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Biomedical subjects

R Ibañez

Publications and source records attributed to R Ibañez.

9 recordsLinked to original sources
PubMed2000

Characterization of metal finishing sludges: influence of the pH.

Metal finishing sludges are classified as metal hydroxide hazardous wastes due to the heavy metal release to the environment. This release, commonly determined by compliance lixiviation tests based on the equilibrium conditions at the end of the leaching experiment, is mainly dependent on the pH of the solution. In this work, the leaching behaviour of Cd, Cr, Cu, Fe, Ni, Pb and Zn, of the 32 metal finishing sludges coming from 16 European industrial facilities, and using the distilled water compliance test DIN 38414-S4, have been studied. The concentrations of chromium and copper in the leachates do not follow the solubility evolution of their hydroxide with the pH. The simple assumption of a heavy metal concentration in the leachate directly related to the solubility of the hydroxide is not in good agreement with the experimental results of the distilled water leaching test, probably due to the presence of different species, which can contribute to the metal mobility depending on the sludge composition. An experimental evaluation of the easily available amount of metals in real wastes seems to be necessary for disposal assessment. This paper contains valuable information, from orderly handling metal finishing wastes to the statistical studies of production and management of wastes suggested recently by the Commission of the European Community.

Environmental Pollutants↗
PubMed1993

Effect of neurotensin on growth hormone release in vivo.

In order to investigate the mechanisms involved in the in vivo Growth Hormone (GH) response to Neurotensin (NT) we assessed the influence of estrogen status as well as the effect of passive immunization with antisomatostatin and anti-Growth Hormone-Releasing Hormone (GHRH) on NT-induced GH secretion in pentobarbital anesthetized rats. We found that, contrary to GH responses to GHRH, estrogen-treated rats (one single injection of 200 micrograms s.c. of estradiol valerate, 3 days before the experiment), exhibited markedly increased GH responses to different doses of NT (7.5, 15 and 30 micrograms/kg, i.v.). The stimulatory effect of NT (30 micrograms/kg) on estrogen-treated rats was similar in rats that received normal rabbit serum or passively immunized with antisomatostatin or anti-GHRH serum. In conclusion, estrogens play a facilitatory role on NT-induced GH release in the rat, which is exerted through a mechanism independent of hypothalamic GHRH or somatostatin release.

Animals↗
PubMed1993

Parkinsonian syndrome in childhood after sodium valproate administration.

Among the side effects attributed to sodium valproate administration, the production of a parkinsonian syndrome is very uncommon, particularly in children. We report a 12-year-old girl with secondary epilepsy; 7 days after the initiation of valproate therapy she developed parkinsonism that disappeared completely when valproate was replaced by carbamazepine. We discuss the possible role of alterations in GABAergic neurotransmission in the extrapyramidal syndrome that developed.

Child↗
PubMed1993

[Complete testicular feminization syndrome. Report of a case].

A case of complete testicular feminization (Morris syndrome) in a male pseudohermaphrodite is described. The results of the hormone analyses and the histological features of the resected gonad are presented. The literature is reviewed with special reference to whether gonadectomy should be performed in the pre or post-pubertal period. We advocate early castration because of the high incidence of germ cell neoplasia and the possibility of virilization in case of incomplete androgenic resistance. Our approach is based on the satisfactory feminization achieved by exogenous estrogen therapy.

Adolescent↗