Mitochondrial genotype and risk for Alzheimer's disease: cross-sectional data from the Vienna-Transdanube-Aging "VITA" study.

The Vienna Transdanube Aging (VITA) study searches for early markers of Alzheimer's disease (AD) by examining the mental status in a community-based cohort of 606, 75-years old volunteers that are then related to various clinical and genetic analyses. To determine whether mutations in mtDNA are involved in expression of AD, the mtDNA of 79 "control" participants is screened for alterations by sequencing of "hot-spot-regions". This study on mtDNA mutations has eliminated the influence of aging on the occurrence of mtDNA alterations by sequencing samples from persons at the age of exactly 75 years. Thus, our cohort reveals a snap-shot of mitochondrial sequences of elderly persons. So far, a high percentage (56%) of persons with known or unknown mutations in the fragments analyzed were found. These data will be compared in due time to a cohort of participants with proven late-onset AD.

Quantitative FISH analysis and in vitro suspension cultures of erythroid cells from maternal peripheral blood for the isolation of fetal cells.

Several techniques for the enrichment of nucleated fetal red blood cells present in maternal blood have been reported. Here we describe the use of a quantitative fluorescence in situ hybridization (FISH) method and in vitro suspension cultures of erythroid cells from newborn cord blood and maternal peripheral blood. Together with a rapid high performance liquid chromatography (HPLC) method, that allows us to determine as few as 100 cells containing haemoglobin F (HbF), we have scrutinized the reported enrichment methods for fetal nucleated cells in peripheral maternal blood. One hundred FISH analyses on maternal peripheral blood were performed. The method comprises a cell lysis method for depletion of red cells with minimal losses of nucleated cells, uniform numbers of cells (750 000 cells each) on microscopic slides, and inclusion of internal controls to monitor the efficacy of hybridization. Twenty-six cultures of pure erythroid progenitor cells from maternal peripheral blood were analysed for the expansion of fetal cells. To generate these in vitro cultures, nucleated cells from 10-20 ml of peripheral blood from 26 pregnant women were grown in media containing growth factors and hormones to yield over 10(7) of immature erythroid cells within two weeks. Of those, 13 cultures were from pregnancies with confirmed male fetuses. A total of approximately 8x10(8) maternal cells were added into tissue culture medium for these 13 cultures, resulting in about 2x10(8) nearly pure erythroid cells after two weeks. Whereas fetal cells, alone or added into cultures of peripheral blood, grow rapidly and can be detected quantitatively, we could not find any fetal cells in cultures from maternal blood. Likewise, in 7.5x10(7) peripheral blood cells probed by FISH analysis (half of which were from pregnancies with male fetuses) no single Y chromosome was detected. In summary, suspension cultures of erythroid cells can be established routinely and easily. With the quantitative FISH technique used, 750 000 cells per slide can be screened reliably for cells with Y chromosomes. However, the stringent quality-criteria and most elaborate methods indicate that fetal cells in maternal peripheral blood can not be found using the current technology.

Diagnostic challenges of hepatitis C virus infections.

In less than 10 years, tremendous progress has been made in our understanding of the biology of hepatitis C virus. Since it was defined as the causal agent of most hepatitis non-A, non-B infections in 1989, clinical laboratories now have access to powerful new techniques for the diagnosis of infection and control of therapy. Identification of the specific virus strain in the patients as well as measurement of the individual viral load and the prediction of a possible therapeutic success have become routine procedures. This effort is warranted because the treatment options are still limited, with alpha-interferon being the only approved drug. No new treatment regimens have emerged yet from the wealth of data from subtyping and quantitating.

Development of a rapid means of estimating the haemoglobin F content of candidate fetal cells isolated from maternal blood using HPLC.

Prenatal diagnosis of genetic disorders in nucleated fetal red blood cells present in maternal blood requires methods to detect and enrich for such cells. Here we describe a rapid high performance liquid chromatography (HPLC) method that allows one to determine as few as 100 cells containing haemoglobin F (HbF) in the presence of a vast excess of haemoglobin A (HbA)-producing cells. The HPLC separations of haemoglobins were performed with a weak cation exchange column-silica gel-bound asparaginic acid-and ammonium phosphate buffer as the mobile phase. Separations were carried out in 7 min. When applied to estimation of the recovery of fetal cells from maternal blood, the HPLC method indicates in a timely manner whether or not to proceed with further techniques (i.e., FISH or PCR). Several current techniques such as Ficoll gradients and fluorescence (FACS) or magnetic (MACS) activated cell sorting were thus evaluated. Unexpectedly, our method indicates high cell losses with both single gradient and triple density Ficoll pre-enrichment methods. Less than 20 per cent of the nucleated red blood cells can be recovered in the most optimal setting. Lysis of erythrocytes may be an alternative technique that leaves nucleated red blood cells of all maturation stages intact. Thus, any further improvements in the technology for fetal cell recovery may be aided by monitoring the yield with HPLC.

[Immunophenotyping of leukemia: overview]. / Immunphänotypisierung von Leukämien: Ubersicht.

Leukaemias that cannot be classified properly by morphological/cytochemical parameters may be diagnosed clearly by immunophenotyping. In this way, the neoplastic cells can be designated to either the myeloid or the lymphatic line of blood cells. Furthermore, myeloid leukaemias can be subtyped immunophenotypically in cases of type M0, M6, and M7, leukaemias, as well as in cases of mixed lineage or undifferentiated leukaemias. In patients with non-Hodgkin-lymphomas the cells can be characterized as being of B- or T-cell origin, and their activational or proliferative state can be assessed. Notably with acute lymphatic leukaemias, the prodigious therapeutical progress over the past years must be attributed to the refined definition of subtypes by immunophenotyping.

Serum neuron-specific enolase is a useful tumor marker for small cell lung cancer.

Small cell lung cancer (SCLC) may be potentially curable. A correct diagnosis of cancer cell type is important and serum markers are of great value. Although several markers have been suggested, they have been of limited value because of insufficient specificity. To assess the value of serum neuron-specific enolase (S-NSE) as a possible marker of SCLC, the serum levels of 81 patients with SCLC (59 patients with extensive disease and 22 patients with limited disease) were compared with the serum levels of patients with non-small cell lung cancer (N-SCLC) and 93 patients with nonmalignant lung diseases. The S-NSE level also was measured in 104 patients with extensive disease of various other malignancies, including 71 solid tumors and 33 malignant hematologic disorders. From 105 healthy control subjects, the upper limit of the normal range (x + 2 standard deviations [SD]) was determined as 12.3 ng/ml. The S-NSE level was elevated in 78% of patients with SCLC, including 11 of 22 (50%) with limited disease and 52 of 59 (88%) with extensive disease. In contrast, the S-NSE level was raised only in 18% of patients with advanced N-SCLC (nine of 50) and 6% of patients with nonmalignant lung diseases (six of 93). Twelve patients (17%) with other solid malignant tumors and two patients (6%) with malignant hematologic disorders had raised S-NSE levels. Serial N-NSE levels were obtained in 13 patients with SCLC. S-NSE levels fell in all patients responding to chemotherapy and increased again with progression of disease. Our results indicate that S-NSE seems to be specific for SCLC (85%), whereas sensitivity seems to be dependent on the stage of disease. Further, S-NSE may be a useful marker for monitoring treatment and predicting relapse in patients with SCLC.