275 research outputs found

    Alpha-tocopherol exerts protective function against the mucotoxicity of particulate matter in amphibian and human goblet cells

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    Exposure to particulate matter (PM) in ambient air is known to increase the risk of cardiovascular disorders and mortality. The cytotoxicity of PM is mainly due to the abnormal increase of reactive oxygen species (ROS), which damage cellular components such as DNA, RNA, and proteins. The correlation between PM exposure and human disorders, including mortality, is based on long-term exposure. In this study we have investigated acute responses of mucus-secreting goblet cells upon exposure to PM derived from a heavy diesel engine. To this end, we employed the mucociliary epithelium of amphibian embryos and human Calu-3 cells to examine PM mucotoxicity. Our data suggest that acute exposure to PM significantly impairs mucus secretion and results in the accumulation of mucus vesicles in the cytoplasm of goblet cells. RNA-seq analysis revealed that acute responses to PM exposure significantly altered gene expression patterns; however, known regulators of mucus production and the secretory pathway were not significantly altered. Interestingly, pretreatment with alpha-tocopherol nearly recovered the hyposecretion of mucus from both amphibian and human goblet cells. We believe this study demonstrates the mucotoxicity of PM and the protective function of alpha-tocopherol on mucotoxicity caused by acute PM exposure from heavy diesel engines

    The farnesoid X receptor negatively regulates osteoclastogenesis in bone remodeling and pathological bone loss

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    Farnesoid X receptor (FXR, NR1H4) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. Since the role of FXR in osteoclast differentiation remains ill-defined, we investigated the biological function of FXR on osteoclastogenesis, using FXR-deficient mice. We demonstrated that FXR deficiency increases osteoclast formation in vitro and in vivo. First, FXR deficiency was found to accelerate osteoclast formation via down-regulation of c-Jun N-terminal kinase (JNK) 1/2 expression. Increased expression of peroxisome proliferator-activated receptor (PPAR)γ and peroxisome proliferator-activated receptor gamma coactivator 1 (PGC- 1)β seems to mediate the pro-osteoclastogenic effect of FXR deficiency via the JNK pathway. In addition, we found that FXR deficiency downregulated the expression of interferon-β (IFN-β), a strong inhibitor of osteoclastogenesis, via receptor activator of nuclear factor-kappaB ligand (RANKL). We further suggested that interference of IFN-β expression by FXR deficiency impaired the downstream JAK3-STAT1 signaling pathways, which in turn increased osteoclast formation. Finally, FXR deficiency accelerated unloading- or ovariectomy-induced bone loss in vivo. Thus, our findings demonstrate that FXR is a negative modulator in osteoclast differentiation and identify FXR as a potential therapeutic target for postmenopausal osteoporosis and unloadinginduced bone loss

    Toxoplasma gondii Inhibits Apoptosis in Infected Cells by Caspase Inactivation and NF-κB Activation

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    Our experiments aimed to clarify the mechanism by which host cell apoptosis is inhibited by infection with the intracellular protozoan parasite, Toxoplasma gondii (T. gondii). Mouse spleen cells were cultured in 6-well plates with RPMI 1640/10% FBS at 37℃, in a 5% CO2 atmosphere. Apoptosis of spleen cells was induced by actinomycin-D (AD) treatment for 1 h prior to infection with T. gondii. A variety of assays were used to assess the progression of apoptosis: DNA size analysis on agarose gel electrophoresis, flow cytometry with annexin V/PI staining, and analysis of expression levels of Bcl-2 family and NF-κB mRNA and proteins by RT-PCR, Western blotting, and EMSA. Additionally, transmission electron microscopy (TEM) was performed to observe changes in cell morphology. Fragmentation of DNA was inhibited in spleen cells treated with AD and T. gondii 5 h and 18 h post infection, respectively, and flow cytometry studies showed a decreased apoptotic rates in AD and T. gondii treated spleen cells. We observed decreased expression of Bax mRNA and protein, while levels of Bcl-2 mRNA remained constant in spleen cells treated with AD and T. gondii. Caspase 3 and PARP were inactivated in cells treated with AD and T. gondii, and increased levels of cleaved caspase 8 were also observed. Analysis of EMSA and Western blot data suggests that activation of transcription factor NF-κB may be involved in the blockade of apoptosis by T. gondii. TEM analysis showed nuclear fragmentation and chromatin condensation occurring in spleen cells treated with AD; however, such apoptosis-associated morphological changes were not observed in cells treated with both AD and T. gondii tachyzoites. Together, these data show that T. gondii infection inhibits AD induced apoptosis via caspase inactivation and NF-κB activation in mouse spleen cells

    Thoracic Air-leak Syndromes In Hematopoietic Stem Cell Transplant Recipients with Graft-versus-Host Disease: A Possible Sign for Poor Response to Treatment and Poor Prognosis

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    Bronchiolitis obliterans (BO) or bronchiolitis obliterans organizing pneumonia (BOOP) is one of manifestations of graft-versus-host disease (GVHD), a complication of hematopoietic stem cell transplantation (HSCT). Recently there are reports about thoracic air-leakage syndrome (TALS), but real incidence, clinical course, and implications of TALS remain unclear. Retrospective review of 18 TALS patients among 2,177 patients who received allogeneic HSCT between January 2000 to July 2007 was done. Clinical manifestations, treatments, and outcomes of TALS were reviewed. The incidence of TALS was 0.83% (18/2,177). The onset of TALS was mean 425.9±417.8 days (60-1,825 days) after HSCT, and the duration was mean 16.3±21 days (2-90 days). The most common types of TALS were spontaneous pneumothroax (n=14), followed by subcutaneous emphysema (n=6), pneumomediastinum (n=5), interstitial emphysema (n=2), and pneumopericardium (n=1). TALS persisted in six patients, who died during the same hospitalization. The 12 patients recovered from TALS, but only 2 survived, while others died due to aggravation of GVHD. TALS may complicate BO/BOOP and be an initial manifestation of BO/BOOP. TALS is hard to be resolved, and even after the recovery, patients die because of aggravation of GVHD. We suggest specifically in HSCT patients, when once developed, TALS seems hard to be cured, and as a result, be related to high fatality

    Epidemiological and Genetic Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from the Ear Discharge of Outpatients with Chronic Otitis Media

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    The origin of methicillin-resistant Staphylococcus aureus (MRSA) strains from otolaryngology outpatients has not been evaluated yet in Korea. We analyzed epidemiologic and genetic characteristics of MRSA isolates from the ear discharge of 64 outpatients with chronic otitis media in a Korean University Hospital during 2004. MRSA strains were grouped as either from the initial visit (n=33) or the follow-up visit (n=31) based on the timing of isolation. Healthcare-associated risk factors were frequently present among patients of the initial visit group, especially prior visit to primary clinic (79%) and antibiotic use (73%). SCCmec typing and multilocus sequence typing results showed that two genotypes, ST5-MRSA-II and ST239-MRSA-III, were prevalent in both the initial visit (73% vs. 24%) and the follow-up visit (55% vs. 42%). Pulsed-field gel electrophoresis identified eight types, including two major types shared by both groups. We conclude that majority of MRSA strains from ear discharge of chronic otitis media belonged to nosocomial clones that might be circulating in the community. This is the first report of the genetic analysis of MRSA strains from otolaryngology practices in Korea

    Analysis of research papers published in the Journal of the Korean Academy of Nursing-focused on research trends, intervention studies, and level of evidence in the research

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    The number of quantitative studies was greater than that of qualitative studies. There was a slight increase in the number of qualitative studies and studies including elderly populations, which reflects the recent population trend in Korea. More randomized controlled trials with a low risk of bias were needed to support more evidence-based nursing practice. Concerning the low rate of ethical consideration, stricter application of research ethics needs to be encouraged. Conclusion: The findings of this study suggest the recent trends in nursing research and the direction of nursing research and review in the Journal

    A Case of Sparganosis That Presented as a Recurrent Pericardial Effusion

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    Sparganosis is caused by a larval tapeworm of the genus Spirometra, which commonly invades subcutaneous tissue, but less frequently invades muscle, intestines, spinal cord, and the peritoneopleural cavity. The authors managed a female patient who presented with a recurrent pericardiopleural effusion and peripheral eosinophilia. The anti-sparganum-specific IgG serum level was significantly higher than normal control levels. In this patient, sparganosis was caused by the ingestion of raw frogs in an effort to control her thyroid disease. The recurrent pericardiopleural effusion and peripheral eosinophilia were controlled by 3 consecutive doses of praziquantel (75 mg/kg/day). The patient is doing well 4 years after presentation. Sparganosis should be considered a rare, but possible cause of recurrent pericardial effusion and peripheral eosinophilia. Immunoserologic testing using enzyme linked immunosorbent assays can be helpful in diagnosing human sparganosis, especially in cases without a subcutaneous lump or mass. Praziquantel is an alternative treatment for sparganosis in surgically-unresectable cases

    Atypical Pathogens as Etiologic Agents in Hospitalized Patient with Community-Acquired Pneumonia in Korea: A Prospective Multi-Center Study

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    Local epidemiologic data on the etiologies of patients hospitalized with community-acquired pneumonia (CAP) is needed to develop guidelines for clinical practice. This study was conducted prospectively to determine the proportion of atypical bacterial pathogens in adults patients hospitalized with CAP in Korea between October 2001 and December 2002. Microbiological diagnosis was determined by serology for antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila. Nucleic acid of M. pneumoniae and C. pneumoniae in respiratory samples and Legionella antigen in urine samples were detected. The study population consisted of 126 patients (71 males, 55 females), averaging 54.6 yr (SD±17.8), whose paired sera were available. An etiologic diagnosis for atypical pathogens was made in 18 patients (14.3%): C. pneumoniae 9 (7.1%), M. pneumoniae 8 (6.3%), and L. pneumophila 3 patients (2.4%). Streptococcus preumoniae and other typical pathogens were isolated from 36 patients (28.6%). Of 126 patients, 16 (12.7%) were admitted to intensive care unit and atypical pathogens were identified in 5 patients (31.3%). Initial clinical features of patients with pneumonia due to atypical, typical or undetermined pathogens were indistinguishable. We conclude that atypical pathogens should be seriously considered in hospitalized patients with CAP, when initiating empiric treatment in Korea
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