Lythgoe, M. F.; Anderson, P. J.; Surma, M.; Todd-Pokropek, A.; Orton, M.; Gordon, I. Author Information

Lythgoe, M.; Anderson, P.; Gordon, I.; Surma, M.; Orton, M.; Pokropek, A. Todd Author Information

The presence of focal renal damage dictates different management of a child with urinary tract infection (UTI) compared with children who have normal kidneys. Technetium-99m-dimercaptosuccinic (DMSA) has a high sensitivity in the detection of a focal defect, and allows estimation of differential function. The introduction of 99mTc-MAG3 with high renal extraction suggests that this may be useful in children with UTI but its role remains speculative. Fifty-nine children with previous UTI underwent both 99mTc-DMSA and MAG3 within 4 wk of each other. Differential function and assessment of the images were undertaken. There is close correlation (R2 = 0.97) between the differential function. Analysis of the 99mTc-DMSA and functional MAG3 images showed that the functional image had a specificity of 88% and a sensitivity of 88% in the detection of a focal parenchymal defect. Technetium-99m-MAG3 in the clinical setting of a child with UTl allows accurate assessment of differential function and a high probability of detecting a focal renal abnormality.

Dynamic renal scintigraphy using technetium-99m mercaptoacetylglycylglycylglycine (MAG3) has been described in adults, and clearance values have been established using multiple plasma samples. This study of renal clearance has compared two fundamentally different gamma camera techniques (both of which require a single blood sample) with the multiple blood sampling technique in children (n = 30). Results show that a 40-min dynamic 99mTc-MAG3 renal scintigram coupled with a single plasma sample will allow analysis of the data so that clearance values, which are similar to those from multiple plasma samples, may be calculated. The curve generated from the cardiac region of interest (ROI) provided clearances values that had a high correlation coefficient (0.939-0.951) compared to the multiple-plasma sample technique immaterial of the timing of the blood sample. The renal uptake method of clearance had a lower correlation coefficient (0.89-0.92), which varied with the timing of the blood sample compared to the multiple-plasma sampling technique. This study has demonstrated that an extended gamma camera acquisition coupled with a single-plasma sample may be used for quantitative renal function studies using 99mTc-MAG3.

Studies of the geographic variability of Ascochyta rabiei were done using chickpea cultivars of differing susceptibility under uniform growth room conditions. The pathogenicity of certain isolates particularly those from the Indian subcontinent and Western Asia was greater than that of most isolates collected in the Western Mediterranean. Several cultivars already deployed in breeding programmes showed stable resistance to the fungus, others with intermediate levels of resistance were less stable when exposed to a high disease pressure developed by the repeated passaging of isolates through them. In general differences in pathogenicity were attributed to variations in aggressiveness shown by the constant ranking of the cultivars used. Sporulation may not be linked to pathogenicity and significant statistical interactions with reversals in cultivar rankings suggests this to be an area for further study. Resistance to A. rabiei seems to be polygenic or at least oligogenic. In conditions of prolonged disease pressure some barriers to infection and/or spoulation may be overcome by pathogenic adaptation.