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Biomedical subjects

P Lord

Publications and source records attributed to P Lord.

35 records · Page 2Linked to original sources
PubMed1985

Comparative uptake of 67Ga and 99mTc MDP in rabbits with a benign noninfected bone lesion (fracture).

Mid-shaft fractures of the radius and ulna were produced in 3 to 4 kg New Zealand white rabbits and quantitative uptake of 99mTc MDP and 67Ga determined at 11, 18, 25, 32, 51, and 78 days following fracture. Two hundred microCi of 67Ga was administered 24 hours prior to sacrifice and 1.5 mCi 99mTc MDP 2 hours prior to sacrifice. Specific activity ratios (SARs) were determined between fracture and control sides for bone, muscle and skin. SARs for bone were surprisingly similar for 99mTc MDP and 67Ga, reaching peak values of 6.07 +/- 0.64 (99mTc 18 days); 6.58 +/- 0.90 (67Ga 32 days), subsequently decreasing to minimum values at 78 days postfracture (99mTc MDP 2.25 +/- 0.14; 67Ga 2.18 +/- 0.08). There was no statistically significant difference in SAR for 99mTc MDP vs. 67Ga in bone at any time after fracture. Whole sections of limb were resected on selected animals and activity ratios determined for these sections as a function of the contribution of activity from the various tissues in the volume of interest. Total activity ratios of 67Ga were lower than bone SARs as a result of the contribution of activity from muscle and skin. Thus the apparent lower activity ratios noted on 67Ga images compared with 99mTc MDP images in this fracture model were not due to differences in bone SARs but rather due to the higher soft tissue background activity contribution in the 67Ga images.

Animals↗
PubMed1984

Tracheobronchial gland profiles in four segmental airways.

Previously described methods of measuring the amount of submucous gland in the trachea and bronchi have various disadvantages. These have been overcome by a method in which area point counting has been used to obtain a new unit, Vgl mm3/mm2, the volume of gland per unit airway surface area; Vgl has been obtained for the trachea, the main and lobar bronchi, and for successive airway generations down 4 segmental bronchi (the left lingular , the left anterior basal, the right middle medial, and the right anterior basal) from 3 nonsmokers, and presented in profile form. The profiles have a distinctive shape, not previously appreciated, with a rise to a proximal peak and then a striking fall to low Vgl values in the subsegmental bronchi. The shape of the profile is intriguing, but at present the information required to answer the questions it raises is not available. As there were no significant differences between the profiles of the 4 airways in the individual subjects, any one of the 4 airways may be chosen to give a representative profile for an individual subject.

Adult↗
PubMed1975

Acute pulmonary edema and seizures in hunting dogs.

The clinical and radiographic appearance of acute pulmonary edema in three hunting dogs are reported. The etiology is discussed. The conclusion was drawn that the cause of pulmonary edema was probably neurogenic, probably induced by hypoglycemia. Prevention and treatment are discussed.

Acute Disease↗
PubMedDate not supplied

The influence of heparin on the in vivo distribution of IN-111 labeled platelets.

We investigated the influence of heparin (H) (bolus i.v.; 100-200 I.U./kg.) on the in vivo distribution and accumulation of autologous indium-111-platelets (In-111-P) on experimental pulmonary emboli (PE) in a canine model. Using a thrombin clot formation technique, we induced pulmonary emboli in ten dogs; three dogs were treated with heparin (H), and seven were not (NH). Of five control animals without PE, two were heparinized (H-control) and three were not (NH-control). Animals were sacrificed after 4 to 5 hours of serial blood sampling and sequential scintigraphy. We observed that heparin increased the recovery of In-111-P in the peripheral blood circulation of both control and PE dogs, and reduced the liver uptake of In-111-P in the PE dogs. No PE could be detected while the dogs were fully heparinized, but as the heparin effect dissipated over time, the deposition of In-111-P permitted the scintigraphic detection of PE.

Animals↗
PubMedDate not supplied

Effects of a digital filter on detectability of a phantom lesion in a scintigram of the equine tarsus.

The aim of this study was to examine the effects of a digital filter on the detectability of a phantom lesion in a scintigram of the equine tarsus. Lateral images containing 50, 100, 150, 500, or 1000 kcounts were acquired. A created phantom lesion of 0 (normal), 10, 15, 20, or 30% increased intensity relative to local background was placed in the centrodistal tarsal joint area in the images of different count levels. Duplicate images were filtered with a Metz filter. The complete set of filtered and unfiltered images totaling 180 images was projected as slides to a group of 9 observers. The sensitivity in 50 and 100 kcount images was improved by applying the filter. Digital filtering increased the false positive fraction at all count levels but this effect was most pronounced in 500 and 1000 kcount images. Based on receiver operating characteristic analysis, filtering of a 50 kcount image improved image quality to that of a 150 kcount image.

Animals↗
PubMedDate not supplied

Scintigraphic evaluation of the thoracic spine in the asymptomatic riding horse.

Scintigraphic evaluation of the spinous processes of the equine spine has been done by subjective evaluation of radiotracer uptake in clinically abnormal horses. To determine the range of variation in asymptomatic riding horses, 33 normal horses were examined. Two 60 degrees oblique views of the thoracic and lumbar spine were evaluated subjectively, and a semi quantitative method based on standardized regions of interest in each spinous process in T10-L3 was also applied. A ratio between each spinous process and a reference area (Rib 15 or 16) was calculated. The effects of two different color displays and a smoothing filter were assessed. The results of the subjective evaluation was compared to the calculated ratios, and the associations between age, gender, weight, height, use and increased radiotracer uptake, and ratios were analyzed. No significant association was found between age, gender, weight, height, use and increased radiotracer uptake, or ratio. One or more areas of increased radiotracer uptake between T13 and T18 were common in the asymptomatic riding horse, which may have implications for the interpretation of clinical patients. The blue, green and red color display had a higher sensitivity for detecting increased radiotracer uptake compared to the continuous grayscale. The smoothing filter used in this study had no effect on the detection of areas with increased radiotracer uptake. The association between the results of the subjective evaluation and the semi quantitative method was apparent when analyzed in T13-17. To evaluate if the semi quantitative method can replace the subjective evaluation, studies on clinically affected horses are necessary.

Animals↗
PubMedDate not supplied

Occurrence of occlusive intimal changes in an expanded polytetrafluoroethylene graft.

A case report is presented demonstrating pathologic changes in the neointima that formed when a polytetrafluoroethylene (PTFE) graft was placed in a 35 year old white male with severe arteriosclerosis. Representative sections of the patient's artery and graft were taken which demonstrated considerable smooth muscle proliferation in both along with full wall healing in the latter. Partial oclusion of the total length of the PTFE graft by a process similar to that occurring in the patient's own arteriosclerotic arteries was found. The consistency and extent of the involvement (> 10 cm in length) would appear to preclude entities such as neointimal fibrous hyperplasia and may point to another consequence of intimal injury and full wall graft healing which may be an undesirable effect of arteriosclerotic metabolism in the human. It is conceivable that full wall graft healing in an arteriosclerotic individual may have untoward events that need to be further investigated as new graft materials are developed.

Adult↗