Mouse myeloid leukemic M1 cells can be induced to differentiate into macrophages and granulocytes in vitro by a protein inducer, differentiation-stimulating factor (D-factor), and by various other compounds. Mouse spleen cells produced D-factors when treated with various mitogens, such as concanavalin A, phytohemagglutinin, pokeweed mitogen, lipopolysaccharide, and synthetic double-stranded pol...

X-irradiation of purified primary cultures of mouse bone marrow stroma or permanent cloned marrow stromal cell lines in plateau phase decreases production of macrophage progenitor cell-specific colony-stimulating factor to a plateau minimum of 40% of control levels after doses of 50 to 500 Gy delivered at 2 Gy/min. After 50 Gy there is increased bioavailability of another growth factor(s) that ...

Mice bearing large (greater than or equal to 3 g) metastatic and nonmetastatic Lewis lung carcinoma (LLC) tumors were studied to determine if the tumor variants differentially induced bone marrow versus splenic hematopoiesis and the appearance of hematopoiesis-associated immune suppressor cells. The metastatic LLC-C3 and nonmetastatic LLC-C8 tumors were equal in their stimulatory effects in viv...

A tentative characterization of haemopoietic stem cells with respect to their organ distribution, seeding fraction and colony formation in the spleen, radiosensitivity and humoral regulation was attempted in mice heterozygous for the mutant allele Slj and in their normal littermates. Slj/+ mice were characterized by a deficient CFU-s content of the blood and spleen and had slightly lower femora...

most common tumors of the spleen are hematologic and lymphoid malignancies. non-lymphoid and non-hematologic tumors of the spleen are very rare, the most common of which are vascular tumors. this group of tumors in the spleen is composed of heterogeneous tumors such as hemangioma, angioendothelioma (ae), littoral cell angioma, and angiosarcoma. there are several histologic forms of ae such as e...

The fitness and virulence costs associated with the clinical acquisition of colistin resistance by Acinetobacter baumannii were evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coi...

The colony-forming unit culture (CFU-C) in the thin-layer agar colony technique is considered to be representative for hemo-poietic stem cells (HSC), according to our studies in mouse and monkey bone marrow. Using this in vitro assay as a guide, stem cell concentrates were prepared from monkey and human bone marrow by repeated density gradient centnfugation. The number of CFU-C could be enriche...

The objective of this study was to investigate the in vivo activity of the lantibiotic lacticin 3147 against the luminescent Staphylococcus aureus strain Xen 29 using a murine model. Female BALB/c mice (7 weeks old, 17 g) were divided into groups (n = 5) and infected with the Xen 29 strain via the intraperitoneal route at a dose of 1 × 10(6) cfu/animal. After 1.5 hr, the animals were treated su...