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PubMed2002

Longitudinal motion of the atrioventricular annuli in children: reference values, growth related changes, and effects of right ventricular volume and pressure overload.

The goals of this study were to characterize normal patterns of longitudinal motion of atrioventricular annuli in the young, establish reference values and assess growth-related changes (n = 40). Sensitivity to changes in right ventricular volume and pressure load was assessed in patients with atrial septal defect (ASD) (n = 25) and with primary pulmonary hypertension (PPH) (n = 20). M-mode of the annuli were obtained from apical views. In healthy subjects, longitudinal %displacement decreased with growth, lateral tricuspid annulus had highest %displacement, velocity of annular descent did not change with growth, tricuspid lateral annulus had the highest velocity of descent, only ascent velocity of the lateral tricuspid annulus decreased with growth, velocities of ascent for the lateral annuli were similar and higher than the septum, and heart rate had no effect on parameters tested. In patients with ASD, the findings were an exaggerated normal pattern. In patients with PPH, %displacement and ascent velocities were blunted. Our results demonstrate the utility of this technique to assess annular dynamics in pediatric patients.

Adolescent↗
PubMedDate not supplied

Spirometric reference values from a Mediterranean population.

Maximal expiratory flow-volume (MEFV) curves were measured in 1044 healthy nonsmoking volunteers living in the Barcelona area, as part of a larger interhospital project to obtain reference values of pulmonary function tests. Forced vital capacity (FVC), one-second forced expiratory volume (FEV1), FEV1/FVC, %, forced maximal mid-expiratory flow (FEF25-75%), peak expiratory flow rate (PEF) and maximal expiratory flow at 50 and 75% of FVC (MEF50% and MEF25% respectively) were obtained and expressed at BTPS conditions. Techniques and equipments followed both the recommendations of the American Thoracic Society (ATS) and of the European Community for Coal and Steel (ECCS). Prediction equations for age 20 through 70 were calculated for both sexes from a final sample composed of 870 adult subjects, 443 males and 427 females. Simple linear equations using height, age and body weight predicted all spirometric variables as well as more complex equations except MEF25%. Logarithmic equations were proposed for MEF25% to correct for the heteroscedasticity shown in a simple linear model. To our knowledge, this study provides reliable spirometric equations from a large urban Mediterranean sample which were lacking so far in the literature.

Adolescent↗
PubMed2000

[Functional MRI of the pelvic floor. The methods and reference values].

PURPOSE: Functional cine MRI of the pelvic floor is a yet another modality in addition to various radiological fluoroscopic techniques. This article describes our own method in view of the recent literature and provides morphometric reference values. MATERIAL AND METHOD: We examined 20 nulliparous women (range of age: 25-51 years) with normal findings in the gynecological and urodynamic examination. Functional cine MRI was performed on a 1.5 Tesla equipment after opacification of the vagina and rectum. We used a T2-weighted gradient-echo sequence (Ture-FISP) to determine the position of the reference organs at rest and during straining/defecation. Two different reference lines were used. In addition 29 morphometric and functional parameters were measured, all of them being observer independent. RESULTS: Functional cine MRI was able to show the extent and interaction of the pelvic floor organs in all cases with the reference organs always remaining above the pubococcygeal reference line. The depth of the rectocele was 2 cm. With the exception of the diameter of urogenital hiatus the different parts of the levator ani muscle could not be determined. DISCUSSION: Functional cine MRI using an appropriate organ opacification and slice positioning is an objective, unifying diagnostic approach of the pelvic floor. The reference data given can be of help to distinguish normal from abnormal findings.

Adult↗
PubMed1991

A new device for measuring oral mucosal surface friction--reference values.

Sialometry and dryness measurements performed with a sliding friction instrument were carried out in healthy subjects and patients with oral dryness due to salivary gland diseases. The salivary flow rates were within normal reference values. The mean friction value in the healthy population was 1.73 +/- 0.37 in the lip mucosa and 1.25 +/- 0.31 in the buccal mucosa and did not show any age or sex differences. In the group of patients with salivary gland diseases, none produced measurable amounts of resting saliva but a few of them did produce small amounts of paraffin wax chewing-stimulated saliva. The friction instrument proved to register lubrication produced even by these very small amounts of saliva.

Adult↗
PubMed2004

Reference values for valve circumferences and ventricular wall thicknesses of fetal and neonatal hearts.

To evaluate valvular stenosis, cardiac dilation, and/or cardiac hypertrophy, measurements of valve circumference and ventricular wall thickness are of importance. To establish reference values in fetuses and neonates, we reviewed pathology reports at Women and Infants Hospital from 1978 through 2002 and found measurements in 776 cases that were suitable for analysis. Gestational ages (GA) ranged from 15 to 42 wk. The tabulated data include the mean, standard deviation, and 10th and 90th percentile values for foot length, body weight, body length, heart weight, valve measurements, and ventricular wall thicknesses for each week of GA. In cases in which clinical dating is not reliable, we estimated the GA by the mean value nearest that of the observed foot length. All linear measurements increased in a linear fashion throughout the second and third trimesters of development. The circumferences of cardiac valves at all ages, in descending order of magnitude, are: tricuspid, mitral, pulmonary, and aortic. Mean left ventricular (LV) wall thickness is greater than mean right ventricular (RV) wall thickness throughout gestation. The tables offer a means of determining valvular stenosis, or cardiac dilation and/or hypertrophy, based on various gestational ages.

Fetal Heart↗
PubMed2005

Semen analysis in fertile patients undergoing vasectomy: reference values and variations according to age, length of sexual abstinence, seasonality, smoking habits and caffeine intake.

CONTEXT AND OBJECTIVE: Recent studies have shown regional and population differences in semen characteristics. The objective was to establish reference values for semen analysis and to verify the effect that age, length of sexual abstinence, seasonality, smoking habits and coffee consumption have on fertile individuals' semen characteristics. DESIGN AND SETTING: Prospective study in the Urology Division, Hospital das Clínicas, Universidade de São Paulo. METHODS: Between September 1999 and August 2002, 500 fertile men requesting a vasectomy for sterilization purposes were asked to provide a semen sample before the vasectomy. We evaluated the effects of age, sexual abstinence, seasonality, smoking and coffee consumption on semen characteristics. RESULTS: Compared with World Health Organization values, 87.2% of the patients presented sperm morphology below the normal level. A significant decline in semen volume, sperm motility and sperm morphology in patients over 45 years of age was observed. In patients with 5 days or more of abstinence, there was reduced sperm motility. The lowest values for sperm concentration, motility and morphology were observed in summer and the highest in winter. No differences in semen parameters relating to smoking were detected. Patients who drank six or more cups of coffee per day presented higher sperm motility. CONCLUSIONS: Our sample had a very low percentage of normal sperm morphology. Only sperm morphology showed a high abnormality rate. Differences in semen parameters with regard to age, length of sexual abstinence, seasonality and coffee consumption were identified. No differences relating to smoking were detected.

Adult↗
PubMed1994

Reference values and hematologic changes from birth to 5 years in patients with sickle cell disease. Cooperative Study of Sickle Cell Disease.

OBJECTIVE: To examine hematologic changes from birth to 5 years of age and establish hematologic reference values for infants and children with sickle cell disease. RESEARCH DESIGN: Prospective natural history study. SETTING: Nineteen pediatric sickle cell centers across the United States. PATIENTS: Six hundred ninety-four infants with sickle cell disease (sickle cell anemia, sickle cell-hemoglobin C disease, and sickle-beta-thalassemia) who were enrolled in the Cooperative Study of Sickle Cell Disease at younger than 6 months of age. Median follow-up time through 5 years of age was 4.1 years. MEASUREMENTS AND RESULTS: We present longitudinal analyses of total hemoglobin concentration, percent fetal hemoglobin values, mean corpuscular volumes, total bilirubin concentration, and red blood cell (RBC), "pocked" RBC, white blood cell, platelet, and reticulocyte counts. Anemia was apparent by 10 weeks of life in infants with sickle cell anemia (SS infants). This anemia was associated with a rising reticulocyte count consistent with a hemolytic process. The reticulocyte count of SS infants increased steadily, exceeding 12% at 5 years of age. The fetal hemoglobin concentration of SS infants declined more slowly than that of infants with sickle cell hemoglobin C disease (SC infants). Pocked RBC counts rose sharply after 6 months of age, and by 1 year, 28% of SS infants had abnormal counts, above 3.5%, indicating poor splenic function. At 3 years of age, 78% of SS patients and 32% of SC patients had abnormal pocked RBC counts. The SS patients with concurrent alpha-thalassemia had, after 6 months of age and throughout early childhood, a slightly higher mean total hemoglobin concentration and lower mean pocked RBC and reticulocyte counts than SS patients without alpha-thalassemia. The hematologic profile of SC infants more closely resembled that of normal black infants, but there was mild anemia (10.5 g/dL) and slightly elevated mean values for reticulocytes (3%) and fetal hemoglobin (3%) during early childhood.

Age Factors↗
PubMed1999

Arterial blood gas reference values for sea level and an altitude of 1,400 meters.

Blood gas measurements were collected on healthy lifetime nonsmokers at sea level (n = 96) and at an altitude of 1,400 meters (n = 243) to establish reference equations. At each study site, arterial blood samples were analyzed in duplicate on two separate blood gas analyzers and CO-oximeters. Arterial blood gas variables included Pa(O(2)), Pa(CO(2)), pH, and calculated alveolar-arterial PO(2) difference (AaPO(2)). CO-oximeter variables were Hb, COHb, MetHb, and Sa(O(2)). Subjects were 18 to 81 yr of age with 166 male and 173 female. Outlier data were excluded from multiple regression analysis, and reference equations were fitted to the data in two ways: (1) best fit using linear, squared, and cross-product terms; (2) simple equations, including only the variables that explained at least 3% of the variance. Two sets of equations were created: (1) using only the sea level data and (2) using the combined data with barometric pressure as an independent variable. Comparisons with earlier studies revealed small but significant differences; the decline in Pa(O(2)) with age at each altitude was consistent with most previous studies. At sea level, the equation that included barometric pressure predicted Pa(O(2)) slightly better than the sea level specific equation. The inclusion of barometric pressure in the equations allows better prediction of blood gas reference values at sea level and at altitudes as high as 1,400 meters.

Adolescent↗
PubMed1983

Reference values for the oral glucose tolerance test at each trimester of pregnancy.

A 100-gram oral glucose tolerance test (OGTT) was performed on a selected group of normal women at each trimester of pregnancy to establish reference values for hyperglycemia and hypoglycemia. Ninety three OGTT were performed in the first trimester, 121 in the second trimester, and 98 in the last trimester. The fasting serum glucose did not differ significantly between the trimesters. The values at 60 and 120 minutes were significantly different for the fifth, fiftieth, and ninety-fifth percentiles between each trimester of pregnancy. For the 180-minute readings, the fifth and fiftieth percentiles were not significantly different between the first and second trimester of pregnancy, but the results of the third trimester were significantly higher than those of the other trimesters. The mean fasting insulinemia remained relatively constant during pregnancy. Insulin response to OGTT increased during the progression of the pregnancy. The interpretation of the glucose tolerance tests during pregnancy, either to detect gestational diabetes or hypoglycemia, should take these physiologic changes into account.

Blood Glucose↗
PubMed1991

Hand-held myometry: reference values.

In thirteen major muscle groups of 50 healthy females and 50 males, aged 20-60 years, maximum voluntary contraction was measured with a hand-held dynamometer. The intrasession variation, the left-right variation, and the fifth and fiftieth centile values were calculated. The ratio of two observations within one session ranged from 0.85 to 1.18 and the ratio of left to right ranged from 0.82 to 1.22 (95% reference limits). In 20 volunteers the repeatability was tested after one week. The ratio of averages of three measurements in two successive weeks ranged from 0.82 to 1.23 (95% reference limits). There were only small differences between muscle groups concerning these ratios. A significant relation with age and weight/Quetelet Index could be demonstrated in some muscle groups. The mean strength of females is approximately two thirds of the strength of males. The data may be useful as reference values in the application of hand-held myometry.

Adult↗
PubMed1988

Reference values for 75 g oral glucose tolerance test in pregnancy.

A 75 g oral glucose tolerance test was performed in 212 pregnant women with no predisposing factors suggesting glucose intolerance to establish the normal pattern of glucose metabolism in pregnancy. Reference values for the test were established for the middle of pregnancy (14-20 weeks, n = 43) and late pregnancy (28-37 weeks, n = 168). One woman was excluded because she had diabetes that required treatment with insulin. There were statistically significant differences between the two groups for samples taken both one and two hours after the glucose load. Reference ranges for the interpretation of the glucose tolerance test in pregnancy should therefore take account of the period of gestation. Arbitrary upper limits of normal (represented by the 97.5 centile) two hours after a 75 g oral glucose load are proposed at 7.5 and 9.6 mmol/l for the second and third trimesters, respectively.

Blood Glucose↗
PubMed2001

Reference values of fetal peak systolic blood flow velocity in the middle cerebral artery at 19-40 weeks of gestation.

OBJECTIVES: The objectives of this prospective study were (i) to establish new reference values of peak systolic blood flow velocity measurement in the fetal middle cerebral artery (MCA-PSV) following validated methodological guidelines and (ii) to develop a method to calculate Z-scores of MCA-PSV. PATIENTS AND METHODS: Cross-sectional data were obtained from 331 pregnant women between 19 and 40 weeks' gestation. Reference ranges for MCA-PSV were constructed and for each measurement linear regression models were fitted separately to the mean and standard deviations (SD) as a function of gestational age. An application to calculate Z-scores was developed. A comparison was made between the reference ranges produced in our study and those of a previous one. RESULTS: A new chart, table of centiles and regression equations of MCA-PSV are presented. Comparison of our reference ranges with ones produced in a previous study showed similar 5th centile values. However, the values for the 50th and 95th centiles between 19 and 28 gestational weeks were lower in our study. CONCLUSIONS: We have constructed reference ranges for MCA-PSV which, because they are derived from a larger number of examinations in the 15-20-week period and because the methodological flaws of the previously published study have been eliminated, we consider to be more accurate and therefore more useful for clinical practice.

Blood Flow Velocity↗
PubMed1982

A pilot study of the reference values for the commoner haematological and biochemical parameters in Saudi nationals.

A study of 16 haematological and 24 biochemical parameters in healthy, adult, male, volunteer Saudi blood donors was made, and enabled a preliminary determination of the reference values for these parameters to be made for Saudi Arabia. Statistically significant low means were observed for all the haematological parameters except the mean corpuscular haemoglobin concentration which was raised above Western levels and the mean corpuscular haemoglobin which was normal. A low total leucocyte count was seen to be due largely to a low neutrophil count, but accompanied by a raised lymphocyte count. The main biochemical differences were raised concentrations of serum albumin, alkaline phosphatase, conjugated bilirubin, aspartate aminotransferase, "liver" lactate dehydrogenase and alanine aminotransferase. Decreased concentrations of serum globulin, unconjugated bilirubin and calcium were also found. These changes are discussed in relation to putative endemic disease, ethnic origins and environmental factors.

Adult↗
PubMed1979

Immunochemical determination of serum transferrin. Reference values, correlation with serum total iron-binding capacity and value in the diagnosis of iron deficiency anaemia and anaemia of chronic disorders.

Immunologically determined reference values of serum transferrin are presented for adults and children. A good correlation between serum transferrin and total iron-binding capacity values was found. In 2 groups of anaemic patients - 51 patients with iron deficiency anaemia and 45 patients with anaemia of chronic disorders - serum transferrin determination distinguishes the two groups of anaemic patients from normals somewhat better than TIBC determination.

Adolescent↗
PubMed2006

Genotype-corrected reference values for serum angiotensin-converting enzyme.

The deletion (D)/insertion (I) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene has the greatest impact on serum ACE level in Caucasians of any factor yet discovered. The aim of the present study was to establish new ACE genotype-corrected normal ranges for serum ACE level in a population of central European origin. After a medical examination, 159 healthy Caucasians volunteered to donate blood for the study. ACE genotypes were assessed by PCR and serum ACE levels were determined using two different kinetic tests. The distribution of the D/I polymorphism of the ACE gene was in accordance with the Hardy-Weinberg equilibrium. Serum ACE levels and ACE genotypes correlated significantly, with the highest serum ACE levels in subjects with ACE genotype D/D, and the lowest serum ACE levels in subjects with genotype I/I (mean+/-sd, assay 1: D/D 59.3+/-15.1 U x L(-1), D/I 45.5+/-15.2 U x L(-1), I/I 34.8+/-13.7 U x L(-1); assay 2: D/D 43.7+/-14.1 U x L(-1), D/I 33.7+/-12.1 U x L(-1), I/I 25.4+/-9.5 U x L(-1)). Although they gave different absolute values of serum ACE levels, the results of the two test kits correlated significantly. In conclusion, the present authors recommend the use of new, genotype-specific reference values for serum angiotensin-converting enzyme levels, especially to improve the sensitivity and specificity of tests for angiotensin-converting enzyme in the follow-up of sarcoidosis.

Adolescent↗
PubMed1996

[Comparison of different types of peak flow meter and reference values for peak expiratory flow (PEF) for healthy Japanese subjects].

Any observed value of PEF in a given subject must be assessed by comparing it with that achieved by a normal healthy individual of the same race, sex, age, and, height. I introduce reference values for PEF for healthy Japanese subjects (established in 1995) for this purpose. During our survey, however, we observed considerable differences in references obtained by four different types of PEF meter (mini-Wright, Assess, Personal Best, and Vitalograph). This is an important observation that warrants our further investigation.

Adolescent↗
PubMed1986

Reference values of regional ventilation, lung volumes and perfusion assessed by using an automated multidetector 133-Xe radiospirometer.

The distributions of ventilation, lung volumes and perfusion were studied in 56 healthy non-smoking Finnish adults to get reference values for a computerized 133-Xe radiospirometer with 16 detectors and moveable designed collimators (Valmet BI 1200). The age of the subjects ranged from 20 to 60 (mean 36.5, SD 9.1) years. Thirty-one of them were men. In addition, the reproducibility of the method was tested in 13 patients with pulmonary diseases. The measurements were made with the subjects in supine position. The studied variables showed no correlation with sex or age. The interpulmonary and intrapulmonary percentage distributions between 16 pulmonary subareas were calculated for the following variables: ventilation (V) (assessed from wash-in curves), functional residual capacity (FRC), vital capacity (VC), total lung capacity (TLC), wash-out time during tidal breathing (T1/2 V), perfusion (Q) (at TLC level), wash-out time after breath-holding during the perfusion study (T1/2 Q), specific ventilation (V/FRC), specific perfusion (Q/TLC), and V/Q ratio. The percentage proportion (mean and SD) in the right lung of V was 50.5 (2.6), of FRC 51.7 (2.1), of VC 51.0 (1.8), of TLC 51.1 (1.7), and of Q 50.8 (3.0). Apical parts of the lungs showed smaller functional proportions than the other parts. There was a significant tendency to increasing basal and decreasing apical proportions of V, VC, TLC and FRC with increasing height and weight. Coefficients of variation (CoV) of the distribution indices for the whole lung varied between 1.9 and 5.0%. We suggest that the distribution data obtained here are helpful in clinical work when evaluating the distributions in patients studied with the Valmet BI 1200 radiospirometer.

Adult↗