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F Caballero

Publications and source records attributed to F Caballero.

9 recordsLinked to original sources
PubMed1992

Heme biosynthesis pathway regulation in a model of hepatocarcinogenesis pre-initiation.

1. Heme regulation before the appearance of hyperplastic nodules was investigated in mice models of hepatocarcinogenesis. 2. With this aim 5-aminolaevulinate synthetase (ALA-S), microsomal heme-oxygenase (MHO), mitochondrial and cytoplasmic rhodanese activities were examined throughout a period of 35 days in animals exposed to dietary p-dimethylaminoazobenzene (DAB). 3. ALA-S activity was significantly diminished (50%) on day 14, then showing a sharply rising profile from day 28 onwards, and reaching 350% on day 35. 4. A similar profile was observed for mitochondrial rhodanese activity. 5. Changes in MHO and cytoplasmic rhodanese activities were almost the opposite to those observed for ALA-S. 6. The distinctive alteration in mitochondrial and cytoplasmic rhodanese would suggest that it plays a subtle role in ALA-S regulation during carcinogenesis initiation through a mechanism that appears to involve subcellular localization controls perhaps by means of the breakage of cystine trisulphide postulated to act as an ALA-S activator. 7. Taking into account the present results, we suggest a probable mechanism for the onset of hepatocarcinogenesis that includes a primary activating liver status, provoking biochemical aberration leading to the stage of initiation of hepatocarcinogenesis involving the whole organ.

5-Aminolevulinate Synthetase↗
PubMed1978

T-cell depletion and in vitro thymosin inducibility in asthmatic children.

Thirty asthmatic children were compared with an equal number of age-matched healthy children. The mean peripheral blood T-lymphocyte level without foetal calf serum was lower in the asthmatic group (mean 970/mm3, as against 1740/mm3; P less than 0.0001), but this difference was abolished by adding foetal calf serum or thymosin, thus explaining how quite severe T-cell deficiency can be missed by widely used methods. The degree of eosinophilia and the degree of elevation of the plasma IgE level in the asthmatic patients were positively correlated. Positive correlations were also shown between the degree of severity of the asthma, the degree of eosinophilia and the degree of elevation of the plasma IgE level, but not the degree of depression of the T-cell numbers. If this T-cell deficiency reflects an inadequate suppression of IgE responses, a clinical trial of thymosin appears to be warranted.

Adolescent↗