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J Nugent

Publications and source records attributed to J Nugent.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of equid herpesvirus 1 strain variation reveals a point mutation of the DNA polymerase strongly associated with neuropathogenic versus nonneuropathogenic disease outbreaks.

Equid herpesvirus 1 (EHV-1) can cause a wide spectrum of diseases ranging from inapparent respiratory infection to the induction of abortion and, in extreme cases, neurological disease resulting in paralysis and ultimately death. It has been suggested that distinct strains of EHV-1 that differ in pathogenic capacity circulate in the field. In order to investigate this hypothesis, it was necessary to identify genetic markers that allow subgroups of related strains to be identified. We have determined all of the genetic differences between a neuropathogenic strain (Ab4) and a nonneuropathogenic strain (V592) of EHV-1 and developed PCR/sequencing procedures enabling differentiation of EHV-1 strains circulating in the field. The results indicate the occurrence of several major genetic subgroups of EHV-1 among isolates recovered from outbreaks over the course of 30 years, consistent with the proposal that distinct strains of EHV-1 circulate in the field. Moreover, there is evidence that certain strain groups are geographically restricted, being recovered predominantly from outbreaks occurring in either North America or Europe. Significantly, variation of a single amino acid of the DNA polymerase is strongly associated with neurological versus nonneurological disease outbreaks. Strikingly, this variant amino acid occurs at a highly conserved position for herpesvirus DNA polymerases, suggesting an important functional role.

Amino Acid Sequence↗
PubMed2000

Development and evaluation of ELISA procedures to detect antibodies against the major envelope protein (G(L)) of equine arteritis virus.

Enzyme-linked immunosorbant assays (ELISAs) were developed for the detection of antibodies against the major envelope glycoprotein (G(L)) of equine arteritis virus (EAV). A 6-Histidine tagged recombinant protein expressing the complete G(L) ectodomain (G(L)-6His), a glutathione-S-transferase recombinant protein expressing amino acids 55-98 of G(L) (G(L)-GST) and an ovalbumin-conjugated synthetic peptide representing amino acids 81-106 of G(L) (G(L)-OVA) were used as diagnostic antigens. An ELISA procedure was developed and optimised for each antigen. The G(L)-OVA and G(L)-6His assays showed the greatest specificity while the G(L)-GST assay was slightly more sensitive that the G(L)-OVA and G(L)-6His assays; results based on the analysis of 50 virus neutralisation positive and 50 virus neutralisation negative sera. The G(L)-OVA ELISA was selected for further evaluation since it was simpler to use than ELISAs based on recombinant antigens and did not suffer from background reactivity. The final sensitivity and specificity of the G(L)-OVA ELISA were 96.75 and 95.6%, respectively, results based on the analysis of 400 virus neutralisation positive and 400 virus neutralisation negative sera. It also detected EAV antibody (100% efficiency) in seropositive shedding stallions and, in ponies infected experimentally with the UK93 isolate of EAV, the appearance of virus neutralising antibodies and G(L)-OVA ELISA-specific immunoglobulins coincided.

Animals↗
PubMed2000

Functional characterization of the PS II-LHC II supercomplex isolated by a direct method from spinach thylakoid membranes.

Recently, a novel procedure to isolate a highly pure and active Photosystem II preparation directly from thylakoid membranes, referred to as PS II-LHC II supercomplex, was reported [Eshaghi et al. (1999) FEBS Lett 446: 23-26]. In addition to the reaction center core proteins, the supercomplex contains all the extrinsic proteins of the oxygen evolving complex and a set of chlorophyll a/b binding proteins. In this paper, the functional properties of this isolated supercomplex are further characterized by using EPR spectroscopy, thermoluminescence, fluorescence relaxation kinetics and flash induced oxygen yield measurements. The PS II-LHC II supercomplex contains, in addition to Q(A) and Q(B), a small pool of plastoquinone (PQ). Although the isolated complex is no longer membrane bound, it has preserved functional characteristics of a well defined PS II preparation with the exception of some modification of Q(B) sites.

Journal Article↗
PubMed1998

Comparison of the functional properties of the monomeric and dimeric forms of the isolated CP47-reaction center complex.

Chlorophyll fluorescence, thermoluminescence, and EPR spectroscopy have been used to investigate the functional properties of the monomeric and dimeric forms of the photosystem II CP47-reaction center (CP47-RC) subcore complex that was isolated (Zheleva, D., Sharma, J., Panico, M., Morris, H. R., and Barber, J. (1998) J. Biol. Chem. 273, 16122-16127). Chlorophyll fluorescence yield changes induced either by the initiation of continuous actinic light or by repetitive light flashes indicated that the dimeric, but not the monomeric, form of the CP47-RC complex showed secondary electron transport properties indicative of QA reduction. Thermoluminescence measurements also clearly distinguished the monomer from the dimer in that the latter showed a ZV band, which appeared at -55 degreesC, following illumination at -80 degreesC. This band has been determined to be an indicator of the photoaccumulation of QA-. The ability of the dimeric CP47-RC to show secondary electron transport properties was clearly demonstrated by EPR studies. The dimer was characterized by organic radical signals at about g = 2 induced either by illumination or by the addition of dithionite. The dithionite-induced signal was attributed to QA-, but there was no indication of any interaction with non-heme iron. The signal induced by light was more complex, being composed not only of the QA- radical but also of radicals generated on the donor side. Difference analyses indicated that one of these radicals is likely to be due to a D1 tyrosine 161 or D2 tyrosine 161. In contrast, the monomeric CP47-RC complex did not show similar EPR-detectable radicals and instead was dominated by a high yield of the spin-polarized triplet signal generated by recombination reactions between the oxidized primary reductant, pheophytin, and the primary donor, P680. It is also concluded from EPR analyses that both the monomeric and dimeric forms of the CP47-RC subcore complex contain one cytochrome b559 per reaction center. Overall the results suggest that photosystem II normally functions as a dimer complex and that monomerization at the level of the CP47-RC subcore complex leads to destabilization of the bound plastoquinone, which functions as QA.

Cytochrome b Group↗
PubMed1998

Design and delivery of non-parenteral vaccines.

Non-parenteral delivery of vaccines is reviewed focusing on the delivery systems that have been used for various mucosal routes of administration. Systems considered include biodegradable micro- and nanoparticles, liposomes, live bacterial and viral vectors and mucosal adjuvants. New approaches to mucosal vaccine formulation using: (i) gene fusion technology to create non-toxic derivatives of mucosal adjuvants, (ii) genetically inactivated antigens with a deletion in an essential gene, (iii) coexpression of an antigen and a specific cytokine that is important in the modulation and control of a mucosal immune response, and (iv) genetic material itself that would allow DNA or RNA uptake and its endogenous expression in the host cell are described.

Animals↗
PubMed1985

International scientific meetings: relation between structure and function.

Increasing pressure is being placed on the scientific community to evaluate research activities. Scientific meetings consume a small but important fraction of the research budget. Audit of a well established series of scientific meetings showed that they met their immediate objectives in that they were international and multidisciplinary and provided a forum in which all participants actively contributed to discussion. The meetings had a positive outcome for the participants, leading in many cases to the subsequent exchange of research material (60% of participants) and to the establishment of collaborative research projects (31%). The impact of the meetings on the scientific community at large was assessed by citation analysis, which showed that the proceedings were cited early, often, and over a substantial period.

Australia↗
PubMed1981

Evaluation of double contrast barium enemas performed by radiographic technologists.

This study was undertaken to see if radiographic technologists could be trained to perform double contrast barium enemas of a quality comparable to that produced by gastrointestinal radiologists and radiology residents. One technologist was from a remote rural hospital and the other from a university gastrointestinal radiology department. After initial training the two technologists continued to produce work of high quality. Analysis of the films showed that there was no significant difference between those films produced in the rural hospital and in the university centre. We recommend more widespread training of radiographic technologists in this work.

Barium Sulfate↗
PubMedDate not supplied

Understanding lesbians' mammography utilization.

Lesbians face unique barriers to health care, and may be at higher risk for breast cancer than are other women. Yet, no research on lesbians and mammography utilization exists. We conducted telephone interviews of 107 lesbians aged 51-80, of whom 68 had had mammograms in the last year and 39 had not. Responses to open-ended questions identified the barriers lesbians face in obtaining mammography, lesbians, reasons for obtaining mammograms, and factors that would help lesbians obtain mammograms. Some issues identified were particular to lesbians; many issues were common to those identified by general samples of women (which include lesbians).

Aged↗
PubMedDate not supplied

Intra-arterial blood pressure monitoring in the neonate.

The advent of intra-arterial pressure monitoring has had a significant impact on the nursing care given in the neonatal intensive care unit. The nurse working in these units must become technically competent in monitoring techniques as well as clinically acute to physiologic measurements and their significance. These skills can be incorporated into planning and providing effective, individualized patient care. Continuous intra-arterial pressure monitoring is an invaluable clinical tool when caring for critically ill neonates. With care, an intra-arterial monitoring system can be easily prepared. This procedure requires minimal nursing time for care and maintenance and is a very safe procedure if appropriate nursing precautions are followed.

Arteries↗