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To evaluate the mechanisms underlying orofacial motor dysfunction associated with trigeminal nerve injury, we studied the astroglial cell activation following chronic constriction injury (CCI) of the infraorbital nerve (ION) immunohistochemically, nocifensive behavior in ION-CCI rats, and the effect of the glutamine synthase (GS) blocker methionine sulfoximine (MSO) on the jaw-opening reflex (JOR), and also studied whether glutamate-glutamine shuttle mechanism is involved in orofacial motor dysfunction. GFAP-immunoreactive (IR) cells were observed in the trigeminal motor nucleus (motV) 3 and 14 days after ION-CCI, and the nocifensive behavior and JOR amplitude were also strongly enhanced at these times. The number of GS- and GFAP-IR cells was also significantly higher in ION-CCI rats on day 7. The amplitude and duration of the JOR were strongly suppressed after MSO microinjection (m.i.) into the motV compared with that before MSO administration in ION-CCI rats. After MSO administration, the JOR amplitude was strongly suppressed, and the duration of the JOR was shortened. Forty minutes after m.i. of glutamine, the JOR amplitude was gradually returned to the control level and the strongest attenuation of the suppressive effect of MSO was observed at 180 min after glutamine m.i. In addition, glutamine also attenuated the MSO effect on the JOR duration, and the JOR duration was extended and returned to the control level thereafter. The present findings suggest that astroglial glutamate-glutamine shuttle in the motV is involved in the modulation of excitability of the trigeminal motoneurons affecting the enhancement of various jaw reflexes associated with trigeminal nerve injury.

In this study we attempted to clarify the mechanism of the inhibitory effects of PGE 2 on DNA synthesis in Gin-1 (fibroblasts derived from healthy human gingiva) from the aspect of the cyclic AMP-dependent protein kinase signal transduction pathway. PGE 2 upregulated intracellular cyclic AMP accumulation and inhibited DNA synthesis in Gin-1 in a dose-dependent manner. When the PGE 2 -induced intracellular cyclic AMP accumulation was further enhanced by treatment with the cyclic AMP-phosphodiesterase inhibitor, IBMX, the inhibitory effect of PGE 2 on DNA synthesis was also enhanced. Furthermore, when we examined the effects of forskolin, an activator of cyclic AMP production, on intracellular cyclic AMP accumulation and DNA synthesis, similar results were obtained. However, inhibitors of cyclic AMP-dependent protein kinase (protein kinase A) such as HA1004 did not diminish the inhibitory effect of PGE 2 on DNA synthesis in Gin-l. These results suggest that in Gin-l, PGE 2 -induced cyclic AMP accumulation may not lead to the activation of protein kinase A or protein kinase A activity may not relate directly to the growth inhibitory effect of PGE 2 , and that PGE 2 does not inhibit DNA synthesis through the cyclic AMP-protein kinase A signal transduction pathway in Gin-1.

Endothelin (ET) receptors on chondrocytes were demonstrated using cultured rabbit costal chondrocytes. After crosslinking the receptors on the cells with 125 I-ET-1, two major bands of 43 kDa and 46 kDa were separated by SDS-PAGE. Scatchard analysis demonstrated two classes of ET receptors with K d values of 1 × 10 -10 M and 5 × 10 -9 M. The numbers of high- and low- affinity receptors were 1 × 10 4 and 2 × 10 5 per cell, respectively. The binding of ET-1 to chondrocytes was increased by treatment with PTH, DBcAMP, TGF-β1, IL-1β, RA and EGF. ET-1 stimulated DNA synthesis in cultured rabbit chondrocytes. ET-1 also stimulated calcium incorporation through the cell membrane of chondrocytes. These findings indicate that ET-1 has a physiological effect on chondrocytes via its receptors on the cells.

In facultative anaerobes, the anaerobic expression of respiratory genes is regulated by a transcriptional activator, FNR. Transcription in vitro of the E. coli fnr gene was repressed by its product, FNR. The transcription of the E. coli nar X gene encoding the nitrate sensor protein was likewise repressed. DNA truncation experiments for fnr and nar X genes indicated that multiple anaero-boxes in each promoter region are essential for repression by the FNR protein, but they also suggest that factor-independent upstream activation signals are operating with these promoters.

J. Neurochem. (2010) 114, 1030–1038. Abstract Nobiletin, a compound of polymethoxy flavones found in citrus fruits, possesses a wide range of pharmacological activities. Here we report the effects of nobiletin on catecholamine secretion in cultured bovine adrenal medullary cells. Nobiletin (1.0–100 μM) concentration-dependently stimulated catecholamine secretion and 45Ca2+ influx. Its stimulatory effect of nobiletin on catecholamine secretion was abolished by deprivation of extracellular Ca2+ and partially inhibited by specific inhibitors of voltage-dependent Ca2+ channels and Na+/Ca2+ exchangers. On the other hand, nobiletin suppressed catecholamine secretion and 22Na+ and 45Ca2+ influx induced by acetylcholine, an agonist of nicotinic acetylcholine receptors, in a concentration-dependent manner. It also inhibited catecholamine secretion, 22Na+ influx and/or 45Ca2+ influx induced by veratridine, an activator of voltage-dependent Na+ channels, and 56 mM K+, an activator of voltage-dependent Ca2+ channels. In Xenopus oocytes expressing α3β4 neuronal acetylcholine receptors, nobiletin directly inhibited the current evoked by acetylcholine in a concentration-dependent manner similar to that observed in catecholamine secretion. The present findings suggest that nobiletin, by itself, stimulates catecholamine secretion via activation of voltage-dependent Ca2+ channels or Na+/Ca2+ exchangers, whereas it inhibits catecholamine secretion induced by acetylcholine through the suppression of Na+ influx and Ca2+ influx in cultured bovine adrenal medullary cells.

A quantitative assay method for epidermal growth factor receptors (EGFRs) of human tumor tissues was established, based on enzyme‐labeled avidin‐biotin (LAB) interaction with anti‐human EGFR monoclonal antibody 52SIgG. A standard calibration curve for EGFR estimation in human tumor tissues was obtained with A431#8 cells cloned from A431 human epidermoid carcinoma cell line. The coefficient of variance for the standard curve was below 35% in the application to tumor tissues from nude mice implanted with human tumor cell lines. The minimum tissue amount required for the quantitative assay was around 0.1 g (wet weight). Using the LAB method, the correlation between the level of EGFR number and tumor malignancy was examined for 14 human squamous cell carcinomas (SCCs) from the oral region. Seven of the SCCs showed a more than two‐fold higher EGFR number compared to normal gingival tissues. Three highly aggressive carcinomas with poor prognosis possessed five to ten times higher levels of EGFR number than normal tissues. The elevated EGFR level in the SCCs seems to correlate to increasing tumor size and the stage of SCCs as clinically classified according to the 1987 UICC TNM system.

2H-Pyrone derivatives were synthesized through the reaction of aryl acetyl compounds with ketene dithioacetals in the presence of sodium hydroxide, and they showed very strong fluorescence in the solid state. The light-emitting region of these 2H-pyrones is 447-630 nm in the solid states.

The ultrasonic absorptions in aqueous solutions of amylamine were measured in the frequency range of 3.5–220 MHz and in the concentration range of 0.01–3.06 M. Two kinds of relaxations were observed. One was attributed to the 5A–A5 reaction of non-ionized molecules of amylamine, and the rate constants were determined from the concentration dependence of the relaxation time at various temperatures. The thermodynamic parameters were determined from the temperature dependence of the rate and equilibrium constants. The other was attributed to hydrolysis, which is a diffusion-controlled reaction. In order to clarify the relation between the stability of the aggregate and the length of the hydrophobic group, the ultrasonic absorptions in aqueous solutions of propylamine were also measured. The excess absorption due to the association-dissociation reaction was not observed; only that due to hydrolysis was observed. It was deduced from this investigation that the aggregate formed by the hydrophobic bonding exists...