Egg proteins as allergens and the effects of the food matrix and processing

Hen eggs are an important and inexpensive source of high-quality proteins in the human diet. Egg, either as a whole or its constituents (egg yolk and white), is a key ingredient in many food products by virtue of its nutritional value and unique functional properties, such as emulsifying, foaming, and gelling. Nevertheless, egg is also known because of its allergenic potential and, in fact, it is the second most frequent source of allergic reactions, particularly in children. This review deals with the structural or functional properties of egg proteins that make them strong allergens. Their ability to sensitize and/or elicit allergic reactions is linked to their resistance to gastroduodenal digestion, which ultimately allows them to interact with the intestinal mucosa where absorption occurs. The factors that affect protein digestibility, whether increasing it, decreasing it, or inducing a different proteolysis pattern, and their influence on their capacity to induce or trigger an allergic reaction are discussed. Special attention is paid to the effect of the food matrix and the processing practices on the capacity of egg proteins to modulate the immune response.

Clinical comparison of 10q26 overlapping deletions: delineating the critical region for urogenital anomalies

The 10q26 deletion syndrome is a clinically heterogeneous disorder. The most common phenotypic characteristics include pre- and/or postnatal growth retardation, microcephaly, developmental delay/intellectual disability and a facial appearance consisting of a broad nasal bridge with a prominent nose, low-set malformed ears, strabismus, and a thin vermilion of the upper lip. In addition, limb and cardiac anomalies as well as urogenital anomalies are occasionally observed. In this report, we describe three unrelated females with 10q26 terminal deletions who shared clinical features of the syndrome, including urogenital defects. Cytogenetic studies showed an apparently de novo isolated deletion of the long arm of chromosome 10, with breakpoints in 10q26.1, and subsequent oligo array-CGH analysis confirmed the terminal location and defined the size of the overlapping deletions as ∼ 13.46, ∼ 9.31 and ∼ 9.17 Mb. We compared the phenotypic characteristics of the present patients with others reported to have isolated deletions and we suggest that small 10q26.2 terminal deletions may be associated with growth retardation, developmental delay/intellectual disability, craniofacial features and external genital anomalies whereas longer terminal deletions affecting the 10q26.12 and/or 10q26.13 regions may be responsible for renal/urinary tract anomalies. We propose that the haploinsufficiency of one or several genes located in the 10q26.12-q26.13 region may contribute to the renal or urinary tract pathogenesis and we highlight the importance of FGFR2 and probably of CTBP2 as candidate genes.

Array CGH detection of a novel cryptic deletion at 3q13 in a complex chromosome rearrangement

Complex chromosome rearrangements (CCRs) are extremely rare in humans. About 20% of the apparently balanced CCRs have an abnormal phenotype and the degree of severity correlates with a higher number of breakpoints. Several studies using FISH and microarray technologies have shown that deletions in the breakpoints are common although duplications, insertions and inversions have also been detected. We report a patient with two simultaneous reciprocal translocations, t(3;4) and t(2;14;18), involving five chromosomes and six breakpoints. He showed dysmorphic features, preaxial polydactyly in the left hand, brachydactyly, postnatal growth retardation and developmental delay. The rearrangement was characterized by FISH analysis which detected an interstitial segment from chromosome 14 inserted in the derivative chromosome 2, and by whole genome array which revealed an interstitial deletion of approximately 4.5 Mb at the breakpoint site on chromosome 3. To our knowledge this microdeletion has not been previously reported and includes ~12 genes. The haploinsufficiency of one or several of these genes is likely to have contributed to the clinical phenotype of the patient.

Pre- and postnatal findings in a patient with a novel rec(8)dup(8q)inv(8)(p23.2q22.3) associated with San Luis Valley syndrome

San Luis Valley syndrome, which is due to a recombinant chromosome 8 (SLV Rec8) found in Hispanic individuals from Southwestern United States, is a well-established syndrome associated with intellectual disabilities and, frequently, severe cardiac anomalies. We report for the first time on a Moroccan girl with a recombinant chromosome 8 prenatally diagnosed as SLV Rec8 by conventional cytogenetic studies. At birth, an oligo array-CGH (105 K) defined the breakpoints and the size of the imbalanced segments, with a deletion of ≈ 2.27 Mb (8p23.2-pter) and a duplication of ≈ 41.93 Mb (8q22.3-qter); thus this recombinant chromosome 8 differed from that previously reported in SLV Rec8 syndrome. The phenotypic characteristics associated with this SLV Rec8 genotype overlap those commonly found in patients with 8q duplication reported in the literature. We review SLV Rec8 and other chromosome 8 aberrations and suggest that the overexpression of cardiogenic genes located at 8q may be the cause of the cardiac defects in this patient.

Performance evaluation of biochemical and ultrasound markers for the screening of chromosomal numerical abnormalities in the first trimester of pregnancy

BACKGROUND

To estimate the effectiveness of the first-trimester combined screening test in our population, departing from the results of diagnostic sensitivity and false positive rate (FPR), and checking some important parameters in prenatal screening.

METHODS

The test was evaluated on 14250 pregnant women. The following variables were studied: the number of invasive techniques and the reasons for using such techniques, newborns with chromosomal abnormalities, total number of births, variation of biochemical markers throughout the gestational weeks, and MoM (multiple of the median) for biochemical and ultrasound markers.

RESULTS

An important coverage and a decreased number of invasive techniques were obtained. For our population of pregnant women, the best gestational week to determine free beta-hCG and PAPP-A would be week 11 in which the best discrimination was found between affected and non affected fetuses for the three trisomies researched. We propose the cut-off 1/350, because it is the best one to increase sensitivity without exceeding the 5% FPR.

CONCLUSIONS

Combined screening should be offered to pregnant woman, preferentially at week 11. Although different cut-offs for this prenatal test have been recommended by scientific societies, biochemical laboratories should set their own cut-off for getting the best sensitivity and FPR results. There should be a good level of collaboration between the laboratory and each participating ultrasound unit in order to ensure an optimal use of the first-trimester combined screening test.

Management of a dichorionic twin pregnancy with a normal fetus and an androgenetic diploid complete hydatidiform mole

We describe a rare case of complete hydatidiform mole with twin live fetus (CHMTF) confirmed by histopathology, flow cytometry, and polymerase chain reaction techniques. No malformations were observed, fetal karyotype was normal and β-human chorionic gonadotropin levels were increased (>100,000 IU/ml). Once the patient had been informed of the risks, it was decided to continue the pregnancy, but termination of pregnancy was necessary at week 13 + 5 due to maternal complications consisting of hyperthyroidism, hypertension and vaginal bleeding, followed by persistent trophoblastic disease (PTD). Patients diagnosed with CHMTF should be informed of all known risks, including the considerable risk of PTD, which is similar to - or according to some reports - even higher than that associated with a singleton complete mole and is not increased by continuing pregnancy. Due to the low number of series published, evidence-based clinical management guidelines are lacking.

In vivo methods for testing allergenicity show that high hydrostatic pressure hydrolysates of β-lactoglobulin are immunologically inert

The major milk allergen β-lactoglobulin (β-LG) exhibits an enhanced susceptibility to proteolysis under high hydrostatic pressure and this may be an efficient method to produce hypoallergenic hydrolysates. The aim of this work was to evaluate the in vivo allergenicity of 3 β-LG hydrolysates produced under atmospheric pressure or high-pressure conditions. Hydrolysates were chosen based on previous experiments that showed that they provide a complete removal of intact β-LG but differed in vitro IgE-binding properties that could be traced to the peptide pattern. The ability to trigger systemic anaphylaxis was assessed using C3H/HeJ mice orally sensitized to β-LG. Outcome measures included symptom score, body temperature, serum mouse mast cell protease 1 (mMCP-1), and quantification of circulating basophils. Mast cell degranulation in vivo was assessed by passive cutaneous anaphylaxis. The 3 tested hydrolysates showed an abrogated allergenicity as revealed by the absence of anaphylactic symptoms and a decrease in body temperature. We demonstrated that the peptides present in the hydrolysates had lost their ability to cross-link 2 human IgE antibodies to induce mast cell degranulation, thus indicating that most of the peptides formed retain just one relevant IgE-binding epitope. The orally sensitized mouse model is a useful tool to address the in vivo allergenicity of novel milk formulas and demonstrates the safety of hydrolysates produced under high-pressure conditions.

Molecular characterization of a new patient with a non-recurrent inv dup del 2q and review of the mechanisms for this rearrangement

We report on newborn baby with microcephaly, facial anomalies, congenital heart defects, hypotonia, wrist contractures, long fingers, adducted thumbs, and club feet. Cytogenetic studies revealed an inverted duplication with terminal deletion (inv dup del) of 2q in the patient and a paternal 2qter deletion polymorphism. Microsatellite markers demonstrated that the inv dup del was maternal in origin and intrachromosomal. Intra or interchromosomal rearrangements may cause this aberration either by a U-type exchange (end-to-end fusion), an unequal crossover between inverted repeats (non-allelic homologous recombination: NAHR), or through breakage-fusion-bridge (BFB) cycles leading to a sister chromatid fusion by non-homologous end joining (NHEJ). A high-resolution oligo array-CGH (244 K) defined the breakpoints and did not detect a single copy region with a size exceeding 12.93 Kb in the fusion site. The size of the duplicated segment was 38.75 Mb, extending from 2q33.1 to 2q37.3 and the size of the terminal deletion was 2.85 Mb in 2q37.3. Our results indicate that the inv dup del (2q) is likely a non-recurrent chromosomal rearrangement generated by a NHEJ mechanism. The major clinical characteristics associated with this 2q rearrangement overlap with those commonly found in patients with 2q duplication reported in the literature.

Partial mole with a diploid fetus: case study and literature review

OBJECTIVE

To describe an extremely rare case of a partial hydatidiform mole with a normal fetus. The etiology and clinical management of this entity are discussed.

METHOD

Case report.

RESULTS

We describe a rare case of partial mole and a living fetus of diploid karyotype and biparental origin confirmed by flow cytometry and PCR techniques. No malformations were observed, beta-hCG levels were high (>100,000 mIU/ml) and persistent trophoblastic disease did eventually occur.

CONCLUSION

A suspected partial mole on ultrasound with increased beta-hCG and a sonographically normal living fetus of a diploid karyotype poses a dilemma for clinical management. Termination of pregnancy is not indicated if the fetus is normal; in fact, continuation to birth is possible in nearly 60% of cases with no increase in maternal risks when the patient is closely monitored after birth until beta-hCG is negative. In the case presented, however, a spontaneous abortion occurred at 21 weeks' gestation, possibly as a result of the amniocentesis.

Synergistic effect between different milk-derived peptides and proteins

Antimicrobial peptides derived from food proteins constitute a new field in the combined use of antimicrobial agents in food. The best examples of milk-derived peptides are those constituted by bovine lactoferricin [lactoferrin f(17-41)] (LFcin-B) and bovine alpha(s2)-casein f(183-207). The aim of this work was to study if the antimicrobial activity of a natural compound employed in food preservation, nisin, could be enhanced by combination with the aforementioned milk-derived peptides. Furthermore, the possibility of a synergistic effect between these peptides and bovine lactoferrin (LF) against Escherichia coli and Staphylococcus epidermidis was also studied. Finally, the most active combinations were assayed against the foodborne pathogens Listeria monocytogenes and Salmonella choleraesuis. Results showed a synergistic effect when LFcin-B was combined with bovine LF against E. coli. In the same way, the combination of LFcin-B with bovine LF was synergistic against Staph. epidermidis. Bovine LF and nisin increased their antimicrobial activity when they were assayed together with bovine alpha(s2)-casein f(183-207). It is important to note the synergistic effect among LFcin-B and bovine LF, because both compounds might be simultaneously in the suckling gastrointestinal tract and could, therefore, have a protective effect on it. The other synergistic effect high-lighted is that between alpha(s2)-casein f(183-207) and nisin against L. monocytogenes because of the ability of L. monocytogenes to develop resistance to nisin.

Intrachromosomal partial triplication of chromosome 13 secondary to a paternal duplication with mild phenotypic effect

Intrachromosomal triplications are rare and can be mistaken for duplications. The majority of triplications reported are de novo, mostly involving chromosome 15q, and have a middle inverted repeat. We report on the clinical, cytogenetic, and molecular analyses of a patient with a novel triplication 13q21.1-q21.33 secondary to a familial duplication 13q21.1-q21.33 with mild phenotypic effect in three generations. The propositus was an 8-year-old boy referred because of language delay and mild mental retardation. His weight, height and OFC were above the 97th centile. He had delayed tooth eruption and subtle dysmorphic features. Chromosome analysis (550 band stage) showed extra material in 13q21. Family history was unremarkable except for adult-onset sensorineural hearing loss in the father and paternal grandfather. Their karyotypes and those of both brothers of the propositus also showed an abnormal chromosome 13 but with less extra genetic material. FISH analysis with several BAC clones showed a triplication in the propositus between 204N9 and 184B18 (which mapped to 13q21.1 and 13q21.33, respectively) and a direct duplication for the same fragment (around 12 Mb) in the rest of the family members with the abnormal chromosome 13. The FISH signals did not show a middle inverted repeat. We describe the first intrachromosomal triplication 13q21.1-q21.33 derived from a paternal duplication. Meiotic instability in the transmission of a duplication has not been previously observed. Phenotypic variability may be explained by chromosomal non-penetrance or dosage critical loci located in the triplicate/duplicate segment.