Cystamine/cysteamine rescues the dopaminergic system and shows neurorestorative properties in an animal model of Parkinson's disease.

The neuroprotective properties of cystamine identified in pre-clinical studies have fast-tracked this compound to clinical trials in Huntington's disease, showing tolerability and benefits on motor symptoms. We tested whether cystamine could have such properties in a Parkinson's disease murine model and now provide evidence that it can not only prevent the neurodegenerative process but also can reverse motor impairments created by a 6-hydroxydopamine lesion 3 weeks post-surgery. Importantly, we report that cystamine has neurorestorative properties 5 weeks post-lesion as seen on the number of nigral dopaminergic neurons which is comparable with treatments of cysteamine, the reduced form of cystamine used in the clinic, as well as rasagiline, increasingly prescribed in early parkinsonism. All three compounds induced neurite arborization of the remaining dopaminergic cells which was further confirmed in ex vivo dopaminergic explants derived from Pitx3-GFP mice. The disease-modifying effects displayed by cystamine/cysteamine would encourage clinical testing.

Clinicopathologic predictors of lymph node metastasis in breast cancer patients according to molecular subtype.

PURPOSE: We present a large institutional study to determine factors predictive of axillary lymph node (LN) metastasis in breast cancer according to molecular subtype. METHODS: We conducted a retrospective analysis of our prospectively maintained breast cancer database study using data from of women managed from January 2009 through December 2013. Clinicopathologic characteristics were correlated with lymph node status and outcome according to breast cancer molecular subtyping. RESULTS: LN metastases were detected in 464 (32.1%) of 1444 women with breast cancer. By multivariate analysis, independent factors predictive of LN involvement were: for the luminal A subtype (n=776): tumour size: OR=1.05 [95% CI: 1.03-1.07] P<0.0001; lymphovascular invasion: OR=3.06 [95% CI: 1.80-5.20] P<0.0001 and tumour grade: OR=1.65 [95% CI: 1.07-2.58] P=0.026. For luminal B subtype (n=441): age: OR=0.97 [95% CI: 0.95-0.99] P=0.004; tumour size: OR=1.03 [95% CI: 1.01-1.05] P=0.002; lymphovascular invasion: OR=3.21 [95% CI: 1.92-5.44] P<0.0001; inflammatory breast cancer: OR=12.36 [95% CI: 2.18-243.3] P=0.019. For the HER2 subtype (n=72): lymphovascular invasion: OR=7.87 [95% CI: 2.10-35.2] P=0.003. For the triple negative subtype (n=155): parity: OR=1.53 [95% CI: 1.10-2.25] P=0.02; tumour size: OR=1.03 [95% CI: 1.01-1.05] P=0.002 and lymphovascular invasion: OR=7.13 [95% CI: 2.46-22.8] P=0.00048. CONCLUSION: This retrospective study provides valuable insight into LN involvement of patients with primary breast cancer according to molecular subtyping.

[Outcomes of patients with breast cancer in function of their body mass index]. / Indice de masse corporelle et facteurs pronostiques du cancer du sein.

OBJECTIVE: The aim of this study was to evaluate outcomes of patients with breast cancer in function of the body mass index (BMI). METHODS: The study cohort consisted of consecutive women undergoing surgery for breast cancer in our institution between January 2009, and September 2013. Individual records of all patients were reviewed and analyzed. Patient BMI was categorized as underweight, normal, overweight and obese. RESULTS: A total of 1599 patients were evaluated. Patients were followed for one to 265months with a mean of 36.4months. The number of patients in each of the BMI categories was 66, 779, 463 and 291 for underweight, normal, overweight and obese women respectively. Women with higher BMI were more frequently affected by hypertension (18, 21, 35 and 47% respectively, P<0.0001) and diabetes (3, 2, 7 and 7% respectively, P<0.0001). Obese women had more frequently an inflammatory presentation (P=0.006), larger tumour size (P=0.038) and axillary lymph node involvement (P=0.03) with much more positive lymph nodes (P=0.02). Patients had the same protocols of treatment (surgery and adjuvant treatment). There was no statistically significant difference in overall 5-years survival between groups (P=0.30). CONCLUSIONS: Our study demonstrate a more aggressive clinical and histological presentation for obese women with breast cancer.

[Orbital infections in children: clinical signs, imaging, and treatment]. / Infections orbitaires de l'enfant : clinique, imagerie et traitement.

Orbital infections are rare in children. The more posterior the abscess has spread, the more serious it is, with potential intracranial complications. The main etiology is sinusitis, whose location depends on age. The diagnosis is based on clinical examination and CT or MRI. Intravenous antibiotics alone or associated with surgical drainage (for children older than 9 years or those with complications) are performed. Orbital infections in children require good collaboration between ophthalmologists, otolaryngologist, and pediatricians.

Diffusers in silicon-photodiode radiometers.

The problems encountered when making radiometric measurements with silicon-photodiode radiometers not incorporating diffusers are discussed, with special attention given to the case where laser beams are involved. A diffuserless radiometer head design is presented which eliminates most of these problems. These problems can also be avoided by using a diffuser. A radiometer head incorporating a diffuser is described, and its properties are studied for three types of diffuser: flashed opal, type-2250 translucent Plexiglas, and a three-piece ground and etched quartz. Graphical data are given for the spatial uniformity, angular response variation, and spectral attenuation associated with radiometer heads incorporating these three types of diffuser. It is shown that, for a wide range of radiometric and photometric applications, the quartz diffuser is the most desirable, although its use results in a somewhat limited angular field of view.

Calibration of incandescent lamps for spectral irradiance by means of absolute radiometers.

A method for calibrating incandescent lamps for spectral irradiance by means of absolute radiometers is described in which a secondary radiometer is calibrated spectrally against absolute radiometers and then used in conjunction with a series of filters to calibrate the lamps. Considering both narrowband and wideband filters, an extensive mathematical error analysis is performed. The use of narrowband filters (20-25-nm halfwidth) is found to be advantageous because very little information is required on the spectral distribution of the lamp being measured. The most serious source of error is a wavelength shift in the measured spectral transmittances of the filters, especially at shorter avelengths; for example, at 400 nm, a wavelength shift error of 1 nm can cause an error approaching 3%. It is estimated that the accuracy of spectral irradiance measurements made using the method described here will vary between +/-1 and +/-0.5% from ~350 to 800 nm. Measurements on 500-W quartz-bromine spectral irradiance standards are described. With such lamps, only four or five narrowband filters are required to cover the spectral range from the near UV to the near IR. The measured and calibration values agreed to ~ +/-0.5% on average with a maximum difference of ~1%.

Reduction of diffraction errors in radiometry by means of toothed apertures.

Purcell and Koomen have shown [J. D. Purcell and M. J. Koomen, Coronagraph with Improved Scattered-Light Properties, Report of NRL Progress, 1962 (U.S. GPO, Washington, D.C., 1962)] that a toothed occulting disk greatly reduces diffraction problems in coronagraphy. In the present paper, the use of toothed apertures to reduce diffraction errors in radiometry is studied in detail. Simple formulas are derived which allow the design of toothed apertures for given applications. Experimental measurements are presented which demonstrate the usefulness of toothed apertures to reduce diffraction errors by at least an order of magnitude. This technique is shown to be particularly useful for radiometric measurements involving a series of apertures; in such cases, the diffraction errors of the individual apertures can simply add up, resulting in important over-all errors if ordinary circular apertures are used.

Thin-Film Laser-to-Fiber Coupler.

A laser-to-fiber coupler is described in which a thin-film waveguide is used to focus an incoming laser beam into the core of a cladded fiber. The latter is accurately aligned with respect to the waveguide by means of a V channel produced by a differential etching technique. Although over-all coupling efficiencies have not exceeded 10% so far, it is estimated that efficiencies of 50% or more should be feasible. This type of coupler may be useful in applications where compactness, ruggedness, and low cost are important.

Properties of Indium Antimonide Detectors for use as Transfer Standards for Detector Calibrations.

The properties of 4-mm-diameter and 7-mm-diameter liquid-nitrogen-cooled indium antimonide detectors were investigated to determine their suitability as transfer standards (i.e., reference detectors) for the detector calibration facility at the National Research Council of Canada. The spectral responsivity of the InSb detectors in the spectral range 1000-3000 nm was determined by atwo-step procedure involving the use of germanium transfer standardsand suitably characterized thermopiles. It is shown that thelong-term reproducibility of the InSb detector calibrations is approximately ?1%. The uniformity and linearity as a function of wavelength, as well as the background current noise and drift of thetwo detectors, are compared. It is shown that the 7-mm-diameter detector is clearly superior to the 4-mm one for use as a transfer standard. It is estimated that the overall accuracy of the calibrations of the two InSb detectors is ?2% in the range 1200-2800 nm.

Diffraction corrections in the radiometry of extended sources.

The diffraction corrections associated with a circular aperture in the case of an extended source and a detector located in the fully illuminated region have been calculated in 1972 by Steel, De, and Bell. We have shown recently that the intensity distribution formula that they have used is not accurate in the central region of the diffraction pattern and greatly underestimates the diffraction corrections associated with a point source. In this paper, we take up the case of an extended source; we have followed Steel et al.'s method of calculation, but have used an intensity distribution which we have shown to be valid in the central region. We show that in the case of complex radiation, the variation of the diffraction correction with the source radius rho takes a very simple form: the diffraction correction remains approximately constant as rho increases, until the source and detector subtend equal angles at the center of the aperture; if rho is increased further, the diffraction correction decreses linearly with 1/rho over a certain range of rho. Experimental results are presented that confirm these theoretical predictions.

Diffraction losses associated with tungsten lamps in in absolute radiometry.

The diffraction losses associated with absolute radiometers were calculated for the case where the source is a tungsten lamp used with a long wavelength suppressing filter. The calculations were done using Blevin's treatment, which assumes a point source and a single diffracting aperture. We have shown that this treatment is sufficiently accurate for a typical absolute radiometer configuration. The calculations were done for color temperatures in the 1600-3200 K range for three typical glass filters.

Diffraction corrections in radiometry: comparison of two different methods of calculation.

We have studied the effect of diffraction on the flux received by a detector located in the fully illuminated region cast by a circular aperture which is placed between a point source and the detector. This case was studied previously by Steel, De, and Bell, who have derived a diffraction correction formula based on an intensity distribution approximation due to Focke. We have derived a diffraction correction formula based on a different type of approximation. The corrections predicted by this formula are much greater than those predicted by Steel et al.'s formula. The validity of our formula and reasons for the discrepancy between the two methods are discussed; some supporting experimental evidence is presented. The case of complex radiation is discussed; it is shown that, under certain conditions, the calculation of diffraction cor rections is very simple.

Multiple imaging using various types of simple phase gratings.

Diffraction gratings can be used to form multiple images in optical systems utilizing incoherent, monochromatic light. The properties of two-dimensional phase gratings having periodic rectangular, sinusoidal, or triangular surface corrugation have been investigated. It is shown that these gratings can be used to form an array of equally intense images by an optical cascading process, each step in the cascade increasing the number of images by a factor of 9. These simple gratings would be particularly useful for forming relatively small numbers of large images. The efficiency per step would be between 70% and 80% and the distortion less than 2%. If spatially incoherent laser light is used, the resolution and general image quality would be limited mainly by the lenses used. These conclusions are corroborated by experimental results obtained with rectangular-type phase gratings.

Radiometric errors caused by diffraction from circular apertures: edge effects.

The diffraction corrections associated with a circular aperture are calculated for the case of a point source and a detector aperture having a diameter approximately equal to that of the illuminated region. This investigation is made for monochromatic and complex (tungsten) radiation; two types of detectors are considered: a typical silicon diode and a neutral detector. The intensity distribution near the edge is calculated for the same cases. Some experimental results are also presented to corroborate the calculations and to suggest the behavior with extended sources. We show that strong diffraction effects are present close to the shadow edge even with a source-detector combination having a very extended wavelength band. In radiometric measurements, a suitable compromise between diffraction effects, stray light, and vignetting effects can be achieved by having the detector aperture diameter approximately half that of the illuminated region. An extended source will reduce diffraction effects. Finally, some suggestions are made with respect to making diffraction corrections for a series of apertures.

Spectral responsivity of various types of silicon photodiode at oblique incidence: comparison of measured and calculated values.

The spectral responsivity of several types of silicon photodiode at oblique incidence (approximately 45 degrees) is investigated. Both windowless diodes and diodes that incorporate quartz windows are considered. The spectral responsivities are measured directly for both parallel and perpendicular polarized radiation. For comparison, the responsivity at oblique incidence is also calculated from the normal-incidence measured responsivity in conjunction with the reflectance values at normal and oblique incidence calculated from thin-film theory by use of the measured oxide thicknesses of the diodes and published data on the refractive indices of silicon and fused silica. A technique, believed to be novel, is described for accurately measuring the oxide thicknesses of the diodes. A comparison of calculated and measured responsivity values shows that, when imperfect polarizers are used, it may be more accurate over a certain spectral range to calculate the responsivities at oblique incidence rather than to measure them directly. The additional uncertainty associated with the calculated responsivity values at oblique incidence, with respect to the original source data for normal incidence, is +/-1% over a wide spectral range.

Raman-noise limit on squeezing in continuous-wave four-wave mixing.

The continuous-time quantum theory of self-phase modulation (SPM) in lossless, dispersionless, single-mode fiber requires a nonzero response time, to capture the classical SPM limit properly, and an accompanying Raman noise, to ensure commutator preservation. The continuous-wave, four-wave mixing limit of this theory is shown to harbor a Raman-noise limit on fiber-based squeezed-state generation.

Realization of a spectral irradiance scale in the near infrared at the National Research Council of Canada.

The measurements involved in the realization of a spectral irradiance scale in the near IR are described. Interference filters were used in conjunction with absolute radiometers to calibrate two different types of tungsten-halogen lamp at nine discrete wavelengths in the spectral range of 700-1600 nm. We discuss various aspects of these measurements: the apparatus used and alignment procedures, aging of the lamps and verification of their spectral characteristics, filter properties and measurements, some of the problems associated with the radiometric measurements, and data analysis. In particular it is shown that the interpolation formulas used to obtain spectral irradiance values at other wavelengths must be carefully chosen to avoid spurious errors. Two independent realizations were made; a comparison of the results obtained in the two cases indicated that some of the lamps had anomalous behavior. Finally it is shown that the new scale is in agreement with the scales realized by several other national laboratories within estimated uncertainties.

chi((3)) squeezed vacuum generation without a Sagnac interferometer.

We show that an intense linearly polarized pulse propagating in a nonbirefringent fiber squeezes the perpendicularly polarized vacuum f luctuations through cross-phase modulation. Unlike the generation of squeezed vacuum through self-phase modulation, the mechanism discussed here does not require the use of a nonlinear Sagnac interferometer to separate the pump from the squeezed vacuum.

Electrically calibrated radiometer using a thin film thermopile.

The fabrication and principal characteristics of an electrically calibrated absolute radiometer are described. The receiver substrate incorporates an evaporated chromium-nickel thermopile, an electrical shield, a copper thermal diffuser disk, an evaporated chromium electrical heating element, and a goldblack absorber. All insulating layers are evaporated silicon monoxide; the thermopile and heater are made by a photoetching process. The performances of several radiometers are discussed. For example, a 28-junction version has a responsivity and NEP of 93 mV/W and 50 nW, respectively, in air, with a time constant of 15 sec and a surface responsivity uniform to better than 1%. The radiometers require only a few corrections of small magnitude. An analysis of sources of error and residual uncertainties shows that the over-all precision of this type of radiometer is at least 0.5% for a power level of 50 microW. Comparative radiometric measurements are described that support this claim.