Cellulitis: A Review Raff, Adam B; Kroshinsky, Daniela
JAMA : the journal of the American Medical Association,
2016-Jul-19, Letnik:
316, Številka:
3
Journal Article
Recenzirano
Cellulitis is an infection of the deep dermis and subcutaneous tissue, presenting with expanding erythema, warmth, tenderness, and swelling. Cellulitis is a common global health burden, with more ...than 650,000 admissions per year in the United States alone.
In the United States, an estimated 14.5 million cases annually of cellulitis account for $3.7 billion in ambulatory care costs alone. The majority of cases of cellulitis are nonculturable and therefore the causative bacteria are unknown. In the 15% of cellulitis cases in which organisms are identified, most are due to β-hemolytic Streptococcus and Staphylococcus aureus. There are no effective diagnostic modalities, and many clinical conditions appear similar. Treatment of primary and recurrent cellulitis should initially cover Streptococcus and methicillin-sensitive S. aureus, with expansion for methicillin-resistant S. aureus (MRSA) in cases of cellulitis associated with specific risk factors, such as athletes, children, men who have sex with men, prisoners, military recruits, residents of long-term care facilities, those with prior MRSA exposure, and intravenous drug users. Five days of treatment is sufficient with extension if symptoms are not improved. Addressing predisposing factors can minimize risk of recurrence.
The diagnosis of cellulitis is based primarily on history and physical examination. Treatment of uncomplicated cellulitis should be directed against Streptococcus and methicillin-sensitive S. aureus. Failure to improve with appropriate first-line antibiotics should prompt consideration for resistant organisms, secondary conditions that mimic cellulitis, or underlying complicating conditions such as immunosuppression, chronic liver disease, or chronic kidney disease.
Mucosotropic, high-risk human papillomaviruses (HPV) are sexually transmitted viruses that are causally associated with the development of cervical cancer. The most common high-risk genotype, HPV16, ...is an obligatory intracellular virus that must gain entry into host epithelial cells and deliver its double stranded DNA to the nucleus. HPV capsid proteins play a vital role in these steps. Despite the critical nature of these capsid protein-host cell interactions, the precise cellular components necessary for HPV16 infection of epithelial cells remains unknown. Several neutralizing epitopes have been identified for the HPV16 L2 minor capsid protein that can inhibit infection after initial attachment of the virus to the cell surface, which suggests an L2-specific secondary receptor or cofactor is required for infection, but so far no specific L2-receptor has been identified. Here, we demonstrate that the annexin A2 heterotetramer (A2t) contributes to HPV16 infection and co-immunoprecipitates with HPV16 particles on the surface of epithelial cells in an L2-dependent manner. Inhibiting A2t with an endogenous annexin A2 ligand, secretory leukocyte protease inhibitor (SLPI), or with an annexin A2 antibody significantly reduces HPV16 infection. With electron paramagnetic resonance, we demonstrate that a previously identified neutralizing epitope of L2 (aa 108-120) specifically interacts with the S100A10 subunit of A2t. Additionally, mutation of this L2 region significantly reduces binding to A2t and HPV16 pseudovirus infection. Furthermore, downregulation of A2t with shRNA significantly decreases capsid internalization and infection by HPV16. Taken together, these findings indicate that A2t contributes to HPV16 internalization and infection of epithelial cells and this interaction is dependent on the presence of the L2 minor capsid protein.
Background Cellulitis has many clinical mimickers (pseudocellulitis), which leads to frequent misdiagnosis. Objective To create a model for predicting the likelihood of lower extremity cellulitis. ...Methods A cross-sectional review was performed of all patients admitted with a diagnosis of lower extremity cellulitis through the emergency department at a large hospital between 2010 and 2012. Patients discharged with diagnosis of cellulitis were categorized as having cellulitis, while those given an alternative diagnosis were considered to have pseudocellulitis. Bivariate associations between predictor variables and final diagnosis were assessed to develop a 4-variable model. Results In total, 79 (30.5%) of 259 patients were misdiagnosed with lower extremity cellulitis. Of the variables associated with true cellulitis, the 4 in the final model were asymmetry (unilateral involvement), leukocytosis (white blood cell count ≥10,000/uL), tachycardia (heart rate ≥90 bpm), and age ≥70 years. We converted these variables into a points system to create the ALT-70 cellulitis score as follows: Asymmetry (3 points), Leukocytosis (1 point), Tachycardia (1 point), and age ≥70 (2 points). With this score, 0-2 points indicate ≥83.3% likelihood of pseudocellulitis, and ≥5 points indicate ≥82.2% likelihood of true cellulitis. Limitations Prospective validation of this model is needed before widespread clinical use. Conclusion Asymmetry, leukocytosis, tachycardia, and age ≥70 are predictive of lower extremity cellulitis. This model might facilitate more accurate diagnosis and improve patient care.
Measurements of neutrophil activities such as cell migration and phagocytosis are generally performed using low-content bulk assays, which provide little detail activity at the single cell level, or ...flow cytometry methods, which have the single cell resolution but lack perspective on the kinetics of the process. Here, we present a microfluidic assay for measuring the essential functions that contribute to the antimicrobial activity of neutrophils: migration towards the target, and killing of microbes. The assay interrogates the interactions between isolated human neutrophils and populations of live, proliferating microbes. The outcome is measured in a binary mode that is reflective of in vivo infections, which are either cleared or endure the host response. The outcome of the interactions is also characterized at single cell resolution for both the neutrophils and the microbes. We applied the assay to test the response of neutrophils from intensive care patients to live Staphylococcus aureus, and observed alterations of antimicrobial neutrophil activity in patients, including those with sepsis. By directly measuring neutrophil activity against live targets at high spatial and temporal resolution, this assay provides unique insights into the life-or-death contest shaping the outcome of interactions between populations of neutrophils and microbes.
Warmth is a characteristic but nondiagnostic feature of cellulitis. We assessed the diagnostic utility of skin surface temperature in differentiating cellulitis from pseudocellulitis. Adult patients ...presenting to the emergency department of a large urban hospital with presumed cellulitis were enrolled. Patients were randomized to dermatology consultation (n = 40) versus standard of care (n = 32). Thermal images of affected and unaffected skin were obtained for each patient. Analysis was performed on dermatology consultation patients to establish a predictive model for cellulitis, which was then validated in the other cohort. Of those evaluated by dermatology consultation, pseudocellulitis was diagnosed in 28%. Cellulitis patients had an average maximum affected skin temperature of 34.1°C, which was 3.7°C warmer than the corresponding unaffected area (95% confidence interval = 2.7–4.8°C, P < 0.00001). Pseudocellulitis patients had an average maximum affected temperature of 31.5°C, which was 0.2°C warmer than the corresponding unaffected area (95% confidence interval = –1.1 to 1.5°C, P = 0.44). Temperature differences between sites were greater in cellulitis patients than in pseudocellulitis patients (3.7 vs. 0.2°C, P = 0.002). A logistic regression model showed that a temperature difference of 0.47°C or greater conferred a 96.6% sensitivity, 45.5% specificity, 82.4% positive predictive value, and 83.3% negative predictive value for cellulitis diagnosis. When validated in the other cohort, this model gave the correct diagnosis for 100% of patients with cellulitis and 50% of those with pseudocellulitis. A difference threshold of 0.47°C or greater between affected and unaffected skin showed an 87.5% accuracy in cellulitis diagnosis.
Therapy for Cellulitis Raff, Adam B; Kroshinsky, Daniela
JAMA : the journal of the American Medical Association,
2016-Nov-15, Letnik:
316, Številka:
19
Journal Article
Abstract The development of novel clinical tools to combat cancer is an intense field of research and recent efforts have been directed at the identification of proteins that may provide diagnostic, ...prognostic and/or therapeutic applications due to their restricted expression. To date, a number of protein candidates have emerged as potential clinical tools in the treatment of prostate cancer. Discovered over ten year ago, prostate stem cell antigen (PSCA) is a cell surface antigen that belongs to the Ly-6/Thy-1 family of glycosylphosphatidylinositol-anchored proteins. PSCA is highly overexpressed in human prostate cancer, with limited expression in normal tissues, making it an ideal target for both diagnosis and therapy. Several studies have now clearly correlated the expression of PSCA with relevant clinical benchmarks, such as Gleason score and metastasis, while others have demonstrated the efficacy of PSCA targeting in treatment through various modalities. The purpose of this review is to present the current body of knowledge about PSCA and its potential role in the treatment of human prostate cancer.