We report measurements of the photon beam asymmetry $\Sigma$ for the reaction $\vec{\gamma} p\to K^+\Sigma^0$(1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected using ...a linearly polarized photon beam in the energy range of 8.2-8.8 GeV incident on a liquid hydrogen target. The beam asymmetry $\Sigma$ was measured as a function of the Mandelstam variable $t$, and a single value of $\Sigma$ was extracted for events produced in the $u$-channel. These are the first exclusive measurements of the photon beam asymmetry $\Sigma$ for the reaction in this energy range. For the $t$-channel, the measured beam asymmetry is close to unity over the $t$-range studied, $-t=(0.1-1.4)~$(GeV/$c$)$^{2}$, with an average value of $\Sigma = 1.00\pm 0.05$. This agrees with theoretical models that describe the reaction via the natural-parity exchange of the $K^{*}$(892) Regge trajectory. A value of $\Sigma = 0.41 \pm 0.09$ is obtained for the $u$-channel integrated up to $-u=2.0$~(GeV/$c$)$^{2}$.
Reactive oxygen species (ROS) may be a major cause of tissue injury in ulcerative colitis (UC). One possible mechanism for ROS-mediated tissue injury is lipid peroxidation. Breath ethane and pentane ...excretion are noninvasive means for measuring peroxidation of omega-3 and omega-6 polyunsaturated fatty acid, respectively. Hence, we measured breath ethane in 17 subjects with active UC and correlated the results with disease severity.
Breath samples for ethane and pentane analysis were collected every 2 weeks, and rectal biopsies were obtained monthly to assess for chemiluminescence, a marker of ROS. Ethane and pentane concentrations (nmol/L) were measured by gas chromatography, and mucosal chemiluminescence was measured spectrophotometrically. Data were compared to control values (C) from healthy subjects. Disease activity was assessed both clinically and endoscopically.
Ethane excretion was significantly elevated in patients (UC, 0.45 +/- 0.04; C, 0.33 +/- 0.06; p = 0.013). Ethane excretion was positively correlated with endoscopic score (r = 0.45; p < 0.05), symptom score (r = 0.34; p < 0.05), disease activity (r = 0.36, p < 0.05), and chemiluminescence (r = 0.65; p < 0.001). Pentane levels did not correlate with any of the clinical measurements. Chemiluminescence in the rectal tissue was positively correlated with endoscopic score (r = 0.71; p < 0.05) and disease activity (r = 0.61; p < 0.01).
Tissue damage in UC may be ROS-induced lipid peroxidation. Disease activity can be assessed noninvasively by breath ethane excretion.
In a randomised phase I trial of a recombinant vaccinia virus vaccine expressing the gp160 envelope gene of the human immunodeficiency virus (HIVAC-1e) 35 healthy, HIV-seronegative males, 31 of whom ...had a history of smallpox immunisation and 4 of whom were vaccinia naive, were vaccinated and then boosted 8 weeks later with HIVAC-1e or standard NY strain vaccinia virus. The frequency, duration, and titre of virus isolation from the vaccination site and occurrence of local side-effects were similar between the two groups of vaccinees. Vaccinia-naive (vac-n) subjects shed virus from the vaccination site for longer and at a higher titre than did vaccinia-primed (vac-p) individuals (19 vs 7 days and 10
7
vs 10
5 pfu/ml, respectively). In-vitro T-cell proliferative responses to one or more HIV antigen preparations developed in 13 of 16 vaccinia-primed subjects inoculated with HIVAC-1e. T-cell responses were, however, transient and in no subject did antibodies to HIV become detectable. The 2 vaccinia-naive subjects vaccinated with HIVAC-1e showed strong T-cell responses to homologous and heterologous strains of whole virus and to recombinant gp160 protein that remained detectable for over a year; antibodies to HIV envelope also developed in both. Recombinant vaccinia virus vaccines induce T-cell priming to the foreign gene products in most individuals. If used as the sole immunising agent they will be most efficacious in vaccinia-naive individuals.
We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. ...We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\sigma /dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/\psi p)$ and cross sections $\sigma(\gamma p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/\psi p) $.
We report on the measurement of the $\gamma p \rightarrow J/\psi p$ cross section from $E_\gamma = 11.8$ GeV down to the threshold at $8.2$ GeV using a tagged photon beam with the GlueX experiment. ...We find the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section $d\sigma /dt$ has an exponential slope of $1.67 \pm 0.39$ GeV$^{-2}$ at $10.7$ GeV average energy. The LHCb pentaquark candidates $P_c^+$ can be produced in the $s$-channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions $\mathcal{B}(P_c^+ \rightarrow J/\psi p)$ and cross sections $\sigma(\gamma p \to P_c^+)\times\mathcal{B}(P_c^+ \to J/\psi p) $.
It has been suggested that autoimmune phenomena contribute to the depletion of CD4+ T cells and the development of AIDS in HIV-1 infected humans based, in part, on observations that some ...HIV-1-infected humans have autoantibodies reactive with Ag expressed on uninfected CD4+ cells. In this study, 11 of 14 asymptomatic HIV-1-infected homosexuals and hemophiliacs, but none of 17 uninfected homosexuals or heterosexuals, were found to have cytotoxic lymphocytes in blood that can lyse uninfected CD4+ T cells from humans and chimpanzees but not human B lymphoblastoid cells or mouse T cells. The cytotoxic PBL were concluded to be CTL rather than NK cells, with the phenotype being CD3+, TCR-1 alpha beta+, CD8+, CD4-, CD16- based on findings that PBL-mediated lysis of uninfected CD4+ cells was 1) blocked by a mAb to CD3, which inhibits CTL but not NK activity; 2) diminished by treatment of PBL with a mAb to CD8 and C, but not by treatment with mAb to CD4 or CD16 and C; and 3) blocked by mAb WT31 directed against the TCR-1 alpha beta. In contrast, PBL from HIV-1-infected chimpanzees, which to date have not developed AIDS, lacked detectable CTL lytic for uninfected CD4+ cells.
The aim of the study is to test whether nizatidine delivered via a unique bimodal pulsatile-controlled release system, nizatidine controlled release (CR), accelerates gastric emptying in patients ...with gastroesophageal reflux disease (GERD).
Combined data were analyzed on 39 patients with delayed gastric emptying (DGE) from 2 studies (n = 84) assessing the prokinetic effect of nizatidine CR. A single-blind placebo baseline was followed by double-blind nizatidine CR (150 and 300 mg) in randomized sequence, 2 to 5 days apart. Each dose was followed 1 hour later by an egg-beater meal, labeled with Tc99m. Gamma camera images were obtained at meal completion, 1-, 2-, 3- and 4-hour postmeal. All the 84 patients were classified at baseline with DGE (gastric retention >6.3% at 4 hours) or normal gastric emptying.
In the 39 patients identified with DGE, change from placebo baseline (CFB) for percent gastric retention at 4-hour postmeal with nizatidine CR (150 and 300 mg) was each improved and statistically significant (P < 0.05). In a subgroup of diabetic patients with DGE (n = 10), the CFB with nizatidine CR (300 mg) was significant (P < 0.05) at 3- and 4-hour postmeal.
Nizatidine CR (150 and 300 mg) significantly enhanced gastric emptying of a standard meal in patients with GERD with DGE.
In this work, we report on the measurement of the beam asymmetry $\Sigma$ for the reactions $\vec{\gamma}p\rightarrow p\eta$ and $\vec{\gamma}p \rightarrow p\eta^{\prime}$ from the GlueX experiment, ...using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Lab. These measurements are made as a function of momentum transfer $-t$, with significantly higher statistical precision than our earlier $\eta$ measurements, and are the first measurements of $\eta^{\prime}$ in this energy range. We compare the results to theoretical predictions based on $t$--channel quasi-particle exchange. Furthermore, we compare the ratio of $\Sigma_{\eta}$ to $\Sigma_{\eta^{\prime}}$ to these models, as this ratio is predicted to be sensitive to the amount of $s\bar{s}$ exchange in the production. We find that photoproduction of both $\eta$ and $\eta^{\prime}$ is dominated by natural parity exchange with little dependence on $-t$.
The incidence of cancer is increased in all gastrointestinal (GI) tissues as a result of chronic inflammation. These cancers may develop in cells that are selected for resistance to inflammatory ...products by virtue of overexpressing the antioxidant protein Bcl-2 or other Bcl-2 gene family members that have antioxidant activity. Unfortunately, Bcl-2 also functions as an anti-apoptotic. Bcl-2 overexpression can increase cellular lifetime and increase the likelihood that other cancer-related mutations will accumulate in individual cells. Thus, Bcl-2 expression is cytoprotective, but its expression also increases the risk of cancer incidence. This is perhaps more evident in the GI tract, which is exposed to more potential mutagens relative to other tissues.
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