Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Donald G. Murphy is active.

Publication


Featured researches published by Donald G. Murphy.


Hepatology | 2005

Consensus proposals for a unified system of nomenclature of hepatitis C virus genotypes

Peter Simmonds; Jens Bukh; Christophe Combet; Gilbert Deléage; Nobuyuki Enomoto; Stephen M. Feinstone; Phillippe Halfon; Geneviève Inchauspé; Carla Kuiken; Geert Maertens; Masashi Mizokami; Donald G. Murphy; Hiroaki Okamoto; Jean-Michel Pawlotsky; François Penin; Erwin Sablon; Tadasu Shin-I; Lieven Stuyver; Heinz-Jürgen Thiel; Sergei Viazov; Amy J. Weiner; Anders Widell

International standardization and coordination of the nomenclature of variants of hepatitis C virus (HCV) is increasingly needed as more is discovered about the scale of HCV‐related liver disease and important biological and antigenic differences that exist between variants. A group of scientists expert in the field of HCV genetic variability, and those involved in development of HCV sequence databases, the Hepatitis Virus Database (Japan), euHCVdb (France), and Los Alamos (United States), met to re‐examine the status of HCV genotype nomenclature, resolve conflicting genotype or subtype names among described variants of HCV, and draw up revised criteria for the assignment of new genotypes as they are discovered in the future. A comprehensive listing of all currently classified variants of HCV incorporates a number of agreed genotype and subtype name reassignments to create consistency in nomenclature. The paper also contains consensus proposals for the classification of new variants into genotypes and subtypes, which recognizes and incorporates new knowledge of HCV genetic diversity and epidemiology. A proposal was made that HCV variants be classified into 6 genotypes (representing the 6 genetic groups defined by phylogenetic analysis). Subtype name assignment will be either confirmed or provisional, depending on the availability of complete or partial nucleotide sequence data, or remain unassigned where fewer than 3 examples of a new subtype have been described. In conclusion, these proposals provide the framework by which the HCV databases store and provide access to data on HCV, which will internationally coordinate the assignment of new genotypes and subtypes in the future. (HEPATOLOGY 2005.)


The Journal of Infectious Diseases | 2013

Whole Genome Pyrosequencing of Rare Hepatitis C Virus Genotypes Enhances Subtype Classification and Identification of Naturally Occurring Drug Resistance Variants

Ruchi M. Newman; Thomas Kuntzen; Brian Weiner; Andrew Berical; Patrick Charlebois; Carla Kuiken; Donald G. Murphy; Peter Simmonds; Phil Bennett; Niall J. Lennon; Bruce W. Birren; Michael C. Zody; Todd M. Allen; Matthew R. Henn

BACKGROUND  Infection with hepatitis C virus (HCV) is a burgeoning worldwide public health problem, with 170 million infected individuals and an estimated 20 million deaths in the coming decades. While 6 main genotypes generally distinguish the global geographic diversity of HCV, a multitude of closely related subtypes within these genotypes are poorly defined and may influence clinical outcome and treatment options. Unfortunately, the paucity of genetic data from many of these subtypes makes time-consuming primer walking the limiting step for sequencing understudied subtypes. METHODS  Here we combined long-range polymerase chain reaction amplification with pyrosequencing for a rapid approach to generate the complete viral coding region of 31 samples representing poorly defined HCV subtypes. RESULTS  Phylogenetic classification based on full genome sequences validated previously identified HCV subtypes, identified a recombinant sequence, and identified a new distinct subtype of genotype 4. Unlike conventional sequencing methods, use of deep sequencing also facilitated characterization of minor drug resistance variants within these uncommon or, in some cases, previously uncharacterized HCV subtypes. CONCLUSIONS  These data aid in the classification of uncommon HCV subtypes while also providing a high-resolution view of viral diversity within infected patients, which may be relevant to the development of therapeutic regimens to minimize drug resistance.


Journal of General Virology | 2012

Full-length sequences of 11 hepatitis C virus genotype 2 isolates representing five subtypes and six unclassified lineages with unique geographical distributions and genetic variation patterns.

Chunhua Li; Hong Cao; Ling Lu; Donald G. Murphy

In this study, we characterized full-length hepatitis C virus (HCV) genome sequences for 11 genotype 2 isolates. They were isolated from the sera of 11 patients residing in Canada, of whom four had an African origin. Full-length genomes, each with 18-25 overlapping fragments, were obtained by PCR amplification. Five isolates represent the first complete genomes of subtypes 2d, 2e, 2j, 2m and 2r, while the other six correspond to variants that do not group within any assigned subtypes. These sequences had lengths of 9508-9825 nt and each contained a single ORF encoding 3012-3106 aa. Predicted amino acids were carefully inspected and unique variation patterns were recognized, especially for a 2e isolate, QC64. Phylogenetic analysis of complete genome sequences provides evidence that there are a total of 16 subtypes, of which 11 have been described here. Co-analysis with 68 partial NS5B sequences also differentiated 18 assigned subtypes, 2a-2r, and eight additional lineages within genotype 2, which is consistent with the analysis of complete genome sequences. The data from this study will now allow 10 assigned subtypes and six additional lineages of HCV genotype 2 to have their full-length genomes defined. Further analysis with 2021 genotype 2 sequences available in the HCV database indicated that the geographical distribution of these subtypes is consistent with an African origin, with particular subtypes having spread to Asia and the Americas.


Journal of General Virology | 2013

Full-length genome sequences of five hepatitis C virus isolates representing subtypes 3g, 3h, 3i and 3k, and a unique genotype 3 variant.

Ling Lu; Chunhua Li; Jie Yuan; Teng Lu; Hiroaki Okamoto; Donald G. Murphy

We characterized the full-length genomes of five distinct hepatitis C virus (HCV)-3 isolates. These represent the first complete genomes for subtypes 3g and 3h, the second such genomes for 3k and 3i, and of one novel variant presently not assigned to a subtype. Each genome was determined from 18-25 overlapping fragments. They had lengths of 9579-9660 nt and each contained a single ORF encoding 3020-3025 aa. They were isolated from five patients residing in Canada; four were of Asian origin and one was of Somali origin. Phylogenetic analysis using 64 partial NS5B sequences differentiated 10 assigned subtypes, 3a-3i and 3k, and two additional lineages within genotype 3. From the data of this study, HCV-3 full-length sequences are now available for six of the assigned subtypes and one unassigned. Our findings should add insights to HCV evolutionary studies and clinical applications.


Journal of General Virology | 2014

Full-length genomes of 16 hepatitis C virus genotype 1 isolates representing subtypes 1c, 1d, 1e, 1g, 1h, 1i, 1j and 1k, and two new subtypes 1m and 1n, and four unclassified variants reveal ancestral relationships among subtypes.

Ling Lu; Chunhua Li; Donald G. Murphy

We characterized the full-length genomes of 16 distinct hepatitis C virus genotype 1 (HCV-1) isolates. Among them, four represented the first full-length genomes for subtypes 1d (QC103), 1i (QC181), 1j (QC329) and 1k (QC82), and another four corresponded to subtypes 1c (QC165), 1g (QC78), 1h (QC156) and 1e (QC172). Both QC196 and QC87 were assigned into a new subtype 1m, and QC113 and QC74 into another new subtype 1n. The remaining four (QC60, QC316, QC152 and QC180) did not classify among the established subtypes and corresponded to four new lineages. Subtypes 1j, 1k, 1m, 1n and the unclassified isolate QC60 were identified in Haitian immigrants. In the updated HCV nomenclature of 2005, a total of 12 subtypes of HCV-1 were designated. Including the data from the present study, all but subtype 1f now have their full-length genomes defined. Further analysis of partial NS5B sequences available in GenBank denoted a total of 21 unclassified lineages, indicating the taxonomic complexity of HCV-1. Among them, six have had their full-length genomes characterized. Based on the available full-length genome sequences, a timescale phylogenetic tree was reconstructed which estimated important time points in the evolution of HCV-1. It revealed that subtype 1a diverged from its nearest relatives 135 years ago and subtype 1b diverged from its nearest relatives 112 years ago. When subtypes 1a, 1j, 1k, 1m, 1n and six close relatives (all but one from Haitian immigrants) were considered as a whole, the divergence time was 176 years ago. This diversification was concurrent with the time period when the transatlantic slave trade was active. When taking all the HCV-1 isolates as a single lineage, the divergence time was 326 years ago. This analysis suggested the existence of a recent common ancestor for subtype 1a and the Haitian variants; a co-origin for subtypes 1b, 1i and 1d was also implied.


Journal of General Virology | 2013

Eight novel hepatitis C virus genomes reveal the changing taxonomic structure of genotype 6.

Hongren Wang; Zhiguo Yuan; Eleanor Barnes; Manqiong Yuan; Chunhua Li; Yongshui Fu; Xueshan Xia; Gang Li; Paul N. Newton; Manivanh Vongsouvath; Paul Klenerman; Oliver G. Pybus; Donald G. Murphy; Kenji Abe; Ling Lu

Analysis of partial hepatitis C virus sequences has revealed many novel genotype 6 variants that cannot be unambiguously classified, which obscure the distinctiveness of pre-existing subtypes. To explore this uncertainty, we obtained genomes of 98.0–98.8 % full-length for eight such variants (KM35, QC273, TV257, TV476, TV533, L349, QC271 and DH027) and characterized them using phylogenetic analyses and per cent nucleotide similarities. The former four are closely related phylogenetically to subtype 6k, TV533 and L349 to subtype 6l, QC271 to subtypes 6i and 6j, and DH027 to subtypes 6m and 6n. The former six defined a high-level grouping that comprised subtypes 6k and 6l, plus related strains. The threshold between intra- and inter-subtype diversity in this group was indistinct. We propose that similar results would be seen elsewhere if more intermediate variants like QC271 and DH027 were sampled.


Mechanisms of Ageing and Development | 1975

Nih gerontology research support: Policy evaluation of in vitro cell lineage studies

Donald G. Murphy

Populations of cultured human diploid cells, used extensively in research on aging, are not well understood in terms of kinetics and mitotic activity of constituent cells. NICHD has supported, by contract, cell lineage studies to elucidate such cell characteristics contributing to the cell population degeneration and death. The policy of NICHD (NIA) encouragment of such studies has been evaluated. A need for cell lineage and related data from cultured-cell populations is recognized, and research necessary to achieve these data will be encouraged. Grant applications to this end are sought.


Experimental Aging Research | 1978

National Institute on Aging cell-line repository.

Nirmal K. Das; Donald G. Murphy

The National Institute on Aging (NIA) has established, under contract, a cell-line repository. This resource is designed to support NIA grantees, prospective grantees, and other laboratories engaged in cellular aging research. Services of the NIA Cell-Line Repository include storage and distribution of characterized, contaminant-free normal diploid and genetically-marked human cell-lines.


Diseases of The Colon & Rectum | 1984

The national institutes of health grant mechanisms for anorectal and colonic biomedical research

Donald G. Murphy; Donna J. Dean

Knowledge of the anorectum in health and in disease lags substantially behind that of other regions of the digestive tract. A paucity of fundable grant applications on anorectal research is reflected in a history of the National Institutes of Health (NIH) anorectal research support being disproportionately low. This history is of particular concern recognizing the relative national significance of anorectal diseases and disorders. The National Institute of Arthritis, Diabetes, and Digestive and Kidney Diseases (NIADDK) seeks to broaden research and research training support of: 1) anorectal diseases and disorders, 2) the basic sciences of the anorectum, and 3) the relationship of the anorectum to the more proximal gut. Applications for research and research training grants are encouraged. Potential grant applicants are encouraged to contact NIH staff for information on anorectal programs and on grant application procedures and policies.


Mechanisms of Ageing and Development | 1981

The National Institute on Aging repository cell cultures.

Nirmal K. Das; Donald G. Murphy

Abstract One hundred and ninety-seven cell lines are now available for gerontological and related areas of research from the National Institute on Aging Cell-Line Repository. The Repository primarily supplies fibroblast-like cells of lung and dermal origin. These cell lines are listed in this article.

Collaboration


Dive into the Donald G. Murphy's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ling Lu

University of Kansas

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kenji Abe

National Institutes of Health

View shared research outputs
Top Co-Authors

Avatar

Yongshui Fu

Gulf Coast Regional Blood Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Curt H. Hagedorn

University of Arkansas for Medical Sciences

View shared research outputs
Top Co-Authors

Avatar

Nirmal K. Das

National Institutes of Health

View shared research outputs
Top Co-Authors

Avatar

Teng Lu

University of Southern California

View shared research outputs
Top Co-Authors

Avatar

Xueshan Xia

Kunming University of Science and Technology

View shared research outputs
Researchain Logo
Decentralizing Knowledge