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Laurent, Claude
Publications (10 of 15) Show all publications
Holm, A., Hellman, U., Laurent, C., Laurell, G., Nylander, K. & Olofsson, K. (2018). Hyaluronan in vocal folds and false vocal folds in patients with recurrent respiratory papillomatosis. Acta Oto-Laryngologica, 138(11), 1020-1027
Open this publication in new window or tab >>Hyaluronan in vocal folds and false vocal folds in patients with recurrent respiratory papillomatosis
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2018 (English)In: Acta Oto-Laryngologica, ISSN 0001-6489, E-ISSN 1651-2251, Vol. 138, no 11, p. 1020-1027Article in journal (Refereed) Published
Abstract [en]

Background: Hyaluronan (HA) is a glycosaminoglycan with viscoelastic properties necessary for vocal fold (VF) vibration and voice production. Changes in HAs molecular mass, possibly related to human papilloma virus, could affect formation/persistence of recurrent respiratory papillomatosis (RRP).

Aims/Objective: Describing mass and localization of HA and localization of HA receptor CD44 in VF and false vocal folds (FVF) in RRP.

Materials and Methods: Biopsies from VF and FVF from 24 RRP patients. Twelve were studied with histo-/immunohistochemistry for HA and CD44 in epithelium, stroma and RRP lesions. Twelve samples were analyzed for HA molecular mass distribution with gas-phase-electrophoretic-molecular-mobility-analyzer (GEMMA).

Results: Three of 23 stains (VF and FVF combined) showed faint HA staining in the epithelium; there was more extensive staining in the stroma. CD44 was present throughout all areas in FVF and VF, it did not concur with HA. GEMMA analysis revealed very high mass HA (vHMHA) with more varying amounts in VF.

Conclusions/Significance: HA was mainly distributed in the stroma. CD44 not binding to HA might explain the non-inflammatory response described in RRP. Possibly crosslinked vHMHA was seen in VF and FVF, with more variable amounts in VF samples. Counteracting HA crosslinking could become a treatment option in RRP.

Abstract [zh]

背景:透明质酸(HA)是一种糖胺聚糖, 具有声带(VF)振动和发声所必需的粘弹性。HA 分子量的变化可能与人乳头瘤病毒相关, 还可能影响复发性呼吸道乳头状瘤病(RRP)的形成或持续。

目的:描述HA的量和定位, HA受体CD44在VF中的定位和假性声带(FVF)在RRP中的定位。

材料和方法:24名RRP患者的VF和FVF的活组织检查。用组织/免疫组织化学方法研究12个样品的上皮、基质和RRP病变中的HA和CD44。用气-相-电泳 - 分子-迁移率-分析仪(GEMMA)分析另12个样品的HA分子量分布。

结果:23个染色中的3个(VF和FVF组合)在上皮细胞中显示出微弱的HA染色;基质中有更强的染色。 CD44存在于FVF和VF的所有区域, 它与HA不同时存在。 GEMMA分析显示非常高量的HA(vHMHA), 它在VF中的量多变。

结论/意义:HA主要分布在基质中。 CD44不与HA接合可能解释所描述的RRP中的非炎症反应。在VF和FVF中观察到可能交合的vHMHA, 而在VF样品中具有更多的变量。抗HA交合可能成为RRP的治疗选择。

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
Vocal folds, hyaluronan, CD44, human papilloma virus, recurrent respiratory papillomatosis
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-156749 (URN)10.1080/00016489.2018.1500712 (DOI)000459000600012 ()30776265 (PubMedID)2-s2.0-85061778147 (Scopus ID)
Available from: 2019-02-26 Created: 2019-02-26 Last updated: 2019-04-29Bibliographically approved
Myburgh, H. C., Jose, S., Swanepoel, D. W. & Laurent, C. (2018). Towards low cost automated smartphone- and cloud-based otitis media diagnosis. Biomedical Signal Processing and Control, 39, 34-52
Open this publication in new window or tab >>Towards low cost automated smartphone- and cloud-based otitis media diagnosis
2018 (English)In: Biomedical Signal Processing and Control, ISSN 1746-8094, E-ISSN 1746-8108, Vol. 39, p. 34-52Article in journal (Refereed) Published
Abstract [en]

Odds media is one of the most common childhood illnesses. Access to ear specialists and specialist equipment is rudimentary in many third world countries, and general practitioners do not always have enough experience in diagnosing the different otitis medias. In this paper a system recently proposed by three of the authors for automated diagnosis of middle ear pathology, or otitis media, is extended to enable the use of the system on a smartphone with an Internet connection. In addition, a neural network is also proposed in the current system as a classifier, and compared to a decision tree similar to what was proposed before. The system is able to diagnose with high accuracy (1) a normal tympanic membrane, (2) obstructing wax or foreign bodies in the external ear canal (W/O), (3) acute otitis media (AOM), (4) otitis media with effusion (OME) and (5) chronic suppurative otitis media (CSOM). The average classification accuracy of the proposed system is 81.58% (decision tree) and 86.84% (neural network) for images captured with commercial video-otoscopes, using 80% of the 389 images for training, and 20% for testing and validation. 

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Otitis media, Image processing, Feature extraction, Decision tree, Neural network, Otoscope, Tympanic membrane
National Category
Otorhinolaryngology
Identifiers
urn:nbn:se:umu:diva-152144 (URN)10.1016/j.bspc.2017.07.015 (DOI)000412607900004 ()
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2019-08-26Bibliographically approved
Lundberg, T., de Jager, L. B., Swanepoel, D. W. & Laurent, C. (2017). Diagnostic accuracy of a general practitioner with video-otoscopy collected by a health care facilitator compared to traditional otoscopy. International Journal of Pediatric Otorhinolaryngology, 99, 49-53
Open this publication in new window or tab >>Diagnostic accuracy of a general practitioner with video-otoscopy collected by a health care facilitator compared to traditional otoscopy
2017 (English)In: International Journal of Pediatric Otorhinolaryngology, ISSN 0165-5876, E-ISSN 1872-8464, Vol. 99, p. 49-53Article in journal (Refereed) Published
Abstract [en]

Objective: Video-otoscopy is rapidly developing as a new method to diagnose common ear disease and can be performed by trained health care facilitators as well as by clinicians. This study aimed to compare remote asynchronous assessments of video-otoscopy with otoscopy performed by a general practitioner. Method: Children, aged 2-16 years, attending a health center in Johannesburg, South Africa, were examined. An otologist performed otomicroscopy and a general practitioner performed otoscopy. Video-otoscopy was performed by a health care facilitator and video sequences were stored on a server for assessment by the same general practitioner 4 and 8 weeks later. At all examinations, a diagnosis was set and the tympanic membrane appearance was graded using the OMgrade-scale. The otologist's otomicroscopic diagnosis was set as reference standard to compare the accuracy of the two otoscopic methods. Results: Diagnostic agreement between otologist's otomicroscopic examination and the general practitioner's otoscopic examination was substantial (kappa 0.66). Agreement between onsite otomicroscopy and the general practitioners asynchronous video assessments were also substantial (kappa 0.70 and 0.80). Conclusion: Video-otoscopy performed by a health care facilitator and assessed asynchronously by a general practitioner had similar or better accuracy compared to face-to-face otoscopy performed by a general practitioner.

Place, publisher, year, edition, pages
ELSEVIER IRELAND LTD, 2017
Keywords
Otoscopy, Video-otoscopy, Otitis media, General practice, Telemedicine
National Category
General Practice
Identifiers
urn:nbn:se:umu:diva-138589 (URN)10.1016/j.ijporl.2017.04.045 (DOI)000406729400010 ()28688565 (PubMedID)
Available from: 2017-09-21 Created: 2017-09-21 Last updated: 2018-06-09Bibliographically approved
Opheim, L. R., Hellman, U., Engström-Laurent, A. & Laurent, C. (2016). Hyaluronan in Human Vocal Folds in Smokers and Nonsmokers: A Histochemical Study. Journal of Voice, 30(3), 255-262
Open this publication in new window or tab >>Hyaluronan in Human Vocal Folds in Smokers and Nonsmokers: A Histochemical Study
2016 (English)In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 30, no 3, p. 255-262Article in journal (Refereed) Published
Abstract [en]

OBJECTIVES/HYPOTHESIS: To study the hyaluronan occurrence in human vocal folds, with special regards to gender and smoking and to discuss the implications of findings.

STUDY DESIGN: This is a descriptive/morphologic study.

METHODS: Sixteen cadaveric vocal folds from eight individuals between 58 and 90 years old (six women and two men) were removed and studied morphologically. Three of the individuals had been cigarette smokers. A direct method for hyaluronan histochemistry using a hyaluronan-binding protein probe (HABP) was used to visualize the polysaccharide. Five examiners performed an analysis of the intensities of hyaluronan staining, independently.

RESULTS: We observed intense hyaluronan staining of the vocal folds of which those from women stained considerably stronger than those from men. Stratified squamous epithelium stained for hyaluronan in all sections, whereas respiratory epithelium only stained weakly or not at all. The highest accumulation of hyaluronan occurred subepithelially in the lamina propria, corresponding to Reinke's space. It was observed that vocal folds from smokers were more intensively stained than those from nonsmokers.

CONCLUSIONS: Hyaluronan is found in all layers of the human vocal fold. Contradictory to earlier studies, hyaluronan was visualized in squamous epithelium, where it may function as an impact protector. The occurrence of hyaluronan in smokers may have implications in the development of vocal fold inflammation and tumor initiation as hyaluronan is an important molecule in these processes.

Keywords
Vocal folds, Hyaluronan, Smoking, Cigarette, Histochemistry
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-111028 (URN)10.1016/j.jvoice.2015.05.007 (DOI)000376232400002 ()26471808 (PubMedID)
Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2018-06-07Bibliographically approved
Myburgh, H. C., van Zijl, W. H., Swanepoel, D., Hellstrom, S. & Laurent, C. (2016). Otitis Media Diagnosis for Developing Countries Using Tympanic Membrane Image-Analysis. EBioMedicine, 5, 156-160
Open this publication in new window or tab >>Otitis Media Diagnosis for Developing Countries Using Tympanic Membrane Image-Analysis
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2016 (English)In: EBioMedicine, ISSN 0360-0637, E-ISSN 2352-3964, Vol. 5, p. 156-160Article in journal (Refereed) Published
Abstract [en]

Background: Otitis media is one of the most common childhood diseases worldwide, but because of lack of doctors and health personnel in developing countries it is often misdiagnosed or not diagnosed at all. This may lead to serious, and life-threatening complications. There is, thus a need for an automated computer based image-analyzing system that could assist in making accurate otitis media diagnoses anywhere. Methods: A method for automated diagnosis of otitis media is proposed. The method uses image-processing techniques to classify otitis media. The system is trained using high quality pre-assessed images of tympanic membranes, captured by digital video-otoscopes, and classifies undiagnosed images into five otitis media categories based on predefined signs. Several verification tests analyzed the classification capability of the method. Findings: An accuracy of 80.6% was achieved for images taken with commercial video-otoscopes, while an accuracy of 78.7% was achieved for images captured on-site with a low cost custom-made video-otoscope. Interpretation: The high accuracy of the proposed otitis media classification system compares well with the classification accuracy of general practitioners and pediatricians (similar to 64% to 80%) using traditional otoscopes, and therefore holds promise for the future in making automated diagnosis of otitis media in medically underserved populations. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Keywords
Decision tree, Feature extraction, Automated diagnosis, Otitis media, Video-otoscope, Global medicine
National Category
Pediatrics
Identifiers
urn:nbn:se:umu:diva-121597 (URN)10.1016/j.ebiom.2016.02.017 (DOI)000375078200029 ()27077122 (PubMedID)
Available from: 2016-06-21 Created: 2016-06-03 Last updated: 2018-06-07Bibliographically approved
Sandström, J., Swanepoel, D. W., Carel Myburgh, H. & Laurent, C. (2016). Smartphone threshold audiometry in underserved primary health-care contexts. International Journal of Audiology, 55(4), 232-238
Open this publication in new window or tab >>Smartphone threshold audiometry in underserved primary health-care contexts
2016 (English)In: International Journal of Audiology, ISSN 1499-2027, E-ISSN 1708-8186, Vol. 55, no 4, p. 232-238Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE: To validate a calibrated smartphone-based hearing test in a sound booth environment and in primary health-care clinics.

DESIGN: A repeated-measure within-subject study design was employed whereby air-conduction hearing thresholds determined by smartphone-based audiometry was compared to conventional audiometry in a sound booth and a primary health-care clinic environment.

STUDY SAMPLE: A total of 94 subjects (mean age 41 years ± 17.6 SD and range 18-88; 64% female) were assessed of whom 64 were tested in the sound booth and 30 within primary health-care clinics without a booth.

RESULTS: In the sound booth 63.4% of conventional and smartphone thresholds indicated normal hearing (≤15 dBHL). Conventional thresholds exceeding 15 dB HL corresponded to smartphone thresholds within ≤10 dB in 80.6% of cases with an average threshold difference of -1.6 dB ± 9.9 SD. In primary health-care clinics 13.7% of conventional and smartphone thresholds indicated normal hearing (≤15 dBHL). Conventional thresholds exceeding 15 dBHL corresponded to smartphone thresholds within ≤10 dB in 92.9% of cases with an average threshold difference of -1.0 dB ± 7.1 SD.

CONCLUSIONS: Accurate air-conduction audiometry can be conducted in a sound booth and without a sound booth in an underserved community health-care clinic using a smartphone.

Keywords
mHealth, automated audiometer, Audiometry, smartphone, air conduction, ambient noise
National Category
Otorhinolaryngology Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-114789 (URN)10.3109/14992027.2015.1124294 (DOI)000371744400005 ()26795898 (PubMedID)
Available from: 2016-01-28 Created: 2016-01-28 Last updated: 2018-06-07Bibliographically approved
Laurent, C. & Hörnsten, J. (2014). Hörselskadlig examination: [Examination harmful for the hearing]. Läkartidningen, 111(15)
Open this publication in new window or tab >>Hörselskadlig examination: [Examination harmful for the hearing]
2014 (Swedish)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 111, no 15Article in journal (Other academic) Published
National Category
Otorhinolaryngology
Identifiers
urn:nbn:se:umu:diva-118493 (URN)24864518 (PubMedID)
Available from: 2016-04-04 Created: 2016-03-21 Last updated: 2018-06-07Bibliographically approved
Biagio, L., Swanepoel, D. W., Laurent, C. & Lundberg, T. (2014). Paediatric otitis media at a primary healthcare clinic in South Africa. SAMJ South African Medical Journal, 104(6), 431-435
Open this publication in new window or tab >>Paediatric otitis media at a primary healthcare clinic in South Africa
2014 (English)In: SAMJ South African Medical Journal, ISSN 0256-9574, E-ISSN 2078-5135, Vol. 104, no 6, p. 431-435Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: No published studies on the prevalence of paediatric otitis media at primary healthcare clinics (PHCs) in South Africa (SA) are available. OBJECTIVE: To examine the point prevalence of otitis media in a paediatric population in a PHC in Johannesburg, SA, using otomicroscopy. METHODS: A sample of 140 children aged 2 - 16 years (mean 6.4; 44.1% females) were recruited from patients attending the PHC. Otomicroscopy was completed for each of the participants' ears by a specialist otologist using a surgical microscope. RESULTS: Cerumen removal was necessary in 36.0% of participants (23.5% of ears). Otitis media with effusion was the most frequent diagnosis (16.5%). Chronic suppurative otitis media (CSOM) was diagnosed in 6.6% of children and was the most common type of otitis media in participants aged 6 - 15 years. Acute otitis media was only diagnosed in the younger 2 - 5-year age group (1.7%). Otitis media was significantly more prevalent among younger (31.4%) than older children (16.7%). CONCLUSION: CSOM prevalence, as classified by the World Health Organization, was high. Consequently diagnosis, treatment and subsequent referral protocols may need to be reviewed to prevent CSOM complications.

National Category
Pediatrics Otorhinolaryngology
Identifiers
urn:nbn:se:umu:diva-91863 (URN)10.7196/SAMJ.7534 (DOI)000339090300019 ()
Available from: 2014-08-19 Created: 2014-08-18 Last updated: 2018-06-07Bibliographically approved
Lundberg, T., Biagio, L., Laurent, C., Sandström, H. & Swanepoel, D. W. (2014). Remote evaluation of video-otoscopy recordings in an unselected pediatric population with an otitis media scale. International Journal of Pediatric Otorhinolaryngology, 78(9), 1489-1495
Open this publication in new window or tab >>Remote evaluation of video-otoscopy recordings in an unselected pediatric population with an otitis media scale
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2014 (English)In: International Journal of Pediatric Otorhinolaryngology, ISSN 0165-5876, E-ISSN 1872-8464, Vol. 78, no 9, p. 1489-1495Article in journal (Refereed) Published
Abstract [en]

Background: A recently validated image-based grading scale for acute otitis media (OMGRADE) can be used to assess tympanic membrane (TM) status. The aim of this study was to evaluate the validity and reliability of this scale for remote assessments of TM status using video-otoscopy recordings in an unselected pediatric population.

Method: Children 2-16 years attending a South African primary health clinic were offered an ear examination by an otologist using otomicroscopy. An ear and hearing telehealth facilitator then made video-otoscopy recordings (9 – 33 seconds) of the ears and uptakes were uploaded to a secure server for remote assessments in Sweden by an otologist and general practitioner at four- and eight-weeks post onsite assessment. TM appearance was judged according to the OMGRADE scale. Concordance between onsite otomicroscopy and asynchronous assessments of video-otoscopy recordings was calculated together with intra- and inter-rater agreements.

Results: One hundred and eighty ears were included. Concordance of TM classifications using the OMGRADE scale was found to be substantial (weighted kappa range 0,66-0,79). Intra- and inter-rater agreement (test-retest) was found to be substantial to almost perfect (weighted kappa range 0,85-0,88 and 0,69-0,72, respectively).

Conclusion: The OMGRADE scale can be used to accurately assess the normal TM and secretory otitis media (SOM) remotely using video-otoscopy recordings in an unselected pediatric population.

National Category
Otorhinolaryngology
Research subject
Family Medicine; Oto-Rhino-Laryngology
Identifiers
urn:nbn:se:umu:diva-86947 (URN)10.1016/j.ijporl.2014.06.018 (DOI)000340983500016 ()
Available from: 2014-03-13 Created: 2014-03-13 Last updated: 2018-06-08Bibliographically approved
Biagio, L., Swanepoel, D. W., Laurent, C. & Lundberg, T. (2014). Video-otoscopy recordings for diagnosis of childhood ear disease using telehealth at primary health care level. Journal of Telemedicine and Telecare, 20(6), 300-306
Open this publication in new window or tab >>Video-otoscopy recordings for diagnosis of childhood ear disease using telehealth at primary health care level
2014 (English)In: Journal of Telemedicine and Telecare, ISSN 1357-633X, E-ISSN 1758-1109, Journal of telemedicine and telecare, ISSN 1758-1109, Vol. 20, no 6, p. 300-306Article in journal (Refereed) Published
Abstract [en]

We studied the diagnoses made by an otologist and general practitioner (GP) from video-otoscopy recordings on children made by a telehealth facilitator. The gold standard was otomicroscopy by an experienced otologist. A total of 140 children (mean age 6.4 years; 44% female) were recruited from a primary health care clinic. Otomicroscopic examination was performed by an otologist. Video-otoscopy recordings were assigned random numbers and stored on a server. Four and eight weeks later, an otologist and a GP independently graded and made a diagnosis from each video recording. The otologist rated the quality of the video-otoscopy recordings as acceptable or better in 87% of cases. A diagnosis could not be made from the video-otoscopy recordings in 18% of ears in which successful onsite otomicroscopy was conducted. There was substantial agreement between diagnoses made from video-otoscopy recordings and those from onsite otomicroscopy (first review: otologist κ = 0.70 and GP κ = 0.68; second review: otologist κ = 0.74 and GP κ = 0.75). There was also substantial inter-rater agreement (κ = 0.74 and 0.74 at the two reviews) and intra-rater agreement (κ = 0.77 and 0.74 for otologist and GP, respectively). A telehealth facilitator, with limited training, can acquire video-otoscopy recordings in children for asynchronous diagnosis. Remote diagnosis was similar to face-to-face diagnosis in inter- and intra-rater variability.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:umu:diva-96720 (URN)10.1177/1357633X14541038 (DOI)000340600700002 ()24958356 (PubMedID)
Available from: 2014-11-27 Created: 2014-11-27 Last updated: 2018-06-07Bibliographically approved
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