CELLS MEDIATING SPECIFIC IN VITRO CYTOTOXICITY : I. DETECTION OF RECEPTOR-BEARING LYMPHOCYTES

Spleen cells from mice immunized with allogeneic tumor cells are incubated on different fibroblast monolayers. The nonadsorbed cells are tested for cytotoxicity against 51Cr-labeled target cells. The cytotoxicity of nonadsorbed cells is much lower after incubation on fibroblasts syngeneic to the immunizing tumor cells than after incubation on fibroblasts syngeneic to the immune cells. This specific decrease of cytotoxic activity depends on the duration and temperature of incubation on monolayers. After incubation the monolayers are trypsinized and pure populations of adsorbed lymphocytes isolated by density gradient fractionation. The cytotoxicity of such trypsin-eluted, gradient-purified lymphocytes is much higher when these lymphocytes are isolated from fibroblasts syngeneic to the immunizing tumor cells than when they are isolated from fibroblasts syngeneic to the immune cells. These experiments demonstrate specific adsorption of immune cells onto fibroblasts carrying the immunizing antigens, and thus prove the existence of specific receptors at the surface of these immune cells. Spleen cells from mice immunized with two types of allogeneic tumor cells bearing different H-2 antigen alleles are incubated on different fibroblast monolayers. The results of such experiments show a differential specific adsorption pattern, suggesting independent adsorption of two populations of immune cells bearing receptors directed against either one or the other immunizing H-2 antigen. The existence of at least a majority of cells, each of which is homogeneous as to the specificity of its receptors, makes it likely that specific receptors are synthetized by the cells that bear them. The role of specific receptor-bearing cells in the killing process is discussed

English-speaking Three-year-olds in a Spanish Language Immersion Program

Foreign language immersion programs, wherein the regular school curriculum is taught through the foreign language, have become increasingly widespread in recent years. Although there have been a plethora of studies reporting on second language immersion programs involving school-age programs, there is a dearth of information describing such programs for preschoolers. The purpose of this study was to observe and describe an immersion program for three-year-olds, particularly with respect to specific features of early stages of the language acquisition process. The primary area of interest was to determine the existence of and features of a silent period for these children. Secondary goals included analyzing the kinds of speech that emerged in the early stages of language acquisition, to whom it was directed, and the circumstances under which it was produced; discovering when and how the children manifest bilingual awareness; and ascertaining what strategies were used by them for comprehension. Using a qualitative case study approach, eight monolingual three-year-olds attending a Spanish-language immersion school were observed using participant observation methodology for a total of 98.35 hours between September 6, 1994 and March 17, 1995. Classroom observation was supplemented by questionnaires completed by the children\u27s parents, and by interviews of parents. The data generated revealed that although there is wide variation in the amount of speech produced by the children and when it was produced, there was no silent period for most children. These results are inconsistent with the literature which generally assumes that such a period exists. The study also revealed that although language mixing occurred, it appeared to be a function of language dominance and did not reflect mixing in the input. Children used a variety of strategies to make sense of the Spanish surrounding them, the most important of which was attending to context clues. Finally, all the children manifested bilingual awareness at the same time they began to produce Spanish utterances

Unitarity constraints on neutral pion electroproduction

At large virtuality $Q^2$, the coupling to the vector meson production channels provides us with a natural explanation of the surprisingly large cross section of the neutral pion electroproduction recently measured at Jefferson Laboratory, without destroying the good agreement between the Regge pole model and the data at the real photon point. Elastic rescattering of the $\pi^0$ provides us with a way to explain why the node, that appears at $t\sim -0.5$ GeV$^2$ at the real photon point, disappears as soon as $Q^2$ differs from zero.Comment: 7 pages; 12 figures Figures 1, 2, 10, 11, 12 updated. Axial-tensor coupling, instead of axial-vector coupling, at the b1NN verte

Effectiveness and tolerability of pegylated interferon alfa-2b in combination with ribavirin for treatment of chronic hepatitis C: the PegIntrust Study

Background and study aims : Large international clinical trials conducted in the past 5 years rapidly improved the treatment of chronic hepatitis C; however, it is unclear whether the advances seen in clinical trials are being paralleled by similar improvements in routine clinical practice. PegIntrust is a Belgian community-based trial evaluating the sustained virological response. Patients and Methods : Observational study of 219 patients receiving pegylated interferon alfa-2b (1.5 mu g/kg/wk) and weight. based ribavirin (800-1200 mg/day) for 48 weeks. Primary study end point was sustained virological response (SVR), defined as undetectable HCV RNA 6 months after the completion of treatment. Results : In total, 108 patients (49.3 %) had undetectable HCV RNA at the end of therapy, 91(41.6%) attaining SVR. Of the 111 patients without an end-of-treatment response, 28 were non-responders, and 21 had virological breakthrough. In total, 134 patients attained early virological response (EVR); 88 (65.7%) of those patients attained SVR. In contrast, 82 (96.5 %) of the 85 patients who did not attain EVR also did not attain SVR. Age, fibrosis score and baseline viral load were identified as important predictors of treatment outcome. The most frequently reported serious adverse events resulting in treatment discontinuation were anemia (n = 10), fatigue/asthenia/malaise (n = 6) and fever (n = 3). Conclusion : Our data indicate that treatment of chronic hepatitis C with PEG-IFN alfa-2b plus weight-based ribavirin results in favourable treatment outcomes in a Belgian cohort of patients treated in community-based clinical practice. (Ada gastroenterol. belg., 2010, 73, 5-11)

Pauli graphs, Riemann hypothesis, Goldbach pairs

Let consider the Pauli group $\mathcal{P}_q=$ with unitary quantum generators $X$ (shift) and $Z$ (clock) acting on the vectors of the $q$-dimensional Hilbert space via $X|s> =|s+1>$ and $Z|s> =\omega^s |s>$, with $\omega=\exp(2i\pi/q)$. It has been found that the number of maximal mutually commuting sets within $\mathcal{P}_q$ is controlled by the Dedekind psi function $\psi(q)=q \prod_{p|q}(1+\frac{1}{p})$ (with $p$ a prime) \cite{Planat2011} and that there exists a specific inequality $\frac{\psi (q)}{q}>e^{\gamma}\log \log q$, involving the Euler constant $\gamma \sim 0.577$, that is only satisfied at specific low dimensions $q \in \mathcal {A}=\{2,3,4,5,6,8,10,12,18,30\}$. The set $\mathcal{A}$ is closely related to the set $\mathcal{A} \cup \{1,24\}$ of integers that are totally Goldbach, i.e. that consist of all primes $p2$) is equivalent to Riemann hypothesis. Introducing the Hardy-Littlewood function $R(q)=2 C_2 \prod_{p|n}\frac{p-1}{p-2}$ (with $C_2 \sim 0.660$ the twin prime constant), that is used for estimating the number $g(q) \sim R(q) \frac{q}{\ln^2 q}$ of Goldbach pairs, one shows that the new inequality $\frac{R(N_r)}{\log \log N_r} \gtrapprox e^{\gamma}$ is also equivalent to Riemann hypothesis. In this paper, these number theoretical properties are discusssed in the context of the qudit commutation structure.Comment: 11 page