312 research outputs found
2,3-butanediol in experimental myocardial ischaemia in pigs
To investigate the role of 2,3-butanediol in myocardial ischaemia we analysed this compound in pig's myocardium and blood. Ischaemia was induced by ligation of a coronary artery. In the first study we found significantly higher levels of 2,3-butanediol in the homogenate of ischaemic myocardium than in non-ischaemic myocardium. The lactate concentration was also significantly elevated. In the second study, where ischaemia was similarly induced, and where reperfusion was achieved by re-opening the ligated coronary artery after 20 min, 2,3-butanediol in peripheral blood was found to increase significantly. In the pigs in which the coronary artery was not re-opened, the 2,3-butanediol level in peripheral blood was unchanged. We conclude that in pigs' anaerobic myocardia accumulation of 2,3-butanediol occurs; if the myocardium is reperfused this metabolite also appears in the bloo
Anatomical organization of the cerebrum of the praying mantis <em>Hierodula membranacea</em>
\ua9 2024 The Authors. The Journal of Comparative Neurology published by Wiley Periodicals LLC.Many predatory animals, such as the praying mantis, use vision for prey detection and capture. Mantises are known in particular for their capability to estimate distances to prey by stereoscopic vision. While the initial visual processing centers have been extensively documented, we lack knowledge on the architecture of central brain regions, pivotal for sensory motor transformation and higher brain functions. To close this gap, we provide a three-dimensional (3D) reconstruction of the central brain of the Asian mantis, Hierodula membranacea. The atlas facilitates in-depth analysis of neuron ramification regions and aides in elucidating potential neuronal pathways. We integrated seven 3D-reconstructed visual interneurons into the atlas. In total, 42 distinct neuropils of the cerebrum were reconstructed based on synapsin-immunolabeled whole-mount brains. Backfills from the antenna and maxillary palps, as well as immunolabeling of γ-aminobutyric acid (GABA) and tyrosine hydroxylase (TH), further substantiate the identification and boundaries of brain areas. The composition and internal organization of the neuropils were compared to the anatomical organization of the brain of the fruit fly (Drosophila melanogaster) and the two available brain atlases of Polyneoptera—the desert locust (Schistocerca gregaria) and the Madeira cockroach (Rhyparobia maderae). This study paves the way for detailed analyses of neuronal circuitry and promotes cross-species brain comparisons. We discuss differences in brain organization between holometabolous and polyneopteran insects. Identification of ramification sites of the visual neurons integrated into the atlas supports previous claims about homologous structures in the optic lobes of flies and mantises
Different techniques of distal aortic repair in acute type A dissection: impact on late aortic morphology and reoperation
Objective: To compare three different techniques of distal aortic repair in acute type A (de Bakey type I) aortic dissection and to evaluate their impact on the late morphology of the aortic arch and descending aorta and on the incidence of reoperation. Methods: From 65 patients operated on due to an acute type A aortic dissection between 1989 and 1993, 54 long-term survivors underwent clinical and radiologic follow-up examination after a mean postoperative interval of 62±16 months. The surgical techniques of distal aortic reconstruction included closed repair using Teflon felt reinforcement under moderate hypothermic cardiopulmonary bypass (n=20) and open repair in deep hypothermic circulatory arrest using either Teflon felt reinforcement (n=16) or gelatin-resorcin-formaldehyde (GRF) glue (n=18) to readapt the dissected aortic layers. In all patients, MR imaging was performed on a 1.5-T whole body imaging system for the evaluation of the morphology and function of the heart, aorta and supraaortic branches. Results: Overall hospital mortality following surgical repair of type A aortic dissection was 15.4% during this time period. The highest rate of persistent false lumen perfusion (17/20, 85%) and presence of an intimal flap in the aortic arch (13/20, 65%) was observed in patients following closed repair of acute ascending aortic dissection, whereas the lowest rate of such findings was demonstrated in patients who had undergone open distal aortic repair using biological glue (false lumen perfusion 10/18, 55% and intimal flap in the arch 2/18, 11%). Redo-surgery was significantly reduced in the open repair group using GRF glue (1/18, 5.5%) as compared with the Teflon felt repair group (3/16, 18%) and the closed repair group (6/20, 30%). Conclusions: In patients with acute type A dissection, open distal aortic repair using GRF-glue favourably influences both (1) the severity of late morphologic alterations in the downstream aorta and (2) the incidence of reoperatio
Constraints on the origin of the massive, hot, and rapidly rotating magnetic white dwarf RE J 0317-853 from an HST parallax measurement
We use the parallax measurements of RE J 0317-853 to determine its mass,
radius, and cooling age and thereby constrain its evolutionary origins. We
observed RE J 0317-853 with the the Hubble Space Telescope's Fine Guidance
System to measure the parallax of RE J 0317-853 and its binary companion, the
non-magnetic white dwarf LB 9802. In addition, we acquired spectra of
comparison stars with the Boller & Chivens spectrograph of the SMARTS telescope
to correct the parallax zero point. For the corrected parallax, we determine
the radius, mass, and the cooling age with the help of evolutionary models from
the literature. The properties of RE J 0317-853 are constrained using the
parallax information. We discuss the different cases of the core composition
and the uncertain effective temperature. We confirm that RE J 0317-853 is close
to the Chandrasekhar's mass limit in all cases and almost as old as its
companion LB 9802. The precise evolutionary history of RE J 0317-853 depends on
our knowledge of its effective temperature. It is possible that it had a single
star progenitor possible if we assume that the effective temperature is at the
cooler end of the possible range from 30000 to 50000; if T_eff is instead at
the hotter end, a binary-merger scenario for RE J 0317-853 becomes more
plausible.Comment: 11 pages, 6 figures; language revised edition with added references.
Accepted for publication in Astronomy and Astrophysic
Photodynamic therapy with mTHPC and polyethylene glycol-derived mTHPC: a comparative study on human tumour xenografts
The photosensitizing properties of m-tetrahydroxyphenylchlorin (mTHPC) and polyethylene glycol-derivatized mTHPC (pegylated mTHPC) were compared in nude mice bearing human malignant mesothelioma, squamous cell carcinoma and adenocarcinoma xenografts. Laser light (20 J/cm2) at 652 nm was delivered to the tumour (surface irradiance) and to an equal-sized area of the hind leg of the animals after i.p. administration of 0.1 mg/kg body weight mTHPC and an equimolar dose of pegylated mTHPC, respectively. The extent of tumour necrosis and normal tissue injury was assessed by histology. Both mTHPC and pegylated mTHPC catalyse photosensitized necrosis in mesothelioma xenografts at drug-light intervals of 1–4 days. The onset of action of pegylated mTHPC seemed slower but significantly exceeds that of mTHPC by days 3 and 4 with the greatest difference being noted at day 4. Pegylated mTHPC also induced significantly larger photonecrosis than mTHPC in squamous cell xenografts but not in adenocarcinoma at day 4, where mTHPC showed greatest activity. The degree of necrosis induced by pegylated mTHPC was the same for all three xenografts. mTHPC led to necrosis of skin and underlying muscle at a drug-light interval of 1 day but minor histological changes only at drug-light intervals from 2–4 days. In contrast, pegylated mTHPC did not result in histologically detectable changes in normal tissues under the same treatment conditions at any drug-light interval assessed. In this study, pegylated mTHPC had advantages as a photosensitizer compared to mTHPC
Internal Conditions of Accreting White Dwarfs
We explain the physics of compressional heating of the deep interior of an
accreting white dwarf (WD) at accretion rates low enough so that the
accumulated hydrogen burns unstably and initiates a classical nova (CN). In
this limit, the WD core temperature (T_c) reaches an equilibrium value (T_c,eq)
after accreting an amount of mass much less than the WD's mass. Once this
equilibrium is reached, the compressional heating from within the envelope
exits the surface. This equilibrium yields useful relations between the WD
surface temperature, accretion rate and mass that can be employed to measure
accretion rates from observed WD effective temperatures, thus testing binary
evolution models for cataclysmic variables.Comment: 4 pages, 1 figure, uses CRCKAPB.sty (included); to appear in the
`NATO Science Series II - Mathematics, Physics and Chemistry', Kluwer
Academic Publisher
The supersoft X-ray source in V5116 Sgr I. The high resolution spectra
Classical novae occur on the surface of an accreting white dwarf in a binary
system. After ejection of a fraction of the envelope and when the expanding
shell becomes optically thin to X-rays, a bright source of supersoft X-rays
arises, powered by residual H burning on the surface of the white dwarf. While
the general picture of the nova event is well established, the details and
balance of accretion and ejection processes in classical novae are still full
of unknowns. The long-term balance of accreted matter is of special interest
for massive accreting white dwarfs, which may be promising supernova Ia
progenitor candidates. V5116 Sgr was observed as a bright and variable
supersoft X-ray source by XMM-Newton 610~days after outburst. The light curve
showed a periodicity consistent with the orbital period. During one third of
the orbit the luminosity was a factor of seven brighter than during the other
two thirds of the orbital period. In the present work we aim to disentangle the
X-ray spectral components of V5116 Sgr and their variability. We present the
high resolution spectra obtained with XMM-Newton RGS and Chandra LETGS/HRC-S in
March and August 2007. The grating spectrum during the periods of high-flux
shows a typical hot white dwarf atmosphere dominated by absorption lines of N
VI and N VII. During the low-flux periods, the spectrum is dominated by an
atmosphere with the same temperature as during the high-flux period, but with
several emission features superimposed. Some of the emission lines are well
modeled with an optically thin plasma in collisional equilibrium, rich in C and
N, which also explains some excess in the spectra of the high-flux period. No
velocity shifts are observed in the absorption lines, with an upper limit set
by the spectral resolution of 500 km/s, consistent with the expectation of a
non-expanding atmosphere so late in the evolution of the post-nova.Comment: 12 pages, 15 figures, 4 tables; accepted for publication in Astronomy
and Astrophysic
Swift observations of the X-ray and UV evolution of V2491 Cyg (Nova Cyg 2008 No. 2)
We present extensive, high-density Swift observations of V2491 Cyg (Nova Cyg
2008 No. 2). Observing the X-ray emission from only one day after the nova
discovery, the source is followed through the initial brightening, the
Super-Soft Source phase and back to the pre-outburst flux level. The evolution
of the spectrum throughout the outburst is demonstrated. The UV and X-ray
light-curves follow very different paths, although changes occur in them around
the same times, indicating a link between the bands. Flickering in the
late-time X-ray data indicates the resumption of accretion.
We show that if the white dwarf is magnetic, it would be among the most
magnetic known; the lack of a periodic signal in our later data argues against
a magnetic white dwarf, however. We also discuss the possibility that V2491 Cyg
is a recurrent nova, providing recurrence timescale estimates.Comment: 12 pages, 8 figure (2 in colour), accepted for publication in MNRA
Der frühe Beginn der Zwangsstörung
Einleitung: Die vorliegende Untersuchung geht der Fragestellung nach, ob sich eine Zwangsstörung, die bereits
im Kindes- bzw. Jugendalter beginnt, von einer Zwangsstörung, die erst im Erwachsenenalter beginnt, hinsichtlich Schweregrad und Symptomatik unterscheidet. Patienten und Methoden: Eine Stichprobe von 370 Patienten
mit Zwangsstörung (ICD-10 F42), die sich zwischen 1998
und 2002 stationär in der Psychosomatischen Klinik Windach
befanden, wurde in eine Early-Onset-Gruppe (Störungsbeginn ≤15 Jahre) und in eine Late-Onset-Gruppe (Störungsbeginn ≥16 Jahre) aufgeteilt. Die Gruppen wurden über ICD-10-Diagnosen und Y-BOCSWerte verglichen. Ergebnisse: Beim Schweregrad zeigte sich, dass 20,5% der Early-Onset-Gruppe, aber lediglich 8,7% der Late-Onset-Gruppe unter einer «massiven Zwangsstörung» leiden. Bei der Symptomatik zeigte
sich, dass die Early-Onset-Gruppe häufiger die Diagnose
«Zwangsgedanken und -handlungen gemischt» (76,9%)erhält als die Late-Onset-Gruppe (61,8%). Außerdem nennt die Early-Onset-Gruppe sowohl für die Gegenwart als auch für die Vergangenheit mehr Symptome als die Late-Onset-Gruppe (Gegenwart 8,2 vs. 7,0; Vergangenheit 5,5 vs. 3,9 Symptomgruppen). Weiter ergaben sich inhaltliche Unterschiede der Zwangsgedanken und Zwangshandlungen. Schlussfolgerungen: Early-Onset-Patienten scheinen häufiger von einer massiven Form der Zwangsstörung und einer größeren Symptomvielfalt betroffen zu sein als Late-Onset-Patienten. Ob es sich bei der Zwangsstörung mit Beginn im Kindes- und Jugendalter um einen abgrenzbaren Subtypus handelt, konnte jedoch in dieser Untersuchung nicht eindeutig geklärt werden und bedarf weiterer Forschungen.Introduction: This study investigates if obsessive compulsive disorder with early onset differs in severity and
symptomatology from that with late onset. Patients and
Methods: A sample of 370 patients with obsessive compulsive
disorder (OCD; ICD 10 F42) who received in-patient
treatment at the psychosomatic clinic of Windach between 1998 and 2002 were divided into an early-onset group (onset ≤15 years) and a late-onset group (onset ≥16 years). Groups were compared regarding ICD-10 diagnosis and Y-BOCS scores. Results: Considering severity of the disorder 20.5% of the early-onset group but merely 8.7% of the late-onset group suffered from an extreme form of OCD. With respect to symptomatology, the early-onset group was diagnosed with ‘obsessions and compulsions, mixed’ (76.9%) more often than the lateonset group (61.8%). Also, the early-onset group reported a wider variety of symptoms both for the present and for the past than the late-onset group (present 8,2 vs 7.0; past 5.5 vs 3.9 types of symptoms). There were also differences in the content of rumination and types of compulsive rituals. Conclusions: Patients with early-onset
OCD seem to be more frequently affected by an extreme form of OCD and to experience a higher variety of symptoms than patients with late-onset OCD. If early-onset OCD can be considered a distinct subtype could not be answered unequivocally by the results of this study. This question needs additional research
Classification and Analysis of Regulatory Pathways Using Graph Property, Biochemical and Physicochemical Property, and Functional Property
Given a regulatory pathway system consisting of a set of proteins, can we predict which pathway class it belongs to? Such a problem is closely related to the biological function of the pathway in cells and hence is quite fundamental and essential in systems biology and proteomics. This is also an extremely difficult and challenging problem due to its complexity. To address this problem, a novel approach was developed that can be used to predict query pathways among the following six functional categories: (i) “Metabolism”, (ii) “Genetic Information Processing”, (iii) “Environmental Information Processing”, (iv) “Cellular Processes”, (v) “Organismal Systems”, and (vi) “Human Diseases”. The prediction method was established trough the following procedures: (i) according to the general form of pseudo amino acid composition (PseAAC), each of the pathways concerned is formulated as a 5570-D (dimensional) vector; (ii) each of components in the 5570-D vector was derived by a series of feature extractions from the pathway system according to its graphic property, biochemical and physicochemical property, as well as functional property; (iii) the minimum redundancy maximum relevance (mRMR) method was adopted to operate the prediction. A cross-validation by the jackknife test on a benchmark dataset consisting of 146 regulatory pathways indicated that an overall success rate of 78.8% was achieved by our method in identifying query pathways among the above six classes, indicating the outcome is quite promising and encouraging. To the best of our knowledge, the current study represents the first effort in attempting to identity the type of a pathway system or its biological function. It is anticipated that our report may stimulate a series of follow-up investigations in this new and challenging area
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