Angiogenesis assays: a critical overview.

Background: Angiogenesis, the formation of new blood vessels, is an integral part of both normal developmental processes and numerous pathologies, ranging from tumor growth and metastasis to inflammation and ocular disease. Angiogenesis assays are used to test efficacy of both pro- and antiangiogenic agents.

Methods: Most studies of angiogenesis inducers and inhibitors rely on various models, both in vitro and in vivo, as indicators of efficacy.

A ribonuclease inhibitor expresses anti-angiogenic properties and leads to reduced tumor growth in mice.

Our experiments were designed to determine whether recombinant ribonuclease inhibitor (RNasin) could inhibit angiogenesis and reduce tumor growth in adult mice. We used the Fajardo disc angiogenesis assay as the primary means of measuring new blood vessel growth. This assay measures the penetration of cells into a polyvinyl alcohol sponge with a central core of ELVAX-coated sponge containing test substances.

An immune model of beryllium-induced pulmonary granulomata in mice. Histopathology, immune reactivity, and flow-cytometric analysis of bronchoalveolar lavage-derived cells.

Background: Beryllium compounds can cause acute and chronic lung injury in humans. Although models of chronic granulomatous lung disease have been established in various animal species, a murine model of beryllium-induced chronic lung disease has not been established.

Experimental Design: Beryllium was introduced intratracheally either as a soluble salt (BeSO4) or in particulate form (BeO).

In vitro differentiation of mouse embryonic yolk sac cells.

The embryonic yolk sac is the first site in the mammalian embryo in which cells are found that can carry out cell-mediated immune functions, yet the relation of cells of this primitive hematopoietic organ to the development of the mature immune system has not been established. We have initiated a series of experiments to determine the potential of cells of the mouse yolk sac to differentiate in vitro, in order to get an insight into the development of immunocompetence in this primary population of hematopoietic stem cells. The present paper describes the conditions promoting stem-cell differentiation and provides an initial characterization of cell surface phenotypes of the cell lineages established in vitro.

A new source of embryonic lymphocytes in the mouse.

The source of stem cells within the early mammalian embryo has not been identified. The yolk sac, once thought to provide the early stem cells in birds, is now seen more as a primitive effector organ capable of allorecognition, natural cytotoxic reactions and elaboration of cytokines. In lower vertebrates the source appears to be within a region delineated by the anterior limbs, foregut and mesonephros.