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M Sampietro

Publications and source records attributed to M Sampietro.

At least 91 records · Page 5Linked to original sources
PubMed1986

Feasibility of prenatal diagnosis of beta thalassaemia by DNA polymorphisms in an Italian population.

A feasibility study of prenatal diagnosis of beta thalassaemia in a northern Italian population has been carried out. Twenty-five families have been studied, each consisting of two parents and a homozygous beta thalassaemia child, thus enabling linkage analysis of restriction fragment length polymorphisms (RFLPs) to the normal and the thalassaemic chromosomes. Using seven standard RFLPs, 19/25 families could be offered prenatal diagnosis; inclusion of the recently described Ava II psi beta polymorphism increased this figure to 23/25 (92%) of the families.

Child↗
PubMed1986

Alpha thalassaemia in an Italian population.

The incidence of alpha-thalassaemia in an Italian population has been determined by a survey of random cord bloods for the presence of Hb Bart's. 144 out of 4730 (3%) had detectable amounts of Hb Bart's. Furthermore, alpha-globin gene analysis of 100 random cord bloods showed that five out of 100 had the common type of alpha-thalassaemia caused by a single alpha-globin gene deletion (-alpha). The molecular basis of alpha-thalassaemia was also determined in a selected group of 34 newborns with detectable levels of Hb Bart's. 25 of these cases had the -alpha 3.7 deletion type of alpha-thalassaemia and nine had nondeletion types of alpha-thalassaemia in four of which the molecular defect was detectable directly by restriction enzyme analysis.

Chromosome Deletion↗
PubMed1985

Feasibility of prenatal diagnosis of beta-thalassaemia with synthetic DNA probes in two Mediterranean populations.

A feasibility study in two Mediterranean populations showed that prenatal diagnosis of beta-thalassaemia with a limited number of synthetic oligonucleotide probes would have been possible in about 70% of cases. To provide a comprehensive programme of prenatal diagnosis for the thalassaemias it would be necessary, in most populations, to combine fetal DNA analysis with fetal blood sampling and globin-chain synthesis studies.

Autoradiography↗
PubMed1984

Erythrocyte ferritin in thalassemia syndromes.

Basic ferritin (liver-type) was measured in erythrocytes of subjects with alpha- and beta-thalassemia trait, thalassemia intermedia and Cooley's disease, and compared with normals and patients with abnormal iron metabolism without erythrocyte metabolic defect (iron deficiency anemia and idiopathic hemochromatosis). In all the thalassemic syndromes considered, erythrocyte ferritin was significantly higher than in normals (p less than 0.001) and increased progressively with the increasing 'severity' of the thalassemic disorder. In both thalassemic and non-thalassemic subjects, erythrocyte ferritin levels were related to body iron status, but in the thalassemic group, the increased erythrocyte ferritin values seemed also to be closely related to the intracellular metabolic abnormality. The severity of the defect in globin chain synthesis seemed to play an important role in determining ferritin accumulation in red cells of thalassemic subjects.

Adolescent↗
PubMed1981

Non-specific iron in patients with beta-thalassaemia trait and chronic active hepatitis.

A non-specific iron fraction, not bound to transferrin, has been looked for in the sera of 42 never-transfused patients with beta-thalassaemia trait, 17 of whom had chronic active hepatitis, negative for HBV infection or alcohol abuse. Non-specific iron was found only in the sera of those patients with beta-thalassaemia trait plus chronic active hepatitis who had complete transferrin saturation, high serum ferritin levels and urinary iron excretion and a high degree of hepatic siderosis. In view of the known toxicity of non-transferrin iron, we suggest that this non-transferrin iron fraction may be responsible for the liver damage in these patients. Furthermore, the positive correlation between the presence and the amount of non-transferrin iron and the levels of serum ferritin suggests that this fraction is a sensitive indicator of iron-induced toxicity when severe iron overload slowly develops in patients with beta-thalassaemia trait even in the absence of any iron administration.

Adult↗
PubMedDate not supplied

Mutations in the HFE gene and their interaction with exogenous risk factors in hepatocellular carcinoma.

The possible role of iron in facilitating the development of liver cancer is still debated. The aims of this study were to define the prevalence of the mutations 845G --> A and 187C --> G (C282Y and H63D) in the HFE gene associated with hereditary hemochromatosis in Italian patients with hepatocellular carcinoma occurring in cirrhosis and to analyze the interaction between these mutations and other established risk factors for hepatocellular carcinoma. The HFE gene mutations, performed by polymerase chain reaction, were analyzed in 81 patients (63 males, 18 females) with hepatocellular carcinoma. None of the patients had a phenotype compatible with homozygous hereditary hemochromatosis. Interaction between HFE mutations and exogenous risk factors was analyzed by collecting information on alcohol consumption, hepatitis B and C virus infections, and iron status at the time of diagnosis of chronic liver disease. This analysis was performed only in males to rule out gender influence on patients' iron status by using the case-only approach specifically designed to estimate departure from multiplicative risk ratios under the assumption of independence between genotype and environmental exposure. The prevalence of the C282Y mutation was significantly higher in patients with hepatocellular carcinoma than in normal controls (8.6% vs 1.6%, P < 0.03). At univariate analysis, iron overload was significantly associated with both HFE mutations (P < 0.0001), whereas ongoing hepatitis B virus infection was associated with the C282Y mutation (P < 0.05). By multivariate analysis, a trend for an increased risk of being positive for hepatitis virus markers (OR 2.9, CI 95% 0.9-9.5) and of having been alcohol abusers (OR 3, CI 95% 0.7-14) was observed in patients heterozygous for the HFE mutations. These data indicate that the prevalence of the main mutation associated with hereditary hemochromatosis is significantly higher in cirrhotic Italian patients with hepatocellular carcinoma compared to a normal population and suggest that heterozygotes for HFE mutations exposed to hepatitis virus infections or who had been alcohol abusers could have an increased risk of developing cirrhosis and later liver cancer than people without the mutations exposed to the same risk factors.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Iron status and HFE genotype in erythrocyte pyruvate kinase deficiency: study of Italian cases.

We evaluated the iron status and searched for mutations C282Y and H63D in the hereditary hemochromatosis gene (HFE) in 34 pyruvate kinase (PK)-deficient patients from 29 unrelated families. Nine had received multiple transfusions. Thirteen of the 25 nontransfused patients displayed increased serum ferritin concentration, in the absence of conditions known to raise this parameter. HFE genotype was abnormal in 9 of 34 patients. The allele frequency was 1.8% for mutation 845G--> (C282Y) and 16.1% for mutation 187C-->G (H63D). Nontransfused subjects with abnormal genotype had serum ferritin and transferrin saturation values significantly higher than those with wild-type genotype. Of the 12 adult nontransfused patients with increased iron status parameters, 1 was C282Y homozygous, 1 compound heterozygous for C282Y and H63D, 3 H63D heterozygous, and 7 had a normal HFE genotype. Serum ferritin and transferrin saturation were not related to hemoglobin, reticulocytes, and bilirubin concentration. At multivariate analysis serum ferritin was independently associated with age and gender, but not with splenectomy and HFE genotypes. The retrospective evaluation of the iron status profile of 10 patients (3 with abnormal and 7 with wild-type HFE genotype) with at least 10 years follow-up showed that overt iron accumulation requiring iron chelation had occurred only in the 3 patients (2 of whom were splenectomized) with the mutated HFE gene.

Adolescent↗
PubMedDate not supplied

Diagnosis of hemophilia A in a female subject by using restriction fragment length polymorphisms linked to the factor VIII gene.

A 6-year-old girl, daughter of a male patient with moderate hemophilia A (factor VIII 3%), was referred to our Center because she also had very low levels of factor VIII (4%). The proband's brother has mild hemophilia A (7%); the mother (29%) is a possible carrier, no other case of hemophilia A being reported in her family. Hence, the factor VIII deficiency found in the girl is consistent either with a carrier state with extreme lyonization in favour of the hemophilic gene or with homozygosity for the hemophilia gene. To distinguish these possibilities, we studied the segregation of three restriction fragment length polymorphisms (RFLPs) linked to the factor VIII gene in the 4 members of the family. Employing one intragenic (FVIII-BclI) and two extragenic (St14-TaqI and Dx13-BglII) RFLPs, we showed that the proband has inherited from both parents the defective gene, being therefore homozygous for the hemophilia gene.

Child↗
PubMedDate not supplied

Analysis of the genes for transferrin, transferrin receptor as well as H and L subunits of ferritin in idiopathic hemochromatosis.

In the attempt to define the abnormalities responsible for the severe iron overload found in patients with idiopathic hemochromatosis (IH) we analyzed, in 8 patients with IH and in 7 normal subjects, by using specific cDNA probes, the genes coding for the main iron-related proteins, i.e., transferrin, transferrin receptor, as well as H and L subunits of ferritin. In all the patients tested all the probes failed to evidentiate rearranged bands with any of the restriction enzymes employed. These findings suggest the absence of gross structural alterations of the genes examined. The lack of polymorphic sites recognized by the restriction enzymes employed in this study within or around the genes examined does not allow to associate a specific gene with the disease.

Adult↗
PubMedDate not supplied

The hemochromatosis gene affects the age of onset of sporadic Alzheimer's disease.

In the present study we analysed the genotype of HFE, the gene involved in hemochromatosis, in 107 patients with sporadic late-onset AD and in 99 age-matched non-demented controls. We observed that patients carrying the mutant HFE-H63D allele had a mean age at onset of 71.7 +/- 6.0 years versus 76.6 +/- 5.8 years of those who were homozygous for the wild-type allele (p = 0.001). The frequency of the HFE-H63D mutation was highest (0.22) in the patients aged <70 years at the time of disease onset, whereas it was 0.12 in those with disease onset at an age of 70-80 years, and 0.04 in those aged more than 80 years. The APOE genotype did not significantly modify the effect of HFE on age at onset. We conclude that mild disturbances of iron homeostasis associated with a common genetic determinant may interact with other pathogenic mechanisms involved in AD. HFE mutations may anticipate AD clinical presentation in susceptible individuals.

Age of Onset↗
PubMedDate not supplied

[New knowledge on endo-oral submandibular sialoadenectomy].

The present work reports personal modifications to the classical endo-oral surgical technique used to remove the submaxillary gland (Bourguet and Branchu surgery). The top of the tongue is transfixed with a silk thread and drawn out of the mouth laterally. An incision from the outlet of the Wharton duct to the base of the anterior palatine arch makes possible a full view of the sublingual extension of the submaxillary gland and the point where the lingual nerve crosses the Wharton duct. The sublingual gland may be removed to broaden access to the muscular hiatus of the mylohyoideus and hyoglossus muscles. The edges of the submaxillary gland are then identified and dissected from the muscle plane. At this point the sublingual extension of the submaxillary gland is detached from the lingual nerve which is medialized and shifted backward. The branches of the submental artery feeding the gland are isolated and pinched off so that the submaxillary gland can be removed from behind its anterior pole. Draining forward the gland can now be seen. At this point, if there is any adherence with the gland, a silk-catgut thread can be pulled back and forth as a saw in order separate the two. Once the glandular branch of the facial artery has been separated and detached from the gland, the submaxillary gland is fully removed. A small drainage is positioned in the surgical cavity sutured with Dexon thread and medicated with an external "Tensoplast" compress stretched from the jaw bone to the mastoid on the opposite side. The authors feel that the above surgical technique may prove advantageous and effective when a satisfactory esthetic result is required in benign submaxillary gland pathology.

Adult↗