ORCID Profile
0000-0003-2528-5586
Current Organisations
Flinders University
,
University of Kentucky
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Publisher: Oxford University Press (OUP)
Date: 10-1998
DOI: 10.1046/J.1365-2249.1998.00681.X
Abstract: Neutrophils are the predominant inflammatory cell in the lung tissues and airways in RSV infection, and can augment the epithelial cell damage induced by RSV. Neutrophil apoptosis has been suggested to be a mechanism to reduce the potential for tissue injury. The apoptosis of neutrophils from nasopharyngeal aspirates (NPA) (n = 19) and peripheral blood (PB) of infants with RSV bronchiolitis (n = 11) and PB from healthy controls (n = 9) was investigated. Monoclonal antibody against CD95 (Fas) and a binding protein Annexin V were used to determine the apoptosis of neutrophils. The expression of CD11b and CD18 on neutrophils was also detected with flow cytometry. The mean fluorescence intensity (MFI) of CD95 on neutrophils from RSV+ NPA was increased compared with cells from control PB (73·6 ± 7·6 versus 31·5 ± 4·3) the MFI of Annexin V, CD11b and CD18 on neutrophils from RSV+ NPA was up-regulated compared with cells from both control PB (105·3 ± 18·1 versus 11·8 ± 1·5 1683 ± 153·3 versus 841·1 ± 72·3 517 ± 50·5 versus 147 ± 8·7, respectively) and RSV+ PB (105·3 ± 18·1 versus 35·8 ± 4·1 1683 ± 153·3 versus 818 ± 141·2 517 ± 50·5 versus 260 ± 25·8, respectively). Furthermore, the percentage of neutrophils expressing Annexin V and the MFI of CD18 on neutrophils from RSV+ PB were increased compared with neutrophils from control PB. In addition, both CD11b (MFI) and CD18 (MFI) correlated with Annexin V (MFI) on neutrophils. We conclude that neutrophil apoptosis in RSV bronchiolitis is accelerated and CD11b/CD18 may play an important role in RSV infection by influencing neutrophil apoptosis.
Publisher: Wiley
Date: 12-2006
DOI: 10.1007/S11745-006-5059-9
Abstract: A protective association between breastfeeding and the development of bronchial asthma has been demonstrated. However, a mechanism remains unclear. FA present in human milk but rare in infant formula have been associated with marked immunological modulation as well as some indications of protection from asthma development. We examined the effect of in vitro manipulation of membrane phospholipid on the production of cytokines and prostaglandin (PG)E2 by respiratory epithelial cells (A549) in response to stimulation by mast cell mediators of allergic disease [histamine, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4 and IL-5]. DHA and CLA significantly decreased the production of IL-8 in response to stimulation by TNF-alpha [2907 +/- 970 (DHA) and 6471 +/- 1203 (CLA) vs. 12,287 +/- 2309 (control) pg/mL P < or = 0.05, mean +/- SEM], whereas both EPA and DHA reduced histamine-stimulated RANTES (regulation on activation, T cell-expressed and -secreted) production [2314 +/- 861 (EPA) and 877 +/- 326 (DHA) vs. 8526 +/- 1118 (control) pg/mL P < or = 0.03]. PGE2 released in response to histamine was decreased by n-3 [1305 +/- 399 (alpha-linolenic acid), 406 +/- 73 (EPA), and 265 +/- 32 (DHA) vs. 9324 +/- 3672 (control) pg/mL P < or = 0.05] and increased by n-6 [18,843 +/- 4439 (arachidonic acid) vs. 9324 +/- 3672 (control) pg/mL P = 0.02], with CLA producing a decrease of the same magnitude as DHA [553 +/- 126 (CLA) vs. 9324 +/- 3672 (control) pg/mL P = 0.03]. This study demonstrates the potential for immunological manipulation of the respiratory epithelium by FA in situ during allergic responses and suggests that further investigation into FA intervention in infants via human milk or supplemented infant formula, to prevent the development of allergic disease, may be worthwhile.
Publisher: Elsevier BV
Date: 03-2006
DOI: 10.1016/J.CYTO.2006.02.009
Abstract: Development of lymphocyte subpopulations and response to antigen exposure will be influenced by the limited ability of neonates to produce cytokines. In the case of cytokines such as interleukin (IL)-2 which are potent T lymphocyte regulators but poorly produced by newborn infants, the supply of cytokines through human milk could alleviate an immunological deficit and potentially aid the maturation of the immune system. We analysed human milk from 52 mothers (15-357 days postpartum) by ELISA to determine levels of aqueous IL-2, as well as production by human milk cells. IL-2 was detectable (>8 pg/mL) in the aqueous phase of 81% of all day 1 s les with no significant difference found in the mean concentration over 3 consecutive days. IL-2 was produced constitutively at detectable levels by 57% of milk cell s les and production was significantly increased by stimulation with Con A (380%). No correlation was found between aqueous and cellular IL-2, however there was a significant correlation between milk aqueous IL-2 and serum IL-2. This is the first report of IL-2 in the aqueous phase of human milk. A supply of exogenous IL-2 in human milk may provide the suckling infant with important immunological signals during a significant stage of T cell development.
Publisher: American Chemical Society (ACS)
Date: 30-08-2023
Publisher: Wiley
Date: 12-2000
DOI: 10.1046/J.1440-1754.2000.00565.X
Abstract: This paper provides specific guidelines on the management of tuberculosis infection and disease, covering general principles, recommended drug regimens and discuss the evidence to support these. It also covers use of corticosteroids, intermittent therapy, directly observed therapy and an approach to the management of a patient with drug-resistant tuberculosis.
Publisher: European Respiratory Society (ERS)
Date: 02-2000
DOI: 10.1034/J.1399-3003.2000.15B23.X
Abstract: Respiratory epithelium is both a target and an effector of airway inflammation. Adhesion molecules on epithelium play an important role in a variety of airway diseases. Respiratory syncytial virus (RSV) is the most important pathogen for airway diseases in infants. The expression of adhesion molecules on epithelium in RSV infection, however, is unclear. The expression of selected adhesion molecules and major histocompatibility complex (MHC) class I and II antigens on a human alveolar type II epithelial cell line (A549) infected with RSV was investigated by means of flow cytometry and immunocytochemistry. The results showed that intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were expressed on A549 cells at a low level. E-cadherin and MHC class I antigen were constitutively expressed on the cells. RSV infection of A549 cells significantly upregulated the expression of ICAM-1, VCAM-1 and MHC class I and II antigens on these cells. RSV infection also altered the expression of E-cadherin on A549 cells. Immunostaining showed that E-cadherin was mainly upregulated around or in RSV-induced giant cells. These data suggest that respiratory syncytial virus infection of respiratory epithelial cells enhances the expression of adhesion molecules and major histocompatibility complex antigens. These changes may play an important role in the pathophysiology of respiratory syncytial virus disease.
Publisher: Springer Science and Business Media LLC
Date: 21-10-2019
DOI: 10.1186/S12909-019-1829-Y
Abstract: Medical school selection decisions have consequences beyond graduation. With generally low attrition rates, most medical students become junior doctors. Universities are therefore not just selecting students into a medical course they are choosing the future medical workforce. Understanding the relationship between selection criteria and outcomes beyond the successful completion of a medical degree may inform approaches to student selection. A retrospective data matching study was conducted involving 39 interns employed by a South Australian local health network in 2017 who had originally entered Flinders University’s medical school through a graduate pathway. Student selection data were matched with internship workplace performance scores (measured by supervising consultants’ reports across five clinical rotations using a standardised assessment). Correlational analyses then examined associations between these two sets of variables. An overall selection rank (equal thirds of weighted Grade Point Average from a prior degree, a panel interview, and a national selection test) was moderately associated with all performance measures, accounting for up to 25% of variance. Both weighted Grade Point Average and the interview had multiple and mostly moderate correlations with performance. An increasing number of years taken to complete the course was associated with poorer workplace performance across multiple outcome measures (moderate to strong negative associations with 31 to 62% of shared variance), as was age to a lesser extent (7 to 14%). The national selection test contributed a single and small relationship accounting for 5% of variance with one outcome measure. Selection into medicine is a critical assessment given that most students become doctors. This study found multiple associations between selection scores and junior doctor workplace performance measures in the internship year, with weighted Grade Point Average from a prior degree and an interview appearing more important than the national selection test. Future collaborative research should map desired workplace performance outcomes to initial student selection and explore the impact of changes to selection which focus on assessment of these domains. The association between slower course progression and poorer workplace performance should also be examined.
Publisher: European Respiratory Society (ERS)
Date: 09-1998
DOI: 10.1183/09031936.98.12030612
Abstract: The mechanisms by which respiratory syncytial virus (RSV) infection induces bronchiolitis and airway disease are unclear. The presence of large numbers of polymorphonuclear leukocytes (PMN) in the airways of infants with RSV infection suggests a potential role of PMN in airway injury associated with RSV infection. To investigate the potential role of neutrophils in RSV bronchiolitis, human alveolar type II cells (A549 cells) were infected with different doses of RSV for 6-48 h. A 51Cr-releasing assay was used to measure PMN-induced damage and image analysis was used to determine PMN adhesion and detachment of epithelial cells. The results showed that RSV infection of epithelial cells enhanced PMN adherence in a dose- and time-dependent pattern, RSV infection alone could damage and detach epithelial cells to a limited extent and PMN significantly augmented RSV infection-induced damage and detachment of epithelial cells. These data suggest that respiratory syncytial virus infection of respiratory epithelial cells enhances neutrophil adhesion to the epithelium and that activated neutrophils augment the damage and detachment of epithelium infected with the virus. Polymorphonuclear leukocytes may contribute to the pathogenesis of respiratory syncytial virus airway disease by inducing epithelial damage and cell loss.
Publisher: Wiley
Date: 12-05-2016
DOI: 10.1111/CEA.12740
Abstract: Current peanut oral immunotherapy is h ered by frequent adverse events. It has been shown that boiling can reduce peanut allergenicity. Hypoallergenic peanut products have the potential to reduce treatment-related reactions during desensitization. To show that extended boiling (for up to 12 h) can progressively reduce peanut allergenicity while retaining T cell reactivity. Raw peanuts were boiled for half, 1, 2, 4 and 12 h in deionized water. After dehydration, boiled and raw peanuts were ground, defatted and soluble proteins extracted in PBS and cooking water (leachate) retained. SDS-PAGE, Western blot, inhibition ELISA, mass spectrometry and skin prick test were used to characterize changes to peanut allergens and human IgE reactivity. T cell responses to raw and boiled peanut extracts were determined by proliferation of CD4+/CD25+/CD134+ T cells in peanut-allergic and non-allergic in iduals. Extended boiling progressively reduced peanut allergenicity through a combination of leaching of allergens into cooking water, fragmentation of allergens and denaturation of conformational epitopes. Two-hour boiling led to an eightfold reduction in IgE binding capacity of boiled peanuts as determined by inhibition ELISA, while 12-h boiling led to a 19-fold reduction. Mass spectrometry revealed an increasing number of unique allergen peptides with longer boiling times. Raw, 2- and 12-h boiled peanut extracts were equivalent in their ability to stimulate T cell activation and proliferation. Progressive reduction in peanut allergenicity with extended boiling does not affect T cell reactivity. Boiled peanuts may be a candidate for oral immunotherapy.
Publisher: Wiley
Date: 02-08-2007
DOI: 10.1111/J.1399-3038.2007.00565.X
Abstract: Although epidemiological evidence is generally supportive of a causal association between respiratory syncytial virus (RSV) bronchiolitis during infancy and the development of persistent wheeze/asthma, if not allergy, the mechanism by which this occurs and an explanation for why all children do not succumb remains to be elucidated. Breast feeding has been found to confer a protective effect against respiratory infections such as RSV bronchiolitis and allergy however, again there is little direct evidence and no clear mechanism. In this study, we examined whether human milk immunomodulatory factors (cells, cytokines) change in response to clinically diagnosed, severe bronchiolitis in the recipient breast-fed infant. We examined milk from 36 breast feeding mothers of infants hospitalized with bronchiolitis and compared them with milk from 63 mothers of postpartum age-matched healthy controls. Milks from mothers of infants hospitalized with bronchiolitis had significantly greater numbers of viable cells when compared with the milks obtained from mothers of healthy infants (1.3 +/- 0.4 vs. 0.3 +/- 0.03 x 10(6) cells/ml, mean +/- s.e.m. p < or = 0.001). Further, the cells obtained from the mothers of infants hospitalized with bronchiolitis were found to produce a skewed cytokine profile ex vivo in response to stimulation by live RSV but not when cultured with a non-specific mitogen (concanavalin A). This study provides preliminary evidence for an immunological link between mothers and their breast-fed infants during severe respiratory infections as well as a possible contributing factor to the development of persistent wheeze in these infants.
Publisher: Wiley
Date: 10-2005
DOI: 10.1007/S11745-005-1463-4
Abstract: Infection with respiratory syncytial virus (RSV) results in substantial infant morbidity and has been associated with the subsequent development of childhood asthma. Inflammatory mediators produced by both the epithelium and tissue leukocytes during RSV infection stimulate the release of chemotactic factors by the respiratory epithelium and the subsequent influx of inflammatory cells, predominantly neutrophils. We investigated the production of inflammatory mediators [prostaglandin E2 (PGE2), interleukin (IL)-1beta, tumor necrosis factor alpha] and chemokines [IL-8, RANTES (regulation on activation, normal T cell expressed and secreted)] by alveolar epithelial cells in response to RSV infection. Infection of a human alveolar epithelial transformed cell line (A549 cells) with live RSV substantially increased production of PGE2, IL-8, and RANTES. By altering cell membrane FA through incorporation of the long-chain PUFA (LCPUFA) arachidonic acid, EPA, and DHA, we were subsequently able to significantly modulate PGE2 production by the infected epithelium. Because of the dynamic nature of the effects of PGE2 on lung function, regulation of this prostaglandin during RSV infection by n-3 LCPUFA has the potential to significantly alter the disease process.
Publisher: Elsevier BV
Date: 06-2023
Publisher: Wiley
Date: 07-2001
DOI: 10.1007/S11745-001-0776-7
Abstract: Animal and human studies designed to examine the effects of alpha-linolenic acid (ALA) and linoleic acid (LA) supplementation on the fatty acid composition of plasma and tissues have demonstrated a marked difference in incorporation into phospholipids of these 18-carbon precursors of the long-chain polyunsaturates. Whereas tissue phospholipid levels are linearly related to dietary ALA and LA, the levels of tissue LA can be 10-fold higher than tissue ALA even when dietary levels are equivalent. There is some dispute whether this disparity is due to ALA being more rapidly metabolized to its products or substantially oxidized by the liver, or whether LA but not ALA is readily incorporated into cellular phospholipids. We examined the level of incorporation of polyunsaturated fatty acids into human respiratory epithelial cell lines (A549, 16HBE) by determining the dose-dependent incorporation of ALA and LA as free fatty acid (5-150 microg FFA/mL). Cell membrane phospholipid ALA and LA were both increased up to approximately 20-30% total fatty acids, with a concomitant decrease predominantly in monounsaturated membrane fatty acids, before significant toxicity was observed (50 microg/mL). Our data support the concept that rather than any inherent inability by human cells to incorporate ALA into membrane phospholipids, the lack of ALA content in human and animal tissues in vivo is due to the rapid metabolism or oxidation of this fatty acid in the liver.
Publisher: Elsevier BV
Date: 2020
No related grants have been discovered for Min Xiao.