Albert J. Dalton

Identification of molecular ferritin in homogenates and sections of rat liver.

Dense particles, approximately 55 A in diameter, were observed in fractions isolated by high-speed centrifugation from rat liver homogenates. These were identified as the iron-containing micelles of ferritin. Similar particles were observed in thin sections of intact liver cells. They increased greatly in number following the administration of iron to the animals.

CYTOPLASMIC CHANGES DURING CELL DIVISION WITH REFERENCE TO MITOCHONDRIA AND THE GOLGI SUBSTANCE

After the discovery bf the mitochondria by Flemmingl and Altmand and the long series of papers demonstrating that the mitochondria are practically omnipresent in living cells: many investigations were made in an effort to determine their functional significance. Nothing definite may be concluded from this early work except that mitochondria are possibly concerned in some way with respiratory activity of the cytopla~m.~ Similarly, since the discovery of the Golgi substance by Golgi in 1898,5 numerous attempts have been made to determine its significance, the most successful being those of Bowen,6 dealing with spermatogenesis. While his work indicated that the Golgi substance is concerned with the formation of the acrosome during maturation of the sperm, the signilicance of this cytoplasmic component in mature cells of other types has not been clearly defined. The most generally accepted hypothesis is that it serves as an area for the segregation and accumulation of the products of secretory or excretory activity of the ell.^-^ Included in this early work were a few studies on the mitochondria and Golgi substance during cell division. Cowdry12 found no significant change in mitochondria1 number during cell division in embryonic cells, and LudfordL3 demonstrated fragmentation and dispersion but not disappearance of the Golgi substance during mitosis in tumor cells. Recent studies on the detailed morphology of mitochondria117 and the Golgi substance 11, l8 and on the chemical characterization of mitochondrialg give further evidence that both of these cellular components play an important role in cellular metabolism. The presence of a mitochondrial membrane,L4-17 the extreme sensitivity of mitochondria to changes in osmotic pressure,l and the fact that they are apparently the sole carriers of certain

Virus-Like Particles in a Patient with Chronic Lymphocytic Leukemia

THE presence of viruses in the plasmas of laboratory animals with induced leukemia stimulated interest in attempts to find similar particles in the plasma of patients with leukemia. Previous report...