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Biomedical subjects

C E Putman

Publications and source records attributed to C E Putman.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Tantalum oxide and alveolar macrophage function.

The alveolar macrophage (AM) has been cited as a potential source for clearing tantalum from the lungs following bronchography. We studied the short term effects of tantalum oxide on rabbit AM viability and metabolism in vitro. AM phagocytosed tantalum oxide particles without cytotoxicity and with a significant rise in glucoxe oxidation. These results suggest that the AM represents an important vehicle for clearance of tantalum particles from airways in vivo.

Animals↗
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Tantalum oxide, silica and latex: effects on alveolar macrophage viability and lysozyme release.

Tantalum an experimental bronchographic material, may be retained in the lungs for a prolonged period following bronchography. The alveolar macrophage (AM) is a cell with potential for clearing tantalum particles from the airways. We studied the in vitro effects of tantalum oxide and two other particles, silca and latex, on rabbit AM viability and lysozyme release over 30 hours. Results indicate: 1) tantalum oxide, silica, and latex particles are ingested by rabbit AM in culture; 2) tantalum oxide and silica are both toxic to AM in vitro; and 3) tantalum oxide exerts its toxic effects less rapidly on AM than does silica. On the basis of these in vitro culture results we conclude that tantalum oxide may be toxic to alveolar macrophages in vivo. Delayed lung clearance of tantalum oxide particles may be due in part to their toxic effects on alveolar macrophages.

Animals↗
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Transcatheter electrocoagulation of the pulmonary artery: an experimental model in dogs for studying pulmonary thrombosis.

Transcatheter electrocoagulation (TCEC) has been shown to produce permanent arterial occlusion. This study was performed to evaluate the potential of using TCEC of the pulmonary artery as an experimental model of pulmonary thromboembolism. Fourteen lobar or first-order pulmonary arteries were occluded in ten dogs in the acute studies. Eight pulmonary arteries were occluded in eight dogs that were sacrificed 25 to 85 days after TCEC. There were permanent occlusions in seven, and all seven evidence of pulmonary infarction. The animals tolerated the procedure well. The technique may have merit as an experimental model for studying pulmonary thrombosis and infarction.

Animals↗
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A computed tomographic study of the dog lung during hemorrhagic shock and after resuscitation.

A shock model was used to explore the capability of computed tomography (CT) to detect changes in lung density during hypovolemia and after resuscitation. The same level of the lower thorax was scanned repeatedly during base-line, shock (aortic pressure 60 mmHg), and after resuscitation with shed blood. The average baseline CT number (+/- SEM) for 5 areas of interest for four prone dogs was -754 +/- 16 (air = -1000, water = 0). This decreased 7.4% to -810 +/- 15 (P less than .05) during shock. After resuscitation CT density was -773 +/- 17 or 2.5% less than baseline (P greater than .1). A dorsal to ventral gradient of increasing CT density during baseline was maintained in all five areas during shock and post-resuscitation. From baseline to shock there were also significant changes in heart rate, mean aortic pressure, cardiac output, and vascular volume. Extravascular lung volume after resuscitation was equal to baseline volume. We conclude that CT is sufficiently sensitive to detect rapid physiological changes leading to increased or decreased lung density.

Animals↗
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Chest radiographic-pathologic correlation in adult leukemia patients.

A radiographic-pathologic correlation study of adult leukemia patients was conducted to determine the frequency and radiographic appearance of leukemic involvement and related complications within the chest. One hundred thirteen autopsy protocols were examined. Radiographic correlation was obtained in 60 of these cases. Autopsy pulmonary findings included hemorrhage in 74% of the cases, infectious infiltrates in 67%, edema or congestion in 57%, and leukemic infiltration in 26%. Only 5% of the chest radiographs were normal. Alveolar or interstitial abnormalities were identified in 90%, pleural effusion in 40%, and lymphadenopathy in 17%. Correlation demonstrated pulmonary infection to be by far the most common cause of radiographic opacity. Because of its frequent occurrence, high associated mortality, and potential reversibility, pneumonia must always be considered first in the differential diagnosis of radiographic opacity in these patients.

Adult↗
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Analysis of the density of pleural fluid analogs by computed tomography.

A noninvasive method for differentiating transudative and exudative pleural effusions could make thoracentesis unnecessary in many cases. Since computed tomography (CT) can be used to measure tissue densities, it has a potential use in assessing density of intrathoracic fluid. This study was performed to test this possibility. Plastic syringes containing water, saline, and three saline-albumin solutions with densities up to 1.021 g/cc were scanned individually in air, in a chest phantom, and in a dog thorax during apnea. We found significant positive correlations between specific gravity and CT density; coefficients ranged from 0.85 to 0.99. Regression lines for the different test conditions were not statistically different. However, CT number variability, as indicated by the average standard deviation (SD), did differ for the test conditions: 1) Syringes alone, average SD was 3.8 HU; 2) chest phantom, average SD was 5.5 HU adjacent to rib and 5.8 HU anterior to vertebral column; 3) dog chest average SD was 19.2 HU with heart motion and 9.4 HU without heart motion. These results suggest that heart motion is a major factor in CT number variability in vivo, and that differentiation of transudates from exudates is not possible with current CT methods.

Animals↗
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Hydrostatic pulmonary edema. An analysis of lung density changes by computed tomography.

The computed tomographic (CT) appearance of pulmonary edema induced by elevated left atrial (LA) pressure was examined. Dogs, in the prone position, were scanned during suspended ventilation at functional residual capacity. A surgically implanted LA balloon was inflated to elevate LA pressure for 30 to 140 minutes to a mean pressure of 29.8 mm Hg. Lung water, measured gravimetrically, averaged 14.7 ml/kg body weight compared with 5.7 ml/kg in nonedema control dogs. Lung density in dogs with edema was 69.5% higher than base-line density, while in the control group final lung density was only 4% higher than base line. Analysis of regional density indicated that there were greater increases in density in more central and dependent (ventral) zones of the lung and relatively smaller increases in nondependent (dorsal) peripheral zones. These results are in contrast to the previously reported pattern of density change seen with oleic acid injury in which density increases were primarily in peripheral zones of the lung.

Animals↗
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Morphology of oleic acid-induced lung injury. Observations from computed tomography, specimen radiography, and histology.

Previously, we reported that oleic acid infusion in dogs produced a patchy and predominantly peripheral increase in lung density. The present study examines in more detail the morphology of the early stages of development of the oleic acid lesion using computed tomography (CT), specimen radiography, and conventional histology. Dogs were sacrificed 10, 30, 60, and 240 minutes after infusion of oleic acid (.05 ml/kg). After freezing in dry-ice, the thorax was scanned and cut into 1-cm thick sections. Frozen sections were then contact radiographed and sampled for histology. Within 10 minutes of infusion, subtle increases in peripheral lung density were visible on the contact radiographs. Patchy areas of peripheral density, resembling secondary lobules, were especially prominent 60 and 240 minutes after infusion. These lesions were often clearly associated with the distal bronchovascular structures. Histologic signs of edema were present in all animals sacrificed 30 or more minutes after receiving oleic acid. These correlative studies provide additional insight into the early subgross development of oleic acid-induced injury by showing the relationship between the developing edema and the bronchovascular structure of the lung.

Animals↗
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Computed tomographic evaluation of lesions in the thoracic apex.

Fifty patients with clinically suspected lesions of the chest apex underwent computed tomography (CT) and plain film (PF) examinations in an attempt to define the underlying etiology as benign or malignant. CT was slightly more sensitive in diagnosing malignancy (90%) compared with PF (77%), with a higher predictive value of a negative test (85% vs. 70%), although the differences were not statistically significant. The specificity and predictive value of a positive test were similar for CT and PF. CT's advantage was better elucidation of the soft tissues of the chest apex. CT provided additional information beyond PF in 17/20 patients with benign conditions and in 29/30 patients with cancer. In 21 of these 29 cancer patients, CT findings significantly altered subsequent management.

Female↗
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A CT technique to evaluate the development of carcinogen-induced neoplasia in the rat liver.

Hepatocellular neoplasms, including neoplastic nodules (NN), are the most commonly induced tumors resulting from chemical carcinogen evaluation. Our objective was to image neoplastic nodules using computed tomography. In a preliminary study using rats with diethylnitrosamine (DEN) induced tumors, lesions smaller than 1.5 cm were difficult to identify by CT. Since NN do not take up excess iron whereas normal liver does accumulate iron, we studied iron as a CT contrast material. Hemochromatosis was induced in 15 control rats by subcutaneous injections of iron dextran. A linear increase in iron-loading dose produces a linear CT liver enhancement (r = 0.97): 68, 80, 84, 94, and 104 HU at 0, one, two, four, and six weeks, respectively. No loss of enhancement was noted ten weeks later. Rat hepatic tissue was chemically analyzed after a similar iron-loading regimen. The iron concentration (microgram/g hepatic tissue) progressively increased during the first four weeks of loading and remained stable for three weeks following iron-loading. Four animals that had been given DEN and iron were examined by CT scanning to detect small NN. Iron-enhanced CT allowed the visualization of small lesions (less than 5 mm). Histopathologic sections confirmed a homogeneous pattern of iron uptake in normal liver with a deficiency of iron in NN. We conclude that CT scanning following iron-loading is a noninvasive method to detect small nodules and may provide a method to study the progression or regression of small liver nodules in rodents.

Animals↗
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Double-blind comparison of iodamide and diatrizoate for excretory urography.

A double-blind comparison of meglumine iodamide and Renografin 60 (52% meglumine diatrizoate and 8% sodium diatrizoate) for bolus excretory urography was performed. Doses of 0.8 cc/kg. to a maximum of 55 cc were administered to fifty patients, twenty-five receiving each drug.There is a suggestion that iodamide may be superior to diatrizoate in pyelocalyceal opacification while being equal to diatrizoate in parenchymal opacification and in types and severity of side-effects.

Adolescent↗
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Clinical comparison of two contrast agents for oral cholecystography: radiologic efficacy and drug safety of iopanoic acid and iopronic acid.

Oral doses of either iopronic acid (4.5 g Oravue, Squibb) or iopanoic acid (3 g Telepaque, Winthrop) were given to 98 patients requiring cholecystography. Radiographs were taken 13 to 16 hours after treatment showed good to excellent gallbladder opacification in 44 percent of patients after the first dose of iopronic acid and in an additional 29 percent after a second dose. Similar opacification occurred in 42 percent of patients after the first dose of iopanoic acid and in 34 percent after a second dose. Drug-related abnormalities in blood and urine tests occurred about equally in both groups and one patient in each group exhibited a clinically adverse reaction (diarrhea). Thus, the performance (radiographic efficacy and drug safety) of the new contrast agent, iopronic acid, was similar to a widely used drug, iopanoic acid.

Administration, Oral↗