PubMed Health⌕ Search

Biomedical subjects

F L Wuyts

Publications and source records attributed to F L Wuyts.

At least 19 recordsLinked to original sources
PubMed2003

Target-controlled infusion of rocuronium in infants, children, and adults: a comparison of the pharmacokinetic and pharmacodynamic relationship.

UNLABELLED: Target-controlled infusion (TCI) of rocuronium can be used to maintain a stable blood concentration (Cp). At steady-state, the pharmacokinetics (PK) are compensated for by TCI, and a stable effect can be observed. The theoretical Cp may represent effect-site concentration (EC). We used the EC-effect relationship to study pharmacodynamics (PD) in infants, children, and adults. After giving their written, informed consent, 14 infants, 23 children, and 21 adults scheduled for elective surgical procedures received 3 to 6 ascending Cp targets of TCI rocuronium according to PD data. Just before each increase of TCI, venous blood samples were taken to measure Cp. Neuromuscular block was evaluated acceleromyographically. Individual effect data and measured Cp were fitted to the Hill equation. Maximum block during TCI targets-1000, 1300, and 1600 ng/mL-was smaller in children in comparison with infants and adults. The concentration in the effect compartment associated with a 50% drug effect (EC(50)) was significantly smaller in infants (mean [SD]) (652 [215] ng/mL) than in adults (954 [276] ng/mL) and was the largest in children (1200 [295] ng/mL). Calculated mean EC(90) values were 1705, 2230, and 2035 ng/mL, respectively, in infants, children, and adults. TCI rocuronium established steady-state PK/PD at different TCI targets and allowed us to define PK/PD relationships in a standardized way. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children. IMPLICATIONS: Target-controlled infusion (TCI) of rocuronium in infants, children, and adults was used to analyze the pharmacokinetic/pharmacodynamic relationship. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children.

Adolescent↗
PubMed2003

Arthroscopic subacromial decompression for advanced (stage II) impingement syndrome: a study of 52 patients with five years follow-up.

The authors report a prospective five-year follow-up study of 52 patients who had arthroscopic subacromial decompression for advanced (stage II: type 1 and 2) rotator cuff disease. All patients were assessed preoperatively, at six months and at five years postoperatively using the Constant-Murley score and the revised American Shoulder and Elbow Surgeons (ASES) score. From six months until five years postoperatively, 45 (out of 52) patients showed a further progressing improvement and relief of symptoms. This is established by a significant (p < 0.001) increase of the mean Constant-Murley score from 76.4 at six months postoperatively to 84.9 at five years postoperatively.

Adult↗
PubMed2002

Normative voice range profiles of male and female professional voice users.

Normative voice range profiles (VRP) are calculated for a group of male and female teachers, based on 43 and 46 recordings, respectively. All individuals had healthy voices. These normative VRPs contain 95% prediction intervals for both frequency and intensity. They are based on a series of mathematical transformations of the original individual VRPs in order to maintain in the normative VRPs the typical oval VRP shape, including the dip between modal and falsetto register. The normative VRPs presented are directly applicable in the clinical practice of otolaryngologists and speech-language pathologists.

Adult↗
PubMed2002

Poor voice quality in future elite vocal performers and professional voice users.

The voice quality of 86 occupational voice users, i.e., students of a high school for audiovisual communication, was assessed by means of a multidimensional test battery containing: the GRBAS scale, videolaryngostroboscopy, maximum phonation time, jitter, lowest intensity, highest frequency, dysphonia severity index (DSI), and voice handicap index (VHI). In a questionnaire on daily habits the prevalence of smoking, eating habits, and vocal abuse were recorded. A comparison of the voice characteristics of the future occupational voice users with a control group revealed significant differences. The results of the VHI and the DSI of these students revealed significantly worse scores than the score of a control group characterized by no vocal complaints. Moreover, the questionnaire on daily habits showed that the future elite vocal performers and professional voice users take less precautions for the care of their voices. These findings support the importance of a good balanced vocal coaching.

Adolescent↗
PubMed2001

MR features of peripheral nerve sheath tumors: can a calculated index compete with radiologist's experience?

The aims of this study were, firstly, to provide a formula (neurogenic index) based on MR characteristics used in daily routine for predicting whether a soft tissue tumor is neurogenic or not, secondly, to test prospectively the performance of this formula, and thirdly, to compare this performance with that of radiologists experienced in MR imaging of soft tissue tumors. Retrospectively, MR images of 70 neurogenic and 70 non-neurogenic soft tissue tumors were evaluated in random order by two teams of two observers each. A neurogenic index (NI) was calculated based on those MR parameters that showed no or minor interobserver variability. Subsequently, three investigators in concert used the NI in a validation group of 15 neurogenic and 22 nonneurogenic soft tissue tumors. The same team, based on their own experience, tried to differentiate in the same validation group neurogenic from non-neurogenic soft tissue tumors. This was expressed in a subjective score (SS). Sensitivity, specificity, and predictive values were calculated. NI comprised spread (intra- or extracompartmental), distribution, fluid-fluid levels, homogeneity on T2-weighted images (WI), highest signal intensity (SI) on T1WI, lowest SI on T2WI, and delineation on T2WI. In the validation group, NI had a sensitivity of 88.6%, a specificity of 52.0%, a positive predictive value (PPV) of 54.1%, and a negative predictive value (NPV) of 84.6% for neurogenic tumors. The subjective score SS was superior and had a sensitivity of 93.3%, a specificity of 77.2%, a PPV of 73.7%, and a NPV of 94.4%. Our NI was less accurate than the SS; however, the low number of false-negative diagnoses for neurogenic tumors warrants continued efforts in development of neural networks.

Adolescent↗
PubMed2001

Rate influences on tone burst summating potential amplitude in electrocochleography: clinical(a) and experimental(b) data.

Electrocochleographic recordings of action and summating potentials are widely used in the electrophysiological assessment of endolymphatic hydrops (ELH). Increased amplitudes of the summating potential (SP) in response to tone burst stimuli are indicative of positive ELH. This study reports the effect of repetition rate of tone burst stimulation on the SP amplitude. Using transtympanic electrocochleography (ECochG), the SP in response to 1 kHz tone bursts was recorded in both a Ménière and a non-Ménière population. Absolute values of the SP were systematically higher in the Ménière group. Moreover, in the Ménière and non-Ménière groups, the response amplitudes of the SP at a repetition rate of 8.4 tone bursts/s were only 66 and 32%, respectively, of the maximal response amplitude which was obtained at the rate of 37.4 tone bursts/s. Additionally, in normal guinea pigs chronically implanted with a round window electrode, the SP was recorded to 0.5-16 kHz tone burst stimulations presented at 100 dB SPL with the same different repetition rates. Similar enhancement of the SP amplitude was observed from 8.4 to 37.4 stimuli/s, whatever the frequency. This effect is interpreted as an increased asymmetry of vibration of the cochlear partition, whose mechanical operating point would not return to the normal resting position at high repetition rates, since it is permanently shifted in ELH.

Acoustic Stimulation↗
PubMed2001

Otolith function after acoustic neuroma surgery.

The response of the vestibular system after acoustic neuroma surgery was investigated in nine patients. The otolith system was studied by means of ocular counterrolling, assessed by video oculography. Horizontal vestibulo-ocular reflex (VOR) function was tested by the sinusoidal harmonic acceleration test using electronystagmography. The results were compared with those obtained from a normal control population. The response to slow rotation tests was symmetric, but the gain was significantly reduced when compared to the normal population. Phase lag was significantly increased. No difference in ocular torsion was observed with lateroflexion of the head to the ipsilateral side in comparison with lateroflexion to the contralateral side. Moreover, the overall ocular counterrolling was well within normal limits. We conclude that the semicircular canal response differs from the otolith response. The component of the torsional VOR mediated by otolith stimulation appears to be more robust than the horizontal VOR mediated mainly by the horizontal semicircular canal system. Ocular counterrolling induced by lateroflexion does not reveal abnormalities in patients with surgically produced unilateral peripheral loss.

Adult↗
PubMed2001

Hereditary otovestibular dysfunction and Ménière's disease in a large Belgian family is caused by a missense mutation in the COCH gene.

OBJECTIVE: To report the clinical, auditory, and vestibular characteristics of a nonsyndromic otovestibular dysfunction in a large Belgian family caused by a missense mutation of the DFNA9 gene: COCH. STUDY DESIGN: Retrospective study of the clinical, audiologic, and vestibular data of 60 genetically affected cases. SETTING: Tertiary referral center. PATIENTS: All members of a Belgian kindred who carry the genetic (P51S) defect linked to the inherited hearing and vestibular impairment. INTERVENTIONS: Diagnostic otologic, audiometric, and vestibular analysis and imaging. MAIN OUTCOME MEASURES: Pure tone audiometry, supraliminary audiometry. and vestibular investigation. RESULTS: The autosomal dominant inherited impairment was characterized by peripheral degeneration of the inner ear, leading to total deafness and bilateral vestibular areflexia. CONCLUSIONS: The genetically affected persons of a Belgian family shared a progressive sensorineural hearing loss starting between the third and sixth decade. Vestibular symptoms started at about the same age as the hearing loss. The vestibular symptoms consisted of instability in darkness, a tendency to fall sideways, light-headiness, a drunken feeling, and attacks of vertigo. Most of the patients reported tinnitus, and half of them reported pressure in the ears. Clinically, 9 of the 60 patients met the criteria for definite Ménière's disease, and another 13 and 17 patients met the criteria for probable or possible Ménière's disease, respectively. All 9 were older than the age of 35, but only 1 was older than 55 years, so more than 30% of the patients were between 35 and 55 years old. A specific pattern could be recognized in the evolution of the otovestibular impairment. Under the age of 35 years, almost all the affected family members had normal hearing, whereas above the age of 55 years, the hearing loss was at least moderate, and vestibular hypofunction occurred. In between, there was a transition period of two to three decades, when deterioration of the cochleovestibular function occurred, with a temporary audiometric and vestibular asymmetry.

Adult↗
PubMed2001

Nasometric values for normal nasal resonance in the speech of young Flemish adults.

OBJECTIVE: The purpose of this study was to obtain normative nasalance scores for adult subjects speaking the Flemish language. Additional objectives of the study were to determine if speaker sex played a role in differences in nasalance scores and if significantly different nasalance scores existed for Flemish compared with other languages or dialects. DESIGN: Nasalance scores were obtained while young Flemish adults read three standard nasalance passages. These passages were an oronasal passage (a text that contained the same approximate percentage of nasal consonants as found in the standard Dutch speech), an oral passage (a text that excluded nasal consonants), and a nasal passage (a reading text loaded with nasal consonants). PARTICIPANTS: Subjects included 58 healthy young Flemish adults with normal oral and velopharyngeal structure and function, normal hearing levels, normal voice characteristics, and normal resonance and articulation skills. METHODS: The Nasometer (model 6200) was used to obtain nasalance scores for the three reading passages. These three reading passages were designed specifically for use with the nasometer. The nasalance data were analyzed for sex dependence, using Student's t test for each reading passage. This same test was used for comparison of our data with data of other languages. RESULTS: Normative nasalance data were obtained for the oronasal text (33.8%), the oral text (10.9%), and the nasal text (55.8%). Female speakers exhibited significantly higher nasalance scores than male speakers on the passages containing nasal consonants (normal text, p = .001; nasal text, p = .042). Furthermore, statistically significant cross-linguistic nasality differences were observed. The English and Spanish languages were found to have more nasalance than the Flemish language. For the North Dutch and Flemish languages, this cross-linguistic phenomenon was absent. CONCLUSION: These normative nasalance scores for normal young adults speaking the Flemish language provide important reference information for Flemish cleft palate teams. Sex-related differences and cross-linguistic differences were shown.

Adult↗
PubMed2000

Accuracy of computer navigation in ear, nose, throat surgery: the influence of matching strategy.

OBJECTIVE: To measure the effect of 4 different matching strategies on the accuracy of computer navigation on the face and within the nose and rhinopharynx. DESIGN: Survey. SETTING: Laboratory study. SUBJECTS: Six human cadavers studied within 24 hours of death. INTERVENTIONS: A commercially available navigation system with infrared optical tracking was used for computer navigation on the face and within the nose of the subjects after matching with external fiducials or with 3 different configurations of anatomical landmarks. Navigation errors were measured and correlated to matching strategies and compared through statistical analysis. RESULTS: Matching with external fiducials on the face results in smaller navigation error than matching with anatomical landmarks. The configuration of matching strategies with anatomical landmarks also significantly determines the accuracy of computer navigation, especially when different locations of accuracy measurement are considered. CONCLUSION: Statistically significant findings have shown that the choice of a matching strategy is a major factor in the accuracy of computer navigation for ear, nose, throat surgery. Arch Otolaryngol Head Neck Surg. 2000;126:1462-1466

Cadaver↗
PubMed2000

The dysphonia severity index: an objective measure of vocal quality based on a multiparameter approach.

The vocal quality of a patient is modeled by means of a Dysphonia Severity Index (DSI), which is designed to establish an objective and quantitative correlate of the perceived vocal quality. The DSI is based on the weighted combination of the following selected set of voice measurements: highest frequency (F(0)-High in Hz), lowest intensity (I-Low in dB), maximum phonation time (MPT in s), and jitter (%). The DSI is derived from a multivariate analysis of 387 subjects with the goal of describing, purely based on objective measures, the perceived voice quality. It is constructed as DSI = 0.13 x MPT + 0.0053 x F(0)-High - 0.26 x I-Low - 1.18 x Jitter (%) + 12.4. The DSI for perceptually normal voices equals +5 and for severely dysphonic voices -5. The more negative the patient's index, the worse is his or her vocal quality. As such, the DSI is especially useful to evaluate therapeutic evolution of dysphonic patients. Additionally, there is a high correlation between the DSI and the Voice Handicap Index score.

Adolescent↗
PubMed2000

Computerized electronystagmography: normative data revisited.

This study provides normative data from computerized electronystagmography (ENG) testing of 40 healthy subjects with an average age of 45 years. The clinical test protocol comprises an extensive vestibular examination with oculomotor, positional, rotary chair and caloric tests. The results show that with a computerized ENG set-up considerable variabilities of 22% for rotary chair asymmetry and 19% for caloric labyrinth asymmetry remain.

Adult↗
PubMed2000

Benefit of emergency haemorrhoidectomy: a comparison with results after elective operations.

OBJECTIVE: To compare the outcome of emergency and elective haemorrhoidectomy. DESIGN: Retrospective study. SETTING: Teaching hospital, Belgium. SUBJECT: 104 patients who had haemorrhoidectomy for acutely ulcerated or strangulated haemorrhoids, and 545 who had elective haemorrhoidectomy. RESULTS: Early complications (26/104, 25%), reoperation (7/104, 7%) and late anal stenosis (7/104, 7%) were more common after emergency than elective haemorrhoidectomy, for which the corresponding figures were 74/545 (3.6%), 9 (1.7%) and 1/545 (0.2%). Late outcome was similar for the two groups. CONCLUSIONS: Emergency haemorrhoidectomy is indicated for the treatment of the acute complications of haemorrhoids.

Acute Disease↗
PubMed2000

Quantitative measurement of the PCCC area in the postoperative period.

BACKGROUND/AIMS: The major complication of extracapsular cataract extraction (ECCE) is posterior capsule opacification (PCO). Posterior continuous circular capsulorhexis (PCCC) seems to be very promising in preventing PCO. This study was aimed at determining if the PCCC area changes as a function of time and if pearl formation could influence it. METHODS: 24 eyes of 23 patients underwent ECCE with PCCC. Retroillumination photographs were taken at 6 months and then yearly. To measure the PCCC area, the computerised program EPCO (evaluation of posterior capsule opacification) was used. The ratio of the PCCC area in relation to the IOL surface was calculated for the different time stages and the presence of pearl formation was noted. Firstly, proportional changes in diameter were compared in PCCC areas measured after 6 months and after 1 year (group I, n=13) and after 1 year and 2 years (group II, n=14). Secondly, PCCC areas were compared between two time stages in patients with (group III, n=19) and without pearl formation (group IV, n=8). RESULTS: No statistically significant difference was found in diameter change in either group. The PCCC area remains stabile between 6 months to 1 year and 1 year to 2 years. No differences are found between eyes with or without pearl formation. CONCLUSIONS: The PCCC area remains stable as a function of time and is not influenced by pearl formation.

Adult↗
PubMed2000

Audiometric analysis of a Belgian family linked to the DFNA10 locus.

OBJECTIVE: To report the otologic and audiometric characteristics of a nonsyndromic postlingual sensorineural hearing impairment in a Belgian family linked to DFNA10. STUDY DESIGN: Retrospective study of the otologic and audiometric data of 17 genetically affected persons. SETTING: Tertiary referral center. PATIENTS: All members of a Belgian kindred who carried the haplotype linked to the inherited hearing impairment of DFNA10. INTERVENTIONS: Diagnostic otologic and audiometric analysis. MAIN OUTCOME MEASURES: Pure-tone audiometry. RESULTS: To find the frequencies that were most affected by the genetic defect, the excess hearing loss of the 17 patients was calculated per frequency in comparison with the respective p50 and p95 thresholds of the normal population. CONCLUSIONS: The genetically affected persons of a Belgian family shared a progressive symmetric sensorineural hearing loss that started in the first to fourth decade. Thirty-five percent of the affected family members had tinnitus, and only one patient had very mild vestibular complaints. At onset, hearing losses were mainly situated at the midfrequencies. With increasing age, all frequencies became affected. The hearing loss was initially mild, with a spontaneous evolution to a moderate or severe hearing impairment. The progression of the hearing loss for the pure-tone average (between 0.5 and 4 kHz) was 1.08 dB/year for this family, compared with 0.50 dB/year and 0.35 dB/year at the 95th and 50th percentiles of the normal population, respectively.

Adult↗
PubMed1999

Is the reliability of a visual analog scale higher than an ordinal scale? An experiment with the GRBAS scale for the perceptual evaluation of dysphonia.

Perceptual evaluation of 14 pathological voices was performed by 29 listeners using the GRBAS scale. To evaluate scale effects on the judgments, 2 versions of the scale were presented: the original 4-point scale and a visual analog scale. Each listener used the same voice samples for both versions of the scale with an interval of 2 weeks. Agreement was found to be higher with the original 4-point scale than with the visual analog version for all scale items G, R, B, A and S. Although a visual analog scale seems to enable a finer judgment of voice quality, this study showed that, with increased freedom of judgment, the interrater agreement decreased considerably. Therefore, we recommend the use of the original 4-point version of the GRBAS scale.

Adolescent↗
PubMed1999

Experimental study of intraperitoneal suramin on the healing of colonic anastomoses.

INTRODUCTION: The effect of the antiangiogenic agent suramin on the healing of colonic anastomoses was studied in a rat model. METHODS: Rats underwent an end-to-end colonic anastomosis and its healing was tested by measuring bursting pressure, hydroxyproline content and number of newly formed vessels. For the bursting pressure experiment suramin was given intraperitoneally in a dose of 200 mg/kg (maximal tolerable dose) and 100 mg/kg. Hydroxyproline content and vessel density were only tested at 100 mg/kg since the toxicity at this dose was lower whereas bursting pressure was still diminished. RESULTS: There were no deaths. On the fourth day after operation bursting pressure in the control group was significantly higher than that in rats treated with suramin 200 mg/kg (P = 0.006) and 100 mg/kg (P = 0.002). Rupture occurred at the anastomotic line. On day 7, this difference was not statistically significant. Four days after the operation, the hydroxyproline content and vessel density were significantly below that in control segments (hydroxyproline: 10.3 versus 7.8 microg per mg dry weight; vessel content: 85.7 versus 49.6 vessels per x 100 field for control and suramin-treated rats respectively). On the seventh day no difference in hydroxyproline levels was seen but the vessel density was still diminished significantly (P = 0.04). CONCLUSION: Experimentally, suramin significantly inhibits and delays healing of colonic anastomoses. Presented in part to the XXXII Congress of the European Society for Surgical Research in Corfu, Greece, May 1997

Anastomosis, Surgical↗