Anaesthesia of three young grey seals (Halichoerus grypus) for fracture repair

Three young grey seals (Halichoerus grypus) were presented separately for fracture repair to the veterinary teaching hospital of University College Dublin. The seals were premedicated with a combination of pethidine, midazolam and atropine; anaesthesia was induced with propofol via the front flipper vein and maintained with sevoflurane or isoflurane in oxygen. One of the seals did not breathe spontaneously after anaesthesia; a cardiac arrest, resulting in death, occurred after several hours of mechanical ventilation. Post-mortem examination revealed a severe lungworm infestation and parasitic pneumonia in this animal. The two other seals recovered uneventfully from anaesthesia.

Walking speed and peak plantar pressure distribution during barefoot walking in persons with diabetes

BACKGROUND

The impact of walking speed has not been evaluated as a feasible outcome measure associated with peak plantar pressure (PPP) distribution, which may result in tissue damage in persons with diabetic foot complications. The objective of this pilot study was to determine the walking speed and PPP distribution during barefoot walking in persons with diabetes. 

METHODS

 Nine individuals with diabetes and nine age-gender matched individuals without diabetes participated in this study. Each individual was marked at 10 anatomical landmarks for vibration and tactile pressure sensation tests to determine the severity of sensory deficits on the plantar surface of the dominant limb foot. A steady state walking speed, PPP, the fore and rear foot (F/R) PPP ratio and gait variables were measured during barefoot walking. 

RESULTS

 Persons with diabetes had a significantly slower walking speed than the age-gender matched group resulting in a significant reduction of PPP at the F/R foot during barefoot walking (p < 0.05). There was no significant difference in F/R foot PPP ratio in the diabetic group compared with the age-gender matched group during barefoot walking (p > 0.05). There was a significant difference between the diabetic and non-diabetic groups for cadence, step time, toe out angle and the anterior-posterior excursion (APE) for centre of force (p < 0.05). 

CONCLUSION

 Walking speed may be a potential indicator for persons with diabetes to identify PPP distribution during barefoot walking in a diabetic foot. However, the diabetic group demonstrated a more cautious walking pattern than the age-gender matched group by decreasing cadence, step length and APE, and increasing step time and toe in/out angle. People with diabetes may reduce the risk of foot ulcerations as long as they are able to prevent severe foot deformities such as callus, hammer toe or charcot foot.

Relation of synovitis to knee pain using contrast-enhanced MRIs

BACKGROUND

It has been suggested that synovitis causes joint pain. On non-contrast-enhanced MRIs synovial thickening cannot be assessed and on these images synovitis has been inconsistently associated with pain.

OBJECTIVE

To assess synovial thickening in relation to knee pain severity among subjects in the Multicenter Osteoarthritis Study (MOST) using contrast-enhanced (CE) MRI.

METHODS

MOST is a cohort study of people who have, or are at high risk of, knee osteoarthritis (OA). An unselected subset of 535 participants who volunteered underwent CE 1.5 T MRI of one knee. Synovitis was scored in six compartments and a summary score was created. Knee pain severity was assessed using the maximum item score on the Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain scale. The association between synovitis and pain severity was examined using a logistic regression model adjusting for age, sex, body mass index (BMI), MRI bone marrow lesions and effusions in the whole sample and in a subgroup without radiographic OA.

RESULTS

454 of the 535 subjects undergoing CE MRI had complete data on synovitis and WOMAC pain. Mean age was 59 years, mean BMI 30 and 48% were women. In knees with moderate pain, 80% had synovitis. For knee pain, synovitis conferred a 9.2-fold increased odds compared with those without synovitis. In knees without radiographic OA (n=329), there was also an association of synovitis with an increased prevalence of pain.

CONCLUSION

Synovitis has a strong relation with knee pain severity, an association detected more clearly with CE MRI than suggested by previous studies using non-CE MRI measures of synovitis.

Action selection: a race model for selected and non-selected actions distinguishes the contribution of premotor and prefrontal areas

Race models have been used to explain perceptual, motor and oculomotor decisions. Here we developed a race model to explain how human subjects select actions when there are no overt rewards and no external cues to specify which action to make. Critically, we were able to estimate the cumulative activity of neuronal decision-units for selected and non-selected actions. We used functional magnetic resonance imaging (fMRI) to test for regional brain activity that correlated with the predictions of this race model. Activity in the pre-SMA, cingulate motor and premotor areas correlated with prospective selection between responses according to the race model. Activity in the lateral prefrontal cortex did not correlate with the race model, even though this area was active during action selection. This activity related to the degree to which individuals switched between alternative actions. Crucially, a follow-up experiment showed that it was not present on the first trial. Taken together, these results suggest that the lateral prefrontal cortex is not the source for the generation of action. It is more likely that it is involved in switching to alternatives or monitoring previous actions. Thus, our experiment shows the power of the race model in distinguishing the contribution of different areas in the selection of action.

Major conservation policy issues for biodiversity in Oceania

Oceania is a diverse region encompassing Australia, Melanesia, Micronesia, New Zealand, and Polynesia, and it contains six of the world's 39 hotspots of diversity. It has a poor record for extinctions, particularly for birds on islands and mammals. Major causes include habitat loss and degradation, invasive species, and overexploitation. We identified six major threatening processes (habitat loss and degradation, invasive species, climate change, overexploitation, pollution, and disease) based on a comprehensive review of the literature and for each developed a set of conservation policies. Many policies reflect the urgent need to deal with the effects of burgeoning human populations (expected to increase significantly in the region) on biodiversity. There is considerable difference in resources for conservation, including people and available scientific information, which are heavily biased toward more developed countries in Oceania. Most scientific publications analyzed for four threats (habitat loss, invasive species, overexploitation, and pollution) are from developed countries: 88.6% of Web of Science publications were from Australia (53.7%), New Zealand (24.3%), and Hawaiian Islands (10.5%). Many island states have limited resources or expertise. Even countries that do (e.g., Australia, New Zealand) have ongoing and emerging significant challenges, particularly with the interactive effects of climate change. Oceania will require the implementation of effective policies for conservation if the region's poor record on extinctions is not to continue.

Met160Val TMPRSS2 gene polymorphism and early onset prostate cancer in high-risk men

5000

Background: The TMPRSS2-ERG gene fusion has been found in over 50% of prostate tumors and its role is being characterized in various clinical settings. The T-allele of the Met160Val single nucleotide polymorphism (SNP) has been found to be associated with translocation and multiple copies of the TMPRSS2-ERG fusion. This SNP needs clinical characterization in men at high risk for prostate cancer (PCA) (men with a family history [FH] of PCA and African American [AA] men) to determine the role in personalizing PCA early detection. The Prostate Cancer Risk Assessment Program (PRAP) is a prospective screening program for high risk men. PRAP has > 700 participants, and 60% are AA. Here we evaluated the Met160Val SNP (rs12329760) in the TMPRSS2 gene with respect to race, FH of PCA, and time to PCA diagnosis. Methods: Eligibility for PRAP includes men ages 35–69 years with one first degree relative with PCA, two second degree relatives with PCA on the same side of the family, any AA man regardless of FH of PCA, and men with BRCA1/2 mutations. Criteria for biopsy and biopsy approach have been reported previously. Genotyping of the Met160Val SNP was performed using the Taqman SNP Genotyping Assay (Applied Biosystems). Standard statistical methods were used to determine risk-genotype distributions. Cox models were used for time to PCA diagnosis by risk genotype. Results: Out of 700 men in PRAP, 631 were able to be genotyped for the Met160Val SNP. There was no difference in distribution of genotypes (CT/TT vs. CC) among 231 White men with familial PCA and 400 AA men in PRAP. Among 183 White men with familial PCA with > one follow-up visit, those with the CT/TT genotypes were found to have a significantly earlier time to PCA diagnosis vs. the CC genotype (p = 0.0058). In addition, the hazard ratio for PCA among high-risk White men of the CT/TT genotypes vs CC genotype was 2.55 (p = 0.022) after controlling for age and PSA. No trends were seen among AA men for time to PCA diagnosis for any of the Met160Val SNP genotypes. Conclusions: The T-allele of the Met160Val variant in the TMPRSS2 gene may be informative of time to PCA diagnosis among White men who have a FH of PCA. This genetic variant warrants further study in high-risk men with familial PCA for its role in personalizing PCA early detection.

No significant financial relationships to disclose.

Initial radiation experience evaluating early tolerance and toxicities in patients undergoing accelerated partial breast irradiation using the Contura™ multi-lumen balloon (MLB) breast brachytherapy catheter

Abstract #5138

Purpose: We reviewed our institution's experience treating patients with the Contura™ Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) to determine short-term treatment efficacy, cosmesis, toxicity and additional dosimetric capabilities of the new APBI device.&#x2028; Materials and Methods: From 05/07 to 05/08, 41 patients, from a single surgeon (PI), were treated with breast conserving therapy (BCT) received adjuvant radiation using the Contura™ catheter (34 Gy in 3.4 Gy fractions). 13/41 patients (31.7%) had stage 0 disease, 21 (51.2%) had stage I and 7 (17.1%) had stage II breast cancer.&#x2028; For each patient, the dosimetric plan was customized using the 5 high dose rate brachytherapy channels of the Contura™ catheter by selecting from 45 different dwell positions (9 per catheter).&#x2028; Results: Median, minimum skin spacing was 10 mm (range 2 to 17). The median maximum skin dose (% of prescribed dose [PD]) was 99.7 (57.1 to 124.1). Eight patients were able to be treated with a skin spacing of 5 mm or less, 2 had spacing of 2 mm. The median maximum rib dose was 102.6 % of PD (10.0 to 187.7), median percentage of the planning target volume (PTV) receiving 95% of the PD was 98.8 (79.4 to 107.4) and the median volume receiving 200% of the PD was 5.7 cc (range 1.3 to 9.9).&#x2028; The percentage of patients with excellent/good cosmetic results at 3 and 6 months was 94% (16 evaluable patients) and 89% (9 evaluable patients), respectively. One patient developed skin ulceration after receiving chemotherapy. Patient tolerance was assessed on a scale 0-10 (0=no pain, 10 = requiring narcotic analgesics). In 37/38 (97.3%) patients, pain was graded ≤ 3 at the time of catheter insertion. Four transient breast infections (11%) developed and one transient symptomatic seroma developed (3%).&#x2028; Conclusion: Adjuvant APBI using the Contura™ MLB catheter exhibited similar toxicities to standard single-lumen balloon brachytherapy with absolute improvements in dosimetric capabilities (i.e., reduced skin dose, improved PTV coverage and normal tissue avoidance). With multiple lumen planning, more conformal dosimtery was achieved as compared to single-lumen balloon treatment. This allowed the treatment of 8 patients with skin spacing of 5 mm or less, normally not achievable with single-lumen balloon treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5138.

Parkinson's disease and dopaminergic therapy--differential effects on movement, reward and cognition

Cognitive deficits are very common in Parkinson's disease particularly for ‘executive functions’ associated with frontal cortico-striatal networks. Previous work has identified deficits in tasks that require attentional control like task-switching, and reward-based tasks like gambling or reversal learning. However, there is a complex relationship between the specific cognitive problems faced by an individual patient, their stage of disease and dopaminergic treatment. We used a bimodality continuous performance task during fMRI to examine how patients with Parkinson's disease represent the prospect of reward and switch between competing task rules accordingly. The task-switch was not separately cued but was based on the implicit reward relevance of spatial and verbal dimensions of successive compound stimuli. Nineteen patients were studied in relative ‘on’ and ‘off’ states, induced by dopaminergic medication withdrawal (Hoehn and Yahr stages 1–4). Patients were able to successfully complete the task and establish a bias to one or other dimension in order to gain reward. However the lateral prefrontal cortex and caudate nucleus showed a non-linear U-shape relationship between motor disease severity and regional brain activation. Dopaminergic treatment led to a shift in this U-shape function, supporting the hypothesis of differential neurodegeneration in separate motor and cognitive cortico–striato–thalamo–cortical circuits. In addition, anterior cingulate activation associated with reward expectation declined with more severe disease, whereas activation following actual rewards increased with more severe disease. This may facilitate a change in goal-directed behaviours from deferred predicted rewards to immediate actual rewards, particularly when on dopaminergic treatment. We discuss the implications for investigation and optimal treatment of this common condition at different stages of disease.

Rule-selection and action-selection have a shared neuroanatomical basis in the human prefrontal and parietal cortex

The human capacity for voluntary action is one of the major contributors to our success as a species. In addition to choosing actions themselves, we can also voluntarily choose behavioral codes or sets of rules that can guide future responses to events. Such rules have been proposed to be superordinate to actions in a cognitive hierarchy and mediated by distinct brain regions. We used event-related functional magnetic resonance imaging to study novel tasks of rule-based and voluntary action. We show that the voluntary selection of rules to govern future responses to events is associated with activation of similar regions of prefrontal and parietal cortex as the voluntary selection of an action itself. The results are discussed in terms of hierarchical models and the adaptive coding potential of prefrontal neurons and their contribution to a global workspace for nonautomatic tasks. These tasks include the choices we make about our behavior.

Determinants of health related quality of life and health state utility in patients with age related macular degeneration: the association of contrast sensitivity and visual acuity

BACKGROUND

There has been increasing interest in the use of measures of health related quality of life (HRQoL) and health state utility values in Age Related Macular Degeneration (ARMD). Visual acuity has been found to be an important determinant of such measures in previous studies. More recently, another measure of visual impairment, contrast sensitivity has received considerable attention. We designed a study to examine whether the contribution of contrast sensitivity in explaining HRQoL and health utilities over and above that of visual acuity.

METHODS

209 patients with unilateral or bilateral ARMD were recruited into a cross-sectional study of patients from a large teaching hospital. Patients underwent visual tests (near and distant visual acuity, contrast sensitivity) and completed a vision function questionnaire, the VF-14, HUI3, and time trade-off.

RESULTS

Using multivariate regression analysis, the study revealed that contrast sensitivity remained a statistically significant predictor of all outcome measures even when visual acuity was included. This result was supported by the correlation coefficients between measures.

CONCLUSIONS

The measurement of contrast sensitivity appears to be better related to a person's HRQoL and health utility. Future studies should consider incorporating contrast sensitivity in addition to visual acuity. Studies, in particular economic evaluations, may underestimate the effect of treatment unless contrast sensitivity is considered.