract The study was undertaken to determine the modulation in innate immune response of rohu (Labeo rohita) during experimental freshwater lice Argulus siamensis infection. Results showed that serum ,-2 macroglobulin (,-2M) activity, ceruloplasmin level and alternative complement activity were significantly (P<0.05) lower in fish at different degrees of lice infection in comparison with uninfected control. No significant difference (P>0.05) in haemagglutination titre was observed in fish with low- and high-degree lice infections as compared with uninfected control. The serum lysozyme level was significantly (P<0.05) lower in low degree of lice infection as compared with control fish. The total serum antiprotease, myeloperoxidase activity and total protein level were not significantly different (P>0.05) in different degrees of lice-infected fish with respect to the control fish. The study indicated that A. siamensis infection modulated the immune system of rohu by suppressing the ,-2M, serum complement activities and ceruloplasmin level and through induction of stress response. The baseline data obtained in the present study have tremendous importance in understanding the susceptibility of rohu to different degrees of parasitosis and might be useful in controlling this dreaded ectoparasitic infection in fish. [source] Relationships between cagA, vacA, and iceA genotypes of Helicobacter pylori and DNA damage in the gastric mucosaENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2004Marcelo S.P. Ladeira Abstract Helicobacter pylori (H. pylori) is believed to predispose carriers to gastric cancer by inducing chronic inflammation. The inflammatory processes may result in the generation of reactive oxygen and nitrogen species that damage DNA. In this study, we investigated the relationships between DNA damage in the gastric mucosa and cagA, vacA, and iceA genotypes of H. pylori. The study was conducted with biopsies from the gastric antrum and corpus of 98 H. pylori -infected and 26 uninfected control patients. H. pylori genotypes were determined by PCR and DNA damage was measured in gastric mucosal cells by the Comet assay (single cell gel electrophoresis). All patients were nonsmokers, not abusing alcohol, and not using prescription or recreational drugs. Levels of DNA damage were significantly higher (P < 0.0001) in the H. pylori -infected patients than in uninfected patients. In comparison with the level of DNA damage in the uninfected controls, the extent of DNA damage in both the antrum (OR = 8.45; 95% CI = 2.33,37.72) and the corpus (OR = 6.55; 95% CI = 2.52,17.72) was related to infection by cagA+/vacAs1m1 and iceA1 strains. The results indicate that the genotype of H. pylori is related to the amount of DNA damage in the gastric mucosa. These genotypes could serve as biomarkers for the risk of extensive DNA damage and possibly gastric cancer. Environ. Mol. Mutagen. 44:91,98, 2004. © 2004 Wiley-Liss, Inc. [source] Quantitative analysis of anti,hepatitis C virus antibody,secreting B cells in patients with chronic hepatitis C,HEPATOLOGY, Issue 1 2006Takeji Umemura To investigate the quantitative characteristics of humoral immunity in patients with hepatitis C, we established an enzyme-linked immunosorbent spot (ELISpot) assay for detection of anti,hepatitis C virus (HCV)-secreting B cells. Receiver operating characteristic curve analysis demonstrated 100% specificity and 58% to 92% sensitivity for detecting B-cell responses to NS5b, NS3, E2, and core antigens. The median sum of anti-HCV,secreting B cells to all HCV antigens tested was significantly higher in 39 patients with chronic hepatitis C (47.3 spot forming cells [SFCs]/106 peripheral blood mononuclear cells [PBMCs]) than in 9 recovered subjects (15.3 SFCs/106 PBMCs; P = .05) or 11 uninfected controls (5.3 SFCs/106 PBMCs; P < .001); the significant difference (P = .018) in chronic versus recovered patients was in reactivity to nonstructural antigens NS3 and NS5b. Anti-HCV immunoglubulin M (IgM),secreting B cells were also readily detected and persisted decades into HCV infection; there was no difference in IgM-positive cells between chronic and recovered patients. ELISpot reactivity to genotype 1,derived antigens was equivalent in patients of genotypes 1, 2, and 3. There was significant correlation between the numbers of anti-HCV IgG-secreting B cells and serum aminotransferase and to the level of circulating antibody. In conclusion, ELISpot assays can be adapted to study B-cell as well as T-cell responses to HCV. Measurement at the single-cell level suggests that humoral immunity plays a minor role in recovery from HCV infection and that B-cell immunity is strongest in those with persistent infection. (HEPATOLOGY 2005.) [source] Kinetics of lactate metabolism after submaximal ergometric exercise in HIV-infected patientsHIV MEDICINE, Issue 5 2004A-M Bauer Objectives It is unknown whether high levels of lactate result from enhanced production or decreased degradation. We therefore investigated differences in the kinetics of plasma lactic acid in HIV-infected patients receiving or not receiving highly active antiretroviral therapy (HAART) and in uninfected controls after submaximal ergometric exercise. Methods Ten healthy controls, 11 HIV-infected therapy-naïve patients, 15 HIV-infected patients on HAART with normal baseline lactate levels, and nine HIV-infected patients on HAART with elevated baseline lactate levels >2 mmol/L performed 10 min of ergometric exercise, with a heart rate of 200 beats/min minus age. Lactate levels were measured at baseline, at the end of exercise and 15, 30, 45, 60 and 120 min thereafter. Results Mean baseline lactate levels were 1.4, 1.5, 1.5 and 2.8 mmol/L in the controls, the therapy-naïve patients, the patients on HAART with normal lactate levels and the patients on HAART with elevated lactate levels, respectively. Maximum lactate levels after exercise were similar in all groups (9.7, 9.4, 9.0 and 10.1 mmol/L, respectively). Significant differences were found in the slope of lactate decline between controls and untreated individuals (P=0.038) and between patients on HAART with normal baseline lactate and patients on HAART with elevated baseline lactate (P=0.028). Conclusions Differences in lactate metabolism do exist between healthy controls and HIV-infected therapy-naïve individuals. Thus, HIV infection in itself may influence lactate levels. Elevated baseline lactate levels are associated with a delayed decline of lactate after exercise. These results could be explained by impaired lactate clearance. Lactate production upon exercise does not seem to be affected by baseline lactate levels. [source] Expression of CD8, identifies a distinct subset of effector memory CD4+ T lymphocytesIMMUNOLOGY, Issue 2 2006Iole Macchia Summary Circulating CD4+ CD8+ T lymphocytes have been described in the peripheral blood of humans and several animal species. However, the origin and functional properties of these cells remain poorly understood. In the present study, we evaluated the frequency, phenotype and function of peripheral CD4+ CD8+ T cells in rhesus macaques. Two distinct populations of CD4+ CD8+ T cells were identified: the dominant one was CD4hi CD8lo and expressed the CD8,, homodimer, while the minor population was CD4lo CD8hi and expressed the CD8,, heterodimer. The majority of CD4hi CD8,lo T cells exhibited an activated effector/memory phenotype (CCR5lo CD7, CD28, HLA-DR+) and expressed relatively high levels of granzyme B. Intracellular cytokine staining assays demonstrated that the frequency of cytomegalovirus-specific T cells was enriched five-fold in CD4hi CD8,lo T cells compared to single-positive CD4+ T cells, whereas no consistent enrichment was observed for simian immunodeficiency virus (SIV)-specific T cells. Cross-sectional studies of SIV-infected animals demonstrated that the frequency of CD4hi CD8,lo T cells was lower in wild-type SIV-infected animals compared to uninfected controls, although prospective studies of SIV-infected animals demonstrated depletion of CD4hi CD8,lo lymphocytes only in a subset of animals. Taken together, these data suggest that CD4+ T cells expressing CD8, represent an effector/memory subset of CD4+ T cells and that this cell population can be depleted during the course of SIV infection. [source] Cytokine profiling of pulmonary aspergillosisINTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 4 2006H. Sambatakou Summary Aspergillus fumigatus is ubiquitous and yet causes invasive, chronic and allergic disease of the lung. Chronic cavitary pulmonary aspergillosis (CCPA) is a slowly destructive form of pulmonary aspergillosis, without immunocompromise. We hypothesized that CCPA cytokine gene polymorphisms would differ from patients with allergic bronchopulmonary aspergillosis (ABPA) and uninfected controls. We have profiled functional cytokine gene polymorphisms for interleukin (IL)-10, IL-15, transforming growth factors (TGF)-,1, tumour necrosis factor (TNF)-, and interferon (IFN)-, in patients with CCPA (n = 24) who were compared with other forms of aspergillosis (mostly ABPA) (n = 15) and with ethnically matched controls (n = 65,330). Results are described with reference to the high-producing genotype in each case. Susceptibility to aspergillosis (all patients compared with normal controls) was associated with higher frequency of the IL-15 +13689*A allele (OR = 2.37, P = 0.0028) and A/A genotype (,2 = 10.31, P < 0.001), with a lower frequency of the TNF-,,308*A/A genotype (,2 = 11.05, P < 0.01). Within the aspergillosis patients, CCPA is associated with lower frequency of the IL-10 ,1082*G allele (OR = 0.38, P = 0.0006) and G/G genotype (,2 = 22.45, P < 0.001) and with a lower frequency of the TGF-,1 +869 *T allele (OR +0.42, P < 0.0029) and T/T genotype (,2 = 17.82, P < 0.001) compared with non-CCPA patients and normal controls. Patients infected with Aspergillus appear to be higher producers of IL-15, a Th2-promoting cytokine, and lower producers of TNF-,, a cytokine central in protective responses. CCPA occurs in patients who are genetically lower producers of both IL-10 and TGF-,1. As these cytokines are regulatory and anti-inflammatory, CCPA may be a consequence of poor inflammatory response control in the lung. [source] Risk Factors for Surgical Site Infections in Older PeopleJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2006Keith S. Kaye MD OBJECTIVES: To identify risk factors for surgical site infection (SSI) in older people and to test a priori hypotheses regarding particular variables and SSI risk. DESIGN: Case-control study. SETTING: Duke University Medical Center and seven community hospitals in North Carolina and Virginia. PARTICIPANTS: Elderly patients (,65) who underwent surgery between 1991 and 2002 at the study hospitals. Cases were elderly patients with SSI; controls were elderly operative patients without SSI. Infection control practitioners prospectively identified patients. MEASUREMENTS: Data were collected retrospectively. Case patients who developed SSI were compared with control patients who did not develop SSI. RESULTS: Five hundred sixty-nine SSI cases were identified, and 589 uninfected controls were selected. In multivariate analysis, independent predictors of SSI included obesity (odds ratio (OR)=1.77, 95% confidence interval (CI)=1.34,2.32), chronic obstructive pulmonary disease (COPD) (OR=1.66, 95% CI=1.17,2.34), and a wound class classified as contaminated or dirty (OR=1.65, 95% CI=1.01,2.72). Having private insurance was associated with lower risk (OR=0.29, 95% CI=0.12,0.68). CONCLUSION: This study identified several independent predictors of SSI in older people, including comorbid conditions (COPD and obesity), perioperative variables (wound class), and socioeconomic factors (private insurance, which was associated with lower risk). The results from this study can be used to design and implement interventions for SSI prevention in high-risk older people. [source] Development of recombinant OmpA and OmpB proteins as diagnostic antigens for rickettsial diseaseMICROBIOLOGY AND IMMUNOLOGY, Issue 7 2009Eun-Ju Do ABSTRACT In this study the diagnostic potential of Rickettsia conorii recombinant antigens was analyzed. For this, site-specific PCR primers were used to clone the OmpA and OmpB genes of R. conorii into pMAL-c2X plasmids. Six fragments of OmpA and four of OmpB were expressed as fusion proteins with maltose-binding protein in Escherichia coli. OmpA1350-1784, OmpB801-1269, and OmpB1227-1634 regions from truncated proteins were selected as diagnostic candidate antigens by ELISA using control sera. ELISA results of three antigens were compared to the results obtained by using a commercial ELISA kit which contained whole OmpA and OmpB antigens from R. conorii. For this analysis, 40 serum samples taken from febrile patients and uninfected controls were tested. Of the 20 R. conorii test results which were positive with the commercial kit, 18 were shown to be positive by ELISA using OmpA1350-1784 (a sensitivity of 90%). The specificity of the ELISA was 100%; all of the 20 samples shown to be negative using the commercial kit were also negative in our assay. The sensitivities of the ELISA using the OmpB801-1269 and OmpB1227-1634 were 90% and 95%, respectively. The specificities of the OmpB801-1269 and the OmpB1227-1634 were 100% and 95%, respectively. These results suggest that specific regions of OmpA and OmpB effectively detect antibodies against R. conorii, and the truncated recombinant antigens could be used for development of diagnostic tools for rickettsial disease. [source] Candidate's Thesis: Direct Evidence of Bacterial Biofilms in Otitis Media,THE LARYNGOSCOPE, Issue 12 2001J. Christopher Post MD Abstract Objectives/Hypothesis Bacteriologic studies of otitis media with effusion (OME) using highly sensitive techniques of molecular biology such as the polymerase chain reaction have demonstrated that traditional culturing methods are inadequate to detect many viable bacteria present in OME. The presence of pathogens attached to the middle-ear mucosa as a bacterial biofilm, rather than as free-floating organisms in a middle-ear effusion, has previously been suggested to explain these observations. The suggestion has been speculative, however, because no visual evidence of such biofilms on middle-ear mucosa has heretofore been collected. The hypotheses motivating the current study were: 1) biofilms of nontypable Hemophilus influenzae will form on the middle-ear mucosa of chinchillas in an experimental model of OME, 2) these biofilms will exhibit changes in density or structure over time, and 3) biofilms are also present on tympanostomy tubes in children with refractory post-tympanostomy otorrhea. The objective of this study was to collect visual evidence of the formation of bacterial biofilms in these situations. Study Design Laboratory study of bacteriology in an animal model and on medical devices removed from pediatric patients. Methods Experimental otitis media was induced in chinchillas by transbullar injection of nontypable H. influenzae. Animals were killed in a time series and the surface of the middle-ear mucosa was examined by scanning electron microscopy (SEM) for the presence of bacterial biofilms. Adult and fetal chinchilla uninfected controls were similarly examined for comparison. In addition, tympanostomy tubes that had been placed in children's ears to treat OME and removed after onset of refractory otorrhea or other problems were examined by SEM and by confocal scanning laser microscopy for bacterial biofilms, and compared with unused control tubes. Results Bacterial biofilms were visually detected by SEM on the middle-ear mucosa of multiple chinchillas in which H. influenzae otitis media had been induced. Qualitative evaluation indicated that the density and thickness of the biofilm might increase until at least 96 hours after injection. The appearance of the middle-ear mucosa of experimental animals contrasted with that of uninjected control animals. Robust bacterial biofilms were also visually detected on tympanostomy tubes removed from children's ears for clinical reasons, in contrast with unused control tubes. Conclusions Bacterial biofilms form on the middle-ear mucosa of chinchillas in experimentally induced H. influenzae otitis media and can form on tympanostomy tubes placed in children's ears. Such biofilms can be directly observed by microscopy. These results reinforce the hypothesis that the bacterial aggregates called biofilms, resistant to treatment by antibiotics and to detection by standard culture techniques, may play a major etiologic role in OME and in one of its frequent complications, post-tympanostomy otorrhea. [source] Viral Infection Induces De Novo Lesions of Coronary Allograft Vasculopathy Through a Natural Killer Cell-Dependent PathwayAMERICAN JOURNAL OF TRANSPLANTATION, Issue 11 2009J. A. Graham Viral infections including those due to cytomegalovirus have been associated with accelerated cardiac allograft vasculopathy (CAV) in clinical trials and some animal models. Evidence demonstrating a direct causal relationship between such infections and de novo formation of coronary vascular lesions is lacking. Heterotopic murine cardiac transplants were performed in a parental to F1 combination in animals lacking both T- and B-lymphocytes (RAG,/,). Coronary vasculopathy developed almost exclusively in the presence of recipient infection with lymphocytic choriomeningitis virus but not in uninfected controls. This process was also dependent upon the presence of natural killer (NK) cells as depletion of NK cells abrogated the process. These data show that a viral infection in its native host, and not previously implicated in the production of CAV, can contribute to the development of advanced coronary vascular lesions in cardiac allotransplants in mice. These data also suggest that virus-induced CAV can develop via an NK-cell-dependent pathway in the absence of T- and B-lymphocytes. [source] 3135: Modulation of apoptotic signaling pathways to promote survival of endothelial cells by gene therapyACTA OPHTHALMOLOGICA, Issue 2010T FUCHSLUGER Purpose Corneal transplantation is the most common transplantation worldwide. Surgeons and eye banks face major problems: (1) shortage of tissue in aging populations, (2) loss of high-quality tissue due to cell loss during storage, (3) graft failure. It has been demonstrated that EC loss is mediated by the cells' intrinsic death machinery resulting in apoptosis. Identification of survival strategies could raise the availability of tissue, with a significant impact on transplantation by lowering graft rejection rate. The purpose of this study different apoptotic pathways and to determine the protective effect of the anti-apoptotic proteins bcl-xL and p35. Methods Intrinsic (mitochondria-mediated) and extrinsic (ligand-mediated) apoptotic pathways were selectively activated to provoke apoptosis of murine and human corneal endothelial cells suspensions and corneas. Gene transfer of bcl-xL or p35 was accomplished, survival of EC was determined by flow cytometry and laser scanning microscopy. Results Interestingly, we were able to determine distinct differences in cell survival enhancement depending on the type of overexpressed protein. Whereas uninfected controls showed significant EC death, gene-therapeutically treated EC demonstrated significantly increased cell survival. We will present data on the efficacy of certain anti-apoptotic proteins in select pathways. Conclusion Exploring inhibitory strategies of EC death can lead to clinically relevant survival strategies with significant impact on corneal grafting. [source] Homeostatic role of IL-7 in HIV-1 infected children on HAART: Association with immunological and virological parametersACTA PAEDIATRICA, Issue 2 2005S Resino Abstract Aim: To investigate the role of IL-7 in HIV-infected children on highly active antiretroviral therapy (HAART) and its association with laboratory parameters related to disease progression. Patients and methods: A cross-sectional study in 31 vertically HIV-infected children (median age 8.4 y) treated with HAART, and a longitudinal study in four of those same children was carried out. In both studies, viral load, CD4+ T-cell counts, thymic production of T cells by TCR rearrangement excision circles (TRECs), IL-7 plasma levels and viral phenotype were determined. Results: IL-7 levels were higher in HIV-infected children than in age-matched, uninfected controls. In addition, HIV children with CD4+ T cells between 200 and 500 T cells/mm3 had higher IL-7 levels and lower TREC values than HIV-infected children with CD4+ T cells >500 T cells/mm3. IL-7 levels were higher in children with syncytium-inducing (SI) phenotype than in those with non-syncytium-inducing (NSI) variants. During the follow-up of four HIV children, the decrease in viral load after HAART was always associated with a recovery of CD4+ T cells and TRECs, which was followed by a decrease in IL-7 returning to the levels present prior to the drop in CD4+ T cells. The four HIV-infected children had SI/X4 isolates in PBMC before HAART, and the viral phenotype switched to NSI/R5 after HAART. Conclusion: Our data suggest that IL-7 plays a key role in the maintenance of T-cell homeostasis in HIV-infected children on HAART, both through peripheral expansion and through a thymus-dependent mechanism. [source] | |||||||||||||