Marco Antônio de Oliveira

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Haemozoin (Hz) is a haem aggregate produced in some blood-feeding organisms. There is a general belief that Hz formation would be a protective mechanism against haem toxicity. Here we show that when aggregated into Hz, haem is less deleterious than its free form. When haem was added to phosphatidylcholine (PC) liposomes, there was an intense stimulation of(More)
Endothelial cells modulate vascular tone by releasing endothelium-derived relaxing and contracting factors. An imbalance of these factors in hypertension could contribute to increased peripheral vascular resistance. To investigate whether an endothelium-derived contracting factor is involved in the altered reactivity of microvessels of two-kidney, one-clip(More)
INTRODUCTION Coitus in snakes may last up to 28 hours; however, the mechanisms involved are unknown. AIM To evaluate the relevance of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-phosphodiesterase type 5 (PDE5) system in snake corpus cavernosum reactivity. METHODS Hemipenes were removed from anesthetized South American rattlesnakes(More)
The response to endothelin, a novel 21-amino acid peptide, is investigated in isolated aortas with and without endothelium and in mesenteric microvessels in vivo-in situ, in Goldblatt II (GII) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Median effective concentrations and maximal responses to endothelin did not differ in aortas with(More)
Most amniotes vertebrates have an intromittent organ to deliver semen. The reptile Sphenodon and most birds lost the ancestral penis and developed a cloaca-cloaca mating. Known as hemipenises, the copulatory organ of Squamata shows unique features between the amniotes intromittent organ. They are the only paired intromittent organs across amniotes and are(More)
BACKGROUND Nanorap is a new nanotechnological formulation for topical anesthesia composed of lidocaine (2.5%) and prilocaine (2.5%). This study evaluated the pharmacokinetics of Nanorap. For the determination of lidocaine and prilocaine in human plasma, a new method using high-performance liquid chromatography coupled with tandem mass spectrometry was(More)
The two main approaches currently used for surgical treatment of esophageal cancer are transhiatal esophagectomy (THE) and esophagectomy through a right thoracotomy. Among technical variations of THE, wide opening of the diaphragm with ample mediastinal exposure allows resection under direct view with acceptable postoperative morbidity and mortality rates.(More)
Tinea nigra, a relatively uncommon mycosis caused by Phaeoannelomyces werneckii, is typically seen as an asymptomatic brown or black macule on the hands and feet. We present two cases of tinea nigra in children in São Paulo, Brazil, and alert readers to the potential for confusion with melanocytic lesions.
OBJECTIVE To assess the strategy of titration for prescribing an efficient dosage of propranolol to reduce myocardial ischemia in the elderly. METHODS The study comprised 14 elderly men (73.6 +/- 5.3 years) with stable coronary heart disease documented on coronary cineangiography, ischemic response to exercise testing, and preserved left ventricular(More)