162 research outputs found
Development of a green scalable route toward the synthesis of bio-based 2-pyrones
2-Pyrones are molecules that gained significant attention in the field of medicine and synthetic chemistry.
They are broadly present in nature, where they play an important role in the defense mechanisms of the
organisms in which they are present. Due to their unique structure, 2-pyrones hold immense potential
both for the development of pharmacologically active compounds and as building blocks in synthetic
chemistry; for these reasons those molecules have attracted researcher's attention during the past decade.
In this work, we present the synthesis optimization of bio-based 2-pyrones starting from bio sourced
galactaric acid by means of a statistical design of experiment, its scale up from 500 mg to 100 g, the
solvent recycling to make the reaction greener as well as the synthesis of galactaric acid from galactose
Development of a flow process for an easy and fast access to 2-pyrone derivatives
2-Pyrones are compounds widely present in nature and they represent interesting building blocks both in medicinal and synthetic chemistry. Due to their peculiar pharmacological activity and structure, they have attracted much attention during the last decades and several protocols for their synthesis have been developed. In this work we propose the synthesis of bio-sourced 2-pyrones, exploiting continuous-flow conditions for an easy, sustainable and fast access to these important molecules
Antioxidant and UV-Blocking Functionalized Poly(Butylene Succinate) Films
The introduction of a limited number of functional groups on poly(butylene succinate) (PBS) chains by covalent bonding can impart new properties to the polymer without modifying its thermal and mechanical properties. In pursuit of a viable approach to obtain light- and heat-stabilized PBS samples, the nitroxide radical coupling (NRC) reaction between PBS macroradicals and the 3,5-di-tert-butyl-4-hydroxybenzoyl-2,2,6,6-tetramethylpiperidine-1-oxyl radical (BHB-TEMPO), a functionalizing agent bearing a sterically-hindered antioxidant phenol moiety, is here proposed. The reaction was initiated by peroxide and carried out in solution and in a melt. The functionalized materials were characterized by UV-visible spectroscopy (UV-Vis), proton nuclear magnetic resonance (1H-NMR), and size exclusion chromatography (SEC) analysis to gain structural information and by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) to investigate the thermal properties. In addition, films of the samples were subjected to thermal and photo-oxidative aging to assess their resistance to degradative processes. Finally, the PBS film with the highest degree of functionalization showed the ability to protect β-carotene, a molecule found in food and drugs and that is very sensitive to UV light, from degradation. This result suggests the use of this material (either alone or blended with other biopolyesters) for biodegradable and compostable active packaging
Inflammation and infiltration: can the radiologist draw a line? MRI versus CT to accurately assess medullary involvement in parosteal osteosarcoma
Cancer causes inflammation as it progresses through healthy tissue. The differentiation of tumoral growth from the surrounding inflammatory change is paramount in planning surgeries seeking to preserve function. This retrospective study aims at illustrating how a careful use of imaging (computed tomography (CT)/magnetic resonance imaging (MRI)) can help to draw the line between infiltration and inflammation. Out of 72 cases of parosteal osteosarcoma in our institution we selected 22 which had pretreatment imaging, and out of those, 14 that had both MRI and CT. Using Fisher’s exact test, we evaluated the performance of each technique on accurately diagnosing medullary tumor infiltration, using histological analysis as a gold standard. All cases (14/14) demonstrated medullary abnormality on MRI, but only 6/14 (42.9%) demonstrated abnormality on CT. The 8/14 cases with MRI abnormality but no CT abnormality (57.1%) showed inflammation with no tumoral cells present on histological analysis. In the cases where the two examinations showed medullary abnormality (6/14) histology demonstrated tumoral infiltration. MRI demonstrated high sensitivity and negative predictive value, but low specificity and low positive predictive value and accuracy (P=1). CT demonstrated high sensitivity, specificity, high positive and negative predictive values and accuracy (P = 0.000333). MRI is highly sensitive for the detection of medullary abnormality but lacks specificity for tumor invasion. Correlation with CT is recommended in all cases of positive MR to add specificity for tumors. The adequate use of the two imaging methods allows to differentiate between inflammatory change and tumoral infiltration in POS, relevant for surgical planning
Proton pump inhibitor chemosensitization in human osteosarcoma: from the bench to the patients' bed.
BACKGROUND:
Major goals in translational oncology are to reduce systemic toxicity of current anticancer strategies and improve effectiveness. An extremely efficient cancer cell mechanism to avoid and/or reduce the effects of highly cytotoxic drugs is the establishment of an acidic microenvironment, an hallmark of all malignant tumors. The H\u2009+-rich milieu that anticancer drugs meet once they get inside the tumor leads to their protonation and neutralization, therefore hindering their access into tumor cells. We have previously shown that proton pump inhibitors (PPI) may efficiently counterattack this tumor advantage leading to a consistent chemosensitization of tumors. In this study, we investigated the effects of PPI in chemosensitizing osteosarcoma.
METHOD:
MG-63 and Saos-2 cell lines were used as human osteosarcoma models. Cell proliferation after pretreatment with PPI and subsequent treatment with cisplatin was evaluated by using erythrosin B dye vital staining. Tumour growth was evaluated in xenograft treated with cisplatin after PPI pretreatment. Subsequently, a multi-centre historically controlled trial, was performed to evaluate the activity of a pre-treatment administration of PPIs as chemosensitizers during neoadjuvant chemotherapy based on methotrexate, cisplatin, and adriamycin.
RESULTS:
Preclinical experiments showed that PPI sensitize both human osteosarcoma cell lines and xenografts to cisplatin. A clinical study subsequently showed that pretreatment with PPI drug esomeprazole leads to an increase in the local effect of chemotherapy, as expressed by percentage of tumor necrosis. This was particularly evident in chondroblastic osteosarcoma, an histological subtype that normally shows a poor histological response. Notably, no significant increase in toxicity was recorded in PPI treated patients.
CONCLUSION:
This study provides the first evidence that PPI may be beneficially added to standard regimens in combination to conventional chemotherapy
Comparison of Branched and Linear Perfluoropolyether Chains Functionalization on Hydrophobic, Morphological and Conductive Properties of Multi-Walled Carbon Nanotubes
The functionalization of multi-walled carbon nanotubes (MW-CNTs) was obtained by
generating reactive perfluoropolyether (PFPE) radicals that can covalently bond to MW-CNTs\u2019
surface. Branched and linear PFPE peroxides with equivalent molecular weights of 1275 and
1200 amu, respectively, have been thermally decomposed for the production of PFPE radicals.
The functionalization with PFPE chains has changed the wettability of MW-CNTs, which switched
their behavior from hydrophilic to super-hydrophobic. The low surface energy properties of PFPEs
have been transferred to MW-CNTs surface and branched units with trifluoromethyl groups, CF3,
have conferred higher hydrophobicity than linear units. Porosimetry discriminated the effects of
PFPE functionalization on meso-porosity and macro-porosity. It has been observed that reactive sites
located in MW-CNTs mesopores have been intensively functionalized by branched PFPE peroxide
due to its low average molecular weight. Conductivity measurements at different applied pressures
have showed that the covalent linkage of PFPE chains, branched as well as linear, weakly modified
the electrical conductivity of MW-CNTs. The decomposed portions of PFPE residues, the PFPE
chains bonded on carbon nanotubes, and the PFPE fluids obtained by homo-coupling side-reactions
were evaluated by mass balances. PFPE-modified MW-CNTs have been characterized by X-ray
photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis
(TGA), static contact angle (SCA), surface area, and porosity measurements
Indications and Limits of Surgery for Spinal Metastases Derived from Lung Cancer: A Single-Center Experience
Lung cancer is the second most frequently diagnosed cancer in the world, and surgery is an integral part of the treatment for spinal metastases. The aims of this retrospective study were to assess the overall survival of surgically treated patients affected by lung cancer spinal metastases and identify any factors related to a better survival rate. We recruited 56 consecutive patients (34 male and 22 female) surgically treated for metastatic lung cancer in the spine from 2009 to 2019. Surgical indications were based on a previously published and validated flow chart following a multidisciplinary evaluation. We assessed the localization of vertebral metastases, the presence of other bone or visceral metastases, neurological status according to the Frankel score, ambulatory autonomy, and general status, measured with the Karnofsky performance scale. The expected prognosis was retrospectively assessed according to the revised Tokuhashi score. The median survival was 8.1 months, with over a third of patients surviving more than 1 year. We observed a global improvement in all clinical parameters after surgical treatment. The Tokuhashi predictive score did not correlate with survival after surgery. The results of this study suggest that the surgical treatment of symptomatic spinal metastases from lung cancer can improve quality of life, even in patients with a shorter life expectancy, by controlling pain and improving autonomy
Dideoxynucleoside HIV reverse transcriptase inhibitors and drug-related hepatotoxicity: a case report
This report regards the case of a 43 year-old HIV-positive woman who developed an episode of serious transaminase elevation during stavudine-including antiretroviral therapy. Diagnostic assessment ruled out hepatitis virus co-infection, alcohol abuse besides other possible causes of liver damage. No signs of lactic acidosis were present. Liver biopsy showed portal inflammatory infiltrate, spotty necrosis, vacuoles of macro- and micro-vesicular steatosis, acidophil and foamy hepatocytes degeneration with organelles clumping, poorly formed Mallory bodies and neutrophil granulocytes attraction (satellitosis). A dramatic improvement in liver function tests occurred when stavudine was discontinued and a new antiretroviral regimen with different nucleoside reverse transcriptase inhibitors was used. The importance of considering hepatotoxicity as an adverse event of HAART including stavudine, even in absence of other signs of mitochondrial toxicity should therefore be underlined. Liver biopsy may provide further important information regarding patients with severe transaminase elevation, for a better understanding of the etiology of liver damage
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