A new PCR MIMIC strategy to quantify low mdr1 mRNA levels in drug resistant cell lines and AML blast samples

Determination of the MDR-phenotype in patients suffering from AML is an important hallmark of treatment outcome but is often complicated by technical problems in P-gp assessment. A PCR-MIMIC strategy was employed to construct PCR-fragments for a competitive and quantitative mdr1 reverse transcription-PCR-assay. Using K562 cells, which had been selected for drug resistance to the epipodophyllotoxin VP16, a stepwise increase of mdr1 levels depending on the concentration of VP16 was shown with the MIMIC technique. Comparison of mdr1 levels in drug selected K562 cells with the corresponding levels for P-gp and functional data indicated a mRNA threshold that has to be exceeded for the full expression of the MDR-phenotype. Subsequently mdr1 levels of 34 samples of de novo acute myeloid leukemia were determined with the PCR-MIMIC strategy. Ten patient samples could be identified with elevated mdr1 levels which were substantially lower than the levels observed in the MDR-cell line K 562 0.7 microM VP16. Outcome analysis revealed that eight of the ten patients had an unfavourable prognosis and did not achieve CR after induction chemotherapy. Coexpression of mdr1 and CD 34 was not associated with CR in all examined cases. Moreover all these patients had unfavourable cytogenetic aberrations. These data indicate a sensitive technique with applicability in patient material.

Evaluation of procollagen-III peptide as a marker for veno-occlusive disease after bone marrow transplantation

Procollagen-III peptide (PIIIP) has been suggested as a marker for hepatic veno-occlusive disease (VOD) after bone marrow transplantation (BMT). Using the RIA-gnost PIIIP assay, we examined frozen plasma samples from three groups of patients. The groups included (A) four patients with clinically proven VOD, (B) nine patients with remarkably uneventful post-BMT courses, and (C) patients with either early complications other than VOD or pulmonary fibrosis in their later course. In group A, PIIIP levels increased parallel to the clinical course, with maximum values of 2.7-5.5 units/ml. In group B, values did not exceed 1.4 units/ml. In group C, higher values were occasionally observed. In one patient with early relapse of a lymphoma PIIIP peaks correlated with episodes of fever and graft versus host disease (GVHD). In another patient mild VOD seems possible retrospectively. The highest levels ( > 15 units/ml) occurred in one patient with ileus. Several patients with interstitial pneumonia (IP), adult respiratory distress syndrome (ARDS), or lung fibrosis showed increases in PIIIP levels corresponding to the clinical course; most of these events occurred later than day 30 after BMT. One patient with severe GVHD of the liver showed a maximum of only 1.4 units/ml. PIIIP elevation correlated with clinical VOD and may help to differentiate it from hepatic GVHD. In the presence of other complications (pulmonary, gastrointestinal), some caution in interpreting the results may be advisable.

Very fast ultracentrifugation of serum lipoproteins: influence on lipoprotein separation and composition

A very short run time and small sample volumes in the separation of lipoproteins by preparative ultracentrifugation are needed for several investigations. Recently, a very fast sequential separation method was described that needs only 100 min for one run in a centrifugal field of 625,000 x g. We studied the influence of centrifugal fields of this dimension on lipoprotein separation and lipoprotein particle integrity using a Beckman Optima TLX ultracentrifuge with a TLA-120.2 rotor. Rotor speed (120/90/60/30.10(3) rev./min) and run time (100 min/3 h/6.7 h/27 h) were selected in such a way that the product of centrifugal field and run time remained constant. The first conditions correspond to the very fast ultracentrifugation (VFU) procedure with a centrifugal field of 625,000 x g. Thirty different plasma samples covering a wide range of lipid and protein concentrations were separated in the course of two centrifugal runs at densities of 1.006 and 1.063 kg/l which yielded very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and the subnatant of low-density lipoproteins, including high-density lipoproteins (HDL) and concomitant sedimented plasma proteins. The major lipid components of the lipoproteins, triacylglycerols, free and esterified cholesterol, phospholipids and the apolipoproteins B and A-I, were estimated considering the masses of the tube contents after a slicing procedure. Measurements of lipids and proteins showed a very good recovery of better than 94% and 91%, respectively, and precision-within-series (coefficient of variation) of better than 4.2% and 6.5%, respectively. The effects of the rotor speed on the lipoprotein structure appeared to be weak. With increasing rotor speed, VLDL and LDL lipid constituents principally tended to decrease, whereas they increased in the subnatant of the LDL-run. The mean lipoprotein mass composition, considering the mass percentage of each measured particle constituent, did not show significant alterations. Total protein decreased in VLDL and in LDL and increased in the subnatant of the LDL-run. As checked by an enzyme-linked immunosorbent assay (ELISA) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), the protein effects were due to nearly complete disappearance of contaminating plasma proteins, especially albumin as the major contamination of VLDL and LDL. The apolipoproteins (apo) B-100, A-I, E and C-I to C-III remained nearly unaffected. The main advantages of VFU were the very short run time (cumulative flotation time is 3.4 h) and the elemination of albumin without repeated runs. The procedure was suitable for the assessment of lipid and protein constituents in lipoproteins from very small plasma samples (500 microliters).

Immunomodulating effect of ursodeoxycholic acid therapy in patients with primary biliary cirrhosis

Peripheral blood lymphocytes of 22 patients with primary biliary cirrhosis under ursodeoxycholic acid therapy were examined for selected lymphocyte activation markers. The percentage of dipeptidyl peptidase IV positive Peripheral blood lymphocytes of primary biliary cirrhosis patients by using immune- and enzyme-histochemical staining was found to be low (5-12%), with healthy controls exhibiting a normal range of 18-27%. After pokeweed mitogen stimulation in vitro the interleukin-2 production by peripheral blood lymphocytes in primary biliary cirrhosis patients was significantly decreased (3.135 pg/ml mean value), compared to healthy subjects (61.167 pg/ml mean value). After 4-20 weeks ursodeoxycholic acid treatment the dipeptidyl peptidase IV expression and IL-2 production were normalised. These results provide evidence for the immunomodulating effect of ursodeoxycholic acid.

[Dipeptidyl-peptidase IV of human lymphocytes in patients with primary biliary cirrhosis and UDCA therapy]

Investigations concerning changes of dipeptidyl-peptidase IV-positive (DP IV+) lymphocytes in the peripheral blood (PBL) were undertaken in 22 patients with primary biliary cirrhosis (PBC) under therapy with ursodeoxycholic acid (750 mg/day). We found that 4-8 weeks after therapy beginning the number of DP IV+ PBL was raised from a low initial suppressed level of 5-12% into a range of 18-33% corresponding to that of a healthy. Concurrently liver function parameters of the patients were improved significantly. The identity of DP IV+ and CDw26+ of peripheral T-cells could be shown by combination of the cytochemical DP IV-staining with the indirect immunofluorescence of the lymphocyte marker CDw26. These results show that the UDCA-therapy in patients with PBC has a direct effect on the immune system and a positive influence on the immuno-regulative capacity.

[Dipeptidyl peptidase IV of peripheral blood lymphocytes in patients with primary biliary cirrhosis]

Investigations concerning changes of dipeptidyl-peptidase IV-positive (DP IV+) lymphocytes in the peripheral blood (PBL) were undertaken in 22 patients with primary biliary cirrhosis (PBC) under therapy with ursodeoxycholic acid (750 mg/day). We found that after 4-8 weeks of therapy the number of DP IV+ PBL was raised from an initially low, suppressed level of 5-12% to 18-33% corresponding to the range observed in healthy subjects. Concurrently liver function parameters of the patients were significantly improved. The identity of DP IV+ CD 26+ peripheral T-cells could be shown by the combination of cytochemical DP IV-staining with the indirect immuno-fluorescence of the lymphocyte marker CD 26. These results show that the UDCA-therapy in patients with PBC has a direct effect on the immune system and a positive influence on the immuno-regulative capacity.