A mistake in the computer program performing the power law fit of the numerical computation of the hadron attenuation ratio R M has been detected. The mistake affects all fits which include the Xe nucleus. Below we present corrected results for table 2 and Figs. 8-10.Based on the corrected calculation we revise our conclusion in ref. [1]. The A 2/3 power law for 1 − R M in the absorption model remains also after including the Xe nucleus in the (c,α) fit.

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Purpose: Polychromatic cholesterol crystals of the anterior chamber are an interesting and unusual finding. This paper examines the different pathogenetic mechanisms leading to the formation of these clinically detectable anterior chamber crystals. Methods:Three aetiologically different cases which exhibited polychromatic crystals in the anterior chamber were reviewed. Aqueous samples were examined by wet field microscopy in all cases and additionally by electron microscopy in one of these. One enucleated globe was available for histopathology.Results: Typical highly refringent cholesterol crystals were identified in the aqueous of all cases. In the first case, the cholesterol crystals developed following the breakdown of vitreous and anterior chamber haemorrhage. In the second case, the cholesterol appeared to derive from the subretinal fluid of a chronic total retinal detachment in the absence of any intraocular haemorrhage. The cholesterol crystals of the final case resulted from phacolysis and were associated with a marked neutrophil response and the presence of proteinaceous crystals consistent with the crystallins. Conclusion:Anterior chamber cholesterolosis is a secondary phenomenon that always occurs as a result of an ocular disease process. Although the prognosis is dismal for chronically diseased eyes displaying cholesterol crystals in the anterior chamber, the prognosis for eyes with phacolysis may be excellent.

Oxygen consumption of preimplantation and early postimplantation mouse embryos has been measured using a novel noninvasive ultramicrofluorescence technique, based on an oil-soluble, nontoxic quaternary benzoid compound pyrene, whose fluorescence is quenched in the presence of oxygen. Pyruvate and glucose consumption, lactate production, and glycogen formation from glucose were also measured. Preimplantation mouse embryos of the strain CBA/Ca x C57BL/6 were cultured in groups of 10-30 in 2 microliters of modified M2 medium containing 1 mmol l-1 glucose, 0 mmol l-1 lactate, and 0.33 mmol l-1 pyruvate, for between 4-6 hr. Day 6.5 and 7.5 embryos were cultured singly in 40 microliters M2 medium for between 2-3 hr. Oxygen consumption was detected at all stages of development, including, for the first time, in the early postimplantation embryo. Consumption remained relatively constant from zygote to morula stages before increasing in the blastocyst and day 6.5-7.5 stages. When expressed as QO2 (microliters/mg dry weight/hr), oxygen consumption was relatively constant from the one-cell to morula stages before increasing sharply at the blastocyst stage and declining to preblastocyst levels on days 6.5 and 7.5. Pyruvate was consumed during preimplantation stages, with glucose uptake undetectable until the blastocyst stage. Glucose was the main substrate consumed by the 6.5 and 7.5 day embryo. The proportions of glucose accounted for by lactate appearance were 81%, 86%, and 119% at blastocyst, day 6.5, and day 7.5 stages, respectively. The equivalent figures for glucose incorporated into glycogen were 10.36%, 0.21%, and 0.19%, respectively. The data are consistent with a switch from a metabolism dependent on aerobic respiration during early preimplantation stages to one dependent on both oxidative phosphorylation and aerobic glycolysis at the blastocyst stage, a pattern which is maintained on days 6.5 and 7.5. Our technique for measuring oxygen consumption may have diagnostic potential for selecting viable embryos for transfer following assisted conception techniques in man and domestic animals.

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