Human urocortin 2, a corticotropin-releasing factor (CRF)2 agonist, and ovine CRF, a CRF1 agonist, differentially alter feeding and motor activity

Two corticotropin-releasing factor (CRF) receptor families have been identified (CRF1 and CRF2). Whereas anxiogenic-like roles for the CRF1 receptor have been identified, behavioral functions of the CRF2 receptor remain obscure. Urocortin 2 (Ucn 2), a CRF-related peptide that selectively binds CRF2 receptors, was recently identified and recognized for its central anorectic properties. The present study tested the hypothesis that the anorexigenic mode of action of Ucn 2 differed from that of ovine CRF (oCRF), a preferential CRF1 receptor agonist. The behavioral effects of intracerebroventricular administration of Ucn 2 were compared with those of oCRF in nondeprived male Wistar rats (n=102). Ucn 2 reduced 6-h food and water intake at doses that did not induce visceral illness (0.1, 1, and 10 microg), as indicated by kaolin intake. Ucn 2 retained its potent anorectic activity in rats receiving a highly palatable cafeteria diet, preferentially reducing intake of carbohydrate (CHO)-rich items while sparing intake of mixed-fat/CHO items. In contrast to Ucn 2, oCRF (10 microg) suppressed 6-h intake of cafeteria diet-fed rats without regard to macronutrient composition. Rather, oCRF most potently suppressed intake of preferred food items. Whereas oCRF had short-onset motor-activating effects, Ucn 2 had nondose-dependent, delayed-onset motor-suppressing effects. Thus, central infusion of a CRF2 receptor agonist suppressed intake of both bland and palatable diets without inducing behavioral arousal or malaise, and the profile of anorexigenic effects qualitatively differed from those of a CRF1 receptor agonist. The results suggest the existence of distinct forms of CRF1- and CRF2-mediated anorexia.     

Antiviral effect of sulfated sialyl lipid against a clinical strain of adenovirus

PURPOSE: Currently, there is no antiviral drug for adenovirus(AdV). We have reported that sulfated sialyl lipid(NMSO) 3, a NMSO, has an antiviral effect against AdV prototype strains. We evaluated the antiviral inhibitory effect and the mechanism of NMSO 3 against AdV strains from patients with conjunctivitis in vitro. METHODS: Viruses used for the experiment were clinically isolated AdV type 3(AdV 3), AdV type 4(AdV 4), type 8(ADV 8), AdV type 19(AdV 19), and type 37(AdV 37). We examined three antiviral agents, i.e., NMSO 3, cidofovir(HPMPC), and zalcitabine(ddC). 50% effective concentration(EC50), 50% cytotoxic concentration(CC50), and selectivity index(SI) of compounds were determined for AdV infection in HEp-2 cells using 3-(4,5-dimetyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods. We also evaluated the anti-AdV activity of NMSO 3 when it was added during the stage of virus adsorption. RESULTS: NMSO 3, HPMPC, and ddC showed an inhibitory effect against all five AdV clinical strains. The EC50 values of NMSO3 were lower than those of HPMPC and ddC. NMSO 3 exhibited minimal cytotoxicity. NMSO 3 inhibited AdV infection only when it was added during the stage of virus adsorption. CONCLUSIONS: NMSO 3 inhibited the replication of all clinical AdV serotypes tested. NMSO 3 was the most potent and selective anti-AdV compound. The mechanism of anti-AdV activity by NMSO 3 was inhibition of viral adsorption to cells.     

The role of N-methyl-D-aspartate (NMDA) receptors in pain: a review

There is accumulating evidence to implicate the importance of N-methyl-D-aspartate (NMDA) receptors to the induction and maintenance of central sensitization during pain states. However, NMDA receptors may also mediate peripheral sensitization and visceral pain. NMDA receptors are composed of NR1, NR2 (A, B, C, and D), and NR3 (A and B) subunits, which determine the functional properties of native NMDA receptors. Among NMDA receptor subtypes, the NR2B subunit-containing receptors appear particularly important for nociception, thus leading to the possibility that NR2B-selective antagonists may be useful in the treatment of chronic pain.     

Single-stage procedure for multiple dissected aortic aneurysms with coagulopathy in an elderly patient

An 86-year-old man was admitted for abdominal pain. Dissected descending thoracic aortic aneurysm and infrarenal abdominal aortic aneurysm were observed under computed tomographic (CT) scan. Hematologic studies revealed low platelet count and an increase in fibrin degradation products (FDP), and disseminated intravascular coagulation( DIC) associated with dissecting aortic aneurysm was highly suspected. Platelet transfusion was performed and gabexate mesilate was administered, however, no improvement of DIC could be obtained. An increase in aortic diameter was observed under CT scan and surgery was performed. The infrarenal aneurysm was replaced with a bifurcated prosthetic graft under open repair. Simultaneously, an endovascular stent-graft was delivered from the left limb of the abdominal graft and implanted into the descending thoracic aorta. The postoperative recovery was uneventful but platelet count did not improve in this case.     

Comparison of the inhibitory effects of docosahexaenoic acid (DHA) on U46619- and phenylephrine-induced contractions in guinea-pig aorta

Inhibitory effects of docosahexaenoic acid (DHA) on the muscle contractions induced by U46619, a thromboxane A2 (TXA2) mimetic, and phenylephrine were compared in guinea-pig aorta. In de-endothelialized guinea-pig aortic ring preparations, DHA at 10 microM strongly inhibited a sustained contraction produced by U46619 (3-100 nM) whereas it did not exhibit an appreciable effect on phenylephrine (3-10 microM)-induced contraction. The present findings indicate that DHA inhibits more selectively TXA2 receptor (TP receptor)-mediated vascular contraction than alpha-adrenoceptor-mediated response. Selective inhibition by DHA of TP receptor-mediated contraction of blood vessels seems underlie in part the mechanisms by which this polyunsaturated fatty acid exerts its circulatory-protective effects.     

Stabilization Mechanism of Roxithromycin Tablets Under Gastric pH Conditions

Macrolide antibiotics are widely used at clinical sites. Clarithromycin (CAM), a 14-membered macrolide antibiotic, was reported to gelate under acidic conditions. Gelation allows oral administration of acid-sensitive CAM without enteric coating by hindering the penetration of gastric fluid into CAM tablets. However, it is unknown whether this phenomenon occurs in other macrolide antibiotics. In this study, we examined the gelation ability of 3 widely used macrolide antibiotics, roxithromycin (RXM), erythromycin A, and azithromycin. The results indicated that not only CAM but also RXM gelated under acidic conditions. Erythromycin A and azithromycin did not gelate under the same conditions. Gelation of RXM delayed the disintegration of the tablet and release of RXM from the tablet. Disintegration and release were also delayed in commercial RXM tablets containing disintegrants. This study showed that 2 of the 4 macrolides gelated, which affects tablet disintegration and dissolution and suggests that this phenomenon might also occur in other macrolides.     

Effect of cilnidipine on L- and T-type calcium currents in guinea pig ventricle and action potential in rabbit sinoatrial node

Cilnidipine, a dihydropyridine Ca(2+) channel antagonist, is known to have inhibitory effects on both L- and N-type Ca(2+) currents. In the present study, we examined the effect of cilnidipine on myocardial L- and T-type Ca(2+) currents and sinoatrial node action potential configuration. In voltage clamped guinea pig ventricular myocytes, cilnidipine concentration-dependently decreased L- and T-type Ca(2+) currents. In rabbit sinoatrial node tissue, cilnidipine increased cycle length through reduction of phase 4 depolarization slope. In conclusion, cilnidipine has inhibitory effects on T-type Ca(2+) current, which may contribute to its negative chronotropic potency.     

Detection of Agonistic Activities Against Five Human Nuclear Receptors in River Environments of Japan Using a Yeast Two-Hybrid Assay

A total of 16 water samples from four rivers in Japan were examined for their agonistic activities against five human nuclear receptors (estrogen receptor [ER] α, thyroid hormone receptor α, retinoic acid receptor [RAR] α, retinoid X receptor α, and vitamin D receptor) by using a yeast two-hybrid assay. The results suggest that the river environment is contaminated with endocrine disrupting chemicals (EDCs) that can interact with a variety of nuclear receptors and that contamination with those that have RAR agonistic activity may be more serious than contamination with well-known EDCs that act as ER agonists.