Perpendicularly magnetized Co/Pd-based magneto-resistive heterostructures on flexible substrates.

Flexible magneto-resistive heterostructures have received a great deal of attention over the past few years as they allow for new product paradigms that are not possible with conventional rigid substrates. While the progress and development of systems with longitudinal magnetic anisotropy on non-planar substrates has been remarkable, flexible magneto-resistive heterostructures with perpendicular magnetic anisotropy (PMA) have never been studied despite the possibility to obtain additional functionality and improved performance. To fill this gap, flexible PMA Co/Pd-based giant magneto-resistive (GMR) spin-valve stacks were prepared by using an innovative transfer-and-bonding strategy exploiting the low adhesion of a gold underlayer to SiO x /Si(100) substrates. The approach allows overcoming the limits of the direct deposition on commonly used polymer substrates, whose high surface roughness and low melting temperature could hinder the growth of complex heterostructures with perpendicular magnetic anisotropy. The obtained PMA flexible spin-valves show a sizeable GMR ratio (∼1.5%), which is not affected by the transfer process, and a high robustness against bending as indicated by the slight change of the magneto-resistive properties upon bending, thus allowing for their integration on curved surfaces and the development of a novel class of advanced devices based on flexible magneto-resistive structures with perpendicular magnetic anisotropy. Besides endowing the family of flexible electronics with PMA magneto-resistive heterostructures, the exploitation of the results might apply to high temperature growth processes and to the fabrication of other functional and flexible multilayer materials engineered at the nanoscale.

Focal nodular hyperplasia of the liver: an emerging complication of hematopoietic SCT in children.

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.

Characterization of a MADS FLOWERING LOCUS C-LIKE (MFL) sequence in Cichorium intybus: a comparative study of CiMFL and AtFLC reveals homologies and divergences in gene function.

In Arabidopsis thaliana, the ability to flower is mainly related to a floral repressor, FLOWERING LOCUS C (FLC), which is regulated through the vernalization pathway. The genes controlling the vernalization pathway seem to be only partially conserved in dicots other than the Brassicaceae. Cichorium intybus (chicory) is a biennial species belonging to the Asteraceae family, and it shows an obligate vernalization requirement for flowering. Cichorium intybus MADS (MCM1, Agamous, Deficiens, SRF) FLC-like (CiMFL) sequences were isolated in C. intybus by RT-PCR and their expression patterns characterized during plant development and in response to vernalization. The biological function of CiMFL was analysed by complementation of A. thaliana FRIGIDA (AtFRI);flc3. Resetting of MFL expression after vernalization was analysed during microsporogenesis. Before vernalization, CiMFL is mainly expressed in the axils of young leaves. Vernalization induced CiMFL down-regulation under a long-day photoperiod but not under a short-day photoperiod. Furthermore, together with a decrease in CiMFL transcripts, cold conditions induced changes in the morphology of the shoot apical meristem and in the transition to flowering. The biological function of CiMFL was found not to be conserved. Our results show that the regulation of CiMFL expression in time and space and in relation to environmental conditions is only partially conserved with respect to FLC isolated from A. thaliana. A model for flowering repression by CiMFL is proposed.

Expression of two maize putative nitrate transporters in response to nitrate and sugar availability.

A full-length cDNA encoding a putative high-affinity nitrate transporter (ZmNrt2.2) from maize was isolated and characterised, together with another previously identified transporter (ZmNrt2.1), in terms of phylogenesis, protein structure prediction and regulation of transcript accumulation in response to nitrate and sugar availability. The expression of both genes was evaluated by quantitative and semi-quantitative RT-PCR in response to nitrate and sugar supply and the in planta localisation of mRNA was studied by in situ hybridisation. Data obtained suggested similar genetic evolution and identical transmembrane structure prediction between the two deduced proteins, and differences in both regulation of their expression and mRNA localisation in response to nitrate, leading us to hypothesise a principal role for ZmNRT2.1 in the influx activity and the major involvement of ZmNRT2.2 in the xylem loading process. Our data suggest opposing sugar regulation by ZmNrt2.1 and ZmNrt2.2 transcription in the presence or absence of nitrate and the existence of both hexokinase-dependent and hexokinase-independent transduction mechanisms for the regulation of ZmNrt2.1 and ZmNrt2.2 expression by sugars.

Extracorporeal photochemotherapy may improve outcome in children with acute GVHD.

Acute GVHD (aGVHD) is a major cause of morbidity and mortality after unrelated BMT (UBMT). Our purpose was to analyze the role of extracorporeal photochemotherapy (ECP) in controlling grade II-IV aGVHD in children given UBMT. Of 41 consecutive children, 31 developed grade II-IV aGVHD after UBMT: 16 had a good response to steroids (GR group), whereas 15 underwent ECP (ECP group) within 100 days of UBMT. Eligibility criteria for starting ECP were steroid resistance, dependence or viral reactivations. Criteria for judging response to aGVHD treatment were that the resolution of all signs were considered a complete response (CR), at least a 50% improvement was classified as a partial response (PR) and stable or progressive disease was judged as no response (NR). On completing ECP, the CR rate was 73%, whereas the GR group had a CR rate of 56% by day 100. The 2-year overall survival and progression-free survival rates were 57 and 67% in the GR group vs 85 and 87% in the ECP group. Our data seem to suggest that ECP may improve outcome in patients after UBMT. These findings need to be confirmed in a larger population.

A prospective study of BK-virus-associated haemorrhagic cystitis in paediatric patients undergoing allogeneic haematopoietic stem cell transplantation.

We investigated the incidence, risk factors and outcome of haemorrhagic cystitis (HC) in paediatric patients undergoing HSCT and the predictive value of BK viruria and viraemia for developing HC. Over a period of 54 months, 74 patients were recruited. The cumulative incidence of HC was 22%. Among 15 patients prospectively monitored for BK viruria and viraemia, four patients developed HC of grade > or =II. This group, which had two consecutive BK positive samples, showed a sensitivity of 100%, a specificity of 82%, a positive predictive value of 67%, and negative predictive value of 100% for developing HC. Analysed by a receiver-operator characteristic curve (ROC), a urine BK load >9 x 10(6) genomic copies/ml had a sensitivity of 95% and specificity of 90%; while a blood BK load >1 x 10(3) genomic copies/ml had a sensitivity of 40% and a specificity of 93% for HC, respectively. In univariate analysis, BK positivity was the only factor significantly associated with HC. After a median follow-up of 1.8 years, patients with HC showed a lower overall survival, 40 vs 65%, P 0.01, and a lower event-free survival, 42 vs 62%, P 0.03, compared to patients without HC. We conclude that BK detection in urine and/or plasma is a specific predictor for developing HC.

Impact of cumulative anthracycline dose, preparative regimen and chronic graft-versus-host disease on pulmonary and cardiac function in children 5 years after allogeneic hematopoietic stem cell transplantation: a prospective evaluation on behalf of the EBMT Pediatric Diseases and Late Effects Working Parties.

This prospective study focused on risk factors and clinical outcome of pulmonary and cardiac late effects after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We prospectively evaluated 162 children by pulmonary function tests (PFTs) and cardiac shortening fraction (SF) before allo-HSCT and yearly up to the 5th year of follow-up. The 5-year cumulative incidence of lung and cardiac impairment was 35 (hazard rate=0.03) and 26% (hazard rate=0.06), respectively. Patients presenting abnormal PFTs and SF at last follow-up were 19 and 13%, respectively, with a median Lansky performance status of 90% (70-100). Chronic graft-versus-host disease (c-GVHD) was the major risk factor for reduced lung function in univariate (P=0.02) and multivariate analysis (P=0.02). Total body irradiation (TBI) alone and TBI together with pre-transplant anthracycline administration were significant risk factors for reduced cardiac function in univariate analysis, only (P=0.04 and 0.004, respectively). In conclusion, our prospective study demonstrates an asymptomatic post-allo-HSCT deterioration of pulmonary and cardiac function in some long-term survivors, who had been transplanted in childhood, and thus emphasizes the need for lifelong cardiopulmonary monitoring and the development of new strategies both to reduce pre-transplant cardiotoxic regimens and to treat more efficiently c-GVHD.

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

Apomixis is a mode of asexual reproduction through seed. Progeny produced by apomixis are clonal replicas of a mother plant. The essential feature of apomixis is that embryo sacs and embryos are produced in ovules without meiotic reduction or egg cell fertilisation. Thus, apomixis fixes successful gene combinations and propagates high fitness genotypes across generations. A more profound knowledge of the mechanisms that regulate reproductive events in plants would contribute fundamentally to understanding the evolution and genetic control of apomixis. Molecular markers were used to determine levels of genetic variation within and relationship among ecotypes of the facultative apomict Hypericum perforatum L. (2n = 4x = 32). All ecotypes were polyclonal, being not dominated by a single genotype, and characterised by different levels of differentiation among multilocus genotypes. Flow cytometric analysis of seeds indicated that all ecotypes were facultatively apomictic, with varying degrees of apomixis and sexuality. Seeds set by haploid parthenogenesis and/or by fertilisation of aposporic egg cells were detected in most populations. The occurrence of both dihaploids and hexaploids indicates that apospory and parthenogenesis may be developmentally uncoupled and supports two distinct genetic factors controlling apospory and parthenogenesis in this species. Cyto-embryological analysis showed that meiotic and aposporic processes do initiate within the same ovule: the aposporic initial often appeared evident at the time of megaspore mother cell differentiation. Our observations suggest that the egg cell exists in an active metabolic state before pollination, and that its parthenogenetic activation leading to embryo formation may occur before fertilisation and endosperm initiation.

In vitro buffering properties of 3 composite resins.

AIM: A dental composite resin, Ariston pHc, has been described as having a cariostatic effect by buffering acid saliva and preventing decalcification and infiltration of restorations. The buffering effect has been reported due to the release of OH- originated from the alkaline glass embedded in the resin. The release would occur only in the presence of low salivary pH values. The aim of this in vitro investigation was to evaluate pH variations induced by Ariston pHc and 2 other composite resins (P60 and Z100). METHODS: Eighteen samples were prepared for each composite and 5 specimens of each brand were embedded in artificial saliva according to Brugirar and Mazille, at 3 different pH values. A 1(st) group of 5 specimens of each tested resin was immersed in neutral artificial saliva at pH 7.7, a 2(nd) group in acidified artificial saliva at pH 5.45 and a 3(rd) group in alkalised saliva at pH 9.25. Three other samples of each resin were immersed in tubes containing distilled water at pH 7.23 and served as controls. Twelve tubes were filled only with neutral, alkalised and acidified artificial saliva and distilled water at the above mentioned pH values. Measurements of pH modifications were taken after 1, 3, 9, 14, 31 days. RESULTS. Ariston pHc raised the pH of distilled water up to 9.59 after 1 day, and to 8.42 after 31 days. This pH modification shown by Ariston pHc in distilled water, compared to those of the other 2 composites were statistically highly significant, with p<0.001, while the pH variations of saliva containing the 3 resins were negligible, except for acidified saliva with Ariston pHc, where a slight pH enhancement with some statistical significance (p=0.04) was found. However, acidified saliva without any resin embedded was found to shift to neutrality as well. CONCLUSION: These results strongly suggest that none of the 3 tested materials can achieve an effective buffering action in vitro on low salivary pH values. However, the ability of Ariston pHc to raise the pH in distilled water, and to a lesser degree in acidified saliva, suggests that an in vivo buffering effect cannot be excluded.

ALEX (artificial liver for extracorporeal xenoassistance): a new bioreactor containing a porcine autologous biomatrix as hepatocyte support. Preliminary results in an ex vivo experimental model.

Long-term maintenance of viability and expression of differentiated hepatocyte function is crucial for bioartificial liver support. We developed a new bioreactor design (ALEX), associated with a new extracellular autologous hepatocyte biomatrix (Porcine Autologous Biomatrix - PBM) support. To test this new bioreactor, we compared it to a standard BAL (BioArtificial Liver) cartridge in a ex vivo model using human plasma added to bilirubin, ammonium and lidocaine. A pathology study was performed on both bioreactors. The results suggest that ALEX allows a maximal contact between the perfusing plasma and the liver cells and a proper hepatocyte support by a cell-to-matrix attachment. ALEX is a suitable cell support bioreactor, guaranteeing long-term maintenance of the metabolic activity of hepatocytes when compared to a standard BAL cartridge.

The maize WD-repeat gene ZmRbAp1 encodes a member of the MSI/RbAp sub-family and is differentially expressed during endosperm development.

Members of the MSI/RbAp sub-family of WD-repeat proteins are widespread in eukaryotic organisms and form part of multiprotein complexes that are involved in various biological pathways, including chromatin assembly, regulation of gene transcription, and cell division. In this study we report the isolation and characterization of a cDNA sequence from Zea mays, which encodes an RbAp-like protein (ZmRbAp1) that binds acetylated histones H3 and H4 and suppresses mutations that have a negative effect on the Ras/cAMP pathway in yeast. The ZmRbAp genes form a gene family and are expressed in different tissues of Z. mays L. plants. Determination of its expression pattern during maize seed development revealed that ZmRbAp transcripts are abundant during the initial stages of endosperm formation. In addition, the transcripts are specifically localized in shoot apical meristem and leaf primordia of the embryo. A possible role for the ZmRbAp genes in early endosperm differentiation and plant development is discussed.

Successful unrelated bone marrow transplantation for Shwachman-Diamond syndrome.

A 5-year-old boy with Shwachman-Diamond syndrome underwent unrelated HLA-identical bone marrow transplantation for severe pancytopenia. Conditioning was with busulfan, thiotepa and cyclophosphamide plus rabbit anti-lymphocyte serum. Engraftment for neutrophils and platelets was observed on days +18 and +41, respectively. Transplant-related side-effects were mild and transient. After a follow-up of 32 months, the patient is alive and enjoys a normal life, off any immunosuppressives. Immunological and hematological reconstitution is complete while other phenotypic characteristics (pancreatic insufficiency, short stature, femur dysostosis) are stable. Although experience in this field is scarce, we speculate that bone marrow failure in Shwachman-Diamond syndrome (even if not linked to the appearance of clonal disorders or leukemic transformation) is an indication for bone marrow transplantation and may be associated with a better outcome.

Analysis of gene expression during flowering in apomeiotic mutants of Medicago spp.: cloning of ESTs and candidate genes for 2n eggs.

Mutants showing features of apomixis have been documented in alfalfa (Medicago sativa L.), a natural outcrossing sexual species. A differential display of mRNAs that combines cDNA-AFLP markers and bulked segregant analysis was carried out with the aim of selecting expressed sequence tags (ESTs) and cloning candidate genes for apomeiosis in mutants of alfalfa characterized by 2n egg formation at high frequencies. The approach enabled us to select either mutant- or wild type-specific transcript derived-fragments and to detect transcriptional changes potentially related to 2n eggs. Sequence alignments of a subset of 40 polymorphic clones showed significant homologies to genes of known function. An EST with identity to a ß-tubulin gene, highly expressed in the wild type and poorly expressed in the apomeiotic mutants, and an EST with identity to a Mob1-like gene, qualitatively polymorphic between pre- and post-meiotic stages, were selected as candidate genes for apomeiosis because of their putative roles in the cell cycle. A number of clone-specific primers were designed for performing both 5' and 3' rapid amplification of cDNA ends to obtain the full-length clones. Southern blot hybridization revealed that both clones belong to a multi-gene family with a minimum of three genomic DNA members each. Northern blot hybridization of total RNA samples and in situ hybridization of whole buds enabled the definition of their temporal and spatial expression patterns in reproductive organs. Experimental achievements towards the elucidation of apomeiotic megasporogenesis in alfalfa are presented and discussed.

Impact of thrombotic thrombocytopenic purpura on leukemic children undergoing bone marrow transplantation.

Thrombotic thrombocytopenic purpura (TTP) has emerged as one of the main transplant-related complications over the last 15 years. The current study defines the incidence and the risk factors for the occurrence of TTP in 131 consecutive leukemic children who were transplanted between January 1994 and December 1997 at four Italian pediatric centers. Patients with ALL (101), AML (21), MDS (9), underwent an HLA-identical sibling BMT (82) or an HLA-identical unrelated BMT (49), receiving a conditioning regimen consisting of high-dose chemotherapy in 24 patients and of F-TBI combined with high-dose chemotherapy in 107 patients. The diagnosis of TTP was retrospectively evaluated on the basis of parallel criteria. TTP treatment varied according to the protocol of each treatment center. Twenty-eight of 131 patients (21.4%) developed TTP at a median of 46 days (range 21-80) after BMT. Multivariate analysis demonstrated that the risk of TTP was higher in patients who underwent unrelated BMT (P value = 0.02). Acute GVHD, stage of disease at BMT, conditioning with TBI, gender, age, did not appear to be associated with the occurrence of TTP. As to the outcome, TTP resolved in 19 patients while in nine it was the principal cause of death (32.1%). In patients with TTP, LDH peak value was the only statistically significant factor (P = 0.001) related to severe TTP. In conclusion, our experience demonstrates that leukemic children undergoing BMT, especially from an unrelated donor, should be carefully assessed for TTP which appears to be a severe and relatively common transplant-related complication when strict diagnostic criteria are applied.

Diamond-Blackfan anaemia in the Italian population.

Diamond-Blackfan anaemia (DBA) is a congenital disease characterized by defective erythroid progenitor maturation: 30% of patients have congenital malformations. The link between these malformations and defective erythropoiesis is unclear: a defect in a molecule acting both on embryo development and haemopoiesis has been proposed. Inheritance is autosomal dominant in most familial cases, but recessive families have also been reported. Many cases are sporadic. A DBA locus has been mapped on chromosome 19q13.2 (Gustavsson et al, 1997), but several families unlinked to this locus have also been reported (Gustavsson et al, 1998). This paper presents clinical, epidemiological and molecular data for DBA in the Italian population. Segregation analysis of 19q markers in patients with DBA showed exclusion of this locus in 5/12 families with inherited DBA. There was evidently locus heterogeneity for DBA in this population. A new microdeletion was identified in one patient. Other families, in which DBA segregates concordantly with the 19q critical region, suggest incomplete penetrance and expressivity of the DBA gene.

Successful treatment of secondary acute myeloid leukemia relapsing after allogeneic bone marrow transplantation with donor lymphocyte infusion failed to prevent recurrence of primary disease: a case report.

We report a case of therapy-related secondary acute myeloid leukemia occurring in a patient during treatment for anaplastic large cell lymphoma. In spite of response to induction chemotherapy and prompt bone marrow transplantation from his matched sister, the patient experienced an early leukemia relapse within 3 months of the transplant. Treatment with oral etoposide for 3 weeks followed by donor lymphocyte infusion achieved a 7-month remission from leukemia without any further treatment. Unfortunately, the patient suffered a recurrence of the primary anaplastic large cell lymphoma that was treated by resuming chemotherapy and local radiotherapy. The patient died 20 months after DLI, still in CR for his leukemia, due to ALCL progression.

The breakpoints of a constitutional inversion of chromosome 9 associated with haemophagocytic lymphohistiocytosis are not linked to the disease gene.

Haemophagocytic lymphohistiocytosis (HLH) is a severe disorder of early infancy consistent with an autosomal recessive inheritance. Neither the genetic locus nor the biochemical defect is known for the disease. A constitutional pericentric inversion of chromosome 9, with breakpoints in bands 9p23 and 9q31, has been reported in a case of HLH, suggesting a possible relationship between this chromosome abnormality and the disease. We investigated such an association, performing a genetic linkage analysis in a set of five consanguineous HLH families. 27 polymorphic markers on chromosome 9 were studied, excluding most of chromosome 9 as a putative site for the HLH gene.