42 Result(s)
within
H.-J. Merker
English
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Article
Redifferentiation of dedifferentiated human chondrocytes in high-density cultures
High-density cultures are widely used as an in vitro model for studies of embryonic cartilage formation. In the present study we investigated the suitability of high-density cultures for the redifferentiation...
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Article
Quinolone-induced arthropathy: exposure of magnesium-deficient aged rats or immature rats, mineral concentrations in target tissues and pharmacokinetics
Quinolone treatment or magnesium deficiency induce identical cartilage lesions in juvenile rats and show additive arthropathogenic effects. It has been shown previously that neither condition is arthropathoge...
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Article
Effects of Magnesium Deficiency on Magnesium and Calcium Content in Bone and Cartilage in Develo** Rats in Correlation to Chondrotoxicity
Quinolone-induced arthropathy has been described in juvenile rats between 3 and 6 weeks of age, but not in adult rats. The mechanism of this chondrotoxic effect is probably related to the Mg2+-chelating properti...
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Article
Electron microscopic and immunomorphological investigations on the mucosa of the human paranasal sinuses
The morphology of the mucosa from the human paranasal sinuses was investigated by electron microscopy. A total of 27 specimens was taken from 11 patients following midfacial fractures. All tissue samples were ...
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Article
Intracellular collagen-like material in mouse embryonic mesenchymal cells incubated with TNF-α and IL-1β in organoid culture
Blastemal cells of embryonic mouse limb buds (day 12) were cultivated in organoid cultures in the presence of the human recombinant cytokines interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α). The ef...
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Article
Integrins on joint cartilage chondrocytes and alterations by ofloxacin or magnesium deficiency in immature rats
Recently, we showed that magnesium deficiency induces lesions in knee joint cartilage from 5-week-old rats that are very similar to ofloxacin-induced cartilage defects. We concluded that quinolone-induced art...
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Article
Electron and fluorescence microscopic investigations on composition and structure of the epithelial basement membrane of the human inferior nasal concha
Light and electron microscopic as well as immunohistochemical investigations were performed on the basement membrane (BM) of the nasal mucosa from the inferior nasal conchae of 20 patients, aged 15–50 years. T...
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Article
Cell shape and arrangement of cultured aortic smooth muscle cells grown on collagen gels
Aortic smooth muscle cells (SMC) grown on conventional plastic culture dishes have morphological and functional properties of dedifferentiated cells in sub-culture. We examined the influence of collagen gels o...
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Article
Localization of collagen type VI in articular cartilage of young and adult mice
Collagen type VI was demonstrated immunomorphologically in articular cartilage (distal femur) of young (2–8 weeks) and adult mice by fluorescence and electron microscopy (gold-labelled second antibody—sandwich...
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Article
Extracellular matrix in the rat spiral limbus
The matrix of the spiral limbus is obviously a special form of the intercellular substance. In the present study, the rat's spiral limbus was investigated by electron microscopy after fixation with ruthenium r...
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Article
Intercellular communication between cultured granulosa cells of the marmoset (Callithrix jacchus)
The influence of follicle-stimulating hormone, forskolin, insulin-like growth factor type I, epidermal growth factor, and 12-tetradecanoyl-phorbol-13-acetate on marmoset granulosa cell communication via gap ju...
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Article
Development of the basal lamina in xenografted human carcinomas: an ultrastructural and immunohistochemical study
The development of the basal lamina (BL), the key structure of the basement membrane (BM), was investigated in three xenografted human carcinomas of the sigmoid colon (CA 1), the lung (L 261), and the hypophar...
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Article
Ultrastructural and histochemical characterization of marmoset (Callithrix jacchus) Leydig cells during postnatal development
Leydig cell development was investigated in the marmoset (Callithrix jacchus) testis from 24 h post partum (pp) up to sexual maturity, using ultrastructural and histochemical methods.
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Article
Ofloxacin in juvenile non-human primates and rats. Arthropathia and drug plasma concentrations
Arthropathia in juvenile animals is the most important toxic effect induced by quinolones. We conducted pharmacokinetic and morphological studies with ofloxacin on non-human primates (Callithrix jacchus, Marmoset...
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Article
Influence of 13-cis and all- trans retinoic acid on rat embryonic development in vitro: correlation with isomerisation and drug transfer to the embryo
In vitro experiments using whole rat embryo cultures show that all -trans retinoic acid (all- trans RA) administered at low concentrations (30 ng/ml culture medium) is 10 times more active than 13-cis retinoic ac...
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Article
Enhancement of maternal and fetal nephrotoxicity of salicylate by zinc deficiency
An oral dose of 700 mg/kg salicylic acid was given to normal and Zn-deficient rats at day 16 of gestation. Maternal and fetal kidneys were studied at day 19 of gestation. Zn-deficiency did not cause any lesion...
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Article
Enzymatic and morphological response of the thymus to drugs in normal and zinc-deficient pregnant rats and their fetuses
In the thymus of normally fed pregnant rats the plasma membrane enzymes dipeptidyl peptidase IV (DPP IV) and alkaline phosphatase (alP) were found in cortical and medullary lymphocytes (thymocytes). Plasma mem...
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Article
The basement membrane of the persisting maternal blood vessels in the placenta of Callithrix jacchus
Formation and morphology of the thickened basement membrane-like layer around the persisting maternal vessels of the Callithrix jacchus placenta were investigated from day 45 until term (day 142) using light, ...
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Chapter and Conference Paper
Production and Formation of the Basal Lamina
The chemical composition of the basal lamina (BL), its morphology, localization and behaviour under experimental and pathological conditions have been investigated extensively over the last few years (Hawkes a...
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Chapter and Conference Paper
Cell-Matrix Interaction in the Differentiation of the Intestinal Epithelium
Epithelio-mesenchymal interactions are a prerequisite for the normal cytodifferentiation of all epithelial tissues during ontogenesis. Whereas the pioneering investigators reported on the necessity of the mere...
