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Biomedical subjects

W S Cain

Publications and source records attributed to W S Cain.

At least 19 recordsLinked to original sources
PubMed1992

Sensory irritation. Relation to indoor air pollution.

All mucosae of the body possess chemical sensitivity provided by the CCS. Airborne chemicals can stimulate the CCS through the ocular, nasal, and respiratory mucosae, evoking different pungent sensations, for example, stinging, irritation, burning, piquancy, prickling, freshness, and tingling. Pungent sensations elicited in the nose differ from odor sensations in various characteristics. They are achieved at considerably higher concentrations than those necessary to elicit odor, but they increase with the concentration of the stimulus in a steeper fashion than odor. Pungent sensations from mixtures of compounds show a higher degree of addition--relative to the pungency of the individual components--than that of odor sensations. Pungency is more resistant to adaptation than odor, and, unlike it, displays considerable temporal integration with continuous stimulation. Measurement of a reflex, transitory apnea produced upon inhalation of pungent chemicals holds promise as an objective indicator of the functional status of the CCS. Results from the measurement of this reflex have agreed quantitatively with sensory data in a number of studies, and have shown higher common chemical sensitivity in nonsmokers (compared to smokers), in females (compared to males), and in young adults (compared to the elderly). Research issues mentioned here include the following: 1. We can rarely validate the symptoms putatively caused by indoor air pollution objectively. Without such means, we will always have the potential problem of overreporting and embellishment. Although one person may seem more sensitive than another, the difference may lie in a greater proclivity to complain. 2. Studies of anosmic persons offer a simple means to understand the functional characteristics of the nasal CCS. Studies of chemical series in such subjects should eventually allow construction of quantitative structure-activity models for human pungency perception. The human data can be compared with relevant animal data when possible. 3. The rules of additivity of pungency in mixtures need explication. Regarding the possible role of VOCs in the creation of irritation, we need to ask whether subthreshold levels add up or even amplify each other to produce noticeable irritation. Do repetitive or continuous exposures to subthreshold concentrations increase sensitivity to those substances, so that they evoke pungency when they otherwise would not? Do the various mucose--ocular, nasal, throat--differ in their sensitivity? 4. Modulation of CCS sensitivity by long-term and short-term inhalation of various agents (for example, environmental tobacco smoke) would seem a suitable topic for further research.

Adult↗
PubMed1992

Transcatheter embolization of a high-flow congenital intrahepatic arterial-portal venous malformation in an infant.

An intrahepatic arterial-portal venous malformation (APVM) was diagnosed in a 4 1/2-month-old infant with portal hypertension. Visceral angiography showed a large saccular vascular space in the left hepatic lobe with a multiplicity of feeding arteries and drainage into the left portal vein. The lesion was successfully treated by transcatheter embolization following two unsuccessful surgical procedures. Two years later portal vein thrombosis with cavernous transformation was diagnosed, possibly a consequence of the high-flow arterial-portal shunt and its subsequent occlusion. Knowledge of the anatomic differences between this rare congenital APVM and the more commonly occurring arterial-portal fistula is crucial in planning effective transcatheter embolotherapy or surgery for these lesions.

Arteriovenous Fistula↗
PubMed1992

Congenital diaphragmatic hernia in an era of delayed repair after medical and/or extracorporeal membrane oxygenation stabilization: a prognostic and management classification.

In November 1987 we began to practice delayed repair of acutely symptomatic congenital diaphragmatic hernia (CDH) following medical and/or extracorporeal membrane oxygenation (ECMO) stabilization. We reviewed 23 consecutive patients with CDH symptomatic at birth treated over the ensuing 2 1/2 years. The mean age at admission, age at repair, and interval from admission to repair were 4.9, 37.0, and 32.6 hours, respectively. Overall survival was 52% (12/23). ECMO was used in 14 patients with 7 survivors (50%); 4 of these patients underwent repair prior to ECMO and 10 while on ECMO. The patients were retrospectively grouped into three classes based on postductal arterial blood gas (ABG) response to conventional medical management: class A (n = 8), able to achieve and sustain adequate oxygenation (PO2 greater than 60 mm Hg) and hyperventilation (PCO2 less than 40 mm Hg); class B (n = 10), unable to sustain adequate oxygenation (PO2 less than 60 mm Hg) but able to be hyperventilated (PCO2 less than 40 mm Hg); and class C (n = 5), unable to be oxygenated (PO2 less than 60 mm Hg) or hyperventilated (PCO2 greater than 40 mm Hg). The interval from admission to repair was 13.6, 53.5, and 25.4 hours for classes A, B, and C, respectively. Two class A (25%), nine class B (90%), and three class C patients (60%) were placed on ECMO. Survival rates were 88%, 50%, and 0% for classes A, B, and C, respectively. We propose the following management protocol. Class A patients are stable and can be repaired at any convenient point after admission without prerepair ECMO; few will need it afterward.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗
PubMed1992

Olfactory loss and allergic rhinitis.

Olfactory loss is of importance for allergists to investigate in their patients, because if it is due to either allergic rhinitis or nonallergic rhinitis, it is potentially reversible. One should be sure to consider nasal polyposis and inflammation from chronic sinusitis, especially of the ethmoidal sinuses. Simple screening in the office can be achieved with an odor identification test of widely available substances as described above. Should there be no response to treatment or if the patient has a history of chronic sinusitis, recalcitrant nasal polyposis, or previous otolaryngologic procedures, further evaluation including rhinoscopy may be required. Recent olfactory loss in the absence of nasal symptoms and in the absence of abnormalities in the nasal cavity should suggest further investigation to look for a more central process. Morphologic investigation with electron microscopy of the olfactory epithelium and the superior nasal cavity is just beginning. The impact of inflammation in this area awaits investigation.

Adult↗
PubMed1991

Improvement in survival of patients with congenital diaphragmatic hernia utilizing a strategy of delayed repair after medical and/or extracorporeal membrane oxygenation stabilization.

Patients with congenital diaphragmatic hernia (CDH) symptomatic at birth treated at this institution over the past 6 years were reviewed. The patients were divided into two chronological groups for analysis: group 1, consisting of 15 patients treated from January 1984 through October 1987, a period during which acute CDH was considered to be a surgical emergency; and group 2, comprising 20 patients treated from November 1987 through October 1989 using a management protocol of delayed repair following medical and/or extracorporeal membrane oxygenation (ECMO) stabilization. These two groups did not differ significantly in gestational age, birth weight, Apgar scores, hernia side, or age at admission. Group 2 had a longer mean interval from admission to repair (26.5 v 1.8 h, P = .01) and average age at repair (31.0 v 6.5 h, P = .02) than did group 1. Prosthetic closure of the diaphragmatic defect was required more frequently in group 2 then in group 1 (63% v 31%, P = .07). Survival in group 2 was significantly greater than in group 1 (55% v 20%, P = .04). Seven group 2 patients (35%) achieved a prerepair or pre-ECMO PO2 greater than 100 mm Hg and all survived; four of the 13 "nonresponders" also survived. ECMO was used in 11 group 2 patients with five survivors (45%); four of these patients underwent repair prior to ECMO and seven underwent repair while on ECMO.(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal Membrane Oxygenation↗
PubMed1991

Nasal pungency, odor, and eye irritation thresholds for homologous acetates.

We measured detection thresholds for nasal pungency (in anosmics), odor (in normosmics) and eye irritation employing a homologous series of acetates: methyl through octyl acetate, decyl and dodecyl acetate. All anosmics reliably detected the series up to heptyl acetate. Only the anosmics without smell since birth (congenital) reliably detected octyl acetate, and only one congenital anosmic detected decyl and dodecyl acetate. Anosmics who lost smell from head trauma proved to be selectively less sensitive. As expected, odor thresholds lay well below pungency thresholds. Eye irritation thresholds for selected acetates came close to nasal pungency thresholds. All three types of thresholds decreased logarithmically with carbon chain length, as previously seen with homologous alcohols and as seen in narcotic and toxic phenomena. Results imply that nasal pungency for these stimuli rests upon a physical, rather than chemical, interaction with susceptible mucosal structures. When expressed as thermodynamic activity, nasal pungency thresholds remain remarkably constant within and across the homologous series of acetates and alcohols.

Acetates↗
PubMed1991

On the discrimination of missing ingredients: aging and salt flavor.

This study reports on the ability of young, middle-aged, and elderly persons to discriminate the presence-absence of the salt flavoring in a published recipe for a soup. Although all but one young person tested was able to make this discrimination above chance level, more than half of each of the two older groups failed to do so. Both the discrimination score and the absolute threshold for NaCl in water solution correlated significantly with age over a span from 18 to 89 yrs. These results add to previous ones from a similar study of the discrimination of an aromatic spice, marjoram (Cain et al., 1990), in demonstrating that taste and smell weakness revealed in recent psychophysical tests can reveal themselves in the perception of everyday food and beverage preparations. A secondary study compared thresholds for NaCl in water with NaCl thresholds in the presence of tomato, the principal ingredient of the published recipe. These thresholds, presumably because of "mixture suppression" of tastes, were from seven to ten times higher than thresholds in water. Although thresholds for young and old were more alike in the tomato medium than in water, the elderly nevertheless needed over twice as much salt concentration than did the young just barely to appreciate its presence. Computer evaluation of the salt content of a large number of soup recipes revealed that (a) the salt content of the tomato soup we used to study discrimination was reasonably representative of other published recipes for tomato soups and (b) that the salt content of the average of these tomato soup recipes was greater than that of the average of non-tomato soup recipes.

Adult↗
PubMed1991

Olfactory sensitivity: reliability, generality, and association with aging.

Thirty-two Ss between 22 and 59 years of age yielded detection thresholds for 4 odorants over 4 sessions. The thresholds decreased and reliability increased over the course of testing. High intercorrelations between odorants and the stability of an S's relative position within the threshold distributions showed that a general factor of sensitivity dominated the outcome. Age contributed strongly to intersubject variation. Even among these nonelderly individuals, it accounted for up to 2 orders of magnitude in threshold performance. Other important factors included superiority of the right nostril and a negative correlation between the mean and variance of threshold distributions. Scant attention to the correlation may have contributed to overestimation of the frequency and specificity of specific anosmia. A clinically relevant outcome was that measurement of threshold for diagnostic purposes can generally rely on just 1 odorant.

Adult↗
PubMed1991

Remembered odors and mental mixtures: tapping reservoirs of olfactory knowledge.

Five experiments explored how (a) perceived and remembered odor intensities relate to concentration; (b) odor intensities integrate in perceptual, memorial, and mentally constructed mixtures; and (c) components vary in intensity in physical versus mental mixtures. Ss estimated the magnitude of unmixed stimuli presented physically (perceptual estimation) or represented symbolically (memorial estimation). Ss also judged mixtures and their components in combinations of perceptual and memorial presentation. Power functions with similar exponents described the relations between both perceived and remembered intensity and concentration. Perceptual, memorial, and mental mixtures all followed much the same interactive rule of integration. Correspondingly, the intensities of components varied similarly in mentally constructed and physical mixtures. The results imply intensive invariance across odor perception and odor memory.

Adult↗
PubMed1991

Sensory and semantic factors in recognition memory for odors and graphic stimuli: elderly versus young persons.

In four experiments, young (18-26 years, M = 21) and elderly (over 65 years, M = 72) people were compared for recognition memory of (a) graphic stimuli (faces of presidents and vice presidents, engineering symbols, and free forms) and (b) everyday odors. On graphic stimuli, the elderly consistently matched the young, but on odors the performance of the elderly was worse. Their poorer olfactory performance was observed after only 26 s, but became truly marked after 1 hr or more. Somewhere between 1 hr and 2 weeks, their odor performance fell to chance, but their graphic performance remained well above chance. Although the young did forget both graphic and odor materials progressively, their performance always stayed above chance over a 6-month period. Experiments 1 and 2 revealed that the elderly are less sensitive to odors than the young (with thresholds about 10-fold higher), which may explain, in part, their poorer olfactory memory performance. Knowledge that the subjects brought to the tasks by way of familiarity with and ability to name odors and faces played a positive role in recognition memory. Because of this positive role, together with the negative role played by verbal distraction, we conclude that odor recognition memory depends, perhaps heavily, on semantic processing. Impaired semantic processing may result even when odors are simply rendered desaturated, or pastel because of the weakening of olfactory sensitivity with aging.

Adolescent↗
PubMed1990

Thresholds for odor and nasal pungency.

Detection thresholds were measured repeatedly for 11 chemicals in normosmic and anosmic subjects. The stimuli comprised the first eight members of the series of n-aliphatic alcohols, phenyl ethyl alcohol, pyridine, and menthol. Results showed that anosmics could detect, via pungency, all but phenyl ethyl alcohol reliably. In the aliphatic series, both odor and pungency thresholds declined with chain length in a way that implied dependence of both in part on phase distribution in the mucosa. Odor thresholds, however, declined more rapidly than pungency thresholds: the ratio of anosmics threshold/normosmics threshold increased from 23 for methanol to 10,000 for 1-octanol. The outcome of a scaling experiment employing normosmic subjects indicated that, with the exception of methanol and ethanol, pungency arose when perceived intensity reached a narrowly tuned criterion level. When thresholds were expressed as percentages of saturated vapor, an index of thermodynamic activity, thereby accounting for differences in solubility and in phase distribution in the mucosa among the various stimuli, both odor and pungency thresholds depicted a striking constancy across stimuli.

Adult↗
PubMed1979

To know with the nose: keys to odor identification.

Successful odor identification depends on (i) commonly encountered substances, (ii) a long-standing connection between an odor and its name, and (iii) aid in recalling the name. The absence of any one ingredient impairs performance dramatically, but the presence of all three permits ready identification of scores of substances, with performance seemingly limited only by the inherent confusability of the stimuli.

Feedback↗
PubMed1979

Management of localized thoracic neuroblastoma.

Thirteen children with localized (Evans stage I or II) thoracic primary neuroblastoma were divided into two groups according to the type of therapy administered, in order to compare the therapeutic efficacy and morbidity of excisional surgery followed by either irradiation alone or irradiation plus chemotherapy (group A) with similar surgery alone (group B). Group A consisted of 6 children (mean age 1 year, 2 months). Complete surgical excision was accomplished in 2 patients, while 4 had microscopic residual. All 6 patients are free of disease at 26--76 months (mean 47 months), including 2 who had recurrent tumor and received additional therapy. Two have developed congestive heart failure and one severe scoliosis secondary to irradiation. Of the 7 children in group B (mean age 2 years, 2 months), 3 had microscopic residual tumor and 2 had adjacent lymph node involvement. After 12--47 months (mean 23 months), no recurrence or surgery-related morbidity has been observed. From these limited data it appears that surgery alone may provide adequate therapy for localized thoracic neuroblastoma and obviate the morbidity associated with multimodal therapy.

Child, Preschool↗
PubMed1979

Olfactory testing: rules for odor identification.

Neurology manuals generally recommend odor identification for simple assessment of olfaction. Nevertheless, even patients with normal olfaction (normosmics) often perform only poorly. Three experiments demonstrate that such an ambiguous outcome will disappear if the test incorporates highly familiar substances and, more important, a procedure to circumvent the olfactory-verbal gap that frequently separates an odor from its name. One multiple-choice procedure, for instance, led to 100% accuracy among normosmics. Another led to 99% accuracy among normosmics and 0% accuracy among anosmics. The investigation also reveals that scratch-and-sniff labels could possibly replace customary odorants in the clinical test.

Adult↗
PubMed1978

Lability of odor pleasantness: influence of mere exposure.

Subjects judged the pleasantness of various odorants both before and after intensive exposure to a pleasant, a neutral, or an unpleasant odorant, or a short period of relaxation. Intensive exposure comprised a 30 min task of intensity discrimination. The outcome implied that exposure to an odorant can modify its own pleasantness readily, but not so readily that of other odorants. Exposure to the pleasant lemon-smelling substance citral reduced its subsequent pleasantness, whereas exposure to the unpleasant rancid-smelling substance isobutyric acid reduced its subsequent unpleasantness. The results were compatible with the notion of affective habituation. Variability of the pleasantness judgments was uniform throughout the hedonic continuum. That is, subjects agreed as much about hedonically neutral odors as about extremely pleasant and unpleasant odors.

Affect↗
PubMed1977

Differential sensitivity for smell: "noise" at the nose.

The ability of subjects to resolve differences in concentration of chemicals in the vapor phase by smell rivaled the optimum performance of chromatographs. In some instances, subjects resolved a difference in concentration of only 5 percent. The reported inability of olfaction to register fine differences in intensity seems to be largely a result of fluctuations in the stimulus.

Alcohols↗