Wallace N. Jensen

Scanning Electron Microscopy of Thrombogenesis on Vascular Catheter Surfaces

SEVERAL investigations have provided evidence that vascular catheters used for diagnostic and therapeutic measures are not biologically inert but may serve as a nidus for thrombosis.1 , 2 The prese...

Bone-Marrow Mast Cells in Lymphoproliferative Disorders

Increased bone-marrow mast-cell content and lymphoproliferative disorders have been previously linked. Using a semiquantitative method we examined bone-marrow mast-cell content in 120 marrow specimens from patients with multiple myeloma, chronic lymphocytic leukemia, non-Hodgkins lymphoma, and reactive lymphocytosis. Results indicated a statistically significant increase of marrow mast-cell content in patients with chronic lymphocytic leukemia, non-Hodgkins lymphoma, and reactive lymphocytosis when compared with iron-deficient control subjects (p less than or equal to 0.0005). Patients with multiple myeloma had decreased marrow mast-cell content, clearly separating them from patients with lymphoproliferative disorders and reactive lymphocytosis. Linear regression plot of marrow mast-cell content against percentage of marrow lymphocytes showed a direct relation, indicating that marrow mast-cell density may be related more to the degree of lymphoid proliferation than to the specific lymphoproliferative process. Marrow mast-cell content may therefore be reproducibly determined and used to support the morphologic diagnosis of lymphoproliferative disorders and differentiate them from atypical myelomas.

Ultrastructure of the Normal and Hemoglobinopathic Red Blood Cell Membrane: Freeze-Etching and Stereoscan Electron Microscopic Studies

The ultrastructure of the red blood cell membrane and its surfaces is characterized by freeze-etching and stereoscan electron microscopy for the normal red blood cell and cells from patients with sickle cell anemia, hemoglobinopathy CC, and Heinz body hemolytic anemia. The external surface, intramembrane surfaces, and the internal surface of the normal red blood cell are described and the alterations of membranocytoplasmic relationships in the hemoglobinopathies studied are shown.

Microincision of sickled erythrocytes by a laser beam.

Increased mechanical fragility of the sickled red cell is thought to be important in the genesis of the hemolytic process in sickle-cell disease. Sickled cells were observed cinematographically after microincision by a ruby-laser beam. Distortion and charring invariably occurred at the site of injury, and with small injuries there was no further cell change. With larger injuries, variably rapid retraction of spicules occurred accompanied by sphering of the cell. In some cases, progressive loss of hemoglobin accompanied and followed the changes in shape; in others the sphered cell still contained hemoglobin. Regardless of the mecha nisms involved in these changes in vitro, the observations may be applicable to destruction of sickled cells in vivo. We suggest that the cells are subject to avulsion of rigid cellular processes as a result of mechanical injury incurred in normal circulation. Such injured cells may undergo either immediate hemolysis or trans formation into spherocytes which are subject to erythophagocytosis.

Studies on rat reticulocyte polysomes during in vitro maturation.

Abstract The polysomes of reticulocytes undergo a progressive breakdown during in vitro incubation of the cells. The breakdown was approximately 30% after 5 hours incubation, 75% after 10 hours, and 92% after 18 hours. The addition of actinomycin to the in vitro maturation system does not change the pattern of polysome breakdown and does not produce inhibition of incorporation of l -leucine-C 14 into polypeptide chains initiated on polyribosomes or into soluble protein. In contrast, lead acetate (5.7 × 10 −5 M ) added to the maturation system caused a 40% breakdown of polysomes in 1 hour and a 72% breakdown in 5 hours. There was inhibition of incorporation of l -leucine-C 14 into polypeptide chains initiated on polysomes and into soluble proteins. The presence of puromycin (2.52 × 10 −4 M ) in the maturation system produced rapid breakdown of polysomes and an almost total inhibition of incorporation of l -leucine-C 14 into proteins. Cycloheximide (8.46 × 10 −4 M ) produced a 46% breakdown of polysomes in 1 hour and almost complete inhibition of incorporation of labeled amino acids into polypeptides.

IN VITRO INCORPORATION OF RADIOPHOSPHORUS INTO THE PHOSPHATIDES OF NORMAL HUMAN BLOOD CELLS.

Summary The incorporation of P32 into the phosphatides of the formed elements of normal human blood has been measured. A characteristic pattern was described for eryth-rocytes, leukocytes and platelets. Radiophos-phorus is incorporated into red cell phospha-tidic acid. The variable and high rates of incorporation of P32 into certain phosphatides of red cells, white cells and platelets would indicate the necessity of assessing this function by these cells when making such measurements in whole blood.

An Evaluation of Depleted Iron Stores in a Series of 1,332 Needle Biopsies of Marrow.

Excerpt Consecutive unselected bone marrow sections obtained by a modified needle biopsy procedure were examined for iron stores using the Prussian blue reaction. The sections obtained by this meth...