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Achille Iolascon

Publications and source records attributed to Achille Iolascon.

At least 37 records · Page 2Linked to original sources
PubMed2003

Caspase 3 and 8 deficiency in human neuroblastoma.

An altered apoptotic response represents a pivotal feature of cancer and is involved in cancerogenesis and resistance to chemotherapy. So far, however, only a few studies have been devoted to survey caspase content in malignant cell lines and primary tumor specimens. In this report, we investigated the expression of two pivotal caspases, 3 and 8, in 63 neuroblastoma specimens by three complementary techniques (i.e., reverse transcriptase polymerase chain reaction, immunoblotting, and immunohistochemistry). We confirmed the frequent absence of caspase 8 expression. Moreover and most important, we demonstrated, for the first time to our knowledge, that a significant percentage of neuroblastomas lack caspase 3 mRNA and protein. Both caspase alterations do not show any correlation with tumor stage and MYCN status. Immunohistochemistry showed a large number of caspase-negative cell islets also present in positive samples. Our findings suggest that the absence of caspases might play an important role in neuroblastoma development and resistance to apoptosis-based treatments.

Apoptosis↗
PubMed2003

The "stomatin" gene and protein in overhydrated hereditary stomatocytosis.

In overhydrated hereditary stomatocytosis (OHSt), Coomassie- and silver-stained polyacrylamide gels show an apparently complete deficit of the 32-kDa membrane protein, stomatin. We have used an antistomatin antibody to examine peripheral blood films, bone marrow, splenic tissue, and hepatic tissue from these patients by immunocytochemistry. This technique revealed that, in fact, some red cells did show positive stomatin immunoreactivity; and consistent with this result, Western blot analysis of the red cell membranes confirmed that about one twentieth to one fiftieth of the normal amount of stomatin was in fact present. Flow cytometry, combining immunoreactive quantitation of stomatin expression with thiazole orange staining for reticulocytes, showed that in OHSt, it was the young cells that had more stomatin. Magnetic-activated cell separation studies, using beads to which an anti-transferrin receptor antibody was conjugated, confirmed that in OHSt there was a correspondence between expression of stomatin and the transferrin receptor. Immunocytochemistry and Western blotting revealed that in OHSt patients, the protein was present in spleen, liver, neutrophils, platelets, monocytes, and about 50% of the peripheral lymphocytes, with the same distribution as in healthy controls. Neither Southern blots, nor direct sequencing of multiple subclones of the cDNA, nor sequencing of amplicons from genomic DNA revealed any significant abnormality in stomatin gene sequence in these patients. The deficiency of stomatin from red cells appears to be due to a loss of stomatin from these red cells on maturation in the bone marrow and in the circulation.

Anemia, Hemolytic↗
PubMed2003

Influence of ursodeoxycholate-enriched diet on liver tumor growth in HBV transgenic mice.

Hepatitis B virus (HBV) transgenic mice (official designation, Tg [Alb-1 HBV] Bri 44) invariably develop macroscopically evident tumors within the 20th month of life. Sustained proliferative activity seems to play an important role in the development of these lesions. We previously showed that ursodeoxycholate (UDC) stimulates hepatocyte proliferation in various experimental settings. Herein, we tested the assumption that biological factors able to further increase liver cell proliferation, such as UDC, could accelerate tumor development in this animal model. For this study, 22 eight-week-old male transgenic mice were divided into 2 groups; 11 animals received a standard diet, and 11 received a UDC-enriched diet. The 2 groups were further divided into 2 subgroups of 5 and 6 animals each and were sacrificed at 3 and 15 months of age, respectively. These different times were chosen to exclude diet-related toxicity (in 3-month-old mice) and evaluate tumor growth (in 15-month-old mice). In addition, hepatocyte proliferation was assessed in all animals. In 3-month-old mice receiving UDC, cholestatic and cytolytic indices as well as liver histology were comparable to those in controls. At 15 months, all UDC-treated mice showed large multinodular tumors whereas only 33% of controls developed smaller uninodular neoplasms. Hepatocyte proliferation was increased in all animals receiving UDC compared with controls. In conclusion, the increase in serum UDC (undetectable in mice fed a standard diet), in the absence of any toxic effect on the liver, suggests the involvement of this bile salt in the stimulation of hepatocyte proliferation and tumor growth.

Adenoma, Liver Cell↗
PubMed2003

MYH9-related disease: May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but represent a variable expression of a single illness.

May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are autosomal dominant macrothrombocytopenias distinguished by different combinations of clinical and laboratory signs, such as sensorineural hearing loss, cataract, nephritis, and polymorphonuclear Döhle-like bodies. Mutations in the MYH9 gene encoding for the nonmuscle myosin heavy chain IIA (NMMHC-IIA) have been identified in all these syndromes. To understand the role of the MYH9 mutations, we report the molecular defects in 12 new cases, which together with our previous works represent a cohort of 19 families. Since no genotype-phenotype correlation was established, we performed an accurate clinical and biochemical re-evaluation of patients. In addition to macrothrombocytopenia, an abnormal distribution of NMMHC-IIA within leukocytes was observed in all individuals, including those without Döhle-like bodies. Selective, high-tone hearing deficiency and cataract was diagnosed in 83% and 23%, respectively, of patients initially referred as having May-Hegglin anomaly or Sebastian syndrome. Kidney abnormalities, such as hematuria and proteinuria, affected not only patients referred as Fechtner syndrome and Epstein syndrome but also those referred as May-Hegglin anomaly and Sebastian syndrome. These findings allowed us to conclude that May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but rather a single disorder with a continuous clinical spectrum varying from mild macrothrombocytopenia with leukocyte inclusions to a severe form complicated by hearing loss, cataracts, and renal failure. For this new nosologic entity, we propose the term "MHY9-related disease," which better interprets the recent knowledge in this field and identifies all patients at risk of developing renal, hearing, or visual defects.

Adolescent↗
PubMed2003

Inherited thrombocytopenias: a proposed diagnostic algorithm from the Italian Gruppo di Studio delle Piastrine.

BACKGROUND: Although no epidemiological study has so far been performed, inherited thrombocytopenias are considered to be very rare based on the number of case reports in the literature. However, diagnosis of these disorders is often difficult and requires competences that are limited to specialized centers. We, therefore, suspect that inherited thrombocytopenias are underreported because their diagnosis is often missed. OBJECTIVES: The aim of this study was to develop a diagnostic algorithm that utilizes the simplest possible diagnostic tests and that can also be used in centers that are not highly specialized. METHODS: The basic features of the diagnostic algorithm (definition and classification of hereditary thrombocytopenias, laboratory tests, sequence of investigations) were discussed by the members of the Italian Gruppo di Studio delle Piastrine during two meetings held in October 2000 and 2001. The sources of information were literature and personal experience. The final proposed diagnostic algorithm was produced by the authors of this paper and approved during a third meeting in May 2002. PERSPECTIVES: A definite diagnosis for patients with hereditary thrombocytopenias serves many purposes. It is essential to define the prognosis of the patients and to identify the best therapeutic approach. It also defines the risk of transmitting the disorder to progeny and, in many cases, allows prenatal diagnosis. Finally, several pieces of evidence indicate that not all the genetic thrombocytopenias have yet been identified. Exclusion of known disorders by accurate investigation is, therefore, the starting point for the discovery of these new illnesses.

Algorithms↗
PubMed2003

Red blood cell membrane defects.

We present an overview of the currently known molecular basis of red cell membrane disorders. A detailed discussion of the structure of the red cell membrane and the pathophysiology and clinical aspects of its disorders is reported. Generally speaking, hereditary spherocytosis (HS) results from a loss of erythrocyte surface area. The mutations of most cases of HS are located in the following genes: ANK1, SPTB, SLC4A1, EPB42 and SPTA1, which encode for ankyrin, spectrin beta-chain, the anion exchanger 1 (band 3), protein 4.2 and spectrin alpha-chain, respectively. Hereditary elliptocytosis (HE) reflects a diminished elasticity of the skeleton. Its aggravated form, hereditary pyropoikilocytosis (HPP), implies that the skeleton undergoes further destabilization. The mutations responsible for HE and HPP, lie in the SPTA1 and SPTB gene, and in the EPB41 gene encoding protein 4.1. Allele alpha LELY is a common polymorphic allele, which plays the role of an aggravating factor when it occurs in trans of an elliptocytogenic allele of the SPTA1 gene. Southeast Asian ovalocytosis derives from a change in band 3. The genetic disorders of membrane permeability to monovalent cations required a positional cloning approach. In this respect, channelopathies represent a new frontier in the field. Dehydrated hereditary stomatocytosis (DHS) was shown to belong to a pleiotropic syndrome: DHS + fetal edema + pseudohyperkalemia, which maps 16q23-24. Splenectomy is strictly contraindicated in DHS and another disease of the same class, overhydrated hereditary stomatocytosis, because it increases the risk of thromboembolic accidents.

Adult↗
PubMed2002

Congenital dyserythropoietic anemia type I is caused by mutations in codanin-1.

Congenital dyserythropoietic anemias (CDAs) constitute a rare group of inherited red-blood-cell disorders associated with dysplastic changes in late erythroid precursors. CDA type I (CDAI [MIM 224120], gene symbol CDAN1) is characterized by erythroid pathological features such as internuclear chromatin bridges, spongy heterochromatin, and invagination of the nuclear membrane, carrying cytoplasmic organelles into the nucleus. A cluster of 45 highly inbred Israeli Bedouin with CDAI enabled the mapping of the CDAN1 disease gene to a 2-Mb interval, now refined to 1.2 Mb, containing 15 candidate genes on human chromosome 15q15 (Tamary et al. 1998). After the characterization and exclusion of 13 of these genes, we identified the CDAN1 gene through 12 different mutations in 9 families with CDAI. This 28-exon gene, which is transcribed ubiquitously into 4738 nt mRNA, was reconstructed on the basis of gene prediction and homology searches. It encodes codanin-1, a putative o-glycosylated protein of 1,226 amino acids, with no obvious transmembrane domains. Codanin-1 has a 150-residue amino-terminal domain with sequence similarity to collagens and two shorter segments that show weak similarities to the microtubule-associated proteins, MAP1B (neuraxin) and synapsin. These findings, and the cellular phenotype, suggest that codanin-1 may be involved in nuclear envelope integrity, conceivably related to microtubule attachments. The specific mechanisms by which codanin-1 underlies normal erythropoiesis remain to be elucidated.

Amino Acid Sequence↗
PubMed2002

Splenectomy prolongs in vivo survival of erythrocytes differently in spectrin/ankyrin- and band 3-deficient hereditary spherocytosis.

Red cell (RBC) deformability and membrane-bound immunoglobulin G (IgG) were studied to better understand premature clearance of erythrocytes in hereditary spherocytosis. Averaged deformability profiles from cells having comparable cell age revealed that splenectomy was more beneficial for spectrin/ankyrin-deficient than for band 3-deficient RBCs. Splenectomy prevented an early loss of young cells in both types of deficiencies. It had an additional beneficial effect on spectrin/ankyrin-deficient but not band 3-deficient RBCs. It prolonged the survival of mature spectrin/ankyrin-deficient RBCs such that they lost their deformability more slowly than RBCs from patients who had not undergone splenectomy. Band 3-deficient RBCs lost their deformability at the same rate before and after splenectomy. In HS patients with band 3 deficiency who underwent splenectomy, RBC deformability inversely correlated with the number of RBC-bound IgG (up to 140 molecules per cell). In spectrin/ankyrin deficiency, RBC-bound IgG remained at control levels (60 IgG or less per cell). It appears that spectrin/ankyrin-deficient RBCs escaped opsonization by releasing band 3-containing vesicles because their band 3 content and deformability dropped in parallel with increasing cell age. Band 3-deficient RBCs did not lose band 3 with increasing cell age. Hence, it is possible that band 3 clusters required for bivalent binding of low-affinity-IgG, naturally occurring antibodies were retained in band 3-deficient RBCs with a relative excess of skeletal proteins but were released from spectrin/ankyrin-deficient RBCs, in which vesicle budding was facilitated by an impaired skeleton.

Anion Exchange Protein 1, Erythrocyte↗
PubMed2002

Infant hypervitaminosis A causes severe anemia and thrombocytopenia: evidence of a retinol-dependent bone marrow cell growth inhibition.

Vitamin A is a pivotal biochemical factor required for normal proliferation and differentiation as well as for specialized functions, such as vision. The dietary intake of 1500 IU/day is recommended in the first year of life. Here, we report the case of an infant who had been given 62 000 IU/day for 80 days. The infant showed several clinical signs of retinol intoxication, including severe anemia and thrombocytopenia. Bone marrow showed a remarkably reduced number of erythroid and megakaryocytic cells. The interruption of vitamin A treatment was immediately followed by clinical and biochemical recovery. To clarify whether the effects of retinol are due to a direct action on bone marrow cell proliferation, we investigated the activity of retinol (both the drug and the pure molecule) on the growth of K-562, a multipotent hematopoietic cell line, and on bone marrow mesenchymal stem cells. We observed that vitamin A strongly inhibited the proliferation of the cells at concentrations similar to those reached in vivo. Subsequent biochemical analyses of the cell cycle suggested that the effect was mediated by the up-regulation of cyclin-dependent kinase inhibitors, p21(Cip1) and p27(Kip1). These are the first findings to demonstrate that infant hypervitaminosis A causes a severe anemia and thrombocytopenia and that this is probably due to the direct effect of the molecule on the growth of all bone marrow cellular components. Our data also suggest potential bone marrow functional alterations after excessive vitamin A intake because of emerging social habits.

Anemia↗
PubMed2002

Two regions of deletion in 9p22- p24 in neuroblastoma are frequently observed in favorable tumors.

Neuroblastoma is a tumor of infancy that presents several chromosomal abnormalities. Nonrandom deletion of chromosome arm 9p has been identified in primary neuroblastoma suggesting the presence of a tumor suppressor gene located on this chromosome. In previous work, we showed that CDKN2A and CDKN2B genes, mapped at 9p21, were not deleted in neuroblastoma cells. In the present article, we refine the deleted region of 9p using polymerase chain reaction-based analysis of highly polymorphic simple sequence repeats and a two color fluorescence in situ hybridization technique on interphase nuclei. We analyzed 71 primary tumors of patients at the onset of the disease. We found loss of heterozygosity (LOH) in 16 of 71 (23%) cases; the frequency of LOH for 9p was higher (28%) in favorable stages 1, 2, and 4s than in unfavorable stages 3 and 4 (14%). Our results identify two regions of frequent allelic loss: the first at the locus D9S1849 and the second at the locus D9S157. These regions appear to be distant from CDKN2A and CDKN2B loci suggesting that other genes may be involved in 9p deletion. Finally, our data show that 9p deletion is more frequent in tumors of patients with a favorable prognosis, indicating that deleted genes may not be crucial for tumor progression.

Alleles↗
PubMed2002

Neonatal hyperbilirubinemia and Gilbert's syndrome.

The role of Gilbert's syndrome (GS) in neonatal hyperbilirubinemia, characterized by bilirubin levels higher than 223 microMol/L during the first seven days of life, has been investigated, evaluating the frequency of GS genotype (A(TA)7TAA polymorphism in the promoter of the gene encoding UGT1). The frequency of GS was significantly higher in the hyperbilirubinemic group, even though neither the peak of bilirubin, nor the day on which the highest value was found, differed according to genotype. The normalization of bilirubin levels was slower in neonates with GS. These results confirm the idea that GS is one of the factors contributing to neonatal hyperbilirubinemia, but that other factors play a role in determining neonatal jaundice. The slower decrease of bilirubin levels in A(TA)7TAA homozygous neonates confirms that GS is an important factor in determining a prolonged neonatal jaundice.

Bilirubin↗
PubMed2002

Proliferate and survive: cell division cycle and apoptosis in human neuroblastoma.

BACKGROUND AND OBJECTIVES: Neuroblastoma is one of the most frequent childhood cancers and a major cause of death from neoplasias of infancy. Although a wealth of studies on its molecular bases have been carried out, little conclusive information about its origin and evolution is available. EVIDENCE AND INFORMATION SOURCES: Some intriguing findings have correlated neuroblastoma development with aberrations of two pivotal cellular processes generally altered in human cancers, namely cell division cycle and apoptosis. Indeed, it has been reported that neuroblastoma cell lines show accumulation of Id2 protein, a factor which is able to hamper the pRb protein antiproliferative activity. STATE OF THE ART: The increased Id2 is due to N-myc gene amplification and overexpression, a phenomenon frequently observed in neuroblastoma and an important independent negative marker. Moreover, neuroblastoma cells are frequently characterized by increased levels of survivin, an inhibitor of the apoptotic response, and by a deficiency of procaspase 8, a key intermediate of the programmed cell death cascade. These two events, probably, make neuroblastomas more resistant to programmed cell death. These recent findings might suggest that neuroblastoma cells have acquired the capability to proliferate easily and die difficultly. PERSPECTIVES: The mechanistic meaning of these data will be discussed in the present review. Moreover, we will suggest new therapeutic scenarios opened up by the described alterations of cell cycle and apoptosis engines.

Animals↗
PubMed2002

Inherited thrombocytopenias: from genes to therapy.

BACKGROUND AND OBJECTIVES: Inherited thrombocytopenias are a heterogeneous group of rare diseases characterized by a reduced number of blood platelets. Some of these diseases are exclusive to megakaryocytes and platelets, while in others the pathology extends to other cell types. Although the defective genes, coding for membrane glyoproteins, cytoskeleton components and intracellular signaling pathways, as well as transcription factors, have been identified in most cases, the pathophysiology of these disorders is often unknown. This review describes recent contributions to clinical and diagnostic aspects, biology and treatments of familial thrombocytopenias. EVIDENCE AND INFORMATION SOURCES: The information presented here derives from literature and the experience of the authors. The most relevant studies are critically analyzed and discussed. STATE OF ART: The clinical and laboratory features of most of the inherited thrombocytopenias have been reviewed. The different forms have been classified into 3 groups depending on platelet volume. Although this criterion is not completely satisfactory, it is one of the most useful in diagnostic algorithms. We report on recent advances in Wiskott-Aldrich and Bernard-Soulier syndromes, as well as in MYH9-related diseases, a new nosological entity that groups old distinct forms known as May-Hegglin anomaly, Sebastian, Fetchner, and Epstein syndromes. Other, less frequent forms are also discussed, including non-syndromic forms of mild thrombocytopenia that are genetically heterogeneous. PERSPECTIVES: In the past, inherited thrombocytopenias were considered exceedingly rare and the number of well-defined forms was very small. In the last few years, the widespread diffusion of electronic cell counters has allowed these conditions to be detected more frequently and several new entities have been identified through the co-ordinated efforts of physicians, biologists and geneticists. The pathogenesis of many new and old forms is being unraveled, thus providing insights on the molecular basis of platelet production and function. This knowledge will be a valuable resource for clinicians in the diagnostic approaches to such disorders.

Abnormalities, Multiple↗
PubMedDate not supplied

Congenital dyserythropoietic anemia type II: exclusion of seven candidate genes.

Congenital dyserythropoietic anemias (CDA) are genetic disorders characterized by anemia and ineffective erythropoiesis. Three main types of CDA have been distinguished: CDA I, CDAII and CDA III, whose loci have been already mapped. After the identification of the locus for CDA II, also known as HEMPAS (hereditary erythroblast multinuclearity with positive acidified serum test), on the long arm of chromosome 20 (20q11.2) we have analyzed by a mutational search seven candidate genes in a large series of CDA II patients. In particular, the following genes have been investigated: integrin beta 4 binding protein, ribophorin II, ubiquitin protein ligase ITCH, mannosil-oligosaccharide alpha-1,2-mannosidase like protein, erythrocyte protein band 4.1 like protein, zinc finger protein PLAGL2, and finally novel zinc finger protein. None of them resulted as the causative gene but several protein variants and DNA polymorphisms have been identified. These data exclude the role of the above mentioned genes in causing CDA II and add further information in the process of cloning the CDA II gene.

Anemia, Dyserythropoietic, Congenital↗
PubMedDate not supplied

Spina bifida and folate-related genes: a study of gene-gene interactions.

PURPOSE: To assess whether interactions of common alleles of two folate genes contribute to spina bifida risk. METHODS: Case-control study, comparing 203 children with spina bifida to 583 controls. RESULTS: Homozygosity for the 677C-T allele of 5,10-methylenetetrahydrofolate reductase (MTHFR) alone was associated with an odds ratio for spina bifida of 1.57 (95% confidence interval [CI], 1.02-2.38). For the 844ins68 allele of cystathionine-beta-synthase alone, the odds ratio was 0.83 (95% CI, 0.39-1.64). For the joint genotype, the odds ratio was 3.69 (95% CI, 1.04-13.50). CONCLUSIONS: Interactions between common alleles of folate genes might contribute to the risk for spina bifida.

Alleles↗