Production logistics and radionuclidic purity aspects of 153Sm for radionuclide therapy.

153Sm, an attractive therapeutic radionuclide, was produced by neutron activation of both natural Sm2O3 and 98% enriched 152Sm2O3 targets. The production logistics and radionuclidic purity aspects of 153Sm obtained using both these targets are discussed with respect to the intended end use for metastatic bone pain palliation (MBPP) in terminal cancer patients and radiation synovectomy (RS) of medium size joints. The specific activity of 153Sm obtained was around 11 GBq x mg(-1) (approximately 300 mCi x mg(-1)) and 44 GBq x mg(-1) (approx. 1200 mCi x mg(-1)) from natural and enriched targets, respectively. The level of the long-lived radionuclidic impurity burden in 153Sm obtained from the natural Sm2O3 targets, namely, due to 154Eu (5 Bq x MBq(-1) 153Sm (5 nCi x mCi(-1) 153Sm)) and 155Eu (75 Bq x MBq(-1) 153Sm (75 nCi x mCi(-1) 153Sm)), appears low enough not to pose a problem, both in the palliative treatment of terminal cancer patients (at 1.85-2.22 GBq (50-60 mCi) dose) as well as in RS (at 74 MBq (2 mCi) dose). The 154Eu content in 153Sm from the enriched target was comparable, while, as expected, the level of 155Eu was nearly two orders of magnitude lower. There is a notable overall advantage of 153Sm over the use of 186Re, the other radionuclide of interest for the same purposes.

Stabilisation of [131I]meta-iodobenzylguanidine at room temperature as organic extract in ethyl acetate/chloroform.

A method of purification of [131I]mIBG (diagnostic dose) by solvent extraction and possibility of its stabilisation by storage in ethyl acetate and chloroform at up to 40 degrees C for not less than 14 days is described. In order to further enhance the utility of this finding, the organic extract was dispensed into vials and dried. Vials containing such dried residue of [131I]mIBG stored at up to 40 degrees C was also found to be stable for at least 10 days. The final product reconstituted as aqueous solution resulted in 90% recovery with 99% radiochemical purity as assessed by previously reported methods, as well as a relatively more rapid paper chromatography method standardised by us. These interesting findings promise simpler and economic packaging besides transport of diagnostic doses of [131I]mIBG.

Evaluation of radioiodination of meta-iodobenzylguanidine (MIBG) catalysed by in situ generated Cu(I) and directly added Cu(II).

A reliable method of labelling MIBG with 131I is reported. Radioiodination involved nucleophilic exchange reaction (160 degrees C, 30 min) catalysed by directly added Cu(II) or by Cu(I) generated in situ by addition of Na2S2O5 to CuSO4. An additional step of purification of the radiolabelled MIBG by anion exchange chromatography is recommended. The radiochemical (RC) yield was over 90%, while the typical RC purity of 131I-MIBG was not less than 98%. Higher labelling yield was achieved with Cu(I) than when using Cu(II), and with 125I (commercial product) than with 131I obtained by wet radiochemical processing method in-house. The purity and stability of MIBG-131I was confirmed by biodistribution studies in monkeys with 0.03% and 0.8% uptake in adrenals and myocardium, respectively. It is concluded that Cu(I) or Cu(II) catalysed radioiodination method is well suited for production of MIBG-131I.

Tuberculoma of orbit.

An interesting case of tuberculoma of the orbit, involving the whole of the eyeball with other orbital cavity structures, is being presented. This is very rarely seen in clinical practice.

Total central keratolysis.

Central keratolysis is a rare entity. An interesting case of unilateral central keratolysis in an aphakic patient is reported.

Role of Tromaril as anti-prostaglandin drug on blood aqueous barrier.

In this experimental work, it was observed that after anterior chamber paracentesis there was more effusion of protein into the anterior chamber. Pretreatment with aspirin/indomethacin and a new drug, enfenamic acid (Tromaril), decreased this trauma-induced increase in aqueous protein content. It was further observed that this inhibition was more marked with Tromaril pretreatment in comparison with other drugs. Prostaglandin-mediated disruption of blood aqueous barrier can also be decreased with Tromaril pretreatment. Tromaril, a prostaglandin synthetase inhibitor, may help us to control the reactions to surgical ocular trauma and other ocular inflammatory diseases.

Curcuma longa (Linn) drops in corneal wound healing.

In this study, an attempt has been made to evaluate the cortisone like inhibitory activity on healing of wounds of curcuma longa extracts-aqueous extract (2.8%) and alcoholic extract (1.125%) on the healing of superficial and penetrating corneal wounds in albino rabbits. It was observed that curcuma longa aqueous drops (a) definitely delayed healing of superficial corneal wounds (P less than 0.001), (b) delayed healing of penetrating corneal wounds also and markedly reduced the tensile strength of corneal wounds (P less than 0.02), when comparison was made with placebo and preservative drops.

Reduced fibrinolytic activity in aqueous humor of chronic simple glaucoma.

Fibrinolytic activity of aqueous humor was tested by the Astrup fibrin plate lysis technique in 7 patients who had chronic simple glaucoma and was compared with a control group of 7 patients with senile cataract. The plasminogen activator content of aqueous humour in glaucoma patients was remarkably reduced; it was not demonstrable in as many as six out of seven patients. The lysis zones in the control group ranged from 110 to 900 mm2 with an average of 423 mm2. The want of aqueous fibrinolytic activity may have a pathogenetic implication for glaucoma since deposition of fibrin in the angle of the eye to depressed fibrinolytic activity could increase resistance to aqueous flow.

Role of tromaril--a new anti-inflammatory drug in eye diseases.

In this clinical study, the role of enfenamic acid (Tromaril), a new anti-inflammatory and nonsteroidal drug, on various eye diseases such as trauma, on inflammatory diseases such as uveitis, and after cataract surgery was evaluated. The drug was administered to 30 patients (group A) while 29 patients (group B) were given a placebo. Twenty-one patients showed good response, and of these, 15 patients (76%) belonged to group A, to whom Tromaril had been administered. Of the patients who were given Tromaril, none showed any side effects in general. It can be concluded that Tromaril is a strong and effective anti-inflammatory drug for use in various eye diseases.

The effect of vitamin A and cortisone on ascorbic acid content in the aqueous humor.

Thus, it can be concluded from our observations that the effect of cortisone drops in reducing the concentration of ascorbic acid in the aqueous humor can be neutralized by simultaneous administration of vitamin A drops. This observation has an important clinical bearing, as ophthalmologists have hesitated to use cortisone locally for a long time for fear that it may either precipitate glaucoma or cataract (most probably because of the subsequent lowering of ascorbic acid concentration in the aqueous humor and lens). Our finding that with the administration of vitamin A drops along with cortisone drops there is no significant lowering of the ascorbic acid level in the aqueous humor indicates that one can use cortisone drops without being afraid of precipitating glaucoma or cataract.

Effects of vitamin A and cortisone on healing of corneal penetrating wounds.

The effect of the administration of vitamin A drops on neutralizing the inhibitory role of cortisone in penetrating corneal wound healing was studied on 24 albino rabbits (48 eyes). The rate of healing of the wound was determined by the fluorescein strain technique and the tensile strength of the affected cornea was determined on the 11th day after the wound was made. It was observed that in the group of eyes in which only cortisone in any form was administered, not only was the rate of healing delayed (with statistical significance) but there was also a statistically significant lowering of the tensile strength of the wound. However, in the eyes in which vitamin A was also administered simultaneously with cortisone, the rate of healing of the wound was enhanced and there was also a statistically significant increase in the tensile strength of wound. Therefore in this study it was confirmed that by simultaneous use of vitamin A drops, the inhibitory role of cortisone is neutralized even in penetrating corneal wounds.