Early attention effects in human auditory-evoked potentials

A fundamental question in attention theory concerns the earliest processing stages that can be modulated by selective attention. A series of experiments is reported in which very early attention effects are found under specific conditions in the frequency-following potential (FFP), a brain stem response to low-frequency tone stimuli. In two experiments, stimuli of two different modalities were applied, and attention directed to one of the modalities. In two further experiments, only auditory stimuli were presented. In the first of these last two experiments, a dichotic paradigm with sustained attention to one ear was used, in the second a monotic paired-stimuli paradigm was used, in which the first stimulus served as reference for the second one. Only in the last experiment significant attention effects were found in the latency, but not in the amplitude of the FFP. The results show that a very early attention effect on the latency of the FFP can be demonstrated, but only under highly specific conditions. The size and preconditions of the attention effect suggest that it reflects subtle intramodal tuning mechanisms in the cochlea or in the lower brain stem.     

Evaluation of subretinal triamcinolone acetonide in patients with exudative age-related macular degeneration.

PURPOSE: The aim of this paper was to present the results of subretinal delivery of triamcinolone acetonide (TCA) in humans with choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD). METHODS: Twenty two (22) eyes of 22 patients underwent pars plana vitrectomy with subretinal TCA administration. Two milligrams (2 mg) of preservative-free TCA were delivered through a 32-gauge automatic subretinal injector in 20 microL of volume. Visual acuity, fluorescein angiography (FA), and intraocular pressure (IOP) were recorded and compared pre- and postoperatively. RESULTS: Preoperative average+/-standard deviation visual acuity in the treated eye was 1.408+/-0.129 (logMAR; median 20/400) and 1.403+/-0.114 (logMAR; median 20/300) postoperatively (P=0.51). The mean area of pre- and postoperative FA leakage in the operated eyes was 21.31+/-1.125 and 19.29+/-1.108 mm2, respectively (P=0.04). The average IOP value before treatment was 15.3+/-0.78 mmHg. Three (3) months after surgery, it was 20.5+/-2.04 mmHg (P=0.02). Six (6) months and 1 year after surgery, the average IOP was 17.0+/-0.66 mmHg (P=0.9) and 15.6+/-1.02 mmHg (P=0.6), respectively. CONCLUSIONS: Subretinal TCA stabilizes visual acuity, decreases FA leakage in eyes with CNV owing to AMD, and does not increase IOP, as seen with intravitreous injections.     

Relationships, trust, decision-making and quality of care in a paediatric intensive care unit

Objective  To assess the care-giving practices of health-care practitioners in the paediatric intensive care unit (PICU) through their qualitative insights, reflections and experience in participatory action research. Design and methods  Qualitative research in the form of ‘participatory action research’ was used to gather data from three sources within the unit: focus groups within disciplines, observations within the PICU, and semi-structured interviews. All staff members were active collaborators and equal stakeholders in the decision-making process, research and feedback. Setting  The paediatric intensive care unit (PICU) of the Red Cross War Memorial Children’s Hospital (RCWMCH). Participants  All staff members from various disciplines working in the PICU. Results  Staff members described problems with respect to relationships, trust and decision-making within care-giving practices. Conclusion  The study qualitatively describes how poor communication amongst staff members in respect of relationships and decision-making impacted on trust and how this tended to compromise care-giving practices in the PICU. The data suggested that this was more evident in informal rather than formal clinical decision-making procedures. The strength of the study was that the participatory action design in the research allowed staff members to address the very dynamics that they themselves cited as problematic.     

Specific progesterone binding to a membrane protein and related nongenomic effects on Ca2+-fluxes in sperm

Rapid, nongenomic effects of steroids are supposed to be transmitted by membrane receptors unrelated to the classic intracellular steroid receptors. In this context, a putative progesterone membrane binding protein (mPR) has been identified, recently. Here we show that expression of mPR-cDNA in CHO cells leads to increased microsomal progesterone binding. This result is mirrored by effects of an antibody raised against the recombinant E. coli mPR which suppressed the rapid progesterone-initiated Ca2+ increase in sperm. Our results support the assumption that mPR represents the first steroid membrane receptor or a part of it involved in rapid, nongenomic steroid signalling.