Education and training for radiation scientists: radiation research program and American Society of Therapeutic Radiology and Oncology Workshop, Bethesda, Maryland, May 12-14, 2003.

Current and potential shortfalls in the number of radiation scientists stand in sharp contrast to the emerging scientific opportunities and the need for new knowledge to address issues of cancer survivorship and radiological and nuclear terrorism. In response to these challenges, workshops organized by the Radiation Research Program (RRP), National Cancer Institute (NCI) (Radiat. Res.

The practice of causal inference in cancer epidemiology.

Causal inference is an important link between the practice of cancer epidemiology and effective cancer prevention. Although many papers and epidemiology textbooks have vigorously debated theoretical issues in causal inference, almost no attention has been paid to the issue of how causal inference is practiced. In this paper, we review two series of review papers published between 1985 and 1994 to find answers to the following questions: which studies and prior review papers were cited, which causal criteria were used, and what causal conclusions and public health recommendations ensued.

A statistical model validating triage for the peer review process: keeping the competitive applications in the review pipeline.

Triage of grant application at the National Institutes of Health (NIH) is a process whereby an initial screening of applications by a scientific peer review group eliminates applications that are not competitive for awards. The process of application triage has been limited to those applications submitted to the NIH in response to an RFA (Request for Applications). A hypergeometric model was developed to determine the extent to which five, six, seven, or eight member triage teams or subsets of 12-to-20 member full committees could provide a statistically defensible triage decision.

Androgen receptors in biopsy specimens of prostate adenocarcinoma. Heterogeneity of distribution and relation to prognostic significance of receptor measurements for survival of advanced cancer patients.

Needle biopsy specimens of primary adenocarcinoma and surgical specimens of carcinomatous nodal tissue were obtained from previously untreated clinical D stage prostatic adenocarcinoma patients. Assessment of the relation between specimen androgen receptor site content and survival using either scatterplots or Kaplan-Meier analyses showed specimen receptor content was a poor prognostic P greater than 0.1, of survival subsequent to orchiectomy or diethylstilbestrol (DES) therapy.

Immunocytochemical assay of estrogen receptors in endometrial carcinoma with monoclonal antibodies. Comparison with biochemical assay.

Specimens of endometrial adenocarcinoma, surgically obtained from 18 women, were analyzed for distribution of estrogen receptors by an immunocytochemical assay, employing monoclonal anti-estrophilin antibodies and the peroxidase-antiperoxidase technique. Results were compared with biochemical receptor analyses, and were in concordance in 83% of them. Marked tumor cell and tissue receptor heterogeneity were apparent with the immunocytochemical method, and a variety of patterns of nuclear staining in positive tissue samples were revealed.

Biochemical and morphological characterization of clonal AXC rat prostate cancer cells.

We used three heterogeneous parental cultures of LSC-AXC rat prostate cancer cells: LSC-AXC-C/O, cells maintained on culture medium; LSC-AXC-D/O, cells maintained on culture medium containing 10(-7) M 5 alpha-dihydrotestosterone; and LSC-AXC-T/O, cells maintained on culture medium containing 10(-7) M testosterone, to isolate clonally derived cell lines. Eleven of 15 clonal cell lines were tumorigenic when inoculated into intact male AXC rats. Eight tumorigenic clonal cell lines were selected for further evaluation, and all were found to possess features characteristic of secretory epithelium, as judged by light and electron microscopy.

Inability of cytoplasmic or nuclear androgen receptor content or distribution to distinguish benign from carcinomatous human prostate.

We used exchange saturation analysis at 15 degrees to quantitate total cytoplasmic and nuclear androgen receptor content of 70 patient specimens. Cytoplasmic androgen receptor contents (fmol/mg DNA) for eight specimens of clinically benign hyperplasia, 14 specimens of histologically hyperplastic prostate obtained at cystoprostatectomy, and carcinomatous and noncarcinomatous prostate obtained at radical prostatectomy for prostatic carcinoma, 48 specimens, respectively, were 830 +/- 165 (mean +/- S.E.

Human prostate androgen receptor quantitation: effects of temperature on assay parameters.

When cytoplasmic extracts of human prostatic tissues were split to permit quantitation of total androgen receptor (RCT) content by saturation analysis at 15 degrees and 2 degrees, we observed that 30% (10 of 32) of the specimens yielded statistically increased values for RCT following incubation at 15 degrees as compared to 2 degrees. Considering only those specimens (13 of 32) showing statistically differentiated RCT yield, 77% (10 of 13) yielded greater RCT content following incubation at 15 degrees. The families of association constants (Ka) obtained for RCT determinations at 2 degrees and 15 degrees were not statistically differentiated.

Uridine 5'-phosphate photohydrate formation in irradiated Escherichia coli 30S ribosomes: photochemistry and relation to ribonucleic acid-protein cross-linking.

Irradiation of aqueous buffered solutions of Escherichia coli 30S ribosomes with doses of 254-nm radiation greater than 10(19) quanta causes formation of uridine 5'-phosphate (UMP) photohydrates in ribosomal 16S RNA (rRNA). The number of molecules of UMP photohydrate formed at doses less than 2 x 10(20) quanta is linearly dependent on dose of absorbed 254-nm radiation. Maximum UMP photohydrate formation is dependent on initial ribosome concentration.

Studies of the effects of ultraviolet radiation on the structural integrities of ribosomal RNA components of the Escherichia coli 50S ribosomal subunit.

The effects of 254-nm radiation on the structural integrities of free and 50S ribosome-bound 5S and 23S ribosomal ribonucleic acids (rRNA) have been elucidated. Irradiation of aqueous solutions of Escherichia coli 50S ribosomes with 253.7-nm radiation results in the formation of single-strand breaks in double-stranded regions of the 23S rRNA component, but not in rRNA chain scission, and destabilization of the secondary structure of the 23S rRNA toward denaturation.

Demonstration of ribosome-dependent photoinduced chain breakage of the 16S ribosomal ribonucleic acid component of the Escherichia coli 30S ribosomal subunit.

The effects of 253.7-nm radiation on the structural integrities of free and ribosome-bound 16S ribosomal ribonucleic acid (rRNA) have been elucidated. Exposure of aqueous solutions of Escherichia coli 30S ribosomal subunits to 253.

Analysis of the kinetics of photoinduced crosslinkage of the protein and RNA components of the Escherichia coli 50 S ribosomal subunit.

The kinetics of photoinduced crosslinkage of the protein and ribosomal RNA components of the Escherichia coli 50 S ribosomal subunit were determined by two-dimensional gel electrophoresis. One group of ribosomal proteins was found to be reactive in the crosslinkage reaction at doses of 254 nm radiation of 2.9 X 10(3) ergs-mm-2.

Photoinduced cross-linkage, in situ, of Escherichia coli 30S ribosomal proteins to 16S rRNA: identification of cross-linked proteins and relationships between reactivity and ribosome structure.

The kinetics of photoinduced cross-linkage of Escherichia coli 30S ribosomal proteins to the 16S-rRNA molecule in the intact Escherichia coli 30S ribosomal subunit was studied in this report. All of the 30S ribosomal proteins become cross-linked to the 16S rRNA before changes in the sedimentation characteristics of the 30S ribosomal subunit can be detected. The proteins exhibit different reactivities in the cross-linkage reaction.

Evidence for photoinduced cross-linkage, in situ, of 30S ribosomal proteins to 16S rRNA.

The effects of ultraviolet radiation on the 30S ribosomal subunit of Escherichia coli were studied. Irradiation in aqueous solution under anaerobic conditions resulted in a dose-dependent decrease in the separability of the rRNA and protein components of the 30S ribosomal subunit in 4 M urea-3 M LiC1. The results of gel filtration studies of the irradiated ribosomes before and after treatment with pancreatic ribonuclease indicated that the decrease in separability of the ribosome components was a result of the photoinduced formation of covalent RNA-protein cross-links.

Photoinduced convalent crosslinkage, in situ, of Escherichia coli 50 S ribosomal proteins to rRNA.

Irradiation of aqueous solutions of Escherichia coli 50 S ribosomal subunits with 253.7 nm light results in the covalent crosslinkage of the rRNA and protein components. Neither peptide bond cleavage nor protein-protein crosslinkage accompanies the crosslinkage reactionmin addition, substantial photoinduced modifications in the primary structure of the ribosomal proteins, other than crosslinkage to rRNA, are not detected.

An Escherichia coli mutant with increased messenger ribonuclease activity.

A temperature-sensitive mutant strain of Escherichia coli exhibits a remarkable increase in RNase activity when grown at its nonpermissive temperature. During growth at the nonpermissive temperature, there is an increase in the extent of breakdown of pulse-labeled RNA and a decrease in the functional lifetime of the mRNA for the lac operon. T7 RNA, which is usually stable in E.