349 research outputs found

    Glyphosate resistance by engineering the flavoenzyme glycine oxidase.

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    Glycine oxidase from Bacillus subtilis is a homotetrameric flavoprotein of great potential biotechnological use because it catalyzes the oxidative deamination of various amines and D-isomer of amino acids to yield the corresponding \u3b1-keto acids, ammonia/amine, and hydrogen peroxide. Glyphosate (N-phosphonomethylglycine), a broad spectrum herbicide, is an interesting synthetic amino acid: this compound inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, which is essential for the biosynthesis of aromatic amino acids in plants and certain bacteria. In recent years, transgenic crops resistant to glyphosate were mainly generated by overproducing the plant enzyme or by introducing a 5-enolpyruvylshikimate-3-phosphate synthase insensitive to this herbicide. In this work, we propose that the enzymatic oxidation of glyphosate could be an effective alternative to this important biotechnological process. To reach this goal, we used a rational design approach (together with site saturation mutagenesis) to generate a glycine oxidase variant more active on glyphosate than on the physiological substrate glycine. The glycine oxidase containing three point mutations (G51S/A54R/H244A) reaches an up to a 210-fold increase in catalytic efficiency and a 15,000-fold increase in the specificity constant (the kcat/Km ratio between glyphosate and glycine) as compared with wild-type glycine oxidase. The inspection of its three-dimensional structure shows that the \u3b12-\u3b13 loop (comprising residues 50-60 and containing two of the mutated residues) assumes a novel conformation and that the newly introduced residue Arg54 could be the key residue in stabilizing glyphosate binding and destabilizing glycine positioning in the binding site, thus increasing efficiency on the herbicide

    Evaluation on prognostic efficacy of lymph nodes ratio (LNR) and log odds of positive lymph nodes (LODDS) in complicated colon cancer: The first study in emergency surgery

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    Background: Lymph node involvement is one of the most important prognostic factors in colon cancer. Twelve is considered the minimum number of lymph nodes necessary to retain reliable tumour staging, but several factors can potentially influence the lymph node harvesting. Emergent surgery for complicated colon cancer (perforation, occlusion, bleeding) could represent an obstacle to reach the benchmark of 12 nodes with an accurate lymphadenectomy. So, an efficient classification system of lymphatic involvement is crucial to define the prognosis, the indication to adjuvant therapy and the follow-up. This is the first study with the aim to evaluate the efficacy of lymph nodes ratio (LNR) and log odds of positive lymph nodes (LODDS) in the prognostic assessment of patients who undergo to urgent surgery for complicated colonic cancer. Methods: This is a retrospective study carried out on patients who underwent urgent colonic resection for complicated cancer (occlusion, perforation, bleeding, sepsis). We collected clinical, pathological and follow-up data of 320 patients. Two hundred two patients met the inclusion criteria and were distributed into three groups according to parameter N of TNM, LNR and LODDS. Survival analysis was performed by Kaplan-Meier curves, investigating both overall survival (OS) and disease-free survival (DFS). Results: The median number of harvested lymph nodes was 17. In 78.71% (n = 159) of cases, at least 12 lymph nodes were examined. Regarding OS, significant differences from survival curves emerged for ASA score, surgical indication, tumour grading, T parameter, tumour stage, N parameter, LNR and LODDS. In multivariate analysis, only LODDS was found to be an independent prognostic factor. Concerning DFS, we found significant differences between survival curves of sex, surgical indication, T parameter, tumour stage, N parameter, LNR and LODDS, but none of these confirmed its prognostic power in multivariate analysis. Conclusions: We found that N, LNR and LODDS are all related to 5-year OS and DFS with statistical significance, but only LODDS was found to be an independent prognostic factor for OS in multivariate analysis

    Serum Biomarkers of Renal Fibrosis: A Systematic Review

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    Chronic kidney disease (CKD) is a widely diffuse pathological condition which deeply impacts upon an affected patient’s quality of life and its worldwide rate is predicted to further rise. The main biological mechanism underlying CKD is renal fibrosis, a non-reversible process representing, for the affected system, a point of no return of tissue damage and dysfunction, deeply reducing the possible therapeutic strategies at the disposal of physicians. The best tool clinicians can use to address the extent of renal fibrosis at any level (glomeruli, tubule-interstitium, vasculature) is kidney biopsy that, despite its overall safety, remains an invasive procedure showing some shortcomings. Thus, the identification of novel non-invasive renal fibrosis biomarkers would be of fundamental importance. Here, when systematically reviewing the available evidence on serological biomarkers associated with renal fibrosis evaluated in patients suffering from CKD in the last five years, we found that despite the presence of several promising biomarkers, the level of observed evidence is still very scattered. Probably, the use of multiple measures capable of addressing different aspects involved in this condition would be the most suitable way to capture the high complexity characterizing the renal fibrotic process, having consequently a great impact on clinical practice by maximizing prevention, diagnosis, and management

    Fungal diversity in two wastewater treatment plants in North Italy

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    In urban wastewater treatment plants, bacteria lead the biological component of the depuration process, but the microbial community is also rich in fungi (mainly molds, yeasts and pseudo‐yeasts), whose taxonomical diversity and relative frequency depend on several factors, e.g., quality of wastewater input, climate, seasonality, and depuration stage. By joining morphological and molecular identification, we investigated the fungal diversity in two different plants for the urban wastewater treatment in the suburbs of the two major cities in Lombardia, the core of industrial and commercial activities in Italy. This study presents a comparison of the fungal diversity across the depuration stages by applying the concepts of α‐, β‐ and ζ‐diversity. Eurotiales (mainly with Aspergillus and Penicillium), Trichosporonales (Trichosporon sensu lato), Saccharomycetales (mainly with Geotrichum) and Hypocreales (mainly with Fusarium and Trichoderma) are the most represented fungal orders and genera in all the stages and both the plants. The two plants show different trends in α‐, β‐ and ζ‐diversity, despite the fact that they all share a crash during the secondary sedimentation and turnover across the depuration stages. This study provides an insight on which taxa potentially contribute to each depuration stage and/or keep viable propagules in sludges after the collection from the external environment

    Ascorbic acid reduces Ropivacaine-induced myotoxicity in cultured human osteoporotic skeletal muscle cells

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    Background: Osteoporosis is a worldwide health issue. Loss of bone mass is a potential risk factor for fragility fractures, and osteoporotic fractures place a considerable burden on society. Bone and muscle represent a functional unit in which the two tissues are intimately interconnected. Ropivacaine is a potent local anesthetic used in clinical practice for intraoperative anesthesia and postoperative pain management, in particular for hip surgery. When injected, Ropivacaine can diffuse locally through, in particular in surrounding skeletal muscle tissue, causing dose-dependent cytotoxicity, oxidative stress and myogenesis impairment. Based on those evidences, we focused our attention on Ropivacaine-induced cytotoxicity on cultured human myoblasts. Methods: Primary human myoblasts and myotubes from healthy subjects, osteoarthritic and osteoporotic patients (OP) were cultured in the presence of Ropivacaine. In some experiments, ascorbic acid (AsA) was added as a potent antioxidant agent. Cell viability and ROS levels were evaluated to investigate the myotoxic activity and Real-Time PCR and Western blot analysis carried out to investigate the expression of proliferation and myogenic markers. Results: A dose-dependent decrease of cell viability was observed after Ropivacaine exposure in both OP myoblasts and myotubes cultures, whereas those effects were not observed in the presence of Propofol, a general anesthetic. The adding of AsA reduced Ropivacaine negative effects in OP myoblast cultures. In addition, Ropivacaine exposure also increased ROS levels and upregulated Nox4 expression, an enzyme primarily implicated in skeletal muscle ROS generation. AsA treatment counteracted the oxidant activity of Ropivacaine and partially restored the basal condition in cultures. Positive myogenic markers, such as MyoD and Myf5, were downregulated by Ropivacaine exposure, whereas myostatin, a negative regulator of muscle growth and differentiation, was upregulated. The phenotypic deregulation of myogenic controllers in the presence of Ropivacaine was counteracted by AsA treatment. Conclusions: Our findings highlight the oxidative stress-mediated myotoxic effect of Ropivacaine on human skeletal muscle tissue cell cultures, and suggest treatment with AsA as valid strategy to mitigate its negative effects and allowing an ameliorated functional skeletal muscle recovery in patients undergoing hip replacement surgery for osteoporotic bone fracture

    From a Medicinal Mushroom Blend a Direct Anticancer Effect on Triple-Negative Breast Cancer: A Preclinical Study on Lung Metastases

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    Bioactive metabolites isolated from medicinal mushrooms (MM) used as supportive treatment in conventional oncology have recently gained interest. Acting as anticancer agents, they interfere with tumor cells and microenvironment (TME), disturbing cancer development/progression. Nonetheless, their action mechanisms still need to be elucidated. Recently, using a 4T1 triple-negative mouse BC model, we demonstrated that supplementation with Micotherapy U-Care, a MM blend, produced a striking reduction of lung metastases density/number, paralleled by decreased inflammation and oxidative stress both in TME and metastases, together with QoL amelioration. We hypothesized that these effects could be due to either a direct anticancer effect and/or to a secondary/indirect impact of Micotherapy U-Care on systemic inflammation/immunomodulation. To address this question, we presently focused on apoptosis/proliferation, investigating specific molecules, i.e., PARP1, p53, BAX, Bcl2, and PCNA, whose critical role in BC is well recognized. We revealed that Micotherapy U-Care is effective to influence balance between cell death and proliferation, which appeared strictly interconnected and inversely related (p53/Bax vs. Bcl2/PARP1/PCNA expression trends). MM blend displayed a direct effect, with different efficacy extent on cancer cells and TME, forcing tumor cells to apoptosis. Yet again, this study supports the potential of MM extracts, as adjuvant supplement in the TNBC management
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