Oral tolerance to cancer can be abrogated by T regulatory cell inhibition

Oral administration of tumour cells induces an immune hypo-responsiveness known as oral tolerance. We have previously shown that oral tolerance to a cancer is tumour antigen specific, non-cross-reactive and confers a tumour growth advantage. We investigated the utilisation of regulatory T cell (Treg) depletion on oral tolerance to a cancer and its ability to control tumour growth. Balb/C mice were gavage fed homogenised tumour tissue – JBS fibrosarcoma (to induce oral tolerance to a cancer), or PBS as control. Growth of subcutaneous JBS tumours were measured; splenic tissue excised and flow cytometry used to quantify and compare systemic Tregs and T effector (Teff) cell populations. Prior to and/or following tumour feeding, mice were intraperitoneally administered anti-CD25, to inactivate systemic Tregs, or given isotype antibody as a control. Mice which were orally tolerised prior to subcutaneous tumour induction, displayed significantly higher systemic Treg levels (14% vs 6%) and faster tumour growth rates than controls (p<0.05). Complete regression of tumours were only seen after Treg inactivation and occurred in all groups - this was not inhibited by tumour feeding. The cure rates for Treg inactivation were 60% during tolerisation, 75% during tumour growth and 100% during inactivation for both tolerisation and tumour growth. Depletion of Tregs gave rise to an increased number of Teff cells. Treg depletion post-tolerisation and post-tumour induction led to the complete regression of all tumours on tumour bearing mice. Oral administration of tumour tissue, confers a tumour growth advantage and is accompanied by an increase in systemic Treg levels. The administration of anti-CD25 Ab decreased Treg numbers and caused an increase in Teffs. Most notably Treg cell inhibition overcame established oral tolerance with consequent tumor regression, especially relevant to foregut cancers where oral tolerance is likely to be induced by the shedding of tumour tissue into the gut

Experiência de um serviço de pediatria no apoio pós-operatório a correção da escoliose

info:eu-repo/semantics/publishedVersio

Descritores morfo agronômicos e fenológicos de linhagens de arroz (Oryza sativa L.) de várzeas e de terras altas.

O presente trabalho teve por objetivo apresentar os descritores morfo agronômicos e fenológicos de linhagens de arroz irrigado e de terras altas com possibilidades de serem recomendadas como novas cultivares comerciais.bitstream/CNPAF-2009-09/27599/1/doc_219.pd

On the construction of pseudo-hermitian quantum system with a pre-determined metric in the Hilbert space

A class of pseudo-hermitian quantum system with an explicit form of the positive-definite metric in the Hilbert space is presented. The general method involves a realization of the basic canonical commutation relations defining the quantum system in terms of operators those are hermitian with respect to a pre-determined positive definite metric in the Hilbert space. Appropriate combinations of these operators result in a large number of pseudo-hermitian quantum systems admitting entirely real spectra and unitary time evolution. The examples considered include simple harmonic oscillators with complex angular frequencies, Stark(Zeeman) effect with complex electric(magnetic) field, non-hermitian general quadratic form of N boson(fermion) operators, symmetric and asymmetric XXZ spin-chain in complex magnetic field, non-hermitian Haldane-Shastry spin-chain and Lipkin-Meshkov-Glick model.Comment: 29 pages, revtex, minor changes, version to appear in Journal of Physics A(v3

Ionisation and dissociation of cometary gaseous organic molecules by solar wind particles I: Formic Acid

In order to simulate the effects of energetic charged particles present in the solar wind colliding with the cometary gaseous formic acid molecule (HCOOH), laboratory experiments have been performed. The absolute ionisation and dissociation cross sections for this molecule interacting with solar wind particles were measured employing fast electrons in the energy range of 0.5 to 2 keV and energetic protons with energies varying from 0.128 to 2 MeV. Despite the fact that both projectiles lead to a very similar fragmentation pattern, differences in the relative intensities of the fragments were observed. Formic acid survives about 4-5 times more to the proton beam than to the energetic electron collision.The minimum momentum transfer in the electron impact case was estimated to be 3-38% larger than the minimum momentum transfer observed with the equivelocity protons. The UV photodissociation rates and half-lives for HCOOH are roughly closer to the values obtained with energetic electrons. It is consequently important to take electron impact data into account when developing chemical models to simulate the interplanetary conditions.Comment: 11 pages, 7 figures, 5 tables, Accepted to be published in MNRA

Imunoterapia Ativa Específica e imunoquimioterapia Adotiva em Tumores Experimentais. Ação da “interleukin-2”

Uma preparação de proteínas de membrana plasmática de células tumorais obtida por processo original de vesiculação de membrana celular é usada como antígeno especifico do tumor. Em sistema singênico protegeu 80% dos camundongos contra inóculo tumoral. Inóculo tumoral já estabelecido, em início de crescimento, é curado em 70 a 80% com inoculação de antigeno de membrana com adjuvante, em tumores experimentais de camundongo: A imunoterapia adotiva específica, isto é, a transferência de linfócitos pré-sensibilizados, não protegeu camundongos contra tumor já desenvolvido. A imunoquimioterapia adotiva, transferência de linfócitos de baço de animal Imunizados pelo tumor + 1 dose de ciclofosfamida foi eficiente, curando 80% dos animais com tumor singênico já estabelecido, sendo que a cidofosfamida apenas retarda temporariamente o crescimento tumoral. Este projeto não tem aplicação clínica, pois para o doente não se dispõe de linfócitos isogênicos sensibilizados especificamente contra seu câncer. Está sendo tentada a substituição de linfócitos T sensibilizados por "lnterleukin-2" + cidofosfamida. A "lnterleukin-2" é obtida in vitro por ação de macrófago + Hnfódto T helper + concanavalina A. Experiências preliminares em tumores experimentais deram nítido retardamento do crescimento dos mesmos. Este produto está sendo purificado e concentrado e produzido especificamente com antígeno do próprio tumor

Event by event analysis of collision induced cluster ion fragmentation: sequential monomer evaporation versus fission reactions

IP