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A Cataldi

Publications and source records attributed to A Cataldi.

At least 55 records · Page 3Linked to original sources
PubMed2000

Aneurysm dissection of the extracranial internal carotid artery.

Aneurysm of the extracranial internal carotid artery is a rare event. This is a pathology with an elevated mortality of 70%. The most important etiologic factor is atherosclerosis. Here we report a case of surgically treated extracranial internal carotid artery (ICA) aneurysm. A 77-year-old man noticed a laterocervical pulsatile mass. Color Doppler ultrasonography revealed an ICA aneurysm related to a parietal thrombosis. The ICA aneurysm was confirmed by intra-arterial digital subtraction angiography, and cerebral computer tomography (CT) was negative. Surgical treatment reconstruction with the interposition of a part of the great saphenous vein was indicated. Exploration of the aneurysmatic wall revealed a posterolateral dissection. In this paper are discussed clinical and therapeutic implications.

Aged↗
PubMed2000

[Characterization of non-secreting adrenal nodules (incidentalomas): role of multiphasic spiral computerized tomography].

PURPOSE: To evaluate the diagnostic yield of multiphasic helical CT in the characterization of single non functioning adrenal nodules (incidentalomas) less than 50 mm in diameter. Emphasis was given to the possible replacement of unenhanced with delayed scans in cancer patients undergoing staging procedures. MATERIAL AND METHODS: Sixty patients with single adrenal nodules (30 of them neoplastic and 30 non-neoplastic) were examined with thin unenhanced scans (5 mm), early scans after administration of a contrast agent (120 mL at 2.5 mL/s with 60 s delay) and late scans (30 min delay). RESULTS: On both unenhanced and late scans a threshold could be selected on the Hounsfield unit scale which guaranteed absolute specificity in the characterization of adenomas (100% specificity) with very high sensitivity (93% at both scans): this threshold was 19 HU on unenhanced and of 41 HU on late scans. In contrast, at early delayed scanning the threshold which guaranteed 100% specificity was associated with negligible sensitivity (30%). The evaluation of lesion size had no diagnostic value, since the mean diameter of both benign and malignant nodules was of 25 mm. CONCLUSIONS: Late scans have diagnostic yield comparable to unenhanced scans: at the selected delay (30 min), benign lesions nearly always have lower attenuation values than malignant nodules and can be diagnosed with confidence when they exhibit mean attenuation values lower than 41.

Adenoma↗
PubMed1999

Antigenic characterization of mycobacteria from South American wild seals.

Tuberculosis-producing mycobacteria have been previously described in marine mammals (Cousins et al., 1990, 1993; Romano et al., 1995; Bernardelli et al., 1996). The strains belonged to the M. tuberculosis complex (M. tuberculosis, M. bovis, M. microti and M. africanum), but showed genetic and biochemical differences. The antigenic composition of mycobacteria isolated from wild seals was analyzed by Western blots, using antibodies against some selected antigens. The antigenic content was compared with that of M. bovis, M. tuberculosis and M. microti isolates. The lack of Hsp65 protein in supernatants suggested a low degree of cell lysis in the three-week cultures used. SOD, P27 lipoprotein, MPB64 and antigen 85 were observed in all the strains studied. The wild seal strains, as well as M. tuberculosis, did not produce MPB70 and MPB83. Only very weak bands of P36 antigen were observed in culture supernatants from wild seal mycobacteria. Summarizing, the antigenic composition of mycobacterial strains from wild seals is different from M. bovis strains.

Animals↗
PubMed1999

Twenty-four-hour variation in serum leptin in the elderly.

To investigate the possibility that the aging process may affect the diurnal variation in serum leptin in humans, serum leptin levels were measured by a sensitive radioimmunoassay method in 12 elderly (aged 72 to 87 years) and 10 middle-aged (35 to 50 years) lean male subjects. Fasting blood samples (4 mL) were drawn at 8:00 AM, and then every 4 hours until 10:00 PM and every 2 hours from 12:00 midnight to 8:00 AM of the next morning. Circadian rhythmicity analysis was performed using the cosinor method. In elderly subjects, serum leptin levels showed a significant diurnal rhythm, which was similar to that observed in controls. Single cosinor analysis showed a significant rhythm in eight of 12 elderly subjects and in all middle-aged subjects but one. Compared with middle-aged subjects, similar mesor mean values (7.8 +/- 1.0 v 8.1 +/- 0.8 ng/mL) but a decreased amplitude (1.4 +/- 0.3 v 2.3 +/- 0.2 ng/mL) and an earlier acrophase (11:56 PM v 2:04 AM) were observed in the elderly. The data demonstrate that the diurnal variation in serum leptin is generally preserved in the elderly. However, the amplitude of leptin diurnal excursion undergoes a reduction with advancing age. It can be speculated that the blunted diurnal variation in serum leptin observed in the elderly may result in an alteration of the afferent signal in the adipose tissue-central nervous system homeostatic loop.

Adult↗
PubMed1999

Distribution of IS900 restriction fragment length polymorphism types among animal Mycobacterium avium subsp. paratuberculosis isolates from Argentina and Europe.

Sixty-one Mycobacterium avium subsp. paratuberculosis isolates from cattle and deer from the Buenos Aires province, an important livestock region in Argentina, were typed by restriction fragment length polymorphisms (RFLP) analysis based on IS900. Four different RFLP patterns (designated 'A', 'B', 'C' and 'E') were identified in BstEII digests of genomic DNA. The most frequently observed type, pattern 'A', was found in 46 isolates (75%). The second, pattern 'E', included 8 isolates (13%), while the third, pattern 'B', included 6 isolates (10%). Pattern 'C' was found for only one isolate. All of the deer isolates were classified as pattern 'A', while cattle isolates represented all four RFLP patterns. Twenty-one isolates representing the four different BstEII-RFLP patterns were digested with PstI. Twenty isolates showed identical PstI-RFLP pattern. BstEII-RFLP patterns from Argentine cattle and deer were compared with patterns found in cattle, goat, deer, rabbit, and human isolates from Europe. The most common pattern in Argentina, pattern 'A', was identical to a less frequently occurring pattern R9 (C17) from Europe. The other Argentine patterns 'B', 'C' and 'E', were not found in the Europe. These results indicate that the distribution of M. avium subsp. paratuberculosis genotypes in the Buenos Aires province of Argentina is different from that found in Europe.

Animals↗
PubMed1999

Molecular characterization of mycobacteria isolated from seals.

Tuberculosis (TB) was diagnosed in 10 seals from three species (Arctocephalus australis, Arctocephalus tropicalis and Otaria flavescens) found in South America. The mycobacteria isolated from these cases belonged to the Mycobacterium tuberculosis complex, as determined by RFLP using an IS6110 probe, spoligotyping, analysis of the 16S rRNA gene sequence and by PCR-restriction analysis of hsp65. Polymorphisms in gyrA, katG, oxyR and pncA were investigated in some of the isolates, as well as the presence of the MPB70 antigen. The insertion sequence IS6110 was present in three to seven copies in the genome of the mycobacteria isolated from seals. Using the IS6110 probe, six patterns (designated A, B, C, D, E and F) were identified from 10 different isolates. Patterns A and B were found for the mycobacteria isolated from two and four seals, respectively, indicating an epidemiological relationship between isolates grouped according to their IS6110 RFLP. The mycobacteria isolated from seals shared the majority of their IS6110 DNA-containing restriction fragments, and nine isolates had an identical spoligotype; only one isolate showed a minor difference in its spoligotype. In addition, none of these spoligotypes were found in other M. tuberculosis complex strains. These results suggest that the isolates from seals constitute a unique group of closely related strains. The mycobacteria isolated from seals showed polymorphisms at gyrA codon 95 and katG codon 463, as do group 1 M. tuberculosis, and M. bovis. Group 1 mycobacteria are associated with cluster cases. The spoligotypes found in the mycobacteria isolated from seals lack spacers 39-43, as does M. bovis, but the MPB70 antigen, which is highly expressed in M. bovis and minimally expressed in M. tuberculosis, was not detected in these mycobacteria. The mycobacteria isolated from seals also showed oxyR and pncA polymorphisms specific to M. tuberculosis. In conclusion, the mycobacteria that cause TB in seals in the South-Western Atlantic are a related group, and based on the combination of genetic characteristics, belong to a unique genotypic group within the M. tuberculosis complex.

Animals↗
PubMed1999

Usefulness of spoligotyping in molecular epidemiology of Mycobacterium bovis-related infections in South America.

Two hundred twenty-four Mycobacterium bovis isolates, mainly from South American countries, were typed by spoligotyping, and 41 different spoligotypes were identified. A total of 202 M. bovis isolates (90%) were grouped into 19 different clusters. The largest cluster contained 96 isolates (42.8%) on the basis of the most frequently observed spoligotype, spoligotype 34. Nineteen M. bovis isolates from humans in Argentina had spoligotypes and polymorphic GC-rich repetitive sequence (PGRS) types that represented the most common types found among isolates from cattle. All five isolates from Uruguay and three of the six isolates from Paraguay had spoligotypes that were also detected for isolates from Argentina. The spoligotypes of isolates from Brazil, Costa Rica, and Mexico and of some of the isolates from Paraguay could not be found in Argentina. A total of 154 M. bovis isolates were selected in order to compare the discriminative power of spoligotyping and restriction fragment length polymorphism (RFLP) analysis with direct repeat (DR) and PGRS probes. By spoligotyping, 31 different types were found, while AluI-digested DR probe-associated RFLP analysis identified 42 types, and RFLP analysis with the PGRS probe also detected 42 types; these were partly independent of the DR types. By combining the results obtained by spoligotyping and by RFLP analysis with the DR and PGRS probes, 88 different types were obtained. Although the differentiation of M. bovis by spoligotyping was less discriminatory than differentiation by RFLP analysis with the DR and PGRS probes, spoligotyping is easier to perform and its results are easier to interpret. Therefore, for the purpose of typing of M. bovis isolates, spoligotyping could be performed first and the isolates could be grouped into clusters and then analyzed by RFLP analysis with the DR and PGRS probes.

Animals↗
PubMed1999

The IS6110 restriction fragment length polymorphism in particular multidrug-resistant Mycobacterium tuberculosis strains may evolve too fast for reliable use in outbreak investigation.

To study possible nosocomial transmission of multidrug-resistant (MDR) Mycobacterium tuberculosis, strain types and other information on 24, mostly human immunodeficiency virus-positive patients, were collected. Isolates from 11 patients had identical IS6110 restriction fragment length polymorphism (RFLP) patterns as well as spoligotype patterns and resistance profiles. Noticeably, nine other isolates from related cases also exhibited identical spoligotypes but slightly different RFLP patterns. These results indicate that for some MDR strains, the evolutionary clock of IS6110 RFLP may run too fast for reliable interpretation of strain typing results over a period of a few years.

AIDS-Related Opportunistic Infections↗
PubMed1999

Amplification of a 500-base-pair fragment from cultured isolates of Mycobacterium bovis.

The presence of a 500-bp fragment which amplifies a region from the genome of Mycobacterium bovis (J. G. Rodriguez, G. A. Meija, P. Del Portillo, M. E. Patarroyo, and L. A. Murillo, Microbiology 141:2131-2138, 1995) was evaluated by carrying out PCR on 121 M. bovis isolates. The M. bovis strains, previously characterized by culture and biochemical tests, were isolated from cattle in different regions of Argentina, Mexico, and Colombia. Four additional strains isolated from sea lions that belong to the M. tuberculosis complex were also included in the study. All of the isolates tested were PCR positive, rendering the expected 500-bp band and giving a correlation of 100% with previous microbiological characterization. Southern blot analysis revealed a common band of 1, 800 bp and a polymorphic high-molecular-mass hybridization pattern. The results show that this assay may be useful for diagnosis and identification of M. bovis in cattle.

Animals↗
PubMed1999

Immunocytochemical localization of phospholipase C isozymes in cord blood and adult T-lymphocytes.

The response of T-cells to peptide antigen plus major histocompatibility complex (MHC) consists of a series of cellular events collectively called T-cell activation. An essential component of this pathway is phospholipase C (PLC)gamma1, whose hydrolytic activity increases rapidly after binding of ligands to the T-cell receptor (TCR) and consequent activation of tyrosine kinases. Recent studies also suggest a GTP binding protein-dependent activation of PLCbeta during the early steps of T-cell activation. On the basis of these findings, we first checked the expression of PLC isoforms by Western blotting and by confocal and electron microscopy techniques, and then we looked for the phosphoinositide breakdown induced by CD3 engagement in cord and adult T-lymphocytes. Our results indicated that PLCbeta1 was almost exclusively expressed in cord T-cells, whereas PLCbeta2 was more strongly represented in the adult. The amount of PLCgamma1 was found to be larger in the adult than in cord cells. No significant differences were found in PLCgamma2 and delta2 expression. PLCdelta1 was scarcely detectable. On CD3 stimulation, adult lymphocytes gave rise, as expected, to a dramatic increase in phosphoinositide breakdown, whereas in cord cells this response was scarcely detected. These results indicate that a shift in PLC expression occurs in the postnatal period and that this change is associated with induction of the capability to respond to CD3 engagement with phosphoinositide hydrolysis.

Adult↗
PubMed1998

Novel evidence of expression and activity of ecto-phospholipase C gamma1 in human T lymphocytes.

Although much is known about the intracellular phospholipase C (PLC) specific for inositol phospholipids, few data are available about the presence of a less common PLC at the external side of the membrane bilayer of some cell types. This ectoenzyme seems to play particular roles in cellular function by hydrolyzing inositol lipids located on the outer leaflet of the plasma membrane. Here, we provide the first evidence that peripheral T lymphocytes express a discrete level of a PLCgamma1 at the outer leaflet of the plasma membrane. Flow cytometry showed that the PLCgamma1-positive (PLCgamma1(+)) cells (approximately 37%) were CD8(+) and CD45RA+. Biochemical evidence indicated that (1) this ectoenzyme displays a mass similar to the cytoplasmic form, (2) it is phosphorylated on tyrosine residues, and (3) its activity is Ca2+-dependent. In addition, this enzyme appeared to be correlated with the proliferative state of the cell, since stimulation with phytohemagglutinin (PHA) downregulated both its expression and activity, which were restored by treatment with an antiproliferative agent like natural interferon beta. Moreover, the different kinetics of formation of its hydrolytic products, inositol 1 phosphate and inositol 1:2 cyclic phosphate (Ins(1)P and Ins(1:2 cycl)P), formed upon incubation of the lymphocytes with [3H]-lyso-phosphatidylinositol (PI), allow the hypothesis of a selective involvement of the two inositol phosphates in the mechanisms regulating the metabolism of particular T-lymphocyte subsets.

Adult↗
PubMed1998

Molecular epidemiology of Mycobacterium bovis isolates from South America.

One hundred seventy-eight isolates of Mycobacterium bovis were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the direct repeat element (DR) and the polymorphic GC-rich repeat sequence (PGRS) as probes. By combining the patterns generated by the two repeat DNA elements, 93 different patterns were observed. One hundred-one isolates were grouped in clusters, which include 25 different clusters. One pattern was the most frequently observed, clustering 18.5% of isolates. It was only found in the Center and northeast regions of Argentina and in one isolate from Paraguay. The isolates from Brazil analyzed here presented exclusive patterns (only found in a particular region). The number of exclusive patterns was high in all argentine regions: northeast 78%, center 81%, and Buenos Aires 81%.

Animals↗
PubMed1998

Somatostatin release in response to glucose is impaired in chronic renal failure.

In order to evaluate somatostatin (SRIH) secretion in uremia, plasma SRIH concentrations were determined in basal conditions and after an oral glucose tolerance test (OGTT) in 14 non-dialysed patients with chronic renal failure (CRF), seven of whom had normal glucose tolerance (NGT) and seven impaired glucose tolerance (IGT). Plasma insulin, C-peptide and glucagon and blood glucose concentrations were also evaluated. The results were compared with those obtained in a group of age- and sex-matched normal subjects. In CRF patients, plasma SRIH fasting values (8.6 +/- 0.6 and 7.8 +/- 0.6 pmol/L in NGT and IGT patients, respectively) were comparable to those recorded in controls (7.7 +/- 0.5 pmol/L). SRIH response to OGTT, evaluated as area under curves (AUC) above basal, was similar in both groups of CRF patients (412.9 +/- 84.5 and 415.6 +/- 51.9 pmol/L per min), and significantly lower than in controls (660.1 +/- 58.5 pmol/L per min). Data indicate that chronic uremia induces a loss of SRIH secretory cell responsiveness to glucose. A possible effect of impaired SRIH secretion on glucose metabolism in CRF is discussed.

Adult↗
PubMed1998

Immunocytochemical detection of phosphatidylinositol 3 kinase in Burkitt lymphoma cells.

PI 3-kinase, an enzyme responsible for the phosphorylation of the D3 position of the inositol ring of phosphatidylinositol (PI), is recognized to be involved in the regulation of many cellular processes such as mitogenic signalling, inhibition of apoptosis, intracellular vesicle trafficking/secretion, regulation of actin and integrin functions and regulation of protein kinases induced by tumour necrosis factor, oncoproteins and ultraviolet light. Here we report the subcellular distribution and the phosphorylative pattern of p85 alpha subunit of PI 3-kinase in Burkitt lymphoma cells exposed to R interferon alpha treatment. Immunocytochemical analysis of this enzyme, performed by confocal microscopy, revealed an increased expression of this protein at cytoplasmic level after 90 min of interferon alpha treatment. Western blotting analyses performed on nuclear and cytoplasmic fractions confirmed the overexpression found by confocal microscopy at cytoplasmic level in the 90 min interferon alpha treated cells still persisting in the 24 hr treated samples. Such an overexpression was paralleled by an increase of tyrosine phosphorylation both at cytoplasmic and nuclear level suggesting that an enhanced requirement for cytoplasmic expression and phosphorylation of PI 3-kinase might be necessary to the cell for regulating some cytoplasmic-nuclear cross talk involved in the control of Burkitt lymphoma cell metabolism following interferon alpha treatment.

Animals↗
PubMed1997

Shift of DNA polymerase alpha nuclear distribution and activity in apoptotic human leukaemia cells.

The changes in the distribution of DNA polymerase alpha in nuclei from HL-60 cells treated with Methotrexate (MTX) for up to 15 hr. were checked by means of both confocal analysis and electron microscopy analysis. The results provided evidence that, relative to controls, in the MTX treated cells the enzyme undergoes a topographical rearrangement throughout the nucleus, showing a pattern of distribution which calls to mind the nuclear matrix structure. The "in vitro" analysis of DNA polymerases alpha, beta, and gamma activities revealed that, in nuclei from control cells, DNA polymerase alpha was the principal DNA polymerase driving this "in vitro" system, while after 15 hr. of MTX treatment its activity was largely decreased and replaced by DNA polymerase beta, which is believed to be associated with DNA repair. Taken together, these results suggest that among the intracellular processes elicited by MTX-induced apoptosis in HL60 cells, the redistribution of DNA polymerase alpha and the stimulation of DNA polymerase beta activity might represent an extreme attempt of the cell to preserve the replicative machinery during fragmentation and chromatin margination.

Antimetabolites, Antineoplastic↗