Elimination of T lymphocytes from the bone marrow in HLA-incompatible bone marrow transplantation

The method presented is very well suited to eliminate T-lymphocytes from great amounts of bone-marrow. The stem cells required to reconstitute the bone-marrow are enriched in this way. It can be completely performed in a closed system. Any contamination with germs is excluded. It can be reproduced well and learnt quickly. It takes 10 hours for two trained co-workers to process 1,500 ml of bone-marrow. The vitality of cells is very good (100%). Its suitability for transplantation has still to be checked.     

Isolation of mitochondria from rat brain using Percoll density gradient centrifugation

We have developed procedures that combine differential centrifugation and discontinuous Percoll density gradient centrifugation to isolate mitochondria from rat forebrains and brain subregions. The use of Percoll density gradient centrifugation is central to obtaining preparations that contain little contamination with synaptosomes and myelin. Protocols are presented for three variations of this procedure that differ in their suitability for dealing with large or small samples, in the proportion of total mitochondria isolated and in the total preparation time. One variation uses digitonin to disrupt synaptosomes before mitochondrial isolation. This method is well suited for preparing mitochondria from small tissue samples, but the isolated organelles are not appropriate for all studies. Each of the procedures produces mitochondria that are well coupled and exhibit high rates of respiratory activity. The procedures require an initial setup time of 45-75 min and between 1 and 3 h for the mitochondrial isolation.     

Comparative studies of galactokinase activity on mammal's red blood cells.

1. ATP: D-galactose-1-phosphotransferase activity was measured in human, pig, cow, rabbit, mouse and rat red blood cells. Mean values of galactokinase activity was markedly lower in the human and pig erythrocyte as compared to those of the other species. 2. The permeability to galactose of the red cells studied was always higher than galactose phosphorylation. 3. The affinity constants of galactokinase for galactose ranged from 119 to 291 microM and from 178 to 406 microM for ATPMg2-. 4. The thermostability values of the galactokinase of the species studied were similar. The pH-optimum is pH 7.5 for the human, mouse and rabbit enzyme and pH 8.0 for cow, pig and rat galactokinase.     

Dielectric properties of human red blood cells in suspension at radio frequencies

Dielectric properties of human red blood cells (RBCs) in suspension (hematocrit 50%) from 243 healthy persons (120 males, 123 females) were measured at 25 °C in a frequency range of 1–500 MHz, with a coaxial transmission line reflection method (one-side measurement). The measuring system, controlled by an IBM-PC computer, was composed of a network analyzer (HP4195A), an impedance test adapter (HP41951-61001), a coaxial line sensor, and a temperature-controlling set. The data measured revealed a statistically significant age dependence, with a critical age of about 49 years, above which permittivity and conductivity of human RBCs in suspension decreased significantly. © 1994 Wiley-Liss, Inc.     

Rapid purification of ferritin from lysates of red blood cells using proteinase-K

A simple, rapid, and novel procedure for purifying ferritin from the postnuclear supernatant of red blood cell lysates is described. This report establishes the resistance of commercially available holo- and apo-ferritins to proteinase-K digestion, and documents how the use of this enzyme, in conjunction with the well-documented resistance of ferritins to heat denaturation (75-80 degrees C for 10 min), makes it possible to obtain high yields (greater than 90%) of pure, undegraded ferritin from the postnuclear supernatant of hypotonically or Triton X-100 lysed red blood cells. The resultant purified ferritin contains the same amount of iron as ferritin not treated with proteinase-K and, as judged by one- and two-dimensional gel electrophoresis and electron microscopy, consists of intact ferritin with a subunit isoform composition identical in molecular mass and isoelectric points to that obtained from ferritin prepared in the absence of this enzyme.