Leuprolide and triptorelin treatment in children with idiopathic central precocious puberty: an efficacy/tolerability comparison study

Introduction

Central precocious puberty (CPP) results from premature activation of hypothalamic-pituitary-gonadal axis, with the consequent increase of gonadotropin-releasing hormone (GnRH); GnRH agonists (GnRHa) represent the gold-standard therapy in children with CPP although their use might be responsible for pituitary GnRH receptors down-regulation, that in turn suppresses luteinizing hormone (LH) and follicle stimulating hormone (FSH) and blocks of gonadal sex hormones release. The most prescribed GnRHa in the clinical practice are leuprolide and triptorelin, whose use is generally safe and well tolerated; however, mild menopausal-like side effects could appear. The aim of the present study was to investigate and compare the efficacy and tolerability profile of leuprolide and triptorelin in CPP patients.

Methods

110 girls affected by CPP were enrolled in this retrospective study, carried out from 2018 to 2020. The enrolled patients received leuprolide (n = 48) or triptorelin (n = 62). Efficacy was investigated by the means of clinical parameters and radiological changes and side effects were also recorded to evaluate the possible relationship between the two GnRHa treatments and side effects appearance.

Results

At baseline triptorelin patients had significantly higher LH and LH peak levels than leuprolide patients, whereas no significant difference in other patient characteristics was observed between the two groups. The leuprolide treatment lasted 971 days [790-1,171 days] while the duration of triptorelin administration was 792 days [760-1,003 days] (p < 0.001). Overall 46 (41.8%) of the studied patients reported mild menopausal-like symptoms: among these 27 were treated with triptorelin and 19 with leuprolide (p = 0.558). Patients treated with triptorelin, or leuprolide showed headache (27.4% vs. 16.7%), mood swings (12.9% vs. 16.7%), increased appetite (12.9% vs. 18.8%) and nausea (1.6% vs. 10.4%) respectively. Moreover, the onset of side effects appearance related to GnRHa therapy significantly reduces with the increase of the initial bone age (p = 0.038).

Conclusion

Leuprolide and triptorelin treatment appear to be effective and safe without significant difference between the two drugs in term of efficacy and tolerability, making both good options for treating CPP.

Antibacterial activity of nanoparticles and nanomaterials: a possible weapon in the fight against healthcare-associated infections

Healthcare-associated infections are a serious threat in terms of morbidity and mortality for all patients receiving healthcare. The problem is aggravated by the increasingly widespread phenomenon of antibiotic resistance, with some microorganisms now resistant to all or almost all the currently available antibiotics. Nanomaterials are compounds used by many different industrial fields and they are currently studied for their intrinsic antimicrobial properties. To date, many researchers have considered using many different nanoparticles and nanomaterials to produce surfaces and medical devices with intrinsic antimicrobial features. Many compounds have shown very interesting and effective antimicrobial capacities and could be used, in the future, to manufacture new hospital surfaces and medical devices. However, many studies have to be carried out to evaluate the effective potential use of these compounds. The aim of this paper is to review the main literature regarding this topic, focusing on the main types of nanoparticles and nanomaterials studied for this purpose.

COVID-19 and pregnancy: clinical outcomes and scientific evidence about vaccination

Pregnant women and their infants are at high risk to develop a severe COVID-19, with increased rates of hospitalisation to intensive care units, need for mechanical ventilation and mortality. Preterm birth, fetal vascular malperfusion, and premature rupture of membrane have been the most reported adverse pregnancy outcomes and these effects have been especially associated with the onset of the disease at early gestational age. The early expression of ACE2 and TMPRSS2 in human embryos has been proven, determining an increased susceptibility to SARS-CoV-2. Preterm infants born to women infected by SARS-CoV-2 have a higher risk of need for specialist neonatal care with prolonged hospitalization. Moreover, inflammation of developing embryos could cause long-term defects, regardless of vertical transmission of SARS-CoV-2. Due to Maternal Immune Activation (MIA), in utero inflammation is associated with neurodevelopmental, cognitive and psychiatric disorders in affected offspring. Despite risks that COVID-19 could induce in pregnancy, there are not many published data describing the safety and/or efficacy of COVID-19 vaccines in pregnant women, commonly not included in vaccine research. The evidence from the few pregnant women unintentionally enrolled in clinical trials and vaccinated suggests that COVID-19 vaccines, both based on mRNA and viral vectors, do not pose significant risks to the fetus or breastfeeding infants. Moreover, human studies using mRNA-based vaccines against Zika virus, influenza, and rabies have reported good safety and immunogenicity during pregnancy. In this review, we evaluate the role of COVID-19 in adverse pregnancy and neonatal outcomes and the need to vaccinate pregnant women.

The new era of vaccines: the "nanovaccinology"

Vaccinations are the most effective preventive methods against infectious diseases and represent one of the most relevant successes of medicine. Vaccine development is constantly evolving; therefore, the number of vaccine candidates is progressively increasing. However, most of new potential vaccines are characterized by a lower immunogenicity, with the inability to stimulate powerful and long-lasting immune responses. Hence, to get modern and effective vaccines, we need adjuvants and innovative delivery systems that increase their immunogenicity. The use of nanotechnology in vaccinology is providing the opportunity to contrast these difficulties and develop effective vaccines. Particularly, nanoparticles used as vehicles of vaccine components, are able to increase the host's immune responses and, due to their size, to reach specific cellular districts. To date, a certain number of nanovaccines has been approved for human health and many are studied in clinical or pre-clinical trials. There are several types of nanoparticles considered as possible delivers of vaccine antigens. These nanoparticles-based synthetic delivery systems, in the size range of 20-200 nm, protect antigen from degradation, enhance its presentation and facilitate its uptake by professional antigen-presenting cells. Virus-like particles, self-assembled proteins, micelles, liposomes, inorganic nanoparticles, and polymers are the most studied of these systems. In this review, we provide a general overview of different types, methods of synthesis, characterizations, properties and applications of nanoparticles in vaccine production.

Health conditions of migrants landed in north-eastern Sicily and perception of health risks of the resident population

OBJECTIVES

In Italy, a recent irregular movement of people raised concerns among the host population on possible introduction of diseases that have long been controlled in the host countries. This study evaluates the health conditions of illegal immigrants landed on the north-eastern Sicilian territory, to provide information on the clinical and epidemiologic burden of infectious diseases among migrants and how the local population feel about these landings.

STUDY DESIGN

The study design is a cross-sectional study.

METHODS

The study considered all migrants landed illegally in the city of Messina, Sicily, between January 2014 and July 2018. Analysing the data of hospital admissions and disease notifications, we calculated the frequency of infectious diseases among migrant population. Furthermore, through a survey conducted by a well-known online newspaper, we analysed the perception that the local population has about the health risk represented by migrants.

RESULTS

In the considered five-year period, 108 landings, for a total of 38,608 migrants occurred at the Messina port. The percentage of hospitalisation was rather low (3.5%), and it concerned mainly pregnant women. The notifications of infectious diseases were contained, with exception of scabies and tuberculosis. Finally, from the online survey, resulted that there is a large part of local population that considers migrants a potential danger to community health.

CONCLUSIONS

Our data show that the presence of migrants should not have to date any impact on the health conditions of the resident population. However, monitoring over time the health of migrants and screening for infectious diseases as soon as possible after landing are advantageous for both migrants and host country.

The role of the hospital environment in the healthcare-associated infections: a general review of the literature

Healthcare-associated infections (HAIs) are one of the most relevant public health problems worldwide. The role of the hospital environment as a reservoir of pathogens causing HAIs is still debated. These pathogens are common in several hospital environments, where they are able to persist from hours to months and their circulation is favored by healthcare workers (HCWs). Hospital surfaces at close contact with patients such as bed bars and header, bedside table, taps, and handles in wards ("high-touched surfaces"), are considered easily contaminable and at risk to transfer pathogens to patients. However, some studies showed the possible role played by "non-classical" surfaces such as healthcare workers' (HCWs) mobile phones and personal computers as well as oxygen humidifiers and protective lead garments used in operating rooms. HCWs' hands play a fundamental role in patient-to-patient transmission by touching contaminated surfaces or patients during care activities. The aim of this review is to evaluate the role of the hospital environment in the transmission of nosocomial pathogens, focusing on single pathogens causing HAIs and the importance of hospital surfaces as reservoirs.

Today's vaccination policies in Italy: The National Plan for Vaccine Prevention 2017-2019 and the Law 119/2017 on the mandatory vaccinations

The National Plan for Vaccine Prevention 2017-2019 has expanded the vaccination offer including new vaccines, enlarging the target population and introducing for the first time in Italy a life-course approach to vaccination. A "lifetime immunization schedule" is aimed to reduce the burden and the related costs of vaccine-preventable diseases through effective vaccination programs. However, to counteract the national steady downward trend in the uptake of vaccinations that caused a drop of the vaccination coverage below the 95% threshold to allow herd immunity, it was decided to make 10 vaccinations mandatory by the law 119/2017. In particular, in addition to already mandatory vaccinations against diphtheria, tetanus, hepatitis B and poliomyelitis, those against measles, mumps, rubella (MMR), varicella, pertussis and Haemophilus influenzae type b (Hib) were added to the list. According to the law, all unvaccinated children cannot attend preschool services until the age of 6 years and fines (from 100 to 500 Euros) are provided for parents. Moreover, this law provided, in its first application, a catch-up campaign for children up to the age of 16 years and the free-of-charge offer of all mandatory and recommended vaccines to each child not yet vaccinated according to the previous NPVP. The NPVP includes also several at risk categories, such as pregnant women, healthcare workers and subjects suffering from chronic diseases, to whom specific vaccinations, free of charge, are offered. The vaccinations of pregnant women have different purposes. In order to decrease the pertussis risk in newborns in the first months of life, a booster immunization of DTPa is recommended, at every pregnancy, between week 27th and 36th. Instead, the influenza vaccine administration to pregnant women during the second or third quarter is mainly aimed to avoid the risk of serious disease complications for both the mother and the fetus. Another group of at risk subjects included in the NPVP is that made up by healthcare workers. According to the plan, "an adequate immunization of the healthcare workers is essential for the prevention and control of infections (anti-hepatitis B, anti-influenza, anti-measles-mumps-rubella, anti-varicella, anti-pertussis)". Finally, almost all the vaccinations foreseen by the NPVP are offered free of charge to subjects suffering from specific diseases. These include cardiovascular, respiratory, hepatic, neoplastic, renal and metabolic disorders, in addition to immunosuppression that exposes them to an increased risk of contracting invasive infectious diseases.

Hepatitis C-related hepatocellular carcinoma: diagnostic and therapeutic management in HIV-patients

The efficacy of the current HIV therapy has led to increased survival and prolongation of the average life expectancy of people living with HIV (PLWH), as well as the emergence of comorbidities and non-AIDS related cancer. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. Current evidence suggests that HCC is an important cause of morbidity and mortality in HIV infected patients. In fact, HCC prevalence rate is indeed higher with respect to the general population average. In this paper, we review the diagnostic and therapeutic management of Hepatitis C-related hepatocellular carcinoma in HCV-HIV co-infected patients. Several therapeutic options are available depending on several factors as HCC stage, liver functions, comorbidities and they have been divided into three groups: potentially curative, proven effective but not curative, and unproven or ineffective therapy. In HIV-infected patients, surgical options are preferred compared to non-surgical therapies. Further studies, especially multicenter ones, are needed in order to define the most appropriate, evidence-based therapeutic approach to PLWH suffering from HCC. It also appears necessary to develop appropriate care guidelines for PLWH.

Kaposi's sarcoma in HIV-infected patients in the era of new antiretrovirals

Kaposi's Sarcoma (KS) is a multicentric angioproliferative cancer of endothelial cells (ECs) caused by Human Herpesvirus 8 (HHV8) characterized by clinical heterogeneity depending on the host immune conditions. Despite its incidence has dramatically decreased in developed countries after the introduction of Highly Active Antiretroviral Therapy (HAART), KS remains the most frequent tumor in HIV-infected patients worldwide. Clinical presentation varies from an indolent slowly progressive behavior, generally limited to the skin, to an aggressive and rapidly progressing disease. In more than 50% of cases, the skin lesions are often associated with a more or less important visceral involvement, particularly to the oral cavity and the gastrointestinal tract that are involved in 35% and 40% of cases respectively. A large number of treatments can be used both as local and as systemic therapy. Particularly, HAART represents the first treatment in patients with moderate lesions limited to skin, and it can be sufficient to reduce significantly the size of lesions and, often, the complete disappear in 35% of cases after 3-9 months of treatment. In case of a rapidly progressive disease with extensive cutaneous and/or visceral involvement systemic drugs are used such as the liposomal anthracyclines pegylated liposomal doxorubicin (PLD) and daunorubicin citrate liposome (DNX), the combined treatment adriamycin-bleomycin-vincristine (ABV) and bleomycin-vincristine (BV), Paclitaxel and Interferon-alfa. In patients with limited skin localization, the local treatment can play an important role. Local medical therapy is based on the use of alitretinoin, antineoplastic drugs vincristine, vinblastine and bleomycin and Sodium Tetradecyl Sulfate (STS). In addition to medical therapy, physical treatment, such as cryotherapy and radiotherapy, are also commonly used.

GSTP1 gene methylation and AHR rs2066853 variant predict resistance to first generation somatostatin analogs in patients with acromegaly

PURPOSE

Biomarkers of clinical and therapeutic outcome in acromegaly are needed. Polymorphisms or epigenetic changes of detoxification genes, such as those coding for the aryl hydrocarbon receptor (AHR) and the glutathione-S-transferase-P1 (GSTP1), could have a role in GH secreting pituitary tumors' pathophysiology and clinical expression. In this study, we assessed the contribution of GSTP1 gene promoter methylation status, per se or in combination with the occurrence of the AHR gene rs2066853 variant, on clinical features and response to somatostatin analogs (SSA) treatment in acromegaly patients.

METHODS

This is an observational, retrospective study, carried out in the Endocrine Unit of an Italian University Hospital. We enrolled 77 wild-type AIP gene acromegaly patients, who have been screened for germline AHR rs2066853 variant and GSTP1 gene promoter methylation. Clinical and biochemical parameters were compared after patients' stratification according to GSTP1 methylation status and the presence of AHR rs2066853. We also evaluated the response to SSA treatment in 71 cases.

RESULTS

17 patients carried the AHR rs2066853 variant and 26 had methylated GSTP1 (GSTP1-methyl) gene promoter. GSTP1-methyl patients showed a higher prevalence of diabetes mellitus (p = 0.01), colonic polyps (p = 0.05), and were more resistant to SSA (p = 0.02) as compared to GSTP1 unmethylated patients (GSTP1-unmethyl). Patients GSTP1-unmethyl and AHR wild-type were the most sensitive to SSA treatment, while those with both GSTP1-methyl and AHR rs2066853 variant were all resistant to SSA (p = 0.01).

CONCLUSIONS

In acromegaly, GSTP1 gene methylation associates with resistance to SSA treatment, especially in patients carrying also the AHR rs2066853 variant, and with increased prevalence of colonic polyps and diabetes mellitus.

Herpes zoster vaccine: a protection for the elderly

The Herpes Zoster vaccine is strongly recommended by the World Health Organization to promote healthy aging by preventing the corresponding age- related disease, also named shingles. The disease is due to the endogenous reactivation of Varicella Zoster Virus, the causal agent of chickenpox, that becomes latent at the peripheral nervous system level. Here, owing to the host's cell-mediated immunity, it may be confined for several decades. However, the immune senescence allows the possibility of virus reactivation, causing the onset of neuropathic pain and skin rash that characterize the acute disease. Sometimes, the neuralgia becomes chronic causing postherpetic neuralgia that has a significant impact on the quality of patient life, analogously to the ophthalmic HZ, a particularly feared form of disease. Due to the causal relationship between decreasing immune defenses and virus reactivation with disease onset, the incidence of Herpes Zoster, in Italy now equal to 6.42 (95%CI: 5.93-6.95) cases per 1,000 people per year will increase steadily in the future due to the longevity rise of the population. Considering epidemiological impact, complications and sequelae in the short- and long-term, costs of clinical-therapeutical management of patients, and, above all, the poor effectiveness of available therapy the only effective intervention is vaccination of the elderly. Currently in the European Union, there is only one vaccine for Herpes Zoster prevention, formed by live attenuated OKA-Merck virus strain that is also used for paediatric vaccine. According to the Health Technology Assessment surveys, the intervention cost (based on "Quality Adjusted Life Years") is clearly below the discriminating threshold value to judge the feasibility and, as predicted by the Italian National Plan of Vaccinal Prevention 2017-2019, the vaccine is offered free to all subjects >65 years.

Measles outbreak from February to August 2017 in Messina, Italy

Introduction

Measles continues to be a major public health issue worldwide, with high morbidity and mortality rates. The disease remains endemic in 14 European countries, including Italy where, from 2013 to 2016, over 5,000 cases have been reported. In 2017, many Italian regions, including Sicily, have reported many cases of measles. In this study, we described the latest measles outbreak in the city of Messina, from 1^st February to 31^st August 2017.

Methods

We considered all reported measles cases that came to the "Public Health, Epidemiology and Preventive Medicine" Operative Unit of the Messina Provincial Health Agency Prevention Department, which receives all reported cases of measles in the Messina province.

Results

From 1^st February to 31^st August 2017, a total of 59 measles cases were reported, of which 44 were confirmed, nine were classified as possible, four were probable and two cases were discarded. Of the 57 possible, probable and confirmed cases, 31 (54%) were males and 26 (46%) were females. Moreover, 54 (95%) had not been previously vaccinated while the remaining cases had documented evidence of one (two cases) or two doses (one case). Genotype B3 was identified in 39/44 cases (88,6%) by the regional reference laboratory in Palermo.

Conclusions

Despite the development of an effective vaccination, unfortunately measles continues to threaten the lives of millions of children worldwide each year. The suboptimal immunization level in Italy has led to an increase in the transmission of measles with detrimental effects on both public health and ongoing measles elimination efforts.

Serum interleukin-6 levels are increased in HIV-infected patients that develop autoimmune disease during long-term follow-up

BACKGROUND

Elevated IL-6 levels have been associated with both autoimmune diseases and treated HIV-seropositive (HIV⁺) subjects. However, few data on classic and trans-signaling IL-6 in autoimmune thyroid diseases and HIV⁺ subjects developing autoimmune disorders are currently available.

MATERIALS AND METHODS

A total of 102 patients were included in the study. They were subdivided into two groups. Group A consisted in 51 HIV⁺ patients, who were followed-up for a period of five years in search of possible occurrence of autoimmune diseases. Ten of them, treated with antiretroviral therapy (ART), developed an autoimmune disorder, namely Hashimoto's thyroiditis, and psoriasis. Group B consisted in 51 patients affected by Hashimoto's thyroiditis (HT). Serum levels of the free form of IL-6 were analyzed by ELISA in all patients and for HIV⁺ patients at the beginning of the follow-up, before initiation of ART.

RESULTS

Mean serum levels of IL-6 were similar in Group A and in Group B. In Group B, IL-6 levels showed a 5.8% increase compared with assay minimum detectable dose corresponding to 1% of full serum IL-6 level. However, serum levels of free IL-6 were increased in those HIV⁺ patients who developed autoimmune disorders (5.8±2.8pg/ml) and in these patients, the highest levels of free IL-6 correlated with age and CD4 cellular counts.

CONCLUSIONS

The present study indicates a correlation between serum free IL-6 levels and the occurrence of autoimmune disease in HIV⁺ population, treated with ART during a long-term follow-up. The increased levels of serum free IL-6 were observed before ART treatment was initiated, indicating that IL-6 measurement in such patients may represent an early predictor of development of autoimmune disease.

Epidemiological HIV infection surveillance among subjects with risk behaviours in the city of Messina (Sicily) from 1992 to 2015

INTRODUCTION

Epidemiological studies are a key element in determining the evolution and spread of HIV infection among the world population. Knowledge of the epidemiological dynamics improves strategies for prevention and monitoring.

METHODS

We examined 2,272 subjects who voluntarily underwent HIV testing from January 1992 to December 2015. For each subject, an anonymous form was completed to obtain information on personal data, sexual habits and exposure to risk factors.

RESULTS

The number of subjects undergoing the screening test has increased over the years and the average age of the tested subjects has decreased over time. The main motivation for undergoing HIV testing is unprotected sex. Although heterosexual subjects taking the test were more numerous than homosexuals in this study, an increase in the latter over time should be highlighted.

CONCLUSIONS

Although the number of tests performed has increased over the years, the persistence of unprotected sex shows an inadequate perception of risk. Therefore, it is necessary to implement programmes to increase the general awareness of HIV infection. It is also essential to undertake constant monitoring of behaviour, risk perception and the application of the screening test via surveillance systems in order to implement effective and efficient prevention.

Campylobacter: from microbiology to prevention

In last years, Campylobacter spp has become one of the most important foodborne pathogens even in high-income countries. Particularly, in Europe, Campylobacteriosis is, since 2005, the foodborne disease most frequently notified and the second in USA, preceded by the infection due to Salmonella spp. Campylobacter spp is a commensal microorganism of the gastrointestinal tract of many wild animals (birds such as ducks and gulls), farm animals (cattle and pigs) and companion animals (such as dogs and cats) and it is responsible for zoonoses. The transmission occurs via the fecal-oral route through ingestion of contaminated food and water. The disease varied from a watery diarrhea to a severe inflammatory diarrhea with abdominal pain and fever and can be burdened by some complications. The main recognized sequelae are Guillain-Barré Syndrome (GBS), the Reactive Arthritis (REA) and irritable bowel syndrome (IBS). Recently, many cases of Campylobacter spp isolated from human infections, showed an important resistance to various antibiotics such as tetracyclines and fluoroquinolones. For these reasons, the prevention of this infection plays an essential role. Many preventive measures exist to limit the transmission of the pathogens and the subsequent disease such as the health surveillance, the vaccination of the poultry and the correct food hygiene throughout the entire production chain. A global surveillance of Campylobacteriosis is desirable and should include data from all countries, including notifications of cases and the microbiological data typing of strains isolated from both human and animal cases.

Seroprevalence study on the diffusion of the West Nile virus among blood donors, healthcare workers, jockeys, grooms and fowlers, veterinary surgeons and hunters in Messina (Italy)

INTRODUCTION

West Nile virus (WNV) is a mosquito-transmitted flavivirus widely distributed in Africa, Middle East, Asia, Southern Europe and in 1999 was first identified in the United States as a cause of disease in New York City. It mainly circulates among birds, but can infect many species of mammals. Epidemics can occur in rural as well as urban areas.

METHODS

1,280 sera were collected during 2006 from 80 stable workers, as jockey and grooms, 100 fowlers, 500 blood donors, 600 healthcare workers, 100 veterinary surgeons and 100 hunters in the Messina province to evaluate the prevalence of the WNV infection, by ELISA test, in relation to risk exposure or not.

RESULTS

None of the 1280 subjects examined has shown positive for antibodies anti WN virus.

CONCLUSION

Among the strategies of control and surveillance, finally, in our opinion, are and will be indispensable the programs of continuous antibody survey in all the risk categories and in the general population in order to succeed to preview which effects could have the presence of infections from WNV, also imported from other zones where the virus is constantly present, in future and which it could be the impact of geographic factors on the epidemic spread of the disease.

[Effects of "host factor" bile on adaptability and virulence of Vibrios, foodborne potential pathogenic agents]

In order to improve the knowledge of host/pathogenic agent interaction and to obtain a more careful estimation of risk related to ingestion of food contaminated by Vibrio spp., the effects of bile extracts have been studied. The growth of one V. fluvialis, two V. alginolyticus, and three V. parahaemolyticus strains, isolated from mollusks and crustaceans, has been determined to evaluate their adaptability to intestinal environment. Moreover, the expression of virulence factors responsible for the colonization, as bacterial "swarming mobility", biofilm production, adherence on epithelial cells and hydrophobicity, has been evaluated. Using a bile concentration of 1.5%, all examined strains showed a constant inhibitory effect, quite moderate in the first growth phases. Bile increased the "swarming mobility" and biofilm production; also the adherence was favored, but only after adaptation and during the early logarithmic phase. The decreased hydrophobicity could explain the reduction of adherence during the stationary phase. Studying the phenotypic expression of virulence factors in "minor vibrios" in the presence of bile, it was possible to extend the knowledge about their pathogenetic mechanisms owing to the ingestion of contaminated food. That permits a more careful estimation of risk related to the contamination, considering the high frequency of isolation of these species in some seafood.

Solid state NMR study of sodium thiocyanate/poly(ethylene oxide) electrolytes

1H-, 13C-, 23Na-solid state NMR measurements have been used to characterise the morphology and the dynamics of several NaSCN-PEO mixtures. Selective 13C-MAS experiments allowed to determine the composition of the (PEO)nNaSCN samples in terms of the different phases present, as well as the real stoichiometry of the crystalline complex. 1H- and 13C-spin-lattice relaxation times provided estimates of the dimensions of the different domains and gave information on the dynamics of the polymer chains. 23Na-MAS spectra and 2D nutation experiments allowed to individuate the presence of different environments for the sodium cations on the basis of their quadrupolar interactions.