Implementation and performance of haemovigilance systems in 10 sub-saharan African countries is sub-optimal.

BACKGROUND: Haemovigilance is an important element of blood regulation. It includes collecting and evaluating the information on adverse events resulting from the use of blood and blood components with the aim to improve donor and patient safety. We describe the results of the pilot of the integrated GBT+ Blood for the haemovigilance function in 10 sub-Saharan African countries. METHODS: We piloted the integrated WHO Global Benchmarking Tool plus Blood (GBT+ Blood) to assess the haemovigilance function of national regulatory authorities (NRAs) in Ethiopia, Kenya, Malawi, Nigeria, Liberia, Rwanda, South Africa, Tanzania, Uganda, and Zimbabwe. Data obtained from documents and face to face interviews were used to determine the status of implementation and performance of the following six indicators; legal provisions regulations and guidelines, organisation and governance, human resources, regulatory processes, transparency and accountability and finally, monitoring progress and assessing impact, by estimating median scores across 20 sub-indicators. In addition, a cluster analysis was performed. RESULTS: The countries showed inter-organisation variability in implementation and performance of the haemovigilance function. The overall median score (all sub-indicators) was 44 % (range: 7.5 % - 70 %). The lowest average performance scores were for the arrangement for effective organisation and coordination (35 %) and human resources (35 %) indicators. The highest average scores were observed for the mechanism to promote transparency and mechanism to monitor regulatory performance indicators (50 % and 60 %, respectively). We identified clusters of best-implemented sub-indicators from the procedures for haemovigilance and poorly implemented sub-indicators from the legal provisions, regulations and guidelines for haemovigilance and human resources. CONCLUSIONS: Implementation of sub-indicators and performance of haemovigilance systems varied greatly for all countries with a few countries performing reasonably well in the implementation of some sub-indicators under procedures for haemovigilance. Most countries were poorly implementing sub-indicators in the legal provisions, arrangement for effective organisation and human resources indicators. The legislative provisions in most countries were at a nascent stage. There is a need to set up targeted and customised technical support coupled with prioritised interventions to strengthen the capacities of NRAs.

Parvoviruses cause nuclear envelope breakdown by activating key enzymes of mitosis.

Disassembly of the nuclear lamina is essential in mitosis and apoptosis requiring multiple coordinated enzymatic activities in nucleus and cytoplasm. Activation and coordination of the different activities is poorly understood and moreover complicated as some factors translocate between cytoplasm and nucleus in preparatory phases. Here we used the ability of parvoviruses to induce nuclear membrane breakdown to understand the triggers of key mitotic enzymes. Nuclear envelope disintegration was shown upon infection, microinjection but also upon their application to permeabilized cells. The latter technique also showed that nuclear envelope disintegration was independent upon soluble cytoplasmic factors. Using time-lapse microscopy, we observed that nuclear disassembly exhibited mitosis-like kinetics and occurred suddenly, implying a catastrophic event irrespective of cell- or type of parvovirus used. Analyzing the order of the processes allowed us to propose a model starting with direct binding of parvoviruses to distinct proteins of the nuclear pore causing structural rearrangement of the parvoviruses. The resulting exposure of domains comprising amphipathic helices was required for nuclear envelope disintegration, which comprised disruption of inner and outer nuclear membrane as shown by electron microscopy. Consistent with Ca⁺⁺ efflux from the lumen between inner and outer nuclear membrane we found that Ca⁺⁺ was essential for nuclear disassembly by activating PKC. PKC activation then triggered activation of cdk-2, which became further activated by caspase-3. Collectively our study shows a unique interaction of a virus with the nuclear envelope, provides evidence that a nuclear pool of executing enzymes is sufficient for nuclear disassembly in quiescent cells, and demonstrates that nuclear disassembly can be uncoupled from initial phases of mitosis.

Impact of VP1-specific protein sequence motifs on adeno-associated virus type 2 intracellular trafficking and nuclear entry.

Adeno-associated virus type 2 (AAV2) has gained much interest as a gene delivery vector. A hallmark of AAV2-mediated gene transfer is an intracellular conformational change of the virus capsid, leading to the exposure of infection-relevant protein domains. These protein domains, which are located on the N-terminal portion of the structural proteins VP1 and VP2, include a catalytic phospholipase A(2) domain and three clusters of basic amino acids. We have identified additional protein sequence motifs located on the VP1/2 N terminus that also proved to be obligatory for virus infectivity. These motifs include signals that are known to be involved in protein interaction, endosomal sorting and signal transduction in eukaryotic cells. Among different AAV serotypes they are highly conserved and mutation of critical amino acids of the respective motifs led to a severe infection-deficient phenotype. In particular, mutation of a YXXQ-sequence motif significantly reduced accumulation of virus capsids around the nucleus in comparison to wild-type AAV2. Interestingly, intracellular trafficking of AAV2 was shown to be independent of PLA(2) activity. Moreover, mutation of three PDZ-binding motifs, which are located consecutively at the very tip of the VP1 N terminus, revealed a nuclear transport-defective phenotype, suggesting a role in nuclear uptake of the virus through an as-yet-unknown mechanism.