Extended Detection Window for Gamma-Hydroxybutyrate in the Urine of an Elderly Woman.

Gamma-hydroxybutyrate (GHB) is a central nervous system depressant that has gained popularity as an illicit recreational drug. We describe a case of an elderly woman who was found unconscious in her home. The paramedics initially suspected an intracranial incident. A head computed tomography was negative, as was the initial urinary drug screening. The diagnosis of GHB intoxication was made with the detection of GHB in a urine sample obtained 28-29 hours after the assumed time of intake. Our case underscores the importance of considering drug testing in a broad range of patients and shows that elderly patients may have an extended detection window of GHB.

Laser wakefield acceleration based x ray source using 225-TW and 13-fs laser pulses produced by thin film compression.

We show that 13-fs laser pulses associated with 225 TW of peak power can be used to produce laser wakefield acceleration (LWFA) and generate synchrotron radiation. To achieve this, 130-TW high-power laser pulses (3.2 J, 24 fs) are efficiently compressed down to 13 fs with the thin film compression (TFC) technique using large chirped mirrors after propagation and spectral broadening through a 1-mm-thick fused silica plate. We show that the compressed 13-fs laser pulse can be properly focused even if it induces a 10% degradation of the Strehl ratio. We demonstrate the usability of such a laser beam. We observe both an increase of the electron energy and of the betatron radiation critical energy when the pulse duration is reduced to 13 fs compared with the 24-fs case.

X-ray phase contrast imaging of spherical capsules.

We demonstrate that a laser-based synchrotron X-ray source can be used to image and characterize in a single laser shot spherical capsules similar to ICF targets. Thus, we establish this source potential for real-time ultrafast imaging of the ICF laser driver interaction with the target. To produce the X-ray beam we used a 160 TW high power laser system with 3.2 J and 20 fs incident on a supersonic gas jet target at 2.5 Hz repetition rate. We produced 2.7 × 109 photons/0.1% BW/sr/shot at 10 keV with a critical energy Ec = 15.1 keV. In our experimental conditions the spatial resolution was 4.3 µm in the object plane. We show that it is feasible to image the capsule structure and experimentally retrieve the phase information.

Laser-based synchrotron X-ray radiation experimental scaling.

We review the results obtained in several experimental campaigns with the INRS high-power laser system and determine the X-ray emission scaling from synchrotron radiation produced during laser wakefield acceleration (LWFA) of electrons. The physical processes affecting the generation of intense and stable X-ray beams during the propagation phase of the high-intensity ultrashort pulse in the gas jet target are discussed. We successfully produced stable propagation in the gas jet target of a relativistic laser pulse through self-guiding on length larger than the dephasing and depletion lengths, generating very intense beams of hard X-rays with up to 200 TW on target. The experimental scaling law obtained for the photon yield in the 10-40 keV range is presented and the level of X-ray emission at the 1 PW laser peak power level, now available at several laser facilities, is estimated.

Undulator beamline of the Brockhouse sector at the Canadian Light Source.

The Brockhouse project at the Canadian Light Source plans the construction of three beamlines, two wiggler beamlines, and one undulator beamline, that will be dedicated to x-ray diffraction and scattering. In this work, we will describe the undulator beamline main components and performance parameters, obtained from ray tracing using XOP-SHADOW codes. The undulator beamline will operate from 4.95 to 21 keV, using a 20 mm period hybrid undulator placed upstream of the wiggler in the same straight section. The beamline optics design was developed in cooperation with the Brazilian Synchrotron - LNLS. The beamline will have a double crystal monochromator with the options of Si(111) or Si(311) crystal pairs followed by two mirrors in the KB configuration to focus the beam at the sample position. The high brilliance of the undulator source will produce a very high flux of ~10(13) photons/s and high energy resolution into a small focus of 170 µm horizontal and 20-60 µm vertical, depending on the optical configuration and energy chosen. Two multi-axis goniometer experimental stations with area detectors and analyzers are foreseen to enable diffraction, resonant and inelastic scattering experiments, and SAXS/WAXS experiments with high resolution and time resolving capabilities.

Waterborne norovirus outbreak in a municipal drinking-water supply in Sweden.

During Easter 2009, almost 200 people resident in a small Swedish village fell ill with gastrointestinal symptoms. We conducted a retrospective cohort study and a molecular investigation in order to identify the source of the outbreak. Residents living in households connected to the public water network were at an increased risk of developing disease (relative risk 4·80, 95% confidence interval 1·68-13·73) compared to those with no connection to the public network. Norovirus genotype GI.3 was identified in stool samples from six patients and in a sample from the public water network. Contamination of one of the wells supplying the public water network was thought to be the source of the outbreak. This is a description of a norovirus outbreak linked to a municipal drinking-water supply in Sweden. Information from epidemiological and molecular investigations is of utmost importance to guide outbreak control measures and to prevent future outbreaks.

In vitro Th2 deviation of myelin-specific peripheral blood lymphocytes from patients with multiple sclerosis.

This study aimed at investigating if selective ex vivo immune deviation of myelin-specific cytokine secretion towards Th2 is possible in blood cells from patients with multiple sclerosis (MS). Interleukin (IL)-4 (Th2) and interferon-gamma (Th1) secreting cells were recorded by ELISPOT in 13 MS patients. Deviation was successful in 10 patients. Interleukin-4 alone was most effective in inducing myelin-specific immune deviation in MS patients whereas IL-1 or IL-15 in combination with IL-4 did not improve the results. Further studies and improvements are needed before ex vivo immune deviation can be considered a potential treatment in patients with MS.

Graves' ophthalmopathy: I. Simple CT estimates of extraocular muscle volume.

Graves' ophthalmopathy is an autoimmune inflammatory process affecting primarily the extraocular muscles. The enlargement of these muscles is responsible for most of the important manifestations of the disease, including proptosis, lid retraction, diplopia, and optic neuropathy. Recently the optic neuropathy has been shown to correlate with extraocular muscle volume as determined by computed tomography (CT). In the present study simplified measures of the extraocular muscles imaged by CT are described, which also correlate highly with the development of optic neuropathy.

Graves' ophthalmopathy: III. Effect of transantral orbital decompression on optic neuropathy.

Twenty-five patients (48 eyes) underwent transantral, surgical decompression of their orbits for treatment of Graves' ophthalmopathy with optic neuropathy. Visual acuity improved in 77%, remained unchanged in 17%, and worsened in 6%. Colour vision improved in 76%, remained unchanged in 20%, and worsened in 4%. Visual fields improved in 67%, remained unchanged in 12%, and worsened in 22%. In general the worse the vision preoperatively the greater the relative improvement postoperatively. Clinical and radiological findings failed to correlate with visual outcome of surgical intervention. The study shows surgery to be highly effective in restoring optic nerve function for patients with severe Graves' ophthalmopathy.

Graves' ophthalmopathy: II. Correlation of clinical signs with measures derived from computed tomography.

Quantitative clinical and computed tomographic (CT) measures of Graves' ophthalmopathy were obtained in 76 patients. Significant correlation of several CT parameters of the mid-orbital axial CT slice with optic nerve involvement was established. By means of clinical measures, only limitation of ocular motility was found to correlate with the optic neuropathy. The results suggested that there were two distinct populations of patients with Graves' disease which could be segregated by CT scan and clinical evaluation, one which developed optic neuropathy and one which did not. Therefore simple measures performed on the mid-orbital slice of the CT scan are recommended for all patients with Graves' ophthalmopathy as an important adjunct to careful evaluation of extraocular muscle function, in order to identify patients at risk of developing optic neuropathy.

The frequency of digital and endoscopic examination of the rectum before radiological barium enema.

Doctor's delay in patients with rectal carcinoma is common with a frequency between 30% and 60%. The reason for delay has been supposed to be the neglectance to perform digital examination and rigid proctosigmoidoscopy in patients with symptoms of anorectal disease. Especially general practitioners have been blamed for a high percentage of this kind of doctor's delay. In this study 300 consecutive patients referred for radiological examination of the large bowel have been questioned if digital examination and rigid proctosigmoidoscopy have been performed by their referral doctor. The results show that in 19% of the cases neither digital nor proctosigmoidoscopic examination had been performed. Rigid proctosigmoidoscopy had been omitted in 44%. No statistical difference was observed in the frequency of digital examination between general practitioners (79%) and hospital doctors (84%). The low figures, both for digital examination and rigid proctosigmoidoscopy are probably causing many patients a delay in the diagnosis of a rectal carcinoma. Thus, a more intense evaluation in this area should be applied in the medical faculties and also at post graduate courses.

Modified technique in the dorsal approach in total hip arthroplasty.

A modified dorsal approach with osteotomy of a bone shell with the attached short external rotator muscles which are resutured, is described. The advantages have been less dislocations, less sciatic nerve injuries, and an increased operative access. There have been no disadvantages, as increased bleeding or periarticular calcification. The dorsal approach can be used for all conventional total hip arthroplasties and the reported modification seems to be an advantage.