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J C de Oliveira

Publications and source records attributed to J C de Oliveira.

13 recordsLinked to original sources
PubMed2001

A comparison of prototype compound parabolic collector-reactors (CPC) on the road to SOLARDETOX technology.

Solar photocatalytic detoxification of non-biodegradable chlorinated hydrocarbon solvents (NBCS) is carried out in different concentrating and non concentrating devices using TiO2 as a photocatalyst fixed on the inner surface of the reaction tubes or as a slurry catalyst which has to be removed from the treated water. The reaction is most effective using 200 mg/l of TiO2 as a slurry in a non concentrating CPC reactor. The concentrating parabolic trough reactor has a poor activity because of its minor irradiated reactor surface. Catalyst coated glass tubes are less efficient then the used slurry catalyst. Their advantage is that no catalyst has not to be removed from the treated water and there is no loss of activity during treatment. Yet their physical stability is not sufficient to be competitive to the slurry catalyst. Nevertheless the degradation results are very promising and will possibly lead to commercial applications of this technology.

Catalysis↗
PubMed1999

Identification of an ancestral resistance gene cluster involved in the coevolution process between Phaseolus vulgaris and its fungal pathogen Colletotrichum lindemuthianum.

The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters have shed light on the molecular evolution of R genes. However, up to now, no attempt has been made to correlate this molecular evolution with the host-pathogen coevolution process at the population level. Cross-inoculations were carried out between 26 strains of the fungal pathogen Colletotrichum lindemuthianum and 48 Phaseolus vulgaris plants collected in the three centers of diversity of the host species. A high level of diversity for resistance against the pathogen was revealed. Most of the resistance specificities were overcome in sympatric situations, indicating an adaptation of the pathogen to the local host. In contrast, plants were generally resistant to allopatric strains, suggesting that R genes that were efficient against exotic strains but had been overcome locally were maintained in the plant genome. These results indicated that coevolution processes between the two protagonists led to a differentiation for resistance in the three centers of diversity of the host. To improve our understanding of the molecular evolution of these different specificities, a recombinant inbred (RI) population derived from two representative genotypes of the Andean (JaloEEP558) and Mesoamerican (BAT93) gene pools was used to map anthracnose specificities. A gene cluster comprising both Andean (Co-y; Co-z) and Mesoamerican (Co-9) host resistance specificities was identified, suggesting that this locus existed prior to the separation of the two major gene pools of P. vulgaris. Molecular analysis revealed a high level of complexity at this locus. It harbors 11 restriction fragment length polymorphisms when R gene analog (RGA) clones are used. The relationship between the coevolution process and diversification of resistance specificities at resistance gene clusters is discussed.

Amino Acid Sequence↗
PubMed1997

Protein factors in Blastocladiella emersonii cell extracts recognize similar sequence elements in the promoters of the genes encoding cAMP-dependent protein kinase subunits.

Blastocladiella emersonii contains a single cAMP-dependent protein kinase (PKA), which is similar to the mammalian type II isoforms. Its activity is regulated during development by changes in the levels of the catalytic (C) and regulatory (R) subunits, which occur in parallel with changes in levels of the corresponding mRNAs, suggesting coordinate transcriptional control of the expression of both subunits. Both R and C mRNA levels are low in vegetative cells, rise sharply during sporulation and decrease to basal levels again after germination. To investigate sequence elements common to both Blastocladiella R and C gene promoters, which might be involved in the coordinate regulation of these genes, their 5'-flanking regions were analyzed by gel mobility shift and DNase I footprinting assays. We determined that different DNA-protein complexes are generated when fragments of the R and C gene promoters are incubated with extracts from cells expressing (sporulating cells) or not expressing (vegetative cells) both subunits, and competition experiments suggested that similar protein factors bind to both promoters. DNase I footprinting experiments have indicated that a sequence common to both R and C promoters, and similar to mammalian E-boxes, binds factors present in extracts from vegetative and sporulating cells, whereas sequences flanking the E-boxes in both promoters showed a change in the pattern of DNase I digestion only when the vegetative cell extract was used. This result suggests that the composition of the protein complexes binding to these regions changes during sporulation.

Base Sequence↗
PubMed1994

Cloning and characterization of the gene for the catalytic subunit of cAMP-dependent protein kinase in the aquatic fungus Blastocladiella emersonii.

We have isolated and characterized cDNA and genomic DNA clones encoding the catalytic subunit (C) of cAMP-dependent protein kinase in the aquatic fungus Blastocladiella emersonii. The C-subunit amino acid sequence derived from the nucleotide sequence predicts a basic polypeptide of 424 residues, excluding the initiator methionine, which by amino-terminal sequence analysis has been shown to be absent from the mature protein. The Blastocladiella C presents a 70-amino-acid extension at the amino terminus, when aligned to the mouse C alpha subunit, being one of the largest C subunits already characterized. The B. emersonii C-gene-coding region is interrupted by three introns, ranging in size over 57-69 bp. The positions of the introns are quite different from those found in other species, suggesting a considerable amount of evolutionary drift in the gene structure. The 5'-flanking region lacks recognizable TATA or CCAAT sequences, is remarkably high in GC content (70%), and primer extension experiments indicate that transcription initiates from multiple sites. Several sequence motifs were identified in the promoter region which could be involved in the developmental control of this gene.

Amino Acid Sequence↗
PubMed1992

Coordinate pretranslational control of cAMP-dependent protein kinase subunit expression during development in the water mold Blastocladiella emersonii.

The aquatic fungus Blastocladiella emersonii provides a system for studying the regulation of expression of regulatory (R) and catalytic (C) subunits of cAMP-dependent protein kinase (PKA). Blastocladiella cells contain a single PKA with properties very similar to type II kinases of mammalian tissues. During development cAMP-dependent protein kinase activity and its associated cAMP-binding activity change drastically. We have previously shown that the increase in cAMP-binding activity during sporulation is due to de novo synthesis of R subunit and to an increase in the translatable mRNA coding for R (Marques et al., Eur. J. Biochem. 178, 803, 1989). In the present work we have continued these studies to investigate the mechanism by which the changes in the level of kinase activity take place. The C subunit of Blastocladiella has been purified; antiserum has been raised against it and used to determine amounts of C subunit throughout the fungus' life cycle. A sharp increase in C subunit content occurs during sporulation and peaks at the zoospore stage. Northern blot analyses, using Blastocladiella C and R cDNA probes, have shown that the levels of C and R mRNAs parallel their intracellular protein concentrations. These results indicate a coordinate pretranslational control for C and R subunit expression during differentiation in Blastocladiella.

Blastocladiella↗
PubMed1987

Anterior plate fixation of traumatic lesions of the lower cervical spine.

Anterior fixation of traumatic lesions of the cervical spine with a plate and bone grafts has been proved to be a safe procedure. Patients without neurologic lesions can be out of hospital 7 to 10 days after the accident. Even in cases of serious neurologic lesions, rehabilitation and nursing of the patient can be improved. Although the method can be used in any case of traumatic instability of the cervical spine, the main indications are teardrop fractures not reduced by skull traction, severe wedging fractures, severe extension injuries, and any lesion with compression in the anterior part of the canal. Old kyphotic blocks or unreduced fracture-dislocations, with anterior bone and fibrous callus, can be treated with this method better than with any other technique. Forty patients were successfully operated on without major complications. Stability and alignment of the spine was achieved in all cases.

Bone Plates↗
PubMedDate not supplied

Anterior reduction of interlocking facets in the lower cervical spine.

Twelve patients with locked facets of the lower cervical spine were surgically treated through an anterior approach. The interlocking was bilateral in 2 cases and unilateral in 10; in all patients, skull traction failed to obtain the reduction. The technique of anterior reduction is described, with particular attention to the importance of complete removal of the disc before insertion of the distractor. Reduction was easily and safely achieved in all cases, and no significant complication occurred.

Adult↗
PubMedDate not supplied

[Epidemiologic markers of Salmonella typhimurium and Salmonella agona].

Among S. typhimurium and S. agona strains isolated during the period from 1971 to 1987, the biotypes, colicine types and resistance patterns were determined for 734 S. typhimurium and 631 S. agona strains. Among 734 S. typhimurium strains 65 biotypes were disclosed with prevalence of biotypes 1a (28.34%), 1b (29.84%) and 9 bi (18.28). Concerning S. agona, the biotype 1a represented by 87.16%, was the commonest clone among our strains. Although colicine typing added little information to characterize these serotypes, it should be usefull when applied in epidemiological study of outbreaks. It was observed multiply antimicrobial resistance mainly among human strains, particularly from nosocomial origins.

Animals↗