Aleksandar Petrović

Evaluation of biological debris on endodontic instruments after cleaning and sterilization procedures

AIM To examine the presence of biological debris and the level of contamination on reusable endodontic instruments those were subjected to different cleaning methods prior to sterilization. METHODOLOGY One hundred and eighty endodontic instruments from eighteen dental practices were analysed. These practices used different decontamination protocols for reusable instruments. The presence of organic debris was detected by the use of Van Giesons stain. Forty-eight new stainless steel hand instruments were used as controls. The samples were examined by light microscopy. RESULTS Residual biological debris was observed in 96% of the samples. The mean value of maximum biological contamination was 34% in the group in which the instruments were brushed manually and immersed in alcohol, 25% in the group in which commercially available disinfectants were used and 5% in the group in which the instruments were cleaned ultrasonically. There was a statistically significant difference in the mean values with respect to the cleaning protocol applied (P < 0.001). CONCLUSIONS The methods used to clean endodontic instruments appear to be generally ineffective for the removal of biological debris. The best method was the one that included mechanical, chemical and ultrasonic cleaning of instruments.

Eyeworm infections in dogs and in a human patient in Serbia: A One Health approach is needed.

Thelazia callipaeda eyeworm has been frequently reported parasitizing humans in Asia. In Europe, the parasite is endemic in wild and domestic carnivores and only eight cases have been reported in humans so far. We describe the first case of human thelaziosis in Serbia, along with two cases in dogs from the same area. A One Health approach, based on cooperation amongst veterinarians and physicians, is strongly advised for this emerging infection in order to assess the risk for and prevent of the zoonotic infection.

Morphological and morphometric study of protective effect of green tea in gentamicin-induced nephrotoxicity in rats.

AIMS One of the most popular beverages worldwide, green tea, was investigated for its potential protective effect in a rat model of gentamicin-induced nephrotoxicity by monitoring functional and morphological changes in kidneys. MAIN METHODS The study was conducted on four groups of rats: control group (C), treated with only gentamicin (GM), treated with only green tea (GT) and treated with both gentamicin and green tea (GT+GM). Kidney function, oxidant and antioxidant parameters of renal tissue, as well as histopathological studies were assessed. Morphometric analysis was used to quantify these histopathological changes. KEY FINDINGS Gentamicin caused significant elevations in serum creatinine and urea and oxidative stress parameter (AOPP), while antioxidative enzyme catalase was significantly decreased. Histological sections of kidneys in GM group revealed necrosis of proximal tubules, vacuolation of cytoplasm and massive mononuclear inflammatory infiltrates in interstitium. Coadministration of green tea with gentamicin histologically showed renoprotective effect. Histological results were confirmed and quantified by morphometric analysis. Also in this group we measured ameliorated parameters of renal functions and antioxidative defense. SIGNIFICANCE Regenerative potential of green tea after renal injury induced by gentamicin could be explained through the decrease of oxidative stress and lipid peroxidation. Green tea is a natural antioxidant, with many health promoting effects, widely available and in accordance to that affordable. Because of the established habits, people largely consume it as a beverage. It could be beneficial in the reduction of oxidative stress and changes caused by it primarily in renal tubules and interstitium.

Anti-inflammatory effect of the Salvia sclarea L. ethanolic extract on lipopolysaccharide-induced periodontitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE Salvia sclarea L., clary, is an aromatic plant traditionally used in folk medicine for the treatment of various diseases and conditions. Although it has been primarily used as a stomachic, there are data on traditional use of S. sclarea as an agent against gingivitis, stomatitis and aphthae. AIM OF THE STUDY The aim of the study was to examine the effect of the S. sclarea ethanolic extract on the lipopolysaccharide (LPS)-induced periodontitis in rats from the immunological and histopathological standpoint. MATERIAL AND METHODS Periodontal inflammation in rats was induced by repeated injections of LPS from Escherichia coli into the interdental papilla between the first and second right maxillary molars. The extract was administered two times a day by oral gavage (200mg/kg body weight). The inflammatory status was assessed by the measurements of proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) of gingival tissues and descriptive analysis of histological sections of periodontium. Chemical characterization of the extract was determined using high performance liquid chromatography system (HPLC). Antioxidant activity of the extract was estimated with two in vitro complementary methods: 2,2-diphenyl-1-picrylhydrazyl and β-carotene/linoleic acid models. RESULTS Treatment with S. sclarea extract, compared to the untreated group of the rats, significantly diminished the process of inflammation decreasing the levels of IL-1β, IL-6 and TNF-α, reducing the gingival tissue lesions and preserving bone alveolar resorption. Considerably smaller number of inflammatory cells and larger number of fibroblasts was noticed. The administration of the extract three days earlier did not have significant preventive effects. Rosmarinic acid was the predominant compound in the extract. The extract showed strong antioxidant effects in both test systems. CONCLUSIONS S. sclarea extract manifested anti-inflammatory effect in LPS-induced periodontitis suggesting that it may have a role as a therapeutic agent in periodontal diseases. Having in mind that overproduction of reactive oxygen species is connected to periodontitis, the strong antioxidant capacity may be contributable to anti-inflammatory properties of the extract.

Ultrastructural analysis of the root canal walls after simultaneous irrigation of different sodium hypochlorite concentration and 0.2% chlorhexidine gluconate

To determine whether sodium hypochlorite (NaOCl) with 0.2% chlorhexidine gluconate (CHX) leads to colour change and precipitate formation, and to ultrastructurally analyse the dentine surface after simultaneous irrigation with 0.5% NaOCl and 0.2% CHX. Four tubes in which 5ml of different NaOCl concentrations and 5ml 0,2% CHX were placed, were observed every 15 minutes in the first two hours and after 7 days. Mixture solutions were centrifuged at 800 rpm/4 min. A precipitate is observed under light‐microscopy. Thirty‐five single‐rooted teeth were instrumented using crown‐down technique with irrigation: Positive control: distilled water, Negative control: 0,5% NaOCl+15% EDTA, Experimental group: identical to the negative control, then canals were treated with 0.5% NaOCl+0.2% CHX. The longitudinal root sections were observed under scanning‐electron‐microscopy. The amount of debris was assessed with 5/score‐system, and the results were analysed using the Mann‐Whitney U test (p < 0.001). Change in colour was noticed immediately after the merger and it did not change with time. Mixture solutions showed considerable turbidity, but precipitate was observed only after centrifugation. Statistical analysis showed a significant difference in the dentinal wall purity when comparing the cervical and middle root canal thirds between the experimental and negative control group. The difference was also observed between the cervical and middle thirds compared to the apical third of the root canal within these groups. Interaction between NaOCl and CHX, as well as the creation of precipitates, depends not only on the concentration of NaOCl, but also on the concentration of CHX. Microsc. Res. Tech. 75:1099–1103, 2012.

Subconjunctival Infection due to Dirofilaria Repens - Case Report

Summary The aim of the survey was to present the clinical course and surgical treatment of the first case of human ocular dirofilariosis on the territory of the city of Niš, in the southeast Serbia. Male patient, 57 years old, visited an ophthalmologist because of extreme swelling and redness of the eyelids of the right eye, scratches and pain in his right eye. On standard examination on biomicroscope, temporally 3 mm from the limbus, intrapalpebrally, a mobile parasite was observed in the subconjunctival space. Complete extraction of the living parasites, 13 cm long, was performed. A sample of the nematode based on morphological and morphometric characteristics was identified as Dirofilaria repens-like. The diagnosis was confirmed with molecular methods. For ocular dirofilariosis, surgical methods and complete extraction of the parasite are the only ways to achieve complete recovery.

Distribution of Collagen I, III, and IV and Laminin in the Human Liver during Prenatal Development

In the absence of systematized data on the extracellular matrix components during prenatal liver development, the present study aimed to investigate the time of appearance and distribution of collagen types I, III, and IV and laminin. The study material included embryonic and fetal livers, aged 7–37 weeks, categorized into 3 trimesters. The material was stained using hematoxylin-eosin and immunohistochemistry methods for the identification of collagen I, III, and IV and laminin. Collagen I was detected near the end of the first trimester in the capsules and walls of interlobular veins. As the liver matures, collagen I is increasingly abundant in the capsules, portal area connective tissues, arterial walls, interlobular veins, sinusoids, and central veins. Collagen III and collagen IV appear in the middle of the first trimester in the capsules, portal areas, and walls of central veins, as well as the sinusoids particularly. In trimesters 2 and 3, these collagens are increasingly present in all the structures, but collagen IV is also present in nerve fibers. Laminin is sporadically present adjacent to the sinusoids in trimester 1, while in trimesters 2 and 3 this protein commonly appears in the walls of arteries and interlobular veins, in the basal membrane of bile ducts, and in nerve fibers. The contents of collagen I, III, and IV increase during prenatal development in the liver capsule, arterial and vein walls, sinusoids, and portal area. Laminin expression is consistent with that of the collagens with the exception that, within lobules, laminin disappears with liver maturation.

Immunohistochemical Heterogeneity of the Endothelium of Blood and Lymphatic Vessels in the Developing Human Liver and in Adulthood.

The endothelium of liver sinusoids in relation to the endothelium of other blood vessels has specific antigen expression similar to the endothelium of lymphatic vessels. Bearing in mind that there is no consensus as to the period or intensity of the expression of certain antigens in the endothelium of blood and lymphatic vessels in the liver, the aim of our study was to immunohistochemically investigate the dynamic patterns of the expression of CD31, CD34, D2-40, and LYVE-1 antigens during liver development and in adulthood on paraffin tissue sections of human livers of 4 embryos, 38 fetuses, 6 neonates, and 6 adults. The results show that, in a histologically immature liver at the end of the embryonic period, CD34 molecules are expressed only on vein endothelium localized in developing portal areas, whereby the difference between portal venous branches and CD34-negative central veins belongs to the collecting venous system. In the fetal period, with aging, expression of CD34 and CD31 molecules on the endothelium of central veins and blood vessels of the portal areas increases. Sinusoidal endothelium shows light and sporadic CD34 immunoreactivity in the late embryonic and fetal periods, and is lost in the neonatal and adult periods, unlike CD31 immunoreactivity, which is poorly expressed in the fetal and neonatal periods but is present in adults. The endothelium of sinusoids and lymphatic vessels express LYVE-1, and the endothelium of lymphatic vessels express LYVE-1 and D2-40 but not CD34. Similarity between the sinusoidal and lymphatic endothelium includes the fact that both types are LYVE-1 positive and CD34 negative.

Immunohistochemical features of multifocal and multicentric lobular breast carcinoma

PURPOSE Patient age, tumor size, axillary lymph node status, expression of estrogen, progesterone and HER2 receptors, as well as the histological grade, are widely accepted prognostic and predictive parameters in breast carcinoma. In invasive lobular carcinoma (ILC), the prognostic factors, such as nodal status and tumor size are believed to be the most valuable ones. The aim of this was set to determine the possible linkage between MFity/MCity of ILC and immunohistochemical predictive (ER, PR, HER2) and prognostic parameters (BRCA1, p53, E-cadherin, Ki-67). MATERIAL/METHODS Out of 2486 cases diagnosed with BC from south-eastern Serbia, the presence ILC was noted in 334 cases. Immunohistochemical characterization of predictive and prognostic parameters in ILC was done. RESULTS The occurrence of multifocal (MFC) and multicentric carcinoma (MCC) was observed in 18.9% of ILC. Bilateral (BL) BCs were found to be statistically significantly more frequent in younger women, compared to those with MFC, MCC or nonMFC/MCC/BL. No significant correlation was found between MFC/MCC and the presence of axillary lymph node metastases, and expression of immunohistochemical predictive and prognostic parameters. Based on literature data and the findings from the current work, MFity/MCtiy might represent negative morphologic prognostic parameters in ILC. CONCLUSIONS In 334 cases analyzed, no statistically significant correlations were observed between MF/MC and the expression of immunohistochemical predictive and prognostic parameters.

D2-40 Immunoreactivity of Lymphatic Vessels Endothelium and Representation of Lymphatic Vessels in the Liver of Human Fetuses of Different Gestational Age

Summary In the reference literature, there are a few studies on the development of the lymphatic system in the liver, especially human. This study aims to establish the presence, time of appearance, distribution and representation of expression D2-40 molecule – a marker of lymph vessels endothelial cells during the fetal period of the human liver development. The livers obtained from 20 human fetuses (10 male and 12 female), aged 12-37 gestational weeks, constituted our study material. Paraffin sections, 4 µm thick, were stained with hematoxylin and eosin for histological analysis, and with LSAB2/HRP method for immunohistochemistry using the D2-40 monoclonal antibody to mark lymphatic endothelial cells. The presence of lymphatic vessels was determined by morphometry, calculating their numerical and volume density. The study showed that expression of D2-40 molecule was absent in the liver lymphatic vessels in the first trimester of development, while in the second trimester intensive D2-40 immunoreactivity was observed in the lymph vessels of the liver capsule, and low D2-40 immunopositivity of the lymph vessels in large portal spaces. In the third trimester, intensive D2-40 immunoreactivity was observed in the lymph vessels of the liver capsule and in the endothelium of numerous lymphatic vessels of various shape and size, located in the smaller and larger portal areas. Volume and numerical density of lymphatic vessels in the portal areas of the liver during fetal development increased from the second to the third trimester of pregnancy, which was proportional to the increase in volume density of the hepatic portal spaces. Based on the obtained results, a conclusion may be drawn that the lymph vessels in the liver can be identified in the first half of the second trimester, and their number was growing proportionally by the end of pregnancy.