IntBiotechnologies, LLC Congratulates to our experienced consultant Mrs. Anne M. Sill, MSHS for earning Master's Degree in Clinical and Translational Research from George Washington University. A wonderful addition for a remarkable career and educational background.
By Labmedica International staff writers
Posted on 22 May 2014
Field-applicable tests detecting asymptomatic Mycobacterium leprae infection or predicting progression to leprosy are urgently required to determine both cellular and humoral immunity.
Leprosy, a curable infectious disease caused by M. leprae that affects the skin and peripheral nerves, is one of the six diseases considered as a major threat in developing countries as continued transmission in endemic areas likely occurs from the large reservoir of individuals who are infected subclinically.
Infectious disease specialists at the Leiden University Medical Center (The Netherlands) with colleagues in Ethiopia recruited for their study human immunodeficiency virus (HIV)-negative, newly diagnosed untreated leprosy patients, and healthy endemic controls from October 2011 until November 2012. Leprosy was diagnosed based on clinical, bacteriological and histological observations and classified by a skin biopsy.
The combined diagnostic value of interferon (IFN)-γ induced protein 10 (IP-10), interleukin-10 (IL-10) and anti-Phenolic Glycolipid-I (PGL-I) antibodies was tested using M. leprae-stimulated blood of leprosy patients and endemic controls (EC). For reduction of the overall test-to-result time, the minimal whole blood assay time required to detect distinctive responses was investigated. To accommodate Lateral Flow Assays (LFAs) for field settings, dry-format LFAs for IP-10 and anti-PGL-I antibodies were developed allowing storage and shipment at ambient temperatures. Additionally, a multiplex LFA-format was applied for simultaneous detection of anti-PGL-I antibodies and IP-10. For improved sensitivity and quantitation, upconverting phosphor (UCP) reporter technology was applied in all LFAs.
After immunochromatography, LF strips are scanned in a Packard FluoroCount microtiter-plate reader (PerkinElmer; Waltham, MA, USA) adapted with an infrared laser. Upon IR excitation at 980 nm, UCP reporter particles emit green light detectable using a 550 nm band pass filter. For strip analysis in Ethiopia, a lightweight portable LF strip reader with UCP capability was used (UCP-Quant, an ESEQuant LFR reader custom adapted with IR diode; (QIAGEN Lake Constance GmbH; Stockach, Germany).
Single and multiplex UCP-LFAs correlated well with enzyme-linked immunosorbent assays (ELISAs) run in parallel. The performance of dry reagent assays and portable, lightweight UCP-LF strip readers indicated excellent field-robustness. Notably, detection of IP-10 levels in stimulated samples allowed a reduction of the whole blood assay time from 24 hours to six hours. Moreover, IP-10/IL-10 ratios in unstimulated plasma differed significantly between patients and endemic controls, indicating the feasibility to identify M. leprae infection in endemic areas.
The authors concluded that dry-format UCP-LFAs are low-tech, robust assays allowing detection of relevant cytokines and antibodies in response to M. leprae in the field. The high levels of IP-10 and the required shorter whole blood assay time, render this cytokine useful to discriminate between leprosy patients and endemic controls. The study was published on May 8, 2014, in the journal Public Library of Science Neglected Tropical Diseases.
Image: Packard FluoroCount microtiter-plate reader adapted to read lateral flow strips (Photo courtesy of PerkinElmer).
Image: The ESEQuant Lateral Flow Assay Reader (Photo courtesy of Qiagen).
Posted: May 19, 2014
Over the past decade, the biological laboratory has become an increasingly digitally enhanced place. These days a skills section of a CV is more likely to include various instruments and software systems than a list of molecular biology or cell culture techniques. It’s not just that the volume of data being captured electronically is greater than ever before; data are also being generated and diversifying at ever-increasing speeds. In a paper-based lab, those electronic data are simply printed out and pasted into an actual notebook for IP capture, commonly referred to by scientists as “arts and crafts time.”
With the advent of the Electronic Laboratory Notebook (ELN), this “arts and crafts” approach has been replaced by electronically copying and pasting or sometimes “printing” the files (Word, Excel, PowerPoint, GraphPad, DNA sequence files, etc.) as the mechanism for collating the data. This process typically has some electronic signature functionality, although often legal departments still demand that the ELN pages be printed and signed for, maintaining IP in the traditional way. At least in this manner, the content is searchable, however basic the search capabilities may be. It’s what we call a “sticker book” ELN. Read More
The 17 neglected tropical diseases
The neglected tropical diseases result from four different causative pathogens:
Johns Hopkins Medicine. "Staying power of HIV-fighting enzyme figured out." ScienceDaily. ScienceDaily, 1 May 2014.
Biochemists have figured out what is needed to activate and sustain the virus-fighting activity of an enzyme found in CD4+ T cells, the human immune cells infected by HIV. The discovery could launch a more effective strategy for preventing the spread of HIV.
Four identical subunits make up the antiviral SAMHD1 enzyme. Each subunit must bind a molecule of GTP at its A1 site and an A, T, C or G nucleotide at its A2 site before the enzyme can break down additional A, T, C and G nucleotides at its S sites.
Credit: Stivers Lab, Johns Hopkins Medicine
Johns Hopkins biochemists have figured out what is needed to activate and sustain the virus-fighting activity of an enzyme found in CD4+ T cells, the human immune cells infected by HIV. The discovery could launch a more effective strategy for preventing the spread of HIV in the body with drugs targeting this enzyme, they say.
A summary of their work was published online on April 21 in the journal Proceedings of the National Academy of Sciences. Read More
E. C. Hansen, K. J. Seamon, S. L. Cravens, J. T. Stivers. GTP activator and dNTP substrates of HIV-1 restriction factor SAMHD1 generate a long-lived activated state. Proceedings of the National Academy of Sciences, 2014; DOI:10.1073/pnas.1401706111
By Labmedica International staff writers
Posted on 30 Apr 2014
The incidence of patient identification errors, including mislabeled and misidentified specimens, is thought to be unacceptably high in clinical laboratories.
The best data on errors in USA laboratories is derived from three separate College of American Pathologists (CAP; Northfield, IL, USA) Q-Probe studies, in which the reported rates of mislabeled specimens were 0.39/1,000 in 120 institutions in 2006, 0.92/1,000 in 147 clinical laboratories in 2008, and 1.12% of blood bank specimens in 122 clinical laboratories.
Laboratory scientists at the ARUP Laboratories (Salt Lake City, UT, USA) have examined the problem of misidentification and have suggested some possible solutions. One approach is the single piece flow and this concept has significant error-proofing potential for labeling tasks at relatively low cost. They suggest that to prevent errors during collection and processing, avoid having specimens from multiple patients in the active work area at the same time. Similarly, avoid using strips of labels from a label printer with labels for multiple patients that must be matched to specimens and if using an automated aliquoting device, be sure that the label exactly duplicates the barcode label from the primary tube to facilitate error detection. Read More