A preliminary study to assess the value of the DNA chips SpectralChip to detect subtle constitutional chromosome imbalances

Comparative genomic hybridization on a microarray (microarray-CGH) allows to detect genomic chromosome imbalances. In order to assess its value to detect small chromosome imbalances observed in a clinical setting, using a DNA chip available commercially (Spectral Genomics, Houston, Texas, USA), we studied the DNA of 9 patients carrying a well characterized chromosome imbalance and the DNA of 11 patients where cytogenetic techniques such as high resolution banding karyotype, FISH using subtelomeric probes and comparative genomic hybridization on metaphase chromosomes conclude to a normal and/or balanced karyotype. A result was obtained for 19/20 patients. Failure of hybridization was observed for one patient. For all the other cases the sex of patients was correctly identified. Microarray-CGH was able to correctly diagnose the chromosome imbalance in 6/8 patients carrying such a defect i.e 9/11 imbalances (deletion or duplication) were detected. No chromosome imbalance was observed in 11 patients considered normal and/or balanced using cytogenetic techniques. Several clones were found to be polymorphic and required FISH studies to eliminate duplication or deletion. In conclusion, we think that this commercially available DNA chip might be useful to screen for chromosome imbalances. However, technical improvements are still necessary before using it in a clinical setting. Also, further studies are necessary to assess its sensitivity and specificity.     

Exhaled breath condensate cysteinyl leukotrienes are increased in children with exercise-induced bronchoconstriction

BACKGROUND: It is recognized that airway inflammation has a central role in the pathogenesis of asthma, but how it relates to exercise-induced bronchoconstriction (EIB) is not completely understood. OBJECTIVE: The aim of our study was to investigate the relationship between EIB and baseline concentrations of cysteinyl leukotrienes (Cys-LTs) and other inflammatory markers in exhaled breath condensate (EBC). METHODS: EBC was collected, and the fraction of exhaled nitric oxide (FE NO ) was measured in a group of 19 asthmatic children, after which they performed a treadmill exercise test. Fourteen healthy children were enrolled as control subjects. RESULTS: The asthmatic children were divided into the EIB group (decrease in FEV 1 , > or =12%) and the non-EIB group. The EBC was analyzed for the presence of Cys-LTs, leukotriene B 4 , and ammonia. Asthmatic patients with EIB (mean FEV 1 decrease, 23% +/- 3%) had higher Cys-LT concentrations than either asthmatic patients without EIB or control subjects (42.2 pg/mL [median] vs 11.7 pg/mL and 5.8 pg/mL; P < .05 and P < .001, respectively). Ammonia concentrations were lower in both the EIB and non-EIB groups than in control subjects (253.2 microM and 334.6 microM vs 798.4 microM; P < .01 and P < .05, respectively). No difference in EBC leukotriene B 4 levels was found among the 3 groups. Both asthmatic groups had higher FE NO levels than control subjects ( P < .001). EBC Cys-LT ( P < .01; r = 0.7) and FE NO ( P < .05; r = 0.5) values both correlated significantly with the postexercise FEV 1 decrease. CONCLUSION: this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV 1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.     

Diltiazem impairs maturation and functions of human dendritic cells

The aim of this study was to define the effects of diltiazem, a calcium antagonist drug used in cardiology and in clinical transplantation, on the differentiation and maturation of human dendritic cells (DC). Herein, we demonstrate that diltiazem, in association with granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), induces monocytes to differentiate into cells with many of the characteristic of DC. However, diltiazem-induced DC express high levels of mannose receptor and Fc gamma RII and, consequently, manifest a higher endocytic activity compared with GM-CSF+IL-4-induced DC. Importantly, diltiazem-induced DCs have an impaired responsiveness to lipopolysaccharide and CD40 ligand because they produce decreased levels of IL-12 and reveal a reduced ability to stimulate alloreactive T-cell responses as well as in inducing interferon-gamma producing Th1 cells. These effects may contribute to a decreased DC-dependent T-cell activation and may help to explain the immunoregulatory function of diltiazem and its effectiveness in preventing transplant rejection.     

Synthesis and Characterization of Segmented Poly(ether ester)s Containing H‐Bonding Units

A series of poly(ether ester)s containing different H‐bonding units (amide, carbamate, urea) was prepared by polycondensation in bulk, using Ti(OBu)₄ as a catalyst. The copolymers were obtained starting from PEG1000, 1,4‐butanediol, and a symmetrical, bis‐ester terminated monomer carrying H‐bonding units. These materials were designed for biomedical applications, in which ultimate biodegradability of the materials is required. The influence of the nature of the H‐bonding unit and of the length of the methylene spacer between H‐bonding groups on the thermal and solubility properties of copolymers was investigated. Amide containing copolymers were more thermally stable than ones containing carbamate, consistent with the observed behavior of the corresponding monomers. In most cases, differential scanning calorimetry (DSC) traces were quite complex because of phase separation and dependent on the applied cooling rate. Copolymers containing urea bonds were less soluble in most organic solvents, but their thermal properties were not significantly different than their amide containing counterparts.

Synthesis of amide‐based diester monomers.     

A novel mutation of varicella-zoster virus associated to fatal hepatitis.

BACKGROUND: Lethal varicella in immunocompetent hosts is rare and its pathogenesis is largely unknown. The discovery of glycoprotein E (gE) mutants showing attributes consistent with increased virulence in vitro and in animal models, provided a possible molecular mechanism underlying a more aggressive virus infection. However, these mutants have never been associated with unusually severe clinical cases. OBJECTIVES: To varicella-zoster virus (VZV) mutations that correlate with increased virulence. RESULTS: We report a case of fatal hepatitis caused by a VZV bearing a novel mutation on the 3B3 monoclonal antibody epitope of gE in an immunocompetent host. CONCLUSIONS: This report describes a mutant VZV responsible for an aggressive clinical course in an immunocompetent host. Linking these severe clinical presentations of VZV infection to virus mutations might provide insights into the underlying pathogenic mechanisms.     

IL-21 induces both rapid maturation of human CD34+ cell precursors towards NK cells and acquisition of surface killer Ig-like receptors

The NK cell maturation from CD34(+) Lin(-) hematopoietic cell precursors is a complex process that requires the direct contact with stromal cells and/or the synergistic effect of different cytokines. In this study we show that IL-21 is capable of inducing an accelerated NK cell maturation when added to cultures of CD34(+) Lin(-) cells isolated from human cord blood supplemented with IL-15, Flt3-L and SCF. After 25 days of culture, 50% of CD56(+) cells expressed various NK cell markers including the NKp46 and NKp30 triggering receptors, the CD94/NKG2A inhibitory receptor and CD16. At day 35, substantial fractions of NK cells expressed KIR, CD8 and CD2, i.e. surface markers expressed by mature NK cells, that are virtually undetectable in developing NK cells cultured in the absence of IL-21. Remarkably, similar to mature NK cells all these markers were included in the CD56(dim) cell fraction, while the CD56(bright) population was only composed of CD94/NKG2A(-) and CD94/NKG2A(+) cells. Thus, IL-21 allows the induction of a full NK cell maturation in vitro and offers an important tool for dissecting the molecular mechanisms involved in different steps of NK cell maturation and in the acquisition of a mature KIR repertoire.     

Production and Characterization of a Human Recombinant Monoclonal Fab Fragment Specific for Influenza A Viruses

A human recombinant monoclonal Fab fragment that specifically recognizes all the influenza A virus strains tested was produced in transformed Escherichia coli using the phage display technique. No strain of influenza B virus reacted with it. It was purified after four cycles of panning and by a single passage through an immunoaffinity column. About 1 mg of pure monoclonal antibody was obtained from 1 liter of culture medium in 3 working days. The Fab fragment reacted with a viral 27-kDa protein, which could reasonably be a matrix protein. Indirect immunofluorescence tests performed on virus-infected MDCK cells showed that this Fab fragment was at least equally efficient as other commercial monoclonal antibody-based systems in detecting influenza A viral infections. The potential advantages of human recombinant Fabs on murine monoclonal antibodies are discussed.     

Wilms tumor in patients with osteopathia striata with cranial sclerosis

Germline pathogenic variants in AMER1 cause osteopathia striata with cranial sclerosis (OSCS: OMIM 300373), an X-linked sclerosing bone disorder. Female heterozygotes exhibit metaphyseal striations in long bones, macrocephaly, cleft palate, and, occasionally, learning disability. Male hemizygotes typically manifest the condition as fetal or neonatal death. Somatically acquired variants in AMER1 are found in neoplastic tissue in 15–30% of patients with Wilms tumor; however, to date, only one individual with OSCS has been reported with a Wilms tumor. Here we present four cases of Wilms tumor in unrelated individuals with OSCS, including the single previously published case. We also report the first case of bilateral Wilms tumor in a patient with OSCS. Tumor tissue analysis showed no clear pattern of histological subtypes. In Beckwith–Wiedemann syndrome, which has a known predisposition to Wilms tumor development, clinical protocols have been developed for tumor surveillance. In the absence of further evidence, we propose a similar protocol for patients with OSCS to be instituted as an initial precautionary approach to tumor surveillance. Further evidence is needed to refine this protocol and to evaluate the possibility of development of other neoplasms later in life, in patients with OSCS.Subject terms: Genetics, Clinical genetics, Disease genetics