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Biomedical subjects

T Karchev

Publications and source records attributed to T Karchev.

11 recordsLinked to original sources
PubMed1996

Significance of M-cells in the panautoprotection of the body.

Life consists of continuous acceptance, adequate processing and appropriate use of energy-carriers present in and around the body, along with effective elimination of those of them which invade the organism from outside, or appear inside, thus threatening its existence. It is clear that all cells making up the organism are naturally involved in its protection. Since no "extracorporal bodyguards" have been detected so far, recently I introduced the concept of panautoprotection in the human organism, which was subsequently expanded to comprise perhaps the broadest and most sufficiently exhausting paradigm on the essence of life and other known events in the Universe. The M-cells emerging during the evolution of birds and mammals are highly specialized immunocompetent cells, functioning non-stop throughout the individual's entire life as antigen receptors. Penetrating mainly through the nose and mouth, alien antigens, which I perceive mainly as mediators of biointegration, trigger the mechanisms of acquired or adaptive immunity through the M-cells. Through them, the environment models the body of each individual so as to transform it into its integral part. Jointly with Prof. Mogi, we studied the M-cells in the nasal tonsil of SCID-mice and found them to appear definitely differentiated, suggesting that the relevant information is genetically coded. The typical pores of the basal lamina are probably M-cell induced.

Animals↗
PubMed1994

Surfactant-producing epithelium in the dorsal part of the cartilaginous eustachian tube of mice. Light, transmission, and scanning electron microscopic observations.

The nonciliated area in cartilaginous roof tubothelium of 14 conventional mice was examined histologically and classified as a modified transitional respiratory epithelium. On the free cell surface numerous short microvilli were found. On the lower roof surface in the midcartilaginous portion and especially near the pharyngeal orifice, a convoluted pattern of ridges and pits was observed. These structural peculiarities are interpreted as adaptive features, ensuring survival of the cells in a dynamic tubal environment. On the basis of systematic observations of the multilamellar bodies in the cytoplasm resembling the phospholipid lamellar bodies of pulmonary surfactant, which are discharged in the tubal lumen and to be found in the pits, it is suggested that the nonciliated cells are "specialized" surfactant-producing tubocytes. The synthesis of surfactant-precursors starts in the basal layer. Different phases of the secretory process were observed in the neighboring cells. This finding is related to the cell-cooperation constantly releasing the secretory product, and natural cell-turnover. Unlike the previously reported surfactant-producing cells in the lower tubothelium of other species, roof tubothelial cells of mice are morphologically similar to type II pneumocytes.

Animals↗
PubMed1992

Lipoid proteinosis.

Lipoid proteinosis (Urbach-Wiethe disease) is a rare, recessively inherited disorder that is characterized by the deposition of hyaline-like material in the skin, oral cavity, and other tissues. It usually appears in infancy with hoarseness. We report a case of lipoid proteinosis in a 10-year-old boy that demonstrates the characteristic clinical, histologic, and ultramicroscopic features of this disease.

Child↗
PubMed1989

Amyloid-like protein in children with rhinoscleroma.

Mucosal specimens from two children with rhinoscleroma have been investigated by light-, fluorescent- and electron microscopy. Amyloid-like protein was found, located not only in the vessel walls but also impregnated in the basic substance of the connective tissue. In this paper the genesis of this protein is discussed, assuming that it could be a result of auto-immune reactions.

Adolescent↗
PubMed1988

Specialization of tonsils as analyzers of the human immune system.

On the basis of current knowledge on the structure and function of tonsils, in agreement with the author's concept on "panautoprotection" in the human body, an attempt at characterizing tonsils as analyzers of the immune system is made. It is suggested that adequate signals for these analyzers are high-molecular substances penetrating orally and nasally. It is emphasized that tonsillar specialization as immunological analyzers refers mainly to the structure of their surface epithelium, the latter being considered as a peripheral component of these analyzers. In evolution, antigen sensitive cells have developed, i.e., the so-called M (membranous) cells. The phenomenon of reticulation in adenoid and tonsillar epithelium is associated with the presence of M-cells in its surface. It is submitted that M-cells may produce immunologically relevant proteins, designated as tonsillopeptides, which can play a role in the formation of lymphoid cells with specific immunological competence. It is presumed also that all possible immunological interactions mediated by the whole range of cellular and humoral factors of immunity in cooperation with the autonomous nervous system may take place in tonsils.

Humans↗
PubMed1985

Phagocytic activity and bactericidal capacity of polymorphonuclear leukocytes in children with recurrent otitis media.

In 19 children with recurrent otitis media the phagocytic activity of blood granulocytes was studied and indirectly also their bactericidal capacity by means of the NBT test and myeloperoxidase activity. The mean value of granulocytes containing latex particles was 44.32% in the patients group, which differed significantly from the mean value established in controls: 66.54%. The mean phagocytic number in the patients group, 1.82 was also significantly diminished in comparison to controls: 2.41. The average number of nitroblue tetrazolium (NBT)-positive cells in patients, 86.74% as well the mean myeloperoxidase index, 2.52 did not differ from the mean control values, 92% and 2.42, respectively. In two patients a lower percentage of NBT-positive cells was determined. They are probably heterozygous carriers of an enzyme deficiency related to a depressed bactericidal activity of phagocytes. Patients with recurrent otitis media should be tested on possible phagocytic dysfunctions which may be helpful in understanding the pathogenesis of infections and also in identifying infants at particular risk of otitis media.

Child↗
PubMed1984

M-cells in the epithelium of the nasopharyngeal tonsil.

Electron-microscope investigation on the epithelium was carried out in 23 nasopharyngeal tonsils. Adenoidectomy was performed on the ground of recurrent adenoiditis in the interattacks period in 13 boys and 10 girls between the ages of 2 to 4. The presence of five characteristic cellular types was found on the surface of the adenoid epithelium: tall cylindrical ciliated cells; cylindrical cells covered only with microvilli; secretory cells with the predominance of the so-called "dark granules"-producing cells; flat epithelial cells; cubic cells with microvilli on the surface and many vesicles in the cytoplasm. The last type of cells rank together with the M-cells, described by Owen and Jones in the epithelium of Peyer's patches in human beings and found in the palatal tonsil by various authors. A discussion is made on the pinocytary and secretory activity of the M-cells that is being linked with the immunogenesis of the nasopharyngeal tonsil. It is pointed out that in normal conditions the reticulation of the epithelium of the adenoid is found only in the zones that had their surface covered by M-cells.

Adenoids↗
PubMed1982

Electron-microscope observations on the tonsillar epithelium in children with recurrent tonsillitis.

Twenty tonsils from children aged 3-6 years removed by operation due to recurrent tonsillitis have been examined. Electron-microscope observations of the epithelial layer have shown a lowering of the number and a reduction of the tubulo-vesicular system of the M-cells. The squamous stratified epithelium is predominating; it is keratinized in some places. Lymphocytes in an active phase and vascular activity in the parenchyma of the removed tonsils are very rare to observe; these were seen only in relation with the M-cells. The above-mentioned data may serve to prove Surjan Jr.'s 1980 hypothesis on the key-importance of metaplastic change of the tonsillar epithelium in recurrent tonsillitis pathogenesis.

Child↗
PubMedDate not supplied

[Ultrastructural studies of Klebsiella rhinoscleromatis].

In 1870, F. Hebra described a slowly progressing granulomatous disease of the nasal mucous membrane he called rhinoscleroma. Later, N. M. Volkovich and A. Frisch isolated from patients suffering from this disease a microorganism they termed Klebsiella rhinoscleromatis. In 1932, S. Belinov proposed to name the disease Scleroma respiratorium because the pathological process developing in rhinosclerosis may involve not only upper but also lower airways. In 1961, T. Steffen and J. Smith demonstrated that Klebsiella rhinoscleromatis conformed to Koch's postulates and was an etiological factor of inflammatory changes typical of scleroma. This paper presents results of ultrastructural examinations of Klebsiella rhinoscleromatis isolated from two patients with Scleroma respiratorium. It was shown that as the degenerative process developed, the amount of electron-dense material around the bacterial cell wall decreased progressively and only fragments of the cellular membrane remained.

Adolescent↗