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Biomedical subjects

M Falciani

Publications and source records attributed to M Falciani.

At least 37 records · Page 2Linked to original sources

Elevated tissue factor and tissue factor pathway inhibitor circulating levels in ischaemic heart disease patients.

Several studies have shown that thrombosis and inflammation play an important role in the pathogenesis of Ischaemic Heart Disease (IHD). In particular, Tissue Factor (TF) is responsible for the thrombogenicity of the atherosclerotic plaque and plays a key role in triggering thrombin generation. The aim of this study was to evaluate the TF/Tissue Factor Pathway Inhibitor (TFPI) system in patients with IHD. We have studied 55 patients with IHD and not on heparin [18 with unstable angina (UA), 24 with effort angina (EA) and 13 with previous myocardial infarction (MI)] and 48 sex- and age-matched healthy volunteers, by measuring plasma levels of TF, TFPI, Prothrombin Fragment 1-2 (F1+2), and Thrombin Antithrombin Complexes (TAT). TF plasma levels in IHD patients (median 215.4 pg/ml; range 72.6 to 834.3 pg/ml) were significantly (p<0.001) higher than those found in control subjects (median 142.5 pg/ml; range 28.0-255.3 pg/ml). Similarly, TFPI plasma levels in IHD patients were significantly higher (median 129.0 ng/ml; range 30.3-316.8 ng/ml; p<0.001) than those found in control subjects (median 60.4 ng/ml; range 20.8-151.3 ng/ml). UA patients showed higher amounts of TF and TFPI plasma levels (TF median 255.6 pg/ml; range 148.8-834.3 pg/ml; TFPI median 137.7 ng/ml; range 38.3-316.8 ng/ml) than patients with EA (TF median 182.0 pg/ml; range 72.6-380.0 pg/ml; TFPI median 115.2 ng/ml; range 47.0-196.8 ng/ml) and MI (TF median 213.9 pg/ml; range 125.0 to 341.9 pg/ml; TFPI median 130.5 ng/ml; range 94.0-207.8 ng/ml). Similar levels of TF and TFPI were found in patients with mono- or bivasal coronary lesions. A positive correlation was observed between TF and TFPI plasma levels (r = 0.57, p<0.001). Excess thrombin formation in patients with IHD was documented by TAT (median 5.2 microg/l; range 1.7-21.0 microg/l) and F1+2 levels (median 1.4 nmol/l; range 0.6 to 6.2 nmol/l) both significantly higher (p<0.001) than those found in control subjects (TAT median 2.3 microg/l; range 1.4-4.2 microg/l; F1+2 median 0.7 nmol/l; range 0.3-1.3 nmol/l). As in other conditions associated with cell-mediated clotting activation (cancer and DIC), also in IHD high levels of circulating TF are present. Endothelial cells and monocytes are the possible common source of TF and TFPI. The blood clotting activation observed in these patients may be related to elevated TF circulating levels not sufficiently inhibited by the elevated TFPI plasma levels present.

Adult↗

Transglutaminase-synthesized spermine derivative of substance P recognizes rat portal vein neurokinin-3 receptors.

The effects of the transglutaminase-synthesized polyamine derivatives of Substance P (SP) have been further characterized by their ability to contract in vitro the rat portal vein strip (RPV), a pharmacological preparation particularly rich in NK-3 receptors. The effects of selective agonists of NK-1, NK-2 and NK-3 receptors [Sar9,Met(O(2))11]SP, beta-Ala8 NKA(4-10), and senktide respectively, were also evaluated by measuring RPV concentration-response curves. Peptide [GR-82334 (NK-1) and MEN-10,376 (NK-2)] and nonpeptide [WIN 51,708 (NK-1) and SR 142801 (NK-3)] NK receptor antagonists were used to confirm the participation of the different NK receptors to contractile response. Our results demonstrated that the spermine derivative of SP (Spm-SP), previously shown to be unable to recognize NK-1 and NK-2 receptors in some bioassays, contracts RPV (EC50 = 588 nM) better than the native neuropeptide (EC50 = 1120 nM). A pretreatment with thiorphan, an inhibitor of neutral endopeptidases, significantly reduced such a difference. While this inhibitor shifts the SP concentration-response curves to the left (EC50 = 720 nM) the action of Spm-SP and [Sar9,Met(O(2))11]SP were completely thiorphan-resistant. In the absence of thiorphan we found the following rank order of potency: senktide > > beta-Ala8 NKA(4-10) > [Sar9,Met(O(2))11]SP = Spm-SP > SP. Among the mentioned NK receptor antagonists, only the selective NK-3 receptor antagonist, SR 142801, shifted to the right Spm-SP and [Sar9,Met(O(2))11]SP concentration-response curve, showing pKB values of 5.84 and 5.88, respectively. Therefore, the reported results suggest that the introduction of a Spm moiety into the SP alters the parent peptide molecule by increasing its affinity for NK-3 receptors and/or by preventing its degradation by some proteolytic enzymes.

Androstanes↗

Identification of candidates for prevention of venous thromboembolism.

The rationale for prophylaxis of venous thromboembolism (VTE) is based on the frequently clinically silent nature of the disease. A number of risk factors for VTE have been known for a long time, even if some of them are still controversial. Many studies have been performed in the surgical field, and have established different risk classes for VTE. Such risk stratification is especially determined by type of surgery and to some extent by personal characteristics of patients, and it defines operations at high, intermediate, and low risk for VTE. According to this classification, prophylaxis of VTE is mandatory in some cases, less useful in others. Less information is available on medical diseases, in which the clinical conditions and the intrinsic characteristics of patients determine the class of risk for VTE. Different strategies for identifying patients who should undergo prophylaxis have been proposed based on risk factor evaluation in the individual patient. However, even if such an approach may be of help for the physician, its validity is still impaired by the difficulty of taking into account all of the variables possibly involved in VTE occurrence.

Humans↗

Role of nitric oxide in a nonseptic shock model induced by zymosan in the rat.

Nitric oxide (NO) is a short-lived mediator, the synthesis of which is induced by various cytokines during inflammatory processes. Recently, it has been proposed that zymosan, a nonbacterial agent, causes inflammation by inducing the production of various cytokines and proinflammatory mediators. In the present study we investigated the role of NO in a nonseptic shock model induced by zymosan administration in the rat. Administration of zymosan (500 mg/kg, intraperitoneally) in the rat induced acute peritonitis, as assessed by a marked increase in the leukocytes count in the exudate, as well as by an increase in the exudate nitrate/nitrite concentration. Zymosan-treated rats developed a severe hypotension and showed signs of systemic illness, significant loss of body weight, and a high mortality rate (53% of animals died within 72 h). Elevated plasma levels of nitrite and nitrate were also observed in zymosan-treated rats compared with control rats (67 +/- 4 microM and 23 +/- 2 microM, respectively; p < .01). In ex vivo experiments, vascular reactivity was studied in thoracic aorta rings of zymosan-treated rats. The contractile responses to norepinephrine (100 nM) and endothelin-1 (5 nM) were significantly reduced. An impairment of the endothelial-dependent relaxation in response to acetylcholine was also observed. Pretreatment of zymosan-shocked rats with NG-nitro-L-arginine methyl ester (L-NAME) or NG-monomethyl-L-arginine (L-NMA), (10 mg/kg, subcutaneously, 15 min before zymosan) decreased mortality, prevented the development of peritonitis, improved ex vivo vascular reactivity, and significantly reduced hypotension. Our data suggest that overproduction of NO plays a role in the zymosan-induced peritonitis and cardiovascular derangements in the rats.

Acute Disease↗

Distribution of endothelin-1-receptor subtypes in rat portal vein.

Endothelin-1 (ET-1), a potent vasoactive peptide, was first isolated from cultured porcine endothelial cells. Subsequent studies revealed the existence of two additional related peptides, ET-2 and ET-3, and at least two distinct ET-receptor subtypes, ETA (selective for ET-1) and ETB (nonselective for ET isopeptides). These isopeptides and receptors are widely distributed in many tissues and are involved in numerous biological responses. The aim of this study was to identify the eventual distribution of the two distinct endothelin-receptor subtypes in isolated endothelium-denuded rat portal vein rings (PVRs) and strips (PVSs). BQ-123 (0.6, 1, and 6 microM) and PD-145065 (0.06, 0.1, 0.6, and 6 microM) were used to differentiate the subtypes because they are selective antagonists for ETA and nonselective antagonists for ETA-ETB receptors, respectively. To characterize the ET receptors further, sarafotoxin-S6c (a selective ETB-receptor agonist) and IRL-1038 (a selective ETB-receptor antagonist) were used. In PVRs, cumulative additions of ET-1 (0.1-100 nM) caused graded and slow contractions and potentiated spontaneous rhythmic contractions. The EC50 values and maximal response to 100 nM of ET-1 were 2.72 nM and 0.75 g, respectively (n = 7). PVSs showed ET-1 EC50 values very similar to those of PVRs, but Emax values to 100 nM of ET-1 were significantly lower (Emax = 0.33 g; n = 7). Moreover, ET-1 clearly increased the amplitude and frequency of spontaneous contractions in both types of specimens, although these were greater in the PVSs. Thirty-minute incubation with the selective ETA-receptor antagonist BQ-123 blunted ET-1-induced effects in PVS specimens but only weakly antagonized ET-1-induced contractions in PVRs. In contrast, the nonselective ETA-ETB-receptor antagonist PD-145065 significantly shifted the ET-1 concentration-response curve to the right in PVRs and partially inhibited ET-1 effects in PVSs. Moreover, sarafotoxin-S6c (0.1-100 nM) contracted PVRs and PVSs in a similar manner to ET-1; its effects were antagonized by IRL-1038 only at the PVR level. The differences observed in PVR and PVS specimens in response to agonists and antagonists of ET confirmed the great heterogeneity of endothelin-sarafotoxin receptors. In our experimental models, functionally ETB-like (or non-ETA) receptors seem mostly to mediate vasoconstriction.

Animals↗

Beta-adrenoreceptor blocking heterocyclic oximes and ethers.

This paper reports synthesis and pharmacological properties of thienyl, pyrrol, indolyl and benzofuryl-O-(3-alkylamine-2-hydroxypropyl)oximes and some 3-(3-alkylamine-2-hydroxypropyl)alkyloxy indoles aiming to study the influence of five membered and condensed heterocyclic substituents on the beta-adrenoreceptor inhibiting potency. All heterocyclic derivatives synthesized (1-17) were less active than the reference propranolol on the rat heart, while showed a comparable potency on the guinea pig trachea, exhibiting a significant beta 2-selectivity. The low beta-blocking potency of the five membered derivatives seemed to confirm the negative influence of the polarization of the oximic carbon in the binding with non polar region of the beta-adrenoreceptor. Another important interaction could take place with the enzyme adenyl-cyclase which is responsible of the signal of transduction. It could be hypothesized that the heteroatom of the heterocyclic nucleus acted as an electron-donor group and engaged a coordinative bond with magnesium atom present on the adenylcyclase system, responsible of the agonist activity. The pharmacological in vivo experiments and the binding results were in accordance with the in vitro data.

Adrenergic beta-Antagonists↗

Cycloocta[b]pyran derivatives with local anesthetic, platelet antiaggregating and other activities.

The synthesis of some N,N-disubstituted 4-amino-5,6,7,8,9,10-hexahydro-3- phenyl-2H-cycloocta[b]pyran-2-ones by reaction of phenylchloroketene with a series of N,N-disubstituted 2-aminomethylenecyclooctanones, followed by dehydrochlorination in situ of the primary adducts with DBN, is described. The dimethylamino derivative showed a local anesthetic activity in mice superior to that of lidocaine, and some compounds exhibited a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as weak antiarrhythmic and antiinflammatory activities in rats.

Anesthetics, Local↗

3,5-Diphenyl-1H-pyrazole derivatives. XII. N-substituted 4-amino-1-(2-hydroxy- or 2-alkylaminoethyl)-3,5-diphenyl-1H-pyrazoles with local anesthetic, analgesic and platelet antiaggregating activities.

The synthesis of 4-amino-3,5-diphenyl-1H-pyrazole-1-ethanol, as well as of their N-methyl, N-ethyl and N,N-dimethyl derivatives is described. A series of 1-(2-alkylaminoethyl)-3,5-diphenyl-1H-pyrazole-4-amines and of N-substituted 4-dimethylamino-3,5-diphenyl-1H-pyrazole-1-ethanamines were also prepared. Some of the above compounds showed remarkable local anesthetic, analgesic and in vitro platelet antiaggregating activities, as well as moderate antiinflammatory and antipyretic activities in rats and mice.

Analgesics↗

O-[omega-(Dialkylamino)alkyl]oximes of (+)-1,7,7-trimethylbicyclo [2.2.1]heptan-2-one with hypotensive, antiinflammatory, analgesic, local anesthetic and other activities.

The synthesis of (+)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one O-[omega-(dialkylamino)alkyl]oximes by reaction of (+)-camphoroxime sodium salt with a series of omega-(chloroalkyl)dialkylamines in DMF solution is described. Some of the above compounds showed strong hypotensive, antiinflammatory, analgesic and local anesthetic activity in rats and mice, as well as moderate antiarrhythmic, antipyretic and in vitro platelet antiaggregating activity.

Analgesics↗

5-Substituted 2,3-dihydro-6-mercapto-1,3-diphenyl-2-thioxo-4(3H)-pyrimidinones and their 6-(acylthio) derivatives with platelet antiaggregating, antiinflammatory, antiarrhythmic, antihyperlipidemic and other activities.

The synthesis in excellent yields of 2,3-dihydro-6-mercapto-1,3,5-triphenyl-2-thioxo-4(3H)-pyrimidinone 3 and 5-ethoxycarbonyl-2,3-dihydro-6-mercapto-1,3-diphenyl-2-thioxo-4(3H )- pyrimidinone 4 by reaction of methyl phenylacetate or diethyl malonate, respectively, with phenyl isothiocyanate (3 molar equivalents) and sodium hydride (2 molar equivalents) in DMF solution is described. Acylation of 3 and 4 with acyl chlorides gave, generally in satisfactory yields, 6-acylthio derivatives 13 and 14. Some of the above compounds showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as remarkable antiinflammatory, antiarrhythmic, local anesthetic and antihyperlipidemic activities in rats and in mice. Weak anticonvulsant and hypoglycemic activities were also detected.

Anesthetics, Local↗

Synthesis and pharmacological activities of ethyl 5-cyano-1,6-dihydro-6-oxo-2-(2,3,4-pyridyl)-3-pyridinecarboxylates and derivatives.

The synthesis of ethyl esters of 5-cyano-1,6-dihydro-6-oxo-3-pyridinecarboxylic acids carrying as 2-substituent the 2-,3- or 4-pyridyl group is described. By alkaline hydrolysis followed by acidification, these esters gave the corresponding carboxylic acids, which were decarboxylated to 1,2-dihydro-2-oxo-6-(2,3,4-pyridyl)-3-pyridinecarbonitriles. As milrinone analogues, the above compounds were tested on contractile activity and frequency rate of spontaneously beating atria from reserpine-treated guinea-pigs. Ethyl 5-cyano-1,6-dihydro-6-oxo-2-(2-pyridyl)-3-pyridinecarboxylate showed an appreciable positive inotropic activity, although inferior to that of milrinone; moreover, some other compounds bearing the above 2-substitution pattern showed interesting antiinflammatory, analgesic and hypotensive activity.

Analgesics↗

Effects of some antineoplastic drugs (vincristine, doxorubicin and epirubicin) on human platelet aggregation.

The effects of some antineoplastic drugs (vincristine, doxorubicin and epirubicin) on collagen- and ADP-induced human platelet aggregation are investigated. Platelet rich plasma (PRP) and platelet poor plasma (PPP) from healthy male and female donors were used. The PRP was adjusted with analogous PPP to 300,000 platelets/microliters. Platelet aggregation was studied according to Born's turbidimetric technique using an Aggrecorder II PA 3220 with collagen at a concentration of 10 micrograms/ml and ADP at a concentration of 30 microM. Vincristine, doxorubicin and epirubicin significantly (p < 0.01) inhibited collagen- and ADP-induced platelet aggregation. The vincristine induced inhibition was higher than that induced by doxorubicin or epirubicin. The effects of doxorubicin and epirubicin were more intense on ADP-induced platelet aggregation than on the collagen induced one. Moreover, the doxorubicin inhibition of ADP-induced platelet aggregation was greater than the epirubicin one. In conclusion, our study shows that vincristine, doxorubicin and epirubicin inhibit human platelet aggregation. The present results may improve the therapeutic use of these drugs since it has been clearly shown that drugs with antiplatelet activity could block metastases.

Adenosine Diphosphate↗

Effects of the intracerebroventricular administration of ketamine on centrogenic arrhythmias in anesthetized rats.

In urethane anesthetized rats the icv (lateral cerebral ventricle) administration of ketamine, at the highest utilized doses, induced bradypnea and sinus bradycardia in spontaneously breathing rats. Moreover, it partially antagonized the arrhythmogenic activities of sodium glutamate and sodium aspartate, as well as desipramine and ouabain. From these results, we conclude that ketamine had an inhibitory effect on the centrogenic arrhythmias not only acting at the level of NMDA subtype receptor, but also at beta 1 adrenergic central receptors. Moreover at high doses, ketamine can also induce centrogenic arrhythmias in spontaneously breathing rats.

Anesthesia↗

1-Aryl-1H-pyrazole-5-acetic acids with antiinflammatory, analgesic and other activities.

Reaction of methyl 4-methoxy-2-dimethylaminomethylene-3-oxobutanoate with arylhydrazines gave methyl 1-aryl-5-(methoxymethyl)-1H-pyrazole-4-carboxylates 1 in high yields. Esters 1 were hydrolyzed to the relative carboxylic acids, which were converted by heating to 1-aryl-5-(methoxymethyl)-1H-pyrazoles 3 in good yields. Reaction of 3 with hydrobromic acid afforded the intermediate 1-aryl-5-(bromomethyl)-1H-pyrazoles, which were converted with potassium cyanide to 1-aryl-1H-pyrazole-5- acetonitriles, whose hydrolysis gave the required 1-aryl-1H-pyrazole-5-acetic acids. Some acids 5 showed a strong antiinflammatory and analgesic activity in rats and mice, respectively, as well as moderate antipyretic and in vito platelet antiaggregating effects.

Acetates↗

O-(2-dialkylaminoethyl)oximes of 5-(arylmethylene)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ones with hypotensive, antiarrhythmic and other activities.

The synthesis of some O-(2-dialkylaminoethyl)oximes of 5-[(4-methoxy- or 4-methylthiophenyl)methylene]-1,3,3-trimethyl-2-oxabicyclo[2.2.2] octan-6-ones 5 by reaction of the corresponding oximes as sodium salts with the appropriate 2-chloroethyldialkylamine in dry ethanol solution is described. Some aminoethers 5 showed appreciable hypotensive and antiarrhythmic activities in rats, as well as a weak platelet antiaggregating activity in vitro and a moderate infiltration anesthesia in mice.

Anesthetics, Local↗

Ethyl or methyl 6-substituted 3-(benzoylamino)-2-oxo-2H-pyran-5-carboxylates and 3-(benzoylamino)-7,8-dihydro-2H-1-benzopyran-2,5(6H)-diones with local anesthetic, platelet antiaggregating and other activities.

The synthesis of ethyl or methyl 6-substituted 3-(benzoylamino)-2-oxo-2H-pyran-5-carboxylates 2 and 3-(benzoylamino)-7,8-dihydro-2H-1-benzopyran-2,5(6H)-diones 4 by reaction of hippuric acid in acetic anhydride with ethyl or methyl 2-dimethylaminomethylene-3-oxoalkanoates and 2-dimethylaminomethylene-1,3-cyclohexanediones, respectively, is described. Some compounds 2 and 4 showed a strong local anesthetic activity in mice and a platelet antiaggregating activity in vitro comparable to that of acetylsalicylic acid, as well as moderate analgesic, antiinflammatory and antiarrhythmic activities in rats and mice.

Anesthetics, Local↗

3-(Arylamino)-6,7-dihydro-6-methylpyrano[4,3-c]pyrazol-4(1H or 2H)-ones with antipyretic, analgesic, antiarrhythmic, hypotensive and other activities.

The synthesis of 3-(arylamino)-6,7-dihydro-6-methylpyrano[4,3-c]pyrazol-4(1H or 2H)-ones by reaction of N-aryl-5,6-dihydro-4-hydroxy-6-methyl-2-oxo- 2H-pyrano-3-carbothioamides with hydrazine is described. Some compounds showed remarkable antipyretic, analgesic, antiarrhythmic and hypotensive activity in rats or mice, as well as weak antiinflammatory, local anesthetic and in vitro platelet antiaggregating activity.

Aconitine↗