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Biomedical subjects

E Willaert

Publications and source records attributed to E Willaert.

12 recordsLinked to original sources
PubMed1978

Acanthamoeba royreba sp. n. from a human tumor cell culture.

A new species of Acanthamoeba was isolated from a culture of an established line of human choriocarcinoma cells. The identification of this strain, originally called the Oak Ridge strain, and the establishment of a new species for it were based on morphologic, serologic, and immunochemical studies. In general, the structure of the trophozoite did not differ significantly from that of other species of Acanthamoeba, except that a body which more closely resembled a centriole than material described previously as centriolar satellites was observed in trophozoites examined with the electron microscope. The dimensions of the trophozoite were the smallest among the species of Acanthamoeba. The cyst was typical of the genus, but differed from those of other species by its smaller size and the presence of numerous ostioles. Studies of the Oak Ridge strain by immunofluorescence using antisera developed against the isolate and Acanthamoeba culbertsoni, A. castellanii, A. polyphaga, A. rhysodes, A. astronyxis, and A. palestinensis revealed the antigenic uniqueness of the Oak Ridge strain. It was demonstrated by immunoelectrophoretic analyses of the soluble proteins of the Oak Ridge strain that shared approximately 1/2 of its antigenic structure with A. castellanii and A. culbertsoni. The antigenic differences of the isolate from other species of Acanthamoeba were deduced from comparison of the antigenic constitution of these species and the Oak Ridge strain with A. culbertsoni and A. castellanii. Although the strain was initially recognized by its cytopathogenicity for cultures, it did not produce acute infections in mice after intranasal inoculation of 1 X 10(4) ameba/mouse. The foregoing results constituted the basis for the establishment of the Oak Ridge strain as a new species, A. royreba sp. n., in the genus Acanthamoeba.

Amoeba↗
PubMed1978

Retrospective identification of Acanthamoeba culbertsoni in a case of amoebic meningoencephalitis.

Acanthamoeba culbertsoni was identified retrospectively in a case of amoebic meningoencephalitis, previously reported by Jager and Stamm (Lancet, 2, 1343, 1972). This is the second report of this species causing secondary infection in man. Positive results were obtained only with anti-A. culbertsoni sera when the brain sections were stained by the indirect immunofluorescence antibody test with various antisera produced against different Acanthamoeba species. Antiserum raised against purified plasma membranes of A. culbertsoni showed once more its highly specific diagnostic value.

Adult↗
PubMed1977

Meningoencephalitis due to Acanthamoeba SP. Pathogenesis and clinico-pathological study.

Amebic Meningoencephalitis (AM) and Primary Amebic Meningoencephalitis (PAM) are infectious diseases essentially confined to the Central Nervous System (CNS) and caused by free-living amebas of the genus Acanthamoeba (A.) and Naegleria (N.) respectively. AM due to A. sp. (Acanthamoeba castellanii and Acanthamoeba culbertsoni) have been reported in chronically ill debilitated individuals, some of them under immunosuppressive therapy, or in immunologically impaired patients without a history of recent swimming in contrast to cases due to N. sp. which usually occurs in healthy, young individuals with a recent history of swimming in man-made lakes or heated swimming pools. AM due to A.sp. is characterized by a subacute or chronic granulomatous meningoencephalitis involving mainly the midbrain, basal areas of the temporal and occipital lobes and posterior fossa structures. CNS lesions in AM are perhaps secondary and the portal of entry in humans is probably from the lower respiratory tract, genitourinary system or skin reaching the CNS by hematogenous spread. The predominant host reaction is usually composed of lymphocytes, plasma cells, monocytes and multinucleated foreign body giant cells. Necrosis is moderate and hemorrhage scant or absent. Cysts as well as trophozoites may be seen within the CNS lesions. PAM is due to Naegleria fowleri and is characterized by an hemorrhagic necrotizing meningoencephalities with an acute inflammatory response. Only trophozoites are found in lesions. The portal of entry is through the olfactory neuroepithelium. CNS tissues fixed in formalin may be used for further identification and taxonomical classification of the causative protoza using immunofluorescent antibody techniques (IFAT) and electron microscopic methods.

Amebiasis↗
PubMed1977

Isolation of the etiological agent of primary amoebic meningoencephalitis from artifically heated waters.

To determine whether artificial heating of water by power plant discharges facilitates proliferation of the pathogenic free-living amoebae that cause primary amoebic meningoencephalitis, water samples (250 ml) were taken from discharges within 3,000 feet (ca. 914.4 m) of power plants and were processed for amoeba culture. Pathogenic Naegleria fowleri grew out of water samples from two of five lakes and rivers in Florida and from one of eight man-made lakes in Texas. Pathogenic N. fowleri did not grow from water samples taken from cooling towers and control lakes, the latter of which had no associated power plants. The identification of N. fowleri was confirmed by pathogenicity in mice and by indirect immunofluorescence analyses, by using a specific antiserum.

Amoeba↗
PubMed1976

Indirect immunofluorescent identification of Acanthamoeba causing meningoencephalitis.

The majority of primary amoebic meningoencephalitis cases in man have been caused by Naegleria, although three new cases have been identified due to Acanthamoeba. These cases showed a somewhat chronic course and death occurred 2 to 6 weeks after onset. The etiological agent in two cases was identified as belonging to the group of A. castellanii and the third case was identified as due to A. culbertsoni. The identification was performed post-mortem.

Adult↗
PubMed1976

Immunoassays of Acanthamoeba castellanii plasma membranes. Preliminary results.

To facilitate future diagnosis of Acanthamoeba infections in man, studies have been initiated to elicit antibodies to purified membranes from Acanthamoeba species. Specifically in this communication, preliminary results are reported on A. castellanii. Immunoprecipitation and immunofluorescent analyses suggest that the membrane antisera may allow specific identification at the species level and possibly strain identification.

Amebiasis↗