Investigating the cytotoxic effects of the venom proteome of two species of the Viperidae family (Cerastes cerastes and Cryptelytrops purpureomaculatus) from various habitats

Animal secretions are of great interest in terms of drug development due to their complex protein and peptide composition. Especially, in the field of therapeutic medications such as anti-cancer drugs snake venoms receive attention. In this study we report of two Viperidae species from various habitats with a particular focus on the cytotoxic potential along with the decomplexation of the venom proteome: the horned desert viper (Cerastes cerastes), native to desert regions of North Africa and the mangrove pit viper (Cryptelytrops purpureomaculatus), found in coastal forests of Southeast Asia. Initial cytotoxic screenings of the crude venoms revealed diverse activity, with the highest effect against SHSY5Y human glioblastoma carcinoma cells compared to other cancerous and non-cancerous cell lines. In-depth cytotoxicity studies of SHSY5Y cells with purified venom fractions revealed dimeric disintegrins from C. cerastes venom which exerted a high cytotoxic activity with IC50 values from 0.11 to 0.58µM and the disintegrins-like effect on SHSY5Y morphology was observed due to cell detachment. Furthermore, two polyproline BPP-related peptides, one PLA2 and a peptide-rich fraction were determined for C. purpureomaculatus with moderate IC50 values between 3-51µM. Additionally, the decryption of the venom proteomes by snake venomic mass spectrometry and comparison of same species from different habitats revealed slight differences in the composition.

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COVID-19 has been recognized at the end of 2019 and has been recognized in more than 215 countries with more than 24 million reported cases. Dental practitioners were regarded under high risk of getting COVID-19 due to their working environment and the mode of transmission of the virus. Present study aimed to evaluate the awareness and assessing the knowledge of dental students and dentists on COVID-19. The study population consisted of undergraduate students who are currently studying dentistry in Cyprus. Students were sent an onlinesurvey and data were collected on 16th of April. Survey was comprised of questions about the demography, education level of the participants, their infection control knowledge, conditions that require treatment during pandemic. A total of 594 students with equal gender distribution joined the survey. The age group of the participants were mostly between 18-25 age (94%) with 63% pre-clinical and 37% clinical students. The majority of participants were aware that dentists were at high risk group in terms of COVID-19 (98.5%). When clinical questions were asked, data indicatedstrong relationship between participants’ responses with their level of study. Upon asking COVID-19 specific questions, participants that have taken microbiology course were reported to have higher correct answer rate. Dental students studying in Cyprus demonstrated high awareness of COVID-19 and the higher risks of COVID-19 exposure that dental professionals face. Study demonstrated the importance of microbiology courses, as it significantly affected the answers to the questions on diagnosis methods and immune response to COVID-19.

This study was conducted to understand the cellular proliferative effect of Photobiomodulation Therapy (PBMT) on thawed dental pulp stem cells (DPSCs) stored for 2 years. For this purpose, cells were exposed to PBMT for short period of time to evaluate the most appropriate PBMT parameter for stimulating cellular proliferation that can be used for future tissue engineering therapies. Fully characterized DPSCs were seperated into three groups according to the laser energy densities (5[Formula: see text]J/cm2 or 7[Formula: see text]J/cm2) applied and a group was served as control in which cells did not receive any laser irradiation. The cells in laser-irradiated groups were further divided into two subgroups according to the period of application (24[Formula: see text]h and 0[Formula: see text]h) and exposed to Gallium–Aluminum–Arsenide diode laser irradiation. Cell viability and the proliferation rate of the cells were analyzed with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, any PBMT related cellular cytotoxicity were determined by performing a lactate dehydrogenase assay (LDH) and statistical analysis of data were performed. The percentage of proliferation seemed to increase upon laser therapy in both different doses of irradiation (5[Formula: see text]J/cm2 and 7[Formula: see text]J/cm2). DPSCs showed significantly higher proliferation rate upon 7[Formula: see text]J/cm2 irradiation in both 0[Formula: see text]h and 24[Formula: see text]h when compared to control groups. However, DPSCs irradiated with 5[Formula: see text]J/cm2 dose induced relatively lower proliferation rate when compared to 7[Formula: see text]J/cm2 dose of irradiation. According to the LDH data, PBMT exposure did not show any significant cytotoxicity at both energy densities in all different time periods. PBMT at 7[Formula: see text]J/cm2 should be an effective parameter to stimulate proliferation of long-term cryopreserved DPSCs in a short term time period. Photobiomodulation therapy may be an upcoming tool for future tissue enngineering and regenerative dentistry applications.

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Variants (Alfa, Gamma, Beta, and Delta) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are circulating worldwide. These variants of concerns share some common mutations but they also have distinguishing mutations. These mutations affect transmissibility of virus and cause evasion from neutralizing antibodies. Monitoring and identification of circulating variants is of great importance for public health. In this study, an in-house SARS-CoV-2 reverse transcription quantitative polymerase chain reaction (RT-qPCR) kit was designed to detect variants of concerns by the World Health Organization.Primer sets and probes were designed to target presence of virus along with mutations for identifying different variants (for N501Y, HV69–70del, K417N, and T478K). Reactions were set by using commercially available master mixes without a reference dye.The RT-qPCR conditions were optimized by using commercially available ribonucleic acid samples of wild-type, Alfa, Beta, Gamma, and Delta variants. Several samples were also analyzed by the in-house kit after optimization studies. All Alfa variant and wild-type samples were also double confirmed with a commercially available variant detection kit demonstrating a 100% consistence with the in-house kit. Beta, Gamma, and Delta variants could not be confirmed with any other commercially available kits as there is not any available one in the market.SARS-CoV-2 variants are gaining importance during the pandemic and shaping the fight against the virus. RT-qPCR kits detecting different variants would provide a significant advantage while screening the population.