1,720,991 research outputs found
Stimulation of endogenous adenosine release by oral administration of quercetin and resveratrol in man
No full textEpidemiological evidence indicates that moderate alcohol consumption is associated with a significant decrease in the incidence of certain cardiovascular disorders, which can lead to impaired quality of life and to death. However, there are no objective data suggesting a cause-effect relationship and detailed research based on definitive working hypotheses is needed. We tested two flavonoids in man and found that these substances can belong, at least in part, to a wine-dependent mechanism, which leads to increased adenosine plasma levels. If these results could be confirmed by analyzing all the possible influences leading to blood nucleoside increase, a hypothesis of diet-dependent cellular preconditioning could be discussed
The calcium I.V. infusion induces an increase of adenosine plasma levels and a coronary steal phenomenon in humans
No full textSystemic adenosine increase during cold pressor test is dependent on sympathetic activation
No full text1. Following local vasoconstriction-inducing stimuli, such as the cold pressor test (CPT), significant changes occur in haemodynamics, with a rise in arterial blood pressure and heart rate (HR) due to the activation of the sympathetic nervous system. Among the compensatory mechanisms to local ischaemia, the endogenous nucleoside adenosine (ADO) has been suggested to play a relevant role by contributing to sympathetic stimulation. The possibility was investigated that CPT-induced increases in plasma ADO levels were not only an expression of the increased production of ADO in the ischaemic area, but also a consequence of systemic sympathoexcitatory mechanisms, thus showing a bidirectional involvement of the mechanisms of ADO formation. 2. The CPT was performed in 15 volunteers and mean arterial blood pressure (MABP) and HR were evaluated, together with plasma levels of noradrenaline (NA) and ADO in the tested and contralateral arm. The 15 subjects were then divided into three groups of five that were treated with either 5 mg transdermal clonidine weekly, 100 mg atenolol daily or 600 mg aminophylline twice daily. After 1 week treatment, the same test was repeated in the respective groups. 3. The CPT induced a rise in MABP and HR and an increase in plasma levels of NA and ADO. Increases in ADO were more pronounced in the tested arm. Clonidine blunted the haemodynamic response and NA release, while increases in ADO increase were reduced to a greater extent in the contralateral arm rather than the tested arm. Atenolol only affected MABP and HR without any effect on NA and ADO levels. Theophylline did not show any effect on CPT-induced changes. 4. In conclusion, local vasoconstriction and ischaemia induced in one arm following CPT are associated with haemodynamic changes dependent on the activation of the sympathetic system. The observed increase in plasma levels of ADO seems to be, in part, a direct expression of local responses to ischaemia (predominant in the tested arm), but also appears as the consequence of systemic sympathoexcitatory mechanisms. Such increases in ADO are not dependent on a β1-adrenoceptor-mediated mechanism. Finally, theophylline, at a therapeutic dose, has no effect on the response to CPT
Immunodeficiency for surgical trauma and anesthesiological procedures. A treatment with Timopoietina pentapeptide [Modello di immunodeficienza acquisita da anestesia e procedure chirurgiche. Influenza di un trattamento con timopoietina pentapeptide (TP5)]
No full textDiscoid lupus erythematosus of the vulva
No full textGenital involvement is a rare manifestation in discoid lupus erythematosus (DLE) and systemic lupus erythematosus (SLE), and there are few reports on vulvar clinical features. We describe a 41-year old Caucasian woman with bilateral vulvar DLE. Although vulvar lesions in lupus are probably more common than is realized, the present report is the first case of genital DLE documented in a female
Effects ofthymopoietin pentapeptide on low reversible E-rosette forming cells of rheumatoidarthritis patients.-II) In vivo study
No full textEffect ofthymopoietin pentapeptide on low reversible E-rosette forming cells of rheumatoid arthritis patients. -I) In vitro study. arthritis patients. -I) In vitro study
No full textIncrease in plasma adenosine during brain ischemia in man: A study during transient ischemic attacks, and stroke
No full textAdenosine is a 'retaliatory metabolite' which accumulates during experimental brain ischemia and has vasodilatory and putative neuroprotective effects. The aim of this study was to assess whether human cerebral ischemia and necrosis - evaluated in the clinical models of transient ischemic attack (TIA) and stroke, respectively - acutely raise plasma adenosine levels. We studied 20 patients: 10 with TIA and 10 with stroke. In all, blood was serially sampled for assessment of plasma adenosine by an high-performance liquid chromatography method. Sampling occurred on peripheral blood during TIA and stroke upon admission, and serially thereafter every day up to 7 days and every other day up to 20 days. We found that in TIA and stroke patients, peripheral adenosine levels were increased to a similar extent upon admission (TIA = 264 ± 53 vs. stroke = 257 ± 60 nM, p = ns), peaked on the day 2 for TIA (300 ± 60) and on day 3 for stroke (289 ± 43) patients, and steadily decreased towards the normal range, reached by all TIA patients by day 5 and by stroke patients by day 15. Stroke and TIA are associated with a rapid increase in circulating plasma adenosine concentration in man, detectable in peripheral vein. The adenosine surge likely mirrors an increased production from the ischemic brain, and it lasts days (for TIA) and weeks (for stroke) after the acute event. (C) 2000 Elsevier Science Inc
Ultrastructural modifications of the platelet plasma-membrane in vascular diseases and the effect of carbochromen derivative as studied by freeze-fracture and computer measurement
No full textA high surface density of the openings of the surface connected canalicular system (SCCS) has been observed in the freeze-fractured plasma membrane of circulating platelets in rabbits fed an atherogenic diet and in hypercholesterolemic type IIa patients. In vitro tests have revealed a correlation between the increased surface density of the SCCS openings and the initial steps of platelet activation. 8-Chlorocarbochromen, a new drug which enhances the in vivo release of prostacyclin from the arterial wall, has been found to be effective in reducing the high surface density of SCCS openings in platelets of rabbits on an atherogenic diet. The present study shows that circulating platelets from patients with peripheral vascular disease present a high surface density of SCCS openings compared to that observed in control subjects. After a single oral administration of 8-chlorocarbochromen, a reduction of the high number of these openings has been observed. Likewise, beta-thromboglobulin levels were found to be high in the patients and to be significantly reduced after oral administration of the drug. This study shows ultrastructural modifications of platelets in conditions related to atherosclerosis and includes data on the effectiveness of 8-chlorocarbochromen in reducing the platelet activation of these patients
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