Alteration of poly (ADP-Rib) synthesis during progesterone- caused gene expression in oviducts of quails

Haemostatic management of intraoral bleeding in patients with congenital deficiency of alpha2-plasmin inhibitor or plasminogen activator inhibitor-1

Haemostatic management of intraoral bleeding was investigated in patients with congenital alpha2-plasmin inhibitor (alpha2-PI) deficiency or congenital plasminogen activator inhibitor- 1 (PAI-1) deficiency. When extracting teeth from patients with congenital alpha2-PI deficiency, we advocate that 7.5-10 mg kg(-1) of tranexamic acid be administered orally every 6 h, starting 3 h before surgery and continuing for about 7 days. For the treatment of continuous bleeding, such as post-extraction bleeding, 20 mg kg(-1) of tranexamic acid should be administered intravenously, and after achieving local haemostasis 7.5 mg kg(-1) of tranexamic acid should be administered orally every 6 h for several days. In addition, when treating haematoma caused by labial or gingival laceration or buccal or mandibular contusion, haemostasis should be achieved by administering 7.5-10 mg kg(-1) of tranexamic acid every 6 h. Tranexamic acid can also be used for haemostatic management of intraoral bleeding in patients with congenital PAI-1 deficiency, but is less effective when compared with use in patients with congenital alpha2-PI deficiency. Continuous infusion of 1.5 mg kg(-1) h(-1) of tranexamic acid is necessary for impacted tooth extraction requiring gingival incision or removal of local bone.

Age-dependent increase of DNA topoisomerase II activity in quail oviduct; modulation of the nuclear matrix-associated enzyme activity by protein phosphorylation and poly(ADP-ribosyl)ation

Nuclear DNA topoisomerase II activity in quail oviduct tissue was found to increase by about 70% with age. This age-dependent increase was observed with both the enzyme in whole nuclear extract and nuclear matrix-associated topoisomerase II. Both purified topoisomerase II and the nuclear matrix-bound enzyme were found to be modifiable by phosphorylation and poly(ADP-ribosyl)ation. Phosphorylation of the purified enzyme by isolated nuclear protein kinase NII or protein kinase C resulted in a 2- to 3-fold increase in specific activity, while poly(ADP-ribosyl)ation by soluble poly(ADP-ribose) synthetase caused a 50% inhibition of the enzyme. Using immunoprecipitation and immunoblotting procedures, phosphorylation and poly(ADP-ribosyl)ation could also be demonstrated to occur with the nuclear matrix-associated enzyme. The nuclear matrix-associated NII-like protein kinase activity, assumed to be involved in post-translational modification of topoisomerase II, displayed a 1.4- to 1.6-fold increase in old animals compared to mature ones, while the matrix-bound poly(ADP-ribose) synthetase activity decreased by about 50%. It is suggested that age-correlated enhancement of DNA topoisomerase II activity, possibly due to age-dependent changes in activities of nuclear protein kinases and poly(ADP-ribose) synthetase, may result in alterations in the topological state of DNA, possibly affecting DNA replication, transcription and repair with age.

Progesterone action in preparation for decidualization

An attempt has been made to describe several actions of progesterone related to the preparation of the uterus for decidualization. These actions result from classical ligand-receptor interactions as well as from nonreceptor-mediated changes, that is, those imposed by metabolic inactivation of the steroid. By opposing some of the effects of estrogen, the progestogen alters the utilization of NAD in the endometrium to induce an increase in NADP+ production, elevation of the NADP+/NADPH ratio, and inhibition of the rate of degradation of NAD to NAM and ADP-ribose. These changes are correlated with an inhibition or delay in endometrial DNA synthesis and mitosis, an increased potential for differentiation, and the development of uterine sensitivity to decidual induction. A decidual-inducing stimulus can reverse these progestogen-dependent effects rapidly by limiting the rate of synthesis of NADP+ from NAD. Though one possible mechanism for this reversal may include the inhibition of NAD-kinase by cAMP, there is evidence to suggest that such a direct cause-effect relationship is at present tenuous.

Differentiation of the uterus in preparation for gestation: a model for the action of progesterone

During the preimplantation stages of pregnancy, rising titers of progesterone alter the metabolism of the uterine endometrium to permit implantation of the blastocyst. In this model of progestational differentiation, it is proposed that endometrial pyridine nucleotide metabolism is a key target of progestogen action. The hormone may modulate NAD metabolism to promote NADP synthesis while inhibiting NAD breakdown to ADP ribose and nicotinamide. The result of such an action would impair uterine DNA synthesis and cell division, but provide increased NADP for coenzyme-limited synthetic processes and cytodifferentiation. As a result, the endometrium differentiates and becomes sensitive to decidual-inducing stimuli (the blastocyst). The decidual stimulus reverses the process by rapidly inhibiting NADP production, and by dramatically increasing poly ADP ribosylation of nuclear protein, thus facilitating DNA synthesis and the wave of cell division associated with the initiation of decidualization. The background information and evidence in support of this model are presented.

Chromatin structure from the marine sponge Geodia cydonium

The histones isolated from the siliceous sponge Geodia cydonium have been separated using two electrophoretic techniques. A comparison of their mobilities with those of calf thymus and rat liver show that some Geodia histone species (H3, H1 and H1(0) exhibit electrophoretic variance. The results show, that as in other eukaryotic systems the sponge chromatin contains the core histones (H2A, H2B, H3 and H4) and the linker histone (H1). ADP-ribosylation of Geodia histones and separation of the individual histones by electrophoresis resulted in four histones being radiolabeled. Digestion of Geodia chromatin with endogenous endonuclease is shown to result in the formation of nucleosome particles containing approximately 200 base pairs of DNA. A major product of endogenous endonuclease digestion is a relatively stable 110 base pair intermediate. Incubation of chromatin with DNase II and separation of the products under denaturing conditions reveals 20 bands migrating at 10 base intervals.

Protease inhibitors in rheumatoid synovial fluid. Analyses of electrophoretic homogeneity and protease inhibitory capacity

Paired plasma and synovial fluids from 17 patients with seropositive rheumatoid arthritis were examined for electrophoretic homogeneity/heterogeneity and enzymic inhibitory capacity of the protease inhibitors. The high degree of saturation (approximately 90%) of the polyvalent protease inhibitor alpha 2-macroglobulin in the rheumatoid synovial fluid contrasts sharply with the low saturation of alpha 1-anti-trypsin. The inhibitory reactivity of the non-complexed fraction of both of these dominating antiproteases was retained (approximately 85-90%). Thus, a selective inactivation of synovial alpha 1-antitrypsin could not be demonstrated. alpha 1-Anti-chymotrypsin revealed electrophoretic homogeneity in all synovial fluids. Electrophoretic heterogeneity of the plasmin inhibitor antiplasmin was detected in the majority of synovial fluids indicating plasmin activation. The existence of a protease-antiprotease imbalance in the rheumatoid joint was indicated by the high degree of saturation of alpha 2-macroglobulin and a cleavage of C3 in rheumatoid synovial fluids.

Characterization and comparison of poly(adenosine dephosphoribose) synthesis and DNA synthesis in nucleotide-permeable cells

Using eukaryotic cells that have been rendered permeable to exogenously supplied nucleotides, we have characterized the activity of the poly(adenosine diphosphoribose) (poly(ADPR)) synthesis system and compared it to the DNA synthesis complex. The synthesis of poly(ADPR) is dependent on the presence of NAD and Mg2+. It does not require ATP, NaF or a monovalent cation. It is inhibited by N-ethylmaleimide. The reaction product conforms to the nuclease susceptibilities expected for poly(ADP ribose) in that it is degraded by venom phosphodiesterase but not by DNAase of RNAase. A comparison of the effects of inhibitors of poly(ADPR) synthesis and DNA synthesis clearly distinguishes between the two enzymatic systems. Nicotinamide, 5-methyl nicotinamide, thymidine, 5-bromo deoxyuridine, adenosine diphosphoribose, caffeine and formycin all inhibit poly(ADPR) synthesis but not DNA synthesis. In contrast, araCTP, cytembena and phosphonoacetic acid all inhibit DNA synthesis but not poly(ADPR) synthesis. Addition of DNAase to the permeable cells causes a marked stimulation of poly(ADPR) synthesis. L cells in logarithmic growth were found to have high levels of activity of the DNA synthesis complex and low levels of activity of the poly(ADPR) synthesis system. In contrast, cells at plateau phase density demonstrate a decrease in the activity of the DNA synthesis complex and a marked increase in activity of the poly(ADPR) synthesis system. When examined in the presence of added DNAase, the activity of the poly(ADPR) synthesis system is the same in cells obtained from log or plateau phase cultures. This indicates that the physiologic activity of the enzyme varies while the total amount of enzyme remains constant. When the permeable cells are allowed to synthesize both poly(ADPR) and DNA simultaneously, the synthesis of one polymer has no effect on the rate of synthesis of the other.