Healthcare-associated Pneumonia: Clinical Features and Retrospective Analysis Over 10 Years / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Healthcare-associated pneumonia (HCAP) is associated with drug-resistant pathogens and high mortality, and there is no clear evidence that this is due to inappropriate antibiotic therapy. This study was to elucidate the clinical features, pathogens, therapy, and outcomes of HCAP, and to clarify the risk factors for drug-resistant pathogens and prognosis.</p><p><b>METHODS</b>Retrospective observational study among hospitalized patients with HCAP over 10 years. The primary outcome was 30-day all-cause hospital mortality after admission. Demographics (age, gender, clinical features, and comorbidities), dates of admission, discharge and/or death, hospitalization costs, microbiological results, chest imaging studies, and CURB-65 were analyzed. Antibiotics, admission to Intensive Care Unit (ICU), mechanical ventilation, and pneumonia prognosis were recorded. Patients were dichotomized based on CURB-65 (low- vs. high-risk).</p><p><b>RESULTS</b>Among 612 patients (mean age of 70.7 years), 88.4% had at least one comorbidity. Commonly detected pathogens were Acinetobacter baumannii, Pseudomonas aeruginosa, and coagulase-negative staphylococci. Initial monotherapy with β-lactam antibiotics was the most common initial therapy (50%). Mean age, length of stay, hospitalization expenses, ICU admission, mechanical ventilation use, malignancies, and detection rate for P. aeruginosa, and Staphylococcus aureus were higher in the high-risk group compared with the low-risk group. CURB-65 ≥3, malignancies, and mechanical ventilation were associated with an increased mortality. Logistic regression analysis showed that cerebrovascular diseases and being bedridden were independent risk factors for HCAP.</p><p><b>CONCLUSION</b>Initial treatment of HCAP with broad-spectrum antibiotics could be an appropriate approach. CURB-65 ≥3, malignancies, and mechanical ventilation may result in an increased mortality.</p>

Feasibility of cartilage link protein of hyaluronic acid for defining radiotherapeutic target volume in a mouse model of lung tumor / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the feasibility of using cartilage link protein of hyaluronic acid (HA-CLP) for defining the tumor boundary in a mouse model of lung carcinoma.</p><p><b>METHODS</b>Lung carcinoma was induced in KM mice by chemical carcinogenesis. HA-CLP separated from bovine cartilage and purified by affinity chromatography was labeled with (125)I for autoradiography. Immunohistochemical analysis and Western blotting were used to examine the efficiency of HA-CLP in defining the boundaries of the lung tumors.</p><p><b>RESULTS</b>With autoradiography, the clearest image of lung cancer was obtained at 2 h. With immunohistochemical method, the tumor boundary was the most clearly displayed at 2 h when the strongest signals of HA-CLP was detected; Western blotting also showed the clearest bands of HA-CLP at 2 h.</p><p><b>CONCLUSION</b>HA-CLP has the immunogenicity of HABP, and can efficiently indicate lung tumor boundary in autoradiography and immunohistochemistry.</p>

Bone marrow-derived mesenchymal stem cells protect rats from endotoxin-induced acute lung injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acute lung injury (ALI) is a serious and common condition for which there are currently no specific strategies for treatment. Recent studies have suggested that bone marrow-derived multipotent mesenchymal stem cells (MSCs) may have therapeutic applications in multiple clinical disorders. We explored the biological effects of MSCs during endotoxin-induced ALI and the mechanisms involved.</p><p><b>METHODS</b>MSCs were isolated from male rat bone marrow and the ALI model was induced by intravenous endotoxin injection. Female rats were sacrificed at 6 hours, 24 hours, 4 days, 1 week and 3 weeks post-injection of MSCs or saline and the lung tissue, bronchoalveolar lavage fluid, and serum were harvested for analysis. We further evaluated the survival of the rats and examined the effects of endotoxin-induced injury on the interaction between alveolar macrophages (AMs) and MSCs in ex vivo.</p><p><b>RESULTS</b>There was a significant decrease in numbers of neutrophils in bronchoalveolar lavage fluid (P < 0.05), and myeloperoxidase activity in the lung (P < 0.01), and of TNF-α and IL-1β in serum (P < 0.05) in the MSC treated rats at 4 days. Furthermore, MSC treated rats exhibited improved survival, lower lung injury score, higher concentration of IL-10 in the serum and a reduced hydroxyproline content, but these differences were not statistically significant. Moreover, co-cultures of MSCs and AMs had significantly reduced levels of TNF-α, IL-1β and macrophage inflammatory protein (MIP)-1α and significantly increased levels of IL-10 (P < 0.05) in the culture supernatants.</p><p><b>CONCLUSIONS</b>Treatment with intravenous injection of bone marrow-derived MSCs have beneficial effects on endotoxin-induced ALI in rats. The beneficial effect might be achieved through the engraftment of differentiated MSCs in the lungs and appears derive more from their capacity to secrete soluble factors that modulate immune responses.</p>

Perfluorocarbon attenuates lipopolysaccharide-mediated inflammatory responses of alveolar epithelial cells in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Toll-like receptor-4 (TLR-4) is integrally involved in lipopolysaccharide (LPS) signaling and has a requisite role in the activation of nuclear factor-κB (NF-κB). The exact mechanisms that lend perfluorocarbon (PFC) liquids a cytoprotective effect have yet to be elucidated. Therefore we examined in an in vitro model the cytoprotective effect of PFC on LPS-stimulated alveolar epithelial cellls (AECs).</p><p><b>METHODS</b>AECs (A549 cells, human lung adenocarcinoma cell line) were divided into four groups: control, PFC, LPS and LPS + PFC (coculture group) groups. Intercellular adhesion molecule-1 (ICAM-1) was detected by ELISA, tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) were detected by radioimmunological methods. The expression of TLR-4 mRNA and protein was detected by real time PCR and Western blotting, respectively. The activation of NF-κB was detected by Western blotting (proteins of I-κBa and NF-κB p65).</p><p><b>RESULTS</b>ICAM-1, TNF-α and IL-8 were significantly increased in LPS-stimulated AECs groups. The expression of TLR-4 mRNA and protein in LPS-stimulated groups was markedly increased. Meanwhile, NF-κB was activated as indicated by the significant degradation of IκB-α and the significant release of NF-κB P65 and its subsequent translocation into the nucleus. There were no significant effects of PFC alone on any of the factors studied while the coculture group showed significant downregulation of the secretion of ICAM-1, TNF-α and IL-8, the expression of TLR-4 mRNA and the activity of NF-κB.</p><p><b>CONCLUSIONS</b>Taken together, our results demonstrate that LPS can induce AEC-related inflammatory injury via the activation of TLR-4 and subsequent activation of NF-κB. PFC is able to protect AECs from LPS-induced inflammatory injury by blocking the initiation of the LPS signaling pathway, which is indicated by the significant decrease of TLR-4 expression and NF-κB activation.</p>

Gefitinib attenuates murine pulmonary fibrosis induced by bleomycin / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Gefitinib, an inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, is an effective treatment for epithelial tumors, including non-small cell lung cancer (NSCLC), and is generally well tolerated. However, some clinical trials revealed that gefitinib exposure caused lung fibrosis, a severe adverse reaction. This study investigated the effect of gefitinib on lung fibrosis in mice.</p><p><b>METHODS</b>We generated a mouse model of lung fibrosis induced by bleomycin to investigate the fibrotic effect of gefitinib. C57BL/6 mice were injected intratracheally with bleomycin or saline, with intragastric administration of gefitinib or saline. Lung tissues were harvested on day 14 or 21 for histology and genetic analysis.</p><p><b>RESULTS</b>The histological results showed that bleomycin successfully induced lung fibrosis in mice, and gefitinib prevented lung fibrosis and suppressed the proliferation of S100A4-positive fibroblast cells. In addition, Western blotting analysis revealed that gefitinib decreased the expression of phosphorylated EGFR (p-EGFR). Furthermore, quantitative real-time PCR (qRT-PCR) demonstrated that gefitinib inhibited the accumulation of collagens I and III.</p><p><b>CONCLUSIONS</b>These results reveal that gefitinib reduces pulmonary fibrosis induced by bleomycin in mice and suggest that administration of small molecule EGFR tyrosine kinase inhibitors has the potential to prevent pulmonary fibrosis by inhibiting the proliferation of mesenchymal cells, and that targeting tyrosine kinase receptors might be useful for the treatment of pulmonary fibrosis in humans.</p>