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Biomedical subjects

P D Kiely

Publications and source records attributed to P D Kiely.

At least 19 recordsLinked to original sources
PubMed2006

Exploiting new systems-based strategies to elucidate plant-bacterial interactions in the rhizosphere.

The rhizosphere is the site of intense interactions between plant, bacterial, and fungal partners. In plant-bacterial interactions, signal molecules exuded by the plant affect both primary initiation and subsequent behavior of the bacteria in complex beneficial associations such as biocontrol. However, despite this general acceptance that plant-root exudates have an effect on the resident bacterial populations, very little is still known about the influence of these signals on bacterial gene expression and the roles of genes found to have altered expression in plant-microbial interactions. Analysis of the rhizospheric communities incorporating both established techniques, and recently developed "omic technologies" can now facilitate investigations into the molecular basis underpinning the establishment of beneficial plant-microbial interactomes in the rhizosphere. The understanding of these signaling processes, and the functions they regulate, is fundamental to understanding the basis of beneficial microbial-plant interactions, to overcoming existing limitations, and to designing improved strategies for the development of novel Pseudomonas biocontrol strains.

Bacterial Physiological Phenomena↗
PubMed2003

Hurling-related hand injuries.

Hurling is a contact sport, associated with significant morbidity. We have identified specific hand injuries sustained by participants and quantified the functional and financial implications of these injuries. Over a 3-month period, all hand injuries seen in the fracture clinic of our regional trauma unit were studied prospectively. Of the 123 consecutive injuries, 41 (33%) were sustained during hurling matches. Metacarpal (47%) and proximal phalangeal (37%) fractures were the most frequent. Eight hurlers (20%) required surgical intervention. Only four (10%) of the injured players were wearing hand protection. The mean cost of injury to the player was pound 615. We suggest the introduction of the mandatory use of hand protection for hurling.

Adolescent↗
PubMed2003

The treatment of flexion contracture of the knee using the Ilizarov technique in a child with haemophilia B.

Severe factor IX deficiency is an X-linked disorder which gives rise to spontaneous and often life-threatening bleeds. The major source of morbidity worldwide is recurrent haemarthroses, giving rise to joint destruction and deformity. However, the incidence of spontaneous haemarthroses has decreased since the advent of prophylactic home-based, on-demand, early replacement therapy. We present the case of a non-ambulant, 13-year-old boy from Chernobyl, who did not have access to this type of treatment, and whose deformity was managed using the Ilizarov external fixator. An external fixator was applied under general anaesthetic in theatre. Haemostasis was achieved by maintaining his FIX levels at 1.0 IU mL(-1) pre- and post-operatively. Three months later, the fixed flexion deformity had been reduced from 50 to 5 degrees. Four months postsurgery, this boy was walking freely without pain. There was no peri- or post-operative bleeding or joint swelling.

Adolescent↗
PubMed2002

Diethylmaleate, a pro-oxidant, attenuates experimental ischaemia-reperfusion-induced lung injury.

BACKGROUND: Systemic ischaemia-reperfusion (IR) injury is in part an oxidant injury mediated by neutrophils. Diethylmaleate (DEM), an intracellular pro-oxidant agent, has been shown to alleviate neutrophil-mediated tissue injury. The aim of this study was to evaluate whether DEM could have a protective effect on neutrophil-mediated lung injury in an animal model of lower-torso IR. METHODS: Sprague-Dawley rats (seven per group) were randomized into three groups. The control group underwent midline laparotomy only; the IR group underwent laparotomy and clamping of the infrarenal abdominal aorta for 30 min followed by 2 h of reperfusion; and the third group was pretreated with DEM 6 mmol/kg intraperitoneally 1 h before the IR insult. RESULTS: IR resulted in a significant increase in both microvascular leakage and pulmonary neutrophil infiltration as measured by bronchoalveolar lavage protein concentration and pulmonary myeloperoxidase activity respectively. Pretreatment with DEM significantly attenuated both microvascular leakage and neutrophil infiltration. CONCLUSION: Preconditioning with DEM protected against IR-induced lung injury. This protective effect raises the possibility of using pro-oxidants to prevent inflammatory injury.

Animals↗
PubMed2000

Immunosuppressant effect of gold on IgG subclasses and IgE; evidence for sparing of Th2 responses.

We set out to examine the effect of gold treatment on the Th2-dependent antibodies IgG4 and IgE in relation to other IgG subclasses in patients with rheumatoid arthritis (RA). Eighty-five gold-treated RA patients and 82 RA controls were studied. Serum IgG subclass concentrations were measured by ELISA, IgE was measured by automated enzyme immunoassay. Samples were studied serially in 13 gold-treated patients and in 11 patients with gold-induced adverse events. There was a significant reduction in the concentration of IgG1, IgG2 and IgG3 in gold-treated RA patients compared with RA controls (P 0.004-0.019), whereas IgG4 was less significantly reduced in gold-treated patients (P = 0.044) and there was no difference in IgE. In serial samples there was a significant fall in the concentration of IgG1 (P = 0.001), IgG2 (P = 0.001) and IgG3 (P = 0.026) with time but no change in IgG4 and IgE. The development of gold-induced adverse events was not associated with any change in the concentration of each IgG subclass or IgE. Deficiencies of IgG subclasses were found in 30% of gold-treated RA patients and 8.5% of RA controls, and were associated in gold-treated patients with a longer disease duration (P = 0.003) and with erosive disease (P = 0. 03). IgG2 was affected most frequently and in the majority of these cases subnormal specific IgG2 binding to widespread polysaccharide antigens (Pneumovax II) was found. Gold induces an overall immunosuppressant effect on IgG subclasses, with a deficiency in 21. 5%, adjusted for controls. The effect on the Th2-dependent antibodies IgG4 and IgE is less marked, suggesting a sparing of Th2 responses.

Antirheumatic Agents↗
PubMed1997

Mercuric chloride-induced vasculitis in the Brown Norway rat: alpha beta T cell-dependent and -independent phases: role of the mast cell.

Mercuric chloride induces a necrotizing vasculitis in the Brown Norway (BN) rat. This occurs in two phases, between 1 and 5 days (early) and between 12 and 20 days (late) after initiation of HgCl2. One outbred and four inbred rat strains were found to be susceptible to early vasculitis, but only the BN strain developed late vasculitis. In the BN strain, treatment with the mAb R73 (anti-alpha beta TCR) inhibited T cell function, completely prevented the late vasculitis, but had no effect against early vasculitis, indicating that early and late vasculitis is controlled by different genetic and cellular mechanisms. The role of the mast cell in the alpha beta T cell-independent early phase was studied. Serum concentrations of rat mast cell protease II rose following HgCl2 treatment, indicating mast cell degranulation. The reagents Doxantrazole and the mAb G63, which suppress mast cell secretory responses, also prevented the rise in rat mast cell protease II and significantly reduced the early vasculitis. The demonstration of an alpha beta T cell-dependent phase supports previous experimental data that T cells play an important role in the pathogenesis of vasculitis. The presence of an earlier alpha beta T cell-independent phase is a unique observation. The data support a role for the mast cell in the early vasculitis.

Animals↗
PubMed1996

Anti-CD8 treatment reduces the severity of inflammatory arthritis, but not vasculitis, in mercuric chloride-induced autoimmunity.

Mercuric chloride (HgCl2) induces a T cell-dependent autoimmune syndrome in Brown-Norway (BN) rats characterized by a humoral response, tissue injury with an accumulation of CD8+ and CD4+ T cells, and an increase in tissue IL-4 mRNA and serum IgE suggesting Th2 cell activation. In other models of autoimmune disease, CD8+ cells act in both anti- and pro-inflammatory capacities, suggesting that functionally distinct CD8+ populations exist in vivo. The effect of treatment with OX8, a depleting anti-CD8 MoAb, on the initiation of HgCl2-induced autoimmunity was assessed in two experiments in a total of 20 BN rats, and compared with 20 animals treated with a control MoAb or PBS. OX8 significantly depleted peripheral blood CD8+ lymphocytes, had no effect on HgCl2-induced anti-collagen or myeloperoxidase antibodies, nor on the incidence or severity of caecal vasculitis. The severity of HgCl2-induced arthritis was significantly reduced in OX8-treated animals; median peak score reduced from 7.5 to 3.0 (experiment 1) and from 7.0 to 4 (experiment 2) (P = 0.009, Mann-Whitney U-test). OX8 treatment also exacerbated the early rise in HgCl2-induced IgE and induced a significant rise in plasma interferon-gamma (IFN-gamma), suggesting that CD8+ cells may have a regulatory influence on Th cell populations. These data provide direct evidence that CD8+ cells may act in a proinflammatory capacity in both this model of autoimmunity and the pathogenesis of inflammatory arthritis.

Animals↗
PubMed1995

Oxpentifylline inhibits tumor necrosis factor-alpha mRNA transcription and protects against arthritis in mercuric chloride-treated brown Norway rats.

The phosphodiesterase inhibitor oxpentifylline (OXP) has a number of potentially important immunomodulatory actions which include a selective inhibition of the Th1 subset of CD4+ cells in vitro and inhibition of tumor necrosis factor (TNF)-alpha mRNA transcription. In vivo, it has a dramatic protective effect against experimental allergic encephalomyelitis. In this animal model, tissue injury is associated with both a Th1 response and with TNF-alpha production, either of which could be targets for the protective action of OXP. In an attempt to clarify the relative importance of the Th cell subsets and TNF-alpha in pathogenesis, we investigated the effect of OXP on a Th2 model of T cell-dependent disease, mercuric chloride (HgCl2)-induced autoimmunity in the Brown Norway rat. The effects of OXP on the Th1:Th2 response, TNF-alpha mRNA transcription in spleen and ankle joints, and on the incidence and severity of arthritis and cecal vasculitis have been examined and the effects in vivo have been compared with those of a soluble TNF receptor-IgG1 fusion protein (sTNFR) that neutralizes rat TNF-alpha. In two separate experiments, OXP significantly enhanced unstimulated levels of splenic interleukin-4 (IL-4) mRNA (median 62%, of an artificial IL-4 mRNA construct, vs. 36.5% in controls) and in one experiment, exaggerated the total IgE response to HgCl2. OXP inhibited HgCl2-induced TNF-alpha mRNA transcription in spleen and ankle joints. In three separate experiments, OXP had a significant protective effect against arthritis, with the mean incidence reduced from 100% to 30% and mean peak score reduced from 7.2 to 2.59 (experiments 1 and 2). The protection against arthritis was indistinguishable from that produced by sTNFR. There was no such protection against cecal vasculitis with either OXP or sTNFR. These results demonstrate that OXP induces a shift towards a Th2 response, inhibits TNF-alpha mRNA transcription locally in joint and systemically in spleen, and has a protective effect against arthritis similar to that produced by sTNFR in the HgCl2-treated BN rat. We conclude that TNF-alpha is a critical cytokine in the pathogenesis of arthritis but not cecal vasculitis in this model, and that inhibition of TNF-alpha transcription is the most important mode of action of OXP in this situation. OXP may be a potential therapeutic agent in the treatment of other arthritides, such as human rheumatoid arthritis, in which TNF-alpha has been implicated in pathogenesis.

Animals↗
PubMed1995

Erythrocyte aplasia and systemic lupus erythematosus.

Pure erythrocyte aplasia is a recognised feature of systemic lupus erythematosus (SLE); here we report two cases, one predating the onset of SLE, the other following a long period of disease quiescence. One case demonstrates the typical features of this disorder and was successfully treated with prednisolone. The second case is unusual in being resistant to immunosuppressive treatment. Bone marrow culture from the second patient revealed an inhibition of BFU-E colony formation in the presence of the patient's serum, indicating that a serum inhibitor of haemopoiesis was present. Furthermore, following T cell depletion of this patient's marrow, there was an increase in BFU-E, CFU-G and CFU-GM colony growth implicating, in addition, a possible T cell-mediated inhibition of marrow haemopoiesis. This is a novel observation and may explain the resistance shown by this patient to standard treatment.

Adult↗
PubMed1995

Inflammatory polyarthritis induced by mercuric chloride in the Brown Norway rat.

BACKGROUND: Mercuric chloride (HgCl2) induces an autoimmune syndrome in susceptible strains of rodent. In the Brown Norway (BN) rat, this is characterized by autoreactive T cells, high levels of total IgE, IgG autoantibodies, including anti-collagen types I and II, and tissue injury, including glomerulonephropathy and necrotizing vasculitis of the gut. The high total IgE levels and evidence showing ex vivo down-regulation of IFN gamma and in vivo up-regulation of IL-4 suggest that HgCl2-induced autoimmunity occurs in a Th2 lymphokine environment. EXPERIMENTAL DESIGN: HgCl2-autoimmunity was induced in BN rats using standard methods. Anti-collagen (types I and II) Ab and IgG subclasses were measured by ELISA. Arthritis was scored on Days 13 to 17 after HgCl2 treatment. Ankle joints and synovium were examined with standard histologic and immunohistochemical techniques. The incidence and severity of arthritis were compared in normal and R73 (anti-alpha/beta T cell receptor mAb)-treated BN rats. After R73 treatment, T cell function was assessed by measuring the total IgE and anti-type II collagen response to HgCl2, and FACS was used to assess the number of peripheral blood OX19+ lymphocytes (T cell marker). RESULTS: A self-limiting inflammatory arthritis develops in more than 82% of animals and is more severe in males. Histologically, there is a predominant ED1+ macrophage synovial infiltrate, areas of fibrinoid necrosis, and vasculitis and erosions of cartilage. The peak anti-collagen (type I and II) Ab titer does not correlate with arthritis incidence or severity. Treatment with R73 markedly reduces the rise in total IgE and IgG anti-type II collagen, reduces OX19+ peripheral blood lymphocytes, and abolishes the arthritis. CONCLUSIONS: HgCl2 induces a T cell-dependent inflammatory arthritis in the BN rat. In contrast with other animal models, HgCl2-induced arthritis is associated with an apparent Th2 lymphokine response.

Animals↗
PubMed1995

Upper limb lymphatic function in inflammatory arthritis.

OBJECTIVE: To determine the effect of inflammatory arthritis on lymphatic function in the upper limb. METHODS: Lymphoscintigraphy was used to measure lymphatic drainage in the upper limbs of 3 groups of patients: Group 1, inflammatory arthritis and edema (N = 10); Group 2, inflammatory arthritis and no edema (N = 18); and Group 3, healthy controls (N = 11). RESULTS: Lymphatic drainage was reduced significantly in Group 1 but was the same in Groups 2 and 3. Multiple regression analysis failed to show any effect of arthritis on lymphatic drainage. CONCLUSION: Inflammatory arthritis alone does not impair lymphatic drainage in the upper limbs. The results suggest that the presence of edema is primarily attributable to an unrelated abnormality influencing lymphatic function.

Adult↗
PubMed1994

Upper limb lymphedema associated with polyarthritis of rheumatoid type.

OBJECTIVE: To determine the cause of upper limb edema in 8 patients with peripheral polyarthritis of rheumatoid-type. METHODS: Objective assessment of lymph function using quantitative lymphoscintigraphy. RESULTS: Seven cases with either rheumatoid or psoriatic arthritis were found to have impaired lymph drainage associated with edema. All cases shared a distal rheumatoid pattern of arthritis but showed no relation between severity of lymphatic impairment and either duration or severity of arthritis. CONCLUSION: Polyarthritis of rheumatoid-type may be associated with lymphedema due to impaired lymphatic function.

Adult↗