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Biomedical subjects

E Caballero

Publications and source records attributed to E Caballero.

At least 19 recordsLinked to original sources
PubMed1995

[Type 2 human immunodeficiency virus infection (HIV-2) in Spain: analysis of the first 50 cases. Spanish Group for the Study of HIV-2].

BACKGROUND: Infection by the human immunodeficiency virus type 2 (HIV-2) is endemic in West Africa where it is responsible for many AIDS cases. HIV-2 has been described in subjects in other countries, mainly in African immigrants, although it may also be found in natives. The first cases of HIV-2 infection were identified in Spain in 1988. METHODS: The clinical, epidemiologic and virologic characteristics of the subjects with HIV-2 infection identified in Spain up to November 1994 are described. RESULTS: Fifty people have been diagnosed with HIV-2 infection, being found mainly around the large urban centers (20 cases in Madrid and 16 in Barcelona). All the cases were African immigrants except for 10 Spaniards (20%), 6 of whom had acquired the infection in endemic areas while the other 4 (one prostitute from Barcelona and 3 bisexual males from Guipúzcoa) had acquired the infection in Spain. Heterosexual transmission was implicated in all the cases except in 6 subjects (4 bisexual males, one case of probable intravenous transmission and one vertically infected child). Eight (all Spanish) patients have developed AIDS and 5 have died to date. At least 10 other subjects have a CD4+ lymphocyte count lower than 0.2 x 10(9)/l, one being the only pediatric patient (6-year-old male). CONCLUSIONS: HIV-2 infection is present in Spain, although there is no evidence for a rapid dissemination of the virus outside the collective of African immigrants. The Spaniards with HIV-2 infection represent 20% of the cases having contracted the virus through sexual relations with natives from endemic areas.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Spanish talcs for pharmaceutical use. Mineralogic, chemical composition, physico-chemical properties].

A study has been carried out on the possible pharmaceutical use of 4 spanish talcs by direct estimation of the mineral purity by means of X-ray diffraction techniques, chemical analysis and quantification of some physico-chemical properties. There is a high level of talc in the samples 2 and 4, except in the talc 1 and the talc 3, with a relatively high content of chlorides. Quartz, calcite, feldspar, smectite, inter-stratified phases, kaolinite, amphibole, muscovite and dolomite are other contaminating minerals. The negative effects of these minerals on the pharmaceutical use of the talc include changes in the physical properties (colour), in the chemical ones (contained in heavy metals) as well as in the physico-chemical ones (adsorption properties). The data concerning cation exchange capacity and total specific surface are slightly higher than those concerning the pure mineral, and this is due to the occurrence of some contaminating minerals.

Chemistry, Pharmaceutical↗
PubMed1983

Identification of lactaldehyde dehydrogenase and glycolaldehyde dehydrogenase as functions of the same protein in Escherichia coli.

Lactaldehyde dehydrogenase is an enzyme involved in the aerobic metabolism of fucose in wild type Escherichia coli, and glycolaldehyde dehydrogenase is an enzyme involved in the metabolism of ethylene glycol in mutant cells able to utilize this glycol. Both enzyme sources display oxidative activity on either substrate with a constant ratio between these activities. We have found that both enzymatic activities present the same electrophoretic mobility when crude extracts were electrophoresed in polyacrylamide gels and the gels stained for enzyme activities. Furthermore, both enzymatic activities co-chromatograph in a DEAE-Sephadex column. If lactaldehyde dehydrogenase of wild type cells is purified near homogeneity and the purification procedure is screened for both aldehydes as substrates, only one enzyme is apparent, giving again a constant ratio between lactaldehyde and glycolaldehyde dehydrogenase activities. Genetic evidence of the fact that both activities are functions of the same protein is provided by the observation that mutation to thermosensitivity for the production of lactaldehyde dehydrogenase affected in the same way the production of glycolaldehyde dehydrogenase. Glycolaldehyde dehydrogenase from mutant cells is purified in a procedure coincident with the lactaldehyde dehydrogenase purification, yielding a single enzyme electrophoretically indistinguishable from the purified lactaldehyde dehydrogenase. Peptide mapping of the purified preparation after digestion with chymotrypsin or Staphylococcus aureus protease V8 gives an indistinguishable band pattern between both enzymes.

Aldehyde Oxidoreductases↗
PubMed1983

Experimental evolution of a metabolic pathway for ethylene glycol utilization by Escherichia coli.

Spontaneous mutants of Escherichia coli able to grow on ethylene glycol as a sole source of carbon and energy were obtained from mutants that could grow on propylene glycol. Attempts to obtain ethylene glycol-utilizing mutants from wild-type E. coli were unsuccessful. The two major characteristics of the ethylene glycol-utilizing mutants were (i) increased activities of propanediol oxidoreductase, an enzyme present in the parental strain (a propylene glycol-positive strain), which also converted ethylene glycol into glycolaldehyde; and (ii) constitutive synthesis of high activities of glycolaldehyde dehydrogenase, which converted glycolaldehyde to glycolate. Glycolate was metabolized via the glycolate pathway, which was present in the wild-type cells; this was indicated by the induction in ethylene glycol-grown cells of glycolate oxidase, the first enzyme in the pathway. Glycolaldehyde dehydrogenase was partially characterized as an enzyme of this new metabolic pathway in E. coli, and glycolate was identified as the product of the reaction. This enzyme used NAD and NADP as coenzymes, although the NADP-dependent activity was about 10 times lower than the NAD-dependent activity. Uptake of [14C]ethylene glycol was dependent on the presence of the enzymes capable of metabolism of ethylene glycol. Glycolaldehyde and glycolate were identified as intermediate metabolites in the pathway.

Acetaldehyde↗