3,225 research outputs found
ITGB2 mutation combined with deleted ring 21 chromosome in a child with leukocyte adhesion deficiency
Leukocyte adhesion deficiency type 1(LAD-1) is a rare autosomal recessive primary immunodeficiency caused by defects in the ITGB2 gene located on chromosome 21q22. Clinically, LAD-1 patients are characterized by recurrent infections, slow wound healing and dystrophic scars after skin injuries, associated with persistent neutrophilia. The severity of symptoms is related to the level of CD11/CD18 expression on patients’ leucocytes and those with less than 1% expression treated with hematopoietic stem cell transplant (HSCT).
We present a child affected by LAD-1 who received HSCT from a matched unrelated donor. Molecular analysis revealed apparent homozygosis for a point mutation in the ITGB2 gene, only the mother however was carrier of the mutation. Cytogenetic and FISH analysis showed the presence of a de-novo ring chromosome 21. Whole Genome Analysis with the Affymetrix GeneChip Human Mapping 250K NspI array confirmed in the child the presence of a de novo deletion of the chromosomal region 21q22.3-qter, where the ITGB2 gene maps.
While HSCT resulted in successful engraftment and correction of the immunodeficiency, all the phenotypic features of ring (21) syndrome with a deletion of a 4.6Mb (including 69 genes) clearly remained unchange
A mutation in caspase-9 decreases the expression of BAFFR and ICOS in patients with immunodeficiency and lymphoproliferation
Lymphocyte apoptosis is mainly induced by either death receptor-dependent activation of caspase-8 or mitochondria-dependent activation of caspase-9. Mutations in caspase-8 lead to autoimmunity/lymphoproliferation and immunodeficiency. This work describes a heterozygous H237P mutation in caspase-9 that can lead to similar disorders. H237P mutation was detected in two patients: Pt1 with autoimmunity/lymphoproliferation, severe hypogammaglobulinemia and Pt2 with mild hypogammaglobulinemia and Burkitt lymphoma. Their lymphocytes displayed defective caspase-9 activity and decreased apoptotic and activation responses. Transfection experiments showed that mutant caspase-9 display defective enzyme and proapoptotic activities and a dominant-negative effect on wild-type caspase-9. Ex vivo analysis of the patients' lymphocytes and in vitro transfection experiments showed that the expression of mutant caspase-9 correlated with a downregulation of BAFFR (B-cell-activating factor belonging to the TNF family (BAFF) receptor) in B cells and ICOS (inducible T-cell costimulator) in T cells. Both patients carried a second inherited heterozygous mutation missing in the relatives carrying H237P: Pt1 in the transmembrane activator and CAML interactor (TACI) gene (S144X) and Pt2 in the perforin (PRF1) gene (N252S). Both mutations have been previously associated with immunodeficiencies in homozygosis or compound heterozygosis. Taken together, these data suggest that caspase-9 mutations may predispose to immunodeficiency by cooperating with other genetic factors, possibly by downregulating the expression of BAFFR and ICO
Assessing forest availability for wood supply in Europe
The quantification of forests available for wood supply (FAWS) is essential for decision-making with regard to
the maintenance and enhancement of forest resources and their contribution to the global carbon cycle. The
provision of harmonized forest statistics is necessary for the development of forest associated policies and to
support decision-making. Based on the National Forest Inventory (NFI) data from 13 European countries, we
quantify and compare the areas and aboveground dry biomass (AGB) of FAWS and forest not available for wood
supply (FNAWS) according to national and reference definitions by determining the restrictions and associated
thresholds considered at country level to classify forests as FAWS or FNAWS.
FAWS represent between 75 and 95 % of forest area and AGB for most of the countries in this study. Economic
restrictions are the main factor limiting the availability of forests for wood supply, accounting for 67 % of the
total FNAWS area and 56 % of the total FNAWS AGB, followed by environmental restrictions. Profitability, slope
and accessibility as economic restrictions, and protected areas as environmental restrictions are the factors most
frequently considered to distinguish between FAWS and FNAWS. With respect to the area of FNAWS associated
with each type of restriction, an overlap among the restrictions of 13.7 % was identified. For most countries, the differences in the FNAWS areas and AGB estimates between national and reference definitions ranged from 0 to
5 %. These results highlight the applicability and reliability of a FAWS reference definition for most of the
European countries studied, thereby facilitating a consistent approach to assess forests available for supply for
the purpose of international reportinginfo:eu-repo/semantics/publishedVersio
A novel large deletion and single nucleotide insertion in the Wiskott-Aldrich syndrome protein gene
Deletion mutations of WAS are relatively rare and the precise localization of large deletions in the genome has rarely been described in previous studies. We report here a five-months-old boy with a large deletion mutation in WAS that completely abolished protein expression. In order to localize the deletion, a 2816 bp-length sequence that spans between exons 9 and 12 was amplified. PCR amplification of the patient's sample revealed a single band of about 1 kb in contrast to the 2816 bp amplicon in the control. Genomic DNA sequencing of the patient revealed a 1595 bp deletion and an adenine insertion (g.5247_6841del1595insA). This large deletion of WAS resulted in partial loss of exon 10 and intron 11, and a complete loss of intron 10 and exon 11. This article is protected by copyright. All rights reserved
The effects of iCVD film thickness and conformality on the permeability and wetting of MD membranes
Membranes possessing high permeability to water vapor and high liquid entry pressure (LEP) are necessary for efficient membrane distillation (MD) desalination. A common technique to prepare specialized MD membranes consists of coating a hydrophilic or hydrophobic base membrane with a low surface-energy material. This increases its liquid entry pressure, making the membrane suitable for MD. However, in addition to increasing LEP, the surface-coating may also decrease permeability of the membrane by reducing its average pore size. In this study, we quantify the effects of initiated chemical vapor deposition (iCVD) polymer coatings on membrane permeability and LEP. We consider whether the iCVD films should have minimized thickness or maximized non-conformality, in order to maximize the permeability achieved for a given value of LEP. We determined theoretically that permeability of a single pore is maximized with a highly non-conformal iCVD coating. However, the overall permeability of a membrane consisting of many pores is maximized when iCVD film thickness is minimized. We applied the findings experimentally, preparing an iCVD-treated track-etched polycarbonate (PCTE) membrane and testing it in a permeate gap membrane distillation (PCMD) system. This study focuses on membranes with clearly defined, cylindrical pores. However, we believe that the principles we discuss will extend to membranes with more complex pore architectures. Overall, this work indicates that the focus of surface-coating development should be on minimizing film thickness, not on increasing their non-conformality.MIT & Masdar Institute Cooperative Program (02/MI/MI/CP/11/07633/GEN/G/00)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (W911NF-13-d-0001
Missense mutations in the Fas gene resulting in autoimmune lymphoproliferative syndrome: a molecular and immunological analysis
Programmed cell death (or apoptosis) is a physiological process essential to the normal development and homeostatic maintenance of the immune system. The Fas/Apo-1 receptor plays a crucial role in the regulation of apoptosis, as demonstrated by lymphoproliferation in MRL-lpr/lpr mice and by the recently described autoimmune lymphoproliferative syndrome (ALPS) in humans, both of which are due to mutations in the Fas gene. We describe a novel family with ALPS in which three affected siblings carry two distinct missense mutations on both the Fas gene alleles and show lack of Fas-induced apoptosis. The children share common clinical features including splenomegaly and lymphadenopathy, but only one developed severe autoimmune manifestations. In all three siblings, we demonstrated the presence of anergic CD3+CD4-CD8- (double negative, [DN]) T cells; moreover, a chronic lymphocyte activation was found, as demonstrated by the presence of high levels of HLA-DR expression on peripheral CD3+ cells and by the presence of high levels of serum activation markers such as soluble interleukin-2 receptor (slL-2R) and soluble CD30 (sCD30)
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