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F Pompeo

Publications and source records attributed to F Pompeo.

At least 19 recordsLinked to original sources
PubMed2006

Management and outcomes of hepatic cirrhosis: Findings from the RING study.

BACKGROUND/AIM: Hepatic cirrhosis is a frequent reason for ordinary hospital admission (OA). The RING study collected hospital discharge files (HDF) from Italian hospital gastroenterology units (IGU). This caselist provides a broad picture of the patients admitted for this pathology. MATERIAL/METHODS: More than 50,000 HDF for OA were collected between 2001 and 2004 from 26 IGU. RESULTS: Eight thousand four hundred and eighty-seven HDF (16%) had a diagnosis of hepatic cirrhosis; Child-Pugh classes were 20.2% A, 34.8% B and 45.0% C. Patients' mean age was 63.7+/-12.1 years and 62.5% were male. A 61.1% of the cirrhosis cases had ascites, 29.9% portal-systemic encephalopathy, 29.2% hepatocellular carcinoma (HCC), 10% bleeding varices, 3.0% hepatorenal syndrome (HRS). Mortality for OA for cirrhosis was 5.7% versus 2.6% for other diagnoses. The proportion varied with the severity of the cirrhosis: 0% for Child A, 1.1% B, 10.5% C. Mortality was significantly associated with: Child-Pugh at admission (odds ratio: OR 9.2), HRS (OR 11.7), bleeding varices (OR 2.2), HCC (OR 1.8). CONCLUSIONS: Hepatic cirrhosis was found in 16% of the OA to IGU and mortality was double the rate for all the other pathologies in the same wards. Child-Pugh is a useful prognostic tool, higher classes implying a greater risk of death. HRS and bleeding varices were the complications with most influence on in-hospital mortality.

Journal Article↗
PubMed2005

Seasonal patterns of hospital treatment for inflammatory bowel disease in Italy.

AIM: It is still debated whether clinical flare-ups of chronic inflammatory bowel disease follow a seasonal pattern, and the various reports are based on general practitioners' records or hospital discharge charts. There are, however, no specific figures for treatment in hospital gastroenterology units, which serve as a reference point for these disorders. This study was therefore designed to investigate whether there is a seasonal pattern in admissions for inflammatory intestinal disease in Italy, differing from what is generally known about gastrointestinal pathologies, since there are no nation-wide figures on the subject. METHODS: The RING (Ricerca Informatizzata in Gastroenterologia) project is an observational study collecting hospital discharge forms from 22 centers in Italy. RESULTS: From winter 2000 to autumn 2003, the 22 gastroenterology units participating in the RING project discharged 32,357 patients following ordinary hospital admissions. Of these, 2,856 (8.8%) had a main diagnosis of inflammatory bowel disease: 1,541 Crohn's disease, and 1,315 ulcerative colitis. No seasonal patterns were detected for either category, or when the analysis was done by age, sex and site of disease. CONCLUSIONS: The most serious flare-ups of inflammatory bowel disease, i.e. those requiring routine hospital treatment, do not appear to follow any seasonal pattern, regardless of the site of the disease or the patient's age or sex.

Adult↗
PubMed2005

Biochemical interaction between effects of beclomethasone dipropionate and salbutamol or formoterol in sputum cells from mild to moderate asthmatics.

BACKGROUND: Several in vitro studies demonstrate that corticosteroids and long-acting beta(2) agonists may have a complementary and synergistic mode of action on the inflammatory processes in asthma. METHODS: Sputum was induced in 20 mild to moderate asthmatic patients and the induced sputum cells (ISC) were cultured with beclomethasone dipropionate (BDP) 10(-7) M, salbutamol 10(-8) M and formoterol 10(-8) M either alone or in combination, BDP plus salbutamol and BDP plus formoterol, for 24 h. We measured the levels of growth macrophages-colony stimulating factor (GM-CSF), released on activation normal T cells expressed and activated (RANTES) and interleukin-8 (IL-8), in the supernatant of stimulated cells by ELISA. Furthermore, we assessed nuclear translocation of glucocorticoid receptor (GR) and the expression of beta(2) receptor in ISC by immunofluorescence and RT-PCR, respectively. RESULTS: The release of GM-CSF, RANTES and IL-8 in ISC was significantly reduced by BDP plus salbutamol or formoterol as compared with either drug alone (P < 0.0001). beta(2) receptor expression was increased after 30 min of incubation with BDP and continued to increase over a time period of 4 h (P < 0.0001). Furthermore after 30 min of incubation, nuclear translocation of GR was greater with BDP plus salbutamol or formoterol than with any of the drugs alone (P < 0.0001). CONCLUSION: The present ex vivo study demonstrates a complementary mode of action between BDP and salbutamol or formoterol leading to an enhanced anti-inflammatory activity.

Adult↗
PubMed2001

A common variant of endothelial nitric oxide synthase (Glu298Asp) is an independent risk factor for carotid atherosclerosis.

BACKGROUND AND PURPOSE: Endothelium-derived NO is formed from L-arginine by endothelial NO synthase (eNOS) encoded by the NOS 3 gene on chromosome 7. Because several studies have indicated that NO plays a key role in the development of the atherosclerotic process, we investigated whether common variants in the eNOS gene are associated with an increased risk of plaque on carotid arteries. METHODS: We studied 375 subjects attending the hypertension center of our institution to be screened for arterial hypertension. The examined subjects were classified according to the presence of carotid plaques (intima-media thickness >/=1.5 mm), and 2 intronic (CA and 27-bp repeats) polymorphisms and 1 exonic (Glu298Asp) polymorphism of the eNOS gene were explored. RESULTS: Only the Glu298Asp polymorphism of eNOS was associated with the presence of carotid plaques (P:<0.05). In particular, there was an excess of homozygotes for the Asp298 variant among subjects with carotid plaques, whereas the number of subjects who had the Glu298 allele in exon 7 of the eNOS gene was equally distributed in both study groups. Interestingly, the risk of having carotid plaques was increased approximately 3 times in subjects who were homozygotic for the Asp298 variant compared with subjects who were homozygotic for the Glu298 variant and was independent of the other common risk factors (age, blood pressure, and smoking). CONCLUSIONS: Homozygosity for Asp298, a common variant of the eNOS gene, is an independent risk factor for carotid atherosclerosis in this study population.

Adult↗
PubMed2000

Dissection of the bifunctional Escherichia coli N-acetylglucosamine-1-phosphate uridyltransferase enzyme into autonomously functional domains and evidence that trimerization is absolutely required for glucosamine-1-phosphate acetyltransferase activity and cell growth.

The bifunctional N-acetylglucosamine-1-phosphate uridyltransferase (GlmU) enzyme catalyzes both the acetylation of glucosamine 1-phosphate and the uridylation of N-acetylglucosamine 1-phosphate, two subsequent steps in the pathway for UDP-N-acetylglucosamine synthesis in bacteria. In our previous work describing its initial characterization in Escherichia coli, we proposed that the 456-amino acid (50.1 kDa) protein might possess separate uridyltransferase (N-terminal) and acetyltransferase (C-terminal) domains. In the present study, we confirm this hypothesis by expression of the two independently folding and functional domains. A fragment containing the N-terminal 331 amino acids (Tr331, 37.1 kDa) has uridyltransferase activity only, with steady-state kinetic parameters similar to the full-length protein. Further deletion of 80 amino acid residues at the C terminus results in a 250-amino acid fragment (28.6 kDa) still exhibiting significant uridyltransferase activity. Conversely, a fragment containing the 233 C-terminal amino acids (24.7 kDa) exhibits acetyltransferase activity exclusively. None of these individual domains could complement a chromosomal glmU mutation, indicating that each of the two activities is essential for cell viability. Analysis of truncated GlmU proteins by gel filtration further localizes regions of the protein involved in its trimeric organization. Interestingly, overproduction of the truncated Tr331 protein in a wild-type strain results in a rapid depletion of endogenous acetyltransferase activity, an arrest of peptidoglycan synthesis and cell lysis. It is shown that the acetyltransferase activity of the full-length protein is abolished once trapped within heterotrimers formed in presence of the truncated protein, suggesting that this enzyme activity absolutely requires a trimeric organization and that the catalytic site involves regions of contact between adjacent monomers. Data are discussed in connection with the recently obtained crystal structure of the truncated Tr331 protein.

Acetyltransferases↗
PubMed2000

Identification of the Pseudomonas aeruginosa glmM gene, encoding phosphoglucosamine mutase.

A search for a potential algC homologue within the Pseudomonas aeruginosa PAO1 genome database has revealed an open reading frame (ORF) of unknown function, ORF540 in contig 54 (July 1999 Pseudomonas genome release), that theoretically coded for a 445-amino-acid-residue polypeptide (I. M. Tavares, J. H. Leitão, A. M. Fialho, and I. Sá-Correia, Res. Microbiol. 150:105-116, 1999). The product of this gene is here identified as the phosphoglucosamine mutase (GlmM) which catalyzes the conversion of glucosamine-6-phosphate to glucosamine-1-phosphate, an essential step in the formation of the cell wall precursor UDP-N-acetylglucosamine. The P. aeruginosa gene has been cloned into expression vectors and shown to restore normal peptidoglycan biosynthesis and cell growth of a glmM Escherichia coli mutant strain. The GlmM enzyme from P. aeruginosa has been overproduced to high levels and purified to homogeneity in a six-histidine-tagged form. Beside its phosphoglucosamine mutase activity, the P. aeruginosa enzyme is shown to exhibit phosphomannomutase and phosphoglucomutase activities, which represent about 20 and 2% of its GlmM activity, respectively.

Cloning, Molecular↗
PubMed2000

Autophosphorylation of phosphoglucosamine mutase from Escherichia coli.

Phosphoglucosamine mutase (GlmM) catalyzes the formation of glucosamine-1-phosphate from glucosamine-6-phosphate, an essential step in the pathway for UDP-N-acetylglucosamine biosynthesis in bacteria. This enzyme must be phosphorylated to be active and acts according to a ping-pong mechanism involving glucosamine-1, 6-diphosphate as an intermediate (L. Jolly, P. Ferrari, D. Blanot, J. van Heijenoort, F. Fassy, and D. Mengin-Lecreulx, Eur. J. Biochem. 262:202-210, 1999). However, the process by which the initial phosphorylation of the enzyme is achieved in vivo remains unknown. Here we show that the phosphoglucosamine mutase from Escherichia coli autophosphorylates in vitro in the presence of [(32)P]ATP. The same is observed with phosphoglucosamine mutases from other bacterial species, yeast N-acetylglucosamine-phosphate mutase, and rabbit muscle phosphoglucomutase. Labeling of the E. coli GlmM enzyme with [(32)P]ATP requires the presence of a divalent cation, and the label is subsequently lost when the enzyme is incubated with either of its substrates. Analysis of enzyme phosphorylation by high-pressure liquid chromatography and coupled mass spectrometry confirms that only one phosphate has been covalently linked to the enzyme. Only phosphoserine could be detected after acid hydrolysis of the labeled protein, and site-directed mutagenesis of serine residues located in or near the active site identifies the serine residue at position 102 as the site of autophosphorylation of E. coli GlmM.

Adenosine Triphosphate↗
PubMed2000

Sympathetic nervous system and hypertension in diabetic patients.

Although it has been demonstrated that the sympathetic nervous system participates in the genesis of essential hypertension, it is still unclear whether this system can also account for the increased incidence of arterial hypertension in diabetic patients. However, there are some observations which make this hypothesis extremely likely. In fact, it has been demonstrated that in diabetic normotensive patients the reflex control of the sympathetic discharge is normal, but in hypertensive patients there are some derangements of the autonomic nervous tone control which may contribute to increasing the incidence of arterial hypertension in patients with Type 2 diabetes mellitus. In particular, on the one hand, it has been reported that in hypertensive patients hyperinsulinemia is able to induce a reflex activation of the sympathetic tone which is 3-fold higher than that observed in normotensive subjects. On the other hand, it has been demonstrated that this abnormal sympathetic response is particularly harmful in subjects prone to develop essential hypertension since they are characterized by vascular insulin resistance, which plays a permissive role in the development of essential hypertension. Vascular insulin resistance is a type of endothelial dysfunction which impairs the insulin modulation of the vascular effects of sympathetic nervous activation.

Diabetes Complications↗
PubMed1999

Crystal structure of the bifunctional N-acetylglucosamine 1-phosphate uridyltransferase from Escherichia coli: a paradigm for the related pyrophosphorylase superfamily.

N-acetylglucosamine 1-phosphate uridyltransferase (GlmU) is a cytoplasmic bifunctional enzyme involved in the biosynthesis of the nucleotide-activated UDP-GlcNAc, which is an essential precursor for the biosynthetic pathways of peptidoglycan and other components in bacteria. The crystal structure of a truncated form of GlmU has been solved at 2.25 A resolution using the multiwavelength anomalous dispersion technique and its function tested with mutagenesis studies. The molecule is composed of two distinct domains connected by a long alpha-helical arm: (i) an N-terminal domain which resembles the dinucleotide-binding Rossmann fold; and (ii) a C-terminal domain which adopts a left-handed parallel beta-helix structure (LbetaH) as found in homologous bacterial acetyltransferases. Three GlmU molecules assemble into a trimeric arrangement with tightly packed parallel LbetaH domains, the long alpha-helical linkers being seated on top of the arrangement and the N-terminal domains projected away from the 3-fold axis. In addition, the 2.3 A resolution structure of the GlmU-UDP-GlcNAc complex reveals the structural bases required for the uridyltransferase activity. These structures exemplify a three-dimensional template for the development of new antibacterial agents and for studying other members of the large family of XDP-sugar bacterial pyrophosphorylases.

Acetyltransferases↗
PubMed1998

Indomethacin increases the effect of isosorbide dinitrate on cerebral hemodynamic in migraine patients: pathogenetic and therapeutic implications.

Intracerebral vascular reactivity induced by the nitric oxide (NO) donor isosorbide dinitrate (IDN, 5 mg sublingually) is more major and longer-lasting in migraine patients who develop delayed headache in response to the drug. The headache is purportedly due to neuronally-mediated vascular mechanisms. Indomethacin inhibits prostaglandin synthesis, which is involved in NO generation. Indomethacin also decreases cerebral blood flow by constricting precapillary resistance vessels. In the present study, the hemodynamic effects of indomethacin were evaluated in migraine patients and healthy controls by means of transcranial Doppler monitoring. Indomethacin caused a significant decrease in mean flow velocity in the middle cerebral artery. This was an additional effect to the mean velocity decrease induced by IDN. The interactions between the two drugs suggest that their effects on cerebral hemodynamics (and pain) may be of relevance both in understanding the role of NO in migraine pathogenesis and in evaluating symptomatic treatments for migraine attacks.

Adult↗
PubMed1998

Probing the role of cysteine residues in glucosamine-1-phosphate acetyltransferase activity of the bifunctional GlmU protein from Escherichia coli: site-directed mutagenesis and characterization of the mutant enzymes.

The glucosamine-1-phosphate acetyltransferase activity but not the uridyltransferase activity of the bifunctional GlmU enzyme from Escherichia coli was lost when GlmU was stored in the absence of beta-mercaptoethanol or incubated with thiol-specific reagents. The enzyme was protected from inactivation in the presence of its substrate acetyl coenzyme A (acetyl-CoA), suggesting the presence of an essential cysteine residue in or near the active site of the acetyltransferase domain. To ascertain the role of cysteines in the structure and function of the enzyme, site-directed mutagenesis was performed to change each of the four cysteines to alanine, and plasmids were constructed for high-level overproduction and one-step purification of histidine-tagged proteins. Whereas the kinetic parameters of the bifunctional enzyme appeared unaffected by the C296A and C385A mutations, 1,350- and 8-fold decreases of acetyltransferase activity resulted from the C307A and C324A mutations, respectively. The Km values for acetyl-CoA and GlcN-1-P of mutant proteins were not modified, suggesting that none of the cysteines was involved in substrate binding. The uridyltransferase activities of wild-type and mutant GlmU proteins were similar. From these studies, the two cysteines Cys307 and Cys324 appeared important for acetyltransferase activity and seemed to be located in or near the active site.

Acetyltransferases↗
PubMed1997

Opposite effects of L-arginine and nitroglycerin on cerebral blood velocity: nitric oxide precursors and cerebral blood velocity.

Nitric oxide (NO), a gaseous molecule synthesized in the arteriolar endothelium from the amino acid L-arginine (L-arg), has been identified as the previously described Endothelium-Derived Relaxing Factor (EDRF): nitroderivatives such as nitroglycerin are known to induce vasodilation via NO release. The aim of this study was to evaluate by Transcranial Doppler (TCD) monitoring any changes in cerebral hemodynamics induced by both the infusion of L-arg and the sublingual administration of nitroglycerin in 20 healthy subjects. L-arg infusion induced a significant increase in blood velocity compared to the baseline value (mean +/- S.D. percent change = 18 +/- 8.71; p<0.0001 ) and a slight but significant decrease in Pulsatility Index. By contrast, nitroglycerin was able to cause a significant decrease in blood velocity (mean +/- S.D. percent change = 24.8 +/- 7.68; p<0.0001), while leaving Pulsatility Index unchanged. These data suggest that L-arg and nitroglycerin, both hypothesized to use NO as the final product at the vascular level, result in opposite blood velocity patterns within the cerebral circulation. This may be due to the particular type of artery and/or to the local endothelial environment whereby the released NO may act.

Adult↗
PubMed1994

Bilateral asymmetry of cerebral blood velocity in cluster headache.

In this study, 69 episodic cluster headache (CH) patients (40 in the active phase, 29 in remission period) underwent a complete TCD examination in order to verify the relationship between cerebral blood velocities (CBVs) and the clinical profile of the disease. Fifteen patients were examined during both phases, while 7 were monitored during a spontaneous attack. Sixty-three healthy sex and age-matched controls were also studied. We measured widespread, asymmetric CBV activation during the active phase, bilaterally in the anterior circulation and also in the posterior circulation. A relative reduction of CBV on the anterior cerebral artery pain side, also during remission, suggests a relationship between local vasodilation and the autonomic symptoms ipsilateral to pain during CH attacks.

Adult↗
PubMed1994

Determination of the kinetics of Na+/H+ exchange in platelets using the Coulter S-plus cell counter.

Cell swelling, as measured by electronic cell sizing, is a good indicator of the Na+/H+ exchange activation. In this study the kinetic properties of the Na+/H+ exchanger were determined with the aid of the Coulter S-Plus VI D haematological cell counter. Cell swelling was measured in platelets suspended in Na-propionate medium. The rapid entry and intracellular dissociation of propionic acid induces activation of the exchanger, and in turn the uptake of water by osmosis. The fractional volume increase measured by the Coulter S-Plus was dependent on the external Na-concentration, with Km = 86 mmol/l. Saturation was reached at a propionate concentration of 140 mmol/l. Inhibition by amiloride was dose-dependent with Ki = 24 mumol/l. The activity of the exchanger was not modified by ouabain. These data are generally consistent with those published in previous reports, and indicate that automated haematological analysers are appropriate for the study of this aspect of platelet function.

Amiloride↗
PubMed1994

[Effects of antihypertensive treatment on carotid vascular changes].

The carotid artery is one of the most important sites in the progression of atherosclerotic lesions. Atherosclerosis is known to be determined by a variety of factors, among which arterial hypertension is one of the most important. Blood pressure control by antihypertensive treatment is thus of great benefit in management of atherosclerosis, particularly in view of the direct action of some classes of antihypertensive agents on atheromatous lesions. Today, modern diagnostic technique allow a non-invasive examination of the artery wall (B-mode ultrasound and pulsed-Doppler), so that early detection of structural and functional alterations is possible. In order to evaluate the efficacy of the long term blood pressure reduction in the progression and/or in the regression of cardiovascular structural abnormalities, we studied intima-media thickness and arterial compliance during one-year antihypertensive treatment with a new calcium-antagonist, lacidipine, or a diuretic hydrochlorothiazide. In both groups we observed a comparable blood pressure reduction (lacidipine: from 166 +/- 5/100 +/- 1 to 142 +/- 4/88 +/- 2 mmHg; hydrochlorothiazide: from 154 +/- 5/102 +/- 2 to 140 +/- 4/88 +/- mmHg; both p < 0.01). On the contrary, only in patients treated with lacidipine did we obtain a significant improvement in carotid blood flow (383 +/- 16 vs 411 +/- 16 ml/min p <) and in arterial compliance (0.8 +/- 0.1 vs 1.2 +/- 0.2 cm/dyne p < 0.01). Indeed, we observed a different behaviour of the intima-media thickness in the two groups (lacidipine: 1.11 +/- 1.4 vs 1.13 +/- 1.5 mm n.s.; hydrochlorothiazide: 1.15 +/- 0.15 vs 1.21 +/- 0.17 mm p < 0.06). Our results demonstrate that an effective antihypertensive treatment with calcium antagonists may influence the progression of carotid vascular abnormalities.

Aged↗
PubMed1994

[Carotid vascular structural changes and left ventricular hypertrophy].

In the literature there are few studies evaluating carotid vascular atherosclerotic involvement in patients with essential arterial hypertension. Nowadays with new non-invasive methodological methods, such as Doppler-echotomography, it is possible to evaluate accurately structural vascular and cardiac changes. In this study we evaluated the relationship between carotid vascular structural changes and cardiac left ventricular mass index in 15 normotensive subjects and in 15 patients with essential hypertension. We performed a B-mode echotomography (7.5 MHz) of a common carotid in order to measure the diameter of the vessel and intima-media wall thickness. In the same subjects we determined echocardiographic left ventricular mass index and we measured arterial pressure by sphygmomanometric method. There was no statistical significant difference in the two groups except that in systolic, diastolic and mean arterial pressure (96 +/- 2 vs 123 +/- 2 mmHg, p < 0.01), left ventricular mass index (102 +/- 3 vs 118 +/- 3 g/m2, p < 0.01) and in the common carotid intima media wall thickness (0.91 +/- 0.01 vs 2.23 +/- 0.02 mm). In the normotensive subject mean arterial pressure correlated significantly with age (r = 0.699) and with common carotid arterial diameter (r = 0.523) (both p < 0.05). In hypertensive patients, on the contrary, mean arterial pressure correlated with left ventricular mass index (r = 0.523), carotid arterial diameter (r = 0.627) and common carotid intima media wall thickness (r = 0.847). These results demonstrate that in hypertensive patients cardiac abnormalities accompanied vascular structural changes.

Carotid Arteries↗
PubMed1994

[The effects of plasma cholesterol reduction on vasoconstriction due to sympathetic activation in patients with moderate primary hypercholesterolemia].

Recent studies have demonstrated that hypercholesterolemia is one of the major factor involved in the progression of coronary heart disease and that the reduction in plasma cholesterol reduces mortality for cardiovascular events. Indeed, recent experimental studies have demonstrated alterations in vascular reactivity in atherosclerosis. The aim of this study was to evaluate in patients with primary hypercholesterolemia the consequences of an effective of chronic treatment with inhibitor of HMG-CoA reductase on vascular responsiveness to cold pressure test. We observed a significant reduction in total plasma cholesterol during the study that was accompanied by a significant decrease in the response of peripheral vascular resistances to cold pressure test (55 +/- 4% vs 73 +/- 5% p < 0.01). There was also a significant relationship between the reduction of total cholesterol and the response of vascular resistance to the cold pressure test (r = 0.853, p < 0.05). Our results demonstrate that the reduction in total plasma cholesterol may influence the haemodynamic response induced by the activation of the sympathetic system.

Adult↗