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PubMedDate not supplied

Lymphocyte subpopulations in pediatric age. Definition of reference values by flow cytometry.

In the present paper we have analyzed the age-related changes in the distribution and numbers per cubic millimeter of the circulating lymphocyte subpopulations. Lymphocyte subsets have been examined by monoclonal antibodies specific for surface antigens (namely CD2, CD3, CD4, CD8, CD16, CD20 and CD57) and flow cytometry in lysed peripheral blood of normal neonates (1-3 days old), 1-6 month, 7-12 month, 1-2 year old babies and 3-5 year, 6-10 year old children and young people up to 17 years of age. The results confirm the lymphocytosis at birth and at later stages of life and indicate that major changes in the distribution of lymphocyte subsets occur during the first two years of life; namely we have observed sharp increase of circulating B lymphocytes and prevalence of CD4+ T lymphocytes with high CD4/CD8 ratios in babies up to two years of age, compared to the values observed in normal adults. Very few CD8+ CD57+ lymphocytes were present at birth; cells bearing this phenotype appeared later in life. Lymphocytes expressing the CD16 antigen were already present in newborns. The authors discuss the functional meanings of the age-related changes observed in the distribution and in the numbers of circulating lymphocytes. The presented data represent valuable normal ranges of lymphocyte subsets to compare with values observed in sick babies or children.

Adolescent↗
PubMed1997

[Ultrasound biometry of the fetal lung--measurement planes and reference values].

The aim of the study is to present biometrical data of the fetal lung measured in real-time sonography in mid-pregnancy. In 313 healthy fetuses of singleton pregnancies between the 15th and 30th week of gestation the fetal lung was measured in the horizontal, sagittal and frontal cross-sectional planes. In each plane the lung was measured in the following levels: clavicula, heart at the atrioventricular level (four chamber view) and diaphragm, as well as the lung length. During observation time all parameters showed a significant linear increase (r2 > 0.9; p < 0.001). Furthermore we found a high correlation between the same lung measurements collected in the different planes. The intraobserver variability was 3-8%. Such references of different planes could be helpful for differentiation of a small (hypoplasia) or a large lung (malformation).

Female↗
PubMedDate not supplied

[Reference values of urinary delta-aminolevulinic acid in children].

Delta-aminolaevulinic acid is well known to be an intermediate in the synthesis of haeme and small amounts are normally excreted in urine (ALA-U). An increased excretion of this substance occurs in porphyria and in lead poisoning. The urine specimens of 670 children (362 boys and 308 girls), aging from less than one to fifteen years and who had no evidence of abnormal exposure to lead, have been collected in order to find out the range of normal values of ALA-U expressed in mg/l for the different age and sex group. Our data can be usefull, together with zincprotoporphyrin (ZPP), for screening of anemias and for monitoring lead exposure.

Adolescent↗
PubMed1997

Age-related reference values for activation markers of the coagulation and fibrinolytic systems in children.

The physiology of the hemostatic system in infancy and childhood is different from that in adulthood. Despite differences in several components of the coagulation and fibrinolytic systems, there is no evidence that children are at greater risk for hemorrhagic or thrombotic problems compared with adults (1,2). Advances in understanding of the biochemistry of the hemostatic mechanism have led to the development of sensitive immunochemical methods for measuring peptides or enzyme-inhibitor complexes that are liberated with the activation of the coagulation and fibrinolytic systems in vivo (3). Activation markers of coagulation and fibrinolysis have been measured in newborns, infants and children with a variety of underlying disorders (4-16). However, reference ranges for children of different age groups have hitherto not been established. The aim of the present study was to document thrombin-antithrombin III-complex (TAT), prothrombin fragment 1 + 2 (F1 + 2), plasmin-alpha 2-antiplasmin-complex (PAP) and D-dimer in healthy children and to determine whether age-related differences can be demonstrated.

Adolescent↗
PubMed1993

Reference values for 24-hour non-invasive ambulatory blood pressure: a population study of men aged fifty.

All 50-year-old men (N = 126) living in a defined neighbourhood were invited to undergo 24-hour ambulatory, non-invasive blood pressure (BP) monitoring. The participation rate was 90%. Seven per cent of the subjects were taking antihypertensive drugs and 19% had a current diagnosis of hypertension or had been so diagnosed sometime previously. The 5th, 50th, and 95th percentiles of the subjects' ambulatory BP are presented. On average, daytime, night-time, and 24-hour ambulatory BP were 135/86, 114/68, 128/80 mmHg, respectively, and the average casual BP was 137/86 mmHg. The ambulatory BP in the present study was higher than in previous reference studies. No attempt was made to select the stratified subjects according to casual BP or any other medical or social variable. This and a high participation rate probably account for the difference in ambulatory BP vis-à-vis those found in other reference studies.

Age Factors↗
PubMed1994

[Echocardiography online quantification of left and right ventricular function by automatic boundary detection: reference values and reproducibility in healthy probands].

UNLABELLED: Automated border detection (ABD) is a new on-line technique that instantaneously calculates cavity areas from automatic tracking of the endocardial-blood interface with a modified ultrasonic integrated backscatter imaging system. After validation of this new method in comparison with off-line echocardiographic, Doppler- and angiographic analyses, we studied dynamic systolic and diastolic function of the left (LV) and right ventricle (RV) in 50 normal volunteers (31 +/- 9 years) in order to establish ranges of normality for the ABD-parameter. The averaged areas of the LV (apical chamber view) were 25.7 +/- 4.9 sq cm in end-diastole and 14.7 +/- 3.3 sq cm in end-systole, resulting in a fractional area change (FAC) of 43.2 +/- 4.8%. The peak filling (PFR) and peak ejection rate (PER) were 69.3 +/- 11.2 and -61.5 +/- 11.1 sq cm/s. Normalization for end-diastolic area (EDA) yielded 2.7 +/- 0.28 and -2.4 +/- 0.42 EDA/s. The areas of the RV (apical chamber view) were 17.1 +/- 3.8 sq cm in end-diastole and 9.0 +/- 2.0 sq cm in end-systole, resulting in a FAC of 47.3 +/- 9.2%. PFR and PER were 58.2 +/- 13.7 and -51.6 +/- 10.1 sq cm/s. Normalization for EDA yielded 3.4 +/- 0.74 and -2.9 +/- 0.62 EDA/s. The interobserver- and day-to-day-variability for all measured values was less than 10%. CONCLUSION: ABD permits reproducible on-line quantification of systolic and diastolic ventricular function and offers a non-invasive approach for longitudinal monitoring of cardiac patients.

Adult↗
PubMed2006

[References values for the fetal nasal bone in the first trimenon of pregnancy in a normal collective. A prospective study].

BACKGROUND: Examination of the fetal nasal bone by ultrasound between 11 and 14 weeks gestation has been proposed as an additional tool in the detection of trisomy 21. However, the variability in the identification and the normal length of the fetal nasal bone have not been investigated sufficiently as yet. The aim of this study was to evaluate this parameter and to establish normal ranges for nasal bone length. METHOD: Ultrasound examinations were carried out in 122 fetuses at 9, 10, 11, 12 and 20 weeks gestation. On the scans, the fetal profile was examined for the possibility of identification of the nasal bone. Normal nasal bone length reference ranges were generated using prenatal measurements. RESULTS: The fetal profile was successfully examined in all cases. The nasal bone could first be visualised at 9 weeks gestation. The identification of the fetal nasal bone in all cases was achieved at 12 weeks gestation. The median nasal bone length was 0.29 mm at 9 weeks gestation, 0.96 mm at 10 weeks gestation, 1.73 mm at 11 weeks gestation, 2.25 at 12 weeks gestation, and 6.18 mm at 20 weeks gestation. CONCLUSION: The reference ranges for the measurement of the fetal nasal bone length are similar to the findings in the published literature. Only with a knowledge of reference ranges for nasal bone length in normal fetuses can conclusions be drawn about the presence/absence of the bone or the presence of a hypoplastic nasal bone. Further studies are necessary to confirm these results and to obtain larger datasets to assess nasal bone as a quantitative marker.

Anthropometry↗
PubMed1997

Clinical evaluation of the Byk LIA-mat CA125 II assay: discussion of a reference value.

The Byk LIA-mat CA125 II assay was compared with the Centocor IRMA CA125 II. Serum samples studied (n = 1012) were obtained from 652 apparently healthy females, 61 pregnant women, and 299 patients with benign and malignant gynecological tumors. The CA125 II assay value at the 95th percentile of the total healthy group was 29 kU/L for the LIA-mat and 32 kU/L for the Centocor assay. For the LIA-mat assay the 95th percentile was 31 kU/L (Centocor 36 kU/L) for the group < 45 years and 21 kU/L (Centocor 25 kU/L) for women > 55 years of age. By using ROC curves we found the optimal pretreatment Byk LIA-mat CA125 II value differentiating between benign and malignant ovarian tumors to be 95 kU/L. Pretreatment CA125 values > 1000 kU/L were detected in serum samples of patients with advanced epithelial ovarian cancer.

Adolescent↗
PubMed1996

[A table of reference values for cost-benefit-analyses in health care].

On the basis of preference measurements in several countries a table has been prepared showing society's assessment of different outcomes in health care as a function of severity of illness and effect of treatment. The numbers in the table can be used in cost-effectiveness analysis as an aid to deciding allocation of resources.

Cost-Benefit Analysis↗
PubMed1985

[Correlation between the assay of glycosylated hemoglobin A1c and fructosamine in diabetic patients submitted to a systematic control visit. Establishment of reference values].

The plasmatic glycosyl proteins levels were measured in fifty non diabetic volunteers and thirty five patients with diabetes mellitus by the fructosamine test. The upper limit for healthy volunteers was estimated to 25 mumoles/g protein. A higher fructosamine concentration and greater spread of values were observed in the diabetic group. A very good correlation was noted in the diabetic group between A1C hemoglobin and fructosamine concentrations. This test is very reproducible, inexpensive and should be a good alternative to the A1C hemoglobin determination in some physiologic or pathologic disorders.

Diabetes Mellitus, Type 1↗
PubMed1987

Reference values for pulsed Doppler signals from the blood flow on both sides of the aortic valve.

Pulsed Doppler signals were recorded in 215 healthy subjects, 120 males and 95 females, between 1 and 65 years of age. The measurements were performed in the left ventricular outflow tract (LVOT) and in the ascending aorta (AAO). Amplitude spectra from the Doppler signals were stored in digital form together with adjustment data for the instrument, the simultaneously registered ECG and respiration signal. The maximum velocity (Vmax), the maximum acceleration (Amax) and the width of the velocity distribution around Vmax (width) were derived from these spectra and used for the characterization of the signals. These parameters were computed without observer interaction using a computer program. Effects of age, sex, body surface area, heart rate and respiration were studied. Reference ranges were calculated. The following conclusions can be drawn: Vmax and Amax in the AAO decrease clearly with increasing age from approximately 100 to 60 cm s-1 and from 2000 to 1000 cm s-2 (medians), respectively. The variation of the width in the AAO is greater for people over 45 years. Vmax, Amax and width in the LVOT increase slightly with advancing age from approximately 60 to 80 cm s-1, 800 to 1000 cm s-2 and 12 to 15 cm s-1 (medians), respectively. These parameters of flow were either unrelated or only weakly related to other physiological variables in this study group.

Adolescent↗
PubMed1987

Analysis, storage stability and reference values for urinary chromium and nickel.

Simple direct dilution methods are described for the analysis of urinary chromium and nickel with electrothermal atomic absorption spectrometry. The day-to-day variation of the methods is in the order of 5%, and the detection limits 20 and 0.1 nmol/l (1.2 and 0.0052 micrograms/l) for urinary nickel and chromium, respectively. At levels corresponding to occupational exposures, both metals are stable (within 20%) in urine specimens in the refrigerator for the least ten months. The stability does not require acidification. Geometric mean values for urinary nickel and chromium in the non exposed population in Finland (n = 299 and 155) are 70 and 1.5 nmol/l (4.8 and 0.078 micrograms/l), and the upper 95% confidence limits from a log-normal distribution, are 170 and 11 nmol/l (10 and 0.57 micrograms/l), respectively.

Chromium↗
PubMed2002

Clinical applications of arterial stiffness; definitions and reference values.

Arterial stiffening is the most important cause of increasing systolic and pulse pressure, and for decreasing diastolic pressure beyond 40 years of age. Stiffening affects predominantly the aorta and proximal elastic arteries, and to a lesser degree the peripheral muscular arteries. While conceptually a Windkessel model is the simplest way to visualize the cushioning function of arteries, this is not useful clinically under changing conditions when effects of wave reflection become prominent. Many measures have been applied to quantify stiffness, but all are approximations only, on account of the nonhomogeneous structure of the arterial wall, its variability in different locations, at different levels of distending pressure, and with changes in smooth muscle tone. This article summarizes the methods and indices used to estimate arterial stiffness, and provides values from a survey of the literature, followed by recommendations of an international group of workers in the field who attended the First Consensus Conference on Arterial Stiffness, which was held in Paris during 2000, under the chairmanship of M.E. Safar and E.D. Frohlich.

Arteries↗
PubMedDate not supplied

[Reference values of the ferritin concentration in the serum in children].

Concentrations of ferritin were determined using the luminescence enhanced enzyme immunoassay method in serum of 272 (male = 148, female = 124) "healthy" children. The ferritin concentration in children is age dependent. The newborn values (140.1-673.8 micrograms/l, 95% confidence interval) decrease until the end of the first year and stabilize thereafter in a sex specific fashion: male means = 31.90 micrograms/l (95% confidence interval: 14.0-72.2 micrograms/l), female means = 39.23 micrograms/l (95% confidence interval: 16.1-79.9 micrograms/l).

Adolescent↗
PubMedDate not supplied

Reference values for serial vestibular testing.

This study defines the normal limits of day-to-day variation in vestibular function. A short-acting caloric test was used and nystagmus intensity was measured by means of an interactive computerized technique. Data were analyzed from 30 normal subjects tested on three successive days and from ten of these subjects who were also tested on 11 additional occasions. Individual caloric test scores generally remained between 55% and 170% of their initial value; narrower ranges resulted when scores were averaged together. There was very little habituation of caloric responses. The upper normal limits of test-retest variation in scores for right-left difference and directional preponderance of caloric responses were 24% and 22%, respectively.

Caloric Tests↗
PubMed1979

[Reference values of the residual volume for the rvo2-method (author's transl)].

Residual volume and the relative RV/TLC (total lung capacity) were measured in 632 men and 191 women aged 15 to 70 years. The residual volume showed a significant correlation to age and body height, but not to the relative body weight (Broca-Index). The values of RV/TLC showed a correlation to age and Broca-Index, but not to the body height. The regression formular to calculate the normal range are given; they comply with the data of other authors.

Adolescent↗