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Biomedical subjects

A Maggio

Publications and source records attributed to A Maggio.

At least 37 records · Page 2Linked to original sources
PubMed1998

Oxidation resistance of LDL is correlated with vitamin E status in beta-thalassemia intermedia.

The alteration of the oxidant/antioxidant balance may affect the susceptibility of low density lipoproteins (LDL) to oxidation in haemolytic disorders such as thalassemia. Thirty patients affected by beta-thalassemia intermedia were examined, and compared with age-matched healthy controls. The mean amount of vitamin E in the thalassemic LDL was lower than control (p < 0.0001), either when it was calculated on the base of LDL protein (61% decrease) or cholesterol (25% decrease). The LDL resistance to Cu2+-induced oxidation, evaluated as the length of the lag phase before the onset of conjugated diene (CD) lipid hydroperoxide production, was 20% lower than control. Other parameters of LDL susceptibility to oxidation, such as the rate of lipid peroxidation, Rp, and the total amount of conjugated dienes produced, CDmax, were only slightly lower than control, which can be explained by a lower content of peroxidable lipids in the thalassemic LDL. Total LDL cholesterol was 1.08 x 10(3) and 2.07 x 10(3) mol/mol LDL in thalassemic and in control LDL, respectively. The length of the lag phase in thalassemic LDL shows a strongly positive correlation with its vitamin E content (r = 0.732; p < 0.0001). The r2-value of 0.53 provides evidence that more than 50% of the lag phase is determined by vitamin E. Oxidizability of LDL lipids may explain 22-24% of the lag phase, as calculated by the inverse correlation between the length of the lag phase and CDmax (r = -0.474; p = 0.008; r2 = 0.22) and Rp (r = -0.499; p = 0.005; r2 = 0.24). In multiple regression analysis, the lag phase was predictable to 66% by vitamin E plus CDmax, and to 60% by vitamin E plus Rp. Plasma vitamin E was 53% lower in thalassemia patients compared to control and positively correlated with vitamin E in the LDL (r = 0.677; p < 0.0001). None of the correlations above were observed in control subjects. In conclusion, beta-thalassemia is associated with very low levels of vitamin E in plasma and in LDL, a condition that renders these particles more susceptible to in vitro oxidative modification and may account for atherogenesis-related vascular diseases described in thalassemia. The present data on a statistically significant correlation between abnormally low vitamin E and oxidizability of LDL contribute substantially to the hypothesis that vitamin E is a pathophysiologically important determinant of antioxidative protection of LDL.

Adult↗
PubMed1998

Gel permeation chromatography (GPC) of repeatedly extruded polyethylene terephthalate (PET).

The paper deals with gel permeation chromatography (GPC) monitoring of the behaviour of PET (polyethylene terephthalate) after repeated extrusions. Virgin PET was submitted to three successive extrusion/drying cycles and then the samples were swelled with hexafluoroisopropanol and treated with chloroform. GPC analysis was carried out at room temperature on a B.C.S. Serial LC 2000 GPC system equipped with a series of four GPC columns with UV detection at 254 nm and chloroform as eluent. GPC results showed that after each extrusion step the molecular weight distribution of the PET was different and Mw, Mn and Mz decreased. These findings suggest that during each extrusion degradation occurs and that repeated extrusions, as in the case of the recycling PET, may cause an alteration of the molecular weight distribution of the original PET.

Chromatography, Gel↗
PubMed1998

Attitude of potential users in Sicily towards preimplantation genetic diagnosis for beta-thalassaemia and aneuploidies.

This study aims to report the willingness of different populations of high-risk couples to undergo preimplantation genetic diagnosis (PGD) for beta-thalassaemia as an alternative to prenatal genetic diagnosis (PND), and the willingness of infertile couples to undergo PGD for aneuploidies. An information sheet and questionnaire presenting PGD and PND procedures were distributed to four population types: 54 high-risk couples for beta-thalassaemia coming for their first PND (population A); 51 similar couples coming for their second or further PND without previous experience of therapeutic abortion (population B-na); 50 similar couples coming for their second or further PND with previous experience of therapeutic abortion for beta-thalassaemia-affected fetus (population B-ab); and 74 infertile couples undergoing routine in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (population C). Favourable first impressions towards PGD compared with PND were observed in all four populations in the following proportions: 79.6% population A; 76.5% population B-na; 92.0% population B-ab; and 96.0% population C. Willingness to undergo PGD for beta-thalassaemia was as follows: 44.4% population A; 47.1% population B-na; and 72.0% population B-ab. We conclude that previous experience of PND for beta-thalassaemia is a crucial point in the willingness to accept the PGD procedure, and that couples belonging to population B-ab are the most suitable to undergo PGD for beta-thalassaemia. Some 96.0% of infertile couples in population C were ready to undergo PGD for aneuploidies.

Abortion, Therapeutic↗
PubMed1998

Comparative analysis of the regulation of expression and structures of two evolutionarily divergent genes for Delta1-pyrroline-5-carboxylate synthetase from tomato.

We isolated two tomato (Lycopersicon esculentum) cDNA clones, tomPRO1 and tomPRO2, specifying Delta1-pyrroline-5-carboxylate synthetase (P5CS), the first enzyme of proline (Pro) biosynthesis. tomPRO1 is unusual because it resembles prokaryotic polycistronic operons (M.G. García-Ríos, T. Fujita, P.C. LaRosa, R.D. Locy, J.M. Clithero, R.A. Bressan, L.N. Csonka [1997] Proc Natl Acad Sci USA 94: 8249-8254), whereas tomPRO2 encodes a full-length P5CS. We analyzed the accumulation of Pro and the tomPRO1 and tomPRO2 messages in response to NaCl stress and developmental signals. Treatment with 200 mM NaCl resulted in a >60-fold increase in Pro levels in roots and leaves. However, there was a <3-fold increase in the accumulation of the tomPRO2 message and no detectable induction in the level of the tomPRO1 message in response to NaCl stress. Although pollen contained approximately 100-fold higher levels of Pro than other plant tissues, there was no detectable increase in the level of either message in pollen. We conclude that transcriptional regulation of these genes for P5CS is probably not important for the osmotic or pollen-specific regulation of Pro synthesis in tomato. Using restriction fragment-length polymorphism mapping, we determined the locations of tomPRO1 and tomPRO2 loci in the tomato nuclear genome. Sequence comparison suggested that tomPRO1 is similar to prokaryotic P5CS loci, whereas tomPRO2 is closely related to other eukaryotic P5CS genes.

1-Pyrroline-5-Carboxylate Dehydrogenase↗
PubMed1997

Long-term efficacy of alpha-interferon in beta-thalassemics with chronic hepatitis C.

Hepatitis C virus (HCV) infection is a common cause of liver disease among polytransfused thalassemics. We treated a cohort of subjects with beta-thalassemia major and chronic hepatitis C with alpha-interferon. The aims of the study were to assess the long-term biochemical and virologic efficacy of alpha-interferon and to evaluate the influence of HCV type and liver siderosis on the outcome of therapy. Seventy subjects (mean age, 14.1 years) with chronic HCV infection and abnormal aminotransferases received recombinant alpha-interferon for 12 months and were observed after therapy for at least 24 months. Sixty-three subjects (90%) were HCV-RNA positive at the start of therapy. HCV type 1b was found in 41 subjects (65.1%), non-1b types in 13 (20.6%), and mixed HCV types in 9 (14.3%). Liver biopsy showed cirrhosis in 11 subjects (15.7%) and siderosis grade 3-4 in 24 patients (34.2%). Three patients stopped therapy due to adverse events. Twenty-eight subjects (40%) had normal aminotransferases and had cleared HCV-RNA when last observed (mean follow-up, 36.5 months; range, 25 to 49 months). Of 41 patients who did not normalize aminotransferases, 9 had become HCV-RNA negative at the end of follow-up. The absence of cirrhosis, low liver iron content, and infection with non-1b HCV type were independently associated to complete sustained response upon multivariable analysis. In conclusion, alpha-interferon may induce a sustained virologic and biochemical remission of hepatitis in beta-thalassemic patients with chronic HCV infection and nonadvanced liver disease.

Adolescent↗
PubMed1997

Tissue-specific activation of the osmotin gene by ABA, C2H4 and NaCl involves the same promoter region.

The gene encoding the antifungal protein osmotin is induced by several hormonal and environmental signals. In this study, tissue-specific and inducer-mediated expression of the reporter gene beta-glucuronidase (uidA) fused to different fragment lengths of the osmotin promoter was evaluated in transgenic tobacco (Nicotiana tabacum). The region of the promoter between -248 to -108 (Fragment A) was found to be essential and sufficient for inducer (abscisic acid (ABA), C2H4 and NaCl)-mediated expression of the reporter gene. Expression of the reporter gene was developmentally regulated and increased with maturity of leaves, stem and flowers. Expression also was tissue-specific being most highly expressed in epidermis and vascular parenchyma of the stem. The regulators ABA, C2H4 and NaCl exhibited tissue-specific induction of this promoter. The promoter was specifically responsive to C2H4 in flowers at virtually all stages of development, but not responsive in these tissues to ABA or NaCl. Conversely, ABA and NaCl were able to induce reporter gene activity using promoter Fragment A in specific tissues of root where C2H4 was unable to induce activity. Further dissection of the promoter Fragment A into fragments containing either the conserved GCC element (PR); PR/AT; or G/AT sequences, and subsequent testing of these fragments fused to GUS in transgenic plants was performed. These experiments revealed that the promoter fragment containing PR element alone, although required, was barely able to allow responsiveness to C2H4. However, significant C2H4-induced activity was obtained with a promoter fragment containing the AT and PR elements together.

Abscisic Acid↗
PubMed1997

Clinical and hematological response to hydroxyurea in a patient with Hb Lepore/beta-thalassemia.

The possibility of increasing Hb F in vivo using drugs like 5-azacytidine, hydroxyurea, and butyrate has been established. However, in many cases this does not entail an increase in total hemoglobin. We report on a patient with Hb Lepore/beta-thalassemia being treated with hydroxyurea (30 mg/Kg/day) because of the presence of erythroid extramedullary masses with severe neurological abnormalities. During therapy the patient showed a remarkable improvement in neurological signs due to the reduction in extra-medullary masses, a significant increase in both total hemoglobin (from 5.8 to 9.7 g/dl) and Hb F (from 4.9 g/dl to 9.1 g/dl). The marked improvement in hemoglobin level in our patient with Hb Lepore/beta-thalassemia suggests gamma-globin gene activation due to the DNA structure determined by the crossover event.

Adult↗
PubMed1996

Oxidative stress and antioxidant status in beta-thalassemia major: iron overload and depletion of lipid-soluble antioxidants.

Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of high tissue iron levels. Marked changes in the antioxidant pattern were also observed in all patients. Evidence is presented of a net drop in the concentration of ascorbate (-44%), vitamin E (-42%), vitamin A(-44%), beta-carotene (-29%), and lycopene (-67%). On the other hand, an increase of uric acid and bilirubin was observed, whereas serum albumin and glutathione were in the normal range in all patients. As a result, the total serum antioxidant potential, measured as trolox equivalent antioxidant capacity appeared significantly decreased by 14%. Serum levels of vitamin E were inversely correlated with ferritin (r = -.45; P = .003), suggesting a major consumption of this antioxidant under iron overload. Nontransferrin bound iron (NTBI) was in the range 4.5 to 54.8 micrograms/dL (mean, 21.8 +/- 13.9). Although NTBI had a positive trend with ferritin (r = .37, P = .03), no clear correlation was found with either MDA or vitamin E. A mild to severe hepatic damage, as assessed by serum transaminases, was shown in 24 of 42 patients. Serum levels of vitamin E (r = -.49, P = .015), vitamin A (r = -.48, P = .016) and lycopene (r = -.47, P = .020), were inversely correlated with the levels of transminases. On the other hand, lipid-soluble antioxidants in thalassemia patients were depleted to the same extent in hepatitis C virus (HCV)-infected (31 subjects) and in HCV-uninfected (10 subjects), while in the normal range in serum from 30 nonthalassemic patients with HCV-related chronic hepatitis. These results point out that the iron-induced liver damage in thalassemia may play a major role in the depletion of lipid-soluble antioxidants. The variations of the parameters evaluated in the present study were not correlated with the age of the patients. Our results suggest that the measurement of peroxidation products, matched with evaluation of antioxidants, may be a simple measure of iron toxicity in thalessemia, in addition to the conventional indices of iron status.

Adolescent↗
PubMed1996

Aminoethylcysteine ketimine decarboxylated dimer detected in normal human urine by gas-liquid chromatography, selected-ion monitoring and mass spectrometry.

Aminoethylcysteine ketimine is a biochemical product known to be converted spontaneously in the decarboxylated dimer. Since the ketimine has been detected in a mammalian brain, it was assumed that also the dimer could be present in the mammalian body and eventually excreted in the urine. Using human urine as the biological source, an extract was prepared which, submitted to gas-liquid chromatography, selected-ion monitoring and mass spectrometry, indicated the presence of the dimer.

Adult↗
PubMed1996

Lack of evidence of permanent engraftment after in utero fetal stem cell transplantation in congenital hemoglobinopathies.

The use of fetal hematopoietic stem cells for in utero transplantation to create permanent hematochimerism represents a new concept in fetal therapy. In one fetus with alpha-thalassemia, one with sickle cell anemia, and one with beta-thalassemia, we have transplanted fetal liver cells obtained from legal abortions in gestational weeks 6-11. The fetus with alpha-thalassemia was transplanted twice during pregnancy, in the 15th (20.4 x 10(8) cells/kg) and in the 31st weeks of gestation (1.2 x 10(8) cells/kg), and is now two years of age. One fetus with sickle cell anemia received its transplant in the 13th week of gestation (16.7 x 10(8) cells/kg), and is now one year old. The fetus with beta-thalassemia was transplanted in 18th week (8.6 x 10(8) cells/kg), and is now three months old. Engraftment was evaluated by chromosomal analysis (sex chromosomes), red cell phenotyping, HLA class I and II typing, and PCR (polymerase chain reaction) for Y chromosome-specific sequences and DNA polymorphisms in cord and peripheral blood. The children with alpha- and beta-thalassemia underwent bone marrow aspirations at 3 and 7 months of age, respectively. In neither of these cases were we able to detect convincing evidence of stem cell engraftment. Thus, the administration of fetal stem cells to fetal recipients after the 12th week of gestation did not result in permanent hematochimerism. It remains to be determined whether the engraftment process can be promoted by earlier transplantations and/or higher cell doses.

Adult↗
PubMed1996

An element upstream from the human delta-globin-encoding gene specifically enhances beta-globin reporter gene expression in murine erythroleukemia cells.

We have previously shown that a DNA-binding factor specific to adult hematopoietic cells (polypryrimidine-binding factor, PYBF) binds to a pyrimidine-rich region 1 kb upstream from the human delta-globin-encoding gene (HBD). The developmental stage-specificity of PYBF and the location of its binding site between the fetal and adult beta-globin (HBB)-like genes suggest that PBYF and its binding site may function in fetal-to-adult globin gene switching. Here, we describe the effect of 383-bp (delta383) and 99-bp (delta99) sequences containing the PYBF-binding site on transcription from various globin and non-globin promoters, using a transient assay with the cat reporter gene in murine erythroleukemia (MEL) cells, a cell line with abundant PYBF activity. We show that both delta383 and delta99 specifically enhance expression of cat for plasmids containing a human adult globin (HBB) promoter, whereas expression of similar constructs using human fetal (A gamma-) globin (HBG1) or simian virus 40 (SV40) promoters is not enhanced. The results suggest that PYBF and the pyrimidine-rich region upstream from HBD can specifically enhance HBB transcription in adult erythroid cells.

Adult↗
PubMed1996

Evidence of induced non-tolerance in HLA-identical twins with hemoglobinopathy after in utero fetal transplantation.

Fetus-to-fetus transplantation has been suggested for the treatment of hemoglobinopathies in utero. However, dissimilar results have to date been obtained by different groups. We describe a case in which fetus-to-fetus transplantation in HLA-identical twins was performed at the 19th week of gestation by infusion of 0.8 ml of fetal blood from normal to beta-thalassemia affected fetus with the main aim of inducing tolerance. No evidence of engraftment, determined by KM19 polymorphism, was present after 2 years of the procedure. Moreover, an alloreactive cytotoxic T lymphocyte precursor (CTLp) study of affected fetus vs donor and other different stimulators showed that immunization vs tolerance was the real effect of the procedure.

Adolescent↗
PubMed1995

Simultaneous detection of fourteen Italian cystic fibrosis mutations in seven exons by reverse dot-blot analysis.

The increasing number of cystic fibrosis (CF) mutations is a great obstacle to the use of DNA procedures in the detection of gene defects. We describe a fast, cheap and non-radioactive procedure, Reverse dot-blot analysis (RDB), for the simultaneous detection of CF mutations in the Italian population. We used this approach to study seven exons of the CF gene for 14 CF gene defects and were able to characterize 222 of 272 CF chromosomes (80%). The cost of the procedure was $25 per sample analysed.

Alleles↗
PubMed1994

Evidence for a globin promoter-specific silencer element located upstream of the human delta-globin gene.

We describe the negative regulatory activity of a 1.7 kilobase (kb) region (R) in the human beta-globin locus located between 4.0 and 2.3 kb upstream of the delta-globin gene capsite, using a transient assay with the chloramphenicol acetyltransferase (CAT) reporter gene in mouse erythroleukemia (MEL) cells. The R region is deleted in most cases of deletion hereditary persistence of fetal hemoglobin (HPFH), but is unaffected in most delta beta zero-thalassemias. However, no experiments addressing its function in globin gene expression have been reported to date. We show that R inhibits CAT expression of constructs containing a fetal (gamma) or adult (beta) globin gene promoter, but does not affect expression of similar constructs using a non-globin (SV40) promoter. The inhibitory effect on the beta-globin promoter can be localized to a 651 bp sub-region of R. For the gamma-globin promoter, no sub-region of R can reproduce the level of inhibition associated with the entire region.

Animals↗
PubMed1993

Rapid and simultaneous typing of hemoglobin S, hemoglobin C, and seven Mediterranean beta-thalassemia mutations by covalent reverse dot-blot analysis: application to prenatal diagnosis in Sicily.

The molecular lesions causing beta-thalassemia in Sicily can be subdivided into two groups. One that occurs at a 71% frequency and consists of the beta 39, IVS 1,110 and IVS 1,6 mutations and the other group at a 20% frequency comprising the -87, beta s, IVS 1,1 and IVS 2,745 mutations. The identification of all these mutations by polymerase chain reaction (PCR) and conventional dot-blot hybridization has been time consuming and expensive. In this article, we describe the implementation of the reverse dot-blot (RDB) hybridization as a rapid nonradioactive method for the identification of the nine most frequent molecular lesions in the beta-globin gene (-87, beta s, beta c, IVS 1,1, IVS 1,6, IVS 1,110, beta 39, IVS 2,1, IVS 2,745) in Sicily. Sixty prenatal diagnoses were performed by this RDB assay, each of which was confirmed by dot-blot/ASO hybridization; thus demonstrating the accuracy of the RDB. The main advantage of this assay is the rapid typing of an individual's DNA for many mutations in a single working day. Because the mutations in this assay are representative for the Mediterranean region, this mutational panel can also be extended to the screening of beta-thalassemia from other Mediterranean regions.

Base Sequence↗
PubMed1993

Alpha interferon treatment of chronic hepatitis C in beta-thalassaemia.

In this open, pilot study, interferon (IFN) alpha-2b seemed effective in the treatment of hepatitis C virus (HCV) infection in patients with beta-thalassaemia. In seven of nine patients who completed the study alanine aminotransferase activities returned to normal, and a completely stable response 24 months after treatment was seen in five. Liver biopsy specimen showed a clear reduction in portal, periportal, and lobular necroinflammation in all five cases. Three patients stopped treatment early because of side effects.

Adolescent↗