127 research outputs found

    High mortality associated with an outbreak of hepatitis E among displaced persons in Darfur, Sudan

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    BACKGROUND: Hepatitis E virus (HEV) causes acute onset of jaundice and a high case-fatality ratio in pregnant women. We provide a clinical description of hospitalized case patients and assess the specific impact on pregnant women during a large epidemic of HEV infection in a displaced population in Mornay camp (78,800 inhabitants), western Darfur, Sudan. METHODS: We reviewed hospital records. A sample of 20 clinical cases underwent laboratory confirmation. These patients were tested for immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody to HEV (serum) and for amplification of the HEV genome (serum and stool). We performed a cross-sectional survey in the community to determine the attack rate and case-fatality ratio in pregnant women. RESULTS: Over 6 months, 253 HEV cases were recorded at the hospital, of which 61 (24.1%) were in pregnant women. A total of 72 cases (39.1% of those for whom clinical records were available) had a diagnosis of hepatic encephalopathy. Of the 45 who died (case-fatality ratio, 17.8%), 19 were pregnant women (specific case-fatality ratio, 31.1%). Acute hepatitis E was confirmed in 95% (19/20) of cases sampled; 18 case-patients were positive for IgG (optical density ratio > or =3), for IgM (optical density ratio >2 ), or for both, whereas 1 was negative for IgG and IgM but positive for HEV RNA in serum. The survey identified 220 jaundiced women among the 1133 pregnant women recorded over 3 months (attack rate, 19.4%). A total of 18 deaths were recorded among these jaundiced pregnant women (specific case-fatality ratio, 8.2%). CONCLUSIONS: This large epidemic of HEV infection illustrates the dramatic impact of this disease on pregnant women. Timely interventions and a vaccine are urgently needed to prevent mortality in this special group

    RX J1643.7+3402: a new bright cataclysmic variable

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    We report the discovery of a new bright (V\sim12.6) cataclysmic variable star identified with the ROSAT X-ray source RX J1643.7+3402. Spectroscopic and photometric observations show it to be a novalike variable sharing some of the characteristics of the SW Sex sub-class of novalike CVs. The spectroscopic period may be either 2\fh575 or 2\fh885, within the period "gap." A photometric modulation with a probable period of 2\fh595 and an amplitude of \sim 0.1 mag in V is present on most nights and could be either a "positive" or a "negative" superhump modulation (depending on the exact spectroscopic period), indicating the presence of a precessing accretion disk in this system. Rapid variations of 0.1 to 0.2 mag amplitude in V repeat with a time scale of \sim 15 min

    Confirmation of SBS 1150+599A As An Extremely Metal-Poor Planetary Nebula

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    SBS 1150+599A is a blue stellar object at high galactic latitude discovered in the Second Byurakan Survey. New high-resolution images of SBS 1150+599A are presented, demonstrating that it is very likely to be an old planetary nebula in the galactic halo, as suggested by Tovmassian et al (2001). An H-alpha image taken with the WIYN 3.5-m telescope and its "tip/tilt" module reveals the diameter of the nebula to be 9.2", comparable to that estimated from spectra by Tovmassian et al. Lower limits to the central star temperature were derived using the Zanstra hydrogen and helium methods to determine that the star's effective temperature must be > 68,000K and that the nebula is optically thin. New spectra from the MMT and FLWO telescopes are presented, revealing the presence of strong [Ne V] lambda 3425, indicating that the central star temperature must be > 100,000K. With the revised diameter, new central star temperature, and an improved central star luminosity, we can constrain photoionization models for the nebula significantly better than before. Because the emission-line data set is sparse, the models are still not conclusive. Nevertheless, we confirm that this nebula is an extremely metal-poor planetary nebula, having a value for O/H that is less than 1/100 solar, and possibly as low as 1/500 solar.Comment: 19 pages, 6 figures. Accepted for publication in the Astronomical Journa

    A Large Outbreak of Hepatitis E Among a Displaced Population in Darfur, Sudan, 2004: The Role of Water Treatment Methods.

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    BACKGROUND: The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur. METHODS: To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples). RESULTS: In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested. CONCLUSIONS: Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies

    Optically bright Active Galactic Nuclei in the ROSAT-Faint Source Catalogue

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    To build a large, optically bright, X-ray selected AGN sample we have correlated the ROSAT-FSC catalogue of X-ray sources with the USNO catalogue limited to objects brighter than O=16.5 and then with the APS database. Each of the 3,212 coincidences was classified using the slitless Hamburg spectra. 493 objects were found to be extended and 2,719 starlike. Using both the extended objects and the galaxies known from published catalogues we built up a sample of 185 galaxies with O_APS < 17.0 mag, which are high-probability counterparts of RASS-FSC X-ray sources. 130 galaxies have a redshift from the literature and for another 34 we obtained new spectra. The fraction of Seyfert galaxies in this sample is 20 %. To select a corresponding sample of 144 high-probability counterparts among the starlike sources we searched for very blue objects in an APS-based color-magnitude diagram. Forty-one were already known AGN and for another 91 objects we obtained new spectra, yielding 42 new AGN, increasing their number in the sample to 83. This confirms that surveys of bright QSOs are still significantly incomplete. On the other hand we find that, at a flux limit of 0.02 count /-1 and at this magnitude, only 40 % of all QSOs are detected by ROSAT.Comment: 17 pages, 16 figures, accepted by A&

    Photometry and Spectroscopy of KS Ursae Majoris during Superoutburst

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    We report photometric and spectroscopic observations of the SU UMa-type dwarf novae, KS Ursae Majoris, during its 2003 February superoutburst. Modulations with a period of 0.07017±0.000210.07017\pm0.00021 day, which is 3.3% larger than the orbital period, have been found during the superoutburst and may be positive superhumps. A maximum trough-to-peak amplitude of around 0.3 magnitude is determined for this superhump. The spectra show broad, absorption-line profiles. The lines display blue and red troughs which alternate in depth. The radial velocity curve of the absorption wings of Hβ\beta has an amplitude of 40±1140\pm11 km s1^{-1} and a phase offset of 0.12±0.030.12\pm0.03. The γ\gamma velocity of the binary is 3±93\pm9 km s1^{-1} and varies on an order of 50 km s1^{-1} from day to day. From another clear evidence for a precessing eccentric disk, we obtain a solution to an eccentric outer disk consistent with theoretical works, which demonstrates the validity of the relation between superhumps and tidal effects. The inner part of the disk is also eccentric as evidenced by asymmetric and symmetric wings in the lines. Therefore, the whole disk is eccentric and the variation of γ\gamma velocity and the evolutionary asymmetric line profiles could be criterions for an precessing eccentric accretion disk.Comment: 12 pages, 8 figures, accpeted for publication in A

    Catalog of Radio Galaxies with z>0.3. I:Construction of the Sample

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    The procedure of the construction of a sample of distant (z>0.3z>0.3) radio galaxies using NED, SDSS, and CATS databases for further application in statistical tests is described. The sample is assumed to be cleaned from objects with quasar properties. Primary statistical analysis of the list is performed and the regression dependence of the spectral index on redshift is found.Comment: 9 pages, 6 figures, 2 table

    Результаты комбинированного антиангиогенного воздействия на новообразованные сосуды роговицы. экспериментально-морфологическое исследование

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    Results of comparative experimental and morphological study of activity on corneal neovascularization in rabbit’s eye of photodynamic therapy with Photosense and antiangiogenic therapy with Avastin (bevacizumab) alone, and in its combination are represented. The treatment was performed in regimens: 1) photodynamic therapy with Photosense (single intravenous injection in dose of 0.3 mg/kg 72 h prior to laser irradiation, power density of irradiation 500 mW/cm2, wavelength 675 nm); 2) drug antiangiogenic therapy with Avastin (single subconjuctival introduction at dose of 1.25 mg); 3) photodynamic therapy with Photosense (in described regimen) in combination with subconjuctival introduction of Avastin at dose of 1.25 mg immediately prior to irradiation. Combined photodynamic therapy with antiangiogenic therapy allows to obtain almost complete occlusion in all regions of corneal neovascular bed with shorter time interval comparing with those for monoregimens. In case of blood flow retention in great vessels courses of combined modality treatment may be repeated. The absence of side-effects on surrounding tissues and the recovery of optical characteristics of cornea may allow to use this upcoming method in clinical practice. Приведены результаты сравнительного экспериментально-морфологического исследования влияния на новообразованные сосуды роговицы глаза кролика фотодинамической терапии с препаратом фотосенс и медикаментозной антиангиогенной терапии с препаратом авастин (бевацизумаб) в режиме монотерапии, а также их сочетанного применения. Лечение проводили в режимах: 1) фотодинамическая терапия с препаратом фотосенс (однократное внутривенное введение в дозе 0,3 мг/кг за 72 ч до лазерного облучения, плотность мощности лазерного облучения 500 мВт/см2, длина волны 675 нм); 2) медикаментозная анти- ангиогенная терапия с препаратом авастин (однократное субконьюнктивальное введение в дозе 1,25 мг); 3) фотодинамическая терапия с препаратом фотосенс (в указанном режиме) в сочетании с субконьюнктивальным введением препарата авастин в дозе 1,25 мг непосредственно перед проведением облучения. Показано, что при сочетанном применении фотодинамической и антиогенной терапии можно добиться практически полной окклюзии во всех отделах новообразованного сосудистого русла роговицы, причем в более короткий промежуток времени по сравнению со временем лечения в монорежимах. В случае сохранения кровотока в крупных магистральных сосудах возможно проведение повторных курсов комбинированного лечения. Отсутствие побочного воздействия на окружающие ткани и восстановление оптических свойств роговицы возможно позволит в перспективе использовать предложенный метод в клинической практике.
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