Intraoperative Frozen Section of the Prostate Reduces the Risk of Positive Margin Whilst Ensuring Nerve Sparing in Patients with Intermediate and High-Risk Prostate Cancer Undergoing Robotic Radical Prostatectomy: First Reported UK Series

INTRODUCTION

Nerve sparing during robotic radical prostatectomy (RRP) considerably improves post-operative potency and urinary continence as long as it does not compromise oncological outcome. Excision of the neurovascular bundle (NVB) is often performed in patients with intermediate and high risk prostate cancer to reduce the risk of positive surgical margin raising the risk of urinary incontinence and impotence. We present the first UK series outcomes of such patients who underwent an intra-operative frozen section (IOFS) analysis of the prostate during RRP allowing nerve sparing.

PATIENTS AND METHODS

We prospectively analysed the data of 40 patients who underwent an IOFS during RRP at our centre from November 2012 until November 2014. Our IOFS technique involved whole lateral circumferential analysis of the prostate during RRP with the corresponding neurovascular tissue. An intrafascial nerve spare was performed and the specimen was removed intra-operatively via an extension of the 12 mm Autosuture™ camera port without undocking robotic arms. It was then painted by the surgeon and sprayed with "Ink Aid" prior to frozen section analysis. The corresponding NVB was excised if the histopathologist found a positive surgical margin on frozen section.

RESULTS

Median time to extract the specimen, wound closure and re-establishment of pneumoperitoneum increased the operative time by 8 min. Median blood loss for IOFS was 130 ± 97 ml vs. 90 ± 72 ml (p = NS). IOFS was not associated with major complications or with blood transfusion. PSM decreased significantly from non-IOFS RRP series of 28.7 to 7.8% (p < 0.05). Intra-operative PSM on the prostate specimen was seen in 8/40 margin analysis (20%) leading to an excision of the contra-lateral nerve bundle. On analysis of the nerve bundle on a paraffin embedded block, 6 nerve bundle matched tumor on the specimen whereas 2 NVB were retrospectively removed unnecessarily in our series. All 40 patients have undetectable PSA at a mean follow up of 21.2 months (SD 7.79). Functional data at 18 months confirms a reduction in the urinary incontinence from 37% in the IOFS group vs 57% in the non-IOFS group (p = NS). IOFS technique has resulted in a significant increase in intravesical nerve sparing in both T2/T3 patients with intermediate and high risk prostate cancer when appropriately counselled and selected (T2 from 100% in the IOFS group versus 67% and T3 from 100% in the IOFS group to 42%) (p < 0.05).

CONCLUSION

Introduction of the IOFS analysis during intrafascial nerve spare RRP has reduced PSM and the rate of urinary incontinence.

Initial implementation of a Thomson scattering diagnostic for Proto-MPEX

Internal funds have been used at Oak Ridge National Laboratory to enable the initial installation of a laser based, Thomson scattering (TS) diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX). Since the funds are limited in amount and duration, the initial TS system has followed a low cost design and rapid implementation. This paper will discuss the design elements of the initial TS configuration on Proto-MPEX and issues encountered during installation. Avenues of response to system limitations will be discussed, along with considerations for further optimization. The laser system will undergo reconfiguration to enable additional project milestones, e.g., laser induced break-down spectroscopy.

Serum phosphorylated neurofilament-heavy chain levels in multiple sclerosis patients

OBJECTIVES

We evaluated whether the measurement of serum phosphorylated neurofilament heavy chain (pNF-H) titre is likely to be a valid biomarker of axonal injury in multiple sclerosis (MS).

METHODS

Serum pNF-H concentrations were measured by ELISA in cases with relapsing-remitting (RR)-MS (n=81), secondary progressive (SP) MS (n=13) and primary progressive (PP)-MS; n=6) MS; first demyelinating event (FDE; n=82); and unaffected controls (n=135). A subset of MS cases (n=45) were re-sampled on one or multiple occasions. The Multiple Sclerosis Severity Score (MSSS) and MRI measures were used to evaluate associations between serum pNF-H status, disease severity and cerebral lesion load and activity.

RESULTS

We confirmed the presence of pNF-H peptides in serum by ELISA. We showed that a high serum pNF-H titre was detectable in 9% of RR-MS and FDE cases, and 38.5% of SP-MS cases. Patients with a high serum pNF-H titre had higher average MSSS scores and T2 lesion volumes than patients with a low serum pNF-H titre. Repeated sampling of a subset of MS cases showed that pNF-H levels can fluctuate over time, likely reflecting temporal dynamics of axonal injury in MS.

CONCLUSIONS

A subset of FDE/MS cases was found to have a high serum pNF-H titre, and this was associated with changes in clinical outcome measures. We propose that routine measurement of serum pNF-H should be further investigated for monitoring axonal injury in MS.

Preliminary design of laser-induced breakdown spectroscopy for proto-Material Plasma Exposure eXperiment

Laser-induced breakdown spectroscopy (LIBS) is a technique for measuring surface matter composition. LIBS is performed by focusing laser radiation onto a target surface, ablating the surface, forming a plasma, and analyzing the light produced. LIBS surface analysis is a possible diagnostic for characterizing plasma-facing materials in ITER. Oak Ridge National Laboratory has enabled the initial installation of a laser-induced breakdown spectroscopy diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX), which strives to mimic the conditions found at the surface of the ITER divertor. This paper will discuss the LIBS implementation on Proto-MPEX, preliminary design of the fiber optic LIBS collection probe, and the expected results.

Quantifying (12/13)CH(4) migration and fate following sub-surface release to an agricultural soil

Following gas generation in a Geological Disposal Facility (GDF), (14)C-containing gases could migrate through the geosphere, eventually diffusing into soils at the Earth's surface. This paper reports summary results from laboratory and field experiments to obtain information on the probable rates of a) diffusive transport and b) oxidation of (12/13)CH(4) (as a surrogate for (14)CH4) in a typical agricultural soil in the UK. Rates of CH(4) oxidation were generally low in the field and undisturbed soil columns, though a re-packed column of homogenised topsoil oxidised ambient atmospheric CH(4) 20× faster than an undisturbed soil column. In contrast to low observed rates of CH(4) oxidation, the effective diffusion of CH(4) through the soil was rapid. Isotopically labelled CH(4) injected at a depth of 45 cm in the field diffused to the surface and exited the soil over a time period ranging from 8 to 24 h. The rate of CH(4) diffusion through the soil was increased by the presence of ryegrass roots which increased soil porosity and decreased water content. δ(13)C values for laboratory column soils after labelled CH(4) injection experiments showed no sign of residual (13)C, despite the extremely high δ(13)C values of the injected (12/13)CH(4). If laboratory observations are confirmed by measurements in field samples it can be concluded that the majority of (14)CH(4) from a GDF which enters a soil with low methanotrophic activity will be lost to the free atmosphere after diffusing rapidly through the soil column.

Advanced spatio-temporal modelling in long-term radiological assessment models--radionuclides in the soil column

Recent developments in the modelling of key radionuclides in long-timescale assessments of the safety of geological disposal of spent fuel and other radioactive wastes emphasise the influence of the redox conditions of the soil column. Models with higher spatial resolution than typically employed in standard modelling approaches have been shown to capture important features of experimental observations that are not otherwise manifested. Furthermore, models with monthly, rather than annually, averaged parameters and with dynamic transfers between soil and plant have been shown to lead to key differences compared with standard models employing soil-plant concentration ratios. This paper looks at the potential for the inclusion of a higher spatio-temporal resolution in models for long-timescale dose assessments and includes representations of measured plant-root distributions as well as the effects of bioturbation. Focusing here on the distribution and dynamics of radionuclides in the soil column, the effects of different spatial and temporal resolution are compared, together with an investigation of the way in which the hydrology of the soil column is represented. The approach has been successfully incorporated into a practical assessment-level model. Results indicate the potential importance of higher spatio-temporal resolution in modelling soil column dynamics, particularly of weakly sorbing radionuclides in long-timescale assessments featuring sudden transitions between ecosystem types.

A dual role for SHH during phallus development in a marsupial

The mammalian phallus arises from identical primordia in both sexes and is patterned in part by the key morphogen Sonic hedgehog (SHH). We have investigated SHH and other morphogens during phallus development in the tammar wallaby. In this marsupial, testis differentiation and androgen production occurs just after birth, but it takes a further 50-60 days before the phallus becomes sexually dimorphic. One day before birth, SHH was expressed in both sexes in the urethral epithelium. In males, there was a marked upregulation of SHH, GLI2, and AR at day 50 postpartum, a time when testicular androgen production falls. SHH, GLI2, and AR were downregulated in female pouch young treated with androstanediol from days 24-50, but not when treatments were begun at day 29, suggesting an early window of androgen sensitivity. SHH, GLI2, and AR expression in the phallus of males castrated at day 23 did not differ from controls, but there was an increase in SHH and GLI2 and a decrease in FGF8 and BMP4 expression when the animals were castrated at day 29. These results suggest that the early patterning by SHH is androgen-independent followed by an androgen-dependent window of sensitivity and a sharp rise in SHH expression after androgen withdrawal at day 50.

Cross-correlations between three units in cat primary auditory cortex

Here we use a modification of the Joint-Peri-Stimulus-Time histogram (JPSTH) to investigate triple correlations between cat auditory cortex neurons. The modified procedure allowed the decomposition of the xy-pair correlation into a part that is due to the correlation of the x and y units with the trigger unit, and a remaining 'pair correlation'. We analyzed 16 sets of 15-minute duration stationary spontaneous recordings in primary auditory cortex (AI) with between 11 and 14 electrodes from 2 arrays of 8 electrodes each that provided spontaneous firing rates above 0.22 sp/s and for which reliable frequency-tuning curves could be obtained and the characteristic frequency (CF) was estimated. Thus we evaluated 11,282 conditional cross-correlation functions. The predictor for the conditional cross-correlation, calculated on the assumption that the trigger unit had no effect on the xy-pair correlation but using the same fraction of xy spikes, was equal to the conventional pair-wise correlation function between units xy. The conditional correlation of the xy-pair due to correlation of the x and/or y unit with the trigger unit decreased with the geometric mean distance of the xy pair to the trigger unit, but was independent of the pair cross-correlation coefficient. The conditional pair correlation coefficient was estimated at 78% of the measured pair correlation coefficient. Assuming a geometric decreasing effect of activities of units on other electrodes on the conditional correlation, we estimated the potential contribution of a large number of contributing units on the measured pair correlation at 35-50 of that correlation. This suggests that conventionally measured pair correlations in auditory cortex under ketamine anesthesia overestimate the 'true pair correlation', likely resulting from massive common input, by potentially up to a factor 2.

Chlorine disinfection by-products in wastewater effluent: Bioassay-based assessment of toxicological impact

The potential ecological impact of disinfection by-products (DBPs) present in chlorinated wastewater effluents is not well understood. In this study, the chlorinated effluent of traditional wastewater treatment plants (WWTPs) and advanced water reclamation plants (AWRPs) supplying highly-treated recycled water were analyzed for nitrosamines and trihalomethanes (THMs), and a battery of bioassays conducted to assess effluent toxicity. An increase in general toxicity from DBPs was revealed for all wastewaters studied using an in vitro bioluminescence assay. Examples of androgenic activity and estrogenic activity arising from DBPs at specific sampling sites were also observed. The in vivo model (Artemia franciscana) was generally not adversely affected by exposure to DBPs from any of the chlorinated wastewaters studied. The observed toxicity could not be related to the concentrations of THMs and nitrosamines present, indicating that DBPs not monitored in this study were responsible for this. This work highlights the complexity of DBPs mixtures formed in chlorinated wastewaters, illustrating that toxicity of wastewater DBPs cannot be predicted by chemical monitoring of THMs and nitrosamines. The results suggest bioassays may be particularly useful monitoring tools in assessing toxicity arising from DBPs of these complex waters. The research concludes that DBPs formed in the chlorinated wastewaters studied can be toxic and may have a deleterious impact on aquatic organisms that are exposed to them, and therefore, that chlorination or chlorination/dechlorination may not be adequate treatment strategies for the protection of receiving waters. Chlorinated wastewater toxicity (from DBPs) is not well-understood in the Australian context, and this study serves to advise regulators on this issue.

Source apportionment of heavy metals and ionic contaminants in rainwater tanks in a subtropical urban area in Australia

Due to prolonged droughts in recent years, the use of rainwater tanks in urban areas has increased in Australia. In order to apportion sources of contribution to heavy metal and ionic contaminants in rainwater tanks in Brisbane, a subtropical urban area in Australia, monthly tank water samples (24 sites, 31 tanks) and concurrent bulk deposition samples (18 sites) were collected during mainly April 2007-March 2008. The samples were analysed for acid-soluble metals, soluble anions, total inorganic carbon and total organic carbon, and characteristics such as total solid and pH. The Positive Matrix Factorisation model, EPA PMF 3.0, was used to apportion sources of contribution to the contaminants. Four source factors were identified for the bulk deposition samples, including 'crustal matter/sea salt', 'car exhausts/road side dust', 'industrial dust' and 'aged sea salt/secondary aerosols'. For the tank water samples, apart from these atmospheric deposition related factors which contributed in total to 65% of the total contaminant concentration on average, another six rainwater collection system related factors were identified, including 'plumbing', 'building material', 'galvanizing', 'roofing', 'steel' and 'lead flashing/paint' (contributing in total to 35% of the total concentration on average). The Australian Drinking Water Guideline for lead was exceeded in 15% of the tank water samples. The collection system related factors, in particular the 'lead flashing/paint' factor, contributed to 79% of the lead in the tank water samples on average. The concentration of lead in tank water was found to vary with various environmental and collection system factors, in particular the presence of lead flashing on the roof. The results also indicated the important role of sludge dynamics inside the tank on the quality of tank water.

Prostate MRI/ultrasound fusion and biopsy yield

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Background: MRI has been shown useful for identifying targets after negative biopsy. We purport to show the advantage of realtime fusion of MRI data with ultrasound for initial or repeat TRUS biopsy compared with sextant biopsy.

Methods: An IRB-approved prospective study of 57 consecutive men with diffusion weighted imaging and dynamic contrast enhanced (DCE) perfusion in addition to T2-weighted imaging on a Siemens Magnetom 3.0 T Trio using an external phased array coil had targets chosen based on decreased T2 signal with abnormally restricted diffusion or abnormal DCE by a uroradiologist with 6 years experience in prostate imaging, followed by ultrasound-guided biopsies using MR/ultrasound fusion software (Artemis, Eigen) in addition to standard 12-core sextant biopsies.

Results: In 56 patients, 101 suspicious areas were identified by MRI; 28 positive targets were found in 22 men, including 19 Gleason 3+3 (68%), 8 Gleason 3+4 (29%), and one with HGPIN (3%). In 28 patients, neither targets nor systematic cores were positive, and in one patient no targets were identified. Positive cores were found in 12 patients only on targets only including 6 Gleason 3+4. One patient was “upstaged;” the target was Gleason 3+4 whereas the positive systematic cores were Gleason 3+3. In 8 patients the Gleason score of systematic and targeted cores was identical, 2 Gleason 3+4 and 6 Gleason 3+3. In 7 patients systematic cores were Gleason 3+3 with negative targets, all less than 4 mm and less than 25 percent of the core. Fisher exact test showed a trend to significance, p = 0.06 for any cancer identified, and p = 0.03 for Gleason 3+4 disease.

Conclusions: The improved accuracy of MRI-TRUS fusion biopsies may be able to replace systematic biopsies, avoiding the discomfort and risks associated, and improve diagnostic yield, and improve confidence for patients with a small amount of low-grade cancer who opt for active surveillance.

Osteogenic differentiation of mesenchymal stem cells is regulated by osteocyte and osteoblast cells in a simplified bone niche

Mesenchymal stem cells (MSCs) within their native environment of the stem cell niche in bone receive biochemical stimuli from surrounding cells. These stimuli likely influence how MSCs differentiate to become bone precursors. The ability of MSCs to undergo osteogenic differentiation is well established in vitro;however, the role of the natural cues from bone's regulatory cells, osteocytes and osteoblasts in regulating the osteogenic differentiation of MSCs in vivo are unclear. In this study we delineate the role of biochemical signalling from osteocytes and osteoblasts, using conditioned media and co-culture experiments, to understand how they direct osteogenic differentiation of MSCs. Furthermore, the synergistic relationship between osteocytes and osteoblasts is examined by transwell co-culturing of MSCs with both simultaneously. Osteogenic differentiation of MSCs was quantified by monitoring alkaline phosphatase (ALP) activity, calcium deposition and cell number. Intracellular ALP was found to peak earlier and there was greater calcium deposition when MSCs were co-cultured with osteocytes rather than osteoblasts, suggesting that osteocytes are more influential than osteoblasts in stimulating osteogenesis in MSCs. Osteoblasts initially stimulated an increase in the number of MSCs, but ultimately regulated MSC differentiation down the same pathway. Our novel co-culture system confirmed a synergistic relationship between osteocytes and osteoblasts in producing biochemical signals to stimulate the osteogenic differentiation of MSCs. This study provides important insights into the mechanisms at work within the native stem cell niche to stimulate osteogenic differentiation and outlines a possible role for the use of co-culture or conditioned media methodologies for tissue engineering applications.