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Biomedical subjects

R E Frye

Publications and source records attributed to R E Frye.

9 recordsLinked to original sources

MR hysterosalpingography: protocol development and refinement for simulating normal and abnormal fallopian tube patency--feasibility study with a phantom.

PURPOSE: To develop and refine a pulse sequence and protocol for testing the feasibility of magnetic resonance (MR) hysterosalpingography in a phantom model. MATERIALS AND METHODS: A phantom simulating the uterus, fallopian tubes, and surrounding pelvic cavity was constructed. T2-weighted acquisition strategies-breath-hold fast spin-echo, rapid acquisition with relaxation enhancement (RARE), and haff-Fourier RARE-were refined to acquire sequential 70-mm coronal imaging volumes. Contrast agent was injected into the introducing catheter entering the os of the simulated uterus. Interacquisition interval, type of contrast agent (eg, sterile saline solution or water), and quantity of contrast agent (eg, 1-5 mL per acquisition) were varied. Digital image subtraction was used to enhance image quality. Images were qualitatively analyzed and rated good, fair, or poor for temporal resolution, spatial resolution, fallopian tube conspicuity, and free spill conspicuity. Once the technique was refine, the phantom was reconfigured to simulate unilateral and bilateral hydrosalpinx. RESULTS: The RARE sequence with an 8-second interacquisition interval and a 5-mL interacquisition of sterile water produced good images of the simulated fallopian tubes and free spill. Depiction of unilateral and bilateral hydrosalpinx was also reliably demonstrated. CONCLUSION: This study with a phantom model demonstrates the feasibility of MR hysterosalpingography to depict normal and diseased fallopian tubes.

Constriction, Pathologic↗

Olfactory function in young adolescents with Down's syndrome.

Decreased ability to smell is present in adults with Down's syndrome, many of whom are known to have brain pathology analogous to that seen in Alzheimer's disease. Because olfactory loss is well documented in Alzheimer's disease, the question arises whether young adolescents with Down's syndrome, who have no clear Alzheimer's disease-like neuropathology, also exhibit olfactory dysfunction. To consider this issue, standardised tests of odour discrimination and identification were administered to 20 young adolescents with Down's syndrome (mean age (SD) 13.89 (1.98) years) and their test scores were compared with 20 mentally retarded and 20 non-mentally retarded control subjects matched to the patients with Down's syndrome on the basis of cognitive ability. No significant differences in olfactory function were found among the three study groups. These findings, along with those from studies of olfactory function in older patients with Down's syndrome, suggest that Down's syndrome related olfactory dysfunction occurs only at ages when Alzheimer's disease-like pathology is present.

Adolescent↗

Human odor intensity perception: correlation with frog epithelial adenylate cyclase activity and transepithelial voltage response.

Although a number of odorants are hypothesized to depolarize frog olfactory receptor cells by binding to ciliary glycoproteins which activate membrane-bound G-proteins to induce adenylate cyclase-mediated increases in intracellular cAMP (cyclic adenosine 3',5'-monophosphate), it is not known whether these odorants influence human odor perception via similar mechanisms. In this paper we present evidence derived from odor attribute ranking and multidimensional scaling procedures that the perceived intensity of such odorants to humans is correlated with (a) the amount of adenylate cyclase activity they induce in an in vitro frog olfactory cilia preparation and (b) the magnitude of their influence on the frog transepithelial voltage response or electro-olfactogram (EOG). These observations are in accord with the hypothesis that the perception of the intensity of some odors by humans is associated with cAMP-related epithelial processes and imply that remarkable homologies exist between the intensity-related olfactory receptor mechanisms of frog and man.

Adenylyl Cyclases↗

Dose-related effects of cigarette smoking on olfactory function.

Little is known about the influence of cigarette smoking on the ability to smell; previous studies on this topic have led to contradictory findings and have failed to take into account smoking dose and duration. In the present study, the 40-odorant University of Pennsylvania Smell Identification Test was administered to 638 subjects for whom detailed smoking histories were available. Smoking was found to be adversely associated with odor identification ability in a dose-related manner in both current and previous cigarette smokers. Among previous smokers, improvement in olfactory function was related to the time elapsed since the cessation of smoking. Logistic regression analysis found current smokers to be nearly twice as likely to evidence an olfactory deficit than persons who have never smoked. Overall, the data suggest that (1) smoking causes long-term but reversible adverse effects on the ability to smell and (2) the failure of some studies to demonstrate smoking effects may be caused by the inclusion of persons with a history of smoking in the nonsmoking groups.

Adolescent↗

A comparison of response characteristics of airflow and pressure transducers commonly used in rhinomanometry.

Although the ranges in which pneumotachographs evidence linear output to static flows are documented in the literature, measures of output reliability or the stability of calibration functions resulting from the input of dynamic nonsinusoidal flows (such as those which occur during nasal breathing) have not been investigated. Furthermore, it is not known whether the type of requisite pressure transducer used in conjunction with the pneumotachograph influences the pneumotachograph's linearity, output reliability, or dynamic response. To provide information on these points, we determined the dynamic and static responsiveness of three pneumotachographs commonly used in rhinomanometry, in combination with three requisite pressure transducers. In general, a) output reliability depended on the pneumotachograph/pressure transducer combination and was not readily predictable from the reliabilities of the individual components, b) heating increased pneumotachograph reliability, and c) differences in accuracy existed among transducer combinations at high, but not low, flow frequencies. In addition, results from the calibration syringe study (in which the pneumotachograph is calibrated with dynamic non-sinusoidal flows) suggested that: a) a single calibration factor, as supplied by most pneumotachograph manufacturers, is inadequate for accurately measuring the full range of flows produced in sniffing and breathing tasks; b) the measurement of complex waveforms, even when the dominate frequencies of such waveforms are low, requires pneumotachographs that accurately respond to relatively high frequencies; and c) the use of dynamic nonsinusoidal flows (as opposed to static flows) to calibrate pneumotachographs results in a calibration function with higher reliability.

Calibration↗

Internal consistency reliability of the fractionated and whole University of Pennsylvania Smell Identification Test.

The internal consistency reliability (ICR) of the 40-item University of Pennsylvania Smell Identification Test (UPSIT) and its 10-, 20-, and 30-item fractions was explored, as well as the relationships between the fractions and the entire 40-item test. Pearson correlation coefficients (rs) were computed among all independent combinations and permutations of the four 10-item UPSIT booklets using data from 774 subjects. The median r values of the 10- and 20-item combinations were used to establish the ICRs of the 10- and 20-item tests. The ICRs of the 30- and 40-item tests were estimated using the Spearman-Brown formula and the median rs of the 20-item combinations. Additional ICR estimates of the 40-item UPSIT were obtained from nonsymmetrical fractions using the Horst formula. The ICRs for the UPSIT and its 10-, 20-, and 30-item fractions were 0.922, 0.752, 0.855 and 0.898, respectively. No major sex differences emerged. Estimates of correlations between (1) single booklets and two-booklet combinations and (2) the 40-item UPSIT using Guilford's (1953) correction for nonindependence ranged from 0.812 to 0.871. Overall, these results indicate that (1) the UPSIT and its 10-, 20-, and 30-item fragments have very high ICRs and (2) individual UPSIT booklets or their combinations can be used to assess smell function in a reliable manner where extreme time constraints are present (e.g., in surveys and in brief neuropsychological test batteries).

Adult↗

Olfactory sensitivity, nasal resistance, and autonomic function in patients with multiple chemical sensitivities.

A frequent, if not predominant, complaint of persons reporting symptoms of multiple chemical sensitivities (MCS) is that of heightened sensitivity to smells. In this study odor detection thresholds for phenyl ethyl alcohol (a major component of rose oil) and methyl ethyl ketone (a common solvent) were measured in 18 persons exhibiting symptoms of MCS and in 18 matched normal controls. In addition, nasal resistance, blood pressure, heart rate, and respiration rate were determined before and after the olfactory tests. Scores on the Beck Depression Inventory were obtained prior to testing. Although olfactory thresholds were equivalent in the two study groups, the MCS group evidenced significantly higher nasal resistances, respiration rates and Beck Depression Inventory scores. Decreases in systolic blood pressure and pulse were noted in both groups across the test sessions. These results do not support the hypothesis that MCS is associated with greater olfactory threshold sensitivity (at least to the two target chemicals), but do suggest that MCS is associated with depression, increased respiration rate, and decreased nasal airway patency.

Adult↗

Influence of body tilt within the sagittal plane on odor identification performance.

Odor identification performance, nasal airflow resistance, blood pressure, and heart rate were assessed in 8 men and 8 women in the following body tilt positions within the sagittal plane: 0 degree (upright), 90 degrees (supine), 135 degrees, and 180 degrees (upside down). The order of testing across the tilt conditions was systematically counterbalanced using a Latin square procedure. Average odor identification performance decreased monotonically as a function of increased body tilt. Significant decreases in heart rate and blood pressure were observed as the body was tilted from the upright condition, although blood pressure was equivalent in the upright and upside down conditions. Nasal resistance was highly variable and was not systematically altered as a function of body tilt. These data support the hypothesis that olfactory function, like visual, auditory, and vestibular function, is significantly influenced by body position within a gravitational field.

Adult↗