Citocinas e imunomodulação: novos avanços no tratamento das pancreatites

Inflammation is the principal feature of pancreatitis. Cytokines play a fundamental role in local and systemic inflammation, mediating tissue damage and orchestrating the ultimate results. This paper reviews the role of cytokines in acute and chronic pancreatitis, describing the different approaches of this subject and their methodological limitations. We also emphasize the new therapeutical modalities for pancreatitis, based in immunomodulation.As pancreatites se caracterizam por intenso processo inflamatório. A ativação de citocinas determina ou modula os principais mecanismos de lesão tissular local e à distância, participando dos danos que caracterizam as formas agudas ou crônicas de pancreatite. O trabalho faz uma revisão dos aspectos referentes à participação das citocinas na fisiopatologia das pancreatites, descrevendo de forma crítica as abordagens metodológicas que permitiram o seu estudo e apontando as novas modalidades de tratamento, com base na imunomodulação das citocinas

Center-to-Limb Variation of Solar Line Profiles as a Test of NLTE Line Formation Calculations

We present new observations of the center-to-limb variation of spectral lines in the quiet Sun. Our long-slit spectra are corrected for scattered light, which amounts to 4-8 % of the continuum intensity, by comparison with a Fourier transform spectrum of the disk center. We examine the effect of inelastic collisions with neutral hydrogen in NLTE line formation calculations of the oxygen infrared triplet, and the Na I 6160.8 A line. Adopting a classical one-dimensional theoretical model atmosphere, we find that the sodium transition, formed in higher layers, is much more effectively thermalized by hydrogen collisions than the high-excitation oxygen lines. This result appears as a simple consequence of the decrease of the ratio NH/Ne with depth in the solar photosphere. The center-to-limb variation of the selected lines is studied both under LTE and NLTE conditions. In the NLTE analysis, inelastic collisions with hydrogen atoms are considered with a simple approximation or neglected, in an attempt to test the validity of such approximation. For the sodium line studied, the best agreement between theory and observation happens when NLTE is considered and inelastic collisions with hydrogen are neglected in the rate equations. The analysis of the oxygen triplet benefits from a very detailed calculation using an LTE three-dimensional model atmosphere and NLTE line formation. The chi**2 statistics favors including hydrogen collisions with the approximation adopted, but the oxygen abundance derived in that case is significantly higher than the value derived from OH infrared transitions.Comment: 10 pages, 8 figures, to appear in A&

A pancreatite aguda na visão do imunologista

The acute pancreatitis is an inflammatory process of the pancreas, resulting from the action of enzymes activated inappropriately,causing swelling, bleeding and even pancreatic necrosis and peripancreática. The acinar cells in the pancreas and stellar cellspancreatic has been the study as participants in shaping the inflammatory process along with other inflammatory cells. Severalcytokines are released during pancreatitis, and thus, the local inflammatory process initially, may have an important systemicimpact, and the patient may present hypovolemia, involvement of multiple organs and systems and the possibility of death. Theclinical condition of pancreatitis as mild or severe depends on the length of the process and the complications that may arise.A pancreatite aguda é um processo inflamatório do pâncreas, decorrente da ação de enzimas inadequadamente ativadas,que causam edema, hemorragia e até necrose pancreática e peripancreática. As células acinares presentes no pâncreasassim como as células estelares pancreáticas tem sido alvo de estudo como participantes na formação do processoinflamatório juntamente com outras células inflamatórias. Diversas citocinas são liberadas durante a pancreatite, e assim,o processo inflamatório inicialmente local, pode ter uma repercussão sistêmica importante, e o paciente poderá apresentarhipovolemia, comprometimento de múltiplos órgãos e sistemas e possibilidade de óbito. A condição clinica da pancreatitena forma leve ou grave dependerá da extensão do processo e das complicações que podem advir

Green chemistry in analytical atomic spectrometry: a review

As a result of the greater consciousness within the analytical community on the impact of chemicals on human health and environment, green issues are increasingly taken into account when choosing an established analytical method or developing a new one. Apart from typical analytical characteristics (e.g., sensitivity, limit of detection, repeatability, etc.), other features such as the amount of sample/reagents, operation time, use of energy-effective apparatus, waste production, etc. should be highlighted in order to meet the principles of Green Chemistry. Although conventional approaches for trace element analysis by atomic spectrometry usually involve well-established sample pre-treatments based on ‘wet chemistry’, and high consumption of gases, reagents, etc. is inherent to many techniques in this group, there are still many avenues where green issues can be implemented. For greening atomic spectrometry, green chemistry principles should be applied to every step of the analytical process, i.e., from sampling and sample pre-treatment to data processing. In this review, main pathways for greening atomic spectrometry such as downsizing of instrumentation, use of portable instruments, solid sampling, application of clean energies (ultrasound, microwaves, etc.) for sample pre-treatment, development of on-site, on-line and at-line approaches vs. typical off-line methods, application of modern extraction techniques (e.g., solid- and liquid-phase microextraction), green solvents and derivatization agents and use of chemometric tools for method optimization, signal processing, etc. are discussed in a critical way.publishe