University of Siena

Archivio della Ricerca - Università degli Studi di Siena
Not a member yet
    83334 research outputs found

    Inhibition of cell cycle progression by the hydroxytyrosol-cetuximab combination yields enhanced chemotherapeutic efficacy in colon cancer cells

    Get PDF
    Hydroxytyrosol (HT), a polyphenol of olive oil, downregulates epidermal growth factor (EGFR) expression and inhibits cell proliferation in colon cancer (CC) cells, with mechanisms similar to that activated by the EGFR inhibitor, cetuximab. Here, we studied whether HT treatment would enhance the cetuximab inhibitory effects on cell growth in CC cells. HT-cetuximab combination showed greater efficacy in reducing cell growth in HT- 29 and WiDr cells at concentrations 10 times lower than when used as single agents. This reduction was clearly linked to cell cycle blockade, occurring at G2/M phase. The cell cycle arrest in response to combination treatment is related to cyclins B, D1, and E, and cyclin-dependent kinase (CDK) 2, CDK4, and CDK6 down-regulation, and to the concomitant over-expression of CDK inhibitors p21 and p27. HT and cetuximab stimulated a caspase-independent cell death cascade, promotedtranslocation of apoptosis-inducing factor (AIF) from mitochondria to nucleus and activated the autophagy process. Notably, normal colon cells and keratinocytes were less susceptible to comboinduced cell death and EGFR downregulation. These results suggest a potential role of diet, containing olive oil, during cetuximab chemotherapy of colon tumor. HT may be a competent therapeutic agent in CC enhancing the effects of EGFR inhibitors

    EMPTYSCAPES. Towards Filling Gaps in Mediterranean Landscape Archaeology

    Get PDF
    The aim of the project is to use the ‘traditional’ methods of landscape survey in partnership with large-scale geophysical prospection, in due course airborne laser scanning, geo-archaeological and bio-archaeological. The research area is a stretch of a rural valley near the ancient city of Rusellae in southern Tuscany exploring completely new ground of a rural emptyscape. The Etruscan and Roman city of Rusellae has been relatively well explored in the past, with a history running in fairly well-defined phases of foundation, elaboration and decline from the 8th or 9th centuries BC to the early 12th century AD, when primacy and the local bishopric were ceded to the growing town of Grosseto a few km to the south-west. At least some of the developments within the ancient city are known or suspected to have been matched by developments or transformations within the open landscape of the valley, including the foundation and decline of rural villas and (possibly) of centuriation during the Roman period. Villages of one kind or another may also have been present during the Iron Age and Early Medieval periods, though their location and form remain unclear. Today, the slopes either side of the valley are largely wooded. The relatively flat and topographically undistinctive landscape between present-day Grosseto and the site of Rusellae is now displays a rotating mixture of arable cultivation and pasture, dotted with small areas of woodland, vineyards and olive cultivation. A trapeze-shaped sample transect covering 2500 ha of the valley and hillslopes to the south-east of Rusellae was chosen as offering opportunities to explore a range of environmental and archaeological contexts, with lowland fields appropriate for magnetic survey flanked by wooded hillslopes which in due course will act as a test-bed for high-resolution laser scanning

    Bisphosphonates, atherosclerosis and vascular calcification: Update and systematic review of clinical studies

    Get PDF
    Background: Epidemiologic and clinical data have suggested the existence of a biologic linkage between the bone system and the vascular system. Bisphosphonates (BPs) are effective inhibitors of bone resorption and are currently considered the drugs of choice for the preven­tion and treatment of osteoporosis and related fractures. Data from several publications have suggested that BPs may also be effective in reducing the atherosclerotic process and vascular calcification, but the results of these studies are contrasting. This review aimed to allow a better understanding of the relationships between BPs and atherosclerosis in humans. Materials and methods: Electronic databases of Pubmed-Medline, Cochrane Library and SCOPUS from inception to June 30, 2016 were searched. The full texts of the articles potentially eligible were carefully assessed and reviewed. Finally, 20 studies were found to be eligible and were included in the systematic review. All included studies were published between 2000 and 2014. Results: In several studies, etidronate limited the progression of aortic and coronary calcification in hemodialysis patients, whereas the nitrogen-containing-BPs given orally did not significantly reduce vascular calcifications in patients with chronic kidney disease, kidney trasplant or in those with osteoporosis. Nitrogen-containing-BPs present favorable effects both on vessel wall thickness and on arterial elasticity due to both a reduction in serum lipids and the interaction of BPs with the bone tissue, with the consequent release of bone turnover markers and cytokines into the bloodstream. Conclusion: To sum up, the BPs seem to have the potential of influencing atherosclerosis and calcium homeostasis at the level of vascular walls with several possible mechanisms which may differ according to the type, potency, dosage and administration route of BPs. Additional studies are needed to specifically address the mechanism by which BP use could influence cardiovascular morbidity and mortality

    Calcium supplementation and risk of cardiovascular disease

    Get PDF
    With the outcome to demonstrate the efficacy of calcium to prevent the incidence of fractures many randomized controlled trials have been performed in the past two decades, with conflicting results. A RR of 0.86 for non-vertebral fractures and a RR of 0.91 for hip fractures on eight trials were demonstrated. Calcium supplementation is considered particularly important when baseline calcium intake is low. More recently WHI CaD Study indicated that calcium supplements with or without vitamin D represent a factor risk for cardiovascular events. On the other hand the beneficial effect of Edizioni a correct calcium intake in attaining and maintaining bone mass across the life is largely demonstrated. There is an urgent need for more research to gain insight into the mechanisms of the adverse vascular effect of calcium. Moreover, more extensive data about the incidence of cardiovascular adverse events coming from randomized controlled intervention trials in osteoporosis, in which calcium plus Vitamin D were utilized, might be achieved

    Comparison between Harpagophytum capsules: assessment of variability of harpagoside content and of antioxidant properties

    Get PDF
    Devil's claw (Harpagophytum procumbens D.C.) is a perennial herbaceous plant that grows exclusively in the Kalahari Desert, an arid region of southern Africa. Its secondary tuberous roots are dried and commonly used in South African traditional medicine. In Europe capsules containing the dried extract are widely employed in the treatment of rheumatic disorders, low back pain, loss of appetite and dyspeptic complaints. The anti-inflammatory and analgesic effects of Harpagophytum procumbens and harpagoside, its main iridoid glycoside, have largely been studied (1). Grant et al. (2) hypothesized that these putative properties of Harpagophytum might be a consequence, at least in part, of its antioxidant effects. The purpose of the present study was to verify quality and quantity of the micronized root powder contained in commercial capsules, to measure their content of harpagoside and to evaluate their potential antioxidant properties. Three samples of capsules containing Harpagophytum procumbens of different commercial origin were examined. The root powder contained in the capsules was weighed and used to prepare ethanolic extracts. The harpagoside content was determined by the Ouitas method (3); the antioxidant activity was evaluated by the FRAP and DPPH methods (4); the polyphenol content was measured according to a protocol used in our lab (4); finally, the ascorbic acid content was determined by the Ross method (5). The results obtained showed a certain variability in both quality and quantity of the phytopreparations examined. In two formulations the root powder content was lower than declared (-16.8% and -22.9%). All the phytopreparations showed antioxidant properties; in particular, the highest antioxidant activity was observed in the formulation containing the greatest amount of harpagoside (three times higher than that of the others, P<0.001) and the highest levels of polyphenols (+10%; P<0.001) and ascorbic acid (+187%; P<0.001). A significant correlation was found between antioxidant activity and harpagoside content (r=0.99) and between antioxidant activity and polyphenol content (r=0.99). However, the commercial preparation with the highest content in harpagoside did not comply with the European Pharmacopoeia (the drug should contain at least 1.2% of harpagoside as determined by HPLC). Having access to a variety of products sharing a similar appearance, the patient may experience widely variable therapeutic responses, since the minimum harpagoside content requested by the current pharmacopoeia monographs is not always observed by the manufacturers. Stringent controls should be performed in order to ensure quality among the products based on Harpagophytum procumbens. Growing evidence of effectiveness is counterbalanced by inadequate regulation. References 1. Mncwangi et al. (2012). Journal of Ethnopharmacology. 143, 755–771. 2. Grant et al. (2009). Phytother Res. 23, 104-10. 3. Ouitas et al. (2010). Phytother Res. 24, 333-8. 4. Nencini et al. (2011). Plant Foods Hum Nutr. 66, 11-6. 5. Ross (1994). J Chromatogr B Biomed Sci Appl. 657, 197-200

    Esophagogastric dissociation reduces the re-operation rate for persistent gastroesophageal reflux in severely neurologically impaired children

    Get PDF
    Purpose: In this study we want to demonstrate the effectiveness of the esophagogastric dissociation as a first level operation in treatment of the gastroesophageal reflux in severe neurologically impaired children, in term of a reduction of reoperation rate.Methods: We divided patients operated from 1998 to 2005 in a group A, composed by children treated with fundoplication, and in a group AR, composed by the patients of group A who had a recurrence of reflux and that was treated with esophagogastric dissociation. Patients operated from 2005 to 2013 were selected on the basis of the severity of the neurological impairment and were divided in a group B, treated with fundoplication, and in a group C of more severe impaired children, treated with esophagogastric dissociation. Data regarding the complications of the A and C groups were analyzed with Fisher’s test.Results: We evaluated 63 patients: 34 (54 %) in group A, 11 in group AR, 15 (23.6 %) in group B, 14 (22.4 %) in group C. The Fisher’s test showed a non significant difference with a p value of 0.2.Conclusion: Despite of statistic result we believe that TOGD is a useful procedure as the first choice of surgical management in severe neurological impaired children affected by gastroesophageal reflux

    Functional and genetic characterization of clinical malignant hyperthermia crises: a multi-centre study

    Get PDF
    Malignant hyperthermia (MH) is a rare pharmacogenetic disorder which is characterized by life-threatening metabolic crises during general anesthesia. Classical triggering substances are volatile anesthetics and succinylcholine (SCh). The molecular basis of MH is excessive release of Ca2+ in skeletal muscle principally by a mutated ryanodine receptor type 1 (RyR1). To identify factors explaining the variable phenotypic presentation and complex pathomechanism, we analyzed proven MH events in terms of clinical course, muscle contracture, genetic factors and pharmocological triggers.In a multi-centre study including seven European MH units, patients with a history of a clinical MH episode confirmed by susceptible (MHS) or equivocal (MHE) in vitro contracture tests (IVCT) were investigated. A test result is considered to be MHE if the muscle specimens develop pathological contractures in response to only one of the two test substances, halothane or caffeine. Crises were evaluated using a clinical grading scale (CGS), results of IVCT and genetic screening. The effects of SCh and volatile anesthetics on Ca2+ release from sarcoplasmic reticulum (SR) were studied in vitro.A total of 200 patients met the inclusion criteria. Two MH crises (1%) were triggered by SCh (1 MHS, 1 MHE), 18% by volatile anesthetics and 81% by a combination of both. Patients were 70% male and 50% were younger than 12 years old. Overall, CGS was in accord with IVCT results. Crises triggered by enflurane had a significantly higher CGS compared to halothane, isoflurane and sevoflurane. Of the 200 patients, 103 carried RyR1 variants, of which 14 were novel. CGS varied depending on the location of the mutation within the RyR1 gene. In contrast to volatile anesthetics, SCh did not evoke Ca2+ release from isolated rat SR vesicles.An MH event could depend on patient-related risk factors such as male gender, young age and causative RyR1 mutations as well as on the use of drugs lowering the threshold of myoplasmic Ca2+ release. SCh might act as an accelerant by promoting unspecific Ca2+ influx via the sarcolemma and indirect RyR1 activation. Most MH crises develop in response to the combined administration of SCh and volatile anesthetics

    Hypertension, left ventricular hypertrophy and chronic kidney disease.

    Get PDF
    Left ventricular hypertrophy (LVH) is a cardiovascular complication highly prevalent in patients with chronic kidney disease (CKD) and end-stage renal disease. LVH in CKD patients has generally a negative prognostic value, because it represents an independent risk factor for the development of arrhythmias, sudden death, heart failure and ischemic heart disease. LVH in CKD patients is secondary to both pressure and volume overload. Pressure overload is secondary to preexisting hypertension, but also to a loss of elasticity of the vessels and to vascular calcifications, leading to augmented pulse pressure. Anemia and the retention of sodium and water secondary to decreased renal function are responsible for volume overload, determining a hyperdynamic state. In particular, the correction of anemia with erythropoietin in CKD patients is advantageous, since it determines LVH reduction. Other risk factors for LVH in CKD patients are documented: some are specific to CKD, as mineral metabolism disorders (hypocalcemia, hyperphosphatemia, low serum vitamin D levels and secondary hyperparathyroidism), others are non-traditional, such as increased asymmetric dimethylarginine, oxidative stress, hyperhomocysteinemia and endothelial dysfunction that, in turn, accelerates the process of atherogenesis, triggers the inflammation and pro-thrombotic state of the glomerular and the vascular endothelium and aggravates the process of both CKD and LVH

    Increasing prevalence of multiple sclerosis in Tuscany: a study based on validated administrative data

    Get PDF
    AIMS Italy is a high-risk area for Multiple Sclerosis (MS) with a prevalence of around 140/105 (2009) with the exception of Sardinia, with about 224 cases/105 (2009). Nowadays, in Italy, prevalence is absolutely higher than the above estimates. Indeed, prevalence is rising due to annual incidence that is higher than annual mortality. In Tuscany a population MS register has been founded but, to date, it’s not yet completed. To monitor disease epidemiology, comorbidities and care pathways, but also to describe the disease burden and to plan its prevention, treatment and management strategies and resource allocation, population-based studies are preferable. Administrative data offer a unique opportunity for population-based prevalence study of chronic diseases such as MS. Our aim is to update the prevalence of MS in Tuscany and to demonstrate its progressive increment. METHODS The prevalence was calculated using a case-finding algorithm based on administrative data: hospitalization, specific MS drug dispensing, disease-specific exemptions from patient copayment, home and residential long-term care and inhabitant registry. To test algorithm sensitivity, we used a true-positive reference cohort of 302 MS patients from the Tuscan MS register. To test algorithm specificity, we used a general population cohort of 2,644,094 individuals who were presumably not affected by MS (who had never effectuated either cranial or spinal cord CT scan or MRI and had never received a neurological outpatient visit within the NHS). We calculated prevalence on three consecutive years (2011, 2012, 2013). RESULTS At prevalence date (31 December), we identified 6,890 cases in 2011, 7,057 in 2012 and 7,330 in 2013 with a rate of 187.9, 191.1 and 195.4/105, respectively. The female:male ratio slightly increased from 2.0 in 2011 to 2.1 in 2012-2013. The sensitivity of algorithm was 98% and its specificity was 99.99%. DISCUSSION We found a progressive increment of prevalence that confirmed our hypothesis of increasing prevalence. Although our validity study demonstrated a high level of sensibility, we could miss some patients, especially individuals with a severe MS, who did not access the healthcare system and who did not use the DMDs included in our algorithm. CONCLUSIONS We confirmed that Tuscany is a high-risk area for MS and that the prevalence is increasing over time. Despite some limitations, we also demonstrated that our algorithm can accurately identify patients and this cohort is suitable to monitor care pathways. Our future aim is to create an integrated dataset with administrative and clinical data from MS register


    full texts


    metadata records
    Updated in last 30 days.
    Archivio della Ricerca - Università degli Studi di Siena is based in IT
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇