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Technetium-99m pyrophosphate in diagnosis of acute cardiac rejection in the rat with effect of cyclosporine: concise communication.

Tc-99m pyrophosphate (PPi) uptake has been measured in a rat model of heterotopic heart transplant at 5 days after transplantation. comparison of tracer uptake, as a ratio between the heterotopic transplanted heart and the recipient's native heart, was made in four groups of animals. Group 1, with transplants between animals of isogeneic strain showed a lower ratio, significantly different from the ratio in Group 2 in which transplants were between nonisogeneic animals. The ratio of uptake after transplantation between nonisogeneic animals treated with 10 mg/kg-day of cyclosporine (Group 3), was not significantly different from Group 1. In contrast, the ratio of uptake between nonisogeneic animals treated with subtherapeutic doses of cyclosporine (Group 4), was not significantly different from Group 2. In Groups 1, 2, and 3 there was a correlation between the histology of the transplanted hearts, graded 1 to 5 according to the severity of rejection, compared with the uptake of Tc-99m PPi. This agent can therefore be used to diagnose cardiac rejection in a rat model, and the results correlate well with the severity of rejection as assessed histologically.

Animals↗

[Comparative studies on 99mTc-pyrophosphate and 85Sr-chloride for skeletal imaging].

In order to know the potential merits of 99mTc-pyrophosphate (99mTc-PYP) skeletal imaging, a comparative study was carried out by administering to the rabbit 85Sr-chloride (85Sr), classical bone-seeking agent, and 99mTc-PY simultaneously. Radioisotopic distribution was investigated as regards their deposition in the pelvic bones, and sharpness of the skeletal scintigrams, too. Both agents were remarkably affinitive to the skeletal system and there were remarkably differences in their temporal deposition pattern. Marked deposition was observed of either agent in the metaphyses. With 99mTc-PYP, the vertebral and costal systems were delineated symmetrically and each vertebral body was distinctly depicted as such 99mTc-PYP many possess the following merits over 85Sr; (1) owing to its physical properties, sufficiently large radioactivity of 99mTc-can be administered; (2) body burden of radiation absorption is reduced; (3) skeletal scintigrams of high quality are obtainable in a short period of time.

Animals↗

The pyrophosphate heart scintigram in children with progressive muscular dystrophy.

A pyrophosphate heart scintigram was obtained in 16 boys with progressive muscular dystrophy Duchenne. All of them showed pathological ECG findings and high plasma levels of CK, AST, ALT and LD. In 4 patients the scintigram was distinctly positive and in further 3 it reached borderline values. The remaining 9 boys had normal scintigraphic findings. Those with a positive heart scintigram had very high plasma levels of the enzymes under study which was suggestive of current progression of the disease. There was, however, no relation between heart scintigraphy and the affliction of the skeletal muscles expressed by means of an index.

Adolescent↗

[Indicators of scintigraphy using technetium Tc 99m pyrophosphate in angina pectoris in relation to the activity of the pituitary-adrenal system].

The effect of exercise on the parameters of the scintigraphy of the myocardium with labelled pyrophosphate was studied in 35 patients with coronary heart disease and angina of effort and at rest with regard to the activity of the pituitary-adrenal cortex system. The functional status of this system was evaluated on the basis of data on the blood changes in somatotrophic hormone and cortisol. The use of a scoring system made it possible to identify four types of the pattern of the scintigraphic parameters. Type I and II of the pattern of the scintigraphic parameters indicating the normal ratios between the requirements of the cardiac muscle in oxygen and myocardial perfusion were characteristic of the patients with angina pectoris in the presence of an increased activity of the pituitary-adrenal cortex system. When the coronary heart disease patients with angina had a lower activity of this system, the authors more frequently recorded types III and IV of the pattern of scintigraphy which reflected a decreased perfusion and myocardial damage during exercise.

Adult↗

The tophus in calcium pyrophosphate deposition disease.

A 61-year-old man had a tophus on the third finger of his right hand. There was no history of arthritis, no laboratory abnormality, and no chondrocalcinosis. Crystalline material from the tophus was identified as calcium pyrophosphate dihydrate by x-ray diffraction.

Calcium Pyrophosphate↗

Effect on dental caries of a stannous fluoride-calcium pyrophosphate dentrifice in an adult population: one-year results.

The first year of a two-year double-blind clinical trial of the anticaries effectiveness of a stannous fluoride-calcium pyrophosphate (SnF2-CPP) dentifrice as compared to a placebo control dentifrice involved 1,337 adult subjects, 18 to 78 years of age. Adult subjects were examined for dental caries at a baseline examination and after one year of ad lib dentifrice usage by an experienced clinical examiner using a visual-tactile examination and a radiographic evaluation. Results of the study after one year indicate a significant (P < 0.05) 33.3% difference in new caries formation with use of the SnF2-CPP dentifrice as compared to the placebo control based on the DMFS score.

Adolescent↗

Tc-99m pyrophosphate myocardial imaging in perimyocarditis.

A focal or diffuse pattern of Tc-99m pyrophosphate (Tc-99m PPi) myocardial uptake may occur in patients with acute myocardial necrosis from various causes. A recent study has shown intense Tc-99m PPi myocardial uptake in experimental viral perimyocarditis in mice. This report describes a patient with perimyocarditis, with intense, persistent, and generalized myocardial uptake of Tc99m PPi.

Diphosphates↗

Effect of vitamin D3, other drugs altering serum calcium or phosphorus concentrations, and desoxycorticosterone on the distribution of Tc-99m pyrophosphate between target and nontarget tissues.

Radioactive imaging agents are chemically designed for selective distribution. Another approach to selectivity is to find stable compounds that favorably influence this distribution. Using a rat model of myocardial necrosis, we studied effects of various stable compounds (as a single, large dose or fractionated into short series) on the ratio, uptake of Tc-99m pyrophosphate (PPi) by the target lesion/uptake by the principal nontarget, bone (L/B). Vitamin D3s ability to increase L/B was mediated by the hypercalcemia and hyperphosphatemia that it caused. The hypercalcemia was accompanied by increased [Ca] in the lesion. In contrast, pulse doses of desoxycorticosterone acetate (DOCA) at 7 and 6 hr before killing increased uptake by lesion, increasing L/B from 0.19 +/- 0.03 to 0.45 +/- 0.08 (p less than 0.01), with no change in serum [Ca] and minimal changes in serum [P], [Na], and [K]. DOCA also increased the lesion-to-blood ratio from 6.5 +/- 0.07 to 15.4 +/- 3.9 (p less than 0.05). These results encourage further study of DOCA's effect and investigation of other stable drugs that may influence distribution of other imaging agents.

Animals↗

[Scintigraphic diagnosis of experimentally induced pericarditis in dogs using 99mTc-labelled pyrophosphate (author's transl)].

In the present paper the possibilities of scintigraphic diagnosis of experimental pericarditis are discussed. Pericarditis was induced by either talc or formaldehyde intrapericardially. In all animals the administration of talc as well as formaldehyde produced inflammatory changes which were more serious after formaldehyde. The scan of the talc pericarditis was carried out on the 7th day after operation and of the formaldehyde pericarditis on the 3rd, 7th or 14th days. No positive scintigraphic finding was made in any of the experimental animals, apart from a massive incorporation in the operation scars. The counting of radioactive impulses after the exstirpation of the tissue samples confirmed the scintigraphic findings. Statistical evaluation did not reveal any essential difference between the accumulation of the radiopharmaceutical into the pericarditis as well as into the pericardial bag in comparison with the control animals. Although our model does not exactly reflect the situation of patients suffering from pericarditis it may be assumed that pyrophosphate scintigraphy is not suitable for the diagnosis of acute pericarditis in clinical practice.

Animals↗

Decomposition of Tc-99m pyrophosphate by peroxides in pertechnetate used in preparation.

We describe an investigation of the stability of Tc-99m pyrophosphate (Tc-99m PPi). We hve shown that addition of exogenous hydrogen peroxide to Tc-99m PPi can initiate the oxidation of the complex, giving rise to 95% unbound pertechnetate. The presence of endogenous hydrogen peroxide in the sodium pertechnetate used in the preparation of Tc-99m PPi has been thought to influence its stability. We have prepared it using pertechnetate solutions of different specific activities. After preparation, an alumina column was used to detect free 99mTcO4-. The Tc-99m PPi and Na99mTcO4 solutions were then assayed by iodometric titration for hydrogen peroxide, which was detected in the pertechnetate solutions. The higher the specific activity of the solution used for the tracer preparation, the faster was the production of free pertechnetate.

Diphosphates↗

The diagnosis of renal osteodystrophy: a comparison of Technetium-99m-pyrophosphate bone scintigraphy with other techniques.

In order to determine the place of Technetium-99m-pyrophosphate bone scintigraphy in the assessment of renal osteodystrophy, 17 patients with chronic renal failure requiring hemodialysis underwent bone scans and these were compared to results of biochemical, radiological and histologic studies. Bone histology was abnormal in all patients with most having evidence of osteomalacia and hyperparathyroid bone disease. Using semi-quantitative scan scores and regional bone-standard ratios, isotope uptake was increased in 16 patients, while 15 had elevated alkaline phosphatase levels and 7 had X-ray changes. An osteoid-osteoclast index combining histological osteomalacia and hyperparathyroid disease was derived and was found to correlate more closely with alkaline phosphatase and parathyroid hormone levels than with scan parameters. It was concluded that bone scans did not provide therapeutically useful information that could not be obtained from biochemical and radiological studies. It appeared that only bone histology could differentiate osteomalacia and hyperparathyroid bone disease.

Adult↗

[Sympathetic reflex dystrophy with hypofixation of technetium 99 m pyrophosphates on bone scintigraphy (author's transl)].

A patient with sympathetic reflex dystrophy following injury to the right foot presented fairly typical clinical and radiological signs, though the hot phase was particularly short. Bone scan with technetium 99 m pyrophosphates demonstrated hypofixation, which, though extremely rare, has been previously reported in the published literature. The fact that isotopic bone hypofixation can occur during sympathetic reflex dystrophy should be recognised, as far from constituting an argument against the early diagnosis of this affection, it should enable the organic nature of the disorder to be confirmed, and assist the physician in making an early diagnosis.

Adult↗

Calcium pyrophosphate dihydrate deposition disease and familial hypomagnesemia.

A 40-year-old woman presented with calcium pyrophosphate synovitis and chondrocalcinosis. She was subsequently found to have hypomagnesemia, as did her 22-year-old son. Metabolic studies demonstrated normal gastrointestinal absorption of magnesium, and impaired renal conservation of magnesium without other evidence of renal tubular dysfunction. It seems likely that a genetically determined abnormality of magnesium metabolism was responsible for the occurrence of chondrocalcinosis in this patient.

Adult↗

[Assessment of the results of aorto-coronary bypass surgery with the technetium 99m pyrophosphate scintigram (author's transl)].

In 40 patients with angiographically-documented coronary artery disease, technetium 99m pyrophosphate (99mTc-PYP) myocardial scintigrams were obtained prior to and four to six weeks after aorto-coronary bypass surgery. In the majority of patients, preoperative and postoperative exercise testing with simultaneous pulmonary artery pressure recordings was performed. In 22 of 30 patients with preoperatively increased 99mTc-PYP myocardial activity, no tracer accumulation could be found postoperatively. In the latter patients, there was also a significant increase in exercise capacity and lessening of ischemic ST-segment depression in the exercise ECG. In the remaining eight patients in whom increased tracer accumulation was found to persist postoperatively, there was no improvement in exercise capacity. In ten patients with no myocardial tracer accumulation preoperatively, unchanged myocardial scintigrams and a significant decrease of the ischemic ST-segment depression in the exercise ECG were seen postoperatively except in one patient with perioperative myocardial infarction. These results were also partially confirmed by repeated coronary angiography and ventriculography. Patent bypass grafts were associated with regional improvement in left ventricular function. The results indicate that postoperative absence of myocardial tracer accumulation appears due to amelioration of preexisting myocardial ischemia at rest. Thus, in the assessment of the results of aorto-coronary bypass surgery, the 99mTc-PYP scintigram offers an important diagnostic potential.

Coronary Artery Bypass↗

Cartilage matrix in hereditary pyrophosphate arthropathy.

Morphological and biochemical studies of articular cartilage were performed in 6 members of 3 families with hereditary pyrophosphate arthropathy. Evidence of metabolic disturbance of cartilage matrix was obtained from light and electron microscopic findings and by the content and composition of glycosaminoglycans.

Adult↗

Pyrophosphate scan of the temporarily ischemized dog myocardium.

In 9 dogs a transient myocardial ischemia was provoked using complete occlusion of the ramus interventricularis anterior of the left coronary artery. The occlusion was removed after 5, 10 or 15 min. Four hrs after removal of the occlusion a scan of the myocardium was carried out using 99mTc-labelled pyrophosphate. In 7 out of 9 dogs under study the scan was markedly positive, in 2 dogs negative. ECG demonstrated ischemic changes practically in all dogs; the changes became normal after removal of the occlusion, namely in 5 to 35 min. The histological examination of the tissue demonstrated in all 9 dogs only a slight impairment of the myocardium.

Animals↗

Predictive value of 99mTc pyrophosphate bone scintigraphy for vitamin D trials in uraemia.

The usefulness of 99mTc-Pyrophosphate (99mTc-PPi) bone scintigraphy was evaluated in the follow up of 21 haemodialysed patients without clinical or radiological evidence of osteodystrophy. 99mTc-PPi bone scintigraphy was semi-quantitatively analysed using Fogelman's score. Patients were randomised to receive vitamin D analogues (1 alpha hydroxyvitamin D3 or dihydrotachysterol, n = 12) or to serve as controls (n = 9), both groups being given oral calcium supplements. Bone scintigraphy deteriorated in patients only on calcium therapy but not in patients treated by vitamin D-analogues. Vitamin D therapy reduced secondary hyperparathyroidism in all cases but induced rapid intoxication with normal doses in 4 of the 12 treated patients. Since intoxicated patients had significantly lower Fogelman's score than the patients who tolerated the treatment well, 99mTc-PPi bone scintigraphy is proposed as a screening test before vitamin D-analogues trials.

Bone and Bones↗