Search PubMed⌕ Search

Biomedical subjects

B Gottstein

Publications and source records attributed to B Gottstein.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Parasitologic, clinical, hematologic and serologic findings in puppies after lactogenic infection with Ancylostoma caninum ERCOLANI 1859 (Ancylostomidae)].

The correlation between intensity of Ancylostoma caninum infections in bitches and the intensity of lactogenic infections and clinical signs of their puppies was investigated. On average, 825, 1,867 or 2,125 specimens were observed in litters of two bitches inoculated with 5,000, 10,000 or 20,000 third stage larvae (LIII) respectively, at the day of conception. Adverse effects of the infection on the growth and behaviour of the puppies were observed after onset of their second week of life: 11/27 puppies died during the fourth week. The body weight of puppies surviving 28 days was up to 750 g less than that of uninfected controls. Eosinophilia, erythroblastosis and microcytic, hypochromic anemia developed in all puppies during their first four weeks. The IFA test (LIII antigen) was positive for only 5/18 heavily infected puppies after uptake of colostrum.

Ancylostoma↗
PubMed1990

Echinococcus multilocularis: characterization of a DNA probe.

A 0.6 kb DNA fragment has been isolated from a genomic sublibrary of the cestode Echinococcus multilocularis. This DNA-fragment showed a strong hybridization signal to 32PdCTP labeled total DNA prepared from E. multilocularis metacestode material. The fragment was subcloned into the Escherichia coli vector Bluescript BS+ resulting in the recombinant plasmid pAL1. The recombinant parasite DNA probe was labeled by biotinylation and hybridized to Southern blots of resolved EcoRI/PstI digested genomic DNA originating from E. multilocularis, E. granulosus and other helminth species (Taenia hydatigena, T. crassiceps, T. saginata, Mesocestoides corti, Hymenolepis diminuta, Moniezia expansa). The Southern blot hybridization experiments revealed that the DNA probe pAL1 was specific for E. multilocularis and E. granulosus. By comparison of the hybridization banding patterns a clear discrimination between E. multilocularis and E. granulosus was possible at the genome level. Furthermore, pAL1 was used to detect genetic variation within a set of different E. multilocularis isolates which had been experimentally maintained in mice by parasite tissue transplantation.

Animals↗
PubMed1990

Serological survey of human cysticercosis in Irianese refugee camps in Papua New Guinea.

In 1984, over 10,000 refugees left the Indonesian province of Irian Jaya, and thus possibly imported Taenia solium taeniasis/cysticercosis into Papua New Guinea, which was believed to be free of T. solium until 1966. In a serological survey carried out in 1986, 50 refugees originating from areas endemic for T. solium and 171 patients from other areas with symptoms suggesting the possibility of cysticercosis were examined. As a sensitive prescreening technique an ELISA was used with a crude antigen extract obtained from T. solium metacestodes of pig origin. Of 221 persons investigated, 79 (36%) were positive in ELISA. For excluding frequently occurring cross-reactions in ELISA, Western-blotting (or EITB, enzyme-linked immunoelectrotransfer blot) was employed. In this test the demonstration of antibody activity to the 26 or the 8 kilodalton band has been proved to be species-specific for T. solium cysticercosis. One from 79 patients positive in ELISA was simultaneously positive (26 and 8 kDa) in Western blot, corresponding to the first case found in Papua New Guinea with a highly probable T. solium cysticercosis. This patient, originating from an endemic area in Irian Jaya, had immigrated into Papua New Guinea in 1980. The present work emphasizes the need for using highly specific immunodiagnostic techniques in seroepidemiology of larval cestode infections. T. solium taeniasis/cysticercosis remains a risk for Papua New Guinea, and refugees originating from endemic areas should be regarded as potential carriers of T. solium.

Animals↗
PubMed1990

Detection of Taenia hydatigena copro-antigens by ELISA in dogs.

A sandwich-ELISA was developed for the detection of soluble Taenia hydatigena antigens in fecal samples of dogs. Affinity-purified polyclonal catching antibodies and alkaline phosphatase-conjugated detecting antibodies were employed, which had been obtained from rabbits hyperimmunized with excretory/secretory antigens derived from in vitro maintained adult Taenia hydatigena. The assay allowed the detection of 800 ng T. hydatigena antigen g-1 of feces as a lower limit. Six helminth-free dogs were each infected with 10 T. hydatigena cysticerci isolated from Swiss sheep. After prepatent periods ranging from 57 to 71 days, the dogs started to excrete Taenia eggs and/or proglottids. The ELISA detected Taenia antigens in all six dogs during the prepatent period starting individually between Day 18 and 45 post-infection (p.i.). Anthelmintic treatment of three dogs at Day 95 p.i. resulted in elimination of the cestodes and within the 5 following days in the disappearance of Taenia antigens from feces. The specificity of the assay was evaluated by testing crude antigens derived from helminths or bacteria. Four Taenia species showed cross-reactivity at concentrations of 5 micrograms protein ml-1. Conversely, no cross-reactions occurred with various antigen batches derived from Echinococcus granulosus, E. multilocularis, Dipylidium caninum, Mesocestoides corti, Diphyllobothrium sp., Toxocara canis and bacterial antigens (Salmonella and Escherichia). Moreover, fecal samples from dogs naturally infected with T. canis (n: 13), hookworms (n: 2), Trichuris vulpis (n: 13) and of 10 dogs with mixed infections with these three nematode groups were tested, and results confirmed the high degree of specificity. The Taenia antigens detectable by this ELISA remained immunologically stable in native feces stored at +25 degrees, +4 degrees or at -20 degrees C for at least 5 days.

Animals↗
PubMed1990

Humoral and cellular immune response in mice and dogs induced by a recombinant Echinococcus multilocularis antigen produced by a Salmonella typhimurium vaccine strain.

A gene fragment (II/3-10) from the cestode Echinococcus multilocularis coding for a species-specific antigen was expressed in the live attenuated Salmonella typhimurium vaccine strain LT2 M1C. The recombinant vaccine (S. typhimurium + pVM II/3-10) was assessed for its potential to induce both a humoral and cell-mediated immune response in mice and dogs. Both subcutaneous and peroral administration of the vaccine resulted in antibody synthesis and lymphocyte priming of C57BL/6J mice against S. typhimurium antigens as well as against the recombinant E. multilocularis antigen. Two vaccinated (subcutaneous and peroral) dogs showed a strong humoral immune response to S. typhimurium antigens and to the recombinant E. multilocularis antigen, but proliferation of peripheral blood lymphocytes was not detectable against the bacterial S. typhimurium antigens. Regarding the recombinant E. multilocularis antigen, borderline lymphocyte proliferation was demonstrated following subcutaneous and none following peroral administration of the recombinant vaccine to dogs.

Animals↗
PubMed1990

Antigenic variation in Giardia lamblia: cellular and humoral immune response in a mouse model.

Neonatal mice (CR:NIH:S) were infected with a cloned human isolate of Giardia lamblia (GS/M-83-H7) and the surface antigens of the intestinal trophozoites, as well as the cellular and humoral immune responses, were analysed during the course of infection. Infections in mice peaked 2-3 weeks after inoculation and were self-cured by day 42 post-infection (p.i.). The proportion of trophozoites expressing the Mr 72,000 surface antigen of the initial inoculum had decreased by day 12 and approached zero by day 22 p.i., similar to infections in humans. The predominant parasite-specific humoral response was an IgM- and IgG-isotype directed to the original Mr 72,000 surface antigen as well as other antigens. T-lymphocytes (predominantly LY4(CD4)+) isolated from Peyer's patches 12 days p.i. and later showed a significant proliferative response to Giardia lamblia antigens. Spleen and lymph node cells showed no lymphoproliferative response. T-cell blot analysis revealed the presence of dominant T-cell epitopes in the areas of Mr 200,000-75,000 and less than 50,000 polypeptides. No response was demonstrated in the Mr 72,000 region (migration site of the major surface antigen), suggesting T-cell dependent mechanisms are most likely not responsible for the surface antigen switch which occurred during the course of infection. This model infection can be used to study the role of immunological mechanisms in Giardia lamblia variant antigen switching and in the control of infections.

Animals↗
PubMed1989

Plasmid vector for overproduction and export of recombinant protein in Escherichia coli: efficient one-step purification of a recombinant antigen from Echinococcus multilocularis (Cestoda).

We describe the use of the Escherichia coli plasmid vector, pVB2, for high-level expression and export of recombinant protein. The pBR322 derivative pVB2 harbors the mglB gene, which codes for the galactose-binding protein (GBP) of E. coli. GBP is exported into the periplasmic space of the bacterial cell. Gene mglB contains an EcoRI restriction site close to its 3' end which allows simple in-frame insertion of EcoRI fragments obtained from recombinant lambda gt11 phages. The pVB2 vector was used to express an antigen from Echinococcus multilocularis. The recombinant protein amounted to over 50% of total cellular protein and could be efficiently isolated from the periplasm by osmotic shock. The application of the purified antigen in an ELISA enabled a clear and specific detection of anti-Ec. multilocularis antibodies in human patients' sera, which had been immunosorbed with a periplasmic extract (containing wt GBP) before investigation. These data show the general usefulness of pVB2 as an expression vector for producing in E. coli diagnostically relevant antigens from any infective organism.

Animals↗
PubMed1989

Application of a recombinant Echinococcus multilocularis antigen in an enzyme-linked immunosorbent assay for immunodiagnosis of human alveolar echinococcosis.

A highly antigenic polypeptide fragment of the recombinant Echinococcus multilocularis antigen II/3 was produced in Escherichia coli and purified for application in enzyme-linked immunosorbent assay (ELISA). The antigen II/3-encoding 1.0 kb DNA sequence was reduced by sonication into smaller DNA fragments which were subsequently cloned into lambda gt11. Three clones could be isolated from the sublibrary, all synthesizing a recombinant antigen as a stable beta-galactosidase fusion protein. In a further step, the 0.6-kb insert from one positive clone was subcloned into the plasmid pAR 3038, which directed efficient synthesis of the antigen fused to only 11 amino acids from the N-terminus of the phage T7 major capsid protein. The plasmid-encoded antigen (antigen II/3-10) was purified from a bacterial cell extract and then tested in an ELISA. Using sera from 88 patients with an E. multilocularis-infection, a high diagnostic sensitivity of 90% was demonstrated. Investigation of sera from 220 patients with various helminthic infections showed a specificity of 99%, suggesting the suitability of the antigen II/3-10 as an immunodiagnostic tool.

Animals↗
PubMed1989

Thiabendazole vs. albendazole in treatment of toxocariasis: a clinical trial.

Between 1986 and 1988, 34 patients (age range six to 83 years) with visceral or ocular larva migrans were randomly assigned to a five-day treatment with thiabendazole 2 x 25 mg kg-1 day-1 (15 patients) or albendazole 2 x 5 mg kg-1 day-1 (19 patients). On the fifth treatment day, six patients (40%) in the thiabendazole group and 11 patients (58%) in the albendazole group showed excellent or good drug tolerability. Efficacy of treatment was assessed after 30 weeks (range six to 56 weeks). In the thiabendazole group, median eosinophilia remained at 14% and four patients (27%) were clinically cured. In the albendazole group, the median eosinophilia decreased from 10 to 3.5% and six patients (32%) were clinically cured. We recommend albendazole for treatment of visceral and ocular larva migrans with a minimum dose of 10 mg kg-1 daily for five days.

Adolescent↗
PubMed1989

[Experimental infection of calves and sheep with bovine Giardia isolates].

9 Giardia-free calves were artificially infected with 1.5-5.1 x 10(6) Giardia cysts originating from Swiss cattle ("bovine isolates"). In 4 of these animals the course of infection was examined. After prepatent periods of 7-8 days all calves excreted high numbers of Giardia cysts for 60-112 days. During patency on 44% of the examination days Giardia cysts and antigen could be detected simultaneously in faecal samples using the flotation method and a sandwich-ELISA, respectively. With the exception of light diarrhoea lasting only for some days at the beginning of patency no other symptoms occurred. Further 5 artificially infected calves were submitted to autopsy. Giardia trophozoites were detected in 4 calves in the jejunum and in 1 animal in the ileum (peroxidase-antiperoxidase method). All animals were simultaneously infected with Campylobacter spp. and/or Rota- and Corona-virus. Electronmicroscopically mucosal attachment sites of Giardia trophozoites had intact microvilli and enterocytes. In various parts of the intestine blunting and flattening of the villi and cellular infiltrations of the mucosa were present. These alterations in calves are generally associated with bacterial and/or viral infections of calves. A Swiss bovine Giardia cyst-isolate was transmitted to 4 Giardia-free conventionally maintained lambs which excreted Giardia cysts after prepatent periods of 10-21 days for 31-61 days.

Animals↗
PubMed1989

[Indirect detection of the infectious agents of selected parasitic diseases in animals by immunologic and molecular biological methods].

In this review the following possibilities of indirect detection of causal agents in selected animal parasitoses are discussed: Detection of serum antibodies by ELISA, IFAT and other test systems in leishmaniasis of dogs, babesiosis of horse, cattle and dog, and in toxoplasmosis of cat and various intermediate host species. In leishmaniasis of dogs the specificity of serodiagnosis can be improved by additional Western-Blot analysis. New approaches are provided by the detection of antigens circulating in serum (i.e. in dirofilariasis of dogs) or excreted in faeces (copro-antigens) (i.e. in intestinal parasitoses). Some of the last mentioned techniques are still under evaluation. A new trend in the diagnosis of parasitoses is the application of DNA technologies for the specific identification of causal agents. Some examples are discussed.

Animals↗
PubMed1988

Production of a recombinant antigen of Echinococcus multilocularis with high immunodiagnostic sensitivity and specificity.

A cDNA library derived from mRNA of metacestodes from Echinococcus multilocularis was constructed in the Escherichia coli expression vector lambda gt11 and screened with human patients' sera. The recombinant proteins of 11 positive phages were further evaluated for their potential as immunodiagnostic reagent. One isolated clone (from lysogen II/3) synthesized a fusion protein which was rapidly degraded. This intracellular degradation process provided two distinct polypeptides with Mr of about 31,000 and 33,000, both showing strong binding activity with specific patients' antibodies. The diagnostic value of the II/3-antigen was evaluated by mini-Western-blot with sera from 41 patients infected with E. multilocularis and sera from 77 patients with other helminthic infections, resulting in a diagnostic sensitivity of 98% and an over-all specificity of 96%. These results suggest the usefulness of the recombinant II/3-antigen for immunodiagnosis of human alveolar echinococcosis.

Animals↗
PubMed1987

Cryopreservation of Dictyocaulus viviparus third-stage larvae and Trichinella spiralis muscle larvae.

In cryopreservation studies with third-stage larvae of Dictyocaulus viviparus, best results were achieved by incubating larvae in 0.05% NaOCl at 37 degrees C to remove the sheath, followed by cooling at a rate of 1 degree C min per min down to about 0 degree C. After an equilibration time of 10 min at +4 degrees C with or without 4% polyethylene glycol-400 as cryoprotectant, samples were frozen at the same cooling rate to an intermediate temperature of -20 degrees C, maintained at this temperature for 10 min and finally plunged into liquid nitrogen for storage. Three groups of 3 calves were infected with the following batches of third-stage larvae: (a) fresh, sheated; (b) fresh, exsheathed; (c) exsheathed, cryopreserved for 13 weeks in liquid nitrogen and subsequently thawed. Although 62% of group (c) were regarded as viable in vitro, their infectivity to calves was low and only an average of 0.08% of the inoculated larvae (3000 per animal) developed into adult lungworms (= infectivity rate). Average infectivity rates of fresh, sheathed (a) and fresh, exsheathed (b) larvae were much higher (38.3% and 29.7%) and not significantly different from each other. Two of the calves inoculated with previously frozen larvae and all of the calves infected with fresh larvae excreted first-stage larvae in their faeces, but the latter groups in higher quantities. The results show that cryopreservation of exsheathed third-stage larvae of D. viviparus is possible, but for strain maintenance infection doses greater than 3000 larvae should be used for inoculation of calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Cryopreservation and long-term in vitro maintenance of second-stage larvae of Toxocara canis.

Second stage larvae of Toxocara canis were isolated from developed eggs, frozen in Eagle's Minimal Essential Medium with 5% dimethyl sulfoxide or 10% glycerol as cryoprotectants according to two cooling schedules and maintained in liquid nitrogen for 1 week. After thawing, the previously frozen larvae (FL) and unfrozen controls (CL) were maintained in a chemically defined medium in vitro for 35 weeks. While CL had motility rates around 95% to 97% throughout the experiment, previously frozen larvae (FL) exhibited rates of 48%-58% at the beginning and of 19%-39% at the end of the 35 week in vitro maintenance period. The surviving FL and CL larvae proved to be infective for mice. Excretory/secretory (ES) antigens isolated from several batches of culture medium in which FL and CL had been maintained reacted in the ELISA with human sera containing antibodies against Toxocara. Antigens from FL and CL separated by SDS-PAGE and silver-stained showed some differences in polypeptide patterns. Western-blot analysis revealed that these differences were not related to antigenic polypeptides but were most likely caused by substances without antigenic properties originating from dead and/or degenerating larvae. It can be concluded that ES antigens produced by previously frozen larvae are essentially the same as those derived from unfrozen controls. The value of cryopreservation of T. canis larvae for routine production of ES antigens will be further evaluated.

Animals↗