53 Matching Results

Search Results

Advanced search parameters have been applied.

Cell-Type-Specific Genome-wide Expression Profiling after Laser Capture Microdissection of Living Tissue

Description: The purpose of this technical feasibility study was to develop and evaluate robust microgenomic tools for investigations of genome-wide expression of very small numbers of cells isolated from whole tissue sections. Tissues contain large numbers of cell-types that play varied roles in organ function and responses to endogenous and exogenous toxicants whether bacterial, viral, chemical or radiation. Expression studies of whole tissue biopsy are severely limited because heterogeneous cell-types result in an averaging of molecular signals masking subtle but important changes in gene expression in any one cell type(s) or group of cells. Accurate gene expression analysis requires the study of specific cell types in their tissue environment but without contamination from surrounding cells. Laser capture microdissection (LCM) is a new technology to isolate morphologically distinct cells from tissue sections. Alternative methods are available for isolating single cells but not yet for their reliable genome-wide expression analyses. The tasks of this feasibility project were to: (1) Develop efficient protocols for laser capture microdissection of cells from tissues identified by antibody label, or morphological stain. (2) Develop reproducible gene-transcript analyses techniques for single cell-types and determine the numbers of cells needed for reliable genome-wide analyses. (3) Validate the technology for epithelial and endothelial cells isolated from the gastrointestinal tract of mice.
Date: February 9, 2005
Creator: Marchetti, F & Manohar, C F
Partner: UNT Libraries Government Documents Department

Detection of gastrointestinal cancer by elastic scattering and absorption spectroscopies with the Los Alamos Optical Biopsy System

Description: The Los Alamos National Laboratory has continued the development of the Optical Biopsy System (OBS) for noninvasive, real-time in situ diagnosis of tissue pathologies. In proceedings of earlier SPIE conferences we reported on clinical measurements in the bladder, and we report here on recent results of clinical tests in the gastrointestinal tract. With the OBS, tissue pathologies are detected/diagnosed using spectral measurements of the elastic optical transport properties (scattering and absorption) of the tissue over a wide range of wavelengths. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, exhibit significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes m an optical signature that is derived from the wavelength-dependence of elastic scattering. Additionally, the optical geometry of the OBS beneficially enhances its sensitivity for measuring absorption bands. The OBS employs a small fiber-optic probe that is amenable to use with any endoscope or catheter, or to direct surface examination, as well as interstitial needle insertion. Data acquistion/display time is <1 second.
Date: March 1, 1995
Creator: Mourant, J.R.; Boyer, J.; Johnson, T.M.; Lacey, J.; Bigio, I.J.; Bohorfoush, A. et al.
Partner: UNT Libraries Government Documents Department

A Revised Model for Dosimetry in the Human Small Intestine

Description: A new model for an adult human gastrointestinal tract (GIT) has been developed for use in internal dose estimations to the wall of the GIT and to the other organs and tissues of the body from radionuclides deposited in the lumenal contents of the five sections of the GIT. These sections were the esophasgus, stomach, small intestine, upper large intestine, and the lower large intestine. The wall of each section was separated from its lumenal contents.
Date: February 28, 2005
Creator: Poston, John; Bhuiyan, Nasir U.; Redd, R. Alex; Parham, Neil & Watson, Jennifer
Partner: UNT Libraries Government Documents Department

Monte Carlo investigations of elastic scattering spectroscopy applied to latex spheres used as tissue phantoms

Description: An optical-fiber-coupled, elastic-scatter spectrometer has proven effective in discriminating between malignant and non-malignant tissue in the human bladder and gastrointestinal tract. The system injects broadband light into the tissue with an optical fiber and spectrally analyzes the returning light collected by an adjacent fiber. The collected photons have experienced multiple scattering events and therefore arrive at the analysis fiber after traveling varied paths.the diameter of the source fiber is comparable to its separation from the collection fiber. The diffusion model is inappropriate for this geometry; therefore, Monte Carlo simulations are used. In addition, the size of the scattering sites in tissue are expected to be of the same order as the excitation wavelengths, and Mie theory is expected to provide the best description of the scattering and extinction. The authors will present and compare the results of simulations and measurements of the elastic scatter signal for suspensions of latex spheres in hemoglobin solutions of varying concentrations.
Date: May 1, 1995
Creator: Boyer, J.; Mourant, J.R. & Bigio, I.J.
Partner: UNT Libraries Government Documents Department

Biologic response to complex blast waves

Description: Small, bare charges were detonated inside an M59 armored personnel carrier (APC) in an attempt to simulate the complex blast waves generated by the jets from shaped-charge warheads penetrating into armored vehicles. Anesthetized sheep were placed inside the APC at 92- and 122-cm ranges from 57- or 113-g pentolite charges. Pressure-time was measured by pressure transducers either mounted on the animals or free standing at comparable ranges on the opposite side of the vehicle. In general, the waveforms were characterized by an initial shock wave of less than 1-msec duration followed by repeated reflections of decreasing magnitude. No deaths nor lung hemorrhages were observed, but all the animals sustained severe ear injury. Animals subjected to peak overpressures of 1.2 to 2.3 bar from the 113-g explosions also received slight non-auditory blast injuries to the upper respiratory and gastrointestinal tracts; those exposed to peak overpressures of just under 1 bar from the 57-g charges did not. The non-auditory blast injuries inside the APC were more severe than those sustained by sheep at comparable distances from 113-g charges in the open. The results suggested that the biological consequences of a complex wave of the type encountered in this study can be equated approximately to a Friedlander wave with a peak overpressure equal to that of the complex wave and with a total impulse equal to the impulse over the first 2 to 3 msec of the complex wave. 9 refs., 7 figs., 1 tab.
Date: January 1, 1985
Creator: Richmond, D.R.; Yelverton, J.T.; Fletcher, E.R. & Phillips, Y.Y.
Partner: UNT Libraries Government Documents Department

The acute radiation syndrome: A study of ten cases and a review of the problem

Description: In this report ten cases of acute radiation syndrome are described resulting from two accidents occurring at the Los Alamos Scientific Laboratory of unique nature involving fissionable material. These cases are described in considerable detail. The report comprises ten sections. This volume, part II of the report, is comprised of sections entitled: (1) the Biological Basis for the Clinical Response seen in the Acute radiation Syndrome, (2) Clinical Signs and Symptoms, (3) Discussion of Hematological Findings, (4) Chemistry of the Blood and Urine, (5) Discussion of Pathological Findings, and (6) Reconsiderations of the Calculated Radiation Doses in Terms of the Observed Biological Response of the Patients. This report was prepared primarily for the clinician who is interested in radiation injuries and therefore emphasis has been placed on the correlation of clinical and pathological changes with the type of cytogenetic change known to be produced by ionizing radiation.
Date: March 17, 1950
Creator: Hempelmann, L.H. & Lisco, H.
Partner: UNT Libraries Government Documents Department

Physiological parameters for assessing the hazard of exposure to ruthenium radioisotopes

Description: Results are reported from a variety of studies on the absorption by various routes, the distribution, the excretion, and the long term retention of ruthenium-106 in various tissues of the rat. Gastrointestinal absorption of ruthenium is much greater than previously assumed; the maximum permissible concentration of Ru106 in drinking water should be 4 {times} 10{sup {minus}3} {mu}c/ml.
Date: March 1, 1956
Creator: Thompson, R. C.; Weeks, M. H.; Hollis, O. L.; Ballou, J. E. & Oakley, W. D.
Partner: UNT Libraries Government Documents Department

Optical diagnostics based on elastic scattering: An update of clinical demonstrations with the Optical Biopsy System

Description: The Los Alamos National Laboratory has continued the development of the Optical Biopsy System (OBS) for noninvasive, real-time in situ diagnosis of tissue pathologies. Our clinical studies have expanded since the last Biomedical Optics Europe conference (Budapest, September 1993), and we report here on the latest results of clinical tests in gastrointestinal tract. The OBS invokes a unique approach to optical diagnosis of tissue pathologies based on the elastic scattering properties, over a wide range of wavelengths, of the tissue. The use of elastic scattering as the key to optical tissue diagnostics in the OBS is based on the fact that many tissue pathologies, including a majority of cancer forms, manifest significant architectural changes at the cellular and sub-cellular level. Since the cellular components that cause elastic scattering have dimensions typically on the order of visible to near-IR wavelengths, the elastic (Mie) scattering properties will be wavelength dependent. Thus, morphology and size changes can be expected to cause significant changes in an optical signature that is derived from the wavelength-dependence of elastic scattering. The OBS employs a small fiberoptic probe that is amenable to use with any endoscope or catheter, or to direct surface examination. The probe is designed to be used in optical contact with the tissue under examination and has separate illuminating and collecting fibers. Thus, the light that is collected and transmitted to the analyzing spectrometer must first scatter through a small volume of the tissue before entering the collection fiber(s). Consequently, the system is also sensitive to the optical absorption spectrum of the tissue, over an effective operating range of <300 to 950 nm, and such absorption adds valuable complexity to the scattering spectral signature.
Date: October 1, 1994
Creator: Bigio, I. J.; Boyer, J.; Johnson, T. M.; Lacey, J.; Mourant, J. R.; Conn, R. et al.
Partner: UNT Libraries Government Documents Department

The relative physiological and toxicological properties of americium and plutonium

Description: The relative physiological and toxicological properties of americium and plutonium have been studied following their intravenous administration to rats. The urinary and fecal excretion of americium was similar to that of plutonium administered as Pu(N0{sub 3}){sub 4}. The deposition of americium the tissues and organs of the rat was also similar to that observed for plutonium. The liver and the skeleton were the major sites of deposition. Zirconium citrate administered 15 minutes after injection of americium increased the urinary excretion of americium and decreased the amount found in the liver and the skeleton at 4 and 16 days. LD{sub 30}{sup 50} studies showed americium was slightly less toxic when given in the acute toxic range than was plutonium. The difference was, however, too slight to be important in establishing a larger tolerance does for americium. Survival studies, hematological observations, bone marrow observations, comparison of tumor incidence and the incidence of skeletal abnormalities indicated that americium and plutonium have essentially the same chronic toxicity when given on an equal {mu}c. basis. These studies support the conclusion that the tolerance values for americium should be essentially the same as those for Plutonium.
Date: November 15, 1951
Creator: Carter, R.E.; Busch, E. & Johnson, O.
Partner: UNT Libraries Government Documents Department

The role of intestinal injury in hematopoietic gamma ray mortality

Description: Leukemia patients typically have low granulocyte counts as do those with aplastic anemia. A review of the literature on these latter patients quickly indicates that they live much longer than leukemic patients with the same counts. To check this numerically, the survival times for 12 aplastic anemia patients reported in 1934 were compared with the expected survival times for more recent patients using methods employed to compute the probabilities. On the average, the aplastic anemia patients lived almost ten times as long as the leukemia patients would have been expected to live. 5 refs., 2 figs.
Date: December 1, 1987
Creator: Broyles, A.A.
Partner: UNT Libraries Government Documents Department

Estimates of internal-dose equivalent from inhalation and ingestion of selected radionuclides

Description: This report presents internal radiation dose conversion factors for radionuclides of interest in environmental assessments of nuclear fuel cycles. This volume provides an updated summary of estimates of committed dose equivalent for radionuclides considered in three previous Oak Ridge National Laboratory (ORNL) reports. Intakes by inhalation and ingestion are considered. The International Commission on Radiological Protection (ICRP) Task Group Lung Model has been used to simulate the deposition and retention of particulate matter in the respiratory tract. Results corresponding to activity median aerodynamic diameters (AMAD) of 0.3, 1.0, and 5.0 ..mu..m are given. The gastorintestinal (GI) tract has been represented by a four-segment catenary model with exponential transfer of radioactivity from one segment to the next. Retention of radionuclides in systemic organs is characterized by linear combinations of decaying exponential functions, recommended in ICRP Publication 30. The first-year annual dose rate, maximum annual dose rate, and fifty-year dose commitment per microcurie intake of each radionuclide is given for selected target organs and the effective dose equivalent. These estimates include contributions from specified source organs plus the systemic activity residing in the rest of the body; cross irradiation due to penetrating radiations has been incorporated into these estimates. 15 references.
Date: January 1, 1982
Creator: Dunning, D.E.
Partner: UNT Libraries Government Documents Department

Mechanisms of calcium transport in small intestine. Progress report, March 1, 1976--September 30, 1977. [Chickens, rats, lead]

Description: Progress is reported on the following research projects: subcellular location of 1,25-dihydroxyvitamin D/sub 3/(1,25-(OH)/sub 2/D/sub 3/) in intestine of chickens; studies on receptor proteins in intestine for 1,25-(OH)/sub 2/D3; studies on intestinal cytosol receptors in chickens and rats; control of intestinal calcium transport; effect of calcitonin on 25-OH-D/sub 3/-1-hydroxylase; isolation and identification of the active principle of Solonum glaucophyllum, the South American plant that causes metastatic calcification and death to grazing animals; and studies on lead transport in vitro and in vivo. (HLW)
Date: January 1, 1977
Creator: DeLuca, H. F.
Partner: UNT Libraries Government Documents Department

Mechanisms of calcium transport in small intestine. Overall review of the contract, September 1, 1972--March 1, 1976

Description: Progress is reported in the following areas of research: role of high molecular weight protein in calcium transport in vitamin D deficient chicks; subcellular localization of 1,25-(OH)/sub 2/D/sub 3/; receptor proteins for 1,25-(OH)/sub 2/D/sub 3/; effects of high calcium diet, strontium diet, EHDP, and parathyroidectomy on intestinal calcium transport in chicks; effects of analogs of 1,25-(OH)/sub 2/D/sub 3/ on intestinal calcium transport; discrimination by chicks against vitamin D/sub 2/ compounds by metabolism; effects of extract of Solanum malacoxylan on intestinal calcium absorption in nephrectomized rats; and role of vitamin D in phosphate transport reactions in the intestine. (HLW)
Date: January 1, 1976
Creator: DeLuca, H. F.
Partner: UNT Libraries Government Documents Department

INREM II: a computer implementation of recent models for estimating the dose equivalent to organs of man from an inhaled or ingested radionuclide

Description: This report describes a computer code, INREM II, which calculates the internal radiation dose equivalent to organs of man which results from the intake of a radionuclide by inhalation or ingestion. Deposition and removal of radioactivity from the respiratory tract is represented by the ICRP Task Group Lung Model. A four-segment catenary model of the GI tract is used to estimate movement of radioactive material that is ingested or swallowed after being cleared from the respiratory tract. Retention of radioactivity in other organs is specified by linear combinations of decaying exponential functions. The formation and decay of radioactive daughters is treated explicitly, with each radionuclide species in the chain having its own uptake and retention parameters, as supplied by the user. The dose equivalent to a target organ is computed as the sum of contributions from each source organ in which radioactivity is assumed to be situated. This calculation utilizes a matrix of S-factors (rem/..mu..Ci-day) supplied by the user for the particular choice of source and target organs. Output permits the evaluation of crossfire components of dose when penetrating radiations are present. INREM II is coded in FORTRAN IV and has been compiled and executed on an IBM-360 computer.
Date: February 2, 1978
Creator: Killough, G.G.; Dunning, D.E. Jr. & Pleasant, J.C.
Partner: UNT Libraries Government Documents Department

Use of total beta counts to estimate GI tract dose rates

Description: It was the practice for several years to estimate the potential dose rate to the gastrointestinal from sanitary water sources by evaluating the results of radiochemical analysis of individual nuclides. The proposed method estimates the GI tract dose from Pasco and Richland domestic water from measurements of the total beta activity, and permits more frequent and more economical evaluation of a variable source of radiation exposure. Beginning with 1964 data, the GI tract dose rate for Richland and Pasco sanitary water has been obtained by multiplying the total beta count by a conversion factor derived from the historical relationship between the radiochemical analyses and the total beta counts. Either the accumulation of more data or changes in the relative abundance of the more significant nuclides in the water may result in changes in this factor.
Date: October 25, 1965
Creator: Hall, R. B.
Partner: UNT Libraries Government Documents Department

REDIQ: a computer program for estimating health effects from inhalation and ingestion of radionuclides

Description: The computer program REDIQ calculates the risk equivalence of dosage from internally deposited radionuclides to dosage from external whole-body irradiation. The calculation gives an estimate of the microcurie intake per nuclide that would result in a risk equivalent to receiving 1 rem of external whole-body irradiation. The program allows for internal deposition resulting from either inhalation of radioactive aerosols or ingestion of contaminated food. The inhalation portion of REDIQ was taken from the computer program DACRIN, which uses the models of the respiratory tract adopted by the Task Group on Lung Dynamics. REDIQ also uses a simple exponential model for retention by an organ of interest, and the gastrointestinal tract model of the International Commission on Radiological Protection (ICRP). For each nuclide specified, the program first calculates the radiation dose per microcurie intake by inhalation or ingestion to any of 23 organs and tissues. A maximum of 10 organs may be specified for any one case. The values for dose per microcurie intake are then coupled with relative risk values for each organ being considered, to arrive at the estimated intake equivalent to 1 rem of external whole-body irradiation.
Date: December 1, 1976
Creator: Strenge, D. L.; Watson, E. C. & Kennedy, W. E.
Partner: UNT Libraries Government Documents Department

Delayed radiation injury of gut-exposed and gut-shielded mice. II. The decrement in life span

Description: Two mouse strains (RF/J and C57B1/6J) were exposed to x-ray doses totaling 400, 800, and 1200 rad. Total doses were given in 200-rad fractions at 7-day intervals to the whole body, gut only, or bone tissue with the gut shielded. Animals were anesthetized during exposure. Two control groups were used. A sham control group was anesthetized but not exposed to x rays, and another control group received neither anesthesia nor x-radiation. All mice were retained in a standard laboratory environment for observations on life span and histopathology at death. Life shortening was observed in all irradiated groups of strain RF/J mice and was attributed primarily to an increase in incidence and/or earlier onset of neoplasia. Life shortening was observed in the C57B1/6J whole-body exposed mice, but the effect appeared to be noncarcinogenic. Shielding of the bone or gut tissue proved to have a 100% sparing effect in strain C57 mice and none in strain RF mice. In both mouse strains, the sham control groups (anesthetized but not irradiated) showed approximately 8% life shortening below the non-anesthetized control groups and increased incidences of neoplasia of approximately 40%, suggesting that sodium pentabarbital may be as carcinogenic as x-radiation.
Date: January 1, 1978
Creator: Spalding, J.F.; Archuleta, R.F. & Prine, J.R.
Partner: UNT Libraries Government Documents Department

Effects of pions on normal tissues

Description: Verification of the uniform biological effectiveness of pion beams of various dimensions produced at LAMPF has been made using cultured mammalian cells and mouse jejunum. Normal tissue radiobiology studies at LAMPF are reviewed with regard to biological beam characterization for the therapy program and the current status of acute and late effect studies on rodents. (ACR)
Date: January 1, 1981
Creator: Tokita, N.
Partner: UNT Libraries Government Documents Department

New cholescintigraphic agent: ruthenium-97-DISIDA

Description: These studies demonstrate the first application of Ru-97-DISIDA in human subjects. High quality images were obtained. Scintigraphic findings in patients with hepatobiliary disorders were consistent with the biodistribution data obtained in experinmental animals and with other imaging procedures and clinical findings. Administration of Ru-97-DISIDA I.V. and of a solid test meal labeled with Tc-99m-Sulfur Colloid allowed simulateneous detection and quantification of deodenogastric reflux and determination of the gastric emptying rate. This represents an advantage as compared to the currently used techniques which necessitate two separate studies if a solid meal is used, or would mandate a liquid meal for a simultaneous study. The excellent nuclear decay characteristics of Ru-97 (tl/2 69.6 h, gamma 216 keV, 86%, no betas) permit delayed study of the hepatobiliary system with considerably less radiation exposure than I-131 Rose Bengal and with a marked improvement in image quality. 5 refs., 3 figs., 3 tabs.
Date: June 1, 1986
Creator: Zanzi, I.; Srivastava, S.C.; Meinken, G,E.; Robeson, W.; Mausner, L.F.; Fairchild, R.G. et al.
Partner: UNT Libraries Government Documents Department