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Biomedical subjects

P Izzo

Publications and source records attributed to P Izzo.

89 records · Page 5Linked to original sources
PubMedDate not supplied

Novel six-nucleotide deletion in the hepatic fructose-1,6-bisphosphate aldolase gene in a patient with hereditary fructose intolerance and enzyme structure-function implications.

Hereditary fructose intolerance (HFI) is an autosomal recessive human disease that results from the deficiency of the hepatic aldolase isoenzyme. Affected individuals will succumb to the disease unless it is readily diagnosed and fructose eliminated from the diet. Simple and non-invasive diagnosis is now possible by direct DNA analysis that scans for known and unknown mutations. Using a combination of several PCR-based methods (restriction enzyme digestion, allele specific oligonucleotide hybridisation, single strand conformation analysis and direct sequencing) we identified a novel six-nucleotide deletion in exon 6 of the aldolase B gene (delta 6ex6) that leads to the elimination of two amino acid residues (Leu182 and Val183) leaving the message inframe. The three-dimensional structural alterations induced in the enzyme by delta 6ex6 have been elucidated by molecular graphics analysis using the crystal structure of the rabbit muscle aldolase as reference model. These studies showed that the elimination of Leu182 and Val183 perturbs the correct orientation of adjacent catalytic residues such as Lys146 and Glu187.

Amino Acid Sequence↗
PubMedDate not supplied

Assessment of erythrocyte deformability with the laser-assisted optical rotational cell analyzer (LORCA).

The erythrocyte deformability of 28 patients with anemia was evaluated with the laser-assisted optical rotational cell analyzer (LORCA), an image analyzer that converts into numerical form the degree of refraction of a laser beam induced by red cells subjected to a range of torsional stresses. The patients were 10 thalassemics, including three with intermediate forms (1 HbC/beta degree, 1 homozygote beta for Orkin's haplotype VI, 1 beta degree/beta delta Sicilian type) and seven heteroygotes for beta Th; six with hereditary spherocytosis (including 2 with structural alteration of the spectrin beta chain); three with type II congenital dyserythropoietic anemia (HEMPAS), two hemizygotes and one heterozygote for G-6PD deficiency, and six with severe hypochromic hyposideremic anemia. Red cell deformability was reduced in intermediate thalassemia, hereditary spherocytosis and HEMPAS, normal in heterozygous beta thalassemia and G-6PD deficiency, and increased in hypochromic hyposideremic anemia. These results show that erythrocyte deformability can be impaired by an Hb chain imbalance, membrane and cyto skeleton structure anomalies and changes in the red cell area/volume ratio.

Adolescent↗
PubMedDate not supplied

[Familial colonic polyposis: effect of molecular analysis on the diagnostic-therapeutic approach].

Germline mutations of the Adenomatous polyposis gene (APC) are responsible for Familial Adenomatous Polyposis (FAP), an inherited condition that predisposes to the development of hundreds to thousands benign adenomas in the colo-rectum. If not surgically removed, they inevitably progress into malignant adenocarcinoma. To date more than 450 germline mutations have been described allowing the establishment of genotype/phenotype correlation between the site and type of molecular defects and their morbid consequences. Authors reviewed their experience concerning 22 FAP affected patients and their 26 first degree relatives, in whom the mutational analysis of the APC gene had been carried out. Site and type of mutations were associated with clinical parameters (age of onset, rectal involvement, extracolonic manifestations, presence of colorectal cancer) and treatments. The impact of mutational analyses on the clinical approach could be very interesting in the future, modifying both surveillance programs and therapeutical choices.

Adenomatous Polyposis Coli↗
PubMedDate not supplied

Human aldolase A gene: structural organization and expression in tumor cell lines.

The structural intron/exon organization of the cloned human aldolase A gene is reported. The gene is composed of twelve exons, including the coding and the 5' and 3' non-coding regions. Four mRNAs, different at the 5' non-coding region, are transcribed from this gene in a tissue-specific manner. The study of the expression of aldolase A gene in normal liver and neoplastic cell lines demonstrated the resurgence of foetal pattern of expression in all tumor liver cell lines and HeLa cells, thus supporting the foetalism theory for this gene system.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Four cases of XX males: endocrine and clinical features.

G-banded chromosome preparations from four phenotypically male patients resulted azoospermic at semen analysis, showed no evidence of Y chromosome in 46,XX female constitution. At the andrological examination, the only common finding in them was the presence of very small testes. Serum levels of basal LH, FSH, prolactin and testosterone were evaluated. A subnormal response by testicular Leydig cells to HCG was observed. The LH and FSH responses to LHRH were similar to those of XXY controls, and the variation of prolactin levels after sulpiride stimulus was in the normal range. Seminal, histological and endocrine investigations show the primitive origin of the hypogognadism.

Adult↗
PubMedDate not supplied

Congenital dyserythropoietic anemia type II: molecular basis and clinical aspects.

Congenital dyserythropoietic anemia of type II (CDA II) is a rare disorder, usually present in childhood, with a clinical picture of chronic anemia of mild to moderate degree, splenomegaly and intermittent or persistent jaundice. It is transmitted by autosomal recessive inheritance and is characterized by the presence of a large number of multinucleate and binucleate erythroblasts in the bone marrow and typical morphological abnormalities of the membrane of circulating erythrocytes. SDS-PAGE of red blood cell membrane proteins shows a narrower aspect and a faster migration of band 3 (anion exchange transporter). This aspect is consistent with decreased glycosylation of this protein. The genetic mutations responsible for the glycosylation defect in CDA II have not yet been identified. Analysis of carbohydrate structures and biochemical data indicate that the activity of either GnT II or alpha-Man II is reduced in different families, suggesting that the disease is genetically heterogeneous. Molecular cloning of the GnT II and alpha-Man II DNA sequences has allowed direct investigation of the genetic mutations underlying the glycosylation defect in CDA II patients to begin.

Anemia, Dyserythropoietic, Congenital↗
PubMedDate not supplied

CEA, TPA, CA 19-9, SCC and CYFRA at diagnosis and in the follow-up of anal canal tumors.

The authors evaluated serum CEA, TPA, CA19-9, SCC and CYFRA at diagnosis and in the follow-up of 18 anal canal tumors. Sensitivity at diagnosis was 38.8% for CEA, 55.5% for TPA, 16.6% for CA19-9, 50% for SCC and 5.5% for CYFRA. In the follow-up CEA showed 0% sensitivity and 73.3% specificity, TPA 33.3% sensitivity and 86.6% specificity, CA19-9 0% sensitivity and 80% specificity, SCC 0% sensitivity and 93.3% specificity, CYFRA 0% sensitivity and 100% specificity. The authors consider the usefulness of serum SCC and TPA at diagnosis of squamocellular anal cancer and of CEA in the diagnosis of cloacogenic tumors. Nevertheless these serum markers did not detect recurrences in the follow-up.

Aged↗
PubMedDate not supplied

[Level of immunosuppressive acidic protein in the fluid of breast cysts].

IAP marker was detected by radio-immunodiffusion in breast gross cyst fluid and in serum. No correlation was found between this antigen and cyst' cytological type, serum concentrations and acute phlogosis. In most cysts IAP was not valuable; on the other hand, high levels of glycoprotein were found only in the subgroup on relapsed class of apocrine cysts.

Adult↗