RESUMO
A pesar de los avances en los protocolos de tratamiento y en las medidas de soporte en pacientes con Leucemia Mieloide Aguda (LMA), 27% presentan recaídas de la enfermedad. Esto se debe, entre otras causas, a la persistencia de pequeñas cantidades de células malignas (blastos) resistentes a la terapia. Estas pequeñas cantidades de blastos remanentes se denominan Enfermedad Mínima Residual (EMR). La determinación de EMR requiere de técnicas no solo muy sensibles, sino también específicas, y permite evaluar la respuesta individual a la terapia. La introducción de la EMR como parámetro de respuesta y estratificación está bien definida en Leucemia Linfoblástica Aguda (LLA). Por el contrario, aunque existen publicaciones sobre el impacto pronóstico de la EMR en LMA, aún no se encuentra incluida en forma sistemática en los protocolos nacionales actuales, entre otros motivos, por lo laborioso de la determinación y por la necesidad de validación de la misma. Debe tenerse en cuenta que el inmunofenotipo de los blastos mieloides suele ser más heterogéneo que el de los blastos en LLA, presentando, en muchos casos, subpoblaciones diferentes entre sí, lo cual dificulta su detección certera y no hay consenso definido en cuanto a la metodología más eficaz. En este trabajo describimos una nueva estrategia de marcación y análisis estandarizada en un estudio multicéntrico internacional para LMA y la utilidad de la EMR como parámetro de respuesta y de estratificación. Asimismo, detallamos los resultados preliminares de nuestra cohorte de pacientes (AU)
Despite the improvement in treatment and supportive care of patients with Acute Myeloid Leukemia (AML), 27% of them relapse. This is due to the persistence of small amounts of malignant cells (blasts) resistant to therapy, among other causes. These small amounts of blasts are called Minimal Residual Disease (MRD). The determination of MRD requires not only techniques with high sensitivity but also with high specificity, and allows to evaluate the individual response to treatment. The introduction of MRD as a response parameter is well established in Acute Lymphoblastic Leukemia (ALL), and it is used in current stratification protocols. On the other hand, even though there are some reports regarding the prognostic impact of MRD in AML, it is still not included in the current national protocols due to the lack of validation of the determination, among other causes. This is due to the fact that the immunophenotype of myeloid blasts is more heterogeneous than in ALL, presenting different subpopulations, which difficults their accurate detection. Thus, there is still no consensus regarding the most effective approach. In this article, we describe a new staining and analysis strategy standardized by an international multicentric study, and the utility of EMR as a response and stratification parameter. Additionally, we show the preliminary results of our patient cohort. (AU)
Assuntos
Humanos , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/terapia , Imunofenotipagem/instrumentação , Neoplasia Residual/diagnóstico , Citometria de Fluxo/instrumentaçãoRESUMO
La mayoría de las Leucemias Agudas (LA) pediátricas pueden clasificarse como Linfoblásticas (principalmente de fenotipo B o T) o Mieloblásticas dependiendo del linaje celular de los blastos, recibiendo tratamiento específico de acuerdo a esta caracterización. La inmunotipificación de las LA se basa en la evaluación de la expresión de antígenos de superficie y/o intracitoplasmáticos de diferenciación linfoide (B o T) o mieloide (My) en los blastos, lo cual permite definir la estirpe celular y clasificar la LA de acuerdo al grado de maduración. Sin embargo, existen grupos particulares poco frecuentes de LA cuya clasificación resulta dificultosa y por eso se las denomina LA de linaje ambiguo (fenotipo mixto/indiferenciadas) y LA de linaje dendrítico. Las de fenotipo mixto son aquellas en las que los blastos expresan marcadores de más de un linaje, y las indiferenciadas aquellas que no expresan antígenos específicos para ningún linaje. Diferentes convenciones se han ido desarrollando para definir y clasificar estos fenotipos inusuales, siendo la más actualizada la propuesta por la Organización Mundial de la Salud (2008). De acuerdo a estas pautas, de 1301 casos de LA diagnosticados entre abril de 1994 y abril de 2009, 28 fueron re-clasificados como LA de linaje Ambiguo, 3 como leucemia mieloide aguda minimamente diferenciadas y 3 como LA de células dendríticas. Debido a lo infrecuente de estos casos, su caracterización resulta relevante, ya que la bibliografía presenta, en general, sólo comunicaciones esporádicas de estos fenotipos particulares. Dada la importante casuística del Hospital Garrahan y el amplio seguimiento de los pacientes, el relevamiento de estos casos inusuales permite caracterizarlos desde el inmunofenotipo, la morfología/citoquímica, la citogenética/biología molecular y evaluar su presentación clínica, evolución, respuesta al tratamiento y sobrevida libre de eventos con la finalidad de colaborar con la definición de su pronóstico y eventualmente con la elaboración de protocolos de tratamiento diferenciados para estos subgrupos de LA (AU)
The majority of childhood acute leukemias (AL) can be classified as lymphoblastic (mainly phenotype B or T) or myeloblastic, depending on the cell lineage of the blasts, requiring specific treatment according to this characterization. Immunotypification of AL is based on surface and/or intracytoplasmic antigen expression with lymhoid (B or T) or myeloide (My) blast differentiation, allowing definition of cell lineage and classification of the AL according to the grade of maturation. Nevertheless, there are rare cases of AL that are difficult to classify, denominated AL of ambiguous lineage (mixed/undifferentiated lineage) and acute dendritic cell leukemia. In AL of the mixed phenotype, the blasts express markers of more than one lineage and in undifferentiated AL, the blasts lack antigen expression of any specific lineage. Different conventions have tried to define and classify these unusual phenotypes, among which the most recent proposal of the World Health Organization (2008). According to the criteria of the latter, of 1301 cases of AL diagnosed between April 1994 and April 2009, 28 were re-classified as AL of ambiguous lineage, 3 as minimally differentiated acute myeloid leukemia, and 3 as acute dendritic cell leukemia. Characterization of these cases is important, as in the literature only sporadic reports of these rare phenotypes are found. Given the large number of patients with a long follow-up of the Garrahan Hospital, a review of these unusual cases allowed characterization from the point of view of the immunophenotype, morphology/cytochemistry, cytogenetics/molecular biology and to evaluate clinical presentation, evolution, response to treatment, and event-free survival to help define the prognosis and develop protocols for the treatment of these subgroups of AL (AU)
Assuntos
Humanos , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Leucemia Aguda Bifenotípica/classificação , Leucemia Aguda Bifenotípica/diagnóstico , Leucemia Aguda Bifenotípica/genética , Leucemia/classificação , Imunofenotipagem , Células Dendríticas , Doença AgudaRESUMO
Mutations in IFNGR1, IFNGR2, IL12RB1, IL12B, STAT1 and NEMO result in a common clinical phenotype known as Mendelian Susceptibility to Mycobacterial Diseases (MSMD). Interleukin-12 receptor beta1 (IL-12Rbeta1) deficiency is the most common genetic etiology for MSMD. Known mutations affecting IL12RB1 are recessively inherited and are associated with null response to both IL-12 and IL-23. Mutation IL12RB1 1623_1624delinsTT was originally described in 5 families from European origin (2 from Germany; 1 from Cyprus, France and Belgium). Interestingly, this same mutation was found in an unexpectedly high prevalence among IL-12Rbeta1 deficient patients in Argentina: 5-out-of-6 individuals born to unrelated families carried this particular change. To determine whether mutation 1623_1624delinsTT represents a DNA mutational hotspot or a founder effect, 34 polymorphic markers internal or proximal to IL12RB1 were studied in the Argentinean and the Belgian patients. A common haplotype spanning 1.45-3.51Mb was shared by all chromosomes carrying mutation 1623_1624delinsTT, and was not detected on 100 control chromosomes. Applying a modified likelihood-based method the age of the most recent common ancestor carrying mutation 1623_1624delinsTT was estimated in 475 years (95% CI, 175-1275), which is the time when the Spaniards initiated the colonization of the Americas. Mutation 1623_1624delinsTT represents the first founder effect described on IL-12Rbeta1, the most frequently affected gene in MSMD, and affecting patients with European ancestors. The reason(s) behind the persistency of this mutation across multiple generations, its relative high prevalence, and any potential selective advantage are yet to be established.
Assuntos
Efeito Fundador , Predisposição Genética para Doença , Infecções por Mycobacterium/genética , Receptores de Interleucina-12/genética , Animais , Argentina , Vacina BCG/administração & dosagem , Vacina BCG/efeitos adversos , Humanos , Desequilíbrio de Ligação , Modelos Genéticos , Mutação , Mycobacterium bovis/isolamento & purificação , População Branca/genéticaRESUMO
Objetivos. Evaluar los efectos clínicos y preventivos de la inmunoterapia sublingual (SLIT) con respecto a la aparición de asma persistente, nuevas sensibilizaciones, síntomas clínicos e hiperreactividad bronquial (HRB). Los objetivos secundarios fueron: evaluar la magnitud del efecto clínico y el efecto sobre la HRB; ver la seguridad y adhesión a la SLIT. Material y métodos: Participaron 216 niños, de ambos sexos, entre 5 y 17 años, pacientes del Hospital Cuasso al Monte, Varese, Italia, con rinitis alérgica de al menos 2 años de evolución, con o sin síntomas de asma intermitente, y con diagnóstico de etiología alérgica confirmado para ácaros, gramíneas, árboles y malezas. Se excluyeron pacientes con asma persistente o VEF1 <80%, uso previo de inmunoterapia, anormalidades anatómicas de las vías aéreas superiores, enfermedades sistémicas crónicas (malignas o autoinmunes) y sensibilizaciones a epitelios y hongos anemófilos. Para los diagnósticos de rinitis y asma se emplearon las guías actuales (ARIA, GINA). Se realizaron prick test con panel estándar de alérgenos relevantes (ALK Abelló), histamina 1% y control negativo al principio y al final del estudio. Las pruebas de función pulmonar consistieron en espirometría computarizada con cabina pletismográfica y prueba de provocación no específica con metacolina con dosis progresivas desde 30 a 1.290 µg, durante el período de máxima exposición alérgenica según sensibilidad de cada paciente, al inicio y al final del estudio. A los pacientes con prueba negativa (descenso del VEFI <20%) se los consederaba con diagnóstico de rinitis exclusivamente. El estudi tuvo un período basal de 1 año de observación y luego una fase de aleatorización de 3 años de tratamiento abierto con dos ramas. Un grupo de pacientes utilizó drogas exclusivamente, y otro grupo drogas más SLIT (con una distribución 1/2).
Assuntos
Asma/terapia , Dessensibilização Imunológica/efeitos adversos , Dessensibilização Imunológica/métodos , Imunoterapia/métodos , Administração Sublingual , Hiper-Reatividade Brônquica/terapiaRESUMO
Muchos avances se han logrado en los últimos 30 años en el tratamiento de la leucemia linfoblástica aguda (LLA) pediática, a nivel mundial y tamibén en nuestro Hospital. Después de su apertura en agosto de 1987 hasta noviembre de 2002 fueron ingresados 989 pacientes con diagnóstico de LLA de los cuales 896 fueron evaluables. Los mismos fueron tratados con 3 protocolos sucesivos: 92 (7 LLa 87), 374 (1 LLA 90) y 430 (1 LLA 96). Las tasas de remisión completa (RC) fueron de 95,6 en el primer protocolo, 94,4 en el segundo y 96,9 en el tercero y un 2,1, 2,9 y 1,8 de los pacientes fallecieron durante la inducción en los respectivos estudios. El principal evento observado fue la recaída de la enfermedad y fallecieron en RC 6 de los pacientes del 7 LLA 87, 4,8 del 1 LLA 90 y 4,3 del 1 LLA 96. La pSLE (EE) fue de 61 (5), 63 (5) y 72 (6), respectivamente, siendo esta diferencia estadísticamente significativa (p=0,0237). El Hospital ha incorporado los métodos diagnósticos necesarios para una mejor estratificicón de los pacientes, y fueron mejoradas las medidas de soporte ofrecidas a los pacientes. Como consecuencia de los logros mencionados se observó una disminución en las tasas de muerte durante la inducción y en RC, con un aumento gradual y significativo de la pSLE. Estos resultados muestran una mejora a lo largo del tiempo y nuestros esfuerzos deben orientarse a una aún mejor optimización de las herramientas diagnósticas, terpéuticas y de soporte para lograr alcanzar los estándares internacionales pra esta población de pacientes.
Assuntos
Criança , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Guias como Assunto , Tratamento Farmacológico , Interpretação Estatística de DadosRESUMO
OBJECTIVE: To assess whether different types of malformation of cortical development (MCD) are associated with specific patterns of hippocampal abnormalities. METHODS: A total of 122 consecutive patients with MRI diagnosis of MCD (53 males, age range 1-58 years) were included in the study. Hippocampal measurements were made on 1-3 mm coronal T1-weighted MRIs and compared with MRIs of normal controls. RESULTS: A total of 39 patients had focal cortical dysplasia, 5 had hemimegalencephaly, 5 had lissencephaly-agyria-pachygyria, 11 had SLH, 11 had PNH, 12 had bilateral contiguous PNH, 5 had schizencephaly, and 34 had polymicrogyria. The frequency of hippocampal abnormalities in these patients with MCD was 29.5%. A small hippocampus was present in all types of MCD. Only patients with lissencephaly and SLH had an enlarged hippocampus. Abnormalities in hippocampal rotation and shape were present in all types of MCD; however, these predominated in PNH. None of the patients with lissencephaly-agyria-pachygyria or SLH had hyperintense signal on T2 or FLAIR images or abnormal hippocampal internal architecture. CONCLUSION: A small hippocampus was present in all types of MCD; however, the classic MRI characteristics of hippocampal sclerosis were often lacking. Abnormal enlargement of the hippocampus was associated with only diffuse MCD due to abnormal neuronal migration (lissencephaly-agyria-pachygyria and SLH).
Assuntos
Córtex Cerebral/anormalidades , Hipocampo/anormalidades , Malformações do Sistema Nervoso/diagnóstico , Adolescente , Adulto , Córtex Cerebral/patologia , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Hipocampo/patologia , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Exame Neurológico , Neurônios/patologia , Estatística como AssuntoRESUMO
Patients with mutations in the IFNgamma/IL-12 pathway show an exquisite susceptibility to mycobacterial diseases. An IL-12Rbeta1 deficient patient with impaired intestinal absorption suffered from a 13 year culture-positive Mycobacterium bovis-BCG infection with acquired multidrug resistance. A combined parenteral and enteral anti-mycobacterial treatment, including recombinant IFNgamma, helped to clear his infection.
Assuntos
Antituberculosos/uso terapêutico , Mycobacterium bovis/isolamento & purificação , Receptores de Interleucina-12/deficiência , Tuberculose/tratamento farmacológico , Tuberculose/genética , Adolescente , Antituberculosos/efeitos adversos , Predisposição Genética para Doença , Humanos , Masculino , Receptores de Interleucina-12/genética , Tuberculose/microbiologiaRESUMO
A sucrose-rich diet generates time-dependent metabolic disorders similar to those found in diabetes type 2. After 8 month (mo) this diet evoked in the rat an increase of blood glucose, free fatty acids (FFA) and triacylycerides (TG) without insulin modification, an interruption of liver stearoyl-CoA desaturase-1 (SCD-1) mRNA and activity increase found at 6 mo, and an enhacement of Delta6 and Delta5 desaturase mRNA and Delta6 activity. We found that the administration of troglitazone (TRO), a peroxisome-proliferator-activated receptors gamma (PPAR-gamma) agonist, for 2 mo normalized plasma FFA, TG, and glucose without altering the insulinemia. It depressed liver SCD-1 mRNA in both control and sucrose-fed rats, decreasing the 18:1n-9/18:0 ratio in serum and liver lipids, and eliminated the increasing effect on mRNA and activity of Delta6 and Delta5 desaturases. These findings evidence again that desaturases are not affected through an insulin resistant effect evoked by the sucrose-rich diet and TRO recovers the altered metabolic plasma parameters as it corresponds to a PPAR-gamma agonist, but its effect on hepatic desaturases can not be attributed to a direct action on liver by PPAR-gamma, insulin, and even by an insulin sensitizing mechanism, suggesting it would be evoked indirectly through hepatic PPAR-alpha deactivation induced by the FFA decrease.
Assuntos
Cromanos/farmacologia , Carboidratos da Dieta/farmacologia , Modelos Animais de Doenças , Ácidos Graxos Dessaturases/metabolismo , Resistência à Insulina , Sacarose/farmacologia , Tiazolidinedionas/farmacologia , Animais , Carboidratos da Dieta/administração & dosagem , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Microssomos Hepáticos/metabolismo , Plasma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Sacarose/administração & dosagem , TroglitazonaRESUMO
BACKGROUND: T-cell depletion (TCD) of BM allows transplantation across HLA barriers. Although different methods are used throughout the world, the optimal application of TCD still remains unclear, partly due to the lack of thorough analyses of the cellular fractions eliminated or retained in each method, and their possible implications regarding GvHD, GvL, or engraftment. We have analyzed the phenotype of the successive fractions of 19 BM samples depleted by soybean lectin agglutination and sheep erythrocyte rosetting (elimination of T cells that form rosettes through CD2), focusing on the final fraction infused to patients. METHODS: Analysis was performed using three-color flow cytometry and strategies for optimal staining and individualism of the subsets of interest. RESULTS: The relative composition of the lymphoid population varied significantly along the successive steps in TCD: at the agglutination step, B cells and CD4 T cells are greatly reduced, while natural killer cells (NK) and TCRgammadelta+ T are augmented. The rosetting steps imply the relative enrichment of CD2-dim T cells, together with a further rise in the proportion of NK and double-negative T cells frequently TCRgammadelta+. DISCUSSION: The presence of minor subsets of CD2- TCRgammadelta+ and CD2- TCRalphabeta T cells has already been described in the peripheral blood of normal individuals. We report that, by using this method of TCD, CD2-dim T cells, frequently TCRgammadelta+, are retained in the grafts and infused in patients, together with NK cells as the main lymphoid population. We discuss the possible implications of these populations in the biology of the graft, regarding GvHD, GvL and engraftment.
Assuntos
Células da Medula Óssea/metabolismo , Complexo CD3/metabolismo , Células Matadoras Naturais/metabolismo , Linfócitos T/metabolismo , Animais , Eritrócitos/metabolismo , Citometria de Fluxo , Humanos , Lectinas de Plantas/metabolismo , Ovinos/metabolismoRESUMO
Streptozotocin diabetes depresses delta 9, delta 6 and delta 5 fatty acid desaturases, decreasing arachidonic acid and increasing linoleic acid, but also unexpectedly increasing docosahexaenoic acid in the different phospholipids of liver microsomal lipids. 18:0/20:4n-6, 16:0/20:4n-6 and 16:0/18:2n-6 are the predominant phosphatidyl choline (PC) molecular species in control rats, determining mainly PC contribution to the dynamic and biochemical properties of this bilayer. Diabetes decreases 20:4n-6 containing species and increases 18:2n-6 and 22:6n-3 containing species, maintaining the bulk dynamic properties in the hydrophobic interior of the bilayer, but changing its biochemical properties. The different dynamic parameters were measured by fluorometry using the probes 1,6-diphenyl-1,3,5-hexatriene (DPH), (4-trimethylammonium phenyl) 6-phenyl-1,3,5 (TMA-DPH) and 6-lauroyl-2,4-dimethyl aminonaphtalene (Laurdan). In the surrounding of the hydrophobic/hydrophilic interphase lipid molecules were less ordered and tightly packed in the diabetic samples, allowing a higher mobility of incorporated water molecules. The fact that diabetes decreases highly polyunsaturated acid of n-6 family, but increases docosahexaenoic acid, indicates the necessity of re-evaluating its effect in human physiology.
Assuntos
2-Naftilamina/análogos & derivados , Diabetes Mellitus Experimental/metabolismo , Difenilexatrieno/análogos & derivados , Ácidos Graxos/metabolismo , Fosfatidilcolinas/metabolismo , 2-Naftilamina/farmacologia , Animais , Membrana Celular/química , Membrana Celular/metabolismo , Difenilexatrieno/farmacologia , Ácidos Graxos/química , Corantes Fluorescentes/farmacologia , Fluorometria , Lauratos/farmacologia , Bicamadas Lipídicas/metabolismo , Masculino , Microssomos/química , Microssomos/metabolismo , Fosfatidilcolinas/química , Ratos , Ratos WistarRESUMO
After 21 days on a diet containing 1 g% cholesterol and 0.5 g% cholic acid, rats had an increased content of cholesterol in liver microsomal lipids. In liver, both cholesterol content and delta9 desaturase activity increased, whereas delta6 and delta5 desaturase activities decreased. These changes correlated with increases in oleic, palmitoleic, and linoleic acids and decreases in arachidonic and docosahexenoic acids in total microsomal lipids. Similar fatty acid changes were found in phosphatidylcholine (PC), the principal lipid of the microsomal membrane. In PC the predominant molecular fatty acid species (67% of the total) in the control rats were 18:0/20:4, 16:0/20:4, and 16:0/18:2; and they mainly determined the contribution of PC to the biophysical and biochemical properties of the phospholipid bilayer. The cholesterol diet decreased specifically the 18:0/20:4 species, and to a lesser extent, 16:0/20:4 and 18:0/22:6. The 18:1-containing species, especially 18:1/18:2 and less so 16:0/18:1 and 18:1/20:4, were increased. A new 18:1/18:1 species appeared. The independent effects of the presence of cholesterol and change of the fatty acid composition of the phospholipid bilayer of liver microsomes on the packing were studied by fluorescence methods using 6-lauroyl-2,4-dimethylaminonaphthalene, 1,6-diphenyl-1,3,5-hexatriene and 1-(4-trimethylammonium phenyl)-6-phenyl-1,3,5-hexatriene, which test different parameters and depths of the bilayer. Data showed that the increase of cholesterol in the membrane, and not the change of the fatty acid composition of phospholipids, was the main determinant of the increased bulk packing of the bilayer. The increase of fluid oleic- and linoleic-containing species almost compensated for the drop in 20:4- and 22:6-containing molecules. But the most important effect was that the general drop in essential n-6 and n-3 polyunsaturated fatty acids meant that this endogenous source for the needs of the animal decreased.
Assuntos
Colesterol/farmacologia , Microssomos Hepáticos/química , Fosfatidilcolinas/metabolismo , Animais , Ácido Araquidônico/metabolismo , Ácido Cólico/farmacologia , Cromatografia Líquida de Alta Pressão , Dessaturase de Ácido Graxo Delta-5 , Difenilexatrieno/análogos & derivados , Difenilexatrieno/farmacologia , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos Monoinsaturados/metabolismo , Ácido Linoleico/metabolismo , Linoleoil-CoA Desaturase , Bicamadas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Modelos Teóricos , Ácido Oleico/metabolismo , Fosfolipídeos/metabolismo , Ratos , Ratos Wistar , Espectrometria de Fluorescência , Estearoil-CoA Dessaturase/metabolismo , Fatores de TempoRESUMO
The influence of a fat-free diet on the molecular species composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI) of rat liver microsomes was studied by using reversed-phase high-pressure liquid chromatography. In the three phosphoglyceride classes analyzed, the fat-free diet produced a large decrease in the 18:0/20:4n-6 species but less important changes were found in the 16:0/20:4n-6 species. In PC, the most abundant phosphoglyceride class of rat liver microsomes, the fall in the 18:0/20:4n-6 species was counterbalanced mainly by an enhancement in the 16:0/18:1n-9 species although it was not evident in PE. In PI, the decrease in the 18:0/20:4n-6 species was counterbalanced by an increase in the 18:0/20:3n-9 species. Fluorescence polarization measurements of 1,7-diphenyl-1,3,5-hexatriene in liposomes of 16:0/18:1n-9, 18:0/18:1n-9-, 16:0/20:4n-6-, and 18:0/20:4n-6-PC indicated that the change in the saturated fatty acid in the sn-1 position accompanying the replacement of 20:4n-6 by 18:1n-9 could be very important for a homeoviscous compensation, maintaining the membrane physical properties without large alterations in spite of the essential fatty acid deficiency due to the fat-free diet.
Assuntos
Dieta com Restrição de Gorduras , Ácidos Graxos/análise , Microssomos Hepáticos/química , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Fosfatidilinositóis/química , Animais , Cromatografia Líquida de Alta Pressão , Ácidos Graxos Insaturados/análise , Polarização de Fluorescência , Lipossomos , Masculino , Fosfatidilcolinas/análise , Fosfatidiletanolaminas/análise , Fosfatidilinositóis/análise , Ratos , Ratos WistarRESUMO
The fatty acid composition of muscle lipids from eadible fish from Paraná river such as Dorado (Salminus maxillosus), Boga (Leporinus affinis), Patí (Luciopimelodus pati) and Surubí (Pseudoplatistoma coruscans) was studied in order to determine their food value in relation to essential fatty acid n-3 and n-6 supply. Flesh from these fishes is relatively lean and its lipids only contain 35% to 38% saturated fatty acids. Significant amounts of n-6 polyethylenic acids, mainly linoleic, arachidonic and the n-3 acids, docosahexaenoic, docosapentaenoic, eicosapentaenoic and alpha-linolenic are found in these fishes. Patí flesh is the most abundant in n-6 acids with a value of 306 mg/100 g muscle, followed by Boga, Dorado and Surubí. A large proportion of n-3 acids is supplied by muscles of Dorado, 183 mg/100g muscle, followed by Patí, Boga and Surubí. More than 90% of the lipids that supply these acids are present in triacylglycerols in Dorado, Boga and Patí. In Surubí, triacylglycerols constitute 60% and the remaining lipids are phospholipids. Cholesterol content in flesh of fresh water fish was analyzed, and it did not exceed 4.7 micrograms/g muscle for Patí, being lower for the other species studied. Fish considered in this work represent a good dietary source of polyunsaturated fatty acids either n-6 or n-3 series for the mediterranean population in our country.
Assuntos
Dieta , Ácidos Graxos Essenciais/análise , Óleos de Peixe/análise , Valor Nutritivo , Animais , Brasil , Água Doce , HumanosRESUMO
The influence of a fat-free diet on the lipid dynamics of rat liver microsomes and liposomes of microsomal lipids was studied by using different fluorescence methods. Lifetime distribution and rotational diffusion of probes with different localization in the lipid bilayer were measured using multifrequency fluorometry. Lateral mobility was studied by measuring excimer formation of pyrenedodecanoic acid. Dipolar relaxation in the interfacial region was studied using 2-dimethyl-amino-6-lauroylnaphthalene (Laurdan). In spite of large changes in the fatty acid composition of microsomal lipids, polyunsaturated fatty acid deficiency showed no effect on the lifetime distribution and rotational mobility of 1,6-diphenyl-1,3,5-hexatriene (DPH). l-(4-(trimethylamino)phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), 2- 7- and 12-(9-anthroiloxy)stearic acids. The treatment did not change the lateral diffusion of pyrenedodecanoic acid, either. However, generalized polarization of Laurdan fluorescence was higher in polyunsaturated fatty acid deficient microsomes as compared to the polyunsaturated fatty acid sufficient ones. This effect was also observed in liposomes of the total microsomal lipids, indicating that the changes in fatty acid composition resulting from polyunsaturated fatty acid deficiency produced a small but significant decrease in the rate of dipolar relaxation in the region of the lipid polar groups of the bilayer. The absence of lipid gel phase domains in rat liver microsomes was also indicated by Laurdan fluorescence features.
Assuntos
Ácidos Graxos Essenciais/deficiência , Lipídeos de Membrana/química , Microssomos Hepáticos/química , Animais , Fenômenos Biofísicos , Biofísica , Transferência de Energia , Polarização de Fluorescência , Corantes Fluorescentes , Bicamadas Lipídicas/química , Lipossomos/química , Masculino , Ratos , Ratos Wistar , Espectrometria de FluorescênciaRESUMO
PIP: "Studies on Italian immigration in Argentina have shown that approaches at the provincial level add to our understanding of migration patterns and processes. The case study of urban immigrants from a region in central Italy shows similarities and differences with Italian immigration in Buenos Aires in general. Residential patterns and occupations are analyzed through a combination of mutual association membership registers and shipping lists; the linkage of available sources showed, at least for these immigrants, a considerable gap between arrival and entry in a mutual aid society, a fact which reduces the importance of the voluntary associations in assisting recent immigrants to obtain a job." (EXCERPT)^ieng
Assuntos
Aculturação , Emigração e Imigração , Emprego , Ocupações , População Urbana , América , Argentina , Demografia , Países Desenvolvidos , Países em Desenvolvimento , Economia , Europa (Continente) , Mão de Obra em Saúde , Itália , América Latina , População , Características da População , Dinâmica Populacional , Preconceito , América do Sul , MigrantesRESUMO
The effect of essential fatty acid deficiency on the structural and dynamic properties of the lipid matrix of rat liver microsomes and erythrocyte membranes was studied. The rate and range of the rotational mobility of 1,6-diphenyl-1,3,5-hexatriene and 2-, 7-, and 12-(9-anthroyloxy)stearate probes in the native membranes and in lipid vesicles prepared with the total lipid extracts of these membranes were evaluated by using differential polarized phase fluorometry. For the anthroyloxystearate probes, two modes of rotation (in and out of the plane of the aromatic anthracene ring) were partially resolved by measuring at different excitation wavelengths. The fat-free diet produces important changes in the fatty acid composition of the different glycerophospholipid classes without affecting the total double-bond number, the relative contents of cholesterol, phospholipid, and protein, and the glycerophospholipid class distribution. The principal changes, more pronounced in liver microsomes than in erythrocytes, are: an increase in nonessential monoene and triene (18:1n-9 and 20:3n-9) and a decrease in essential diene (18:2n-6) and tetraene (20:4n-6). These changes modify the double-bond distribution as a function of the distance from the interphase toward the bilayer interior, with a significant deficit (15% in erythrocytes and 30% in liver microsomes) in the double-bond density in the intermediate region of the membrane leaflet, corresponding to the carbon number 11-12 of an extended saturated acyl chain, and where the 12-anthroyloxystearate probe is located. In spite of the changes in fatty acid composition and double-bond distribution, with the only exception of a slight increase (about 15%) in the "out of the plane" rotation rate of the 7-(9-anthroyloxy)stearate probe in the erythrocyte lipid vesicles, no other significant change is observed. Thus, the changes in fatty acid composition would take place in such a way that at least the average structural and viscotropic properties of the lipid phase of the membrane, sensed by these probes, would be almost exactly compensated.