Circular RNA-Mediated Regulation of Oral Tissue-Derived Stem Cell Differentiation: Implications for Oral Medicine and Orthodontic Applications

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNAs (ncRNAs) which unlike linear RNAs, have a covalently closed continuous loop structure. circRNAs are found abundantly in human cells and their biology is complex. They feature unique expression to different types of cells, tissues, and developmental stages. To the present, the functional roles of circular RNAs are not fully understood. They reportedly act as microRNA (miRNA) sponges, therefore having key regulatory functions in diverse physiological and pathological processes. As for dentistry field, lines of evidence indicate that circRNAs play vital roles in the odontogenic and osteogenic differentiation of dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs). Abnormal expression of circRNAs have been found in other areas of pathology frequently reflected also in the oral environment, such as inflammation or bone and soft tissue loss. Therefore, circRNAs could be of significant importance in various fields in dentistry, especially in bone and soft tissue engineering and regeneration. Understanding the molecular mechanisms occurring during the regulation of oral biological and tissue remodeling processes could augment the discovery of novel diagnostic biomarkers and therapeutic strategies that will improve orthodontic and other oral therapeutic protocols.

Predictors for anaemia, blood transfusion and outcome in plastic surgery patients

OBJECTIVE

In patients undergoing plastic surgery, to identify specific risk factors for anaemia and use of blood products, and assess their impact on patient outcome.

METHOD

For this retrospective study, data were analysed from patients who attended the Plastic Surgery Department at our hospital over a three-year period (2018 to 2020). Adult patients who presented with traumatic injuries, oncologic patients who underwent reconstructive procedures, and patients with soft tissue infections (STIs) who required plastic surgery for tissue coverage were included. Demographic and injury data, hospital admission characteristics, surgical procedures, laboratory test results, transfusion events, and in-hospital complications were extracted from patient records.

RESULTS

Of the 350 patients included in the study, 228 (65%) presented with trauma, 76 (22%) underwent reconstructive surgery for cancers and 46 (13%) had STIs. In total, 175 (50%) patients developed anaemia, and 37 (11%) received blood transfusions; these were 20 (54%), 5 (14%), and 12 (32%) patients in the trauma, cancer and STI groups, respectively. Associated comorbidities and upper and lower limb surgery were the most significant risk factors for anaemia, while the number of surgeries and NSTIs were identified as risk factors for blood transfusions. Direct wound closure was consistently a protective factor for both anaemia and blood transfusions. Blood transfusions were independently associated with a high risk of sepsis, wound complications, and prolonged hospital stay.

CONCLUSION

While transfusions are necessary and even lifesaving in surgical patients, blood is a finite resource and its use may negatively impact patient outcome. Therefore, ongoing research must focus on providing safe and restrictive clinical practices while developing sustainable and accessible alternatives.

Anti-inflammatory and antioxidant efficacy of lavender oil in experimentally induced thrombosis

BACKGROUND

Lavender oil (LO) possesses anti-inflammatory, antioxidant, antifungal, antibacterial, sedative, cardio-protective, and antinociceptive properties. Thrombosis and inflammation are interplayed processes that interact and influence one another. Our research compared three routes of administration to assess the efficacy of pretreatment with LO on carrageenan-induced thrombosis in rat tail.

MATERIALS AND METHODS

Wistar-Bratislava white rats were randomly divided into five groups of ten rats each and pretreated 3 consecutive days prior the inducement of thrombosis to with one dose of LO (150 mg/kg body weight (b.w.)): per os by gavage (TLOPO group), intraperitoneal (TIPLO group) and subcutaneous (TSCLO group). We also have a control (C, received saline solution 0.9% and DMSO (vehicle) 1 ml intraperitoneal (i.p.)) group and a group with thrombosis (T group, received saline solution 0.9% plus vehicle 1 ml i.p.). Histopathological examinations were conducted together with measurements of the circulating levels of three oxidative stress markers, antioxidant effect (TAC and THIOL), and three proinflammatory cytokines (TNF- α, RANTES, and MCP-1).

RESULTS

When administered intraperitoneally, lavender oil has the best efficacy on circulating levels of oxidative stress parameters (MDA, NOx, TOS), one oxidative stress marker (THIOL), and all studied proinflammatory cytokines (p-values < 0.02). Moreover, TIPLO displayed the closest values for bleeding and clotting time to the C group, as well as the lowest length of the thrombus than the T, TPOLO, and TSCLO groups (p-values < 0.001). The TIPLO group has histological appearance comparable to the C group, with the exception of the presence of oedema.

CONCLUSIONS

Lavender oil pretreatment with intraperitoneal administration as three days, one-dose per day, showed anti-inflammatory and antioxidant efficacy in experimentally induced thrombosis.

A novel step-by-step training program for transanal endoscopic surgery

BACKGROUND

The objective of our study is to develop an effective training platform for transanal endoscopic surgery and to validate a step-by-step training program for learning the basic skills necessary for this approach.

METHODS

We have designed a two-part study: an experimental study (with the aim to design the training platform and the training exercises - on synthetic and biological material) and a prospective analytical study, in order to validate the training program by enrolling as participants general surgery residents and specialists, without previous experience in transanal endoscopic interventions. The performance of the participants was assessed based on the time of completion, as well as the quality of the execution.

RESULTS

We have developed three different diameter platforms (5 cm, 7.5 and 10 cm), that can be used with both the TEO and TAMIS platforms; specific exercises were developed to train different surgical skills like manipulation of tissue, cutting, dissection and suturing. Forty participants were enrolled for the validation of the proposed training program (12 young residents, 16 senior residents and 12 specialist surgeons). A statistically significant improvement of the performance time, from round to round, was observed for all participants in all exercises. The time of completion for the exercises, considering the correct technical execution, was the shortest for more experienced surgeons: specialist surgeons, followed by senior residents and young residents. The biological material exercises, that closely recreate intraoperative conditions and had more strict technical requirements, were difficult to be performed by young residents; better completion rates were seen in senior residents, while all the participants in the specialist surgeons group have completed these exercises.

CONCLUSIONS

Our training program is an effective simulation based educational model for recreating intraoperative conditions particular to transanal endoscopic surgery. The proposed step-by-step training program has demonstrated to be useful in developing the important basic skills needed for transanal endoscopic surgery and assured the progress of all the participants, regardless of their surgical experience.

The Acute Effect of Trimethylamine-N-Oxide on Vascular Function, Oxidative Stress, and Inflammation in Rat Aortic Rings

A growing body of evidence suggests that the gut microbiota affects the cardiovascular system directly and indirectly via biologically active molecules. TMAO, a key metabolite produced by gut bacteria is implicated in atherosclerosis and chronic endothelial dysfunction, but with an unclear effect on vascular tone, oxidative stress, and inflammation. Our study aimed to evaluate the acute effects of TMAO on vascular contractility in relation with oxidative stress markers and inflammation. Aortic rings were harvested from laboratory rats and placed in a tissue bath system containing TMAO in concentrations of 300, 100, 10 µM, and control. Vascular tone under the influence of vasoconstrictor phenylephrine and non-endothelial-dependent vasodilator sodium nitroprusside was assessed using force transducers connected to a computer-based acquisition system. Oxidative stress and inflammation were quantified by vascular assessment of the activity of NF-κB, NRF2, SOD1, and iNOS by western-blotting and MDA by spectrofluorimetry. After the incubation of the aortic rings in TMAO solutions for 1 h, there was no difference in vasoconstrictor and non-endothelial vasodilator response between the studied doses. TMAO acutely induced oxidative stress and inflammation, significantly increasing levels of MDA and the expression of NF-κB, NRF2, SOD1, and iNOS, mostly in a dose-dependent manner. Our study showed the lack of a short-term effect of studied TMAO doses on vascular contractility, but demonstrated an acute prooxidative effect and activation of major inflammatory pathways, which can partially explain the detrimental effects of TMAO in cardiovascular disease.

PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor for patients with intrahepatic cholangiocarcinoma

Cholangiocarcinoma, the second most common liver malignancy, after hepatocarcinoma is highly aggressive and usually diagnosed in advanced cases. In the era of personalized medicine, targeted therapy protocols are limited for cholangiocarcinoma and the only potential curative treatment, surgical resection, is seldom applicable.This retrospective study included all cases with pathology-confirmed intrahepatic cholangiocarcinoma admitted in a tertiary healthcare facility during a 10-year timeframe. Clinical information, laboratory values, imaging studies, and survival data were retrieved, and PD-L1 immunostaining was performed on representative pathology slides, for each case. From the total of 136 included cases (49 surgical resections and 87 liver biopsies), 38.97% showed PD-L1 positivity on tumoral cells, 34.8% on tumor infiltrating immune cells, 10.11% on epithelial cells within the peritumoral area and 15.95% on immune cells from the peritumoral area. Overall survival was significantly higher in the first two scenarios. However, after adjusting for age, tumor number, tumor size, and tumor differentiation in a multivariate analysis, only PD-L1 positivity on tumor infiltrating immune cells remained a favorable prognostic for survival. High immune cell counts also correlated with increased overall survival.Our study demonstrated that PD-1/PD-L1 checkpoint pathway in the microenvironment of intrahepatic cholangiocarcinoma bears prognostic significance. PD-L1 expression on immune cells, in both resection and biopsy specimens, might be a strong independent predictor for a favorable outcome.

Vitamin D Supplementation: Oxidative Stress Modulation in a Mouse Model of Ovalbumin-Induced Acute Asthmatic Airway Inflammation

Asthma oxidative stress disturbances seem to enable supplementary proinflammatory pathways, thus contributing to disease development and severity. The current study analyzed the impact of two types of oral vitamin D (VD) supplementation regimens on the redox balance using a murine model of acute ovalbumin-induced (OVA-induced) asthmatic inflammation. The experimental prevention group received a long-term daily dose of 50 µg/kg (total dose of 1300 µg/kg), whereas the rescue group underwent a short-term daily dose of 100 µg/kg (total dose of 400 µg/kg). The following oxidative stress parameters were analyzed in serum, bronchoalveolar lavage fluid (BALF) and lung tissue homogenate (LTH): total oxidative status, total antioxidant response, oxidative stress index, malondialdehyde and total thiols. Results showed that VD significantly reduced oxidative forces and increased the antioxidant capacity in the serum and LTH of treated mice. There was no statistically significant difference between the two types of VD supplementation. VD also exhibited an anti-inflammatory effect in all treated mice, reducing nitric oxide formation in serum and the expression of nuclear factor kappa B p65 in the lung. In conclusion, VD supplementation seems to exhibit a protective role in oxidative stress processes related to OVA-induced acute airway inflammation.

Chitosan Functionalized Magnetic Nanoparticles to Provide Neural Regeneration and Recovery after Experimental Model Induced Peripheral Nerve Injury

(1) Background: Peripheral nerve injuries have a great impact on a patient's quality of life and a generally poor outcome regarding functional recovery. Lately, studies have focused on different types of nanoparticles and various natural substances for the treatment of peripheral nerve injuries. This is the case of chitosan, a natural compound from the crustaceans' exoskeleton. The present study proposes to combine chitosan benefic properties to the nanoparticles' ability to transport different substances to specific locations and evaluate the effects of magnetic nanoparticles functionalized with chitosan (CMNPs) on peripheral nerve injuries' rehabilitation by using an in vivo experimental model. (2) Methods: CMNPs treatment was administrated daily, orally, for 21 days to rats subjected to right sciatic nerve lesion and compared to the control group (no treatment) by analyzing the sciatic functional index, pain level, body weight, serum nerve growth factor levels and histology, TEM and EDX analysis at different times during the study. (3) Results: Animals treated with CMNPs had a statistically significant functional outcome compared to the control group regarding: sciatic functional index, pain-like behavior, total body weight, which were confirmed by the histological and TEM images. (4) Conclusions: The results of the study suggest that CMNPs appear to be a promising treatment method for peripheral nerve injuries.

Celecoxib as a Valuable Adjuvant in Cutaneous Melanoma Treated with Trametinib

BACKGROUND

Melanoma patients stop responding to targeted therapies mainly due to mitogen activated protein kinase (MAPK) pathway re-activation, phosphoinositide 3 kinase/the mechanistic target of rapamycin (PI3K/mTOR) pathway activation or stromal cell influence. The future of melanoma treatment lies in combinational approaches. To address this, our in vitro study evaluated if lower concentrations of Celecoxib (IC50 in nM range) could still preserve the chemopreventive effect on melanoma cells treated with trametinib.

MATERIALS AND METHODS

All experiments were conducted on SK-MEL-28 human melanoma cells and BJ human fibroblasts, used as co-culture. Co-culture cells were subjected to a celecoxib and trametinib drug combination for 72 h. We focused on the evaluation of cell death mechanisms, melanogenesis, angiogenesis, inflammation and resistance pathways.

RESULTS

Low-dose celecoxib significantly enhanced the melanoma response to trametinib. The therapeutic combination reduced nuclear transcription factor (NF)-kB (p < 0.0001) and caspase-8/caspase-3 activation (p < 0.0001), inhibited microphthalmia transcription factor (MITF) and tyrosinase (p < 0.05) expression and strongly down-regulated the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway more significantly than the control or trametinib group (p < 0.0001).

CONCLUSION

Low concentrations of celecoxib (IC50 in nM range) sufficed to exert antineoplastic capabilities and enhanced the therapeutic response of metastatic melanoma treated with trametinib.

Methylene Blue and Proflavine as Intraarterial Marker for Functional Perforazome-Comparative Study

Methylene blue (MB) is both a dye and a medicine known and used for a long time including as lymphatic tracer in melanoma and breast cancer for revealing sentinel lymph nodes. Proflavine (PRO) is an acriflavine dye, used as bacteriostatic disinfectant against many gram-positive bacteria that was also successfully applied to evaluate morphopathological changes in tissues. This study was performed on a group of twenty-eight Wistar rats and had as its main objective the in vivo evaluation of the use of MB and PRO as perforator tracers. The two dyes proved to be effective functional perforasome tracers with medium inflammatory infiltrate in the skin of the island perforator flap which heals perfectly at 14 days with complete absence of the inflammatory reaction. At the same injected amount, PRO seems to determine a greater inflammatory reaction compared with MB, but in smaller concentration, the inflammatory response is absent in the case of PRO. In conclusion, both substances tested within this in vivo study are good functional perforasome tracers, but PRO has the advantage of the absence of inflammatory reaction when using lower concentrations, while preserving unalerted its efficiency as tracer.