Application of quantitative salt iodine analysis compared with the standard method.

Laboratory investigation of 50 iodated salt samples (from producers, households, markets etc) were studied at the Research Nuclear Medicine Building, Siriraj Hospital. Two methods for the determination of iodine in salt are herein described. The standard method as recommended by The Programme Against Micronutrient Malnutrition (PAMM) / The Micronutrient Initiative (MI)/ The International Council for Control of Iodine Deficiency Disorders (ICCIDD) was the iodometric titration method. The starch-KI salt iodine quantitative method was developed in our laboratory for validation purposes. This method is high in precision, accuracy, sensitivity as well as specificity. The coefficient of variation (%CV) for intra and inter assay was below 10. Iodine contents as low as 10 ppm, could be detected. The proposed starch-KI method offered some advantages: e.g. not complicated, easier to learn and easier to perform competently, could be applied for spot qualitative test and readily performed outside the laboratory. The results obtained by the starch-KI method correlated well with the standard method (y = 0.98x - 3.22, r = 0.99).

Metastatic follicular carcinoma of thyroid to pericardium.

A 62 year-old man presented with massive pericardial effusion and a thyroid nodule. One thousand ml of serosanguinous pericardial effusion was tapped and the cytology consistent with metastatic papillary carcinoma. Total thyroidectomy was done. The pathological report of the thyroid gland was follicular carcinoma, poorly differentiated with capsular and vascular invasion. The patient received a treatment of 150 mci I-131 without complications. The total body scan after I-131 treatment showed only residual thyroid tissue. There was no demonstrable abnormal uptake in other parts of the body. No significant reaccumulation of pericardial fluid occurred. The diagnosis was follicular carcinoma of the thyroid with pericardial metastasis. The patient was discharged from the hospital with an improved clinical status.

Thyroid scintigraphy in children with hypothyroidism: a five-year experience.

The presence or absence of thyroid glandular tissue demonstrated by thyroid scintigraphy is important for genetic and prognostic counseling and for acceleration of diagnosis in other affected siblings. Technetium-99m-pertechnetate thyroid scintigraphy was performed on 27 children with cretinism at the Division of Nuclear Medicine, Faculty of Medicine Siriraj Hospital during the 5-year period from June 1991. Based on scintigraphic findings, three main groups of thyroid localization were seen. Thirteen (48.1%) were athyrotic while 3 (11.1%) had an ectopic thyroid and 11 (40.8%) had gland in normal position. Perchlorate discharge test was performed in 8 children of the last group and the results were positive indicating an organification defect. Thyroid scintigraphy and perchlorate discharge test provided the useful information for diagnosis, follow-up, and prognosis in children with cretinism.

The evaluation of combined scintimammography and tumor markers in breast cancer patients.

BACKGROUND: Breast cancer is the second most common cancer in Thai women. Mammography is the method of choice for early detection but scintimammography (SMM) is sometimes helpful. Many tumor markers are important in the follow-up of treatment. MATERIALS AND METHODS: 47 breast cancer patients (36 for preoperative evaluation, others for postoperative investigation) were studied with SMM using 201Tl and/or 99mTc-MIBI and serum CEA and CA15-3. RESULTS: SMM could pick up breast cancer in 91.7% of the patients with intact breast masses and 2/2 cases of local recurrence. The uptake ratio tended to increased from stage 2A through 3B. Sensitivity of SMM to detect axillary node uptake was only 44.4%. SMM had no role in the evaluation of the postoperative period unless there was no evidence of palpable recurrent disease. No definite correlation between serum CEA and CA15-3 levels was observed. Elevated CA15-3 is a good indicator for recurrent and metastatic breast diseases and more specific than CEA in clinical correlations. CONCLUSIONS: SMM may be helpful when mammographic results are questionable. SMM can detect primary breast cancers and recurrent lesions that are palpable with high sensitivity. Increased tumor-uptake ratio and rising serum tumor markers, more often seen with elevated CA15-3 rather than CEA, could be useful for the prognosis of breast cancer patients. Even though CA15-3 is not reliable for the early detection of breast cancer, it is very helpful for monitoring therapeutic response since its level correlates with the clinical state better than CEA.

Dose-dependent inhibitory effect of phenolic compounds in foods on nonheme-iron absorption in men.

Nonheme-iron absorption from a typical Southeast Asian meal was studied to examine the effect of a common vegetable, Yod Kratin, which contains a considerable amount of iron-binding phenolic groups. Yod Kratin (leaves of the lead tree) is a very popular vegetable in Thailand. It is consumed at least once a week year round, sometimes every day, together with the main meal. With a common portion size of the vegetable (20 g), iron absorption was reduced by almost 90%. As little as 5 g inhibited iron absorption by 75%. Addition of ascorbic acid partly counteracted inhibition. Adding 100 mg ascorbic acid reduced inhibition of iron absorption from 5 g Yod Kratin by half and the inhibition from 10 g Yod Kratin by a quarter. The study illustrates the marked effect of iron-binding phenolic compounds on iron nutrition and, thus, the importance of acquiring knowledge of the content of such compounds in different foods.

Rice and iron absorption in man.

Several studies suggest that iron absorption is low from rice-based meals. Comparisons of the effect of rice starch and wheat starch on iron absorption showed that rice had no effect on absorption. Observed differences in effects on iron absorption between different batches of rice starch could be explained by differences in the phytate content. Phytate is always present in rice grains. The content varies markedly depending on the method of milling. In polished rice, the content of phytate-P varied between 11.5 and 66 mg/100 g rice (data from 45 rice mills in Thailand). The bioavailability of iron in a meal composed of meat, a vegetable and rice varied about threefold (22.1-7.5 per cent) depending on the different phytate content of the rice (4 levels between 30 and 175 mg phytate-P were studied). The inhibitory effect of the phytate in rice was overcome by adding different amounts of an ascorbic acid-rich vegetable (green collard) to the meals.

Reduced erythrocyte survival following clearance of malarial parasitaemia in Thai patients.

Erythrocyte survival times were measured in healthy Thai controls and in patients following clearance of asexual P. falciparum or P. vivax parasitaemia. In five controls the mean cell life (MCL) of compatible donor erythrocytes was 89.6 d (mean range 73-101 d) compared with a mean MCL of 56.8 d (range 30-66 d) for autologous erythrocytes in 12 falciparum patients. In one of these patients the survival curve was biphasic with a rapid loss of some labelled cells. The survival of compatible donor erythrocytes was also studied in 10 patients and two types of survival curve could be distinguished. In five patients the cells had a mean MCL of 64.4 d (range 42-90 d). In the others survival curves were curvilinear, suggesting a complex mechanism of cell clearance or the presence of more than one cell population. There was initially a more rapid rate of destruction. In P. vivax malaria the MCL of autologous erythrocytes in seven patients was a mean of 67.2 d (range 34-74 d) and that of compatible donor cells in six patients was 66.8 d (range 54-76 d). In all except one of these patients both autologous and donor cell survival curves could be fitted to straight lines. No increase in cell-bound IgG or C3 was evident in 12 patients tested. The differences between the mean MCL in all the groups of patients and the controls were statistically significant at the 5% level. This indicates an increased rate of erythrocyte destruction following clearance of P. falciparum or P. vivax parasites which is not antibody or complement mediated. The mechanism is unknown, but appears to be extrinsic to the erythrocytes themselves and may result from nonspecific activation of the reticuloendothelial function associated with the parasitic infection.

Iron absorption from some Asian meals containing contamination iron.

Iron absorption was measured from 12 Asian meals using the extrinsic tag method. Up to 50% of the nonheme iron in the meals did not exchange with the added inorganic radioiron tracer. The extent of isotopic exchange, the native iron and the "contamination" iron was measured using a recently developed in vitro method. The results imply that in measurements of iron absorption from meals, especially in developing countries, it is essential to consider the presence of contamination iron and its limited bioavailability.