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Prospects for the Precision Measurement of {alpha}{sub s}

Description: The prospects for the measurement of the strong coupling constant {alpha}{sub MS}(M{sub Z}) to a relative uncertainty of 1 % are discussed. Particular emphasis is placed on the implications relating to future High Energy Physics facilities.
Date: December 1996
Creator: Burrows, P. N.; Dixon, L. & El-Khadra, A. X.
Partner: UNT Libraries Government Documents Department

Relevance of in vivo models in melanoma skin cancer

Description: A discussion of possible wavelength dependence of induction of cutaneous malignant melanoma (CMM) is provided. Strengths and weaknesses of various experimental approaches to better understanding of the prevalence of CMM in different human populations including latitude effects are compared. Further the advantages and limitations of the use of the laboratory opossum (Monodelphis domestic), transgenic mice containing SV40 ongogene sequences under tyrosinase promoter control, and a backcross hybrid fish of the genus Xenophorus are contrasted.
Date: December 31, 1995
Creator: Setlow, R.B.
Partner: UNT Libraries Government Documents Department

Interim report on intrathoracic radiotherapy of human small-cell lung carcinoma in nude mice with Re-188-RC-160, a radiolabeled somatostatin analogue

Description: The purpose of this study was to evaluate the therapeutic efficacy of Re-188-RC-160 in experimental models of human small cell lung carcinomas which mimic the clinical presentation. In the experimental model, cells from the human small cell lung carcinoma cell line NCI-H69 cells were inoculated into the thoracic cavity of athymic mice and rats. Subsequently, the biodistribution of Re-188-RC-160 after injection into the pleural cavity, a radiolabeled somatostatin analogue, was monitored as was the effect on the subsequent growth of tumors. The results presented here, and which are a part of a larger series of studies, suggest that Re-188-RC-160 can be effectively used in this animal model to restrict the growth of small cell lung carcinoma in the thoracic cavity.
Date: July 1, 1995
Creator: Zamora, P.O.; Bender, H.; Biersack, H.J. & Knapp, F.F. Jr.
Partner: UNT Libraries Government Documents Department

Spatially fractionated microirradiation of normal CNS and gliosarcomas of the rat with synchrotron photons: Cell and tissue lesions; Raeumlich fraktionierte Mikrobestrahlung von normalem ZNS und Gliosarkomen der Ratte mit Synchrotron-Photonen: Zell- und Gewebelaesionen

Description: Rats were implanted intracerebrally with 9L gliosarcoma cells were used to experimentally determine the curative effectiveness of synchrotron radiation produced by the National Synchrotron Radiation Source. Radiation was delivered in beams with each ray 25 micrometers thick and arranged in an array of 4 mm corners. All experimental animals receiving the gliosarcoma cells and not treated died within four weeks. Treated animals surviving 113 days were sacrificed and their brains were examined histologically.
Date: December 31, 1995
Creator: Laissue, J.A.; Spanne, P.; Dilmanian, F.A.; Nawrocky, M.N.; Slatkin, D.N.; Joel, D.D. et al.
Partner: UNT Libraries Government Documents Department

BPA uptake in rat tissues after partial hepatectomy

Description: In boron neutron capture therapy (BNCT), boron given as boronophenylalanine (BPA) accumulates transiently not only in tumors but also in normal tissues. Average boron concentrations in transplanted 9L gliosarcoma tumors of 20 rats were 2.5 to 3.7 times concentrations found in blood. Although boron levels in a variety of tissues were also higher than blood the concentrations were less than the lowest found in the tumor. Further note than although BPA is a structural analogue of phenylalanine (Phe), the pathway of BPA uptake into regenerating liver may not be linked to Phe uptake mechanisms.
Date: December 31, 1996
Creator: Slatkin, D.N.; Nawrocky, M.M.; Coderre, J.A.; Fisher, C.D.; Joel, D.D.; Lombardo, D.T. et al.
Partner: UNT Libraries Government Documents Department

Radiogenic neoplasia in thyroid and mammary clonogens. Final progress report, 1 January 1987--31 December 1997

Description: The induction of cancer by ionizing radiation is a matter of great practical importance to the nuclear industry, to national defense, to radiological medicine and to the general public. It is increasingly apparent that carcinogenesis is a leading dose-limiting effect of radiation exposure. The thyroid and mammary glands are among the most sensitive human tissues to radiogenic initiation of cancer, and there is a profoundly higher risk of neoplastic initiation in these glands among individuals irradiated before or during puberty than among those exposed in later life. The authors developed unique quantitative experimental models to investigate and characterize the cells of origin of thyroid and mammary cancers and the effects of radiation on them (C185). To study these progenitor cells in vivo it is necessary to have a system by which their concentrations, total numbers and responses to radiation and other factors can be measured. It is a truism that not all cells in a tissue are equally sensitive to neoplastic initiation. They reasoned that the progenitor cells are most likely members of that subpopulation that is necessary to maintenance of normal tissue cell numbers and to repair and replacement after tissue damage. They further reasoned that such cells would likely be responsive to specific mitogenic stimulation by hormones. On the basis of these considerations, they developed quantitative rat thyroid and mammary epithelial cell transplantation systems.
Date: July 10, 1998
Creator: Clifton, K.H.
Partner: UNT Libraries Government Documents Department

Epidermal growth factor (EGF) as a potential targeting agent for delivery of boron to malignant gliomas

Description: The majority of high grade gliomas express an amplified epidermal growth factor receptor (EGFR) gene, and this often is associated with an increase in cell surface receptor expression. The rapid internalization and degradation of EGF-EGFR complexes, as well as their high affinity make EGF a potential targeting agent for delivery of {sup 10}B to tumor cells with an amplified number of EGFR. Human glioma cells can expresses as many as 10{sup 5} {minus}10{sup 6} EGF receptors per cell, and if these could be saturated with boronated EGF, then > 10{sup 8} boron atoms would be delivered per cell. Since EGF has a comparatively low molecular weight ({approximately} 6 kD), this has allowed us to construct relatively small bioconjugates containing {approximately} 900 boron atoms per EGF molecule{sup 3}, which also had high affinity for EGFR on tumor cells. In the present study, the feasibility of using EGF receptors as a potential target for therapy of gliomas was investigated by in vivo scintigraphic studies using {sup 131}I{minus} or {sup 99m}{Tc}-labeled EGF in a rat brain tumor model. Our results indicate that intratumorally delivered boron- EGF conjugates might be useful for targeting EGFR on glioma cells if the boron containing moiety of the conjugates persisted intracellularly. Further studies are required, however, to determine if this approach can be used for BNCT of the rat glioma.
Date: December 31, 1994
Creator: Capala, J.; Barth, R.F.; Adams, D.M.; Bailey, M.Q.; Soloway, A.H. & Carlsson, J.
Partner: UNT Libraries Government Documents Department

Effect of negative pions on the proliferative capacity of ascites tumor cells (lymphoma) grown in vivo

Description: We have attempted to determine the relative biological effectiveness (RBE) of negative pions in the Bragg-peak region as compared to the plateau region and to gamma rays. We irradiated LAF{sub 1} mice, bearing 5-day-old lymphoma ascites tumors, in the peak and plateau regions of a 90-MeV pion beam for 40 hours in temperature-controlled holders. The animals were then sacrificed; lymphoma cells were withdrawn and titrated into adult female LAF{sub 1} mice. The proliferative capacity of the irradiated tumor cells was evaluated after 8 weeks by observing the percentage of animals developing ascites tumors. Surviving fractions were then calculated from LD{sub 50}`s of control and irradiated animals. Radiation doses in the 50 plateau region were measured with LiF dosimeters calibrated against cobalt-60 gamma rays. We calculated peak doses from those at the plateau, using a measured average peak-to-plateau ionization ratio of 1.5. Doses in the plateau region ranged from 145 to 250 rads; doses in the peak region ranged from 220 to 380 rads. The survival curve for cells irradiated in the peak region gave a D{sub 0} of 65 {plus_minus} 15 rads. The plateau points were not reliable. A replicate experiment was performed using Co{sup 60} {gamma}-rays, yielding a survival-curve D{sub 0} of 350 {plus_minus} 50 rads. If the {gamma}-ray D{sub 0} is taken as a baseline, an RBE of 5.4 {plus_minus} 1.8 is obtained for negative pions in the peak region, based on the ratio of-peak-region D{sub 0} to Co{sup 60} D{sub 0}.
Date: March 30, 1967
Creator: Feola, J.M.; Richman, C.; Raju, M.R.; Curtis, S.B. & Lawrence, J.H.
Partner: UNT Libraries Government Documents Department

Protection by WR-151327 against late-effect damage from fission-spectrum neutrons

Description: Considerable effort has been expended to develop chemical agents capable of modifying radiation-induced damage to biological systems. The authors describe here differences in the radioprotective effect of WR-151327, depending on the sex of the animal and the post-irradiation time interval considered. The greatest effect in female animals is prior to 805 days post irradiation. The greater protection in male animals is seen during the time increment following 850 days after irradiation. While it is difficult at present to ascribe these effects to a particulate model, it is suggestive that hormonal factors may play a role in aminothiol protection against radiation-induced life shortening and concomitant tumor induction in the B6CF{sub 1} hybrid mouse system. With respect to subsequent tumor induction, their preliminary findings to be published elsewhere suggest that tumors of lymphoreticular origin are the class of tumors most affected by the administration of a radioprotector prior to irradiation. 23 refs., 4 figs.
Date: January 1, 1990
Creator: Grdina, D.J. (Argonne National Lab., IL (USA) Chicago Univ., IL (USA). Dept. of Radiation and Cellular Oncology); Wright, B.J. & Carnes, B.A. (Argonne National Lab., IL (USA))
Partner: UNT Libraries Government Documents Department

(Accumulation of methyl-deficient rat liver messenger ribonucleic acid on ethionine administration). Progress report. [Methyltransferase activity in Ehrlich ascites tumor cells and effects of phorbol ester on methyltransferase activity]

Description: Enzyme fractions were isolated from Ehrlich ascites cells which introduced methyl groups into methyl deficient rat liver mRNA and unmethylated vaccinia mRNA. The methyl groups were incorporated at the 5' end into cap 1 structures by the viral enzyme, whereas both cap 0 and cap 1 structures were formed by the Ehrlich ascites cell enzymes. Preliminary results indicate the presence of adenine N/sup 6/-methyltransferase activity in Ehrlich ascites cells. These results indicate that mRNA deficient in 5'-cap methylation and in internal methylation of adenine accumulated in rats on exposure to ethionine. The methyl-deficient mRNA isolated from the liver of ethionine-fed rats differed in its translational properties from mRNA isolated from control animals. Preliminary experiments indicate that single topical application of 17n moles of TPA to mouse skin altered tRNA methyltransferases. The extent of methylation was increased over 2-fold in mouse skin treated with TPA for 48 hours. These changes have been observed as early as 12 hours following TPA treatment. In contrast, the application of initiating dose of DMBA had no effect on these enzymes. It should be emphasized that the changes in tRNA methyltransferases produced by TPA are not merely an increase of the concentration of the enzyme, rather that they represent alterations of specificity of a battery of enzymes. In turn the change in enzyme specificity can produce alterations in the structure of tRNA. (ERB)
Date: January 1, 1980
Creator: Borek, E.
Partner: UNT Libraries Government Documents Department

Characterization of cell suspensions from solid tumors

Description: The desirable features of cells in suspension will necessarily be dependent upon the use for which the cells were prepared. Adequate cell yield or recovery is defined by the measurement to be performed. Retention of cellular morphology is important for microscopic identification of cell types in a heterogenous cell suspension, and may be used to determine whether the cells in suspension are representative of those in the tumor in situ. Different dispersal protocols may yield cells with different degrees of clonogenicity, as well as altered biochemical features, such as loss of cellular proteins, surface antigens, nucleotide pools, etc. The quality of the cell suspension can be judged by the degree of cell clumping and level of cellular debris, both of which impact on flow cytometric measurements and studies in which the number of cells be known accurately. Finally, if the data measured on the cells in suspension are to be extrapolated to phenomena occurring in the tumor in situ, it is desirable that the cells in suspension are representative of those in the solid tumor in vivo. This report compares characteristics of tumor cell suspensions obtained by different types of selected disaggregation methods. 33 refs., 2 figs., 4 tabs.
Date: July 10, 1985
Creator: Pallavicini, M.
Partner: UNT Libraries Government Documents Department

(New imaging systems in nuclear medicine)

Description: Further progress has been made on improving the uniformity and stability of PCR-I, the single ring analog coded tomograph. This camera has been employed in a wide range of animal studies described below. Data from PCR-I have been used in various image processing procedures. These include motion pictures of dog heart, comparison of PET and MRI image in dog heart and rat brain and quantitation of tumor metabolism in the nude mouse using blood data from heart images. A SUN workstation with TAAC board has been used to produce gated three-dimensional images of the dog heart. The ANALYZE program from the Mayo Clinic has also been mounted on a SUN workstation for comparison of images and image processing. 15 refs., 6 figs.
Date: January 1, 1990
Partner: UNT Libraries Government Documents Department

Cell proliferation kinetics and radiation response in 9L tumor spheroids

Description: Cell kinetic parameters, including population doubling-time, cell cycle time, and growth fraction, were measured in 9L gliosarcoma spheroids. These parameters were studied as the spheroids grew from 50 ..mu..m to over 900 ..mu..m in diameter. Experiments relating the cell kinetic parameters to the radiation response of 9L spheroids were also carried out. The major findings were that the average cell cycle time (T/sub c/), is considerably longer in large spheroids than in exponentially-growing monolayers, the radiosensitivity of noncycling (but still viable) cells in spheroids is not significantly different from that of cycling spheroid cells, and the radiation-induced division delay is approximately twice as long in spheroid cells as in monolayer cells given equal radiation doses. The cell loss factor for spheroids of various sizes was calculated, by using the measured kinetic parameters in the basic equations for growth of a cell population. 157 references, 6 figures, 3 tables.
Date: May 1, 1984
Creator: Sweigert, S.E.
Partner: UNT Libraries Government Documents Department

Radiolabeled porphyrin versus gallium-67 citrate for the detection of human melanoma in athymic mice

Description: We performed the biodistribution and imaging studies of /sup 111/In and /sup 67/Ga labeled tetra(4-N-methylpyridyl) porphine, (T4NMPYP), and compared it to that of /sup 67/Ga citrate in athymic mice bearing a human melanoma xenograft. The biodistribution results of both /sup 111/In and /sup 67/Ga labeled T4NMPYP (3, 6, 24, and 48 hours) were similar but differed from that of /sup 67/Ga citrate (48 hours). The optimum tumor uptake of both radiolabeled porphyrins was at 6 hours postinjection and was lower than the tumor uptake of /sup 67/Ga citrate at 48 hours postinjection. Kidney was the only organ showing higher uptake of radiolabeled porphyrin compared to that of /sup 67/Ga citrate. The imaging studies performed with /sup 111/In T4NMPYP and /sup 67/Ga citrate correspond to the biodistribution results. Osteomyelitis present in one mouse showed good localization of /sup 111/In T4NMPYP. 15 refs., 3 figs., 5 tabs.
Date: January 1, 1987
Creator: Maric, N.; Chan, S. Ming; Hoffer, P.B. & Duray, P.
Partner: UNT Libraries Government Documents Department

Biological efficacy of a boronated porphyrin as measured in cell culture

Description: Attempts to develop a boronated porphyrin analog have suffered from problems associated with toxicity, solubility and, upon occasion, lability of the boron tag. One compound synthesized by one of us (SBK), designated ''SBK-II'', has evidently overcome the above problems, providing therapeutic amounts of boron in animal tumor models (20-40 ..mu..g B/g tumor) with retention times in the order of weeks. As is well known, biological efficacy will depend upon distribution within (or without) the cell. In the experiments detailed here, biological efficacy has been evaluated in Hamster V-79 cells, irradiated at the thermal neutron beam at the Brookhaven Medical Research Reactor, using irradiation geometries and techniques as described in detail elsewhere. Cell survival curves obtained with 15 and 29 ..mu..g /sup 10/B per ml from H/sub 3//sup 10/BO/sub 3/ (''ambient'' conditions) were compared to a control (no boron) curve (data not shown). 2 refs., 3 figs., 1 tab.
Date: January 1, 1987
Creator: Laster, B.H.; Kahl, S.B.; Kalef-Ezra, J.; Popenoe, E.A. & Fairchild, R.G.
Partner: UNT Libraries Government Documents Department

Distribution of sulfhydryl boranes in mice and rats

Description: The distribution of boron in mice bearing transplanted Harding-Passey melanomas after rapid and slow administration of monomer were studied. Thin layer chromatographic analysis of the corresponding infusion solution revealed a slow-moving principal band that was later shown to correspond to Na/sub 4/B/sub 24/H/sub 22/S/sub 2/, the dimer of Na/sub 2/B/sub 12/H/sub 11/SH. It was found that while monomer and chemically synthesized dimer yielded similar boron concentrations when they were given rapidly intraperitoneally to mice, the dimer yielded higher boron concentrations in mouse melanoma and higher melanoma-blood boron concentration when each was infused slowly intraperitoneally for 8 to 9 days. Studies have been started on the uptake of dimer into an intracerebrally implanted rat glioma. Boron levels in the rat glioma and in the mouse melanoma from slow intraperitoneal infusion of proportionately comparable amounts of dimer, are similar. However, after these slow infusions boron levels in rat blood are about as high as boron levels in rat brain tumor. 6 refs., 1 fig., 4 tabs.
Date: January 1, 1986
Creator: Slatkin, D.N.; Micca, P.L.; Laster, B.H. & Fairchild, R.G.
Partner: UNT Libraries Government Documents Department

Heterogeneity in cytokinetic, clonogenic, and radiation response induced by nutrient deprivation

Description: A murine fibrosarcoma cell line (FSA 1233), with a capability to grow in vitro, was used to study biophysical heterogeneity induced by nutrient deprivation. Cell sub-populations were isolated by centrifuging cells through linear Renografin-density gradients. The effects of cell growth to late plateau phase on the cytokinetic, clonogenic, and radiation-survival characteristics were studied. It was observed that with increasing age of the cell culture, an increase in the proportion of relatively dense cells was associated with a decrease in plating efficiency. Cells collected at p=1.08 g/cm{sup 3} have a plating efficiency of 0.2% compared with 0.01% for those isolated at p=1.16 g/cm{sup 3}. Discrepancies were also seen between the tritiated thymidine labeling index (LI) and flow cytometry (FCM, % S phase) for cells collected throughout the gradient. The radiation sensitivities of selected cell populations isolated by density gradient centrifugation were determined and compared with data from a control plateau phase population. 15 refs., 4 figs., 1 tab.
Date: January 1, 1986
Creator: Grdina, D.J. (Argonne National Lab., IL (USA)); Williamson, K.D.; Johnson, T.S. (Anderson (M.D.) Hospital and Tumor Inst., Houston, TX (USA)) & Sigdestad, C.P. (Louisville Univ., KY (USA). Dept. of Radiation Oncology)
Partner: UNT Libraries Government Documents Department

Synthesis and evaluation of boron compounds for neutron capture therapy of malignant brain tumors

Description: Boron neutron capture therapy offers the potentiality for treating brain tumors currently resistant to treatment. The success of this form of therapy is directly dependent upon the delivery of sufficient numbers of thermal-neutrons to tumor cells which possess high concentrations of B-10. The objective of this project is to develop chemical methodology to synthesize boron-containing compounds with the potential for becoming incorporated into rapidly-dividing malignant brain tumor cells and excluded from normal components of the brain and surrounding tissues, to develope biological methods for assessing the potential of the compound by use of cell culture or intratumoral injection, to develop analytical methodology for measuring boron in cells and tissue using direct current plasma atomic emission spectroscopy (DCP-AES) and alpha track autoradiography, to develop biochemical and HPLC procedures for evaluating compound uptake and tissue half-life, and to develop procedures required to assess both in vitro and vivo efficacy of BNCT with selected compounds.
Date: January 1, 1990
Creator: Soloway, A.H. & Barth, R.F.
Partner: UNT Libraries Government Documents Department

Experimental, statistical, and biological models of radon carcinogenesis

Description: Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig.
Date: September 1, 1991
Creator: Cross, F.T.
Partner: UNT Libraries Government Documents Department

In-vitro and in-vivo characterization of ruthenium-bleomycin compared to cobalt- and copper-bleomycin

Description: Bleomycin (BLM) has undergone extensive investigation both as a cancer chemotherapeutic agent, and as a carrier for radionuclides for tumor imaging. The available methods or the radionuclides used, however, have had limited effectiveness. Although labeling of BLM with /sup 103/Ru has been reported earlier, we carried out a study to develop a more reproducible method of labeling particularly for use with Brookhaven Linac Isotope Producer produced /sup 97/Ru. Ruthenium-97 has favorable physical properties that make it ideal for imaging applications: decay by electron capture; ..gamma.. 216 keV, 85%; t/sub 1/2/ 2.9 d. A novel method based on the reduction of Ru/sup 3 +/ to Ru/sup 2 +/ using stannous chloride was investigated for labeling BLM with /sup 97/Ru and/or /sup 103/Ru. In-vitro and in vivo comparisons of the product(s) with /sup 57/Co and /sup 67/Cu-labeled BLM were also carried out. 4 refs., 3 tabs.
Date: January 1, 1986
Creator: Shao, H.S.; Meinken, G.E.; Srivastava, S.C.; Slosman, D.; Sacker, D.F.; Som, P. et al.
Partner: UNT Libraries Government Documents Department

Boron neutron capture therapy of ocular melanoma and intracranial glioma using p-boronophenylalanine

Description: During conventional radiotherapy, the dose that can be delivered to the tumor is limited by the tolerance of the surrounding normal tissue within the treatment volume. Boron Neutron Capture Therapy (BNCT) represents a promising modality for selective tumor irradiation. The key to effective BNCT is selective localization of {sup 10}B in the tumor. We have shown that the synthetic amino acid p-boronophenylalanine (BPA) will selectively deliver boron to melanomas and other tumors such as gliosarcomas and mammary carcinomas. Systemically delivered BPA may have general utility as a boron delivery agent for BNCT. In this paper, BNCT with BPA is used in treatment of experimentally induced gliosarcoma in rats and nonpigmented melanoma in rabbits. The tissue distribution of boron is described, as is response to the BNCT. 6 refs., 4 figs., 1 tab.
Date: January 1, 1990
Creator: Coderre, J.A.; Greenberg, D.; Micca, P.L.; Joel, D.D.; Saraf, S. (Brookhaven National Lab., Upton, NY (USA)) & Packer, S. (North Shore Univ. Hospital, Manhasset, NY (USA). Div. of Ophthalmology)
Partner: UNT Libraries Government Documents Department

Neutron issues in the JANUS mouse program

Description: Over the last 25 years, the JANUS program in the Biological and Medical Research Division at Argonne National Laboratory (ANL) has compiled a database on the response of both sexes of an F{sub 1} hybrid mouse, the B6CF{sub 1} (C57BL/6 x BALB/c), to external whole- body irradiation by {sup 60}Co {gamma}-rays and fission neutrons. Three basic patterns of exposure for both neutrons and {gamma}-rays have been investigated: single exposures, 24 equal once-weekly exposures, and 60 equal once-weekly exposures. All irradiations were terminated at predetermined total doses, with dose calculated in centigrays at the midline of the mouse. Three endpoints will be discussed in this paper: (1) life shortening, (2) a point estimate for cumulative mortality, and (3) the hazard function. Life shortening is used as an analysis endpoint because it summarizes, in a single index, the integrated effect of all injuries accumulated by an organism. Histopathological analyses of the mice used in the ANL studies have indicated that 85% of the deaths were caused by neoplasms. Connective tissue tumors were the dominant tumor in the B6CF{sub 1} mouse, with tumors of lymphoreticular origin accounting for approximately 80% of this class. The latter two endpoints will therefore be used to describe the life table experience of mice dying from the lymphoreticular class of tumors. Dose-response models will be applied to the three endpoints in order to describe the response function for neutron exposures, evaluate the effect of dose range and pattern of exposure on the response function for neutrons, and provide a set of neutron relative biological effectiveness (RBE) values of the ANL database. 25 refs.
Date: January 1, 1990
Creator: Carnes, B.A. & Grahn, D.
Partner: UNT Libraries Government Documents Department

In vivo studies in NCT with a boronated porphyrin and tumor growth delay as an end point

Description: The robust carrying capacity of the porphyrin molecule and its propensity for localizing in tumor justified the synthesizing of a porphyrin labeled with boron for use in BNCT. However, problems associated with poor solubility impeded the utility of the molecule. Until BOPP was synthesized porphyrins were promising, but impractical. After in vitro experiments had demonstrated the biological efficacy of BOPP and had confirmed its intracellular localizing ability in vivo studies were carried out using mice. Irradiation of KHJJ murine mammary carcinoma to the TCD[sub 50] in a single fraction was precluded since this whole body dose is lethal. This problem was overcome by the use of radiation. BOPP was administered either as three 0.5 ml injections per day over two days or by continuous i.v. infusion, 2 ml per day over three days for a total dose of about 42 [mu]g [sup 10]B/gbw. Boron-10 distribution in the tumor at the time of irradiation was [approximately]20 [mu]g.
Date: January 1, 1992
Creator: Laster, B.H. (Brookhaven National Lab., Upton, NY (United States) State Univ. of New York, Stony Brook, NY (United States). Dept. of Radiation Oncology); Kahl, S.B. (California Univ., San Francisco, CA (United States). Dept. of Pharmaceutical Chemistry); Warkentien, L. & Bond, V.P. (Brookhaven National Lab., Upton, NY (United States))
Partner: UNT Libraries Government Documents Department

Research in radiobiology: Final report of work in progress in immunobiology of experimental host-tumor relationships

Description: Our work on the immunobiology of tumors induced in normal mice by non-ionizing radiation and chemical carcinogens has previously demonstrated a correlation between MHC molecule expression and the immunogenicity of tumors in a transplanted syngeneic host. Such that immunogenic or regressive tumors were found to demonstrate higher constitutive or inducible levels of MHC expression, while most virulent, aggressive tumors exhibited a low level of MHC Class I expression. We attributed much of the control of MHC molecule expression by antigen-bearing tumors and normal cells to the immunological status of the host since the host must provide the appropriate stimulus to enhance MHC antigen expression by the invading tumor. Our results with UVR-induced tumors suggested that a significant role is played by the T-cell lymphokine, [gamma]-interferon ([gamma]IFN), in the modulation of MHC molecule expression in vivo. Virulent tumors, induced by boneseeking radionuclides, may be refractory to [gamma]IFN stimulation of MHC molecule expression. It is also possible that certain tumors might be fully responsive to the Class I modulatory influences by [gamma]IFN, but exhibit a reduced capacity to stimulate the synthesis of this lymphokine by host T cells. We present experiments designed to : Describe the virulence, latency period, and transplantation characteristics of [sup 238]PU, [sup 24l]Am, and [sup 228]Th tumors arising as osteogenic sarcomas and hepatic carcinomas, to determine the relationship between inducible expression of MHC Class I molecules by [gamma]IFN and in vivo immunogenicity of these radioisotype-induced tumors, and to elucidate any molecular mechanisms responsible for a lack of responsiveness to a [gamma]IFN failure by the host to induce host [gamma]IFN production.
Date: March 15, 1993
Partner: UNT Libraries Government Documents Department