sodium-pertechnetate-tc-99m and Necrosis

The non-invasive imaging and quantification of L-type calcium channels (also known as dihydropyridine channels) in living tissues is of great interest in diagnosis of congestive heart failure, myocardial hypertrophy, irritable bowel syndrome etc.. Technetium-99m labeled amlodipine conjugate ([99mTc]-DTPA-AMLO) was prepared starting freshly eluted (<1 h) 99mTechnetium pertechnetate (86.5 MBq) and conjugated DTPAAMLO at pH 5 in 30 min at room temperature in high radiochemical purity (>99%, RTLC; specific activity: 55-60 GBq/mmol). The calcium channel blockade activity (CCBA) and apoptosis/necrosis assay of DTPA-amlodipine conjugate evaluations were performed for the conjugate. Log P, stability, bio-distribution and imaging studies were performed for the tracer followed by biodistribution studies as well as imaging.. The conjugate demonstrated low toxicity on MCF-7 cells and CCBA (at µm level) compared to the amlodipine. The tracer was stable up to 4 h in final production and presence of human serum and log P (-0.49) was consistent with a water soluble complex. The tracer was excreted through kidneys and liver as expected for dihydropyridines; excluding excretory organs, calcium channel rich smooth muscle cells; including colon, intestine and lungs which demonstrated significant uptake. SPECT images supported the bio-distribution data up to 4 h.. significant uptake of [99mTc]-DTPA-AMLO was obtained in calcium channel rich organs. The complex can be a candidate for further SPECT imaging for L-type calcium channels.

Topics: Amlodipine; Animals; Apoptosis; Calcium Channel Blockers; Calcium Channels, L-Type; Chromatography, Thin Layer; Molecular Structure; Necrosis; Radiopharmaceuticals; Rats; Sodium Pertechnetate Tc 99m; Solvents; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

To verify the effectiveness of percutaneous ethanol injection (PEI) in the treatment of large (>30-mL) hyperfunctioning thyroid nodules.. Twelve patients (eight women, four men; age range, 26-76 years) with a large hyperfunctioning thyroid nodule (volume range, 33-90 mL; mean, 46.08 mL) underwent PEI treatment under ultrasonographic (US) guidance. US was used to calculate the volume of the nodules and to assess the diffusion of the ethanol in the lesions during the procedure. When incomplete necrosis of the nodule was depicted at scintigraphy performed 3 months after treatment, additional PEI sessions were performed.. Four to 11 PEI sessions (mean, seven) were performed in each patient, with an injection of 3-14 mL of 99.8% ethanol per session (total amount of ethanol per patient, 30-108 mL; mean, 48.5 mL). At scintigraphy after treatment in all patients, recovery of extranodular uptake, absence of uptake in the nodule, and normalization of thyroid-stimulating hormone (thyrotropin) levels were observed. In all patients, US showed volume reductions of 30%-50% after 3 months and 40%-80% after 6-9 months. Side effects were self-limiting in all patients. During the 6-48-month follow-up, no recurrence was observed.. PEI is an effective and safe technique for the treatment of large hyperfunctioning thyroid nodules.

Topics: Adult; Aged; Aged, 80 and over; Ethanol; Female; Follow-Up Studies; Humans; Hyperthyroidism; Injections, Intralesional; Male; Middle Aged; Necrosis; Retreatment; Sodium Pertechnetate Tc 99m; Thyroid Nodule; Ultrasonography

In an experimental study on the epigastric venous system of rats, we examined three types of venous flaps with regard to their perfusion and long-term results: arterialised venous flaps, flow-through venous flaps and venous island flaps. We documented afferent and efferent blood flow with radiolabelled substances and blood distribution with infrared thermography. By measuring the surviving flap surfaces after 4 months, the relative success rate for each flap type was determined. The results show that in the chosen model the entire surface of the arterialised venous flap had a survival rate of 92.7%, the flow-through venous flap 62.4%, and the venous island flap about 31%. The venous island flaps had the worst distribution of intravenously injected 125J-Fibrinogen, and it was significantly worse in all types of venous flaps than in standard epigastric flaps; moreover, the clearance of intracutaneously injected 99mTc was the lowest in venous island flaps. The infrared thermographic study showed that the blood in the arterialised venous flaps dispersed faster and over a larger area than in flow-through venous and island flaps. Given these results, we conclude that arterialised venous flaps are the safest form of venous flaps, whereas venous island flaps carry a high risk of partial or total necrosis.

Topics: Animals; Fibrinogen; Graft Survival; Male; Necrosis; Postoperative Period; Rats; Rats, Wistar; Regional Blood Flow; Skin; Sodium Pertechnetate Tc 99m; Surgical Flaps; Thermography

Topics: Aged; Antibodies, Monoclonal; Evaluation Studies as Topic; Female; Gated Blood-Pool Imaging; Humans; Myocardial Infarction; Myocardium; Myosins; Necrosis; Sodium Pertechnetate Tc 99m

In 15 patients with a recent ischaemic cerebral vascular accident computerized tomography (CT) of the brain was normal whereas scintigraphy, performed at the same time, clearly showed the ischaemic area. These discordant findings may be interpreted as false-negative CT results. Factors such as the time elapsed between the cerebral accident and the CT examination, and the use or non-use of an intravenous contrast injection are discussed. It seems that the key factor is the proximity of the ischaemic lesion to the surface of the brain: cortical necrosis is undetectable at CT but distinctly visible at scintigraphy.

Topics: Adult; Aged; Aged, 80 and over; Brain Ischemia; Female; Humans; Male; Middle Aged; Necrosis; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Tomography, X-Ray Computed

Rats were irradiated laterally through the brain with 200 MeV protons. The beam was of circular cross-section with a diameter of 5 or 7 mm. The doses were 50, 70, 100 and 150 Gy. After irradiation the rats were examined several times by use of injected 99Tcm-pertechnetate. The uptake of the substance increased to a maximum after 20 to 30 days and then decreased to a normal level. Differences in maximum uptake with respect to dose were significant only for the smaller beam diameter.

Topics: Animals; Blood-Brain Barrier; Brain; Female; Hemorrhage; Necrosis; Permeability; Protons; Radiation Dosage; Rats; Rats, Inbred Strains; Sodium Pertechnetate Tc 99m; Technetium; Time Factors