PubMed Health⌕ Search

Biomedical subjects

S Costanzo

Publications and source records attributed to S Costanzo.

At least 19 recordsLinked to original sources
PubMed2005

QTL analysis of late blight resistance in a diploid potato family of Solanum phureja x S. stenotomum.

Field resistance to Phytophthora infestans (Mont.) de Bary, the causal agent of late blight in potatoes, has been characterized in a potato segregating family of 230 full-sib progenies derived from a cross between two hybrid Solanum phureja x S. stenotomum clones. The distribution of area under the disease progress curve values, measured in different years and locations, was consistent with the inheritance of multigenic resistance. Relatively high levels of resistance and transgressive segregations were also observed within this family. A genetic linkage map of this population was constructed with the intent of mapping quantitative trait loci (QTLs) associated with this late blight field resistance. A total of 132 clones from this family were genotyped based on 162 restriction fragment length polymorphism (RFLP) markers. The genome coverage by the map (855.2 cM) is estimated to be at least 70% and includes 112 segregating RFLP markers and two phenotypic markers, with an average distance of 7.7 cM between two markers. Two methods were employed to determine trait-marker association, the non-parametric Kruskal-Wallis test and interval mapping analysis. Three major QTLs were detected on linkage group III, V, and XI, explaining 23, 17, and 10%, respectively, of the total phenotypic variation. The present study revealed the presence of potentially new genetic loci in this diploid potato family contributing to general resistance against late blight. The identification of these QTLs represents the first step toward their introgression into cultivated tetraploid potato cultivars through marker-assisted selection.

Chromosome Mapping↗
PubMed2004

Mapping genes for resistance to Verticillium albo-atrum in tetraploid and diploid potato populations using haplotype association tests and genetic linkage analysis.

Verticillium wilt disease of potato is caused predominantly by Verticillium albo-atrum and V. dahliae. StVe1 -a putative QTL for resistance against V. dahliae -was previously mapped to potato chromosome 9. To develop allele-specific, SNP-based markers within the locus, the StVe1 fragment from a set of 30 North American potato cultivars was analyzed. Three distinct and highly diverse haplotypes can be distinguished at the StVe1 locus. These were detected in 97%, 33%, and 10% of the cultivars analyzed. We tested for haplotype association and for genetic linkage between the StVe1 haplotypes and resistance of tetraploid potato to V. albo-atrum. Moreover, field resistance was assessed in diploid populations with known molecular linkage maps in order to identify novel QTLs. Resistance QTLs against V. albo-atrum were detected on four chromosomes (2, 6, 9, and 12) at the diploid level, with one QTL on chromosome 2 contributing over 40% to the total phenotypic variation of the trait. At the tetraploid level, a significant association between the StVe1-839-C haplotype and susceptibility to the disease was detected, suggesting that resistance-related genes directed against V. albo-atrum and V. dahliae are located in the same genomic region of chromosome 9. However, on the basis of the present analysis, we cannot determine whether these genes are closely linked or if a single gene provides resistance against both Verticillium species. To assess the usefulness of the StVe1-839-C haplotype for marker-assisted selection, we subjected the resistance data to Bayesian analysis, and calculated positive (0.65) and negative (0.75) predictive values, and overall predictive accuracy (0.72). Our results indicate that tagging of additional genes for resistance to Verticillium with molecular markers will be required for efficient marker-assisted selection.

Base Sequence↗
PubMed2003

Linkage disequilibrium mapping of a Verticillium dahliae resistance quantitative trait locus in tetraploid potato ( Solanum tuberosum) through a candidate gene approach.

We have used the linkage disequilibrium mapping method to test for an association between a candidate gene marker and resistance to Verticillium dahliae in tetraploid potato. A probe derived from the tomato Verticillium resistance gene ( Ve1) identified homologous sequences ( StVe1) in potato, which in a diploid population map to chromosome 9, in a position analogous to that of the tomato resistance gene. When a molecular marker closely linked (1.5 cM) to the homologues was used as a candidate gene marker on 137 tetraploid potato genotypes (mostly North American cultivars), the association between the marker and resistance was confirmed ( P<0.001). The amount of phenotypic variation in resistance explained by the allele of the STM1051 marker was greater than 10% and 25% in two subpopulations that were inferred from coancestry data matrix. Cloning of homologues from the highly resistant potato cv. Reddale indicates that the resistance quantitative trait locus (QTL) comprises at least an eleven-member family, encoding plant-specific leucine-rich repeat proteins highly similar to the tomato Ve genes. The sequence analysis shows that all homologues are uninterrupted open reading frames and thus represent putative functional resistance genes. This is the first time that the linkage disequilibrium method has been used to find an association between a resistance gene and a candidate gene marker in tetraploid potato. We have shown that it is possible to map QTL directly on already available potato cultivars, without developing a new mapping population.

Chromosome Mapping↗
PubMed2003

Epidemiological profile of symptomatic osteoarthritis in older adults: a population based study in Dicomano, Italy.

OBJECTIVES: To assess the prevalence of hand, hip, and knee osteoarthritis (OA) in an older Italian community dwelling population and its association with disability. METHOD: A cross sectional survey of the whole community aged 65 years and over, was carried out in Dicomano, a small rural town in Tuscany, Italy. Subjects were screened by geriatricians for major chronic conditions, including hip, knee, and hand OA, using diagnostic algorithms based on the American College of Rheumatology (ACR) clinical criteria. A rheumatologist examined subjects who screened positive. Disability was assessed by a World Health Organisation questionnaire. RESULTS: 697 of 864 eligible subjects (81% of the eligible population) were screened. OA of the knee, hand, or hip was identified by clinical ACR criteria respectively in 159, 139, and 81 subjects, and was confirmed by the rheumatologist in 158/182 (87%), 75/101 (74%), and 63.2% of cases. The estimated prevalence was 29.8%, 14.9%, and 7.7%, respectively. Only hip OA was significantly associated with disability in basic activities of daily living. CONCLUSIONS: About one third of community dwelling older people are affected by symptomatic peripheral OA. Hip OA was strongly associated with disability.

Activities of Daily Living↗
PubMed2001

Adsorption of the organic fraction of a tannery sludge by means of organophilic bentonite.

Two different organophilic bentonites obtained by cationic exchange with benzyldimethyloctadecylammonium chloride and trimethyloctadecylammonium chloride have been used to adsorb the organic fraction of a tannery sludge. The exchange process was carried out to different extents to obtain bentonite samples with different organophilicities and different interlayer spacings. Before adsorption, the organic matter was extracted by contacting the sludge with a Ca(OH)2 saturated solution. The adsorption capacity was found to increase with the amount of ammonium salt exchanged for both bentonites, but the one exchanged with benzyldimethyloctadecylammonium chloride proved to be more active: up to about 80% TOC could be removed from the contacting solution. The adsorption of the organic matter caused a further increase of the bentonite interlayer spacing. In both cases, the adsorption isotherms were found to be of cooperative type, due to weak adsorbent-adsorbate interactions at low loading followed by increasing adsorbate-adsorbate interactions at increasing loading. The results may be applied to tannery sludge stabilization by cementitious systems.

Adsorption↗
PubMed1997

Characterization of Cu,Zn superoxide dismutase from the bathophile fish, Lampanyctus crocodilus.

Cu,Zn SOD from the bathophile teleost Lampanyctus crocodilus (LSOD) shows a high degree of homology with the sequence of the enzymes from other teleostean fish species. The catalytic properties of LSOD are very similar to those of the bovine enzyme, albeit with higher sensitivity to thermal denaturation. The apparent molecular mass of LSOD (37.6 KDa) is higher than the other Cu,Zn SOD variants studied. The aminoacid sequence of LSOD reveals interesting substitutions compared to the bovine enzyme. These are discussed in view of the particular environmental conditions to which L. crocodilus is adapted.

Amino Acid Sequence↗
PubMed1995

Identification of the residues responsible for the alkaline inhibition of the activity of Cu,Zn superoxide dismutase: a study of native and chemically modified enzymes.

The pH dependence of the activity of Cu,Zn superoxide dismutases from bovine erythrocytes and shark liver was studied by pulse radiolysis in both the native enzymes and those chemically modified at lysine side chains. The study was aimed at identifying the residues responsible for the activity decrease at pH > 9, observed in all native Cu,Zn superoxide dismutases, and is based on the Lys-->Arg substitution present in the shark protein at position 134, which has been established to be critical for the catalytic efficiency of the enzyme. Both native enzymes display a pH dependence that can be deconvoluted by three deprotonation equilibria, at pH 9-9.5 (pK1), at pH 10.2 (pK2), and at pH 11.5 (pK3). pK1 is lacking in both the modified enzymes and thus can be assigned to activity-linked lysine residues. pK2 is clearly dominated by Arg134 in the modified shark enzyme and can be assigned to surface arginine residues. pK3 is shared by all four enzyme forms and is likely to be due to the invariant Arg141.

Amino Acid Sequence↗
PubMed1993

Relationship between health status, fluid intelligence and disability in a non demented elderly population.

This study examines the impact of overall health status and common chronic medical conditions on cognitive performance in an older population and the effect of poor cognitive performance on functional disability. The study population consisted of 485 subjects who were 77 and 78 years old, and residing in district No. 6 of the city of Florence; all participants underwent a structured interview to collect information on demographics, education, physical health, disability, and cognitive status. Data from 94 subjects, who were previously diagnosed as affected by dementia or other conditions known to be direct causes of cognitive impairment, and from 6 subjects, who scored less than 20 in the Mini-Mental State Examination, were excluded from the analysis. The number of chronic conditions, drugs used, contacts with the physician, days in bed, and days of hospitalization in the last 6 months were considered as indicators of physical health. Functional disability was assessed evaluating both ADLs and IADLs. The Mini-Mental State and the "Blocks" test, a component of the Wechsler Adult Intelligence Scale Revised, were used for the assessment of cognitive status. After adjusting for the level of formal education, physical health status and several specific chronic conditions were predictors of cognitive performance. A significant association was found between a low "Blocks" test score and a decreased level of functional status. In a multivariate model, better performance on the "Blocks" test was associated with a higher score in the disability scale. This association was independent of the effect of education. The results suggest that in the elderly, poor health status is associated with a cognitive impairment that can be measured by the "Blocks" test. However, the role of this association in the pathway from disease to disability remains unclear.

Activities of Daily Living↗
PubMed1983

[Hypnosis and cancer: a working hypothesis. Initial notes].

Hypnosis has been used to resolve stress and anxiety following profound psychological-behavioural changes occurring in the cancer sufferer from the moment of diagnosis. It is stated that hypnosis is useful in improving sick persons' quality of life through the control of stress reactions, simplification of treatment and facilitation of rehabilitation, both within the family and socially. Through deep seated psycosomatic interconnections, psychological attitude can affect organic reaction to all disease, cancer included.

Humans↗