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Biomedical subjects

J Knobloch

Publications and source records attributed to J Knobloch.

At least 73 records · Page 4Linked to original sources
PubMed1985

Antibodies to Bartonella bacilliformis as determined by fluorescence antibody test, indirect haemagglutination and ELISA.

Two strains of Bartonella bacilliformis were cultured on Columbia agar supplemented with 5% defibrinated human blood. Antigens prepared from these cultures were used for determination of antibodies by fluorescence antibody test (FAT) indirect haemagglutination (IHA) and an enzyme immunoassay (ELISA). One hundred and eighty-seven human sera from B. bacilliformis-endemic areas of Peru were tested of which 63.6% were reactive. ELISA was the most sensitive test, followed by FAT and IHA. IgM antibody was determined by FAT with the IgM fraction of test sera. It was present not only in patients with Oroya fever but also in some healthy individuals as well as in one patient with chronic bartonellosis (verruga peruana). Substantial differences in antigenic activity between the two strains of B. bacilliformis were not observed. Cross reactivity with sera containing antibodies to bacteria other than B. bacilliformis was not noted. For identification of Oroya fever patients in the field, an eosin/thiazine stain of blood smears was found to be appropriate.

Antibodies, Bacterial↗
PubMed1985

Human fascioliasis in Cajamarca/Peru. I. Diagnostic methods and treatment with praziquantel.

In a prospective study 34 Peruvian fascioliasis patients were followed up for three months after treatment with praziquantel. The rapid sedimentation of faeces was demonstrated to be the most appropriate parasitological technique for the diagnosis of Fasciola hepatica infections in man compared to the MIF concentration or the examination of duodenal fluid by Enterotest. After therapy with different doses of praziquantel only 21% of the patients stopped to excrete worm eggs although 17 patients had been treated repeatedly. During the period of observation all patients presented a decreasing number of symptoms. It is concluded that praziquantel is not very active against F. hepatica in man.

Adolescent↗
PubMed1985

Human fascioliasis in Cajamarca/Peru. II. Humoral antibody response and antigenaemia.

Four immunoassays (IgG ELISA, indirect haemagglutination = IHA, IgM ELISA and antigen ELISA) for determination of humoral antibody and of circulating antigen, respectively, were applied to sera of 45 Peruvian fascioliasis patients who were identified by demonstration of Fasciola eggs in faeces. All of the sera were reactive by at least one of the assays. Sensitivity rates were 0.98 for IgG ELISA, 0.56 for IHA, 0.51 for IgM ELISA and 0.20 for antigen ELISA. Among those 34 patients who were followed up after praziquantel therapy there was a different pattern of immunoassay results between patients who stopped excreting eggs after therapy and those who continued to pass eggs. Cure was indicated by disappearance of both IgM antibody and antigen levels during three months after treatment, whereas persistence of infection corresponded to new or re-occurrence of IgM antibody and/or circulating antigen during the period of observation. Since there was no apparent relation of immunoassay results to therapy, it is presumed that the Peruvian patients did not respond to praziquantel at all.

Adolescent↗
PubMed1985

Serum antibodies in patients with alveolar echinococcosis before and after therapy.

Thirty-three patients with alveolar echinococcosis treated by surgery or with mebendazole were observed up to six years. Of three immunoassays (IgG ELISA, complement fixation, indirect haemagglutination) correlation with the clinical course was achieved by IgG ELISA only. Serum antibody levels tended to increase during the first year and decreased during the second year after therapy had been started, Long persisting antibody was most sensitively indicated by indirect haemagglutination.

Antibodies↗
PubMed1985

Immunodiagnosis of cysticercosis: standardization of ELISA and its application to field conditions.

A standardization procedure for the enzyme-linked immunosorbent assay (ELISA) is described. Results were expressed as antibody units (ABU) which represent a multiple of absorbance of the negative control. The method was applied to immunodiagnosis of cysticercosis by IgG antibody determination. Different incubation temperatures had no substantial effect on results. There was a fair correlation between results obtained under field conditions in Cajamarca/Peru and results obtained under optimal laboratory conditions in Hamburg/FRG. Activity of antigen that had been lyophilized and stored under vacuum at ambient temperature was similar to the activity of antigen that had been stored frozen. There was a considerable loss of activity when antigen had been adsorbed to microtitre plates which were then stored in evacuated plastic bags at room temperature. Reproducible results were obtained both under optimal laboratory conditions and in the field.

Adsorption↗
PubMed1984

Protozoal enteric infections in homosexual men.

The prevalence of enteric protozoal infections was examined in a group of 200 homosexual men. Entamoeba histolytica (E. histolyt .) was found in 22.8%, apathogen amoeba in 54.5% and Giardia lamblia (G. lamblia) in 9.1% of the participants. Antibodies against E. histolyt . were significantly higher in subjects carrying E. histolyt . than in the group with apathogen amoeba and in uninfected participants. Clinical symptoms were not associated with protozoal infection. The analysis of a number of variables showed that oral-anal sex and promiscuity were the two most important risk factors for protozoal infection. The clinical significance of protozoal enteric infections and their possible relation to the acquired immune deficiency syndrome (AIDS) is discussed.

Adolescent↗
PubMed1984

Species-specific immunodiagnosis of human echinococcosis with crude antigens.

Crude soluble antigens were evaluated with indirect haemagglutination and ELISA for their specificity in the immunodiagnosis of alveolar and cystic echinococcosis. Using a combination of heterologous crude antigens, the ELISA method made a correct species-specific diagnosis in 96.3% of the patients. These results are similar to those obtained by immunodiagnosis with purified antigens.

Antibodies↗
PubMed1984

Serum antibody levels in human paragonimiasis before and after therapy with praziquantel.

Enzyme immunoassays (ELISA) and indirect haemagglutination (IHA) were used to determine IgG and IgE serum antibody levels in 43 patients from Ecuador before and after therapy with praziquantel. ELISA indicated infection more sensitively than IHA. The tendency of increasing antibody levels between the first and second month after therapy was more distinct when measured by IHA, whereas the decreases of antibody levels between the third and sixth month after treatment was more distinct when measured by ELISA. The IgG ELISA for detecting long persisting antibody was more sensitive than IHA.

Antibodies↗
PubMed1984

Evaluation of immunoassays for diagnosis and management of sleeping sickness in Liberia.

Nineteen parasitologically confirmed Liberian sleeping sickness patients were observed for up to 40 months. Efficacy of suramin therapy was indicated by decrease of serum and CSF immunoglobulins as well as by decreasing IgG and IgM serum antibody levels as determined by ELISA and fluorescence antibody tests. The tendency of serum antibody concentrations to increase again during the second and third years after treatment could be explained in one patient only who experienced relapse or reinfection, confirmed by demonstration of blood trypanosomes. Known endemic and nonendemic areas in Liberia could not be discriminated by the prevalence of Trypanosoma IgG antibodies. Furthermore, IgM antibody was present in 18% of a random sample of sera from non-endemic ares. The possibility of trypanosomes other than T.b. gambiense to stimulate antibody production in man is discussed.

Animals↗
PubMed1984

Application of different Paragonimus antigens to immunodiagnosis of human lung fluke infection.

Utilizing enzyme immunoassay, Paragonimus africanus, P. uterobilateralis, P. ecuadoriensis and P. westermani antigens were tested with regard to their reactivity to sera from patients infected with Paragonimus africanus, P. uterobilateralis, P. ecuadoriensis, Fasciola hepatica, Opisthorchis viverrini, different schistosomes, Cysticercus cellulosae, nematodes and from patients with nonparasitic diseases as well as from healthy blood donors. Simultaneous application of Paragonimus antigens to each serum led to a pattern of reactivity which rendered possible species-specific diagnosis. Most distinct cross reactivity occurred with fascioliasis sera, followed by opisthorchiasis, schistosomiasis and sera from patients with cysticercosis. Cross-reactivity was observed to least extent when P. westermani antigen was applied. A follow-up study of 42 paragonimiasis patients treated with praziquantel (2-cyclohexylcarbonyl-1,2,3,6,7, 11b-hexahydro-4H-pyrazino[2,1-a]isoquinolin-4-one, EMBAY 8440, Biltricide) demonstrated that substantial decrease of IgG antibodies occurred between the first and sixth months after therapy, whereas change of IgE antibody levels was less conclusive.

Antigens, Helminth↗
PubMed1983

[Intestinal protozoal infestation in persons with occupational sewage contact].

Intestinal protozoal infestation and antibodies against Entamoeba histolytica were determined in 614 employees of the Hamburg sewage works and compared with control groups without occupational sewage contact. The protozoal infection rate was significantly higher in sewer-men than in control persons. There was a positive correlation between the duration of exposure to sewage and the frequency of intestinal protozoal infestation. The risk of infection by sewage was higher than by a short journey to tropical or subtropical countries. Immunodiagnostic results showed no significant differences of invasive activity of E. histolytica between both investigated groups. On the basis of parasitological results classification of amoebiasis and giardiasis as occupational diseases in exposed persons is recommended.

Entamoeba histolytica↗
PubMed1983

Development and persistence of antibodies to Entamoeba histolytica in patients with amebic liver abscess. Analysis of 216 cases.

The antibody patterns--obtained by enzyme immunoassay (EIA), complement fixation (CF), indirect hemagglutination (IHA), and latex agglutination (LA)--of 216 patients with amebic liver abscess (ALA) were related to the time of onset of illness and to epidemiological data. The usual period between the stay in an Entamoeba histolytica-endemic area and clinical manifestation of the disease was 8-20 weeks. Increasing antibody concentration affected the sensitivity rates for CF and LA in the first 3 weeks of clinical ALA. In comparison with CF, IHA, and LA, EIA was the most sensitive test, showed the most substantial changes in antibody concentration according to the stage of disease, and measured persisting antibodies for the longest period. Neither the duration of previous stay in tropical countries nor the time when specific chemotherapy was started influenced development or persistence of antibodies in ALA patients. ALA occurred with similar frequency regardless of whether the patient was a long-term resident of the tropics or a short-term visitor to an E. histolytica-endemic area.

Adolescent↗
PubMed1983

Immunodiagnosis of human paragonimiasis by an enzyme immunoassay.

An enzyme immunoassay was applied to stepless antibody determination in sera from patients with paragonimiasis africanus, paragonimiasis uterobilateralis, paragonimiasis ecuadoriensis, other helminthic infestation, non parasitic diseases and healthy individuals. Crude extracts from adult P. africanus, P. uterobilateralis, P. ecuadoriensis and P. westermani worms served as antigen. The most distinct cross reactivity occurred with sera containing F. hepatica antibodies. Cross reaction was observed to least extent when P. westermani antigen was utilized. By comparison of results obtained by homologous and heterologous Paragonimus antigen it was demonstrated that even species-specific diagnosis of paragonimiasis may be possible when using this system.

Diagnosis, Differential↗
PubMed1983

Specific IgE antibodies and IgE containing circulating immune complexes in human schistosomiasis.

IgE antibodies (IgE-AB) have been investigated in patients infected with S. mansoni, S. haematobium, S. mansoni and S. haematobium or S. intercalatum using an enzyme immuno assay based on the RAST principle. Antigens applied were crude extracts from S. mansoni, S. haematobium and S. japonicum adult worms. IgE containing immune complexe (IgE-CIC) were determined by precipitation with PEG and subsequent identification with I125 labelled antihuman IgE. In the patients with schistosomiasis IgE-AB to the homologous antigen were demonstrated in 84% of monoinfected and in 100% of the mixed-infected individuals. Within the mixed-infected patient group IgE-AB to S. mansoni antigen were significantly higher than to S. haematobium. Cross-reactivity of IgE-antibodies was proved by use of S. haematobium and S. japonicum antigen in S. mansoni monoinfection . Specifity of the test was 94%. The amount of IgE-CIC correlated significantly with the concentration of the homologous IgE-AB, indicating that these CIC were composed of specific antibodies linked to parasite antigen.

Antigen-Antibody Complex↗
PubMed1983

Serological and immunological investigations in patients with gross splenomegaly from the Gabon.

Serological investigations (immunoglobulin, haptoglobin, cryoglobulin, and antibody determination against Plasmodium falciparum and P. malariae antigens) were performed in 64 adults of the Albert-Schweitzer-Hospital, Lambarene, Gabon. The patients were referred consecutively for ultrasound examination of the upper abdominal tract. 31 patients had clinically and sonographically an enlarged spleen, whereas 34 had a normal-sized spleen. 18 patients were regarded as having a gross splenomegaly without an obvious underlying cause (tropical splenomegaly (TSS]. No significant differences were seen between the patient groups with regard to immunoglobulin M or antiplasmodial antibody concentration. Thus, a causal association of splenomegaly with chronic malaria infections could not be established. The haptoglobin levels were significantly (P less than 0.01) reduced in patients with splenomegaly. Peripheral T-lymphocyte subsets as defined by monoclonal antibodies showed in all 4 cases with gross splenomegaly examined distinct abnormalities. Tropical splenomegaly is thought to encompass a variety of diseases, most of them presenting an intermediate stage of reactive to autonome disorders of the lymphatic system.

Adolescent↗