A demonstration of 'broken' visual space

It has long been assumed that there is a distorted mapping between real and ‘perceived’ space, based on demonstrations of systematic errors in judgements of slant, curvature, direction and separation. Here, we have applied a direct test to the notion of a coherent visual space. In an immersive virtual environment, participants judged the relative distance of two squares displayed in separate intervals. On some trials, the virtual scene expanded by a factor of four between intervals although, in line with recent results, participants did not report any noticeable change in the scene. We found that there was no consistent depth ordering of objects that can explain the distance matches participants made in this environment (e.g. A > B > D yet also A < C < D) and hence no single one-to-one mapping between participants’ perceived space and any real 3D environment. Instead, factors that affect pairwise comparisons of distances dictate participants’ performance. These data contradict, more directly than previous experiments, the idea that the visual system builds and uses a coherent 3D internal representation of a scene

Completing the Enalaprilat Excretion Pathway-Renal Handling by the Proximal Tubule

: Background: Enalapril is often used in the treatment of cardiovascular diseases. Clinical data suggest that the urinary excretion of enalaprilat, the active metabolite of enalapril, is mediated by renal transporters. We aimed to identify enalaprilat specificity for renal proximal tubular transporters. Methods: Baculovirus-transduced HEK293 cells overexpressing proximal tubular transporters were used to study enalaprilat cellular uptake. Uptake into cells overexpressing the basolateral transporters OCT2, OAT1, OAT2, or OAT3 and apical transporters OAT4, PEPT1, PEPT2, OCTN1, OCTN2, MATE1, MATE2k, and URAT1 was compared with mock-transduced control cells. Transport by renal efflux transporters MRP2, MPR4, P-gp, and BCRP was tested using a vesicular assay. Enalaprilat concentrations were measured using LC-MS/MS. Results: Uptake of enalaprilat into cells expressing OAT3 as well as OAT4 was significantly higher compared to control cells. The enalaprilat affinity for OAT3 was 640 (95% CI: 520–770) µM. For OAT4, no reliable affinity constant could be determined using concentrations up to 3 mM. No transport was observed for other transporters. Conclusion: The affinity of enalaprilat for OAT3 and OAT4 was notably low compared to other substrates. Taking this affinity and clinically relevant plasma concentrations of enalaprilat and other OAT3 substrates into account, we believe that drug–drug interactions on a transporter level do not have a therapeutic consequence and will not require dose adjustments of enalaprilat itself or other OAT3 substrates

Uterine Artery Embolization in Patients with a Large Fibroid Burden: Long-Term Clinical and MR Follow-up

Uterine artery embolization (UAE) in patients with a large fibroid burden is controversial. Anecdotal reports describe serious complications and limited clinical results. We report the long-term clinical and magnetic resonance (MR) results in a large series of women with a dominant fibroid of >10 cm and/or an uterine volume of >700 cm3. Seventy-one consecutive patients (mean age, 42.5 years; median, 40 years; range, 25–52 years) with a large fibroid burden were treated by UAE between August 2000 and April 2005. Volume reduction and infarction rate of dominant fibroid and uterus were assessed by comparing the baseline and latest follow-up MRIs. Patients were clinically followed at various time intervals after UAE with standardized questionnaires. There were no serious complications of UAE. During a mean follow-up of 48 months (median, 59 months; range, 6–106 months), 10 of 71 patients (14%) had a hysterectomy. Mean volume reduction of the fibroid and uterus was 44 and 43%. Mean infarction rate of the fibroid and overall fibroid infarction rate was 86 and 87%. In the vast majority of patients there was a substantial improvement of symptoms. Clinical results were similar in patients with a dominant fibroid >10 cm and in patients with large uterine volumes by diffuse fibroid disease. In conclusion, our results indicate that the risk of serious complications after UAE in patients with a large fibroid burden is not increased. Moreover, clinical long-term results are as good as in other patients who are treated with UAE. Therefore, a large fibroid burden should not be considered a contraindication for UAE

Modelling human visual navigation using multi-view scene reconstruction

It is often assumed that humans generate a 3D reconstruction of the environment, either in egocentric or world-based coordinates, but the steps involved are unknown. Here, we propose two reconstruction-based models, evaluated using data from two tasks in immersive virtual reality. We model the observer’s prediction of landmark location based on standard photogrammetric methods and then combine location predictions to compute likelihood maps of navigation behaviour. In one model, each scene point is treated independently in the reconstruction; in the other, the pertinent variable is the spatial relationship between pairs of points. Participants viewed a simple environment from one location, were transported (virtually) to another part of the scene and were asked to navigate back. Error distributions varied substantially with changes in scene layout; we compared these directly with the likelihood maps to quantify the success of the models. We also measured error distributions when participants manipulated the location of a landmark to match the preceding interval, providing a direct test of the landmark-location stage of the navigation models. Models such as this, which start with scenes and end with a probabilistic prediction of behaviour, are likely to be increasingly useful for understanding 3D vision

Left, right, left, right, eyes to the front! Müller-Lyer bias in grasping is not a function of hand used, hand preferred or visual hemifield, but foveation does matter

We investigated whether the control of movement of the left hand is more likely to involve the use of allocentric information than movements performed with the right hand. Previous studies (Gonzalez et al. in J Neurophys 95:3496–3501, 2006; De Grave et al. in Exp Br Res 193:421–427, 2009) have reported contradictory findings in this respect. In the present study, right-handed participants (N = 12) and left-handed participants (N = 12) made right- and left-handed grasps to foveated objects and peripheral, non-foveated objects that were located in the right or left visual hemifield and embedded within a Müller-Lyer illusion. They were also asked to judge the size of the object by matching their hand aperture to its length. Hand apertures did not show significant differences in illusory bias as a function of hand used, handedness or visual hemifield. However, the illusory effect was significantly larger for perception than for action, and for the non-foveated compared to foveated objects. No significant illusory biases were found for reach movement times. These findings are consistent with the two-visual system model that holds that the use of allocentric information is more prominent in perception than in movement control. We propose that the increased involvement of allocentric information in movements toward peripheral, non-foveated objects may be a consequence of more awkward, less automatized grasps of nonfoveated than foveated objects. The current study does not support the conjecture that the control of left-handed and right-handed grasps is predicated on different sources of information

Distant metastases of a squamous cell carcinoma of the tongue in peripheral skeletal muscles and adjacent soft tissues

A 66-year-old female patient was admitted to our department with a large tumor of the tongue measuring 10 cm in diameter. The tumor occupied nearly the entire oral cavity and showed exophytic and ulcerative areas. Histological analysis revealed a low grade squamous cell carcinoma (SCC) of the tongue. Bilateral enlarged cervical lymphatic masses were also present. The extent of the tumor infiltration was assessed by fluoro-2-deoxy-glucose-positron emission tomography (PET) scans showing an elevated activity of the tracer corresponding to the assumed cervical metastases. Additionally, pulmonary metastases were identified. Contrast enhanced computed tomography (CT) scans showed metastases in the soft tissues of the abdomen, legs and arms. Foci of distant metastases were found in the left upper anterior thoracal wall, near the intraabdominal portion of the aorta, near the right iliac crest and in both the right vastus medialis- and adductor magnus muscles. The final diagnosis was a T4N3M1(G3)(C3) SCC of the tongue with multiple distant thoracal, abdominal and intramuscular metastases. The survival expectancy was five weeks, and the patient finally deceased by cardiopulmonary complications

Grasping the changes seen in older adults when reaching for objects of varied texture.

Old age is associated with reduced mobility of the hand. To investigate age related decline when reaching-to-lift an object we used sophisticated kinematic apparatus to record reaches carried out by healthy older and younger participants. Three objects of different widths were placed at three different distances, with objects having either a high or low friction surface (i.e. rough or slippery). Older participants showed quantitative differences to their younger counterparts - movements were slower and peak speed did not scale with object distance. There were also qualitative differences with older adults showing a greater propensity to stop the hand and adjust finger position before lifting objects. The older participants particularly struggled to lift wide slippery objects, apparently due to an inability to manipulate their grasp to provide the level of precision necessary to functionally enclose the object. These data shed light on the nature of age related changes in reaching-to-grasp movements and establish a powerful technique for exploring how different product designs will impact on prehensile behavior

Changes in catastrophizing and kinesiophobia are predictive of changes in disability and pain after treatment in patients with anterior knee pain

Purpose. The purpose of the study was to investigate if changes in psychological variables are related to the outcome in pain and disability in patients with chronic anterior knee pain. Methods. A longitudinal observational study on 47 patients with chronic anterior knee pain was performed in a secondary healthcare setting. Pain was measured with the visual analogue scale and disability with the Lysholm scale. The psychological variables, such as anxiety, depression, pain coping strategies, catastrophizing and fear to movement beliefs, were studied by using self-administered questionnaires. Results. Among the pain coping strategies, only the catastrophizing subscale showed a significant reduction. Similarly, anxiety, depression and kinesiophobia were significantly reduced after treatment. Those patients who decreased the catastrophizing, kinesiophobia, anxiety and depression showed a greater improvement in pain and disability after a purely biomedical treatment. A multiple regression analysis revealed that changes in catastrophizing predicted the amount of improvement in pain severity and that changes in both catastrophizing and anxiety predicted changes in disability after treatment. Conclusion. What has been found suggests that clinical improvement in pain and disability is associated with a reduction in catastrophizing and kinesiophobia. Therefore, co-interventions to reduce catastrophizing thinking and kinesiophobia may enhance the results. Level of evidence. Prospective Cohort Study, Level I for prognosis

One year symptom severity and health-related quality of life changes among Black African patients undergoing uterine fibroid embolisation.

BACKGROUND: The main aim in the treatment of symptomatic fibroids by various modalities including uterine fibroid embolisation (UFE) is to alleviate symptoms and ultimately improve the quality of life. The efficacy of this modality of treatment in Black African women with significant fibroid burden and large uterine volumes is not clear. The main objective of the study was to examine potential changes in symptom severity among Black African patients 1 year following UFE for symptomatic uterine fibroids in a resource-constrained setting, rated using a validated questionnaire (UFS-QOL). Secondary outcomes examined were changes in quality of life and potential associations with age, parity, uterine volume and fibroid number prior to UFE. Additional interventions after UFE were also recorded. METHODS: A prospective before and after study of Black African patients undergoing UFE was undertaken. Participants underwent pelvic MR imaging prior to UFE and completed the UFS-QOL, a validated condition-specific questionnaire at baseline and at 1 year. Ninety five participants were recruited and data from 80 completing 1 year of follow up were available for analysis of changes in the symptom severity scores. RESULTS: The mean reduction in symptom severity score was 29.6 [95% CI 23.6 to 35.6, P < 0.001] and the mean improvement in HRQOL score was 35.7 [95% CI 28.4 to 42.9, P < 0.001]. A greater number of fibroids identified prior to UFE was associated with a more substantial improvement in symptom severity score (rs = 0.28, n = 80, P = 0.013) and participants of higher parity reported a greater improvement in HRQOL score (r = 0.336, P = 0.002). Major and minor surgical interventions were needed in 5 (6.3%) and 10 (12.5%) participants respectively. CONCLUSIONS: UFE is associated with clinically useful and statistically significant symptom relief in Black African patients. Symptom improvement following UFE is not compromised by a large fibroid burden and the rate of subsequent intervention is within an acceptable range. UFE is a safe alternative and efforts are needed to widen access to this non-surgical treatment modality