Association among EPHB2, TrkA, and MYCN expression in low-stage neuroblastomas

BACKGROUND

The EPH family is the largest subfamily of receptor protein-tyrosine kinases, consisting of EPHA and EPHB subgroups. Ligands of EPH family receptors are called ephrins, which include ephrin-A and ephrin-B subgroups. We recently found that transcripts encoding the EPHB subgroup (EPHB) and the ephrin-B subgroup (EFNB) were expressed together in neuroblastoma (NB) cell lines.

PROCEDURE

In this study, we examined the expression of EPHB and EFNB transcripts in 24 NB specimens representing all clinical stages. We found that several EPHB and EFNB transcripts were expressed together in all NBs examined.

RESULTS

Among the transcripts examined, EPHB6 expression was most significantly associated with low stage tumors (stages 1, 2, and 4S; P = 0.0048). TrkA expression was significantly correlated with EPHB6, EFNB2, and EFNB3 expression (P < 0.01 in each case). Taken together, these data indicate that the expression of EPHB6, EFNB2, and EFNB3 may serve as prognostic indicators of favorable NBs. In the low-stage NBs without MYCN amplification, EPHB2 expression was correlated both with MYCN expression and with TrkA expression (P < 0.01 in each case). Moreover, MYCN expression was correlated with TrkA expression (P < 0.01) in the low-stage NBs.

CONCLUSIONS

This observation points to the possibility that MYCN expression might contribute to favorable outcome of low-stage NBs.

Effect of CEP-751 (KT-6587) on neuroblastoma xenografts expressing TrkB

BACKGROUND

The compound CEP-751 (KT-6587), a potent and selective inhibitor of the Trk family of tyrosine kinases, has been shown to inhibit the growth of human neuroblastoma (NB) xenografts in nude mice [1].

PROCEDURE

To address its mechanism of action, we studied SY5Y, a human NB cell line with no detectable Trk expression, and two subclones transfected with TrkB. The transfected clones, SY5Y (G8) and SY5Y (G12), expressed moderate and high levels, respectively, of TrkB mRNA and protein. These TrkB-expressing subclones and the parental line were then grown as xenografts in nude mice, and CEP-751 was used to inhibit TrkB tyrosine kinase activity in these xenografts. Animals were treated twice a day with CEP-751 (21 mg/kg), or with the carrier vehicle as a control. TrkB expression in the resultant tumors was examined by quantitative RT-PCR. The effect of CEP-751 on TrkB activation by BDNF was examined in G12 cells in culture by immunoprecipitation with antipan Trk antiserum, followed by Western blot analysis using antiphosphotyrosine antibodies. To determine if CEP-751 was causing apoptosis, the TUNEL assay was used.

RESULTS

CEP-751 had little effect on the growth of SY5Y tumors, but did slow the growth rate of the C8 and G12 tumors. The daily growth rate of the treated tumors was 0.16, 0.13, and 0.10 cm3, respectively, for the SY5Y, G8, and G12 tumors. RT PCR analysis confirmed the expression of TrkB in G8 and G12, but not in SY5Y tumors. Activation of TrkB by BDNF in G12 cells was inhibited by CEP-751 in a dose dependent fashion. The treated tumors showed marked evidence of apoptosis.

CONCLUSIONS

These data suggest that the effect of CEP-751 is due, at least in part, to its inhibition of TrkB kinase, and that CEP-751 may become a useful therapeutic tool for the treatment of aggressive neuroblastomas, which often express TrkB.

Expression of neurotrophin receptor TrkA inhibits angiogenesis in neuroblastoma

BACKGROUND

Mechanisms regulating the expression of angiogenic factors in tumor cells are largely unknown. High expression of the neurotrophin receptor TrkA in neuroblastomas (NB) is associated with favorable prognosis, whereas TrkB is expressed on aggressive, MYCN-amplified NB.

PROCEDURE

To investigate the biological effects of TrkA and TrkB expression on angiogenesis in NB, we examined the expression of angiogenic factors in the human NB cell line SY5Y and its TrkA and TrkB transfectants.

RESULTS

In comparison to parental SY5Y cells, mRNA and protein levels of angiogenic factors were significantly reduced in SY5Y-TrkA cells, whereas SY5Y-TrkB cells did not demonstrate a significant change. Conditioned medium (CM) of parental SY5Y and SY5Y-TrkB cells induced endothelial cell proliferation, but this effect was completely absent in SY5Y-TrkA cells. TrkA expression also resulted in severely impaired tumorigenicity in a mouse xenograft model, and was associated with reduced angiogenic factor expression and less vascularization of tumors, as determined by immunohistochemistry and an in vivo Matrigel assay.

Prognostic significance of EPHB6, EFNB2, and EFNB3 expressions in neuroblastoma

BACKGROUND

EPH family receptor tyrosine kinases and their ligand ephrins play pivotal roles in development. High-level expression of transcripts encoding EPHB6 receptors (EPHB6), its ligands ephrin-B2 and ephrin-B3 (EFNB2, EFNB3) is predictive of favorable disease outcome of neuroblastoma (NB). When combined with TrkA expression, the expression of EPHB6, EFNB2, or EFNB3 predicts more accurately the disease outcome than each of the four variables alone.

PROCEDURE

Cox regression and Kaplan-Meier analyses were used to assess the prognostic significance of EPHB6, EFNB2, EFNB3, and TrkA expressions in NB without MYCN amplification.

RESULTS

High-level expression of EFNB3 or TrkA predicted favorable NB outcome of NB without MYCN amplification (p < 0.03). As found in the general NB population, EPHB6, EFNB2, or EFNB3 expression in combination with TrkA expression was significantly predictive of the disease outcome of normal MYCN NB (p < 0.01).

CONCLUSIONS

EPHB6, EFNB2, and EFNB3 expressions may permit further refinement of the prognostic stratification of NB into favorable and unfavorable groups.

Angiotensin II type-I receptor and ACE polymorphisms and risk of myocardial infarction in men and women

BACKGROUND

Findings relating an association between an insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene and myocardial infarction (MI) have been mixed. While other loci, such as the angiotensin II type-I receptor (AT1R), may modulate risk, few studies have adequately documented the risk in women. We aimed to study whether the findings in respect of ACE and AT1R in UK men were borne out in women.

METHODS

Cases of MI (305 women, 391 men) in Belfast and Glasgow have been compared to controls (291 women, 356 men). These new samples augment the original men (200 cases, 181 controls) included from Belfast in the ECTIM study.

RESULTS

Among men, the odds ratio for MI for ACE (DD vs. ID + II) was 1.03 (0.79, 1.34) and among women, 0.69 (0.47, 1.01). This heterogeneity between the risks in men and women was significant in Glasgow (P = 0.02). Among men and women the odds ratio for MI for AT1R (CC vs. AC + AA) was 1.02 (0.71, 1.47). There was a small gradient in risk, such that the odds ratio for DD genotype was 0.86 (0.63, 1.17) among subjects homozygous for the common AT1R allele (AA): 0.94 (0.67, 1.30) among heterozygotes and 1.21 (0.53, 2.77) among CC subjects; but this interaction was not statistically significant.

CONCLUSIONS

Some of the contradictory findings concerning the ACE polymorphism and the risk of MI may be due to heterogeneity in the risk between men and women. The AT1R1196 polymorphism is not an independent risk factor for MI in either sex.

Season and outdoor ambient temperature: effects on birth weight

OBJECTIVE

To determine the extent to which meteorologic factors explain seasonality in birth weight in a developed country.

METHODS

Recorded birth weights were collected for all singleton live births after 36 weeks of pregnancy in Northern Ireland between 1971 and 1986. Data on daily maximum and minimum temperatures, rainfall, and hours of bright sunshine were obtained from a local climatologic station for the same period. For each birth, mean daily maximum and minimum temperatures, rainfall, and hours of bright sunshine were calculated for the trimesters of the pregnancy. Linear regression models were constructed with birth weight as the dependent variable and month of birth as a predictor variable. Months of birth were entered in the models as dummy variables. Adjustment was made for year of birth, duration of gestation, maternal age, number of previous pregnancies, sex, and social class of infants at birth and for meteorologic variables relating to each trimester.

RESULTS

A clear seasonal pattern in birth weight was observed, with lowest mean birth weight in late spring and summer. Adjusted mean birth weights were 25.5 g, 29.6 g, and 31.6 g lower in May, June, and July, respectively, than in January. This seasonal variation occurred in both sexes, and in female births, it disappeared almost entirely after adjustment for mean daily maximum temperature during the second trimester of pregnancy.

CONCLUSION

Infants born during late spring and summer are lighter than those born in winter, which might be the result of exposure to low winter temperatures during midgestation. Pregnant women should keep themselves warm during midpregnancy.

Polymorphisms of the P-selectin gene and risk of myocardial infarction in men and women in the ECTIM extension study. Etude cas-temoin de l'infarctus myocarde

BACKGROUND AND OBJECTIVE

Studies in animal models and humans implicate cell adhesion molecules in atherogenesis but their role in mediating the risk of myocardial infarction is unclear. The ECTIM (étude cas-temoin de l'infarctus myocarde) extension study was established to determine whether a previously implicated polymorphism of the P-selectin gene was associated with myocardial infarction risk in men and women in Belfast and Glasgow. PATIENTS AND STUDY SETTING: 696 cases with a recent myocardial infarction and 561 age matched controls (both male and female) were recruited into a case-control study in MONICA project areas of Belfast and Glasgow.

METHODS

Demographic and lifestyle information was collected by interview administered questionnaire, and each subject was examined and provided a blood sample for DNA extraction. The polymerase chain reaction (PCR) was used to amplify regions encompassing the P-selectin Thr-->Pro (A/C) polymorphism at position 715. Genotype odds ratios for myocardial infarction were estimated by logistic regression adjusted for population, age, and sex.

RESULTS

There was no significant association between conventional risk factors (such as hypercholesterolaemia, increased body mass index, or raised blood pressure) and either the rare or the common Pro(715) allele of the P-selectin gene in controls. Overall, comparing Pro(715)/Pro(715) and Pro(715)/Thr(715) with Thr(715)/Thr(715), with adjustment for centre, age, and sex, the odds ratio was 0.78 (95% confidence interval 0.60 to 1.00) (p = 0.054), indicating a "protective" effect of the less common Pro(715) allele. There was no significant heterogeneity in odds ratios between men and women either in this sample or when combined with the original ECTIM subjects.

CONCLUSIONS

In a large population based study in two regions of the UK, we have been able to corroborate the earlier ECTIM findings of a lower frequency of the Thr/Pro(715) polymorphism in subjects with myocardial infarction. An apparently "protective effect" of similar magnitude also seems to apply to women.

Do polymorphisms of apoB, LPL or apoE affect the hypocholesterolemic response to weight loss?

To assess whether there is a differential hypocholesterolemic response to weight loss for subjects carrying polymorphisms of the apolipoprotein B and other genes. A before and after comparison of lipid parameters following a calorie controlled diet for an intervention period of 12 weeks. A lipid clinic based in a large teaching hospital. The difference in slope coefficients relating the percentage change in lipid parameters to the change in body weight (adjusted for age, gender and initial body mass index (BMI)), for genotype subgroups defined by polymorphisms of the 5'VNTR apoB gene, two mutations of the LPL gene and ApoE. One hundred and forty six subjects completed the intervention diet. While, on average, the intervention was successful (mean weight loss 3.9%), there was no statistically significant difference in the slope coefficients relating lipid change to weight loss for most of the genotypes tested. The slope difference for long versus short 5'VNTR alleles of the apoB gene was 0.445 (-1.307, 2.198) for apolipoprotein B and -0. 104 (-1.486, 1.278) for total cholesterol. However, subjects carrying at least one varepsilon4 allele were significantly hypo-responsive to weight loss, difference in slope coefficients -1.087 (-2.09, -0.084) and -1.320 (-2.589, 0.051) for total cholesterol and apoB, respectively. Although, this study is one of the largest of its kind, it has not replicated the findings of other smaller studies. These findings do not provide support for the use of genotype-targeted dietary advice in routine practice.

Implications of EPHB6, EFNB2, and EFNB3 expressions in human neuroblastoma

Neuroblastoma (NB) is a common pediatric tumor that exhibits a wide range of biological and clinical heterogeneity. EPH (erythropoietin-producing hepatoma amplified sequence) family receptor tyrosine kinases and ligand ephrins play pivotal roles in neural and cardiovascular development. High-level expression of transcripts encoding EPHB6 receptors (EPHB6) and its ligands ephrin-B2 and ephrin-B3 (EFNB2, EFNB3) is associated with low-stage NB (stages 1, 2, and 4S) and high TrkA expression. In this study, we showed that EFNB2 and TrkA expressions were associated with both tumor stage and age, whereas EPHB6 and EFNB3 expressions were solely associated with tumor stage, suggesting that these genes were expressed in distinct subsets of NB. Kaplan-Meier and Cox regression analyses revealed that high-level expression of EPHB6, EFNB2, and EFNB3 predicted favorable NB outcome (P<0.005), and their expression combined with TrkA expression predicted the disease outcome more accurately than each variable alone (P<0.00005). Interestingly, if any one of the four genes (EPHB6, EFNB2, EFNB3, or TrkA) was expressed at high levels in NB, the patient survival was excellent (>90%). To address whether a good disease outcome of NB was a consequence of high-level expression of a "favorable NB gene," we examined the effect of EPHB6 on NB cell lines. Transfection of EPHB6 cDNA into IMR5 and SY5Y expressing little endogenous EPHB6 resulted in inhibition of their clonogenicity in culture. Furthermore, transfection of EPHB6 suppressed the tumorigenicity of SY5Y in a mouse xenograft model, demonstrating that high-level expressions of favorable NB genes, such as EPHB6, can in fact suppress malignant phenotype of unfavorable NB.

Computer-assisted instruction: an effective instructional method for HIV prevention education?

PURPOSE

To compare the effectiveness of a computer-assisted instruction (CAI)-based intervention to a more traditional lecture-based intervention for influencing psychosocial correlates of human immunodeficiency virus (HIV) preventive behaviors.

METHODS

Students enrolled in a Human Sexuality course (N = 152) were randomly assigned to one of three groups: CAI, Lecture, or No Intervention group. Participants in the CAI group reviewed a 1-hour long CAI program, participants in the Lecture group were presented with a 1-hour long lecture, and participants in the No Intervention group received no intervention. After completing the respective interventions, all participants completed the HIV questionnaire, which measured selected Social Cognitive Theory constructs associated with HIV preventive behaviors. MANCOVA, ANCOVA and Post Hoc analyses were utilized to test for significant differences among the three groups.

RESULTS

The analyses disclosed that, compared to participants in the Lecture group, participants in the CAI group scored significantly higher on the scales measuring autoimmune deficiency syndrome (AIDS) knowledge, self-evaluative outcome motivation, and intention to practice HIV preventive behaviors with current partner. In addition, compared to the No Intervention group, the CAI group scored significantly higher on the scales measuring physical outcome motivation and social outcome motivation.

CONCLUSIONS

CAI-based programs can be effective for delivering instruction on HIV prevention. However, because of certain limitations, this type of program is best utilized as part of a more comprehensive intervention that uses several different delivery systems.

The human non-muscle alpha-actinin protein encoded by the ACTN4 gene suppresses tumorigenicity of human neuroblastoma cells

alpha-Actinins are actin-binding proteins important in organization of the cytoskeleton and in cell adhesion. We have cloned and characterized a cDNA from human neuroblastoma cell variants which encodes the second non-muscle alpha-actinin isoform designated ACTN4 (actinin-4). mRNA encoded by the ACTN4 gene, mapped to chromosome 4, is abundant in non-tumorigenic, substrate-adherent human neuroblastoma cell variants but absent or only weakly expressed in malignant, poorly substrate-adherent neuroblasts. It is also present in many adherent tumor cell lines of diverse tissue origins. Cell lines typically co-express ACTN4 and ACTN1, a second non-muscle alpha-actinin gene. Expression is correlated with substrate adhesivity. Analysis of deduced amino acid sequences suggests that the two isoforms may differ in function and in regulation by calcium. Moreover, ACTN4 exhibits tumor suppressor activity. Stable clones containing increased levels of alpha-actinin, isolated from highly malignant neuroblastoma stem cells [BE(2)-C] after transfection with a full-length ACTN4 cDNA, show decreased anchorage-independent growth ability, loss of tumorigenicity in nude mice, and decreased expression of the N-myc proto-oncogene.

Paraoxonase activity in two healthy populations with differing rates of coronary heart disease

BACKGROUND

The rate of coronary heart disease is over three-fold greater in Belfast than in Toulouse and the excess risk cannot be totally explained by 'classical' risk factors such as total cholesterol, LDL-cholesterol, smoking, etc.

DESIGN

The effect of the human serum paraoxonase (PON1) 192-genetic polymorphism on plasma lipid and lipoprotein concentrations and on PON1 activity and concentration was investigated in 186 randomly selected healthy subjects from Toulouse and 165 from Belfast.

RESULTS

The frequency of the R allele of PON1, which has been related to the risk of coronary heart disease, was significantly higher in Belfast (0.33) than in Toulouse (0.24; chi2 = 7.229, P = 0.0072). Subjects from Belfast also had significantly higher serum cholesterol, triglycerides, LDL-cholesterol, and apolipoprotein B, and significantly lower HDL-cholesterol and apolipoprotein A1, but these lipoprotein parameters were independent of the PON1 192-polymorphisms. PON1 activity towards paraoxon was significantly higher in the Belfast population than in Toulouse (median values: 179.7 vs. 129.4 nmol min-1 mL-1 serum, respectively; P < 0.05), which is consistent with our finding of a greater prevalence of the R allele. The median serum concentration of PON1 was 56.3 microgram mL-1 in Belfast, which was significantly lower (P < 0.005) than the level of 71 microgram mL-1 in Toulouse.

CONCLUSIONS

Our results thus provide further support for the hypothesis that populations at increased CHD risk have diminished serum PON1 concentration and an increased prevalence of the R allele of PON1. They are also consistent with reports that the ability of PON1 to hydrolyse paraoxon is inversely related to its capacity to hydrolyse lipid-peroxides, and thus to its antiatherogenic action.

Werner helicase expression in human fetal and adult aortas

Werner syndrome is a human progeroid syndrome caused by mutations at the Werner helicase locus (WRN). Progeroid features and diseases associated with aging (including arteriosclerosis) do not become apparent until after puberty. We entertained two alternative hypotheses to explain the post-pubertal onset: 1) WRN expression is induced at the time of puberty, its earlier functions being satisfied by another member of that family of helicases; and 2) it is expressed at all ages, but the phenotype of deficiency becomes apparent only after puberty. We report initial experiments consistent with the second hypothesis. Steady-state levels of WRN mRNA in aortic tissues were determined by semiquantitative reverse transcription-polymerase chain reaction. WRN mRNA was detectable as early as 49 days of gestation (the earliest available material). There was no statistically significant change in these levels between fetal and adult tissues. The presence of the WRN protein in fetal aorta was confirmed by Western analysis. This rules out the possibility that Werner syndrome phenotypes manifest after the puberty because of peripubertal induction of WRN expression.

Methionine synthase D919G polymorphism is a significant but modest determinant of circulating homocysteine concentrations

Elevation in plasma homocysteine concentration has been associated with vascular disease and neural tube defects. Methionine synthase is a vitamin B(12)-dependent enzyme that catalyses the remethylation of homocysteine to methionine. Therefore, defects in this enzyme may result in elevated homocysteine levels. One relatively common polymorphism in the methionine synthase gene (D919G) is an A to G transition at bp 2,756, which converts an aspartic acid residue believed to be part of a helix involved in co-factor binding to a glycine. We have investigated the effect of this polymorphism on plasma homocysteine levels in a working male population (n = 607) in which we previously described the relationship of the C677T "thermolabile" methylenetetrahydrofolate reductase (MTHFR) polymorphism with homocysteine levels. We found that the methionine synthase D919G polymorphism is significantly (P = 0.03) associated with homocysteine concentration, and the DD genotype contributes to a moderate increase in homocysteine levels across the homocysteine distribution (OR = 1.58, DD genotype in the upper half of the homocysteine distribution, P = 0.006). Unlike thermolabile MTHFR, the homocysteine-elevating effects of the methionine synthase polymorphism are independent of folate and B(12) levels; however, the DD genotype has a larger homocysteine-elevating effect in individuals with low B(6) levels. This polymorphism may, therefore, make a moderate, but significant, contribution to clinical conditions that are associated with elevated homocysteine.

Antitumor activity of CEP-751 (KT-6587) on human neuroblastoma and medulloblastoma xenografts

Neuroblastoma (NBL) and medulloblastoma (MBL) are tumors of the neuroectoderm that occur in children. NBL and MBL express Trk family tyrosine kinase receptors, which regulate growth, differentiation, and cell death. CEP-751 (KT-6587), an indolocarbazole derivative, is an inhibitor of Trk family tyrosine kinases at nanomolar concentrations. This study was designed to determine the effect of CEP-751 on the growth of NBL and MBL cell lines as xenografts. In vivo studies were conducted on four NBL cell lines (IMR-5, CHP-134, NBL-S, and SY5Y) and three MBL cell lines (D283, D341, and DAOY) using two treatment schedules: (a) treatment was started after the tumors were measurable (therapeutic study); or (b) 4-6 days after inoculation, before tumors were palpable (prevention study). CEP-751 was given at 21 mg/kg/dose administered twice a day, 7 days a week; the carrier vehicle was used as a control. In therapeutic studies, a significant difference in tumor size was seen between treated and control animals with IMR-5 on day 8 (P = 0.01), NBL-S on day 17 (P = 0.016), and CHP-134 on day 15 (P = 0.034). CEP-751 also had a significant growth-inhibitory effect on the MBL line D283 (on day 39, P = 0.031). Inhibition of tumor growth of D341 did not reach statistical significance, and no inhibition was apparent with DAOY. In prevention studies, CEP-751 showed a modest growth-inhibitory effect on IMR5 (P = 0.062) and CHP-134 (P = 0.049). Furthermore, inhibition of growth was greater in the SY5Y cell line transfected with TrkB compared with the untransfected parent cell line expressing no detectable TrkB. Terminal deoxynucleotidyl transferase-mediated nick end labeling studies showed CEP-751 induced apoptosis in the treated CHP-134 tumors, whereas no evidence of apoptosis was seen in the control tumors. Finally, there was no apparent toxicity identified in any of the treated mice. These results suggest that CEP-751 may be a useful therapeutic agent for NBL or MBL.

High-level expression of EPHB6, EFNB2, and EFNB3 is associated with low tumor stage and high TrkA expression in human neuroblastomas

Neuroblastoma (NB) is a common pediatric tumor of neural crest origin that is biologically and clinically heterogeneous. EPH family receptor tyrosine kinases and ephrin ligands play fundamental roles in neurodevelopmental processes. Recently, we found that NB cell lines expressed several EPHB and EFNB transcripts, which encode EPHB subgroup receptors and ephrin-B subgroup ligands, respectively. To explore the role of EPHB receptors and ephrin-B ligands in the biology of NB, we examined the expression of EPHB and EFNB transcripts in 47 primary NB specimens. Multiple EPHB and EFNB transcripts were expressed in all of the NB tumors examined, suggesting the involvement of these transcripts in modulating the biological behavior of NB. Higher levels of EPHB6, EFNB2, and EFNB3 expression were found in low-stage tumors (stage 1, 2, and 4S) than in advanced-stage tumors (stage 3 and 4; P = 0.0013, P = 0.0048, and P = 0.027, respectively). Expression of TrkA, a well-established prognostic marker of favorable NB, was positively correlated with EPHB6, EFNB2, and EFNB3 expression (P < 0.0001, P = 0.0019, and P = 0.0001, respectively). MYCN-amplified tumors expressed lower levels of EPHB6, EFNB2, EFNB3, and TrkA transcripts compared to nonamplified tumors (P = 0.0006, P = 0.0023, P = 0.0048, and P = 0.0001, respectively). These data suggest that high-level expression of EPHB6, EFNB2, and EFNB3 is associated with favorable NB and that low-level expression of EPHB6, EFNB2, and EFNB3 correlates with aggressive MYCN-amplified NB. Thus, EPHB6, EFNB2, and EFNB3 may have biological relevance in NB. Further investigation on the biology of these genes may help provide insight into the treatment of NB.

Chlamydia pneumoniae antibodies are associated with an atherogenic lipid profile

OBJECTIVE

To determine, within a representative population group of men and women, whether alteration of the lipid profile might underlie the reported association between Chlamydia pneumoniae and ischaemic heart disease.

DESIGN AND SETTING

Cross sectional survey in an area with a high incidence of ischaemic heart disease.

SUBJECTS

400 randomly selected participants in the World Health Organisation MONICA project's third population survey in Northern Ireland.

MAIN OUTCOME MEASURES

Stored sera were examined by microimmunofluorescence for IgG antibodies to C pneumoniae at a dilution of 1 in 64. Mean total and high density lipoprotein (HDL) cholesterol were compared between seropositive and seronegative individuals with adjustment for age, measures of socioeconomic status, smoking habit, alcohol consumption, body mass index, and the season during which blood had been taken.

RESULTS

In seropositive men, adjusted mean serum total cholesterol and HDL cholesterol were 0.5 mmol/l (9.2%) higher and 0.11 mmol/l (9.3%) lower, respectively, than in seronegative men. Differences in women did not achieve statistical significance, but both total cholesterol and HDL cholesterol were higher (3.6% and 5.8%, respectively) in seropositive than in seronegative individuals.

CONCLUSIONS

There is serological evidence that C pneumoniae infection is associated with an atherogenic lipid profile in men. Altered lipid levels may underlie the association between C pneumoniae and ischaemic heart disease.

Epidemiology of Chlamydia pneumoniae infection in a randomly selected population in a developed country

This cross-sectional study of 400 sera from a randomly selected adult population in Northern Ireland, using a microimmunofluorescence assay, demonstrated high overall seropositivity (70%) for IgG Chlamydia pneumoniae antibodies in developed populations. Seropositivity was shown to be unrelated to gender, age or smoking but there was an inverse trend between infection and educational level achieved as a measure of socio-economic status. IgG levels were also higher during the winter months suggesting seasonal variation of Chlamydia pneumoniae infection. The high prevalence of evidence of exposure to Chlamydia pneumoniae as described in this study may have implications for prevention of cardiovascular disease if further evidence conclusively determines that infection with this organism is a risk factor for cardiovascular disease.

Levels of physical activity, physical fitness and their relationship in the Northern Ireland Health and Activity Survey

The aim of the study was to describe the physical activity and physical fitness profile of the population of Northern Ireland and to explore the relationship between physical activity and physical fitness. This was a cross sectional population study using a two stage probability sample of the adult population of Northern Ireland (aged 16+). The main outcome measures were physical activity profile based on computer assisted interview. Physical fitness using estimation of VO2max by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill. We found that males were more vigorously active than females (M 21%:F 6%) with a steep gradient of decreasing activity with age: 49% (M 52%:F 46%) were regularly active up to at least moderate intensity. Males (mean predicted VO2max 44.4 mls/kg/min; 16-74 years) were fitter than females (mean predicted VO2max 34.0 mls/kg/min; 16-74 years) and while there was a decline in predicted VO2max with age, there was wide variation within each age category. There was no statistically significant relationship between current or past activity and fitness after adjustment for possible confounding factors, with the exception of a relationship between fitness and activity in males so that the difference between no activity and habitual vigorous activity in predicted VO2max was 4.4mls/kg/min (10.1%).

Dietary intake, smoking, and transient anti-gliadin antibodies

BACKGROUND

The detection of IgA anti-gliadin antibodies in adults can either be helpful in the diagnosis of coeliac disease, be persistent in subjects with normal jejunal mucosa, or occur transiently. We decided to investigate the effects of smoking, alcohol consumption, and dietary intake on the development of IgA anti-gliadin antibodies.

METHODS

Serum samples from subjects enrolled from a large Northern Ireland population sample (MONICA survey) were screened for IgA anti-endomysium and IgA anti-gliadin antibodies. All subjects with positive antibodies were invited for clinical assessment 3-4 years after the initial screening sample. During this follow-up a repeat serum sample was obtained and a jejunal biopsy performed. At enrollment in the MONICA survey, lifestyle information including smoking, alcohol consumption, and dietary intake was obtained.

RESULTS

At follow-up 13 subjects had persistent positive serology and villous atrophy, and 9 had persistent positive serology but normal jejunal histology; in 29 the serology had returned to normal, and the jejunal histology was normal There was no difference in smoking, alcohol consumption, or dietary intake between subjects with and without coeliac disease. Subjects with transient serology findings ate significantly more soda bread than the other groups (at the time of initial screening). Analysis of gliadin content of soda bread and plain white bread showed a significantly higher amount of gliadin present in soda bread.

CONCLUSIONS

Subjects with transient IgA anti-gliadin antibodies eat significantly more soda bread. The gliadin content of Irish soda bread contained a greater amount of gliadin than white bread. Eating breads with high available gliadin content may cause the appearance of anti-gliadin antibody.