Cathodoluminescence Study of Defects in III-V Substrates and Structures

Solid state detector cathodoluminescence studies of semiconducting and semi-insulating GaAs and InP crystals, were performed. The origin of the dislocation contrast in GaAs:Si doped substrates, in the carrier concentration range from 1016 to 6 · 1018 cm-3, were discussed. The image contrast was explained on the basis of the emission efficiency versus carrier concentration curve, obtained in the transmission mode. Single dislocations and dislocation arrangements in addition to growth striations, clusters and precipitate-like microdefects were evidenced. The above mentioned microdefects were detected in GaAs: Te, S and Si doped and InP: Sn doped specimens. Commercial InP:Sn and S doped crystals by different manufacturers were also tested in order to perform a comprehensive evaluation of the defect content. Finally, combining emission and transmission cathodoluminescence, Si and Ge detectors at different beam energies, the defect distribution of different layers in simple and double heterostructures was determined in a non-destructive way. MBE InGaAs/InP and LPE InGaAsP/InP structures, employed as semiconductor detectors and lasers, were investigated

Consequences of the marine climate and ecosystem shift of the 1980-90s on the Ligurian Sea biodiversity (NW Mediterranean Sea)

A rapid temperature increase in the 1980-90s has been accompanied by dramatic and unprecedented changes in the biota and communities of the Ligurian Sea. This review uses existing historical series (a few of which have been purposely updated) to assess extent and consequences of such changes. A number of warm-water species, previously absent or occasional in the comparatively cold Ligurian Sea, has recently established thanks to warmer winters. Occurrence among them of invasive alien species is causing concern because of their capacity of outcompeting autochthonous species. Summer heatwaves, on the other hand, caused mass mortalities in marine organisms, some of which found refuge at depth. New marine diseases appeared, as well as other dysfunctions such as the formation of mucilage aggregates that suffocated and entangled benthic organisms. Human pressures have combined with climate change to cause phase shifts (i.e., abrupt variations in species composition and community structure) in different habitats, such as the pelagic environment, seagrass meadows, rocky reefs, and marine caves. These phase shifts implied biotic homogenization, reduction of diversity, and dominance by invasive aliens, and may be detrimental to the resilience of Ligurian Sea ecosystems. Another phase of rapid warming has possibly started in the 2010s and there are clues pointing to a further series of biological changes, but data are too scarce to date for proper assessment. Only well addressed long-term studies will help understanding the future dynamics of Ligurian Sea ecosystems and their possibilities of recovery

A DNA target-enrichment approach to detect mutations, copy number changes and immunoglobulin translocations in multiple myeloma.

Genomic lesions are not investigated during routine diagnostic workup for multiple myeloma (MM). Cytogenetic studies are performed to assess prognosis but with limited impact on therapeutic decisions. Recently, several recurrently mutated genes have been described, but their clinical value remains to be defined. Therefore, clinical-grade strategies to investigate the genomic landscape of myeloma samples are needed to integrate new and old prognostic markers. We developed a target-enrichment strategy followed by next-generation sequencing (NGS) to streamline simultaneous analysis of gene mutations, copy number changes and immunoglobulin heavy chain (IGH) translocations in MM in a high-throughput manner, and validated it in a panel of cell lines. We identified 548 likely oncogenic mutations in 182 genes. By integrating published data sets of NGS in MM, we retrieved a list of genes with significant relevance to myeloma and found that the mutational spectrum of primary samples and MM cell lines is partially overlapping. Gains and losses of chromosomes, chromosomal segments and gene loci were identified with accuracy comparable to conventional arrays, allowing identification of lesions with known prognostic significance. Furthermore, we identified IGH translocations with high positive and negative predictive value. Our approach could allow the identification of novel biomarkers with clinical relevance in myeloma

RSSsite: a reference database and prediction tool for the identification of cryptic Recombination Signal Sequences in human and murine genomes

Recombination signal sequences (RSSs) flanking V, D and J gene segments are recognized and cut by the VDJ recombinase during development of B and T lymphocytes. All RSSs are composed of seven conserved nucleotides, followed by a spacer (containing either 12 ± 1 or 23 ± 1 poorly conserved nucleotides) and a conserved nonamer. Errors in V(D)J recombination, including cleavage of cryptic RSS outside the immunoglobulin and T cell receptor loci, are associated with oncogenic translocations observed in some lymphoid malignancies. We present in this paper the RSSsite web server, which is available from the address http://www.itb.cnr.it/rss. RSSsite consists of a web-accessible database, RSSdb, for the identification of pre-computed potential RSSs, and of the related search tool, DnaGrab, which allows the scoring of potential RSSs in user-supplied sequences. This latter algorithm makes use of probability models, which can be recasted to Bayesian network, taking into account correlations between groups of positions of a sequence, developed starting from specific reference sets of RSSs. In validation laboratory experiments, we selected 33 predicted cryptic RSSs (cRSSs) from 11 chromosomal regions outside the immunoglobulin and TCR loci for functional testing

Relevance of diagnostic investigations in chronic inflammatory demyelinating poliradiculoneuropathy: Data from the Italian CIDP database

The objective of our work was to report the clinical features and the relevance of diagnostic investigations in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We retrospectively reviewed data from patients with a clinical diagnosis of CIDP included in a national database. Among the 500 included patients with a clinical diagnosis of CIDP, 437 patients (87%) fulfilled the European Federation of Neurological Societies and Peripheral Nerve Society criteria for CIDP (definite in 407, probable in 26, possible in four). In 352 patients (86%) motor nerve conduction abnormalities consistent with demyelination were sufficient for the diagnosis of definite CIDP. In 55 patients, this diagnosis required the addition of one or two (from probable or from possible CIDP, respectively) supportive tests, while in 20 cases they improved the diagnosis from possible to probable CIDP, seven patients did not change diagnosis. Considering these 85 patients, cerebrospinal fluid studies were performed in 79 cases (93%) upgrading the certainty of diagnosis in 59% of examined patients. Sensory nerve conduction studies (NCS) were performed in 85% of patients with an improvement of diagnosis in 32% of cases. Nerve biopsy and ultrasound and magnetic resonance imaging (US/MRI) exams resulted positive in about 40% of examined patients, but they were performed in few patients (7 patients and 16 patients, respectively). A response to the therapy was present in 84% of treated patients (n = 77), contributing to support the diagnosis in 40 patients in whom the other supportive criteria were not sufficient. In most patients with CIDP the diagnosis is possible solely with motor NCS while other investigations may help improving the diagnosis in a minority of patients

Frequency and time to relapse after discontinuing 6-month therapy with IVIg or pulsed methylprednisolone in CIDP

Background: We reported that 6-month therapy with intravenous immunoglobulin (IVIg) was more frequently effective or tolerated than intravenous methylprednisolone (IVMP) in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We now retrospectively compared the proportion of patients who eventually worsened after discontinuing therapy and the median time to clinical worsening. Methods: By March 2013, data were available from 41 of the 45 patients completing the trial with a median follow-up after therapy discontinuation of 42 months (range 1-60). Three patients withdrew during the original study and one failed to respond to either of the therapies. No patient received a diagnosis alternative to CIDP during the follow-up. Results: Twenty-eight of the 32 patients treated with IVIg (as primary or secondary therapy after failing to respond to IVMP) improved after therapy (87.5%) as compared with 13 of the 24 patients treated with IVMP as primary or secondary therapy (54.2%). After a median follow-up of 42 months (range 1-57), 24 out of 28 patients responsive to IVIg (85.7%) worsened after therapy discontinuation. The same occurred in 10 out of 13 patients (76.9%) responsive to IVMP (p=0.659) after a median follow-up of 43 months (range 7-60). Worsening occurred 1-24 months (median 4.5) after IVIg discontinuation and 1-31 months (median 14) after IVMP discontinuation (p=0.0126). Conclusions: A similarly high proportion of patients treated with IVIg or IVMP eventually relapse after therapy discontinuation but the median time to relapse was significantly longer after IVMP than IVIg. This difference may help to balance the more frequent response to IVIg than to IVMP in patients with CIDP

Role of Rituximab Addition to First-line Chemotherapy Regimens in Nodular Lymphocyte-predominant Hodgkin Lymphoma: A Study by Fondazione Italiana Linfomi

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare entity whose neoplastic cells retain a B-cell phenotype with expression of CD20. Radiotherapy is recommended for favorable stage IA disease while for other stages guidelines suggest therapeutic strategies similar to those used for classic HL. The role of rituximab, although quite widespread, is not completely elucidated. We retrospectively analyzed baseline characteristics of 308 consecutive patients with NLPHL diagnosed in 19 Italian centers from 2000 to 2018. With a median follow-up of 8.4 years (interquartile range: 4.5-12.4) for treated patients, median overall survival (OS) was not reached and estimated 5-year OS was 97.8% and 5-year progression-free survival (PFS) was 84.5%. Five-year cumulative incidence of histological transformation was 1.4%, 95% confidence interval (CI), 0.5%-3.8%. After adjusting for lymphocyte count, splenic involvement, bulky disease and B symptoms (fever, drenching night sweats, unintentional loss >10% of body weight within the preceding 6 months), patients with stage II or more showed superior PFS with immunochemotherapy in comparison to chemotherapy alone (hazard ratio = 0.4, 95% CI, 0.2-0.8; P = 0.015). Our data suggest an advantage of the use of rituximab combined with chemotherapy ± radiotherapy in the treatment of stage II-III-IV NLPHL