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D G Jones

Publications and source records attributed to D G Jones.

At least 55 records · Page 3Linked to original sources
PubMed1999

Prime position.

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Cumulative Trauma Disorders↗
PubMed1998

Eosinophil-specific biological activity of recombinant ovine interleukin-5.

Recombinant ovine interleukin-5 (rovIL-5) expressed from Chinese hamster ovary (CHO) cells was tested for cell-specific bioreactivity, in vitro, in a soft agar clonogenic assay and in an enzyme-based microassay for eosinophil potentiating activity (EPA). In soft agar assays, colony and cluster formation from sheep bone marrow cells (SBMC) incubated with rovIL-5 was significantly enhanced compared with SBMC incubated with control supernatants from mock-transfected CHO cells. Colony analysis at 14 days demonstrated that for three separate rovIL-5 preparations 45%, 61% and 66% of colonies were eosinophilic, as were 55%-71% of clusters. In contrast, no eosinophil colonies were detected in parallel control cultures. RovIL-5 was also shown to possess potent and dose-responsive EPA, on the basis of eosinophil peroxidase (EPO) and arylsulphatase (EAS) assay in 7 day SBMC cultures. This activity was inhibited in a dose-responsive manner by TRFK-5, a rat anti-murine IL-5 monoclonal antibody (MAb) previously shown to have cross-reactivity in the ovine EPA assay. The results demonstrate that rovIL-5 exhibited eosinophil-specific properties similar to those of IL-5 derived from other mammalian species.

Agar↗
PubMed1998

Exploring structure-activity relationships around the phosphomannose isomerase inhibitor AF14049 via combinatorial synthesis.

Phosphomannose Isomerase (PMI) has been shown by genetic methods to be an essential enzyme in fungal cell wall biosynthesis. The PMI inhibitor AF14049 was discovered as an unanticipated side product from high-throughput library screening against the enzyme from C, albicans. Solid-phase synthetic methods were developed and a series of libraries and discrete analogs synthesized to explore SAR around AF14049.

Amides↗
PubMed1998

Early immunopathological events in experimental ovine paratuberculosis.

An experimental oral infection of neonatal (< 2 weeks old) lambs with a cervine isolate of Mycobacterium avium subspecies paratuberculosis (M.a. paratuberculosis), the causal agent of ruminant paratuberculosis (Johne's disease) was used to investigate bacteriological, histopathological and immunological changes during the early (up to 8 weeks) post-infection phase. In vitro culture for mycobacteria was positive in one faecal and three mesenteric lymph node (MLN) samples from the eight infected lambs. All mycobacterial isolates from MLN were identified as M.a. paratuberculosis by polymerase chain reaction (PCR). Small-to-medium sized focal granulomata were observed in jejunal (JPP) and ileal Peyer's patches (IPP) from four of the eight infected lambs. Compared with controls, JPP from all infected lambs had significantly (p < 0.05) higher proportions of CD8+ and CD2+ lymphocytes, and there were significantly (p < 0.05) fewer cells expressing B lymphocyte-associated markers in IPP and MLN. The T/B cell ratio was significantly (p < 0.05) increased in both JPP and MLN from infected lambs. The expression of a range of genes for cytokines was examined using specific reverse transcriptase PCR (RT-PCR) amplification of messenger RNA (mRNA) template isolated from MLN, JPP and IPP from both groups of animals. Densitometric analyses indicated that, in infected animals, MLN expressed significantly (p < 0.05) more mRNA for TNF-alpha: JPP had significantly increased (p < 0.05) mRNA for GM-CSF and significantly decreased (p < 0.05) mRNA for IL-4 and IFN-gamma. Infected lambs had significantly (p < 0.05) decreased titres of both circulating IgG and gut mycobacteria-associated IgG antibody. Infection was not associated with any consistent changes in lymphocyte reactivity to specific mycobacterial antigens, IFN-gamma release into supernatants from in vitro intestinal lymphocyte cultures or gut IgA antibody levels.

Animals↗
PubMed1998

Anatomy and ethics: an exploration of some ethical dimensions of contemporary anatomy.

Anatomy and ethics have traditionally been viewed as inhabiting different conceptual worlds on the assumption that the practice of anatomy is ethically neutral. This assumption is challenged by critiquing the nature of anatomy and by demonstrating that ethical issues pervade anatomical study. This should come as no surprise since anatomy deals with the structure of the human body, and it is the human body and human tissues that are central to bioethical questions concerning human life in both health and disease, at its beginning and end and in research and clinical practice. Furthermore, many issues of interest to anatomists, such as the mechanisms of organ and fetal tissue transplantation, the neurological bases of aging and dementia, and definitions of brain death, are best tackled by venturing into questions usually dealt with in a clinical context. By the same token, a number of clinical issues can be approached helpfully from starting points provided by anatomy, although they too have ethical dimensions. To illustrate the close interrelationship between anatomical and ethical issues, two topic areas are discussed: research on archeological human remains and the notion of the pre-embryo.

Anatomy↗
PubMed1998

Regeneration in the central nervous system: pharmacological intervention, xenotransplantation, and stem cell transplantation.

The factors inhibiting regeneration in the central nervous system (CNS) have been elaborated, debated, and studied for the past 70 years. Recent work has pointed to the fine balance that exists between repair and regeneration following CNS injury. Growth factors have featured prominently in this debate. In attempts to tip the scales toward regeneration and functional reconnection to damaged neurons, pharmacological intervention has come to the fore. However, a perennial concern has been that much of regeneration may be aberrant, although there is now evidence to suggest that this fear may have been exaggerated. In searching for additional avenues for achieving therapeutic reconstruction of damaged neural pathways, transplantation studies occupy a prominent place in the literature. Various principles have become established, and these have proved relevant for all approaches utilizing grafts. Xenotransplantation and stem cell transplantation are approaches with exciting potential. Circuitry can be effectively restored by xenotransplantation, including early indications of integration of pig dopaminergic neurons in Parkinson's disease. The considerable possibilities offered by the differentiation of neural stem cells into progenitor cells and then into neurons and glia are explored.

Animals↗
PubMed1998

Curriculum developments in Australasian anatomy departments.

This article explores the nature of the 12 anatomy departments in Australian and New Zealand medical schools. The transformation of these departments from medically oriented to science-oriented ones is examined. Contemporary trends in staffing, research emphases, and teaching methodologies are discussed, and recent developments in medical curricula reviewed. The relationship between medical courses and the teaching of science and health science students in Australasian departments is discussed. Finally, the state of anatomy as a discipline and possibilities for its future development are explored.

Anatomy↗
PubMed1998

Radiation use in the orthopaedic theatre: a prospective audit.

BACKGROUND: There is concern about the exposure of orthopaedic surgeons to radiation. The aim of this study was to monitor radiation use in theatre to improve practice and to attempt to quantify the radiation dose the orthopaedic surgeon may have received. METHODS: A 6-month prospective audit of all procedures performed in the orthopaedic theatre that used fluoroscopy or radiographs was undertaken An anthropomorphic phantom was used to measure scatter and direct-skin doses. Screening times were recorded in a subsequent 6-month post at a tertiary trauma centre. RESULTS: Fluoroscopy or radiographs were used in 378 procedures. Fluoroscopy was used in 260 procedures with a screening time of 124 min at an average of 0.48 min per procedure. Lead aprons were worn in 99% of cases and thyroid guards in 32%. All dosimeter badges were negative. The surgeon's hand was caught in the fluoroscopy beam in 15% of procedures. The phantom recordings ranged from 13 to 210 microGy for skin dose and 0.17-0.87 microGy for scatter dose. The calculated hand exposure was less than 5% of recommended levels. In the trauma post 210 min of screening was used potentially increasing the hand exposure to one-third of recommended limits. If a printer was used to record the image, 58% of intra-operative radiographs would have been avoided. CONCLUSIONS: Hand exposure to radiation is the limiting factor in orthopaedics. The extremity limit will only be exceeded if the hands are regularly caught in the beam. Dose-reduction gloves should be considered for high-risk procedures. A printer can reduce the need for intraoperative plain radiographs.

Body Burden↗
PubMed1998

The problematic symmetry between brain birth and brain death.

The possible symmetry between the concepts of brain death and brain birth (life) is explored. Since the symmetry argument has tended to overlook the most appropriate definition of brain death, the fundamental concepts of whole brain death and higher brain death are assessed. In this way, a context is provided for a discussion of brain birth. Different writers have placed brain birth at numerous points: 25-40 days, eight weeks, 22-24 weeks, and 32-36 weeks gestation. For others, the concept itself is open to question. Apart from this, it needs to be asked whether a unitary concept is an oversimplification. The merits of defining two stages of brain birth, to parallel the two definitions of brain death, are discussed. An attempt is then made to map these various stages of brain birth and brain death onto a developmental continuum. Although the results hold biological interest, their ethical significance is less evident. Development and degeneration are not interchangeable, and definitions of death apply specifically to those who are dying, not those who are developing. I conclude that while a dual concept of brain death has proved helpful, a dual concept of brain birth still has problems, and the underlying concept of brain birth itself continues to be elusive.

Beginning of Human Life↗