Cystic Neoplasms of the Exocrine Pancreas

Cystic neoplasms of the pancreas are rare and their diagnosis and treatment can be difficult. This report details 7 patients who had histologically proven serous cystadenoma4, mucinous cystadenoma2 and cystadeno carcinoma1. Computed tomography and sonography allowed excellent preoperative assessment but to attempt a distinction between the histological variants may be hazardous. Two tumours were only autopsy findings and 5 patients underwent laparotomy. It is confirmed that potentially malignant mucinous cystadenomas and cytadenocarcinomas should be resected whenever possible; serous cystadenomas are always benign and should therefore be resected only when the diagnosis is doubtful or if they cause symptoms

Effects of age and eccentricity on visual target detection

The aim of this study was to examine the effects of aging and target eccentricity on a visual search task comprising 30 images of everyday life projected into a hemisphere, realizing a ±90° visual field. The task performed binocularly allowed participants to freely move their eyes to scan images for an appearing target or distractor stimulus (presented at 10°; 30°, and 50° eccentricity). The distractor stimulus required no response, while the target stimulus required acknowledgment by pressing the response button. One hundred and seventeen healthy subjects (mean age = 49.63 years, SD = 17.40 years, age range 20–78 years) were studied. The results show that target detection performance decreases with age as well as with increasing eccentricity, especially for older subjects. Reaction time also increases with age and eccentricity, but in contrast to target detection, there is no interaction between age and eccentricity. Eye movement analysis showed that younger subjects exhibited a passive search strategy while older subjects exhibited an active search strategy probably as a compensation for their reduced peripheral detection performance

"Do your eyes play tricks on you?” Asking older people about visual hallucinations in a general eye clinic

Visual hallucinations are well recognized in individuals with low vision and intact cognition (Charles Bonnet syndrome) (Teunisse et al., 1996). Visual hallucinations also occur in those with early manifestations of dementia with Lewy bodies (McKeith et al., 2005) and Parkinson's disease dementia (Williams and Lees, 2005). Typically, visual hallucinations in these conditions are complex recurrent hallucinations of people and animals and frequently reported as being unpleasant (Mosimann et al., 2006). Individuals with visual hallucinations are often reluctant to disclose details of their symptoms (Menon, 2005), but may instead report non-specific visual difficulties to their family physician or optometrist, resulting in referral to an eye clinic. Failure to elicit the presence of visual hallucinations may lead to inappropriate treatment of age-related ocular comorbidity, such as early catarac

Determination of the absorption constant in the interband region by photocurrent measurements

We determined high absorption constants of crystals from photocurrent measurements within the interband absorption region (10-104cm-1). The method has been demonstrated in the interband absorption regime near 530nm in Sn2P2S6, a novel infrared sensitive photorefractive material, and in the interband absorption regime near 257nm of near stoichiometric LiTaO3. Besides the verification of older measurements with our new technique, precise absorption data for Sn2P2S6 in the wavelength range 488-514nm are presente

Visual exploration behaviour during clock reading in Alzheimer's disease

Eye movement behaviour during visual exploration of 24 patients with probable Alzheimer's disease and 24 age‐matched controls was compared in a clock reading task. Controls were found to focus exploration on distinct areas at the end of each clock hand. The sum of these two areas of highest fixation density was defined as the informative region of interest (ROI). In Alzheimer's disease patients, visual exploration was less focused, with fewer fixations inside the ROI, and the time until the first fixation was inside the ROI was significantly delayed. Changes of fixation distribution correlated significantly with the ability to read the clock correctly, but did not correlate with dementia severity. In Alzheimer's disease patients, fixations were longer and saccade amplitudes were smaller. The altered visual exploration in Alzheimer's disease might be related to parietal dysfunction or to an imbalance between a degraded occipito‐parietal and relatively preserved occipito‐temporal visual networ

Social networking sites and older users - a systematic review

Background: Social networking sites can be beneficial for senior citizens to promote social participation and to enhance intergenerational communication. Particularly for older adults with impaired mobility, social networking sites can help them to connect with family members and other active social networking users. The aim of this systematic review is to give an overview of existing scientific literature on social networking in older users. Methods: Computerized databases were searched and 105 articles were identified and screened using exclusion criteria. After exclusion of 87 articles, 18 articles were included, reviewed, classified, and the key findings were extracted. Common findings are identified and critically discussed and possible future research directions are outlined. Results: The main benefit of using social networking sites for older adults is to enter in an intergenerational communication with younger family members (children and grandchildren) that is appreciated by both sides. Identified barriers are privacy concerns, technical difficulties and the fact that current Web design does not take the needs of older users into account. Conclusions: Under the conditions that these problems are carefully addressed, social networking sites have the potential to support today's and tomorrow's communication between older and younger family member

Multi-phase postmortem CT angiography: recognizing technique-related artefacts and pitfalls

Background and purpose: Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. Material and methods: An experienced radiologist blinded to all clinical and forensic data retrospectively reviewed 49 MPMCTAs. Each angiographic phase, i.e. arterial, venous and dynamic, was analysed separately to identify phase-specific artefacts based on location and aspect. Results: Incomplete contrast filling of the cerebral venous system was the most commonly encountered artefact, followed by contrast agent layering in the lumen of the thoracic aorta. Enhancement or so-called oedematization of the digestive system mucosa was also frequently observed. Conclusion: All MPMCTA artefacts observed and described here are reproducible and easily identifiable. Knowledge about these artefacts is important to avoid misinterpreting them as pathological finding

Visual exploration in Parkinson's disease and Parkinson's disease dementia

Parkinson's disease, typically thought of as a movement disorder, is increasingly recognized as causing cognitive impairment and dementia. Eye movement abnormalities are also described, including impairment of rapid eye movements (saccades) and the fixations interspersed between them. Such movements are under the influence of cortical and subcortical networks commonly targeted by the neurodegeneration seen in Parkinson's disease and, as such, may provide a marker for cognitive decline. This study examined the error rates and visual exploration strategies of subjects with Parkinson's disease, with and without cognitive impairment, whilst performing a battery of visuo-cognitive tasks. Error rates were significantly higher in those Parkinson's disease groups with either mild cognitive impairment (P = 0.001) or dementia (P < 0.001), than in cognitively normal subjects with Parkinson's disease. When compared with cognitively normal subjects with Parkinson's disease, exploration strategy, as measured by a number of eye tracking variables, was least efficient in the dementia group but was also affected in those subjects with Parkinson's disease with mild cognitive impairment. When compared with control subjects and cognitively normal subjects with Parkinson's disease, saccade amplitudes were significantly reduced in the groups with mild cognitive impairment or dementia. Fixation duration was longer in all Parkinson's disease groups compared with healthy control subjects but was longest for cognitively impaired Parkinson's disease groups. The strongest predictor of average fixation duration was disease severity. Analysing only data from the most complex task, with the highest error rates, both cognitive impairment and disease severity contributed to a predictive model for fixation duration [F(2,76) = 12.52, P ≤ 0.001], but medication dose did not (r = 0.18, n = 78, P = 0.098, not significant). This study highlights the potential use of exploration strategy measures as a marker of cognitive decline in Parkinson's disease and reveals the efficiency by which fixations and saccades are deployed in the build-up to a cognitive response, rather than merely focusing on the outcome itself. The prolongation of fixation duration, present to a small but significant degree even in cognitively normal subjects with Parkinson's disease, suggests a disease-specific impact on the networks directing visual exploration, although the study also highlights the multi-factorial nature of changes in exploration and the significant impact of cognitive decline on efficiency of visual searc

Round-Robin evaluation of the methodology for filtration efficiency tests in different filter media against nanoparticles

The filtration of airborne nanoparticles is becoming an important issue as they are produced in large quantities from material synthesis and combustion emission. Current international standards dealing with efficiency test for filters and filter media focus on measurement of the minimum efficiency at the most penetrating particle size. The available knowledge and instruments provide a solid base for development of test methods to determine the effectiveness of filtration media against airborne nanoparticles down to single-digit nanometer range. An interlaboratory evaluation was performed under the Technical Committee 195 of European Committee for Standardization (CEN/TC195) for the development of the methodology to determine effectiveness of filtration media against airborne particles in the 3 – 500 nm range. Five different laboratories, ETH/Empa, University of Minnesota, Politecnico di Torino, Unifil and Camfil, participated in the round robin test in order to ensure the accuracy of the test method. The qualification of test rig and apparatus was performed prior of the filtration ef-ficiency measurement tests. Experimental data are presented and their validity is discussed