Effect of Thromboplastins and Instrumentation on the Prothrombin Time Test: Implications for National Standards

Author(s):  
B.L. Evatt ◽  
D. Triplett ◽  
J. Koepke

The independent effects that different thromboplastins and types of methods have on prothrombin time were studied by analyzing data from a 1977 proficiency testing survey of 2735 laboratories. Each laboratory received three plasma samples with prothrombin times of approximately 12, 16 and 24 seconds which represented normal, partially anticoagulated, and fully anticoagulated plasma respectively. Combinations of 12 different instruments and 12 different thromboplastins were used by the laboratories in evaluating the samples. As determined by a two-way analysis of variance, both the type of thromboplastin and the type of instrument have similar effects upon the prothrombin time. When the mean prothrombin time corrected for independent effects of thromboplastin and method are plotted against the overall mean prothrombin times of each of the three types of plasma samples, the linear relationship between the two is obvious. These relationships can used to convert to a common scale a prothrombin time obtained with any thromboplastin method combination and provides a means for standardizing the prothrombin time test. Retrospective, analysis of data obtained from individual proficiency testing surveys in 1976, 1977, and 1978 suggests that the relationships remained constant during those years. These data suggest that the relationship of any thromboplastin to a thromboplastin standard should be determined independently of the method effect.

1970 ◽  
Vol 30 (2) ◽  
pp. 583-587 ◽  
Author(s):  
Albert V. Carron

The present report is based on reanalysis of data of Marisi (1969) in order to examine the relationship of consistency of motor response among the component responses of a single motor task. 120 high school Ss were tested on a special task, the rho. A single trial on this motor task can be logically separated into three component motor responses: reaction time, a short circular movement, and a short linear movement. The results indicated that consistency of motor response was moderately reliable within the response components but tended to be response-component specific. Further, both the reliability and specificity of motor-response consistency were independent of the size of the mean performance scores.


2007 ◽  
Vol 8 (4) ◽  
pp. 249-260 ◽  
Author(s):  
Barbara Waag Carlson ◽  
Virginia J. Neelon ◽  
John R. Carlson ◽  
Marilyn Hartman ◽  
Sunil Dogra

The aim of this exploratory study was to examine the relationship of electroencephalogram (EEG) arousals to breathing patterns and the relationship of both arousals and breathing patterns to arterial oxygenation during sleep in older adults. Five older adults were monitored using standard polysomnography. Records were divided into 5-min segments and breathing patterns identified based on the level of respiratory periodicity and the variability in the frequency of breathing cycles. Standard criteria were used to determine sleep states and occurrence of EEG arousals. High respiratory periodicity was seen in 23% of the segments, whereas 24% had low respiratory periodicity with minimal variability in the frequency of breathing (Type A low respiratory periodicity) and 53% had low respiratory periodicity with high variability in the frequency of breathing (Type B low respiratory periodicity). Nearly all (97%) segments with high respiratory periodicity had EEG arousals, whereas fewer segments (33%) with low respiratory periodicity had arousals, regardless of the stage of sleep. Desaturations occurred more often in segments with high respiratory periodicity, F (2,4) = 57.3, p < .001, but overall, the mean SaO2 of segments with high respiratory periodicity did not differ from levels seen in segments with low respiratory periodicity, F( 2,4) = 0.77, ns. Our findings suggest that high respiratory periodicity is a common feature of EEG arousals and, in older adults, may be important for maintaining oxygen levels during desaturations during sleep.


BMJ Open ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. e017058 ◽  
Author(s):  
Alba Sánchez-Mascuñano ◽  
Cristina Masuet-Aumatell ◽  
Sergio Morchón-Ramos ◽  
Josep M Ramon

ObjectivesThe aim of this study is to analyse the relationship between smoking andaltitude mountain sicknessin a cohort of travellers to 2500 metres above sea level (masl) or higher.SettingTravel Health Clinic at the Hospital Universitari de Bellvitge, in Barcelona, Spain.ParticipantsA total of 302 adults seeking medical advice at the travel clinic, between July 2012 and August 2014, before travelling to 2500 masl or above, who agreed to participate in the study and to be contacted after the trip were included. Individuals who met the following criteria were excluded: younger than 18 years old, taking carbonic anhydrase inhibitors for chronic use, undergoing treatment with systemic corticosteroids and taking any medication that might prevent or treat altitude mountain sickness (AMS) prior to or during the trip. The majority of participants were women (n=156, 51.7%). The mean age was 37.7 years (SD 12.3). The studied cohort included 74 smokers (24.5%), 158 (52.3%) non-smokers and 70 (23.2%) ex-smokers. No statistical differences were observed between different sociodemographic characteristics, constitutional symptoms or drug use and smoking status.OutcomesThe main outcome was the development of AMS, which was defined according to the Lake Louise AMS criteria.ResultsAMS, according to the Lake Louise score, was significantly lower in smokers; the value was 14.9%, 95% CI (6.8 to 23.0%) in smokers and 29.4%, 95% CI (23.5 to 35.3%) in non-smokers with an adjusted OR of 0.54, 95% CI (0.31 to 0.97) independent of gender, age and maximum altitude reached.ConclusionsThese results suggest that smoking could reduce the risk of AMS in non-acclimated individuals. Further studies should be performed in larger cohorts of travellers to confirm these results. Despite the results, smoking must be strongly discouraged because it greatly increases the risk of cardiorespiratory diseases, cancer and other diseases.


2013 ◽  
Vol 71 (4) ◽  
pp. 216-219 ◽  
Author(s):  
Carlos Cosentino ◽  
Yesenia Nuñez ◽  
Luis Torres

Introduction: Non-motor symptoms in Parkinson's disease are often not well recognized in clinical practice. Non-motor symptoms questionnaire (NMSQuest) is a simple instrument that allows patients or caregivers to report non-motor symptoms in a practical manner. Objective: We attempted to determine the prevalence of non-motor symptoms in three hundred Parkinson's disease outpatients. Results: The mean total non-motor symptoms was 12.41, ranging from 0 to 27 of a maximum of 30. At least one was present in 99.3% of patients. A progressive increase in mean total score was observed across each 5-year interval. Depression domain scored the most “positive” answers while urinary and anxiety /memory were secondly and thirdly most prevalent respectively. Conclusion: The large number of patients included in this study allowed evaluation of the occurrence of non-motor symptoms in early and advanced disease in addition to the relationship of these kinds of symptoms with progression of disease.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A248-A248
Author(s):  
Kristi Porterfield-Pruss ◽  
Denise Willis ◽  
Beverly Spray ◽  
Supriya Jambhekar

Abstract Introduction Limited evidence suggests a familial association of OSA. It is not known how often children who require positive airway pressure (PAP) devices have a family member with OSA or that requires PAP. It is felt that PAP adherence in children is affected by PAP adherence in parents. We wanted to explore the relationship of OSA in children requiring PAP to OSA in immediate family members as well as the association of obesity and adherence between children and family members. Methods Caregivers of children who utilize PAP devices at home were invited to complete an electronic questionnaire regarding family history of OSA. Descriptive statistics were utilized to summarize results. Results The study was completed by 75 participants. The majority of children were male (64%, 48/75), black (47%, 35/75) and non-Hispanic (88%, 66/75). The mean age was 11.8 years (median 13) and mean BMI was 32.8 (median 29.8). The mean AHI on the diagnostic polysomnogram was 28.4 events per hour (median 15.3). Mean adherence to PAP &gt; 4 hours per night was 56.5 (Median 68.2). Most, 87% (65/75), have other underlying medical problems. Twenty-four percent (18/75) have a biological father with OSA of whom 61% (11/18) are considered moderately/extremely obese. Of mothers, 13% (10/75) have OSA and 70% (7/10) are obese. Overall, 29% (22/75) had either a paternal (11%, 8/75) or maternal (19%, 14/75) grandfather with OSA of which 36% (8/22) are obese. For grandmothers, 31% (23/75) have OSA and 22% (5/23) are obese with more being paternal (19%, 14/75) compared to maternal (12%, 9/75). Of the 73 total family members reported to have OSA, 86% (63/73) use PAP and most (65%, 41/63) use it for &gt; 4 hours every night. Few participants had siblings with OSA. Conclusion There were more fathers with OSA than mothers, but mothers were reported to be obese more often. Grandparents were reported to have OSA but were reported to be obese less often than parents. Maternal grandparents with OSA were reported to be obese more than paternal grandparents. The majority of family members with OSA who use CPAP report nightly use. Support (if any):


1986 ◽  
Vol 49 (2) ◽  
pp. 110-111 ◽  
Author(s):  
DANIEL R. SAMPLES ◽  
SUSAN L. DILL ◽  
RONALD L. RICHTER ◽  
CHARLES W. DILL

Individual milk samples from 32 cows were analyzed to determine the relationship between somatic cell concentration and total sulfhydryl concentration (cysteine plus reduced cystine). A significant relationship was detected between somatic cell count, which ranged from 1.7 × 104 to 1.0 × 107 cells/ml, and total sulfhydryls per gram of milk protein. The regression equation, total sulfhydryls/g of milk protein = 31.96 + 7.99 (log10 somatic cell count) with r2 = 0.19, was calculated. The mean total sulfhydryl concentration was 73.1 μmol/g of protein. The minimal effect of somatic cell concentration on total sulfhydryl concentration indicates that somatic cell concentration should have little influence on chemical parameters of milk protein determined by sulfhydryl analysis when proper experimental controls are used.


1978 ◽  
Vol 15 (4) ◽  
pp. 532-544 ◽  
Author(s):  
Jacob Jacoby ◽  
Robert W. Chestnut ◽  
William A. Fisher

A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of available information actually acquired was 2%, and (2) information search was concentrated on six of the 35 available information dimensions; increased information acquisition was related (3) positively to the product's importance for the individual, (4) positively to being an optimizer rather than a satisficer, (5) positively to high amounts of past purchasing experience with the product, and (6) negatively to attitudinal brand loyalty.


1988 ◽  
Vol 59 (03) ◽  
pp. 455-463 ◽  
Author(s):  
Freshteh Naghibi ◽  
Yangsook Han ◽  
W Jean Dodds ◽  
Charles E Lawrence

SummaryActivated partial thromboplastin times accumulated from two proficiency testing surveys were analyzed to determine simultaneously the effects of the method and reagent used. Prothrombin time results were reevaluated concomitantly for comparison.A robust two-way analysis of variance was applied to determine the effect of method and reagent on APTT results. The effect of the reagent and method on the ratio of abnormal to normal plasma clotting times was determined. We found a substantial difference in ratios for the PT using different reagents on the same instrument. There was an even larger effect of reagents on APTT ratios.Our finding of substantial reagent effects for the PT and APTT clearly support the need for standardization. We found standardization to be feasible only for the PT, and only if applied in a form consistent with the inherent error structure of the data. For the APTT the present methodology and plasma samples did not achieve consistent standardization.


1992 ◽  
Vol 160 (6) ◽  
pp. 788-792 ◽  
Author(s):  
Sunjai Gupta ◽  
Robin M. Murray

This paper presents new analyses of data from two multicentre studies carried out by the WHO. The morbid risk of developing schizophrenia, as broadly defined by the Determinants of Outcome Study, was positively related to the mean daily range of temperature. The outcome of schizophrenia, as determined by the International Pilot Study of Schizophrenia, was found to be positively related to mean environmental temperature. Further studies are needed to examine the relationship of geographical and climatic variables to schizophrenia in order to complement what is already known about the role of sociocultural factors.


1993 ◽  
Vol 12 (2) ◽  
pp. 180-187 ◽  
Author(s):  
Xiao Jun Li ◽  
Paul Dunham

This study investigated the effect of secondary school physical education on fitness load. Fitness load was defined as the product of the mean heart rate above threshold (144 bpm) and fitness time (the duration of the heart rate above threshold). The relationship of fitness load and skill level of students was also studied. Teachers of 24 classes classified students as having high, moderate, or low skill ability. Seventy-two students, 1 from each skill level in each class, wore heartwatches to record heart rate at 15-s intervals. Student behavior was videotaped and coded. Twenty-one percent of the classes produced an overload effect, and 79% did not. The highly and moderately skilled students achieved fitness load more frequently than their lower skilled colleagues. The relationship between fitness load and percentage of time exercising was r = .66, indicating 44% common variance.


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