Using Statistical Shape and Appearance Modelling to characterise the 3D shape and material properties of human lumbar vertebrae: A proof of concept study

Patient variation affects the outcomes of a range of spinal interventions, from disc replacement to vertebral fixation and vertebroplasty. Statistical Shape and Appearance Modelling (SSAM) can be used to describe anatomical variation and pathological differences within the population. To better understand how bone density and shape variation affect load transfer with respect to surgical treatments, Finite Element (FE) models can be generated from a SSAM. The aim for this study is to understand whether geometric and density variation as well as multiple vertebral levels can be incorporated into a single SSAM and whether this can be used to investigate the relationships between, and effects of, the various modes of variation. FE models of 14 human lumbar vertebrae that had been μCT imaged and validated through experimental testing were used as input specimens for a SSAM. The validity of the SSAM was evaluated by using principal component analysis to identify the primary modes of geometric and bone density variation and comparing to those in the input set. FE models were generated from the SSAM to examine the response to loading. The mean error between the input set and generated models for volume, mean density and FE compressive stiffness were 10%, 3% and 10% respectively. Principal Component (PC) 1 captured the majority of the bone density variation. The remaining PCs described specific geometric variation. The FE models generated from the SSAM showed the variations in vertebral stiffness as a result of complex relationships between bone density and shape. The SSAM created has limited data for its input set, however, it acts as a proof of concept for the novel combination of material and shape variation into a single shape model. This approach and the tools developed can be applied to wider patient groups and treatment scenarios to improve patient stratification and to optimise treatments.

Emotion production of facial expressions: A comparison of deaf and hearing children

The production of facial expressions is an important skill that allows children to share and adapt emotions during social interactions. While deaf children are reported to show delays in their social and emotion understanding, the way in which they produce facial expressions of emotions has been relatively unexplored. The present study investigated the production of facial expressions of emotions by young congenitally deaf children. Six facial expressions of emotions produced by 5 congenitally deaf children and 5 hearing children (control group) were filmed across three tasks: 1) voluntarily posed expression of emotion 2) responding to social stories 3) intentionally mimicking expressions of emotion. The recorded videos were analysed using a software based of the Facial Action Coding System (FACS), and then judged by adult raters using two different scales: according to the emotion elicited (i.e. accuracy) and the intensity of the emotion produced. The results of both measurement scales showed that all children (deaf and hearing) were able to produce socially recognisable prototypical configuration of facial expressions. However, the deaf children were rated by adults as expressing their emotions with greater intensity compared to the hearing children. The results suggest deaf children may show more exaggerated facial expressions of emotion, possibly to avoid any ambiguity in communication.

0665 Bilateral Hypoglossal Nerve Stimulation for Treatment of Obstructive Sleep Apnea

Introduction

Hypoglossal Nerve Stimulation (HGNS) decreases obstructive sleep apnea (OSA) severity by contracting the tongue and decreasing upper airway collapsibility. This study assessed the safety and effectiveness of a new implantable device that delivers bilateral HGNS: the Genio™ system.

Methods

The BLAST OSA study (BiLAteral Hypoglossal Nerve Stimulation for Treatment of Obstructive Sleep Apnea), was a prospective, open-label, non-randomized, single arm treatment study conducted at eight centres in three countries (Australia, France, UK). Primary outcomes were the incidence of device-related Serious Adverse Events (SAEs) and change in the Apnea-Hypopnea Index (AHI). The secondary outcome was change in the 4% Oxygen Desaturation Index (ODI). Additional outcomes included measures of sleepiness, quality of life, snoring, and device use. Participants were eligible if: 21-75 years old; BMI ≤ 32 kg/m2; obstructive AHI 20-60 events/hr and combined central and mixed AHI < 10 events/hr; no positional OSA; no Complete Concentric Collapse of the soft palate during Drug Induced Sleep Endoscopy; and failed to tolerate or accept Positive Airway Pressure treatments.

Results

27 participants were implanted (63% male, aged 55.9±12.0 years, BMI 27.4±3.0 kg/m2). 22 completed the protocol. At 6 months, AHI decreased from 23.7±12.2 to 12.9±10.1 events/hr [p<0.001]; and ODI decreased from 19.1±11.2 to 9.8±6.9 events/hr [p<0.001]. Daytime sleepiness (ESS, p=0.011) and sleep-related quality of life (FOSQ-10, p=0.016) both significantly improved. 91% of participants reported using their device >5 days per week, and 77% used it >5 hours per night. The number of bed partners reporting disruptive snoring decreased from 96% to 35%. No device-related SAE occurred.

Conclusion

In a targeted population of individuals with moderate-to-severe OSA, the Genio system reduced OSA severity and sleepiness, improved quality of life, and was associated with high adherence and an acceptable safety profile.

Support

This study trial was funded by Nyxoah S.A. This trial was registered with ClinicalTrials.gov, number NCT03048604.

Protection against maternal infection-associated fetal growth restriction: proof-of-concept with a microbial-derived immunomodulator

Infection-associated inflammatory stress during pregnancy is the most common cause of fetal growth restriction and/or miscarriage. Treatment strategies for protection of at-risk mothers are limited to a narrow range of vaccines, which do not cover the bulk of the common pathogens most frequently encountered. Using mouse models, we demonstrate that oral treatment during pregnancy with a microbial-derived immunomodulator (OM85), currently used clinically for attenuation of infection-associated airway inflammatory symptoms in infants-adults, markedly reduces risk for fetal loss/growth restriction resulting from maternal challenge with bacterial lipopolysaccharide or influenza. Focusing on LPS exposure, we demonstrate that the key molecular indices of maternal inflammatory stress, notably high levels of RANTES, MIP-1α, CCL2, KC, and G-CSF (granulocyte colony-stimulating factor) in gestational tissues/serum, are abrogated by OM85 pretreatment. Systems-level analyses conducted in parallel using RNASeq revealed that OM85 pretreatment selectively tunes LPS-induced activation in maternal gestational tissues for attenuated expression of TNF, IL1, and IFNG-driven proinflammatory networks, without constraining Type1-IFN-associated networks central to first-line antimicrobial defense. This study suggests that broad-spectrum protection-of-pregnancy against infection-associated inflammatory stress, without compromising capacity for efficient pathogen eradication, represents an achievable therapeutic goal.

Spontaneously arising concurrent ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma in a rhesus macaque (Macaca mulatta)

A 25-year-old, female rhesus macaque (Macaca mulatta) presented with a history of weight loss despite a normal appetite and supportive care. The animal was humanely destroyed due to poor prognosis. Post-mortem examination revealed a focally extensive, firm, white annular constriction at the ileocaecal junction and an incidental finding of a pale white nodule approximately 0.8 cm in diameter in the left renal pelvis. Based on the microscopical findings, ileocaecal adenocarcinoma and renal pelvis transitional cell carcinoma (TCC) were diagnosed. The use of cytokeratin (CK)-7 and -20 and uroplakin III as potential renal TCC markers was evaluated. The neoplastic cells were labelled intensely with antibodies to uroplakin III, but not to CK-7 or -20. Spontaneous intestinal adenocarcinoma has been documented in the rhesus macaque, but concurrent renal pelvis TCC is highly unusual.

Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient

La-doped zirconia films, deposited by ALD at 300°C, were found to be amorphous with dielectric constants (k-values) up to 19. A tetragonal or cubic phase was induced by post-deposition annealing (PDA) at 900°C in both nitrogen and air. Higher k-values (~32) were measured following PDA in air, but not after PDA in nitrogen. However, a significant dielectric relaxation was observed in the air-annealed film, and this is attributed to the formation of nano-crystallites. The relaxation behavior was modeled using the Curie-von Schweidler (CS) and Havriliak-Negami (HN) relationships. The k-value of the as-deposited films clearly shows a mixed CS and HN dependence on frequency. The CS dependence vanished after annealing in air, while the HN dependence disappeared after annealing in nitrogen.

Metal organic chemical vapour deposition of vertically aligned ZnO nanowires using oxygen donor adducts

Vertically aligned zinc oxide (ZnO) nanowires (NWs) have been grown by liquid injection Metal Organic Chemical Vapour Deposition, using oxygen donor adducts of Me2Zn. The growth and characterisation of the nanowires grown using [Me2Zn(L)] where L = monodentate ethers, tetrahydrofuran (C4H8O) (1), tetrahydropyran (C5H10O) (2), furan (C4H4O) (3) and the bidentate ethers, 1,2-dimethoxyethane (C4H12O2,) (4) 1,4-dioxane (C4H8O2) (5) and 1,4-thioxane (C4H8SO) (6) is discussed. Single crystal X-ray structures of (4), (5), (6) have been established and are included here. The ZnO NWs were deposited in the absence of a seed catalyst on Si(111) and F-doped SnO2/glass substrates over the temperature range 350-600 degrees C. X-ray diffraction (XRD) data shows that the nanowires grown from all adduct precursors were deposited in the wurtzitic phase.

Digital metastases of giant cell rich malignant fibrous histiocytoma

Background. Metastatic spread of soft tissue sarcomas to the digits is extremely rare and metastasis of MFH to the fingers and toes has not been documented.Purpose. We present two case reports of metastatic spread from a giant cell rich malignant fibrous histiocytoma to the digits and discuss their management.

Content variability of active drug substance in compounded oral 3,4-diaminopyridine products

WHAT IS KNOWN AND OBJECTIVE

3,4-diaminopyridine (3,4-DAP; amifampridine) is used for symptomatic treatment of Lambert-Eaton myasthenic syndrome. Until recently, it was only available as a compounded product, which raises safety concerns because of possible high variability in active drug substance content. The objective of this study was to evaluate the variability in dosage form weight, active content variability and impurity of compounded oral 3,4-DAP drug products.

METHODS

Ten samples each of 9 oral 3,4-DAP compounded products were weighed, extracted with water and the 3,4-DAP content determined by ultra high-performance liquid chromatography.

RESULTS AND DISCUSSION

Variability in dosage form weight ranged from 0·81% relative standard deviation (RSD) to 4·82% RSD. In the 90 samples tested, 3,4-DAP content ranged from 22·2% to 125·2% of declared label content. All 10 samples of one compounded product had active drug substance content well below the declared label content (35·0%, 51·7% RSD). No compounded product achieved the Good Manufacturing Practice (GMP) standard of 95-105% range limit of declared label content; one achieved 90-110%, and four others achieved 80-120% of declared content for all 10 samples. There was no evidence of a significant presence of degradation products or related substances in any compounded product.

WHAT IS NEW AND CONCLUSION

Compounded 3,4-DAP products are subject to considerable variability in active drug substance content. This variability seems to be principally because of heterogeneous formulated material rather than variation in dosage form weight.

Control of Growth Dynamics by Molecular Design in the MOCVD of Electronic Ceramics

The MOCVD technique is being used increasingly for the deposition of electronic ceramics such as Pb(Zr,Ti)O3, Ta2O5 and TiO2. For the mil potential of MOCVD to be realised, it is sometimes necessary to modify existing precursors so that process parameters in the MOCVD process are optimised. In this paper we describe our approach to “molecular design” and discuss how the substitution of simple alkoxide groups by β-diketonates or donor-functionalised ligands can result in precursors with improved physical properties and optimum MOCVD characteristics.

The optical properties of vertically aligned ZnO nanowires deposited using a dimethylzinc adduct

The optical properties of zinc oxide nanowires are critically influenced by the growth process. Herein, we describe a metal-organic chemical vapour deposition (MOCVD) process for the growth of ZnO nanowires with improved optical properties. A tetrahydrofuran adduct is used to control the reactivity of dimethylzinc to enable this. Vertically aligned zinc oxide nanowires have been grown on Si(111) substrates by liquid injection MOCVD, using a solution of [Me(2)Zn(tetrahydrofuran)] in the presence of oxygen. The ZnO morphology becomes nanowire-like in a narrow temperature range centred about 500 degrees C. Above and below this temperature range, the ZnO is deposited in the form of polycrystalline films. The ZnO nanowires grow from a polycrystalline nucleation layer, with the (0002) c-axis parallel to the Si[111] substrate orientation. High-resolution electron microscopy reveals a highly crystalline nanowire microstructure. Resonance enhanced ultraviolet Raman spectroscopy shows that the ratio of first- and second-order longitudinal optic modes is commensurate with electron-phonon coupling effects observed previously in ZnO nanostructures. Photoluminescence exhibits intense near band-edge emission with a full width at half-maximum of 110 meV at room temperature and shows negligible defect-related visible emission.

The placebo effect and its determinants in osteoarthritis: meta-analysis of randomised controlled trials

OBJECTIVE

To examine the placebo effect and its potential determinants in the treatment of osteoarthritis (OA) via a systematic literature search of Medline, EMBASE, Scientific Citation Index, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library.

METHODS

Randomised placebo controlled trials in OA were included. The placebo effect was defined as the overall change from baseline in the placebo group. It was estimated as the effect size (ES; the standard mean difference between baseline and endpoint) and this was compared with the ES obtained from untreated control. ES for pain was the primary outcome. Statistical pooling was undertaken as appropriate and 95% CIs were used for comparison. Quality of trials was assessed and potential determinants of placebo effect were examined using multiple regression analysis. The partial regression coefficient (beta) was used to present the adjusted size of the association.

RESULTS

We identified 198 trials with 193 placebo groups (16 364 patients) and 14 untreated control groups (1167 patients) that met our inclusion criteria. These included a range of therapies (non-pharmacological, pharmacological and surgical treatments). Placebo was effective at relieving pain (ES 0.51, 95% CI 0.46 to 0.55 for the placebo group and 0.03, 95% CI -0.13 to 0.18 for untreated control). Placebo was also effective at improving function and stiffness. The pain-relieving effect increased when the active treatment effect (beta=0.38, p<0.001), baseline pain (0.006, p=0.014) and sample size (0.001, p=0.004) increased, and when placebo was given through injections/needles (0.144, p=0.020).

CONCLUSION

Placebo is effective in the treatment of OA, especially for pain, stiffness and self-reported function. The size of this effect is influenced by the strength of the active treatment, the baseline disease severity, the route of delivery and the sample size of the study.

Development of specimen-specific finite element models of human vertebrae for the analysis of vertebroplasty

The aim of this study was to determine the accuracy of specimen-specific finite element models of untreated and cement-augmented vertebrae by direct comparison with experimental results. Eleven single cadaveric vertebrae were imaged using micro computed tomography (mCT) and tested to failure in axial compression in the laboratory. Four of the specimens were first augmented with PMMA cement to simulate a prophylactic vertebroplasty. Specimen-specific finite element models were then generated using semi-automated methods. An initial set of three untreated models was used to determine the optimum conversion factors from the image data to the bone material properties. Using these factors, the predicted stiffness and strength were determined for the remaining specimens (four untreated, four augmented). The model predictions were compared with the corresponding experimental data. Good agreement was found with the non-augmented specimens in terms of stiffness (root-mean-square (r.m.s.) error 12.9 per cent) and strength (r.m.s. error 14.4 per cent). With the augmented specimens, the models consistently overestimated both stiffness and strength (r.m.s. errors 65 and 68 per cent). The results indicate that this method has the potential to provide accurate predictions of vertebral behaviour prior to augmentation. However, modelling the augmented bone with bulk material properties is inadequate, and more detailed modelling of the cement region is required to capture the bone—cement interactions if the models are to be used to predict the behaviour following vertebroplasty.

Disparities in joint replacement utilization: a quality of care issue

Although total joint replacement is an effective treatment option for end-stage lower extremity osteoarthritis, racial disparities in joint replacement utilization have been well documented. These disparities may be due in part to patient-level factors such as willingness to consider joint replacement and worse expectations of joint replacement outcomes. In addition, African-Americans may have worse outcomes after total joint replacement and are more likely to have surgery performed by surgeons with lower volumes or in hospitals with lower volumes. All of these issues may be considered concerns with the quality of care delivered to African-Americans with osteoarthritis.

Elimination of transmissible spongiform encephalopathy infectivity and decontamination of surgical instruments by using radio-frequency gas-plasma treatment

It has now been established that transmissible spongiform encephalopathy (TSE) infectivity, which is highly resistant to conventional methods of deactivation, can be transmitted iatrogenically by contaminated stainless steel. It is important that new methods are evaluated for effective removal of protein residues from surgical instruments. Here, radio-frequency (RF) gas-plasma treatment was investigated as a method of removing both the protein debris and TSE infectivity. Stainless-steel spheres contaminated with the 263K strain of scrapie and a variety of used surgical instruments, which had been cleaned by a hospital sterile-services department, were examined both before and after treatment by RF gas plasma, using scanning electron microscopy and energy-dispersive X-ray spectroscopic analysis. Transmission of scrapie from the contaminated spheres was examined in hamsters by the peripheral route of infection. RF gas-plasma treatment effectively removed residual organic residues on reprocessed surgical instruments and gross contamination both from orthopaedic blades and from the experimentally contaminated spheres. In vivo testing showed that RF gas-plasma treatment of scrapie-infected spheres eliminated transmission of infectivity. The infectivity of the TSE agent adsorbed on metal spheres could be removed effectively by gas-plasma cleaning with argon/oxygen mixtures. This treatment can effectively remove 'stubborn' residual contamination on surgical instruments.

Cost effectiveness of a two-year home exercise program for the treatment of knee pain

OBJECTIVE

To assess the cost effectiveness of a 2-year home exercise program for the treatment of knee pain.

METHODS

A total of 759 adults aged > or = 45 years were randomized to receive exercise therapy, monthly telephone contact, exercise therapy and telephone contact, or no intervention. Efficacy was measured using self-reported knee pain at 2 years. Costs to both the National Health Service and to the patient were included.

RESULTS

Exercise therapy was associated with higher costs and better effectiveness. Direct costs for the interventions were pound 112 for the exercise program and pound 61 for the monthly telephone support. Participants allocated to receive exercise therapy were significantly more likely to incur higher medical costs than those in the no-exercise groups (mean difference pound 225; 95% confidence interval pound 218, pound 232; P < 0.001).

CONCLUSION

Exercise therapy is associated with improvements in knee pain, but the cost of delivering the exercise program is unlikely to be offset by any reduction in medical resource use.

Preoperative chemoradiotherapy and total mesorectal excision surgery for locally advanced rectal cancer: correlation with rectal cancer regression grade

PURPOSE

Preoperative long-course chemoradiotherapy is recommended for rectal carcinoma when there is concern that surgery alone may not be curative. Downstaging of the tumor can be measured as rectal cancer regression grade (1-3) and may be of importance when estimating the prognosis. The aim of this study was to look at the long-term results of tumor regression in patients receiving long-course chemotherapy before surgical resection of rectal cancer.

METHODS

We reviewed those patients who received preoperative chemoradiotherapy followed by surgical resection for carcinoma of the mid rectum or distal rectum found to be stage T3/4 between January 1995 and November 1999. Patients received 45 to 50 Gy irradiation in 2-Gy fractions and an infusion of 5-fluorouracil. Surgical specimens were assessed for rectal cancer regression grade. Patients were followed up routinely with clinical examination, computed tomography, and colonoscopy.

RESULTS

Sixty-five patients with a mean age 65 (range, 32-83) years underwent chemoradiotherapy before surgical resection. Thirty patients (46 percent) were classified as rectal cancer regression Grade 1, with 9 patients (14 percent) having complete sterilization of the tumor. Fifty-three patients (82 percent) underwent a curative resection. Overall survival, with a median follow-up of 39 (range, 24-83) months, was 67 percent and was associated with tumor downstaging. The local recurrence rate was 5.8 percent in those patients who underwent a curative resection and was significantly lower with rectal cancer regression Grade 1 tumors (P = 0.03). Eight of nine patients (89 percent) whose tumor had been sterilized were alive and well with no recurrence of tumor at a median follow-up of 41 (range, 24-70) months.

CONCLUSIONS

Preoperative chemoradiotherapy resulted in significant regression of tumor. Overall survival was high and was associated with downstaging of tumor. The local recurrence rate was significantly lower with rectal cancer regression Grade 1 tumors and was not seen in patients with sterilized tumors.

Investigation of microstructural features in regenerating bone using micro computed tomography

We illustrate some of the uses of micro-computed tomography (micro-CT) to study tissue-engineered bone using a micro-CT facility for imaging and visualizing biomaterials in three dimensions (3-D). The micro-CT is capable of acquiring 3D X-ray CT images made up of 2000(3) voxels on specimens up to 5 cm in extent with resolutions down to 2 microm. This allows the 3-D structure of tissue-engineered materials to be imaged across orders of magnitude in resolution. This capability is used to examine an explanted, tissue-engineered bone material based on a polycaprolactone scaffold and autologous bone marrow cells. Imaging of the tissue-engineered bone at a scale of 1 cm and resolutions of 10 microm allows one to visualize the complex ingrowth of bone into the polymer scaffold. From a theoretical viewpoint the voxel data may also be used to calculate expected mechanical properties of the tissue-engineered implant. These observations illustrate the benefits of tomography over traditional techniques for the characterization of bone morphology and interconnectivity. As the method is nondestructive it can perform a complimentary role to current histomorphometric techniques.