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Biomedical subjects

J Frei

Publications and source records attributed to J Frei.

At least 55 records · Page 3Linked to original sources
PubMed1977

Leucocyte energy metabolism. VI. Simultaneous and improved isolation of lymphocytes and polymorphonuclear leucocytes from a single of human blood.

A technique, which combines a Ficoll-Rompacon treatment, sedimentation in a Dextran medium and erythrolysis by NH4C1, permitting the simultaneous isolation of polymorphonuclear cells (PMN) and lymphocytes from a single sample of human blood is described. The contamination of the PMN suspensions by other blood cells, including other categories of white cells, is minimal. However, the lymphocyte preparations, free of other white cells, are still contaminated by a non-negligible amount of thrombocytes. It could be shown that the biochemical system studied, the functional behavior and the morphological state of these cells are similar to that of white cells purified with the procedures previously used. Further, a numeration technique, based on DNA estimation, is presented which can be used when the cell count becomes inaccurate by cell agglutination.

Cell Separation↗
PubMed1977

The energy metabolism of the leukocyte. IX. Changes in the concentration of the coenzymes NAD, NADH, NADP, and NADPH in polymorphonuclear leukocytes during phagocytosis of Staphylococcus albus and due to the action of phospholipase C.

The determination of the coenzymes NAD+, NADH, NADP+ and NADPH, by the use of a method of enzymatic cycling, demonstrates that the enzymes responsible for the stimulations found during the phagocytosis of Staphylococcus albus are NADH and NADPH oxidase of human leukocytes and NADPH oxidase in the case of guinea pig leukocytes. The effects of serum, of the bacterial strain used and of phospholipase C are also discussed.

Animals↗
PubMed1977

Leucocyte energy metabolism. VII. Respiratory chain enzymes, oxygen consumption and oxidative phosphorylation of mitochondria isolated from leucocytes.

A new method for the destruction of cell membrane with heparin and for the subsequent isolation of mitochondria from different types of leucocytes (polymorphonuclear leucocytes (PMN) and lymphocytes of human blood, PMN and macrophages of guinea pig peritoneal exudates) is presented. This method is less traumatic to the mitochondria than the usual mechanical procedures. The activites of several enzymes of the respiratory chain were estimated. Oxygen consumption was measured with oxyhaemoglobin as oxygen donor and reaction rate indicator. The integrity of the mitochodria can be demonstrated by the determination of the acceptor control index; the existence of a coupled phosphorylation of ADP to the respiration is clearly demonstrated in all type of cells studied; the ADP/O ratios with several substrates, near to the theoretical values, could be estimated in mitochondria preparation of lymphocytes (normal and leukaemic) and of macrophages. The highest oxidative ratios were found in leukaemic cells.

Animals↗
PubMed1975

Leucocyte energy metabolism. V. Glycolytic and hexose monophosphate shunt enzymes in leucocytes from adults and newborn infants.

The activities of ATP-consuming and ATP-producing steps of the Embden-Meyerhof pathway, as well as other glycolytic enzymes (phosphoglucomutase and enolase) and glucose-6-phosphate dehydrogenase are lower in leucocytes from cord blood than in white cells from adults. These results are related to previous observations (reduced anaerobic glycolysis and nitroblue tetrazolium-test in leucocytes from newborn infants) and discussed in connection with the fact that newborn infants are more susceptible to infections than normal adults.

Adult↗
PubMed1975

[Enzyme system and coenzymes involved in the energy metabolism of leukocytes. Function and metabolism of polymorphonuclear neutrophils].

Mitochondria may be isolated from various types of leukocyte (neutrophil polymorphs and lymphocytes from human blood, neutrophil polymorphs and macrophages from peritoneal exudates of the guinea pig) after destruction by heparin of the cell membrane. This procedure is very simple and less traumatic for these subcellular structures than the usual mechanical procedures. The enzyme activities of the respiratory chain and oxygen consumption may be measured in these mitochondrial preparations. The oxygen consumption is determined using oxyhemoglobin which serves both as oxygen donor, as in the respiratory system in vivo, and as indicator of the reaction at 435.8 nm. The integrity of the mitochondria may be demonstrated by determination of the "acceptor control index", the existence of ADP phosphorylation coupled with oxygen consumption (phosphorylating oxidation) was proved in all the cells studied even if the ADP/O ratio can only be calculated for certain of them (lymphocytes, macrophages). In these cases, the ratios obtained are close to theoretical values whatever the oxidation substrate used. The mitochondria of leukemic cells have a higher oxidation activity than the corresponding reference cells. Determination of leukocyte coenzymes by enzyme cycling (NAD, NADH, NADP, NADPH) showed the following facts: -- Generally, the NAD concentrations remain constant, those of NADH increase whilst those of NADP and NADPH fall during incubation of neutrophil polymorphs in Dulbecco's medium. -- The metabolic changes observed during S. albi heat-induced endocytosis are in favour of simultaneous stimulation of NADH oxidase and NADPH oxidase in human polymorphs, and of NADPH oxidase in the corresponding cells of peritoneal exudates in guinea pigs.

Adenosine Triphosphate↗