RESUMO
The cyst of Entamoeba histolytica is responsible for amebiasis infection. However, no axenic in vitro system exists that promotes mass encystation for studying this process of this human-infecting parasite. Cyst-like structures of E. histolytica obtained in this work were induced using TYI-S-33 media in combination with enterobacterias Escherichia coli and Enterococcus faecalis conditioned media, high CO2 tension and histamine. Cyst-like structures showed the same characteristics of a typical E. histolytica cyst: aggregation, resistance to 0.15% sarcosyl for 10 min, high signal of fluorescence under UV light when stained with 10% calcofluor M2r and the surface topology showed a wrinkled wall. In addition these structures are multinucleated with condensed chromatin attached to nuclear membrane, contain big vacuoles and ribonucleoproteic helices in the cytoplasm and also present a thin cell wall. Last all characteristics are all the same as a typical of E. histolytica cyst.
Assuntos
Entamoeba histolytica/fisiologia , Animais , Meios de Cultura , Entamoeba histolytica/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microscopia de FluorescênciaRESUMO
The current media for axenic cultivation of Entamoeba histolytica and Entamoeba invadens are supplemented with bovine or equine serum, which provides several essential nutrients to amoebas. Serum has also been considered an essential component in encystation media for E. invadens. A substitute of serum, PACSR has been described as an alternative for growth of E. histolytica and also maintains growth of E. invadens. When PACSR was used instead of serum for encystation of E. invadens the efficiency was the same as for serum. Our present data show that PACSR can support the growth and induction of encystation of E. invadens strain IP-1.
Assuntos
Aminoácidos/fisiologia , Meios de Cultura Livres de Soro/química , Entamoeba/fisiologia , Lipídeos/fisiologia , Animais , Entamoeba/crescimento & desenvolvimento , Entamoeba/ultraestrutura , Microscopia Eletrônica , Microscopia de FluorescênciaAssuntos
Cafeína/farmacologia , Diferenciação Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Entamoeba/efeitos dos fármacos , Epinefrina/farmacologia , Fluoreto de Sódio/farmacologia , Teofilina/farmacologia , Animais , Entamoeba/citologia , Entamoeba/crescimento & desenvolvimento , Entamoeba/metabolismoRESUMO
After an exponential phase of growth, HK9 strain amebas, kept in the axenic medium PEHPS, spontaneously acquire a form morphologically similar to various natural cysts, as well as a resistance to hypotonic shock, due to the effect of a wall, partially composed of polysaccharides. The number of differentiated amebas increases gradually, although their viability diminishes, in function of the incubation time. On the ninth day, 96% of the population is made up of these cells, although only 6% are viable. The ultramicroscopic structure of the great majority of differentiated amebas corresponds to that of immature cysts. These, and the PEHPS medium, constitute a good model for a characterization of the start of the differentiation of E. histolytica, and open the opportunity of obtaining in axenic conditions, massive cultures of mature cysts.
Assuntos
Entamoeba histolytica/ultraestrutura , Vida Livre de Germes/fisiologia , Animais , Meios de Cultura , Entamoeba histolytica/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Microscopia de Contraste de Fase , Pressão OsmóticaRESUMO
Since the TPS-1 medium description, by Diamond, for axenic cultivation of Entamoeba histolytica trophozoites, a spectacular advance in this parasite biology knowledge has been occurred. Recently we described a new medium, called PEHPS, which is as reliable as those of current use, and besides offers a more stable final density. From this latter, we developed, a new simpler medium, after being evaluated the specific contribution of several components of PEHPS. Yields as high as those obtained with the original medium were obtained after the following modifications, incorporated in the new medium formula: Osmolarity 318 +/- 6 mOsm/Kg, pH 6.8, redox potential -130 mV, regulated only with 1.0 g/l of ascorbic acid, glucose 3.75 g/l, instead of the original PEHPS characteristics, which are the following: Osmolarity 340 +/- 42 mOsm/KG, pH 7.0, regulated with both cysteine and ascorbic acid and 6.0 g/l of glucose. As the new medium supplementation with vitamins did not result in significative differences with respect to the non supplemented medium, we eliminated all of these from the final formula.
Assuntos
Meios de Cultura , Entamoeba histolytica/crescimento & desenvolvimento , Parasitologia/métodos , Animais , Meios de Cultura/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Glucose/farmacologia , Concentração de Íons de Hidrogênio , Concentração Osmolar , Oxirredução , Vitaminas/farmacologiaRESUMO
In order to estimate the frequency of G6PD deficiency in the icteric population of the Monterrey metropolitan área (MMA), in the state of Nuevo León, there were studied 829 newborn males were studied. It was found that 13 subjects were deficient of this enzyme, that is equivalent to a frequency of 1.57% and when this frequency was compared with the one that was found an a previous study in a random sample of newborn males (0.66%) no statistical difference was observed, but it was estimated that the icteric newborn males have a relative risk of 2.34 times higher than the population in general to be a G6PD deficient, and this fact suggests the necessity to establish this screening test as a routine for all icteric newborn males, in order to have an opportune detection and an appropriate counselling.