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C Tozzi

Publications and source records attributed to C Tozzi.

At least 19 recordsLinked to original sources
PubMed2006

Molecularly imprinted solid-phase extraction method for the high-performance liquid chromatographic analysis of fungicide pyrimethanil in wine.

A method for molecularly imprinted solid-phase extraction (MISPE) of the fungicide pyrimethanil from wine samples has been investigated. The molecular imprinted polymer was obtained by iniferter-mediated grafting on porous chloromethylated polystyrene beads, using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker. The imprinted beads were evaluated for use as a solid-phase extraction sorbent, in order to develop the extraction protocol in aqueous standards and red wine samples. The optimised extraction protocol resulted in a reliable MISPE method suitable for HPLC analysis (stationary phase: Cromolith Performance C18 column, 100 mm x 4.6 mm; mobile phase: acetonitrile-water (3:2, v/v), flow-rate: 1.00 ml/min; detection 270 nm). It was selective for pyrimethanil and the related pyrimidinic fungicides cyprodinil and mepanipyrim, while the non-pyrimidinic fungicides benalaxyl, chlozolinate, furalaxyl, iprodione, metalaxyl, nuarimol, procymidone and vinclozolin were not extracted. Recoveries performed on a wine matrix spiked with pyrimethanil at three different concentration levels were reproducible and were in good agreement with the recoveries performed on buffer, coming out between 80 and 90% (85+/-7.0% at 0.50 microg/ml, 79+/-1.6% at 2.0 microg/ml and 87+/-5.6% at 20 microg/ml). Preconcentration and quantitative extraction of pyrimethanil from wine samples was shown to be feasible down to 0.1 microg/ml.

Chromatography, High Pressure Liquid↗
PubMed2006

Antibody-like peptides as a novel purification tool for drugs design.

New pharmaceutical approaches, such as biotechnology industry, genomic and proteomic studies, require the development of new analytical and preparative tools that should allow the resolution and the characterisation of complex sets of molecule mixtures in a high-throughput mode with the isolation of a single substance from complex matrices in a high degree of purity, low costs and wide availability. In this review we discuss the design of a tailor-made peptide by focusing our attention on the bioinformatic techniques and combinatorial approaches. Then synthesis, purification and characterisation of peptides with recognition properties are discussed by considering different approaches and their fitness to drug design. Moreover, the development of affinity devices and the discussion of their characteristics to optimise the purification phase are reported. Applications of peptide ligands that bind pharmaceutical compounds (i.e. therapeutic proteins, monoclonal antibodies, hormones) are described and analytical tools mentioned and evaluated. Future perspectives, in particular alternative applications of peptide ligands and their substitution with peptidomimetic compounds, are described.

Animals↗
PubMed2005

Cognitive development in low risk preterm infants at 3-4 years of life.

BACKGROUND: Major neurological handicaps and neuropsychological disturbances are more common in ex-preterm children than their counterparts born at term. OBJECTIVE: To establish in a prospective study whether a characteristic neuropsychological profile exists in ex-preterm children who do not exhibit neurodevelopmental deficits on routine clinical examination. METHODS: Thirty intellectually normal children born preterm (30-34 weeks gestation) without major neurological disabilities and a control group of term children matched for age, sex, and parental educational and occupational status were assessed at 3-4 years of age to obtain a complete neuropsychological profile. Intellectual ability, language comprehension and expression, perceptual and visual motor function, working memory, and attention and behavioural problems were investigated. RESULTS: Even in the absence of major neurological signs, children born preterm achieved lower mean scores than controls on the Stanford-Binet intelligence scale (110.8 v 121, p<0.001), visual perception test (33.8 v 42.7, p<0.001), visual motor integration test (42.6 v 47.4, p = 0.049), memory for location test (8.4 v 9.5, p = 0.007), sustained attention test (41.6 v 51.5, p = 0.009), and the picture vocabulary test (33.3 v 44.7, p = 0.021). CONCLUSIONS: Neuropsychological abnormalities can be detected early in childhood in apparently normal ex-preterm children and are consistent with a growing body of evidence that prematurity may be associated with long term neuropsychological morbidity in childhood and adolescence.

Attention↗
PubMed2004

Multivariate analysis of the selectivity for a pentachlorophenol-imprinted polymer.

A pentachlorophenol (PCP)-imprinted polymer (MIP) was obtained by thermal polymerization of a mixture of template, 4-vinylpyridine and ethylene glycol dimethacrylate with molar ratio 1 +3 + 27, using as porogenic solvent methanol-water ( 3 + 1(v/v)). The polymer was packed in an HPLC column and selectivity towards 52 PCP-related phenols (22-chloro-, 21-alkyl-, 4-aryl-, 3-methoxy- and 6-polyphenols) was measured using acetonitrile-acetic acid (99 + 1(v/v)) as mobile phase. The same was made for a reference polymer obtained without pentachlorophenol (NIP). The molecular recognition properties of the imprinted polymer were expressed in terms of selectivity index (SI), calculated for each phenol as k(NIP)/k(MIP). Sixteen molecular descriptors were calculated for each molecule: qO, the partial charge of the phenolic oxygen atom; qH, the partial charge of the phenolic hydrogen atom; Deltaq, the absolute value of the difference qO - qH; HOMO, the highest occupied molecular orbital; LUMO, the lowest unoccupied molecular orbital; Deltaorb, absolute value of the difference HOMO - LUMO; micro(2), the square of total dipole moment; MW, the molecular weight; SAS, the solvent-accessible molecular surface area; hSAS, the hydrophobic solvent-accessible molecular surface area; Svdw, the van der Waals molecular surface area; hSvdw, the hydrophobic part of Svdw; MOv, the molecular ovality; RG, the radius of gyration; logP, the logarithm of n-octanol-water partition coefficient; pK, the phenolic dissociation constant. Correlations between selectivity index and these descriptors were searched utilizing multivariate principal component analysis (PCA). The multivariate model obtained by regression on the principal components correlate collectively several of the calculated descriptors with the polymer selectivity. The magnitude of the model's parameters shows that selectivity is strongly influenced by molecular descriptors having structural character, such as MW, hSvdw and logP, while the effect of molecular descriptors having electronic character, such as qO and pK, is much less marked.

Multivariate Analysis↗
PubMed2001

Molecularly imprinted solid-phase extraction sorbent for the clean-up of chlorinated phenoxyacids from aqueous samples.

A molecularly imprinted polymer (MIP) was synthesized using the herbicide 2,4,5-trichlorophenoxyacetic acid as a template, 4-vinylpyridine as an interacting monomer, ethylendimethacrylate as a cross-linker and a methanol-water mixture as a porogen. The binding properties and the selectivity of the polymer towards the template were investigated by frontal and zonal liquid chromatography. The polymer was used as a solid-phase extraction material for the clean-up of the template molecule and some related herbicides (2,4-dichlorophenoxyacetic acid, fenoprop, dichlorprop) from river water samples at a concentration level of ng/ml with quantitative recoveries comparable with those obtained with a traditional C18 reversed-phase column when analyzed by capillary electrophoresis. The results obtained show that the MIP-based approach to the solid-phase extraction is comparable with the more traditional solid-phase extraction with C18 reversed-phase columns in terms of recovery, but it is superior in terms of sample clean-up.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1999

A general method to perform a noncompetitive immunoassay for small molecules.

A new general method to perform a noncompetitive immunoassay for low-molecular-mass analytes (less than 6000 Da) is described and checked using cortisol as a model system. The method is based on the use of a "polydentate ligand" (cortisol-poly(L-lysine) conjugate) able to block the antibody sites unoccupied by the analyte, followed by the replacement of an antibody-bound analyte by an enzyme-labeled analyte (cortisol-horseradish peroxidase), and permits the direct measurement of the analyte bound sites. The observed signal shows a near-linear correlation with the analyte concentration. The characteristics of interactions between the analyte and polydentate ligand with the specific antibody were studied to perform a preliminary evaluation of the noncompetitive immunoassay for cortisol. The noncompetitive assay was compared with a competitive immunoassay obtained under the same conditions and using the same reagents. The results of the experiments showed a lower detection limit for the noncompetitive model (0.15 ng mL-1 rather than 0.72 ng mL-1), emphasizing that the model is successful. Moreover, as the polydentate ligand is prepared from the same hapten used for the immunogen synthesis, this type of noncompetitive immunoassay appears generally applicable to all small molecules for which antibodies have been obtained.

Animals↗
PubMed1995

Double autosomal/gonosomal mosaic aneuploidy: study of nondisjunction in two cases with trisomy of chromosome 8.

We report cytogenetic and molecular investigations performed in two cases of mosaic trisomy 8 combined with mosaic sex chromosome aneuploidy. In a 35-year-old female, presenting with short stature, gonadal dysgenesis, and a multiple congenital anomalies/mental retardation syndrome typical of trisomy 8, chromosome analysis from peripheral lymphocytes showed the presence of three cell lines, whose karyotypes were 45,X (59.2%), 46,X,+8 (1.2%), and 47,XX,+8 (39.6%), respectively. The same cell lines were found in a skin fibroblast culture, though in different proportions. The second patient, a 9-month-old male with multiple skeletal abnormalities, showed a 47,XY,+8 and a 47,XXY cell line in both peripheral lymphocytes (61.7% and 38.3%, respectively) and skin fibroblasts (92.8% and 7.2%, respectively). To determine the events underlying the origin of these complex karyotypes we performed Southern blot and polymerase chain reaction (PCR) analysis using polymorphic DNA markers from the X chromosome and from chromosome 8. Both supernumerary chromosomes 8, and, in case 2, the two X chromosomes, appeared to be identical, lacking detectable recombination events. We conclude that, in both cases, the most likely mechanism underlying the origin of the mosaic cell lines was formation of a normal zygote, followed by mitotic errors during early divisions.

Abnormalities, Multiple↗
PubMed1994

Split hand/split foot, syndactyly, urinary tract obstruction, radial, diaphragmatic, and neural tube defects: Czeizel-Losonci syndrome?

We report on a baby girl with absence of the left hemidiaphragm, lumbosacral myelomeningocele, syndactyly with limb deficiencies, and bilateral hydronephrosis. A similar array of malformations was described previously by Czeizel and Losonci [Hum Genet 77:203-204, 1987] in a single family which showed a transmission pattern suggesting autosomal dominant inheritance with variable expressivity. The presence of limb abnormalities and the location of the neural tube defects in these cases suggest that the underlying pathogenesis probably does not involve the same disturbances of midline field development which have been postulated to occur in the schisis association.

Abnormalities, Multiple↗
PubMed1994

A new case of interstitial deletion of chromosome 3q, del(3q)(q13.12q21.3), with agenesis of the corpus callosum.

We describe a boy with an interstitial deletion of the proximal portion of chromosome 3q. Prominent physical characteristics were a dysmorphic face with apparent hypertelorism, signs of prenatal lymphedema, foot contractures and agenesis of the corpus callosum. The finding of corpus callosum agenesis in a previously reported patient with an overlapping deletion suggests an additional locus for this malformation.

Abnormalities, Multiple↗
PubMed1993

[The child of hypertensive mother in pregnancy or EPH-gestosis: a long follow-up].

Twenty three children of gestosic mothers or those suffering just from hypertension during pregnancy were studied: the follow-up covered an extremely long period (up to a maximum age of 15) to see if, in time, problems related to blood pressure, growth or of a neurological nature would arise. The results have shown that only weight problems exist, with 21.7% of the subjects being obese, a percentage which is, however, similar to that found among students of the same age group in a Roman school in the same area. It is important to point out the lack of cases of hypertension among these children, (which is probably due to the dietary advice given to them) all of whom have family hypertension and neurological history (taking into consideration that 34.7% were premature). We conclude by emphasizing the importance of long term paediatric follow-up which allows us to be optimistic towards the maternal pathology in as much suitably treated.

Adult↗
PubMed1988

Multiple "marker" chromosomes: a novel cytogenetic finding in a patient with mental retardation and congenital anomalies.

A patient with mental retardation and clinical manifestations suggestive of Noonan syndrome was found to have in her peripheral lymphocytes multiple small accessory marker chromosomes, varying in number from one to five per cell and in size from about half the size of the q arm of a G group chromosome to less than a centromere. Occasionally, in the more elongated markers, a G-positive or a C-positive band could be identified, or the marker had the appearance of a ring. The origin and significance of these marker chromosomes are discussed.

Abnormalities, Multiple↗
PubMed1988

Partial tetrasomy 9 in an infant with clinical and radiological evidence of multiple joint dislocations.

We report on an infant with partial tetrasomy of chromosome 9 due to the presence in her peripheral lymphocytes and in 55% of skin fibroblasts of an isochromosome 9 comprised of the p arm and of a portion of the q arm extending to band q21.1. The phenotype is comparable to that of other cases with a similar chromosome aberration, with multiple joint dislocations as a prominent manifestation.

Arthrogryposis↗
PubMed1977

Preparation, purification and in vitro properties of a serum against human lymphoblastic leukemia-associated antigens.

A serum against human lymphoblastic leukemia cells was obtained inoculating rabbits. We studied the specificity of the serum before and after particular absorptions in various clinical conditions. The serum was cytotoxic against many cases of acute lymphoblastic leukemia, against continuously cultured Burkitt's lymphoma cells and against chronic myelogenous leukemia in blast crisis. On the contrary, the serum was not cytotoxic against lymphocytes of normal donors, acute lymphoblastic leukemia in remission and other lymphoproliferative disorders.

Antibody Specificity↗
PubMedDate not supplied

Mosaic trisomy 17 in amniocytes: phenotypic outcome, tissue distribution, and uniparental disomy studies.

Mosaicism for trisomy 17 in amniocyte cultures is a rare finding, whilst postnatal cases are exceptional. In order to gain insight into the possible effects of the distribution of the trisomic line and of uniparental disomy (UPD) on embryofoetal development, we have performed follow-up clinical, cytogenetic and molecular investigations into three newly detected prenatal cases of trisomy 17 mosaicism identified in cultured amniotic fluid. In the first case, the pregnancy ended normally with the birth of a healthy girl, and analysis of newborn lymphocytes and of multiple extra-embryonic tissues was indicative of confined placental mosaicism. The second case was also associated with a normal pregnancy outcome and postnatal development, and only euploid cells were found in peripheral blood after birth. However, maternal isodisomy 17 consequent to a meiosis II error and loss of a chromosome 17 homologue was detected in peripheral lymphocytes postnatally. In the third case, pathological examination after termination of pregnancy showed growth retardation and minor dysmorphisms, and the trisomic line was detected in foetal skin fibroblasts. In addition, biparental derivation of chromosome 17 was demonstrated in the euploid lineage. These results, together with previously reported data, indicate that true amniotic trisomy 17 mosaicism is more commonly of extra-embryonic origin and associated with normal foetal development. Phenotypic consequences may arise when the trisomic line is present in foetal tissues. Case 2 also represents the first observation of maternal UPD involving chromosome 17; the absence of phenotypic anomalies in the child suggests that chromosome 17 is not likely to be subject to imprinting in maternal gametes.

Adult↗
PubMedDate not supplied

Functionalized biopolymers as soluble macromolecular chelating agents.

Two different conjugates of bovine serum albumin (BSA) with lysine and a derivative of imidazole have been synthesized to obtain watersoluble macromolecules with binding properties against bivalent transition metal ions. Syntheses have been carried out using the 60 aminogroups or the 99 carboxylic groups on BSA for the coupling reactions, with such molar ratios able to produce highly substituted BSA. The skill of each conjugate to bind metal ions in aqueous medium was studied through the use of titration curves with some metal ions, characterized by a good affinity for the free ligand. Both the conjugates allow us to recover a high number of metal ions per protein molecule, close to the number of ligand molecules on the BSA surface in the case of the lysine conjugate, whereas in the case of the imidazole conjugate M3L complexes are performed.

Biopolymers↗