Vitamin D-induced hypercalcaemia and acute kidney injury in sarcoidosis.

Vitamin D deficiency is relatively common, and its management in patients with sarcoidosis is challenging due to the risk of hypercalcaemia. Our patient had an autologous stem cell transplant for multiple sclerosis and was given high-dose vitamin D concurrently with immunosuppressive therapy. The patient subsequently presented with symptomatic hypercalcaemia and an acute kidney injury. A clinical and biochemical recovery was reached by withdrawing vitamin D and administering intravenous fluids. Interestingly, new evidence suggests that activated vitamin D can actually dampen the inflammatory process in sarcoidosis, and this was reflected in a reduction of our patient's serological markers of sarcoidosis activity. One large study found no significant risk of hypercalcaemia when low doses of vitamin D were used in sarcoidosis. Where indicated, and until clear guidelines are established, we suggest using low doses of vitamin D with cautious monitoring of calcium and renal function.

Pneumonia caused by toxic epidermal necrolysis.

A well-functioning 68 year old gentleman presented to our hospital with a macular rash 2 weeks after starting a course of Ciprofloxacin. There was rapid progression of skin involvement including the mucosa, complicated by pancytopaenia. Toxic Epidermal Necrolysis (TEN) was suspected and the patient was administered intravenous immunoglobulins and granulocyte colony stimulating factor. TEN was confirmed on skin biopsy and a lymphocyte transformation test demonstrated sensitisation to Ciprofloxacin. The patient developed multifocal pulmonary infiltrates with evidence of pulmonary involvement and probable pneumonia after 1 week and was treated with broad spectrum antibiotics. He also became dysphagic and suffered recurrent aspiration pneumonias. Follow up studies revealed fixed airways obstruction and features of bronchiolitis on computed tomography. This case highlights pulmonary involvement which can become a chronic complication of TEN, itself precipitated by the rare drug cause of Ciprofloxacin.

Effects of non-invasive respiratory support on gas exchange and outcomes in COVID-19 outside the ICU.

Non-invasive respiratory support (NRS) outside of the ICU has played an important role in the management of COVID-19 pneumonia. There is little data to guide selection of NRS modality. We present outcomes of NRS outside the ICU and discuss the effects of NRS on gas exchange with implications for management.

Dependence of the damage in optical metal/dielectric coatings on the energy of ions in irradiation experiments for space qualification.

Terrestrial accelerator facilities can generate ion beams which enable the testing of the resistance of materials and thin film coatings to be used in the space environment. In this work, a [Formula: see text]/Al bi-layer coating has been irradiated with a [Formula: see text] beam at three different energies. The same flux and dose have been used in order to investigate the damage dependence on the energy. The energies were selected to be in the range 4-100 keV, in order to consider those associated to the quiet solar wind and to the particles present in the near-Earth space environment. The optical, morphological and structural modifications have been investigated by using various techniques. Surprisingly, the most damaged sample is the one irradiated at the intermediate energy, which, on the other hand, corresponds to the case in which the interface between the two layers is more stressed. Results demonstrate that ion energies for irradiation tests must be carefully selected to properly qualify space components.

Systematic Review and Meta-Analysis on the Influence of Surgeon Specialization on Outcomes Following Appendicectomy in Children.

The aim of this study is to assess the influence of surgeon specialization on outcomes following appendicectomy in children.General surgeons and pediatric surgeons manage appendicitis in children; however, the influence of subspecialization on outcomes remains unclear.Two authors searched Medline and Embase to identify relevant studies. Eligible studies were comparative and provided data on children who had appendicectomy while under the care of general or pediatric surgical teams. Two authors initially screened titles and abstracts and then full text manuscripts were evaluated. Data were extracted by 2 authors using an electronic spreadsheet. Pooled risk ratios and pooled mean differences were used in analyses.We identified 9 relevant studies involving 50,963 children who were managed by general surgery teams and 15,032 children who were managed by pediatric surgery teams. A normal appendix was removed in 4660/48,105 children treated by general surgery units and in 889/14,760 children treated by pediatric units (pooled risk ratio 1.79; 95% confidence interval [CI] 1.26-2.54; P = 0.001). Children managed in general units had shorter mean hospital stays compared with children managed in pediatric units (pooled mean difference -0.70 days; 95%CI -1.09 to -0.30; P = 0.0005). There were no significant differences regarding wound infections, intra-abdominal abscesses, readmissions, or mortality.We found that children who were managed by specialized pediatric surgery teams had lower rates of negative appendicectomy although mean length of stay was longer. Our article is based upon a group of heterogeneous and mostly retrospective studies and therefore there is little external validity. Further studies are needed.

Digital holographic interferometry with CO2 lasers and diffuse illumination applied to large space reflector metrology [Invited].

Digital holographic interferometry in the long-wave infrared domain has been developed by combining a CO(2) laser and a microbolometer array. The long wavelength allows large deformation measurements, which are of interest in the case of large space reflectors undergoing thermal changes when in orbit. We review holography at such wavelengths and present some specific aspects related to this spectral range on our measurements. For the design of our digital holographic interferometer, we studied the possibility of illuminating specular objects by a reflective diffuser. We discuss the development of the interferometer and the results obtained on a representative space reflector, first in the laboratory and then during vacuum cryogenic test.

Terahertz profilometry at 600 GHz with 0.5 microm depth resolution.

Characterization of the topography of materials by interferometry in the visible or near-IR wavelength regime becomes difficult or impossible if the surface is rough on the length scale of a tenth of the wavelength and more. In this case, THz radiation can provide an interesting alternative. We demonstrate heterodyne profilometry at 600 GHz as a method for the accurate determination of surface topography with an achievable expanded standard uncertainty of 0.5 mum.

Refractive-index changes caused by proton radiation in silicate optical glasses.

We have studied experimentally, by using a differential interferometric technique, the effect of proton radiation on the refractive index of commercial (Schott) silicate crown glasses, BK7 and LaK9, and their radiation-resistant counterparts. The strongest effect was observed for the radiation-hard lanthanum crown LaK9G15: At a 0.65-Mrad dose the index change was approximately 3 x 10(-5). Radiation-hard glasses are used in optical systems operating in radiation environments because they prevent spectral transmission degradation in the visible. However, such glasses are not protected against radiation-induced refractive-index perturbations, and a diffraction-limited optical system based on such glasses may fail owing to radiation-induced aberrations.