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Biomedical subjects

C Haanen

Publications and source records attributed to C Haanen.

At least 181 records · Page 10Linked to original sources
PubMed1982

Adolescent and adult acute lymphoblastic leukemia: prognostic features and outcome of therapy. A study of 293 patients.

The case histories of 293 adolescent and adult patients with acute lymphoblastic leukemia (ALL) first seen and treated between 1969 and 1979 are reviewed. A complete remission (CR) was achieved in 79% of cases. Male sex, advanced age (greater than or equal to 30 yr old), and early CNS involvement were the major determinants of remission failure. Median duration of first CR was 16 mo, with 23 patients (actuarial proportion 25%) alive and relapse-free at 5 yr. The major determinant of first CR length was white blood cell (WBC) count (best cut-off value at 35 X 10(9)/liter). First CR length was also negatively affected by early CNS involvement, morphological FAB L3 subtype, and B-cell (Smlg+) leukemia, but these features were significantly associated with a high WBC count. First CR length in patients 11-15 yr old did not differ significantly from that of patients 16-59 yr old. The negative prognostic value of T-cell (E+) leukemia was not confirmed in this adult series. CNS prophylaxis provided an effective protection against CNS relapse. Maintenance chemotherapy was apparently more effective when 4 or more than 4 drugs were employed. "Low risk" patients (WBC count less than 35 X 10(9)/liter still relapsed rather frequently (32% at 1 yr, 49% at 2 yr), with 33% of them alive and relapse-free at 5 yr. "High risk" patients (WBC count greater than or equal to 35 X 10(9)/liter +/- early CNS involvement +/- morphological L3 subtype +/- B-cell leukemia) relapsed very quickly (50% at 6 mo. 70% at 1 yr), with only 6% of them relapse-free at 5 yr.

Actuarial Analysis↗
PubMed1981

Determination of 1-beta-D-arabinofuranosylcytosine and 1-beta-D-arabinofuranosyluracil in human plasma by high-performance liquid chromatography.

A method is described for the determination of 1-beta-D-arabinofuranosylcytosine (Ara-C) and its metabolite 1-beta-D-arabinofuranosyluracil (Ara-U) in human plasma. After deproteinization of the plasma sample, separation is performed by reversed-phase liquid chromatography. For Ara-C concentrations exceeding 0.05 mg/l and for Ara-U concentrations exceeding 1 mg/l, injection volumes of 100 microliter are applied. For lower concentrations an injection volume of 500 microliter is used. Ara-C is detected at 280 nm with a lowest detection limit of 0.002 mg/l in plasma. Ara-U is detected at 264 nm with a lowest detection limit varying from 0.01 to 0.1 mg/l in plasma. This variation is caused by an unknown substance with the same elution properties as Ara-U and which appears to be present in plasma in variable concentrations. The coefficient of variation of the whole procedure is about 6% for Ara-C concentrations above 0.005 mg/l and for Ara-U concentrations above 0.1 mg/l. For lower concentrations the coefficient of variation is about 14%.

Arabinofuranosyluracil↗
PubMed1981

Lithium inhibits adenylate cyclase of human platelets.

The ADP-induced aggregation of human platelets is markedly increased after preincubation with lithium chloride, whereas lithium has the opposite effect on rabbit platelets. Since this phenomenon might be related to cAMP metabolism, the influence of lithium on total cAMP content and adenylate cyclase activity was investigated. Lithium does not significantly change the total cAMP content of human platelets neither during incubation nor during ADP-induced aggregation. Basal adenylate cyclase activity, however, was slightly inhibited by lithium in human platelets. The inhibition of adenylate cyclase by ADP appeared to be enhanced by lithium. Prostacyclin induced stimulation of adenylate cyclase is counteracted by this ion. In rabbit platelets the prostacyclin stimulated adenylate cyclase activity is not affected by lithium. These data suggest that a correlation exists between the influence of lithium on the aggregation of human and rabbit platelets and the sensitivity of their adenylate cyclase for this ion.

Adenylyl Cyclase Inhibitors↗
PubMed1981

Simplified method for DNA and protein staining of human hematopoietic cell samples.

A rapid reproducible method yielding high resolution analysis of DNA and protein in human hematopoietic cell samples has been developed by modification of the propidium iodide and fluorescein isothiocyanate procedure. Cell staining involves sequential addition of each reagent (RNase, fluorescein isothiocyanate and propidium iodide) to ethanol-fixed cells and requires no centrifugation steps. Stained cells are analyzed in the reagent solutions. Analysis of bone marrow samples from multiple myeloma patients showed mixed normal and aneuploid populations with a major portion of the aneuploid cells having a significantly higher protein content. This approach permitted differential cell cycle analysis of normal and the aneuploid populations.

Cell Cycle↗
PubMed1981

Spontaneous lymphocyte transformation in relation to the number of circulating lymphocytes in Hodgkin's disease.

Spontaneous lymphocyte transformation in relation to the number of circulating lymphocytes was studied in 54 patients with active Hodgkin's disease. Increased spontaneous DNA synthesis by peripheral lymphocytes was found in 83% of the cases studied. However, no difference was found in comparing a group of lymphopenic patients (less than 1,500 lymphocytes/microliter) to a group with normal lymphocyte count (greater than 1,500 lymphocytes/microliter). Implications of these findings are discussed

DNA↗
PubMed1981

Monocyte purification with counterflow centrifugation monitored by continuous flow cytometry.

Continuous monitoring of cell light scatter during counterflow centrifugation of a mononuclear cell suspension allows counting and size recognition of the cell types elutriated. With this method an optimal separation point between monocytes and lymphocytes, determined for each individual donor, may be established. With a constant flow of 15 ml/min this separation point is found at centrifugal velocities ranging from 2348 to 2444 rpm (n = 10). From 50 ml venous blood, 84.1% +/- 4.1% (15.7 +/- 8.6 x 10(6)) of all elutriated monocytes, with a purity of 92.4% +/- 1.4%, is collected in a volume of 50 +/- 1 ml. In the same run, 92% +/- 4.3% of the lymphocytes is gathered in one fraction with a purity of 98.9% +/- 0.7%. After counterflow centrifugation, 91.6 +/- 10.5% of the cells loaded is recovered; viability exceeds 98%.

Cell Separation↗
PubMed1981

Lithium stimulates thromboxane B2 formation in human platelets.

The aggregation of human platelets is enhanced after preincubations with lithium salts. Previously it was shown that lithium inhibits adenylate cyclase activity in human platelets. Enhancement of aggregation and inhibition of adenylate cyclase by lithium was not observed in rabbit platelets. In this paper it is shown that in human platelets lithium enhances considerably the synthesis of thromboxane B2, whereas the synthesis of PGE2 and PGF2 alpha was enhanced to a lesser extent. In rabbit platelets lithium had no effect on prostaglandin synthesis. It is concluded that lithium specifically stimulates the synthesis of thromboxanes in human platelets, probably due to the previously reported inhibition of adenylate cyclase activity, resulting in an increased aggregability.

Adenosine Diphosphate↗
PubMed1980

High spontaneous thymidine incorporation into a non-T lymphocyte population in Hodgkin's disease unmasked after cell fractionation.

In order to study the nature of the spontaneously stimulated cells in Hodgkin's disease, lymphocytes from 10 patients with Hodgkin's disease and 10 healthy control subjects were separated into low- and high-density fractions. Both fractions were subdivided into T and non T cell populations by means of rosette sedimentation. In Hodgkin's disease patients, non-T cells with a high density showed a significantly increased spontaneous thymidine incorporation (mean, 5677 cpm; range, 405--26490 cpm) compared to corresponding cells from control subjects (mean, 484 cpm; range, 235--850 cpm), and to unseparated high-density lymphocytes in Hodgkin's disease patients. Evidence is presented that in Hodgkin's disease, the high-density lymphocyte fraction comprises non-T cells with an apparent potency for DNA synthesis which is, however, inhibited by T cells present in the same high-density fraction.

Adult↗
PubMed1980

Lymphocyte density distribution profile and spontaneous transformation related to the stage of Hodgkin's disease.

Density distribution profiles of peripheral lymphocytes were made in 41 untreated patients with Hodgkin's disease and in 14 normal controls. The fraction of lymphocytes with a low specific gravity in patients was significantly increased in comparison to normal controls (P=0.0007). These low density lymphocytes in Hodgkin's disease patients showed an elevated spontaneous 3H-thymidine incorporation compared to normal controls (P less than 0.0001). In 78% of the patients the spontaneous DNA synthesis of the low density lymphocytes was above the normal range. A positive correlation (P=0.002) was found between the spontaneous 3H-thymidine uptake and the stage of the disease.

Adult↗
PubMed1980

Spontaneous transformation of low density lymphocytes as parameter of activity in Hodgkin's disease.

Analysis of spontaneous lymphocyte transformation, as measured by 3H-thymidine incorporation by low density lymphocytes, before and after therapy was performed in 28 patients with Hodgkin's disease. Before treatment increased 3H-thymidine uptake was found in 24 out of 28 patients. Following therapy the spontaneous lymphocyte transformation of the patients in clinical remission returned to the normal range, whereas none of the patients with residual disease achieved these levels. The overall correlation between the uptake of the DNA precursor by low density, lymphocytes and disease activity after treatment was excellent.

Adult↗
PubMed1980

Observations on ADP aggregation of lithium chloride incubated platelets in a variety of mammalian species.

In citrated platelet-rich plasma of eight mammalian species lithium produces species-dependent effects on ADP aggregation ranging from stimulation to inhibition. Raising the extracellular calcium concentration enhanced aggregation of both lithium-stimulated and lithium-inhibited platelets, indicating that the extracellular calcium concentration has no direct relation to the effect of lithium on platelet function. Lithium did not induce changes in total intracellular platelet calcium and magnesium contents. Aggregation of platelets with ionophore A23187 showed the same species-specific lithium effects as aggregation induced by ADP. The data suggest that lithium does not exert its effect on platelets through interference with intra- or extracellular calcium concentrations.

Adenosine Diphosphate↗
PubMed1980

A method for quantification of peripheral blood admixture in bone marrow aspirates.

Peripheral blood admixture in bone marrow aspirates of twenty patients with hematologic diseases were studied either with 51Cr labeled autologous erythrocytes or 125I-lab eled albumin. In these bone marrow aspirates 97.0 +/- 4.2% (mean +/- SD) of te hemoglobin content appeared to be derived from peripheral blood. Assuming the presence of a proportional number of peripheral nucleated cells one may calculate the fraction of peripheral nucleated cells in bone marrow aspirates (Fpb) from its hemoglobin levels. The Fpb in the twenty patients studied, varied from 6 to 93%, whereas in a group of 25 healthy volunteers the mean Fpb +/- SD was 14 +/- 8%. In order to obtain reliable results in quantitative bone marrow studies one has to take into account the fraction of peripheral nucleated cells in bone marrow aspirates.

Adolescent↗