Prioritise safety, optimise success! Return to rugby postpartum.

Pregnancy and childbirth involve substantial physical, physiological and psychological changes. As such, postpartum rugby players should be supported and appropriately prepared to return to the demands of rugby alongside the additional demands of motherhood. This review aims to discuss specific perinatal considerations that inform a rugby player's readiness to return-to-sport postpartum and present an approach to rehabilitation. Before engaging in full rugby training and matchplay, postpartum players should have progressed through the initial phases of rehabilitation and graded sports-specific training to prepare them for the loads they will be exposed to. Additional rehabilitation considerations include minimising deconditioning during pregnancy; medical concerns; the abdominal wall; the pelvic floor; perinatal breast changes, breastfeeding and risk of contact breast injury; body mass; nutritional requirements; hormonal considerations; athlete identity and psychological considerations; joining team training; return to contact and tackle training; evaluating player load tolerance and future research, policy and surveillance needs. A whole-systems, biopsychosocial approach following an evidence informed return-to-sport framework is recommended when rehabilitating postpartum rugby players. Health and exercise professionals are encouraged to use the perinatal-specific recommendations in this review to guide the development of postpartum rehabilitation protocols and resources.

Correction to: Heparin resistance in COVID­19 patients in the intensive care unit.

In the original publication of this article, one of the co-author name "D. de Monteverde-Robb" was inadvertently mentioned as "R. de Monteverde-Robb". The correct author name is "D. de Monteverde-Robb". This error has been corrected with this erratum.

Heparin resistance in COVID-19 patients in the intensive care unit.

Patients with COVID-19 have a coagulopathy and high thrombotic risk. In a cohort of 69 intensive care unit (ICU) patients we investigated for evidence of heparin resistance in those that have received therapeutic anticoagulation. 15 of the patients have received therapeutic anticoagulation with either unfractionated heparin (UFH) or low molecular weight heparin (LMWH), of which full information was available on 14 patients. Heparin resistance to UFH was documented in 8/10 (80%) patients and sub-optimal peak anti-Xa following therapeutic LMWH in 5/5 (100%) patients where this was measured (some patients received both anticoagulants sequentially). Spiking plasma from 12 COVID-19 ICU patient samples demonstrated decreased in-vitro recovery of anti-Xa compared to normal pooled plasma. In conclusion, we have found evidence of heparin resistance in critically unwell COVID-19 patients. Further studies investigating this are required to determine the optimal thromboprophylaxis in COVID-19 and management of thrombotic episodes.

Transforming growth factor-beta signaling network regulates plasticity and lineage commitment of lung cancer cells.

Identification of target cells in lung tumorigenesis and characterization of the signals that control their behavior is an important step toward improving early cancer diagnosis and predicting tumor behavior. We identified a population of cells in the adult lung that bear the EpCAM+CD104+CD49f+CD44+CD24loSCA1+ phenotype and can be clonally expanded in culture, consistent with the properties of early progenitor cells. We show that these cells, rather than being restricted to one tumor type, can give rise to several different types of cancer, including adenocarcinoma and squamous cell carcinoma. We further demonstrate that these cells can be converted from one cancer type to the other, and this plasticity is determined by their responsiveness to transforming growth factor (TGF)-beta signaling. Our data establish a mechanistic link between TGF-beta signaling and SOX2 expression, and identify the TGF-beta/SMAD/SOX2 signaling network as a key regulator of lineage commitment and differentiation of lung cancer cells.

Ron tyrosine kinase receptor synergises with EGFR to confer adverse features in head and neck squamous cell carcinoma.

BACKGROUND: Although EGFR inhibitors have shown some success in the treatment of head and neck squamous cell carcinomas (HNSCCs), the results are not dramatic. Additional molecular targets are urgently needed. We previously showed that the loss of Ron receptor activity significantly slowed squamous tumour growth and progression in a murine model. Based on these data, we hypothesised that Ron expression confers an aggressive phenotype in HNSCCs. We prospectively collected and evaluated 154 snap-frozen, primary HNSCCs for Ron and EGFR expression/phosphorylation. Biomarker correlation with clinical, pathological and outcome data was performed. The biological responses of HNSCC cell lines to Ron knockdown, its activation and the biochemical interaction between Ron and EGFR were examined. RESULTS: We discovered that 64.3% (99 out of 154) HNSCCs expressed Ron. The carcinomas expressed exclusively mature functional Ron, whereas the adjacent nonmalignant epithelium expressed predominantly nonfunctional Ron precursor. There was no significant association between Ron and sex, tumour differentiation, perineural/vascular invasion or staging. However, patients with Ron+HNSCC were significantly older and more likely to have oropharyngeal tumours. Ron+HNSCC also had significantly higher EGFR expression and correlated strongly with phosphorylated EGFR (pEGFR). Newly diagnosed HNSCC with either Ron/pEGFR or both had lower disease-free survival than those without Ron and pEGFR. Knocking down Ron in SCC9 cells significantly blunted their migratory response to not only the Ron ligand, MSP, but also EGF. Stimulation of Ron in SCC9 cells significantly augmented the growth effect of EGF; the synergistic effect of both growth factors in SCC9 cells was dependent on Ron expression. Activated Ron also interacted with and transactivated EGFR. CONCLUSION: Ron synergises with EGFR to confer certain adverse features in HNSCCs.

Interventional neuroradiological procedures-a review for anaesthetists.

Interventional neuroradiology is a rapidly expanding field, and the complexity and duration of these procedures makes anaesthetic support essential to their success. Such has been the development in this area, that the American Heart Association has published a scientific statement on the indications for these procedures. A detailed understanding of patient pathology, the technical aspects of the interventions and their associated risks, and the remote location in which they are performed are important for providing expert anaesthetic care. The aim of this article is to provide a description and contemporary analysis of the common interventional neuroradiology procedures relevant to the anaesthetist. This article will cover the management of intracranial aneurysms, cerebral vasospasm following intracranial haemorrhage, intracranial and spinal arteriovenous malformations, idiopathic intracranial hypertension, carotid artery stenting, intra-arterial thrombolysis for stroke and endovascular treatment of intracranial atherosclerosis. Protection from ionising radiation and acute kidney injury are also discussed.

The RON receptor tyrosine kinase promotes MSP-independent cell spreading and survival in breast epithelial cells.

The recepteur d'origine nantais (RON) is a receptor tyrosine kinase (RTK) in the scatter factor family, which includes the c-Met receptor. RON exhibits increased expression in a significant number of human breast cancer tissues as well as in many established breast cancer cell lines. Recent studies have indicated that in addition to ligand-dependent signaling events, RON also promotes signals in the absence of its only known ligand, MSP, when expressed in epithelial cells. In this study, we found that when expressed in MCF-10A breast epithelial cells, RON exhibits both MSP-dependent and MSP-independent signaling, which lead to distinct biological outcomes. In the absence of MSP, RON signaling promotes cell survival, increased cell spreading and enhanced migration in response to other growth factors. However, both RON-mediated proliferation and migration require the addition of MSP in MCF-10A cells. Both MSP-dependent and MSP-independent signaling by RON are mediated in part by Src family kinases. These data suggest that RON has two alternative modes of signaling that can contribute to oncogenic behavior in normal breast epithelial cells.

Ski can negatively regulates macrophage differentiation through its interaction with PU.1.

In the hematopoietic cell system, the oncoprotein Ski dramatically affects growth and differentiation programs, in some cases leading to malignant leukemia. However, little is known about the interaction partners or signaling pathways involved in the Ski-mediated block of differentiation in hematopoietic cells. Here we show that Ski interacts with PU.1, a lineage-specific transcription factor essential for terminal myeloid differentiation, and thereby represses PU.1-dependent transcriptional activation. Consistent with this, Ski inhibits the biological function of PU.1 to promote myeloid cells to differentiate into macrophage colony-stimulating factor receptor (M-CSFR)-positive macrophages. Using a Ski mutant deficient in PU.1 binding, we demonstrate that Ski-PU.1 interaction is critical for Ski's ability to repress PU.1-dependent transcription and block macrophage differentiation. Furthermore, we provide evidence that Ski-mediated repression of PU.1 is due to Ski's ability to recruit histone deacetylase 3 to PU.1 bound to DNA. Since inactivation of PU.1 is closely related to the development of myeloid leukemia and Ski strongly inhibits PU.1 function, we propose that aberrant Ski expression in certain types of myeloid cell lineages might contribute to leukemogenesis.

Soluble human leukocyte antigen: a diagnostic indicator of rheumatoid arthritis?

Early stage rheumatoid arthritis (RA) is often difficult to diagnose because initial symptoms are non-specific. To aid diagnosis, suitable serological diagnostic markers are sought. Elevated levels of soluble MHC class II (soluble human leukocyte antigen; sHLA-DR) in human serum have been associated with rheumatoid and 'rheumatoid-like' autoimmune diseases. As a result, sHLA-DR has been suggested as a specific marker of RA. However, reported levels of sHLA-DR in sera of healthy donors vary significantly and the mechanism of release of HLA-DR into serum is poorly understood. Investigations into the diagnostic potential of this molecule necessitate the development of a sensitive and specific sHLA-DR assay. We have investigated multiple ELISA setups to develop such an assay and false positive signal has been carefully removed using a combination of isotype-matched controls and immuno-depletion. sHLA-DR levels in sera of RA patients were not significantly different from those in healthy donors which suggests sHLA-DR has limited utility in the diagnosis of RA. In RA patients, we detected high levels of sHLA-DR in aspirated synovial fluid (SF), but this did not correlate with sHLA-DR levels in serum.

Following the differentiation of human pluripotent stem cells by proteomic identification of biomarkers.

Following the differentiation of cultured stem cells is often reliant on the expression of genes and proteins that provide information on the developmental status of the cell or culture system. There are few molecules, however, that show definitive expression exclusively in a specific cell type. Moreover, the reliance on a small number of molecules that are not entirely accurate biomarkers of particular tissues can lead to misinterpretation in the characterization of the direction of cell differentiation. Here we describe the use of technology that examines the mass spectrum of proteins expressed in cultured cells as a means to identify the developmental status of stem cells and their derivatives in vitro. This approach is rapid and reproducible and it examines the expression of several different biomarkers simultaneously, providing a profile of protein expression that more accurately corresponds to a particular type of cell differentiation.

Inhibition of retinoic acid receptor signaling by Ski in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous disease with multiple different cytogenetic and molecular aberrations contributing to leukemic transformation. We compared gene expression profiles of 4608 genes using cDNA-arrays from 20 AML patients (nine with -7/del7q and 11 with normal karyotype) with 23 CD34+ preparations from healthy bone marrow donors. SKI, a nuclear oncogene, was highly up regulated. In a second set of 183 AML patients analyzed with real-time PCR, the highest expression level of SKI in AML with -7/del7q could be confirmed. As previously described, Ski associates with the retinoic acid receptor (RAR) complex and can repress transcription. We wanted to investigate the interference of Ski with RARalpha signaling in AML. Ski was co-immunoprecipitated and colocalized with RARalpha. We also found that overexpression of wild-type Ski inhibited the prodifferentiating effects of retinoic acid in U937 leukemia cells. Mutant Ski, lacking the N-CoR binding, was no more capable of repressing RARalpha signaling. The inhibition by wild-type Ski could partially be reverted by the histone deacetylase blocking agent valproic acid. In conclusion, Ski seems to be involved in the blocking of differentiation in AML via inhibition of RARalpha signaling.

Growth of human stem cell-derived neurons on solid three-dimensional polymers.

Understanding neural differentiation and the development of complex neurite networks in three-dimensional matrices is critical for neural tissue engineering in vitro. In this study we describe for the first time the growth of human stem cell-derived neurons on solid polystyrene matrices coated with bioactive molecules. Highly porous foams were prepared from poly(styrene/divinylbenzene) using a high internal phase emulsion (HIPE) as a template to create the porous structure. The resulting polyHIPE matrices were readily coated with aqueous-based solutions including poly-d-lysine and laminin. Human neurons adhered well to poly-d-lysine coated surfaces and extended neural processes, however, neurite outgrowth was particularly enhanced when polymers also received a coating of laminin. These data clearly demonstrate the potential use of solid polystyrene scaffolds to create three-dimensional environments for cell growth and differentiation. We propose that these robust and stable matrices can be conveniently and routinely used in the tissue culture laboratory to study the behaviour of cells grown in three-dimensions.

Methylcrotonyl-CoA carboxylase (MCC) deficiency associated with severe muscle pain and physical disability in an adult.

We present a patient with methylcrotonyl-CoA carboxylase (MCC) deficiency (McKusick 210200) who suffered from severe muscle pain and physical disability, and propose that this disorder be considered in the differential diagnosis of adult patients presenting with muscle pain and weakness.

Human embryonal carcinoma stem cells: models of embryonic development in humans.

There are few reliable experimental systems available to study the molecular mechanisms that govern human embryonic development. Embryonal carcinoma (EC) cells are pluripotent stem cells derived from teratocarcinomas and are considered the malignant counterparts of human embryonic stem (ES) cells. Several of the existing human EC stem cell lines provide robust and simple culture systems to study certain aspects of cellular differentiation in a manner pertinent to human embryogenesis. Here we review the strategies used to derive and characterize the established and recognized human EC stem cell line TERA2.cl.SP12. Furthermore, we demonstrate the value of human EC stem cells as a model of early development and focus on cell fate determination in the embryonic ectoderm.

Proteomic identification of biomarkers expressed by human pluripotent stem cells.

The ability to effectively monitor the behaviour of pluripotent stem cells and their differentiation is key to their use in basic and clinical research. Molecules expressed in particular cell types can be used to report the status of cell differentiation and is a recognised means of assessing the behaviour of cell cultures. There are currently few useful markers of stem cells and there is no rapid way to accurately determine their level of expression. In this study, we describe for the first time the potential of surface enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS) to identify novel biomarkers of human pluripotent embryonal carcinoma stem cells and their differentiated derivatives. This approach allows the rapid and sensitive screening of cell samples without the need to purify the specimen prior to analysis. The identification of proteins expressed in specific cell populations will provide valuable tools for monitoring cellular development.

Enhanced neurite outgrowth by human neurons grown on solid three-dimensional scaffolds.

Growing and differentiating human stem cells in vitro can provide access to study the molecular mechanisms that control cellular development in a manner pertinent to human embryogenesis. To fully understand such processes, however, it is important to recreate culture conditions that most closely relate to those in living tissues. As step in this direction, we have developed a robust three-dimensional cell culture system using inert highly porous solid matrices manufactured from polystyrene that can be routinely used to study the differentiation of human pluripotent stem cell-derived neurons in vitro. Neurite outgrowth was significantly enhanced when neurons were grown in a three-dimensional environment compared to traditional flat surfaces and resulted in the formation of extensive neural networks. These data suggest that the topography within the culture environment can significantly alter cell development and will therefore be an important feature when investigating the potential of human stem cells.

Oculomotor function in the rhesus monkey after deafferentation of the extraocular muscles.

The function of extraocular muscle proprioception in the control of eye movements remains uncertain. In this study, we examined the effect of bilateral proprioceptive deafferentation of the extraocular muscles on eye movements in two rhesus monkeys. Before and after deafferentation, we analyzed baseline ocular alignment, saccades, pursuit, and vestibular eye movements. We also examined visually mediated adaptation of ocular alignment, saccades, and pursuit. Deafferentation of the eye muscles did not affect baseline ocular motor control, either acutely or over a 5-week period of study. Furthermore, visually mediated adaptation of the eye movement subtypes was also unaffected by deafferentation. These results suggest that ocular proprioception in primates is not used in the immediate, on-line control of eye movements and does not interact with visual cues in the adaptive modification of ocular motor function. We conclude that the efferent command (efference copy) provides sufficient information about eye kinematics to the brain for accurate eye movement control in normal monkeys, and that this information is modified by visual feedback independently of proprioception. We hypothesize that proprioception may be used to calibrate the efference copy during development and in response to perturbations by signaling potential mismatches between eye movement information derived from the efferent command and the actual motion of the eye transduced by the proprioceptive organs.

Postvaricella angiopathy: report of a case with pathologic correlation.

Varicella is a common childhood illness, and central nervous system complications occur frequently. Delayed angiopathy has been described, although there are few reports of clinicopathologic correlation. A previously well 4-year-old male is presented. He suffered varicella 2 months before presentation with extensive right middle cerebral artery (MCA) territory infarction. Cerebral angiography demonstrated an isolated 89% stenosis of the right proximal MCA. He developed cerebral edema refractory to medical treatment and progressed to transtentorial herniation. Right frontal temporoparietal craniotomies were performed with evacuation of infarcted brain tissue. Pathologic studies revealed small vessel vasculitis with lymphocytic infiltration of the vessel wall. Areas of demyelination were present within the white matter. Polymerase chain reaction for varicella was negative on brain tissue. Postvaricella angiopathy, although an uncommon complication, may affect both small and large blood vessels, with catastrophic results.

Ski interacts with the evolutionarily conserved SNW domain of Skip.

Ski interacting protein (Skip) has been found to bind to the highly conserved region of Ski, which is required for its transforming activity. Ski is a unique oncoprotein that is involved in inducing both transformation and differentiation. At the molecular level, Ski has been shown to exhibit either co-activator or co-repressor activity depending on the cellular and promoter context. We were interested in further elucidating the biological implications of the Ski-Skip interaction. Here we have identified the SNW domain of Skip as the interaction region for Ski. This domain of Skip is highly conserved in all the Skip homologues identified from different species. Using a series of reporter plasmids, we show that Skip is a potent transcriptional activator of many different promoters, the activity of which was also mapped to the conserved core SNW domain of the protein. Addition of excess Ski further augmented the transcriptional activities of Skip, suggesting that one of the ways in which Ski brings about transformation is by binding and cooperating with the SNW domain of Skip in transcriptional activation.