scholarly journals The Role of Cyclic Nucleotides and Prostaglandins in the Mechanisms of Aggregation of Thrombocytes

1977 ◽  
Author(s):  
S. V. Andreev ◽  
A. A. Kubatiev ◽  
Ya. D. Mamedov
Keyword(s):  
Comparative Study ◽  
Cyclic Nucleotides ◽  
Initial Level ◽  
Proteolytic Enzymes ◽  
Adenyl Cyclase ◽  
The Other ◽  
Initial Link ◽  
Stimulation Of

In a comparative study into the mechanisms of aggregation of thrombocytes under the influence of various agents, two types of reactions were established, one realized through the system of cyclic 3′5-AMP and the other, through the system of cyclic 3′5-GMP. The former type of reaction was observed when ADP and thrombin were used as aggregation inductors; the latter was induced by serotonin. The initial link in the development of aggregation of thrombocytes induced by ATP and thrombin was an increase in the level of prostaglandin EI (by 32%), under the effect of which the activity of adenyl cyclase rose more than by 41%, and the amount of 3’5-cAMP increased by almost 180% as compared with the initial level. Unlike ADP and thrombin, stimulation of thrombocytes with serotonin brought about, as a rule, an increase in the level of prostaglandins F2 (by 60%) , which subsequently led to activation of guanyl cyclase and marked augmentation in the content of 3′5-cGMP (by 300%). The application of proteolytic enzymes with thrombolytically oriented properties caused inhibition of biosynthesis of prostaglandins and cyclic nucleotides with a clearcut disaggregating effect.

scholarly journals Entrepreneurship in small and medium-sized enterprises: Comparative study between Slovakia and Poland for the years 2001–2007

2008 ◽  
Vol 54 (No. 8) ◽  
pp. 358-366 ◽  
Author(s):  
I. Ubrežiová ◽  
K. Wach ◽  
J. Horváthová
Keyword(s):  
Comparative Study ◽  
National Economy ◽  
Transition Economy ◽  
The Other ◽  
Regional Structure ◽  
Main Attention ◽  
Supporting System ◽  
Other Hand ◽  
The Impact

The main attention of the submitted paper is devoted to the comparison of development of entrepreneurship in Slovak and Polish small and medium-sized he enterprise sector. The conditions for blooming entrepreneurship are created in the national economy. Especially the role of SMEs in the transition economy, both in Slovakia and Poland, has the impact on SMEs. The entrepreneurship of small and medium-sized enterprises is extended in the whole Slovakia. From the viewpoint of the regional structure, most enterprises are located in the Bratislavský region (30.4%), Košický region (11.8%), Žilinský region (10.1%) and Trenčianský region (10.1%). On the other hand, the least of enterprises were registered in the Nitrianský region (8.9%), Trnavský region (9.2%) and Banskobystrický region (9.6%). Small and medium entrepreneurship is diversed throughout Poland. The average small and medium entreprenership ratio is 44.5, while the highest is in the Mazowieckie region – 55.2% and the lowest in the Podkarpackie region – 30 %. The supporting system for private entrepreneurship in both countries, Slovakia and Poland, is very similar and the entrepreneurs are satisfied with its offer and help.

scholarly journals The Role of Legal Culture in Corruption Eradication Effort (A Comparative Study of Indonesian and Japanese Corruption Crime Handling)

2019 ◽  
Vol 3 (1) ◽  
pp. 25-34
Author(s):  
Laely Wulandari ◽  
Lalu Parman
Keyword(s):  
Law Enforcement ◽  
Comparative Study ◽  
Significant Role ◽  
Law Enforcement Officers ◽  
Legal Culture ◽  
The Other ◽  
The One ◽  
Strong Culture ◽  
Eradication Effort

In a comparative study of Eradicating Corruption in Indonesia and Japan appears that law culture plays a significant role. Indonesia has special institution that deals with corruption while Japan does not have it. Nevertheless, cases of corruption in Indonesia are higher than in Japan. This is due to the Indonesian culture of ewuh pakewuh, reluctant, and has two different views in dealing with corruption. On the one hand, Indonesia rejects corruption, but on the other hand, it commits actions that support corruption. Meanwhile, Japan has a strong culture of shame for committing law violations both at the community level and law enforcement officers.  

Transepithelial Potential Changes During Stimulation of Isolated Salivary Glands with 5-Hydroxytryptamine and Cyclic Amp

1972 ◽  
Vol 56 (1) ◽  
pp. 139-153
Author(s):  
MICHAEL J. BERRIDGE ◽  
WILLIAM T. PRINCE
Keyword(s):  
Cyclic Amp ◽  
Salivary Glands ◽  
Electrical Response ◽  
Cation Transport ◽  
Anion Transport ◽  
Adenyl Cyclase ◽  
Positive Potential ◽  
Dose Dependent ◽  
Stimulation Of

1. The role of cyclic AMP in mediating the action of 5-HT on salivary glands has been studied by measuring transepithelial potentials. 2. The lumen of unstimulated glands is 4 mV positive but becomes 12 mV negative after treatment with 5-HT (10-8M). Both the potential and the secretory responses to 5-HT are dose-dependent over the same concentration range. 3. The electrical response of salivary glands to cyclic AMP is qualitatively different to that of 5-HT; instead of going negative the potential goes more positive. 4. An increase in positive potential is also observed after treatment with theophylline (10-2M), or when glands are stimulated with 5-HT in a chloride-free saline. 5. These results are consistent with the idea that 5-HT has two actions. One is to stimulate the enzyme adenyl cyclase to synthesize cyclic AMP, which, in turn, stimulates cation transport. The other is to increase anion transport by a mechanism which is independent of cyclic AMP.

Further Evidence For The Role Of Platelet Surface-Associated Fibronectin In The Stimulation By Collagen

1981 ◽  
Author(s):  
H B Bensusan ◽  
D Holderbaum ◽  
K G Khor ◽  
M Orlando
Keyword(s):  
Human Plasma ◽  
Platelet Membrane ◽  
The Other ◽  
Mouse Tumor ◽  
Fab Fragment ◽  
Platelet Surface ◽  
Published Evidence ◽  
Dependent Inhibition ◽  
Stimulation Of

We have previously published evidence showing that 1) fibronectin (FN) can be extracted from intact platelets, 2) collagen fibers preincubated with plasma FN do not stimulate platelets, and 3) antibodies to human plasma FN stimulate platelets. We now present evidence that platelet stimulation by anti-human plasma FN antibodies depends upon antigen-antibody compatibility in platelets from individual donors. Antibodies to human plasma FN produced in rabbit and goat were purified on affinity columns of FN. Platelets from some donors were stimulated by antibodies from both species, some by one but not the other, and some by neither. These results suggest that there is a genetic variability of human platelet associated FN, presumably residing in the carbohydrate side chains. For this reason, donor-antibody compatibility must be considered in studies of platelet-membrane FN using antibodies. F(ab’)2 fragments of goat antibody caused stimulation of platelets from compatible donors. These data show that the stimulation of platelets is not due to any form of immune complex, which requires the Fc portion of the antibody. The Fab’ fragment caused no stimulation of platelets. However, when varying amounts of these fragments were preincubated with platelets, a dose-dependent inhibition of stimulation by collagen was seen. These data clearly indicate a role of platelet- membrane associated FN in the stimulation of the platelet by collagen. Three lines of monospecific antibodies were derived from hybridoma-induced mouse tumor ascites. Two of the antibodies from these lines stimulated the platelets from all donors while the other stimulated none. Furthermore, the plasma FN from all donors was shown to be antigenic to all antibodies of the goat whether or not the antibody stimulated their platelets. This fact, together with the observation that one monoclonal antibody caused no response, suggests that a portion of the platelet-membrane associated FN molecule is somehow masked or buried.

scholarly journals The effect of urea synthesis on extracellular pH in isolated perfused rat liver

1986 ◽  
Vol 236 (1) ◽  
pp. 261-265 ◽  
Author(s):  
D Häussinger ◽  
W Gerok ◽  
H Sies
Keyword(s):  
Liver Perfusion ◽  
Hepatic Metabolism ◽  
The Other ◽  
Isolated Perfused Rat Liver ◽  
Urea Synthesis ◽  
Perfused Rat Liver ◽  
Extracellular Acidification ◽  
Isolated Liver ◽  
Stimulation Of

In a non-recirculating system of isolated liver perfusion, stimulation of urea synthesis by NH4Cl is followed by a decrease of effluent pH by up to 0.2 pH unit. This effect is not observed when urea synthesis is inhibited by amino-oxyacetate or norvaline. When the urea formed by the liver is immediately hydrolysed with urease before the effluent perfusate reaches the pH electrode, the urea-synthesis-induced acidification is no longer observed. This indicates that accompanying alterations in hepatic metabolism after stimulation of urea synthesis, such as increased energy provision and consumption, are not responsible for the extracellular acidification, but that the effect is due to the formation of urea itself. The acidification of the extracellular space after stimulation of urea synthesis by NH4Cl is quantitatively explained by the consumption of 2 mol of HCO3-/mol of urea formed: 1 mol being incorporated into urea, the other being protonated to yield CO2 and H2O. The data match the theoretically predicted HCO3- consumption during ureogenesis and underline the role of hepatic urea synthesis for disposal of HCO3- by converting it into the excretable products CO2 and urea.

scholarly journals Roles of Rho Guanosine 5′-Triphosphatase A, Rho Kinases, and Extracellular Signal Regulated Kinase (1/2) in Prostaglandin E2-Mediated Migration of First-Trimester Human Extravillous Trophoblast

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 1243-1251 ◽  
Author(s):  
Catalin Nicola ◽  
Andrei Chirpac ◽  
Peeyush K. Lala ◽  
Chandan Chakraborty
Keyword(s):  
Chorionic Villus ◽  
Rho Kinase ◽  
First Trimester ◽  
The Other ◽  
Extravillous Trophoblast ◽  
Small Interfering Rnas ◽  
Rock Inhibitor ◽  
Trophoblast Migration ◽  
Stimulation Of

Prostaglandin (PG) E2 may regulate invasiveness of human placenta because we previously reported stimulation of migration of placental trophoblasts by PGE2 acting through PGE receptor (EP)-1 and activating calpain. RhoA GTPase and its important effector Rho kinase (ROCK) have also been previously shown to regulate trophoblast migration. Using immortalized HTR-8/SVneo trophoblast cells and first-trimester human chorionic villus explant cultures on matrigel, we further examined the role of RhoA/ROCK and MAPK (ERK1/2) pathways on PGE2-mediated stimulation of trophoblast migration. Migration of cytotrophoblasts was shown to be inhibited by treatment of the trophoblast cell line and chorionic villus explants with either cell-permeable C3 transferase or selective RhoA small interfering RNA. These inhibitions were significantly mitigated by the addition of PGE2, an EP1/EP3 agonist or an EP3/EP4 agonist, suggesting that RhoA plays an important role in trophoblast migration but may not be obligatory for PGE2 action. Treatment of HTR-8/SVneo cells with nonselective ROCK inhibitor Y27632 or ROCK small interfering RNAs inhibited migration of these cells, which could not be rescued with PGE2 or the other two EP agonists, suggesting the obligatory role of ROCK in PGE2-induced migratory response. Furthermore, U0126, an inhibitor of MAPK kinases MEK1 and MEK2, abrogated PGE2-induced migration of trophoblasts, and PGE2 or the other two EP agonists stimulated ERK1/2 activation in trophoblasts, which was not abrogated by pretreatment with C3 transferase, indicating that ERK signaling pathway is an efficient alternate pathway for RhoA in PGE2-mediated migration of trophoblasts. These results suggest that ROCK and ERK1/2 play more important roles than RhoA in PGE2-mediated migration stimulation of first-trimester trophoblasts.

scholarly journals Stimulating Emotional Intelligence in Seniors: The Peci-Pm Program

2014 ◽  
Vol 4 (3) ◽  
pp. 329-339
Author(s):  
Mª del Carmen Pérez-Fuentes ◽  
Mª del Mar Molero ◽  
José J. Gázquez ◽  
Francisco J. Soler
Keyword(s):  
Emotional Intelligence ◽  
Older People ◽  
Senior Citizens ◽  
Cognitive Stimulation ◽  
The Other ◽  
Before And After ◽  
Interpersonal Dimension ◽  
Emotional Intelligence Inventory ◽  
Stimulation Of

The Cognitive Stimulation and Emotional Intelligence for Seniors Program (PECI-PM), combines cognitive stimulation with intervention and stimulation of aspects related to emotional intelligence. The purpose of this study was to analyze the emotional intelligence results of the first stage of PECI-PM implementation. A sample of 28 program users who had completed 20 sessions and participated in the two evaluations (pre-post) was employed for this. Emotional Intelligence was evaluated before and after intervention using the Inventario Breve de Inteligencia Emocional para Mayores [Brief Emotional Intelligence Inventory for Senior Citizens] (EQ-i-M20). After intervention with the PECI-PM, improvement was observed in most of the emotional intelligence dimensions (Intrapersonal, Interpersonal, Adaptability and Mood). In the Stress Management dimension, there was no change in scores after intervention, which leads us to reconsider the weight of this emotional intelligence dimension in the older population. On the other hand, the role of the Interpersonal dimension, which correlates significantly with other emotional intelligence factors (Intrapersonal and Adaptability) in older people, should be emphasized.

scholarly journals Effects of cyclic adenosine 3',5'-monophosphate on photoreceptor disc shedding and retinomotor movement. Inhibition of rod shedding and stimulation of cone elongation.

1982 ◽  
Vol 79 (5) ◽  
pp. 775-790 ◽  
Author(s):  
J C Besharse ◽  
D A Dunis ◽  
B Burnside
Keyword(s):  
White Light ◽  
Cyclic Nucleotides ◽  
Pigment Epithelium ◽  
Phosphodiesterase Inhibitors ◽  
Light Treatment ◽  
The Other ◽  
Rod Photoreceptors ◽  
Pigment Epithelial ◽  
Stimulation Of

As a test of the hypothesis that cyclic nucleotides play a role in the regulation of retinomotor movements and disc shedding in the photoreceptor-pigment epithelial complex, we have used an in vitro eyecup preparation that sustains both disc shedding and cone retinomotor movements, Eyecups were prepared in white light from animals in which both shedding and cone movement had been blocked by 4 d of constant-light treatment. In eyecups incubated for 3 h in light, disc shedding was negligible and cones remained in the light-adapted (contracted) position. In eyecups incubated in darkness, however, a massive shedding response (dominated by rod photoreceptors) was induced, and at the same time cone photoreceptors elongated to their dark-adapted position. In eyecups incubated in light dbcAMP promoted cone elongation and thus mimicked darkness; the dbcAMP effect was potentiated by the phosphodiesterase inhibitors papaverine and 3-isobutylmethylxanthine. In eyecups incubated in darkness, on the other hand, both phosphodiesterase inhibitors and dbcAMP reduced the phagosome content of the pigment epithelium. The effects of dbcAMP on the cone elongation and rod shedding appear to be specific in that dbcGMP, adenosine, and adenosine 5'-monophosphate had no significant effect. Our results suggest that cAMP plays a role in the regulation of both retinomotor movements and disc shedding.

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