Experimental gingivitis during pregnancy and post-partum: immunohistochemical aspects.

The histoimmunological response of 8 individuals was studied longitudinally in relation to the development of experimental gingivitis during pregnancy and post-partum. At day 0 as well as at day 14 of experimental gingivitis the mean periodontal pocket bleeding index (PPBI) was higher during pregnancy than post-partum, whereas the amount of plaque that accumulated was similar. The number of CD1 positive cells (mainly Langerhans) in the oral epithelium was found to be higher during pregnancy.

Effects of cadmium exposure during pregnancy on cadmium and zinc concentrations in neonatal liver and consequences for the offspring.

The effects of cadmium exposure during pregnancy (by means of daily subcutaneous injections of 4.4 mumol/kg to the mother) on the neonates were investigated. No effect was observed on fetal or neonatal body weights, nor on neonatal liver weights.

Lymphocyte depletion in thymic nurse cells: a tool to identify in situ lympho-epithelial complexes having thymic nurse cell characteristics.

In situ pre-existing complexes of epithelial cells and thymocytes having thymic nurse cell characteristics were visualized in the murine thymus cortex using dexamethasone as a potent killer of cortisone-sensitive thymocytes. The degradation and subsequent depletion of cortisone-sensitive thymocytes enclosed within cortical epithelial cells appeared to be paralleled by thymocyte degradation and depletion in thymic nurse cells isolated from thymic tissue fragments from dexamethasone-treated animals. This suggests that thymic nurse cells are derived from pre-existing sealed complexes of cortical epithelial cells and thymocytes.

Differences in immunological susceptibility to cadmium toxicity between two rat strains as demonstrated with cell biological methods. Effect of cadmium on DNA synthesis of thymus lymphocytes.

When 2 inbred rat strains, the Brown-Norway rat and the Lewis rat were exposed to the same amount of CdCl2 for 15 days, a completely different immunological reaction pattern could be demonstrated. Despite the same amount of intrathymic cadmium in both strains, the Brown-Norway rat showed a significant decrease in thymocytes in the S-phase and a significant increase of thymocytes in the G2 phase and mitosis, in contrast with findings in the Lewis rats. A new method for estimating subtle forms of thymus atrophy showed a slight decrease in the number of the smallest thymocytes in the Brown-Norway rat after exposure to cadmium, in contrast with that in the Lewis rat.

The effects of long-term exposure to cadmium on the small blood vessels in the rat uterus: a light microscopic study.

A group of female Wistar rats was exposed to 0.5 mg/kg cadmium three times a week for a period of 29 weeks. The cadmium was administered as the chloride in saline by subcutaneous injection.

Effects of chronic cadmium administration on placental and fetal development.

Cadmium was administered subcutaneously to pregnant Wistar rats: 0.49 mg/kg as CdCl2 in saline daily, starting at the day of conception. Placentas and fetal livers were collected on day 14, 16, 18, 19 and 20 of gestation.

T cell differentiation within thymic nurse cells.

Thymic nurse cells (TNC), defined as in vitro isolation products of thymic tissue, are epithelial cells harboring in their cytoplasm up to 200 intact, actively dividing thymocytes which are completely surrounded by vacuolar membranes. The TNC plasma membrane expresses major histocompatibility complex class I (H-2 K/D) and class II (I-A) antigens. The expression of MHC class I and class II antigens on the TNC vacuolar membranes was investigated with an improved in situ labeling technique.

Differential requirements for rabbit dendritic cells and macrophages in T lymphocyte proliferation induced by various mitogens.

Dendritic cells have been isolated from rabbit lymph nodes. Morphologically and phenotypically, they resemble dendritic cells from the mouse and rat. A comparison was made of the accessory cell function of dendritic cells and peritoneal macrophages in T-cell proliferation induced by phytohaemagglutinin (PHA) or Con A, or by a simultaneous treatment with the enzymes neuraminidase and galactose oxidase (NaGo).

T-cell differentiation in the rabbit. II. Con A and PHA response of thymus, spleen and lymph node cells and of thymus subpopulations; influence of dexamethasone treatment.

Mitogen-induced proliferation of rabbit lymphocytes from the thymus (Thy), spleen (Spl) and lymph node (LN) was measured by [3H]thymidine incorporation. The various cell suspensions taken from normal animals showed wide differences in their response to Con A and PHA. Cell suspensions taken from steroid-treated animals did not show differences in response.

T-cell differentiation in the rabbit. I. Cytofluorometric analysis of a T-cell antigen on lymphocytes from normal and dexamethasone-treated animals.

The specificity of a rat anti-rabbit thymocyte antiserum (ATS), as analysed with immunofluorescence techniques, is described. The antiserum was used in cytofluorometric studies to quantify the density of the corresponding T-cell antigen present on the various lymphocyte populations. On the basis of fluorescence intensity, the positive cells could be divided into four classes.

Observations on transmembrane structures of surface immunoglobulin in the plasma membrane of B lymphocytes.

We have investigated the possible role of intramembraneous particles as revealed by freeze-fracture electron microscopy in the plasma membrane of B lymphocytes from rabbits and mice as reflections of transmembrane structures of surface immunoglobulin receptor molecules. This was achieved by aggregation of the surface receptors using fluorochrome-conjugated antibodies, fixation and freezing of the cells in 35% glycerol. This procedure resulted in replicas of lymphocytes with well-preserved morphology (no ice-crystals), enabling the study of both protoplasmic and external fracture face in combination with surface receptor markers.

The use of tannic acid fixation for the electron microscope visualization of fluorochrome-labelled antibodies attached to cell surface antigens.

Tannic acid as a prefixative for EM purposes was introduced by Futaesaku et al. (1972). The fixative creates conditions for enhancing electron density of different protein materials.

The immotile cilia syndrome: phase contrast light microscopy, scanning and transmission electron microscopy.

In the immotile cilia syndrome, transmission electron microscopy of the cilia shows abnormalities in the arrangement of the central pairs of tubules and in the dynein arms of the peripheral tubules, or in the radial spokes, We studied four nonrelated children, 9/12, 5, 6, and 6 years old, with situs inversus and a history of chronic sinusitis and bronchitis (Kartagener's syndrome) and four children in the same age group and with the same history, but without situs inversus. Under the phase contrast microscope no motile cilia were seen in the four patients with Kartagener's syndrome and in two of the four other children. Transmission electron microscopy showed aberrations in the cilia (absence of dyneim arms, random orientation of central tubules) in the patients with Kartagener's syndrome.

Cytophotometric, flow cytofluorometric and morphometric demonstration of the existence of an antigen dependent thymus lymphocyte subpopulation.

Using absorption cytophotometry and flow cytofluorometrical DNA and protein estimation of single thymus lymphocytes we were able to establish that after injection of a large dose of antigen (ovalbumin) a subpopulation of lymphocytes arises in the thymus with high protein contents above that of those lymphocytes normally present, however, in small quantities in the thymus. By morphometrical analysis it was established that these lymphocytes are situated in the outermost cortex.

Ultrastructural studies of peripheral blood lymphocytes in T cell-depleted rabbits. A scanning and transmission electron microscopic analysis.

Density separation of purified peripheral blood leucocytes from T-cell depleted rabbits on a linear Ficoll-metrizoate gradient has been applied to obtain different leucocyte fractions. Two lymphocyte fractions separated on density seem to have different characteristics, both morphologically and immunologically. In this study these two fractions have been characterized ultrastructurally by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and a relationship has been established between the surface architecture (SEM), the cell size (SEM/TEM) and surface-Ig/C3-receptors (LM, light microscopy).

A cytophotometric and flow cytofluorometric approach to the differentiation of T lymphocytes in the thymus.

By cytophotometric and flow cytofluorometric DNA and protein determinations two main proliferating subpopulations of thymus lymphocytes with a different percentage of cells in the S phase could be distinguished. One subpopulation had a very low protein content, was cortisone sensitive and located in the cortex. Cells with comparable low protein contents were not found amongst lymphocytes of the peripheral blood.

[Heavy chain disease: humoral and cellular findings in six patients with mu chain disease (author's transl)].

Clinical and chemical findings in 6 patients with mu-chain disease are reported. In all of these patients a lymphoproliferative disease was observed which by its symptoms resembled CLL. This similarity was underlined by the finding of an impaired response of PBL of the patients to mitogens as PHA, PWM, and Con A.