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PubMed2002

Reference value of semen quality in Chinese young men.

The purpose of the study was to evaluate semen quality in young Chinese men and to establish reference values. Normal healthy young men from seven geographical areas were enrolled. The study showed that the mean sperm volume was 2.61 mL, and mean percent of sperm with forward progression was 59.89, while median of semen viability was 79.0%, and geometric mean of semen density was 55.45 x 10(6)/mL. Proportion of routine semen indexes that met World Health Organization (WHO) criteria were as follows: 81.9% for semen volume, 91.1% for liquefaction time, 93.4% for viscosity, 90.8% for pH, 81.3% for sperm with forward progression, 65.3% for sperm viability, 93.8% for semen density, 98.8% for normal sperm morphology, and 89.1% for total sperm count. Participants whose sperm met all WHO standard parameters accounted for 42.3%. Because the infertility rate in China is about 10-15%, the fifteenth percentile of semen parameters might be used as the lower limit of reference values, which may be more appropriate for young Chinese men. The fifteenth percentiles of parameters in this study were as follows: 1.5 mL for semen volume, 7.2 for pH value, 45% for proportion of sperm with forward progression, 68% for sperm viability, 30 x 10(6)/mL for semen density, 68% for proportion of sperm with normal morphology, and 50 x 10(6) for total sperm count.

Adult↗

PubMed1991

Reference values and prediction equations for normal lung function in a non-smoking white urban population.

Prediction equations for normal lung function have been derived from tests on 179 healthy, non-smoking, white urban dwellers. The subjects, 96 women (height 1.46-1.77 m) and 83 men (height 1.61-1.96 m) aged 18-86 years, underwent measurements of spirometric flow and volume, multi-breath helium dilution lung volumes, and single breath carbon monoxide transfer factor and the single breath nitrogen washout test. Regression analysis using height, age, and weight as independent variables was used to provide predicted values for both sexes. Correlation coefficients were similar to those found in previous studies but normal ranges for spirometic measurements were narrower than in many previous studies, and spirometric flow and volume measurements were higher than those obtained in studies that included cigarette smokers, reflecting our more stringent criteria for selecting subjects and the newer standardised technical methods adopted. Multi-breath helium dilution values for total lung capacity were similar to those found in previous studies but the inspiratory vital capacity was larger and the residual volume reduced. Values for carbon monoxide transfer factor and the single breath nitrogen washout did not differ significantly from existing values. A complete set of lung function reference values and prediction equations for both sexes has been derived from a single population. The exclusion of cigarette smokers and subjects with respiratory symptoms has produced values that should have a greater sensitivity in the detection of mild lung disease.

Adolescent↗

PubMed2005

Determination of biological reference values for chlorpyrifos metabolites in human urine using a toxicokinetic approach.

Urinary biomarkers of chlorpyrifos (CPF) exposure are often measured in field studies, although biological reference values (BRVs) are not yet available to assess health risks. This study aimed at proposing BRVs for CPF metabolites in workers' urine based on a toxicokinetic approach. As a first step, a toxicokinetic model was developed, using published human kinetic data, to link the absorbed dose of CPF under a variety of exposure routes and temporal scenarios to the urinary excretion of its major metabolites, 3,5,6-trichloro-2-pyridinol (3,5,6-TCP) and alkyl phosphates (AP). The model was then used to propose BRVs for CPF metabolites in urine below which workers should not experience adverse health effects. This was achieved by linking (1) a literature-reported, repeated CPF no-observed-effect level (NOEL) daily exposure dose for the inhibition of red-blood-cell acetylcholinesterase activity to a corresponding absorbed daily dose, and (2) this absorbed daily dose to the urinary excretion of CPF metabolites. Model simulations under a variety of exposure scenarios showed that the safest BRVs are obtained from a dermal exposure scenario with the slowest absorption rate compatible with available literature data rather than from respiratory or oral exposure scenarios. Also, model simulations showed that, for a given total absorbed dose, absorption over 8 hours results in smaller 3,5,6-TCP and AP urinary excretion rates than those obtained from the same dose absorbed over shorter durations. From these considerations, BRVs were derived by simulating an 8-hour dermal CPF exposure such that the total absorbed daily dose corresponds to the absorbed NOEL. The reference values are proposed in the form of total amounts of 3,5,6-TCP and AP metabolites excreted in urine over chosen time periods (24 and 48 hours).

Absorption↗

PubMed1983

[Biological variations and reference values of transferrin, immunoglobulin A and orosomucoid].

To explain laboratory test results, it is necessary to know for each parameter the biological variation factors and the reference values. The principal biological variations factors for transferrin, IgA and orosomucoid (age, sex, body weight, exercise, puberty, menstrual cycle, professional class and work conditions) have been studied on a sample of the population who have come to the Center for Preventive Medicine (Vandoeuvre-Lès-Nancy, France) for a health check-up (males and females, 4-60 years). We have assembled bibliographical data concerning the other main variations factors. Our results (variations calculated on the medians) and literature results (variations calculated on the medians or on the means) are presented together. These are respectively: 1. For transferrin: age (new-born/20-30 years: -29 to -71%, 50-60 years/20-30 years: -15%), menstrual cycle (+15%), pregnancy (+37 to +70%), exercise (+9 to +13%), oral contraceptives (+10 to +62%), medications (danazol: +60%, testosterone: -13%, D-penicillamine: -13 to -30%, L-asparaginase: -68%); 2. For IgA: age (new-born/20-30 years: -98 to 100%, 3-5 years/20-30 years: about -50%, 50-60 years/20-30 years: up to +60%), sex (men/women: up to +30%), exercise (+14%), pregnancy (-20%), obesity (+30%), season (winter/summer: +10 to +14%, in Africa humid season/dry season: +20%), oral contraceptives (-11 to -40%), medications (L-asparaginase: +36 to +60%), socio-economical factors (black/white: +20 to +75%); 3. For orosomucoid: age (new-born/20-30 years: -70 to -95%, 60-80 years/20-30 years: up to +50%), sex (men/women: up to +15%), obesity (+26%), menstrual cycle (+14%), pregnancy (-20 to -30%), oral contraceptives (-21 to -36%), medications (L-asparaginase: +17%, anabolic steroids: +68%). We determined the three proteins reference values with a nephelometric method.

Age Factors↗

PubMed1997

On the correct determination of reference values for serum antibodies against pigeon serum antigen using a group of healthy blood donors.

An enzymatic immunoassay was developed in order to evaluate the statistical distribution of IgG serum antibodies against pooled pigeon sera antigen in 102 healthy blood donors (HBD). A non-normal distribution was obtained as demonstrated by abnormal values of skewness (2.02) and kurtosis (6.50). A cut-off point (0.120) was determined from the mean plus 2 standard deviations of the optical density values obtained in the HBD group. This value was able to segregate 94% of subjects. However, when calculation of the mean less 2 SD was performed to delimit 95% of the samples, an aberrant negative value was obtained. In contrast, when the nonparametric method of percentile calculation was applied, an optical density value of 0.130 discriminated 97.5% of samples. In addition, the interval between p97.5 and p2.5 delimited 95% of samples. We conclude that when reference values and cut-off point are determined from an enzymatic immunoassay, careful analysis of the statistical distribution of reference values is necessary in order to avoid the inappropriate application of parametric procedures as demonstrated in this study for antibodies against pigeon serum antigens.

Adult↗

PubMedDate not supplied

[Reference values for plasma amino acids in the course of pregnancy].

Reference values for 26 plasma amino acids were determined by ion exchange chromatography in 29 healthy pregnant women (1st to 3rd trimenon). The results are given as P50 (P7-P93). In the course of pregnancy the concentrations of amino acids generally decrease. Threonine, however, shows a distinct, statistically significant increase. The interindividual concentration ranges are low and they show little change in the course of pregnancy. The data presented here are relevant for dietary treatment of metabolic disorders, e.g. maternal phenylketonuria in pregnants.

Adult↗

PubMed2000

Reference values for activated coagulation time in cats.

OBJECTIVE: To establish reference values for activated coagulation time (ACT) in cats by use of jugular venipuncture and direct collection of blood into ACT vacuum tubes. ANIMALS: 100 clinically normal cats that were to have elective surgery performed at a private practice. PROCEDURE: Collection of 3 blood samples for ACT measurement was attempted for each cat at the time of elective surgery: sample 1, obtained before sedation; sample 2, tube 1 of 2 consecutive samples obtained from a single venipuncture of the contralateral jugular vein after sedation with acepromazine and ketamine hydrochloride; and sample 3, tube 2 collected immediately following collection of sample 2 without removing the needle from the vein. Venipuncture quality was rated subjectively on a 3-point scale. RESULTS: Median ACT were 95 seconds for each sample group. The middle 95% of values ranged inclusively from 55 to 185 seconds (sample 1), 65 to 135 seconds (sample 2), 45 to 145 seconds (sample 3), and 55 to 165 seconds overall (samples 1, 2, and 3). Significant differences in ACT values were not detected between sample groups. Significant relationships between ACT and venipuncture quality or sex of cat were not detected. CONCLUSIONS AND CLINICAL RELEVANCE: With the ACT protocols used, clinically normal cats had ACT of < 165 seconds. The ACT in cats does not appear to be significantly affected by sex, sedation with acepromazine and ketamine, or by moderately traumatic venipunctures. These results refute widespread statements that ACT should be < 65 seconds in healthy cats. Cats with ACT repeatedly > 165 seconds should be further evaluated for hemostatic disorders.

Acepromazine↗

PubMed1990

Reference values of indicators for WHO neurobehavioral core test battery.

The reference values of the indicators for WHO neurobehavioral core test battery (NCTB) and the factors of age and sex on the performance preliminarily were analyzed. The results showed that there was a significant interference with the performance of behavior involved in hand movement and hand operation, a slight interference with the performance of behavior in simple reaction time, digit span and Benton visual retention, and almost no interference with the performance of behavior in mood due to age. It seemed that sex had hardly any effect on the indicators for WHO NCTB.

Adolescent↗

PubMedDate not supplied

Inductively coupled atomic emission spectrometry and neutron activation analysis for the determination of element reference values in human lung tissue.

An investigation was undertaken in order to assess the performance of neutron activation analysis and inductively coupled plasma atomic emission spectrometry techniques for determining reference values for minor and trace elements in human lungs of urban subjects. Results show that in both instances experimental conditions must be carefully optimized to guarantee reliability of experimental data. Strict criteria for tissue sampling and pretreatment also had to be set. Provisional reference values for ca. 50 elements could thus be established.

Animals↗

PubMed1991

Quantitation of serum apolipoprotein A-I, A-II, B, C-II, C-III and E in healthy Japanese by turbidimetric immunoassay: reference values, and age- and sex-related differences.

Serum apolipoproteins (Apo) A-I, A-II, B, C-II, C-III and E were determined in healthy Japanese subjects (male 1,603, female 1,800, aged 4-95 yr) by the turbidimetric immunoassay, with six kinds of automated instruments, and the commercial reagent kits with standards. There was a high degree of interlaboratory comparability of analytical values among the 15 participating laboratories. The reference values were calculated for adult males and females (male 677, female 467, aged 21-60 yr). Apo A-I and E levels were significantly higher and Apo C-II and C-III were significantly lower in females than in males. Furthermore, serum Apo A-I and A-II tended to decrease, and Apo B to increase with age. Apo C-II, C-III and E tended to decrease after 60 yr of age.

Adolescent↗

PubMed1991

Reference values for the nickel concentration in human finger nails.

A reference value for the nickel concentration in finger nails from people who are not occupationally exposed to nickel was determined on the basis of nail samples from 95 healthy individuals. The mean +/- standard deviation was 1.19 +/- 1.61 mg/kg and the median was 0.49 mg/kg (range 0.042-7.50 mg/kg). The 95% confidence interval of the population mean was 0.51-1.26 mg/kg and the 95% confidence interval of the population median was 0.39-0.74 mg/kg. The random sample consisted of 59 women and 36 men. No significant difference between the nickel levels in finger nails from men and women could be demonstrated. The age of the subjects varied from 16 to 66 years. There was no correlation between age and nickel concentration in finger nails.

Adolescent↗

PubMedDate not supplied

[Reference values for FVC, FEV1 and FEF25-75% in school children].

Reference values for FVC, FEV1 and FEF25-75% have been developed on a sample of 2500 healthy school-children (nonsmokers) from Split, ranging in age from 6 to 18 years. We measured respiratory parameters (FVC, FEV1 and FEF25-75%) in a standing position, statistically analysed the results and presented them tabularly with regard to age, standing and sitting height and body weight. The results revealed a high correlation between FVC and FEV1 with respect to age, standing and sitting height and body weight. There was no significant difference between respiratory parameters and the two measured positions (standing and sitting positions). A statistically significant difference was noted in the ventilatory parameters of the children (FVC, FEV1) between the boys and girls. Regression analysis was performed for all three respiratory parameters (FVC, FEV1 and FEF25-75%) vs age and height, separately for boys and girls. Nomograms for predicting respiratory parameters for boys and girls from the Dalmatian region were also constructed in order to enable better future epidemiologic studies for early detection of ventilatory impairment in school-children.

Adolescent↗

PubMed2000

[Reference values of chemical blood parameters in puppies during the first eight weeks of life].

Reference values were determined for blood plasma concentrations of albumin, total protein, glucose, total bilirubin, urea, creatinine, cholesterin, triglycerides, total calcium und anorganic phosphate as well as the activities of alkaline phosphatase, alanine-amino-transferase (ALT) and glutamate-dehydrogenase based on 109-124 healthy puppies at different times (1st-3rd, 8th-10th, 28th-33rd, and 50th-58th day of life). In addition, all the results were calculated separately for the breeds involved in this study (Beagle [n = 34-40], German Shepherd [n = 32-35] and Golden Retriever [n = 43-53]). Furthermore, male and female puppies were compared. All examined parameters showed remarkable dynamics during the suckling period. Often the values exceeded respectively fell below the reference ranges for adult dogs. Significant systematic breed influences as for instance a significantly lower glucose concentration for the German Shepherd puppies were also found for other parameters, especially for alkaline phosphatase and ALT. However, differences between male and female animals were only present sporadically and were of minor clinical relevance. The gathered breed differences show that it is worthwhile not only to acquire age specific reference ranges but also breed specific reference ranges for selected parameters. On the other hand, reference ranges without the definition of the breed can only be used for orientation.

Aging↗

PubMed1990

Reference values for essential and toxic elements in human milk.

Dependable reference values (RVs) for the concentration ranges of health-related elements in human biological fluids and organs are to date of acknowledged importance for an early recognition of pathological states. On the other hand, the present lack of reliable data on levels to be considered as baseline values for elements of major concern from a toxicological, environmental and nutritional point of view demands the development of experimental procedures capable of satisfying the requirements of detection power, specificity and applicability on a large scale necessary to generate vast amounts of reliable measurements. As part of an overall monitoring program, an investigation was undertaken with the following two aims: a) the present suitability of inductively-coupled plasma atomic emission spectrometry (ICP-AES) to identify and quantitate minor and trace elements in human milk with the necessary accuracy and precision; b) assessment of RV concentrations for Al, Ba, Cd, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb and Zn. Four population groups were selected (each with 9 subjects) resulting from the various combinations of smokers and non-smokers from an urban or a rural environment. Strict eligibility criteria were adopted in order to select only women in good health, no known occupational exposure and whose nutritional habits could be described in detail. A scrupolous and systematic approach was adopted to minimize every possible source of elemental contamination from the sampling step onwards. Digestion of samples was attempted both with mixtures of strong acids and by resorting to acid-assisted mineralization in a microwave oven. Both methods were satisfactory for subsequent introduction into the torch of the ICP-AES system. The outcome of this pilot study gave the following median RVs for concentration (in mg/kg): Al, 0.14; Ba, 0.013; Cd, 0.002; Cr, 0.016; Cu, 0.40; Fe, 0.72; Li, 0.004; Mg, 29.4; Mn, 0.006; Ni, 0.05; Pb, 0.016; and Zn, 3.08.

Female↗

PubMed2005

Reference values for serum silicon in adults.

Silicon is an essential nutrient of fundamental importance to human biology. It has been shown that silicon is required for bone, cartilage, and connective tissue formation. However, the assessment of silicon concentration is difficult as reference values are lacking. The aim of the present study was to establish reference values for apparently healthy individuals. Silicon concentrations were determined in serum of 1325 healthy subjects 18-91 years of age using atomic absorption spectrometry. Medians for serum silicon concentrations showed a statistically significant age and sex dependency. In men 18-59 years of age the median was 9.5 micromol/L and decreased to 8.5 micromol/L at 60-74 years of age. In women there was an increase in the median from age 18-29 years (10.00 micromol/L) to 30-44 years (11.10 micromol/L) followed by a decrease in the age group of 45-59 years (9.23 micromol/L). In subjects aged over 74 years the median serum silicon values were 7.70 micromol/L for men and 8.00 micromol/L for women. The most important findings in this study are the decrease of silicon and the course of the silicon concentrations with age, especially in women. The present study is an important prerequisite for studies that aim to identify the health effects and medical implications of silicon.

Adolescent↗

PubMed1996

Evaluation of reference values for erythrocyte glutathione.

The analytical, intra-individual and inter-individual variations as well as the best storage conditions were determined for erythrocyte glutathione, and the reference values were established. A total of 396 apparently healthy people, 206 male, and 190 female, were randomly selected from villages and cities of the southern part of Turkey. The distribution was Gaussian and no significant difference was observed between the male and the female subjects. The mean (standard deviation) of the population investigated for glutathione was 6.9 (1.0) mumol/gHb. The analytical, intra-individual and inter-individual variations were assessed in 20 apparently healthy subjects and were found to be 4.63%, 13.67% and 11.16%, respectively. Whole blood stored at -70 degrees C for up to 10 days was shown to be the best storage condition for erythrocyte glutathione determination. The results of the index of individuality showed that glutathione reference values could be used for diagnostic purposes.

Adult↗

PubMed1995

RefVal: a program implementing the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values.

RefVal is a computer program that implements the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values. The program performs the following main tasks: graphical display of the distribution of reference values, identification or elimination of outliers, testing of the fit of the distribution to Gaussian shape (coefficients of skewness and kurtosis, Anderson-Darling's test, Cramér-von Mises' test, Kolmogorov-Smirnov's test), non-parametric and parametric estimation of reference limits (fractiles, percentiles). The parametric estimation method is based on a two-stage mathematical transformation of data: (1) Manly's exponential transformation (to remove skewness) and (2) John and Draper's modulus transformation (to adjust for remaining kurtosis). The program exists in different versions. The paper describes two of these: (1) a library of FORTRAN functions and subroutines and (2) a Pascal PC program that runs under MS-DOS.

Bias↗

PubMed2006

Doppler myocardial imaging in adult male rats: reference values and reproducibility of velocity and deformation parameters.

AIM: Limited data are available about the use of Doppler myocardial imaging (DMI) in small animals. We intend to provide reference values for velocity, strain and strain rate in a large group of healthy rats and studied the reproducibility and repeatability of these parameters. METHODS AND RESULTS: A total of 33 male Wistar rats (503+/-41g) underwent baseline transthoracic echocardiography with DMI of the anterior and inferior wall in a short-axis view using a 13MHz linear probe. Adequate tissue Doppler measurements could be obtained in 30 rats. On average 10+/-4 consecutive cycles were studied in post-processing using dedicated software (SPEQLE). Mean radial peak systolic velocity, strain and strain rate were respectively -0.8+/-0.3cm/s, 38+/-8% and 9.1+/-2.0/s in the anterior wall and 3.1+/-0.6cm/s, 49+/-10% and 13.7+/-3.7/s in the inferior wall. The reproducibility and repeatability of the DMI measurements assessed in 10 rats was good. CONCLUSION: DMI is feasible and reproducible in healthy rats. Establishing reference values opens new perspectives towards the use of strain and strain rate imaging in small rodents in the assessment of myocardial diseases.

Animals↗