Patient blood management: A solution for South Africa.

For more than 70 years the default therapy for anaemia and blood loss was mostly transfusion. Accumulating evidence demonstrates a significant dose-dependent relationship between transfusion and adverse outcomes. This and other transfusion-related challenges led the way to a new paradigm. Patient blood management (PBM) is the application of evidence-based practices to optimise patient outcomes by managing and preserving the patient's own blood. 'Real-world' studies have shown that PBM improves patient outcomes and saves money. The prevalence of anaemia in adult South Africans is 31% in females and 17% in males. Improving the management of anaemia will firstly improve public health, secondly relieve the pressure on the blood supply, and thirdly improve the productivity of the nation's workforce. While high-income countries are increasingly implementing PBM, many middle- and low-income countries are still trying to upscale their transfusion services. The implementation of PBM will improve South Africa's health status while saving costs.

3D-printed poly(vinylidene fluoride)/carbon nanotube composites as a tunable, low-cost chemical vapour sensing platform.

We report the production of flexible, highly-conductive poly(vinylidene fluoride) (PVDF) and multi-walled carbon nanotube (MWCNT) composites as filament feedstock for 3D printing. This account further describes, for the first time, fused deposition modelling (FDM) derived 3D-printed objects with chemiresistive properties in response to volatile organic compounds. The typically prohibitive thermal expansion and die swell characteristics of PVDF were minimized by the presence of MWCNTs in the composites enabling straightforward processing and printing. The nanotubes form a dispersed network as characterized by helium ion microscopy, contributing to excellent conductivity (∼3 × 10-2 S cm-1). The printed composites contain little residual metal particulate relative to parts from commercial PLA-nanocomposite material visualized by micro-X-ray computed tomography (µ-CT) and corroborated with thermogravimetric analysis. Printed sensing strips, with MWCNT loadings up to 15% mass, function as reversible vapour sensors with the strongest responses arising with organic compounds capable of readily intercalating and subsequently swelling the PVDF matrix (acetone and ethyl acetate). A direct correlation between MWCNT concentration and resistance change was also observed, with larger responses (up to 161% after 3 minutes) being generated with decreased MWCNT loadings. These findings highlight the utility of FDM printing in generating low-cost sensors that respond strongly and reproducibly to target vapours. Furthermore, the sensors can be easily printed in different geometries, expanding their utility to wearable form factors. The proposed formulation strategy may be tailored to sense diverse sets of vapour classes through structural modification of the polymer backbone and/or functionalization of the nanotubes within the composite.

False-negative rate, limit of detection and recovery efficiency performance of a validated macrofoam-swab sampling method for low surface concentrations of Bacillus anthracis Sterne and Bacillus atrophaeus spores.

AIMS: We sought to evaluate the effects of Bacillus species, low surface concentrations, and surface material on recovery efficiency (RE), false-negative rate (FNR) and limit of detection for recovering Bacillus spores using a validated macrofoam-swab sampling procedure. METHODS AND RESULTS: The performance of a macrofoam-swab sampling method was evaluated using Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus Nakamura (BG) spores applied at nine low target surface concentrations (2 to 500 CFU per plate or coupon) to positive-control plates and test coupons (25·8064 cm(2) ) of four surface materials (glass, stainless steel, vinyl tile and plastic). The Bacillus species and surface material had statistically significant effects on RE, but surface concentration did not. Mean REs were the lowest for vinyl tile (50·8% with BAS and 40·2% with BG) and the highest for glass (92·8% with BAS and 71·4% with BG). FNR values (which ranged from 0 to 0·833 for BAS and from 0 to 0·806 for BG) increased as surface concentration decreased in the range tested. Surface material also had a statistically significant effect on FNR, with FNR the lowest for glass and highest for vinyl tile. Finally, FNR tended to be higher for BG than for BAS at lower surface concentrations, especially for glass. CONCLUSIONS: Concentration and surface material had significant effects on FNR, with Bacillus species having a small effect. Species and surface material had significant effects on RE, with surface concentration having a nonsignificant effect. SIGNIFICANCE AND IMPACT OF THE STUDY: The results provide valuable information on the performance of the macrofoam-swab method for low surface concentrations of Bacillus spores, which can be adapted to assess the likelihood that there is no contamination when all macrofoam-swab samples fail to detect B. anthracis.

Randomized trial of lamivudine versus hepatitis B immunoglobulin for long-term prophylaxis of hepatitis B recurrence after liver transplantation.

BACKGROUND/AIMS: The long-term prophylaxis of hepatitis B after liver transplantation requires further optimization. In a randomized trial we investigated a regimen where the initially given hepatitis B immunoglobulin (HBIg) is replaced by long-term lamivudine treatment. METHODS: Twenty-four liver transplant recipients (all HBsAg-positive/HBV DNA-negative before transplantation), who had received HBIg for at least 6 months without HBV recurrence, were randomized to receive lamivudine (n = 12) or HBIg (n = 12) for 52 weeks. The efficacy criteria involved seronegativity for HBsAg and undetectable HBsAg/ HBcAg in the liver. RESULTS: Twenty-one of 24 patients completed the study without hepatitis B virus (HBV) recurrence (11 on HBIg, ten on lamivudine), while three patients became HBsAg-positive. Amongst those without HBV recurrence HBV DNA was detectable only by polymerase chain reaction, intermittently in serum and lymphocytes, and in liver specimens from six of eight patients receiving HBIg and five of seven receiving lamivudine. YMDD variant was found in four cases with no viral antigen expression. Eight patients continued lamivudine after the study and during an additional 6-22 months remained HBsAg-negative with normal graft function. CONCLUSIONS: Substitution of HBIg with lamivudine is effective for prevention of HBV recurrence in low-risk liver transplant recipients and offers a convenient and cost-effective alternative for long-term HBV prophylaxis.