PubMed Health⌕ Search

Biomedical subjects

G Huldt

Publications and source records attributed to G Huldt.

17 recordsLinked to original sources
PubMed1992

Amebiasis in Nicaragua: class specific serum antibody responses.

With the aid of the indirect hemagglutination (IHA) test and IgG ELISA the antibody profile against E. histolytica in León, Nicaragua was investigated in 562 sera from individuals belonging to various age groups. The highest reactivity was invariably recorded in the age group 6-15 years where 48% were seropositive. Several sera reactive by either one of IHA and IgG ELISA were negative by the other test. The main reason for this seems to be reactivity in different Ig classes. Treatment with 2-mercaptoethanol reduced the titre level in 63 of the 66 sera tested. Immunofluorescence using an anti-IgM conjugate showed that 26 of 43 sera contained specific IgM-antibodies, indicating that also unspecific reactions are involved in the IHA test. A comparison was made between class-specific reactivity in three population groups: healthy residents, healthy cyst carriers and patients with recent or acute liver abscess. No significant difference in the prevalence of reactions above the diagnostic significance level was recorded between cyst carriers and healthy residents. However, among the cyst carriers 33% had IgA and/or IgM antibodies but no demonstrable specific IgG. Most patients with recent and all with acute liver abscess reacted significantly above the diagnostic limit in all three tests.

Adolescent↗
PubMed1990

Antibody responses in schistosomiasis haematobium in Somalia. Relation to age and infection intensity.

Antibody responses in schistosomiasis haematobium were studied in relation to age and infection intensity in Somalia. The area is highly endemic for Schistosoma haematobium but free of S. mansoni. Antibodies of the IgG class against particulate antigens of S. mansoni adult worms were investigated by immunofluorescence (gut and somatic associated antigens) and against soluble egg and adult worm antigens by ELISA. Total IgE levels were examined by Pharmacia IgE RIA, and specific IgE against soluble adult worm antigen by enzyme immunoassay. The IgG antibody response showed a characteristic pattern with highest reactivity against both gut associated and soluble egg antigens in the age group 10-14 years, when both prevalence and intensity of the infection were highest. Reactivity against somatic associated antigen was also high in this age group, but it increased slightly and remained at high level in the older ages. It is thought that such antigen is exposed mainly after the death of the parasite and that the antigenic stimulation may remain throughout most of the life of infected individuals. On the other hand, the IgG antibody reactivity against soluble adult worm antigen was low during childhood, but it increased significantly with age. It is suggested that repeated booster effects are needed for more potent response against these antigenic components. The finding of high levels of total IgE already in the youngest age groups, together with low specific IgE response, indicates that mainly other antigens are involved in the IgE production. The specific IgE response against soluble adult worm antigen was low but increased significantly with age.

Adolescent↗
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

Incidence of toxoplasmosis in pregnant women in the city of Malmö, Sweden.

The incidences of latent and primary Toxoplasma gondii infections in pregnant women were studied using stored sera from 4,351 women delivered in the city of Malmö, Sweden in 1982 and 1983. Infants born to mothers with signs of primary infection (seroconversion or specific IgM in sera collected during pregnancy) were studied with regard to serological evidence of congenital infection (specific IgM in cord serum). Sera were tested for specific IgG antibodies by direct agglutination test and enzyme-linked immunosorbent assay, and for specific IgM by immunosorbent assay. 40% of the women were seropositive at delivery. Seroconversion (change from negative to positive serological status) was demonstrated in 12 pregnant women and specific IgM in the first postconceptional serum sample (indicating infection in the first trimester or in the last year(s) before conception) in another 17. The incidence of primary maternal infection was calculated to 4-6:1,000 deliveries. Among the 29 infants born to mothers with seroconversion or, alternatively, IgM in the first postconceptional sample, 6 had laboratory signs of congenital infection. One of the 6 had a positive toxoplasma isolation test in autopsy material and 5 had a clearly positive IgM value in cord serum. The real incidence of congenital infection in this material is unknown since IgM might be absent or sparse in cord serum in spite of congenital infection. The noticeable prevalence of maternal toxoplasmosis in Malmö calls for further incidence studies in Sweden.

Adult↗
PubMed1989

Detection of giardia antigen in stool samples by a semi-quantitative enzyme immunoassay (EIA) test.

A semi-quantitative enzyme immunoassay (EIA) test for the detection of Giardia intestinalis antigen in faeces was developed. In order to avoid unspecific reactions due to anticalf serum activity, IgG fractions of anti-giardia rabbit and sheep sera were purified from antibovine antibodies by immunoadsorption. Faecal specimens tested in the assay were mixed with normal horse serum to avoid unspecific and proteolytic effects of stool components. Out of a range of bacterial and parasitic antigens tested, only high concentrations of Ascaris suum egg antigen and Shigella sonnei gave slight unspecific reactions. During an outbreak of waterborne giardia infection faecal samples from 49 individuals were tested. Giardia cysts were found by microscopy in 22 individuals and specimens from 24 persons were positive by EIA. The estimated amount of antigen found in the positive samples ranged from 50 to 5,000 ng giardia protein/ml. After filtration through a 0.45 microns filter antigenic activity was found in the filtrate of 10 samples. In 3/6 samples with no cysts detected by microscopy, mainly soluble giardia antigen was found.

Adolescent↗
PubMed1988

The prevalence of Entamoeba histolytica in lactating women and in their infants in Bangladesh.

Entamoeba histolytica was studied in 33 lactating women and their infants in a periurban village in Bangladesh. Infant-mother pairs were followed for a period of 10-15 months: 67% of mothers excreted E. histolytica during the observation period, the majority for 3 months or more. Only one mother was symptomatic, with a mild, non-dysenteric diarrhoea. 58% of mothers were seropositive, several of them continuously and with a high titre, indicating past invasive infection. 67% had detectable antibodies in breast milk and 36% in saliva. Despite the high prevalence of E. histolytica in these mothers, infants were mostly uninfected: E. histolytica cysts in small numbers were found in only 2 of 1200 samples from infants aged 6 and 10 months. Several of the children were infected with Giardia lamblia. Although lower exposure to E. histolytica than to Giardia may account for the difference in infant infection rates with these parasites, defence mechanisms possibly exist which protect against E. histolytica but are ineffective against Giardia.

Adolescent↗
PubMed1979

On the epidemiology of human toxoplasmosis in Scandinavia especially in children.

A random sample representing approx. one-third of pre-school children and approx. 95% of school children in age groups 8, 11, 13, and 15 years in a suburb of Stockholm were examined for antibodies to Toxoplasma. Antibodies were uncommon in small children. They gradually appeared throughout childhood but especially in adolescence and adult life. Antibodies were more common in females than in males. Even small girls were more often infected than boys of corresponding age. The difference becomes marked in puberty and is significant in adults. A family study revealed evidence of familial aggregation of the infection albeit with borderline significance. No correlation was found between occurrence of antibodies and the presence of cats in the families or reported consumption of raw meat. The majority of representative samples of Lapps and Skolt Lapps in northern Scandinavia lacked antibodies to Toxoplasma.

Adolescent↗
PubMed1977

Effect of experimental trichinosis on unrelated humoral and cell mediated immunity.

Immune responses to unrelated antigens were studied during the course of Trichinella spiralis infection in mice. A transitory depression of the IgM response to the thymus dependent antigen, sheep erythrocytes, was seen three weeks after infection and this effect was more pronounced after challenge. A depression of the IgG response also was observed, however, not until 6 weeks after infection. The humoral response to the thymus independent antigen, polyvinyl pyrrolidone showed a slight increase which was most evident in challenged mice. The nonspecific cellular immune response, as measured by the split heart allograft technique, showed a profound and longlasting depression. This effect was mot pronounced one week after inoculation, when the parasite resides mainly in the intestine. The time at which the nonspecific cellular immunity was most depressed coincides with the period of strong specific cell mediated immunity. It is also shown that experimental trichinosis in CBA mice is accompanied by profound but transient changes in the thymus reflected mainly as a depletion of cortical thymocytes. These changes were not due to corticosteroids or malnutrition. There is reason to believe that thymic depletion is of significance for the depressed antibody response, but not for the prolonged survival of allografts. These findings indicate that T. spiralis affects the nonspecific immunity at different levels.

Adrenalectomy↗
PubMed1977

On porcine toxoplasmosis in Sweden.

An outbreak of fatal toxoplasmosis in piglets, probably of congenital origin is described. Although this is the first known manifest case of porcine toxoplasmosis in Sweden it is concluded that it is based on a well established latent infection of the pig population in the area concerned. Of a random sample of clinically healthy slaughtered pigs from the area 40.3 per cent were positive in Sabin-Feldman dye-test.

Acute Disease↗
PubMed1976

Tumorigenicity of Epstein-Barr virus (EBV)-transformed lymphoid line cells in autologous squirrel monkeys.

Eight squirrel monkeys (Saimiri sciureus) challenged with EBV or EBV-transformed SLCL were naturally or experimentally infected with Plasmodium knowlesi or Pl. brasilianum. Most of the animals had been splenectomized and unilaterally nephrectomized. Three of these monkeys received one dose of 6 to 12 X 10(8) autologous SLCL. These lines were derived from saimiri lymphoid cells permanently transformed by B-EBV in vitro. All three animals developed multiple undifferentiated malignant lymphomas and died 8 to 10 days post inoculation. Necropsy tumor specimens were EBNA-positive and contained 7 to 21 EBV genome equivalents per cell. EBNA- and EA-positive SLCL were established in vitro from four tumor explants of two monkeys. These results demonstrate that in vitro EBV-transformed SLCL are able to cause tumor formation in autologous squirrel monkeys. Five monkeys received high transforming doses of B-EBV or S-EBV, derived from one of the tumorigenic SLCL. None of the animals developed any sign of tumor formation during an observation period of up to 130 days. Three of these monkeys showed no detectable EBV-related seroconversion while the sera of two monkeys had become anti-EBNA-positive when tested at days 28 and 130 respectively post inoculation. Two additional monkeys received neither EBV nor SLCL. They showed no clinical evidence of tumor development or spontaneous seroconversion over a period of more than 1 year.

Animals↗
PubMed1975

New serological test for malaria antibodies.

In an enzyme-linked immunosorbent assay test for malaria antibodies, antibodies to Plasmodium vivax and P. falciparum in man are detected using a crude antigen prepared from the simian malaria parasite P. knowlesi. The test may be suitable for epidemiological studies.

Adsorption↗