Comparison of artefact reduction possibilities with the new active transcutaneous bone conduction implant (Bonebridge)

OBJECTIVE

This study aimed to evaluate the possibilities of artefact reduction using different anatomical implant positions with the Bonebridge bone-conduction hearing implant 602 for a patient with an acoustic neuroma requiring regular diagnostic magnetic resonance imaging of the tumour position.

METHOD

Three implant positions and magnetic resonance imaging examinations with and without customised sequences for metal artefact suppression were investigated. The diagnostic usefulness was rated by a radiologist (qualitative evaluation), and the relation between the area of artefact and the total head area was calculated (quantitative evaluation).

RESULTS

Following the qualitative analysis, the radiologist rated the superior to middle fossa implant placement significantly better for diagnostic purposes, which is in agreement with the calculated artefact ratio (p < 0.0001). The customised slice-encoding metal artifact correction view-angle tilting metal artifact reduction technique sequences significantly decreased the relative artefact area between 5.13 per cent and 25.02 per cent. The smallest mean artefact diameter was found for the superior to middle fossa position with 6.80 ± 1.30 cm (range: 5.42-9.74 cm; reduction of 18.65 per cent).

CONCLUSION

The application of artefact reduction sequencing and special anatomical implant positioning allows regular magnetic resonance imaging in patients with the bone-conduction hearing implant 602 without sacrificing diagnostic imaging quality for tumour diagnosis.

Towards a consensus on a hearing preservation classification system

CONCLUSION

The comprehensive Hearing Preservation classification system presented in this paper is suitable for use for all cochlear implant users with measurable pre-operative residual hearing. If adopted as a universal reporting standard, as it was designed to be, it should prove highly beneficial by enabling future studies to quickly and easily compare the results of previous studies and meta-analyze their data.

OBJECTIVES

To develop a comprehensive Hearing Preservation classification system suitable for use for all cochlear implant users with measurable pre-operative residual hearing.

METHODS

The HEARRING group discussed and reviewed a number of different propositions of a HP classification systems and reviewed critical appraisals to develop a qualitative system in accordance with the prerequisites.

RESULTS

The Hearing Preservation Classification System proposed herein fulfills the following necessary criteria: 1) classification is independent from users' initial hearing, 2) it is appropriate for all cochlear implant users with measurable pre-operative residual hearing, 3) it covers the whole range of pure tone average from 0 to 120 dB; 4) it is easy to use and easy to understand.

How successful are oncologists in identifying patient distress, perceived social support, and need for psychosocial counselling?

20-40% of cancer patients show emotional distress. Psychosocial support should be offered to severely distressed patients. However, little is known about the selection of patients to whom such support should be offered. This study investigated oncologists' ability to identify such patients. In a consecutive series of 298 cancer patients undergoing radiotherapy, distress, perceived social support and desire for supportive counselling were assessed using screening instruments. Simultaneously, 8 oncologists estimated patient distress and need for psychosocial support. A complete set of data was obtained in 80.2% of cases. Concordance of the oncologists' estimation of patient distress and perceived social support with the results of the screening instruments was weak (kappa = 0.10 and kappa = 0.05). Oncologists recognized the presence of severe distress only in 11 of the 30 severely distressed patients. Correct perception of distress was lower in patients with head and neck cancer and lung cancer and in lower class patients. Oncologists' recommendations for supportive counselling did not correlate with patient distress or the amount of perceived support but rather with progressive disease and less denial behaviour. Our results underline the need for educating oncologists in order to improve their ability to identify patient distress.

B cell-mediated infection of stimulated and unstimulated autologous T lymphocytes with HIV-1: role of complement

In vivo, human immunodeficiency virus type 1 (HIV-1) is opsonized with complement fragments and virus-specific antibodies (Ab). Thus, HIV is able to interact with complement receptor (CR) - and Fc receptor (FcR) - positive cells such as B cells, follicular dendritic cells or macrophages. In this study we demonstrate that the interaction between B cells and HIV has an impact on autologous primary T cell infection in vitro. We confirmed the presence of complement-fragments and virus-specific Ab on serum-treated HIV using a virus-capture assay. In experiments with CR2-specific Ab we showed that the virus/B cell interaction was mainly dependent on CR2. In infection experiments immobilisation of HIV on stimulated tonsil B cells greatly enhanced the infection of interleukin (IL)-2-activated autologous tonsil T cells. Surprisingly, enhancement of T cell infection by B cell-HIV complexes was observed even in the absence of mitogenic stimuli such as PMA and was independent of the addition of exogenous IL-2. Taken together, these results indicate that primary B cells are able to efficiently transmit opsonised HIV to autologous primary T cells and induce a massive enhancement of infection. These in vitro experiments mimic the in vivo situation in the lymphoid tissue and suggest an alternative mechanism for the infection of primary T cells.

Plastination: a new approach to morphological research and instruction with excised larynges

Impregnation of biologic materials with curable polymer (plastination) allows wider use of human tissue for both basic and clinical research and instruction. The aim of this study was to determine for the first time the potential of this method in the field of laryngology. A feasibility study on 54 pig larynges established a detailed methodology for larynx plastination and determined the extent of shrinkage by using computer-assisted morphometry. The process involves dehydration, saturation with an appropriate intermediate solvent, and infiltration with cured polymer in vacuo. In the main study 20 fresh, intact human larynges and 12 laryngectomy specimens were submitted to plastination. The resulting resin blocks were cut with a diamond band saw into 0.8-mm sections in the transaxial plane. The resulting specimens are dry, odorless, and durable, and do not deteriorate with time. The subtle features of soft tissue pathology are well preserved. Shrinkage of plastinated larynges is less than 10%. The complete process is accomplished within 5 weeks. Staining of sections with toluidine blue provides an enhanced contrast between different types of tissue, allowing a clear identification of tumor invasion. Plastination is considerably faster than celloidin embedding and causes minor anatomic changes. It provides durable specimens of high quality for teaching purposes. In research, it allows the investigation of all tissue components in their undisturbed context in the borderline area between gross anatomy and histology.

[Clinical morphology of the sternum]

The length, width and thickness of the sternum were measured in 74 adult specimens with the aim of optimizing the dimensions of staples used after sternotomy. This article describes the experimental procedure and presents the results. Sex differences were confined mainly to the length, with males measuring 16.5 cm, and females 15 cm. Width and thickness maxima (7.4 cm and 1.7 cm, respectively) are measured at the proximal and distal ends of the manubrium, while the width and thickness of the corpus (2.7-3.5 cm and 1.0-1.4 cm, respectively) show relatively minor differences.