Erin G. Brooks

Valves of the deep venous system: an overlooked risk factor

Deep venous valves are frequent sites of deep venous thrombosis initiation. However, the possible contribution of the valvular sinus endothelium has received little attention in studies of thrombosis risk. We hypothesized that the endothelium of valve sinus differs from that of vein lumen with up-regulation of anticoagulant and down-regulation of procoagulant activities in response to the local environment. In pursuit of this hypothesis, we quantified endothelial protein C receptor (EPCR), thrombomodulin (TM), and von Willebrand factor (VWF) by immunofluorescence in great saphenous veins harvested at cardiac bypass surgery. We found significantly increased expression of EPCR and TM in the valvular sinus endothelium as opposed to the vein lumenal endothelium, and the opposite pattern with VWF (paired t test for TM and EPCR, each P < .001; for VWF, P = .01). These data support our hypothesis and suggest that variation in valvular sinus thromboresistance may be an important factor in venous thrombogenesis.

Validation of HLAMatchmaker algorithm in identifying acceptable HLA mismatches for thrombocytopenic patients refractory to platelet transfusions

BACKGROUND: HLAMatchmaker (HLAMM) is an algorithm that determines donor‐recipient histocompatibility based on HLA type. This study determines the effectiveness of HLAMM in identifying suitable platelet (PLT) donors for refractory patients.

Rat Indwelling Urinary Catheter Model of Candida albicans Biofilm Infection

ABSTRACT Indwelling urinary catheters are commonly used in the management of hospitalized patients. Candida can adhere to the device surface and propagate as a biofilm. These Candida biofilm communities differ from free-floating Candida, exhibiting high tolerance to antifungal therapy. The significance of catheter-associated candiduria is often unclear, and treatment may be problematic considering the biofilm drug-resistant phenotype. Here we describe a rodent model for the study of urinary catheter-associated Candida albicans biofilm infection that mimics this common process in patients. In the setting of a functioning, indwelling urinary catheter in a rat, Candida proliferated as a biofilm on the device surface. Characteristic biofilm architecture was observed, including adherent, filamentous cells embedded in an extracellular matrix. Similar to what occurs in human patients, animals with this infection developed candiduria and pyuria. Infection progressed to cystitis, and a biofilmlike covering was observed over the bladder surface. Furthermore, large numbers of C. albicans cells were dispersed into the urine from either the catheter or bladder wall biofilm over the infection period. We successfully utilized the model to test the efficacy of antifungals, analyze transcriptional patterns, and examine the phenotype of a genetic mutant. The model should be useful for future investigations involving the pathogenesis, diagnosis, therapy, prevention, and drug resistance of Candida biofilms in the urinary tract.

Host Contributions to Construction of Three Device-Associated Candida albicans Biofilms

ABSTRACT Among the most fascinating virulence attributes of Candida is the ability to transition to a biofilm lifestyle. As a biofilm, Candida cells adhere to a surface, such as a vascular catheter, and become encased in an extracellular matrix. During this mode of growth, Candida resists the normal immune response, often causing devastating disease. Based on scanning electron microscopy images, we hypothesized that host cells and proteins become incorporated into clinical biofilms. As a means to gain an understanding of these host-biofilm interactions, we explored biofilm-associated host components by using microscopy and liquid chromatography-mass spectrometry. Here we characterize the host proteins associated with several in vivo rat Candida albicans biofilms, including those from vascular catheter, denture, and urinary catheter models as well as uninfected devices. A conserved group of 14 host proteins were found to be more abundant during infection at each of the niches. The host proteins were leukocyte and erythrocyte associated and included proteins involved in inflammation, such as C-reactive protein, myeloperoxidase, and alarmin S100-A9. A group of 59 proteins were associated with both infected and uninfected devices, and these included matricellular and inflammatory proteins. In addition, site-specific proteins were identified, such as amylase in association with the denture device. Cellular analysis revealed neutrophils as the predominant leukocytes associating with biofilms. These experiments demonstrate that host cells and proteins are key components of in vivo Candida biofilms, likely with one subset associating with the device and another being recruited by the proliferating biofilm.

Principles and Pitfalls: a Guide to Death Certification.

Death certificates serve the critical functions of providing documentation for legal/administrative purposes and vital statistics for epidemiologic/health policy purposes. In order to satisfy these functions, it is important that death certificates be filled out completely, accurately, and promptly. The high error rate in death certification has been documented in multiple prior studies, as has the effectiveness of educational training interventions at mitigating errors. The following guide to death certification is intended to illustrate some basic principles and common pitfalls in electronic death registration with the goal of improving death certification accuracy.

Testing for Infectious Diseases in Sudden Unexpected Infant Death: A Survey of Medical Examiner and Coroner Offices in the United States

OBJECTIVES To determine interoffice variability in routinely performed sudden unexpected infant death (SUID) postmortem studies for infection and to assess availability and perceived utility of various tests of infectious diseases. STUDY DESIGN Online surveys were sent to all 154 offices of US medical examiners and coroners serving populations >300,000 people. Surveys included a set of potential laboratory tests for infectious disease. Respondents were asked to select which tests were available in their offices, and which tests were performed routinely in SUIDs vs which tests should be performed routinely. RESULTS Of the 45 complete responses, 4.4% did not routinely perform histology, 8.9% did not routinely perform viral studies (ie, culture or molecular diagnostics), 22.2% did not routinely perform blood cultures, 26.7% did not routinely perform lung bacterial cultures, and 44.4% did not routinely perform cerebrospinal fluid cultures. CONCLUSIONS Our findings suggest that there is considerable interoffice variability with testing for infectious diseases in SUIDs. This appeared to be largely the result of a perceived lack of testing utility rather than a lack of test availability. Evidence-based practice guidelines regarding the interpretation of microbial testing results, as well as common testing protocols/algorithms, may lead to more accurate and standardized data, thus improving SUID investigation and surveillance.

Eosinophilic Coronary Periarteritis with Arterial Dissection: The Mast Cell Hypothesis.

A subset of coronary arterial dissections is associated with eosinophilic coronary periarteritis (ECPA); however, the pathogenesis of the process remains unclear. Mast cells normally reside in coronary arterial adventitia and are known mediators of eosinophilic inflammatory conditions such as type I hypersensitivity reactions. We report two cases in which coronary arterial dissection with ECPA was detected at autopsy. Tryptase, CD68, CD4, CD8, and CD1a immunohistochemical staining was performed to better characterize inflammation. While eosinophils represented a prominent periadventitial inflammatory cell, there were slightly more lymphocytes: CD4/CD8 ratios were within expected reference ranges. There were moderate numbers of macrophages, and few neutrophils or dendritic cells. Numbers of mast cells in dissected versus nondissected sections were compared: adventitial mast cell densities were threefold higher in dissected portions and showed a trend toward increased degranulation. These findings suggest that mast cells may play a role in orchestrating inflammation in cases of ECPA.

Are Youth-Only Motorcycle Helmet Laws Better than None at All?

Introduction:The trend in state motorcycle helmet laws has been a reduction from universal coverage requiring all riders to wear helmets, to partial coverage requiring only younger riders to wear helmets. In the current study we evaluate whether partial helmet laws reduce motorcycle fatalities and increase helmet compliance among young riders. Materials and Methods:We compared a decade of motorcycle fatalities from the only 3 states with no helmet laws (New Hampshire, Iowa, Illinois) to 3 states with ≤17-year-old partial helmet laws (Connecticut, Indiana, Wisconsin). We excluded highway speeds, blood alcohol laws, and minimum legal drinking age as being significant variables. Results:Overall, there was no significant difference in the average fatality rate per 10,000 motorcycle registrations for ≤17-year-old riders in partial helmet law states versus no helmet law states (P = 0.45). Furthermore, there was no significant difference in the helmet wearing rate of ≤17-year-old fatalities in partial helmet law versus no helmet law states (P = 0.79). Conclusions:Partial helmet laws neither significantly reduce fatality rates nor increase helmet compliance rates among young riders. A partial helmet law is roughly equivalent to none at all; only universal helmet laws have been shown to effectively protect young motorcyclists.

Autopsy Biosafety: Recommendations for Prevention of Meningococcal Disease

Introduction: As invasive meningococcal disease progresses rapidly, often affects youth, and has a fairly high mortality rate, such cases are likely to fall under medical examiner/coroner (ME/C) jurisdiction. Morgue personnel may be at risk of contracting secondary meningococcal disease. We review the current scientific literature regarding Neisseria meningitidis infection and provide recommendations for the prevention of meningococcal disease at autopsy. Methods: A PubMed search utilizing applicable medical subject heading terms was performed retrieving articles for review from the preceding two decades. Pertinent current guidelines from multiple national organizations were also retrieved. Results: Invasive meningococcal disease is transmitted by direct contact with large respiratory droplets or oral secretions. While a surgical mask would normally provide adequate protection from large droplet spread, it does not prevent inhalation of smaller aerosolized particles such as those generated at autopsy. Prosectors are advised to routinely wear N-95 respirator masks or powered respirator hoods. All published cases of secondary meningococcal disease transmission to healthcare workers invariably arose in scenarios in which face masks/respirators were not employed; none of these cases involved meningococcal disease transmission to ME/C or other morgue staff. Discussion: In the event that no mask—or inadequate coverage such as a surgical mask—is employed during autopsy of a decedent suspected/confirmed to have invasive meningococcal disease, antibiotic prophylaxis is advisable. Assuming appropriate personal protective equipment is utilized, chemoprophylaxis is unnecessary. Routine meningococcal vaccination is not recommended, except for ME/C with specified immunocompromising conditions or traveling to hyperendemic/endemic meningococcal regions. Acad Forensic Pathol. 2018 8(2): 328-339

Serratia marcescens Bacteremia: Nosocomial Cluster Following Narcotic Diversion

OBJECTIVE To describe the investigation and control of a cluster of Serratia marcescens bacteremia in a 505-bed tertiary-care center. METHODS Cluster cases were defined as all patients with S. marcescens bacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio. RESULTS In total, 6 patients developed S. marcescens bacteremia within 48 hours after admission within the above period. Of these, 5 patients had identical Serratia isolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employees job was terminated. CONCLUSION Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting. Infect Control Hosp Epidemiol 2017;38:1027-1031.