Global Medical Discovery features paper: Digital PCR for direct quantification of viruses without DNA extraction

Significance Statement

 DNA extraction before amplification is considered an essential step for the measurement of any DNA targets, as it releases the DNA from cells, viruses and bacteria and eliminates any PCR-inhibitory substances that are initially present in the matrix. However, different extraction procedures have different DNA yields and efficiency of inhibitory substances removal, consequently reducing quantification accuracy and hampering inter-laboratory comparability of data. In the past some viruses and bacteria have already been directly quantified using qPCR without DNA extraction, however drawbacks related to the qPCR formats such as susceptibility to inhibitory substances and dependence on the calibration material probably hampered the precise and reliable measurements of the actual concentrations therefore direct quantification using dPCR has a potential to overcome these.

To investigate the potential of digital PCR for direct quantification of viruses, human cytomegalovirus (HCMV) has been quantified without prior extraction using two digital PCR platforms and two standard materials. Up to 50% higher concentrations of DNA targets were measured using direct quantification compared to concentrations measured after the extraction step. Results of direct quantification were equally or even more repeatable, than that of the extracted DNA.

Direct quantification can be used to determine absolute DNA extraction efficiencies and for the evaluation of the influence of matrix on the extraction yield and therefore supports laboratories in decisions on fit for purpose extraction methods as well as in comparability of results especially in diagnostics.

Direct quantification is also a valuable approach for the characterization of reference materials and materials for external quality assurance schemes that underpin quality of results in diagnostics of human pathogens. This approach is of particular importance in the field of plant pathogen diagnostics, where no reference materials are commercially available as it enables preparation of well characterized in-house reference materials. 

About The Author

Jernej Pavšič is a PhD student at the National Institute of Biology in Ljubljana, Slovenia.

 His research is focused on evaluation of novel nucleic-acid based techniques to standardize and improve diagnostics of human pathogens, enhance characterisation of reference materials and facilitate cancer diagnostics. He is especially interested is exploring capabilities of digital PCR and high-throughput qPCR.

About The Author

Jana Žel is head of the genetically modified organisms group at the National Institute of Biology, Slovenia. She has been working for several years on cutting-edge approaches and methods for GMO testing and also the establishment of an internationally harmonized and metrologically sound system for molecular analyses.

About The Author

Mojca Milavec is deputy head of GMO detection at the National Institute of Biology in Ljubljana, Slovenia, where she is responsible for introduction of new methods, in house validations and staff training for the National Reference Laboratory for GMO detection. Her research is focused on challenges associated with established and novel technologies for nucleic acid measurements as well as standardization and quality control of these technologies.

Journal Reference

Anal Bioanal Chem. 2016;408(1):67-75.

Pavšič J^1,2, Žel J³, Milavec M³.

Show Affiliations

1. Department of Biotechnology and Systems Biology, National Institute of Biology, Večna pot 111, 1000, Ljubljana, Slovenia. jernej.pavsic@nib.si.
2. Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000, Ljubljana, Slovenia. jernej.pavsic@nib.si.
3. Department of Biotechnology and Systems Biology, National Institute of Biology, Večna pot 111, 1000, Ljubljana, Slovenia.

 

Abstract

DNA extraction before amplification is considered an essential step for quantification of viral DNA using real-time PCR (qPCR). However, this can directly affect the final measurements due to variable DNA yields and removal of inhibitors, which leads to increased inter-laboratory variability of qPCR measurements and reduced agreement on viral loads. Digital PCR (dPCR) might be an advantageous methodology for the measurement of virus concentrations, as it does not depend on any calibration material and it has higher tolerance to inhibitors.  DNA quantification without an extraction step (i.e. direct quantification) was performed here using digital PCR and two different human cytomegalo virus whole-virus materials. Two digital PCR platforms were used for this direct quantification of the viral DNA, and these were compared with quantification of the extracted viral DNA in terms of yield and variability. Direct quantification of both whole-virus materials present in simple matrices like cell lysate or Tris-HCl buffer provided repeatable measurements of virus concentrations that were probably in closer agreement with the actual viral load than when estimated through quantification of the extracted DNA. Direct digital PCR quantification of other viruses, reference materials and clinically relevant matrices is now needed to show the full versatility of this very promising and cost-efficient development in virus quantification.

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Global Medical Discovery features paper: Establishment and characterization of a novel VEGF-producing HHV-8-unrelated PEL-like lymphoma cell line, OGU1

Significance Statement

Under immunocompromised conditions such as human immunodeficiency virus (HIV) infection, human herpesvirus-8 (HHV-8) is associated with the development extracavitary large B-cell lymphoma, a condition known as primary effusion lymphoma (PEL). Recently, body cavity-based lymphomas have emerged that resemble PEL, but are not associated with HHV-8 and develop in the absence of HIV infection; these have been termed HHV-8-unrelated PEL-like lymphoma. HHV-8-unrelated PEL-like lymphomas show distinct features from PEL, including expression of pan-B cell markers, frequent occurrence in elderly patients, and a more favorable response to therapy. However, this type of lymphoma also shows some heterogeneity with respect to its clinical manifestation, and its pathophysiology is largely unknown. To elucidate the oncogenetic mechanism of this type of lymphoma, we established and characterized a novel cell line, named OGU1, from a patient with HHV-8-unrelated PEL-like lymphoma with ascites development.

OGU1 cells expressed CD20 and CD19 pan-B cell markers and revealed a rearrangement of the immunoglobulin heavy chain gene identical to the parental tumor cells. HHV-8 mRNA and its encoded product LANA-1 were not detected in either OGU1 cells or the parental tumors, which is compatible with the typical features of HHV-8-unrelated PEL-like lymphoma. Vascular endothelial growth factor (VEGF) plays a pivotal role in the development of a variety of tumors, including hematologic malignancies, and has been reported as a useful marker for predicting the prognosis of non-Hodgkin’s lymphomas. We found that the OGU1 cells produced abundant VEGF and expressed VEGF receptor-1 at both the mRNA and protein levels. Intriguingly, monoclonal antibodies against VEGF or inhibitors for the VEGF receptor caused growth retardation of the cells, indicating that VEGF, at least in part, promotes the proliferation or survival of OGU1 cells thorough an autocrine mechanism. Furthermore, we found activation of tyrosine kinases (Src and Lyn), PKCa, and S6K1 signaling molecules, and high expression levels of miRNAs such as the miR-17-92 cluster, suggesting a role of these molecules in the lymphomagenesis of the cells. OGU1 cells may be a useful model for investigating the tumor biology of this unique type of lymphoma.  

FigureLegend: OGU1 cells were negative for HHV-8 (immunostaining with anti-HHV-8 antibody, left panel).

VEGF mRNA expression in OGU1 cell line was detected by RT-PCR (right panel). Arrow indicates VEGF mRNA. S; sample (OGU1), PC; positive control, NC; normal control, MQ; Milli-Q, M; size marker.

About The Author

Kiyotaka Kawauchi completed his residency in internal medicine at Tokyo Women’s Medical University Daini Hospital, and then proceeded to a specialty in hematology and oncology. He received a Ph.D in medicine from Tokyo Women’s Medical University in 1988, in which he studied the mechanism of interferon-induced human natural killer cell activation. He also conducted research on B-cell antigen receptor signaling at the Best Institute of the University of Toronto in Canada from 1991 to 1994 as a postdoctoral fellow. He obtained the position of Associate professor at Tokyo Women’s Medical University Medical Center East in 1999. He is now a director of the Nishiogu Clinic. He also serves as a councilor of the Japanese Society of Hematology and is a member of the editorial board of Case Reports in Hematology.  

Journal Reference

Eur J Haematol. 2016 Feb;96(2):144-51.

Kawauchi K^1,2, Ogasawara T¹, Aiba M³, Fujibayashi M³, Sanaka T⁴, Sakura H¹, Shibuya M^5,6.

Show Affiliations

1. Medical Center East, Department of Medicine, Tokyo Women’s Medical University, Tokyo, Japan.
2. Nishiogu Clinic, Tokyo, Japan.
3. Medical Center East, Department of Surgical Pathology, Tokyo Women’s Medical University, Tokyo, Japan.
4. Center of CKD and Lifestyle Related Diseases, Edogawa Hospital, Ichikawa city, Japan.
5. Institute of Physiology and Medicine, Jobu University, Takasaki, Japan.
6. Institute of Medical Science, University of Tokyo, Tokyo, Japan. 

Abstract

Primary effusion lymphoma (PEL) is a rare B-cell lymphoma subtype that is characterized by lymphomatous effusion without the presence of masses, and it typically occurs in human immunodeficiency virus (HIV)-infected individuals. Lymphoma cells are universally positive for human herpesvirus 8 (HHV-8). Recently, a cavity-based effusion lymphoma that is similar to PEL without HHV-8 infection, called HHV-8-unrelated PEL-like lymphoma, has been reported in non-HIV-infected individuals. However, the pathophysiology of this lymphoma is largely undefined. We established a novel B-cell line OGU1 derived from a patient with HHV-8-unrelated PEL-like lymphoma. Notably, OGU1 cells produced vascular endothelial growth factor (VEGF) and expressed VEGF receptor 1, whose inhibitors retarded cell growth. Because VEGF acts as a vascular permeability and growth factor, it could play a role, at least in part, in the pathogenesis of this unique lymphoma. Thus, the OGU1 cell line is useful for the investigation of HHV-8-unrelated PEL-like lymphoma.

© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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Global Medical Discovery features paper: Development of green to near-infrared turn-on fluorescent probes for the multicolour imaging of nitroxyl in living systems

Journal Reference

Mater. Chem. B, 2016,4, 1263-1269.

Baoli Dong¹ , Kaibo Zheng² , Yonghe Tang¹ , Weiying Lin^1,2

Show Affiliations

1. Institute of Fluorescent Probes for Biological Imaging, School of Chemistry and Chemical Engineering, School of Biological Science, University of Jinan, Jinan, P. R. China
   E-mail: weiyinglin2013@163.com
2. State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan university, Changsha, P. R. China

Abstract

Nitroxyl (HNO) is one of the important reactive nitrogen species (RNS) and show significant biological activities with significant therapeutic potential. Herein, three novel turn-on probes (NP-1–3) based on structurally related dyes with different emission colors as fluorescent scaffolds have been developed for detecting HNO in biological systems. The probes exhibit high sensitivity, excellent selectivity, desirable performance at physiological pH and low cytotoxicity. By incubating living cells with these probes simultaneously, we demonstrate the multicolor imaging of HNO with emission colors in the range of green to near-infrared (NIR) in living systems for the first time. Furthermore, probe NP-3 responds to HNO with a significant turn-on NIR fluorescence signal upon excitation in the NIR region, and it is successfully applied for sensing HNO in living mice.

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Global Medical Discovery features paper: JNK mediates mouse liver injury through a novel Sab (SH3BP5) dependent pathway leading to inactivation of intramitochondrial Src

Significance Statement

Model of the pathway for the interplay of JNK and mitochondria in cell death. JNK is initially activated by the MAPK cascade either extrinsically by receptor signaling or intrinsically by organelle stress emanating from mitochondria, endoplasmic reticulum, or nucleus. Activated JNK translocates to the mitochondria, where it binds and phosphorylates Sab on the cytoplasmic side of the outer membrane. This leads to release of inactive SHP1 sequestered by Sab, which then is activated by p-Src and mediates inactivation of P-Y419Src, facilitated by the inner membrane DOK4 platform. Active Src maintains electron transport, whereas inactivation leads to impaired electron transport which promotes increased ROS release. The ROS release continues to activate upstream MAPK, leading to JNK activation in a self-sustaining loop, which accounts for JNK activation being sustained. In APAP toxicity, the amplified mitochondrial ROS from damaged mitochondria due to this loop promotes mitochondrial permeability pore opening and necrosis, whereas in TNF-induced apoptosis the sustained JNK activation is known to lead to enhanced activity of proapoptotic Bcl proteins and impairment of antiapoptotic Bcl proteins; the result is mitochondrial outer membrane permeabilization, which permits release of cytochrome c and other mitochondrial proteins, followed by caspase activation and apoptosis. The key feature is that the Sab-dependent effect of p-JNK on mitochondria through an intramitochondrial signaling pathway is the mechanism for sustained activation of p-JNK in the cytoplasm, which is necessary for cell death.

Abbreviations: ER, endoplasmic reticulum; ETC, electron transport chain; IM, inner membrane; MOMP, mitochondrial outer membrane permeabilization; MPT, mitochondrial permeability transition pore; OM, outer membrane.

About The Author

Professor Neil Kaplowitz

Holder of USC Associates/Thomas H. Brem Chair in Medicine and Budnick Chair in Liver Disease
Professor of Medicine and Chief, Division of Gastrointestinal and Liver Diseases, and Professor of Physiology and Biophysics, Keck School of Medicine of USC
Professor of Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy
Director, USC Research Center for Liver Disease 

About The Author

Sanda Win, MD, Ph.D.

Assistant Professor

USC Research Center for Liver Disease, Keck School of Medicine of USC, Los Angeles, California

About The Author

Tin Aung Than, M.D., Ph.D.

Assistant Professor

USC Research Center for Liver Disease, Keck School of Medicine of USC, Los Angeles, California

About The Author

Robert Min 

Journal Reference

Hepatology. 2016 Feb 4.

Win S¹, Than TA¹, Min RW¹, Aghajan M², Kaplowitz N¹.

Show Affiliations

1. USC Research Center for Liver Disease, Keck School of Medicine of USC, Los Angeles, California.
2. IONIS Pharmaceuticals, Carlsbad, California.

Abstract

Sustained JNK activation has been implicated in many models of cell death and tissue injury. P-JNK interacts with the mitochondrial outer membrane protein, Sab (SH3BP5). Using knockdown or liver specific deletion of Sab we aimed to elucidate the consequences of this interaction on mitochondrial function in isolated mitochondria and liver injury models in vivo. Respiration in isolated mitochondria was directly inhibited by P-JNK+ATP. Knockdown or liver specific knockout of Sab abrogated this effect and markedly inhibited sustained JNK activation and liver injury from acetaminophen (APAP) or TNF/galactosamine. We then elucidated an intramitochondrial pathway in which interaction of JNK and Sab on the outside of the mitochondria released SHP1 (PTPN6) from Sab in the inside of the mitochondrial outer membrane leading to its activation and transfer to the inner membrane where it dephosphorylates P-Y419Src (active) which required a platform protein, DOK4, on the inner membrane. Knockdown of mitochondrial DOK4 or SHP1 inhibited the inactivation of mitochondrial P-Src and the effect of P-JNK on mitochondria. Conclusions; the binding to and phosphorylation of Sab by P-JNK on the outer mitochondrial membrane leads to SHP1 and DOK4 dependent inactivation of P-Src on the inner membrane. Inactivation of mitochondrial Src inhibits electron transport and increases ROS release, which sustains JNK activation and promotes cell death and organ injury.

This article is protected by copyright. All rights reserved. © 2016 by the American Association for the Study of Liver Diseases.

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Global Medical Discovery features paper: Identification of a Japanese Lynch syndrome patient with large deletion in the 3′ region of the EPCAM gene

Journal Reference

Jpn J Clin Oncol. 2016 Feb;46(2):178-84.

Eguchi H¹, Kumamoto K², Suzuki O³, Kohda M⁴, Tada Y⁴, Okazaki Y⁴, Ishida H³. 

Show Affiliations

1. Division of Translation Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka eguchi@saitama-med.ac.jp.
2. Department of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University, Kawagoe Department of Organ Regulatory Surgery, Fukushima Medical University, Fukushima, Japan.
3. Department of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University, Kawagoe.
4. Division of Translation Research, Research Center for Genomic Medicine, Saitama Medical University, Hidaka.

 

Abstract

Germline deletion of the 3′ portion of the Epithelial Cell Adhesion Molecule (EPCAM) gene located 5′ upstream of MutS Homolog 2 (MSH2) is a novel mechanism for its inactivation in Lynch syndrome. However, its contribution in Japanese Lynch syndrome patients is poorly understood. Moreover, somatic events inactivating the remaining allele of MSH2 in cancer tissue have not been elucidated in Lynch syndrome patients with such EPCAM deletions. We identified a Japanese Lynch syndrome patient with colon cancer who evidenced germline deletion of a 4130 bp fragment of EPCAM encompassing exons 8 and 9 (c.859-672_*2170del). In normal colonic mucosa, two known fusion-transcripts ofEPCAM/MSH2 generated from the rearranged gene were observed and heterozygous methylation of the MSH2 gene promoter was detected. In cancer tissue, dense methylation of MSH2 was observed and MLPA analysis demonstrated somatic deletion of the remaining EPCAM allele including exon 9, indicating that somatic deletion of EPCAM is responsible for complete inactivation of MSH2.

© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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Global Medical Discovery features paper: An integrated hybrid microfluidic device for oviposition-based chemical screening of adult Drosophila melanogaster

Significance Statement

Model organisms play an important role in the cycle of drug discovery. Drosophila melanogaster is one of the invertebrate model organisms that has been extensively used to study human diseases and disorders. However, the widespread use of this organism has been impeded by the lack of automated and high throughput technologies for screening. In this article, we have developed a microfluidic device (shown schematically) consisting of porous agar with integrated networks of microchannels used to selectively infuse chemicals at desired concentrations to favorable locations in the device. We have used this technology to study the effect of zinc and acetic acid on oviposition or egg laying behavior of adult fruit flies. Our findings show that fruit flies are capable of sensing the concentration of chemicals in single-chemical assays and use this functionality to explore and select desirable oviposition sites in multi-chemical platforms. This technology can be used for screening drugs, studying learning and memory functions, and investigating biological pathways of oviposition in agricultural, drug discovery, biological, and medical applications.  

About The Author

Jacob C.K. Leung received his Bachelor of Engineering degree with honors distinction in Biomedical Engineering from Ryerson University, Toronto, ON, Canada. He obtained his Master of Science degree in Mechanical Engineering at York University under the supervision of Professor Pouya Rezai. His research focused on developing efficient microfluidic devices to perform toxicological assays on Drosophila melanogaster. He also gained expertise in developing sacrificial layer based microfabrication techniques to produce PDMS and composite PDMS micropillars and microbridges for sensor applications. In addition to his engineering background, Jacob is also pursuing higher education in Occupational Therapy at the University of Toronto. Integrating his engineering skills with rehabilitation medicine, Jacob’s research interests include developing person-centered assistive devices and automated, low-cost, and high-throughput biomedical diagnostic technologies for developmental biology, toxicology, and drug discovery. 

About The Author

Professor Arthur Hilliker completed his PhD at the University of British Columbia (1975) and pursued postdoctoral work at the University of Connecticut before joining CSIRO in Australia as a research scientist (1978) in the Division of Plant Industry. His first academic appointment was at University of Guelph in 1982 as an Assistant Professor, advancing through the ranks to Professor in 1993. Dr. Hilliker moved to York University to be the Chair of the Department of Biology in 2000. Dr. Hilliker has had a long standing record of service to the scientific community. He was the first person awarded the Young Scientist Award from the Genetics Society of Canada (1987). In 2005, he was again recognized by the Genetics Society of Canada with the Award of Excellence for lifetime scientific contributions to genetics. He was Co-Editor in Chief of the National Research Council of Canada Press journal Genome from 2007 until 2014. Since 2010 he has served on the Executive of the Canadian Society of Biochemistry and Molecular and Cell Biology (now renamed the Canadian Society of Molecular Biosciences) and is currently a Past President and Treasurer. His research is primarily although not entirely focused on using Drosophila as a model organism. His research covers a wide breadth of subject areas relating to genetics. 

About The Author

Professor Pouya Rezai is an emerging researcher in the area of microfluidics and Lab-on-a-Chip (LoC) devices. He is an Assistant Professor and the Graduate Program Director at the Department of Mechanical Engineering at York University. He received his Master of Science in Electrical Engineering from Chalmers University of Technology in 2008 and his PhD in Mechanical Engineering from McMaster University in 2012. Dr. Rezai was an NSERC Visiting Fellow at Public Health Agency of Canada before joining York University in July 2013. His research interest includes advancing micromachining and microfabrication techniques to develop LoC devices to study interactions between micro-particles, small biological substances and fluids in microenvironments. He has developed (i) LoC devices for quantitative investigation of neurobehavioral responses of bio-organisms (e.g., D. melanogaster, C. elegans, D. rerio) to electric, acoustic, or chemical cues; (ii) microfluidic platforms for multiplexed sorting of pathogens and microparticles in fluidic samples; and (iii) micro-electro-mechanical sensors for measuring properties of polymers and carbon nano-structures.

Journal Reference

Lab Chip. 2016 Feb 21;16(4):709-19.

Leung JC, Hilliker AJ, Rezai P.

Department of Mechanical Engineering, York University, BCEE 433B, 4700 Keele St, Toronto, ON M3J 1P3, Canada. prezai@yorku.ca.

Abstract

Chemical screening using Drosophila melanogaster (the fruit fly) is vital in drug discovery, agricultural, and toxicological applications. Oviposition (egg laying) on chemically-doped agar plates is an important read-out metric used to quantitatively assess the biological fitness and behavioral responses of Drosophila. Current oviposition-based chemical screening studies are inaccurate, labor-intensive, time-consuming, and inflexible due to the manual chemical doping of agar. In this paper, we have developed a novel hybrid agar-polydimethylsiloxane (PDMS) microfluidic device for single- and multi-concentration chemical dosing and on-chip oviposition screening of free-flying adult stage Drosophila. To achieve this, we have devised a novel technique to integrate agar with PDMS channels using ice as a sacrificial layer. Subsequently, we have conducted single-chemical toxicity and multiple choice chemical preference assays on adult Drosophila melanogaster using zinc and acetic acid at various concentrations. Our device has enabled us to 1) demonstrate that Drosophila is capable of sensing the concentration of different chemicals on a PDMS-agar microfluidic device, which plays significant roles in determining oviposition site selection and 2) investigate whether oviposition preference differs between single- and multi-concentration chemical environments. This device may be used to study fundamental and applied biological questions in Drosophila and other egg laying insects. It can also be extended in design to develop sophisticated and dynamic chemical dosing and high-throughput screening platforms in the future that are not easily achievable with the existing oviposition screening techniques.

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Global Medical Discovery features paper: Prof. Larry F. Lemanski

About The Author

Larry F. Lemanski, Ph.D.

Larry F. Lemanski completed his B.S. degree with honors, in Biology and Chemistry, from the University of Wisconsin-Platteville and his M.S. and Ph.D. degrees from Arizona State University, Tempe, Arizona, U.S.A.  After four years as an NIH and MDAA Postdoctoral fellow at the University of Pennsylvania, Philadelphia, he joined the medical faculty at the University of California, San Francisco, as an Assistant Professor in residence and then moved to the faculty of the College of Medicine at the University of Wisconsin, Madison, where he went up through the ranks to Full Professor of Anatomy. He then joined the Upstate Medical University in Syracuse, New York, as Professor and Chairman of the Department of Anatomy and Cell Biology. He moved to Texas A&M University as an Associate Vice President for Research, then to Florida Atlantic University as a Vice President for Research, to Temple University as Senior Vice president for Research and Strategic Initiatives, and to Texas A&M University-Commerce as Provost of the University. He has now transitioned to the position of Distinguished Research Professor at Texas A&M University-Commerce. His research interests throughout his career have involved embryonic heart development and cardiac cell differentiation using a variety of morphological, cellular, biochemical, and molecular biology approaches. He and his associates have published numerous papers in the field of embryonic heart development and cardiac cell differentiation. His current work centers around his earlier pioneering discovery that selected RNAs can promote the differentiation of non-muscle cells to form into functional cardiac tissue.

Global Medical Discovery featured article: A fetal human heart cardiac inducing RNA (CIR) promotes the differentiation of stem cells into cardiomyocytes 

 

Global Medical Discovery features paper: Professor Michael Petrides

About The Author

Michael Petrides is a James McGill Professor at the Montreal Neurological Institute, Department of Neurology and Neurosurgery and the Department of Psychology at McGill University. He obtained a B.Sc. in Experimental Psychology and a M.Sc. in Neurological Science from the University of London and then a Ph.D. in Behavioural Neuroscience from the University of Cambridge.  He subsequently worked as a post-doctoral research fellow at the Montreal Neurological Institute and as a research fellow at Harvard Medical School. The major aspect of Dr. Petrides’ research work is concerned with understanding the functional and anatomical organization of the primate frontal cortex. He has pursued this work in studies with patients who had excisions from the frontal cortex for the treatment of epilepsy, in studies on monkeys with selective lesions in particular parts of the frontal cortex, and in functional neuroimaging studies in healthy human participants. Based on this work he has proposed an influential theoretical framework to understand the functional organization of the lateral prefrontal cortex. Another aspect of his work has been the comparative cytoarchitectonic analysis of the human and the monkey prefrontal cortex that allows integration of research on nonhuman primates with research on the human brain.

Global Medical Discovery featured article: A unilateral medial frontal cortical lesion impairs trial and error learning without visual control  

 

Global Medical Discovery features paper: Dr. Zhang-Qi Feng

About The Author

Zhang-Qi Feng completed a visiting scholarship at The University of Michigan in Ann Arbor as an exchange student (2008–2010), and then earned his Ph.D. (2010) degree in Biomedical Engineering from Southeast University. In fall 2010, he moved to Sun Yat-Sen University as a Lecturer supported by the “100 Talents Program” in the Department of Biomedical Engineering. Since spring 2014, he held an academic position in the School of Chemical Engineering of Nanjing University of Science & Technology. Feng developed several new micro/nano fibrous scaffolds by electrospinning, and has pioneered the application of electrospun fibers to bioartificial liver. His current research interests include the development of bio-inspired materials to improve tissue regeneration and works on advancing understanding the fundamental interaction between biomaterials and biological systems.

Global Medical Discovery featured article: Soft Graphene Nanofibers Designed for the Acceleration of Nerve Growth and Development  

 

 

Global Medical Discovery features paper: Prof. Isabel Haro

About The Author

Prof. Isabel Haro. Senior Staff. B.Sc. Chemistry, University of Barcelona, 1982. M.Sc. Biochemistry,University of Barcelona, 1984. Ph.D. Chemistry, University of Barcelona, 1988. Postdoctoral fellow (1989-1990) between CSIC in Barcelona and Royal Free Hospital in London (Prof. G. Gregoriadis). Research Scientist at CSIC leading the Unit of Synthesis and Biomedical Applications of CSIC in 1990. Since then she has been working in the use of synthetic peptides in the field of biomedicine, specifically in the development of new biosensors for the diagnosis of human illnesses and in the selection of new therapeutic agents of peptide origin through biophysical testing. She has published more than 180 articles, 8 reviews, 30 chapters of books and 8 patents. Also, she has been the principal researcher of 15 research projects and 3 contracts with the industry and supervised 12 doctoral theses. e-mail contact: isabel.haro@iqac.csic.es

Global Medical Discovery featured article: Definition of an 18-mer Synthetic Peptide Derived from the GB virus C E1 Protein as a New HIV-1 Entry Inhibitor  

 

Global Medical Discovery features paper: Professor Bin Li

About The Author

Professor Bin Li is the director of the Biomaterials and Cell Mechanics Laboratory (BCML) of Orthopedic Institute at Soochow University, Suzhou, China. He received the bachelor degree in 1996 and PhD degree in Materials Science from Tsinghua University in 2001. He then joined the Institute of Materials Research and Engineering, Singapore as a Research Associate until 2004. After that he consecutively pursued research training at Carnegie Mellon University, University of Pittsburgh, and Harvard University until 2009, when he took the current position as a full professor at Soochow University. He is the recipient of the Orthopaedics Research Award (1st prize) from Chinese Orthopaedic Association, Xu Guangqi Program from the French Embassy in China, and France Talent Innovation from the Consulate General of France in Shanghai. He currently serves as the chair of China Development Committee of International Chinese Musculoskeletal Research Society (ICMRS). He is a fellow of Chinese Orthopaedic Research Society (CORS), Chinese Association of Orthopaedic Surgeons (CAOS), Chinese Association of Rehabilitation Medicine (CARM), and International Society of Orthopaedic Surgery and Traumatology (SICOT). He has delivered about 40 invited talks and is the author of over 70 publications and 9 book chapters. He now leads a multidisciplinary research group studying biomaterials for bone and cartilage repair, stem cells and tissue engineering, smart molecular recognition and controlled release, surface modification and functionalization, and cellular biomechanics and mechanobiology.

Global Medical Discovery featured article: Modulation of the gene expression of annulus fibrosus-derived stem cells using poly(ether carbonateurethane)urea scaffolds of tunable elasticity 

 

Global Medical Discovery features paper: Prof. Yuemao Shen

About The Author

Dr. Yuemao Shen received his B. Sc. degree in Chemistry from Anhui Normal University in 1986, M.Sc. in natural products chemistry from Kunming Institute of Botany (KIB) of Chinese Academy of Sciences in 1989. He went to Floss Lab at the University of Washington (UW) as a visiting Scientist and became a joint Ph. D. student of KIB and UW in 1995, and received his Ph. D. degree in Botany from KIB of Chinese Academy of Sciences in 1999. Before joining the faculty of Shandong University in 2010, he was an intern Researcher (1989-1991), assistant Researcher (1991-1995), associate Researcher (1998-1999) and Researcher (1999-2004) in KIB, and Professor in Xiamen University (2004-2010). Being a professor of Shandong University, Dr. Shen’s research interests focus on isolation, structure elucidation, and biosynthesis of natural products with anti-infective or antitumor activities.

Global Medical Discovery featured article: Design and synthesis of 2-phenylnaphthalenoids and 2-phenylbenzofuranoids as DNA topoisomerase inhibitors and antitumor agents  

 

Global Medical Discovery features paper: Dr. Philippe Vandekerckhove

About The Author

Philippe Vandekerckhove, M.D./PhD, pathologist, is the CEO of the Belgian Red Cross-Flanders.

Prior to this position Philippe worked as Clinical Director of the University Hospital Leuven from where he also obtained his M.D./PhD and Pathology degree. His clinical and pathology training was further carried out in South Africa (Baragwanath – University of Johannesburg, and Groote Schuur Hospital – University of Cape Town), the US (Woods Hole Marine Biology Laboratory, University of Hawaii, New York University), and The Netherlands (Erasmus University, Rotterdam).

In addition, Philippe studied healthcare management at INSEAD (France) and general management at Harvard Business School. He has published about 60 articles in peer reviewed journals, and 5 chapters in textbooks, mainly in the field of immunology, hematology, blood banking and evidence-based medicine.

Philippe is associate professor at the Faculties of Medicine of the University of Leuven and the University of Ghen. He holds non-executive positions as president of the European Blood Alliance, president of GAP, member of the governing board of the International Federation of Red Cross and Red Crescent Societies, and of the investment committee of Flanders’ Care Invest (Flemish government). In his spare moments, he enjoys jogging, natural horsemanship and time and travel spent in natural surroundings.

Global Medical Discovery featured article: Methodologic quality assessment of red blood cell transfusion guidelines and the evidence base of more restrictive transfusion thresholds 

 

Global Medical Discovery features paper: Dr. Peter Nemes

About The Author

Peter Nemes holds a PhD in Chemistry from the George Washington University (Washington, DC), where he developed laser ablation electrospray ionization mass spectrometry for in situ and in vivo analysis as well as molecular imaging in two and three dimensions as a PhD graduate student (advisor: Prof. Akos Vertes). He completed postdoctoral training in analytical neuroscience at the University of Illinois—Urbana-Champaign (mentor: Prof. Jonathan V. Sweedler), where he developed mass spectrometry technologies to measure small and large molecules in single neurons and to image their spatial distribution. One of these technologies was single-cell capillary electrophoresis, which revealed metabolomic heterogeneity between different neuron types in the central nervous system of Aplysia californica and adoptability of the single-neuronal metabolome to external conditions. Another technology was a custom-built MALDI-C60-SIMS dual ion source mass spectrometer that helped probe the spatial distribution of small-to-large molecules in single neurons. In 2011, Dr. Nemes joined the Food and Drug Administration (FDA, Silver Spring, MD) as a Principal Investigator, where he developed mass spectrometry-based technologies to enable the high-throughput screening of chemical contaminants in regulated drug products and medical devices. There, he developed a mass spectrometry facility and served as the Laboratory Leader of the Laboratory of Chemical Contamination at the Division of Chemistry and Materials Science. In 2013, Dr. Nemes became an Assistant Professor at the Department of Chemistry of the George Washington University. His research develops high-sensitivity mass spectrometry platforms to assess the spatiotemporal evolution of metabolic and proteomic processes. Current work in the Nemes laboratory elucidates molecular mechanisms by which (i) cells acquire different fates in the developing vertebrate embryo and the central nervous system and (ii) respond to external stimuli such as drugs of treatment and toxins. Prof. Nemes has authored 30 peer-reviewed publications, 6 book chapters, and 80+ presentations, and holds 4 licensed patents.  He received the 2008 International Research Fellowship award by the Dimitris N. Chorafas Foundation (Luzern, Switzerland), the 2009 American Institute of Chemists prize in Chemistry by the American Institute of Chemists (Washington, DC), the 2010 Science and Technology Innovation Award by Baxter Healthcare Corporation (Chicago, IL), the 2011 Special recognition by the FDA (Silver Spring, MD), and the 2016 Arthur Findeis Award for Achievements by a Young Analytical Scientist by the American Chemistry Society. Prof. Nemes is a Beckman Young Investigator by the Arnold and Mabel Beckman Foundation.

Global Medical Discovery featured article: Single-Cell Mass Spectrometry for Discovery Proteomics: Quantifying Translational Cell Heterogeneity in the 16-Cell Frog (Xenopus) Embryo

 

 

 

Global Medical Discovery features paper: Dr. Annik Prat

About The Author

Dr. Annik Prat received her PhD in molecular biology in 1988 from the University Pierre et Marie Curie in Paris, France. After 3 years at the Biozentrum in Basel, Switzerland, as a post-doctoral fellow, she became Associate Professor in Molecular Biology at the University Pierre et Marie Curie. Since 1997, she is a staff scientist at the Clinical Research Institute of Montreal (IRCM) and works in Nabil G. Seidah’s laboratory, in which PCSK9 was discovered.

Global Medical Discovery featured article: PCSK9 deficiency unmasks a sex- and tissue-specific subcellular distribution of the LDL and VLDL receptors in mice 

 

Global Medical Discovery features paper: Professor Simon Labbé

About The Author

Dr. Simon Labbé is a Professor of Biochemistry in the Faculty of Medicine and Health Sciences at the Université de Sherbrooke in Québec, Canada.  He received his bachelor’s degree in Microbiology from the Université Laval (Québec) in 1987.  He undertook graduate studies at Laval Université and received his Master (1989) and Ph.D. (1995) in Microbiology and Molecular-cellular biology, respectively.  Dr. Labbé continued his training as a post-doctoral fellow with Dr. Dennis J. Thiele at the Department of Biological Chemistry at the University of Michigan in Ann Arbor, MI, USA.  He was supported by Fellowship awards, including the prestigious Centennial Fellowship from the Medical Research Council of Canada.  Over the past sixteen years he has been at the Université de Sherbrooke where he has established his own laboratory.  As an independent investigator, he has received the New Investigator Award from the Canadian Institutes of Health Research, the Junior II and Senior Investigator Awards from the Fonds de la Recherche en Santé du Québec.  His research group has developed a productive yeast model (Schizosaccharomyces pombe) for investigating copper and iron metabolism at the molecular level.  Because S. pombe provides a genetically tractable model that permits the drawing of parallels with other eukaryotic living systems, especially filamentous yeasts, Dr. Labbé’s research has contributed to the identification of molecular mechanisms that regulate copper and iron transport, as well as uncovering different strategies that yeasts have acquired to take up copper and iron from their environment and/or hosts.

Global Medical Discovery featured article: An antisense RNA-mediated mechanism eliminates a meiosis-specific copper -regulated transcript in mitotic cells 

 

Global Medical Discovery features paper: Professor Randy Mrsny

About The Author

Randy Mrsny currently holds a Professor’s chair of Epithelial Cell Biology at the University of Bath in the Department of Pharmacy and Pharmacology where he studies biological principles associated with normal epithelia cell function and how these are affected in disease states. His work in drug delivery is internationally recognized as evidenced by his election as president of the Controlled Release Society and to co-organize a Gordon Conference on Drug Delivery.

Global Medical Discovery featured article: Enhanced paracellular transport of insulin can be achieved via transient induction of myosin light chain phosphorylation 

 

 

Global Medical Discovery features paper: Prof. Yoshifumi Nishimura

About The Author

Prof. Yoshifumi Nishimura received his Ph. D degree in 1976 from Faculty of Pharmaceutical Sciences of the University of Tokyo on UV resonance Raman spectroscopy of biological molecules, and then worked as an instructor and Associate Professor in the Faculty. In 1989, he moved into Graduate School of Yokohama City University as a Professor and worked on NMR spectroscopy of several transcription factors. Professor Nishimura has been working on structural epi-genomics by NMR, and now is an Adviser to the President of Yokohama City University and also a Project Leader of NMR Platform, which contains 950 MHz, 800 MHz, 700 MHz, 600 MHz, and 500 MHz NMR spectrometers, in the Graduate School of Medical Life Science of Yokohama City University.

Global Medical Discovery featured article: Structural Insight into the Mechanism of TFIIH Recognition by the Acidic String of the Nucleotide Excision Repair Factor XPC  

 

 

Global Medical Discovery features paper: Prof. Markus Raderer, M.D.

About The Author

Prof. Markus Raderer, M.D.

Medical University of Vienna, Vienna, Austria

Markus Raderer undertook his early medical studies at the Medical University of Vienna, completing his residency in internal medicine between 1993 and 1999, specialising in haematology and oncology in 2001. He received the venia docendi for ‘Applied and Experimental Oncology’ and ‘Internal Medicine’ in 1999 and 2002, respectively.  Professor Raderer is currently the Programme Director for Extranodal Lymphomas and for Endocrine Tumours at the Medical University of Vienna. He has been responsible for the management and conduct of phase II and III clinical trials at his institution since 1992.

Professor Raderer is on the Editorial Board of a number of journals including the Journal of Clinical Oncology, World Journal of Gastroenterology, and Middle European Journal of Medical Oncology. He has participated on consensus panels for the European Gastrointestinal Lymphoma Study Group (EGILS) on the topic of B-cell lymphoma of mucosa-associated lymphoid tissue, and the European Society of Medical Oncology (ESMO) on the subject of the management of lymphoid malignancies.

For a list of publications see http://ift.tt/1Pbi5V2

Global Medical Discovery featured article: Long-term safety and activity of cladribine in patients with extranodal B-cell marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma 

 

Global Medical Discovery features paper: Professor Kevin Coombs

About The Author

Dr. Kevin Coombs received his B.A.s in Biology and English from the State University of New York in Geneseo, N.Y., and his M.A. and Ph.D degrees from the University of Texas in Austin, TX. His post-doctoral training in molecular and structural virology was done in the labs of Dr. Bernard Fields at Harvard Medical School and Dr. Steven Harrison at Harvard University. Dr. Coombs is presently a Professor in the Department of Medical Microbiology and is Assistant Dean of Research for the College of Medicine in the Faculty of Health Sciences. He serves on several Editorial Boards of journals publishing in Cell Biology, Molecular Biology and Virology, has served as a panel member on NIH and AHFMR Peer Review Committees and as Scientific Officer and panel member on the CIHR Virology and Viral Pathogenesis Committee. His research interests include delineation of the protein and nucleic acid interactions in nucleoprotein complexes, using a variety of RNA viruses as models. This work is in general areas of:

* Generation and molecular characterization of assembly-defective virus mutants

* Inhibition of virus replication using pharmacologic inhibitors

* Mass spectrometry- and Systems-based analyses of virus and host protein alterations

* Development of non-pathogenic viruses as “bio-indicators” for wastewater and medical instrument disinfection.

Global Medical Discovery featured article: Differential Reovirus-Specific and Herpesvirus-Specific Activator Protein 1 Activation of Secretogranin II Leads to Altered Virus Secretion

 

Global Medical Discovery features paper: Dr. Qitao Ran

About The Author

Dr. Qitao Ran is an Associate Professor at Department of Cellular & Structural Biology of the University of Texas Health Science Center at San Antonio. Dr. Ran received his PhD degree from Peking Union Medical College (Beijing, China) in 1995. He conducted postdoctoral research at Baylor College of Medicine (Houston, Texas) from 1995 to 2000, and continued his research at the University of Texas Health Science Center at San Antonio afterwards. Dr. Ran was appointed Assistant Professor at Department of Cellular & Structural Biology and Barshop Institute for Longevity and Aging Research of the University of Texas Health Science Center at San Antonio in 2006. Dr. Ran was also appointed Research Health Scientist at South Texas Veterans Health Care System in 2007. The main research interest of Dr. Ran’s lab is to interrogate the mechanisms of neurodegenerative diseases such as Alzheimer’s disease and ALS as well as aging.

Global Medical Discovery featured article: Ablation of the Ferroptosis Inhibitor Glutathione Peroxidase 4 in Neurons Results in Rapid Motor Neuron Degeneration and Paralysis 

 

Global Medical Discovery features paper: Professor Hong Chen

About The Author

Hong Chen is a professor at the College of Chemistry, Chemical Engineering and Materials Science at Soochow University, Suzhou, China. She earned her Ph.D. degree from Nanjing University in 2001 and worked as a postdoctral fellow at McMaster University (2001-2004). After returning back to China, she held a full professor position at Wuhan University of Technology from 2004 to 2009. In 2010, her research group moved to Soochow University, where she established Macromolecules and Biointerface Laboratory (MacBio) of Soochow University. She has been the PI of more than 10 national research projects funded by the Ministry of Science and Technology of China, the Ministry of Education of China and the National Natural Science Foundation of China, including a Major International Joint Research Project. She is the winner of National Science Fund for Distinguished Young Scholars (2011). She has been admitted as a Fellow of the Royal Society of Chemistry (FRSC) in 2014. She was a guest editor for the special issue: “Biointerfaces in China” published in 2011 and became an editor of Colloids and Surface B: Biointerfaces since 2013, after three years she became the associate editor of Polymer Chemistry. Her research interests include: surface modification and functionalization of biomaterials, interaction of protein/cell and biomaterials, hemocompatibility of biomaterials, and biological detection. She has published more than 100 research articles in various peer reviewed journals. For more detailed information, please refer to her website: macbio.suda.edu.cn.

Global Medical Discovery featured article: A Smart Antibacterial Surface for the On-Demand Killing and Releasing of Bacteria

Global Medical Discovery features paper: Dr. Maxim V. Berezovski

About The Author

Dr. Maxim V. Berezovski is an Associate Professor of Chemistry at the University of Ottawa in Canada and a Director of Imaging and Proteomics core facilities. He won a 2015 University of Ottawa’s Young Researcher Award and was the recipient of an Early Research Award from Ministry of Research and Innovation in 2012. His research focuses on the study of affinity interactions and conformational dynamics of biomolecules by kinetic capillary electrophoresis and mass spectrometry and on the development of DNA aptamers for sensing pathogens and cancer cells.

Global Medical Discovery featured article: Direct detection of endogenous MicroRNAs and their post-transcriptional modifications in cancer serum by capillary electrophoresis-mass spectrometry

Global Medical Discovery features paper: Direct detection of endogenous MicroRNAs and their post-transcriptional modifications in cancer serum by capillary electrophoresis-mass spectrometry

Significance Statement

MicroRNAs (miRNAs) are a class of small, single-stranded, non-protein coding RNA molecules that regulate cellular messenger RNA and protein levels by binding to specific messenger RNAs. MicroRNAs play a crucial role in almost every aspect of cell biology, including developmental timing, proliferation, and apoptosis. Moreover, microRNAs  are involved in various cellular activities, such as insulin secretion, immune response, neurotransmitter synthesis, and viral replication. Thus, aberrant microRNA expression has an impact on those critical processes, and consequently, leads to a number of pathological and malignant conditions.

It was observed that selective groups of miRNAs are commonly down-regulated or up-regulated in different types of human cancers and were frequently associated with cytogenetic abnormalities. For example consistent up-regulation of miR-17 and miR-21 was observed in prostate, colon, stomach, lung and pancreatic tumors and miR-155 was identified to be up-regulated in lung, breast and colon cancer. On the contrary, it was reported that miR-29 was down-regulated in chronic lymphocytic leukemia (CLL), acute myeloid leukemia, mantle cell lymphoma, breast, lung and liver cancer. Additionally miR-15a and miR16-1-3p was identified to be down-regulated in CLL, prostate and pituitary adenomas and let-7 family members were found to be down-regulated in breast, lung, colon, ovarian and stomach cancer.

According to the latest miRBase release (www.mirbase.org), more than 30,000 mature microRNA sequences are listed, with ~2500 human microRNAs identified up to date, which can target more than 30% of the human genome. Given the role miRNA plays in human diseases, recent studies have shown that microRNA expression profiles can serve for diagnostic tests on a molecular level for diseases, as well as bases for novel therapeutics. Most importantly, recent identification of circulating microRNAs, have shown great potential of their use as biomarkers since they are readily available in blood samples. MicroRNA analysis, however, presents many challenges due to their low abundance, small size and sequence similarity between miRNA family members. Their small size makes their analysis more difficult compared to messenger RNAs, particularly with conventional molecular biology methods, such as polymerase chain reaction (PCR) and hybridization-based assays. The small size of probes that are used greatly affects the efficiency of these methods because of a very low melting temperature.

Since the development of massively parallel/next-generation sequencing (NGS) of nucleic acids, there has been an increase of microRNA identification and discovery. NGS involves preparation of a complemented DNA library from the RNA sample, followed by the sequencing of millions of individual molecules. Obtained sequence reads undergo a bioinformatical analysis to identify and quantify (relative abundance) both known and novel microRNAs using application tools such as miRDeep. Although NGS is a high-throughput assay for miRNA expression profiling, disadvantages of this technique includes the high cost, the high amount of RNA used, and the sequence-specific biases due to enzymatic steps in complemented DNA library preparation. Nonetheless, NGS has been recently used for differential expression analysis of miRNAs in different diseases, including ovarian cancer and Huntington’s disease, suggesting the usefulness of this technique for diagnostics and early detection.

It has been reported that microRNAs are found in body fluids, such as blood, saliva and urine, of both diseased and healthy people. These extracellular circulating microRNAs exist in a stable form and are resistant to endogenous RNAse activity, as well as extreme pHs and temperatures. The stability of circulating microRNAs are proven to be due to the fact that they are found to be packaged in the micro vesicles, such as micro particles and exosomes, or associated with RNA binding proteins, including Argonaute 2 (AGO2) and nucleophosmin (NPM1). Aberrant expression of circulating miRNAs in different diseases, such as stroke, cardiovascular diseases, breast cancer, ovarian cancer, gastric cancer, lung cancer, colorectal cancer, diabetes, hepatocellular carcinoma and drug induced liver injury has been reported. Blood-based biomarkers are attractive for cancer screening due to their minimal invasiveness, relatively low cost and ease of reproducibility.

MicroRNAs are also modified through a series of processing events after transcription like 5´-end phosphorylation, 3´- end adenylation or uridylation, terminal nucleotide deletion. The problem is that existing bioanalytical methods such as microarrays and a quantitative polymerase chain reaction are sensitive, but not capable of identifying the posttranscriptional modifications of microRNA. Thus, there is a need for a miRNA detection technique, which is direct and multiplexed, requiring minimal sample preparation and can provide qualitative information regarding these modifications.

In this publication, the research laboratory lead by Professor Maxim Berezovski at University of Ottawa reported a multiplexed microRNA detection technique based on capillary electrophoresis – electrospray ionization – mass spectrometry (CE-ESI-MS) that offers a convenient platform for label-free, direct analysis of miRNA from biological samples. CE is highly efficient, and versatile, CE separations are fast, relatively inexpensive, and robust, requiring small amounts of sample and reagents. Coupling CE with MS makes it a powerful method for analysis of biomolecules as it combines high-resolution separations with high detection selectivity and sensitivity. Electrospray ionization is a soft ionization technique used in mass spectrometry for biomolecules. miRNAs can be directly observed without any amplification by mass spectrometry. On-line sample pre-concentration with desalting prior to CE-ESI-MS improves concentration sensitivity for detection of very low amounts of miRNA in complex biological samples without ionization suppression. Due to the size of mature miRNA molecules (21-23 nucleotides), the effect of nucleotide chain fragmentation can potentially be minimized. Therefore, CE-ESI-MS represents a promising method for endogenous miRNA expression and sequence analyses. The results for the CE-MS study were validated by conventional SYBR green-based quantitative reverse transcription PCR.

Using the CE-MS method, the researchers detected two endogenous human circulating microRNAs, a 23-nucleotide long 5´-phosporylated microRNA with 3´-uridylation (iso-miR-16-5p) and a 22-nucleotide long 5´-phosporylated microRNA (miR-21-5p) isolated from B-cell chronic lymphocytic leukemia serum. The CE separation and following MS analysis provides label-free quantitation and reveals modifications of microRNAs.  MicroRNA profiling of serum samples with CE-MS has the potential to be a versatile and minimally invasive bioassay that could lead to better clinical diagnostics and disease treatment.

 

About The Author

Dr. Nasrin Khan is an NSERC Visiting Research Fellow in the department of Environmental Health Science and Research Bureau, Health Canada. Her current research is focused on the study of gene expression and epigenetics (DNA methylation, histone modifications, and microRNA expression) in mammals upon exposure to environmental chemicals. 

About The Author

Dr. Gleb Mironov is a mass spectrometrist at the University of Ottawa. His major research interests lie in the area of mass spectrometry assisted biomarker discovery and characterization.  

About The Author

Dr. Maxim V. Berezovski is an Associate Professor of Chemistry at the University of Ottawa in Canada and a Director of Imaging and Proteomics core facilities. He won a 2015 University of Ottawa’s Young Researcher Award and was the recipient of an Early Research Award from Ministry of Research and Innovation in 2012. His research focuses on the study of affinity interactions and conformational dynamics of biomolecules by kinetic capillary electrophoresis and mass spectrometry and on the development of DNA aptamers for sensing pathogens and cancer cells.  

Journal Reference

Anal Bioanal Chem. 2016 Apr;408(11):2891-9. 

Khan N¹, Mironov G¹, Berezovski MV².

Show Affiliations

1. Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6 N5, Canada.
2. Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6 N5, Canada. Maxim.Berezovski@uOttawa.ca.

 

Abstract

MicroRNA molecules (miRNAs) are a class of small, single-stranded, non-coding RNA molecules that regulate cellular messenger RNA and their corresponding proteins. Extracellular miRNAs circulate in the bloodstream inside exosomes or in complexes with proteins and lipoproteins. The miRNA sequences and their quantitative levels are used as unique signatures associated with cancer diagnosis and prognosis after anticancer treatment. MicroRNAs are modified through a series of processing events after transcription like 5′-end phosphorylation, 3′- end adenylation or uridylation, terminal nucleotide deletion. The problem is that existing bioanalytical methods such as microarrays and a quantitative polymerase chain reaction are sensitive, but not capable of identifying the post-transcriptional modifications of miRNA. Here we report a capillary electrophoresis-mass spectrometry (CE-MS) method, which performs a multiplex, direct analysis of miRNAs from biological samples. Using the CE-MS method, we detected two endogenous human circulating miRNAs, a 23-nucleotide long 5′-phosporylated miRNA with 3′-uridylation (iso-miR-16-5p), and a 22-nucleotide long 5′-phosporylated miRNA (miR-21-5p) isolated from B-cell chronic lymphocytic leukemia serum. The CE separation and following MS analysis provides label-free quantitation and reveals modifications of miRNAs. MicroRNA profiling of serum samples with CE-MS has the potential to be a versatile and minimally invasive bioassay that could lead to better clinical diagnostics and disease treatment.

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Global Medical Discovery features paper: Biomarkers of liver fibrosis detecting with electrochemical immunosensor on clinical serum

Significance Statement

Chronic hepatic disease causes high morbidity and mortality worldwide, which can lead to liver fibrosis and the subsequent development of cirrhosis and even hepatocellular carcinoma. For chronic liver injuries of many etiologies, including viral hepatitis, alcohol abuse, metabolic diseases, autoimmune diseases, and cholestatic liver diseases, they could produce fibrosis as a result of deregulation of the normal healing process with massive accumulation of extracellular matrix (ECM). Therefore, the early diagnosis of liver fibrosis is vital for therapeutic decisions and prognostic evaluations. Among the various diagnostic approaches, needle biopsy is considered as the ‘gold standard’. However, it was invasive, confounded by high sampling heterogeneity and carried a finite risk of complications. Especially, it is not suit for frequent evaluations of this chronic disease.

In the research, an electrochemical immunosensor was established to detect representative biomarkers of liver fibrosis, such as hyaluronate acid (HA) and transforming growth factor beta 1 (TGF1). Through a self-assembled monolayer of polyethylene glycol (PEG), anti-bodies against HA and TGF1 were successfully immobilized on interdigitated electrodes. It produced a robust and sensitive membrane by improving the uniformity, density, and distribution of the antibodies for the biomarkers. Based on impedance sensing, HA and TGF1 were sensitively detected in the ranges of 1-1000 ng/ml. The detection limits of HA and TGF1 reached 0.586 ng/ml and 0.570 ng/ml, respectively. In addition, for the detection of clinical serum samples, the results were in excellent agreement with the tests of HA, type III pre-collagen (PCIII), IV collagen (IV-C), and laminin (LN) that conducted by radio immunoassay for liver fibrosis. It indicated that the approach provided a valuable, universal, and label-free strategy in evaluating liver fibrosis and other chronic diseases for point-of-care diagnostics. Compared to the common immunoassays, electrochemical sensing had attracted more interests due to their inherent advantages, including high sensitivity, time-saving, and eases of operating. It exhibited great potential in point-of-care diagnostics for early detection of various diseases. Through sensitively detecting the serum biomarkers, the electrochemical immunosensor may be useful in detecting the presence of or severe, and probably moderate, fibrosis. The precise diagnostic for a disease is essential for successful treatment and recovery of patients. Therefore, the combination of different biomarkers, serum levels of HA, TGF-β1, would aid clinicians in diagnosing fibrosis during the early stages, eliminating the need for liver biopsy and allowing early treatment, thereby preventing fibrosis progression.

Figure Legend: A label-free immunosensor in detecting representative biomarkers of liver fibrosis, hyaluronate acid (HA) and transforming growth factor beta 1 (TGF1) through electrochemical impedance.

About The Author

Qingjun Liu received his Ph.D. degree in biomedical engineering from Zhejiang University, PR China in 2006. He is currently a professor in Biosensor National Special Lab, Zhejiang University. He is also a visiting scholar in the Micro and Nanotechnology Laboratory (MNTL) at the University of Illinois at Urbana-Champaign (UIUC). He received Nomination Award of the Excellent PhD Dissertation of China, in 2008. He published the book of Cell-Based Biosensors: Principles and Applications, by Artech House Publishers USA in October 2009. And, the book of Biomedical Sensors and Measurement published by Zhejiang University Press and Springer-Verlag GmbH Berlin Heidelberg, 2011. His research interests concentrate on the biosensors (e.g. living cell sensor, DNA sensor and protein sensor) and BioMEMS system. 

Journal Reference

Sensors and Actuators B: Chemical, Volume 222, 2016, Pages 127–132.

Yao Yao¹, Jianfeng Bao², Yanli Lu¹,Diming Zhang¹,Senbiao Luo³,Xing Cheng¹,Qian Zhang¹, Shuang i¹,Qingjun Liu¹

Show Affiliations

1. Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, PR China
2. Xixi Hospital of Hangzhou, Hangzhou 310023, PR China
3. Shangyu People’s Hospital of Zhejiang Province, Shangyu 312000, PR China

Abstract

Diagnosing hepatic fibrosis at an early stage with sensitive and specific monitoring approach is crucial for patient therapeutics and survival. In this study, an electrochemical immunosensor was established to detect representative biomarkers of liver fibrosis, such as hyaluronate acid (HA) and transforming growth factor beta 1 (TGFβ1). Through a self-assembled monolayer of polyethylene glycol (PEG), antibodies against HA and TGFβ1 were successfully immobilized on interdigitated electrodes. It produced a robust and sensitive membrane by improving the uniformity, density, and distribution of the antibodies for the biomarkers. Based on impedance sensing, HA and TGFβ1 were sensitively detected in the ranges of 1–1000 ng/ml. The detection limits of HA and TGFβ1 reached 0.586 ng/ml and 0.570 ng/ml, respectively. In addition, for the detection of clinical serum samples, the results were in excellent agreement with the tests of HA, type III pre-collagen (PCIII), IV collagen (IV-C), and laminin (LN) that conducted by radioimmunoassay for liver fibrosis. The research indicated that the approach provided a valuable, universal, and label-free strategy in evaluating liver fibrosis and other chronic diseases for point-of-care diagnostics.

Go To Sensors and Actuators B: Chemical

 

Global Medical Discovery features paper: Synergism of Water Shock and a Biocompatible Block Copolymer Potentiates the Antibacterial Activity of Graphene Oxide

Significance Statement

There is an urgent need to find alternative routes to control the spreading of antibiotics-resistant bacteria. Graphene and its water-soluble form graphene oxide (GO) were previously shown to be promising antibacterial agents. However, their antibacterial activity was relatively low and they show toxicity to human cells at high dose of usage. This study demonstrated a new strategy for significantly enhancing the antibacterial activity of graphene oxide. It showed that graphene oxide can kill 99% of bacteria when mixed with a human-friendly detergent in salt-reduced water. Further, the mixture of graphene oxide and Pluronic displays over 50% lower toxicity to human skin cells than the effect of graphene oxide alone. The developed strategy relies on the combination of two effects. The first effect is coming from the water itself. Bacteria inevitably undergo swelling when faced with salt-reduced water which puts a stress on bacterial envelope due to occurrence of microscopic damages. The second effect comes from pluronic; a bio-friendly polymer widely used in drug formulations and food applications. Pluronic increases the stability of graphene oxide in solution and also helps graphene oxide to interact with bacteria better by surrounding the bacterial cells more effectively. Water and detergents are undoubtedly the most common cleaning agents. This study may open the door for graphene oxide to be a widespread cleaning agent for fighting bacteria.

 

About The Author

Yuan Chen received his BEng in Chemical Engineering and MEng in Biochemical Engineering from Tsinghua University. He obtained his PhD in Chemical Engineering at Yale University in 2005. He is currently a Professor at School of Chemical and Biomolecular Engineering (CBE), The University of Sydney. He joined the School of Chemical and Biomedical Engineering in Nanyang Technological University (NTU) in Singapore as an Assistant Professor in 2005. He was promoted to a tenured Associate Professor in 2010. He was visiting Associate Professor at Brown University in 2010 and visiting Chair Professor at Tianjin University of Technology in China 2011-2015. He served as Head of CBE Division in NTU from July 2011 to June 2014. He received an Excellence in Review Award from CARBON in 2015, a Young Scientist Award from the Singapore National Academy of Science in 2011, a Tan Chin Tuan Exchange Fellowship in Engineering in 2010, and JSPS exchange award in 2009. He is currently associate editor for Carbon (Elsevier), editorial board member for Nanomaterials, and Heliyon (Elsevier).  His research focuses on developing scalable chemical processes to synthesize carbon nanomaterials with well-defined nanoscale structures, assembling nanoscale carbon nanomaterials into functional macroscale systems, and utilizing these novel materials for sustainable energy, environmental and biomedical applications.

About The Author

Enis Karahan earned BSc double-degree in Chemical Engineering and Molecular Biology & Genetics from İstanbul Technical University. He received his MSc in Materials Science and Engineering at Koç University. Holding Singapore International Graduate Award (SINGA), he currently pursues his PhD studies in Bioengineering at Nanyang Technological University and Singapore Institute of Manufacturing Technologies of A*STAR. In addition to his academic experience, he also has an industrial background majorly gained in an R&D department of a textile company focused on polymer technologies. His expertise covers a broad spectrum of materials science including self-assembly of multilayered surface coatings, noncovalent functionalization of nanoparticles, and antibacterial, biomedical, and environmental applications of carbon-based nanocomposites to name a few. To date, he has over ten publications in peer-reviewed journals on his account. 

 

Journal Reference

Small. 2016 Feb;12(7):951-62.

Karahan HE^1,2, Wei L¹, Goh K¹, Wiraja C¹, Liu Z¹, Xu C^1,3, Jiang R¹, Wei J², Chen Y^1,4.

Show Affiliations

1. School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, 637459, Singapore.
2. Singapore Institute of Manufacturing Technology (SIMTech), Singapore, 638075, Singapore.
3. NTU-Northwestern Institute of Nanomedicine, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
4. School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, 2006, Australia.

 

Abstract

Graphene oxide (GO) is promising in the fight against pathogenic bacteria. However, the antibacterial activity of pristine GO is relatively low and concern over human cytotoxicity further limits its potential. This study demonstrates a general approach to address both issues. The developed approach synergistically combines the water shock treatment (i.e., a sudden decrease in environmental salinity) and the use of a biocompatible block copolymer (Pluronic F-127) as a synergist co-agent. Hypoosmotic stress induced by water shock makes gram-negative pathogens more susceptible to GO. Pluronic forms highly stable nanoassemblies with GO (Pluronic-GO) that can populate around bacterial envelopes favoring the interactions between GO and bacteria. The antibacterial activity of GO at a low concentration (50 μg mL(-1) ) increases from <30% to virtually complete killing (>99%) when complemented with water shock and Pluronic (5 mg mL(-1) ) at ≈2-2.5 h of exposure. Results suggest that the enhanced dispersion of GO and the osmotic pressure generated on bacterial envelopes by polymers together potentiate GO. Pluronic also significantly suppresses the toxicity of GO toward human fibroblast cells. Fundamentally, the results highlight the crucial role of physicochemical milieu in the antibacterial activity of GO. The demonstrated strategy has potentials for daily-life bacterial disinfection applications, as hypotonic Pluronic-GO mixture is both safe and effective.

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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