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PubMed1990

Reference values for the Mini-Mental State Examination (MMSE) in octo- and nonagenarians.

The Mini-Mental State Examination (MMSE) was used in a population survey of all inhabitants of Leiden, the Netherlands, over 85 years (n = 1258). In this paper we report on 532 subjects without neurological or psychiatric disease. Results show that the median score and lowest quartile cut-off score remain high until the tenth decade (median score = 28, lowest quartile cut-off score = 26). Thus age, in itself, is not a major limitation in using the MMSE. In this study a comparatively low level of education (the majority had 6 to 7 years of education) did not affect the results on the MMSE in a negative way, nor did we find an association with the use of psychoactive drugs.

Aged↗

PubMed2005

Comparative acute toxicity of organic pollutants and reference values for crustaceans. I. Branchiopoda, Copepoda and Ostracoda.

The acute toxicity of 468 organic pollutants to planktonic crustaceans (Branchiopoda, Copepoda and Ostracoda) from pre-existing data was compared by means of statistical analysis and relative tolerance indices (Trel). A surrogate species commonly used in toxicity bioassays (Daphnia magna) showed toxicity levels--within one order of magnitude--similar to all other Cladocera species, at least for 82% of the chemicals studied. All neurotoxic insecticides except neonicotinoids, PCBs, organometallic compounds and PAHs are the most toxic substances to these organisms. Sensitivity levels among taxa were compared for individual chemicals as well as groups of chemicals with similar characteristics. Whilst there are marked differences in sensitivity among taxa and particular groups of chemicals, no consistent trends were found for freshwater and saltwater species in relation to the latter groups. No correlation between LC50 and size of these organisms was found other than by chance, making extrapolations based on allometric equations impossible.

Animals↗

PubMed1988

Aspects on reference values for tumor markers in human prostatic carcinoma.

The efficiency of the tumor markers prostatic acid phosphatase (PAP), prostate-specific antigen (PSA), neopterin, and osteocalcin was tested with regard to their ability to predict cancer death within 2 years plus survival beyond 2 years in a series of patients with newly diagnosed prostate cancer. For all markers, an elevated level suggested a tumor with a worse prognosis. Moreover, the extent to which the level was increased carried additional information. The prognostic efficiency was routinely improved by selecting cutoff levels higher than the standards suggested by the radioimmunoassay (RIA) kit manufacturers. Seventy-four percent of the patients with elevated levels of neopterin were still alive after 2 years when 8 nmol/L was selected as the upper normal value compared to only 43% at 12 nmol/L. At a cut-off value of 3 micrograms/L for osteocalcin, 79% of the patients with elevated levels were still alive after 2 years compared with only 20% when 7 micrograms/L was selected. Such adjustments to higher cutoff levels could be made without increasing the number of "false-negatives." The efficiency of PAP to predict short-term prognosis was poor at the standard cutoff level of 1.9 microgram/L. Not until 20 micrograms/L was selected did the efficiency exceed 80%. PSA was highly sensitive but little specific at any of the cutoff levels tested with regard to ability to indicate prognosis.

1-Carboxyglutamic Acid↗

PubMed1993

Electromyographic activity of human masticatory muscles in normal young people. Statistical evaluation of reference values for clinical applications.

Electromyographic activity of anterior temporal and masseter muscles was measured in 92 young healthy men and women with sound dentitions during rest position, contact in centric occlusion and clench. Male and female mean potentials were similar except in clench, where males had higher electromyographic levels. Mean pooled electromyographic potentials were 1.9 microV (TA) and 1.4 microV (MM) during rest position, 6.5 microV (TA) and 2.8 microV (MM) during contact in centric occlusion. Mean maximum voluntary clench potentials were 181.9 microV (TA) and 216.2 microV (MM) in men, 161.7 microV (TA) and 156.8 microV (MM) in women. Examined muscles were more asymmetric at low electromyographic activity (rest and centric occlusion) with the temporal muscle less asymmetrical than the masseter. In females temporal muscle activity tended to dominate at every contraction level, while in males masseter activity was stronger in clench, and temporal activity in centric occlusion and in rest position.

Adult↗

PubMed2004

Reference values for cardiac troponins T and I in healthy neonates.

OBJECTIVES: Cardiac troponins T (cTnT) and I (cTnI) are the most sensitive biochemical parameters in the detection of myocardial damage. In neonates, in utero exposure to tocolytic therapy results in detectable values of cardiac troponins after delivery. Additionally, some preliminary results suggest that the upper reference limits for healthy newborns are higher than those for adults but definitive reference limits for newborns are not available. Our objective was to determine those limits. DESIGN AND METHODS: In this study we investigated the distribution of cTnT and cTnI in cord blood of 869 healthy newborns. cTnT was determined with the 3rd generation assay and cTnI with the Dade Behring assay on a Dimension RxL. For data analysis Student's t test and the Mann-Whitney U test were used. RESULTS: Using the 99th percentile, the upper reference limit in healthy termed newborns was 0.097 microg/l for cTnT and 0.183 microg/l for cTnI. Compared to the adult values, the newborn upper limit was tripled for cTnT and doubled for cTnI. Statistically significant differences were found between males and females for cTnT and between natural childbirth and caesarean section for cTnI. CONCLUSION: Healthy-termed newborns have a higher upper reference limit for both cTnT and cTnI compared to adults. This circumstance must be taken into account when interpreting slightly "elevated" cTnT and cTnI values in newborns.

Adult↗

PubMed1999

Differences in cephalometric reference values between five centres: relevance to the Eurocleft Study.

Cephalometric data from five different geographical areas (Oslo, Manchester, London, Nijmegen, and Michigan) were compared. The angles SNA, SNB, and ANB were taken from published tables in the form of mean, standard deviation (SD) and number in the sample, divided up by age and sex. Angles SNA and SNB were significantly different among centres on univariate analysis. The Oslo data showed 23 instances in which they differed significantly from the other data, London 16, Manchester 11, Nijmegen 11, and Michigan 7. Multivariate analysis using Penrose distances were Oslo (2.04), Manchester (1.39), London (0.93), Nijmegen (0.80), and Michigan (0.66). The sums of the Mahalanobis distances were Nijmegen (3.60), Oslo (3.10), London (2.80), Manchester (2.25), and Michigan (1.49). As these results probably reflect racial and genetic differences, these must be taken into account when international comparisons are being made, as in the Eurocleft study.

Age Factors↗

PubMed1985

Serum total and high-density lipoprotein cholesterol--reference values obtained in the Coronary Risk Factor Study baseline survey.

Serum total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, and HDL/TC ratios have been established in 7 188 males and females aged 15-64 years who participated in the 1979 Coronary Risk Factor Study (CORIS) baseline survey in the southwestern Cape. TC levels in a sample of 575 1- and 2-year-olds were also determined. TC levels were found to be considerably higher at all ages than corresponding values found in recent surveys in the USA. By fitting epidemiological values associated with a low risk of coronary heart disease (CHD) to the CORIS data, cut-off points (CPs) for 'desirable' TC and HDL levels and HDL/TC ratios were obtained. The CPs for TC are considerably lower than those commonly used by pathology laboratories, and their adoption would result in a greater proportion of the 'westernized' population being regarded as being at risk of CHD, and therefore as requiring diet modification or drug treatment. Experience with the diagnosis of familial hypercholesterolaemia (FH) suggests that the CORIS 80th percentile for TC will correctly identify over 90% of cases of FH. On the basis of this, TC CPs for population screening for FH are also presented.

Adolescent↗

PubMed1987

[Evaluation of the delayed hypersensitivity response by the Multitest-IMC. Multicenter study for the definition of reference values in a sample population].

The latest investigations in the field of clinical immunology have proposed ways of assessing immunological efficiency that have also been used to identify patients most susceptible to infectious complications. The assessment of delayed hypersensitivity response (DHR) using anamnestic antigens is currently the most common method. The results of a polycentric study are presented. The study was conducted on a group of healthy subjects from various Italian regions divided into three age classes. Positive responses to the MT were noted in 96.4% of the population studied. The incidence of energy was statistically higher among females than males, while the mean response to the MT expressed in millimetres was statistically higher in males. Though 7 antigens were administered, the responsive population reacted on average to 3. The highest incidence of positive responses was to Candida, with Trichophyton responsible for the fewest.

Adolescent↗

PubMed1980

Reference values for functional residual capacity and maximal expiratory flow in young children.

To determine the relation of functional residual capacity and maximal expiratory flow at functional residual capacity to sex, age, height, and weight in healthy young children living in Portland, Oregon, we tested 37 boys and 36 girls using a modified helium-dilution technique and partial expiratory flow-volume curves. Within the age, height, and weight ranges studied, exponential or multiple regression techniques offered no substantial advantage over simple linear regression using height, weight, or age. There were no sex differences for the relationship between either variable and age, height, or weight. These techniques can readily be used in children as young as 3 years of age and may provide a method for studying lung growth and development in early childhood and a way to observe the progression of disease or the effect of treatment in the young child.

Body Height↗

PubMed1995

[Sources of error in measuring reference values].

For the solution of many problems it is essential to separate the reaction to a stimulus from the spontaneous circadian rhythm of the variable. But disturbing masking effects evoked by the actual activity level and after effects of earlier activities (masking effects) may obstruct such separations. Several protocols have been already described to reduce masking effects. They differ mainly in the quantity of the standardized activity. Those, which try to avoid masking due to sleep, have to use higher levels of activity to keep the subjects awake. Experimental comparisons of masking effects due to activity and due to sleep as well as to sleep deficits clarify that sleep is a less potent masking agent as often expected and may be allowed in routines designed to reduce masking effects. Masking effects due to sleep deficits and moderate activities are commonly underestimated and should be avoided as far as possible in such routines. Besides the circadian changes of reagibility, the extent of masking effects (even on body temperature) questions the usage of baseline measurements. Sleep can be investigated under reduced masking effects.

Bias↗

PubMed1989

Improved method for calculating calcium fractions in plasma: reference values and effect of menopause.

Multiple linear regression analysis showed that total calcium was significantly and positively related to albumin, globulin, anion gap, and bicarbonate in plasma from 556 normal postmenopausal women. The residual constant of 1.21 mmol/L approximated the normal mean for ionized calcium in plasma. The coefficients derived from the multiple regression analysis were used to calculate ionized calcium from total calcium and ligand concentrations in a series of 105 clinical cases in whom ionized calcium was measured with the calcium electrode. The regression equation was y = 1.00x -0.0039 mmol/L, where x is measured and y calculated Ca2+ (r = 0.78, P less than 0.001). The protein-bound, ultrafiltrable, and complexed fractions of the calcium were also calculated for plasma from 69 normal young men, 66 normal young women, and 305 normal postmenopausal women. The increased plasma calcium in the postmenopausal group was accounted for by an increase in the complexed fraction, due to increases in plasma bicarbonate and anion gap.

Adult↗

PubMed1994

Quantifying regional cerebral blood flow with N-isopropyl-p[123I]iodoamphetamine by ring-type single-photon emission computed tomography: validity of a method to estimate early reference value by means of regional brain time-activity curve.

A more accurate quantitative method for the measurement of regional cerebral blood flow (rCBF) with the microsphere model and N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) and ring-type single-photon emission computed tomography (SPECT) was developed. Continuous withdrawal of arterial blood was carried out for 5 minutes after the injection. Static SPECT data were acquired from 25 min to 55 min. To estimate reconstructed images at 5 min, total brain count collections and one minute SPECT studies were performed at 5, 20, and 60 min. Quantitative values for rCBF were calculated from short time SPECT images at 5 min (rCBF), static SPECT images corrected by total brain counts (rCBFCt) and those corrected by reconstructed counts on short time SPECT images (rCBFCb). Practically, rCBFCb is calculated by using reconstructed counts of regions of interest placed in the same position as static SPECT and short time SPECT at 5, 20, 60 min. Although there was good correlation between rCBF and rCBFCt (r = 0.69), rCBFCt tended to be underestimated in high flow areas and overestimated in low flow areas. A better correlation was observed between rCBF and rCBFCb (r = 0.92). The overestimation and underestimation observed in rCBFCt was considered to be due to the correction method with a total cerebral time activity curve, because the kinetic behavior of 123I-IMP was different in each region.

Amphetamines↗

PubMed1996

Reference values of urinary ethylenethiourea in four regions of Italy (multicentric study).

The results of a study in which urinary ethylenethiourea (ETU) was assayed in the general population (167 subjects) of four Regions of Italy (Veneto, Lombardy, Piedmont and Trentino Alto Adige) are reported. The results are compared with those in a population of 97 subjects from Rovescala, a hillside wine-producing town a few kilometers from Pavia, where ethylenebisdithiocarbamates are sprayed by helicopter. It was found that an average of 24% of the populations of the four regions, taken together, had urinary ETU levels above detection limits (1.0 microgram 1(-1)) as compared to 37% of the population of Rovescala. The ranges of concentration were 0.8-8.3 micrograms 1(-1) for the four regions and 0.9-61.4 micrograms 1(-1) for Rovescala. Statistically significant variables for urinary ETU levels were smoking and wine drinking.

Adolescent↗

PubMedDate not supplied

Reference values for lung function tests in females. Regression equations with smoking variables.

Prediction formulas for static and dynamic spirometry, gas distribution, static lung mechanics and transfer test were derived from measurements in healthy females. The measurements included total lung capacity, residual volume, airway resistance, static elastic recoil pressure of the lung, static compliance, closing volume, slope of the alveolar plateau (phase III), flow-volume variables (including mean transit time) during breathing of air or a helium/oxygen mixture, and conventional spirometric indices. The results from 86 smokers and 100 never-smokers were evaluated separately and combined. For all lung function tests, a single regression equation including time-related smoking variables, valid for both smokers and never-smokers, was obtained. For many lung function tests, a nonlinear age coefficient resulted in a significant reduction in variance compared with simple linear models. Heavy tobacco smoking influenced most lung function tests less than ageing from 20 to 70 years, but for airway resistance, volumic airway conductance, closing volume, phase III, FEV1/VC, volume of isoflow and mean transit time the opposite was found.

Adult↗

PubMed1986

Reference values for lung function tests in men: regression equations with smoking variables.

Prediction formulas for static and dynamic spirometry, gas distribution, static lung mechanics and the transfer test were derived from measurements in healthy men. The measurements included total lung capacity, residual volume, airways resistance, static elastic recoil pressure of the lung, static compliance, closing volume, slope of the alveolar plateau (phase III), flow-volume variables (including mean transit time) during breathing of air or a helium/oxygen mixture, and conventional spirometric indices. The results from 146 smokers and 124 never-smokers were evaluated separately and combined. For all lung function tests a single regression equation was obtained. The prediction formulas included time-related smoking variables and were valid for both smokers and never-smokers. For many lung function tests, a nonlinear age coefficient resulted in a significant reduction in variance compared with simple linear models. Heavy tobacco smoking influenced most lung function tests less than ageing from 20 to 70 years, but for airways resistance, transfer factor and phase III the opposite was found.

Adult↗

PubMed1993

[Reference values of the height and weight growth and growth rate of Belgian boys and girls 3-18 years of age].

BACKGROUND: Belgian growth standards have until now been based on cross-sectional studies. This paper describes the first Belgian longitudinal growth standards for height and height velocity and recent cross-sectional standards of weight-for-age. POPULATION AND METHODS: The study was conducted between 1955 and 1975, initially on 259 Belgian boys and girls born in Brussels between 1955 and 1958. Only 48 boys and 50 girls were still being checked for height and weight at the end of the study. The distance charts show the classical centile lines; the height standards are provided with growth curves for the typical early average and late-maturing child in the population. The velocity charts show centiles for whole-year increments in height. Individual-type velocity curves are also provided. RESULTS: Comparison between these standards and those for British children shows that the Belgian children (essentially the girls) are taller than the British, probably due to more rapid maturation.

Adolescent↗

PubMed1993

Reference values and prediction equations for maximal expiratory flow rates in non-smoking normal subjects in Madras.

Maximal Expiratory Flow Rates such as Peak Expiratory Flow Rate (PEFR), rates at 25%, 50% and 75% of forced vital capacity (V max 25%, V max 50% and V max 75%) and forced expiratory flow during the middle half of forced vital capacity (FEF 25-75%) were measured in 273 healthy non-smoking adults (144 males, 129 females) aged 15-63 years living in Madras. Regression equations were derived for men and women for predicting maximal expiratory flow rates for adults in South India. Expiratory Flow Rates at lower lung volumes in men were similar to those reported for caucasians, but higher than those reported for western Indian Subjects. However, in women the flow rates were similar to those of western Indians and lower than those of caucasians, probably due to indoor air pollution since childhood. These data may suggest that expiratory flow rates at lower lung volumes may not show ethnic variability.

Adolescent↗

PubMed1991

[Reference values of global and regional myocardial function for stress echocardiography].

Two-dimensional echocardiography has become a sensitive method to differentiate between normal and pathological myocardial function during exercise. Examining 50 healthy volunteers we determined normal values for global and regional left-ventricular function during bicycle exercise. Ejection fraction increased from 59 +/- 10% at rest to 85 +/- 7% at 210 watts workload, endsystolic volume decreased from 22.1 ml/m2 at rest to 7.1 ml/m2 at 210 watts. Enddiastolic volume showed a tendency to decrease from 55 +/- 21 ml/m2 at rest to 45 +/- 23 ml/m2 at 210 watts. Quantitative analysis showed an extended distribution both for Centerline- and Radiant-Method, during exercise Centerline-Method was superior. Two-dimensional echocardiography is useful for assessment of global and regional myocardial function during exercise. Decrease of ejection fraction or increase of endsystolic volume seems to be a pathological marker. Enddiastolic volume is a less useful parameter for evaluating left-ventricular function during stress. Quantitative analysis of left ventricular wall motion can be applied with restrictions.

Adult↗