Biomedical subjects

O Ribári

Publications and source records attributed to O Ribári.

At least 19 recordsLinked to original sources

PubMed1997

[Diagnostic value of tumor markers in ENT oncology].

Control serum samples of young, healthy volunteers (N = 5) were compared with serum samples and laryngeal cancer extracts of patients (N = 12) with stage 3 and 4 cancers. Eight patients were primarily treated by total laryngectomy, 4 patient by palliative irradiation therapy (60 Gy). Ethanol (80%, pH 2) extracts of sera and cancer specimen were gel chromatographed, and the nominally 0.3-5 KDa molecular mass substances were further examined by analytical capillary isotachophoresis (ITP) (LKB. Sweden). Serum samples were also examined after surgery of irradiation therapy. Serum and tumor extracts of each laryngeal cancer patient contained a substance in the molecular mass range of 0.3-5 kDa. This was not detected in the serum of normal control subjects. The marker-candidate substance disappeared from the serum of four out of 8 laryngectomized patients who live tumor-free for years. Recurrence or lymph node metastasis developed in three of the remaining four patients who did not become free of the marker substance after laryngectomy. The concentration of the marker has been increased in the serum after palliative irradiation in all four patients. This marker substance is probably a product of tumor necrosis. The marker may adequately monitor the recurrence of tumor postoperatively of after irradiation therapy.

Aged↗

PubMed1997

Comparative results with different cochlear implants.

The cochlear implant program in Budapest began in 1985, since when 60 operations have been performed, 14 of them on children (51 primary procedures and 9 reimplantations). Different devices and also different techniques have been used: extracochlear promontory, extracochlear round window and intracochlear implants. Various speech processors were applied; at first a digital pulsatile sound-encoding system, later on analog processors were used, while processors operating on the basis of the CIS strategy are preferred nowadays. The operations were performed on both pre- and postlingual patients. In several cases contralateral hearing improvement was observed 6 months after the operation. Considerable experience has been gained of unique cases, such as a deaf-blind prelingual child and prelingual twins. Evaluating cochlear implant performance, in addition to the usual audiological tests measuring postoperative speech understanding, warble tone sound field thresholds were also established.

Adolescent↗

PubMed1997

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↗

PubMed1997

Search for prognostic factors in head and neck cancer.

Fifteen patients with head and neck carcinoma were treated with irradiation (14-70 Gy telecobalt). Apoptotic and mitotic index, DNA index, ratio of cells in S phase, p53 protein overexpression in untreated tumours as well as the changes of these parameters after the first 2 Gy irradiation except proliferative kinetics parameters were examined in order to determine the prognostic value of these factors. The data show that inducibility of apoptosis is very low in head and neck carcinomas which correlate with the unfavourable prognosis. The decrease in mitotic index after the first 2 Gy irradiation, which occurred in 7 cases--5 of them still alive--indicates a better chance for relatively longer survival. In immunohistochemically p53 positive tumours frequently occurring aneuploidy and elevated S-phase rate were found.

Adult↗

PubMed1996

[Etiology, investigation and therapy of facial nerve palsy].

The authors give a description of the causes of the peripheral facial palsy (traumas, viral and bacterial infections, tumors and palsies of unknown origin). Emphasis is given to those anamnestic data, which are useful in the differential diagnostic procedure. Diagnostic methods (modern otologic investigation technics, imaging methods, electrodiagnostic tests), which may help in the precise diagnosis, are discussed. Authors survey the guidelines in the medical and surgical treatment, as well as the electrotherapy of the peripheral facial palsy. The prognostic factors of the disease are also discussed. The author's opinion, that the effectiveness of the treatment is good, and consequently to treat the patients is necessary, and gives high success rate to the doctor.

Diagnosis, Differential↗

PubMed1996

[Cochlear implants].

Cochlear implantation is a method of utmost importance recently employed in ear surgery. It makes even speech understanding possible with electrical stimulation of the inner ear in case of bilateral total deafness of cochlear origin. The authors have performed cochlear implantation for 10 years at the Ear-Nose and Throat Clinic of Semmelweis University. Since 1985 different implantation techniques have been used in case of 58 patients, both adults and children. The authors give account of of technical details, rapidly changing selection criteria and the call attention to the problems of peri- and postoperative period and rehabilitation, on they basis of their own results. Importance of team-work of the ear-surgeon, audiologist, psychologist, physicist and speech-therapist is emphasized, because success of the operation is based on proper selection, skillful operating techniques and postoperative rehabilitation, as well.

Cochlear Implants↗

PubMed1996

Otoacoustic emissions: a new tool for monitoring intracranial pressure changes through stapes displacements.

Changes in hydrostatic intracranial pressure (ICP) are thought to be transmitted to cochlear liquids, thereby altering the mechanical load on the stapes footplate. Hence the stiffness of stapes' annular ligament is expected to reflect ICP changes. Corresponding middle-ear transmission changes have been assessed using click-evoked otoacoustic emissions (EOAE) in two experiments. The first one was performed in 22 normal human subjects submitted to posture changes. In the second one, controlled ICP increases were applied to 18 patients in neurosurgery operating theater. EOAEs were monitored in these subjects throughout the experiments and their phases and amplitudes were analyzed as a function of frequency. ICP affected EOAEs in a systematic manner in both experiments, i.e., the main effect of ICP increase was phase lead of EOAE components below 2 kHz without any significant amplitude or frequency shift. Their variations were much more evident than the modifications in middle-ear impedance assessed by standard impedance or admittance measurements. The second experiment led to a quantitative linear relationship between ICP and EOAE phases. It demonstrated that the sensitivity of EOAE phase monitoring technique proves to be quite high, i.e., 55 daPa increases in ICP are readily detected in all subjects. The results are consistent with the predictions of classical middle-ear models as to the transmission alterations induced by ICP-related changes in the stiffness of the annular ligament of the stapes. Non-invasive monitoring of ICP in patients with hydrocephalus treated with ventriculo-peritoneal shunts might be attempted with this technique, although it is restricted to patients with detectable EOAEs (i.e., about 50% in this series).

Acoustic Stimulation↗

PubMed1996

Cochlear implants in children.

The authors give an account of their experiences with cochlear implants on the basis of 10 years' work. Preoperative evaluation, operating methods and postoperative rehabilitation are presented. During a decade 56 operations were performed, 11 of them on children. Results with prelingually deaf children are demonstrated together with the phenomenon of hearing improvement observed on the contralateral side of the operation.

Child, Preschool↗

PubMed1995

Cochlear implantation improves hearing in the contralateral ear.

The electrical stimulation of deaf ears by cochlear implants (CI) improved contralateral hearing in seven patients: 5 intracochlear (IC) (analogue processor) and 2 extracochlear (EC) (digital processor) implants. Our patients obtained best speech discrimination scores (98% + 2%, n = 11) when lip reading and CI were combined with a high-power hearing aid fitted into the contralateral ear. Contralateral hearing improvement was 10-15 dB sound pressure level (SPL) at frequencies up to 4000 Hz; hearing in a previously totally deaf ear recovered 4-6 months after CI. The phenomenon was independent of the type of speech-encoding (analogue or digital). Five out of 6 reimplanted patients who first received an 8-channel digital-pulsatile EC reported better speech discrimination after the second CI, when IC devices were implanted with analogue speech processors. These results suggest that EC implantation should be considered in childhood as a first choice, since i) It does not exclude the possibility of a second IC implantation with the same success rate as for the first; ii) The inner ear sensory epithelium remains intact after EC implantation, and consequently, if any regenerating process takes place in the implanted ear due to electrical stimulation it may provide more physiological hearing later on.

Audiometry, Pure-Tone↗

PubMed1995

Flavonoids alter bone-remodelling in auditory ossicle organ cultures.

The beneficial role of bioflavonoids in an otosclerosis-like bone-remodelling process can be implicated from its interference with bone resorption induced by prostaglandin E2 (PGE2) in cultured guinea pig ossicles. Ipriflavone (7-isopropoxy-isoflavon) and quercetin reduced PGE2-elevated collagenase-like peptidase (Cl-peptidase) activity and potentiated a PGE2-induced decrease in collagen synthesis. The fact that PGE2 effects are mediated through cyclic AMP in bone turnover and flavonoids act synergistically with PGE2 in collagen synthesis confirm a cyclic AMP phosphodiesterase inhibitory role of flavonoids. It has already been attempted to use Ipriflavone medical treatment of otosclerosis. Quercetin, which has a better than Ipriflavone water-solubility seems as promising as Ipriflavone in the control of the otosclerotic bone-remodelling disturbance.

Animals↗

PubMed1993

A peptide-like putative marker substance of laryngeal cancer patients.

Acidic ethanol precipitation, gel-filtration chromatography (Sephadex G-25) and capillary isotachophoresis were performed on serum and tumor tissue samples from eight patients with stage III and IV laryngeal cancers. An anionic 0.3-5 kDA molecular mass substance that was probably peptide was recorded in both the serum and cancer tissue, but could not be shown in the serum of five control subjects. This substance disappeared from the sera of four patients after total laryngectomy and they have now lived without tumor recurrence for about 2 years. Three of the other four patients developed tumor recurrences while one patient has remained tumor-free. Our findings support a hypothesis that the peptide-like molecule is characteristic of laryngeal cancer and can possibly be used for monitoring the disease.

Adolescent↗

PubMed1992

[Otoacoustic emission audiometry in neonates and adults].

The authors discuss the clinical use of the otoacoustic emission audiometry. During the physiological process of sound amplification in the cochlea vibration energy escapes from the inner ear. By the analysis of this sound it is possible to gain information about the function of the cochlea. According to the experiences of the authors the method is extremely useful for screening audiometry in pathological and normal neonates. In adults it can be used for monitoring the cochlear function during ototoxic therapy or noise exposure.

Adolescent↗

PubMed1992

Hearing improvement achieved by different cochlear implantation techniques on the same and contralateral ears.

The authors have performed cochlear implantation since 1985. Different implantation techniques have been used: extracochlear, round window and intracochlear implantation combined with different receivers. Right at the beginning, the 8-channel extra-cochlear implant produces good results due to the gradually increasing current needed to obtain the same effectivity (transduction energy). However, no great differences can be observed in speech reception whether round window or intracochlear implants be used. In addition to audiological results, we briefly outline surgical implantation techniques and implant fixation methods and summarize the outlook for long-term cochlear implantation. Six months after operation, contralateral hearing was observed. The hearing presented itself at one or two frequences.

Auditory Threshold↗

PubMed1991

Oversulfated mucopolysaccharides in the otosclerotic bone.

Mucopolysaccharides (glucosaminoglycans, GAGs) were extracted from otosclerotic and non-otosclerotic human stapes footplate, stapes superstructure and guinea pig stapes footplate. Cellulose acetate electrophoresis revealed an unknown highly anionic band (Rf = 1.05) beside the conventional hyaluronic acid, chondroitin sulfate and heparan sulfate fractions. Chemical analysis resulted in a high sulfate/hexosamine molar ratio in the otosclerotic GAG extract (1.7 and 1.9) and a very low ratio in non-otosclerotic human stapes and normal guinea pig stapes footplate GAG extract (0.20 and 0.21, respectively). Hexuronic acid content was highest in guinea pig stapes GAG preparation. Our results serve as indirect evidence of the presence of an oversulfated GAG fraction in the otosclerotic bone, which can potentially initiate otosclerotic bone resorption.

Animals↗

PubMed1991

Operative treatment of malformations of the middle ear.

The authors give a review of their experience with the surgical treatment of developmental disorders of the middle ear. They introduce to the findings and surgical solutions in the tympanum of their cases. In shaping the acoustic meatus they recommend the closed approach developed by Marguet.

Adolescent↗

PubMed1989

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↗

PubMed1988

The barrier-like role of activated connective tissue against the spread of supraglottic laryngeal carcinoma.

Light microscopic investigations of whole organ serial sections of 15 laryngectomy specimens with supraglottic carcinomas and comparative electron microscopic studies of the upper and lower poles of the tumors were carried out. The ultrastructure of different poles of the same supraglottic tumors was investigated and showed a more progressive fibrillogenesis with an activation of the connective tissue elements of the border on the lower pole of the malignancy. A significant role is attributed to the barrier-forming feature of activated connective tissue with respect to the inhibition of the extension of tumor into the glottic region.

Carcinoma, Squamous Cell↗

PubMed1987

Proteolytic enzymes in otosclerosis. Significance of proteolytic enzymes in otosclerotic bone remodelling.

The otosclerotic stapes footplate exhibits higher activities of cathepsin D and H and collagenase-like peptidase than those of normal cortical bone. The elevated enzyme activities of osteoblastic origin (Cl-peptidase and cathepsin D) emphasize the essential and probably primary role of the bone-forming cells, not only in bone formation, but in resorption as well. The highest activity of cathepsin D from among the measured enzymes highlights the adjuvant role of acidic glucosaminoglycans in the otosclerotic demineralization process. As the osteoblastic osteoid synthesis is known to be sharply reduced in otosclerotic bone remodelling, and the above data emphasize the role of proteolytic enzymes of osteoblastic origin too, indirectly, osteoblasts seem to be the otosclerosis signal-transducing cells.

Bone Development↗