No abstract

Loss of prolyl hydroxylase 2 (PHD2) activates the hypoxia-inducible factor-dependent hypoxic response, including anaerobic glycolysis, which causes large amounts of lactate to be released from cells into the circulation. We found that Phd2-null mouse embryonic fibroblasts (MEFs) produced more lactate than wild-type MEFs, as expected, whereas systemic inactivation of PHD2 in mice did not cause hyperlacticacidemia. This unexpected observation led us to hypothesize that the hypoxic response activated in the liver enhances the Cori cycle, a lactate-glucose carbon recycling system between muscle and liver, and thereby decreases circulating lactate. Consistent with this hypothesis, blood lactate levels measured after a treadmill or lactate tolerance test were significantly lower in Phd2-liver-specific knockout (Phd2-LKO) mice than in control mice. An in vivo 13 C-labeled lactate incorporation assay revealed that the livers of Phd2-LKO mice produce significantly more glucose derived from 13 C-labeled lactate than control mice, suggesting that blockade of PHD2 in the liver ameliorates lactic acidosis by activating gluconeogenesis from lactate. Phd2-LKO mice were resistant to lactic acidosis induced by injection of a lethal dose of lactate, displaying a significant elongation of survival. Moreover, oral administration of a PHD inhibitor improved survival in an endotoxin shock mice model. These data suggest that PHD2 is a potentially novel drug target for the treatment of lactic acidosis, which is a serious and often fatal complication observed in some critically ill patients.hypoxic response | PHD inhibitor | hyperlactatemia | gluconeogenesis | sepsis

Oral fluids (OFs) contain small extracellular vesicles (sEVs or exosomes) that carry disease-associated diagnostic molecules. However, cells generate extracellular vesicles (EVs) other than sEVs, so the EV population is quite heterogeneous. Furthermore, molecules not packaged in EVs can also serve as diagnostic markers. For these reasons, developing a complete picture of particulate matter in the oral cavity is important before focusing on specific subtypes of EVs. Here, we used differential centrifugation to fractionate human OFs from healthy volunteers and patients with oral squamous cell carcinoma into 5 fractions, and we characterized the particles, nucleic acids, and proteins in each fraction. Canonical exosome markers, including CD63, CD9, CD133, and HSP70, were found in all fractions, whereas CD81 and AQP5 were enriched in the 160K fraction, with non-negligible amounts in the 2K fraction. The 2K fraction also contained its characteristic markers that included short derivatives of EGFR and E-cadherin, as well as an autophagosome marker, LC3, and large multi-layered vesicles were observed by electronic microscopy. Most of the DNA and RNA was recovered from the 0.3K and 2K fractions, with some in the 160K fraction. These results can provide guideline information for development of purpose-designed OF-based diagnostic systems.

Extracellular ATP, an essential pain mediator, is received by cell-surface ionotropic P2X and/or metabotropic P2Y receptors. Although the contribution of P2X₃ and/or P2X(2/3) receptors toward the pain mechanism is well described in trigeminal ganglion neurons, the expression of other subtypes of P2X receptor remains to be clarified. We examined expression of P2X receptor mRNA and measured intracellular free Ca²⁺ concentration ([Ca²⁺]i) by the activation of these receptors by fura-2 fluorescence in primary cultured rat trigeminal ganglion neurons. Real-time reverse transcription-PCR analysis revealed mRNA expression of P2X receptor subtype P2X₁, P2X₃, and P2X₄ in trigeminal ganglion neurons. In the presence of extracellular Ca²⁺, the application of P2X receptors agonists, ATP, α,β-methylene ATP or β,γ-methylene ATP induced Ca²⁺ influx significantly. The ATP-induced increase in [Ca²⁺]i was inhibited by a series of selective antagonists for P2X₁, P2X₃, or P2X₄ receptors. These results indicate that trigeminal ganglion neurons functionally express P2X₁, P2X₃, and P2X₄ receptors and that these receptors are involved in the mediation of not only nociceptive but also neuropathic pain in the orofacial area.

This study aimed to investigate influences of lyophilization factors and gelatin concentration on pore structures of ACG sponge. ACG sponges of different freezing temperatures (−30, −80 and −196 o C), freezing times (1, 2 and 24 h), gelatin concentrations (0.6%AC+0.15%G, 0.6%AC+0.6%G and 0.6%AC+2.4%G), and with 500 μM fluvastatin were fabricated. Pore structures including porosity and pore size were analyzed by scanning electron microscopy and ImageJ. The cytotoxic effects of ACG sponges were evaluated in vitro. Freezing temperature did not affect porosity while high freezing temperature (−30 o C) increased pore size. The high gelatin concentration group (0.6%AC+2.4%G) had decreased porosity and pore size. Freezing time and 500 μM fluvastatin did not affect pore structures. The cytotoxicity and cell proliferation assays revealed that ACG sponges had no cytotoxic effects on human mesenchymal stromal cell growth and proliferation. These results indicate that ACG sponge may be a good biomaterial scaffold for bone regeneration.

We experienced two cases of inferior alveolar nerve paresthesia caused by root canal medicaments, which were successfully relieved by microscopic endodontic treatment. In the first case, the paresthesia might have been attributable to infiltration of calcium hydroxide into the mandibular canal through the root canals of the mandibular left second molar tooth. In the second case, the paresthesia might have been attributable to infiltration of paraformaldehyde through the root canals of the mandibular right second molar tooth. The paresthesia was relieved in both cases by repetitive microscopic endodontic irrigation using physiological saline solution in combination with oral vitamin B 12 and adenosine triphosphate.

Propofol is frequently used for intravenous sedation or anesthesia in ambulatory and office-based anesthesia. Although awakening is usually rapid, there are instances of delayed recovery from propofol anesthesia. It has been reported that aminophylline antagonizes the sedative effects of several anesthetic and analgesic drugs. The case reports presented here demonstrate that intravenous aminophylline effectively reversed prolonged propofol-induced sedation/anesthesia in the postoperative period. There were no side effects or delayed re-sedation after the administration of aminophylline. Our study suggests that aminophylline could be a clinically useful propofol antagonist.

Varicella-zoster virus reactivation causes zoster (shingles), a syndrome characterized by severe pain and a vesicular rash. The present report details a case of varicella-zoster virus reactivation of the maxillary and mandibular division of the right trigeminal nerve without evidence of vesicular rash (zoster sine herpete). It is difficult to identify owing to no typical clinical signs such as vesicular eruption. Zoster sine herpete of the trigeminal nerve, in particular, is rarely reported. In this case, the diagnosis was based on clinical findings and was supported by the demonstration of an immunoglobulin G antibody. Zoster sine herpete of the trigeminal nerve, in particular, should be considered in patients with severe facial pain over specific dermatomes, if they do not demonstrate appreciable findings of traumatic neuropathy, tumor or herpes zoster.