Novel method to biopsy aneurysmal bone cysts in children

PURPOSE

The thin and friable septations composing aneurysmal bone cysts (ABC) may be challenging to target for percutaneous biopsy. The purpose of this study was to describe and evaluate a novel method of ABC biopsy using endomyocardial biopsy forceps as an attempt to capture larger fragments of tissue for diagnosis.

METHODS AND MATERIALS

This was a retrospective study performed over a 17-year period. Patients <18 years old who underwent percutaneous biopsy for a presumed ABC, based on pre-procedure imaging, were included. Medical records were reviewed to identify age, sex, lesion location, biopsy procedure details, complications, and pathology results. A diagnostic biopsy was defined as conclusive histologic confirmation. Inconclusive findings or findings suggestive of but not diagnostic of an ABC were treated as non-diagnostic, even if imaging and clinical findings were characteristic. Biopsy device selection and quantity of tissue obtained was at the discretion of the pediatric interventional radiologist. Fisher's exact test was used to compare the diagnostic yield of standard biopsies to those employing biopsy forceps.

RESULTS

Twenty-three biopsies were performed in 18 patients (11 female) with a median age of 14.7 years (IQR 10.6-15.6). Lesions were located in the extremities (7, 30.4%), chest (6, 26.1%), pelvis (5, 21.7%), spine (4, 17.4%), and mandible (1, 4.3%). Specimens were obtained using a 13- or 15-gauge bone coring needle (11, 47.8%); 14-, 16-, or 18-gauge soft tissue needle (6, 26.1%); or a combination of bone and soft tissue (4, 17.4%) needles. Endomyocardial biopsy forceps were utilized in 7 cases (30.4%), 2 in which it was the only device used. Overall, a conclusive pathologic diagnosis was made in 13/23 (56.5%) biopsies. Of the diagnostic biopsies, 1 was a unicameral bone cyst and all others were ABCs. No malignancy was identified. Compared to the standard approach, the use of forceps was more likely to result in a diagnostic biopsy (40.0% vs 100.0%, p = 0.008). There were no complications.

CONCLUSIONS

Endomyocardial biopsy forceps offer an additional, novel technique to biopsy presumed ABCs and may improve diagnostic yield.

Liver Biopsy Leads to Serendipitous Diagnosis of Glycogen Storage Disease Type IX in a Patient With Fontan-Associated Liver Disease

Fontan-associated liver disease (FALD) is a form of congestive hepatopathy resulting from Fontan palliation procedures in patients with single ventricle physiology. Although there is variation between pediatric centers, the surveillance for FALD may include liver biopsies for assessment of degree of fibrosis. Our report describes a 7-year-old girl with hypoplastic left heart syndrome who underwent Fontan palliation at age 2, and presented with disproportionate hepatomegaly, elevated liver enzymes, and increased stiffness on liver elastography. Liver biopsy showed diffuse hepatocellular cytoplasmic glycogenation, leading to the diagnosis of glycogen storage disease IX. This case demonstrates the importance of investigating unexpected physical exam findings and the potential for serendipitous benefit of liver biopsy in FALD.

Expanding the reproductive organ phenotype of CHD7-spectrum disorder

CHD7 disorder is a multiple congenital anomaly syndrome with a highly variable phenotypic spectrum, and includes CHARGE syndrome. Internal and external genital phenotypes frequently seen in CHD7 disorder include cryptorchidism and micropenis in males, and vaginal hypoplasia in females, both thought to be secondary to hypogonadotropic hypogonadism. Here, we report 14 deeply phenotyped individuals with known CHD7 variants (9 pathogenic/likely pathogenic and 5 VOUS) and a range of reproductive and endocrine phenotypes. Reproductive organ anomalies were observed in 8 of 14 individuals and were more commonly noted in males (7/7), most of whom presented with micropenis and/or cryptorchidism. Kallmann syndrome was commonly observed among adolescents and adults with CHD7 variants. Remarkably, one 46,XY individual presented with ambiguous genitalia, cryptorchidism with Müllerian structures including uterus, vagina and fallopian tubes, and one 46,XX female patient presented with absent vagina, uterus and ovaries. These cases expand the genital and reproductive phenotype of CHD7 disorder to include two individuals with genital/gonadal atypia (ambiguous genitalia), and one with Müllerian aplasia.

Bizarre Chorionic-type Trophoblast in Second-trimester and Third-trimester Placentas: Clinicopathologic Characterization of a Placental Pseudoneoplastic Lesion

Bizarre (atypical/symplastic) cells have been described in various gynecologic normal tissues and benign neoplasms. This type of bizarre cytologic change is usually an incidental finding and is regarded as a benign process. We describe 17 cases of bizarre chorionic-type trophoblast in second-trimester and third-trimester placentas that created concern for an underlying/undersampled or incipient intraplacental trophoblastic neoplasm, predominantly found in intervillous trophoblastic islands (11/17), placental septae (6/17), chorionic plate (1/17), and/or the chorion layer of fetal membranes (2/17). The bizarre trophoblastic cells exhibited sheet-like or nested architecture, had a multifocal/patchy distribution, and/or were present as individual cells within hyaline stroma; they were characterized by large nuclei with smudgy chromatin and occasional intranuclear pseudoinclusions. The degree of atypia was classified as mild (0/17), moderate (3/17), or severe (14/17). Mitotic figures and necrosis were not identified. A dual immunohistochemical stain for trophoblast (hydroxyl-delta-5-steroid dehydrogenase) and a proliferation marker (Ki-67), performed in 15 cases, demonstrated 0% to very low proliferative activity within the bizarre trophoblast (0% to 2% [10/15], 3% to 8% [5/15]). Immunohistochemical stains for fumarate hydratase showed intact/retained expression in the bizarre cells in 7 of 7 cases. Clinical follow-up ranged from 1 to 45 months, and all patients were alive and well without subsequent evidence of a gestational trophoblastic or other neoplasms. We conclude that bizarre chorionic-type trophoblast in second-trimester or third-trimester placentas have the potential to mimic an intraplacental trophoblastic neoplasm but are likely a benign degenerative change. This study expands the spectrum of bizarre cells that occur in the gynecologic tract.

The electrospinning of a thermo-responsive polymer with peptide conjugates for phenotype support and extracellular matrix production of therapeutically relevant mammalian cells

Current cell expansion methods for tissue engineering and regenerative medicine applications rely on the use of enzymatic digestion passaging and 2D platforms. However, this enzymatic treatment significantly reduces cell quality, due to the destruction of important cell-surface proteins. In addition, culture in 2D results in undesired de-differentiation of the cells caused by the lack of 3D similarity to the natural extracellular matrix (ECM) environment. Research has led to the development of thermo-responsive surfaces for the continuous culture of cells. These thermo-responsive materials properties can be used to passage cells from the surface when the cell culture temperature is reduced. Here we report the development of a PLA/thermo-responsive (PDEGMA) blend 3D electrospun fibre-based scaffold to create an enzymatic-free 3D cell culture platform for the expansion of mammalian cells with the desired phenotype for clinical use. Human corneal stromal cells (hCSCs) were used as an exemplar as they have been observed to de-differentiate to an undesirable myo-fibroblastic phenotype when cultured by conventional 2D cell culture methods. Scaffolds were functionalised with a cell adherence peptide sequence GGG-YIGSR by thiol-ene chemistry to improve cell adherence and phenotype support. This was obtained by functionalising the thermo-responsive polymer with a thiol (PDEGMA/PDEGSH) by co-polymerisation. These incorporated thiols react with the norbornene acid functionalised peptide (Nor-GGG-YIGSR) under UV exposure. Presence of the thiol in the scaffold and subsequent peptide attachment on the scaffolds were confirmed by fluorescence labelling, ToF-SIMS and XPS analysis. The biocompatibility of the peptide containing scaffolds was assessed by the adhesion, proliferation and immuno-staining of hCSCs. Significant increase in hCSC adherence and proliferation was observed on the peptide containing scaffolds. Immuno-staining showed maintained expression of the desired phenotypic markers ALDH, CD34 and CD105, while showing no or low expression of the undesired phenotype marker α-SMA. This desired expression was observed to be maintained after thermo-responsive passaging and higher when cells were cultured on PLA scaffolds with 10 wt% PDEGMA/4 mol% PDEGS-Nor-GGG-YIGSR. This paper describes the fabrication and application of a first generation, biocompatible peptide conjugated thermo-responsive fibrous scaffold. The ease of fabrication, successful adherence and expansion of a therapeutically relevant cell type makes these scaffolds a promising new class of materials for the application of cell culture expansion platforms in the biomaterials and tissue engineering field.

C-10 Interaction of ApoE4 and Gender in Neuropsychiatric Presentation in Probable Alzheimer’s Disease

Objective

Individuals with probable Alzheimer’s disease (pAD) often have neuropsychiatric symptoms; however, the relationship of these symptoms and ApoE4 status is unclear. Recent research suggests gender moderates the relationship of ApoE4 to AD. We examined how ApoE4 genetic status and gender predict neuropsychiatric symptoms in older adults with pAD.

Method

Data from the National Alzheimer’s Coordinating Centers (NACC) was utilized in the present study. We included only individuals diagnosed with pAD with collaterals who were judged reliable by clinical NACC staff and who saw the participant at least three times per week. The selected sample (N = 6943) was 52% male; 85.6% White, 10.2% African American; and 7.5% Hispanic. Average age was 73 years. The Neuropsychiatric Inventory-Questionnaire, completed by the participant’s collateral, was used to assess symptoms. Analyses controlled for age and cognitive impairment as measured by the Mini-Mental State Examination.

Results

The presence of at least one ApoE4 allele predicted higher severity of delusions, p = .04. Males had higher severity of agitation, apathy, and irritability; females had higher delusions, depression, and anxiety, all p’s < .05. Gender moderated the relationship of ApoE4 with disinhibition, night disturbances, and appetite, all p’s < .05. In all three cases, for males, scores were higher for non-carriers than for ApoE4 carriers; however, for females, differences did not exist between carriers and non-carriers.

Conclusions

Differences between ApoE4 carriers and non-carriers as well as between genders are demonstrated, and evidence supports the hypothesis that gender and ApoE4 status interact to predict some pAD neuropsychiatric symptomatology.

HPV-ISH-Negative Invasive Cervical Squamous Cell Carcinoma: Histologic and Pap Test Results

INTRODUCTION

A causal link between infection with a high-risk strain of human papilloma virus (hrHPV) and the development of cervical squamous cell carcinoma (SCC) is well established. However, a small number of SCCs are hrHPV-negative by either HPV co-DNA testing and/or HPV-in situ hybridization (HPV-ISH) at the time of diagnosis. These apparently hrHPV-negative lesions are poorly understood, specifically whether hrHPV-positive precursor lesions exist, which would be detected through hrHPV-based screening.

METHODS

A search of the pathology archives at the Johns Hopkins Hospital identified women with a diagnosis of hrHPV-negative cervical SCC on surgical specimen. All prior pathologies, including cervical cytology and surgical pathology specimens, and associated hrHPV DNA test results, p16 immunohistochemistry, and HPV-ISH were reviewed.

RESULTS

A total of 25 women were identified having a surgical specimen diagnosed as SCC with either negative or equivocal HPV-ISH. Fifteen had a Pap test in the 6 months preceding a diagnosis of SCC, with cytology diagnoses as follows: high-grade squamous intraepithelial lesion n = 14/15; atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion n = 1/15. hrHPV co-testing was performed for 5 of these 15 women and was negative in 2/5 cases. Cervical biopsy was performed for 24 women. HPV-ISH testing, performed on 14 of the biopsy specimens, was negative for 11/14 patients. Of 15 specimens stained for p16, 14 were positive.

CONCLUSION

A subset of patients exist in whom hrHPV is not detectable at or near the time of progression to SCC. Additional research is necessary to further describe this population and determine whether maintaining cytological screening would provide benefit.

Validity and reliability of a freehand 3D ultrasound system for the determination of triceps surae muscle volume in children with cerebral palsy

This study assessed the validity, intra-rater and inter-rater reliability of segmentation of in vivo medial gastrocnemius (MG), lateral gastrocnemius (LG) and soleus (SOL) muscle volume measurement using a single sweep freehand 3D ultrasound (3DUS) in children with cerebral palsy (CP). The MG, LG and SOL of both limbs of 18 children with CP (age 8 years 4 months ± 1 year 10 months, 11 males, unilateral CP = 9, bilateral CP = 9, Gross Motor Functional Classification System I = 11, II = 7) were scanned using freehand 3DUS and magnetic resonance imaging (MRI). All freehand 3DUS and MRI images were segmented and volumes rendered by two raters. Validity was assessed using limits of agreement method. Intra-rater and inter-rater reliability was assessed using intra-class correlation (ICC), coefficient of variance (CV) and minimal detectable change (MDC). Freehand 3DUS overestimated muscle volume of the MG and LG by < 0.3 mL (1%) and underestimated SOL by < 1.3 mL (1.5%) compared with MRI. ICCs for intra-rater reliability of the segmentation process for the freehand 3DUS system and MRI for muscle volume were > 0.98 and 0.99, respectively, for all muscles. ICCs for inter-rater reliability of the segmentation process for freehand 3DUS and MRI volumes were > 0.96 and 0.98, respectively, for all muscles. MDCs for single rater freehand 3DUS and MRI were < 4.0 mL (14%) and 3.2 mL (11%), respectively, in all muscles. Freehand 3DUS is a valid and reliable method for the measurement of lower leg muscle volume that can be measured with a single sweep in children with CP in vivo. It can be used as an alternative to MRI for the detection of clinically relevant changes in calf muscle volume as the result of growth and interventions.

Regulation of fetal hemoglobin expression during hematopoietic stem cell development and its importance in bone metabolism and osteoporosis

We have shown that an altered tissue redox environment in mice lacking either murine beta Hemoglobin major (Hgbβ_maKO) or minor (Hgbβ_miKO) regulates inflammation. The REDOX environment in marrow stem cell niches also control differentiation pathways. We investigated osteoclastogenesis (OC)/osteoblastogenesis (OB), in bone cultures derived from untreated or FSLE-treated WT, Hgbβ_maKO or Hgbβ_miKO mice. Marrow mesenchymal cells from 10d pre-cultures were incubated on an osteogenic matrix for 21d prior to analysis of inflammatory cytokine release into culture supernatants, and relative OC:OB using (TRAP:BSP, RANKL:OPG) mRNA expression ratios and TRAP or Von Kossa staining. Cells from WT and Hgbβ_maKO mice show decreased IL-1β,TNFα and IL-6 production and enhanced osteoblastogenesis with altered mRNA expression ratios and increased bone nodules (Von Kossa staining) in vitro after in vivo stimulation of mRNA expression of fetal Hgb genes (Hgbε and Hgbβ_mi) by a fetal liver extract (FSLE). Marrow from Hgbβ_miKO showed enhanced cytokine release and preferential enhanced osteoclastogenesis relative to similar cells from WT or Hgbβ_maKO mice, with no increased osteoblastogenesis after mouse treatment with FSLE. Pre-treatment of WT or Hgbβ_maKO, but not Hgbβ_miKO mice, with other molecules (rapamycin; hydroxyurea) which increase expression of fetal Hgb genes also augmented osteoblastogenesis and decreased cytokine production in cells differentiating in vitro. Infusion of rabbit anti- Hgbε or anti- Hgbβ_mi, but not anti-Hgbα or anti- Hgbβ_ma into WT mice from day 13 gestation for 3 weeks led to attenuated osteoblastogenesis in cultured cells. We conclude that increased fetal hemoglobin expression, or use of agents which improve fetal hemoglobin expression, increases osteoblast bone differentiation in association with decreased inflammatory cytokine release.

Entzündungsnachweis und HAMA-Bildung nach Applikation des monoklonalen Antikörpers BW 250/183

Es wird über Erfahrungen mit dem 99mTc-markierten monoklonalen Antikörper BW 250/183 zum Entzündungsnachweis berichtet. Die Validisierung erfolgte an 160 von 354 untersuchten Patienten. Es ergab sich mit einer Sensitivität von 91 % und einer Spezifität von 82% eine hohe diagnostische Treffsicherheit. Ein in 72 Fällen durchgeführter Vergleich zwischen konventioneller 3-Phasen-Knochenszintigraphie und der Granulozytenszintigraphie ergab einen positiven immunszintigraphischen Entzündungsnachweis in 76% der positiven Knochenszintigramme. Bei 84 Erstuntersuchten und 6 Zweituntersuchten wurden die HAMA-Titer 1 bis 12 Monate nach Applikation untersucht. Es zeigte sich bei den Zweituntersuchten lediglich 1 Patient mit einem mäßig erhöhten HAMA-Titer. Hieraus wird der Schluß gezogen, daß der monoklonale Antikörper BW 250/183 sehr gut zum szintigraphischen Entzündungsnachweis geeignet ist.

A design of experiments approach to identify the influencing parameters that determine poly-D,L-lactic acid (PDLLA) electrospun scaffold morphologies

Electrospun fibrous materials have increasing applications in regenerative medicine due to the similarity of fibre constructs to the morphology of certain extracellular matrices. Although experimentally the electrospinning method is relatively simple, at the theoretical level the interactions between process parameters and their influence on the fibre morphology is not yet fully understood. Here, we hypothesised that a design of experiments (DoE) model could determine combinations of process parameters that result in significant effects on poly-D,L-lactic acid (PDLLA) fibre morphology. The process parameters used in this study were applied voltage, needle-to-collector distance, flow rate and polymer concentration. Data obtained for mean fibre diameter, standard deviation (SD) of the fibre diameter (measure of fibre morphology) and presence of 'beading' on the fibres (beads per μm²) were evaluated as a measure of PDLLA fibre morphology. Uniform fibres occurred at SDs of ≤500 nm, 'beads-on-string' morphologies were apparent between ±500 and 1300 nm and large beads were observed at ±1300-1800 nm respectively. Mean fibre diameter was significantly influenced by the applied voltage and interaction between flow rate and polymer concentration. Fibre morphology was mainly influenced by the polymer concentration, while bead distribution was significantly influenced by the polymer concentration as well as the flow rate. The resultant DoE model regression equations were tested and considered suitable for the prediction of parameters combinations needed for desired PDLLA fibre diameter and additionally provided information regarding the expected fibre morphology.

Control of targeting ligand display by pH-responsive polymers on gold nanoparticles mediates selective entry into cancer cells

Selective targeting of cells for intracellular delivery of therapeutics represents a major challenge for pharmaceutical intervention in disease. Here we show pH-triggered receptor-mediated endocytosis of nanoparticles via surface ligand exposure. Gold nanoparticles were decorated with two polymers: a 2 kDa PEG with a terminal folate targeting ligand, and a di-block copolymer including a pH-responsive and a hydrophilic block. At the normal serum pH of 7.4, the pH-responsive block (apparent pK_a of 7.1) displayed a hydrophilic extended conformation, shielding the PEG-folate ligands, which inhibited cellular uptake of the nanoparticles. Under pH conditions resembling those of the extracellular matrix around solid tumours (pH 6.5), protonation of the pH-responsive polymer triggered a coil-to-globule polymer chain contraction, exposing folate residues on the PEG chains. In line with this, endocytosis of folate-decorated polymer-coated gold nanoparticles in cancer cells overexpressing folate receptor was significantly increased at pH 6.5, compared with pH 7.4. Thus, the tumour acidic environment and high folate receptor expression were effectively exploited to activate cell binding and endocytosis of these nanoparticles. These data provide proof-of-concept for strategies enabling extracellular pH stimuli to selectively enhance cellular uptake of drug delivery vectors and their associated therapeutic cargo.

Neuronal Progenitor Cells of the Neonatal Subventricular Zone Differentiate and Disperse following Transplantation into the Adult Rat Striatum

We have investigated the suitability of a recently identified and characterized population of neuronal progenitor cells for their potential use in the replacement of degenerating or damaged neurons in the mammalian brain. The unique population of neuronal progenitor cells is situated in a well-delineated region of the anterior part of the neonatal subventricular zone (referred to as SVZa). This region can be separated from the remaining proliferative, gliogenic, subventricular zone encircling the lateral ventricles of the forebrain. Because the neurons arising from the highly enriched neurogenic progenitor cell population of the SVZa ordinarily migrate considerable distances and ultimately express the neurotransmitters GABA and dopamine, we have examined whether they could serve as an alternative source of tissue for neural transplantation. SVZa cells from postnatal day 0-2 rats, prelabeled by intraperitoneal injections of the cell proliferation marker BrdU, were implanted into the striatum of adult rats approximately 1 mo after unilateral denervation by 6-OHDA. To examine the spatio-temporal distribution and phenotype of the transplanted SVZa cells, the experimental recipients were perfused at short (less than 1 wk), intermediate (2-3 wk) and long (5 mo) postimplantation times. The host brains were sectioned and stained with an antibody to BrdU and one of several cell-type specific markers to determine the phenotypic characteristics of the transplanted SVZa cells. To identify neurons we used the neuron-specific antibody TuJ1, or antimembrane-associated protein 2 (MAP-2), and anti-GFAP was used to identify astrocytic glia. At all studied intervals the majority of the surviving SVZa cells exhibited a neuronal phenotype. Moreover, morphologically they could be distinguished from the cells of the host striatum because they resembled the intrinsic granule cells of the olfactory bulb, their usual fate. At longer times, a greater number of the transplanted SVZa cells had migrated from their site of implantation, often towards an outlying blood vessel, and the density of cells within the core of the transplant was reduced. Furthermore, there were rarely signs of transplant rejection or a glial scar surrounding the transplant. In the core of the transplant there were low numbers of GFAP-positive cells, indicating that the transplanted SVZa cells, predominantly TuJ1-positive/MAP2-positive, express a neuronal phenotype. Collectively, the propensity of the SVZa cells to express a neuronal phenotype and to survive and integrate in the striatal environment suggest that they may be useful in the reconstruction of the brain following CNS injury or disease.

Dually sensitive dextran-based micelles for methotrexate delivery

Temperature and pH-sensitive micelles prepared from dextran grafted with poly(N-isopropylacrylamide) (PNIPAAm)/polyethylene glycol methyl ether (PEGMA) with/without 2-aminoethylmethacrylate (2-AEM) were evaluated as methotrexate delivery systems.

Vector-field statistics for the analysis of time varying clinical gait data

BACKGROUND

In clinical settings, the time varying analysis of gait data relies heavily on the experience of the individual(s) assessing these biological signals. Though three dimensional kinematics are recognised as time varying waveforms (1D), exploratory statistical analysis of these data are commonly carried out with multiple discrete or 0D dependent variables. In the absence of an a priori 0D hypothesis, clinicians are at risk of making type I and II errors in their analyis of time varying gait signatures in the event statistics are used in concert with prefered subjective clinical assesment methods. The aim of this communication was to determine if vector field waveform statistics were capable of providing quantitative corroboration to practically significant differences in time varying gait signatures as determined by two clinically trained gait experts.

METHODS

The case study was a left hemiplegic Cerebral Palsy (GMFCS I) gait patient following a botulinum toxin (BoNT-A) injection to their left gastrocnemius muscle.

FINDINGS

When comparing subjective clinical gait assessments between two testers, they were in agreement with each other for 61% of the joint degrees of freedom and phases of motion analysed. For tester 1 and tester 2, they were in agreement with the vector-field analysis for 78% and 53% of the kinematic variables analysed. When the subjective analyses of tester 1 and tester 2 were pooled together and then compared to the vector-field analysis, they were in agreement for 83% of the time varying kinematic variables analysed.

INTERPRETATION

These outcomes demonstrate that in principle, vector-field statistics corroborates with what a team of clinical gait experts would classify as practically meaningful pre- versus post time varying kinematic differences. The potential for vector-field statistics to be used as a useful clinical tool for the objective analysis of time varying clinical gait data is established. Future research is recommended to assess the usefulness of vector-field analyses during the clinical decision making process.

From Dreamtime to Nightmare: The voices of 168 Aboriginal (ex-)prisoners in New South Wales

The data presented in this paper form part of an action-research project commissioned jointly by the New South Wales Department of Corrective Services and the Ministry of Aboriginal Affairs in 1985. The major aims of this research were to investigate the chief causes and the rate of Aboriginal recidivism as well as making recommendations as to what kind of post-release support schemes would prove efficient, effective and useful.

In the course of the research, the archival records of 154 Aboriginal prisoners released from New South Wales gaols during the first six months of 1983 were analysed. Furthermore, 30 New South Wales State Government Officers and Aboriginal service providers as well as 68 Aboriginal ex-inmates and 100 Aboriginal inmates were interviewed.

The information presented in this paper is based mainly on an analysis of some answers given to us by the 68 Aboriginal ex-inmates and 100 Aboriginal inmates. The 68 Aboriginal ex-inmates interviewed resided in Canberra, Grafton, Maitland, Queanbeyan and Sydney. The interviews with the 100 Aboriginal prisoners were held in the following prisons: Bathurst, Cessnock, Glen Innes, Goulburn, Grafton, Maitland, Mulawa, Long Bay and Oberon.

Motorcyclist's thumb: carpometacarpal injuries of the thumb sustained in motorcycle crashes

The purpose of this study was to investigate motorcycle crash thumb injury patterns. We hypothesized that ulnar collateral ligament injuries at the thumb metacarpophalangeal joint would be most common and there would be a side predilection due to the clutch and brake positions. Motorcyclist admissions following injury between 2002 and 2013 were reviewed, and phalangeal and metacarpal injuries treated acutely identified. Demographics, injury, and treatment characteristics were recorded. Association between laterality and injury type was assessed. Of 128 patients, 59 underwent acute treatment for thumb injuries. Eleven patients sustained thumb ulnar collateral ligament injuries; 27 sustained thumb carpometacarpal injuries. Most carpometacarpal injuries were fracture-dislocations (19/27). Thumb carpometacarpal injuries had no overall side predilection; ulnar collateral ligament injuries occurred more on the right. Carpometacarpal fractures and dislocations are the most frequent motorcycle crash thumb injury, probably due to the mechanics of gripping handlebars and the high-energy force directed into the palm and against the metacarpal base.

LEVEL OF EVIDENCE

Level IV.

Engineering serendipity: High-throughput discovery of materials that resist bacterial attachment

Controlling the colonisation of materials by microorganisms is important in a wide range of industries and clinical settings. To date, the underlying mechanisms that govern the interactions of bacteria with material surfaces remain poorly understood, limiting the ab initio design and engineering of biomaterials to control bacterial attachment. Combinatorial approaches involving high-throughput screening have emerged as key tools for identifying materials to control bacterial attachment. The hundreds of different materials assessed using these methods can be carried out with the aid of computational modelling. This approach can develop an understanding of the rules used to predict bacterial attachment to surfaces of non-toxic synthetic materials. Here we outline our view on the state of this field and the challenges and opportunities in this area for the coming years.

Statement of significance

This opinion article on high throughput screening methods reflects one aspect of how the field of biomaterials research has developed and progressed. The piece takes the reader through key developments in biomaterials discovery, particularly focusing on need to reduce bacterial colonisation of surfaces. Such bacterial resistant surfaces are increasingly required in this age of antibiotic resistance. The influence and origin of high-throughput methods are discussed with insights into the future of biomaterials development where computational methods may drive materials development into new fertile areas of discovery.

New biomaterials will exhibit responsiveness to adapt to the biological environment and promote better integration and reduced rejection or infection.

Enhanced cytocompatibility and functional group content of poly(l-lysine) dendrimers by grafting with poly(oxazolines)

We report the use of polyoxazolines as materials for modifying the surface of a generation 5 l-lysine dendrimer resulting in a significant improvement in the biocompatibility properties compared to the unmodified dendrimer. The polyoxazoline coatings represent interesting alternatives to polyethylene glycol and can also offer an opportunity for increasing drug loading.

Thermoresponsive magnetic colloidal gels via surface-initiated polymerisation from functional microparticles

Novel magnetothermally responsive core–shell microparticles have been synthesized.

One-pot RAFT and fast polymersomes assembly: a ‘beeline’ from monomers to drug-loaded nanovectors

A ‘fast RAFT’ strategy that allows the engineering of drug-containing polymer vesicles in only a few hours, starting from functional monomers.

Laboratory dust generation and size-dependent characterization of metal and metalloid-contaminated mine tailings deposits

The particle size distribution of mine tailings material has a major impact on the atmospheric transport of metal and metalloid contaminants by dust. Implications to human health should be assessed through a holistic size-resolved characterization involving multidisciplinary research, which requires large uniform samples of dust that are difficult to collect using conventional atmospheric sampling instruments. To address this limitation, we designed a laboratory dust generation and fractionation system capable of producing several grams of dust from bulk materials. The equipment was utilized in the characterization of tailings deposits from the arsenic and lead-contaminated Iron King Superfund site in Dewey-Humboldt, Arizona. Results show that metal and metalloid contaminants are more concentrated in particles of < 10 μm aerodynamic diameter, which are likely to affect surrounding communities and ecosystems. In addition, we traced the transport of contaminated particles from the tailings to surrounding soils by identifying Pb and Sr isotopic signatures in soil samples. The equipment and methods developed for this assessment ensure uniform samples for further multidisciplinary studies, thus providing a tool for comprehensive representation of emission sources and associated risks of exposure.

The vitamin B12 analog cobinamide is an effective hydrogen sulfide antidote in a lethal rabbit model

BACKGROUND AND PURPOSE

Hydrogen sulfide (H2S) is a highly toxic gas for which no effective antidotes exist. It acts, at least in part, by binding to cytochrome c oxidase, causing cellular asphyxiation and anoxia. We investigated the effects of three different ligand forms of cobinamide, a vitamin B12 analog, to reverse sulfide (NaHS) toxicity.

METHODS

New Zealand white rabbits received a continuous intravenous (IV) infusion of NaHS (3 mg/min) until expiration or a maximum 270 mg dose. Animals received six different treatments, administered at the time when they developed signs of severe toxicity: Group 1-saline (placebo group, N = 9); Group 2--IV hydroxocobalamin (N = 7); Group 3--IV aquohydroxocobinamide (N = 6); Group 4--IV sulfitocobinamide (N = 6); Group 5--intramuscular (IM) sulfitocobinamide (N = 6); and Group 6-IM dinitrocobinamide (N = 8). Blood was sampled intermittently, and systemic blood pressure and deoxygenated and oxygenated hemoglobin were measured continuously in peripheral muscle and over the brain region; the latter were measured by diffuse optical spectroscopy (DOS) and continuous wave near infrared spectroscopy (CWNIRS).

RESULTS

Compared with the saline controls, all cobinamide derivatives significantly increased survival time and the amount of NaHS that was tolerated. Aquohydroxocobinamide was most effective (261.5 ± 2.4 mg NaHS tolerated vs. 93.8 ± 6.2 mg in controls, p < 0.0001). Dinitrocobinamide was more effective than sulfitocobinamide. Hydroxocobalamin was not significantly more effective than the saline control.

CONCLUSIONS

Cobinamide is an effective agent for inhibiting lethal sulfide exposure in this rabbit model. Further studies are needed to determine the optimal dose and form of cobinamide and route of administration.