technetium-tc-99m-medronate and Disease-Models--Animal

Tc-99m methylene diphosphonate ([. Static whole-body single-photon emission computed tomography/computed tomography (CT) scans were acquired at 2 h post-injection of [. mdx mice had higher [. Higher uptake of [

Topics: Animals; Disease Models, Animal; Male; Mice; Mice, Inbred C57BL; Mice, Inbred mdx; Muscles; Muscular Dystrophies; Radiopharmaceuticals; Single Photon Emission Computed Tomography Computed Tomography; Technetium Tc 99m Medronate; Whole Body Imaging

To validate 99mTc-labeled arginylglycylaspartic acid (99mTc-3PRGD2) scintigraphy as a means to image synovial neoangiogenesis in joints afflicted by rheumatoid arthritis and to investigate its potential in the early detection and management of rheumatoid arthritis.. Rheumatoid arthritis and osteoarthritis were generated in Sprague Dawley rats by type II collagen immunization and papain injection, respectively. Rats were imaged with 99mTc-3PRGD2 and 99mTc- methyl diphosphonate (99mTc MDP). X-ray images were also obtained and assessed by a radiologist. Immunohistochemistry of αvβ3 and CD31confirmed the onset of synovial neoangiogenesis. The effect of bevacizumab on rheumatoid arthritis was followed with 99mTc-3PRGD2 scintigraphy. A patient with rheumatoid arthritis and a healthy volunteer were scanned with 99mTc-3PRGD2.. Two weeks after immunization, a significant increase in 99mTc-3PRGD2 was observed in the joints of the rheumatoid arthritis model though uptake in osteoarthritis model and untreated controls was low. 99mTc-MDP whole body scans failed to distinguish early rheumatoid arthritis joints from healthy controls. The expression of αvβ3 and CD31was significantly higher in the joints of rheumatoid arthritis rats compared to normal controls. In serial 99mTc-3PRGD2 scintigraphy studies, 99mTc-3PRGD2 uptake increased in parallel with disease progression. Bevacizumab anti-angiogenetic therapy both improved the symptoms of the rheumatoid arthritis rats and significantly decreased 99mTc-3PRGD2 uptake. Significantly higher 99mTc-3PRGD2 accumulation was also observed in rheumatoid arthritis joints in the patient.. Our findings indicate that 99mTc-3PRGD2 scintigraphy could detect early rheumatoid arthritis by imaging the associated synovial neoangiogenesis, and may be useful in disease management.

Topics: Animals; Arthritis, Rheumatoid; Bevacizumab; Collagen Type II; Disease Models, Animal; Early Diagnosis; Humans; Integrin alphaVbeta3; Male; Organotechnetium Compounds; Osteoarthritis; Papain; Peptides, Cyclic; Platelet Endothelial Cell Adhesion Molecule-1; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Technetium Tc 99m Medronate

The aim of this rat experiment using gamma correction pinhole bone scan (GCPBS) was two-fold: first, to confirm whether specific unwashed micro Tc-hydroxymethylene diphosphonate (Tc-HDP) uptake occurs in trabecular contusion (TC) and washed out uptake occurs in edema and/or hemorrhage-irritated trabeculae, and, second, to histopathologically identify the tissue in which the Tc-HDP uptake is unwashed. Five young Sprague-Dawley rats were used for the contusion model and one rat was used as a control. Trauma was inflicted on the femoral shaft with a free-falling iron ball. The presence of injury was confirmed by means of Tc-HDP pinhole bone scan and radiography with built-in scales. All rats were carefully killed for histopathologic verification. The size and shape of the unwashed high Tc-HDP uptake in TC were assessed on a 50-fold magnified GCPBS (mGCPBS), and the findings were compared with those of hematoxylin eosin (H&E) stain findings. mGCPBS showed TC with osteoblastic rimming and high unwashed Tc-HDP uptake. H&E stain findings showed osteoblastic rimming. The smallest TC was 0.03 mm in transaxial diameter on both mGCPBS and H&E stain findings. The four shapes of TC were bar-like, round, ovoid, and pinpointed in the longitudinal, oblique, and transaxial sections. The size and shape shown on mGCPBS and H&E stain findings were in good accord, demonstrating that TC was coated with osteoblastic rimming, which is pathognomonic of contusion. This sign was not seen for the control rat. mGCPBS is useful in the diagnosis of TC because osteoblastic rimming, typically stained in the base, is marked with unwashed high Tc-HDP uptake.

Topics: Animals; Cancellous Bone; Contusions; Disease Models, Animal; Fractures, Stress; Male; Radiography; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Technetium Tc 99m Medronate

Early diagnosis and therapeutic monitoring of acute osteomyelitis (AO) is challenging. Here, we use a polyethylene glycol (PEG)ylated chemotactic peptide cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF) conjugated with hydrazinonicotinamide (HYNIC) and labeled with Tc-99m ([(99m)Tc]cFLFLF) to image AO in a rat model and to validate its efficacy in early diagnosis and therapeutic evaluation of AO.. Forty rats were divided into eight groups of five each. Groups A, B, C, G, and H were AO models, and D, E, and F were sham controls. Groups A and D underwent [(99m)Tc]cFLFLF scintigraphy, groups B and E underwent [(99m)Tc]methylene diphosphonate ([(99m)Tc]MDP) bone scan, and groups C and F underwent 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) positron emission tomography (PET)/computed tomography (CT) scan. [(99m)Tc]cFLFLF biodistribution was assessed in group G. The response to antibiotic therapy was evaluated using [(99m)Tc]cFLFLF scintigraphy in group H. Conventional radiographs were obtained following scintigraphy. Ratios of infected or sham-operated tibia to the opposite tibia (T/B) were calculated. Immediately after the imaging studies, infected tibias were excised and underwent histopathological analysis and immunohistochemistry staining.. AO was present in all rats of groups A, B, C, G, and H. Total histological scores were not significantly different among groups A, B, and C (F = 0.34, p = 0.71). The biodistribution results revealed significant uptake and excellent retention of [(99m)Tc]cFLFLF in the infected tibia. [(99m)Tc]cFLFLF scintigraphy and [(99m)Tc]MDP bone scan both detected AO. The mean T/B ratio of [(99m)Tc]cFLFLF scintigraphy 1 h postinjection was 2.09-fold higher than that of [(99m)Tc]MDP bone scan (t = 13.81, p <0.001). The mean T/B ratio of [(18)F]FDG PET/CT scan was not significantly different from the control group F (t = 2.17, p = 0.062). [(99m)Tc]cFLFLF scintigraphy revealed a significant attenuation of inflammation in group H following a 3-week antibiotic treatment, which was verified by histopathological analysis and immunohistochemistry staining.. Our results suggest that the specificity and image quality of [(99m)Tc]cFLFLF are superior to those of the [(99m)Tc]MDP and [(18)F]DFG imaging probes currently used for early diagnosis of AO. Furthermore, [(99m)Tc]cFLFLF was able to effectively evaluate the therapeutic response to antibiotic treatment of AO. Our data suggest that [(99m)Tc]cFLFLF is a promising imaging agent for detection of infectious diseases.

Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Fluorodeoxyglucose F18; Humans; Immunohistochemistry; Inflammation; Male; Multimodal Imaging; Neutrophils; Oligopeptides; Organotechnetium Compounds; Osteomyelitis; Peptides; Positron-Emission Tomography; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Staphylococcus aureus; Technetium Tc 99m Medronate; Tibia; Tomography, X-Ray Computed

The aim of this study was to investigate the safety and efficacy of intravitreal injection of (99)Tc-MDP, a decay product of (99m)Tc-MDP, on the development of laser-induced choroidal neovascularization (CNV) in rhesus monkeys.. Experimental CNV was induced by argon laser with a small high-energy laser spot. Monkeys were given 50 μL of (99)Tc-MDP at a concentration of 0.005 μg/mL (n = 6) or 0.01 μg/mL (n = 6) by intravitreal injection once a week immediately after laser injury for a period of 56 days. Control animals were treated with the same volume of PBS (n = 6) in the same way. Eyes were monitored by ophthalmic examination, color fundus photography, fluorescence fundus angiography (FFA), optical coherence tomography (OCT) and histology. Incidences of grade 4 CNV lesions as well as the leakage areas of grade 4 CNVs on the late-phase of fluorescein angiograms were measured in a standardized, randomized and masked fashion fortnightly. The maximum widths and heights of grade 4 CNVs were also calculated by histology at the end of the experiment. Toxicity of (99)Tc-MDP on the retina was evaluated by electroretinogram (ERG) and histologic analysis.. (99)Tc-MDP reduced the incidences of grade 4 CNVs by 33.33 % and 39.40 % in the 0.005 μg/mL and 0.01 μg/mL groups, respectively, compared with the PBS group on day 28 (P < 0.05; n = 6). The leakage areas of grade 4 CNVs were smaller in the 0.005 μg/mL (0.7136 ± 0.0283 mm(2), p <0.01; n = 6) and 0.01 μg/mL (0.4351 ± 0.0349 mm(2), p < 0.01; n = 6) groups than those in the PBS control group (0.9373 ± 0.0455 mm(2); n = 6) in a dose-dependent manner on day 28. OCT and histology also showed that the sizes of CNVs were smaller in the (99)Tc-MDP treated groups than those in the PBS group. Although intravitreal injection of (99)Tc-MDP led to mild inflammatory reaction in the anterior chamber, histology and ERG findings demonstrated that (99)Tc-MDP did not cause any change in histological structure or function of the retina (p>0.05).. Intravitreal injection of (99)Tc-MDP can inhibit the development of laser-induced CNV without toxic effect on retina, suggesting that (99)Tc-MDP has therapeutic potential for CNV related diseases.

Topics: Animals; Capillary Permeability; Choroidal Neovascularization; Disease Models, Animal; Electroretinography; Female; Fluorescein Angiography; Intravitreal Injections; Laser Therapy; Lasers, Excimer; Macaca mulatta; Male; Radiopharmaceuticals; Technetium Tc 99m Medronate; Tomography, Optical Coherence

To investigate the effects of (99)Tc-MDP, a decay product of (99m)Tc-MDP, on the development of choroidal neovascularization (CNV), together with its underlying mechanisms.. C57BL/6J mice were used to induce CNV by laser photocoagulation. (99)Tc-MDP at the doses of 0.5 × 10(-1), 1 × 10(-1), and 2 × 10(-1) μg/kg or the same volume of PBS was intraperitoneally injected daily after photocoagulation until the end of the experiment. Seven days after laser injury, mice were perfused with fluorescein-labeled dextran, and areas of CNV were measured. Numbers of infiltrating macrophages, protein levels of VEGF, and inflammation-related molecules including intercellular adhesion molecule (ICAM)-1, tumor necrosis factor (TNF)-α, and matrix metalloproteinases (MMPs) in the RPE-choroid complex were detected 3 days after laser photocoagulation. Effects of (99)Tc-MDP on VEGF-induced endothelial cell migration and tube formation were also studied. Toxicity of (99)Tc-MDP was evaluated in vivo and in vitro.. Areas of CNV were significantly suppressed by (99)Tc-MDP treatment without toxicity to the retina compared with PBS treatment in a dose-dependent manner: (99)Tc-MDP treatment of 0.5 × 10(-1) μg/kg (5698.60 ± 1037.70 μm(2)), 1 × 10(-1) μg/kg (3678.34 ± 1328.18 μm(2)), and 2 × 10(-1) μg/kg (2365.78 ± 923.80 μm(2)) suppressed the development of CNV by 36.12%, 58.76%, and 73.48%, respectively, compared with that in the PBS treatment group (8920.36 ± 1097.29 μm(2); P < 0.001). (99)Tc-MDP treatment led to significant inhibition of macrophages infiltrating to CNV together with downregulated protein expressions of VEGF, ICAM-1, TNF-α, and MMP-2. (99)Tc-MDP also showed an inhibitive effect on cell proliferation and VEGF-induced migration and capillary-like tube formation of endothelial cells.. Anti-inflammatory treatment with (99)Tc-MDP has therapeutic potential for CNV-related diseases.

Topics: Animals; Anti-Inflammatory Agents; Cell Division; Cell Line; Cell Movement; Choroid; Choroidal Neovascularization; Disease Models, Animal; Electroretinography; Endothelial Cells; Gene Expression; In Vitro Techniques; Light Coagulation; Macaca mulatta; Macrophages; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase Inhibitors; Mice; Mice, Inbred C57BL; Radionuclide Imaging; Radiopharmaceuticals; Retina; Technetium Tc 99m Medronate; Vascular Endothelial Growth Factor A

Bone scan is the accepted initial imaging modality for skeletal metastases. Cisplatin is a cell-cycle nonspecific antineoplastic agent used in some chemotherapy regimens. Knowing that platinum reacts with phosphate compounds such as methylenediphosphonic acid (MDP), decreases bone resorption and new bone formation, it can be proposed that cisplatin chemotherapy may decrease Tc-99m MDP bone uptake. We aimed to demonstrate, if present, the decrease in bone uptake and to determine the duration of this effect.. Thirty male Wistar rats were randomized into five groups, namely, placebo group (G1) and cisplatin groups (G2, G3, G4, G5). Pre-therapy bone scintigraphies were obtained in all the groups. Cisplatin chemotherapy was given as infusion. Post-therapy bone scintigraphies were obtained 10 min, 1 h, 24 h, and 72 h after chemotherapy in groups G2-G5, respectively. A placebo bone scintigraphy was obtained 10 min after infusion of serum physiologic in G1. Plasma samples for cisplatin plasma values were obtained. The graphite furnace atomic absorption spectrophotometry technique was used for cisplatin analysis. Quantitative analysis (bone uptake ratios) was performed by drawing regions of interest on the right femur, vertebral column, and adjacent soft tissues. The injection/examination time delay and the net injected MDP doses were also noted.. There was no statistically significant difference in bone uptake values, injected MDP doses or injection/examination time delay in any group. Cisplatin plasma values were significantly different in G2, G3, G4, and G5 (P < 0.05) but not in G1.. Cisplatin chemotherapy seems to have no effect on the Tc-99m MDP uptake of normal bone.

Topics: Animals; Antineoplastic Agents; Bone and Bones; Cisplatin; Disease Models, Animal; Male; Metabolic Clearance Rate; Radionuclide Imaging; Radiopharmaceuticals; Rats; Rats, Wistar; Technetium Tc 99m Medronate

To establish a rabbit model of non-thermal high voltage electrical injury, which was accompanied by progressive tissue necrosis for the further study of electrical injury.. Seventy-five New Zealand rabbits were employed, in which 45 were used for the selection of the size of electrode plate, the inflicting time, the intervals and the injury degree. Five groups of rabbits were used for the study of the model. The study was carried out by means of clinical anatomical exploration, categorization by the Index of Deep Burn Injury (IDBI) and (99)Tc(m)-MDP isotope scanning and gamma photography.. The optimal injury indices selected were as follows: the electric field strength was 17 000 volts/m, the mean current intensity was 554 mA, and the average current density was 137 mA/cm(2) for small electrode and 21 mA/cm(2) for big one, and average increase of tissue temperature was 1.73 degrees C during injury process. This excluded the possibility of thermal injury. Five models were created, i.e. mild, moderate, severe, extra severe and destructive ones. There was no obvious cutaneous necrosis. Nevertheless, there was loss of injured extremities on 5th, 7th and 12th post-injury days in the severe, extra severe and destructive groups.. Non-thermal factor was the major cause of electric injury in the model with typical clinical features.

Topics: Animals; Burns, Electric; Disease Models, Animal; Rabbits; Radionuclide Imaging; Technetium Tc 99m Medronate

Systemic and topical administration of non-steroidal anti-inflammatory drugs (NSAIDs) has been shown to reduce periodontal disease progression in both animal models and human subjects. Our present research focuses on single enantiomers of these agents to examine whether enantiospecific therapy will be efficacious in slowing periodontitis. The purpose of this study was to evaluate the inhibitory effects of (S)-ketoprofen on experimentally induced alveolar bone loss in beagle dogs. 16, 18-month-old, female beagles were brought to optimal periodontal health over a 2-week pretreatment period. Experimental periodontitis was then induced by placing silk ligatures around premolar and molar teeth and by instituting a soft, plaque-promoting diet. At baseline, animals were randomized to 1 of 4 groups, consisting of 2x daily administration of (1) placebo dentifrice, (2) 0.3% (S)-ketoprofen dentifrice, (3) 3.0% (S)-ketoprofen dentifrice, or (4) 10.0 mg (S)-ketoprofen capsules (p.o.) over a 60 day treatment period. Standardized, periapical radiographs exposed at days 1 and 60 were analyzed by computer-assisted digital radiography in order to assess the rate of alveolar bone loss. Secondary outcomes included technetium 99m-tin-diphosphonate (99mTc-Sn-MDP) uptake and the gingival index. At baseline, no differences were observed among the groups for linear bone height or 99mTc-Sn-MDP uptake ratios. From days 1 to 60, cohorts differed significantly in terms of bone loss rates (p < 0.001). In particular, beagles treated with systemic or topical (S)-ketoprofen (0.3% or 3.0% dentifrices) exhibited significantly lower mean rates of bone loss compared to placebo treated beagles (p < 0.05). Group differences in mean radiopharmaceutical uptake ratio changes approached significance (ANOVA, p = 0.07), where animals treated with topical 0.3% (S)-ketoprofen demonstrated a reduction and other groups demonstrated elevations over the 60-day dosing period. Treatment cohorts did differ significantly with respect to changes in mean gingival indices (p < 0.05). Animals treated with 0.3% or 3.0% (S)-ketoprofen dentifrice exhibited significantly reduced elevations in gingival index scores as compared to placebo treated animals. These data provide evidence that enantiospecific therapy with (S)-ketoprofen, topically or systemically delivered, may alter the progression of periodontal disease in the beagle dog model.

Topics: Alveolar Bone Loss; Analysis of Variance; Animals; Anti-Inflammatory Agents, Non-Steroidal; Capsules; Cohort Studies; Dentifrices; Disease Models, Animal; Disease Progression; Dogs; Female; Follow-Up Studies; Humans; Image Processing, Computer-Assisted; Ketoprofen; Ligation; Periapical Tissue; Periodontal Index; Periodontitis; Placebos; Radiographic Image Enhancement; Radionuclide Imaging; Radiopharmaceuticals; Random Allocation; Stereoisomerism; Technetium Tc 99m Medronate; Treatment Outcome

To report the histopathological and bone scan characteristics of the stages of hydroxyapatite fibrovascular integration and to consider the implications for the timing of peg drilling in a primate model.. Three monkeys received hydroxyapatite implants covered only anteriorly with a fascia lata button to which the rectus muscles were sutured. Weekly bone scans were evaluated quantitatively and qualitatively. The orbits were harvested at 2, 4, and 8 weeks and examined histopathologically.. Quantitatively, the implant's technetium uptake increased, then reached a plateau by 4 weeks. Peripheral uptake was present on the images and histologically at 2 weeks. When bone scan images suggested complete vascularization by the fourth week, the implant was 99% vascularized histologically. Completion of vascularization was ascertained at 8 weeks, without further discernible changes in the bone scans.. The technetium bone scan is sensitive to the vascularization of the hydroxyapatite implant and discerns when complete vascularization is approached. This primate study models closely the clinical findings we have recently reported. We advocate at least a 4-week interval between the time the bone scan suggests full vascularization and peg drilling.

Topics: Animals; Biocompatible Materials; Disease Models, Animal; Durapatite; Eye, Artificial; Humans; Macaca fascicularis; Neovascularization, Physiologic; Orbit; Osseointegration; Prostheses and Implants; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Medronate

The objective of this work was to study in more detail the human/murine SCID arthritis model with special emphasis on characteristic features initiated by rheumatoid arthritis (RA) synovial membrane (SM) as compared to appropriate control tissues. Small tissue samples from RA-SM, healthy lymph node, healthy SM, and granulomatous tissue of human origin were implanted into the left knee joint of mice with severe combined immunodeficiency (SCID), and the joints were analysed histologically after 7 days. In addition, a time course study, including non-invasive monitoring by serological parameters (human IgM, IgG, and IL-6) and Tc-99m-scintigraphy, was performed for up to 4 weeks on RA-SM recipients. All tissue implants induced transient exudative joint inflammation while RA-SM initiated a characteristic arthritis with pannus tissue of high cellular density, erosion, multinuclear giant cells, lining cell hyperplasia, fibroblast-like cell layers, chondroideal metaplasia, and fibrin deposits. Significantly elevated levels of human immunoglobulin and characteristic signs of chronic inflammation persisted for more than 4 weeks. We conclude that the hu/mu SCID arthritis with RA-SM implants comprises features of non-specific inflammation which is also transiently seen with control tissues but develops characteristic features of chronic RA-like synovitis thereafter.

Topics: Animals; Arthritis, Rheumatoid; Disease Models, Animal; Granuloma; Humans; Immunoglobulin G; Immunoglobulin M; Immunohistochemistry; Inflammation; Interleukin-6; Knee Joint; Lymph Nodes; Mice; Mice, SCID; Radionuclide Imaging; Synovial Membrane; Technetium Tc 99m Medronate; Time Factors; Transplantation Chimera

The objective of this study was to correlate the levels of 2 putative markers of bone metabolism, namely osteocalcin and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), to the progression of experimental alveolar bone loss in the beagle dog. 36 control sites and 36 experimental sites in 2 beagle dogs were assessed longitudinally at 2-week intervals for gingival crevicular fluid (GCF) osteocalcin and ICTP levels during a 6-month observation period. Analysis of osteocalcin and ICTP in GCF was performed by RIA. During the study, bone-seeking radiopharmaceutical uptake (BSRU) of 99mTc-MDP was assessed monthly; standardized radiographs were taken at 2-week intervals. The results showed osteocalcin and ICTP levels in GCF increased significantly (p < 0.05) by 2 weeks following initiation of disease. This increase preceded significant increases in BSRU by 2 weeks and radiographic evidence of bone loss by 4 weeks. BSRU was significantly elevated (p < 0.05) at experimental sites as compared to controls at 4 and 8 weeks post-disease initiation. Osteocalcin in GCF peaked 8 and 10 weeks after ligature placement in experimental sites at levels nearly 10-fold greater than contralateral paired control sites. ICTP levels in GCF remained elevated throughout the entire disease progression phase. Following the removal of ligatures, both GCF osteocalcin and ICTP levels dropped precipitously approaching control values. Osteocalcin revealed overall a positive predictive value (PPV) and negative predictive value (NPV) for future bone loss during disease progression of 0.87 and 0.34, respectively, while ICTP showed both high PPV and NPV of 0.87 and 0.91 respectively. Results from this study in the dog model indicate that osteocalcin and especially ICTP relate to indices of active periodontal bony destruction and suggest that these molecules may serve as predictive markers for future alveolar bone loss.

Topics: Alveolar Bone Loss; Alveolar Process; Animals; Biomarkers; Collagen; Collagen Type I; Disease Models, Animal; Disease Progression; Dogs; Forecasting; Gingival Crevicular Fluid; Longitudinal Studies; Male; Osteocalcin; Peptides; Periodontitis; Pilot Projects; Predictive Value of Tests; Radiography; Sensitivity and Specificity; Technetium Tc 99m Medronate

The 24-h whole-body retention (24-h WBR) of 47Ca-chloride and 99mTc-MDP was measured in four rat models over a 6-week period at 2 week intervals. Fine detail bone radiographs of the femurs and histologic bone specimens were also obtained simultaneously. In the osteomalacic (M) and steroid-induced osteoporotic (S) groups the 24-h WBR values of 47Ca were significantly lower, and in the osteoporotic (P) group were higher than in the control (C) group from the second week. The 24-h WBR values of 99mTc-MDP were significantly higher in the M group and were lower in the S group from the second week. Simultaneous measurements of 24-h WBR of these two radiopharmaceuticals facilitated the early differentiation of metabolic bone diseases in the animal models prior to the detection of radiologic bone changes.

Topics: Animals; Autoradiography; Bone and Bones; Bone Diseases, Metabolic; Calcium Chloride; Calcium Radioisotopes; Disease Models, Animal; Male; Radiography; Rats; Rats, Wistar; Scintillation Counting; Technetium Tc 99m Medronate

Thirty-two patients in whom Legg-Perthes disease apparently involved only one hip were examined with venography, measurement of intraosseous and intra-articular pressures, arthrography, and dynamic triphasic bone-imaging with 99mTc methylene diphosphonate. The arterial flow of blood in the affected femoral head was slightly decreased, but the difference from that on the normal side was not statistically significant. However, there was marked disturbance of the venous drainage in the diseased hip, elevated intraosseous pressure in the affected femoral neck, and increased intra-articular pressure in the involved hip compared with the normal side. An animal model was then created in twenty immature dogs, venous drainage was obstructed, and intraosseous pressure of the femoral head and neck was elevated by injection of four milliliters of semiliquid silicone into the femoral neck. In eleven of the dogs, areas of avascular necrosis resembling those associated with Legg-Perthes disease developed in the femoral head.

Topics: Adolescent; Animals; Arthrography; Child; Child, Preschool; Disease Models, Animal; Dogs; Female; Femur Head; Femur Neck; Hip Joint; Humans; Legg-Calve-Perthes Disease; Male; Osteonecrosis; Phlebography; Pressure; Radionuclide Imaging; Technetium Tc 99m Medronate; Venous Pressure

We studied the occurrence, magnitude, and kinetics of bacteremia and the resultant osteomyelitis and septic arthritis in an avian model of Staphylococcus aureus infection. Thirty-day-old male broiler chicks were inoculated i.v. with 10(5), 10(6), or 10(7) cfu of strain Duntravis, a beta-hemolytic, coagulase-producing, capsular type 8 isolate from the synovial fluid of a 2-year-old black boy. Bacteremia occurred in 80%, 90%, and 100% of animals inoculated with 10(5), 10(6), or 10(7) cfu, respectively. The magnitude of bacteremia in surviving, bacteremic animals increased for 96 hours after inoculation and then decreased after a plateau phase. Osteomyelitis and septic arthritis occurred only in chicks that were continuously bacteremic. The occurrence of osteomyelitis was uniform among continuously bacteremic animals and developed 1 to 23 hours after inoculation. Chickens are susceptible to systemic infections with S. aureus. Bacteremia, osteomyelitis, and septic arthritis may be induced in healthy chickens without prior manipulations that depress their resistance.

Topics: Animals; Bone and Bones; Chickens; Disease Models, Animal; Male; Osteomyelitis; Radiography; Radionuclide Imaging; Sepsis; Staphylococcal Infections; Technetium Tc 99m Medronate; Time Factors

Topics: Animals; Disease Models, Animal; Dogs; Jaw; Jaw Diseases; Lasers; Osteoradionecrosis; Radiation Injuries; Radiation Injuries, Experimental; Radionuclide Imaging; Technetium Tc 99m Medronate; Time Factors; Ultrasonography

This study evaluates the effect of hydrocortisone on the sensitivity of 99mTc-scintigraphy for the detection of bone trauma in three groups of rabbits: a control group that received no hydrocortisone, a low-dose group that received 0.8 mg/kg/day, and a high-dose group that received 20 mg/kg/day. Scintigrams of the tibial diaphyses were obtained at 48 hr, 1 week, 2 weeks, and 3 weeks after surgical creation of a simulated fracture (a 1.5-mm hole in the cortex). The mean sensitivity for detecting fractures in control animals was 95% at 48 hr and 100% at all other times. Mean sensitivity for rabbits given the high dose of hydrocortisone was 41% at 48 hr. Mean sensitivity for the low-dose group was 75% at 48 hr, but this was not significantly different from the control group. Sensitivity in both groups treated with hydrocortisone improved with time. At 3 weeks, the mean was 93% in the low-dose group and 83% in the high-dose group. These data suggest that 99mTc scintigraphy may be less sensitive in detecting bone trauma in patients on glucocorticoid therapy than in patients in the general population.

Topics: Animals; Diagnostic Errors; Disease Models, Animal; Drug Interactions; Fractures, Bone; Hydrocortisone; Rabbits; Radionuclide Imaging; Statistics as Topic; Technetium Tc 99m Medronate

A noninvasive radionuclide technique to visualize ischemic small intestine was evaluated. Vascular ligation of 20-30 cm ileum was done in rabbits. After induction of ischemia, technetium (99mTc) methylene diphosphonate (TMDP) was injected IV at intervals up to 24 hours. Images were recorded 1 and 3 hours after injection of radioisotope and showed preferential (9:1) uptake by ischemic bowel. Positive scans were present in all animals up to 4 hours and in 75% at 10-12 hours, but in none 24 hours after induction of ischemia. Nonocclusive intestinal ischemia was simulated in 4 dogs by infusing norepinephrine into a jejunal mesenteric arterial branch. After 1 hour, an IV bolus of TMDP was injected and images recorded at intervals up to 3 hours. Selective uptake of isotope by the ischemic segment was observed in all animals. Angiography confirmed that isotope uptake was confined to the infused segment. These studies show that occlusive intestinal ischemia can be detected, by radionuclide imaging up to 12 hours, and nonocclusive (low flow) ischemia for at least 4 hours, after onset.

Topics: Acute Disease; Animals; Arterial Occlusive Diseases; Disease Models, Animal; Dogs; Evaluation Studies as Topic; Ileum; Ischemia; Jejunum; Rabbits; Radionuclide Imaging; Technetium Tc 99m Medronate; Time Factors

The present study was undertaken to investigate the sites at which the 99mTc phosphorous compounds bind to skeletal tissue in general, and their localization at different stages of osteoarthritis in particular, in order thereby to arrive at a better morphological basis for interpreting the scintigrams. It was endeavoured also to relate the uptake of bone-seeking agents to abnormal changes in cartilage, synovium, and subchondral bone to obtain better insight into the pathogenesis of osteoarthritis. The bone remodelling activities in subchondral bone in osteoarthritic human femoral heads were elucidated by the alkaline phosphatase activity of osteoblasts and the acid phosphatase activity of osteoclasts. The enzyme activity was measured semiquantitatively by the initial time for the histochemical reaction. The distribution of the activity of the two enzymes in different areas proved parallel, and considerable variation in enzyme activity was seen between different areas within the same femoral head. Increased osteoarthritic cartilaginous changes were associated with increased subchondral enzyme activity, highest in denuded weightbearing areas and in the osteophytes and lowest in non-weightbearing subchondral bone and centrally in the femoral head. Studies on different histochemical staining of glycosaminoglycans in the matrix of human osteoarthritic cartilage and of normal cartilage revealed a heterogeneous distribution of the different glycosaminoglycans through the cartilage. Except for superficial loss of glycosaminoglycans, no difference was found in the distribution of keratan sulphate between osteoarthritic cartilage and control cartilage. In osteoarthritis, however, a relative increase in stainability for chondroitin sulphate was found in the territorial area, especially around the cell clusters, and only chondroitin sulphate was present in the cartilage of osteophytes. These findings were interpreted as an increased GAG metabolism, its mode of production being like that of very young cartilage. In the experimental rabbit model used in studying the uptake of bone-seeking agents this GAG regeneration was able to refill demasked collagen network with glycosaminoglycans in certain areas of the joint. The height of the depleted superficial area was estimated on patellar cartilage stained for sulphated GAG with toluidine blue-0 at pH 3, visually and by optical densitometry using the wavelength corresponding to the gamma-band of toluidine blue. The time rel

Topics: Alkaline Phosphatase; Animals; Autoradiography; Bone and Bones; Cartilage; Collagen; Diphosphonates; Disease Models, Animal; Dogs; Femur Head; Glycosaminoglycans; Humans; Knee; Knee Joint; Osteoarthritis; Proteoglycans; Rabbits; Radionuclide Imaging; Rats; Synovial Fluid; Synovial Membrane; Technetium; Technetium Tc 99m Medronate

Topics: Animals; Diagnosis, Differential; Diphosphonates; Disease Models, Animal; Dogs; Female; Femur; Gallium Radioisotopes; Hip Prosthesis; Indium; Leukocytes; Male; Postoperative Complications; Quality Control; Radioisotopes; Radionuclide Imaging; Staphylococcal Infections; Technetium; Technetium Tc 99m Medronate; Tissue Distribution