Browsing by keyword "Nitriles"
Now showing items 1-4 of 4
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A review of cardiac imaging with sestamibi and teboroximeOverall, it is clear that the two new technetium-labeled compounds can provide diagnostic myocardial perfusion imaging both at stress (exercise and pharmacologic) and rest, but they have very different mechanisms of transport in comparison to each other and to thallium. Therefore, new imaging protocols will need to be developed and refined by practical experience as the use of these agents expands. Further investigative work needs to be done to optimize protocols and computer processing of images. In addition, special clinical situations will become associated with the use of these new compounds. Nuclear cardiology will continue to advance during this time of great changes and challenges if informational exchange on these topics continues to flourish and critical clinical trials are completed.
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Bicalutamide inhibits androgen-mediated adhesion of prostate cancer cells exposed to ionizing radiationBACKGROUND: Cell adhesion plays an important role in proliferation, metastasis, and tumor growth and may represent a potential vulnerability in treatment of prostate cancer patients. Bicalutamide (Casodex) has been used as an anti-androgen agent for prostate cancer patients during hormone ablation therapy. This study focuses on the effect of Bicalutamide on cell adhesion to fibronectin (FN) in prostate cancer cells. METHODS: Androgen-dependent LNCaP prostate cancer cells were stimulated with androgen before being irradiated with doses of 0, 5, 10, or 15 Gy. Cell adhesion to fibronectin was then measured to ascertain androgen's role in integrin mediated prostate cancer cell adhesion. Flow cytometry was used to analyze surface expression of integrin subtypes in LNCaP cells. RESULTS: LNCaP cell adhesion to FN was significantly increased by stimulation with androgen when treated with 10 or 15 Gy ionizing radiations but not at 0 or 5 Gy. This increase was inhibited by treatment with Bicalutamide. LNCaP cells exposed to high dose radiation showed an increased expression of alpha(V) and beta(1) integrins in response to androgen treatment while Bicalutamide abolished this effect. CONCLUSIONS: Our data show that Bicalutamide inhibits the effect of androgen on cell adhesion to FN through changes of integrin subtypes in cells given high dose radiation. This suggests new molecular targets and possible treatment strategies for prostate cancer patients to improve the outcome during hormone ablation therapy and radiation therapy.
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Nitrous oxide promotes hyperhomocysteinemia in levodopa treated ratsBACKGROUND: This study investigated whether brief exposure to nitrous oxide (N(2)O) exacerbates levodopa-induced hyperhomocysteinemia, and if co-treatment with folate or entacapone could reduce total plasma homocysteine (tHcy) levels. METHODS: Male Wistar rats (N=9 per group) were randomly treated with vehicle/N(2)O (GROUP 1), levodopa/nitrogen (group 2), levodopa/N(2)O (group 3), levodopa/N(2)O+folate (group 4), or levodopa/N(2)O+entacapone (group 5). tHcy was measured at 12 min, 4, 8, and 12 h after anesthesia. RESULTS AND CONCLUSION: The combination of N(2)O-exposure and levodopa treatment significantly increased tHcy in rats. This hyperhomocysteinemia could be prevented by entacapone but not folate co-administration.
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Selection for androgen receptor mutations in prostate cancers treated with androgen antagonistThe role of androgen receptor (AR) mutations in androgen-independent prostate cancer (PCa) was determined by examining AR transcripts and genes from a large series of bone marrow metastases. Mutations were found in 5 of 16 patients who received combined androgen blockade with the AR antagonist flutamide, and these mutant ARs were strongly stimulated by flutamide. In contrast, the single mutant AR found among 17 patients treated with androgen ablation monotherapy was not flutamide stimulated. Patients with flutamide-stimulated AR mutations responded to subsequent treatment with bicalutamide, an AR antagonist that blocks the mutant ARs. These findings demonstrate that AR mutations occur in response to strong selective pressure from flutamide treatment.
