ADP-Induced Platelet Aggregation as a Function of Age in Healthy Humans

1989 ◽  
Vol 61 (03) ◽  
pp. 490-492 ◽  
Author(s):  
L Vilén ◽  
S Jacobsson ◽  
H Wadenvik ◽  
J Kutti
Keyword(s):  
Platelet Aggregation ◽  
Matched Control ◽  
Narrow Range ◽  
Careful Selection ◽  
Control Groups ◽  
Healthy Humans ◽  
Similar Association ◽  
Male Subjects ◽  
Age And Sex ◽  
Selection Of

SummaryIn 120 healthy humans (58 males and 62 females) possible differences in platelet aggregability were investigated with respect to age and sex. By using a narrow range of final ADP concentrations (0.2-1.0 μM) primary and secondary aggregation were evaluated. The rate of primary aggregation was shown to be significantly related to increasing age and this was true for both sexes.As regards secondary aggregation the same pattern was seen in the group of male subjects. Thus, among the youngest (<34 years) the frequency of secondary waves was only one third of that encountered among the oldest (>50 years). No similar association was detectable among the female subjects.The present study calls attention to some important issues which should be considered in platelet aggregation studies; the interpretation of data obtained from such studies invariably requires a careful selection of appropriate age- as well as sex-matched control groups.

Platelet Anti-Aggregating Activity and Tolerance of Clopidogrel in Atherosclerotic Patients

1996 ◽  
Vol 76 (06) ◽  
pp. 0939-0943 ◽  
Author(s):  
B Boneu ◽  
G Destelle ◽  
Keyword(s):  
Platelet Aggregation ◽  
Large Scale ◽  
Bleeding Time ◽  
Antithrombotic Activity ◽  
Ambulatory Patients ◽  
Patients At Risk ◽  
Set Up ◽  
Ischemic Events ◽  
Large Scale Clinical Trial ◽  
Selection Of

SummaryThe anti-aggregating activity of five rising doses of clopidogrel has been compared to that of ticlopidine in atherosclerotic patients. The aim of this study was to determine the dose of clopidogrel which should be tested in a large scale clinical trial of secondary prevention of ischemic events in patients suffering from vascular manifestations of atherosclerosis [CAPRIE (Clopidogrel vs Aspirin in Patients at Risk of Ischemic Events) trial]. A multicenter study involving 9 haematological laboratories and 29 clinical centers was set up. One hundred and fifty ambulatory patients were randomized into one of the seven following groups: clopidogrel at doses of 10, 25, 50,75 or 100 mg OD, ticlopidine 250 mg BID or placebo. ADP and collagen-induced platelet aggregation tests were performed before starting treatment and after 7 and 28 days. Bleeding time was performed on days 0 and 28. Patients were seen on days 0, 7 and 28 to check the clinical and biological tolerability of the treatment. Clopidogrel exerted a dose-related inhibition of ADP-induced platelet aggregation and bleeding time prolongation. In the presence of ADP (5 \lM) this inhibition ranged between 29% and 44% in comparison to pretreatment values. The bleeding times were prolonged by 1.5 to 1.7 times. These effects were non significantly different from those produced by ticlopidine. The clinical tolerability was good or fair in 97.5% of the patients. No haematological adverse events were recorded. These results allowed the selection of 75 mg once a day to evaluate and compare the antithrombotic activity of clopidogrel to that of aspirin in the CAPRIE trial.

The Clinical Usefulness of the Platelet Aggregation Test for the Diagnosis of Heparin-Induced Thrombocytopenia

1993 ◽  
Vol 69 (04) ◽  
pp. 344-350 ◽  
Author(s):  
B H Chong ◽  
J Burgess ◽  
F Ismail
Keyword(s):  
Platelet Aggregation ◽  
Heparin Therapy ◽  
Serotonin Release ◽  
Point System ◽  
Control Groups ◽  
Heparin Induced Thrombocytopenia ◽  
Heparin Concentration ◽  
Release Test ◽  
The Mean ◽  
Normal Controls

SummaryThe platelet aggregation test is widely used for the diagnosis of heparin-induced thrombocytopenia (HIT), a potentially serious complication of heparin therapy. We have evaluated its sensitivity and specificity in comparison with those of the 14C-serotonin release test. The sensitivity of the platelet aggregation test was found to vary with the heparin concentration and the donor of the platelets used in the test. The optimal heparin concentrations were between 0.1 and 1.0 U/ml. Using these heparin concentrations, the mean sensitivity varied from 39% (with the least reactive platelets) to 81% (with the most reactive platelets). In comparison, the sensitivity of the release test ranged from 65% to 94%. The specificities of the platelet aggregation test were 82%, 90% and 100% for the following control groups: (1) non-thrombocytopenic patients given heparin, (2) patients with thrombocytopenia due to other causes, and (3) normal controls not given heparin, respectively. The corresponding specificities for the release test was 94%, 90% and 100%. The specificities can be further increased to 100% for all controls with the adoption of a two-point system which defines a positive result as one in which platelet aggregation occurs with a low heparin concentration (0.5 U/ml) but not with 100 U heparin/ml. For optimal results, a two-point platelet aggregation test should be performed with heparin concentrations of 0.5 and 100 U/ml and using platelets of more reactive donors.

Urokinase Antigen in Plasma of Patients with Liver Cirrhosis and Hepatoma

1985 ◽  
Vol 54 (03) ◽  
pp. 617-618 ◽  
Author(s):  
J C Kirchheimer ◽  
K Huber ◽  
P Polterauer ◽  
B R Binder
Keyword(s):  
Liver Cirrhosis ◽  
Liver Disease ◽  
Liver Function ◽  
Matched Control ◽  
Malignant Growth ◽  
Control Groups ◽  
Impaired Liver Function ◽  
Impaired Liver ◽  
Specific Medication ◽  
History Of

SummaryPlasma urokinase antigen levels were studied in 78 patients suffering from liver diseases. Blood was drawn before any specific medication was initiated. Impairment of liver function was comparable in all patients. In both groups of cirrhotic liver disease (alcoholic and non-alcoholic), normal levels of plasma urokinase antigen were found as compared to age-matched control groups. In both groups of patients with hepatomas (with or without a history of liver cirrhosis), however, significantly increased plasma urokinase antigen levels could be determined. These data indicate that an increase in plasma urokinase antigen might rather relate to malignant growth in liver disease than to impaired liver function.

The Quantitation of Platelet Aggregation Induced by Four Compounds: A Study in Relation to Myocardial Infarction

1966 ◽  
Vol 16 (03/04) ◽  
pp. 752-767 ◽  
Author(s):  
J. R O’Brien ◽  
F. C Path ◽  
Joan B. Heywood ◽  
J. A Heady
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Myocardial Infarct ◽  
Control Groups ◽  
The Mean ◽  
Platelet Shape

SummaryMethods for measuring and comparing day to day differences in the response of platelet aggregation in platelet-rich plasma to added ADP, 5-H.T., adrenaline and collagen are reported. Platelet aggregation induced by ADP, 5-H.T. and adrenaline was studied in patients with acute myocardial infarction and in others 3 months to 5 years after an infarct; some were receiving anti-coagulants and others not: these three groups were compared with three control groups. The mean platelet shape was rounder and the response to ADP and to 5-H.T. and one parameter of the response to adrenaline was significantly greater in all groups of patients with myocardial infarct taken together than in the controls. The platelet-rich plasma from patients with recent infarction were most responsive to ADP and 5-H.T. immediately after the infarct. Anti-coagulants had no effect on these tests. However, there was wide variation within the individuals and much overlap between groups, and these tests can only reliably distinguish between groups and not between individuals. The significance of these findings is discussed.

Afterword

2020 ◽  
pp. 680-683
Author(s):  
Janice L. Waldron ◽  
Stephanie Horsley ◽  
Kari K. Veblen
Keyword(s):  
Social Media ◽  
Media Use ◽  
Careful Selection ◽  
Social Media Use ◽  
Pedagogical Tools ◽  
The Future ◽  
User Data ◽  
Selection Of ◽  
Data Surface

We all feel the implications of the force of social media—for good and for ill—in our lives and in our professional world. At the time of this writing, Facebook continues with its struggle to “clean up its act” as more revelations surrounding breaches of trust and hacked user data surface in the news and various countries attempt to hold Facebook to account. Despite this, social media use continues to grow exponentially, and the potential for responsible, ethical, and transparent social media to transform the ways in which we interact with and learn from each other increase with it. As we wait to see what the future holds for social media in society, we are reminded once again that it is the careful selection of pedagogical tools such as social media, as well the guided awareness of the challenges and benefits of those tools, that remains constant, even as tools may change, disappear, or fall out of fashion.

scholarly journals Circulating miRNA-202-3p is a potential novel biomarker for diagnosis of type 1 gastric neuroendocrine neoplasms

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dou Dou ◽  
Xiao-kou Li ◽  
Qi-sheng Xia ◽  
Ying-ying Chen ◽  
Yuan-liang Li ◽  
...  
Keyword(s):  
Clinical Characteristics ◽  
Matched Control ◽  
Future Research ◽  
Control Group ◽  
Neuroendocrine Neoplasms ◽  
Diagnostic Biomarkers ◽  
Standard Curve ◽  
Qrt Pcr ◽  
Age And Sex

Abstract Background Currently, there are no circulating diagnostic biomarkers for gastric neuroendocrine neoplasms (g-NENs). In previous studies, we found that miRNA-202-3p is overexpressed in the tumour tissue of type 1 g-NEN. We speculated that miRNA-202-3p is also likely to be highly expressed in circulating blood. Methods A total of 27 patients with type 1 g-NEN and 27 age- and sex-matched control participants were enrolled in this study. The miRNA-202-3p levels in serum obtained from the participants were measured by qRT‐PCR. The expression level of miRNA-202-3p in the samples was calculated by comparison with a standard curve. Results The clinical characteristics of the patients were similar to those of the patient samples in previous reports. Expression of miRNA-202-3p was significantly higher in the patient group (3.84 × 107 copies/nl) than in the control group (0.635 × 107 copies/nl). The area under the ROC curve (AUC) was 0.878 (95% CI: 0.788–0.968), and the optimal cut-off point was approximately 1.12 × 107 copies/nl. The sensitivity and specificity were 88.9% and 77.8%, respectively. Conclusion This study suggests that miRNA-202-3p is potentially useful as a biomarker of type 1 g-NEN; further investigation and verification should be performed in future research.

Age and sex differences related to platelet aggregation

1980 ◽  
Vol 8 (2) ◽  
pp. 180-181 ◽  
Author(s):  
H. WILLIAM READING ◽  
ROBERTA ROSIE
Keyword(s):  
Sex Differences ◽  
Platelet Aggregation ◽  
Age And Sex

Enlargement of cerebrospinal fluid spaces in long-term benzodiazepine abusers

1987 ◽  
Vol 17 (4) ◽  
pp. 869-873 ◽  
Author(s):  
C. Schmauss ◽  
J.-C. Krieg
Keyword(s):  
Low Dose ◽  
Matched Control ◽  
Control Group ◽  
High Dose ◽  
Withdrawal Therapy ◽  
The Mean ◽  
Dose Dependent ◽  
Dose Dependent Effect ◽  
Age And Sex

SynopsisIn 17 benzodiazepine (BDZ) dependent in-patients a CT scan was performed before initiation of withdrawal therapy. The evaluation of the ventricular to brain ratio (VBR) by standardized and computerized measurements revealed significantly higher mean VBRs for both high-and low-dose BDZ-dependent patients compared to the mean VBR of an age- and sex-matched control group. In addition, the mean VBR of high-dose BDZ-dependent patients (N = 8) was significantly higher than the mean VBR of low-dose BDZ-dependent patients (N = 9). This difference could not be accounted for by the age of the patients or duration of BDZ-dependency and, therefore, suggests a dose-dependent effect of BDZs on the enlargement of internal CSF-spaces. On the other hand, higher values for the width of external CSF-spaces were found to be related to increasing age of the patients and duration of BDZ-dependency.

Catacomb culture wagons of the Eurasian steppes

Antiquity ◽  
2014 ◽  
Vol 88 (340) ◽  
pp. 378-394 ◽  
Author(s):  
N.I. Shishlina ◽  
D.S. Kovalev ◽  
E.R. Ibragimova
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Burial Mound ◽  
Careful Selection ◽  
Southern Russia ◽  
The Subject ◽  
The Individual ◽  
Wheeled Vehicles ◽  
Selection Of ◽  
Catacomb Culture

The origin and development of wheeled vehicles continues to fascinate today no less than when Stuart Piggott (1974) first wrote about the subject inAntiquity40 years ago. A growing number of examples from the steppes of southern Russia and Ukraine are providing new insights into the design and construction of these complex artefacts. A recent example from the Ulan IV burial mound illustrates the techniques employed and the mastery of materials, with careful selection of the kinds of wood used for the wheels, axles and other elements. Stable isotope analysis of the individual interred in this grave showed that he had travelled widely, emphasising the mobility of steppe populations.

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