The effect of cortisone on the accumulation, activation, and necrosis of macrophages in tuberculous lesions

Effect of prednisolone in vitro on the migration ability of peritoneal macrophages in rats

Prednisolone in vitro decreases the random migration of peritoneal macrophages in non-sensitized rats. In sensitized animals cells are sensitive or resistant to prednisolone's inhibitory action, depending on the presence of antigen in the culture.

Improvement in the histochemical demonstration of acid phosphatase, beta-galactosidase and nonspecific esterase in glycol methacrylate tissue sections by cold temperature embedding

A simple, cold-embedding method (on cracked ice at 2 C) is presented for the demonstration of acid phosphatase, beta-galactosidase and nonspecific esterase in glycol methacrylate tissue sections.

Some effects of products from necrotic regions of tumours on the in vitro migration of cancer and peritoneal exudate cells

The invasion of normal tissues by cancer cells and the infiltration of tumours by macrophages to some degree involves active translatory movements by these cells. As necrosis is a common occurrence in solid tumours, we have studied the interactions of saline extracts from the necrotic regions of rat Walker-256 tumours and mouse Gardner lymphosarcomas on the transmembrane, in vitro migration of Walker and Gardner cancer cells, and rat and mouse peritoneal macrophages. Necrotic extracts enhanced cell migration independently of chemotactic activity, an effect which was partially reduced by Trasylol, an inhibitor of neutral proteases. Rat liver lysosomal preparations which contain lower levels of neutral proteases than necrotic extract, inhibited or had no effects on cell migration, and the lysosomal stabilizer hydrocortisone did not inhibit the action of necrotic extracts. The results indicate that necrosis may enhance the migration of cancer cells out of tumours and the migration of macrophages into them. The extracts act partially through their neutral protease content. In contrast to the enhancement of cell detachment by necrotic extracts, which previous work has shown to be partially mediated by their indirect effect in causing lysosomal labilization and which is partially inhibited by hydrocortisone, this indirect mechanism is not demonstrable in the enhancement of cell migration. The results indicate that the consequences of necrosis are worthy of consideration in attempts at understanding the biology of solid tumours.

The antinflammatory effects of glucocorticosteroids. A brief review of the literature

The effects of glucocorticosteroids on immune and inflammatory responses are reviewed. The steroids seem to change the number or function of cell receptors for regulating agents, so that in areas of inflammation: (a) blood vessels dilate less, (b) lymphocytes proliferate less, (c) all leukocytes infiltrate less, (d) macrophages become less activated (digesting and secreting less), and (e) fibroblasts produce less collagen and ground substance. In addition, the corticosteroids seem to alter the response of cells to various signals from their receptors by affecting the prostaglandin system, cyclic nucleotides, and perhaps other internal mediators.

Histochemical demonstration of enzyme activities in plastic and paraffin embedded tissue sections

Histochemical staining for enzymes is usually performed on frozen sections. This report lists the longer incubation times required to demonstrate esterase, acid phosphatase, beta-galactosidase, and cytochrome oxidase in plastic embedded and ruotine paraffin embedded tissues. The sections embedded in plastic, i.e. water soluble methacrylate (Polyscience's JB-4) and cut at 2 micrometers, were far superior to frozen sections and paraffin embedded sections both in tissue detail and in the localization of the histochemical reaction product.