The non-LTR retrotransposons of Entamoeba histolytica: genomic organization and biology

Although erythrophagocytosis by various species of Entamoeba is a well known phenomenon this has not yet been studied in detail at the ultrastructural level. The present work deals with the description of the incorporation process of erythrocytes by trophozoites of E. histolytica. For this study, trophozoites of E. histolytica, HK-9:NIH strain cultured in axenic conditions and washed human erythrocytes were placed on a hot plate at 37°C in physiological saline solution. After 5 minutes, 2.5% glutarldehyde was added and the samples were processed according to conventional techniques for electron microscopy.Based upon light microscopy studies on living trophozoites in contact with erythrocytes, it seems that erythrophagocytosis only takes place in one pole of the parasite.

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Scanning electron microscopy of erythrophagocytosis by Entamoeba histolytica trophozoites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012480x ◽

1992 ◽

Vol 50 (1) ◽

pp. 880-881

Author(s):

Victor Tsutsumi ◽

Adolfo Martinez-Palomo ◽

Kyuichi Tanikawa

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Red Blood Cells ◽

Entamoeba Histolytica ◽

Causative Agent ◽

Blood Cells ◽

Protozoan Parasite ◽

Complex Phenomenon ◽

Great Capacity ◽

Scanning Electron

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis in man. The trophozoite or motile form is a highly dynamic and pleomorphic cell with a great capacity to destroy tissues. Moreover, the parasite has the singular ability to phagocytize a variety of different live or death cells. Phagocytosis of red blood cells by E. histolytica trophozoites is a complex phenomenon related with amebic pathogenicity and nutrition.

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Localization of the Br Polymorphism on a 144 bp Exon of the GPIa Gene and Its Application in Platelet DNA Typing

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642498 ◽

1994 ◽

Vol 71 (05) ◽

pp. 651-654 ◽

Cited By ~ 50

Author(s):

Rainer Kalb ◽

Sentot Santoso ◽

Katja Unkelbach ◽

Volker Kiefel ◽

Christian Mueller-Eckhardt

Keyword(s):

Genomic Organization ◽

Fragment Length Polymorphism ◽

Human Platelet ◽

Dna Typing ◽

Rflp Analysis ◽

Serological Typing ◽

Allele Specific ◽

Polymerase Chain ◽

Alloimmune Thrombocytopenia ◽

Rflp Typing

SummaryAlloimmunization against the human platelet alloantigen system Br (HPA-5) is the second most common cause of neonatal alloimmune thrombocytopenia (NAIT) in Caucasian populations. We have recently shown that a single base polymorphism at position 1648 on platelet mRNA coding for GPIa results in an aminoacid substitution at position 505 on the mature GPIa which is associated with the two serological defined Br phenotypes.Since DNA-typing of platelet alloantigens offers possibilities for useful clinical applications, we designed genomic DNA-based restriction fragment length polymorphism (RFLP) typing for Br alloantigens. To establish this technique we analyzed the genomic organization of GPIa adjacent to the polymorphic base. Using the polymerase chain reaction (PCR) of blood cell DNA we have identified two introns (approximately 1.7 and 1.9 kb) flanking a 144 bp coding sequence of the GPIa gene encompassing the polymorphic base 1648. Based on the in- tron sequence, a PCR primer was constructed to amplify a 274 bp fragment which was used for allele-specific RFLP to determine the Br genotypes. The results of RFLP analysis using Mnll endonuclease obtained from 15 donors (2 Br37*, 2 Br^ and 11 Brb/b) correlate perfectly with serological typing by monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay.

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