Digital differential confocal microscopy based on spatial shift transformation

Differential confocal microscopy is a particularly powerful surface profilometry technique in industrial metrology due to its high axial sensitivity and insensitivity to noise. However, the practical implementation of the technique requires the accurate positioning of point detectors in three-dimensions. We describe a simple alternative based on spatial transformation of a through-focus series of images obtained from a homemade beam scanning confocal microscope. This digital differential confocal microscopy approach is described and compared with the traditional Differential confocal microscopy approach. The ease of use of the digital differential confocal microscopy system is illustrated by performing measurements on a 3D standard specimen.

Abstract P6-09-01: Central Ki67 analysis as a predictor for adjuvant capecitabine efficacy in early breast cancer (EBC) subtypes in US oncology trial 01062

Background: USON 01062 (O’Shaughnessy J, et al. Proc SABCS, 2010, abst S4-2) showed no improvement in the primary endpoint of disease-free survival (DFS) (median FU 5 yrs: HR 0.84, 95% CI: 0.67-1.05; p = 0.125) with the addition of capecitabine (X) to standard adjuvant chemotherapy, but showed improvement in OS (HR 0.68, 95% CI: 0.51-0.92; p = 0.011). Exploratory analysis of local pathology-assessed Ki67 suggested benefit from adjuvant X in pts with more highly proliferative cancers with Ki67 ≥ 10% (Pippen J et al. Proc ASCO, 2011, abst 500). The objective of this study is to determine whether centrally-performed Ki67 IHC results corroborate or refute this finding.

Methods: 2610 pts with resected high risk EBC were randomized to receive 4 cycles of AC (doxorubicin 60mg/m2 and cyclophosphamide 600mg/m2) IV every 3 wks for 4 cycles followed by either docetaxel 100mg/m2 IV or docetaxel 75mg/m2 IV plus X 825mg/m2 PO bid for 14 days every 3 wks for 4 cycles. Archival primary breast cancer tissue was collected on 2000 pts for predictive biomarker analyses. Central Ki67 IHC was performed using the anti-Ki67 monoclonal antibody SP6 and was read by one pathologist (HK) according to published recommendations (Dowsett M, et al. JNCI 103:1-9, 2011).

Results: Central Ki67 IHC has been performed on 1440 pts who had centrally-validated informed consents. The distribution of% Ki67-positive cells by locally-assessed ER/HER2 subtype is shown below. 45% of HR+ HER2- BCs had a Ki67 ≤ 10%, while 24% had a Ki67 11% to 20%, and 31% had a Ki67 > 20%. The concordance between the local vs central Ki67 results was low at 46% for Ki67 <10%, 49% for Ki67 10%-20%, and 76% for Ki67 > 20%. The central Ki67 results tended to be higher than the local testing results. Central mRNA classifiers were developed for ER, PR, HER2 and Ki67 using Fluidigm Microfluidics Dynamic Arrays and correlate highly with central IHC assessment of these markers.

Conclusions: HR+ HER2- EBC is enriched for cancers with a low proliferative rate, a group of pts unlikely to benefit from the cell cycle-specific cytotoxic agent, capecitabine. Analyses of the impact of adjuvant X added to AC/T in EBC pts according to ER status, and according to Ki67 (analyzed as a binary and continuous variable) will be performed prior to SABCS, 2013.

Number of Patients% Ki67 Pos CellsTotal *HR+TNHER2+/HR+HER2+/ HR-0-104163622222711-151391066151016-20126871615821-3018411539201031-1005751403423555Total144081042510790*Totals do not equal sum of subtype categories due to missing HER2 information

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-09-01.

Effect of phage and host concentration on the inactivation of Escherichia coli O157:H7 on cooked and raw beef

A previously described phage infecting Escherichia coli O157:H7 was added to raw and cooked beef pieces at concentrations ranging from 10(1)-10(8) plaque forming units/cm(2) to either low (<100 CFU/cm(2)) or high (10(4) CFU/cm(2)) concentrations of host bacterial cells. Incubation for up to 24 h was performed at 5 ℃ and 24 ℃ to simulate refrigerated and room temperature storage/temperature abuse. Surviving bacteria were enumerated during the incubation period, with phages being counted at the first and last sampling times. Significant reductions of E. coli O157:H7 of the order of >4 log10 CFU/cm(2) at both temperatures could be achieved compared to phage-free controls. There was a trend for greater inactivation to occur with increasing phage concentration. While re-growth of surviving cells occurred in nearly all samples incubated for 24 h at 24 ℃, these conditions are not typical of those experienced by perishable foods. It was concluded that phages can be used to reduce the concentration of a bacterial pathogen on meat, but the concentration of phages needs to be high (>4-5 log10 plaque forming units/cm(2)) for reductions to occur. A concentration of the order 8 log10 plaque forming units/cm(2) was needed to achieve a 4 log10 CFU/cm(2) reduction.

Managing type 1 diabetes ‑ a journey from starvation to insulin pump

With the discovery of insulin in 1921, hopes were high that type 1 diabetes mellitus would soon be cured. However, this goal has remained elusive. Nevertheless, technological advances have improved the management of diabetes and the quality of life of patients with diabetes. One of these advances has been the development of the insulin pump. This article reviews the development of insulin pumps and outlines the advantages and disadvantages of insulin pumps currently available.

Use of a bacteriophage to inactivate Escherichia coli O157:H7 on beef

A number of outbreaks of Escherichia coli O157:H7 infections involving beef have been reported. Options for controlling bacterial pathogens in raw foods are limited, but one is to use bacteriophages (phages). We describe the isolation and characterisation of phage FAHEc1, which infects E. coli O157, and its ability to kill its host in vitro and on beef. The phage belonged to the family Myoviridae and lysed 28 of 30 E. coli O157 (:H7, :HNM and :H not specified) isolates, only one other non-O157 E. coli serotype (O162:H7), and none of the other 13 bacterial species tested. The phage did not contain stx1, stx2, eae or ehxA virulence genes as assessed by PCR. An approximate 4 log₁₀ inactivation of E. coli O157:H7 occurred at 5 °C in the presence of phage FAHEc1 at >10⁷ PFU/ml in broth in vitro. On thinly sliced beef pieces incubated at 37 °C, a > 2.7 log₁₀ reduction occurred with 3.2 × 10⁷ PFU/4 cm² meat piece. At lower phage concentrations (10³-10⁴ PFU/4 cm² piece) phage replication occurred on beef at 37 °C. When the phage was applied to beef pieces under conditions simulating hot boning and conventional carcass cooling, inactivation of E. coli O157:H7 of approximately 2 log₁₀ was measured under optimal conditions with phages applied at 3.2 × 10⁷ PFU/4 cm² meat piece.

Cranberry juice induces nitric oxide-dependent vasodilation in vitro and its infusion transiently reduces blood pressure in anesthetized rats

ABSTRACT Red wine vasodilates rat aortae, an effect attributed to polyphenolic compounds. Cranberry juice (CBJ) is also rich in polyphenols. We determined that CBJ has vasorelaxing properties similar to those of red wine. Rat aortic rings cleaned in Krebs buffer, pH 7.4, bubbled with 95% O(2) and 5% CO(2) were recovered for 30 minutes at 37 degrees C under 2.0 g tension. After phenylephrine (PE, 100 mumol/L) contraction, acetylcholine (3 mumol/L)-induced relaxation of intact vessel was significantly higher than in denuded vessels (59.1 +/- 0.27% versus 10.1 +/- 0.09% of the maximal PE contraction; P <.003). After a second PE contraction, a 1:100 dilution of CBJ was added. Intact rings were vasodilated by CBJ with 56.7 +/- 0.26% relaxation, compared to denuded rings with 8.9 +/- 0.06% relaxation (P <.002). Addition of L-NAME reversed CBJ-induced vasorelaxation in intact vessels with 0.54 +/- 0.34 g compared to 0.04 +/- 0.04 g in denuded vessels (P <.007). Subsequent addition of L-arginine resulted in a return of vasodilation in intact vessels. Additionally, CBJ infusion at a 1:100 dilution of estimated blood volume resulted in a 16% reduction of mean arterial blood pressure in anesthetized rats. This study suggests that, like red wine, CBJ has the capacity to exert in vitro and in vivo vasodilatory effects.

Control of Listeria monocytogenes growth in a ready-to-eat poultry product using a bacteriophage

A bacteriophage (phage) that infected strains of the species Listeria monocytogenes as well as Listeria ivanovii and Listeria welshimeri, but not Listeria grayi or Listeria innocua, was isolated from sheep faeces. The phage had a contractile tail and an icosohedral head indicating that it was a myovirus, and was morphologically similar to phage A511. At 30 °C, phages added at 5.2 × 10⁷ PFU ml⁻¹ prevented the growth in broth of L. monocytogenes present at approximately twice this concentration for 7 h, but re-growth occurred such that the concentration after 24 h incubation was similar in both control and phage-treated cultures. At the same temperature, but on the surface of vacuum-packed ready-to-eat chicken breast roll, there was an immediate 2.5 log₁₀ CFU cm⁻² reduction in pathogen concentration following addition of phages and then re-growth. However, at a temperature reflecting that at which a chilled food might be held (5 °C), this re-growth was prevented over 21 days incubation. The data suggest a dose-dependent rapid reduction in pathogen concentration followed by no continued phage-mediated effect. These results, alongside other published data, indicate that a high concentration of phages per unit area is required to ensure significant inactivation of target pathogens on food surfaces.

An in-vacuum diffractometer for resonant elastic soft x-ray scattering

We describe the design, construction, and performance of a 4-circle in-vacuum diffractometer for resonant elastic soft x-ray scattering. The diffractometer, installed on the resonant elastic and inelastic x-ray scattering beamline at the Canadian Light Source, includes 9 in-vacuum motions driven by in-vacuum stepper motors and operates in ultra-high vacuum at base pressure of 2 × 10(-10) Torr. Cooling to a base temperature of 18 K is provided with a closed-cycle cryostat. The diffractometer includes a choice of 3 photon detectors: a photodiode, a channeltron, and a 2D sensitive channelplate detector. Along with variable slit and filter options, these detectors are suitable for studying a wide range of phenomena having both weak and strong diffraction signals. Example measurements of diffraction and reflectivity in Nd-doped (La,Sr)(2)CuO(4) and thin film (Ga,Mn)As are shown.

Controlled manipulation of elastomers with radiation: Insights from multiquantum nuclear-magnetic-resonance data and mechanical measurements

Filled and cross-linked elastomeric rubbers are versatile network materials with a multitude of applications ranging from artificial organs and biomedical devices to cushions, coatings, adhesives, interconnects, and seismic-isolation, thermal, and electrical barriers. External factors such as mechanical stress, temperature fluctuations, or radiation are known to create chemical changes in such materials that can directly affect the molecular weight distribution (MWD) of the polymer between cross-links and alter the structural and mechanical properties. From a materials science point of view it is highly desirable to understand, affect, and manipulate such property changes in a controlled manner. Unfortunately, that has not yet been possible due to the lack of experimental characterization of such networks under controlled environments. In this work we expose a known rubber material to controlled dosages of γ radiation and utilize a newly developed multiquantum nuclear-magnetic-resonance technique to characterize the MWD as a function of radiation. We show that such data along with mechanical stress-strain measurements are amenable to accurate analysis by simple network models and yield important insights into radiation-induced molecular-level processes.

Resolution of oblique-plane images in sectioning microscopy

Live biological specimens exhibit time-varying behavior on the microscale in all three dimensions. Although scanning confocal and two-photon microscopes are able to record three-dimensional image stacks through these specimens, they do so at relatively low speeds which limits the time resolution of the biological processes that can be observed. One way to improve the data acquisition rate is to image only the regions of a specimen that are of interest and so researchers have recently begun to acquire two-dimensional images of inclined planes or surfaces extending significantly into the z-direction. As the resolution is not uniform in x, y and z, the images possess non-isotropic resolution. We explore this theoretically and show that images of an oblique plane may contain spectral content that could not have been generated by specimen features lying wholly within the plane but must instead arise from a spatial variation in another direction. In some cases we find that the image contains frequencies three times higher than the resolution limit for in-plane features. We confirm this finding through numerical simulations and experiments on a novel, oblique-plane imaging system and suggest that care be taken in the interpretation of such images.

Quality of life and patient satisfaction with enhanced recovery protocols

AIM

 The aim of this study was to systematically review the literature on the influence of enhanced recovery after surgery (ERAS) protocols and health related quality of life (HQoL) and patient satisfaction.

METHOD

A systematic review of the literature from January 1990 to February 2009 was undertaken. Studies were included if they compared HQoL and/or patient satisfaction after ERAS and conventional surgery (CS). Jadad score was used to evaluate the studies. Results were divided into immediate (first week), early (second to third week) and late (more than 30 days after surgery) post-operative phases. A meta-analysis was not possible due to the heterogeneity of the studies.

RESULTS

Ten publications were included in the final analysis. In the first week after surgery, two non-randomised trials found reduced fatigue and another 2 non-randomised studies found reduced pain with ERAS. One randomised study found increased emotional distress on SF36 in ERAS patients. At two to three weeks after surgery, none of the multidimensional HQoL measures showed any differences. Increased fatigue was reported with CS in 2 studies. Limitations in activities of daily living were more marked after CS in one study. Beyond 30 days after surgery, none of the HQoL measures showed any differences. Only one non-randomised study compared patient satisfaction after ERAS and CS and no difference was found.

CONCLUSION

There is no evidence that ERAS adversely affect HQoL or patient satisfaction. Certain aspects of HQoL such as pain and fatigue may improve with ERAS. Further research is required, especially in the early post-operative period.

Optical sectioning in fluorescence microscopy

We review the origins of optical sectioning in fluorescence microscopy in terms of the structure of the illumination used to generate the fluorescence within the specimen. We note that the conventional microscope using essentially uniform illumination does not exhibit optical sectioning whereas the confocal microscope using point (many spatial frequencies) illumination does. We show that the optical sectioning strength of a confocal microscope is not optimal and discuss the advantages of using a single spatial frequency for the structure of the illumination and the detection. In this case the optical sectioning strength is shown to be up to 25% narrower than in the ideal confocal case.

Liquid crystal director dynamics imaged using two-photon fluorescence microscopy with remote focusing

We introduce a novel imaging technique adopting remote focusing for resolving the axial dynamics in the director field for liquid crystals. The high axial time resolution of our approach is demonstrated by imaging directly the evolution of the director field for an initially splayed nematic layer subject to a sudden voltage pulse. Images of the switching dynamics are presented, revealing transient state director configurations and changes in topology of the liquid crystal layer.