Ultra-sensitive refractive index sensor using CMOS plasmonic transducers on silicon photonic interferometric platform.

Optical refractive-index sensors exploiting selective co-integration of plasmonics with silicon photonics has emerged as an attractive technology for biosensing applications that can unleash unprecedented performance breakthroughs that reaps the benefits of both technologies. However, towards this direction, a major challenge remains their integration using exclusively CMOS-compatible materials. In this context, herein, we demonstrate, for the first time to our knowledge, a CMOS-compatible plasmo-photonic Mach-Zehnder-interferometer (MZI) based on aluminum and Si3N4 waveguides, exhibiting record-high bulk sensitivity of 4764 nm/RIU with clear potential to scale up the bulk sensitivity values by properly engineering the design parameters of the MZI. The proposed sensor is composed of Si3N4 waveguides butt-coupled with an aluminum stripe in one branch to realize the sensing transducer. The reference arm is built by Si3N4 waveguides, incorporating a thermo-optic phase shifter followed by an MZI-based variable optical attenuation stage to maximize extinction ratio up to 38 dB, hence optimizing the overall sensing performance. The proposed sensor exhibits the highest bulk sensitivity among all plasmo-photonic counterparts, while complying with CMOS manufacturing standards, enabling volume manufacturing.

Contrast-enhanced CT in 100 clear cell renal cell cancers - an analysis of enhancement, tumour size, and survival.

AIM: To investigate the relationship between computed tomography (CT) contrast enhancement of clear cell renal tumours and clinicopathological measures including tumour size, stage, grade, presence of necrosis, and disease-specific survival (DSS). MATERIALS AND METHODS: Patients who had radical nephrectomy for clear cell renal cell carcinoma (RCC) in the period 2004-2007 and who underwent contrast-enhanced (CE)CT at diagnosis were included. Pathological records and radiological imaging were reviewed. Maximum contrast enhancement (MACE) in Hounsfield units (HU) was calculated as the difference between the highest value on pre-contrast and post-contrast imaging in at least three regions of interest within the tumour. MACE was correlated with histopathological measures (size, stage, grade, necrosis) and 5 year DSS. RESULTS: In total, 100 patients with clear cell RCC (median follow-up 40 months) were included with median age of 64 years. MACE values ranged from 21-155 HU with a median of 60.5 HU. There was weak negative correlation between increasing tumour size and MACE (r=-0.2, p=0.045). Patients with necrosis on pathology had lower MACE (71.3 versus 57.5 HU, p=0.03). There was no significant correlation between tumour grade or stage and MACE. Kaplan-Meier plots showed significant survival differences with 5 year DSS for MACE <50 HU 100% versus 5 year DSS for MACE >50 HU 82% (log rank p=0.025). CONCLUSION: MACE decreased with increasing tumour size and was associated with tumour necrosis. MACE >50 HU was associated with a worse 5 year DSS.

Characterisations of human prostate stem cells reveal deficiency in class I UGT enzymes as a novel mechanism for castration-resistant prostate cancer.

BACKGROUND: Evidence increasingly supports that prostate cancer is initiated by the malignant transformation of stem cells (SCs). Furthermore, many SC-signalling pathways are shown to be shared in prostate cancer. Therefore, we planned transcriptome characterisation of adult prostate SCs as a strategy to consider new targets for cancer treatment. METHODS: Intuitive pathway analysis was used for putative target discovery in 12 matched selections of human prostate SCs, transiently amplifying cells and terminally differentiated cells. These were pooled into three groups according to the stage of differentiation for mRNA microarray analysis. Targets identified were validated using uncultured primary tissue (n=12), functional models of prostate cancer and a tissue microarray consisting of benign (n=42) and malignant prostate (n=223). RESULTS: A deficiency in class 1 UDP glucuronosyltransferase (UGT) enzymes (UGT1A) was identified in prostate SCs, which are involved in androgen catabolism. Class 1 UGT enzyme expression was also downregulated in cancer SCs and during progression to metastatic castration-resistant prostate cancer (CRPC). Reduction of UGT1A expression in vitro was seen to improve cell survival and increase androgen receptor (AR) activity, as shown by upregulation of prostate-specific antigen expression. INTERPRETATION: Inactivation of intracellular androgen catabolism represents a novel mechanism to maintain AR activity during CRPC.

Quantified tracking and monitoring of diazepam treated socially housed cynomolgus monkeys.

Quantitative assessment of behavioural patterns is frequently used in rodent toxicity studies, however only limited approaches are available for monkeys. Often qualitative behavioural scoring using functional observation batteries (FOBs) is performed, with difficulties like poor reproducibility or lack of sensitivity. In this study, we investigated whether quantitative behavioural monitoring can be applied to group-housed cynomolgus monkeys. Video-tracking EthoVision® XT system and special analysis software were used to evaluate diazepam (i.v. 1mg/kg) related behavioural changes in group-housed animals. Recordings were made predose and at the anticipated time of maximum drug exposure (T(max)). General parameters such as distance travelled and velocity did not reveal the known sedative effects of diazepam. However, inspection of the automatically generated track images indicated that diazepam-treated animals had more a meandering movement pattern suggesting that diazepam induced a loss of balance which was regained by corrective movements. Therefore, parameters revealing specific aspects of the meandering movement pattern such as velocity profiles and turn angles have been analyzed and revealed an increase in the curvature and in the number of directional changes of the movement path.

Thiothymidine combined with UVA as a potential novel therapy for bladder cancer.

BACKGROUND: Thiothymidine (S(4)TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S(4)TdR and UVA could be an effective treatment for bladder cancer. METHODS: Uptake and incorporation of S(4)TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S(4)TdR and UVA was investigated in an orthotopic model of bladder cancer in rats. RESULTS: Thiothymidine (200 µM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S(4)TdR (10-200 µM) and UVA (1-5 kJ m(-2)) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S(4)TdR into DNA (up to 20-fold at IC(5)) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S(4)TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated. CONCLUSION: These data indicate that the combination of S(4)TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components.

Correction: The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance.

The original version of this article contained an error in Fig. 5a where the colours of the labels representing the Hinge and LBD of the AR were incorrect and did not match the corresponding exons. The corrected version of this Figure now appears in the article. The conclusions of this paper were not affected. The authors apologise for this error and any confusion caused.

The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance.

Stem cell characteristics have been associated with treatment resistance and poor prognosis across many cancer types. The ability to induce and regulate the pathways that sustain these characteristic hallmarks of lethal cancers in a novel in vitro model would greatly enhance our understanding of cancer progression and treatment resistance. In this work, we present such a model, based simply on applying standard pluripotency/embryonic stem cell media alone. Core pluripotency stem cell master regulators (OCT4, SOX2 and NANOG) along with epithelial-mesenchymal transition (EMT) markers (Snail, Slug, vimentin and N-cadherin) were induced in human prostate, breast, lung, bladder, colorectal, and renal cancer cells. RNA sequencing revealed pathways activated by pluripotency inducing culture that were shared across all cancers examined. These pathways highlight a potential core mechanism of treatment resistance. With a focus on prostate cancer, the culture-based induction of core pluripotent stem cell regulators was shown to promote survival in castrate conditions-mimicking first line treatment resistance with hormonal therapies. This acquired phenotype was shown to be mediated through the upregulation of iodothyronine deiodinase DIO2, a critical modulator of the thyroid hormone signalling pathway. Subsequent inhibition of DIO2 was shown to supress expression of prostate specific antigen, the cardinal clinical biomarker of prostate cancer progression and highlighted a novel target for clinical translation in this otherwise fatal disease. This study identifies a new and widely accessible simple preclinical model to recreate and explore underpinning pathways of lethal disease and treatment resistance.

Vascular surgical society of great britain and ireland: prospective randomized double-blind placebo-controlled crossover study to assess the effect of sublingual glyceryl trinitrate in patients with intermittent claudication

BACKGROUND: The effect of sublingual glyceryl trinitrate (GTN) on the claudication distance (CD) and maximum walking distance (MWD) of patients with intermittent claudication was assessed. METHODS: Inclusion criteria were: history of intermittent claudication; resting ankle : brachial pressure index (ABPI) of 1.00 or less; fall in ABPI of more than 0.1 following exercise; and patient not taking nitrates. In the first study 22 patients (median age 69 (range 60-73) years, 16 men, five diabetic, median resting ABPI 0.57 (range 0.1-0.64)) had their CD and MWD measured on a treadmill set at 3.2 km h-1 and 10 per cent gradient. They were then randomized to either GTN or placebo spray, and the distances were remeasured. The crossover portion of the study was then completed. In the second study 28 patients (median age 68 (range 45-84) years, 20 men, six diabetic, median resting ABPI 0.57 (range 0.13-0.98)) were randomized to either GTN or placebo and walked at their own pace along a flat corridor for 15 min. Following a rest of 15 min, the crossover portion of the study was completed. Statistical analysis was by the Wilcoxon matched pairs signed rank test. RESULTS: CONCLUSION: GTN can increase the MWD by 19 per cent when patients with intermittent claudication are walked on a treadmill and by 9 per cent when walking at their own pace on a flat gradient.

The effects of sublingual glyceryl trinitrate on walking distance in patients with intermittent claudication. A randomised, doubled-blind, placebo-controlled, cross-over study.

BACKGROUND: Intermittent claudication (IC) is a common problem in older age. New work shows that the administration of glyceryl trinitrate (GTN) can reduce the fall in ankle brachial pressure index (ABPI) after exercise and can increase maximum walking distance by 19% on treadmill exercise. The aim of this study was to further define the clinical benefits of GTN in patients with PVD. METHODS: The study is of a randomised, double-blind, placebo-controlled cross-over design. We studied 29 patients with intermittent claudication where the median age was 67.5 years (45-84). This included 20 males and nine females, and six of these patients were diabetics. To be selected, the patients had to have a history of IC with a resting ABPI of 1.0 or less, that fell by more than 0.1 on exercise. Patients were walked for 15 min on flat ground following GTN spray or placebo and total distances walked were measured. This was then followed by the crossover component of the trial. RESULTS: Median walking distance with placebo was 825 m (100-1300 m) and with GTN was 900 m (240-1400 m). This is an increase of 9% (p = 0.02, using the Wilcoxon matched pairs signed ranks test). CONCLUSION: This study shows a statistically significant improvement in walking distance with GTN in patients with IC.

Granulomatous mastitis can mimic breast cancer on clinical, radiological or cytological examination: a cautionary tale.

In both women and men, breast lumps are the most common presentation of breast cancer. The following cases illustrate the pathological entity of granulomatous mastitis, which can present simulating breast cancer - including the first description of this condition in a male. These cases demonstrate the difficulty in clinical diagnosis and emphasizes that although there may be clues from the history, clinical awareness that this condition can mimic breast cancer in all aspects of the triple assessment process should arouse suspicion. The importance of histological diagnosis by core or excision biopsy is stressed, as with accurate diagnosis of granulomatous mastitis there is a mandate to avoid unnecessary surgery.

A prospective audit of hypospadias correction in a regional paediatric surgery centre.

AIM: To prospectively review the management and treatment of hypospadias in a single regional centre, and in particular, to assess the spectrum of cases treated, techniques used and to determine the nature of the complications. METHODS: One hundred and fifty-three consecutive boys undergoing hypospadias repair during a 36-month period were included in the study. Information was collected prospectively and included the site of the urethral meatus, presence of chordee, surgical technique employed, use of urinary diversion, and the prescription of postoperative antibiotics and analgesics. Patients were assessed in the clinic following surgery at which time information on outcome and complications was obtained. RESULTS: One hundred and fifty-seven procedures for hypospadias were performed. Single-stage reconstruction was performed in 145 boys. GRAP (glanular reconstruction and preputioplasty) repair was the most common operation employed (n=112). The overall fistula rate was 11.7 % with the majority of patients having a satisfactory functional and cosmetic outcome following surgery. CONCLUSION: A variety of techniques can be employed to provide satisfactory correction of hypospadias with an increasing emphasis on single-stage day case procedures. GRAP repair is the favoured option for distal hypospadias and incorporates preservation of the prepuce.

Contemporaneous cell spreading and phagocytosis: magneto-resistive real-time monitoring of membrane competing processes.

Adhesion and spreading of cells strongly depend on the properties of the underlying surface, which has significant consequences in long-term cell behavior adaption. This relationship is important for the understanding of both biological functions and their bioactivity in disease-related applications. Employing our magnetic lab-on-a-chip system, we present magnetoresistive-based real-time and label-free detection of cellular phagocytosis behavior during their spreading process on particle-immobilized sensor surfaces. Cell spreading experiments carried out on particle-free and particle-modified surfaces reveal a delay in spreading rate after an elapsed time of about 2.2h for particle-modified surfaces due to contemporaneous cell membrane loss by particle phagocytosis. Our associated magnetoresistive measurements show a high uptake rate at early stages of cell spreading, which decreases steadily until it reaches saturation after an average elapsed time of about 100 min. The corresponding cellular average uptake rate during the entire cell spreading process accounts for three particles per minute. This result represents a four times higher phagocytosis efficiency compared to uptake experiments carried out for confluently grown cells, in which case cell spreading is already finished and, thus, excluded. Furthermore, other dynamic cell-surface interactions at nano-scale level such as cell migration or the dynamics of cell attachment and detachment are also addressable by our magnetic lab-on-a-chip approach.

Accuracy of the revised 2010 TNM classification in predicting the prognosis of patients treated for renal cell cancer in the north east of England.

BACKGROUND: The TNM classification for renal cell cancer (RCC) should accurately predict and assign prognostic information for patients. In this study the recent 2010 revision to the TNM classification was compared with the previous 2002 classification with regard to survival outcomes. METHODS: All patients having radical nephrectomy for RCC in the 5-year period 2004-8 at a tertiary referral centre were included. Pathological and radiological records were reviewed to identify TNM stage (2002 and 2010 classification) and survival data were captured. RESULTS: 345 patients with RCC were identified. Based on the 2002 TNM staging system and using outcomes in T1 staged tumours as a baseline, statistically significant differences in disease-specific survival were noted between patients with T1 and T3b tumours (log rank p<0.001) but not between those with T1 and T3a tumours (p=0.33). However, when tumour stage was reassigned according to the 2010 classification, patients with T3a tumours were also found to do statistically worse than T1 staged disease (p<0.001). CONCLUSION: In our cohort, the new 2010 TNM reclassification of T3 tumours showed better correlation with predicting worsening outcomes compared with localised disease.

Magnetoresistive-based real-time cell phagocytosis monitoring.

The uptake of large particles by cells (phagocytosis) is an important factor in cell biology and also plays a major role in biomedical applications. So far, most methods for determining the phagocytic properties rely on cell-culture incubation and end-point detection schemes. Here, we present a lab-on-a-chip system for real-time monitoring of magnetic particle uptake by human fibroblast (NHDF) cells. It is based on recording the time evolution of the average position and distribution of magnetic particles during phagocytosis by giant-magnetoresistive (GMR) type sensors. We employ particles with a mean diameter of 1.2 µm and characterize their phagocytosis-relevant properties. Our experiments at physiological conditions reveal a cellular uptake rate of 45 particles per hour and show that phagocytosis reaches saturation after an average uptake time of 27.7h. Moreover, reference phagocytosis experiments at 4°C are carried out to mimic environmental or disease related inhibition of the phagocytic behavior, and our measurements clearly show that we are able to distinguish between cell-membrane adherent and phagocytosed magnetic particles. Besides the demonstrated real-time monitoring of phagocytosis mechanisms, additional nano-biointerface studies can be realized, including on-chip cell adhesion/spreading as well as cell migration, attachment and detachment dynamics. This versatility shows the potential of our approach for providing a multifunctional platform for on-chip cell analysis.

Hunterian Lecture. Characterisation of human prostate epithelial progenitor differentiation in response to androgens.

INTRODUCTION: A stem cell model of prostate cancer tumourigenesis explains progression to castration resistant prostate cancer (CRPC) and offers novel perspectives in targeting this cancer in its more advanced forms. Androgen receptor (AR) regulated pathways are central mechanisms in progression to CRPC. However, AR was thought to be lacking in prostate stem cell enriched fractions. Potential low levels of AR expression in stem cell enriched cells were investigated and potential direct effects of androgen were examined. METHODS: Human prostate stem cell enriched populations, based on high α(2)ß(1) integrin expression (α(2)ß(1)(hi)), were selected from primary human prostate tissue in men undergoing transurethral prostatectomy or cystoprostatectomy. Effects on differentiation were assayed with flow cytometry using differentiation-specific markers. RESULTS: Low levels of AR were demonstrable in α(2)ß(1)(hi) cells following inhibition of the proteasome using MG132. Furthermore, a direct effect of androgen was shown in stabilising/inducing AR expression. Androgen treatment of α(2)ß(1)(hi) cells was associated with the induction of differentiation using a number of differentiation-specific markers (prostatic acid phosphatase, cytokeratin 18 and AR) with increases ranging from 49% to 67% (p<0.05). These effects were blocked with the AR-specific inhibitor bicalutamide (p<0.05). These data support a role of direct androgen activity on stem cell enriched cells in the prostate and the implications of these findings are discussed.

A critical systematic review of recent clinical trials comparing open retropubic, laparoscopic and robot-assisted laparoscopic radical prostatectomy.

The surgical treatment of prostate cancer has evolved rapidly, driven by technological advances that have made minimally-invasive prostatectomy feasible. The contemporary surgical approaches are laparoscopic radical prostatectomy (LRP) and robot-assisted laparoscopic radical prostatectomy (RALP). These are now considered standard modalities of treatment in urology departments across North America, Europe and centres of excellence world-wide. However, despite the widespread adoption of minimally-invasive approaches there are only a handful of robust studies directly comparing the results of these techniques with the gold standard approach of open radical prostatectomy (ORP). Of note, uncertainty remains over exactly which men with localised prostate cancer will benefit from radical treatment and the reduction of surgical side-effects is paramount in optimising outcomes. This systematic review examines the current status of minimally- invasive prostatectomy focussing on peri-operative, oncological and urogenital functional outcomes.

Multifrequency impedance measurement technique for wireless characterization of microbiological cell cultures.

An impedance measurement system with probe signal frequencies up to 50 kHz with AC-probe voltages below 30 mV rms was integrated for wireless and battery-free monitoring of microbiological cell cultures. The here presented modular design and the use of state-of-the-art components greatly eases adoptions to a wide range of biotechnological applications without the need of bulky LCR-meters or potentiostats. The device had a power consumption of less than 2.5 mA at a 3.3 V single power supply and worked trouble-free within the humid environment of a cell culture incubator. Measurements on lumped RC-elements showed an error of less than 1% for absolute values and less than 1° regarding the phase of the complex impedance. The performance of sensor devices with interdigitated electrode structures for the measurement of adherent cell cultures was tested in the presence of phosphate-buffered saline solution in the humid atmosphere of an incubator for biological cell cultures.

Highly sensitive passive radio frequency identification based sensor systems.

A novel platform for sensor applications based on radio frequency (rf) identification technology, where passive tags are powered by the rf-field of a reader, is presented. The sophisticated energy harvesting system of the tag enables a blanking of the rf-field for a defined period, while supplying the tag electronics with a highly stable voltage and a power of 25 mW for 100 ms. During this time, span measurements can be performed without interferences of the rf-field. The presented tags work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions as well as in harsh environments.

Wireless powered electronic sensors for biological applications.

Radio frequency identification technology is used to power a novel platform of sensor devices. The employed energy harvesting system of the individual sensors enables a blanking of the radio frequency field for a defined period, while supplying the sensor electronics with a highly stable voltage. This guarantees interference free operation of the electronic circuitry during measurements. The implementation of this principle is demonstrated for a sensor system which is based on insets for state-of-the-art micro-titer-plates. Each inset is carrying electronic circuitry and an interdigitated electrode system which is acting as sensor for recording alterations of the cell metabolism. The presented sensor devices work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions.

Aberrant expression of extracellular signal-regulated kinase 5 in human prostate cancer.

Abnormal intracellular signaling contributes to carcinogenesis and may represent novel therapeutic targets. mitogen/extracellular signal-regulated kinase kinase-5 (MEK5) overexpression is associated with aggressive prostate cancer. In this study, we examined the role of extracellular signal-regulated kinase (ERK5, an MAPK and specific substrate for MEK5) in prostate cancer. ERK5 immunoreactivity was significantly upregulated in high-grade prostate cancer when compared to benign prostatic hyperplasia (P<0.0001). Increased ERK5 cytoplasmic signals correlated closely with Gleason sum score (P<0.0001), bony metastases (P=0.0044) and locally advanced disease at diagnosis (P=0.0023), with a weak association with shorter disease-specific survival (P=0.036). A subgroup of patients showed strong nuclear ERK5 localization, which correlated with poor disease-specific survival and, on multivariant analysis, was an independent prognostic factor (P<0.0001). Analysis of ERK5 expression in matched tumor pairs (before and after hormone relapse, n=26) revealed ERK5 nuclear expression was significantly associated with hormone-insensitive disease (P=0.0078). Similarly, ERK5 protein expression was increased in an androgen-independent LNCaP subline. We obtained the following in vitro and in vivo evidence to support the above expression data: (1) cotransfection of ERK5wt and MEK5D constructs in PC3 cells results in predominant ERK5 nuclear localization, similar to that observed in aggressive clinical disease; (2) ERK5-overexpressing PC3 cells have enhanced proliferative, migrative and invasive capabilities in vitro (P<0.0001), and were dramatically more efficient in forming tumors, with a shorter mean time for tumors to reach a critical volume of 1000 mm(3), in vivo (P<0.0001); (3) the MEK1 inhibitor, PD184352, blocking ERK1/2 activation at low dose, did not suppress proliferation but did significantly decrease proliferation at a higher dose required to inhibit ERK5 activation. Taken together, our results establish the potential importance of ERK5 in aggressive prostate cancer.