Richard S.P. Huang

Colorimetric sensor array allows fast detection and simultaneous identification of sepsis-causing bacteria in spiked blood culture.

ABSTRACT Sepsis is a medical emergency demanding early diagnosis and tailored antimicrobial therapy. Every hour of delay in initiating effective therapy measurably increases patient mortality. Blood culture is currently the reference standard for detecting bloodstream infection, a multistep process which may take one to several days. Here, we report a novel paradigm for earlier detection and the simultaneous identification of pathogens in spiked blood cultures by means of a metabolomic “fingerprint” of the volatile mixture outgassed by the organisms. The colorimetric sensor array provided significantly faster detection of positive blood cultures than a conventional blood culture system (12.1 h versus 14.9 h, P < 0.001) while allowing for the identification of 18 bacterial species with 91.9% overall accuracy within 2 h of growth detection. The colorimetric sensor array also allowed for discrimination between unrelated strains of methicillin-resistant Staphylococcus aureus, indicating that the metabolomic fingerprint has the potential to track nosocomial transmissions. Altogether, the colorimetric sensor array is a promising tool that offers a new paradigm for diagnosing bloodstream infections.

Therapeutic plasmapheresis and red blood cell exchange in a sickle cell trait patient with rhabdomyolysis.

We report a case of a 16‐year‐old African‐American male with sickle cell trait and a past medical history significant for asthma that was transferred to our hospital for management of respiratory failure. On the fourth day of hospitalization, the patient was found to have increased creatine kinase (CK) levels and urine myoglobin levels consistent with rhabdomyolysis. No clear etiology was identified. Aggressive standard hydration and urine alkalization were applied without response. On the sixth day of hospitalization, the patient underwent a 1–1.5 plasma volume therapeutic plasma exchange (TPE) resulting in a transient reduction of serum CK and myoglobin by 50%, which became elevated once again within 4 h. Since his clinical presentation resembles exertional rhabdomyolysis documented in patients with sickle cell trait, RBC exchange was performed. The patient tolerated the procedure without complications. In addition to his improved overall condition, the patients post‐exchange CK and serum myoglobin levels dropped dramatically without rebound. To our knowledge, this case represents the first reported case of TPE followed by RBC exchange in a SCT patient with rhabdomyolysis. J. Clin. Apheresis 2012.

Mobile Computing Platform With Decision Support Modules for Hemotherapy

OBJECTIVES We describe the development of a mobile computing platform (MCP) with a decision support module (DSM) for patients in our coagulation-based hemotherapy service. METHODS The core of our MCP consists of a Microsoft Excel spreadsheet template used to gather and compute data on cardiopulmonary bypass (CPB) patients intraoperatively. The DSM is embedded into the Excel file, where the user would enter in laboratory results, and through our 45 embedded algorithms, recommendations for transfusion products would be displayed in the Excel file. RESULTS The DSM has helped decrease the time it takes to come to a transfusion recommendation, helps double-check recommendations, and is an excellent tool for teaching. Furthermore, the problems that occur with a paper system have been eliminated, and we are now able to access this information easily and reliably. CONCLUSIONS The development and implementation of our MCP system has greatly increased the productivity and efficiency of our hemotherapy service.

High false-positive rate for monoclonal gammopathy using capillary electrophoresis (CAPILLARYS 2) alone

Capillary zone electrophoresis (CZE) is a newer method of performing serum protein electrophoresis and is considered to be faster and more efficient than agarose gel method. We decided to evaluate CZE as an efficient screening tool for monoclonal gammopathies, and we began recommending immunofixation studies in cases with such minor/subtle distortions to avoid missing monoclonal gammopathies.

Isolated mesenteric CD20-positive myeloid sarcoma

Extramedullary manifestations of acute myeloid leukemia (AML) include myeloid sarcomas (MS), which are tumor masses composed of myeloid blasts, with or without maturation, arising in any anatomic location other than the bone marrow (BM) [1]. With only case reports and small retrospective studies available, the incidence of MS is unclear [2, 3]. We present an unusual, diagnostically-challenging case of isolated mesenteric MS without BM involvement [2, 3].

Rapid Detection of the Active Cardiac Glycoside Convallatoxin of Lily of the Valley Using LOCI Digoxin Assay

OBJECTIVES To explore the luminescent oxygen channeling technology-based digoxin immunoassay (LOCI digoxin assay) for rapid detection of lily of the valley extract and convallatoxin. The potential in vitro binding of convallatoxin with Digibind was also evaluated. METHODS Aliquots of a drug-free serum pool and a digoxin serum pool were supplemented with lily of the valley extract or convallatoxin, and then apparent digoxin concentrations were measured using the LOCI digoxin assay. Mice were administered lily of the valley extract or 50 μg of convallatoxin, and digoxin concentrations in serum specimens were measured 1 and 2 hours after gavage. Aliquots of a serum pool supplemented with convallatoxin or lily of the valley extract were further supplemented with various concentrations of Digibind and free apparent digoxin concentrations were measured. RESULTS Apparent digoxin concentrations were observed when aliquots of a drug-free serum pool were supplemented with convallatoxin or lily of the valley extract, and also with convallatoxin or herbal extract. Bidirectional interference of convallatoxin and lily of the valley extract with serum digoxin measurement using the LOCI assay was also observed. Digibind was capable of binding convallatoxin in vitro. CONCLUSIONS LOCI digoxin assay can be used for rapid detection of convallatoxin, and Digibind can bind convallatoxin in vitro.

Histoplasmosis as a possible cause of retroperitoneal fibrosis and median arcuate ligament syndrome: A case report

INTRODUCTION Median arcuate ligament syndrome (MALS), a condition of poorly understood etiology, is caused by compression of the celiac artery by fibers of the median arcuate ligament. PRESENTATION OF CASE A 46-year-old man with chronic abdominal pain and weight loss was diagnosed with MALS and admitted for surgery. During surgery, extensive retroperitoneal fibrosis around the celiac artery and adjacent aorta was noted. Large necrotizing granulomas and budding yeast, both indicators of histoplasmosis, were found on pathologic evaluation of retroperitoneal tissue removed during surgery. DISCUSSION Histoplasma capsulatum may cause pulmonary fibrosis and fibrosing mediastinitis, and the organism may disseminate to reach various internal organs in the immunocompromised individual. Retroperitoneal histoplasmosis has been demonstrated in immunocompromised individuals in the past without retroperitoneal fibrosis. Our patient may have had chronic histoplasma infection of his retroperitoneal lymph nodes, triggering fibrosis in the area surrounding the adjacent celiac artery and abdominal aorta, thus leading to symptomatic MALS. CONCLUSION Histoplasma capsulatum, an organism that has demonstrated its capability to cause fibrosis elsewhere in the body, may play a causative role in MALS in our patient, given the finding of retroperitoneal fibrosis in conjunction with retroperitoneal lymph node histoplasma.

Overview of Bacteria

This chapter will deal with all common Gram-positive and Gram-negative bacteria, as well as Enterobacteriaceae, anaerobes, and mycobacteria and their role in infective patients. Drugs which are used in treating such infections will also be addressed.

Clinical and serological responses following plasmapheresis in bullous pemphigoid: Two case reports and a review of the literature

Plasmapheresis has been proven to be an effective treatment for a variety of conditions, especially those in which circulating antibodies are known or thought to be involved in pathogenesis. The current American Society For Apheresis (ASFA) guidelines1 make recommendations on 120 specific indications encompassing a total of 68 distinct disease processes. Among the autoimmune blistering disorders of the skin, pemphigus vulgaris is the sole entity included and plasmapheresis is considered a category IV indication (disorders in which published evidence demonstrates or suggests apheresis to be ineffective or harmful). In pemphigus vulgaris auto-antibodies are directed against the adhesion molecule desmoglein2, whereas in a related entity known as bullous pemphigoid (BP) auto-antibodies are targeted against the hemidesmosome components BP1803 and BP2304. Although no formal recommendation exists for BP, plasmapheresis has been deployed successfully as adjunctive therapy5–8. In describing our own institution’s recent experience in treating BP we add to the growing evidence supporting the use of plasmapheresis under appropriate conditions. We also include an examination of serial BP180 and BP230 titres measured by enzyme-linked immunosorbent assay (ELISA) during plasmapheresis therapy.

Development of colorimetric sensor array for diagnosis of tuberculosis through detection of urinary volatile organic compounds

BACKGROUND Top priorities for tuberculosis control and elimination include a simple, low-cost screening test using sputum and a non-sputum-based test in patients that do not produce sputum. The aim of this study was to evaluate the performance of a colorimetric sensor array (CSA) test, for analysis of volatile organic compounds in urine, in the diagnosis of pulmonary TB. MATERIAL AND METHODS Urine samples were collected from individuals suspected of having pulmonary TB in Western Kenya. Reference methods included MGIT culture and/or Xpert MTB/RIF nucleic acid amplification test on sputa. Fresh urine samples were tested with the CSA, with acid and base and without an additive. The CSA were digitally imaged, and the resulting colorimetric response patterns were used for chemometric analysis. Sensitivity, specificity, and negative (NPV) and positive predictive (PPV) values were determined for HIV-positive and HIV-negative patients. RESULTS In HIV-negative patients, the highest accuracy was obtained in urine samples pre-treated with a base, yielding a sensitivity, specificity, PPV, and NPV of 78.3% (65/83), 69.2% (54/78), 73.0% (n/89) and 75.0% (n/72). The highest sensitivity of 79.5% was achieved using sensor data from all three test conditions at a specificity of 65.4%. In HIV-positive subjects, the sensor performance was substantially lower with sensitivity, specificity, PPV, and NPV ranging from 48.3% to 62.3%, 54.1% to 74.0%, 55.9% to 64.2%, and 60.6% to 64.9%, respectively. CONCLUSION The CSA fingerprint of urine headspace volatiles showed moderate accuracy in diagnosing TB in HIV-negative patients, but the sensor performance dropped substantially in HIV-coinfected patients. Further development of TB-responsive CSA indicators may improve the accuracy of CSA urine assay.