Constraints on an annihilation signal from a core of constant dark matter density around the milky way center with H.E.S.S

An annihilation signal of dark matter is searched for from the central region of the Milky Way. Data acquired in dedicated on-off observations of the Galactic center region with H.E.S.S. are analyzed for this purpose. No significant signal is found in a total of ∼9  h of on-off observations. Upper limits on the velocity averaged cross section, ⟨σv⟩, for the annihilation of dark matter particles with masses in the range of ∼300  GeV to ∼10  TeV are derived. In contrast to previous constraints derived from observations of the Galactic center region, the constraints that are derived here apply also under the assumption of a central core of constant dark matter density around the center of the Galaxy. Values of ⟨σv⟩ that are larger than 3×10^{-24}  cm^{3}/s are excluded for dark matter particles with masses between ∼1 and ∼4  TeV at 95% C.L. if the radius of the central dark matter density core does not exceed 500 pc. This is the strongest constraint that is derived on ⟨σv⟩ for annihilating TeV mass dark matter without the assumption of a centrally cusped dark matter density distribution in the search region.

Prognostic significance of FLT3 internal tandem duplication, nucleophosmin 1, and CEBPA gene mutations for acute myeloid leukemia patients with normal karyotype and younger than 60 years: a systematic review and meta-analysis

Diagnosis and classification of acute myeloid leukemia (AML) are based on morphology and genetics. An increasing number of gene mutations have been found, and some are used for risk classification in AML patients with normal karyotype (cytogenetically normal (CN)-AML). In this systematic review and meta-analysis, we examined three frequent mutations in CN-AML: mutations of fms-related tyrosine kinase 3 (FLT3-ITD), mutated nucleophosmin (NPM1), and mutations of the CCAAT enhancer-binding protein alpha (CEBPA) gene. A systematic literature search of publications listed in the electronic databases (Embase, Pubmed, Healthstar, BIOSIS, ISI Web of Knowledge and Cochrane) from 2000 up to March 2012 was performed (Fig. 1). Nineteen studies were included and qualitatively analyzed. Two to four studies entered the quantitative meta-analysis incorporating 1,378 to 1,942 patients with CN-AML. Meta-analysis for overall survival (OS) and relapse-free survival (RFS) showed FLT3-ITD to predict an unfavorable prognosis, with hazard ratios (HR) of 1.86 and 1.75, respectively. In contrast, meta-analysis of the impact of NPM1 and CEBPA mutations on OS yielded an HR of 0.56 for each mutation, while analysis of impact on RFS produced HRs of 0.37 and 0.42, respectively. This systematic review and meta-analysis aimed to evaluate the prognostic value of mutations in the NPM1, CEBPA, and FLT3 genes. FLT3-ITD was associated with worse prognosis, whereas mutations in NPM1 and CEBPA genes were associated with a favorable prognosis.

[Trauma centre admission of severely injured or critically ill patients: comparison of estimated and real arrival times]

BACKGROUND

During early in-hospital management of the arriving trauma patient the timing of the trauma team alert is an important organisational step. To evaluate the accordance of the estimated and the real arriving time we performed a retrospective data analysis at a level I German trauma centre.

METHODS

Retrospective data analysis. Trauma team alerts from September 2010 until March 2011 were analysed. According to the hospitals pre-alert algorithm, trauma team alert took place 10 min before the estimated time of arrival.

RESULTS

There were 165 trauma team alerts included in the analysis. The estimated arrival time coincided with the real arrival time in less than 10 % of cases. In 76 % of the cases, the patient arrived in an acceptable time frame with the trauma team waiting less than 14 min. In 3 % of the cases, the patient arrived prior to the trauma team.

CONCLUSION

An exact estimation of the arrival time is rare. With a trauma team alert 10 min prior to the estimated time of arrival, an acceptable waiting time can be achieved. Arrival of the patient prior to the trauma team can be avoided.

[Botulinum toxin therapy for spasmodic torticollis: medical and non-medical adjunct treatment]

BACKGROUND

Spasmodic torticollis patients were investigated with respect to the number of adjunct treatments used before and after the introduction of botulinum toxin therapy (Btx). The study was designed in a similar way to an earlier investigation by Birner et al. (Nervenarzt 70:903-908, 1999).

MATERIAL AND METHODS

A total of 247 patients with idiopathic spasmodic torticollis were assessed at three time points for the diagnosis: before 1988 (n = 63), between 1989 and 1998 (n = 107) and after 1999 (n = 77).

RESULTS

Independent of the year of diagnosis patients underwent a mean of 14.3 different treatments. In addition to Btx most of the patients were subjected to massage, physiotherapy, medication and a large number of non-medical treatments including praying. No associations to clinical or personal variables were found. Those patients with emotional disorders prior to onset of dystonia displayed a higher rate of medical and non-medical treatments in addition to Btx.

CONCLUSIONS

The results confirmed those found by Birner et al.. In order to enhance compliance patients should undergo psychoeducation with respect to illness behaviour and specific history taking with respect to emotional disorders prior to dystonia.

Perivascular fatty tissue at the brachial artery is linked to insulin resistance but not to local endothelial dysfunction

AIMS/HYPOTHESIS

Different ectopic fat depots, such as visceral or hepatic fat, are known to affect whole body insulin sensitivity. It has recently been hypothesised that differences in perivascular adipose tissue (PVAT) mass around resistance vessels may also contribute to insulin resistance, possibly via direct vascular effects leading to reduced capillary cross-sectional area in the muscle, which in turn affects muscular blood flow and glucose uptake. Based on this, the aim of the present study was to test whether PVAT around conduit arteries (i.e. the brachial artery) influences NO bioavailability, expressed as flow-mediated dilation (FMD), or insulin sensitivity in humans in vivo.

METHODS

Insulin sensitivity was measured by OGTT in all 95 participants (59 women, 36 men; median age 47 years, range 19-66 years) and by the gold standard, a euglycaemic-hyperinsulinaemic clamp, in a randomly selected subgroup of 33 participants. Quantification of the different fat compartments, including PVAT around the brachial artery, was achieved by high-resolution magnetic resonance imaging (1.5 T). Blood flow and FMD were measured at the brachial artery using high-resolution (13 MHz) ultrasound, after 5 min of forearm occlusion.

RESULTS

PVAT was negatively correlated with insulin sensitivity and the post-ischaemic increase in blood flow. The association between PVAT and insulin sensitivity (r = -0.54, beta = -0.37, p = 0.009) was independent of age, sex, visceral adipose tissue, liver fat, BMI and further cardiovascular risk factors. No correlation could be detected between PVAT and local endothelial function. However, we observed an independent association between PVAT and post-ischaemic increase in blood flow (r = -0.241; beta = -1.69; p = 0.02).

CONCLUSIONS/INTERPRETATION

PVAT seems to play an independent role in the pathogenesis of insulin resistance. This may be due to direct vascular effects influencing muscular blood flow.

Flow cytometric analysis of lymphocyte subpopulations in bronchoalveolar lavage fluid after repeated ozone exposure

As known from studies in animal and human subjects, ozone can exert effects on the immune response including allergic sensitisation and allergen responsiveness. The objective of the present study was to assess the changes in lymphocyte subsets in bronchoalveolar lavage fluid (BALF) after single and repeated ozone exposures. Twenty-three healthy subjects underwent single exposures to 200 ppb ozone or filtered air (FA), as well as repeated exposures to 200 ppb ozone on four consecutive days, each during 4 h of intermittent exercise. Bronchoalveolar lavage was performed 20 h after the single exposure or the last of the repeated exposures. Lymphocytes were identified by sideward scatter and CD45 expression, and their subsets by eight different panels of antibodies. Checksums were calculated to assess the validity of the results. The percentage and the absolute number of lymphocytes, mostly comprising T-lymphocytes (CD2+; overall mean 98.8%), increased after single (P < 0.05; each), but not after repeated ozone exposure, compared with FA (7.4 vs 5.8 vs 6.5%; 680 vs 419 vs 301 x 10(3)). In addition, we observed small but statistically significant changes in the proportions of lymphocyte subpopulations. The percentage of CD4+ lymphocytes increased after single (P < 0.05) and repeated ozone exposure (P < 0.01), whereas the percentage of CD8+ cells decreased after repeated exposure (P < 0.05). The proportion of activated lymphocytes (CD25+) was elevated after repeated, compared with single, ozone exposure (P < 0.01), and the percentages of natural killer (NK) cells were decreased after both single (P < 0.05) and repeated (P < 0.01) exposures. Our data suggest that single but not repeated ozone exposures cause a change in absolute numbers of lymphocytes in BALF, whereas the proportions of lymphocyte subsets are affected by single as well as repeated exposures.

Flow cytometric analysis of the effect of dithiothreitol on leukocyte surface markers

Pretreatment with dithiothreitol (DTT) is necessary to dissolve mucus in samples of induced sputum prior to analysis. However, DTT may affect cell surface markers which are essential for lymphocyte subtyping. Therefore, the aim of this study was to evaluate the effect of DTT on an appropriate panel of surface markers. Peripheral blood leukocytes were used because these cells, in contrast to sputum cells, could be obtained without DTT treatment. Peripheral blood from healthy donors was incubated with either DTT according to standard sputum procedures or phosphate-buffered saline (PBS), washed and incubated with fluorochrome-labelled antibodies. After lysis of erythrocytes, analysis was performed using a calibrated flow cytometer. Leukocyte populations were identified by their light scattering properties. For analysis, fluorescence intensity was compared between DTT- and PBS-treated samples. After treatment with DTT, fluorescence intensity was significantly increased in CD16-positive granulocytes; it was reduced in CD2-positive lymphocytes, CD45-positive lymphocytes and CD14-positive monocytes (p < or = 0.001). These changes occurred in all samples. The fluorescence intensity of CD3-, CD4-, CD8-, CD19-, CD56- and histocompatibility leukocyte antigen DR-positive lymphocytes was not altered by DTT. However, there were statistically significant (p<0.001), although small, changes in the percentages of leukocytes. The present data demonstrate that, although dithiothreitol as used in sputum analysis affects some surface markers of peripheral blood leukocytes, comparability between samples concerning lymphocyte surface markers is preserved. Therefore, it is suggested that treatment of sputum samples with dithiothreitol does not invalidate the immunocytochemical analysis of lymphocytes.

Flash Heating of Circumstellar Clouds by Gamma-Ray Bursts

The blast-wave model for gamma-ray bursts (GRBs) has been called into question by observations of spectra from GRBs that are harder than can be produced through optically thin synchrotron emission. If GRBs originate from the collapse of massive stars, then circumstellar clouds near burst sources will be illuminated by intense gamma radiation, and the electrons in these clouds will be rapidly scattered to energies as large as several hundred keV. Low-energy photons that subsequently pass through the hot plasma will be scattered to higher energies, hardening the intrinsic spectrum. This effect resolves the "line-of-death" objection to the synchrotron shock model. Illuminated clouds near GRBs will form relativistic plasmas containing large numbers of electron-positron pairs that can be detected within approximately 1-2 days of the explosion before expanding and dissipating. Localized regions of pair annihilation radiation in the Galaxy would reveal past GRB explosions.

Effect of sodium bentonite on the performance and blood variables of broiler chickens intoxicated with aflatoxins

1. This study was conducted to evaluate the protective effect of natural sodium bentonite (NaB) in the prevention of toxic effects of aflatoxins. Five hundred and twenty-eight 1-d-old Ross male broiler chickens were housed in pens (22 chickens per pen) for 42 d. There were 3 inclusion rates of NaB (0, 2.5, and 5 g/kg) and 2 of aflatoxins (0 and 3 mg/kg food). Each treatment had 4 replicates of 22 chickens. 2. All chickens treated with aflatoxin and without bentonite were adversely affected. NaB treatment at 5.0 g/kg improved body weights at 42 d of age by 31.3%, increased food intake by 23.8% and improved productive efficiency by 40.1%. Weights of liver, heart, pancreas and crop and biochemical variables were not affected by dietary NaB. However, serum phosphorous concentration was reduced by 30% compared with chickens that received aflatoxin. 3. NaB caused no adverse effects on chickens that did not receive aflatoxin. 4. It is concluded that NaB at pH 7.9 partially neutralises the effects of aflatoxins on broiler chickens when included at 5.0 g/kg in the diet.

Pharmacokinetic study of dipyrone metabolite 4-MAA in the horse and possible implications for doping control

The pharmacokinetic behaviour of dipyrone metabolite 4-MAA in serum was determined in seven horses of different breeds after a single intravenous dose administration. A biexponential formula was fitted to the serum concentration vs. time data. The median half-life of the elimination phase (t1/2 beta) was 4.85 h (range 5.04 h), the median volume of distribution (Vd(area)) was 1.85 L/kg (range 3.2 L/kg) and median of total clearance was 4.0 mL/min/kg (range 2.3 mL/min/kg).

HIV-1 protease inhibits its homologous reverse transcriptase by protein-protein interaction

The reading frame of the HIV-1 pol gene, encoding protease (PR) and reverse transcriptase (RT), including RNase H as well as integrase, was fused to the bacterialbeta-galactosidase gene and overexpressed in Escherichia coli cells. The resulting fusion protein was cleaved autocatalytically leading to PR, RT and integrase. Immunoprecipitations of bacterial crude extracts with anti-RT antibodies precipitated both RT and PR. Co-precipitation of PR and RT was also observed with anti-PR antibodies, strongly suggesting a physical interaction between fully processed RT and PR within the bacterial cell. Physical interactions were confirmed with purified components by means of an ELISA assay. Furthermore, purified PR inhibited the DNA synthesis activity of purified RT, while its RNase H activity remained unaffected. The type of inhibition was uncompetitive with respect to poly(rA).oligo(dT); the inhibition constant was 50-100 nM. A possible physiological significance of this type of interaction is discussed.

Glucose uptake and lumped constant variability in normal human hearts determined with [18F]fluorodeoxyglucose

BACKGROUND

Myocardial glucose uptake can be measured with [18F]fluoro-2-deoxyglucose (FDG) and positron emission tomography (PET). However, changes of myocardial metabolism may alter the ratio between the net rates of FDG and glucose uptake, known as the lumped constant. We tested the hypothesis that the variability of the lumped constant determined in animals explains the disagreement between human net myocardial glucose uptake calculated from aortocoronary sinus deficits and measured with PET.

METHODS AND RESULTS

In the three-compartment model of glucose transfer into cells, the lumped constant is a function of the relationship between the net and the unidirectional rates of uptake of glucose and glucose tracers such as FDG. Using this principle, validated in the human brain and the animal heart under experimental conditions, we estimated the lumped constant of the human heart by PET in 10 healthy men under several metabolic conditions established by altering the circulating insulin level during a euglycemic clamp and with somatostatin and heparin infusions. The lumped constant varied systematically between 0.44 and 1.35. At insulin levels below 100 pmol/L, free fatty acids were inversely related to serum insulin levels and the lumped constant increased linearly with serum insulin concentration. At insulin levels above 100 pmol/L, free fatty acids were suppressed and the lumped constant varied in inverse proportion to the insulin level. When the lumped constant was estimated in this manner, net myocardial glucose uptake agreed with that determined in previous measurements of blood flow and aortocoronary sinus deficit.

CONCLUSION

In the intact human organism, the cardiac lumped constant varies with the metabolic condition, as predicted from studies of the brain and animal heart under experimental conditions.

Effect of beta 1 adrenergic receptor blockade on myocardial blood flow and vasodilatory capacity

The beta 1 receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of beta 1 receptor blockade on hyperemic MBF is unknown.

METHODS

To evaluate the effect of selective beta 1 receptor blockade on MBF at rest and during dipyridamole induced hyperemia, 10 healthy volunteers (8 men, 2 women, mean age 24 +/- 5 yr) were studied using 13N-ammonia PET (two-compartment model) under control conditions and again during metoprolol (50 mg orally 12 hr and 1 hr before the study).

RESULTS

The resting rate pressure product (6628 +/- 504 versus 5225 +/- 807) and heart rate (63 +/- 6-54 +/- 5 bpm) declined during metoprolol (p < 0.05). Similarly, heart rate and rate pressure product declined from the baseline dipyridamole study to dipyridamole plus metoprolol (p < 0.05). Resting MBF declined in proportion to cardiac work by approximately 20% from 0.61 +/- 0.09-0.51 +/- 0.10 ml/g/min (p < 0.05). In contrast, hyperemic MBF increased when metoprolol was added to dipyridamole (1.86 +/- 0.27-2.34 +/- 0.45 ml/g/min; p < 0.05). The decrease in resting MBF together with the increase in hyperemic MBF resulted in a significant increase in the myocardial flow reserve during metoprolol (3.14 +/- 0.80-4.61 +/- 0.68; p < 0.01).

CONCLUSION

The beta 1 receptor blockade increases coronary vasodilatory capacity and myocardial flow reserve. However, the mechanisms accounting for this finding remain uncertain.