Isabelle Huys

kappa-Hefutoxin1, a novel toxin from the scorpion Heterometrus fulvipes with unique structure and function. Importance of the functional diad in potassium channel selectivity

An important and exciting challenge in the postgenomic era is to understand the functions of newly discovered proteins based on their structures. The main thrust is to find the common structural motifs that contribute to specific functions. Using this premise, here we report the purification, solution NMR, and functional characterization of a novel class of weak potassium channel toxins from the venom of the scorpion Heterometrus fulvipes. These toxins, κ-hefutoxin1 and κ-hefutoxin2, exhibit no homology to any known toxins. NMR studies indicate that κ-hefutoxin1 adopts a unique three-dimensional fold of two parallel helices linked by two disulfide bridges without any β−sheets. Based on the presence of the functional diad (Tyr5/Lys19) at a distance (6.0 ± 1.0 Å) comparable with other potassium channel toxins, we hypothesized its function as a potassium channel toxin. κ-Hefutoxin 1 not only blocks the voltage-gated K+-channels, Kv1.3 and Kv1.2, but also slows the activation kinetics of Kv1.3 currents, a novel feature of κ-hefutoxin 1, unlike other scorpion toxins, which are considered solely pore blockers. Alanine mutants (Y5A, K19A, and Y5A/K19A) failed to block the channels, indicating the importance of the functional diad.

A novel conotoxin inhibiting vertebrate voltage-sensitive potassium channels.

Toxins from cone snail (Conus species) venoms are multiple disulfide bonded peptides. Based on their pharmacological target (ion channels, receptors) and their disulfide pattern, they have been classified into several toxin families and superfamilies. Here, we report a new conotoxin, which is the first member of a structurally new superfamily of Conus peptides and the first conotoxin affecting vertebrate K+ channels. The new toxin, designated conotoxin ViTx, has been isolated from the venom of Conus virgo and comprises a single chain of 35 amino acids cross-linked by four disulfide bridges. Its amino acid sequence (SRCFPPGIYCTSYLPCCWGICCSTCRNVCHLRIGK) was partially determined by Edman degradation and deduced from the nucleotide sequence of the toxin cDNA. Nucleic acid sequencing also revealed a prepropeptide comprising 67 amino acid residues and demonstrated a posttranslational modification of the protein by releasing a six-residue peptide from the C-terminal. Voltage clamp studies on various ion channels indicated that the toxin inhibits the vertebrate K+ channels Kv1.1 and Kv1.3 but not Kv1.2. The chemically synthesized product exhibited the same physiological activity and identical molecular mass (3933.7 Da) as the native toxin.

Call for a dedicated European legal framework for bacteriophage therapy.

The worldwide emergence of antibiotic resistances and the drying up of the antibiotic pipeline have spurred a search for alternative or complementary antibacterial therapies. Bacteriophages are bacterial viruses that have been used for almost a century to combat bacterial infections, particularly in Poland and the former Soviet Union. The antibiotic crisis has triggered a renewed clinical and agricultural interest in bacteriophages. This, combined with new scientific insights, has pushed bacteriophages to the forefront of the search for new approaches to fighting bacterial infections. But before bacteriophage therapy can be introduced into clinical practice in the European Union, several challenges must be overcome. One of these is the conceptualization and classification of bacteriophage therapy itself and the extent to which it constitutes a human medicinal product regulated under the European Human Code for Medicines (Directive 2001/83/EC). Can therapeutic products containing natural bacteriophages be categorized under the current European regulatory framework, or should this framework be adapted? Various actors in the field have discussed the need for an adapted (or entirely new) regulatory framework for the reintroduction of bacteriophage therapy in Europe. This led to the identification of several characteristics specific to natural bacteriophages that should be taken into consideration by regulators when evaluating bacteriophage therapy. One important consideration is whether bacteriophage therapy development occurs on an industrial scale or a hospital-based, patient-specific scale. More suitable regulatory standards may create opportunities to improve insights into this promising therapeutic approach. In light of this, we argue for the creation of a new, dedicated European regulatory framework for bacteriophage therapy.

Insights into European drug shortages: a survey of hospital pharmacists.

Drug shortages are a complex and global phenomenon. When a drug cannot be delivered at the moment of patient demand, every stakeholder in the health care system is affected. The aim of this study was to investigate the characteristics, clinical impact, financial impact and management of drug shortages in European hospital pharmacies and identify opportunities for prevention and mitigation of drug shortages in Europe. An online survey was designed based on a review of the literature and interviews and was sent to subscribers of Hospital Pharmacy Europe between June and September 2013. Forty-five percent of respondents (n = 161) indicated that life sustaining or life preserving drugs such as oncology drugs were affected by drug shortages. More than 30% of respondents indicated that drug shortages in Europe were always or often associated with increased costs for hospitals, increased personnel costs and more expensive alternative drugs (n = 161). On the question when information about a drug shortage was obtained, 42% of respondents answered that information from the pharmaceutical company was obtained at the time of no delivery, 50% indicated that information from the wholesaler was obtained at the time of no delivery, while 40% of respondents indicated that information was never or rarely received from the government (n = 161). Fifty seven percent of respondents strongly agreed that an obligation to the producer to notify further shortages could help to solve the problem (n = 161). These results showed that pharmaceutical companies and wholesalers are already involved in the management of drug shortages, while a role is still reserved for the government. Mandatory notification in advance and centralized information can help to reduce workload for hospital pharmacists, will allow early anticipation of drug shortages and will facilitate mitigation of the clinical impact on patients.

Electrophysiological characterization of BmK M1, an α-like toxin from Buthus martensi Karsch venom

The present study investigates the electrophysiological actions of BmK M1, an α‐like toxin purified from the venom of the scorpion Buthus martensi Karsch, on voltage‐gated Na+ channels. Using the voltage clamp technique, we assessed the BmK M1 activity on the cardiac Na+ channel (hH1) functionally expressed in Xenopus oocytes. The main actions of the toxin are a concentration‐dependent slowing of the inactivation process and a hyperpolarizing shift of the steady‐state inactivation. This work is the first electrophysiological characterization of BmK M1 on a cloned Na+ channel, demonstrating that this toxin belongs to the class of scorpion α‐toxins. Our results also show that BmK M1 can be considered as a cardiotoxin.

Drug shortages in European countries: a trade-off between market attractiveness and cost containment?

BackgroundDrug shortages are a global problem. While extensively studied in the United States, numbers about drug shortages in European countries are scarce. This study aims to collect and present data about drug shortages in European countries.MethodsA reporting template for the collection of data about drug shortages was designed based on a literature search. Countries offering a reporting system for drug shortages such as Belgium, the Netherlands, England, Italy, France, Germany and Spain were included in this study. Data about the characteristics of the drugs in shortage and the causes of the shortage were collected from publicly available online reporting systems. Descriptive analyses were performed.ResultsDrug shortages included in the considered reporting systems can be characterized as branded, oral drugs that affect different disease domains. When considering essential medicines and oncology drugs, generic injectables are more involved. Causes for drug shortages are largely underreported. In case the cause is known, production problems take the lead.ConclusionsReporting of drug shortages in Europe needs to be standardized and more transparency about the reasons for drug shortage is required to investigate the problem. A link between production problems and market attractiveness and market capacity is recognized to be at the root of drug shortages in U.S. Such insights are highly lacking in Europe. Monitoring of the effect of national and European health policies on the sustainability of the drug market is required to present fundamental solutions and to tackle the problem of drug shortages in Europe.

The fate and future of patents on human genes and genetic diagnostic methods.

Since the 1970s, patents on human genes and genetic diagnostic methods have been granted under the assumption that they stimulate the development of diagnostic methods and therapeutic products. However, the principles and practices of patenting vary between jurisdictions. Do patent holders, researchers, clinicians and patients really benefit from this heterogeneous patent system? We discuss the problems that result from the current system and suggest how they might be solved by altering the way in which patents are granted and/or licensed.

A bacteriophage journey at the European Medicines Agency.

The seriously and globally increasing bacterial multi-drug resistance calls out on concerted counteractive measures: international health authorities give consideration to the therapeutical use of bacteriophage therapy.

Paving a regulatory pathway for phage therapy. Europe should muster the resources to financially, technically and legally support the introduction of phage therapy.

The growing problem of antibiotic-resistant bacteria has re-kindled interest in phage-based therapies. Yet, the use of phages to treat life-threatening bacterial infections is held back by the lack of an appropriate regulatory framework for phage therapy.

Causes of drug shortages in the legal pharmaceutical framework.

INTRODUCTION Different causes of drug shortages can be linked to the pharmaceutical legal framework, such as: parallel trade, quality requirements, economic decisions to suspend or cease production, etc. However until now no in-depth study of the different regulations affecting drug shortages is available. The aim of this paper is to provide an analysis of relevant legal and regulatory measures in the European pharmaceutical framework which influence drug shortages. METHODS Different European and national legislations governing human medicinal products were analyzed (e.g. Directive 2001/83/EC and Directive 2011/62/EU), supplemented with literature studies. RESULTS For patented drugs, external price referencing may encompass the largest impact on drug shortages. For generic medicines, internal or external reference pricing, tendering as well as price capping may affect drug shortages. Manufacturing/quality requirements also contribute to drug shortages, since non-compliance leads to recalls. The influence of parallel trade on drug shortages is still rather disputable. CONCLUSION Price and quality regulations are both important causes of drug shortages or drug unavailability. It can be concluded that there is room for improvement in the pharmaceutical legal framework within the lines drawn by the EU to mitigate drug shortages.