Hemosiderosis due to excessive intake of iron

Summary A ten-year-old boy presenting with lymphadenopathy and hepatomegaly was found to have hemosiderosis on a lymphnode biopsy. Investigations revealed that he had ingested excessive amounts of iron leading to hemosiderosis. Other causative factors were excluded. After omission of further iron ingestion, the child improved. From the Department of Pediatrics, All India Institute of Medical Sciences, New Delhi 1–6.     

Non-ideality in vinyl polymerisation, 2. Free-radical polymerisation of styrene with azoisobutyronitrile

Polymerisation of styrene in benzene initiated by azoisobutyronitrile (AIBN) was carried out at 60°C covering a wide range of concentrations of both monomer and initiator. It is found that the monomer concentration has only little effect on the characteristic constant of primary radical termination, k_prt/(k_ik_p). This is explained on the basis of the fact that the secondary dissociation of the initial primary radicals occurs very quickly (ca. 10^?11 s), thus allowing no chance of competition for the initiation process. This is in sharp contrast to the secondary dissociation of the benzoyloxyl radical which has a much longer life-time (ca. 10^?9 s). However, it is found that the polymerisation constant 2f_kk_dk/k_t is dependent on monomer concentration and increases with the latter. The characteristic constant has also been determined at 40, 50, 70, and 80°C and the energy of activation corresponding to the initiation process obtained therefrom is about 66kJ/mol. This is appreciably higher than the value generally assumed (E_i≈E_p = 32,6kJ/mol) and could not be explained on the basis of experimental error. E_i is moreover very near to the value obtained for benzoyl peroxide initiated polymerisation of styrene determined earlier. Thus it seems that the initiation and propagation processes involve different activation energies and not the same as has hitherto been assumed.     

Orbital tuberculoma extending into the cranium

Orbital tuberculoma is not uncommon in the developing countries, but intracranial extension of orbital tuberculoma is extremely rare. Our case, a 14-year-old girl, presented with proptosis and progressive painless diminution of vision eventually leading to loss of vision. MRI showed a mass with peripheral enhancement of contrast, separate from the optic nerve and extending into the cranium through the optic foramen. Early decompression and chemotherapy resulted in marked visual recovery. Histopathology of the excised lesion confirmed tuberculosis. The case is reported to highlight both the rare presentation as well as remarkable visual recovery in a patient with orbital tuberculosis.