CIRCADIAN CHANGES IN THE ANTICOAGULANT EFFECT OF HEPARIN. PHARMACODYNAMIC AND PHARMACOKINETIC EFFECT

1987 ◽  
Author(s):  
H A Decousus ◽  
M F Scully ◽  
J Reynaud ◽  
E Arnaud-Crozat ◽  
C Boissier ◽  
...  

Six patients, with thromboembolic arterial disease, were prospectively studied to assess the influence of the time of injection of a constant dose of calcium heparin (Choay ), given subcutaneously, on the level of heparin measured by APTT and anti-Xa assay. For each patient, the initial dose of heparin was adjusted by APTT 6h after a morning injection to 1.5 and 2.5 times control. Dose was then kept constant. Four randomized times of injection were tested (8am, 4pm, 8pm and 12pm), in each patient acting as his own control. Blood was sampled via a cannula, at Oh, 2h, 3h,4h,5h,6h, 8h, lOh and 12h after injection. The mean APTT and anti-Xa values for the evening injections (8pm and 12pm) were higher than for the morning injection (8am), at 2h until lOh after injection. These differences were significant (analysis of variance:p<0.001) and reached almost 30 seconds for mean APTT values measured 4h, 5h and 6h after injection. For the afternoon injection (4 pm) the mean APTT and anti-Xa values were intermediate but significantly different from all the other times of injection (analysis of variance: p<0.01).Blood was sampled also on two consecutive days at 12am and 12pm from eight patients receiving heparin subcutaneously for treatment of DVT (administered at 6am and 6pm respectively). Heparin levels by APTT, TT and three antifactor Xa methods (Heptest, Hepaclot, Chromogenic) were significantly higher at night than morning (analysis of variance p<0.005). Cosinor analysis confirmed these results are consistent with circadian variation as we have previously reported after continuous infusion of UF heparin (Br. Med. J., 1985, 290, 341-344). The observed variation was found to be a resultant of a pharmacodynamic effect (circadian variation in assay response to heparin) and pharmacokinetic effect (circadian variation in 99m Tc-heparin clearance). Such circadian variation should be taken into account when deciding heparin dosage.

1988 ◽  
Vol 119 (1) ◽  
pp. 111-116 ◽  
Author(s):  
G. J. King ◽  
R. Rajamahendran

ABSTRACT Plasma progesterone concentrations were compared in cyclic (n = 12), pregnant (n =12), oestradiol-induced pseudopregnant (n=12) and hysterectomized gilts (n=10) between days 8 and 27 after oestrus. The results were grouped into periods covering days 8–13, 14–20 and 21–27 and analysed by least-squares analysis of variance. Plasma progesterone concentrations were significantly (P<0·001) higher in hysterectomized compared with other groups between days 8 and 13. Progesterone concentrations declined rapidly after day 14 in cyclic females and gradually in the other groups. Throughout the third and fourth weeks the mean progesterone concentrations for hysterectomized animals were consistently higher than for pseudopregnant animals (P<0·05). The pregnant group means were below but not significantly different from the hysterectomized means in both of the last two periods. The greater progesterone concentrations in hysterectomized gilts indicated that secretion is high without any conceptus-produced or -mediated luteotrophin, and corpora lutea in cyclic, pregnant or pseudopregnant gilts may never reach full secretory potential. J. Endocr. (1988) 119, 111–116


2005 ◽  
Vol 19 (4) ◽  
pp. 256-260 ◽  
Author(s):  
Maria Francisca Thereza Borro Bijella ◽  
Fernanda Lourenção Brighenti ◽  
Maria Fernanda Borro Bijella ◽  
Marília Afonso Rabelo Buzalaf

There is a relationship between the use of fluoride, the reduction of dental caries and the increase of dental fluorosis. The purpose of this study was to analyze the fluoride kinetics in saliva after using the HappydentTM chewing gum, which contains 3.38 mg of fluoride as monofluorophosphate. Fifteen 7-9-year-old volunteers were instructed to chew the gum TridentTM (control) and HappydentTM on different days. Total saliva was collected for 3 minutes, at 0, 3, 6, 9, 15, 30 and 45 minutes after starting chewing. Salivary fluoride was analyzed with a fluoride-specific electrode (Orion 96-09) after acid hydrolysis. The data were analyzed by two-way analysis of variance and by Tukey’s post hoc test (p < 0.05). The mean amounts ± sd (mg) of fluoride released in saliva were 0.276 ± 0.126 and 0.024 ± 0.014 for HappydentTM and TridentTM respectively. The fluoride amount in the saliva samples after the use of Happydent was significantly higher than after the use of TridentTM in all experimental periods, except after 30 and 45 minutes. The high fluoride presence in saliva after the use of Happydent may be significant to prevent dental caries and this should be evaluated in clinical researches. On the other hand, children at an age of risk for dental fluorosis should avoid the use of HappydentTM.


2016 ◽  
Vol 7 (5) ◽  
pp. 985
Author(s):  
Siros Izadpanah ◽  
Maryam Hatemi ◽  
Fatemeh Asadi

Our purpose of the study was to determine the learners’ educational level and their knowledge of true cognate words. 385 had been selected from 3,789 statistical population participated in 2014–2015 at three levels of associate, bachelor, and master of Islamic Azad University as well as teachers of English in English educational institutions in Zanjan (Iran). The participants’ age was between from 18 to 52. The materials were 45 words of true cognate words from 500 words by doing CVR (content validity ratio) and CVI (content validity index) (Lawshe’s table with the index of 88% and 82% respectively). ANOVA (Analysis of variance) was used for studying the effect of educational level on the rate of awareness. The results showed there is no significant difference between the awareness of Associate diploma (A.D.), Bachelor of art (B.A.), and Master of art (M.A.) levels, but there is a significant difference between the level of awareness of teachers group and the other groups in true cognate words. Our result showed that all of them were weak in recognizing true cognate words. It also suggested the mean of true cognates recognized by the students based on educational level had increased trend.


2019 ◽  
Vol 6 (2) ◽  
pp. 113-118
Author(s):  
Hossein Alidadi ◽  
Sima Zamand ◽  
Aliasghar Najafpoor ◽  
Hamid Heidarian ◽  
Aliakbar Dehghan ◽  
...  

This study aimed to investigate the levels of heavy metals in the lipstick products. In general, 30 samples were randomly selected from Mashhad markets. Analysis of variance (ANOVA) and t test were used to compare color and price variables. Based on the results, the mean concentrations of studied elements were as follows: Cd (ND-0.52 µg/g), Cr (0.25-76.35 µg/g), Ni (ND-20.12 µg/g), Zn (ND-224.22 µg/g), Pb (ND-44.77 µg/g), and Hg (ND-0.32 µg/g). The presence of toxic metals in the samples, and on the other hand, continuous use and unintended ingestion of these metals can lead to their biological accumulation in the human body, thereby causing the development of different diseases. Hence, it deems necessary to apply suitable actions for the improvement of quality control over these products.


VASA ◽  
2019 ◽  
Vol 48 (5) ◽  
pp. 413-417 ◽  
Author(s):  
Serge Couzan ◽  
Jean-François Pouget ◽  
Claire Le Hello ◽  
Céline Chapelle ◽  
Silvy Laporte ◽  
...  

Summary. Background: Theoretically progressive compression stockings, which produce a higher compression at the calf than at the ankle level, improve venous return flow without exacerbating peripheral arterial insufficiency (PAD). We aimed to evaluate the short-term tolerance of elastic progressive compression stockings on peripheral arterial vascularisation in patients with symptomatic PAD and associated mild venous insufficiency. Patients and methods: Monocentric, prospective, open pilot study of 18 patients (acceptability study, 6 x 6 plan) evaluating the short-term tolerance of progressive compression stockings (18 ± 2 mmHg at calf and 8 ± 2 mmHg at ankle level) in patients with PAD (ankle brachial index ABI > 0.60 < 0.75) and chronic venous insufficiency (C1s–C4 stages of the CEAP classification). Day 15 tolerance was evaluated by a composite primary criteria comprising: no decrease > 15 % of ABI on each side, no decrease > 15 % of toe brachial index (TBI) on each side and no decrease > 25 % of the number of active plantar flexions performed while standing. Results: The proportion of men was 77.8 %, mean age was 77.3 ± 7.5 years and no patient were diabetic. At inclusion, the mean low ABI was 0.60 ± 0.04 and the mean high ABI was 0.77 ± 0.18. The mean low TBI was 0.32 ± 0.09 and the mean high TBI 0.46 ± 0.15. The mean number of active standing plantar flexions was 33.0 ± 5.0. The majority of the patients were classified in CEAP C2s and C3 classes (class 2: 16.7 %, class C2s: 27.8 %, class C3: 44.4 %, class C4: 5.6 % and class C4s: 5.6 %). Poor tolerance occurred in no patient. By day 30, no patient had worsening of their arterial and venous symptoms. No adverse events occurred during the study. Conclusions: These results suggest a high tolerance of progressive elastic stockings (18 ± 2 mmHg at calf and 8 ± 2 mmHg at ankle level) in symptomatic PAD.


1993 ◽  
Vol 69 (01) ◽  
pp. 035-040 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina

SummaryFour thromboplastin reagents were tested by 18 laboratories in Europe, North-America, and Australasia, according to a detailed protocol. One thromboplastin was the International Reference Preparation for ox brain thromboplastin combined with adsorbed bovine plasma (coded OBT/79), and the second was a certified reference material for rabbit brain thromboplastin, plain (coded CRM 149R). The other two thromboplastin reagents were another rabbit plain brain thromboplastin (RP) with a lower ISI than CRM 149R and a rabbit brain thromboplastin combined with adsorbed bovine plasma (RC). Calibration of the latter two reagents was performed according to methods recommended by the World Health Organization (W. H. O.).The purpose of this study was to answer the following questions: 1) Is the calibration of the RC reagent more precise against the bovine/combined (OBT/79) than against the rabbit/plain reagent (CRM 149R)? 2) Is the precision of calibration influenced by the magnitude of the International Sensitivity Index (ISI)?The lowest inter-laboratory variation of ISI was observed in the calibration of the rabbit/plain reagent (RP) against the other rabbit/plain reagent (CRM 149R) (CV 1.6%). The highest interlaboratory variation was obtained in the calibration of rabbit/plain (RP) against bovine/combined (OBT/79) (CV 5.1%). In the calibration of the rabbit/combined (RC) reagent, there was no difference in precision between OBT/79 (CV 4.3%) and CRM 149R (CV 4.2%). Furthermore, there was no significant difference in the precision of the ISI of RC obtained with CRM 149R (ISI = 1.343) and the rabbit/plain (RP) reagent with ISI = 1.14. In conclusion, the calibration of RC could be performed with similar precision with either OBT/79 or CRM 149R, or RP.The mean ISI values calculated with OBT/79 and CRM 149R were practically identical, indicating that there is no bias in the ISI of these reference preparations and that these reference preparations have been stable since their original calibration studies in 1979 and 1987, respectively.International Normalized Ratio (INR) equivalents were calculated for a lyophilized control plasma derived from patients treated with oral anticoagulants. There were small but significant differences in the mean INR equivalents between the bovine and rabbit thromboplastins. There were no differences in the interlaboratory variation of the INR equivalents, when the four thromboplastins were compared.


1979 ◽  
Vol 42 (04) ◽  
pp. 1073-1114 ◽  

SummaryIn collaborative experiments in 199 laboratories, nine commercial thromboplastins, four thromboplastins held by the National Institute for Biological Standards and Control (NIBS & C), London and the British Comparative Thromboplastin were tested on fresh normal and coumarin plasmas, and on three series of freeze-dried plasmas. One of these was made from coumarin plasmas and the other two were prepared from normal plasmas; in each series, one plasma was normal and the other two represented different degrees of coumarin defect.Each thromboplastin was calibrated against NIBS&C rabbit brain 70/178, from the slope of the line joining the origin to the point of intersection of the mean ratios of coumarin/normal prothrombin times when the ratios obtained with the two thromboplastins on the same fresh plasmas were plotted against each other. From previous evidence, the slopes were calculated which would have been obtained against the NIBS&C “research standard” thromboplastin 67/40, and termed the “calibration constant” of each thromboplastin. Values obtained from the freeze-dried coumarin plasmas gave generally similar results to those from fresh plasmas for all thromboplastins, whereas values from the artificial plasmas agreed with those from fresh plasmas only when similar thromboplastins were being compared.Taking into account the slopes of the calibration lines and the variation between laboratories, precision in obtaining a patient’s prothrombin time was similar for all thromboplastins.


1985 ◽  
Vol 54 (04) ◽  
pp. 739-743 ◽  
Author(s):  
Federica Delaini ◽  
Elisabetta Dejana ◽  
Ine Reyers ◽  
Elisa Vicenzi ◽  
Germana De Bellis Vitti ◽  
...  

SummaryWe have investigated the relevance of some laboratory tests of platelet function in predicting conditions of thrombotic tendency. For this purpose, we studied platelet survival, platelet aggregation in response to different stimuli, TxB2 and 6-keto-PGFlα production in serum of rats bearing a nephrotic syndrome induced by adriamycin. These animals show a heavy predisposition to the development of both arterial and venous thrombosis. The mean survival time was normal in nephrotic rats in comparison to controls. As to aggregation tests, a lower aggregating response was found in ADR-treated rats using ADP or collagen as stimulating agents. With arachidonic acid (AA) we observed similar aggregating responses at lower A A concentrations, whereas at higher AA concentrations a significantly lower response was found in nephrotic rats, despite their higher TxB2 production. Also TxB2 and 6-keto-PGFlα levels in serum of nephrotic rats were significantly higher than in controls. No consistent differences were found in PGI2-activity generated by vessels of control or nephrotic rats.These data show that platelet function may appear normal or even impaired in rats with a markedly increased thrombotic tendency. On the other hand, the significance of high TxB2 levels in connection with mechanisms leading to thrombus formation remains a controversial issue.


2004 ◽  
Vol 9 (3) ◽  
pp. 233-240 ◽  
Author(s):  
S. Kim

This paper describes a Voronoi analysis method to analyze a soccer game. It is important for us to know the quantitative assessment of contribution done by a player or a team in the game as an individual or collective behavior. The mean numbers of vertices are reported to be 5–6, which is a little less than those of a perfect random system. Voronoi polygons areas can be used in evaluating the dominance of a team over the other. By introducing an excess Voronoi area, we can draw some fruitful results to appraise a player or a team rather quantitatively.


1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (&lt;0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.


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