Darstellung von Mikrofilamenten im Cytoplasma von Entamoeba histolytica

Michel, R.; Schupp, E.

doi:10.1007/bf00328883

Cited by 4 publications

(2 citation statements)

References 33 publications

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“…Possibly, the thin microfilaments of Naegleria are membrane bound as they are in Acanthamoeba (Pollard and Korn, 1972) and in Chaos (Comly, 1973). Bundles of colaterally aggregated thin microfilaments positioned near the plasma membrane occur in Naegleria as well as in a variety of other amoebae (Comly, 1973 ;Eckert and McGee-Russell, 1973 ; Haberey, • 39,250, m mitochondria, n nucleolus, nm nuclear menbrane, pm plasma membrane 1973; Nachmias, 1964Nachmias, , 1968Pollard and Ito, 1970;Michel and Schupp, 1974;Wohlman and Allen, 1968). The thick microfilaments of Naegleria are randomly oriented and do not appear to be attached to the plasma membrane, similar to those of Amoeba proteus (Pollard and Ito, 1970).…”

Section: Discussionmentioning

confidence: 97%

“…Microfilaments, particularly thick microfilaments are labile and glutaraldehyde is an essential fixative in their preparation for the electron microscope (Nachmias, 1968). Prolonged uranyl acetate staining enhances amoeboid microfilaments for visualization under the electron microscope (Michel and Schupp, 1974). A combination of extended contact with glutaraldehyde and double staining with uranyl acetate in pellet and in section has preserved and enhanced Naegleria microfilaments.…”

Section: Discussionmentioning

confidence: 99%

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Microfilaments inNaegleria fowleri amoebae

1976

Z. F. Parasitenkunde

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Examination by electron microscopy has revealed 2 types of microfilament in the cytoplasm of 3 strains of axenically grown Naegleria fowleri amoebae. Thin, actin-like microfilaments 5-7 nm in diameter are randomly oriented in the nonmotile amoebae, and are concentrated near the plasma membrane. In the actively motile amoebae these microfilaments aggregate to form colateral bundles in close proximity to the plasma membrane. Thick, myosin-like microfilaments 17-19 nm in diameter also occur in the amoebae cytoplasm. The significance of these 2 kinds of microfilament in amoeboid motion is discussed.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Microfilaments inNaegleria fowleri amoebae

1976

Z. F. Parasitenkunde

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Structural changes on Entamoeba histolytica trophozoites after cryopreservation in liquid nitrogen

Raether¹,

Schupp²,

Michel³

et al. 1977

Z. Parasitenk.

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Trophozoites of Entamoeba histolytica cultures which had been deep-frozen in the presence of 5% DMSO, along with untreated cells and cells treated with DMSO (5%), were examined for fine-structural changes. After deep-freezing in liquid nitrogen only a few amoebae exhibited normal nuclear and cytoplasmic structure. One frequently observed but unspecific finding pertaining to recovered cells is the separation of the cytoplasm into large vacuolated (coarse-granular) and electron-optically fine-granular (hyaline) zones. The glycogen which normally lies in the cytoplasm is always eluted. In many cases numerous short RNP helices are scattered unevenly in the vesicular plasma, but they are also found in larger masses adjacent to the membranes of still intact and already damaged nuclei. Moderately damaged nuclei have a poorly folded membrane and their chromatin is markedly denatured. More heavily damaged nuclei have a membrane which has partly fibrillated or ruptured and then formed conspicuous folds, where the nuclear membrane has ruptured nucleoplasmic remnants of chromatin and button-like bodies appear to pour into the surrounding cytoplasm. The final destruction of the cell is marked by coalescing autolytic zones, first in the vacuolated and later in the fine-granular cytoplasm. Finally only remnants of the nuclear membrane and of the membranes of numerous vacuoles remain. It is assumed that most of the changes in the cytoplasm are of a secondary nature and are caused by the early functional disturbance of the nucleus.

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Fibrill�re und tubul�re Feinstrukturen im Cytoplasma von Entamoeba histolytica

Michel¹,

Schupp²

1975

Z. F. Parasitenkunde

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The electron-microscopical study of conventional fixed and contrasted Entamoeba histolytica-trophozoites from Diamonds monoxenic TTY-medium revealed "thick fibrils" in the vesicular cytoplasm of the parasites. They are 9-14 nm in diameter and are therefore considered to be myosin-like filaments, that are spread mainly in the tail or the uroid of the moving ameba. No association with microfilaments (MF) or other organelles could be observed. During the same investigation microtubules (MT) of variable length are described having a diameter of 35 nm, surrounded by a 19-25 nm wide capsule. They are distributed singly or in bundles with a maximal diameter of 350 nm. Some of the MT were coiled up to a helical shape.

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Darstellung von Mikrofilamenten im Cytoplasma von Entamoeba histolytica

Cited by 4 publications

References 33 publications

Microfilaments inNaegleria fowleri amoebae

Microfilaments inNaegleria fowleri amoebae

Structural changes on Entamoeba histolytica trophozoites after cryopreservation in liquid nitrogen

Fibrill�re und tubul�re Feinstrukturen im Cytoplasma von Entamoeba histolytica

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