Development of novel strategies to fill the empty drug pipeline for schistosomiasis: from drug sensitivity assay development to preclinical studies

Schistosomiasis is a neglected tropical disease caused by Schistosoma spp. parasites. It affects more than 200 million people and 700 million more are at risk. Over 10’000 people die every year because of the disease, but this number might be a big underestimation. While the disease is endemic in 78 countries and affects mostly poor communities without access to clean water, the highest prevalence for the disease is found in sub-Saharan Africa with over 85% of the overall occurrences. Children are at especially high risk of exposure through activities such as playing or bathing in infested water bodies. Schistosomiasis is a debilitating disease; the loss of productivity and mortality associated with the disease have a negative effect on the emerging countries' economies, which causes people to be stuck in a negative feedback loop of poverty and public health problems. Poor sanitation and unawareness of the general population are the main reasons for the transmission of schistosomiasis. The first symptoms of the disease are red bumps on the skin, usually appearing a few hours after infection and sometimes followed by mild fever and nausea. However, the chronic effects are more serious. In fact, children affected by the disease often show developmental delays and adults may develop chronic hepatic damage and eventually liver failure. There is only one drug available for mass drug administration (MDA) campaigns: praziquantel. There is growing evidence of a decreasing efficacy of praziquantel against Schistosoma spp. There is no vaccine available and the drug pipeline to treat schistosomiasis is empty. The overwhelming prevalence of schistosomiasis in the developing world and the absence of novel drug candidates against the disease are provoking fear of resistance emergence among the handful of laboratories involved in the fight against this neglected tropical disease (NTD). The research of novel compounds moves slowly and one of the main reasons for this is the difficulty in finding a reliable and faster drug screening method that would increase the drug screening output and the concordance between laboratories involved in the drug screening process. During my PhD, I worked on different projects tackling schistosomiasis, searching for ways to speed up drug screening processes and to contribute to the currently empty drug pipeline. I worked on a protocol, in which we detail all the aspects of the drug screening procedure, with the aim to familiarize new laboratories with the procedures as we do them here at Swiss TPH, in order to decrease the methodological fragmentation in the field. I worked on the development of novel drug screening platforms and new methods to identify potential drug candidates. In collaboration with the Department of Biosystems Science and Engineering (D-BSSE) of ETH located in Basel, we developed a novel platform for antischistosomal drug screening based on microfluidic electrical impedance spectroscopy (EIS). Also, I worked on a human liver microtissue-based system to assess the liver metabolism for extending the standard drug screening assays in vitro on NTS to prodrugs, and to evaluate the liver metabolism's effect on the compounds’ activity on NTS in vitro. I first validated the system with praziquantel and then quantified the amount of compound metabolised and tested the effect of the liver metabolites on NTS in vitro with other compounds that are approved for human medicine. Finally, in an attempt to resolve the issue of praziquantel's low solubility, I collaborated with the University of Trieste in the development and testing of a novel formulation of praziquantel. This novel praziquantel formulation was based on a polymorph co-crystal provided by the University of Trieste. I tested this formulation derivative in vivo and in vitro to compare it to the standard praziquantel to evaluate its activity. I quantified praziquantel enantiomers by LC-MS/MS in mice plasma and compared the pharmacokinetics of the standard praziquantel with the polymorph praziquantel derivative. In this thesis, all of the above-mentioned projects are contextualised and discussed

Is the clinical pattern of pediatric celiac disease changing? A thirty-years real-life experience of an Italian center

Objectives Clinical presentation of pediatric celiac disease (CD) is heterogeneous and ever-evolving. Our aim is to highlight its changes throughout the years. Methods Data about clinical presentation of CD in children diagnosed between 1990 and 2020 at the CD Center of Maggiore Hospital, Bologna, were collected. Patients were stratified into groups based on the date [P1 (1990-2011), P2 (2012-2020)] and age [G1 (< 2 years), G2 (2-5), G3 (6-11), G4 (12-18)] at diagnosis, then investigated by comparing CD clinical presentation in different periods and ages. Results 1081 children were selected. Mean age at diagnosis increases from 5.9 to 6.6 years from P1 to P2. Gastrointestinal Symptoms (GIs) are predominant, with a decline of diarrhea (47%VS30%) and an increase of constipation (4%VS19%) (p < 0.001). Among Extraintestinal symptoms (EIs) a decrease of anemia (76%VS43%, p = 0,001) is observed. Failure to Thrive (FTT) is stable throughout the years (p = 0.03), while screenings show a trend of increment (19%VS23%). GIs' frequency decline from G1 to G4 (p = 0,001), with reduction of diarrhea (p < 0.001), and rise of recurrent abdominal pain (p = 0,02). EIs are more frequent at older ages, FTT in younger patients. Conclusions Changes in clinical presentation of CD have occurred in the last 30 years. We observe a reduction of severe and classic gastroenterologic symptoms and a rise of atypical ones, together with a growth of serological screenings and higher age at diagnosis. Awareness about CD clinical trends is crucial for a proper approach and early diagnosis

Processing of social and monetary rewards in autism spectrum disorders

Background: Reward processing has been proposed to underpin the atypical social feature of autism spectrum disorder (ASD). However, previous neuroimaging studies have yielded inconsistent results regarding the specificity of atypicalities for social reward processing in ASD. Aims: Utilising a large sample, we aimed to assess reward processing in response to reward type (social, monetary) and reward phase (anticipation, delivery) in ASD. Method: Functional magnetic resonance imaging during social and monetary reward anticipation and delivery was performed in 212 individuals with ASD (7.6-30.6 years of age) and 181 typically developing participants (7.6-30.8 years of age). Results: Across social and monetary reward anticipation, whole-brain analyses showed hypoactivation of the right ventral striatum in participants with ASD compared with typically developing participants. Further, region of interest analysis across both reward types yielded ASD-related hypoactivation in both the left and right ventral striatum. Across delivery of social and monetary reward, hyperactivation of the ventral striatum in individuals with ASD did not survive correction for multiple comparisons. Dimensional analyses of autism and attention-deficit hyperactivity disorder (ADHD) scores were not significant. In categorical analyses, post hoc comparisons showed that ASD effects were most pronounced in participants with ASD without co-occurring ADHD. Conclusions: Our results do not support current theories linking atypical social interaction in ASD to specific alterations in social reward processing. Instead, they point towards a generalised hypoactivity of ventral striatum in ASD during anticipation of both social and monetary rewards. We suggest this indicates attenuated reward seeking in ASD independent of social content and that elevated ADHD symptoms may attenuate altered reward seeking in ASD

Sense of smell in chronic rhinosinusitis: A multicentric study on 811 patients

Introduction: The impairment of the sense of smell is often related to chronic rhinosinusitis (CRS) with or without nasal polyps (CRSwNP, CRSsNP). CRSwNP is a frequent condition that drastically worsens the quality of life of those affected; it has a higher prevalence than CRSsNP. CRSwNP patients experience severe loss of smell with earlier presentation and are more likely to experience recurrence of their symptoms, often requiring revision surgery. Methods: The present study performed a multicentric data collection, enrolling 811 patients with CRS divided according to the inflammatory endotype (Type 2 and non-Type 2). All patients were referred for nasal endoscopy for the assessment of nasal polyposis using nasal polyp score (NPS); Sniffin' Sticks olfactory test were performed to measure olfactory function, and SNOT-22 (22-item sinonasal outcome test) questionnaire was used to assess patients' quality of life; allergic status was evaluated with skin prick test and nasal cytology completed the evaluation when available. Results: Data showed that Type 2 inflammation is more common than non-type 2 (656 patients versus 155) and patients suffer from worse quality of life and nasal polyp score. Moreover, 86.1% of patients with Type 2 CRSwNP were affected by a dysfunction of the sense of smell while it involved a lesser percentage of non-Type 2 patients. Indeed, these data give us new information about type-2 inflammation patients' characteristics. Discussion: The present study confirms that olfactory function weights on patients' QoL and it represents an important therapeutic goal that can also improve patients' compliance when achieved. In a future - and present - perspective of rhinological precision medicine, an impairment of the sense of smell could help the clinician to characterize patients better and to choose the best treatment available

Mass testing of the JUNO experiment 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%

Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

Validation and integration tests of the JUNO 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO will be able to study the neutrino mass ordering and to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, the electronic system has to meet specific tight requirements, and a thorough characterization is required. The present paper describes the tests performed on the readout modules to measure their performances.Comment: 20 pages, 13 figure