Investigations on new and forgotten antischistosomal drugs and praziquantel pharmacokinetics in opisthorchiasis patients

Neglected tropical diseases (NTDs) are defined as a group of communicable diseases, most prevalent in tropical and subtropical regions of the world. Prevailing over the poorest populations that have limited access to sanitation, hygiene and education, NTDs affect more than one billion people worldwide and are endemic in 149 countries. Schistosomiasis, caused by blood-dwelling trematode flatworms of the Schistosoma genus is a neglected parasitic disease. The tremendous disease burden of schistosomiasis is associated with anemia, malnutrition as well as impaired childhood development and causes high morbidity for more than 200 million infected individuals. Praziquantel (PZQ) is the sole drug currently available; morbidity reduction using preventive chemotherapy relies completely on PZQ. Apart from its lack of activity against developing stages of the worm and the fact that PZQ is rarely curative, its abundant use incurs the possibility of drug resistance. Thus, there is an urgent need to identify and develop novel therapeutic principles. Opisthorchiasis, caused by the liver fluke Opisthorchis felineus is a food-borne trematodiasis with worldwide highest prevalence in Western Siberia. There are 12.5 million individuals at risk for an infection. The disease erupts upon dietary consumption of raw or undercooked fish infested with trematode larvae. It affects the hepatobiliary system and can lead to pancreatitis or even severe chronic infections such as hepatic abscesses. As for schistosomiasis, the drug of choice for the treatment of opisthorchiasis is praziquantel. The doses used are empirical and prescribed individually, the whole treatment scheme is very complicated and takes about three months to be accomplished; thus it makes it unavailable for many people. My PhD thesis had two major aims. The first was to advance antischistosomal drug discovery by identifying novel chemical entities and by rescuing a forgotten lead candidate. The second was to elucidate the pharmacokinetic properties of praziquantel in O. felineus infected patients, laying the groundwork for a simplified standardized treatment scheme. iv A first study we conducted to achieve the first aim; followed-up on an existing structure-activity relationship (SAR) program, the antischistosomal in vitro and in vivo activities of a 3rd generation pyridobenzimidazole (PBI) drug set were evaluated. We found high in vitro activities against Schistosoma mansoni newly transformed schistosomula (NTS) and adult worms, with IC50 values of 0.08 – 1.43 μM. Upon promising results obtained from metabolic stability assays with liver microsomes (>80%), we engaged in efficacy testing using infected mice. Moderate to high worm burden reductions (WBR) of 36 – 90 % were obtained after single oral doses of four selected compounds. However, we observed a small therapeutic window although results obtained from cytotoxicity screens against CHO and HepG2 cells did not foresee toxicity. In order to expand SAR studies around another promising chemotype, N,N’-diarylureas, we investigated a novel series of analogs featuring the pentafluorosulfanyl group (SF5). High in vitro activity, acceptable cytotoxicity profiles and high microsomal hepatic stability were found. IC50 values for the most promising compounds were between 0.8 and 1.8 μM for NTS and 0.1 – 0.4 μM for adult S. mansoni. However, none of the compounds tested in S. mansoni infected mice revealed in vivo efficacy. Results obtained from an accompanying PK study, showed that all tested compounds were slowly absorbed and only reached maximal plasma concentration values after 24 h. There was no correlation between drug exposure and in vivo efficacy. Extracts and fractions of the medicinal plants Artemisia annua and Artemisia afra were tested for their in vitro activity against S. mansoni NTS and adult worms. We comparatively evaluated a set of extracts and fractions and found low IC50 vales, especially for the A. afra (BB) hexane and DCM fractions. The findings suggest that A. afra, despite lacking the bioactive compound artemisinin found in A. annua, is more active than the latter, further warranting studies to identify novel molecules. Our studies on the largely forgotten lead candidate, Ro 15-5458, found high in vivo efficacy across the whole development stage of S. mansoni, when the drug was administered as a single oral dose of 50 mg/kg. Low ED50 of 5.3 and 15 mg/kg were obtained for mice harboring adult and juvenile infections, respectively. Ro 15-5458 was also tested against S. v haematobium and S. japonicum. We found an ED50 value of 17 mg/kg in hamsters harboring a patent S. haematobium infection; however, the compound was inactive at up to 100 mg/kg in S. japonicum infected mice. In vitro, a de-ethylated and a glucoronidated product were identified and the metabolic stability was evaluated using microsomes and hepatocytes. The low in vitro activity against NTS and adult worms and the late onset of action correlated with results obtained from hepatic shift experiments conducted S. mansoni infected mice. Ro 15- 5458 had a half-life of approximately 5 h and the maximal plasma concentration was reached after 3 h (8 µg/mL) when a 50 mg/kg oral dose was administered to healthy mice. In the context of a randomized controlled, single-blinded dose finding trial in Tomsk, Siberia, we conducted, for the second aim of this thesis, a PK study in O. felineus infected patients and assessed the kinetic disposition of both praziquantel enantiomers (R-PZQ and S-PZQ) and the drug’s main metabolite (R-trans-4-OH-PZQ). Single, ascending doses of 20, 40 and 60 mg/kg were compared to multiple dosing (3 x 60 mg/kg). Dried blood spots (DBS) collected over 24 h were analyzed using a validated LC-MS/MS method. Maximal plasma concentrations were reached after 1.5 h (1.72 μg/mL), 2 h (4.89 μg/mL) and 3 h (2.69 μg/mL) for R-, S- and R-trans-OH-PZQ, respectively, when praziquantel was given as a single 60 mg/kg dose. Highest exposure levels (AUC) were observed for the triple dose scheme with AUC vales of 8.04, 27.75 and 36.38 μg/mL*h, respectively. In conclusion, we present two sets of promising antischistosomal drug candidates, the PBIs and the N,N’-diarylureas. Our studies complement early drug discovery efforts around both chemotypes and provide insights for a next generation of optimized antischistosomal PBIs and N,N’-diarylureas. Additionally, extracts from medicinal plants such as A. annua and A. afra present potential alternatives to small molecules. Concurrently, Ro 15-5458 is an excellent lead candidate, efficacious alongside all stages of S. mansoni development, and further warrants investigations. Finally, praziquantel disposition in O. felineus infected individuals has been evaluated and in combination with the results from the efficacy study will be pivotal to establish an evidence based dosing recommendation

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

ABSTRACT In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents

Abstracts of the 9th International Organisation of Physical Therapy in Mental Health Conference

This book contains the abstracts of the papers presented at the 9th International Organisation of Physical Therapy in Mental Health Conference, Organized by the International Organisation of Physical Therapy in Mental Health and Greek Scientific Section “Physiotherapy in Mental Health” of PanHellenic Physiotherapists’ Association, held on 4–6 May 2022. It is the biannual conference of the International Organization of Physical Therapy in Mental Health (IOPTMH), and we answered with success the question: Physiotherapy in mental health; what’s next? The highly qualified scientific program, the reputable presenters, and the venue altogether form a powerful motivation for both physiotherapists and other mental health professionals to attend this conference. Conference Title: 9th International Organisation of Physical Therapy in Mental Health ConferenceConference Theme: Physiotherapy in mental health; what’s next?Conference Date: 4–6 May 2022Conference Location: Crowne Plaza Athens - City Centre Hotel, 50, Michalakopoulou Str. GR 11528 AthensConference Organizer: International Organisation of Physical Therapy in Mental Health and Greek Scientific Section “Physiotherapy in Mental Health” of PanHellenic Physiotherapists’ AssociationConference Secretariat - Public Relations: Alpha Public Relations and Integrated Marketing S.A., 55, Pytheou Str. GR 11743 Athen