Inversion recovery ultrashort echo time imaging of ultrashort T2 tissue components in ovine brain at 3 T: a sequential D2O exchange study

Inversion recovery ultrashort echo time (IR‐UTE) imaging holds the potential to directly characterize MR signals from ultrashort T₂ tissue components (STCs), such as collagen in cartilage and myelin in brain. The application of IR‐UTE for myelin imaging has been challenging because of the high water content in brain and the possibility that the ultrashort T₂* signals are contaminated by water protons, including those associated with myelin sheaths. This study investigated such a possibility in an ovine brain D₂O exchange model and explored the potential of IR‐UTE imaging for the quantification of ultrashort T₂* signals in both white and gray matter at 3 T. Six specimens were examined before and after sequential immersion in 99.9% D₂O. Long T₂ MR signals were measured using a clinical proton density‐weighted fast spin echo (PD‐FSE) sequence. IR‐UTE images were first acquired with different inversion times to determine the optimal inversion time to null the long T₂ signals (TI_null). Then, at this TI_null, images with echo times (TEs) of 0.01–4 ms were acquired to measure the T₂* values of STCs. The PD‐FSE signal dropped to near zero after 24 h of immersion in D₂O. A wide range of TI_null values were used at different time points (240–330 ms for white matter and 320–350 ms for gray matter at TR = 1000 ms) because the T₁ values of the long T₂ tissue components changed significantly. The T₂* values of STCs were 200–300 μs in both white and gray matter (comparable with the values obtained from myelin powder and its mixture with D₂O or H₂O), and showed minimal changes after sequential immersion. The ultrashort T₂* signals seen on IR‐UTE images are unlikely to be from water protons as they are exchangeable with deuterons in D₂O. The source is more likely to be myelin itself in white matter, and might also be associated with other membranous structures in gray matter.     

A systematic review investigating psychosocial aspects of egg sharing in the United Kingdom and their potential effects on egg donation numbers

This review aims to provide an up-to-date knowledge of the psychosocial aspects of egg donation from the perspectives of the egg share donor and their recipient. It explores the motives, experiences and attitudes of egg sharers and their views towards donor anonymity and disclosure. Conclusions are made on how these findings can guide clinical practice and improve egg sharing numbers. A systematic search of peer-reviewed journals of four computerized databases was undertaken. Eleven studies were included in the review. Psychosocial aspects towards donation were positive from the egg share donor and recipient. Concerns raised were whether participating in the egg sharing scheme would impact on their success rates, as well as frustration expressed by a minority regarding the lack of knowledge of egg sharing outside of fertility clinics. The 2005 legislative changes in the UK have not caused the anticipated dramatic decrease in egg donation; however, oocyte donation still falls short of demand. Egg sharing provides a practical option for more patients to access IVF, whilst also providing more donor oocytes. Improved information provision will result in greater awareness of egg sharing, with the potential to recruit more donors and meet the needs of recipients currently on long waiting lists.     

VALIDITY AND USE OF A NON-PARALLEL INSULIN ASSAY FOR PHARMACOKINETIC STUDIES OF THE RAPID-ACTING INSULIN ANALOGUE,INSULIN ASPART

A radioimmunoassay (RIA) for insulin was validated for reliable measurement of the human insulin analogue, insulin aspart, by correction of non-linear measurements. Specificity was equivalent for several species of insulin, except insulin aspart. A non-linear hyperbolic model fitted insulin aspart with a correction formula for non-linearity of: z = 1503y/(1398 - y), where y denotes measured concentration and z denotes true concentration.

Matrix-effects were insignificant for human, porcine, and canine heparin-plasma and for human and porcine serum. The coefficient of variation was below 15% for 80–800 pmol/L human and porcine insulin and for 80–600 pmol/L insulin aspart. The limit of detection for insulin aspart was 11.5 pmol/L with a lower limit of quantification of 17.5 pmol/L. Dilution of serum with Pharmacia dilution media introduced no significant error. In conclusion, this paper demonstrates that a non-parallel radioimmunoassay can be used to estimate accurate concentrations of insulin aspart.     

Novel aspects of Kindlin‐3 function in humans based on a new case of leukocyte adhesion deficiency III

Summary. Background: Kindlin‐3 is a novel integrin activator in hematopoietic cells, and its deficiency leads to immune problems and severe bleeding, known as leukocyte adhesion deficiency III (LAD‐III). Our current understanding of Kindlin‐3 function primarily relies on analysis of animal models or cell lines. Objectives: To understand the functions of Kindlin‐3 in human primary blood cells. Patients/Methods: We analyzed primary and immortalized hematopoietic cells obtained from a new LAD‐III patient with immune problems, bleeding, a history of anemia, and abnormally shaped red blood cells. Results: The patient’s white blood cells (WBCs) and platelets showed defects in agonist‐induced integrin activation and botrocetin‐induced platelet agglutination. Primary leukocytes from this patient exhibited abnormal activation of β₁ integrin. Integrin activation defects were responsible for the observed deficiency in the botrocetin‐induced platelet response. Analysis of patient genomic DNA revealed a novel mutation in the Kindlin3 gene. The mutation abolished Kindlin‐3 expression in primary WBCs and platelets, owing to abnormal splicing. Kindlin‐3 is expressed in red blood cells (RBCs), and its deficiency is proposed to lead to abnormally shaped RBCs. Immortalized patient WBCs expressed a truncated form of Kindlin‐3 that was not sufficient to support integrin activation. Expression of Kindlin‐3 cDNA in immortalized patient WBCs rescued integrin activation defects, whereas overexpression of the truncated form did not. Conclusions: Kindlin‐3 deficiency impairs integrin function, including activation of β₁ integrin. Abnormalities in glycoprotein Ib–IX function in Kindlin‐3‐deficient platelets are secondary to integrin defects. The region of Kindlin‐3 encoded by exon 11 is crucial for its ability to activate integrins in humans.     

Recognition of lysozyme using surface imprinted bacterial cellulose nanofibers

Here, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability.