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R Pierce

Publications and source records attributed to R Pierce.

69 records · Page 4Linked to original sources
PubMed1984

Rat IgE directed against schistosomula-released products is cytotoxic for Schistosoma mansoni schistosomula in vitro.

The immunogenicity of molecules shed by schistosomula into culture medium (antigens present in schistosomula-released products, SRP-A) has been studied. The results obtained show that SRP-A preferentially induce an IgE response when injected into rats, without the need for adjuvants. Moreover, anti-SRP-A IgE is cytotoxic in vitro for the larvae in the presence of macrophages, eosinophils or platelets, which have previously been demonstrated as being the three efficient killer cells for schistosomula in the presence of specific IgE. Immunofluorescence analysis locates the target antigens at the schistosomulum surface. Among the antigens recognized by anti-SRP-A IgE, two molecules of 26 and 22 kDa have been identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by western blotting.

Animals↗
PubMed1983

Detection of IgE antibodies in onchocerciasis using a semi-purified fraction from Dipetalonema viteae total antigen.

A Dipetalonema viteae extract was separated by gel filtration on ACA 34 Ultrogel into four fractions (A, B, C and D). The allergenic activity of the D. viteae extract and its various fractions was assayed by the passive cutaneous anaphylaxis (PCA) test in rats using mouse sera obtained from Balb/c mice transplanted with D. viteae. The PCA reaction showed that fraction B was the most potent allergenic fraction of the D. viteae extract. By the radioallergosorbent test (RAST) the use of fraction B coupled to CNBr-activated paper discs showed elevated binding of IgE antibodies in onchocerciasis human sera. A comparative study demonstrated the efficiency of the above fraction in the RAST technique in distinguishing between Onchocerca volvulus-infected patients and those infected with other human filarial worms or other helminth parasites. The binding of IgE to fraction B was confirmed by the radioimmunoelectrophoresis and radio-double diffusion methods using an 125I anti-human IgE. Since D. viteae antigens are more readily obtainable than those of O. volvulus, a further purification of fraction B to improve its specificity for the detection of IgE antibodies in human onchocerciasis is warranted.

Allergens↗
PubMed1982

Neutral protease activities at different developmental stages of Schistosoma mansoni in mammalian hosts.

Neutral protease activities of schistosomula, 20 day old and adult worms of S. mansoni have been studied. 1. The neutral enzymes of the three development stages are able to hydrolyse numerous natural and synthetic substrates. 2. The enzymes of homogenates and saponin CaC12 extracts show significant discrepancies in their specificities, optimum pH activities and in the effects of enzyme inhibitors. 3. A serine protease activity was specific for the schistosomula stage whereas thiol proteinases characterize the later stages of evolution. A metalloaminopeptidase activity was shown at all three stages. 4. Gel filtration chromatography and isoelectric focusing of an adult worm homogenate demonstrated the presence of at least 5 caseolytic and 4 azocollytic neutral activities. Three aminopeptidases, one of which exhibited iminopeptidase specificity were revealed by the same procedure.

Aminopeptidases↗
PubMed1980

Skin tests with tuberculin (PPD) Candida albicans and Trichophyton spp. in cryptogenic fibrosing alveolitis and asbestos related lung disease.

Delayed skin hypersensitivity responses were elicited in patients with cryptogenic fibrosing alveolitis (CFA) (twenty-eight), asbestosis (eight), mesothelioma (eight) and a "control" group, having miscellaneous lung diseases not normally believed to be associated with T cell deficiency (twenty). Three antigens, Candida albicans, trichophyton and purified protein derivative (PPD) in a range of doses were used. There was no evidence of impaired cellular immunity in CFA or in mesothelioma, indeed there was a significantly increased frequency of reactions to PPD in both of these conditions (P less than 0.05 and P less than 0.01 respectively). There was, however, a trend of decreased responsiveness in the group with asbestosis. The dosage regimen used rarely gave completely negative results (only one of thirty-two completed tests), and may provide a basis for a simple and standard regimen for screening patients suspected of having defective T cell responses.

Adolescent↗
PubMedDate not supplied

Gait changes in children with spastic diplegia after selective dorsal rhizotomy.

Twenty-six ambulatory children underwent preoperative and 1-year postoperative assessments after selective dorsal rhizotomy. These included spasticity, passive range of motion, tone, three-dimensional motion analysis, and electromyography. Independent and dependent ambulators were evaluated separately. A decrease in spasticity was found in all lower extremity muscle groups. An increase in passive range of motion was found only at the hip for both independent and dependent ambulators. Gait changes included increases in velocity and stride length in the independent ambulators. An improvement in hip extension during stance was found in the dependent ambulators only; however, an increase in knee extension and dorsiflexion in stance were seen in both groups. Selective dorsal rhizotomy improves both passive and dynamic range of motion in children with spastic diplegia.

Cerebral Palsy↗
PubMedDate not supplied

Development of a vaccine strategy against human and bovine schistosomiasis. Background and update.

Schistosomiasis is a chronic and debilitating parasitic disease that affects over 200 million people throughout the world and causes about 500,000 deaths annually. Two specific characteristics of schistosome infection are of primordial importance to the development of a vaccine: schistosomes do not multiply within the tissues of their definitive hosts (unlike protozoan parasites) and a partial non-sterilizing immunity can have a marked effect on the incidence of pathology and on disease transmission. Since viable eggs are the cause of disease pathology, a reduction in worm fecundity whether or not accompanied by a reduction in parasite burden is a sufficient goal for vaccine induced immunity. We originally showed that IgE antibodies played in experimental models a pivotal role for the development of protective immunity. These laboratory findings have been now confirmed in human populations. Following the molecular cloning and expression of a protein 28 kDa protein of Schistosoma mansoni and its identification as a glutathion S-transferase, immunization experiments have been undertaken in several animal species (rats, mice, baboons). Together with a significant reduction in parasite burden, vaccination with Sm28 GST was recently shown to reduce significantly parasite fecundity and egg viability leading to a decrease in liver pathology. Whereas IgE antibodies were shown to be correlated with protection against infection, IgA antibodies have been identified as one of the factors affecting egg laying and viability. In human populations, a close association was found between IgA antibody production to Sm28 GST and the decrease of egg output.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗