Andrea Tóth

Differential expression of purinergic receptor subtypes in the outer hair cells of the guinea pig

ATP acts as a neuro-modulator through purinoceptors in many different tissues. Many subtypes of these receptors have been identified in the inner ear, but so far only two types have been shown to be present in the membrane of the isolated outer hair cells (OHCs). The aim of this study was to detect and visualize the existence and distribution of purinoceptor subtypes as well as to study the [Ca(2+)](i) response of these cells in response to stimulation with ATP. Four P2X and three P2Y receptor subtypes were identified with different expression pattern in the membrane of guinea pig outer hair cells. Whereas intense labeling was observed for P2X1, P2X2, P2X4, P2Y1, P2Y2, and P2Y4, the labeling for the subtype P2X7 was weak. There was a marked difference in the distribution of the receptors along the surface of the cells with a homogenous distribution in cases of P2X1, P2X4, and P2Y1. In contrast, P2X2 and P2Y2 receptor density was high mainly at the apical, while P2X7 and P2Y4 at the basal pole of the cells. Similarly a heterogeneity was observed in the ATP-induced transient elevation in [Ca(2+)](i), which had either fast kinetics without desensitization or slow rise with desensitization.

Oviposition preferences of Maculinea alcon as influenced by aphid (Aphis gentianae) and fungal (Puccinia gentianae) infestation of larval host plants

Abstract 1. The influence of infestation of the larval host plant Gentiana cruciata on the egg‐laying preferences of the xerophilous ecotype of Alcon Blue butterfly (Maculinea alcon) was studied in a semi‐dry grassland area (Aggtelek Karst Region, Northern Hungary).

Intrinsic laryngeal muscle reinnervation with nerve-muscle pedicle.

OBJECTIVE: To test the application of the nerve-muscle pedicle (NMP) technique for selective rein-nervation of previously denervated posterior cricoarytenoid (PCA) muscle. METHODS: The left recurrent laryngeal nerve (RLN) was severed in 5 mongrel dogs, and an ansa cervicalis-sternohyoid muscle pedicle was sutured to the left PCA muscle. Three dogs underwent a sham operation. Videolaryngoscopy was performed, and electromyographic data were collected after 1 year on average. Finally, histologic analysis of the NMP was performed. RESULTS: The video records showed the return of mobility of the PCA muscle reinnervated by the NMP. EMG data as to show evoked polyphasic potentials showed also evidence of reinnervation of the PCA muscle. With immunohistochemical reaction (antineurofilament antibody+biotin) we could show neurofilaments and motor endplates in both sides in all 5 animals. CONCLUSIONS: The NMP technique could eliminate the need for arytenoidectomy and laterofixation in patients with unilateral or bilateral vocal fold paralysis. The quality of life and voice may be improved. (Otolaryngol Head Neck Surg 2005;132:701-6.)

Changes in brain activation caused by caloric stimulation in the case of cochleovestibular denervation - PET study

There are a number of well-known stimulation methods for the investigation of the central projection of the vestibular system. In addition to optokinetic, galvanic and neck vibration tests, the most widespread method is caloric stimulation. These listed methods cause not only vestibular, but also other effects on the central nervous system (CNS) (acoustic, tactile and nociceptive). In this paper, positron emission tomography (PET) was used to investigate whether caloric stimulation contains a non-vestibular (extravestibular) component, which would cause a distortion in the cortical activity and therefore in the vestibular effect on the CNS. Caloric stimulation was carried out in six patients who had been operated on due to cerebello-pontine angle tumour. These patients suffered post-operatively from a complete lesion of the vestibular system and anacusis on the operated side. Ipsilaterally activated areas were the inferior pole of the post-central gyrus and temporoparietal junction, caudal part of the post-central gyrus (SI, SII), inferior parietal lobule and medial frontal gyrus. Contralaterally activated areas were the anterior cingulate gyrus, medial frontal gyrus, posterior part of the insula, post-central gyrus and temporoparietal junction (SII). Ipsilaterally deactivated areas were the caudal and cranial part of the medial occipital gyrus (V2, V3, V4, V5). Contralaterally deactivated areas were the lingual gyrus, inferior occipital gyrus (V2, V3) and fusiform gyrus. On the basis of these data, it was postulated that, during caloric stimulation, extravestibular reaction also occurs, which corresponds to the subjective feeling of heat and pain. The deactivation of the occipital cortex due to an extravestibular effect was demonstrated. This is the first observation to suggest the possibility of nociceptivevisual interaction.

Retropharyngeal superficial angiomyxoma

OBJECTIVE To describe the first published case of superficial angiomyxoma with an epithelial component occurring in the retropharynx. METHOD Case report of a patient with swallowing difficulties caused by a rare case of superficial angiomyxoma in the retropharynx. RESULTS Superficial angiomyxoma is a distinct entity among the dermal myxomatous lesions. Superficial angiomyxoma is poorly circumscribed, and local recurrence is common unless the tumour is excised with clear margins. Distinctive histological features include a myxoid mass composed of spindle and stellate-shaped cells and occasional multinucleated cells. There is prominent vasculature and a mixed inflammatory infiltrate in the stroma, particularly by neutrophil polymorphs. Epithelial structures are seen in about one-third of cases. A case of retropharyngeal tumour with morphological features of superficial angiomyxoma is reported. The tumour cells, including multinucleated ones, were negative for soft tissue differentiation markers. The inflammatory cells included lymphocytes, histiocytes and neutrophil polymorphs. CONCLUSION This case demonstrates that a cutaneous type of angiomyxoma with epithelial-lined structures can occur in deep soft tissue, such as the retropharynx.

Recurrent laryngeal nerve paralysis due to subclinical Lyme borreliosis

OBJECTIVE We report an extremely rare case of recurrent laryngeal nerve paralysis due to subclinical Lyme borreliosis. METHOD Case report presenting a 15-year-old girl referred with hoarseness and soft voice. RESULTS Right-sided recurrent laryngeal nerve paralysis was observed using videolaryngoscopy. Imaging was used to exclude intracranial, cervical and intrathoracic embryological lesions, vascular malformations and tumours. Laboratory and electrophysiological investigations were used to exclude inflammatory and paraneoplastic processes, endocrinopathy and metabolic disorders. Serological testing was positive for Lyme disease. Parenteral ceftriaxone therapy was commenced. The patients nerve paralysis showed complete recovery on the seventh day of antibiotic treatment; this was confirmed by videolaryngoscopy. CONCLUSION Recurrent laryngeal nerve paralysis is an extremely rare complication of neuroborreliosis associated with Lyme disease. In patients with recurrent laryngeal nerve paralysis in whom the clinical history is uncertain and the usual diagnostic methods give negative results, screening with anti-borrelia immunoglobulin M is suggested.

Osteogenic differentiation of human lens epithelial cells might contribute to lens calcification

Calcification of the human lens has been described in senile cataracts and in young patients with congenital cataract or chronic uveitis. Lens calcification is also a major complication of cataract surgery and plays a role in the opacification of intraocular lenses. A cell-mediated process has been suggested in the background of lens calcification, but so far the exact mechanism remained unexplored. Lens calcification shares remarkable similarities with vascular calcification; in both pathological processes hydroxyapatite accumulates in the soft tissue. Vascular calcification is a regulated, cell-mediated process in which vascular cells undergo osteogenic differentiation. Our objective was to investigate whether human lens epithelial cells (HuLECs) can undergo osteogenic transition in vitro, and whether this process contributes to lens calcification. We used inorganic phosphate (Pi) and Ca to stimulate osteogenic differentiation of HuLECs. Osteogenic stimuli (2.5mmol/L Pi and 1.2mmol/L Ca) induced extracellular matrix mineralization and Ca deposition in HuLECs with the critical involvement of active Pi uptake. Osteogenic stimuli almost doubled mRNA expressions of osteo-/chondrogenic transcription factors Runx2 and Sox9, which was accompanied by a 1.9-fold increase in Runx2 and a 5.5-fold increase in Sox9 protein expressions. Osteogenic stimuli induced mRNA and protein expressions of alkaline phosphatase and osteocalcin in HuLEC. Ca content was higher in human cataractous lenses, compared to non-cataractous controls (n=10). Osteocalcin, an osteoblast-specific protein, was expressed in 2 out of 10 cataractous lenses. We conclude that osteogenic stimuli induce osteogenic differentiation of HuLECs and propose that this mechanism might play a role in lens calcification.

Regional pattern of genetic variation in the Eastern Central European populations of Euphydryas maturna (Lepidoptera: Nymphalidae)

The aim of this study was to delineate functional conservation units (FCUs) in Scarce Fritillary Euphydryas maturna (Linnaeus, 1758) populations in eastern Central Europe. We analyzed the level and structure of genetic variation using allozymes as markers in 26 Scarce Fritillary populations originating from nine geographic regions. Considering the reproductive strategy of E. maturna, we assumed that populations are strongly exposed to genetic drift. Accordingly, we hypothesized: (i) A low level of genetic variation within populations, and; (ii) A high level of differentiation among them with little evidence of geographic pattern. The results of this study mostly fulfilled our expectations: (i) Scarce Fritillary populations of eastern Central Europe exhibited a relatively low level of polymorphism at investigated enzyme loci, and; (ii) Comparatively strong differentiation was detected among populations. As opposed to our expectation, however, a more-or-less clear pattern of differentiation was revealed by the results of our Bayesian-clustering analysis. Four genetic regions were distinguished on the basis of their average cluster membership coefficients, specifically Dobrogea (Romania), North and East Hungary (composed of four geographic regions), Central and West Hungary (involving three geographic regions), and Transylvania. Three of these genetic regions were previously distinguished as separate subspecies, comprising E. maturna idunides (Central and West Hungary), E. maturna partiensis (North and East Hungary including Transylvania), and E. maturna opulenta (Dobrogea, Romania). These three putative subspecies can be considered as Scarce Fritillary FCUs in eastern Central Europe.

Induction of NLRP3 Inflammasome Activation by Heme in Human Endothelial Cells

Hemolytic or hemorrhagic episodes are often associated with inflammation even when infectious agents are absent suggesting that red blood cells (RBCs) release damage-associated molecular patterns (DAMPs). DAMPs activate immune and nonimmune cells through pattern recognition receptors. Heme, released from RBCs, is a DAMP and induces IL-1β production through the activation of the nucleotide-binding domain and leucine-rich repeat-containing family and pyrin domain containing 3 (NLRP3) in macrophages; however, other cellular targets of heme-mediated inflammasome activation were not investigated. Because of their location, endothelial cells can be largely exposed to RBC-derived DAMPs; therefore, we investigated whether heme and other hemoglobin- (Hb-) derived species induce NLRP3 inflammasome activation in these cells. We found that heme upregulated NLRP3 expression and induced active IL-1β production in human umbilical vein endothelial cells (HUVECs). LPS priming largely amplified the heme-mediated production of IL-1β. Heme administration into C57BL/6 mice induced caspase-1 activation and cleavage of IL-1β which was not observed in NLRP3−/− mice. Unfettered production of reactive oxygen species played a critical role in heme-mediated NLRP3 activation. Activation of NLRP3 by heme required structural integrity of the heme molecule, as neither protoporphyrin IX nor iron-induced IL-1β production. Neither naive nor oxidized forms of Hb were able to induce IL-1β production in HUVECs. Our results identified endothelial cells as a target of heme-mediated NLRP3 activation that can contribute to the inflammation triggered by sterile hemolysis. Thus, understanding the characteristics and cellular counterparts of RBC-derived DAMPs might allow us to identify new therapeutic targets for hemolytic diseases.

The role of the different neoglottis forms in the development of esophageal voice.

UNLABELLED Evaluation of voice quality parameters of esophageal speech in different neoglottis forms after total laryngectomy. METHODS Presentation of voice analysis of 20 patients, who underwent total laryngectomy. The success of acquiring this technique was estimated by means of a voice analyzing program (pitch, sound-holding, loudness, spectrogram),and by the intelligibility via the telephone. Shape of the different types of neoglottis that developed and its functioning during vocalization and continuous speech were observed by nasal endoscopy. Data obtained from the voice analysis were compared among the observed three different neoglottis forms. RESULTS The average dysphonia index of the 20 patients was 1.67 ± 0.38 (mean ± SD). Nasal fiberoscopic examination revealed three different types of neoglottis forms – a small mucosal button, two mucosal battens, and a mucosal lip. Voice quality of the esophageal speech of the patients with the mucosal button was found to be the closest to normal by subjective and objective acoustical evaluation. CONCLUSIONS These findings emphasize the importance of the proper wound closure technique which can facilitate the development of a special button shape neoglottis form and help to acquire esophageal speech with the best quality parameters shortly after total laryngectomy.