506 research outputs found

    Lesão expansiva cerebral devida a citomegalovírus: relato de caso e revisão da literatura

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    Cytomegalovirus (CMV) disease in acquired immunodeficiency syndrome (AIDS) patients most commonly presents as chorioretinitis and gastro-intestinal infection. Neurological involvement due to CMV may cause several clinical presentations: polyradiculitis, myelitis, encephalitis, ventriculo-encephalitis, and mononeuritis multiplex. Rarely, cerebral mass lesion is described. We report a 39 year-old woman with AIDS and previous cerebral toxoplasmosis. She presented with fever, seizures, and vulval ulcers. Her chest X-ray showed multiple lung nodules, and a large frontal lobe lesion was seen in a brain computed tomography scan. She underwent a brain biopsy through a frontal craniotomy, but her condition deteriorated and she died in the first postoperative day. Histopathological studies and immunohistochemistry disclosed CMV disease, and there was no evidence of cerebral toxoplasmosis, bacterial, mycobacterial or fungal infection. CMV disease should be considered in the differential diagnosis of cerebral mass lesion in AIDS patients. High suspicion index, timely diagnostic procedures (surgical or minimally invasive), and proper utilization of prophylactic and therapeutic medication could improve outcome of these patients.As doenças causadas pelo citomegalovírus (CMV) em pacientes com a síndrome da imunodeficiência adquirida apresentam-se principalmente como corioretinite ou comprometimento gastrointestinal. No sistema nervoso central, o CMV pode causar diversas síndromes clínicas: poliradiculite, mielite, encefalite, ventrículo-encefalite e mononeurite múltipla. Raramente, lesões expansivas cerebrais são descritas. Os autores relatam o caso de uma paciente de 39 anos com antecedentes de infecção pelo HIV e toxoplasmose cerebral, que apresentou-se com febre, convulsões e úlceras vulvares. O raios-X de tórax demonstrou múltiplos nódulos pulmonares e a tomografia computadorizada de crânio evidenciou extensa lesão no lobo frontal esquerdo. Após ser submetida à craniotomia, evoluiu com piora clínica, falecendo no primeiro dia de pós-operatório. Os estudos histopatológicos e imunohistoquímicos demonstraram doença citomegálica. Foram excluídas toxoplasmose cerebral e infecção bacteriana, micobacteriana ou fúngica. Concluímos que, embora seja extremamente raro, o CMV deve ser considerado no diagnóstico diferencial das lesões expansivas cerebrais em pacientes com infecção pelo HIV. Um elevado índice de suspeita, procedimentos diagnósticos oportunos (cirúrgicos ou minimamente invasivos), e o adequado uso de antivirais (terapêuticos e profiláticos) podem melhorar o prognóstico desta letal manifestação

    Magnetocaloric Effect And Evidence Of Superparamagnetism In Gda L2 Nanocrystallites: A Magnetic-structural Correlation

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    The correlation between structural and magnetic properties of GdAl2, focusing on the role played by the disorder in magnetic ordering and how it influences the magnetocaloric effect (MCE) are discussed. Micrometric-sized particles, consisting of nanocrystallites embedded in an amorphous matrix, were prepared by a mechanical milling technique and characterized by means of x-ray diffraction, scanning and high-resolution transmission electron microscopy as well as magnetic measurements as a function of an applied external magnetic field and temperature. The results show that the average particle size is just slightly diminished (≈7%) with the milling time (between 3 and 13 h), whereas the average crystallite size undergoes an expressive reduction (≈43%). For long milling times, structural disorders mostly associated with crystallite size singularly affect the magnetic properties, leading to a large tablelike MCE in the temperature range between 30 and 165 K. Below 30 K, nanocrystallites with dimensions below a given critical size cause an enhancement in the magnetic entropy change related to superparamagnetic behavior. In contrast, for low milling times, relative cooling power values are improved. These striking features along with the small magnetic hysteresis observed make the milled GdAl2 a promising material for application in the magnetic refrigeration technology. Finally, a discussion in an attempt to elucidate the origin of the spin-glass states previously reported in the literature for mechanically milled GdAl2 samples for very long times (400 and 1000 h) is presented. © 2016 American Physical Society.93

    Abscesso tuberculoso cerebral em paciente com AIDS: relato de caso e revisão da literatura

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    Tuberculous brain abscesses in AIDS patients are considered rare with only eight cases reported in the literature. We describe the case of a 34-year-old woman with AIDS and previous toxoplasmic encephalitis who was admitted due to headache and seizures. A brain computed tomography scan disclosed a frontal hypodense lesion with a contrast ring enhancement. Brain abscess was suspected and she underwent a lesion puncture through a trepanation. The material extracted was purulent and the acid-fast smear was markedly positive. Timely medical and surgical approaches allowed a good outcome. Tuberculous abscesses should be considered in the differential diagnosis of focal brain lesions in AIDS patients. Surgical excision or stereotactic aspiration, and antituberculous treatment are the mainstay in the management of these uncommon lesions.Os abscessos tuberculosos cerebrais em pacientes com aids são raros, existindo apenas 8 casos publicados. Os autores relatam o caso de uma paciente de 34 anos com aids e antecedente de toxoplasmose cerebral, que foi admitida por cefaléia e convulsões. A tomografia computadorizada de crânio evidenciou lesão frontal única, grande, com realce anular e efeito expansivo. Diante da suspeita de abscesso cerebral foi submetida a trepanação, drenando material purulento e demonstrando presença de abundantes bacilos ácido-álcool resistentes. Abordagem cirúrgica e clínica oportuna determinaram uma boa evolução. Os abscessos tuberculosos devem ser considerados no diagnóstico diferencial das massas intracranianas em pacientes com aids. Excisão cirúrgica ou aspiração por estereotaxia e tuberculostáticos constituem as bases do tratamento destas lesões incomuns

    Phase transitions for suspension flows

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    This paper is devoted to study thermodynamic formalism for suspension flows defined over countable alphabets. We are mostly interested in the regularity properties of the pressure function. We establish conditions for the pressure function to be real analytic or to exhibit a phase transition. We also construct an example of a potential for which the pressure has countably many phase transitions.Comment: Example 5.2 expanded. Typos corrected. Section 6.1 superced the note "Thermodynamic formalism for the positive geodesic flow on the modular surface" arXiv:1009.462

    Aspergilosis cerebral causada por Aspergillus fumigatus en paciente con SIDA: primer reporte de caso demostrado por cultivo en Brasil

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    Cerebral aspergillosis is a rare cause of brain expansive lesion in AIDS patients. We report the first culture-proven case of brain abscess due to Aspergillus fumigatus in a Brazilian AIDS patient. The patient, a 26 year-old male with human immunodeficiency virus (HIV) infection and history of pulmonary tuberculosis and cerebral toxoplasmosis, had fever, cough, dyspnea, and two episodes of seizures. The brain computerized tomography (CT) showed a bi-parietal and parasagittal hypodense lesion with peripheral enhancement, and significant mass effect. There was started anti-Toxoplasma treatment. Three weeks later, the patient presented mental confusion, and a new brain CT evidenced increase in the lesion. He underwent brain biopsy, draining 10 mL of purulent material. The direct mycological examination revealed septated and hyaline hyphae. There was started amphotericin B deoxycholate. The culture of the material demonstrated presence of the Aspergillus fumigatus. The following two months, the patient was submitted to three surgeries, with insertion of drainage catheter and administration of amphotericin B intralesional. Three months after hospital admission, his neurological condition suffered discrete changes. However, he died due to intrahospital pneumonia. Brain abscess caused by Aspergillus fumigatus must be considered in the differential diagnosis of the brain expansive lesions in AIDS patients in Brazil.La aspergilosis cerebral es una causa rara de lesión expansiva cerebral en pacientes con SIDA. Presentamos el primer reporte de un absceso cerebral causado por Aspergillus fumigatus en un paciente brasileño con SIDA. El paciente, de 26 años de edad, presentaba antecedentes de infección por el virus de la inmunodeficiencia humana (VIH), tuberculosis pulmonar y toxoplasmosis cerebral. Manifestó fiebre, tos, disnea y dos episódios de convulsiones. La tomografía computadorizada (TC) demostró una lesión hipodensa parasagital y bi-parietal con realce periférico e importante efecto de masa. Se inició tratamiento anti-Toxoplasma. Tres semanas después, el paciente evidenció confusión mental y una nueva TC de cráneo mostró aumento de la lesión. Se realizó biopsia cerebral con drenaje de 10 mL de material purulento. El examen micológico directo reveló hifas hialinas septadas. Se inició anfotericina B deoxicolato. La cultura del material demostró presencia de Aspergillus fumigatus. En los siguientes dos meses el paciente fue sometido a otras tres cirugías, insertándose un catéter de drenaje y administrándose anfotericina B intralesional. Tres meses después de la admisión hospitalaria, la condición neurológica del paciente sufrió discretos cambios. Sin embargo, falleció debido a neumonia intrahospitalaria. Aunque muy raros, los abscesos cerebrales causados por Aspergillus fumigatus deben ser considerados en el diagnóstico diferencial de las lesiones expansivas cerebrales en pacientes con SIDA

    Semaphorin 3F signaling actively retains neutrophils at sites of inflammation

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    Neutrophilic inflammation is central to disease pathogenesis, for example, in chronic obstructive pulmonary disease, yet the mechanisms that retain neutrophils within tissues remain poorly understood. With emerging evidence that axon guidance factors can regulate myeloid recruitment and that neutrophils can regulate expression of a class 3 semaphorin, SEMA3F, we investigated the role of SEMA3F in inflammatory cell retention within inflamed tissues. We observed that neutrophils upregulate SEMA3F in response to proinflammatory mediators and following neutrophil recruitment to the inflamed lung. In both zebrafish tail injury and murine acute lung injury models of neutrophilic inflammation, overexpression of SEMA3F delayed inflammation resolution with slower neutrophil migratory speeds and retention of neutrophils within the tissues. Conversely, constitutive loss of sema3f accelerated egress of neutrophils from the tail injury site in fish, whereas neutrophil-specific deletion of Sema3f in mice resulted in more rapid neutrophil transit through the airways, and significantly reduced time to resolution of the neutrophilic response. Study of filamentous-actin (F-actin) subsequently showed that SEMA3F-mediated retention is associated with F-actin disassembly. In conclusion, SEMA3F signaling actively regulates neutrophil retention within the injured tissues with consequences for neutrophil clearance and inflammation resolution

    Effect of partial soil wetting on transpiration, vegetative growth and root system of young orange trees

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    The wetted area fraction is a factor critical to the success of drip irrigation. This study aimed to evaluate the effect of partial soil wetting on transpiration, vegetative growth and root system of young orange trees. The experiment was carried out in a greenhouse where plants were grown in 0.5 m3boxes internally divided into compartments. The wetting of 12 % of soil area was tested on two types of soil cultivated with ‘Valencia’ orange trees grafted onto Rangpur lime and ‘Swingle’ citrumelo rootstocks. Transpiration was determined in 40 plants. Water extraction and root density were evaluated in the compartments. Transpiration is reduced by restriction in wetted soil area, and such reduction is influenced by the number of days after the beginning of partial irrigation, atmospheric evaporative demand and plant phenological stage. Mean transpiration of plants with partial irrigation was equivalent to 84 % of the mean transpiration of plants with 100 % of wetted soil area in the period studied. However, after 156 days of imposing partial irrigation there was no difference in transpiration between treatments. Plant acclimation was caused by an increase in root concentration in the irrigated area. After a period of acclimation, if the entire root system is wetted, soil water extraction becomes proportional to the percentage of wetted area after a short period of time. Despite the reduction in transpiration, there was no difference between treatments with 12 % and 100 % of wetted soil area in terms of vegetative growth
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