Search PubMed⌕ Search

Biomedical subjects

A Cattaneo

Publications and source records attributed to A Cattaneo.

At least 19 recordsLinked to original sources
PubMed2007

Skin-derived stem cells transplanted into resorbable guides provide functional nerve regeneration after sciatic nerve resection.

The regeneration in the peripheral nervous system is often incomplete and the treatment of severe lesions with nerve tissue loss is primarily aimed at recreating nerve continuity. Guide tubes of various types, filled with Schwann cells, stem cells, or nerve growth factors are attractive as an alternative therapy to nerve grafts. In this study, we evaluated whether skin-derived stem cells (SDSCs) can improve peripheral nerve regeneration after transplantation into nerve guides. We compared peripheral nerve regeneration in adult rats with sciatic nerve gaps of 16 mm after autologous transplantation of GFP-labeled SDSCs into two different types of guides: a synthetic guide, obtained by dip coating with a L-lactide and trimethylene carbonate (PLA-TMC) copolymer and a collagen-based guide. The sciatic function index and the recovery rates of the compound muscle action potential were significantly higher in the animals that received SDSCs transplantation, in particular, into the collagen guide, compared to the control guides filled only with PBS. For these guides the morphological and immunohistochemical analysis demonstrated an increased number of myelinated axons expressing S100 and Neurofilament 70, suggesting the presence of regenerating nerve fibers along the gap. GFP positive cells were found around regenerating nerve fibers and few of them were positive for the expression of glial markers as S-100 and glial fibrillary acidic protein. RT-PCR analysis confirmed the expression of S100 and myelin basic protein in the animals treated with the collagen guide filled with SDSCs. These data support the hypothesis that SDSCs could represent a tool for future cell therapy applications in peripheral nerve regeneration.

Action Potentials↗
PubMed2006

Animal model for liver cell banking from non-heart beating donors after prolonged ischaemia time.

BACKGROUND AND AIM: Although there is a growing interest on the use of non-heart beating donors to enlarge the liver donor pool, livers with prolonged warm ischaemia time are not currently considered for organ transplantation. We hypothesised that these organs may represent a source of hepatocytes for cell transplantation and/or use in bioartificial liver devices. Thus, we investigated if prolonged ischaemia could influence the recovery and viability of functional hepatocytes dissociated from rat livers. METHODS: Hepatocytes were isolated from the liver within 15 min after death (t=15 min) and after 4, 8 and 12h of ischaemia. Cells were either maintained in culture or cryopreserved. In all products, we evaluated cell recovery and viability, hepatocyte markers and cellular functions, including albumin and urea production. RESULTS: The number of cells per gram of tissue was similar at 15 min, 4 and 8h, while it was significantly decreased at 12h. About 0.2 x 10(6) viable cells expressing hepatocyte markers and producing albumin and urea were isolated up to 8h of ischaemia per gram of tissue. CONCLUSIONS: Recovery of viable and functional hepatocytes seems possible after prolonged ischaemia time. These data warrant the evaluation of hepatocyte isolation from human livers of non-heart beating donors.

Animals↗
PubMed2006

Structural and functional properties of mouse proNGF.

The unprocessed pro-form of the NGF (nerve growth factor), proNGF (NGF precursor, without signal peptide), has been suggested to have additional functions distinct from its role as a promoter of protein folding, i.e. apoptosis and/or neurotrophic activity. Aiming to gain insights into the specific molecular interactions that mediate proNGF biological activity and into the structural determinants stabilizing its pro-region, rm-proNGF (recombinant mouse proNGF) was expressed in Escherichia coli, refolded in vitro and characterized by physicochemical methods. X-ray solution scattering measurements (small angle X-ray scattering) revealed that rm-proNGF is dimeric in solution and appears to be anisometric when compared with the compact structure of the NGF dimer. Two structural models, a globular crab-like shape and an elongated rod-like shape, equally fit to the experimental results, pointing to an intrinsically structural disordered pro-region of NGF. The models obtained allowed the interpretation of TrkA (tropomyosin receptor kinase A) binding and activation assays in cell cultures, shedding new light on the key role of proNGF in neuronal survival and neurodegeneration.

Animals↗
PubMed2006

Effects of retinoid therapy on insulin sensitivity, lipid profile and circulating adipocytokines.

OBJECTIVE: In vitro and in vivo models indicate that all-trans retinoic acids influence glucose and lipid metabolism. We aimed to evaluate the effects of chronic treatment with acitretin, an all-trans retinoic acid, on glucose metabolism, lipid profile and adiponectin and resistin levels. DESIGN: Ten normoglycemic, normolipemic patients affected with psoriasis vulgaris were studied before and after 1 and 3 months of oral treatment with 35 microg of acitretin. METHODS: Glucose metabolism, lipid profile, and adiponectin and resistin levels were evaluated in basal conditions and after acitretin treatment. Ten healthy subjects matched for age, body mass index (BMI) and insulin sensitivity were studied as controls. RESULTS: One-month acitretin treatment reduced psoriasis activity, insulin sensitivity, evaluated as QUICKI values (0.364 +/- 0.034 versus 0.329 +/- 0.051; P < 0.05) and HOMA-IR index (1.53 +/- 0.73 versus 2.59 +/- 1.41; P < 0.05), and high-density lipoprotein (HDL)-cholesterol levels (45.2 +/- 11.7 versus 39.4 +/- 10.4 mg/dl; P = 0.01). The impairment in glucose and lipid homeostasis was transient and not associated to BMI variations. Adiponectin levels did not change during the treatment, while resistin levels, which were higher in untreated patients than in controls (9.4 +/- 4.4 versus 6.2 +/- 2.1 ng/ml; P = 0.05), fell within the normal range after 1 and 3 months of therapy. The normalization of resistin levels occurred without significant changes in circulating tumor necrosis factor alpha (TNFalpha) levels, which persisted elevated throughout the treatment. CONCLUSIONS: Treatment with a low dose of acitretin induced a mild, transient reduction of insulin sensitivity and HDL-cholesterol levels that was not related to modifications of adiponectin, resistin and TNFalpha levels. Although the role of resistin in humans remains elusive, the levels of this adipocytokine seem to be affected, at least in part, by retinoids.

Acitretin↗
PubMed2005

Improved synthesis and radiolabeling of [11C]MP4A, a suitable ligand for the investigation of the cholinergic system using PET.

An improved synthesis of the precursor acetic acid-piperidine-4-yl ester by acetylation of 4-hydroxypiperidine hydrochloride in anhydrous chloroform was developed. A procedure for fast evaluation and characterization of products originated by acetylation of the 4-piperidinol using LC-APCI/MS with an acetonitrile-water gradient method on a Merck Purosphere RP-18 column was also developed. The highly purified precursor allowed the production of [11C]MP4A for PET studies of acetylcholine neurotransmission system. The tracer was produced with >98% radiochemical purity, with yields ranging 20-60% (decay-corrected) from EOB.

Acetates↗
PubMed2005

Effects of chronic retinoid administration on pituitary function.

It has been reported that retinoids may affect hypothalamic-pituitary-thyroid axis, causing central hypothyroidism. In the present study, we evaluated pituitary function in 11 male psoriatic patients at baseline and after 1 and 3 months of treatment with acitretin (all-trans retinoic acid, 35 mg/day). Serum LH, FSH, testosterone, cortisol, GH and IGF-I levels were not affected by the treatment. By contrast, we observed a significant decrease in TSH levels (from 0.92 +/- 0.3 to 0.80 +/- 0.3 mU/I, p < 0.05) at 1 month, that reverted to baseline after 3 months. No change in free T4 (FT4) levels occurred, while free T3 (FT3) levels were reduced at 1 and 3 months (from 6.7 +/- 0.5 to 6.2 +/- 0.3 and 6.1 +/- 0.6 pmol/l; p < 0.05, respectively). Moreover, acitretin treatment induced a significant reduction of PRL levels after 3 months (from 182 +/- 70 to 150 +/- 56 mU/l, p < 0.05). During treatment, no change in TSH and PRL response either to TRH or dopamine infusion was observed. In conclusion, we demonstrated that treatment with low dose of acitretin induced a series of hormonal modifications that, in addition to a mild and transient reduction of TSH levels, included a persistent reduction of FT3, probably due to changes in thyroid hormone metabolism, and a decrease in PRL levels.

Acitretin↗
PubMed2004

Ochratoxin A in conventional and organic cereal derivatives: a survey of the Italian market, 2001-02.

Ochratoxin A is a mycotoxin produced mainly by Penicillium verrucosum and Aspergillus ochraceus. Although typically considered a cereal contaminant, it has also been detected in dried fruit, nuts, meat and derivatives. To estimate the quantity of ochratoxin A that might be ingested by Italian consumers from these foods, 211 cereal derivatives (flours and bakery products) were analysed by high-performance liquid chromatography. Products were from conventional and organic agriculture and from integrated pest management agriculture. All commercial flours and derivatives examined contained ochratoxin A at concentrations very much below the legal limit (3 microg kg(-1)): the highest value, 0.816 microg kg(-1), was detected in a sample of spelt whole flour from organic agriculture. In many samples, the ochratoxin content was below the limit of detection; only rarely did values exceed 0.5 microg kg(-1). In baby foods, four samples were above the particularly restrictive Italian legal limit of 0.5 microg kg(-1). Although some significant differences were found between samples from conventional and organic agriculture when some product categories were examined (namely, baby foods as semolina and rice creams), no important difference was found between the two types of agricultural practice when all types of cereal derivatives were considered together.

Carcinogens↗
PubMed2004

Characterization of bovine serum albumin epitopes and their role in allergic reactions.

OBJECTIVE: This review provides updated information on conformational and sequential epitopes identified in bovine serum albumin (BSA) and summarizes available data about the role of structural modifications on BSA antigenicity/allergenicity. DATA SOURCES: Data on beef allergy and BSA antigenicity are reported, with reference both to the basic literature and to clinical results obtained by our group. RESULTS AND DISCUSSION: BSA is an important allergen involved in milk and beef allergy. The presence of conformational epitopes has been suggested by indirect evidence, while at least one sequential epitope has been experimentally identified. The role of structural modifications on BSA antigenicity is discussed as well as the increased tolerance observed in allergic subjects consuming beef as strained (homogenized) and freeze-dried derivatives. CONCLUSION: Study of the molecular characteristics of a known major allergen allows the identification of technological processes that may be capable of improving the tolerance of allergic subjects to a specific food. Even though any hoped for reduced allergenicity must be verified under medical supervision, the use of new products could obviate the need to avoid important foods such as meat in childhood.

Allergens↗
PubMed2004

Strategies for identifying genes that play a role in spinal cord regeneration.

A search for genes that promote or block CNS regeneration requires numerous approaches; for example, tests can be made on individual candidate molecules. Here, however, we describe methods for comprehensive identification of genes up- and down-regulated in neurons that can and cannot regenerate after injury. One problem concerns identification of low-abundance genes out of the 30,000 or so genes expressed by neurons. Another difficulty is knowing whether a single gene or multiple genes are necessary. When microchips and subtractive differential display are used to identify genes turned on or off, the numbers are still too great to test which molecules are actually important for regeneration. Candidates are genes coding for trophic, inhibitory, receptor and extracellular matrix molecules, as well as unknown genes. A preparation useful for narrowing the search is the neonatal opossum. The spinal cord and optic nerve can regenerate after injury at 9 days but cannot at 12 days after birth. This narrow window allows genes responsible for the turning off of regeneration to be identified. As a next step, sites at which they are expressed (forebrain, midbrain, spinal cord, neurons or glia, intracellular or extracellular) must be determined. An essential step is to characterize proteins, their levels of expression, and their importance for regeneration. Comprehensive searches for molecular mechanisms represent a lengthy series of experiments that could help in devising strategies for repairing injured spinal cord.

Animals↗
PubMed2003

Homicide in children and adolescents: a case-control study in Recife, Brazil.

OBJECTIVE: The homicide rate for children and adolescents in Recife, Brazil, mostly caused by firearms, is one of the highest that has been reported. The present case-control study was designed to identify factors that were potentially modifiable through preventive interventions. METHODS: Cases were 255 homicide victims under 20 years of age, who had died in 1997 and been identified at the Institute of Forensic Medicine, Police Department, Recife, and whose relatives were interviewed by two community health workers when they claimed the corpse. The 255 controls were neighbours of the cases, paired by age and sex to them, and identified within one week of identification of each case, and whose relatives were interviewed by a third community health worker. FINDINGS: The overall homicide rate in Recife for under-20-year-olds in 1997 was 49 per 100,000; among males aged 15-19 years it was 324 per 100,000. Firearms were responsible for 97% of deaths. After multivariate logistic regression, history of personal police records (odds ratio (OR) = 18.65; 95% confidence interval (CI) = 1.91-182.50), use of illicit drugs (OR = 7.48; 95% CI = 1.86-30.17), tap water at home (OR = 7.30; 95% CI = 1.80-29.59), and maternal age at birth over 26 years (OR = 3.98; 95% CI = 1.79-8.84) were identified as risk factors, while higher education (OR = 0.22; 95% CI = 0.11-0.43), religious practice (OR = 0.25; 95% CI = 0.10-0.65), and presence of the father in the household (OR = 0.28; 95% CI = 0.09-0.81) were protective factors. CONCLUSION: Public health authorities should plan preventive interventions based on the findings of this study and should control the acquisition, possession and carrying of firearms.

Adolescent↗
PubMed2003

Reaction mechanism of caspases: insights from QM/MM Car-Parrinello simulations.

Caspases are fundamental targets for pharmaceutical interventions in a variety of diseases involving disregulated apoptosis. Here, we present a quantum mechanics/molecular mechanics Car-Parrinello study of key steps of the enzymatic reaction for a representative member of this family, caspase-3. The hydrolysis of the acyl-enzyme complex is described at the density functional (BLYP) level of theory while the protein frame and solvent are treated using the GROMOS96 force field. These calculations show that the attack of the hydrolytic water molecule implies an activation free energy of ca. DeltaF(A) approximately equal 19 +/- 4 kcal/mol in good agreement with experimental data and leads to a previously unrecognized gem-diol intermediate that can readily (DeltaF(A) approximately equal 5 +/- 3 kcal/mol) evolve to the enzyme products. Our findings assist in elucidating the striking difference in catalytic activity between caspases and other structurally well-characterized cysteine proteases (papains and cathepsins) and may help design novel transition-state analog inhibitors.

Caspase 3↗
PubMed2003

Dark-rearing decreases NR2A N-methyl-D-aspartate receptor subunit in all visual cortical layers.

Maturation of the visual cortex is a visual experience-dependent process. It has been shown that visual input triggers changes in N-methyl-D-aspartate receptor (NMDAR) subunit expression in the visual cortex. However, no data are available on the layer distribution of these molecular changes. Here we describe the laminar distribution of the cells expressing the NMDAR subunits NR2A and NR2B in the rat primary visual cortex at postnatal day (P) 21 and 37 using anti-NR2A and anti-NR2B antibodies and a stereological method to count labelled neurons. The percentage of neurons expressing the NR2A subunit in the layers II-VI remained unchanged between P21 and P37 with a slight decrease in layer V. Dark-rearing from P21 to P37 induced a pronounced decrease of the staining intensity and a significant decrease in the percentage of NR2A-expressing neurons. The changes in NR2A expression caused by dark rearing occur at similar levels in layers II-VI. The percentage of NR2B-positive cells in the different cortical layers remains unchanged from P21 to P37. The NR2B pattern was not significantly affected by dark-rearing. Thusly, the expression of NR2A depends upon visual experience after P21.

Aging↗
PubMed2003

Evaluation of residual immunoreactivity in red and white wines clarified with gluten or gluten derivatives.

Gluten or hydrolyzed gluten could be a suitable alternative to animal proteins in the wine clarification process, but their residues could represent a risk for individuals suffering from coeliac disease or allergic to cereal proteins. The aim of this study was to investigate the presence of gluten in wines treated with gluten or its hydrolysate in the clarification process and to assess its antigenicity in commercial products. The presence of residual immunoreactive gluten was evaluated by electrophoresis (SDS-PAGE) and immunoblotting. Data obtained in several red and white wine samples showed that no residue was detectable in any of the red wines. In white wines, gluten reduced the protein content less completely, but most samples showed no immunoreactivity after the wine had been treated with gluten or its derivatives, either alone or combined with bentonite, silica gel or tannins. The use of gluten derivatives coupled with bentonite was the most effective method of removing immunoreactive protein in white wines. In conclusion, the use of gluten derivatives in wine clarification seems to exclude a risk for subjects susceptible to coeliac disease or gluten allergy. However, it is recommended that wine producers continuously monitor the clarification process in order to protect the most sensitive individuals.

Antigens↗
PubMed2003

Assessment of residual immunoreactivity in red or white wines clarified with pea or lupin extracts.

Vegetable proteins could be a suitable alternative to animal proteins in the clarification of wine, but their residues could represent a risk for subjects with food allergy or intolerance. The aim of this study was to investigate the presence of specific immunoreactivity in red and white wines treated, as must or wine, with vegetable proteins in the clarification process. The proteins considered were prepared from lupins and peas, which are not included among the allergens listed in annex Illbis of Directive 2003/89/EC. The presence of residual immunoreactivity to specific rabbit anti-lupin and anti-pea polyclonal antibodies in treated wines was assessed by electrophoresis (SDS-PAGE) and immunoblotting. Residual protein was not detectable in red wines clarified with lupin, pea or a mixture of pea and lupin proteins or in white wines clarified with pea proteins. A small number of musts treated with lupin or pea proteins and white wines treated with lupin proteins yielded equivocal results, probably because of the presence of interfering material (e.g., sugar-rich proteins from grape and yeast). The use of bentonite as a secondary clarifying agent is therefore recommended since its combination with vegetable proteins is particularly effective in removing overall protein immunoreactivity.

Animals↗
PubMed2002

Knowledge and opinion on prostate and prevalence of self-reported BPH and prostate-related events. A cross-sectional survey in Italy.

Benign prostatic hyperplasia (BPH) is a very common condition in ageing men and causes considerable morbidity. Although great strides have been made recently, important issues remain under-researched and poorly understood. We have conducted a survey on a representative sample of Italian males to investigate the knowledge and opinion on prostate, to estimate the self-reported prevalence and intensity of BPH and LUTS (low urinary tract symptoms) and to evaluate the performance of the International Prostate Symptom Score (I-PSS) in a population-based sample. Trained interviewers administered a standardized questionnaire to a representative random sample of 671 Italian men aged 50 years and over, between May and June 2000. Univariate and multivariate statistical techniques were used to estimate the prevalence of relevant events, and the associations with selected variables. Only half of responders were able to identify the reason for prostate enlargement, less than one-third recently had spoken with a doctor, and only 8.6% had had a rectal examination. Further, 13.7% (95% confidence interval (CI) 11.1-16.3%) had ever been told they had BPH, with less than half of them receiving surgery for BPH. About 19% reported moderate-severe I-PSS. Both self-reported BPH and severe-moderate LUTS increased significantly with age ( -value <0.01). As to the I-PSS performance, we documented in a community-based sample that it is reliable and valid. Results of the multivariate analysis suggest that, in addition to age, a person's knowledge that they have BPH and a poor perception of health status are the main variables associated with the probability of moderate-severe LUTS. In conclusion, this community-based survey documents that Italian males have a poor knowledge and perception of prostate-related conditions and do not adequately care about them and, thus, do not seek medical attention. These facts notwithstanding, urological conditions such as BPH are common and may largely affect an individual's life. Our findings might help in the design and implementation of effective interventions to improve people's knowledge and understanding of prostate and change their attitudes towards medical care.

Adult↗
PubMed2001

Effect on rates of breast feeding of training for the baby friendly hospital initiative.

PROBLEM: Breastfeeding rates and related hospital practices need improvement in Italy and elsewhere. Training of staff is necessary, but its effectiveness needs assessment. CONTEXT: Eight hospitals in different regions of Italy. DESIGN: Controlled, non-randomised study. Data collected in three phases. Training after the first phase in group 1 hospitals and after the second phase in group 2. STRATEGIES FOR CHANGE: Training of trainers and subsequent training of health workers with a slightly adapted version of the 18 hour Unicef course on breastfeeding management and promotion. KEY MEASURES FOR IMPROVEMENT: Hospital practices, knowledge of 571 health workers, and breastfeeding rates at discharge, three, and six months in 2669 mother and baby pairs. EFFECTS OF CHANGE: After training hospitals improved their compliance with the "ten steps to successful breast feeding," from an average of 2.4 steps at phase one to 7.7 at phase three. Knowledge scores of health professionals increased from 0.41 to 0.72 in group 1 (training after phase one) and from 0.53 to 0.75 in group 2 (after phase two). The rate of exclusive breast feeding at discharge increased significantly after training: 41% to 77% in group 1 and 23% to 73% in group 2, as did the rates of full (exclusive plus predominant) breast feeding at three months (37% to 50% in group 1 v 40% to 59% in group 2) and any breast feeding at six months (43% to 62% in group 1 v 41% to 64% in group 2). LESSONS LEARNT: Training for at least three days with a course including practical sessions and counselling skills is effective in changing hospital practices, knowledge of health workers, and breastfeeding rates.

Adolescent↗
PubMed2001

Purification, crystallization and preliminary X-ray analysis of the Fab fragment from MNAC13, a novel antagonistic anti-tyrosine kinase A receptor monoclonal antibody.

The monoclonal antibody MNAC13 is a potent antagonist that prevents the binding of nerve-growth factor (NGF) to its tyrosine kinase A receptor (TrkA) in a variety of systems. Structural studies of the FabMNAC13 fragment were performed to gain insights into the mechanism of action of this potentially therapeutic monoclonal antibody. The optimal conditions for crystallization of FabMNAC13 were determined. Crystals appeared as prismatic bundles, displayed P2(1)2(1)2(1) space-group symmetry and diffracted to a resolution of 1.8 A. The unit-cell parameters were determined to be a = 52.73, b = 67.55, c = 111.43 A. The data set was 99.5% complete. Molecular replacement was performed, resulting in a correlation coefficient of 0.55 and an R value of 0.40. The structure refinement is now in progress.

Antibodies, Monoclonal↗