An Investigation of the Steady-State Pharmacokinetics of Oral Valacyclovir in Immunocompromised Children

Valacyclovir was administered to 28 immunocompromised children (ages 5-12 years) to obtain preliminary pharmacokinetic and safety information. Patients were randomized to valacyclovir regimens of 250 mg (9.4-13.3 mg/kg) or 500 mg (13.9-27.0 mg/kg) twice daily or 500 mg (13.2-21.7 mg/kg) 3 times a day. Acyclovir pharmacokinetics were evaluated at steady state. Valacyclovir was rapidly absorbed and converted to acyclovir. Mean (±SD) acyclovir peak concentrations from 250 mg and 500 mg valacyclovir were 4.11±1.41 and 5.19±1.96 μg/mL, respectively. Corresponding single dose area-under-curve values were 12.14±6.60 and 14.49±4.69h×μg/mL. By using historical data for intravenous acyclovir as reference, the overall estimate of acyclovir bioavailability from valacyclovir was 48%, 2- to 4-fold greater than for oral acyclovir. In general, adverse events were not attributable to valacyclovir and were consistent with disease-related expectations and concomitant therapies. Dosage options for using valacyclovir in children are discusse

Regulation of hepatic EAAT-2 glutamate transporter expression in human liver cholestasis

AIM: To investigate the activity and expression of EAAT2 glutamate transporter in both in vitro and in vivo models of cholestasis. METHODS: This study was conducted on human hepatoblastoma HepG2 cell cultures, the liver of bile duct ligated rats and human specimens from cholestatic patients. EAAT2 glutamate transporter activity and expression were analyzed using a substrate uptake assay, immunofluorescence, reverse transcription-polymerase chain reaction, and immunohistochemistry, respectively. RESULTS: In HepG2 cells, cholestasis was mimicked by treating cells with the protein kinase C activator, phorbol 12-myristate 13-acetate. Under such conditions, EAAT2 transporter activity was decreased both at the level of substrate affinity and maximal transport velocity. The decreased uptake was correlated with intracellular translocation of EAAT2 molecules as demonstrated using immunofluorescence. In the liver of bile duct ligated rats, an increase in EAAT2 transporter protein expression in hepatocytes was demonstrated using immunohistochemistry. The same findings were observed in human liver specimens of cholestasis in which high levels of γ-glutamyl transpeptidase were documented in patients with biliary atresia and progressive familial intrahepatic cholestasis type 3. CONCLUSION: This study demonstrates the alteration in glutamate handling by hepatocytes in liver cholestasis and suggests a potential cross-talk between glutamatergic and bile systems

EPTRI Belgian Joint Research Unit : harmonisation and concertation of paediatric research in Belgium to ensure better and safer healthcare for children

We want to put the excellent translational paediatric research in Belgium on the ESFRI national roadmap in order to participate in the European Paediatric Translational Research Infrastructure (EPTRI) project. Therefore, we are in the preparatory phase to form a Belgian national EPTRI Joint Research Unit (JRU). Academic research organisations and hospitals from both regions, Flanders and Wallonia are currently involved. The Belgian JRU partners will gather complementary scientific and technological competencies in the different EPTRI thematic research platforms: 1. Paediatric medicines discovery: with different types of “in vitro” paediatric models, placental and umbilical cord and 3D organoid cell cultures from paediatric samples and juvenile animal models such as the rabbit BPD model, juvenile Göttingen minipig, juvenile conventional pig model and developmental zebrafish model; 2. Paediatric biomarkers and biosamples: identification, characterisation and validation of the biomarkers used as prognostic tools, safety markers and diagnostic tools in paediatric diseases; 3. Developmental pharmacology: including PK (bioavaibility/bioequivalence) studies, Population PKPD analysis and PK/PD modelling; 4. Paediatric medicines formulations and medical devices: including regulatory knowledge of paediatric medical devices. The partners will ensure a strong liaison with other RI’s such as the BBMRI-ERIC for paediatric biobanking and the IMI conect4children network paediatric clinical trials. We propose an integrated paediatric research system that links together EPTRI Belgium with landmark RIs, conect4children and the many paediatric clinical research networks and institutions that provide services to paediatric research. This integrated system can provide: expertise, experienced facilities and practical support for pre-clinical and clinical paediatric research in Belgium and Europe. Sharing understanding of patients’ needs and concerted efforts in paediatric research will further enhance the health of children

Sofosbuvir and Ribavirin Therapy for Children Aged 3 to <12 Years With Hepatitis C Virus Genotype 2 or 3 Infection.

Currently, the only approved hepatitis C virus (HCV) treatment for children aged <12 years is pegylated interferon plus ribavirin. In an open-label study, we evaluated the safety and efficacy of sofosbuvir plus ribavirin for 12 weeks in children aged 3 to <12 years chronically infected with genotype 2 or for 24 weeks in patients with genotype 3. Patients aged 3 to <6 years weighing <17 kg received sofosbuvir 150 mg, and patients aged 3 to <6 years weighing ≥17 kg and all patients aged 6 to <12 years received sofosbuvir 200 mg once daily. Intensive pharmacokinetic sampling conducted in each age group confirmed the appropriateness of sofosbuvir doses. For all patients, ribavirin dosing was determined by baseline weight (up to 1,400 mg/day, two divided doses). The primary efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Fifty-four patients were enrolled (41 aged 6 to <12 years and 13 aged 3 to <6 years). Most were treatment naïve (98%) and infected perinatally (94%). All but one patient achieved SVR12 (53/54, 98%; 95% confidence interval, 90%-100%). The patient who did not achieve SVR12 was a 4-year-old who discontinued treatment after 3 days because of "abnormal drug taste." The most commonly reported adverse events in patients aged 6 to <12 years were vomiting (32%) and headache (29%), and those in patients aged 3 to <6 years were vomiting (46%) and diarrhea (39%). One 3-year-old patient had a serious adverse event of accidental ribavirin overdose requiring hospitalization for monitoring; this patient completed treatment and achieved SVR12. Conclusion: Sofosbuvir plus ribavirin was well tolerated and highly effective in children aged 3 to <12 years with chronic HCV genotype 2 or 3 infection

MPV17 does not control cancer cell proliferation

MPV17 is described as a mitochondrial inner membrane channel. Although its function remains elusive, mutations in the MPV17 gene result in hepato-cerebral mitochondrial DNA depletion syndrome in humans. In this study, we show that MPV17 silencing does not induce depletion in mitochondrial DNA content in cancer cells. We also show that MPV17 does not control cancer cell proliferation despite the fact that we initially observed a reduced proliferation rate in five MPV17-silenced cancer cell lines with two different shRNAs. However, shRNA-mediated MPV17 knockdown performed in this work provided misguiding results regarding the resulting proliferation phenotype and only a rescue experiment was able to shed definitive light on the implication of MPV17 in cancer cell proliferation. Our results therefore emphasize the caution that is required when scientific conclusions are drawn from a work based on lentiviral vector-based gene silencing and clearly demonstrate the need to systematically perform a rescue experiment in order to ascertain the specific nature of the experimental results

Eliminating viral hepatitis C in Belgium: the micro-elimination approach

Background: Hepatitis C virus is one of the leading causes of chronic liver disease and liver-related deaths worldwide. The estimated prevalence of chronic hepatitis C viral infection among the general Belgian population was 0.57% (n = 64,000) in 2015. Although Belgium has had a ‘Hepatitis C Plan’ since 2014, elimination efforts are unclear. This study employs the best available data and modelling estimates to define the burden of hepatitis C viral infection among key subgroups in Belgium, identify information gaps and propose potential approaches to screening, linkage to care and treatment, and cure. Methods: We examined the peer-reviewed and grey literature since 2012 for data on the prevalence of hepatitis C viral infection in Belgium in key subgroups identified by national experts and in the literature. Ultimately, this research is primarily based on data provided by the key stakeholders themselves due to a lack of reliable data in the literature. Based on this, we modelled the treatment rates required to reach elimination of hepatitis C in several subgroups. Results: Eleven potential subgroups were identified. There were no data available for two subgroups: generational cohorts and men who have sex with men. In six subgroups, fewer than 3000 people were reported or estimated to have hepatitis C infection. Migrants and people who inject drugs were the most affected subgroups, and children were the least affected subgroup. Only two subgroups are on target to achieve elimination by 2030: patients living with haemophilia and transplant recipients. Conclusions: Removing Belgian treatment reimbursement restrictions in January 2019 was a big step towards eliminating HCV. In addition, increasing surveillance, including with a national registry, treatment prescription by other health-care providers and availability of treatment in local pharmacies are central to improving the current situation and getting on track to reach the 2030 WHO hepatitis C elimination targets in Belgium

Integrative miRNA and Gene Expression Profiling Analysis of Human Quiescent Hepatic Stellate Cells.

Unveiling the regulatory pathways maintaining hepatic stellate cells (HSC) in a quiescent (q) phenotype is essential to develop new therapeutic strategies to treat fibrogenic diseases. To uncover the miRNA-mRNA regulatory interactions in qHSCs, HSCs were FACS-sorted from healthy livers and activated HSCs (aHSCs) were generated in vitro. MiRNA Taqman array analysis showed HSCs expressed a low number of miRNAs (n = 259), from which 47 were down-regulated and 212 up-regulated upon activation. Computational integration of miRNA and gene expression profiles revealed that 66% of qHSC-associated miRNAs correlated with more than 6 altered target mRNAs (17,28 ± 10,7 targets/miRNA) whereas aHSC-associated miRNAs had an average of 1,49 targeted genes. Interestingly, interaction networks generated by miRNA-targeted genes in qHSCs were associated with key HSC activation processes. Next, selected miRNAs were validated in healthy and cirrhotic human livers and miR-192 was chosen for functional analysis. Down-regulation of miR-192 in HSCs was found to be an early event during fibrosis progression in mouse models of liver injury. Moreover, mimic assays for miR-192 in HSCs revealed its role in HSC activation, proliferation and migration. Together, these results uncover the importance of miRNAs in the maintenance of the qHSC phenotype and form the basis for understanding the regulatory networks in HSCs

The Effect of Chemical Information on the Spatial Distribution of Fruit Flies: I Model Results

Animal aggregation is a general phenomenon in ecological systems. Aggregations are generally considered as an evolutionary advantageous state in which members derive the benefits of protection and mate choice, balanced by the costs of limiting resources and competition. In insects, chemical information conveyance plays an important role in finding conspecifics and forming aggregations. In this study, we describe a spatio-temporal simulation model designed to explore and quantify the effects of these infochemicals, i.e., food odors and an aggregation pheromone, on the spatial distribution of a fruit fly (Drosophila melanogaster) population, where the lower and upper limit of local population size are controlled by an Allee effect and competition. We found that during the spatial expansion and strong growth of the population, the use of infochemicals had a positive effect on population size. The positive effects of reduced mortality at low population numbers outweighed the negative effects of increased mortality due to competition. At low resource densities, attraction toward infochemicals also had a positive effect on population size during recolonization of an area after a local population crash, by decreasing the mortality due to the Allee effect. However, when the whole area was colonized and the population was large, the negative effects of competition on population size were larger than the positive effects of the reduction in mortality due to the Allee effect. The use of infochemicals thus has mainly positive effects on population size and population persistence when the population is small and during the colonization of an area