4-fold higher than that of PAO1 (P = 0.0071). The mutation frequencies of both the 18A and PAO1 find more biofilm communities were also quantified during biofilm development and dispersal (12 days). The number of morphotypic variants was enumerated to compare the mutation frequency with the frequency of morphotypic variants. The initial mutation frequency for 18A biofilm on day 0 was 3.17 × 10−8 ± 4.87 × 10−8 (Fig. 5a), which was also similar to the mutation frequency of the planktonic culture (3.10 × 10−8 ± 7.53 × 10−9). The mutation frequency decreased during the initial stages of biofilm development to 6.87 × 10−9 ± 7.4 × 10−9 by day 4. On day 8, the mutation frequency increased to 2.65 × 10−8 ± 3.68 × 10−8,

and by day 10, it was 6.11 × 10−8 ± 1.14 × 10−7, similar to MLN0128 clinical trial the mutation frequency observed at the start of biofilm development and the original planktonic culture. In contrast to PAO1, morphotypic variants appeared in the biofilm of 18A on day 4 and accounted for approximately 49% of the population. On day 10, when the mutation frequency was the highest for strain 18A, approximately 80% of the population consisted of morphotypic variants. Interestingly, by day 12, variants accounted for only 20% of the population at which time the mutation frequency also declined (4.11 × 10−8 ± 3.68 × 10−8). The mutation frequency for the PAO1 biofilm on day 0 was 1.26 × 10−8 ± 9.44 × 10−9 (Fig. 5a), which was similar to the mutation

frequency of the planktonic culture. During the course of biofilm development, it was observed that the mutation frequency decreased from day 0 to day 6 (2.71 × 10−9 ± 1.20 × 10−9

on day 6) and then increased to 5.76 × 10−9 ± 3.21 × 10−9 on day 8 and did not change significantly for the remaining 4 days of the experiment. Morphotypic variants were observed in the biofilms on day 8 and constituted approximately 2% of the total PAO1 biofilm population. The peak number of variants, 12%, was observed on day 10. It was observed that the biofilm of 18A developed more slowly than that of PAO1 (Fig. 5b), Farnesyltransferase which is in accordance with our observation that 18A has a lower growth rate than PAO1 (data not shown). Although the change in mutation frequency of the biofilm community was not statistically significant between the sampling days, there appears to be a positive correlation between the mutation frequency and the variant frequency. For strain 18A, both the mutation frequency and the percentage of variants increased from days 6 to 10 and decreased on day 12. In PAO1, the mutation frequency was observed to increase slightly between days 6–12, which coincided with the emergence of morphotypic variants. Pseudomonas aeruginosa has been shown to establish long-term colonisation of the lungs of CF sufferers. This process of chronic infection has been linked to the appearance of morphotypic variants (e.g. SCVs and mucoid colony types) as well as the selection of variants with reduced overt, or acute, virulence.

In this issue, Van Roey et al. [Eur. J. Immunol. 2012. 42: 353–363] explore one of these challenges, namely to identify novel mucosal adjuvants. see more Van Roey

et al. show that the pro-allergic cytokine thymic stromal lymphopoietin (TSLP) promotes a strong B-cell response with production of secretory IgA at mucosal sites. Here, we discuss the importance and limits of these findings within the broader field of vaccine adjuvants, and the potential development of TSLP as a mucosal and B-cell adjuvant in humans. Adjuvants are critical components of vaccine formulations, required to induce an appropriate and protective immune response 1. They can be defined as molecules acting independently of an

antigen in order to directly activate innate and/or adaptive immune cells. They can promote humoral or cellular immunity, influence the cytokine polarity of T-helper (Th) cell responses, and modulate the effector T (Teff)-versus Treg-cell balance. In addition, they may promote a local or systemic immune response. Most vaccines are administered systemically, by sub-cutaneous or intra-muscular routes, and induce a systemic immune response, measured by the serum Ab titer. Circulating IgG may also contribute to the local immune response at mucosal surfaces, but with reduced efficiency as compared with secretory IgA (sIgA). Given that many pathogens are acquired through mucosal infection, efforts have been made to this website specifically induce sIgA at mucosal surfaces. To this end, the mucosal route of immunization appears to be a superior way of inducing both an imprint of adaptive immune cells 2, and the expression of homing molecules directing Teff and B cells to the mucosa

3. Currently, at least six vaccines have been approved for mucosal administration, mostly oral. These include vaccines against cholera, Salmonella typhimurium, influenza, polio virus, and rotavirus 4. Vaccine formulations contain live, attenuated, or inactivated microbial strains. The further development of mucosal vaccines is, however, limited by the lack of specific adjuvants that are necessary to promote strong mucosal immunity and the production of secretory IgA in response Cobimetinib concentration to large variety of antigens, and to avoid the risk of inducing oral tolerance 4. In the past decade, most attention in the vaccine field has been placed on innate adjuvants that trigger pattern recognition receptors, such as TLRs 5, 6. A large number of synthetic or natural TLR ligands are being explored as adjuvants in pre-clinical or clinical studies 7, 8. Although CpG oligonucleotides can be used in mucosal immunization protocols 9, this strategy has not been greatly explored. Other TLR ligands are used systemically or injected locally in tumors in order to promote innate immune activation at the site of antigenic challenge 7.

CD4−CD16+ NK cells showed upregulation of the activation marker NKG2D (Fig. 5A and MK-1775 solubility dmso D) after co-incubation with iTreg cells. While the inhibitory KIRs CD158a and CD158b were not modulated on NK cells (Fig. 5B), the expression of perforin was clearly enhanced after co-culture with iTreg cells (Fig. 5C and D). These data indicate that iTreg cells are able to activate NK cells resulting in the upregulation of NKG2D and perforin in the absence of IL-2 pre-stimulation. In summary, our findings thus far demonstrate that iTreg cells impair IL-2-mediated NK activation, provided that NK cells have no target cell contact. In contrast, target cell-induced NK

activation is enhanced by iTreg cells. In the final series

of experiments, we investigated NK activation induced by a combination of IL-2 and target cell contact. Under these conditions, NK degranulation was induced from 8 to 26% (p=0.02) compared with resting NK cells (Fig. 6). Induced Treg cells further promoted this NK cell function compared with IL-2-activated NK cells with tumors alone (from 26 to 54%; p=0.01, Fig. 6). In contrast, nTreg cells did not further modulate degranulation of IL-2-activated NK cells towards target cells. In agreement with previous reports, we found that IL-2 induces activation of primary human peripheral blood NK cells resulting in upregulation of activating receptors, NKG2D and NKp44, as well as increased degranulation and IFN-γ secretion

21, 22. These effects were significantly impaired in the presence of tumor iTreg cells, nTreg cells or TGF-β. Our results are in agreement with published Selleck Gemcitabine reports, where other types of Treg cells were described to suppress NK cell functions under various experimental conditions, in most instances in a TGF-β-dependent DOK2 manner 11, 12, 19, 23–27. Unexpectedly, we found that degranulation and the subsequent tumoricidal activity of naive NK cells were enhanced by iTreg cells. iTreg cell-enhanced cytotoxicity of NK cells was perforin- and FasLigand-dependent, while death receptor TRAIL was not involved. Consistent with the upregulation of activating receptors NKG2D and NKp44, the expression of inhibitory KIRs CD158a and CD158b on NK cells remained at basal levels in the co-culture with tumor iTreg cells. In conjunction, these data suggest that tumor iTreg cells negatively interfere with IL-2-mediated NK-cell activation, while the IL-2-independent activation of NK cells by target cell contact is augmented in the presence of iTreg cells. Importantly, the activation of NK cells by a combination of IL-2 and target cell contact is further promoted in the presence of iTreg cells. It is well established that NK cells activated by IL-2 are highly cytolytic to many tumor targets and thus NK cell-activating cytokines like IL-2 are frequently incorporated into current immunotherapeutic strategies and clinical trials 28.

Whilst modest reductions in neutrophil chemotactic and adhesive properties were observed in vitro for patients in remission, these alterations were more evident in those patients on anti-TNF-α therapy; in contrast, significant decreases in adhesion molecule presentation were more apparent

on neutrophils of patients on DMARDs and in remission. The mechanisms of action of DMARDs, including MTX, are numerous, but have been reported to involve a reduction in the production of numerous cytokines, including IL-6 and TNF-α, as well as reductions in the expression of major endothelial adhesion molecules, such as intracellular adhesion molecule-1 (ICAM-1) selleck kinase inhibitor [36]. The major mechanism of action of the anti-TNF-α agents is via the blockade of the function of this important pro-inflammatory cytokine, with an apparent consequent amelioration of the inflammatory state as a whole [37]. Whilst the different treatment regimens appear to moderately improve aspects of neutrophil adhesion and chemotaxis in a different manner, what is clear is that, in

those patients who demonstrate a significant clinical response, ameliorations in aspects important for neutrophil adhesion and chemotaxis are observed, coupled with significant improvements in neutrophilic-chemokine concentrations. Future studies may demonstrate whether these changes simply reflect the ameliorations in the inflammatory state in clinically-responding patients or whether these alterations contribute STI571 to decrease neutrophil migration to the SF, with consequent improvements in the clinical manifestations of RA. The authors

would like to thank Ana Paula T. Del Rio, Bruno S. A. Ferreira, Michel A. Yazbek, Lilian T. L. Costallat and Zoraida Sachetto for their help in the recruitment of patients for this study. We are grateful to Carla F. Franco-Penteado, Fernanda Pereira, Renata Proença-Ferreira and Ana Leda Longhini, for assistance in flow cytometry and chemotaxis assays. This work was supported by research funds from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and CNPq, Brazil. The Hematology and Hemotherapy Center, UNICAMP, forms part of the National Institute of Blood, Brazil (INCT de Sangue, CNPq/MCT/FAPESP). VMD designed and performed experiments, analysed data and wrote the manuscript; MBB provided clinical care and http://www.selleck.co.jp/products/Bortezomib.html clinical analysis of data and reviewed the manuscript; CBA, VTG and LIM performed experiments; FFC analysed data and reviewed the manuscript; NC supervised and designed the study, analysed data and wrote the manuscript. “
“High-risk variants of human papillomavirus (HPV) induce cervical cancer by persistent infection, and are regarded as the principal aetiological factor in this malignancy. The pro-inflammatory cytokine interleukin-32 (IL-32) is present at substantial levels in cervical cancer tissues and in HPV-positive cervical cancer cells.

001). Examination of sequencing

data from PCR products taken from this cohort suggests a dichotomy between the Helicobacter species identified in each group (unpublished data). Attempts to culture these organisms from adult colonic tissue have proved negative to date. We have followed the adult studies presented Talazoparib in vitro above with a retrospective examination of paediatric IBD, utilizing FISH alone to examine archival colonic tissue held in pathology storage. This small study examined distal colonic tissue from the rectum or sigmoid of 23 patients with CD, 23 with UC and 15 controls (Hansen et al., 2009). The controls had undergone colonoscopy for a variety of reasons, but their assessment demonstrated a macroscopically and microscopically normal colon. Non-pylori RGFP966 research buy Helicobacter were demonstrated

in 83% of CD patients, 87% of UC patients and 40% of controls. The IBD groups were both significantly higher in prevalence than the control cohort (P=0.013 and 0.004, respectively). The organisms seen appeared to be present within the remnants of the mucosal layer (see Fig. 2), which fits with the observations of Zhang et al. (2006). In one case, a large cloud of organisms was visualized adjacent to the colonic epithelial surface (Fig. 3). Unfortunately, the methodology in use for this study has prevented the identification of these organisms to the species level. Work is now underway to recruit children throughout Scotland during their first presentation with IBD in order to identify these organisms to the species level and culture them for use in further experiments. Keenan et al. (2008) investigated colonic mucosal DNA for Helicobacter from 100 patients in New Zealand (of whom 14 had IBD, 18 had adenomatous Thymidylate synthase polyps, 34 had no macroscopic or microscopic abnormalities, and the remaining 34 can be presumed to have other colonic pathologies including lipoma and diverticulosis,

but they are not described in detail). Biopsies were taken from up to four distinct sites (terminal ileum, caecum, transverse colon, recto-sigmoid) and PCR primers targeting the Helicobacter and Wolinella genera were utilized. Seventy of 354 biopsies were deemed positive, with 35% of patients positive in at least one site. The positivity rate was similar between sites and ranged between 17.5% (terminal ileum) and 21.5% (caecum). Analysis of sequenced product identified H. pylori in the majority of patients (n=18, 18%) and W. succinogenes in four (4%). Nine sequences did not match any in the blast database, while one was a close match to H. fennelliae. There did not appear to be any association between the presence of Helicobacter organisms and colonic disease, although this may be in part due to the low pick-up rate of non-pylori Helicobacter organisms in this study. The most recent group to offer data on Helicobacter in IBD is the French group of Laharie et al.

A variation in reactivity levels was found, with the same effector cells (effector A) showing higher

reactivity, as in the previous experiment. The results given are for the ADCC activity with NK values (reactivity without antibodies) subtracted. CD8+ selleck products cells were also tested as effector cells and, as expected, the activity without antibodies was overall at a negligible level, although with low, yet detectable ADCC activity for effector A cells and anti-HERV-H/F Gag antibodies. The results for both types of effector cells are shown in Fig. 5 both as increments where results with preimmune sera are subtracted from the results with immune sera and also as the value in folds (immune sera/preimmune sera). We find that increments are the most accurate and instructive values, as artificially increased values may result from calculating folds, when the denominator is below 1·0. The causative agent(s) initiating MS continues to evade exposure of their nature. The processes leading to cell death are also incompletely understood, although parts of the process are known, thus offering possibilities for different types of intervention in the course or the symptoms of the disease. Cytotoxicity reactions are not investigated greatly, either for the types of possible effector cells or for the antibodies/epitopes involved, although these reactions

may play a significant role in MS pathogenesis by killing CNS cells expressing the epitopes. The type of effector cells gaining most attention recently have been CD8+ T cells ABC294640 research buy rather than CD4+ T cells [14, 15], which for several years were regarded as the main participants

in the disease processes [16], due in part to extensive investigations based on the animal model of brain inflammation, experimental autoimmune encephalomyelitis (EAE). This model has some similarities but also significant differences from MS, illustrated markedly by the lack of efficacy of clinical MS trials targeting CD4+ T cells [17]. Different types of cytotoxic activities of possible significance are due to NK [18] or ADCC, both executed mainly by CD56+ cells. In particular, the latter type of Sodium butyrate cytotoxicity may be worthwhile studying, as increased production of oligoclonal antibodies against both known and unknown epitopes (including HERV and herpesvirus epitopes) is one of the characteristic and puzzling findings in MS [19-21]. For several years we have grown blood lymphocytes from MS patients in our laboratory [9]. Some of these lymphocytes, particularly when sourced from MS patients in relapse, have changed the growth pattern into continuously growing B lymphoblastoid cell cultures expressing and producing endogenous retroviruses, predominantly HERV-H/F, and also HERV-W, together with low amounts of Epstein–Barr virus proteins.

Specific cytokine-adsorbing columns have also been developed with significant removal rates of proinflammatory cytokines in animal and human sepsis [63] reflecting benefits of modulation of the cytokine profile. Sepsis is, check details however, a complex disease entity where removal of single cytokines has marginal effect on the clinical course, as reflected by the many unsuccessful studies using neutralizing antibodies to specific cytokines. The pattern and degree of the inflammatory response, however, is quite different in LDL apheresis as compared to sepsis. Generally, LDL apheresis columns seem to adsorb many proinflammatory cytokines and to some degree

seem to increase some of the anti-inflammatory cytokines, although there are differences between different LDL apheresis columns and studies vary regarding types of patients included. Furthermore, no studies have addressed how or if changes in pro- and anti-inflammatory cytokine profile in LDL apheresis relate to changes in clinical endpoints. Some data indicate that CRP could play a causative role in the pathogenesis of atherosclerosis [64, 65], but data are conflicting

and a consensus has yet to be established [66, 67]. The JUPITER trial clearly selleck kinase inhibitor demonstrated that clinical endpoints were reduced along with reductions in CRP and LDL cholesterol in healthy persons with LDL cholesterol below 3.4 mm and CRP below 2 mg/l before intervention [68]. Puntoni Carnitine palmitoyltransferase II et al. [69] found higher levels of CRP in heFH patients compared with controls, however not significantly so. Kojima et al.

[55] found a significant decrease in CRP when treating hypercholesterolemic patients with LDL apheresis. The findings were reproduced by Kobayashi et al. [58, 59] who treated patients with PAD with LDL apheresis. Herchovici et al. [70] found a significant decrease in CRP during LDL apheresis in hypercholesterolemic patients, with differences observed between the different LDL apheresis systems. Our group also noted a significant decrease in CRP during LDL apheresis in heFH [46]. Thus, it seems that most LDL apheresis treatments reduce the inflammatory marker CRP, a factor that could be of pathogenetic importance in subjects prone to atherosclerosis. Lowering of CRP is associated with lowering of clinical end points [68], but it remains to be proven if reduction of CRP in LDL apheresis relates to reduction in endpoints. Fibrinogen, the precursor of fibrin, is associated with risk for cardiovascular disease [71]. Wang et al. [57] found a significant decrease in fibrinogen during LDL apheresis in patients with CAD, a finding that was confirmed by Kobayashi et al. [59] performing LDL apheresis on patients with peripheral artery disease. Otto et al. [56] found a decrease in fibrinogen levels for two types of LDL apheresis in whole blood. Our group compared three different LDL apheresis techniques and found significant decreases in fibrinogen for all columns [72].

The RNA concentration and purity was measured by a spectrophotometer (ND-1000; NanoDrop Technologies Inc.). Reverse transcription was performed with TaqMan reverse transcription reagents (Applied Biosystems). Quantitative PCR was performed using StepOnePlus instrumentation (Applied NVP-BEZ235 price Biosystems) with TaqMan Fast Universal PCR Master Mix and predesigned FAM-labelled gene expression assay reagents (Applied Biosystems). Selected cytokines and transcription factors were IL-17A (cat. no. Hs00174383_m1), FoxP3 (Hs00203958_m1), RORc (cat. no. Hs01076112_m1) and IFN-γ (Hs00174143_m1). Ribosomal 18 s RNA served as the endogenous control (Hs99999901_s1). The quantities of target gene

expression were analysed by a comparative threshold cycle (Ct) method (as recommended by Applied Biosystems). An exogenous cDNA pool calibrator was collected from phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) and considered as an interassay standard to which normalized samples were compared. ΔCt stands for the difference between the Ct of the marker gene and Ct of the 18S gene, whereas ΔΔCt is the difference between the ΔCt of the sample and ΔCt of the calibrator. Calculation of 2−ΔΔCt then gives the relative amount of target gene in the sample compared with the calibrator, both normalized XL765 nmr to

an endogenous control (18S). For presentations the relative amounts (2−ΔΔCt) of target genes were multiplied by a factor 1000 and expressed as relative units. If the samples Ct value for target gene did not reach quantitative Resminostat level, then an artificial value that was half the lowest quantitative value in relative units was given to the sample. We cultured small intestinal biopsy samples from 23 patients with untreated CD (of which six also had T1D) and 10 reference children (five positive for TGA) for 72 h in RPMI-5% human AB serum and measured the concentration

of IL-17, Il-1β and IL-6 secreted in the culture supernatants by using flow-cytometric bead array (Bender Medsystems, Vienna, Austria). Samples below the detection limit (or the cut-off level) of the method were considered as undetectable, but were given half the cut-off value to enable statistical analyses. The human colon adenocarcinoma cell line (CaCo-2) was obtained from American Type Culture Collection (ATCC) (Teddington, UK). Cells were grown in Eagle’s minimal essential medium (Sigma) containing 10% heat-activated and sterile filtered fetal bovine serum (FBS) supplemented with penicillin (0·1 g/l) and streptomycin (0·15 g/l) at + 37°C and 5% CO2. CaCo-2 cells were grown in a 75 cm2 flask for 6 days and were thereafter plated into sterile 48-well plates (Greiner Bio-One GmbH, Frickenhausen, Germany) and grown for 4 days at a density of 1·5 × 105 cells per well and a final volume of 0·5 ml/well. The cells were incubated for 5 h with recombinant human IL (rhIL)-17 (1 or 50 pg/ml; cat. no.

2% fresh sodium azide. After incubation, cells were washed three times in an FACS buffer, transferred into PCR tubes, and cooled down to 4°C on a PCR machine. Tetramer decay was initiated by adding a saturating amount of anti-HLA-A2 antibody (clone BB7.2, GeneTex, 50 μg/mL). At various time points, an aliquot of

cells was fixed in 4% paraformaldehyde (Electron Microscopy Sciences) in a V-bottom 96-well plate. A control experiment was performed at the same time where no anti-HLA-A2 antibody was added. The samples were analyzed on an LSR II Flow Cytometer equipped with a plate reader (BD Biosciences). The data were gated for live cells based on front and side scattering and plotted as MFI (mean fluorescent intensity) versus time and fitted with a single exponential decay function in OriginPro (OriginLab). 1 × 105 hybridoma cells expressing gp209-specific TCRs and 1 × 105 T2 cells were www.selleckchem.com/products/MK-1775.html mixed in a 96-well U-bottom plate

with various concentrations of gp209–2M peptide in a total volume of 200 μL for each well and incubated overnight at 37°C, 5% CO2. IL-2 production was quantified by standard sandwich ELISA. Antibody pairs (anti-mouse IL-2/biotinylated anti-mouse IL-2) and IL-2 standards were from XL765 eBioscience. Streptavidin-HRP was from BD Biosciences and tetramethylbenzidine ELISA substrate was from Sigma. The 2D effective affinity and the average number of bonds/pMHC density (/mpMHC) were measured with micropipette adhesion frequency pentoxifylline assay at room temperature [34]. Experiments were performed in L15 media supplemented with 5 mM HEPES/1% BSA [27]. Briefly, a pMHC-coated RBC and a hybridoma cell were gently aspirated by two opposing micropipettes. The RBC was driven by a piezoelectric translator connected to the micropipette to make a soft contact with the T cell for varying durations of time (tc, ranging from 0.1–10 s) and then retracted. During retraction, adhesion, if present,

was visualized by the stretch of the RBC membrane. Adhesion frequency (Pa) is defined as the number of adhesion events divided by the total number of contacts (50 touches for each individual hybridoma cell–RBC pair). For each contact time, adhesion frequencies from —two to six cell pairs (depending on cellular variability) were used to obtain mean ± SEM of Pa. For TCR–pMHC or pMHC–CD8 bimolecular interaction, the effective affinity is calculated using equilibrium adhesion frequency (the plateau level on a Pa versus tc plot) by (1) The average number of bonds () per pMHC density, or normalized adhesion bonds, is calculated by (2) It follows from Eqs. (1) and (2) that /mpMHC = AcKamr for bimolecular interaction. However, /mpMHC can also be used as a metric for trimolecular interaction and interactions mediated by multiple receptor-ligand species [34]. The 2D off-rates of TCR–pMHC and pMHC–CD8 bonds were measured by thermal fluctuation assay with a BFP at room temperature [38].

Finally, we have shown that mothers with anti-Ro and/or anti-La antibodies and hypothyroidism with or without other clinical autoimmune disease are at a ninefold increased risk of having an affected foetus Ulixertinib mw compared with sera-positive mothers without hypothyroidism [27]. The prevalence of anti-Ro and anti-La antibodies in women with hypothyroidism, however, remains unclear. Most pregnancies complicated by maternal immune-mediated AVB are detected prior to delivery, and many within the midtrimester.

The diagnosis of maternal autoimmune-mediated AVB is usually confirmed by foetal echocardiography before birth and by electrocardiography after birth. All of the echocardiographic

techniques used to document the presence of foetal AVB rely on the association between mechanical (flow or wall motion) atrial and ventricular events from which electrophysiological events are inferred. These techniques include simultaneous spectral Doppler Sirolimus mw interrogation of left ventricular inflow and outflow, the superior vena cava and ascending aorta or a pulmonary artery and pulmonary vein, and simultaneous m-mode or tissue Doppler interrogation of atrial and ventricular wall motion. These techniques are further described in the paper of Sonesson within the current journal issue [28]. Foetal magnetocardiography, which provides tracings that represent the magnetic analogue of a foetal electrocardiogram, is probably the most accurate technique for the evaluation of foetal AVB [29, 30]; however, the expense of this device and PRKACG the need for a magnetically shielded space have precluded its use in most foetal programmes. First-degree AVB is typically

diagnosed in the presence of prolonged interval between atrial contraction and ventricular contraction (the ‘A–V’ interval) in the presence of normal atrial and ventricular rates and consistent 1:1 atrial and ventricular relationship. Use of recently published normative data for A–V intervals measured from the different techniques facilitates the detection of first-degree AVB among screened antibody-positive mothers [31]. Higher grades of AVB are usually suspected when there is intermittent or persistent foetal bradycardia. A diagnosis of second-degree AV block is made when there are intermittent episodes of AVB, or occasional beats with lack of atrioventricular conduction, and for beats with atrioventricular conduction there is typically a prolonged A–V interval, the latter in keeping with first-degree AVB caused by AV nodal disease. Finally, in the most severe form, complete AVB is associated with complete dissociation between atrial and ventricular events.