Sarcomas arising after radiotherapy for peptic ulcer disease.

Therapeutic gastric irradiation has been used to reduce peptic juice secretion in patients with peptic ulcer disease. Between 1937 and 1968 a total of 2049 patients received such therapy at the University of Chicago. Three of these patients are known to have developed sarcomas in the field of radiation.

Immunohistochemical localization of apolipoprotein B in human atherosclerotic lesions.

A peroxidase-antiperoxidase immunohistochemical method was used to detect the presence of intracellular and extracellular apolipoprotein B (apo B) in paraffin sections of human abdominal aortas and coronary arteries with and without atherosclerotic involvement. The four aortas studied disclosed both intracellular and extracellular apo B in areas in which lipid was found by oil red O staining. Coronary arteries also demonstrated abundant extracellular apo B but failed to disclose intracellular apo B in cells with stainable lipid.

Identification of macrophages in sections of rabbit lung using acetoacetylated lipoproteins.

Macrophages were labeled in sections of rabbit lung with acetoacetylated low density lipoprotein (LDL), a marker internalized by cultured macrophages but not by other connective tissue cells. Using a modified technique, thin slices of fresh rabbit lung were incubated in 3,3'-dioctadecylindocarbocyanine (DiI)-labeled, acetoacetylated LDL, fixed in paraformaldehyde, and sectioned. Alveolar macrophages incorporated the fluorescently labeled, modified LDL, but surrounding stroma and parenchyma did not stain.

An avidin-biotin-peroxidase method for Fc receptors on macrophages isolated from and in sections of rat lung.

Receptors for the Fc region of immunoglobulin G (Fc receptors) were detected on pulmonary macrophages by adapting an avidin-biotin-peroxidase technique to isolated cells and sections of rat lung. After incubation with soluble rabbit immunoglobulin G (IgG), surface bound IgG was identified consistently and reproducibly on glass-adherent pulmonary macrophages and on macrophages in tissue sections made from incubated lung slices. Control experiments indicated that binding was specifically mediated by surface Fc receptors.

Immunophagocytic properties of retinal pigment epithelium cells.

Retinal pigment cells were dislodged from normal monkey eyes and incubated in glass-slide chambers. All viable pigment cells adhered strongly to glass. They demonstrated surface receptors for the Fc portion of immunoglobulin G and for the third component of complement by selectively binding and phagocytizing antibody or complement-coated erythrocytes.

Acid lipase: a histochemical and biochemical study using triton X100-naphtyl palmitate micelles.

Hydrolsis of a-naphtyl palmitate dispersed with the detergent Triton X-100 at acid pH was studied by a histochemical diazocoupling technique in both fixed sections and cultures of primate tissues as well as by a biochemical assay employing the same chromogenic substrate. Evidence for the exclusive hydrolysis of this artificial fatty acid ester substrate by acid lipases was gathered from (1) comparison of isoelectric focusing zymograms developed with different substrates, (2) kinetic analysis of enzyme activity in the presence or absence of inhibitors, including a natural substrate of acid lipase, trioleylglycerol, (3) specific localization of marked enzyme activity in certain tissues, and (4) absence of detectable enzyme activity in a case of human acid lipase deficiency (Wolman's disease). Histochemically, acid lipase activity was most readily detected in cells active in the uptake and processing of neutral lipids, i.