Using arginase and hydroxyproline as biochemical markers, the yields and homogeneity of separated epithelial and stromal tissues from surgically removed benign hyperplastic prostate glands have been assessed. On the basis of these markers, about 30% of epithelial and 95% of stromal tissues were recovered. Dehydroepiandrosterone sulphate sulphatase activity was found predominantly in the epithelium, whereas testosterone 5alpha-reductase activity was predominantly in the stroma.

The dynamics of uptake and metabolism in vitro of androgens by normal and hyperplastic human prostate glands was studied by means of a new experimental design proposed by Gurpide & Welch (1969). Prostate slices were perfused with a medium containing [(3)H]testosterone and [(14)C]androstenedione, or 5alpha-dihydro-[(3)H]testosterone and [(14)C]testosterone. The entry into the slices, the irreversible metabolism, the conversion between the compounds and the tissue retention or ;uptake' of the steroids were measured at the steady state. A similar portion of the three androgens entered the tissue and was irreversibly metabolized. Conversion of testosterone into 5alpha-dihydrotestosterone was much greater than the interconversion of testosterone and androstenedione. The prostate slices retained 5alpha-dihydrotestosterone at a concentration three times that in the medium, whereas testosterone and androstenedione were retained to a smaller extent. At a steroid concentration of 0.11mumol/l in the medium, the various parameters did not differ significantly in experiments performed with slices from normal and hyperplastic glands. When the steroid concentration in the medium was increased tenfold, however, a difference between normal and hyperplastic glands was evident. The normal glands increased the uptake and metabolism proportionally to the elevation of the steroid concentration in the medium. In the hyperplastic glands the entry and metabolism lagged behind the increase in steroid supply, whereas the tissue uptake became disproportionately high. The possible causes of this finding are discussed.

BY A. C. BROWNIE AND J. K. GRANT ' cyclophorase' system (Green, Loomis & Auerbach, 1948). 'Cyclophorase' preparations, however, are not cytoplasmically homogeneous (Harman, 1950). Credit for showing that 1 1l,-hydroxylating enzymes are associated with adrenal-cell particles which by their method of preparation were mainly

Background Veledimex (VDX)-regulatable interleukin-12 (IL-12) gene therapy in recurrent glioblastoma (rGBM) was reported to show tumor infiltration of CD8 + T cells, encouraging survival, but also up-regulation of immune checkpoint signaling, providing the rationale for a combination trial with immune checkpoint inhibition. Methods An open-label, multi-institutional, dose-escalation phase 1 trial in rGBM subjects (NCT03636477) accrued 21 subjects in 3 dose-escalating cohorts: 1- neo-adjuvant then ongoing nivolumab (1mg/kg) and VDX (10 mg) (n= 3); 2- neo-adjuvant then ongoing nivolumab (3 mg/kg) and VDX (10 mg) (n=3); and 3- neo-adjuvant then ongoing nivolumab (3 mg/kg) and VDX (20 mg) (n=15). Nivolumab was administered 7 (+/- 3) days before resection of the rGBM followed by peritumoral injection of IL-12 gene therapy. VDX was administered 3 hours before and then for 14 days after surgery. Nivolumab was administered every two weeks after surgery. Results Toxicities of the combination were comparable to IL-12 gene monotherapy and were predictable, dose-related and reversible upon withholding doses of VDX and/or nivolumab. VDX plasma pharmacokinetics demonstrate a dose-response relationship with effective brain tumor tissue VDX penetration and production of IL-12. IL-12 levels in serum peaked in all subjects at about Day 3 after surgery. Tumor IFNγ increased in post treatment biopsies. Median overall survival (mOS) for VDX 10 mg with nivolumab was 16.9 months and for all subjects was 9.8 months. Conclusion The safety of this combination immunotherapy was established and has led to an ongoing phase 2 clinical trial of immune checkpoint blockade with controlled IL-12 gene therapy (NCT04006119).

tric oxide (NO) and serotonin (5-HT) are two neurotransmitters with important roles in neuromodulation and synaptic plasticity. There is substantial evidence for a morphological and functional overlap between these two neurotransmitter systems, in particular the modulation of 5-HT function by NO. Here we demonstrate for the first time the modulation of an identified serotonergic synapse by NO using the synapse between the cerebral giant cell (CGC) and the B4 neuron within the feeding network of the pond snail Lymnaea stagnalis as a model system. Simultaneous electrophysiological recordings from the pre-and postsynaptic neurons show that blocking endogenous NO production in the intact nervous system significantly reduces the B4 response to CGC activity. The blocking effect is frequency dependent and is strongest at low CGC frequencies. Conversely, bath application of the NO donor DEA/NONOate significantly enhances the CGC-B4 synapse. The modulation of the CGC-B4 synapse is mediated by the soluble guanylate cyclase (sGC)/cGMP pathway as demonstrated by the effects of the sGC antagonist 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). NO modulation of the CGC-B4 synapse can be mimicked in cell culture, where application of 5-HT puffs to isolated B4 neurons simulates synaptic 5-HT release. Bath application of diethylamine NONOate (DEA/NONOate) enhances the 5-HT induced response in the isolated B4 neuron. However, the cell culture experiment provided no evidence for endogenous NO production in either the CGC or B4 neuron suggesting that NO is produced by an alternative source. Thus we conclude that NO modulates the serotonergic CGC-B4 synapse by enhancing the postsynaptic 5-HT response.