Rapid one-step modified technique in the evaluation of thyroglobulin by the immunoradiometric assay (IRMA) for monitoring differentiated thyroid carcinoma patients.

Objective: The aim of this study was to develop a modified one-step technique for measuring serum thyroglobulin (Tg), which is currently used as a tumor marker for differentiated thyroid carcinoma (DTC) by using the immunoradiometric assay (IRMA) of the THYROGLOBULINE IRMA kit as compared with the standard method. Methods: The surplus serum specimens from 111 DTC patients who had been treated and followed up at the Division of Nuclear Medicine, Department of Radiology and 105 healthy donors at the Department of Transfusion Medicine, Faculty of Medicine, Siriraj Hospital were included. The technique for serum Tg measurement was optimized from the two-step IRMA standard kits to the one-step modified method. Results: The one-step modified technique results in a decrease of turnaround time (TAT) from two days of both one-step and two-step gold standard kits to only two hours. The optimal volume of 125I - TgAb was found to be the same that of the kit’s technique. The optimal time for incubation was decreased from overnight at 17-18°C in the standard method to 90 minutes in a shaking water bath at 37°C. The analytical and functional sensitivities of the modified technique were 0.28 and 1.0 ng/ml, respectively. The coefficients of variation (%CV) of both intra-assay and inter-assay precision were 0.87-4.80% and 2.87-9.75%, respectively. The accuracies of the recovery test and dilution test were 92.74-101.82% and 101.27-109.16%, respectively. No cross-reaction presented between the anti-thyroglobulin antibodies and thyroid analogue compounds. The assays working range of Tg concentration under 10% CV of precision profile was 1.59-500 ng/ml. The correlation coefficient (r) between the results of the modified technique and the two-step standard method were excellent: r = 0.99; y = 1.349x-2.421; P < 0.001; n = 111. The reference range of Tg concentration among the euthyroid healthy subjects was 0.37-20.32 ng/ml (5th -95th percentile). Conclusion: The modified technique is simple, rapid, sensitive and reliable for monitoring the serum Tg level in DTC patients not only under stimulation but also during suppression therapy.

Rapid detection of iodine in iodised salt and iodised water essential in a program of iodine deficiency disorders control.

To determine and develop rapid on-site testing of iodine in salt and water samples and its use as field methods for monitoring and evaluation of the Iodine Deficiency Disorders (IDD) program. Methods: In order to monitor iodine in salt, the single bottle technique is recommended, utilizing SHMP (May & Baker), tapioca flour, KI and sodium azide. Secondly, to monitor iodine in water, the double bottle technique is employed and this utilizes 3N HCl as a substitute for SHMP to acidify flour, KI and sodium azide. Results: In salt, it is not positive until the colour starts to change from brown to black. In water, when it is positive reaching beyond an optimum level at 100-200 mg of iodine per litre, the colour starts to appear as faint blue and becomes darker blue as concentration of iodine increased. Discussion: Statistically, Spearman rank correlation co-efficient and the prediction method showed approximation of the two methods in estimation of iodine levels, indicating the interchangeability of the eyesight and it can be used in screening in place of the spectrophotometer. Conclusion: These techniques are cheap, simple and effective. This allows the monitoring kit to be beneficial and easy to use. These methods are ordinary and natural, and thus, in harmory with Thai culture and customs.

Treatment of hepatocellular carcinoma by injection of iodine*131-labelled lipiodol into the hepatic artery.

The therapeutic efficacy iodine*131-labelled Lipiodol was studies in the treatment of hepatocellular carcinoma (HCC). The results of the treatment were evaluated for four aspects: size of the tumour; serum alphafetoprotein level ; the quality of the patient’s life;and the survival rate. The hepatocellular carcinoma was diagnosed by evidence of mass in the liver using either computed tomography or ultrasonography with tissue biopsy and/or a high level of alphafetoprotein of more than 500 U. Twenty patients were randomized into two groups for comparison. The patients in group A were treated by intrahepatic injection of iodine*131-labelled Lipiodol 60 miliCuries(mCi). The patients in group B were treated by intra-hepatic injection of a mixture of Lipiodol and chemotherapeutic agents, mitomicin c 20 mg. and 5-fluoracil 500 mg., followed by selective hepatic artery embolisation of small pieces of gelatin sponge (gelfoam). Both groups were evaluated by computed tomography (CT) and the possible repeat of treatment protocol after two months. There were no serious side-effects or major complications in either group of patients. The patients’ conditions worsened by 40 percent in both groups. The tomours’ sizes remained unchanged by 50 percent in both groups. The serum alphafetoprotein levels had increased by 40 percent in group A, and remained unchanged by 50 percent in group B. The survival rates at one and two years in group A were 20 and 20 percent, and in group B there were 30 and 0 percent, respectively. Satisfactory results were obtained in the treatment of small HCC, size less than 5 cm. with intra-hepatic artery injection of iodine*131-labelled Lipiodol. In large HCC (>10cm) no response by the tumour was seen in either group. This was the first study of this type performed in Thailand.

Preparation of seed iodized oil.

Synthesis of iodized oil: iodized oil was prepared after modified T. Ma’s method as follows : safflower, Soya bean, corn, rice bran or peanut oils reacted with dried hydroids acid (HI) which was powdered by hydrolysis of phosphorus trioxide (PI3), a reaction between red phosphorus and iodine. The resulting products were esterified with sodium ethoxide. The end product was identified as iodized oil by nuclear magnetic resonance spectrometers (NMR), infrared spectrophotometers (IR) and gas chromatography (GC). The preparation was kept in a cool place under light tight condition. The products were proved to be stable and free of any toxicity. The preparative scale production of the iodized oil for endemic goiter control is under way.

Radionuclide lymphoscintigraphy in hodgkin’s disease with Ic 99m – dextran a case report.

This case report presents the study of lymphoscintigraphy in complement with Tc 99m – Dextran in Hodgkin’s disease. The results comfirmed good correlation with both CT and lymphangiography.

Thallium scan in patients with coronary artery disease: A preliminary report.

Exercise thallium studies of forty-eight patients performed to evaluate coronary artery disease were reviewed. The results of the exercise thallium studies were compared to those of exercise ECG tests done simultaneously, and coronary arteriography performed 2 weeks to more than one year after. The sensitivity and specificity of exercise thallium study were 81.8 and 100 percent whereas those of exercise ECG test were 81.8 and 50 percent, respectively. Sites of abnormalities detected by coronary arteriography correlated with 77.8 percent of thallium studies, but 44.4 percent of exercise ECG tests. The results of exercise thallium studies and exercise ECG tests agreed in 81.3 percent of patients. Exercise thallium study is sensitive and specific and has good correlation with coronary arteriography. It is useful in detection of coronary artery disease, evaluation of extent of the diseased myocardium as well as potency of coronary artery bypass graft.

Qualitative enzyme-linked immunosorbent assay for ferritin as a screening procedure for Iron deficiency and iron overload.

The qualitative ELISA technique for the determination of serum ferritin was developed and performed in parallel with the IRMA. There is a high degree of association between the two methods. The IRMA method is most sensitive in detecting depletion of iron stores in female group and group of schoolchildren which may have iron is clinically useful in screening for evaluation of body iron status in any population.