TC99M-sestamibi scintigraphy as an imaging procedure in the preoperative evaluation of hyper-parathyroidism: a comparison with other imaging modalities

The present study was a prospective clinical study conducted over 4 years from 1996 till 1999 inclusive at KFSH-Kingdom Saudi Arabia to investigate the utility of Tc99m-sestamibi scintigraphy as an imaging tool in the preoperative localization of abnormal glands in cases with hyperparathyroidism. Comparison was also made between this procedure and other imaging procedures in terms of sensitivity and specificity with emphasis on the surgical success and postoperative cure rate. The study included 25 patients, 21 had primary hyper-parathyroidism and 3 had a secondary disease due to associated chronic renal failure. Eighteen were females and 7 were males with a mean age of 44 +/- 28 and a range of 16 to76 years. The mean serum calcium level of the whole group was high [2.81 +/- 0.29] ranging between 2.57 to 3.45 mmol/L while mean serum phosphate level was low 1.62 +/- 0.72 and range of 0.41 to 3.21 mmol/L. The serum parathormon level was also high, it ranges between 8.6 to 34.3 pmol/L with a mean value of 19.8 +/- 10.8. Preoperative imaging evaluation was carried out by scintigraphic detection of pathological parathyroid glands using Tc-sestamibi as a radiotracer for all the patients together with US, CT, MRI and TI/Tc subtraction imaging procedures. All the patients were considered for surgical treatment and confirmation of scans findings was obtained. Tc99m-sestamibi scintigraphy correctly localized 2o out of 21 adenomas with a sensitivity of 96% markedly higher than that obtained with other Imaging techniques [US- 76%, CT- 62%, MRI- 81% and TI/Tc-subtraction scintigraphy 72%]. Tc99m-sestamibi and MRI were the only procedures able to diagnose two of the 3 cases identified surgically as hyperplasia, whereas Tc99m-sestamibi was the only technique able to detect the case with ectopic mediastinal gland with significant higher specificity than other procedures which was reflected on the time and success of surgical treatment. In addition, the smallest abnormal gland in diameter [0.8 cm] and weight [195 mg] were only picked up by Tc99m-sestamibi scintigraphy while missed by other techniques. Surgery was successful in all cases as assessed by normalization of the serum calcium and phosphate levels and serum parathormon level as well. In patients with hyperparathyroidism, Tc-sestamibi scintigraphy may be used as a single imaging technique as it showed a high sensitivity and specificity in the preoperative localization of pathological parathyroid especially the ectopic glands. The benefit of proper preoperative localization of the glands has no doubt a great impact on the surgical success and postoperative cure rate

Effect of acute zinc administration on essential metal levels in liver, kidney, lung and heart of the male Egyptian toad Bufo regularis

To compare the organ injuries by Zn2+, a concentration of 48 mg Zn/kg body weight represented by LD50 was administered intramuscularly to the male Egyptian toad Bufo regularis. Median lethal concentration values [LD50] were 68, 62, 54 and 48 mg Zn/kg body weight for 24, 48, 72 and 96 hr, respectively. The changes in the concentration of six essential metals [Zn, Fe, Cu, Ca, Mg and Mn] were determined in liver, kidney, heart and lung of the male Egyptian toad Bufo regularis. Marked alterations in hepatic metal levels [increases of Zn, Cu and Ca] accompanied by a decrease in Fe content were observed. Renal Zn and Cu concentrations were increased, while renal magnesium was decreased. A significant depletion in Mg content was observed in the heart of the treated toad, while Mn content was increased in the lung of the treated one

Effect of panretinal photocoagulation on contrast sensitivity in eyes with high-risk proliferative diabetic retinopathy

The purpose of this study was to evaluate the changes occurring in contrast sensitivity in eyes of diabetics with high-risk proliferative diabetic retinopathy receiving scatter laser panretinal photocoagulation. Thirty eyes of 30 diabetic patients showing high-risk proliferative diabetic retinopathy both by colored fundus photography and fluorescein angiography had their contrast sensitivity measured before and after scatter panretinal argon green laser photocoagulation to detect any significant changes related to laser application in such eyes. Contrast sensitivity curves were shown to be lower than normal in both pre- and post-laser conditions with post- treatment curves having higher values and reaching statistical significance only at higher spatial frequencies [P 0.000]. Panretinal laser photocoagulation, in addition of having a considerable effect in preventing visual loss in eyes with high-risk proliferative diabetic retinopathy, has also a demonstrable effect in improving contrast sensitivity, especially at higher spatial frequencies