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Background: COVID-19 is characterised by respiratory symptoms, which deteriorate into respiratory failure in a substantial proportion of cases, requiring intensive care in up to a third of patients admitted to hospital. Analysis of the pathological features in the lung tissues of patients who have died with COVID-19 could help us to understand the disease pathogenesis and clinical outcomes.Methods: We systematically analysed lung tissue samples from 38 patients who died from COVID-19 in two hospitals in northern Italy between Feb 29 and March 24, 2020. The most representative areas identified at macroscopic examination were selected, and tissue blocks (median seven, range five to nine) were taken from each lung and fixed in 10% buffered formalin for at least 48 h. Tissues were assessed with use of haematoxylin and eosin staining, immunohistochemical staining for inflammatory infiltrate and cellular components (including staining with antibodies against CD68, CD3, CD45, CD61, TTF1, p40, and Ki-67), and electron microscopy to identify virion localisation.Findings: All cases showed features of the exudative and proliferative phases of diffuse alveolar damage, which included capillary congestion (in all cases), necrosis of pneumocytes (in all cases), hyaline membranes (in 33 cases), interstitial and intra-alveolar oedema (in 37 cases), type 2 pneumocyte hyperplasia (in all cases), squamous metaplasia with atypia (in 21 cases), and platelet-fibrin thrombi (in 33 cases). The inflammatory infiltrate, observed in all cases, was largely composed of macrophages in the alveolar lumina (in 24 cases) and lymphocytes in the interstitium (in 31 cases). Electron microscopy revealed that viral particles were predominantly located in the pneumocytes.Interpretation: The predominant pattern of lung lesions in patients with COVID-19 patients is diffuse alveolar damage, as described in patients infected with severe acute respiratory syndrome and Middle East respiratory syndrome coronaviruses. Hyaline membrane formation and pneumocyte atypical hyperplasia are frequent. Importantly, the presence of platelet-fibrin thrombi in small arterial vessels is consistent with coagulopathy, which appears to be common in patients with COVID-19 and should be one of the main targets of therapy.Funding: None. [ABSTRACT FROM AUTHOR]

The development of materials that allow the sustained release of therapeutic proteins is the key feature for improving their pharmacokinetics, bioavailability, and dose reduction. In this context, hydrogels are attracting interest, but their design to provide a sustained release profile is still a challenge. Usually, a large mass of polymer is required to prolong the release of the therapeutic agent, involving hydrogels with high thicknesses, which limits their use in some applications. Here, the synthesis of thin thermoresponsive and functionalized hydrogels (tHGs) for sustained protein release is reported to tackle this problem. tHGs were obtained by photo-crosslinking of linear thermoresponsive polyurethanes (PU) based on polyethilenglycol and a functional diol (methyldiethanolamine) that contribute to tertiary amine functionality. These biocompatible tHGs conserved the thermosensitive property of PU, exhibiting a reversible volume change between the swollen and the collapsed state, as a function of temperature. tHGs were able to load the model protein ovalbumin homogenously in their matrix, and sustainably release it during 25 days with a tuneable profile, by changing the PU composition. Finally, this proposal, which combined a very thin delivery film with a sustained protein release, could be a good candidate for its application in ocular therapy. [Display omitted] • Thin hydrogels through photo-crosslinking of linear thermoresponsive polyurethanes. • Low thickness plataform with long-time sustained release. • Network mesh size and protein-polyurethane interaction control the sustained release. [ABSTRACT FROM AUTHOR]

Highlights • Little is known on liver histology after hematopoietic stem cell transplantation (HSCT). • We therefore carried out a prospective observational trial of serial liver biopsies in a consecutive cohort of 50 children undergoing allogeneic HSCT. • Isolated biliary ductopenia was the main feature, was diagnosed in 113 of 131 biopsies (93%), and was found to worsen over time. • On multivariate analysis severe ductopenia was strictly associated with previous chemotherapy but not with history of graft-versus-host disease. • We conclude that biliary ductopenia after HSCT may be the result of drug-induced liver disease and should not be treated with addition of immunosuppression. Abstract There are no structured studies on liver histology after hematopoietic stem cell transplantation (HSCT). We aimed to prospectively describe the clinicopathologic features of liver disease in the long term after HSCT in an observational, longitudinal study of liver histology in a consecutive cohort of children undergoing allogeneic HSCT. First liver biopsy was performed in presence of abnormal liver function tests and repeated per protocol thereafter. A previously reported semiquantitative score evaluating inflammation, cholestasis, and ductopenia (bile ducts-to-portal tracts ratio ≤.5) was adopted. Graft-versus-host disease (GVHD) was diagnosed according to standard criteria. We evaluated 131 biopsies taken in 50 HSCTs performed in 47 children (mean age, 9.7 ± 5.2 years). Pre-HSCT chemotherapy was administered in 36 of 50 (72%). GVHD was diagnosed in 17 of 50 (34%). Over time the overall score decreased from a mean of 6 ± 2.7 to 3.25 ±.96 (P <.01), inflammation from 1.22 ± 1.19 to 1 ± 0 (not significant), and cholestasis from 3.9 ± 2.08 to 1.5 ±.58 (P <.01). Ductopenia, found in 113 of 131 biopsies (93%), worsened from.63 ±.35 to.16 ±.14 (P <.01). On multivariate analysis severe ductopenia (ratio ≤.2) was associated with previous chemotherapy (P =.04), in particular with thiotepa, but not with history of GVHD. Vanishing bile duct syndrome after HSCT may be due to drug-induced liver disease. Longer follow-up will reveal whether these patients are prone to late liver-related morbidity and mortality. [ABSTRACT FROM AUTHOR]

Background Identifying the causes of acute liver failure (ALF) and predictors of death or liver transplantation (LTX) is crucial to decide its management. We aimed to describe features and outcome of ALF in Italian children. Methods Retrospective review of cases presenting between 1996–2012. ALF was defined by high transaminases, INR ≥2.0 regardless of hepatic encephalopathy (HE), no evidence of underlying chronic liver disease. Results 55 children (median age 2.6 years, range 0.1–15.1; M/F = 31/24) had ALF due to autoimmune hepatitis (AIH) in 10 (18%), metabolic disorders in 9 (17%), paracetamol overdose in 6 (11%), mushroom poisoning in 3 (5%), viral infection in 1 (2%), indeterminate in 26 (47%); 25/55 recovered with supportive management (45%); 28/55 underwent LTX and 2 died on the waiting list (55%). On multivariate analysis severity of HE grade 3–4 and bilirubin ≥12 mg/dl were independent predictors of death or LTX (p < 0.05). After a median follow up of 4 years (range 2–15.0 years) the overall survival rate was 93%. Conclusion Children with ALF can be managed successfully with combined medical treatment and transplantation, warranting a survival rate similar to children transplanted because of chronic conditions. In our cohort of patients severe HE and high bilirubin on admission were independent predictors of the need of LTX. [ABSTRACT FROM AUTHOR]

Background Characteristics such as gender and lifestyle are not taken in account in colorectal cancer screening and surveillance recommendations. Aims To identify factors associated with advanced neoplasia at initial and surveillance colonoscopy. Methods In this observational study, 750 individuals with positive faecal occult blood test, aged 50–74 years, underwent a first screening colonoscopy in 2007–2009. We collected anthropometric data as well as data on physical activity, smoking and drinking habits, fruit and vegetable consumption and low-dose aspirin use through a questionnaire. Results At initial colonoscopy advanced neoplasia ( n = 399, 53.2%) was positively associated with age, male gender, smoking and alcohol drinking, and inversely associated with physical activity, fruit and vegetables consumption and long-term use of aspirin. These 7 factors were used to calculate a risk score, ranging from 0 (no unfavourable characteristics) to 7 (all unfavourable characteristics present), which was significantly associated with advanced neoplasia (odds ratio 1.55 for one point increase, P < 0.01). Among the 372 adenoma patients who returned for follow-up surveillance colonoscopy, the score remained associated with advanced neoplasia (odds ratio 1.28 for one point increase, P = 0.01). Conclusion Besides age and gender, modifiable factors such as lifestyle and aspirin use were associated with the risk of advanced neoplasia at initial and surveillance colonoscopy. [ABSTRACT FROM AUTHOR]

Poly(ADP)ribosylation inhibitors (PARP i s) are toxic to cancer cells with homologous recombination (HR) deficiency but not to HR-proficient cells in the tumor microenvironment (TME), including tumor-associated macrophages (TAMs). As TAMs can promote or inhibit tumor growth, we set out to examine the effects of PARP inhibition on TAMs in BRCA1-related breast cancer (BC). The PARP i olaparib causes reprogramming of TAMs toward higher cytotoxicity and phagocytosis. A PARP i -related surge in NAD+ increases glycolysis, blunts oxidative phosphorylation, and induces reverse mitochondrial electron transport (RET) with an increase in reactive oxygen species (ROS) and transcriptional reprogramming. This reprogramming occurs in the absence or presence of PARP1 or PARP2 and is partially recapitulated by addition of NAD derivative methyl-nicotinamide (MNA). In vivo and ex vivo , the effect of olaparib on TAMs contributes to the anti-tumor efficacy of the PARP i. In vivo blockade of the "don't-eat-me signal" with CD47 antibodies in combination with olaparib improves outcomes in a BRCA1-related BC model. [Display omitted] • PARP inhibition reprograms metabolism and transcription in macrophages • Accumulation of NAD increases reactive oxygen species via reverse electron transport • High ROS production and phagocytic capacity result in anti-tumor function • The combination of olaparib with CD47 antibodies improves outcomes in a mouse model Wang et al. demonstrate that a PARP inhibitor used to treat breast tumors with homologous recombination (HR) deficiency reprograms the HR-proficient macrophages in the tumor microenvironment toward an anti-tumor phenotype. Blocking the "don't-eat-me" signal on tumor cells with anti-CD47 antibodies enhances the therapeutic efficacy of olaparib in a mouse model. [ABSTRACT FROM AUTHOR]

Background Thymic stromal lymphopoietin (TSLP) is a cytokine with pleiotropic functions in the immune system. It has been associated with allergic reactions in the skin and lungs but also homeostatic tolerogenic responses in the thymus and gut. Objective In human subjects TSLP is present in 2 isoforms, short and long. Here we wanted to investigate the differential expression of the TSLP isoforms and discern their biological implications under homeostatic or inflammatory conditions. Methods We evaluated the expression of TSLPs in tissues from healthy subjects, patients with ulcerative colitis, patients with celiac disease, and patients with atopic dermatitis and on epithelial cells and keratinocytes under steady-state conditions or after stimulation. We then tested the immune activity of TSLP isoforms both in vitro and in vivo . Results We showed that TSLP isoforms are responsible for 2 opposite immune functions. The short isoform is expressed under steady-state conditions and exerts anti-inflammatory activities by affecting the capacity of PBMCs and dendritic cells to produce inflammatory cytokines. Moreover, the short isoform TSLP ameliorates experimental colitis in mice and prevents endotoxin shock. The long isoform of TSLP is proinflammatory and is only expressed during inflammation. The isoforms are differentially regulated by pathogenic bacteria, such as Salmonella species and adhesive-invasive Escherichia coli . Conclusions We have solved the dilemma of TSLP being both homeostatic and inflammatory. The TSLP isoform ratio is altered during several inflammatory disorders, with strong implications in disease treatment and prevention. Indeed, targeting of the long isoform of TSLP at the C-terminal portion, which is common to both isoforms, might lead to unwanted side effects caused by neutralization of the homeostatic short isoform. [ABSTRACT FROM AUTHOR]

Abstract: Carbon Fiber Reinforced Polymer (CFRP) strips externally bonded on a damaged steel beams are effective under monotonic loads. Less information is available on the fatigue behavior. Experimental tests were then performed at the Politecnico di Milano on flexural strengthening of cracked steel beams with CFRP strips of different thickness. The results in term of fatigue crack propagation curves showed that CFRPs bonded around the tip zone reduce the fatigue crack growth and extend the fatigue life. In addition, high strain concentration was recorded in the CFRP strip close to the cracked section. This indicates that the cracked zone is a potential debonding area of the CFRP strips from the steel substrate. [Copyright &y& Elsevier]

Abstract: Carbon Fiber Reinforced Polymer (CFRP) composites have been proven to be effective in extending the fatigue life of cracked steel members. Fatigue tests were executed on cracked steel plates (single edge specimen) reinforced by strips bonded to a single side. Different patch configurations, reinforcement thicknesses and initial damage levels were investigated. CFRP materials bonded around the tip area extend the fatigue life of the damaged steel elements. The stress intensity factor of the reinforced elements was evaluated through FEM. Finally the fatigue crack propagation curves were evaluated by integration of the Paris law and compared to the experimental data. [Copyright &y& Elsevier]

Abstract: Background: During evolution, organisms with renewable tissues have developed mechanisms to prevent tumorigenesis, including cellular senescence and apoptosis. Cellular senescence is characterized by a permanent cell cycle arrest triggered by both endogenous stress and exogenous stress. The p19INK4d, a member of the family of cyclin-dependent kinase inhibitors (INK4), plays an important role on cell cycle regulation and in the cellular DNA damage response. We hypothesize that p19INK4d is a potential factor involved in the onset and/or maintenance of the senescent state. Methods: Senescence was confirmed by measuring the cell cycle arrest and the senescence-associated β-galactosidase activity. Changes in p19INK4d expression and localization during senescence were determined by Western blot and immunofluorescence assays. Chromatin condensation was measured by microccocal nuclease digestion and histone salt extraction. Results: The data presented here show for the first time that p19INK4d expression is up-regulated by different types of senescence. Changes in senescence-associated hallmarks were driven by modulation of p19 expression indicating a direct link between p19INK4d induction and the establishment of cellular senescence. Following a senescence stimulus, p19INK4d translocates to the nucleus and tightly associates with chromatin. Moreover, reduced levels of p19INK4d impair senescence-related global genomic heterochromatinization. Analysis of p19INK4d mRNA and protein levels in tissues from differently aged mice revealed an up-regulation of p19INK4d that correlates with age. Conclusion: We propose that p19INK4d participates in the cellular mechanisms that trigger senescence by contributing to chromatin compaction. General significance: This study provides novel insights into the dynamics process of cellular senescence, a central tumor suppressive mechanism. [Copyright &y& Elsevier]

Abstract: Background: Diagnosis and management of Barrett's oesophagus are controversial. Technical improvements in real-time recognition of intestinal metaplasia and neoplastic foci provide the chance for more effective target biopsies. Confocal laser endomicroscopy allows to analyze living cells during endoscopy. Aims: To assess the diagnostic accuracy, inter- and intra-observer variability of endomicroscopy for detecting in vivo neoplasia (dysplasia and/or early neoplasia) in Barrett's oesophagus. Methods: Prospective pilot study. Patients referred for known Barrett's oesophagus were screened. Endomicroscopy was carried out in a circular fashion, every 1–2cm, on the whole columnar-lined distal oesophagus. Visible lesions, when present, were analyzed first. Targeted biopsies were taken. Confocal images were classified according to confocal Barrett classification. Endomicroscopic and histological findings were compared. Results: Forty-eight out of 50 screened patients underwent endomicroscopy. Visible lesions were observed in 3 patients. In a per-biopsy analysis, Barrett's-oesophagus-associated neoplasia could be predicted with an accuracy of 98.1%. The agreement between endomicroscopic and histological results was substantial (κ =0.76). Conclusions: This study suggests that endomicroscopy can provide in vivo diagnosis of Barrett's oesophagus-associated neoplasia. Because it allows for the study of larger surface areas of the mucosa, endomicroscopy may lead to significant improvements in the in vivo screening and surveillance of Barrett's oesophagus. [Copyright &y& Elsevier]

Protein kinase C-related protein kinases (PRKs) are effectors of the Rho family of small GTPases and play a role in the development of diseases such as prostate cancer and hepatitis C. Here we examined the mechanism underlying the regulation of PRK2 by its N-terminal region. We show that the N-terminal region of PRK2 prevents the interaction with its upstream kinase, the 3-phosphoinositide-dependent kinase 1 (PDK1), which phosphorylates the activation loop of PRK2. We confirm that the N-terminal region directly inhibits the kinase activity of PRK2. However, in contrast to previous models, our data indicate that this inhibition is mediated in trans through an intermolecular PRK2-PRK2 interaction. Our results also suggest that amino acids 487-501, located in the linker region between the N-terminal domains and the catalytic domain, contribute to the PRK2-PRK2 dimer formation. This dimerization is further supported by other N-terminal domains. Additionally, we provide evidence that the region C-terminal to the catalytic domain intramolecularly activates PRK2. Finally, we discovered that the catalytic domain mediates a cross-talk between the inhibitory N-terminal region and the activating C-terminal region. The results presented here describe a novel mechanism of regulation among AGC kinases and offer new insights into potential approaches to pharmacologically regulate PRK2. [ABSTRACT FROM AUTHOR]