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Biomedical subjects

E Geyer

Publications and source records attributed to E Geyer.

At least 37 records · Page 2Linked to original sources
PubMed1990

Purification of an antigen from the Taenia crassiceps metacestode vesicular fluid highly sensitive in detecting IgG-antibodies (ELISA) in calves with experimental cysticercosis.

This study reports on the purification of an antigen predominant within the vesicular fluid (VF) of T. crassiceps metacestodes and shown to share identity with the major vesicular fluid protein of the T. saginata larval stage. Purification was achieved by gel filtration of the VF on Sephacryl S-300 superfine, followed by ion exchange HPLC. The antigen represents a single polypeptide chain (Mr appr. 37,000) with carbohydrate moieties without affinity to ConA. Isoelectric focusing of the electrophoretical and immunological homogeneous antigen resulted in five bands focusing at pH 4.0, 4.2, 4.4, 4.6 and 4.8, respectively. In ELISA, the purified antigen detected serum IgG-antibodies in all 21-35 weeks old calves (n = 10) with experimental cysticercosis (70 to 6,000 viable larvae recovered). When compared to T. saginata metacestode VF the antigen was the better reagent for discriminating between infected and non-infected animals. As shown by immunodiffusion and ELISA the antigen is also common to the T. saginata adult stage and obviously to other taeniid metacestodes where it is accumulated in the VF or hydatid fluid.

Animals↗
PubMed1990

Regional cooperative summer internship program for pharmacy students.

A regional summer internship program for pharmacy students that was coordinated by seven hospitals is described. Recruiting for the Mid-Missouri Summer Intern Program began during the winter of 1987-88. Students were recruited from pharmacy schools throughout the Midwest and were provided with housing and financial compensation while in the program. Each participating hospital agreed to hire at least one intern and appointed a preceptor or coordinating pharmacist, who met with the intern regularly. Students got most of their training and work experience at their home hospital; however, they also rotated to the other participating hospital pharmacy departments. Students had to keep a daily diary of their activities and to complete individual special projects. At the end of the summer, students and preceptors completed a written evaluation of the program. Students indicated that the program provided a valuable and unique educational experience. Preceptors thought that fourth-year and fifth-year students were best suited for the program. The hospital pharmacy directors agreed that the opportunity to evaluate a student's work ethic and professional capabilities before offering a position was a benefit. A regional summer internship program was successful in introducing pharmacy students to institutional pharmacy practice.

Curriculum↗
PubMed1989

Immunoelectrophoretic analyses of antigens shared by the vesicular fluid and cyst wall of Taenia crassiceps and Taenia saginata metacestodes.

In this study, the antigenic mosaic of the vesicular fluid (VF) and hydrosoluble cyst-wall extract (CWE) of T. crassiceps (Tc; harvested from mice) and T. saginata (Ts) metacestodes was analyzed by combined precipitation maps developed in single and bidimensional immunoelectrophoresis against the respective rabbit antiserum. Host-serum proteins demonstrated by immunodiffusion within TcVF (albumin, transferrin, IgG, and another five noncharacterized proteins), TcCWE (albumin, IgG, and six additional unknown proteins), TsVF (albumin) and TsCWE (albumin and IgG) were removed by immunoaffinity chromatography prior to immunoelectrophoretic analysis. Neither TcVF nor TcCWE contained demonstrable amounts of mouse IgM and IgA. In TcVF a total of 18 and in TcCWE a total of 36 parasitic antigens were recognized by the corresponding antiserum. In the case of TsVF and TsCWE, antiserum to the crude extract of T. saginata larvae developed a total of 26 and 30 precipitates, respectively. Examination of the precipitation maps developed by the respective heterologous antiserum (vice-versa testing) showed that both TcVF and TsVF contained ten antigens sharing identity. For TcCWE and TsCWE, nearly the same number of shared antigens (20 and 18, respectively) could be demonstrated. For screening of IgG antibodies against T. saginata metacestodes from heavily and moderately infected calves (n = 6) by ELISA, VF and CWE antigens of both Taenia species were found to be potent reagents; TsVF was the most sensitive antigen.

Animals↗
PubMed1989

Taenia crassiceps metacestode vesicular fluid antigens shared with the Taenia solium larval stage and reactive with serum antibodies from patients with neurocysticercosis.

After removal of host (mouse) serum proteins (albumin, transferrin, IgG and another five unidentified proteins) by immunoaffinity chromatography, the vesicular fluid of T. crassiceps metacestodes (TcVF) was immunoelectrophoretically examined for antigens recognized by rabbit antiserum to aqueous crude extract of T. solium cysticerci. Based on a precipitate pattern developed in electroimmunodiffusion, nine cross-reactive antigens could be demonstrated. In the ELISA, TcVF was shown to be a potent antigen for the demonstration of IgG antibodies in the sera of Mexican patients (n = 14) with confirmed neurocysticercosis (mean E490 values +/- SD: 0.39 +/- 0.38) although it was less sensitive when compared to T. solium VF (0.95 +/- 0.54). Sensitivity was much higher using cross-reactive TcVF antigens selected by immunoaffinity chromatography with rabbit IgG antibodies to larval T. solium crude extract (0.87 +/- 0.57). SDS-PAGE fluorograph of cross-reactive, radioiodinated TcVF protein antigens and selected by antibodies of individual neurocysticercosis sera (n = 13), exhibited six to nine bands depending on the serum tested. Altogether ten 125I-labelled proteins (Mr range from about 20,000 to 200,000) were recognized by neurocysticerosis antibodies. Four proteins (Mr about 22,000, 25,000, 32,000 and 45,000) were detected by all sera.

Animals↗
PubMed1989

Inhibition of in vitro and in vivo mast cell degranulation by Taenia crassiceps metacestodes in vitro incubation products.

In vitro released products of T. crassiceps metacestodes (TcIP) harvested from the peritoneal cavity of NMRI mice were tested for inhibitory effects on the in vitro degranulation of peritoneal mast cells (MCs) of normal mice (NMRI) and rats (Wistar) and on the in vivo degranulation of rat (Wistar) skin MCs (PCA-assay). In vitro degranulation was elicited chemically (compound 48/80, polymyxin B or the bee venom peptide, mellitin). In vivo degranulation was triggered immunologically (anaphylactic systems ovalbumin/anti-ovalbumin or Fasciola hepatica crude fluke extract antigen/serum of fluke-infected rats (Wistar]. In vitro degranulation of murine peritoneal MCs or the in vitro histamine release of rat peritoneal MCs normally induced chemically was significantly inhibited when the MCs were preincubated with the TcIP or with serum of T. crassiceps-infected NMRI mice from day 35 post infection and thereafter. In vitro degranulation of peritoneal MCs of infected mice was strongly inhibited beginning on day 10 after infection. Also in vivo degranulation of the IgE-sensitized rat skin MCs was significantly reduced by intradermal injection of the TcIP before (6, 3 and 1 h) antigen challenge and by preinjection (1 h) of serum from infected mice (day 80 p.i.)-The inhibitory effect was also demonstrated after immunoadsorption of mouse serum proteins naturally contaminating the TcIP. Heating (100 degrees C/15 min), even in the presence of 0.25 M HCl, did not suppress the inhibitory activity.

Animals↗
PubMed1988

Comparison of the in vitro translation capacity of Taenia crassiceps metacestode mRNA prepared by the phenol and cesium chloride method.

Total RNA of T. crassiceps metacestodes harvested from male and female NMRI mice was prepared by both the phenol extraction technique and cesium chloride (CsCl) gradient centrifugation. mRNA was selected by oligo (dT)-cellulose affinity chromatography and used as the template for the in vitro translation of parasite polypeptides in a cell-free rabbit reticulocyte lysate. The template activity of the mRNA obtained after CsCl preparation was clearly higher, as shown by the amount of 35S-methionine incorporated into the translation products and by fluorographed SDS-PAGE of the synthesized labelled polypeptides. SDS-PAGE fluorographs of antigens encoded by the mRNA prepared by CsCl centrifugation and selected by immunoprecipitation using purified IgG antibodies of T. crassiceps-infected mice (day 80 postinfection) exhibited seven labelled polypeptides of about 65, 46, 45, 42, 34, 29 kDa and a predominant 20-kDa antigen. The latter polypeptide was the only one recognized by the antibodies amongst the in vitro translation products directed by mRNA prepared by the phenol method.

Animals↗
PubMed1984

Serodiagnosis of human onchocerciasis: evaluation of sensitivity and specificity of a purified Litomosoides carinii adult worm antigen.

Sensitivity and specificity of a Litomosoides carinii macrofilariae aqueous crude extract and a purified antigen which was isolated by preparative flat bed electrofocusing, were evaluated for the immunodiagnosis of human onchocerciasis in 3 serological tests: Double diffusion test (DT), latex agglutination test (LAT) and ELISA. Testing sera from proven cases of onchocerciasis (n = 28), loiasis (n = 4) filariasis bancrofti (n = 4), and other non filarial helminth infections (n = 29) in all tests the purified antigen was clearly more sensitive and specific. Testing onchocerciasis sera highest sensitivity was found by ELISA (92.9%) followed by latex agglutination test (89.3%) and double diffusion test (82.1%). Specificity controls of the purified antigen with sera from patients with helminth infections others than filariases led to 0% (DT), 6.9% (LAT) and 10.3% (ELISA) false positive reactions. When the 3 tests were used in combination in a way that at least two positive reactions in different tests were regarded as necessary to declare a serum as positive, sensitivity increased to 100% and unspecific reactions were found only testing one serum (3.4%) originating from a case of cystic echinococcosis.

Antibodies↗
PubMed1983

Isolation of antigen from Litomosoides carinii macrofilariae detecting serum antibodies due to Onchocerca volvulus.

Crude aqueous Litomosoides carinii adult worm extract was used as antigen for the detection of antibodies in sera from African patients with proven onchocerciasis (n = 45) resident in rural endemic areas of Togo and Sierra Leone. In 71% of cases this extract was found to produce 1 to 5 precipitation arcs in immunoelectrophoresis. Using a crude aqueous extract from adult Onchocerca volvulus, precipitation tests were positive in 75% of cases. The complexity of the L. carinii crude extract was shown by PAG-disc electrophoresis, PAG-electrofocusing, immunoelectrophoresis and crossed immunoelectrophoresis with the appropriate rabbit-antiserum. An antigen detecting onchocercal antibodies was isolated by two step preparative flat bed electrofocusing in granulated gel (PEGG). The antigen (pI 6.55, molecular weight 55 to 60 kd as estimated by SDS-PAG electrophoresis) was very suitable for antibody demonstration in double diffusion test and immunoelectrophoresis. Preliminary controls for specificity were performed by diffusing the antigen against sera from human and animal helminthoses including filarial infections. In contrast to the crude L. carinii extract no reaction was observed with sera from helminthic infections others than filariasis.

Animals↗
PubMed1981

Experimental dicrocoeliasis: the humoral immune response of golden hamsters and rabbits to primary infection with Dicrocoelium dendriticum.

The results presented deal with the humoral immune response of golden hamsters to primary experimental infection with D. dendriticum. The development of serum antibodies has been comparatively investigated with three hamster groups (n = 43) harbouring different burdens of adult flukes. The mean numbers of parasites were 11, 30, or 130 per animal. Serum antibody response was studied during an observation period of at least 331 and up to 496 days postinfection. For antibody detection the sensitivities of precipitation test (PTs) (double diffusion test, immuno- and counterimmunoelectrophoresis), of the indirect haemagglutination test (IHAT), the complement fixation test (CFT), and the enzyme linked immuno sorbent assay (ELISA) were compared using aqueous crude fluke antigen and crude egg antigen. CFT and ELISA were most sensitive for the early detection of initial response. Thereafter all the tests employed revealed increasing antibody titres, which in general remained at constant levels and persisted until the end of the observation period with the exception of CF-antibodies. In general fluke antigen was found to be more sensitive than egg antigen. However, in CFT this antigen occasionally has been associated with unspecific inhibition of haemolysis. Comparison of the results shows that ELISA using crude fluke antigen gave the most realistic picture of the actual fluke burden. Also preliminary results on the precipitin response of rabbits (n = 3) after primary experimental exposure to different numbers of metacercariae (500, 1,000, and 3,000 per animal respectively) are reported. Employing the above mentioned PTs a persisting antibody response could be demonstrated only after exposure to at least 3,000 infective larvae. The initial response was found on day 63, the observation period was 550 days.

Animals↗
PubMed1980

[Immunization against Capillaria hepatica: the effects of primary infections, x-irradiated stages, non-embryonated eggs, and soluble egg extracts (author's transl)].

The influence of primary infections with embryonated infective eggs or with X-irradiated infective eggs, and of non-embryonated eggs, and egg homogenate extracts on challenge infections with Capillaria hepatica was investigated. The worm reproductivity was significantly suppressed in a sublethal challenge infection given 11 days after a primary infection of Mastomys natalensis with 50, 150, 400, and 800 eggs per animal. The administration of 600 X-irradiated (2.2 Krd) embryonated eggs 36 days before challenge as well as an intraperitoneal injection of non-embryonated eggs 12, 10, 8, 6, 4, and 2 days before challenge (simulating the egg production of a normal infection) also reduced significantly the egg production of a weak (50 eggs/ animal) infection. No effect was observed on a moderate challenge (300 eggs/animal). The effect was not markedly enhanced by the repeated administration of X-irradiated eggs or by the combination of X-irradiated infective eggs and non-embryonated eggs. Immunization of mice with soluble egg extracts resulted in significant reduction of egg production determined 60 days after challenge. Two hundred and thirty eggs of C. hepatica/g body weight proved to be a lethal infection dose for M. natalensis. The animals died between 20 and 35 days after infection. After single infections with 50, 150, 400, or 800 eggs per animal the mortality of Mastomys challenged 36 or 52 days later was reduced to 0--30%. Using X-irradiated embryonated eggs for immunization only repeated administration led to protection in 70 to 80% of the animals. About 40% of the animals could be protected by the intraperitoneal injection of non-embryonated eggs. If death occurred it was delayed. The combination of X-irradiated stages and eggs did not enhance the protection.

Animals↗
PubMed1980

Quantitative estimation of cellular retinoic acid-binding protein activity in normal, dysplastic, and neoplastic human breast tissue.

A technique for reproduction and quantitative determination of human cellular retinoic acid-binding protein (CRABP) activity in breast tissue specimens is described. A multiphasic polyacrylamide disc gel electrophoresis system (operative at pH 10.2) was adapted for this purpose. This technique allows, after incubation with tritiated retinoic acid (RA) overnight, the separation of the specific CRABP activity from the nonspecific serum-originated binding activity and from the free RA. Previous purification of the tissue cytosols is therefore not necessary. The same assay method was also used for the determination of the molecular weight (Ferguson plot, m.w. 13,000) and the dissociation constant Kd (2.5 x 10(-7) M) of mammary CRABP. The activity in tissue cytosol, stored at -70 degrees, was found to be stable for at least 3 months. Results from 88 breast tissue specimens of different pathological degree are presented. CRABP activity was found in all tissue categories with progressively increasing amounts from normal tissue to breast cancer. The activity in the cancer tissues (14.85 +/- 12.05 pmol RA bound per mg soluble protein: N = 27) was significantly different (p less than 0.001) from the activity determined in tissue with simple dysplasia without epithelial proliferation [4.3 +/- 2.2 (S.D.) pmol RA bound per mg protein; N = 30]. It is possible that in the cases where high amounts of CRABP activity are found in dysplastic and preneoplastic tissue, a high risk for breast cancer development exists. Therefore, CRABP is tentatively proposed as a dedifferentiation and/or proliferation marker.

Adolescent↗
PubMed1978

Retinoic acid-binding protein in human breast cancer and dysplasia.

Seventy-five specimens of human breast tissue were checked for the presence of cellular retinoic acid-binding protein (cRABP). Fifty-two percent of the primary carcinomas and 43% of the dysplastic breast lesions (stage MII) contained detectable amounts of crabp, whereas no cRABP was found in normal tissue. Sucrose gradient centrifugation and electrophoresis on agarose were used for analysis of the presence of cRABP. The cRABP of human origin (normal uterus and neoplastic mammary tissue) differed in its mobility in agarose electrophoresis from that of rat testis cRABP.

Animals↗