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Biomedical subjects

B Heymer

Publications and source records attributed to B Heymer.

At least 91 records · Page 5Linked to original sources
PubMed1978

The cervical lymph nodes in Streptococcus pyogenes, group A, type 50, infection in mice.

Streptococcus pyogenes, group A, type 50, one of the few group A streptococcal types naturally occuring in mice, proved highly virulent in this species after experimental infection. Intranasal infection of 96 mice (Swiss albino, NMRI, and CBA) with this microorganism induced profound reactions in the cervical lymph nodes of 69% of the animals. Histologically, two different forms of reaction were distinguishable. In 61 mice, the lymph nodes exhibited follicular and lymphoplasmacellular hyperplasia and in 9 animals suppurative lymphadenitis was present. The ability of type 50 streptococci to persist in the pharynx of mice, and the similarity of the morphological changes induced by this organism appear to make intranasal murine group A, type 50, streptococcal infection a suitable model for human streptococcal pharyngitis.

Animals↗
PubMed1978

Immunomorphology and pathogenesis of echinococcosis. III: Microscopic immunofluorescence studies in experimental alveolar echinococcosis.

By application of immunohistological methods in experimental alveolar echinococcosis, detailed information was obtained on the antigenic properties of each component of the echinococcus cyst. It was established that of the various layers, the capsula germinativa of the parasite cyst possesses the strongest antigenicity regardless of localization and maturity of the cysts. The dissemination of echinococcal antigens within the internal organs of the experimental animals was found to follow the general trends of other infections. Substances obtained from the capsula germinativa appear most suitable as reagents for immunodiagnostic purposes due to their strong antigenicity.

Animals↗
PubMed1978

Reversion of dextran sulfate-induced loss of antibacterial resistance by Bordetella pertussis.

Parenteral injection of dextran sulfate 500 (DS 500; 50 mg/kg of body weight) into mice caused a complete loss of resistance to a sublethal (2 X 10(3) to 5 X 10(3)) infection with Listeria monocytogenes. Such loss could be prevented by pretreatment of animals with 3 X 10(9) heat-killed Bordetella pertussis organisms (PO) 5 to 30 days before the administration of DS 500. The increased phagocytic capcity induced by PO was only exhausted when a fourfold dose of DS 500, effecting complete loss of antibacterial resistance (50 mg/kg ob body weight), was administered. Listeriosis in mice treated with DS 500 is characterized by rapid-progressive necro-purulent inflammation of liver and spleen, lack of mononuclear phagocyte response, and 100% lethality within 72 h after infection. In contrast, the time course, extent, and morphological characteristics of listeriosis in animals pretreated with PO before the DS 500 application were not significantly different from those of nonpretreated controls. Evidence is presented that the protective effect of PO is due to activation of the mononuclear phagocyte system, which without such treatment is blocked by the DS 500 administration. The data presented indicate that the protective effect of PO is due only in part to the endotoxic moiety of these bacteria. Differences in the course and morphology of listeriosis in animals with dysfunction of the mononuclear phagocyte system and in animals with deficiency of the cellular immune system are discussed.

Adjuvants, Immunologic↗
PubMed1978

Absence of binding of MDP, a synthetic immunoadjuvant, to anti-peptidoglycan antibodies.

The binding of the synthetic immunoadjuvant N-acetyl-muramyl-L-alanyl-D-isoglutamine (MDP, for muramyl dipeptide) to human and rabbit sera containing peptidoglycan (PG) antibodies was investigated. Studies were performed by employing the corresponding 14C or 125I-labeled compounds in Farr-type binding and inhibition assays. Whereas MDP did not react with naturally occurring or experimentally induced PG-antibodies, the analog of MDP MDP-L-Lys-D-Ala did bind to hyperimmune rabbit anti-PG sera, but not to the human sera tested. These studies indicate that the radioimmunoassays employed basically are applicable for the selection of nonimmumogenic MDP analogs possessing immunoadjuvant activity.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1978

Immunoadjuvant effects of the synthetic muramyl-dipeptide (MDP) N-acetylmuramyl-L-alanyl-D-isoglutamine.

The adjuvant activity of the synthetic muramyl-dipeptide (MDP) N-acetyl-muramyl-L-alanyl-D-isoglutamine upon immunization of mice with BSA or SRBC was studied. MDP was found to significantly increase BSA-antibody formation and to favour the induction of anaphylactic reactions to BSA. In contrast, under the conditions employed, MDP only weakly stimulated the immune response to SRBC.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1977

Pathomorphology of humoral, cellular and combined primary immunodeficiencies.

Histologic, immunohistologic and electron microscopic findings in three children with primary immunodeficiencies are reported. Classical X-linked infantile agammaglobulinemia Bruton was present in case 1 (male, aged 16 years), selective cellular immunodeficiency with thrombopenia in case 2 (male, aged 2 1/2 years) and non-lymphopenic severe combined immunodeficiency in case 3 (male, aged 1 3/4 years). At autopsy, all three cases exhibited unusual types of pneumonia. In case 2 a generalized cytomegalovirus infection was present. Case 3 disclosed panmyelopathia and chronic liver lesions due to severe GvH-reaction subsequent to bone marrow transplantation. A detailed morphologic study of the immune system revealed distinct alterations in the thymus, spleen, and lymph nodes and the lymphatic tissues of the gastrointestinal tract characteristic of an immunodeficiency state, either humoral (case 1), cellular (case 2) or combined (case 3).

Adolescent↗
PubMed1977

Role of Candida albicans in granulomatous tissue reactions. I. In vitro degradation of C. albicans and immunospecificity of split products.

Several mannan-containing fractions were obtained from whole cells, cell walls, and cytoplasm of Candida albicans by means of treatment with hot formamide or precipitation with (NH4)2SO4. The immunological and chemical characteristics of the fractions were compared with those of C. albicans mannan prepared by standard procedures. Antisera to C. albicans from rabbits immunized with whole cells of the organism were found to be primarily directed against the mannan content. With use of such antisera, mannan was localized in both the inner and outer layers of the cell wall, whereas the middle layer was found in all likelihood to represent the glucan polymer. Stepwise removal of mannan from whole cells or cell walls resulted in increasing loss of periodic acid-Schiff staining, immunofluorescence, and peroxidase reactivity. Thus, it appears that mannan is responsible for the ability of cell walls of C. albicans to be stained by periodic acid-Schiff or labeled with fluorescent antibody. The component of the pathogen most resistant to physical or chemical treatment was the glucan, which lacked all immunological reactivity.

Antigens, Fungal↗
PubMed1977

Role of Candida albicans in granulomatous tissue reactions. II. In vivo degradation of C. albicans in hepatic macrophages of mice.

Hepatic granulomas were induced in mice by injection of blastospores, cell walls, and glucan of Candida albicans. Granulomatous reactions in liver tissue initially multiplied but later decreased. A dose-response relationship was apparent with up to 3 mg of inoculum. Shortly after injection of C. albicans spores, fungal elements appeared in liver macrophages and were detectable in granuloma and Kupffer cells for 20 days. Gram-stain, periodic acid-Schiff (PAS), and immunofluorescence reactions soon vanished, and the organisms could no longer be seen. Glucan of C. albicans, which lacked PAS and immunofluorescence reactivity, proved active in initiation of granulomas. Degradation of phagocytized spores of C. albicans, reductions of cytoplasm, and cell wall deformation and collapse support the premise that loss of PAS and immunofluorescence reactivity was caused by enzymatic breakdown of candida cell wall mannan in macrophages. We conclude that C. albicans can induce granulomatous reactions in mouse liver when the glucan that forms the cell wall matrix in Candida persists in identifiable residues.

Animals↗
PubMed1977

Antibody-forming potential of lymph nodes in aged mice, with special reference to the influence of adjuvant.

The secondary antibody-forming potential of non-splenic lymphatic tissues during senescence was investigated in NMRI/Han mice, both at the cellular and humoral levels. The mean life span of conventionally reared NMRI/Han mice amounts to 19.86 months. After primary immunization of aged (20-month-old) NMRI mice with 4 X 10(8) sheep erythrocytes (SE) by the intraperitoneal (i.p.) route, the primary antibody-forming potential of both spleen and lymph nodes was significantly reduced, as compared to young adult (3-month-old) controls. In contrast, the anamnestic response elicited by an i.p. booster injection of 4 X 10(8) SE at the 44th day after primary immunization was not significantly diminished in comparison to the controls. When killed cells of Bordetella pertussis were found to be significantly increased in young adult as well as in aged mice. These data obtained at the cellular level were in accordance with corresponding serological findings. The impressive restitution of the antibody-forming potential evident after secondary antigenic stimulation was associated with a remarkable restitution of the lymph node morphology. This was particularly pronounced in the pronounced in the parathymic lymph nodes which represent the draining nodes for the peritoneal cavity. These findings indicate that the lymph nodes of the senescent individual also possess remarkable reserves in immunocompetence.

Adjuvants, Immunologic↗
PubMed1976

Pathomorphologic findings in severe combined immunodeficiency and reticular dysgenesia.

Pathomorphologic findings in an 11 month old boy with severe combined immunodeficiency (case 1) and in a 4-month old boy with reticular dysgenesia (case 2) are reported. Case 1: The bone marrow exhibited regular granulo-, erythro- and thrombopoiesis. The hypoplastic thymus consisted exclusively of epithelial reticulum cells. The spleen and lymph nodes showed considerable depletion of lymphocytes in both the T- and B-cell areas. There was a complete lack of all lymphatic structures in the gastrointestinal tract and aplasia of the tonsils. Death resulted from Candida sepsis in conjunction with giant cell pneumonia closely resembling Hecht's pneumonia in measles. Case 2: The bone marrow showed a total lack of granulopoiesis. The storngly dysplastic thymus weighed only 1 g. The spleen, the lymph nodes and the gastrointestinal tract exhibited a very strange histologic structure resulting from a complete absence of lymphocytes and plasma cells. The tonsils were aplastic, the para-thyroid glands as well as the other endocrine glands were normally developed. The cause of death was Klebsiella sepsis and Pneumocystis pneumonia, the latter without the characteristic interstitial plasma cell infiltration. The importance of the immune system for activation of the nonspecific mechanisma of defense is discussed with respect to the two types of immunodeficiency states described here.

Agranulocytosis↗
PubMed1976

[Atypical aortic coarctation (author's transl)].

Special problems in the surgical treatment of aortic coarctation may be caused by unusual morphological findings as a long hypoplastic segment, the combination with pre- or poststenotic aneurysms or by atypical localisation of the stenosis in the aortic arch, the decreasing or abdominal aorta. A bypass procedure is considered as the method of choice for the repair of coarctation in the aortic arch or the "critical zone" of the abdominal aorta (renal- and suprarenal segment). The bypass-principle allows many variations of branching and avoids cross-clamping of the aorta. The involvement of important branches as is the left common carotid, the superior mesenteric or the renal artery, necessitates a vascular reconstruction in the same session. Probably the first report about a very rare combined lesions is presented: the combination of an aortic arch coarctation in association with a complete situs inversus (right descending aorta), a common carotid trunc, an aneurysm of the left subclavian artery (first branch of the arch) and congenital cysts of the right upper lobe of the lung (Case No. 1). Usually concomitant aneurysms are found in the pre- or poststenotic aortic segment. Some of the infrarenal fusiform aneurysms (Case No. 4 and 5) are occasionally of poststenotic origin, secondary to a longstanding infrarenal coarctation. In these cases the procedure of choice is the total exstirpation and the interposition of a Dacrongraft. Important branches (as the subclavian or renal artery) can be some times inserted directly in the vascular protheses. Using the bypass technic or the patch graftplastic of Vosschulte the risk of late operation (beyond the age of 30 years) may be remarkably reduced.

Adolescent↗
PubMed1976

Morphology and time course of experimental listeriosis in nude mice.

Experimental listeriosis in phenotypically normal (nu/+) euthymic NMRI mice has a characteristic morphology and short-term course. In contrast, listeric infection in congenitally dysthymic nude (nu/nu) mice does not proceed in clear-cut phases, develops more slowly, displays a chronic tendency from the beginning, and shows a considerably different morphology. The inability of nude mice to effectively control and terminate infection by Listeria monocytogenes obviously results from the lack of T lymphocytes.

Animals↗