[Free radicals and antioxidants in otorhinolaryngology]. / Volné radikály a antioxidanty v otorhinolaryngologii.

Free radicals in otorhinolaryngology participate in the pathogenesis of many diseases. Antioxidants can act or preventively or ameliorate the diseases. Oxidative stress, in which is the predominance of free radicals to antioxidants, is present in many states like inflammation, atherosclerosis or tumors. Antioxidant capacity is increased not only by the application of antioxidants, but also due to positive emotions. In nasal and paranasal diseases is the role of the nitroxide radical very important. Vasocontrictive drugs decrease its level, pathologically increased levels are observed in asthma, allergic rhinitis and in sinusitis. Nitroxide protects organism against microorganisms and viruses. Oxidative stress supports the origin of nasal polyposis, takes part in disturbances of the hearing. Increased reactive oxygen species are engaged in tinnitus. In otitis media the level of lipoperoxides may be the marker of the severity of the disease. In Ménicre's syndrome the total antioxidant capacity is decreased. It is possible to conclude, that free radicals and antioxidants play an important role in otorhinolaryngological diseases.

Congenitally determined neurodegeneration "Lurcher" induces morphofunctional changes of thymus.

A significantly higher frequency of apoptosis was documented by flow cytometry and by ELISA analysis, and significantly higher numbers of necrotic cells were demonstrated by ELISA within the thymus of Lurcher mice in comparison with the control C3H mice. These can be regarded as important markers of degenerative changes in this primary immune organ. This tendency is supported by histological observation of the absence of a clear interface between thymic cortex and medulla and an insignificantly increased number of Hassall's corpuscles resembling an onset of thymic atrophy.

The palatine tonsil as an evolutionary novelty.

The development of the pharyngeal pouches was studied in early human embryos. A vesicular thymus primordium, separated from the lining epithelium of the second pouch, is described in 5-week-old embryo's (9 mm stage). This transitory structure disappeared in the next stage (10 mm). Much later--in the 9th week, the first branched and solid crypt developed in the same region, from the same epithelium, and in a similar way to a gland. This formation then stimulated the lymphocytic infiltration of the connective tissue around the crypt branches in the 13th week. Attention is drawn to the similarity between the closed relation of the salivary glands and the simplest tonsils in lower mammals. These findings prove the original potency of the second pouch to form a thymus as in lower vertebrates, and to form salivary glands as in birds and even lower mammals. They also prove that all these phyletic changes have been imprinted in the human ontogeny, and explain the mutual relations between the palatine tonsil and the thymus in postnatal life.

Development of the pharynx in normal and malformed fetuses.

We studied the development of the pharynx in human embryos and fetuses. Embryos and fetuses from 4.5 mm crown-rump length (CRL) to 40 mm CRL were processed for microscopic examination. Normal fetuses from 32 mm CRL to 250 mm CRL and fetuses with malformations of the central nervous system (CNS) were cut sagittally through the midline and their pharyngeal regions were examined macroscopically. Our observations suggested that, at an early embryonic stage, the notochord and basicranium might play important roles in the formation of the human pharynx. At a later stage, the growth of the maxillomandibular portion also appears to be important in the formation of the pharynx. The finding of malformation of the pharynx in fetuses with maldevelopment of the CNS suggests that the brain may play an important role in the formation of the pharynx.

The segmental Bauplan of the rostral zone of the head in vertebrates.

Observations in a wide selection of lower vertebrate embryos have confirmed classical descriptions concerning segmentation of the early head mesoderm. The premandibular (PM) segment is seen as the most rostral representative of a continuous rostro-caudal series of condensations in the paraxial mesoderm, luminisations within which are secondary and variable in occurrence and form. The premandibular condensations are typically in continuity across the midline; the confluence, which comes to lie behind Rathke's pouch, marks the site of first mesoderm formation behind the oral membrane. The underlying consistency of pre-otic segmental pattern throughout the vertebrates is frequently obscured by superimposed variation in morphological detail between species, reflecting the dynamic nature of the morphogenetic tissue processes. Luminisation is one such morphogenetic epiphenomenon. Variations in it account for the terminal (Platt's) vesicle and "proboscis pores": such structures cannot therefore be safely used to infer evolutionary homologies. Many previous difficulties facing segmentation theory are explained as the result of failure to take account of the dynamic nature of the responsible morphogenetic events.

Formation of the tonsillar corpuscle.

In this study of the human palatine tonsil we examined epithelial structures found always in the vicinity of the crypts and closely resembling thymic Hassall's corpuscles. We propose that in the reactive tonsillar lymphoid tissue these corpuscles form as a result of occlusion of fine microcrypts by the expanding lymphoid follicles during antigenic stimulation. The reticulated epithelial cells lining these microcrypts may then loose their polarisation, and gradually degenerate deep in the parenchyma, forming concentrically arranged parakeratotic pearls, rather than desquamate at the free epithelial surface. The structural similarities of the tonsillar and Hassall's corpuscles may be explained by endodermal embryological origin of the primordia of both organs, and by the specific degenerative properties of epithelia in the lymphoepithelial immune organs.

Repeated antigenic challenge induces earthworm coelomocyte proliferation.

Annelids are able to protect themselves against foreign materials by natural and acquired cellular immunity. The aim of this study was to characterize the kinetic of antigen induced proliferation of earthworm coelomocytes. The proliferative activity of free coelomocytes of Eisenia foetida decreased after a second contact with the same antigen. Precursor cells in the mesenchymal lining of the coelomic cavity responded to stimulation immediately. These results indicate that for a successful triggering of the proliferative response of the free coelomocytes repeated contact with stimulating agents is needed.

Analytical morphometry of sagittal fronto-facial profiles of 2nd-6th month human foetus.

A prominent problem in the morphological study of developing biological structures is shape parametrization with the aim to evaluate transformations in a non subjective way. We carried out an analytical morphometrical study on a series of human embryos, by means of the S.A.M. (Shape Analytical Morphometry) software package. After standardization and normalization of the fronto-facial sagittal profiles, the analytical procedures applied were: 1) Fourier analysis: each profile was considered as an irregular but periodic function obtained by the sum of sinusoids of increasing order. 2) Shape Asymmetry Evaluation: couples of profiles are compared by means of "Janus" procedure; by a parabolic fitting we obtained parameters able to evaluate allometric and isometric differences between the two profiles. The preliminary results of the applied procedures indicated that rate and direction of allometric and isometric growth are not constant during the time.

[An unusual early complication of tonsillectomy]. / Neobvyklá casná komplikace tonzilektomie.

The authors describe the observation of a localized tissue emphysema of the right cheek, which developed in an eight-year-old child as the early complication of tonsillectomy performed under local anaesthesia. In addition to reflections on the possible pathways of the gas from the tonsillar bed into interstitial spaces of the cheek, the authors draw attention also to possible concurrent penetration into the soft tissues of the neck and mediastinum.

[Radiodiagnostic methods in the postmortem study of a dicephalus masculinus]. / Radiodiagnostische Methoden in der postmortalen Untersuchung eines Dicephalus masculinus.

With conventional radiography and with CT several malformations were detected in a dicephalus masculinus. The most important were: 2 spinal medullas in a common spinal canal (TH1 to L4), hydrocephalus of both lateral ventricles and of the third ventricle, prolaps of the left hepatic lobe into the left thoracic cavity, two aortic arcs, one large internal jugular vein, and twin bases of the vertebrae TH1 to L5. The dicephalus had not only a double head, but also two cervices connected by a falx.

Palatine tonsils--their evolution and ontogeny.

The structure of the palatine tonsils in an evolutionary line of mammals and its development in man was studied. The homologies between the thymus and tonsils were pointed out. Both primordia come from the same source and their epithelium reticulizes and can form concentric corpuscles. The tonsil develops from a doubled primordium and consists of two lobes. Attention is drawn to the close relation between tonsils and glands. In the evolution the glands diminish and more crypts are formed. After antigenous stimulation, proliferation of the crypt epithelium takes place which provokes the increase of venules. They bring new populations of lymphoid elements which penetrate into the reticulated epithelium and finally form new follicles.