Latest Developments in the Management of Nut Allergies.

PURPOSE OF REVIEW: In this review, we sought to describe the most recent advances in the dietary and medical management of peanut and tree nut allergy, including selective introduction and immunotherapy. RECENT FINDINGS: Dietary updates include changes to labeling laws, improved information sources, and new apps for buying foods in shops and overseas to better protect individuals with nut allergies. There are still issues in the management of nut allergies in schools, such as parents having to resort to packed lunches instead of school meals and patients experiencing bullying. Air travel also poses concern, but additional resources are now available to travelers, and recent evidence suggest limited airborne exposure to nuts. The medical management of anaphylaxis is use of epinephrine; however, this remains underutilized. Needle length and administration devices have been recently debated considering the risk of bone penetration vs subcutaneous administration, and autoinjectors seem to deliver higher peak concentrations than syringes. Selective nut introduction has gained momentum in the last 5 years, demonstrating improved quality of life but with the need for motivated parents for continued consumption and available resources for challenges. Immunotherapy to nuts is also a rapidly developing field, with the balance of efficacy and safety being important considerations in the differing modes of administration. SUMMARY: The management of nut allergies is a rapidly developing field, and dietary and medical management have progressed significantly in the last 5 years. Future research directions include improving safety and efficacy of food immunotherapy and examining patients' goals for therapy and treatment outcomes.

Economic modelling of diagnostic and treatment pathways in National Institute for Health and Care Excellence clinical guidelines: the Modelling Algorithm Pathways in Guidelines (MAPGuide) project.

BACKGROUND: National Institute for Health and Care Excellence (NICE) clinical guidelines (CGs) make recommendations across large, complex care pathways for broad groups of patients. They rely on cost-effectiveness evidence from the literature and from new analyses for selected high-priority topics. An alternative approach would be to build a model of the full care pathway and to use this as a platform to evaluate the cost-effectiveness of multiple topics across the guideline recommendations. OBJECTIVES: In this project we aimed to test the feasibility of building full guideline models for NICE guidelines and to assess if, and how, such models can be used as a basis for cost-effectiveness analysis (CEA). DATA SOURCES: A 'best evidence' approach was used to inform the model parameters. Data were drawn from the guideline documentation, advice from clinical experts and rapid literature reviews on selected topics. Where possible we relied on good-quality, recent UK systematic reviews and meta-analyses. REVIEW METHODS: Two published NICE guidelines were used as case studies: prostate cancer and atrial fibrillation (AF). Discrete event simulation (DES) was used to model the recommended care pathways and to estimate consequent costs and outcomes. For each guideline, researchers not involved in model development collated a shortlist of topics suggested for updating. The modelling teams then attempted to evaluate options related to these topics. Cost-effectiveness results were compared with opinions about the importance of the topics elicited in a survey of stakeholders. RESULTS: The modelling teams developed simulations of the guideline pathways and disease processes. Development took longer and required more analytical time than anticipated. Estimates of cost-effectiveness were produced for six of the nine prostate cancer topics considered, and for five of eight AF topics. The other topics were not evaluated owing to lack of data or time constraints. The modelled results suggested 'economic priorities' for an update that differed from priorities expressed in the stakeholder survey. LIMITATIONS: We did not conduct systematic reviews to inform the model parameters, and so the results might not reflect all current evidence. Data limitations and time constraints restricted the number of analyses that we could conduct. We were also unable to obtain feedback from guideline stakeholders about the usefulness of the models within project time scales. CONCLUSIONS: Discrete event simulation can be used to model full guideline pathways for CEA, although this requires a substantial investment of clinical and analytic time and expertise. For some topics lack of data may limit the potential for modelling. There are also uncertainties over the accessibility and adaptability of full guideline models. However, full guideline modelling offers the potential to strengthen and extend the analytical basis of NICE's CGs. Further work is needed to extend the analysis of our case study models to estimate population-level budget and health impacts. The practical usefulness of our models to guideline developers and users should also be investigated, as should the feasibility and usefulness of whole guideline modelling alongside development of a new CG. FUNDING: This project was funded by the Medical Research Council and the National Institute for Health Research through the Methodology Research Programme [grant number G0901504] and will be published in full in Health Technology Assessment; Vol. 17, No. 58. See the NIHR Journals Library website for further project information.

An improved method for the diagnostic approach of alpha+-thalassaemia.

An improved method for the diagnostic approach of alpha(+)-thalassaemia is described. The method is based on five common parameters: absence of iron deficiency, mild morphological abnormalities of erythrocytes, normal or slightly reduced erythrocytic indices MCV and MCH, normal chromatographic findings, and presence of haemoglobin H inclusions in erythrocytes with methyl-violet stain after, but not before, incubation with oxidant agent. We studied by DNA analysis, 58 subjects fulfilling the above mentioned diagnostic criteria and we found that 50 of them (86.2%) had a alpha-globin gene defect. In the remaining eight subjects (13.8%) no alpha-gene defect could be documented with the techniques used in the DNA analysis, which detect the six well-known alpha(+)-thalassaemic defects in the Greek population. We conclude that the improved method, we described has a high sensitivity and accuracy in the screening of alpha(+)-thalassaemia.

Axonal sensorimotor neuropathy in patients with beta-thalassaemia.

OBJECTIVE: The purpose of this study was to investigate the prevalence of peripheral neuropathy in patients with beta-thalassaemia. METHODS: Thirty six patients with a mean age of 29.2+/-8.2 years and 17 healthy controls with a mean age of 27.6+/-9.1 were included in this study. Measurements included the neuropathy symptoms score (NSS), the neuropathy disability score (NDS) as well as nerve conduction studies of two motor (ulnar and peroneal) and two sensory (ulnar and sural) nerves of the right limbs. RESULTS: A mainly sensory axonal polyneuropathy was present in 19 out of 36 patients (52.7%). Eight out of these 19 patients also had abnormal NDS values. The neuropathy correlated significantly with the age of the patients and the hematocrit. However, it did not correlate with the presence of antibodies against HCV, the ferritin levels, or with a history of transfusions, desferrioxamine treatment, or splenectomy. CONCLUSIONS: This study showed a high prevalence of a predominantly sensory neuropathy in patients with beta-thalassaemia. The electrophysiological data suggest that the underlying pathology is an axonopathy. Chronic hypoxia of the nerves resulting from severe anaemia may contribute to the pathogenesis of this neuropathy.

Agamma-haplotypes: a new group of genetic markers for thalassemic mutations inside the 5' regulatory region of the human Agamma-globin gene.

This study illustrates the relationship between a group of nucleotide variations within the 5' regulatory region of the Agamma-globin gene [Agamma-588 A-->G, Agamma-499 T-->A and the 4-bp deletion (Agamma-225 to -222 AGCA)] and the spectrum of delta- and beta-thalassemia mutations in the Hellenic population. These sequence variations, screened by means of denaturing gradient gel electrophoresis, form four separate frameworks (Agamma-haplotypes), each one of which was found to be linked in cis with certain delta- and beta-thalassemia mutations found in the Hellenic population. In addition, two novel base substitutions inside the 5' regulatory region of the Agamma-globin gene (Agamma-521 C-->A and Ay-500 C-->T) were identified during this study, which together with Agamma-haplotypes seem to be silent polymorphisms during adult life, as indicated by transient expression assays. Our data show that Agamma-haplotypes represent genetic markers for the spectrum of thalassemic mutations, found in the Hellenic population and can constitute an important genetic repository upon which mutations leading to thalassemia and hemoglobinopathies occurred.

The Cretan type of non-deletional hereditary persistence of fetal hemoglobin [A gamma-158C-->T] results from two independent gene conversion events.

We report a new type of non-deletional hereditary persistence of fetal hemoglobin that is due to a C-->T transition at position -158, relative to the Cap site of the human Agamma-globin gene. This mutation was identified in three unrelated adult cases presenting slightly elevated levels of fetal hemoglobin (Hb F), i.e. 2.9-5.1%, and normal hematological indices. Our sequencing results, from both polymerase chain reaction-amplified and subcloned DNA fragments, indicate that the A gamma -158C-->T mutation occurred by two independent gene conversion events in the three cases studied. In addition, hematological and molecular data, including restriction fragment length polymorphism haplotyping in the beta-globin gene cluster, extended haplotype analysis inside the gamma-globin gene region and routine analysis of three tandem repeat loci (D1S80, 3'HVR/apoB and F8vWf), led us to conclude that the A gamma -158C-->T mutation in one of the three cases occurred recently in the parental germ line (P=99.47%), representing the first example of a de novo gene conversion event identified in humans.

A new family of Greek origin maps to the CRD locus for autosomal dominant cone-rod dystrophy on 19q.

Retinal photoreceptor dystrophies (RD) are a highly heterogeneous group of genetic disorders of the retina, representing the most frequently inherited form of visual handicap, affecting approximately 1.5 million people world wide. To date, more than 40 genetic loci have been implicated in RD. One of them, the CORD2 locus, for an autosomal dominant form of cone-rod dystrophy (CRD), maps to chromosome 19q and has previously been reported in a single large family of British origin. We now report a new family with severe early onset CRD, phenotypically very similar to the British family, which also maps to 19q, but is of Greek origin. Haplotype data of the Greek family showed no recombination between and including markers D19S219 and D19S246 and linkage analysis gave a lod score of 2.7 (at theta=0) with marker D19S412, confirming the data obtained in the British family.

Cone-rod dystrophy due to mutations in a novel photoreceptor-specific homeobox gene (CRX) essential for maintenance of the photoreceptor.

Genes associated with inherited retinal degeneration have been found to encode proteins required for phototransduction, metabolism, or structural support of photoreceptors. Here we show that mutations in a novel photoreceptor-specific homeodomain transcription factor gene (CRX) cause an autosomal dominant form of cone-rod dystrophy (adCRD) at the CORD2 locus on chromosome 19q13. In affected members of a CORD2-linked family, the highly conserved glutamic acid at the first position of the recognition helix is replaced by alanine (E80A). In another CRD family, a 1 bp deletion (E168 [delta1 bp]) within a novel sequence, the WSP motif, predicts truncation of the C-terminal 132 residues of CRX. Mutations in the CRX gene cause adCRD either by haploinsufficiency or by a dominant negative effect and demonstrate that CRX is essential for the maintenance of mammalian photoreceptors.

dl-alpha-tocopherol, a potent inhibitor of phorbol ester induced shape change of erythro- and megakaryoblastic leukemia cells.

Synthetic vitamin E, dl-alpha-tocopherol, added to a human erythroleukemia HEL and a megakaryoblastic leukemia, Meg-01, cell culture produced potent dose-dependent inhibition of phorbol ester-induced adhesion and of the morphologic changes accompanying it. The inhibition was reversible by withdrawal of supplemental vitamin E from the medium. dl-alpha-Tocopherol also inhibited protein kinase C activity both at baseline and after phorbol ester stimulation. Arachidonic acid stimulated protein kinase C activity of erythroleukemia cells and promoted their adhesion, an effect that was also inhibited by dl-alpha-tocopherol. Introduction of a protein kinase C-neutralizing antibody or a protein kinase C-inhibitor substrate into permeabilized HEL cells inhibited phorbol ester-induced adhesion and shape change. dl-alpha-Tocopherol also affected the cellular distribution of protein kinase C, shifting the major portion of the enzyme to the cytosol fraction and reducing phorbol ester-induced membrane association of the enzyme. Thus, protein kinase C appears to mediate shape change and adhesion, both of which are strongly inhibited by dl-alpha-tocopherol.

Synergism of hemopoietic growth factors on endothelial cell proliferation.

Endothelial cells, which are nonhemopoietic cells, express and/or produce most of the known hemopoietic receptors and cytokines. The biological role of these factors, and their respective receptors, on endothelial cells is still unknown. In this study, the authors assessed the effect of different hemopoietic growth factors, ie, interleukin-3 (IL-3), erythropoietin (EPO), macrophage-colony stimulating factor (M-CSF), granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage-colony stimulating factor (GM-CSF), singly or in conjunction with others, on proliferation and chemotaxis of human umbilical vein endothelial cells (HUVECs). They found growth stimulatory activity with IL-3, EPO, and GM-CSF and potent synergism between EPO and IL-3, less with IL-3 and GM-CSF, and none with EPO and either GM-CSF or G-CSF. All the singly tested hemopoietic growth factors stimulated the migration of HUVECs, but in conjunction with other factors, they did not show any additive or synergistic effect.

S-allylmercaptocysteine inhibits cell proliferation and reduces the viability of erythroleukemia, breast, and prostate cancer cell lines.

Organosulfur compounds are the biologically active components of allium vegetables. Many health benefits have been ascribed to them, including inhibition of carcinogenesis. Inasmuch as several of these thioallyl compounds are quite unstable and others are rapidly inactivated in the body, we have investigated one of the stable components present in aged garlic extract, S-allylmercaptocysteine (SAMC), in an effort to determine whether it can inhibit proliferation of cancer cells. Proliferation and viability of two erythroleukemia cell lines, HEL and OCIM-1, two hormone-responsive breast and prostate cancer cell lines, MCF-7 and CRL-1740, respectively, and normal human umbilical vein endothelial cells in response to different concentrations of SAMC were studied for up to two weeks. There were variations in sensitivity to this organosulfur compound in the different cell lines examined, but the two hormone-responsive cancer cell lines of breast and prostate clearly were far more susceptible to the growth-inhibitory influence of the thioallyl compound. The antiproliferative effect of SAMC was limited to actively growing cells. Human umbilical vein endothelial cells that had reached confluence escaped the reduction in viability so noticeable in the cancer cell lines tested. Our studies thus give evidence of a direct effect of SAMC on established cancer cells.

S-allylmercaptocysteine, a stable thioallyl compound, induces apoptosis in erythroleukemia cell lines.

The antiproliferative potential of S-allylmercaptocysteine (SAMC), a stable organosulfur compound of aged garlic extract, has been investigated using two erythroleukemia cell lines, HEL and OCIM-1. It induces a dose-dependent inhibition of cell growth with a 50% lethal dose of 0.046 mM for OCIM-1 cells and 0.093 mM for HEL cells. [3H]thymidine incorporation was reduced in cells treated with this thioallyl compound, and analysis of high-molecular-weight DNA showed fragmentation compatible with apoptosis. Flow cytometric analyses of DNA revealed an abnormal cell cycle progression in both types of erythroleukemia cells, with the major portion of the unsynchronized cells in the G2/M phase. Measurement of acid-soluble free sulfhydryl groups showed an initial increase in response to SAMC followed by a progressive dose-dependent decrease with extended incubation of cells. We conclude from these studies that SAMC is an effective antiproliferative agent against erythroleukemia cells that induces cell death by apoptosis.

dl-alpha-tocopherol induces apoptosis in erythroleukemia, prostate, and breast cancer cells.

Vitamin E, best known as a potent antioxidant, has been shown to have other functions that are not mediated by this activity. Recent reports have suggested that vitamin E may inhibit smooth muscle cell and also cancer cell growth. We have studied the effect of dl-alpha-tocopherol (vitamin E) on a series of well-established cancer cell lines that included two erythroleukemia cell lines and a hormone-responsive breast and prostate cancer cell line. Cell proliferation was examined in these cell lines, which were maintained at optimal growth conditions. A dose-dependent inhibition of cell growth was found in all cell lines examined, with the MCF-7 breast and CRL-1740 prostate cancer cell lines showing potent suppression of growth at 0.1 mM vitamin E, whereas the erythroleukemia cell lines, HEL and OCIM-1, responded only at > 0.25 mM vitamin E with inhibition of proliferation. Studies of [3H]thymidine incorporation showed that vitamin E supplementation reduced DNA synthesis in all cell lines. Analysis of high-molecular-weight DNA revealed extensive fragmentation, indicating apoptosis of all cell lines supplemented with vitamin E. Our studies thus give evidence of a general inhibition of cell proliferation by dl-alpha-tocopherol, with breast and prostate cancer cells distinctly more sensitive than erythroleukemia cells.

Scanning method to identify the molecular heterogeneity of delta-globin gene especially in delta-thalassemias: detection of three novel substitutions in the promoter region of the gene.

A scanning strategy for the detection of delta-globin gene mutations and polymorphisms is presented. This procedure is based on the denaturing gradient gel electrophoresis (DGGE) of four different artificially amplified DNA fragments which cover the promoter, the exons, as well as IVS I of the reported gene. To estimate the efficiency and sensitivity of the proposed procedure, we analysed the appropriate controls of delta-thalassemic carriers, uncharacterised delta-thalassemias and cases with normal hematological phenotype, but slightly increased (up to 3.5%) HbA2. DGGE results permitted the identification of delta-globin gene mutations and the polymorphism -199 (T-->C). Three novel base substitutions inside the promoter region of the gene [-65 (A-->G), -55 (T-->C), -36 (C-->A)], were also revealed. These changes are either linked in cis with other mutations or are responsible for thalassemias or for positive regulatory effect in delta-globin gene expression. The proposed experimental strategy consists of an accurate, rapid, safe and inexpensive screening procedure for establishing the molecular basis of delta-globin gene defects, suitable for the application for both research and diagnostics.

delta-Thalassemic phenotype due to two "novel" delta-globin gene mutations: CD11[GTC-->GGC (A8)-HbA2-Pylos] and CD 85[TTT-->TCT(F1)-HbA2-Etolia].

delta-Thalassemia reduces the expected HbA2 percentage, altering the normal as well as the beta-thalassemia trait phenotype. An attempt to elucidate the molecular basis of delta-thalassemia in the Greek population, revealed two cases with unknown molecular defects that presented low levels of HbA2 (about 1.5%). DNA sequence analysis of delta-globin gene identified two "novel" mutations in the coding regions of the gene; the cd11 (GTC-->GGC) resulting in the substitution of valine for glycine (:HbA2-Pylos) and the cd85(TTT-->TCT) resulting in the substitution of phenylalanine for serine (:HbA2-Etolia). Because these mutations are localized at the helical positions A8 and F1 of the HbA2 respectively, they potentially cause molecular instability of the tetramer, thus leading to reduced HbA2 percentage.

A new base substitution in the 5' regulatory region of the human Agamma globin gene is linked with the betaS gene.

A new T --> A base substitution, identified inside the 5' regulatory region of the human Agamma globin gene (Agamma-499 T -->A), is reported. This nucleotide change was found to be linked in cis with the mutation producing sickle cell anemia (CD6 GAG-->GTG: betaS gene).

HbF-Lesvos: an HbF variant due to a novel G gamma mutation (:G gamma 75 ATA-->ACA) detected in a Greek family.

A T-->C substitution at position 402 of the G gamma globin gene results in an isoleucine to threonine substitution at codon 75 of the G gamma globin chain and the formation of HbF-Lesvos [alpha2 G gamma2 75 (E19) Ile-->Thr].