Ploidy and S-phase fractions (SPF) of primary breast cancers and their nodal metastases.

Ninety-one cases of primary breast cancers and their nodal metastases were examined with DNA flow cytometry. No differences were found between the stemline distributions in the primary tumors and nodal metastases. At both sites stemlines clustered around a DNA index of 1.0 (33-40% of cases) and 1.8. The mean S-phase fractions were 7.9 in primary tumors versus 5.6% in nodal metastases (p = 0.02); this difference was also observed if the analysis was restricted to cases with DNA aneuploidy at both sites (10.2 versus 7.6%, p = 0.04). Our results indicate that axillary nodal ploidy and proliferation reflect primary tumor characteristics rather than displaying changes associated with selection during the lymphatic metastatic process. Lymph nodes may have a suppressive effect on the proliferation of tumor cells.

An improved method for the immunocytochemical detection of bromodeoxyuridine labeled nuclei using flow cytometry.

A new staining protocol is described for the immunocytochemical detection of BrdUrd labeled nuclei. Pepsin treatment of ethanol fixed cells or tissue, followed by DNA denaturation at low pH, resulted in increased sensitivity of BrdUrd staining comparable to the thermal denaturation protocol, and decreased background binding. This technique is applicable to cell suspensions, including cultured cells and bone marrow cells. Furthermore, pepsin digestion of ethanol fixed tissue fragments resulted in a high recovery of nuclei in which incorporated BrdUrd could be detected. This possibility, together with the high sensitivity, make this method especially suitable for cell kinetic studies of human solid tumors in vivo.

FMRF-amide immunoreactivity in the mammalian gastroenteropancreatic neuroendocrine system.

The presence of FMRF-amide, a cardioactive tetrapeptide, was studied by immunocytochemistry in human and rat gastric antrum and pancreas, and in the ovine, bovine, canine and rabbit pancreas. In human and rat gastric antrum, numerous cells contained FMRF-amide immunoreactive material. By staining of serial sections and by double staining, colocalization of immunoreactivity for gastrin and FMRF-amide was observed in part of the gastrin cells. In the pancreas of these and the other species, immunoreactivity for FMRF-amide was located both in acinar and islet endocrine cells. Colocalization of FMRF-amide and pancreatic polypeptide was found in a proportion of pancreatic polypeptide cells in the pancreas. FMRF-amide immunoreactivity never colocalized with the other neurohormonal peptides which occur in the gastric antrum and the pancreas. Our observations show that neuroendocrine cells occur in the gastric antrum and pancreas which are exclusively immunoreactive or gastrin and for pancreatic polypeptide respectively. In addition cells occur which show immunoreactivity for FMRF-amide as well as for gastrin in the gastric antrum and with antiserum to FMRF-amide as well as for pancreatic polypeptide in the pancreas. It is concluded that FMRF-amide antibodies probably recognize a substance in G and PP cells which is not identical but may be structurally related to gastrin and pancreatic polypeptide.

Growth hormone releasing factor (GRF) immunoreactivity in human and rat gastrointestinal tract and pancreas.

Rabbit antisera were raised against a synthetic growth hormone releasing factor, which was originally isolated from a human pancreatic endocrine tumor (hpGRF-44). The antisera obtained showed no significant cross-reactivity with a variety of neurohormonal peptides. In addition to its occurrence in the human, but not in the rat, hypothalamus, hpGRF-44-like immunoreactivity was identified in human gastric antrum and human as well as rat pancreatic islets, using an indirect immunoperoxidase technique. Staining of serial sections and double staining revealed that in the gastric antrum the immunoreactivity was largely confined to gastrin (G) cells, whereas in pancreatic islets polypeptide (pp) cells were reactive. The physiological significance of these findings remains to be established.