Abundant molecular oxygen in the coma of comet 67P/Churyumov-Gerasimenko.

The composition of the neutral gas comas of most comets is dominated by H2O, CO and CO2, typically comprising as much as 95 per cent of the total gas density. In addition, cometary comas have been found to contain a rich array of other molecules, including sulfuric compounds and complex hydrocarbons. Molecular oxygen (O2), however, despite its detection on other icy bodies such as the moons of Jupiter and Saturn, has remained undetected in cometary comas. Here we report in situ measurement of O2 in the coma of comet 67P/Churyumov-Gerasimenko, with local abundances ranging from one per cent to ten per cent relative to H2O and with a mean value of 3.80 ± 0.85 per cent. Our observations indicate that the O2/H2O ratio is isotropic in the coma and does not change systematically with heliocentric distance. This suggests that primordial O2 was incorporated into the nucleus during the comet's formation, which is unexpected given the low upper limits from remote sensing observations. Current Solar System formation models do not predict conditions that would allow this to occur.

One-week intubation in external dacryocystorhinostomy- a report on long-term outcome.

PURPOSE: The role of silicone stent intubation in dacryocystorhinostomy (DCR) is not clear, and conclusions presented in the literature are contradictory both regarding if intubation should be recommended and if so, the appropriate duration of intubation. This paper reports on the long-term outcome of a comparatively short duration of silicone stent intubation, one week, and discusses the possibility of an optimal duration of intubation where the benefit of the silicone stent is utilized but with minimal risk of complications. METHODS: A total of 70 cases of DCR were followed in 67 patients for four years in a descriptive case series of uncomplicated external DCR with one-week silicone stent intubation. Pre- and perioperative findings, complications, and the need for additional surgery were recorded. At end of follow-up, a questionnaire was sent to the patients asking them to grade the frequency of epiphoric problems. If graded often/constant, a follow-up visit was offered. RESULTS: One patient received additional surgery during follow-up due to persistent epiphora caused by synechiae between the middle turbinate and lateral nasal wall. The response rate to the questionnaire was 88%, with 93% of the respondents reporting epiphora never/seldom. Four patients reported persistent problems: one declined further examination, the tear duct was anatomically patent in two, and one was referred to the ENT department due to inflamed nasal mucosa and extensive adhesions. The long-term functional or anatomical success rate was 97%. CONCLUSIONS: This study shows that a high long-term success rate for uncomplicated DCR is possible with only one-week silicone stent intubation.

Inhibition of NF-kappa B by sodium salicylate and aspirin.

The transcription factor nuclear factor-kappa B (NF-kappa B) is critical for the inducible expression of multiple cellular and viral genes involved in inflammation and infection including interleukin-1 (IL-1), IL-6, and adhesion molecules. The anti-inflammatory drugs sodium salicylate and aspirin inhibited the activation of NF-kappa B, which further explains the mechanism of action of these drugs. This inhibition prevented the degradation of the NF-kappa B inhibitor, I kappa B, and therefore NF-kappa B was retained in the cytosol. Sodium salicylate and aspirin also inhibited NF-kappa B-dependent transcription from the Ig kappa enhancer and the human immunodeficiency virus (HIV) long terminal repeat (LTR) in transfected T cells.

The Toll-receptor family and control of innate immunity.

Innate immune recognition is mediated by a system of germline-encoded receptors that recognize conserved molecular patterns that are associated with microbial pathogens. These receptors are coupled to signal transduction pathways that control expression of a variety of inducible immune-response genes. Toll receptors and the associated signaling pathways of nuclear factor kappaB may represent the most ancient host defense system found in mammals, insects and plants.

Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere.

The origin of cometary matter and the potential contribution of comets to inner-planet atmospheres are long-standing problems. During a series of dedicated low-altitude orbits, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) on the Rosetta spacecraft analyzed the isotopes of xenon in the coma of comet 67P/Churyumov-Gerasimenko. The xenon isotopic composition shows deficits in heavy xenon isotopes and matches that of a primordial atmospheric component. The present-day Earth atmosphere contains 22 ± 5% cometary xenon, in addition to chondritic (or solar) xenon.

Cometary science. 67P/Churyumov-Gerasimenko, a Jupiter family comet with a high D/H ratio.

The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth's oceans. Here, we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the European Space Agency's Rosetta spacecraft, which is found to be (5.3 ± 0.7) × 10(-4)­that is, approximately three times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean-like water.

Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature.

Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in situ measurement of N2 in the Jupiter family comet 67P/Churyumov-Gerasimenko, made by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer aboard the Rosetta spacecraft. A N2/CO ratio of (5.70 ± 0.66) × 10(-3) (2σ standard deviation of the sampled mean) corresponds to depletion by a factor of ~25.4 ± 8.9 as compared to the protosolar value. This depletion suggests that cometary grains formed at low-temperature conditions below ~30 kelvin.

Cometary science. Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko.

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface.

Direct monoclonal antibody rosetting. An effective method for weak antigen detection and large scale separation of human mononuclear cells.

A direct monoclonal antibody rosetting technique is described which serves as a simple, reliable, and very sensitive method for the detection of surface antigens on human leukocytes. In this technique the discriminative monoclonal anti-leukocyte antibodies are directly coupled to ox erythrocytes (oxE) by use of CrCl3. The procedure can be applied to the effective separation of mononuclear cell subsets. By choosing a gradient of appropriate density labeled cells are either isolated in high purity or quantitatively eliminated. This technique proved to be particularly suitable for the large scale purification of autologous or allogeneic bone marrow transplants where either leukemic cells or T cells have to be completely eliminated without damaging sensitive stem cells.

Epiphora as a side effect of topical mitomycin C.

AIM: To report symptoms and findings of lacrimal duct malfunction after topical mitomycin C (MMC) for conjunctival neoplasia. METHODS: 14 consecutive patients treated with 1-6 cycles of topical 0.04% MMC four times daily for periods of 2 weeks were interviewed about symptoms of lacrimal duct malfunction. Patients who complained of tearing had examination of the puncta and canaliculi including probing and lacrimal duct irrigation. RESULTS: Nine patients complained of epiphora after topical MMC. Three of these patients had normal puncta and canaliculi, patent to irrigation. In these patients epiphora ceased spontaneously after probing and irrigation. The additional six patients had stenosis of the punctum (n = 3), the common canaliculus (n = 1), both puncta and both canaliculi (n = 1) and complete occlusion of the lower canaliculus (n = 1). CONCLUSION: Obstruction of the puncta or canaliculi is not an infrequent event after topical 0.04% MMC.

Cut and paste: a no suture, small incision approach to pterygium surgery.

AIM: Evaluation of the benefits of a new technique for pterygium surgery with respect to postoperative pain and surgery time. METHODS: A prospective randomised clinical trial was carried out in 43 patients. 43 eyes were operated for primary nasal pterygium. Autologous conjunctival graft taken at the superotemporal limbus was used to cover the sclera after pterygium excision. After randomisation, in 20 patients the transplant was attached to the sclera with a fibrin tissue adhesive (Tisseel Duo Quick) and in 23 patients with absorbable sutures (7-0 Vicryl Rapid). The Mann-Whitney test was used as statistical analysis. Postoperative pain was graded according to the visual analogue scale (VAS) twice daily during the first week after surgery. Surgery time was noted from the first incision until the lid speculum was removed. RESULTS: The average pain was significantly lower when glue had been used, p<0.05. Average surgery time was 9.7 minutes (range 6-13) for glue and 18.5 minutes (range 12-30) for sutures, p<0.001. No complications occurred. CONCLUSION: Using glue instead of sutures when attaching the conjunctival transplant in pterygium surgery causes significantly less postoperative pain and shortens surgery time significantly.

Polymorphisms of NORs and Heterochromatin in the Horse and Donkey.

Chromomycin A3 (CMA3) banding in mitotic sets of the Equidae horse and donkey were used to demonstrate both constitutive heterochromatin and R-banding. Intra and Interindividual variation In the size of the heterochromatic blocks was observed In many cases. CMA3-posittve telomeric heterochromatin blocks appeared on several chromosomes of the horse and donkey. Some of them were especially spectacular in the donkey. A sequential silver NOR-chromomycin A3/distamycln A-DAPI (CDD) staining procedure led to the detection of the localization of active nucleolus-organizing regions (NORs) and to the identification of chromosomes. The data revealed individual specific NOR patterns in both species.

Pulmonary hemorrhage and immune-complex deposition in the lung. Complications in a patient with systemic lupus erythematosus.

A patient with systemic lupus erythematosus (LE) was admitted with an acute illness characterized by dyspnea, hemoptysis, fever, and diffuse infiltrates revealed by chest roentgenograms. An open-lung biopsy specimen showed massive intrapulmonary hemorrhage, and immunofluorescence and electron microscopic examinations showed granular deposits of IgG within the alveolar walls and pulmonary vessels. Rare, widely scattered foci of infiltration of vessel and alveolar walls by polymorphonuclear leukocytes were also observed. The patient was treated with large doses of prednisone and her condition improved, but she had a second episode of massive hemorrhage eight days after discharge despite maintenance of the prednisone therapy. Her condition again improved over several days, and she has had no pulmonary symptoms for nine months. In some instances, pulmonary hemorrhage in patients with systemic LE may be mediated by polymorphonuclear leukocytes attracted by immune-complex deposits.

Multidrug resistance in human neuroblastoma cells.

Neuroblastoma remains a significant problem in pediatric oncology. Recently a "multidrug-resistance" gene that may cause cells to become resistant to various chemotherapeutic agents has been cloned. The gene encodes the high-molecular-weight plasma membrane protein known as P-glycoprotein. To study the expression of this gene in cells exhibiting the multidrug-resistant phenotype, a panel of sublines selected with several different natural product drugs was established. The drug-sensitive parental BE(2)-C cells were clonally isolated from the human neuroblastoma SK-N-BE(2) line and exhibit a 150-fold increase in the copy number of the N-myc protooncogene. Sublines were selected by stepwise increases in the concentration of actinomycin-D, doxorubicin, vincristine, or colchicine. Gene amplification was assessed using Southern analysis, and RNA levels were determined by Northern and dot-blot analysis. Western blotting was used to determine protein levels. N-myc amplification and expression were simultaneously determined to assess possible alterations associated with development of multidrug resistance. Amplified P-glycoprotein-encoding genes were not seen in control lines but were clearly present in those that had undergone exposure to each of the chemical agents. Similarly, steady-state messenger RNA and protein levels were greatly increased in the drug-resistant sublines. We conclude that human neuroblastoma cells can acquire the multidrug-resistant phenotype after exposure to various chemotherapeutic agents.

Long-term outcome of RPE allografts in non-immunosuppressed patients with AMD.

PURPOSE: To determine the long-term outcome of human retinal pigment epithelium (RPE) transplants in patients with advanced age-related macular degeneration (AMD). METHODS: Using pars plana microsurgical techniques, RPE allografts were transplanted subretinally to four groups of AMD patients: five patients received organized patch transplants after removal of choroidal neovascular membranes, four got small patch transplants in dry AMD; suspensions of RPE cells were transplanted in five cases with dry AMD, and two patients with RPE tears. None received immunosuppression. Transplants were followed for 24-38 months by biomicroscopy, fundus photography, SLO microperimetry, and fluorescein angiography. Rejection was defined as loss of visual function over the transplant, development of an exudative response (subretinal fluid with or without neovascularization), fluorescein leakage, and disruption, depigmentation, or encapsulation of the transplant. RESULTS: Four of 16 transplants (25%) presented no clinical signs of rejection. Three of the four small patch transplants remained pigmented and essentially unchanged after 30-32 months. Clinical signs of graft rejection appeared within three months in all cases of neovascular AMD (disrupted blood-retinal barrier, BRB), but after 6-20 months in five of nine eyes with non-exudative AMD (intact BRB). CONCLUSIONS: Subretinal human RPE allografts present a high rejection rate (75%) without immunosuppression. However, small extrafoveal transplants remained unchanged in shape, size and color for more than two years in non-exudative AMD. A disrupted BRB is likely to enhance graft rejection, which occurs earlier in exudative than in non-exudative AMD.

Surveying.

Several systems for the survey and design for removable partial dentures are based on empiricism and misinformation. Presented here is a systematic approach to the basic requirements for precribing a prosthesis that will be received favorably by the patient.

Cytogenetic characterization of the Madin-Darby bovine kidney cell line.

The permanent bovine cell line, Madin-Darby bovine kidney, was cytogenetically analyzed. Chromosomal staining indicated 52 metaphase chromosomes with variations from 49 to 54. The isochromosomes 5, 12, and 13, and centric fusions between chromosomes 1 and 26, 9 and 11, 9 and 24, 17 and 25, 18 and 23, 20 and 24, and 24 and 27 were considered marker chromosomes.

[A child with hyperpyrexia syndrome and multiple organ failure caused by and an orthopedic corset]. / Een kind met hyperpyrexiesyndroom en multi-orgaanfalen door een orthopedisch korset.

A 4-year-old boy who each night was placed in an orthopaedic corset because of congenital multiple arthrogryposis developed heat stroke with hyperpyrexia and multiorganic failure in a hot summer. Treatment consisted of administration of fluids, antibiotics and anticonvulsive agents; the child recovered completely. In children who are sick and have fever, the use of such corsets should temporarily be suspended.

Polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and "novel" brominated flame retardants in house dust in Germany.

Brominated flame retardants (BFRs) are used in a wide variety of products such as electronic devices, upholstery and carpets and in insulation boards. The study presented here aimed to quantify the amounts of BFRs in house dust in Germany. For this purpose 20 residences' dust samples were collected from vacuum cleaner bags and analysed with LC-MS/MS and simultaneously with GC/MS. Using GC/MS, the median (95th percentile) concentrations of PBDEs (sum of tetra- to hepta-congeners), BDE 209, Σ-HBCD (sum of three congeners), and decabromodiphenylethane (DBDPE) were 42ng/g (230ng/g), 950ng/g (3426ng/g), 335ng/g (1545ng/g), and 146ng/g (1059ng/g), respectively. Using LC-MS/MS some "novel" flame retardants were found in median concentrations of 343ng/g (bis(2-ethyl-1-hexyl)tetrabromophthalate, TBPH), and 28ng/g (tetrabromobisphenol A, TBBPA). Whilst 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) and 2-ethyl-1-hexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) could not be detected. Based on these measurements an exposure assessment for the sum of tetra- to heptabrominated congeners, BDE 209, and Σ-HBCD resulted in a "high" daily intake for toddlers (based on 95th percentiles) of 1.2ng/kg b.w., 0.69ng/kg b.w., and 8.9ng/kg b.w., respectively. For TBPH the "high" intake was calculated at 4.1ng/kg b.w. and for DBDPE at 5.3ng/kg b.w. A clear tendency was observed to apply "novel" BFRs in Germany. Moreover, the results suggest that the recent exposure to PBDEs and HBCD via house dust in Germany is well below the levels that are associated with health effects. For the "novel" brominated flame retardants such an assessment is not possible due to limited toxicological information.

Analysis of common and emerging brominated flame retardants in house dust using ultrasonic assisted solvent extraction and on-line sample preparation via column switching with liquid chromatography-mass spectrometry.

Brominated flame retardants (BFRs) are persistent and widespread chemicals. Therefore human beings are exposed to BFRs. House dust may be one source of exposure and contains a lot of xenobiotics in relatively high concentrations. In contrast to common GC-MS based methods here an online LC-MS/MS method is presented to quantify 16 BFRs in dust using ultrasonic solvent extraction as a single sample work up step. LOQ from 0.6 (tetrabromobisphenol A) to 80 (polybrominated diphenylethers (BDE 28) ng/g dust were achieved. Data for accuracy, precision and recovery are presented and are comparable to common LC-MS/MS methods in different matrices. In addition 5 real house dust samples were analyzed with high concentration (535 ng/g) for bis(2-ethyl-1-hexyl)tetrabromophthalate which is a novel alternative BFRs to replace common BDE's.