MF AI Elektroninės mikroskopijos laboratorija (04.03.03)

To assess the effectiveness of the benzyl benzoate and benzyl alcohol (BABB) solution in transparent teeth preparation compared to methyl salicylate using comprehensive digital and radiographic quantitative values analysis.

Background. Heart areas enriched in endings of sensory nerve fibres (NEs) play a role as reflexogenic zones (RZs), where primary afferent signals initiate neural mechanisms controlling heart activity. Distribution, appearance, and chemical phenotypes of cardiac NEs remain under consideration. Study aims to characterise the morphological diversity of NEs in mammalian and human hearts, exposing links between their structural patterns and chemical phenotypes.

Background. Educational simulation using synthetic organ phantoms becomes very popular in training of wide range medical professionals. However, in some cases only specially processed natural hard tissue preparations could help to gain particular valuable skills for future practices. One of major features of such preparations is translucency enabling comprehensive control of the educational process, e.g., instrument manipulations. Aim. The aim of this study was to elaborate a method for evaluation of optical properties of the preparations enabling assessment of its suitability and optimisation of the preparation process. Methods. This particular study was designed to compare optical properties of natural teeth preparations made using two chemical methods – a) the traditional, using methyl ester of salicylic acid, giving satisfactory results, but toxic, vs b) using benzyl benzoate and benzyl alcohol, from the first impression giving also satisfactory results, but being much less toxic. Translucent light images of 32 teeth were captured using a collimated white light source and a digital camera (C-P8, Optika, Italy), with the teeth positioned on a dental glass slab. A small piece of prosthodontic impression material (A-silicone Elite Transparent, Zhermack, Italy) was placed nearby to normalise exposure and white balance across all images. The optical properties of tooth translucency were analysed using custom-made image processing algorithms in the MatLab environment. The algorithm segmented the apical part of each tooth using superpixel technique. Optical properties of segmented apical part of each tooth were estimated in HSV colour scheme. Results. We did not find any statistical difference in optical properties of apical parts prepared by both methods. Statistical analysis (Mann–Whitney U test, p > 0.2) showed no significant difference in hue, saturation, nor in value between the two groups. Conclusions. The optical properties of the translucent teeth prepared by both methods were similar, so we advise to use less toxic method using benzyl benzoate and benzyl alcohol. The principle of evaluation of optical properties could be used also for assessment of other tissues and other processing methods.

Aim. This article was focusing its scope an analysis of the attitude of university students on their perceived understanding of health status, attitudes on health behavior and possibilities of involvement in health promotion, life-style change activities. The aim of the research was to analyze the perceptions of university students regarding health lifestyle changes and health promotion. The study also had objective to identify key factors influencing youth health and to develop recommendations for improving their physical and mental well-being. Methods. The object of this questionnaire survey involved the full-time university students divided into two groups (in total 60 respondents): 30 first-year and 30 second-year students studying psychology. The research was conducted at Dnipro Humanities University, in a classroom setting during daytime hours after lectures in April 2024. Results. Data analysis has shown that perceptions of health concepts are closely linked to personal values, knowledge, and skills in the health domain. Engagement in wellness activities and a positive attitude towards a healthy lifestyle are indicators of students’ readiness for successful performance in various aspects of their lives. Conclusions. The results of the analysis highlight the necessity of a comprehensive approach to health promotion and disease prevention among the younger generation. It is crucial to consider the diversity of opinions and support positive health habits while enhancing understanding and health literacy regarding harmful behaviors, such as addictive behaviors (alcohol consumption, smoking, drug use), and promoting physical activity among university students.

In the primary visual cortex area V1 activation of inhibitory interneurons, which provide negative feedback for excitatory pyramidal neurons, can improve visual response reliability and orientation selectivity. Moreover, optogenetic activation of one class of interneurons, parvalbumin (PV) positive cells, reduces the receptive field (RF) width. These data suggest that in V1 the negative feedback improves visual information processing. However, according to information theory, noise can limit information content in a signal, and to the best of our knowledge, in V1 signal-to-noise ratio (SNR) has never been estimated following either pyramidal or inhibitory neuron activation. Therefore, we optogenetically activated pyramidal or PV neurons in the deep layers of cortical area V1 and measured the SNR and RF area in nearby pyramidal neurons. Activation of pyramidal or PV neurons increased the SNR by 267% and 318%, respectively, and reduced the RF area to 60.1% and 77.5%, respectively, of that of the control. A simple integrate-and-fire neuron model demonstrated that an improved SNR and a reduced RF area can increase the amount of information encoded by neurons. We conclude that in V1 activation of pyramidal neurons improves visual information processing since the location of the visual stimulus can be pinpointed more accurately (via a reduced RF area), and more information is encoded by neurons (due to increased SNR).

Objectives Endodontic teaching models do not reflect natural tooth root canal shaping perceptions. As a result, alternative methods for dental education were developed, specifically the use of natural extracted teeth. However, the traditional approach of using methyl salicylate to prepare translucent teeth raises safety concerns due to its high toxicity. The objective of this study was to assess the effectiveness of benzyl alcohol and benzyl benzoate (BABB) solution in clearing extracted teeth. Methods Freshly extracted 32 single-rooted teeth were immersed in 10% formalin for 24 hours. They were then processed following a standard protocol, which included alternating immersion in 5.25% sodium hypochlorite, demineralization in 5% nitric acid, dehydration in a series of alcohol solutions, and finally placement in xylene. The teeth were then divided into two groups: the first (control) group, consisting of 20 teeth, underwent the traditional protocol, which involved soaking the teeth in 99% methyl salicylate for 24 hours; the second group, consisting of 12 teeth, was immersed into the BABB solution for 24 hours. Optical properties of the processed teeth translucency were evaluated by transluminant light imaging using collimated light source and digital camera C-P8 (Optika, Italy). Image processing algorithms in the MatLab computational environment were used to evaluate the colour and intensity of the translucent light at the apical area of the root in each tooth. Results The optical properties of selected anatomical locations were the same across both groups of teeth evaluating Hue, Saturation and Value of pixels (independent samples Mann-Whitney U test, p > 0.2). Conclusions Benzyl alcohol and benzyl benzoate solution is equally effective compared to traditional methyl salicylate for preparing translucent teeth in dental education.

Background and Aim. The evolutionary approach in medicine offers insights into health and disease by understanding the biological context of pathogenesis. Despite the long-term examinations of cardiac neuroanatomy, neuronal structures like sub-mesothelial receptors remain poorly understood and are not analysed through different species. We aimed to investigate these receptors in rats, mice, and bats comparing their distribution and morphology between mammalian species different in their life biology. Material and Methods. This study involved the use of mature BALB/c mice’ (n=3), Wistar rats’ (n=3) and Myotis brandtii bats’ (n=3) hearts, including both male and female specimens. The bat hearts were obtained from an organ archive of the Institute. Atria were carefully separated from the ventricles to make flat whole-mount preparations. Immunohistochemical staining with general neuronal marker PGP9.5 followed to observe sub-mesothelial receptors. Imaging of neuronal structures was performed using a confocal laser microscope at magnifications of 20-63x, while their calculations - using open-source FIJI 2.15.1 software. Results. Sub-mesothelial receptors are located on the ventricular wall, in the first three-fifths from the coronary groove towards the apex. The possible baroreceptors are found on the very surface of the epicardium beneath the mesothelial cells. These sub-mesothelial sensory endings extend from the larger epicardial nerves and form a “flower-spray” structure on the surface of the ventricle. However, the morphology of the “flower-spray” endings varies according to the species: in BALB/c mice average “flower-spray” size – 756.6 μm2 with wide and sparse receptor endings, in Wistar rats – 4687.2 μm2 with narrow and sparse receptor endings, in M. brandtii bats - 2947.8 μm2 with wide and dense receptor endings. Conclusions. This study reveals new insights into sub-mesothelial receptors across two evolutionary close and one distant species. The consistent distribution patterns were found with different species-specific variations. Further studies are necessary to clarify the identified species-dependent differences.

Background and Aim. Calcitonin gene-related peptide (CGRP) is localized in sensory fibers and innervates smooth heart muscles and vasculature. CGRP also participates in regulating cardiovascular events: 1) Locally in case of inflammation; 2) Systemically, (in animal studies), demonstrates that hypertension can be reduced due to its vasodilator activity. However, long-term hypertension damaging or compensatory aftereffects on the cardiac nervous system sensory part are not fully researched. Material and Methods. Atrial and ventricular epicardiac nerves of Spontaneously Hypertensive Rats (SHR, n=3) and normotensive Wistar Kyoto rats (WKY, n=3) were examined. We used either transverse cryosections. Animals were male and elderly (>18 months). Neural structures were stained immunohistochemically for protein gene product 9.5 (PGP9.5 – general neuronal marker) and CGRP. Nerve fractions stained by PGP9.5 and CGRP were measured using the threshold function and expressed as percentages from the total nerve area. Results were described as mean ± standard error and compared by Student t-test, p-value<0.05. Results. The seldom intrinsic nerves occur within the epicardium and on the surface of myocardium. The rest of the myocardium and endocardium contained only a meshwork of nerve fibers. Nerve cross-sections were arranged similarly on ventricles, but appeared smaller on the right one, especially SHR (leftWKY 908±87 vs. leftSHR 925±112 µm2, p=0.909; rightWKY 747±106 vs. rightSHR 581±59 µm2, p=0.147). The scarce area fraction stained with PGP9.5 occupies only half of cross-section, more plentiful in WKY on the right (WKY 59±2.5% vs. SHR 51±2.2%, p=0.012), and in SHR – on the left (WKY 51±1.7% vs. SHR 59±1.6%, p=0.001). On the other hand, the CGRP area fraction significantly (almost twice) increased in the hypertensive group, probably due to compensatory vasodilative activity (WKY 1.31±0.09 vs. SHR 2.51±0.13, p<0.001). Conclusions. The epicardiac nerve total neuronal material with the accent to the sensory component is altered by long-term hypertension.

Įvadas Dantų šaknų kanalų anatomijos mokymasis ir ikiklinikinių įgūdžių įgijimas yra didelis iššūkis odontologijos studentams. Aiškus šaknies kanalo anatomijos supratimas yra būtina sąlyga atliekant įprastines endodontines procedūras. Mokymuisi buvo sukurti plastikiniai permatomi dantų modeliai, kurie neperteikia natūralių dantų kietųjų audinių savybių bei instrumento slinkimo kanale pojūčio. Be to, plastikiniai dantų modeliai yra brangūs bei gamtai nedraugiški gaminiai. Šių trūkumų nėra dirbant su natūraliais išrautais dantimis, kurie, naudojant tam tikras chemines medžiagas gali būti skaidrinami. Tradiciškai skaidrinimui naudojamas esteris metilsalicilatas, tačiau darbas su juo gali būti kenksmingas žmogaus organizmui. Mažiau toksiškas benzil-alkoholio ir benzil-benzoato tirpalas (BABB) yra alternatyvi audinių skaidrinimo medžiaga, kuri potencialiai gali būti panaudojama ir kietųjų danties audinių skaidrinimui. Tikslas Įvertinti BABB tirpalo veiksmingumą skaidrinant išrautus dantis ir palyginti su metilsalicilato poveikiu. Metodika 32 šviežiai išrauti vienašakniai dantys buvo pamerkti į 10 % formaliną 24 valandom. Dantys buvo paruošti skaidrinimui pagal standartinį protokolą (3): laikymas 5,25 % NaOCl, demineralizacija azoto rūgštyje, dehidratacija alkoholio tirpaluose ir patalpinimas į ksileną. Prieš skaidrinimą dantys buvo padalinti į dvi grupes: pirmoje grupėje (N=20), buvo taikomas tradicinis protokolas: dantys pamerkti į 99 % metilsalicilato tirpalą; antroje grupėje (N=12) dantys buvo panardinti į BABB tirpalą. Po skaidrinimo padarytos abiejų tiriamųjų grupių dantų rentgenogramos bei nuotraukos (skaitmeninė kamera C-P8, "Optika", Italija), peršviečiant dantis lygiagrečių spindulių matoma šviesa. Abiem būdais gautuose vaizduose išskirtų pikselių vertės atitinkančios apatinį šaknies trečdalį buvo vertinamos MatLab skaičiavimo terpėje. Rezultatai Išskaidrintų dantų optinės savybės matomoje šviesoje skyrėsi nuo kontrolinių neskaidrintų dantų ir buvo vienodos abiejose tirtose dantų grupėse, vertinant pikselių atspalvį, spalvų sodrumą ir bendrą intensyvumą (nepriklausomų imčių Mann-Whitney U testas, p > 0,2). Rentgeno spindulių sugertis išskaidrintuose dantyse buvo reikšmingai mažesnė nei neskaidrintų ir skyrėsi tarp grupių - BABB medžiaga paveikti dantys buvo pralaidesni rentgeno spinduliams negu paveikti metilsalicilatu (ANOVA ir Bonferoni post hoc testas, p < 0,01). Išvados BABB tirpalas yra tiek pat veiksminga dantų skaidrinimo medžiaga kaip ir metilsalicilatas, vertinant paruoštų dantų optines savybes, o lyginant rentgeno spindulių sugertį, net ją pranoksta. Didesnė BABB grupėje skaidrintų dantų demineralizacija atitinka geresnį šviesos pralaidumą, kas lemia tokiu būdu paruoštų dantų tinkamumą odontologinės edukacijos tikslams.

Įvadas Vienas pagrindinių endo-perio patologijos etiologinių faktorių yra pirminės periodonto infekcijos patogeninių mikroorganizmų patekimas į pulpą per šaknies viršūninę angą, pridėtinius kanalus, mikroįtrūkimus, dentino tubules bei jatrogeninės kilmės danties vientisumo pažeidimus (1). Siekiant gerų periodonto patologijos gydymo rezultatų, yra svarbu įvertinti pulpos būklę ir endodontinio gydymo reikalingumą remiantis klinikiniais simptomais bei pulpos jautrumo testais (2). Daugiašakniuose dantyse testai gali rodyti klaidingai teigiamą atsaką dėl nevienodo pulpos pažeidimo laipsnio skirtinguose kanaluose. Tai lemia infekcijos patekimo kelio į pulpą anatominė lokalizacija - neretai uždegimas prasideda viename iš kanalų ir tik vėliau išplinta visoje danties pulpoje, kas apsunkina klinikinių simptomų interpretavimą ir patologijos diagnostiką (3). Histologinių patologijos vaizdų analizė suteikia vertingų įžvalgų apie patogenezės mechanizmus beipadeda pasirinkti tinkamiausią gydymo metodiką. Tikslas Atlikti palyginamąjį klinikinį, radiologinį bei histologinį daugiašaknio danties su endo-perio patologija ištyrimą. Metodika 63 m., nusiskundimų neturinti moteris atvyko į LSMU Veido ir Žandikaulių chirurgijos kliniką 16 danties šalinimui prieš protezavimą. Atliktas klinikinis bei radiologinis danties ištyrimas. Išrautas dantis paruoštas fiksacijai parafino bloke pagal tradicinį histologinį protokolą (4). Supjausčius parafino bloką mikrotomu, preparatai nudažyti hematoksilinu-eozinu ir analizuojami šviesiniu mikroskopu. Rezultatai: Klinikinio danties ištyrimo metu kariozinių pažeidimų 16 danties paviršiuose nustatyta nebuvo, matomas pleištinis defektas skruosto pusėje. Stebima išreikšta lokali dantenų recesija, dantenos uždegiminės, zonduojamos gilios periodonto kišenės, tarpšaknio defektas F2, dantis nepaslankus. Perkusija ir palpacija neigiamos. Atsakas į šalčio testą teigiamas, į EOD - neigiamas. Ortopantomogramoje - horizontali kaulo rezorbcija, dalinė pulpos kameros ir kanalų kalcifikacija, patologinių pakitimų viršūniniame periodonte – nėra. 16 danties dentalinėje viršūninio apydančio rentgenogramoje matoma vertikali kraštinio kaulo rezorbcija. Daugiausia kaulo netekta ties distaline šaknimi (rezorbcija apima daugiau nei 2/3 šaknies ilgio). Atlikus histologinių danties vaizdų analizę, distalinėje šaknyje nustatyta dalinė pulpos nekrozė su uždegiminių ląstelių infiltracija, o gomurinėje šaknyje nustatyta gyva, uždegimo nepažeista pulpa. Išvados Danties su endo-perio patologija histologinis vaizdas iliustruoja pulpos uždegimo plitimą daugiašakniuose dantyse ir parodo klinikinių ir radiologinių tyrimų ryšį su histologiniu vaizdu. Remiantis klinikiniu ir radiologiniu ištyrimu galima klaidinga diagnozė ir netinkamas gydymo plano parinkimas, todėl gydytojas turi žinoti endo-perio patologijos patogenezės mechanizmus bei mokėti atlikti tikslų kompleksinį danties ištyrimą.