Synergy Assessment of Four Antimicrobial Bioactive Compounds for the Combinational Treatment of Bacterial Pathogens.

Antimicrobial resistance (AMR) has become a topic of great concern in recent years, with much effort being committed to developing alternative treatments for resistant bacterial pathogens. Drug combinational therapies have been a major area of research for several years, with modern iterations using combining well-established antibiotics and other antimicrobials with the aim of discovering complementary mechanisms. Previously, we characterised four GRAS antimicrobials that can withstand thermal polymer extrusion processes for novel medical device-based and therapeutic applications. In the present study, four antimicrobial bioactive-silver nitrate, nisin, chitosan and zinc oxide-were assessed for their potential combined use as an alternative synergistic treatment for AMR bacteria via a broth microdilution assay based on a checkerboard format. The bioactives were tested in arrangements of two-, three- and four-drug combinations, and their interactions were determined and expressed in terms of a synergy score. Results have revealed interesting interactions based on treatments against recognised test bacterial strains that cause human and animal infections, namely E. coli, S. aureus and S. epidermidis. Silver nitrate was seen to greatly enhance the efficacy of its paired treatment. Combinations with nisin, which is a lantibiotic, exhibited the most interesting results, as nisin has no effect against Gram-negative bacteria when used alone; however, it demonstrated antimicrobial effects when combined with silver nitrate or chitosan. This study constitutes the first study to both report on practical three- and four-drug combinational assays and utilise these methods for the assessment of established and emerging antimicrobials. The novel methods and results presented in this study show the potential to explore previously unknown drug combination compatibility measures in an ease-of-use- and high-throughput-based format, which can greatly help future research that aims to identify appropriate alternative treatments for AMR, including the screening of potential new bioactives biorefined from various sources.

Modified transurethral resection of the prostate (TURP) for men with moderate lower urinary tract symptoms (LUTS) before brachytherapy is safe and feasible.

OBJECTIVE: To report the urinary toxicity outcomes for patients at greater risk of voiding symptoms and retention who received a modified limited transurethral resection of the prostate (TURP) before low-dose rate (LDR) brachytherapy. PATIENTS AND METHOD: Data were analysed from patients receiving the above procedures between 2006 to present, taken from the prospective brachytherapy database of 2000 patients at the St. Luke's Cancer Centre. The limited TURP (TURP(BXT) ) was performed at a median (range) of 64 (25-205) days before seed implantation with a median resection weight of 1.15 g. Selection criteria were based on patients with moderate lower urinary tract symptoms, poor flow or post-void residual urine volume (PVR), or a prominent middle lobe or high bladder neck on transrectal ultrasonography. Baseline prostate cancer characteristics, uroflowmetry, International Prostate Symptom Score (IPSS) and quality-of-life QoL scores were collected and compared with follow-up IPSS and QoL scores. RESULTS: Data for 112 patients was gathered from the database. The TURP(BXT) resulted in statistically significant improvements before LDR brachytherapy in maximum urinary flow rate (Qmax ) and PVR, IPSS and QoL scores (the mean Qmax before vs after the TURP(BXT) was 11.3 vs 16.7 mL/s). The IPSS and QoL scores at 6 months after seed implantation were increased compared with baseline values before the TURP(BXT) (mean IPSS at 6 months 11.7 vs 9.2 before TURP(BXT) ), but no difference at 1 year (mean IPSS 9), and improved scores at 2, 3, 4 and 5 years follow-up (mean IPSS of 7.9, 5.6, 5.3 and 7.4, respectively). CONCLUSION: The present study suggests patients at increased risk of deteriorating voiding symptoms, including urinary retention, are no longer contraindicated against LDR brachytherapy if they receive a modified TURP before seed implantation. This procedure does not appear to carry the risk of urinary incontinence thought to be associated with a conventional TURP before LDR brachytherapy.

Postoperative haemorrhage following transurethral resection of the prostate (TURP) and photoselective vaporisation of the prostate (PVP).

INTRODUCTION: Intractable haemorrhage after endoscopic surgery, including transurethral resection of the prostate (TURP) and photoselective vaporisation of the prostate (PVP), is uncommon but a significant and life-threatening problem. The knowledge and technical experience to deal with this complication may not be wide-spread among urologists and trainees. We describe our series of TURPs and PVPs and the incidence of postoperative bleeding requiring intervention. PATIENTS AND METHODS: We retrospectively reviewed 437 TURPs and 590 PVPs over 3 years in our institution. We describe the conservative, endoscopic and open prostatic packing techniques used for patients who experienced postoperative bleeding. RESULTS: Of 437 TURPs, 19 required endoscopic intervention for postoperative bleeding. Of 590 PVPs, two patients were successfully managed endoscopically for delayed haemorrhage at 7 and 13 days post-surgery, respectively. In one TURP and one PVP patient, endoscopic management was insufficient to control postoperative haemorrhage and open exploration and packing of the prostatic cavity was performed. CONCLUSIONS: Significant bleeding after endoscopic prostatic surgery is still a potentially life-threatening complication. Prophylactic measures have been employed to reduce peri-operative bleeding but persistent bleeding post-endoscopic prostatic surgery should be treated promptly to prevent the risk of rapid deterioration. We demonstrated that the technique of open prostate packing may be life-saving.

Sorafenib (BAY 43-9006) inhibits tumor growth and vascularization and induces tumor apoptosis and hypoxia in RCC xenograft models.

PURPOSE: New research findings have revealed a key role for vascular endothelial growth factor (VEGF) in the stimulation of angiogenesis in clear cell renal carcinoma (RCC) which is a highly vascularized and treatment-resistant tumor. Sorafenib (BAY 43-9006, Nexavar) is a multi-kinase inhibitor which targets receptor tyrosine and serine/threonine kinases involved in tumor progression and tumor angiogenesis. The effect of sorafenib on tumor growth and tumor histology was assessed in both ectopic and orthotopic mouse models of RCC. METHODS: Sorafenib was administered orally to mice bearing subcutaneous (SC, ectopic) or sub-renal capsule (SRC, orthotopic) tumors of murine (Renca) or human (786-O) RCC. Treatment efficacy was determined by measurements of tumor volume and tumor growth delay. In mechanism of action studies, using the 786-O and Renca RCC tumor models, the effect of sorafenib was assessed after dosing for 3 or 5 days in the SC models and 21 days in the SRC models. Inhibition of tumor angiogenesis was assessed by measuring level of CD31 and alpha-smooth muscle actin (alphaSMA) staining by immunohistochemistry (IHC). The effect of sorafenib on MAPK signaling, cell cycle progression and cell proliferation was also assessed by IHC by measuring levels of phospho-ERK, phospho-histone H3 and Ki-67 staining, respectively. The extent of tumor apoptosis was measured by terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. Finally, the effects of sorafenib on tumor hypoxia was assessed in 786-O SC model by injecting mice intravenously with pimonidazole hydrochloride 1 h before tumor collection and tumor sections were stained with a FITC-conjugated Hypoxyprobe antibody. RESULTS: Sorafenib produced significant tumor growth inhibition (TGI) and a reduction in tumor vasculature of both ectopic and orthotopic Renca and 786-O tumors, at a dose as low as 15 mg/kg when administered daily. Inhibition of tumor vasculature was observed as early as 3 days post-treatment, and this inhibition of angiogenesis correlated with increased level of tumor apoptosis (TUNEL-positive) and central necrosis. Consistent with these results, a significant increase in tumor hypoxia was also observed 3 days post-treatment in 786-O SC model. However, no significant effect of sorafenib on phospho-ERK, phospho-histone H3 or Ki-67 levels in either RCC tumor model was observed. CONCLUSION: Our results show the ability of sorafenib to potently inhibit the growth of both ectopically- and orthotopically-implanted Renca and 786-O tumors. The observed tumor growth inhibition and tumor stasis or stabilization correlated strongly with decreased tumor angiogenesis, which was due, at least in part, to inhibition of VEGF and PDGF-mediated endothelial cell and pericyte survival. Finally, sorafenib-mediated inhibition of tumor growth and angiogenesis occurred at concentrations equivalent to those achieved in patients in the clinic.

Discovery and development of sorafenib: a multikinase inhibitor for treating cancer.

Since the molecular revolution of the 1980s, knowledge of the aetiology of cancer has increased considerably, which has led to the discovery and development of targeted therapies tailored to inhibit cancer-specific pathways. The introduction and refinement of rapid, high-throughput screening technologies over the past decade has greatly facilitated this targeted discovery and development process. Here, we describe the discovery and continuing development of sorafenib (previously known as BAY 43-9006), the first oral multikinase inhibitor that targets Raf and affects tumour signalling and the tumour vasculature. The discovery cycle of sorafenib (Nexavar; Bayer Pharmaceuticals) - from initial screening for a lead compound to FDA approval for the treatment of advanced renal cell carcinoma in December 2005 - was completed in just 11 years, with approval being received approximately 5 years after the initiation of the first Phase I trial.

Time to rebrand transurethral resection of the prostate?

PURPOSE OF REVIEW: Transurethral resection of the prostate remains the gold standard treatment for benign prostatic obstruction. Owing to the significant morbidity traditionally associated with the procedure, a large number of expensive, high-energy alternative treatments have been developed, which have enjoyed varying degrees of success. At the same time, transurethral resection of the prostate has evolved into a safer operation whilst maintaining its excellent efficacy. This review aims to outline the major advances that have occurred recently in transurethral resection of the prostate. RECENT FINDINGS: Optimizing each stage of transurethral resection of the prostate can result in reduced morbidity. Preoperative treatment with oral antiandrogens and 5-reductase inhibitors appears to reduce intraoperative bleeding, appropriate prophylactic antibiotic regimens reduce postoperative infection rates, improved instrumentation and diathermy delivery can reduce intraoperative bleeding and hence reduce postoperative irrigation requirements, and alcohol monitoring of irrigant absorption can eliminate transurethral resection syndrome. Careful patient selection, meticulous surgical technique combined with an aggressive postoperative irrigation and catheter removal policy can result in transurethral resection of the prostate being performed safely on a day-case basis. SUMMARY: Whilst our attention has been distracted by the many alternative treatments brought to the market over the past decade or so, transurethral resection of the prostate has been undergoing a quiet evolution. With fine tuning of all aspects of the patient journey we can now offer a procedure with excellent long-term efficacy combined with reduced morbidity and inpatient stay.