Work in large part on Leishmania major in the 1980s identified two distinct apparently counter-regulatory CD4(+) T cell populations, T helper (h)1 and Th2, that controlled resistance/susceptibility to infection respectively. However, the generation of IL-4(-/-) mice in the 1990s questioned the paramount role of this Th2 archetypal cytokine in the non-healing response to Leishmania infection. The more recent characterization of CD4(+) T cell regulatory populations and further effector CD4(+) T helper populations, Th17, Th9, and T follicular (f)h cells as well as the acknowledged plasticity in T helper cell function has further added to the complexity of host pathogen interactions. These interactions are complicated by the multiplicity of cells that respond to CD4(+) T cell subset signatory cytokines, as well as the diversity of Leishmania species that are often subject to significantly different immune-regulatory controls. In this article we review current knowledge with regard to the role of CD4(+) T cells and their products during Leishmania infection. In particular we update on our studies using conditional IL-4Rα gene-deficient mice that have allowed dissection of the cell interplay dictating the disease outcomes of the major Leishmania species infecting humans.

Blue mussels (Mytilus edulis) accumulate and biotransform arsenic (As) to a larger variety of arsenicals than most seafood. Eight volunteers ingested a test meal consisting of 150g blue mussel (680μg As), followed by 72h with an identical, low As controlled diet and full urine sampling. We provide a complete speciation, with individual patterns, of urinary As excretion. Total As (tAs) urinary excretion was 328±47μg, whereof arsenobetaine (AB) and dimethylarsinate (DMA) accounted for 66% and 21%, respectively. Fifteen minor urinary arsenicals were quantified with inductively coupled plasma mass spectrometry (ICPMS) coupled to reverse-phase, anion and cation-exchange high performance liquid chromatography (HPLC). Thio-arsenicals and non-thio minor arsenicals (including inorganic As (iAs) and methylarsonate (MA)) contributed 10% and 7% of the total sum of species excretion, respectively, but there were large individual differences in the excretion patterns. Apparently, formation of thio-arsenicals was negatively correlated to AB formation and excretion, possibly indicating a metabolic interrelationship. The results may be of toxicological relevance since DMA and MA have been classified as possibly carcinogenic, and six of the excreted As species were thio-arsenicals which recently have been recognized as toxic, while iAs toxicity is well known.

A search for a Higgs boson in the four-lepton decay channel H→ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range of 110<m_{H}<600  GeV. The analysis uses data corresponding to an integrated luminosity of 4.7  fb^{-1} recorded by the CMS detector in pp collisions at sqrt[s]=7  TeV from the LHC. Seventy-two events are observed with four-lepton invariant mass m_{4ℓ}>100  GeV (with 13 below 160 GeV), while 67.1±6.0 (9.5±1.3) events are expected from background. The four-lepton mass distribution is consistent with the expectation of standard model background production of ZZ pairs. Upper limits at 95% confidence level exclude the standard model Higgs boson in the ranges of 134-158 GeV, 180-305 GeV, and 340-465 GeV. Small excesses of events are observed around masses of 119, 126, and 320 GeV, making the observed limits weaker than expected in the absence of a signal.