Ectopic production of prostate specific antigen by a breast tumor metastatic to the ovary

We have recently reported that about 30% of breast tumors produce prostate specific antigen (PSA). We examined here, 99 primary ovarian cancer tumors and found relatively low levels of PSA in only three tumors. One patient with metastatic ovarian cancer from a primary breast tumor, produced relatively high levels of PSA and responded well to antiestrogen treatment although she was steroid receptor-negative. Another patient with metastatic ovarian cancer from a primary breast tumor did not produce PSA and did not respond to treatment although she was steroid hormone receptor-positive. This data describe for the first time, ectopic PSA production by a breast tumor at the ovarian metastatic site and further support the view that PSA is a favourable prognostic indicator in breast cancer. © 1994 Wiley-Liss, Inc.     

Selective damage to erythroblasts by 55-Fe

The low energy and short range of 55-Fe Auger electrons were utilized in mice to deliver lethal intracellular radiation to iron-incorporating erythropoietic precursors with minimal radiation damage to other bone marrow cells. The ensuing intramedullary, selective erythropoietic death was demonstrated by absolute and differential bone marrow cell counts and by decreased blood uptake of 59-Fe. The decreased number of colony-forming units in spleen colony assay and the decreased ability of tranplanted bone marrow to protect fatally irradiated mice shows that the bone marrow was partially depleted of pluripotent stem cells. These data are interpreted to indicate an increased pluripotent stem cell utilization in response to increased demand for differentiation of stem cells along the erythropoietic pathway.     

Radioimmunoassay of digoxin in serum using monoclonal antibodies and assessment of interference by digoxin-like immunoreactive substances

We used 7 monoclonal antibodies (MoAbs) and one polyclonal antibody to develop radioimmunoassays (RIAs) for digoxin in serum or plasma. These RIAs were tested for measuring apparent digoxin concentrations in serum from patients receiving the drug, from normal individuals, and in cord blood plasma. We found that two MoAbs cross-reacted significantly with substances in cord blood. The magnitude of cross-reactivity was dependent on the incubation time and temperature. Under equilibrium conditions, one antibody gave apparent digoxin values in cord blood plasma averaging 2.15 ng/ml. We suggest that this cross-reactivity is partially due to progesterone and 17-hydroxyprogesterone in cord blood plasma. The antibody that shows high cross-reactivity with digoxin-like immunoreactive substances may prove a useful tool for studies dealing with characterization of the cross-reacting compounds.     

Determinants of acquisition of MR imaging units in an era of prospective payment

A survey was undertaken to examine the impact of Medicare's Prospective Payment System (PPS) and other recent changes in the health care environment on providers' decisions regarding acquisition of high-cost technologic equipment. The survey group included 199 hospitals and freestanding imaging centers known to have acquired magnetic resonance (MR) imaging units, as well as a random sample of 400 hospitals whose acquisition decisions were unknown to the authors. Fifty-eight percent of the known adopters and 61% of the randomly selected hospitals responded to the survey. Nonadopters' decisions were dominated by economic considerations, including the high cost of MR imagers and concerns about Medicare's reimbursement policies. Competition and a desire to provide the highest quality of care are counterbalancing the retardant effects of PPS, however, and are stimulating widespread diffusion of MR imagers.     

Expression of human Kallikrein 14 (KLK14) in breast cancer is associated with higher tumour grades and positive nodal status

Human kallikrein 14 (KLK14) is a steroid hormone-regulated member of the tissue kallikrein family of serine proteases, for which a prognostic and diagnostic value in breast cancer has been suggested. To further characterise the value of KLK14 as a breast tumour marker, we have carefully analysed KLK14 expression in normal breast tissue and breast cancer both on the RNA level by real-time RT-PCR (n = 39), and on the protein level (n = 127) using a KLK14-specific antibody for immunohistochemistry. We correlated KLK14 protein expression data with available clinico-pathological parameters (mean follow-up time was 55 months) including patient prognosis. KLK14 RNA expression as quantified by real-time RT-PCR was significantly more abundant in breast tumours compared to normal breast tissue (P = 0.027), an issue that had not been clarified recently. Concordantly with the RNA data, cytoplasmic KLK14 protein expression was significantly higher in invasive breast carcinomas compared to normal breast tissues (P = 0.003). Furthermore, KLK14 protein expression was associated with higher tumour grade (P = 0.041) and positive nodal status (P = 0.045) but was not significantly associated with shortened disease-free or overall patient survival time in univariate analyses. We conclude that KLK14 is clearly overexpressed in breast cancer in comparison to normal breast tissues and is positively associated with conventional parameters of tumour aggressiveness, but due to a missing association with survival times, the use of KLK14 immunohistochemistry as a prognostic marker in breast cancer is questionable.