Bone morphology of the femur and tibia captured by statistical shape modelling predicts rapid bone loss in acute spinal cord injury patients

We would like to thank the study participants and the clinical and research staff at the Queen Elizabeth National Spinal Injury Unit, as without them this study would not have been possible. We are grateful for the funding received from Glasgow Research Partnership in Engineering for the employment of SC during data collection for this study. We would like to thank the Royal Society of Edinburgh's Scottish Crucible scheme for providing the opportunity for this collaboration to occur. We are also indebted to Maria Dumitrascuta for her time and effort in producing inter-repeatability results for the shape models.

Vascular defects and spinal cord hypoxia in spinal muscular atrophy

© 2015 American Neurological Association. Funded by The Euan MacDonald Center for Motor Neurone Disease Research The SMA Trust Muscular Dystrophy UK The SMA Trust The SMA Trust Motor Neurone Disease Association National Institute for Health Research Great Ormond Street Hospital Biomedical Research Center Medical Research Council Great Ormond Street Hospital Charity

The construction and characterization of new permeable rho antagonists and their roles after spinal cord injury

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Development and validation of a rapid, aldehyde dehydrogenase bright-based cord blood potency assay.

Banked, unrelated umbilical cord blood provides access to hematopoietic stem cell transplantation for patients lacking matched bone marrow donors, yet 10% to 15% of patients experience graft failure or delayed engraftment. This may be due, at least in part, to inadequate potency of the selected cord blood unit (CBU). CBU potency is typically assessed before cryopreservation, neglecting changes in potency occurring during freezing and thawing. Colony-forming units (CFUs) have been previously shown to predict CBU potency, defined as the ability to engraft in patients by day 42 posttransplant. However, the CFU assay is difficult to standardize and requires 2 weeks to perform. Consequently, we developed a rapid multiparameter flow cytometric CBU potency assay that enumerates cells expressing high levels of the enzyme aldehyde dehydrogenase (ALDH bright [ALDH(br)]), along with viable CD45(+) or CD34(+) cell content. These measurements are made on a segment that was attached to a cryopreserved CBU. We validated the assay with prespecified criteria testing accuracy, specificity, repeatability, intermediate precision, and linearity. We then prospectively examined the correlations among ALDH(br), CD34(+), and CFU content of 3908 segments over a 5-year period. ALDH(br) (r = 0.78; 95% confidence interval [CI], 0.76-0.79), but not CD34(+) (r = 0.25; 95% CI, 0.22-0.28), was strongly correlated with CFU content as well as ALDH(br) content of the CBU. These results suggest that the ALDH(br) segment assay (based on unit characteristics measured before release) is a reliable assessment of potency that allows rapid selection and release of CBUs from the cord blood bank to the transplant center for transplantation.

Outcomes after Unrelated Umbilical Cord Blood Transplantation for Children with Osteopetrosis.

Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for most children with osteopetrosis (OP). Timing of HSCT is critical; therefore, umbilical cord blood transplantation (UCBT) is an attractive option. We analyzed outcomes after UCBT in 51 OP children. Median age at UCBT was 6 months. Seventy-seven percent of the cord blood grafts had 0 or 1 HLA disparity with the recipient. Conditioning regimen was myeloablative (mostly busulfan-based in 84% and treosulfan-based in 10%). Antithymocyte globulin was given to 90% of patients. Median number of total nucleated and CD34(+) cells infused was 14 × 10(7)/kg and 3.4 × 10(5)/kg, respectively. Median follow-up for survivors was 74 months. Cumulative incidence (CI) of neutrophil recovery was 67% with a median time to recovery of 23 days; 33% of patients had graft failure, 81% of engrafted patients had full donor engraftment, and 19% had mixed donor chimerism. Day 100 CI of acute graft-versus-host disease (grades II to IV) was 31% and 6-year CI of chronic graft-versus-host disease was 21%. Mechanical ventilation was required in 28%, and veno-occlusive disease was diagnosed in 16% of cases. Six-year overall survival rate was 46%. Comparative studies with other alternative donors should be performed to evaluate whether UCBT remains a valid alternative for children with OP without an HLA-matched donor.

The construction and characterization of new permeable rho antagonists and their roles after spinal cord injury

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

An Interdisciplinary Approach to the Management of Vocal Cord Dysfunction in an Elite Female Swimmer: a Case Study

Acute pulmonary disorders are commonplace within the athletic population, with exercise induced bronchoconstriction (EIB), and vocal cord dysfunction (VCD) common diagnoses. VCD is a condition that causes the adduction of the vocal folds during inhalation, causing obstruction at the larynx and thereby a severely impaired sporting performance. VCD can be brought on by laryngeal irritants, emotional and psychological stress and asthma. The gold standard of treatment for VCD centres on an interdisciplinary approach from specialists that often include a respiratory consultant, speech and language therapist (SLT) and a psychologist. The present case study details the interdisciplinary approach to the treatment of an elite female swimmer with VCD with an intervention programme that lasted nine weeks, instigated by a local general practitioner (G.P.) who chose to engage a Sport Psychology Consultant (SPC) due to the sport-specific nature of the psychological stress experienced by the individual. The steps involved in the design of the sport psychology interventions are outlined and the relationship of those interventions to the work of the other specialists is discussed. The 9 week intervention programme was aimed at reducing perfectionist tendencies and competitive state anxiety using a combination of cognitive behavioural therapy (CBT), goal-setting and imagery. Overall, the treatment programme was deemed a success as perfectionism and competitive state anxiety levels reduced over time along with the frequency of VCD occurrence. This case study demonstrates the breadth of roles that can be undertaken by a SPC and raises awareness of a complex respiratory disorder that is not yet fully understood.

Characterization of the glial scar tissue in a murine model of spinal cord compression, with focus on hyaluronan

Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of people each year. Although in recent decades significant progress has been made in relation to understanding the molecular and cellular events underlying the nervous damage, spinal cord injury is still a highly disabling condition for which there is no curative therapy. People affected by spinal cord injuries manifested dysfunction or loss, temporary or permanent, of motor, sensory and / or autonomic functions depending on the spinal lesion damaged. Currently, the incidence rate of this type of injury is approximately 15-40 cases per million people worldwide. At the origin of these lesions are: road accidents, falls, interpersonal violence and the practice of sports. In this work we placed the hypothesis that HA is one of the component of the scar tissue formed after a compressive SCI, that it is likely synthetised by the perilesional glial cells and that it might support the permeation of the glial scar during the late phase of SCI. Nowadays, much focus is drawn on the recovery of CNS function, made impossible after SCI due to the high content of sulfated proteoglycans in the extracellular matrix. Counterbalancing the ratio between these proteoglycans and hyaluronic acid could be one of the experimental therapy to re-permeate the glial scar tissue formed after SCI, making possible axonal regrowth and functional recovery. Therefore, we established a model of spinal cord compression in mice and studied the glial scar tissue, particularly through the characterization of the expression of enzymes related to the metabolism of HA and the subsequent concentration thereof at different distances of the lesion epicenter. Our results show that the lesion induced in mice shows results similar to those produced in human lesions, in terms of histologic similarities and behavioral results. but these animals demonstrate an impressive spontaneous reorganization mechanism of the spinal cord tissue that occurs after injury and allows for partial recovery of the functions of the CNS. As regards the study of the glial scar, changes were recorded at the level of mRNA expression of enzymes metabolizing HA i.e., after injury there was a decreased expression of HA synthases 1-2 (HAS 1-2) and an increase of the expression HAS3 synthase mRNA, as well as the enzymes responsible for the HA catabolism, HYAL 1-2. But the amount of HA measured through the ELISA test was found unchanged after injury, it is not possible to explain this fact only with the change of expression of enzymes. At two weeks and in response to SCI, we found synthesized HA by reactive astrocytes and probably by others like microglial cells as it was advanced by the HA/GFAP+ and HA/IBA1+ cells co-location.

Effects of hypoxic culture conditions on umbilical cord-derived human mesenchymal stem cells

Following cultivation of distinct mesenchymal stem cell (MSC) populations derived from human umbilical cord under hypoxic conditions (between 1.5% to 5% oxygen (O-2)) revealed a 2- to 3-fold reduced oxygen consumption rate as compared to the same cultures at normoxic oxygen levels (21% O-2). A simultaneous measurement of dissolved oxygen within the culture media from 4 different MSC donors ranged from 15 mu mol/L at 1.5% O-2 to 196 mu mol/L at normoxic 21% O-2. The proliferative capacity of the different hypoxic MSC populations was elevated as compared to the normoxic culture. This effect was paralleled by a significantly reduced cell damage or cell death under hypoxic conditions as evaluated by the cellular release of LDH whereby the measurement of caspase 3/7 activity revealed little if any differences in apoptotic cell death between the various cultures. The MSC culture under hypoxic conditions was associated with the induction of hypoxia-inducing factor-alpha (HIF-1 alpha) and an elevated expression of energy metabolism-associated genes including GLUT-1, LDH and PDK1. Concomitantly, a significantly enhanced glucose consumption and a corresponding lactate production could be observed in the hypoxic MSC cultures suggesting an altered metabolism of these human stem cells within the hypoxic environment.

Development of novel therapeutics and in vitro models for spinal cord injury

Spinal cord injury (SCI) is a devastating condition, which results from trauma to the cord, resulting in a primary injury response which leads to a secondary injury cascade, causing damage to both glial and neuronal cells. Following trauma, the central nervous system (CNS) fails to regenerate due to a plethora of both intrinsic and extrinsic factors. Unfortunately, these events lead to loss of both motor and sensory function and lifelong disability and care for sufferers of SCI. There have been tremendous advancements made in our understanding of the mechanisms behind axonal regeneration and remyelination of the damaged cord. These have provided many promising therapeutic targets. However, very few have made it to clinical application, which could potentially be due to inadequate understanding of compound mechanism of action and reliance on poor SCI models. This thesis describes the use of an established neural cell co-culture model of SCI as a medium throughput screen for compounds with potential therapeutic properties. A number of compounds were screened which resulted in a family of compounds, modified heparins, being taken forward for more intense investigation. Modified heparins (mHeps) are made up of the core heparin disaccharide unit with variable sulphation groups on the iduronic acid and glucosamine residues; 2-O-sulphate (C2), 6-O-sulphate (C6) and N-sulphate (N). 2-O-sulphated (mHep6) and N-sulphated (mHep7) heparin isomers were shown to promote both neurite outgrowth and myelination in the SCI model. It was found that both mHeps decreased oligodendrocyte precursor cell (OPC) proliferation and increased oligodendrocyte (OL) number adjacent to the lesion. However, there is a difference in the direct effects on the OL from each of the mHeps; mHep6 increased myelin internode length and mHep7 increased the overall cell size. It was further elucidated that these isoforms interact with and mediate both Wnt and FGF signalling. In OPC monoculture experiments FGF2 treated OPCs displayed increased proliferation but this effect was removed when co-treated with the mHeps. Therefore, suggesting that the mHeps interact with the ligand and inhibit FGF2 signalling. Additionally, it was shown that both mHeps could be partially mediating their effects through the Wnt pathway. mHep effects on both myelination and neurite outgrowth were removed when co-treated with a Wnt signalling inhibitor, suggesting cell signalling mediation by ligand immobilisation and signalling activation as a mechanistic action for the mHeps. However, the initial methods employed in this thesis were not sufficient to provide a more detailed study into the effects the mHeps have on neurite outgrowth. This led to the design and development of a novel microfluidic device (MFD), which provides a platform to study of axonal injury. This novel device is a three chamber device with two chambers converging onto a central open access chamber. This design allows axons from two points of origin to enter a chamber which can be subjected to injury, thus providing a platform in which targeted axonal injury and the regenerative capacity of a compound study can be performed. In conclusion, this thesis contributes to and advances the study of SCI in two ways; 1) identification and investigation of a novel set of compounds with potential therapeutic potential i.e. desulphated modified heparins. These compounds have multiple therapeutic properties and could revolutionise both the understanding of the basic pathological mechanisms underlying SCI but also be a powered therapeutic option. 2) Development of a novel microfluidic device to study in greater detail axonal biology, specifically, targeted axonal injury and treatment, providing a more representative model of SCI than standard in vitro models. Therefore, the MFD could lead to advancements and the identification of factors and compounds relating to axonal regeneration.

Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury.

Electrical neuromodulation of lumbar segments improves motor control after spinal cord injury in animal models and humans. However, the physiological principles underlying the effect of this intervention remain poorly understood, which has limited the therapeutic approach to continuous stimulation applied to restricted spinal cord locations. Here we developed stimulation protocols that reproduce the natural dynamics of motoneuron activation during locomotion. For this, we computed the spatiotemporal activation pattern of muscle synergies during locomotion in healthy rats. Computer simulations identified optimal electrode locations to target each synergy through the recruitment of proprioceptive feedback circuits. This framework steered the design of spatially selective spinal implants and real-time control software that modulate extensor and flexor synergies with precise temporal resolution. Spatiotemporal neuromodulation therapies improved gait quality, weight-bearing capacity, endurance and skilled locomotion in several rodent models of spinal cord injury. These new concepts are directly translatable to strategies to improve motor control in humans.

Sex cord-stromal tumours of the ovary: a comprehensive update review

Ovarian sex cord-stromal tumors are infrequent and represent approximately 7% of all primary ovarian tumors. This histopathologic ovarian tumor group differs considerably from the more prevalent epithelial ovarian tumors. Although sex cord-stromal tumors present in a broad age group, the majority tend to present as a low-grade disease that usually follows a nonaggressive clinical course in younger patients. Furthermore, because the constituent cells of these tumors are engaged in ovarian steroid hormone production (e.g., androgens, estrogens, and corticoids), sex cord-stromal tumors are commonly associated with various hormone-mediated syndromes and exhibit a wide spectrum of clinical features ranging from hyperandrogenic virilizing states to hyperestrogenic manifestations. The World Health Organization sex cord-stromal tumor classification has recently been revised, and currently these tumors have been regrouped into the following clinicopathologic entities: pure stromal tumors, pure sex cord tumors, and mixed sex cord-stromal tumors. Moreover, some entities considered in the former classification (e.g., stromal luteoma, stromal tumor with minor sex cord elements, and gynandroblastoma) are no longer considered separate tumors in the current classification. Herein, we discuss and revise the ultrasonography, computed tomography, and magnetic resonance imaging characteristics of the different histopathologic types and clinicopathologic features of sex cord-stromal tumors to allow radiologists to narrow the differential diagnosis when facing ovarian tumors.

Short Term Outcome of Neonates Born With Abnormal Umbilical Cord Arterial Blood Gases

Background: Umbilical arterial blood gas (UABG) analysis is more objective than other methods for predicting neonatal outcome. Acidemic neonates may be at risk for unfavorable outcome after birth, but all neonates with abnormal arterial blood gas (ABG) analysis do not always have poor outcome. Objectives: This study was carried out to determine the short term outcome of the neonates born with an abnormal ABG. Patients and Methods: In a cohort prospective study 120 high risk mother-neonate pairs were enrolled and UABG was taken immediately after birth. All neonates with an umbilical cord pH less than 7.2 were considered as case group and more than 7.2 as controls. Outcomes like need to resuscitation, admission to newborn services and/or NICU), seizure occurrence, hypoxic ischemic encephalopathy (HIE), delayed initiation of oral feeding and length of hospital stay were recorded and compared between the two groups. P value less than 0.05 was considered as being significant. Results: Comparison of short term outcomes between normal and abnormal ABG groups were as the fallowing: need for advanced resuscitation 4 vs. 0 (P = 0.001), NICU admission 16 vs. 4 (P = 0.001), convulsion 2 vs. 0 (P = 0.496), HIE 17 vs. 4 (P = 0.002), delay to start oral feeding 16 vs. 4 (P = 0.001), mean hospital stay 4 vs. 3 days (P = 0.001). None of the neonates died in study groups. Conclusions: An umbilical cord PH less than 7.2 immediately after birth can be used as a prognostic factor for unfavorable short term outcome in newborns.