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1.
Eur Eat Disord Rev ; 31(6): 802-812, 2023 11.
Article in English | MEDLINE | ID: mdl-37406031

ABSTRACT

OBJECTIVE: In April 2022 the Calorie Labelling (Out of Home) Regulations came into effect in England where cafés, restaurants, and takeaways with over 250 employees were required to provide calorie labelling on menus. Concerns have been raised regarding the potential negative impact this could have on individuals with eating disorders (EDs), yet this has not been explored using qualitative methodology. METHOD: Eleven participants with a current or previously diagnosed restrictive ED were interviewed in September 2022. Interpretative Phenomenological Analysis (IPA) was used to explore their experience of the introduction of calories on menus. RESULTS: Using IPA we established six themes and seven subordinate themes. These included the introduction of calories on menus as an 'attack' on individuals with EDs; the prominent visual display of calories as an attentional pull; normalising of calories counting; the impact on behaviour; and associated strategies for managing. CONCLUSION: This contributes to research surrounding the implications for public health policies on individuals with EDs, especially their ability to reinforce and amplify disordered thoughts and behaviours, and the need for greater consideration of how to minimise impact and potential harm of large public health campaigns.


Subject(s)
Feeding and Eating Disorders , Food Labeling , Humans , Food Labeling/methods , Energy Intake , Feeding Behavior , Restaurants
2.
Eat Behav ; 46: 101660, 2022 08.
Article in English | MEDLINE | ID: mdl-35933925

ABSTRACT

Research suggests that the COVID-19 pandemic is negatively impacting mental health, with rates of eating disorder referrals in particular rising steeply during the pandemic. This study aimed to examine 8-month changes in body image and disordered eating during the COVID-19 pandemic, and explore whether any changes were moderated by gender, age, or eating disorder history. This study used a longitudinal survey design in which 587 adults living in the UK (85 % women; mean age = 32.87 years) completed assessments every two months over five timepoints from May/June 2020 to January/February 2021. Measures included body esteem, disordered eating, and psychological distress. Mixed effect models showed small but significant improvements in body esteem and disordered eating symptoms from May/June 2020 to January/February 2021. These improvements were independent of changes in psychological distress, and did not vary by gender, age or eating disorder history. Whilst poor body image and disordered eating may have been elevated in the early period of the pandemic, this study suggests improvements, rather than worsening, of these outcomes over time. This may reflect adaptation to this changing context.


Subject(s)
COVID-19 , Feeding and Eating Disorders , Adult , Body Image/psychology , COVID-19/epidemiology , Feeding and Eating Disorders/epidemiology , Female , Humans , Male , Pandemics , United Kingdom/epidemiology
3.
Appetite ; 168: 105755, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34648909

ABSTRACT

Parental restriction of food intake has been associated with heightened eating disorder psychopathology in some longitudinal research. Yet, relatively little is known about the determinants of restrictive feeding practices. This cross-sectional study explored the association between parents' anti-fat attitudes and their use of restrictive feeding practices in a mixed British (41.10% England, 39.90% Scotland, 4.20% Other) and Irish (14.80%) sample. Parents and caregivers (N = 472; 94.10% female; 70.90% university level education) of children between the ages of 4-8 (48.20% female; 91.10% rated as "normal weight" by their parents) completed self-report questionnaires assessing their anti-fat attitudes (dislike, fear, and blame subscales), use of restrictive feeding practices (for weight control, health purposes, and covert restriction), and how influential their child's body-weight and -shape is for their perception of themselves as parents. Overall, our hypothesis that parental anti-fat attitudes would be significantly associated with restrictive feeding practices was supported. Anti-fat attitudes related to disliking higher body-weight people and blaming parents for their child's weight were significant predictors of all forms of restrictive feeding (all ps < .05). However, anti-fat attitudes related to fearing being a higher body-weight were not significant predictors of restrictive feeding for the purposes of health nor for covert restriction (ps > .05). Additionally, our hypothesis that the associations between anti-fat attitudes and restrictive feeding practices would be stronger for parents for whom their child's body-weight and -shape more strongly influenced how they judged themselves as parents was not supported (the interaction term was not significant in two out of three analyses). Future research is needed to investigate these associations across time and in samples of higher body-weight children.


Subject(s)
Feeding Behavior , Parents , Attitude , Body Mass Index , Body Weight , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Male , Overweight , Parenting , Surveys and Questionnaires
4.
Appetite ; 155: 104797, 2020 12 01.
Article in English | MEDLINE | ID: mdl-32652100

ABSTRACT

The main objective of this systematic review was to provide a comprehensive overview of the psychometric properties of all available Orthorexia Nervosa (ON) assessment tools, in order to evaluate their scope of application for research and practice. Ten databases were searched for studies quantitatively assessing ON. The psychometric properties were evaluated according to specified quality criteria, focusing on the reliability, structural validity and construct validity of the scales. A meta-analytic approach was used to summarize eligible Cronbach's alpha coefficients between studies. Sixty-eight unique studies fulfilled the inclusion criteria for this systematic review. Ten discrete ON scales were identified. Half of the included studies exclusively utilized a version of the ORTO-15. The evaluation of all available ON measures raise issues regarding ON's dimensionality and conceptualization. Most of the identified scales require further validation. Based on the reported psychometric properties it is advised to re-evaluate existing tools and to focus on establishing consensus regarding the conceptualization of ON to establish a measure with sound psychometric properties.


Subject(s)
Feeding and Eating Disorders , Concept Formation , Feeding and Eating Disorders/diagnosis , Generalization, Psychological , Humans , Psychometrics , Reproducibility of Results
5.
Arch Microbiol ; 188(4): 299-305, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17492269

ABSTRACT

Mortierella alpina is an oleaginous filamentous fungus whose vegetative mycelium is known to accumulate triglyceride oil containing large amounts of arachidonic acid (ARA 20:4, n - 6). We report that the spores of Mortierella alpina also contain a large proportion of ARA, comprising 50% of total fatty acid. Fatty acid desaturase genes were not expressed in dormant spores but were induced during germination, following a significant drop in the level of ARA (down from 50% of total fatty acid to 12%) prior to germ-tube emergence. We propose that ARA serves as a reserve supply of carbon and energy that is utilised during the early stages of spore germination in Mortierella alpina.


Subject(s)
Arachidonic Acid/metabolism , Fatty Acid Desaturases/biosynthesis , Gene Expression Regulation, Fungal , Mortierella/growth & development , Mortierella/metabolism , Spores, Fungal/chemistry , Base Sequence , DNA, Fungal/chemistry , DNA, Fungal/genetics , Fatty Acid Desaturases/genetics , Molecular Sequence Data , RNA, Fungal/biosynthesis , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Spores, Fungal/genetics
6.
J Chromatogr A ; 1120(1-2): 291-8, 2006 Jul 07.
Article in English | MEDLINE | ID: mdl-16364334

ABSTRACT

This study describes the chemometric treatment of vanillin fingerprint chromatograms to distinguish vanillin from different sources. Prior to principal component analysis, which is used to discriminate vanillin from different origins, the fingerprints are aligned. Three alignment algorithms are tested, correlation optimized warping (COW), target peak alignment (TPA) and semi-parametric time warping (STW). The performance of the three algorithms is evaluated and the effect of the different alignments on the PCA score plots is investigated. The alignment obtained with STW differs somewhat from that with COW and TPA. However, equivalent score plots were obtained regarding the different vanillin groups.


Subject(s)
Algorithms , Benzaldehydes/analysis , Chromatography/methods , Principal Component Analysis/methods , Benzaldehydes/chemistry , Benzaldehydes/isolation & purification , Reproducibility of Results
7.
Mol Genet Genomics ; 274(4): 410-8, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16160852

ABSTRACT

A subtraction library was prepared from cultures of Aspergillus niger that had or had not been exposed to dithiothreitol (DTT), in order to identify genes involved in the unfolded protein response (UPR) or in the response to reductive stress. A large fraction of the clones in the library (40%) encoded two putative methyltransferases (MTs) whose function has yet to be determined. Other stress-responsive genes included a homologue of the Mn2+-containing superoxide dismutase gene (sodB) and a number of genes predicted to code for products that function in protein turnover and in intra- and extracellular transport of molecules. Transcriptional microarray analysis was carried out with a group of 15 genes, comprising 11 from the cDNA library, two genes linked to the putative MT genes but not represented in the library, and two UPR control genes (bipA and pdiA). Eleven of the 15 genes were inducible with DTT. This was either reflected by the presence of transcripts in cells subjected to DTT stress compared to absence under control conditions, or by an induction ratio of between 1.4 and 8.0 in cases where transcripts were already detectable under control conditions. The MT genes were among the four most highly induced. None of the genes, apart from bipA and pdiA, showed significant induction in response to other stresses that are known to induce the UPR in fungi. We conclude that DTT alone does not provide for specific induction of UPR genes and that other stress conditions must also be examined.


Subject(s)
Aspergillus niger/genetics , Aspergillus niger/metabolism , Dithiothreitol/chemistry , Gene Expression Regulation, Fungal , Amino Acid Sequence , DNA, Complementary/metabolism , Fungal Proteins/chemistry , Gene Library , Molecular Sequence Data , Oligonucleotide Array Sequence Analysis , Oxidative Stress , Plasmids/metabolism , Protein Folding , Saccharomyces cerevisiae/metabolism , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Transcription, Genetic
8.
Transplant Proc ; 35(4): 1499-502, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12826204

ABSTRACT

Human fetal pancreas (HFP) is a potential source of transplantable islets for the treatment of type 1 insulin-dependent diabetes mellitus (IDDM). Pretransplant culture techniques such as long-term culture, high-oxygen culture, UVB irradiation, and low-temperature culture have previously been used to reduce the immunogenicity of tissue for transplantation. In this study, we use hyperbaric oxygen culture (HOC) to modify MHC Class I expression on HFP and to reduce the immunological response of human peripheral blood mononuclear cells (PBMC) to HFP using a sponge matrix allograft model. To study the interaction of naïve PBMC with HOC-treated or untreated HFP allografts, sponges embedded with HFP tissue were implanted into the peritoneal cavity of NOD-SCID mice and injected with 1 x 10(7) freshly isolated human PBMC at the time of transplant. By day 14, human CD45 cells represented less than 2% of the cells recovered from the sponges implanted with HOC-treated HFP. In contrast, human CD45(+) cells represented nearly 15% (P =.0018) of the cells isolated from sponges implanted with conventionally cultured HFP grafts. Approximately 75% of the human CD45(+) cells from conventionally cultured HFP allografts were producing IFNgamma as determined by intracellular cytokine analysis. These data suggest that HOC treatment of HFP abrogates the activation and proliferation of PBMC. Pretransplant HOC treatment of islets is a simple technique that could be used to reduce immunogenicity and increase allograft survival while decreasing the requirement for immunosuppressive drugs.


Subject(s)
Fetal Tissue Transplantation/immunology , Pancreas Transplantation/immunology , Pancreas , Animals , Antigens, CD/analysis , Diabetes Mellitus, Type 1/surgery , Disease Models, Animal , Histocompatibility Testing , Humans , Hyperbaric Oxygenation , Leukocyte Common Antigens/analysis , Major Histocompatibility Complex , Mice , Mice, Inbred NOD , Organ Culture Techniques , Pancreas/embryology , Protein Tyrosine Phosphatase, Non-Receptor Type 1 , Transplantation, Homologous
9.
Transplant Proc ; 35(4): 1506-7, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12826206

ABSTRACT

Human fetal pancreas (HFP) is a potential source of islets for the treatment of diabetes mellitus with the potential for growth and differentiation after transplantation. However, because of the small mass of a given HFP, multiple donors would be required for transplantation, thereby increasing the immunological challenge to the recipient. In this study, we investigate the contribution of hematopoietic cells to the immunogenicity of HFP. Single cell suspensions of HFP were depleted of CD45(+) cells using antibody-conjugated magnetic beads. In vitro mixed lymphocyte islet cultures were established using with CD45-depleted or nondepleted HFP. Depletion of CD45(+) cells resulted in the low levels of IFNgamma production at early time points (day 4), which increased to near normal levels by day 7. The development of donor-specific CTL was not consistently inhibited by CD45 cell depletion. The data suggests that CD45(+) cells within HFP are capable of stimulating immune responses by the direct pathway of antigen presentation, but that the indirect pathway is also involved in the development of CTL. The inhibition of early IFNgamma release, however, may be beneficial for the survival of transplanted islets. Therefore, the combination of CD45 depletion strategies with standard immunosuppressive drug therapies could result in better long-term survival of transplanted islets.


Subject(s)
Leukocyte Common Antigens/analysis , Pancreas/embryology , T-Lymphocytes, Cytotoxic/cytology , Abortion, Induced , Antigens, CD/analysis , Female , Fetal Tissue Transplantation , Humans , Islets of Langerhans/embryology , Islets of Langerhans/immunology , Islets of Langerhans Transplantation , Lymphocyte Depletion/methods , Organ Culture Techniques , Pancreas/immunology , Pregnancy , T-Lymphocytes, Cytotoxic/immunology , Vacuum Curettage/methods
10.
Int J Med Microbiol ; 291(6-7): 561-70, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11892683

ABSTRACT

There is increasing evidence for the involvement of bacterial toxins in some cases of sudden infant death syndrome (SIDS), particularly the pyrogenic toxins of Staphylococcus aureus. This had led to the hypothesis that some SIDS deaths are due to induction of inflammatory mediators by infectious agents or their products during a period in which the infant is unable to control these normally protective responses. The genetic, developmental and environmental risk factors identified for SIDS are assessed in relation to frequency or density of mucosal colonisation by toxigenic bacteria and their effects on induction and control of inflammatory responses to the toxins.


Subject(s)
Bacterial Infections/complications , Bacterial Toxins , Sudden Infant Death/etiology , Humans , Infant , Infant, Newborn , Risk Factors , Smoking , Staphylococcal Infections/complications
11.
Child Care Health Dev ; 28 Suppl 1: 27-9, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12515435

ABSTRACT

There is increasing evidence that inflammatory responses have been elicited in some Sudden Infant Death Syndrome (SIDS) infants and that these responses are under genetic control. The objective of this study was to investigate the hypothesis that the cytokine responses of SIDS parents (n = 41) differed significantly from control donors (n = 61). Blood samples were stimulated with the staphylococcal toxin TSST-1 and LPS from Eschericia coli and assessed for production of TNF, IL-1, IL-6, IFN and IL-10. In response toTSST-1 (P < 0.02) and LPS (P < 0.002), SIDS parents produced higher levels of IL-1 than the controls. SIDS parents produced higher levels of IFN in response to TSST-1 compared to LPS (P < 0.001) although in response to LPS, the IFN (P = 0.0008) and IL-6 (P < 0.0002) responses of the SIDS parents were lower than those of the controls. For TNF and IL-10, there was little difference between the two groups unless the effect of smoking was considered. As part of this work, a small pilot genotyping study was carried out using DNA from SIDS parents (n = 10), control donors (n = 10) and Bangladeshi subjects (n = 10). An IFN polymorphism (3/3) was found in 40%,15.4% and 0% of donors respectively. Staphylococcal toxins have been identified in SIDS infants therefore this study highlights the importance of assessing IL-1 levels. Determination of cytokine polymorphisms and consideration of interactions between these and environmental factors such as smoking in high, average and low risk ethnic groups will assist in establishing the contribution of these factors to an infant's susceptibility to SIDS.


Subject(s)
Sudden Infant Death/genetics , Bangladesh , Case-Control Studies , Cytokines/biosynthesis , Female , Genetic Predisposition to Disease , Genotype , Humans , Infant , Inflammation/blood , Inflammation/complications , Interferons/blood , Interferons/genetics , Interleukin-1/blood , Interleukin-1/genetics , Interleukin-6/blood , Interleukin-6/genetics , Male , Polymorphism, Genetic
12.
FEMS Immunol Med Microbiol ; 29(4): 271-4, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11118907

ABSTRACT

Criticisms of serological studies on Helicobacter pylori and ischaemic heart disease (IHD) include: undiagnosed heart disease in live controls; no assessment of severity or outcome of IHD; and qualitative not quantitative measurements of IgG to the bacteria. The aim was to assess quantitatively IgG levels specific for H. pylori (ng ml(-1)) among patients who survived a myocardial infarction (MI) with those who died of IHD. Sera were from four groups: (1) men who survived one MI; (2) men matched for age and socioeconomic background to group 1; (3) individuals who died suddenly of IHD; (4) accidental deaths matched for age and sex to group 3. Levels of IgG to H. pylori increased with age (P<0.005) but were not associated with smoking or socioeconomic groups. There was a correlation between IgG to the bacteria and decreasing socioeconomic levels only among group 1 (P<0.01). IgG levels were higher for subjects who died of heart disease (median=151 ng ml(-1)) compared with survivors (median=88 ng ml(-1)) (P=0.034) and higher for survivors compared with their controls (median=58 ng ml(-1)) (P=0.039). Future serological studies of H. pylori in relation to IHD should be quantitative and severity of disease considered in analyses.


Subject(s)
Antibodies, Bacterial/blood , Helicobacter Infections/complications , Helicobacter pylori/immunology , Myocardial Ischemia/microbiology , Female , Humans , Immunoglobulin G/blood , Male , Matched-Pair Analysis , Middle Aged , Myocardial Infarction/microbiology , Myocardial Ischemia/mortality , Pilot Projects , Severity of Illness Index
13.
Appl Environ Microbiol ; 66(11): 4655-61, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11055907

ABSTRACT

Mortierella alpina was transformed successfully to hygromycin B resistance by using a homologous histone H4 promoter to drive gene expression and a homologous ribosomal DNA region to promote chromosomal integration. This is the first description of transformation in this commercially important oleaginous organism. Two pairs of histone H3 and H4 genes were isolated from this fungus. Each pair consisted of one histone H3 gene and one histone H4 gene, transcribed divergently from an intergenic promoter region. The pairs of encoded histone H3 or H4 proteins were identical in amino acid sequence. At the DNA level, each histone H3 or H4 open reading frame showed 97 to 99% identity to its counterpart but the noncoding regions had little sequence identity. Unlike the histone genes from other filamentous fungi, all four M. alpina genes lacked introns. During normal vegetative growth, transcripts from the two histone H4 genes were produced at approximately the same level, indicating that either histone H4 promoter could be used in transformation vectors. The generation of stable, hygromycin B-resistant transformants required the incorporation of a homologous ribosomal DNA region into the transformation vector to promote chromosomal integration.


Subject(s)
DNA, Ribosomal/genetics , Genetic Vectors/genetics , Histones/genetics , Mortierella/genetics , Promoter Regions, Genetic/genetics , Transformation, Genetic , DNA, Fungal/genetics , Fatty Acids, Unsaturated/metabolism , Molecular Sequence Data , Mortierella/metabolism , Oils/chemistry , Oils/metabolism
14.
Hum Immunol ; 61(12): 1320-31, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11163089

ABSTRACT

We have previously shown that hyperbaric oxygen culture (HOC [95% O(2), 5% CO(2), 25 psi]) is an effective pretransplant tissue-modification technique that results in long-term allograft survival and the induction of systemic immune tolerance in a murine model. Here we address the immune modulatory effects of HOC-treatment of human immune responses using the in vitro mixed lymphocyte reaction (MLR). Pretreatment of allogeneic stimulator cells with HOC results in abrogation of cytotoxic T lymphocyte (CTL) activity, proliferative responses, and IFN gamma production in a 7-day MLR. These responses can be restored either by the addition of IFN gamma or IL-2 on day 0, or by blocking the activity of IL-4 and IL-10. The addition of IL-2 on day 4 does not restore allospecific CTL activity. The failure of HOC-treated cells to induce allospecific CTL is not due to the induction of anergy, demonstrated by the failure to restore responses after restimulation with allogeneic cells in the presence of IL-2. Removal of CD4(+) cells prior to restimulation, results in restoration of CTL activity in MLR cultures restimulated with HOC-treated allogeneic cells. These results suggest that HOC-induced immune nonresponsiveness is mediated by the development of CD4(+) regulatory cells in a Th2-type environment.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Hyperbaric Oxygenation , Immune Tolerance/immunology , Antibodies, Blocking/pharmacology , CD4-Positive T-Lymphocytes/metabolism , Cells, Cultured , Clonal Anergy/immunology , Cytokines/biosynthesis , Cytotoxicity Tests, Immunologic/methods , Humans , Immune Sera/pharmacology , Interferon-gamma/pharmacology , Interleukin-10/antagonists & inhibitors , Interleukin-10/immunology , Interleukin-4/antagonists & inhibitors , Interleukin-4/immunology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lymphocyte Activation/immunology , Lymphocyte Culture Test, Mixed/methods , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/metabolism , Th2 Cells/immunology , Th2 Cells/metabolism
15.
Microbiology (Reading) ; 145 ( Pt 10): 2939-46, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10537216

ABSTRACT

Genes encoding two distinct fatty acid delta9-desaturases were isolated from strains of the oleaginous fungus Mortierella alpina. Two genomic sequences, delta9-1 and delta9-2, each containing a single intron, were cloned from strain CBS 528.72 while one cDNA clone, LM9, was isolated from strain CBS 210.32. The delta9-1 gene encoded a protein of 445 aa which shared 99% identity with the LM9 gene product. These proteins also showed 40-60% identity to the delta9-desaturases (Ole1p) of other fungi and contained the three conserved histidine boxes, C-terminal cytochrome b5 fusion and transmembrane domains characteristic of endoplasmic reticulum membrane-bound delta9-desaturases. LM9 and delta9-1 are therefore considered to represent the same gene (ole1). The ole1 gene was transcriptionally active in all M. alpina strains tested and its function was confirmed by complementation of the Saccharomyces cerevisiae ole1 mutation. Fatty acid analysis of yeast transformants expressing the CBS 210.32 ole1 gene showed an elevated level of oleic acid (18:1) compared to palmitoleic acid (16:1), the major fatty acid component of wild-type S. cerevisiae. This indicated that the M. alpina delta9-desaturase had a substrate preference for stearic acid (18:0) rather than palmitic acid (16:0). Genomic clone delta9-2 (ole2) also encoded a protein of 445 aa which had 86% identity to the delta9-1 and LM9 proteins and whose ORF also complemented the yeast ole1 mutation. The transcript from this gene could only be detected in one of the six M. alpina strains tested, suggesting that its expression may be strain-specific or induced under certain physiological conditions.


Subject(s)
Fatty Acid Desaturases/genetics , Genetic Complementation Test/methods , Mortierella/genetics , Mutation/genetics , Saccharomyces cerevisiae/genetics , Fatty Acid Desaturases/biosynthesis , Fatty Acid Desaturases/isolation & purification , Fatty Acid Desaturases/metabolism , Genes, Fungal , Molecular Sequence Data , Mortierella/enzymology , Saccharomyces cerevisiae/enzymology , Stearoyl-CoA Desaturase
16.
FEMS Immunol Med Microbiol ; 25(1-2): 51-8, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10443491

ABSTRACT

Many developmental and environmental risk factors for sudden infant death syndrome (SIDS) are similar to those for susceptibility to respiratory tract infection, and toxigenic bacteria have been implicated in some SIDS cases. We assessed nasopharyngeal flora of healthy infants in relation to risk factors to determine which species best lit the mathematical model proposed for the common bacterial toxin hypothesis and if these findings complemented results obtained from SIDS cases which occurred during the period of the survey. Longitudinal studies were carried out between April 1993 and March 1996 on 253 healthy infants and their mothers. 150 from a multiply deprived area, 103 from an affluent area. Concurrent SIDS infants (37) were screened for nasopharyngeal flora. Among healthy infants < or = 3 months of age, the predominant isolate was Staphylococcus aureus 57% compared with 86% for SIDS infants in that age range (P< 0.02). There were significant associations between isolation of different species from both mother and baby but no association between isolation of any species with: area of residence: parental smoking habits; breast or bottle feeding; symptoms of viral infection: seasonality. We conclude that S. aureus fits the mathematical model for SIDS. Both staphylococci and/or their toxins were identified in a significant proportion of SIDS cases. Isolation of staphylococci from healthy infants was associated with the 2-4-month age range, a risk factor consistently found in all epidemiological studies of SIDS. This might reflect the developmental stage in which 80-90% of infants express the Lewis(a) antigen which we have shown to be one of the receptors for S. aureus.


Subject(s)
Bacteria/isolation & purification , Nasopharynx/microbiology , Sudden Infant Death/etiology , Bacteria/classification , Fathers , Female , Humans , Infant , Infant, Newborn , Longitudinal Studies , Male , Mothers , Risk Factors , Smoking , Social Class , Staphylococcus aureus/isolation & purification , Sudden Infant Death/epidemiology
17.
FEMS Immunol Med Microbiol ; 25(1-2): 103-8, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10443497

ABSTRACT

It has been suggested that pyrogenic toxins of Staphylococcus aureus are involved in the series of events leading to some cases of sudden infant death syndrome (SIDS). The objectives of the study were to screen tissues from SIDS infants for pyrogenic toxins and to compare incidence of identification of these toxins among these infants from different countries. An enzyme-linked immunosorbent assay (ELISA) and a flow cytometry method were used to screen body fluids and frozen or formalin-fixed tissues for pyrogenic toxins of S. aureus, toxic shock syndrome toxin 1 (TSST), staphylococcal enterotoxins A (SEA), B (SEB), and C1 (SEC). Toxins were identified in tissues of 33/62 (53%) SIDS infants from three different countries: Scotland (10/ 19, 56%); France (7/13, 55%); Australia (16/30, 53%). In the Australian series, toxins were identified in only 3/19 (16%) non-SIDS deaths (chi2 = 5.42, P < 0.02). The flow cytometry method was useful for toxin detection in both frozen and fixed tissues, but ELISA was suitable only for frozen tissues or those fixed for less than 12 months. Identification of pyrogenic toxins in > 50% of SIDS infants from three different countries indicated further investigation into the role the toxins play in cot deaths might result in development of additional measures to reduce further the incidence of these infant deaths.


Subject(s)
Bacterial Toxins , Enterotoxins/analysis , Staphylococcus aureus , Sudden Infant Death/etiology , Superantigens , Brain/microbiology , Child , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Formaldehyde , Freezing , Humans , Infant , Infant, Newborn , Kidney/microbiology , Spleen/microbiology , Staphylococcus aureus/isolation & purification , Tissue Fixation
18.
FEMS Immunol Med Microbiol ; 25(1-2): 155-65, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10443504

ABSTRACT

Epidemiological studies indicate that breast-fed infants are at a decreased risk of sudden infant death syndrome (SIDS) compared to formula-fed infants. Increasing evidence suggests that infectious agents might be involved in some of these deaths, in particular bacteria which colonise mucosal surfaces and produce superantigenic toxins. One species implicated in recent studies of SIDS infants is Staphylococcus aureus. We tested the hypothesis that in comparison to infant formula, human milk might be a better inhibitor of binding of S. aureus to epithelial cells. In this study, two protocols were used for the binding assays which were assessed by flow cytometry: the in vitro method in which bacteria were treated with milk or formula, washed and added to epithelial cells; and a method more closely reflecting the competitive interactions in vivo in which cells, bacteria, and milk or infant formula were added at the same time. With the in vivo method, breast milk caused enhancement of bacterial binding to cells whilst infant formula caused inhibition; however, for the in vitro method, both human milk and infant formula caused consistent enhancement of binding. Flow cytometry and light microscopy studies indicated that the enhancement was due to the formation of bacterial aggregates. Human milk and infant formula preparations were also compared for components (antibodies or oligosaccharides) that could inhibit binding of S. aureus using the in vitro method. Human milk contained both IgA and IgG. Neither human milk nor infant formula contained oligosaccharides reactive with the Ulex europaeus lectin but both contained components that bound monoclonal antibodies to Lewis(a) and Lewis(b) antigens which can act as receptors for S. aureus. With both methods, synthetic Lewis(a) and Lewis(b) inhibited S. aureus binding in a dose-dependent manner. With human milk, however, the only component which showed a significant correlation with inhibition of binding was the IgA specific for the staphylococcal surface component that binds Lewis(a). Both human milk and infant formula contain components which could potentially inhibit bacterial binding but only breast milk contains the IgA specific for the bacterial adhesin that binds Lewis(a). Studies using the in vivo method suggest that protection associated with breast feeding in relation to SIDS could be due mainly to the formation of bacterial aggregates. The studies have implications for further research into constituents of infant formula.


Subject(s)
Breast Feeding , Epithelial Cells/microbiology , Infant Food , Milk, Human , Staphylococcus aureus/metabolism , Sudden Infant Death/prevention & control , Adult , Animals , Bacterial Adhesion , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant , Infant, Newborn , Lewis Blood Group Antigens/metabolism , Milk, Human/chemistry , Staphylococcus aureus/drug effects , Tumor Cells, Cultured
19.
FEMS Immunol Med Microbiol ; 25(1-2): 167-73, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10443505

ABSTRACT

Breast feeding is known to protect an infant against gastrointestinal pathogens and epidemiological studies indicate that compared to breast fed infants, formula fed infants are at a greater risk of dying from sudden infant death syndrome (SIDS). Many SIDS infants have symptoms of gastrointestinal infections prior to death and one gastrointestinal pathogen associated with SIDS is Clostridium perfringens. Studies have found that a significantly higher number of formula fed SIDS infants have C perfringens and its enterotoxin in their faeces compared to breast fed infants. The aim of the study was to compare the effects of human milk and infant formula on binding of C perfringens to epithelial cells. Two protocols were used to assess the effect of human milk and infant formula to inhibit binding of C perfringens to epithelial cells. Binding was assessed by flow cytometry. For the in vivo protocol which more closely represents interactions on the mucosal surface, breast milk enhanced bacterial binding but infant formula caused inhibition of binding; however for the in vitro method, both human milk and infant formula resulted in consistent enhancement of binding. Flow cytometry studies indicated that enhancement of binding was due to the formation of bacterial aggregates. Lewis(a) and Lewis(b) antigens, found in both breast milk and infant formula, inhibited C. perfringens binding in a dose dependent manner. The Lewis(a) and Lewis(b) antigens in human milk and infant formula can inhibit C. perfringens binding to epithelial cells. While infant formula reduced binding of C. perfringens to epithelial cells in the experiments carried out with the in vivo protocol, the protective effects of breast feeding in relation to colonisation with C. perfringens are more likely to be due to formation of bacterial aggregates. These findings have implications for improving infant formula preparations.


Subject(s)
Breast Feeding , Clostridium perfringens/metabolism , Epithelial Cells/microbiology , Infant Food , Milk, Human , Sudden Infant Death/prevention & control , Animals , Bacterial Adhesion , Humans , Infant , Infant, Newborn , Lewis Blood Group Antigens/metabolism , Milk, Human/chemistry , Tumor Cells, Cultured
20.
FEMS Immunol Med Microbiol ; 25(1-2): 175-82, 1999 Aug 01.
Article in English | MEDLINE | ID: mdl-10443506

ABSTRACT

Two toxin-producing bacteria implicated in sudden infant death syndrome (SIDS) are Staphylococcus aureus and Clostridium perfringens. Epidemiological studies have shown that breast feeding reduces an infant's risk of SIDS. This protective effect could be due partly to IgA antibodies to these toxins in human milk. The aim of this work was to use a quantitative ELISA to determine levels of IgA antibodies that bound to toxic shock syndrome toxin (TSST-1), staphylococcal enterotoxin C (SEC) and C. perfringens enterotoxin A (CEA) in individual samples of human milk. All samples of milk tested contained IgA antibodies that bound to the bacterial toxins. For individual samples, IgA bound to TSST-1, SEC and CEA were in the range of 900-3100 ng ml(-1), 1000-3600 ng ml(-1) and 1000-4300 ng ml(-1) respectively. Isolation of S. aureus from mothers donating breast milk samples was used to determine if the presence of bacteria affected IgA levels which bound TSST-1 and SEC. For 3/5 samples with levels above the upper limit of the standard deviation (2375 ng ml(-1)) for IgA bound to TSST-1, S. aureus was isolated from the mother whilst 4/5 samples found to contain levels above the upper limit of the standard deviation (2627 ng ml(-1)) for IgA bound to SEC, had S. aureus isolated from the mother. In conclusion, if bacterial toxins do play a role in precipitating a SIDS death, the presence of IgA antibodies to toxins in breast milk, but not in infant formula, might contribute to the protective effect of breast feeding in relation to SIDS.


Subject(s)
Bacterial Toxins , Breast Feeding , Enterotoxins/immunology , Immunoglobulin A/analysis , Milk, Human/immunology , Sudden Infant Death/prevention & control , Superantigens , Adult , Animals , Antibodies, Bacterial/analysis , Antibodies, Bacterial/immunology , Clostridium perfringens/immunology , Clostridium perfringens/metabolism , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin A/immunology , Infant , Infant Food , Infant, Newborn , Nose/microbiology , Pharynx/microbiology , Staphylococcus aureus/immunology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/metabolism
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