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G Huldt

Publications and source records attributed to G Huldt.

At least 19 recordsLinked to original sources
PubMed1996

Visceral leishmaniasis in Somalia. Significance of IgG subclasses and of IgE response.

We have determined the levels of IgG subclasses and IgE as well as specific antibodies of these isotypes in sera from 22 patients with clinical visceral leishmaniasis (VL) from Somalia. The results are compared with those obtained from 30 Somali and 23 Swedish controls. We found markedly increased concentrations of IgG1 in the VL sera, indicating that the pronounced increase in IgG in VL which is generally considered to be due to polyclonal B-cell activation is mainly restricted to this subclass. The IgG2 concentrations were significantly decreased. The IgG3 and IgG4 concentrations, on the other hand, did not differ between the two groups of Somali sera. The Somali control sera contained higher concentrations of IgG1 and IgG3, but significantly lower concentrations of IgG2 as compared to Swedish controls. The IgG4 values, on the other hand, were not different between the two groups of control sera. Anti-leishmania antibodies belonging to all IgG subclasses, were found in the patients' sera. There was no significant difference in total IgE between sera from VL patients and controls and specific IgE antibodies were only detected in a few patients. The Western blot assay (WB), revealed the presence of two bands corresponding to 74 kDa and 88 kDa in all patients' sera, indicating a possible diagnostic role for WB in this particular population.

Animals↗
PubMed1995

Visceral leishmaniasis in Somalia. Circulating antibodies as measured by DAT, immunofluorescence and ELISA.

Sera from patients with visceral leishmaniasis (VL) (n = 26), healthy residents of Mogadishu (n = 157), inhabitants of a village in an endemic area (n = 276) and healthy Swedes (n = 60) were examined using the direct agglutination test (DAT), immunofluorescence (IF) and ELISA for antibodies against Leishmania donovani. The study was carried out in order to provide baseline data for antibody responses in visceral leishmaniasis as existing in Somalia and to explore which one of these methods would be most suitable for diagnosis of clinical cases as well as for epidemiological population studies in Somalia. All patients had high levels of circulating antibodies, however, lower values were recorded in the early stages of the disease. High reactivity in ELISA was seen first after one year. All three tests distinguished well between sera from VL patients and healthy controls. Approximately 10% of the sera from villagers were reactive above the cut-off levels in the three tests. DAT is the simplest to perform and does not require much equipment. ELISA can be made simple and economic if performed in one serum dilution and read visually. IF requires more expensive and specialized equipment and is not suitable for large scale examination of sera. A complete evaluation of the three tests should also include the analysis of sera from various stages and manifestations of the disease.

Adolescent↗
PubMed1994

Reference ranges for IgG, IgM and IgA in the serum of urban and rural Somalis.

In order to provide baseline data for an immuno-parasitological laboratory in Somalia, serum concentrations of IgG, IgM and IgA were determined in some key populations: healthy residents of Mogadishu (n = 157), inhabitants of the village of Daimo Samo (n = 276) and patients with malaria (n = 39) and visceral leishmaniasis (n = 26), both protozoan infections accompanied by hypergammaglobulinaemia and causing severe health problems in Somalia. Since the serum immunoglobulin concentrations in the Somali populations studied were not normally distributed, they were evaluated using medians and percentiles. Significantly higher values of IgG, IgM and IgA were demonstrated in healthy Mogadishu residents as compared to healthy Swedes. Daimo Samo villagers had significantly higher IgG and IgM values than healthy Mogadishu residents. Very high concentrations of IgG and IgM were demonstrated in sera from patients with visceral leishmaniasis. Somali patients with malaria also had marked hypergammaglobulinaemia, however, only in the IgG class. The high levels of IgG, IgM and IgA demonstrated in sera from Somalis, indicate the need for establishing local reference values and should be considered when introducing serological tests in tropical countries. Such methods are usually adopted to conditions in industrialized countries, where immunoglobulin contents of sera are lower.

Adolescent↗
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↗
PubMed1988

Human toxoplasmosis in Somalia. Prevalence of Toxoplasma antibodies in a village in the lower Scebelli region and in Mogadishu.

The acquisition of Toxoplasma antibodies in various age groups was studied in 2 populations in Somalia, inhabitants of a village in the southern part of the country and residents in Mogadishu. The overall prevalence of antibodies was 56% in the village and 40% in Mogadishu. In both populations, antibodies were acquired early in life. At the age of 10 years, 44% of the villagers and 31% of the Mogadishu children were seropositive. In Europe and the USA the highest rate of antibody acquisition has been recorded in young adults. This difference may indicate different routes of transmission. In Europe and the USA Toxoplasma is transmitted mainly by the ingestion of undercooked pork or lamb. Undercooked meat is seldom consumed in Somalia, and pork not at all. However, the soil in Somalia is heavily contaminated with cat faeces and the humid climate in the southern part of the country may contribute to long survival of oocysts. In the villages all household activities are performed on the ground and in Mogadishu children play mainly outdoors on the ground. It therefore seems that conditions in Somalia favour transmission by oocysts rather than by infected meat. The early acquisition of antibodies in Somalia suggests that infection during pregnancy and, therefore, congenital toxoplasmosis are rare.

Adolescent↗
PubMed1984

Amoebicidal activity of the antifungal antibiotic sinefungin against Entamoeba histolytica.

The antifungal antibiotic sinefungin, a potent inhibitor of methyl transferases and a potential inhibitor of polyamine biosynthesis, exhibited marked cytolytic activity against Entamoeba histolytica in vitro with respect to all the amoeba strains tested. Strains of high and low virulence displayed equal sensitivity to the antibiotic. Minimal Amoebicidal Concentration was 5 to 10 micrograms/ml.

Adenosine↗
PubMed1984

Cerebral schistosomiasis presenting as a brain tumor.

A patient with cerebral Schistosoma mansoni schistosomiasis is described. The infection presented as a cerebral tumor, and the patient did not have the usual hepatic or intestinal symptoms of this disease. The computed tomography (CT) findings in histologically proven cerebral schistosomiasis are reported. The pathological CT findings developed at a late stage of the disease, and the CT scans were normal at a time when the EEG recordings were pathological.

Adult↗
PubMed1983

Amoebiasis and giardiasis in Bangladesh: parasitological and serological studies.

To determine the prevalence of infections with Entamoeba histolytica and Giardia lamblia in Bangladesh, we screened stool specimens from patients with diarrhoea attending urban (N = 2,246) and a rural (N = 2,791) hospital and a group of healthy urban residents (N = 440). Sera from 200 healthy villagers were also examined for antibody to E. histolytica using the immunofluorescent antibody test. The prevalence of E. histolytica cysts or trophozoites in all groups assessed by examination of a single stool specimen ranged from 0% among infants (less than 1 year) to 34% among healthy adults 30 to 44 years old. G. lamblia was uncommon in infants and found most frequently in urban hospital patients aged five to nine (21%). 12% of one- to two-year-old children had serum antibody to E. histolytica at a titre of 1:40. By age 14 years, 80% of those tested were seropositive, and this prevalence declined thereafter with increasing age. Amoebiasis and giardiasis occur frequently in Bangladeshi populations and the morbidity and mortality associated with these infections need to be assessed.

Adolescent↗
PubMed1983

Giardia lamblia infections in a cohort of Bangladeshi mothers and infants followed for one year.

Giardia lamblia infection in an endemic area was investigated by following a cohort of 33 lactating mothers and their infants in a semiurban community of Bangladesh for one year. Eighty-two percent of mothers and 42% of infants excreted Giardia at least once during the study period. Infants became infected as early as 3 months of age, and 86% of the infected infants had diarrhea, suggesting that the first exposure to the parasite results in disease. Only one of the infected mothers had diarrhea, indicating that with repeated exposure to Giardia, mothers in an endemic area may develop partial immunity that protects against disease but not infection. An interrelationship between maternal and infant colonization was not found. Local and systemic immune responses to Giardia correlated poorly with infection, but milk antibodies were a better reflection of infection than serum antibodies were. Infection with G. lamblia was significantly lower in infants younger than 6 months (9%), an age when many are totally breast-fed. However, we were unable to establish clear-cut protection related to human milk antibodies, and suggest that the lower infection rate in younger infants results mainly from decreased exposure to Giardia cysts.

Adolescent↗
PubMed1983

Antibody-independent binding and activation of complement by Schistosoma mansoni adult worms.

The in vitro binding serum complement (C) components to Schistosoma mansoni worms was studied. By exposing frozen sections of adult male and female parasites to normal human serum, binding of both classical and alternative pathway C components was observed. By immunofluorescence (IFL) microscopy selective binding of Clq, C4 and C3 to the schistosomal tegument, internal structures, the intestinal tract and eggs was seen. The C4 and C3 binding was completely abolished in the presence of 10 mM EDTA. EGTA also completely inhibited binding of C4 and most of the C3 binding. These results suggest that C binding to S. mansoni adult worms occurs mostly by the classical activation pathway. However, the partial Ca2+ independence of C3 binding and the demonstrated binding of the regulatory protein beta 1H suggests that worms are capable also of C3 binding by the alternative pathway. No C binding occurred to intact worms. Although some in vivo bound immunoglobulin appeared to be present occasionally at the parasite surface and in the gut, this material did not account for the demonstrated extensive C deposition upon incubation of frozen sections with normal human serum in vitro. Antibody independence of the observed classical pathway C binding was further indicated by binding of isolated Clq to the same structures capable of binding C components from serum.

Animals↗
PubMed1983

Antibodies against Entamoeba histolytica in human milk and serum in Kenya.

A modified enzyme-linked immunosorbent assay (ELISA) technique has been developed for the detection of secretory immunoglobulin A (SIgA) antibodies against Entamoeba histolytica. By substituting phosphate-buffered saline-Triton for phosphate-buffered saline-Tween as the antibody incubating buffer, unspecific absorption of SIgA was avoided. As revealed by chessboard titrations, the optimal amount of antigen for coating was higher in SIgA than in IgG ELISA. A purified antigen from the membrane pellet fraction of E. histolytica gave equally good reactivity with SIgA and IgG antibodies and was used throughout. A total of 283 milk and 232 serum samples from three areas in Kenya were tested. The samples were collected in maternity hospitals on one of days 1 to 3 after parturition. All milk samples were tested for total SIgA. In one of the study areas (Machakos), the mean level of SIgA was significantly lower than in the other two areas (Mombasa and Nairobi). Eighty-seven of the milk samples (31%) were reactive in the test. The rate of positives was higher in Mombasa, where the SIgA levels were highest. Since both the frequency and the level of serum antibodies were similar in the three study areas, it is likely that the higher milk reactivity in Mombasa was mainly due to the higher SIgA concentrations observed. Antibodies were detected in 32 (14%) of the sera, mostly in low or moderate titers. Surprisingly few mothers had detectable antibodies in both milk and serum. In fact, the majority of positives were reactive in either milk or serum, with a predominance of milk positives. The background for this is probably complex, containing components such as differences in immunoglobulin concentrations in the samples, diversities in local and systemic antigenic stimulation responses, and level of immunological memory.

Amebiasis↗