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E Heinen

Publications and source records attributed to E Heinen.

At least 91 records · Page 5Linked to original sources
PubMed1984

Isolation of follicular dendritic cells from human tonsils and adenoids. I. Procedure and morphological characterization.

Follicular dendritic cells have been isolated from human tonsils and adenoids and characterized at the ultrastructural level. Follicles were dissected and digested with different hydrolytic enzymes. The cells were separated by sedimentation at unit gravity. By this procedure we obtained follicular dendritic cells enveloping lymphocytes with their cytoplasmic extensions in a way analogous to that described for isolated thymic nurse cells. The ultrastructural features of isolated follicular dendritic cells are similar to those observed in situ. Prolonged enzymatic action caused loss of the enveloped lymphocytes.

Adenoids↗
PubMed1984

Isolation of follicular dendritic cells from human tonsils and adenoids. II. Immunocytochemical characterization.

Follicular dendritic cells (FDC) are specialized cells found only within lymphoid follicles. They bind immune complexes and play a role in the presentation of antigen to follicular B cells and in the generation of B cell memory. In the present report the isolation of FDC from human tonsils and adenoids is described. These isolated cells have an unusual spherical arrangement and enclose lymphocytes within extensions of their membranes. Their ultrastructural features are similar to those observed in situ. The reactivity of isolated FDC with a number of monoclonal antibodies was analyzed by immunofluorescence and by immunostaining (at the electron microscopic level) with colloidal gold. In keeping with the results of previous investigations on tissue sections IgM, IgG and IgA (but not IgD) can be detected on the surface of isolated FDC, as can C3b receptors and the FDC-associated antigen detected by monoclonal antibody R4/23. The immunoglobulins associated with FDC are mostly embedded in an electron-dense material. The majority of the lymphoid cells enclosed within the membrane extensions of FDC are of B cell type. These results suggest that isolated FDC may be suitable for further in vitro investigation of their role in the humoral immune response.

Adenoids↗
PubMed1984

Precise localization of antigens on follicular dendritic cells.

Horse-spleen ferritin or bovine serum albumin conjugated to colloidal gold (BSA-gold) were injected subcutaneously in preimmunized mice. In draining lymph nodes both antigens were located in macrophages or between the cytoplasmic processes of follicular dendritic cells (FDC). Some of the antigens remained trapped on FDC until day 31 after injection. Simultaneous injection of both antigens showed that they were located between the infoldings of the same FDC. These cells are thus able to retain at least two different antigens on their surface. The peculiar arrangement of ferritin between the cytoplasmic infoldings suggests that this antigen is fixed on both cell membranes by specific antibodies. The trapped immune complexes could thus stabilize the FDC membrane system. The antigen retention requires the presence of specific antibodies since BSA-gold or ferritin injected without preimmunization were not found between FDC processes. Nonantigenic materials, such as colloidal gold or carbon particles, are not trapped by FDC, except when injected in large amounts. The antigens were trapped on the surface of FDC, however unfrequently in close contact with lymphocytes. FDC might protect lymphocytes against an excess of immune complexes and act as regulators of contacts between lymphocytes and immune complexes.

Animals↗
PubMed1984

Functional study of human tonsillar follicular dendritic cells.

Follicular dendritic cells (FDC) isolated from human tonsils and adenoids appear as round clusters where the FDC surround lymphoid cells. Using fluorescein and colloidal gold labelled antibodies we determined their surface antigens, the immunoglobulins they fix and the cells they envelope. Isolated FDC react with specific anti-FDC antibodies but also with an anti-monocyte/macrophage antibody and with anti-HLA-DR antibodies. They retain IgG, IgM, IgA and IgE but not IgD immunoglobulins; this retention occurs, according to our results, via their Fc and C3b receptors. The cells they envelope are mainly B cells, but also occasionally T helper cells. T suppressor cells were only rarely found in contact with FDC. We suggest that FDC create a micro-environment favourable to the proliferation and differentiation of B cells during the humoral response.

Adenoids↗
PubMed1984

[Calculated and measured oxygen saturation. A valid comparison of the Kelman, Severinghaus, and Siggaard-Anderson formulas for calculating oxygen saturation of patients in intensive care].

The validity of calculation of oxygen saturation by means of Kelman's, Severinghaus ' and Siggaard -Andersen's formulas was investigated in 329 arterial and 26 mixed venous blood samples of intensive-care patients. The spectrophotometric measurement of oxygen saturation with Radiometer's Hemoximeter OSM2 served as reference. In spite of good coefficients of correlation regarding the total number of samples (r 0,963/ Kelman's formula; r = 0,964/ Severinghaus and Siggaard -Andersen's formula) there were not as satisfactory correlations in some individual patients. The study shows that there was a decrease in conformity between measured and calculated oxygen saturation with decreasing oxygen tension in the blood. Sufficient accuracy of calculation of saturation can be expected only with pO2 greater than 80 mmHg. Siggaard -Andersen's formula was slightly superior to the other tested algorithms.

Adult↗
PubMed1983

Colloidal gold, a useful marker for antigen localization on follicular dendritic cells.

Bovine serum albumin (BSA) bound to colloid gold particles (BSA-gold; 20 nm diameter) and injected into preimmunized mice was found at ultrastructural level in different locations of the lymph nodes. It was detected particularly in the secondary lysosomes of macrophages and between the cytoplasmic processes of the follicular dendritic cells. Between these processes the gold particles were isolated or grouped in clusters; they were in close contact with cell membranes or embedded in dense material. Colloidal gold injected alone was not retained on these cells. The presence of anti-BSA antibodies in the serum was necessary for trapping of BSA-gold particles on follicular dendritic cells. Injections of BSA alone after BSA-gold had been administered to preimmunized mice eliminated most of the BSA-gold from the dendritic processes. BSA-gold is thus trapped in the form of immune complexes which behave characteristically. BSA-gold is thus a suitable marker for antigen localization. Being small and electron dense it permits more precise location than radioactive markers.

Animals↗
PubMed1982

Follicular dendritic cells in lymph nodes after x-irradiation.

Follicular dendritic cells (FDC), non lymphoid cells present in lymph follicles, are characterized by numerous cytoplasmic processes retaining antigen-antibody complexes. Their origin, nature and function are unknown. Mice inguinal lymph nodes after 4.5 or 7.5 Gy X-irradiation were depleted of lymphoid cells. Ultrastructural observations during the first few days post-irradiation show that FDC are unaltered and possess dendritic processes enveloping dense material. Furthermore, they show intense metabolic activity. A lamina densa, never observed so well-developed in other lymph node cells, was detected around the nuclear envelope. The localization of junctions between FDC was analysed. FDC preserve their typical cytoplasmic processes even if lymphoid cells are rare. The latter thus seem not to be responsible for the maintenance of FDC integrity or their development. The possible role of this for antibody production is discussed. Irradiated lymph nodes of lymphoid cells are highly convenient for studying FDC. Isolation of FDC from irradiated lymph organs would seem to be possible.

Animals↗
PubMed1982

[Relation between immunogenicity and differentiation of metastasis in an experimental murine melanoma].

The graft into the footpad of Jackson mice of B16 melanoma cells which are only slightly pigmented, induces the simultaneous appearance of achromatic and well-pigmented metastatics. We have analysed histologically both types of metastases from the 8th to the 20th day after the resection of the primary tumor. The percentages of mitoses are higher in the achromatic metastases than in the pigmented ones. Both are infiltrated by lymphocytes and by a small number of macrophages and polymorphonuclears. A statistical analysis demonstrates however that the percentage of lymphocytes is not related to the importance of the metastase pigmentation. The discussion is devoted to the relations between the infiltration by lymphocytes, the immunogenicity and the differentiation of the tumor.

Animals↗
PubMed1982

[Effects of cis-dichlorodiaminoplatinum II (cis-Pt II) on chromatin ultrastructure in animal or plant cells and repercussions on the cell cycle].

Cultivated animal cells (mouse peritoneal macrophages, chick fibroblasts or mouse Ehrlich tumor cells) or Zea mays root tips are treated with cis-Pt (II). Various effects (chromatin dispersion or condensation, pycnosis) are observed under some experimental conditions in all cell types. Cytoplasmic ribosomes in helical aggregates appear but only in vegetal cells. Mitosis and cell cycle disturbances due to cis-Pt (II) are probably related to chromatin alterations. We suggest that the latter and helical polyribosomes are produced by cis-Pt (II) reaction with nucleic acids in these structures.

Animals↗
PubMed1982

[Clinical significance of free serum thyroxine--comparative studies with 5 methods].

In order to check whether the serum free T4 as obtained with commercially available kits can substitute for total T4 measurements in the routine diagnosis of thyroid disorders, serum FT4 was simultaneously assayed using 5 different methods (Amerlex; GammaCoat; Immo-Phase; LiquiSol; T4/TBG) in 152 subjects. Overt hyper- and hypothyroidism were readily distinguished from euthyroidism with each method. Discrepant FT4 results, however, were obtained with these assays in clinically euthyroid subjects exhibiting various extrathyroidal disorders (TBG-deficiency or -excess, late pregnancy, serious illness, T4 administration). Since it is as yet impossible to decide which of the commercial kits will yield methodologically and physiologically reliable results, a substitution of total T4 measurements by FT4 cannot yet be recommended in the laboratory diagnosis of thyroid disease.

Female↗
PubMed1982

[Binding of cationized ferritin to the surface of the palatine crest in the rat].

Recently, we suggested that the cell coat of the surface epithelial cells of the palatal shelves and especially its sialyl groups are implied in the adhesion process which initiates the constitution of the secondary palate. In this work, use of cationized ferritin which interacts with anionic receptors of the plasma membrane give us the possibility to render these sialic acids visible. After five minutes incubation in presence of cationized ferritin, the labeling particles are distributed in monolayer over the plasmalemma of epithelial cells. Subsequent incubation in cationized ferritin free medium results in clustering of the marker followed by the detachment of the labeled patches. Otherwise, incubation in the presence of neuraminidase from Clostridium perfringens before the polycationic ligand contact prevents labeling. We think that lateral migration modifications of the anionic receptor could be associated with changes of the shelves capacity to adhere.

Animals↗
PubMed1981

Thyroid function and thyroid hormone metabolism in elderly people. Low T3-syndrome in old age?

T4-, T3- and reverse-T3 concentrations were measured in the sera of 365 subjects beyond the age of 65 in order to evaluate if the decrease of serum T3 frequently observed in old age can be attributed to old age per se or to concomitant nonthyroidal disease. The results obtained from a carefully selected healthy group of elderly people show that 1) total and free T3 levels are lower in senescence but well within the range for euthyroidism in younger healty controls;2) the decrease of serum T3 is more pronounced and occurs earlier in healthy old males than in females, so that for subjects over the age of 75, the upper limit for euthyroidism has to be adjusted by 10% in women and by 20% in men; and 3) there is no low T3 syndrome characterized by decreased serum T3 and increased serum reverse T3, solely due to old age. Turnover kinetics have shown the daily production of T4 and T3 in old age to decrease by 20 micrograms and 10 micrograms, respectively, and an increased T3 metabolic clearance not to account for the reduction of serum T3 concentrations. Combined stimulation tests with TSH and TRH showed that the functional reserve of the thyroid gland to produce T3 is maintained in old age. The first step in the sequence of events may be seen in an impairment of TSH secretion leading to an adaptation of the amount of thyroid hormones to a reduced mass of metabolically active body tissue in old age.

Aged↗
PubMed1981

Secondary hypothyroidism in severe non thyroidal illness?

In severely ill patients of an intensive care unit overt peripheral thyroid hormone deficiency was noted in 22 of 33 subjects. The TRH-test was performed in 7 of these 22 patients and was negative in all. Thus, the laboratory data suggest secondary hypothyroidism. The laboratory diagnosis, however, could not be supported by clinical signs probably due to the short period of observation and to the strongly elevated body temperature of the respective patients. The pathogenetic mechanism is not clear. However, all patients developing secondary hypothyroidism were treated with dopamine and/or glucocorticoids, compounds known to inhibit pituitary TSH release and most of the patients had septic fever. A persistently "hypothyroid state" (total T4: 23 +/- 15 nmol/l, free T4: 6.1 +/- 3.2 pmol/l, total T3: 0.28 +/- 0.22 nmol/l, S.D.) is associated with a very poor prognosis. In view of the negative effects of a hypothyroid state, substitution of thyroid hormones must be considered in this situation.

Body Temperature↗
PubMed1981

Hepatic microsomal ethanol-oxidizing system (MEOS): increased activity following propylthiouracil administration.

Treatment for 7 days with the thyreostatic drug propylthiouracil (5 mg/100 g of body weight) resulted in a hypothyroid hepatic state as shown by the marked decreased hepatic content of thyroxine and triiodothyronine. This regimen led to an enchanced activity of the microsomal ethanol-oxidizing system, whereas the activities of alcohol dehydrogenase and catalase remained unchanged. Moreover, a hyperthyroid hepatic state achieved following the daily administration of L-thyroxine (150 micrograms/100 g of body weight) or L-3,3', 5-triiodothyronine (10 micrograms/100 g body weight) for 7 days resulted in a similar increased activity of the microsomal ethanol-oxidizing system. Under these conditions, a decrease of alcohol dehydrogenase activity and an unaffected catalase activity was observed. These findings, therefore, show that the administration of either propylthiouracil or thyroid hormones results in an increased activity of the microsomal ethanol-oxidizing system, suggesting that the underlying mechanism for the induction of the microsomal ethanol-oxidizing system by propylthiouracil is independent of the action of thyroid hormones.

Alcohol Oxidoreductases↗
PubMed1981

Nifurzide, a nitrofuran antiinfectious agent: interaction with Escherichia coli cells.

This paper presents a study of the interactions between Escherichia coli cells and nifurzide, a nitrofuran derivative which is used as an intestinal antiinfectious agent. At low concentrations of nifurzide, the growth rate of the cultures decreased, and elongated, nonseptate cells appeared. At high concentrations, complete growth inhibition occurred, accompanied by a rather strong bactericidal effect, but the appearance of the cells was normal; in particular, no bacteriolytic effect was observed. A very large number of antibiotic molecules were bound per bacterial cell. After cell disruption, similar amounts of nifurzide were found in the cytoplasm, cytoplasmic membranes, and cell wall, respectively. Most of the bound nifurzide was rapidly degraded or became protein bound. The structure of the outer membrane lipopolysaccharide appeared to have little influence on the activity of nifurzide.

Anti-Bacterial Agents↗
PubMed1981

[Ultrastructural study of the effects of neuraminidase on the palatine process of the rat].

In a previous work, we demonstrated that palatine processes treated with 10 micrograms/ml neuraminidase for 30 minutes at 37 degrees C show a delayed fusion in vitro. In order to investigate the effects of neuraminidase, the treated palatine processes were observed with the aid of transmission and scanning electron microscopy. The effect of neuraminidase is exclusively detectable on superficial flat cells of the palatine processes, especially the cells of the medial edge of the process. The epithelial basal cells remain unchanged. Observed with the S.E.M., the superficial epithelial cells show bubbles, become spherical and detached. To explain these observations, we namely propose the following hypothesis: the action of neuraminidase prevents the fusion of the palatine processes because it denudes basal cells bearing a too immature cell coat for ensuring sufficient adherence between the palatine processes.

Animals↗