New data on odd-parity autoionization in xenon have provided an opportunity to apply multichannel-quantum-defect theory (MQDT) to the J =0 spectra. This analysis complements the many studies of the J = 1 spectra. Nine bound and seven autoionizing levels were analyzed. The resulting DDT parameters are able to reproduce the measured energy levels with an rms error of 0.33 cm, and predictions of autoionization rates are in good agreement with observed linewidths.The position and width of the lowest J=0 autoionization resonance, the Ss'[ -, lo level, are predict-

In the pediatric age group, acute lymphocytic leukemia (ALL) may involve the testicles during complete remission of the disease in the marrow. We report a case of testicular involvement with ALL in an adult and review 11 cases of this phenomenon reported previously, to draw attention to the fact that it can occur at any age. Recognition of this fact is important, because testicular involvement may be the first manifestation of systemic relapse. The treatment of choice is irradiation to both testicles and combination chemotherapy.

BMP signalling is known to have a conserved function in development of the semicircular canal system of the vertebrate inner ear, but its regulation, target genes and effects on cell behaviour during otic morphogenesis are not fully understood. We have characterised the effects of mutations in the zebrafish gene bmper, which codes for a regulator of BMP signalling with both pro- and anti-BMP roles in different developmental contexts. The inner ears of bmper mutant embryos develop with truncations of the anterior and posterior semicircular canal ducts. To image the developing ear in live embryos, we have exploited a new transgenic line, Tg(smad6b:EGFP), which exhibits strong GFP expression in the otic epithelium. Morphometric analysis indicates defects in the bmper mutant ear from early stages of semicircular canal formation, correlating with a specific reduction in BMP signalling activity and specific loss of dlx5a expression in dorsal otic epithelium. Subsequent changes to cell shape occur at the truncation site and the dorsolateral septum. The bmper mutations that we describe are adult viable; truncation of the anterior and posterior semicircular canal ducts persists into adulthood. Our results argue against a major role for Bmper in specification of the pre-placodal region, induction of the otic placode, or development of the neural crest, processes in which Bmper function has previously been implicated. Instead, we conclude that a key requirement for Bmper function in the zebrafish is to promote BMP signalling during patterning and morphogenesis of the semicircular canal system.