Biomedical subjects
Yutaka Mori
Publications and source records attributed to Yutaka Mori.
A case of ganglioneuroma in which 131I-6beta-iodomethyl-19-norcholest-5(10)-en-3beta-ol scintigraphy showed high uptake in the adrenal gland leading to a misdiagnosis.
We experienced a case in which 131I-6beta-iodomethyl-19-norcholest-5(10)-en-3beta-ol (131I-adosterol) scintigraphy showed high uptake in the right adrenal gland. We diagnosed functional cortical adenoma because of the finding of 131I-adosterol scintigraphy. However, no positive findings for the existence of cortical adenoma were obtained in other examinations and we performed right adrenalectomy. Unexpectedly, pathological finding showed the right adrenal gland was occupied with a large ganglioneuroma. This is an instructive case in which 131I-adosterol scintigraphy showed abnormal high uptake in the adrenal gland, in spite of the fact that the adrenal gland was occupied by a tumor derived from adrenal medulla.
Effects of diazepam on 125I-iomazenil-benzodiazepine receptor binding and epileptic seizures in the El mouse.
OBJECTIVE: To investigate changes in free benzodiazepine receptor density in response to repeated, long-term administration of diazepam in epilepsy, we assessed 125I-iomazenil (125I-IMZ) binding in a mouse model. METHODS: El mice were divided into two groups of 12 mice each which received either no diazepam (E1(D[-]) group) or 2 mg/kg of diazepam per week (El(D[+]) group). Nine ddY mice were used as a control. Once each week from the age of 5 to 19 weeks, the El mice received stimulation to produce epileptic seizures 20 minutes after receiving intraperitoneal injections. At 20 weeks of age, a total dose of 0.37 MBq of 125I-IMZ was injected in all mice and their brains were rapidly removed 3 hours later. The incidence of epileptic seizures at the age of 19 weeks and the autoradiograms of the brain were compared. RESULTS: The incidence of epileptic seizures in response to weekly stimulation was significantly lower in the E1(D[+]) group than in the E1(D[-]) group (p < 0.001). The percent injected doses of 125I-IMZ per gram of tissue in the cortex, hippocampus and amygdala were significantly lower in the E1(D[+]) group than in the E1(D[-]) group (p < 0.05). CONCLUSION: The results suggest that diazepam binds competitively to 125I-IMZ as an agonist to free benzodiazepine receptor sites in the cortex, hippocampus and amygdala and shows anticonvulsant effect in E1 mice.
Effects of pioglitazone vs glibenclamide on postprandial increases in glucose and triglyceride levels and on oxidative stress in Japanese patients with type 2 diabetes.
To investigate the relationship between insulin resistance, postprandial hyperglycemia, postprandial hyperlipidemia, and oxidative stress in type 2 diabetes, changes in postprandial glucose, triglyceride, and nitrotyrosine levels vs baseline after diet loading were examined in type 2 diabetic patients given pioglitazone (PG) or glibenclamide (GB). Twenty-four outpatients with type 2 diabetes treated with oral PG for 6 mo (BMI, 26.3 +/- 0.9; HbA1c, 8.2 +/- 0.2%) and 10 type 2 diabetic patients treated with GB (BMI, 27.4 +/- 1.6; HbA1c, 8.1 +/- 0.2%) at our institutions were compared. These patients were given meal tolerance tests (MTT; each consisting of energy 400 kcal, protein 8.7 g, fat 22.4 g, carbohydrate 41 g) before and 6 mo after administration of either agent. PG produced a significant decrease in FPG, HbA1c, HOMA-R, and TG levels in the subjects compared to baseline. In contrast, GB significantly decreased FPG and HbA1c levels, while not affecting HOMA-R and TG values. While PG produced a significant increase in LPL, HDL-cholesterol, and adiponectin levels, GB did not affect these values. At MTT 6 mo after PG administration, insulin levels before and 4 h after MTT, free fatty acid (FFA) levels 1, 2, and 4 h after MTT, glucose, TG, and RLP-TG levels before and 1, 2, 4, and 6 h after MTT were significantly decreased compared to baseline. At MTT 6 mo after GB administration, while a significant decrease in fasting and 2 h, postprandial glucose values compared to baseline MTT levels was observed, fasting and postprandial TG and RLP-TG levels remained unchanged compared to baseline. After 6 mo of PG and GB administration, serum nitrotyrosine levels before and after MTT were significantly decreased compared to baseline in both groups, while the decrease in nitrotyrosine levels before and after MTT was more marked in the subjects given PG. Our study results suggest that PG suppresses increases in postprandial glucose and TG levels, and improves insulin resistance; and, in addition, that PG may have a favorable impact on oxidative stress in type 2 diabetic patients.
Differences in the pathology of the metabolic syndrome with or without visceral fat accumulation: a study in pre-diabetic Japanese middle-aged men.
To elucidate the role of visceral fat accumulation in the metabolic syndrome, differences in the pathology of the metabolic syndrome with or without visceral fat accumulation were investigated. A total of 472 prediabetic Japanese men (mean age, 47.5 +/- 7.2 yr) with impaired fasting glycemia (IFG) levels of 110-125 mg/dL were eligible for participation in the study. The study subjects were divided into the following four groups, and intergroup comparisons were made: group I without visceral fat area [VFA] > or = 100 cm2 but presenting with fewer than two other risk factors (i.e., TG > or =150 mg/dL, HDL-C < 40 mg/dL, BP > or = 130/ > or = 85 mmHg, or FPG > or = 110 mg/dL) (n = 231); group II without VFA of > or = 100 cm2 but presenting with three or more other risk factors (n = 57); group III with VFA of > or = 100 cm2 accompanied by FPG 110 mg/dL alone (n = 27); and group IV with VFA > or =100 cm2 and two or more other risk factors (n = 157). The prevalence of patients who had three or more risk factors with or without VFA > or = 100 cm2 was 45.3% (214 out of 472 patients), while that of those with VFA > or = 100 cm2 who had two or more other risk factors was 33% (157 out of 472 patients). Group II had significantly higher VFA values than group I (p < 0.05), and group IV had significantly higher VFA values than group II (p < 0.001). While no significant differences in HOMA-R values were seen between groups I and II, these values were significantly higher in group IV compared to groups I and II (p < 0.001 and p < 0.05, respectively). Furthermore, group IV showed significantly higher 2-h insulin levels after glucose loading compared to group I (p < 0.001). While no significant differences were seen between groups II and IV, insulin levels tended to be higher in group IV. Adiponectin levels showed an incremental fall in VFA from group I through groups II and III to group IV. Groups III and IV showed significantly lower adiponectin levels compared to group I (p < 0.05, p < 0.001, respectively); and group IV showed significantly lower adiponectin levels than group II (p < 0.05). A logistic regression analysis using VFA, TG and HDL-C, and BP as explanatory variables showed that the relative risk for high HOMAR values were 2.65 (p < 0.001) for patients with VFA > or =100 cm2; 1.64 (p < 0.05) for those with TG > or = 150 mg/dL and HDL < 40 mg/dL; and 1.79 (p < 0.01) for those with BP > or = 130/ > or = 85 mmHg. These findings demonstrate that the degree of insulin resistance and the risk of arteriosclerosis vary depending on whether or not the metabolic syndrome accompanied by a clustering of risk factors has visceral fat accumulation as an underlying pathology, strongly suggesting a crucial role for visceral fat accumulation in the metabolic syndrome.
Japanese IGT subjects with high insulin response are far more frequently associated with the metabolic syndrome than those with low insulin response.
Impaired glucose tolerance (IGT) represents a prediabetic state positioned somewhere between normal glucose tolerance and diabetes, which is also assumed to make individuals in this state highly susceptible to atherosclerotic disease. IGT also accounts for a highly heterogeneous population, with the condition varying from individual to individual. In this study, we stratified subjects with IGT by their insulin response and compare the pathology of IGT when it is associated with high or low insulin response to gain insight into the diverse pathology of IGT. Of the male corporate employees who underwent 75 g OGTT at the corporation's healthcare center, 150 individuals diagnosed with IGT (isolated IGT, combined IGT and IFG) comprised our study subjects. The study subjects were stratified into four quartiles by percentile AUC for insulin, and those in the 25th or less percentile were defined as the low insulin response group (n = 37), vs those in the 76th or greater percentile defined as the high insulin response group (n = 38), and these groups were compared. There was no significant difference observed between the two groups in regard to post-OGTT glucose response and area under the glucose curve. However, the high insulin response group was associated with higher BMI, subcutanesous fat area, uric acid levels, HOMA-beta cell values, and delta insulin/delta glucose (30 min) than the low insulin response group. The number of risk factors for the metabolic syndrome detected (as defined by the ATPIII diagnostic criteria) per subject was 2.84 +/- 0.17 and 2.08 +/- 0.20, respectively, in the high insulin response group and in the low insulin response group, with the number significantly (p < 0.05) higher in the high insulin response group. Furthermore, the incidence of the metabolic syndrome as defined by the ATPIII diagnostic criteria was 63.2% (24/38) in the high insulin response group vs 32.4% (12/27) in the low insulin response group, with the incidence significantly (p < 0.01) higher in the high insulin response group. Likewise, the incidence of the metabolic syndrome as defined by the Japanese diagnostic criteria was found to be significantly (p < 0.05) higher in the high insulin response group at 50% (19/38) compared to 27.0% (10/37) in the low insulin response group. Our study findings suggest that IGT subjects with high insulin response and those with low insulin response vary greatly in regard to the number of atherosclerotic risk factors complicated and the frequency with which they are associated with the metabolic syndrome. It is also shown in middle-aged Japanese males that of the two forms of IGT, IGT with high insulin response is more closely linked to the pathogenesis of atherosclerotic cardiovascular disease.
Role of hypoadiponectinemia in the metabolic syndrome and its association with post-glucose challenge hyper-free fatty acidemia: a study in prediabetic Japanese males.
We investigated the role of hypoadiponectinemia in the metabolic syndrome (MS), as well as its association with post-glucose challenge hyper-free fatty acidemia in the clinical setting. The study subjects comprised 177 corporate employees shown to have a fasting plasma glucose (FPG) level of 125 mg/dL or less in a 75 g OGTT in the corporation's healthcare center. When divided into those who met the Japanese criteria for the metabolic syndrome (MS group; n = 45) and those who did not (Non-MS group; n = 132), the MS group was shown to have significantly lower adiponectin levels than the Non-MS group, and tended to show higher high-sensitivity C-reactive protein (CRP) values than the Non-MS group, while not achieving statistical significance. The MS group showed higher baseline glucose levels; higher baseline, 30-, 60-, and 120-min post-challenge insulin levels; higher 30-, 60-, and 120-min post-challenge free fatty acid levels than the Non-MS group. Additionally, there was a significant, negative correlation between adiponectin levels, area under the free fatty acid curve, and area under the insulin curve at OGTT (r = -0.24, p < 0.01; r = -0.21, p < 0.01, respectively). When the patients were divided by adiponectin level into four groups to examine the number of risk factors for MS detected per patient and the incidence of MS, the lower the adiponectin level, the more risk factors were found per patient, with 68% of patients with an adiponectin level of less than 4 microg/mL found to have MS. In those with an adiponectin level of less than 4 microg/mL, BMI values, uric acid levels, HOMA-R values, and the number of risk factors for MS involved per patient were shown to be higher than in those with an adiponectin level of 4 microg/mL or greater. Furthermore, the following risk factors for MS were more frequently found in those with an adiponectin level of less than 4 microg/mL than in those with an adiponectin level of 4 microg/mL or greater: VFA > or = 100 cm2 (OR 12.8, p < 0.001); TG > or = 150 mg/dL (OR 3.2, p < 0.05); HDLC < 40 mg/dL (OR 1.9, p = 0.29); BP > or = 130/85 mmHg (OR 2.2, p = 0.15); and FPG > or = 110 mg/dL (OR 1.9, p = 0.29). Again, the incidence of MS (OR 7.6, p < 0.001) by the ATPIII criteria, as well as that by the Japanese criteria (OR 8.6, p < 0.001), was found to be higher in those with an adiponectin level of less than 4 microg/mL than in those with an adiponectin level of 4 microg/mL or greater. Our study results suggest that adiponectin is closely associated with the multiple risk factors that go to make up the MS, suggesting a role for hypoadiponectinemia as a surrogate marker for the MS and further appear to suggest that post-challenge hyper-free fatty acidemia may account in part for hypoadiponectinemia in the MS.
Smoking as a risk factor for visceral fat accumulation in Japanese men.
Epidemiological and clinical studies on the lifestyle-related obesity have identified smoking, physical activity and alcohol intake as risk factors for obesity. However, no consensus has yet been reached on the effect of smoking on visceral adiposity. This study was designed to assess whether smoking is associated with the accumulation of visceral fat, glucose and lipid metabolism. The subjects were 450 males aged from 24 to 68 years old, who were examined at the health control center in the regular health check conducted by their company. A self-administered questionnaire was used to ascertain smoking status, daily physical activity and alcohol drinking. The number of Brinkman index as an index for smoking status was positively related to being visceral fat area (VFA). In smokers whose Brinkman index was higher, the percent of subjects with abnormal body mass index, VFA, triglyceride, high density lipoprotein-cholesterol, atherosclerotic index, plasma glucose, immunoreactive insulin, or homeostasis model assessment of insulin resistance (HOMA-IR) was higher than that in non-smokers. When evaluated in terms of age-adjusted odds ratios for incidence of a VFA of 100 cm(2) or greater, alcohol drinking was associated with the highest odds ratio. Smoking, physical inactivity and excessive alcohol drinking were associated with visceral adiposity, and smoking affected glucose and lipid metabolism. In conclusions, these findings suggest that smoking is a risk factor for visceral fat accumulation and deterioration of glucose and lipid metabolism.
New body mass index criteria of central obesity for male Japanese.
In recent years, intra-abdominal visceral fat leads to obesity-related complications. A simple indicator that reflects the mass of visceral fat is also needed to enable practical screening of patients. The present study was designed to establish new body mass index (BMI) criteria of central obesity for male Japanese. The subjects were 516 men aged from 19 to 80 years old who were examined at the physical examination center in the regular health check conducted by their company. Correlations between visceral fat area (VFA) or subcutaneous fat area (SFA) and BMI in the subjects were investigated. Receiver Operating Characteristics (ROC) curve was used to find out the optimal cut-off values of BMI to predict central obesity. We compared the percentile ranks corresponding to VFA of 100 cm2, BMI of 25 kg/m2 and new BMI criteria to check to see whether the present BMI criteria classify correctly Japanese men as central obesity. Further evidence for the effectiveness of BMI for VFA is needed. The correlation coefficient between VFA or SFA and BMI was 0.59 or 0.67, respectively. At the cut-off for BMI that maximized sensitivity and specificity for predicting central obesity was 24 kg/m2. Moreover, the percentile value corresponding to VFA of 100 cm2, BMI of 24 kg/m2, and BMI of 25 kg/m2 was the 53, 50 and 61 percentile, respectively. It is necessary to lower a cut-off point for central obesity from BMI of 25 kg/m2 to 24 kg/m2.
Effect of intramuscular fat difference on glucose and insulin reaction in oral glucose tolerance test.
We investigated the relationship between insulin reaction and glycemic control in a 75-g oral glucose tolerance test of lipid in the paraspinal muscles using computed tomography (CT). The subjects were 79 males aged from 30 to 60 years old whose body mass index (BMI) was 25 or more. Those who had already been diagnosed as having type-2 diabetes mellitus in a regular health check and whose fasting plasma glucose was 126 mg/dl or more were excluded. Abdominal CT scan at the umbilicus level was conducted, and the visceral fat area (VFA) and subcutaneous fat area (SFA) were obtained. As an index of the relative lipid content within muscle, the mean skeletal muscle attenuation (MA) was determined. The age-adjusted odds ratio caused by the MA size for each variable was calculated. Compared with those with smaller intramuscular fat volume, those with larger volume demonstrated 8.75 times higher BMI, 3.73 times higher VFA and 2.88 times higher HOMA-IR. A significant difference was observed between the groups with high and low lipid content in the muscle in the values of Age, BMI, VFA, Fasting immunoreactive insulin (IRI) and HOMA-IR. It was suggested that MA of the paraspinal muscles reflected fat content, and this regional body composition parameter was closely related to insulin secretion response and glycemic control.
Benzodiazepine effect of (125)I-iomazenil-benzodiazepine receptor binding and serum corticosterone level in a rat model.
To test the change in free or unoccupied benzodiazepine receptor (BZR) density in response to diazepam, we investigated (125)I-iomazenil ((125)I-IMZ) binding and serum corticosterone levels in a rat model. Wistar male rats, which received psychological stress using a communication box for 5 days, were divided into two groups according to the amount of administered diazepam: no diazepam [D (0)] group and 10 mg/kg per day [D (10)] group of 12 rats each. The standardized uptake value (SUV) of (125)I-IMZ of the D (10) group were significantly lower (P < .05) than those of the D (0) group in the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus. The serum corticosterone level ratio in the D (10) group was significantly lower than that in the D (0) group (P < .05). From the change in serum corticosterone levels, diazepam attenuated the psychological stress produced by the physical stress to animals in adjacent compartments. From the reduced binding of (125)I-IMZ, it is clear that diazepam competed with endogenous ligand for the free BZR sites, and the frontal, parietal and temporal cortices, globus pallidus, hippocampus, amygdala and hypothalamus are important areas in which (125)I-IMZ binding is strongly affected by administration of diazepam.
Dietary diacylglycerol reduces postprandial hyperlipidemia and ameliorates glucose intolerance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.
OBJECTIVE: The aim of the present study was to determine the effects of dietary diacylglycerol (DG) on the metabolism of lipids and glucose in type II diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS: In experiment 1, the rats were orally administered 10 mL/kg of a triacylglycerol (TG) or DG emulsion (15% [w/v] oil), and the subsequent changes in the serum lipid levels were compared. In experiment 2, the rats were fed diets containing 15% DG or TG oil. After 22 weeks, the serum levels of lipids, glucose, and cytokines were determined. In addition, an oral glucose tolerance test (OGTT) was performed on the rats. RESULTS: Administration of an oral fat load caused marked hypertriglyceridemia with a peak at 2 h. Oral DG loading reduced the serum TG increase; the difference between the groups was significant at 4 and 6 h (P < 0.05). Diacylglycerol also markedly reduced the serum free fatty acid concentration increase due to the fat load. After 22 weeks of feeding, dietary DG reduced serum TG levels in the non-fasting state. Moreover, an OGTT revealed enhanced glucose disposal in the DG-fed rats compared with the TG-fed rats. Serum levels of adiponectin, an important insulin-sensitizing adipocytokine, were higher in the DG-fed rats than in the TG-fed rats (P < 0.05). In addition, DG-feeding reduced serum levels of C-reactive protein, a cardiovascular risk factor (P < 0.05). CONCLUSION: These results suggested that dietary DG improves lipid metabolism and glucose tolerance, and retards the progress of diabetes mellitus in OLETF rats.
Suppression of body weight gain preserves acute insulin response to glucose in the portal vein of spontaneously type 2 diabetic rats with visceral obesity.
The age-related changes in acute insulin response after glucose loading and the influence of suppression of body weight gain were investigated by using blood samples from portal and peripheral veins. We placed indwelling catheters in the portal vein of 12- and 24- wk-old Otsuka Long-Evans Tokushima fatty (OLETF) rats (n = 8, 12), and age-matched control Long-Evans Tokushima Otsuka (LETO) rats (n = 8, 6). To suppress the body weight gain, 6 out of 12 OLETF rats were fed chow containing 50 ppm voglibose (VOG) from 8 until 24 wk of age. After fasting for 17 h, rats underwent 1 g/kg oral glucose tolerance test (OGTT). Peripheral glucose levels after glucose loading were significantly higher in 12- and 24-wk-old OLETF rats than in the age-matched LETO rats. Values for delta insulin 15 min/delta glucose 15 min (delta I15 min/delta G15 min) in portal blood were 0.029 +/- 0.011 and 0.009 +/- 0.009 (12 wk of age) and 0.03 +/- 0.03 and -0.01 +/- 0.01 (24 wk of age) in the LETO rats and OLETF rats. At the age of 24 wk, the body weights in VOG-treated OLETF rats were significantly lower than those in the OLETF rats. And there was significantly greater acute insulin response to glucose in VOG-treated OLETF rats than in the OLETF rats. Acute insulin response to glucose decreased with advancing age and the suppression of body weight gain preserved the response in spontaneously type 2 diabetic rats with visceral fat obesity.
Association between postprandial remnant-like particle triglyceride (RLP-TG) levels and carotid intima-media thickness (IMT) in Japanese patients with type 2 diabetes: assessment by meal tolerance tests (MTT).
Our study evaluated the relationship between the pathologic changes associated with atherosclerosis, as primarily represented by postprandial remnant-like lipoproteins and carotid intima-media thickness (IMT), in type 2 diabetic patients. Meal tolerance tests (MTT) were performed in 68 patients with type 2 diabetes. The subjects were divided by pre-meal and 2-h postprandial triglyceride (TG) levels into the normotriglyceridemia (NTG) group; the postprandial hypertriglyceridemia (PHTG) group; and the fasting hypertriglyceridemia (FHTG) group. HOMA-R values were significantly higher in the FHTG group than in the NTG group, with the plasma pre-heparin LPL mass and serum adiponectin levels in the FHTG and PHTG groups significantly lower than in the NTG group. One- and two hour postprandial RLP-TG levels were significantly higher in the PHTG group than in the NTG group, while there was no significant difference in postprandial glucose levels between the two groups. The IMT values were significantly higher in both the FHTG and PHTG groups than in the NTG group. Logistics regression analysis of the 1- and 2-h RLP-TG values using IMT as an induced variable showed the odds ratio for high IMT values to be 5.17 (p < 0.05) for the 1-h RLP-TG values and 3.01 (p = 0.105) for the 2-h RLP-TG values. Our study results suggest that delayed TG metabolism leading to the retention of remnants in type 2 diabetic patients appears to be closely associated with atherosclerosis, and that postprandial hyperlipidemia is an independent risk factor for the early onset of atherosclerosis.
Adenosine A1 receptor mapping of the human brain by PET with 8-dicyclopropylmethyl-1-11C-methyl-3-propylxanthine.
UNLABELLED: Adenosine is an endogenous modulator of synaptic functions in the central nervous system. To investigate the physiologic and pathologic roles of the adenosine receptors in the human brain, PET is a powerful in vivo technique. In this study, we quantitatively evaluated the distribution of a major subtype A(1) adenosine receptor in the human brain by PET with a newly developed radioligand, 8-dicyclopropylmethyl-1-(11)C-methyl-3-propylxanthine ((11)C-MPDX). METHODS: In 5 healthy volunteers, after PET measurement of the regional cerebral blood flow (rCBF) with (15)O-H(2)O, a 60-min PET scan with (11)C-MPDX was performed. The distribution volume (DV) of (11)C-MPDX was quantitatively evaluated by Logan's graphical analysis. RESULTS: (11)C-MPDX was taken up at a high level, reaching a peak at 2-2.5 min, followed by a rapid decrease. The unchanged form of (11)C-MPDX in plasma was 75% at 60 min after injection. The DV of (11)C-MPDX was large in the striatum and thalamus, moderate in the cerebral cortices and pons, and small in the cerebellum. The distribution pattern of (11)C-MPDX in the brain was coincident with that of adenosine A(1) receptors in vitro, reported previously, but discretely different from that of rCBF. CONCLUSION: (11)C-MPDX PET has the potential for mapping adenosine A(1) receptors in the human brain.
[Guidelines for radio-iodine (131I) therapy in Graves' disease and thyroid cancer].
Radio-iodine (131I) therapy has been using in Graves' disease and well differentiated thyroid cancer. The rules of control in the discharge from radio-isotope hospital were notified in 1999 in Japan. Guideline of the 131I therapy in Graves' disease and thyroid cancer were prepared by sub-group of Japanese Society of Nuclear Medicine.
The usefulness of radio-guided surgery in secondary hyperparathyroidism.
Recent reports have shown that radio-guided surgery with an intraoperative gamma probe (IGP) is useful for identifying parathyroid adenomas. The aim of this study was to evaluate the usefulness of IGP mapping in patients with secondary hyperparathyroidism. Seven patients with secondary hyperparathyroidism underwent technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) scintigraphy immediately before undergoing surgical resection of all parathyroid tissues. We compared the sensitivity of Tc-99m MIBI scintigraphy alone with that of the combination of Tc-99m MIBI scintigraphy and IGP mapping. The sensitivity of the combination of Tc-99m MIBI scintigraphy and IGP mapping was 100% (28 of 28 lesions) and was significantly higher than that of Tc-99m MIBI scintigraphy alone (71.4%, 20 of 28 lesions). The combination of the Tc-99m MIBI scintigraphy and IGP mapping has increased sensitivity for identifying parathyroid lesions during parathyroidectomy in patients with secondary hyperparathyroidism.
Usefulness of radio-guided surgery using technetium-99m methoxyisobutylisonitrile for primary and secondary hyperparathyroidism.
The efficacy of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI)-guided surgery for detecting abnormal parathyroid glands in patients with secondary hyperparathyroidism (2-HPT) was evaluated and compared with the results from the same examination in patients with primary hyperparathyroidism (1-HPT). The results were also compared with those found by ultrasonography (US) and preoperative 99mTc-MIBI scintigraphy was also made. At operation 99mTc-MIBI accumulated in 64 nodules of 15 cases of 2-HPT, and all of 60 parathyroid swellings were detected (true-positives 60, sensitivity 100%, accuracy 94%). In the cases of 1-HPT, 99mTc-MIBI revealed 11 hot nodules in 10 cases, and the evaluation was true-positive 10, sensitivity 100%, and accuracy 91%. US and preoperative 99mTc-MIBI scintigraphy in patients with 2-HPT had a sensitivity of 75% and 67% and an accuracy of 70% and 66%, respectively. The usefulness of 99mTc-MIBI-guided surgery for detecting abnormal parathyroid tissue in 2-HPT patients was similar to that in 1-HPT patients but was superior to US and preoperative 99mTc-MIBI scintigraphy. Intraoperative 9mTc-MIBI for patients with 2-HPT is effective and makes the surgery easier, especially when the parathyroid glands are ectopic or when a few glands are markedly enlarged but the other glands are atrophied.