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Background and Aims: Oral bacteria play an important role in oral diseases, due to their high adaptability to different environmental areas of the mouth. In this article, an attempt was made to describe the molecular mechanisms involved in the physiological relationships of oral and dental environment bacteria and their pathogenic significance with molecular approaches. Materials and Methods: The present systematic review was written based on the advanced and standard search of keywords including Oral bacteria, Biofilm, and Dental diseases in PubMed, Springer, Scopus, Medline, Google Scholar, Science Direct, and Web of Science databases. For this purpose, an advanced and systematic search of articles published from 1993 to 2023 was conducted to compile the present article. Results: Bacteria in the oral cavity have nutritional adaptations that are important for living in pathogen-host relationships, including adapting to proteolytic living conditions, using the host's glycome as a nutritional interface. This includes the use of host-derived sialic acid and other glycosidases in oral bacteria. Some of these bacteria adhere to surfaces such as salivary, epithelial proteins, and glycans, which ultimately lead to biofilm formation. Bacteria living in the oral environment are constantly exposed to a wide range of stress-causing factors and oxidative stress in the biofilm. Conclusion: Dental caries, pulp, periapical, and periodontitis diseases (including gingivitis) are among the most common bacterial diseases. Among them, tooth decay caused by the presence of Streptococcus mutans is the most common dental disease due to the production of acids from carbohydrate fermentation which is characterized by the demineralization of tooth structure. [ABSTRACT FROM AUTHOR]

Introduction: The scorpion of Androctonus crassicauda belongs to the Buthidae family, it has a strong and deadly venom for humans, and every year there are cases of death due to the sting of this scorpion. The purpose of this study is the biological evaluation of the venom of this scorpion, the production of monovalent antivenom against it, and the evaluation of the effectiveness of the produced antivenom. Methods: The A. crassicauda scorpions were collected from different cities of Khuzestan province and milked by electric shock. In this research, the amount of venom protein, lethal dose 50 (LD50), immune response of horses, purification of antibodies, effectiveness of antivenom (ED50), degree of neutralization of venom with antivenom and the effect of monovalan antivenom in neutralizing the activity of hyaluronidase enzyme were evaluated. This research has been approved by the Ethics Committee of the Razi Vaccine and Serum Research Institute with code IR.RVSRI.REC.1401.017. Results: The amount of protein and LD50 of the venom from studied scorpion were calculated to be 78 mg/ml and 11.27 µg per mouse, respectively. The results of measuring the antibody titer at different times of venom injection showed the increase in the immune response of horses against the venom. The value of ED50 was around 9 LD50 and 92.22 µg per mouse. According to the results, scorpion venom has hyaluronidase enzyme activity, and 10 µL of the produced pure antivenom was able to neutralize 100% of the venom's hyaluronidase activity. Conclusions: In this project, extracted venom and produced antivenom showed their effectiveness. The produced antivenom was able to neutralize the venom in mice and prevented the death of the envenomed mice [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to determine the effect of Titanium carbide nanoparticles on stemness and senescence markers of mouse bone marrow derived mesenchymal stem cells. Methods: After isolation of mesenchymal stem cells from mouse’s bone marrow, their surface markers were studied using flowcytometry. MTT assay, cell cycle analysis; colony forming assay, and senescent beta galactosidase staining were performed for cells treated with titanium carbide nanoparticles. Then, the expression of OCT-4 and Nanog genes were studied by qRT-PCR in titanium carbide treated mouse’s bone marrow mesenchymal stem cells (mBMSCs). Results: All mBMSCs showed spindle shaped morphology. Their identity was confirmed by flow cytometry of stained cells for CD11b, CD90, CD45, and CD44 markers. The MTT assay results showed that titanium carbide effect is time-dependent and no cytotoxic effects were observed in short treatment times. But toxic effects were observed after 72 or 144 hours of post treatment with doses range from 0.1 to 1 mM (P<0.05). Besides, cell cycle study detected more cell populations in G0/G1 and less percentage in S phase. The colony forming assay in treated cells exhibited smaller size of colonies. The beta galactosidase staining of treated cells demonstrated more positive cells (more aged cells). Finally, qRT-PCR showed significant down regulation of OCT-4 and Nanog (p<0.05). Conclusion: Titanium carbide as an implant material could affect the viability, stemness and senescence of mBMSCs in negative manner. [ABSTRACT FROM AUTHOR]

Background: Bacteria are one of the important sources of producing enzymes. The aim of this study was to the isolate the halophilic bacteria producing amylase, lipase and pectinase from saline soil of the center of Iran. Methods: In this study, soil samples were collected from Dagh Biarjmand and Haj Aligholi in Semnan province. At first, isolated halophilic bacteria were cultured and screened for producing of hydrolytic enzymes including amylase, lipase and pectinase using enzyme-specific media. The enzymatic activities of isolates were recognized by induction of growth inhibition zone and/or precipitation around colonies after addition of related indicators. Afterward, enzyme positive isolates were identifies using the 16S rRNA sequencing. Results: Out of 7 bacterial isolates, 4 bacteria with amylase activity, 6 bacteria with lipase activity and 3 bacteria with pectinase activity were recognized and identified. Results showed that 2 isolates with the ability of producing all three types of enzymes belong to Bacillus genus using molecular identification methods. Furthermore, the halophilic bacteria producing amylase and pectinase were belonging to Bacillus and Halobacillus genera. Besides, bacteria producing lipase belonged to Bacillus and Virgibacillus genera. Conclusion: The Bacillus bacteria isolated from the soil can produce all three amylase, pectinase and lipase enzymes. [ABSTRACT FROM AUTHOR]

Background and Aims: Food contamination by fungi threatens human health. Active packaging containing antifungal compounds is a novel method to increase the safety and preservation of food. The aim of this study was to produce and investigate the antifungal properties of poly-lactic acid active film containing iron nanoparticles in grape juice packaging. Materials and Methods: Poly-lactic acid nanocomposite films were prepared by casting method through adding different amounts of nanoparticles (0, 2 and 4%) to 4% (w/w) solution of poly-lactic acid in chloroform and antifungal effect of films were investigated in in vitro and grape juice packaging. For this purpose, circular disks (6 mm) of film were prepared and placed on Potato Dextrose Agar media culture inoculated whit Aspergillus niger, Penicillium notatum, Botrytis cinerea. The diameter of the zone of inhibition was reported based on millimeters after 5 days of incubation of the plates at 27 ° C. In order to investigate the antifungal effect of nanocomposite in packaging of grape juice, 5×104 cfu/ml of these molds were inoculated to pasteurized grape juice and then packed with termal sewing and after a 15-days period, the molds population was counted. Results: The distribution of nanoparticles in the polymer, was uniform at concentration of 2% and formed agglomerate at concentration of 4%. The results of the disc diffusion test showed that adding of nanoparticles to the film caused antifungal effect against the tested fungi and this property increased with increasing percentage of nanoparticles. Also, the results of the study on the antifungal effect in grape juice packaging in the 15-days period showed that the population of fungi had an inverse relationship with concentrations of iron nanoparticles in grape juice samples. A. niger showed the most and B. sinera showed the least resistance to this nanoparticle. Conclusions: Significant compatibility between iron nanoparticles and poly lactic acid provides the possibility of producing poly-lactic acid nanocomposite as an alternative for synthetic polymers from petroleum derivatives. Iron nanoparticles produce anti-fungal effects through the leakage of lactase dehydrogenase from the cell wall, impairment in mitochondrial function, chromosomes compression, and production of free radicals of oxygen. Due to the antifungal effect of iron nanoparticles, its application in poly-lactic acid film decreases fungal growth and, as a result, increases the shelf-life of foods. [ABSTRACT FROM AUTHOR]