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Biomedical subjects

E Salas

Publications and source records attributed to E Salas.

At least 109 records · Page 6Linked to original sources
PubMed1991

[Comparative cytotaxonomy of 3 species of Cichlasoma (Pisces: Cichlidae) native of Costa Rica].

The karyotype of three species of Cichlasoma: C. dovii, C. managuense and C. friedrichstali were studied. The number of diploid chromosomes is 2n = 48 in the first two species. Their karyotypes are composed of four pairs of meta-submetacentric chromosomes. The arms fundamental number (NF) is 56. C. friedrichstali has three pairs of meta-submetacentric chromosomes and 21 pairs of subtelocentric-telocentric chromosomes. This species presents two different diploid numbers, 2n = 48 and 2n = 47.

Animals↗
PubMed1986

The Multiple Forms of alpha-Amylase Enzyme of the Araucaria Species of South America: A. araucana (Mol.) Koch and A. angustifolia (Bert.) O. Kutz : A Comparative Study.

alpha-Amylase is one of the major enzymes present in the seeds of both Araucaria species of South America and it initiates starch hydrolysis during germination and early seedling growth. The pattern of the multiple forms of alpha-amylase of the two Araucaria species was investigated by electrophoresis and isoelectrofocusing of the native enzyme in polyacrylamide gels. The enzyme forms were compared in the embryo and megagametophyte of quiescent seeds and of seeds imbibed for 18, 48, and 90 hours. Specific alpha-amylase enzyme forms appear and disappear during these imbibition periods showing both similarities and differences between tissues and species. Before imbibition, there are five alpha-amylase forms identical in both tissues, but different between species. After 18 hours of imbibition, there are two enzyme forms in both tissues of Araucaria araucana seeds, only one form in the embryo of Araucaria angustifolia but two forms in the megagametophyte of this specie. After 48 hours of seed imbibition, most of the enzyme forms present in quiescent seeds reappear. At 90 hours of imbibition different enzyme forms are detected in the embryo with respect to the gametophyte. The changes in form patterns of alpha-amylase are discussed according to a possible regulation of gene expression by endogenous gibberellins.

Journal Article↗
PubMedDate not supplied

Human mesenchymal stem cells are tolerized by mice and improve skin and spinal cord injuries.

INTRODUCTION: We sought to use human mesenchymal stem cells (HMSC) for skin and spinal cord repair in mice. MATERIALS AND METHODS: Human bone marrow obtained from a young healthy donor was used to separate and culture human mesenchymal stem cells (HMSC). Ten mice were included in each of four groups. A full-thickness skin defect was surgically performed on all mice in groups 1 and 2. A transverse complete medullar section was performed in groups 3 and 4. Groups 1 and 3 received HMSC IV infusion and local HMSC polymer implant. Groups 2 and 4 received only the IV HMSC infusion. Five control animals from each group went through the same lesions but they didn't receive treatment. RESULTS: After local administration of HMSC into the fibrin polymer combined with the IV infusion of HMSC, there was no immune rejection; all skin defects healed without scar or retraction at a median time of 14 days. Sixty percent of the animals treated with IV infusion and polymer with HMSC simultaneously had improved neurological activities, while all control mice with spinal cord injury experiments died or perpetuated their paralysis with worsening muscular atrophy and increasing propensity to skin damage. CONCLUSIONS: HMSC are not immunologically reactive and can trespass species defense barriers. Animals treated with these cells repaired injuries better than controls. In this way we propose that universal HMSC from donors can be cultured, expanded, and cryopreserved to be used in human organ or tissue regeneration.

Animals↗
PubMedDate not supplied

Matrix metalloproteinase-2 in platelet adhesion to fibrinogen: interactions with nitric oxide.

BACKGROUND: Matrix metalloproteinase-2 (MMP-2) has been shown to activate a non-thromboxane, non-ADP pathway of platelet aggregation. In contrast, nitric oxide (NO) is known to inhibit platelet adhesion and aggregation. Therefore, we have studied the release of MMP-2 during platelet adhesion to fibrinogen, the effects of phenanthrolione, an MMP-2 inhibitor, on adhesion and the interactions of inhibitor with a NO donor, S-nitroso-N-acetyl-D, L-penicillamine (SNAP). MATERIAL AND METHODS: Human platelets were isolated from blood of healthy volunteers and platelet adhesion to fibrinogen-coated plates was studied by measuring thrombin-stimulated release of platelet a-granule constituent, platelet factor 4. In addition, the mode of action of phenanthroline and NO on platelets was investigated by assaying the levels of intraplatelet cyclic GMP. RESULTS: Thrombin-stimulated platelet adhesion to fibrinogen was associated with increased release of MMP-2 from platelets. Phenanthroline (0.1-100 KM) reduced platelet adhesion to fibrinogen. The adhesion was also inhibited by SNAP (0.1-100 KM), an effect abolished by 1H-[1,2,4] oxadiazolol [4,3,-a] quinoxalin-1-one (ODQ), a selective inhibitor of the soluble guanylate cyclase. Co-administration of phenanthroline and SNAP resulted in a synergistic inhibition of platelet adhesion, an effect that was not associated with enhanced cyclic GMP generation by platelets. Furthermore, ODQ did not reverse the synergistic effect of these compounds on adhesion. CONCLUSIONS: 1. MMP-2 promotes platelet adhesion to fibrinogen. 2. Phenanthroline and NO synergize to inhibit platelet adhesion to fibrinogen acting through a cyclic GMP-independent mechanism(s).

Blood Platelets↗
PubMedDate not supplied

[Chronotropic changes and cardiac arrhythmias during anesthetic induction and intubation in patients undergoing heart surgery. Study of 79 patients using Holter monitoring].

OBJECTIVES: To assess changes in heart rate and cardiac arrhythmias during anaesthetic induction and tracheal intubation in patients undergoing cardiac surgery. MATERIAL AND METHODS: 79 patients scheduled for cardiac surgery were divided into three groups: group I, 36 valvular diseases with a good ventricular function, group II, 22 valvular diseases with an ejection fraction less than 0.5, and group III, included 21 patients with coronary artery disease. All patients had a Holter monitoring. Anesthesia was performed with diazepam and morphine in patients with valvular disease and with diazepam and fentanyl in those with coronary artery disease. RESULTS: During anesthesia induction there were no significant increases in heart rate in the two groups of patients with valvular diseases: in group I (n = 36, with good ventricular function) heart rate increased by about 5.4 +/- 23% and in group II (n = 22, with ejection fraction less than 0.5) by 7.5 +/- 33%. In patients with coronary artery disease (n = 21) we did not observe significant decreases in heart rate (-4.28 +/- 17%). During tracheal intubation the heart rate increased by 15.9 +/- 30% in group I (p < 0.002), by 13.6 +/- 30% in group II (p < 0.02), but decreased by 1.19 +/- 23% (p = NS) in patients with coronary artery disease. During anesthetic induction we observed frequent premature beats (single forms) in 13.8% of patients in group I, 13.6% in group II, and 9.5% in group III. The incidence of this arrhythmia during tracheal intubation was 16.6%, 9%, and 14%, respectively for the three groups. Sustained ventricular tachycardia was only observed in one patient. CONCLUSIONS: Changes in heart rate and ventricular arrhythmias occurring during anesthetic induction and tracheal intubation in patients undergoing valvular and coronary surgery were infrequent and not severe.

Adult↗
PubMedDate not supplied

[Parathyroid function in hypertrophic myocardiopathy].

It has been suggested that hypertrophic cardiomyopathy (HCM) may be associated with hyperparathyroidism. We evaluated parathyroid function in 15 patients with HCM and 14 patients with primary dilated cardiomyopathy (DCM), measuring different parameters of calcium metabolism (total serum calcium, ionized calcium, PTH, vitamin D metabolites, alkaline phosphatase, osteocalcin). As a group PTH levels were normal in HCM (intact PTH 3.9 +/- 1.6 pmol/l, midmolecular PTH 59 +/- 13 pmol/l and carboxyterminal PTH 0.6 +/- 0.4 ng/ml), but in 3 patients carboxyterminal PTH levels were persistently higher than normal, while all other parameters of calcium metabolism were normal. We conclude that parathyroid function is normal in patients with HCM, although some of them may have an abnormal secretion and/or metabolism of carboxyterminal PTH fragments, or a circulating substance the interferes with this PTH assay. Parathyroid function in DCM patients was normal, except in a patient who had hyperparathyroidism secondary to vitamin D deficiency.

Adult↗
PubMedDate not supplied

[The transcutaneous treatment of superficial thrombophlebitis with the exogenous nitric oxide donor: nitroglycerin].

Nitroglycerin (glyceryl trinitrate) is a substance that is metabolized to nitric oxide in the cell. Its action is not dependent of the endothelium derived nitric oxide, but imitates those of this biological mediator. We thought that nitroglycerin should have the same in vivo actions as the endogenous nitric oxide in vitro has. We report and discuss the first patient with superficial thrombophlebitis successfully treated with transdermal nitroglycerin.

Acute Disease↗