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Publication
Journal: Medical Physics
April/1/2010
Abstract
OBJECTIVE
Recently, several authors have shown contrast improvements in megavoltage portal imaging and cone-beam computed tomography using low atomic number (Z) targets. This work compliments previous studies by investigating the effects of varying different beam production parameters including target atomic number, target thickness, and incident electron energy on spatial resolution.
METHODS
Target materials of beryllium, aluminum, and tungsten were investigated over a range of thicknesses between 10% and 100% of the continuous slowing down approximation range of electrons. Incident electron kinetic energies of 4.5 and 7.0 MeV were used, in conjunction with custom targets installed above the carousel of a modern radiotherapy linear accelerator. Monte Carlo simulations of the accelerator were constructed and compared to the experimental results.
RESULTS
The results showed that thinner targets, as well higher incident electron energies, generally produce more favorable modulation transfer function (MTF) curves. Due to an MTF dependence of the detector system on the photon energy, the experimental results showed that low-Z targets produced superior MTF curves. Simulations showed 14.5% and 21.5% increases in f50 for the 7.0 and 4.5 MeV targets (A1; 60% R% CSDA), respectively, when moved from the carousel to the location of the clinical target. f50 values for the custom targets were compared to the clinical 6 MV beam and were found to be between 10.4% lower (4.5 MeV/W) and 15.5% higher (7.0 MeV/Be).
CONCLUSIONS
Integration of low-Z external targets into the treatment head of a medical linear was achieved with only minor modifications. It was shown that reasonably high resolution images on par or better than those acquired with the clinical 6 MV beam can be achieved using external low-Z targets.
Publication
Journal: International Journal of Oral and Maxillofacial Surgery
February/7/2007
Abstract
To explore degenerative mechanisms occurring in the temporomandibular joint (TMJ), a chemical model of knee joint osteoarthritis using sodium mono-iodoacetate injection was transposed to the TMJ. Twelve New Zealand rabbits were used to document the effect of this drug on the TMJ. Eight rabbits underwent bilateral iodoacetate injection in the disco-condylar compartment while 4 served as controls. Rabbits were sacrificed at 10, 20, 30 and 40 days and joints studied by histology. Severity of the damage was time dependent and the use of iodoacetate allowed the observation, within a few weeks, of every osteoarthritic stage usually described in the literature. This study showed that the TMJ has a specific response to the degenerative process. This response was characterized by (i) thickening and fibrillation of the cartilage at the periphery of the lesion, tending to reduce mechanical stress in the lesional area and (ii) chondrocyte migration under areas where subchondral bone surface was locally destroyed. The extracellular matrix containing chondrocyte clusters and prechondrocytes dived around the bony defect and proceeded below the necrotic bone to promote the eviction of bony fragments into the joint cavity, pushing them up while the thickness of chondrocyte rows increased below. This could be interpreted as a repairing attempt due to the specific potential of fibrocartilage proliferative cells.
Publication
Journal: Indian Journal of Tuberculosis
December/21/2016
Abstract
BACKGROUND
Poor prescribing practice is alleged to be one of the major factors fuelling the drug-resistant tuberculosis (DR TB) emergence. A study in Mumbai revealed the extent of inappropriate tuberculosis (TB) management practices of private practitioners and discussed that with the context of high DR TB. Kerala is rated among the well performing States in India as far as TB control is concerned with evidences for a lower level of TB transmission and DR TB. The current study was done in Kerala State to assess the prescribing practices of private sector doctors in the treatment of TB.
METHODS
Survey questionnaire to write a standard prescription for treating TB was administered to private practitioners dealing with TB, who attended continuing medical education programme on TB at two major cities in Kerala.
RESULTS
Responses from a total of 124 questionnaires were studied. None of them prescribed anti-TB regimen for less than 6 months. Only 7 (5.6%) prescribed a regimen without complete four drugs (H, R, Z, E) in the intensive phase. Out of the 81 doctors who prescribed private anti-TB regimen, 67 (82.7%) had of the opinion that not less than 80% of their patients complete the treatment for the prescribed duration.
CONCLUSIONS
The current study reports a reasonable TB management practice among the private sector doctors from a State with a low prevalence of DR TB and compliments the argument that effective treatment of TB following the principles of standards for TB care can prevent the emergence of DR TB.
Publication
Journal: Analytical and Bioanalytical Chemistry
September/9/2012
Abstract
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to map the spatial distribution of magnetic resonance imaging (MRI) contrast agents (Gd-based) in histological sections in order to explore synergies with in vivo MRI. Images from respective techniques are presented for two separate studies namely (1) convection enhanced delivery of a Gd nanocomplex (developmental therapeutic) into rat brain and (2) convection enhanced delivery, with co-infusion of Magnevist (commercial Gd contrast agent) and Carboplatin (chemotherapy drug), into pig brain. The LA technique was shown to be a powerful compliment to MRI not only in offering improved sensitivity, spatial resolution and signal quantitation but also in giving added value regarding the fate of administered agents (Gd and Pt agents). Furthermore simultaneous measurement of Fe enabled assignment of an anomalous contrast enhancement region in rat brain to haemorrhage at the infusion site.
Publication
Journal: BMC Public Health
August/31/2017
Abstract
Salt reduction is a public health priority but there are few studies testing the efficacy of plausible salt reduction programs.
A multi-faceted, community-based salt reduction program using the Communication for Behavioral Impact framework was implemented in Lithgow, Australia. Single 24-h urine samples were obtained from 419 individuals at baseline (2011) and from 572 at follow-up (2014). Information about knowledge and behaviors relating to salt was also collected.
Survey participants were on average 56 years old and 58 % female. Mean salt intake estimated from 24-h urine samples fell from 8.8 g/day (SD = 3.6 g/day) in 2011 to 8.0 (3.6) g/day in 2014 (-0.80, 95 % confidence interval -1.2 to -0.3;p < 0.001). There were significant increases in the proportion of participants that knew the recommended upper limit of salt intake (18 % vs. 29 %; p < 0.001), knew the importance of salt reduction (64 % vs. 78 %; p < 0.001) and reported changing their behaviors to reduce their salt intake by using spices (5 % vs. 28 %; p < 0.001) and avoiding eating out (21 % vs. 34 %; p < 0.001). However, the proportions that checked food labels (30 % vs. 25 %; p = 0.02) fell, as did the numbers avoiding processed foods (44 % vs. 35 %; p = 0.006). Twenty-six percent reported using salt substitute at the end of the intervention period and 90 % had heard about the program. Findings were robust to multivariable adjustment.
Implementation of this multi-faceted community-based program was associated with a ~10 % reduction in salt consumption in an Australian regional town. These findings highlight the potential of well-designed health promotion programs to compliment other population-based strategies to bring about much-needed reductions in salt consumption.
NCT02105727 .
Publication
Journal: Biochemical Society Transactions
September/11/2019
Abstract
Due to cell-cycle dysregulation, many cancer cells contain more than the normal compliment of centrosomes, a state referred to as centrosome amplification (CA). CA can drive oncogenic phenotypes and indeed can cause cancer in flies and mammals. However, cells have to actively manage CA, often by centrosome clustering, in order to divide. Thus, CA is also an Achilles' Heel of cancer cells. In recent years, there have been many important studies identifying proteins required for the management of CA and it has been demonstrated that disruption of some of these proteins can cause cancer-specific inhibition of cell growth. For certain targets therapeutically relevant interventions are being investigated, for example, small molecule inhibitors, although none are yet in clinical trials. As the field is now poised to move towards clinically relevant interventions, it is opportune to summarise the key work in targeting CA thus far, with particular emphasis on recent developments where small molecule or other strategies have been proposed. We also highlight the relatively unexplored paradigm of reversing CA, and thus its oncogenic effects, for therapeutic gain.
Publication
Journal: Journal of Neuromuscular Diseases
July/8/2019
Abstract
The recent availability and development of mutant and transgenic zebrafish strains that model human muscular dystrophies has created new research opportunities for therapeutic development. Not only do these models mimic many pathological aspects of human dystrophies, but their small size, large clutch sizes, rapid ex utero development, body transparency, and genetic tractability enable research approaches that would be inconceivable with mammalian model systems. Here we discuss the use of zebrafish models of muscular dystrophy to rapidly screen hundreds to thousands of bioactive compounds in order to identify novel therapeutic candidates that modulate pathologic phenotypes. We review the justification and rationale behind this unbiased approach, including how zebrafish screens have identified FDA-approved drugs that are candidates for treating Duchenne and limb girdle muscular dystrophies. Not only can these drugs be re-purposed for treating dystrophies in a fraction of the time and cost of new drug development, but their identification has revealed novel, unexpected directions for future therapy development. Phenotype-driven zebrafish drug screens are an important compliment to the more established mammalian, target-based approaches for rapidly developing and validating therapeutics for muscular dystrophies.
Publication
Journal: Journal of the American Society of Echocardiography
July/1/1998
Abstract
The diagnosis of scimitar syndrome is straightforward when the scimitar vein is visible on the chest radiograph; however, a diagnosis is not definitive when this vein is obscured by dextroversion, and therefore other investigative modalities are needed. These methods include pulmonary angiography, computed tomographic scan, and magnetic resonance imaging, which have know limitations, and transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE), which are particularly useful because they are noninvasive, versatile, and accurate. TEE is superior to TTE in the diagnosis of this syndrome and other forms of partial anomalous pulmonary venous return. TEE should compliment TTE whenever the latter is of poor quality or the information is incomplete. Moreover, TEE is vital in both the perioperative evaluation of the repair and the confirmation of the patency of the pulmonary venous to left atrial anastomosis. The advantages of TEE are demonstrated by this case report, and its accuracy is confirmed at surgery.
Authors
Publication
Journal: BMJ Global Health
November/13/2018
Abstract
South Africa's MomConnect mobile messaging programme, which aims to promote safe motherhood and improve pregnancy outcomes for South African women, includes a helpdesk feature which allows women registered on the system to ask maternal and child health (MCH)-related questions and to provide feedback on health services received at public health clinics. Messages sent to the helpdesk are answered by staff located at the National Department of Health. We examined event data from the MomConnect helpdesk database to identify any patterns in messages received, such as correlation of frequency or types of messages with location. We also explored what these data could tell us about the helpdesk's effectiveness in improving health service delivery at public health clinics. We found that approximately 8% of registered MomConnect users used the helpdesk, and that usage was generally proportional to the use of antenatal care (ANC) services in provinces (as indicated by number of ANC first visits and number of MomConnect registrations), except in two provinces. Language, category and key topics of helpdesk messages were correlated with provinces. Most users accessed the helpdesk to seek maternal information, and where feedback about health services was provided, there were significantly more compliments than complaints. The MomConnect helpdesk is an important resource providing expectant mothers and mothers of infants with an interactive option for accessing MCH-related information-above that included in the standard MomConnect messages-and advances achievement of the health goals of the MomConnect programme.
Publication
Journal: Environmental International
August/29/2010
Abstract
New and emerging policies that aim to set standards for protection and sustainable use of soil are likely to require identification of geographical risk/priority areas. Soil degradation can be seen as the change or disturbance in soil quality and it is therefore crucial that soil and soil quality are well understood to protect soils and to meet legislative requirements. To increase this understanding a review of the soil quality definition evaluated its development, with a formal scientific approach to assessment beginning in the 1970s, followed by a period of discussion and refinement. A number of reservations about soil quality assessment expressed in the literature are summarised. Taking concerns into account, a definition of soil quality incorporating soil's ability to meet multifunctional requirements, to provide ecosystem services, and the potential for soils to affect other environmental media is described. Assessment using this definition requires a large number of soil function dependent indicators that can be expensive, laborious, prone to error, and problematic in comparison. Findings demonstrate the need for a method that is not function dependent, but uses a number of cross-functional indicators instead. This method to systematically prioritise areas where detailed investigation is required, using a ranking based against a desired level of action, could be relatively quick, easy and cost effective. As such this has potential to fill in gaps and compliment existing monitoring programs and assist in development and implementation of current and future soil protection legislation.
Publication
Journal: Journal of Critical Care
May/26/2014
Abstract
Ventilatory management of acute respiratory distress syndrome has evolved significantly in the last few decades. The aims have shifted from optimal gas transfer without concern for iatrogenic risks to adequate gas transfer while minimizing lung injury. This change in focus, along with improved ventilator and multiorgan system management, has resulted in a significant improvement in patient outcomes. Despite this, a number of patients develop hypoxemic respiratory failure refractory to lung-protective ventilation (LPV). The intensivist then faces the dilemma of either persisting with LPV using adjuncts (neuromuscular blocking agents, prone positioning, recruitment maneuvers, inhaled nitric oxide, inhaled prostacyclin, steroids, and surfactant) or making a transition to rescue therapies such as high-frequency oscillatory ventilation (HFOV) and/or extracorporeal membrane oxygenation (ECMO) when both these modalities are at their disposal. The lack of quality evidence and potential harm reported in recent studies question the use of HFOV as a routine rescue option. Based on current literature, the role for venovenous (VV) ECMO is probably sequential as a salvage therapy to ensure ultraprotective ventilation in selected young patients with potentially reversible respiratory failure who fail LPV despite neuromuscular paralysis and prone ventilation. Given the risk profile and the economic impact, future research should identify the patients who benefit most from VV ECMO. These choices may be further influenced by the emerging novel extracorporeal carbon dioxide removal devices that can compliment LPV. Given the heterogeneity of acute respiratory distress syndrome, each of these modalities may play a role in an individual patient. Future studies comparing LPV, HFOV, and VV ECMO should not only focus on defining the patients who benefit most from each of these therapies but also consider long-term functional outcomes.
Publication
Journal: Spine Journal
November/15/2018
Abstract
BACKGROUND
Intraoperative neurophysiological monitoring (IONM) has gained rather widespread acceptance as a method to mitigate risk to the lumbar plexus during lateral lumbar interbody fusion (LLIF) surgery. The most common approach to IONM involves using only electromyography (EMG) monitoring, and the rate of postoperative deficit remains unacceptably high. Other test modalities, such as transcranial electric motor-evoked potentials (tcMEPs) and somatosensory-evoked potentials, may be more suitable for monitoring neural integrity, but they have not been widely adopted during LLIF. Recent studies have begun to examine their utility in monitoring LLIF surgery with favorable results.
OBJECTIVE
This study aimed to evaluate the efficacy of different IONM paradigms in the prevention of iatrogenic neurologic sequelae during LLIF and to specifically evaluate the utility of including tcMEPs in an IONM strategy for LLIF surgery.
METHODS
A non-randomized, retrospective analysis of 479 LLIF procedures at a single institution over a 4-year period was conducted. During the study epoch, three different IONM strategies were used for LLIF procedures: (1) surgeon-directed T-EMG monitoring ("SD-EMG"), (2) neurophysiologist-controlled T-EMG monitoring ("NC-EMG"), and (3) neurophysiologist-controlled T-EMG monitoring supplemented with MEP monitoring ("NC-MEP").
METHODS
The patient population comprised 254 men (53.5%) and 221 women (46.5%). Patient age ranged from a minimum of 21 years to a maximum of 89 years, with a mean of 56.6 years.
METHODS
Physician-documented physiological measures included manual muscle test grading of hip-flexion, hip-adduction, or knee-extension, as well as hypo- or hyperesthesia of the groin or anterolateral thigh on the surgical side. Self-reported measures included numbness or tingling in the groin or anterolateral thigh on the surgical side.
METHODS
Patient progress notes were reviewed from the postoperative period up to 12 months after surgery. The rates of postoperative sensory-motor deficit consistent with lumbar plexopathy or peripheral nerve palsy on the surgical side were compared between the three cohorts.
RESULTS
Using the dependent measure of neurologic deficit, whether motor or sensory, patients with NC-MEP monitoring had the lowest rate of immediate postoperative deficit (22.3%) compared with NC-EMG monitoring (37.1%) and SD-EMG monitoring (40.4%). This result extended to sensory deficits consistent with lumbar plexopathy (pure motor deficits being excluded); patients with NC-MEP monitoring had the lowest rate (20.5%) compared with NC-EMG monitoring (34.3%) and SD-EMG monitoring (36.9%). Additionally, evaluation of postoperative motor deficits consistent with peripheral nerve palsy (pure sensory deficits being excluded) revealed that the NC-MEP group had the lowest rate (5.7%) of motor deficit compared with the SD-EMG (17.0%) and NC-EMG (17.1%) cohorts. Finally, when assessing only those patients whose last follow-up was greater than or equal to 12 months (n=251), the rate of unresolved motor deficits was significantly lower in the NC-MEP group (0.9%) compared with NC-EMG (6.9%) and SD-EMG (11.0%). A comparison of the NC-MEP versus NC-EMG and SD-EMG groups, both independently and combined, was statistically significant (>95% confidence level) for all analyses.
CONCLUSIONS
The results of the present study indicate that preservation of tcMEPs from the adductor longus, quadriceps, and tibialis anterior muscles are of paramount importance for limiting iatrogenic sensory and motor injuries during LLIF surgery. In this regard, the inclusion of tcMEPs serves to compliment EMG and allows for the periodic, functional assessment of at-risk nerves during these procedures. Thus, tcMEPs appear to be the most effective modality for the prevention of both transient and permanent neurologic injury during LLIF surgery. We propose that the standard paradigm for protecting the nervous system during LLIF be adapted to include tcMEPs.
Publication
Journal: Addiction science & clinical practice
October/16/2017
Abstract
Buprenorphine maintenance for opioid dependence remains of limited availability among underserved populations, despite increases in US opioid misuse and overdose deaths. Low threshold primary care treatment models including the use of unobserved, "home," buprenorphine induction may simplify initiation of care and improve access. Unobserved induction and long-term treatment outcomes have not been reported recently among large, naturalistic cohorts treated in low threshold safety net primary care settings.
This prospective clinical registry cohort design estimated rates of induction-related adverse events, treatment retention, and urine opioid results for opioid dependent adults offered buprenorphine maintenance in a New York City public hospital primary care office-based practice from 2006 to 2013. This clinic relied on typical ambulatory care individual provider-patient visits, prescribed unobserved induction exclusively, saw patients no more than weekly, and did not require additional psychosocial treatment. Unobserved induction consisted of an in-person screening and diagnostic visit followed by a 1-week buprenorphine written prescription, with pamphlet, and telephone support. Primary outcomes analyzed were rates of induction-related adverse events (AE), week 1 drop-out, and long-term treatment retention. Factors associated with treatment retention were examined using a Cox proportional hazard model among inductions and all patients. Secondary outcomes included overall clinic retention, buprenorphine dosages, and urine sample results.
Of the 485 total patients in our registry, 306 were inducted, and 179 were transfers already on buprenorphine. Post-induction (n = 306), week 1 drop-out was 17%. Rates of any induction-related AE were 12%; serious adverse events, 0%; precipitated withdrawal, 3%; prolonged withdrawal, 4%. Treatment retention was a median 38 weeks (range 0-320) for inductions, compared to 110 (0-354) weeks for transfers and 57 for the entire clinic population. Older age, later years of first clinic visit (vs. 2006-2007), and baseline heroin abstinence were associated with increased treatment retention overall.
Unobserved "home" buprenorphine induction in a public sector primary care setting appeared a feasible and safe clinical practice. Post-induction treatment retention of a median 38 weeks was in line with previous naturalistic studies of real-world office-based opioid treatment. Low threshold treatment protocols, as compared to national guidelines, may compliment recently increased prescriber patient limits and expand access to buprenorphine among public sector opioid use disorder patients.
Publication
Journal: Neuroscience
November/25/2019
Abstract
The effects of aging are multifaceted including deleterious changes to the structure and function of the nervous system which often results in reduced mobility and quality of life. Turning while walking (dynamic) and in-place (stable) are ubiquitous aspects of mobility and have substantial consequences if performed poorly. Further, turning is thought to require higher cortical control compared to bouts of straight-ahead walking. This study sought to understand how relative amounts of corticospinal inhibition as measured by transcranial magnetic stimulation and the cortical silent period within the primary motor cortices are associated with various turning characteristics in neurotypical young (YA) and older adults (OA). In the current study, OA had reduced peak turn velocity and increased turn duration for both dynamic and stable turns. Further, OA demonstrated significantly reduced corticospinal inhibition within the right motor cortex. Finally, all associations between corticospinal inhibition and turning performance were specific to the right hemisphere, reflecting that those OA who maintained high levels of inhibition performed turning similar to their younger counterparts. These results compliment the right hemisphere model of aging and lateralization specification of cortically regulated temporal measures of dynamic movement. While additional investigations are required, these pilot findings provide an additional understanding as to the neural control of dynamic movements.
Publication
Journal: Journal of nuclear medicine : official publication, Society of Nuclear Medicine
March/14/2020
Abstract
The objective of this retrospective study was to determine the role of 18F-FDG PET/CT in a large cohort of 495 patients with metastatic neuroendocrine neoplasms (NENs) who were treated with peptide receptor radionuclide therapy (PRRT) with a long-term follow-up. Methods: The 495 patients were treated with 177Lu- and/or 90Y- DOTATOC/DOTATATE PRRT between 2/2002 and 7/2018. All subjects received both 68Ga-DOTATOC/TATE/NOC and 18F-FDG PET/CT prior to treatment and were followed 3-189 months. Kaplan-Meier analysis, log-rank test (Mantel-Cox), and Cox regression analysis were performed for overall survival (OS) and progression-free survival (PFS). Results: 199 patients (40.2%) presented with pancreatic NEN, 49 with CUP (cancer of unknown primary), 139 with midgut NEN, whereas the primary tumor was present in the rectum in 20, in the lung in 38, in the stomach in 8 and other locations in 42 patients. FDG-PET/CT was positive in 382 (77.2%) patients and 113 (22.8%) were FDG-negative before PRRT, while 100% were 68Ga-DOTATOC/TATE/NOC positive. For all patients, the median PFS and OS, defined from start of PRRT, were 19.6 mo and 58.7 mo, respectively. Positive FDG predicted shorter PFS (18.5 mo vs 24.1 mo; P = 0.0015) and OS (53.2 mo vs 83.1 mo; P < 0.001) than negative FDG. Amongst the pancreatic NEN, the median OS was 52.8 mo in FDG positive and 114.3 mo in FDG negative subjects (P = 0.0006). For all patients with positive 18F-FDG uptake, and a ratio of the highest SUVmax on 68Ga-SSTR PET to the most 18F-FDG-avid tumor lesions >2, the median OS was 53.0 mo, compared to 43.4 mo in those patients with a ratio <2 (P = 0.030). For patients with no 18F-FDG uptake (complete "mismatch" imaging pattern), the median OS was 108.3 mo vs 76.9 mo for SUVmax >15.0 and ≤15.0 on 68Ga-SSTR PET/CT, respectively. Conclusion: The presence of positive lesions on 18F-FDG PET is an independent prognostic factor in patients with NEN treated with PRRT. Metabolic imaging with 18F-FDG PET/CT compliments the molecular imaging aspect of 68Ga-SSTR PET/CT for the prognosis of survival after PRRT. High SSTR expression combined with negative 18F-FDG PET/CT imaging is associated with the most favorable long-term prognosis.
Publication
Journal: Frontiers in Neuroscience
December/6/2020
Abstract
Heart rate variability (HRV) offers insights into humoral, neural and neurovisceral processes in health and disorders of brain, body and behavior but has yet to be fully potentiated in the digital age. Remote measurement technologies (RMTs), such as, smartphones, wearable sensors or home-based devices, can passively capture HRV as a nested parameter of neurovisceral integration and health during everyday life, providing insights across different contexts, such as activities of daily living, therapeutic interventions and behavioral tasks, to compliment ongoing clinical care. Many RMTs measure HRV, even consumer wearables and smartphones, which can be deployed as wearable sensors or digital cameras using photoplethysmography. RMTs that measure HRV provide the opportunity to identify digital biomarkers indicative of changes in health or disease status in disorders where neurovisceral processes are compromised. RMT-based HRV therefore has potential as an adjunct digital biomarker in neurovisceral digital phenotyping that can add continuously updated, objective and relevant data to existing clinical methodologies, aiding the evolution of current "diagnose and treat" care models to a more proactive and holistic approach that pairs established markers with advances in remote digital technology.
Keywords: autonomic nervous system; digital biomarkers; heart rate variability; homeostasis; neurovisceral integration; remote measurement technologies.
Publication
Journal: PLoS ONE
January/21/2016
Abstract
Wombats are unique among marsupials in having one pair of upper incisors, and hypsodont molars for processing tough, abrasive vegetation. Of the three extant species, the most abundant, the common wombat (Vombatus ursinus), has had the least attention in terms of masticatory muscle morphology, and has never been thoroughly described. Using MRI and digital dissection to compliment traditional gross dissections, the major jaw adductor muscles, the masseter, temporalis and pterygoids, were described. The masseter and medial pterygoid muscles are greatly enlarged compared to other marsupials. This, in combination with the distinctive form and function of the dentition, most likely facilitates processing a tough, abrasive diet. The broad, flat skull and large masticatory muscles are well suited to generate a very high bite force. MRI scans allow more detail of the muscle morphology to be observed and the technique of digital dissections greatly enhances the knowledge obtained from gross dissections.
Publication
Journal: Biomacromolecules
May/14/2015
Abstract
Methicillin resistant Staphylococcus aureus (MRSA) is a highly virulent bacterium capable of inflicting severe infections. This pathogen has a long history of developing resistance to antibacterial drugs, and many phenotypes are capable of disabling the host immune response by releasing peptide and protein toxins with the capacity to lyse human polymorphonuclear neutrophils. The peptide phenol-soluble modulin α3 (PSMα3) has been identified as an important toxin released by the most virulent strains of MRSA. A library of polymer nonaparticles was synthesized by precipitation polymerization and screened for their ability to bind and neutralize this toxin. To generate high affinity, monomers were chosen to compliment the functional groups of PSMα3. Nanoparticles incorporating aromatic monomers provided a high affinity for the peptide and were effective at neutralizing its toxicity in vitro.
Publication
Journal: Clinical Otolaryngology
October/29/2017
Abstract
BACKGROUND
Deep neck space infection (DNSI) is defined as infection in the potential spaces and fascial planes of the neck. Early recognition of DNSI can be challenging due to the complex head and neck anatomy; hence, a high index of suspicion is required to prevent a delay in diagnosis and appropriate management.
OBJECTIVE
There remains a lack of consensus on the management of paediatric DNSI with many advocating a more aggressive approach with immediate surgical drainage, while others favour a more conservative approach with medical management in the first instance. The current literature on the management of paediatric DNSI is reviewed.
UNASSIGNED
A literature review performed in November 2015 searched PubMed using the terms 'deep neck space', 'infection', 'paediatric', 'pediatric', 'children', 'imaging', 'conservative', 'antibiotic' and 'surgery'. Articles not in the English language were excluded.
RESULTS
(i) Clinical presentation: Management of a compromised airway is the priority. Clinical history and examination enables the identification of the primary source of infection and presence of complications. (ii) Investigations: Laboratory and microbiological investigations should be appropriately targeted, and CT imaging is the modality utilised in most cases. The presence of specific complications may warrant other imaging modalities. (iii) Antibiotics: An evidence-based antibiotic regime is proposed. (iv) Conservative treatment: In children lacking indications for surgical intervention, a trial 48 h of intravenous antibiotics (IV Abx) should be commenced. v) Surgical intervention: Indications include signs of airway compromise, presence of complications, no clinical improvement after 48 h of IV Abx, abscess >2.2 cm on CT imaging, age <4 years and ITU admission.
CONCLUSIONS
An appreciation of head and neck anatomy is vital to understanding disease pathology and potential complications of DNSI, which may be life threatening. Both conservative and surgical approaches are viable treatment options and may compliment each other. Current evidence suggests that clinical management should be targeted towards the individual patient as factors such as age of the child may influence the balance of a conservative versus a surgical approach.
Publication
Journal: Methods in enzymology
January/22/2012
Abstract
High-resolution NMR spectroscopy has been widely used to monitor metabolism almost since the technique's development. It is now one of the principle technologies used in metabolomics, to profile the metabolite compliment of a cell, tissue, organism, or biofluid. This chapter describes how tissue extracts are prepared for NMR spectroscopy and, in particular, focuses on two approaches based on perchloric acid and methanol/chloroform extractions. This is followed by a description of key NMR experiments that can be used to profile tissue extracts, biofluids, or intact tissues. While these NMR techniques should be optimized for a particular sample set, we provide some tried and tested starting parameters for these experiments which should allow the user to acquire good quality spectra.
Publication
Journal: Journal of the History of the Neurosciences
September/13/2015
Abstract
A multitude of nonpharmacological interventions to terminate hiccup belong to the public-domain hiccup "mythology" or have been described in the medical literature as case reports. While usually effective in terminating bouts of acute hiccup, they are mostly ineffective in cases of hiccupping that have been present for an extended period. The common denominator of most of these therapeutic maneuvers (some also used to terminate paroxysmal supraventricular tachycardia) is their ability to directly or indirectly increase efferent vagal activity. Among the best known "vagal maneuvers" are the oculo-cardiac reflex (Dagnini-Aschner), the carotid sinus massage, the Valsalva maneuver, stimulation of the ear/auditory canal, ice ingestion, and induction of emesis. This short report provides an overview on hiccups and attempts to identify the lesser known personalities who pioneered its treatment by vagal maneuvers. The recent introduction of electrical vagus nerve stimulation for therapy-resistant hiccup is the ultimate compliment to these pioneers.
Publication
Journal: Ultramicroscopy
April/24/2000
Abstract
The structure of nanocrystalline anatase (TiO2) was successfully refined from electron powder diffraction data using the Rietveld technique. A polycrystalline sample (average crystal size about 70 A) was characterised by selected area electron diffraction in a conventional transmission electron microscope operated at 300 kV. Radially integrated intensities were extracted from digitised photographic films and used in the course of structure refinements by a standard program for Rietveld analysis. The structure was refined in space group I4(1)/amd (#141) with lattice parameters a = 3.7710(9) A and c = 9.430(2) A. The reliability factors of the refinement are Rwp = 5.2% and R(B) = 2.6%. The close agreement of the refined structural parameters with previous results obtained from neutron diffraction on coarse-grained powders proves the applicability of the method for characterising nanocrystalline powders. The present study shows that Rietveld analysis on electron powder data is a good compliment to the existing methods for accurate structural investigations on nanocrystalline materials and thin films.
Publication
Journal: Journal of the Optical Society of America A: Optics and Image Science, and Vision
August/27/1998
Abstract
The data presented in this paper examine the ability of observers to detect a modulation in the contrast of chromatic and luminance gratings as a function of the carrier contrast, duration, and spatial frequency. The nature of the signal underlying this ability is investigated by examining both the paradigm used to make the measurement and the effect of grating masks on performance in the tasks. The results show that observers' ability to discriminate amplitude modulation from an unmodulated carrier is dependent on carrier contrast but only up to approximately 5-8 times carrier-detection threshold. Discrimination is, however, independent of spatial frequency [10-1 cycles per degree (cpd) component-frequency range], carrier color, and, most surprisingly, stimulus duration (1000-30 ms). This set of experiments compliments data from previous papers and assimilates many of the conclusions drawn from this previous data. There is absolutely no evidence for the existence of a distortion product mediating performance under any of the current conditions, and the data seriously question whether the visual system might use such a signal even if it does exist under more extreme conditions than those used here. The evidence suggests that the visual system detects variations in both chromatic and luminance contrast by means of a mechanism operating locally upon the spatial structure of the carrier.
Publication
Journal: Journal of quality in clinical practice
January/2/1995
Abstract
This paper presents a review of the patient complaints and those who walked out prior to receiving care in the Accident and Emergency (A&E) Department of the Children's Hospital, Camperdown. The walkout rate was 1.7% (424/27,082) in 1992. Walkouts were greatest in winter when the department was busiest, peak period being between 2000 and 0200 hours. The waiting time was presented as the main reason for walking out. Most parents were prepared to wait the advertised waiting time before leaving. The presenting complaints of children who were not seen covered a spectrum of illnesses with the potential for significant morbidity. The majority, however, were triaged as non-urgent cases. Despite attempts to follow up on walkouts, the outcome for 53% of patients was unknown. Written complaints were fewer in number and tended to focus more on the quality of care (66.6%). There were few recorded compliments. With the increasing customer focus on health, greater attention needs to be given to system failures.
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