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Pancreatic ductal adenocarcinoma (PDAC) is one of the most common malignant tumors of the pancreas. Preclinical studies show that it evades the immune system with immune checkpoints and promotes tumor development. V-domain Ig suppressor of T cell activation (VISTA) is a new immunecheck point from the B7 family and is highly expressed in cancer cells. Overexpression of toll like receptor 4 (TLR4) in pancreatic adenocarcinoma is associated with inducing tumorigenesis, tumor growth and resistance to chemotherapy. Naloxone is an opioid and inhibits TLR4-ligand association. In this study, we investigated the connection of TLR4 and downstream pathway with immune-check point VISTA in pancreatic cancer proliferation. We rst collected pancreatic cancer-related datasets using the GEPIA2 and UALCAN databases. Based on the data obtained the effect of different concentrations and incubation times of Naloxone were used on PANC-1 cells proliferation. Combination of Naloxone and VISTA-siRNA were applied, and effect of both Naloxone and combined reatment on TLR4, Interleukin 1 receptor associated kinase 4 (IRAK4) and VISTA gene expression were analysed in pancreatic cancer cells. As a result of analysis with Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR), gene expression levels of TLR4, IRAK4 and VISTA were signi cantly suppressed and cell proliferation was signi cantly reduced. We found that administration of Naloxone and VISTA-siRNA in combination to PDAC cells suppressed signaling. Therefore, we considered that the relationship between VISTA and TLR4 signaling pathways and the other possible associated signal molecules may be an important marker in determining the response of immune checkpoint inhibitors in cancer treatment.

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This study aims to investigate the effects of hyperbaric oxygen (HBO) therapy and platelet-rich plasma (PRP) on the regeneration of osteochondral defects of the rats, and the synergistic effect of this combined treatment. Materials and methods: This randomized, controlled, and interventional animal study was conducted between May 2014 and August 2014 Osteochondral regeneration was evaluated in four treatment groups (control, PRP, HBO, and HBO+PRP groups) at the 30 th day after iatrogenic injury. Thirty-two female Wistar albino rats (weighing 248-305 g) underwent arthrotomy and osteochondral surgery on left knees. The regenerations of defects were then examined histologically by the modified version of O'Driscoll score. Results: Groups that were treated with either HBO or PRP alone regenerated significantly better than the control group (p=0.01), while no significant difference was found between the HBO-and PRP-treated groups (p>0.05). The defects in group 4 (treated with both HBO and PRP) regenerated significantly better than the control group, the HBO-treated group alone, and the PRP-treated group alone (p=0.01). Conclusion: The results of this study showed a synergistic effect of HBO and PRP on knee cartilage regeneration. However, the possible underlying mechanisms should be the subject of future researches. The aggregation and activation of growth factors released from platelets whose activation is increased in the hyperbaric environment may explain this effect. This may result in a better regeneration than the effect of PRP or HBO alone.

Origanum L. is one of the high-value medicinal and aromatic plants generally used for various purposes in the field of food and health. This study evaluated the effect of aqueous extract, hydrosol and essential oil forms of seven Origanum taxa including three endemic species in fresh-cut mushroom samples in order to prevent polyphenol oxidase (PPO) activity. Food samples were treated with these natural preservatives (aqueous extract, hydrosol, and essantial oil) and stored at 4°C temperature for a maximum of 5 days. It was found that the extract form of Origanum vulgare L. subsp. hirtum (Link) Ietsw. provided maximum PPO inhibition with 64.50% of reduction on 3rd day. Similarly, 3-fold reduction in hydrosol application was observed with Origanum bilgeri P. H. Davis which is the endemic plant. These results were conducted with the extract forms containing water are more effective than essential oil form to inhibit PPO activity. Practical applications In this study, we have investigated alternative usage of some Origanum plants as natural anti-browning food additives in mushroom samples. The samples separately treated with aqueous extract, hydrosol, and essential oil forms of different Origanum plants were stored until 5 days. PPO activities of samples on 1st, 3rd, and 5th days were used to determinate the shelf life of mushrooms associating with their browness. How to cite this article: Tanhaş E, Martin E, Korucu EN, Dirmenci T. Effect of aqueous extract, hydrosol, and essential oil forms of some endemic Origanum L. (Lamiaceae) taxa on polyphenol oxidase activity in fresh-cut mushroom samples. J