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PubMed2003

Ventilatory functions in Croatian population in comparison with European reference values.

AIM: To compare ventilatory capacity of Croatian population with the ventilatory function values predicted by conventional equations based on measurements among European populations. METHODS: Ventilatory capacity and respiratory symptoms were determined in a group of 2,482 healthy non-smokers (1,162 men and 1,320 women). The measurements were performed with a pneumotach spirometer. Maximum expiratory flow volume curves (MEFV) were registered, and forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and flow rates at 50% (MEF50) and the last 25% of the vital capacity (MEF25) were recorded. Anthropometric data were also noted. Reference values were calculated using multiple linear regressions. RESULTS: Comparisons of our values with the prediction summary equations issued by the European Community for Steel and Coal (ECSC) and the European Respiratory Society (ERS) showed that healthy Croatians had consistently lower values of FVC (92.1-/+14.0% of the predicted volume for men and 86.2-/+11.7% for women) and FEV1 (93.7-/+14.8% of the predicted values for men and 95.3-/+13.1% for women), but higher values of MEF50 (107.8-/+30.1% of the predicted values for men and 103.4-/+22.8% for women) and MEF25 (117.3-/+41.0% of the predicted values for men and 117.9-/+34.0% for women) than the ECSC/ERS recommendations. The comparison was also made with the most commonly used North American reference standards based on populations of European origin, with similar findings. On the basis of the results of multiple linear regressions, we constructed prediction equations for ventilatory function in Croatian population. CONCLUSION: The ECSC/ERS recommendations are not satisfactory for the Croatian population.

Adult↗

PubMed2005

Reference values for the indicators of skeletal and muscular status of healthy Polish children.

Dual-energy X-ray absorptiometry (DXA) results are affected by the growth- and maturation-based anthropometric variances during childhood and adolescence. To address this issue, anthropometric variables were implemented to normative DXA values for the total body (TB) and lumbar spine (S) data obtained from a cross-sectional sample of 562 healthy Caucasian children (278 females) aged 5 to 18 yr who were measured using a pencil-beam DXA device (DPX-L; GE Lunar). Across age or body height (BH) groups, female and male values for TB bone mineral content (TBBMC) (g), TB bone mineral density (TTBMD) (g/cm(2)), SBMC (g), SBMD (g/cm(2)), lean body mass (LBM) (g), TBBMD/LBM (g/g), and SBMC/LBM [(g/g) x 100)] were assessed and compared using ANOVA and t-tests. There was no gender difference in TBBMC until age 16 and in TBBMD until age 17; thereafter, male values were significantly higher. At 12 to 13 yr of age, female SBMD values were significantly higher than male. The BH matching revealed lack of major gender-related differences in TBBMC or TBBMD values across whole height range, whereas at heights of 150 to 175 cm, females had generally higher values of SBMC and SBMD than male counterparts. Further, the LBM values and calculated TBBMC/LBM and SBMC/LBM ratios were considered as the muscle and muscle-bone indicators, respectively. The muscle-bone relationship analysis using LBM and TBBMC/LBM and SBMC/LBM values revealed age- and BH-related differences between genders. At LBM values of 32 kg and above and ages 14 yr and above for the whole skeleton as well as 12 yr and above for spine segment, females accrued significantly more BMC for the LBM unit than males. In order to properly assess children who might be at risk for low bone mass, we provide reference values for BMC and BMD of usually studied sites, expanded by muscle-bone relationship indicators owing to reduced diagnostic errors and distinguished bone disorders.

Absorptiometry, Photon↗

PubMed2005

Assessment of reference values for polychlorinated biphenyl concentration in human blood.

A chemical factory which produced polychlorinated biphenyls (PCBs) operated in Brescia, North Italy, (about 200000 inhabitants) from the 1930s to the 1980s. High levels of PCBs were recently found in soil, food and people living in an area close to the factory. We performed a survey among the general population living in non-polluted areas of the town in order to define the reference values (RVs) of the non-exposed population. A random sample of subjects aged 20-79 years (50% males) was selected. Participants underwent PCB determination and were interviewed on their residential and occupational history and current diet. For RV determination, subjects who had resided in the polluted area or consumed any food produced in the area in their lifetime were excluded. Eight hundred and ninety-two subjects were contacted, 579 (65%) of whom agreed to participate; 311 of them were considered for RV determination (53% male, mean age=48.7 years). Total PCB serum levels, computed as the sum of the 24 congeners determined, were: mean=5.15ng/ml (SD=8.83), median=4.11ng/ml, range=0.4-34.12ng/ml, 95th centile=14.38ng/ml. Lipid-adjusted mean and median were 897 and 705ng/g lipid, respectively. PCB values showed positive correlations with age (Spearman's r=0.76) and with serum concentration of total cholesterol (r=0.40) and triglycerides (r=0.36). No association was found with gender, cigarette smoking, alcohol or diet. Seven PCB congeners, (PCB 180, 153, 138, 170, 194, 118, and 156), including those at higher chlorination, were present in more than 30% of the subjects and contributed 99% of the total PCB levels, with a modest role of dioxin-like congeners.

Adult↗

PubMed1996

Spirometry reference values for healthy elderly blacks. The Cardiovascular Health Study Research Group.

Pulmonary function was assessed by spirometry in 497 black and 2,980 white ambulatory elderly male and female participants of the Cardiovascular Health Study. The quality assurance program prompted technicians to exceed American Thoracic Society recommendations for spirometry. A "healthy" subgroup of 235 black and 1,227 white participants age 65 years and older was identified by excluding current and former smoker, and those with self-reported asthma or emphysema, congestive heart failure, and poor-quality results of spirometry tests, since those factors were associated with a lower FEV1. Reference equations and normal ranges for elderly blacks for measurements of FEV1, FVC, and the FEV1/FVC ratio were then determined from the healthy group. These elderly blacks had an FVC about 6% lower than elderly whites, even after correcting for standing height, sitting height (trunk length), and age. The popular use of spirometry reference values from studies of middle-aged white subjects by applying a 12% race correction factor for black patients appears to overestimate predicted values.

Aged↗

PubMed2006

[Detection by flow cytometry of T cell subsets secreting IL-2 and UFNy(Gamma): optimalisation for the technic and the establishment of reference values].

A dysregulation in Th1/Th2 balance has been described for different pathological situations. Knowing the cytokine profile in a given pathology could assist in understanding the disease mechanism and in choosing an immune intervention most effective for the management of this condition. In this work, the production of two Th1 cytokines, IL-2 and IFN- gamma, was analyzed for different T-cell subsets from 20 normal subjects (mean age 33.5 years) and reference values were defined using the flow cytometric analyses. The optimum operating conditions were set as following: mononuclear cells were stimulated with PMA (20 ng/ml) and ionomycin (1 uM) for 6 h in the presence of brefeldin A (10 ug/ml). Cells were fixed with 4% paraformaldehyde and then dually stained, with anti-CD3 or anti-CD4 or anti-CD8 for the membrane and with anticytokine antibody for the intracytoplasma after being permeabilized with 0.5% saponine solution. The frequency determination of cells that produce IL-2 or IFN-gamma revealed large 95% confidence intervals: (CD3-IL-2: 4.60-10.67%, CD8-IL-2: 1.47-23%, CD3-IFN-gamma: 2,97-32,49%, CD4-IFN-gamma: 2.83-21%, CD8-IFN-gamma: 4.60-35.28%). CD4+ lymphocytes produce the majority of IL-2 (85 vs 13% for CD8+). For IFN-gamma, the situation is more balanced, but the CD4+ lymphocytes remain the predominant producer cells (63 vs. 41%).

Adult↗

PubMedDate not supplied

[Flow-volume curves in healthy children and adolescents 10-19 years of age. Reference values and lower limits of the normal].

In 477 healthy children and adolescents (247 boys and 230 girls, aged 10 to 19 years), we measured the vital capacity (VC), the forced expiratory volume in one second (FEV1), the flow between 25 and 75% of expired forced vital capacity (FEF25-75) and the forced expiratory flows when 75, 50 and 25% of forced vital capacity remain to be expired (FEF75, FEF50, FEF25), in order to determine reference values and lower limits of the normal. Regression functions were calculated for girls and boys separately. The best correlations for pulmonary volumes and flows were obtained by taking into account simultaneously height and age in girls, height, age and weight in boys. Power function is the model of regression that fits our data the best. The regression functions determined, as well as the lower limits of the normal and the residual standard deviations, are given by sex for each of the variables measured. These results are discussed and compared with those in literature. They concern clinicians (identification of "abnormal" subjects) and epidemiologists (prevalence of ventilatory troubles, comparison of different populations), and can be used in adolescents of the same age groups.

Adolescent↗

PubMed1992

Reference values of the steatocrit and its modifications in diarrheal diseases.

Conflicting results have been reported on the use of the steatocrit to measure fecal fat excretion. Aiming to assess the reliability of this method and its usefulness in the diagnosis of intestinal enteropathies, we measured the steatocrit in 747 healthy children and 442 children with diarrhea grouped according to diagnosis. The steatocrit was found to correlate strictly (r = 0.93) with the chemical measurement of fecal fat. Reference values and ranges were established. The maximal steatocrit was observed in neonates; afterwards, it progressively decreased to an undetectable level in children older than 2 years of age. A steatocrit abnormally high for age was found in 20% of patients with acute diarrhea and in 53% of those with chronic diarrhea. All celiac patients with a gluten-containing diet showed a marked increase of steatocrit. We conclude that the steatocrit is a reliable and easy-to-perform test, which quickly provides valuable information in the diagnostic workup of the child with diarrhea.

Adolescent↗

PubMed2001

Reference values for plasma dipeptidyl-peptidase IV activity and their association with other laboratory parameters.

In blood, the exopeptidase dipeptidyl-peptidase IV (DPPIV; EC 3.4.14.5) is predominantly present in a soluble form in plasma/serum and as an activation antigen on the membrane of lymphocytes (CD26). It modifies some important biologically active peptides (neuropeptides, chemokines), and a regulatory role for DPPIV/CD26 in immune and endocrine processes has been demonstrated. The aim of this study was to determine reference values for plasma/serum DPPIV activity and to study the association of this activity with a series of biochemical and hematological parameters and baseline characteristics such as age, gender, blood pressure and body mass index. We studied 481 healthy subjects aged between 19 and 61 years. The group consisted of 213 men and 268 women equally divided between the different categories of age. Among the women, 127 were taking hormone therapy (contraception/hormone replacement) and 141 were not. A multiple regression model shows that DPPIV activity decreases significantly with age. The activity in women is slightly lower than in men. We observed an important association with liver, muscle and lipid metabolism-related parameters. In this model, no significant contribution of body mass index, blood pressure or hormone therapy could be stated.

Adult↗

PubMed2005

Assessment of reference values for DNA damage detected by the comet assay in human blood cell DNA.

Genotoxicity measured by the comet assay is expressed by different researchers using parameters that are not easy to conceptualize, except for percent tail DNA (%T) or visual score (arbitrary units). A total of 125 publications have reported genotoxicity as DNA damage (representing strand breaks, alkaline labile sites, and transient repair sites), endonuclease III (ENDOIII), or formamidopyrimidine DNA glycosylase (FPG) sensitive sites. I have recalculated the visual score so that it is expressed in the range of 0-100, similar to that of %T. Similar values were obtained for DNA damage and ENDOIII sites, regardless of whether of the data were reported as %T or visual score. Thus, these endpoints can be used interchangeably, assuming that the visual score is expressed in the 0-100 range. Pooled analysis of %T and visual score data showed that the median (25-75%) values of DNA damage, ENDOIII, and FPG sites were 8.6 (4.4-14.5), 11.0 (4.2-19.5), 7.6 (3.2-14.2), respectively. The duration of alkaline treatment and electrophoresis had no significant effect on the level of DNA damage. There was a positive correlation between age and the level of DNA damage. A sub-analysis of DNA damage obtained from European countries showed a negative correlation with latitude. In conclusion, reference values for DNA lesions measured by the comet assay are around 7-11 %T or arbitrary units.

Age Distribution↗

PubMed1987

[Reference values of serum transferrin in newborn infants, children and adults].

The authors have studied the evolution of serum transferrin concentration in relation with age (newborn child, infant, adult). The mean concentration of serum transferrin is the lowest for neonates (2.15 g/l). At 10 months, it increases to reach a value of about 3.10 g/l then reduces at 24 (3.0 g/l) and 48 months (2.8 g/l). By the 4 to 18 years subjects, serum transferrin is approaching that of 10 months children (3.15 g/l). At last it doesn't support any modification during all the adult life. The diversity of the obtained results dependent of the used technique and/or of the laboratory, justifies that each one defines his own reference values.

Adolescent↗

PubMed1977

Equine cerebrospinal fluid: reference values of normal horses.

Cerebrospinal fluid (CSF) samples were collected from the atlanto-occipital (AO) and lumbosacral (LS) subarachnoid spaces of 24 horses and 21 ponies that had no clinical evidence of neurologic disease. Depth of needle insertion, pressures, refractive index, rapid reagent strip test (protein, glucose, blood, pH) results, cell counts, content of protein, glucose, sodium, potassium, chloride, calcium, phosphorus, urea nitrogen, and cholesterol, and activities of creatine phosphokinase, aspartate transaminase, lactic dehydrogenase, and alkaline phosphatase were determined. The resulting clinical reference values obtained were discussed in light of the published normal values for CSF from horses, other animals, and man. White cell counts in CSF were found to be from 0 to 6/microliters. Values for protein content were distributed between wider limits than previously reported values. The LS-AO difference is proposed as a criterion for clinical evaluation of CSF protein content. Ponies were found to have more protein in their CSF than did the horses, and CSF from the LS site contained more glucose than that from the AO site. The CSF electrolyte composition was similar to that of previous reports. Enzyme activities in equine CSF are reported for the 1st time.

Animals↗

PubMed1998

Study on urine boron reference values of Japanese men: use of confidence intervals as an indicator of exposure to boron compounds.

A simple and rapid method for the determination of urine boron by inductively-coupled plasma argon emission spectrometry (ICPAES) has been developed to establish boron exposure guidelines. After 11-fold dilution in 18.25 M omega cm ultra-pure water and vigorous shaking, urine may be directly injected into the spectrometer, providing accurate and reproducible results. We report the results obtained with urine samples obtained from a group of male Japanese electronic workers (n = 102) who had not been exposed to boron; boron concentrations were corrected with use of a specific gravity of 1.024 g/ml. The frequency distribution resulted in a log-normal distribution diagram for anatomical spread. The geometric mean values for urine boron in the non-exposed workers was 798.0 micrograms/l, while the confidence interval (C.I.) was between 398.1 and 1599.6 micrograms/l. Taking into consideration the short biological half-life of boron and its major excretion route via urine, urine was considered to be a suitable means for monitoring of exposure to this element. We conclude that the guidelines established by determining boron reference values are useful for the protection of individuals exposed to boron in their working environments.

Adult↗

PubMed1996

Environmental and urinary reference values as markers of exposure to hydrocarbons in urban areas.

A study using individual dosimetry to evaluate the daily inhaled dose of sixteen aromatic and aliphatic hydrocarbons in three groups of primary school children, living in three Italian towns with 50,000 inhabitants or less, (Treviglio-Lombardy; Poggibonsi-Tuscany; Valenza-Piedmont) is presented. The simultaneous use of two passive samplers (radial diffusion) for each child, for a 24 h period, determined both the indoor and indoor + outdoor environmental reference concentrations. We measured the urinary levels of benzene, toluene, ethylbenzene and xylenes for each child and hence determined the urinary reference values for BTEX. We also considered the possibility of using benzene in urine as a biomarker of environmental exposure of the general population to this xenobiotic. We evaluated how both the environmental and biological measures were influenced by the presence of smokers in the surveyed children's houses. For the group of children living in Poggibonsi, we considered the influence of the living area and the traffic density on environmental concentrations of benzene (indoor and indoor + outdoor).

Air Pollutants↗

PubMed1984

Freeze/thaw stability of transferrin, and reference values obtained with kinetic nephelometry.

To determine whether transferrin is stable to repeated freezing and thawing, we used blood specimens from 100 normal adults. Their transferrin concentrations were determined by a laser kinetic nephelometric immunoassay. The sera were stored at 4 degrees C and analyzed the next day (day 1). Specimens 1-25 were stored at -20 degrees C and assayed again on days 3, 4, 8, 16, 22, and 43. Specimens 26-100 were stored at 4 degrees C and analyzed again on day 2. Transferrin proved to be stable to repeated freezing and thawing. Normal reference values with respect to sex and age are given, as determined with the Baker 420 Immunological Nephelometer.

Adult↗

PubMed1991

Modified enzyme-based colorimetric assay of urinary and plasma oxalate with improved sensitivity and no ascorbate interference: reference values and sample handling procedures.

The measurement of oxalate in urine and plasma continues to be difficult, particularly in the presence of ascorbate. We have modified and validated a colorimetric assay involving the use of oxalate oxidase (EC 1.2.3.4). Modification of an HPLC spectrophotometric detector improved sensitivity (to as much as 1000-fold that of conventional spectrophotometers) and allowed measurement of oxalate concentrations less than 1 mumol/L. This provided more than enough sensitivity for measurement of normal concentrations of plasma oxalate. We established reference values for oxalate concentrations in urine and plasma, studied sample handling, and established conditions to avoid ascorbate interference in urine and plasma measurements. Mean analytical recovery of [14C]oxalate from plasma to the filtrate was 86 (SD 10)%; recovery of unlabeled oxalate from filtrate was 87 (SD 9)%. Urinary oxalate excretion rates in apparently healthy controls were 0.11-0.46 mmol/24 h. Plasma concentrations in control subjects were 2.5 (SD 0.7) mumol/L, similar to concentrations determined by recent gas chromatographic and isotope dilution methods. Frozen and acidified urine samples showed no interference from ascorbate when excess ascorbate was avoided. Ingestion of 2 g of ascorbate daily did not increase urinary oxalate in healthy control subjects, but during storage ascorbate was converted to oxalate in all conditions tested.

Adult↗

PubMed1998

Midtrimester maternal serum free beta-human chorionic gonadotropin levels: normal reference values for Taiwanese women.

BACKGROUND: The purpose of this study was to establish normative median values for maternal serum free beta-human chorionic gonadotropin (beta-hCG) during the second trimester of pregnant Taiwanese women. MATERIALS AND METHODS: We collected the data of midtrimester serum free beta-hCG concentration levels from 15,132 normal Taiwanese singleton pregnancies between 14 and 22 weeks' gestation. The maternal age on the day of delivery and maternal weight at the time of sampling were recorded in all cases. The relationship between gestational days and multiple of the median (MoM) levels of serum markers was analyzed using nonlinear regression methods. RESULTS: The median values of free beta-hCG in pregnant Taiwanese women were higher than those of pregnant white women. The log10 standard deviation distribution of free beta-hCG MoM values in the study population was 0.275 with a log10 mean of 0.0097. There were 1.81% of pregnancies with free beta-hCG levels less than 0.3 MoM and 11.33% with levels less than 0.5 MoM; 12.91% had serum levels greater than 2.0 MoM and 5.29% had serum levels greater than 3.0 MoM. CONCLUSION: Because of differences in race and methodology, any laboratory intended to provide determination of free beta-hCG for Down syndrome screening should establish its own normal reference values.

Adolescent↗

PubMed1990

Reference values for circadian rhythms of 98 variables in clinically healthy men in the fifth decade of life.

Nine clinically healthy men, 41-47 yr of age, served as subjects in a 24-hr study conducted at the Edward Hines Jr Veterans Administration Hospital in the Chicago area in May 1988. Physiologic measurements, and blood and urine samples were collected at 3-hr intervals over a single 24-hr period beginning at 1900. The number of variables measured or calculated (total = 98) included: 6 vital signs (oral temperature, pulse, blood- and intraocular pressures); 16 in whole blood (counts and differentials); 50 in serum (SMAC-24, lipids, hormones, electrophoresis of LDH and proteins); and 26 in urine (solids, proteins, creatinine, catecholamines, melatonin, cortisol, electrolytes and metals). Data were analyzed for time effect by analysis of variance (ANOVA) and for circadian rhythm by single cosinor. Individual rhythm characteristics for each variable were summarized for the group by population mean cosinor. The vast majority of variables revealed statistically significant within-day changes in values as validated by one-way ANOVA. All vital signs (except for intraocular pressures) and all serum hormones displayed a prominent circadian rhythm for the group, as did most variables in whole blood, while only about half of the variables in urine demonstrated a significant group rhythm. The results obtained are meant to: (a) document the circadian time structure; and (b) serve as reference values for circadian rhythm characteristics (range of change, mesor, amplitude and acrophase) for a defined group of individuals: clinically-healthy adult men in the prime of life.

Adult↗

PubMed2005

Microplate ELISA for urine microalbumin: reference values and results in patients with type 2 diabetes and cardiovascular disease.

An ELISA for urine microalbumin using microtiter plates has been developed. The assay uses polyclonal anti-human albumin antibody for coating the microtiter plates and the same antibody conjugated with horseradish peroxidase for detection. The assay sensitivity is 1.6 microg/ml. Results by this in-house ELISA show good correlation (r = 0.99) with those obtained by a commercial assay using the Behring BNII autoanalyzer. Within-day and between-day CVs are 10%. Reference values for microalbumin in 769 urine specimens from healthy Chinese subjects were higher in women than men and higher in subjects 50 yr than in those <50 yr of age. Elevated mean concentrations of urine microalbumin were observed in patients with type 2 diabetes and CVD. This in-house ELISA is simple, sensitive, precise, and especially suited for laboratories without expensive autoanalyzers.

Albumins↗