Comparative analysis of antigen-presenting cells in gingival tissues in healthy and periodontitis patients.

AIMS: Microbial flora of dental plaque trigger innate and adaptive immune responses. The function of antigen-presenting cells (APCs) is to bridge the innate and adaptive immune systems. The human immune system contains three main types of APCs: dendritic cells (DC) (Langerhans cells (LCs) and interstitial DCs, IDCs), macrophages and B lymphocytes. In this study, the distribution and density of all APCs in healthy and inflamed human gingival tissue were comparatively analysed. METHODS: Research was conducted on gingival biopsy specimens obtained from 55 patients and classified in three groups: healthy gingiva (control group, n=10), moderate periodontal disease (PD) (n=21) and severe PD (n=24). For APCs' identification antibodies raised against CD1a (for LCs), S100 protein (for iDCs), CD68 (for macrophages) and CD20 (for B lymphocytes) were used. RESULTS: Increased density of IDCs, macrophages and B lymphocytes in lamina propria and reduced density of LCs in the gingival epithelium were found in patients with periodontitis. Simultaneously, it was noticed an increased concentration of macrophages and B cells in the gingival epithelium in patients with PD. No statistically significant difference in the distribution and density of APC was found among patients with moderate and advanced periodontitis. CONCLUSIONS: It was hypothesised that in the periodontitis the role of antigen presentation was largely taken from LCs by the DCs, macrophages and B cells. These APCs are thought to have less protective and tolerogenic potential than LCs and this is a significant reason for alveolar bone destruction in periodontitis.

Quantification of mast cells in different stages of periodontal disease.

BACKGROUND/AIM: Mast cells are mononuclear cells originating from bone marrow. They produce various biologically active substances, which allow them to actively participate in immune and inflammatory processes associated with periodontal disease. The study focused on distribution and density of mast cells in healthy gingiva as well as in different stages of periodontal disease. METHODS: The material used for this purpose was gingival biopsies taken from 96 patients classified into 4 groups: healthy gingiva, gingivitis, initial and severe periodontal disease. Toluidine blue staining according to Spicer was utilized for identifying mast cells. RESULTS: Basing on our study, the density of mast cells in the gingival tissue increases with the progression of the infection, which means they are more numerous in gingivitis compared to healthy gingiva, as well as in periodontal disease compared to gingivitis. CONCLUSION: Increase in the number of mast cells in the infected gingiva can be correlated with an increased influx of inflammatory cells from blood circulation into the gingival stroma, as well as with the collagen lysis, since these cells produce substances with collagenolytic potential. Based on the distribution of mast cells, it could be concluded that in the evolution of periodontal disease there are significant dynamic alterations in migration and localization of these cells.

Morphometric analysis of collagen and inflammatory cells in periodontal disease.

BACKGROUND/AIM: Periodontal disease affects gingival tissue and supporting apparatus of the teeth leading to its decay. The aim of this study was to highlight and precisely determine his- tological changes in the gum tissue. METHODS: Gingival biopsy samples from 53 healthy and parodontopathy-affected patients were used. Clinical staging of the disease was performed. Tissue specimens were fixed and routinely processed. Sections, 5 µm thin, were stained with hematoxylin and eosin, histochemical Van-Gieson for the collagen content, Spicer method for mast-cells and immunochemical method with anti-CD68 and anti-CD38 for the labelling of the macrophages and plasma-cells. Morphometric analysis was performed by a M42 test system. RESULTS: While the disease advanced, collagen and fibroblast volume density decreased almost twice in the severe cases compared to the control ones, but a significant variation was observed within the investigated groups. The mast-cell number increased nearly two times, while the macrophage content was up to three times higher in severe parodontopathy than in healthy gingival tissue. However, the relative proportion of these cells stayed around 6% in all cases. Plasma-cells had the most prominent increase in the number (over 8 times) compared to the control, but again, a variation within investigated groups was very high. CONCLUSION: Gingival tissue destruction caused by inflammatory process leads to significant changes in collagen density and population of resident connective tissue cells. Although inflammatory cells dominated with the disease advancing, a high variation within the same investigated groups suggests fluctuation of the pathological process.

Otic artery: a review of normal and pathological features.

Three primitive arteries - the trigeminal, otic and hypoglossal take the names according to their close relation with the V, VIII and XII cranial nerves, while at the cervical level, the first segmental artery is named the primitive proatlantal intersegmental artery. When the human embryo is 4 mm long, these arteries serve as transitory anastomoses between primitive internal carotid arteries and bilateral longitudinal neural arterial plexus, which is the precursor of future basilar artery. Normal and/or abnormal morphofunctional aspects of the prenatal and postnatal forms of the otic artery are described according to the personal and literature data. Many (ab) normal arteries are also noted in differential diagnosis of the otic artery. Postnatally, individual incidence rates of the carotid-vertebrobasilar anastomoses have been found to be inversely related to their order of disappearance. The persistent trigeminal artery has a reported incidence from 0.06-0.6%, whereas the persistent primitive otic artery has been convincingly documented only in minor rates. Persistent carotid-vertebrobasilar anastomoses between the anterior and posterior cranial circulation are important to recognize during angiography for endovascular and surgical planning. Most frequently, the otic artery was an incidental finding.

Normal subtypes of the posterior part of the cerebral arterial circle in human fetuses.

BACKGROUND: Although centuries of the human CAC research are behind us, still there is a stimulus for the authors to describe something new or to add to the "archive" of already known facts about its angioarchitecture. METHODS: With normal configurations of the posterior part of the CAC in early prenatal status, 172 brains of human fetuses from the 13th to the 24th week were used in the purpose of investigation. Brain arteries were injected and microdissected using a surgical microscope. RESULTS: According to diameter values of vascular components in the posterior part of the CAC, 6 basic types and the corresponding number of their subtypes are formed. Incidences of bilateral transitory (18.6%), fetal (9.3%), and adult (33.1%) types, as well bilateral asymmetric types (fetal-transitory in 5.8%, adult-transitory in 14.5%, and adult-fetal in 18.6% of cases), proved that dominant configuration of posterior part had not been present in the period from the fourth to the sixth gestational month. CONCLUSION: The finding of normal subtypes of the posterior part of the CAC, as well as the absence of some subtypes, is a challenge for future studies of the posterior arterial pattern within vascular abnormalities or diseases.

Origin and evolution of viruses: escaped DNA/RNA sequences as evolutionary accelerators and natural biological weapons.

Knowledge of the origin and evolution of viruses could provide a better understanding of a number of phenomena in the field of evolution such as the origin and development of multi-cellular organisms, the rapid diversification of species over the last 600-700 million years and the lack of transitional forms in the evolution of species ("missing links") etc. One of the possible effects of escaped DNA/RNA sequences or viruses on the evolution of multi-cellular organisms, especially vertebrates, could be the phenomenon of horizontal transmission and dissemination of genes. Interestingly, if so, this effect could be considered as a model of primeval and natural genetic engineering. Other possible links between the evolution of multi-cellular organisms and viruses are connected with the fact that viruses represent the source of different forms of selective pressure such as epidemics of infectious diseases, autoimmunity, malignant alteration, reproductive efficiency, etc. At the same time, these two models of "long-term evolutionary relations" could represent "key factors" in the evolution between viruses and multi-cellular organisms. The capability of a genome to produce and emit DNA/RNA sequences or de novo created viruses which can be a vector of genes horizontal transmission and/or cause selective pressure on concurrent or predator species gives a new characteristic to viruses--the possibility of their acting as natural biological weapons. Finally, possibly evolutionary advantages of this genome capability could be one of explanations for the phenomena such as genome instability and its ability to emit DNA/RNA sequences and/or de novo created viruses, as well as evolutionary conservation of this unique phenomena.