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Biomedical subjects

G Soberón

Publications and source records attributed to G Soberón.

At least 19 recordsLinked to original sources
PubMed2001

Degradation of lineal alkylbenzene sulphonate (LAS) in an acidogenic reactor bioaugmented with a Pseudomonas aeruginosa (M113) strain.

The degradation of of lineal alkylbenzene sulphonate (LAS) was studied in a two-stage anaerobic system where the acidogenic reactor was bioaugmented with a strain of Pseudomonas aeruginosa (M113). This is a strain, which under aerobic and denitrifying conditions uses LAS as carbon source. Results show that LAS was only degraded within the acidogenic stage while in the methanogenic reactor there was no degradation and eventually there was an inhibition due to a LAS accumulation in the sludge. During the experiment, the M113 strain remained in the acidogenic conglomerate (at around 10(4) CFU/mL) although there is no evidence of their involvement in LAS degradation.

Alkanesulfonic Acids↗
PubMed1993

Cloning, characterization, and expression in Streptomyces lividans 66 of an extracellular lipase-encoding gene from Streptomyces sp. M11.

A gene encoding an extracellular lipase from Streptomyces sp. M11 was cloned in the high-copy-number vector pIJ486, using S. lividans 66 as host. A 28-kDa protein was secreted by S. lividans carrying pB13, which harbors a 6-kb insert, and identified as the product of the cloned gene. Comparison of the N-terminal amino acid (aa) sequence of the purified extracellular lipase with the nucleotide (nt) sequence of the lip gene revealed the presence of a 48 aa long signal peptide. The nucleotide sequence also revealed the presence of a motif, Gly-His-Ser-Met-Gly, similar to the one found surrounding the active-site Ser in other lipases. The gene is most likely monocistronic. Subcloning experiments indicated that another gene might be required for high-level expression, since subcloning of the structural gene alone resulted in diminished extracellular lipase activity. The lipase gene promoter was identified by S1 mapping experiments, and found to be similar to other Streptomyces vegetative promoters.

Amino Acid Sequence↗
PubMed1986

The health care reform in Mexico: before and after the 1985 earthquakes.

The earthquakes that hit Mexico City in September 1985 caused considerable damage both to the population and to important medical facilities. The disaster took place while the country was undertaking a profound reform of its health care system. This reform had introduced a new principle for allocating and distributing the benefits of health care, namely, the principle of citizenship. Operationally, the reform includes an effort to decentralize the decision-making authority, to modernize the administration, to achieve greater coordination within the health sector and among sectors, and to extend coverage to the entire population through an ambitious primary care program. This paper examines the health context in which the reform was taking place when the September earthquakes hit. After presenting the damages caused by the quakes, the paper analyzes the characteristics of the immediate response by the health system. Since many facilities within the system were severely damaged, a series of options for reconstruction are posited. The main lesson to be learned from the Mexican case is that cuts in health care programs are not the inevitable response to economic or natural crises. On the contrary, it is precisely when the majority of the population is undergoing difficulties that a universal and equitable health system becomes most necessary.

Delivery of Health Care↗
PubMed1969

Studies on the advent of ureotelism. The effects of bivalent cations on the capacity of the hepatic arginase of the Mexican axolotl to hydrolyse endogenous arginine.

1. The effects of 19 bivalent cations on the activity, stability and capacity to hydrolyse endogenous arginine of axolotl liver arginase were studied. 2. It was found that Fe(2+), Co(2+), Ni(2+) and Zn(2+), as well as Mn(2+), stabilize the enzyme and render it able to hydrolyse endogenous arginine. 3. By using different concentrations of Co(2+) and Ni(2+) it was possible to dissociate the effect of each of the metal ions on the activity and stability of arginase from that on its capacity to hydrolyse endogenous arginine. 4. The effects of Mn(2+), Co(2+) and Ni(2+) on the activity and stability of arginase in the homogenate were also observed with purer preparations of the enzyme. 5. It is suggested that the capacity to hydrolyse endogenous arginine is a consequence of the integration of arginase with the arginine-formation sites.

Animals↗
PubMed1968

Studies on the advent of ureotelism. Factors that render the hepatic arginase of the Mexican axolotl able to hydrolyse endogenous arginine.

1. A study was undertaken of the conditions that might operate in the synthesis and hydrolysis of arginine by axolotl liver homogenate to test a previous postulate that liver arginase of the non-metamorphosed Mexican axolotl is not able to hydrolyse arginine formed from citrulline and aspartic acid, though it can split exogenous arginine, and also that an enhanced capacity to hydrolyse endogenous arginine plays a major role in the advent of ureotelism observed during the metamorphosis of the axolotl. 2. It was found that the arginase from axolotl liver is very unstable under the conditions followed, contrary to what is observed in rat liver. 3. Axolotl arginase is able to hydrolyse endogenous arginine if preserved. 4. Mn(2+) protects the enzyme and renders it able to split endogenous arginine. 5. It is suggested that the metal ion produces a change of conformation of the enzyme that, being stable, is capable of hydrolysing the amino acid, or that the new conformation is appropriate for interaction with the sites of arginine synthesis.

Animals↗