Levels of CD40 expression on dendritic cells dictate tumour growth or regression

Tumour regression requires activation of T cells. It has been shown that the interaction between T cell-expressed CD40-ligand (CD40-L) and antigen-presenting cell-expressed CD40 plays a crucial role in T cell activation. CD40-L- or CD40-deficient mice are susceptible to tumour growth. CD40-based therapies are also shown to control tumour growth significantly, suggesting that CD40-CD40-L interaction induces anti-tumour T cell responses and tumour regression. We demonstrate that the anti-tumour T cell response can be modulated reciprocally as a function of the levels of CD40 expression. At low expression levels, CD40 promotes tumour growth; at higher expression levels, CD40 induces tumour-regressing T cell response. Dendritic cells (DC) sorted onto major histocompatibility complex (MHC)-II expression are found to be similar in CD40 and CD80 expression. The MHC-II(hi)/CD40(hi) DC induce interleukin (IL)-12-dominated and T helper 1 (Th1)-type response, whereas MHC-II(lo)/CD40(lo) DC promote high IL-10 and Th2-type T cells. The T cells induced by these DC also differ in terms of regulatory T cell markers, lymphocyte activation gene-3 (LAG-3) and glucocorticoid-induced tumour necrosis factor (TNF) receptor family-related gene (GITR). Thus, we report for the first time that CD40-induced effector T cell response depends on CD40 expression levels in vivo.

Effect of electrochemical oxidation of activated carbon fiber on competitive and noncompetitive sorption of trace toxic metal ions from aqueous solution

A viscose-rayon-based activated carbon cloth (ACC) was electrochemically oxidized to enhance its cation sorption capacity for comparison with as-received ACC. The ACCs were characterized by sodium capacity measurement, pH titration, zeta potential measurement, elemental analysis, Brunauer-Emmet-Teller surface area, and pore size distribution. Batch sorption experiments showed that electrochemically oxidized ACC (EO) is more effective for the removal of lead and copper ions compared to unoxidized ACC (UO) for both competitive and noncompetitive sorption. For electrochemically oxidized fibers the copper and lead sorption capacities of ACC increased 17 and 4 times, respectively, for noncompetitive sorption and 8.8 and 8.6 times, respectively, for competitive sorption. However, reduction in the sorption capacities for both metals was observed for the competitive sorption. The sorption of lead and copper onto EO was by ion exchange, while that onto UO was likely to be due to surface complex formation. The affinity order of the two metal ions sorbed by UO and EO is Pb(2+)>Cu(2+). The effect of pH on sorption isotherms indicated that metal uptake increased with an increase in solution pH.

Sorption of atrazine on conventional and surface modified activated carbons

The sorption of atrazine from water has been studied using a conventional activated carbon, F400, an annealed carbon sample, F400AN, and an aminated carbon sample, F400NH(2). Characterisation of the carbon samples showed that sample F400NH(2) had the highest proportion of micropores, but had the lowest values of point of zero charge (PZC) and iso-electric point (IEP). This was attributed to the existence of a high proportion of oxygen containing functional groups. Sorption data showed that sample F400AN was superior in the sorption of atrazine to samples F400 and F400NH(2). It was noted that pore size distribution alone was not the only contributing factor for the uptake of atrazine onto the activated carbons. The sorption data were fitted well using the Freundlich isotherm. The free energy change showed that sorption of atrazine on activated carbons is a spontaneous process. A pseudo-second order kinetic model was used for analysing the kinetic data, and it was concluded that adsorption of atrazine was controlled by a film diffusion mechanism.

Collectivity and configuration mixing in 186,188Pb and 194Po

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |beta2|=0.29(5) and |beta2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.

Best evidence topic report. Ultrasound placement of needle in three-in-one nerve block

A short cut review was carried out to establish whether ultrasound placement of three-in-one block is better than placement using a nerve stimulator. 137 papers were found, of which two presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. The clinical bottom line is that ultrasound guidance is better than electrical nerve stimulation at obtaining a good quality three in one femoral block.

Effect of surface modification of an engineered activated carbon on the sorption of 2,4-dichlorophenoxy acetic acid and benazolin from water

The performance of a conventional (F400) and a surface modified activated carbon (F400AN) has been investigated for the sorption of benazolin and 2,4-dichlorophenoxy acetic acid (2,4-D) from water. It was observed that the modified carbon, F400AN, which was obtained by annealing the conventional sample had a higher BET surface area (960 m2 g(-1) compared to 790 m2 g(-1)) and it had a higher proportion of micropores. This was attributed to the loss of oxygen containing functional groups during the thermal treatment. Zeta potential and pH titration measurements also showed that acidic functionality had been lost on the F400AN sample. The adsorption data were analysed and were fitted well using the Langmuir isotherm. The modified carbon marginally out-performed the conventional activated carbon for sorption of these two herbicides. Thermodynamic parameters (DeltaG0, DeltaH0, and DeltaS0) were determined and their values indicated that the sorption process was spontaneous and endothermic for both herbicides. A pseudo-second-order kinetic model was employed for analysing the kinetic data. It was concluded that the herbicide sorption process was controlled by a film diffusion mechanism.

Be I isoelectronic ions embedded in hot plasma

The influence of plasma screening on the 2s(2 1)S0-->2s2p(3)p(0)1 intercombination and the 2s(2 1)S0-->2s2p(1)p(0)1 allowed transitions is investigated theoretically for several ions along the isoelectronic sequence (C III, N IV, O V, Si XI, Fe XXIII, and Mo XXXIX). For the case of a weakly coupled hot plasma, multiconfiguration Dirac-Fock computations have been carried out for these ions by considering a (time averaged) Debye-Hückel potential for both the "electron-nucleus" and "electron-electron" interaction. The plasma screening is found to enlarge the 2s(2 1)S0-->2s2p(3)p(0)1 excitation energy uniformly along the Be I isoelectronic sequence, leading to an increasing blueshift of this intercombination line as the nuclear charge is increased. For the 2s(2 1)S0-->2s2p(1)p(0)1 resonance line, in contrast, the transition energy is either blueshifted or redshifted in dependence of the screening parameter and owing to a cancellation of the plasma screening on the electron-nucleus and electron-electron interaction. This interplay of the (external) plasma screening with the internal interactions in the berylliumlike ions leads, for instance, to a shift of the resonance transition from red to blue in going from O V to Si XI ions. Apart from the screening effects on the transition energies, we also investigate their influence on the oscillator strengths and emission rates along the Be I isoelectronic sequence.

Correlating sequential homology of Mce1A, Mce2A, Mce3A and Mce4A with their possible functions in mammalian cell entry of Mycobacterium tuberculosis performing homology modeling

OBJECTIVE

The striking homology of the Mycobacterium tuberculosis mammalian cell entry operons (mce1, mce2, mce3 and mce4) with other mycobacterial species and the proposed role of the mammalian cell entry protein 1A (Mce1A) of M. tuberculosis to facilitate invasion of host cells have led us to look into the finer details of these proteins in order to better understand their structure-function relationship.

DESIGN

We performed sequential alignments and secondary structure predictions of Mce1A, Mce2A, Mce3A and Mce4A, and compared these results with results from homology modeling by fold prediction and threading.

RESULTS

Sequential alignments showed that Mce1A and Mce2A are highly homologous, close to 70%, while the other combinations gave only about 30% similarities. The major parts of the proteins aligned without gaps and there were striking similarities by secondary structure predictions indicating that the proteins would have similar folds and to be alpha/beta proteins like the previously reported Mce1A model based on Colicin N. Fold prediction showed that the best templates for Mce2A were substrate-binding domain of DnaK and slow processing precursor penicillin acylase from Escherichia coli while the alpha-domains of Mce3A and Mce4A could both be modeled using the cytoplasmic domain of serine chemotaxis receptor as template.

CONCLUSION

Although different templates had to be used to model the MceA proteins, functional information may be derived that is relevant for their overall function in M. tuberculosis. The beta-domain is probably involved in binding with the receptors on target cells while the alpha-domain is more likely to be involved in pore formation. As predicted from the folds, Mce3A and Mce4A model structures indicate a lipid bound conformation and therefore may be required in signaling events of the mammalian cell entry process.

Adsorption of arsenic(V) by activated carbon prepared from oat hulls

The efficiency of self-manufactured activated carbon (AC) produced from oat hulls in adsorbing arsenic(V) was tested in a batch reactor. The results indicated that the adsorptive capacity of AC was affected by initial pH value, with adsorption capacity decreasing from 3.09 to 1.57 mg As g(-1) AC when the initial pH values increased from 5 to 8. A modified linear driving force model conjugated with a Langmuir isotherm was created to describe the study's kinetics. The test results show that rapid adsorption and slow adsorption exist simultaneously when AC is used to remove arsenic(V).

Effective charges in the fp shell

Following the heavy-ion fusion-evaporation reaction 32S+24Mg at 95 MeV beam energy the lifetimes of analogue states in the T(z)=+/-1/2 A=51 mirror nuclei 51Fe and 51Mn have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p) approximately 1.15e and epsilon(n) approximately 0.80e.

Mast cells at the host-pathogen interface: host-protection versus immune evasion in leishmaniasis

Infection of a susceptible host with Leishmania, a protozoan parasite, causes the disease leishmaniasis, which is characterized by neutrophil, eosinophil, macrophage, lymphocyte and mast cell infiltration into the infected tissue followed by parasite growth. Although the roles played by other cells in leishmaniasis are known, the role of mast cells remains to be ascertained. Here, we demonstrate that Leishmania regulates mast cell infiltration to the site of infection, mast cell production and mast cell function resulting in differential growth of the parasite in resistant (C57BL/6 or CBA/T6T6) and susceptible (BALB/c) macrophages. An interleukin-3-dependent augmentation in mast cell committed progenitors is observed in BALB/c but not in C57BL/6 mice during Leishmania infection. The mast cell supernatants inhibit IFN-gamma-dependent restriction of Leishmania growth in macrophages in BALB/c mice whereas the reverse phenomenon occurs in C57BL/6 mice. Our data reveals a different facet of host-pathogen interaction.

Right myocardial bridge on CT coronary angiography

Myocardial bridging is a condition where the coronary artery traverses through the myocardium. Although it is not an uncommon finding in left anterior descending coronary artery (LAD), recently we came across a very rare case of right coronary artery (RCA) traversing through the right myocardium on CT coronary angiography.

Relativistic effects in hydrogenlike atoms embedded in Debye plasmas

Spectra of hydrogenlike atoms embedded in a Debye plasma are investigated. The state energies and the transition rates are studied using a fully relativistic formalism based on the Dirac equation. The effect of the plasma is described by introducing an exponential screening to the nuclear Coulomb potential (the Debye screening). Systematic trends with respect to both the nuclear charge and the screening parameter are observed for all calculated quantities. The pattern of splittings of ns(1/2), np(1/2) and np(3/2) is modified in a specific way due to the combined relativity and plasma effect. The transition rates decrease with an increase of the Debye parameter as well as with an increase of Z.