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Biomedical subjects

L Ferrara

Publications and source records attributed to L Ferrara.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Syndrome X and microvascular angina].

The term X syndrome is used to indicate a group of patients who present anginous symptoms and ischemic-type electrocardiographic alterations which appear during exercise tolerance tests, dipiridamol tests or Holter's dynamic monitoring where coronary ultrasonography reveals no evident coronary lesions, vasospastic angina, arterial hypertension and/or diabetes mellitus, block of the left branch when resting or exercising, cardiomyopathy or valvulopathy. The highest incidence is in females with a mean age of around 50. A reduced reserve of coronary flow, highlighted both in response to vasodilatators or rapid stimulation and by positron emission tomography (PET), underlies this syndrome. It is thought to be caused by a dysfunction of the coronary microcirculation which consists in a deficit of the endothelium-dependent vasodilatory mechanisms, probably also owing to the accumulation of vasoconstrictive type substances, like endothelin-1. In addition to a dysfunction of the coronary microcirculation, one widely backed hypothesis concerns the existence of an altered perception of painful symptoms in patients with X syndrome: the anomalous constriction of prearteries might cause an increased release of adenosine, able to provoke angina despite the scarce signs of myocardial ischemia in terms of the metabolic or functional profile. From a therapeutic point of view, treatment of these patients is often ineffective: treatment should be based on the use of nitrates, calcium-antagonists or beta-blockers, if necessary moving on to other forms of therapy (aceinhibitors, xanthine methylate, estrogens, alphablockers, imipramine); the simultaneous use of tranquillizers may be useful in view of the anxious personality often characteristic of these patients.

Female↗
PubMed1998

Essential hypertension: leukocyte rheology and polymorphonuclear cytosolic Ca2+ content at baseline and after activation.

In 24 hypertensives we evaluated, at baseline, the leukocyte filtration parameters (using the St. George's Filtrometer), polymorphonuclear (PMN) membrane fluidity (with the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene [TMA-DPH]) and PMN cytosolic Ca2+ content (with the fluorescent probe Fura 2-AM). In a subgroup of hypertensives (n = 17) the PMN filtration parameters, PMN membrane fluidity and cytosolic Ca2+ content were evaluated after in vitro chemotactic activation (prolonged for 5 and 15 min) with two stimulating agents (4-phorbol 12-myristate 13-acetate [PMA] and N-formyl-methionyl-leucyl-phenylalanine [fMLP]). It was evident, from the baseline data, that there was a significant difference in the mononuclear (MN) initial relative flow rate (IRFR), clogging rate (CR) and clogging particles (CP), and in PMN cytosolic Ca2+ content. There were, however, no differences in the filtration parameters of unfractionated leukocytes and PMNs or in PMN membrane fluidity. After activation, in normals and in hypertensives, a significant variation in PMN filtration parameters was evident. In normals no variation was present in PMN membrane fluidity or cytosolic Ca2+ content after activation. In hypertensives, however, we found an increase solely in PMN cytosolic Ca2+ content after fMLP activation. After PMN activation (at 15 min) one parameter (IRFR) of PMN filtration distinguished normal subjects from hypertensives. No difference between the two groups was found in PMN membrane fluidity or PMN cytosolic Ca2+ content after PMN activation.

Adult↗
PubMed1998

[Incremental doses of diltiazem in patients with coronary artery disease in end-stage renal failure maintained on hemodialysis: which is the optimal dose?].

End-stage renal disease patients on maintenance hemodialysis suffering from coronary artery disease probably receive too low doses of calcium-antagonists, because the attempt to avoid adverse effects prevails the well-documented antianginal activity of the drug. The aim of our study was to assess the safety and efficacy of incremental doses of diltiazem in treating angina pectoris in hemodialyzed patients with coronary artery disease, to identify the optimal dose. Ninety-four chronic hemodialyzed patients (59 males and 35 females; mean age 55.2 +/- 3.3 years; on periodic dialysis for 80.3 +/- 25.6 months) with coronary artery disease and more than 5 min of transient myocardial ischemia during 48 hours of Holter monitoring were included in the study. A double-blind, randomized, placebo-controlled trial design was used. Incremental doses of diltiazem (from 120 to 240 mg/day) were administered in 4 months. At doses of 120 and 180 mg/day it was observed a statistically significant reduction in the number and duration of total and symptomatic ischemic episodes in 48 hours, compared with baseline (p < 0.001). Instead, the number and the duration of silent ischemic episodes did not significantly change (NS). The efficacy on silent myocardial ischemia was obtained only with the dosage of 240 mg/day (p < 0.001). If this dosage was obtained with a sustained-release formulation (120 mg twice a day), the efficacy was similar to the administration of 4 tablets/day of 60 mg, but the tolerability was better, especially during dialysis. The circadian variations of transient ischemic episodes showed two peaks in the 24 hours, one from 6.00 to 9.00 a.m. and another from 4.00 to 8.00 p.m., just during the dialysis. Both peaks were reduced only with 240 mg/day. In conclusion, this study demonstrates that sustained-release diltiazem (120 mg twice a day) is greatly useful in patients with coronary artery disease on maintenance dialysis because it reduces the frequency of silent ischemic episodes, has a good tolerability, and modifies the circadian pattern of ischemic episodes, reducing both peaks during the day.

Calcium Channel Blockers↗
PubMed1997

In vivo relationship between insulin and endothelin role of insulin-resistance.

Since endothelin production is stimulated in vitro by insulin, we performed this study to evaluate in vivo the relationships between endothelin and insulin plasma levels during a glucose load. We studied 28 subjects; 17 with normal glucose tolerance (NGT) and 11 with impaired glucose tolerance (IGT). Ten of the subjects in this study were normotensive and 18 with mild to moderate hypertension. Age, sex and body mass index were comparable among the groups. After a 2-week period of washout they underwent an oral glucose tolerance test; blood was drawn at 0 (basal), 90 and 120 min after the load for determination of glucose, insulin, C-peptide of insulin and endothelin-1 and -2. Basal endothelin in all the subjects under study was correlated with basal insulin; moreover it was negatively related with the glucose:insulin ratio that has been considered as an insulin-sensitivity index and positively with the insulin:C-peptide ratio as hepatic insulin-resistance index. The relationship between basal endothelin and insulin values was also found in each glucose tolerance group. At 120 min after the glucose load, mean plasma values of endothelin were significantly higher (6.66 +/- 1.31 vs 4.17 +/- 0.61 pmol/L); moreover, the per cent increase of endothelin at 120 min was positively related to the per cent increase of insulin. Between the normotensive and hypertensive groups there were no significant differences in studied endothelin parameters. Our results appear to confirm that, even in vivo, insulin modulates circulating endothelin levels.

Adult↗
PubMed1997

[Effectiveness and tolerability of bisoprolol vs. nifedipine in uremic patients with ischemic cardiopathy in dialysis treatment].

The effects of bisoprolol on transient myocardial ischemia have been compared with those of nifedipine in patients with coronary artery disease in end-stage renal failure maintained on haemodialysis. We also evaluated the tolerability of both drugs. Sixty patients (42 males, 18 females, mean age 52 +/- 4 years) in renal failure maintained on haemodialysis, with coronary artery disease and more than four significant episodes of transient myocardial ischemia (> or = 1 min) during 48-hour Holter monitoring, were included in the study. All cardiovascular drugs were discontinued > or = 6 days before this 48-hour ambulatory ECG monitoring, with the exception of sublingual nitrates allowed for relief of anginal attacks. Patients were then randomized to receive either bisoprolol or nifedipine for 2 weeks. After a 15-day wash-out period, they were crossed over to receive either bisoprolol or nifedipine for other 2 weeks. Statistical analysis was carried out using the Student's t test. A p value < 0.01 was considered significant. Both bisoprolol and nifedipine reduced number and duration of transient ischemic episodes as well as the total ischemic burden. Reductions were statistically significant for both antianginal drugs. Only bisoprolol was effective in silent ischemia (p < 0.001). It also reduced heart rate (p < 0.001), while nifedipine raised it (p < 0.001). Both drugs reduced systolic and diastolic blood pressure. The circadian variations of transient ischemic episodes showed two peaks in the 24 hours. Both peaks were reduced with bisoprolol. Nifedipine brought a clear overall reduction in the number of episodes but the circadian pattern was unchanged. During the study, 10 patients taking bisoprolol and 12 patients taking nifedipine had drug adverse effects. No one of them had to be withdrawn from treatment. In conclusion, bisoprolol seems to be more useful than nifedipine because its effects, in transient ischemic episodes, are greatly superior to those of nifedipine, and because it is effective also in silent ischemia. Both drugs showed a good tolerability in these patients. Bisoprolol, reducing the two daily peaks of ischemic episodes frequency, has a protective role towards mortality due to coronary artery disease.

Adrenergic beta-Antagonists↗
PubMed1996

Insulin-like growth factor 1 and pressure load in hypertensive patients.

To verify the effect of a pressure load on the production of Insulin-like Growth Factor 1 (IGF1) in essential hypertensives, we studied 15 patients and 8 normotensive controls before and during orthostatism. Upright standing was characterized both in normals and in hypertensives by significant higher rate-pressure product [RPP = systolic blood pressure (mm Hg) x heart rate (beats/min)]. Proportional increases of RPP were significantly related to IGF1 values at the end of orthostatism and to proportional increases of IGF1 in hypertensive group but not in normotensive one. Our results confirm that IGF1 plasma levels in hypertensive patients are related to pressure load.

Adult↗
PubMed1996

Additional neoplasms and HCV infection in low-grade lymphoma of MALT type.

Several chronic inflammatory conditions and genetic alterations are likely to be involved in the pathogenesis of low-grade lymphoma of MALT type. In a well-characterized series of 27 patients with low-grade lymphoma of MALT type, we studied: (1) the incidence of other neoplasms, which might be indicative of genetic instability, apparently a characteristic of this disease; (2) the prevalence of serologic and molecular markers of HCV infection, which has been found in association with other lymphoproliferative disorders. Three patients had one or more additional cancers; a total of eight tumours, five of which occurred in the same patient, suggests the presence of some genetic instability in at least some cases of the disease. Rather unexpectedly, anti-HCV antibodies and HCV RNA sequences were documented in 50% of the patients examined, without elevation of serum transaminases. Of interest, the two patients with parotid and conjunctival MALT lymphomas, respectively, with a previous history of Sjögren's syndrome, were HCV positive. We suggest, for the first time, that HCV may be considered, in addition to Helicobacter pylori, as another potential infectious co-factor in the multistep pathogenesis of low-grade lymphomas of MALT type.

Adult↗
PubMed1996

Microalbuminuria, renal dysfunction and cardiovascular complication in essential hypertension.

OBJECTIVE: To evaluate the prevalence of microalbuminuria (albumin excretion rate, AER) in a wide hypertensive population, and to evaluate any relationship with cardiovascular damage and renal dysfunction. DESIGN: A transversal study. SUBJECTS AND METHODS: In 383 hospitalized Caucasian essential hypertensives (198 men, 185 women) of mean age 44 +/- 0.5 years and mean clinic blood pressure 170.3 +/- 0.95/ 103.4 +/- 0.47 mmHg, metabolic parameters, serum creatinine level (Cs), creatinine clearance rate (Ccs), 24 AER and plasma renin activity (PRA) were measured. Furthermore, each patient underwent 24 h ambulatory blood pressure monitoring (ABPM) and echocardiography to measure left ventricular mass, which was indexed both by body surface area to obtain left ventricular mass index (LVMI) and by height to obtain the left ventricular mass indexed for height (LVMH). By Doppler echocardiography, the diastolic compliance by early:late peak filling velocity ratio was analysed. The fundus oculi was also observed. Three subsets of hypertensives were obtained by dividing the 383 essential hypertensives on the basis of their AER: < or = 11 (group A), 11 < or = 20 (group B) and > 20 micrograms/min (group C). MAIN OUTCOME MEASURES: Microalbuminuria, creatinine clearance, PRA, ABPM, LVMI, LVMH, early:late peak filling velocity ratio, hypertensive retinopathy. RESULTS: Among the 383 essential hypertensives, AER was < 11 micrograms/min in 55% of the patients (group A), 18% had AER in the range 11-20 micrograms/min (group B) and 27% had AER > 20 micrograms/min (group C). In the entire essential hypertensive population the prevalence of left ventricular hypertrophy was 44.39% and hypertensive retinopathy was observed in 54.83%. Moreover, AER significantly correlated with clinic systolic blood pressure (SBP) and diastolic blood pressure (DBP), with 24 SBP and DBP and with 24 h daytime and night-time mean blood pressure (MBP). AER was correlated also with LVMH and creatinine clearance. The analysis of the three subsets revealed no differences in age, body mass index, serum creatinine level and PRA. Group C in comparison with group A showed higher values of clinic SBP, 24 h SBP, DBP and MBP, and of daytime and night-time MBP. Furthermore, in group C, LVMI and LVMH were significantly greater than in group A, with a prevalence of left ventricular hypertrophy of 55% in the former group. Group C showed a prevalence of hypertensive retinopathy of 69% whereas in group A the prevalence was 48%. In group C, AER was significantly correlated with serum creatinine level. CONCLUSIONS: The transversal phase of our research, performed in a homogeneous population of Caucasian essential hypertensives with no metabolic disturbances, confirms the relationship between blood pressure pattern and early glomerular changes in essential hypertensives without overt proteinuria. Furthermore, these results emphasize the role of microalbuminuria as a marker of early cardiac, renal and retinal structural and functional changes in essential hypertension. The longitudinal study, which is in progress, will confirm the prognostic value of microalbuminuria in essential hypertension.

Adult↗
PubMed1995

Nucleotide sequence of a cDNA coding for bovine mitochondrial aspartate aminotransferase.

Aspartate aminotransferase is a pyridoxal-phosphate dependent enzyme which plays a key role in cell metabolism. We describe the cloning and sequence analysis of the cDNA encoding bovine mitochondrial aspartate aminotransferase and compare the sequence with those of isoenzymes from other mammalian species. An adult bovine heart cDNA library constructed in lambda lambda gt11 was screened using two 32P-end labeled synthetic oligonucleotides. From the screening of the cDNA library two positive clones were isolated. A subclone in pEMBL18, 6B2, generated from the longest recombinant phage was further analyzed. This clone contains an insert of 2500 bp with an Open Reading Frame of 1287 bp that encodes a protein of 430 amino acids. The deduced amino acid sequence confirms previous results obtained by mass spectrometric sequencing. We calculated the percentage of amino acid identity for each protein pair and for each comparison the average number of amino acid substitution per site (Kaa); the lowest Kaa values were obtained from the comparison between the bovine and pig enzymes. This study shows that the rate of evolution of mammalian mitochondrial AspAT is lower and more constant than the equivalent cytosolic enzyme and adds to the growing body of knowledge on the evolution of the aspartate aminotransferase.

Amino Acid Sequence↗
PubMed1995

Pressure ulcer pain: assessment and quantification.

A cross-sectional study design was used to document perception of pressure ulcer pain in 132 patients in an acute care setting. Subjects were evaluated by means of the Folstein Mini-Mental State Examination, Beck's Depression Inventory, the Faces Pain Rating Scale, and the Visual Analog Scale for pain intensity. Charts were reviewed for demographic data and related medical treatments. The group comprised 44 subjects (33.3%) who were able to respond to the evaluation instruments and 88 subjects (66.7%) who were unable to respond to the evaluation tools. Forty-one percent of the respondents denied pressure ulcer pain and 59% reported pain of some type. According to the Faces Rating Scale, 32% of this group reported no pain and 68% reported some degree of pain. The respondents included 48% who scored below 24 on the Folstein Mini-Mental State Examination, indicative of cognitive impairment, and 52% who were found to be cognitively intact, with scores of 24 or above. Only 2% (n = 3) were given analgesics for pressure ulcer pain within 4 hours of the interview.

Adult↗
PubMed1995

G- and R-banding comparison of sheep (Ovis aries L.) chromosomes.

G- and R-banded chromosomes of 14 Gentile di Puglia sheep (Ovis aries L., 2n = 54) from southern Italy were compared at the 450-band level (ISCNDA, 1989). GTG-, GBG-, RBG-, and RBA-banding techniques were employed on slides obtained from blood cell cultures that had incorporated BrdU either early or late in the replication cycle. The banding comparison improved the characterization of sheep chromosomes and allowed the construction of G- and R-banded idiograms using only one common banding nomenclature. Detailed descriptions of some disputed chromosomes are reported.

Animals↗