CARD9 deficiency with allergic bronchopulmonary aspergillosis (ABPA)-like presentation: a case report

PURPOSE

We present a patient with CARD9 deficiency and allergic bronchopulmonary aspergillosis (ABPA)-like presentation.

METHODS

Following medical history taking and routine laboratory investigations, an inborn error of immunity was suspected, and the responsible variant was identified using Whole Exome Sequencing and confirmed by Sanger sequencing.

RESULTS

A 14-year-old Iranian female presented with a history of chest pain, productive cough, dyspnea, malaise, and recurrent fever. Imaging by computed tomography (CT scan), chest X-ray (CXR), bronchoscopy, transbronchial lung biopsy (TBLB), and histopathology findings led to a diagnosis of ABPA-like presentation. The genetic study showed an autosomal recessive homozygous mutation in the CARD9 gene. Clinical remission was achieved following the administration of voriconazole, which was continued as prophylaxis.

CONCLUSIONS

This is the first-time report of a patient with inherited CARD9 deficiency and ABPA-like presentation due to Aspergillus Terrus. This study paves the way to elucidate immunological mechanisms underlying CARD9 deficiency and aspergillosis.

Discovering cellular programs of intrinsic and extrinsic drivers of metabolic traits using LipocyteProfiler

A primary obstacle in translating genetic associations with disease into therapeutic strategies is elucidating the cellular programs affected by genetic risk variants and effector genes. Here, we introduce LipocyteProfiler, a cardiometabolic-disease-oriented high-content image-based profiling tool that enables evaluation of thousands of morphological and cellular profiles that can be systematically linked to genes and genetic variants relevant to cardiometabolic disease. We show that LipocyteProfiler allows surveillance of diverse cellular programs by generating rich context- and process-specific cellular profiles across hepatocyte and adipocyte cell-state transitions. We use LipocyteProfiler to identify known and novel cellular mechanisms altered by polygenic risk of metabolic disease, including insulin resistance, fat distribution, and the polygenic contribution to lipodystrophy. LipocyteProfiler paves the way for large-scale forward and reverse deep phenotypic profiling in lipocytes and provides a framework for the unbiased identification of causal relationships between genetic variants and cellular programs relevant to human disease.

Transcriptome and fatty-acid signatures of adipocyte hypertrophy and its non-invasive MR-based characterization in human adipose tissue

Background

The adipocyte-hypertrophy associated remodeling of fat cell function is considered causal for the development of metabolic disorders. A better understanding of transcriptome and fatty acid (FA) related alterations with adipocyte hypertrophy combined with less-invasive strategies for the detection of the latter can help to increase the prognostic and diagnostic value of adipocyte size and FA composition as markers for metabolic disease.

Methods

To clarify adipocyte-hypertrophy associated transcriptomic alterations, fat cell size was related to RNA-Seq data from white adipose tissue and size-separated adipocytes. The relationship between adipocyte size and adipose tissue FA composition as measured by GC-MS was investigated. MR spectroscopy (MRS) methods for clinical scanning were developed to characterize adipocyte size and FA composition in a fast and non-invasive manner.

Findings

With enlarged adipocyte size, substantial transcriptomic alterations of genes involved in mitochondrial function and FA metabolism were observed. Investigations of these two mechanisms revealed a reciprocal relationship between adipocyte size and estimated thermogenic adipocyte content as well as depot-specific correlations of adipocyte size and FA composition. MRS on a clinical scanner was suitable for the in-parallel assessment of adipose morphology and FA composition.

Interpretation

The current study provides a comprehensive overview of the adipocyte-hypertrophy associated transcriptomic and FA landscape in both subcutaneous and visceral adipose tissue. MRS represents a promising technique to translate the observed mechanistic, structural and functional changes in WAT with adipocyte hypertrophy into a clinical context for an improved phenotyping of WAT in the context of metabolic diseases.

Funding

Competence network for obesity (FKZ 42201GI1128), ERC (No 677661, ProFatMRI; No 875488, FatVirtualBiopsy), Else Kröner-Fresenius-Foundation.

A single-cell atlas of human and mouse white adipose tissue

White adipose tissue, once regarded as morphologically and functionally bland, is now recognized to be dynamic, plastic and heterogenous, and is involved in a wide array of biological processes including energy homeostasis, glucose and lipid handling, blood pressure control and host defence1. High-fat feeding and other metabolic stressors cause marked changes in adipose morphology, physiology and cellular composition1, and alterations in adiposity are associated with insulin resistance, dyslipidemia and type 2 diabetes2. Here we provide detailed cellular atlases of human and mouse subcutaneous and visceral white fat at single-cell resolution across a range of body weight. We identify subpopulations of adipocytes, adipose stem and progenitor cells, vascular and immune cells and demonstrate commonalities and differences across species and dietary conditions. We link specific cell types to increased risk of metabolic disease and provide an initial blueprint for a comprehensive set of interactions between individual cell types in the adipose niche in leanness and obesity. These data comprise an extensive resource for the exploration of genes, traits and cell types in the function of white adipose tissue across species, depots and nutritional conditions.

Iron as the concert master in the pathogenic orchestra playing in sporadic Parkinson's disease

About 60 years ago, the discovery of a deficiency of dopamine in the nigro-striatal system led to a variety of symptomatic therapeutic strategies to supplement dopamine and to substantially improve the quality of life of patients with Parkinson's disease (PD). Since these seminal developments, neuropathological, neurochemical, molecular biological and genetic discoveries contributed to elucidate the pathology of PD. Oxidative stress, the consequences of reactive oxidative species, reduced antioxidative capacity including loss of glutathione, excitotoxicity, mitochondrial dysfunction, proteasomal dysfunction, apoptosis, lysosomal dysfunction, autophagy, suggested to be causal for ɑ-synuclein fibril formation and aggregation and contributing to neuroinflammation and neural cell death underlying this devastating disorder. However, there are no final conclusions about the triggered pathological mechanism(s) and the follow-up of pathological dysfunctions. Nevertheless, it is a fact, that iron, a major component of oxidative reactions, as well as neuromelanin, the major intraneuronal chelator of iron, undergo an age-dependent increase. And ageing is a major risk factor for PD. Iron is significantly increased in the substantia nigra pars compacta (SNpc) of PD. Reasons for this finding include disturbances in iron-related import and export mechanisms across the blood-brain barrier (BBB), localized opening of the BBB at the nigro-striatal tract including brain vessel pathology. Whether this pathology is of primary or secondary importance is not known. We assume that there is a better fit to the top-down hypotheses and pathogens entering the brain via the olfactory system, then to the bottom-up (gut-brain) hypothesis of PD pathology. Triggers for the bottom-up, the dual-hit and the top-down pathologies include chemicals, viruses and bacteria. If so, hepcidin, a regulator of iron absorption and its distribution into tissues, is suggested to play a major role in the pathogenesis of iron dyshomeostasis and risk for initiating and progressing ɑ-synuclein pathology. The role of glial components to the pathology of PD is still unknown. However, the dramatic loss of glutathione (GSH), which is mainly synthesized in glia, suggests dysfunction of this process, or GSH uptake into neurons. Loss of GSH and increase in SNpc iron concentration have been suggested to be early, may be even pre-symptomatic processes in the pathology of PD, despite the fact that they are progression factors. The role of glial ferritin isoforms has not been studied so far in detail in human post-mortem brain tissue and a close insight into their role in PD is called upon. In conclusion, "iron" is a major player in the pathology of PD. Selective chelation of excess iron at the site of the substantia nigra, where a dysfunction of the BBB is suggested, with peripherally acting iron chelators is suggested to contribute to the portfolio and therapeutic armamentarium of anti-Parkinson medications.

Linking the FTO obesity rs1421085 variant circuitry to cellular, metabolic, and organismal phenotypes in vivo

Variants in FTO have the strongest association with obesity; however, it is still unclear how those noncoding variants mechanistically affect whole-body physiology. We engineered a deletion of the rs1421085 conserved cis-regulatory module (CRM) in mice and confirmed in vivo that the CRM modulates Irx3 and Irx5 gene expression and mitochondrial function in adipocytes. The CRM affects molecular and cellular phenotypes in an adipose depot-dependent manner and affects organismal phenotypes that are relevant for obesity, including decreased high-fat diet-induced weight gain, decreased whole-body fat mass, and decreased skin fat thickness. Last, we connected the CRM to a genetically determined effect on steroid patterns in males that was dependent on nutritional challenge and conserved across mice and humans. Together, our data establish cross-species conservation of the rs1421085 regulatory circuitry at the molecular, cellular, metabolic, and organismal level, revealing previously unknown contextual dependence of the variant's action.

Adherence to infliximab therapy in inflammatory bowel disease patients in a real-life setting

OBJECTIVE

To assess adherence to infliximab (IFX) therapy in inflammatory bowel disease patients, to investigate reasons for non-adherence and to identify predictors for non-adherence.

METHODS

This observational study was conducted in two French referral university hospitals between 1 September and 31 October, 2011. Patients were systematically asked if they had already delayed or missed an IFX perfusion since the beginning of the treatment and about the reasons for their non-adherence.

RESULTS

Of the 162 included patients (121 Crohn's disease [CD], 41 ulcerative colitis), 87 (53.7%) reported a delay of at least one IFX injection and 14 (8.6%) missed at least one IFX perfusion since the beginning of the treatment. The overall non-adherence rate was 54.3%. Pooling all misses, the main reasons for non-adherence were pregnancy (33.3%), intentional non-adherence (20%) and forgetfulness (13.3%). Pooling all delays, the main reasons for non-adherence were professional constraints (46.9%), infections (17.3%) and travels (14.3%). Perineal disease was associated with IFX delays (P = 0.0007, odds ratio 4.0), whereas active CD/UC was associated with IFX misses (P = 0.0258, OR = 5.4).

CONCLUSIONS

The overall non-adherence rate for IFX use was 54.3%. Professional constraints and intentional non-adherence were the leading causes of non-adherence. Perineal disease and active CD were negatively related to adherence.

Lewy Bodies: A Spectator or Salient Killer?

Lewy bodies (LBs) are characteristic hallmarks of Parkinson's disease (PD). However, their role in the pathology of PD is not established yet. Are they primary events in the neurodegenerative process or only secondary phenomena? Are they signs of protecting neurons from toxicity or are they toxic per se? How are they are formed? Are LBs targets for therapeutic strategies? Addressing these questions may be of pivotal importance to unravel the basic mechanisms of neurodegeneration in PD. On the basis of current evidence, we intend to elucidate the possible role of LBs as triggers and/or markers of disease progression in PD. We present evidence for the morphogenesis of brain stem and cortical LBs, the role in neuronal cell death mechanisms, which seem to be correlated with the adhesion of LBs to and finally disruption of their inner neuronal membrane. Taken as such, LBs would be salient killers of nerve cells. However, they may also play a neuroprotective role in the early phases of neuronal pathology (LBs as a spectator), yet harmful to neuronal stability in later stages of LB development. Generation of LB pathology in the periphery (early subclinical Braak stage) might be due to reactive oxygen species (ROS) due to (chronic) bacteria-induced and/or otherwise intestinal inflammation, both leading to alpha-synuclein structural changes, oligomerization, seeding and propagation in a prion-like mechanism. If so, LB generation is a secondary process following ROS/inflammation pathology. Therapeutic implication based on LB pathology include drug development to inhibit protein misfolding, templating and transmission or vaccination against LBs, neuron regeneration strategies, anti-inflammatory and anti-biotic drugs as well as nutritional specialities to prevent intestine intoxications. In conclusion, evidence suggests LBs to be secondary hallmarks of PD pathology, induced by ROS/inflammation or other pathological triggers able to modify protein (alpha-synuclein) steric/chemical properties. Therapeutic strategies based on LB pathologies are devoted to reduce neuron cell death mechanisms in their time course and severity.

Histological and histochemical analysis of the gastrointestinal tract of the common pipistrelle bat (Pipistrellus pipistrellus)

Bats have a very high mass-specific energy demand due to small size and active flight. European bat species are mostly insectivorous and the morphology of the gastrointestinal tract should be adapted accordingly. This study investigated the general anatomy by histology and the function by analysing carbohydrate distribution in particular of the mucus of the GI tract of the insectivorous bat Pipistrellus pipistrellus. The GI tracts of three individuals were dissected, fixed in formaldehyde, and embedded in paraffin wax. The tissues and cells of the GI tract of P. pipistrellus were analysed by classical (Acid Alizarin Blue, Haematoxylin-Eosin, and Masson Goldner Trichrome), histochemical (periodic acid-Schiff, Alcian blue at pH 2.5) and lectin histochemical (lectins WGA and HPA) staining procedures. The GI tract of P. pipistrellus was organised into the typical mammalian layers. The short, narrow, and thin-walled esophagus was simple with a folded stratified squamous epithelium without glands but mucous surface cells secreting neutral mucus. The stomach was globular shaped without specialisation. Mucous surface cells produced neutral mucus whereas neck and parietal cells secreted a mixture of neutral and acid mucus. Chief cell surface was positive for N-acetylglucosamine and the cytoplasm for N-acetylgalactosamine residues. The intestine lacked a caecum and appendix. The small intestine was divided into duodenum, jejunum‑ileum and ileum‑colon. The epithelium consisted of columnar enterocytes and goblet cells. The large intestine was short, only represented by the descending colon-rectum. It lacked villi and the mucosa had only crypts of Lieberkühn. Towards the colon-rectum, goblet cells produced mucus with N-acetylglucosamine residues increasing in acidity except in colon-rectum where acidity was highest in the base of crypts. Along the tube the surface of enterocytes was positive for N-acetylglucosamine and N-acetylgalactosamine. All over the mucus filling the lumen of the GI tract was positive for N-acetylglucosamine and increased in acidity in all parts except of the stomach. In conclusion, the simple GI tract showed an anatomical reduction of tissue enabling for a short retention time and a reduction of the load carried during flight: short GI tract, lack of lymphoid tissue, missing of glands in certain regions, and a distinct pattern of mucus distribution, indicating different physiological functions of these areas. The GI tract of P. pipistrellus was typical for an insectivorous species probably representing the ancestral condition.

Changes in the expression of genes related to neuroinflammation over the course of sporadic Alzheimer's disease progression: CX3CL1, TREM2, and PPARγ

The role of neuroinflammation in the pathogenesis of neurodegenerative diseases has become more evident in recent years. Research on the etiology and pathogenesis of sporadic Alzheimer's disease (AD) has focused on the role of chemokines such as CX3CL1, on the triggering receptors expressed by myeloid cells (TREMs), especially TREM2, and on the transcription factor/nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARγ). Here we analyzed the expression levels of CX3CL1, TREM2, and PPARγ in tissue homogenates from human brain regions that have different degrees of vulnerability to neuropathological AD-related changes to obtain insights into the pathogenesis and progression of AD. We found that CX3CL1 and TREM2, two genes related to neuroinflammation, are more highly expressed in brain regions with pronounced vulnerability to AD-related changes, such as the hippocampus, and that the expression levels reflect the course of the disease, whereas regions with low vulnerability to AD, seemed generally less affected by neuroinflammation. Furthermore, our results support previous findings of significantly higher CX3CL1 plasma levels in patients with mild to moderate AD than in patients with severe AD. Thus, CX3CL1 should be considered as promising additional marker for the early diagnosis of AD and underlines once more, the involvement of the neuroinflammation in the pathogenesis of this neurodegenerative disease.

Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report

Serological tests for immunoglobulin G4 (IgG4) against foods are persistently promoted for the diagnosis of food-induced hypersensitivity. Since many patients believe that their symptoms are related to food ingestion without diagnostic confirmation of a causal relationship, tests for food-specific IgG4 represent a growing market. Testing for blood IgG4 against different foods is performed with large-scale screening for hundreds of food items by enzyme-linked immunosorbent assay-type and radioallergosorbent-type assays in young children, adolescents and adults. However, many serum samples show positive IgG4 results without corresponding clinical symptoms. These findings, combined with the lack of convincing evidence for histamine-releasing properties of IgG4 in humans, and lack of any controlled studies on the diagnostic value of IgG4 testing in food allergy, do not provide any basis for the hypothesis that food-specific IgG4 should be attributed with an effector role in food hypersensitivity. In contrast to the disputed beliefs, IgG4 against foods indicates that the organism has been repeatedly exposed to food components, recognized as foreign proteins by the immune system. Its presence should not be considered as a factor which induces hypersensitivity, but rather as an indicator for immunological tolerance, linked to the activity of regulatory T cells. In conclusion, food-specific IgG4 does not indicate (imminent) food allergy or intolerance, but rather a physiological response of the immune system after exposition to food components. Therefore, testing of IgG4 to foods is considered as irrelevant for the laboratory work-up of food allergy or intolerance and should not be performed in case of food-related complaints.

Patterns of food allergen-specific cytokine production by T lymphocytes of children with multiple allergies

BACKGROUND

The contribution of different T cell subsets to the overall measured cytokine response to food allergens is largely unexplored.

METHOD

The patterns of cytokine production of peripheral blood-derived T cells after allergen stimulation were studied in 22 children with multiple food allergies and in 20 non-allergic children as controls, using flow cytometry.

RESULTS

Proportions of T cells of food-sensitized children spontaneously secreting IFN-gamma and IL-10 (without antigen stimulation) were lower than non-atopic children and adult controls (P<or=0.001). The proportions of IL-4-producing cells in vitro were significantly increased (P<or=0.04) and IFN-gamma-producing cells were significantly reduced (P<or=0.05) in sensitized children after incubation with and without dendritic cell presentation of peanut extract, beta-lactoglobulin and ovalbumin. The reverse pattern was found in non-sensitized children and adult controls. IL-4 secretion in allergic children to sensitizing allergens was mainly restricted to the CD4(+) CD45 RO(+) population while in non-atopic controls both CD4(+) and CD8(+) CD45 RO(+) cells produced mostly IFN-gamma. Food-specific IgE values did not correspond with cytokine responses but IL-4 production and IFN-gamma reduction relative to normal children were closely associated with total IgE levels.

CONCLUSION

Food-allergic children's IL-4 cytokine response to their relevant allergens is predominantly from a memory population of CD4(+) CD45 RO(+) cells, whereas IL-4 and IFN-gamma secretion of non-allergic controls was predominantly from mixed CD4(+) and CD8(+) CD45 RO(+) populations.

Epicutaneous exposure to peanut protein prevents oral tolerance and enhances allergic sensitization

BACKGROUND

Food allergies are an important cause of life-threatening hypersensitivity reactions. Oral tolerance can be considered the default immune response to dietary antigens, with immune deviation resulting in allergic sensitization. However, primary sensitization to food allergens may not solely be through the gastrointestinal mucosa, as strong T-helper type 2 (Th2)-biased immunity can result from exposure to protein allergens on barrier-disrupted skin.

OBJECTIVE

The purpose of this study was to examine whether exposure to allergens through the skin may interfere with the normal development of oral tolerance and promote allergic sensitization to food proteins.

METHODS

Female BALB/c mice were exposed epicutaneously to peanut protein and induction of systemic oral tolerance through high dose feeds of peanut protein was subsequently assessed. Other mice were rendered tolerant prior to epicutaneous peanut exposure. Sensitivity to peanut was determined by assessing delayed-type hypersensitivity, proliferative, cytokine and antibody responses.

RESULTS

Epicutaneous exposure to peanut protein induced potent Th2-type immunity with high levels of IL-4 and serum IgE. Primary skin exposure prevented the subsequent induction of oral tolerance to peanut in an antigen-specific manner. Upon oral challenge, mice became further sensitized and developed strong peanut-specific IL-4 and IgE responses. Furthermore, animals with existing tolerance to peanut were partly sensitized following epicutaneous exposure.

CONCLUSION

Epicutaneous exposure to peanut protein can prevent induction of oral tolerance, and may even modify existing tolerance to peanut. Epidermal exposure to protein allergens selectively drives Th2-type responses, and as such may promote sensitization to food proteins upon gastrointestinal exposure.

Adjunctive Therapy with Pramlintide Lowers HbA1c without Concomitant Weight Gain and Increased Risk of Severe Hypoglycemia in Patients with Type 1 Diabetes Approaching Glycemic Targets

AIMS

In long-term clinical trials in patients with type 1 diabetes spanning a wide range of HbA1c, addition of pramlintide to existing insulin regimens led to reductions in HbA1c that were accompanied by weight loss and no increase in overall severe hypoglycemia event rates. Given that weight gain and increased hypoglycemia risk contribute to the difficulty of attaining HbA1c targets (<7 %), the question arose whether pramlintide could benefit patients approaching, but not reaching glycemic targets with insulin alone. To address this question, we conducted a pooled analysis from 3 long-term clinical trials, including all patients with an entry HbA1c between 7.0 % and 8.5 %.

METHODS

Within the subset of patients with an entry HbA1c between 7.0 % and 8.5 % (approximately 28 % of all patients enrolled in the 3 studies), 196 were treated with placebo + insulin (baseline HbA1c 7.9+/-0.4 %, body weight 76.0+/-14.3 kg [mean+/-SD]) and 281 with pramlintide+insulin (baseline HbA1c 7.9+/-0.4 %, body weight 75.4+/-13.1 kg). Endpoints included placebo-corrected changes from baseline to week 26 in HbA1c, body weight, and the event rate of severe hypoglycemia.

RESULTS

Adjunctive therapy with pramlintide resulted in significant reductions in HbA1c and body weight from baseline to week 26 (0.3 % and 1.8 kg, placebo-corrected treatment differences, respectively, both p<or=0.0009). These changes occurred without an increase in the overall risk of severe hypoglycemia (1.40 pramlintide vs. 1.86 placebo, events/patient-year of exposure).

CONCLUSIONS

Addition of pramlintide to insulin therapy may help patients with type 1 diabetes who are approaching, but not yet reaching, glycemic targets with insulin alone to achieve further reductions in HbA1c without concomitant weight gain and increased risk of severe hypoglycemia.

Effect of pramlintide on satiety and food intake in obese subjects and subjects with type 2 diabetes

AIMS/HYPOTHESIS

Long-term trials in insulin-treated subjects with type 2 diabetes have shown that adjunctive treatment with the amylin analogue pramlintide reduces HbA(1)c levels and elicits weight loss. While amylin reduces food intake in rodents, pramlintide's effect on satiety and food intake in humans has not yet been assessed.

METHODS

In this randomised, double-blind, placebo-controlled crossover study, 11 insulin-treated men with type 2 diabetes (age 60+/-9 years, BMI 28.9+/-4.8 kg/m(2)) and 15 non-diabetic obese men (age 41+/-21 years, BMI 34.4+/-4.5 kg/m(2)) underwent two standardised meal tests. After fasting overnight, subjects received single subcutaneous injections of either pramlintide (120 microg) or placebo, followed by a preload meal. After 1 h, subjects ate an ad libitum buffet meal. Energy intake and meal duration were measured, as were hunger ratings (using visual analogue scales), and plasma cholecystokinin, glucagon-like peptide-1 and peptide YY concentrations over time.

RESULTS

Compared with placebo, pramlintide reduced energy intake in both the type 2 diabetes (Delta-202+/-64 kcal, -23+/-8%, p<0.01) and obese (Delta-170+/-68 kcal, -16+/-6%, p<0.02) groups, without affecting meal duration. Hunger and hormonal analyte profiles provided evidence that pramlintide may exert a primary satiogenic effect, independently of other anorexigenic gut peptides.

CONCLUSIONS/INTERPRETATION

The results indicate that enhanced satiety and reduced food intake may explain the weight loss observed in long-term pramlintide trials.

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention.

AIM

To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls.

METHODS

A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies.

RESULTS

A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes.

CONCLUSIONS

IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Oral administration of bovine whey proteins to mice elicits opposing immunoregulatory responses and is adjuvant dependent

Most studies investigating the induction of oral tolerance (OT) use purified proteins such as ovalbumin (OVA), bovine serum albumin (BSA) and beta-lactoglobulin (beta-LG). Little information is available regarding the induction of OT to a protein mixture, e.g. cow's milk. In this study we compared the regulatory mechanisms induced after the oral administration of a whey protein concentrate (WP) derived from cow's milk following immunization with two different adjuvants, complete Freund's adjuvant (CFA) and alum. OVA was used as a control antigen. Animals were given a single feed of these proteins at an equivalent dose of 1 mg/g body weight before they were immunized seven days later with the antigen in Freund's adjuvant or alum. Delayed type hypersensitivity (DTH) responses were suppressed by both a feed of WP and OVA after immunization with CFA. However, only OVA feeding suppressed antigen specific IgG responses. In an attempt to investigate whether WP would tolerize the more susceptible IgE responses, alum immunization replaced CFA as the adjuvant used for systemic immunizations. WP, after a single feed, significantly primed for DTH and IgE responses indicating oral sensitization to WP. In contrast, OVA suppressed DTH, IgE and IgG responses. Antigen specific proliferation of mononuclear cells was suppressed in mice fed OVA, but primed in those fed with WP. In addition cells taken from sensitized mice fed WP up-regulated levels of specific interleukin (IL) -4, -10 and -12 in vitro whereas these cytokines were suppressed in cultures from tolerant WP fed mice. Global suppression was obtained in cultures from tolerant OVA fed mice. TGF-beta was not detected in draining PLN cell cultures of either tolerant or sensitized mice. These data suggest that a whey protein mixture induces divergent responses following immunization with either CFA or alum despite being fed at an identical dose. We suggest that that the choice of the adjuvant may determine the immunoregulatory outcome and this is also reflected by the systemic cytokine profile.

Effect of pramlintide on A1C and body weight in insulin-treated African Americans and Hispanics with type 2 diabetes: a pooled post hoc analysis

An unresolved problem in the management of type 2 diabetes is that improvement of glycemic control with insulin, insulin secretagogues, and insulin sensitizers is often accompanied by undesired weight gain. This problem is of particular concern in ethnic groups with a high propensity for diabetes and obesity, such as African Americans and Hispanics. Two 1-year, randomized, double-blind, placebo-controlled clinical trials in insulin-treated patients with type 2 diabetes have shown that adjunctive therapy with pramlintide, an analog of the human beta-cell hormone amylin, reduces A(1C) with concomitant weight loss, rather than weight gain. To assess the effect of pramlintide in various ethnic groups with type 2 diabetes using insulin, we conducted a pooled post hoc analysis of the 2 trials, which included all Caucasian (n = 315), African American (n = 47), and Hispanic (n = 48) patients (age 57 years, A(1C) 9.1%, body mass index [BMI] 33 kg/m(2), mean values) who completed 52 weeks of treatment with either pramlintide (120 microg twice daily or 150 microg 3 times a day) or placebo. Primary endpoints included changes from baseline to week 52 in A(1C) and body weight. Collectively, pramlintide-treated patients achieved significant reductions from baseline in both A(1C) and body weight (placebo-corrected treatment effects at week 52: -0.5% and -2.6 kg, respectively, both P <.0001). The simultaneous reduction in A(1C) and body weight at week 52 was evident across all 3 ethnic groups and appeared to be most pronounced in African Americans (-0.7%, -4.1 kg), followed by Caucasians (-0.5%, -2.4 kg) and Hispanics (-0.3%, -2.3 kg). The glycemic improvement with pramlintide was not associated with an increased incidence of hypoglycemia over the entire study period (43% pramlintide v 40% placebo). Nausea, the most common adverse event associated with pramlintide treatment, was mostly mild and confined to the first 4 weeks of therapy (25% pramlintide v 16% placebo) with comparable patterns in the 3 ethnic groups. Thus, pending further experience, the combined improvement in glycemic and weight control with pramlintide treatment appears to be generalizable to a broad population of mixed ethnicity.

Addition of pramlintide to insulin therapy lowers HbA1c in conjunction with weight loss in patients with type 2 diabetes approaching glycaemic targets

AIM

Two long-term, randomized, double-blind, placebo-controlled clinical trials in insulin-using patients with type 2 diabetes, spanning a wide range of baseline glycaemic control, have shown that the addition of pramlintide, an analogue of the beta-cell hormone amylin, to pre-existing insulin regimens results in reductions in HbA1c that are accompanied by weight loss.

METHODS

To assess whether this profile of pramlintide is observed in patients approaching, but not yet reaching, glycaemic targets, we conducted a pooled post hoc analysis of the two trials, including all patients with an entry HbA1c between 7.0 and 8.5%. Within this subset of patients, 80 were treated with placebo + insulin [baseline HbA1c 8.0 +/- 0.3%, weight 87.3 +/- 19.3 kg (mean +/- s.d.)] and 86 with pramlintide (120 micro g bid) + insulin [HbA1c 8.0 +/- 0.4%, weight 92.5 +/- 20.4 kg (mean +/- s.d.)]. Endpoints included changes from baseline to Week 26 in HbA1c, body weight, and the event rate of severe hypoglycaemia.

RESULTS

Adjunctive therapy with pramlintide resulted in significant reductions in both HbA1c and body weight from baseline to Week 26 (-0.43% and -2.0 kg differences from placebo, respectively, both p < 0.001). These changes were achieved without a concomitant increase in the overall rate of severe hypoglycaemic events (0.13 pramlintide vs. 0.19 placebo, events/patient year of exposure).

CONCLUSIONS

The data from this post hoc analysis indicate that the addition of pramlintide to insulin therapy may help patients with type 2 diabetes who are approaching, but not yet reaching, glycaemic targets to achieve further reductions in HbA1c without concomitant weight gain and increased risk of severe hypoglycaemia.

Non-responders to hepatitis B vaccination: a review

Hepatitis B virus (HBV) infection is a major public health issue throughout the world and vaccination of those at risk is the main method of containment. Of healthy vaccinees, 5-10% fail to mount an adequate antibody response. The antibody levels of an unknown further fraction of vaccinees fall considerably over time rendering them at a potential risk of infection. The scope of this article is to review the factors that might influence the immune response to HBV vaccination, to review the methods used to overcome the problem of poor response and to discuss what possible guidelines are available or needed in treating these vaccinees.

Prenatal diagnosis of congenital rubella infection in the second trimester of pregnancy

OBJECTIVES

This case report describes the clinical presentation, diagnosis and management of a case of acute rubella infection in the second trimester. The complex issues of prenatal diagnosis of a congenital rubella infection are discussed.

METHODS

A 30-year-old woman presented with a fine macular rash at 15 weeks' gestation. Laboratory testing included maternal rubella-specific IgG and IgM detection (booking blood and acute-phase sample) together with measurement of IgG avidity. Prenatal diagnosis at 19 weeks (amniocentesis) and 23 weeks (amniocentesis and fetal blood) was done using a reverse-transcriptase polymerase chain reaction to detect rubella-specific RNA. The fetal blood sample was also tested for rubella-specific IgM.

RESULTS

Maternal serological results confirmed an acute rubella infection at 15 weeks' gestation. Rubella-specific RNA and IgM were detected in the fetal blood taken at 23 weeks' gestation. However, no rubella RNA was detected in either of the amniotic fluid samples collected at 19 and 23 weeks.

CONCLUSION

In second-trimester rubella where risk of fetal damage is low, prenatal diagnosis can identify the rubella-infected fetus, allowing the parents to make a more informed decision about their options. The optimal sample for prenatal diagnosis is fetal blood as no rubella-specific RNA was detected in the amniotic fluid.

Helicobacter pylori eradication and gastric ulcer healing--comparison of three pantoprazole-based triple therapies

AIM

To study the efficacy of three pantoprazole-based triple therapy regimens for the eradication of Helicobacter pylori infection and gastric ulcer healing.

METHODS

In an open, multi-centre, randomized study, 519 H. pylori-positive patients with active gastric ulcer were randomized to receive pantoprazole (40 mg) (P) and two of three antibiotics: clarithromycin (500 mg) (C), metronidazole (500 mg) (M) or amoxicillin (1000 mg) (A). Triple therapy (PAC, PCM, PAM) was administered twice daily for 7 days, followed by pantoprazole until the ulcer had healed. Antrum and corpus biopsies were taken to determine the pattern of gastritis, to assess the H. pylori status and to determine the strain susceptibility to antibiotics, and from the ulcer margins and base to exclude malignancy. Scores based on the Sydney system were used to categorize the gastritis phenotypically.

RESULTS

The H. pylori eradication rates for the per protocol (intention-to-treat) analysis were 89% (67%) for PAC, 83% (68%) for PCM and 76% (60%) for PAM, with a significant difference between PAC and PAM. Healing rates after 4 weeks were 91% for PAM, 90% for PCM and 88% for PAC (per protocol analysis). The eradication rates were lower in patients in whom strains resistant to any antibiotic used in the triple therapies were detected. Successful eradication [odds ratio, 5.2 (3.3; 8.3)] and the ulcer size (< 15 mm) were significant predictors for healing after 4 weeks. The regimens showed a comparable safety profile and compliance.

CONCLUSIONS

Pantoprazole-based triple therapies are effective in the eradication of H. pylori infection in gastric ulcer patients, as reported in previous similar sized studies in duodenal ulcer patients. Successful eradication and an ulcer size of < 15 mm are the best predictors of gastric ulcer healing after 4 weeks.

The human amylin analog, pramlintide, reduces postprandial hyperglucagonemia in patients with type 2 diabetes mellitus

AIMS

Amylin is a second beta-cell hormone that is normally co-secreted with insulin in response to meals; it complements the effects of insulin in postprandial glucose control, in part by suppressing glucagon secretion. In patients with type 2 diabetes, mealtime administration of the human amylin analog pramlintide markedly improves postprandial glucose excursions. The aim of this study was to examine whether pramlintide reduces the postprandial hyperglucagonemia that is often seen in this patient population.

METHODS

Utilizing a single-blind, placebo-controlled crossover design, 24 patients with type 2 diabetes, 12 insulin-treated and 12 non-insulin-treated, underwent a standardized mixed meal test on 2 occasions during which they received, in randomized order, a five-hour intravenous infusion of placebo or pramlintide (100 microg/h).

RESULTS

During the placebo infusion, plasma glucose and plasma glucagon concentrations increased substantially after the meal. During the pramlintide infusion, postprandial plasma glucose and plasma glucagon responses were significantly (p < 0.05, all) reduced following ingestion of the same meal, both in the insulin-treated and non-insulin-treated subgroups.

CONCLUSION

Supplementation of mealtime amylin with pramlintide reduces postprandial hyperglucagonemia in patients with type 2 diabetes, a mechanism that likely contributes to pramlintide's postprandial glucose-lowering effect.

Food allergy in children

Food allergies are increasing in prevalence and as a disease burden throughout the world, however they seem to increasingly affect countries with a formerly low prevalence. Consideration and diagnosis of food allergies are important as it has ramifications that affect a child's diet, care at school and home and is recognised to be associated with anxiety of parents, family and care takers. Food allergies vary significantly between countries, however nut allergies appear to be widely associated with serious reactions and death. The value of specific food immunoglobulin E (IgE) and skin prick tests (SPT) has been extensively analysed in children in recent years and can provide very useful information in an appropriately selected population. Diagnosis may require formal challenges to confirm a genuine allergic reaction condition rather than an intolerance reaction due to other mechanisms. The medical care of a food allergic child requires concurrent dietary advice and management, risk avoidance and emergency management plans. Reintroduction of foods occurs when the risk profile is appropriate based mainly on the predictive information obtained by SPTs and specific IgE levels. Fortunately allergies to egg and milk resolve by 3-5 years in about 80% of children. There have been some recent advances in immunotherapeutic approaches to food allergy although this has not translated to success in human treatment to date.

Immunity induced after a feed of antigen during early life: oral tolerance v. sensitisation

There is good clinical and experimental evidence that oral tolerance exists in man and that the timing of antigen (food) administration is an important factor in the development of food allergic sensitisation and disease. Induction of tolerance is often seen as a T-helper 2-skewed response, which on one side may prevent harmful mucosal immune reactions, but on the other side may contribute to adverse responses in the susceptible individual. The primary mechanisms by which tolerance may be mediated include T-cell deletion, anergy, suppression 'ignorance' and apoptosis. Cell-mediated delayed hypersensitivity reactions (T-helper 1), which are implicated as a pathogenetic principle in the development of autoimmune and gastrointestinal inflammation are particularly well suppressed. Regulatory events during the induction of tolerance (or sensitisation) are not well characterised and remain at times controversial. The balance between tolerance (suppression) and sensitisation (priming) is dependent on several factors, such as: (a) genetic background; (b) nature of antigen and dose of antigen; (c) frequency of administration; (d) age (maturity v. immaturity) at first antigen exposure; (e) immunological status of the host (e.g. virus infection); dietary exposure of the mother; (g) antigen transmission via breast milk, and others. Overall, there is evidence in rodents that multiple low-dose feeds are more likely to induce regulatory cytokines (e.g. transforming growth factor-beta, interleukins 10 and 4) in part secreted by CD4+CD25+ T-regulatory cells. Despite the powerful suppressive effect of oral antigen exposure observed in experimental models, its application in clinical trials of autoimmune diseases has not yet yielded the expected beneficial results.

Immunomodulatory effects of breast milk oligosaccharides

Breast milk oligosaccharides are excreted in urine in amounts that suggest that they may exist in the circulation at levels compatible with a physiological function. Some oligosaccharides have structural similarity to cellular adhesion molecules and may influence adhesion of cells in breast fed infants. In this study, breast milk oligosaccharides were purified and incubated in assays of cell adhesion. They were found to inhibit neutrophil adhesion to stimulated vascular endothelial cells in a dose dependent fashion. In contrast they enhanced platelet-neutrophil complex formation. These results indicate that breast milk oligosaccharides may play a physiological role in modulating cellular adhesion in vivo.

Oligosaccharides in human milk: structural, functional, and metabolic aspects

Research on human milk oligosaccharides (HMOs) has received much attention in recent years. However, it started about a century ago with the observation that oligosaccharides might be growth factors for a so-called bifidus flora in breast-fed infants and extends to the recent finding of cell adhesion molecules in human milk. The latter are involved in inflammatory events recognizing carbohydrate sequences that also can be found in human milk. The similarities between epithelial cell surface carbohydrates and oligosaccharides in human milk strengthen the idea that specific interactions of those oligosaccharides with pathogenic microorganisms do occur preventing the attachment of microbes to epithelial cells. HMOs may act as soluble receptors for different pathogens, thus increasing the resistance of breast-fed infants. However, we need to know more about the metabolism of oligosaccharides in the gastrointestinal tract. How far are oligosaccharides degraded by intestinal enzymes and does oligosaccharide processing (e.g. degradation, synthesis, and elongation of core structures) occur in intestinal epithelial cells? Further research on HMOs is certainly needed to increase our knowledge of infant nutrition as it is affected by complex oligosaccharides.

New approaches for genotyping of Helicobacter pylori based on amplification of polymorphisms in intergenic DNA regions and at the insertion site of the cag pathogenicity island

The population of the gastric pathogen Helicobacter pylori shows a high degree of genetic diversity. It is well established that heterogeneity at the isolate level is caused by nucleotide transitions within genes, differences in the gene order, and by genetic instability of single genes as well as of a large virulence-associated genomic DNA region, the cag pathogenicity island (PAI). Analysis of intergenic regions with specific PCR-assays developed in this study, revealed that DNA polymorphisms in the noncoding DNA localized in front of the genes ribA and vacA and at the insertion site of the cag PAI contribute to the genetic diversity of H. pylori and are useful for differentiation of individual isolates. Thirteen individual genotypes were identified by PCR analysis of these polymorphic loci in 487, 241, and 182 clinical H. pylori isolates. Sequence analysis revealed that genetic variability in front of genes ribA and vacA, and in the intergenic region at the PAI insertion site is caused by insertion and deletions of so-far-unknown DNA sequences as well as by parts of the H. pylori IS elements IS605 and IS606, respectively. The new genotypes identified could be used to differentiate antrum and corpus isolates from the same patients. Their combination with vacA allele subtypes and with the cagA status allowed to differentiate 140 isolates in 51 subtypes. In 36 cases the corresponding genotype patterns were isolate specific. In summary, the results confirm that DNA polymorphisms in intergenic regions contribute to the genetic diversity of H. pylori. Although individual H. pylori genotypes were not associated with peptic ulcer disease, the PCR-based approaches for their detection developed here should be of use for further investigation of genetic diversity in H. pylori and for epidemiological purposes.

Secondary resistance among 554 isolates of Helicobacter pylori after failure of therapy

In a study to determine secondary resistance among Helicobacter pylori isolates, gastroenterologists from several German cities submitted over a 3-year period to centre A (Regensburg) or centre B (Freiburg) gastric biopsies from patients in whom one or more therapies to eradicate Helicobacter pylori had failed. Rates of resistance among the collections of 302 (centre A) and 252 (centre B) isolates were, respectively, as follows: to metronidazole, 75% and 66%; to clarithromycin, 58% and 49%; to amoxicillin, 0%; to ciprofloxacin, 9%; to doxycycline, 0%; and to rifampin, 0%. Resistance to clarithromycin was associated with metronidazole resistance in 89% and 85% of the isolates in centre A and centre B, respectively.

Rapid and specific detection of Helicobacter pylori macrolide resistance in gastric tissue by fluorescent in situ hybridisation

BACKGROUND

The development of macrolide resistance in Helicobacter pylori is considered an essential reason for failure of antibiotic eradication therapies. The predominant mechanism of resistance to macrolides, particularly clarithromycin, is based on three defined mutations within 23S rRNA, resulting in decreased binding of the antibiotic to the bacterial ribosome.

AIM

To develop an rRNA based whole cell hybridisation method to detect Helicobacter species in situ within gastric tissue, simultaneously with its clarithromycin resistance genotype.

METHODS

A set of fluorescent labelled oligonucleotide probes was developed, binding either to H pylori 16S rRNA or 23S rRNA sequences containing specific point mutations responsible for clarithromycin resistance. After hybridisation and stringent washing procedures, labelling of intact single bacteria was monitored by fluorescence microscopy. The new approach was compared with PCR based assays, histology, and microbiological culture.

RESULTS

In comparison with the phenotypic resistance measurement by E test, the genotypic clarithromycin resistance correlated perfectly (100%) for 35 H pylori isolates analysed. In a set of gastric biopsy specimens (27) H pylori infection was confirmed by histology (17/27) and correctly detected by whole cell hybridisation. Five clarithromycin resistant strains were identified in gastric tissue specimens directly. Furthermore, non-cultivable coccoid forms of H pylori were easily detectable by whole cell hybridisation.

CONCLUSIONS

Whole cell hybridisation of rRNA holds great promise for cultivation independent, reliable, and rapid (three hours) genotypic determination of clarithromycin resistance in H pylori. Compared with PCR techniques it is independent of nucleic acid preparations, not prone to inhibition, and allows semiquantitative visualisation of the bacteria within intact tissue samples.

Eradication of H. pylori with pantoprazole, clarithromycin, and metronidazole in duodenal ulcer patients: a head-to-head comparison between two regimens of different duration

BACKGROUND

The study was conducted to compare the efficacy and tolerability of two pantoprazole-based triple therapies of different length in the eradication of H. pylori.

METHODS

In this double-blind, multicenter parallel group comparison, H. pylori-positive patients were randomly assigned to either the PCM-7 group (7 days of pantoprazole 40 mg bid, clarithromycin 500 mg bid, metronidazole 500 mg bid) or the PCM-14 m group (modified 14 day therapy of the same regimen with metronidazole only given for 10 days due to labeling reasons). H. pylori status was determined by urease test, histology, culture, and 13C-urea breath test. Treatment outcome was assessed 6 weeks after intake of the last study medication.

RESULTS

The following eradication rates were achieved: for PCM-7 in the MITT population 83% (89/107), in the PP population 84% (81/97); for PCM-14 m in MITT 87% (92/106), in PP 88% (91/104). Ulcer healing rates were: for PCM-7 in MITT population 99% (106/107), in the PP population 99% (96/97); for PCM-14 m in MITT 99% (105/106), in PP 99% (103/104). Gastrointestinal symptoms and gastritis scores decreased in both treatment groups. Equivalence of treatment regimens could be proven for all populations. In total, 64 patients reported adverse events. Five serious adverse events occurred, all unrelated to the study medication.

CONCLUSION

The two pantoprazole-based triple therapies tested in this study are equally effective in H. pylori eradication, ulcer healing and relief from ulcer pain. It is concluded that 7 days of triple therapy are generally sufficient.

Identification and molecular analysis of superoxide dismutase isoforms in Helicobacter pylori

Three electromorphs of iron superoxide dismutase (FeSOD) were identified among 29 Helicobacter pylori isolates by native gel electrophoresis and activity staining. The electromorphs designated isoforms A, B, and C are characterized by slow, intermediate and fast electrophoretic migration, respectively, which was not observed under denaturing conditions. The isoforms were not associated with virulence determinants and with the outcome of disease. Sequence analysis of the sodB gene in strains producing different FeSOD isoforms and comparison of deduced protein sequences revealed that differences in the electric migration behavior are associated with exchange of charged amino acids, suggesting that faster migration is caused by a more negative total charge of the proteins. Electrophoretic migration of native FeSOD was not influenced by changes in the iron cofactor concentration, oxidative stress, and different media, indicating that FeSOD isoforms represent stable strain-specific markers.

Modulation of antigen trafficking to MHC class II-positive late endosomes of enterocytes

BACKGROUND & AIMS

Oral tolerance is recognized as a central immunoregulatory phenomenon. The mechanisms of its induction remain unclear, and the role of the intestinal epithelial cells that are able to present antigens to T lymphocytes is poorly understood. In this report, we analyze under in vivo conditions the intracellular targeting of mucosally administered ovalbumin (OVA) to major histocompatibility complex (MHC) class II antigen containing compartments of enterocytes and compare these pathways between BALB/c and SCID mice, the latter being unable to generate a transferable tolerogenic moiety after a feed of OVA.

METHODS

OVA, lysosome-associated membrane proteins (LAMP-1), and MHC class II antigens were localized in jejunal biopsy specimens of BALB/c and SCID mice at 0, 5, 10, 20, 40, 60, and 120 minutes after a single feed with OVA by fluorescence and electron microscopy.

RESULTS

Ten minutes after oral administration, OVA was transported to the proximity of MHC class II antigens within LAMP-1-positive vacuoles and to the basolateral membrane of enterocytes from BALB/c strain mice. However, in SCID mice, OVA reached the paracellular spaces during the same time period through LAMP-1-negative vacuoles of enterocytes, which lacked MHC class II antigens.

CONCLUSIONS

Orally administered OVA is rapidly targeted to late endosomes containing LAMP-1 and MHC class II antigens in enterocytes of BALB/c mice but not in SCID mice bred on a BALB/c background. We suggest that this targeting process within the enterocytes is one of the requirements for the induction of oral tolerance.

Impact of ELISA and immunoblot as diagnostic tools one year after eradication of Helicobacter pylori in a multicentre treatment study

The performance of serological tests for Helicobacter pylori infections is hampered by the persistence of antibodies after eradication therapy or spontaneous healing. Detection of different antigens or immunoglobulin classes might have an impact on the validity of serodiagnosis. The aim of this study was to assess the decrease in IgA and IgG antibody levels after eradication of H. pylori. Serum samples of 242 patients with active duodenal ulcer were tested with the ELISA and the immunoblot (IB) techniques for H. pylori-specific IgA and IgG antibodies before therapy and 1 year after successful eradication. From a total of 81 patients paired sera were available. At the end of the follow-up period ELISA antibody titres from the IgA class had decreased from a mean value of 6.69 to 4.26 units (P = 0.0001), and IgG class antibody titres from a mean value of 21.9 to 12.1 units (P = 0.0001). Regarding seroreversion, from 34 initially IgA positive sera 16 (47%), and from 74 IgG positive sera 18 (24%), had definitively reverted to 'negative'. One year after eradication, when tested with the immunoblot, the antibody responses against specific antigens of 37% IgA-positive sera (23/62) and 8% IgG-positive sera (6/78) reverted to 'negative', compared to a seroreversion rate of 27% of the anti-CagA IgA-positive sera (18/67) and of 9% of the anti-CagA IgG-positive sera (7/79). In conclusion, despite an overall significant decrease of H. pylori antibodies, both tests cannot be recommended for monitoring treatment success.

Growth, development and differentiation: a functional food science approach

Few other aspects of food supply and metabolism are of greater biological importance than the feeding of mothers during pregnancy and lactation, and of their infants and young children. Nutritional factors during early development not only have short-term effects on growth, body composition and body functions but also exert long-term effects on health, disease and mortality risks in adulthood, as well as development of neural functions and behaviour, a phenomenon called 'metabolic programming'. The interaction of nutrients and gene expression may form the basis of many of these programming effects and needs to be investigated in more detail. The relation between availability of food ingredients and cell and tissue differentiation and its possible uses for promoting health and development requires further exploration. The course of pregnancy, childbirth and lactation as well as human milk composition and the short- and long-term outcome of the child are influenced by the intake of foods and particularly micronutrients, e.g. polyunsaturated fatty acids, Fe, Zn and I. Folic acid supplementation from before conception through the first weeks of pregnancy can markedly reduce the occurrence of severe embryonic malformations; other potential benefits of modulating nutrient supply on maternal and child health should be further evaluated. The evaluation of dietary effects on child growth requires epidemiological and field studies as well as evaluation of specific cell and tissue growth. Novel substrates, growth factors and conditionally essential nutrients (e.g. growth factors, amino acids, polyunsaturated fatty acids) may be potentially useful as ingredients in functional foods and need to be assessed carefully. Intestinal growth, maturation, and adaptation as well as long-term function may be influenced by food ingredients such as oligosaccharides, gangliosides, high-molecular-mass glycoproteins, bile salt-activated lipase, pre- and probiotics. There are indications for some beneficial effects of functional foods on the developing immune response, for example induced by antioxidant vitamins, trace elements, fatty acids, arginine, nucleotides, and altered antigen contents in infant foods. Peak bone mass at the end of adolescence can be increased by dietary means, which is expected to be of long-term importance for the prevention of osteoporosis at older ages. Future studies should be directed to the combined effects of Ca and other constituents of growing bone, such as P, Mg and Zn, as well as vitamins D and K, and the trace elements F and B. Pregnancy and the first postnatal months are critical time periods for the growth and development of the human nervous system, processes for which adequate substrate supplies are essential. Early diet seems to have long-term effects on sensory and cognitive abilities as well as behaviour. The potential beneficial effects of a balanced supply of nutrients such as I, Fe, Zn and polyunsaturated fatty acids should be further evaluated. Possible long-term effects of early exposure to tastes and flavours on later food choice preferences may have a major impact on public health and need to be further elucidated. The use of biotechnology and recombinant techniques may offer the opportunity to include various bioactive substances in special dietary products, such as human milk proteins, peptides, growth factors, which may have beneficial physiological effects, particularly in infancy and early childhood.

Identification and analysis of a new vacA genotype variant of Helicobacter pylori in different patient groups in Germany

The vacuolating cytotoxin of Helicobacter pylori (VacA) is known to cause cell damage to mammalian cells and is suspected to give rise to gastric epithelial lesions that might lead to peptic ulcer disease. As shown recently, the gene encoding VacA exhibits genetic variation, with three different families of signal sequences (s1a, s1b, and s2) and two families of midregion sequences (m1 and m2). In order to investigate the relationship between the presence of specific vacA genotypes and peptic ulceration, the vacA genotypes of 158 clinical isolates of H. pylori were determined. The study group consisted of 106 patients with duodenal ulceration; 52 patients with nonulcer dyspepsia (NUD) were used as controls. H. pylori of genotype s1 was isolated from 96% of the patients with ulcerations, whereas genotype s2 was only present in 4%, indicating a strong correlation between the vacA genotype and peptic ulceration (P < 0.001). In contrast, 31% of the patients from the NUD control group were infected with strains of vacA genotype s2. Particular midregion genotypes (m1 and m2) were not associated with clinical manifestations. The midregions from 18% of the isolates could not be classified by the proposed scheme. DNA sequencing revealed high homology between the untypeable midregions and that of genotype m1, with multiple base pair exchanges, some affecting the primer annealing site. Compared to those of m1 and m2 alleles, the divergent midregions from untypeable strains showed clustering, indicating the presence of a further subfamily of sequences in the midregion of vacA in German isolates, for which we propose the term "m1a." A new specific primer that we designed for typing m1a isolates might be useful in other studies.

Immune responses to dietary antigens: oral tolerance

The concept of immunologically mediated tolerance to food antigens through exposure to mucosal antigen has been the subject of continuous scientific debate. After a decline in interest in the mid-1980s, oral tolerance has again attracted the attention of immunologists. Here, Stephan Strobel and Allan Mowat discuss how this central immunological principle has potential new therapeutic applications for the treatment of autoimmune, inflammatory and possibly food-allergic diseases.

Bilateral deafness due to congenital CMV and not rubella reinfection

We report on an infant with bilateral deafness discovered at the age of 5 months caused by a retrospectively diagnosed primary maternal CMV infection after definitive exclusion of maternal rubella reinfection as a cause of fetal infection.

Cardiopulmonary bypass tubes and prime solutions stimulate neutrophil adhesion molecules

OBJECTIVE

To evaluate effects of the material of the cardiopulmonary bypass (CPB) tubes (polyvinyl chloride, PVC) and prime solutions on expression of neutrophil adhesion molecule CD11b and L-selectin.

METHODS

We carried out a series of experiments using donor blood from 30 healthy adult human volunteers. In all experiments, neutrophil cell surface expressions of CD11b and L-selectin were assayed immediately and serially up to 2 hours, using immune-fluorescence techniques and flow cytometry. Study 1: Effects of PVC were compared with glass and polystyrene (n = 5). Study 2: Blood was mixed with Plasma-lyte (Pl) (prime solution), Hartman solutions, albumin or not altered (control), n = 5. Study 3: The effects of changing pH of the Pl (control, neutralised and acidic solution, n = 5) were examined. Study 4: Haemodilution (undiluted, 1:1, 1:2, and 1:3, vol/vol, prime to blood, n = 5) was carried out using Pl and the subsequent changes in expressions of the adhesion molecules were analysed. Study 5: The combined effect of PVC and Pl was assessed (n = 5). Study 6: We evaluated the effect of increasing plasma water by adding sterile water to whole blood and compared it with control (n = 5).

RESULTS

Study 1: PVC, similar to glass, caused more up-regulation of CD11b and down-regulation of L-selectin than polystyrene (238 and 162% vs. 68 increase of CD11b, P < 0.001; 89 and 95% vs. 16% decrease of L-selectin, P < 0.001). Study 2: Pl and Hartman solutions caused more up-regulation of CD11b and down-regulation of L-selectin compared to albumin and control (166 and 188% vs. 26 and 44% increase of CD11b, P < 0.01; 19 and 26% vs. 10 and 6% decrease of L-selectin, P < 0.01, respectively). Study 3: Haemodilution had no effect on these molecules. Study 4: The mean of the difference between the acidic and neutral solution was 208% increase of CD11b and 30% decrease of L-selectin, P < 0.05. Study 5: The combined effect of mixing blood with Pl and exposure to PVC caused marked up-regulation of CD11b (336% increase, P < 0.01) and down-regulation of L-selectin (78% decrease, P < 0.05). Study 6: Water for injection caused marked up-regulation of CD1 1b and down-regulation of L-selectin.

CONCLUSIONS

Mixing blood with acidic prime solution and/or exposing it to PVC tubes causes up-regulation of neutrophil adhesion molecule CD11b and down-regulation of L-selectin. Neutralisation of the prime solution reduces the extent of neutrophil activation, whereas haemodilution has no effect. Increasing plasma water is stimulating to the neutrophil. Modulation of prime solutions and the material of CPB tubes may reduce neutrophil activation which may reduce patient morbidity.