Biomedical subjects

W S Cain

Publications and source records attributed to W S Cain.

95 records · Page 6Linked to original sources

PubMedDate not supplied

Clinical evaluation of olfaction.

An odor identification test and an odor threshold test offered satisfactory quantitative information on olfactory function in patients with chemosensory complaints. The threshold test used various concentrations of butanol presented in an ascending sequence. On each trial, the participant had to choose between stimulus and blank (two-alternative forced-choice procedure). The identification test used common odorous items (e.g., baby powder and ground coffee) and pungent items (e.g., ammonia) to test trigeminal function. A list of odor names and use of corrective feedback during testing overcame word-finding difficulty in odor identification. Each test readily distinguished between patients and control subjects. At present, a score that reflects the combined outcome of the tests is used to indicate five categories of functioning: normal osmesis, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia.

Chemoreceptor Cells↗

PubMedDate not supplied

Efficacy of volatile organic compounds in evoking nasal pungency and odor.

Sensory irritation (pungency) figures prominently among the symptoms associated with polluted indoor environments. In order to separate the pungent from the olfactory response, we measured nasal pungency thresholds in subjects lacking olfaction (anosmics) and odor thresholds in normal controls (normosmics) for a homologous series of ketones and for selected secondary and tertiary alcohols and acetates. As seen previously for homologous alcohols and acetates, both types of nasal thresholds decreased with increasing carbon chain length. Pungency thresholds decreased exponentially with chain length. With respect to all nonreactive chemicals studied so far, threshold nasal pungency is achieved at a fairly constant percentage of vapor saturation, irrespective of molecular size or chemical functional group. Such a relationship does not hold for odor thresholds. The outcome for pungency implies an important role for a physical, rather than chemical, interaction with nasal mucosa.

Acetates↗

PubMedDate not supplied

Olfactory functioning and callosotomy: a report of two cases.

Two callosotomy patients with presumably intact anterior commissures were evaluated on a battery of olfactory tasks including sensitivity, discrimination, memory, identification, cross-modality matching, bilateral summation (dirhinic vs. monorhinic thresholds), and localization of odorants. One case was evaluated both pre- and post-surgery. He showed marked decrements after surgery in odor memory and in matching across modalities. After surgery, both patients were better able to name odorants presented to the left nostril than the right nostril. The patient who was asked to remember odorants that could be readily labeled was better able to remember those odorants presented to the left nostril. The findings that both cases performed equally well whether olfactory and tactile information was projected to the same hemisphere or a different one, that some bilateral summation was evident, and that the cases were unable to localize odorants suggests that the remaining neuronal pathways allow for some communication between hemispheres.

Adult↗

PubMedDate not supplied

Sumner's "On testing the sense of smell" revisited.

The routine test of olfaction need not lead to an ambiguous outcome, a rather widely held notion. A multiple-choice test of odor identification that avoided the difficulty of retrieving odor names yielded excellent resolution among the categories normosmic, hyposmic, and anosmic. The outcome agreed almost perfectly with a more complicated test of threshold and offered much encouragement for the use of odor identification in rapid screening of olfaction.

Adolescent↗

PubMedDate not supplied

Irritation and odor as indicators of indoor pollution.

Both irritation and odor figure prominently in complaints about indoor air. Irritation poses the greater problem since it arguably represents an adverse health effect per se and since its sources are often difficult to locate. There exist various potential assays for irritation, some better for validation of symptoms and some better for research on structure-activity relations. One animal assay, the respiratory depression technique, has produced measures of irritant potency in good accord with sensory psychophysical measurements in humans. Both the animal and human data point toward common physicochemical determinants of potency, especially for the weak irritants that often exist in indoor environments. For the foreseeable future, the assessment of odors in indoor environments will need to proceed as in the past, as a psychophysical measurement rather than as a chemical measurement. Methodologies for odor measurement continue to evolve. The evaluation of their usefulness in field settings must ultimately stand against a criterion of validity that has to date proved elusive to establish.

Air Pollution, Indoor↗