392 research outputs found
Post-Depositional Biodegradation Processes of Pollutants on Glacier Surfaces
Glaciers are important fresh-water reservoirs for our planet. Although they are often
located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants
can undergo long-range atmospheric transport and be deposited on glacier surface, where they
can be stored for long periods of time, and then be released into the down-valley ecosystems.
Understanding the dynamics of these pollutants in glaciers is therefore important for assessing their
environmental fate. To this aim, it is important to study cryoconite holes, small ponds filled with
water and with a layer of sediment, the cryoconite, at the bottom, which occur on the surface of
most glaciers. Indeed, these environments are hotspots of biodiversity on glacier surface as they host
metabolically active bacterial communities that include generalist taxa able to degrade pollutants.
In this work, we aim to review the studies that have already investigated pollutant (e.g., chlorpyrifos
and polychlorinated-biphenyls (PCBs)) degradation in cryoconite holes and other supraglacial
environmental matrices. These studies have revealed that bacteria play a significant role in pollutant
degradation in these habitats and can be positively selected in contaminated environments. We will
also provide indication for future research in this field
Poorly differentiated clusters (PDC) in colorectal cancer: Does their localization in tumor matter?
Poorly differentiated clusters (PDC) are aggregates of at least five neoplastic cells lacking evidence of glandular differentiation. By definition, they can be present at the invasive front (peripheral PDC or pPDC) and within the tumor stroma (central PDC or cPDC). In colorectal cancer (CRC), PDC are considered adverse prognosticators and seem to reflect epithelial mesenchymal transition (EMT). In this study, we have investigated the immuno-expression of two EMT-related proteins, E-cadherin and β-catenin, in PDC of primary CRCs and matched liver metastases. pPDC always showed nuclear β-catenin staining and diffusely reduced/absence of E-cadherin expression as opposed cPDC which showed nuclear β-catenin immunoreactivity and E-cadherin expression in about 50% of cases. In addition, the pattern of β-catenin and E-cadherin expression differed between PDC and the main tumor, and between primary CRC and liver metastasis (LM), in a percentage of cases. A discordant pattern of β-catenin and E-cadherin expression between pPDC and cPDC, between main tumor and cPDC, and between primary CRC and LM, confirms that EMT is a dynamic and reversible process in CRC. On the overall, this suggests that pPDC and cPDC are biologically different. We may advocate that PDC develop at the tumor center (cPDC) and then some of them migrate towards the tumor periphery while progressively completing EMT process (pPDC). Based on these results, PDC presence and counting may have different prognostic relevance if the assessment is done at the invasive front of the tumor or in the intratumor stroma
Endovascular balloon assistance during hip disarticulation
Objective Limb disarticulation has been widely performed since the 18th century, especially in war surgery. Actually is infrequently done in orthopaedic and vascular surgery, and it is associated with a high mortality rate because of frequent comorbidities. Disarticulation usually is reserved for patients with malignant tumours or gangrene from severe artherosclerosis. During disarticulation, hemodynamic stability can be altered by hemorrhagic events in the femoral or humeral arteries. We propose an endovascular technique for proximal control of the artery to reduce blood loss during disarticulation. Our experience today is limited at hip disarticulation. Material and methods The vascular access was percutaneous at the common femoral artery of the healthy limb. A 6 French (Fr) introducer sheath was placed using the Seldinger technique. Under fluoroscopic control, with a portable vascular C-arm capable of digitally subtracter angiogram and roadmap angiography, a 0.035 inch hydrophilic guide wire was crossed aver into the opposite side iliac artery through a 5F contra angiographic catheter placed at the aortic bifurcation. After a diagnostic angiography the guide wire was replaced with an Amplatz 0.0035 inch, 260 cm long, super stiff guide wire. Then, a 7 9 20 mm Ultra-thinTM SDS balloon catheter was placed in the external iliac artery and systemic heparinization with 2500 UI was performed. The balloon catheter was inflated and femoral pulsation ceased immediately. After proximal, endovascular occlusion, hip disarticulation was accomplished without any hemorrhagic complication. At the end of procedure, the balloon was deflated and removed. Hemostasis of the surgical field completed the procedure. The femoral access in the healthy common femoral artery was controlled with a 6 Fr Angio-seal percutaneous hemostatic system. Results and discussion In hip disarticulation, hemostatic tourniquets cannot be used of the location of the operating field. Therefore, control of bleeding is a major issue in this procedure. Various techniques have been proposed, femoral vessels and nerves were attached before the disarticulation. The use of semi-compliant balloon catheters for endovascular occlusion avoids injury to the endothelium of the vessel wall during balloon inflation. However preoperative assessment, with color-duplex scanning and plain abdominal radiographs, is mandatory; coexisting atherosclerosis often is present especially in elderly patients, and severe wall calcification can lead to vessel rupture and retroperitoneal hematoma, or even balloon catheter rupture. Moreover, color-duplex scanning and radiographs will help in choosing the landing-zone for balloon inflation. Conclusions Endovascular balloon assistance is a simple, safe and effective technique in preventing major arterial bleeding during amputation or disarticulation and can be routinely used
Macroeconomia dos estados e matriz interestadual de insumo-produto
This paper presents the methodology and the results ofthe estimation of a system of state accounts for Brazil. Using the available information on GDP, government revenues and expenditures, international and interstate trade for the states, estimates for consumption and private investment were produced. The system was calibrated for the year 1996. Given the state accounts and the national input-output table, an eight-sector interstate input-output table was prepared
Monitoring alpine glaciers from close-range to satellite sensors
In this paper the use of different types of remote-sensing techniques for monitoring topographic changes of Alpine glaciers is presented and discussed. Close range photogrammetry based on Structure-from-Motion approach is adopted to process images recorded from ground-based and drone-based stations in order to output dense point clouds. These are then directly compared to detect local changes by mean of M3C2 algorithm, while digital elevation models are interpolated to find global ice thinning and retreat. Medium-resolution satellite imagery can be exploited to monitor the glacier evolution at lower resolution but including the development and collapse of large crevasses. A case study concerning the Forni Glacier in the Raethian Alps (Italy) is presented to demonstrate the feasibility of the proposed approach by adopting data sets collected from 2016 to 2018
Hematopoietic Stem Cell (HSC)-Independent Progenitors Are Susceptible to Mll-Af9-Induced Leukemic Transformation.
Infant acute myeloid leukemia (AML) is a heterogeneous disease, genetically distinct from its adult counterpart. Chromosomal translocations involving the KMT2A gene (MLL) are especially common in affected infants of less than 1 year of age, and are associated with a dismal prognosis. While these rearrangements are likely to arise in utero, the cell of origin has not been conclusively identified. This knowledge could lead to a better understanding of the biology of the disease and support the identification of new therapeutic vulnerabilities. Over the last few years, important progress in understanding the dynamics of fetal hematopoiesis has been made. Several reports have highlighted how hematopoietic stem cells (HSC) provide little contribution to fetal hematopoiesis, which is instead largely sustained by HSC-independent progenitors. Here, we used conditional Cre-Lox transgenic mouse models to engineer the Mll-Af9 translocation in defined subsets of embryonic hematopoietic progenitors. We show that embryonic hematopoiesis is generally permissive for Mll-Af9-induced leukemic transformation. Surprisingly, the selective introduction of Mll-Af9 in HSC-independent progenitors generated a transplantable myeloid leukemia, whereas it did not when introduced in embryonic HSC-derived cells. Ex vivo engineering of the Mll-Af9 rearrangement in HSC-independent progenitors using a CRISPR/Cas9-based approach resulted in the activation of an aberrant myeloid-biased self-renewal program. Overall, our results demonstrate that HSC-independent hematopoietic progenitors represent a permissive environment for Mll-Af9-induced leukemic transformation, and can likely act as cells of origin of infant AML
Ex vivo fluorescence confocal microscopy: prostatic and periprostatic tissues atlas and evaluation of the learning curve
Ex vivo fluorescence confocal microscopy (FCM) is an optical technology that provides fast H&E-like images of freshly excised tissues, and it has been mainly used for “real-time” pathological examination of dermatological malignancies. It has also shown to be a promising tool for fast pathological examination of prostatic tissues. We aim to create an atlas for FCM images of prostatic and periprostatic tissues to facilitate the interpretation of these images. Furthermore, we aimed to evaluate the learning curve of images interpretation of this new technology. Eighty fresh and unprepared biopsies obtained from radical prostatectomy specimens were evaluated using the FCM VivaScope® 2500 M-G4 (Mavig GmbH, Munich, Germany; Caliber I.D.; Rochester NY, USA) by two pathologists. Images of FCM with the corresponding H&E are illustrated to create the atlas. Furthermore, the two pathologists were asked to re-evaluate the 80 specimens after 90 days interval in order to assess the learning curve of images’ interpretation of FCM. FCM was able to differentiate between different types of prostatic and periprostatic tissues including benign prostatic glands, benign prostatic hyperplasia, high-grade intraepithelial neoplasm, and prostatic adenocarcinoma. As regards the learning curve, FCM demonstrated a short learning curve. We created an atlas that can serve as the base for urologists and pathologists for learning and interpreting FCM images of prostatic and periprostatic tissues. Furthermore, FCM images is easily interpretable; however, further studies are required to explore the potential applications of this new technology in prostate cancer diagnosis and management
Monitoring cfDNA in plasma and in other liquid biopsies of advanced EGFR mutated NSCLC patients: A pilot study and a review of the literature
In order to study alternatives at the tissue biopsy to study EGFR status in NSCLC patients, we evaluated three different liquid biopsy platforms (plasma, urine and exhaled breath condensate, EBC). We also reviewed the literature of the cfDNA biological sources other than plasma and compared our results with it about the sensitivity to EGFR mutation determination. Twenty-two EGFR T790M-mutated NSCLC patients in progression to first-line treatment were enrolled and candidate to osimertinib. Plasma, urine and EBC samples were collected at baseline and every two months until progression. Molecular analysis of cfDNA was performed by ddPCR and compared to tissue results. At progression NGS analysis was performed. The EGFR activating mutation detection reached a sensitivity of 58 and 11% and for the T790M mutation of 45 and 10%, in plasma and urine samples, respectively. Any DNA content was recovered from EBC samples. Considering the plasma monitoring study, the worst survival was associated with positive shedding status; both plasma and urine molecular progression anticipated the radiological worsening. Our results confirmed the role of plasma liquid biopsy in testing EGFR mutational status, but unfortunately, did not evidence any improvement from the combination with alternative sources, as urine and EBC
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