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Biomedical subjects

A Bardoni

Publications and source records attributed to A Bardoni.

31 records · Page 2Linked to original sources
PubMed1994

Cognitive impairment in Duchenne muscular dystrophy.

Cognitive function and dystrophin gene mutations were investigated in 50 DMD patients (mean age 11.1 yr; range 3.5-20.3). General intelligence assessment showed 31% of patients with Wechsler full intelligence quotient (FIQ) lower than 75 (normal values: 100 +/- 14), and only 24% with appropriate FIQ level. Modal distribution of Wechsler verbal, performance, and FIQs, and Raven IQs was normal. Verbal IQ was more affected than performance IQ (PIQ) only in the younger group of subjects. Low PIQ correlated with the presence of macroglossia, detected in 13 out of 50 patients. Impairment of productive language was of non-dysphasic nature and correlated with defects of short-term memory, which was also affected in non-verbal skills. DMD patients shared the same spectrum of neuropsychological defects, regardless of whether they were or were not mentally retarded. The proportion of patients with dystrophin gene deletions was 64%. No statistically significant correlations were found between genetic data and psychometric assessment. Finally, (18F)-fluorodeoxyglucose positron emission tomography studies demonstrated cerebellar hypometabolism in all the DMD patients examined and variable involvement of associative cortical areas. These findings suggest a possible role of the cerebral and cerebellar hypometabolism in the cognitive impairment of DMD.

Adolescent↗
PubMed1994

Clinical variability in Becker muscular dystrophy. Genetic, biochemical and immunohistochemical correlates.

We have investigated 59 Becker muscular dystrophy patients, representing 56 independent mutations, to test the hypothesis of predictability of muscle dystrophin expression and clinical phenotype based on location of dystrophin gene mutations. Partial intragenic deletions and duplications account for 82% of the independent mutations, of which 76.7% were deletions and 5.3% duplications. Mutations in which boundaries could be defined, were of in-frame type (35 out of 37, 94.6%, with two exceptions. Eighty-two percent of mutations were located at the distal part of the rod domain (exons 45-60), 9% at domain I (promoter through exon 9) and 9% at proximal and central parts of domain II. Domain I deleted patients tended to have a worse clinical phenotype, with earlier presentation, faster progression rate and lower dystrophin expression, while distal rod domain deleted patients showed a more classic Becker muscular dystrophy phenotype. Between these two groups, only the differences in the immunohistochemical patterns of dystrophin expression and disease progression rate were statistically significant. Partial clinical and biochemical heterogeneity was observed in the distal domain II patient group, due to the presence of few patients covering the extremities of clinical severity. Two asymptomatic patients had deletions located in the central (exons 41-44) and distal parts (exons 50-53) of the rod domain. Severe myalgia and cramps were often reported as early onset symptoms (18 out of 59): no correlation was found between this symptomatology and the location of the mutation. Relative levels of muscle dystrophin correlated with immunohistochemical patterns of subsarcolemma staining. Dystrophin levels (as estimated by 30 kDa antibody immuno-reactivity) correlated with age of reaching a moderate degree of muscle involvement as well as with delay in reaching that stage, a parameter of disease progression rate. Our data confirm that different Becker muscular dystrophy gene in-frame mutations have different effects on dystrophin expression and clinical severity, indicating several functional roles of the dystrophin domains.

Adolescent↗
PubMed1993

Modifications of proteoglycans produced by human skin fibroblast cultures during replicative senescence.

The properties of proteoglycans (PGs) produced by normal human skin fibroblasts were investigated with increasing passage. The increase of subculture number was associated with a constant increase in PG molecular size, which was particularly evident in cell layer extracts. In the cell layer, the ratio of DS-PGs/HS-PGs was markedly higher in early passage cultures. Moreover, the cell layer from young cells contained lower amounts of radioactivity incorporated into the most hydrophobic PG populations, suggesting that the PG core protein might also undergo significant modification with increasing subcultures. There was no significant difference in energy charge value between early and late passage cultures, whereas the NAD/NADH ratio was found to decrease markedly in senescent cells.

Cell Division↗
PubMed1992

Modifications of adhesion properties and proteoglycan structure in rat embryo fibroblast cultures with increasing passages.

Adhesion properties of rat embryo fibroblast cultures and proteoglycans (PGs) produced both in the growth medium and in the cell layer were investigated with increasing passages. Both cell-cell and cell-substrate adhesion increased with increasing subculture number. Cell adhesion properties were improved by cell treatment with chondroitinase ABC. The increase in subculture number was coupled with a constant increase of PG molecular size, which was particularly evident in cell layer extracts. The ratio HS-PGs/DS-PGs increased with increasing passages. PG modifications are likely to represent evidence of changes in extracellular matrix organization and could play a role in the increase of cell adhesion properties.

Animals↗
PubMed1987

Re-evaluation of the structural integrity of red-cell glycoproteins during aging in vivo and nutrient deprivation.

Results presented in this paper show that removal of white-cell contaminations from human red blood cells by filtration through cellulose [Beutler, West & Blume (1976) J. Lab. Clin. Med. 88, 328-333] is a necessity whenever red cells are incubated at elevated temperatures or haemolysed after density separation. Omission of this precaution results in proteolysis of sialoglycoproteins in membranes from less-dense (young), but not dense (old), subpopulations. This proteolytic damage occurs during haemolysis of the cytoplasmic domain of glycophorin. A different type of proteolysis occurs if white-cell-contaminated red cells are incubated in the absence of glucose at elevated temperatures. Red cells release sialoglycopeptides. This process is stimulated by Ca2+ ions and is accompanied by the release of vesicles that differ from spectrin-free vesicles [Lutz, Liu & Palek (1977) J. Cell Biol. 73, 548-560]. This sialoglycopeptide release is dependent on white-cell contamination and is not required for the release of spectrin-free vesicles.

Cell Separation↗
PubMed1984

Protection of rat gastric mucosa against ethanol injury by the new synthetic prostaglandin MDL 646.

Oral administration to fasted rats of absolute ethanol produces extensive necrotic lesions of gastric mucosa as well as a massive leakage of proteins and mucus glycoproteins into gastric lumen. When the new synthetic prostaglandin MDL 646, belonging to the PGE1 series, is administered intragastrically (2 or 10 micrograms/kg) 30 min before ethanol administration, a significant protection of rat gastric mucosa against alcohol injury is observed.

Alprostadil↗
PubMed1984

Electrophoretic and lectin-binding properties of glycopeptides released from the membrane during "in vitro" aging of human erythrocytes.

During in vitro aging of human erythrocytes sialopeptides are lost from the membrane in a process which appears to act on glycophorins. This glycopeptide material can be purified by affinity chromatography on Wheat germ agglutinin-Sepharose, as glycophorin does. The electrophoretic behaviour of the purified material suggests that the glycopeptide comes from the breakdown of the domain of glycophorin exposed on the surface of the membrane. The binding properties toward Phaseolus vulgaris E lectin indicate that the only N-linked sugar chain of glycophorin is present in the sialopeptide released from the membrane; therefore we can argue that the glycophorin breakdown during in vitro aging of red cell takes place beyond the 26th residue of the sequence, and probably quite near the lipid bilayer.

Chromatography, Affinity↗
PubMed1980

Interactions between bovine cornea proteoglycans and collagen.

Two types of proteoglycan subunits were obtained from bovine cornea, the first mainly composed of proteochondroitin sulphate and the second of proteokeratan sulphate. These two fractions can be obtained from the tissue as an aggregate, and are able to recombine each other after separation, to re-form the original structure. In order to investigate collagen-proteoglycan interactions, type-I collagen was isolated from bovine cornea by pepsin digestion followed by 3.5% (w/v) NaCl precipitation, and was then linked to CNBr-activated Sepharose 4B. Two identical columns were prepared, the first filled with collagen coupled to Sepharose 4B, the second with free Sepharose 4B. The two proteoglycan subunits and the aggregate were chromatographed on the two gels under the same conditions; the elution profiles showed that both the aggregate and the proteochondroitin sulphate subunit are retarded by the collagen coupled to Sepharose. No interaction, however, occurred when proteokeratan sulphate subunit was run through the columns. Chondroitinase digestion of the proteoglycan samples confirmed that chondroitin sulphate chains are mainly responsible for the interaction with collagen; their removal, in fact, completely abolishes any differences between the chromatographic behaviour on the collagen-Sepharose and the control columns.

Animals↗
PubMedDate not supplied

Autoantibodies to RNA-polymerases in Italian patients with systemic sclerosis.

OBJECTIVE: To assess the frequency and clinical correlates of the systemic sclerosis-related autoantibodies to RNA polymerases in Italian patients. METHODS: Sera from 115 patients with systemic sclerosis (SSc) and 10 patients with systemic sclerosis-overlap syndromes recruited from a single center in northern Italy were investigated for antibodies to RNA polymerase I, II, and III by means of immunoprecipitation using 35S-labeled HeLa cell antigen extract. Twenty-five normal volunteers and 91 patients with different connective tissue diseases were studied as a control group. RESULTS: Antibodies to RNA-polymerases were found in 14/115 SSc patients (12.1%). None of the normal controls and none of the patients with other connective tissue diseases, including overlap syndromes, were positive. Antibodies reacting with RNA-polymerase I and III (+/- RNA-polymerase II) were found in 9/115 patients (7.8%) and were mutually exclusive with respect to other scleroderma-related autoantibodies. Isolated anti-RNA polymerase II reactivity was found in 5 patients and was associated with anti-topoisomerase I antibodies in 4 cases. Anti-RNA-polymerase I and III antibodies were associated with diffuse cutaneous involvement and male gender. Only two patients from our series had scleroderma renal crisis, and one of them had anti-RNA polymerase antibodies. CONCLUSIONS: Anti-RNA-polymerase antibodies appear to be less frequent in Italian patients than in Caucasian patients from the United Kingdom or USA. This might be associated with the lower frequency of scleroderma renal crisis.

Adult↗
PubMedDate not supplied

Localized and systemic forms of scleroderma in adults and children .

Systemic sclerosis (SSc) presents a great deal of variability in the extent and severity of skin and internal organ involvement. The diagnostic and prognostic significance of autoantibodies in SSc is undisputed and the patient's autoantibody profile represents a fundamental tool for clinicians. Scleroderma is a rare condition in children. Unlike adults, localized scleroderma is more frequent than the systemic sclerosis, nevertheless it represents a disabling condition. In both conditions, no validated outcome measures and proven effective treatment is available to date.Raynaud's phenomenon (RP) is one the most common and significant clinical symptoms of SSc and therefore in patients with RP a capillaroscopic analysis should be carried out as soon as possible. The actual and select advantage of the early nailfold videocapillaroscopic (NVC) analysis is to distinguish between the primary RP and the secondary RP and to allow the early detection of SSc.

Adult↗
PubMedDate not supplied

Biosynthesis of glycosaminoglycan precursors: evidences for different tissue specific forms of UDP-glucose dehydrogenase.

UDP-glucose dehydrogenase (UDPGDH) was extracted and partially purified from different rat tissues and the kinetic parameters and some properties of the enzyme were determined and compared. The pH optimum ranged between 8.6 and 9.4 for liver and kidney UDPGDH and between 8.4 and 8.6 for skin and lung UDPGDH. Liver and kidney enzymes showed a similar affinity for both UDPG and NAD. Lung and skin enzymes also showed similar affinity for both substrates, which differed however from that of liver and kidney UDPGDH. Both liver and kidney enzymes had a higher heat stability and a different electrophoretic mobility compared to skin and lung UDPGDH. These data suggest the existence of different tissue specific forms of the enzyme.

Animals↗
PubMedDate not supplied

Collagenase-extractable proteoglycans from lesion-free areas of human aorta.

Different proteoglycan (PG) populations were isolated from normal human aorta by extraction of minced tissue with 4M GuHCl and by further digestion of the residue with collagenase. Dissociative extraction induced a complete disappearance of Alcian Blue positive material, which was demonstrable by transmission electron microscopy before the treatment around collagen fibrils and in pericellular areas. However, 4M GuHCl extraction solubilized only an average of 60% of aorta total hexuronate content. Collagenase treatment of the residue resulted in a complete loss of collagen fibril organization, which was coupled with a further hexuronate recovery, accounting for about one third of total tissue content. The bulk of PGs obtained in collagenase digest was retained by Sepharose CL-4B column. Their sulphated glycosaminoglycan (GAG) composition differed from PGs extracted with 4M GuHCl, containing only chondroitin sulphate (CS) and heparan sulphate (HS), without detectable traces of dermatan sulphate (DS). Moreover, they contained hyaluronic acid. The results obtained by agarose polyacrylamide gel electrophoresis (APGE) and Octyl-Sepharose chromatography, followed by further APGE and Sepharose CL-4B gel-filtration, carried out before and after treatment with Chondroitinase ABC and AC and Heparinase I and III, suggested that collagenase digest contained different PG populations, carrying mainly either CS or HS chains. Moreover, HS containing PGs showed higher hydrodynamic size and stronger properties of hydrophobic interactions than CS containing PGs.

Adult↗