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D Wakefield

Publications and source records attributed to D Wakefield.

At least 19 recordsLinked to original sources
PubMed2006

Toll-like receptors in ocular immunity and the immunopathogenesis of inflammatory eye disease.

Microbial agents have an important role in the pathogenesis of various inflammatory eye diseases, such as uveitis and keratitis. Microbial infections of the eye such as microbial keratitis, ocular onchocerciasis, bacterial endophthalmitis, viral retinitis, and other infectious uveitis are unfortunately common. In addition, microbial agents have been implicated in the pathogenesis of "non-infectious" immune mediated diseases such as HLA-B27 associated acute anterior uveitis. Toll-like receptors (TLR) are a family of pattern recognition receptors that initiates rapid host innate immune response to microbial components known as pathogen associated molecular patterns, which are unique to a given class of microbes, such as lipopolysaccharide of Gram negative bacteria. Recent in vitro and in vivo studies have demonstrated the expression and function of TLRs in the eye, with significant implications for better understanding of ocular immunity and the pathogenesis of inflammatory eye diseases affecting the cornea, uvea, and retina.

Eye↗
PubMed2004

Production of pro-inflammatory cytokines correlates with the symptoms of acute sickness behaviour in humans.

BACKGROUND: Elaboration of the concept of cytokine-induced sickness behaviour in recent years has opened new avenues for understanding brain involvement in sickness and recovery processes. Additionally, this has led to much speculation about the role of the immune system in neuropsychiatric syndromes, including depression and chronic fatigue. However, few studies have examined this phenomenon as it naturally occurs in sick humans, and none has attempted to document the quantitative relationships between cytokine levels and non-specific symptoms. The aim of this research was to examine human sickness behaviour and its immunological correlates in documented Epstein-Barr virus (EBV), Q fever or Ross River virus (RRV) infections. METHOD: We studied two separate samples. The first consisted of 21 patients with acute Q fever. The second included 48 patients with acute RRV or EBV infection. Psychological and somatic symptom profiles were derived from self-report measures completed at enrolment. Quantification of proinflammatory cytokines [interleukin (IL)-1beta and IL-6] in sera and supernatants of peripheral blood mononuclear cell (PBMC) cultures was undertaken by specific ELISAs. RESULTS: Levels of IL-1beta and IL-6 spontaneously released from PBMC cultures were consistently correlated with reported manifestations of acute sickness behaviour including fever, malaise, pain, fatigue, mood and poor concentration. CONCLUSIONS: IL-1beta and IL-6 produced as part of the host response represent sensitive markers of sickness behaviour in humans with acute infection. Further work is needed to systematically characterize the spectrum and natural history of sickness behaviour in humans and to elucidate its biological basis.

Acute Disease↗
PubMed2004

Factors contributing to the cause of a community outbreak of tuberculosis.

The diagnosis of pulmonary tuberculosis (TB) in a nursery teacher led to a total of 282 adults and children being screened for TB, and 67 of these contracted the condition. Latent and active factors mitigated against earlier diagnosis of the disease during the multiple contacts by the teacher with the healthcare system over 18 months. A series of barely inter-linked events meant that the system failed the patient and consequently the contacts who contracted the disease. The system errors were widespread and render possible a similar occurrence elsewhere.

Adult↗
PubMed2003

Role and regulation of CXC-chemokines in acute experimental keratitis.

The aim of this study was to elucidate the expression of chemokines, their role and regulation in bacterial corneal infection using three bacterial strains (Pseudomonas. aeruginosa- invasive, cytotoxic and contact lens induced acute red eye strains) which have been shown to produce three distinct patterns of corneal disease in the mouse. The predominant chemokine expressed in response to all three strains was MIP-2. Prolonged expression of high levels of MIP-2 was associated with increased severity of corneal inflammation. Significantly reduced disease severity upon administration of anti-MIP-2 antibodies suggested that MIP-2 may play an important role in the pathogenesis of Pseudomonas keratitis at least in part by being a major chemoattractant for polymorphonuclear leukocytes (PMN) recruitment. Interestingly, the numbers of bacteria in eyes with neutralized MIP-2 activity did not decrease even though the severity of the disease was decreased. This implies PMNs as the major destructive factor in microbial keratitis. Further, neutralization of IL-1beta activity alone using monoclonal antibodies resulted in significant reduction of both MIP-2 and KC activity indicating that chemokine levels were regulated by IL-1beta. These studies demonstrate that the regulation of MIP-2 activity may be beneficial in reducing corneal damage during microbial keratitis in rodents and perhaps that regulation of the human homologue of MIP-2, IL-8, may be useful for controlling keratitis in humans.

Acute Disease↗
PubMed2003

Expression and distribution of matrix metalloproteinases and their inhibitors in the human iris and ciliary body.

AIM: To determine the expression and distribution of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the normal human iris and ciliary body. METHODS: Seven postmortem human eyes were fixed with formalin. The iris and ciliary body were dissected out and embedded in paraffin. The expression of MMPs -1, 2, 3, and 9, and TIMPs 1-4 in the iris and ciliary body was determined by a novel immunofluorescence technique and the results graded by masked observers. RESULTS: Positive staining for MMPs and TIMPs was observed in all regions of the anterior uvea, and was more intense in the ciliary body than in the iris. Most MMPs and TIMPs showed similar patterns in their distribution. In the ciliary body, staining was strongest in the epithelium, and was localised to the epithelial cell cytoplasm, except for TIMP-3 which was strongly expressed in the basement membranes. In the iris, staining was most noticeable in the anterior border and anterior epithelial layer. Blood vessels in the stroma of the iris and ciliary body also stained moderately for MMPs and TIMPs. CONCLUSION: Both MMPs and TIMPs are widely expressed in the anterior uvea, with a positive correlation between their expressions. Their differential localisation in the ciliary body suggests they may have a role in maintaining homeostasis in the uveal tract.

Aged↗
PubMed2002

Balance of pro- and anti-inflammatory cytokines correlates with outcome of acute experimental Pseudomonas aeruginosa keratitis.

The purpose of this study was to elucidate the expression of pro- and anti-inflammatory cytokines in mouse corneas infected with Pseudomonas aeruginosa. Three bacterial strains (invasive, cytotoxic, or CLARE [contact lens-induced acute red eye]) which have recently been shown to produce distinct patterns of corneal disease in the mouse were used. The left mouse (BALB/c) corneas were scarified and infected with 2 x 10(6) CFU of one of the three P. aeruginosa strains, while right eyes served as controls. Animals were examined at 1, 4, 8, 16, and 24 h with a slit lamp biomicroscope to grade the severity of infection. Following examination, eyes were collected and processed for histopathology, multiprobe RNase protection assay for cytokine mRNA, enzyme-linked immunosorbent assay to quantitate cytokine proteins, and myeloperoxidase activity to quantitate polymorphonuclear leukocytes. The kinetics of appearance and magnitude of expression of key cytokines varied significantly in the three different phenotypes of P. aeruginosa infection. The predominant cytokines expressed in response to all three phenotypes were interleukin-1 beta (IL-1 beta), IL-1Ra, and IL-6. In response to the invasive strain, which induced severe corneal inflammation, significantly lower ratios of IL-1Ra to IL-1 beta were present at all time points, whereas corneas challenged with the CLARE strain, which induced very mild inflammation, showed a high ratio of IL-1Ra to IL-1 beta. The outcome of infection in bacterial keratitis correlated with the relative induction of these pro- and anti-inflammatory cytokines, and exogenous administration of recombinant rIL-1Ra (rIL-1Ra) was able to reduce the disease severity significantly. These findings point to the therapeutic potential of rIL-1Ra protein in possible treatment strategies for bacterial keratitis.

Acute Disease↗
PubMed2002

Neutrophil accumulation correlates with type IV collagenase/gelatinase activity in endotoxin induced uveitis.

BACKGROUND/AIM: Anterior uveitis is a common inflammatory ocular disease characterised by protein accumulation and leucocyte infiltration in the anterior chamber. The aim of this study was to determine the expression of gelatinases in the aqueous humour (AH) and uvea in an animal model of endotoxin induced uveitis (EIU). METHODS: EIU was established in Lewis rats following an intraperitoneal injection of lipopolysaccharide (LPS). AH and ocular tissue were obtained from control animals and those with EIU over a 1 week time course and the samples analysed immunohistochemically and by gelatin zymography. RESULTS: Matrix metalloproteinase (MMP) 2 and 9 levels were elevated in rat AH over a 1 week time course. MMP-2 and MMP-9 levels peaked at the time of maximum uveal inflammation, before returning to baseline levels as the inflammation subsided. MMP-9 was detected in the latent and functionally active form. Total protein extracted from inflamed rat uveal tissue displayed no significant gelatinolytic modulation throughout the time course of EIU. Anterior chamber neutrophils and ciliary body epithelial cells were the most abundant source of the gelatinases. CONCLUSION: This study has revealed a correlation between infiltrating neutrophils and the presence of elevated gelatinases in EIU. The results suggest that these proteolytically active enzymes may be important mediators of the inflammatory response and contribute to matrix remodelling observed in uveitis. Furthermore, the excess production of MMPs may be a mechanism by which leucocytes, such as neutrophils, gain access to uveal tissue and AH. Therapeutic strategies aimed at reducing MMP activity may be of some benefit in the treatment of uveitis.

Animals↗
PubMed2001

What is chronic fatigue syndrome? Heterogeneity within an international multicentre study.

OBJECTIVE: We sought to compare the characteristics of patients presenting with chronic fatigue (CF) and related syndromes in eight international centres and to subclassify these subjects based on symptom profiles. The validity of the subclasses was then tested against clinical data. METHOD: Subjects with a clinical diagnosis of CF completed a 119-item self-report questionnaire to provide clinical symptom data and other information such as illness course and functional impairment. Subclasses were generated using a principal components-like analysis followed by latent profile analysis (LPA). RESULTS: 744 subjects returned complete data sets (mean age 40.8 years, mean length of illness 7.9 years, female to male ratio 3:1). Overall, the subjects had a high rate of reporting typical CF symptoms (fatigue, neuropsychological dysfunction, sleep disturbance). Using LPA, two subclasses were generated. Class one (68% sample) was characterized by: younger age, lower female to male ratio; shorter episode duration; less premorbid, current and familial psychiatric morbidity; and, less functional disability. Class two subjects (32%) had features more consistent with a somatoform illness. There was substantial variation in subclass prevalences between the study centres (Class two range 6-48%). CONCLUSIONS: Criteria-based approaches to the diagnosis of CF and related syndromes do not select a homogeneous patient group. While substratification of patients is essential for further aetiological and treatment research, the basis for allocating such subcategories remains controversial.

Adult↗
PubMed2001

Expression of macrophage migration inhibitory factor during Pseudomonas keratitis.

Macrophage migration Inhibitory factor (MIF) is a recently rediscovered pro-inflammatory cytokine, and has been shown to play a role in the regulation of neutrophil chemokines and angiogenesis. Corneal epithelial and endothelial cells have been shown to express MIF. This study evaluated the expression of MIF during Pseudomonas keratitis in mice and in vitro using a corneal epithelial cell line. Three strains of P. aeruginosa, 6294 (invasive strain), 6206 (cytotoxic strain) and Paer1 (non-infectious strain) were used. Both cytotoxic and invasive strains were isolated from human corneal ulcers and the Paer1 strain was isolated from a non-infectious condition. Following challenge in mouse corneas or a corneal epithelial cell line, corneal homogenates or lysed corneal epithelial cells were used to isolate RNA. Migration inhibitory factor mRNA expression in the mouse cornea or human corneal epithelial cells was examined by reverse transcription-polymerase chain reaction analysis, and was found to be expressed as early as 4 h after the injury (scratch controls) or infection in the mouse corneas. Migration inhibitory factor mRNA in scratch controls and Paer1-inoculated corneas showed peak levels at 4 h post-challenge and this dropped by 24 h post-challenge. Corneas challenged with invasive and cytotoxic strains showed peak expression 24 h post-challenge. Migration inhibitory factor mRNA levels were significantly higher in invasive and cytotoxic strain inoculated corneas compared to Paer1 inoculated corneas. Challenging the corneal epithelial cell line with Pseudomonas 6294 and 6206 strains induced peak expression at 8 h and levels were decreased by 12 h. Epithelial cells inoculated with recombinant human interleukin-1beta protein induced very high levels of MIF mRNA at all time points compared to infected and control corneal epithelial cells. High expression of MIF in the infected corneas suggests that it may have a role in the pathogenesis of corneal disease induced by invasive and cytotoxic strains of P. aeruginosa.

Animals↗
PubMed2001

Regulatory role of IL-1beta in the expression of IL-6 and IL-8 in human corneal epithelial cells during Pseudomonas aeruginosa colonization.

Pseudomonas aeruginosa is a virulent pathogen and is frequently associated with bacterial keratitis. Recent studies have shown that high levels of interleukin (IL)-1beta and macrophage inflammatory protein-2 are associated with the severity of corneal infection. Interleukin-1beta is a principal inflammatory mediator. Understanding the regulatory role of IL-1beta would provide better understanding of host responses during P. aeruginosa corneal infection. A human corneal epithelial (HCE) cell line and three P. aeruginosa strains were used in this experiment. Confluent HCE cells were challenged with P. aeruginosa and monoclonal antihuman IL-1beta antibody (IL-1beta mAb). The culture supernatants were collected for measuring cytotoxicity and protein levels of IL-1beta, IL-8 and IL-6 by enzyme-linked immunosorbent assay. Results showed that HCE cells expressed low levels of IL-1beta and high levels of IL-6 and IL-8 during P. aeruginosa colonization. Paer1-colonized HCE cells produced higher levels of IL-1beta, IL-6 and IL-8 protein compared to those produced by 6206- and 6294-colonized HCE cells. Administration of IL-1beta mAb decreased the production of IL-8 and IL-6. In conclusion, P. aeruginosa-colonized HCE cells produced low levels of IL-1beta and high levels of IL-6 and IL-8. Neutralizing IL-1beta protein significantly downregulated the production of IL-8 and IL-6.

Cell Line↗
PubMed2001

Diagnosing pediatric asthma: validating the Easy Breathing Survey.

OBJECTIVE: To determine the sensitivity, specificity, and predictive value of a simple, self-administered questionnaire for the diagnosis of asthma in children. STUDY DESIGN: A questionnaire specifically designed to assist primary care providers in making a diagnosis of asthma in children was developed and administered in 4 different primary care and subspecialty clinics, validated, and then used as part of an asthma management program called Easy Breathing. Asthma diagnoses were made according to recommended National Asthma Expert Panel Guidelines. RESULTS: Four questions on the survey were shown to be sensitive and specific for asthma. The sensitivity was greater for all levels (mild, moderate, and severe) of persistent asthma than for mild, intermittent asthma. A positive response to any 1 of the 4 questions was over 94% sensitive for asthma; a negative response to all 4 questions was 55% specific for ruling out asthma. CONCLUSIONS: Patient responses to 4 specific respiratory symptom questions can assist primary care providers in diagnosing asthma in children. Primary care providers serving pediatric populations at high risk for asthma should consider asking patients or their parents these 4 questions regarding asthma symptoms on a regular basis.

Adolescent↗
PubMed2001

The role of IL-1beta in the regulation of IL-8 and IL-6 in human corneal epithelial cells during Pseudomonas aeruginosa colonization.

PURPOSE: Recent studies have shown that the levels of interleukin (IL)-1beta, IL-6 and IL-8 are associated with the severity of infectious diseases. The purpose of this study was to investigate whether IL-1beta regulates the expression of IL-6 and IL-8 in human corneal epithelial cells during Pseudomonas aeruginosa colonization. METHODS: Confluent immortalized human corneal epithelial cells were challenged with P. aeruginosa 6294 in the presence of anti-human IL-1beta antibody or matched control antibody. The cells were also challenged with recombinant IL-1beta protein without bacterial colonization. Expression of IL-1beta, IL-6 and IL-8 mRNA and protein was detected by reverse transcription (RT)-PCR and by enzyme-linked immunosorbent assay (ELISA), respectively. IL-1beta localization was determined by immunohistochemistry. RESULTS: Human corneal epithelial cells expressed low levels of IL-1beta and high levels of IL-6 and IL-8 during P. aeruginosa colonization. Addition of IL-1beta Ab resulted in a significant decrease (P < 0.05) in IL-8 protein expression at 4 h, 8 h and 12 h. Addition of IL-1beta Ab reduced IL-6 protein expression at 8 h and increased IL-6 protein expression at 12 h. Addition of recombinant IL-1beta protein alone strongly stimulated the expression of IL-8 and IL-6. Immunohistochemical staining showed that IL-1beta protein was present both intracellularly and extracellularly in P. aeruginosa colonized cells. CONCLUSIONS: IL-1beta is able to modulate expression of both IL-6 and IL-8 at transcriptional and post-transcriptional levels in human corneal epithelial cells.

Cells, Cultured↗
PubMed2001

Small intestinal mucosal immunity and morphometry in luminal overgrowth of indigenous gut flora.

OBJECTIVE: The aim of this study was to investigate the separate effects of indigenous oropharyngeal- and colonic-type flora on small intestinal mucosal immunity and morphometry in small intestinal bacterial overgrowth (SIBO). METHODS: A duodenal aspirate and random biopsies of underlying mucosa were obtained from 52 adult subjects (age range, 18-90 yr; median, 60 yr) without disorders that may otherwise disturb small intestinal histology or mucosal immunity. Villus height, crypt depth, villus/crypt ratios, counts of intraepithelial lymphocytes (IELs) and lamina propria total mononuclear cells, IgA, IgM, and IgG plasma cells, mast cells, and B and T lymphocytes were determined in relation to the presence or absence of SIBO and the nature of the overgrowth flora in all subjects. CD4+ve and CD8+ve T-cell counts were determined in 24 subjects. RESULTS: SIBO was present in 26 of 52 (50%) subjects. Overgrowth flora included colonic-type bacteria in 20 subjects and oropharyngeal-type flora alone in 6 subjects. Lamina propria IgA plasma cell counts were significantly increased in subjects with SIBO, irrespective of whether the overgrowth flora comprised oropharyngeal-type flora alone or included colonic-type bacteria. Neither villus height, crypt depth, villus/crypt ratios, nor total or other mononuclear cell counts in lamina propria differed significantly between subjects with and without SIBO, irrespective of the nature of the overgrowth flora. IEL counts were significantly higher than in culture-negative subjects only when the overgrowth flora included colonic-type bacteria. Even then, IEL counts were within a range currently considered normal. A significant, inverse correlation between advancing age and IEL counts became apparent after adjusting for the effect of SIBO of colonic-type flora. CONCLUSIONS: SIBO of oropharyngeal- and colonic-type flora are associated with differing disturbances of local duodenal mucosa. Nonetheless, these would not be readily apparent during routine histological assessment. Old age independently influences duodenal IEL counts.

Bacterial Infections↗
PubMed2001

Active matrilysin (MMP-7) in human pterygia: potential role in angiogenesis.

PURPOSE: Pterygia are invasive, proliferative fibrovascular growths, with the matrix metalloproteinase (MMP) family of enzymes strongly implicated in the pathogenesis of these lesions. The purpose of this study was to determine the cellular distribution and activation status of matrilysin (MMP-7) in pterygia. METHODS: Resected pterygia (n = 8) and normal conjunctiva (n = 8) were sectioned and analyzed immunohistochemically with two different epitope-specific anti-MMP-7 monoclonal antibodies (Abs) which differentiate pro- and active MMP-7. The specificity of each Ab was confirmed by Western blot analysis of p-aminophenylmercuric acetate (APMA)-activated and latent recombinant MMP-7. Pterygia (n = 4) and autologous normal conjunctiva (n = 4) were placed in organ culture to determine the activation status of secreted MMP-7. RESULTS: Precursor and active forms of MMP-7 were detected in epithelial cells from both pterygia and normal conjunctiva. Intense immunoreactivity for pro- and active MMP-7 was also observed in the pterygium vasculature, but was essentially absent from conjunctival vessels. Pro-MMP-7 was also identified in the epithelial basement membrane and associated with matrix components in pterygia. The 141-7B2 Ab reacted with the 30-kDa latent MMP-7, and the IM47L Ab precipitated a 19-kDa active enzyme, thus confirming the differential specificity of each Ab. Pro- and active MMP-7 were increased 1.4- and 2.7-fold, respectively, in the supernatants from organ-cultured pterygia compared with conjunctiva. CONCLUSIONS: This study is the first to specifically localize an active MMP species in pterygia and strengthens the hypothesis that these enzymes are involved in the pathogenesis of this disease. The data also suggest that MMP-7 may play a significant role in the angiogenesis that characterizes this lesion. Future studies will be directed at determining whether targeting MMP activity may be useful for treatment of pterygia.

Adult↗
PubMed2000

Screening for prolonged fatigue syndromes: validation of the SOFA scale.

BACKGROUND: The identification of syndromes characterised by persistent and disabling mental and/or physical fatigue is of renewed interest in psychiatric epidemiology. This report details the development of two specific instruments: the SOFA/CFS for identification of patients with chronic fatigue syndrome (CFS) in specialist clinics and the SOFA/GP for identification of prolonged fatigue syndromes (PFS) in community and primary care settings. METHODS: Patients with clinical diagnoses of CFS (n = 770) and consecutive attenders at primary care (n = 1593) completed various self-report questionnaires to assess severity of current fatigue-related symptoms and other common somatic and psychological symptoms. Quality receiver operating characteristic curves were used to derive appropriate cut-off scores for each of the instruments. Comparisons with other self-report measures of anxiety, depression and somatic distress are noted. Various multivariate statistical modelling techniques [latent class analysis (LCA), longitudinal LCA] were utilised to define the key features of PFS and describe its longitudinal characteristics. RESULTS: The SOFA/CFS instrument performs well in specialist samples likely to contain a high proportion of patients with CFS disorders. Cut-off scores of either 1/2 or 2/3 can be used, depending on whether the investigators wish to preferentially emphasise false-negatives or false-positives. Patients from these settings can be thought of as consisting not only of those with a large number of unexplained medical symptoms, but also those with rather specific musculoskeletal and pain syndromes. The SOFA/GP instrument has potential cut-off scores of 1/2 or 2/3, with the latter preferred as it actively excludes all non-PFS cases (sensitivity = 81%, specificity = 100%). Patients with these syndromes in the community represent broader sets of underlying classes, with the emergence of not only musculoskeletal and multisymptomatic disorders, but also persons characterised by significant cognitive subjective impairment. Twelve-month longitudinal analyses of the primary care sample indicated that the underlying class structure was preserved over time. Comparisons with other measures of psychopathology indicated the relative independence of these constructs from conventional notions of anxiety and depression. CONCLUSIONS: The SOFA/GP instrument (which is considerably modified from the SOFA/CFS in terms of anchor points for severity and chronicity) is preferred for screening in primary care and community settings. Patients with PFS and CFS present a range of psychopathology that differs in its underlying structure, cross-sectionally and longitudinally, from coventional notions of anxiety and depression.

Adult↗
PubMed2000

Intravenous pulse methylprednisolone in the treatment of uveitis associated with multiple sclerosis.

PURPOSE: To demonstrate the safety and effectiveness of intravenous methylprednisolone (IVMP) in the treatment of uveitis in association with multiple sclerosis (MS). METHODS: Uveitis is an unusual manifestation of MS that may be severe, chronic and require systemic immunosuppression therapy. High-dose IVMP has previously been shown to be effective in the treatment of inflammatory eye disease and MS. Eight episodes of uveitis in five patients with MS were treated over a 10-year period in an open, uncontrolled trial. Two patients had chronic anterior uveitis, one patient had bilateral panuveitis and two patients had intermediate uveitis. RESULTS: All patients responded to IVMP with evidence of a decrease in intraocular inflammatory activity and improved visual acuity (VA) within 2 weeks of commencing treatment. There were no severe ocular or systemic steroid side effects. CONCLUSIONS: Intravenous methylprednisolone is an effective, well-tolerated form of therapy for uveitis in patients with MS.

Adult↗