Publications by authors named "Viviana Giannuzzi"

19 Publications

  • Page 1 of 1

Ethical and procedural issues for applying researcher-driven multi-national paediatric clinical trials in and outside the European Union: the challenging experience of the DEEP project.

BMC Med Ethics 2021 Apr 29;22(1):49. Epub 2021 Apr 29.

Fondazione per la Ricerca Farmacologica Gianni Benzi Onlus, Via Abate Eustasio, 30, 70010, Valenzano, Italy.

Background: We describe our experience from a multi-national application of a European Union-funded research-driven paediatric trial (DEEP-2, EudraCT 2012-000353-31; NCT01825512). This paper aims to evaluate the impact of the local and national rules on the trial authorisation process in European and non-European countries. National/local provisions and procedures, number of Ethics Committees and Competent Authorities to be addressed, documentation required, special provisions for the paediatric population, timelines for completing the authorisation process and queries received were collected; compliance with the European provisions were evaluated. Descriptive analysis, Wilcoxon Rank-Sum test and General Linear Model analysis were used to determine factors potentially influencing the timelines. The Cluster Analysis procedure was used to identify homogenous groups of cases.

Result: The authorisation process was completed in 7.7 to 53.8 months in European countries and in 17.1 to 27.1 months in non-European countries. The main factors influencing these timelines were the requests for changes/clarifications in European countries and the different national legislations in non-European countries.

Conclusion: This work confirms that the procedures and requirements for the clinical trial application of a paediatric trial are different. In the European Union, the timeframes for submission were generally harmonised but longer. In non-European countries, delays were caused by national dispositions but the entire authorisation process resulted faster with less requests from ECs/CAs. The upcoming application of Regulation (EU) 536/2014 is expected to harmonise practices in Europe and possibly outside. Networks on paediatric research acting at international level will be crucial in this effort.
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http://dx.doi.org/10.1186/s12910-021-00618-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8086274PMC
April 2021

Ethical, Legal and Regulatory Issues of Paediatric Translational Research. Call for an Adequate Model of Governance.

Eur J Health Law 2020 May 18;27(3):213-231. Epub 2020 May 18.

Fondazione per la Ricerca Farmacologica Gianni Benzi onlus Bari Italy.

The lack of paediatric medicines, including innovative and advanced ones, is a long-lasting and well-known problem at European and international levels. Despite the existing legal frameworks and incentives, children remain deprived of many kinds of therapy because of challenges faced in appropriately study and tailoring medicinal and other products for them. In this context, the necessity to foster paediatric research addressing unsolved and uncovered issues within a 'translational approach' has appeared. This article, after having clarified the concept of translational research in the perspective of the establishment of a European paediatric research infrastructure (RI), will identify and point out ethical, legal and regulatory issues particularly relevant in a children's rights perspective. It concludes asking for the setting up of an adequate model of governance within a future RI, including adequate and independent ethical oversight and a pluridisciplinary common service dealing with ethical, legal and societal issues relevant for children.
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http://dx.doi.org/10.1163/15718093-BJA10010DOI Listing
May 2020

Machine Learning Systems Applied to Health Data and System.

Eur J Health Law 2020 May 19;27(3):242-258. Epub 2020 May 19.

Fondazione per la Ricerca Farmacologica Gianni Benzi Onlus Bari Italy.

The use of machine learning (ML) in medicine is becoming increasingly fundamental to analyse complex problems by discovering associations among different types of information and to generate knowledge for medical decision support. Many regulatory and ethical issues should be considered. Some relevant EU provisions, such as the General Data Protection Regulation, are applicable. However, the regulatory framework for developing and marketing a new health technology implementing ML may be quite complex. Other issues include the legal liability and the attribution of negligence in case of errors. Some of the above-mentioned concerns could be, at least partially, resolved in case the ML software is classified as a 'medical device', a category covered by EU/national provisions. Concluding, the challenge is to understand how sustainable is the regulatory system in relation to the ML innovation and how legal procedures should be revised in order to adapt them to the current regulatory framework.
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http://dx.doi.org/10.1163/15718093-BJA10009DOI Listing
May 2020

Paediatric Medicines in Europe: The Paediatric Regulation-Is It Time for Reform?

Front Med (Lausanne) 2021 2;8:593281. Epub 2021 Feb 2.

Fondazione per la Ricerca Farmacologica "Gianni Benzi" Onlus, Bari, Italy.

In this paper, we investigated the effects of the European Paediatric Regulation (EC) N° 1901/2006 with respect to satisfying the paediatric therapeutic needs, assessed in terms of the increased number of paediatric medicinal products, new therapeutic indications in specific high-need conditions (neonates, oncology, rare disease, etc.) and increased number of paediatric clinical studies supporting the marketing authorisation. We analysed the paediatric medicinal products approved by the European Medicines Agency in the period January 2007-December 2019, by collecting the following data: year of approval, active substance, legal basis for the marketing authorisation, type of medicinal product (i.e., chemical, biological, or ATMP), orphan drug status, paediatric indication, Anatomical Therapeutic Chemical code (first-level), number and type of paediatric studies. Data were compared with similar data collected in the period 1996-2006. In the period January 1996-December 2019, in a total of 1,190 medicinal products and 843 active substances, 34 and 38%, respectively, were paediatric. In the two periods, before and after the Paediatric Regulation implementation, the paediatric/total medicinal products ratio was constant while the paediatric/total active substances ratio decreased. Moreover, excluding generics and biosimilars, a total of 106 and were granted a in the two periods; out of 175, 128 paediatric medicines had an approved Paediatric Investigational Plan. The remaining 47 were approved without an approved Paediatric Investigational Plan, following the provisions of Directive 2001/83/EC and repurposing an drug. The analysis of the clinical studies revealed that drugs with a Paediatric Investigational Plan were supported by 3.5 studies/drug while drugs without a Paediatric Investigational Plan were supported by only 1.6 studies/drug. This report confirms that the expectations of the European Paediatric Regulation (EC) N° 1901/2006 have been mainly satisfied. However, the reasons for the limited development of paediatric medicines in Europe, should be further discussed, taking advantage of recent initiatives in the regulatory field, such as the Action Plan on Paediatrics, and the open consultation on EU Pharmaceutical Strategy.
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http://dx.doi.org/10.3389/fmed.2021.593281DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7884470PMC
February 2021

Failures to further developing orphan medicinal products after designation granted in Europe: an analysis of marketing authorisation failures and abandoned drugs.

BMJ Open 2017 Sep 11;7(9):e017358. Epub 2017 Sep 11.

Fondazione per la Ricerca Farmacologica Gianni Benzi onlus, Valenzano, Italy.

Objectives: The research and development process in the field of rare diseases is characterised by many well-known difficulties, and a large percentage of orphan medicinal products do not reach the marketing approval.This work aims at identifying orphan medicinal products that failed the developmental process and investigating reasons for and possible factors influencing failures.

Design: Drugs designated in Europe under Regulation (European Commission) 141/2000 in the period 2000-2012 were investigated in terms of the following failures: (1) marketing authorisation failures (refused or withdrawn) and (2) drugs abandoned by sponsors during development.Possible risk factors for failure were analysed using statistically validated methods.

Results: This study points out that 437 out of 788 designations are still under development, while 219 failed the developmental process. Among the latter, 34 failed the marketing authorisation process and 185 were abandoned during the developmental process. In the first group of drugs (marketing authorisation failures), 50% reached phase II, 47% reached phase III and 3% reached phase I, while in the second group (abandoned drugs), the majority of orphan medicinal products apparently never started the development process, since no data on 48.1% of them were published and the 3.2% did not progress beyond the non-clinical stage.The reasons for failures of marketing authorisation were: efficacy/safety issues (26), insufficient data (12), quality issues (7), regulatory issues on trials (4) and commercial reasons (1). The main causes for abandoned drugs were efficacy/safety issues (reported in 54 cases), inactive companies (25.4%), change of company strategy (8.1%) and drug competition (10.8%). No information concerning reasons for failure was available for 23.2% of the analysed products.

Conclusions: This analysis shows that failures occurred in 27.8% of all designations granted in Europe, the main reasons being safety and efficacy issues. Moreover, the stage of development reached by drugs represents a specific risk factor for failures.
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http://dx.doi.org/10.1136/bmjopen-2017-017358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595174PMC
September 2017

The CLOSED trial; CLOnidine compared with midazolam for SEDation of paediatric patients in the intensive care unit: study protocol for a multicentre randomised controlled trial.

BMJ Open 2017 06 21;7(6):e016031. Epub 2017 Jun 21.

Intensive Care and Department of Pediatric Surgery, Erasmus MC-Sophia Children’s Hospital, Rotterdam, The Netherlands.

Introduction: Sedation is an essential part of paediatric critical care. Midazolam, often in combination with opioids, is the current gold standard drug. However, as it is a far-from-ideal agent, clonidine is increasingly being used in children. This drug is prescribed off-label for this indication, as many drugs in paediatrics are. Therefore, the CLOSED trial aims to provide data on the pharmacokinetics, safety and efficacy of clonidine for the sedation of mechanically ventilated patients in order to obtain a paediatric-use marketing authorisation.

Methods And Analysis: The CLOSED study is a multicentre, double-blind, randomised, active-controlled non-inferiority trial with a 1:1 randomisation between clonidine and midazolam. Both treatment groups are stratified according to age in three groups with the same size: <28 days (n=100), 28 days to <2 years (n=100) and 2-18 years (n=100). The primary end point is defined as the occurrence of sedation failure within the study period. Secondary end points include a pharmacokinetic/pharmacodynamic relationship, pharmacogenetics, occurrence of delirium and withdrawal syndrome, opioid consumption and neurodevelopment in the neonatal age group. Logistic regression will be used for the primary end point, appropriate statistics will be used for the secondary end points.

Ethics: Written informed consent will be obtained from the parents/caregivers. Verbal or deferred consent will be used in the sites where national legislation allows. The study has institutional review board approval at recruiting sites. The results will be published in a peer-reviewed journal and shared with the worldwide medical community.

Trial Registration: EudraCT: 2014-003582-24; Clinicaltrials.gov: NCT02509273; pre-results.
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http://dx.doi.org/10.1136/bmjopen-2017-016031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5726127PMC
June 2017

Pattern of complications and burden of disease in patients affected by beta thalassemia major.

Curr Med Res Opin 2017 08 7;33(8):1525-1533. Epub 2017 Jun 7.

a Fondazione per la Ricerca Farmacologica Gianni Benzi Onlus , Valenzano ( BA ), Italy.

Objectives: Despite the correct application of blood transfusions and chelation treatments, beta thalassemia patients have many complications. Systematic population analyses on types and frequency of these complications are very few. The aim of this study is to characterize the complications, their risk factors and their clinical and economic impact.

Methods: Complications at baseline and events occurring during one observational year were analyzed in 272 patients aged >12 years. Risk factors were analyzed through chi-squared and unpaired t tests. Logistic regression was applied to perform the risk factors multivariate analysis.

Results: A total of 554 complications (1-6 per patient) affected 82.3% of patients. Cardiac complications were less represented than expected. Musculoskeletal diseases were the most represented complications followed by hepatic, sexual and endocrine diseases. Splenectomized patients, born before 1970 and aged >40 years, starting iron chelation therapy when aged >4 years or after receiving more than 20 blood transfusions, presented a significantly higher number of complications. A total of 885 adverse events requiring 34125 additional medical services occurred in 1 year. Of these, 34.9% were related to treatments and 65.1% to other causes. Event numbers, additional medical interventions and cost increased progressively in patients affected by one or more complication compared to patients with no complications.

Conclusions: The pattern of complications changes according to birth cohort and differentiates older from younger patients. The burden of the disease and its costs increase after the onset of the first complication, therefore prevention of complications is fundamental in these patients.
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http://dx.doi.org/10.1080/03007995.2017.1326890DOI Listing
August 2017

Orphan medicinal products in Europe and United States to cover needs of patients with rare diseases: an increased common effort is to be foreseen.

Orphanet J Rare Dis 2017 04 3;12(1):64. Epub 2017 Apr 3.

Fondazione per la Ricerca Farmacologica Gianni Benzi onlus, Via Abate Eustasio, 30 - 70010, Valenzano, Italy.

Background: In the European Union (EU) and United States (US), specific regulations have been released to provide incentives to develop and sell orphan medicinal products. We analysed the status of orphan drugs designated that not yet received a marketing authorisation or already marketed for patients affected by rare diseases in the EU and US up to December 2015. For each drug, the following data were extracted: designation date, active substance(s), orphan condition and indication, trade name, approved therapeutic indication, approved ages, genetic nature of disease and if affects children.

Results: In the EU, 1264 Orphan Drug Designations have been granted and 133 medicinal products were approved covering a total of 179 indications and 122 rare conditions. Among these, 79 were approved under Regulation (EC)141/2000 (65 still listed in the Orphan Medicinal Products Register and 14 lost the orphan designation but still authorised) and 23 were approved centrally by the European Agency before the Orphan Regulation entered into force. On the other hand, in the US 3082 designations and 415 orphan products, covering a total of 521 indications and 300 rare conditions, were granted. As a result, the mean of designations per year is 79 in the EU and 93.4 in the US, while the mean of approved indications per year is 8.5 in the EU and 15.8 in the US. No orphan product is marketed in the EU for bone and connective tissue, ophthalmic, poisoning/overdose, renal, urinary and reproductive rare diseases. Among the marketed medicinal products, only 46.6% in the EU and 35.2% in the US are approved for children. If all the existing market approvals were merged, 362 additional therapeutic indications in the EU and 72 in the US would be covered.

Conclusions: Our data show that notwithstanding the incentives issued, the number of medicines for rare diseases is still limited, and this is more evident in certain therapeutic areas. However, by merging all the existing approvals, patients would benefit of substantial advantages in both geographic areas. Efforts and cooperation between EU and US seem the only way to speed up the development and marketing of drugs for rare diseases.
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http://dx.doi.org/10.1186/s13023-017-0617-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5376695PMC
April 2017

The ethical framework for performing research with rare inherited neurometabolic disease patients.

Eur J Pediatr 2017 Mar 16;176(3):395-405. Epub 2017 Jan 16.

Fondazione Per la Ricerca Farmacologica Gianni Benzi Onlus, Via Abate Eustasio 30, 70010, Valenzano, BA, Italy.

The need for performing clinical trials to develop well-studied and appropriate medicines for inherited neurometabolic disease patients faces ethical concerns mainly raising from four aspects: the diseases are rare; include young and very young patients; the neurological impairment may compromise the capability to provide 'consent'; and the genetic nature of the disease leads to further ethical implications. This work is intended to identify the ethical provisions applicable to clinical research involving these patients and to evaluate if these cover the ethical issues. Three searches have been performed on the European regulatory/legal framework, the literature and European Union-funded projects. The European legal framework offers a number of ethical provisions ruling the clinical research on paediatric, rare, inherited diseases with neurological symptoms. In the literature, relevant publications deal with informed consent, newborn genetic screenings, gene therapy and rights/interests of research participants. Additional information raised from European projects on sharing patients' data from different countries, the need to fill the gap of the regulatory framework and to improve information to stakeholders and patients/families.

Conclusion: Several recommendations and guidelines on ethical aspects are applicable to the inherited neurometabolic disease research in Europe, even though they suffer from the lack of a common ethical approach. What is Known: • When planning and conducting clinical trials, sponsors and researchers know that clinical trials are to be performed according to well-established ethical rules, and patients should be aware about their rights. • In the cases of paediatric patients, vulnerable patients unable to provide consent, genetic diseases' further rules apply. What is New: • This work discusses which ethical rules apply to ensure protection of patient's rights if all the above-mentioned features coexist. • This work shows available data and information on how these rules have been applied.
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http://dx.doi.org/10.1007/s00431-017-2852-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5321701PMC
March 2017

The Italian multiregional thalassemia registry: Centers characteristics, services, and patients' population.

Hematology 2016 Aug 22;21(7):415-24. Epub 2016 Feb 22.

a Fondazione per la Ricerca Farmacologica Gianni Benzi Onlus , Via Abate Eustasio 30, 70010 Valenzano (BA) , Italy.

Objectives: The prognosis of beta-Thalassemia major and other congenital hemoglobinopathies has profoundly changed over the last decades. Moreover, only few countries in Europe provide dedicated services and the description of the measures for patients monitoring and treatment is overall very scarce. The HTA-Thal project is aimed to identify the services available in Italy and to collect epidemiological and clinical data on the thalassemic population (HTA-Thal Registry).

Methods: A map of the existing centers was created and two electronic questionnaires were completed with information on the services and patients.

Results: On 182 centers identified, 60 completed the two questionnaires. Centers resulted to be extremely heterogeneous in terms of size, age of patients in care, and services availability. The transition of pediatric patients to adult centers was not guaranteed. Thousand eight hundred and seventy-three beta-Thalassemia major patients (of which 259 pediatrics), regularly transfused, were registered. Deferasirox is the most used chelator as monotherapy (616 patients) and its use prevails in younger patients. A higher number of patients (847 patients) use Deferoxamine, either alone (448 patients) or in combination with DFP (399 patients), while 782 patients use Deferiprone alone (383 patients) or in combination (399 patients). 31.6 and 66.6% of centers were not equipped for specialized visits or local MRI, respectively. Centers with 30-80 patients show the high percentage of patients appropriately monitored when compared to smaller or bigger centers.

Conclusions: This analysis confirms the importance of patients' registries for the collection of large datasets and the need for dedicated 'specialized centers' equipped to provide the best standard treatment to patients.
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http://dx.doi.org/10.1080/10245332.2015.1101971DOI Listing
August 2016

Review and evaluation of the methodological quality of the existing guidelines and recommendations for inherited neurometabolic disorders.

Orphanet J Rare Dis 2015 Dec 30;10:164. Epub 2015 Dec 30.

Neurology, gastroenterology pathology and clinical biochemistry Departments, IRP-HSJD and CIBERER, Barcelona, Spain.

Background: Inherited neurometabolic disorders (iNMDs) represent a group of almost seven hundred rare diseases whose common manifestations are clinical neurologic or cognitive symptoms that can appear at any time, in the first months/years of age or even later in adulthood. Early diagnosis and timely treatments are often pivotal for the favorable course of the disease. Thus, the elaboration of new evidence-based recommendations for iNMD diagnosis and management is increasingly requested by health care professionals and patients, even though the methodological quality of existing guidelines is largely unclear. InNerMeD-I-Network is the first European network on iNMDs that was created with the aim of sharing and increasing validated information about diagnosis and management of neurometabolic disorders. One of the goals of the project was to determine the number and the methodological quality of existing guidelines and recommendations for iNMDs.

Methods: We performed a systematic search on PubMed, the National Guideline Clearinghouse (NGC), the Guidelines International Network (G-I-N), the Scottish Intercollegiate Guideline Network (SIGN) and the National Institute for Health and Care Excellence (NICE) to identify all the published guidelines and recommendations for iNMDs from January 2000 to June 2015. The methodological quality of the selected documents was determined using the AGREE II instrument, an appraisal tool composed of 6 domains covering 23 key items.

Results: A total of 55 records met the inclusion criteria, 11 % were about groups of disorders, whereas the majority encompassed only one disorder. Lysosomal disorders, and in particular Fabry, Gaucher disease and mucopolysaccharidoses where the most studied. The overall methodological quality of the recommendation was acceptable and increased over time, with 25 % of the identified guidelines strongly recommended by the appraisers, 64 % recommended, and 11 % not recommended. However, heterogeneity in the obtained scores for each domain was observed among documents covering different groups of disorders and some domains like 'stakeholder involvement' and 'applicability' were generally scarcely addressed.

Conclusions: Greater efforts should be devoted to improve the methodological quality of guidelines and recommendations for iNMDs and AGREE II instrument seems advisable for new guideline development. The elaboration of new guidelines encompassing still uncovered disorders is badly needed.
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http://dx.doi.org/10.1186/s13023-015-0376-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696316PMC
December 2015

Clinical Trial Application in Europe: What Will Change with the New Regulation?

Sci Eng Ethics 2016 Apr 3;22(2):451-66. Epub 2015 Jun 3.

Fondazione per la Ricerca Farmacologica Gianni Benzi onlus, Via Abate Eustasio, 30, 70010, Valenzano, Italy.

The European framework surrounding clinical trials on medicinal products for human use is going to change as demonstrated by the large debate at European institutional level. One of the major challenges is to overcome the lack of harmonisation of clinical trial procedures among countries. This aspect is gaining more and more importance, considering the increasing number of multicentre and multinational studies. In this work, the actual European rules governing the Clinical Trial Application have been analysed throughout the different steps including the registration of the trial in the European database; the preparation of documents to be submitted and their contents; the preparation of documents related to the information and consent process; the submission to competent bodies. Specific issues related to paediatric research and trials involving non EU/EEA countries have been addressed as well. Results reveal that the European legislation offers a well defined set of European rules covering different aspects of a Clinical Trial Application. However, these are not suitable to meet the challenges from multicentre and multinational clinical studies. A stronger set of rules, such as is available in a composite European Regulation has been adopted and is expected to harmonise practices and enable sponsors to carry out well conducted trials. But will the new regulation overcome the existing criticisms of Directive 2001/20/EC?
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http://dx.doi.org/10.1007/s11948-015-9662-0DOI Listing
April 2016

Growth hormone secretagogues exert differential effects on skeletal muscle calcium homeostasis in male rats depending on the peptidyl/nonpeptidyl structure.

Endocrinology 2013 Oct 8;154(10):3764-75. Epub 2013 Jul 8.

Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari, Via Orabona, 4, Campus, I-70125 Bari, Italy.

The orexigenic and anabolic effects induced by ghrelin and the synthetic GH secretagogues (GHSs) are thought to positively contribute to therapeutic approaches and the adjunct treatment of a number of diseases associated with muscle wasting such as cachexia and sarcopenia. However, many questions about the potential utility and safety of GHSs in both therapy and skeletal muscle function remain unanswered. By using fura-2 cytofluorimetric technique, we determined the acute effects of ghrelin, as well as of peptidyl and nonpeptidyl synthetic GHSs on calcium homeostasis, a critical biomarker of muscle function, in isolated tendon-to-tendon male rat skeletal muscle fibers. The synthetic nonpeptidyl GHSs, but not peptidyl ghrelin and hexarelin, were able to significantly increase resting cytosolic calcium [Ca²⁺]i. The nonpeptidyl GHS-induced [Ca²⁺]i increase was independent of GHS-receptor 1a but was antagonized by both thapsigargin/caffeine and cyclosporine A, indicating the involvement of the sarcoplasmic reticulum and mitochondria. Evaluation of the effects of a pseudopeptidyl GHS and a nonpeptidyl antagonist of the GHS-receptor 1a together with a drug-modeling study suggest the conclusion that the lipophilic nonpeptidyl structure of the tested compounds is the key chemical feature crucial for the GHS-induced calcium alterations in the skeletal muscle. Thus, synthetic GHSs can have different effects on skeletal muscle fibers depending on their molecular structures. The calcium homeostasis dysregulation specifically induced by the nonpeptidyl GHSs used in this study could potentially counteract the beneficial effects associated with these drugs in the treatment of muscle wasting of cachexia- or other age-related disorders.
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http://dx.doi.org/10.1210/en.2013-1334DOI Listing
October 2013

Antioxidant treatment of hindlimb-unloaded mouse counteracts fiber type transition but not atrophy of disused muscles.

Pharmacol Res 2010 Jun 29;61(6):553-63. Epub 2010 Jan 29.

Section of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Via Orabona 4 - campus, 70125 Bari, Italy.

Oxidative stress was proposed as a trigger of muscle impairment in various muscle diseases. The hindlimb-unloaded (HU) rodent is a model of disuse inducing atrophy and slow-to-fast transition of postural muscles. Here, mice unloaded for 14 days were chronically treated with the selective antioxidant trolox. After HU, atrophy was more pronounced in the slow-twitch soleus muscle (Sol) than in the fast-twitch gastrocnemius and tibialis anterior muscles, and was absent in extensor digitorum longus muscle. In accord with the phenotype transition, HU Sol showed a reduced expression of myosin heavy chain type 2A (MHC-2A) and increase in MHC-2X and MHC-2B isoforms. In parallel, HU Sol displayed an increased sarcolemma chloride conductance related to an increased expression of ClC-1 channels, changes in excitability parameters, a positive shift of the mechanical threshold, and a decrease of the resting cytosolic calcium concentration. Moreover, the level of lipoperoxidation increased proportionally to the degree of atrophy of each muscle type. As expected, trolox treatment fully prevented oxidative stress in HU mice. Atrophy was not prevented but the drug significantly attenuated Sol phenotypic transition and excitability changes. Trolox treatment had no effect on control mice. These results suggest possible benefits of antioxidants in protecting muscle against disuse.
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http://dx.doi.org/10.1016/j.phrs.2010.01.012DOI Listing
June 2010

Multiple pathological events in exercised dystrophic mdx mice are targeted by pentoxifylline: outcome of a large array of in vivo and ex vivo tests.

J Appl Physiol (1985) 2009 Apr 8;106(4):1311-24. Epub 2009 Jan 8.

Unit of Pharmacology, Department of Pharmaco-biology, Faculty of Pharmacy, University of Bari, Bari, Italy.

The phosphodiesterases inhibitor pentoxifylline gained attention for Duchenne muscular dystrophy therapy for its claimed anti-inflammatory, antioxidant, and antifibrotic action. A recent finding also showed that pentoxifylline counteracts the abnormal overactivity of a voltage-independent calcium channel in myofibers of dystrophic mdx mice. The possible link between workload, altered calcium homeostasis, and oxidative stress pushed toward a more detailed investigation. Thus a 4- to 8-wk treatment with pentoxifylline (50 mg x kg(-1) x day(-1) ip) was performed in mdx mice, undergoing or not a chronic exercise on treadmill. In vivo, the treatment partially increased forelimb strength and enhanced resistance to treadmill running in exercised animals. Ex vivo, pentoxifylline restored the mechanical threshold, an electrophysiological index of calcium homeostasis, and reduced resting cytosolic calcium in extensor digitorum longus muscle fibers. Mn quenching and patch-clamp technique confirmed that this effect was paralleled by a drug-induced reduction of membrane permeability to calcium. The treatment also significantly enhanced isometric tetanic tension in mdx diaphragm. The plasma levels of creatine kinase and reactive oxygen species were both significantly reduced in treated-exercised animals. Dihydroethidium staining, used as an indicator of reactive oxygen species production, showed that pentoxifylline significantly reduced the exercise-induced increase in fluorescence in the mdx tibialis anterior muscle. A significant decrease in connective tissue area and profibrotic cytokine transforming growth factor-beta(1) was solely found in tibialis anterior muscle. In both diaphragm and gastrocnemius muscle, a significant increase in neural cell adhesion molecule-positive area was instead observed. This data supports the interest toward pentoxifylline and allows insight in the level of cross talk between pathogenetic events in workloaded dystrophic muscle.
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http://dx.doi.org/10.1152/japplphysiol.90985.2008DOI Listing
April 2009

Gentamicin treatment in exercised mdx mice: Identification of dystrophin-sensitive pathways and evaluation of efficacy in work-loaded dystrophic muscle.

Neurobiol Dis 2008 Nov 23;32(2):243-53. Epub 2008 Jul 23.

Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Italy.

Aminoglycosides force read through of premature stop codon mutations and introduce new mutation-specific gene-corrective strategies in Duchenne muscular dystrophy. A chronic treatment with gentamicin (32 mg/kg/daily i.p., 8-12 weeks) was performed in exercised mdx mice with the dual aim to clarify the dependence on dystrophin of the functional, biochemical and histological alterations present in dystrophic muscle and to verify the long term efficiency of small molecule gene-corrective strategies in work-loaded dystrophic muscle. The treatment counteracted the exercise-induced impairment of in vivo forelimb strength after 6-8 weeks. We observed an increase in dystrophin expression level in all the fibers, although lower than that observed in normal fibers, and found a concomitant recovery of aquaporin-4 at sarcolemma. A significant reduction in centronucleated fibers, in the area of necrosis and in the percentage of nuclear factor-kB-positive nuclei was observed in gastrocnemious muscle of treated animals. Plasma creatine kinase was reduced by 70%. Ex vivo, gentamicin restored membrane ionic conductance in mdx diaphragm and limb muscle fibers. No effects were observed on the altered calcium homeostasis and sarcolemmal calcium permeability, detected by electrophysiological and microspectrofluorimetric approaches. Thus, the maintenance of a partial level of dystrophin is sufficient to reinforce sarcolemmal stability, reducing leakiness, inflammation and fiber damage, while correction of altered calcium homeostasis needs greater expression of dystrophin or direct interventions on the channels involved.
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http://dx.doi.org/10.1016/j.nbd.2008.07.009DOI Listing
November 2008

Fluvastatin and atorvastatin affect calcium homeostasis of rat skeletal muscle fibers in vivo and in vitro by impairing the sarcoplasmic reticulum/mitochondria Ca2+-release system.

J Pharmacol Exp Ther 2007 May 9;321(2):626-34. Epub 2007 Feb 9.

Section of Pharmacology, Dept. of Pharmacobiology, Faculty of Pharmacy, University of Bari, Via Orabona, 4, I-70125 Bari, Italy.

The mechanism by which the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) induce skeletal muscle injury is still under debate. By using fura-2 cytofluorimetry on intact extensor digitorum longus muscle fibers, here we provided the first evidence that 2 months in vivo chronic treatment of rats with fluvastatin (5 and 20 mg kg-1) and atorvastatin (5 and 10 mg kg-1) caused an alteration of calcium homeostasis. All treated animals showed a significant increase of resting cytosolic calcium [Ca2+]i, up to 60% with the higher fluvastatin dose and up to 20% with the other treatments. The [Ca2+]i rise induced by statin administration was not due to an increase of sarcolemmal permeability to calcium. Furthermore, the treatments reduced caffeine responsiveness. In vitro application of fluvastatin caused changes of [Ca2+]i, resembling the effect obtained after the in vivo administration. Indeed, fluvastatin produced a shift of mechanical threshold for contraction toward negative potentials and an increase of resting [Ca2+]i. By using ruthenium red and cyclosporine A, we determined the sequence of the statin-induced Ca2+ release mechanism. Mitochondria appeared as the cellular structure responsible for the earlier event leading to a subsequent large sarcoplasmic reticulum Ca2+ release. In conclusion, we suggest that calcium homeostasis alteration may be a crucial event for myotoxicity induced by this widely used class of hypolipidemic drugs.
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http://dx.doi.org/10.1124/jpet.106.118331DOI Listing
May 2007

Fiber type-related changes in rat skeletal muscle calcium homeostasis during aging and restoration by growth hormone.

Neurobiol Dis 2006 Feb 8;21(2):372-80. Epub 2005 Sep 8.

Division of Pharmacology, Department of Pharmaco-Biology, Faculty of Pharmacy, University of Bari, Bari I-70125, Italy.

The mechanisms by which aging induces muscle impairment are not well understood yet. We studied the impact of aging on Ca2+ homeostasis in the slow-twitch soleus and the fast-twitch extensor digitorum longus (EDL) muscles of aged rats by using the fura-2 fluorescent probe. In both muscles aging increases the resting cytosolic calcium concentration ([Ca2+]i). This effect was independent on calcium influx since a reduced resting permeability of sarcolemma to divalent cations was observed in aged muscles likely due to a reduced activity of leak channels. Importantly the effects of aging on resting [Ca2+]i, fiber diameter, mechanical threshold and sarcolemmal resting conductances were less pronounced in the soleus muscle, suggesting that muscle impairment may be less dependent on [Ca2+]i in the slow-twitch muscle. The treatment of aged rats with growth hormone restored the resting [Ca2+]i toward adult values in both muscles. Thus, an increase of resting [Ca2+]i may contribute to muscle weakness associated with aging and may be considered for developing new therapeutic strategies in the elderly.
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http://dx.doi.org/10.1016/j.nbd.2005.07.012DOI Listing
February 2006