Evaluation of voriconazole anti-Acanthamoeba polyphaga in vitro activity, rat cornea penetration and efficacy against experimental rat Acanthamoeba keratitis.

Background: Acanthamoeba keratitis (AK) is a sight-threatening infectious disease. Its effective and safe medical therapy remains highly debated. Recently, voriconazole, a monotriazole with noted in vitro activity against a large variety of fungi, has been successfully used both topically and systemically to treat human AK cases. Objectives: To measure anti-Acanthamoeba polyphaga in vitro activity, anti-rat AK efficiency and rat cornea penetration of eye-drop and oral voriconazole. Methods: A. polyphaga was maintained in axenic cultures. In vitro, amoebicidal and cysticidal activities of voriconazole were measured using an XTT assay. AK lesions of Sprague Dawley rats were scored from grade 0 to grade 3. For 21 days, from day 7 post-infection, voriconazole (1% solution) eye drops were instilled or voriconazole was administered by gavage (60 mg/kg/day). After killing, superficial corneal epithelium scrapings were cultured and analysed by PCR, and eye-globe histology was performed. Cornea and plasma concentrations were determined using 2D HPLC separation and tandem MS. Results: In vitro, voriconazole inhibited trophozoite proliferation with an IC50 value of 0.02 mg/L and an IC90 value of 2.86 mg/L; no cysticidal effect was found. In AK rats, eye drops reduced clinical worsening from day 7 to day 14 post-infection and oral voriconazole was not effective. Voriconazole cornea concentrations were directly dependent on the frequency of eye-drop instillations, which resulted in lower plasma concentrations, whilst oral voriconazole resulted in lower cornea concentrations. Conclusions: Present data underline the need for high-frequency eye-drop instillation regimens for efficient AK therapy.

Salvage radiotherapy after high-intensity focused ultrasound treatment for localized prostate cancer: feasibility, tolerance and efficacy.

BACKGROUND: The objective of this study is to evaluate the feasibility, tolerance and efficacy of salvage external beam radiotherapy (EBRT) in persistent or recurrent prostate cancer after failed high intensity focused ultrasound (HIFU) therapy. METHODS: We reviewed data on tolerance and oncologic outcomes for all patients with biopsy-proven locally recurrent or persistent prostate cancer who underwent salvage EBRT in our department between April 2004 and June 2008. Minimum follow-up for inclusion was 2 years. Failure with EBRT was defined as biochemical relapse (Phoenix definition) or introduction of androgen deprivation therapy (ADT). Gastrointestinal and urinary toxicity and urinary stress incontinence were scored at 12 and 24 months (Radiation Therapy Oncology Group and Ingelman Sundberg rating, respectively). RESULTS: The mean age of the patients was 68.8 years (range: 60-79). Mean prostate-specific antigen (PSA) before EBRT was 5.57 ng/mL (range: 2.5-14.8). Median follow-up was 36.5 ± 10.9 months (range: 24-54). No patient received adjunctive ADT. The EBRT course was well-tolerated and completed by all patients. The mean PSA nadir was 0.62 ng/mL (range: 0.03-2.4) and occurred after a median of 22 months (range: 12-36). One patient experienced biochemical failure and was prescribed ADT 30 months after EBRT. The disease-free survival rate was 83.3% at 36.5 months. There was no major EBRT-related toxicity at 12 or 24 months. CONCLUSIONS: Our early clinical results confirm the feasibility and good tolerance of salvage radiotherapy after HIFU failure. Oncological outcomes were promising. A prospective study with longer follow-up is needed to identify factors predictive of success for salvage EBRT therapy after HIFU failure.

Six years' experience with high-intensity focused ultrasonography for prostate cancer: oncological outcomes using the new 'Stuttgart' definition for biochemical failure.

OBJECTIVE: • To determine oncological outcomes after high-intensity focused ultrasonography (HIFU) treatment in patients with localized prostate cancer using a new, more accurate, definition ('Stuttgart' definition) of biochemical failure. PATIENTS AND METHODS: • We performed a retrospective review of all patients in our centre who received first-line treatment with a second-generation Ablatherm™ device (EDAP-TMS, Lyon, France). • Oncological failure was given either by biochemical failure (prostate-specific antigen, PSA, nadir plus 1.2 g/mL) (Stuttgart definition) or the start of salvage therapy because of a persistently positive biopsy after the HIFU procedure. • The 5-year biochemical-free survival rate and 5-year disease-free survival rate were calculated. RESULTS: • In total, 53 patients were included (mean age, 72.5 ± 4.5 years, range 60-79 years; 28 low risk and 25 intermediate risk). None had undergone previous hormonal therapy. Mean ±sd follow-up was 45.4 ± 15.5 months (range 16-71 years). Mean (range) pre-treatment PSA was 8.5 ± 4 (0.29-18) ng/mL. The median (range) PSA nadir value was 1 (0.01-14) ng/mL and occurred after a mean (range) of 5.09 (3-24) months. • Overall, 36 patients (67.9%) experienced oncological failure. • These included 33 cases (62.2%) of biochemical failure. A PSA nadir of ≤0.2, 0.21-1.0 and >1 ng/mL was reached in 20.8%, 30.2% and 49% of patients, respectively, and was associated with biochemical failure in 9.1%, 30.3% and 60.6%, respectively. • The 5-year biochemical-free survival rate and disease-free survival rate were 21.7% and 13.5%, respectively. In multivariate analysis, a PSA nadir of >1 ng/mL was significantly associated with a risk of biochemical and oncological failure (P= 0.002 and P < 0.001). • Oncological failure was not associated with any risk group. • No patient died from prostate cancer. CONCLUSIONS: • In our experience, Ablatherm™ treatment for clinically localized prostate cancer was associated with a high rate of biochemical failure as determined by the 'Stuttgart' definition, and did not achieve effective cancer control. • The PSA nadir value after HIFU treatment was a significant predictor of treatment failure.

Chemical inducers and transcriptional markers of oligodendrocyte differentiation.

Oligodendrocytes generate and maintain myelin, which is essential for axonal function and protection of the mammalian central nervous system. To advance our molecular understanding of differentiation by these cells, we screened libraries of pharmacologically active compounds and identified inducers of differentiation of Oli-neu, a stable cell line of mouse oligodendrocyte precursors (OPCs). We identified four broad classes of inducers, namely, forskolin/cAMP (protein kinase A activators), steroids (glucocorticoids and retinoic acid), ErbB2 inhibitors, and nucleoside analogs, and confirmed the activity of these compounds on rat primary oligodendrocyte precursors and mixed cortical cultures. We also analyzed transcriptional responses in the chemically induced mouse and rat OPC differentiation processes and compared these with earlier studies. We confirm the view that ErbB2 is a natural signaling component that is required for OPC proliferation, whereas ErbB2 inhibition or genetic knockdown results in OPC differentiation.

Robust hit identification by quality assurance and multivariate data analysis of a high-content, cell-based assay.

Recent technological advances in high-content screening instrumentation have increased its ease of use and throughput, expanding the application of high-content screening to the early stages of drug discovery. However, high-content screens produce complex data sets, presenting a challenge for both extraction and interpretation of meaningful information. This shifts the high-content screening process bottleneck from the experimental to the analytical stage. In this article, the authors discuss different approaches of data analysis, using a phenotypic neurite outgrowth screen as an example. Distance measurements and hierarchical clustering methods lead to a profound understanding of different high-content screening readouts. In addition, the authors introduce a hit selection procedure based on machine learning methods and demonstrate that this method increases the hit verification rate significantly (up to a factor of 5), compared to conventional hit selection based on single readouts only.