cDNA clones of myeloperoxidase (MPO) and eosinophil peroxidase (EPO) from human blood mononuclear cells differentiated into granulocyte precursors in liquid cultures.
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Cloning, Molecular↗
Biomedical subjects
M Romano
Publications and source records attributed to M Romano.
Lipoxin generation by permeabilized human platelets.
Human platelets convert leukocyte-derived leukotriene (LT) A4 to lipoxins during transcellular lipoxin biosynthesis. Here, we examined lipoxin generation in intact human platelets and compared it with that elicited from permeabilized platelets. Conversion of LTA4 to lipoxins by permeabilized cells exceeded (10-15 times) that to peptidoleukotrienes, while intact cells exposed to thrombin generated similar amounts of these two series (LT/LX). Permeabilized platelets also generated 3-5 times more lipoxins than intact cells. Lipoxin A4 (LXA4), lipoxin B4 (LXB4), and their respective all-trans isomers were identified by physical methods including HPLC and GC-MS. Chiral analysis of platelet-derived all-trans-containing LXs revealed that greater than 69.5 +/- 0.5% carried alcohol groups in the R configuration at carbons 6 and 14 (e.g., 11-trans-LXA4 and 8-trans-LXB4), respectively. More than 50% of these all-trans LX were formed by isomerization of native LXA4 and LXB4 during isolation. Lipoxin formation with permeabilized platelets gave an apparent Km of 8.9 microM and Vmax of 83.3 ng/(min-10(9) platelets) with maximal conversion in pH range 7-9. In addition, permeabilized platelets converted 14,15-LTA4 and LTA5, but not LTA3, to lipoxins. Consecutive exposure to LTA4 did not alter LXA4 generation but inhibited LXB4 by 40-50%, suggesting that LXB4 formation can be regulated by suicide inactivation. Unlike platelets, human endothelial cells did not convert LTA4 to lipoxins. These results indicate that lipoxin formation is a major route of LTA4 metabolism in thrombin-activated platelets and those that have undergone a loss of membrane barriers.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Platelets↗
Lipoxin generation by human megakaryocyte-induced 12-lipoxygenase.
Eicosanoid biosynthesis was examined with a human megakaryocytic cell line (Dami). Megakaryocytes incubated with [1-14C]arachidonic acid and either ionophore A23187 or thrombin generated both thromboxane and 12-hydroxyheptadecatrienoic acid (HHTrE). Exposure to phorbol myristate acetate (PMA) for 1 through 9 days induced differentiation and revealed an increase in the conversion of [1-14C]arachidonate to cyclooxygenase- and lipoxygenase (LO)-derived products. The LO-derived product was identified as 12S-HETE by its physical characteristics including GC/MS and chiral column SP-HPLC. PMA-treated Dami cells did not generate 5-HETE, leukotrienes or lipoxins from exogenous arachidonic acid while they did convert leukotriene A4 (LTA4) to lipoxin A4, lipoxin B4 and their respective all-trans isomers. In addition, COS-M6 cells transfected with a human 12-lipoxygenase cDNA and incubated with either arachidonic acid or LTA4 generated 12-HETE and lipoxins, respectively. The lipoxin profile generated by transfected COS-M6 cells incubated with LTA4 was similar to that generated by the PMA-treated Dami cells. Results indicate that human megakaryocytes can transform arachidonate and LTA4 to bioactive eicosanoids and that the 12-lipoxygenase appears upon further differentiation of these cells. In addition, they indicate that the 12-LO of human megakaryocytes and the 12-LO expressed by transfected COS cells can generate both lipoxins A4 and B4. Together they suggest that the human 12-LO can serve as a model of LX-synthetase activity with LTA4.
Arachidonate 12-Lipoxygenase↗
Influence of atenolol on the relationship between heart rate and QT interval in patients with exercise-induced myocardial ischemia.
The aim of this study was to analyze the relationship between heart rate and QT interval (HR-QT) during exercise in control subjects (Group A) and in patients with coronary artery disease (CAD) with effort angina and without previous myocardial infarction (MI) (Group B). The diagnosis of CAD was confirmed by coronarographic examination. The correlation HR-QT was significant (p < 0.001) in both groups on effort and at recovery. The analysis of the regression HR-QT was carried out separately, both on effort in upright position and at rest in supine position, to avoid the influence of posture on QT length. During effort, the regression line showed lower slope and intercept values in Group B (p < 0.001) than those for Group A. A similar behavior was also observed at rest. Thus, at the highest heart rate, where ECG signs of ischemia (ST depression > 1 mm) frequently occurred, a longer QT interval was present in Group B. Moreover, in Group B, the QT interval in the presence of ECG signs of ischemia was significantly longer (p < 0.01) than in Group A at comparable heart rates both on effort and at rest, thereby confirming the result obtained by comparing both regression lines. The same effort protocol was repeated in Group B patients after acute administration of atenolol 100 mg per os. After atenolol administration, the analysis of the regression HR-QT in Group B clearly showed a shorter QT interval than that obtained in washout period during the baseline test at the highest heart rates where the ECG frequently showed signs of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Oral↗
Beyond cold cardioplegia.
One hundred fifteen consecutive patients were operated on for myocardial revascularization or valvular disease or both with continuous antegrade and retrograde aerobic warm (37 degrees C) blood cardioplegia. Mean cross-clamp time was 56.3 +/- 21 minutes (+/- standard deviation). Mean reperfusion time was 18.4 +/- 11.8 minutes (range, 5 to 81 minutes). Five patients (4.3%) died, and 15 (13%) needed inotropic support. Two (1.7%) required intraaortic balloon support. Two patients (1.7%) had evidence of perioperative myocardial infarction, and 98 (85%) returned spontaneously to normal sinus rhythm. Sixteen patients had a cross-clamp time greater than 80 minutes. All 16 of them had an uneventful postoperative course except for 1 patient who required inotropic drugs. This method of myocardial protection is now used for all open heart procedures in our institution.
Adult↗
Minimal hemodilution and optimal potassium use during normothermic aerobic arrest.
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Cardioplegic Solutions↗
A novel pharmacological approach for paraquat poisoning in rat and A549 cell line using ambroxol, a lung surfactant synthesis inducer.
Paraquat (PQ) is a widely used herbicide that causes acute adult respiratory distress syndrome (ARDS) and chronic lung damage (diffuse fibrosis). One of the earliest biochemical effects induced by PQ is damage to type II pneumocytes with consequent depletion of surfactant. With the aim of counteracting the toxic effects of PQ, a series of investigations were performed into the possible protective effect of the drug ambroxol, which induces the synthesis of surfactant in lung alveolar type II cells. The number of survivors and survival time of rats treated ip with 35 mg PQ/kg was significantly increased by 3 days of ambroxol pretreatment and by ambroxol treatment 30 min or 2 hr after PQ. Total phospholipid content in lung and bronchoalveolar lavage fluid (BALF) was significantly reduced 30 hr after treatment with PQ alone. The association of ambroxol with PQ significantly antagonized this reduction. In BALF the ratio between palmitic acid and stearic acid concentrations was significantly lower in animals treated with PQ alone but was returned to normal by the association with ambroxol. The cell line A549, exposed in vitro to PQ concentrations from 0.5 x 10(-4) to 2 x 10(-3) M, showed a significant dose-dependent loss of viability. Cells pretreated with ambroxol (10 mg/ml) were more resistant to PQ and their viability started to decrease significantly only from a PQ concentration of 0.8 x 10(-3) M. Membrane microviscosity was measured on the same cells. Cells treated with PQ alone showed a reduction of membrane microviscosity, which was significantly counteracted by ambroxol pretreatment. The curves of modification of membrane microviscosity of cells treated with PQ and with ambroxol plus PQ paralleled those of cell viability, indicating that the stimulation of surfactant synthesis in vitro may be a prerequisite for counteracting some of the early effects of PQ.
Adenocarcinoma↗
Cysteamine protects gastric epithelial cell monolayers against drug induced damage: evidence for direct cellular protection by sulphydryl compounds.
The sulphydryl containing drug cysteamine protects gastric mucosa in vivo against acute injury. It is not known whether this protection includes a direct effect on gastric cells. Using gastric epithelial cell monolayers derived from a well differentiated human cell line, we evaluated whether cysteamine protects against taurocholate or indomethacin induced damage in conditions which completely exclude the influence of vascular, hormonal, and neural factors. The effect of cysteamine on prostaglandin production by monolayer cells in vitro was also assessed. Cysteamine decreased damage brought about by sodium taurocholate and indomethacin by 40% (p less than 0.01) and 50% (p less than 0.01) respectively. The sulphydryl blocker iodoacetamide prevented the protective effect of cysteamine. Pretreatment with indomethacin, which inhibited prostaglandin E2 output by 60%, did not prevent protection by cysteamine; incubation with cysteamine decreased prostaglandin E2 production by cultured cells. We conclude that (i) cysteamine directly protected gastric epithelial cells in vitro (ii) this protection occurred with indomethacin, which interferes with cellular metabolism of prostaglandins, and taurocholate, whose damaging action at neutral pH is unrelated to interference with prostanoid metabolism, (iii) cysteamine protection in vitro is unrelated to endogenous prostaglandins and is probably mediated by endogenous sulphydryl compounds.
Cell Line↗
Angiotensin converting enzyme inhibition restores cardiac and hormonal responses to volume overload in patients with dilated cardiomyopathy and mild heart failure.
BACKGROUND: Angiotensin converting enzyme (ACE) inhibition exerts a favorable effect on the response to exercise in heart failure. This study was planned to define the influence of ACE inhibition on the adaptation to volume overload. METHODS AND RESULTS: We studied the hemodynamic, hormonal, and renal responses to acute volume expansion (sodium chloride, 0.9%, 0.25 ml.kg-1.min-1 for 2 hours) in patients with idiopathic or ischemic dilated cardiomyopathy and mild heart failure (New York Heart Association class I or II, ejection fraction < or = 50%). The patients were studied without any pretreatment (n = 14) or after 1 week of treatment with the oral ACE inhibitor quinapril at a dosage of 10 mg/day (n = 11). Seven patients were studied during constant intravenous infusion with nitroglycerin (0.1 micrograms.kg-1.min-1). The study groups had similar hemodynamic and clinical characteristics and hormonal profile at baseline evaluation. In the untreated patients, volume expansion did not increase left ventricular end-diastolic volume measured by echocardiography and was associated with a reduction in ejection fraction (p < 0.05) and with a paradoxical increase in forearm vascular resistance (p < 0.05) estimated by plethysmography. In addition, plasma atrial natriuretic factor did not change, and plasma norepinephrine was increased by saline loading. In contrast, in the patients treated with quinapril, volume expansion induced an increase of both left ventricular volumes (p < 0.001) without changing ejection fraction and reduced forearm vascular resistance (p < 0.05). In addition, in this group, plasma atrial natriuretic factor levels increased (p < 0.05) and plasma norepinephrine did not change during volume overload. During nitroglycerin infusion, volume expansion was associated with peripheral vasodilatation, increases of left ventricular volumes, and no change in ejection fraction. In this group, however, plasma atrial natriuretic factor levels did not change in response to volume overload. CONCLUSIONS: We conclude that pretreatment with the ACE inhibitor quinapril significantly improves compromised responses to acute isotonic volume overload in patients with dilated cardiomyopathy and mild heart failure. The favorable influence of ACE inhibition on cardiovascular and hormonal responses to volume expansion seems to be related to the cardiac unloading produced by this treatment.
Adult↗
Transforming growth factor alpha protection against drug-induced injury to the rat gastric mucosa in vivo.
This study was designed to determine whether transforming growth factor alpha (TGF alpha) protects rat gastric mucosa against ethanol- and aspirin-induced injury. Systemic administration of TGF alpha dose-dependently decreased 100% ethanol-induced gastric mucosal injury; a dose of 50 micrograms/kg delivered intraperitoneally 15 min before ethanol decreased macroscopic mucosal injury by > 90%. At the microscopic level, TGF alpha prevented deep gastric necrotic lesions and reduced disruption of surface epithelium. Pretreatment with orogastric TGF alpha (200 micrograms/kg) only partially (40%) decreased macroscopic ethanol damage. Intraperitoneal administration of TGF alpha at a dose of 10 micrograms/kg, which does not significantly inhibit gastric acid secretion, decreased aspirin-induced macroscopic damage by > 80%. TGF alpha protection does not seem to be mediated by prostaglandin, glutathione, or ornithine decarboxylase-related events, as evidenced by lack of influence of the inhibition of their production. Pretreatment with the sulfhydryl blocking agent N-ethylmaleimide partially abolished (40%) the protective effect of TGF alpha. In addition, systemic administration of TGF alpha resulted in a two-fold increase in tyrosine phosphorylation of phospholipase C-gamma 1 and in a time- and dose-dependent increase in levels of immunoreactive insoluble gastric mucin; these events occurred in a time frame consistent with their participation in the protective effect of TGF alpha.
Animals↗
[Heart surgery in normothermia and aerobiosis: apropos of 530 patients].
Between February and October 1991, 530 consecutive patients underwent myocardial revascularization or valvular surgery with warm continuous antegrade and retrograde cardioplegia (37 degrees C). Three hundred and thirty three patients had isolated myocardial revascularization, 159 valvular surgery alone and 25 had combined valvular and coronary bypass. The global mortality was 5.1%, 3.7% for coronary bypass, 7.5% for valvular surgery and 8% for combined valvular and coronary surgery. A multivariate analysis identified the "reperfusion time" as the only predictive factor of hospital mortality (p < 0.001). Intraortic balloon counterpulsation was required postoperatively in 3.2% of cases, 5.2% of coronary bypass and 0.8% of the valvular patients. Inotropic drugs were used to come off cardiopulmonary bypass in 16.5% of coronary and 37.5% of valvular patients. There were 0.9% perioperative infarctions: 1.2% in the coronary bypass cases and 0.6% in the valvular cases. Spontaneous return to sinus rythm was observed in 87.9% of cases. The average "reperfusion time" was 20.48 +/- 0.7 mn. Analysis of the influence of aortic cross clamp time on cardiac morbidity in two groups of coronary patients (Group I: short cross clamp time less than 60 mn; Group II: long cross clamp time, 60 to 33 mn) showed that the hospital mortality, the prevalence of the use of inotropic drugs and balloon counterpulsation the postoperative cardiac index, the rate of spontaneous de fibrillation and the reperfusion time did not depend on the aortic cross clamp time. Cardiac morbidity.
Adolescent↗
[Current role of reconstructive surgery in the treatment of acute mediastinitis after cardiac surgery].
Infected median sternotomy often requires wide debridement. A large thoracic defect usually results with subsequent exposition of heart, great vessels, aortocoronary bypass grafting, vascular prosthesis. Coverage with muscles transplantation was the standard procedure carried out in this series of 150 cases observed between 1983 and 1991. Details of technique are presented as well as a review of our reconstructive options. Rewarding results were observed even in the most challenging circumstances, suggesting that pursuing this aggressive approach was warranted.
Acute Disease↗
Endotoxic lipid A induces intracellular Ca2+ increase in human platelets.
The activation of protein kinase C by endotoxic lipid A was observed with both intact platelets and in a cell-free system [Romano & Hawiger (1990) J. Biol. Chem. 265, 1765-1770]. We have now studied the action of lipid A on intracellular Ca2+ concentration ([Ca2+]i). Lipid A induced a concentration-dependent rise in [Ca2+]i in human platelets loaded with fura-2, which reached a maximum at 37.1 +/- 3.8 s (tmax). Maximum [Ca2+]i levels, observed at 30 microM lipid A, were 432 +/- 60 nM. EGTA (2 mM) or NiCl2 (1 mM) each decreased the lipid A-dependent elevation of [Ca2+]i by 50-60% without significant modification of tmax, but shortening the time for 50% recovery (t50) from greater than 400 s to 113.1 +/- 29.1 s and 54 +/- 2.1 s, respectively. Quenching of the fura-2 signal was also observed in lipid A-stimulated platelets resuspended with MnCl2 (1 mM), suggesting that both mobilization and external influx of Ca2+ occur. Intracellular Ca2+ mobilization depended on release from Ins(1,4,5)P3-sensitive stores, since Ins(1,4,5)P3 accumulation was detected in lipid A-activated platelets. Staurosporine, an inhibitor of protein kinase C, blocked the [Ca2+]i rise generated by lipid A in platelets [concn. giving 50% inhibition (IC50) = 0.1 microM], prolonging the tmax. to 54.7 +/- 5.1 s, but decreasing the t50 to 157.5 +/- 31.8 s. Staurosporine also suppressed InsP3 accumulation (IC50 = 0.15 microM). These results suggest that platelet activation by lipid A involves an interaction between [Ca2+]i elevation and protein kinase C activation.
Blood Platelets↗
Eosinophil activation on biologic surfaces. Production of O2- in response to physiologic soluble stimuli is differentially modulated by extracellular matrix components and endothelial cells.
Production of O2- in response to FMLP, TNF, IFN-gamma, platelet activating factor, LPS, substance P, and PMA by human eosinophils in suspension and in contact with polystyrene ELISA plastic (PL) or biologic surfaces was studied. Monolayers of human endothelial cells (HEC) or PL coated with FCS, fibronectin, laminin, collagen types I and IV, fibrinogen, or fibrin were used as biologic surfaces. Only PMA and FMLP stimulated O2- generation by eosinophils in suspension. Eosinophils residing on HEC monolayers, either untreated or treated with LPS, were unresponsive to all stimuli except PMA. PMA induced O2- generation by eosinophils on all surfaces; FMLP on all surfaces but HEC monolayers; TNF and platelet-activating factor only on PL, fibrinogen, and fibrin; LPS and substance P only on PL. PMA was equally effective on eosinophils on surfaces and in suspension, whereas the effect of FMLP was greater on eosinophils on surfaces than on eosinophils in suspension. IFN-gamma was ineffective on any of the surfaces tested. These results indicate that biologic surfaces may profoundly affect the ability of eosinophils to respond with a respiratory burst to physiologically relevant soluble stimuli, the effect varying according to the nature of both the stimulus and the surface. Since the respiratory burst generates products of oxygen reduction that are toxic to several tissue components, it follows that biologic surfaces may modulate eosinophil-induced tissue injury.
Endothelium, Vascular↗
The hemoglobins of the cold-adapted Antarctic teleost Cygnodraco mawsoni.
The blood of the teleost Cygnodraco mawsoni, of the endemic Antarctic family Bathydraconidae, contains a major hemoglobin (Hb 1), accompanied by a minor component (Hb 2, about 5% of total). The two hemoglobins have identical alpha chains and differ by the beta chain. The complete amino acid sequence of the three chains has been elucidated, thus establishing the primary structure of both hemoglobins. The sequences show a 53-65% identity with non-Antarctic poikilotherm fish species; on the other hand, a very high degree of similarity (83-88%) has been found between Hb 1 and the major component of another Antarctic species of a different family. The hemoglobin functional properties relative to oxygen binding have been investigated in intact erythrocytes, 'stripped' hemolysate and purified components of C. mawsoni. The hemoglobins display the Bohr and Root effects, indicating fine regulation of oxygen binding by pH and by the physiological effectors organic phosphates.
Adaptation, Physiological↗
Postexercise systolic blood pressure in coronary artery disease.
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Blood Pressure↗
Hepatitis C virus infection is an additive risk factor for development of hepatocellular carcinoma in patients with cirrhosis.
The aim of the present study was to evaluate whether hepatitis C virus plays any role in the development of hepatocellular carcinoma in cirrhotic patients. The role of age, sex, alcohol abuse, and infection by other hepatitic viruses, such as hepatitis B and Delta viruses, was also assessed. We found that mean age and male/female ratio were significantly higher in patients with HCC plus liver cirrhosis than in those with liver cirrhosis alone. Also, the prevalence of HCV infection was found to be higher in HCC patients compared to cirrhotics. Further, by means of multiple logistic regression, we evaluated the independent role of each variable in the development of HCC. Age, male sex, and to a lesser degree, HCV infection, as assessed by anti-HCV positivity, were the only risk factors which significantly correlated with the development of HCC. Moreover, when age and sex were excluded from the statistical model, HCV infection, but not HBV, HDV, and alcohol abuse, appeared to be associated with HCC. In conclusion, based on these data, age and male sex are the most important factors for the development of hepatocellular carcinoma in cirrhotic patients. Hepatitis C virus, at least in the Mediterranean area, may play a role as an additive risk factor of HCC in patients suffering from liver cirrhosis.
Age Factors↗
Effect of tyrosine on the potentiation by aspartame and phenylalanine of metrazol-induced convulsions in rats.
Male rats were treated by oral intubation with tyrosine (Tyr), at doses of 0.5 and 1.0 g/kg body weight, alone or together with 1 g aspartame (APM)/kg body weight, or an equivalent dose of phenylalanine (Phe; 0.5 g/kg body weight); the effects on seizures induced by an effective dose of metrazol (ED50) were observed. Tyr (0.5 g/kg body weight) had a protective effect against the Phe-potentiation of metrazol-induced clonic-tonic convulsions. At the same dose Tyr had no effect on the seizure-promoting activity of APM, but at 1 g/kg it reduced the proconvulsant potential of the sweetener. Analysis of the brain and plasma amino acid concentrations indicated that the Tyr to Phe ratio tended to be enhanced in Tyr-Phe treated rats compared with those treated with Phe alone. This ratio remained essentially constant in the brain of APM-treated rats, compared with those treated with APM plus 1 g Tyr/kg body weight, whereas an increase in this ratio in the plasma was observed. These results confirm that Tyr antagonizes the proconvulsant effect of Phe and APM and they further suggest that no simple relationship exists between the relative brain concentrations of the two amino acids and the response to metrazol convulsions.
Animals↗