Synchrotron Radiation Applied to Real-Time Studies of the Kinetics of Growth of Aluminum Nitride Thin Multilayers.

This article reports the design, construction, and first use of an experimental device consisting of a specially designed vacuum chamber equipped with a reactive sputtering magnetron (RSM) to be used for controlled deposition of thin films on a Si(100) flat substrate. The setup was designed to allow for in situ and real-time recordings of X-ray diffraction patterns during the growth of the deposited films and was installed in the X-ray diffraction and spectroscopy beamline emerging from a superconducting wiggler source at the Brazilian Synchrotron Light Laboratory. The first use of the RSM setup was an in situ and real-time X-ray diffraction study of processes of growth of multilayered aluminum nitride thin films, whereas the operation parameters of the reactor were sequentially changed. This sequential process led to the development of multilayered films. Alternate variations in chamber pressure and magnetron power density allowed us to obtain thin films composed of several micrometer thick layers, with alternate amorphous and (10·0), (00·2), or (10·1) textured polycrystalline structures.

Secretion of transforming growth factor-beta by the immature rat prostate.

Immature rat ventral prostate was used to identify a potent cell growth inhibitory factor in normal prostate. Both conditioned media and peptide extracts derived from ventral prostates inhibit the cellular growth and DNA synthesis in metastatic androgen-independent human prostate carcinoma cell line (PC3). The prostatic inhibitory factor was partially purified using an hydrophobic HPLC column (C18). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis (SDS-PAGE) of partially purified material revealed a major 25-kDa band. Immunoblot analysis showed similarity of the inhibitory factor to the transforming growth factor-beta (TGF-beta). Furthermore, the proliferation inhibiting activity of the prostatic factor was completely abolished by anti-TGF-beta antibodies. These data indicate that normal prostate produces a TGF-beta-like protein under non-physiological conditions.

[Demonstration of thymidine phosphorylase activity in human healthy, adenomatous and cancerous prostate]. / Mise en évidence d'une activité thymidine phosphorylase dans la prostate humaine saine, adénomateuse et cancéreuse.

The presence of thymidine phosphorylase in human healthy, adenomatous and cancerous prostate was demonstrated. The enzyme was responsible for the cleavage and synthesis of thymidine and for the transfer of deoxyribose from one deoxyribonucleoside to a pyrimidic base. The enzyme from normal and adenomatous prostate was retained on DEAE-Sephadex gel. In PC-3 cells, two enzymes with thymidine phosphorylase activity were present, one was retained on the gel, the second was excluded from it. Thymidine phosphorylase activity was higher in adenomatous and cancerous tissues that in healthy ones. In all tissues, the reactions of thymidine synthesis and of deoxyribose transfer were more important than that of thymidine cleavage.

[Effect of proteins from bovine milk serum on the multiplication of human cancerous cells]. / Effet des protéines du lactosérum bovin sur la multiplication de cellules cancéreuses humaines.

The addition of bovine milk whey to the culture medium of human cancerous cells (MCF-7 and PC-3) results in a significant reduction of cells growth. Milk whey acts more efficiently on MCF-7 than on PC-3 growth. The inhibition could be due to a protein. Its identification is now on progress.

[Prognostic value of thymidine kinase in cancer of the breast]. / Valeur pronostique de la thymidine kinase dans le cancer du sein.

We have measured by a radioenzymatic assay the thymidine kinase in the cytosol of 182 primary infiltrating breast cancers. Maximal follow-up is 95 months. Thymidine kinase was found to be related to SBR grade, tumour size and absence of oestradiol receptors (RE). Univariate analysis has pointed out a significant linkage between overall or metastase free survival and thymidine kinase, using a cut-off level of 80 mU/mg protein which is the most discriminating value. Thymidine kinase appeared to be particularly useful in lymph-node-positive, RE-negative and grade 3 patients. Multivariate analysis of the overall survival and of the metastase free survival (Cox model) revealed that they were strongly related to thymidine kinase status.

Positive and negative effects of estradiol-17 beta in the rat uterus.

Estrogens could act as effectors or inhibitors of protein synthesis in the rat uterus, depending on the doses given to animals. A single injection of estradiol-17 beta to immature female rats led to the increase in protein synthesis and in enzyme activities involved in DNA synthesis. Four injections, given once daily, resulted in the inhibition of enzyme activity and synthesis of all proteins but one. The 105 kD protein which showed a gradual increase with the duration of estrogen treatment could be responsible for the negative action of estrogens on uterine growth.

[Demonstration of pyrimidine nucleoside phosphorylases in breast cancer]. / Mise en évidence de pyrimidine nucléoside phosphorylases dans les cancers du sein.

Two pyrimidine phosphorylase activities have been isolated from the cytosol of cultivated MCF-7 cells of a human breast cancer, by ion exchange chromatography. Both enzymes are responsible for the cleavage of thymidine into thymine and deoxyribose-1-phosphate, for the synthesis of thymidine and for the transfer of deoxyribose from d-uridine to thymine. These activities are likely to participate in the regulation of the pool of pyrimidine nucleosides required for DNA synthesis.

[An uncommon form of thymidine kinase in breast cancers]. / Mise en évidence d'une forme inédite de la thymidine kinase dans les cancers du sein.

An unusual form of thymidine kinase has been found in cytosols from breast cancers. It differs from the adult and fetal isoenzymes of thymidine kinase in so far as its activity could not be isolated from that of thymidylate kinase. Following sucrose density gradients, electrofocusing, ion exchange chromatography or molecular sieving, both activities appeared as a single peak. These facts suggest that they could be attributed to a single multifunctional protein.

[Determination of thymidine phosphorylase in adenoma and cancer of the human prostate]. / Mise en évidence de la thymidine phosphorylase dans les adénomes et les cancers de la prostate humaine.

The presence of thymidine phosphorylase was observed in healthy, adenomatous and tumoral prostatic cells. In healthy and adenomatous tissues the enzyme activity was recovered as a single peak after ion exchange chromatography on DEAE-Sephadex gel. On the contrary, two forms of thymidine phosphorylase were found in prostatic cancers, one of them, with high activity appeared consequently as a characteristic feature of prostatic tumoral cells.

Estrogen-like effect of 5-androstene-3 beta,17 beta-diol on the induction of fetal thymidine kinase in the rat uterus.

The action of 5-androstene-3 beta,17 beta-diol (Adiol) on Thymidine Kinase (TK) was studied in the rat uterus. It appeared that Adiol, like 17 beta-estradiol (E2), could induce the synthesis of the fetal isoenzyme of TK. Its effects compared with those of E2, were delayed by 6 h and higher doses were required to reach the same levels of induction. The action of Adiol on TK was exclusively observed in tissues where E2 receptors were present. Moreover, Adiol could stimulate the activity of uterine DNA-polymerase alpha. These observations are additional evidence of the estrogen-like behaviour of Adiol. They suggest that it could participate in proliferative processes of tissues which are dependent on estrogens.

Some characteristics of fetal and adult isoenzymes of thymidine kinase in human breast cancers.

Two isoenzymes of Thymidine Kinase were isolated from 90 human breast cancers by ion exchange chromatography. One was the enzyme present in adult tissues (TK-A), the second corresponded with the enzyme found in fetal tissues (TK-F). The presence of both isoenzymes was observed in the 90 tumors investigated. The activity of TK-A varied in the same range as in normal tissues, while the activity of TK-F varied to a larger extent and was higher than that of TK-A in a majority of tumors. Moreover, TK-F activity was independent of the presence or of the level of estradiol and progesterone receptors. Both isoenzymes were further characterized and compared.

[Prognostic value of fetal thymidine kinase measurements in breast cancer]. / Intérêt pronostique du dosage de l'activité de la thymidine kinase foetale dans les cancers du sein.

Estimation of fetal Thymidine Kinase activity in primary tumors could be a useful parameter in the assessment of early relapses in patients with breast cancer. In a group of 39 women followed up for 42 months, the percentage of early relapses and their frequency was significantly higher in patients whose tumors had a high level of enzyme activity than in others.

[Stimulation and selective inhibition of protein synthesis by 17 beta-estradiol, in the uterus of immature rats]. / Stimulation et inhibition sélective de la synthèse protéique par le 17 beta-oestradiol, dans l'utérus de la ratte immature.

The in vitro translation of RNAs extracted from immature female rat uteri 24 hrs. after one or four daily injections of 17 beta-oestradiol was carried out. The proteins labelled with (35S) methionine were separated by polyacrylamide gel electrophoresis and the resulting autoradiograms were scanned. The densitometric profile of uterine proteins obtained after a single injection of oestrogen showed a considerable increase in the majority of them, compared with controls. Following four injections of 17 beta-oestradiol the synthesis of all but one of the uterine proteins was observed. The Mr of the protein induced by repeated administration of oestrogens was about 105 kdaltons. This protein could possibly be involved in the inhibition of protein synthesis observed in the rat uterus after reiterated injections of 17 beta-oestradiol to female rats.

Inhibition by Celiptium of the fetal thymidine kinase synthesis induced by estrogens in the rat uterus.

Celiptium (Ce) is an antitumor drug used in the therapy of breast carcinomas, which are to a large extent dependent on estrogens. We have studied the effect of Ce on some proteins induced by estradiol (E2) in the rat uterus. It was observed that Ce administered at the same time or before E2, was able to inhibit the induction by E2 of fetal thymidine kinase (TK-F), of creatine kinase of brain-type (CK-BB) and of progesterone receptor (PR). When Ce was given after E2, its inhibitory effects were less evident. Results seemed to indicate that Ce could bind the acceptor sites for E2 receptor and thus inhibit the activity of E2-regulated genes. This assumption was corroborated by the fact that Ce did not modify the activity of enzymes not submitted to E2 regulation.

[Close relation between fetal thymidine kinase and thymidylate kinase activities in breast cancer]. / Relation étroite entre les activités de la thymidine kinase foetale et de la thymidylate kinase dans les cancers du sein.

In human breast cancers, assays on thymidine kinase activity revealed the synthesis of large amounts of d-TTP. This fact suggested the presence of thymidylate kinase closely associated with thymidine kinase. Results obtained with experimental tumors were quite different. These tumors appeared inadequate for the study on thymidine metabolism in mammary cancers.

[Induction of fetal thymidine kinase by phyto-estrogens in the immature rat uterus]. / Induction de l'activité de la thymidine kinase de type foetal par des phyto-oestrogènes dans l'utérus de la ratte immature.

Administration of phytooestrogens to immature female rats leads to a large increase in uterine thymidine kinase activity. That increase concerns to a large extent the fetal isoenzyme of thymidine kinase. These results confirm the estrogenic properties of phytoestrogens and allow to specify their physiological effects.

[Demonstration of fetal-type thymidine kinase in cancer of the breast]. / Mise en évidence de la thymidine kinase de type foetal dans les cancers du sein.

Seventy five human breast cancers were examined in order to search for the presence of thymidine kinase of the fetal-type (TK-F). The presence of TK-F was evidenced in all tumors. Its activity varied from one to another tumor, but it was evident that the increased TK activity observed in mammary cancers could exclusively be related to high TK-F activity. Some relations between TK-F activity and the presence of estradiol and progesterone receptors (ER, PR) were obvious. The highest activities were observed in cancers with high level of ER and PR. Thymidylate kinase activity (d-TTP synthesis) varied in parallel with TK-F activity. In a general way, it was higher in ER+ PR+ than in ER+ PR- cancers.

Induction of the synthesis of thymidine kinase by aldosterone in the kidney of the immature male rat.

Thymidine kinase activity was studied in kidneys from immature male rats after administration of aldosterone. Kinetic studies showed that the enzyme activity reached its maximum level 24 h after aldosterone injection. That increase was specific for aldosterone and could be related to the synthesis of new molecules of enzyme.

Stimulation by estradiol-17 beta of thymidine kinase activity in the rat uterus.

The action of estradiol-17 beta (E2) on thymidine kinase (TK) activity was studied in uteri from immature female rats. It was demonstrated that a single injection of E2 highly stimulated the enzyme activity which reached its maximum level 24 h after hormone administration. Physiological amounts of E2 were efficient and changes in TK activity were observed exclusively in uterus and liver. A single injection of Tamoxifen produced the same effect as E2 but repeated administration resulted in the complete inhibition of enzyme activity. Using antibiotics it was demonstrated that E2 induced the synthesis of new enzyme molecules rather than an increase in enzyme activity. This statement was corroborated by the fact that after hormone administration the increase in TK activity was preceded by an increase in RNA-polymerase activity and followed by that in DNA-polymerase alpha activity. Moreover, the separation of TK isoenzymes on DEAE-Sephadex and the use of d-CTP as inhibitor of the adult isozyme suggested that E2 induced the "fetal" form of the enzyme. In addition, it was demonstrated that TK activity in uteri from ovariectomized adult female rats was enhanced by E2 administration, and that the increase was due to the stimulation of the fetal isoenzyme. It was suggested that TK could be used as a marker of the action of estrogens and antiestrogens in target organs.