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Biomedical subjects

G Vignati

Publications and source records attributed to G Vignati.

At least 19 recordsLinked to original sources
PubMed2004

The utility of specific immunoglobulin E measurements in primary care.

BACKGROUND: The identification of atopic patients may not be considered a necessary step in the diagnosis process in primary care. This study investigated the impact of the addition of a specific immunoglobulin E (IgE) antibody test on the current management by primary-care physicians of patients with respiratory and skin symptoms. METHODS: The study had a prospective before-after design. It was conducted in two geographic areas of Italy and Spain and consisted of two parts, Part I and Part II. In each part patients were recruited according to inclusion and exclusion criteria. After the clinical examination, the patients were classified into one of the following categories using a physician's classification: allergic, nonallergic or uncertain. A blood sample was taken from each included patient for specific IgE antibody determination using a Pharmacia CAP System, including either Phadiatop Infant (0-5 years of age) or Phadiatop and food mix (fx5e) (>5 years of age). If a positive result was found, an additional 6-26 specific IgE tests were performed. In Part I the result of the specific IgE antibody determinations was not available before the physician's classification was made. In contrast, in Part II, the result of the IgE test was available at the time when the physician's classification was made. Between Part I and Part II an educational intervention for physicians to improve their knowledge of blood testing for IgE-mediated allergy was carried out. RESULTS: A total of 721 patients were included in the study. The agreement between classifications based on clinical data and IgE antibody results changed from a kappa coefficient of 0.13 in Part I to 0.86 in Part II. With regard to the allergic status the proportion of uncertain cases was reduced from 26.3% in Part I to 4.1% in Part II. The proportion of patients that were advised to avoid allergens increased from 18% in Part I to 62% in Part II in the group of patients classified both by the clinician and the IgE test. CONCLUSIONS: The use of specific IgE antibody determinations improves the clinical management of patients with allergy related symptoms in primary care, allowing advice to be given on specific allergen avoidance. However, the applicability of this diagnostic tool in different areas and countries should be further assessed in cost-effectiveness studies.

Adolescent↗
PubMed2003

Fontan conversion to total cavopulmonary connection and arrhythmia ablation: clinical and functional results.

OBJECTIVES: To assess the early results of conversion from atriopulmonary to total cavopulmonary connection in patients with failing Fontan operation. DESIGN: Early clinical and instrumental evaluation of patients undergoing conversion from atriopulmonary to total cavopulmonary connection from April 1999 to November 2000. SETTING: Tertiary referral centre for congenital heart disease. PATIENTS: 11 Fontan patients (mean (SD) age 20.9 (6.7) years) with refractory arrhythmias or ventricular dysfunction. INTERVENTIONS: Total cavopulmonary connection, intraoperative ablation, and AAIR pacemaker implantation. MAIN OUTCOME MEASURES: Holter monitoring, transoesophageal atrial stimulation, ergometric test, and myocardial scintigraphy at a mean (SD) follow up of 16.8 (5.6) months. RESULTS: One early postoperative death occurred. During follow up three patients had relapse of atrial tachycardia, controlled by medical treatment, and two were pacemaker dependent. Transoesophageal stimulation did not induce atrial tachycardia in any patient. Ergometric test showed a diminished exercise tolerance in all but one patient. Mean minute ventilation and maximum oxygen consumption were 62% and 40% of their respective predicted values. Myocardial scintigraphy showed reversal of rest or exercise dysfunction in five patients and improved systemic ventricular function in seven. Mean basal ejection fraction increased from 39.4% (95% confidence interval (CI) 32% to 46%) to 46.5% (95% CI 41.7% to 51.2%) and ejection fraction on effort from 42.3% (95% CI 33.9% to 50.7%) to 50.2% (95% CI 44.5% to 55.9%). CONCLUSIONS: Our data show that total cavopulmonary connection associated with intraoperative ablation and pacemaker implantation allows for better control of arrhythmias and improves ventricular function in the majority of patients with failing Fontan.

Adolescent↗
PubMed2003

Proposal for a new definition of congenital complete atrioventricular block.

The classic old definition of congenital heart block by Yater (1929) is still generally accepted: 'Heart block established in a young patient. There must be some evidence of the existence of the slow pulse at a fairly early age and absence of a history of any infection which might cause the condition after birth: notably diphtheria, rheumatic fever, chorea and congenital syphilis'. However, other definitions are used. We systematically reviewed 1825 cases from 38 separate studies. We conclude that complete AV blocks detected in utero in the absence of structural abnormalities differ from blocks detected later in life with respect to pathogenesis (they are generally associated with maternal anti-Ro/SSA antibodies), poorer childhood prognosis, increased risk of developing late-onset dilated cardiomyopathy, different maternal clinical features and increased risk of recurrence in future pregnancies. For these reasons we propose a new modern definition of congenital complete AV block which might be acceptable to cardiologists, rheumatologists, pediatricians and obstetricians: 'an AV block is defined as congenital if it is diagnosed in utero, at birth or within the neonatal period (0-27 days after birth)'.

Autoantibodies↗
PubMed2002

Thyroid function in physiological aging and in centenarians: possible relationships with some nutritional markers.

Changes in thyroid function are often described in elderly subjects; however, their pathophysiologic significance and the possible contributory role of both malnutrition and nonthyroidal illness are still debated. The aim of this cross-sectional study was to investigate thyroid function in relationship to some markers of the nutritional status in a group of healthy old subjects and in some centenarians living in nursing homes. Patients included 24 clinically healthy elderly women (age, 71 to 93 years), 24 clinically healthy centenarian women (age, 100 to 106 years), and 20 healthy young subjects (age, 22 to 33 years). Blood samples were drawn from each subject for the evaluation of thyroid-stimulating hormone (TSH), free triiodothyronine (FT(3)), free thyroxine (FT(4),) reverseT(3) (rT3), autoantibodies against thyroglobulin (AbTg) and against thyroid peroxidase (AbTPO), and for the main humoral nutritional markers. TSH and thyroid hormones were assayed by fluoroimmunometric method; rT3 and thyroid autoantibodies by radioimmunoassay (RIA) and enzyme chemiluminescent immunometric assay, respectively. The mean values of TSH, FT(3) and FT(4) fell within the normal range in both groups. However, by comparison to old controls, in centenarian subjects, TSH levels were significantly lower, whereas rT(3) concentrations were slightly, but significantly, increased. Autoantibodies positivity was found in 4.16% of centenarians and in 10.4% and 13.6% of old and young controls. Thus, the incidence of thyroid autoantibodies was lower in centenarians than in old controls. Except for transferrin, lower than the normal range in centenarians, all of the other nutritional markers evaluated fell within the laboratory range of normality. Total cholesterol levels were significantly reduced in centenarians by comparison to old controls. Our results showed an age-related decline of the TSH levels and a significant increase of the rT(3) concentrations in centenarians by comparison to old controls. These findings may be related to an age-dependent reduction of the 5'-deiodinase activity rather than to important changes of nutritional markers.

Adult↗
PubMed2001

Mutations in the cardiac ryanodine receptor gene (hRyR2) underlie catecholaminergic polymorphic ventricular tachycardia.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia is a genetic arrhythmogenic disorder characterized by stress-induced, bidirectional ventricular tachycardia that may degenerate into cardiac arrest and cause sudden death. The electrocardiographic pattern of this ventricular tachycardia closely resembles the arrhythmias associated with calcium overload and the delayed afterdepolarizations observed during digitalis toxicity. We speculated that a genetically determined abnormality of intracellular calcium handling might be the substrate of the disease; therefore, we considered the human cardiac ryanodine receptor gene (hRyR2) a likely candidate for this genetically transmitted arrhythmic disorder. METHODS AND RESULTS: Twelve patients presenting with typical catecholaminergic polymorphic ventricular tachycardia in the absence of structural heart abnormalities were identified. DNA was extracted from peripheral blood lymphocytes, and single-strand conformation polymorphism analysis was performed on polymerase chain reaction-amplified exons of the hRyR2 gene. Four single nucleotide substitutions leading to missense mutations were identified in 4 probands affected by the disease. Genetic analysis of the asymptomatic parents revealed that 3 probands carried de novo mutations. In 1 case, the identical twin of the proband died suddenly after having suffered syncopal episodes. The fourth mutation was identified in the proband, in 4 clinically affected family members, and in none of 3 nonaffected family members in a kindred with 2 sudden deaths that occurred at 16 and 14 years, respectively, in the sisters of the proband. CONCLUSIONS: We demonstrated that, in agreement with our hypothesis, hRyR2 is a gene responsible for catecholaminergic polymorphic ventricular tachycardia.

Adolescent↗
PubMed2001

Risk of congenital complete heart block in newborns of mothers with anti-Ro/SSA antibodies detected by counterimmunoelectrophoresis: a prospective study of 100 women.

OBJECTIVE: To assess the true prevalence of congenital complete heart block (CCHB) in infants of anti-Ro/SSA-positive women known to have connective tissue disease (CTD) and, secondarily, to evaluate the prevalence of other electrocardiographic abnormalities in these newborns at birth. METHODS: A prospective study was conducted in 4 referral hospitals. One hundred anti-Ro/SSAA-positive mothers were followed up before they became pregnant and during the index pregnancy. Counterimmunoelectrophoresis and immunoblotting were used to test for antibodies to extractable nuclear antigens. RESULTS: Of the 100 women with anti-Ro/SSA antibodies, 2 had infants who developed CCHB in utero (2%). The CCHB was detected at 22 weeks and 20 weeks, respectively. One of the 2 mothers had primary Sjögren's syndrome (SS), and the other had undifferentiated CTD (UCTD). No case of CCHB occurred among the infants of 53 mothers with systemic lupus erythematosus (SLE). No fetal death occurred due to CCHB. In 2 centers, electrocardiography was recorded in 24 unselected newborns, and 4 were found to have sinus bradycardia. CONCLUSION: The prevalence of CCHB in newborns of prospectively followed up women already known to be anti-Ro/SSA positive and with known CTD was 2%. This finding is useful with regard to preconception counseling of these women. The risk of delivering an infant with CCHB may be higher in mothers with primary SS or UCTD than in those with SLE. Additional electrocardiographic abnormalities such as sinus bradycardia and prolongation of the QT interval may be present in their children.

Antibodies, Antinuclear↗
PubMed2000

Congenital intrapericardial aneurysm of the left atrial appendage.

Congenital aneurysmal dilatation of the left atrial appendage is a rare but correctable lesion. It represents a diagnostic dilemma in patients with cardiomegaly and is commonly associated with supraventricular arrhythmias and life-threatening systemic embolization. We describe the diagnostic evaluation and surgical treatment during 1997 of a patient with congenital aneurysmal dilatation of the left atrial appendage. The patient was discharged previously from our hospital in 1967 with the diagnosis of congenital dilatation of the pulmonary artery.

Child↗
PubMed2000

Clinical and electrophysiologic evolution of the Wolff-Parkinson-White syndrome in children: impact on approaches to management.

There is less certainty about the recommendations for radio-frequency ablation as a therapeutic option for Wolff-Parkinson-White syndrome in children as opposed to adults because of the different natural history and the age-related risks of ablation. To help decision-making, we evaluated the long term clinical evolution and electrophysiologic characteristics of pre-excitation in our series of children and young adults. We reviewed the clinical course of 109 patients below the age of 18 years who had been followed up over a period of 9+4 years, with a range from one to 27 years. This corresponded to 986 patient-years. We examined also the electrophysiologic data from 98 of those patients who underwent a transesophageal study. At the discovery of pre-excitation, 59% of patients were asymptomatic, while 29% developed supraventricular tachycardia during follow-up. The peak incidence of the onset of supraventricular tachycardia occurred during infancy. These patients had the highest incidence of subsequent spontaneous disappearance of the tachycardia (53%), such a favourable evolution being encountered in only 12% of patients in whom the abnormal rhythm first appeared after 12 years of age. Chronic medical treatment was required in 47% of patients, and proved completely effective in 45% of cases. The potential to induce atrial fibrillation, and the incidence pre-excitation considered to be high risk, with the shortest pre-excited RR interval equal to or less than 220 msec, was lowest in the group of patients aged less than 6 years of age, and highest in those older than 12 years of age (p <0.001). Pathways producing arrhythmia with high risk were more common in symptomatic (29%) than in asymptomatic patients (7%) (p<0.001). No mortality occurred. On the basis of our findings, we suggest that ablation should be avoided before the age of 5 or 6 years. Thereafter, the procedure should become the first line of treatment for symptomatic patients older than 12 years of age.

Adolescent↗
PubMed2000

The efficacy of hormone assays in the differential diagnosis of amenorrhea and menopause.

The differential diagnosis of menopause and amenorrhea is currently based on the assay of circulating follicle stimulating hormone, luteinising hormone, and estradiol. The diagnostic performance of the three hormone assays, both as single and combined tests, was evaluated considering as reference data the results from 300 subjects for either condition, and assuming menopause-amenorrhea prevalence ratios corresponding to 1 and 10. In the calculation an "allocation" scheme was adopted, and the uncertainty associated with the diagnostic performance parameters was accounted for. The results obtained clearly demonstrate that the addition of a test for luteinising hormone or estradiol (or both) to the testing for follicle stimulating hormone is not justified in terms of improvement of the diagnostic information.

Adolescent↗
PubMed1999

Thyroid hemiagenesis and elevated thyrotropin levels in a child with Williams syndrome.

A girl with Williams syndrome (WS) presented with elevated thyrotropin (TSH) levels (7.0 microU/ml), normal free thyroid hormone concentrations, and absent antithyroid autoantibodies. Thyroid ultrasonography and scintigraphy showed hemiagenesis of the left lobe and no evidence of ectopic tissue. TSH response to thyrotropin-releasing hormone (TRH) injection (200 microg/mq, i.v.) was exaggerated and prolonged, suggesting subclinical hypothyroidism. The biological activity of circulating TSH was slightly below the normal range [TSH bioactivity (B) to immunoreactivity (I) ratio (TSH B/I) = 0.4, normal: 0.6-2.2]. These abnormalities are similar to those seen in patients with hypothalamic hypothyroidism. Thyroid function is not a recognized manifestation of WS and is not routinely investigated. However, abnormalities of the hypothalamic-pituitary-thyroid (HPT) axis and thyroid dysgenesis have been found in other WS cases. Genes mapping at 7q11.23, contiguous to the chromosomal region deleted in most WS patients, may be involved in the development of the thyroid gland, contributing to the complex phenotype of WS.

Adult↗
PubMed1999

Serum glucagon concentration and hyperinsulinaemia influence renal haemodynamics and urinary protein loss in normotensive patients with central obesity.

OBJECTIVES: Insulin-resistance syndrome and hyperinsulinaemia are linked with cardiovascular disease (CVD) in the obese population. In particular, cardiovascular risk is more frequent in central obesity and is associated with microalbuminuria (MA). MA and changes of glomerular permeability to proteins in obesity might be related with renal haemodynamic modifications (that is glomerular hyperfiltration). Since glucagon is physiologically involved in renal haemodynamic regulation, the purpose of this study was to examine whether changes of circulating glucagon levels might haemodynamically induce MA and proteinuria in patients with central obesity. SUBJECTS: Forty normotensive obese out-patients, 22 with central (CO group) and 18 with peripheral (PO group) body fat distribution and 11 healthy subjects. MEASUREMENTS: Serum insulin and glucagon concentrations (fasting and after oral glucose tolerance test (OGTT)) by radio immuno assay (RIA); glomerular filtration rate (GFR, isotopic); total clearances and urinary excretion rates of albumin (AER), IgG (IgGER) and alpha1 microglobulin (computerized immunonephelometry). RESULTS: GFR and insulin concentrations (fasting and during OGTT) were higher in the CO than the PO group. Fasting glucagon concentrations were increased, and not physiologically suppressed during OGTT in patients with CO (fasting, P<0.05; OGTT 60 and 120 min, P<0.001 vs PO group). Moreover, glucagon concentrations were significantly correlated with GFR in the CO group (fasting, r=0.49, P<0.05; 60 min after OGTT, r=0.58, P<0.01); whereas no correlations were found in the PO group. Higher AER (P<0.001), IgGER (P<0.001) and alpha1 microglobulin (P<0.05) urinary concentrations were found in patients with CO than in the PO group. CONCLUSIONS: The increase of serum glucagon concentrations may be associated with the enhancement of GFR in patients with central obesity. Glomerular hyperfiltration might influence the development of MA and of proteinuria by means of a haemodynamic mechanism so contributing to increase the risk of renal microvascular complications and of CVD in central obesity.

Adult↗
PubMed1999

Dehydroepiandrosterone sulfate enhances natural killer cell cytotoxicity in humans via locally generated immunoreactive insulin-like growth factor I.

Experimental and clinical investigations suggest the hypothesis that dehydroepiandrosterone sulfate (DHEAS) can positively influence natural killer (NK) immunity via locally produced insulin-like growth factor I (IGF-I) from NK cells. In the present study, the NK cell cytotoxicity (NKCC) and IGF-I levels in the supernatant of NK cells were studied at baseline and after exposure to various molar concentrations of DHEAS (from 10(-5)-10(-8) mol/L x mL/7.75 x 10(6) NK cells) in healthy subjects of young and old age. DHEAS-induced NKCC was also determined after DHEAS coincubation with somatostatin-14 (10-6) mol/L x mL/7.75 x 10(6) NK cells) and with interleukin-2 (IL-2; 100 IU/mL x 7.75 x 10(6) NK cells). NK cells were previously isolated by Ficoll-Hypaque density gradient and then by immunomagnetic procedure; the purity obtained was 97 +/- 1%. NKCC was determined against K562 tumoral targets. We observed that the increase in NKCC after DHEAS exposure was dose dependent and was correlated with the amount of IGF-I released in the supernatant of cultured NK cells. NKCC and IGF-I generation from NK cells were more elevated in healthy elder subjects than in healthy young subjects. The coincubation of DHEAS with somatostatin-14 significantly suppressed NKCC and IGF-I release from NK in both groups, whereas higher NKCC was found after DHEAS plus IL-2 exposure than after incubation with DHEAS alone. Taken together, this study suggests a role for NK-generated IGF-I in the modulation of NKCC by DHEAS in humans. Although DHEAS may contribute to the IL-2-mediated NKCC, its activity on NK cytolytic function can be dependent on a autocrine mechanism (IGF-I-mediated), probably independent of cytokine activation. The higher NKCC response to DHEAS found in old subjects than in younger might counterbalance the age-dependent decline in circulating DHEAS, thus contributing to maintain the pattern of NK immunity during aging.

Adult↗
PubMed1999

[Clinical course of pre- and post-natal isolated congenital atrioventricular block diagnosed in utero].

We evaluated the pre- and postnatal outcome of isolated atrioventricular (AV) block detected during fetal life in order to identify factors that may affect the natural history of this lesion and to assess prenatal therapy. Over the past eight years, we consecutively evaluated 10 fetuses with complete AV block. The mean gestational age at diagnosis was 25.3 weeks and the mean heart rate was 57 bpm; two fetuses were hydropic. During pregnancy, one fetus suddenly died, while 6 out of 9 fetuses had a mean reduction in heart rate of 17.8 bpm; 4 patients had heart rate < 50 bpm. Five fetuses developed heart failure, which was severe in 2 cases and mild in 3. The mean gestational age at delivery was 31 weeks. Dexamethasone was administered to the mothers during pregnancy in 4 cases without modification of AV block and/or of heart rate, but in 3 out of 4 fetuses the general condition remained stable in spite of the reduction in heart rate in two of them. Sympathomimetic drugs were employed in 3 cases with an increase in fetal heart rate, but maternal discomfort appeared in two cases. Three newborns died during the first week of life, two of hydrops and one of persistent pulmonary hypertension. Cardiac pacing was performed in 6/9 patients within the first 8 months of life and in 3 within the first 2 days. In conclusion, morbidity and mortality are high when AV block is detected during fetal life. Negative prognostic factors are hydrops and a heart rate < 50 bpm. Pre-term delivery to enable cardiac pacing is probably the therapy of choice if gestational age is > 27-28 weeks. Sympathomimetic drugs are effective but are poorly tolerated by the mothers. Dexamethasone has no effect on AV block and/or heart rate, but may improve clinical tolerance of conduction disturbance.

Adult↗
PubMed1998

[The prevalence and characteristics of persistent pulmonary hypertension of the newborn. A multicenter study. The Study Group of the Società Italiana di Cardiologia Pediatrica (SICP)].

BACKGROUND: Persistent pulmonary hypertension of the newborn (PPHN) is a rare syndrome with a severe prognosis, in which a prompt diagnosis can be life-saving. The aim of our study was to verify its prevalence in a neonatal population, define clinical and echocardiographic criteria for the diagnosis of PPHN and discuss therapeutic choices. METHODS: The following clinical and echocardiographic criteria for the diagnosis of PPHN were defined: 1. cyanosis and hypoxemia non-responsive to O2 therapy; 2. right to left shunt at an atrial or ductal level. All neonates fulfilling these criteria referred to the neonatal units of seven pediatric or general hospitals over a two-year period were enrolled. RESULTS: From January 1995 to December 1996, thirty neonates with PPHN (8%) were observed. Birth was pre-term in 5 out of 30. Ten (33%) had experienced chronic and/or fetal asphyxia (FA). Death occurred in 7 (22%), four of whom with FA. Echocardiography showed tricuspid insufficiency in 18 (60%); mean pulmonary systolic pressure was 67 +/- 16 mmHg (range 41-95). In 23 surviving neonates, normalization of clinical and echocardiographic parameters occurred in 8 +/- 5 days. THERAPY: In most neonates, vasodilators (tolazoline, prostacyclin) and/or nitric oxide were employed. CONCLUSIONS: PPHN is confirmed to be a rare pathological condition; prognosis is severe, particularly in neonates with FA. Echocardiography is a reliable non-invasive method for a prompt diagnosis and follow-up. Subsequent studies are needed to assess therapeutic choices.

Echocardiography↗