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PubMed2000

Assessment of smell and taste in patients with allergic rhinitis.

We examined the senses of smell and taste in 240 patients with verified hypersensitivity reactions of the respiratory tract. Olfactometry was performed according to Elsberg and Levy's method and followed by electrogustometry. The examinations revealed that the incidence of smell and taste disorders in patients with allergic rhinitis is 21.4% and 31.2%, respectively. No significant relationships between smell and taste dysfunction were found. We evaluated statistically positive correlations between the olfactory and gustatory thresholds compared with 78 qualitative and quantitative factors assessed in the study. There was a statistically significant relationship between the olfactory thresholds and levels of eosinophils in blood and in nasal discharge. acid reaction of the nasal mucosa, coexisting nasal polyps and X-ray changes in the ethmoid sinuses. There was a positive influence of pharmacotherapy as well as specific desensitization and surgery on the impairment of the sense of smell in allergic rhinitis.

Adolescent↗
PubMed2005

Effect of soybean fortification on Ghanaian fermented maize dough aroma.

The effect of soy fortification on the development of aroma compounds, dough acidity and growth of the predominant microorganisms were investigated in Ghanaian maize dough fermented spontaneously over a period of 72 h. The fortified maize dough was prepared from a milled mixture of soaked maize grains and pre-soaked, blanched and dehulled soybeans added at 20% replacement level. Extracts of volatiles from the soy-fortified and unfortified dough samples were obtained by Likens-Nickerson simultaneous distillation and extraction method analysed by gas chromatography-mass spectrometry and gas chromatography-olfactometry (gas chromatography-sniffing). Major aroma compound groups identified in the fermented dough samples were carbonyls, alcohols, esters and volatile organic acids. Twenty-nine carbonyls were found in soy-fortified maize dough compared with 21 in the unfortified dough. Although the same alcohols were found in both dough samples, the total concentration of alcohols was slightly different, being less for the soy-fortified sample. Total concentration of esters in soy-fortified dough decreased after 72 h while levels in the unfortified dough increased. Increases in the production of lactic and acetic acids occurred in soy-fortified samples, but the maximum concentrations of acetic acid achieved did not differ significantly between the two types of dough. Twenty-three compounds were perceived to be contributing to the typical aroma of soy-fortified maize dough by the method of gas chromatography-sniffing. These included 12 carbonyls, six alcohols, two esters, two acids and one furan.

Acetic Acid↗
PubMed2003

No influence of scopolamine hydrobromide on odor detection performance of rats.

Despite speculation that the muscarinic cholinergic antagonist, scopolamine, may influence the olfactory sensitivity of rats, there have been no definitive studies on this point to date. In this study, we examined the influence of a range of doses of scopolamine hydrobromine (namely, 0.10, 0.125, 0.15 and 0.20 mg/kg i.p.) on the odor detection performance of 15 adult male Long-Evans rats to ethyl acetate. Air-dilution olfactometry and a go/no-go operant signal detection task were employed. The drug conditions and a saline control were administered to each animal in an order counterbalanced by Latin squares, with 2 day intervals interspersed between tests. Scopolamine had no significant influence on odor detection performance per se, as measured by percent correct S+ and S- responses and a non-parametric signal detection measure of sensitivity. This is in contrast to the relatively large effects previously observed in the same test paradigm for such drugs as the D-1 agonist SKF 38393 and the D-2 agonist quinpirole. These data suggest that scopolamine has no meaningful influence on a well-practiced odor detection task.

Aging↗
PubMed2004

Hemodynamic response of the frontal cortex elicited by intravenous thiamine propyldisulphide administration.

The intravenous olfaction (IVO) test is a unique type of clinical olfactometry and is widely used in Japan. However, it is difficult to distinguish actual olfactory disturbance from feigned disturbance because the IVO test is a psychophysical test. To resolve this problem, we investigated the possibility of an objective IVO test assisted with near infrared spectroscopy (NIRS). IVO testing was performed according to the usual protocol with thiamine propyldisulphide (alinamin) administration. The relative oxy- and deoxyhemoglobin levels of the orbitofrontal area during olfactory stimulation by IVO test were measured by NIRS. Pairs of NIRS emitters and detectors were positioned on the bilateral frontal scalp. After administration of alinamin, oxyhemoglobin levels increased, though deoxyhemoglobin levels did not change. An increase in oxyhemoglobin levels was observed bilaterally. Administration of saline did not elicit any change in the oxy- or deoxyhemoglobin levels and concentration of the administered alinamin related increasing of the oxyhemoglobin level was observed. Oxyhemoglobin remained unchanged in anosmic subjects despite administration of alinamin. The latency of oxyhemoglobin increase on each side and smelling latency showed significant correlation. Latencies of oxyhemoglobin increases between the right and left sides also showed significant correlation. Oxyhemoglobin response appears to be linked to olfactory related response. NIRS is a useful technique for the development of an objective form of IVO testing.

Adult↗
PubMed2005

Evaluation of the validity of a maximum likelihood adaptive staircase procedure for measurement of olfactory detection threshold in mice.

Threshold is defined as the stimulus intensity necessary for a subject to reach a specified percent correct on a detection test. MLPEST (maximum likelihood parameter estimation by sequential testing) is a method that is able to determine threshold accurately and more rapidly than many other methods. Originally developed for human auditory and visual tasks, it has been adapted for human olfactory and gustatory tests. In order to utilize this technique for olfactory testing in mice, we have adapted MLPEST methodology for use with computerized olfactometry as a tool to estimate odor detection thresholds. Here we present Monte Carlo simulations and operant conditioning data that demonstrate the potential utility of this technique in mice, we explore the ramifications of altering MLPEST test parameters on performance, and we discuss the advantages and disadvantages of using MLPEST compared to other methods for the estimation of thresholds in rodents. Using MLPEST, we find that olfactory detection thresholds in mice deficient for the cyclic nucleotide-gated channel subunit A2 are similar to those of wild-type animals for odorants the knockout animals are able to detect.

Animals↗
PubMed2001

A prospective study evidencing rhinomanometric and olfactometric outcomes in women taking oral contraceptives.

BACKGROUND: The aim of this prospective study was to evaluate the changes in olfactory sensitivity of oral contraceptive (pill) users. METHODS: Sixty women underwent rhinomanometric and olfactometric determinations during the follicular, periovular and luteal phases of the menstrual cycle, and at day 7, 14 and 21 of contraceptive intake. Thirty-one women used 30 microg ethinyl oestradiol plus 75 microg gestodene and 29 women used 20 microg ethinyl oestradiol plus 150 microg desogestrel. RESULTS: Rhinomanometry showed higher but not statistically significant values during the periovular phase than in the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular and periovular phases than during the luteal phase of the menstrual cycle. The rhinomanometric surveys in pill users were statistically different from those of the luteal phase (P < 0.02) and the follicular and periovular phases (P < 0.001). The olfactometric thresholds during the period of contraceptive use were statistically different from those of the follicular phase for a few odorous substances, and from those of the periovular phase for each odorous substance, but similar to those of the luteal phase (P = NS). CONCLUSIONS: Unlike the rhinomanometric airflow and trans-nasal pressure, the olfactory threshold to odours seems to depend on the variations of the ovarian steroids during the menstrual cycle and on the iatrogenic effects of oral contraceptives.

Adolescent↗
PubMed1993

Kinetics of male pheromone production by Amblyomma variegatum (Acari: Ixodidae).

Males of Amblyomma variegatum (F.), when attached on their host, produce a pheromonal blend composed of methyl salicylate, ortho-nitrophenol, and nonanoic acid, which acts as an aggregation-attachment pheromone. Using olfactometry assays, assays on hosts, and quantification of the compounds by capillary gas chromatography, the kinetics of pheromone production has been studied. Males engorged for at least 10 d elicit attachment from most of the tested females. Attractiveness of males for females is significant only between days 14 and 23 of engorgement. Before 10 d of attachment, the amounts of pheromones detected in hexanic male body extracts are very low (< 10 ng); they then increase to a maximum of 2 micrograms for the major compound per male. Large amounts can be detected until 80 d of engorgement. The inter-individual variation is very large throughout the engorgement period. The interest and the limitations of the different techniques used are discussed.

Animals↗
PubMed1999

Preservation of the olfactory tract in bifrontal craniotomy for various lesions of the anterior cranial fossa.

OBJECTIVE: Preservation of the olfactory tract during use of the bifrontal approach for the treatment of lesions located in the frontal cranial base and the supra- and parasellar regions has not been previously investigated. METHODS: In our study, 12 patients underwent surgery, via the basal subfrontal route, for treatment of various lesions. All patients were observed prospectively, and olfactometry was performed pre- and postoperatively by an independent otorhinolaryngologist. RESULTS: We obtained complete preservation of the olfactory tracts and normal postoperative olfaction in all 12 cases. CONCLUSION: The bifrontal approach yields a bilateral wide operative field with excellent orientation and views of important structures. The shortcomings of this method, i.e., damage to the olfactory tracts and postoperative anosmia, can be overcome.

Adolescent↗
PubMed2005

Congenital arhinia: a case report and functional evaluation.

OBJECTIVES: Congenital arhinia is rare clinical entity. An unusual case of congenital arhinia with no surgical treatment is presented. STUDY DESIGN: Case report. METHODS: A 9-year-old with congenital arhinia was referred for treatment of otitis media with effusion. In addition to his undergoing imaging studies since birth, various functional evaluations regarding the nose were performed. Furthermore, the pathogenesis of arhinia is discussed. RESULTS: The imaging workup revealed the absence of nasal bones, the nasal septum, and turbinates, hypoxia of the maxilla, and a high-arched palate. Furthermore, magnetic resonance imaging clearly demonstrated the absence of olfactory bulbs and tracts, resulting in no response with olfactometry. Among the examinations performed, chromosomal analysis, polysomnography, and an intelligence test produced normal results. In the hearing assessment, he had a slight conductive hearing loss. A phonetic examination revealed the typical pattern of rhinophonia clausa. CONCLUSIONS: This study presents congenital arhinia associated with facial anomalies. Because there was no life-threatening complications and normal psychomotor development, the patient could not only be followed up long-term but could also have his nose functionally evaluated. It is highly likely that this case might have been the result of the failure of medial and lateral nasal processes to grow, which was the underlying pathogenesis.

Child↗
PubMedDate not supplied

Chemosensory function in patients with vagal nerve stimulators.

Chemosensory function is determined by the interplay of numerous sensory modalities. The present study aimed to evaluate the possible influence of electrical stimulation of the left-sided vagal nerve on gustatory and olfactory function in patients with vagal nerve stimulation (VNS). Gustation and olfaction were tested using psychophysical techniques; olfactory function was additionally evaluated using event-related potentials. A total of 11 subjects participated (six men and five women, aged 21 to 56 years). The vagal stimulator was run in "rapid cycle mode" in 10 patients, whereas one patient was treated with "normal mode" VNS. Subjects participated in two sessions, with the vagal stimulator switched on and off, respectively. The sequence of the two sessions was randomized across all participants. Using air-dilution, olfactometry event-related potentials to the specific olfactory stimulant H2S were recorded. Psychophysical tests were performed using the "Sniffin' Sticks" test kit, a test for retronasal olfactory function, and a gustatory test based on impregnated filter paper. The study yielded the following major results: (1) VNS produced a prolongation of P2 latencies of olfactory ERP, and (2) patients with therapeutic benefit from VNS in terms of seizure control had larger amplitudes during the on period than during the off period. In conclusion, using electrophysiological measures of olfactory function, the present study indicated a significant role of VNS in the processing of olfactory information.

Adult↗
PubMed2005

Main compounds responsible for off-odour of strawberries infected by Phytophthora cactorum.

AIMS: Volatile compounds present in strawberries infected with Phytophthora cactorum, especially those responsible for the characteristic off-odour of such fruits were the subject of this study. METHODS AND RESULTS: Six strawberry varieties (Redgauntlet, Selva, Korona, Tenira, Real, Pegasus) inoculated with P. cactorum strain (PC-5), isolated from naturally infected fruit and one variety inoculated with 15 strains of P. cactorum in the laboratory were analysed. All the samples had a distinct, to a various degree, off-odour reminiscent of watercolour paint with phenolic notes. Volatile compounds were isolated by solid phase microextraction and simultaneous distillation extraction methods. To detect compounds responsible for the characteristic off-odour, gas chromatography-olfactometry was used. Two compounds were found to be responsible for the characteristic off-odour of strawberries infected by P. cactorum: 4-ethyl phenol and 4-ethyl-2-metoxy phenol (4-ethyl guaiacol). The content of these compounds in infected varieties ranged from 1.12 to 22.56 mg kg(-1) and 0.14-1.05 mg kg(-1) respectively. Other volatile compounds, not detected in noninoculated sound strawberries, were also identified: camphene, 1-octene-3-ol, 3-octanone, o-cymene, phenyl methanol, cis-linaloloxide, nonanal, phenyl ethyl alcohol, 2-undecanone and alpha-muurolene. SIGNIFICANCE AND IMPACT OF THE STUDY: Volatile compounds responsible for the characteristic off-odour of strawberries infected with P. cactorum were identified. Also compounds produced as a result of P. cactorum growth on strawberry fruit were characterized.

Aldehydes↗
PubMed2006

Microbial diversity associated with odor modification for production of fertilizers from chicken litter.

Litter from the chicken industry can present several environmental challenges, including offensive odors and runoff into waterways leading to eutrophication. An economically viable solution to the disposal of waste from chicken houses is treatment to produce a natural, granulated fertilizer that can be commercially marketed for garden and commercial use. Odor of the final product is important in consumer acceptance, and an earthy odor is desirable. By understanding and manipulating the microbial processes occurring during this process, it may be possible to modify the odors produced. Geosmin and related volatiles produced by soil actinomycetes are responsible for earthy odors, and actinomycetes are likely to be present in the composting manure. Bacterial communities at each stage of the process were analyzed by culturing studies and denaturing gradient gel electrophoresis (DGGE). The processing steps changed the culturable bacterial community, but the total community was shown by DGGE to be stable throughout the process. A local agricultural soil was analyzed in parallel as a potential source of geosmin-producing actinomycetes. This agricultural soil had higher microbial diversity than the compost at both the culturable and the molecular levels. Actinomycete bacteria were isolated and analyzed by AromaTrax, a gas chromatography-olfactometry system. This system enables the odor production of individual isolates to be monitored, allowing for rational selection of strains for augmentation experiments to improve the odor of the final fertilizer product.

Animals↗
PubMed2003

Rapid olfactory processing implicates subcortical control of an olfactomotor system.

Sniffs are modulated in response to odor content. Higher concentrations of odor induce lesser-volume sniffs. This phenomenon implicates a neural feedback mechanism that measures sensory input (odor concentration) and modulates motor output (sniffing) accordingly. Here we used air-dilution olfactometry to probe the time course of this olfactomotor mechanism. A stainless-steel computer-controlled olfactometer, equipped with mass flow controllers, temperature and humidity control, and on-line photo-ionization detection, was coupled to a highly sensitive pneumatotachograph that measured nasal flow. The olfactometer was used to generate four ascending concentrations of the odorants propionic acid and phenethyl alcohol. Sniff volume was inversely related to odor concentration (P > 0.0001). Sniffs were uniform and concentration independent for the initial 150 ms but acquired a concentration-dependent flowrate as early as 160 ms following sniff onset for propionic acid (P > 0.05) and 260 ms for phenethyl alcohol (P > 0.05). Considering that odorant transduction takes around 150 ms and odorant-induced cortical evoked potentials have latencies of around 300 ms, the rapid motor adjustments measured here suggest that olfactomotor sniff feedback control is subcortical and may rely on neural mechanisms similar to those that modulate eye movements to accommodate vision and ear movements to accommodate audition.

Adult↗
PubMed1991

Olfactory dysfunction in Parkinson's disease.

An olfactory function test in 18 patients with Parkinson's disease (PD) and 10 age-matched control subjects was performed. Both detection and recognition thresholds were measured with five kinds of synthesized odorants (T & T olfactometry). Before each test, rhinoscopic inspections were performed to exclude subjects who could have respiratory hyposmia. Both detection and recognition thresholds in patients with PD were significantly elevated in comparison with those of control subjects. Auditory acuity of PD patients, however, was well preserved and there was no significant correlation between auditory and olfactory threshold. On the basis of the present study, the authors conclude that olfactory dysfunction is one of the characteristic symptoms of PD and it may be attributed to lesions in the olfactory neural pathway including olfactory neuroepithelium.

Adult↗
PubMed2001

Rhinomanometric and olfactometric variations throughout the menstrual cycle.

A prospective study was performed to evaluate the rhinomanometric values and the changes in the olfactory threshold that occur in women throughout the menstrual cycle. The subjects were 60 healthy volunteer premenopausal women 18 to 40 years of age. We performed rhinomanometric and olfactometric measurements during the follicular, periovular, and luteal phases of the menstrual cycle. Rhinomanometry showed a higher (not statistically significant) airflow during the periovular phase than during the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular phase (p < .05) and the periovular phase (p < .001) than during the luteal phase. We conclude that airflow and transnasal pressure during spontaneous respiration, as well as the olfactory threshold to odors, seem to depend on the variations of the ovarian steroids that occur during the menstrual cycle.

Adolescent↗
PubMed2003

X chromosome-linked Kallmann syndrome: clinical heterogeneity in three siblings carrying an intragenic deletion of the KAL-1 gene.

Kallmann syndrome (KS) is characterized by the association of hypogonadotropic hypogonadism and anosmia. The gene underlying the X chromosome-linked form of the disease, KAL-1, consists of 14 coding exons. It encodes a glycoprotein, anosmin-1, which is involved in the embryonic migration of GnRH-synthesizing neurons and the differentiation of the olfactory bulbs. We describe herein the clinical heterogeneity in three affected brothers who carry a large deletion (exons 3-13) in KAL-1. All three had a history of hypogonadotropic hypogonadism with delayed puberty. Although brain magnetic resonance imaging showed hypoplastic olfactory bulbs in the three siblings, variable degrees of anosmia/hyposmia were shown by olfactometry. In addition, these brothers had different phenotypic anomalies, i.e. unilateral renal aplasia (siblings B and C), high-arched palate (sibling A), brachymetacarpia (sibling A), mirror movements (siblings A and B), and abnormal eye movements (sibling C). Last but not least, sibling A suffered from a severe congenital hearing impairment, a feature that had been reported in KS but had not yet been ascribed unambiguously to the X-linked form of the disease. The variable phenotype, both qualitatively and quantitatively, in this family further emphasizes the role of putative modifier genes, and/or epigenetic factors, in the expressivity of the X-linked KS.

Adolescent↗
PubMed2004

Olfaction in olfactory bulbectomized rats.

Experimental rats had their right olfactory bulb removed on postnatal day 2 (P2) and their left olfactory bulb removed on P90. Control rats had one or both olfactory bulbs removed on P90. Before and after their adult-stage surgery, rats were trained using olfactometry and operant conditioning to detect and discriminate odors. Anterograde transport of horseradish peroxidase applied to the olfactory epithelium revealed numerous axons of olfactory sensory neurons in the right hemisphere of 27 experimental rats. These axons terminated in glomerular-like clusters within the frontal neocortex (n = 5) or anterior olfactory nucleus with some axons extending into the subventricular epithelium (n = 22). Seventeen of the experimental rats were able to detect a variety of odors and to discriminate between odors. Performance accuracy was related to the location and density of these anomalous inputs; experimental rats with inputs confined to frontal neocortex and those lacking any inputs to the forebrain were anosmic, as were adult-operated bilaterally bulbectomized rats. Our results provide strong support for the contention that, in the absence of the olfactory bulbs, olfactory connections to novel forebrain sites can support both odor detection and odor discrimination.

Animals↗
PubMedDate not supplied

Olfactory response to mushroom composting emissions as a function of chemical concentration.

Odor pollution is a major problem facing mushroom [Agaricus bisporus (Lange) Imbach] compost production. Techniques for quantifying mushroom composting odors are needed to assess the effectiveness of odor control measures. Odor samples were obtained in nalophane bags from 11 mushroom composting sites. Samples were collected 0.2 m downwind from the pre-wetting heaps (aerated or unaerated) of raw composting ingredients (wheat straw, poultry and horse manures, and gypsum) and subsequent Phase I composting windrows or aerated tunnels. The odor concentrations (OCs) of the samples were assessed using serial dilution olfactometry and the chemical composition of the samples was determined using gas chromatography-mass spectrometry (GC-MS), both 24 h after sampling. Gas detector tubes were used for on-site measurement of gaseous compounds. Odorants that exceeded their published olfactory detection thresholds by the greatest order of magnitude, in decreasing order, were: H2S, dimethyl sulfide (DMS), butanoic acid, methanethiol, and trimethylamine. Concentrations of NH3 were not significantly correlated with OC, and they were not significantly affected by the use of aeration. Aeration reduced the OC and the combined H2S + DMS concentrations by 87 and 92%, respectively. There was a very close correlation (r = 0.948, P < 0.001) between the OC of bag samples and the combined H2S + DMS concentrations, measured on-site with detector tubes. This relationship was unaffected by the NH3 concentration or the type of compost: aerated or unaerated, pre-wet or Phase I, poultry manure-based or horse and poultry manure-based compost. Prediction of the OC will enable rapid and low-cost identification of odor sources on mushroom composting sites.

Agaricales↗