276 research outputs found

    Strain specific transcriptional response in Mycobacterium tuberculosis infected macrophages

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    <p>Abstract</p> <p>Background</p> <p>Tuberculosis (TB), a bacterial infection caused by <it>Mycobacterium tuberculosis </it>(<it>Mtb) </it>remains a significant health problem worldwide with a third of the world population infected and nearly nine million new cases claiming 1.1 million deaths every year. The outcome following infection by <it>Mtb </it>is determined by a complex and dynamic host-pathogen interaction in which the phenotype of the pathogen and the immune status of the host play a role. However, the molecular mechanism by which <it>Mtb </it>strains induce different responses during intracellular infection of the host macrophage is not fully understood. To explore the early molecular events triggered upon <it>Mtb </it>infection of macrophages, we studied the transcriptional responses of murine bone marrow-derived macrophages (BMM) to infection with two clinical <it>Mtb </it>strains, CDC1551 and HN878. These strains have previously been shown to differ in their virulence/immunogenicity in the mouse and rabbit models of pulmonary TB.</p> <p>Results</p> <p>In spite of similar intracellular growth rates, we observed that compared to HN878, infection by CDC1551 of BMM was associated with an increased global transcriptome, up-regulation of a specific early (6 hours) immune response network and significantly elevated nitric oxide production. In contrast, at 24 hours post-infection of BMM by HN878, more host genes involved in lipid metabolism, including cholesterol metabolism and prostaglandin synthesis were up-regulated, compared to infection with CDC1551.</p> <p>In association with the differences in the macrophage responses to infection with the 2 <it>Mtb </it>strains, intracellular CDC1551 expressed higher levels of stress response genes than did HN878.</p> <p>Conclusions</p> <p>In association with the early and more robust macrophage activation, intracellular CDC1551 cells were exposed to a higher level of stress leading to increased up-regulation of the bacterial stress response genes. In contrast, sub-optimal activation of macrophages and induction of a dysregulated host cell lipid metabolism favored a less stressful intracellular environment for HN878. Our findings suggest that the ability of CDC1551 and HN878 to differentially activate macrophages during infection probably determines their ability to either resist host cell immunity and progress to active disease or to succumb to the host protective responses and be driven into a non-replicating latent state in rabbit lungs.</p

    Chitosan-Genipin Microspheres for the Controlled Release of Drugs: Clarithromycin, Tramadol and Heparin

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    The aim of this study was to first evaluate whether the chitosan hydrochloride-genipin crosslinking reaction is influenced by factors such as time, and polymer/genipin concentration, and second, to develop crosslinked drug loaded microspheres to improve the control over drug release. Once the crosslinking process was characterized as a function of the factors mentioned above, drug loaded hydrochloride chitosan microspheres with different degrees of crosslinking were obtained. Microspheres were characterized in terms of size, morphology, drug content, surface charge and capacity to control in vitro drug release. Clarithromycin, tramadol hydrochloride, and low molecular weight heparin (LMWH) were used as model drugs. The obtained particles were spherical, positively charged, with a diameter of 1–10 μm. X-Ray diffraction showed that there was an interaction of genipin and each drug with chitosan in the microspheres. In relation to the release profiles, a higher degree of crosslinking led to more control of drug release in the case of clarithromycin and tramadol. For these drugs, optimal release profiles were obtained for microspheres crosslinked with 1 mM genipin at 50 ºC for 5 h and with 5 mM genipin at 50 ºC for 5 h, respectively. In LMWH microspheres, the best release profile corresponded to 0.5 mM genipin, 50 ºC, 5 h. In conclusion, genipin showed to be eligible as a chemical-crosslinking agent delaying the outflow of drugs from the microspheres. However, more studies in vitro and in vivo must be carried out to determine adequate crosslinking conditions for different drugs

    A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP-KLH Immunized Mice

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    This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4-dinitrophenylated keyhole limpet protein (DNP-KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non-acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36-PA (IM + plain acupuncture at ST36), ST36-LEA (IM + low frequency (1 Hz) EA at ST36), ST36-HEA (IM + high frequency (120 Hz) EA at ST36), NA-LEA (IM + low frequency (1 Hz) EA at non-acupoint) and NA-HEA (IM + high frequency (120 Hz) EA at non-acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP-KLH specific IgE, IL-4 and IFN-γ levels were measured at the end of the experiment. The results of this study showed that the IgE and IL-4 levels were significantly suppressed in the ST36-LEA and ST36-HEA groups, but not in the NA-LEA and NA-HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36-LEA and ST36-HEA groups. Taken together, these results suggest that EA stimulation-induced immunomodulation is not frequency dependent, but that it is acupoint specific

    Pharmacologic inhibition of host Phosphodiesterase-4 improves isoniazid-Mediated clearance of Mycobacterium tuberculosis

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    The lengthy duration of multidrug therapy needed to cure tuberculosis (TB) poses significant challenges for global control of the disease. Moreover, chronic inflammation associated with TB leads to pulmonary damage that can remain even after successful cure. Thus, there is a great need for the development of effective shorter drug regimens to improve clinical outcome and strengthen TB control. Host-directed therapy (HDT) is emerging as a novel adjunctive strategy to enhance the efficacy and shorten the duration of TB treatment. Previously, we showed that the administration of CC-3052, a phosphodiesterase-4 inhibitor (PDE4i), reduced the host inflammatory response during Mycobacterium tuberculosis (Mtb) infection and improved the antimicrobial efficacy of isoniazid (INH) in both the mouse and rabbit models. In the present study, we evaluated the pharmacokinetics and explored the mechanism underlying the efficacy of a more potent PDE4i, CC-11050, as adjunct to INH treatment in a mouse model of pulmonary Mtb infection. Genome-wide lung transcriptome analysis confirmed the dampening of inflammation and associated network genes that we previously reported with CC-3052. Consistent with the reduction in inflammation, a significant improvement in Mtb control and pathology was observed in the lungs of mice treated with CC-11050 plus INH, compared to INH alone. This important confirmatory study will be used to help design upcoming human clinical trials with CC-11050 as an HDT for TB treatment

    Pharmacologic inhibition of host Phosphodiesterase-4 improves isoniazid-Mediated clearance of Mycobacterium tuberculosis

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    The lengthy duration of multidrug therapy needed to cure tuberculosis (TB) poses significant challenges for global control of the disease. Moreover, chronic inflammation associated with TB leads to pulmonary damage that can remain even after successful cure. Thus, there is a great need for the development of effective shorter drug regimens to improve clinical outcome and strengthen TB control. Host-directed therapy (HDT) is emerging as a novel adjunctive strategy to enhance the efficacy and shorten the duration of TB treatment. Previously, we showed that the administration of CC-3052, a phosphodiesterase-4 inhibitor (PDE4i), reduced the host inflammatory response during Mycobacterium tuberculosis (Mtb) infection and improved the antimicrobial efficacy of isoniazid (INH) in both the mouse and rabbit models. In the present study, we evaluated the pharmacokinetics and explored the mechanism underlying the efficacy of a more potent PDE4i, CC-11050, as adjunct to INH treatment in a mouse model of pulmonary Mtb infection. Genome-wide lung transcriptome analysis confirmed the dampening of inflammation and associated network genes that we previously reported with CC-3052. Consistent with the reduction in inflammation, a significant improvement in Mtb control and pathology was observed in the lungs of mice treated with CC-11050 plus INH, compared to INH alone. This important confirmatory study will be used to help design upcoming human clinical trials with CC-11050 as an HDT for TB treatment

    A Survey of Diabetic Educators and Patients for the Revision of Korean Food Exchange Lists

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    BackgroundFood exchange lists are one of the main methods of nutritional education. However, Korean food exchange lists have not been revised since 1994. Therefore, we surveyed the opinions of diabetes educators and patients with diabetes regarding the need for revision of the current food exchange lists.MethodsFor two weeks beginning on 10 March 2008, a 12-item questionnaire regarding the opinion and need for revision of the current food exchange lists was e-mailed to diabetes educators nationwide. Another 15-question survey was administered to patients with diabetes in 13 hospitals located in the Seoul and Gyeonggi regions of Korea.ResultsWe obtained survey responses from 101 diabetes educators and 209 patients; 65 (64.3%) of the educators answered that the current food exchange lists should be revised. The items that needed revision were the glycemic index, addition of new foods and reaffirmation of exchange standard amounts. The patients demanded specific education about choosing appropriate foods, a balanced meal plan, proper snacks, and dining intake.ConclusionOur survey results demonstrate the need to revise the Korean food exchange lists. This process should focus on glycemic index, the addition of new foods and reconfirmation of one exchange reference unit

    Association of pre-operative medication use with post-operative delirium in surgical oncology patients receiving comprehensive geriatric assessment

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    This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Abstract Background Older patients undergoing surgery tend to have a higher frequency of delirium. Delirium is strongly associated with poor surgical outcomes. This study evaluated the association between pre-operative medication use and post-operative delirium (POD) in surgical oncology patients receiving comprehensive geriatric assessment (CGA). Methods A total of 475 patients who were scheduled for cancer surgery and received CGA from January 2014 to June 2015 were included. Pre-operative medication review through CGA was conducted on polypharmacy (≥5 medications), delirium-inducing medications (DIMs), fall-inducing medications (FIMs), and potentially inappropriate medications (PIMs). POD was confirmed by psychiatric consultation, and DSM-V criteria were used for diagnosing delirium. The model fit of the prediction model was assessed by computing the Hosmer-Lemeshow goodness-of-fit test. Effect size was measured using the Nagelkerke R2. Discrimination of the model was assessed by an analysis of the area under receiver operating curve (AUROC). Results Two models were constructed for multivariate analysis based on univariate analysis; model I included dementia and DIM in addition to age and sex, and model II included PIM instead of DIM of model I. Every one year increase of age increased the risk of POD by about 1.1-fold. DIM was a significant factor for POD after adjusting for confounders (AOR 12.78, 95 % CI 2.83-57.74). PIM was also a significant factor for POD (AOR 5.53, 95 % CI 2.03-15.05). The Hosmer-Lemeshow test results revealed good fits for both models (χ2 = 3.842, p = 0.871 for model I and χ2 = 8.130, p = 0.421 for model II). The Nagelkerke R2 effect size and AUROC for model I was 0.215 and 0.833, respectively. Model II had the Nagelkerke R2effect size of 0.174 and AUROC of 0.819. Conclusions These results suggest that pharmacists comprehensive review for pre-operative medication use is critical for the post-operative outcomes like delirium in older patients

    Event-related brain response to visual cues in individuals with Internet gaming disorder: relevance to attentional bias and decision-making

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    This study investigated attentional bias toward game-related cues in Internet gaming disorder (IGD) using electrophysiological markers of late positive potential (LPP) and identifying the sources of LPP. In addition, the association between LPP and decision-making ability was investigated. The IGD (n = 40) and healthy control (HC; n = 39) participants viewed a series of game-related and neutral pictures, while their event-related potentials (ERPs) were recorded. LPPs were calculated as the mean amplitudes between 400 and 700 ms at the centro-parietal (CP3, CP1, Cpz, CP2, and CP4) and parietal (P3, P1, Pz, P2, and P4) electrode sites. The source activations of LPP were estimated using standardized low-resolution brain electromagnetic tomography (sLORETA). In addition, decision-making ability was evaluated by the Cambridge Gambling Task. Higher LPP amplitudes were found for game-related cues in the IGD group than in the HC group. sLORETA showed that the IGD group was more active in the superior and middle temporal gyri, which are involved in social perception, than in the HC group, whereas it was less active in the frontal area. Individuals with IGD have deficits in decision-making ability. In addition, in the HC group, the lower the LPP when looking at the game-related stimuli, the better the quality of decision-making, but not in the IGD group. Enhanced LPP amplitudes are associated with emotional arousal to gaming cues and decision-making deficits in IGD. In addition, source activities suggest that patients with IGD perceive game-related cues as social stimuli. LPP can be used as a neurophysiological marker of IGD. © 2021, The Author(s).1
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