Expression in non-lens tissues of an enzyme activity related to the 'lens-specific' protein, delta crystallin.

When chick embryo neutral retina (NR) cells are cultured for long periods in vitro, they undergo extensive transdifferentiation into lens and express the lens protein, delta crystallin. We now demonstrate that this process is accompanied by a change in the chromatin conformation of the delta-gene locus from DNAase1-resistant to DNAase1-sensitive in the nuclei of most cells. Transcripts hybridising to a delta probe are also much more prevalent among the in vitro transcription products from lens or transdifferentiated NR culture nuclei, as compared to nuclei from fresh NR tissue. Published evidence indicates that the chick delta 1 crystallin gene encodes the major structural protein of embryonic lens fibres, whereas the closely related delta 2 gene may encode the urea-cycle enzyme argininosuccinate lyase (ASL). Our present data lends further support to this view. Both immunodetectable delta-related protein(s) and ASL activity are present in fresh embryonic NR tissue, as well as in mouse and Rana liver, and in Rana lens. Our polyclonal anti-delta antibody also cross-reacts with a major constituent of commercial bovine ASL, of the same molecular size as chick delta crystallin. Immunoselection studies suggest that the ASL activity in chick embryonic NR is conferred mainly by the delta-related protein band. So-called 'ectopic' expression of delta crystallin in embryonic NR (and other tissues) may thus involve the delta 2/ASL gene, and could reflect some metabolic requirement for ASL activity.

Long-term assessment of 107 patients undergoing bladder neck incision.

The notes of 134 consecutive patients undergoing bladder neck incision (BNI) were analysed retrospectively. Details of pre-operative symptoms and the short-term results of the operation were studied, as well as the need for reoperation. Long-term results of the operation were not available in 100 patients and a questionnaire was sent to them asking for details of their present symptoms. This produced results on the long-term follow-up of 107 patients with a mean follow-up of 31 months (range 18-48); 86% of patients showed an improvement in symptoms in the short term whilst 68% maintained a subjective improvement in symptoms in the long term. Further surgery was required in 18 patients (13%). Possible reasons for this are discussed.

Hyponatraemia following transurethral resection of the prostate.

In a prospective study of 100 patients undergoing transurethral resection, changes in serum sodium were estimated during the per-operative and post-operative periods. The weight of prostate resected and the volume of irrigant fluid used influenced the changes in serum sodium. In 93 patients these changes were not statistically significant. In only seven patients were significant falls in serum sodium recorded, in one case to a level of 103 mmol/l. All seven exhibited the clinical features of the transurethral syndrome and there was one post-operative death which we attributed to it. The TUR syndrome undoubtedly exists and its incidence in this series was 7%. Its pathogenesis and clinical management are discussed.