Bristol Institute for Transfusion Sciences

New and emerging infections with blood-borne pathogens pose an ongoing threat to the safety of blood transfusions and transplants. Bioarchives of stored blood donor samples represent a valuable pathogen screening resource for both ensuring safety of blood transfusions and for wider public health infectious disease surveillance. Large scale testing of donors enables early detection of pathogen spread and extent of population exposure. We have implemented two complementary systems for the bioarchiving of blood donor samples in England for these purposes. The CODONET bioarchive collects samples from geographically targeted regions of potential pathogen emergence. Consenting donors provide detailed information to allow for risk assessment and, importantly, to distinguish imported from autochthonously acquired infection. Separately, the blood donor surveillance archive (BDSA) stores 100 or 200 pools of 24 randomly selected, fully anonymised donation samples from donors in England every 2 weeks, allowing large-scale continuous sampling. This enables rapid evaluation of the presence of blood-borne pathogens in donor populations and a large-scale epidemiological tool to detect pathogen emergence in real-time. Combined, these bioarchives allow for proactive assessment of donation transmission risk, and as targeted population-wide archives, contribute to public health surveillance of emerging pathogens and pandemic spread.

ObjectiveTo assess to what extent the clinical trial policies of the largest public and philanthropic funders of clinical research in the United States meet WHO best practices in trial registration and reporting.MethodsPublic and philanthropic funders of clinical trials in the USA with >US$50 million annual spend were selected. The funders were assessed using an 11-item scoring tool based on WHO Joint Statement benchmarks. These 11 items fell into 4 categories, namely: trial registration, academic publication, monitoring and sanctions. An additional item captured whether and how funders referred to Consolidated Standards of Reporting Trials (CONSORT) within their trial policies. Each funder was independently assessed by two or three researchers. Funders were contacted to flag possible errors and omissions. Ambiguous or difficult-to-score items were settled by an independent adjudicator.ResultsFourteen funders were assessed. Our cross-sectional study found that, on average, funders have only implemented 4.1/11 (37%) of WHO best practices in clinical trial transparency. The most frequently adopted requirement was open access publishing (14/14 funders). The least frequently adopted were (1) requiring trial ID to appear in all publications (2/14 funders, 14%) and (2) making compliance reports public (2/14 funders, 14%). Public funders, on average, adopted more policy elements (5.2/11 items, 47%) than philanthropic funders (2.8/11 items, 25%). Only one funder’s policy documents mentioned the CONSORT statement.ConclusionsThere is a significant variation between the number of best practice policy items adopted by medical research funders in the USA. Many funders fell significantly short of WHO Joint Statement benchmarks. Each funder could benefit from policy revision and strengthening.

This cross-sectional study compares the duration of postapproval trials with that of the pivotal trials used as the basis for the US Food and Drug Administration’s (FDA’s) approval for all indications receiving accelerated approval from 2009-2018.

Human ZNF648 is a novel poly C-terminal C2H2 zinc finger (ZnF) protein identified amongst the most dysregulated proteins in erythroid cells differentiated from induced pluripotent stem cells. Its nuclear localization and structure indicate it is likely a DNA-binding protein. Using a combination of ZNF648 overexpression in an induced pluripotent stem cells line and primary adult erythroid cells, ZNF648 knockdown in primary adult erythroid cells and megakaryocytes, comparative proteomics and transcriptomics we show that ZNF648 is required for both erythroid and megakaryocyte differentiation. Orthologues of ZNF648 were detected across Mammals, Reptilia, Actinopterygii, in some Aves, Amphibia and Coelacanthiformes suggesting the gene originated in the common ancestor of Osteichthyes (Euteleostomi or bony fish). Conservation of the C-terminal ZnF domain is higher, with some variation in ZnF number but a core of at least six ZnF conserved across all groups, with the N-terminus recognisably similar within but not between major lineages. This suggests the N-terminus of ZNF648 evolves faster than the C-terminus, however this is not due to exon-shuffling as the entire coding region of ZNF648 is within a single exon. As for other such transcription factors, the N-terminus likely carries out regulatory functions, but showed no sequence similarity to any known domains. The greater functional constraint on the ZnF domain suggests ZNF648 binds at least some similar regions of DNA in the different organisms. However, divergence of the N-terminal region may enable differential expression, allowing adaptation of function in the different organisms.

The Mi(a+) GP(B-A-B) hybrid phenotypes occur with a prevalence of 2%-23% across Southeast Asia. While the s antigen is alleged to be altered, no evidence for specific variants is known. Screening using a monoclonal IgM anti-s mistyped six S-s+ RBC units as S-s-. Further, alloanti-s was identified in an S+s+ patient. Our objective was to investigate the s antigen further. DNA from 63 Thai blood donor samples PCR-positive for a GYP(B-A-B) hybrid was sequenced with primers spanning GYPB exons 3-4. Flow cytometry was used for semiquantitative analysis of s expression and correlated with the glycophorin genotype. DNA sequencing showed that GYP*Mur was carried by 56/63 samples (88·9%) of which 5/56 lacked normal GYPB: three of these were GYP*Mur homozygotes, one was a compound heterozygote carrying GYP*Mur and a GYP*Bun-like allele (designated GYP*Thai), and the fifth sample carried GYP*Mur and another GYP*Bun-like allele. Seven samples (7/63) were GYP*Thai heterozygotes. IgM monoclonal anti-s (P3BER) did not react with the s antigen carried by GP.Mur or GP.Bun, whereas two IgG anti-s showed enhanced reactivity. We confirmed that GYP*Mur is the most frequent variant in Thai blood donors and also identified GYP*Thai with a frequency of 1·1%. We showed that s antigen on Mi(a+) GP(B-A-B) hybrids is qualitatively altered and should be considered when selecting reagents for phenotyping where such hybrids are prevalent, endemically and in blood centres worldwide.

BackgroundPluripotent stem cells are attractive progenitor cells for the generation of erythroid cells in vitro as have expansive proliferative potential. However, although embryonic (ESC) and induced pluripotent (iPSC) stem cells can be induced to undergo erythroid differentiation, the majority of cells fail to enucleate and the molecular basis of this defect is unknown. One protein that has been associated with the initial phase of erythroid cell enucleation is the intermediate filament vimentin, with loss of vimentin potentially required for the process to proceed.MethodsIn this study, we used our established erythroid culture system along with western blot, PCR and interegation of comparative proteomic data sets to analyse the temporal expression profile of vimentin in erythroid cells differentiated from adult peripheral blood stem cells, iPSC and ESC throughout erythropoiesis. Confocal microscopy was also used to examine the intracellular localisation of vimentin.ResultsWe show that expression of vimentin is turned off early during normal adult erythroid cell differentiation, with vimentin protein lost by the polychromatic erythroblast stage, just prior to enucleation. In contrast, in erythroid cells differentiated from iPSC and ESC, expression of vimentin persists, with high levels of both mRNA and protein even in orthochromatic erythroblasts. In the vimentin-positive iPSC orthochromatic erythroblasts, F-actin was localized around the cell periphery; however, in those rare cells captured undergoing enucleation, vimentin was absent and F-actin was re-localized to the enucleosome as found in normal adult orthrochromatic erythroblasts.ConclusionAs both embryonic and adult erythroid cells loose vimentin and enucleate, retention of vimentin by iPSC and ESC erythroid cells indicates an intrinsic defect. By analogy with avian erythrocytes which naturally retain vimentin and remain nucleated, retention in iPSC- and ESC-derived erythroid cells may impede enucleation. Our data also provide the first evidence that dysregulation of processes in these cells occurs from the early stages of differentiation, facilitating targeting of future studies.

A water-soluble TPE-based AIEgen (TPE-diBuS) was developed for organic-solvent-free detection of Al3+ ions and its wash-free cell imaging. The TPE-diBuS-Al ensemble was used for the detection of F− ions and DNA tracking.

The stabilization and transport of low-solubility drugs, by encapsulation in nanoscopic delivery vectors (nanovectors), is a key paradigm in nanomedicine. However, the problems of carrier toxicity, specificity, and producibility create a bottleneck in the development of new nanomedical technologies. Copolymeric nanoparticles are an excellent platform for nanovector engineering due to their structural versatility; however, conventional fabrication processes rely upon harmful chemicals that necessitate purification. In engineering a more robust (copolymeric) nanovector platform, it is necessary to reconsider the entire process from copolymer synthesis through self-assembly and functionalization. To this end, a process is developed whereby biodegradable copolymers of poly(ethylene glycol)-block-poly(trimethylene carbonate), synthesized via organocatalyzed ring-opening polymerization, undergo assembly into highly uniform, drug-loaded micelles without the use of harmful solvents or the need for purification. The direct hydration methodology, employing oligo(ethylene glycol) as a nontoxic dispersant, facilitates rapid preparation of pristine, drug-loaded nanovectors that require no further processing. This method is robust, fast, and scalable. Utilizing parthenolide, an exciting candidate for treatment of acute lymphoblastic leukemia (ALL), discrete nanovectors are generated that show strikingly low carrier toxicity and high levels of specific therapeutic efficacy against primary ALL cells (as compared to normal hematopoietic cells).

Current therapies for childhood T-cell acute lymphoblastic leukemia have increased survival rates to above 85% in developed countries. Unfortunately, some patients fail to respond to therapy and many suffer from serious side effects, highlighting the need to investigate other agents to treat this disease. Parthenolide, a nuclear factor kappa (κ)B inhibitor and reactive oxygen species inducer, has been shown to have excellent anti-cancer activity in pediatric leukemia xenografts, with minimal effects on normal hemopoietic cells. However, some leukemia initiating cell populations remain resistant to parthenolide. This study examined mechanisms for this resistance, including protective effects conferred by bone marrow stromal components. T-cell acute leukemia cells co-cultured with mesenchymal stem cells demonstrated significantly enhanced survival against parthenolide (73±11%) compared to cells treated without mesenchymal stem cell support (11±9%). Direct cell contact between mesenchymal cells and leukemia cells was not required to afford protection from parthenolide. Mesenchymal stem cells released thiols and protected leukemia cells from reactive oxygen species stress, which is associated with parthenolide cytotoxicity. Blocking cystine uptake by mesenchymal stem cells, using a small molecule inhibitor, prevented thiol release and significantly reduced leukemia cell resistance to parthenolide. These data indicate it may be possible to achieve greater toxicity to childhood T-cell acute lymphoblastic leukemia by combining parthenolide with inhibitors of cystine uptake.