26
|
Stirling FR, Evans TJ. Effects of the type III secreted pseudomonal toxin ExoS in the yeast Saccharomyces cerevisiae. MICROBIOLOGY-SGM 2006; 152:2273-2285. [PMID: 16849794 DOI: 10.1099/mic.0.28831-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pseudomonas aeruginosa secretes a number of toxins by a type III system, and these are important in virulence. One of them, ExoS, is a bifunctional toxin, with a GTPase-activating protein domain, as well as ADP ribosyltransferase (ADPRT) activity. These two domains have numerous potential cellular targets, but the overall mechanism of ExoS action remains unclear. The effects of ExoS in a simple eukaryotic system, the yeast Saccharomyces cerevisiae, using a tetracycline-regulated expression system were studied. This system allowed controlled expression of ExoS in yeast, which was not possible using a galactose-induced system. ExoS was found to be an extremely potent inhibitor of yeast growth, and to be largely dependent on the activity of its ADPRT domain. ExoS produced a dramatic alteration in actin distribution, with the appearance of large aggregates of cortical actin, and thickened disorganized cables, entirely dependent on the ADPRT domain. This phenotype is suggestive of actin stabilization, which was verified by showing that the cortical aggregates of actin induced by ExoS were resistant to treatment with latrunculin A, an agent that prevents actin polymerization. ExoS increased the numbers of mating projections produced following growth arrest with mating pheromone, and prevented subsequent DNA replication, an effect that is again dependent on the ADPRT domain. Following pheromone removal, ExoS produced altered development of the mating projections, which became elongated with a swollen bud-like tip. These results suggest alternative pathways for ExoS action in eukaryotic cells that may result from activation of small GTPases, and this yeast expression system is well suited to explore these pathways.
Collapse
|
27
|
Stirling FR, Cuzick A, Kelly SM, Oxley D, Evans TJ. Eukaryotic localization, activation and ubiquitinylation of a bacterial type III secreted toxin. Cell Microbiol 2006; 8:1294-309. [PMID: 16882033 DOI: 10.1111/j.1462-5822.2006.00710.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Type III secretion is a widespread method whereby Gram-negative bacteria introduce toxins into eukaryotic cells. These toxins mimic or subvert a normal cellular process by interacting with a specific target, although how toxins reach their site of action is unclear. We set out to investigate the intracellular localization of a type III toxin of Pseudomonas aeruginosa called ExoU, which has phospholipase activity and requires a eukaryotic factor for activity. We found that ExoU is localized to the plasma membrane and undergoes modification within the cell by addition of two ubiquitin molecules at lysine-178. A region of five amino acids at position 679-683 near the C-terminus of the ExoU protein controls both membrane localization and ubiquitinylation. Site-directed mutagenesis identified a tryptophan at position 681 as crucial for these effects. We found that the same region at position 679-683 was also required for cell toxicity produced by ExoU as well as in vitro phospholipase activity. Localization of the phospholipase ExoU to the plasma membrane is thus required for activation and allows efficient utilization of adjacent substrate phospholipids.
Collapse
|
28
|
Ganjam VK, Evans TJ. Equine endometrial fibrosis correlates with 11beta-HSD2, TGF-beta1 and ACE activities. Mol Cell Endocrinol 2006; 248:104-8. [PMID: 16406651 DOI: 10.1016/j.mce.2005.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Endometrial periglandular fibrosis (EPF) contributes to embryonic and fetal loss in mares. Equine EPF correlates inversely with conception and successful gestation. In the modified Kenney endometrial biopsy classification system, EPF categories I, IIA, IIB, and III correspond to minimal, mild, moderate, and severe fibrosis (+/-inflammation), respectively. Paraffin sections of biopsy specimens were stained with H&E, and picrosirius red (specific for fibrillar collagens types I and III), to determine %EPCVF. Endometrial ACE-binding activity, TGF-beta1 and 11beta-HSD2 activities were also measured. Ultrastructural changes in EPF categories IIB and III endometria strongly suggested myofibroblastic transformation. ACE-binding activity was highest in EPF category IIB; however, endometrial TGF-beta1 and 11beta-HSD2 activities were significantly correlated to the severity of EPF (P<0.05). We conclude that, locally generated angiotensin II initiates the expression of TGF-beta1 resulting in myofibroblastic transformation. 11Beta-HSD2 in concert appears to modulate the severity of endometrial fibrosis.
Collapse
|
29
|
Davis RJ, Page KJ, Dos Santos Cruz GJ, Harmer DW, Munday PW, Williams SJ, Picot J, Evans TJ, Sheldrick RL, Coleman RA, Clark KL. Expression and Functions of the Duodenal Peptide Secretin and its Receptor in Human Lung. Am J Respir Cell Mol Biol 2004; 31:302-8. [PMID: 15191914 DOI: 10.1165/rcmb.2004-0035oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The physiological role of the duodenal peptide secretin is as a potent stimulant of electrolyte and water movement in pancreatic and biliary epithelium, via activation of G protein-coupled secretin receptors (hSCTR). However, the distribution and potential function of hSCTR in human lung has not previously been addressed. Using real-time quantitative reverse transcriptase-polymerase chain reaction profiling, in situ hybridization, and immunohistochemistry, we demonstrated that the hSCTR is abundantly expressed within the distal regions of human lung (tertiary bronchus and parenchyma), with negligible expression detected in more proximal regions (trachea, primary, and secondary bronchus). Expression was observed predominantly on the basolateral membrane of the bronchial epithelial layer, with some expression also observed in bronchial smooth muscle. In primary cultures of human tertiary bronchial epithelial cells, secretin was demonstrated to potently stimulate channel-mediated Cl- efflux in a concentration-dependent manner. Secretin was also shown to cause concentration-dependent relaxation of human tertiary bronchial smooth muscle. In summary, these data demonstrate that secretin receptors are present in human lung, and that activation of these receptors with human secretin potently stimulates concentration-dependent Cl- efflux from bronchial epithelial cells and bronchorelaxation.
Collapse
|
30
|
Schroder L, Basta NT, Casteel SW, Evans TJ, Payton ME, Si J. Validation of the in vitro gastrointestinal (IVG) method to estimate relative bioavailable lead in contaminated soils. JOURNAL OF ENVIRONMENTAL QUALITY 2004; 33:513-521. [PMID: 15074802 DOI: 10.2134/jeq2004.5130] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effect of the dosing vehicle (e.g., dough) on the ability of an in vitro gastrointestinal (IVG) method to predict relative bioavailable Pb associated with soil ingestion was evaluated. Bioaccessible Pb determined by the IVG method was compared with relative bioavailable Pb measured from dosing trials using juvenile swine for 18 contaminated soils ranging from 1270 to 14200 mg Pb kg(-1). Bioaccessible Pb was measured in the IVG gastric extraction (GE) and intestinal extraction (IE) solutions. Mean bioaccessible Pb values were 32.2% for GE without dough, 23.0% for GE with dough, 1.06% for IE without dough, and 0.56% for IE with dough. It is possible that phytic acid associated with the dough addition decreased bioaccessible Pb. In vivo relative bioavailable Pb ranges for different swine tissues were 1 to 87% for blood, 0 to 110% for liver, 1 to 124% for kidney, and 0.04 to 94% for bone. Strong linear relationships between IVG GE Pb with dough (r > 0.76, P < 0.0002), IVG IE Pb with dough (r > 0.56, P < 0.015), and IVG GE Pb without dough (r > 0.81, P < 0.0001) and in vivo bioavailable Pb as estimated with blood, kidney, liver, and bone were found. Inexpensive in vitro methods may be useful in providing an estimate of the variability in relative bioavailable Pb at a single study site. The IVG method can be used to estimate relative bioavailable Pb, As, and Cd in contaminated soil.
Collapse
|
31
|
Miller MA, Kottler SJ, Ramos-Vara JA, Johnson PJ, Ganjam VK, Evans TJ. 3-methylindole induces transient olfactory mucosal injury in ponies. Vet Pathol 2003; 40:363-70. [PMID: 12824507 DOI: 10.1354/vp.40-4-363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Response to 3-methylindole (3MI) varies among species. Mice recover from 3MI-induced bronchiolar epithelial injury but sustain persistent olfactory mucosal injury with scarring and epithelial metaplasia. In contrast, 3MI induces obliterative bronchiolitis in horses and ponies, but olfactory mucosal injury has not been reported. To evaluate the effect of 3MI on equine olfactory mucosa, ponies were dosed orally with 100 mg 3MI/kg (n = 9) or corn oil vehicle (n = 6). All ponies treated with 3MI developed obliterative bronchiolitis with mild olfactory injury. By 3 days after 3MI dosing, olfactory epithelium appeared disorganized with decreased and uneven surface height and scalloping of the basement membrane zone. Epithelial cells of Bowman's glands were hypertrophic. Proliferation of olfactory epithelium and Bowman's glands was supported by an increased mitotic index and positive immunohistochemical staining for proliferating cell nuclear antigen as compared with controls. The activity of 11beta-hydroxysteroid dehydrogenase, an olfactory mucosal cytosolic enzyme localized to sustentacular and Bowman's glandular epithelial cells, was concurrently decreased. By 9 days postdosing, olfactory mucosal lesions had lessened. Results indicate that 3MI transiently injures equine olfactory mucosa without the extensive necrosis, scarring, or metaplasia seen in murine olfactory mucosa or in equine bronchiolar epithelium.
Collapse
|
32
|
Truong TN, Evans TJ. Direct ab Initio Dynamics Calculations of Thermal Rate Constants and Kinetic Isotope Effects for the H + H2O .tautm. OH + H2 Reaction. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100089a032] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
33
|
Webb JL, Harvey MW, Holden DW, Evans TJ. Macrophage nitric oxide synthase associates with cortical actin but is not recruited to phagosomes. Infect Immun 2001; 69:6391-400. [PMID: 11553583 PMCID: PMC98774 DOI: 10.1128/iai.69.10.6391-6400.2001] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Nitric oxide (NO) produced from inducible NO synthase (iNOS) is an important component of host defense against intracellular pathogens. To understand how phagocytes deliver NO to ingested microorganisms while avoiding cytotoxicity, we set out to study the subcellular localization of iNOS within macrophages following phagocytosis. Confocal microscopy of immunostained cells showed that iNOS was located not only diffusely within cytoplasm but also in vesicles, as well as immediately adjacent to the peripheral cell membrane. This peripheral iNOS colocalized with the cortical actin cytoskeleton and was removed by the actin-depolymerizing drug cytochalasin B. Biochemical fractionation of RAW 264 macrophages showed that 32.75% (+/-5.11%; n = 3) of iNOS was present in a particulate fraction, which cosedimented with low-density cellular vesicles. Following phagocytosis of latex beads, zymosan, immunoglobulin G-coated beads, or complement-coated zymosan, submembranous cortical iNOS was not recruited to phagosomes, nor was there any relocalization of intracellular iNOS. Similarly, following phagocytosis of Salmonella enterica serovar Typhimurium there was no recruitment of iNOS to the Salmonella vacuole at any stage after internalization. NO mediated significant killing of intracellular S. enterica serovar Typhimurium in RAW macrophages treated with lipopolysaccharide and gamma interferon; this was evident 4 h after infection. Although not recruited to phagosomes, iNOS association with the submembranous cortical actin cytoskeleton is ideally suited to deliver NO to microbes in contact with the cell surface and may contribute to early killing of ingested Salmonella.
Collapse
|
34
|
Redington AE, Meng QH, Springall DR, Evans TJ, Créminon C, Maclouf J, Holgate ST, Howarth PH, Polak JM. Increased expression of inducible nitric oxide synthase and cyclo-oxygenase-2 in the airway epithelium of asthmatic subjects and regulation by corticosteroid treatment. Thorax 2001; 56:351-7. [PMID: 11312402 PMCID: PMC1746058 DOI: 10.1136/thorax.56.5.351] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Nitric oxide (NO) and prostanoids are mediators of vascular and bronchial tone that are postulated to be involved in asthma. Increased levels of both are found in asthmatic subjects and are synthesised by enzymes that have cytokine inducible forms: inducible NO synthase (iNOS) and cyclo-oxygenase-2 (COX-2), respectively. We hypothesised that the in vivo expression of iNOS and COX-2 in the airways would be increased in asthma, and that these cytokine inducible enzymes may represent targets for regulation by corticosteroid treatment. METHODS Bronchial biopsy specimens were obtained from three groups of subjects: atopic asthmatics treated with beta(2) agonists alone (n=7), atopic asthmatics additionally receiving regular treatment with corticosteroids (n=8), and non-asthmatic control subjects (n=10). Expression of iNOS and COX-2 mRNA and immunoreactive protein was studied using in situ hybridisation and quantitative immunohistochemistry. RESULTS Immunoreactivity and the hybridisation signal for iNOS and COX-2 were mainly localised in the airway epithelium. The proportion of epithelium immunostained was significantly greater in the non-steroid treated asthmatic subjects (iNOS 8.6 (1.8)%; COX-2 26.3 (4.6)%) than either the steroid treated asthmatics (iNOS 3.4 (1.0)%, p=0.009; COX-2 13.0 (0.6)%, p=0.0015) or the non-asthmatic controls (iNOS 4.2 (0.9)%, p=0.018; COX-2 11.6 (0.6)%, p=0.0003). Similarly, the hybridisation signal was stronger in the non-steroid treated group of asthmatic subjects than in the other two groups. CONCLUSIONS These findings highlight the potential role of the airway epithelium both as a contributor to the inflammatory process in asthma and as a target for inhaled corticosteroid treatment in this disease.
Collapse
|
35
|
Webb JL, Polak JM, Evans TJ. Effect of adhesion on inducible nitric oxide synthase (iNOS) production in purified human neutrophils. Clin Exp Immunol 2001; 123:42-8. [PMID: 11167996 PMCID: PMC1905968 DOI: 10.1046/j.1365-2249.2001.01402.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The production of nitric oxide (NO) within neutrophils is an important element of the innate immune response. We have previously shown that cytokines (IL-1alpha, tumour necrosis factor-alpha and interferon-gamma) induce human neutrophils in buffy coat preparations to produce iNOS. In order to define better the exact requirements for iNOS production within human neutrophils, we have studied the conditions needed for the production of iNOS in purified neutrophils. In contrast to buffy coat preparations, purified neutrophils in suspension did not produce an increase in iNOS following addition of cytokines. However, when purified neutrophils were allowed to adhere to glass surfaces either uncoated or coated with fetal calf serum (FCS), plasma, fibronectin or laminin, there was an increase in the percentage of iNOS-positive cells. The addition of cytokines during adhesion of these cells increased this proportion further. This was most marked for glass alone and FCS-coated glass on which the proportion of iNOS-positive cells increased to 22.7% and 35.5%, respectively, a significant increase compared with cytokine-treated neutrophils in suspension. Neither transmigration through activated endothelial monolayers nor the addition of soluble intercellular adhesion molecule-1 to purified neutrophil suspensions increased the percentage of iNOS-positive cells following cytokine stimulation. Adhesion of neutrophils to surfaces coated with IgG or complement also failed to increase cytokine-induced iNOS production. We conclude that iNOS production in human neutrophils requires not only cytokine stimulation, but also additional stimuli from adhesion to a surface.
Collapse
|
36
|
Croft NM, Howatson AG, Ling SC, Nairn L, Evans TJ, Weaver LT. Microvillous inclusion disease: an evolving condition. J Pediatr Gastroenterol Nutr 2000; 31:185-9. [PMID: 10941974 DOI: 10.1097/00005176-200008000-00019] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
|
37
|
Abstract
Tumor necrosis factor (TNF) is a central cytokine in the pathogenesis of septic shock and other inflammatory states. Assay by immunoassay is convenient, but, because of circulating soluble receptors, does not accurately reflect biological activity of the cytokine. This article describes how to perform a bioassay for TNF, using its cytopathic effect on the murine cell line L929. By suitable manipulation, the assay can determine the two different forms of TNF, alpha and beta.
Collapse
|
38
|
Meng QH, Polak JM, Edgar AJ, Chacon MR, Evans TJ, Gruenert DC, Bishop AE. Neutrophils enhance expression of inducible nitric oxide synthase in human normal but not cystic fibrosis bronchial epithelial cells. J Pathol 2000; 190:126-32. [PMID: 10657009 DOI: 10.1002/(sici)1096-9896(200002)190:2<126::aid-path500>3.0.co;2-#] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The bronchial epithelium in cystic fibrosis (CF) expresses very low levels of the inducible form of nitric oxide synthase (iNOS). The product of iNOS, nitric oxide (NO), mediates anti-microbial effects and can reduce neutrophil sequestration in the lung. Heavy neutrophilic infiltration of the pulmonary epithelium is a major feature of the end-stage CF lung. This study hypothesized that the system whereby the pulmonary epithelium protects itself against exaggerated neutrophilic infiltration by producing NO is compromised in CF. Human neutrophils were activated by incubation with cytokines, added to monolayers of normal (16HBE14o-) and CF (CFBE41o-) bronchial epithelial cells and co-cultured for up to 72 h. Marked up-regulation of iNOS protein expression was seen in normal bronchial epithelial cells following neutrophil co-culture but the CF cells showed a significantly smaller increase (p<0.001). To determine whether the relative lack of protein was due to a defect in translation, RT-PCR of iNOS mRNA was carried out and a pattern of mRNA expression was seen paralleling that of the protein. The reduced production of NO by CF compared with normal epithelium was shown by the presence of significantly (p<0.001) less accumulated nitrites in medium after co-culture with neutrophils. In summary, this study shows that the normal production of NO by bronchial epithelium in response to contact with neutrophils is lacking in CF. As NO has been shown to oppose neutrophil sequestration, its relative lack in CF may underlie the heavy neutrophilic infiltration that characterizes the disease.
Collapse
|
39
|
Gibson J, Neilly JB, Wray AP, Evans TJ, MacKenzie JR, McKillop JH. 99Tcm-HMPAO leucocyte labelling in orofacial granulomatosis and gastrointestinal Crohn's disease in childhood and early adulthood. Nucl Med Commun 2000; 21:155-8. [PMID: 10758610 DOI: 10.1097/00006231-200002000-00006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Orofacial granulomatosis is a granulomatous inflammatory disorder, affecting the soft tissues of the face and mouth. The predominant feature is disfiguring lip swelling. Patients with this condition may be exhibiting a Type IV hypersensitivity reaction to dietary or environmental allergens, or these may be the orofacial manifestations of underlying gastrointestinal Crohn's disease. The results of 99Tcm-HMPAO leucocyte labelling of the gastrointestinal tract in 14 patients with orofacial granulomatosis and 15 patients with known gastrointestinal Crohn's disease are presented, indicating that this is a useful and non-invasive screening test for the identification of gastrointestinal Crohn's disease in paediatric and young adult patients presenting with orofacial granulomatosis.
Collapse
|
40
|
Evans TJ, Ganjam VK, Miller MA, Niswender KD, Krause WJ, Youngquist RS. Relationship between the degree of endometrial periglandular fibrosis and the presence of angiotensin-converting enzyme in the equine endometrium. JOURNAL OF REPRODUCTION AND FERTILITY. SUPPLEMENT 2000:393-398. [PMID: 20681151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Endometrial periglandular fibrosis (EPF) has been proposed as a possible aetiology for equine embryonic and fetal loss. However, the pathophysiology of EPF is not well understood. Angiotensin-converting enzyme (ACE) is found in macrophages, endothelium (during angiogenesis) and myofibroblasts at sites of fibrosis in the heart, kidneys, liver and skin in several species. An increase in local tissue ACE-binding activity appears to be a critical event in the initiation and progression of fibrosis in these tissues. The aim of this study was to investigate the correlation between ACE activity in the equine endometrium and the degree of EPF, as determined by histological evaluation and morphometry based on a collagen-specific stain. ACE-binding activity values were significantly higher in the endometrial samples with moderate EPF (modified Kenney EPF category IIB) compared with endometria in all other categories. Ultrastructurally, the fibroblasts surrounding the glandular basal laminae in modified Kenney EPF category IIB and III endometria were undergoing myofibroblastic transformation-like changes. These observations indicate a possible link between ACE activity and the onset of EPF in mares.
Collapse
|
41
|
Bland RM, Evans TJ, Raine P, Weaver LT. Inflammatory bowel disease in Scottish children. HEALTH BULLETIN 1999; 57:365-73. [PMID: 12811868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Most children with inflammatory bowel disease (IBD) require specialist care in a tertiary medical centre. The records of 105 children with IBD who presented to the Royal Hospital for Sick Children, Glasgow between 1976 and 1995 were studied retrospectively. Fifty seven children and Crohn's disease (CD) (median age of presentation 7.9 years) and 48 had ulcerative colitis (UC) (median age of presentation 8.7 years). The number with CD doubled in the decade 1986-95 compared to 1975-85. 23% with CD and 13% with UC developed symptoms before the age of five years. Median time to diagnosis from symptom onset was 45.8 weeks for CD and 12.7 weeks for UC. Histological diagnosis was obtained in all children. The mainstay of treatment was aminosalicylates, and few children underwent surgery (CD 26%, UC 10%). Thirty percent with CD and 23% with UC had no relapses in the study period, and only one child with UC died. Growth was poorly recorded. The majority of children with CD and over 50% with UC had a height-for-age Z score below zero.
Collapse
|
42
|
Amarri S, Harding M, Coward WA, Evans TJ, Weaver LT. 13C and H2 breath tests to study extent and site of starch digestion in children with cystic fibrosis. J Pediatr Gastroenterol Nutr 1999; 29:327-31. [PMID: 10468000 DOI: 10.1097/00005176-199909000-00016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND Starch is an important source of energy for children with cystic fibrosis, but little is known about their capacity to digest it. METHODS A 13C breath test was used to measure starch digestion and oxidation in 16 children with cystic fibrosis (median [range] age, 7.9 [4-15] years; 7 girls, 9 boys) and 5 normal healthy control subjects (median age, 8.3 [7-13] years; 3 girls, 2 boys). A test meal of 13C flour and lactulose was consumed and breath samples were obtained half-hourly thereafter for 6 hours to measure 13C enrichment by isotope ratio mass spectrometry and H2 by electrochemistry. The test was repeated on 10 children with cystic fibrosis when they were taking pancreatic supplements. RESULTS The median (range) cumulative percentage 13C dose recovery (cPDR), was 35% (18-52%) in control subjects, 18% (9-33%) in children with cystic fibrosis without enzymes, and 29% (22-51%) in those with pancreatic supplements. cPDR differed significantly between healthy control subjects and children with cystic fibrosis without enzymes (p = 0.01) and between children with cystic fibrosis with and without enzymes (p < 0.0001), but there was no difference between control subjects and children with cystic fibrosis taking enzymes (p = 0.5). Eight children with cystic fibrosis had a cPDR within control range, and in six there was a second peak in 13CO2 enrichment coincident with an increase in H2. CONCLUSIONS Starch digestion and oxidation are diminished in children with cystic fibrosis, but pancreatic enzymes restored them to near normal levels. A second peak in 13CO2 enrichment, suggestive of colonic starch fermentation was absent in healthy children, but present in some children with cystic fibrosis and abolished by pancreatic enzymes.
Collapse
|
43
|
Ling SC, Wilkinson JD, Hollman AS, McColl J, Evans TJ, Paton JY. The evolution of liver disease in cystic fibrosis. Arch Dis Child 1999; 81:129-32. [PMID: 10490519 PMCID: PMC1718033 DOI: 10.1136/adc.81.2.129] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To describe prospectively the evolution of liver abnormalities in cystic fibrosis (CF), and to assess their impact on nutritional status. STUDY DESIGN 124 children (61 boys) with CF (median age, 5.4 years; range, 0.1-13.9) were followed longitudinally for a median of four years. Annual clinical examination, biochemistry, and ultrasound assessment were performed. Chrispin-Norman score, anthropometry, and bacterial colonisation of airway secretions were measured at each assessment. RESULTS At initial assessment, 45% of the patients had no liver abnormalities, 42% had biochemical abnormality, 35% ultrasound abnormality, and 6% had clinical abnormality of the liver. In this cross sectional analysis, abnormal biochemistry was present in 40% of children with ultrasound or clinical abnormalities, but when longitudinal follow up data were analysed, abnormal biochemistry preceded or coincided with abnormal ultrasound or clinical hepatosplenomegaly in three quarters of 53 children developing new abnormalities. Eighty four of 124 children (68%) showed ultrasound or clinical evidence of liver abnormality at some point during the four years of follow up. No association was found between liver disease and nutritional status. CONCLUSIONS Hepatic abnormality was common in this group of children with CF, was often predicted by intermittent biochemical abnormalities, and was not associated with deterioration in nutritional status.
Collapse
|
44
|
Reilly JJ, Evans TJ, Wilkinson J, Paton JY. Adequacy of clinical formulae for estimation of energy requirements in children with cystic fibrosis. Arch Dis Child 1999; 81:120-4. [PMID: 10490516 PMCID: PMC1718005 DOI: 10.1136/adc.81.2.120] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Two clinical formulae (CF conference formula and estimation based on 120% of average requirement for energy) have been recommended for the estimation of energy requirements in cystic fibrosis but their accuracy is unknown. AIM To compare the accuracy of estimates of energy requirement derived from the two formulae. METHODS Energy requirement, defined as total daily energy expenditure, was measured using the doubly labelled water method in 15 patients (six girls, nine boys; mean (SD) age, 10.0 (2.4) years) who were well and clinically stable. The accuracy of the formulae was assessed using calculation of biases and limits of agreement relative to measured energy requirement. RESULTS Estimates from the CF conference formula were lower than measured values (mean paired difference, 0.52 MJ/day; 95% confidence interval (CI), -1.10 to 0. 10), but this bias was not significant, and was smaller than that from the alternative formula (mean paired difference, 0.77 MJ/day; 95% CI, -0.20 to 1.74). Limits of agreement relative to measured total daily energy expenditure were narrower for the CF conference formula (-2.72 to 1.68 MJ/day) than for that based on 120% of estimated average requirement (-2.75 to 4.29 MJ/day), but with both formulae errors in estimation at the individual level were large. CONCLUSIONS The CF conference formula offers improved prediction of energy requirements, but the accuracy of both formulae at the individual level is not sufficiently good for clinical purposes.
Collapse
|
45
|
Reilly JJ, Ralston JM, Paton JY, Edwards CA, Weaver LT, Wilkinson J, Evans TJ. Energy balance during acute respiratory exacerbations in children with cystic fibrosis. Eur Respir J 1999; 13:804-9. [PMID: 10362044 DOI: 10.1034/j.1399-3003.1999.13d18.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Acute respiratory exacerbations have been proposed to contribute to the negative energy balance which causes undernutrition in cystic fibrosis. However, no studies have measured their effect on all components of energy balance. The aim of this study was to measure the effect of an acute respiratory exacerbation on energy balance. Fourteen children (six females, eight males, mean+/-SD age 9.9+/-2.4 yrs) were studied when well and during the course of an acute respiratory exacerbation treated with intravenous antimicrobial therapy. The total energy expenditure was measured using the doubly-labelled water method, resting energy expenditure by ventilated hood indirect calorimetry, energy intake by household measures records, and fat malabsorption from measurements of dietary fat intake and faecal fat output. The exacerbation was associated with a significant reduction in energy intake (mean paired difference 47 kJ x kg of body weight(-1) x day(-1), p<0.01). Changes in fat malabsorption and resting energy expenditure were negligible. The absence of significant changes in body weight and composition, together with the trend towards lower total energy expenditure, suggested no marked negative energy balance during the exacerbation. In conclusion, treatment of acute respiratory exacerbation with intravenous antimicrobial therapy represents a relatively minor challenge to energy balance and nutritional status in children with cystic fibrosis.
Collapse
|
46
|
Baker CS, Hall RJ, Evans TJ, Pomerance A, Maclouf J, Creminon C, Yacoub MH, Polak JM. Cyclooxygenase-2 is widely expressed in atherosclerotic lesions affecting native and transplanted human coronary arteries and colocalizes with inducible nitric oxide synthase and nitrotyrosine particularly in macrophages. Arterioscler Thromb Vasc Biol 1999; 19:646-55. [PMID: 10073969 DOI: 10.1161/01.atv.19.3.646] [Citation(s) in RCA: 201] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inflammation appears to have a major role in the development of atherosclerotic lesions affecting native and transplanted coronary arteries. The subsequent risk of plaque rupture and acute ischemic events correlates with the degree of inflammation and may be modified by aspirin, an anti-inflammatory cyclooxygenase inhibitor. Cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) are involved in the inflammatory response via the rapid and exaggerated production of prostanoids and nitric oxide, both of which may have proatherosclerotic effects. These effects may be mediated by the formation of peroxynitrite in the case of nitric oxide and involve "cross talk" between the two enzyme systems. This study aimed to investigate native and transplant atherosclerosis for the presence and distribution of Cox-2 and iNOS. Immunocytochemical studies were performed on atherosclerotic lesions from patients with native (n=12) and transplant (n=5) coronary disease by using antibodies to Cox-2, iNOS, and nitrotyrosine (an indicator of peroxynitrite production). Control tissue was obtained from unused donor hearts and at the time of autopsy. Cox-2 and iNOS colocalized predominantly in macrophages/foam cells in both types of atherosclerosis. Cox-2 expression was also detected in medial smooth muscle cells and endothelial cells, including those of the vasa vasorum. Nitrotyrosine was found in the same distribution as that of iNOS and was colocalized with Cox-2 in macrophages. Cox-2 and iNOS are coexpressed in native and transplant atherosclerosis, possibly allowing for interaction between the enzymes and suggesting an alternative mechanism for the benefits of aspirin via inhibition of Cox-2 activity.
Collapse
|
47
|
|
48
|
Evans TJ, Miller MA, Ganjam VK, Niswender KD, Ellersieck MR, Krause WJ, Youngquist RS. Morphometric analysis of endometrial periglandular fibrosis in mares. Am J Vet Res 1998; 59:1209-14. [PMID: 9781449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
OBJECTIVES To develop an objective, quantifiable assay for endometrial periglandular fibrosis (EPF) and correlate assay results with histologic and ultrastructural changes in equine endometrial biopsy specimens. SAMPLE POPULATION Endometrial biopsy specimens from 70 mares from 3 to 27 years old in estrus. PROCEDURE In a double-blinded study design, endometrial biopsy specimens were graded histologically (modified Kenney classification) for EPF and inflammation. Endometrial periglandular collagen volume fraction (%EPCVF) was determined by light microscopic image analysis of picrosirius red-stained sections. Specimens from selected mares were examined by transmission electron microscopy. RESULTS %EPCVF values varied significantly among the 4 modified Kenney EPF categories (I, IIA, IIB, and III) and increased with increasing age of mares. Morphologically, EPF consisted of concentric layers of transformed fibroblasts with myofibroblastic features and deposition of fibrillar collagen around unaltered glandular basal laminae. CONCLUSIONS AND CLINICAL RELEVANCE %EPCVF correlates well with morphologic changes in endometrial biopsy specimens. Determination of %EPCVF could be useful in evaluation and clinical management of subfertile mares and in investigations of the pathogenesis of EPF.
Collapse
|
49
|
Mason NA, Springall DR, Pomerance A, Evans TJ, Yacoub MH, Polak JM. Expression of inducible nitric oxide synthase and formation of peroxynitrite in posttransplant obliterative bronchiolitis. J Heart Lung Transplant 1998; 17:710-4. [PMID: 9703237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Obliterative bronchiolitis is characterized histologically by inflammation, epithelial cell damage and loss, fibrosis, and eventual obliteration of airways. Production of high levels of the potential cytotoxin nitric oxide by inducible nitric oxide synthase has been implicated in several inflammatory diseases. The damaging effects of nitric oxide are mediated by peroxynitrite, are formed from nitric oxide and superoxide, and can be demonstrated by the detection of nitrotyrosine. Our previous finding of high inducible nitric oxide synthase expression in inflamed airway epithelium led us to hypothesize that release of nitric oxide in obliterative bronchiolitis mediates the characteristic epithelial damage. METHODS Immunocytochemistry was carried out to seek expression of inducible nitric oxide synthase and nitrotyrosine in transplant samples from patients with obliterative bronchiolitis (n=10) and, as controls, unused donor lungs (n=5). RESULTS Inducible nitric oxide synthase was strongly expressed in the damaged airway epithelium in obliterative bronchiolitis and in inflammatory cells, where its distribution was matched by that of nitrotyrosine. Normal controls showed little or no immunoreactivity for any of the antigens studied. CONCLUSIONS Our findings suggest that nitric oxide may play a role in the pathogenesis of obliterative bronchiolitis and indicate that further work is essential to fully understand the processes and mechanisms involved.
Collapse
|
50
|
Evans TJ, Jones ML, Newcombe RG. Clinical comparison and performance perspective of three aligning arch wires. Am J Orthod Dentofacial Orthop 1998; 114:32-9. [PMID: 9674677 DOI: 10.1016/s0889-5406(98)70234-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVES To clinically evaluate three commonly used orthodontic tooth aligning arch wires: 016 x 022 inch active martensitic medium force nickel titanium, 016 x 022 inch graded force active martensitic nickel titanium, and 0.0155 inch multistrand stainless steel. DESIGN A prospective randomized clinical trial. DATA SOURCE Measured serial study casts of dental arches for 112 assigned arch wires from 56 consecutive patients. Analysis based on completed records for 98 arch wires and 51 patients. METHOD A consecutive sample of 56 patients requiring both upper and lower fixed appliance therapy were randomly allocated two different arch wires from a possible three under trial. Good quality impressions were taken of the dental arches at the designated serial stages of alignment (start, T0; 4 weeks, T4; 8 weeks, T8). The resultant casts were measured on a Reflex Microscope to record the change in individual tooth alignment both in three and two dimensions (horizontal plane only). RESULTS The measurement error was within acceptable limits (range, 0.05 to 0.09 mm) and showed no significant bias. ANOVA statistical models were fitted to the data to adjust for a number of variables. No significant difference in aligning capability (p > 0.05), in either two or three dimensions, was demonstrated between the three arch wires in the trial. CONCLUSION Heat activated nickel titanium arch wires failed to demonstrate a better performance than the cheaper multistrand stainless steel wires in this randomized clinical trial. The failure to demonstrate in vivo superiority at the clinical level may be due to the confounding effects of large variations in individual metabolic response. Alternatively, it may be that in routine clinical practice NiTi-type wires are not sufficiently deformed to allow their full superelastic properties to come in to play during initial alignment.
Collapse
|