Histamine metabolism is altered in nasal polyposis.
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Chromatography, High Pressure Liquid↗
Biomedical subjects
A Hirschberg
Publications and source records attributed to A Hirschberg.
Simplified models of flue instruments: influence of mouth geometry on the sound source.
Flue instruments such as the recorder flute and the transverse flute have different mouth geometries and acoustical response. The effect of the mouth geometry is studied by considering the aeroacoustical response of a simple whistle. The labium of a transverse flute has a large edge angle (60 degrees) compared to that of a recorder flute (15 degrees). Furthermore, the ratio W/h of the mouth width W to the jet thickness h can be varied in the transverse flute (lips of the musician) while it is fixed to a value W/h approximately 4 in a recorder flute. A systematic experimental study of the steady oscillation behavior has been carried out. Results of acoustical pressure measurements and flow visualization are presented. The sharp edge of the recorder provides a sound source which is rich in harmonics at the cost of stability. The larger angle of the labium of the flute seems to be motivated by a better stability of the oscillations for thick jets but could also be motivated by a reduction of broadband turbulence noise. We propose two simplified sound source models which could be used for sound synthesis: a jet-drive model for W/h>2 and a discrete-vortex model for W/h<2.
Journal Article↗
Unsteady flow through in-vitro models of the glottis.
The unsteady two-dimensional flow through fixed rigid in vitro models of the glottis is studied in some detail to validate a more accurate model based on the prediction of boundary-layer separation. The study is restricted to the flow phenomena occurring within the glottis and does not include effects of vocal-fold movement on the flow. Pressure measurements have been carried out for a transient flow through a rigid scale model of the glottis. The rigid model with a fixed geometry driven by an unsteady pressure is used in order to achieve a high accuracy in the specification of the geometry of the glottis. The experimental study is focused on flow phenomena as they might occur in the glottis, such as the asymmetry of the flow due to the Coanda effect and the transition to turbulent flow. It was found that both effects need a relatively long time to establish themselves and are therefore unlikely to occur during the production of normal voiced speech when the glottis closes completely during part of the oscillation cycle. It is shown that when the flow is still laminar and symmetric the prediction of the boundary-layer model and the measurement of the pressure drop from the throat of the glottis to the exit of the glottis agree within 40%. Results of the boundary-layer model are compared with a two-dimensional vortex-blob method for viscous flow. The difference between the results of the simpiflied boundary-layer model and the experimental results is explained by an additional pressure difference between the separation point and the far field within the jet downstream of the separation point. The influence of the movement of the vocal folds on our conclusions is still unclear.
Air Pressure↗
Influence of collision on the flow through in-vitro rigid models of the vocal folds.
Measurements of pressure in oscillating rigid replicas of vocal folds are presented. The pressure upstream of the replica is used as input to various theoretical approximations to predict the pressure within the glottis. As the vocal folds collide the classical quasisteady boundary layer theory fails. It appears however that for physiologically reasonable shapes of the replicas, viscous effects are more important than the influence of the flow unsteadiness due to the wall movement. A simple model based on a quasisteady Bernoulli equation corrected for viscous effect, combined with a simple boundary layer separation model does globally predict the observed pressure behavior.
Air Pressure↗
Quasisteady aero-acoustic response of orifices.
The low frequency response of orifices (slit, circular diaphragm, and perforated plate) in the presence of mean flow is well predicted by a quasisteady theory. A refinement is brought to the theory by considering a Mach number dependent vena contracta coefficient. The measurements of the vena contracta coefficient of a slit agree well with the simple analytical expression existing in the case of the Borda tube orifice. The measured scattering matrix coefficients do not depend strongly on the geometry of the element. If the frequency is increased the moduli remain relatively unaffected while the arguments exhibit a complex behavior which depends on the geometry. From these considerations an anechoic termination efficient at high mass flow is designed.
Journal Article↗
[Effectiveness and tolerability of the glucocorticoid mometasone furoate given as nasal spray in seasonal allergic rhinitis].
The clinical effect and tolerance of momethasone furoate (MF) glucocorticoid nasal spray (MFNS) were studied in 14-70 year-old patients suffering from seasonal allergic rhinitis. The patients administered daily one (morning) dose, 100 micrograms each, of MF into both nostrils, for a period of 14 days. They did not use other medicines affecting nasal symptoms. Nasal symptoms (nasal discharge, nasal obstruction, nasal itching, sneezing) and non-nasal symptoms (lacrimation, eye itching/burning sensation, palatal itching, ear itching, general itching), scored 0 to 3, and serving as a basis for evaluating the effect, were registered before treatment (day 1) and at visits on 3, 7 and 14th day. Of the 196 patients involved in the open multicentric study, 188 completed the study. The total average nasal symptom scores decreased, already after 3 days of treatment, from 8.7 to 4.1 and to 1.6 by the 14th day. Decrease of non-nasal symptoms was also conspicuous, however, lacrimation persisted in 57 of 188 cases, while eye itching--mainly in moderate and mild form--in 90 cases. The general condition of rhinitis before the treatment was evaluated by the examiners as severe or very severe in 155 cases (82%), as symptom-free (99 cases) on day 14 in, and mild (71 cases), in 170 cases (90%). The therapeutic effect was considered by both, patients and physician, as excellent, in 106 (56%) and 115 (61%) cases, resp. and as good in 63 (34%) and 56 cases (30%). Side-effects were mostly mild and transitory. Treatment was not discontinued due to side-effect in any of the cases. Based on the results, MFNS, administered in a single daily dose of 200 micrograms, has proved to be an effective and safe glucocorticoid preparation, also easy to use locally, in the treatment of allergic rhinitis.
Administration, Intranasal↗
Laser surgery of the vocal cord.
A total of 1032 vocal cord operations have been performed by means of CO2 laser in the Department of Otorhinolaryngology, Head and Neck Surgery of the Semmelweis University of Medicine in Budapest in the past 10 years. There were 687 benign cases and 345 malignant cases of lesions discovered. The procedures were performed under general anesthesia in many instances with jet narcosis--in laryngomicroscopic exposure. The operations were preceded by careful objective diagnostics, such as videolaryngostroboscopy, fiberoscopy, voice analysis, airflow and resistance measurements, while the voice and breathing functions were monitored postoperatively. Our policy in the therapy of the benign lesions was always to use a minimally invasive technique, avoiding damage to the anterior commissure, the vocal ligament and the subglottic space. We have experienced a 3-year survival rate in 87% of the patients with vocal cord carcinomas. According to the results of the past 10 years it is proven that the CO2 laser technique is an efficient method as well in the surgery of the benign and malignant vocal cord lesions, as in the bilateral vocal cord paralysis. Laser surgery might also prevent malignant transformation in precancerous vocal cord diseases.
Humans↗
The central odontogenic fibroma and the hyperplastic dental follicle: study with Picrosirius red and polarizing microscopy.
The central odontogenic fibroma (COF) is an uncommon odontogenic tumor in which the microscopic appearance is similar to that of the hyperplastic dental follicle (HDF). Distinction between these lesions is based mainly on their clinical and radiologic features. The collagen of 5 cases of COF and 13 cases of HDF was studied histochemically by staining sections with Picrosirius red and examining them by polarizing microscopy. Polarization colors of the collagen fibers of the lesions were recorded according to their width. While no differences were seen between the polarization colors of thin fibers (<0.8 mm) in both lesions, the polarization colors of thick fibers (1.6-2 mm) of COF were significantly more green and greenish-yellow as compared with those of HDF. These findings suggest that the Picrosirius red polarization method can be used as a diagnostic tool to differentiate between COF and HDF..
Azo Compounds↗
[Trauma resuscitation--a new perspective].
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Humans↗
Pharyngeal airflow during sleep.
This study was conducted to investigate the effects of sleep and nasal resistance on pharyngeal airflow in a group of healthy male adults without complaint of habitual snoring. Twelve subjects aged 21 to 60 years were studied in a sleep laboratory during exclusive nasal breathing. Nasal and pharyngeal airflow variables were measured concomitantly at different stages of sleep. Awake pharyngeal resistance averaged 0.02-0.03 Pa/cm3/s in recumbency. In stage 2 sleep and quiet breathing resistance increased by a factor of 3-4 and by a factor of 7-8 during snoring. Increased nasal loading did not increase pharyngeal resistance further or induce snoring. Mostly, increased pharyngeal resistances were of similar magnitude in both phases of respiration, but in a few instances inspiratory resistance exceeded that in expiration, and in a similar number the reverse was found. Overall, compliance of the pharyngeal airway was not a prominent feature in this group of subjects. The relationship between transpharyngeal pressure and resistance should be studied further in order to simplify future studies of airflow during sleep.
Adult↗
The airflow resistance profile of healthy nasal cavities.
Distribution of resistance to respiratory airflow in the nasal cavities was determined by digitized pressure/flow measurements of consecutive 2-cm airway segments between nostril and nasopharynx. Healthy adult subjects seated in a head-out body plethysmograph breathed exclusively through a single nasal cavity while transnasal pressure and flow signals were transduced, digitized and processed by a programmed desk-top computer to provide resistance values. Mean total resistances of untreated and decongested single nasal cavities were 0.44 (n = 30; SD +/- 0.25) and 0.26 (n = 15; SD +/- 0.06) Pa/cm3/s, respectively. The proportion of total airway resistance of successive 2-cm segments from nostril to nasopharynx was 56%, 22%, 16%, and 6% in the untreated nose, and 88%, 5%, 2%, and 5% following decongestion. The findings from 45 nasal cavities are consistent with previous pressure/flow measurements from six nasal cavities and support recent acoustic reflection assessments of nasal cross-sectional areas of both untreated and decongested noses.
Adolescent↗
Connective tissue nevi collagens. Study with picrosirius red and polarizing microscopy.
Biopsy specimens of five connective tissue nevi were examined under crossed polars after staining with Picrosirius red. One biopsy specimen was from a solitary nevus, another from a Shagreen patch. The other three specimens were of erupted nevi. In all cases, thick (as well as thin) collagen fibers appeared green to yellow. In contrast, thick fibers of normal human dermis appeared orange to red. The findings indicate that the collagen of collagenous connective tissue nevi is less well packed than normal collagen. Examination of the polarization colors of Picrosirius red-stained sections is a useful procedure for diagnosing collagenous connective tissue nevi.
Adult↗
Our experiences at Semmelweis University with different techniques and materials in the surgery of chronic otitis media.
Different techniques and materials used in the surgery of chronic otitis media have been evaluated in a large clinical experience at Semmelweis University, Budapest. Data from 1572 operations performed during the last 5 years (1983-1988) are summarized. In the 870 non-cholesteatomatous processes (55.3%), mastoidectomies and tympanoplasties were performed, with the latter primarily using temporalis fascia and cortical bone. Out of the 250 cholesteatoma cases (15.9%), one-fourth was solved by a primary wall-up technique followed by a second stage revision and tympanoplasty within 1.5 years later.
Child↗
Ancient neurilemmoma (Schwannoma) of the oral cavity.
Ancient neurilemmoma is a rare lesion of the oral cavity. The present article describes an additional case and discusses some difficulties in its histological diagnosis. The final diagnosis is based on both light and electron microscopy morphology. Immunohistochemical studies are, at present, only of supportive value.
Female↗
Results obtained with Loderix tablet in chronic rhinitis patients.
The place of histamine among primary mediators in allergic rhinitis and the mechanism of action of antihistamines have been discussed. The use of Loderix was tried in 40 chronic rhinitis patients by the open method. According to the observations the second generation Loderix may be successfully used in allergic rhinitis and "eosinophil" type vasomotor rhinitis cases. The side-effects of Loderix did not differ from those of the other antihistamine products.
Adolescent↗
[Aggressive and selective surgical management of severe peritonitis].
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Humans↗
[Approaches and methods for the evaluation of medical treatment].
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Outcome and Process Assessment, Health Care↗