RADIOISOTOPE DIAGNOSTIC ALGORITHM FOR THE RELAPSE AND METASTASES DETECTION IN THE IODINE-NEGATIVE DIFFERENTIATED THYROID CANCER. / RADIONUKLIDNYI DIAGNOSTYChNYI ALGORYTM DLIa VYIaVLENNIa RETsYDYVIV I METASTAZIV U KhVORYKh Z IOD-NEGATYVNYMY FORMAMY DYFERENTsIIOVANOGO RAKU ShchYTOPODIBNOÏ ZALOZY.

OBJECTIVE: Developing of algorithm for the post-surgical management of patients with iodine-negative metastasesof differentiated thyroid cancer (DTC). MATERIALS AND METHODS: The DTC patients with iodine-negative metastases (n = 115) were enrolled in the study.Of them the whole body scintigraphy (WBS) was performed with technetium-99m-hexakis-2-methoxyisobutylisonitrile(99mTc-MIBI) (n = 30), WBS with technetium-99m dimercaptosuccinic acid (99mTc-DMSA) (n = 30), 18FDG PET (n = 30), andcomputer tomography (CT-scan) (n = 25). Complex 99mTc-pertechnetate scans including the dynamic and static scintigraphy was performed supplementary to 99mTc-MIBI WBS in 10 patients to obtain the angiographic curves from DTCmetastatic foci. The non-radioiodine radiopharmaceutical technologies, namely the labeled 99mTc-MIBI, 99mTc-DMSA, 99mTc-pertechnetate, and 18FDG were applied to detect the iodine-negative DTC metastases. Radioisotopic examinationswere performed at the dual-head gamma camera (Mediso Medical Imaging Systems Ltd., Hungary) and single photonemission computed tomography (SPECT) scanner «E.CAM¼ (Siemens, Germany). PET/CT scans were performed on the«Biograph 64 TruePoint¼ imaging platform (Siemens, Germany) in accordance with the European Association of NuclearMedicine (EANM) recommendations for the Siemens imaging devices with 3D-mode data acquisition. RESULTS: The conducted research suggested that it is feasible to use the non-radioiodine (99mTc-MIBI and 99mTc-DMSA)radiopharmaceutical technologies to detect the iodine-negative DTC metastases. 18FDG PET is a highly informativetechnology for the detection of iodine-negative DTC metastases in case of lung involvement in the process. Compareof the non-radioiodine radiopharmaceuticals, CT scan and 18FDG-PET/CT indicated the highest sensitivity of 18FDGPET/CT (p < 0.05). WBS with 99mTc-MIBI and 99mTc-DMSA featured the highest specificity (100 %, p < 0.05). X-ray CTis marked by the significantly lower either sensitivity, specificity, and accuracy rate (p > 0.05). Developing andapplication of algorithm for the post-surgical management of patients with iodine-negative forms of DTC will allowfor the betimes detection of relapses and metastases with administration of adequate surgical, radiation, and targeted treatment. CONCLUSIONS: Obtained results offer the opportunity to optimize the post-surgical management of patients withiodine-negative DTC forms using the options of radionuclide diagnostics with non-radioiodine radiopharmaceuticals. The latter are readily available providing the cost-cutting of diagnostic support in these patients. Place ofmorphological methods of diagnosis is determined and stage of monitoring of patients with the iodine-negativemetastases is established. Possibility of the 18FDG-PET tests for the early diagnosis of iodine-negative metastases inDTC for the first time have been studied and substantiated in Ukraine. A comprehensive radiation algorithm for thelong-term monitoring of this category of patients will allow the timely detection of recurrences and metastases ofDTC and appropriate surgery, radiation and targeted therapy administration. Data obtained as a result of the studyallowed to improve the overall and recurrence-free survival rates in the able-bodied DTC patients and reduce thecosts of follow-up of patients with iodine-negative forms of DTC.

Radioprotective effect of Ocimum sanctum and amifostine on the salivary gland of rats after therapeutic radioiodine exposure.

The current study investigated the radioprotective effect of Ocimum sanctum on the salivary gland of rats administered radioiodine ((131)I) and compared its efficacy with a known radioprotectant, amifostine. The experimental rats were divided in four groups and sacrificed in three different batches at 1, 3, and 6 months of time interval after 18.5 MBq/100g (i.p.) (131)I exposure. Six months duration batch received (131)I exposure twice with the gap of 3 months. Two groups of experimental rats were presupplemented with O. sanctum (40 mg/kg for 5 days, orally) and amifostine (200 mg/kg, s.c) before (131)I exposure separately. Increased Technetium-99m-pertechnetate ((99m)TcO(4)(-)) uptake at 30 minutes post injection in salivary glands of only (131)I exposed rats may imply delay in clearance at 6 months of exposure in comparison to their counterparts sacrificed at 1 month. Parotid gland histology showed atrophy with lipomatosis in only (131)I exposed rats at 3 and 6 months of duration. O. sanctum and amifostine presupplemented and subsequently exposed to (131)I rats at 3 and 6 months duration exhibited comparable histopathology with controls. Our study indicates possible radioprotective effect of O. sanctum and amifostine against high-dose (131)I exposure.

An experimental model to study the effects of a senna extract on the blood constituent labeling and biodistribution of a radiopharmaceutical in rats.

Cassia angustifolia Vahl (senna) is a natural product that contains sennosides, which are active components that affect the intestinal tract and induce diarrhea. Authors have shown that senna produces DNA (deoxyribonucleic acid) lesions in Escherichia coli cultures and can act as an antifungal agent. Natural drugs can alter the labeling of blood constituents with technetium-99m (99mTc) and can affect the biodistribution of radiopharmaceuticals. In this work, we have evaluated the influence of a senna extract on the radiolabeling of blood constituents and on the biodistribution of the radiopharmaceutical sodium pertechnetate (Na99mTcO4)in Wistar rats. Twelve animals were treated with senna extract for 7 days. Blood samples were withdrawn from the animals and the radiolabeling procedure was carried out. The senna extract did not modify the radiolabeling of the blood constituents. A biodistributional assay was performed by administering Na99mTcO4 and determining its activity in different organs and in blood. The senna extract altered the biodistribution of Na99mTcO4 in the thyroid, liver, pancreas, lungs and blood. These results are associated with properties of the chemical substances present in the aqueous senna extract. Although these assays were performed in animals, our findings suggest that caution should be exercised when nuclear medicine examinations using Na99mTcO4 are conducted in patients who are using senna extract.

Effect of an extract of Aloe vera on the biodistribution of sodium pertechnetate (Na99mTcO4) in rats.

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.

Effect of Zusanli (ST.36) electroacupuncture at two frequencies on the bioavailability of (99m)Tc-sodium pertechnetate and on labeling of blood constituents in rats.

OBJECTIVES: A study was performed on the effects of stimulation at Zusanli-point (ST.36) by electroacupuncture (EA) at two frequencies on the bioavailability of (99m)Tc-sodium pertechnetate (Na(99m)TcO(4)) in rats. METHODS: Forty Wistar rats were divided into four groups: untreated control, treated by manual acupuncture at ST.36 bilaterally, treated by EA at 2 Hz at ST.36 bilaterally, and the same site at 100 Hz bilaterally. Na(99m)TcO(4) (7.4 MBq) was administrated via the ocular-plexus and, 20 minutes before sacrifice, blood was withdrawn for radiolabeling assay (BRL). In the bioavailability analysis, organs and tissues were isolated, their radioactivity determined, and the percentage of injected dose per gram of organ or tissue (%ID/g) and the %ID were calculated for each organ or tissue (%ID/ot). For BRL, the plasma and blood cells isolated, and the fractions also precipitated with 5% trichloroacetic acid to separate the soluble and insoluble fractions; these were assessed as percentage of injected dose (%ID) in blood (%ID/b). RESULTS: The results showed significant differences in the %ID/g in some organs and tissues in comparison with controls; lung (p = 0.0013), spleen (p = 0.0085), pancreas (p = 0.0167), liver (p = 0.0003), stomach (p < 0.0001), small-intestine (p = 0.0181), large-intestine (p = 0.04099), urinary-bladder (p = 0.0271), thyroid (p < 0.0001), muscle (p = 0.0187); %ID/ot in spleen (p = 0.0349); and %ID/b in blood sample (p = 0.0235). In the blood labeling analyses, EA in either frequency significantly increased insoluble fraction/blood cells (p < 0.0001). CONCLUSIONS: These findings suggested that acupuncture procedures at ST.36 could modulate responses in some organs, tissues, and blood in rats. Further rigorous experimental studies to examine the effectiveness in either acupuncture therapy need to be pursued.

Effects of Passiflora edulis flavicarpa on the radiolabeling of blood constituents, morphology of red blood cells and on the biodistribution of sodium pertechnetate in rats.

The aim of this study was to evaluate possible effects of Passiflora edulis flavicarpa (P. flavicarpa) extract on the labeling of blood constituents with (99m)Tc, on the morphology of red blood cells, and on the biodistribution of sodium pertechnetate (sodium (99m)Tc). Male Wistar rats were treated with either P. flavicarpa extract or 0.9% NaCl. After that, radiolabeling of blood constituents, morphological analysis of red blood cells and biodistribution of sodium (99m)Tc was evaluated. Radiolabeling of blood constituents and shape of red blood cells were not modified, but a significant (p<0.05) alteration of the biodistribution of sodium (99m)Tc was observed after treatment with P. flavicarpa extract. Although our results were obtained with animals, they could contribute to reduce the risk of misdiagnosis and/or repetition of the examinations in nuclear medicine.

Evaluation of the in vitro effect of a Lantana camara extract on the labeling of blood constituents of rats with technetium-99m.

Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures and drugs are capable to interfere on this labeling. Lantana camara (lantana) has medicinal properties and it has been used in folk medicine. The aim is to verify the effect of a lantana extract on the labeling of blood constituents with 99mTc. Blood of rats was incubated with extract, stannous chloride and 99mTc, as sodium pertechnetate. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) were separated. The % of radioactivity (%ATI) in these samples was calculated. Samples of labeled BC were washed and the %ATI maintained (%ATI-M) in the BC was determined. The results showed that lantana extract decreased significantly (p < 0.05) in the IF-P from 70.24 +/- 2.59 to 11.95 +/- 3.07. This effect was not observed in the BC and IF-BC. The BC-%ATI-M was significantly (p < 0.05) decreased in all concentrations tested when the BC was washed. This fact was not observed in the control. Substances present on the extract should have redoxi action decreasing the concentration of the stannous ion and this condition could justify the effect on the IF-P. The results about the BC-%ATI-M should indicate a possible effect on the transport of ions through the erythrocyte membrane.

The ingestion of a Nectandra membranacea extract changes the bioavailability of technetium-99m radiobiocomplex in rat organs.

The radiobiocomplexes labeled with technetium-99m (Tc-99m) have been widely used in nuclear medicine in single photon emission computed tomography and in basic research. The aim of this study was to assess the influence of a Nectandra membranacea extract on the bioavailability of the sodium pertechnetate (Na(99m)TcO(4)) radiobiocomplex in rat organs. The animals were treated with a N. membranacea extract (30 mg/ ml), for 6 days. Na(99m)TcO(4) was injected, the organs were isolated and weighed, and the radioactivity was determined in each organ (%ATI/organ). The %ATI/organ was divided by the mass of each organ to calculate the %ATI/g. A significant increase of the %ATI/organ of Na(99m)TcO(4) was observed in muscle and thyroid as well as in the %ATI/g in the heart, kidney and thyroid. These findings could result from the interaction between components of the plant extract and the radiobiocomplex which may influence the uptake Na(99m)TcO(4) in rat organs. Therefore, precaution is suggested in the interpretation of nuclear medicine results in patients using this herb.

Effect of oral ingestion of an extract of the herb Uncaria tomentosa on the biodistribution of sodium pertechnetate in rats.

The aim of the present study was to determine the effect of the oral ingestion of an extract of the herb Uncaria tomentosa (cat's claw) on the biodistribution of the radiobiocomplex sodium pertechnetate (Na99mTcO4) in rats. The animals (male Wistar rats, 2 months old, 180-220 g), were treated (1 mL) with an U. tomentosa extract (32 mg/mL, N = 5) or 0.9% NaCl solution (control, N = 5) for 7 days. After this period, Na99mTcO4 (3.7 MBq, 0.3 mL) was injected through the ocular plexus and after 10 min the rats were killed, the organs isolated and counted in a well-gamma counter. A significant (P < 0.05) alteration in Na99mTcO4 uptake i) from 0.57 +/- 0.008 to 0.39 +/- 0.06 %ATI/organ (P < 0.05) and from 0.57 +/- 0.17 to 0.39 +/- 0.14 %ATI/g (P < 0.05) was observed in the heart, ii) from 0.07 +/- 0.02 to 0.19 +/- 0.07 %ATI/g in the pancreas, and iii) from 0.07 +/- 0.01 to 0.18 +/- 0.07 %ATI/g (P < 0.05) in muscle after treatment with this extract. Although these results were obtained with animals, caution is advisable in the interpretation of the nuclear medicine examination when the patient is using this herb. This finding is probably an example of drug interaction with a radiopharmaceutical, a fact that could lead to misdiagnosis of the examination in clinical practice with unexpected consequences for the patient.

Acupuncture stimulation at Sanyinjiao: effect on the sodium pertechnetate bioavailability in rats.

In clinical acupuncture, when acupuncture points are stimulated, several types of reflex responses can be evoked. Consequently, different categories of physiological responses are induced, which include changes in the activities of internal organs and tissues. The acupuncture point Sanyinjiao (SP6) has been used successfully to treat different human gastrointestinal conditions. The aim of this work was to investigate the effects of end-organ response induced by acupuncture point SP6 on the bioavailability of the radiopharmaceutical sodium pertechnetate (Na99mTcO4) in Wistar rats. Healthy rats were allocated into 2 groups, control-CG and treated-TG. TG was bilaterally stimulated at acupuncture point SP6 with stainless steel needles. Ocular plexus administration of Na99mTcO4 (3.7MBq) was carried out 10 min after every needle insertion in all animals. Ten minutes later, the animals were killed, the organs were isolated, the radioactivity was determined in a well gamma counter, and the percentage of injected dose per gram of tissue (%ID/g) was determined for each organ. The %ID/g was significantly altered (p < 0.05) in the small intestine of TG (0.56 +/- 0.09) when compared to CG (0.82 +/- 0.18). These results may suggest that this stimulation might induce physiological responses capable of altering the bioavailability of the radiopharmaceutical sodium pertechnetate. These findings aid in providing a better understanding of acupuncture and its effects on various organs and tissues.

Experimental model to assess possible medicinal herb interaction with a radiobiocomplex: qualitative and quantitative analysis of kidney, liver and duodenum isolated from treated rats.

Ginkgo biloba extract (EGb) has been used as a medicinal herb. Several biological properties have been associated with this extract, especially, in the increase of the blood flow, in the action as platelet activating factor antagonism and in the prevention of the membrane against the damage caused by free radicals. Radiobiocomplexes have been utilized in various nuclear medicine procedures helping in the diagnosis and/or treatment of human diseases. Many substances have been reported to affect the bioavailability of different radiobiocomplexes. The aim of this work was to evaluate the possible influence of an EGb on the bioavailability of the sodium pertechnetate (99mTcO4Na) and on the morphometry of some organs isolated from rats. These animals were treated with EGb and 99mTcO4Na was injected. The animals were sacrificed, the organs isolated, counted in a well counter and the percentage of radioactivity per gram of each organ was calculated. The results showed that EGb decreased the uptake of the 99mTcO4Na in the duodenum (P<0.05). Moreover, morphometric analysis has revealed significant modifications (P<0.05) on kidney, liver and duodenum due to the cited treatment. It is speculated that the substances present in the EGb could act directly or generate metabolites capable to promote changes in organs (kidney, liver and duodenum), however, only significant alteration in the uptake of the 99mTcO4Na in the duodenum.

The effect of "Zusanli" (ST. 36) acupuncture on the bio-availability of sodium pertechnetate in Wistar rats.

The effect of acupuncture stimulation at Zusanli point (ST.36) on the bioavailability of radio-pharmaceutical 99mTc-sodium pertechnetate (Na99mTcO4) in Wistar rats was investigated. Ten healthy rats were allocated into two groups of five. Group 1 (n=5) was treated by acupuncture by inserting stainless steel needles bilaterally at ST.36; Group 2 was the untreated control. Ocular plexus administration of 0.3ml of Na99mTcO4 (3.7MBq) was carried out 10 minutes after every needle insertion. The rats were killed 25 minutes later. The organs were isolated, the radioactivity determined in a well gamma counter, and the percentage of injected radio-pharmaceutical dose per gram of tissue (%ID/g) was assessed for each organ. The %ID/g varied significantly (p<0.05) between Group 1 and Group 2 in pancreas (0.91 +/- 0.17 vs 0.15 +/- 0.03), stomach (7.97 +/- 0.68 vs 3.51 +/- 0.22), spleen (0.97 +/- 0.11 vs 0.41 +/- 0.14), brain (0.19 +/- 0.09 vs 0.09 +/- 0.04), kidneys (0.91 +/- 0.17 vs 0.15 +/- 0.03), heart (0.81 +/- 0.17 vs 0.31 +/- 0.02) and testis (0.46 +/- 0.04 vs 0.14 +/- 0.03). These findings suggest that the effect of acupuncture at ST.36 modulated organs and tissues responses in rats. Using Chinese theories of Zang-Fu and Five Phases, we suggest that the relationship between acupoints and organs may be related to neuromodulation mechanisms such as somatovisceral reflex responses, which play an important role in the autonomic nervous system. These results also suggest that the effect of acupuncture on the bio-availability of radio-pharmaceuticals may help our understanding of the action of acupuncture points on various organs and tissues.

[Effect of Hypericum perforatum extract on in vitro labelling of blood elements with technetium-99m and on biodisponibility of sodium pertechnetate in Wistar rats]. / Efeito de um extrato de Hipérico (Hypericum perforatum) na marcação in vitro de elementos sangüíneos com tecnécio-99m e na biodisponibilidade do radiofármaco pertecnetato de sódio em ratos Wistar.

PURPOSE: To evaluate the effect of a hiperico extract (Hypericum perforatum) on the labeling of blood elements with technetium-99m (99mTc) and in the bioavailability of the radiopharmaceutical sodium pertechnetate in Wistar rats. METHODS: Blood (heparinized) withdrawn from Wistar rats is incubated with a hiperico extract, with a stannous cloride and with 99mTc, as sodium pertechnetate (99mTcONa). Plasma (P) and cells (C) are isolated by centrifugation. Samples of P and C are also precipitated with trichloroacetic acid (TCA 5%) and soluble (FS-P; FS-C) and isoluble (FI-P; FI-C) fractions are separated. In the bioavailability analysis, the extract or NaCl 0.9% solution is administrated into Wistar rats (gavage) during 15 days. Sodium pertechnetate was administered and after 10 min, the animals are sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs are calculated. RESULTS: The hiperico extract decreasedsignificantly (P < 0.05) the %ATI in the cells, cellular insoluble fraction and plasma insoluble fraction. The biodistribution was significantly (P < 0.01) decreased in bone, muscle and thyroid and significantly (P < 0.05) increased in pancreas. CONCLUSION: The analysis of the results indicates that in studied extract should have substances that should oxidize the stannous ion, reducing the fixation of the 99mTc on the erythrocytes and plasma and cellular proteins. Moreover, it could produce metabolic alterations with influence in the uptake of the radiopharmaceutical 99mTcO4Na in bone, muscle, pancreas and thyroid.

Radioactive iodine and the salivary glands.

Radioactive iodine ((131)I) targets the thyroid gland and has been proven to play an effective role in the treatment of differentiated papillary and follicular cancers. Simultaneously, this radioisotope hones in on the salivary glands where it is concentrated and secreted into the saliva. Dose related damage to the salivary parenchyma results from the (131)I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of (131)I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, stomatitis, candidiasis, and neoplasia. Prevention of the (131)I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Recently, amifostine has been advocated to prevent the effects of irradiation. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration.

"Hot" carcinoma of the thyroid. Case reports and comments on the literature.

It seems somewhat difficult to exactly define the real number of case reports concerning the association of hyperfunctioning thyroid node and carcinoma; the overall incidence of this condition seems, however, to be very rare. Different inclusion criteria are probably a fairly relevant cause of variability in the number of cases reported during the years. A basic classification scheme, as the one here reported, may be of help in characterizing the different possible conditions: 1. the coexistence of carcinoma and focally hyperfunctioning tissue in the same gland but at different locations (not uncommon); 2. the presence of such a large tumour mass that it can compete with normal tissue for tracer uptake, despite being hormonogenetically uneffective in itself; 3. the carcinoma located in the hyperfunctioning adenoma; 4. the real hyperfunctioning carcinoma, where coincidence between hyperfunctioning tissue and malignancy is complete (very rare). Two cases are reported here, respectively belonging to the third and fourth of these categories (the most challenging from a diagnostic point of view). The matter is intrinsically poor from a statistical standpoint: it is therefore difficult to draw definitive conclusions on the subject in operative terms. It is however felt that the systematic evaluation of oncological risk in thyroid nodes, occasionally recommended in the literature, may be cumbersome and not necessarily cost-effective.

Effect of eggplant (Solanum melongena) extract on the in vitro labeling of blood elements with technetium-99m and on the biodistribution of sodium pertechnetate in rats.

The use of eggplant has been suggested to treat different diseases. We studied the effect of eggplant extract on the labeling of red blood cells (RBC) and plasma proteins with technetium-99m (Tc-99m) and on biodistribution of sodium pertechnetate (Tc-99m) in rats. Blood was incubated with an eggplant extract (final concentrations 3.12 to 250.00 mg/ml) for 60 min. Then, stannous chloride (SnCl2) (0.06 or 1.2 microg/ml) and Tc-99m, as sodium pertechnetate, were added. Samples of RBC and plasma (P) were separated and also precipitated and soluble (SF) and insoluble (IF) fractions were isolated. The percent of radioactivity (%ATI) in the fractions was calculated. In the biodistribution study, Wistar rats were treated with eggplant extract (300 mg/ml) for 4 weeks, in drinking water. Tc-99m was administered in the rats, after 90 min they were sacrificed and organs and blood were isolated. When 0.06 microg/ml SnCl2 was used, eggplant extract: i/ inhibited the label of RBC (97.14 +/- 2.01 to 52.21 +/- 3.97%ATI), ii/ decreased the labeling in IF-P from 38.79 +/- 11.73 to 5.49 +/- 2.65%ATI, and iii/ diminished the labeling in IF-RBC from 90.04 +/- 2.65 to 46.17 +/- 9.49%ATI. This inhibitory effect was not observed with SnCl2 1.2 microg/ml. In the biodistribution study, the %ATI: i/ increased in the liver from 2.15 +/- 0.54 to 3.11 +/- 1.29 and ii/ in the other organs the Tc-99m uptake was not modified. The uptake of Tc-99m in red blood cells protein (IF-RBC) decreased from 66.62 +/- 19.67 to 31.66 +/- 8.84%. It is possible to suggest that some components of the eggplant extract present an oxidation power able to alter the fixation of the Tc-99m on the blood elements. Moreover, as eggplant is metabolized in the liver, this fact could justify the alteration of the uptake in this organ.

Radioprotection of salivary glands by S-2-(3-aminopropylamino)-ethylphosphorothioic (amifostine) obtained in a rabbit animal model.

BACKGROUND: Impairment of salivary gland function following high-dose radioiodine treatment (HDRIT) is a well-recognized side effect of the treatment. Because differentiated thyroid cancer has an excellent prognosis, reduction of long-term side-effects is mandatory. Therefore, the aim of this study was to investigate the radioprotective effect of amifostine in a rabbit animal model. METHODS: Salivary gland scintigraphy was performed in a total of 16 New Zealand White rabbits. Uptake of 99-Tc-pertechnetate was calculated in percentage of injected activity as a quantitative measure of both salivary gland and thyroid function. Reproducibility of salivary gland scintigraphy was evaluated in one rabbit without any intervention. Fifteen rabbits were studied prior to and up to 6 months after high-dose radioiodine treatment applying 2 GBq 131I. Ten animals received 200 mg/kg amifostine prior to high-dose radioiodine therapy, and 5 served as controls. Salivary glands were examined histopathologically. RESULTS: Variation coefficient of parenchymal function was less than 3.8% in salivary glands. Prior to HDRIT, thyroid uptake was 0.417+/-0.373% and 0.421+/-0.241% in control and amifostine-treated rabbits, respectively. Four weeks after HDRIT, complete ablation of the thyroid was achieved in both groups. Prior to HDRIT, uptake of 99mTc-pertechnetate in salivary glands of five control rabbits was not significantly different from ten amifostine-treated rabbits. In control rabbits 6 months after HDRIT, parenchymal function was reduced significantly (p < 0.0001) by 75.3+/-5.3% and 53.6+/-17.4% in parotid and submandibular glands, respectively. In contrast, in amifostine-treated rabbits, parenchymal function was reduced by 10.6+/-3.4% and 6.5+/-4.3% (p > 0.05) in parotid and submandibular glands, respectively. Histopathologically, marked lipomatosis was observed in control animals but was negligible in amifostine-treated animals. CONCLUSION: Parenchymal damage in salivary glands induced by high-dose radioiodine treatment can be significantly reduced by amifostine in this rabbit animal model. This corresponds to data obtained in patients with differentiated thyroid cancer.

Transferrin-dependent uptake and dosimetry of Auger-emitting diagnostic radionuclides in human spermatozoa.

UNLABELLED: Localization of Auger-emitting radionuclides within spermatozoa could lead to the induction of transmissible genetic damage. We have quantified in vitro uptake of the widely used diagnostic Auger-emitters, (111)In and 99mTc, by ejaculated human spermatozoa and investigated the role of transferrin in their cellular localization. The resultant dose to sperm heads, including cellular dosimetry for Auger emissions, has been calculated for each radionuclide and compared with that achieved using conventional macrodosimetry. METHODS: Freshly isolated human spermatozoa were incubated in a physiological salt solution containing (111)In-chloride, 99mTc-pertechnetate or the transferrin-binding isotope 59Fe-citrate as a positive control. Cellular uptake mechanisms were investigated with transferrin competition and temperature dependence studies. The percentage uptake of each radionuclide was determined, and the dose to individual sperm heads was calculated using both conventional macrodosimetric methods and by consideration of radionuclide localization and energy deposition at the cellular level, including Auger electron emissions from (111)In and 99mTc. RESULTS: On in vitro incubation, human spermatozoa were found to accumulate (111)In and 59Fe but not 99mTc. Cell uptake of (111)In and 59Fe was transferrin-mediated; however, an alternative transferrin-independent uptake pathway was also present for (111)In. The dose to sperm heads from (111)In, calculated using measured uptake and cellular dosimetry, was found to be larger than that calculated using conventional dosimetry by a factor of more than 100. In contrast, conventional dosimetry was adequate for 99mTc and 59Fe. CONCLUSION: Isolated human spermatozoa appear to accumulate transferrin-binding isotopes, such as the Auger-emitter (111)In. If this uptake mechanism operates in the male reproductive tract, the resultant high dose to the sperm head could indicate that contraception may be advisable after large diagnostic doses of (111)In and, possibly, other transferrin-binding radionuclides. Such precautions could prevent transmission of any genetic damage from irradiated spermatozoa.

A developmental analysis of differences in the uptake of [123I]isopropyliodoamphetamine versus 99mTc-pertechnetate by the choroid plexus and brain.

The uptake of intravascular [123I]isopropyliodoamphetamine (IMP) and 99mTc-pertechnetate into choroid plexus (CP) and brain (frontal cortex) was studied by an indicator fractionation method applied to immature, ketamine-anesthetized Sprague-Dawley rats (1.5, 2, and 3 wk). Assessment of the rate and extent of uptake of these indicators provides functional information (eg blood flow; transport) about various regions of the developing CNS. IMP uptake by lateral ventricle CP was 1.15 ml/g/min in 1.5-wk-old infant rats and gradually increased to 3.9 mg/g/min by adulthood (7-8 wk) (P < 0.05); over the same postnatal period, 99mTc uptake went from 2.82 to 3.18 ml/g/min. IMP uptake by cortex was 0.39 and 0.99 ml/g/min in infants and adults, respectively (P < 0.05); however, 99mTc uptake by cortex was only 0.07 +/- 0.01 ml/g/min at all ages, reflecting early development of blood-brain barrier (BBB) to pertechnetate. Overall, our findings indicated a progressive increase with age in the rate of uptake of IMP by CP and brain; and that 99mTc penetration into CP was relatively constant and substantially greater than into cortex at all developmental stages. Thus the nature of uptake of IMP, relative to 99mTc, was markedly different at the blood-cerebrospinal fluid barrier (i.e., CP) vs. the blood-brain barrier.

A combined method for quantitative pertechnetate scintigraphy in the diagnosis of sacroiliitis. A controlled study.

A simplified scintigraphic technique for the assessment of sacroiliitis is described. It is based on the fact that an inflamed joint shows increased perfusion activity after administration of sodium pertechnetate. The sacroiliac joints are located by injection of a small amount of bone-seeking activity. Thereafter the pertechnetate activity is injected and the bone-seeking activity subtracted. The perfusion (pertechnetate) activity of the sacro-iliac joints is related to the activity of the large vessels of the thigh. Normal values have been established based on a study of 39 healthy controls. The method has been applied to 2 groups of patients with clinical sacroiliitis, one with and one without radiographical signs of sacroiliitis. The patients with radiographically verified sacroiliitis showed significantly higher values than the controls. The technique offers a high specificity and a high positive predictive value.