Search results for "VITRO"
showing 10 items of 2786 documents
Lack of binding of gestodene to estrogen receptor in human breast cancer tissue
1990
Competition studies with progesterone and estradiol receptors of human myometrial tissue as well as of mammary cancer tissue showed that gestodene bound with high affinity to the progesterone receptor, as did other synthetic and natural progestogens. However, gestodene did not bind to the estradiol receptor. The relative binding affinities of all tested synthetic and natural ligands showed no organ-specific differences and no differences between neoplastically transformed and normal tissues.
Histamine-sensitive adenylate cyclase of human gastric mucosa: a model for H2-receptor excitation.
1978
Recent studies revealed that human gastric mucosa contains a histamine-sensitive adenylate cyclase which is almost completely localized within the acid-secreting area of the stomach. In an attempt to further characterize the effector system of histamine’s action, we compared the effects of H 1 — and H 2-receptor agonists upon the adenylate cyclase in human fundic gastric mucosa.
Oxygen and glucose deprivation induces major dysfunction in the somatosensory cortex of the newborn rat
2005
The mechanisms and functional consequences of ischemia-induced injury during perinatal development are poorly understood. Subplate neurons (SPn) play a central role in early cortical development and a pathophysiological impairment of these neurons may have long-term detrimental effects on cortical function. The acute and long-term consequences of combined oxygen and glucose deprivation (OGD) were investigated in SPn and compared with OGD-induced dysfunction of immature layer V pyramidal cortical neurons (PCn) in somatosensory cortical slices from postnatal day (P)0-4 rats. OGD for 50 min followed by a 10-24-h period of normal oxygenation and glucose supply in vitro or in culture led to pron…
Endoscopic Ultrasonography in the Diagnosis of Regional Lymph Nodes in Esophageal and Gastric Cancer - Results of Studies in Vitro
1993
A total of 90 regional lymph nodes (43 benign/47 metastatic) from 16 surgical resection specimens of patients with esophageal and gastric carcinoma were examined in vitro by endosonography. The validity of endosonographic criteria of lymph node dignity (size, echogenicity, internal echo pattern and margin structure) was assessed using computer-supported B-mode analysis and compared to histopathological results. Of 26 lymph nodes with a diameter of more than 10 mm, 19 were metastatic (72%). The subjective assessment of the internal echo pattern (homogeneity) and the node margins by an experienced observer allowed the diagnosis of metastatic lymph nodes, but there was a high proportion of fal…
Oral mucosa of coeliac disease patients produces antiendomysial and antitransglutaminase antibodies: the diagnostic usefulness of an in vitro culture…
2007
Summary Background Antiendomysial (EmA) and antitransglutaminase (anti-tTG) antibodies are the most specific indirect marker of coeliac disease (CD). It is not known whether the oral mucosa of patients with CD is able to produce these antibodies or not. Aims To evaluate the ability of the oral mucosa of patients with CD to produce antibodies in an in vitro culture system. Patients and methods Twenty-eight patients with new diagnosis of CD (15 adults and 13 children) and 14 adult subjects with other diseases (controls) were studied. All underwent oral mucosa biopsy and subsequent EmA and anti-tTG assays on the mucosa culture medium. Results Sensitivity and specificity of EmA and anti-tTG…
Biological interactions between calcium silicate-based endodontic biomaterials and periodontal ligament stem cells: A systematic review of in vitro s…
2021
Background Most recently, the biological interactions, that is cytocompatibility, cell differentiation and mineralization potential, between calcium silicate-based biomaterials and periodontal ligament stem cells (PDLSCs) have been studied at an in vitro level, in order to predict their clinical behaviour during endodontic procedures involving direct contact with periodontal tissues, namely root canal treatment, endodontic surgery and regenerative endodontic treatment. Objective The aim of the present systematic review was to present a qualitative synthesis of available in vitro studies assessing the biological interaction of PDLSCs and calcium silicate-based biomaterials. Methodology The p…
Calcium Dependence of the Mechanical Response Evoked by Okadaic Acid in Smooth Muscle
1995
The effects of okadaic acid (OA), obtained from a culture of the marine dinoflagellate Prorocentrum Lima were studied on isolated strips of rat myometrium. The contractile response evoked by OA at 5, 10, and 20 μM in normal physiological solution was unaffected in the presence of tetrodotoxin (10 μM), indomethacin (3 μM), or a cocktail of antagonists which blocked muscarinic, adrenergic, histaminergic, serotonergic, and opioid receptors. Similarly, the response to OA was unaffected in the presence of nifedipine at a concentration (1 μM) which completely or highly blocked the response to KCl (60 mM), oxytocin (1 μM), or acetylcholine (100 μM). In a Ca 2+ -free 1 mM EGTA-containing solution, …
Selective inhibition of calcium entry induced by benzylisoquinolines in rat smooth muscle.
1992
Abstract The mechanism of relaxant activity of six benzylisoquinolines was examined in order to determine the minimal structural requirements that enable these compounds to have either a non-specific action like papaverine or an inhibitory activity on calcium entry via potential-operated channels. All the alkaloids tested totally or partially relaxed KCl-depolarized rat uterus and inhibited oxytocin-induced rhythmic contractions. Only glaucine and laudanosine inhibited K+-induced uterine contractions more than oxytocin-induced uterine contractions. In Ca+-free medium, sustained contractions induced by oxytocin or vanadate were relaxed by the alkaloids tested except for glaucine and laudanos…
Epithelium-derived inhibition of [3H]acetylcholine release from the isolated guinea-pig trachea
1990
To investigate presynaptic, regulatory mechanisms on parasympathetic nerve fibres innervating the airways, the release of newly-synthesized [3H]acetylcholine from the isolated trachea was studied. Reverse phase HPLC followed by liquid scintillation spectrometry was used to separate and quantify the radioactive compounds choline, phosphorylcholine and acetylcholine in the incubation medium and the tissue. During the incubation of the tracheae with [3H]choline a significant synthesis of [3H]acetylcholine (35,000 dpm/preparation) and [3H]phosphorylcholine (500,000 dpm/preparation) occurred. In epithelium-deficient tracheae the formation of [3H]phosphorylcholine was enhanced, whereas the conten…
Effects of dopamine in isolated rat colon strips.
2005
The aim of the present work is to investigate the effects of dopamine on isolated rat colon strips, and whether dopamine receptors are involved in these effects. Experiments on spontaneous motility and under potassium contraction were performed with dopamine and isoprenaline, both in the absence and presence of antagonists (distal colon strips, isotonic recording, Tyrode solution, 31 °C, 1 g of resting tension). At higher concentration (10–4mol/L), dopamine abolished spontaneous motility of the rat colon and this effect was not modified by antagonists. In isolated rat colon strips that were depolarized with potassium, dopamine produced concentration-dependent relaxation, without significant…