Taede Sminia

Bio: Taede Sminia is an academic researcher from VU University Amsterdam. The author has contributed to research in topics: Lymnaea stagnalis & Antigen. The author has an hindex of 37, co-authored 118 publications receiving 4329 citations. Previous affiliations of Taede Sminia include University of Amsterdam.

Structure and function of blood and connective tissue cells of the fresh water pulmonate Lymnaea stagnalis studied by electron microscopy and enzyme histochemistry.

Abstract: The morphology and the ultrastructure of the blood and connective tissue cells of Lymnaea stagnalis were studied. Special attention was paid to the role of these cells in the cellular defense mechanism (phagocytosis). This problem was investigated in injection experiments with enzyme histochemistry and electron microscopy.

Structure and function of bronchus-associated lymphoid tissue (BALT).

Abstract: This article deals with the ontogeny, morphology, and function of bronchus-associated lymphoid tissue (BALT). The surface epithelium of the respiratory tract, including the lymphoepithelium of BALT, is described, with emphasis on infiltrated nonepithelial cells (lymphocytes, macrophages). Special attention is given to antigen handling by the lymphoepithelium and the interaction with BALT and lung macrophages. The structure and function of the diverse types of BALT nonlymphoid cells are discussed. The local immune responses (cellular and humoral reactions), the relationships between local and systemic immune reactions, and the role of BALT in the common mucosal immune system are reviewed. The BALT is compared with Peyer's patches in terms of antigen processing, local immune responses, cell populations, and migration of lymphoid and nonlymphoid cells.

Phagocytic activity of macrophages and microglial cells during the course of acute and chronic relapsing experimental autoimmune encephalomyelitis.

Abstract: The ED1 monoclonal antibody recognizes an antigen in lysosomal membranes of phagocytes. The expression of this antigen in cells increases during phagocytic activity. Here we describe the expression of ED1-immunoreactivity during the various stages of both acute (monophasic) and chronic relapsing experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. During the first attack of acute and chronic relapsing EAE, ED1-immunoreactivity was present in macrophages and in cells which displayed morphologic features of activated microglial cells (i.e., cells with thick short processes). At the ultrastructural level these cells were seen to contain phagocytosed myelin structures in lysosomes. ED1-immunoreactivity in these cells was present in the cytoplasm near lysosomes. During the remission phase of acute EAE and the relapse phase of chronic relapsing EAE, ED1-positive cells with dendritic morphology not only were present in or nearby lesions, but were also found at sites distant from lesions throughout large parts of the brain. These cells had a morphology comparable to microglial cells in normal brain. A major difference between animals which were in remission and animals which on day 25 were suffering from a relapse, was that the latter showed the presence of lesions with darkly stained round ED1-positive macrophages and activated microglial cells. These results indicate that during a relapse, newly recruited blood-borne macrophages infiltrate the brain and, together with activated lymphocytes and microglial cells, recommence a new demyelination process.

Determination of the origin and nature of brain macrophages and microglial cells in mouse central nervous system, using non-radioactive in situ hybridization and immunoperoxidase techniques.

Abstract: The origin and nature of brain macrophages and microglial cells in the mouse central nervous system (CNS) were investigated First, the expression and localization of determinants recognized by the different monoclonal antibodies (mAbs) MOMA-1, Mac-1-alpha, and F4/80 (raised against cells of the mononuclear phagocyte system) were immunohistochemically studied in the developing and adult mouse brain In order to clarify the origin of brain macrophages and microglial cells, we used bacteriophage lambda transgenic mice as donors for bone marrow transplantations in recipient mice of different ages During ontogeny, numerous MOMA-1-, Mac-1-alpha-, and F4/80-positive blood monocyte-derived brain macrophages (amoeboid microglia) infiltrated the CNS parenchyma These brain macrophages gradually disappeared from the brain parenchyma at postnatal day 7 (P7) From P17 on, Mac-1-alpha- and F4/80-positive cells were detected within the brain parenchyma with the morphology of resting microglial cells Transitional forms between brain macrophages and "resting" microglia were not observed in the developing brain Combined non-radioactive in situ hybridization and immunohistochemistry revealed many MOMA-1-positive bone marrow-derived brain macrophages that were located in the leptomeninges, the ventricles, and occasionally the blood vessel walls These results show that brain macrophages are of bone marrow origin Many "resting" microglial cells were detected in the brain, mainly in the white matter It appeared that about 10% of these cells displayed the transgenic signal This result indicates that the majority of "resting" microglial cells are of local, presumably neuroectodermal, origin

Monocyte and macrophage heterogeneity

Abstract: Heterogeneity of the macrophage lineage has long been recognized and, in part, is a result of the specialization of tissue macrophages in particular microenvironments. Circulating monocytes give rise to mature macrophages and are also heterogeneous themselves, although the physiological relevance of this is not completely understood. However, as we discuss here, recent studies have shown that monocyte heterogeneity is conserved in humans and mice, allowing dissection of its functional relevance: the different monocyte subsets seem to reflect developmental stages with distinct physiological roles, such as recruitment to inflammatory lesions or entry to normal tissues. These advances in our understanding have implications for the development of therapeutic strategies that are targeted to modify particular subpopulations of monocytes.

Functional food science and gastrointestinal physiology and function

Abstract: The gut is an obvious target for the development of functional foods, acting as it does as the interface between diet and the metabolic events which sustain life. The key processes in digestive physiology which can be regulated by modifying diet are satiety, the rate and extent of macronutrient breakdown and absorption from the small bowel, sterol metabolism, the colonic microflora, fermentation, mucosal function and bowel habit, and the gut immune system. The intestinal microflora is the main focus of many current functional foods. Probiotics are foods which contain live bacteria which are beneficial to health whilst prebiotics, such as certain non-digestible oligosaccharides which selectively stimulate the growth of bifidobacteria in the colon, are already on the market. Their claimed benefits are to alleviate lactose maldigestion, increase resistance to invasion by pathogenic species of bacteria in the gut, stimulate the immune system and possibly protect against cancer. There are very few reports of well-designed human intervention studies with prebiotics as yet. Certain probiotic species have been shown to shorten the duration of rotavirus diarrhoea in children but much more work is needed on the mechanism of immunomodulation and of competitive exclusion and microflora modification. The development of functional foods for the gut is in its infancy and will be successful only if more fundamental research is done on digestive physiology, the gut microflora, immune system and mucosal function.

Oecd guideline for testing of chemicals

Abstract: 1. The in vivo alkaline comet (single cell gel electrophoresis) assay (hereafter called simply the comet assay) is used for the detection of DNA strand breaks in cells or nuclei isolated from multiple tissues of animals, usually rodents, that have been exposed to potentially genotoxic material(s). The comet assay has been reviewed and recommendations have been published by various expert groups (1) (2) (3) (4) (5) (6) (7) (8) (9) (10). This Test Guideline is part of a series of Test Guidelines on genetic toxicology. A document presented as an Introduction to the Test Guidelines on genotoxicity (11) can also be referred to and provides succinct and useful guidance to users of these Test Guidelines.

Modulation of Osteoclast Differentiation

Abstract: I. Introduction BONE is a complex tissue in which resorption and formation continue throughout life. This process is called bone remodeling. Osteotropic hormones such as 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], PTH, and calcitonin preferentially modulate the process of bone resorption to maintain bone remodeling. The bone tissue contains various types of cells, of which the bone-forming osteoblasts and bone-resorbing osteoclasts are mainly responsible for bone remodeling. Osteoblasts are believed to be derived from undifferentiated mesenchymal cells, which further differentiate into osteocytes and are embedded in calcified tissues. Osteoclasts are multinucleated cells present only in bone. It is believed that osteoclast progenitors are of hemopoietic origin, and they are recruited from hemopoietic tissues such as bone marrow and circulating blood to bone. Osteoclast progenitors then proliferate and differentiate into mononuclear preosteoclasts and fuse with each other to form multinucleated osteoclasts. ...