Osteoclast-specific Plastin 3 knockout in mice fail to develop osteoporosis despite dramatic increased osteoclast resorption activity.

PLS3 loss-of-function mutations in humans and mice cause X-linked primary osteoporosis. However, it remains largely unknown how PLS3 mutations cause osteoporosis and which function PLS3 plays in bone homeostasis. A recent study showed that ubiquitous Pls3 KO in mice results in osteoporosis. Mainly osteoclasts were impacted in their function However, it has not been proven if osteoclasts are the major cell type affected and responsible for osteoporosis development in ubiquitous Pls3 KO mice. Here, we generated osteoclast-specific Pls3 KO mice. Additionally, we developed a novel polyclonal PLS3 antibody that showed specific PLS3 loss in immunofluorescence staining of osteoclasts in contrast to previously available antibodies against PLS3, which failed to show PLS3 specificity in mouse cells. Moreover, we demonstrate that osteoclast-specific Pls3 KO causes dramatic increase in resorptive activity of osteoclasts in vitro. Despite these findings, osteoclast-specific Pls3 KO in vivo failed to cause any osteoporotic phenotype in mice as proven by micro-CT and three-point bending test. This demonstrates that the pathomechanism of PLS3-associated osteoporosis is highly complex and cannot be reproduced in a system singularly focused on one cell type. Thus, the loss of PLS3 in alternative bone cell types might contributes to the osteoporosis phenotype in ubiquitous Pls3 KO mice.

Unexpectedly low oxygen saturation in a child with a variant hemoglobin.

We report a child with an unexpected low saturation reading despite normal values having been recorded soon after birth. A family history of Rothschild hemoglobin variant affecting the father was obtained. Saturation values improved with oxygen and anesthesia was uneventful. The development of low saturation values as the child matures is explained, and management for future health presentations outlined.

Ileocaecal Intussusception Due to Burkitt Lymphoma: A Surgical and Haematological Emergency.

Intussusception is the protrusion and invagination of a segment of the bowel, referred to as the intussusceptum, into another adjacent segment known as the intussuscipiens. The age range during which intussusception is most observed in children is between three and 18 months. Unlike intussusceptions in children, where the cause is often idiopathic, a specific underlying factor is discernible in a significant majority of cases among adults. In this article, we will present a case of intussusception in an adolescent caused by Burkitt lymphoma.

Mapping of the amniotic fluid proteome of fetuses with congenital anomalies of the kidney and urinary tract identifies plastin 3 as a protein involved in glomerular integrity.

Congenital anomalies of the kidney and the urinary tract (CAKUT) are the first cause of chronic kidney disease in childhood. Several genetic and environmental origins are associated with CAKUT, but most pathogenic pathways remain elusive. Considering the amniotic fluid (AF) composition as a proxy for fetal kidney development, we analyzed the AF proteome from non-severe CAKUT (n = 19), severe CAKUT (n = 14), and healthy control (n = 22) fetuses using LC-MS/MS. We identified 471 significant proteins that discriminated the three AF groups with 81% precision. Among them, eight proteins independent of gestational age (CSPG4, LMAN2, ENDOD1, ANGPTL2, PRSS8, NGFR, ROBO4, PLS3) were associated with both the presence and the severity of CAKUT. Among those, five were part of a protein-protein interaction network involving proteins previously identified as being potentially associated with CAKUT. The actin-bundling protein PLS3 (plastin 3) was the only protein displaying a gradually increased AF abundance from control, via non-severe, to severe CAKUT. Immunohistochemistry experiments showed that PLS3 was expressed in the human fetal as well as in both the fetal and the postnatal mouse kidney. In zebrafish embryos, depletion of PLS3 led to a general disruption of embryonic growth including reduced pronephros development. In postnatal Pls3-knockout mice, kidneys were macroscopically normal, but the glomerular ultrastructure showed thickening of the basement membrane and fusion of podocyte foot processes. These structural changes were associated with albuminuria and decreased expression of podocyte markers including Wilms' tumor-1 protein, nephrin, and podocalyxin. In conclusion, we provide the first map of the CAKUT AF proteome that will serve as a reference for future studies. Among the proteins strongly associated with CAKUT, PLS3 did surprisingly not specifically affect nephrogenesis but was found as a new contributor in the maintenance of normal kidney function, at least in part through the control of glomerular integrity. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Adherence to a selective antenatal haemoglobinopathy screening policy within a tertiary level obstetric unit in Australia.

BACKGROUND: Haemoglobinopathies represent the most common single gene disorder worldwide; however, significant centre to centre variations in antenatal screening practices exist. AIMS: To assess performance of a selective antenatal haemoglobinopathy screening policy within a presumed low-prevalence Australian population. Primary outcome was the failure to screen rate for women with at least one identifiable risk factor. Secondary outcomes included outcomes of maternal screening and rates, gestations and outcomes of paternal, prenatal and neonatal testing. MATERIALS AND METHODS: A two-year retrospective cohort study identifying all women attending for public antenatal care with at least one identifiable risk factor for haemoglobinopathy. RESULTS: At least one risk factor for haemoglobinopathy was identified in 8.8% of the entire pregnant cohort; however, the failure to screen rate was high at 83.7% overall. Screening was significantly more likely to be undertaken in multiparous women, those with multiple risk factors and women originating from the Middle East. Twenty percent of screened women returned an abnormal result; however, this led to paternal haemoglobinopathy screening in only 66.6%. Where completed, the addition of partner screening reclassified offspring to low-risk status in 85.7% of cases. CONCLUSIONS: This study demonstrates an 83.7% screen failure rate within a selective screening model raising concerns regarding the clinical utility and health equity of this approach. This major drawback of selective screening suggests that institution of a universal antenatal screening system for haemoglobinopathies, even in anticipated low-prevalence areas, will improve detection rates and ensure families receive appropriate and timely counselling.

Viscoelastic haemostatic assays and fibrinogen in paediatric acute traumatic coagulopathy: A comprehensive review.

OBJECTIVE: Haemorrhage in paediatric trauma remains a significant cause of morbidity and mortality. Over recent years there has been increasing attention to the role of fibrinogen in traumatic haemorrhage and the association of low fibrinogen levels with poor patient outcomes. In addition, there has been a move towards using viscoelastic haemostatic assays (VHAs) to rapidly assess coagulation status and guide clinicians in the replacement of coagulation factors, including fibrinogen. In the paediatric population, there has been limited uptake of these principles and a paucity of data to support a change in practice. This paper summarises the available evidence in the published literature through a systematic review, presented in narrative format. RESULTS: There is limited high-quality prospective data on the use of VHA in the management of acute traumatic coagulopathy in the paediatric population. While the use of fibrinogen early in major haemorrhage is becoming standard practice, there are currently no randomised prospective studies comparing fibrinogen concentrate to cryoprecipitate. CONCLUSIONS: The early identification of hypo-fibrinogenemia and acute traumatic coagulopathy in paediatric trauma using VHA testing and subsequent early fibrinogen replacement with a concentrated off the shelf product is an attractive treatment option. However, there is currently insufficient high-level evidence to support the use of fibrinogen concentrate over cryoprecipitate in the paediatric trauma population. Pilot studies currently under way will go some way to addressing this important knowledge gap, and facilitate the design of larger definitive multi-centre randomised trials.

Embedding best transfusion practice and blood management in neonatal intensive care.

BACKGROUND: Transfusion is a common procedure for neonates receiving intensive care management. Recognising a paucity of patient blood management (PBM) programmes in neonates, we aimed to embed blood management and best transfusion principles in the neonatal intensive care unit (NICU) by aligning local policies, providing targeted education and partnering with parents. METHODS: Practice-based evidence for clinical practice improvement (PBE-CPI) methodology was used. Previous hospital accreditation audits were reviewed and a neonate-specific transfusion audit was developed. Audit was performed at baseline and repeated following the intervention period. NICU clinicians received targeted education in obtaining informed consent, prescription and safe administration of blood components during a 'Blood Month' awareness period. A neonate-specific parent handout about transfusion was developed in partnership with parents. A pilot video demonstrating a shared consent discussion was also developed to assist in the consent process. Parents' knowledge, concerns and feedback regarding transfusion practice was sought at baseline (survey) and on project completion (experience trackers). RESULTS: Neonate-specific baseline transfusion audit showed inconsistent consent, monitoring and documentation processes in neonatal transfusions. Post-targeted education audit showed improvement in these parameters. The targeted PBM and transfusion-related education delivered during 'Blood Month' was well-received by staff. Parents' feedback about the NICU transfusion consenting process was consistently positive. NICU medical and nursing clinicians (n=25) surveyed agreed that the parent handout was well set out, easy to understand and recommended that it be used to complement practice. CONCLUSION: PBE-CPI tools aligned with Australian PBM guidelines for clinicians and parents were well-accepted by clinical stakeholders and were associated with practice improvement in PBM awareness and transfusion consent processes. This PBE-CPI project developed NICU-specific consent information, not previously available, by partnering with parents to ensure quality of care in transfusion practice. Adoption of this also helps to meet accreditation for Australian Blood Management Standards. These strategies and tools translate readily into other NICUs to embed and support best PBM and transfusion practice.

Transfusion-associated circulatory overload in ambulatory patients.

BACKGROUND AND OBJECTIVES: Transfusion-associated circulatory overload is a leading cause of transfusion-related adverse events. The frequency and risks for transfusion-associated circulatory overload in ambulatory haematology patients are not known. MATERIALS AND METHODS: A retrospective cohort analysis of ambulatory patients transfused in a tertiary haematology centre, using medical records and an electronic transfusion database, was undertaken between January and December 2014. Variables studied included age, gender, diagnosis, heart failure, kidney disease and details of transfusions. Transfusion-associated circulatory overload was defined according to proposed International Society of Blood Transfusion criteria. Patients with clinical evidence of hypervolaemia, not meeting the TACO definition and/or who were prescribed otherwise unscheduled diuretic agent, were collectively deemed to be at 'risk of clinically significant hypervolaemia' (ROCSH). RESULTS: In the study period, 93 ambulatory patients (male = 49, female = 44, mean age = 75·89 ± 11·37 years) attended 715 transfusion encounters, totalling 1536 packed red cell units. No cases of TACO occurred whilst 'ROCSH' events occurred in 57/715 (8%) of transfusion encounters. In a univariate model, age was significantly associated with 'ROCSH', odds ratio = 1·05 (P = 0·017 95%, CI 1·01-1·09) and no factors were significant on multivariate analysis. CONCLUSIONS: Transfusion-associated circulatory overload occurs infrequently haematology patients receiving ambulatory blood transfusions. To our knowledge, this is the first study to report on occurrence and risk factors for circulatory overload in ambulatory transfusions. This study provides vital baseline data for future prospective studies on this important aspect of haemovigilance.

Plastin 3 influences bone homeostasis through regulation of osteoclast activity.

Over 200 million people suffer from osteoporosis worldwide, one third of which will develop osteoporotic bone fractures. Unfortunately, no effective cure exists. Mutations in plastin 3 (PLS3), an F-actin binding and bundling protein, cause X-linked primary osteoporosis in men and predisposition to osteoporosis in postmenopausal women. Moreover, the strongest association so far for osteoporosis in elderly women after menopause was connected to a rare SNP in PLS3, indicating a possible role of PLS3 in complex osteoporosis as well. Interestingly, 5% of the general population are overexpressing PLS3, with yet unknown consequences. Here, we studied ubiquitous Pls3 knockout and PLS3 overexpression in mice and demonstrate that both conditions influence bone remodeling and structure: while Pls3 knockout mice exhibit osteoporosis, PLS3 overexpressing mice show thickening of cortical bone and increased bone strength. We show that unbalanced PLS3 levels affect osteoclast development and function, by misregulating the NFκB pathway. We found upregulation of RELA (NFκB subunit p65) in PLS3 overexpressing mice-known to stimulate osteoclastogenesis-but strikingly reduced osteoclast resorption. We identify NFκB repressing factor (NKRF) as a novel PLS3 interactor, which increasingly translocates to the nucleus when PLS3 is overexpressed. We show that NKRF binds to the NFκB downstream target and master regulator of osteoclastogenesis nuclear factor of activated T cells 1 (Nfatc1), thereby reducing its transcription and suppressing osteoclast function. We found the opposite in Pls3 knockout osteoclasts, where decreased nuclear NKRF augmented Nfatc1 transcription, causing osteoporosis. Regulation of osteoclastogenesis and bone remodeling via the PLS3-NKRF-NFκB-NFATC1 axis unveils a novel possibility to counteract osteoporosis.

Zeroing in on red blood cell unit expiry.

BACKGROUND: Expiry of red blood cell (RBC) units is a significant contributor to wastage of precious voluntary donations. Effective strategies aimed at optimal resource utilization are required to minimize wastage. STUDY DESIGN AND METHODS: This retrospective study analyzed the strategic measures implemented to reduce expiry of RBC units in an Australian tertiary regional hospital. The measures, which included inventory rearrangement, effective stock rotation, and the number of emergency courier services required during a 24-month period, were evaluated. RESULTS: There was no wastage of RBC units due to expiry over the 12 months after policy changes. Before these changes, approximately half of RBC wastage (261/511) was due to expiry. The total number of transfusions remained constant in this period and there was no increase in the use of emergency couriers. Policy changes implemented were decreasing the RBC inventory level by one-third and effective stock rotation and using a computerized system to link the transfusion services across the area. Effective stock rotation resulted in a reduction in older blood (>28 days) received in the main laboratory rotated from peripheral hospitals, down from 6%-41% to 0%-2.5%. CONCLUSION: Age-related expiry of blood products is preventable and can be significantly reduced by improving practices in the pathology service. This study provides proof of principle for "zero tolerance for RBC unit expiry" across a large networked blood banking service.

Development of novel PP2A activators for use in the treatment of acute myeloid leukaemia.

AAL(S), the chiral deoxy analog of the FDA approved drug FTY720, has been shown to inhibit proliferation and apoptosis in several cancer cell lines. It has been suggested that it does this by activating protein phosphatase 2A (PP2A). Here we report the synthesis of new cytotoxic analogs of AAL(S) and the evaluation of their cytotoxicity in two myeloid cell lines, one of which is sensitive to PP2A activation. We show that these analogs activate PP2A in these cells supporting the suggested mechanism for their cytotoxic properties. Our findings identify key structural motifs required for anti-cancer effects.

A perspective on the developmental toxicity of inhaled nanoparticles.

This paper aimed to clarify whether maternal inhalation of engineered nanoparticles (NP) may constitute a hazard to pregnancy and fetal development, primarily based on experimental animal studies of NP and air pollution particles. Overall, it is plausible that NP may translocate from the respiratory tract to the placenta and fetus, but also that adverse effects may occur secondarily to maternal inflammatory responses. The limited database describes several organ systems in the offspring to be potentially sensitive to maternal inhalation of particles, but large uncertainties exist about the implications for embryo-fetal development and health later in life. Clearly, the potential for hazard remains to be characterized. Considering the increased production and application of nanomaterials and related consumer products a testing strategy for NP should be established. Due to large gaps in data, significant amounts of groundwork are warranted for a testing strategy to be established on a sound scientific basis.

Comprehensive In Vitro Toxicity Testing of a Panel of Representative Oxide Nanomaterials: First Steps towards an Intelligent Testing Strategy.

Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO2 NMs with different surface chemistry - hydrophilic (NM-103) and hydrophobic (NM-104), two forms of ZnO - uncoated (NM-110) and coated with triethoxycapryl silane (NM-111) and two SiO2 NMs produced by two different manufacturing techniques - precipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO2>TiO2). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO2 and SiO2, while the embryonic stem cell test (EST) classified the TiO2 NMs as potentially 'weak-embryotoxic' and ZnO and SiO2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO2 NM-203 > SiO2 NM-200 > TiO2 NM-104 > TiO2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO2 displayed higher toxicity compared with ZnO and SiO2. Importantly, the in vitro methodology applied could identify cell- and NM-specific responses, with a low variability observed between different test assays. Overall, this testing approach, based on a battery of cellular systems and test assays, complemented by an exhaustive physico-chemical characterization of NMs, could be deployed for the development of an ITS suitable for risk assessment of NMs. This study also provides a rich source of data for modeling of NM effects.

Analysis of the occupational, consumer and environmental exposure to engineered nanomaterials used in 10 technology sectors.

Humans and the environment can come into contact with nanomaterials through a wide range of applications during all stages of the life cycle of nanoproducts. The aim of this commentary is to present an assessment of the potential for exposure and thus identify possible environmental, health and safety (EHS) issues for nanomaterials used in 10 technology sectors. We analysed all life cycle stages with regard to potential for exposure of workers, consumers/patients, and the environment. A wide variety of nanomaterials are used of which many have negligible potential for exposure, while others have medium or even high potential for exposure. Based on the likelihood of exposure, it appears that in general most attention should be paid to the agrifood, chemistry/materials, textiles and health sectors; and less to the information and communication technology (ICT), security and energy sectors. Toxicity and exposure are both important; however, the EHS impact of nanomaterials is always dependent on their particular use.

Applications and implications of nanotechnologies for the food sector.

A review of current and projected nanotechnology-derived food ingredients, food additives and food contact materials is presented in relation to potential implications for consumer safety and regulatory controls. Nanotechnology applications are expected to bring a range of benefits to the food sector, including new tastes, textures and sensations, less use of fat, enhanced absorption of nutrients, improved packaging, traceability and security of food products. The review has shown that nanotechnology-derived food and health food products are set to grow worldwide and, moreover, a variety of food ingredients, additives, carriers for nutrients/supplements and food contact materials is already available in some countries. The current level of applications in the European food sector is at an elementary stage; however, it is widely expected that more and more products will be available in the EU over the coming years. The toxicological nature of hazard, likelihood of exposure and risk to consumers from nanotechnology-derived food/food packaging are largely unknown and this review highlights major gaps in knowledge that require further research. A number of uncertainties and gaps in relevant regulatory frameworks have also been identified and ways of addressing them proposed.