Biomedical subjects

Seigo Kinuya

Publications and source records attributed to Seigo Kinuya.

At least 19 recordsLinked to original sources

PubMed2007

Intraperitoneal radioimmunotherapy to treat the early phase of peritoneal dissemination of human colon cancer cells in a murine model.

BACKGROUND AND AIM: In patients with a high risk of peritoneal dissemination of colon cancer, a treatment adjuvant to surgical resection would improve their prognosis. We aimed to determine whether radioimmunotherapy employing radiolabelled monoclonal antibody would work in this situation. METHODS: A murine model of peritoneal dissemination was established in female Balb/c nu/nu mice by intraperitoneal injection of LS180 human colon cancer cells. Radioimmunotherapy with 7.4 MBq of a murine IgG1, anti-colorectal A7 monoclonal antibody, radiolabelled with (131)I by the chloramine-T method was conducted intraperitoneally on days 0, 3, 7 and 14 after cell inoculation, respectively. RESULTS: Radioimmunotherapy at any timing improved survival of mice as compared with those of non-treated mice and mice treated with a daily dose of 30 mg x kg(-1) of 5-fluorouracil for 4 consecutive days. The best improvement was obtained when radioimmunotherapy was conducted on day 0. CONCLUSION: These results indicate that intraperitoneal radioimmunotherapy may effectively kill colon cancer cells disseminated in the peritoneal cavity before formation of tumours and, therefore, may work as an adjuvant treatment to prevent peritoneal metastasis of colon cancer.

Animals↗

PubMed2007

Therapeutic effects of a 186Re-complex-conjugated bisphosphonate for the palliation of metastatic bone pain in an animal model.

UNLABELLED: Previously, based on the concept of bifunctional radiopharmaceuticals, we developed a highly stable (186)Re-mercaptoacetylglycylglycylglycine (MAG3) complex-conjugated bisphosphonate, [[[[(4-hydroxy-4,4-diphosphonobutyl)carbamoylmethyl]carbamoylmethyl]carbamoylmethyl]carbamoylmethanethiolate] oxorhenium(V) ((186)Re-MAG3-HBP), for the treatment of painful bone metastases. This agent showed a superior biodistribution as a bone-seeking agent in normal mice when compared with (186)Re-1-hydroxyethylidene-1,1-diphosphonate ((186)Re-HEDP). In this study, we evaluated the therapeutic effects of (186)Re-MAG3-HBP using an animal model of bone metastasis. METHODS: The model was prepared by injecting syngeneic MRMT-1 mammary tumor cells into the left tibia of female Sprague-Dawley rats. (186)Re-MAG3-HBP (55.5, 111, or 222 MBq/kg) or (186)Re-HEDP (55.5 MBq/kg) was then administered intravenously 21 d later. To evaluate the therapeutic effects and side effects, tumor size and peripheral blood cell counts were determined. Palliation of bone pain was evaluated by a von Frey filament test. RESULTS: In the rats treated with (186)Re-HEDP, tumor growth was comparable with that in untreated rats. In contrast, when (186)Re-MAG3-HBP was administered, tumor growth was significantly inhibited. Allodynia induced by bone metastasis was attenuated by treatment with (186)Re-MAG3-HBP or (186)Re-HEDP, but (186)Re-MAG3-HBP tended to be more effective. CONCLUSION: These results indicate that (186)Re-MAG3-HBP could be useful as a therapeutic agent for the palliation of metastatic bone pain.

Animals↗

PubMed2006

Radioiodinated VEGF to image tumor angiogenesis in a LS180 tumor xenograft model.

INTRODUCTION: Angiogenesis is essential for tumor growth or metastasis. A method involving noninvasive detection of angiogenic activity in vivo would provide diagnostic information regarding antiangiogenic therapy targeting vascular endothelial cells as well as important insight into the role of vascular endothelial growth factor (VEGF) and its receptor (flt-1 and KDR) system in tumor biology. We evaluated radioiodinated VEGF(121), which displays high binding affinity for KDR, and VEGF(165), which possesses high binding affinity for flt-1 and low affinity for KDR, as angiogenesis imaging agents using the LS180 tumor xenograft model. METHODS: VEGF(121) and VEGF(165) were labeled with (125)I by the chloramine-T method. Biodistribution was observed in an LS180 human colon cancer xenograft model. Additionally, autoradiographic imaging and immunohistochemical staining of tumors were performed with (125)I-VEGF(121). RESULTS: (125)I-VEGF(121) and (125)I-VEGF(165) exhibited strong, continuous uptake by tumors and the uterus, an organ characterized by angiogenesis. (125)I-VEGF(121) uptake in tumors was twofold higher than that of (125)I-VEGF(165) (9.12+/-98 and 4.79+/-1.08 %ID/g at 2 h, respectively). (125)I-VEGF(121) displayed higher tumor to nontumor (T/N) ratios in most normal organs in comparison with (125)I-VEGF(165). (125)I-VEGF(121) accumulation in tumors decreased with increasing tumor volume. Autoradiographic and immunohistochemical analyses confirmed that the difference in (125)I-VEGF(121) tumor accumulation correlated with degree of tumor vascularity. CONCLUSION: Radioiodinated VEGF(121) is a promising tracer for noninvasive delineation of angiogenesis in vivo.

Angiostatins↗

PubMed2006

A simple and rapid radiochemical choline acetyltransferase (ChAT) assay screening test.

A simple radiochemical choline acetyltransferase (ChAT) assay screening test was developed by measuring for [(3)H]acetylcholine ([(3)H]ACh) formed from 0.2 mM [(3)H]acetyl-coenzyme A ([(3)H]acetyl-CoA) and 1 mM choline by 0.2 mg of rat brain homogenates containing ChAT into 96-well microplates. A simple and rapid procedure for isolating [(3)H]ACh from the incubation mixture into 96-well microplates was achieved by using a sodium tetraphenylboron (Kalibor) solution (in ethyl acetate, 0.75%, w/v) and a hydrophobic liquid scintillator mixture (1:5, v/v, 0.2 mL) as an extraction solvent. The benefits of this radiochemical method using 96-well microplates are as follows: (1) this method is reliable and reproducible; (2) many samples can be examined at the same time by this method; (3) this method is economical and effective in reducing radioactive waste. The development of a new simple radiochemical ChAT assay screening test is the first stage of development of radiolabeled ChAT mapping agent.

Acetylcholine↗

PubMed2006

99mTc-sestamibi to monitor treatment with antisense oligodeoxynucleotide complementary to MRP mRNA in human breast cancer cells.

OBJECTIVE: Technetium-99m sestamibi (MIBI) has been utilized to evaluate multi-drug resistance (MDR) phenomenon of malignant tumors and to predict chemotherapeutic effects on them. The current investigation examined the possibility of monitoring changes with respect to mRNA expression of multi-drug resistance associated protein (MRP) following antisense oligodeoxynucleotide (AS-ODN) treatment involving 99mTc-MIBI. METHODS: The human breast cancer MCF-7 cell line and its MDR-induced MCF-7/VP cell line were employed. Cell suspensions of the two cell lines at 1 x 10(4) cells/ml were inoculated in 24-well plates (0.2 ml/well) and incubated for one day. Antisense (AS) 20-mer phosphorothioate ODN complementary to the coding region of MRP mRNA and its sense (S) ODN were administered at final concentrations up to 25 microM, followed by a 5-day incubation. 99mTc-MIBI solution was added to each well and incubated for 30 min. Cellular 99mTc-MIBI uptake was corrected for protein concentration. MRP mRNA expression levels were analyzed via the reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Cellular uptake of 99mTc-MIBI in MCF-7/VP cells was only 15% of that of MCF-7 cells. Following AS-ODN treatment at 25 microM for five days, 99mTc-MIBI uptake in MCF-7/VP cells increased 2.4-fold in comparison with non-treated control cells. 99mTc-MIBI uptake in MCF-7 cells was unaffected by AS-ODN administration. Sense ODN did not alter uptake in either cell line. RT-PCR confirmed reduction of MRP mRNA in MCF-7/VP cells following AS-ODN treatment. CONCLUSION: Effects of AS-ODN administration on MRP function can be monitored via assessment of cellular uptake of 99mTc-MIBI.

Breast Neoplasms↗

PubMed2006

Respiratory distress caused by radioiodine therapy in patients with differentiated thyroid cancer.

Respiratory distress accompanied by stridor is an uncommon complication of 131I radioiodine therapy for differentiated thyroid cancer that occurs within 48 hours of treatment. This report presents three cases with papillary thyroid carcinoma in which 131I therapy caused this acute complication. One of them had no apparent risk for this complication such as the existence of remnant thyroid tissue or laryngeal problems before the treatment. These cases remind physicians that 131I therapy is not a simple, riskless procedure.

Aged↗

PubMed2006

Binding with serum components favorably affects cellular uptake of 111In-oligonucleotide in a leukemia cell line.

PURPOSE: The influence of serum components on the intracellular uptake of an 111In-oligonucleotide (ODN) against mdr1 mRNA was investigated in the murine leukemia cell line, P388/S, and its mdr1-overexpressed P388/R. METHODS: 111In-ODNs naked and vectorized with lipids were analyzed for binding with serum components using high-performance liquid chromatography (HPLC). 111In-ODN was incubated in albumin and transferrin solutions. 111In-DTPA and 111In-mononucleotide were incubated in serum. Degradation of naked 111In-ODN was detected in phosphate buffered saline (PBS) and serum containing endonuclease S1. Cellular uptakes of naked and vectorized 111In-ODN in the above cells were examined with and without fetal calf serum (FCS). RESULTS: Time-dependent binding of naked and vectorized 111In- ODN with serum components was observed throughout 24 hours. Transchelation of 111In to transferrin was not detected. HPLC profiles of 111In-DTPA and 111In-mononucleotide did not change in serum. Degradation of 111In-ODN by S1 was less remarkable in serum than in PBS. Specific accumulation of vectorized 111In-ODN in P388/R cells was achieved in culture with and without 10% FCS. CONCLUSIONS: This study verified the intense binding of ODN with serum components, leading to no inhibition on ODN intracellular specific uptake. Binding with serum components protects 111In-ODN from degradation by endonuclease and thus may facilitate ODN transmembrane delivery.

Animals↗

PubMed2005

Locoreginal radioimmunotherapy with 186Re-labeled monoclonal antibody in treating small peritoneal carcinomatosis of colon cancer in mice in comparison with 131I-counterpart.

The efficacy of locoregional radioimmunotherapy (RIT) in treating peritoneal tumors of colon cancer of <2 mm in diameter was examined at maximum tolerated doses, focusing the comparison between 186Re and 131I labeled to an anti-colorectal cancer IgG1. Estimated radiation doses to tumors were considerably higher with 186Re-RIT than with 131I-RIT. The advantage of 186Re-RIT decreased with decreasing tumor size, but 186Re-RIT delivered 1.6-times higher radiation to tumors of 1 mm. Consequently, 186Re-RIT attained better survival of mice than 131I-RIT or chemotherapy with 5-fluorouracil did. Therefore, locoregional 186Re-RIT may be an option in an adjuvant setting of colon cancer with high risk of peritoneal dissemination.

Animals↗

PubMed2005

Characterization of cartilaginous tumors with 201Tl scintigraphy.

UNLABELLED: Histological diagnosis and grading of cartilaginous tumors are closely correlated with patient prognosis; consequently, they are essential elements. We attempted to clarify the characteristics of 201Tl uptake in various histological types of cartilaginous tumors and to assess its clinical value. METHODS: Twenty-two cases with histologically proven cartilaginous tumors (3 enchondromas, 15 conventional chondrosarcomas (grade I = 9, II = 5, III = 1), 3 mesenchymal chondrosarcomas, and 1 de-differentiated chondrosarcoma) were examined retrospectively. Planar 201Tl images were recorded 15 min following intravenous injection of 201Tl (111 MBq). 201Tl uptake in the tumor was evaluated visually employing a five-grade scoring system: 0 = no appreciable uptake, 1 = faint uptake above the background level, 2 = moderate uptake, 3 = intense uptake but lower than heart uptake and 4 = uptake higher than heart uptake. RESULTS: 201Tl uptake scores were 0 in 3 of 3 enchondromas, 9 of 9 grade I, and 4 of 5 grade II conventional chondrosarcomas. 201Tl uptake scores were 1 among 1 of 5 grades II and a grade III conventional chondrosarcoma. Mesenchymal chondrosarcoma and de-differentiated chondrosarcoma displayed 201Tl uptake scores of 2 or 3. CONCLUSIONS: Absence of elevated 201Tl uptake in cartilaginous tumors was indicative of enchondroma or low-grade conventional chondrosarcoma. However, in instances in which 201Tl uptake is obvious, high-grade chondrosarcoma or variant types should be considered.

Adult↗

PubMed2005

Anti-angiogenic therapy and chemotherapy affect 99mTc sestamibi and 99mTc-HL91 accumulation differently in tumour xenografts.

BACKGROUND: Favourable effects of cytotoxic chemotherapy for tumours are characterized by the reduced accumulation of radiotracers such as 99mTc sestamibi (MIBI). Anti-angiogenic therapy is primarily cytostatic; consequently, its influence on tracer accumulation may differ from that of cytotoxic treatments. METHODS: Anti-angiogenic therapy employing 2-methoxyestradiol was administered in mice bearing subcutaneous xenografts of LS180 colon cancer cells. The effects of chemotherapy with 5-fluorouracil were examined as a cytotoxic counterpart. Treatments were conducted for 4 days from day 8. Distribution of 99mTc-MIBI and Tc-HL91, a hypoxic marker, was observed on days 8 and 12. Oxygen tension (PO2) in tumours was measured by a microelectrode. Cellular uptake of tracers was examined in vitro in normoxic and hypoxic conditions. RESULTS: 99mTc-MIBI accumulation decreased with increasing tumour weight when no treatment was conducted. Tumour growth was suppressed by anti-angiogenic therapy and chemotherapy. 99mTc-MIBI accumulation in tumours decreased after chemotherapy as compared to pre-therapeutic values, whereas accumulation of 99mTc-HL91 increased. In contrast, accumulation of tracers did not significantly change after anti-angiogenic therapy as compared to that observed pre-therapeutically. Tumour PO2 decreased with increasing tumour volume when no treatment was conducted. Chemotherapy reduced PO2 in tumours. PO2 in tumours treated with anti-angiogenic therapy was as high as that observed before treatment. 2-Methoxyestradiol or 5-fluorouracil did not significantly affect tracer accumulation in cells under both normoxic and hypoxic conditions in vitro. CONCLUSION: These findings indicate that scintigraphic assessment of therapeutic efficacy of anti-angiogenic therapy should be performed from a perspective distinct from that of cytotoxic treatment.

2-Methoxyestradiol↗

PubMed2005

Tc-99m MAA SPECT in pectus excavatum: assessment of perfusion volume changes after correction by the Nuss procedure.

PURPOSE: The Nuss procedure is a minimally invasive technique for the repair of pectus excavatum. This investigation attempted to assess the impact of this corrective protocol on pulmonary functional volume through analysis of distribution volume data derived from Tc-99m MAA SPECT. MATERIAL AND METHODS: SPECT was performed in 3 patients before and 6 months after completion of the Nuss procedure. Before the clinical application of SPECT, phantom experiments were conducted to establish the threshold level based on the volume calculation program. Haller's index, a quantitative index of chest-wall deformity, was also obtained by x-ray CT. RESULTS: A threshold level of 30% was the most accurate determinant of pulmonary volume. Preoperative and postoperative Tc-99m MAA distribution volumes (MAA volume in mL) were 2812 and 3107 (an increase of 10%), 2212 and 2410 (9%), and 2341 and 2872 (23%), respectively. In all patients, MAA volume increased after corrective intervention. Changes were most striking in the left lung, which is affected to a greater extent by dislocation of the heart. Morphologic improvement in the lungs was also demonstrated by Haller's CT index in all patients, which decreased from 4.35, 3.52, and 10.67, preoperatively, to 3.45, 2.75, and 4.25, respectively, postoperatively. CONCLUSION: MAA volume assessment is an easy, suitable approach for detection of favorable changes produced by the Nuss procedure in pectus excavatum.

Adolescent↗

PubMed2005

Time course of discordant BMIPP and thallium uptake after ischemia and reperfusion in a rat model.

UNLABELLED: Serial changes in fatty acid metabolism or use associated with acute ischemia and reperfusion were examined in rat hearts. METHODS: Male Wistar rats were subjected to occlusion of the left coronary artery for 20 min followed by reperfusion. After release of the occlusion, groups of animals were allowed to recover for intervals of 20 min (n = 9), 1 d (n = 9), 3 d (n = 6), 7 d (n = 6), or 30 d (n = 6). Hearts were excised 15-20 min after injection of 0.74 MBq of (125)I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) and 14.8 MBq of (201)Tl. One minute before resection, the left coronary artery was reoccluded and 185 MBq of (99m)Tc-sestamibi were injected to document the area at risk. Triple-tracer autoradiography was performed to assess tracer uptake. Uptake ratios of BMIPP and (201)Tl in the area at risk were calculated on the basis of the count density in the lesion divided by that in the normally perfused area. RESULTS: (201)Tl uptake did not change throughout the observation period (P = 0.25). In contrast, BMIPP uptake increased early in the acute phase (20 min and 1 d), decreased during the subacute phase (7 d), and subsequently recovered in the chronic phase (30 d). CONCLUSION: The present investigation clearly illustrated that BMIPP uptake is higher than (201)Tl uptake in the acute phase, that BMIPP uptake is lower than (201)Tl uptake in the subacute phase, and that BMIPP uptake and (201)Tl uptake are similar in the chronic phase. These results yield data essential to the precise interpretation of BMIPP images.

Animals↗

PubMed2004

In vitro detection of mdr1 mRNA in murine leukemia cells with 111In-labeled oligonucleotide.

PURPOSE: The feasibility of intracellular mdr1 mRNA expression detection with radiolabeled antisense oligonucleotide (ODN) was investigated in the murine leukemia cell line, P388/S, and its subclonal, adriamycin-resistant cell line, P388/R. METHODS: The expression level of mdr1 mRNA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Existence of the multidrug resistance (MDR) phenomenon was assessed via cellular uptake of 99mTc-sestamibi (MIBI), a known substrate for P-glycoprotein. A 15-mer phosphorothioate antisense ODN complementary to the sequences located at -1 to 14 of mdr1 mRNA and its corresponding sense ODN were conjugated with the cyclic anhydride of diethylene triamine penta-acetic acid (cDTPA) via an amino group linked to the terminal phosphate at the 5' end at pH 8-9. The DTPA-ODN complexes at concentrations of 0.1-17.4 microM were reacted with 111InCl3 at pH 5 for 1 h. The hybridization affinity of labeled ODN was evaluated with size-exclusion high-performance liquid chromatography following incubation with the complementary sequence. Cellular uptake of labeled ODN was examined in vitro. Furthermore, enhancing effects of synthetic lipid carriers (Transfast) on transmembrane delivery of ODN were assessed. RESULTS: P388/R cells displayed intense mdr1 mRNA expression in comparison with P388/S cells. 99mTc-MIBI uptake in P388/S cells was higher than that in P388/R cells. Specific radioactivity up to 1,634 MBq/nmol was achieved via elevation of added radioactivity relative to ODN molar amount. The hybridization affinity of antisense 111In-ODN was preserved at approximately 85% irrespective of specific activity. Cellular uptake of antisense 111In-ODN did not differ from that of sense 111In-ODN in either P388/S cells or P388/R cells. However, lipid carrier incorporation significantly increased transmembrane delivery of 111In-ODN; moreover, specific uptake of antisense 111In-ODN was demonstrated in P388/R cells. CONCLUSION: Radiolabeling of ODN at high specific radioactivity and specific uptake of antisense 111In-ODN in drug-resistant cells may facilitate future gene imaging of mdr1 mRNA.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Improved survival of mice bearing liver metastases of colon cancer cells treated with a combination of radioimmunotherapy and antiangiogenic therapy.

We attempted to determine whether the combined regimen of radioimmunotherapy (RIT) and antiangiogenic therapy would favorably affect the survival of animals bearing liver metastases of colon cancer cells. Daily antiangiogenic therapy with 2-methoxyestradiol (2-ME), 75 mg/kg, was initiated at 3 days following intrasplenic cell inoculation of LS180 colon cancer cells. RIT with 7 MBq of (131)I-A7, an IgG1 anti-colorectal monoclonal antibody, or (131)I-HPMS-1, an irrelevant IgG1, was conducted at 7 days. Production of vascular endothelial growth factor (VEGF) by LS180 cells was assessed in vitro. All nontreated mice died by 31 days following cell inoculation ( n=5). Monotherapy comprising 2-ME treatment resulted in slightly better survival of mice ( n=8) ( P<0.05). (131)I-A7 RIT displayed a marked therapeutic effect ( n=8) ( P<0.001); however, all animals eventually died due to metastases by 99 days. The combined regimen of (131)I-A7 RIT and antiangiogenic therapy demonstrated a superior therapeutic effect in comparison to monotherapy consisting of either RIT or antiangiogenic therapy ( n=10) ( P<0.05); three mice survived the entire 160-day observation period. The combination of antiangiogenic therapy and (131)I-HPMS-1 RIT failed to provide an appreciable benefit ( n=5). Treatment with 2-ME decreased VEGF production by LS180 cells in a dose-dependent fashion. In conclusion, a combination regimen comprising RIT and antiangiogenic therapy initiated at the early stage of metastasis would be of great benefit in terms of improvement of the therapeutic efficacy with respect to liver metastases.

Angiogenesis Inhibitors↗

PubMed2004

Multifactorial analysis on the short-term side effects occurring within 96 hours after radioiodine-131 therapy for differentiated thyroid carcinoma.

OBJECTIVE: This study was performed to clarify factors that might influence short-term side effects occurring within 96 hours after administration of 131I for patients with thyroid carcinoma. METHODS: In 71 patients with differentiated thyroid carcinoma, short-term side effects including gastrointestinal complaints, salivary gland swelling with pain, change in taste and headache were retrospectively analyzed. All patients were given domperidone for prevention of gastrointestinal complaints and advised to consume sour foods to promote discharge of radioiodine from the salivary glands. Selected factors possibly affecting the incidence of side effects were dose per body weight, TSH, effective half-life of 131I, sex, age, 131I accumulation into the stomach and salivary glands, and edema prior to radioiodine administration. The factors were evaluated by multivariate analyses. RESULTS: Incidence of gastrointestinal complaints, salivary gland swelling with pain, change in taste and headache was 65.2%, 50.0%, 9.8% and 4.4%, respectively. In gastrointestinal complaints, the incidence of appetite loss, nausea and vomiting was 60.9%, 40.2% and 7.6%, respectively. The gastrointestinal complaints increased significantly in the patients dosed above 55.5 MBq/kg and with TSH elevation. For salivary gland swelling with pain, female patients displayed a significantly higher incidence than males. No statistically significant factors were detected for change in taste or headache. CONCLUSIONS: Significant factors influencing short-term side effects were dose per body weight and TSH values for gastrointestinal complaints, and female sex for salivary gland swelling with pain. Our preliminary experience suggests that the most frequent gastrointestinal complaints can be prevented with ramosetron.

Adolescent↗

PubMed2004

Left ventricular ejection and filling rate measurement based on the automatic edge detection method of ECG-gated blood pool single-photon emission tomography.

UNLABELLED: The objective of the present investigation was to determine the feasibility of assessing left ventricular systolic ejection and diastolic filling via the automatic edge detection method employing ECG-gated blood pool single-photon emission tomography (SPET GBP) data. METHODS: Thirty-five patients, who had undergone both SPET GBP and ECG-gated equilibrium blood pool scintigraphy by the planar method (planar GBP), were enrolled in this study. Planar GBP was performed with a single-headed gamma camera. From the left anterior oblique projection, data were acquired at 24 frames/cardiac cycle with ECG-gating during the equilibrium state. SPET GBP was conducted utilizing a triple-headed gamma camera, with 60 projection views over 360 degrees by 60 sec per view, in 16 frames/cardiac cycle. In each frame, left ventricular volume was determined by automatic edge detection employing a quantitative gated SPET program. Additionally, the time-volume curve was fitted by the 4th harmonics of Fourier transform. Ejection fraction (EF, %), peak ejection rate (PER, /sec), peak filling rate (PFR, /sec) and mean filling rate during the initial one-third of diastolic time (1/3 FRm) were calculated from the fitted curve. These parameters were also calculated with planar GBP data. RESULT: Left ventricular ejection and filling parameters were calculated by SPET GBP with the automatic edge detection program for all patient data. Correlation coefficients of EF, PER, PFR and 1/3 FRm between SPET and planar GBP were 0.91 (p < 0.001), 0.82 (p < 0.001), 0.78 (p < 0.001) and 0.74 (p < 0.001), respectively. CONCLUSION: Ejection and filling rates can be calculated using SPET GBP with the edge-detection software. These parameters displayed significant correlations with those values obtained via planar GBP. Additional studies are warranted to determine the reliability of parameters with SPET GBP.

Adult↗

PubMed2004

Brown adipose tissue: evaluation with 201Tl and 99mTc-sestamibi dual-tracer SPECT.

Brown adipose tissue is one kind of adipose tissue and regulates body temperature and balance of energy via non-shivering thermogenesis. The authors present a case that strongly suggested the presence of activated brown adipose tissue in the neck, shoulders and axillary space by increased 18F-FDG uptake. 99mTc-sestamibi and 201Tl dual-tracer SPECT study showed increased 99mTc-sestamibi uptake and non-increased 201Tl uptake in the corresponding 18F-FDG uptake sites. Brown adipose tissue has dense mitochondria in the cells, which play an important role in thermogenesis. 99mTc-sestamibi uptake and retention depend on the mitochondrial activity but 201Tl uptake does not. Therefore, the activity of mitochondria in activated brown adipose tissue may explain the discrepant uptake between 99mTc-sestamibi and 201Tl.

Adipose Tissue, Brown↗

PubMed2004

Failure of radioiodine treatment in Graves' disease intentionally caused by a patient: suspected Munchausen syndrome.

We experienced a case with Graves' disease in which radioiodine treatment failed probably because of intentional spitting out of capsules of radioactive iodide. Chemical analysis of the substances collected from the trash in the treatment room demonstrated that its profile was the same as that of the capsules for radioiodine administration. Measurement of the iodine concentrations in a blood sample obtained at 24 h after the administration of radioiodine indicated that the patient showed iodine excess. These findings suggest that this may be a case of Munchausen syndrome.

Adult↗