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1.
Sci Total Environ ; 948: 174847, 2024 Oct 20.
Article in English | MEDLINE | ID: mdl-39025142

ABSTRACT

Citizen science has been particularly effective in gathering reliable, timely, large-scale data on the presence and distributions of animal species, including mosquito vectors of human and zoonotic pathogens. This involves the participation of citizen scientists in research projects, with success strongly dependent on the capacity to disseminate project information and engage citizen scientists to contribute their time. Mosquito Alert is a citizen science that aids in the system surveillances of vector mosquitoes. It involves citizen scientists providing expert-validated photos of targeted mosquitoes, along with records of bites and breeding sites. Since 2020 the system has been disseminated throughout Europe. This article uses models to analyze the effect of promotion activities carried out by the Mosquito Alert ITALIA team from October 2020 to December 2022 on the number of citizen scientists recruited and engaged in the project, and their performance in mosquito identification. Results show a high level of citizen scientist recruitment (N > 18.000; 37 % of overall European participants). This was achieved mostly through articles generated by ad hoc press releases detailing the app's goals and functioning. Press releases were more effective when carried out at the beginning and end of the mosquito season and when mosquito's public health significance was emphasized. Despite the high number of records received (N > 20.000), only 30 % of registered participants sent records, and the probability of a participant sending a record dropped off quickly over time after first registering. Among participants who contributed, ∼50 % sent 1 record, ∼30 % ≥3 and 4 % >10 records. Participants showed good capacity to identify mosquitoes and improve identification skills with app usage. The results will be valuable for anyone interested in evaluating citizen science, as participation and engagement are seldom quantitatively assessed. Our results are also useful for designing dissemination and education strategies in citizen science projects associated with arthropod vector monitoring.


Subject(s)
Citizen Science , Mosquito Vectors , Zoonoses , Italy , Animals , Humans , Arthropod Vectors , Culicidae , Mosquito Control/methods
2.
Res Sq ; 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38562903

ABSTRACT

The two main Afrotropical malaria vectors - Anopheles coluzzii and An. gambiae - are genetically distinct and reproductively isolated across West Africa. However, populations at the western extreme of their range are assigned as "intermediate" between the two species by whole genome sequence (WGS) data, and as hybrid forms by conventional molecular diagnostics. By exploiting WGS data from 1,190 specimens collected across west Africa via the Anopheles gambiae 1000 Genomes network, we identify a novel putative taxon in the far-west (provisionally named Bissau molecular form), which did not arise by admixture but rather originated at the same time as the split between An. coluzzii and An. gambiae. Intriguingly, these populations lack insecticide resistance mechanisms commonly observed in the two main species. These findings lead to a change of perspective on malaria vector species in the far-west region with potential for epidemiological implications, and a new challenge for genetic-based mosquito control approaches.

4.
Pulmonology ; 2021 Apr 17.
Article in English | MEDLINE | ID: mdl-33879426

ABSTRACT

The design of e-cigarettes (e-cigs) is constantly evolving and the latest models can aerosolize using high-power sub-ohm resistance and hence may produce specific particle concentrations. The aim of this study was to evaluate the aerosol characteristics generated by two different types of electronic cigarette in real-world conditions, such as a sitting room or a small office, in number of particles (particles/cm3). We compared the real time and time-integrated measurements of the aerosol generated by the e-cigarette types Just Fog and JUUL. Real time (10s average) number of particles (particles/cm3) in 8 different aerodynamic sizes was measured using an optical particle counter (OPC) model Profiler 212-2. Tests were conducted with and without a Heating, Ventilating Air Conditioning System (HVACS) in operation, in order to evaluate the efficiency of air filtration. During the vaping sessions the OPC recorded quite significant increases in number of particles/cm3. The JUUL e-cig produced significantly lower emissions than Just Fog with and without the HVACS in operation. The study demonstrates the rapid volatility or change from liquid or semi-liquid to gaseous status of the e-cig aerosols, with half-life in the order of a few seconds (min. 4.6, max 23.9), even without the HVACS in operation. The e-cig aerosol generated by the JUUL proved significantly lower than that generated by the Just Fog, but this reduction may not be sufficient to eliminate or consistently reduce the health risk for vulnerable non e-cig users exposed to it.

5.
Sci Rep ; 11(1): 6256, 2021 03 18.
Article in English | MEDLINE | ID: mdl-33737616

ABSTRACT

Evidences of an association between air pollution and Covid-19 infections are mixed and inconclusive. We conducted an ecological analysis at regional scale of long-term exposure to air-borne particle matter and spread of Covid-19 cases during the first wave of epidemics. Global air pollution and climate data were calculated from satellite earth observation data assimilated into numerical models at 10 km resolution. Main outcome was defined as the cumulative number of cases of Covid-19 in the 14 days following the date when > 10 cumulative cases were reported. Negative binomial mixed effect models were applied to estimate the associations between the outcome and long-term exposure to air pollution at the regional level (PM10, PM2.5), after adjusting for relevant regional and country level covariates and spatial correlation. In total we collected 237,749 Covid-19 cases from 730 regions, 63 countries and 5 continents at May 30, 2020. A 10 µg/m3 increase of pollution level was associated with 8.1% (95% CI 5.4%, 10.5%) and 11.5% (95% CI 7.8%, 14.9%) increases in the number of cases in a 14 days window, for PM2.5 and PM10 respectively. We found an association between Covid-19 cases and air pollution suggestive of a possible causal link among particulate matter levels and incidence of COVID-19.


Subject(s)
Air Pollution/adverse effects , COVID-19/epidemiology , Particulate Matter/adverse effects , COVID-19/etiology , Humans , Incidence
6.
Nat Commun ; 11(1): 5957, 2020 Nov 24.
Article in English | MEDLINE | ID: mdl-33235190

ABSTRACT

Metals and polymers are dissimilar materials in terms of their physicochemical properties, but complementary in terms of functionality. As a result, metal-organic structures can introduce a wealth of novel applications in small-scale robotics. However, current fabrication techniques are unable to process three-dimensional metallic and polymeric components. Here, we show that hybrid microstructures can be interlocked by combining 3D lithography, mold casting, and electrodeposition. Our method can be used to achieve complex multi-material microdevices with unprecedented resolution and topological complexity. We show that metallic components can be combined with structures made of different classes of polymers. Properties of both metals and polymers can be exploited in parallel, resulting in structures with high magnetic responsiveness, elevated drug loading capacity, on-demand shape transformation, and elastic behavior. We showcase the advantages of our approach by demonstrating new microrobotic locomotion modes and controlled agglomeration of swarms.

7.
J Exp Clin Cancer Res ; 36(1): 104, 2017 08 03.
Article in English | MEDLINE | ID: mdl-28774348

ABSTRACT

BACKGROUND: Ferritin plays a central role in the intracellular iron metabolism; the molecule is a nanocage of 24 subunits of the heavy and light types. The heavy subunit (FHC) is provided of a ferroxidase activity and thus performs the key transformation of iron in a non-toxic form. Recently, it has been shown that FHC is also involved in additional not iron-related critical pathways including, among the others, p53 regulation, modulation of oncomiRNAs expression and chemokine signalling. Epithelial to mesenchymal transition (EMT) is a cellular mechanism by which the cell acquires a fibroblast-like phenotype along with a decreased adhesion and augmented motility. In this work we have focused our attention on the role of the FHC on EMT induction in the human cell lines MCF-7 and H460 to elucidate the underlying molecular mechanisms. METHODS: Targeted silencing of the FHC was performed by lentiviral-driven shRNA strategy. Reconstitution of the FHC gene product was obtained by full length FHC cDNA transfection with Lipofectamine 2000. MTT and cell count assays were used to evaluate cell viability and proliferation; cell migration capability was assayed by the wound-healing assay and transwell strategy. Quantification of the CXCR4 surface expression was performed by flow cytometry. RESULTS: Experimental data indicated that FHC-silenced MCF-7 and H460 cells (MCF-7shFHC, H460shFHC) acquire a mesenchymal phenotype, accompanied by a significant enhancement of their migratory and proliferative capacity. This shift is coupled to an increase in ROS production and by an activation of the CXCR4/CXCL12 signalling pathway. We present experimental data indicating that the cytosolic increase in ROS levels is responsible for the enhanced proliferation of FHC-silenced cells, while the higher migration rate is attributable to a dysregulation of the CXCR4/CXCL12 axis. CONCLUSIONS: Our findings indicate that induction of EMT, increased migration and survival depend, in MCF-7 and H460 cells, on the release of FHC control on two pathways, namely the iron/ROS metabolism and CXCR4/CXCL12 axis. Besides constituting a further confirmation of the multifunctional nature of FHC, this data also suggest that the analysis of FHC amount/function might be an important additional tool to predict tumor aggressiveness.


Subject(s)
Apoferritins/metabolism , Chemokine CXCL12/metabolism , Receptors, CXCR4/metabolism , Apoferritins/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation/physiology , Epithelial-Mesenchymal Transition , Female , Gene Silencing , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , MCF-7 Cells , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , Transfection
8.
Monaldi Arch Chest Dis ; 79(1): 8-11, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23741940

ABSTRACT

BACKGROUND AND AIM: The hazardous health effects of smoking and second-hand smoke are well known and have been confirmed in several studies. We wondered whether a school based programme involving media models such as those represented by famous soccer players and TV characters, was effective in prevention of smoking habit in secondary school adolescents. METHODS: Since October 2006 to May 2007 an anonymous survey was submitted to 1382 secondary schools pupils. After completing the questionnaire all students of 42 out of 70 classes selected by the school principals underwent a prevention programme consisting of 1 hour lecture on smoke healthy hazard with educational material (slides, video, leaflets). Furthermore each pupil was given card games with significant pictures. Since October 2007 to May 2008 and Since October 2008 to May 2009 pupils underwent a 1 hour interactive lesson on smoke related health hazards respectively. On December 2007 pupils in study attended a theatre event with show business characters acting to smoke dissuasion. No intervention was performed on the 568 pupils of the other classes along all the same 2 school- year period (controls). RESULTS: Among other results at the end of the 2-year program 4% pupils of study group and 14% of controls reported smoking habit (p = 0.001) whereas 7% and 27% (p = 0.001) of study and control pupils respectively ignored smoking induced dependence. CONCLUSION: A school based programme involving media models such as those represented by famous soccer players, TV characters, was effective in prevention of smoking habit in secondary school adolescents.


Subject(s)
Health Education , Schools , Smoking Prevention , Child , Female , Humans , Male , Surveys and Questionnaires
9.
J Oncol ; 2011: 145617, 2011.
Article in English | MEDLINE | ID: mdl-21776269

ABSTRACT

Smoking cessation is necessary to reach a higher quality of life, and, for a cancer patient, it represents an important step in improving the outcome of both prognosis and therapy. Being a cancer patient addicted to nicotine may be a critical situation. We conducted a survey to monitor how many comprehensive cancer centres in Italy have an outpatient smoker clinic and which kinds of resources are available. We also inquired about inpatient services offering psychological and pharmacological support for smoking cessation, reduction, or care of acute nicotine withdrawal symptoms. What we have witnessed is a significant gap between guidelines and services. Oncologists and cancer nurses are overscheduled, with insufficient time to engage in discussion on a problem that they do not consider directly related to cancer treatment. Furthermore, smoking habits and limited training in tobacco dependence and treatment act as an important barrier and lead to the undervaluation of smokers' needs.

10.
Ann Oncol ; 21(7): 1404-1409, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20089563

ABSTRACT

A cancer patient who smokes is a very fragile person and we identify in scientific literature three main areas of clinical practice and research to develop the care of smokers with cancer. (i) Telling facts: smoking impacts on the survival and on the outcomes of surgery, chemo-, radio- and biological therapies. The aim of our intervention was to enable patients to make informed choices about smoking. (ii) Offering sensitive and effective smoking cessation like an instrument of patient empowerment to motivate change in smoker patient lifestyle. (iii) Assisting smoker patients if they develop acute nicotine withdrawal symptoms. Smoking care and nicotine replacement therapy can support temporary abstinence during the inpatient stay and providing patients with an opportunity for smoking cessation can prompt a future permanent quit attempt. Comprehensive cancer centers must act like a promoter of a better smokers' care, applying guidelines to their reality and try to do more research on smokers' needs and on the resources to assist them. Only the alliance between victims of smoking addiction and health personnel can give a chance against the tobacco epidemic.


Subject(s)
Neoplasms/psychology , Smoking Cessation/methods , Behavior Therapy , Humans , Smoking Cessation/psychology
11.
G Chir ; 31(11-12): 497-501, 2010.
Article in Italian | MEDLINE | ID: mdl-21232191

ABSTRACT

The incidence of gastrointestinal complications in renal transplant recipients is relatively high while about 10% is related to acute abdomen. Data concerning gastrointestinal (GI) complications were reported in literature mainly from referral center studies. A multicenter retrospectively survey was performed in Lazio, Italy, in order to evaluate the incidence of acute abdomen in renal transplant recipients observed to the emergency departments of not referral transplantation centers. Clinical and demographic findings regarding 14 patients who experienced acute abdomen between February 2005 and Dicember 2008 have been collected. The following data was investigated: etiology, diagnostic workup, duration of symptoms, elapsed time between admission and emergency operation if performed, morbility and mortality. The severity of disease at presentation was assessed by mean of the Acute Physiology and Chronic Health Evaluation score (APACHE II). Acute abdomen was due to pancreatitis in three patients (23.1%); to cholecystitis in three (23.1%); to acute diverticolitis with colon perforation in two patients (15.4%); to acute appendicitis in two (15.4%) and to intestinal obstruction in 2 patients (15.4%). Small bowel perforation was observed in two patients (15.4%) which one case, upon pathological examination, showed malignant lymphoma. The mean APACHE II score was 14.0 ± 5.9. Ten patients (71.4%) were submitted to surgery. Overall mortality and morbidity were 35% and 42% respectively. Statistical analysis showed admission APACHE II score (p<0.01), duration of symptoms (p<0.05), and total time elapsed between the onset of symptoms and treatment (p<0.04) as factors significantly related to mortality.


Subject(s)
Abdomen, Acute/epidemiology , Abdomen, Acute/surgery , Intensive Care Units , Kidney Transplantation , APACHE , Abdomen, Acute/diagnosis , Abdomen, Acute/etiology , Abdomen, Acute/mortality , Adult , Aged , Female , Gastrointestinal Diseases/complications , Health Surveys , Humans , Incidence , Italy/epidemiology , Kidney Transplantation/adverse effects , Kidney Transplantation/mortality , Lymphoma/complications , Male , Middle Aged , Referral and Consultation , Retrospective Studies , Risk Factors , Severity of Illness Index , Survival Rate
12.
Neuroscience ; 138(4): 1161-70, 2006.
Article in English | MEDLINE | ID: mdl-16427207

ABSTRACT

Considerable evidence supports the role of oxidative stress in the pathogenesis of Alzheimer's disease. One hallmark of Alzheimer's disease is the accumulation of amyloid beta-peptide, which invokes a cascade of oxidative damage to neurons that can eventually result in neuronal death. Amyloid beta-peptide is the main component of senile plaques and generates free radicals ultimately leading to neuronal damage of membrane lipids, proteins and nucleic acids. Therefore, interest in the protective role of different antioxidant compounds has been growing for treatment of Alzheimer's disease and other oxidative stress-related disorders. Among different antioxidant drugs, much interest has been devoted to "thiol-delivering" compounds. Tricyclodecan-9-yl-xanthogenate is an inhibitor of phosphatidylcholine specific phospholipase C, and recent studies reported its ability to act as a glutathione-mimetic compound. In the present study, we investigate the in vivo ability of tricyclodecan-9-yl-xanthogenate to protect synaptosomes against amyloid beta-peptide-induced oxidative stress. Gerbils were injected i.p. with tricyclodecan-9-yl-xanthogenate or with saline solution, and synaptosomes were isolated from the brain. Synaptosomal preparations isolated from tricyclodecan-9-yl-xanthogenate injected gerbils and treated ex vivo with amyloid beta-peptide (1-42) showed a significant decrease of oxidative stress parameters: reactive oxygen species levels, protein oxidation (protein carbonyl and 3-nitrotyrosine levels) and lipid peroxidation (4-hydroxy-2-nonenal levels). Our results are consistent with the hypothesis that modulation of free radicals generated by amyloid beta-peptide might represent an efficient therapeutic strategy for treatment of Alzheimer's disease and other oxidative-stress related disorders. Based on the above data, we suggest that tricyclodecan-9-yl-xanthogenate is a potent antioxidant and could be of importance for the treatment of Alzheimer's disease and other oxidative stress-related disorders.


Subject(s)
Alzheimer Disease/drug therapy , Amyloid beta-Peptides/antagonists & inhibitors , Bridged-Ring Compounds/pharmacology , Nerve Degeneration/drug therapy , Oxidative Stress/drug effects , Peptide Fragments/antagonists & inhibitors , Thiones/pharmacology , Aldehydes/antagonists & inhibitors , Aldehydes/metabolism , Alzheimer Disease/metabolism , Alzheimer Disease/physiopathology , Amyloid beta-Peptides/toxicity , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , Brain/drug effects , Brain/metabolism , Bridged-Ring Compounds/therapeutic use , Disease Models, Animal , Free Radicals/antagonists & inhibitors , Free Radicals/metabolism , Gerbillinae , Lipid Peroxidation/drug effects , Lipid Peroxidation/physiology , Male , Nerve Degeneration/metabolism , Nerve Degeneration/physiopathology , Neurons/drug effects , Neurons/metabolism , Norbornanes , Oxidative Stress/physiology , Peptide Fragments/toxicity , Reactive Oxygen Species/antagonists & inhibitors , Reactive Oxygen Species/metabolism , Synaptosomes , Thiocarbamates , Thiones/therapeutic use , Type C Phospholipases/antagonists & inhibitors , Type C Phospholipases/metabolism , Tyrosine/analogs & derivatives , Tyrosine/antagonists & inhibitors , Tyrosine/metabolism
14.
Placenta ; 23 Suppl A: S58-68, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11978060

ABSTRACT

During pregnancy, changes in oxygen tension are essential for proper embryonic and placental development. Little is known about the mechanisms underlying mammalian cellular adaptations to changes in oxygen tension. Currently, we have explored putative mechanisms by which human trophoblast cells may sense oxygen. In order to investigate a role for hemoproteins in oxygen sensing, we cultured human villous explants of 5-8 weeks gestation under 20 per cent O(2) in the presence of either cobalt chloride or desferrioxamine, which interfere with the ability of iron (heme) to interact with oxygen. Treatment with these compounds mimicked hypoxia by stimulating the low oxygen effect on extravillous trophoblast outgrowth (EVT) and inducing HIF-1alpha expression, analogous to that observed in explants cultured at 3 per cent O(2). Addition of unhindered iron, in the form of iron chloride, to the treated-explants reversed the stimulatory effect on EVT outgrowth and HIF-1alpha expression. Subsequently, in order to probe into a mitochondrial role in trophoblast oxygen sensing, we cultured first trimester villous explants under 3 per cent O(2) in the presence of either diphenyleneiodonium or rotenone, known inhibitors of flavin-containing proteins. Treated-explants showed inhibition of the typical low oxygen-induced EVT outgrowth, when compared to untreated controls. Thus, this data supports a hypothesis that trophoblast cells may utilize mitochondria and/or hemoproteins as oxygen sensors to detect the critical changes in oxygen tension during pregnancy.


Subject(s)
Oxygen Consumption/physiology , Oxygen/metabolism , Trophoblasts/metabolism , Adult , Chorionic Villi/drug effects , Chorionic Villi/physiology , Cobalt/pharmacology , Deferoxamine/pharmacology , Drug Combinations , Enzyme Inhibitors/pharmacology , Female , Ferrous Compounds/pharmacology , Hemeproteins/metabolism , Humans , Hypoxia/chemically induced , Hypoxia/physiopathology , Iron Chelating Agents/pharmacology , Mitochondria/drug effects , Mitochondria/enzymology , Onium Compounds/pharmacology , Organ Culture Techniques , Oxygen/pharmacology , Pregnancy , Pregnancy Trimester, First , Rotenone/pharmacology , Trophoblasts/drug effects , Uncoupling Agents/pharmacology
15.
Eur J Cancer ; 37(15): 1953-62, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11576853

ABSTRACT

The cytotoxic activity of the imidazoacridinone C1311 was assessed on two ovarian cancer cell lines (A2780, OAW42) and one osteogenic sarcoma cell line (U2-OS) and their sublines (A2780Cp8, OAW42-MER and U2-OS-R) with experimentally induced resistance to cisplatin. A 1-h exposure to C1311 significantly inhibited the growth of all cell lines, with IC50 values ranging from 0.50 +/-0.11 to 4.10+/-0.36 microM. No or only partial cross-resistance was found between C1311 and cisplatin in the different cell lines. Treatment with equitoxic (IC50) C1311 concentrations consistently induced accumulation of cells in the G2M phase. The cyclin B1-associated p34(cdc2) kinase activity in cells arrested in G2M was superimposable to that of control cells in the OAW42-MER and U2-OS cell lines, whereas a reduction of cdc2 catalytic activity was observed in OAW42 and U2-OS-R cells. Exposure to C1311 (IC50) induced apoptosis in the U2-OS and U2-OS-R cell lines, whereas in the OAW42 and OAW42-MER cell lines there was a negligible percentage of apoptotic cells. In U2-OS, U2-OS-R and OAW42 cells, C1311 induced an increase in p53 expression and an increase in p21waf1 protein, whereas p53 failed to transactivate p21waf1 in OAW42-MER cells. An almost complete abrogation of bcl-2 was observed in U2-OS-R cells in correspondence with the peak of apoptosis induction. Our results indicate that C1311 is active against human ovarian cancer and osteogenic sarcoma cells and is not cross-resistant with CDDP. Moreover, C1311 blocks cells in the G2M phase and induces apoptosis in a small percentage of osteogenic sarcoma cells.


Subject(s)
Aminoacridines/pharmacology , Antineoplastic Agents/pharmacology , Bone Neoplasms/pathology , Cell Cycle/drug effects , Osteosarcoma/pathology , Ovarian Neoplasms/pathology , Apoptosis/drug effects , Cell Division/drug effects , Cyclin B/drug effects , Cyclin B/metabolism , Cyclin B1 , Dose-Response Relationship, Drug , Female , G2 Phase/drug effects , Humans , Tumor Cells, Cultured
16.
Biochim Biophys Acta ; 1525(1-2): 43-9, 2001 Feb 16.
Article in English | MEDLINE | ID: mdl-11342252

ABSTRACT

The oxidation of opioid peptides by tyrosinase in the presence of an excess of a thiol gives rise to cysteinyldopa derivatives. The major products arising from the reaction between Leu-enkephalin and cysteine are represented by 5-S-cysteinyldopaenkephalin (5-CDenk) and 2-S-cysteinyldopaenkephalin (2-CDenk). The interaction of 5-CDenk and 2-CDenk with reactive oxygen species (ROS) has been studied. These compounds are able to scavenge superoxide anion, hydroxyl and peroxyl radicals as well as to reduce the lipid peroxidation rate induced by ABAP. The scavenging activities in all instances are dose-dependent. In some cases CDenks are more active than compounds recognized as strong radical scavengers, such as Trolox and mannitol. As a result of the action of the Fenton system, the CDenks (as well as the Enks) are oxidized into pigmented derivatives. The possible implications of the interaction of CDenks and Enks with ROS on melanization process in Parkinson's disease are discussed.


Subject(s)
Enkephalins/metabolism , Reactive Oxygen Species/metabolism , Animals , Enkephalins/chemistry , Free Radical Scavengers/metabolism , Humans , Hydroxyl Radical/metabolism , In Vitro Techniques , Lipid Peroxidation , Melanins/biosynthesis , Oxidation-Reduction , Parkinson Disease/metabolism , Peroxides/metabolism , Superoxides/metabolism
17.
Eur J Cancer ; 36(16): 2137-45, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11044653

ABSTRACT

In tumour cells, replicative immortality is attained through stabilisation of telomeres by telomerase. Recent evidence suggests that telomerase plays an anti-apoptotic role. Since apoptosis is the primary mode of cell death induced by several drugs, telomerase could be involved in determining the chemosensitivity profile of tumour cells. We investigated whether inhibition of telomerase activity through a hammerhead ribozyme targeting the RNA template of telomerase influences the susceptibility of human melanoma cells to a variety of anticancer agents (platinum compounds, taxanes, topoisomerase I inhibitors). The ribozyme sequence was inserted into an expression vector and the JR8 human melanoma cell line was transfected with it. The cell clones obtained showed a reduced telomerase activity. Growth inhibition curves generated after exposure of ribozyme-transfectant clones to individual drugs were superimposable to those obtained from parental cells. Moreover, telomerase inhibition did not promote apoptosis as a cellular response to drug treatment. Overall, our results indicate that downregulation of telomerase activity does not increase the sensitivity of melanoma cells to anticancer drugs.


Subject(s)
Antineoplastic Agents/therapeutic use , Melanoma/drug therapy , Melanoma/enzymology , Neoplasm Proteins/antagonists & inhibitors , Telomerase/antagonists & inhibitors , Antineoplastic Agents/metabolism , Apoptosis/drug effects , Dose-Response Relationship, Drug , Humans , Melanoma/pathology , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured/drug effects
18.
J Agric Food Chem ; 48(2): 297-301, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10691631

ABSTRACT

A new spectrophotometric assay for the determination of the polyphenolic content of olive oil is presented. It is a substrate-recycling assay for phenolic compounds that employs tyrosinase in the presence of excess NADH. The reaction of various phenols with the enzyme produces an o-quinone, which is detected by recycling between reactions with the enzyme and NADH. The method offers some advantages over the classical methods employed to determine the polyphenolic content of olive oil, that is, ease and reproducibility of the analysis, highly increased sensitivity, and selectivity toward phenolic compounds. The amount of total polyphenols was determined in virgin olive oils both with the Folin-Ciocalteu reagent and with the proposed enzymatic method. The results suggest a better estimation of the polyphenol content, as compared with the colorimetric method. This has to be attributed to the different reactivities of the two methods toward phenols and catechols. Finally, the enzymatic method demonstrates that there is a linear relationship between the olive oil phenolic content and the antioxidative capacity of oil extracts.


Subject(s)
Flavonoids , Phenols/analysis , Plant Oils/chemistry , Polymers/analysis , Monophenol Monooxygenase/metabolism , NAD , Olive Oil , Polyphenols , Spectrophotometry/methods
19.
Melanoma Res ; 9(5): 457-63, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10596912

ABSTRACT

The ability of human recombinant interferon-alpha2a (IFNalpha2a) to induce the expression of cyclin-dependent kinase inhibitors p21waf1 and p27kip1 consequent to signal transducers and activators of transcription (STAT) protein activation was investigated in six human melanoma cell lines with different susceptibilities to the antiproliferative effect of the cytokine. All the cell lines expressed IFNalpha and IFNalpha/beta receptors. Exposure for 24 h to IFNalpha2a markedly enhanced the nuclear expression of STAT1 and STAT2 proteins in all the cell lines. However, no induction of p21waf1 or p27kip1 was consistently observed. Overall, results from the study suggest that the induction of such cyclin-dependent kinase inhibitors is not a major mechanism for the antiproliferative effect of IFNalpha2a, at least in human melanoma cell lines.


Subject(s)
Cell Cycle Proteins , Cyclins/biosynthesis , Interferon-alpha/pharmacology , Melanoma/metabolism , Microtubule-Associated Proteins/biosynthesis , Tumor Suppressor Proteins , Blotting, Western , Cell Division/drug effects , Cell Nucleus/metabolism , Cell Survival/drug effects , Cyclin-Dependent Kinase Inhibitor p21 , Cyclin-Dependent Kinase Inhibitor p27 , DNA-Binding Proteins/biosynthesis , Dose-Response Relationship, Drug , Flow Cytometry , Humans , Interferon alpha-2 , Melanoma/pathology , Receptor, Interferon alpha-beta , Receptors, Interferon/biosynthesis , Recombinant Proteins , STAT1 Transcription Factor , STAT2 Transcription Factor , Time Factors , Trans-Activators/biosynthesis , Tumor Cells, Cultured
20.
Arch Biochem Biophys ; 371(1): 63-9, 1999 Nov 01.
Article in English | MEDLINE | ID: mdl-10525290

ABSTRACT

Recently our group synthesized a new class of melanins obtained by the tyrosinase-catalyzed oxidation of opioid peptides (opiomelanins). Owing to the presence of the peptide moiety such pigments exhibit high solubility in hydrophilic solvents, which allows spectroscopic investigations. In particular, the absence of solid-state quenching effects enables the study of melanin fluorescence properties, till now poorly investigated due to the complete insolubility of melanins produced from tyrosine or Dopa. Opiomelanins dissolved in aqueous medium show a characteristic emission peaked at 440 and 520 nm when excited around 330 nm, where a maximum is observed in the absorption spectrum. Kinetic measurements performed on the tyrosinase-catalyzed oxidation of opioid peptides show that the 440-nm fluorescence band arises in the early stages of peptide oxidation, whereas the 520-nm band appears in later stages of oxidation, i.e., during the polymerization of indole-quinone units. Moreover, molecular sieve fractionation shows that in the opiomelanin fraction with a molecular weight lower than 10 kDa the 440-nm band is dominant in the fluorescence spectrum. The breakdown of the polymer induced by hydrogen peroxide and light (i.e., the photobleaching of melanin pigments) produces a marked enhancement of the 440-nm fluorescence band while the 520-nm band disappears. Hence, our findings suggest that the observed fluorescence contains contributions from both oligomeric units (440-nm band) and high-molecular-weight polymers (520-nm band).


Subject(s)
Melanins/chemistry , Opioid Peptides/chemistry , Agaricales/enzymology , Kinetics , Models, Molecular , Molecular Conformation , Molecular Structure , Monophenol Monooxygenase/metabolism , Spectrometry, Fluorescence/methods
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