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Fialho AS, Cismondi F, Vieira SM, Sousa JMC, Reti SR, Howell MD, Finkelstein SN. Predicting Outcomes of Septic Shock Patients Using Feature Selection Based on Soft Computing Techniques. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/978-3-642-14058-7_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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Abstract
Mr A, a previously healthy 37-year-old man, was diagnosed as having Prinzmetal angina and a hypercoagulable state 3 years ago after an ST-elevation myocardial infarction. Now, his cardiologist is moving and Mr A must select a new physician and health system. Geographic relocation, insurance changes, and other events force millions in the United States to change physicians and hospitals every year. Mr A should begin by choosing a primary care physician, since continuity and coordination of care improves outcomes. Evidence for evaluating specific physicians is less robust, though a variety of sources are available. A broad range of detailed quality information, such as Medicare's Hospital Compare (http://www.hospitalcompare.hhs.gov/), is available for selecting a hospital. However, the relationship of these metrics to patient outcomes is variable, and different Web sites provide meaningfully different rankings and data interpretations. For Mr A in particular, a warfarin management team, the hospital's location, and a cardiologist with whom he feels comfortable and who can communicate with his primary care physician are important factors. Nevertheless, hospital quality information and metrics are an important component of the strategy Mr A should take to solve this challenging problem.
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Howell MD, Kim BE, Gao P, Grant AV, Boguniewicz M, DeBenedetto A, Schneider L, Beck LA, Barnes KC, Leung DYM. Cytokine modulation of atopic dermatitis filaggrin skin expression. J Allergy Clin Immunol 2009; 124:R7-R12. [PMID: 19720210 DOI: 10.1016/j.jaci.2009.07.012] [Citation(s) in RCA: 319] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/11/2007] [Accepted: 04/17/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD. OBJECTIVE We investigated whether reduced filaggrin expression was found in patients with AD who were not carriers of known filaggrin mutations and whether filaggrin expression was modulated by the atopic inflammatory response. METHODS Filaggrin expression was measured in skin biopsies and cultured keratinocytes using real-time RT-PCR and immunohistochemistry. Filaggrin loss-of-function mutations were screened in a total of 69 subjects. RESULTS Compared with normal skin, filaggrin expression was significantly reduced (P < .05) in acute AD skin, with further reduction seen in acute lesions from 3 European American subjects with AD who were heterozygous for the 2282del4 mutation. This was confirmed by using immunohistochemistry. AD skin is characterized by the overexpression of IL-4 and IL-13. Keratinocytes differentiated in the presence of IL-4 and IL-13 exhibited significantly reduced filaggrin gene expression (0.04 +/- 0.01 ng filaggrin/ng glyceraldehyde 3-phosphate dehydrogenase; P < .05) compared with media alone (0.16 +/- 0.03). CONCLUSION Patients with AD have an acquired defect in filaggrin expression that can be modulated by the atopic inflammatory response. CLINICAL IMPLICATIONS The atopic immune response contributes to the skin barrier defect in AD; therefore, neutralization of IL-4 and IL-13 could improve skin barrier integrity.
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Bin L, Howell MD, Kim BE, Hall CF, Streib JE, Leung DY. Inhibition of S100A11 gene expression impairs keratinocyte response against vaccinia virus through downregulation of the IL-10 receptor 2 chain. J Allergy Clin Immunol 2009; 124:270-7, 277.e1. [DOI: 10.1016/j.jaci.2009.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 04/30/2009] [Accepted: 05/05/2009] [Indexed: 01/23/2023]
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Herzig SJ, Howell MD, Ngo LH, Marcantonio ER. Acid-suppressive medication use and the risk for hospital-acquired pneumonia. JAMA 2009; 301:2120-8. [PMID: 19470989 DOI: 10.1001/jama.2009.722] [Citation(s) in RCA: 284] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CONTEXT The use of acid-suppressive medication has been steadily increasing, particularly in the inpatient setting, despite lack of an accepted indication in the majority of these patients. OBJECTIVE To examine the association between acid-suppressive medication and hospital-acquired pneumonia. DESIGN, SETTING, AND PATIENTS Prospective pharmacoepidemiologic cohort study. All patients who were admitted to a large, urban, academic medical center in Boston, Massachusetts, from January 2004 through December 2007; at least 18 years of age; and hospitalized for 3 or more days were eligible for inclusion. Admissions with time spent in the intensive care unit were excluded. Acid-suppressive medication use was defined as any order for a proton-pump inhibitor or histamine(2) receptor antagonist. Traditional and propensity-matched multivariable logistic regression were used to control for confounders. MAIN OUTCOME MEASURE Incidence of hospital-acquired pneumonia, defined via codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), in patients exposed and unexposed to acid-suppressive medication. RESULTS The final cohort comprised 63 878 admissions. Acid-suppressive medication was ordered in 52% of admissions and hospital-acquired pneumonia occurred in 2219 admissions (3.5%). The unadjusted incidence of hospital-acquired pneumonia was higher in the group exposed to acid-suppressive medication than in the unexposed group (4.9% vs 2.0%; odds ratio [OR], 2.6; 95% confidence interval [CI], 2.3-2.8). Using multivariable logistic regression, the adjusted OR of hospital-acquired pneumonia in the group exposed to acid-suppressive medication was 1.3 (95% CI, 1.1-1.4). The matched propensity-score analyses yielded identical results. The association was significant for proton-pump inhibitors (OR, 1.3; 95% CI, 1.1-1.4) but not for histamine(2) receptor antagonists (OR, 1.2; 95% CI, 0.98-1.4). CONCLUSIONS In this large, hospital-based pharmacoepidemiologic cohort, acid-suppressive medication use was associated with 30% increased odds of hospital-acquired pneumonia. In subset analyses, statistically significant risk was demonstrated only for proton-pump inhibitor use.
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Howell MD, Manetz TS, Meade BJ. COMPARISON OF MURINE ASSAYS FOR THE IDENTIFICATION OF CHEMICAL SENSITIZERS. ACTA ACUST UNITED AC 2008. [DOI: 10.1080/105172300242526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Howell MD, Fairchild HR, Kim BE, Bin L, Boguniewicz M, Redzic JS, Hansen KC, Leung DYM. Th2 cytokines act on S100/A11 to downregulate keratinocyte differentiation. J Invest Dermatol 2008; 128:2248-58. [PMID: 18385759 DOI: 10.1038/jid.2008.74] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Atopic dermatitis (AD) is an inflammatory skin disease associated with frequent skin infection and impaired skin barrier function. Recent studies indicate that increased Th2 cytokine expression contributes to reduction in antimicrobial peptides and reduced filaggrin (FLG) expression, however, the mechanisms leading to this effect is unknown. Using proteomics, we found the S100 calcium-binding protein A11 (S100/A11) to be significantly downregulated in the presence of IL-4 and IL-13. Culturing keratinocytes with increased calcium concentrations significantly induced S100/A11 expression. This corresponded with an increase in human beta-defensin (HBD)-3 and FLG expression. Interference of S100/A11 expression, by siRNA, inhibited induction of HBD-3 and FLG. Furthermore p21, a cyclin-dependent kinase inhibitor downstream of S100/A11, was required for calcium-mediated induction of HBD-3 and FLG. Importantly, transduction of p21-recombinant protein into keratinocytes prevented IL-4/IL-13-mediated inhibition of FLG and HBD-3 expression. S100/A11 and p21 gene expression was also found to be significantly lower in acute and chronic AD skin. This study demonstrates an important role for S100/A11 and p21 in regulating skin barrier integrity and the innate immune response.
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Abstract
PURPOSE OF REVIEW Atopic dermatitis is a chronic inflammatory skin disease associated with significant barrier disruption, T-helper type 2 mediated skin inflammation, and an impaired innate immune response. These characteristics increase the susceptibility of atopic dermatitis patients to recurrent skin infections, some of which may have potentially fatal implications. The mechanisms resulting in this increased propensity for skin infections have been an area of active investigation. RECENT FINDINGS Antimicrobial peptides are an integral component of the innate immune response due to their broad spectrum activity against invading pathogens. Recent studies have shown that these peptides are effective at killing Staphylococcus aureus, herpes simplex virus, vaccinia virus, and the Malassezia species, pathogens associated with significant morbidity in patients with atopic dermatitis. Additionally, these peptides are deficient in the skin of atopic dermatitis patients, suggesting that the increased propensity of patients towards skin infection is due to the lack of antimicrobial peptide expression. SUMMARY The current review will examine recent literature on the role of antimicrobial peptides in atopic dermatitis in an effort to improve our understanding of why patients with the condition suffer from recurrent infections.
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Kim BE, Leung DYM, Boguniewicz M, Howell MD. Loricrin and involucrin expression is down-regulated by Th2 cytokines through STAT-6. Clin Immunol 2007; 126:332-7. [PMID: 18166499 DOI: 10.1016/j.clim.2007.11.006] [Citation(s) in RCA: 370] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 11/12/2007] [Accepted: 11/14/2007] [Indexed: 12/16/2022]
Abstract
Atopic dermatitis (AD) is characterized by a defective skin barrier which allows increased allergen and pathogen penetration. Loricrin (LOR) and involucrin (IVL) are proteins important for skin barrier formation and integrity. In this study, we demonstrate that the gene and protein expression of LOR and IVL is significantly decreased in involved (LOR: p<0.001; IVL: p<0.001) and uninvolved (LOR: p<0.001; IVL: p<0.001) skin of AD subjects, as compared to skin from healthy subjects. Using primary keratinocytes, we further demonstrate the down-regulatory effect of IL-4 and IL-13--which are over-expressed in the skin of AD patients--on LOR and IVL expression in keratinocytes. Additionally, skin biopsies from signal transducer and activator of transcription (STAT)-6 transgenic mice were deficient in the expression and production of LOR and IVL. This study suggests that Th2 cytokines inhibit expression of LOR and IVL through a STAT-6 dependent mechanism.
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Scott JE, ElKhal A, Freyschmidt EJ, MacArthur DH, McDonald D, Howell MD, Leung DYM, Laouar A, Manjunath N, Bianchi T, Boes M, Oettgen HC, Geha RS. Impaired immune response to vaccinia virus inoculated at the site of cutaneous allergic inflammation. J Allergy Clin Immunol 2007; 120:1382-8. [PMID: 17889291 DOI: 10.1016/j.jaci.2007.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 07/30/2007] [Accepted: 08/01/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Patients with atopic dermatitis (AD) exposed to the vaccinia virus (VV) smallpox vaccine have an increased risk of developing eczema vaccinatum. OBJECTIVE To investigate the effects of local allergic skin inflammation on vaccinia immunity. METHODS BALB/c mice were epicutaneously sensitized with ovalbumin (OVA) to induce allergic skin inflammation or with saline control, then inoculated with an attenuated VV strain by skin scarification or intraperitoneally. After 8 days, serum IgG anti-VV and cytokine secretion by splenocytes were measured. RESULTS Mice inoculated with VV at sites of epicutaneous sensitization with OVA, but not control mice inoculated at saline exposed sites, developed satellite pox lesions and had impaired secretion of T(H)1 cytokines in response to VV, decreased VV specific serum IgG(2a), increased VV specific serum IgG(1), and impaired upregulation of IFN-alpha, but not the cathelicidin-related antimicrobial peptide, at the infection site. The VV immune response of OVA-sensitized mice inoculated with VV at distant skin sites or intraperitoneally was normal. CONCLUSION Local immune dysregulation at sites of allergic skin inflammation underlies the impaired T(H)1 immune response to VV introduced at these sites and the increased susceptibility to develop satellite pox lesions, a characteristic of eczema vaccinatum in patients with AD. CLINICAL IMPLICATIONS In a mouse model of AD, inoculation of VV at inflamed skin sites is associated with increased numbers of satellite pox lesions and an abnormal immune response to the virus. This may contribute to the susceptibility of patients with AD to virus dissemination after smallpox vaccination.
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Albanesi C, Fairchild HR, Madonna S, Scarponi C, De Pità O, Leung DYM, Howell MD. IL-4 and IL-13 negatively regulate TNF-alpha- and IFN-gamma-induced beta-defensin expression through STAT-6, suppressor of cytokine signaling (SOCS)-1, and SOCS-3. THE JOURNAL OF IMMUNOLOGY 2007; 179:984-92. [PMID: 17617590 DOI: 10.4049/jimmunol.179.2.984] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human beta-defensins (HBDs) are a major class of antimicrobial peptides that play an important role in the innate immune response, however, the induction and regulation of these antimicrobial peptides is not well understood. We demonstrate here that stimulation of keratinocytes with TNF-alpha/IFN-gamma induces HBD-2 and HBD-3 by activating STAT-1 and NF-kappaB signaling. We further demonstrate that IL-4 and IL-13 activate STAT-6 and induce the suppressors of cytokine signaling (SOCS)-1 and -3. This interferes with STAT-1 and NF-kappaB signaling, thereby inhibiting TNF-alpha/IFN-gamma-mediated induction of HBD-2 and HBD-3. These data suggest that targeting the STAT-1-signaling pathway or suppressor of cytokine signaling expression enhances beta-defensin expression and represents a new therapeutic strategy for reduction of infection in human diseases associated with beta-defensin deficiency.
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Donnino MW, Goyal N, Terlecki TM, Donnino KF, Miller JB, Otero RM, Howell MD. Inadequate blood volume collected for culture: a survey of health care professionals. Mayo Clin Proc 2007; 82:1069-72. [PMID: 17803874 DOI: 10.4065/82.9.1069] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Adequate blood culture volume is the single most important determinant for yield of organisms. We sought to determine whether health care professionals are aware of the current evidence-based recommendations for blood culture collection. An anonymous survey of employees qualified to collect blood cultures was conducted (July-October 2004) in an urban tertiary care facility. The survey asked,"What volume of blood should be collected in one bottle for a blood culture?" Of the 360 employees of the hospital surveyed, 355 returned evaluable answers for blood culture volume collected. Overall, 79% (95% confidence interval [CI], 74%-83%) answered less than 10 mL, and 44% (95% CI, 39%-49%) answered less than 5 mL of blood. When examined by occupation, 90% (95% CI, 86%-94%) of nurses, 97% (95% CI, 91%-100%) of technicians, and 55% (95% CI, 46%-64%) of physicians answered less than 10 mL; 52% (95% CI, 45%-59%) of nurses, 63% (95% CI, 46%-79%) of technicians, and 26% (95% CI, 18%-35%) of physicians answered less than 5 mL. Of all respondents, 21% (95% CI, 17%-25%) answered 1 mL or less. Our findings reveal that a high percentage of health care personnel do not know the optimal volume of blood recommended for collection. Because volume remains the most important determinant for the optimal yield of organisms, these findings raise an important quality assurance issue.
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Howell MD, Donnino MW, Talmor D, Clardy P, Ngo L, Shapiro NI. Performance of severity of illness scoring systems in emergency department patients with infection. Acad Emerg Med 2007; 14:709-14. [PMID: 17576773 DOI: 10.1197/j.aem.2007.02.036] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVES To validate the Mortality in Emergency Department Sepsis (MEDS) score, the Confusion, Urea nitrogen, Respiratory rate, Blood pressure, 65 years of age and older (CURB-65) score, and a modified Rapid Emergency Medicine Score (mREMS) in patients with suspected infection. METHODS This was a prospective cohort study. Adult patients with clinically suspected infection admitted from December 10, 2003, to September 30, 2004, in an urban emergency department with approximately 50,000 annual visits were eligible. The MEDS and CURB-65 scores were calculated as originally described, but REMS was modified in neurologic scoring because a full Glasgow Coma Scale score was not uniformly available. Discrimination of each score was assessed with the area under the receiver operating characteristics curve (AUC). RESULTS Of 2,132 patients, 3.9% (95% confidence interval [CI] = 3.1% to 4.7%) died. Mortality stratified by the MEDS score was as follows: 0-4 points, 0.4% (95% CI = 0.0 to 0.7%); 5-7 points, 3.3% (95% CI = 1.7% to 4.9%); 8-12 points, 6.6% (95% CI = 4.4% to 8.8%); and > or = 13 points, 31.6% (95% CI = 22.4% to 40.8%). Mortality stratified by CURB-65 was as follows: 0 points, 0% (0 of 457 patients); 1 point, 1.6% (95% CI = 0.6% to 2.6%); 2 points, 4.1% (95% CI = 2.3% to 6.0%); 3 points, 4.9% (95% CI = 2.8% to 6.9%); 4 points, 18.1% (95% CI = 11.9% to 24.3%); and 5 points, 28.0% (95% CI = 10.4% to 45.6%). Mortality stratified by the mREMS was as follows: 0-2 points, 0.6% (95% CI = 0 to 1.2%); 3-5 points, 2.0% (95% CI = 0.8% to 3.1%); 6-8 points, 2.3% (95% CI = 1.1% to 3.5%); 9-11 points, 7.1% (95% CI = 4.2% to 10.1%); 12-14 points, 20.0% (95% CI = 12.5% to 27.5%); and > or = 15 points, 40.0% (95% CI = 22.5% to 57.5%). The AUCs were 0.85, 0.80, and 0.79 for MEDS, mREMS, and CURB-65, respectively. CONCLUSIONS In this large cohort of patients with clinically suspected infection, MEDS, mREMS, and CURB-65 all correlated well with 28-day in-hospital mortality.
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Howell MD, Donnino M, Clardy P, Talmor D, Shapiro NI. Occult hypoperfusion and mortality in patients with suspected infection. Intensive Care Med 2007; 33:1892-9. [PMID: 17618418 DOI: 10.1007/s00134-007-0680-5] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Accepted: 03/30/2007] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To determine, in the early stages of suspected clinically significant infection, the independent relationship of the presenting venous lactate level to 28-day in-hospital mortality. DESIGN Prospective, observational cohort study. SETTING Urban, university tertiary-care hospital. PATIENTS One thousand two hundred and eighty seven adults admitted through the emergency department who had clinically suspected infection and a lactate measurement. MEASUREMENTS AND RESULTS Seventy-three [5.7% (95% CI 4.4-6.9%)] patients died in the hospital within 28 days. Lactate level was strongly associated with 28-day in-hospital mortality in univariate analysis (p<0.0001). When stratified by blood pressure, lactate remained associated with mortality (p<0.0001). Normotensive patients with a lactate level >or=4.0 mmol/l had a mortality rate of 15.0% (6.0-24%). Patients with either septic shock or lactate >or=4.0 mmol/l had a mortality rate of 28.3% (21.3-35.3%), which was significantly higher than those who had neither [mortality of 2.5% (1.6-3.4%), p<0.0001. In a model controlling for age, blood pressure, malignancy, platelet count, and blood urea nitrogen level, lactate remained strongly associated with mortality. Patients with a lactate level of 2.5-4.0 mmol/l had adjusted odds of death of 2.2 (1.1-4.2); those with lactate >or=4.0 mmol/l had 7.1 (3.6-13.9) times the odds of death. The model had good discrimination (AUC=0.87) and was well calibrated. CONCLUSIONS In patients admitted with clinically suspected infection, the venous lactate level predicts 28-day in-hospital mortality independent of blood pressure and adds significant prognostic information to that provided by other clinical predictors.
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Talmor D, Jones AE, Rubinson L, Howell MD, Shapiro NI. Simple triage scoring system predicting death and the need for critical care resources for use during epidemics. Crit Care Med 2007; 35:1251-6. [PMID: 17417099 DOI: 10.1097/01.ccm.0000262385.95721.cc] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES In the event of pandemic influenza, the number of critically ill victims will likely overwhelm critical care capacity. To date, no standardized method for allocating scarce resources when the number of patients in need far exceeds capacity exists. We sought to derive and validate such a triage scheme. DESIGN : Retrospective analysis of prospectively collected data. SETTING Emergency departments of two urban tertiary care hospitals. PATIENTS Three separate cohorts of emergency department patients with suspected infection, comprising a total of 5,133 patients. INTERVENTIONS None. MEASUREMENTS A triage decision rule for use in an epidemic was developed using only those vital signs and patient characteristics that were readily available at initial presentation to the emergency department. The triage schema was derived from a cohort at center 1, validated on a second cohort from center 1, and then validated on a third cohort of patients from center 2. The primary outcome for the analysis was in-hospital mortality. Secondary outcomes were intensive care unit admission and use of mechanical ventilation. MAIN RESULTS Multiple logistic regression demonstrated the following as independent predictors of death: a) age of >65 yrs, b) altered mental status, c) respiratory rate of >30 breaths/min, d) low oxygen saturation, and e) shock index of >1 (heart rate > blood pressure). This model had an area under the receiver operating characteristic curve of 0.80 in the derivation set and 0.74 and 0.76 in the validation sets. When converted to a simple rule assigning 1 point per covariate, the discrimination of the model remained essentially unchanged. The model was equally effective at predicting need for intensive care unit admission and mechanical ventilation. CONCLUSIONS If, as expected, patient demand far exceeds the capability to provide critical care services in an epidemic, a fair and just system to allocate limited resources will be essential. The triage rule we have developed can serve as an initial guide for such a process.
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Howell MD, Kim BE, Gao P, Grant AV, Boguniewicz M, Debenedetto A, Schneider L, Beck LA, Barnes KC, Leung DYM. Cytokine modulation of atopic dermatitis filaggrin skin expression. J Allergy Clin Immunol 2007; 120:150-5. [PMID: 17512043 PMCID: PMC2669594 DOI: 10.1016/j.jaci.2007.04.031] [Citation(s) in RCA: 534] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/11/2007] [Accepted: 04/17/2007] [Indexed: 11/29/2022]
Abstract
BACKGROUND Atopic dermatitis (AD) is a chronic inflammatory skin disease that is characterized by a defective skin barrier function. Recent studies have reported mutations of the skin barrier gene encoding filaggrin in a subset of patients with AD. OBJECTIVE We investigated whether reduced filaggrin expression was found in patients with AD who were not carriers of known filaggrin mutations and whether filaggrin expression was modulated by the atopic inflammatory response. METHODS Filaggrin expression was measured in skin biopsies and cultured keratinocytes using real-time RT-PCR and immunohistochemistry. Filaggrin loss-of-function mutations were screened in a total of 69 subjects. RESULTS Compared with normal skin, filaggrin expression was significantly reduced (P < .05) in acute AD skin, with further reduction seen in acute lesions from 3 European American subjects with AD who were heterozygous for the 2282del4 mutation. This was confirmed by using immunohistochemistry. AD skin is characterized by the overexpression of IL-4 and IL-13. Keratinocytes differentiated in the presence of IL-4 and IL-13 exhibited significantly reduced filaggrin gene expression (0.04 +/- 0.01 ng filaggrin/ng glyceraldehyde 3-phosphate dehydrogenase; P < .05) compared with media alone (0.16 +/- 0.03). CONCLUSION Patients with AD have an acquired defect in filaggrin expression that can be modulated by the atopic inflammatory response. CLINICAL IMPLICATIONS The atopic immune response contributes to the skin barrier defect in AD; therefore, neutralization of IL-4 and IL-13 could improve skin barrier integrity.
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Kisich KO, Howell MD, Boguniewicz M, Heizer HR, Watson NU, Leung DYM. The constitutive capacity of human keratinocytes to kill Staphylococcus aureus is dependent on beta-defensin 3. J Invest Dermatol 2007; 127:2368-80. [PMID: 17460726 DOI: 10.1038/sj.jid.5700861] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Normal skin is often exposed to bacteria, including potent pathogens such as E. coli, Staphylococcus aureus, and Streptococcus sp., but these microbes usually do not cause skin inflammation or infection in healthy individuals. Therefore, we hypothesized that there must be a constitutive mechanism for rapid destruction and elimination of small numbers of bacteria which penetrate the stratum corneum from everyday activities. This study found that exposure of keratinocytes cultured from a number of individuals to S. aureus resulted in approximately 2-3 log better killing than by HaCaT cells within 1 hour. Killing required contact between the keratinocytes and the bacteria, but was not dependent on internalization. Contact between the bacteria and the keratinocytes resulted in rapid deposition of several antimicrobial peptides onto the bacteria, but only human beta-defensin (HBD) 3 accumulated at levels sufficient to account for killing when S. aureus were exposed to human skin explants. Blocking peptide binding of HBD3 inhibited killing of the bacteria, indicating an essential role for beta-defensin 3 in the constitutive killing of bacteria by normal keratinocytes.
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Howell MD, Streib JE, Leung DYM. Antiviral activity of human beta-defensin 3 against vaccinia virus. J Allergy Clin Immunol 2007; 119:1022-5. [PMID: 17353034 PMCID: PMC2668144 DOI: 10.1016/j.jaci.2007.01.044] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 01/26/2007] [Accepted: 01/29/2007] [Indexed: 10/23/2022]
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Shapiro NI, Howell MD, Talmor D, Donnino M, Ngo L, Bates DW. Mortality in Emergency Department Sepsis (MEDS) score predicts 1-year mortality. Crit Care Med 2007; 35:192-8. [PMID: 17110874 DOI: 10.1097/01.ccm.0000251508.12555.3e] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To assess the predictive performance for 1-yr mortality of the previously derived and validated Mortality in Emergency Department Sepsis (MEDS) score. DESIGN Prospective cohort study. PATIENTS Consecutive adult (aged > or =18 yrs) emergency department patients presenting to an urban, tertiary care, university hospital were eligible if they had a clinically suspected infection as indicated by the decision to obtain a blood culture. The enrollment period was between February 1, 2000, and February 1, 2001. Of 3,926 eligible patient visits, 3,762 (96%) were enrolled and 3,102 unique first visits were analyzed. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A total of 667 patients (21.5%) died within 1 yr. The unadjusted 1-yr mortality rates for the MEDS risk groups were: very low risk, 7%; low risk, 20%; moderate risk, 37%; high risk, 64%; very high risk, 80%. Using a Cox proportional hazard model that controlled for age, sex, and Charlson co-morbidity index, the 1-yr hazard ratios compared with the baseline very low-risk group were: low risk, 2.2 (1.7-2.9); moderate risk, 3.5 (2.7-4.6); high risk, 6.7 (4.9-9.3); and very high risk, 10.5 (7.2-15.4). The groups were significantly different (p < .0001). CONCLUSIONS Although the score was initially derived for 28-day in-hospital mortality, our results indicate that the MEDS score also predicts patient survival at 1 yr after index hospital visit with suspected infection. The score needs external validation before widespread use.
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Kim BE, Leung DY, Streib JE, Boguniewicz M, Hamid QA, Howell MD. Macrophage inflammatory protein 3alpha deficiency in atopic dermatitis skin and role in innate immune response to vaccinia virus. J Allergy Clin Immunol 2006; 119:457-63. [PMID: 17141855 PMCID: PMC2746067 DOI: 10.1016/j.jaci.2006.10.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 10/04/2006] [Accepted: 10/09/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Patients with atopic dermatitis (AD) are prone to disseminated viral skin infections and therefore are not vaccinated against smallpox because of potential complications. Macrophage inflammatory protein 3alpha (MIP-3alpha) is a C-C chemokine expressed by keratinocytes that exhibits antimicrobial activity against bacteria and fungi; however, its role in antiviral innate immunity is unknown. OBJECTIVE Evaluate the level of MIP-3alpha in AD skin and its role in the innate immune response to vaccinia virus (VV). METHODS Macrophage inflammatory protein 3alpha levels were evaluated using real-time RT-PCR, immunodot-blot, and immunohistochemistry. The antiviral activity of MIP-3alpha was determined using a standard viral plaque assay. RESULTS Macrophage inflammatory protein 3alpha gene expression was significantly (P < .01) decreased in AD skin (0.21 +/- 0.05 ng MIP-3alpha/ng glyceraldehyde-3-phosphate dehydrogenase) compared with psoriasis skin (0.67 +/- 0.13). This was confirmed at the protein level using immunohistochemistry. We further demonstrate that T(H)2 cytokines downregulate MIP-3alpha expression. The importance of MIP-3alpha in the innate immune response against VV was established by first demonstrating that MIP-3alpha exhibits activity against VV. Second, VV replication was significantly increased (P < .01) in keratinocytes treated with an antibody to neutralize MIP-3alpha. CONCLUSION The current study demonstrates that MIP-3alpha exhibits antiviral activity against VV and demonstrates the importance of MIP-3alpha in the innate immune response against VV. In addition, AD skin is deficient in MIP-3alpha, in part because of the overexpression of T(H)2 cytokines in AD skin. CLINICAL IMPLICATIONS MIP-3alpha deficiency in AD skin contributes to patients' increased propensity toward eczema vaccinatum. Increasing MIP-3alpha or neutralizing T(H)2 cytokines could prevent adverse reactions in patients with AD after smallpox vaccination.
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Shapiro N, Howell MD, Bates DW, Angus DC, Ngo L, Talmor D. The association of sepsis syndrome and organ dysfunction with mortality in emergency department patients with suspected infection. Ann Emerg Med 2006; 48:583-90, 590.e1. [PMID: 17052559 DOI: 10.1016/j.annemergmed.2006.07.007] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 05/31/2006] [Accepted: 06/13/2006] [Indexed: 11/20/2022]
Abstract
STUDY OBJECTIVE The critical care community has used standard criteria for defining the sepsis syndromes and organ dysfunction for more than 15 years; however, these criteria are not well validated in the emergency department (ED) setting. The study objectives in our ED population of patients admitted to the hospital are to determine the prevalence of the sepsis syndromes, quantify inhospital mortality and 1-year survival associated with the sepsis syndromes, and assess the inhospital and 1-year survival associated with organ dysfunctions. METHODS This was a prospective, observational, cohort study from February 1, 2000, to February 1, 2001 in an urban university hospital ED with 50,000 annual visits. There were 3,102 (96% of eligible) consecutive adult patients (aged 18 years or older) with suspected infection (as indicated by the clinical decision to obtain a blood culture) who were enrolled. Patients were screened for systemic inflammatory response syndrome (SIRS) (2 or more indicators of inflammatory response), sepsis (SIRS plus suspected infection), severe sepsis (sepsis plus organ dysfunction), septic shock (sepsis plus hypotension refractory to an initial fluid challenge), and number of organs with acute dysfunction. Main outcome measure was inhospital and 1-year mortality. RESULTS Overall inhospital mortality was 4.1% and 1-year mortality was 22%. The inhospital mortality rates were suspected infection without SIRS 2.1%, sepsis 1.3%, severe sepsis 9.2%, and septic shock 28%. Compared to suspected infection without SIRS, adjusted risks of inhospital mortality were severe sepsis (odds ratio [OR] 4.0; 95% confidence interval [CI] 2.6 to 6.3) and septic shock (OR 13.8; 95% CI 6.6 to 29). Severe sepsis (OR 2.2; 95% CI 1.8 to 2.6) and septic shock (OR 3.5; 95% CI 2.3 to 5.3) also predicted 1-year mortality. The presence of SIRS criteria alone had no prognostic value for either endpoint. Each additional organ dysfunction increased the adjusted 1-year mortality hazard by 82% (pulse rate: 1.82, 95% CI 1.7 to 2.0). CONCLUSION Immediate identification of acute organ dysfunction in ED patients with suspected infection may help select patients at increased short- and long-term mortality risk. SIRS criteria offered no additional prognostic value, whereas each additional organ dysfunction increased the 1-year mortality risk.
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Howell MD, Boguniewicz M, Pastore S, Novak N, Bieber T, Girolomoni G, Leung DYM. Mechanism of HBD-3 deficiency in atopic dermatitis. Clin Immunol 2006; 121:332-8. [PMID: 17015038 DOI: 10.1016/j.clim.2006.08.008] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 08/08/2006] [Accepted: 08/11/2006] [Indexed: 01/27/2023]
Abstract
Extrinsic atopic dermatitis (EAD) and intrinsic atopic dermatitis (IAD) patients suffer from recurrent bacterial and viral infections. In this study, we demonstrate significantly decreased expression of human beta defensin (HBD)-3, a potent antimicrobial peptide (AMP), in lesional skin of both IAD (p<0.01) and EAD patients (p<0.01), as compared to psoriasis patients. Using primary keratinocytes from EAD and IAD patients, we determined that the deficiency in HBD-3 expression is an acquired rather than a constitutive defect. Furthermore, we demonstrate the down-regulatory effect of IL-4, IL-10, and IL-13 - which are over-expressed in the skin of AD patients - on HBD-3 expression in keratinocytes. Additionally, treatment of EAD skin explants with antibodies against IL-4, IL-10, and IL-13 augmented the expression of HBD-3. These studies suggest that neutralizing the Th2 cytokine milieu in AD skin may augment the innate immune response against bacterial and viral pathogens.
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Howell MD, Gallo RL, Boguniewicz M, Jones JF, Wong C, Streib JE, Leung DYM. Cytokine milieu of atopic dermatitis skin subverts the innate immune response to vaccinia virus. Immunity 2006; 24:341-8. [PMID: 16546102 DOI: 10.1016/j.immuni.2006.02.006] [Citation(s) in RCA: 255] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Revised: 01/03/2006] [Accepted: 02/01/2006] [Indexed: 02/07/2023]
Abstract
Atopic dermatitis (AD) is associated with eczema vaccinatum (EV), a disseminated viral skin infection that follows inoculation with vaccinia virus (VV). This study examined whether AD skin can control VV replication, and the role of IL-4 and IL-13 in modulating the human cathelicidin LL-37, an antimicrobial peptide that kills VV. AD skin exhibited increased VV replication and decreased LL-37 expression compared to normal or psoriasis skin. IL-4/IL-13 enhanced VV replication while downregulating LL-37 in VV-stimulated keratinocytes. Neutralizing IL-4/IL-13 in AD skin augmented LL-37 and inhibited VV replication. Cathelicidins were induced via toll-like receptor-3 and were inhibited by IL-4/IL-13 through STAT-6. Skin from cathelicidin-deficient mice exhibited reduced ability to control VV replication. Exogenous LL-37 controlled vaccinia viral replication in infected keratinocytes and AD skin explants. The current study demonstrates that Th2 cytokines enhance VV replication in AD skin by subverting the innate immune response against VV in a STAT-6-dependent manner.
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Shapiro NI, Howell MD, Talmor D, Lahey D, Ngo L, Buras J, Wolfe RE, Weiss JW, Lisbon A. Implementation and outcomes of the Multiple Urgent Sepsis Therapies (MUST) protocol*. Crit Care Med 2006; 34:1025-32. [PMID: 16484890 DOI: 10.1097/01.ccm.0000206104.18647.a8] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To describe the effectiveness of a comprehensive, interdisciplinary sepsis treatment protocol with regard to both implementation and outcomes and to compare the mortality rates and therapies of patients with septic shock with similar historical controls. DESIGN Prospective, interventional cohort study with a historical control comparison group. SETTING Urban, tertiary care, university hospital with 46,000 emergency department visits and 4,100 intensive care unit admissions annually. PATIENTS Inclusion criteria were a) emergency department patients aged > or =18 yrs, b) suspected infection, and c) lactate of >4 mmol/L or septic shock. Exclusion criteria were a) emergent operation, b) prehospital cardiac arrest, and c) comfort measures only. Time period: protocol, November 10, 2003, through November 9, 2004; historical controls, February 1, 2000, through January 31, 2001. INTERVENTION A sepsis treatment pathway incorporating empirical antibiotics, early goal-directed therapy, drotrecogin alfa, steroids, intensive insulin therapy, and lung-protective ventilation. MEASUREMENTS AND MAIN RESULTS There were 116 protocol patients, with a mortality rate of 18% (11-25%), of which 79 patients had septic shock. Comparing these patients with 51 historical controls, protocol patients received more fluid (4.0 vs. 2.5 L crystalloid, p < .001), earlier antibiotics (90 vs. 120 mins, p < .013), more appropriate empirical coverage (97% vs. 88%, p < .05), more vasopressors in the first 6 hrs (80% vs. 45%, p < .001), tighter glucose control (mean morning glucose, 123 vs. 140, p < .001), and more frequent assessment of adrenal function (82% vs. 10%, p < .001), with a nonstatistically significant increase in dobutamine use (14% vs. 4%, p = .06) and red blood cell transfusions (30% vs. 18%, p = .07) in the first 24 hrs. For protocol patients with septic shock, 28-day in-hospital mortality was 20.3% compared with 29.4% for historical controls (p = .3). CONCLUSIONS Clinical implementation of a comprehensive sepsis treatment protocol is feasible and is associated with changes in therapies such as time to antibiotics, intravenous fluid delivery, and vasopressor use in the first 6 hrs. No statistically significant decrease in mortality was demonstrated, as this trial was not sufficiently powered to assess mortality benefits.
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