Loop-Mediated Isothermal Amplification on Paper Microfluidic Chips for Highly Sensitive and Specific Zika Virus Detection Using Smartphone

Zika virus (ZIKV) infection may cause serious birth defects and is a critical concern for women of child-bearing age in affected regions. A simple, portable, and easy-to-use ZIKV detection method would enable point-of-care testing, which may aid in prevention of the spread of the virus. Herein, we describe a reverse transcription isothermal loop-mediated amplification (RT-LAMP) method that detects the presence of ZIKV RNA in complex samples (e.g., blood, urine, and tap water). Phenol red is the colorimetric indicator of successful amplification. Color changes based on the amplified RT-LAMP product from the presence of viral target are monitored using a smartphone camera under ambient light conditions. A single viral RNA molecule per μL can be detected in as quickly as 15 min using this method with 100% sensitivity and 100% specificity in blood and tap water, while 100% sensitivity and 67% specificity in urine. This platform can also be used to identify other viruses including SARS-CoV-2 and improve the current state of field-based diagnostics.

DNA Methylation Analysis from Body Fluids

Circulating cell-free DNA (ccfDNA) can be found in various body fluids, i.e., blood (serum and plasma), urine, pleural effusions, and ascites. While ccfDNA predominantly originates from physiological processes, a fraction might be related to pathological events, e.g., cancer. Aberrant DNA methylation, which is considered a hallmark of cancer, can be assessed accurately in ccfDNA. Consequently, DNA methylation testing in body fluids represents a powerful diagnostic tool in the clinical management of malignant diseases. Frequently, however, the total amount of disease-related ccfDNA in a sample is low and masked by an excess of physiological ccfDNA. Thus, DNA methylation analysis of tumor-derived DNA is challenging, and high volumes of body fluids need to be analyzed in order to ensure a sufficient abundance of the analyte in the test sample. DNA methylation assays are usually based on prior conversion of cytosines to uracils by means of bisulfite. This reaction takes place under harsh chemical conditions leading to DNA degradation and therefore necessitates a proper DNA purification before downstream analyses. This article describes a protocol which allows for the preparation of ultra-pure bisulfite-converted DNA from up to 3 ml blood plasma and serum, which is well suited for subsequent molecular biological techniques, e.g., methylation-specific real-time PCR.

L-Arginine ethylester enhances in vitro amplification of PrP(Sc) in macaques with atypical L-type bovine spongiform encephalopathy and enables presymptomatic detection of PrP(Sc) in the bodily fluids

Protease-resistant, misfolded isoforms (PrP(Sc)) of a normal cellular prion protein (PrP(C)) in the bodily fluids, including blood, urine, and saliva, are expected to be useful diagnostic markers of prion diseases, and nonhuman primate models are suited for performing valid diagnostic tests for human Creutzfeldt-Jakob disease (CJD). We developed an effective amplification method for PrP(Sc) derived from macaques infected with the atypical L-type bovine spongiform encephalopathy (L-BSE) prion by using mouse brain homogenate as a substrate in the presence of polyanions and L-arginine ethylester. This method was highly sensitive and detected PrP(Sc) in infected brain homogenate diluted up to 10(10) by sequential amplification. This method in combination with PrP(Sc) precipitation by sodium phosphotungstic acid is capable of amplifying very small amounts of PrP(Sc) contained in the cerebrospinal fluid (CSF), saliva, urine, and plasma of macaques that have been intracerebrally inoculated with the L-BSE prion. Furthermore, PrP(Sc) was detectable in the saliva or urine samples as well as CSF samples obtained at the preclinical phases of the disease. Thus, our novel method may be useful for furthering the understanding of bodily fluid leakage of PrP(Sc) in nonhuman primate models.

Clinical presentation and cytopathologic features of malignant pericardial cytology: a single institution analysis spanning a 29-year period

INTRODUCTION

Pericardial effusion can be a consequence of various diseased states, including infection, autoimmune disease, renal failure, myocardial disease, and neoplasms. Although multiple case reports of malignancy-associated pericardial effusion have been published, few database analyses are available in these published reports. In this study, we retrospectively reviewed 1022 cytology cases and assessed malignancy-associated pericardial effusion.

MATERIALS AND METHODS

We reviewed our cytology reports for pericardial effusion cases from January 1, 1983 to July 31, 2013. These cases were classified as benign, atypical, malignant, and nondiagnostic. The malignant cases were further characterized based on either immunohistochemical staining results or patients' history.

RESULTS

We identified 1022 cases and grouped them as follows: 824 benign (80.6%), 38 atypical (3.7%), 158 malignant (15.4%), and 2 unsatisfactory (0.1%). Malignant cases included 131 adenocarcinoma (82.9%), 12 lymphoma (7.9%), 6 poorly differentiated carcinoma (3.8%), 4 mesothelioma (2.5%), 2 squamous cell carcinoma (1.3%), 1 melanoma (0.6%), 1 sarcoma (0.6%), and 1 small cell carcinoma (0.6%). Of these 131 adenocarcinomas, 83 cases had clinical history and/or immunohistochemical study available for further classification, which included 44 lung, 18 breast, 7 esophagogastric adenocarcinomas, 6 adenocarcinomas of unknown primary sites, 5 ovarian, and 2 rectal adenocarcinomas. The clinical presentation, prognosis, and cytopathologic features for malignant pericardial effusions are summarized.

CONCLUSIONS

In this study, 15.4% of pericardial effusion cases were caused by metastatic malignancy, with lung adenocarcinoma being the most common primary site, followed by breast and lymphoma. Relatively young patients are affected, with average age being 56 years. Prognosis is poor for patients with malignant pericardial effusion. However, targeted therapy showed improved survival.