Efeito do lítio sobre a hiperatividade locomotora induzida pela lesão eletrolítica da região do núcleo mediano da rafe em ratos

A lesão do núcleo mediano da rafe (NMR) produz sintomas que sugerem validade de face ao episódio maníaco. Esta pesquisa avaliou o efeito do lítio sobre a hiperatividade locomotora induzida por esta lesão. Vinte e um ratos Wistar machos foram submetidos à lesão eletrolítica da região do NMR (LR) e 17 foram submetidos à lesão fictícia (LF). Após recuperação, a atividade locomotora foi avaliada na caixa de atividade (Med Associates/ENV-515). Parte dos animais destes grupos recebeu tratamentos com lítio (47,5 mg/kg/2x dia i.p.) por 10 dias, enquanto o restante foi tratado com salina no mesmo esquema. A reavaliação ao final dos tratamentos demonstrou que o lítio reduziu significantemente a atividade locomotora em relação à avaliação inicial no grupo LR (ANOVA/Bonferroni p < 0,05), tornando-a equivalente aos baixos níveis dos grupos LF. Estes dados sustentam a hipótese de que as manifestações induzidas pela lesão do NMR podem constituir um modelo animal de mania.

Rat subcutaneous tissue response to MTA Fillapex® and Portland cement

The aim of this study was to evaluate the response of rat subcutaneous tissue to MTA Fillapex® (Angelus), an experimental root canal filling material based on Portland cement and propylene glycol (PCPG), and a zinc oxide, eugenol and iodoform (ZOEI) paste. These materials were placed in polyethylene tubes and implanted into the dorsal connective tissue of Wistar rats for 7 and 15 days. The specimens were stained with hematoxylin and eosin, and evaluated regarding inflammatory reaction parameters by optical microscopy. The intensity of inflammatory response against the sealers was analyzed by two blinded and previously calibrated examiners for all experimental periods (kappa=0.96). The histological evaluation showed that all materials caused a moderate inflammatory reaction at 7 days, which subsided with time. A greater inflammatory reaction was observed at 7 days in the tubes filled with ZOEI paste. Tubes filled with MTA Fillapex presented some giant cells, macrophages and lymphocytes after 7 days. At 15 days, the presence of fibroblasts and collagen fibers was observed indicating normal tissue healing. The tubes filled with PCPG showed similar results to those observed in MTA Fillapex. At 15 days, the inflammatory reaction was almost absent at the tissue, with several collagen fibers indicating normal tissue healing. Data were analyzed by the nonparametric Kruskal-Wallis test (?=0.05). Statistically significant difference (p<0.05) was found only between PCPG at 15 days and ZOEI at 7 days groups. No significant differences were observed among the other groups/periods (p>0.05). MTA Fillapex and Portland cement added with propylene glycol had greater tissue compatibility than the PCPG paste.

Intralesional corticosteroid injections in the treatment of central giant cell lesions of the jaws

Objective: The aim of this study was to evaluate the response of treatment of central giant cell lesion to intralesional corticosteroid injections. Study Design: Review of articles indexed in PubMed on the topic between the years 1988 and 2011, and development of a descriptive meta-analysis of the results. Results: Sample of 41 patients primarily treated with intralesional corticosteroid injections was obtained, with a male female ratio of 1:0.95, being 23 aggressive and 18 non-aggressive central giant cell lesions. Triamcinolone acetonide and triamcinolone hexacetonide were the drugs used, and 78.0% cases were considered as good result, 14.6% were considered as moderate response and 7.3% were considered as negative result to treatment. Considering the aggressiveness, 88.9% of non-aggressive lesions presented a good response to treatment, in aggressive central giant cell lesions, 69.6% presented a good response to intralesional corticosteroid injections. Conclusion: In view of the results analyzed, intralesional corticosteroid injections could be considered as first treatment option for central giant cell lesion.

Central giant cell granuloma

Background: Central giant cell granuloma is a benign condition of the jaws which may present an aggressive behavior. Case report: A 9-year-old boy was complaining of swelling in the floor of the mouth. A solid swelling was observed in the area of the lower incisors. From the radiographic exam, we observed a radiolucent image in the mandibular bone with well-defined limits extending from the apical region of tooth 33 to the apical region of tooth 42. Discussion: Due to the diagnosis and the age of the patient, we chose a conservative treatment, administering subcutaneous injections of calcitonin. During this treatment, no reduction to the lesion was observed. Therefore, we chose to treat the lesion with triamcinolone acetonide. Monthly follow-ups demonstrated good lesion reduction and the absence of any clinical symptoms during the first 2 years. After a 3-year follow-up, the patient returned, presenting mobility of the lower incisors. A significant increase in the size of the lesion was observed. After a biopsy, with the removal of tissuewhich had the appearance of a cyst capsule, microscopic analyses were found to be compatible with a secondarily infected cyst. Two months following this procedure, the patient did not present tooth mobility anymore and the oral mucosa presented a normal aspect. Following a radiographic exam, full lesion repair was observed. These conservative treatments should be the first option in cases of central giant cell granuloma and the patient must be observed for a long period of time, until no further clinical or radiographic signs of lesions are observed

Remodelamento miocárdico após grandes infartos converte potenciação pós-pausa em decaimento da força em ratos

FUNDAMENTO: A Contração Pós-Repouso (CPR) do músculo cardíaco fornece informações indiretas sobre a manipulação de cálcio intracelular. OBJETIVO: Nosso objetivo foi estudar o comportamento da CPR e seus mecanismos subjacentes em camundongos com infarto do miocárdio. MÉTODOS: Seis semanas após a oclusão coronariana, a contratilidade dos Músculos Papilares (MP) obtidos a partir de camundongos submetidos à cirurgia sham (C, n = 17), com infarto moderado (MMI, n = 10) e grande infarto (LMI, n = 14), foi avaliada após intervalos de repouso de 10 a 60 segundos antes e depois da incubação com cloreto de lítio (Li+) em substituição ao cloreto de sódio ou rianodina (Ry). A expressão proteica de SR Ca(2+)-ATPase (SERCA2), trocador Na+/Ca2+ (NCX), fosfolambam (PLB) e fosfo-Ser (16)-PLB foi analisada por Western blotting. RESULTADOS: Os camundongos MMI apresentaram potenciação de CPR reduzida em comparação aos camundongos C. Em oposição à potenciação normal para camundongos C, foram observadas degradações de força pós-repouso nos músculos de camundongos LMI. Além disso, a Ry bloqueou a degradação ou potenciação de PRC observada em camundongos LMI e C; o Li+ inibiu o NCX e converteu a degradação em potenciação de CPR em camundongos LMI. Embora os camundongos MMI e LMI tenham apresentado diminuição no SERCA2 (72 ± 7% e 47 ± 9% de camundongos controle, respectivamente) e expressão protéica de fosfo-Ser16-PLB (75 ± 5% e 46 ± 11%, respectivamente), a superexpressão do NCX (175 ± 20%) só foi observada nos músculos de camundongos LMI. CONCLUSÃO: Nossos resultados mostraram, pela primeira vez, que a remodelação miocárdica pós-IAM em camundongos pode mudar a potenciação regular para degradação pós-repouso, afetando as proteínas de manipulação de Ca(2+) em miócitos.

Análise da rejeição do transplante de aponeurose em coelhos

OBJETIVO: Estudar a viabilidade de aponeurose heteróloga para fechar parede abdominal de coelhos, com ênfase no processo de rejeição. MÉTODOS: Este projeto foi aprovado pelo Comitê de Cuidados Animais da Faculdade de Ciências Médicas da Santa Casa de São Paulo e realizado na Unidade Técnica e Cirurgia Experimental. Quatro coelhas vermelhas trocaram aponeurose da parede abdominal com outros quatro animais machos brancos. Em dois coelhos, foi retirada e substituída a aponeurose como controle do processo cicatricial. Eles foram avaliados 1 vez por dia e sacrificados após 7 dias. Foi realizada a imunoistoquímica com CD20 e CD79. RESULTADOS: Os animais não tiveram celulite, abscesso, hematoma, deiscência da ferida ou hérnia. O local do enxerto mostrou hiperemia intensa. A análise histológica mostrou um processo inflamatório, com a presença de miofibroblastos em amadurecimento e colágeno, que variou de incipiente a moderado. O número de vasos estava reduzido e as células inflamatórias foram, em sua maioria, células plasmáticas e macrófagos. Não havia sinais morfológicos da rejeição aguda com a agressão do endotélio vascular. O músculo adjacente mostrou sinais de degeneração, com reação inflamatória dos núcleos e condensação do citoplasma. A análise imunoistoquímica (CD20 e CD79) mostrou que o processo inflamatório não foi mediado por linfócitos. O teste não paramétrico de Mann-Whitney mostrou que não se pode rejeitar a hipótese de igualdade (p>0,05). CONCLUSÃO: Não houve complicações pós-operatórias (fístulas, deiscência etc.) e a análise histológica revelou processo inflamatório inespecífico. A análise imunoistoquímica mostrou que o processo inflamatório não foi em razão de uma possível rejeição.

Time lags of the kilohertz quasi-periodic oscillations in the low-mass X-ray binaries 4U 1608−52 and 4U 1636−53

We studied the energy and frequency dependence of the Fourier time lags and intrinsic coherence of the kilohertz quasi-periodic oscillations (kHz QPOs) in the neutron-star lowmass X-ray binaries 4U 1608−52 and 4U 1636−53, using a large data set obtained with the Rossi X-ray Timing Explorer. We confirmed that, in both sources, the time lags of the lower kHz QPO are soft and their magnitude increases with energy. We also found that: (i) In 4U 1636−53, the soft lags of the lower kHz QPO remain constant at∼30 μs in the QPO frequency range 500–850 Hz, and decrease to ∼10 μs when the QPO frequency increases further. In 4U 1608−52, the soft lags of the lower kHz QPO remain constant at 40 μs up to 800 Hz, the highest frequency reached by this QPO in our data. (ii) In both sources, the time lags of the upper kHz QPO are hard, independent of energy or frequency and inconsistent with the soft lags of the lower kHz QPO. (iii) In both sources the intrinsic coherence of the lower kHz QPO remains constant at ∼0.6 between 5 and 12 keV, and drops to zero above that energy. The intrinsic coherence of the upper kHz QPO is consistent with being zero across the full energy range. (iv) In 4U 1636−53, the intrinsic coherence of the lower kHz QPO increases from ∼0 at ∼600 Hz to ∼1, and it decreases to ∼0.5 at 920 Hz; in 4U 1608−52, the intrinsic coherence is consistent with the same trend. (v) In both sources the intrinsic coherence of the upper kHz QPO is consistent with zero over the full frequency range of the QPO, except in 4U 1636−53 between 700 and 900 Hz where the intrinsic coherence marginally increases. We discuss our results in the context of scenarios in which the soft lags are either due to reflection off the accretion disc or up-/down-scattering in a hot medium close to the neutron star. We finally explore the connection between, on one hand the time lags and the intrinsic coherence of the kHz QPOs, and on the other the QPOs’ amplitude and quality factor in these two sources.

Variable rotational line broadening in the Be star Achernar

Aims. The main theoretical problem for the formation of a Keplerian disk around Be stars is how angular momentum is supplied from the star to the disk, even more so since Be stars probably rotate somewhat subcritically. For instance, nonradial pulsation may transport angular momentum to the stellar surface until (part of) this excess supports the disk-formation/replenishment. The nearby Be star Achernar is presently building a new disk and o ers an excellent opportunity to observe this process from relatively close-up. Methods. Spectra from various sources and epochs are scrutinized to identify the salient stellar parameters characterizing the disk life cycle as defined by H emission. The variable strength of the non-radial pulsation is confirmed, but does not a ect the other results. Results. For the first time it is demonstrated that the photospheric line width does vary in a Be star, by as much as v sin i . 35 km However, unlike assumptions in which a photospheric spin-up accumulates during the diskless phase and then is released into the disk as it is fed, the apparent photospheric spin-up is positively correlated with the appearance of H line emission. The photospheric line widths and circumstellar emission increase together, and the apparent stellar rotation declines to the value at quiescence after the H line emission becomes undetectable

Magnetic color-flavor-locked stars

Using the solutions of the gap equations of the magnetic-color-flavor-locked (MCFL) phase of paired quark matter in a magnetic field, and taking into consideration the separation between the longitudinal and transverse pressures due to the field-induced breaking of the spatial rotational symmetry, the equation of state (EoS) of the MCFL phase is self-consistently determined. Implications for stellar models of magnetized (self-bound) strange stars and hybrid (MCFL core) stars are discussed.

Stability and dynamics of terrestrial planets in binary star systems: application on Alpha Centauri

Binary stars are frequent in the universe, with about 50% of the known main sequence stars being located at a multiple star system (Abt, 1979). Even though, they are universally thought as second rate sites for the location of exo-planets and the habitable zone, due to the difficulties of detection and high perturbation that could prevent planet formation and long term stability. In this work we show that planets in binary star systems can have regular orbits and remain on the habitable zone. We introduce a stability criterium based on the solution of the restricted three body problem and apply it to describe the short period planar and three-dimentional stability zones of S-type orbits around each star of the Alpha Centauri system. We develop as well a semi-analytical secular model to study the long term dynamics of fictional planets in the habitable zone of those stars and we verify that planets on the habitable zone would be in regular orbits with any eccentricity and with inclination to the binary orbital plane up until 35 degrees. We show as well that the short period oscillations on the semi-major axis is 100 times greater than the Earth's, but at all the time the planet would still be found inside the Habitable zone.

Kinematic distances of pre-main-sequence stars in the Lupus star-forming region

To reliably determine the main physical parameters (masses and ages) of young stars, we must know their distances. While the average distance to nearby star-forming regions (<300 pc) is often known, the distances to individual stars are usually unknown. Individual distances to members of young moving groups can be derived from their radial velocities and proper motions using the convergent-point strategy. We investigate the kinematic properties of the Lupus moving group with the primary objective of deriving individual distances to all group members.

Observational effects of stellar rotation on Be stars' disks

Be stars are known to be fast rotators. At high rotation rates a profound modification of the radiation field reaching the circumstellar environment is expected. The origin of this modification is the decrease of the effective gravity on stellar surface leading to the stellar geometrical flattening and the gravity darkening effect predicted by Von Zeipel. Making use of the radiative transfer code HDUST we discuss the consequences of such stellar rotation on the structure of Be star disks based on the Viscous Decretion Disk model. Observational predictions are also made, as SED, IR-excess and Hydrogen line profiles. The modified illumination of the circumstellar disk generates significant changes in these quantities. Ascertaining these changes is useful to set some of the fundamental parameters of the Be system and to unveil the role of stellar rotation over the stellar evolution.

A galaxy model from Two Micron All Sky Survey star counts in the whole sky, including the plane

We use the star count model of Ortiz & Lépine to perform an unprecedented exploration of the most important Galactic parameters comparing the predicted counts with the Two Micron All Sky Survey observed star counts in the J, H, and KS bands for a grid of positions covering the whole sky. The comparison is made using a grid of lines of sight given by the HEALPix pixelization scheme. The resulting best-fit values for the parameters are: 2120 ± 200 pc for the radial scale length and 205 ± 40 pc for the scale height of the thin disk, with a central hole of 2070$_{-800}^{+2000}$ pc for the same disk, 3050 ± 500 pc for the radial scale length and 640 ± 70 pc for the scale height of the thick disk, 400 ± 100 pc for the central dimension of the spheroid, 0.0082 ± 0.0030 for the spheroid to disk density ratio, and 0.57 ± 0.05 for the oblate spheroid parameter.

The Gemini planet-finding campaign: the frequency of giant planets aroud debris disk stars

We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.''5 and 14.1 mag at 1'' separation. Follow-up observations of the 66 candidates with projected separation <500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known β Pictoris and the HR 8799 planets. Our results show at 95% confidence that <13% of debris disk stars have a ≥5 M Jup planet beyond 80 AU, and <21% of debris disk stars have a ≥3 M Jup planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly imaged planets as d 2 N/dMdavpropm α a β, where m is planet mass and a is orbital semi-major axis (with a maximum value of a max). We find that β < –0.8 and/or α > 1.7. Likewise, we find that β < –0.8 and/or a max < 200 AU. For the case where the planet frequency rises sharply with mass (α > 1.7), this occurs because all the planets detected to date have masses above 5 M Jup, but planets of lower mass could easily have been detected by our search. If we ignore the β Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that <20% of debris disk stars have a ≥3 M Jup planet beyond 10 AU, and β < –0.8 and/or α < –1.5. Likewise, β < –0.8 and/or a max < 125 AU. Our Bayesian constraints are not strong enough to reveal any dependence of the planet frequency on stellar host mass. Studies of transition disks have suggested that about 20% of stars are undergoing planet formation; our non-detections at large separations show that planets with orbital separation >40 AU and planet masses >3 M Jup do not carve the central holes in these disks.