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PubMed1994

[Reference values of laboratory tests in elderly subjects--blood pressure].

The upper limits of normal blood pressure have been considered to be 139 mmHg systolic and 89 mmHg diastolic for adults, but these values are not necessarily applicable to the elderly. This report presents blood pressure values of healthy persons aged 65 to 94 and estimates the upper limits of normal blood pressure in the elderly based on follow-up studies. The Blood Pressure Subgroup of the Study on Reference Values of Laboratory Tests in Elderly Subjects defined inclusion criteria for the healthy elderly as follows: (1) persons aged 65 to 94, (2) persons not complicated with cardiovascular diseases, (3) persons capable of living and walking freely, (4) persons without dementia, (5) persons without anemia, liver disease, renal failure, diabetes mellitus on drug treatment, lung disease, valvular disease or marked arrhythmias, (6) persons without neuromotor disease. The subgroup collected 2008 persons who fulfilled the criteria. Of the 2008 persons, 663 were not taking antihypertensive drugs, had body weight within an average Body Mass Index +/- standard deviation and had no abnormalities on ECG. The 663 persons were considered to be a group of most the normal elderly. Blood pressure values in this group were 133.3 +/- 18.9/77.0 +/- 10.6 mmHg for males (N = 318) and 134.3 +/- 18.7/75.7 +/- 10.2 mmHg for females (N = 345). Follow-up studies carried out by some members of the Blood Pressure Subgroup suggested that the upper limits of the normal blood pressure were 140 to 159 mmHg systolic and 80 to 89 mmHg diastolic for the elderly.

Adult↗

PubMed1999

[The calculated reference value of the tubular extraction rate in infants and children: an attempt to use a new regression equation].

This study was designed to investigate the empirical tubular extraction rate (TER) of the normal renal function in childhood and then propose a new equation to obtain TER theoretically. The empirical TER was calculated using Russell's method for determination of single-sample plasma clearance and 99mTc-MAG3 in 40 patients with renal disease younger than 10 years of age who were classified as having normal renal function using diagnostic criteria defined by the Paediatric Task Group of EANM. First, we investigated the relationships of the empirical value of absolute TER to age, body weight, body surface area (BSA) and distribution volume. Next we investigated the relationships of the empirical value of BSA corrected TER to age, body weight, BSA and distribution volume. Linear relationship was indicated between the absolute TER and each body dimensional factors, especially regarding to BSA, its correlation coefficient was 0.90 (p value). The BSA-corrected TER showed a logarithmic relationship with BSA, but linear regression did not show any significant correlation. Therefore, it was thought that the normal value of TER could be calculated theoretically using the body surface area, and here we proposed the following linear regression equation: Theoretical TER (ml/min/1.73 m2) = (-39.8 + 257.2 x BSA)/BSA/1.73 The theoretical TER could be one of the reference values of the renal function in the period of the renal maturation.

Body Surface Area↗

PubMed1989

[Immunologic findings in the newborn infant. II. Studies of humoral immunity, reference values of immunologic studies in the newborn infant].

After dealing with cellular immune aspects in the first part of the paper the authors describe in the second part the state of humoral immunity in healthy full-term newborns aged one to three days. The number of complementreceptor lymphocytes was 17.0 +/- 8.9% or 0.75 +/- 0.51 (mean +/- S.D.) respectively, with the EAC-rosette method. The percentage value equalled that of adults but the absolute count is higher. Using the immunodiffusion method IgA was detectable in 4 out of 132 newborns only 8.86 +/- 2.52 g/l (mean +/- S.D.) was measured as an average IgG concentration. With regard to the IgM content the values often exceeded 0.30 g/l in newborns of mothers who had been suffering from pre-eclampsia. Their mean value of 0.35 +/- 0.21 g/l, too, was significantly higher than 0.13 +/- 0.08 in the resting infants. Raised IgM values frequently coincided with high spontaneous transformation activities in lymphocyte cultures. The possible causes are discussed. Complement C3-component was measured on average with 0.78 +/- 0.18 g/l and C4-component with 0.34 +/- 0.11 g/l. When calculating reference values for newborns the results of infants with maternal pre-eclampsia have been omitted.

Complement C3↗

PubMed1999

Sniff nasal inspiratory pressure. Reference values in Caucasian children.

Like in adults, normal values of maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) span a large range in children, making interpretation of low values difficult. Recently, sniff nasal inspiratory pressure (Pnsn) was developed as a new noninvasive test of inspiratory muscle strength. In healthy adults, Pnsn is most often higher than PImax. The aim of this study was to establish reference values of Pnsn in children and to compare them with PImax. A group of 180 unselected healthy children age 6 to 17 yr was studied in a school setting. All had a forced vital capacity (FVC) > 80% of predicted and a ratio of forced expiratory volume in one second/forced vital capacity (FEV1/ FVC) > 85% of predicted. All maneuvers were performed in the sitting position. The Pnsn was measured using a catheter occluding one nostril during maximal sniffs performed through the contralateral nostril from FRC. The PImax was measured from FRC and residual volume, and PEmax from FRC and total lung capacity. All children were able to perform the Pnsn maneuver easily. Pnsn was 104 +/- 26 cm H2O in boys and 93 +/- 23 cm H2O in girls (p < 0.005). These values were similar to those previously measured in healthy adults. Pnsn correlated with age, weight, and height in boys, but not in girls. In both sexes, Pnsn was higher than PImax measured at the same lung volume (FRC) (p < 0. 0001). Pnsn was >= PImaxFRC in 73 of 93 boys and 79 of 87 girls. We conclude that Pnsn can be easily used to assess inspiratory muscle strength in children age 6 yr or more, providing values higher than PImax. Normal values are independent of age in girls, and can be predicted from age by a first-degree equation in boys. Being easy and noninvasive, Pnsn may prove useful to assess inspiratory muscle strength in children with neuromuscular disorders.

Adolescent↗

PubMed1999

Reference values for lung function tests. II. Maximal respiratory pressures and voluntary ventilation.

The strength of the respiratory muscles can be evaluated from static measurements (maximal inspiratory and expiratory pressures, MIP and MEP) or inferred from dynamic maneuvers (maximal voluntary ventilation, MVV). Although these data could be suitable for a number of clinical and research applications, no previous studies have provided reference values for such tests using a healthy, randomly selected sample of the adult Brazilian population. With this main purpose, we prospectively evaluated 100 non-smoking subjects (50 males and 50 females), 20 to 80 years old, selected from more than 8,000 individuals. Gender-specific linear prediction equations for MIP, MEP and MVV were developed by multiple regression analysis: age and, secondarily, anthropometric measurements explained up to 56% of the variability of the dependent variables. The most cited previous studies using either Caucasian or non-Caucasian samples systematically underestimated the observed values of MIP (P < 0.05). Interestingly, the self-reported level of regular physical activity and maximum aerobic power correlates strongly with both respiratory and peripheral muscular strength (knee extensor peak torque) (P < 0.01). Our results, therefore, provide a new frame of reference to evaluate the normalcy of some useful indexes of respiratory muscle strength in Brazilian males and females aged 20 to 80.

Adult↗

PubMed1986

[Noninvasive study of intracerebral circulation in premature and newborn infants with pulsed Doppler sonography. Principles, measuring technics, reference values].

This paper describes our method to evaluate neonatal cerebral circulation in a semiquantitative way by transfontanellar pulsed Doppler ultrasonography. We defined three arterial (internal carotid, basilar, and anterior cerebral artery) and three venous (internal cerebral and internal jugular vein; sinus rectus) sites for measurement of peak systolic, end diastolic, and mean velocity. Reference values, intraindividual and interindividual variation are calculated for infants between 750 and 4000 g body weight. Among all possible measurements follow up of mean velocity of the internal carotid artery in an individual infant is most reliable.

Birth Weight↗

PubMedDate not supplied

Metanalytical assessment of reference values for polychlorinated biphenyl in human blood.

Due to their physico-chemical characteristics, polychlorinated biphenyls (PCBs) are highly persistent in the environment and therefore easily measured in the biological matrices of more and more large groups of general population. For these reasons it would be useful to determine suitable Reference Values (RVs) for these xenobiotics. In this paper, a metanalysis to the published data on PCBs values in human blood is presented. This investigation was carried out in order to reach adequate information on their RVs and to focus some specific topics to be taken into account when producing directly RVs for PCBs. The PCBs RVs resulted between 1.2 e 8.28 microg/L for males and between 2.69 e 5.17 microg/L for females the general range varied from 0.9 to 56 microg/L. The main criticisms in the assessment of RVs for PCBs resulted: the number of examined subjects; the inclusion and stratification criteria; the analytical method adopted and their quality assurance; the type and number of congeners to be determined and their specific quantification; the calculation of blood PCBs concentration (weight/volume or weight/lipids); the statistical analysis and in particular the treatment of not detectable data.

Age Factors↗

PubMed1999

Peritoneal fluid urea nitrogen and creatinine reference values.

OBJECTIVE: To evaluate urea nitrogen and creatinine levels in peritoneal fluid. METHODS: We prospectively evaluated 20 consecutive women having radical hysterectomy with lymphadenectomy. On postoperative days 2 and 3, serum, urine, and peritoneal fluid samples were tested for urea nitrogen and creatinine. Using power analysis we calculated an adequate sample size to be 16 patients. RESULTS: The mean urea nitrogen was 11 mg/dL in serum, 11 mg/dL in peritoneal fluid, and 469 mg/dL in urine. The mean creatinine was .9 mg/dL in serum, 1.0 mg/dL in peritoneal fluid, and 141 mg/dL in urine. Urea nitrogen and creatinine values in peritoneal fluid and serum were essentially identical. Urine urea nitrogen and creatinine values were significantly greater than serum and peritoneal values (47 to 157 times greater) (P < .011). On postoperative days 2 and 3, serial levels of serum, peritoneal fluid, and urine urea nitrogen and creatinine in the same subject showed no significant variation (P ranging from .19 to .31). CONCLUSION: Normal reference values of urea nitrogen and creatinine in peritoneal fluid are equivalent to serum values and significantly less than urine levels.

Adult↗

PubMed2001

Interrupter resistance in preschool children: measurement characteristics and reference values.

There is a need for quick, reliable, and noninvasive lung function tests to assess airway obstruction in preschool children both for pediatric pulmonary care as well as for research purposes. We studied feasibility, reproducibility, and validity of measurements of the respiratory system using the interrupter technique (interrupter resistance [Rint]) and obtained reference values in children from a general population, 2 to 7 yr of age. Accuracy was studied by comparisons of Rint with plethysmographic airway resistance (Raw) in 20 patients (7 to 14 yr) with mild to severe chronic airways obstruction and was satisfactory in patients with FEV(1) > 60% predicted. The technique proved sensitive enough to detect changes in airway caliber within a small group of 12 children who developed mild respiratory tract infections. Among children from a general population, subgroups with mild respiratory symptoms or mild respiratory disease had higher mean Rint values. Airway obstruction was better detected using expiratory rather than inspiratory interruptions, both programmed at peak tidal ventilatory flow. Reproducibility within subjects was satisfactory (intraclass correlation 0.82 and 0.79). The same applied to interobserver agreement (intraclass correlation 0.98). The interrupter technique proves to be a reliable and practical test of airway function, suitable for clinical and epidemiologic studies in preschool children.

Age Factors↗

PubMed2003

Reference values for the geometric centre analysis of colonic transit measurements with 111indium-labelled diethylenetriamine penta-acetic acid.

The geometric centre analysis is often used for evaluating colonic transit data obtained by scintigraphy after oral intake of 111indium-labelled diethylenetriamine penta-acetic acid (111In-DTPA). The purpose of this study was to establish reference values for the geometric centre analysis in adult humans. Forty-eight healthy volunteers (24 women, 24 men) who were equally distributed among three age groups (young, middle-aged, elderly) were studied. In all subjects the geometric centre of radioactivity in the colon was calculated from abdominal gamma camera images acquired 24, 48, 72, and 96 h after oral administration of 111In-DTPA. Overall, the men had a higher geometric centre value than women after both 24 and 48 h indicating a faster progress of colonic contents in men at these time points. At each time point the geometric centre value was higher in both the young and middle-aged subjects than in the elderly subjects, whereas we did not find any difference between young and middle-aged subjects. Furthermore, the smokers had a higher geometric centre value than non-smokers at each time point. The geometric centre value was not influenced by body mass index at any time point.

Adult↗

PubMed1990

Determination of reference values for serotonin concentration in platelets of healthy newborns, children, adults, and elderly subjects by HPLC with electrochemical detection.

We adapted a high-performance liquid chromatographic method with electrochemical detection (Clin Chim Acta 1984;139:1-12) to the determination of platelet serotonin. We used this method to determine platelet serotonin reference values in a healthy population, measuring platelet serotonin concentration in the following subjects: 31 newborns (16 girls, 15 boys); 41 children (11 girls, 30 boys), ages 20 months to 15 years; 56 adults (26 women, 30 men), ages 20 to 58 years; and 20 elderly subjects (16 women, four men), ages 65 to 94 years. There was no significant difference in platelet serotonin concentration between sexes in each age group. However, significant changes (P less than 0.001) were observed between the newborns (mean +/- SD: 1.67 +/- 0.74 nmol/10(9) platelets) and the children (4.09 +/- 1.04) or the adults (3.81 +/- 0.87). Moreover, the platelet serotonin concentration in the elderly subjects (2.57 +/- 1.12) was significantly (P less than 0.001) lower than in the adults and children and significantly higher (P less than 0.01) than in the newborns. Such age-related differences must be taken into consideration when data from neurological or psychiatric patients and control subjects are compared.

Adolescent↗

PubMed1982

Calculation factors and reference values for quantitative lipoprotein electrophoresis in childhood.

Agarose gel electrophoresis of lipoproteins combined with quantitative densitometry (Lipidophor) and total cholesterol determination enables the calculation of alpha-, pre-beta-and beta cholesterol. This method is quick, precise and requires less than 100 microliters serum. The calculation factors originally derived from adults were re-evaluated and corrected for children. This was achieved by iterative calculation of the results obtained by quantitative densitometry and by enzymatic determination of the cholesterol contents in electrophoretically separated lipoprotein bands. Thus, calculation factors for children were obtained, which were used for the evaluation of reference values for alpha-, pre-beta- and beta-cholesterol and for the beta/alpha-lipoprotein ratio based on a reference group of 575 healthy children of 5-18 years of age.

Adolescent↗

PubMed2002

Bone mineral density reference values in the normal female and male population of Izmir, Turkey.

In this study we aimed to establish the dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) reference values of healthy Turkish women and men residing in Izmir, western Turkey. We examined 347 women and 119 men (age range 20-80 years) who did not have any known risk factor that might affect bone mass. The BMD measurements were performed by Hologic QDR 4500 W Elite DXA instrument from the lumbar spine (L1-L4) and non-dominant hip. In women the mean BMD (g/cm(2))+/-standard deviation (SD) of the normal reference group between 20 and 39 years of age was 0.963+/-0.121 g/cm(2) in the lumbar spine and 0.891+/-0.119 g/cm(2) in total femoral region. The percentages of annual and total BMD losses in women between 30 and 80 years of age were 0.74 and 29% at spinal level and 0.65 and 26% in femoral region, respectively. The average BMD of the normal men's group between 20 and 39 years of age was 0.996+/-0.111 g/cm(2) in the lumbar spine and 1.025+/-0.110 g/cm(2) in femoral region. The percentages of annual and total BMD losses were 0.33 and 13% at spinal level and 0.50 and 20% in femoral region, respectively. In conclusion, like the values reported from mid-Anatolian region of Turkey, the BMD values of Turkish women and men residing in Izmir, western Anatolia, are also lower than in most European countries with regard to US and preinstalled Hologic values.

Absorptiometry, Photon↗

PubMed1996

Gestational age-related reference values for amniotic fluid amino acids: a useful tool for prenatal diagnosis of aminoacidopathies.

In this study we have measured the concentration of 24 amino acids and total homocysteine in amniotic fluids obtained between the tenth and 32nd week of gestation from pregnancies not at risk for metabolic diseases. These results are used as reference values to which are compared values obtained from pregnancies at risk for citrullinaemia, argininosuccinic aciduria, HHH (hyperornithinaemia, hyperammonaemia and homocitrullinaemia) syndrome, cobalamin metabolism disorders (CblC or CblD), and sulphite oxidase deficiency. We discuss the helpfulness of amino acid analysis in amniotic fluid for prenatal diagnosis of aminoacidopathies.

Amino Acid Metabolism, Inborn Errors↗

PubMed2002

Reference values for lactic dehydrogenase activity and isoenzyme distribution in cerebrospinal fluid in neonates with fever but no evidence of cerebral disease.

Levels of lactic dehydrogenase (LDH) in the cerebrospinal fluid (CSF) have been used to evaluate a variety of neurologic disorders. However, few studies have been performed on neonates. CSF samples were collected from 39 neonates, 19 aged 1-4 weeks and 20 aged 5-8 weeks with neonatal fever. Findings were compared to those in 15 infants mean age 10 +/- 6.4 months with suspected nervous system disease and normal CSF findings. Mean total LDH activity in the CSF was significantly higher in the first month of life than in the second month of life and compared with the control group (p <0.001). The LDH isoenzyme pattern was also different, with lower values of LDH-1 than LDH-2 and -3 in the study groups. Differences were significant among all three groups for LDH-1 (p <0.001) and between the whole study group and the controls for LDH-2 and -3 (p <0.001). We propose reference values for total LDH activity and LDH isoenzyme distribution in the CSF of normal neonates.

Fever↗

PubMed1984

[Contribution to the definition of reference values of various enzymes in the cerebrospinal fluid].

The authors studied the behaviour of a few cerebrospinal fluid enzymes (GOT, GPT, LDH, ALP, CK, gamma-GT, PCHE) obtained from 26 patients without neurologic diseases. The stability of the enzymes has been verified in experimental various conditions, after store of the samples at different times and temperatures. This research has been carried in order to contribute to the determination of the reference values and to relieve their possible alterations.

Cerebrospinal Fluid↗

PubMed1992

Single fiber EMG reference values: a collaborative effort. Ad Hoc Committee of the AAEM Special Interest Group on Single Fiber EMG.

Single fiber electromyography (SFEMG) measurements of fiber density and jitter are used in the diagnosis of a variety of peripheral nervous system disorders. However, the normal values of these measurements for most muscles and age groups are not well documented in the literature. We present a retrospective and prospective multicenter collection of SFEMG jitter and fiber density data from control subjects obtained for the purpose of defining reference values for many muscles and different ages. The data and calculated upper limits for fiber density, individual pair jitter, and mean jitter are presented for each muscle in tabular and graphical format, for different age groups.

Action Potentials↗

PubMed1997

[Reference values for blood and serum selenium in the Dresden area].

BACKGROUND: To ensure a correct interpretation of patient's data the regional differences in the supply with selenium have to be taken into consideration. PATIENTS AND RESULTS: In 256 healthy women and men from the area of Dresden aged 20 to 62 years the selenium reference values were examined in blood serum by 1.09 +/- 0.17 (0.75 to 1.43) and in whole blood by 1.29 +/- 0.21 (0.87 to 1.71) mumol/l. There was no dependence upon age and sex and no influence of alcohol, tobacco and vegetarian diet was found. Consumption of beer yeast and frequent fish meals caused improvement of the selenium status. CONCLUSION: In area of Dresden, similar to the whole of Germany, a marginal selenium supply exists. Therefore it is of high importance to consider a balanced nutrition and to control the selenium status especially in serious acute diseases and in intensive care.

Adult↗