Isolation of 10 differentially expressed cDNAs in p53-induced apoptosis: activation of the vertebrate homologue of the drosophila seven in absentia gene.

We report the isolation of 10 differentially expressed cDNAs in the process of apoptosis induced by the p53 tamor suppressor. As a global analytical method, we performed a differential display of mRNA between mouse M1 myeloid leukemia cells and derived clone LTR6 cells, which contain a stably transfected temperature-sensitive mutant of p53. At 32 degrees C wild-type p53 function is activated in LTR6 cells, resulting in programmed cell death. Eight genes are activated (TSAP; tumor suppressor activated pathway), and two are inhibited (TSIP, tumor suppressor inhibited pathway) in their expression. None of the 10 sequences has hitherto been recognized as part of the p53 signaling pathway. Three TSAPs are homologous to known genes. TSAP1 corresponds to phospholipase C beta 4. TSAP2 has a conserved domain homologous to a multiple endocrine neoplasia I (ZFM1) candidate gene. TSAP3 is the mouse homologue of the Drosophila seven in absentia gene. These data provide novel molecules involved in the pathway of wild-type p53 activation. They establish a functional link between a homologue of a conserved developmental Drosophila gene and signal transduction in tumor suppression leading to programmed cell death.

Purification and characterization of 3 beta-hydroxysteroid-dehydrogenase/isomerase from bovine adrenal cortex.

The formation of 4-ene-3-ketosteroids from 3 beta-hydroxy-5-ene precursors is an obligatory step in the biosynthesis of hormonal steroids such as glucocorticoids, mineralocorticoids, estrogens and androgens. In the adrenal cortex, pregnenolone, 17 alpha-hydroxy-pregnenolone and dehydroisoandrosterone are converted to progesterone, 17 alpha-hydroxy-progesterone and androstenedione, respectively, by the enzymatic system 3 beta-hydroxy-5-ene steroid dehydrogenase and 3-keto-5-ene steroid isomerase (3 beta-HSD/I). The present work reports a two step purification procedure which yields an homogenous preparation of 3 beta-HSD/I from bovine adrenal cortex. It uses solubilization of the microsomal proteins followed by two chromatographic steps, i.e. DEAE-cellulose and heparine-sepharose columns. The enzyme was obtained as an homogeneous protein exhibiting an apparent molecular size of 45 kDa upon SDS-gel electrophoresis and of 81 kDa upon gel filtration. The purified enzyme exhibits both the 5-ene-3 beta-ol steroid dehydrogenase and isomerase activities in contrast to previous work using a more complex procedure which yielded a final preparation having lost its isomerase activity [Hiwatashi et al., Biochem. J. 98 (1985) 1519-1525]. N-terminal aminoacid (29 residues) sequence of the purified protein was determined and was found identical to that predicted from the nucleic acid sequence of the recently identified enzyme cDNA [Zhas et al. FEBS Lett. 259 (1989) 153-157].

Purification and properties of steroid 17 alpha-hydroxylase from calf testis.

Steroid 17 alpha-hydroxylase has emerged as a key enzyme in steroidogenic cells: (i) it represents the branch point between the 17-deoxy (mineralo) and the 17-hydroxy (gluco) corticosteroid pathways in the adrenal cortex; (ii) the corresponding specific cytochrome (P-450(17 alpha] is highly dependent upon hormonal regulation; and (iii) the enzyme also catalyzes the steroid 17-20 lyase reaction, leading to the major androgens in the testis. As a prerequisite to the study of its regulation in intact cell, 17 alpha-hydroxylase was purified from calf testis microsomal preparations. Following five chromatographic steps, the enzyme was obtained as an apparently homogeneous protein of Mr = 57 kDa upon gel electrophoresis. The procedure yielded a recovery of about 10% as judged by cytochrome P-450 assay. Whereas 17 alpha-hydroxylase specific activity was about 30-fold enriched during the purification, that of the C17-20 lyase was increased by about 6-fold, strongly suggesting that its organelle environment may modulate the enzymatic activity. The purified enzyme yielded a 20 N-terminal amino-acid sequence showing a complete homology with that of its adrenal counterpart and a polyclonal antibody raised against our preparation revealed a 57 kDa protein band in bovine adrenocortical microsomal extracts, upon immunoblotting experiments. It was thus concluded that bovine 17 alpha-hydroxylase activity is supported by highly similar if not identical enzymatic proteins in both testis and adrenal cortex tissues. The purified P-450(17 alpha) preparation is now being used in reconstitution experiments which suggest that microsomal components may contribute to a different expression of the enzyme specificity in its native testis or adrenocortical intracellular environment, respectively.

A 31P-NMR study of bovine adrenocortical mitochondrial metabolic activities.

High-field 31P-NMR spectroscopy has been used to study the metabolic activities of coupled bovine adrenocortical mitochondria in vitro. These differentiated organelles use oxygen as a substrate to support both oxidative phosphorylation and specific steroid hydroxylation reactions. The NMR technique allowed the resolution of two inorganic phosphate signals, attributed to the matrix and external medium phosphate pools, at low and high field, respectively. These signals were used to calculate the respective Pi concentrations and to obtain the pH of the two corresponding compartments. In addition, the NMR spectra displayed resonance signals corresponding to ADP added to the medium and to ATP synthesized during oxidative phosphorylation. NMR analysis of the mitochondrial perchloric acid extracts identified the major phosphate-containing metabolites, namely NADP+, NAD+, phosphocholine, phosphoethanolamine, sn-glycero-(3)phosphocholine, AMP, ADP, ATP and Pi. Upon addition of ADP and malate to the oxygenated suspension, the kinetics of mitochondrial external Pi consumption and of ATP synthesis, along with the intra- and extraorganelle pH variations could be monitored over time periods of approximately 30 min, in the absence and presence of different steroid hydroxylation substrates. A major observation was that oxidative phosphorylation, which takes place in the absence of steroid, was markedly inhibited as soon as steroid hydroxylation was operating. These observations show the potential of 31P-NMR spectroscopy in the study of metabolic activities of isolated intact mitochondrial organelles. Such an approach appears promising for further determination of the underlying mechanisms in the balance between vital oxidative phosphorylation and differentiated steroid hydroxylation which are under hormonal control in adrenocortical mitochondria as well as in other steroidogenic cell systems.

Molecular organization (topography) of cytochrome P-450(11)beta in mitochondrial membrane and phospholipid vesicles as studied by trypsinolysis.

Cytochrome P-450(11)beta from adrenal cortex is an intrinsic membrane protein embedded in the inner mitochondrial membrane. Topography of the protein inside a phospholipid bilayer was examined using controlled proteolysis of purified cytochrome P-450(11)beta following its integration into artificial liposomes. Inclusion of the protein into phospholipid vesicles led to a marked stabilization of the cytochrome activity. Trypsin treatment of the liposome-integrated cytochrome resulted in the rapid disappearance of the native protein moiety (47 kDa), while a major 34 kDa peptide component was formed. This peptide core retained the heme moiety and part of the cytochrome steroid-11 beta hydroxylase activity. Very similar observations were obtained when inside-out vesicles prepared from isolated adrenocortical mitoplasts were examined with the same approach. It is thus suggested that adrenocortical cytochrome P-450(11)beta is embedded in the inner mitochondrial membrane as well as in artificial liposomes by a major hydrophobic domain associated with the heme moiety while a limited domain remains accessible on the matrix side of the membrane surface. The previous described phosphorylation of the cytochrome P-450(11)beta on a serine residue, by the cAMP-dependent protein kinase is suggested to occur in the protein domain oriented toward the membrane surface, the phosphorylation site being lost under mild proteolytic digestion of the membrane-integrated protein.

[Localized spontaneous cytosteatonecrosis of the breast]. / Cyto-stéatonécrose mammaire localisée spontanée.

A clinical case of fat necrosis of the breast is reported. The main clinical, radiographical and ultrasonographical aspects are described and discussed. The importance of surgical biopsy is emphasized in the atypical cases.

Phosphorylation of purified mitochondrial cytochromes P-450 (cholesterol desmolase and 11 beta-hydroxylase) from bovine adrenal cortex.

Two key steroidogenic mitochondrial cytochromes P-450 (cholesterol side-chain cleavage (scc) and 11 beta-hydroxylation (11 beta)) were purified from bovine adrenal cortex and examined as potential phosphorylatable substrates using purified cAMP-dependent protein kinase subunit (C) and A type (CKA) and G type (CKG) cAMP-independent casein kinases. Of the two cytochromes P-450, only P-450 11 beta was able to incorporate phosphate from ATP in the presence of C (Km = 7.5 microM), whereas CKA and CKG were ineffective. Phosphorylation of P-450 11 beta (maximum incorporation of 1 mole of 32P per mole of cytochrome, only on serine residues) did not modify the enzymatic activity of an 11 beta-hydroxylation system reconstituted in vitro from purified components, when adrenodoxin was in excess in the reaction. However, kinetic studies showed that P-450 11 beta phosphorylation strikingly increases the P-450 11 beta-adrenodoxin affinity in a phosphorylation-dependent manner. This would result in a net increase in 11 beta-hydroxylase activity under in vivo conditions where adrenodoxin availability is limited. Possible significance of these observations in the regulation of differentiated adrenocortical functions remains to be further examined.

Cholinergic muscarinic stimulation of steroidogenesis in bovine adrenal cortex fasciculata cell suspensions.

Acetylcholine was found to acutely stimulate cortisol production by bovine fasciculata adrenocortical cell suspensions. This effect was maximal at 10(-4) M acetylcholine concentration, resulted in a 5-fold increase in cortisol production over the control after 1 h incubation, and represented about one fifth of the ACTH maximal stimulation under the same conditions. Acetylcholine-stimulated steroidogenesis was concentration-dependent (10(-8)-10(-5) M), proportional to the cell number (5 X 10(5)-1 X 10(6)) and reached a plateau after 30 min incubation. Use of various cholinergic specific agonists and antagonists showed that the steroidogenic action of acetylcholine was a typical muscarinic effect. This character is in agreement with the previously demonstrated presence of muscarinic receptors in bovine adrenocortical tissue. The steroidogenic effect of acetylcholine required the presence of extracellular calcium in the medium and was impaired upon addition of tetracaine and procaine. No change in cyclic AMP nor cyclic GMP levels could be detected in the system under acetylcholine stimulation. Acetylcholine appeared to exhibit a synergistic effect in combination with ACTH, and exogenous cyclic AMP; these observations suggest a different mechanism of action for acetylcholine and ACTH and point to a possible cholinergic participation in the regulation of adrenocortical differentiated functions in vivo.

[Associated myasthenia and disseminated lupus erythematosus. A report on two cases and complete review of the published literature (author's transl)]. / Les associations myasthénie-lupus érythémateux disséminé. A propos de deux observations avec revue complète de la littérature.

Two patients aged 47 and 48 years respectively were found to have associated immunity disorders: myasthenia and DLE in the first case, and erythroblastic anemia, myasthenia, a lupus syndrome, and a thymoma in the second case. The association of myasthenia and DLE has been reported 39 times in the published literature (20 times only if stricter biological criteria are applied). The association does not increase the severity of the patient's condition and a thymoma is not present more frequently. Studies on the major histocompatibility complex and lymphocyte levels are still insufficient in this context: the haplotype was HLA A1 B8 in three cases out of seven. The physiopathological data available cannot confirm the possibility of a common pathogenesis in which the thymus and lymphocytes could play a determining role.

[Congenital segmental duplication of the lumbar ureter (author's transl)]. / Dédoublement segmentaire congénital de l'uretère lombaire

In a 23-year-old man attacks of nephritic colic led to the discovery of an obstruction on the left lumbar ureter. Segmental resection of the ureter was performed, removing 10 mm of malformed, obstructed ureter. This was an incomplete duplication, the two ureteral segments lying side-by-side, each with its own musculature, for a distance of 7mm. Above and below the anomaly, the ureter was normal. This exceptional malformation is compared with other internal obstructions of the ureter.

[Results of a series of 100 highly selective vagotomies for duodenal ulcer (follow up of 6 months to 5 years) (author's transl)]. / Résultat d'une série de 100 vagotomies ultra-sélectives pour ulcère duodénal (recul de 6 mois à 5 ans).

The authors analyse a series of 100 highly selective vagotomies for duodenal ulcer; 92 operated patients were followed up for 6 months to 5 years. The mortality was nil, the digestive sequelae were rare or mild. The recurrence rate was 4.4 p. cent and the proportion of good or very good results according to Visick's classification was 87 p. cent. The authors emphasise the necessity for broad dissection of the cardia for complete vagotomy.

[Jejuno and ileo-ileal invaginations revealing mutiple melanic metastases of the small intestine. Case report]. / Invaginations jéjuno- et iléo-iléales révélatrices de multiples métastases mélaniques de l'intestin gréle. présentation d'une observation

The authors report the case of 60 year old man with multiple jeuno-ileal metastases from a malignant melanoma of the skin revealed by jejuno-jejunal intussusceptions. In the light of this case, the authors emphasize the frequency and preferential localisation of these metastases at the level of the jejunum and ileum, the usual mildness of their symptoms until the day where acute obstruction requires laparotomy. The multiple lesions, their diversity and their very rapid course.