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Biomedical subjects

S Bartolucci

Publications and source records attributed to S Bartolucci.

7 recordsLinked to original sources
PubMed1978

[Localization of mitochondrial cytochrome b using specific antibodies].

Specific antibody has been obtained against cytochrome b (pig heart mitochondria). It inhibits the electron transport of the respiratory chain in the intact mitochondria at the cytochrome b site of the inner mitochondrial membrane. It has no effect on the isolated submitochondrial particles which are inside-out inner membrane vescicles free of any outer membrane or outside-out inner membrane. These findings indicate a probably not transmembranous topologic localization of cytochrome b; this component of the respiratory chain seems located near the outer side of the inner mitochondrial membrane.

Animals↗
PubMed1978

[Mitochondrial localization of cytochrome c1 with specific antibodies].

A specific antibody against cytochrome c1 (pig heart mitochondria) has been obtained. It inhibits the electron transport of the respiratory chain in the intact mitochondria at the cytochrome c1 site of inner mitochondrial membrane ; but it has no effect on the isolated submitochondrial particles (inside-out inner mitochondrial membrane vesicles free of any outer membrane or outside-out inner membrane). Thus the topologic position of cytochrome c1 in the inner mitochondrial membrane is asymetrically lcoated on the outer side of the inner mitochondrial membrane. These results agree with our previous researches on ATP-ase and cytochromes b, c and a, indicating the location on the inner side for the first one, transmembranous for the last one, on the outer side for the others respiratory chain components. Thus the electron transport from cytochrome b to a takes place in the outer region of inner mitochondrial membrane and the transmembranous location of cytochrome-oxidase facilitates the transfer of the electrons to oxygen.

Animals↗
PubMed1978

[Recurrent hyperparathyroidism following subtotal parathyroidectomy].

Recurrent hyperparathyreoidism occurred in 3 of 9 patients in terminal renal failure from 9 months to 2 years after an initially successful subtotal parathyroidectomy. In all cases we find temporary remission of clinical signs of hyperparathyreoidism after surgery. Our clinical experience provided by followup in these patients showed an insufficient biochemical and clinical control. We find recurrence in 3 cases and repeat neck exploration was indicated for 2 patients.

Humans↗
PubMed1977

[Variation of phosphagens in sea urchin eggs before and after fertilization].

Improved methods of separation, identification and determination of phosphagens have been applied to the study of monosubstituted guanidines and phosphagenes in sea urchin eggs, before and after fertilization. We have been able not only to identify in these materials phosphoarginine, but also phosphocreatine and to detect an unknown phosphagen. After fertilization, free arginine and creatine decrease, within respect to unfertilized eggs, whereas phosphocreatine undergoes a large increase; phosphoarginine remains almost constant, and an unknown phosphagen appears. These observations allow to interprete the results of some authors, who, applyng less refined methods, found only an increase in phosphoarginine in the same materials.

Animals↗
PubMedDate not supplied

Monovalent cations requirement of the fructose 1,6-bisphosphate-activated pyruvate kinase from E. coli.

The fructose 1,6-bisphosphate-activated pyruvate kinase from Escherichia coli has been purified by a simplified procedure, which gives a homogeneous enzyme in approximately half the working time required by other methods and is suitable for large scale preparations. The activity of the enzyme is strictly dependent on the presence of monovalent cations. Enzyme activity is elicited by K+ and NH4+, but not by Na+. Homotropic cooperativity is displayed in the activation by K+ and NH4+ and heterotropic effects are reciprocally exerted by monovalent cations and other ligands, such as phosphoenolpyruvate and fructose 1,6-bisphosphate. The allosteric nature of such interactions is suggested by changes in heat stability of the enzyme induced by K+ and fructose 1,6-bisphosphate. NH4+, but not K+, at high concentrations, cause an inhibition of enzyme activity.

Cations, Monovalent↗