A Contingency Plan for Catastrophic Loss of Bioassay Services.

The catastrophic loss of direct or indirect bioassay services can severely impact a site or facility's radiation protection program. While highly unlikely, circumstances such as fire, hurricane, other extreme weather conditions, unanticipated events, or contractual business decisions could result in the loss of either the onsite or offsite measurement capabilities for direct or indirect radiobioassay services. The process and elements that need to be addressed in obtaining alternate or replacement bioassay services can be described in relatively simple terms, but can be very complex and time consuming to implement. The contingency plan developed for one large, complex radiobioassay program is a good example for addressing these items.

EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of americium in a USTUR leg phantom.

A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here.

Nutrient sensor O-GlcNAc transferase regulates breast cancer tumorigenesis through targeting of the oncogenic transcription factor FoxM1.

Cancer cells upregulate glycolysis, increasing glucose uptake to meet energy needs. A small fraction of a cell's glucose enters the hexosamine biosynthetic pathway (HBP), which regulates levels of O-linked beta-N-acetylglucosamine (O-GlcNAc), a carbohydrate posttranslational modification of diverse nuclear and cytosolic proteins. We discovered that breast cancer cells upregulate the HBP, including increased O-GlcNAcation and elevated expression of O-GlcNAc transferase (OGT), which is the enzyme catalyzing the addition of O-GlcNAc to proteins. Reduction of O-GlcNAcation through RNA interference of OGT in breast cancer cells leads to inhibition of tumor growth both in vitro and in vivo and is associated with decreased cell-cycle progression and increased expression of the cell-cycle inhibitor p27(Kip1). Elevation of p27(Kip1) was associated with decreased expression and activity of the oncogenic transcription factor FoxM1, a known regulator of p27(Kip1) stability through transcriptional control of Skp2. Reducing O-GlcNAc levels in breast cancer cells decreased levels of FoxM1 protein and caused a decrease in multiple FoxM1-specific targets, including Skp2. Moreover, reducing O-GlcNAcation decreased cancer cell invasion and was associated with the downregulation of matrix metalloproteinase-2, a known FoxM1 target. Finally, pharmacological inhibition of OGT in breast cancer cells had similar anti-growth and anti-invasion effects. These findings identify O-GlcNAc as a novel mechanism through which alterations in glucose metabolism regulate cancer growth and invasion and suggest that OGT may represent novel therapeutic targets for breast cancer.

Estimating 241Am activity in the body: comparison of direct measurements and radiochemical analyses.

The assessment of dose and ultimately the health risk from intakes of radioactive materials begins with estimating the amount actually taken into the body. An accurate estimate provides the basis to best assess the distribution in the body, the resulting dose and ultimately the health risk. This study continues the time-honoured practice of evaluating the accuracy of results obtained using in vivo measurement methods and techniques. Results from the radiochemical analyses of the (241)Am activity content of tissues and organs from four donors to the United States Transuranium and Uranium Registries (USTUR) were compared with the results from direct measurements of radioactive material in the body performed in vivo and post-mortem. Two were whole-body donations and two were partial-body donations. The (241)Am lung activity estimates ranged from 1 to 30 Bq in the four cases. The (241)Am activity in the lungs determined from the direct measurements were within 40% of the radiochemistry results in three cases and within a factor of 2 for the other case. However, in one case the post-mortem direct measurement estimate was a factor of 10 higher than the radiochemistry result for lung activity, most probably due to underestimating the skeletal contribution to the measured count rate over the lungs. The direct measurement estimates of liver activity ranged from 2 to 60 Bq and were consistently lower than the radiochemistry results. The skeleton was the organ with the highest deposition of (241)Am activity in all four cases. The skeletal activity estimates ranged from 30 to 300 Bq. The skeletal activity obtained from measurements over the forehead were within 20% of the radiochemistry results in three cases and differed by 78% in the other case. The results from this study suggest that the measurement methods, data analysis methods and calibration techniques used at the In Vivo Radiobioassay and Research Facility can be used to quantify the activity in the lungs, skeleton and liver when (241)Am activity is present in all three organs. The adjustment method used to account for the contribution from activity in other organs improved the agreement between the direct measurement results and the radiochemistry results for activity in the lungs and skeleton. The method appeared to overestimate the contribution from the other organs to the liver activity measurements, although the low activity levels complicated the analysis. The unadjusted liver activity estimates from the direct measurements were generally in better agreement with the radiochemistry results than the adjusted liver activity. The data from this study indicates that the results from the in vivo measurement techniques provide reasonable estimates of radioactive material in the lungs and skeleton under the most challenging conditions where there is (241)Am activity in multiple organs. The data analysis from additional USTUR cases with both direct measurement results and radiochemistry results is in progress to further evaluate how best to account for the contributions from (241)Am activity in multiple organs and to better understand the uncertainty associated with the adjusted activity.

USTUR whole body case 0262: 33-y follow-up of PuO2 in a skin wound and associated axillary node.

This whole body donation case (USTUR Registrant) involved two suspected PuO2 inhalation intakes, each indicated by a measurable Pu alpha activity in a single urine sample, followed about 1(1/2) y later by a puncture wound to the thumb while working in a Pu glovebox. The study is concerned with modelling simultaneously the biokinetics of deposition and retention in the respiratory tract and at the wound site; and the biokinetics of Pu subsequently transferred to other body organs, until the donor's death. Urine samples taken after the wound incident had readily measurable Pu alpha activity over the next 14 y, before dropping below the minimum detectable excretion rate (<0.4 mBq d(-1)). The Registrant died about 33 y after the wound intake, at the age of 71, from hepatocellular carcinoma with extensive metastases. At autopsy, all major soft tissue organs were harvested for analysis of their 238Pu, 239+240Pu and 241Am content. The amount of 239+240Pu retained at the wound site was 68 +/- 7 Bq (1 SD), measured by low-energy planar Ge spectrometry. A further 56.0 +/- 1.2 Bq was retained in an associated axillary lymph node, measured by radiochemistry. Simultaneous mathematical analysis (modelling) of all in vivo urinary excretion data, together with the measured lung, thoracic lymph node, wound, axillary lymph node and systemic tissue contents at death, yielded estimated intake amounts of 757 and 1504 Bq, respectively, for the first and second inhalation incidents, and 204 Bq for the total wound intake. The inhaled Pu material was highly insoluble, with an estimated long-term absorption rate from the lungs of 2 x 10(-5) d(-1). The Pu material deposited at the wound site was mixed: approximately 14% was rapidly absorbed, approximately 49% was absorbed at the rate of about 6 x 10(-5) d(-1), and the remainder ( approximately 37%) was absorbed extremely slowly (at the rate of about 5 x 10(-6) d(-1)). Thus, it was estimated that only approximately 40% of the Pu initially deposited in the wound had been absorbed systemically over the 33-y period until the donor's death. The biokinetic modelling also indicated that, in this individual case, some of the parameter values (rate constants) incorporated in the ICRP Publication 67 Pu model were up to a factor of 2 different from ICRP's recommended values (for reference man).

Estimated potassium content in Hanford workers.

Potassium content in male and female workers at the US Department of Energy Hanford Site was estimated based on measurements made in 2002 of 40K activity in the body. The 40K activity in females ranged from 2.1 to 4.1 kBq with an average of 3.1 +/- 0.02 kBq. The total body potassium (TBK) content in females averaged 98 +/- 0.6 g. The 40K activity in males ranged from 2.8 to 6.6 kBq with an average of 4.2 +/- 0.01 kBq and the average TBK was 136 +/- 0.3 g. The average TBK value for males aged 20-49 y was 140 g. The average TBK values for both genders decreased with age. The average potassium concentrations calculated for the different age ranges for males were 15-25% less than the value (1.9 gK per kg) obtained using the reported ICRP reference potassium and reference weight values. Potassium concentrations were inversely correlated with body-build index, body-mass index and body weight. These correlations could possibly be utilised to help assess the risk for disease. Future work is planned to evaluate whether monitoring of potassium concentrations could be used as a tool for the detection of diabetes and hypertension.

External gamma-ray counting of selected tissues from a Thorotrast patient.

Results of gamma-ray measurements of selected tissues from a patient who was injected with Thorotrast almost 36 y ago are reported. The purposes of this study were: 1) to determine the relative tissue distribution and activities of specific radionuclides in the 232Th decay chain, specifically 228Ra (as measured by 228Ac), 212Pb, and 224Ra (measured directly and as measured by 212Pb), and 2) to evaluate the level of radioactive disequilibrium among the daughter products. The spleen and liver had the highest concentrations of radioactivity. Bone also appears to be a long-term sink for 232Th daughter products based on estimates from a small portion of one rib. Larynx and esophagus contained measurable activity, which may have been due to their proximity to the "Thorotrastoma." Radioactivity in the remaining measured tissues were low, as expected. Secular equilibrium could be demonstrated in bone, pancreas, larynx, esophagus, and breast. Significant disequilibrium was observed for spleen, liver, kidney, and red blood cells. Radioactivity measurements reported here will be useful in estimating radiation doses to selected tissues. Such dose estimates are valuable in refining current risk estimates (e.g., liver) and in identifying tissues at risk for further epidemiologic studies. These results, while consistent with other published studies, should be interpreted with caution since measurements were made on only one patient.

Chronic wrist pain: spin-echo and short tau inversion recovery MR imaging and conventional and MR arthrography.

The accuracy of T1-, proton-density-, and T2-weighted magnetic resonance (MR) imaging sequences and gadolinium-enhanced MR arthrography in evaluation of the triangular fibro-cartilage complex (TFCC) and the scapholunate (SL) and lunotriquetral (LT) ligaments was studied in 15 patients with chronic wrist pain. Arthrography and arthroscopy were used as standards of reference. Twelve patients also underwent imaging with short tau inversion recovery (STIR) sequences. MR imaging was more reliable in evaluation of the morphology of the TFCC and SL ligament than in that of the LT ligament. With arthrography as the standard, sensitivity was 0.721, specificity was 0.947, and accuracy was 0.887 for the TFCC; these values were 0.500, 0.864, and 0.765 for the SL ligament and 0.519, 0.455, and 0.490 for the LT ligament. No visualization of the SL ligament indicated a tear, but this sign was not helpful in evaluation of the LT ligament. Fluid in the distal radioulnar joint had a high association with TFCC tears. Accuracy with MR arthrography was higher than with the other sequences. STIR images were effective in evaluation of the TFCC. The combination of proton-density-and T2-weighted images appears to be useful because morphologic characteristics and the presence of fluid can be evaluated.

Performance of an array of large-volume germanium detectors for whole-body counting.

An array of four large-volume coaxial germanium detectors was installed in a shielded room for the in vivo measurement of gamma emitters in the body. All four detectors are in a single 50-L dewar of liquid nitrogen and are positioned underneath the supine subject with the axes of the detector elements parallel with the length of the body. This orientation gives approximately 15% more counting efficiency than having the axes of the detectors perpendicular to the body length. The detectors have resolutions that are less than 2 keV with an average of 1.86 keV for the 60Co 1.33-MeV gamma-ray peak. The efficiencies of the four detectors range from 59% to 77% of a 7.62- x 7.62-cm (3- x 3-in.) NaI (Tl) detector. The detectors are interfaced to a multichannel analyzer such that spectra from the detectors are stored both as a sum of all counts from the four detectors and as a spectrum from each detector. The sensitivity of the germanium array for measuring radioactivity in the body exceeds that of multiple large NaI (Tl) detectors for measuring single radionuclides in the body and is much superior for measuring internal depositions of radionuclide mixtures. Another major advantage of this system compared to NaI(Tl) systems is that the results can be calculated by computer analysis with minimal human interpretation. The sensitivity of the array configuration is described and applications of the array in other configurations, such as that used for measuring the very small quantities of 24Na induced in the body during air travel, are also discussed.

Comparative skeletal distribution of Am and Pu in man, monkey, and baboon.

The skeletal distribution of Am and Pu in four human cases was compared with the skeletal distributions of these radioelements in baboons and monkeys. Excellent agreement was noted among the four human cases; data were available for Am in all four and Pu in three. A statistically significant correlation was found between the 241Am and 239Pu + 240Pu skeletal distributions in the humans and those in nonhuman primates. Trabecular bone had the highest concentrations of 241Am and 239+240Pu in humans, baboons, and monkeys. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton.

Treatment of mouse neoplasms with high doses of tubercidin.

Previous studies from this laboratory demonstrated that a potent inhibitor of nucleoside transport, nitrobenzylthioinosine (NBMPR), protected cultured cells against cytotoxic nucleosides (nebularine, tubercidin, and toyocamycin). NBMPR and its 5'-monophosphate (NBMPR-P) also protected mice against potentially lethal dosage of these agents. This report describes protection of mice from potentially lethal dosages of tubercidin by administration of NBMPR-P and the use of combinations of these agents in treatments of mice bearing transplanted neoplasms. Treatment of mice bearing i.p. implants of the Ehrlich ascites carcinoma, leukemia L1210/TG8, and colon carcinoma 26 with potentially lethal dosages of tubercidin administered together with host-protecting dosages of NBMPR-P resulted in substantial kill of neoplastic cells and long-term survivors. In these experiments, therapeutic effects were achieved at optimal dosages of NBMPR-P, which protected host vital tissues but did not protect neoplastic cells in ascitic fluids (Ehrlich ascites carcinoma cells and leukemia L1210/TG8 cells). However, at supraoptimal dosages of NBMPR-P, the occurrence of therapeutic failures which were neoplastic deaths indicated that NBMPR-P also protected the neoplastic ascites cells against tubercidin cytotoxicity. Thus, the selectivity of tubercidin toxicity toward cells of the Ehrlich ascites carcinoma and leukemia L1210/TG8 was modified by NBMPR-P dosage.

Therapy of mouse leukemia L1210 with combinations of nebularine and nitrobenzylthioinosine 5'-monophosphate.

Earlier reports from this laboratory showed that: (a) in the presence of nitrobenzylthioinosine (NBMPR), a potent, tightly bound inhibitor of nucleoside transport, cells proliferating in culture were protected against a number of cytotoxic nucleosides; and (b) mice were protected against potentially lethal dosages of nebularine (and other toxic nucleosides) by coadministration of NBMPR. The present study, which used nitrobenzylthioinosine 5'-phosphate (NBMPR-P), a readily soluble "prodrug" form of NBMPR, extended the in vivo protection studies and showed that the half-life of the protection effect was about 4 hr. In chemotherapy experiments, mice bearing transplanted neoplasms were treated with high dosages of nebularine together with protecting doses of NBMPR-P. When mice bearing leukemia L1010 were treated with a potentially lethal regimen of nebularine administered together with NBMPR-P, a substantial kill of leukemic cells resulted (some mice were long-term survivors). The therapeutic effect was optimal at dosage levels of the protecting agent in excess of those required in nonleukemic mice for protection against the lethal nebularine dosages used, suggesting that the therapeutic effect was due to the joint presence in the leukemic cells of a metabolite of NBMPR-P and nebularine; NBMPR-P protection of the leukemic host against nebularine lethality was necessary for the therapeutic effect to be manifested.

Protection of mice against lethal dosages of nebularine by nitrobenzylthioinosine, an inhibitor of nucleoside transport.

In the presence of nitrobenzylthioinosine (NBMPR) a potent inhibitor of nucleoside transport, Roswell Park Memorial Institute 6410 cells proliferating in culture were protected from otherwise inhibitory concentrations of 9-beta-D-ribofuranosylpurine (nebularine); cellular uptake of nebularine was greatly reduced under these circumstances. Initial rates of nebularine uptake by Roswell Park Memorial Institute 6410 cells were inhibited by NBMPR, indicating that the latter interfered with nebularine transport. NBMPR protected mice against potentially lethal treatment regimens with nebularine, 4-amino-7-(beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine (tubercidin) or 4-amino-5-cyano-7-(beta-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine (toyocamycin); protection resulted when NBMPR was administered i.p. in advance of or simultaneously with nebularine, but not when NBMPR followed nebularine by 1 hr. Both NBMPR and its 5'-monophosphate protected mice against nebularine lethality when administered s.c.

Fluctuations in nucleoside uptake and binding of the inhibitor of nucleoside transport, nitrobenzylthioinosine, during the replication cycle of HeLa cells.

Binding of the potent nucleoside transport inhibitor 6-[(4-nitrobenzyl)thio]-9-beta-D-ribofuranosylpurine (NBMPR) and rates of uptake of several nucleosides were examined at 4-hr intervals during the replication cycle of HeLa S3 cells. Monolayer cultures of synchronous cells, obtained by mitotic detachment, were assayed for high-affinity binding of NBMPR and for rates of uptake of thymidine, uridine, cytidine, adenosine, inosine, and guanosine. The number of NBMPR binding sites per cell doubled between 4 and 16 hr after detachment (late G1 and S phase); during this interval, V max 'S for uptake of cytidine and adenosine doubled, and for uridine and thymidine uptake increased about 4- and 8-fold, respectively. Rates of inosine and guanosine uptake at extracellular concentrations below saturation increased 2-fold between G1 and S phase of the cell cycle. Km 'S for cellular uptake of thymidine, uridine, cytidine, and adenosine did not change with progress through the cycle. The results presented suggest that changes in nucleoside uptake during the HeLa cell cycle were due, in part, to changes in the activity of NBMPR-sensitive transport elements in the membrane.

Flow-directed balloon catheterization for aortofemoral arteriography using the axillary artery approach.

An axillary artery approach is occasionally necessary in the evaluation of the abdominal aorta and peripheral arteries in patients with severe and complicated arteriosclerotic disease. Difficulty may be encountered in directing the catheter into the descending aorta in patients with extremely tortuous and elongated aortic arches. Use of flow directed angiographic balloon catheters has made abdominal, pelvic, and lower extremity arteriography readily obtainable using an axillary approach when other methods failed and translumbar aortography was considered hazardous. This might be particularly useful in patients with high abdominal aortic occlusions, in anticoagulated patients, in patients with abdominal aortic grafts, and in some patients with small aortas displaced to the right.

Arthrography in the evaluation of the temporomandibular joint.

Temporomandibular joint arthrography has been helpful in selecting patients for reconstructive surgery who have severe temporomandibular joint dysfunction. Structural abnormalities of the soft tissues can be demonstrated where only minimal osseous changes are seen on tomography. The normal arthrographic anatomy of the joint is reviewed and normal and pathological joints are illustrated.

Defective transport of thymidine by cultured cells resistant to 5-bromodeoxyuridine.

A line of HeLa cells resistant to 5-bromo-2'-deoxyuridine (BUdR) was established by continuous culture in growth medium containing BUdR; during the selection period, BUdR concentrations, initially 15 micrometer, were gradually increased to 100 micrometer. Cells of a clone (HeLa/B5) established from this line were also resistant to 5-fluoro-2'-deoxyuridine (FUdR), but not to the free base, 5-fluorouracil. Although extracts of HeLa/B5 cells exhibited levels of thymidine kinase activity comparable to those of parental cells, rates of uptake of BUdR, FUdR, and thymidine into intact cells were much reduced. The kinetics of uptake of uridine and adenosine, nucleosides which appear to be transported independently of thymidine in HeLa cells, were similar for HeLa/B5 and the parental line (HeLa/O). Relative to thymidine uptake by HeLa/O cells, that by HeLa/B5 cells was distinctly less sensitive to nitrobenzylthioinosine (NBMPR), a specific inhibitor of nucleoside transport in various types of animal cells. Despite this difference in NBMPR sensitivity, both cell lines possessed the same number of high affinity NBMPR binding sites per mg cell protein. The altered kinetics of thymidine uptake and the NBMPR insensitivity of that function in HeLA/B5 cells suggest that resistance to BUdR is due to an altered thymidine transport mechanism.