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Biomedical subjects

R Gatti

Publications and source records attributed to R Gatti.

At least 37 records · Page 2Linked to original sources
PubMed2002

Molecular analysis of 30 mucopolysaccharidosis type I patients: evaluation of the mutational spectrum in Italian population and identification of 13 novel mutations.

Mucopolysaccharidosis type I (MPS-I orMPS1) is an autosomal recessive condition characterized by a broad range of clinical symptoms. Molecular diagnosis of MPS-I is important for analyzing genotype-phenotype correlation and for selecting patients for innovative therapies. In this study we analyzed 30 Italian MPS-I patients with different phenotypes (20 severe, 6 intermediate, 4 mild) in an attempt to recognize the mutational spectrum in our population and to identify major DNA alterations specific to our country. We identified 93% of mutated alleles (56 out of 60) with the reconstruction of the complete genotype in 26 patients out of 30. Twenty-three different mutations were found, 13 of which are novel while the remaining 10 have been already described. Among the novel mutations we found 5 non conservative missense mutations (A160D, E178K, P183R, G197D, D349Y), one nonsense mutation (C53X), 6 deletions (468-470del3, 486-491del6, 755-759del5, 1251delC, 1839-1867del29, 1902-1903del2), and one splice site mutation (IVS11+5G>A). No common mutation for MPS-I is present in our country. Frequently (40% of the alleles), mutations were found in just one or two patients. However, Q70X, P533R, G51D, and W402X mutations were present in several patients (15%, 13.3%, 13.3%, and 11.6% of the alleles respectively) suggesting a Mediterranean origin of the P533R and G51D mutations. In most cases the patients' genotypes were unique combinations of mutations. The great heterogeneity found in our MPS-I population hampers mutation detection and hinders the genotype-phenotype correlation.

Alleles↗
PubMed2002

Molecular characterisation of GSD III subjects and identification of six novel mutations in AGL.

Deficiency of amylo-1,6-glucosidase, 4-alpha-glucanotransferase enzyme (AGL or glycogen debranching enzyme) is causative of Glycogen Storage Disease type III, a rare autosomal recessive disorder of glycogen metabolism. The disease has been demonstrated to show clinical and biochemical heterogeneity, reflecting the genotype-phenotype heterogeneity among different subjects. The aim of this study was the molecular characterisation of eight unrelated patients from an ethnically heterogeneous population (six Italians, one from India and another one from Tunisia). We describe six novel mutations responsible for the disease (C234R, R675W, 2547delG, T38A, W1327X, IVS6 +3 A>G) and the presence in two Italian subjects of a splice variant (IVS21(+1) G>A) already described elsewhere. This last one is confirmed to be the most frequent mutation among the Italian patients come to our observation, accounting for 28% of 21 patients. One subject was found to be a compound heterozygous. Our data confirm the substantial genetic heterogeneity of this disease. Consequently, the strategy of mutation finding based on screening of recurrent common mutations is limited, as far as regards Italian GSD III patients, to check for the presence of IVS21(+1) G>A.

Adolescent↗
PubMed2002

Pregnancy and tyrosinaemia type II.

A female patient with tyrosinaemia type II is reported having undergone two untreated pregnancies. During pregnancies, plasma tyrosine was raised. The outcomes of both offspring show that maternal tyrosinaemia may have an adverse effect on the developing fetus.

Adult↗
PubMed2002

An Italian severe Salla disease variant associated with a SLC17A5 mutation earlier described in infantile sialic acid storage disease.

The present study reports two Italian brothers affected by severe Salla disease (sialic acid storage disease), a slowly progressive autosomal recessive neurodegenerative disorder prevalent in the Finnish population. Mutations of the SLC17A5 gene, which encodes a protein called sialin, are the primary cause of both Salla disease and infantile sialic acid storage disease (ISSD), a clinically distinct severe disorder. All Finnish patients with Salla disease show a R39C mutation. Both patients showed moderate intellectual disability, spastic ataxic syndrome, hypomyelination and cerebellar atrophy on magnetic resonance imaging (MRI), and lysosomal storage, all typical of Salla disease. Mutation analysis of the SLC17A5 gene in the younger brother revealed no R39C mutation, but a 15-bp deletion in exon 6 on one of the alleles. This mutation is the same described in French-Canadian patients with ISSD. Salla disease must be suspected in patients with unexplained psychomotor retardation associated with ataxia and/or pyramidal symptoms, and MRI findings consistent with cerebral hypomyelination, irrespective of the patient's ethnic origin. A mutation screening based on R39C change does not exclude Salla disease outside Finland. Conversely, mutations found in ISSD can be expected, even in patients showing the Salla phenotype (e.g. symptoms at the milder end of the spectrum).

Adolescent↗
PubMed2002

Employment of confocal microscopy for the dynamic visualization of domes in intact epithelial cell cultures.

Many epithelial cells cultured on plastic ware form domes, fluid-filled localized raisings of the cell monolayer. Domes are due to active vectorial ion transport and their presence demonstrates the maintenance of a differentiated polarized phenotype and of tight junctional complexes. Through a confocal laser microscope equipped with a special flow chamber, intact domes were evaluated in real time for prolonged experimental periods. Both in CAPAN-1 pancreatic duct adenocarcinoma cells and in renal tubular LLC-PK1 cells, vertical sections of calcein-loaded cultures provided a clear visualization of dome outlines during the slow deflation induced by specific agonists (respectively, 1 microM secretin or 10 microM vasopressin). Section series of calcein-loaded domes were used for three-dimensional reconstructions. In CAPAN-1 cultures, cell depolarization induced by secretin was detected with the potentiometric dye bis-oxonol. In the same cells pyranine, a fluid phase marker that is cell impermeant, visualized dome compartment and paracellular pathways, also providing an evaluation of dome fluid pH. Confocal laser scanning microscopy of domes represents a convenient device for the functional assessment of living epithelial cells.

Arylsulfonates↗
PubMed2002

Ultrastructural basis for the efficiency of an ileal orthotopic neobladder 27 years after surgery.

The morphological and functional basis of the excellent clinical outcome of ileal orthotopic neobladders are largely unknown. Only long-term follow-up studies will provide an adequate answer to this unsettled question. We have studied a patient who underwent this type of surgery over 27 years ago. Besides an important secretive adaptation we have found, at the ultrastructural level, that the monolayered epithelium does not show signs of true metaplasia and that changes had occurred in the intercellular junctions, namely that desmosomes are significantly increased. Although limited to a single case, these features, if confirmed by further observations, suggest a working hypothesis for the understanding of the definitive phenotypic adaptation of the ileal epithelium to the new aggressive environment.

Aged↗
PubMed2001

Separation methods for acyclovir and related antiviral compounds.

Acyclovir (ACV) is an antiviral drug, which selectively inhibits replication of members of the herpes group of DNA viruses with low cell toxicity. Valaciclovir (VACV), a prodrug of ACV is usually preferred in the oral treatment of viral infections, mainly herpes simplex virus (HSV). Also other analogues such as ganciclovir and penciclovir are discussed here. The former acts against cytomegalovirus (CMV) in general and the latter against CMV retinitis. The action mechanism of these antiviral drugs is presented briefly here, mainly via phosphorylation and inhibition of the viral DNA polymerase. The therapeutic use and the pharmacokinetics are also outlined. The measurement of the concentration of acyclovir and related compounds in biological samples poses a particularly significant challenge because these drugs tend to be structurally similar to endogenous substances. The analysis requires the use of highly selective analytical techniques and chromatography methods are a first choice to determine drug content in pharmaceuticals and to measure them in body fluids. Chromatography can be considered the procedure of choice for the bio-analysis of this class of antiviral compounds, as this methodology is characterised by good specificity and accuracy and it is particularly useful when metabolites need to be monitored. Among chromatographic techniques, the reversed-phase (RP) HPLC is widely used for the analysis. C18 Silica columns from 7.5 to 30 cm in length are used, the separation is carried out mainly at room temperature and less than 10 min is sufficient for the analysis at 1.0-1.5 ml/min of flow-rate. The separation methods require an isocratic system, and various authors have proposed a variety of mobile phases. The detection requires absorbance or fluorescence measurements carried out at 250-254 nm and at lambdaex=260-285 nm, lambdaem=375-380 nm, respectively. The detection limit is about 0.3-10 ng/ml but the most important aspect is related to the sample treatment, mainly when body fluids are under examination. The plasma samples obtained from human blood are pre-treated with an acid or acetonitrile deproteinization and the supernatant after centrifugation is successively extracted before RP-HPLC injection. Capillary Electrophoresis methods are also discussed. This new analytical approach might be the expected evolution, in fact the analyses are improved with regard to time and performance, in particular coated capillary as well as addition of stabilisers have been employed. The time of analysis is shortened arriving at less than half a minute. Furthermore by using an electrochemical detection, and having a calibration linearity in the range of 0.2-20.0 ng/ml, the detection limit is 0.15 microg/ml. The measurements of acyclovir and penciclovir have been presented but in the future other related drugs will probably be available using CE methods.

Acyclovir↗
PubMed2001

GH/IGF system, cirrhosis and liver transplantation.

The GH-related effects are primarily mediated by insulin-like growth factor I (IGF-I), a peptide hormone almost completely produced by the liver. Liver cirrhosis is usually accompanied by a fall in protein turnover. Furthermore, an important consequence of chronic liver disease (CLD) is growth hormone/insulin-like growth factor (GH/IGF) axis modification and growth failure. Nutritional status also suffers in this condition, and IGF-I has been proposed as a marker of hepatocellular dysfunction, malnutrition and survival. CLD is characterised by alterations of various clinical biochemistry laboratory parameters. Aminotransferases, bilirubin, plasma proteins, together with prothrombin time and gamma globulins, are usually examined for laboratory diagnostic and/or monitoring purposes. These traditional parameters are also used in the perioperative liver transplantation, but an early signal of graft functioning has still not been established. The aim of the present work is a review of the possibility offered by the clinical biochemistry laboratory GH/IGF investigation in the outcome of liver transplantation.

Growth Hormone↗
PubMed2001

Physiological and clinical implications of proANP(1-98) circulating levels in the perioperative phase of liver transplantation.

BACKGROUND: ProANP(1-126), the prohormone synthesized and secreted by atrial myocites, generates an ANP peptide family, the main forms of which are proANP(1-30), proANP(31-67), proANP(1-98) and proANP(99-126). These molecular circulating forms are involved in hemodynamic and electrolyte homeostasis. In cirrhotic patients, volume homeostasis is almost impaired due to abnormal sodium retention, which results in ascites formation and hemodynamic changes, including high cardiac output and low systemic vascular resistance. During liver transplantation, in the anhepatic phase, hemodynamic instability may occur because of decreased venous return due to surgical manipulation of inferior vena cava, considerable blood loss or cross-clamping. Moreover, marked hemodynamic instability is often observed at the reperfusion of the graft. AIMS: The aims of present study are to investigate the changes of ANP during the perioperative phases of Orthotopic Liver Transplantation (OLTx) in end-stage cirrhotic patients. PATIENTS AND METHODS: From July to September 1999, 11 cirrhotic patients undergoing to OLTx were included in the study: seven males and four females (average age 46+/-10.4 years) affected by post-alcoholic cirrhosis [Hypertension 15 (1990) 9], post-hepatitis cirrhosis [D.G. Gardner, M.C. Lapointe, B. Kovacic-Milivojevic, C.F. Deschepper, Molecular analisys and regulation of the atrial natriuretic factor gene, in: A.D. Struphers (Ed.), Frontiers in Farmacology and Therapeutics: Atrial Natriuretic Factor, Blackwell, Oxford, England, 1991, pp. 1-22], Wilson disease [Life Sci. 28 (1981) 89] and polycystic disease [Life Sci. 28 (1981) 89], autoimmune cirrhosis [Life Sci. 28 (1981) 89]. In each patient, a hemodynamic assessment was achieved using a Swan-Ganz catheter. Periferical venous samples were performed during and immediately after OLTx for the determination of ANP(1-98) and other biohumoral parameters. RESULTS: Mean ANP(1-98) (pmol/ml mean+/-SD) basal levels resulted higher than that recorded in the group of healthy subjects. A significant correlation between 24-h post-reperfusion ANP and intra-operative RBC and RIS requirement was found (p<0.05). The basal values resulted significantly higher than that observed at phase II degrees (p<0.04) and lower than that at phase VI degrees (p<0.05); the anesthetic induction values were significantly lower than that observed at phase VI degrees (p<0.03). CONCLUSIONS: ANP(1-98) values may represent a useful marker of hemodynamic derangements during and after OLTx. Further clinical correlations will need a larger patient basis.

Adult↗
PubMed2001

Plasma atrial natriuretic peptide (ANP) fragments proANP (1-30) and proANP (31-67) measurements in chronic heart failure: a useful index for heart transplantation?

The family of the atrial natriuretic peptides, proANP fragments and the active alphaANP, is strongly related to heart disease. The aim was to study in CHF subjects the relation of mdANP and NtANP with brain natriuretic peptide (BNP) and with other traditional medical parameters. Sixteen CHF patients (aged 51.9+/-13.7 years) and 16 healthy subjects age matched (50.8+/-5.9 years) were selected. Both NtANP and mdANP were higher in CHF patients than in healthy subjects (1436+/-288 vs. 288+/-22 pmol/l p<0.001 and 2305+/-383 vs. 423+/-65 pmol/l p<0.0001, respectively). BNP in CHF patients was 28.0+/-9 pmol/l (reference values 1.7+/-1.8 pmol/l). Both NtANP and mdANP demonstrated positive correlation with BNP, p<0.0001 and with left atrial end-systolic volume, p<0.05. BNP correlated with left ventricular mass, p<0.03. In conclusion, plasma NtANP and mdANP analyses are useful laboratory markers in CHF patient investigation and follow up. In particular, they could be employed as non-invasive parameters to follow up worsening of systolic dysfunction until heart transplantation is required.

Adult↗
PubMed2001

Determination of retinoids in galenicals by column liquid chromatography with fluorescence and diode-array detection.

Simple and rapid reversed-phase gradient column liquid chromatography (LC) with fluorescence detection at different wavelengths was developed for the simultaneous analysis of all-trans, 13-cis, 9-cis retinoic acids, vitamin A palmitate and beta-carotene in galenicals. The assay results agreed with those obtained by an LC method with diode-array UV detection. A post-column on-line photochemical reactor (irradiation at 254 and 366 nm) was inserted between the LC column and the fluorescence detector to enhance the performance of the method. Two fluorescence spectra (photoreactor on and off) were obtained for each analyte which proved useful for the unambiguous identification of the various analytes.

Calibration↗
PubMed2001

Molecular analysis of 40 Italian patients with mucopolysaccharidosis type II: New mutations in the iduronate-2-sulfatase (IDS) gene.

Mucopolysaccharidosis type II (MPS2, or Hunter syndrome), rare X-linked lysosomal storage disorder, results from deleterious mutations in the iduronate-2-sulfatase (IDS) gene. We report here the mutational analysis of a total of 40 unrelated Italian MPS II patients ranging from mild to severe phenotype. We are able to assign the genotype to 29 of them (72.5%), identifying 22 different mutations, five of which are unpublished (c.533delTT, W12X, N265I, c.1131-1142del, c.1131-1305del). A total of 55.2% of the molecularly characterised patients resulted from missense mutations, 20.7% from nonsense mutations, and another 13.8% of patients from small deletions (<20pb) or splice mutations, whereas 10.3% of the cases carried major structural alterations such as large deletion and rearrangements. The results reported here support the evidence of the mutational heterogeneity of the IDS gene as well as the difficulty to correlate genotype and phenotype in the patients with MPSII. However, the molecular characterisation of the patients is advantageous, making the carrier detection feasible for the females in the family at risk and improving the reliability of prenatal diagnosis techniques. Moreover, it provides a good foundation for therapeutic strategies.

Cells, Cultured↗
PubMed2001

Prenatal diagnosis of Pelizaeus-Merzbacher disease: detection of proteolipid protein gene duplication by quantitative fluorescent multiplex PCR.

A prenatal diagnosis of Pelizaeus-Merzbacher disease (PMD) resulting from proteolipid protein gene (PLP) duplication was performed by a quantitative fluorescent multiplex PCR method. PLP gene copy number was determined in the proband, the pregnant mother, the male fetus and two aunts. Small amounts of genomic DNA extracted from peripheral blood and from chorionic villi were used. The fetus, in common with the proband, was identified as PMD-affected being a carrier of the PLP gene duplication, inherited from the mother, while the two aunts were non-carriers. The data obtained were confirmed by segregation analysis of a PLP-associated dinucleotide-repeat polymorphism amplified by the same multiplex PCR.

Case-Control Studies↗
PubMed2001

A novel 4-bp deletion creates a premature stop codon and dramatically decreases HEXB mRNA levels in a severe case of Sandhoff disease.

We present the molecular genetic analysis of an infantile-onset Sandhoff disease patient. Genomic DNA amplification, heteroduplex analysis, cloning and sequencing revealed a 4-bp deletion in exon 4 (497 DeltaAGTT). The result is a frameshift mutation that leads to a stop codon in exon 5. This mutation is associated with a dramatic decrease of HEXB mRNA levels.

Base Sequence↗
PubMed2001

Plasma lactate, GH and GH-binding protein levels in exercise following BCAA supplementation in athletes.

Branched chain amino acids (BCAA) stimulate protein synthesis, and growth hormone (GH) is a mediator in this process. A pre-exercise BCAA ingestion increases muscle BCAA uptake and use. Therefore after one month of chronic BCAA treatment (0.2 gkg(-1) of body weight), the effects of a pre-exercise oral supplementation of BCAA (9.64 g) on the plasma lactate (La) were examined in triathletes, before and after 60 min of physical exercise (75% of VO2 max). The plasma levels of GH (pGH) and of growth hormone binding protein (pGHBP) were also studied. The end-exercise La of each athlete was higher than basal. Furthermore, after the chronic BCAA treatment, these end-exercise levels were lower than before this treatment (8.6+/-0.8 mmol L(-1) after vs 12.8+/-1.0 mmol L(-1) before treatment; p < 0.05 [mean +/- std. err.]). The end-exercise pGH of each athlete was higher than basal (p < 0.05). Furthermore, after the chronic treatment, this end-exercise pGH was higher (but not significantly, p = 0.08) than before this treatment (12.2+/-2.0 ng mL(-1) before vs 33.8+/-13.6 ngmL(-1) after treatment). The end-exercise pGHBP was higher than basal (p < 0.05); and after the BCAA chronic treatment, this end-exercise pGHBP was 738+/-85 pmol L(-1) before vs 1691+/-555 pmol L(-1) after. pGH/pGHBP ratio was unchanged in each athlete and between the groups, but a tendency to increase was observed at end-exercise. The lower La at the end of an intense muscular exercise may reflect an improvement of BCAA use, due to the BCAA chronic treatment. The chronic BCAA effects on pGH and pGHBP might suggest an improvement of muscle activity through protein synthesis.

Adult↗
PubMed2001

Correlations of growth hormone (GH) and insulin-like growth factor I (IGF-I): effects of exercise and abuse by athletes.

The importance of hormones on body metabolism when physical exercise is carried out has been established for a long time. Growth hormone (GH) is crucial in energy metabolism as well as in body anabolism. Recent studies have increased our knowledge of GH's mechanisms of action. In particular, insulin-like growth factor I (IGF-I), the main hormone mediating the principal GH effects and other protein structures (i.e. the binding proteins related to these two hormones), has been recognized as playing a crucial role. The biochemical aspects relating to the molecules of the GH/IGF-I axis have been described here. Furthermore, the belief that GH and IGF-I enhance performance has induced an 'abuse' of GH (and possibly of IGF-I) by competitive sports athletes and amateurs. The present study outlines the best methods available to uncover abuse, as well as a series of potential research projects to recognize doping. The review also underlines the principal variables measurable in the laboratory and summarizes published reference ranges of these parameters. These biochemical and laboratory profiles describe principal experimental approaches, with the hope that this will stimulate new ideas on the subject of detecting doping practices.

Doping in Sports↗
PubMed2001

Four year follow-up of a case of fucosidosis treated with unrelated donor bone marrow transplantation.

Fucosidosis is a rare autosomal recessive lysosomal disorder caused by alpha-fucosidase deficiency. We report a child with fucosidosis, second daughter of non-consanguineous parents, for whom biochemical diagnosis followed clinical evidence of the disease in her older sister. Based on previous experiences, the indication to transplant was considered. Since she lacked a matched sibling, an unrelated marrow donor was found. At pre-hematopoietic stem cell transplantation evaluation, first signs of neurological involvement were clinically detectable. MRI showed diffuse hypomyelination and auditory brainstem responses and somatic-sensorial evoked potentials were altered. Visual evoked potentials were normal, tortuosity in the retinal veins and peripapillary hemorrhages were detected. Bone marrow transplantation conditioning was with a regimen of busulphan, thiotepa and cyclophosphamide; in vivo Campath 1G, cyclosporin A and short course methotrexate were given to prevent graft-versus-host disease. The patient engrafted rapidly and her post-transplant course was complicated by moderate graft-versus-host disease, transient episodes of idiopathic thrombocytopenic purpura, repeated septic complications and recurrent episodes of Sweet's syndrome. Sequential short tandem repeat polymorphisms on peripheral blood and bone marrow cells documented the persistence of donor engraftment. Follow-up showed a progressive rise of enzymatic levels. Psychomotor development improved, as confirmed by evaluation of evoked potentials and by MRI scanning.

Bone Marrow Transplantation↗