Search results for "Invasion"
showing 10 items of 214 documents
Antibiotrophy: Key Function for Antibiotic-Resistant Bacteria to Colonize Soils—Case of Sulfamethazine-Degrading Microbacterium sp. C448
2021
Chronic and repeated exposure of environmental bacterial communities to anthropogenic antibiotics have recently driven some antibiotic-resistant bacteria to acquire catabolic functions, enabling them to use antibiotics as nutritive sources (antibiotrophy). Antibiotrophy might confer a selective advantage facilitating the implantation and dispersion of antibiotrophs in contaminated environments. A microcosm experiment was conducted to test this hypothesis in an agroecosystem context. The sulfonamide-degrading and resistant bacterium Microbacterium sp. C448 was inoculated in four different soil types with and without added sulfamethazine and/or swine manure. After 1 month of incubation, Micro…
Stable isotope analysis reveals trophic segregation between the invasive zebra mussel Dreissena polymorpha and the native duck mussel Anodonta anatin…
2022
AbstractNon-indigenous freshwater bivalves negatively affect invaded ecosystems through different mechanisms, including inter-specific competition for trophic resources. Here, we investigated in Lake Trasimeno (Central Italy) the diet of the invasive Dreissena polymorpha and the native Anodonta anatina. δ15N and δ13C stable isotopes were measured in winter and summer in bivalves, phytoplankton, and sedimentary organic matter (SOM); the relative dietary contributions of the two resources were determined using Bayesian mixing models. To elucidate the different carbon and nitrogen pools characterizing the study site, isotopic analyses were extended to zooplankton and to representatives of the …
Characterization of the biofilm mode of life in the spoilage yeast Brettanomyces bruxellensis
2022
The management of contamination by the spoilage yeast Brettanomyces bruxellensis is a real challenge for the wine industry. The biofilm mode of life, known to increase the resistance of micro-organisms and to allow their persistence in the environment, is a strategy that can be adopted by B. bruxellensis.In this thesis project, microscopic observations revealed the presence of matrix around the cells, an essential element in the definition of a biofilm. The study also revealed that different morphotypes are involved in the structure of the biofilm, in particular filaments forming a network. Chlamydospore-like elements, never described before in B. bruxellensis, were observed within the biof…
In Vivo Observations on Tumor Invasion
1989
Tumor invasion in vivo is a very complex and dynamic process which depends upon a variety of interactions between heterogeneous tumor cell populations and the different cellular and extracellular components of the host tissue. This situation cannot be reproduced even in the most sophisticated in vitro system. On the other hand, there is at present no method available for a direct and dynamic observation of tumor invasion deep in the nontransparent living tissue, so that all evidence has to be derived from indirect observations made on the basis of static morphology. But all these limitations do not deny the potential value of in vivo investigations in following the natural course of tumor i…
Neuroinvasion and Viral Reservoir in COVID-19.
2020
The new coronavirus disease 2019 (COVID-19) has a remarkably high transmissibility potential and sometimes invades the central nervous system (CNS). The study of the involvement of the nervous system in the pathogenesis of the disease is especially interesting. Currently, there are only three main theories about it: direct neuroinvasion; blood-brain barrier (BBB) crossing and nicotinic hypothesis. Because of the rapid expansion of a virus that until now was unknown, it is necessary to know the mechanisms by which severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) generates the disease. The study of the involvement of the nervous system in the pathogenesis of the disease …
Plexin-B1 and Semaphorin 4D Cooperate to Promote Perineural Invasion in a RhoA/ROK-Dependent Manner
2012
Perineural invasion (PNI) is a tropism of tumor cells for nerve bundles located in the surrounding stroma. It is a pathological feature observed in certain tumors, referred to as neurotropic malignancies, that severely limits the ability to establish local control of disease and results in pain, recurrent growth, and distant metastases. Despite the importance of PNI as a prognostic indicator, its biological mechanisms are poorly understood. The semaphorins and their receptors, the plexins, compose a family of proteins originally shown to be important in nerve cell adhesion, axon migration, and proper central nervous system development. Emerging evidence has demonstrated that these factors a…
Hepatectomy Versus Sorafenib in Advanced Non-Metastatic Hepatocellular Carcinoma: A Real-Life Multicentric Weighted Comparison
2022
Objective: The aim of the study was to compare SURG vs SOR regarding the OS and progression-free survival (PFS) in a real-world clinical scenario. Background data: The treatment for advanced nonmetastatic HCC belonging to the Barcelona Clinic Liver Cancer stage C (BCLC C) is still controversial. Methods: BCLC C patients without extrahepatic spread and tumoral invasion of the main portal trunk were considered. Surgical patients were obtained from the HE.RC.O.LE.S. Register, whereas sorafenib patients were obtained from the ITA.LI.CA register The inverse probability weighting (IPW) method was adopted to balance the confounders between the 2 groups. Results: Between 2008 and 2019, 478 patients…
Breast cancer subtypes can be determinant in the decision making process to avoid surgical axillary staging: A retrospective cohort study.
2015
Abstract Introduction The need for performing axillary lymph-node dissection in early breast cancer when the sentinel lymph node (SLN) is positive has been questioned in recent years. The purpose of this study was to identify a low-risk subgroup of early breast cancer patients in whom surgical axillary staging could be avoided, and to assess the probability of having a positive lymph-node (LN). Methods We evaluated the cohort of 612 consecutive women affected by early breast cancer. We considered age, tumor size, histological grade, vascular invasion, lymphatic invasion and cancer subtype (Luminal A, Luminal B HER-2+, Luminal B HER-2−, HER-2+, and Triple Negative) as variables for univariat…
The Assessment of Risk Factors for Long-term Survival Outcome in ypN0 Patients With Rectal Cancer After Neoadjuvant Therapy and Radical Anterior Rese…
2021
Abstract Background The main negative prognostic factors in patients with rectal cancer after radical treatment include regional lymph node involvement, lymphovascular invasion, and perineural invasion. However, some patients still develop cancer recurrence despite the absence of the above risk factors. The aim of the study was to assess clinicopathological factors influencing long-term oncologic outcomes in ypN0M0 rectal cancer patients after neoadjuvant therapy and radical anterior resection. Methods A retrospective survival analysis was performed on a group of 195 patients. We assessed clinicopathological factors which included tumor regression grade, number of lymph nodes in the specime…
Detection of postoperative plasma circulating tumour DNA and lack of CDX2 expression as markers of recurrence in patients with localised colon cancer
2020
BACKGROUND: Colon cancer (CC) is a heterogeneous disease. Novel prognostic factors beyond pathological staging are required to accurately identify patients at higher risk of relapse. Integrating these new biological factors, such as plasma circulating tumour DNA (ctDNA), CDX2 staining, inflammation-associated cytokines and transcriptomic consensus molecular subtypes (CMS) classification, into a multimodal approach may improve our accuracy in determining risk of recurrence.; METHODS: One hundred and fifty patients consecutively diagnosed with localised CC were prospectively enrolled in our study. ctDNA was tracked to detect minimal residual disease by droplet digital PCR. CDX2 expression was…