Nitric oxide (NO) scavenging and NO protecting effects of quercetin and their biological significance in vascular smooth muscle.

The flavonoid quercetin reduces blood pressure and endothelial dysfunction in animal models of hypertension. However, the results concerning the relationship between quercetin and NO present a complex picture. We have analyzed the mechanisms involved in the NO scavenging effects of quercetin and its repercussion on NO bioactivity in vascular smooth muscle.

Effects of the flavonoid quercetin and its methylated metabolite isorhamnetin in isolated arteries from spontaneously hypertensive rats.

Chronic oral quercetin exerts antihypertensive effects in spontaneously hypertensive rats (SHR). In the present study, the vasodilator effects of the flavonoid quercetin and its main metabolite isorhamnetin were analysed in isolated thoracic aorta, iliac artery and on the isolated perfused mesenteric resistance vascular bed from SHR and normotensive Wistar Kyoto rats (WKY). In noradrenaline-precontracted vessels from SHR there was an inverse correlation between the relaxant potency (pIC50) of quercetin (4.

Pressure-induced three-dimensional ferromagnetic correlations in the giant magnetocaloric compound Gd5Ge4.

The giant magnetocaloric compound Gd5Ge4 is the only member of the Gd5(SixGe1-x)4 family where three-dimensional exchange interactions between two-dimensional correlated layers of the crystallographic structure are so weak that spontaneous ferromagnetism does not set in at any temperature. In this Letter we explore the possibility to reach the ferromagnetic state by application of hydrostatic pressure. Linear thermal expansion and magnetic measurements under pressure reveal that the reduction of the unit cell volume induces a spatially phase-segregated ground state below 10 kbar.

A novel developmental mechanism in Dictyostelium revealed in a screen for communication mutants.

We performed a screen for signaling genes by selecting mutant strains of Dictyostelium that fail to develop spores in a pure population but sporulate well in chimerae with wild type cells. We found 9 strains whose sporulation was induced up to 10 million-fold in chimerae. Most strains were also able to sporulate in chimerae with each other, but 2 pairs failed to do so, suggesting that the genes in each pair participate in the production of 1 signal.

An unusual case of uveitis-glaucoma-hyphema syndrome.

Purpose: To report a case of uveitis-glaucoma-hyphema (UGH) syndrome in which anterior chamber paracentesis led to the diagnosis of sickle cell trait.

Design: Observational case report.

Methods: A 43-year-old Cuban pseudophakic male was seen multiple times over a 3-year period complaining of floaters and blurry vision in his left eye.

Metastatic breast cancer to 4 eyelids: a clinicopathologic report.

A 47-year-old woman presented complaining of progressive, painless swelling of all 4 eyelids for 6 weeks. Her medical history was significant for breast cancer 14 months prior. Examination results showed a diffuse, firm thickening of all 4 eyelids with mild erythema of the overlying skin.

Orbital presentation of posttransplantation lymphoproliferative disorder: a small case series.

Objective: To describe a small series of patients with orbital presentation of posttransplantation lymphoproliferative disorder (PTLD).

Design: Retrospective, interventional case series.

Participants: Three patients with orbital presentation of histologically diagnosed PTLD.

Evidence that the hypotensive effect of WAY 100635, a 5-HT1A receptor antagonist, is related to vascular alpha 1-adrenoceptor blockade in the adult rat.

1. The effect of WAY100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide trihydrochloride), a 5-HT1A receptor antagonist, on cardiovascular function was studied. 2.

Evidence that NAN-190-induced hypotension involves vascular alpha1-adrenoceptor antagonism in the rat.

The effect of NAN-190 (1-(2-methoxyphenyl)-4-[4-(2-phthalimido]-butyl] piperazine), described as a mixed 5-HT(1A) receptor agonist/antagonist, on cardiovascular function was studied. The i.v.

Prolonged premonitory optic disc signs in anterior ischemic optic neuropathy.

A patient displayed a pink mass on the right optic disc and normal visual function that was diagnosed as a capillary hemangioma. Seven months later, he developed typical features of nonarteritic anterior ischemic optic neuropathy (NAION) in that eye. Such a long latency between "preeruptive" and "eruptive" disc edema has not been well documented in NAION.

Intraocular caterpillar setae without subsequent vitritis or iridocyclitis.

Purpose: To report a case of caterpillar setae embedded in the corneal stroma and inferotemporal retina with minimal inflammation.

Design: Observational case report.

Methods: A 4-year-old boy developed a red eye after playing with a caterpillar.

Endothelium-independent vasodilator effects of the flavonoid quercetin and its methylated metabolites in rat conductance and resistance arteries.

The flavonoid quercetin is metabolized into isorhamnetin, tamarixetin, and kaempferol, the vascular effects of which are unknown. In the present study, the effects of quercetin and its metabolites were analyzed on isometric tension in isolated rat thoracic and abdominal aorta, in isolated intact and beta-escin-permeabilized iliac arteries, and on perfusion pressure in the isolated mesenteric resistance vascular bed. In noradrenaline-precontracted vessels, the four flavonoids produced a vasodilator effect, which was inversely correlated with the diameter of the vessel studied; i.

Cardiovascular effects of isorhamnetin and quercetin in isolated rat and porcine vascular smooth muscle and isolated rat atria.

Isorhamnetin and quercetin produced endothelium-independent vasodilator effects in rat aorta, rat mesenteric arteries, rat portal vein and porcine coronary arteries. The effects of the two flavonoids were similar in arteries stimulated by noradrenaline, KCl, U46619 or phorbol esters but the two flavonoids were more potent in the coronary arteries than in the aorta. At high concentrations, they also induced a positive inotropic effect in isolated rat atria.

A transcriptional profile of multicellular development in Dictyostelium discoideum.

A distinct feature of development in the simple eukaryote Dictyostelium discoideum is an aggregative transition from a unicellular to a multicellular phase. Using genome-wide transcriptional analysis we show that this transition is accompanied by a dramatic change in the expression of more than 25% of the genes in the genome. We also show that the transcription patterns of these genes are not sensitive to the strain or the nutritional history, indicating that Dictyostelium development is a robust physiological process that is accompanied by stereotypical transcriptional events.

Reconstruction with rectus abdominis myocutaneous free flap after orbital exenteration in children.

Objective: To present a 1-stage technique for orbital reconstruction after exenteration with the use of myocutaneous rectus abdominis free flap in children.

Surgical Technique: After orbital exenteration, a myocutaneous rectus abdominis free flap with long vascular pedicle is harvested from the abdomen. The flap is transferred to the orbit and the vascular pedicle is passed through an opening made in the lateral orbital wall, where it is anastomosed to superficial temporal vessels.

Propafenone modulates potassium channel activities of vascular smooth muscle from rat portal veins.

We have studied the effects of the class Ic antiarrhythmic propafenone on K+ currents in freshly isolated smooth muscle cells from rat portal veins and on the spontaneous contractions in whole tissues. Under Ca2+-free conditions, when cells were clamped at -80 mV (whole-cell configuration) depolarizing steps from -80 to +50 mV induced a family of K+ currents (I(Ktotal)) that mainly comprised the delayed rectifier current [I(K(V))], whereas when held at -10 mV only small-amplitude, noninactivating, currents (I(NI)) were recorded. Propafenone (10 microM) markedly inhibited I(Ktotal), but at potentials positive to +30 mV it also induced a noisy outwardly rectifying current [I(BK(Ca))] that was abolished by iberiotoxin (0.

The hypotensive effect of BMY 7378 is antagonized by a silent 5-HT(1A) receptor antagonist: comparison with 8-hydroxy-dipropylamino tetralin.

Background: Stimulation of central 5-HT(1A) receptors produces bradycardia and diminishes blood pressure in conscious or anesthetized rats. Our objective was to investigate the effects on blood pressure and heart rate of the partial 5-HT(1A) receptor agonist and selective alpha1D-adrenoceptor antagonist BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-8-azaspiro [4.5] decane-7,9 dione hydrochloride) compared to the full 5-HT(1A) receptor agonist 8-OH-DPAT (8-hydroxy-dipropylamino tetralin) in adult anesthetized rats.

Pulmonary artery vasoconstriction but not [Ca2+]i signal stimulated by thromboxane A2 is partially resistant to NO.

To characterize the thromboxane A2 (TXA2) -induced resistance to the vasodilator effects of the nitric oxide (NO)/cGMP pathway in pulmonary arteries, we have studied the effects of the NO donor sodium nitroprusside on intracellular calcium concentration ([Ca2+]i) and contractile force recorded simultaneously in isolated piglet pulmonary arteries loaded with fura-2 and contracted with norepinephrine or the TXA2 mimetic U46619 and by activation of protein kinase C (PKC) with phorbol 12-myristate 13-acetate. In the TXA2 mimetic- and phorbol 12-myristate 13-acetate plus norepinephrine-stimulated arteries, nitroprusside exhibited lower vasodilator efficacy (and lower potency in the TXA2 mimetic-stimulated arteries) but similar reductions in [Ca2+]i compared with arteries activated by norepinephrine. The nonselective serine/threonine kinase inhibitor staurosporine, but not the selective inhibitor of PKC bisindolylmaleimide, potentiated the relaxation of nitroprusside in the TXA2 mimetic-stimulated arteries.

The influence of chloroethylclonidine-induced contraction in isolated arteries of Wistar Kyoto rats: alpha1D- and alpha1A-adrenoceptors, protein kinase C, and calcium influx.

Background: It has recently been reported that chloroethylclonidine (CEC) elicited contraction in tail arteries (alpha(1A)-adrenoceptors) and aorta (alpha(1D)-adrenoceptors) from normotensive and spontaneously hypertensive rats (SHR). This study investigated the relationship between CEC-induced contraction and the role of protein kinase C (PKC) and extracellular Ca(++) influx in tail arteries and aorta from Wistar Kyoto rats (WKY).

Methods: Time-course of CEC-induced contraction in endothelium-denuded arteries from Wistar, WKY, and SHR rats was evaluated.

Nitric oxide- and nitric oxide donors-induced relaxation and its modulation by oxidative stress in piglet pulmonary arteries.

Inhaled nitric oxide (iNO) is widely used in the treatment of pulmonary hypertension while inhaled NO donors have been suggested as an alternative therapy. The differential susceptibility to inactivation by oxidative stress and oxyhaemoglobin of NO and two NO donors, sodium nitroprusside (SNP) and S-nitroso-N-acetyl-penicillamine (SNAP) were analysed in isolated endothelium-denuded pulmonary arteries from 2-week-old piglets stimulated with U46619. NO, SNAP and SNP relaxed the arteries (pIC(30)=7.

The alpha-adrenoceptor antagonist, zolertine, inhibits alpha1D- and alpha1A-adrenoceptor-mediated vasoconstriction in vitro.

1. The antagonist effect of zolertine (4-phenyl-1-[2-(5-tetrazolyl)ethyl]piperazine trihydrochloride), on vascular contraction elicited by noradrenaline in aorta, carotid (alpha1D-adrenoceptors), mesenteric (alpha1A/D-adrenoceptors) and caudal arteries (alpha1A-adrenoceptors) from Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats and rabbit aorta (alpha1B-adrenoceptors), was investigated in endothelium-denuded arterial rings. 2.

Mechanisms involved in SNP-induced relaxation and [Ca+]i reduction in piglet pulmonary and systemic arteries.

1. We have compared the mechanisms involved in sodium nitroprusside (SNP)-induced relaxation and [Ca2+]i reduction in isolated piglet pulmonary (PA) and mesenteric (MA) arteries. 2.

Volume and anisotropic spontaneous striction in layered manganites: role of charge localization and magnetic interactions.

Thermal expansion measurements have been performed on single crystals of R2-2xSr1+2xMn2O7 (R=Pr, Nd, and Dy) over a wide temperature range (4-900 K). Our analysis allows us to give a general explanation for the large lattice anomalies observed in the layered manganites. Localization of the carriers gives rise to volume and anisotropic anomalies in the paramagnetic regime.

NMR probe of phase segregation in electron doped mixed valence manganites.

A 55Mn and 139La NMR study of La0.35Ca0.65MnO3 is reported.