4-Hydroxy-f-androstene-3,17-dione (4-OH-A) when tested at various concentrations was found to inhibit markedly the conversion of 4-andorstene-3,17-dione to estrogens inhuman placental and rat ovarian microsomes. To obtain evidence that estrogen biosynthesis could also be reduced in vivo with 4-OH-A, rats were treated sc at a dose level of 50 mg/kg body weight. After 3 h the ovarian veins were cannulated and blood collected. Estradiol concentrations in the plasma were reduced by 80% compared to control values during the proestrous surge and on Day 4 of pregnancy. 4-OH-A was also found to be effective in controlling estrogen-dependent reproductive and neoplastic processes. In rats treated from Day 2-7 of pregnancy, implantation of fertilized ova was completely prevented in some rats, while in others either implantation was delayed or the development of implants was retarded. 4-OH-A treatment of rats having estrogen-dependent breast tumors induced by 7,12-dimethylbenz(a)anthracene caused 80% of the tumors to regress significantly in 4 weeks of treatment; 42% of these regressed completely.

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SYNOPSISThe random liquid crystalline copolymer poly (4,4'-biphenylene azelate) -co-(2-methyl-1,4-phenylene azelate) , synthesized by condensation polymerization, was found to be soluble in chloroform and methylene chloride. DSC, rheology, and optical microscopy indicated that this LCP broadly melts at ca. 160°C to a weakly birefringent melt that becomes isotropic at approximately 180°C. DSC and optical microscopy of blends with poly(methy1 methacrylate) (PMMA) at wLcp = 0.06,0.16,0.34, and 0.69, indicated little compatibility between the polymers at middle compositions. Dynamic and steady shear flow rheological measurements, using cone/plate geometry, showed the PMMA-rich ( 6 wt % LCP) and LCPrich ( 69 wt % LCP) blends to be essentially homogeneous, and dominated by the properties of the major component. However, at 16 wt % and 34 w t %, the resulting phase separation led to lower dynamic moduli (than either LCP or PMMA separately), and increased shear thinning. This behavior supports the notion that the LCP acts as a lubricant by promoting the flow of the non-LCP. The results reported in this article show that these rheological effects, which were previously observed in blends of insoluble, rigid LCPs and engineering thermoplastics, still exist with a much less rodlike LCP mixed with a commodity polymer. However, these studies 3-6 typically involve insoluble, rigid " V e~t r a " -t y p e~-~ LCPs, with high transition temperatures ( >200°C). The non-LCP component, therefore, had to be an engineering thermoplastic, such as a polysulfone3 or p~l y a m i d e~,~; alternatively, the LCP polymer could be blended in