Trade-offs between better hearing and better cosmetics

A case study is reported of an adult bilateral cochlear implant patient who owns both a pair of ear-level and body-worn speech processors and chooses to wear them in unique configurations, knowingly compromising his auditory performance. The aim was to determine if differences in hearing could be quantified between these devices and to examine the size of these effects that would lend themselves to trading between performance and cosmetics. The patient reported wearing bilateral ear-level speech processors (programmed with the Cochlear Corporation spectral PEAK [SPEAK] coding strategy) 75% of the time for cosmetic and convenience reasons even though he "heard the best" with bilateral body-worn speech processors (programmed with the Cochlear Corporation advanced combination encoder strategy [ACE]). Speech perception and localization tests confirmed that this patient performed significantly better on monosyllabic phonemes in quiet (a difference from 60% to 75%) and localization (a total root-mean-squared-error difference from 22 degrees to 12degrees ) with bilateral body-worn speech processors and consistently rated various speech sounds as more clear than with bilateral ear-level units. There was a 2-dB difference in sentence reception threshold in noise, which was not statistically significant. These results suggest that clinicians should consider and provide options to patients when there are trade-offs to be made regarding understanding performance and cosmetics. Some individuals may choose better speech perception over cosmetics, and the ability to choose might result in greater compliance. The observations made here are relevant to hearing aid users as well.     

Protocol for the evaluation of a decision aid for women with a breech-presenting baby [ISRCTN14570598]

Background  

There is now good evidence about the management options for pregnant women with a breech presentation (buttocks or feet rather than head-first) at term; external cephalic version (ECV) – the turning of a breech baby to a head-down position and/or planned caesarean section (CS). Each of these options has benefits and risks and the relative importance of these vary for each woman, subject to her personal values and preferences, a situation where a decision aid may be helpful.     

Identification of factors promoting abstinence from smoking in a cohort of elementary schoolchildren

BACKGROUND: Despite the progress made in smoking prevention among youth, few scientific reports have identified the determinants underlying the abstinence from cigarettes, and even fewer have made an assessment of their evolution over time. It has been proposed that this could be done by modeling after theoretical frameworks. METHODS: A self-reported questionnaire developed according to Ajzen's Theory of Planned Behavior was repeatedly administered to a cohort of 373 grade 5 students (191 girls and 182 boys) during their transition from elementary to secondary school. Four measures spanning a 26-month period were thus obtained and analyzed according to the GEE method. RESULTS: After 26 months, 76.14% of the students in the sample remained abstinent from cigarettes. The perceived smoking behaviors of friends and of a brother, intention over time, perceived self-efficacy, parental supervision, and socioeconomic status predicted the maintenance of abstinence from smoking. The final predictive model had a sensitivity of 79.8% and a specificity of 75.6%, with an average rate of accurate classification of 79.1%. CONCLUSIONS: The predictive model yielded by this study represents an important step toward developing tools to help 10-12 years olds maintaining their abstinent behavior. It emphasizes positive protective factors and guides health promoters in the choice of their interventions' contents and targets.     

The neurodegeneration sequence in prion diseases: evidence from functional, morphological and ultrastructural studies of the GABAergic system

Loss of the GABAergic system of neurons has been reported to be the first detectable neuropathological change in prion diseases, which features the accumulation of an aberrant isoform of the prion protein (PrP(Sc)). To determine the timing of GABAergic system dysfunction and degeneration and its relationship to PrP(Sc) accumulation during the course of prion disease in Syrian hamsters, we applied 3 approaches: i) quantifying GABA-immunopositive neurons and their processes by light and electron microscopy to test for selective loss; ii) measuring evoked [3H]-GABA release from synaptosomes to test for functional abnormalities; and iii) determining the kinetics of PrP(Sc) accumulation in subcellular fractions to correlate it with GABAergic dysfunction. At the terminal stages of disease, we found a significant increase in the number of GABA-positive and -negative presynaptic boutons with abnormally aggregated synaptic vesicles. At the same stage, we also found an equal degree of GABA-immunopositive and -immunonegative presynaptic bouton loss. In contrast, GABA-positive neocortical cell bodies increased, based on stereologic estimates in the terminal stage of scrapie. In the context of these abnormalities, evoked release of [3H]-GABA from cortical and thalamic synaptosomes was significantly decreased, which correlated well with the accumulation of PrP(Sc) in synaptosomes and cell membrane fractions.     

The impact of a single-layer or double-layer closure on uterine rupture

OBJECTIVE: Our purpose was to measure the impact of a single-layer or double-layer closure on uterine rupture at subsequent delivery. STUDY DESIGN: This is an observational cohort study of all women undergoing a trial of labor from 1988 to 2000 in a tertiary care center, after a single low transverse cesarean delivery. Factors most highly associated with uterine rupture were identified by using univariate regression analysis. Multivariate logistic regression analysis was used to adjust for selected confounding variables. RESULTS: Of the 2142 women who met the study criteria, 1980 (92.4%) had maternal records and original operative reports reviewed. After adjustments were made for confounding variables, the odds ratio for uterine rupture in women with a single-layer closure was 3.95 (95% CI, 1.35-11.49). CONCLUSION: A single-layer closure of the previous lower segment incision was the most influential factor and was associated with a 4-fold increase in the risk of uterine rupture compared with a double-layer closure.     

Reference frames in early motion detection

To perceive the real motion of objects in the world while moving the eyes, retinal motion signals must be compensated by information about eye movements. Here we study when this compensation takes place in the course of visual processing, and whether uncompensated motion signals are ever available. We used a paradigm based on asymmetry in motion detection: Fast-moving objects are found easier among slow-moving distractors than are slow objects among fast distractors. By coupling object motion to eye motion, we created stimuli that moved fast on the retina but slowly in an eye-independent reference frame, or vice versa. In the 100 ms after stimulus onset, motion detection is dominated by retinal motion, uncompensated for eye movements. As early as 130 ms, compensated signals become available: objects that move slowly on the retina but fast in an eye-independent frame are detected as easily as those that move fast on the retina.     

Cellular DNA content parameters as prognostic indicators in human astrocytomas

Objective: Clinical parameters such as grade, size and/or location of the tumor are good predictors of outcome in patients with astrocytoma. The objective of this study was to determine whether DNA content parameters have a prognostic significance for this group of tumors.Methods: Following optimization and validation of methodology for evaluating cellular DNA content parameters (CDCP), tumor DNA ploidy and percent S phase fraction (SPF) were determined from 64 patients using formalin fixed, paraffin embedded specimens (mean coefficient of variation = 4.94) obtained over a 10-year period. Median survival times correlated with grade (I/II =1154 vs. III/IV= 483days, P=0.0317). Fifty-five percent of the specimens contained DNA aneuploid (DNA-A) components (average SPF=18.3%) and 45% were DNA diploid (DNA-D) (average SPF=9.6%). Survival did not correlate with overall differences in DNA ploidy (DNA-D=181 vs. DNA-A=206days, P=0.6314) when treated and untreated tumors were analyzed. However, a trend for prolonged median survival was observed in patients whose tumors were untreated with respect to cytotoxic therapy based on DNA ploidy status (DNA-D=275 vs. DNA-A=15days, P=0.3408). Survival for all patients did not correlate with median SPF (< 13.5% av.= 121 vs. > 13.5% av.= 154days, P=0.6534).Conclusion: DNA content parameters may correlate with the natural history and treatment outcome of newly diagnosed untreated patients with astrocytomas.Supported by NIH CA 40498–01A1; NIH P30CA22453