A role for the purinergic receptor P2X3 in astrocytes in the mechanism of craniofacial neuropathic pain.

The purinergic receptor P2X3, expressed in the central terminals of primary nociceptive neurons in the brainstem, plays an important role in pathological pain. However, little is known about expression of P2X3 in the brainstem astrocytes and its involvement in craniofacial pathologic pain. To address this issue, we investigated the expression of P2X3 in astrocytes in the trigeminal caudal nucleus (Vc) in a rat model of craniofacial neuropathic pain, chronic constriction injury of infraorbital nerve (CCI-ION). We found that 1) P2X3-immunoreactivity is observed in the brainstem astrocytes, preferentially in their fine processes, 2) the number of P2X3-positive fine astrocytic processes and the density of P2X3 in these processes were increased significantly in CCI-ION rats, compared to control rats, and 3) administration of MPEP, a specific mGluR5 antagonist, alleviated the mechanical allodynia and abolished the increase in density of P2X3 in fine astrocytic processes caused by CCI-ION. These findings reveal preferential expression of P2X3 in the fine astrocytic processes in the brainstem, propose a novel role of P2X3 in the fine astrocytic process in the mechanism of craniofacial neuropathic pain, and suggest that the expression of astrocytic P2X3 may be regulated by astrocytic mGluR5.

Multiple novel H5N6 highly pathogenic avian influenza viruses, South Korea, 2016.

We report the identification of novel highly pathogenic avian influenza viruses of subtype H5N6, clade 2.3.4.4, that presumably originated from China. In addition, reassortant strains with Eurasian lineage low pathogenic avian influenza viruses were isolated in wild birds and poultry in South Korea. The emergence of these novel H5N6 viruses and their circulation among bird populations are of great concern because of the potential for virus dissemination with intercontinental wild bird migration.

An ultrastructural evidence for the expression of transient receptor potential ankyrin 1 (TRPA1) in astrocytes in the rat trigeminal caudal nucleus.

The transient receptor potential ankyrin 1 (TRPA1) is implicated in the mechanical and cold hyperalgesia following inflammation and nerve injury. Its expression has been presumed to be confined to primary afferent terminals. Here, we show that TRPA1 is expressed in astrocytes in the superficial laminae of the rat trigeminal caudal nucleus by use of electron microscopic immunoperoxidase and immunogold labeling techniques. Immunoreactivity for TRPA1 was consistently observed in somata and process of astrocytes and was weaker than that in presumed nociceptive primary afferent terminals, but increased significantly in the fine process of astrocyte in rats with experimental inflammation of the temporomandibular joint. Thus, we provide ultrastructural evidence that TRPA1 is expressed in astrocytes in the brain stem and propose a novel pathway of its involvement in the central mechanism of inflammatory hyperalgesia.

Evaluation of workers exposed to ethylene glycol monomethyl ether and ethylene glycol monomethyl ether acetate.

OBJECTIVES: Ethylene glycol monomethyl ether (EGME) and ethylene glycol monomethyl ether acetate (EGMEA) are widely used in industries as solvents for coatings, paint and ink, but exposure data are limited because they are minor components out of mixed solvents, as well as because of inconsistency in desorption solvent use. The objective of this study was to investigate the worker exposure profile of EGME and EGMEA. METHODS: Our study investigated 27 workplaces from June to September 2008 and detected EGME and EGMEA in 20 and 13, respectively. Both personal and area sampling were conducted using a charcoal tube to collect EGME and EGMEA. Gas chromatography with a flame ionization detector was used to analyze these compounds after desorption using a mixture of methylene chloride and methanol. RESULTS: The arithmetic mean concentrations of EGME and EGMEA during periods of full work shifts were 2.59 ppm and 0.33 ppm, respectively. The exposure levels were lower than the Korean Ministry of Labor (MOL) OEL (5 ppm) but higher than the ACGIH TLV (0.1 ppm). CONCLUSIONS: In general, the working environments were poor and required much improvement, including the use of personal protective equipment. Only 50% of the workplaces had local exhaust ventilation systems in operation. The average capture velocity of the operating local exhaust ventilation systems was 0.27 m/s, which did not meet the legal requirement of 0.5 m/s. Educating workers to clearly understand the handling and use of hazardous chemicals and improving working conditions are strongly suggested.

Induction of G2/M arrest and apoptosis by water extract of Strychni Semen in human gastric carcinoma AGS cells.

The seed of Strychnos nux-vomica (Loganiaceae) has been used in traditional Oriental medicine as a folk remedy for the treatment of cancer. However, the mechanism responsible for the anticancer effects of Strychni Semen is not clearly understood. The study tested whether and how the water extract of Strychni Semen (ESS) treatment would affect the growth of AGS human gastric carcinoma cells. ESS was found to inhibit the growth of AGS cells in a concentration-dependent manner. Cell cycle analysis showed G2/M phase arrest and apoptosis in AGS cells following ESS treatment. ESS-mediated G2/M arrest was found to be associated with up-regulation of cyclin A, Cdc2, tumor suppressor p53 and cyclin dependent kinase (Cdk) inhibitor p21(WAF1/CIP1), whereas the expressions of other G2/M regulatory proteins, including cyclin B1 and Cdk2, were down-regulated compared with the control. The induction of apoptotic cell death by ESS was associated with down-regulation of anti-apoptotic Bcl-2 and up-regulation of pro-apoptotic Bax expression. Further results indicate that caspase-3, caspase-8 and caspase-9 are all activated by ESS, together with cleavage of downstream caspase-3 target proteins. Taken together, the results of this study suggest the involvement of multiple signaling pathways targeted by ESS in mediating G2/M cell cycle arrest and apoptosis in AGS cells, and warrant further investigation.

Fabrication of photonic devices directly written within glass using a femtosecond laser.

We present a novel method for three-dimensional optical splitter that have U-grooves, which are used for fiber alignment, within a fused silica glass using near-IR femtosecond laser pulses. The fiber aligned optical splitter has a low insertion loss, less than 4 dB, including an intrinsic splitting loss of 3 dB and excess loss due to the passive alignment of a single-mode fiber. The output field pattern is presented, demonstrating the splitting ratio of the optical splitter is approximately 1:1. Finally, we demonstrate the utility of the femtosecond laser writing of periodic patterns by fabricating the submicron line and dot patterns inside the silica glass, which is applicable to 3-D optical memory.