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F G Dikkers

Publications and source records attributed to F G Dikkers.

At least 19 recordsLinked to original sources
PubMed2002

Phonosurgery of the vocal folds: a classification proposal.

The Phonosurgery Committee of the European Laryngological Society (ELS) has examined the definition and technical description of phonosurgical procedures. Based on this review, the committee has proposed a working classification. The current presentation is restricted to vocal fold surgery (VFS) with phonosurgical intent. Both the pathology and the therapeutic aim define VFS: (1). vocal fold lesions that impair vibratory movements require excision (e.g., vocal fold nodule), incision and suction (e.g., Reinke's edema), dissection and/or augmentation (e.g., sulcus-vergeture), coagulation or vaporization (e.g., varicosity) and incision and stenting (e.g., glottal web); (2.vocal fold movement disorders require position and/or tension correction by augmentation (e.g., vocal fold paresis), injection (e.g., botulinum toxin for spasmodic dysphonia) and excision (e.g., dysphonia plicae ventricularis). This presentation excludes surgical instrumentation, implants or injectable materials. Being essentially surgeon-dependent, usage may vary over time and with experience.

Humans↗
PubMed2002

Identification of a 52 kb deletion downstream of the SOST gene in patients with van Buchem disease.

Van Buchem disease is an autosomal recessive skeletal dysplasia characterised by generalised bone overgrowth, predominantly in the skull and mandible. Clinical complications including facial nerve palsy, optic atrophy, and impaired hearing occur in most patients. These features are very similar to those of sclerosteosis and the two conditions are only differentiated by the hand malformations and the tall stature appearing in sclerosteosis. Using an extended Dutch inbred van Buchem family and two inbred sclerosteosis families, we mapped both disease genes to the same region on chromosome 17q12-q21, supporting the hypothesis that van Buchem disease and sclerosteosis are caused by mutations in the same gene. In a previous study, we positionally cloned a novel gene, called SOST, from the linkage interval and identified three different, homozygous mutations in the SOST gene in sclerosteosis patients leading to loss of function of the underlying protein. The present study focuses on the identification of a 52 kb deletion in all patients from the van Buchem family. The deletion, which results from a homologous recombination between Alu sequences, starts approximately 35 kb downstream of the SOST gene. Since no evidence was found for the presence of a gene within the deleted region, we hypothesise that the presence of the deletion leads to a down regulation of the transcription of the SOST gene by a cis regulatory action or a position effect.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Increased bone density in sclerosteosis is due to the deficiency of a novel secreted protein (SOST).

Sclerosteosis is a progressive sclerosing bone dysplasia with an autosomal recessive mode of inheritance. Radiologically, it is characterized by a generalized hyperostosis and sclerosis leading to a markedly thickened and sclerotic skull, with mandible, ribs, clavicles and all long bones also being affected. Due to narrowing of the foramina of the cranial nerves, facial nerve palsy, hearing loss and atrophy of the optic nerves can occur. Sclerosteosis is clinically and radiologically very similar to van Buchem disease, mainly differentiated by hand malformations and a large stature in sclerosteosis patients. By linkage analysis in one extended van Buchem family and two consanguineous sclerosteosis families we previously mapped both disease genes to the same chromosomal 17q12-q21 region, supporting the hypothesis that both conditions are caused by mutations in the same gene. After reducing the disease critical region to approximately 1 Mb, we used the positional cloning strategy to identify the SOST gene, which is mutated in sclerosteosis patients. This new gene encodes a protein with a signal peptide for secretion and a cysteine-knot motif. Two nonsense mutations and one splice site mutation were identified in sclerosteosis patients, but no mutations were found in a fourth sclerosteosis patient nor in the patients from the van Buchem family. As the three disease-causing mutations lead to loss of function of the SOST protein resulting in the formation of massive amounts of normal bone throughout life, the physiological role of SOST is most likely the suppression of bone formation. Therefore, this gene might become an important tool in the development of therapeutic strategies for osteoporosis.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Localization of the gene for sclerosteosis to the van Buchem disease-gene region on chromosome 17q12-q21.

Sclerosteosis is an uncommon, autosomal recessive, progressive, sclerosing, bone dysplasia characterized by generalized osteosclerosis and hyperostosis of the skeleton, affecting mainly the skull and mandible. In most patients this causes facial paralysis and hearing loss. Other features are gigantism and hand abnormalities. In the present study, linkage analysis in two consanguineous families with sclerosteosis resulted in the assignment of the sclerosteosis gene to chromosome 17q12-q21. This region was analyzed because of the recent assignment to this chromosomal region of the gene causing van Buchem disease, a rare autosomal recessive condition with a hyperostosis similar to sclerosteosis. Because of the clinical similarities between sclerosteosis and van Buchem disease, it has previously been suggested that both conditions might be caused by mutations in the same gene. Our study now provides genetic evidence for this hypothesis.

Adult↗
PubMed1999

Lamina propria of the mucosa of benign lesions of the vocal folds.

OBJECTIVE/HYPOTHESIS: To demonstrate a correlation between the duration and specific pattern of trauma of benign lesions of the vocal folds and their histopathologic appearance. Benign lesions of the vocal folds have various macroscopic appearances. Investigations demonstrate characteristic histopathologic features for three clinically well-defined lesions: 1) vocal fold polyps, 2) Reinke edema, and 3) vocal fold nodules. It is expected that additional histological stainings can contribute to additional insight into the pathophysiology of these lesions. STUDY DESIGN: Retrospective. METHODS: Histological stainings were used to study the constitution of the lamina propria of the mucosa: Verhoeff-van Gieson, Masson trichrome, alcian blue and alcian blue after pretreatment with hyaluronidase. RESULTS: Estimation of the age of a lesion was not possible. Specific observations: 1) accumulation of hyaluronic acid around vessels occurred uniquely in polyps and 2) transverse orientation of elastic fibers was more often seen in vocal fold nodules. Combinations of histopathologic findings were specific to the lesion. CONCLUSIONS: The additional stainings support our previous observations, but had no additional discriminating value in making a histopathologic diagnosis.

Basement Membrane↗
PubMed1998

[The immobile vocal cord].

Usually dysphonia is the result of a functional disorder of the larynx. It can also result from paresis or paralysis of a hemilarynx. Four patients, men aged 57, 41, 42 and 18 years, had a neurological cause of paralysis of a hemilarynx. Processes responsible for this kind of pathology can appear at three different levels: central, nuclear and peripheral. Each of the four patients had a disorder at the peripheral level: two had a tumour, in one the vagus nerve was severed during lobectomy for squamous cell carcinoma (iatrogenic), and in the last one an upper respiratory viral infection was the probable cause. Other causes of these peripheral lesions are toxicological, traumatic or idiopathic. When dysphonia does not improve within three weeks, inspection of the larynx and palpation of the neck, including examination of the aspect and mobility of the vocal folds by an otorhinolaryngologist should be performed. If paresis of a hemilarynx is seen, an orientation examination of the cranial nerves and selective additional examination is necessary, as paresis of a hemilarynx is a symptom, not a diagnosis.

Adolescent↗
PubMed1998

[Fixation of facial and auricular prosthesis with osseous implants in cranial bone].

OBJECTIVE: To evaluate the use of osseointegrated implants to fix facial and auricular prostheses. DESIGN: Retrospective. SETTING: University Hospital Groningen, the Netherlands. METHODS: Thirty patients were treated with Brånemark implants for fixation of auricular (21 patients) and orbital (9 patients) prostheses during May 1988-December 1995. The complications during the procedure, the success rate of the implants, skin reactions around the implants and patient satisfaction were recorded. RESULTS: A total of 97 implants were placed. One implant had to be removed after the healing period because it was loose. No other implants were lost during the follow-up period (mean 36 months; range: 12-91). The skin around the implants sometimes showed a mild reaction which could be adequately treated. In most of the cases no inflammation of the skin was observed. Retention, ease of handling and wearing comfort of the facial prostheses were excellent. CONCLUSION: Fixation of facial and auricular prostheses can be improved by osseointegrated implants resulting in high patient satisfaction.

Adolescent↗
PubMed1998

Van Buchem disease (hyperostosis corticalis generalisata) maps to chromosome 17q12-q21.

Van Buchem disease (hyperostosis corticalis generalisata; OMIM 239100 [http://www3.ncbi.nlm.nih. gov:80/htbin-post/Omim/dispmim?239100]) is an autosomal recessive disorder characterized by hyperostosis of the skull, mandible, clavicles, ribs, and diaphyseal cortices of the long bones. The most striking clinical features are the enlargement of the jaw and the thickness of the skull, which may lead to facial nerve palsy, hearing loss, and optic atrophy. Increased formation, by osteoblasts, of qualitatively normal bone has been proposed as the underlying pathological mechanism, but the molecular defect is unknown. We studied 11 van Buchem patients and their highly inbred family, who live in The Netherlands in a small ethnic isolate, that had a common ancestor approximately 9 generations ago. A genomewide search with highly polymorphic microsatellite markers showed linkage to marker D17S1299 on chromosome 17q12-21 (maximum LOD score of 8.82 at a recombination fraction [straight theta] of .01). Analysis of additional markers from that region delineated a candidate region of <1 cM, between markers D17S1787 and D17S934. Interestingly, the only marker not showing recombination with the disease locus was an intragenic marker of the thyroid-hormone receptor alpha1 (THRA1) gene, which generated a LOD score of 12.84 at straight theta=.00. Since thyroid hormones are known to stimulate bone resorption, the THRA1 gene might be involved in the etiology and pathogenesis of van Buchem disease. Unraveling the underlying mechanism for this disorder could contribute to the understanding of the regulatory processes conditioning bone density and the underlying pathological processes.

Chromosome Mapping↗
PubMed1995

[Children with a presumably isolated speech-language disorder often have medical or cognitive problems as well].

OBJECTIVE: To assess the language problems of children who otherwise appear to develop normally. DESIGN: A clinical inventory. SETTING: University Hospital Groningen. METHOD: The children (n = 319) were examined according to a standard protocol consisting of: ENT examination, audiologic examination, paedogogic observation and logopaedic examination. Further psychological examination was carried out when needed according to the paedagogic observation. RESULTS: 25 per cent of the children had isolated language problems. For these children logopaedic therapy was indicated. In 75 per cent, a clear associated medical factor, or a retarded cognitive and (or) motor development, was found. Forty per cent of these children received medical treatment and 35 per cent specific paedagogic guidance. In some cases additional logopaedic therapy was given. CONCLUSION: It appears advisable to give children with language problems logopaedic therapy only after a diagnostic examination has been carried out according to a standard protocol as described.

Child↗
PubMed1995

Thyroplasty to improve the voice in patients with a unilateral vocal fold paralysis.

Unilateral vocal fold paralysis may cause incomplete closure of the glottis and a poor voice. Thyroplasty is a relative new operation to improve the voice by 'medialization' of the paralysed vocal fold. In our series of 29 patients 24 (83%) were satisfied and 26 (90%) had a better voice. After the operation the voice was louder, clearer and easier to understand. The dynamic and melodic ranges on the phonetogram were wider; maximum loudness and maximum phonation time were improved. There were no complications during the follow-up of 4 months to 5 years. In the three patients whose voice was not improved, the vocal fold paralysis was due to local trauma and scarring.

Adult↗
PubMed1995

Benign lesions of the vocal folds: histopathology and phonotrauma.

Benign lesions of the vocal folds have various appearances. Histopathologic examination might provide the true diagnosis. Therefore, histologic slides of 74 patients (92 vocal folds) with clinically well-defined diagnoses were single-blind examined by a pathologist. Single histologic features did not differentiate between different clinical entities, but combinations make some diagnoses more likely than others. Ultrastructural examination of submucosal vessels in the three most common clinical entities (polyps, Reinke edema, and vocal fold nodules) showed an entity-unique pattern of abnormal increase of layers of basement membrane-like material. A potential pathogenetic model of benign lesions of the vocal folds is presented, employing a combination of histopathologic findings and their possible relations with various forms of trauma inducing and maintaining these lesions.

Adolescent↗
PubMed1994

Suspension microlaryngoscopic surgery and indirect microlaryngostroboscopic surgery for benign lesions of the vocal folds.

A prospective study was designed to compare the effects on voice capacities after either suspension microlaryngoscopic surgery or indirect microlaryngostroboscopic surgery. Patients where the clinical diagnosis 'dysphonia due to a benign lesion of the vocal fold' was made, and who could be operated in either way, entered the study. Post-operative voice evaluation was performed on 21 patients after suspension microlaryngoscopic or indirect microlaryngostroboscopic surgery. The long-term voice results following indirect microlaryngostroboscopic surgery and suspension microlaryngoscopic surgery demonstrate a statistically significant improvement for the maximum intensity, maximum dynamic intensity range, dynamic intensity range at habitual speaking pitch, and melodic pitch range. In selected cases indirect microlaryngostroboscopic surgery offers a very good functional result.

Adolescent↗
PubMed1994

Hearing loss and the Mayer-Rokitansky-Küster-Hauser syndrome.

The hearing of 51 female patients with the Mayer-Rokitansky-Küster-Hauser syndrome was examined using otoscopy and standard audiometry. A unilateral or bilateral hearing loss of more than 15 dB Fletcher index was found in 13 of 51 (25.5%). Four of these 13 patients had a hearing loss of less than 20 dB in the worst ear. The remainder had a hearing loss of at least 30 dB in the worst ear. Five of the 13 patients had pure conductive hearing loss; in four of these five, a congenital origin was accepted. Two of the 13 had mixed hearing loss that was a residual symptom from previous otitis media; six had sensorineural hearing loss. A congenital cause was found in one of these six, based on the fact that she had been deaf and dumb since birth. In one other patient, noise-related deafness was likely (i.e., an acquired cause). In the other four cases in this group, the cause was unknown. The results of this study show that hearing loss is a characteristic associated with the Mayer-Rokitansky-Küster-Hauser syndrome.

Adult↗