PubMed Health⌕ Search

Biomedical subjects

E García

Publications and source records attributed to E García.

At least 235 records · Page 13Linked to original sources
PubMed1985

[Nephropathy of the Schöenlein-Henoch syndrome: long-term prognosis in non-selected patients].

Nephritis plays a major role in long-term prognosis of Schönlein-Henoch syndrome. We have studied a group of 142 children with this syndrome; 43 (30.2%) showed clinical evidence of renal disease. Renal biopsy was obtained in 12 cases. A subgroup of 36 patients have been controlled during a much greater two years period. Thirty-five are asymptomatic and one with minor urinary anomalies. Thereafter in our experience the long-term prognosis (means = five years) of Schönlein-Henoch syndrome is excellent in unselected patients.

Adolescent↗
PubMed1984

Restriction cleavage maps of the DNAs of Streptococcus pneumoniae bacteriophages containing protein covalently bound to their 5' ends.

Several pneumococcal bacteriophages showing a morphology similar to that previously described for Cp-1 (Ronda et al. 1981) have been isolated and purified from throat samples taken from healthy children. Three of these phages (Cp-5, Cp-7 and Cp-9) have been studied in detail and compared to Cp-1. The four phages differed in several respects, e.g. size, structural polypeptides, restriction enzyme cleavage patterns, etc. The DNA of Cp-5, Cp-7 and Cp-9 showed protease-sensitive transfecting activity. This, together with the results obtained by electrophoretic analyses as well as by isotopic labelling of these DNAs with [gamma-32P]ATP and polynucleotide kinase indicated that all these new phages have a protein covalently linked to the 5' ends of their DNAs as in the case of Cp-1 (García et al. 1983). Restriction enzyme cleavage maps of Cp-1, Cp-5, Cp-7 and Cp-9 have been constructed.

Bacteriophages↗
PubMed1984

Nucleotide sequence at the termini of the DNA of Streptococcus pneumoniae phage Cp-1.

The 5' ends of Cp-1 DNA, which have a covalently linked terminal protein, can be partially unblocked by treatment with 1 M NaOH (E. Garcia, A. Gomez, C. Ronda, C. Escarmis, and R. Lopez (1983) Virology 128, 92-104) and labeled with polynucleotide kinase and [gamma-32P]ATP. The sequence of the first 444 and 520 nucleotides at the termini of Cp-1 DNA has been determined. A 236-nucleotide-long inverted terminal repeat was found and, in addition, the 116 nucleotides following the repeat show 93% homology. The first 352 nucleotides at both ends have an adenine plus thymine content of 75%. More than 50% of the nucleotides of the sequenced regions are involved in repeats of a minimum of 8 nucleotides. Three promoter-like sequences were also found at each end of Cp-1 DNA.

Bacteriophages↗
PubMed1984

Conditions to enhance transfection in Streptococcus pneumoniae.

Enhancement of transfection in the wild-type strain of Streptococcus pneumoniae, which contains normal levels of nucleases, can be achieved by a careful control of the components of the medium. Protection of the donor DNA against the degradation by the nucleases present at the surface of the cell during the adsorption to the physiologically competent bacteria is a necessary condition to obtain an enhanced transfection. Using [3H]thymidine-labeled Dp-4 DNA we have found that maximal levels of DNA uptake and a remarkable stimulation in genetic transfection were obtained in the presence of calcium ions. Concentrations of magnesium ions higher than 2 mM stimulated the extracellular degradation of the donor DNA and inhibited transfection.

Bacteriophages↗
PubMed1984

Cytotoxic antibodies in sera of Venezuelan multiparous women of Amerindian and mixed ethnic origin.

Sera from 464 multiparous women of mixed ethnic origin and 114 Amerindian mothers (Warao of Western Venezuela), were studied for lymphocytotoxicity using a panel of B and T lymphocytes isolated from 50 to 100 individuals from the same populations. Twenty-five and 9.65% of the sera, respectively, showed activity against at least 5% of the panel. Among the women of mixed ethnic origin 10% produced antibodies directed against one or more HLA Class I antigens while 2 sera contained monospecific anti-DR antibodies; among the Warao, only 2 sera recognized HLA antigens: a Bw51 and an undetermined Cw antigen which shows linkage disequilibrium with Bw16 in both populations.

Adult↗
PubMed1984

Biochemical characterization of a murein hydrolase induced by bacteriophage Dp-1 in Streptococcus pneumoniae: comparative study between bacteriophage-associated lysin and the host amidase.

A phage-associated lysin recently isolated and purified from Streptococcus pneumoniae infected with bacteriophage Dp-1 has been biochemically characterized as an endo-N-acetyl-muramyl-L-alanine amidase. The purified peptides obtained after treatment of the cell wall with phage-associated lysin are composed of glutamic acid, alanine, lysine, glycine, serine, and aspartic acid in the molar ratios of 1.0:1.6:1.0:1.0:0.8:0.6. The N-terminal amino acid of this peptide has been characterized as alanine. This amidase and the inactive form of the amidase (E form) previously purified (J.V. Höltje and A. Tomasz, J. Biol. Chem. 251:4199-4207, 1976) from S. pneumoniae differ in their molecular weights, as well as in their capacity to be stimulated by reducing agents, and do not cross-react immunologically, although anti-phage-associated lysin serum was able to recognize and inhibit both phage-associated lysin and the active form (C form) of the host amidase.

Amidohydrolases↗
PubMed1983

Pneumococcal bacteriophage Cp-1 contains a protein bound to the 5' termini of its DNA.

The genome of the pneumococcal bacteriophage Cp-1 has been isolated as a DNA-protein complex. The transfecting activity of this complex is destroyed by treatment with proteolytic enzymes. The DNA-protein complexes do not enter into agarose or acrylamide gels and are retained on glass fiber filters. The protein is specifically associated with the two 5' termini of Cp-1 DNA on the basis of experiments carried out with restriction endonucleases, exonucleases, and radioactive labeling with [gamma-32P]ATP and polynucleotide kinase. The protein component, iodinated in vitro with 125I, has a molecular weight of 28,000 determined by SDS-polyacrylamide gel electrophoresis. The protein remains associated with the Cp-1 DNA after thermal or alkali denaturation, incubation with 6 M guanidinium chloride or 8 M urea, and boiling in 2% SDS, 2% mercaptoethanol, and 6 M urea. When the complex was incubated in 1 M sodium hydroxide or 2.5 M piperidine only a partial breakage of the DNA-protein bond was observed. These results indicate that the 28,000-Da protein is covalently bound to the 5' termini of the DNA.

Bacteriophages↗
PubMed1983

Protease-sensitive transfection of Streptococcus pneumoniae with bacteriophage Cp-1 DNA.

The transfecting activity of pneumococcal phage Cp-1 DNA was destroyed by treatment with proteolytic enzymes, although these enzymes did not affect transfection with bacteriophage Dp-4 DNA. This transfection was stimulated by calcium ions. Protease-treated Cp-1 DNA competes for binding and uptake with transforming pneumococcal DNA as well as with transfecting Dp-4 DNA to approximately the same extent as does untreated Cp-1 DNA. In addition, [3H]thymidine-labeled Cp-1 DNA, treated with proteases or untreated, was absorbed with the same efficiency. These data suggest that uptake of Cp-1 DNA is not affected by protease treatment. [3H]thymidine-labeled Cp-1 DNA showed remarkable resistance against surface nuclease activity of competent wild-type cells. The monomeric form of the Cp-1 DNA-protein complex showed a linear dose response in transfection.

Bacteriophages↗
PubMed1982

[Coagulation parameters in patients with hypertension].

Thrombelastography in the whole blood and determination of antithrombin III by means of chromogenic substrates were performed in a group of 10 patients with hypertension. The results of the thrombelastograms showed a slight shift toward hypercoagulability, as revealed by a significant increase in the thrombodynamic potential index. There was no significant change in antithrombin activity as compared with control group.

Adult↗
PubMed1981

Detection of different types of receptors for deoxyribonucleic acid in competent Bacillus subtilis.

Competent cells of Bacillus subtilis are able to bind but not to take up DNA in magnesium-free medium. Wall-membrane complexes, but not cell walls, bind homologous DNA. Binding of DNA to membrane vesicles suggests that DNA-receptor sites are located at the membrane level. On the basis of competition experiments with homologous and heterologous DNAs, in cells and in membrane vesicles, different types of DNA receptors are detected.

Bacillus subtilis↗
PubMed1981

Isolation and characterization of a new bacteriophage, Cp-1, infecting Streptococcus pneumoniae.

Several pneumococcal phages showing a morphology completely different from those of all other previously found pneumococcal bacteriophages have been isolated. Bacteriophage Cp-1, one of the phages isolated, showed an irregular hexagonal structure and a short tail of 20 nm. The virion density was 1.46 g/cm3. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of nine polypeptides. The polypeptide showing a molecular weight of 39,000 accounted for more than the 90% of the total protein. The nucleic acid of Cp-1 was linear, double-stranded DNA with a mean length of 6.3 microns and a guanine-plus-cytosine content of 41%; its buoyant density was 1.699 and 1.422 g/cm3 in CsCl and CS2SO4, respectively. Its sedimentation coefficient (S20,w) was 19S. Cp-1 DNA showed a remarkable resistance to a large number of restriction endonucleases. A total of 12 fragments, ranging in molecular weight from 1.3 X 10(6) to 0.09 X 10(6), were produced by AluI, two fragments (molecular weight, 5.5 X 10(6) and 0.9 X 10(6)) were generated by HindIII, and two fragments (molecular weight, 6.0 X 10(6) and 5.7 X 10(6)) were produced by HaeIII. The easy visualization of th plaques produced by Cp-1, the small size of Cp-1 DNA (12 X 10(6) daltons), and other biological and physiochemical properties make this phage potentially useful for genetic studies.

Adsorption↗
PubMed1979

Bacteriophages of Streptococcus pneumoniae. Physicochemical properties of bacteriophage Dp-4 and its transfecting DNA.

The properties of Dp-4 phage and its DNA have been studied. The phage has a polyhedral head of 60 nm diameter, a tail 155 nm long and a buoyant density in CsCl of 1.48 g/cm3. Analysis by acrylamide gel electrophoresis indicates the presence of five polypeptides. Dp-4 DNA has a molecular weight of 37 x 10(6), a melting point of 83.5 degrees C (when dissolved in 0.15 M NaCl/0.015 M sodium citrate, pH 7.0) and a G + C content of about 33%. Denaturation of DNA yields two strands of different buoyant density in a neutral CsCl gradient. The interaction of poly(U, G) with the heavy strand strongly enhances its density and allows the preparative separation of both strands. Native Dp-4 DNA has unusual physical properties: abnormally low buoyant densities both in CsCl (1.666 g/cm3) and in Cs2SO4 (1.410 g/cm3) (which do not correspond to the value predictable from the G + C content of the DNA), and a high thermal stability at low ionic strength.

Bacteriophages↗