The epigenetic nature of development mandates the observation of the effect of any exogenous substance, especially those with estrogenic activities, during critical phases of development. The submandibular gland (SMG) presents as a great model due to extensive postnatal development, and is known to be regulated and affected by hormones as well as growth factors. Herein, we observed postnatal development following low doses of Biochanin A (BCA) and 17β estradiol (E2) in rats. The pups were randomly divided into four groups: control, BCA, E2, and dimethyl sulfoxide (DMSO), and euthanized at the 6th, 15th, 30th, and 60th postnatal days (PND). SMG morphogenesis was assessed. The nuclear expression of estrogen receptor beta (ERβ) was evaluated immunohistochemically; ERβ expression was up-regulated by BCA and down-regulated by E2. Similarly, caspase three gene expression, assessed by real time polymerase chain reaction was increased in the BCA group but decreased in the E2 group. A significant decrease in epidermal growth factor gene expression was noted at PND 30. The results presented by this study provide evidence that the effect of a postnatal exposure of the SMG to Biochanin A during development could be linked to sex hormone-dependent disorders.
Over 700 bacterial species have been detected in the oral cavity. Several studies have suggested that periodontitis is associated with systemic disorders such as diabetes mellitus, indicating a key role for oral microbiota in human health. However, the relationship between oral microbiota and diabetes has not been well clarified. Therefore, we conducted microbiome analysis of saliva samples obtained from 15 elderly residents (3 with type 2 diabetes mellitus [DM] and 12 without diabetes [non-DM]) at three different nursing homes, as well as 9 young healthy controls (HC). Genomic DNA was extracted from each sample, and then the V4 region of the 16S rRNA gene was amplified and sequenced. Alpha diversity, in terms of operational taxonomic unit richness, was significantly higher in samples from the non-DM group than in those from the HC group. Weighted UniFrac distance analysis showed that salivary microbial communities in the DM group were separately clustered. Furthermore, in the DM group, Actinomyces and Selenomonas showed significantly higher abundance, whereas Alloprevotella showed significantly lower abundance, relative to the non-DM group. Although our findings were limited by the small sample size, oral bacterial diversity in the DM group was clearly different from that in the non-DM group.
We analysed the roles of orexin receptors in the effects of orexin-A on KCl-induced increases in intracellular calcium ion levels ([Ca2+]i) in C-fiber-like small neurons of rats with inflammation induced by intraplantar injection of carrageenan into the hind paw. Controls were treated with saline. Paw withdrawal and threshold forces in response to tactile stimuli were determined using von Frey filaments. [Ca2+]i in C-fiber-like neurons derived from dorsal root ganglia was visualised using a calcium fluorescence probe. Changes in neuronal [Ca2+]i were assessed as relative fluorescence intensity (F/F0). One day after carrageenan injection, the paw withdrawal response to tactile stimuli and the paw withdrawal threshold were increased and reduced, respectively. KCl loading of neurons from either carrageenan-treated or control rats increased F/F0 to about 2.0. KCl-induced increases in F/F0 of carrageenan-treated, but not control, rats were inhibited by orexin-A. The OX1 and OX2 receptor antagonist MK-4305, but not the OX1 receptor antagonist SB334867, counteracted the effects of orexin-A on the KCl-induced increase in F/F0. These results suggest that OX2, but not OX1 receptors mediate the inhibitory effect of orexin-A on KCl-induced increases in [Ca2+]i in C-fiber-like neurons of rats with inflammation.
The present study aimed to evaluate the characteristics and quality of statistical methodology used in clinical studies on dentin hypersensitivity management. An electronic search was performed for data published from 2009 to 2014 by using PubMed, Ovid/MEDLINE, and Cochrane Library databases. The primary search terms were used in combination. Eligibility criteria included randomized clinical trials that evaluated the efficacy of desensitizing agents in terms of reducing dentin hypersensitivity. A total of 40 studies were considered eligible for assessment of quality statistical methodology. The four main concerns identified were i) use of nonparametric tests in the presence of large samples, coupled with lack of information about normality and equality of variances of the response; ii) lack of P-value adjustment for multiple comparisons; iii) failure to account for interactions between treatment and follow-up time; and iv) no information about the number of teeth examined per patient and the consequent lack of cluster-specific approach in data analysis. Owing to these concerns, statistical methodology was judged as inappropriate in 77.1% of the 35 studies that used parametric methods. Additional studies with appropriate statistical analysis are required to obtain appropriate assessment of the efficacy of desensitizing agents.
The aim of this study was to examine the effects of tray design and impression material on impression pressure in a clinical simulation model of an edentulous mandible. Two types of polyvinylsiloxane elastomer, one type of polyether elastomer, and one type of alginate were used. The three tray types had no relief, 0.36 mm of relief, or 1.4 mm of relief, with or without escape holes. Impression pressure was measured at the median alveolar crest, the bilateral alveolar crests corresponding to molars, and the bilateral buccal shelves. Impression pressure significantly differed in relation to tray design and sensor position. In trays without escape holes, impression pressure was highest at the median alveolar crest and lowest at the buccal shelves, for all impression materials. However, impression material had no significant effects on impression pressure. Our results suggest that bite-pressure load on alveolar crests can be alleviated by making an impression with a tray that has relief and escape holes, while applying pressure to buccal shelves and almost no pressure to alveolar crests.