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Abstract

Objective—To evaluate scintigraphy, radiography, and histomorphometric analysis for assessing incorporation of intercalary bone grafts and to compare incorporation of cortical autografts and allografts by the recipient.

Animals—12 skeletally mature sheep.

Procedures—A 5-cm tibial defect was filled with a cortical allograft (n = 6) or autograft (6) and stabilized with an interlocking nail. Radiography, scintigraphy, and fluorochrome bone labeling were performed every 3 months for 24 months. Radiographic evaluation included grading of the host and graft union and assessment of implants and grafts. Technetium-99m-hydroxymethylene diphosphonate radionuclide uptake was measured. Sheep were euthanatized 24 months after surgery, and bone formation was evaluated via histomorphometric analysis of fluorochrome labeling.

Results—Complete union was detected on radiographs by 21 months in all sheep but developed earlier in sheep that received an autograft versus in those that received an allograft. Radionuclide uptake peaked at 3 months and returned to presurgical values at 12 months. Histomorphometric analysis revealed fluorochrome labeling corresponding to each time point, with most bone formation at 9 through 15 months. Scintigraphy findings did not correlate well with fluorochrome labeling of newly formed bone.

Conclusions and Clinical Relevance—Although bone production around cortical bone grafts was detected by use of scintigraphy, this method did not provide accurate assessment of graft incorporation in sheep. Furthermore, bone produced by activated periosteum could not be distinguished scintgraphically from bone that replaced the graft. Intercalary autografts healed more rapidly and had greater incorporation into the host bone, compared with findings for allografts.

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in American Journal of Veterinary Research

, such as tumefactive autoimmune inflammatory demyelinating lesions, multiple sclerosis (because of acute demyelination), 27,28,43 viral diseases (because of glial activation), 19,20,44 and tumors (because of membrane turnover). 30 High concentrations

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in American Journal of Veterinary Research

Historically, the high-energy 511-keV annihilation photons produced by the positron emission decay of 18 F-NaF could not be adequately imaged with standard Anger-type gamma cameras and required rectilinear scanners equipped with thick thallium–activated sodium

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in American Journal of Veterinary Research

and early detection of overhydration during fluid administration. When fluid volume in the body of an animal is high, various physiologic mechanisms are activated to induce fluid loss, such as urination via kidneys, breathing and sweating via the

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in American Journal of Veterinary Research

-to-left atrial ejection time ratio indicating improved systolic function. 15,20,26,27 Similarly, time from P wave to peak A wave, acceleration time of the A wave, and A wave acceleration rate have been used to characterize atrial electromechanical activation in

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in American Journal of Veterinary Research

, evaluation of renal oxygenation independent of renal blood flow is necessary for assessment of kidney disease. Various methods can be used to evaluate renal oxygenation, including oxygen-sensitive microelectrodes, detection of activated hypoxia

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in American Journal of Veterinary Research

of contrast agent (0.04 mL/kg) followed by injection of saline (0.9% NaCl) solution (3 mL). A timer was activated when injection of the contrast agent began. For dogs with 1 adrenal gland lesion, a 2-injection procedure was used; for dogs with

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in American Journal of Veterinary Research

the heart is explained by an intimate interaction of muscle length and myofilament calcium activation . J Am Coll Cardiol 1987 ; 10 : 1157 – 1164 . 10.1016/S0735-1097(87)80361-3 18. Han JK , Kim AY , Lee KY , et al. Factors influencing

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in American Journal of Veterinary Research

activating the airway dilators while inhibiting the electrical activity in the diaphragm, as has been detected by electromyography. 3 Therefore, negative airway pressure alone does not cause pharyngeal collapse. 19 However, upper airway patency decreases

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in American Journal of Veterinary Research

physical examination, measurement of systemic arterial blood pressure, a CBC, serum biochemical and electrolyte analyses, urinalysis, and abdominal radiography and ultrasonography. Activated partial thromboplastin time a and prothrombin time a were also

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in American Journal of Veterinary Research