Navegando por Assunto "Colesterol"

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Acesso aberto (Open Access)
Acúmulo de colesterol por Mycobacterium smegmatis como possível modulador da biossíntese de lipomanana e lipoarabinomanana
(Universidade Federal do Pará, 2015-02-26) SANTOS, Ana Cristina Doria dos; SENA, Chubert Bernardo Castro de; http://lattes.cnpq.br/8620752020290438
Mycobacterial cell wall is a hallmark of Mycobacterium genus, constituted of bioactive lipids and glycoconjugates: phosphatidylinositol mannoside (PIMs), lipomannan (LM) and lipoarabinomannan (LAM). The chronic infection inside lung macrophages is related with cholesterol accumulation into host cells as an alternative source of carbon and energy to maintain the bacilli with its physiological functions. To understand the activity of these immunomodulatory glycoconjugates during adaptation under the unusual environment inside the host infected cells, the present work propose to investigate the possible modulation of LM/LAM biosynthesis in Mycobacterium smegmatis (saprophytic) after culture in minimal medium (MM), supplemented with glycerol and/or cholesterol. Our results showed that saprophytic bacilli are able to accumulate the cholesterol and change the bacterial physiology due to slow growth and restrict cell density. Furthermore, the cholesterol consumption decreased the accumulation of PIMs and promoted morphological changes and bacterial aggregates, even maintaining the cell wall with its specific physic-chemistry characteristic (alcohol-acid resistance). The most impressive change after cholesterol consumption was the LAM biosynthesis, which showed distinct electrophoresis migration, compatible to high molecular weight of LAM from non-saprophytic bacilli (from 25 – 30 KDa to 30 – 50 KDa). These results showed that cholesterol consumption, when utilized as principal alternative of carbon and energy source, is able to induce physiological changes in mycobacteria, mainly in LAM biosynthesis, one of the most immunoregulatory molecules of cell wall. Ours data suggest that similar changes in mycobacteria may occur inside the granuloma, and that changes may help the evolution of tuberculosis to chronic and multibacillary form, hallmarked by immunodeficient aspect against the bacilli.
Acesso aberto (Open Access)
Composição centesimal, colesterol e maturação ovariana do Acetes marinus Omori, 1975 coletado no Baixo Tocantins
(Universidade Federal do Pará, 2007-11-30) ASSUNÇÃO, Antônia do Socorro Américo de; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; PAIVA, Rosildo Santos; http://lattes.cnpq.br/0510818763187669
The specie Acetes marinus Omori, 1975, have full use as food constituting themselves into a kind of nutritional importance to the regional population, however, it is few studied. To contribute to a better use of this resource were conducted monthly collections of A. marinus during the months of January 2006 to June 2007, in two beaches, near of the Cametá town in low Tocantins river. They were certain the composition centesimal (%) and the content of cholesterol (mg/100g) relating to environmental parameters: pH, temperature and material in suspension of the subsurface water. The characterization of ovarian development, were based on the macro-and microscopic changes. For these two beaches the annual average pH was 7.52 ± 0.71, the temperature was 26.57 ° C ± 1.26, and the material in suspension was 73mg / L ± 65.53. For the composition centesimal of A. marinus got itself: 87.1% ± 1.1- moisture; 9.8% ± 1.3-ash, 71% ± 1.8-protein, 5.4% ± 2.9-lipids; 13.7 % ± 2,6- carbohydrates; 387.6% ± 13.2 kcal - calorific value. The content of cholesterol was 374.87 mg/100g ± 207.08. Was revealed a large potential nutrition, especially protein, for this species, but it is rich in cholesterol. And for developing ovarian were described three stages of maturation, based on four different types of oocytes.
Acesso aberto (Open Access)
Correlação dos teores séricos entre mefloquina e carboximefloquina com os teores de colesterol total e frações e triglicerídeos em pacientes com malária por Plasmodium falciparum não complicada
(Universidade Federal do Pará, 2010) RIVERA, Juan Gonzalo Bardález; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
Malaria is a major cause of morbidity and mortality worldwide, with over 100 million cases and at least one million deaths annually. It is a disease prevalent in the countries of tropical and subtropical climate of the planet. In Brazil, it occurs mainly in the Amazon region where climatic conditions favor the breeding of the vector and the spread of disease. With the emergence of vector resistance to insecticides, the lack of an effective vaccine, and especially the resistance of plasmodia to antimalarial drugs available today, there has been a resurgence and spread of the disease worldwide. Among the drugs used to treat the disease stands to mefloquine, which has high lipid solubility, being associated to a specific polipetídio (apo-A1) present in high density lipoproteins (HDL). Thus, infected erythrocytes tend to bind to circulating HDL particles to obtain the lipid supply, which would favor the passage and accumulation of the drug in these. However, malaria patients showed abnormal lipid profile, such as decreased levels of cholesterol total, HDL and LDL cholesterol, elevated values of lactate dehydrogenase, and a moderate increase of triglyceride level. This study is the correlation between serum concentrations of total cholesterol, HDL, LDL and triglycerides in serum levels of mefloquine (MQ) and carboximefloquina (CMC) in patients with falciparum malaria not complicated. For this we used the biochemical determination through self-plush Cobas analyzer to determine the levels of serum cholesterol and triglycerides and high performance liquid chromatography for determination of serum levels of mefloquine and carboximefloquina. Significant difference in serum total cholesterol, and HDL and LDL, which increased over the course of clinical evaluation, which corroborates findings in the literature and there was significant difference in serum triglycerides, which decreased with clinical outcome of patients.
Acesso aberto (Open Access)
Estudo do mecanismo conformacional da proteína 3-hidroxi-3- metilglutaril Coenzima A Redutase (HMGR) com as estatinas e substrato através de Dinâmica Molecular, PCA e Energia Livre
(Universidade Federal do Pará, 2017-08-03) COSTA, Clauber Henrique Souza da; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/0000-0001-7270-1517
Cholesterol is a substance of paramount importance for all animals. However, its high level in the human body is linked to the two major diseases that kill the world: ischemic heart disease and stroke. One of the synthetic drugs used in the treatment of hypercholesterolemia are statins, inhibitors of 3-hydroxy-3-methylglutaryl Cozyme A reductase (HMGR), which act primarily on the liver by inhibiting a conversion of the HMG-CoA substrate into mevalonic acid, which is the metabolite Cholesterol precursor. Studies Molecular Dynamics (MD) combined with Principal Component Analysis (PCA) were performed to verify the mechanism of the changes in the Cterminal Flap domain form (residues His861, Leu862, Val863, Lys864, Ser865 and Hys866) after binding substrate and efficient statins in inhibiting the HMGR enzyme. A total of 500 ns of MD simulation time were performed in this study. Binding Free Energies calculations were used, which estimate that the structural mechanism of the Flap is related to an action of the HMGR protein, since domain control or access to the active site of the enzyme. The results also show that the structural modification of Flap increases the energy contribution of the system by involving larger interactions with catalytic residues and, consequently, an ability to inhibit cholesterol production, as observed for the catalytic His866, which has a very favorable contribution when the Flap is in the closed state, with energy of -14,802 Kcal/mol, and when the Flap passes to the open state the contribution is less favorable, with -1,022 Kcal/mol, for 1 inhibitor, showing that in the closed state the catalytic residue is directly involved and contributes in a favorable way to the system, leading to a better understanding of the conformational changes of HMGR after a binding of statin derivatives and HMG-CoA substrate.
Acesso aberto (Open Access)
O papel do colesterol na biossíntese da parede celular de Mycobacterium smegmatis
(Universidade Federal do Pará, 2015-02-26) MARINHO, Victor Hugo de Souza; SENA, Chubert Bernardo Castro de; http://lattes.cnpq.br/8620752020290438
Different Mycobacterium species are causative agents of disease in humans, for example, the tuberculosis. All mycobacteria have a complex cell wall, distinct of others bacteria, conferring specific physic-chemical characteristic to Mycobacterium genus, due to protect against immune system and waterproofing against the intake of much antibiotics. During infection, the bacillus is able to adapter to harsh environment, due to consumption of cholesterol from itself host cell (macrophages) as alternative carbon and energy source. That nutritional aspect has been considered as essential for division of bacilli and consecutive progress of tuberculosis disease. The present study has as objective to evaluate in vitro the modulation of saprophytic Mycobacterium smegmatis cell wall biosynthesis after cholesterol consumption as primordial energy and carbon source. As results, we are found by Thin Layer Chromatography (TLC) that bacillary adaptation to microenvironment with poor nutrient (minimal media – MM) maintained the biosynthesis and accumulation of essential cell wall components, when the growth occurs in presence of someone defined carbon and energy source (glycerol and/or cholesterol). Among them without changes, we analyzed Trehalose Dimicolate (TDM) and the phospholipids (phosphatidylinositol (PI), phosphatidylinositol manosides (PIMs), Cardiolipin (CL) and phosphatidylethanolamine (PE)). Differently of these results, the micolic acid showed representative accumulation, comparing with 7H9 culture, only when the MM was supplemented with glycerol. This result was confirmed by alcohol-acid staining using fluorescent auroamine dye, suggesting some changes in physic-chemistry cell wall properties. On the other hands, the MM culture induced the accumulation of glycopeptidolipids (GPLs), independently of glycerol/cholesterol supplementation. Such disturbance in cell wall biosynthesis also changed the bacillary hydrophobicity in all MM groups, but does not change the resistance and sensibility to antibiotics. Those results clearly show that cell wall biosynthesis might be modulate during nutritional shortage, and such presence or absence of cholesterol, as occurs during infection, does not significantly change the bacillary physiology to become vulnerable for antibiotics. It suggests that such modulations might also occur during infection, maintaining the bacilli available to develop the tuberculosis diseases.
Acesso aberto (Open Access)
Perfil lipidico de uma população residente em área de alta endemicidade para malária
(Universidade Federal do Pará, 2012) NEVES, Frederico Augusto Rocha; LIBONATI, Rosana Maria Feio; http://lattes.cnpq.br/3818175484709618
Malaria is an infectious disease caused by a protozoan of the genus Plasmodium. In the Brazilian Amazon malaria is endemic, where more than 99% of the notifications of the disease. The municipality of Anajás, located in Pará State, was found an Annual Parasite Incidence (API = 57.7). The study was a cross-sectional controlled, having as main objective to evaluate the impact of malaria on lipid parameters of a population living in a highly endemic area. To this end, we considered three groups of patients: Group I: patients with malaria (n = 64), Group II: patients without malaria (n = 46), both groups consist of people living in the city of Anajás - Pará, and another Group III: patients with no history of malaria (n = 46) and residing in Belém – Pará. Was analyzed the levels of total cholesterol and triglyceride fractions and of all individuals included in the study. The analyzes showed that females were more affected and the species P. falciparum was more frequent. Mean total HDL cholesterol, LDL cholesterol, VLDL cholesterol and triglycerides were statistically significant only for patients with malaria (Group I) and mean LDL cholesterol was statistically significant in all groups evaluated. To investigate the past malarial population three subgroups were created from the group of patients without malaria Anajás, Groups Iia, IIb and IIc. For this evaluation used the average total cholesterol and triglyceride fractions and was observed that the greater the number of episodes of malaria, higher HDL cholesterol levels and lower LDL cholesterol levels in patients in this subgroup.