PubMed Health⌕ Search

Biomedical subjects

A Aust-Kettis

Publications and source records attributed to A Aust-Kettis.

15 recordsLinked to original sources
PubMed1999

High frequency of gastrointestinal parasites in refugees and asylum seekers upon arrival in Sweden.

The results of routine screening for intestinal parasites in 1377 refugees and asylum seekers within 2 weeks of arrival in Sweden showed that protozoa, mainly Giardia intestinalis, were found in 235/1377 (17%) and helminths, mainly hookworms, in 264/1377 (19%). Intestinal parasites were more frequently recovered in refugees coming from South East Asia, Africa and Latin America (infection rates 48%, 43% and 42%, respectively) than in those from Eastern Europe (22%) and the Middle East (32%). Refugees who reported gastrointestinal symptoms were less often infected than those without symptoms (p < 0.001). Of the European refugees, 127 came from Bosnia. A high rate of hookworms was found in this group (15%), suggesting that hookworms may also be transmitted in temperate areas under special conditions. We thus identified relatively high rates of pathogens in all groups of refugees. Screening may therefore be recommended, though more for the benefit of refugees than for the prevention of further spread of the infections.

Adolescent↗
PubMed1998

Microsporidia in duodenal biopsies from 72 HIV-infected patients with abdominal complaints.

In order to evaluate the capacity of routine histological examination to detect microsporidiosis, a retrospective study was performed on 72 duodenal biopsies from 72 HIV-infected patients with upper abdominal symptoms of unknown cause. Two light microscopic cytological staining techniques, modified trichrome stain and the fluorochrome Calcofluor, were used. Two cases of microsporidiosis were detected among the 20 patients with prolonged diarrhoea of unknown origin in whom no etiological agent had been demonstrated by stool examination, mycobacterial and cytomegalovirus culture of biopsies, and histological routine staining of duodenal biopsies. The calculated confidence interval of 3-30% corresponds to the prevalence of intestinal microsporidiosis in HIV patients with prolonged diarrhoea in various parts of the world. The findings motivate attempts to identify microsporidia using special cytological staining methods. Improved methods of species identification are needed to aid in the choice of chemotherapy.

Animals↗
PubMed1990

Antibodies against Entamoeba histolytica antigens in sera from individuals with amoebiasis of different localization.

The over-all contents and relative component composition of Entamoeba histolytica antigens in abscess fluids and in extracts of cultured amoebae, strain NIH 200, were studied by antigen-catching EIA, counterimmunoelectrophoresis (CIE) and immunoblotting techniques. The antigen contents of liver abscess fluid were determined semiquantitatively by the antigen-catching EIA in four cases. In CIE against a standard "diagnostic" extract of cultured amoebae, sera from cases of acute amoebic liver abscess gave 4-5 precipitation lines while sera from cases of intestinal amoebiasis gave at most 3 lines. In immunoblotting tests with the same antigen, intestinal cases gave blotting bands in the intermediate molecular weight range (25-99 kD) while acute abscess cases, in addition, gave bands in the high (100-175 kD) and low (= less than 25 kD) molecular weight range. These serological differences between clinical forms of amoebiasis were more definite when using amoeba abscess fluid as antigen. Amoeba antigens in high concentrations could be demonstrated in amoeba abscess fluids with all methods employed. In immunoblotting experiments abscess fluids generally gave stronger and more numerous bands with anti-amoeba antibody-containing sera than did the standard "diagnostic" antigen from cultured amoebae. Especially the abscess fluids gave with sera from acute abscess cases a number of prominent bands in the low molecular weight range (less than 25 kD). The experiments in this study were performed with crude amoebic extracts, which contained a multitudes of antigenic components and a still greater diversity of antigenically inert proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Diphtheria in Stockholm, with a theory concerning transmission.

Since 1984, diphtheria has been diagnosed in Sweden, mainly among men abusing alcohol. During the first half of 1986, eight cases of diphtheria were discovered in the city of Stockholm. The first three were among men abusing alcohol. The following five cases had no connection with them. These five persons were employed in two companies housed in the same building. The only connection between them was that they ate their lunch at the same restaurant. One alcohol-abusing man had worked temporarily in the kitchen of this restaurant during the week before the five cases of diphtheria arose. He knew one of the first three patients well. A throat swab taken from him a month after the five cases had been diagnosed was negative. It was suspected however, that this man might have been a carrier of Corynebacterium diphtheriae during the week that he worked in the kitchen. Tests for C. diphtheriae antitoxin revealed that the kitchen staff had high antitoxin titres although they lacked a history of basic immunisation. Even so, C. diphtheriae could not be isolated from their throats and it has not been possible to establish the mode of transmission. The most reasonable theory of transmission is that the organism was introduced into the kitchen by the man employed there temporarily and that it was spread by food served in the restaurant. This theory has not been proved but is discussed in order to facilitate future investigations of a similar outbreak.

Adult↗
PubMed1986

Entamoeba histolytica: effect of growth conditions and bacterial associates on isoenzyme patterns and virulence.

In xenic culture, isolates of Entamoeba histolytica from asymptomatic carriers are characterized, with rare exception, by possession of a nonpathogenic zymodeme. During the process of axenizing such an isolate, strain CDC:0784:4, a change in the pattern of the isoenzymes from nonpathogenic zymodeme I to pathogenic zymodeme II was observed 40 days after the amebae had been transferred from a medium for xenic cultivation to one used for axenic cultivation, but before axenization of the amebae had actually occurred. Axenization was accomplished by feeding the amebae lethally irradiated bacteria while suppressing and finally eradicating with antibiotics the bacterial flora accompanying the amebae in the original xenic culture. The change in zymodeme was accompanied by a change in virulence as evidenced by the ability of the amebae to produce hepatic abscesses in hamsters and to destroy monolayers of tissue culture cells. Two explanations are offered for the observed changes in zymodeme and virulence: a zymodeme is not a stable inherent property of the ameba. Alternatively, the original isolate consisted of two zymodeme populations and the conditions of growth selected for one or the other of the populations. In either case, our results suggest that the finding of a particular zymodeme in a culture of E. histolytica isolated from an asymptomatic carrier of the parasite cannot be used to predict a clinical condition or serve as a basis for the recommendation of therapy.

Amebiasis↗
PubMed1983

Migration of Entamoeba histolytica under agarose.

A procedure for visualizing and quantifying motility of Entamoeba histolytica by migration under agarose is described. Agarose suspended in tissue culture medium 199 supplemented with bovine albumin was poured into plastic dishes and allowed to harden. Six pairs of wells were cut out in a circular configuration. To the inner wells a suspension of E. histolytica in Eagle's Medium (24 X 10(6) cells/ml) was added, and to the outer wells a chemoattractant or the control medium. After overnight incubation at 37 degrees C, the amebae were fixed and stained. The chemotactic and spontaneous migrations were measured in an enlarging projector. Escherichia coli filtrates, suspensions of intact and lysed erythrocytes, and the complement factor C5a acted as good chemoattractants. Both the random and chemotactic motility were correlated to the time of the incubation. Cytochalasin B effected a dose-related inhibition of both chemotactic and random migration, while colchicine caused a decrease of the chemotaxis only. The reproducibility of the method, measured by 10 intra-assay tests, was good. Thus, the described method can be useful for comparative determinations of the motility of different ameba populations. Furthermore, different factors affecting the motility of amebae can be studied.

Chemotaxis↗
PubMed1981

Dynamics of the interaction between Entamoeba histolytica and components of the immune response. III. Fate of antibodies after binding to the cell surface.

Binding to the surface of living E. histolytica trophozoites of 125I-labelled anti-amoeba antibodies or of such antibodies and antiglobulin resulted in a rapid disappearance of the antibody into the medium. This disappearance consisted of a rapid temperature-independent and a subsequent slow temperature-dependent phase. The disappearance of antibody from fixed trophozoites merely consisted of a temperature-independent rapid phase whereas no slow phase was observed. The magnitude of the rapid phase of antibody disappearance was virtually the same in living and fixed cells. During culture of living trophozoites for 4 h the amount of iodine-labelled material sedimenting lighter than monomeric IgG increased from 2% to 14% of all labelled material in the case of the single antibody layer. The corresponding values for the double layer were 2% and 32%. Of the material lighter than IgG, 10% of that in the single layer and 26% of that in the double layer were detected in the medium. Thus, during the 4-h culture period 25% of the originally amoeba-bound single layer of antibody probably disappeared from the cells not complexed with antigen, 27% disappeared as complexes heavier than IgG, 10% disappeared as material lighter than IgG, and 38% persisted on or within the cells. The corresponding values for the double layer of antibody were 10%, 30%, 26% and 34%.

Animals↗
PubMed1981

Antibodies to heat-labile Escherichia coli enterotoxins in human milk and sera. A study of Ethiopian and Swedish mothers and their children.

Maternal serum and cord blood from 50 Ethiopian, 10 Costa Rican and 20 Swedish newly delivered mothers and their babies was examined for the presence of antibodies against heat labile (LT) enterotoxin from a human strain of E. coli. 96% of the Ethiopian, 80% of the Costa Rican and 30% of the Swedish mothers and infants had detectable antibody levels. The titres were significantly higher in the Ethiopian material. Furthermore, antibody titres to E. coli enterotoxin were determined in breast milk collected from Ethiopian mothers at 48 h and at 1 month after delivery. One third of these mothers had detectable levels of antibodies in samples from early lactation. Experiments performed with LT enterotoxin from another human and with LT from a porcine E. coli strain confirmed the results. Neutralization tests with cholera enterotoxin as antigen were all negative in sera and milk samples from all these groups. The material has been collected in three different geographical areas which are nonendemic for cholera.

Antibodies, Bacterial↗
PubMed1980

Dynamics of the interaction between Entamoeba histolytica and components of the immune response.

Trophozoites of Entamoeba histolytica redistributed specific antibodies reacting to antigens on their surface. The presence of a second layer of anti-antibodies enhanced the redistribution of anti-amoeba antibodies but was not a prerequisite for this process. Microfluorometric measurements of the fluorescence intensity in different areas of the cell surface provided objective evidence for the antibody-induced redistribution. In order to distinguish surface-bound and internalized anti-amoeba antibodies, the trophozoites were fixed in PFA. This fixation made the cells impermeable to antibodies. Thus, after fixation in PFA at different times during the redistribution process surface-bound anti-amoeba antibodies labelled with one fluorochrome could be detected with anti-bodies labelled with another fluorochrome. This approach showed that the amoeba, in addition to the redistribution, also internalized anti-amoeba antibodies.

Animals↗
PubMed1978

Dynamics of the interaction between Entamoeba histolytica and components of the immune response. I. Capping and endocytosis; influence of inhibiting and accelerating factors; variation of the expression of surface antigens.

The possible implications of cell membrane dynamics in the host--parasite relationship has been studied. Entamoeba histolytica rapidly redistributed and internalized antibodies and Con A bound to its surface. The process was dependent on temperature, cell metabolism and changes of pH in the environment. Phagocytizing amoebae displayed a higher rate of membrane perturbations, which were similarly affected by temperature, cell metabolism and pH variations. Cytochalasin B partially inhibited the redistribution whereas colchicine did not. Colchicine in combination with Cytochalasin B augmented the inhibitory effect of Cytochalasin B alone. The expression of antigens at the surface of the amoeba showed cyclic fluctuations during cell growth.

Antigens↗
PubMed1976

Enterotoxin-producing bacteria and parasites in stools of Ethiopian children with diarrhoeal disease.

Enterotoxinogenic bacteria were isolated from 131 (37%) of 354 Ethiopian infants and children with acute gastrointestinal symptoms. Only one of these isolates belonged to the classical enteropathogenic serotypes of Esch. coli. Two colonies from each patient were isolated and tested for production of enterotoxin by the rabbit ileal loop test, the rabbit skin test, and an adrenal cell assay. However, only 38% of the isolated enterotoxinogenic strains were Esch. coli; the others belonged to Klebsiella, Enterobacter, Proteus, Citrobacter, Serratia, and Aeromonas. In 18 patients both isolates were toxinogenic and belonged to different species. The incidence of intestinal parasites was 35% with no apparent correlation to the occurrence of toxinogenic bacteria in the stools.

Biological Assay↗