Early effects of lipopolysaccharide-induced inflammation on foetal brain development in rat

Studies in humans and animal models link maternal infection and imbalanced levels of inflammatory mediators in the foetal brain to the aetiology of neuropsychiatric disorders. In a number of animal models, it was shown that exposure to viral or bacterial agents during a period that corresponds to the second trimester in human gestation triggers brain and behavioural abnormalities in the offspring. However, little is known about the early cellular and molecular events elicited by inflammation in the foetal brain shortly after maternal infection has occurred. In this study, maternal infection was mimicked by two consecutive intraperitoneal injections of 200 μg of LPS (lipopolysaccharide)/kg to timed-pregnant rats at GD15 (gestational day 15) and GD16. Increased thickness of the CP (cortical plate) and hippocampus together with abnormal distribution of immature neuronal markers and decreased expression of markers for neural progenitors were observed in the LPS-exposed foetal forebrains at GD18. Such effects were accompanied by decreased levels of reelin and the radial glial marker GLAST (glial glutamate transporter), and elevated levels of pro-inflammatory cytokines in maternal serum and foetal forebrains. Foetal inflammation elicited by maternal injections of LPS has discrete detrimental effects on brain development. The early biochemical and morphological changes described in this work begin to explain the sequelae of early events that underlie the neurobehavioural deficits reported in humans and animals exposed to prenatal insults

Laboratory misdiagnosis of von Willebrand disease in post- menarchal females: A multi- center study

Increased awareness of von Willebrand Disease (VWD) has led to more frequent diagnostic laboratory testing, which insurers often dictate be performed at a facility with off- site laboratory processing, instead of a coagulation facility with onsite processing. Off- site processing is more prone to preanalytical variables causing falsely low levels of von Willebrand Factor (VWF) due to the additional transport required. Our aim was to determine the percentage of discordance between off- site and onsite specimen processing for VWD in this multicenter, retrospective study. We enrolled females aged 12 to 50- years who had off- site specimen processing for VWF assays, and repeat testing performed at a consulting institution with onsite coagulation phlebotomy and processing. A total of 263 females from 17 institutions were included in the analysis. There were 251 subjects with both off- site and onsite VWF antigen (VWF:Ag) processing with 96 (38%) being low off- site and 56 (22%) low onsite; 223 subjects had VWF ristocetin co- factor (VWF:RCo), 122 (55%) were low off- site and 71 (32%) were low onsite. Similarly, 229 subjects had a Factor VIII (FVIII) assay, and 67 (29%) were low off- site with less than half, 29 (13%) confirmed low with onsite processing. Higher proportions of patients demonstrated low VWF:Ag, VWF:RCo, and/or FVIII with off- site processing compared to onsite (McNemarʼs test P- value <.0005, for all assays). These results emphasize the need to decrease delays from sample procurement to processing for VWF assays. The VWF assays should ideally be collected and processed at the same site under the guidance of a hematologist.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156476/2/ajh25869.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156476/1/ajh25869_am.pd

Is ≥ 100% the magic number to rule out the laboratory diagnosis of von Willebrand disease based on initial testing?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/170804/1/ajh26343_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170804/2/ajh26343.pd

Contribution of neuroblastoma-derived exosomes to the production of pro-tumorigenic signals by bone marrow mesenchymal stromal cells

International audienceThe bone marrow (BM) niche is a microenvironment promoting survival, dormancy and therapeutic resistance in tumor cells. Central to this function are mesenchymal stromal cells (MSCs). Here, using neuroblastoma (NB) as a model, we demonstrate that NB cells release an extracellular vesicle (EVs) whose protein cargo is enriched in exosomal proteins but lacks cytokines and chemokines. Using three different purification methods, we then demonstrate that NB-derived exosomes were captured by MSCs and induced the production of pro-tumorigenic cytokines and chemokines, including interleukin-6 (IL-6), IL-8/CXCL8, vascular endothelial cell growth factor and monocyte-chemotactic protein-1, with exosomes prepared by size exclusion chromatography having the highest activity. We found no correlation between the IL-6 and IL-8/CXCL8 stimulatory activity of exosomes from eight NB cell lines and their origin, degree of MYCN amplification, drug resistance and disease status. We then demonstrate that the uptake of NB exosomes by MSCs was associated with a rapid increase in ERK1/2 and AKT activation, and that blocking ERK1/2 but not AKT activation inhibited the IL-6 and IL-8/CXCL8 production by MSCs without affecting exosome uptake. Thus, we describe a new mechanism by which NB cells induce in MSCs an inflammatory reaction that contributes to a favorable microenvir-onment in the BM

Survival outcomes and surgical morbidity based on surgical approach to pulmonary metastasectomy in pediatric, adolescent and young adult patients with osteosarcoma

Abstract Background Thoracotomy is considered the standard surgical approach for the management of pulmonary metastases in osteosarcoma (OST). Several studies have identified the advantages of a thoracoscopic approach, however, the clinical significance of thoracotomy compared to thoracoscopy is yet to be evaluated in a randomized trial. Aims The primary aim was to determine the survival outcomes in OST patients based on surgical approach for pulmonary metastasectomy (PM) and secondary aim was to assess the post‐operative morbidities of OST PM through various surgical approaches. Materials and Methods We conducted a single institution retrospective study to compare survival outcomes and surgical morbidity according to the surgical approach of the management of pulmonary metastases in patients with OST. Results Sixty‐one patients with OST underwent PM. Twenty‐one patients were metastatic at diagnosis and underwent PM during primary treatment; nine had thoracotomy, six thoracoscopy, and six combined thoracoscopy with thoracotomy (CTT). Forty‐three patients with first pulmonary relapse or progression underwent PM; 18 had thoracotomy, 16 thoracoscopy and nine CTT. There was no difference in survival between surgical approaches. There were significantly more postoperative morbidities associated with thoracotomy for initial PM (pain and postoperative chest tube placement), and for PM at first relapse (pneumothoraces, pain, Foley catheter use and prolonged hospitalizations). Conclusion Our study demonstrates that patients with OST pulmonary metastases have comparable poor outcomes despite varying surgical approaches for PM. There were significantly more postoperative morbidities associated with thoracotomy for PM. Surgical bias and other competing risks could not be assessed given the limitations of a retrospective study and may be addressed in a prospective trial evaluating surgical approach for PM in OST

Early effects of lipopolysaccharide-induced inflammation on foetal brain development in rat.

Studies in humans and animal models link maternal infection and imbalanced levels of inflammatory mediators in the foetal brain to the aetiology of neuropsychiatric disorders. In a number of animal models, it was shown that exposure to viral or bacterial agents during a period that corresponds to the second trimester in human gestation triggers brain and behavioural abnormalities in the offspring. However, little is known about the early cellular and molecular events elicited by inflammation in the foetal brain shortly after maternal infection has occurred. In this study, maternal infection was mimicked by two consecutive intraperitoneal injections of 200 μg of LPS (lipopolysaccharide)/kg to timed-pregnant rats at GD15 (gestational day 15) and GD16. Increased thickness of the CP (cortical plate) and hippocampus together with abnormal distribution of immature neuronal markers and decreased expression of markers for neural progenitors were observed in the LPS-exposed foetal forebrains at GD18. Such effects were accompanied by decreased levels of reelin and the radial glial marker GLAST (glial glutamate transporter), and elevated levels of pro-inflammatory cytokines in maternal serum and foetal forebrains. Foetal inflammation elicited by maternal injections of LPS has discrete detrimental effects on brain development. The early biochemical and morphological changes described in this work begin to explain the sequelae of early events that underlie the neurobehavioural deficits reported in humans and animals exposed to prenatal insults