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Biomedical subjects

S Moreno

Publications and source records attributed to S Moreno.

At least 217 records · Page 12Linked to original sources

Clinical presentation of Bacillus Calmette-Guérin infections in patients with immunodeficiency syndromes.

Nine children with immunodeficiency syndromes who developed persistent or disseminated Bacillus Calmette-Guérin (BCG) infections after BCG vaccination at birth were observed in Santiago, Chile, over a period of 10 years. This represents a risk for persistent or disseminated BCG infections of 3.4/1,000,000 vaccinated newborns. This may closely reflect the incidence of severe combined immunodeficiency syndromes, cellular immunodeficiency syndromes and chronic granulomatous disease in the study area. The clinical presentation and course of the infection varied considerably depending on the underlying immunodeficiency syndrome. Two patients with severe combined immunodeficiency presented with cutaneous nodules in the absence of any local reaction at the site of BCG vaccination. Both patients died of disseminated BCG infection within the first year of life. Four patients with cellular immunodeficiency syndromes presented with regional lymphadenitis resistant to treatment after the fifth month of life. Three of these patients had specific unresponsiveness to tuberculin and survived from 5 to 6 years of age. Two boys with X-linked chronic granulomatous disease presented with regional lymphadenitis in the first 3 months of life. A girl with autosomal recessive chronic granulomatous disease presented at 18 months of age with regional lymphadenitis. All three patients with chronic granulomatous disease had positive tuberculin reactions and died from infections other than BCG.

BCG Vaccine↗

Chromosomal involvement secondary to -22 in human meningiomas.

Cytogenetic analyses have been performed on cultures in vitro from 32 human meningiomas, seeking chromosomal anomalies in addition to characteristic monosomy 22. Eight cases showed stem lines with normal karyotype, whereas, monosomy 22 as the only chromosomal deviation characterized the stem line of ten tumors. In 14 samples stem lines or modal numbers displaying numerical deviations (other than -22) and/or structural rearrangements were found. A hyperdiploid modal number was present in three, whereas, it was hypodiploid in the remainder. Numerical deviations in these tumors involved mainly #14 by losses, and also #22; recurrent structural rearrangements involving 1p and 11p were also characteristic features. Thus, these results could imply that involvement of #14, 1p, and 11p would be a form of clonal evolution secondary to monosomy 22 in certain meningiomas.

Adult↗

Synthesis of Saccharomyces cerevisiae invertase by Schizosaccharomyces pombe.

In order to gain information on the ability of the glycosylation system of Schizosaccharomyces pombe to process heterologous glycoproteins, the expression of Saccharomyces cerevisiae invertase in the former yeast was studied. Sc. pombe cells are able to produce enzymatically active invertase from the S. cerevisiae SUC2 gene introduced by transformation and the enzyme is glycosylated and secreted into the cell wall. However, Sc. pombe transformants do not glycosylate the heterologous enzyme as their own invertase since it is not bound by the lectin from Bandeiraea simplicifolia seeds, which indicates the absence of terminal galactose residues. Moreover, the electrophoretic mobility of the heterologous invertase is similar to that of the large enzyme from S. cerevisiae, both in its native form and after being deglycosylated with Endo H. These results suggest that the polypeptide chain of S. cerevisiae invertase is the primary factor for the glycosylation in Sc. pombe cells.

Concanavalin A↗

Expression of the SV40 promoter in fission yeast: identification and characterization of an AP-1-like factor.

The SV40 promoter is expressed well in the fission yeast S. pombe, and it initiates transcription at the same site as in mammalian cells. The majority of the enhancer sequences, however, do not contribute to this activity. DNAase I footprint analysis of the promoter revealed the presence of an AP-1-like factor in S. pombe cells that protects a region of the promoter almost identical to that protected by human AP-1. The specificity of binding of the yeast and mammalian AP-1 proteins was found to be similar. We have found two AP-1-like binding activities in budding yeast cells, one of which appears quite distinct from the binding activity of the product of the budding yeast GCN4 gene. We also demonstrate that in fission yeast the AP-1 binding site can act as an upstream activating sequence. The DNA-protein complexes containing the mammalian AP-1 and fission yeast AP-1-like factors are sensitive to phosphatase treatment, indicating that they may be phosphorylated.

Deoxyribonuclease I↗

Characterization of two casein kinase activities in the fungus Mucor rouxii.

Two cyclic-nucleotide independent soluble casein kinase activities (CK I and CK II) from the fungus Mucor rouxii have been isolated, characterized and found to fit in the general classification of type 1 (CK I) and 2 (CK II) casein kinases, according to their enzymatic and structural properties. Both enzymes phosphorylate acidic substrates, require Mg2+ and have a chromatographic behaviour on DEAE-Sepharose and phosphocellulose similar to their mammalian counterparts. CK I has a sedimentation coefficient of 3.5 S, uses ATP as a phosphate donor (Km = 40 microM), phosphorylates casein mainly on serine residues, its activity is strongly inhibited by KCl and polyamines. CK II has a sedimentation coefficient of 7.4 S, uses ATP and GTP as phosphate donors (Km ATP = 10 microM; Km GTP = 40 microM), phosphorylates casein in serine and threonine, its activity is stimulated by KCl and by polyamines and is inhibited by heparin (I50 = 0.5 micrograms/ml). Casein kinase activity associated to particulate fraction (40% of total) has been partially characterized and shown to be similar to the soluble CK I activity.

Amino Acids↗

Alpha-glucan synthesis on a protein primer. A reconstituted system for the formation of protein-bound alpha-glucan.

Reconstitution experiments with the DEAE-cellulose-treated enzymes, engaged in a two-step mechanism of synthesis of alpha-glucan bound to protein, are performed. Urea/sodium dodecyl sulfate/polyacrylamide gel electrophoretic analysis of the radioactive products synthesized by the reconstituted system shows highly glucosylated, labeled bands, whose apparent molecular masses change with the acrylamide concentration in the gels. The long carbohydrate chains synthesized during the second step arise from the sequential addition of glucosyl moieties to the glucoprotein formed during the first step. A deglucosylation experiment confirms that the product of the reconstituted system originates from the 38-kDa glucosylated component of the reaction 1 product by the addition of beta-amylase-sensitive glucosyl moieties. Our data suggest that specific phosphorylases and starch synthetases are found in potato tuber, which are capable of utilizing reaction 1 product as primer for the synthesis of protein-bound glucan.

Catalysis↗

Fournier's syndrome of urogenital and anorectal origin. A retrospective, comparative study.

Twenty-eight patients with genital and perianal necrotizing infections are described. The patients were divided into three groups according to the primary site of infection: group 1, anorectal (14 patients); group 2, urologic (ten patients), and group 3, idiopathic (four patients). The overall mortality was 25 percent, 28.5 percent for the anorectal group and 10 percent for the urologic group, although this difference is not statistically significant. Necrotizing infections of anorectal origin were more severe and had a less typical way of presentation, with subsequent delay in diagnosis and a higher rate of myonecrosis. As a consequence, more debridements and more fecal derivations had to be performed. The etiologic agents were the same among the three groups and comprised a number of anaerobes (Bacteroides spp, gram-positive cocci) as well as aerobes (microorganisms belonging to the Enterobacteriaceae and S. faecalis). Necrotizing fasciitis was the pathologic picture of nine of ten patients with Fournier's gangrene of urogenital origin and seven of 14 with an anorectal source. Synergistic necrotizing cellulitis was identified in half of those secondary to anorectal origin and only one of those with a urologic source.

Adult↗

Deletion 3p in two lung adenocarcinomas metastatic to the brain.

Cytogenetic analysis by direct and in vitro preparation of brain metastatic lesions from two lung adenocarcinomas have shown the presence of a recurrent chromosomal abnormality, del(3p). These results add new evidence about the presence of 3p- marker chromosomes in adenocarcinoma of the lung.

Adenocarcinoma↗

Chromosomal composition of a series of 22 human low-grade gliomas.

G-banded chromosomal analysis was performed on direct and/or in vitro cultures of 22 low-grade gliomas, including nine grade I-II astrocytomas, nine oligodendrogliomas, one mixed tumor oligodendroglioma-astrocytoma, and three ependymomas. Normal diploid stem lines were present in most astrocytomas and oligodendrogliomas, whereas, all three ependymomas displayed polyploid modal numbers. However, secondary cell lines showed the presence of clonal recurrent numerical abnormalities, mainly polysomy 7, monosomy 10 and 22, and loss of the Y chromosome. Clonal structural rearrangements were present with a low incidence; they mainly involved chromosomes #1 and #7. These patterns of chromosome involvement seem to correlate with the scarce previous cytogenetic banding data available from low-grade gliomas. They are also similar to the chromosome alterations found in high-grade gliomas.

Adolescent↗

alpha-Glucan synthesis on a protein primer, uridine diphosphoglucose: protein transglucosylase I. Separation from starch synthetase and phosphorylase and a study of its properties.

It was found that the DEAE-cellulose-treated UDP-Glc:protein transglucosylase I catalyzing the first step (reaction 1) in the formation of alpha-glucan bound to protein in potato tuber is not only specific for the glucosyl donor but also for the endogenous acceptor. A single radioactive 38-kDa macromolecular component appeared during denaturing polyacrylamide gel electrophoresis of reaction 1 product. The labeled component is probably the polypeptide subunit of the endogenous acceptor which is being glucosylated. The radioactivity incorporated in reaction 1 product was isolated from a protease digest as a low-molecular-mass glucopeptide fraction. A beta-elimination reaction carried out in the presence of a reducing agent demonstrated that only one glucosyl moiety is transferred from UDP-Glc to the aminoacyl residue, thus forming an O-glucosidic linkage. 3H-labeled sodium borohydride showed that serine and threonine are involved in the peptide bond to glucose. Ion-exchange chromatography on DEAE-cellulose, affinity chromatography on concanavalin-A--Sepharose, gel filtration on Sephacryl S-300 and sucrose density gradient centrifugation failed to separate the enzyme catalyzing reaction 1 from the endogenous acceptor.

Amino Acids↗