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Biomedical subjects

H Lemke

Publications and source records attributed to H Lemke.

67 records · Page 4Linked to original sources
PubMed1975

Macrophages suppress direct B-cell activation by lipopolysaccharide.

The influence of macrophages on polyclonal B-cell responses to lipopolysaccharide (LPS) and on a primary, specific immune response to a hapten-LPS conjugate was studied in mouse spleen and lymph node cells in serum-free and serum-supplemented cultures. Macrophages were found not to be necessary, and B cells were directly activated by LPS. In serum-free cultures of macrophage-depleted spleen cells, (a) proliferation and antibody secretion occurred at normal levels or were enhanced when compared with normal spleen cells, (b) the responsiveness of limiting cell numbers to LPS was better than in normal spleen cell cultures, (c) LPS did not increase the number or activate residual macrophages, (d) the primary specific response to a hapten-LPS conjugate developed normally, (e) peripheral lymph node cells, which are known to contain a very low concentration of macrophages, from normal or congenitally athymic (nude) mice mounted excellent proliferative responses to LPS. Furthermore, in cultures supplemented with fetal bovine serum, depletion of adherent cells resulted in enhancement of LPS-induced B-cell responses. Addition of peritoneal macrophages to adherent cell-depleted spleen cells produced suppression at all concentrations of both mitogen and adherent cells. Suppressive activity could also be demonstrated in supernatants from adherent cell cultures stimulated by LPS.

Animals↗
PubMed1974

[Pharmacologic-endocrinological findings in animal experiments with TURISYNCHRON and SUISYNCHROM. 2. Toxicologic findings].

Acute, subacute and chronic toxicity of TURISYNCHRON and its zinc complex (SUISYNCHRON) was tested in mice, rats and dogs. The acute toxicity of SUISYNCHRON was lower than that of TURISYNCHRON in mice and rats. Ulcerative lesions in the duodenum produced by high doses of SUISYNCHRON were quantitatively less pronounced than those produced by similar doses of TURISYNCHRON. Subacute toxicity testing in rats showed that neither preparation had any toxic effect on haematological, clinical chemical or histological criteria in the dosages selected. Chronic toxicity testing of TURISYNCHRON in dogs did not reveal any evidence of toxic damage.

Acute Disease↗
PubMed1974

[Pharmacologic-endocrinological findings in animal experiments with TURISYNCHRON and SUISYNCHRON. 3. Selected pharmacologic and immunologic findings].

Comparison of the action of TURISYNCHRON and its zinc complex SUISYNCHRON in mice, rats and dogs showed that neither compound interfered with the implantation process in rats. After oral administration, blood concentrations were lower with SUISYNCHRON than with TURISYNCHRON. The zinc complex was broken down in the acid medium of the stomach, and absorbed in the duodinum or in distal segments of the intestine. Metallibure did not affect on phagocytosis not the course of infections with Escherichia coli or Erysipelothrix insidosa. Both compounds had a thymolytic action, which did not mimic the effect of cofticosteriods.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Evidence for the detection of the normal counterpart of Hodgkin and Sternberg-Reed cells.

To clarify the origin of Hodgkin (H) and Sternberg-Reed (SR) cells, frozen sections of lymph nodes from 30 patients with Hodgkin's disease were immunostained with a large panel of monoclonal antibodies reactive with cells of lymphoid tissue and granulopoiesis. The results showed that: (a) H and SR cells are devoid of markers specific to, or characteristic of B cells, macrophages, dendritic reticulum cells, interdigitating cells, or cells of erythropoietic or thrombopoietic origin; (b) the vast majority of H and SR cells contain granulocyte-related antigens detectable with the monoclonal antibodies TU9 and 3C4, but constantly lack other granulocytic cell markers (such as peroxidase and chloroacetate esterase). Monoclonal antibodies raised against a Hodgkin's disease-derived cell line included one, Ki-1, that was found to be selectively reactive with H and SR cells and a minute, but distinct cell population in normal lymphoid tissue and bone marrow. The latter, as yet unidentified cell population appears to be the normal equivalent of H and SR cells.

Animals↗
PubMedDate not supplied

Growth fractions in malignant non-Hodgkin's lymphomas (NHL) as determined in situ with the monoclonal antibody Ki-67.

The proportion of proliferating cells in malignant non-Hodgkin's lymphomas (NHL) was determined in situ by immunostaining with the monoclonal antibody Ki-67, which reacts with a nuclear antigen that is present only in proliferating cells. A highly significant correlation could be demonstrated between the proportion of Ki-67 positive cells and the classification into high and low-grade NHL according to the Kiel classification. 93.8 per cent of high-grade and 88.5 per cent of low-grade malignancies were correctly allocated to these groups using the percentage of Ki-67 positive cells as discriminant parameter. On the basis of the medians, the degree of proliferation also paralleled the succession of entities within the Kiel classification. Within most of these different entities, however, the ranges of Ki-67 positive cells varied considerably, indicating that the growth fractions within these groups are rather heterogeneous. Thus it might be useful to determine the growth fraction of each individual case of NHL, because this might be of prognostic value.

Antibodies, Monoclonal↗
PubMedDate not supplied

Structural processes during starch granule hydration by synchrotron radiation microdiffraction.

Starch granule hydration has been examined on the level of a single potato starch granule by static and dynamic synchrotron radiation (SR) microdiffraction techniques. A cryofrozen, hydrated granule was mapped through a 5 microm SR-beam in order to investigate its internal organization. The edge of the granule showed fiber texture scattering due to radially oriented amylopectin helices. The variation of fiber texture across the granule center supports the model of concentric shells. The crystalline phase appears, however, to increase strongly toward the granule center due to a random amylopectin fraction, which could be related to crystallization of short-range ordered amylopectin during hydration. During gelatinization, the shell structure breaks down and remaining fiber-textured amylopectin domains belong probably to the swollen starch granule envelope. Hydration of a granule was initiated by a microdrop generator and followed in situ by SR-microdiffraction. A fast hydration process with a half time of about 7 s seems to reflect the porous nature of starch granules. The size of the hydrated domains suggests that this process is limited to the level of amylopectin side chain clusters. Longer hydration times are assumed to involve remaining short-range ordered amylopectin and results in larger domains.

Kinetics↗
PubMedDate not supplied

The isolation of thirteen cloned hybrid cell lines secreting mouse strain A derived antibodies with specificity for group A streptococcal carbohydrate.

Thirteen hybrid cell lines originating from the fusion of a BALB/c myeloma with strain A spleen cells were isolated each of which secreted an antibody with specificity for the carbohydrate of group A streptococci. The cell lines were stable over many in vivo passages in (BALB/c X A/J)F1 mice and secreted large amounts of antibodies into the serum and ascitic fluid of their hosts. Seven of the hybrid cell antibodies belonged to the IgM class, five were typed as IgG2a and one as an IgA immunoglobulin.

Animals↗