The temporal expression of estrogen receptor alpha-36 and runx2 in human bone marrow derived stromal cells during osteogenesis.

During bone maintenance in vivo, estrogen signals through estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived stromal cells (BMSC). This was assessed in relation to runt-related transcription factor-2 (runx2), a main modulatory protein involved in bone formation. ERα36 and runx2 subcellular localisation was assessed using immunocytochemistry, and their mRNA expression levels by real time PCR throughout the process of osteogenesis. The osteogenically induced BMSCs demonstrated a rise in ERα36 mRNA during proliferation followed by a decline in expression at day 10, which represents a change in dynamics within the culture between the proliferative stage and the differentiative stage. The mRNA expression profile of runx2 mirrored that of ERα36 and showed a degree subcellular co-localisation with ERα36. This study suggests that ERα36 is involved in the process of osteogenesis in BMSCs, which has implications in estrogen deficient environments.

Identification of the Ideal Reference Site and Pain Threshold Values for the Placement of Electric Pulp Testers in Permanent Upper and Lower Anterior Teeth: A Cross-Sectional Study.

INTRODUCTION: Electric pulp testers (EPTs) are widely used diagnostic tools for diagnosing traumatized teeth. Several factors can affect the result of an electric pulp test. One such factor that will affect the diagnosis is the electrode tip placement. Hence, the current study aims to identify the most painful site and response time threshold in healthy anterior teeth. METHODS: A total of 90 individuals, 48 male and 42 female, aged 19 to 25 years, were recruited. An EPT was placed on three different sites: the cervical, middle, and incisal third of the labial surface of both upper and lower anterior teeth (central incisor, lateral incisor, and canine) with an appropriate electrolyte as a conducting medium. Later, the threshold values were recorded, and pain assessment was done using the Memojis pain scale (MPS). Finally, the data was analyzed statistically using the Mann-Whitney U test. RESULTS: Mean and standard deviation values of reaction time were collected from 540 EPT readings (three sites from 180 teeth). Among the three sites tested, the difference between the upper and lower central incisors was statistically insignificant (p > 0.05). Similarly, when upper and lower lateral incisors and canines were compared, a statistically significant difference was observed among the three sites (p<0.05). There was a significant difference (p<0.05) in the pain scores only on the incisal and cervical thirds of the upper and lower central incisors. Only the incisal third showed a statistically significant difference (p<0.05) between the pain scores in the upper and lateral incisors. At the same time, a statistically significant difference in the pain scores was observed among the three tested sites between the upper and lower canines (p<0.05).  Conclusion: Lower threshold values were appreciated at the incisal third of all the upper and lower anterior teeth for placing the EPT. Most individuals have experienced a score of 2 (hurts little bit) for the perceived pain using EPTs for both the upper and lower anterior teeth.

Antimicrobial Efficacy of Triple Antibiotic Paste and Propolis as an Intracanal Medicament in Young Permanent Teeth: An In Vivo Study.

AIM AND OBJECTIVE: To evaluate the antimicrobial efficacy of triple antibiotic paste and propolis extracts as an intracanal medicament in young permanent teeth. MATERIALS AND METHODS: A total of 30 single-rooted non-vital young permanent teeth with open apex were selected randomly from the children aged between 7 years and 14 years with no systemic complications. Group I-triple antibiotic paste and group II be propolis allocating 15 teeth in each group. After access opening, the first sample (S1) was collected by inserting paper point into the root canal, the second sample (S2) was collected immediately after irrigation, and the third sample (S3) was collected after post-intracanal medication after 3-4 weeks. Samples were sent for microbiological analysis to assess the bacterial count, and for the obtained data, statistical analysis was done. RESULTS: The mean colony count among the triple antibiotic paste group was 1906.75. After access opening, which was reduced to 315.12 after irrigation, and after 3-4 weeks, it was 817.25. There was a significant difference between sample 1, sample 2, and sample 3 (p value = 0.008). The mean colony count among the propolis group was 1427.87 after access opening, which was reduced to 436.00 after irrigation, and after 3-4 weeks, it has reduced to 252.37. There was a significant difference between sample 1, sample 2, and sample 3 (p value = 0.032). Intergroup comparison between the groups showed no statistical difference between the samples. CONCLUSION: Propolis exhibited similar antimicrobial efficacy, which is comparable to triple antibiotic paste. So, propolis can be utilized as an intracanal medicament in young permanent teeth with an open apex. CLINICAL SIGNIFICANCE: Propolis is a naturally occurring flavonoid-rich resinous product with antibacterial, antifungal, antiviral, immunomodulatory, and antioxidant effects. It is safe without any drug allergies and bacterial sensitivity and is a promising alternative to triple antibiotic paste for disinfecting non-vital young permanent teeth. HOW TO CITE THIS ARTICLE: Lillygrace E, Kethineni B, Puppala R, et al. Antimicrobial Efficacy of Triple Antibiotic Paste and Propolis as an Intracanal Medicament in Young Permanent Teeth: An In Vivo Study. Int J Clin Pediatr Dent 2021;14(2):243-248.

Signal transducer and activator of transcription-3 licenses Toll-like receptor 4-dependent interleukin (IL)-6 and IL-8 production via IL-6 receptor-positive feedback in endometrial cells.

Interleukin 6 (IL-6), acting via the IL-6 receptor (IL6R) and signal transducer and activator of transcription-3 (STAT3), limits neutrophil recruitment once bacterial infections are resolved. Bovine endometritis is an exemplar mucosal disease, characterized by sustained neutrophil infiltration and elevated IL-6 and IL-8, a neutrophil chemoattractant, following postpartum Gram-negative bacterial infection. The present study examined the impact of the IL6R/STAT3 signaling pathway on IL-8 production by primary endometrial cells in response to short- or long-term exposure to lipopolysaccharide (LPS) from Gram-negative bacteria. Tyrosine phosphorylation of STAT3 is required for DNA binding and expression of specific targets genes. Immunoblotting indicated constitutive tyrosine phosphorylation of STAT3 in endometrial cells was impeded by acute exposure to LPS. After 24 h exposure to LPS, STAT3 returned to a tyrosine phosphorylated state, indicating cross-talk between the Toll-like receptor 4 (TLR4) and the IL6R/STAT3 signaling pathways. This was confirmed by short interfering RNA targeting the IL6R, which abrogated the accumulation of IL-6 and IL-8, induced by LPS. Furthermore, there was a differential endometrial cell response, as the accumulation of IL-6 and IL-8 was dependent on STAT3, suppressor of cytokine signaling 3, and Src kinase signaling in stromal cells, but not epithelial cells. In conclusion, positive feedback through the IL6R amplifies LPS-induced IL-6 and IL-8 production in the endometrium. These findings provide a mechanistic insight into how elevated IL-6 concentrations in the postpartum endometrium during bacterial infection leads to marked and sustained neutrophil infiltration.

Centaurin-alpha1 and KIF13B kinesin motor protein interaction in ARF6 signalling.

The ARF (ADP-ribosylation factor) family of small GTPases regulate intracellular membrane trafficking by cycling between an inactive GDP- and an active GTP-bound form. Among the six known mammalian ARFs (ARF1-ARF6), ARF6 is the least conserved and plays critical roles in membrane trafficking and cytoskeletal dynamics near the cell surface. Since ARFs have undetectable levels of intrinsic GTP binding and hydrolysis, they are totally dependent on extrinsic GEFs (guanine nucleotide-exchange factors) for GTP binding and GAPs (GTPase-activating proteins) for GTP hydrolysis. We have recently isolated a novel KIF (kinesin) motor protein (KIF13B) that binds to centaurin-alpha1, an ARF6GAP that binds to the second messenger PIP3 [PtdIns(3,4,5)P3]. KIFs transport intracellular vesicles and recognize their cargo by binding to proteins (receptors) localized on the surface of the cargo vesicles. Identification of centaurin-alpha1 as a KIF13B interactor suggests that KIF13B may transport ARF6 and/or PIP3 using centaurin-alpha1 as its receptor. This paper reviews the studies carried out to assess the interaction and regulation of centaurin-alpha1 by KIF13B.