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in subjects: "Lung Clearance"

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Kinetics of reversible-sequestration of leukocytes by the isolated perfused rat lung

The kinetics and morphology of sequestration and margination of rat leukocytes were studied using an isolated perfused and ventilated rat lung preparation. Whole rat blood, bone marrow suspension, or leukocyte suspensions, were used to perfuse the isolated rat lung. The lung was also perfused with latex particle suspensions and the passage of particles through the lung capillaries was studied. When a leukocyte suspension was perfused through the lung in the single-pass mode, the rate of sequest… more

Date: August 1, 1980

Creator: Goliaei, B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The revised International Commission on Radiological Protection (ICRP) dosimetric model for the human respiratory tract

A task group has revised the dosimetric model of the respiratory tract used to calculate annual limits on intake of radionuclides. The revised model can be used to project respiratory tract doses for workers and members of the public from airborne radionuclides and to assess past exposures. Doses calculated for specific extrathoracic and thoracic tissues can be adjusted to account for differences in radiosensitivity and summed to yield two values of dose for the respiratory tract that are appli… more

Date: May 1, 1992

Creator: Bair, W.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Clearance of Tc-99m DTPA Aerosol from Coal Miners' Lungs

Alterations in regional epithelial permeability were assessed in 22 retired West Virginia coal miners' lungs by measuring the clearance of inhaled 0.5-..mu..m Tc-99m DTPA aerosol. Activity was measured in both lungs and in regions of interest placed over the lung periphery in the apical, middle, and basal portions of each lung. Clearance rates (T/sub 1/2/) for 5 nonsmokers, 8 ex-smokers, and 9 smokers were significantly faster than for comparable subjects measured elsewhere, who were not coal m… more

Date: July 1, 1985

Creator: Susskind, H.; Brill, A. B. & Harold, W. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Specific surface area behavior of a dissolving population of particles. Augmenting Mercer Dissolution Theory

Specific surface area (Sp) measurements were made on two uranium oxide aerosol materials before and after in vitro dissolution studies were performed on the materials. The results of these Sp measurements were evaluated relative to predictions made from extending Mercer dissolution theory to describe the Sp behavior of a dissolving population of particles.

Date: January 1, 1986

Creator: Scripsick, R.C. & Rothenberg, S.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation-induced mesotheliomas in rats

Mesotheliomas have been reported in rats that inhaled plutonium, but these tumors have not been extensively studied. To investigate a possible role for inhaled radionuclides in the induction of mesotheliomas, four life-span studies conducted at the Inhalation Toxicology Research Institute are reviewed. A total of 3076 F344 rats were exposed by inhalation to aerosols of {sup 239}PuO{sub 2}, mixed uranium-plutonium oxide, or {sup 144}CeO{sub 2}. Results showed that a low incidence of pleural meso… more

Date: January 1, 1990

Creator: Hahn, F. F.; Haley, P. J.; Hubbs, A. F.; Hoover, M. D. & Lundgren, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Translocation of particles to the pleural space and tracheobronchial lymph nodes following lung deposition

The translocation of particles from the alveolar compartment to the pleural space and tracheobronchial lymph nodes was investigated in rats over a 30 day period following the intrapulmonary instillation of 4 x 10/sup 8/ polystyrene microspheres (1.9 ..mu..m dia.). In initial studies, approx. =10/sup 4/ particles were found in the pleural space compartment on Days 1, 14 and 30 after particle deposition, and most of these were cell-associated. Subsequent pleural space studies indicated, however, … more

Date: January 1, 1985

Creator: Lehnert, B. E.; Valdez, Y. E. & Hyler, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Human data demonstrating extra long retention of plutonium in the lung

Case histories are presented of 10 humans with inhalation depositions of Pu in which the Pu is retained in the lung or pulmonary lymph system for extremely long periods. The retention half-times range from 5000 to at least 20,000 d for most (in some cases all) of the initial deposition. In no case was a clearance half-time in the hundreds of days observed. The form of Pu involved in these cases is believed to be calcined Pu oxide. 9 refs., 1 fig., 2 tabs.

Date: January 1, 1991

Creator: Bihl, D.E.; Carbaugh, E.H. & Sula, M.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Therapy for incorporated radionuclides: scope and need

In the United States the recent termination of funding for research on therapy for incorporated radionuclides has virtually halted progress on improved or new agents and procedures for removing radioactivity from the body. Research was eliminated, but is still needed on new removal agents, improved delivery system, in vitro test systems, and the toxicology of treatments. For many radionuclides, no adequate therapy exists. The relationship between radionuclide removal and reduction in cancer ris… more

Date: March 1, 1981

Creator: Smith, V. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dissolution rates of uranium compounds in simulated lung fluid

Maximum dissolution rates of uranium into simulated lung fluid from a variety of materials were measured at 37/sup 0/in the where f/sub i/ is in order to estimate clearance rates from the deep lung. A batch procedure was utilized in which samples containing as little as 10 ..mu..g of natural uranium could be tested. The materials included: products of uranium mining, milling and refining operations, coal fly ash, an environmental sample from a site exposed to multiple uranium sources, and purif… more

Date: January 1, 1981

Creator: Kalkwarf, D. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Histopathologic, morphometric, and physiologic investigation of lungs of dogs exposed to uranium-ore dust

The most consistent pulmonary-function change attributed to carnotite uranium-ore-dust exposure (at 15 mg/m/sup 3/, for 4 h/day, 5 days/week) is an increased slope of the single-breath N/sub 2/ washout curve, suggesting an uneven distribution of ventilation. This change was observed in dogs exposed for less than 1 year and continued through 4 years of exposure. Measurements of pulmonary resistance, after 27, 40 and 47 months exposure, showed slight age-related changes and increasing differences… more

Date: January 1, 1981

Creator: Cross, F. T.; Filipy, R. E.; Loscutoff, S. M.; Mihalko, P. J.; Palmer, R. F. & Busch, R. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Respiratory tract tumors in Syrian hamsters following inhalation of Pu--ZrO/sub 2/ particles. [Comparison with incidence of lung tumors following intravenous injection of PuO/sub 2//ZrO/sub 2/ microspheres]

Inhalation of radionuclide-bearing particles remains one of the most intensely pursued problems concerning the nuclear industry. This route of entry is generally accepted as the most probable, in case of human exposure, with ingestion being the other prominent source of concern. Many laboratory investigations, such as those reported here, continue to evaluate the possible consequences that may present health problems to the public domain. Syrian hamsters of both sexes received either inhaled (I… more

Date: January 1, 1979

Creator: Thomas, R. G. & Smith, D. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Comparison of two lung clearance models based on the dissolution rates of oxidized depleted uranium

An in-vitro dissolution study was conducted on two respirable oxidized depleted uranium samples. The dissolution rates generated from this study were then utilized in the International Commission on Radiological Protection Task Group lung clearance model and a lung clearance model proposed by Cuddihy. Predictions from both models based on the dissolution rates of the amount of oxidized depleted uranium that would be cleared to blood from the pulmonary region following an inhalation exposure wer… more

Date: October 1, 1984

Creator: Crist, K. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Two /sup 238/Pu inhalation incidents

Two employees inhaled significant amounts of /sup 238/Pu in separate unrelated contamination incidents in 1977. Both acute exposure incidents are described and the urine, feces, and in-vivo chest count data for each employee. Case B (/sup 238/PuNO/sub 3/) received 24 DTPA treatments beginning the day of the incident while, for medical reasons, Case A (/sup 238/PuO/sub 2/) received no therapy.

Date: June 1, 1978

Creator: Fleming, R. R. & Hall, R. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pulmonary toxicology of respirable particles. [Lead abstract]

Separate abstracts were prepared for the 44 papers presented in these proceedings. The last paper (Stannard) in the proceedings is an historical review of the field of inhalation toxicology and is not included in the analytics. (DS)

Date: September 1, 1980

Creator: Sanders, C. L.; Cross, F. T.; Dagle, G. E. & Mahaffey, J. A. (eds.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Pulmonary retention of coal dusts

The principal objectives of this study were: to determine, quantitatively, coal dust retention times in the dog lung; to test the appropriateness of a pulmonary retention model which incorporates first order rate coefficients obtained from in vitro and in vivo experiments on neutron-activated coal; to acquire a temporal description of the pulmonary disposition of the retained coal dust, and to compare the behavior of two different Pennsylvania coals in the foregoing regards. The principal findi… more

Date: January 1, 1980

Creator: Morrow, P.E.; Gibb, F.R.; Beiter, H.; Amato, F.; Yuile, C. & Kilpper, R.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Solubility classification of airborne products from uranium ores and tailings piles. [Solubility parameters are based on airborne and seived ground dust samples]

Airborne products generated at uranium mills were assigned solubility classifications for use in the ICRP Task Group Lung Model. No significant difference was seen between the dissolution behavior of airborne samples and sieved ground samples of the same product. If the product contained radionuclides that dissolved at different rates, composite classifications were assigned to show the solubility class of each component. If the dissolution data indicated that a radionuclide was present in two … more

Date: January 1, 1979

Creator: Kalkwarf, D. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Pulmonary macrophages: Phenomena associated with the particle overload'' condition

Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-med… more

Date: January 1, 1993

Creator: Lehnert, B. E.; Sebring, R. J. (Los Alamos National Lab., NM (United States)) & Oberdoerster, G. (Rochester Univ., NY (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Revision of the ICRP dosimetric model for the human respiratory tract

Although the dosimetric model of the respiratory tract used in ICRP Publication 30 had not been shown to be seriously deficient for the purpose of calculating Annual Limits on Intake (ALIs) for workers, the availability of new information led the ICRP in 1984 to create a special Task Group to review the dosimetric model of the respiratory tract and, if justified, propose revisions or a new model. The Task Group directed its efforts toward improving the model used in Publication 30 rather than d… more

Date: December 1, 1990

Creator: Bair, W.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Lung-clearance classification of radionuclides in calcined phosphate rock dust

Lung-clearance classifications for /sup 210/Pb and /sup 210/Po in airborne dust from elemental phosphorus plants were estimated for use with the lung clearance model proposed by the ICRP Task Group on Lung Dynamics. Estimates were based on measurements of dissolution rates for these radionuclides from sized dust samples into simulated lung fluid at 37/sup 0/C. The estimates were expressed in the classification terms of the model, i.e., D, W and Y, indicating lung clearance half-times of 0 to 10… more

Date: August 1, 1984

Creator: Kalkwarf, D. R. & Jackson, P. O.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A linear, time-varying simulation of the respiratory tract system

These results show that regional deposition efficiencies of inhaled particles are highly dependent on the level of physical activity in all the spectrum of thermodynamic and aerodynamic aerosol particle sizes; also it was shown that for particles in the aerodynamic size range, the values of regional deposition efficiencies at the inner regions of the lung are highly dependent on age. In addition, the shape of regional deposition efficiency curves as a function of particle size have a similar be… more

Date: November 1, 1992

Creator: Hernandez, O.

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Report of work performed by Dr. Ivancica Trosic in response to procurement request No. 4478H University of California, Los Alamos National Laboratory, Los Alamos, New Mexico

Rats were intratracheally instilled with polystyrene microspheres and/or asbestos particles (0.5 mg) suspended in PBS. Six animals from each group were dispatched n days 1, 7, 30, 80 and 150 days after their respective instillations. Their lungs were lavaged, and quantifications of lavaged fluorescent microspheres, analyses of distributions of microspheres in lung, phagocytes by type, quantification of unlavaged lung burdens of microspheres, and quantification of tracheobronchial lymph mode bur… more

Date: July 1, 1994

Creator: Trosic, I.

Item Type: Report

Partner: UNT Libraries Government Documents Department