Paul R. Sheehe

Olfactory performance during childhood. II. Developing a discrimination task for children

OBJECTIVES (1) To create a match-to-sample odorant discrimination task (MODT) for children and adolescents; (2) to assess whether nonolfactory factors affect olfactory performance more on an identification task than on the MODT; (3) to evaluate subjects with olfactory dysfunction; and (4) to create age-appropriate sets of odorants for use in the MODT format to test children of different ages. STUDY DESIGN We tested 75 normal children, aged 2 to 18 years, and 17 other subjects, aged 7 to 53 years, with known or suspected olfactory dysfunction, with the MODT. We compared the age trends in variability of scores on the MODT with those on an odorant identification task, using a weighted linear regression analysis. RESULTS The MODT was useful in children aged 5 years and older, but not generally in the 2- to 4-year-old children. There was an appreciable age trend in the variability of the scores on the identification task but not on the MODT. Mean MODT scores for subjects with suspected or known olfactory dysfunction were far below average. Finally, we created four sets of odorants that will likely be sensitive to age-specific changes in olfactory performance. CONCLUSIONS The MODT appears to be a suitable test instrument to assess olfaction in children aged 5 and older and is less likely to be influenced by nonolfactory factors than an identification task. According to our preliminary results, it is likely that the MODT will allow us to detect olfactory deficits in children of many ages.

Phonological and perceptual components of short-term memory for odors.

Just as a written word can be encoded and retained in memory verbally or visually, an odor might be retained as a verbal description or perceptual (olfactory) code. However, one view holds that olfactory memory in the short term does not exist as a separate perceptual code. This was examined in an experiment in which memory errors could be seen as deriving from the substitution of similar verbal or olfactory codes. The odorants presented for recall were divided into three groups: base odorants (which might be replaced in memory by similar verbal or olfactory representations), verbal foils (stimuli dissimilar to the base stimuli in odor but similar in name), and odor foils (the reverse). The substitution errors made in attempting to recall test odorants were classified as verbal or olfactory. A substantial proportion of the errors were olfactory, but verbal errors also occurred. These results support the presence of short-term perceptual olfactory memory rather than simply verbal encoding of olfactory perceptions.

Cuff and aortic pressure differences during dobutamine infusion: A study of the effects of systolic blood pressure amplification

BACKGROUND Central aortic systolic blood pressures (SBPs) differ from and are preferable to cuff pressures when calculating cardiac work, left ventricular wall stress, and rate-pressure product. Despite the widespread use of dobutamine, differences between aortic and brachial SBP (pulse amplification) and pulse transmission during dobutamine infusion have not been previously studied. This study assessed these differences and used applanated radial pulses with the Sphygmocor (AtCor Medical, Sydney, Australia) device to investigate the effects of dobutamine on arterial pulse transmission and pulse amplification. METHODS Using a cuff oscillometer, brachial arterial pressures were measured simultaneously with directly recorded aortic pressures at rest and during increasing dobutamine infusion rates in 25 patients. In 15 of those patients, applanated radial pulses were fed into the Sphygmocor device and calibrated in 2 ways to predict aortic pressures. RESULTS At peak dobutamine infusion, SBP amplification averaged 14.9 mm Hg, with a maximum difference of 43 mm Hg. When radial artery pulses were calibrated using cuff pressures, the Sphygmocor underestimated the aortic SBP at all dobutamine doses. However, when radial artery pulses were calibrated using the more accurate aortic mean and diastolic BPs, the Sphygmocor accurately predicted the aortic SBP at baseline, but not at the higher dobutamine doses. CONCLUSIONS Similar to exercise, dobutamine induced cuff SBPs and pulse pressures higher than those measured in the aorta-uncorrected by the cuff-calibrated Sphygmocor. This increasing pulse amplification was explained by the effects of dobutamine on the properties of the conduit arterial walls, on changes in pulse wave velocity, on increasing heart rate, and on reflected waves.

The consequence of fetal ethanol exposure and adolescent odor re-exposure on the response to ethanol odor in adolescent and adult rats

BackgroundAn epidemiologic predictive relationship exists between fetal ethanol exposure and the likelihood for adolescent use. Further, an inverse relationship exists between the age of first experience and the probability of adult abuse. Whether and how the combined effects of prenatal and adolescent ethanol experiences contribute to this progressive pattern remains unknown. Fetal ethanol exposure directly changes the odor attributes of ethanol important for both ethanol odor preference behavior and ethanol flavor perception. These effects persist only to adolescence. Here we tested whether adolescent ethanol odor re-exposure: (Experiment 1) augments the fetal effect on the adolescent behavioral response to ethanol odor; and/or (Experiment 2) perpetuates previously observed adolescent behavioral and neurophysiological responses into adulthood.MethodsPregnant rats received either an ethanol or control liquid diet. Progeny (observers) experienced ethanol odor in adolescence via social interaction with a peer (demonstrators) that received an intragastric infusion of either 1.5 g/kg ethanol or water. Social interactions were scored for the frequency that observers followed their demonstrator. Whole-body plethysmography evaluated the unconditioned behavioral response of observers to ethanol odor in adolescence (P37) or adulthood (P90). The olfactory epithelium of adults was also examined for its neural response to five odorants, including ethanol.ResultsExperiment 1: Relative to fetal or adolescent exposure alone, adolescent re-exposure enhanced the behavioral response to ethanol odor in P37 animals. Compared to animals with no ethanol experience, rats receiving a single experience (fetal or adolescent) show an enhanced, yet equivalent, ethanol odor response. Fetal ethanol experience also increased olfactory-guided following of an intoxicated peer. Experiment 2: Combined exposure yielded persistence of the behavioral effects only in adult females. We found no evidence for persistence of neurophysiological effects in either sex.ConclusionFetal ethanol exposure influences adolescent re-exposure, in part, by promoting interactions with intoxicated peers. Re-exposure subsequently enhances ethanol odor responsivity during a key developmental transition point for emergent abuse patterns. While persistence of behavioral effects occurred in females, the level of re-exposure necessary to uniformly yield persistence in both sexes remains unknown. Nonetheless, these results highlight an important relationship between fetal and adolescent experiences that appears essential to the progressive pattern of developing ethanol abuse.

Chemotherapy of the leukemic transformation of lymphosarcoma.

The chemotherapy of leukemic transformation of lymphosarcoma has been studied in seventeen children. Complete hematologic remission was obtained in 88 per cent treated with 6-mercaptopurine and prednisone. Maintenance therapy with 6-mercaptopurine was employed and the median duration of remission was 21 weeks. These results are comparable to those obtained in a series of children with acute lymphocytic leukemia in which the remission rate was 82 per cent and median duration of remissoin was 33 weeks with the same therapy.

A variable risk clinical prognostic compartmental model

A model for predicting the occurrence of disease endpoints from a knowledge of baseline variables and intermediate events is described and illustrated with numerical examples. Maximum likelihood equations are developed and maximum likelihood estimates of coefficients in risk functions of variables included in a stepwise upward procedure are applied to a small set of data for illustrative purposes.