A case of chronic neutrophilic leukaemia (CNL) is reported. The diagnosis was based on leucocytosis with mature neutrophils, a raised leucocyte alkaline phosphatase score, negative Philadelphia chromosome, and extensive infiltration of neutrophils in various differentiation stages into the bone marrow. When viewed by light microscopy, these neutrophils were almost normal in appearance, except f...

Ultrastructural and functional studies of degranulation responses by human neutrophils have suggested that microtubules (MTs) have a role in the intracellular transport of neutrophil granules. We have found that granule-MT complexes can be isolated from disrupted taxol-treated (1.0 microM) neutrophils, visualized by electron microscopy, and quantified in terms of granules per MT length. After i...

Vaccinia virus (VV) mutants lacking the double-stranded RNA (dsRNA)-binding E3L protein (ΔE3L mutant VV) show restricted replication in most cell types, as dsRNA produced by VV activates protein kinase R (PKR), leading to eIF2α phosphorylation and impaired translation initiation. Here we show that cells infected with ΔE3L mutant VV assemble cytoplasmic granular structures which surround the VV ...

A method has been described for isolation of the specific cytoplasmic granules of rabbit polymorphonuclear leucocytes. Homogeneous suspensions of leucocytes were disrupted by lysis in 0.34 M sucrose. This procedure liberated the cytoplasmic contents of the cell and dissolved a considerable proportion of the nuclei. Following disruption, the sucrose lysate was separated into three fractions by d...

The intracellular flow of tritiated lysine as revealed by electron microscope radioautography was studied in heterophilic myelocytes of rabbit marrow. Label over the Golgi complex rose to a maximum of 37% of total cytoplasmic grains 30 min after initial exposure to the tracer and fell to 11% after 3 to 4 hr of incubation. Coincident with decrease in label over the Golgi complex, grain counts ov...

The previous papers in this series have presented data on the composition of the cytoplasmic granules of rabbit polymorphonuclear leucocytes and on the fate of the granules following particle ingestion (1, 2). These studies demonstrated that the granules contain the bactericidal agent phagocytin and a number of hydrolytic enzymes. Both types of compounds can be liberated in a non-sedimentable, ...

In somatic cells, untranslated mRNAs accumulate in cytoplasmic foci called processing bodies or P-bodies. P-bodies contain complexes that inhibit translation and stimulate mRNA deadenylation, decapping, and decay. Recently, certain P-body proteins have been found in germ granules, RNA granules specific to germ cells. We have investigated a possible connection between P-bodies and germ granules ...

In Drosophila melanogaster and many other metazoans, the specification of germ cells requires cytoplasmic inheritance of maternally synthesized RNA and protein determinants, which are assembled in electron-dense cytoplasmic structures known as germ or polar granules, found at the posterior end of the oocytes. Recent studies have shown that the formation of germ granules is dependent on the inte...

In Caenorhabditis elegans, lack of the conserved germline RNA helicase CGH-1 causes infertility and excessive levels of physiological germline apoptosis, a process that normally claims about half of all developing oocytes. In yeast the CGH-1 ortholog is a key component of degradative "processing (P) bodies," which may share some properties with germline protein-RNA complexes such as P granules....

C. elegans P granules are conserved cytoplasmic ribonucleoprotein complexes that are unique to the germline and essential for fertility. During most of germline development, P granules are perinuclear and associate with clusters of nuclear pores. In an RNAi screen against nucleoporins, we have identified a specific nucleoporin essential for P granule integrity and function. The C. elegans homol...