Endothelial-like malignant glioma cells in dynamic three dimensional culture identifies a role for VEGF and FGFR in a tumor-derived angiogenic response

Aims: Recent studies have observed that cells from high-grade glial tumors are capable of assuming an endothelial phenotype and genotype, a process termed ‘vasculogenic mimicry’ (VM). Here we model and manipulate VM in dynamic 3-dimensional (3D) glioma cultures. Methods: The Rotary Cell Culture System (RCCS) was used to derive large macroscopic glioma aggregates, which were sectioned for immunohistochemistry and RNA extracted prior to angiogenic array-PCR. Results: A 3D cell culture induced microenvironment (containing only glial cells) is sufficient to promote expression of the endothelial markers CD105, CD31 and vWF in a proportion of glioma aggregates in vitro. Many pro-angiogenic genes were upregulated in glioma aggregates and in primary explants and glioma cells were capable of forming tubular-like 3D structures under endothelial-promoting conditions. Competitive inhibition of either vascular endothelial growth factor or fibroblast growth factor receptor was sufficient to impair VM and downregulate the tumor-derived angiogenic response, whilst impairing tumor cell derived tubule formation. Glioma xenografts using the same cells reveal tumor-derived vessel-like structures near necrotic areas, consistent with widespread tumor-derived endothelial expression in primary glioma tissue. Conclusions: Our findings support studies indicating that tumor-derived endothelial cells arise in gliomas and describe a dynamic 3D culture as a bona fide model to interrogate the molecular basis of this phenomenon in vitro. Resistance to current anti-angiogenic therapies and the contribution of tumor derived endothelial cells to such resistance are amenable to study using the RCCS.     

Isolates with low-level vancomycin resistance associated with persistent methicillin-resistant Staphylococcus aureus bacteremia

Low-level vancomycin-resistant Staphylococcus aureus (vancomycin-intermediate S. aureus [VISA] and heterogenous VISA [hVISA]) is increasingly reported and leads to glycopeptide treatment failure. Various phenotypic features have been reported for these isolates, but the genetic changes leading to hVISA and VISA have yet to be clearly determined. We assessed phenotypic, antibiotic resistance, and genomic changes by using genomic DNA microarray comparison and sequencing of selected loci in five pairs of clinical hVISA/VISA strains and the initial methicillin-resistant Staphylococcus aureus (MRSA) isolates obtained prior to vancomycin therapy. The isolates were from adult patients in Australia and New Zealand who had persistent MRSA bacteremia (>7 days) while receiving vancomycin therapy. In all cases, the initial isolates were found to be fully vancomycin-susceptible Staphylococcus aureus (VSSA). The hVISA/VISA phenotype was associated with increased cell wall thickness, reduced autolytic activity in four of five hVISA/VISA strains, and a striking reduction in biofilm formation compared to the parent strains in all pairs. All five pairs appeared to be isogenic, and genomic DNA microarray comparison suggested that major genetic changes are not required for the development of the resistant phenotype in these strains. No sequence differences were found in the agr locus or the tcaRA genes for any pair, but a marked reduction in RNAIII expression was found in four pairs. In summary, hVISA/VISA arises from fully VSSA during persistent infection that fails to respond to glycopeptide therapy and is associated with significant phenotypic changes, including a marked reduction in biofilm-forming ability. These clinically derived pairs of isolates will be a useful resource to elucidate the genetic mechanism of resistance in hVISA/VISA strains.     

Case reports: headache caused by a spinal cord stimulator in the upper cervical spine

We report persistent headaches developing in a patient subsequent to the placement of a spinal cord stimulator in the upper cervical spine. These persistent headaches responded to dihydroergotamine and sumatriptan. Headaches ceased upon repositioning of the stimulator lower in the cervical spine. We postulate an effect of the device on the trigeminovascular system via the nucleus caudalis trigeminalis and/or spinal trigeminal tract.     

Adapting a blended motivational interviewing and problem-solving intervention to address risky substance use amongst South Africans

Abstract

The purpose of this study was to examine the acceptability and initial substance use outcomes of a blended motivational interviewing (MI) and problem-solving therapy (PST) intervention, delivered by peer counsellors. Twenty people who scored at risk for substance use according to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) received a five session blended MI-PST intervention and were assessed at baseline and at three months. An open-ended semi-structured interview, designed to identify possible factors that may hinder or promote the acceptability of the intervention was also conducted. Fifteen participants completed the intervention and the three-month follow-up. According to ASSIST scores, participants significantly reduced their substance use (p > 0.001) at the three-month follow-up. Randomized controlled trials are needed to evaluate the effect of this intervention more rigorously.     

Recurrent episodes of rhabdomyolysis in pontocerebellar hypoplasia type 2

Pontocerebellar hypoplasia type 2 is an autosomal recessive disorder characterized by hypoplasia and atrophy of the cerebellum and pons, leading to microcephaly, dystonia/dyskinesia, seizures, and severe cognitive impairment. Until lately it was considered a CNS-refined disease, but recent reports have associated it with muscular defects, as well. A 5-year-old boy with genetically confirmed pontocerebellar hypoplasia type 2 is described. The patient had all the clinical and radiological features of the disease, but he, additionally, exhibited two episodes of rhabdomyolysis precipitated by respiratory infections. The possible mechanisms associating encephalopathy and myopathy in pontocerebellar hypoplasia type 2 are discussed.     

Brief Report: Do Service Dog Providers Placing Dogs with Children with Developmental Disabilities Use Outcome Measures and, If So, What Are they?

The aim of this study was to identify the outcomes expected and assessed by those providing service dogs to children with developmental disabilities. Seventeen registered service dog providers were invited to complete a mixed methods online survey. Five providers, who prepared dogs to work with a wide range of conditions and behaviours, mainly Asperger’s syndrome, autism and communication disorders, completed the survey. All five participants reported that they expected to see positive changes as a consequence of the service dog placement, in both the recipient child and their family, including improvements in attention span and language skills, as well as increased familial cohesion. Survey responses indicated that not all desired outcomes were routinely assessed. The range of assessments used were interviews, intake conversations, pre-placement questionnaires, child social dairies filled in by parents, follow up surveys after placement, and child observation by parents. No specifically named valid and reliable clinical or research measures were referred to, showing an emphasis on assessments from parents and service dog providers. It is not clear whether pre-intervention assessments are repeated systematically at follow-up, which could show robust intervention effects. There is scope for professionals in developmental disability to work with service dog providers to improve the evidence base in this field.     

Hybrid Ti6Al4V/Silk Fibroin Composite for Load-Bearing Implants: A Hierarchical Multifunctional Cellular Scaffold

Despite the tremendous technological advances that metal additive manufacturing (AM) has made in the last decades, there are still some major concerns guaranteeing its massive industrial application in the biomedical field. Indeed, some main limitations arise in dealing with their biological properties, specifically in terms of osseointegration. Morphological accuracy of sub-unital elements along with the printing resolution are major constraints in the design workspace of a lattice, hindering the possibility of manufacturing structures optimized for proper osteointegration. To overcome these issues, the authors developed a new hybrid multifunctional composite scaffold consisting of an AM Ti6Al4V lattice structure and a silk fibroin/gelatin foam. The composite was realized by combining laser powder bed fusion (L-PBF) of simple cubic lattice structures with foaming techniques. A combined process of foaming and electrodeposition has been also evaluated. The multifunctional scaffolds were characterized to evaluate their pore size, morphology, and distribution as well as their adhesion and behavior at the metal–polymer interface. Pull-out tests in dry and hydrated conditions were employed for the mechanical characterization. Additionally, a cytotoxicity assessment was performed to preliminarily evaluate their potential application in the biomedical field as load-bearing next-generation medical devices.     

Development and Validation of a Bioinformatic Workflow for the Rapid Detection of Viruses in Biosecurity

The field of biosecurity has greatly benefited from the widespread adoption of high-throughput sequencing technologies, for its ability to deeply query plant and animal samples for pathogens for which no tests exist. However, the bioinformatics analysis tools designed for rapid analysis of these sequencing datasets are not developed with this application in mind, limiting the ability of diagnosticians to standardise their workflows using published tool kits. We sought to assess previously published bioinformatic tools for their ability to identify plant- and animal-infecting viruses while distinguishing from the host genetic material. We discovered that many of the current generation of virus-detection pipelines are not adequate for this task, being outperformed by more generic classification tools. We created synthetic MinION and HiSeq libraries simulating plant and animal infections of economically important viruses and assessed a series of tools for their suitability for rapid and accurate detection of infection, and further tested the top performing tools against the VIROMOCK Challenge dataset to ensure that our findings were reproducible when compared with international standards. Our work demonstrated that several methods provide sensitive and specific detection of agriculturally important viruses in a timely manner and provides a key piece of ground truthing for method development in this space.