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Biomedical subjects

P Antonelli

Publications and source records attributed to P Antonelli.

At least 19 recordsLinked to original sources
PubMed2004

Alport syndrome: HLA association and kidney graft outcome.

Alport syndrome (AS) is a genetic disease of type IV collagen involving non-homogeneous patterns of inheritance characterized clinically by the presence of progressive haematuric nephritis leading to end-stage renal disease (ESRD), hearing loss and/or ophthalmologic abnormalities. The aim of this study was to investigate, in a cohort of AS patients who had undergone a kidney graft (KG) or who were still on a waiting list for a KG, (a) whether there is a correlation between AS and HLA antigen expression, and (b) long-term graft outcome in transplant patients. The AS cohort was represented by 34 ESRD patients, of whom 25 received a KG and the remaining nine were still on a waiting list. AS transplant patients represented 2.78% of 899 first KGs performed at our centre (Transplantation Department at S. Martino Hospital, Genoa) between 1983 and 2002. Grafts were procured from cadaveric donors in 18 cases and from living, related donors in seven cases. All AS transplant patients had a post-transplant follow-up period of at least 12 months. Results showed that: (i) the frequency of the HLA-DRB1*16 antigen was significantly increased in the whole AS cohort as compared to 128 healthy subjects (HS) (corrected P-value 0.0026; relative risk 7.20) as well as to 232 non-AS ESRD patients on a waiting list for KG (corrected P-values 0.0156; relative risk 4.67); (ii) 5- and 10-year graft survivals in the AS transplant patients were 80 and 73%, respectively, and did not differ from those of a control group represented by 25 non-AS KG recipients matched for sex, age, number of HLA mismatches and immunosuppressive treatment. Increased frequency of HLA-DRB1*16 in AS patients may reflect a linkage disequilibrium with genes coding for collagen synthesis.

Adult↗
PubMed1999

Clustering of ALS patients in central Italy due to the occurrence of the L84F SOD1 gene mutation.

OBJECTIVE: To study three new apparently unrelated Italian families with ALS and several sporadic ALS patients living in the same rural area. BACKGROUND: One Italian family with ALS carrying a superoxide dismutase 1 (SOD1) gene mutation (G41S) and no regional ALS clustering has been reported in Italy. METHODS: Genetic analysis was performed by automated and manual sequencing of the SOD1 gene in 13 family members and in 6 of 10 unrelated patients with sporadic cases of ALS living in the same area. The authors also determined SOD1 activity in erythrocytes and lymphocytes. RESULTS: The three families included a total of 28 affected members distributed over six generations. Despite a wide variability in age at onset and disease duration, the clinical pattern is uniform, with onset in the lower limbs, ascending progression, and predominant lower motor neuron involvement in all subjects. Generational anticipation is evident in the last two generations. All familial ALS patients and one of the six sporadic patients carry the same L84F missense point mutation in exon 4 of the SOD1 gene. SOD1 enzyme activity and SOD1 protein levels were not decreased significantly in the L84F patients. CONCLUSION: The ALS patients carrying the L84F mutation derive from a common ancestor. This mutation is responsible for ALS clustering in the area. The L84F mutation does not modify SOD1-specific activity.

Adult↗
PubMed1998

Fetal hearing.

Explore the source record for details and available documents.

Autoradiography↗
PubMed1998

The anterior subtemporal, medial transpetrosal approach to the upper basilar artery and ponto-mesencephalic junction.

OBJECTIVE: To describe and anatomically analyze the amount of exposure provided by an anterior subtemporal, medial transpetrosal approach to access the upper third of the basilar artery, ventral mesencephalon, pons, and posterior cavernous sinus. PATIENTS AND METHODS: The outcomes of six patients who underwent surgical treatment via the anterior subtemporal, medial transpetrosal approach at our institution during the past 2 years were reviewed. The series included three patients with subarachnoid hemorrhage from low-lying basilar apex aneurysms, one patient with intraparenchymal hemorrhage from a pontine cavernous malformation, and two patients with slowly progressive cranial neuropathies secondary to petroclival tumors. Thirty dry temporal bone specimens were also measured to quantify the height of petrous bone resection and added proximal basilar artery exposure. RESULTS: The surgical exposure was greatly enhanced in each instance, allowing each lesion to be treated in a straightforward manner with minimal added morbidity (one trochlear nerve palsy, one worsening of a preexistent oculomotor nerve palsy). Our subsequent morphometric analysis indicates that an additional 1 to 1.5 cm of basilar artery, clivus, and pons exposure over that of a standard anterior subtemporal approach is provided by this technique. CONCLUSION: This approach combines the wide view of the subtemporal approach with the more proximal exposure afforded by a medial petrosectomy. The widened visualization of the ventral pons and mesencephalon minimizes cranial nerve morbidity, greatly facilitates dissection of low-lying aneurysms, and provides proximal basilar artery control that would otherwise be obscured by the petrous ridge.

Adult↗
PubMed1998

Mutagenicity and clastogenicity of gas stove emissions in bacterial and plant tests.

The aim of this research was to study the gaseous and particulate emissions of genotoxic substances during cooking with two types of methane stoves (a new one and an old one). The particulates were sampled both with a cascade impactor air sampler and an impinger with ice trap and analyzed by two bacterial mutagenicity tests (Ames and Kado tests) and by HPLC for polycyclic aromatic hydrocarbons (PAH). Gaseous emissions were studied in situ using the Ames test, a clastogenicity plant test (Tradescantia-micronucleus test), and in an automated system for chemical analyses. Clear indirect mutagenicity was found only with the Kado test (TA98-S9) in extracts of particulates emitted from the old methane stove and collected with the impinger. Similar mutagenicity (TA98+S9) was also found for the finest fraction of particulates (<0.5 um) collected from both stoves. Gaseous emissions of both stoves caused clastogenicity in the in situ experiments with the Tradescantia-micronucleus test. The physico-chemical analyses of the emissions showed also the presence of very fine particulates and trace amounts of PAH. The exposure of these genotoxins could be particularly important for occupationally exposed individuals in homes and businesses and for susceptible subjects living indoors for long periods (infants, children, the sick, and the elderly).

Air Pollutants↗
PubMed1996

Detection of deglutition disorders after reconstructive laryngectomy. Clinical and radiological evaluations.

Subtotal reconstructive laryngectomy is an appropriate surgical procedure for intralaryngeal squamous cell carcinoma. After this surgery the functions of the larynx are greatly modified. These functions may be retained if at least one cricoaryténoid is preserved with good function. The aim of our study was to determine the recovery of swallowing in the late postoperative period and to establish the possible causes of dysphagia. 34 patients previously submitted to reconstructive laryngectomy were studied by clinical and endoscopical evaluation as well as videofluoroscopic examination. The results of our study confirm what has been reported by other authors, that is that the sphincter function greatly altered in the early postoperative period, is progressively restored, especially when both arytenoids are preserved. Videofluoroscopic examination frequently showed the asymptomatic false passage of liquid boluses.

Adult↗
PubMed1995

Varicella in immunocompetent children in the first two years of life: role of treatment with oral acyclovir. Italian Acyclovir-Chickenpox Study Group.

An open multicenter study has been carried out to evaluate efficacy and tolerability of oral acyclovir in the treatment of varicella in immunocompetent patients in the first two years of life. Fifty-three children aged 3-24 months received acyclovir at 80 mg/Kg/day in four divided doses for 4 to 6 days; 24 of them were treated in the first 24 hours following disease onset, while the remaining 29 patients were enrolled within 48 hours. The assessment of evolution of disease signs and symptoms showed a rapid resolution of fever, itching and other constitutional symptoms, with interruption of vesicle formation and acceleration of cutaneous healing processes. No statistically significant differences have been demonstrated as to disease progression between patients treated in the first 24 hours, when compared with subjects receiving acyclovir in the following 24 hours. Acyclovir confirmed its excellent clinical and laboratory safety profile. By acting favorably on both the duration and severity of disease signs and symptoms, acyclovir treatment should be recommended in young children and infants with varicella, since a higher incidence of severe and complicated disease has been observed in these patient groups.

Acyclovir↗
PubMed1995

Increase of serum copper concentration in Löfgren syndrome.

Chest X ray showing bilateral hilar adenopathies of the mediastinum associated with erythema nodosum suggests the diagnosis of Löfgren syndrome rather than the presence of a lymphoproliferative disorder. However, the occasional finding of high serum levels of copper can induce diagnostic doubts since serum copper increase is an index of lymphoproliferative disorders, particularly of Hodgkin's disease. We observed four patients with Löfgren syndrome presenting with fever, arthralgies, bilateral hilar adenopathies of the mediastinum and erythema nodosum. All patients underwent whole staging for sarcoidosis and serum copper levels were measured. In all cases clinical and instrumental data allowed the diagnosis of sarcoidosis and in all the patients we found high levels of serum copper with an average of 34.8 mumol/L (30.7-39.4) at the onset of the disease. Three months later, the sarcoid process spontaneously remitted and the serum copper levels returned to normal range. Although the finding of an increase of serum copper in patients with mediastinal adenopathies is usually indicative of a lymphoproliferative disorder (Hodgkin's disease), our data suggest that its increase can be related also to non neoplastic adenopathies of the mediastinum, including sarcoidosis.

Adult↗
PubMed1992

A case of Merkel-cell carcinoma metastatic to the tonsil.

Metastatic tumours are rare in the tonsil. We describe a 69-year-old male patient who had previously undergone a resection of a Merkel-cell tumour of the left forearm and subsequently presented with a left tonsillar tumour. Biopsy revealed a metastatic Merkel-cell carcinoma. Our patient is the first described case of Merkel-cell carcinoma metastasizing to the tonsil. The clinical and histopathological picture of this rare tumour is presented, along with a review of literature.

Aged↗
PubMed1986

Six variants of HLA-B27 identified by isoelectric focusing.

Six variant forms of HLA-B27 were identified among 68 unrelated B27-positive donors by isoelectric focusing (IEF) gel analysis. Each of the six IEF variants was distinguished by charge heterogeneity of desialated B27 heavy chains immunoprecipitated with specific monoclonal antibody (MAb). Charge differences varied from single to several charge units, indicating that these variants may have substantially different amino acid compositions. Informative family study showed that three B27 variant molecules were genetically determined. The uniqueness of these variant molecules was also demonstrable using a panel of alloantisera and MAbs recognizing B27-associated epitopes. Six distinct serological reactivity patterns were observed. Five of these serological patterns correlated with four of the IEF-defined variants, two of these patterns being associated with one IEF variant form. The sixth serological pattern was shared by the remaining two IEF variants. Combining the results of the electrophoretic and serological analyses, it is apparent that there are more than six structural variants within the B27 alloantigen family. Some B27 variant forms were found only in individuals of particular racial origin, indicating that unique genetic variations might occur in different racial groups. In a preliminary analysis of patients with ankylosing spondylitis, no apparent correlation was observed between any specific B27 variants and disease susceptibility.

Gene Frequency↗
PubMed1986

Evolution of HLA class I epitopes defined by murine monoclonal antibodies: distribution in macaques.

Murine anti-HLA monoclonal antibodies (MoAbs) to monomorphic and polymorphic epitopes were compared for their reactivity in humans vs. pigtailed macaques (Macaca nemestrina). Five MoAbs to monomorphic class I epitopes in humans displayed distinct patterns in macaques: two were unreactive, one reacted with 93% of animals tested, another with 17%, and one with only 8% of animals tested. Thus, epitopes that are monomorphic in one species can be highly polymorphic in another. Most of the 23 MoAbs (91%) against polymorphic epitopes in humans also detected polymorphisms in macaques. The epitopes detected by MoAbs could be divided roughly into two groups: epitopes that were expressed at the same frequency in both species, i.e., monomorphic, public, or private epitopes in both species, or epitopes that had quite different expression in the two species, e.g., a "public" epitope in one species expressed as a "private" epitope in the other. The genes encoding some of these polymorphisms were shown to segregate in families and thus some anti-HLA MoAbs are useful typing reagents for macaques. Two MoAbs thought to detect the same specificity in humans were found to react in macaques with different animals. Thus, reactivity patterns of anti-HLA class I MoAbs in primate populations enabled MoAbs to closely associated epitopes to be distinguished.

Animals↗
PubMed1986

Further studies on the epitopes of HLA-B7 defined by murine monoclonal antibodies.

Monoclonal antibodies reactive with polymorphic epitopes of HLA-B7 were analyzed by direct and indirect cytotoxicity assays on established panels of HLA typed lymphocytes. This permitted further refinement of their specificity and the identification of various novel reactions. The topographic relationship of polymorphic epitopes on the surface of the B7 molecule was assessed with various serological assays using cell surface B7 or papain solubilized B7 as the antigenic target. These studies focused on monoclonal antibodies recognizing B27 and B7. The results, in combination with those of previously published studies, are used to provide a current assessment of the epitope map of HLA-B7 as defined with mouse monoclonal antibodies. This is compared to the results obtained with alloantisera.

Animals↗
PubMed1985

Electrophoretic variation between class II molecules expressed on HLA-DRw8 homozygous typing cells reveals multiple distinct haplotypes.

Two-dimensional (2D) gel electrophoresis of immunoprecipitated HLA-DR antigens from eight homozygous typing cells (HTC) expressing the HLA-DRw8 specificity revealed a clustering of polymorphic beta chain patterns into distinct electrophoretic variants. The variant patterns correlate with three discrete HLA-D clusters that are defined in the mixed leukocyte culture reaction (MLR) using DRw8-positive HTC. These HLA-D clusters have been provisionally designated Dw"8.1", detected primarily in Caucasoids, Dw"8.2", detected primarily in American Indians, and Dw"8.3", detected predominantly in Orientals. All three HLA-Dw"8.1" cell lines express a single DR-locus product as defined by immunoprecipitation with a DR-specific monoclonal antibody, P4.1. This DR beta chain is identical among the Dw"8.1" cell lines and different from the DR beta chains of the Dw"8.2" and Dw"8.3" cell lines. Two separate Dw"8.2" HTC express a shared DR beta chain that is slightly more basic than the 8.1 DR molecule; interestingly, one of these lines also expresses an additional DR-like beta chain not found in the other cells. Thus, the two lines defining the Dw"8.2" cluster share one distinct class II molecule, but differ in another and therefore are not biochemically HLA-identical. Cells from the Dw"8.3" cluster are likewise distinct from all other Dw8 clusters. One additional DRw8-positive HTC has been analyzed and found to be distinct from the Dw"8.1", "8.2" and "8.3" clusters by both MLR and 2D gels. Immunoprecipitates using monoclonal antibody 1B5 [anti-DR and anti-DQ(DS)] identify additional polymorphic class II variants among the cell lines tested. These data indicate that HLA-DRw8 is a public serologic specificity present on class II molecules expressed on multiple distinct haplotypes. These haplotypes differ from each other in expression of polymorphic class II molecules encoded by at least two HLA loci. They also differ in HLA-D, even though they all type as HLA-DRw8 homozygous. In Dw"8.2", variation in expressed beta chains is not reflected in variation in HLA-D, indicating that MLR, as well as serologic typing, does not detect the full degree of allelic polymorphism within HLA.

Antibodies, Monoclonal↗
PubMed1985

A monoclonal antibody recognizing a determinant shared by HLA-A2 and HLA-Aw69 (A28* variant).

A cytotoxic murine monoclonal antibody, designated P5.1, was tested against 613 unrelated donors and found to react with 401 who were positive for HLA-A2 (sensitivity = 100%) and with 8 of 82 positive for HLA-A28. The latter split of A28 corresponds to the "A28* variant" that in the Ninth International Histocompatibility Workshop (9WS) was designated Aw69(28*). The epitope recognized by antibody P5.1 is distinct from the alloantisera-defined determinants that characterize HLA-A2 and A28. Immunoprecipitation of specific antigens with selected monoclonal antibodies and isoelectric focusing gel electrophoresis demonstrated that A2, Aw68(28) and Aw69(28*) are distinct polypeptides. Thus, the A2-A28 antigen family consists of at least three different alleles definable using alloantiserums specific for A2 and A28, and monoclonal antibodies such as P5.1 recognizing the A2,Aw-69(28*)-epitope.

Antibodies, Monoclonal↗
PubMed1984

The HLA-DR4 family of haplotypes consists of series of distinct DR and DS molecules.

Among DR4-associated HLA-D antigens, distinct and consistent structural variations were found for the products of two human "Ia-like" loci, DR and DS. Analysis of neuraminidase-treated immunoprecipitated DR molecules from 15 HLA-DR4-associated HLA-D homozygous B-lymphoblastoid cell lines by two dimensional polyacrylamide gel electrophoresis identified five distinct DR beta chains. In addition, gel analysis of immunoprecipitated DS molecules identified three distinct DS beta chains. Altogether, five distinct DR4 haplotypes were defined according to the observed structural diversity of the DR and DS beta chains. These gene products presumably contribute the dominant polymorphisms recognized by T cells in mixed lymphocyte reaction (MLR). Thus, these studies indicate that the serologic specificity known as HLA-DR4 is not a single haplotype, but a determinant present on products of individual loci arrayed into distinctly different haplotypes. These findings suggest that distinct products of individual loci, rather than conventional HLA specificities defined by alloimmune sera, may represent the genetic markers relevant to HLA-D/DR associated diseases.

Antibodies, Monoclonal↗
PubMed1984

Multiple Ia-like molecules characterize HLA-DR2-associated haplotypes which differ in HLA-D.

Two-dimensional gel electrophoresis of immunoprecipitated human Ia-like molecules was used to investigate the structural relationship between HLA-D and HLA-DR2. Eight different lymphoblastoid lines derived from HLA-DR2-associated homozygous typing cells, representing five distinct HLA-D clusters, were compared. Two or three distinct beta chain molecules from DR-like loci were identified in the DR2 homozygous cell lines studied. Furthermore, one of these molecules was present in all lines tested, while the others were highly variable. The electrophoretic mobility of these variable DR-like molecules correlated very well with HLA-D typing studies, suggesting that the HLA-DR specificity and the HLA-D specificity on these DR2 cells may be present on separate, but related, molecules.

Alleles↗