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1.
AAPS PharmSciTech ; 21(2): 54, 2020 Jan 06.
Article in English | MEDLINE | ID: mdl-31907712

ABSTRACT

Cervical cancer is associated with the human papilloma virus (HPV) and nowadays is the fourth most frequent cancer among women. One of the treatments for this disease is based on the application of imiquimod. In this study, we postulated that the use of imiquimod in nanoemulsion results in a better antitumoral effect than the drug administered in its nonencapsulated form for the treatment of cervical cancer. Permeability studies using vaginal mucosa, as membrane, and in vitro studies involving cervical cancer cells (viability, clonogenic assay, and cell death analysis) were performed. We showed that low amount of encapsulated imiquimod permeated the vaginal mucosa. However, a higher percentage of cells died after the treatment with low amount (3.0 µmol L-1) of the formulation compared to the free drug. In addition, the innovative formulation presented a combinatory mechanism of cell death involving autophagy and apoptosis. Our results demonstrate that the imiquimod-loaded nanoemulsioncan be an alternative product for the treatment of cervical cancer validating the hypothesis.


Subject(s)
Imiquimod/administration & dosage , Papillomaviridae/drug effects , Uterine Cervical Neoplasms/drug therapy , Animals , Cell Line, Tumor , Drug Compounding , Emulsions , Female , Humans , Nanoparticles , Swine , Uterine Cervical Neoplasms/virology
2.
Trials ; 21(1): 192, 2020 Feb 17.
Article in English | MEDLINE | ID: mdl-32066489

ABSTRACT

BACKGROUND: Ticagrelor is a reversibly binding, direct-acting, oral, P2Y12 antagonist used for the prevention of atherothrombotic events in patients with coronary artery disease (CAD). Ticagrelor blocks adenosine reuptake through the inhibition of equilibrative nucleoside transporter 1 (ENT-1) on erythrocytes and platelets, thereby facilitating adenosine-induced physiological responses such as an increase in coronary blood flow velocity. Meanwhile, adenosine plays an important role in triggering ischemic preconditioning through the activation of the A1 receptor. Therefore, an increase in ticagrelor-enhanced adenosine bioavailability may confer beneficial effects through mechanisms related to preconditioning activation and improvement of coronary microvascular dysfunction. METHODS: To determine whether ticagrelor can trigger ischemic preconditioning and influence microvascular function, we designed this prospective, open-label, pilot study that enrolled patients with stable multivessel CAD requiring staged, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI). Participants will be randomized in 1:1 ratios either to ticagrelor (loading dose (LD) 180 mg, maintenance dose (MD) 90 mg bid) or to clopidogrel (LD 600 mg, MD 75 mg) from 3 to 1 days before the scheduled PCI. The PCI operators will be blinded to the randomization arm. The primary endpoint is the delta (difference) between ST segment elevations (in millimeters, mm) as assessed by intracoronary electrocardiogram (ECG) during the two-step sequential coronary balloon inflation in the culprit vessel. Secondary endpoints are 1) changes in coronary flow reserve (CFR), index of microvascular resistance (IMR), and FFR measured in the culprit vessel and reference vessel at the end of PCI, and 2) angina score during inflations. This study started in 2018 with the aim of enrolling 100 patients. Based on the rate of negative FFR up to 30% and a drop-out rate up to 10%, we expect to detect an absolute difference of 4 mm among the study arms in the mean change of ST elevation following repeated balloon inflations. All study procedures were reviewed and approved by the Ethical Committee of the Catholic University of Sacred Heart. DISCUSSION: Ticagrelor might improve ischemia tolerance and microvascular function compared to clopidogrel, and these effects might translate to better long-term clinical outcomes. TRIAL REGISTRATION: EudraCT No. 2016-004746-28. No. NCT02701140.  TRIAL STATUS: Information provided in this manuscript refers to the definitive version (n. 3.0) of the study protocol, dated 31 October 2017, and includes all protocol amendments. Recruitment started on 18 September 2018 and is currently ongoing. The enrollment is expected to be completed by the end of 2019. TRIAL SPONSOR: Fondazione Policlinico Universitario A. Gemelli - Roma, Polo di Scienze Cardiovascolari e Toraciche, Largo Agostino Gemelli 8, 00168 Rome, Italy.


Subject(s)
Coronary Artery Disease/surgery , Ischemic Preconditioning, Myocardial/methods , Myocardial Reperfusion Injury/prevention & control , Percutaneous Coronary Intervention/adverse effects , Ticagrelor/administration & dosage , Adolescent , Adult , Aged , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Clopidogrel/administration & dosage , Coronary Vessels/drug effects , Female , Fractional Flow Reserve, Myocardial/drug effects , Humans , Male , Microvessels/drug effects , Middle Aged , Myocardial Reperfusion Injury/etiology , Pilot Projects , Preoperative Care/methods , Purinergic P2Y Receptor Antagonists/administration & dosage , Randomized Controlled Trials as Topic , Treatment Outcome , Vascular Resistance/drug effects , Young Adult
3.
Eur J Pharm Biopharm ; 136: 9-17, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30630060

ABSTRACT

This paper proposes the development of imiquimod-loaded polymeric nanocapsules formulation for the treatment of cervical cancer. The mechanism of death involved in the reduction of the cell viability as well as the production of an inflammation marker (IL-6) after the treatment in cell line SiHa have been evaluated. The formulation has significantly decreased the viability of the cells in a time-dependent manner, after 24, 48 and 72 h. Additionally, results showed a cellular decrease of almost 80% of the cells after 72 h of treatment. The formulation induced death by apoptosis, necrosis, autophagy, and increased the percentage of SubG1subpopulation of SiHa cells after 72 h. After the same time-interval, the formulation significantly prevented the appearance of colonies, showing effectiveness against SiHa. Finally, the formulation stimulated SiHa cells to release IL-6. These findings open new possibilities for the development of aqueous nanosuspension containing imiquimod as a novel strategy for the treatment of cervical cancer.


Subject(s)
Antineoplastic Agents/administration & dosage , Cytotoxins/administration & dosage , Drug Carriers/administration & dosage , Imiquimod/administration & dosage , Nanocapsules/administration & dosage , Uterine Cervical Neoplasms , Antineoplastic Agents/metabolism , Apoptosis/drug effects , Apoptosis/physiology , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/physiology , Cytotoxins/metabolism , Drug Carriers/metabolism , Female , Humans , Imiquimod/metabolism , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/metabolism
4.
Biochim Biophys Acta ; 1770(8): 1259-65, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17574764

ABSTRACT

In this study, we evaluated the NTPDases and ecto-5'-nucleotidase (CD73) expression profiles and the pattern of adenine nucleotide hydrolysis in rats submitted to the Walker 256 tumor model, 6, 10 and 15 days after the subcutaneous inoculation. Using RT-PCR analysis, we identified mRNA for all of the members of the ecto-nucleoside triphosphate diphosphohydrolase family investigated and a 5'-nucleotidase. By quantitative real-time PCR, Entpd1 (Cd39) and Entpd2 (Cd39L1) and CD73 were identified as the dominant genes expressed by the Walker 256 tumor, at all times studied. Extracellular adenine nucleotide hydrolysis by the Walker 256 tumor was estimated by HPLC analysis. Rapid hydrolysis of extracellular ATP by the tumor cells was observed, leading to the formation of adenosine and inosine in cells obtained from solid tumors at 6 and 10 days after inoculation. Cells obtained from solid tumors at 15 days of growth presented high levels of AMP and presented adenosine as a final product after 90 min of incubation. Results demonstrate that the presence of NTPDases and 5'-nucleotidase enzymes in Walker 256 tumor cells may be important for regulation of the extracellular adenine nucleotides/adenine nucleoside ratio, therefore leading to tumor growth.


Subject(s)
5'-Nucleotidase/metabolism , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/metabolism , Antigens, CD/metabolism , Apyrase/metabolism , Carcinoma 256, Walker/enzymology , Animals , Cell Line, Tumor , Male , Rats , Rats, Wistar
5.
Monaldi Arch Chest Dis ; 68(4): 235-8, 2007 Dec.
Article in Italian | MEDLINE | ID: mdl-18361223

ABSTRACT

We describe a case of a 56 year-old man with a history of chest pain. No evidence of myocardial ischemia or arrhytmias was observed. Echocardiographic examination in Emergency Department evidenced aortic root dilatation. Angio CT excluded aortic dissection. Trans esophageous Echocardiography (TEE) correctly identified an arterial fistula between the right coronary artery and superior vena cava, confirmed by angio CT 3-D reconstruction and coronarography. The definitive diagnosis was made after integrated approach (using TTE, TEE, CT, coronarography). The anatomic features of the fistula and the aortic root were examinated. Actually the patient is being followed with serial clinical and echocardiography examination for monitoring hemodynamic overload by fistula and size of aortic root for potential surgical correction. Current literature for incidence, diagnosis and the treatment of coronary fistulas is discussed.


Subject(s)
Coronary Vessel Anomalies , Chest Pain/etiology , Coronary Angiography , Coronary Vessel Anomalies/diagnosis , Coronary Vessel Anomalies/diagnostic imaging , Coronary Vessel Anomalies/surgery , Coronary Vessel Anomalies/therapy , Echocardiography, Transesophageal , Electrocardiography , Electrocardiography, Ambulatory , Follow-Up Studies , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Male , Middle Aged , Time Factors , Tomography, X-Ray Computed
6.
Biomed Pharmacother ; 94: 10-20, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28750355

ABSTRACT

Doxazosin has been evaluated for the treatment of several types of cancer. Here, the antitumor effect of the nanoencapsulated form of doxazosin was evaluated in an in vitro model of breast cancer (MCF7 cell line). Doxazosin-loaded polymeric nanocapsules (DXZ-NC) were produced by interfacial deposition of preformed polymer with homogeneous aspect, spherical shape, mean diameter of about 130nm, positive zeta potential (+5mV), and encapsulation efficiency close to 35%. The Alamar Blue® assay and cell counting were carried out to assess cell viability and cell number, respectively. Mechanism of death was evaluated by Annexin/Propidium Iodide staining, while the long-term response was assessed using the clonogenic assay. Nuclear morphometric analysis was investigated using the NMA technique. A significant decrease in cell viability and clonogenicity was observed after the treatment with DXZ-NC when compared to the non-encapsulated drug. All treatments induced apoptosis as the main mechanism of toxicity. In conclusion, the nanoencapsulation of doxazosin improved its in vitro effects in MCF7 cells, without changing the mechanism of cell death underlying its toxicity. This approach was fundamental to reduce the long-term in vitro ability of the remaining tumor cells to form new colonies after the treatment, potentially reducing the risk of tumor recurrence.


Subject(s)
Breast Neoplasms/pathology , Doxazosin/pharmacology , Nanocapsules/chemistry , Cell Count , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Cell Proliferation/drug effects , Cell Survival/drug effects , Clone Cells , Drug Liberation , Female , Humans , MCF-7 Cells , Nanocapsules/ultrastructure , Particle Size
7.
Monaldi Arch Chest Dis ; 66(4): 264-9, 2006 Dec.
Article in Italian | MEDLINE | ID: mdl-17312845

ABSTRACT

Cerebral ischemia is among the principal causes of mortality and morbidity in industrialized countries being responsible of 10-12% of all deaths and of an elevated number of permanent disability. The cardio-embolic forms may be responsible of the 30-35% of cerebrovascular acute syndrome, nevertheless in a significant percentage of cases, especially among young people, cerebral ischemic episodes are not induced by these cardio-embolic forms: these cases are defined as cryptogenetic stroke/TIA. In these patients cardiac abnormalities represented by an aneurysm of the interatrial septum (ASA) and by a patent foramen ovale (PFO) have been frequently observed. The purpose of our prospective, study was to evaluate, through transthoracic echocardiography and tissue harmonic imaging (ETT-THI), the prevalence of ASA in the general population (group A) and the prevalence of ASA-FOP in a subgroup of patients with recent episode of cryptogenetic ischemic stroke/TIA (group B). We studied in a prospective manner from January 1 2003 to October 31t 2004 n. 5.631 patients. The presence of ASA was found in 3.2% of patients of group A, while in patients of group B we identified an ASA in 32% and a POF in 42% of the cases. Using a ETT-THI, our study shows in a wide range of a non selected population a prevalence of ASA greater than in previous studies. Such high prevalence in the general population of patients submitted to echocardiography and the higher frequency in subjects with recent cryptogenetic stroke, suggests to search carefully these abnormalities at the level of the interatrial septum using the harmonic imaging method.


Subject(s)
Brain Ischemia/complications , Echocardiography , Heart Aneurysm/diagnostic imaging , Heart Aneurysm/epidemiology , Heart Septal Defects, Atrial/diagnostic imaging , Heart Septal Defects, Atrial/epidemiology , Stroke/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Brain Ischemia/etiology , Child , Female , Heart Aneurysm/complications , Heart Septal Defects, Atrial/complications , Humans , Italy/epidemiology , Male , Middle Aged , Predictive Value of Tests , Prevalence , Prospective Studies , Sensitivity and Specificity , Stroke/diagnosis , Stroke/epidemiology , Stroke/etiology
8.
Circulation ; 103(18): 2236-41, 2001 May 08.
Article in English | MEDLINE | ID: mdl-11342470

ABSTRACT

BACKGROUND: C-reactive protein (CRP) plasma levels have been associated with short- and long-term occurrence of coronary events. We investigated whether circulating inflammatory cell responsiveness to low-grade stimuli could contribute to the reported association between CRP and coronary events. METHODS AND RESULTS: We studied 32 patients with unstable angina who were followed for 24 months and were free of symptoms for 6 months (group 1): 19 patients had persistently high CRP levels (>0.3 mg/dL) (group 1A); 13 patients had normal CRP levels (group 1B). During the follow-up, 12 (63%) group 1A but no group 1B patients developed an infarction or recurrence of unstable angina (P<0.001). Eighteen patients with chronic stable angina (group 2) and 18 healthy subjects (group 3) were studied as controls. Interleukin (IL)-6 production (median, range) by peripheral blood mononuclear cells after 4 hours of in vitro stimulation with 1 ng/mL lipopolysaccharide (LPS) was significantly higher in group 1A (4526 pg/mL, 3042 to 10 583 pg/mL) than in group 1B (1752 pg/mL, 75 to 3981 pg/mL), group 2 (707 pg/mL, 41 to 3275 pg/mL), and group 3 (488 pg/mL, 92 to 3503 pg/mL) (all P<0.001). No significant differences were observed among the other groups. IL-6 production after LPS-challenge was correlated with baseline CRP levels (r=0.42, P=0.005). CONCLUSIONS: Mononuclear cells of patients with recurrent phases of instability exhibit an enhanced production of IL-6 in response to low-dose of LPS, correlated with baseline CRP levels, 6 months after the last acute event. This persisting enhanced acute-phase responsiveness may help explain the association between CRP and acute coronary events.


Subject(s)
Angina, Unstable/diagnosis , Angina, Unstable/immunology , Lipopolysaccharides/pharmacology , Monocytes/drug effects , Monocytes/immunology , Angina, Unstable/metabolism , C-Reactive Protein/metabolism , C-Reactive Protein/pharmacology , Cell Separation , Chronic Disease , Drug Synergism , Female , Follow-Up Studies , Humans , Interleukin-6/biosynthesis , Interleukin-6/blood , Male , Middle Aged , Monocytes/metabolism , Predictive Value of Tests , Prospective Studies , Recurrence
9.
J Am Coll Cardiol ; 31(1): 62-6, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9426019

ABSTRACT

OBJECTIVES: We sought to investigate whether patients with syndrome X have an abnormal perception of cardiac pain. BACKGROUND: Previous studies have reported an increased sensitivity to potentially painful cardiac stimuli in patients with syndrome X. However, it is not clear whether this increase is due to an increased perception of pain or to an enhanced tendency to complain. METHODS: We assessed cardiac sensitivity to pain in 16 patients with syndrome X and 15 control subjects by performing right atrial and ventricular pacing with increasing stimulus intensity (1 to 10 mA) at a rate 5 to 10 beats higher than the patient's heart rate. False and true pacing were performed in random sequence, with both patients and investigators having no knowledge of the type of stimulation being administered. RESULTS: No control subject had pacing-induced pain; conversely, 8 patients with syndrome X reported angina during atrial pacing (50%, p < 0.01) and 15 during ventricular pacing (94%, p < 0.001). During atrial stimulation, both true and false pacing caused chest pain in a similar proportion of patients (50% vs. 63%, p = 0.61), whereas during ventricular stimulation, true pacing caused chest pain in a higher proportion of patients (94% vs. 50%, p < 0.05). Pain threshold and severity of pain (1 to 10 scale) were similar during true and false atrial pacing, whereas true ventricular pacing resulted in a lower pain threshold (mean +/- SD 3.7 +/- 3.0 vs. 7.9 +/- 2.8 mA, p < 0.001) and a higher level of pain severity (7.3 +/- 2.7 vs. 3.1 +/- 3.5, p < 0.001) than did false pacing. CONCLUSIONS: Patients with syndrome X frequently reported chest pain even in the absence of cardiac stimulation. Yet, in addition to this increased tendency to complain, they also exhibited a selective enhancement of ventricular painful sensitivity to electrical stimulation.


Subject(s)
Chest Pain/psychology , Microvascular Angina/psychology , Pain Threshold , Adult , Cardiac Pacing, Artificial , Double-Blind Method , Electric Stimulation , Female , Humans , Male , Middle Aged
10.
J Am Coll Cardiol ; 35(3): 633-9, 2000 Mar 01.
Article in English | MEDLINE | ID: mdl-10716465

ABSTRACT

OBJECTIVES: We sought to investigate whether a brief episode of myocardial ischemia produces a detectable cardiac oxidative stress in patients undergoing elective coronary angioplasty (PTCA). BACKGROUND: Although cardiac oxidative stress has been clearly demonstrated in experimental models of ischemia-reperfusion, its presence in patients after transient myocardial ischemia is still unclear. METHODS: In order to evaluate oxidative stress in ischemic cardiac regions, plasma conjugated dienes (CD), lipid hydroperoxides (ROOHs) and total antioxidant capacity (TRAP), independent indexes of oxidative stress, were measured in the aorta and great cardiac vein (GCV) before (t0), 1, (t1), 5 (t5) and 15 min (t15) after first balloon inflation in 15 patients undergoing PTCA on left anterior descending coronary artery (Group 1); six patients with right coronary artery stenosis (Group 2), which is not drained by the GCV, were studied as controls. RESULTS: In Group 1 at baseline, CD and ROOHs levels were higher in GCV than in aorta (p < 0.01 for both), and TRAP levels were lower (p < 0.01). Aortic levels of CD, ROOHs and TRAP did not change at any time after to; venous levels of CD and ROOHs levels markedly increased at t1, at t5 and remained elevated at t15 (p < 0.01 for all comparisons vs. to); venous levels of TRAP decreased at t1 and t5 (p < 0.01 vs. t0) and returned to normal at t15. In Group 2, CD, ROOHs and TRAP levels were similar in the aorta and GCV and did not change throughout the study. CONCLUSIONS: Short episodes of myocardial ischemia during PTCA induce a sustained oxidative stress, which is detectable in the venous effluent of reperfused myocardium.


Subject(s)
Antioxidants/metabolism , Coronary Circulation , Lipid Peroxidation , Myocardial Ischemia/metabolism , Myocardium/metabolism , Angioplasty, Balloon, Coronary , Aorta, Thoracic/metabolism , Biomarkers/blood , Coronary Vessels/metabolism , Female , Humans , Lipid Peroxides/metabolism , Male , Middle Aged , Myocardial Ischemia/therapy , Myocardial Reperfusion , Oxidative Stress , Oxygen Consumption
11.
J Am Coll Cardiol ; 34(6): 1696-703, 1999 Nov 15.
Article in English | MEDLINE | ID: mdl-10577559

ABSTRACT

OBJECTIVES: We assessed the extent and the time course of the acute phase response following myocardial cell necrosis and its relationship with the presence of preinfarction unstable angina (UA). BACKGROUND: Elevated levels of acute phase proteins have been reported in patients with UA and in patients with acute myocardial infarction (MI). METHODS: C-Reactive Protein (CRP), serum amyloid A protein (SAA) and interleukin-6 (IL-6) were measured in 36 patients with MI admitted within 3 h from symptoms onset. All patients had normal levels of creatine kinase and of troponin T on admission, rising above diagnostic levels within 6 to 12 h. Blood samples for CRP, SAA and IL-6 measurements were taken on admission, at 6, 24, 48, 72 h and at discharge. RESULTS: Twenty of the 36 patients studied presented an unheralded MI (Group 1); the remaining 16 patients had symptoms of unstable angina in the preceding 7 days (Group 2). Group 2 patients have much higher levels of CRP and SAA on admission (median values 8.8 vs. 3 mg/L and 28 vs. 3.4 mg/L, respectively, all p<0.001). Following the necrotic insult, despite similar infarct size and clinical signs of reperfusion, Group 2 patients had strikingly higher peaks of IL-6 (median values 85.2 vs. 19 pg/ml, p<0.05), CRP (50 vs. 31.4 mg/L, p<0.05) and SAA (228 vs. 45 mg/L, p<0.001). CONCLUSIONS: Our data demonstrated that the acute phase response is greatly enhanced in patients with preinfarction UA compared with those presenting with an unheralded MI. The significant differences in acute phase response observed in these two clinical presentations of MI indicate a major difference in their underlying pathogenetic components.


Subject(s)
Acute-Phase Reaction/pathology , Angina, Unstable/pathology , Acute-Phase Reaction/blood , Acute-Phase Reaction/etiology , Aged , Angina, Unstable/blood , C-Reactive Protein/analysis , Creatine Kinase/blood , Female , Humans , Interleukin-6/analysis , Male , Middle Aged , Myocardium/pathology , Necrosis , Serum Amyloid A Protein/analysis , Troponin T/blood
12.
J Am Coll Cardiol ; 34(5): 1512-21, 1999 Nov 01.
Article in English | MEDLINE | ID: mdl-10551701

ABSTRACT

OBJECTIVES: We sought to investigate whether early and late outcome after percutaneous transluminal coronary angioplasty (PTCA) could be predicted by baseline levels of acute-phase reactants. BACKGROUND: Although some risk factors for acute complications and restenosis have been identified, an accurate preprocedural risk stratification of patients undergoing PTCA is still lacking. METHODS: Levels of C-reactive protein (CRP), serum amyloid A protein (SAA) and fibrinogen were measured in 52 stable angina and 69 unstable angina patients undergoing single vessel PTCA. RESULTS: Tertiles of CRP levels (relative risk [RR] = 12.2, p < 0.001), systemic hypertension (RR = 4.3, p = 0.046) and female gender (RR = 4.1, p = 0.033) were the only independent predictors of early adverse events. Intraprocedural and in-hospital complications were observed in 22% of 69 patients with high serum levels (>0.3 mg/dl) of CRP and in none of 52 patients with normal CRP levels (p < 0.001). Tertiles of CRP levels (RR = 6.2, p = 0.001), SAA levels (RR = 6.0, p = 0.011), residual stenosis (RR = 3.2, p = 0.007) and acute gain (RR = 0.3, p = 0.01) were the only independent predictors of clinical restenosis. At one-year follow-up, clinical restenosis developed in 63% of patients with high CRP levels and in 27% of those with normal CRP levels (p < 0.001). CONCLUSIONS: Preprocedural CRP level, an easily measurable marker of acute phase response, is a powerful predictor of both early and late outcome in patients undergoing single vessel PTCA, suggesting that early complications and clinical restenosis are markedly influenced by the preprocedural degree of inflammatory cell activation.


Subject(s)
Angioplasty, Balloon, Coronary/adverse effects , C-Reactive Protein/analysis , Aged , Female , Fibrinogen/analysis , Humans , Male , Middle Aged , Predictive Value of Tests , Prognosis , Recurrence , Risk Assessment , Serum Amyloid A Protein/analysis
13.
Int J Biochem Cell Biol ; 32(1): 105-13, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10661899

ABSTRACT

We have tested several chemical modifiers to investigate which amino acid residues, present in the primary structure of the ecto-apyrase, could be involved in catalysis. Synaptosomes from cerebral cortex of rats were prepared and the ATP diphosphohydrolase activity was assayed in absence or the presence of the modifiers. Percentages of residual activity for ATPase and ADPase obtained when the following reagents were tested, are respectively: phenylglyoxal (an arginine group modifier) 17 and 30%; Woodward's reagent (a carboxylic group modifier) 33 and 23%; Koshland's reagent (a tryptophan group modifier) 10 and 12%; maleic anhidride (an amino group modifier) 11 and 25% and carbodiimide reagent (a carboxylic group modifier) 56 and 72%. Otherwise, PMSF, a seryl protein modifier and DTNB, a SH-group modifier did not affect either ATPase or ADPase activity. Inhibitions observed after treatment with phenylglyoxal and Woodward's reagent were significantly prevented when the synaptosomal fraction was preincubated with ATP and ADP, indicating that the arginine and the side chain of glutamate or aspartate (carboxyl groups) participate in the structure of the active site. This interpretation was confirmed by using GTP and GDP, two other apyrase substrates. Phenylglyoxal and Woodward's reagent also inhibited the GTPase and GDPase activities and this inhibition was prevented by preincubation with these substrates.


Subject(s)
Adenosine Triphosphatases/metabolism , Brain/enzymology , 2-Hydroxy-5-nitrobenzyl Bromide/pharmacology , Adenosine Triphosphatases/antagonists & inhibitors , Animals , Antigens, CD , Apyrase/metabolism , Carbodiimides/pharmacology , Enzyme Inhibitors/pharmacology , Female , Guanosine Diphosphate/metabolism , Guanosine Triphosphate/metabolism , Isoxazoles/pharmacology , Maleic Anhydrides/pharmacology , Phenylglyoxal/pharmacology , Rats , Synaptosomes/enzymology
14.
Am J Cardiol ; 76(4): 215-9, 1995 Aug 01.
Article in English | MEDLINE | ID: mdl-7618611

ABSTRACT

Coronary angiographic findings were compared in patients who presented with acute myocardial infarction (AMI, n = 75), unstable angina pectoris (UAP, n = 36), or stable angina pectoris (SAP, n = 36) for > or = 2 years without evidence of any previous acute event and with an angiogram within 2 years of the initial symptoms. Angiograms were evaluated blindly for severity, extent (depending on the percentage of each coronary segment showing atherosclerosis), and pattern (discrete, < 3 loci of narrowings involving < 50% of any segment; diffuse, anything exceeding this). Patients in the SAP group had more narrowed arteries (2.4 +/- 0.7 vs 1.3 +/- 0.6 [p < 0.02] and 1.4 +/- 0.6 [p < 0.02]), more stenoses (6.0 +/- 3.3 vs 2.1 +/- 1.5 [p < 0.01] and 2.6 +/- 1.7 [p < 0.05]) and occlusions (1.3 +/- 1.1 vs 0.7 +/- 0.6 [p = 0.05] and 0.3 +/- 0.5 [p < 0.02]), and a greater extent index (0.9 +/- 0.5 vs 0.5 +/- 0.3 [p < 0.02] and 0.5 +/- 0.3 [p < 0.02]) than those in the AMI and UAP groups. Furthermore, a discrete pattern was less prevalent in patients with UAP than in those with SAP or AMI (3% vs 40% [p < 0.02] and 25% [p < 0.05], respectively). In conclusion, patients who present with acute coronary syndromes have less extensive atherosclerosis than those who present with chronic stable angina. Therefore, in the former group, coronary atherosclerosis appears to be more susceptible to ischemic stimuli responsible for acute coronary syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Angina Pectoris/diagnostic imaging , Angina, Unstable/diagnostic imaging , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Myocardial Infarction/diagnostic imaging , Angina Pectoris/etiology , Angina, Unstable/etiology , Coronary Artery Disease/complications , Coronary Artery Disease/pathology , Coronary Vessels/pathology , Female , Humans , Male , Middle Aged , Myocardial Infarction/etiology , Risk Factors
15.
Am J Cardiol ; 84(10): 1187-91, 1999 Nov 15.
Article in English | MEDLINE | ID: mdl-10569328

ABSTRACT

Syndrome X may be caused by a coronary microvascular dysfunction, possibly due to abnormalities in coronary endothelial function. Previous studies suggested that endothelin-1 (ET-1) might be involved in the pathogenesis of syndrome X. Baseline arterial and coronary sinus ET-1 levels were measured in 13 patients with syndrome X (10 women, 52+/-7 years) and in 8 control patients (5 women, 46+/-11 years). ET-1 was also measured after atrial pacing in 12 patients with syndrome X and all controls. To simultaneously assess the activity of nitric oxide, guanosine 3'-5'-cyclic monophosphate (cGMP) was also measured in 11 patients with syndrome X and 7 controls. Baseline arterial (2.27+/-0.46 vs. 1.90+/-0.22 pg/ml, p<0.05) and coronary sinus (2.03+/-0.43 vs. 1.68+/-0.28 pg/ml, p = 0.06) ET-1 plasma levels were higher in patients than in controls. After pacing, arterial ET-1 levels did not change in either group and coronary sinus ET-1 levels were also unchanged in controls. In contrast, coronary sinus ET-increased significantly in response to atrial pacing in patients with syndrome X (p = 0.023), and differences between coronary sinus ET-1 levels of patients with syndrome X and controls after pacing became highly significant (2.22+/-0.45 vs. 1.69+/-0.20 pg/ml, respectively, p = 0.006). No significant differences in arterial and coronary sinus cGMP concentrations were found between the 2 groups, both at baseline and after pacing. Our findings suggest that an increased vasoconstrictor activity of microvascular endothelium is present in at least some patients with syndrome X and may be involved in the pathogenesis of the syndrome.


Subject(s)
Cardiac Pacing, Artificial , Endothelin-1/blood , Microvascular Angina/blood , Adult , Cyclic GMP/blood , Endothelium, Vascular/physiopathology , Female , Humans , Male , Microvascular Angina/physiopathology , Microvascular Angina/therapy , Middle Aged
16.
Am J Cardiol ; 80(5A): 10E-16E, 1997 Sep 04.
Article in English | MEDLINE | ID: mdl-9296463

ABSTRACT

In this article, the clinical, angiographic, and postmortem features of unstable angina are reviewed and its pathogenesis is discussed. Coronary plaque inflammation may play a key role in the pathogenesis of unstable angina and the evidence for this assertion is examined. Finally, the therapeutic implications of the involvement of inflammation in acute coronary syndromes are outlined.


Subject(s)
Angina, Unstable/immunology , Angina, Unstable/physiopathology , Animals , Coronary Angiography , Cytokines/physiology , Endothelium, Vascular/physiology , Heart Diseases/physiopathology , Humans , Inflammation/physiopathology , Thrombosis/physiopathology
17.
Chest ; 100(2): 303-6, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1864099

ABSTRACT

Fourteen patients (ten men and four women; mean age, 37 years) with lone atrial fibrillation (AF) (1 to 18 months' duration) were evaluated by thyroid function tests, two-dimensional echocardiography, hemodynamics, coronary angiography, and left ventricular endomyocardial biopsy, because of unresponsiveness to the usual antiarrhythmic therapy. The results of the T3, T4, TSH, and TRH tests were normal in all patients; cardiac valves and ventricular and atrial sizes (left atrium less than 40 mm) were within the normal limits; also normal were LVEDP (less than or equal to 10 mm Hg) and EF (greater than 0.50). Histologic findings were abnormal in all cases, with three patients showing cardiomyopathic changes, three other patients showing active myocarditis (lymphocytic in two and eosinophilic in one), and eight patients with nonspecific necrosis or fibrosis or both. Steroids (prednisone; 50 mg/m2 of body surface area daily) used in addition to antiarrhythmic therapy in patients with eosinophilic and lymphocytic active myocarditis were able to cause reversion to sinus rhythm, while the other patients continued to have AF. This study documents that occult myocardial diseases (myocarditis, cardiomyopathy, and nonspecific necrosis or fibrosis) can underlie "primary" AF. The addition of steroids to antiarrhythmic therapy in patients with refractory AF and histologic evidence of active myocarditis seems to be useful in controlling the arrhythmia.


Subject(s)
Atrial Fibrillation/pathology , Cardiomyopathies/pathology , Myocardium/pathology , Adult , Anti-Arrhythmia Agents/therapeutic use , Atrial Fibrillation/drug therapy , Biopsy , Cardiomyopathies/drug therapy , Cardiomyopathy, Hypertrophic/pathology , Diagnosis, Differential , Endomyocardial Fibrosis/pathology , Female , Humans , Male , Middle Aged , Myocarditis/pathology , Necrosis , Prednisone/therapeutic use , Recurrence
18.
Thromb Res ; 103 Suppl 1: S29-34, 2001 Sep 30.
Article in English | MEDLINE | ID: mdl-11567666

ABSTRACT

Experimental data indicate that urokinase-type plasminogen activator (u-PA) contributes significantly to endogenous fibrinolysis and vascular remodeling in proportion to its local concentrations. In humans, however, it is not known whether u-PA levels vary at different sites and across specific vascular beds. We investigated possible regional and artero-venous differences in plasma u-PA concentrations in 15 patients undergoing cardiac catheterization. Three pairs of simultaneous samples were taken from: (1) the ascending aorta and coronary sinus; (2) left ventricle and right atrium; (3) femoral artery and femoral vein. Single-chain urokinase-type plasminogen activator (scu-PA) was measured by bioimmunoassay, and total u-PA antigen (including scu-Pa and two-chain urokinase-type plasminogen activator complexed with inhibitors (tcu-PA)) by enzyme-linked immunosorbent assay. Scu-PA represented, on average, 51+/-15% of total u-PA concentrations. Scu-PA and total u-PA levels were correlated (r=.72, P<.0001) and did not differ significantly among the arterial or venous locations. There was a small but consistent increase in mean (+/-standard deviation (S.D.)) scu-PA concentrations from all arterial to all venous samples (1.5+/-0.6 vs. 1.6+/-0.5 ng/ml, P=.038) and from ascending aorta to coronary sinus (1.6+/-0.5 vs. 1.7+/-0.6 ng/ml, P=.046). Similarly, total u-PA levels increased from femoral artery to femoral vein (2.9+/-0.7 vs. 3.0+/-0.8 ng/ml, P<.001). In contrast, across the lungs, no significant concentration-gradient was seen in either scu-PA or total u-PA. The changes in total u-PA roughly followed those of scu-PA. These data identify an artero-venous gradient in human plasma u-PA across the coronary and peripheral beds, but not across the lungs, suggesting differences in u-PA kinetics according to vascular location.


Subject(s)
Cardiac Catheterization , Urokinase-Type Plasminogen Activator/blood , Aged , Arteries/enzymology , Blood/metabolism , Blood Circulation/physiology , Endothelium, Vascular/physiology , Female , Humans , Male , Middle Aged , Protein Subunits , Tissue Distribution , Veins/enzymology
19.
Coron Artery Dis ; 6(6): 479-87, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7551269

ABSTRACT

BACKGROUND: Previous studies reported a reduced coronary blood flow reserve, assessed by the intravenous administration of dipyridamole, in patients with angina and normal coronary arteries, and early after successful coronary angioplasty, which suggests the presence of small coronary vessel dysfunction. This study aimed to establish whether the mechanisms of small coronary vessel disease in these two groups of patients are similar. METHODS: The effects of the intracoronary infusion of adenosine and dipyridamole (maximum dose 2.7 and 7.5 mg/min, respectively) on coronary blood flow velocity were assessed in 11 patients with angina and normal coronary arteries (group A) and in 12 patients immediately after successful coronary angioplasty (group B) using a 0.018" Doppler wire. RESULTS: Baseline coronary blood flow velocity was significantly higher in group B than group A (34 +/- 14 versus 19 +/- 8 cm/s; P = 0.001). In group A, coronary blood flow velocity was higher during adenosine than dipyridamole infusion (74 +/- 17 versus 58 +/- 21 cm/s; P < 0.001), whereas in group B velocities were similar (85 +/- 30 versus 78 +/- 32 cm/s; NS). CONCLUSIONS: In patients with angina and normal coronary arteries, a maximal dose of adenosine causes a greater coronary dilation than that of dipyridamole. Given that dipyridamole operates mainly through an inhibition of adenosine re-uptake, it can only dilate the arteriolar segments exposed to endogenous adenosine. Therefore, the lower response to dipyridamole than to exogenous adenosine observed in patients with angina and normal coronary arteries suggests an impairment of the pre-arterioles that are not influenced by endogenous adenosine, resulting in a limited flow-mediated dilation in response to arteriolar dilation. Such an impairment is not apparent immediately after successful coronary angioplasty, where the most obvious abnormality is an increase of baseline coronary blood flow velocity.


Subject(s)
Angina Pectoris/physiopathology , Coronary Circulation/drug effects , Dipyridamole/pharmacology , Vasodilation/drug effects , Vasodilator Agents/pharmacology , Adenosine/pharmacology , Angina Pectoris/drug therapy , Angina Pectoris/surgery , Angioplasty, Balloon, Coronary , Blood Flow Velocity/drug effects , Dipyridamole/therapeutic use , Female , Humans , Male , Middle Aged , Regional Blood Flow/drug effects , Vasodilator Agents/therapeutic use
20.
Ital Heart J ; 1(1): 68-72, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10868927

ABSTRACT

BACKGROUND: Oxidative stress plays a key role in ischemia-reperfusion injury, causing peroxidation of tissue lipids and proteins. However, it is debated whether brief ischemic episodes are sufficient to cause detectable oxidative stress in humans, since biochemical markers used so far in the setting of percutaneous transluminal coronary angioplasty (PTCA) gave conflicting results. METHODS: We determined lipid hydroperoxides (ROOHs), conjugated dienes (CD) and total radical-trapping antioxidant capacity (TRAP), three different independent markers of oxidative stress, in aortic and great cardiac vein blood of 5 patients undergoing PTCA before a single balloon inflation lasting 115 +/- 38 s (t0), and 1 min (t1), 5 min (t5), 15 min (t15) after balloon deflation (Group 1). ROOHs and CD were also determined in aortic and great cardiac vein blood of 5 patients with mitral valve disease (Group 2). RESULTS: In Group 1, great cardiac vein levels of ROOHs and CD at t1 increased by 219% and 79%, respectively, compared to t0 (p < 0.01); this sharp and consistent increase persisted up to t15 (+189% and +63%, respectively, compared to t0; p < 0.01). Great cardiac vein levels of TRAP were significantly lower than aortic levels at t0, and exhibited a further decrease at tl. No significant differences in aortic and great cardiac vein levels of ROOHs and CD at t0 were observed between Group 1 and Group 2. CONCLUSIONS: The three methods we used showed a remarkable sensitivity for the detection of post-ischemic reperfusion injury in cardiac venous blood and may be useful for detecting small foci of ischemia-reperfusion injury in microvascular angina.


Subject(s)
Myocardial Reperfusion Injury/blood , Oxidative Stress , Angioplasty, Balloon, Coronary , Antioxidants/analysis , Coronary Disease/therapy , Feasibility Studies , Humans , Lipid Peroxidation , Oxidative Stress/physiology , Sensitivity and Specificity
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