Henoch-Schönlein purpura, patients admitted to Landspítali-University Hospital 1984-2000

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: Henoch-Schönlein purpura is a disease of small vessels which primarily affects children. The epidemiology of Henoch-Schönlein purpura in Iceland is not known. The main purpose of the study was to find out the incidence of the disease in Iceland and gather further epidemiological information. Patients and methods: All patients diagnosed with Henoch-Schönlein purpura during the years 1984-2000 and were admitted to the Children's Hospital Iceland, Landspítali Hringbraut as well as the paediatric department at the Landspítali Fossvogi were included in the study cohort. Information was gathered from medical records. The temporal relationship between the incidende of Henoch-Schönlein purpura and epidemics of three common infectious diseases was explored. Results: A total of 101 patients were found to have Henoch-Schönlein purpura, 51 females and 50 males. The incidence of Henoch-Schönlein purpura in Iceland is therefore approximately six cases annually. The mean age at diagnosis was 5.4 years. In addition to the rash, 72.3% had arthralgia and 45.5% abdominalia, 36.6% had hematuria or proteinuria during the hospitalization and 5.9% had severe renal involvement. The disease was more common in the winter months (Nov. - April) compared to the summer months (May - Oct.) (p=0.045). Conclusions: The epidemiology of Henoch-Schönlein purpura in Iceland is comparable to other countries. The disease was most common in children aged 2-5 years, which could reflect a common infection in the community as a part of the pathogenesis. Older children may have antibodies against these infections resulting in a decreased incidence of the disease. Our results support the theory that infection may play an important role in the pathogenesis of Henoch-Schönlein purpura. However, some abnormalities or variations in the immune response are probably also involved.Tilgangur: Henoch-Schönlein purpura er sjúkdómur sem einkennist af æðabólgu og kemur fyrst og fremst fram hjá börnum. Faraldsfræði Henoch-Schönlein purpura á Íslandi er ekki þekkt. Tilgangur rannsóknarinnar var því að kanna nýgengi sjúkdómsins á Íslandi auk þess að afla annarra faraldsfræðilegra upplýsinga. Sjúklingar og aðferðir: Allir sjúklingar 16 ára og yngri sem fengið höfðu greininguna Henoch-Schönlein purpura á tímabilinu 1984-2000 og voru lagðir inn á Barnaspítala Hringsins eða barnadeild Landspítala Fossvogi (áður SHR og Landakotsspítali) mynduðu rannsóknarhópinn. Safnað var upplýsingum úr sjúkraskrám um einkenni og rannsóknarniðurstöður. Sveiflur í tíðni sjúkdómsins voru bornar saman við sveiflur nokkurra þekktra smitsjúkdóma. Niðurstöður: Alls greindist 101 sjúklingur með Henoch-Schönlein purpura á tímabilinu, 51 stúlka og 50 drengir. Nýgengi Henoch-Schönlein purpura virðist svipað á Íslandi og víðast annars staðar, eða um sex tilfelli á ári. Meðalaldur var 5,4 ár. Auk útbrotanna reyndust 72,3% hafa liðverki og 45,5% kviðverki, 36,6% höfðu blóðmigu eða prótínmigu á meðan á sjúkrahúsvist stóð og 5,9% fengu alvarlegan nýrnasjúkdóm. Sjúkdómurinn var algengari á vetrarmánuðum (nóvember-apríl) en á sumarmánuðum (maí-október) (p= 0,045). Ályktanir: Faraldsfræði Henoch-Schönlein purpura hjá börnum á Íslandi virðist vera svipuð og í öðrum löndum. Áhugavert er að sjúkdómurinn er algengastur meðal barna tveggja til fimm ára og gæti það endurspeglað að algeng sýking eða sýkingar séu einn af orsakavöldum hans. Þegar börnin eldast og öðlast mótefni gegn slíkum sýkingum dregur úr tíðni sjúkdómsins. Mögulegt er að sýkingar séu einn þáttur í ferli sem ræsir sjúkdóminn en að auki þurfi ákveðin samsetning ónæmiskerfis að vera til staðar

Measuring the Obliquities of the TRAPPIST-1 Planets with MAROON-X

A star's obliquity with respect to its planetary system can provide us with insight into the system's formation and evolution, as well as hinting at the presence of additional objects in the system. However, M dwarfs, which are the most promising targets for atmospheric follow-up, are underrepresented in terms of obliquity characterization surveys due to the challenges associated with making precise measurements. In this paper, we use the extreme-precision radial velocity spectrograph MAROON-X to measure the obliquity of the late M dwarf TRAPPIST-1. With the Rossiter-McLaughlin effect, we measure a system obliquity of $-2^{+17}_{-19}$ degrees and a stellar rotational velocity of 2.1 $\pm$ 0.3 km s$^{-1}$. We were unable to detect stellar surface differential rotation, and we found that a model in which all planets share the same obliquity was favored by our current data. We were unable to make a detection of the signatures of the planets using Doppler tomography, which is likely a result of the both the slow rotation of the star and the low SNR of the data. Overall, TRAPPIST-1 appears to have a low obliquity, which could imply that the system has a low primordial obliquity. It also appears to be a slow rotator, which is consistent with past characterizations of the system and estimates of the star's rotation period. The MAROON-X data allow for a precise measurement of the stellar obliquity through the Rossiter-McLaughlin effect, highlighting the capabilities of MAROON-X and its ability to make high-precision RV measurements around late, dim stars.Comment: 18 pages, 6 figures, submitted to A

Bacteremia in children with tumors or malignant diseases 1991-2000

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenIntroduction: Ten to twelve children with tumors or malignant diseases are diagnosed annually in Iceland. Cancer treatment can cause severe immune suppression, which makes the patients susceptible to serious infections. The aim of the current study was to evaluate sepsis in children with tumors or haematological malignancies, describe the types of bacteria cultured and their antibiotic susceptibilities, and collect information on associated risk factors. Materials and methods: This was a retrospective study on all children 0-15 years of age in Iceland who were diagnosed with a tumor or malignant disease between 1991 and 2000. Information was gathered on diagnosis, treatment, blood cultures, blood tests, antibiotic use, presence of foreign bodies (such as CVC) and survival. Results: Hundred-and-eighteen children were diagnosed with cancer or benign central nervous system (CNS) tumors in Iceland during the period 1991-2000. Central nervous system tumors were most common (N=28, 23.7%), leukemia (N=21, 17.8%) and lymphoma (N=17, 14%) were the second and third. The mean age at diagnosis was 5.9 years. Sufficient data was found in the hospital records on 99 children who were included in the study. Five hundred and twenty two blood cultures were drawn from 51 of the 99 children during the period. The mean number of blood cultures per patient was 14.8 for children with leukemia, but 2.6 for children with solid tumors. Of all blood cultures, 63.6% were from a central venous catheter or a Port-A Catheter , 5% from a peripheral site, but 30% were undisclosed. Of the 522 blood cultures, 90 grew bacteria (17.2%). Coagulase-negative staphylococci were isolated from 53 blood cultures (60%) and Staphylococcus aureus from 12 (13%). Positive cultures were regarded as a definite or possible infection in 47 blood cultures (52%), contamination in 17 (18.9% ), but uncertain in 26 (27.7%). Over 60 percent of the blood cultures (N=302) were drawn when a child was neutropenic (ANCInngangur: Árlega greinast 10-12 börn með æxli og illkynja sjúkdóma á Íslandi. Meðferð við illkynja sjúkdómum eykur hættu á alvarlegum sýkingum sem mikilvægt er að bregðast rétt við. Markmið rannsóknarinnar var að meta blóðsýkingar í börnum með æxli og illkynja sjúkdóma, þar með talið einstakar bakteríur og sýklalyfjanæmi þeirra. Áhættuþættir voru einnig kannaðir. Efniviður og aðferðir: Rannsóknin var aftur-skyggn og var rannsóknarþýðið öll börn á aldrinum 0-15 ára greind með illkynja sjúkdóm eða æxli á árunum 1991-2000 á Barnaspítala Hringsins. Upplýsingum var safnað um greiningu, meðferð, blóðræktanir, blóðgildi og fleira, svo sem sýklalyfjanotkun, aðskotahluti og afdrif. Niðurstöður: Alls greindust 118 börn með illkynja sjúkdóm eða æxli á tímabilinu. Æxli í miðtaugakerfi (MTK) voru algengust (N=28, 23,7%), þá hvítblæði (N=21, 17,8%) og eitlakrabbamein (N=17, 14%). Meðalaldur barna við greiningu var 5,9 ár. Upplýsingar úr sjúkraskrám voru fullnægjandi fyrir 99 börn. Af þeim var 51 barn blóðræktað. Fjöldi blóðræktana var 522. Meðalfjöldi blóðræktana var 14,8 hjá börnum með hvítblæði, en 2,6 hjá börnum með föst æxli. Blóðræktanir voru teknar úr holæðalegg eða lyfjabrunni í 63,6%, 5,4% úr útbláæð en 31% tilfella voru ótilgreind. Af 522 ræktunum voru 90 jákvæðar (17,2%). Algengasta bakterían var kóagúlasa-neikvæður stafýlókokkur (KNS) (N=53, 60%), en Staphylococcus aureus næstalgengastur (N=12, 13,3%). Jákvæð ræktun var talin tengjast líklegri eða sannaðri sýkingu í 47 tilfellum (52%), mengun í 17 (18,9%) en óvíst var með 26 ræktanir (27,7%). Barn hafði daufkyrningafæð (ANC ?1,0 *109/L) við 302 blóðræktanir (61,4%). Meðallengd daufkyrningafæðar var 9,0 dagar. C-reative protein (CRP) var að meðaltali 63,9 mg/L við blóðræktun og meðalhiti var 38,8 °C. Í 183 tilfellum var barn á sýklalyfjum við blóðræktun (35,1%). Rannsóknarniðurstöður barna með jákvæða blóðræktun voru ekki frábrugðnar öðrum. Ályktanir: Sýkingar af völdum Gram-jákvæðra baktería, sérstaklega KNS, eru nú mun algengari en Gram-neikvæðra baktería. Hluti jákvæðra ræktana getur þó verið mengun. Blóðrannsóknir virðast hafa lítið forspárgildi um niðurstöður blóðræktana. Ekkert barn lést úr blóðsýkingu af völdum baktería á tímabilinu. Reynslusýklalyfjameðferð hérlendis virðist enn árangursrík

A comprehensive radial velocity error budget for next generation Doppler spectrometers

We describe a detailed radial velocity error budget for the NASA-NSF Extreme Precision Doppler Spectrometer instrument concept NEID (NN-explore Exoplanet Investigations with Doppler spectroscopy). Such an instrument performance budget is a necessity for both identifying the variety of noise sources currently limiting Doppler measurements, and estimating the achievable performance of next generation exoplanet hunting Doppler spectrometers. For these instruments, no single source of instrumental error is expected to set the overall measurement floor. Rather, the overall instrumental measurement precision is set by the contribution of many individual error sources. We use a combination of numerical simulations, educated estimates based on published materials, extrapolations of physical models, results from laboratory measurements of spectroscopic subsystems, and informed upper limits for a variety of error sources to identify likely sources of systematic error and construct our global instrument performance error budget. While natively focused on the performance of the NEID instrument, this modular performance budget is immediately adaptable to a number of current and future instruments. Such an approach is an important step in charting a path towards improving Doppler measurement precisions to the levels necessary for discovering Earth-like planets.Comment: 20 pages, 12 figures, published in Proc. of SPIE Astronomical Telescopes + Instrumentation 201

Characterization of low-mass companions to Kepler\textit{Kepler} objects of interest observed with APOGEE-N

We report the characterization of 28 low-mass ($0.02\mathrm{~M_\odot}\le\mathrm{~M_{2}}\le0.25\mathrm{~M_\odot}$) companions to $\textit{Kepler}$ objects of interest (KOIs), eight of which were previously designated confirmed planets. These objects were detected as transiting companions to Sun-like stars (G and F dwarfs) by the $\textit{Kepler}$ mission and are confirmed as single-lined spectroscopic binaries in the current work using the northern multiplexed Apache Point Observatory Galactic Evolution Experiment near-infrared spectrograph (APOGEE-N) as part of the third and fourth Sloan Digital Sky Surveys. We have observed hundreds of KOIs using APOGEE-N and collected a total of 43,175 spectra with a median of 19 visits and a median baseline of $\sim1.9$ years per target. We jointly model the $\textit{Kepler}$ photometry and APOGEE-N radial velocities to derive fundamental parameters for this subset of 28 transiting companions. The radii for most of these low-mass companions are over-inflated (by $\sim10\%$) when compared to theoretical models. Tidally locked M dwarfs on short period orbits show the largest amount of inflation, but inflation is also evident for companions that are well separated from the host star. We demonstrate that APOGEE-N data provides reliable radial velocities when compared to precise high-resolution spectrographs that enable detailed characterization of individual systems and the inference of orbital elements for faint ($H>12$) KOIs. The data from the entire APOGEE-KOI program is public and presents an opportunity to characterize an extensive subset of the binary population observed by $\textit{Kepler}$.Comment: 98 pages (include 56 for the figure sets), 10 tables, 7 figures, 2 figure sets, accepted for publication in ApJ

Association of Genetically Predicted Lipid Levels With the Extent of Coronary Atherosclerosis in Icelandic Adults.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadImportance: Genetic studies have evaluated the influence of blood lipid levels on the risk of coronary artery disease (CAD), but less is known about how they are associated with the extent of coronary atherosclerosis. Objective: To estimate the contributions of genetically predicted blood lipid levels on the extent of coronary atherosclerosis. Design, setting, and participants: This genetic study included Icelandic adults who had undergone coronary angiography or assessment of coronary artery calcium using cardiac computed tomography. The study incorporates data collected from January 1987 to December 2017 in Iceland in the Swedish Coronary Angiography and Angioplasty Registry and 2 registries of individuals who had undergone percutaneous coronary interventions and coronary artery bypass grafting. For each participant, genetic scores were calculated for levels of non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides, based on reported effect sizes of 345 independent, lipid-associated variants. The genetic scores' predictive ability for lipid levels was assessed in more than 87 000 Icelandic adults. A mendelian randomization approach was used to estimate the contribution of each lipid trait. Exposures: Genetic scores for levels of non-HDL-C, LDL-C, HDL-C, and triglycerides. Main outcomes and measures: The extent of angiographic CAD and coronary artery calcium quantity. Results: A total of 12 460 adults (mean [SD] age, 65.1 [10.7] years; 8383 men [67.3%]) underwent coronary angiography, and 4837 had coronary artery calcium assessed by computed tomography. A genetically predicted increase in non-HDL-C levels by 1 SD (38 mg/dL [to convert to millimoles per liter, multiply by 0.0259]) was associated with greater odds of obstructive CAD (odds ratio [OR], 1.83 [95% CI, 1.63-2.07]; P = 2.8 × 10-23). Among patients with obstructive CAD, there were significant associations with multivessel disease (OR, 1.26 [95% CI, 1.11-1.44]; P = 4.1 × 10-4) and 3-vessel disease (OR, 1.47 [95% CI, 1.26-1.72]; P = 9.2 × 10-7). There were also significant associations with the presence of coronary artery calcium (OR, 2.04 [95% CI, 1.70-2.44]; P = 5.3 × 10-15) and loge-transformed coronary artery calcium (effect, 0.70 [95% CI, 0.53-0.87]; P = 1.0 × 10-15). Genetically predicted levels of non-HDL-C remained associated with obstructive CAD and coronary artery calcium extent even after accounting for the association with LDL-C. Genetically predicted levels of HDL-C and triglycerides were associated individually with the extent of coronary atherosclerosis, but not after accounting for the association with non-HDL cholesterol. Conclusions and relevance: In this study, genetically predicted levels of non-HDL-C were associated with the extent of coronary atherosclerosis as estimated by 2 different methods. The association was stronger than for genetically predicted levels of LDL-C. These findings further support the notion that non-HDL-C may be a better marker of the overall burden of atherogenic lipoproteins than LDL-C.deCODE genetics/Amgen Inc

A Large and Variable Leading Tail of Helium in a Hot Saturn Undergoing Runaway Inflation

Atmospheric escape shapes the fate of exoplanets, with statistical evidence for transformative mass loss imprinted across the mass-radius-insolation distribution. Here we present transit spectroscopy of the highly irradiated, low-gravity, inflated hot Saturn HAT-P-67 b. The Habitable Zone Planet Finder (HPF) spectra show a detection of up to 10% absorption depth of the 10833 Angstrom Helium triplet. The 13.8 hours of on-sky integration time over 39 nights sample the entire planet orbit, uncovering excess Helium absorption preceding the transit by up to 130 planetary radii in a large leading tail. This configuration can be understood as the escaping material overflowing its small Roche lobe and advecting most of the gas into the stellar -- and not planetary -- rest frame, consistent with the Doppler velocity structure seen in the Helium line profiles. The prominent leading tail serves as direct evidence for dayside mass loss with a strong day-/night- side asymmetry. We see some transit-to-transit variability in the line profile, consistent with the interplay of stellar and planetary winds. We employ 1D Parker wind models to estimate the mass loss rate, finding values on the order of $2\times10^{13}$ g/s, with large uncertainties owing to the unknown XUV flux of the F host star. The large mass loss in HAT-P-67 b represents a valuable example of an inflated hot Saturn, a class of planets recently identified to be rare as their atmospheres are predicted to evaporate quickly. We contrast two physical mechanisms for runaway evaporation: Ohmic dissipation and XUV irradiation, slightly favoring the latter.Comment: Submitted to The Astronomical Journa