Deep analysis of CD4 T cells in the rhesus CNS during SIV infection

Virologic suppression with antiretroviral therapy (ART) has significantly improved health outcomes for people living with HIV, yet challenges related to chronic inflammation in the central nervous system (CNS)—known as Neuro-HIV- persist. As primary targets for HIV-1 with the ability to survey and populate the CNS and interact with myeloid cells to co-ordinate neuroinflammation, CD4 T cells are pivotal in Neuro-HIV. Despite their importance, our understanding of CD4 T cell distribution in virus-targeted CNS tissues, their response to infection, and potential recovery following initiation of ART remain limited. To address these gaps, we studied ten SIVmac251-infected rhesus macaques using an ART regimen simulating suboptimal adherence. We evaluated four macaques during the acute phase pre-ART and six during the chronic phase. Our data revealed that HIV target CCR5+ CD4 T cells inhabit both the brain parenchyma and adjacent CNS tissues, encompassing choroid plexus stroma, dura mater, and the skull bone marrow. Aligning with the known susceptibility of CCR5+ CD4 T cells to viral infection and their presence within the CNS, high levels of viral RNA were detected in the brain parenchyma and its border tissues during acute SIV infection. Single-cell RNA sequencing of CD45+ cells from the brain revealed colocalization of viral transcripts within CD4 clusters and significant activation of antiviral molecules and specific effector programs within T cells, indicating CNS CD4 T cell engagement during infection. Acute infection led to marked imbalance in the CNS CD4/CD8 ratio which persisted into the chronic phase. These observations underscore the functional involvement of CD4 T cells within the CNS during SIV infection, enhancing our understanding of their role in establishing CNS viral presence. Our findings offer insights for potential T cell-focused interventions while underscoring the challenges in eradicating HIV from the CNS, particularly in the context of sub-optimal ART

Possible origins of macroscopic left-right asymmetry in organisms

I consider the microscopic mechanisms by which a particular left-right (L/R) asymmetry is generated at the organism level from the microscopic handedness of cytoskeletal molecules. In light of a fundamental symmetry principle, the typical pattern-formation mechanisms of diffusion plus regulation cannot implement the "right-hand rule"; at the microscopic level, the cell's cytoskeleton of chiral filaments seems always to be involved, usually in collective states driven by polymerization forces or molecular motors. It seems particularly easy for handedness to emerge in a shear or rotation in the background of an effectively two-dimensional system, such as the cell membrane or a layer of cells, as this requires no pre-existing axis apart from the layer normal. I detail a scenario involving actin/myosin layers in snails and in C. elegans, and also one about the microtubule layer in plant cells. I also survey the other examples that I am aware of, such as the emergence of handedness such as the emergence of handedness in neurons, in eukaryote cell motility, and in non-flagellated bacteria.Comment: 42 pages, 6 figures, resubmitted to J. Stat. Phys. special issue. Major rewrite, rearranged sections/subsections, new Fig 3 + 6, new physics in Sec 2.4 and 3.4.1, added Sec 5 and subsections of Sec

Measurement of σ(Λb)/σ(B0)×BR(Λb→Λcπ−)/BR(B0→D+π−)\sigma(\Lambda_b)/\sigma(B^0) \times BR(\Lambda_b\to\Lambda_c\pi^-) / BR(B^0\to D^+\pi^-) in ppˉp\bar{p} Collisions at s=1.96\sqrt{s}=1.96 TeV

We present the first observation of the baryon decay $\Lambda_b\to\Lambda_c\pi^-$ followed by $\Lambda_c\to p K^-\pi^+$ in 106 pb-1 of $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV in the CDF experiment. In order to reduce systematic error, the measured rate for $\Lambda_b$ decay is normalized to the kinematically similar meson decay $B^0\to D^+\pi^-$ followed by $D^+\to\pi^+K^-\pi^+$. We report the ratio of production cross sections ($\sigma$) times the ratio of branching fractions (BR) for the momentum region integrated above $p_T > 6$ GeV/c and pseudorapidity range $|\eta| < 1.3$: $\sigma(p\bar{p}\to \Lambda_b X) / \sigma (p\bar{p}\to B^0 X) \times BR(\Lambda_b\to\Lambda_c\pi^-) / BR(B^0\to D^+\pi^-) = 0.82 \pm 0.08(stat) \pm 0.11(syst) \pm 0.22 (BR(\Lambda_c\to p K^-\pi^+))$.Comment: Submitted to Phys.Rev.Let

Measurement of the ttbar Production Cross Section in ppbar collisions at sqrt s = 1.96 TeV in the All Hadronic Decay Mode

We report a measurement of the ttbar production cross section using the CDF-II detector at the Fermilab Tevatron. The analysis is performed using 311 pb-1 of ppbar collisions at sqrt(s)=1.96 TeV. The data consist of events selected with six or more hadronic jets with additional kinematic requirements. At least one of these jets must be identified as a b-quark jet by the reconstruction of a secondary vertex. The cross section is measured to be sigma(tbart)=7.5+-2.1(stat.)+3.3-2.2(syst.)+0.5-0.4(lumi.) pb, which is consistent with the standard model prediction.Comment: By CDF collaboratio

Track A Basic Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd

Amniotic fluid creatinine, uric acid and urea as indices of gestational age

Acta Obstetricia et Gynecologica Scandinavica524323-326AOGS