Mai Johnson

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The early androgen-dependent (AD) phase of prostate cancer is dependent on the androgen receptor (AR). However, it is unclear whether AR is fully functional in recurrent prostate cancer after androgen withdrawal. To address this issue we interrogated AR signaling in AD and recurrent prostate cancer xenografts using molecular imaging, chromatin(More)
Gene expression-based imaging coupled to gene therapy will permit the prediction of therapeutic outcome. A significant challenge for successful gene therapy is to achieve a high-level of specific gene expression; however, tissue-specific promoters are weak. We postulate that if the weak activity of tissue-specific promoters can be amplified to the levels of(More)
PURPOSE A highly augmented, prostate-specific two-step transcriptional amplification (TSTA) method was developed with the ultimate goal of delivering an effective and safe gene-based treatment to prostate cancer patients. Because very limited treatment options are available for recurrent hormone refractory prostate cancer (HRPC), it is imperative to assess(More)
The greatest challenge in cancer treatment is to achieve the highest levels of specificity and efficacy. Cancer gene therapy could be designed specifically to express therapeutic genes to induce cancer cell destruction. Cancer-specific promoters are useful tools to accomplish targeted expression; however, high levels of gene expression are needed to achieve(More)
Imaging in medicine has been classically based on the anatomical description of organs. In the past 15 years, new imaging techniques based on gene expression that characterize a pathological process have been developed. Molecular imaging is the use of such molecules to image cell-specific characteristics. Here, we review recent advances in molecular(More)
Studies finding an increased maximal rate of Na-Li countertransport in red blood cells from persons with essential hypertension and their normotensive offspring have raised the possibility that Na-Li countertransport may serve as a marker for the genetic predisposition to hypertension. We studied Na-Li countertransport in 238 randomly selected blood donors(More)
Cancer gene therapy based on tissue-restricted expression of cytotoxic gene should achieve superior therapeutic index over an unrestricted method. This study compared the therapeutic effects of a highly augmented, prostate-specific gene expression method to a strong constitutive promoter-driven approach. Molecular imaging was coupled to gene therapy to(More)
Tumor-specific adenoviral vectors comprise a fruitful gene-based diagnostic imaging and therapy research area for advanced stage of cancer, including metastatic disease. However, clinical translation of viral vectors has encountered considerable obstacles, largely due to host immune responses against the virus. Here, we explored the utilization of an(More)
RATIONALE AIT-082 (Neotrofin), a hypoxanthine derivative, has been shown to improve memory in both animals and humans. In animals, adrenal hormones modulate the efficacy of many memory-enhancing compounds, including piracetam and tacrine (Cognex). OBJECTIVE To investigate the role of adrenal hormones in the memory-enhancing action of AIT-082. METHODS(More)
UNLABELLED Because of its high selectivity and specificity for the imaging reporter probe 9-(4-(18)F-fluoro-3-[hydroxymethyl]butyl)guanine ((18)F-FHBG), the herpes simplex virus type 1 thymidine kinase (HSV1-tk) variant sr39tk is actively being studied as a PET reporter gene. We recently demonstrated the capability of using a prostate-specific(More)