Shuangping Zhao

The pathogenesis of sepsis is complex. Mitochondrial dysfunction, which is responsible for energy metabolism, intrinsic apoptotic pathway, oxidative stress, and systemic inflammatory responses, is closely related with severe sepsis induced death. Mitochondria DNA (mtDNA) contain un-methylated cytosine phosphate guanine (CpG) motifs, which exhibit immune stimulatory capacities. The aim of this study was to investigate the role and mechanism of mtDNA release on lipopolysaccharide (LPS) induced acute lung injury (ALI) and systemic inflammation. Following LPS injection, plasma mtDNA copies peak at 8 h. Compared with wild-type (WT) mice, mtDNA in toll like receptor 4 knockout (TLR4 KO) mice were significantly decreased. MtDNA intra-peritoneal administration causes apparent ALI as demonstrated by increased lung injury score, bronchoalveolar lavage fluid (BALF) total protein and wet/dry (W/D) ratio; mtDNA injection also directly provokes systemic inflammation, as demonstrated by increased IL-1β, IL-6, high-mobility group protein B1 (HMGB1) level; while nuclear DNA (nDNA) could not induce apparent ALI and systemic inflammation. However, compared with WT mice, TLR4 KO could not protect from mtDNA induced ALI and systemic inflammation. Specific TLR9 inhibitor, ODN 2088 pretreatment can significantly attenuate mtDNA induced ALI and systemic inflammation, as demonstrated by improved lung injury score, decreased lung wet/dry ratio, BALF total protein concentration, and decreased systemic level of IL-1β, IL-6 and HMGB1. MtDNA administration activates the expression of p-P38 mitogen-activated protein kinases (MAPK) in lung tissue and specific TLR9 inhibitor pretreatment can attenuate this activation. Thus, LPS-induced mtDNA release occurs in a TLR4-dependent manner, and mtDNA causes acute lung injury and systemic inflammation in a TLR9-dependent and TLR4-independent manner.

BACKGROUND: Critically ill patients with 2009 H1N1 influenza are often treated in intensive care units (ICUs), representing significant risk of nosocomial transmission to critical care clinicians and other patients. Despite a large body of literature and guidelines recommending infection control practices, numerous barriers have been identified in ICUs, leading to poor compliance to the use of personal protective equipment (PPE). The use of PPE among critical care clinicians has not been extensively evaluated, especially during the pandemic influenza. This study examined the knowledge, attitudes, and self-reported behaviors, and barriers to compliance with the use of PPE among ICU healthcare workers (HCWs) during the pandemic influenza. METHODOLOGY/PRINCIPAL FINDINGS: A survey instrument consisting of 36 questions was developed and mailed to all HCWs in 21 ICUs in 17 provinces in China. A total of 733 physicians, nurses, and other professionals were surveyed, and 650 (88.7%) were included in the analysis. Fifty-six percent of respondents reported having received training program of pandemic influenza before they cared for H1N1 patients, while 77% reported to have adequate knowledge of self and patient protection. Only 18% of respondents were able to correctly identify all components of PPE, and 55% reported high compliance (>80%) with PPE use during patient care. In multivariate analysis, vaccination for 2009 H1N1 influenza, positive attitudes towards PPE use, organizational factors such as availability of PPE in ICU, and patient information of influenza precautions, as well as reprimand for noncompliance by the supervisors were associated with high compliance, whereas negative attitudes towards PPE use and violation of PPE use were independent predictors of low compliance. CONCLUSION/SIGNIFICANCE: Knowledge and self-reported compliance to recommended PPE use among Chinese critical care clinicians is suboptimal. The perceived barriers should be addressed in order to close the significant gap between perception and knowledge or behavior.

Approximately half of estrogen receptor (ER) positive breast tumors will fail to respond to endocrine therapy. Here we used an integrative bioinformatics approach to analyze three gene expression profiling data sets from breast tumors in an attempt to uncover underlying mechanisms contributing to the development of resistance and potential therapeutic strategies to counteract these mechanisms. Genes that are differentially expressed in tamoxifen resistant vs. sensitive breast tumors were identified from three different publically available microarray datasets. These differentially expressed (DE) genes were analyzed using gene function and gene set enrichment and examined in intrinsic subtypes of breast tumors. The Connectivity Map analysis was utilized to link gene expression profiles of tamoxifen resistant tumors to small molecules and validation studies were carried out in a tamoxifen resistant cell line. Despite little overlap in genes that are differentially expressed in tamoxifen resistant vs. sensitive tumors, a high degree of functional similarity was observed among the three datasets. Tamoxifen resistant tumors displayed enriched expression of genes related to cell cycle and proliferation, as well as elevated activity of E2F transcription factors, and were highly correlated with a Luminal intrinsic subtype. A number of small molecules, including phenothiazines, were found that induced a gene signature in breast cancer cell lines opposite to that found in tamoxifen resistant vs. sensitive tumors and the ability of phenothiazines to down-regulate cyclin E2 and inhibit proliferation of tamoxifen resistant breast cancer cells was validated. Our findings demonstrate that an integrated bioinformatics approach to analyze gene expression profiles from multiple breast tumor datasets can identify important biological pathways and potentially novel therapeutic options for tamoxifen-resistant breast cancers.

Abstract We have shown that generalized seizures produce necrotic neurons with caspase‐independent nuclear pyknosis and DNA fragmentation. In this study, we determined the time course of translocation of mitochondrial cytochrome c, apoptosis‐inducing factor, endonuclease G, lysosomal cathepsins B and D, and DNase II with respect to signs of irreversible neuronal damage. Adult male Wistar rats underwent lithium‐pilocarpine‐induced seizures lasting for 60 min, 3 hr, and 3 hr with 6‐ or 24‐hr survival periods, after which the brains were prepared for immunofluorescence microscopic examination of piriform cortex. Contrary to expectation, cytochrome c and cathepsins B and D translocated to neuronal nuclei with DNase II, endonuclease G, and apoptosis‐inducing factor within 60 min of seizure onset and persisted for 24 hr after 3‐hr seizures. After 60‐min seizures, some neurons showed translocation of the death‐promoting proteins in normal‐appearing neurons, prior to their appearance in irreversibly damaged neurons. Western blots of subcellular fractions of cytochrome c and cathepsins B and D confirmed their nuclear translocation. This is the first evidence of nuclear translocation of cathepsins B and D and the first in vivo evidence of nuclear translocation of cytochrome c. The appearance of these mitochondrial proteins and lysosomal enzymes before signs of irreversible neuronal death suggests that they could contribute to seizure‐induced nuclear pyknosis and DNA fragmentation. © 2010 Wiley‐Liss, Inc.

Background Acute kidney injury (AKI) is a significant cause of morbidity and mortality, especially in sepsis patients. Early prediction of AKI can help physicians determine the appropriate intervention, and thus, improve the outcome. This study aimed to develop a nomogram to predict the risk of AKI in sepsis patients (S-AKI) in the initial 24 h following admission.Methods Sepsis patients with AKI who met the Sepsis 3.0 criteria and Kidney Disease: Improving Global Outcomes criteria in the Massachusetts Institute of Technology critical care database, Medical Information Mart for Intensive Care (MIMIC-III), were identified for analysis. Data were analyzed using multiple logistic regression, and the performance of the proposed nomogram was evaluated based on Harrell’s concordance index (C-index) and the area under the receiver operating characteristic curve.Results We included 2917 patients in the analysis; 1167 of 2042 patients (57.14%) and 469 of 875 patients (53.6%) had AKI in the training and validation cohorts, respectively. The predictive factors identified by multivariate logistic regression were blood urea nitrogen level, infusion volume, lactate level, weight, blood chloride level, body temperature, and age. With the incorporation of these factors, our model had well-fitted calibration curves and achieved good C-indexes of 0.80 [95% confidence interval (CI): 0.78–0.82] and 0.79 (95% CI: 0.76–0.82) in predicting S-AKI in the training and validation cohorts, respectively.Conclusion The proposed nomogram effectively predicted AKI risk in sepsis patients admitted to the intensive care unit in the first 24 h.