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H C Ferreira

Publications and source records attributed to H C Ferreira.

8 recordsLinked to original sources

Endothelium-dependent vasodilation induced by Hancornia speciosa in rat superior mesenteric artery.

The vasodilator effect of the ethanolic extract of leaves from Hancornia speciosa Gomes (HSE) was evaluated in superior mesenteric artery rings. HSE produced a concentration-dependent vasodilation (IC50 = 10.8 +/- 4.0 microg/mL) in arterial rings pre-contracted with phenylephrine, which was completely abolished in endothelium-denuded vessels. Endothelium-dependent vasodilation induced by HSE was strongly reduced by L-NAME (100 microM), a nitric oxide (NO) synthase inhibitor, but neither by atropine, a muscarinic receptor antagonist (1 microM), nor by indomethacin (10 microM), a cyclooxygenase inhibitor. In rings pre-contracted with 80 mM KCl, the vasodilator effect of HSE was shifted to the right and was completely abolished in the presence of L-NAME (100 microM). Similar effects were obtained in mesenteric rings pre-contracted with phenylephrine in the presence of KCl 25 mM alone or in addition to 100 microM L-NAME. In addition, BaCl2 (1 mM) dramatically reduced the vasodilation induced by HSE. Together, these findings led us to conclude that HSE induces an endothelium-dependent vasodilation in rat mesenteric artery, by a mechanism dependent on NO, on the activation of potassium channels and endothelium-derived hyperpolarizing factor release. Rutin, identified as a major peak in the HPLC fingerprint obtained for HSE, might contribute for the observed vasodilator effect, since it was able to induce an endothelium-dependent vasodilation in rat superior mesenteric arteries.

Animals↗

Therapeutic potential of a new phosphodiesterase inhibitor in acute lung injury.

The effects of LASSBio596, a phosphodiesterase type-4 and -5 inhibitor, were tested in Escherichia coli lipopolysaccharide (LPS)-induced acute lung injury. Twenty-four BALB/c mice were randomly divided into four groups. In the control group, saline (0.05 mL) was injected intratracheally (i.t.). The LPS group received LPS (10 microg i.t., 0.05 mL). In the LASSBio596 groups, LASSBio596 (10 mg x kg(-1), 0.2 mL) was injected intraperitoneally 1 h before or 6 h after LPS administration. After 24 h, in vivo (lung resistive and viscoelastic pressures, and static and dynamic elastances) and in vitro (tissue resistance, elastance and hysteresivity) pulmonary mechanics, lung morphometry and collagenous fibre content were computed. Neutrophils and tumour necrosis factor (TNF)-alpha levels were evaluated in the bronchoalveolar lavage fluid. LASSBio596 prevented the changes in lung mechanics, and inhibited neutrophilic recruitment, TNF-alpha release, bronchoconstriction, alveolar collapse and the increment of collagen fibre content induced by LPS, independently of the moment of injection. In conclusion, LASSBio596 modulated the lung inflammatory process and had the potential to block fibroproliferation. Thus, agents that inhibit phosphodiesterase 4 and 5 simultaneously may be a useful adjunct therapy for acute lung injury.

Analysis of Variance↗

[Fibrinogen estimation. A simplified gravimetric method (author's transl)].

UNLABELLED: A simplified gravimetric method is proposed for fibrinogen estimation in plasma. Technic: 0.5 ml plasma (citrated) are diluted to up 5 ml with saline. A stick, 5 to 6 cm long, made of a glass capillary tube, or, aluminium foil, with ends bended as a hock, are weighted up to 0.001 g. Introduce one stick previously weighted in diluted plasma. Place two drops of thrombin (10 U/ml), and mix. In seconds, all fibrinogen is transformed in fibrin, deposited around the stick. Remove the stick with the fibrin, and press gently with the fingers, expelling the liquid in excess. Hang the stick with the fibrin, on the rim of a dry centrifuge tube. Centrifuge at 3.000 rpm for 10 minutes (dry centrifugation). Centrifugal forces acting on the fibrin clot expell all liquid particles. Fibrin consist of a very thin layer adhered on the stick. The weight difference (initial and final), represents the solid fibrin. CALCULATION: difference of weight added by 0.1 of the difference (anticoagulant dilution) x 200 to convert in dl. The method is highly reproductible, and takes about 20 minutes to be completed.

Fibrinogen↗