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Biomedical subjects

A Pini

Publications and source records attributed to A Pini.

At least 37 records · Page 2Linked to original sources
PubMed1997

Concomitant deficiency of beta- and gamma-sarcoglycans in 20 alpha-sarcoglycan (adhalin)-deficient patients: immunohistochemical analysis and clinical aspects.

We have investigated the expression, using immunohistochemistry, of beta- and gamma-sarcoglycans in the muscles of 20 patients in whom previous screening had revealed a deficiency of alpha-sarcoglycan. alpha-, beta- and gamma-sarcoglycans were absent in 7 patients and variably reduced in 8 patients, in 2 of whom beta-sarcoglycan was more reduced than the alpha- and gamma-proteins. In 5 other patients with variably reduced alpha- and beta-sarcoglycans, gamma-sarcoglycan was completely absent. In all patients the distribution of hyposthenia at disease onset was similar, and predominantly involved pelvic girdle muscles; however, the age at onset and rate of disease progression were highly variable. In severely compromised patients, the onset of disease was before 10 years of age and gamma-sarcoglycan or all three sarcoglycans were absent from muscles. Immunohistochemical analysis of sarcoglycans should be part of routine screening for muscle dystrophies to identify patients with sarcoglycanopathy. Gene analysis is necessary to identify the primary defect; however, sarcoglycan immunohistochemistry may be useful for indicating which gene to investigate. Further biochemical characterization of the interactions between these proteins is required to fully elucidate their roles in causing severe, moderate or mild muscular dystrophy.

Adolescent↗
PubMed1997

Surround repulsion of spinal sensory axons in higher vertebrate embryos.

We have tested whether the orientation of axons sprouting from bipolar dorsal root ganglion neurons is influenced by diffusible cues from surrounding tissues. Surface ectoderm, dermomyotome, and notochord exert strong chemorepulsion on axons growing in collagen gels, operating at separations beyond those found in vivo and active in cocultures of chick and mouse tissues. Basal and alar plates of the neural tube are devoid of activity, as is the posterior-half-sclerotome, which repels in a contact-dependent manner. When ganglia are sandwiched between dermomyotome and notochord placed at a distance, axon growth is channeled in a bipolar trajectory. These results show that gradients of diffusible repulsion molecules flanking axon pathways can generate linear patterns of axon growth. We suggest that such "surround repulsion" may function generally, in concert with contact-dependent guidance mechanisms, to guide axons in the developing nervous system.

Animals↗
PubMed1997

Intracellular detection of laminin alpha 2 chain in skin by electron microscopy immunocytochemistry: comparison between normal and laminin alpha 2 chain deficient subjects.

The aim of this study is to localize the alpha 2 laminin chain in normal human skin. The methods used were immuno-gold cytochemistry on cryo-ultramicrotomy sections and thin-section-fracture-label, together with electron microscopy observation. Results were compared with light microscopy peroxidase immuno-staining. Both normal skin samples and skin biopsies from laminin alpha 2 chain deficient congenital muscular dystrophy affected patients were studied. The results show that, in normal skin, the laminin alpha 2 chain is spread throughout the cytoplasm of basal keratinocytes, while it appears associated with desmosomal tonofilaments in the spinous and granular epidermal layers; in skin samples from dystrophic patients the laminin alpha 2 chain was not detectable. These data suggest that the function of the laminin alpha 2 chain is different in the epidermis as compared to that in muscle and peripheral nerve, where it is localized in the basement membrane.

Humans↗
PubMed1997

Targeting by affinity-matured recombinant antibody fragments of an angiogenesis associated fibronectin isoform.

The oncofetal fibronectin (B-FN) isoform is present in vessels of neoplastic tissues during angiogenesis but not in mature vessels. B-FN could therefore provide a target for diagnostic imaging and therapy of cancer. Phage display libraries have been used to isolate human antibody fragments with pan-species recognition of this isoform. We describe the use of these fragments in nude mice to target an aggressive tumor (grafted F9 murine teratocarcinoma). Imaging in real time was done by infrared photodetection of a chemically coupled fluorophore. The targeting was improved by use of affinity-matured fragments with low kinetic dissociation rates (koff = 1.5 x 10(-4) s-1) and also by engineering dimeric fragments via a C-terminal amphipathic helix.

Amino Acid Sequence↗
PubMed1997

Familial Unverricht-Lundborg disease: a clinical, neurophysiologic, and genetic study.

PURPOSE: Progressive myoclonus epilepsies (PMEs) are a clinically and etiologically heterogeneous group of disorders. The authors report clinical, neurophysiological, and genetic findings of a family from Southern Italy with three members affected with PME. METHODS: All data about familial and personal antecedents, clinical history, neurologic examination, laboratory tests, neurophysiological findings, brain imaging studies, and DNA analysis were examined. RESULTS: All results were compatible with the features of Unverricht-Lundborg disease and patients were homozygous for the "Finnish" ancestral haplotype. CONCLUSIONS: Work is in progress to identify and characterize the common EPM1 mutation in the Finnish patients. Subsequently, it will be possible to verify the hypothesis on the existence of a common mutation in the Finnish patients and the Italian family under study, or even in other Mediterranean EPM1 families.

Adult↗
PubMed1996

Phage antibodies with pan-species recognition of the oncofoetal angiogenesis marker fibronectin ED-B domain.

Fibronectin (FN) exists in several polymorphic forms due to alternative splicing. The B-FN isoform (with ED-B domain inserted by splicing) is present in the stroma of foetal and neoplastic tissues and in adult and neoplastic blood vessels during angiogenesis but is undetectable in mature vessels. This isoform, therefore, represents a promising marker for angiogenesis, as already shown using the mouse monoclonal antibody (MAb) BC-1 directed against an epitope on human B-FN. However, this MAb does not directly recognise the human ED-B domain nor does it recognise B-FN of other species; therefore, it cannot be used as a marker of angiogenesis in animal models. In principle, antibodies directed against the human ED-B domain should provide pan-species markers for angiogenesis as the sequence of this domain is highly conserved in different species (and identical in humans and mice). As it has proved difficult to obtain such antibodies by hybridoma technology, we used phage display technology. Here, we describe the isolation of human antibody fragments against the human ED-B domain that bind to human, mouse and chicken B-FN. As shown by immunohistochemistry, the antibody fragments stain human neoplastic tissues and the human, mouse and chicken neovasculature.

Adult↗
PubMed1996

Axon guidance: following the Eph plan.

Recently discovered 'Eph' family receptors and their ligands appear likely to provide the 'cytochemical tags' that Sperry speculated enable axons projecting from the retina to find their correct targets in the brain.

Animals↗
PubMed1996

Clinical heterogeneity of adhalin deficiency.

We report adhalin deficiency in 8 patients with clinically diagnosed muscular dystrophy, dystrophic histopathological features, high plasma creatine kinase levels, normal expression of dystrophin, and marked variability of symptoms. Although the distribution of hyposthenia was similar in all 8 patients and predominantly involved muscles in the pelvic girdle, age at onset and rate of disease progression were highly variable: In 2 patients onset, at ages 24 and 25, was later than has been previously observed. We found no apparent relation between disease severity and the quantity of adhalin expressed. Two kinds of myopathy with adhalin deficiency have been reported: one caused by a mutation in the adhalin gene on chromosome 17 (primary adhalinopathy) and the other linked to chromosome 13. The product of the gene on chromosome 13 is probably associated with adhalin and its deficiency results in secondary adhalinopathy. The severity of clinical phenotypes in these adhalinopathies seems to relate more to the kind and site of the mutations than to the residual amount of the protein. We also detected a variable reduction in the laminin beta 1 subunit by immunohistochemistry in most patients, confirming that this is commonly associated with adhalin deficiency.

Adolescent↗
PubMed1995

Efficient one-step direct labelling of recombinant antibodies with technetium-99m.

High-affinity bacterially expressed antibody fragments can nowadays be cloned from established hybridomas or, more conveniently, isolated directly from antibody libraries displayed on filamentous phage. Such antibodies can be tagged with C-terminal peptide tags containing one cysteine residue, which represents a convenient functionalisation site for a number of applications, including technetium-99m labelling. Here we describe a simple one-step method for 99mTc labelling of cysteine-tagged recombinant antibodies with more than 50% radionuclide incorporation. The labelled antibodies displayed full retention of immuoreactivity and good stability.

Antibodies, Bacterial↗
PubMed1995

Chemorepulsion of developing motor axons by the floor plate.

In the developing nervous system, motor axons grow away from the ventral midline floor plate, suggesting that the latter might be a source of repulsive axonal guidance cues. In donor to host transplantation experiments, ectopic pieces of floor plate were positioned between chick hindbrain motor neurons and their exit points. Immunohistochemistry and retrograde axonal labeling techniques demonstrated that motor axons diverted from their normal pathways to avoid grafted floor plate, often traversing abnormally long circuitous trajectories to reach exit points. When ventral explants of rat hindbrain and spinal cord were cocultured at a distance from floor plate explants within collagen gel matrices, the outgrowth of motor axons was dramatically reduced from explant borders that faced the floor plate. Thus, the floor plate secretes diffusible repulsive cues in vitro that may exclude motor axons from the midline during development.

Animals↗
PubMed1995

[The rehabilitation of the cardiac patient in childhood. Its current status and outlook].

A cognitive survey of the state of the art of cardiac rehabilitation in the pediatric age in Italy has been carried out, involving in the inquiry 22 Centers of Pediatric Cardiology and Cardiac Surgery, and the Italian Societies of Cardiovascular Surgery and Functional Evaluation and Cardiac Rehabilitation, to assess whether this topic has the dimensions of a social problem. The results of this investigation show that there is in Italy an increasing population of post-surgical patients, at least 3,000 per year which, together with about 500 congenital and acquired non-operated patients with heart disease, could benefit by rehabilitation, early or late according to the age. Although considered "important" by most of the inquired cardiologists and cardiac surgeons there are in Italy, up to date, only two Centers suited for pediatric cardiac rehabilitation, which, further, treat only a limited number of patients. Guidelines for functional evaluation and rehabilitative programs are needed to be applied, possibly, in selected rehabilitative Centers for adults.

Adolescent↗
PubMed1994

Axon guidance. Growth cones say no.

A recently characterized protein stops developing axons from growing; a gene family encoding related molecules has also been described.

Animals↗
PubMed1994

Deflazacort in Duchenne dystrophy: study of long-term effect.

A randomized double-blind controlled trial of deflazacort was conducted in 28 Duchenne muscular dystrophy patients either treated with deflazacort 2.0 mg/kg alternate-day therapy or placebo. The deflazacort group showed significant improvement in climbing stairs (P < 0.01), in rising from a chair, Gower's maneuver, and walking (P < 0.0025) after 6 months of treatment. After 1 year, all the above changes remained significantly improved and the MRC index was significantly better (P < 0.05) in the treated group. After 2 years, a significant change was found in the MRC index: higher scores in walking, chair rising (P < 0.02), and grade and time of Gower's maneuver (P < 0.05) were found. The mean time for loss of ambulation for the treated group after we started the trial was 33.2 +/- 9 months; for the placebo group it was 20.5 +/- 11 months (deflazacort vs. placebo group, P < 0.05) [corrected]. Our treated patients lost their ambulation at a median age of 11.8 years vs. 10.5 years in the placebo group. Side effects were mild, consisting of moderate weight gain and slight behavioral changes.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1994

Dyschromatosis symmetrica hereditaria associated with idiopathic torsion dystonia. A case report.

The authors report a case of a family in which a diagnosis of dyschromatosis symmetrica hereditaria was established by a clinical pattern of cutaneous lesions and by assessment of cellular DNA repair synthesis. The skin lesions were characterized by a mixture of hyperpigmented and hypopigmented macules and were localized on the back of the feet of three patients (two male brothers and one sister). All the patients also had small freckle-like pigmented macules on their face. The father presented large symmetrical hypopigmented vitiligo-like macules. In this patient, mottled pigmentation and depigmentation of the extremities had been present since childhood. In the four patients no cellular abnormalities in DNA repair ability were found. These data exclude a mild form of xeroderma pigmentosum. The daughter, a 9-year-old girl, had since the age of 7 also shown a neurological disorder diagnosed as idiopathic torsion dystonia. The authors emphasize the association of dyschromatosis symmetrica hereditaria, a rare cutaneous disease, with idiopathic torsion dystonia, a rare idiopathic neurological disease, in this young girl.

Adolescent↗
PubMed1993

Chemorepulsion of axons in the developing mammalian central nervous system.

During development of the nervous system, distinct populations of nerve cells extend specialized processes, axons and dendrites, over considerable distances to locate their targets. There is strong evidence for two general mechanisms by which these connections are made. The first involves attractive and repulsive interactions, both between cells and between them and their extracellular matrix. The second depends on the release of diffusible chemoattractants by target structures. Evidence is now provided for a mechanism of axon guidance in which diffusible chemorepulsive factors create exclusion zones for developing axons, causing them to turn away from inappropriate territory.

Animals↗
PubMed1993

Ventral spinal cord inhibition of neurite outgrowth from embryonic rat dorsal root ganglia.

Organotypic culture of embryonic rat lumbar spinal cord and dorsal root ganglia has been used to demonstrate an inhibitory effect of ventral spinal cord on neurite growth from dorsal root ganglion explants. When dorsal root ganglion explants from 14-15 day old embryos were cultured alone or in close proximity to a dorsal cord explant, the pattern of dorsal root ganglion neurite outgrowth was typically radial. However, when E14-15 dorsal root ganglion explants were cocultured for 22-24 hours in proximity to a ventral spinal cord explant from the same embryo, few, if any, dorsal root ganglion neurites grew in the direction of the ventral cord explant. This inhibitory effect appeared to be developmentally regulated; it was diminished or absent in cocultures prepared from 18 day old embryos. In contrast, in cocultures of dorsal cord and ventral cord explants from E14-15 embryos, dorsal cord neurites grew abundantly toward the ventral cord explant suggesting that the inhibition is not likely to be due to a nonspecific neurotoxic effect and that the activity responsible selectively inhibits dorsal root ganglion neurite outgrowth. We conclude that a diffusible, primary afferent inhibitory factor(s) produced by embryonic ventral horn may be responsible for the inhibition. Our results are discussed with respect to the possible involvement of inhibition in the normal development of primary afferent innervation of the spinal cord.

Animals↗