Amoebiasis
(Diagnosis,
Diagnostics, Immunodiagnosis, Immunodiagnostics, Vaccines & Drugs)
Abstracts
1559. Zhang Z. Wang L. Seydel KB. Li E.
Ankri S. Mirelman D. Stanley SL Jr. Entamoeba histolytica
cysteine proteinases with interleukin-1 beta converting enzyme (ICE) activity
cause intestinal inflammation and tissue damage in amoebiasis. Molecular
Microbiology. 37(3):542-8, 2000 Aug.
Abstract
The protozoan parasite
Entamoeba histolytica causes intestinal inflammation and ulceration. Amoebic
trophozoites activate the transcription factor NF-kappa B in human intestinal
epithelial cells, initiating an inflammatory response programme with resultant
damage to the intestinal tissue. Amoebic cysteine proteinases have been
proposed as important virulence factors for amoebiasis. To test the role of
amoebic cysteine proteinases in the pathogenesis of amoebic colitis, human intestinal
xenografts in SCID mice were infected with E. histolytica trophozoites
expressing an antisense message to ehcp5. The cysteine proteinase-deficient amoeba failed to induce
intestinal epithelial cell production of the inflammatory cytokines interleukin
(IL)-1B and IL-8, and caused
significantly less gut inflammation and damage to the intestinal permeability barrier. The critical role of
amoebic cysteine proteinases in human
gut inflammation and tissue damage may be explained by our discovery that amoebic cysteine proteinases possess
IL-1B converting enzyme (ICE) activity.
This ICE activity could contribute to intestinal inflammation by activating human pIL-1B released by damaged
intestinal cells. These results demonstrate for the first time that amoebic
cysteine proteinases are a key virulence factor in amoebic colitis, and provide
a novel mechanism for their activity.
2073. Sharma P.
Sharma JD. A review of plant species assessed in vitro for antiamoebic
activity or both antiamoebic and
antiplasmodial properties. [Review] [60 refs]Phytotherapy Research. 15(1):1-17, 2001 Feb.
Abstract
The resurgence of the protozoal diseases amoebiasis and malaria has been
known to occur, from time to time, in endemic and epidemic proportions all over
the world. Furthermore, the import of these individual pathogens to other areas
from tropical regions encourages these protozoal diseases to occur on a global
scale with considerable associated mortality and morbidity. From time immemorial, the cure of these diseases has
been attempted with the use of traditional plant products, derived from
such species as are available within
local habitats and ecosystems, and dependent on their host community for their
conservation. Scientific validation and in vitro investigation, continues to be
an important requirement for drug development, particularly with the emergence
of resistance and cross resistance to some standard drugs used in such
protozoal diseases. This paper provides a comparative compilation of the various studies reported between 1982 and
1999, on plants with antiamoebic activities and those which possess both
antiamoebic and antiplasmodial
activities. The results suggest that it is advisable to increase efforts
towards the conservation of such plants, in order to retain their economic and
therapeutic significance. Copyright 2001 John Wiley & Sons, Ltd.
[References: 60]
2074. Zindrou S.
Orozco E. Linder E. Tellez A.
Bjorkman A. Specific detection of Entamoeba histolytica DNA by hemolysin
gene targeted PCR. Acta Tropica. 78(2):117-25, 2001 Feb 23.
Abstract
Diagnostic differentiation of
pathogenic Entamoeba histolytica from non-pathogenic Entamoeba dispar is of
great clinical importance. We have developed and evaluated a new polymerase
chain reaction (PCR) assay (haemo-PCR) based on the novel E. histolytica
hemolysin gene HLY6. The specificity of this assay was confirmed by analyzing
different Entamoeba species, faeces samples, human and bacterial DNA, and
digestion of amplification products with appropriate restriction enzymes. The
sensitivity was confirmed by serial dilutions of E. histolytica HM-1:IMSS DNA
in the excess of human DNA. Totally, 45 clinical samples were analyzed by the
haemo-PCR assay including amoebic liver abscess (ALA) fluids from 23 patients
suspected for amoebiasis, four faeces samples containing E. histolytica and E.
dispar, and positive and negative controls. The results were compared with
those obtained with PCRs for cystein-rich surface protein (P30) and small
subunit ribosomal RNA (ssu rRNA) genes. The haemo-PCR gave a positive result in
18 (89%) ALA fluids compared with 14 (77%) and five (28%) by PCR for p30, and
ssu rRNA, respectively. PCR products were obtained only from specimens
containing E. histolytica DNA. The haemo-PCR assay was therefore found to be a
valuable diagnostic tool for identification of E. histolytica infections both
in faeces and ALA samples.
2613. Sharma
D. Patel LK. Vaidya VV. Amoeboma of ascending colon with multiple amoebic
liver abscesses. Journal of the Association of Physicians of India. 49:579-80, 2001 May.
Abstract
A case of amoeboma of the ascending colon with multiple amoebic liver
abscess is being presented; which was mistakenly diagnosed as carcinoma of
ascending colon with multiple secondaries in liver. Awareness of this
previously unreported association is important because it adds to our knowledge
of the spectrum of intestinal amoebiasis.