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Biomedical subjects

M Suter

Publications and source records attributed to M Suter.

At least 163 records · Page 9Linked to original sources
PubMed1983

Further purification and characterisation of horse IgE.

Horse IgE was isolated from a serum pool collected from foals naturally infected with endoparasites. The serum was precipitated with ammonium sulfate, delipidated with dextran sulfate and further purified by gel filtration, anionic exchange, immunosorption or preparative polyacrylamide gelelectrophoresis. By these methods IgE could be isolated at a purity of 81%. The sera from rabbits immunized with the purified horse serum fractions were tested using reversed passive cutaneous anaphylaxis and an enzyme linked immunosorbent assay (ELISA). By the ELISA method cross reaction of rabbit anti horse IgE sera to human, mouse and rat myeloma IgE was demonstrated. Rat myeloma IgE also served to monitor the production of antibodies to horse IgE in rabbits.

Animals↗
PubMed1983

Allergen-specific ELISA for horse IgE.

An enzyme-linked immuno sorbent assay (ELISA) for measuring horse IgE specific to ovalbumin, bencylpenicilloic acid and odinitrocarboxyphenol is described. We used a sandwich type of ELISA by which horse serum was incubated in antigen-coated tubes containing one additional polystyrene ball, followed by rabbit anti horse IgE serum. The tubes were then incubated with biotinylated goat anti rabbit globulin followed by avidin coupled to phosphatase. Endpoint titrations were compared. The ELISA is highly reproducible due to the pretreatment of the polystyrene with glutaraldehyde. The increased antigen surface area led to a higher sensitivity of the test. The assay can be easily modified for the measurement of other Ig classes and of IgE of other antigen specificities.

Animals↗
PubMed1983

Histological immunoenzyme techniques in canine tissues: evaluation of various methods and modifications.

Several antigens including immunoglobulin light and heavy chains, C3, macrophage enzymes and various brain proteins were demonstrated immunohistologically in paraffin sections of canine tissues. The indirect immunoperoxidase, the unlabelled antibody enzyme (PAP), double bridging PAP, and biotinavidin-peroxidase (BAP) methods were compared. The influence of various histological procedures such as fixation and embedding, and other modifications such as enzyme treatment of sections was investigated. The best results were obtained with the PAP and BAP methods on formalin fixed tissues. Trypsin proved to be highly effective for demonstrating certain antigens but required firm adhesion of the sections. Prolonged incubation with the primary antisera improved the results considerably. Based on the results of this study a general strategy for solving immunohistological problems has been proposed.

Animals↗
PubMed1982

A modified ELISA technique for anti-hapten antibodies.

Polystyrene tubes pretreated with glutaraldehyde in phosphate buffer were used in a solid-phase enzyme-linked immunoassary (ELISA). The hapten o-dinitrocarboxyphenol (o-DNCP) was used as coat. The binding of homologous rabbit antibodies was measured with phosphatase-labelled staphylococcal protein A (SPA-PH). This method is both very sensitive (serum dilutions greater than 2 x 10(-6) were still positive) and highly reproducible. Anti-DNP rat IgE was detected with o-DNCP hapten as a coat using avidin/biotin as a marker.

Animals↗
PubMed1981

The hexa- and pentapeptide extension of proalbumin. II. Processing of specific antibodies against the synthetic hexapeptide.

The chemically synthesized proalbumin hexapeptide was coupled to rabbit albumin with carbodiimide. Subsequently rabbits were immunized by subcutaneous injection of the conjugate. After 5 weeks the rabbits had developed antibodies against the hexapeptide, which could be detected by immunodiffusion. A sensitive enzyme-linked immunosorbent assay was developed. Using the hexapeptide and other very similar peptides as antigens, a high specificity of the antibodies against the proalbumin hexapeptide was found.

Animals↗
PubMedDate not supplied

Comparison of the antibody response to bee venom phospholipase A2 induced by natural exposure in humans or by immunization in mice.

Two human and twelve murine monoclonal antibodies directed against the main bee venom allergen phospholipase A2 (PLA) were evaluated for their fine specificity of binding to antigen and their ability to inhibit the enzymatic activity of the antigen. Antibodies were induced by natural exposure of beekeepers to bee venom or immunization of mice via different methods. Both human monoclonal antibodies (hmAbs) were previously shown to recognize the native three-dimensional conformation of PLA and are directed against discontinuous epitopes which include lysine residue at position 25 as a contact residue. In contrast, six of the murine monoclonal antibodies (mmAbs) bind to the denatured structure of the protein as determined by enzyme-linked immunosorbent assay. The epitopes recognized are located near the C-terminal end (n = 8), in the centre of the polypeptide (n = 1), near the N-terminal end (n = 1) or include the carbohydrate part (n = 2) of the PLA molecule. The capacity of the antibodies to modify the enzymatic activity was also determined. The hmAbs significantly inhibit the enzyme (70-79%), whereas the mmAbs produced various degrees of inhibition (39-100%). Since the X-ray structure of PLA is known, the epitopes can be visualized in the context of the three-dimensional structure of the antigen. A qualitative correlation was found between the location of epitopes and the inhibition pattern. Strong inhibition was seen with those antibodies that recognize epitopes that lie on the surface of the enzyme that is thought to contact the phospholipid bilayer. The results show that even though both hmAbs and most mmAbs inhibit the enzymatic activity of PLA, the antigen-binding properties of antibodies from different species raised after different routes of immunization differ significantly. Thus, detailed epitope mapping studies using murine antibodies prepared by artificial immunization may have limited value in predicting epitope patterns relevant to an antibody response to allergens in humans naturally exposed to antigen/allergen.

Allergens↗
PubMedDate not supplied

[Suspense-dust-, lead- and benzpyrene emissions in the city of Zurich].

Levels of particulate matter, lead and benzo(a)pyrene were measured during 1971--1976 at different monitoring stations in Zurich. Annual averages in city proper ranged between 90 and 180 microgram/m3 for particulate matter, 2 and 3 microgram/m3 for lead and between 6 and 7 ng/m3 for benzo(a)pyrene. Corresponding values for the suburbs as well as for the village of Netstal were about 1/3 to 1/2. Winter levels were higher than the summer ones at all the sites. These differences were more obvious in case of calms. Ambient concentrations of particulate matter and lead measured in the city center were similar to those measured in german cities and were in the same range as air quality standards. Primary attention should be paid to the reduction of emissions, as surveillance of space heating and incineration equipment, and the reduction of lead in fossil fuels.

Air Pollution↗
PubMedDate not supplied

A crucial role for B cells in neuroinvasive scrapie.

Although prion proteins are most efficiently propagated through intracerebral inoculation, peripheral administration has caused the diseases kuru, iatrogenic Creutzfeldt-Jakob disease (CJD), bovine spongiform encephalopathy (BSE) and new-variant CJD. The development of neurological disease after peripheral inoculation depends on prion expansion within cells of the lymphoreticular system. Here we investigate the identity of these cells by using a panel of immune-deficient mice inoculated with prions intraperitoneally: we found that defects affecting only T lymphocytes had no apparent effect, but that all mutations that disrupted the differentiation and response of B lymphocytes prevented the development of clinical scrapie. As an absence of B cells and of antibodies correlates with severe defects in follicular dendritic cells, a lack of any of these three components may prevent the development of clinical scrapie. However, we found that scrapie developed after peripheral inoculation in mice expressing immunoglobulins that were exclusively of the M subclass and without detectable specificity for the normal form of the prion PrPC, and in mice which had differentiated B cells but no functional follicular dendritic cells. We conclude that differentiated B cells are crucial for neuroinvasion by scrapie, regardless of the specificity of their receptors.

Animals↗
PubMedDate not supplied

Neospora caninum infection in English Springer Spaniel littermates. Diagnostic evaluation and organism isolation.

Progressive paraparesis developed in four male English Springer Spaniel pups from a litter of five during the first 10 weeks of life. Two of the pups, which had the earliest onset of neurologic signs, were euthanatized without further workup. However, a detailed investigation was completed on the remaining two littermates at 12 weeks of age. Both pups had progressive paraparesis for 3 to 4 weeks before presentation, with one dog developing subsequent asymmetric pelvic limb extensor rigidity. Based on results from neurologic examination, cerebrospinal fluid (CSF) analysis, electrophysiology, and muscle/nerve biopsy, a presumptive diagnosis of protozoal polyradiculitis and polymyositis was made. Necropsy of the most severely affected pup confirmed the clinical diagnosis of inflammatory nerve root and muscle disease but no organisms were found. To increase the potential yield of organisms, the second pup was placed on immunosuppressive doses of corticosteroids and euthanatized 2 weeks later. Numerous organisms were found in lesions in muscle and the central nervous system. Organisms grew in tissue culture and were isolated from the peritoneal fluid of gerbils inoculated with infected tissue. Organisms were not isolated from inoculated mice, guinea pigs, rabbits, and hamsters. No parasites were seen in feces or tissues of three cats fed infected dog tissues. Serologic testing demonstrated a strong positive titer to Neospora caninum in both pups, and electron microscopy showed the characteristic morphology of this parasite.

Animals↗