PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Reference Values”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed1986

Hematology and biochemistry reference values for the ranch fox.

Reference hematology and biochemistry values are presented from a mixed population of 30 silver and red foxes of both sexes, reared and living under fox-farming conditions in southern Ontario. Based on history and physical examination, the animals in this study were clinically healthy at the time of blood collection and maintained under similar husbandry practices. The observations were examined for outliers and Gaussian distribution before and after one of three transformations. Parametric analysis was used to determine lower and upper reference limits. Where observations were not Gaussian, minimum and maximum values are given. These reference values are presented as a usable first approximation of population reference values to assist clinicians and researchers in their interpretation of observations obtained from foxes of similar populations.

Animals↗
PubMed2001

Electrocardiogram reference values for the buzzard in Spain.

Electrocardiographic reference values were established on apparently healthy buzzards (Buteo buteo) in Lugo (Spain) from March 1997 to June 1999. All birds were anesthetized with isofluorane and placed in dorsal recumbence. The standard and augmented unipolar limb leads electrocardiograms were recorded in 65 buzzards. The wave forms were analyzed in lead II at 50 mm/sec and at 1 cm = 1 mV to determine P, PR, QRS, T and QT durations and P, QRS and T amplitudes. The polarity of each wave form was tabulated in all leads. The mean electrical axis (MEA) for the frontal plane was calculated using leads II and III. The mean heart rate was 325.2 +/- 52.9 beats/min. In lead II, the P wave was positive, the dominant pattern of QRS complex was QS and the T wave was always positive. The average value of the MEA was -99.2 +/- 7.7 degrees. Establishment of normal electrocardiogram (EKG) values will facilitate a better understanding of EKG changes seen in many diseases of these birds.

Anesthesia, Inhalation↗
PubMed2001

Reference values for lead and cadmium in blood of Czech population.

This study aimed at determining blood concentrations of lead (B-Pb) and cadmium (B-Cd) in a group of 1215 healthy blood donors (895 males, 320 females) and 758 children (397 boys, 361 girls) aged 10 years, sampled in 1996-1998 in four districts of the Czech Republic. The analysis was performed using atomic absorption spectrometry. The median B-Pb values were lower in children (34 mg/L) than in adults. In the group of adults, the level was significantly higher in men (46 mg/L) than in women (29 mg/L). In none of the groups the 90th percentile exceeded the value of 100 mg/L. The B-Cd values in adults depended on smoking habit (median non-smokers: 0.5 mg/L, male smokers--1.2 mg/L, female smokers--1.0 mg/L). In children, more than 50% of values were under the limit of detection. The obtained values were used to propose reference values for the Czech population.

Adult↗
PubMed2004

Home-based self-measurement of blood pressure: a proposal using new reference values (the PURAS study).

OBJECTIVES: To establish reference values for blood pressure by means of self-measurement of blood pressure (BP) conducted at home. DESIGN: Descriptive study of the distribution of self-measured BP at home and its correspondence with clinic-based measurements of BP. METHODS: The aim of this study is to define the home BP levels that correspond to clinic BP thresholds 140/90 mmHg (hypertension) and 130/85 mmHg (normality). The sample consisting of 1411 randomly selected adults stratified by age and gender. A pre-calibrated electronic device (Omron 705CP) was used for BP and heart rate (HR) measurements and a trained nurse performed clinic-based sphygmomanometer measurements. The same nurse provided tutorials for the subjects on how to obtain 12 self-measured BP values at home using the Omron device in a single day. RESULTS: Of the 1184 volunteers that attended the appointment, 195 were known as hypertensives and were excluded from the study. The average age of the remaining 989 subjects (50.4% females) was 44.3 years. Clinic BP values were significantly higher than self-measured BP at home regardless of age and gender. Both had good correlations (systolic BP, r=0.84 and diastolic BP, r=0.77). Using linear regression, the self-measured BP at home hypertension threshold would be 131/82 mmHg and the limit of normality 123/78 mmHg. Using corresponding percentiles, these values would be 134/85 and 124/80 mmHg, respectively. CONCLUSIONS: The self-measured BP at home values found in this study, when defining hypertension, are lower than values currently accepted (135/85 mmHg). Long-term studies are necessary to confirm these results.

Adult↗
PubMed1986

Hematology reference values for peripheral blood of laboratory rats.

Reference values for peripheral red and white blood cells, platelets and coagulation parameters from 11 and 18-week-old Charles River Sprague Dawley rats [Cr1:COBS CD(SD)] were obtained using automated methods. The Coulter Model S Senior, the Clay Adams Ultra-Flo Platelet Counter and the Sherwood Lancer Coagulyzer, were used to measure these parameters on 25 rats/sex. Detailed information on instrumentation or assay methods, and the animals, their source, environment and blood collection method was given. Platelet counts were in the range of 694 X 10(9)/1 to 1412 X 10(9)/1 which was higher than previously reported. In general, the remaining ranges were similar to previously published reference ranges.

Animals↗
PubMed1997

Reference values for extremity muscle strength obtained by hand-held dynamometry from adults aged 20 to 79 years.

OBJECTIVE AND DESIGN: Only a few studies have provided reference values for muscle strength obtained by hand-held dynamometry. Such values are essential for establishing the degree to which an individual's strength is impaired. This descriptive study was conducted to provide reference values for the strength of 10 extremity muscle actions. SUBJECTS AND INSTRUMENTATION: A convenience sample of 106 men and 125 women volunteers was tested twice with an Ametek digital hand-held dynamometer. RESULTS: The measurements were found to be reliable. Predictive equations are provided for the measurements. Reference values generated are expressed in Newtons and as a percentage of body weight and are organized by gender, decade of age, and side. CONCLUSIONS: The values can be employed in a clinical setting to document whether an individual is impaired relative to healthy subjects of the same gender and age.

Adult↗
PubMed1990

[Age dependence, sex independence and reference values of serum fructosamine determined using a new colorimetry method].

Reference ranges were evaluated for a new colorimetric method for the determination of fructosamine in serum. The reference group was composed of 1114 non-diabetics of both sexes including children. Reference values are only slightly affected by age and sex. In the course of childhood to adolescence fructosamine values raise and finally stabilize in adults. The small differences between both sexes have no effect on the interpretation of clinical results. Relating fructosamine values to albumin or total protein has little impact on the distribution of the values when protein values were within the reference range.

Adolescent↗
PubMed1992

Trace element reference values in tissues from inhabitants of the European Community. II. Examples of strategy adopted and trace element analysis of blood, lymph nodes and cerebrospinal fluid of Italian subjects.

The EURO TERVIHT (Trace Element Reference Values in Human Tissues), recently initiated, aims to establish and compare trace metal reference values in inhabitants from the different EC countries. The project anticipates international cooperation of specialized chemical and toxicological laboratories in Western Europe. In order to overcome the well known and intolerable high fluctuation in published trace metal concentrations in body fluids and tissues, which are mostly due to poor analysis, this paper gives recommendations and strategies for approaching 'background' values measurement practised in the EURO TERVIHT. The focus of the paper is more on quality rather than on quantity of data with particular aspects: (i) well-described protocol for the selection/composition of reference groups (extended epidemiological data plus clinical status); (ii) numerous pre-analytical factors, among which are of paramount importance are ultraclean laboratory air, container material, storage conditions at -20 degrees C; (iii) statistical treatment of the data and the expression of the analytical results (use of refined statistical analysis such as the Lilliefors test to define the type of distribution, normal or log-normal). Results reported here concern the determination of trace elements in whole blood of more than 350 Italian subjects which allowed the proposal of 'reference values' for 12 elements. In lymph nodes and cerebrospinal (CSF) the degree of information acquired is only sufficient to suggest 'indicative' of 'informative' values.

Computers↗
PubMed1995

[Maximal static respiratory pressures. The importance of the study of normal reference values].

In order to determine the validity for our population of the theoretical reference values available in the literature today, we studied respiratory muscle force by calculating maximum expiratory pressure PEmax and maximum inspiratory pressure (PImax) in 100 healthy subjects in Asturias (50 women) between 17 and 80 years-old (mean 40.4 +/- 19.3 years). We used the same methods and apparatus as Black and Hyatt and compared the results with theoretical values given by them as references corresponding to our subjects, according to age and sex. Values were significantly lower (p < 0.001) in our population for both parameters and for both men and women. In men PEmax was 69.7% and PImax was 88.5% of the theoretical values, in women PEmax was 60.9% and PImax was 82.9%. These figures indicate that the theoretical values given by Black and Hyatt are not valid for the population we studied and that normal reference values appropriate for each population, laboratory and apparatus must be obtained if valid conclusions are to be reached.

Adolescent↗
PubMed1997

[Bronchoalveolar lavage in childhood: technical aspects and reference values].

(BAL) has been increasingly used in recent years also in children. In paediatric pulmonary diseases, however, interpretation has proved difficult in the absence of standard reference values for BAL in childhood. It is the purpose of the present publication to discuss the methodological aspects of BAL in childhood and to proviced criteria by means of standard reference values for the assessment of BAL in paediatric patients. In a group of 50 children aged 3 to 15 years with healthy lungs, who were subjected to BAL during an elective surgical intervention, we examined both cellular and non-cellular components of the BAL. Whereas the percentage of macrophages and lymphocytes in the total population did not differ significantly from the standard values in adults, the absolute and relative granulocyte count was found to be elevated in children under 8 years of age. The CD4/CD8 quotient of BAL was 0.7 on the average, and hence clearly below the standard reference values defined for adults. In the non-cellular components we found an increase in the level of all proteins from plasma, whereas locally produced proteins did not differ from the findings in healthy adults. The total phospholipid content of BAL was markedly enhanced in children below 8 years of age and decreased with increasing age. These differences between children and adults should be taken into account when interpreting pathological findings. They are the basis for better defining the ranking of BAL in paediatric pulmonary diseases.

Adolescent↗
PubMed2005

Reference values for diagnostic radiology: application and impact.

Reference values (RVs) are recommended by the American Association of Physicists in Medicine for four radiographic projections, computed tomography, fluoroscopy, and dental radiography. RVs are used to compare radiation doses from individual pieces of radiographic equipment with doses from similar equipment assessed in national surveys. RVs recommended by the American Association of Physicists in Medicine have been developed from the Nationwide Evaluation of X-ray Trends survey performed by the state radiation protection agencies with the cooperation and support of the U.S. Food and Drug Administration, the Conference of Radiation Control Program Directors, and the American College of Radiology. The RVs selected by the American Association of Physicists in Medicine represent, approximately, the 80th percentile of the survey distributions. Consequently, equipment exceeding the RVs is using higher radiation doses than is 80% of the equipment in the surveys. Radiation doses for specific projections, with standard phantoms, should be measured annually, as recommended by the American College of Radiology. When the RVs are exceeded, the medical physicist should investigate the cause and determine, in cooperation with the responsible radiologist, whether these doses are justified or the imaging system should be optimized to reduce patient radiation doses. RVs are a useful tool for comparing patient radiation doses at institutions throughout the United States and for providing information about radiographic equipment performance.

Equipment Safety↗
PubMed2006

[Normal reference values of the pulsatility index and peak systolic velocity in the fetal middle cerebral artery during normal pregnancy].

OBJECTIVE: To establish the normal reference values of the fetal middle cerebral artery (MCA) pulsatility index (PI) and MCA peak systolic velocity (PSV) during normal pregnancy. PARTICIPANTS AND METHODS: A total of 727 normally grown fetuses were evaluated with pulsed Doppler ultrasound between 20 and 40 weeks of gestation. The MCA was located in a transverse view of the fetal head 1 cm after its origin from the Willis vascular circle. The insonation angle was always kept as close as possible to 0. The PI and PSV were measured in 5 consecutive and uniform cardiac cycles and the mean considered as the representative for each case. Normal reference values for each gestational week were constructed. Reproducibility and agreement were analyzed for the MCA PI estimation. RESULTS: There was a significant correlation between MCA PSV and gestational age (GA) (PSV = -13.81+1.96 X GA, r2 = 0.59, p=0.001). The correlation between MCA PI and GA showed an initial increment until week 30 with a further reduction towards the end of the pregnancy (MCA PI = 2.44 + -0.02 X EG, r2 = 0.09). Reproducibility analysis of the MCA PI estimation showed an intra-class and inter-class correlation coefficients of 0.89 (95%CI 0.65-0.97) and 0.87 (95% CI 0.63-0.93), respectively. Agreement evaluation showed a mean difference between observers of 0.03 (standard deviation 0.19), with 95% limits of agreement of -0.41 a 0.35. CONCLUSION: The normal reference values obtained in this study confirm the diagnostic and prognostic capacity of the fetal MCA PI and the MCA PSV evaluation in high risk pregnancies.

Adolescent↗
PubMed1993

Reference values for Doppler velocimetric indices from the fetal and placental ends of the umbilical artery during normal pregnancy.

A range-gated Doppler ultrasound system combined with a real-time imaging system was used to determine arterial blood velocity values from the fetal and placental ends of the umbilical cord in 269 normal pregnancies between 17 and 40 weeks, menstrual age. The systolic-diastolic ratio (S/D), pulsatility index (PI), and resistance index (RI) were higher at the fetal end compared to the placental end of the cord. The individual differences in these Doppler indices, obtained between the fetal and placental recording sites, were inversely related to menstrual age: S/D: r = -0.38, p < 0.001; PI: r = -0.25, p < 0.001; and RI: r = -0.15, p < 0.01. After normalization for the angle of insonation, the peak systolic velocity was higher and the end-diastolic velocity was lower at the fetal than at the placental end of the cord. It is concluded that routine recordings for Doppler velocimetric indices should take into account the recording site on the umbilical cord in order to reduce methodological sources of variance, especially during midgestation. Furthermore, the data presented here in the form of the median and percentile values are proposed as normal reference values to facilitate this procedure.

Blood Flow Velocity↗
PubMed1981

[Reference values for 2 well-defined populations: newborn infants and post-partum women].

Reference values for two well defined populations, four day old newborns and post-partum women, are given for 19 parameters measured on a SMAC system. These values are respectively compared to those established previously for children from one to three year old and those of women aged 20-39. The values for the new borns are higher for eight parameters and lower for nine others. The values for post-partum women are higher for seven parameters and lower for six others. These two groups have therefore distinct reference values for most of the parameters studied.

Adult↗
PubMedDate not supplied

[First SIVR list of reference values: definitions, methodologic criteria and analytical strategies].

In this paper, a list of reference values for trace elements and some of the main organic xenobiotics and/or their metabolites in biological matrices (urine, serum or blood) is presented. This list has been made out taking into account several variables, such as sex, diet, alcohol and drugs consumption, smoking habits, living area, etc. and it is referred to as the 1st SIVR list 2001. In addition, the SIVR research activity is reassessed on the basis of the availability of multielement techniques and new analytical approaches. In particular, to define the reference values for PCB, selection criteria and analytical methodologies are discussed with a view to choosing the more significant congeners and the most suitable technique. In the end, the results from two SIVR projects concerning the determination of haematic Pb and urinary Hg are synthesized.

Chemistry, Clinical↗
PubMedDate not supplied

Liver and kidney function tests in normal and pre-eclamptic gestation--a comparison with non-gestational reference values.

OBJECTIVE: To compare liver and kidney function tests in pre-eclampsia and in uncomplicated pregnancy and to relate the results to physiological reference values. DESIGN: Prospective cross sectional study. SETTING: Antenatal clinic and antenatal labour wards, Harare Hospital, Zimbabwe. SUBJECTS: 38 pre-eclamptic and 72 normal women of similar parity, gravida and gestational age. MAIN OUTCOME MEASURES: Serum albumin, total bilirubin, alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT) and gamma-glutamyl transaminase (GGT) were used as indices of hepatic function. Serum creatinine, urea and uric acid were used to assess renal function. RESULTS: Albumin, bilirubin and ALT did not show any differences between the pre-eclamptic and normotensive pregnant women. The activities of the following enzymes, ALP (p < 0.001), AST (p = 0.001) and GGT (p < 0.01) were significantly elevated in pre-eclamptic women. The renal indices, creatinine, urea and uric acid were significantly raised in pre-eclampsia (p < 0.001). No significant differences were observed in the haematological parameters, haemoglobin (Hb), white blood cell count (WBC), red blood cell count (RBC), mean corpuscular volume (MCV) and platelet count. Almost all the biochemical and haematological parameters were lower in normal pregnancy compared to the physiological reference values used in our maternity unit. CONCLUSION: Liver and kidney function is modified by normal pregnancy. However, the majority of the liver and kidney function tests between pre-eclamptic and normal pregnancy exhibited significant differences. The physiological reference values that are currently in use are different from those of women with uncomplicated pregnancies and may not be entirely suitable for management of pre-eclampsia which has hepatic and renal involvement.

Adolescent↗
PubMed2006

Cystatin C reference values and aging.

OBJECTIVES: The aim of this study was to determine the reference values for serum cystatin C (CysC) with a particular focus on the effect of aging. DESIGN AND METHODS: The study was performed on a consecutive series of subjects (258 men and 396 women). Laboratory parameters and a detailed personal and family medical history were collected. RESULTS: CysC showed a significant correlation with age in both sexes, which was confirmed with multivariate linear regression after adjustment for SCr (serum creatinine). Age-related reference intervals were established for cystatin C (<45 years, <0.95 mg/L and >45 years, <1.20 mg/L). CONCLUSIONS: The use of CysC reference values adjusted for age should be carefully taken into consideration.

Adult↗