An evaluation of multiple‐choice test images for comprehension assessment in aphasia

Background: Using images in multiple‐choice formats for comprehension testing in aphasia is common. It is generally assumed that persons being assessed perceive the content of the images represented in such tasks. However, specific visual characteristics of individual images may influence visual attention, which may influence accuracy in the selection of a correct target image corresponding to a verbal stimulus. The validity of test responses may be confounded by (1) physical stimulus features, such as size, and (2) semantic content conveyed by images, such as image familiarity.

Aims: The first aim was to develop a rating instrument to assess visual stimulus properties and semantic content conveyance in multiple‐choice images, based on an extensive review of empirical literature and validated by experts in graphic design. The second aim was to study the degree of relationship between viewers' subjective ratings of images selected from published aphasia batteries, using the rating instrument, and eye movement measures recorded as independent viewers looked at the same images. The third aim was to compare the viewers' actual eye movement indices of disproportionate visual attention to an ideal value of evenly proportionate visual attention for each image set.

Methods & Procedures: A rating instrument, based on an extensive review of literature and assessed and revised by graphic design and eye‐tracking experts, was developed to identify such influences within multiple‐choice images and was assessed through empirical testing of viewers' eye movement patterns as they looked at images from published aphasia tests. A total of 20 adults rated 20 image sets from five aphasia batteries. Eye movements were recorded for a separate group of 40 adults viewing the same images.

Outcomes & Results: Ratings were not statistically correlated with eye movement responses. All multiple‐choice image sets prompted significantly disproportionate visual attention.

Conclusions: Results highlight the importance of: (1) considering the possible influence of visual stimulus confounds on any given patient's test performance, and (2) better controlled image design for multiple‐choice test images to improve the validity of assessment. Further research is needed to improve subjective and objective means of assessment of images and guidelines for improved design of multiple‐choice image displays.     

Metagenomic analysis of the peri-implant and periodontal microflora in patients with clinical signs of gingivitis or mucositis

The long-term success of osseointegrated oral implants is endangered by inflammation of peri-implant hard and soft tissues caused by bacterial biofilms that may have been initiated by bacterial transmission from the adjacent dentition. The present study aimed to compare the bacterial communities at inflamed implant and tooth sites by broad-range PCR techniques to evaluate the etiological processes of peri-implant and periodontal diseases and potential future therapeutic strategies. Eighteen samples of peri-implant and periodontal microflora were collected from nine partially edentulous patients with implant-retained crowns or bridges revealing clinical signs of gingivitis or mucositis. The clinical parameters plaque index (PI), probing depth (PD), and bleeding on probing were recorded. Amplified fragments of bacterial 16S rRNA genes were separated by use of single-strand conformation polymorphism analysis, and sequences were determined to identify the predominant bacterial genera. The clinical parameters PI and PD were significantly different at implants (PI = 0.4 ± 0.7, PD = 3.1 ± 0.6 mm) compared with teeth (PI = 1.8 ± 0.8, PD = 2.5 ± 0.2 mm). A total of 20 different genera were found at the inflamed tooth and implant sites. The microbial diversity of the microflora surrounding the remaining dentition (12.0 ± 3.8) was significantly higher (p = 0.01) than the diversity of the peri-implant microflora at implant-retained crowns or bridges (6.3 ± 2.3). Within the limitations of the present study, the microbial diversity of the investigated implants and teeth with clinical signs of mucositis or gingivitis exhibits substantial differences, demonstrating that transmission of the complete bacterial microflora from teeth to implants could be excluded. Furthermore, broad-range molecular biological detection methods specify bacterial genera and species in the peri-implant and periodontal microflora which were not in the focus of research interests so far.     

Feasibility of video-assisted bilateral neck exploration for patients with primary hyperparathyroidism and failed or discordant localization studies

Purpose

Minimally invasive video-assisted parathyroidectomy (MIVAP) is generally adopted for patients affected by primary hyperparathyroidism (pHPT) with clear preoperative localization. Standard bilateral neck exploration (BNE) is considered the obligate surgery for patients with unlocalized glands. We reviewed our experience of minimally invasive video-assisted BNE in patients with pHPT and negative or discordant localization studies.

Methods

From a prospective series of 576 MIVAP for pHPT, 107 patients (19 males, 88 females; mean age 58 years) with failed localization studies underwent BNE using the video-assisted technique. Operative time, complications, conversions to standard cervical exploration, and cure rate were analyzed.

Results

MIVAP with BNE was successfully completed in 99 (93 %) patients with 8 conversions. Mean operative time was 57?±?37 min (range 20–180 min). Permanent recurrent laryngeal nerve palsy occurred in one patient. Biochemical cure was achieved in 104 patients (97 %). Five patients required a reoperation in the immediate postoperative period, which achieved cure in four. Two patients remained with persistent disease; one developed recurrence disease 3 years after the first exploration.

Conclusion

In experienced hands, video-assisted BNE for pHPT is feasible and safe and provides results equivalent to the conventional open technique.     

Wave-particle dualism and complementarity unraveled by a different mode

The precise knowledge of one of two complementary experimental outcomes prevents us from obtaining complete information about the other one. This formulation of Niels Bohr's principle of complementarity when applied to the paradigm of wave-particle dualism--that is, to Young's double-slit experiment--implies that the information about the slit through which a quantum particle has passed erases interference. In the present paper we report a double-slit experiment using two photons created by spontaneous parametric down-conversion where we observe interference in the signal photon despite the fact that we have located it in one of the slits due to its entanglement with the idler photon. This surprising aspect of complementarity comes to light by our special choice of the TEM(01) pump mode. According to quantum field theory the signal photon is then in a coherent superposition of two distinct wave vectors giving rise to interference fringes analogous to two mechanical slits.     

Application of a calibration method provides more realistic results for a finite element model of a lumbar spinal segment

BACKGROUND: An important step in finite element modeling is the process of validation to derive clinical relevant data. It can be assumed that defect states of a finite element model, which have not been validated before, may predict wrong results. The purpose of this study was to show the differences in accuracy between a calibrated and a non-calibrated finite element model of a lumbar spinal segment for different clinical defects. METHODS: For this study, two geometrically identical finite element models were used. An in vitro experiment was designed, deriving data for the calibration. Frequently used material properties were obtained from the literature and transferred into the non-calibrated model. Both models were validated on three clinical defects: bilateral hemifacetectomy, nucleotomy and interspinous defects, whereas in vitro range of motion data served as control points. Predictability and accuracy of the calibrated and non-calibrated finite element model were evaluated and compared. FINDINGS: Both finite element models could mimic the intact situation with a good agreement. In the defects, the calibrated model predicted motion behavior with excellent agreement, whereas the non-calibrated model diverged greatly. INTERPRETATION: Investigating the biomechanical performance of implants and load distribution of different spinal structures by numerical analysis requires not only good agreement with the intact segment, but also with the defect states, which are initiated prior to implant insertion. Because of more realistic results the calibration method may be recommended, however, it is more time consuming.     

Inhibition of MDMA-induced increase in cortisol does not prevent acute impairment of verbal memory

Background

Ecstasy use is commonly linked with memory deficits in abstinent ecstasy users. Similar impairments are being found during ecstasy intoxication after single doses of ± 3,4 metylenedioxymethamphetamine (MDMA). The concordance of memory impairments during intoxication and abstinence suggests a similar neuropharmacological mechanism underlying acute and chronic memory impairments. The mechanism underlying this impairment is to date not known. We hypothesized that cortisol might play an important role in this mechanism as cortisol, implicated in the regulation of memory performance, can be brought out of balance by stressors like MDMA.

Methods

In the present study, we aimed to block the MDMA-induced acute memory defect by giving participants a cortisol synthesis inhibitor (metyrapone) together with a single dose of MDMA. Seventeen polydrug MDMA users entered this placebo-controlled within subject study with four treatment conditions. The treatments consisted of MDMA (75 mg) and metyrapone (750 mg), alone and in combination, and double placebo. Pre-treatment with metyrapone or Placebo occurred 1 h prior to MDMA or Placebo administration. Memory performance was tested at peak drug concentrations by means of several memory tests. Cortisol levels were determined in blood and oral fluid; this served as a control measure to see whether manipulations were effective.

Results

Main findings indicated that whereas treatment with metyrapone blocked the expected MDMA-induced increase in cortisol levels in blood, it did not prevent the MDMA-induced memory deficit from happening.

Conclusion

We therefore conclude that MDMA-induced increments in cortisol concentrations are not related to MDMA-induced memory impairments.     

Can breathing circuit filters help prevent the spread of influenza A (H1N1) virus from intubated patients?

Introduction: In March 2010, more than 213 countries worldwide reported laboratory confirmed cases of influenza H1N1 infections with at least 16,813 deaths. In some countries, roughly 10 to 30% of the hospitalized patients were admitted to the ICU and up to 70% of those required mechanical ventilation. The question now arises whether breathing system filters can prevent virus particles from an infected patient from entering the breathing system and passing through the ventilator into the ambient air.We tested the filters routinely used in our institution for their removal efficacy and efficiency for the influenza virus A H1N1 (A/PR/8/34).Methods: Laboratory investigation of three filters (PALL Ultipor^® 25, Ultipor^® 100 and Pall BB50T Breathing Circuit Filter, manufactured by Pall Life Sciences) using a monodispersed aerosol of human influenza A (H1N1) virus in an air stream model with virus particles quantified as cytopathic effects in cultured canine kidney cells (MDCK). Results: The initial viral load of 7.74±0.27 log₁₀ was reduced to a viral load of ≤2.43 log₁₀, behind the filter. This represents a viral filtration efficiency of ≥99.9995%. Conclusion: The three tested filters retained the virus input, indicating that their use in the breathing systems of intubated and mechanically ventilated patients can reduce the risk of spreading the virus to the breathing system and the ambient air.     

Health-related quality of life in autoimmune hepatitis

Autoimmune hepatitis (AIH) is a severe chronic autoimmune disease and has a significant impact on the patient’s quality of life, in particular regarding psychological problems such as anxiety and depression. Consistent evidence on which patient-related, disease-related or physician-related factors cause health-related quality of life (HRQoL) impairment in patients with AIH is lacking. Current studies on HRQoL in AIH are mainly single-centered, comprising small numbers of patients, and difficult to compare because of the use of different questionnaires, patient populations, and cutoff values. Literature in the pediatric field is sparse, but suggests that children/adolescents with AIH have a lower HRQoL. Knowledge of HRQoL and cohesive factors in AIH are important to improve healthcare for AIH patients, for example by developing an AIH-specific chronic healthcare model. By recognizing the importance of quality of life beyond the concept of biochemical and histological remission, clinicians allow us to seek enhancements and possible interventions in the management of AIH, aiming at improved health.