Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Eur Arch Otorhinolaryngol ; 280(4): 1671-1676, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36115871

RESUMEN

PURPOSE: Our objective is to evaluate the effect of habituation on the altered ear canal acoustics after canal wall down mastoidectomy. METHODS: A total of 11 participants with single sided dry cavities and normal contralateral ear canals with normal hearing thresholds were included in the study. Filtered sound fragments were created that simulate the different acoustic properties based on the participants Real Ear to Coupler Difference (RECD) of the cavity ear and the contralateral normal ear canal. These filtered sound fragments are presented to the cavity ear canal and the contralateral normal ear canal using inserts earphones. Participants performed a subjective quality assessment of the sound fragments using paired comparison with a seven-point scale (- 3 till + 3). RESULTS: Mean assessment of sound quality revealed the following results; naturalness of sounds of the cavity ear canal is 0.29 (± 1.41; ns) in favour of the filtered sound fragment of the normal ear canal. Mean assessment of sharpness of sounds in the cavity ear canal is 1.55 (± 1.21, p = 0.55) in favour of the filtered sound fragment of the normal ear canal. Overall preference in the cavity ear canal was in favour of the normal ear canal acoustics 0.72 (SD ± 1.54 p = 0.224). CONCLUSIONS: Patients with cavity ear canals seem to habituate to their altered ear canal acoustics. Transforming the ear canal acoustics of the cavity ear to normal ear canal acoustics seem to sharpen the incoming sounds. Overall assessment of quality of sound of the normal ear canal acoustics is better than the cavity acoustics.


Asunto(s)
Habituación Psicofisiológica , Mastoidectomía , Humanos , Acústica , Audición , Sonido , Conducto Auditivo Externo/cirugía
2.
J Laryngol Otol ; 135(5): 410-414, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33883045

RESUMEN

OBJECTIVE: This study aimed to compare the necessary scutum defect for transmeatal visualisation of middle-ear landmarks between an endoscopic and microscopic approach. METHOD: Human cadaveric heads were used. In group 1, middle-ear landmarks were visualised by endoscope (group 1 endoscopic approach) and subsequently by microscope (group 1 microscopic approach following endoscopy). In group 2, landmarks were visualised solely microscopically (group 2 microscopic approach). The amount of resected bone was evaluated via computed tomography scans. RESULTS: In the group 1 endoscopic approach, a median of 6.84 mm3 bone was resected. No statistically significant difference (Mann-Whitney U test, p = 0.163, U = 49.000) was found between the group 1 microscopic approach following endoscopy (median 17.84 mm3) and the group 2 microscopic approach (median 20.08 mm3), so these were combined. The difference between the group 1 endoscopic approach and the group 1 microscopic approach following endoscopy plus group 2 microscopic approach (median 18.16 mm3) was statistically significant (Mann-Whitney U test, p < 0.001, U = 18.000). CONCLUSION: This study showed that endoscopic transmeatal visualisation of middle-ear landmarks preserves more of the bony scutum than a microscopic transmeatal approach.


Asunto(s)
Oído Medio/diagnóstico por imagen , Oído Medio/cirugía , Endoscopía , Microcirugia , Procedimientos Quirúrgicos Otológicos , Cadáver , Humanos , Imagenología Tridimensional , Tomografía Computarizada por Rayos X
3.
Eur Arch Otorhinolaryngol ; 277(9): 2455-2462, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32335711

RESUMEN

PURPOSE: To correlate the subjective quality assessment of ear canal acoustics of the participants to the objective measurement of the ear canal acoustics. The objective ear canal acoustics is the frequency-dependent modulation of soundwaves through the ear canal. Our second objective is to design a model to predict the subjective quality of sound based on the altered objective ear canal acoustics. METHODS: To determine the frequency-dependent modulation of the soundwaves the real-ear unaided gain (REUG) of the ear canal is measured. 40 participants with normal hearing were presented six simulated sound fragments representing the acoustic properties of six different ear canals (REUG). These six sound fragments were built based on the difference between these six REUGs and the average REUG of a normal adult ear canal. Subjective sound quality was evaluated using a VAS score and a paired comparison score. RESULTS: We found a strong correlation between the objective ear canal acoustics and the subjective assessment of the quality of sound (Spearman's rho-0.89). Our linear mixed VAS model for individual participants has an intercept of 95.6 and a slope of - 4.2 (p < 0.001). The paired comparison analysis endorsed our findings that an increased difference in REUG is predictive for a decreased quality assessment of ear canal acoustics. CONCLUSION: There is a strong correlation between the subjective evaluation of ear canal acoustics and the objective quality assessment of ear canal acoustics. Our models show that an increased difference in REUG predicts a decreased quality of ear canal acoustics.


Asunto(s)
Conducto Auditivo Externo , Procedimientos Quirúrgicos Otológicos , Acústica , Adulto , Pruebas Auditivas , Humanos , Sonido
4.
Health Qual Life Outcomes ; 17(1): 105, 2019 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-31215443

RESUMEN

BACKGROUND: To validate and evaluate the reliability of the Dutch version of the Chronic Ear Survey (CES) in patients suffering from Chronic Suppurative Otitis Media (CSOM) and to evaluate clinical outcomes of surgery using this questionnaire. METHODS: We developed the Dutch version of the CES (D-CES) using forward-backward translation of the original CES into the Dutch language. Next, patients with CSOM and controls completed the D-CES pre- and postoperatively. Internal consistency, test-retest reliability, known-group validity and convergent validity were evaluated. In addition to the D-CES, the Short Form 36 (SF-36) was administered to all participants to correlate D-CES data to quality of life. RESULTS: A total of 29 patients with CSOM scheduled for ear surgery were included. Our control group consisted of 26 patients scheduled for eye surgery, all without signs and symptoms of CSOM. Cronbachs' α of the complete questionnaire was 0.69. The Intraclass Correlation Coefficients (ICCs), reflecting test-retest reliability, ranged between 0.69 and 0.82. Scores differed significantly between CSOM patients and controls with substantial lower (more impaired) D-CES scores in the CSOM group. Duration of complaints preoperatively and the presence of a dry ear and/or improvement of hearing postoperatively all had a significant impact on D-CES improvement scores. Small to moderate correlations were found between D-CES subscales and matching subscales of the SF-36. CONCLUSION: The D-CES is an appropriate disease specific questionnaire to assess a patient's perceived functional health in CSOM.


Asunto(s)
Otitis Media Supurativa/psicología , Calidad de Vida , Encuestas y Cuestionarios/normas , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos , Otitis Media Supurativa/cirugía , Reproducibilidad de los Resultados , Traducciones , Adulto Joven
5.
Int J Pediatr Otorhinolaryngol ; 102: 56-60, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29106876

RESUMEN

OBJECTIVES: The aim of this study was to review the clinical presentation and early signs and symptoms of otogenic intracranial complications (OIC) in children and adults. METHODS: retrospective chart review. The medical records of all children and adults admitted in our center with OIC during the period 2008-2017 were reviewed. Data concerning clinical presentation, treatment and outcomes were reviewed and analyzed. RESULTS: We included 47 patients with OIC: 21 children (range 1-13 years) and 26 adults (range 22-71 years). We included more patients with acute otitis media than with chronic otitis media (children 5% adults 19%, all with cholesteatoma). In children; the most common OIC was central cerebral venous thrombosis. In both children and adults; otogenic symptoms such as otalgia and otorrhea were present. Children presented more frequently with headache and nausea. Adults presented more frequently with decreased consciousness. Hearing loss was the most common long-term sequel. Three adults died. CONCLUSIONS: In our series, we found that OIC in children present as 'mimicking meningitis' (e.g. nausea and vomiting). Adults on the other hand have a clinical presentation 'mimicking stroke' (e.g. neurological deficits and decreased level of consciousness). In children, sinus thrombosis was observed more frequently than in adults. Despite the low mortality rate, death still occurs. Long -term sequelae most frequently include hearing loss in children as well as in adults.


Asunto(s)
Enfermedades del Sistema Nervioso Central/diagnóstico , Otitis Media/complicaciones , Adolescente , Adulto , Anciano , Enfermedades del Sistema Nervioso Central/etiología , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Otitis Media/diagnóstico , Estudios Retrospectivos
6.
Eur Arch Otorhinolaryngol ; 274(10): 3605-3612, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28799140

RESUMEN

The objective of the study was to evaluate postoperative hearing and disease control after cholesteatoma surgery for labyrinthine fistulas. In a retrospective cohort study, we evaluated a consecutive cohort comprising 44 patients (45 ears) with labyrinthine fistulas associated with chronic otitis media with cholesteatoma who underwent surgery between 2002 and 2015. We looked at patient characteristics, pre- and postoperative bone conduction thresholds (BCT), operative approach and findings, extent of disease and the occurrence of residual disease. All deaf ears (24%) presented preoperatively with a large fistula. Opening the membranous labyrinth resulted in significantly worse postoperative BCT (p = 0.01). Neither the present study nor a literature search revealed a significant positive effect of corticosteroids on postoperative hearing preservation. Large fistulas were correlated with poorer preoperative BCTs, but not with poorer postoperative BCTs. Opening the membranous labyrinth during surgery is correlated with poorer postoperative BCTs and can be seen as a predictive parameter. The use of corticosteroids in the perioperative management of labyrinthine fistula was not found to result in any improvement in postoperative BCTs.


Asunto(s)
Colesteatoma del Oído Medio/complicaciones , Fístula , Pérdida Auditiva , Enfermedades del Laberinto , Otitis Media/complicaciones , Complicaciones Posoperatorias , Conducción Ósea , Oído Interno/patología , Oído Interno/fisiopatología , Oído Interno/cirugía , Femenino , Fístula/etiología , Fístula/cirugía , Glucocorticoides/uso terapéutico , Audición , Pérdida Auditiva/diagnóstico , Pérdida Auditiva/etiología , Pérdida Auditiva/prevención & control , Pruebas Auditivas/métodos , Humanos , Enfermedades del Laberinto/etiología , Enfermedades del Laberinto/cirugía , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/terapia , Estudios Retrospectivos
7.
J Laryngol Otol ; 131(2): 138-143, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28069077

RESUMEN

OBJECTIVE: This study aimed to evaluate the results of revision radical cavity surgery with mastoid obliteration using a standardised grading scheme. METHODS: A retrospective study was performed of 121 patients (122 ears) with chronically draining ears who underwent revision radical cavity surgery with mastoid obliteration between 2007 and 2013. Surgical indications, patient characteristics, pre- and post-operative Merchant grade, and surgical outcomes were recorded. The main outcome measures were presence of a dry ear, time for complete re-epithelialisation, presence of residual or recurrent disease, and need for revision surgery. RESULTS: In the 5-year follow-up group (n = 31), dry ears were found in 97 per cent after 6 minor revisions and cholesteatoma-free ears were found in 97 per cent. In the total cohort, dry ears were found in 93 per cent after nine revisions and cholesteatoma-free ears were found in 98 per cent. The median time for complete re-epithelialisation was eight weeks. There were no major complications. CONCLUSION: In terms of the dry ear rate, residual cholesteatoma and time to complete epithelialisation, revision radical cavity surgery with mastoid obliteration produces very good results in concordance with published results, despite most patients suffering from very troublesome cavities prior to surgery.


Asunto(s)
Colesteatoma del Oído Medio/cirugía , Conducto Auditivo Externo/cirugía , Apófisis Mastoides/cirugía , Timpanoplastia/métodos , Adolescente , Adulto , Anciano , Niño , Enfermedad Crónica , Enfermedades del Oído/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Otológicos/métodos , Reoperación , Estudios Retrospectivos , Adulto Joven
8.
Biochem Pharmacol ; 115: 114-22, 2016 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27297283

RESUMEN

Genetic differences between individuals that affect drug action form a challenge in drug therapy. Many drugs target G protein-coupled receptors (GPCRs), and a number of receptor variants have been noted to impact drug efficacy. This, however, has never been addressed in a systematic way, and, hence, we studied real-life genetic variation of receptor function in personalized cell lines. As a showcase we studied adenosine A2A receptor (A2AR) signaling in lymphoblastoid cell lines (LCLs) derived from a family of four from the Netherlands Twin Register (NTR), using a non-invasive label-free cellular assay. The potency of a partial agonist differed significantly for one individual. Genotype comparison revealed differences in two intron SNPs including rs2236624, which has been associated with caffeine-induced sleep disorders. While further validation is needed to confirm genotype-specific effects, this set-up clearly demonstrated that LCLs are a suitable model system to study genetic influences on A2AR response in particular and GPCR responses in general.


Asunto(s)
Linfocitos B/metabolismo , Receptor de Adenosina A2A/genética , Transducción de Señal , Antagonistas del Receptor de Adenosina A2/metabolismo , Adulto , Línea Celular , Línea Celular Transformada , Niño , Femenino , Genotipo , Humanos , Ligandos , Masculino , Polimorfismo de Nucleótido Simple , Receptor de Adenosina A2A/metabolismo , Gemelos Monocigóticos/genética
9.
Cochlear Implants Int ; 17(3): 146-50, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27078518

RESUMEN

OBJECTIVES: To evaluate the speech discrimination performance of elderly post-lingually deafened cochlear implant (CI) users and the stability of performance over time relative to a control group of younger CI users. METHODS: The study group consisted of 20 native Dutch speaking, post-lingually deafened CI users, aged 70 or older at the time of implantation. Controls were patients aged 40-60 years at implantation and included according to the same inclusion criteria (except age). Linear mixed models assessed speech recognition scores between groups, the variability of their performance, and stability over time. RESULTS: 20 elderly and 37 controls were included. The mean follow-up was 4.4 and 5.3 years for elderly and controls, respectively. There was no significant difference in average speech discrimination between both groups. The elderly group had a larger intra-subject variability over time. There was no significant effect of follow-up on the speech discrimination, indicating a stable performance over time. DISCUSSION: This study has a longer follow-up than methodologically comparable previous studies. We found no difference in speech discrimination between elderly patients and controls and no deterioration of performance over time. The subjects in the elderly group exhibit a larger variability around their mean performance. CONCLUSION: Speech recognition in both elderly and younger adult CI users is stable over time and is not significantly related to the age of implantation.


Asunto(s)
Implantes Cocleares , Sordera/fisiopatología , Percepción del Habla , Tiempo , Adulto , Factores de Edad , Anciano , Estudios de Casos y Controles , Implantación Coclear , Sordera/etiología , Sordera/cirugía , Femenino , Estudios de Seguimiento , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Países Bajos , Periodo Posoperatorio , Resultado del Tratamiento
10.
Eur Arch Otorhinolaryngol ; 273(10): 3143-8, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26920704

RESUMEN

Objective of this work was to evaluate the perceptual effect of the acoustic properties before and after canalplasty and a reconstruction of the posterior canal wall in revision modified radical cavity surgery. This is a prospective study. Twenty normal hearing subjects were presented six simulated sound conditions representing the acoustic properties of six different ear canals (two normal ears, and two pre- and postoperative conditions). The six different real ear unaided responses of these ear canals were used to filter Dutch sentences, resulting in six simulated sound conditions. A seventh unfiltered 'reference' condition was used for comparison. Sound quality was evaluated using a seven-point paired comparison rating and a visual analogue scale (VAS). Significant differences in sound quality were found between all conditions and the pre-operative cavity condition (all p < 0.001) using both the paired comparison rating and VAS. No significant differences in VAS were found comparing the other conditions with each other. But when using the paired comparison rating, the post-operative canalplasty condition and both the pre and post-operative cavity conditions differed significantly from the other conditions. This explorative study shows that altering the acoustics of the OEAC after a canalplasty and a reconstruction of the ear canal in revision modified radical cavity surgery results in perceivable changes in sound quality. It is likely that these changes are primarily due to volume changes. To which extent these changes are of clinical importance remains to be determined.


Asunto(s)
Percepción Auditiva/fisiología , Conducto Auditivo Externo/cirugía , Audición/fisiología , Acústica , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Estudios Prospectivos , Adulto Joven
11.
Eur Arch Otorhinolaryngol ; 271(5): 997-1005, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23632865

RESUMEN

The goal of this work was to review the pre-and postsurgical auditory thresholds of two surgical implantation techniques, namely the mastoidectomy with posterior tympanotomy approach (MPTA) and suprameatal approach (SMA), to determine whether there is a difference in the degree of preservation of residual hearing. In a series of 430 consecutive implanted patients 227 patients had measurable pre-operative hearing thresholds at 250, 500, and 1,000 Hz. These patients were divided into two groups according to the surgical technique that was used for implantation. The SMA approach was followed for 84 patients in Amsterdam, whereas the MPTA technique was adhered to 143 patients in Maastricht. The outcome variables of interest were alteration of pre-and postoperative auditory thresholds after cochlear implantation. Complete or partial preservation of residual hearing was obtained in 21.4 and 21.7% in the SMA and MPTA group, respectively. No statistical differences could be found between the SMA and MPTA group (p = 0.96; Chi-square test). The SMA technique is correlated with a similar degree of hearing loss after cochlear implantation compared to the MPTA technique. However, both techniques were not able to conserve a measurable amount of hearing in patients with a substantial degree of residual hearing. Therefore, both surgical techniques need to be refined for patients in which residual acoustical hearing is pursued.


Asunto(s)
Umbral Auditivo/fisiología , Implantación Coclear/métodos , Complicaciones Posoperatorias/fisiopatología , Audiometría de Tonos Puros , Electrodos Implantados , Humanos , Estudios Retrospectivos , Factores de Riesgo , Estadística como Asunto
12.
Rhinology ; 50(2): 191-8, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22616081

RESUMEN

BACKGROUND: Although the use of the microdebrider (shaver) is well known in endoscopic sinus surgery (FESS), there is lack of evidence from comparative studies focussing on the difference in operating time, intra-operative blood loss and user-friendliness between the microdebrider and traditional operating techniques. In this study we compared the use of the microdebrider to conventional instruments in FESS in these areas. METHODS: A prospective randomised double blind controlled trial in 60 patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) undergoing bilateral FESS. Each subject received FESS using only traditional instruments (Blakseley forceps) on one side and the other side with the additional use of the microdebrider, this way serving as their own control. The primary outcome was operation time, intra-operative blood loss and user friendliness and secondly safety and postoperative healing with a follow-up period at different time points up to three months postoperative. RESULTS: We found a 37% longer operating time when operating without a microdebrider. This difference was highly significant. The microdebrider scored significantly higher on every different parameter of user friendliness, except on the preparation of the instrument needed before surgery. For estimated blood loss during surgery we found no differences. Also there was no significant difference in postoperative healing at any point of time. CONCLUSIONS: This study demonstrates that operating patient with CRSwNP with the microdebrider is efficient and that the microdebrider at the same time is safe and easy to use.


Asunto(s)
Desbridamiento/instrumentación , Endoscopía , Senos Paranasales/cirugía , Adolescente , Adulto , Anciano , Pérdida de Sangre Quirúrgica/estadística & datos numéricos , Método Doble Ciego , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pólipos Nasales/cirugía , Estudios Prospectivos , Recurrencia , Cicatrización de Heridas , Adulto Joven
13.
Rhinology ; 50(1): 22-5, 2012 03.
Artículo en Inglés | MEDLINE | ID: mdl-22469601

RESUMEN

BACKGROUND: The measurement of peak nasal inspiratory flow (PNIF) is a simple, quick, easy to perform and cheap tool for determining the extent of nasal airway patency. However, normative data are rare and not available for Dutch children aged 6 to 11 years. METHODS: Repeated PNIF measurements were obtained from 212 Dutch children of primary school age. Of these 212 children, 166 fulfilled the inclusion criteria of our study. The influence of age, gender, ethnicity, weight and height on PNIF was studied. RESULTS: Age is the only parameter of influence on PNIF. All other parameters do not influence PNIF. Normative data are presented. CONCLUSION: PNIF measurements are possible in children aged six years and older. Age does influence PNIF, but gender, weight, height and ethnicity do not.


Asunto(s)
Inhalación/fisiología , Nariz/fisiología , Ventilación Pulmonar/fisiología , Estatura , Peso Corporal , Niño , Femenino , Humanos , Masculino , Países Bajos , Valores de Referencia
14.
Rhinology ; 47(4): 393-5, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19936365

RESUMEN

INTRODUCTION: In the chronic rhinosinusitis (CRS) definition of the RhinoSinusitis Task Force (RSTF) of the American Academy of Otolaryngology-Head and Neck Surgery, fever is one of the minor symptoms. In the EP3OS definition, fever is not mentioned as a contributing factor. The main aim of this study was to evaluate the role of fever in CRS. PATIENTS AND METHODS: Patients with CRS, scheduled for surgery were compared with a control group consisting of patients without CRS, suffering from esthetic complaints or obstruction of the nose. Temperature prior to surgery was measured and analyzed. RESULTS: In both groups, hundred patients were included. In the CRS group the mean temperature was 36.94 degrees C, with a maximum of 37.8 degrees C. The control group revealed a mean temperature of 36.87 degrees C. Analysis demonstrated no significant difference between the mean temperatures of the CRS patients and the controls (p = 0.306). Additional analysis, correcting for possible confounders, did not reveal significant differences between both groups either. DISCUSSION: There have been several attempts to define CRS in the past, but an all including definition or classification system for this disorder does not currently exist. Fever is a factor under discussion. We found no significant difference between the preoperative body temperature in CRS patients and controls. These results suggest that fever is not a relevant symptom in CRS.


Asunto(s)
Fiebre/etiología , Rinitis/diagnóstico , Sinusitis/diagnóstico , Adolescente , Adulto , Anciano , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
15.
Allergy ; 63(7): 820-33, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18588547

RESUMEN

Nasal congestion is an important symptom in nasal pathology and can be defined as an objective restriction of nasal cavity airflow because of mucosal pathology and/or increased mucus secretion (excluding anatomical variants). Using the new Grading Recommendations Assessment, Development and Evaluation system, evidence-based recommendations are made that will encompass different clinical questions regarding diagnostic modalities of nasal congestion: (i) their usefulness in assessment of presence and severity of congestion; (ii) their usefulness in assessment of etiological pathology responsible for congestion; and (iii) their usefulness in follow up and treatment effectiveness evaluation of nasal congestion.


Asunto(s)
Moco/metabolismo , Mucosa Nasal/metabolismo , Obstrucción Nasal/diagnóstico , Diagnóstico Diferencial , Medicina Basada en la Evidencia , Humanos , Anamnesis , Obstrucción Nasal/fisiopatología , Pruebas de Provocación Nasal , Óxido Nítrico/análisis , Examen Físico , Guías de Práctica Clínica como Asunto , Rinitis/diagnóstico , Rinitis/fisiopatología , Rinomanometría , Rinometría Acústica , Índice de Severidad de la Enfermedad
18.
J Clin Endocrinol Metab ; 86(7): 3359-67, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11443212

RESUMEN

The endometrium is a tissue unique for its cyclic destruction and rapid regeneration of blood vessels. Angiogenesis, indispensable for the regeneration process, provides a richly vascularized, receptive endometrium fundamental for implantation, placentation, and embryogenesis. Human endometrial microvascular endothelial cells (hEMVEC) were isolated to better understand the properties and angiogenic behavior of these cells. Unlike human foreskin microvascular endothelial cells (hFMVEC), which proliferated better upon stimulation by basic fibroblast growth factor, hEMVEC were much more sensitive to vascular endothelial growth factor A (VEGF-A) stimulation, probably due to enhanced VEGF receptor 2 expression. In addition, hEMVEC displayed an enhanced expression of the urokinase-type plasminogen activator (u-PA) compared with hFMVEC. No differences were found in tissue-type PA, PA inhibitor-1, and u-PA receptor expression. The high expression of u-PA by hEMVEC was also found in tissue sections. hEMVEC formed capillary-like structures when cultured in 20% human serum on top of three-dimensional fibrin matrices, and VEGF-A or basic fibroblast growth factor increased this tube formation. This is in contrast with hFMVEC, which formed tubes only after simultaneous stimulation by a growth factor and tumor necrosis factor-alpha. The high basal level of u-PA contributes to and may explain the higher angiogenic properties of hEMVEC (in vitro).


Asunto(s)
Endometrio/irrigación sanguínea , Endotelio Vascular/fisiología , Neovascularización Fisiológica , Activador de Plasminógeno de Tipo Uroquinasa/análisis , Capilares/fisiología , División Celular , Separación Celular , Células Cultivadas , Endometrio/enzimología , Factores de Crecimiento Endotelial/farmacología , Endotelio Vascular/citología , Endotelio Vascular/enzimología , Femenino , Factor 2 de Crecimiento de Fibroblastos/farmacología , Humanos , Ciclo Menstrual , Inhibidor 1 de Activador Plasminogénico/biosíntesis , Activadores Plasminogénicos/biosíntesis , Receptores de Superficie Celular/análisis , Receptores de Superficie Celular/metabolismo , Receptores del Activador de Plasminógeno Tipo Uroquinasa , Activador de Tejido Plasminógeno/biosíntesis , Factor de Necrosis Tumoral alfa/farmacología , Activador de Plasminógeno de Tipo Uroquinasa/biosíntesis , Factor A de Crecimiento Endotelial Vascular
19.
Antonie Van Leeuwenhoek ; 67(3): 243-53, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7778893

RESUMEN

Effects of growth conditions on mitochondrial morphology were studied in living Saccharomyces cerevisiae cells by vital staining with the fluorescent dye dimethyl-aminostyryl-methylpyridinium iodine (DASPMI), fluorescence microscopy, and confocal-scanning laser microscopy. Cells from respiratory, ethanol-grown batch cultures contained a large number of small mitochondria. Conversely, cells from glucose-grown batch cultures, in which metabolism was respiro-fermentative, contained small numbers of large, branched mitochondria. These changes did not significantly affect the fraction of the cellular volume occupied by the mitochondria. Similar differences in mitochondrial morphology were observed in glucose-limited chemostat cultures. In aerobic chemostat cultures, glucose metabolism was strictly respiratory and cells contained a large number of small mitochondria. Anaerobic, fermentative chemostat cultivation resulted in the large, branched mitochondrial structures also seen in glucose-grown batch cultures. Upon aeration of a previously anaerobic chemostat culture, the maximum respiratory capacity increased from 10 to 70 mumole.min-1.g dry weight-1 within 10 h. This transition resulted in drastic changes of mitochondrial number, morphology and, consequently, mitochondrial surface area. These changes continued for several hours after the respiratory capacity had reached its maximum. Cyanide-insensitive oxygen consumption contributed ca. 50% of the total respiratory capacity in anaerobic cultures, but was virtually absent in aerobic cultures. The response of aerobic cultures to oxygen deprivation was qualitatively the reverse of the response of anaerobic cultures to aeration. The results indicate that mitochondrial morphology in S. cerevisiae is closely linked to the metabolic activity of this yeast: conditions that result in repression of respiratory enzymes generally lead to the mitochondrial morphology observed in anaerobically grown, fermenting cells.


Asunto(s)
Mitocondrias/ultraestructura , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/ultraestructura , Aerobiosis , Anaerobiosis , Medios de Cultivo , Etanol/metabolismo , Fermentación , Colorantes Fluorescentes , Glucosa/metabolismo , Microscopía Confocal , Microscopía Fluorescente , Compuestos de Piridinio , Saccharomyces cerevisiae/metabolismo
20.
Biotechnol Bioeng ; 39(3): 343-50, 1992 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-18600951

RESUMEN

An integrated measuring system was developed that directly compares the shape of size distributions of Saccharomyces cerevisiae populations obtained from either microscopic measurements, electronic particle counter, or flow cytometer. Because of its asymmetric mode of growth, a yeast population consists of two different subpopulations, parents and daughters. Although electronic particle counter and flow cytometer represent fast methods to assess the growth state of the population as a whole, the determination of important cell cycle parameters like the fraction of daughters or budded cells requires microscopic observation. We therefore adapted a semiautomatic and interactive 2D-image processing program for rapid and accurate determination of volume distributions of the different sub-populations. The program combines the capacity of image processing and volume calculation by contour-rotation, with the potential of visual evaluation of the cells. High-contrast images from electron micrographs are well suited for image analysis, but the necessary air drying caused the cells to shrink to 35% of their hydrated volume. As an alternative, hydrated cells overstained with the fluorochrome calcofluor and visualized by fluorescence light microscopy were used. Cell volumes calculated from length, and diameter measurements with the assumption of an ellipsoid cell shape were underestimated as compared to volumes derived from 2D-image analysis and contour rotation, because of a deviating cell shape, especially in the older parent cells with more than one bud scar. The bimodal volume distribution obtained from microscopic measurements was identical to the protein distribution measured with the flow cytometer using cells stained with dansylchloride, but differed significantly from the size distribution measured with the electronic particle counter. Compared with the flow cytometer, 2-D image analysis can thus provide accurate distributions with important additional information on, for instance, the distributions of subpopulations like parents, daughters, or budded cells.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA