Adicionales de obra y enriquecimiento indebido en el marco del Decreto Legislativo Nº 1017 – Ley de Contrataciones del Estado y su Reglamento

Esta tesis tiene como objetivo brindar una alternativa de solución a la deficiencia legal en la que incurre el Decreto Legislativo N° 1 071 Ley de Contrataciones del Estado, al momento de regular el tema de Adicionales de Obra y su desarrollo dentro del Arbitraje; de tal manera que los conflictos generados a raíz de los contratos celebrados entre los particulares y el Estado encuentran en el arbitraje un medio idóneo para garantizar su solución ágil y rápida, siendo ésta la forma prescrita en dicha norma para la solución de conflictos Consecuentemente si bien la realización del arbitraje al momento de decidir sobre los adicionales de obra se funda en la voluntad de las partes, en el ámbito de las contrataciones públicas, la prohibición de discutir en un proceso arbitral los adicionales de obra; ha dado paso a que los contratistas, en su afán de querer recobrar aquello que invirtieron en prestaciones no contempladas en el Expediente Técnico y que resultaban fundamentales para alcanzar la finalidad del contrato, recurran a la figura del enriquecimiento indebido en el ámbito arbitral, no existiendo unanimidad en el laudo arbitral al momento del surgimiento de este tipo de controversias. Es importante mencionar también que la presente investigación ha sido desarrollada, con un análisis Minucioso y didáctico del tema, para lo cual se ha tomado en cuenta la normatividad vigente, así como también los diversos pronunciamientos de las entidades encargadas de regular sobre contrataciones y los criterios relevantes de la doctrina. Para Finalizar, esperamos que este trabajo sea de gran ayuda y sirva de consulta para el enriquecimiento doctrinario de la matera

Putative role of circulating human papillomavirus DNA in the development of primary squamous cell carcinoma of the middle rectum: a case report

Here we present the case of a patient affected by rectal squamous cell carcinoma in which we demonstrated the presence of Human Papillomavirus (HPV) by a variety of techniques. Collectively, the virus was detected not only in the tumor but also in some regional lymph nodes and in non-neoplastic mucosa of the upper tract of large bowel. By contrast, it was not identifiable in its common sites of entry, namely oral and ano-genital region. We also found HPV DNA in the plasma-derived exosome. Next, by in vitro studies, we confirmed the capability of HPV DNA-positive exosomes, isolated from the supernatant of a HPV DNA positive cell line (CaSki), to transfer its DNA to human colon cancer and normal cell lines. In the stroma nearby the tumor mass we were able to demonstrate the presence of virus DNA in the stromal compartment, supporting its potential to be transferred from epithelial cells to the stromal ones. Thus, this case report favors the notion that human papillomavirus DNA can be vehiculated by exosomes in the blood of neoplastic patients and that it can be transferred, at least in vitro, to normal and neoplastic cells. Furthermore, we showed the presence of viral DNA and RNA in pluripotent stem cells of non-tumor tissue, suggesting that after viral integration (as demonstrated by p16 and RNA in situ hybridization positivity), stem cells might have been activated into cancer stem cells inducing neoplastic transformation of normal tissue through the inactivation of p53, p21, and Rb. It is conceivable that the virus has elicited its oncogenic effect in this specific site and not elsewhere, despite its wide anatomical distribution in the patient, for a local condition of immune suppression, as demonstrated by the increase of T-regulatory (CD4/CD25/FOXP3 positive) and T-exhausted (CD8/PD-1positive) lymphocytes and the M2 polarization (high CD163/CD68 ratio) of macrophages in the neoplastic microenvironment. It is noteworthy that our findings depicted a static picture of a long-lasting dynamic process that might evolve in the development of tumors in other anatomical sites. Copyright © 2019 Ambrosio, Vernillo, De Carolis, Carducci, Mundo, Ginori, Rocca, Nardone, Lucenti Fei, Carfagno, Lazzi, Cricca and Tosi

p66Shc deficiency in the Eμ-TCL1 mouse model of chronic lymphocytic leukemia enhances leukemogenesis by altering the chemokine receptor landscape

The Shc family adaptor p66Shc acts as a negative regulator of proliferative and survival signals triggered by the B Cell Receptor and, by enhancing the production of reactive oxygen species, promotes oxidative stress-dependent apoptosis. Additionally, p66Shc controls the expression and function of chemokine receptors that regulate lymphocyte traffic. Chronic lymphocytic leukemia cells have a p66Shc expression defect which contributes to their extended survival and correlates with poor prognosis. We have analyzed the impact of p66Shc ablation on disease severity and progression in the mouse model of chronic lymphocytic leukemia Eμ-TCL1. We show that Eμ-TCL1/p66Shc-/- mice develop an aggressive disease that has an earlier onset, a higher incidence and leads to earlier death compared to Eμ-TCL1 mice. Eμ-TCL1/p66Shc-/- mice display substantial leukemic cell accumulation in both nodal and extranodal sites. The target organ selectivity correlates with an upregulation of chemokine receptors whose ligands are expressed therein. This also applies to chronic lymphocytic leukemia cells, where chemokine receptor expression and extent of organ infiltration were found to inversely correlate with their p66Shc expression levels. p66Shc expression declined with disease progression in Eμ-TCL1 mice and could be restored by treatment with the Bruton tyrosine kinase inhibitor Ibrutinib. Our results highlight p66Shc deficiency as an important factor in chronic lymphocytic leukemia progression and severity and underscore p66Shc expression as a relevant therapeutic target

MicroRNAs sequencing unveils distinct molecular subgroups of plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is an aggressive lymphoma, often arising in the context of immunodeficiency and associated with Epstein-Barr virus (EBV) infection. The most frequently detected genetic alteration is the deregulation of MYC gene through the translocation - t(8;14)(q24;q32). The diagnosis of PBL is often challenging because it has an overlap in morphology, immunophenotype, cytogenetics and virus association with other lymphomas and plasma cell neoplasms; further, its molecular basis remains elusive. In the present study we aimed to better define the possible contribution of EBV infection as well as miRNA deregulation in PBL pathogenesis. We studied 23 cases of PBL, 19 Burkitt lymphomas (BL), and 17 extra-medullary plasmacytoma (EMPC). We used qPCR and immunohistochemistry to assess EBV latency patterns, while micro-RNA (miRNA) profiling was performed by next generation sequencing (Illumina) and validated by qPCR. Our analysis revealed a non-canonical EBV latency program with the partial expression of some proteins characterizing latency II and the activation of an abortive lytic cycle. Moreover, we identified miRNA signatures discriminating PBL from BL and EMPC. Interestingly, based on the miRNA profile, PBL appeared constituted by two discrete subgroups more similar to either BL or EMPC, respectively. This pattern was confirmed in an independent set of cases studied by qPCR and corresponded to different clinico-pathological features in the two groups, including HIV infection, MYC rearrangement and disease localization. In conclusion, we uncovered for the first time 1) an atypical EBV latency program in PBL; 2) a miRNA signature distinguishing PBL from the closest malignant counterparts; 3) the molecular basis of PBL heterogeneity

TGF-β concentrations and activity are down-regulated in the aqueous humor of patients with neovascular age-related macular degeneration

Controversy still exists regarding the role of the TGF-β in neovascular age-related macular degeneration (nAMD), a major cause of severe visual loss in the elderly in developed countries. Here, we measured the concentrations of active TGF-β1, TGF-β2, and TGF-β3 by ELISA in the aqueous humor of 20 patients affected by nAMD, who received 3 consecutive monthly intravitreal injections of anti-VEGF-A antibody. Samples were collected at baseline (before the first injection), month 1 (before the second injection), and month 2 (before the third injection). The same samples were used in a luciferase-based reporter assay to test the TGF-β pathway activation. Active TGF-β1 concentrations in the aqueous humor were below the minimum detectable dose. Active TGF-β2 concentrations were significantly lower at baseline and at month 1, compared to controls. No significant differences in active TGF-β3 concentration were found among the sample groups. Moreover, TGF-β pathway activation was significantly lower at baseline compared to controls. Our data corroborate an anti-angiogenic role for TGF-β2 in nAMD. This should be considered from the perspective of a therapy using TGF-β inhibitors

Infectious agents and cancer: A look into EBV pathways involved in the transition from infection to lymphomagenesis

Epidemiological and biological studies have conclusively proved that infectious agents are among the main causes of cancer worldwide. Approximately 18% of all human cancer have been linked to persistent infections from RNA or DNA viruses that include Epstein-Barr virus (EBV), human papilloma virus and Human T-lymphotropic virus type 1. Although each virus has its own specific mechanism for promoting carcinogenesis, the most common outcome for virus-induced reprogramming is genomic instability, including accumulation of mutations, aberrations and DNA damage. The progression to cancer as result of infection is usually a rare event and when it occurs it requires years to decades from the initial infection to tumour development. EBV, classified as class I carcinogen by WHO for its ability of transforming B-cell and functioning as oncogenic factor, is one of the many factors that can be linked to human malignancies. It is estimated that it accounts for more than 200,000 cases of cancer each year and that 1.8% of all cancer deaths are due to EBV. Here, we described several molecular mechanisms underlying the virus-induced carcinogenesis, expecially in Burkitt’s and Plasmablastic lymphoma. We performed RNA-Seq on 20 eBL cases from Uganda and we showed that the mutational and viral landscape of eBL is more complex than previously reported. First, we found the presence of other herpesviridae family members in 8 cases (40%), in particular human herpesvirus 5 and human herpesvirus 8 and confirmed their presence by immunohistochemistry in the adjacent non-neoplastic tissue. Second, we identified a distinct latency program in EBV involving lytic genes in association with TCF3 activity. Third, by comparing the eBL mutational landscape with published data on sporadic Burkitt lymphoma (sBL), we detected lower frequencies of mutations in MYC, ID3, TCF3 and TP53, and a higher frequency of mutation in ARID1A in eBL samples. Recurrent mutations in two genes not previously associated with eBL were identified in 20% of tumors: RHOA and cyclin F (CCNF). We also observed that polyviral samples showed lower numbers of somatic mutations in common altered genes in comparison to sBL specimens, suggesting dual mechanisms of transformation, mutation versus virus driven in sBL and eBL respectively. We also identified a subset of cellular and viral microRNAs differentially expressed between Epstein-Barr-positive and Epstein-Barr-negative Burkitt lymphoma cases. Of these, we characterized the effects of viral BART6-3p on regulation of cellular genes. In particular, we analyzed the IL-6 receptor genes (IL-6Rα and IL-6ST), PTEN and WT1 expression for their possible relevance to Burkitt lymphoma. By means of immunohistochemistry, we observed a down-regulation of the IL-6 receptor and PTEN specifically in Epstein-Barr-positive Burkitt lymphoma cases, which may result in the impairment of key cellular pathways and may contribute to malignant transformation. On the contrary, no differences were observed between Epstein-Barr-positive and Epstein-Barr-negative Burkitt lymphoma cases for WT1 expression. The oncogenic role of EBV was also investigated in Plasmablastic lymphoma. Our analysis revealed a non-canonical latency program with the partial expression of some proteins characterizing latency II and the activation of an abortive lytic cycle. We also performed microRNAs expression profiling through next generation sequencing to investigate the cellular and viral pattern of Plasmastic lymphoma. We identify a subset of viral miRNAs differentially expressed and showed an important role of EBV-miRNAs-Bart-19 in affecting many cellular pathways including lipid metabolism and cell proliferation. Finally, we considered the fact EBV might have contributed to lymphomagenesis in more samples than those remaining EBV positive by exploting a “hit and run” mechanism. We investigated a total of 10 cases and we found that all the samples (n=6) diagnosed as EBV negative by immunohistochemistry and EBER-ISH demonstrated the presence of EBV-microRNAs and EBV genome. This points at the possibility that EBV might have contributed to lymphomagenesis in all our patients, and propose microRNAs detection as the most specific and sensitive tool to recognize EBV vestiges. Collectively, our preliminary results point at an active role for the Epstein-Barr virus in lymphomagenesis and suggest new possible mechanisms used by the virus in determining dysregulation of the host cell physiology. Moreover, our data would have considerable implications for EBV-related diseases control and development of novel EBV-detection strategies

Epstein–Barr Virus Infection in Cancer

EBV was the first human oncogenic virus identified [...

Adicionales de obra y enriquecimiento indebido en el marco del Decreto Legislativo Nº 1017 – Ley de Contrataciones del Estado y su Reglamento

Esta tesis tiene como objetivo brindar una alternativa de solución a la deficiencia legal en la que incurre el Decreto Legislativo N° 1 071 Ley de Contrataciones del Estado, al momento de regular el tema de Adicionales de Obra y su desarrollo dentro del Arbitraje; de tal manera que los conflictos generados a raíz de los contratos celebrados entre los particulares y el Estado encuentran en el arbitraje un medio idóneo para garantizar su solución ágil y rápida, siendo ésta la forma prescrita en dicha norma para la solución de conflictos Consecuentemente si bien la realización del arbitraje al momento de decidir sobre los adicionales de obra se funda en la voluntad de las partes, en el ámbito de las contrataciones públicas, la prohibición de discutir en un proceso arbitral los adicionales de obra; ha dado paso a que los contratistas, en su afán de querer recobrar aquello que invirtieron en prestaciones no contempladas en el Expediente Técnico y que resultaban fundamentales para alcanzar la finalidad del contrato, recurran a la figura del enriquecimiento indebido en el ámbito arbitral, no existiendo unanimidad en el laudo arbitral al momento del surgimiento de este tipo de controversias. Es importante mencionar también que la presente investigación ha sido desarrollada, con un análisis Minucioso y didáctico del tema, para lo cual se ha tomado en cuenta la normatividad vigente, así como también los diversos pronunciamientos de las entidades encargadas de regular sobre contrataciones y los criterios relevantes de la doctrina. Para Finalizar, esperamos que este trabajo sea de gran ayuda y sirva de consulta para el enriquecimiento doctrinario de la matera

Epstein–Barr virus infection in cancer

EBV was the first human oncogenic virus identified. It was discovered in tumour cells isolated from Burkitt’s lymphoma tissue by Sir Anthony Epstein and Dr Yvonne Barr in 1964. Some years after its discovery, EBV was shown to be able to transform normal leukocytes into lymphoblastoid cell lines (LCLs). Since then, EBV has been found to be associated with many malignancies originating from lymphocytes or epithelial cells (Burkitt’s lymphoma, post-transplant and HIV-associated lymphomas, Hodgkin’s lymphoma, T-cell lymphoma, extra-nodal nasal-type natural killer/T-cell lymphoma, nasopharyngeal cancer, and a subset of gastric cancers), contributing to 1.5% of all cancer cases worldwide and approximately 200,000 new cases every year. However, this virus is found in more than 90% of healthy adults worldwide, indicating that EBV infection alone is not enough to cause cancer. The specific geographical distribution of some EBV-associated malignancies (such as Burkitt’s lymphoma in equatorial Africa and nasopharyngeal cancer in East Asia) indicates that the development of an EBV-associated neoplasm requires different environmental and genetic co-factors, of which only some are currently known. In this Special Issue, we present a collection of 26 papers (9 research papers and 17 reviews) covering a range of topics related to EBV infection in cancer patients. These fall into three general areas: (1) EBV-encoded genes; (2) EBV and immune responses; and (3) EBV-associated malignancies and EBV-targeted therapies. In this Special Issue, we aim to further elucidate the role of EBV infection in EBV-driven malignancies by reviewing the literature and reporting new findings addressing some of the unanswered questions in the field of EBV</p