PubMed Health⌕ Search

Biomedical subjects

C Semeraro

Publications and source records attributed to C Semeraro.

At least 19 recordsLinked to original sources
PubMed2005

Impact of local guidelines and an integrated dispensing system on antibiotic prophylaxis quality in a surgical centre.

Surgical antibiotic prophylaxis is effective in preventing postoperative wound infections. Guidelines are designed to optimize antimicrobial use in this setting. The aim of this study was to assess antibiotic use in surgical prophylaxis in a surgical hospital before and after the implementation of both local antibiotic prophylaxis guidelines and a specific medication set for various surgical procedures. The appropriateness of surgical antibiotic prophylaxis increased from 50.9% in the pre-implementation stage to 94.9% in the postimplementation stage (P<0.001). The implementation of a multidisciplinary protocol and design of medication sets helped to improve the practice of surgical antibiotic prophylaxis.

Antibiotic Prophylaxis↗
PubMed2001

Impaired renal D(1)-like and D(2)-like dopamine receptor interaction in the spontaneously hypertensive rat.

D(1)-like (D(1), D(5)) and D(2)-like (D(2), D(3), D(4)) dopamine receptors interact in the kidney to produce a natriuresis and a diuresis. Disruption of D(1) or D(3) receptors in mice results in hypertension that is caused, in part, by a decreased ability to excrete an acute saline load. We studied D(1)-like and D(2)-like receptor interaction in anesthetized spontaneously hypertensive rats (SHR) by the intrarenal infusion of Z-1046 (a novel dopamine receptor agonist with rank order potency of D(3)> or =D(4)>D(2)>D(5)>D(1)). Z-1046 increased glomerular filtration rate (GFR), urine flow, and sodium excretion in normotensive Wistar-Kyoto rats but not in SHRs. The lack of responsiveness to Z-1046 in SHRs was not an epiphenomenon, because intrarenal cholecystokinin infusion increased GFR, urine flow, and sodium excretion to a similar extent in the two rat strains. We conclude that renal D(1)-like and D(2)-like receptor interaction is impaired in SHRs. The impaired D(1)-like and D(2)-like receptor interaction in SHRs is not caused by alterations in the coding sequence of the D(3) receptor, the D(2)-like receptor expressed in rat renal tubules that has been shown to be involved in sodium transport. Because the diuretic and natriuretic effects of D(1)-like receptors are, in part, caused by an interaction with D(2)-like receptors, it is possible that the decreased Z-1046 action in SHRs is secondary to the renal D(1)-like receptor dysfunction in this rat strain.

Animals↗
PubMed2000

Pharmacokinetics and disposition of the novel dopamine agonist Z-7760 in rat after intravenous and oral administration.

1. Z-7760 (S(-)-N-[N-2-phenylethyl)-6-hexylamino]-N-propyl-5,6-dihydroxy-1,2,3,4-tetrahydro-2-naphthylamine dihydrobromide) is a potent dopamine D-1 and D-2 agonist synthesized during a search for agents to treat heart failure. Reported is the fate of the drug in rat. 2. 3H-Z-7760 was administered p.o. and i.v. to male Sprague-Dawley rats (0.4 mg and 400 microCi/kg in 0.1% ascorbic acid) and venous blood samples collected at intervals up to 48 h. Comparison of the AUC for total 3H showed that 37% of an oral dose of Z-7760 was absorbed. The percentage plasma 3H present as the parent compound fell from 82% 30 min after i.v. dosing to 12% after 24 h. After oral dosing, the fraction of plasma 3H present as unchanged Z-7760 was < 5% and this was essentially unaltered throughout the study. The long terminal elimination phase evident from 6 h was notable after both routes of administration. 3. The bile duct-cannulated rat was given 3H-Z-7760 p.o. (0.4 mg and 40 microCi/kg) and bile was collected for up to 22 h. Biliary excretion accounted for 30% of the dose. No parent compound was detected in the bile. 4. In further studies, other rats were dosed p.o. or i.v. with 3H-Z-7760 (0.4 mg and 400 microCi/kg) and urine and faeces were collected daily for 3 days. The major route of excretion was the faeces with 94-97% 3H recovered after oral and 70-73% after i.v. dosing. A further 4-7% was recovered in the urine after oral and 12-13% after i.v. dosing. 5. After oral administration of Z-7760 (100 mg/kg, 40 microCi/kg) to rats, the major metabolites in the urine were identified as the 5-O-methyl and glucuronic acid conjugates of Z-7760 by LC and MS. The glucuronide was only seen in urine after oral administration but 5-O-methyl-Z-7760 was present in urine and faeces after both routes of administration. 6. The low bioavailability of Z-7760 is the consequence of its poor absorption from the gastrointestinal tract as well as extensive first-pass metabolism that further reduces systemic blood concentrations after oral administration.

2-Naphthylamine↗
PubMed1998

Disruption of the dopamine D3 receptor gene produces renin-dependent hypertension.

Since dopamine receptors are important in the regulation of renal and cardiovascular function, we studied the cardiovascular consequences of the disruption of the D3 receptor, a member of the family of D2-like receptors, expressed in renal proximal tubules and juxtaglomerular cells. Systolic and diastolic blood pressures were higher (approximately 20 mmHg) in heterozygous and homozygous than in wild-type mice. An acute saline load increased urine flow rate and sodium excretion to a similar extent in wild-type and heterozygous mice but the increase was attenuated in homozygous mice. Renal renin activity was much greater in homozygous than in wild-type mice; values for heterozygous mice were intermediate. Blockade of angiotensin II subtype-1 receptors decreased systolic blood pressure for a longer duration in mutant than in wild-type mice. Thus, disruption of the D3 receptor increases renal renin production and produces renal sodium retention and renin-dependent hypertension.

Angiotensin I↗
PubMed1998

The dopamine receptor agonist Z1046 reduces ischaemia severity in a canine model of coronary artery occlusion.

Z1046, (S)-6[[6-[[2-(2-methoxyphenoxy)ethyl]amino]propyl]amino]-5,6,7,8-tetra-h ydro-1,2-naphtalenediol dihydrochloride, is an agonist at both dopamine D1 and D2 receptors. Since stimulation of dopamine D2 receptors inhibits noradrenaline release, and because cardiac noradrenaline release has been implicated in the genesis of early ischaemia-induced, life-threatening ventricular arrhythmias, the effect of Z1046 has been examined for its effects on coronary artery occlusion in chloralose urethane anaesthetised mongrel dogs. Z1046 (10 microg kg(-1) intravenously or 1 microg kg(-1) by local intracoronary injection) decreased heart rate and reduced arterial blood pressure and coronary blood flow, effects prevented by the prior administration of domperidone (40 microg kg(-1) i.v.). The ischaemic changes induced by a 25-min occlusion of the left anterior descending coronary artery (including ST-segment elevation and ventricular ectopic activity) were much less marked in those dogs administered Z1046 and survival from the combined ischaemia reperfusion insult was increased from 7% to 36% (P < 0.05). These effects of Z1046 were partly attenuated by domperidone. We conclude that the anti-ischaemic effects of Z1046 are due to inhibition of cardiac sympathetic responses. Studies using rat isolated perfused mesenteric vascular bed preparations subjected to sympathetic nerve stimulation confirmed that Z1046 inhibits synaptic transmission without modifying vascular responses to noradrenaline.

Animals↗
PubMed1998

The effect duration of selective phosphodiesterase inhibitors in the guinea pig.

The beta-adrenoceptor agonists, isoprenaline, salbutamol and salmeterol, the non-selective phosphodiesterase (PDE) isoenzyme inhibitors, theophylline, trequinsin; the PDE3 isoenzyme inhibitor, milrinone; the PDE3/4 isoenzyme inhibitor, benzafentrine; and the PDE4 isoenzyme inhibitors, denbufylline, nitraquazone, RP 73401, Ro-20-1724, rolipram and tibenelast all induced concentration-dependent reversal of prostaglandin F2alpha-induced contraction of guinea-pig superfused trachea in vitro. The relaxant response of the non-selective PDE isoenzyme inhibitor trequinsin was slow in onset and demonstrated very slow recovery, similar to that observed with the long-acting beta2-adrenoceptor agonist, salmeterol and the PDE4 inhibitor, RP 73401. The relaxant agonists also significantly reversed bombesin-induced bronchospasm in anaesthetised guinea-pigs and there was a highly significant correlation between the ability of drugs to reverse PGF2alpha-induced contraction of guinea-pig isolated trachea in vitro and bombesin-induced bronchoconstriction in vivo. Furthermore, both salmeterol and trequinsin demonstrated long lasting bronchodilator responses consistent with the in vitro data. These results show that PDE isoenzyme inhibitors demonstrate different pharmacodynamic profiles that is not determined by PDE4 inhibitory potency and indicate that other factors may be important in this regard.

Adrenergic beta-Agonists↗
PubMed1998

Pharmacological evidence for the presence of a peripheral postjunctional D2-like dopamine receptor in rabbit splenic artery.

1. This study was designed to investigate the involvement of postjunctional D2-like receptors in a rabbit vasculature model used to evaluate the D1-like agonist activity. Dopamine, epinine and (-)-DP-5,6-ADTN, three mixed D1/D2-like agonists, fenoldopam and SKF 82958, two selective D1-like agonists and SKF 89124, a selective D2-like agonist, were administered cumulatively in precontracted and alpha/beta-blocked rabbit splenic artery rings in order to evaluate their D1-like-mediated vasorelaxant activity before and after pretreatment with the selective D2-like antagonist YM 09151-2 (1 nM). 2. Dopamine (pD2=6.35+/-0.09), epinine (pD2=6.73+/-0.13), (-)-DP-5,6-ADTN (pD2=7.56+/-0.09) and SKF 82958 (pD2=8.55+/-0.10) reversed completely the U46619-induced contracture whereas SKF 89124 was inactive up to 10 microM and fenoldopam acted like a partial agonist (pD2=8.31+/-0.09, alpha=0.62). The selective D2-like dopamine receptor antagonist YM 09151-2 (1 nM) significantly (P<0.05) potentiated the vasorelaxant activity of dopamine (pD2=7.01+/-0.07), epinine (pD2=7.14+/-0.08), (-)-DP-5,6-ADTN (pD2=8.19+/-0.09) and SKF 89124 (40% relaxation at 10 microM), whereas it did not alter the effects of fenoldopam (pD2=8.40+/-0.09, alpha=0.68) and SKF 82958 (pD2=8.58+/-0.08). 3. The D2-like antagonist YM 09151-2 induced the same degree of effect with all the substances tested in both endothelium-denuded and endothelium-intact preparations. 4. The selective D2-like dopamine receptor agonist SKF 89124 did not produce any intrinsic effect on the splenic artery, but was able to produce a rightward shift of the forskolin-induced relaxation. 5. The results of these experiments support the existence of a non-endothelial postjunctional D2-like dopamine receptor counteracting the D1-like-mediated vasodilatation in rabbit splenic artery, probably by the inhibition of adenylate cyclase.

Animals↗
PubMed1998

Effects of costimulation of dopamine D1- and D2-like receptors on renal function.

In vitro studies have suggested that dopamine D1- and D2-like receptors interact to inhibit renal sodium transport. We used Z-1046, a dopamine receptor agonist with the rank-order potency D3 >/= D4 > D2 > D5 > D1, to test the hypothesis that D1- and D2-like receptors interact to inhibit renal sodium transport in vivo in anesthetized rats. Increasing doses of Z-1046, administered via the right renal artery, increased renal blood flow (RBF), urine flow, and absolute and fractional sodium excretion without affecting glomerular filtration rate. For determination of the dopamine receptor involved in the renal functional effects of Z-1046, another group of rats received Z-1046 at 2 microgram . kg-1 . min-1 (n = 10) in the presence or absence of the D2-like receptor antagonist domperidone and/or the D1-like antagonist SCH-23390. Domperidone alone had no effect but blocked the Z-1046-mediated increase in urine flow and sodium excretion; it enhanced the increase in RBF after Z-1046. SCH-23390 by itself decreased urine flow and sodium excretion without affecting RBF and blocked the diuretic, natriuretic, and renal vasodilatory effect of Z-1046. We conclude that the renal vasodilatory effect of Z-1046 is D1-like receptor dependent, whereas the diuretic and natriuretic effects are both D1- and D2-like receptor dependent.

Animals↗
PubMed1997

Effects of dopamine and selective dopamine agonists upon platelet accumulation in the cerebral and pulmonary vasculature of the rabbit.

1. A selection of novel compounds were shown to exhibit dopaminergic activity in vitro. 2. 111Indium-labelled platelets were continuously monitored in the cerebral and pulmonary vasculature of anaesthetized rabbits. The effects of dopamine and selective dopamine receptor agonists on ADP and thrombin induced platelet accumulation were recorded. 3. Pretreatment with dopamine (2 mg kg(-1) min(-1), i.v.) significantly reduced ADP (20 microg kg(-1), i.v.) induced platelet accumulation in the pulmonary vasculature whereas lower doses had no effect. 4. Dopamine (100 microg kg(-1) min(-1) intra-carotid, i.c.) potentiated thrombin (90 u kg(-1), i.c.) induced platelet accumulation in the cerebral vasculature whereas higher doses (1-2 mg kg(-1) min[-1]) inhibited accumulation. 5. The selective dopamine receptor agonists tested did not significantly inhibit platelet accumulation induced by ADP or thrombin. Two of these selective agonists, at doses higher than the intended therapeutic doses, induced thrombocytopaenia and an associated increase in platelet accumulation in the lung in response to thrombin. 6. These results extend previous in vitro studies regarding the dual actions of dopamine upon platelets and show for the first time the effects of selective dopamine receptor agonists upon platelet aggregation in vivo.

2-Naphthylamine↗
PubMed1996

The effect of selective phosphodiesterase 3 and 4 isoenzyme inhibitors and established anti-asthma drugs on inflammatory cell activation.

1. This study aimed to evaluate the effects of phosphodiesterase (PDE) inhibitors and currently prescribed anti-asthma drugs for their ability to inhibit inflammatory cell activation in vitro. 2. Alveolar macrophages and eosinophils were isolated from the bronchoalveolar lavage (BAL) fluid of ovalbumin (Ovalb)-sensitized guinea-pigs. Opsonized zymosan (OZ) and PAF stimulated leukotriene B4 (LTB4) release from eosinophils was measured by radioimmunoassay. Ovalb-induced superoxide generation was measured by reduction of cytochrome C. 3. Monocytes were separated from human peripheral venous blood and mast cells were dispersed from human lung fragments. Lipopolysaccharide (LPS)-induced tumour necrosis factor-alpha (TNF-alpha) release from monocytes was measured by ELISA and anti-IgE stimulated histamine release from mast cells was measured by a radioenzymatic method. 4. The beta 2 agonist, salbutamol inhibited TNF-alpha release from monocytes and histamine release from mast cells whilst having no effect on eosinophil-derived LTB4 release or macrophage superoxide generation. 5. The PDE 3 inhibitor, milrinone produced a concentration-related inhibition of TNF-alpha release from monocytes which achieved statistical significance at 10(-5) M but inhibited LTB4 release from eosinophils and superoxide generation from macrophages only at the highest concentration (10(-3) M) examined. Milrinone had no effect on histamine release from mast cells. 6. The selective PDE 4 inhibitors, denbufylline and rolipram and the corticosteroid, beclomethasone produced a concentration-related inhibition of LTB4 release from eosinophils, TNF-alpha release from monocytes and superoxide generation from alveolar macrophages whilst having no effect on histamine release from mast cells. 7. The mixed PDE 3/4 inhibitor, benzafentrine produced a concentration-related inhibition of LTB4 release from eosinophils, TNF-alpha release from monocytes, superoxide generation from alveolar macrophages and histamine release from mast cells. 8. In conclusion these data clearly show that both established anti-asthma medication as well as PDE inhibitors have the potential to inhibit inflammatory cell activation in vitro but that the anti-secretory actions of beta 2 agonists, corticosteroids and PDE inhibitors are distinct.

Animals↗
PubMed1996

Z1046: biochemical characterization of its dopaminergic activity.

Affinity of Z1046 for dopamine receptor subtypes, its ability to modulate D1- and D5-mediated AC stimulation and D1-induced cAMP accumulation were evaluated. On D1-like receptors Z1046 and fenoldopam (fen) showed a similar high affinity, being more potent than DP-5,6-ADTN and 5,6-ADTN. For the D2-like receptors, the affinity rank orders were: D2: Z1046 > or = DP-5,6-ADTN > fen = 5,6-ADTN; D3: Z1046 > DP-5,6-ADTN > fen = 5,6-ADTN; D4: Z1046 = DP-5,6-ADTN > fen = 5,6-ADTN. In AC studies the rank order was: Z1046 = fen > DP-5,6-ADTN > 5,6-ADTN. Z1046 was more efficient than fen in stimulating cAMP accumulation. These results make Z1046 an innovative agent combining D1-like and D2-like activities.

Animals↗
PubMed1996

Z1046: a new specific peripheral dopaminergic compound.

It is well established that peripheral dopamine receptors activation evokes vasodilation and neurohormonal modulation. Z1046 is a potent mixed dopaminergic agonist and is highly selective over adrenergic and serotoninergic (5-HT2) activities. In contrast, dopamine had agonist activities on all adrenergic receptors while it is known that dopexamine has a beta 2 agonist activity and is an inhibitor of the neuronal uptake. As far as fenoldopam is concerned, selective stimulation of D1-like receptors leads to an increase of renin release. In conclusion, Z1046 is a potent and specific drug for dopamine receptors. This profile makes Z1046 different from other dopaminergic agents.

Animals↗
PubMed1995

The effect of selective phosphodiesterase inhibitors in comparison with other anti-asthma drugs on allergen-induced eosinophilia in guinea-pig airways.

The effects of isoenzyme selective phosphodiesterase (PDE) inhibitors and other anti-asthma drugs on antigen-induced eosinophil recruitment and activation in guinea-pig airways was studied. Guinea-pigs were sensitized and subsequently challenged with aerosolized ovalbumin (OVA). Bronchoalveolar lavage (BAL) was performed 24 h later. A significant increase in eosinophils and eosinophil peroxidase (EPO) was detected in BAL fluid and BAL fluid supernatant respectively from OVA immunized guinea-pigs compared with sham treated animals. Guinea-pigs were treated for 7 days prior to antigen challenge with either the following drugs or the appropriate vehicle (i.p.). The selective beta 2 agonist, salbutamol (0.3 mg/kg), the PDE III inhibitor, milrinone (15 mg/kg) and the non-selective PDE inhibitor, trequinsin (1 mg/kg) had no effect on eosinophil number or EPO levels. The PDE IV inhibitor, rolipram (15 mg/kg), the mixed type III/IV PDE inhibitor, benzafentrine (15 mg/kg) and the non-selective PDE inhibitor, aminophylline (31.5 mg/kg) had no effect on eosinophil number but reduced the amount of EPO detected. The anti-inflammatory glucocorticosteroids, beclomethasone (10 mg/kg) and betamethasone (4 mg/kg) and the type IV PDE inhibitor, RP 73401 (5 mg/kg) reduced both eosinophil numbers and EPO levels. These results suggest a role for the type IV PDE isoenzyme in the control of eosinophil recruitment and possibly activation in the airways.

Adrenal Cortex Hormones↗
PubMed1995

Characterization of big endothelin-1-induced contraction in rabbit saphenous artery.

We have characterized the endothelin-converting enzyme (ECE)-like activity involved in big endothelin (ET)-1-induced contraction in rabbit saphenous artery (RSA). Big ET-1 30 nM caused a contraction that was independent of the vascular endothelium. Phosphoramidon and the neutral endopeptidase (NEP) inhibitors thiorphan and candoxatrilat blocked the vasoconstriction caused by big ET-1 in endothelium-denuded RSA. Candoxatrilat (IC50 17 nM) and thiorphan (IC50 2.5 nM), were 5- to 30-fold more potent than phosphoramidon (IC50 83 nM). Other protease inhibitors were inactive. In cultured endothelial cells the ET-1 release was inhibited only by phosphoramidon (IC50 16 microM) but at a concentration 200-fold that required an endothelium-denuded RSA. In conclusion, we can speculate that the big ET-1 contraction in RSA is mediated by an ECE, probably present on smooth muscle cells, which is susceptible to NEP inhibitors and is different from the ECE on endothelial cells.

Animals↗
PubMed1990

Peripheral vascular and neuronal effects of dopamine receptor agonists. A comparison with receptor binding studies in rat striatum.

A series of dopamine (DA)-receptor agonists was tested in vitro on vascular DA1- and neuronal DA2-receptors and the activity observed was compared to their ability to compete with [3H]-SCH23390 and [3H]-domperidone binding to rat striatal membranes. In rabbit splenic artery, where the presence of the DA1-receptor is established, DA and related agonists produced a complete concentration-dependent relaxation of the thromboxane A2-mimetic U46619-induced tone in IBMX (3-isobutyl-1-methylxanthine) treated preparations. The DA vasorelaxant effect proved to be mediated by DA1-receptors, being inhibited by the selective DA1-receptor antagonist SCH23390. Fenoldopam proved to be the most potent agonist in the rabbit splenic artery consistent with the result obtained in the D1-receptor binding assay. Epinine was about 5 times more potent than DA and only 3 times less active than fenoldopam on DA1-receptors although the D1-receptor binding study did not reveal major differences from DA. An opposite profile was observed with N,N-di-n-propyl dopamine (DPDA) showing a functional potency lower than that expected from the binding assay. In cat right atrium, DA and related agonists caused concentration-dependent inhibition of the tachycardia induced by electrical stimulation. The DA effects proved to be mediated by presynaptic DA2-receptor activation, being inhibited by the selective DA2-receptor antagonist domperidone. The DA2-receptor agonist 6-(di-n-propylamino)-5,6,7,8-tetrahydro-1,2-naphthalenediol (DP-5,6-ADTN) was the most potent compound both in the cat atrium and in the binding assay. Epinine was 2 times more potent than DA on DA2-receptors but it showed no differences in the D2-receptor binding assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Lacidipine: a calcium antagonist with potent and long-lasting antihypertensive effects in animal studies.

Lacidipine, currently being evaluated as a once-daily antihypertensive agent, acted as a calcium entry blocker on rabbit ear artery (pA2 = 9.4) with a markedly slower onset of action than that of nitrendipine; this effect was not reversed after 9 h of drug washout. Calcium entry blocker activity was also evaluated on nonvascular smooth muscles: Lacidipine showed a more pronounced vascular selectivity than nitrendipine; for both drugs, concentrations required to induce negative inotropic effects in guinea pig ventricular strip were approximately 100 times higher than concentrations needed to antagonize calcium contraction in vascular smooth muscle. In spontaneously hypertensive rats (SHR), by the tail-cuff method, lacidipine (ED25 = 0.35 mg/kg orally, p.o.) proved approximately 30 times more potent, slower in onset, and longer-acting than nitrendipine in reducing blood pressure. These features were confirmed in chronically implanted SHR after oral and intravenous (i.v.) administration (ED25 = 0.19 mg/kg p.o. and 0.006 mg/kg i.v.). A short-lasting tachycardia was detected with both drugs. No evidence of acquired tolerance emerged after repeated oral administrations over a 3-week period. Lacidipine induced a natriuretic effect in saline-loaded SHR at antihypertensive doses. In renal hypertensive dogs, lacidipine proved more potent (three to seven times), slower in onset, and longer-lasting than nitrendipine after p.o. (ED25 = 0.22 mg/kg) and i.v. (ED25 = 0.004 mg/kg) administrations.

Animals↗