The pulmonary endothelial glycocalyx regulates neutrophil adhesion and lung injury during experimental sepsis.

Sepsis, a systemic inflammatory response to infection, commonly progresses to acute lung injury (ALI), an inflammatory lung disease with high morbidity. We postulated that sepsis-associated ALI is initiated by degradation of the pulmonary endothelial glycocalyx, leading to neutrophil adherence and inflammation. Using intravital microscopy, we found that endotoxemia in mice rapidly induced pulmonary microvascular glycocalyx degradation via tumor necrosis factor-α (TNF-α)-dependent mechanisms. Glycocalyx degradation involved the specific loss of heparan sulfate and coincided with activation of endothelial heparanase, a TNF-α-responsive, heparan sulfate-specific glucuronidase. Glycocalyx degradation increased the availability of endothelial surface adhesion molecules to circulating microspheres and contributed to neutrophil adhesion. Heparanase inhibition prevented endotoxemia-associated glycocalyx loss and neutrophil adhesion and, accordingly, attenuated sepsis-induced ALI and mortality in mice. These findings are potentially relevant to human disease, as sepsis-associated respiratory failure in humans was associated with higher plasma heparan sulfate degradation activity; moreover, heparanase content was higher in human lung biopsies showing diffuse alveolar damage than in normal human lung tissue.

The response to methylene blue in patients with severe hypotension during liver transplantation.

Methylene blue is a useful therapy for catecholamine-resistant vasoplegic shock. Three cases of methylene blue administration for the treatment of catecholamine-resistant hypotension during orthotopic liver transplantation are presented.

Standard subcutaneous dosing of unfractionated heparin for venous thromboembolism prophylaxis in surgical ICU patients leads to subtherapeutic factor Xa inhibition.

PURPOSE: To assess coagulation status and factor Xa inhibition in surgical intensive care unit (ICU) patients administered prophylactic unfractionated heparin for venous thromboembolism (VTE) prophylaxis. METHODS: We conducted a randomized, single-blind study at a tertiary academic medical center. Included were patients 18 years and older admitted to the surgical ICU directly after major abdominal surgery. Exclusion criteria included significant bleeding risk, preoperative anticoagulation, or history of heparin-induced thrombocytopenia. Patients were randomized to two regimens for VTE prophylaxis: standard of care unfractionated heparin, 5,000 units subcutaneously three times daily (SQH) versus unfractionated heparin via intravenous infusion, titrated to an activated partial thromboplastin time of 40-45 s (IVH). Blood samples were taken prior to surgical incision on day 0 and daily for 5 days after surgery. Samples were analyzed for factor Xa inhibition and viscoelastic whole blood clotting parameters (Sonoclot analyzer). RESULTS: A total of 50 patients were randomized to either SQH or IVH. The majority of patients had cancer. Patients in the SQH group had no detectable peak anti-factor Xa (aFXa) activity for 5 days after surgery, while patients in the IVH group had statistically elevated levels compared to the SQH group on days 3-5. SQH patients demonstrated a hypercoagulable profile on Sonoclot, while IVH patients displayed a normal profile. CONCLUSIONS: Standard of care subcutaneous dosing of unfractionated heparin for VTE prophylaxis in surgical ICU patients leads to subtherapeutic levels of factor Xa inhibition.

Variables associated with feeding tube placement in head and neck cancer.

OBJECTIVE: To identify clinical factors associated with enteral feeding tube placement in a head and neck cancer population. DESIGN: A self-administered survey was given to patients being treated for head and neck cancer while they were waiting to be seen in 1 of 4 otolaryngology clinics. The post hoc analysis presented here combines survey and chart review data to determine clinical and demographic variables associated with feeding tube placement. SETTING: Four otolaryngology clinics. PATIENTS: Otolaryngology clinic patients being treated for head and neck cancer. MAIN OUTCOME MEASURE: Enteral feeding tube placement. RESULTS: Of the 724 patients eligible for this study, 14% (n = 98) required enteral feeding tube placement. Multivariate analysis found the following variables to be independently associated with feeding tube placement: oropharynx/hypopharynx tumor site (odds ratio [OR], 2.4; P = .01), tumor stage III/IV (OR, 2.1; P = .03), flap reconstruction (OR, 2.2; P = .004), current tracheotomy (OR, 8.0; P<.001), chemotherapy (OR, 2.6; P<.001), and increased age (OR, 1.3; P = .02). In addition, there was a curvilinear relationship between time since treatment and feeding tube placement, with about 30% having a feeding tube at 1 month posttreatment, tapering down during the first 3 years to about 8% and leveling off thereafter. CONCLUSIONS: Identification of factors associated with an increased risk of feeding tube placement may allow physicians to better counsel patients regarding the possibility of feeding tube placement during treatment. Since feeding tube placement has been linked to decreased quality of life in head and neck cancer, such counseling is an integral part of the clinical management of these patients.

Laryngeal paraganglioma in a patient with multiple head and neck paragangliomas.

Paragangliomas of the larynx are rare neuroendocrine tumors, with fewer than 70 cases reported in the literature. 1 Typically, laryngeal paragangliomas are not found in patients with multicentric or familial paragangliomas. Only 1 case of laryngeal paraganglioma has been reported in a patient with a synchronous lesion elsewhere (carotid body tumor). 2 We report an additional case of a patient with a laryngeal and multiple other paragangliomas.

Eotaxin/CCL11 is a negative regulator of neutrophil recruitment in a murine model of endotoxemia.

Eotaxin/CCL11 is a chemokine that has been primarily characterized with respect to its eosinophil chemoattractant activity. However, the broad tissue expression of eotaxin/CCL11 suggests that it may have other unknown activities. We have used a murine model of endotoxemia to study the role of eotaxin/CCL11 in neutrophil recruitment. We demonstrate that eotaxin/CCL11 is acutely upregulated in the serum, peritoneal wash, and lungs of mice given an intraperitoneal lipopolysaccharide (LPS) challenge. Furthermore, immunoneutralization of eotaxin/CCL11 in this model results in a significant increase in the number of neutrophils within the lung after LPS challenge. When eotaxin/CCL11 knockout mice were challenged with LPS, these mice had increased peritoneal neutrophils, but not lung neutrophils, compared to the wild-type controls. Administration of eotaxin/CCL11 to eotaxin(-/-) mice suppressed endotoxemia-associated peritoneal neutrophils. The presence or absence of eotaxin/CCL11 did not affect the number of peritoneal macrophages in these mice. These data indicate that eotaxin/CCL11 plays a novel regulatory role during the acute inflammatory response and suggest that constitutive expression of this chemokine within tissues such as the gut, lung, heart, and placenta might be important in downregulating acute inflammatory processes within these tissues.

Eotaxin/CCL11 suppresses IL-8/CXCL8 secretion from human dermal microvascular endothelial cells.

The CC chemokine eotaxin/CCL11 is known to bind to the receptor CCR3 on eosinophils and Th2-type lymphocytes. In this study, we demonstrate that CCR3 is expressed on a subpopulation of primary human dermal microvascular endothelial cells and is up-regulated by TNF-alpha. We found that incubation of human dermal microvascular endothelial cells with recombinant eotaxin/CCL11 suppresses TNF-alpha-induced production of the neutrophil-specific chemokine IL-8/CXCL8. The eotaxin/CCL11-suppressive effect on endothelial cells was not seen on IL-1beta-induced IL-8/CXCL8 release. Eotaxin/CCL11 showed no effect on TNF-alpha-induced up-regulation of growth-related oncogene-alpha or IFN-gamma-inducible protein-10, two other CXC chemokines tested, and did not affect production of the CC chemokines monocyte chemoattractant protein-1/CCL2 and RANTES/CCL5, or the adhesion molecules ICAM-1 and E-selectin. These results suggest that eotaxin/CXCL11 is not effecting a general suppression of TNF-alphaR levels or signal transduction. Suppression of IL-8/CXCL8 was abrogated in the presence of anti-CCR3 mAb, pertussis toxin, and wortmannin, indicating it was mediated by the CCR3 receptor, G(i) proteins, and phosphatidylinositol 3-kinase signaling. Eotaxin/CCL11 decreased steady state levels of IL-8/CXCL8 mRNA in TNF-alpha-stimulated cells, an effect mediated in part by an acceleration of IL-8 mRNA decay. Eotaxin/CCL11 may down-regulate production of the neutrophil chemoattractant IL-8/CXCL8 by endothelial cells in vivo, acting as a negative regulator of neutrophil recruitment. This may play an important biological role in the prevention of overzealous inflammatory responses, aiding in the resolution of acute inflammation or transition from neutrophilic to mononuclear/eosinophilic inflammation.