Oxygen Carriers (“Blood Substitutes”)Raison d'Etre, Chemistry, and Some Physiology Blut ist ein ganz besondrer Saft1

New insights into the ultrastructure and phosphatase localizations of Golgi apparatus and GERL, and into the probable origin of lysosomes in the neurons of fetal dorsal root ganglia and the small neurons of adult ganglia have come from studying thick (0.5–1.0 µ) as well as thin (up to 500 A) sections by conventional electron microscopy. Tilting the thick specimens, by a goniometer stage, has helped to increase our understanding of the three-dimensional aspects of the Golgi apparatus and GERL. One Golgi element, situated at the inner aspect of the Golgi stack, displays thiamine pyrophosphatase and nucleoside diphosphatase activities. This element exhibits regular geometric arrays (hexagons) of interconnected tubules without evidence of a flattened portion (saccule or cisterna). In contrast, GERL shows acid phosphatase activity and possesses small cisternal portions and anastomosing tubules. Lysosomes appear to bud from GERL. Osmium deposits, following prolonged osmication, are found in the outer Golgi element. Serial 0.5-µ and thin sections of thiamine pyrophosphatase-incubated material demonstrate that, in the neurons studied, the Golgi apparatus is a continuous network coursing through the cytoplasm. Serial thick sections of acid phosphatase-incubated tissue suggest that GERL is also a continuous structure throughout the cytoplasm. Tubules of smooth endoplasmic reticulum, possibly part of GERL, extend into the polygonal compartments of the inner Golgi element. The possible physiological significance of a polygonal arrangement of a phosphatase-rich Golgi element in proximity to smooth ER is considered. A tentative diagram of the Golgi stack and associated endoplasmic reticulum in these neurons has been drawn.

https://rupress.org/jcb/article-pdf/50/3/859/1070079/859.pdf

Golgi apparatus, gerl, and lysosomes of neurons in rat dorsal root ganglia, studied by thick section and thin section cytochemistry

1 Separation of Tumor Cells from Fibroblasts.- 2 Development of Media for Isolation and Cultivation of Human Cancer Cells.- 3 New Approaches to the Cultivation of Human Breast Carcinomas.- 4 Old and New Problems in Human Tumor Cell Cultivation.- 5 New Human Tumor Cell Lines.- 6 Human Brain Tumor Cells in Matrix Culture.- 7 Neoplastic Human Glia Cells in Culture.- 8 Current Research with Organ Cultures of Human Tumors.- 9 Metabolic Gradients in Tissue Culture Studies of Human Cancer Cells.- 10 Human Lung Cancer in Tissue Culture.- 11 Cell Lines from Humans with Hematopoietic Malignancies.- 12 Cytological Characterization of Human Tumor Cells from Monolayer Cultures.- 13 Chromosome Abnormalities in Human Tumor Cells in Culture.- 14 Ultrastructural Characteristics of Human Tumor Cells in Vitro.- 15 The Strategy of a Search for Viral Involvement in Human Cancer.- 16 Helper Activity for the Defective Friend Leukemia Virus in Human Malignant Cell Cultures.

Human tumor cells in vitro

Melanosomes are tissue-specific lysosome-related organelles of pigment cells in which melanins are synthesized and stored. Analyses of the trafficking and fate of melanosomal components are beginning to reveal how melanosomes are formed through novel pathways from early endosomal intermediates. These studies unveil generalized structural and functional modifications of the endosomal system in specialized cells, and provide unexpected insights into the biogenesis of multivesicular bodies and how compartmentalization regulates protein refolding. Moreover, genetic disorders that affect the biogenesis of melanosomes and other lysosome-related organelles have shed light onto the molecular machinery that controls specialized endosomal sorting events.

Melanosomes — dark organelles enlighten endosomal membrane transport

Melanosomes are morphologically and functionally unique organelles within which melanin pigments are synthesized and stored. Melanosomes share some characteristics with lysosomes, but can be distinguished from them in many ways. The biogenesis and intracellular movement of melanosomes and related organelles are disrupted in several genetic disorders in mice and humans. The recent characterization of genes defective in these diseases has reinvigorated interest in the melanosome as a model system for understanding the molecular mechanisms that underlie intracellular membrane dynamics.

The melanosome: membrane dynamics in black and white.

The B-16 and Harding-Passey mouse melanomas were studied by light microscopy (tyrosinase, acid phosphatase, aryl sulfatase, thiamine pyrophosphatase and inosine diphosphatase activities) and electr...

Ultrastructural and cytochemical observations on b-16 and harding-passey mouse melanomas the origin of premelanosomes and compound melanosomes:

The peroxidatic activity of hemoglobin permitted visualization of its uptake by rat hepatocytes by means of the Graham-Karnovsky 3,3'-diaminobenzidine (DAB) procedure. Lysosomes were visualized by their acid phosphatase, β-glucuronidase, and glucosaminidase activities. When large doses of rat, cow, or human hemoglobin are intravenously injected, or when hemoglobinemia is induced by injection of distilled water, DAB-positive hemoglobin is engulfed by pinocytosis. Pinocytotic vacuoles become digestive vacuoles ("phagolysosomes") by fusion with lysosomes of the dense body type that have moved from their pericanalicular position. By 16–24 hr after even massive amounts of hemoglobin (400 mg/100 g), the protein is barely demonstrable in hepatocytes. At the lowest doses of injected hemoglobin (15 mg/100 g body weight), DAB-positive vacuoles are demonstrable only in the Kupffer cells.

/pdf/hemoglobin-uptake-by-rat-hepatocytes-and-its-breakdown-1o6meyxy27.pdf

Arline Albala

Papers

Ultrastructural and cytochemical observations on b-16 and harding-passey mouse melanomas the origin of premelanosomes and compound melanosomes:

Hemoglobin uptake by rat hepatocytes and its breakdown within lysosomes.