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Age estimation in small children: reference values based on counts of deciduous teeth in Finns.

The eruption of teeth in the mouth is suitable for age estimations during the period when teeth are actively emerging, in the deciduous dentition phase approximately from the age of 6 months to 2.5 years. Estimations of age can be performed simply by counting the number of teeth in the mouth. Reliability of the estimates depends on the reference data available and each population group should preferably have its own standards. In the present study timing of eruption of successive deciduous teeth was studied longitudinally in 129 Finns. The dates of clinical eruption of deciduous teeth were recorded by mothers and checked by dentists. In 40 of the 129 children emergence ages of at the most the four last teeth were based only on semiannual registrations performed by dentists. The main purpose was to provide normal timetables of tooth eruption in small children in forms that are practical in estimations of dental age. No sexual dimorphism existed in the timing of clinical eruption of successive deciduous teeth. The mean age corresponding to the presence of one tooth in the mouth was 7.1 months (S.D.=1.78) and that corresponding to tooth count 19 was 27.8 months (S.D.=3.99). If the chronological age is known, the presented distributions and means with variations make it possible to estimate the degree of advancement or delay in a child's dental development. If the age of the child is not known, the mean and median ages can be used for estimations of chronological age. However, estimations of age should not be based only on tooth counts because of marked variation also within this homogeneous group.

Adult↗

Reference values for lung function tests. III. Carbon monoxide diffusing capacity (transfer factor).

Carbon monoxide diffusing capacity (DLCO) or transfer factor (TLCO) is a particularly useful test of the appropriateness of gas exchange across the lung alveolocapillary membrane. With the purpose of establishing predictive equations for DLCO using a non-smoking sample of the adult Brazilian population, we prospectively evaluated 100 subjects (50 males and 50 females aged 20 to 80 years), randomly selected from more than 8,000 individuals. Gender-specific linear prediction equations were developed by multiple regression analysis with single breath (SB) absolute and volume-corrected (VA) DLCO values as dependent variables. In the prediction equations, age (years) and height (cm) had opposite effects on DLCOSB (ml min-1 mmHg-1), independent of gender (-0.13 (age) + 0.32 (height) - 13.07 in males and -0.075 (age) + 0.18 (height) + 0.20 in females). On the other hand, height had a positive effect on DLCOSB but a negative one on DLCOSB/ VA (P < 0.01). We found that the predictive values from the most cited studies using predominantly Caucasian samples were significantly different from the actually measured values (P < 0.05). Furthermore, oxygen uptake at maximal exercise (VO2max) correlated highly to DLCOSB (R = 0.71, P < 0.001); this variable, however, did not maintain an independent role to explain the VO2max variability in the multiple regression analysis (P > 0.05). Our results therefore provide an original frame of reference for either DLCOSB or DLCOSB/VA in Brazilian males and females aged 20 to 80 years, obtained from the standardized single-breath technique.

Adult↗

Diffusing capacity for nitric oxide: reference values and dependence on alveolar volume.

Nitric oxide (NO) has a much stronger affinity for hemoglobin than carbon monoxide (CO); therefore, the DL(NO) (diffusing capacity for NO) is less influenced by changes in capillary blood volume than the DL(CO) (diffusing capacity for CO), and represents the true membrane diffusing capacity. We measured the combined single breath DL(NO)/DL(CO) in 124 healthy subjects, and generated reference equations for the DL(NO) and K(NO). In a subset of 21 subjects the measurements were performed on different inspiratory levels. The reference equation for DL(NO) in females is 53.47*H(height)0.077*A(age)-48.28(RSD5.22) and for males 59.84*H-0.25*A-44.20(RSD6.39). Reference equations for K(NO) in females is -2.03*H-0.025*A+11.52(RSD0.48) and for males -0.15*H-0.045*A+9.47(RSD0.65). The K(CO) (DL(CO)/V(A)) increases when V(A) (alveolar volume) decreases, probably due to an increase of blood volume per unit lung volume. The DL(NO) was much stronger related to the V(A), the K(NO) was almost independent of V(A). Because of the relative independence of the K(NO) on V(A), the K(NO) appears to be a much better index for the diffusion capacity per unit lung volume (transfer coefficient) than the K(CO).

Adult↗

Haematological reference values for adult pumas, lions, tigers, leopards, jaguars and cheetahs.

Normal haematological values and fibrinogen levels were obtained from a number of healthy adult Felidae in the collection of the Zoological Society of London. The group comprised 29 pumas (Felis concolor), 32 lions (Panthera leo), 27 tigers (P tigris), 19 leopards (P pardus), 18 jaguars (P onca) and 22 cheetahs (Acinonyx jubatus). The values provided a basis for identifying abnormalities in the blood of sick individuals of these species and for undertaking interspecies comparisons.

Acinonyx↗

Reticulocyte maturity pattern analysis as a predictive marker of erythropoiesis in paediatrics. Part I: Evaluation of age-dependent reference values.

Reticulocyte quantification in peripheral blood samples is a commonly used diagnostic indicator of erythropoietic activity. A methodology based on flow cytometry additionally separates reticulocytes into three groups by fluorescence staining of the residual RNA. This identifies cells as high (HFR), medium (MFR) and low (LFR) fluorescence intensity reticulocytes. In the present study an automated counter was evaluated and tested for its clinical applicability in paediatrics. In part I, reference intervals for different periods of childhood were determined. Except for the neonatal period there was no age-dependence so that children aged one week to 16 years have been summarized in one group. The wide variations we found in preterm children can be explained by different erythropoietic stimuli as the result of anaemia in infants with very low birthweight. No significant differences could be found between the sexes, not even at the onset of puberty. When using the reticulocyte maturity pattern analysis in clinical practice, the data give a helpful indication of the efficiency of the erythropoietic system.

Adolescent↗