Provenance of Pleistocene sediments in the ANDRILL AND-1B drillcore: Clay and heavy mineral data

The cryosphere in the McMurdo Sound region has undergone significant modifications during the last 1 Ma. Consequently, the sedimentary sequences underlying the modern McMurdo Ice-Shelf provide geological data to reconstruct variations in transport and depositional mechanisms of terrigenous material due to variations in ice sheet extension, grounding line position and main icestream flow directions during glacial and interglacial periods. The present study aims to investigate the clay and heavy mineral assemblages of the late Pleistocene subglacial and glaciomarine sediments recovered during the ANDRILL-McMurdo Ice Shelf Project in Windless Bight (South of Ross Island). The analyses show that the sediments are a mix of detritus from the McMurdo Volcanic Group (MVG) and the Transantarctic Mountains (TAM) from the south and west. MVG-derived minerals prevail with respect to TAM-derived minerals. The down-core mineralogical variations are determined by changes in the source rocks and the sedimentary processes. Sediments at the drill site are nourished by ice coming from the South which delivered rocks from the McMurdo Volcanic region; the enrichment of a TAM component in massive diamictites testifies that the ice sheet collected debris from the Transantarctic Mountains. When open marine conditions prevailed, only sediments from a local source (i.e. McMurdo volcanics) were deposited

Microevolution of Helicobacter pylori during prolonged infection of single hosts and within families

Our understanding of basic evolutionary processes in bacteria is still very limited. For example, multiple recent dating estimates are based on a universal inter-species molecular clock rate, but that rate was calibrated using estimates of geological dates that are no longer accepted. We therefore estimated the short-term rates of mutation and recombination in Helicobacter pylori by sequencing an average of 39,300 bp in 78 gene fragments from 97 isolates. These isolates included 34 pairs of sequential samples, which were sampled at intervals of 0.25 to 10.2 years. They also included single isolates from 29 individuals (average age: 45 years) from 10 families. The accumulation of sequence diversity increased with time of separation in a clock-like manner in the sequential isolates. We used Approximate Bayesian Computation to estimate the rates of mutation, recombination, mean length of recombination tracts, and average diversity in those tracts. The estimates indicate that the short-term mutation rate is 1.4×10−6 (serial isolates) to 4.5×10−6 (family isolates) per nucleotide per year and that three times as many substitutions are introduced by recombination as by mutation. The long-term mutation rate over millennia is 5–17-fold lower, partly due to the removal of non-synonymous mutations due to purifying selection. Comparisons with the recent literature show that short-term mutation rates vary dramatically in different bacterial species and can span a range of several orders of magnitude

Abdominal drainage after elective colorectal surgery: propensity score-matched retrospective analysis of an Italian cohort

background: In italy, surgeons continue to drain the abdominal cavity in more than 50 per cent of patients after colorectal resection. the aim of this study was to evaluate the impact of abdominal drain placement on early adverse events in patients undergoing elective colorectal surgery. methods: a database was retrospectively analysed through a 1:1 propensity score-matching model including 21 covariates. the primary endpoint was the postoperative duration of stay, and the secondary endpoints were surgical site infections, infectious morbidity rate defined as surgical site infections plus pulmonary infections plus urinary infections, anastomotic leakage, overall morbidity rate, major morbidity rate, reoperation and mortality rates. the results of multiple logistic regression analyses were presented as odds ratios (OR) and 95 per cent c.i. results: a total of 6157 patients were analysed to produce two well-balanced groups of 1802 patients: group (A), no abdominal drain(s) and group (B), abdominal drain(s). group a versus group B showed a significantly lower risk of postoperative duration of stay >6 days (OR 0.60; 95 per cent c.i. 0.51-0.70; P < 0.001). a mean postoperative duration of stay difference of 0.86 days was detected between groups. no difference was recorded between the two groups for all the other endpoints. conclusion: this study confirms that placement of abdominal drain(s) after elective colorectal surgery is associated with a non-clinically significant longer (0.86 days) postoperative duration of stay but has no impact on any other secondary outcomes, confirming that abdominal drains should not be used routinely in colorectal surgery

Antarctic ice sheet sensitivity to atmospheric CO2 variations in the early to mid-Miocene

Geological records from the Antarctic margin offer direct evidence of environmental variability at high southern latitudes and provide insight regarding ice sheet sensitivity to past climate change. The early to mid-Miocene (23-14 Mya) is a compelling interval to study as global temperatures and atmospheric CO2 concentrations were similar to those projected for coming centuries. Importantly, this time interval includes the Miocene Climatic Optimum, a period of global warmth during which average surface temperatures were 3-4 °C higher than today. Miocene sediments in the ANDRILL-2A drill core from the Western Ross Sea, Antarctica, indicate that the Antarctic ice sheet (AIS) was highly variable through this key time interval. A multiproxy dataset derived from the core identifies four distinct environmental motifs based on changes in sedimentary facies, fossil assemblages, geochemistry, and paleotemperature. Four major disconformities in the drill core coincide with regional seismic discontinuities and reflect transient expansion of grounded ice across the Ross Sea. They correlate with major positive shifts in benthic oxygen isotope records and generally coincide with intervals when atmospheric CO2 concentrations were at or below preindustrial levels (∼280 ppm). Five intervals reflect ice sheet minima and air temperatures warm enough for substantial ice mass loss during episodes of high (∼500 ppm) atmospheric CO2. These new drill core data and associated ice sheet modeling experiments indicate that polar climate and the AIS were highly sensitive to relatively small changes in atmospheric CO2 during the early to mid-Miocene

Extracellular Matrix Regulation of Breast Cancer Immune Microenvironment

The pathological grade well defines tumor aggressiveness and, indeed, high-grade breast cancer (HGBC), regardless of molecular findings, is characterized by rapid clinical course and very poor prognosis despite standard chemotherapy regimens and specific-targeted agents. Both the cellular and the extracellular compartments of the TME can contribute to the evolution of BC by powerful immune escape and immune suppression processes. In this context structural and extracellular components of the TME, namely the extracellular matrix (ECM), has been shown to contribute to many aspects of tumor progression, exerting important regulatory functions on tumor cells. The relevance of the ECM in cancer progression is strengthened by study showing that the ECM composition is a prognostic factor able to identify patients subgroups endowed with a different clinical outcome according to the distinct enrichment in ECM genes leading to four specific ECM signatures (ECM 1-4). Among the different ECM-related signatures, only the ECM3 signature, that characterize about 35 % of HGBC, identifies aggressive tumors with epithelial mesenchymal transition (EMT) features, poor prognosis, T-cell exclusion and increased MDSCs. Data obtained in mouse models over-expressing SPARC, one key gene of the ECM3, in BC cells suggested that the ECM impact on immune infiltration and that the ECM3 is involved in building an immune suppressive environment. We evaluated whether the immune suppressive features of ECM3 tumors can be sensed in the peripheral blood (PB) of HGBC patients. To this aim, we collected 70 consecutive HGBC patients that included 22 ECM3+ and 30 ECM3- and performed multiparametric flow cytometry analysis to define different immune cell populations. This PhD thesis highlights that the influence of ECM3 signature on immune cells is relevant as it is able to modify the composition of the peripheral blood of ECM3+ patients in favor of an increase in a subset of regulatory T cells (Treg), defined as PD-1neg Treg cells. Notably, we identified PD-1neg Treg being associated to ECM3 patients and provided the mechanisms through which SPARC directly influence the expression of PD-1 on Treg and therefore directly impacting on their suppressive activity. This population together with the increased recruitment in CD33+ suppressive myeloid cells might account for the T-cell excluded microenvironment of ECM3 tumors. Furthermore, analyzing SPARC expression in ECM3 tumours along with CD33+ recruitment, we provided evidences that SPARC is expressed by MDSCs. Back to mouse model, using Sparc-deficient mice, we demonstrated that SPARC is a new MDSCs marker licensing suppressive activities in these cells. Considering the peculiar immune suppressive environment of ECM3 tumors, we evaluated whether zoledronic acid (ZA) could be adopted as a strategy to revert the immunosuppression, particularly acting on MDSCs. We observed, in a few BC available patients, a reduction of the frequency of MDSCs and we showed that FACS-sorted CD33+ cells had decreased expression of PD-L1 and STAT3 after the administration of ZA. Data suggest that the PB is a mirror of ECM3+ tumors and PD-1neg Treg could be and effective target in ECM3+ patients. Therefore, novel therapeutic strategies are an urgent clinical challenge to be addressed in these HGBC patients

SVILUPPO DI UN MODELLO PRECLINICO DI LEUCEMIA PROMIELOCITICA UMANA IN TOPI NSG: CARATTERIZZAZIONE IMMUNOFENOTIPICA, MOLECOLARE E CITOGENETICA

La leucemia promielocitica acuta (APL) è un sottotipo distinto di leucemia mieloide acuta (AML) classificata come variante M3, secondo la classificazione FAB. La APL è caratterizzata dalla presenza della traslocazione reciproca bilanciata tra i cromosomi 15 e 17, t(15;17)(q22;q21). Questa traslocazione dà luogo alla formazione di una proteina anomala di fusione chiamata PML/RARalfa che coinvolge il gene promielocitico (PML) e il gene che codifica per il recettore alfa dell’acido retinoico (RARalfa) presenti rispettivamente sul cromosoma 15 e 17. L’espressione della proteina determina un blocco maturativo delle cellule della linea mieloide che si arrestano allo stadio di promielocita, provocando un accumulo a livello midollare delle medesime. Le cellule leucemiche, per la presenza di questa alterazione, sono sensibili all’effetto differenziante dell’acido retinoico: tale sostanza, data a dosi farmacologiche, induce maturazione cellulare e differenziazione. La scoperta della sensibilità di questa forma di leucemia all’acido retinoico e lo sviluppo di schemi di trattamento che prevedono l’associazione dell’acido retinoico alla chemioterapia convenzionale, ha modificato drammaticamente la prognosi di questa malattia, che era fino a poco tempo fa considerata a prognosi infausta. La terapia convenzionale che prevede associazione di chemioterapici e acido retinoico, però, benché possa portare ad alte percentuali di guarigione, si associa a una tossicità importante che se non trattata può risultare mortale. Lo scopo di questo lavoro di tesi è quello di sviluppare un modello preclinico di APL che possa permettere lo studio di nuovi farmaci e quindi consentire nuovi approcci terapeutici. Cellule primarie provenienti da sangue periferico di un paziente affetto da APL vengono inoculate in topi NOD-SCID IL2-Rγ –null; la progressione della malattia viene monitorata valutando la presenza di cellule CD45+ umane nel sangue periferico del topo ricevente attraverso un prelievo caudale di sangue effettuato ogni 25-30 giorni dopo l’inoculo e processato mediante metodiche di citofluorimetria a flusso. Il sacrificio degli animali avviene nel momento in cui i medesimi mostrano segni visibili di aggravamento della malattia confermata dalle informazioni che provengono dall’analisi citofluorimetriche sul sangue periferico (l’attecchimento fino ad ora osservato ammonta a circa l’80%). Dopo il sacrificio cellule di sangue periferico, midollo osseo e milza vengono isolate per l’esecuzione di analisi effettuate con diverse tecniche. Viene eseguita l’analisi morfologica facendo uno striscio di sangue periferico e colorando i vetrini con il metodo May Grünwald – Giemsa per evidenziare la presenza di blasti mieloidi. La traslocazione t(15;17) viene individuata grazie all’analisi citogenetica mentre l’analisi immunofenotipica ci permette di identificare la popolazione leucemica in base alla presenza sulla superficie delle cellule di antigeni specifici per il clone promielocitico (CD34-, CD66b+, CD13+,CD33+, CD11b-, CD16b-) e infine analisi molecolare per valutare l’espressione del gene PML/RAR alfa nelle tre forme (bcr1, bcr2, bcr3). Questo tipo di approccio preclinico che consente lo sviluppo di un nuovo modello di APL potrà apportare nuove informazioni riguardo alla evoluzione di questo tipo di patologia in un modello murino derivato da cellule primarie presentante caratteristiche più specifiche rispetto a quelli precedentemente ottenuti utilizzando cellule provenienti da linee cellulari immortalizzate

Major and trace (including REEs) element stratigraphy in the first 90 m (around 1 Myr) of ANDRILL AND-1B drillcore.

An integrated system Inductively Coupled Plasma - Sector Field Mass Spectrometry (ICP-SFMS) and Inductively Coupled Plasma – Atomic Emission Spectrophotometry (ICP – AES) has been applied to quantify 39 major and trace elements (including Rare Earths Elements -REE) in Antarctic glaciomarine sediments collected in the framework of ANDRILL. This project aims to study the role of the Antarctic Continent within the global climatic system, by the recovery and analysis of two deep sediment cores (AND-1B, MIS and AND-2A, SMS), drilled close to the margin of the Ross Ice Shelf. The main goals of ANDRILL were to obtain a stratigraphic record that documents key steps in Antarctica’s Cenozoic climatic and glacial history, and in the tectonic evolution of the Transantarctic Mountains and the West Antarctic rift System. In particular, the study of the geochemical composition of sediments along the two ANDRILL cores can provide information about the possible source of terrigenous material deposited over the drilling site (Harwood et al., 2006). Preliminary results with a spatial resolution of about 1 m for the geochemical composition of the interval 24.66- 85.24 m of depth of marine sediments from AND-1B core covering about the last 1 Ma, are here shown. The concentration ratio of each measured element with respect to Al concentration, used as terrigenous reference, was calculated in order to remove the possible effect on elemental concentrations of differences in average sediment grain-size along the core and possible dilution effects and point out specified metal enrichments. The presented data and depth profiles (e.g. Fe/Al, Mn/Al, Co/Al, Cr/Al, Eu/Al and Europium anomaly) relative to sediments deposited during the last Ma at the MIS site, show an evident discontinuity from samples collected above and below 58.4 m of depth, corresponding to about 0.45 Ma BP, following the latest AND-1B dating model (85.24 m of depth corresponding to about 0.988 Ma; the chronological datum of the sediments is developed from 40Ar/39Ar ages volcanic deposits, Naish et al. 2009). This difference of geochemical composition suggests different rock sources for the material deposited before and after about 0.45 Ma BP. In particular the geochemical composition of the upper sediments is similar to the one of McMurdo Volcanic Group (MVG) whereas the lower sediments are close to the compositions of samples collected in the Transantarctic Mountain (TAM). Such a different composition could be linked to the climatic discontinuity known as Mid-Brunhes Event (MBE), dated 430 Kyr BP, which marks the boundary between two different global climatic conditions, with the youngest part characterized by a larger temperature gap between short and warm interglacials and long and cold glacials, with respect to the oldest part

Impact of Immune Cell Heterogeneity on HER2+ Breast Cancer Prognosis and Response to Therapy

Breast cancer is a heterogeneous disease with a high degree of diversity among and within tumors, and in relation to its different tumor microenvironment. Compared to other oncotypes, such as melanoma or lung cancer, breast cancer is considered a “cold” tumor, characterized by low T lymphocyte infiltration and low tumor mutational burden. However, more recent evidence argues against this idea and indicates that, at least for specific molecular breast cancer subtypes, the immune infiltrate may be clinically relevant and heterogeneous, with significant variations in its stromal cell/protein composition across patients and tumor stages. High numbers of tumor-infiltrating T cells are most frequent in HER2-positive and basal-like molecular subtypes and are generally associated with a good prognosis and response to therapies. However, effector immune infiltrates show protective immunity in some cancers but not in others. This could depend on one or more immunosuppressive mechanisms acting alone or in concert. Some of them might include, in addition to immune cells, other tumor microenvironment determinants such as the extracellular matrix composition and stiffness as well as stromal cells, like fibroblasts and adipocytes, that may prevent cytotoxic T cells from infiltrating the tumor microenvironment or may inactivate their antitumor functions. This review will summarize the state of the different immune tumor microenvironment determinants affecting HER2+ breast tumor progression, their response to treatment, and how they are modified by different therapeutic approaches. Potential targets within the immune tumor microenvironment will also be discussed

A falta que a cidade faz | The lack of the city

Este artigo apresenta os resultados e análises de uma pesquisa que busca compreender como, em tempos de isolamento social, a população está se relacionando com o espaço urbano das cidades onde residem. A pesquisa visa compreender de quais espaços urbanos as pessoas mais sentem falta nesse momento de pandemia e qual a sua interação com os espaços que ainda podem ser utilizados durante esse período, investigando a nova relação criada entre a população, espaço de moradia e o espaço urbano à sua volta. A pesquisa teve como público alvo principal a comunidade acadêmica da Universidade Federal de Uberlândia e, para obter os dados necessários para a análise, um questionário online e anônimo foi aplicado através da plataforma Google Forms e as respostas foram usadas para realizar uma sistematização de dados e criar hipóteses e conclusões do estudo. Buscou-se compreender quais os impactos que a pandemia trouxe para a comunidade em relação aos espaços urbanos, além de contribuir com estudos acadêmicos futuros, sendo este um gerador de informação e conhecimento que pode ser utilizado posteriormente para outras análises e reflexões