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T Hummel

Publications and source records attributed to T Hummel.

At least 73 records · Page 4Linked to original sources
PubMed2001

A threshold-like measure for the assessment of olfactory sensitivity: the "random" procedure.

Many tests of olfactory dysfunction are either too complex, too expensive, or too time-consuming to be of use in routine clinical testing. Thus, the present multicenter study was undertaken to investigate a new approach, the so-called "random" test. In this test different concentrations of citronellal and phenyl ethyl alcohol are applied according to a pre-established order; patients are asked to identify the odor if possible. The test score is the sum of correctly identified odors. Test administration takes about 10 min. Two studies were performed. Basic characteristics of the test were explored in experiment 1 in 176 healthy subjects (76 male, 100 female; age 12-85 years, mean age 30 years), namely test-retest reliability, correlation with other measures of olfactory sensitivity, and sensitivity of the test to differences in age and gender. In the second experiment the test was tried in 97 patients (45 male, 52 female; age 19-78 years, mean age 47 years) in a clinical environment to investigate its usefulness in diagnosing olfactory loss. The "random"-test was found (1) to exhibit a test-retest reliability similar to that reported for established measures of olfactory function (r = 0.71; P < 0.001), (2) to correlate with other measures of olfactory sensitivity (0.82 > r > 0.60; P < 0.001), (3) to differentiate between expected differences in olfactory sensitivity in relation to gender (t > 2.602, P < 0.011), and (4) to discriminate between different degrees of olfactory loss (F > 36.6, P < 0.001). Based on these data, and the fact that the new test requires little time and is easy to use, this approach can be expected to suit clinical needs.

Adolescent↗
PubMed2001

Glial cell development in Drosophila.

In the Drosophila central nervous system (CNS) about 10% of the cells are of glial nature. A set of molecular markers has allowed unraveling a number of genes controlling glial cell fate determination as well as genes required for glial cell differentiation. Here we focus on the embryonic CNS glia and review the recent progress in the field.

Animals↗
PubMed2001

Patients with rheumatoid arthritis adapt differently to repetitive painful stimuli compared to healthy controls.

The aim of the study was to investigate whether there are changes of the nociceptive system in patients with chronic inflammatory joint pain. A pain model was used which is based on the recording of cortical chemo-somatosensory event-related potentials (CSSERP) after nociceptive stimulation of the nasal mucosa with gaseous carbon dioxide (CO(2)). Twenty-five patients with rheumatoid arthritis (RA) were compared to healthy controls matched for age and gender. Responses to both different intensities of painful stimuli and constant intensities of series of 4 stimuli were analysed. When testing increasing CO(2) concentrations ratings and CSSERP amplitudes increased for both patients and controls. However, when repetitive stimulation was performed with an interval of 2s CSSERP amplitudes N1 were significantly greater in RA patients. It is hypothesized that chronic inflammatory joint pain changes nociceptive processing in terms of generalized changes of the nociceptive system which may amplify chronic pain.

Adaptation, Physiological↗
PubMed2001

[The enjoyment of red wine is influenced by the shape of the wine glass].

BACKGROUND: It is frequently claimed that the glass shape has a direct impact on wine aroma. METHODS, PATIENTS: Healthy volunteers (43 m, 46 f, age 19-60 years) tried 3 glasses. Three glasses of different shape but of the same height and of comparable opening diameter were used. Glasses were of "tulip"-like, "beaker"-like, and "egg"-like shapes. Intensity, hedonic tone, and quality of a red wine were rated before and after drinking. RESULTS: Both intensity and hedonic ratings of wines from different glasses were influenced by glass shape. Glass shape also influenced the complexity of wine odors. This appeared not to be related to the esthetic impression the glasses made. CONCLUSIONS: The present data indicate that egg-shaped glasses, compared to "tulip" or "beaker" glasses, appear to produce higher intensity and higher complexity of wine odors. This may relate to the trapping of odors in egg-shaped glasses.

Adult↗
PubMed2001

[Normal sense of smell in Kallmann syndrome. A case report].

BACKGROUND: Kallmann's syndrome (KS) was first mentioned in 1944 as an association of anosmia and hypogonadotropic hypogonadism. Causes are multiple genetic defects the most common of which is the x-linked KS appearing mostly in men. However, autosomal dominant and autosomal recessive forms have also been described. PATIENT: We present a case of KS with normosmia (male, 39 years of age). All symptoms of hypogonadotropic hypogonadism were present. RESULTS: Psychophysical olfactory testing revealed left-sided anosmia with right-sided normosmia which was confirmed by electrophysiological measures of olfactory function. Magnetic resonance imaging indicated aplasia of the left olfactory tract and bulb, whereas the right-sided structures appeared to be normal. CONCLUSIONS: As indicated in this case with lateralized anosmia and contralateral normosmia, overall olfactory function strongly depends on the "best" nostril. Therefore, in many clinical situations, lateralized olfactory testing appears to be extremely important.

Adult↗
PubMed2001

Imaging of the human vomeronasal duct.

The human vomeronasal duct (VND) is described as a tubular or pouch-like mucosal invagination of the anterior nasal septum. This study investigated shape, size and orientation of the VND using magnetic resonance imaging (MRI). Fifteen subjects participated (eight women, seven men; mean age 39 years, age range 18-66 years); they had been pre-selected with regard to the presence of a VND opening of 1 mm. MRI was performed before and after application of diluted gadolinium-diethylene-triamino-penta-acetic actetate (Gd-DTPA) into the left or right VND. A tubular structure was found in 12 subjects with a median length of 7 mm (range 3-22 mm; one VND with a length 47 mm). In three subjects a nearly circular, pouch-like structure was observed. Seven of the tubular VNDs were slightly bent upwards, the other five VNDs ran parallel to the floor of the nasal cavity. There was no significant gender-related difference in the length of VNDs. These data indicate considerable variability of shape, size and orientation of the human VND.

Adolescent↗
PubMed2001

Frequency and localization of the putative vomeronasal organ in humans in relation to age and gender.

OBJECTIVES/HYPOTHESES: In many species the vomeronasal organ (VNO) serves as a chemosensory organ in addition to the olfactory system. The present investigation was undertaken to study 1) the frequency of monolateral or bilateral detection of the putative VNO (pVNO) in humans, 2) its localization in humans, and 3) whether detectability of the pVNO varies with age or gender. STUDY DESIGN: Prospective. METHODS: A total of 173 subjects participated in this study (88 women and 85 men; age range, 2-91 y). Inspection of the nose was performed with a speculum and a 30 degrees endoscope. The exact localization of the VNO was measured with custom-built rulers. RESULTS: The study revealed the following major results: 1) A pVNO is detectable in approximately two-thirds of the population and bilateral pVNOs are present in approximately 40% of investigated subjects, 2) its localization on the left and right nasal septum is almost symmetrical, and 3) and detectability of the pVNO is not related to age or gender. CONCLUSIONS: The present data indicated that the pVNO is present in approximately two-thirds of the population. This value may be biased by methodological or biological factors; nevertheless, it indicates that the pVNO is not observed in all humans regardless of age and gender. Thus, considering its variability in shape and immunohistochemical characteristics and the missing nerval connections between the peripheral "organ" and the central nervous system, the present results are not suited to argue for a functional significance of the pVNO in humans.

Adolescent↗
PubMed2001

Olfactory function in patients with olfactory groove meningioma.

OBJECTIVES: Olfactory meningiomas are rare benign tumours and represent about 12% of all basal meningiomas. Anosmia is thought to be among the first symptoms, even though patients often present with headaches or visual problems. However, so far no detailed psychophysical tests of olfactory function have been performed in a large number of those patients. METHODS: Twelve patients (five men, seven women; mean age 52 years) with olfactory meningiomas were examined. In all patients extensive preoperative and postoperative lateralised olfactory testing was performed using the "Sniffin' Sticks" test battery, a psychometric testing tool. In eight cases the meningioma was lateralised (five left, three right), in four patients a bilateral meningioma was found. In addition to a detailed ear, nose, and throat examination MRI was performed in all patients. RESULTS: In preoperative testing six patients were found to be anosmic on the side of the tumour, two were hyposmic. Four patients were normosmic. Postoperative investigations showed lateralised anosmia in four patients on the operated side, three were normosmic on the contralateral side and one hyposmic. The remaining eight patients were completely anosmic postoperatively. CONCLUSIONS: (1) Contrary to expectations, olfactory testing seems to be of little help in detecting olfactory meningiomas. (2) The likelihood of normal postoperative olfactory function contralateral to the tumour was high when the tumour was less than 3 cm in diameter and preoperative normosmia had been established. (3) Preservation of olfactory function ipsilateral to the tumour seems to be extremely difficult, irrespective of tumour size or surgical approach.

Adult↗
PubMed2001

Screening of olfactory function with a four-minute odor identification test: reliability, normative data, and investigations in patients with olfactory loss.

The study aimed to create a screening test on the basis of the odor identification test as used in the "Sniffin' Sticks" olfactory test kit. It should appeal to the practitioner in terms of 1) time required for testing, 2) reliability, 3) separation of "normal" from "abnormal," and 4) the fact that it allows lateralized screening. Experiments should provide a normative database (number of subjects > 1,000), establish test-retest reliability (n > 100), and compare results from patients with olfactory loss (n > 200). The correlation between results on 2 repetitive tests was .78. The test differentiated anosmics, hyposmics, and normosmics (p < .001). None of the 112 anosmics reached a score higher than 8; the 90th percentile was at a score of 6. When only 6 odors were used for calculating scores, for anosmics the 95th percentile was at a score of 4. These data provide a basis for the screening of patients by means of "Sniffin' Sticks."

Adolescent↗
PubMed2001

Peripheral levels of inflammatory mediators in migraineurs during headache-free periods.

OBJECTIVES: The present study investigated the peripheral inflammatory changes of the trigeminovascular system by measuring the inflammatory mediators leukotriene B4 (LTB(4)), prostaglandin E2 (PGE(2)), and thromboxane B2 (TXB(2)) in the nasal fluid, as well as saliva, of patients with migraine. BACKGROUND: Migraine has been hypothesized to be as a result of changes in the peripheral or central nervous system or both. It is still unclear whether peripheral changes in the trigeminovascular system are involved in the pathogenesis of migraine. METHODS: Participants were 18 subjects, 9 patients with migraine and 9 controls, matched for age and sex. Each subject took part in one experimental session during which nasal lavage fluid and saliva samples were collected. These samples were analyzed by competitive enzyme immunoassay using goat anti-rabbit polyclonal antibody. RESULTS: With the exception of TXB(2), correlational analyses indicated good correlations between results obtained using nasal lavage or saliva (LTB(4), r(18) = 0.91; PGE(2), r(18) = 0.95). When comparing inflammatory mediators measured in controls and migraineurs, the LTB(4) level was significantly lower in migraineurs, while no differences were found for PGE(2) and TXB(2). CONCLUSIONS: The study demonstrated that nasal lavage, a noninvasive method, can be easily used for investigations of pathophysiological mechanisms of migraine. In addition, the results may indicate that there is no peripheral trigeminal sensitization in the headache-free period of migraineurs compared with controls when PGE(2), LTB(4), and TXB(2) in saliva and nasal lavage samples are measured.

Adult↗
PubMed2000

3-Methylindole alters both olfactory and trigeminal nasal mucosal potentials in rats.

Data from human studies imply that vanillin is an olfactory stimulant, whereas CO2 activates intranasal trigeminal nociceptors. We examined the effects of the olfactotoxin 3-methylindole (3-MI) on nasal mucosal potentials evoked by vanillin and CO2 in rats. A single i.p. administration of 300 mg/kg 3-MI altered both olfactory and trigeminal mucosal responses. Relative to amplitude values determined in non-3-MI-injected rats, the response to vanillin was reduced to 6%, 7%, and 43%, and the response to CO2, recorded in the same rats, decreased to 25%, 38%, and 51% at 4, 8 and 16 days post-3-MI, respectively. The results suggest that 3-MI affects both olfactory and trigeminal elements within the nasal mucosa.

Animals↗
PubMed2000

The Drosophila HEM-2/NAP1 homolog KETTE controls axonal pathfinding and cytoskeletal organization.

In Drosophila, the correct formation of the segmental commissures depends on neuron-glial interactions at the midline. The VUM midline neurons extend axons along which glial cells migrate in between anterior and posterior commissures. Here, we show that the gene kette is required for the normal projection of the VUM axons and subsequently disrupts glial migration. Axonal projection defects are also found for many other moto- and interneurons. In addition, kette affects the cell morphology of mesodermal and epidermal derivatives, which show an abnormal actin cytoskeleton. The KETTE protein is homologous to the transmembrane protein HEM-2/NAP1 evolutionary conserved from worms to vertebrates. In vitro analysis has shown a specific interaction of the vertebrate HEM-2/NAP1 with the SH2-SH3 adapter protein NCK and the small GTPase RAC1, which both have been implicated in regulating cytoskeleton organization and axonal growth. Hypomorphic kette mutations lead to axonal defects similar to mutations in the Drosophila NCK homolog dreadlocks. Furthermore, we show that kette and dock mutants genetically interact. NCK is thought to interact with the small G proteins RAC1 and CDC42, which play a role in axonal growth. In line with these observations, a kette phenocopy can be obtained following directed expression of mutant DCDC42 or DRAC1 in the CNS midline. In addition, the kette mutant phenotype can be partially rescued by expression of an activated DRAC1 transgene. Our data suggest an important role of the HEM-2 protein in cytoskeletal organization during axonal pathfinding.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Oral mucosal blood flow following dry ice stimulation in humans.

The aim of the current pilot study was to establish a procedure that would allow the investigation of microcirculatory changes in the oral cavity. The authors studied the effects of painful stimulation using dry ice (CO2). To investigate potential regional differences in the change of blood flow, recordings were made for the tongue and at the mucosa of the hard palate, lip, and oral vestibule. The authors investigated 26 patients divided into groups of younger subjects (10 men, 3 women; age range 21-31 y) and older patients (2 men, 11 women; age range 54-74 y). Mucosal blood flow (mBF) was obtained at the hard palate, at the tip of the tongue, on the midline of the oral vestibule, and at the lip. Measurements were made during rest and for 2 minutes after application of dry ice for a 10-second duration, using a pencil-shaped apparatus. Blood pressure, heart rate, cutaneous blood flow, transcutaneous partial pressure of carbon dioxiode (PCO2) and partial pressure of oxygen (PO2) were recorded. Mucosal blood flow increased at all sites in response to application of dry ice (p <0.001), with peak flow at 0.5 minute to 1.5 minutes after onset of stimulation. During the 1.5 minutes to 2 minutes, blood flow decreased at all measurement sites with a tendency to return to baseline. Heart rate, blood pressure, pCO2, PO2, and cutaneous blood flow did not show significant changes. Overall, responses in older patients showed more variance when compared with younger patients. Stimulation by dry ice appears to be an effective, noninvasive, and tolerable means to investigate mucosal blood flow at different mucosal sites. Preliminary data indicate different levels of responsiveness to painful cold stimulation at different sites on the oral and perioral mucosa; particularly, mucosal blood flow response at the tongue was least pronounced. Therefore, assessment of stimulated mucosal blood flow appears to be a promising tool to investigate the pathophysiology of a number of neurologic symptoms, eg, the burning mouth syndrome.

Adult↗
PubMed2000

Pulmonary function and health-related quality of life in a sample of long-term survivors of the acute respiratory distress syndrome.

OBJECTIVE: We performed a follow-up cohort analysis in order to delineate the correlation between pulmonary function (PF) and health-related quality of life (HRQL) in patients after ARDS. DESIGN: Follow-up cohort study. SETTING: A 20-bed ICU of a university teaching hospital. PATIENTS: A cohort of 50 long-term survivors of ARDS. MEASUREMENTS AND RESULTS: Measurements of PF (FVC, FEV1, TLC, D(LCO)) and HRQL (SF-36 Health Status Questionnaire) were made 5.5 years (median value) after discharge from the ICU. Impairments in PF (defined as PF results below 80% of the predicted value) were frequent but generally mild. Twenty patients had a single PF impairment (with limitations in FEV1/FVC ratio in 12 patients being the most common), four patients had two (with D(LCO) and FEV1/FVC ratio impairment the most common) and three patients had pathologic results in three PF tests (FEV1/FVC ratio, TLC and capillary pO2 during exercise in one case, FVC, TLC and capillary pO2 during exercise in the second patient and FVC, TLC and D(LCO) in the third). Compared to normal controls, survivors of ARDS showed impairments in all SF-36 health dimensions (p < 0.001). Patients with multiple (> 1) PF impairments described the lowest HRQL with major limitations in all SF-36 categories (p < 0.037) including physical and mental summary scores (36.5 vs 46.9, p = 0.037 and 31.3 vs 51.4, p = 0.003) when compared to patients with no or only one PF impairment. CONCLUSIONS: Long-term survivors of ARDS have a significant reduction in HRQL and the presence of multiple PF impairments is associated with maximal decrements in HRQL.

Adult↗
PubMed2000

Multicenter investigation of 1,036 subjects using a standardized method for the assessment of olfactory function combining tests of odor identification, odor discrimination, and olfactory thresholds.

"Sniffin' Sticks" is a test of nasal chemosensory performance that is based on penlike odor-dispensing devices. It is comprised of three tests of olfactory function: tests for odor threshold, discrimination and identification. Previous work has already established its test-retest reliability and validity in comparison to established measures of olfactory sensitivity. The results of this test are presented as a composite TDI score--i.e., the sum of results obtained for threshold, discrimination and identification measures. The present multicenter investigation aimed at providing normative values in relation to different age groups. To this end, 966 patients were investigated in 11 centers. An additional study tried to establish values for the identification of anosmic patients, with 70 anosmics investigated in five specialized centers where the presence of anosmia was confirmed by means of olfactory evoked potentials. For healthy subjects, the TDI score at the 10th percentile was 24.5 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 28.8 for ages from 36 to 55 years and 27.5 for subjects older than 55 years. While these data can be used to estimate individual olfactory abilities in relation to a subject's age, hyposmia was defined as the 10th percentile score of 16- to 35-year-old subjects. Our latter study revealed that none of 70 anosmics reached a TDI score higher than 15. This score of 15 is regarded as the cut-off value for functional anosmia. These results provide the basis for the routine clinical evaluation of patients with olfactory disorders using "Sniffin' Sticks."

Adolescent↗
PubMed2000

Immunohistochemical distribution of galectin-1, galectin-3, and olfactory marker protein in human olfactory epithelium.

The expression pattern of galectin-1 and galectin-3 in the human olfactory epithelium was investigated in relation to olfactory marker protein (OMP) using confocal laser immunofluorescence in human specimens and postmortem biopsies. OMP expression was found in olfactory receptor neurons (ORNs) in the olfactory mucosa and in fibers of the olfactory nerve crossing the submucous connective tissue. Galectin-1 was expressed in both the connective tissue of the nasal cavity and in the basal layer of the olfactory epithelium. In contrast, galectin-3 expression was limited to cells of the upper one-third of the olfactory epithelium. Expression of galectin-3 occurred in a subset of OMP-positive cells. However, between areas of galectin-1 and galectin-3 expression in the lower and upper portion of the epithelium, OMP-positive ORNs did not stain for both galectins. Considering the potential role of galectin-1 and galectin-3 in cell differentiation and maturation, the differential localization of galectins in the olfactory epithelium appears to be consistent with a significant role of these molecules in the physiological turnover of ORNs.

Adolescent↗