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1.
Adv Health Sci Educ Theory Pract ; 28(4): 1053-1077, 2023 10.
Article in English | MEDLINE | ID: mdl-36662334

ABSTRACT

In pursuing assessment excellence, clinician-educators who design and implement assessment are pivotal. The influence of their assessment practice in university-run licensure exams on student learning has direct implications for future patient care. While teaching practice has been shown to parallel conceptions of teaching, we know too little about conceptions of assessment in medical education to know if this is the case for assessment practice and conceptions of assessment. To explore clinician-educators' conceptions of assessment, a phenomenographic study was undertaken. Phenomenography explores conceptions, the qualitatively different ways of understanding a phenomenon. Data analysis identifies a range of hierarchically inclusive categories of understanding, from simple to more complex, and the dimensions that distinguish each category or conception. Thirty-one clerkship convenors in three diverse Southern settings were interviewed in three cycles of iterative data collection and analysis. Four conceptions of assessment were identified: passive operator, awakening enquirer, active owner and scholarly assessor. Six dimensions were elucidated to describe and distinguish each conception: purpose of assessment; temporal perspective; role and responsibility; accountability; reflexivity and emotional valence. Additionally, three characteristics that appeared to track the progressive nature of the conceptions were identified: professional identity, assessment literacy and self-efficacy. These conceptions encompass and extend previously described conceptions across different educational levels, disciplines and contexts, suggesting applicability to other settings. There is some evidence of a relationship between conceptions and practice, suggesting, together with the hierarchical nature of these conceptions, that targeting conceptions during faculty development may be an effective approach to enhance assessment practice.


Subject(s)
Education, Medical , Humans , Learning , Faculty , Students , Educational Status
2.
Conserv Physiol ; 9(1): coab017, 2021.
Article in English | MEDLINE | ID: mdl-33959285

ABSTRACT

Many sharks and other marine taxa use natal areas to maximize survival of young, meaning such areas are often attributed conservation value. The use of natal areas is often linked to predator avoidance or food resources. However, energetic constraints that may influence dispersal of young and their use of natal areas are poorly understood. We combined swim-tunnel respirometry, calorimetry, lipid class analysis and a bioenergetics model to investigate how energy demands influence dispersal of young in a globally distributed shark. The school shark (a.k.a. soupfin, tope), Galeorhinus galeus, is Critically Endangered due to overfishing and is one of many sharks that use protected natal areas in Australia. Energy storage in neonate pups was limited by small livers, low overall lipid content and low levels of energy storage lipids (e.g. triacylglycerols) relative to adults, with energy stores sufficient to sustain routine demands for 1.3-4 days (mean ± SD: 2.4 ± 0.8 days). High levels of growth-associated structural lipids (e.g. phospholipids) and high energetic cost of growth suggested large investment in growth during residency in natal areas. Rapid growth (~40% in length) between birth in summer and dispersal in late autumn-winter likely increased survival by reducing predation and improving foraging ability. Delaying dispersal may allow prioritization of growth and may also provide energy savings through improved swimming efficiency and cooler ambient temperatures (daily ration was predicted to fall by around a third in winter). Neonate school sharks are therefore ill-equipped for large-scale dispersal and neonates recorded in the northwest of their Australian distribution are likely born locally, not at known south-eastern pupping areas. This suggests the existence of previously unrecorded school shark pupping areas. Integrated bioenergetic approaches as applied here may help to understand dispersal from natal areas in other taxa, such as teleost fishes, elasmobranchs and invertebrates.

3.
Gait Posture ; 80: 391-396, 2020 07.
Article in English | MEDLINE | ID: mdl-32650227

ABSTRACT

BACKGROUND: Achondroplasia is characterised by a shorter appendicular limb to torso ratio, compared to age matched individuals of average stature (controls). Despite the well documented shorter leg length of individuals with compared to controls, there are few complete descriptions of gait kinematics reported for the population. AIM: The aim of this study was to report the spatio-temporal and kinematic characteristics of self-selected walking (SSW) in a group with Achondroplasia (N = 10) and age matched group without Achondroplasia (controls, N = 17). METHOD: Whole body 3D analysis of both groups was conducted using a 14 camera VICON system. Spatio-temporal and kinematic variables were determined through a Plug-in-Gait model. SSW was obtained from an average of three trials equating to a total of ∼120 m walking. RESULTS: The group with Achondroplasia were 23 % slower (P < 0.001), had a 29 % shorter stride length (P < 0.001) and a 13 % higher stride frequency (P < 0.001) compared to controls. There were no differences in time normalised temporal measures of left toe off (P = 0.365), right heel contact (P = 0.442) or the duration of double support (P = 0.588) between groups. A number of discrete joint kinematic differences existed between groups, resulting in the group with Achondroplasia having more 'flexed' lower limbs than controls throughout the gait cycle. CONCLUSION: Differences in absolute spatio-temporal variables between groups is likely due to the shorter leg length of the group with Achondroplasia, while their more flexed position of the lower limbs may facilitate toe-clearance during the swing phase.


Subject(s)
Achondroplasia/physiopathology , Gait Analysis , Walking , Adolescent , Adult , Biomechanical Phenomena , Case-Control Studies , Female , Heel , Humans , Lower Extremity , Male , Range of Motion, Articular , Spatio-Temporal Analysis , Toes , Young Adult
4.
Ecol Appl ; 29(6): e01947, 2019 09.
Article in English | MEDLINE | ID: mdl-31183944

ABSTRACT

Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.


Subject(s)
Ecology , Ecosystem , Animals , Sample Size , Telemetry
5.
Gait Posture ; 68: 150-154, 2019 02.
Article in English | MEDLINE | ID: mdl-30476692

ABSTRACT

BACKGROUND: Achondroplasia is characterised by a shorter appendicular limb-to-torso ratio, compared to age matched individuals of average stature (controls). Previous work shows gait kinematics of individuals with Achondroplasia differing to controls, but no global quantification of gait has been made in adults with Achondroplasia. AIM: The aim of this study was to quantify gait differences between a group of adult males with Achondroplasia and controls during self-selected walking (SSW) using the Gait Profile Score (GPS). DESIGN: Whole body motion analysis of 10 adults with Achondroplasia (22 ± 3 yrs) who had not undergone leg lengthening and 17 adult controls (22 ± 2 yrs) was undertaken using a 14 camera VICON system (100 Hz). For each group, fifteen root mean squared Gait Variable Scores (GVS, units °) were computed from lower limb kinematic data and then summed to calculate GPS (°). RESULTS: The group with Achondroplasia had higher GVSs than controls in 10 of the 15 measures (P < 0.05) with the largest differences found in ankle plantar/dorsiflexion (P < 0.001), knee flexion/extension (P < 0.001), and hip internal/external rotation (P < 0.001). The GPS value of the group with Achondroplasia was 64% higher than controls (11.4° (2.0) v 4.1° (1.8), P < 0.001). CONCLUSION: Gait is quantitatively different in adults with Achondroplasia compared to controls. The differences in GPS between groups are due to differences in joint kinematics, which are possibly manifested by maintaining toe-clearance during swing. Gait models derived from the anatomy of individuals with Achondroplasia may improve these data.


Subject(s)
Achondroplasia/physiopathology , Gait/physiology , Lower Extremity/physiopathology , Walking/physiology , Adolescent , Adult , Biomechanical Phenomena , Female , Humans , Male , Torso/physiopathology , Young Adult
6.
Proc Natl Acad Sci U S A ; 115(12): 3072-3077, 2018 03 20.
Article in English | MEDLINE | ID: mdl-29483242

ABSTRACT

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.


Subject(s)
Animal Migration , Databases, Factual , Oceans and Seas , Vertebrates , Animals , Ecosystem
7.
Eur J Nutr Food Saf ; 8(4): 215-224, 2018.
Article in English | MEDLINE | ID: mdl-33313363

ABSTRACT

AIMS: This study was conducted to detect the presence of cyanide in popular fruit and vegetable smoothies and juices marketed as raw and natural. STUDY DESIGN: Eleven (11) popular varieties of drinks were analyzed for total cyanide (TCN). Drinks contained raw vegetables and fruits, flax seeds, whole apples with seeds, raw almond milk, and pasteurized almond milk as ingredients. PLACE AND STUDY DURATION: Samples were collected from health food eateries located within Las Vegas, Nevada (USA) during the summer of 2017. METHODOLOGY: Fifty milliliters (mL) of a homogenized smoothie and juice drink and 1 gram of flax seeds were subjected to the above-referenced methods for sample preparation per USEPA Methods 9012B (digestion) followed by USEPA method 9014 (colorimetry). RESULTS: The highest TCN was detected in drinks containing raw flax seed followed by unpasteurized raw almond milk, then fresh whole apple juice. No TCN was observed in drinks that contained none of the above mentioned items (e.g. flax seed, raw almond milk) or those utilizing pasteurized ingredients. CONCLUSION: This study observed that TCN is present in smoothies and juices containing raw flax seeds, fresh whole apples, and/or unpasteurized almond milk. Concentrations were detected as high as 341 µg L-1 in commercially available smoothies containing vegetables, raw flax seeds, almond milk and fruits. Smoothies with vegetables, fruits, unpasteurized almond milk, and no flax seeds contained 41 ug L-1 TCN, while similar smoothies with pasteurized almond milk contained negligible to 9.6 ug L-1 CN-. Unpasteurized almond milk and raw flax seeds were the major sources of TCN in drinks. With the increased demand for raw and natural foods, there is a potential sublethal exposure of TCN by consumers.

8.
Mar Pollut Bull ; 124(2): 573-586, 2017 Nov 30.
Article in English | MEDLINE | ID: mdl-28314615

ABSTRACT

Marine ecosystems are subject to anthropogenic change at global, regional and local scales. Global drivers interact with regional- and local-scale impacts of both a chronic and acute nature. Natural fluctuations and those driven by climate change need to be understood to diagnose local- and regional-scale impacts, and to inform assessments of recovery. Three case studies are used to illustrate the need for long-term studies: (i) separation of the influence of fishing pressure from climate change on bottom fish in the English Channel; (ii) recovery of rocky shore assemblages from the Torrey Canyon oil spill in the southwest of England; (iii) interaction of climate change and chronic Tributyltin pollution affecting recovery of rocky shore populations following the Torrey Canyon oil spill. We emphasize that "baselines" or "reference states" are better viewed as envelopes that are dependent on the time window of observation. Recommendations are made for adaptive management in a rapidly changing world.


Subject(s)
Climate Change , Fisheries , Petroleum Pollution , Water Pollution , Animals , Ecosystem , Ecotoxicology/methods , England , Environment , Fishes , Marine Biology/methods , Trialkyltin Compounds/toxicity , Water Pollutants, Chemical/toxicity
9.
Emerg Med J ; 33(7): 482-8, 2016 Jul.
Article in English | MEDLINE | ID: mdl-26949969

ABSTRACT

BACKGROUND: Thrombolysis can significantly reduce the burden of stroke but the time window for safe and effective treatment is short. In patients travelling to hospital via ambulance, the sending of a 'prealert' message can significantly improve the timeliness of treatment. OBJECTIVE: Examine the prevalence of hospital prealerting, the extent to which prealert protocols are followed and what factors influence emergency medical services (EMS) staff's decision to send a prealert. METHODS: Cohort study of patients admitted to two acute stroke units in West Midlands (UK) hospitals using linked data from hospital and EMS records. A logistic regression model examined the association between prealert eligibility and whether a prealert message was sent. In semistructured interviews, EMS staff were asked about their experiences of patients with suspected stroke. RESULTS: Of the 539 patients eligible for this study, 271 (51%) were recruited. Of these, only 79 (29%) were eligible for prealerting according to criteria set out in local protocols but 143 (53%) were prealerted. Increasing number of Face, Arm, Speech Test symptoms (1 symptom, OR 6.14, 95% CI 2.06 to 18.30, p=0.001; 2 symptoms, OR 31.36, 95% CI 9.91 to 99.24, p<0.001; 3 symptoms, OR 75.84, 95% CI 24.68 to 233.03, p<0.001) and EMS contact within 5 h of symptom onset (OR 2.99, 95% CI 1.37 to 6.50 p=0.006) were key predictors of prealerting but eligibility for prealert as a whole was not (OR 1.92, 95% CI 0.85 to 4.34 p=0.12). In qualitative interviews, EMS staff displayed varying understanding of prealert protocols and described frustration when their interpretation of the prealert criteria was not shared by ED staff. CONCLUSIONS: Up to half of the patients presenting with suspected stroke in this study were prealerted by EMS staff, regardless of eligibility, resulting in disagreements with ED staff during handover. Aligning the expectations of EMS and ED staff, perhaps through simplified prealert protocols, could be considered to facilitate more appropriate use of hospital prealerting in acute stroke.


Subject(s)
Emergency Medical Services/statistics & numerical data , Stroke/therapy , Aged , Emergency Medical Service Communication Systems , England/epidemiology , Female , Humans , Interviews as Topic , Male , Prevalence , Retrospective Studies , Stroke/epidemiology , Thrombolytic Therapy , Time Factors , Transportation of Patients , Treatment Outcome
10.
Oncogenesis ; 5: e199, 2016 Feb 22.
Article in English | MEDLINE | ID: mdl-26900951

ABSTRACT

Sarcomas represent a complex group of malignant neoplasms of mesenchymal origin and their heterogeneity poses a serious diagnostic and therapeutic challenge. There is therefore a need to elucidate the molecular mechanisms underpinning the pathogenesis of the more than 70 distinguishable sarcoma subtypes. The transcription factor TBX3, a critical developmental regulator, is overexpressed in several cancers of epithelial origin where it contributes to tumorigenesis by different molecular mechanisms. However, the status and role of TBX3 in sarcomas have not been reported. Here we show that a diverse subset of soft tissue and bone sarcoma cell lines and patient-derived sarcoma tissues express high levels of TBX3. We further explore the significance of this overexpression using a small interferring RNA approach and demonstrate that TBX3 promotes the migratory ability of chondrosarcoma, rhabdomyosarcoma and liposarcoma cells but inhibits fibrosarcoma cell migration. This suggested that TBX3 may play a key role in the development of different sarcoma subtypes by functioning as either an oncoprotein or as a brake to prevent tumour progression. To further explore this, TBX3 knockdown and overexpression cell culture models were established using chondrosarcoma and fibrosarcoma cells as representatives of each scenario, and the resulting cells were characterized with regard to key features of tumorigenesis. Results from in vitro and in vivo assays reveal that, while TBX3 promotes substrate-dependent and -independent cell proliferation, migration and tumour formation in chondrosarcoma cells, it discourages fibrosarcoma formation. Our findings provide novel evidence linking TBX3 to cancers of mesenchymal origin. Furthermore, we show that TBX3 may be a biomarker for the diagnosis of histologically dynamic sarcoma subtypes and that it impacts directly on their oncogenic phenotype. Indeed, we reveal that TBX3 may exhibit oncogene or tumour suppressor activity in sarcomas, which suggests that its role in cancer progression may rely on cellular context.

11.
J Fish Biol ; 87(6): 1265-70, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26709207
12.
J Fish Biol ; 87(6): 1313-21, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26511427

ABSTRACT

A large, pregnant, female bull shark Carcharhinus leucas was tracked migrating from Seychelles across open ocean to south-east Madagascar, c. 2000 km away, and back again. In Madagascar, the shark spent a prolonged period shallower than 5 m, consistent with entering estuarine habitat to pup, and upon return to Seychelles the shark was slender and no longer gravid. This represents an unprecedented return migration across the open ocean for a C. leucas and highlights the need for international collaboration to manage the regional C. leucas population sustainably.


Subject(s)
Animal Migration , Sharks/physiology , Animals , Ecosystem , Female , Madagascar , Oceans and Seas
13.
Genome Announc ; 3(1)2015 Jan 22.
Article in English | MEDLINE | ID: mdl-25614562

ABSTRACT

We report the genome sequence of Anaeromyxobacter sp. Fw109-5, isolated from nitrate- and uranium-contaminated subsurface sediment of the Oak Ridge Integrated Field-Scale Subsurface Research Challenge (IFC) site, Oak Ridge Reservation, TN. The bacterium's genome sequence will elucidate its physiological potential in subsurface sediments undergoing in situ uranium bioremediation and natural attenuation.

14.
Oncogene ; 33(5): 619-31, 2014 Jan 30.
Article in English | MEDLINE | ID: mdl-23334330

ABSTRACT

Overexpression of the receptor tyrosine kinase ERBB2 (also known as HER2) occurs in around 15% of breast cancers and is driven by amplification of the ERBB2 gene. ERBB2 amplification is a marker of poor prognosis, and although anti-ERBB2-targeted therapies have shown significant clinical benefit, de novo and acquired resistance remains an important problem. Genomic profiling has demonstrated that ERBB2+ve breast cancers are distinguished from ER+ve and 'triple-negative' breast cancers by harbouring not only the ERBB2 amplification on 17q12, but also a number of co-amplified genes on 17q12 and amplification events on other chromosomes. Some of these genes may have important roles in influencing clinical outcome, and could represent genetic dependencies in ERBB2+ve cancers and therefore potential therapeutic targets. Here, we describe an integrated genomic, gene expression and functional analysis to determine whether the genes present within amplicons are critical for the survival of ERBB2+ve breast tumour cells. We show that only a fraction of the ERBB2-amplified breast tumour lines are truly addicted to the ERBB2 oncogene at the mRNA level and display a heterogeneous set of additional genetic dependencies. These include an addiction to the transcription factor gene TFAP2C when it is amplified and overexpressed, suggesting that TFAP2C represents a genetic dependency in some ERBB2+ve breast cancer cells.


Subject(s)
Breast Neoplasms/genetics , Gene Amplification/genetics , Receptor, ErbB-2/genetics , Receptor, ErbB-2/metabolism , Transcription Factor AP-2/metabolism , Breast Neoplasms/metabolism , Cell Line, Tumor , Female , Gene Expression Profiling , Humans , MCF-7 Cells , RNA Interference , RNA, Small Interfering , Receptor, ErbB-2/biosynthesis , Transcription Factor AP-2/biosynthesis
15.
J Forensic Leg Med ; 20(5): 402-3, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23756506

ABSTRACT

Peer review in forensic pathology has been a long time in evolution but may provide a very useful mechanism to check for, and to correct, errors, in addition to establishing an important educative vehicle for pathologists. A process is reported that has been established at our institution that involves both informal peer review in the mortuary and formal auditing of a set number of cases. Every autopsy case is discussed at a daily meeting of pathologists before a provisional cause of death is released. In addition, one in ten cases including all homicides, deaths in custody, suspicious and paediatric cases, and randomly selected additional cases undergo formal auditing by a second pathologist. Finally, administrative staff check the completed report. This formalized process, in a jurisdiction where autopsies are usually performed by only one pathologist, has been extremely useful in standardizing autopsy reports and in enabling pathologists to discuss cases and associated issues on a regular basis.


Subject(s)
Forensic Pathology/standards , Peer Review/methods , Australia , Autopsy/standards , Humans , Medical Audit
16.
Sci Rep ; 3: 1471, 2013.
Article in English | MEDLINE | ID: mdl-23503585

ABSTRACT

Quantifying the energy requirements of animals in nature is critical for understanding physiological, behavioural, and ecosystem ecology; however, for difficult-to-study species such as large sharks, prey intake rates are largely unknown. Here, we use metabolic rates derived from swimming speed estimates to suggest that feeding requirements of the world's largest predatory fish, the white shark (Carcharodon carcharias), are several times higher than previously proposed. Further, our estimates of feeding frequency identify a clear benefit in seasonal selection of pinniped colonies - a white shark foraging strategy seen across much of their range.


Subject(s)
Feeding Behavior , Sharks/physiology , Animals
17.
J Fish Biol ; 82(2): 367-89, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23398057

ABSTRACT

Ten years have passed since the last synopsis of whale shark Rhincodon typus biogeography. While a recent review of the species' biology and ecology summarized the vast data collected since then, it is clear that information on population geographic connectivity, migration and demography of R. typus is still limited and scattered. Understanding R. typus migratory behaviour is central to its conservation management considering the genetic evidence suggesting local aggregations are connected at the generational scale over entire ocean basins. By collating available data on sightings, tracked movements and distribution information, this review provides evidence for the hypothesis of broad-scale connectivity among populations, and generates a model describing how the world's R. typus are part of a single, global meta-population. Rhincodon typus occurrence timings and distribution patterns make possible a connection between several aggregation sites in the Indian Ocean. The present conceptual model and validating data lend support to the hypothesis that R. typus are able to move among the three largest ocean basins with a minimum total travelling time of around 2-4 years. The model provides a worldwide perspective of possible R. typus migration routes, and suggests a modified focus for additional research to test its predictions. The framework can be used to trim the hypotheses for R. typus movements and aggregation timings, thereby isolating possible mating and breeding areas that are currently unknown. This will assist endeavours to predict the longer-term response of the species to ocean warming and changing patterns of human-induced mortality.


Subject(s)
Ecosystem , Sharks/physiology , Animal Migration , Animals , Conservation of Natural Resources , Demography , Models, Biological
18.
J Fish Biol ; 82(1): 96-110, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23331140

ABSTRACT

The use of archival depth telemetry as a means of remotely assessing the reproductive rates of free-ranging fishes is explored. This is achieved by electronically tracking the vertical movements of individual female small spotted catsharks Scyliorhinus canicula in the natural environment, whilst simultaneously evaluating the temporal and vertical distributions of egg-laying in this species. Distinctive patterns of short-term (0·3-3·7 h), shallow-water activity are documented in the time-depth profiles of female S. canicula that occur at an appropriate depth (1·0-2·3 m) and periodicity (every 10-12 days) to represent egg-laying behaviour. Putative egg-laying behaviour was exhibited simultaneously by two individually tracked female S. canicula during late-spring and early-summer. The results highlight that, provided species behaviour is suitable and complementary methods such as previous data, laboratory experiments and field surveys can be used to validate the patterns observed, archival depth telemetry offers an unobtrusive means by which egg production and egg-laying behaviour of free-living fishes can be estimated. As precise information regarding life-history parameters is difficult to obtain for free-ranging fish species, this technique could be used to improve the parameterization of species demographic models that are relevant to the management of wild fish populations.


Subject(s)
Oviposition/physiology , Sharks/physiology , Telemetry/veterinary , Animals , Female , Periodicity , Sexual Behavior, Animal/physiology , Time Factors
19.
J Forensic Sci ; 58(1): 90-100, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22994980

ABSTRACT

The stability of two benzisoxazole antipsychotics was determined in vitro in decomposing porcine blood inoculated with bacteria, utilizing a high-performance liquid chromatography with ultraviolet and fluorescence detection method for drug quantitation. Stability experiments for risperidone and paliperidone were conducted at 7, 20 and 37°C for 4 days using sterile and bacterially inoculated porcine blood. The drugs were stable in sterile blood at each temperature and in inoculated blood at 7°C, but degraded significantly in inoculated blood at 20 and 37°C. Complete loss occurred within 2 days when incubated at 37°C. The benzisoxazole-cleaved degradation products for both drugs were identified as 2-hydroxybenzoyl-risperidone and 2-hydroxybenzoyl-paliperidone utilizing liquid chromatography quadrupole-time-of-flight mass spectrometry and accurate mass measurements. The degradation products have been found in postmortem case studies, including one case where risperidone and paliperidone were not detected, indicating complete conversion can occur in situ.


Subject(s)
Antipsychotic Agents/blood , Gram-Positive Bacteria/metabolism , Isoxazoles/blood , Postmortem Changes , Pyrimidines/blood , Risperidone/blood , Animals , Chromatography, High Pressure Liquid/methods , Drug Stability , Forensic Toxicology , Paliperidone Palmitate , Risperidone/analogs & derivatives , Specimen Handling , Spectrometry, Mass, Electrospray Ionization , Swine , Temperature
20.
Br J Pharmacol ; 168(1): 200-11, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22913645

ABSTRACT

BACKGROUND AND PURPOSE: For antibody therapies against receptor targets, in vivo outcomes can be difficult to predict because of target-mediated clearance or antigen 'sink' effects. The purpose of this work was to engineer an antibody to the GM-CSF receptor α (GM-CSFRα) with pharmacological properties optimized for chronic, s.c. treatment of rheumatoid arthritis (RA) patients. EXPERIMENTAL APPROACH: We used an in silico model of receptor occupancy to guide the target affinity and a combinatorial phage display approach for affinity maturation. Mechanism of action and internalization assays were performed on the optimized antibody in vitro before refining the modelling predictions of the eventual dosing in man. Finally, in vivo pharmacology studies in cynomolgus monkeys were carried out to inform the predictions and support future clinical development. KEY RESULTS: Antibody potency was improved 8600-fold, and the target affinity was reached. The refined model predicted pharmacodynamic effects at doses as low as 1 mg kg(-1) and a study in cynomolgus monkeys confirmed in vivo efficacy at 1 mg kg(-1) dosing. CONCLUSIONS AND IMPLICATIONS: This rational approach to antibody drug discovery enabled the isolation of a potent molecule compatible with chronic, s.c. self-administration by RA patients. We believe this general approach enables the development of optimal biopharmaceuticals.


Subject(s)
Antibodies/therapeutic use , Arthritis, Rheumatoid/drug therapy , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/immunology , Animals , Arthritis, Rheumatoid/immunology , Cell Surface Display Techniques , Female , Humans , Immunoglobulin G/metabolism , Inhibitory Concentration 50 , Macaca fascicularis , Male , Models, Biological , Protein Binding , Protein Engineering , Recombinant Proteins
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