High-dose busulfan, melphalan, thiotepa and peripheral blood stem cell infusion for the treatment of metastatic breast cancer

The purpose of this study was to determine the outcome of patients with metastatic breast cancer treated with high-dose busulfan (Bu), melphalan (Mel) and thiotepa (TT) followed by peripheral blood stem cell (PBSC) infusion. Fifty-one patients with chemotherapy refractory (n = 32) or responsive (n = 19) metastatic breast cancer received Bu (12 mg/kg), Mel (100 mg/m2) and TT (500 mg/m2) followed by PBSC collected after chemotherapy and growth factor (n = 43) or growth factor alone (n = 8). The 100 day treatment-related mortality was 8% including one death from cytomegalovirus pneumonia, one from aspiration pneumonia and two from regimen-related toxicity (RRT). Seven of 28 refractory (25%) and 5/7 (71%) responsive patients with evaluable disease achieved a complete response of all measurable disease or all soft tissue disease with at least improvement in bone lesions (PR*). Fifteen of 51 patients (29%) are alive and progression-free a median of 423 days (range 353-934) after treatment, 5/32 (16%) with refractory disease and 10/19 (53%) with responsive disease. The probabilities of progression-free survival (PFS) at 1.5 years for the patients with refractory (n = 32) and responsive (n = 19) disease were 0.24 and 0.53, respectively. These preliminary data suggest that high-dose Bu/Mel/TT has significant activity in patients with advanced breast cancer and may be superior to some previously published regimens.     

Assembly and analysis of conical models for the HIV-1 core

The genome of the human immunodeficiency virus (HIV) is packaged within an unusual conical core particle located at the center of the infectious virion. The core is composed of a complex of the NC (nucleocapsid) protein and genomic RNA, surrounded by a shell of the CA (capsid) protein. A method was developed for assembling cones in vitro using pure recombinant HIV-1 CA-NC fusion proteins and RNA templates. These synthetic cores are capped at both ends and appear similar in size and morphology to authentic viral cores. It is proposed that both viral and synthetic cores are organized on conical hexagonal lattices, which by Euler's theorem requires quantization of their cone angles. Electron microscopic analyses revealed that the cone angles of synthetic cores were indeed quantized into the five allowed angles. The viral core and most synthetic cones exhibited cone angles of approximately 19 degrees (the narrowest of the allowed angles). These observations suggest that the core of HIV is organized on the principles of a fullerene cone, in analogy to structures recently observed for elemental carbon.     

Iron overload in the rat pancreas following portacaval shunting and dietary iron supplementation

Reproduction of pancreatic iron overload in an animal model has been difficult to achieve primarily because of the first-pass extraction of iron by the liver. We hypothesized that portacaval shunting would avoid this hepatic phenomenon and increase pancreatic iron deposition. An end-to-side portacaval shunt was surgically created in male Sprague-Dawley rats, and they were subsequently fed a carbonyl iron-supplemented diet for 17 weeks. This resulted in marked iron accumulation in the pancreas (1621 +/- 188 micrograms/g) compared to minimal deposition in sham-operated rats fed the same diet (138 +/- 53 micrograms/g). Iron deposition in the acinar and centroacinar cells was confirmed histologically by Gomori staining, as well as by ultrastructural examination. Iron overloading was associated with enhanced oxidative stress evidenced by a twofold increase in the levels of glutathione disulfide and thiobarbituric acid-reactive substances. Also, adducts of proteins with malondialdehyde and 4-hydroxynonenal were demonstrated in acinar and ductal cells. Other apparent consequences of iron overload were a 50% reduction in pancreatic amylase content and a decrease in pancreatic protein concentration. These hypotrophic changes were associated with a reduced mass of zymogen granules in the acinar cells noted histologically. Our results show that a combination of portacaval shunting and carbonyl iron feeding achieve pancreatic iron overload and support the role of oxidative stress in the pathogenesis of iron-induced damage in the pancreas.     

Stereoisomers of 3-(2,3-dihydrobenzofuran-2-yl)quinuclidine: preparation and muscarinic receptor affinities

The four stereoisomers of the antimuscarinic 3-(2,3-dihydrobenzofuran-2-yl)quinuclidine have been prepared by a method involving chromatographic separation of the racemic diastereoisomers as borane complexes. The relative and absolute configurations of the stereoisomers were determined by X-ray crystallographic methods. The crystal structure of (2'R,3R)-3-(2,3-dihydrobenzofuran-2-yl)quinuclidine.HCl.H2O contains two independent molecules with different conformations of both the quinuclidine moiety and the dihydrofuran ring.     

Genomic amplification of a decoy receptor for Fas ligand in lung and colon cancer

Fas ligand (FasL) is produced by activated T cells and natural killer cells and it induces apoptosis (programmed cell death) in target cells through the death receptor Fas/Apol/CD95. One important role of FasL and Fas is to mediate immune-cytotoxic killing of cells that are potentially harmful to the organism, such as virus-infected or tumour cells. Here we report the discovery of a soluble decoy receptor, termed decoy receptor 3 (DcR3), that binds to FasL and inhibits FasL-induced apoptosis. The DcR3 gene was amplified in about half of 35 primary lung and colon tumours studied, and DcR3 messenger RNA was expressed in malignant tissue. Thus, certain tumours may escape FasL-dependent immune-cytotoxic attack by expressing a decoy receptor that blocks FasL.     

Different expression patterns of MMP-2 and MMP-9 in breast cancer

The role of nitric oxide (NO) in activation of cGMP is well established. It has been proposed that the ratio of cAMP to cGMP may be important in the regulation of preimplantation embryonic growth and differentiation. Therefore, we determined the ability of murine preimplantation embryos to produce NO. In addition, NO as an endogenous smooth muscle relaxant and vasodilator is a candidate for involvement in embryo implantation because this process requires increased vascular permeability and uterine quiescence at the sites of blastocyst apposition. Nitrite assays, an indirect measure of NO production, indicate that preimplantation murine embryos produce NO. This production was reversibly inhibited by culture of embryos in medium containing a nonspecific NO synthase (NOS) inhibitor (NG-nitro-L-arginine). Additionally, inhibition of normal development was observed in embryos cultured with NOS inhibitor. NO levels increased in culture medium when ovariectomized progesterone-treated animals were exposed to estrogen for 1 h in utero. Such hormonal treatment induces implantation. These data indicate that NO levels are regulated by estrogen and may be important in regulation of implantation. In addition, these data demonstrate for the first time that NO production appears to be required for normal embryonic development.