Effects of glucosamine on tooth pulpal nociceptive responses in the rat

AbstractBackground/purposed-Glucosamine hydrochloride (DGL) has a variety of biological activities and is noted as a nutritional supplement that is effective for improvement and care of various disorders, such as osteoarthritis and atherosclerosis. Although, it has been reported that DGL has a significant pain relief effect in treating osteoarthritis, little is known about its effect on dental pain. The applicability of DGL as a medicament to control pain in pulpalgia has not been reported. In this study, using an in vitro rat mandible-inferior alveolar nerve preparation (jaw-nerve preparation), the effect of DGL on nociceptive responses in the tooth pulpal nerve was examined.Materials and methodsThe effect of DGL on nociceptive responses for 20 male Wistar albino rats was evaluated using an in vitro jaw-nerve preparation. Bradykinin (BK), used as a chemical nociceptive stimulant, was applied near the exposed tooth pulp. Sixty seconds after BK application, the surface of the exposed pulp was treated with DGL solution or physiological saline (control).ResultsThe nerve firing rate was 2.06±0.21Hz (n=10) after 5 minutes of saline application, and 0.76±0.16Hz (n=10) after 5 minutes of DGL application. The DGL group showed significantly lower nerve firing rate than the control group.ConclusionBK-induced nociceptive responses were significantly suppressed by direct application of DGL. Our results suggest that DGL might have a pain relief effect in dental pain

Suppressive Effects of D-Glucosamine on the 5-HT Sensitive Nociceptive Units in the Rat Tooth Pulpal Nerve

It is well known that D-glucosamine hydrochloride (DGL) has a variety of biological activities and is regarded as a nutritional supplement effective in improving various disorders, including osteoarthritis and atherosclerosis. Although it has been reported that DGL has a significant pain relief effect in treating osteoarthritis, little is known about the characteristics of the effects of this compound on dental pain. The present study was undertaken to evaluate the applicability of DGL as a medicament to control pulpalgia. Using an in vitro rat mandible-inferior alveolar nerve preparation (jaw-nerve preparation), we evaluated the effects of DGL on 5-hydroxytryptamine (5-HT) sensitive nociceptive responses in the tooth pulpal nerve. 5-HT-induced nociceptive responses were fairly suppressed by direct application of DGL, suggesting that DGL have a pain relief effect on patients with dental pain

Suppressive Effects of D-Glucosamine on the 5-HT Sensitive Nociceptive Units in the Rat Tooth Pulpal Nerve

It is well known that D-glucosamine hydrochloride (DGL) has a variety of biological activities and is regarded as a nutritional supplement effective in improving various disorders, including osteoarthritis and atherosclerosis. Although it has been reported that DGL has a significant pain relief effect in treating osteoarthritis, little is known about the characteristics of the effects of this compound on dental pain. The present study was undertaken to evaluate the applicability of DGL as a medicament to control pulpalgia. Using an in vitro rat mandible-inferior alveolar nerve preparation (jaw-nerve preparation), we evaluated the effects of DGL on 5-hydroxytryptamine (5-HT) sensitive nociceptive responses in the tooth pulpal nerve. 5-HT-induced nociceptive responses were fairly suppressed by direct application of DGL, suggesting that DGL have a pain relief effect on patients with dental pain

ラット前帯状回侵害受容性ニューロンのストレスによる応答変化

In the limbic system, the anterior cingulate cortex (ACCX) is one of the key areas involved in the close association between pain and emotion. However, neuronal changes in ACCX nociceptive responses after stress conditioning have not yet been quantitatively investigated. We investigated the modulation of nociceptive responses in the ACCX neurons following restraint stress in rats. The present study demonstrated that stress-conditioning enhanced excitatory nociceptive responses in the ACCX following tail stimuli in the mid-term (7 days). Short-term (3 days) and long-term (21 days) of stress conditioning did not affect these responses significantly. Nociceptive responses evoked by other sites of the body (nose, back and four paws) stimulation were not changed by stress-conditioning, indicating that neural information from the tail is important for emotional system modulation. It is suggested that the emotional/affective part of the pain sensation is strongly modified by stress through neuroplasticity in the ACCX.長崎大学学位論文 学位記番号:博(医歯薬)甲第640号 学位授与年月日:平成25年12月4日Author: Hiromi Yamashita, Jorge L. Zeredo, Kei Kaida, Mari Kimoto, Izumi Asahina, Kazuo TodaCitation: Journal of Integrative Neuroscience, 12(2), pp.235-246; 2013Nagasaki University (長崎大学)課程博

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

The Constrained Maximal Expression Level Owing to Haploidy Shapes Gene Content on the Mammalian X Chromosome.

X chromosomes are unusual in many regards, not least of which is their nonrandom gene content. The causes of this bias are commonly discussed in the context of sexual antagonism and the avoidance of activity in the male germline. Here, we examine the notion that, at least in some taxa, functionally biased gene content may more profoundly be shaped by limits imposed on gene expression owing to haploid expression of the X chromosome. Notably, if the X, as in primates, is transcribed at rates comparable to the ancestral rate (per promoter) prior to the X chromosome formation, then the X is not a tolerable environment for genes with very high maximal net levels of expression, owing to transcriptional traffic jams. We test this hypothesis using The Encyclopedia of DNA Elements (ENCODE) and data from the Functional Annotation of the Mammalian Genome (FANTOM5) project. As predicted, the maximal expression of human X-linked genes is much lower than that of genes on autosomes: on average, maximal expression is three times lower on the X chromosome than on autosomes. Similarly, autosome-to-X retroposition events are associated with lower maximal expression of retrogenes on the X than seen for X-to-autosome retrogenes on autosomes. Also as expected, X-linked genes have a lesser degree of increase in gene expression than autosomal ones (compared to the human/Chimpanzee common ancestor) if highly expressed, but not if lowly expressed. The traffic jam model also explains the known lower breadth of expression for genes on the X (and the Z of birds), as genes with broad expression are, on average, those with high maximal expression. As then further predicted, highly expressed tissue-specific genes are also rare on the X and broadly expressed genes on the X tend to be lowly expressed, both indicating that the trend is shaped by the maximal expression level not the breadth of expression per se. Importantly, a limit to the maximal expression level explains biased tissue of expression profiles of X-linked genes. Tissues whose tissue-specific genes are very highly expressed (e.g., secretory tissues, tissues abundant in structural proteins) are also tissues in which gene expression is relatively rare on the X chromosome. These trends cannot be fully accounted for in terms of alternative models of biased expression. In conclusion, the notion that it is hard for genes on the Therian X to be highly expressed, owing to transcriptional traffic jams, provides a simple yet robustly supported rationale of many peculiar features of X's gene content, gene expression, and evolution

CCNE1 and E2F1 Partially Suppress G1 Phase Arrest Caused by Spliceostatin A Treatment

The potent splicing inhibitor spliceostatin A (SSA) inhibits cell cycle progression at the G1 and G2/M phases. We previously reported that upregulation of the p27 cyclin-dependent kinase inhibitor encoded by CDKN1B and its C-terminal truncated form, namely p27*, which is translated from CDKN1B pre-mRNA, is one of the causes of G1 phase arrest caused by SSA treatment. However, the detailed molecular mechanism underlying G1 phase arrest caused by SSA treatment remains to be elucidated. In this study, we found that SSA treatment caused the downregulation of cell cycle regulators, including CCNE1, CCNE2, and E2F1, at both the mRNA and protein levels. We also found that transcription elongation of the genes was deficient in SSA-treated cells. The overexpression of CCNE1 and E2F1 in combination with CDKN1B knockout partially suppressed G1 phase arrest caused by SSA treatment. These results suggest that the downregulation of CCNE1 and E2F1 contribute to the G1 phase arrest induced by SSA treatment, although they do not exclude the involvement of other factors in SSA-induced G1 phase arrest

Effects of two methyl methacrylate-tributylborane-based luting agents with a silane-phosphate primer on bonding of four different CAD/CAM resin composite materials

Purpose: This study compared the bond strengths of four adhesive systems and four different resin composite block materials: Gradia Block (GR), Shofu Block HC (SH), Estelite Block (ES), and KZR-CAD HR2 (KZ).Methods: A primer (PZ-AB) containing a silane (γ-MPTS) with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) was applied to ground surfaces of the resin composite block specimens, and the specimens were then bonded to stainless-steel rods using two methyl methacrylatetributylborane (MMA-TBB)-based luting agents (SB and MT), designated as the PZ-AB/SB and PZ-AB/MT adhesive systems, respectively. The SB resin contained 4-methacryloyloxyethyl trimellitate anhydride (4-META), whereas the MT resin did not. The SB resin without primer (No primer/ SB) and a dual-curing composite-type adhesive system (UPA/RelyX) were used as controls. The 24-h tensile bond strengths were determined and analyzed using the Tukey-Kramer HSD test (α = 0.05, n = 8).Results: The highest bond strengths were obtained for the GR/PZ-AB/MT, GR/PZ-AB/SB, KZ/PZ-AB/MT, ES/PZ-AB/SB, and KZ/No primer/SB groups, whereas the KZ/UPA/RelyX, ES/UPA/RelyX, SH/UPA/RelyX, and SH/No primer/SB groups exhibited the lowest bond strengths.Conclusion: For each resin composite block material primed with γ-MPTS and MDP, the MMA-TBB-based luting agents, irrespective of the presence of 4-META, provided higher bond strengths than the dual-curing composite-type adhesive system

Effect of tetrabutylammonium dihydrogen trifluoride treatment on durability of resin–titanium bond strengths

Abstract: This study investigated the effect of titanium surface treatment with tetrabutylammonium dihydrogen trifluoride (TDTF) on the bond between the titanium and resins for dental applications. Commercially pure titanium (cpTi) specimens were air-abraded with alumina particles, surface-treated with an etchant containing TDTF (Monobond Etch & Prime; ETCH) for 10 s (ETCH10) or 30 s (ETCH30), rinsed with water, treated with a phosphoric monomer-based primer, and bonded to an indirect resin composite. Non-ETCH-treated specimens (no-ETCH) were prepared as a control. The shear bond strengths were determined before and after 100,000 thermocycles, and the means and standard deviations for eight specimens were calculated and statistically analyzed using a non-parametric Steel–Dwass test (α = 0.05). The ETCH10 and ETCH30 specimens exhibited the highest bond strengths, which were maintained for 100,000 thermocycles, while significantly lower values were obtained for no-ETCH specimens. In conclusion, the surface treatment with a TDTF-containing etchant considerably improved the durability of the resin–cpTi bond strength. Appropriate surface treatment of cpTi should be selected for achieving longer-lasting treatments and better clinical solutions for patients. Keywords: Adhesion, Metal, Surface modificatio