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Biomedical subjects

A Bernardi

Publications and source records attributed to A Bernardi.

At least 55 records · Page 3Linked to original sources
PubMed1990

A rapid inhibition micro ELISA for detecting antibodies to Plasmodium falciparum sporozoites in human blood.

A sensitive and specific micro ELISA, named MONOPLATE ELISA, for the detection of antibodies against P. falciparum sporozoites was developed. It can be applied to many kinds of samples including serum, plasma, whole blood, eluted bloodspot and mosquito bloodmeal as well. The method makes use of a single microtiter plate and the chemically synthesized (Asn-Ala-Asn-Pro)20 (NANP20) antigen both as coating material and as competitive (binding) inhibitor in the samples. The specific value of each sample is obtained as the absorbance difference between the uninhibited and the fully inhibited sample. Using appropriate conditions, the results can be evaluated by simple visual inspection of the plate, without any instrument. A rapid procedure, where the incubation times for sample and conjugate are just 15 minutes, is also described. When unknown samples from a P. falciparum endemic area were tested, a close correlation was found between our results and those obtained with the only commercial ELISA kit now available (Sclavo S.p.A). For screening purposes, as many as 48 samples per plate can be tested by this method.

Amino Acid Sequence↗
PubMed1988

Transcription of the target is required for IS102 mediated deletions.

We have constructed several plasmids to test the specificity of target selection for IS102 associated deletions. We had previously shown that the cIII region of phage lambda is a target for IS102 mediated deletions and this region was therefore introduced in pSC101, where IS102 resides, in such a way that it was silent, transcribed or fully expressed. The deletion selection was provided by the galactokinase system. The results we have obtained show that transcription of the target region is required for deletion formation. The frequency of deletions in this target depends on its position along the transcript and is also influenced by translation. Implications of these results on the regional specificity of transposition are discussed.

Bacteriophage lambda↗
PubMed1988

Different substrates influence the expression of intermediate filaments and the deposition of basement membrane proteins.

A primary culture of serous cystadenocarcinoma of the ovary was used to study the expression of intermediate filament proteins and the deposition of basal lamina proteins. It was found that cells grown on type I and IV collagens or in collagen gels failed to express vimentin, which was readily demonstrable in cultures of the same cells grown on plastic or glass. Furthermore cells grown in collagen gels formed colonies demonstrating a cystic architecture. Unlike what is commonly observed on glass or plastic, where laminin and fibronectin are deposited as disorganized fibrils in the extracellular space, in or on collagen these proteins appear solely at the interface between the epithelial cells and matrix. The results suggest that the extracellular matrix influences the cytoskeletal organization of the intermediate filaments and determines cell polarity. They confirm that collagen substrates permit epithelial cell cultures to progress toward a more differentiated state.

Basement Membrane↗
PubMed1987

Role of replication in IS102-mediated deletion formation.

Intramolecular transposition produces replicon dissociation in a bireplicon; this reaction is homologous to the well-characterized IS-associated deletions in the case of a monoreplicon. However the frequencies at which these two reactions occur differ by a factor of more than 10(2) in favor of deletion formation. This raises the question of how these deletions occur. We show that the presence of a productive replication on the fragment to be deleted interferes with deletion formation. Our results also suggest that the deleted fragment is not degraded during deletion formation.

Chromosome Deletion↗
PubMed1987

Pollution episodes at Venice related to weather types: an analysis for a better predictability.

In order to obtain a rational strategy for the control and management of emissions from the industrial area of Venice, determination of the air quality is made from different perspectives. A source-receptor oriented approach shows a remarkable scatter of data due to the complex source field and variability of atmospheric conditions at a coastal site. As many pollution episodes are initiated by local diffusion potentials induced by the interaction between topographic irregularities (i.e. Alpine chain and Adriatic Sea) and the mesoscale atmospheric circulation system, a correlation between pollution events and synoptic conditions is made. Two periods of two years each were considered, the former characterized by very frequent, moderate episodes, the latter by more rare but potentially more severe episodes, although the emission rate was reduced. Four different criteria (i.e. weather types as classified by the U.K. Meteorological Office, by Borghi and Giuliacci, and by Urbani, and the passage of fronts) are considered and compared in order to describe the synoptic conditions and to make a reasonable prediction of the local dynamic climatology. A risk index (RI) is computed for each weather type. The U.K. classification appears to be the most suitable as it classifies the maximum number of synoptic maps and has the greatest spread of RI, thus making a more sound prediction. The analysis shows that the pollution episodes are associated with instability phenomena, i.e. passage of fronts or the onset of moderate to fresh winds, and not with stationary conditions. Also, the areal extension over which the highest pollution levels are recorded is related to particular weather types. The statistics of the meteorological weather types occurring during the pollution events give satisfactory results for some weather types, especially for those correlating highly or poorly with pollution events.

Air Pollution↗
PubMed1987

Expression of the monoclonal antibody-defined CAR-3 epitope on neoplastic and preneoplastic lesions of the colon mucosa.

The AR-3 monoclonal antibody, which defines the tumor-associated antigen CAR-3, was previously found to be able to discriminate between neoplastic cells in gastric, pancreatic, colonic, ovarian and endometrial carcinomas and their normal counterparts. In fact, it strongly reacts with carcinomatous cells at the level of both the glycocalix and the cytoplasm, while its reactivity with normal tissues is restricted to the glycocalix of few mucin-producing epithelial cells. We have now investigated the reactivity of this antibody with immunohistochemical techniques on a series of formalin-fixed paraffin-embedded specimens, from precancerous and cancerous lesions of the large bowel which were classified as adenomas with mild, moderate or severe dysplasia, adenomas with cancer and adenocarcinomas, respectively. It was found that the intensity and extent of the staining correlated with the degree of dysplasia and that the highest expression of the CAR-3 epitope was detectable in adenocarcinomas. Also the localization of the staining in the lesions displayed an increasingly complex pattern, going from linear in adenomas with mild dysplasia to a very strong intracytoplasmic and/or intraluminal expression in adenomas with severe dysplasia or adenocarcinomas.

Adenocarcinoma↗
PubMed1986

Intramolecular transposition of IS102.

It has been postulated that deletions mediated by transposable elements are intramolecular transposition events. An implication of this hypothesis is that the deleted fragment may be recovered if it is capable of autonomous replication. We report here the characterization of the products of intramolecular transposition of the element IS102 in bireplicons. We show that when two origins (ori's) (of pSC101 and R6-5) generate the same copy numbers, two dissociated replicons are recovered as well as the inversions. On the contrary, when two ori's (of pSC101 and pBR322) have different copy numbers, intramolecular transposition results essentially in inversions. However, the very low frequency (5 X 10(-8)) at which intramolecular transpositions in the bireplicons occurs, as compared to the single replicon (10(-4)), suggests that a complete transposition reaction may not be necessary to generate deletions.

Chromosome Deletion↗
PubMed1984

Complete sequence of pSC101.

We have completed the pSC101 sequence. The coding capacities of the newly sequenced regions show the presence of two large open reading frames close to the oriT region. Their size and localization suggest that these polypeptide chains could be involved in the transfer process of pSC101.

Base Sequence↗
PubMed1984

Atypical deletions generated by mutated IS102 elements.

The element IS102 potentially codes for two polypeptide chains. We have introduced several mutations in the larger one near the COOH terminus and determined the residual ability of the mutated elements to generate deletions in order to assign a role to this polypeptide chain. We show that in these elements, deletions still occur, although at a reduced level, but that in all cases examined so far the ends of the element are no longer recognized as the fixed endpoint of IS-mediated deletions, even though some other structural features of normal deletions formation are still present.

Bacteriophage lambda↗
PubMed1984

[Carcinoid of the gastrointestinal system (study of a clinical case)].

The authors describe a case of multiple carcinoid tumours of stomach, which arose on an atrophic chronic gastritis. The case was studied in strict equipe cooperation by physicians, surgeons, radiologists, anatomopathologists, and, subsequently, it was surgically treated through total extended gastrectomy.

APUD Cells↗
PubMed1981

Complete sequence of an IS element present in pSC101.

Recently a new insertion element (IS102)b ha been described in plasmid pSC101. We have determined its complete sequence: it consists of 1057 bp; 338 bp at one end are identical to those already determined for the kanamycin resistance transposon Tn903. It is not flanked by any direct repeat. Its coding capabilities are discussed, and compared to those of IS903.

Base Sequence↗