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PubMed2005

Reference values for clinical chemistry and clinical hematology parameters in cynomolgus monkeys.

BACKGROUND: In vivo xenotransplantation modeling in large animal species is often performed in nonhuman primates, including baboons. For proper data interpretation, reference values for clinical chemistry and hematology are required. METHODS: These values are available from baseline levels in animals subjected to tolerability/pharmacokinetic studies. For each individual study two tests for clinical chemistry and hematology were performed before the start of treatment. RESULTS AND CONCLUSION: Baseline levels were determined in 27 males and 15 females, in total 106 determinations (53 in males, and 53 in females). For a number of parameters levels in cynomolgus monkeys show clear differences from those in baboons. These data are reported here to provide baseline values for veterinarians and investigators using nonhuman primates in experimental studies.

Animals↗
PubMed1999

Reference values of exhaled nitric oxide for healthy children 6-15 years old.

Nitric oxide (NO) can be detected in human exhaled air, and its endogenous production is increased in patients with asthma. It may provide a noninvasive means for measuring airway inflammation. The aim of this study was to establish reference values for exhaled NO concentrations in a large number of healthy school-age children. We measured exhaled NO levels in 159 white healthy children (88 girls, 71 boys, age range 6-15 years) recruited from two public schools of Padua, Italy. Exhaled NO levels in exhaled gas were measured by a tidal breathing method with a chemiluminescence analyzer, and NO steady-state levels were recorded. Nasal NO levels were measured by direct sampling from the nose during mouth breathing. The mean concentration of endogenous NO in orally exhaled gas was 8.7 parts per billion (ppb) (95% confidence interval (C.I.), 8.1-9.2 ppb) and sampled data followed a log-normal distribution (Kolmogorov-Smirnov d = 0.77, P > 0.2). No difference was found between boys (mean value, 8.4 ppb; 95% C.I., 7.3-9.4 ppb) and girls (mean value, 8.9 ppb; 95% C.I., 7.9-9.9 ppb). No significant correlation was found between age, height, or spirometric data and exhaled NO levels (r < 0.2). The mean value of nasal NO concentrations was 216 ppb (95% C.I., 204-228 ppb). There was no correlation between exhaled and nasal NO values (r = 0.16, P = ns). In conclusion, this study establishes a reference range for exhaled NO values measured by a tidal breathing method in children between age 6-15 years. The observed levels are independent of age, gender, and lung function, and can be used to monitor airway inflammation in asthmatic children.

Adolescent↗
PubMed1999

Transcranial color Doppler sonography of basal cerebral arteries in 182 healthy subjects: age and sex variability and normal reference values for blood flow parameters.

OBJECTIVE: Only a limited number of transcranial color-coded Doppler studies have provided ranges for the normal reference values of cerebral hemodynamic parameters. These reports are not fully convergent in relation to the range of values or to the age and sex dependence of blood flow parameters. The aim of the present study was to provide data regarding normal reference ranges. SUBJECTS AND METHODS: We examined 182 healthy volunteers (79 men and 103 women; age range, 20-86 years old) with color-coded Doppler sonography via a temporal acoustic window with a 2.5-MHz transcranial probe. The subjects were divided into three age groups: 20-40 years old (group 1), 41-60 years old (group 2), and more than 60 years old (group 3). Angle-corrected peak systolic, end-diastolic, and mean velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries. RESULTS: Mean velocity values for middle, anterior, and posterior cerebral arteries in age group 1 were 81+/-20, 56+/-14, and 52+/-12 cm/sec (mean +/- SD), respectively. In group 2, the values were 73+/-19, 53+/-16, and 51+/-12 cm/sec (mean +/- SD), and in group 3, the values were 59+/-11, 44+/-11, and 40+/-9 cm/sec (mean +/- SD). Decrease in blood flow velocities and a concomitant increase in impedance indexes were found in all vessels with advancing age-findings that were most pronounced in subjects who were more than 40 years old. In the 20- to 40-year-old group, mean velocities for all vessels were higher in women than in men, whereas impedance indexes were not significantly different. CONCLUSION: Flow velocities in basal cerebral arteries range widely and are significantly age dependent. Age and sex matching of Doppler sonographic data is a prerequisite for clinically valuable conclusions.

Adult↗
PubMed2002

Reference values for transverse cerebellar diameter throughout gestation.

The transverse cerebellar diameter (TCD) is well established in the ultrasound literature as a reliable parameter for estimating the duration of gestation. In cases of growth restriction the cerebellum is usually spared, making TCD a reliable indicator of gestational age even when other parameters fall off the appropriate growth curve. The purpose of this study is to establish normal values for the transverse diameter of the cerebellum in pathology specimens, and to determine if these values correlate with those obtained by ultrasound. We examined 96 specimens ranging from 14 to 42 weeks gestational age and found that our values correlate well with those published in the ultrasound literature. Mean TCD with 2 standard deviations for each gestational week were determined as reference values.

Autopsy↗
PubMedDate not supplied

[Reference values for the peak expiratory flow].

INTRODUCTION: Peak expiratory flow (PEF) is an important screening method for investigation and follow-up of the pulmonary function. Since reading the obtained PEF results requires reference values, the aim of this study was to establish normal values for PEF in our adolescent population. MATERIAL AND METHODS: The investigation included 1154 healthy teenagers aged from 15 to 19 years using a peak flow meter Harlow, Essex CM 2ED. Detailed explanations, purpose of investigation and function demonstrations were done prior to testing. Results were statistically analyzed. RESULTS: Obtained results showed an increase of PEF values with age and body height in both sexes. Elevation of PEF was more significant in boys; high correlation was found in regard to age and height in boys and moderate correlation in girls. DISCUSSION AND CONCLUSION: Regression equations for sex, age and height were made after measurements and data analysis. PEF values can be easily calculated knowing one's age and height.

Adolescent↗
PubMed1999

Reference values for lung function tests. I. Static volumes.

Static lung volume (LV) measurements have a number of clinical and research applications; however, no previous studies have provided reference values for such tests using a healthy sample of the adult Brazilian population. With this as our main purpose, we prospectively evaluated 100 non-smoking subjects (50 males and 50 females), 20 to 80 years old, randomly selected from more than 8,000 individuals. Gender-specific linear prediction equations were developed by multiple regression analysis with total lung capacity (TLC), functional residual capacity (FRC), residual volume (RV), RV/TLC ratio and inspiratory capacity (IC) as dependent variables, and with age, height, weight, lean body mass and indexes of physical fitness as independent ones. Simpler demographic and anthropometric variables were as useful as more complex measurements in predicting LV values, independent of gender and age (R2 values ranging from 0.49 to 0.78, P < 0.001). Interestingly, prediction equations from North American and European studies overestimated the LV at low volumes and underestimated them at high volumes (P < 0.05). Our results, therefore, provide a more appropriate frame of reference to evaluate the normalcy of static lung volume values in Brazilian males and females aged 20 to 80 years.

Adult↗
PubMed2004

[Reference values in oral health-related quality of life for the abbreviated version of the Oral Health Impact Profile].

Questionnaires measuring oral health-related quality of life (OHRQoL) need reference values for their interpretation. Population-based norms for a questionnaire allow a comparison of the level of OHRQoL observed for an individual or a group of subjects with the level of that construct in the general population. The aims of this study were to establish normative values for abbreviated instruments of the German version of the Oral Health Impact Profile (OHIP-G). Data of the long OHIP-G (53 items) were collected in a national survey (N=2050, age: 16-79 years). Three short instruments with 5 (OHIP-G5), 14 (OHIP-G14) and 21 items (OHIP-G21) were derived from the long OHIP. Norms were computed for the OHIP-G summary score (simple sum of all item responses). The OHIP-G summary score distribution was described by empirical cumulative distribution functions. Because denture usage was strongly associated with OHIP-G summary scores, percentile-based norms were stratified by this variable. Among subjects without dentures, 50% of the population had OHIP-G5 or OHIP-G14 scores 0 and OHIP-G21 scores < or = 2. Summary scores for the three abbreviated OHIPs were < or = 2, < or = 4, and < or = 7 for subjects with removable dentures and < or = 3, < or = 6, and < or = 8 for subjects with complete dentures. Among subjects without dentures, 90% of the population had < or = 4 OHIP-G5, < or = 11 OHIP-G14, and < or = 16 OHIP-G21 points. For subjects with removable dentures, the figures were < or = 7, < or = 17, and < or = 26 points for OHIP-G5, OHIP-G14 and OHIP-G21, respectively; and for subjects with complete dentures, < or = 10, < or = 25, and < or = 38 points, respectively. The presented norms will provide a frame of reference in future cross-sectional studies in the general population or samples with specific oral conditions when OHRQoL is measured by OHIP-G5, OHIP-G14 or OHIP-G21.

Adolescent↗
PubMed2002

Reference values for serum biochemical parameters in free-ranging harp seals.

BACKGROUND: The harp seal (Phoca groenlandica) is one of the most important predators in the Northeastern Atlantic ecosystem. Establishing biochemical reference intervals is important for evaluating the health status of harp seals kept in captivity and for evaluating the effects of environmental changes on the health of populations in the wild. OBJECTIVE: The purpose of this study was to determine reference values for serum biochemical parameters in wild adult harp seals using readily available current methods. METHODS: Blood samples were obtained from 14 adult female harp seals and 9 suckling pups on the pack ice of the Greenland Sea in early March 1998. Seven seals were humanely killed on the ice by permission of the Norwegian Directory of Fisheries and in conjunction with several other research projects. The seals were sampled within 15 minutes postmortem. Remaining seals were captured alive and sampled via the extradural intravertebral vein. Serum biochemical parameters were measured using a Technicon Axon analyzer and included electrolytes (sodium, chloride, potassium, magnesium, and calcium), substrates (free fatty acids, triglycerides, fructosamine, and glucose), end products (urea and uric acid), and proteins (total protein, globulins, and albumin). Serum protein electrophoresis also was done. Data were tested for normality and reference limits were calculated as mean +/- 1.96 X SD. Results between groups were compared using 2-tailed t-tests. RESULTS: Serum levels of glucose and triglycerides were lower, but serum levels of urea were higher in dead animals than in animals that were captured alive. Serum levels for 7 of 17 parameters were significantly different in pups compared with adults. Separate reference intervals were calculated for adult seals and seal pups. CONCLUSION: Both sampling method and age should be considered when evaluating the results of future analysis of serum parameters in wild and captive harp seals.

Age Factors↗
PubMed2001

Reference values for dynamic responses to incremental cycle ergometry in males and females aged 20 to 80.

Interpretation of incremental cardiopulmonary exercise tests (CPET) might be enhanced by considering the simultaneous rates of change of certain key variables, e.g., Delta oxygen uptake/Delta work rate (Delta VO(2)/Delta WR), Delta heart rate/Delta VO(2) (Delta HR/Delta VO(2)), Delta ventilation/Delta carbon dioxide production (Delta VE/Delta VCO(2)), and the linearized Delta tidal volume/Delta VE (Delta VT/Delta lnVE) relationships. However, there are no published age- and sex-dependent reference values for these relationships that were appropriately obtained in randomly selected subjects. We therefore prospectively evaluated 120 sedentary individuals (60 male, 60 female, age 20 to 80 yr) who were randomly selected from more than 8,000 subjects, and submitted to standard ramp-incremental CPET on an electronically braked cycle ergometer. We found that sex and age significantly influenced several of the dynamic relationships, in addition to anthropometric attributes (p < 0.05). A comprehensive set of linear prediction equations is provided; the limits of normality (at the 95% confidence level) differed substantially from previous recommendations based on single discrete values. These data therefore provide a frame of reference for assessing the normalcy of the response profiles of four standard indices of metabolic, cardiovascular, and ventilatory function during rapidly incremental cycle ergometry in sedentary males and females up to 80 yr of age.

Adult↗
PubMed1986

Statistical treatment of reference values in laboratory medicine: testing the goodness-of-fit of an observed distribution to the Gaussian distribution.

During the preparation of an IFCC-recommendation on the statistical treatment of reference values, five tests of the goodness-of-fit of an empirical distribution to the Gaussian distribution were computerized and studied by Monte Carlo simulations: tests based on the coefficients of skewness and kurtosis, the Anderson-Darling's test, the Cramér-von Mises' test, and the Kolmogorov-Smirnov's test. Approximations for test probabilities were developed for all these tests. Based on the simulation results it is recommended to use the combination of the two coefficient-based tests for monitoring the transformation of an empirical distribution to Gaussian shape and to use the Anderson-Darling's test as an all-round test for Gaussianity.

Biometry↗
PubMed1980

Reference values for flow-volume curves during forced vital capacity breathing in male children and young adults.

127 non-smoking males aged 8-25 years were studied to obtain normal reference values for flow-volume (FV) curves. Analysis of variance (ANOVA) showed significant differences for all indices (PEF; MEF 25%, 50%, 75%; PIF; MIF 25%, 50%, 75%) in the first three age-groups (8-10, 11-13 and 14-16 years); the three last groups (17-19, 20-22 and 23-25 years) did not show any significant variation of FV curve data. Male subjects older than 16 years showed a negative correlation between maximal expiratory flow at 50% of forced vital capacity and standing height. Multiple regression equations relating FV curve indices to age and anthropometric data are calculated.

Adolescent↗
PubMed1991

[Spirometric reference values in the Senegalese child and adolescent aged 6 to 23 years].

The authors have studied five hundred sixty spirographs of children and adolescents of the two sexes. Two hundred seventy four girls an two hundred eighty six boys--all of them are pupils in two schools of Dakar. The exploitation to the results shows a significant deficit of the spirometric reference values found in our specimen of population with regard to the reference norms, established from an european population of the same age height and sex. The explanation is an anthropometric difference, the west-african black population is macroskeletal, the trunk being proportionately shorter than the limbs. Knowing that the data proved in different african countries are not systematically superimposable, this work find his interest in the applications in medical practice, in general or thoracic surgery, in epidemiologic studies and for the assessment of sequela in forensic medicine.

Adolescent↗
PubMed2001

A survey of iodine intake and thyroid volume in Dutch schoolchildren: reference values in an iodine-sufficient area and the effect of puberty.

BACKGROUND: Iodine deficiency and endemic goiter have been reported in the past in The Netherlands, especially in the southeast. OBJECTIVE: To evaluate iodine intake and thyroid size in Dutch schoolchildren, contrasting those living in a formerly iodine-deficient region in the east (Doetinchem) with those living in an iodine-sufficient region in the west (Amsterdam area). DESIGN: Cross-sectional survey of 937 Dutch schoolchildren aged 6--18 years, of whom 390 lived in the eastern and 547 in the western part of the country. METHODS: Thyroid size was assessed by inspection and palpation as well as by ultrasound. Iodine intake was evaluated by questionnaires on dietary habits and by measurement of urinary iodine concentration. RESULTS: Eastern and western regions were similar with respect to median urinary iodine concentration (15.7 and 15.3 microg/dl, NS, Mann-Whitney U test), goiter prevalence by inspection and palpation (0.8 and 2.6%, P=0.08, chi-squared test), and thyroid volumes. The P97.5 values of thyroid volumes per age and body surface area group were all lower than the corresponding sex-specific normative WHO reference values. Iodized salt was not used by 45.7% of households. Daily bread consumption was five slices by boys and four slices by girls. Weekly milk consumption was 3 liters by boys and 2 liters by girls. Seafish was consumed once monthly. From these figures we calculated a mean daily iodine intake of 171 microg in boys and 143 microg in girls, in good agreement with the measured median urinary concentration of 16.7 microg/dl in boys and 14.5 microg/dl in girls. The sex difference in iodine excretion is fully accounted for by an extra daily consumption of one slice of bread (20 microg I) and one-seventh of a liter of milk (8.3 microg I) by boys. Thyroid volume increases with age, but a steep increase by 41% was observed in girls between 11 and 12 years, and by 55% in boys between 13 and 14 years, coinciding with peak height velocity. Girls have a larger thyroid volume at the ages of 12 and 13 years, but thyroid volume is larger in boys as of the age of 14 years. CONCLUSIONS: (1) Iodine deficiency disorders no longer exist in The Netherlands. (2) Bread consumption remains the main source of dietary iodine in The Netherlands; the contribution of iodized table salt and seafish is limited. (3) The earlier onset of puberty in girls renders their thyroid volume larger than in boys at the age of 12--13 years, but boys have a larger thyroid volume as of the age of 14 years.

Adolescent↗
PubMed1991

Reference values of immunoglobulin E in umbilical cord sera.

The National Program for the Prevention of Allergic Diseases, including the determination of IgE concentrations in umbilical cord serum at birth began in 1986. Research was conducted to determine normal umbilical cord serum values in Cuban children since no previous research had been performed. The values consulted corresponded to children from other countries with different characteristics from ours. A total of 900 neonates were examined, excluding those whose mothers had been affected by factors that increase serum IgE concentrations. IgE values higher than 10 IU/ml were also regarded as abnormal. The microELISA-IgE technique, a heterogenous immunoenzymatic sandwich type assay, was used. As reference values, a 0.64 mean, 0.06 lower limit and a 6.83 upper limit were obtained.

Cuba↗
PubMedDate not supplied

[Platelet reference values in healthy children living in Mexico City].

INTRODUCTION: There are few studies on normal values of platelet parameters (number of plate-lets, mean platelet volume [MPV], thrombocytocrit, and platelet distribution width [PDW]) in children. The objective of this study was to determine the normal values of these platelet indices in healthy children who live in Mexico City, located 2240 meters above sea level. MATERIAL AND METHODS: 642 healthy children, between 2 and 16 years old, who had normal growth and developmental features and no history of treatment with drugs that alter platelets, were selected. The children fasted for 12 hours before their blood was collected by venipuncture of the arm. Platelet values, determined in an automatic counter (Cell Dyn 3000), were used in the statistical analysis to calculate the mean, standard deviation, and the 3, 50, and 97 percentiles of each data distribution, stratified by age and sex. Correlations between platelet count, MPV, PcT, and PDW, according to age and sex, were evaluated with linear regression statistics. RESULTS: The number of platelets presented a negative correlation with age (r = -0.31, p = 0.001), whereas the mean platelet volume showed a positive correlation (r = 0.29, p = 0.001). The platelet distribution width correlated positively (r = 0.13, p = 0.001) and thrombocytocrit, negatively (r = -0.08, p = 0.05), with no evident variation in relation to age or sex. CONCLUSIONS: The decrease of platelet number with the subsequent increase of mean platelet volume in relation to age possibly resulted from the platelets having become more efficient in carrying out their haemostatic function. The values of platelet indices obtained in this study were similar to those of children living at sea level and, therefore, may be used as reference values in pediatric patients with clinical problems related to these cells.

Adolescent↗
PubMed2004

Plasma chemistry reference values from captive red-legged partridges (Alectoris rufa).

1. Haematological and plasma biochemical parameters of 66 captive red-legged partridges (Alectoris rufa) of both sexes were analysed in order to determine reference values, taking sex and age into account. 2. There were no statistically significant differences in haematocrit, plasma glucose content or creatine kinase activity either with age or between sexes. 3. Plasma cholesterol concentrations showed differences between sexes, whereas the plasma concentrations of urea, uric acid and creatinine were significantly affected by age. 4. Plasma triglyceride and total protein concentrations were affected by both sex and age. 5. A peak at 6 months old in those parameters related to protein metabolism, such as urea, uric acid and creatinine may be related to the end of the growing period and the start of ovulation after moulting.

Aging↗
PubMedDate not supplied

[Reproducibility of spirometry in Mexican workers and international reference values].

OBJECTIVE: To describe spirometric function and adjustment to foreign prediction equations in Mexican workers claiming work related disability. MATERIAL AND METHODS: We reviewed 5771 spirometries done at the Mexican National Institute of Respiratory Diseases performed with equipment and methods proposed by the American Thoracic Society. With the spirometries we generated multiple regression equations separated for men and women based on age and height, compared to other in common use reported by Knudson and Hankinson in North America and by Quanjer in europeans. RESULTS: 80% of the tests were reproducible for FVC and FEV1 according to ATS, whereas 10% were reproducible for neither. Mean FVC in men was 12% above values reported by Quanjer, 22% above Knudson, 3% above Hankinson and 6% above Rodriguez-Reynaga, whereas similar values for women were 18%, 10%, 0% and 1%. Excluding obese and those who had less than 2 acceptable maneuvers, the numbers increase by 1-2%. FEV1 was also above predicted. CONCLUSIONS: Most workers requesting disability are able to generate a reproducible spirometry. However for the same gender, age and height, workers had a FEV1 and a FVC above normal values reported by Knudson and Quanjer and are more similar to those reported by Hankinson in Mexican-Americans. While a set of appropriate reference values are obtained, regression equations obtained from the studied group will generate less error in the evaluation of disability in mexican workers. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Age Factors↗