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Rapacz-Leonard A, Kankofer M, Leonard M, Wawrzykowski J, Dąbrowska M, Raś A, Paździor-Czapula K, Janowski T. Differences in extracellular matrix remodeling in the placenta of mares that retain fetal membranes and mares that deliver fetal membranes physiologically. Placenta 2015; 36:1167-77. [PMID: 26297153 DOI: 10.1016/j.placenta.2015.07.126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/18/2015] [Accepted: 07/21/2015] [Indexed: 12/20/2022]
Abstract
INTRODUCTION In mammals, placenta separation at term may involve degradation of the extracellular matrix by matrix metalloproteinases (MMPs). The activity of MMPs is modulated by TIMPs. We hypothesized that the placentas of mares that deliver fetal membranes physiologically and those that retain fetal membranes (FMR) differ in terms of histology; mRNA expression of MMP-2 and MMP-9; protein expression of MMP-2, MMP-9, and TIMP-2; and the potential activity of both MMPs. METHODS Placenta biopsies were taken from mares (n = 9; 4 FMR, 5 controls) immediately after foal expulsion. Retention was defined as failure to expel all fetal membranes within 3 h of expulsion. All mares were monitored for time of expulsion. The degree of allantochorial/endometrial adhesion was determined in FMR mares, and biopsies from all mares were histologically examined. mRNA expression, protein immunolocalization, protein amount and potential enzyme activity were determined with RT-PCR, immunohistochemistry, Western Blotting and zymography, respectively. RESULTS FMR mares had strong to extremely strong allantochorial/endometrial adhesion, and significantly more connective tissue in the allantochorial villi than controls. The range of MMP-2 mRNA expression levels was more than 13 times greater in FMR mares than in controls. Protein content of both MMPs and TIMP-2 differed significantly between groups. The range of potential MMP-2 and MMP-9 activity was larger in FMR mares, and MMP-2 potential activity was 1.4 times higher in controls (P = 0.02). DISCUSSION These results indicate differences in extracellular matrix remodeling in FMR mares and controls, and suggest dysregulation of MMP expression and activation in FMR mares.
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Briyal S, Nguyen C, Leonard M, Gulati A. Stimulation of endothelin B receptors by IRL-1620 decreases the progression of Alzheimer's disease. Neuroscience 2015; 301:1-11. [PMID: 26022359 DOI: 10.1016/j.neuroscience.2015.05.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 05/08/2015] [Accepted: 05/18/2015] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by severe cognitive impairment that ultimately leads to death. Endothelin (ET) and its receptors have been considered as therapeutic targets for AD. Recent studies in our lab have shown that stimulation of ETB receptors provide significant neuroprotection following Aβ1-40 administration. It is possible that IRL-1620 may be neuroprotective due to angiogenesis. However, the effect of IRL-1620 on neurovascular remodeling following Aβ1-40 administration has not been established. The purpose of this study was to determine the effect of stimulation of ETB receptors by IRL-1620 on vascular and neuronal growth factors after Aβ1-40 administration. Rats were treated with Aβ1-40 (day 1, 7 and 14) in the lateral cerebral ventricles using stereotaxically implanted cannula and received three intravenous injections of IRL-1620 (an ETB agonist), and/or BQ788 (an ETB antagonist) at 2-h interval on day 8; experiments were performed on day 15. Rats were sacrificed for estimation of brain ETB receptors, vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) expression using immunofluorescence and Western blot. In the Morris swim task, amyloid-β (Aβ)-treated rats showed a significant (p<0.0001) impairment in spatial memory. Rats treated with IRL-1620 significantly (p<0.001) reduced the cognitive impairment induced by Aβ. BQ788 treatment completely blocked IRL-1620-induced improvement in cognitive impairment. IRL-1620 treatment enhanced the number of blood vessels labeled with VEGF compared to vehicle treatment. Additionally, cells showed increased (p<0.001) positive staining for NGF in IRL-1620-treated animals. ETB, VEGF and NGF protein expression significantly (p<0.001) increased in the brain of IRL-1620-treated rats as compared to vehicle. Pretreatment with BQ788 blocked the effects of IRL-1620, thus confirming the role of ETB receptors in the neurovascular remodeling actions of IRL-1620. Results of the present study demonstrate that IRL-1620 improves both acquisition (learning) and retention (memory) on the water maze task and enhances angiogenic and neurogenic remodeling. These findings indicate that the ETB receptor may be a novel therapeutic target for AD and other neurovascular degenerative disorders.
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Meagher D, O'Regan N, Ryan D, Connolly W, Boland E, O'Caoimhe R, Clare J, Mcfarland J, Tighe S, Leonard M, Adamis D, Trzepacz PT, Timmons S. Frequency of delirium and subsyndromal delirium in an adult acute hospital population. Br J Psychiatry 2014; 205:478-85. [PMID: 25359923 DOI: 10.1192/bjp.bp.113.139865] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background The frequency of full syndromal and subsyndromal delirium is understudied. Aims We conducted a point prevalence study in a general hospital. Method Possible delirium identified by testing for inattention was evaluated regarding delirium status (full/subsyndromal delirium) using categorical (Confusion Assessment Method (CAM), DSM-IV) and dimensional (Delirium Rating Scale-Revised-98 (DRS-R98) scores) methods. Results In total 162 of 311 patients (52%) screened positive for inattention. Delirium was diagnosed in 55 patients (17.7%) using DSM-IV, 52 (16.7%) using CAM and 58 (18.6%) using DRS-R98⩾12 with concordance for 38 (12.2%) individuals. Subsyndromal delirium was identified in 24 patients (7.7%) using a DRS-R98 score of 7-11 and 41 (13.2%) using 2/4 CAM criteria. Subsyndromal delirium with inattention (v. without) had greater disturbance of multiple delirium symptoms. Conclusions The point prevalence of delirium and subsyndromal delirium was 25%. There was modest concordance between DRS-R98, DSM-IV and CAM delirium diagnoses. Inattention should be central to subsyndromal delirium definitions.
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O'Neill F, Nassiri M, Lui D, Leonard M, McElwain J, Morris S. Creation of an electronic referral pathway for pelvic and acetabular fractures in times of austerity. IRISH MEDICAL JOURNAL 2014; 107:221-222. [PMID: 25226724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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Kelly ME, Leonard M, Green C, Beggs R, Cheung C, McElwain J, Morris S. Should money follow the patient: Financial implication for being the National Centre for the Treatment and Management of Pelvic and Acetabular Fractures in Ireland. Injury 2013; 44:1816-9. [PMID: 23490321 DOI: 10.1016/j.injury.2013.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/04/2012] [Accepted: 02/09/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND Pelvic and acetabular fractures are complex injuries requiring specialist treatment. Our institution is the National Centre for Treatment and Management of these injuries. AIM To audit all referrals to our institution over a 6-month period and calculate the cost incurred by being the national referral centre. METHODS Retrospective review of database, and subsequent allocation of Casemix points to assess total cost of treatment for each patient referred to our institution. RESULTS 103 patients referred with pelvic or acetabular fracture for operative management. The furthest referral distance was 181miles. Over-all, the length of stay was 15.4 days. The average inclusive cost for a referral to our unit for operative management was €16,302. CONCLUSION Pelvic and acetabular fractures are complex injuries that require specialist referral unit management. However for these units to remain sustainable money needs to "follow the patient".
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Leonard M, Tait C, Gillan A, Rai B, Byrne D, Nabi G. Impact of multiple deprivations on detection, progression and interventions in small renal masses (less than 4 cm) in a population based study. Eur J Surg Oncol 2013; 39:1157-63. [DOI: 10.1016/j.ejso.2013.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 06/17/2013] [Indexed: 10/26/2022] Open
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Chanson C, Leonard M, Thaon I, Penven E, Speyer E, Paris C. Reconnaissance des psychopathologies par les comités régionaux de reconnaissance des maladies professionnelles de Lorraine entre 2005 et 2011. ARCH MAL PROF ENVIRO 2013. [DOI: 10.1016/j.admp.2012.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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O'Neill F, Leonard M, Lui D, McElwain J, Morris S. Pelvic and acetabular fractures. IRISH MEDICAL JOURNAL 2012; 105:306. [PMID: 23240284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Patients that sustain pelvic and/or acetabular trauma in Ireland and require surgical intervention are treated at the Adelaide and Meath National Children's Hospital (AMNCH). For this study an audit was conducted of all pelvic and acetabular fractures referred to the AMNCH over a 12 month period from July 2010 to June 2011. This study was conducted with the purpose of recording the different fracture patterns, methods of injury and surgical procedures performed over this time frame. The results demonstrate that 109 patients were referred to the AMNCH with the majority of these fractures being sustained as the result of an RTA (43) or a fall from a height (45). Seventy one patients suffered an acetabular fracture while 43 patients suffered a fracture of their pelvic ring with some patients suffering both. There were 129 surgical procedures performed with 25 patients having more than one surgical procedure.
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O'Neill F, Leonard M, Morris S. A bilateral crescent and anterior ring pelvic fracture sustained by inadvertently performing the 'splits'. J Surg Case Rep 2012; 2012:11. [PMID: 24960797 PMCID: PMC3649619 DOI: 10.1093/jscr/2012.9.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A case is presented of a healthy 57 year old female who slipped and fell awkwardly into what is known in athletic terms as the front splits. As a result of her fall she sustained bilateral crescent and superior and inferior rami pelvic fractures. Successful operative fixation was undertaken by a combination of open and percutaneous techniques. To our knowledge this is the first reported case of bilateral crescent fractures, and of a pelvic fracture as a result of this mechanism of injury.
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Leonard M, Mullett H. Posterior interosseous neurectomy for extensive idiopathic avascular necrosis of the capitate in an adolescent. J Hand Surg Eur Vol 2012; 37:582-3. [PMID: 22457258 DOI: 10.1177/1753193412442291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Camargo JA, Sapin A, Nouvel C, Daloz D, Leonard M, Bonneaux F, Six JL, Maincent P. Injectable PLA-based in situ forming implants for controlled release of Ivermectin a BCS Class II drug: solvent selection based on physico-chemical characterization. Drug Dev Ind Pharm 2012; 39:146-55. [PMID: 22397675 DOI: 10.3109/03639045.2012.660952] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In situ forming implants (ISI) prepared from biodegradable polymers such as poly(D,L-lactide) (PLA) and biocompatible solvents can be used to obtain sustained drug release after parenteral administration. The aim of this work was to study the effect of several biocompatible solvents with different physico-chemical properties on the release of ivermectin (IVM), an antiparasitic BCS II drug, from in situ forming PLA-based implants. The solvents evaluated were N-methyl-2-pyrrolidone (NMP), 2-pyrrolidone (2P), triacetine (TA) and benzyl benzoate (BB). Hansen's solubility parameters of solvents were used to explain polymer/solvent interactions leading to different rheological behaviours. The stability of the polymer and drug in the solvents were also evaluated by size exclusion and high performance liquid chromatography, respectively. The two major factors determining the rate of IVM release from ISI were miscibility of the solvent with water and the viscosity of the polymer solutions. In general, the release rate increased with increasing water miscibility of the solvent and decreasing viscosity in the following order NMP>2P>TA>BB. Scanning electron microscopy revealed a relationship between the rate of IVM release and the surface porosity of the implants, release being higher as implant porosity increased. Finally, drug and polymer stability in the solvents followed the same trends, increasing when polymer-solvent affinities and water content in solvents decreased. IVM degradation was accelerated by the acid environment generated by the degradation of the polymer but the drug did not affect PLA stability.
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Elyas R, Guerra LA, Pike J, DeCarli C, Betolli M, Bass J, Chou S, Sweeney B, Rubin S, Barrowman N, Moher D, Leonard M. Is staging beneficial for Fowler-Stephens orchiopexy? A systematic review. J Urol 2010; 183:2012-8. [PMID: 20303527 DOI: 10.1016/j.juro.2010.01.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Indexed: 10/19/2022]
Abstract
PURPOSE Fowler and Stephens showed that by dividing the spermatic vessels a high intra-abdominal testis could be placed in the scrotum. Testicular atrophy is a potential complication of this technique. We conducted a systematic review to determine whether single or 2-stage Fowler-Stephens orchiopexy results in better testicular viability. MATERIALS AND METHODS We searched electronic databases, clinical trial registries and gray literature. We included reports describing boys younger than 18 years with a primary outcome of "testicular viability and position." We performed a meta-analysis using random effects models. Heterogeneity was assessed using forest plot and I(2) statistic. RESULTS We identified 1,807 citations and included 61 articles. Single stage Fowler-Stephens orchiopexy was discussed in 9 articles, a 2-stage procedure in 36 and both approaches in 16. There were no randomized controlled trials, and most studies were cohort or case series. The pooled estimate of success rates was 80% for single stage Fowler-Stephens orchiopexy (95% CI 75 to 86) and 85% for 2-stage Fowler-Stephens orchiopexy (95% CI 81 to 90). The pooled odds ratio of single stage vs 2-stage Fowler-Stephens orchiopexy was 2.0 (95% CI 1.1 to 3.9) favoring the 2-stage procedure. There was no difference in the success rate between laparoscopic and open techniques in either single or 2-stage Fowler-Stephens orchiopexy. There was no evidence of asymmetry on the funnel plot. There were no complications reported with single stage, while ileus, hematoma and infection were the most common complications with 2-stage Fowler-Stephens orchiopexy. CONCLUSIONS Both techniques have a fairly high success rate but 2-stage Fowler-Stephens orchiopexy appears to carry a higher rate of success than the single stage approach (85% vs 80%, OR 2 in favor of 2-stage). Laparoscopic and open techniques had the same success rate. However, the level of evidence of the studies was low, and a study of a more robust design, such as a randomized controlled trial, should be performed.
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Abstract
The objective of this paper is to highlight the potential role of eye tracking technology (ETT) in the assessment of delirious patients. Delirium occurs in one in five general hospital admissions (Siddiqi, 2006) and its frequency will increase as society gets older. Despite its frequency and significant independent impact upon morbidity and mortality, delirium remains under studied and is frequently missed, detected late, or misdiagnosed (Farrell & Ganzani, 1995; Inouye, 2001; Kakuma, 2003). Detection is a key target for both clinical and research efforts. Assessment of attention is key to diagnosing delirium, yet nurses and non-research medical staff often fail to correctly identify inattention (Inouye et al., 2001; Lemiengre et al., 2006; Ryan et al., 2008). Eye tracking measures have been used in a plethora of key areas of psychiatric research (Crawford et al., 2005; Corden, Chilvers, & Skuse, 2008; Hardin, Schroth, Pine, & Ernst, 2007; Holzman, Leonard, Proctor, & Hughes, 1973), and provide an accurate and non-invasive method in the assessment of cognitive function. The potential of ETT for direct clinical applications in the assessment of attention and comprehension, key cognitive symptoms of delirium, are promising. This paper considers potential new approaches which recent advancements in non-invasive ETT may bring to the examination and understanding of delirium.
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Ryan K, Leonard M, Guerin S, Donnelly S, Conroy M, Meagher D. Validation of the confusion assessment method in the palliative care setting. Palliat Med 2009; 23:40-5. [PMID: 19010967 DOI: 10.1177/0269216308099210] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The Confusion Assessment Method (CAM) is widely used in the palliative care setting despite the fact that its performance in this population has not been validated. The aim of the study was to determine the sensitivity and specificity of the CAM when used by Non-Consultant Hospital Doctors (NCHDs) working in a specialist palliative care unit. A pilot phase was performed in which NCHDs received a 1-hour training session based on the original CAM training manual. 32 patients underwent 33 assessments in the pilot phase but the sensitivity of the CAM was only 0.5 (0.22-0.78) and specificity was 1.0 (0.81-1.0). An 'enhanced' training programme was devised that took place over two 1-hour sessions and involved case-based learning focused on the areas where the NCHDs were experiencing difficulty. 52 patients underwent 54 assessments in the main phase of the study and the performance of the CAM improved significantly. Sensitivity was 0.88 (0.62-0.98) and specificity was 1.0 (0.88-1.0). The results suggest that the CAM is a valid screening tool for delirium in the palliative care setting but its performance is dependent on the skill of the operator. NCHDs require a certain standard of training before becoming proficient in its use.
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Leonard M, Raju B, Conroy M, Donnelly S, Trzepacz PT, Saunders J, Meagher D. Reversibility of delirium in terminally ill patients and predictors of mortality. Palliat Med 2008; 22:848-54. [PMID: 18755829 DOI: 10.1177/0269216308094520] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this study, factors related to reversibility and mortality in consecutive cases of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) delirium [n = 121] occurring in palliative care patients were evaluated. Delirium was assessed with the revised Delirium Rating Scale (DRS-R98) and Cognitive Test for Delirium (CTD). Patients were followed until recovery from delirium or death. In all, 33 patients (27%) recovered from delirium before death. Mean time until death was 39.7 +/- 69.8 days in patients with reversible delirium [n = 33] versus 16.8 +/- 10.0 days in those with irreversible delirium [n = 88; P < 0.01]. DRS-R98 and CTD scores were higher in irreversible delirium (P < 0.001) with greater disturbances of sleep, language, long-term memory, attention, vigilance and visuospatial ability. Irreversible delirium was associated with greater disturbance of CTD attention and higher DRS-R98 visuospatial function. Survival time was predicted by CTD score (P < 0.001), age (P = 0.01) and organ failure (P = 0.01). Delirium was not necessarily a harbinger of imminent death. Less reversible delirium involved greater impairment of attention, vigilance and visuospatial function. Survival time is related to age, severity of cognitive impairment and evidence of organ failure.
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Leonard M. An overview and comparative analysis of singing on the nest in North American birds. CAN J ZOOL 2008. [DOI: 10.1139/z08-092] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bird song is used to defend territories and attract mates and tends to make the singer conspicuous. Singing on the nest (SOTN) has been mentioned since 1904 but has remained largely unexplored. This behavior occurs in 10.1% of breeding birds of North America. Factors that predict the likelihood of SOTN for any species include colonial nesting, incubation sharing and feeding, and taxonomic family. If SOTN is as conspicuous as other forms of singing, this behavior may incur significant costs, such as increased nest predation and parasitism. Data collected from the literature regarding nest vocalizations of adult birds (calls and songs) showed those costs were not significantly different between vocalizing and silent birds. There was greater variance in the rates of nest predation and parasitism for vocalizing birds, which may suggest greater risk. The function(s) of SOTN are not well understood and are mostly untested. Several hypotheses are presented to explain this behavior. This is the first attempt to examine this behavior in any depth and demonstrates the need for further research to explore its function(s) and consequences.
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Leonard M, Magill P, Khayyat G. Minimally-invasive treatment of high velocity intra-articular fractures of the distal tibia. INTERNATIONAL ORTHOPAEDICS 2008; 33:1149-53. [PMID: 18654775 DOI: 10.1007/s00264-008-0629-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 05/10/2008] [Accepted: 06/02/2008] [Indexed: 11/25/2022]
Abstract
The pilon fracture is a complex injury. The purpose of this study was to evaluate the outcome of minimally invasive techniques in management of these injuries. This was a prospective study of closed AO type C2 and C3 fractures managed by early (<36 hours) minimally invasive surgical intervention and physiotherapist led rehabilitation. Thirty patients with 32 intra-articular distal tibial fractures were treated by the senior surgeon (GK). Our aim was to record the outcome and all complications with a minimum two year follow-up. There were two superficial wound infections. One patient developed a non-union which required a formal open procedure. Another patient was symptomatic from a palpable plate inferiorly. An excellent AOFAS result was obtained in 83% (20/24) of the patients. Early minimally invasive reduction and fixation of complex high velocity pilon fractures gave very satisfactory results at a minimum of two years follow-up.
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Aumelas A, Serrero A, Durand A, Dellacherie E, Leonard M. Nanoparticles of hydrophobically modified dextrans as potential drug carrier systems. Colloids Surf B Biointerfaces 2007; 59:74-80. [PMID: 17560095 DOI: 10.1016/j.colsurfb.2007.04.021] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 04/24/2007] [Accepted: 04/24/2007] [Indexed: 10/23/2022]
Abstract
Nanoparticles combining a hydrophobically modified dextran core and a polysaccharide surface coverage were elaborated. Their suitability for applications like drug delivery was evaluated. The selected polysaccharide, dextran, was chemically modified by the covalent attachment of hydrocarbon groups (aliphatic or aromatic) via the formation of ether links. According to the extent of modification, either water-soluble or water-insoluble dextran derivatives were obtained. The latter exhibited solubility in organic solvents like tetrahydrofuran or dichloromethane saturated with water. Water-soluble dextran derivatives were used as polymeric surfactants for the control of nanoparticles surface characteristics. Nanoparticles were prepared either by o/w emulsion or solvent-diffusion methods. The size and surface properties of dextran nanoparticles were correlated to processing conditions. The stability of colloidal suspensions was examined as a function of ionic strength and related to the particle surface characteristics. The redispersability of freeze-dried suspensions without the addition of cryoprotectant was demonstrated. Finally, the degradability of modified dextrans was compared to that of starting dextran, after enzymatic hydrolysis in the presence of dextranase.
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Keays M, Guerra L, Mihill J, Raju G, Al-Asheeri N, Geier P, Gaboury I, Matzinger M, Pike J, Leonard M. MP-02.02: Reliability and validity assessment of society for fetal urology ultrasound grading system for hydronephrosis. Urology 2007. [DOI: 10.1016/j.urology.2007.06.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Guerra L, Moher D, Barrowman N, Sampson M, Pike J, Leonard M. POS-02.119: Intravesical oxybutynin for children with poorly compliant neurogenic bladders: a Systematic Review. Urology 2007. [DOI: 10.1016/j.urology.2007.06.1055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Baumann B, McCans K, Stahmer S, Leonard M, Shults J, Holmes W. Bladder Ultrasound Increases Catheterization Success in Pediatric Patients. Acad Emerg Med 2007. [DOI: 10.1197/j.aem.2007.03.1173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Leonard M, Jones A, Hernandez-Nino J, Kline J. Determination of the Effect of In-vitro Time, Temperature and Tourniquet Use on Whole Blood Venous Point-of-care Lactate Concentrations. Acad Emerg Med 2007. [DOI: 10.1197/j.aem.2007.03.1233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Baumann B, McCans K, Stahmer S, Leonard M, Shults J, Holmes W. Caregiver and Healthcare Provider Satisfaction with Ultrasound-Guided Pediatric Bladder Catheterization. Acad Emerg Med 2007. [DOI: 10.1197/j.aem.2007.03.971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Leonard M, Sproule J, McCormack D. Paediatric spinal trauma and associated injuries. Injury 2007; 38:188-93. [PMID: 17140578 DOI: 10.1016/j.injury.2006.09.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 07/17/2006] [Accepted: 09/27/2006] [Indexed: 02/02/2023]
Abstract
Paediatric spinal injuries, although rare (1-2% of all paediatric fractures) are associated with the highest mortality rate of all orthopaedic injuries in children. The low incidence is due, not only to the plasticity of the paediatric spine, but also the difficulty of diagnosis and the usually severe if not fatal associated injuries. A 10-year (1995-2004) retrospective study was undertaken of all patients treated for a spinal injury at our institute, which functions as both an acute care centre and a tertiary referral centre for seriously injured children. The study was performed in order to highlight the unique features of spinal injuries in children, and to assess the incidence and pattern of associated injuries. A total of 40 patients had a documented diagnosis of spinal injury. The charts and radiographs of all patients were retrieved and reviewed. The median age was 10 years (range 2-15) and 25 were male. The causative factors were motor vehicle accidents in 16, falls in 14, sport injuries in 7 and assaults in 3. Over 65% of the children sustained one or more associated injuries, the mean injury severity score was 18.95. There were two deaths, both in patients with severe multiple trauma and associated spinal fracture. Treatment included closed reduction in two patients and posterior open reduction and stabilisation in two patients, with one of these also requiring decompression. Spinal injuries in children differ from adults due primarily to the biomechanical and anatomical features of the developing musculoskeletal system. When a spinal injury is identified on initial radiographic or clinical evaluation of an injured child, one should have a high index of suspicion that concurrent, potentially life-threatening injuries may be present.
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Gaire B, Sayler AM, Wang PQ, Johnson NG, Leonard M, Parke E, Carnes KD, Ben-Itzhak I. Determining the absolute efficiency of a delay line microchannel-plate detector using molecular dissociation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:024503. [PMID: 17578132 DOI: 10.1063/1.2671497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We present a method to measure the absolute detection efficiency of a delay-line microchannel-plate detector using the breakup of diatomic molecular ions. This method provides the absolute total detection efficiency, as well as the individual efficiency for each signal of the detector. The method is based on the fact that molecular breakup always yields two hits on the detector, but due to finite detection efficiency some of these events are recorded as single particles while others are detected in pairs. We demonstrate the method by evaluating the detection efficiency for both timing and position signals of a delay-line detector using laser-induced dissociation of molecular ions. In addition, the detection efficiency as a function of position has been determined by dividing the detector into sectors.
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