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Biomedical subjects

A Baranowski

Publications and source records attributed to A Baranowski.

11 recordsLinked to original sources
PubMed1999

Sensory threshold changes without initial pain or alterations in cutaneous blood flow, in the area of secondary hyperalgesia caused by topical application of capsaicin in humans.

Changes in von Frey hair perception, pricking pain, and vibration thresholds were examined in six healthy human adults, in the zone of secondary hyperalgesia, 45 min following the topical application of capsaicin at concentrations of 0.05 and 0.1 mg/ml. In two of these subjects, cutaneous blood flow was monitored at 10-min intervals, before, during and after capsaicin application, using laser Doppler perfusion imaging. Thresholds for all three parameters were significantly reduced after capsaicin treatment, in a dose-dependent manner. However, there was no visible skin flare, and no change in cutaneous blood flow at these doses of capsaicin. The effects on von Frey perception threshold and vibration threshold have not been demonstrated previously, and may be indicative of central changes, initiated by afferent fibres (presumably C fibres) that are not vasoactive.

Administration, Topical↗
PubMed1993

A new model of vasculogenesis and angiogenesis in vitro as compared with vascular growth in the avian area vasculosa.

In cultures of dissociated quail epiblast the basic constituents of the vascular system, blood cells and endothelial cells can be induced by basic fibroblast growth factor (Flamme and Risau, Development, 116: 435-439, 1992). As we show here, in those cultures three types of vascular plexus differentiate spontaneously under different culture conditions: At the 3rd day a vascular plexus appears in situ closely resembling the vascular plexus of the quail area opaca vasculosa (vasculogenesis). Vascular sprouts are formed, extending long filopodia at their tips. Such filopodia are shown to build the first intervascular bridges in the growing vascular plexus of the area vasculosa at embryonic day 3. Connections of filopodia turn out to be precursors of new capillaries interconnecting pre-existing blood vessels (angiogenesis). Two further types of in vitro capillary plexus differentiate in long term endothelial cell cultures derived from induced angioblasts. Whereas one closely resembles so-called angiogenesis in vitro, the third type comprises mainly multinucleated giant endothelial cells lining loop like capillaries and represents a differentiation of aging endothelial cell culture. Thus, the present in vitro model is an approach to the sequence of angioblast induction, vasculogenesis, and angiogenesis.

Animals↗
PubMed1989

[Synthesis of derivatives of 2,4-bis(arylmethino)-8-butyl-8- azabicyclo[3.2.1]octan-3-one].

In the frame-work of continued search for novel compounds with potential cholagogic or antitumour activity, some derivatives of 2,4-bis-(arylmethino)-8-butyl-8-azabicyclo[3.2.1]octan-3-one were synthesized. 8-Butyl-8-azabicyclo[3.2.1]octan-3-one was condensed with selected tolualdehydes, methoxybenzaldehydes and chlorobenzaldehydes, as well as with piperonal, furfural, dimethylaminobenzaldehyde, 3-pyridine-carboxaldehyde and 4-pyridine-carboxaldehyde. Products of these reactions were isolated in the form of free bases or their hydrochlorides. The obtained compounds were subjected to pharmacological studies. Two as yet investigated compounds failed to induce statistically significant increase in the volume of secreted bile, but one of them was found to display cholinergic activity.

Animals↗
PubMed1982

Connective tissue responses to oxysterols.

We studied the effect of sterols and oxidized sterols on promoting tissue inflammation and necrosis, and on causing cell death in tissue culture. The cells studied were mouse fibroblasts and macrophages, and pig vascular smooth muscle. The lipid preparations were dibromide-purified cholesterol, air-oxidized cholesterol, 25-hydroxycholesterol, cholesterol-5alpha, 6 beta-epoxide and cholestane 3 beta, 5 alpha, 6 beta-triol. Of these, the triol was most active in its cytopathic effect on cells in culture, in size of granuloma formation and in producing necrosis. The epoxide, 25-hydroxycholesterol and air-oxidized cholesterol produced rather less effect on tissues and cultures than the triol, but more than purified cholesterol and the control. The results are considered in relation to the presence of oxysterols in stored foodstuffs and their possible presence over the surface of cholesterol crystals in the tissues.

Animals↗