Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Mais filtros

Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Biochem Biophys Res Commun ; 505(4): 1038-1042, 2018 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-30309652

RESUMO

Different spin labels were incorporated to the membranes of cultured insect UFL-AG-286 cells in order to characterize their physical properties by Electron Paramagnetic Resonance spectroscopy (EPR). The spectrum of the spin label 12-SASL incorporated to cell membranes was similar as those obtained in membrane model systems composed of eggPC/cholesterol. However, the spectrum of the spin label CSL, chemically related to cholesterol, was drastically different in the two systems. Interestingly, when cell cholesterol content was reduced using methyl beta cyclodextrin, an EPR spectrum similar to those of model membranes was obtained. The analysis of these experiments suggests the existence of cholesterol rich regions in UFL-AG-286 cell membranes.


Assuntos
Membrana Celular/química , Colesterol/química , Marcadores de Spin , Animais , Células Cultivadas , Espectroscopia de Ressonância de Spin Eletrônica , Lepidópteros , Lipídeos/química , Lipossomos/química
2.
Neurologia (Engl Ed) ; 38(2): 75-81, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35249845

RESUMO

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease affecting nerve transmission at the level of the neuromuscular junction, and typically causes fluctuating muscle weakness. Epidemiological studies show an increase in MG prevalence, particularly among the older population. OBJECTIVE: We performed a retrospective epidemiological study to determine the incidence and prevalence of MG in the province of Ourense (Galicia, Spain), characterised by population ageing. MATERIAL AND METHODS: Patients were selected from our clinical neuromuscular diseases database by searching for patients with an active prescription for pyridostigmine bromide. Incidence was estimated for the period 2009-2018. We calculated prevalence at 31/12/2018. According to census data for the province of Ourense, the population on 1/1/2019 was 307 651, of whom 96 544 (31.4%) were aged ≥ 65 years. RESULTS: We identified 80 cases of MG, with a prevalence rate of 260 cases/1 000 000 population (95% CI, 202.7-316.4), rising to 517.9/1 000 000 population in those aged ≥ 65 (95% CI, 363.2-672.9). Cumulative incidence in the study period was 15.4 cases per 1 000 000 person-years. Early onset (≤ 50 years) was recorded in 29.1% of cases. CONCLUSION: The prevalence of MG in our health district is one of the highest published figures, and the disease is highly prevalent in the older population.


Assuntos
Miastenia Gravis , Humanos , Espanha/epidemiologia , Estudos Retrospectivos , Miastenia Gravis/epidemiologia , Prevalência , Incidência
3.
Nutr Metab Cardiovasc Dis ; 21(1): 39-45, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19819118

RESUMO

BACKGROUND AND AIMS: Previous evidence suggests that dietary fat could influence the composition and size of triacylglycerols-rich lipoproteins (TRL). In a controlled intervention study on healthy subjects, we evaluated the influence of 3 dietary interventions, with different types of fat on postprandial TRL particle size and number. METHODS AND RESULTS: Volunteers followed three different diets for four weeks each, according to a randomized crossover design. Western diet: 15% protein, 47% carbohydrates (CHO), 38% fat (22% saturated fatty acid (SFA)); Mediterranean diet: 15% protein, 47% CHO, 38% fat (24% monounsaturated fatty acid (MUFA)); high CHO enriched with ALNA diet: 15% protein, 55% CHO, <30% fat (8% polyunsaturated fatty acid (PUFA)). After a 12-h fast, volunteers consumed a breakfast with 1g fat and 7 mg cholesterol per kg body weight and a fat composition similar to that consumed in each of the diets: Butter meal: 35% SFA; Olive oil meal: 36% MUFA; Walnut meal: 16% PUFA, 4% α-linolenic acid. Tryglicerides (TG) in TRL (large and small TRL) were determined by ultracentrifugation and size and number of lipoprotein particles were measured with Nuclear Magnetic Resonance Spectroscopy at different time points. The olive oil meal reduced the number of total TRL postprandial particles compared with the other meals (P=0.002). Moreover, the olive oil meal also increased the TRL particle size compared with the walnut meal (P=0.001). CONCLUSION: Our data showed that short-term intake of the Mediterranean diet and the acute intake of an olive oil meal lead to the formation of a reduced number and higher-size TRL particle compared with other fat sources. These novel findings have implications for understanding the postprandial lipoprotein mechanisms, and could favour the lower cardiovascular risk in Mediterranean countries.


Assuntos
Gorduras na Dieta/farmacologia , Lipoproteínas/sangue , Período Pós-Prandial/fisiologia , Triglicerídeos/sangue , Índice de Massa Corporal , Manteiga , VLDL-Colesterol/sangue , Estudos Cross-Over , Dieta , Dieta Mediterrânea , Carboidratos da Dieta/farmacologia , Ácidos Graxos/farmacologia , Humanos , Juglans , Lipídeos/sangue , Espectroscopia de Ressonância Magnética , Masculino , Azeite de Oliva , Tamanho da Partícula , Óleos de Plantas , Ultracentrifugação , Adulto Jovem
4.
Neurologia (Engl Ed) ; 2020 Sep 05.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32900528

RESUMO

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease affecting nerve transmission at the level of the neuromuscular junction, and typically causes fluctuating muscle weakness. Epidemiological studies show an increase in MG prevalence, particularly among the older population. OBJECTIVE: We performed a retrospective epidemiological study to determine the incidence and prevalence of MG in the province of Ourense (Galicia, Spain), characterised by population ageing. MATERIAL AND METHODS: Patients were selected from our clinical neuromuscular diseases database by searching for patients with an active prescription for pyridostigmine bromide. Incidence was estimated for the period 2009-2018. We calculated prevalence at 31/12/2018. According to census data for the province of Ourense, the population on 1/1/2019 was 307,651, of whom 96,544 (31.4%) were aged ≥ 65 years. RESULTS: We identified 80 cases of MG, with a prevalence rate of 260 cases/1 000 000 population (95% CI, 202.7-316.4), rising to 517.9/1 000 000 population in those aged ≥ 65 (95% CI, 363.2-672.9). Cumulative incidence in the study period was 15.4 cases per 1 000 000 person-years. Early onset (≤ 50 years) was recorded in 29.1% of cases. CONCLUSION: The prevalence of MG in our health district is one of the highest published figures, and the disease is highly prevalent in the older population.

6.
Chem Phys Lipids ; 147(1): 22-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17442288

RESUMO

The effect of arbutin, a 4-hydroxyphenyl-beta-glucopyranoside, on dimyristoylphosphatidylcholine (DMPC) bilayers was studied by turbidimetry, EPR and FTIR spectroscopies. The disruption of DMPC multilamellar vesicles (MLV's) with monomyristoylphosphatidylcholine (lysoPC), a product of hydrolysis of phospholipase A(2) (PLA(2)), is more efficient at 18 degrees C, where DMPC MLV's are known to be in the ripple P(beta') phase, than at 10 degrees C (L(beta') flat gel phase). Disruption at 18 degrees C was inhibited by increasing concentrations of arbutin in the solution. This inhibition was correlated with the disappearance of the ripple phase in MLV's when arbutin is present. Shifts in FTIR carbonyl bands caused by arbutin or by temperature changes allow us to propose a model. It is interpreted that the changes in the water-hydrocarbon interface caused by arbutin, forcing a reaccommodation of the carbonyl groups, eliminate the topological defects in the lattice due to mismatches among regions with different area per lipid where lysoPC can insert.


Assuntos
Arbutina/farmacologia , Dimiristoilfosfatidilcolina/química , Bicamadas Lipídicas , Espectroscopia de Ressonância de Spin Eletrônica , Espectroscopia de Infravermelho com Transformada de Fourier
8.
J Parasitol ; 92(1): 93-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16629322

RESUMO

Molecular techniques were used to examine the phylogenetic relationships among Hepatozoon species isolated from 13 foxes and 15 opossums from Brazil, and from 15 dogs, 20 foxes, 45 rodents, and 330 domestic cats from Spain. Hemogregarine infection was confirmed by amplification of the 18S rRNA gene and later sequencing. No hemogregarine infections were found in opossums. The prevalence of Hepatozoon in canids ranged from 26.6% (symptomatic domestic dogs) to 90% (Spanish foxes). Four different H. canis genotypes were detected, as well as an H. americanum-related protozoan (97% identical to the USA strain). Two Spanish cats were parasitized by a Hepatozoon species (0.6% prevalence) that showed 96% sequence identity to H. canis. DNA amplification assays performed on Spanish rodents showed 2 bank voles (Clethrionomys glareolus) to be infected by a Hepatozoon species (4.44% prevalence) with 95% sequence identity to Hepatozoon sp. from cats. Phylogenetic analysis showed Hepatozoon to be a monophyletic genus, in which species from carnivorous mammals (Hepatozoon sp. from cats, H. americanum and H. canis) appear as a sister lineage of that of lower vertebrates and rodents. This association suggests that H. americanum evolved in ticks and carnivores (either canids, or felids, or both) rather than in other ectoparasites and other types of mammal.


Assuntos
Coccidiose/veterinária , Ectoparasitoses/veterinária , Eucoccidiida/classificação , Eucoccidiida/genética , Mamíferos/parasitologia , Doenças Transmitidas por Carrapatos/veterinária , Animais , Brasil/epidemiologia , Gatos , Coccidiose/epidemiologia , Coccidiose/parasitologia , Primers do DNA/química , DNA de Protozoário/química , Cães , Ectoparasitoses/epidemiologia , Raposas/parasitologia , Genótipo , Ixodidae/parasitologia , Dados de Sequência Molecular , Gambás/parasitologia , Filogenia , Prevalência , RNA Ribossômico 18S/genética , Roedores , Espanha/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/parasitologia
9.
Int J Parasitol ; 19(1): 21-8, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2707959

RESUMO

Through ultrastructural study of the morphological forms developed in vitro during protoscolex culture, we describe larval E. granulosus histogenesis. The transformation of the spined microtriches in the protoscolex into truncated microtriches that develop within the hydatid cyst is discussed. The paper also describes the mitochondria location change that occurs during the evolution; the mitochondria pass from the most internal area of the distal cytoplasm along the cytoplasmic extensions into the cytoplasm of tegumental cells. The ultrastructures of both the vesiculated protoscolex and the posterior bladder demonstrate that each state corresponds to the initial step on one of the two paths of in vitro vesicular development.


Assuntos
Echinococcus/crescimento & desenvolvimento , Animais , Echinococcus/ultraestrutura , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Microscopia Eletrônica
10.
Int J Parasitol ; 24(2): 219-24, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8026899

RESUMO

Protoscoleces of Echinococcus granulosus were incubated in vitro with decreasing concentrations of either albendazole (ABZ) or albendazole sulphoxide (ABZ.SO) (50, 10, 1 and 0.1 micrograms ml-1), and in combination. Viability was assessed by the methylene blue exclusion test and establishment of infection in mice. Protoscolex ultrastructure was determined by means of transmission and scanning electron microscopy. ABZ and ABZ.SO, when used separately had protoscolicidal activity after a longer incubation period (30 days) than when used as combined compounds. When incubated in the presence of ABZ + ABZ.SO, protoscolex viability dropped rapidly. That is, protoscoleces were all non-viable at 12 days of exposure, with no cyst developing following their inoculation into mice. The ultrastructural changes induced by ABZ or ABZ.SO alone, were: (a) rostellar disorganization, (b) formation of numerous blebs on the tegument, (c) loss of the microtriches, (d) increased vesiculation within the tegumentary cytons together, (e) an increase in lipid deposits and (f) depletion of glycogen reserves. After incubation with combined ABZ and ABZ.SO the tegument contained numerous blebs which became detached, leaving debris only, some intact nuclei being discernible in the protoscolex parenchyma.


Assuntos
Albendazol/análogos & derivados , Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Echinococcus/efeitos dos fármacos , Animais , Meios de Cultura , Combinação de Medicamentos , Echinococcus/ultraestrutura , Microscopia Eletrônica , Microscopia Eletrônica de Varredura
11.
Int J Parasitol ; 26(1): 59-65, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9198597

RESUMO

This paper describes a novel experimental model for the screening of putative drugs against the metacestode stage of E. granulosus using hydatid cysts derived from in vitro culture of protoscoleces. The effects of an ABZ+ABZ.SO combination against cultured and murine cysts were studied with this in vitro model system. This treatment produced loss of turgidity of the cultured cysts in less time than in the murine cysts but the ultrastructural tissue damage observed in both cultured and murine cysts was similar. The ultrastructural changes induced by ABZ+ABZ.SO were: (i) vacuolation of the distal cytoplasm that extended to the tegumentary cells of the germinal membrane; (ii) increased number of mitochondria; (iii) partial loss of microtriches; (iv) increased number of autophagosomes; and (v) an increase in lipid deposits.


Assuntos
Albendazol/farmacologia , Anti-Helmínticos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Echinococcus/efeitos dos fármacos , Albendazol/análogos & derivados , Animais , Relação Dose-Resposta a Droga , Equinococose/veterinária , Echinococcus/crescimento & desenvolvimento , Echinococcus/ultraestrutura , Técnicas In Vitro , Ovinos , Doenças dos Ovinos/parasitologia
12.
Int J Parasitol ; 27(11): 1341-5, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9421721

RESUMO

This paper describes the effectiveness of ABZ, ABZ.SO and ABZ + ABZ.SO treatment in mice infected with Echinococcus granulosus protoscoleces. The results were evaluated in two ways: measuring the number and wet weight of developed cysts and by transmission electron microscopy (TEM) of tissue cyss. ABZ and ABZ + ABZ.SO had an important effect upon larval growth in E. granulosus. The ultrastructural changes noted were: vacuolation of tegumentary cells of the germinal membrane; increased number of mitochondria; increased number of autophagosomes and an increase in lipid deposits.


Assuntos
Albendazol/uso terapêutico , Anti-Helmínticos/uso terapêutico , Equinococose/terapia , Administração Oral , Albendazol/análogos & derivados , Animais , Combinação de Medicamentos , Equinococose/patologia , Feminino , Camundongos , Camundongos Endogâmicos
13.
Int J Parasitol ; 19(8): 945-7, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2635167

RESUMO

The in vitro effects of levamisole and ivermectin against Echinococcus granulosus protoscoleces were studied by means of light and electron microscopy. Both drugs had a protoscolicidal activity that increased proportionally with increasing concentrations of the drugs. Ivermectin showed the more rapid effects and caused contraction and paralysis of protoscoleces. A paralyzing effect was also observed with levamisole, followed by irreversible tissue vacuolation leading to death.


Assuntos
Echinococcus/efeitos dos fármacos , Ivermectina/farmacologia , Levamisol/farmacologia , Animais , Echinococcus/ultraestrutura , Microscopia Eletrônica , Microscopia Eletrônica de Varredura
14.
Int J Parasitol ; 22(3): 335-9, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1639569

RESUMO

The viability of hydatid cysts developed in vitro for 90 days was assessed by implantation into mice. Cysts removed from mice at 270 days post-infection (p.i.) increased their size 13.5-fold and contained several brood capsules containing protoscoleces. Thus, cysts remain viable after prolonged in vitro culture. The implantation in mice of 15 cysts developed in vitro yielded an average of 10 cysts per mouse, which is indicative of a high survival rate in these experimental infections. The ultrastructural study of cysts recovered from mice 270 days p.i. showed that the germinal membrane was more compact than before implantation and several layers of tegumental cells had developed. Observations of cysts removed from mice indicated that the plasma membrane surrounding microtriches had prolongations opening into the laminated layer.


Assuntos
Equinococose/parasitologia , Echinococcus/crescimento & desenvolvimento , Animais , Echinococcus/ultraestrutura , Camundongos , Microscopia Eletrônica
15.
Inorg Chem ; 38(16): 3598-3604, 1999 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-11671114

RESUMO

A new copper(II) compound, [Cu(L-proline)(2)](2).5H(2)O (C(20)Cu(2)H(42)N(4)O(13)) (called compound I) was synthesized and crystallized, and its structure was solved using X-ray methods. It is monoclinic, space group P2(1), with a = 11.187(1) Å, b = 12.172(3) Å, c = 11.661(1) Å, beta = 114.96(1) degrees, and Z = 2. There are two chemically different copper molecules (labeled A and B), both with the copper atom in a N(2)O(2) square planar coordination. Molecule type A has one water molecule in an apical position. Molecule B has water molecules in each of the two apical positions. Single-crystal EPR measurements have been performed in I and also in Cu(D,L-proline)(2).2H(2)O (compound II). From the similar angular variations of the position of the single resonance observed in both compounds, we evaluated the molecular g tensors. Interpretation of the molecular g tensors resulted in d(x)()()2(-)(y)()()2 orbital ground states. From the angular variations of the line width we calculated the magnitude of the exchange interactions coupling neighbor copper ions in each compound. In I copper ions type A at 7.25 Å are arranged in chains coupled through axial-equatorial bonds. The exchange coupling within these chains is |J/k| = 118 mK. The coupling between copper ions type B is weaker. However, the interactions between copper ions type A and B generate a three-dimensional magnetic network. Our data in compound II indicate that a superexchange pathway containing a weak hydrogen bond C-H- - -O is the path for an exchange interaction with |J'/k| = 48 mK between coppers in neighbor layers at 9.75 Å.

16.
J Inorg Biochem ; 84(3-4): 201-6, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11374582

RESUMO

We performed EPR measurements in powder and single crystal samples of bis(L-phenylalaninamidato)Cu(II) (C18H22CuN4O2). We evaluated the crystal and molecular g-factors, and estimate an exchange interaction of 0.15 K< or = J(AB)/k < or =0.32 K between coppers spaced apart 6.24 A, transmitted through an amidate bridge Cu-O-C-N-Cu. An unusual line shape is observed in powder samples arising from the relative orientation of symmetry-related molecules in the structure. The dipolar interaction and the layered structure of the copper ions produce a strong temperature variation of the spectral shape when the copper spins are polarized by the applied magnetic field.


Assuntos
Cobre/química , Compostos Organometálicos/química , Fenilalanina/química , Espectroscopia de Ressonância de Spin Eletrônica , Elétrons , Fenilalanina/análogos & derivados
17.
Rev Argent Microbiol ; 11(2): 49-56, 1979.
Artigo em Espanhol | MEDLINE | ID: mdl-122386

RESUMO

A study of 320 samples of mammary quarters from cows in 40 dairy farms around Santa Fe city during 1977-1978 was made. The samples were selected based on clinical examination and California Mastitis Test (GMT). High percentage of subclinical mastitis was found. The etiological agents most frequently isolated were Staphylococcus aureus (54,1%), Streptococcus agalactiae (23.4%) and Pseudomonas aeruginosa (13,2%). A winter increment of S. aureus (48,1%) and P. aeruginosa (3,7% and 22,5%) was observed. But S. agalactiae did not experiment considerable variation (26,8% and 20% throughout the year. The sensitivity to antibiotics of some strains decreased in winter specially in S. aureus and P. aeruginosa (61,5% and 38,9%), and some biochemical properties related with their virulence increased. Penicillin in milk was not detected, but the levels of contamination by non specific inhibitory substances were very high (40%). Besides it was found a great contamination with aerobic sporeforming bacteria in these samples, being Bacillus coagulans (59,1%), B. polymyxa (26,1%) and B. sphaericus (9,5%) the most frequent.


Assuntos
Mastite Bovina/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Streptococcus agalactiae/isolamento & purificação , Animais , Antibacterianos/farmacologia , Bovinos , Resistência Microbiana a Medicamentos , Feminino , Leite/microbiologia
20.
Parasitol Res ; 74(6): 558-62, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3194367

RESUMO

In vitro protoscolices of Echinococcus granulosus grew in a vesicular direction. After 9 days the laminated layer was observed; it reached thicknesses up to 140 micron. By day 125 of culture, the cysts had reached sizes of up to 4.875 micron and a high percentage of cysts had been obtained (10.4%). The ultrastructure of these cysts was studied and the existence of a germinal layer was demonstrated.


Assuntos
Echinococcus/crescimento & desenvolvimento , Animais , Echinococcus/ultraestrutura , Microscopia Eletrônica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA