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K Graamans

Publications and source records attributed to K Graamans.

13 recordsLinked to original sources
PubMed1992

A study of the photoelectrical signal from human nasal cilia under several conditions.

The movement of normal human nasal cilia was analyzed. Ciliary beat was recorded by means of a phase-contrast microscope equipped with a photodetector. The electrical signal was analyzed as follows: i) a power spectrum was calculated in order to measure ciliary beat frequency (CBF), ii) the beat cycles were averaged and the standard deviation of the waveform was computed to determine signal consistency (SC), and iii) the ratio of the duration of the smooth to that of the steep part of the cycles was measured. This was done under three different conditions: 1) normal or "initial", 2) after induction of "function loss", and 3) after "salbutamol stimulation". At "function loss," the cilia beat slower and with less harmony. CBF decreased from an average of 9.0 Hz in the "initial" condition to 5.8 Hz. SC decreased from an average of 5.7 to 1.9. After "salbutamol stimulation", average CBF was partially restored to 7.7 Hz, while average SC increased to 4.4. These findings indicate that in ciliary function studies, SC, as a measure for ciliary beat harmony, may be introduced alongside CBF as a second valuable parameter. In this study we were not able to identify different phases in the signal that might be used as a third parameter to indicate the effective and the recovery stroke.

Albuterol↗
PubMed1992

Influence of sympathetic and parasympathetic substances in clinical concentrations on human nasal ciliary beat.

The effect of autonomic substances on ciliary beat in mucosal biopsies from the normal human nose was studied. The influence on ciliary beat frequency (CBF) as well as on ciliary beat harmony was measured photoelectrically. The sympathetic beta-agonist isoprenaline was found to have a stimulatory effect on CBF, whereas the alpha-agonist xylometazoline reduced CBF and ciliary beat harmony. The parasympathetic agonist carbachol had a positive effect on CBF. The sympathetic antagonists timolol (beta) and phentolamine (alpha) as well as the parasympathetic antagonist atropine had no effect. The effect of the agonists on ciliary beat was absent when they were administered in combination with their specific antagonists. These experiments indicate that, in clinical concentrations, the autonomic substances modify ciliary beat by a direct effect on the ciliated cells.

Adrenergic alpha-Agonists↗
PubMed1991

Sellar granulomatous mass in a pregnant woman with active Crohn's disease.

At the end of her third pregnancy, a woman with a history of chronic active proctocolitis which had been diagnosed as Crohn's disease complained of deterioration of visual acuity. The patient was found to have hypopituitarism and progressive bitemporal hemianopia caused by an intrasellar mass with suprasellar extension. At transsphenoidal surgery an intrasellar granuloma was found without remnants of pituitary tissue. This sellar granuloma could have been an extra-intestinal granuloma of Crohn's disease. However, the possibility that giant cell granulomatous hypophysitis had been present was considered more likely. The occurrence of this disorder in the postpartum period has not been reported before.

Adult↗
PubMed1991

Factors influencing ciliary beat measurements.

Investigation of the effect of environmental and pharmacological factors on human respiratory epithelium requires standardization of measuring conditions. Ciliary beat frequency (CBF) and its shift were determined photo-electrically in 43 biopsies of human nasal mucosa. Curette biopsies were compared to forceps biopsies. CBF variation between three different cells of one biopsy sample did not differ for the two biopsy techniques. The ciliated cells of forceps biopsy specimens showed a more constant beating pattern which resulted in a small CBF shift. It appeared that in studying ciliary activity a continuous layer of ciliated cells which is in contact with the basal membrane is required. Therefore forceps biopsies are preferable to curette biopsies. The environmental temperature has to remain constant since CBF is temperature dependent. The pH and osmolarity of the medium do not influence CBF when kept within a certain range. No effect of medium superfusion flow rate was seen.

Basement Membrane↗
PubMed1990

Ciliary beat frequency and the nasal cycle.

The purpose of this study was to investigate whether the ciliary beat frequency (CBF) is influenced by the nasal cycle. Nasal patency was assessed by active anterior rhinomanometry and immediately followed by measuring CBF in biopsies taken from the posterior aspect of the inferior turbinates in 22 healthy volunteers. CBF was determined in three different cells of each biopsy by means of a phase-contrast microscope and a photo-electrical cell. The signal was analyzed by a computed power spectrum. The frequency and its shift were calculated for a period of 20 s. The results were as follows: (1) no correlation was found between CBF and nasal patency; (2) CBF in one cell is constant to a high degree; (3) CBF of different cells in the same biopsy specimen varies considerably.

Adolescent↗
PubMed1989

[A numb cheek].

Explore the source record for details and available documents.

Cheek↗
PubMed1989

Orbital exenteration in surgery of malignant neoplasms of the paranasal sinuses. The value of preoperative computed tomography.

The extension of paranasal sinus malignant neoplasms into the orbit presents one of the arguments for carrying out orbital exenteration. One method of assessing the extension is computed tomography (CT), but its reliability is still questionable. Therefore, the preoperative CT images were compared with the pathoanatomic features of the surgical specimens in 15 patients who underwent orbital exenteration as part of a procedure for paranasal sinus malignant neoplasm. Ophthalmic symptoms were present in eight patients and in each instance the CT images documented the extension of the tumor accurately. In only four of seven patients without ophthalmic symptoms did CT scanning appear to match the factual situation. Apparently CT scanning is not always reliable in patients without ophthalmic symptoms.

Adult↗
PubMed1988

Transsphenoidal microsurgery as primary treatment in 25 acromegalic patients: results and follow-up.

Twenty-five patients with acromegaly were treated by transsphenoidal microsurgery. Fourteen patients (56%) were considered cured according to the following criteria: a. basal plasma GH less than 10 mU/l; b. glucose suppressed plasma GH less than or equal to 4 mU/l, and c. disappearance of TRH responsiveness if present preoperatively. Thirteen of the cured patients were re-evaluated after a mean follow-up period of 3.5 years (range 1.5 to 5.5 years). At that time, basal plasma GH was still less than 10 mU/l and glucose suppressed plasma GH was still less than or equal to 4 mU/l in all patients, indicating the practical value of our criteria. The remaining 11 patients (44%) received additional treatment by external pituitary irradiation and bromocriptine. Owing to surgery, 5 patients (20%) developed partial or panhypopituitarism.

Acromegaly↗
PubMed1986

Testing ciliary activity in patients with chronic and recurrent infections of the upper airways: experiences in 68 cases.

The clinical use of various tests of ciliary activity is uncertain and the purpose of this study is to assess the practical significance of the most current methods. Therefore, biopsy specimens of the nasal mucosa were investigated by means of phase contrast microscopy in 68 patients with chronic and recurrent infections of the upper airways. In 19 cases an absent or extremely weak ciliary activity could be demonstrated. Ultrastructurally, a characteristic pattern of defective dynein arms as observed in primary ciliary dyskinesia, was evident in only 3 out of these 19 patients. Measurements of the mucociliary transport velocity by means of intranasal Tc 99m labeled particles appeared to be unreliable in cases of severe nasal obstruction. In this study, phase contrast microscopy of biopsy material from the nasal respiratory epithelium appeared to have the most advantages: It is a practical and rather simple screening test in the assessment of ciliary activity.

Adolescent↗
PubMed1976

[Clinical aspects of choanal atresia].

Clinical examination was performed on 10 patients with recently treated choanal atresia, 8 unilateral and 2 bilateral cases. All patients showed an asymmetrical facial skeleton, which could be classified as hemifacial microsomia, although sometimes in a rather subclinical form. In all unilateral cases of choanal atresia hypoplasia of the facial skeleton was manifest on the affected side. These cases did not reveal that choanal atresia can occur without any abnormality in the facial skeleton. Hemifacial microsomia is not only a clinical entity, but also has a distinct pathogenesis. In early embryonic development a trauma occurs in the first or second branchial arch, which causes focal mesenchymal destruction, and this is thought to present the pathogenesis of hemifacial microsomia. Choanal atresia did not always occur with associated orthodontic abnormalities. Clinical examination, however, revealed transversal maxillar compression at the affected side in three out of eight unilateral cases.

Adult↗