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K Willms

Publications and source records attributed to K Willms.

31 records · Page 2Linked to original sources
PubMed1987

Histological and ultrastructural localization of antigen B in the metacestode of Taenia solium.

The morphological localization of antigen B (AgB) in the tissues of the Taenia solium metacestode was studied by immunological and biochemical methods. Indirect immunofluorescence carried out on vibratome sections showed that AgB is widely distributed throughout the tissue. A more intense fluorescence was observed in the tegumentary cytons of the bladder wall and in the lumen of the spiral canal of the invaginated scolex. Ultrastructural analysis of larvae washed in PBS after dissection from meat and then incubated with rabbit antibodies against AgB, followed by peroxidase-labeled goat anti-rabbit IgG, did not exhibit electron-dense material on the external surface. Larvae fixed in glutaraldehyde immediately after dissection and exposed to the immunoperoxidase reagents did exhibit electron-dense material on microtriches, indicating that AgB is only loosely bound to the external surface. Crude extracts of surface-radioiodinated cysticerci analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) contained no labeled proteins with the molecular weight of AgB. Autoradiography of the immunoelectrophoretograms in which the crude extract was confronted with antibodies to AgB demonstrated that this antigen was not labeled, and therefore is not exposed on the tegumentary surface. The results suggest that AgB is synthesized by the tegumentary cytons of the parasite and secreted through the tegumental membrane into the host tissues and the lumen of the spiral canal.

Animals↗
PubMed1986

Inhibition of mitogenesis induced by phytohemagglutinin and Lens culinaris lectin in adherent-cell supernatants treated with protein extract of Mycobacterium tuberculosis.

Specific stimulation of T cells by phytohemagglutinin and Lens culinaris lectin was inhibited by a soluble factor(s) secreted by normal adherent cells stimulated with culture filtrate protein extract (CFPE) derived from bacterial cultures of Mycobacterium tuberculosis H37Ra (avirulent) and H37Rv (virulent). The induction of the inhibitory factor was blocked by the presence of hyperimmune antisera to H37Rv or H37Ra CFPE. The inhibitory factor did not seem to be a CFPE reprocessed by the adherent cells. Inhibitory activity was maximal in supernatants of adherent-cell cultures incubated for 48 h; the inhibitory factor was heat labile, and its production was dependent on the concentration of M. tuberculosis CFPE. A mouse monocyte-macrophage cell line, ATCC J774A.1, produced an identical inhibitory factor, thus excluding a non-macrophage-contaminating adherent cell as the source of the factor. This inhibitory factor also interfered with the recognition of phytohemagglutinin and Lens culinaris lectin by T cells.

Animals↗
PubMed1981

Taenia solium: mitogenic effect of larval extracts on murine B lymphocytes.

The effect of an extract (CE) obtained from Cysticercus cellulosae on the proliferation of lymphocytes was studied in cultures of murine spleen cells. The addition of CE to the cultures resulted in the highly significant uptake and incorporation of tritiated thymidine (3H-TdR) into DNA. This phenomena was dose-dependent, with doses lower and higher than the optimal concentration causing less marked effects. The kinetic peak of this response was found to occur on day 2 of culture. CE evoked a proliferative response in cultures of spleen cells from congenitally athymic (nu/nu) BALB/c mice. Cultures of bone marrow-derived (B) lymphocytes, generated by treatment of spleen cells with rabbit antithymocyte serum and complement, incorporated 3H-TdR to a degree similar to that of normal spleen cell cultures. CE did not induce the proliferation of thymocytes. To eliminate the possibility that the mitogenic effect of CE was due to LPS, we carried out experiments using Polymyxin B (PB). CE was mitogenic after treatment with PB which inactivated the LPD effect. In addition, CE elicited 3H-TdR uptake in spleen cells from the LPS nonresponsive C3H/HeJ mouse strain.

Animals↗
PubMed1980

The inflammatory reaction surrounding Taenia solium larvae in pig muscle: ultrastructural and light microscopic observations.

An inflammatory reaction with the general characteristics of a chronic granuloma surrounding Taenia solium larvae in pig muscle is described. Larvae with an inflammatory capsule were obtained at slaughter from pigs 6-8 months-of-age and were processed for light and electron microscopy. Eosinophils (granulocytes with orange staining and peroxidase-positive granules) were found to be degranulated and in close contact with the parasite surface. Histiocyte, epithelioid cells, macrophages and lymphocytes were also evident, as well as large numbers of plasma cells in the outer areas of the wall-circumscribed reaction. The parasites were ultrastructurally intact, with a normal tegument and only occasional changes in the microvesicles. The results are discussed with reference to parasite survival in the host.

Animals↗
PubMed1975

[Immunoelectrophoresis and double immunodiffusion in the diagnosis of human cerebral cysticercosis].

This paper describes the immune reactivity of the sera of humans with different probabilities of suffering cerebral cysticercosis as measured in immunoelectrophoresis and double diffusion against antigenic fractions from the wall, the liquid and the scolex of Cysticercus cellulosae. The proportion of positive sera with any antigenic fraction increased with the likelyhood of suffering cerebral cysticercosis, although some variation was found between antigenic fractions. Scolex and wall antigens showed the maximal discriminatory power between sick and healthy individuals: the probability of a false positive being less than 0.05 and that of a false negative ranging between 0.4 and 0.5. With these estimates it is concluded that a positive serum in immunoelectrophoresis or double diffusion against scolex or wall antigens practically establishes the diagnosis of cerebral cysticerocosis, although this event will occur in only half of the patients afflicted by the disease. The ease of execution of these tests and their discriminatory power between healthy and sick humans justify their establishment among diagnostic tools in cerebral cysticercosis.

Antigen-Antibody Reactions↗
PubMedDate not supplied

Serology as an indicator of Taenia solium tapeworm infections in a rural community in Mexico.

Serial stool examinations were carried out on a sample of 516 persons living in the town of El Salado (1993 inhabitants). In a group of 40 families (198 individuals), selected by random sampling, there were 2 cases of Taenia solium infection (1.2%); an additional group of 67 families (318 individuals), who volunteered for the study, had 4 cases (1.1%). 5 of the 6 T. solium cases were clustered in 4 neighbouring households. Serum antibodies to the larval stage of T. solium were detected by ELISA using bladder fluid as antigen. 22 members of the random sample group were positive (11%); 58 persons of the total sample of 478 were positive (12%). 43% of individuals living in the same household as a T. solium-infected person were positive, compared to 8.6% seropositive individuals among those not known to have been in daily contact with a T. solium carrier. Odds ratio analysis of the random and total samples showed that the risk of being seropositive when living in the same household as a tapeworm carrier was 9.05 and 6.85 respectively. The results showed a significant correlation between T. solium tapeworm clusters and higher seropositivity rates among contacts rather than among non-contacts. The immune response is a sensitive indicator of a tapeworm infection in a household or family, and is easier to determine than the traditional search for taeniid eggs in stool, a method which is difficult to apply in developing countries due to lack of trained personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Taenia solium: germinal cell precursors in tapeworms grown in hamster intestine.

BACKGROUND: In a previous study, it was shown that growth of evaginated metacestodes occurs in the germinative tissue of the neck by duplication of somatic stem cells. In these specimens, it was not possible to find the mitotic figures required to demonstrate duplication of germ cell lines. METHODS: Taenia solium strobilae were collected from the intestinal lumen of outbred hamsters infected orally with 10 metacestodes dissected from naturally infected pigs. Animals were anesthetized 1-10 days postinfection, the small intestine excised, submerged in PBS, and cut open longitudinally. Live Taenias were incubated for 6-8 h in medium containing colchicine or 3H-thymidine, washed, and embedded for electron microscopy. For light microscopy and autoradiography, longitudinal sections were cut from whole blocks and mounted on glass slides. A population of large cells without nuclear membranes and containing discrete aggregates of chromatin were observed apposed to myofibrils in the germinative tissue of the neck. These cells were confirmed by electron microscopy as metaphase mitotic figures, with chromosomes attached to a microtubular spindle, embedded in cytoplasm, without a nuclear membrane, and with characteristic centrioles. RESULTS: Only tapeworms in which 3H-thymidine was injected directly into the worm tissue by microsyringe were positive by autoradiography, demonstrating that in contrast to evaginated metacestodes, intestinal worms do not transport thymidine across the tegument. CONCLUSIONS: The results show that differentiating T. solium worms have a subset of stem cells that require passage through a mammalian host to go into mitosis, and that tapeworms grown in an experimental animal do not take up 3H-thymidine in vitro.

Animals↗
PubMedDate not supplied

[Dermatology topics].

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Antigens, Bacterial↗