24 research outputs found
The fast transient sky with Gaia
The ESA Gaia satellite scans the whole sky with a temporal sampling ranging
from seconds and hours to months. Each time a source passes within the Gaia
field of view, it moves over 10 CCDs in 45 s and a lightcurve with 4.5 s
sampling (the crossing time per CCD) is registered. Given that the 4.5 s
sampling represents a virtually unexplored parameter space in optical time
domain astronomy, this data set potentially provides a unique opportunity to
open up the fast transient sky. We present a method to start mining the wealth
of information in the per CCD Gaia data. We perform extensive data filtering to
eliminate known on-board and data processing artefacts, and present a
statistical method to identify sources that show transient brightness
variations on ~2 hours timescales. We illustrate that by using the Gaia
photometric CCD measurements, we can detect transient brightness variations
down to an amplitude of 0.3 mag on timescales ranging from 15 seconds to
several hours. We search an area of ~23.5 square degrees on the sky, and find
four strong candidate fast transients. Two candidates are tentatively
classified as flares on M-dwarf stars, while one is probably a flare on a giant
star and one potentially a flare on a solar type star. These classifications
are based on archival data and the timescales involved. We argue that the
method presented here can be added to the existing Gaia Science Alerts
infrastructure for the near real-time public dissemination of fast transient
events.Comment: 10 pages, 5 figures and 5 tables; MNRAS in pres
A novel adenovirus of Western lowland gorillas (Gorilla gorilla gorilla)
Adenoviruses (AdV) broadly infect vertebrate hosts including a variety of primates. We identified a novel AdV in the feces of captive gorillas by isolation in cell culture, electron microscopy and PCR. From the supernatants of infected cultures we amplified DNA polymerase (DPOL), preterminal protein (pTP) and hexon gene sequences with generic pan primate AdV PCR assays. The sequences in-between were amplified by long-distance PCRs of 2 - 10 kb length, resulting in a final sequence of 15.6 kb. Phylogenetic analysis placed the novel gorilla AdV into a cluster of primate AdVs belonging to the species Human adenovirus B (HAdV-B). Depending on the analyzed gene, its position within the cluster was variable. To further elucidate its origin, feces samples of wild gorillas were analyzed. AdV hexon sequences were detected which are indicative for three distinct and novel gorilla HAdV-B viruses, among them a virus nearly identical to the novel AdV isolated from captive gorillas. This shows that the discovered virus is a member of a group of HAdV-B viruses that naturally infect gorillas. The mixed phylogenetic clusters of gorilla, chimpanzee, bonobo and human AdVs within the HAdV-B species indicate that host switches may have been a component of the evolution of human and non-human primate HAdV-B viruses
Glucose transporter-1 deficiency syndrome: the expanding clinical and genetic spectrum of a treatable disorder
Glucose transporter-1 deficiency syndrome is caused by mutations in the SLC2A1 gene in the majority of patients and results in impaired glucose transport into the brain. From 2004-2008, 132 requests for mutational analysis of the SLC2A1 gene were studied by automated Sanger sequencing and multiplex ligation-dependent probe amplification. Mutations in the SLC2A1 gene were detected in 54 patients (41%) and subsequently in three clinically affected family members. In these 57 patients we identified 49 different mutations, including six multiple exon deletions, six known mutations and 37 novel mutations (13 missense, five nonsense, 13 frame shift, four splice site and two translation initiation mutations). Clinical data were retrospectively collected from referring physicians by means of a questionnaire. Three different phenotypes were recognized: (i) the classical phenotype (84%), subdivided into early-onset (<2 years) (65%) and late-onset (18%); (ii) a non-classical phenotype, with mental retardation and movement disorder, without epilepsy (15%); and (iii) one adult case of glucose transporter-1 deficiency syndrome with minimal symptoms. Recognizing glucose transporter-1 deficiency syndrome is important, since a ketogenic diet was effective in most of the patients with epilepsy (86%) and also reduced movement disorders in 48% of the patients with a classical phenotype and 71% of the patients with a non-classical phenotype. The average delay in diagnosing classical glucose transporter-1 deficiency syndrome was 6.6 years (range 1 month-16 years). Cerebrospinal fluid glucose was below 2.5 mmol/l (range 0.9-2.4 mmol/l) in all patients and cerebrospinal fluid : blood glucose ratio was below 0.50 in all but one patient (range 0.19-0.52). Cerebrospinal fluid lactate was low to normal in all patients. Our relatively large series of 57 patients with glucose transporter-1 deficiency syndrome allowed us to identify correlations between genotype, phenotype and biochemical data. Type of mutation was related to the severity of mental retardation and the presence of complex movement disorders. Cerebrospinal fluid : blood glucose ratio was related to type of mutation and phenotype. In conclusion, a substantial number of the patients with glucose transporter-1 deficiency syndrome do not have epilepsy. Our study demonstrates that a lumbar puncture provides the diagnostic clue to glucose transporter-1 deficiency syndrome and can thereby dramatically reduce diagnostic delay to allow early start of the ketogenic die
a high level of genetic diversity and evidence of recombination and zoonotic transmission
Adenoviren sind in der Lage, ein breites Wirbeltierspektrum zu infizieren,
unter ihnen eine Vielzahl nicht-humaner Primaten. Die vorliegende Arbeit
beschäftigte sich mit folgenden Fragestellungen: (i) Kommen AdVs bei
wildlebenden nicht-humanen Primaten vor? (ii) Wie sind ihre phylogenetischen
Eigenschaften? (iii) Besteht Potenzial einer zoonotischen Übertragung zwischen
Menschen und nicht menschlichen Primaten? (iv) Lassen sich Rekombinationen bei
AdVs wildlebender Primaten beobachten? Hierzu wurden 1285 Proben simianer
Herkunft untersucht. Kot erwies sich als sehr geeignetes Probenmaterial zum
AdV-Nachweis. Es konnten insgesamt 46 neuartige AdVs mittels degenerierter PCR
Assays detektiert werden. Von ihnen stehen DPOL-Teilsequenzen zur Verfügung.
Bei 29 gelang zusätzlich aus der gleichen Probe die Amplifikation des nahezu
gesamten Hexon-Gens. Ob DPOL- und Hexon-Sequenzen aus einer Probe vom gleichen
Virusgenom stammten, war nicht zu ermitteln. Deshalb wurden DPOL- und Hexon-
Teilsequenzen getrennt betrachtet. Zusätzlich gelang es, ein AdV aus im
Münsteraner Allwetterzoo gehaltenen Gorillas anzuzüchten und zu sequenzieren.
Bei diesem AdV konnten DPOL- und Hexonsequenzen miteinander verbunden werden,
wodurch eine Teilsequenz von 15.6 kb Länge für Vergleiche mit Genomen anderer
AdVs und phylogenetische Untersuchungen zur Verfügung stand. Die Berechnungen
phylogenetischer Stammbäume ergaben für Nukleinsäureteilsequenzen des DPOL-
und Hexon-Gens eine hohe genetische Diversität. Die neuartigen AdVs
gruppierten sich innerhalb aller etablierten humanen und simianen AdV-Spezies
ein. Sieben AdVs von Altweltaffen bildeten eigene Kluster und konnten keiner
bekannten AdV-Spezies zugeordnet werden. Zusätzlich konnten erstmalig
Sequenzen von zwei distinkten AdVs aus Neuweltaffen nachgewiesen und
phylogenetisch analysiert werden. Fünf in wildlebenden Schimpansen gefundene
AdVs gaben Hinweise auf zoonotische Übertragungen zwischen Mensch und
Schimpanse [PtroAdV-8 [HAdV-A], PtroAdV-10 [HAdV-D], PtroAdV-3 [HAdV-F],
PtroAdV-7 [HAdV-B] und PtroAdV-14 [HAdV-E]]. Dies zeigt erstmalig, dass AdVs
aus wildlebenden Menschenaffen große phylogenetische Ähnlichkeiten zu humanen
AdVs aufweisen können. Allerdings wurden nur für einige AdVs Hinweise auf die
Richtung der Übertragung erhalten. Um das zoonotische Potential von AdVs nicht
humaner Primaten besser abzuklären zu können, sollten in Zukunft auch humane
AdVs der gleichen Regionen identifiziert werden und Eingang in die
phylogenetische Untersuchungen finden. Trotz Bemühungen, DPOL- und Hexon-
Genteilsequenzen der AdVs wilder NHP miteinander zu verbinden, gelang dies nur
bei dem angezüchteten AdV GgorAdV-B7. Deshalb wurde auch nur die Genom-
Teilsequenz dieses AdV (15.6kb Länge) auf Rekombinationsereignisse untersucht.
Die BLAST-Analyse der gesamten Nukleinsäureteilsequenz ergab, dass GgorAdV-B7
die größte Ähnlichkeit zu dem Schimpansen AdV SAdV-35.1 und dem humanen AdV
HAdV-21 hat. Zusätzlich wurden phylogenetische Stammbäume der Gene DPOL, pTP,
Penton und Hexon berechnet. Sie zeigten, dass GgorAdV-B7 in jedem Gen mit
unterschiedlichen AdVs Gruppen bildete. So ist GgorAdV-B7 im DPOL- und pTP-Gen
eng mit einer Vielzahl von AdVs von Gorillas und Schimpansen gruppiert. Im
Hexon-Gen gruppiert es sich mit dem Schimpansen AdV SAdV-35.1, dem Bonobo AdV
SAdV-35.2 und drei humanen AdVs (HAdV-11, HAdV-21 und HAdV-35). Die
Nukleinsäuresequenz des Penton-Gens von GgorAdV-B7 hingegen ist nahezu
identisch mit der Nukleinsäuresequenz des Penton-Gens des Schimpansen AdV
SAdV-29. Diese unterschiedliche Gruppenbildung ist nicht durch eine
koevolutionäre Entwicklung von GgorAdV-B7 mit seinem Wirt erklärbar, sondern
Inter-Spezies-Übertragungen und Rekombinationsereignisse müssen ebenso eine
Rolle gespielt haben. Insbesondere im Penton-Gen gibt es Hinweise auf ein
Rekombinationsereignis zwischen AdVs unterschiedlicher Wirte. Elternviren
konnten jedoch nicht identifiziert werden. Die Erkenntnisse dieser Arbeit
lassen davon ausgehen, dass AdVs über ein nicht zu vernachlässigendes
zoonotisches Potential verfügen und ihre phylogenetische Diversität durch
Rekombinationsereignisse erhöht wird. Ob AdVs nicht humanen Ursprungs bereits
in lokalen afrikanischen Bevölkerungsgruppen oder AdVs humanen Ursprungs in
Affenpopulationen zirkulieren, ist bisher kaum abschätzbar. Im Hinblick auf
die Gefährdung der Bevölkerung durch Pathogene zoonotischen Ursprungs und
einhergehende Belastung der öffentlichen Gesundheitssysteme können
Erkenntnisse und Nachweissysteme, wie die hier vorgelegten helfen, frühzeitig
Risiken zu erkennen und Gegenmaßnahmen einzuleiten.Adenoviruses (AdVs) broadly infect vertebrate hosts including a variety of
primates. The present study assessed the following questions: (i) Are AdVs
present in wild nonhuman primates (NHPs)? (ii) How are their phylogenetic
properties? (iii) Is there evidence for interspecies transmission between
humans and NHPs? (iv) Do recombination events occur among AdVs of NHPs? A
total of 1285 samples of simian origin were analyzed for the presence of AdVs
with a panprimate AdV-specific PCR targeting a highly conserved region of the
DNA polymerase (DPOL) gene. With this approach a plethora of novel AdV
sequences were identified, representing at least 46 distinct AdVs. Of these,
29 nearly complete hexon genes could be amplified. DPOL and hexon sequence
from a given sample could not be connected by longdistance PCR. Therefore,
only the hexon sequences were the basis for tentative virus names. In addition
we identified a novel AdV in the faeces of captive gorillas living in the
Zoological gardens of Münster by isolation in cell culture and PCR. Hexon and
DPOL gene sequences of this particular virus could be connected by
amplification of the in-between sequence resulting in a final sequence of 15.6
kb. Phylogenetic analysis performed in Maximum Likelihood frameworks revealed
a high level of genetic diversity of the novel AdVs. They exhibited a broad
evolutionary spectrum and were tentatively allocated to all established human
and simian AdV species. Seven AdVs of Old World monkeys (OWMs) grouped
separately and could not be assigned to any known AdV species. Furthermore,
three DPOL sequences were identified in New World monkeys (NWMs) that
clustered in a well-separated clade at the base of the primate AdV tree,
possibly reflecting the split between NWMs and OWMs. Five AdVs detected in
wild chimpanzees revealed a remarkably close relationship to human AdVs over
their entire hexon gene sequence, and thus provide evidence for interspecies
transmission events between humans and chimpanzees. The directionality of
these transmissions could not be firmly determined. Namely these viruses are:
PtroAdV-8 [HAdV-A], PtroAdV-10 [HAdV-D], PtroAdV-3 [HAdV-F], PtroAdV-7
[HAdV-B], and PtroAdV- 14 [HAdV-E]. The 15.6 kb sequence of GgorAdV-B7 was
subjected to recombination analyses. In BLAST analysis of GenBank, the whole
sequence was most closely related to the chimpanzee AdV SAdV-35.1 and the
human AdV HAdV-21. Phylogenetic trees were constructed for DPOL, pTP, penton
base and hexon gene alignments, revealing a mixed clustering of GgorAdV-B7
with different AdVs in each phylogenetic tree. In the DPOL and the pTP gene,
GgorAdV-B7 formed a tight clade with AdVs from chimpanzees and gorillas. In
the hexon gene GgorAdV-B7 was most closely associated with one chimpanzee AdV
SAdV- 35.1, one bonobo AdV SAdV-35.2 and three human AdVs (HAdV-11, -21, and
-35). However, the penton base gene of GgorAdV-B7 showed a striking similarity
to that of the chimpanzee AdV SAdV-29. Taken together, these observations
cannot be explained by cospeciation of GgorAdV-B7 with its gorilla host.
Rather, they are in line with recombination and host switching, and the
striking similarity to SAdV-29 suggests that recombination events between AdVs
of different host species might take place. In light of current knowledge,
parent viruses could not be assigned, indicating a more ancient recombination
event with subsequent genetic drift or recombination with an unknown AdV. The
high variety of known and novel AdVs of NHPs calls for larger studies to
understand the diversity of AdVs currently circulating in African NHPs as well
as in local African human populations. This may answer the intriguing question
of whether NHPs and humans have an intersected “adeno-virosphere” and may
provide the basis for elucidating the potential pathological consequences of
interspecies AdV transmission. Studies of this kind may help to establish a
global early warning system for emerging diseases, given the need to protect
both public health and endangered NHPs
A novel adenovirus of Western lowland gorillas (<it>Gorilla gorilla gorilla</it>)
Abstract Adenoviruses (AdV) broadly infect vertebrate hosts including a variety of primates. We identified a novel AdV in the feces of captive gorillas by isolation in cell culture, electron microscopy and PCR. From the supernatants of infected cultures we amplified DNA polymerase (DPOL), preterminal protein (pTP) and hexon gene sequences with generic pan primate AdV PCR assays. The sequences in-between were amplified by long-distance PCRs of 2 - 10 kb length, resulting in a final sequence of 15.6 kb. Phylogenetic analysis placed the novel gorilla AdV into a cluster of primate AdVs belonging to the species Human adenovirus B (HAdV-B). Depending on the analyzed gene, its position within the cluster was variable. To further elucidate its origin, feces samples of wild gorillas were analyzed. AdV hexon sequences were detected which are indicative for three distinct and novel gorilla HAdV-B viruses, among them a virus nearly identical to the novel AdV isolated from captive gorillas. This shows that the discovered virus is a member of a group of HAdV-B viruses that naturally infect gorillas. The mixed phylogenetic clusters of gorilla, chimpanzee, bonobo and human AdVs within the HAdV-B species indicate that host switches may have been a component of the evolution of human and non-human primate HAdV-B viruses.</p
Seeking Indigneity: The search for “The lost tribe” in Janet Frame's The edge of the alphabet
Seroreactivity of German sera and Ivorian plasma samples against polyomaviruses by age group.
a<p>number of sera from Germany before, number of plasma samples from Côte d'Ivoire after the slash;</p><p>-, not available.</p
Reactivity of chimpanzee plasma samples to VP1 proteins of chimpanzee polyomaviruses.
<p>Antibody reactivity was assessed against the 4 chimpanzee polyomaviruses ChPyV, PtrovPyV3, PtrovPyV4 and PtrosPyV2 using plasma of 40 chimpanzees. Samples were analysed for seroreactivity with a capsomer-based IgG ELISA using the VP1 major capsid protein of the above polyomaviruses as antigens. The spread of absorbance measurement is shown with black dots, and cut-off values (COVs) are depicted with solid lines (PtrovPyV3: 0.028; PtrovPyV4: 0.023; PtrosPyV2: 0.013). A COV for ChPyV could not be calculated because all OD<sub>450</sub> values were >0.3.</p