Self-reported occupational dermatological reactions among Danish dentists.

The aims of the study were to investigate the causes and prevalences of occupational dermatological reactions among Danish dentists. Questionnaires and telephone interviews with Danish dentists revealed that 37.8% reported skin reactions. In 27.2% of the cases the reactions were related to occupation, occurring with a point prevalence of 9.6%, and with a 1-yr period prevalence of 21.4%. The main causes were hand washing/soaps, latex gloves and (di)methacrylate-containing materials occurring at point prevalences of 7.1%, 1.3% and 1.7%, respectively. In addition, several other causes were reported, each occurring at relatively low frequency. Diagnosed allergic latex eczema was reported by 0.6%, but the frequency might be more than 2%, estimated on basis of reported symptoms. Allergic eczema caused by (di)methacrylate-containing materials was diagnosed among 0.7%, but estimated by the description of symptoms to be nearly 2%. The results urge for developing safer materials for dental use.

Odor memory: Review and analysis.

We critically review the cognitive literature on olfactory memory and identify the similarities and differences between odor memory and visual-verbal memory. We then analyze this literature using criteria from a multiple memory systems approach to determine whether olfactory memory can be considered to be a separate memory system. We conclude that olfactory memory has a variety of important distinguishing characteristics, but that more data are needed to confer this distinction. We suggest methods for the study of olfactory memory that should make a resolution on the separate memory system hypothesis possible while simultaneously advancing a synthetic understanding of olfaction and cognition.

A comparison of self-adaptation and cross-adaptation to odorants presented singly and in mixtures.

Fifteen subjects made 450 judgments each by the method of magnitude estimation of dimethyl disulfide and hydrogen sulfide after prior exposure to various mixtures of them. Exposure to the same odorant clearly affected the perceived intensity of it (self-adaptation). By contrast, exposure to the other odorant showed at best a small effect (cross-adaptation). Consistent with this, adaptation to a mixture of the test odorant and another odorant is proportional to the amount of the test odorant in the mixture, and does not exceed that of self-adaptation. These results indicate that olfactory adaptation is specific and that the sense of smell is more robust than generally assumed.

Lightweight modular orthosis.

Background and highlights are presented concerning the development of a new orthotic system judged to be "the most outstanding innovation in prosthetics and/or orthotics practice" during the 1986-1989 period. The first Brian Blatchford Prize was awarded at the Sixth World Congress of ISPO held in Kobe, Japan. November 12-17, 1989. The new development selected as most deserving of this award consists of a system utilizing inexpensive, lightweight, modular components which can be quickly assembled with a few hand tools to provide custom-fitted knee-ankle-foot orthoses for persons with paraplegia and quadriplegia. These leg frames support standing and permit the patient to begin receiving the physical and psychological benefits of weightbearing as soon as medically feasible after injury. Later, if desired, specially designed knee-joints, with a variety of possible locking features, can be installed on the existing leg frames at a reasonable cost.

A comparison of odor perception in smokers, nonsmokers, and passive smokers.

The olfactory perception in matched groups of 26 smokers, 26 nonsmokers, and 15 passive smokers was examined psychophysically with two substances, n-butane and pyridine. Different psychophysical functions were obtained from these groups using the method of magnitude estimation. The smokers and passive smokers perceived all concentrations of n-butane to be weaker than did the nonsmokers. In the case of pyridine, a substance in tobacco smoke to which smokers are more exposed, there is an indication of a perceptual deficit similar to loudness recruitment. There were no appreciable differences between smokers and nonsmokers for high concentrations; the sensitivity was less and the psychophysical functions steeper for smokers than nonsmokers for relatively low concentrations. The results are evaluated in terms of information about the subjects' response criteria, and the authors consider the possibility of sensory deficit versus habituation.

The human uses of olfaction.

The sense of smell may be important as an arousal system that calls attention to significant environmental events, air quality, and food. Humans share with animals an ability to store odor memories. The consequences of these memories include odor preferences and food aversions. Olfactory pheromones involved in sexual behavior have been observed in animals, but their existence in humans has not been proved.

Odor discrimination and memory in Korsakoff's psychosis.

Korsakoff's syndrome is an organic brain disease, characterized by severe amnesia, that has been associated with olfactory perceptual deficits. Two experiments utilized normal observers to describe the effect of similarity on odor recognition memory and to develop methodology to measure odor discrimination and memory in patients with Korsakoff's disease. The results demonstrate an impaired capacity to discriminate between odors among patients with this disease that is not attributable to impaired sensitivity or to rapid decay of memory stores. These results are compared with results from animals with lesions affecting the medial layer of the mediodorsal thalamic nucleus and its neocortical projections. This structure is consistently damaged in Korsakoff's disease and receives a major input from primary olfactory cortex.

Olfactory sensitivity during the menstrual cycle.

Women were tested for sensitivity to several odorants at ovulation and menstruation. Three involatile esters (pentadecalactone, coumarin, and cinnamyl butyrate) predicted by gas chromatographic data to be strongly retarded by the olfactory mucus showed similar significant changes in sensitivity. By contrast, a more volatile ester (amyl acetate) predicted to diffuse more readily though the mucus showed no such changes. This suggests that variations in olfactory sensitivity observed between ovulation and menstruation depend on odorant volatility and thus may result from peripheral mechanisms limiting the access of odorant molecules to the olfactory receptors.

Associations to odors: interference, mnemonics, and verbal labeling.

In a paired-associate paradigm using odors as stimuli and pictures for multiple-choice responses, the first of two associations to an odor was retained far better than the second over a 2-week period. The persistence of first-learned associations may be responsible for the long lasting nature of odor memories. Subjects reported constructing mediational schemes for mnemonic devices to link the odors and pictures. Latencies for a task of naming odors indicated that although naming odors is difficult, labels could be generated sufficiently fast that they could be employed as mediators in the paired-associate task. A third task investigated the phenomenon of knowing that an odor was familiar but being unable to name it. Subjects in this tip-of-the-nose state were questioned about the odor quality and the name of the odor and were given hints about the name. These subjects were found to have information available about the odor quality but none for the name as found in the tip-of-the-tongue state. However, as in the tip-of-the-tongue phenomenon, hints given to the subjects in the tip-of-the-nose state often led to the correct name.

Some effects of aphasic lesions on order perception.

Twenty-four aphasic, nine brain-damaged, and eight non-brain-damaged patients were tested for their ability to associate odors with visual targets. The results of the experiment show that lesions producing aphasia interfere with the ability to match an odor to a directly corresponding visual target. As aphasics with anterior and posterior lesions performed at similar levels in this task, it was not possible to conclude that the observed deficits were specifically related to temporal lobe functions. The severity of the deficit was greater for more massively lesioned aphasics. The exact nature of the deficit was not clear, but review of the literature and differential results obtained for the two experimental tasks suggest that aphasic lesions may interefere with odor identification.