Biomedical subjects

A Bierlich

Publications and source records attributed to A Bierlich.

3 recordsLinked to original sources

PubMed2001

The white blood cell differential: three methods compared.

The analysis of the automated blood cell count is an essential tool in haematological diagnostics. However, in the case of the white blood cell differential the microscopy method, although tedious, often serves as reference. We evaluated the ABX Pentra 120 Retic haematology analyser in comparison to the Coulter STKS haematology system and the microscopy method with respect to accuracy, precision and reliability. We compared 308 samples (239 samples from adults and 69 from children) including patients with oncological diseases. The comparison of the white blood cell differential revealed strong correlations between the results obtained with the ABX Pentra 120 Retic and the microscopy method, the Coulter STKS and the microscopy method and both automated methods (values of paediatric samples in parentheses; neutrophils: rs > or = 0.933 (rs > or = 0.951), lymphocytes: rs > or = 0.907 (rs > or = 0.945), monocytes: rs > or = 0.584 (rs > or = 0.459) and eosinophils: rs > or = 0.963 (rs > or = 0.966)). The analytical performance of automatic analysers for the detection of the morphological "left shift" was determined for all samples in comparison to the microscopical white blood cell differential. The sensitivity, specificity and efficiency depended strongly on the chosen threshold levels and were different for both analysers. The sensitivity for flagging a left shift increased with an increasing proportion of neutrophil bands, metamyelocytes, myelocytes and promyelocytes. Our study suggests that the ABX Pentra 120 Retic haematology analyser, as well as the Coulter STKS haematology system are useful tools for routine analysis in haematology.

Adult↗

PubMed2000

Determination of reticulocytes: three methods compared.

Determination of reticulocytes in peripheral blood is a valuable tool for getting information about erythropoiesis of an individual. For many years, reticulocyte numbers were quantified manually by means of a microscope after staining with supravital dyes. However, this method is tedious and shows low reproducibility. Therefore, several methods for the automated determination of reticulocytes have been established in laboratory routine within the last years. The aim of this study was to compare three of these automated methods for reticulocyte analysis. Reticulocytes were determined in 130 subsequent routine samples by means of an ABX Pentra 120 Retic haematological analyser, a Coulter EPICS XL MCL flow cytometer and a Coulter STKS haematology system, using the fluorescent dye thiazole orange or the supravital dye new methylene blue for reticulocyte staining, respectively. The reticulocyte concentrations were slightly lower for the Coulter STKS haematology system (mean +/- SD 1.89+/-1.32%) when compared with the Coulter EPICS XL MCL flow cytometer or the ABX Pentra 120 Retic haematological analyser (2.11+/-1.25% and 2.12+/-1.15%, respectively). The correlations between all methods were significant (r(s) > or = 0.843, p < 0.001). Small intercepts were, however, observed in the correlation plots between the values obtained by means of the Coulter STKS haematology system and those obtained by the other two methods. Within-batch coefficients of variation were 6.0%, 6.9% and 7.8% for the ABX Pentra 120 Retic haematological analyser, the Coulter STKS haematology system and the Coulter EPICS XL MCL flow cytometer, respectively. The corresponding between-batch coefficient of variation values were 6.8%, 4.9% and 5.3% as well as 14.1%, 7.6% and 6.1% for the low, medium and high control levels determined by means of the ABX Pentra 120 Retic haematological analyser and the Coulter STKS haematology system, respectively. These data suggest that all three methods allow the efficient and reliable determination of reticulocyte counts under clinical routine conditions. However, although the obtained data are very similar, differences exist which should be taken into account for the normal values of the different methods.

Automation↗

PubMed1999

[Prenatal diagnosis of heart defects and associated chromosomal aberrations].

AIM: According to epidemiological studies on newborns, the association of congenital heart defects with chromosomal anomalies varies between 4 and 12%. Prenatally this rate is probably higher, due to antenatal death occurring in fetuses with chromosomal aberrations. The aim of the study was therefore to determine the rate and the distribution of chromosomal aberrations in prenatally detected heart defects. PATIENTS AND METHOD: Within a period of 7 years fetal echocardiography was performed on 2716 fetuses at high risk for CHD. The analysis of the fetal heart was achieved by the visualization of different planes. Once a heart defect was detected, karyotyping was performed after amniocentesis, cordocentesis or chorion villous sampling, or in a few cases postnatally from cord blood. Prenatal ultrasound findings were confirmed postnatally by ultrasound examination or, in case of abortion, stillbirth or neonatal death, by autopsy. RESULTS: A total of 203 fetal heart malformations were detected and 46 of them (22%) had associated chromosomal anomalies. 60% of all cases and 80% of the study group had extracardiac anomalies. Only eight out of the 46 pregnant women (17.5%) were older than 35 years. Eight out of the 15 fetuses with trisomy 18 had a ventricular septal defect, 9/13 fetuses with trisomy 21 had an atrioventricular septal defect and all 5 fetuses with monosomy X had a left heart outflow obstruction. No typical cardiac defects were found in the remaining 13 fetuses (5 trisomy 13, 2 triploidies, 6 miscellaneous). Of the 13 live births (23 terminations of pregnancy and 10 intrauterine deaths) 6 children survived (46% and overall survival rate 13%). The following rates of associations with aneuploidies were found: atrioventricular septal defect 55%, ventricular septal defect and aortic coaction both 43%, tetralogy of Fallot and double outlet right ventricle both 36%. In comparison, fetuses with isomerism, transposition of the great arteries and pulmonary atresia or stenosis had normal chromosomes. CONCLUSION: We conclude that the rate of association of heart defects and chromosomal abnormalities is higher prenatally than in the neonatal period and is approximately 22%. After detecting a fetal cardiac malformation, karyotyping is mandatory for the further management of pregnancy. The likelihood of detection of an aneuploidy increases when some typical heart defects are detected or when an association with extracardiac anomalies is found.

Amniocentesis↗