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Biomedical subjects

M Giordano

Publications and source records attributed to M Giordano.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Hyperechogenicity of the renal medulla in children: clinico-echographic correlations].

Increased renal medullary echogenicity by renal ultrasound associated with hypercalciuria and nephrocalcinosis is often present in childhood. 17 children, 9 boys and 8 girls, aged from 8 months to 10 years were classified into three groups based on ultrasound findings according to Patriquin and Robitaille: type A faint hyperechogenic rim around the sides and tip of the medullary pyramid; type B more intense echogenic rim of the pyramids; type C intense echoes throughout the pyramid. Clinic-echographic correlations showed a pattern C in 4 children with distal renal tubular acidosis and in an infant treated with furosemide; pattern B in 3 patients having different types of tubulopathy associated with hypercalciuria; pattern A in 6 children with congenital tubulopathy and in 3 children treated with vitamin D. Abdominal X-rays detected medullary calcinosis in 2 (11.7%) of total 17 patients. Ultrasonography appears to be an important tool in early diagnosis of renal medullary nephrocalcinosis.

Acidosis, Renal Tubular↗
PubMed1996

[Echographic diagnosis of nephro-urological neoplasia in a pediatric nephrology center].

The use of ultrasound for the diagnosis of urologic neoplasms in simple and accurate. Nowadays nephrologists and urologists advocate the use of ultrasound and the procedure now plays a complementary role of the clinical examination. We present a retrospective study regarding our experience with ultrasonography in the diagnosis of urologic problems. In the period february 95-february 96 we performed 672 ultrasound examination on children ranging in age from 30 days to 16 years. All examinations were performed using a 3.5-5 MHz real time convex scanner. The patients were examined in the supine position for imaging of the bladder and in the prone position for imaging of the kidneys. We report 3 cases of neoplasm of the genito-urinary tract screened with the use of ultrasounds in a selected paediatric population.

Adolescent↗
PubMed1995

Homozygous tandem duplication within the gene encoding the beta-subunit of rod phosphodiesterase as a cause for autosomal recessive retinitis pigmentosa.

Autosomal recessive retinitis pigmentosa (ARRP) is a degenerative disease of photoreceptors in which defects in the rhodopsin and phosphodiesterase beta-subunit (PDEB) loci have been reported. To assess the involvement of PDEB in ARRP families from Spain, we screened a panel of 19 families for linkage to markers within or close to the PDEB gene. Homozygosity was also tested in cases of consanguinity. This combined approach ruled out PDEB as the cause of the disease in all but one of the families. Molecular characterization of the gene in that family (a consanguineous pedigree) revealed a homozygous 71-bp tandem duplication in exon 1 of the affected member, the parents being heterozygous. This defect causes a frameshift mutation which leads to a premature stop codon, suggesting that this mutant allele is the underlying cause of ARRP in this patient. According to the data presented here, the PDEB gene is not the main gene responsible for ARRP, but accounts for about 5% of the cases.

Base Sequence↗
PubMed1995

Involvement of nitric oxide in the regulation of peripheral blood leukocyte counts.

A role for nitric oxide (NO) in the regulation of blood leukocyte numbers was examined in BALB/c mice by employing the NO synthase inhibitor NG-nitro L-arginine methyl ester (L-NAME). Treatment of animals with a single dose of 50 mg/kg body wt caused a dramatic increase in the number of circulating neutrophils and a moderate decrease in the number of circulating lymphocytes. These effects were partially reversed by the simultaneous inoculation of L-arginine (250 mg/kg body wt.) but not by D-arginine. A second NO synthase inhibitor, NG-nitro L-arginine, induced changes comparable to those elicited by L-NAME. Because catecholamines and glucocorticoids are well-known modulators of blood leukocyte counts, experiments were carried out in adrenalectomized mice. It was found that adrenalectomy did not modify the increase in the number of circulating neutrophils induced by L-NAME but completely prevented the decrease of circulating lymphocytes. Taken together, these findings support the hypothesis that NO plays an important role in the regulation of the peripheral blood number of neutrophils and lymphocytes, and that this function involves, in each case, the participation of different mechanisms.

Animals↗
PubMed1995

Low bcl-2 expression and increased spontaneous apoptosis in T-lymphocytes from newly-diagnosed IDDM patients.

The bcl-2 gene product has been shown to regulate apoptotic cell death, and its dysregulation has been shown to induce several abnormalities in the immune system. No data exist regarding bcl-2 expression in autoimmune diseases, such as human insulin-dependent diabetes mellitus (IDDM). We investigated bcl-2 protein expression by testing T lymphocytes from 15 newly-diagnosed (< 3 weeks) IDDM patients in comparison to 10 age-matched control subjects. The expression of bcl-2 on CD3+ lymphocyte subsets was investigated after membrane permeabilization by two- or three-colour immunofluorescence. When the percentage and mean fluorescence intensity (MFI) of bcl-2+/CD3+ cells from normal individuals and patients were compared, we found that bcl-2 expression within the CD3+ and CD4+ CD45R0+ T-cell populations was reduced significantly in IDDM patients (46.8 +/- 15.4 vs 79.6 +/- 11.7; 25.7 +/- 3.8 vs 47.15 +/- 5.7, respectively; p < 0.001). To establish whether low bcl-2 expression in T cells from newly-diagnosed patients reflects their susceptibility to death by an apoptotic process, we also evaluated DNA staining with propidium iodide in CD3+ lymphocyte suspension after a (24-72 h) culture period (spontaneous apoptosis). We found that IDDM patients have higher levels of spontaneous apoptosis (mean +/- SEM: 24 h = 4.6 +/- 0.8; 48 h = 9.9 +/- 1; 72 h = 12.8 +/- 1.1) than control subjects (24 h = 1.8 +/- 0.4; 48 h = 4.6 +/- 0.4; 72 h = 5.7 +/- 0.3; p < 0.02-0.001). Our study suggests that recent onset IDDM is characterised by reduced bcl-2 expression, which in turn may be associated with the increased spontaneous apoptosis we observed.

Adolescent↗
PubMed1995

Defective expression of the apoptosis-inducing CD95 (Fas/APO-1) molecule on T and B cells in IDDM.

Triggering of CD95 (Fas/APO-1) cell surface receptors regulates the elimination of autoreactive T and B lymphocytes through a mechanism of cell suicide called apoptosis. Three different mutations involving CD95 or its ligand are responsible for induction of autoimmunity in susceptible mouse strains. To determine whether a defect involving the CD95 receptor is associated with human insulin-dependent diabetes mellitus (IDDM), we have studied the expression of CD95 on peripheral blood mononuclear cells from IDDM patients at different stages of the disease. Three-colour flow cytometry and mean fluorescence analysis showed that T and B lymphocytes from newly diagnosed IDDM and patients with long-standing disease, and subjects at high risk of developing the disease were highly defective in CD95 expression (p < 0.001), whereas monocytes from all the groups studied expressed normal amounts of CD95 molecules on their cell surface. T-cell subset analysis showed that the impairment of CD95 expression in IDDM patients and high-risk subjects involved both CD3+ CD4+ (p < 0.001) and CD3+ CD8+ cells (p range: < 0.01-0.001), suggesting that this alteration concerns both helper and cytotoxic T cells. Moreover, after activation in vitro with anti-CD3 monoclonal antibody, T cells from newly diagnosed IDDM patients maintained a reduced CD95 expression during the entire cell culture period (24-72 h) in comparison to the control population (p < 0.001). In conclusion, we found a reduced expression of the apoptosis-inducing CD95 receptor on T and B lymphocytes of individuals with clinical and preclinical IDDM. We hypothesize that this defective expression may impair the capacity of autoreactive lymphocytes to undergo CD95-mediated apoptosis, contributing to the lack of control on beta-cell specific B- and T-cell clones.

Adult↗
PubMed1995

Comparison of the effects of human recombinant insulin-like growth factor I and insulin on plasma amino acid concentrations and leucine kinetics in humans.

We examined the effects of recombinant human insulin-like growth factor I (IGF-I) and insulin on the plasma amino acid (AA) profile and leucine kinetics in eight normal subjects. IGF-I was infused at 52 pmol.kg-1.min-1, in combination with prime-continuous [1-14C] leucine infusion, to obtain steady-state plasma concentrations of total (54 +/- 3 nmol/l) and free (7.3 +/- 1 nmol/l) IGF-I (study 1). In response to IGF-I, plasma AA levels declined by 37 +/- 3% (1975 +/- 198 to 1368 +/- 120 mumol/l) and total branched chain amino acids (BCAA) declined by 34 +/- 3% (390 +/- 21 to 256 +/- 13 mumol/l). This hypoaminoacidaemic effect was associated with a decline in endogenous leucine flux of 17 +/- 2% (1.88 +/- 0.05 to 1.57 +/- 0.04 mumol.kg-1.min-1) and leucine oxidation of 17 +/- 1% (0.31 +/- 0.02 vs 0.26 +/- 0.02 mumol.kg-1.min-1) (both p < 0.01 vs basal). The same subjects underwent a second study (study 2) in which insulin was infused at 6.22 pmol.kg-1.min-1 to obtain a steady-state plasma insulin concentration of 530 +/- 25 pmol/l while maintaining euglycaemia. The infusion rate was designed to match the declines in plasma BCAA levels and leucine turnover observed during IGF-I infusion. The rates of glucose infusion necessary to maintain euglycaemia during IGF-I and insulin infusion were 4.9 +/- 1.0 and 7.8 +/- 0.6 mg.kg-1.min-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Atrial septal aneurysm and cardiac arrhythmias.

Atrial septal aneurysm has been associated with thromboembolic events, interatrial shunting, mitral valve prolapse, and systolic click. An association between atrial septal aneurysm and cardiac arrhythmias has been also described. Twenty patients with atrial septal aneurysm and 19 control subjects performed 24-h Holter monitoring. Frequent (> 10/h) atrial premature beats were observed in seven patients vs. none of the controls (P = 0.008). The mean number of episodes of supraventricular tachycardia and the prevalence of ventricular tachycardia were also higher in the atrial septal aneurysm group (P = 0.044 and P = 0.046, respectively). Left atrial enlargement, mitral valve prolapse and left ventricular hypertrophy were more frequent than in the normal subjects. In conclusion, atrial and ventricular 'complex' arrhythmias occurred more frequently in patients with atrial septal aneurysm than in normal subjects. Further studies in patients with atrial septal aneurysm without other associated echocardiographic abnormalities need to be done to ascertain a potential arrhythmogenicity of this condition.

Adult↗
PubMed1995

Problems arising in correlating clinical and molecular data in myotonic dystrophy.

The number of copies of CTG trinucleotide repeats in the myotonic dystrophy gene correlates to a certain degree with the clinical symptoms in the patient. Routine molecular analysis of myotonic dystrophy is performed on peripheral blood cells detecting the size of the expansion in leukocytes. However, in some cases somatic mosaicism is responsible for the presence of differently sized myotonic dystrophy alleles in different tissues of the same affected individual, complicating diagnosis and prognosis. Here we report two cases in which the correlation between molecular and clinical analysis performed with standard procedures posed some interpretative problems. The first individual was affected by an atypical clinical picture of myotonic dystrophy, the severity of which was not correlated with the low number of triplet repeats detected in his leukocyte DNA. The second case illustrates a prognostic problem in the presence of a low degree expansion in leukocytes. These examples outline the limits of standard molecular and clinical analysis in myotonic dystrophy.

Adult↗
PubMed1995

Acute effect of human recombinant insulin-like growth factor I on renal function in humans.

We examined the acute effects of insulin-like growth factor I (IGF-I) on renal function in 8 normal subjects who received a 3-hour intravenous infusion of IGF-I at a rate of 0.4 micrograms/kg.min. After starting the IGF-I infusion, the plasma IGF-I concentration rose quickly and achieved a plateau after 90 min that was threefold above the basal value. During IGF-I infusion, progressive rises in glomerular filtration rate (from 93 +/- 4 to 121 +/- 6 ml/173 m2.min; p < 0.01) and renal plasma flow (from 529 +/- 31 to 703 +/- 55 ml/1.73 m2.min; p < 0.01) were observed, with no change in filtration fraction. The plasma levels of potassium and phosphate decreased significantly during the last 90 min of the study, while the plasma sodium concentration remained unchanged. A significant decrease in the fractional excretion of sodium, potassium, and phosphate was observed during the last 90 min of the IGF-I infusion period. The heart rate rose modestly with no change in mean arterial pressure. These findings show that, when administered acutely, IGF-I is a potent renal vasodilator, but is antinatriuretic. IGF-I also enhances potassium and phosphate uptake by extrarenal tissues and reduces renal potassium and phosphate excretion.

Adult↗
PubMed1995

Effects of angiotensin-converting enzyme inhibitors, Ca2+ channel antagonists, and alpha-adrenergic blockers on glucose and lipid metabolism in NIDDM patients with hypertension.

We compared the effects of captopril, nifedipine, and doxazosin on glucose and lipid metabolism in 30 hypertensive non-insulin-dependent diabetes mellitus (NIDDM) patients (age = 50 +/- 3 years; body mass index = 30 +/- 1 kg/m2). Of these patients, 9 were treated with captopril, 11 with nifedipine, and 10 with doxazosin for 12 weeks. Blood pressure, fasting plasma glucose (FPG) concentration, HbA1c, oral glucose tolerance test (OGTT), euglycemic insulin clamp, and plasma lipids were measured before and after a 3-month period. Mean arterial blood pressure (114 +/- 2 mmHg) was similar in all groups before initiating antihypertensive therapy and declined to 102 +/- 2 (captopril), 103 +/- 1 (nifedipine), and 103 +/- 2 (doxazosin) mmHg (P < 0.001). Baseline FPG (148 +/- 11 mg/dl) and HbA1c (6.3 +/- 1%) were similar in all groups and did not change significantly with treatment. Plasma glucose, insulin, and free fatty acid (FFA) concentrations during the OGTT were similar in all groups before antihypertensive treatment and did not change with captopril and nifedipine; after doxazosin, plasma glucose and FFA concentrations during the OGTT decreased (both P < 0.05) without change in plasma insulin response. Insulin-mediated glucose uptake (144 +/- 11 mg.m-2.min-1), glucose oxidation (76 +/- 4 mg.m-2.min-1), and nonoxidative glucose disposal (71 +/- 6 mg.m-2.min-1) were similar in all groups before the start of antihypertensive treatment and did not change in captopril and nifedipine groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1995

Raised plasma fibrinogen concentrations in subjects attending a metabolic ward--relation to family history and vascular risk factors.

We have evaluated plasma fibrinogen levels in 171 subjects attending a metabolic ward. As in the general population, a significant difference in plasma fibrinogen concentrations (p < 0.05) was found between subjects with diabetes mellitus or hypertension and those without. However, fibrinogen was also abnormally high (p < 0.05) when evaluated according to the presence of a family history of ischemic complications of atherosclerosis (p < 0.05). In this setting, fibrinogen correlated with diabetes mellitus or hypertension as well as with familial risk, and the latter interacted with hypertension (p < 0.05) in accounting for plasma fibrinogen. The relationships between certain fibrinogen genotypes and familial risk have then been evaluated. Analysis of a locus (1.3 kb, HAE III digestion) of the promoter region of the B beta fibrinogen gene, identified a polymorphic cutting site. The allele with the alternative restriction site (H1) was associated with mean fibrinogen levels which were 0.1-0.3 g/l lower than those associated with the other allele (H2). This difference was not statistically significant. No obvious association was found between the familial risk and the presence of the H2 allele. We conclude that in a group of subjects from a metabolic ward, a positive family history for ischemic complications of atherosclerosis is consistently associated with high plasma fibrinogen levels. Interaction with hypertension significantly strengthens the association.

Adult↗
PubMed1995

[Planar determination of the aortic valve area with transesophageal echocardiography with multiplanar probe in patients with aortic stenosis and insufficiency. Comparison with transthoracic Doppler echocardiography].

BACKGROUND: The simple determination of transaortic pressure gradient does not accurately assess the severity of an aortic valve stenosis. Thus, estimating the aortic valve area (AVA) is vital for clinical decision-making. Cardiac catheterization has been considered the "gold-standard" for the quantification of the stenotic valve area, but this technique may underestimate the actual valve area when aortic regurgitation is associated. Doppler transthoracic echocardiography (TTE) with the continuity equation method is usually employed for AVA estimation. Recently, in pure aortic stenosis, transesophageal echocardiography (TEE) has provided AVA values well-correlated to hemodynamic invasive results. METHODS: In this study, we correlated AVA values by TTE and multiplane TEE in 18 patients with combined aortic valve stenosis and regurgitation. RESULTS: The mean values of AVA by TEE and TTE were 0.74 +/- 0.12 and 0.68 +/- 0.55 cm2, respectively (p = NS). TEE-derived AVA correlated well to TTE-derived AVA (r = 0.816; p < 0.0001). Critical aortic stenosis was predicted by TEE with 100% sensitivity and specificity. Total time of examination was significantly longer for TTE (p < 0.00001). CONCLUSIONS: In conclusion, direct planimetry by multiplane TEE is a reliable method for AVA determination in aortic stenoinsufficiency. For this purpose, when the technical quality of TTE study is poor or when the patient is critically ill and does not tolerate a longer lasting TTE, multiplane TEE should be considered.

Adult↗