MicroRNA-155 regulates host immune response to postviral bacterial pneumonia via IL-23/IL-17 pathway.

Postinfluenza bacterial pneumonia is associated with significant mortality and morbidity. MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression posttranscriptionally. miR-155 has recently emerged as a crucial regulator of innate immunity and inflammatory responses and is induced in macrophages during infection. We hypothesized upregulation of miR-155 inhibits IL-17 and increases susceptibility to secondary bacterial pneumonia. Mice were challenged with 100 plaque-forming units H1N1 intranasally and were infected with 10(7) colony-forming units of MRSA intratracheally at day 5 postviral challenge. Lungs were harvested 24 h later, and expression of miR-155, IL-17, and IL-23 was measured by real-time RT-PCR. Induction of miR-155 was 3.6-fold higher in dual-infected lungs compared with single infection. miR-155(-/-) mice were protected with significantly lower (4-fold) bacterial burden and no differences in viral load, associated with robust induction of IL-23 and IL-17 (2.2- and 4.8-fold, respectively) postsequential challenge with virus and bacteria, compared with WT mice. Treatment with miR-155 antagomir improved lung bacterial clearance by 4.2-fold compared with control antagomir postsequential infection with virus and bacteria. Moreover, lung macrophages collected from patients with postviral bacterial pneumonia also had upregulation of miR-155 expression compared with healthy controls, consistent with observations in our murine model. This is the first demonstration that cellular miRNAs regulate postinfluenza immune response to subsequent bacterial challenge by suppressing the IL-17 pathway in the lung. Our findings suggest that antagonizing certain microRNA might serve as a potential therapeutic strategy against secondary bacterial infection.

Cardiogenic Auto-Triggering as a Consequence of Hemoperitoneum.

A 70-year-old woman presented with hemorrhagic shock secondary to hemoperitoneum following a paracentesis. On hospital day 3, she developed respiratory alkalosis and increased respiratory rates observed on the ventilator despite no spontaneous inspiratory effort. Converting to pressure support mode uncovered a cardiogenic oscillatory flow that had been auto-triggering the ventilator. This cardiogenic auto-triggering resolved with large-volume paracentesis. Cardiogenic auto-triggering leads to patient-ventilator dyssynchrony, respiratory alkalosis, lung distension, and difficulty with weaning from the ventilator, and it may be unrecognized in ICUs.

Endotracheal tubes: old and new.

The development and evolution of the endotracheal tube (ETT) have been closely related to advances in surgery and anesthesia. Modifications were made to accomplish many tasks, including minimizing gross aspiration, isolating a lung, providing a clear facial surgical field during general anesthesia, monitoring laryngeal nerve damage during surgery, preventing airway fires during laser surgery, and administering medications. In critical care management, ventilator-associated pneumonia (VAP) is a major concern, as it is associated with increased morbidity, mortality, and cost. It is increasingly appreciated that the ETT itself is a primary causative risk for developing VAP. Unfortunately, contaminated oral and gastric secretions leak down past the inflated ETT cuff into the lung. Bacteria can also grow within the ETT in biofilm and re-enter the lung. Modifications to the ETT that attempt to prevent bacteria from entering around the ETT include maintaining an adequate cuff pressure against the tracheal wall, changing the material and shape of the cuff, and aspirating the secretions that sit above the cuff. Attempts to reduce bacterial entry through the tube include antimicrobial coating of the ETT and mechanically scraping the biofilm from within the ETT. Studies evaluating the effectiveness of these modifications and techniques demonstrate mixed results, and clear recommendations for which modification should be implemented are weak.

Maximum voluntary isometric pinch contraction and force-matching from the fourth to the eighth decades of life.

Understanding the effects of age and gender on pinch strength, variability, and accuracy and how one's hand function changes with age better enables those in the preventative and rehabilitative fields to combat these losses. The present study examined fine motor maximum pinch strength [maximum voluntary isometric contraction (MVIC)] as well as the ability to maintain 5% MVIC accurately and consistently in five decades. One hundred adults in five groups, 20 in each decade of life from 30 to 79 years old, were nonrandomly recruited from the community. A two-way analysis of variance applied to MVIC, and a two-way multivariate analysis of variance applied to the variability (coefficient of variability) and accuracy (root mean square error), plus correlation and regression analyses, were used to determine decade and gender effects on pinch force. The task involved using isometric pinch control of a computer cursor to match a 5% of MVIC force level represented by a horizontal line. MVIC and force-matching steadiness and accuracy across all ages were not significantly different until the eighth decade (P<0.01). Men were stronger (P<0.001) but performed low-level force-matching with greater error (P<0.001) than women. Strength was not correlated with steadiness but was weakly correlated with accuracy (r=0.293, P<0.01), and steadiness and accuracy were strongly correlated (r=0.783, P<0.001). Decade and gender were moderate and strong predictors of accuracy and steadiness, respectively. In conclusion, age and gender differences were evident in pinch-force strength and control.

Pogonophryne neyelovi , a new species of Antarctic short-barbeled plunderfish (Perciformes, Notothenioidei, Artedidraconidae) from the deep Ross Sea.

This paper continues descriptions of new deep-water Antarctic barbeled plunderfishes of the poorly known and the most speciose notothenioid genus Pogonophryne. It is based on a comprehensive collection obtained by the authors in 2009-2010 during an Antarctic toothfish (Dissostichus mawsoni) fishing trip. A new species, the hopbeard plunderfish Pogonophryne neyelovi, the twenty-second species of the genus, is described. The new species belongs to dorsally-spotted short-barbeled species forming the "Pogonophryne mentella" group. Pogonophryne neyelovi sp. n. is characterized by the following combination of characters: a very short and small mental barbel with an ovaloid and short terminal expansion covered by flattened scale-like processes that are mostly bluntly palmate; a moderately protruding lower jaw; a high second dorsal fin almost uniformly black and lacking a sharply elevated anterior lobe; pectoral fins striped anteriorly and uniformly light posteriorly; the anal and pelvic fins light; the dorsal surface of the head and the area anterior to the first dorsal fin covered with large, irregular dark brown blotches and spots; the ventral surface of the head, breast and belly without sharp dark markings. The new species is compared to the closest species Pogonophryne brevibarbata, Pogonophryne tronio, and Pogonophryne ventrimaculata. English vernacular names are proposed for all species of the genus.