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 1,387 records · Page 77Linked to original sources

PubMed2001

Metacarpal index by digital X-ray radiogrammetry: normative reference values and comparison with dual X-ray absorptiometry.

Metacarpal index (MCI), the combined cortical midmetacarpal thickness divided by the outer mid-metacarpal diameter, fell into oblivion when dual photon absorptiometry was introduced a quarter of a century ago. Modern PC-based digital X-ray diameter measurements offers a unique opportunity for precise and accurate measurements of MCI (DXR-MCI). We hypothesized that DXR-MCI in contrast to projected areal bone mineral density (BMD) (DXA-BMD) is independent of bone size and studied 384 normal women by measuring DXR-MCI and DXA-BMD of the lumbar spine, hip, and distal radius. A normative MCI database for women is presented. It has its maximum in the third decade, and a moderate biologic variation that seems to decline with age. It was found that DXR-MCI was independent of body weight and body surface area, whereas all DXA-BMD values were significantly dependent on them. Body height was significantly correlated with DXA-BMD at all sites, but less so with DXR-MCI. The latter was correlated with metacarpal bone length. It is suggested that the moderate correlation between MCI and body height would be abolished if the region of interest used for calculation of MCI be adjusted according to individual metacarpal bone length. DXR-MCI correlated significantly with DXA-BMD at the sites measured, and particularly well with that of the distal radius (r = 0.67; p < 0.0001).

Absorptiometry, Photon↗

PubMed1986

Ventilatory function in normal Saudi Arabian adults. Observations and comparison with some Western and Eastern reference values.

Ventilatory function was studied in healthy non-smoking Saudi Arabian adult males from Riyadh area, and findings compared with those of some Western and Eastern populations. It was found that while the FVC and FEV1 in our subjects were lower than in American, Canadian, Jordanian, and Hongkong Chinese, these were higher than in Indian and Singapore Chinese. Most parameters of expiratory flowrate (e.g. PEF, MEF75, MEF50), however, were equal to or higher in our subjects than in American, Canadian, and Jordanian, as well as Indian and Chinese subjects. Compared to the findings in normal subjects from Jeddah, Saudi Arabia, FVC was equal to, but FEV1 and FEF 25-75 were higher in our subjects.

Adolescent↗

PubMed2003

Whole blood viscosity, plasma viscosity and erythrocyte aggregation in nine mammalian species: reference values and comparison of data.

In this study species-specific values for whole blood viscosity (WBV), plasma viscosity (PV) and erythrocyte aggregation (EA) were determined in a total of 360 animals. We used 40 individual adult animals of nine mammalian species: horse, pig, dog, cat, rat, cattle, sheep, rabbit and mouse. WBV measurements were carried out using a LS30 viscometer, PV was measured using OCR-D and EA was measured using a Myrenne aggregometer and the LS30 (aggregation index at low shear rate). At low shear rates (0.7 s(-1) and 2.4 s(-1)) haematocrit (Hct)-standardized (40 % Hct) samples showed a higher value of WBV and EA in horse, pig, dog and cat. In cattle, sheep, rabbit and mouse, EA and WBV were markedly decreased and EA was almost undetectable, although the plasma fibrinogen concentration was higher in these animals. Rats showed the highest WBV at low shear rate in native blood and WBV was not different from horse in Hct-standardized blood; however, EA was very low in the rat, a result that might be explained by mechanical or geometrical properties of the red blood cell. EA correlated with the plasma protein concentration in each species except dog and mouse. In horse, cattle and pig, EA correlated with the plasma fibrinogen concentration. At high shear rate (94 s(-1)), WBV was higher in cattle than cat and rat, and dog had higher values than horse, suggesting specific interspecies differences depending on low shear and high shear values of WBV, as a result of mechanisms that influence RBC flexibility. PV was highest in cattle and lowest in rabbit and mouse and did not correlate with WBV. Haemorheological parameters differed between the species. Each species has its own rheological fingerprint. The physiological significance of these variations among mammalian species has not yet been established. Viscosity contributes to endothelial cell shear stress. While haemorheological parameters differ across the species it may be postulated that factors influencing flow-mediated endothelial cell signal transduction are different among the species.

Animals↗

PubMedDate not supplied

[Asbestos fibres and reference values].

Biological RV for asbestos implies several problems, due to the difficult interpretation of values obtained from various biological samples (sputum, BALF, lung tissue). Therefore, it seems it advisable to refer to environmental concentrations (ERC), which are not avoidable, since asbestos is an ubiquitous contaminant. On the basis of the available studies the 1 f/L value is usually reported as the most representative, although more recent and reliable studies would indicate lower values, at least for outdoor concentrations, as determined by SEM. However, further studies are needed: standardized methods based on SEM (author's opinion) should be adopted; the accuracy of such technique is sufficient for air concentrations from 0.05-0.1 f L-1 upwards, with the advantage of lower costs and time as compared to TEM.

Asbestos↗

PubMed1984

Reference values for elemental concentrations in some human samples of clinical interest: a preliminary evaluation.

Over 60 investigators, some of them with an outstanding international reputation as analysts, were requested to identify reliable data from their countries for elemental concentrations in normal adult human samples of clinical interest by contributing their own data as well as screening the literature information. A set of samples consisting of whole blood and its components, urine, milk, liver and hair were chosen and considered for 15 elements of biological significance: Zn, Cu, Fe, Se, Mn, Pb, Cd, Hg, As, Mo, Cr, Co, I, Ni and F. The results partly cover over 40 countries from the global regions of Africa, Asia, Europe, North, South and Central America, Australia and New Zealand. This survey has been useful in demonstrating certain trends of trace element picture around the world, at least qualitatively. Both diet and environment have a strong influence on the distribution pattern of several elements such as As, Cd, Mn, Pb, Se and Zn. A limited comparison of the available information on soil status of different countries revealed interesting associations for elements such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to supply a reasonable amount of data on samples requested here. In particular, for a number of countries, reliable data for even very essential elements such as Cu, Zn and Fe were not available. In view of the nutritional importance of several elements the time is ripe for international organizations to intervene and help produce some reference data for selected global regions which lack data of any kind.

Diet↗

PubMed1988

Lung volume reference values for blue collar workers not exposed to occupational respiratory hazards.

Epidemiologic research into occupationally related lung disease often requires the comparison of a study group with an external nonexposed comparison group. In order to develop such an external comparison group, blue collar workers, who had no obvious adverse occupational pulmonary exposure, performed simple spirometry, were administered a standard questionnaire, and had standard posterior-anterior and lateral chest radiographs taken. Prediction equations were established for three indices of lung volume, namely total lung capacity, residual volume, and their ratio, for various combinations of race, sex, and smoking groups. Asymptomatic non-smokers with normal radiograph results were then extracted from the overall group, and separate prediction equations were established. The relationship between age and total lung capacity is discussed.

Adult↗

PubMed1999

Profiling steroid hormones in amniotic fluid of midpregnancy by routine stable isotope dilution/gas chromatography-mass spectrometry: reference values and concentrations in fetuses at risk for 21-hydroxylase deficiency.

Using routine stable isotope dilution/gas chromatography-mass spectrometry, 17-hydroxyprogesterone, androstenedione, testosterone, dehydroepiandrosterone, androstanediol, and 5alpha-dihydrotestosterone have been profiled in amniotic fluid of midgestation in 77 normal fetuses and 38 untreated or dexamethasone-treated fetuses at risk for 21-hydroxylase deficiency. Dexamethasone was suspended 5-7 days before amniocentesis. In normal fetuses, amniotic fluid concentrations (median, range; nanograms per mL) of 17-hydroxyprogesterone did not reveal a sex difference (1.48, 0.21-4.96), whereas those of androstenedione were lower in females (0.53, 0.00-2.71) than in males (0.93, 0.29-1.98). Testosterone levels were higher in males (0.24, 0.00-0.50) than in females (0.00, 0.00-0.27). No sex difference was found for dehydroepiandrosterone (0.47, 0.19-1.77). Levels of androstanediol and 5alpha-dihydrotestosterone were below the detection limit of our method in most cases. Regarding prenatal diagnosis of 21-hydroxylase deficiency, 17-hydroxyprogesterone and androstenedione presented the diagnostically most valuable steroids and were of equal diagnostic potential. They permitted successful diagnosis in 36 of 37 fetuses at risk: 12 were untreated and unaffected, 13 were treated and unaffected, 4 were untreated and affected (3 salt wasters and 1 simple virilizer), and 8 were treated and affected (5 salt wasters and 3 simple virilizers). In the latter group, one simple virilizer revealed normal steroid concentrations. Isotope dilution/gas chromatography-mass spectrometry, providing the highest specificity in steroid analysis, is proposed for routine use in clinical steroid analysis whenever maximal reliability is requested. Our study provides the first mass spectrometric reference data on amniotic fluid steroid concentrations and underscores the high accuracy of prenatal hormonal diagnosis of 21-hydroxylase deficiency.

Adrenal Hyperplasia, Congenital↗

PubMed1984

[Age-related reference values for serum triacylglycerol subfractions].

In connection with the increased importance of serum triacylglycerols (TAG) in atherogenesis and with a view to their eventual changes wth age, their subfractions were studied in practically healthy subjects via thin-layer chromatography. Comparative assessments for "norm" of TAG-subfractions are elaborated according to saturation rate, depending on age, and sex. No regular sex differences were established in the rest age groups. With age advancing reduction of S3 was established for both sexes, of MD2--for females and M3--for males and increase of M2 in females and D2 in males. In quantitative respect, for both sexes, most frequent are MD and M2, followed by S2M and SD2. The saturated fatty acids predominate at 1 and 3 positions of TAG in practically healthy subjects and at 2 position--unsaturated fatty acids.

Adolescent↗

PubMed1981

Reference values and analytical performance of the hydroxyproline/creatinine ratio in early morning urine samples.

The hydroxyproline/creatinine ratio for two groups of healthy individuals and two groups of patients with a history of mammary and prostatic carcinoma without metastases was measured and compared with literature values. The hydroxyproline/creatinine ratio for healthy adults appears to be 1.4 (range 0.7--2.3). Furthermore, the influence of diet and gelatin load of 30 g on the hydroxyproline creatinine ratio and the hydroxyproline excretion has been investigated. The analytical characteristics of the test used in the present study were evaluated using the method of standard additions. An intra-assay quality-control on the basis of the standard addition is proposed. The coefficient of variation of the hydroxyproline/creatinine ratio appears to be 22%. The intraindividual variability has also been established for the hydroxyproline/creatinine ratio and appears to be 25%.

Adult↗

PubMed1980

[The different ways of expressing the results of the monoxide test in steady state: discussion and proposition of reference values for epidemiological studies (author's transl)].

The results of the steady state carbon monoxide test can be expressed quantitatively as the amount of CO absorbed by the lung per minute and per 1 mm Hg pressure difference (TCO; ml/min/mm Hg) or as the ratios between partial pressures of CO (FICO, FECO, FACO), fractional untake coefficient (Formula: see text), From measurements taken in 141 non-smokers (mean age 47.43 +/- 6.4 years), 60 ex smokers (mean age 45.73 +/- 5.29 years) and 322 smokers (mean age 46.65 +/- 5.5 years), TCO and fractional uptakes were calculated and discussed. Considering the fact that mean TCO had a larger standard deviation that mean FUCO and that TCO had a non-Gaussian distribution, the authors chose to express the results of the test in fractional uptakes. Equations are proposed to calculated fractional uptakes.

Adult↗

PubMed2006

Reference values for the five-repetition sit-to-stand test: a descriptive meta-analysis of data from elders.

This meta-analysis was conducted to generate normative values for the 5-repetition sit-to-stand (STS) test suitable for application to individuals at least 60 years of age. A thorough review of the literature yielded 13 papers (14 studies) relevant to this purpose. After the exclusion of potentially unrepresentative data, meta-analysis of these 13 papers indicated that judgments about normal performance should be based on age. Analysis demonstrated that individuals with times for 5 repetitions of this test exceeding the following can be considered to have worse than average performance: 11.4 sec (60 to 69 years), 12.6 sec. (70 to 79 years), and 14.8 sec. (80 to 89 years).

Aged↗

PubMed1993

Haematological reference values for east African wild ungulates.

Basic haematological values were obtained in the field from shot, clinically normal, wild East African ungulates. The species studied were: Thomson's gazelle (Gazella thomsonii), Grant's gazelle (Gazella grantii), blue wildebeest (Conochaetes taurinus), Coke's hartebeest (Alcelaphus buselaphus cokii), impala (Aepyceros melampus) and Burchell's zebra (Equus burchelli). Red cell parameters compared well with previous reports although the mean cell haemoglobin concentrations were higher. The white cell counts were considerably lower in all species. The red and white cells of all species studied had standard mammalian morphology. Generally, the field equipment used worked well under the conditions encountered, although the field microscope made cell counting troublesome and the heat made the preservation of fixed slides difficult.

Africa, Eastern↗

PubMed1992

Tentative reference values for some elements in broncho-alveolar lavage fluid.

The concentrations of Fe, Mn, Pb and Cr have been determined in broncho-alveolar lavage (BAL) fluid of 25 subjects without occupational or abnormal environmental exposure to metals, using the AAS method. The numerous factors which can interfere with the results in pre-analytical and in analytical phases are stressed. Metals concentrations in BAL are expressed in micrograms/l. They were not correlated with the volume of fluid recovered, the total cells, alveolar macrophages and erythrocytes. The results were not modified by stratification considering age and sex. Iron concentrations were higher than others, probably due to higher environmental exposure and partly to its essential role in humans. The diagnostic significance of element determination in BAL fluid and the relationship with exposure and lung load is discussed.

Bronchoalveolar Lavage Fluid↗

PubMed2002

Serum KL-6 levels in pediatric patients: reference values for children and levels in pneumonia, asthma, and measles patients.

Serum KL-6 reflects alveolar damage and regeneration of type II pneumocytes, indicating disease activity in various interstitial lung diseases. We conducted a descriptive and observational multiple case-control study to determine the distribution of serum KL-6 levels in pediatric patients with or without respiratory diseases. Subjects were recruited from the patients of a teaching hospital in the suburb of Tokyo. A consecutive series of 401 children (0-16 years old) underwent blood sampling for many clinical reasons. They comprised the following four groups: pneumonia (n = 96), bronchial asthma (n = 101), measles (n = 102), and nonrespiratory diseases (n = 102) as a control group. Standard upper limits of serum KL-6 in a group of children with nonrespiratory disease were 250 U/mL, or half the adult level. No gender or age differences were observed. Elevated serum KL-6 concentrations were observed in severe pneumonia, acute exacerbations of asthma, and measles pneumonia. In the measles group, KL-6 values reflected the presence and severity of complicating pneumonia. We conclude that serum KL-6 levels exceeding 250 U/mL were rarely observed in children without respiratory diseases. In contrast, a substantial proportion of children with common respiratory diseases showed mild to moderate increases in serum KL-6 levels. Elevated serum KL-6 in these children may reflect the presence of alveolar damage, followed by regeneration of type II pneumocytes. However, in order to use serum KL-6 as a marker of interstitial lung diseases in children, a cutoff level should be determined separately.

Adolescent↗

PubMed2006

Reference values for Leishmania infantum parasitemia in different clinical presentations: quantitative polymerase chain reaction for therapeutic monitoring and patient follow-up.

Quantification of Leishmania infantum DNA in blood samples by an ultrasensitive quantitative polymerase chain reaction (QPCR) detected parasitemias in different clinical presentations. We observed a large range of parasitemias, more than 9 log values, and could determine the threshold between asymptomatic carriage and disease in the Mediterranean area (approximately one parasite/mL of blood). Based on kinetoplast DNA amplification, this assay had a sensitivity of 0.001 parasite DNA equivalents/mL and detected asymptomatic carriage of Leishmania. It detected parasite DNA in 58% of healthy subjects, while an immunoblot detected specific antibodies in only 16%. For initial diagnosis of disease, this quantitative PCR with blood samples constitutes a non-invasive alternative to bone marrow aspiration. Its main applications are monitoring of drug therapy and follow-up of immunodeficient patients for biologic confirmation of relapses.

Amphotericin B↗

PubMed1993

Reference values for blood toluene in the occupationally nonexposed general population.

Blood toluene was measured by gas chromatography--mass spectrometry in 232 occupationally nonexposed subjects, consisting of 126 rural and 106 urban workers, and 37 chemical workers. Mean blood toluene was significantly lower in rural (698 ng/l) and urban workers (984 ng/l) than in chemical workers (2789 ng/l). Blood toluene was not significantly different between the rural and urban workers or among the urban workers with different jobs. Smokers had significantly higher levels (median 606 ng/l) than nonsmokers (median 424 ng/l). Subjects who had smoked at least one cigarette in the last 2 h before blood sampling had significantly higher blood toluene (median 1170 ng/l) than those who had not smoked during this time (median 693 ng/l), for whom the level was not significantly different from that in nonsmokers. Blood toluene in the total population was less than 2863 ng/l in 95% cases.

Adult↗

PubMed1995

Spirometric reference values for white European children and adolescents: Polgar revisited.

We analyzed six spirometric data sets collected in the Netherlands, Austria, the United Kingdom, Spain, and Italy. The objectives were to establish whether (1) it was possible to describe spirometric indices from childhood to adulthood, taking into account the adolescent growth spurt, and (2) there are systematic differences in ventilatory function between children and adolescents in different parts of Western Europe. The study comprised 2,269 girls and 3,592 boys, aged 6-21 years. The range in standing height was 110-185 in girls, 110-205 in boys. The model applicable to all data sets was ln FVC or ln FEV1 = a + (b + c x A) x H, where H = standing height and A = age; this model prevents the phase shift between the adolescent growth spurt in length and lung volume from leading to an age-dependent bias in predicted values. There was surprising agreement between most of the data sets; systematic differences are probably due to technical factors arising from ATPS-BTPS corrections and from defining the end of breath with pneumotachometer systems. Taking those into account, prediction equations for FVC, FEV1, and FEV1%FVC were developed with "lower limits of normal" which should be applicable to children and adolescents of European descent. It is proposed that the approach of analyzing available data sets should also be applied to other ventilatory indices, data collected in adults and elderly subjects, or in other ethnic groups, and that an international data base be set up to that end.

Adolescent↗

PubMedDate not supplied

The Perceived Stress Questionnaire (PSQ) reconsidered: validation and reference values from different clinical and healthy adult samples.

OBJECTIVE: The aim was to translate, revise, and standardize the Perceived Stress Questionnaire (PSQ) by Levenstein et al. (1993) in German. The instrument assesses subjectively experienced stress independent of a specific and objective occasion. METHODS: Exploratory factor analyses and a revision of the scale content were carried out on a sample of 650 subjects (Psychosomatic Medicine patients, women after delivery, women after miscarriage, and students). Confirmatory analyses and examination of structural stability across subgroups were carried out on a second sample of 1,808 subjects (psychosomatic, tinnitus, inflammatory bowel disease patients, pregnant women, healthy adults) using linear structural equation modeling and multisample analyses. External validation included immunological measures in women who had suffered a miscarriage. RESULTS: Four factors (worries, tension, joy, demands) emerged, with 5 items each, as compared with the 30 items of the original PSQ. The factor structure was confirmed on the second sample. Multisample analyses yielded a fair structural stability across groups. Reliability values were satisfactory. Findings suggest that three scales represent internal stress reactions, whereas the scale "demands" relates to perceived external stressors. Significant and meaningful differences between groups indicate differential validity. A higher degree of certain immunological imbalances after miscarriage (presumably linked to pregnancy loss) was found in those women who had a higher stress score. Sensitivity to change was demonstrated in two different treatment samples. CONCLUSION: We propose the revised PSQ as a valid and economic tool for stress research. The overall score permits comparison with results from earlier studies using the original instrument.

Abortion, Spontaneous↗