A directional remote-microphone for bimodal cochlear implant recipients

Abstract

To evaluate whether speech recognition in noise differs according to whether a wireless remote microphone is connected to just the cochlear implant (CI) or to both the CI and to the hearing aid (HA) in bimodal CI users. The second aim was to evaluate the additional benefit of the directional microphone mode compared with the omnidirectional microphone mode of the wireless microphone. This prospective study measured Speech Recognition Thresholds (SRT) in babble noise in a ‘within-subjects repeated measures design’ for different listening conditions. Eighteen postlingually deafened adult bimodal CI users. No difference in speech recognition in noise in the bimodal listening condition was found between the wireless microphone connected to the CI only and to both the CI and the HA. An improvement of 4.1?dB was found for switching from the omnidirectional microphone mode to the directional mode in the CI only condition. The use of a wireless microphone improved speech recognition in noise for bimodal CI users. The use of the directional microphone mode led to a substantial additional improvement of speech perception in noise for situations with one target signal.     

Quantifying the biodiversity value of tropical primary, secondary, and plantation forests

Biodiversity loss from deforestation may be partly offset by the expansion of secondary forests and plantation forestry in the tropics. However, our current knowledge of the value of these habitats for biodiversity conservation is limited to very few taxa, and many studies are severely confounded by methodological shortcomings. We examined the conservation value of tropical primary, secondary, and plantation forests for 15 taxonomic groups using a robust and replicated sample design that minimized edge effects. Different taxa varied markedly in their response to patterns of land use in terms of species richness and the percentage of species restricted to primary forest (varying from 5% to 57%), yet almost all between-forest comparisons showed marked differences in community structure and composition. Cross-taxon congruence in response patterns was very weak when evaluated using abundance or species richness data, but much stronger when using metrics based upon community similarity. Our results show that, whereas the biodiversity indicator group concept may hold some validity for several taxa that are frequently sampled (such as birds and fruit-feeding butterflies), it fails for those exhibiting highly idiosyncratic responses to tropical land-use change (including highly vagile species groups such as bats and orchid bees), highlighting the problems associated with quantifying the biodiversity value of anthropogenic habitats. Finally, although we show that areas of native regeneration and exotic tree plantations can provide complementary conservation services, we also provide clear empirical evidence demonstrating the irreplaceable value of primary forests.     

Catechol-O-methyltranferase gene expression is associated with response to citalopram in obsessive-compulsive disorder

Objective. To determine whether polymorphisms of the dopamine D(2) receptor (DRD2) and catechol-O-methyl-transferase (COMT) receptor genes affect the efficacy of quetiapine addition to citalopram in patients with OCD. Methods. Sixty-four drug-free or drug-na?ve patients meeting DSM-IV criteria for OCD were randomized to 10 weeks double-blind treatment with citalopram (60 mg/day) with quetiapine (300 -450 mg/day) or with placebo. The change from baseline to endpoint on the total Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the response to treatment were the primary outcome measures. Response was defined as a 25% decrease in Y-BOCS score. Responders and nonresponders were stratified according to DRD2 TaqI A and COMT Val(158)Met genotypes. Results. No significant differences in genotype distribution or allele frequencies of the COMT or DRD2 receptor were found between responders and nonresponders to citalopram with quetiapine. However, nearly half of responders to citalopram with placebo carried the Met/Met (48%) genotype of the COMT polymorphism compared to none of the nonresponders (χ(2) = 10.06, df = 2, P = 0.007). Conclusions. The Met allele load of the COMT receptor gene was associated with response to 10 weeks of treatment with citalopram in drug-free or drug-na?ve OCD patients.     

Added value of CA19-9 response in predicting resectability of locally advanced pancreatic cancer following induction chemotherapy

Background

Determining the resectability of locally advanced pancreatic cancer (LAPC) after induction chemotherapy is complex since CT-imaging cannot accurately portray tumor response. We hypothesized that CA19-9 response adds to RECIST-staging in predicting resectability of LAPC.

Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients

Objectives

Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims.

Materials and methods

First, volunteers brushed 2?weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12?h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis.

Results

The viabilities of plaques after brushing with Colgate-Total? and Crest-Pro-Health? were smaller than of control plaques and up to 12?h after brushing with Crest-Pro-Health? plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes.

Conclusions

Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health?).

Clinical relevance

The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.     

Thyroid and adrenal axis in major depression: a controlled study in outpatients

OBJECTIVE: Major depressive disorder has been associated with changes in the hypothalamus-pituitary-thyroid (HPT) axis and with hypercortisolism. However, the changes reported have been at variance, probably related to in- or outpatient status, the use of antidepressant medication and the heterogeneity of depression. We therefore conducted a controlled study in unipolar depressed outpatients who had been free of antidepressants for at least 3 months. DESIGN: We assessed endocrine parameters in 113 depressed outpatients and in 113 sex- and age-matched controls. METHODS: Patients were included if they had a major depression according to a Structural Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (DSM), fourth edition (SCID-IV) and if they had a 17-item Hamilton rating scale for depression (HRSD) score of > or =16. Endocrine parameters contained serum concentrations of TSH, (free) thyroxine, tri-iodothyronine, cortisol, thyroid peroxidase (TPO) antibody titre and 24-h urinary excretion of cortisol. RESULTS: The serum concentration of TSH was slightly higher in depressed patients as compared with controls (P < 0.001), independent of the presence of subclinical hypothyroidism and/or TPO antibodies (n = 28). All other HPT axis parameters were similar in both groups. The 24-h urinary cortisol excretion was similar in patients and controls. In atypical depression, serum cortisol was lower than in non-atypical depression (P = 0.01). Patients with neither melancholic depression nor severe depression (HRSD > or =23) had altered endocrine parameters. Finally, serum TSH values could not be related to cortisol values. CONCLUSION: When compared with matched control subjects, outpatients with major depression had slightly higher serum TSH, while urinary cortisol levels were similar. Furthermore, we observed lower serum cortisol in atypical depression than in non-atypical depression.     

Glucocorticoids and relapse of major depression (dexamethasone/corticotropin-releasing hormone test in relation to relapse of major depression).

BACKGROUND: Knowledge of pathogenic mechanisms and predictors of relapse in major depressive disorder is still limited. Hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation is thought to be related to the development and course of depression. METHODS: We investigated whether dexamethasone/corticotropin-releasing hormone (DEX/CRH) test parameters were related to the occurrence of relapse in 45 outpatients with clinically remitted major depression. The DEX/CRH test was administered before and after 8 weeks of antidepressant treatment. RESULTS: Posttreatment maximal adrenocorticotropic hormone (ACTH) and maximal cortisol levels, as well as delta ACTH and delta cortisol levels, were significantly higher (all p < .05) among patients who relapsed (n = 22) compared with patients in whom no relapse occurred (n = 23). Higher posttreatment maximal cortisol response on the DEX/CRH test was associated with shorter "relapse-free survival" (p = .05). CONCLUSIONS: In outpatients with clinically remitted major depression, higher posttreatment maximal cortisol levels on the DEX/CRH test were associated with relapse of major depression.     

Longitudinal studies of experimental otitis media with Haemophilus influenzae in the gerbil

Haemophilus influenzae non-typable strain 119 was found to cause severe otitis media with sequellae when inoculated into the middle ear cavities of the Mongolian gerbil, Meriones unguiculatus. Acute inflammation was followed by the development of highly vascular granulation tissue and formation of new bone within the middle ear bulla. These changes persisted throughout the 14-week study in the untreated animals. The gerbil was variably susceptible to otitis media caused by inoculating 30-3000 bacterial cells and 100% susceptible to greater than 3000 cells. The susceptibility of the gerbil to common etiological agents of otitis media allows its use as an appropriate model of the disease.     

Tissue responses against immunoisolating alginate-PLL capsules in the immediate posttransplant period

Alginate-polylysine (PLL) capsules are commonly applied for immunoisolation of living cells for the treatment of a wide variety of diseases. Large-scale application of the technique, however, is hampered by insufficient biocompatibility of the capsules with failure of the grafts as a consequence. Most studies addressing biocompatibility issues of alginate-PLL capsules have focused on the degree of overgrowth on the capsules after graft failure and not on the reaction against the capsules in the immediate posttransplant period. Therefore, capsules were implanted in the peritoneal cavity of rats and retrieved 1, 5, and 7 days later for histological examination and X-ray photoelectron spectroscopy analysis for evaluation of chemical changes at the capsule surface. After implantation, the nitrogen signal increased from 5% on day 0, to 8.6% on day 7, illustrating protein adsorption on the capsule's surface. This increase in protein content of the membrane was accompanied by an increase in the percentage of overgrown capsules from 0.5 +/- 0.3% on day 1 to 3.3 +/- 1.6% on day 7. The cellular overgrowth was composed of monocytes/macrophages, granulocytes, fibroblasts, erythrocytes, multinucleated giant cells, and basophils. This overgrowth was not statical as generally assumed but rather dynamic as illustrated by our observation that at day 1 after implantation we mainly found monocytes/macrophages and granulocytes that on later time points were substituted by fibroblasts. As the inflammatory reaction predictably interfere with survival of encapsulated cells, efforts should be made to suppress activities or recruitment of inflammatory cells. These efforts may be temporary rather than permanent because most inflammatory cells have disappeared after 2 weeks of implantation.