Biomedical subjects

J B Smeulders

Publications and source records attributed to J B Smeulders.

5 recordsLinked to original sources

PubMed1984

Lymphocyte isolation from human spleen by counterflow centrifugation employing two different flow chambers on line.

Studies on splenic lymphocytes have hitherto been performed on single cell suspensions depleted of phagocytic cells by adherence to plastic or incubation with carbonyl iron. These techniques have the disadvantages of selective cell loss, suboptimal cell purification and cell activation. This paper describes purification of splenic lymphocytes by the use of counterflow centrifugation (CFC). The method was adapted to overcome pelleting of cells in the separation chamber to form a plug at the inlet and impede adequate flow. By combining 2 different separation chambers on line in 1 rotor this problem was overcome. Of all lymphocytes recovered after CFC 88.8 +/- 1.4% were collected in 2 pooled fractions with a purity of greater than or equal to 98% and a cell viability of 95%. After CFC, 80.8 +/- 12.1% of the viable cells loaded were recovered.

Blood Platelets↗

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↗

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↗

PubMed1979

Non-selective lymphocyte isolation from human blood by nylon wool filtration and density centrifugation.

A new method was employed to isolate lymphocytes from human peripheral blood. Continuous flow filtration through a nylon wool filter, at a flow rate of 1.4 ml/min, produced a lymphocyte yield of 90.5% and a purity of 96% without any shift in the B-T cell ratio. Ficoll-Isopaque with a specific gravity of 1.085 g/ml instead of 1.077 g/ml could be used to remove the erythrocytes. An overall recovery, including defibrination, filtration, Ficoll-Isopaque centrifugation and washing step, of 74.5% was achieved.

B-Lymphocytes↗