Acute healing outcomes in paediatric partial thickness burns using Epiprotect® and Biobrane®: A retrospective comparative study.

AIM: To compare the acute healing outcomes of Biobrane® and Epiprotect® in paediatric partial thickness (PT) burns. METHODS: All paediatric patients (age <18 years) with PT burns managed using either Biobrane® or Epiprotect® over a 5-year period at our burns unit were included. The primary outcome was time to complete healing. Secondary outcomes included adherence, infection rates, length of hospital stay, duration of acute follow-up and return to the theatre. RESULTS: Among the 99 patients included, 38 received Epiprotect® and 61 received Biobrane®. The mean total body surface area (TBSA) was 6% (range 1%-15%) and median age was 21 months (range 5-169 months). Median time to healing in the Epiprotect® group was 19.5 days and 16 days in the Biobrane® group (P = .14). The median hospitalisation length was the same for both products (2 days, P = .85). Infection rate was lower in the Epiprotect® group (2.6% vs 16.4%, P = .048). There was no difference in adherence rate. These trends were preserved when depth sub-groups were analysed. Adherence and infection rates were not affected by post-operative antibiotics (P > .99 and P = .65, respectively) in either group. The rate of return to the theatre for further surgery was 13.2% for both products (P > .99). CONCLUSION: Our findings demonstrate that acute healing outcomes with Epiprotect® in paediatric PT burns are comparable to those with Biobrane®, with significantly lower infection rates for Epiprotect®. These results suggest that Epiprotect® is a viable alternative to Biobrane®. Nevertheless, further prospective randomised studies are required to investigate the short- and long-term outcomes.

[FALL PREDICTION AND FALL SEVERITY IN REHABILITATION HOSPITAL].

AIMS: We tested whether the Farmer questionnaire is valid for fall risk assessment in Hebrew. We tested whether NDNQI (National Database of Nursing Quality Indicators) is valid for fall severity evaluation in Hebrew. Finally, we tested whether the Farmer and NDNQI are correlated. BACKGROUND: Patients in rehabilitation hospitals are exposed to fall-risking conditions. Falls with severe outcomes can extend the hospitalization, and increase the workload on health systems. Fall risk assessment at the beginning of hospitalization is crucial for making supportive and preventive adjustments. The Israel Ministry of Health obliges using fall risk assessment at hospitalization. Nonetheless, fall risk assessment has not been validated in Hebrew, and has not been tested for prediction power of fall severity outcome. METHODS: Farmer measurement was validated in 1187 patients retrospectively, out of whom 288 had fallen during hospitalization. Twenty-five fall cases with varying severities were ranked by 47 staff members for their fall severity score. Non-parametric Spearman's correlation was tested between Farmer and NDNQI measurements. RESULTS: Mean Farmer value of the falling group was larger than the mean Farmer value of the non-falling group (F=9.5, pv=0.002). Variability between raters was smaller than variability between conditions in NDNQI (ICC(2,1)=0.75). Farmer index was not correlated with NDNQI score (ρ=0.092, pv=0.118). CONCLUSIONS: Farmer measurement is a valid tool for fall risk assessment in Hebrew. NDNQI is a valid tool for evaluation of fall severity. Farmer index is not predictive of fall severity. DISCUSSION: There is a need for predictive measures of fall severity outcomes. We recommend using fall severity scores for ranking the intervention's success.

Recording odor-evoked response potentials at the human olfactory epithelium.

Electro-olfactogram (EOG) represents the sum of generator potentials of olfactory receptor neurons in response to an olfactory stimulus. Although this measurement technique has been used extensively in animal research, its use in human olfaction research has been relatively limited. To understand the promises and limitations of this technique, this review provides an overview of the olfactory epithelium structure and function, and summarizes EOG characteristics and conventions. It describes methodological pitfalls and their possible solutions, artifacts, and questions of debate in the field. In summary, EOG measurements provide a rare opportunity of recording neuronal input from the peripheral olfactory system, while simultaneously obtaining psychophysical responses in awake humans.

Neural activity at the human olfactory epithelium reflects olfactory perception.

Organization of receptive surfaces reflects primary axes of perception. In vision, retinal coordinates reflect spatial coordinates. In audition, cochlear coordinates reflect tonal coordinates. However, the rules underlying the organization of the olfactory receptive surface are unknown. To test the hypothesis that organization of the olfactory epithelium reflects olfactory perception, we inserted an electrode into the human olfactory epithelium to directly measure odorant-induced evoked responses. We found that pairwise differences in odorant pleasantness predicted pairwise differences in response magnitude; that is, a location that responded maximally to a pleasant odorant was likely to respond strongly to other pleasant odorants, and a location that responded maximally to an unpleasant odorant was likely to respond strongly to other unpleasant odorants. Moreover, the extent of an individual's perceptual span predicted their span in evoked response. This suggests that, similarly to receptor surfaces for vision and audition, organization of the olfactory receptor surface reflects key axes of perception.

The privileged brain representation of first olfactory associations.

Authors, poets, and scientists have been fascinated by the strength of childhood olfactory memories. Indeed, in long-term memory, the first odor-to-object association was stronger than subsequent associations of the same odor with other objects. Here we tested the hypothesis that first odor associations enjoy a privileged brain representation. Because emotion impacts memory, we further asked whether the pleasantness of an odor would influence such a representation. On day 1, we associated the same visual objects initially with one, and subsequently with a second, set of pleasant and unpleasant olfactory and auditory stimuli. One week later, we presented the same visual objects and tested odor-associative memory concurrent with functional magnetic resonance brain imaging. We found that the power (% remembered) of early associations was enhanced when they were unpleasant, regardless of whether they were olfactory or auditory. Brain imaging, however, revealed a unique hippocampal activation for early olfactory but not auditory associations, regardless of whether they were pleasant or unpleasant. Activity within the hippocampus on day 1 predicted the olfactory but not auditory associations that would be remembered one week later. These findings confirmed the hypothesis of a privileged brain representation for first olfactory associations.

Odorant concentration dependence in electroolfactograms recorded from the human olfactory epithelium.

Electroolfactograms (EOGs) are the summated generator potentials of olfactory receptor neurons measured directly from the olfactory epithelium. To validate the sensory origin of the human EOG, we set out to ask whether EOGs measured in humans were odorant concentration dependent. Each of 22 subjects (12 women, mean age = 23.3 yr) was tested with two odorants, either valeric acid and linalool (n = 12) or isovaleric acid and l-carvone (n = 10), each delivered at four concentrations diluted with warm (37 degrees C) and humidified (80%) odorless air. In behavior, increased odorant concentration was associated with increased perceived intensity (all F > 5, all P < 0.001). In EOG, increased odorant concentration was associated with increased area under the EOG curve (all F > 8, all P < 0.001). These findings substantiate EOG as a tool for probing olfactory coding directly at the level of olfactory receptor neurons in humans.

Measuring smells.

Olfaction consists of a set of transforms from a physical space of odorant molecules, through a neural space of information processing, and into a perceptual space of smell. Elucidating the rules governing these transforms depends on establishing valid metrics for each of the three spaces. Here we first briefly review the perceptual and neural spaces, and then concentrate on the physical space of odorant molecules. We argue that the lack of an agreed-upon odor metric poses a significant obstacle toward understanding the neurobiology of olfaction, and suggest two alternative odor metrics as possible solutions.

Prediction models for the pleasantness of binary mixtures in olfaction.

Whereas the rules underlying the perceived intensity of binary mixtures have been investigated, minimal efforts have been directed at elucidating the rules underlying the perceived pleasantness of such mixtures. To address this, 84 subjects ranked the pleasantness and intensity of 5 distinct binary mixtures (15 pairs, inter-stimulus interval = 4 s, inter-trial interval = 30 s, flow = 6 l/min, pulse = 2 s) constructed from different ratios (0:100%, 25:75%, 50:50%, 75:25%, and 100:0%, olfactometer-generated vapor phase). We found that in the majority of cases, the pleasantness of the mixture fell between the pleasantness values of its separated constituents and that it was strongly influenced by the relative intensities of the constituents. Based on these results, we proposed a prediction paradigm for the pleasantness of binary mixtures from the pleasantness of their separated constituents weighted by their respective perceived intensities. The uniqueness of the proposed paradigm is that it neither requires presetting an interaction constant between the mixture components nor require any factorization of the pleasantness weights. It does, nonetheless, require solid psychophysical data on the separated components at their different concentrations, and currently it can only explain the behavior of intermediate pleasantness of mixtures.

Predicting odor pleasantness from odorant structure: pleasantness as a reflection of the physical world.

Although it is agreed that physicochemical features of molecules determine their perceived odor, the rules governing this relationship remain unknown. A significant obstacle to such understanding is the high dimensionality of features describing both percepts and molecules. We applied a statistical method to reduce dimensionality in both odor percepts and physicochemical descriptors for a large set of molecules. We found that the primary axis of perception was odor pleasantness, and critically, that the primary axis of physicochemical properties reflected the primary axis of olfactory perception. This allowed us to predict the pleasantness of novel molecules by their physicochemical properties alone. Olfactory perception is strongly shaped by experience and learning. However, our findings suggest that olfactory pleasantness is also partially innate, corresponding to a natural axis of maximal discriminability among biologically relevant molecules.

A bond-order analysis of the mechanism for hydrated proton mobility in liquid water.

Bond-order analysis is introduced to facilitate the study of cooperative many-molecule effects on proton mobility in liquid water, as simulated using the multistate empirical valence-bond methodology. We calculate the temperature dependence for proton mobility and the total effective bond orders in the first two solvation shells surrounding the H(5)O(2) (+) proton-transferring complex. We find that proton-hopping between adjacent water molecules proceeds via this intermediate, but couples to hydrogen-bond dynamics in larger water clusters than previously anticipated. A two-color classification of these hydrogen bonds leads to an extended mechanism for proton mobility.