A numerical study on the interplay between the intra-particle and interparticle characteristics in bimagnetic soft/soft and hard/soft ultrasmall nanoparticle assemblies.

A mesoscopic scale approach and the Monte Carlo (MC) method have been employed to study the exchange bias behaviour of MnFe2O4 (soft)/maghemite (soft) and CoFe2O4 (hard)/maghemite (soft) nanoparticles (NPs) of size ∼ 3 nm in dense and diluted assemblies at low temperatures. The analysis of our MC results clearly shows that in the powder samples the contribution to the exchange bias field (H ex) and the coercivity (H c) comes mainly from the intraparticle core/shell structure in the hard/soft sample and that the interplay between the internal characteristics and the interparticle interactions is more important in the soft/soft samples where the dipolar strength is enhanced. In the diluted frozen ferrofluid samples where interparticle exchange interactions are absent and the role of the dipolar interactions is not significant the exchange bias effects are reduced, and they come from the intra particle structure. The variation of H ex and H c with the applied cooling field well reproduces the experimental findings and sheds light on the key mechanisms of the observed magnetic behaviour. Our results demonstrate the possibility to control the magnetic behaviour of nanostructures by using properly chosen core/shell bimagnetic nanoparticles.

Core-Shell Bimagnetic Nanoadsorbents for Hexavalent Chromium Removal from Aqueous Solutions.

Novel nanoadsorbents based on core-shell bimagnetic nanoparticles (CoFe2O4@É£-Fe2O3) with two different mean sizes were elaborated, characterized and applied as potential sorbents for Cr(VI) removal from aqueous solutions through magnetically assisted chemical separation. The nanoadsorbents were characterized by XRD, TEM, FTIR, XPS, potentiometric-conductometric titrations, BET and vibrating sample magnetometry. The influence of contact time, shaking rate, pH, pollutant concentration, temperature and competing ions on Cr(VI) adsorption were evaluated. The results were analyzed in the framework of Langmuir and Freundlich models to evaluate the maximum adsorption capacity and the extent of affinity. The nanoadsorbents showed a good selectivity for Cr(VI) adsorption and were more effective at pH = 2.5, with a shaking rate of 400 RPM. The adsorption process was spontaneous, endothermic and presented an increased randomness. The contact time required to reach the equilibrium was relatively short and the kinetic date followed the pseudo-second-order model. The maximum adsorption capacity was nearly 40% higher for the nanoadsorbent of smaller mean size due to its higher surface area. Regeneration studies revealed that the nanoadsorbents can be recovered for reuse. These results indicate that prepared nanoadsorbents can be used as a powerful tool for Cr(VI) removal from contaminated water.

Severe multi-resistant pemphigus vulgaris: prolonged remission with a single cycle of rituximab.

Pemphigus vulgaris is an autoimmune bullous disease whose therapy is based on systemic corticosteroids, with or without immunosuppressants. Rituximab is a chimeric monoclonal antibody of the IgG class, directed at a specific CD20 B cell surface antigen, used in pemphigus vulgaris empirically since 2002, with success in 90% of the cases and long periods of remission. Male patient, 33 years old, diagnosed with pemphigus vulgaris, confirmed by histopathology and direct immunofluorescence. He was treated for seven months with numerous treatments, including immunosuppressive drugs, with an unsatisfactory response, until he had complete remission with the use of rituximab. During a 34-month follow-up period, the patient presented a slight clinical relapse, which was successfully controlled with prednisone in a daily dose of 120 mg, soon reduced to 20mg.

Severe Multi-Resistant Pemphigus vulgaris: prolonged remission with a single cycle of Rituximab / Penfigo vulgar grave Multirresistente: controle prolongado com um unico ciclo de Rituximabe

Pemphigus vulgaris is an autoimmune bullous disease whose therapy is based on systemic corticosteroids, with or without immunosuppressants. Rituximab is a chimeric monoclonal antibody of the IgG class, directed at a specific CD20 B cell surface antigen, used in pemphigus vulgaris empirically since 2002, with success in 90% of the cases and long periods of remission. Male patient, 33 years old, diagnosed with pemphigus vulgaris, confirmed by histopathology and direct immunofluorescence. He was treated for seven months with numerous treatments, including immunosuppressive drugs, with an unsatisfactory response, until he had complete remission with the use of rituximab. During a 34-month follow-up period, the patient presented a slight clinical relapse, which was successfully controlled with prednisone in a daily dose of 120mg, soon reduced to 20mg.

Pênfigo Vulgar é uma doença bolhosa auto-imune, cuja terapêutica é baseada em corticoesteróides sistêmicos, associados ou não a imunossupressores. Rituximabe é um anticorpo monoclonal quimérico da classe IgG direcionado a um antígeno CD20 de superfície celular específico da célula B, usado em pênfigo vulgar desde 2002, com sucesso em 90% e longos períodos de remissão. Paciente masculino, 33 anos, diagnóstico de pênfigo vulgar, confirmado por histopatologia e imunofluorescência direta. Durante 7 meses, recebeu inúmeros tratamentos com imunossupressores, apresentando resposta insatisfatória e progressão da doença, até que logo após a introdução de rituximabe teve completa remissão. Durante um acompanhamento de 34 meses, apresentou leve recidiva clínica, controlada com prednisona 120mg/dia, rapidamente reduzida e em uso atual de Prednisona 20mg/dia.

Mucosa-associated lymphoid tissue lymphoma of the trachea: case report.

CONTEXT: Mucosa-associated lymphoid tissue (MALT) lymphomas are most commonly found in the stomach, lungs, orbital soft tissue, salivary glands and thyroid. Involvement of the trachea is extremely rare. CASE REPORT: This report describes a rare case of MALT lymphoma of the trachea in a 71-year-old woman who presented with a one-year history of coughing, dyspnea, hoarseness and weight loss. There was an infiltrative lesion in the mid-trachea. The anatomopathological diagnosis was only made from the fifth endoscopic biopsy attempt. Immunochemotherapy consisting of rituximab, cyclophosphamide, vincristine and prednisone (R-COP) induced complete remission of the symptoms and endoscopic lesion. CONCLUSIONS: MALT lymphoma of the trachea is extremely rare and indolent disease. It has to be considered in the differential diagnosis of airway lesions. It is crucial to obtain an anatomopathological diagnosis from a specialized pathologist. Immunochemotherapy with R-COP induced complete remission of the disease.

Mucosa-associated lymphoid tissue lymphoma of the trachea: case report / Linfoma do tecido linfoide associado à mucosa de traqueia: relato de caso

CONTEXT: Mucosa-associated lymphoid tissue (MALT) lymphomas are most commonly found in the stomach, lungs, orbital soft tissue, salivary glands and thyroid. Involvement of the trachea is extremely rare. CASE REPORT: This report describes a rare case of MALT lymphoma of the trachea in a 71-year-old woman who presented with a one-year history of coughing, dyspnea, hoarseness and weight loss. There was an infiltrative lesion in the mid-trachea. The anatomopathological diagnosis was only made from the fifth endoscopic biopsy attempt. Immunochemotherapy consisting of rituximab, cyclophosphamide, vincristine and prednisone (R-COP) induced complete remission of the symptoms and endoscopic lesion. CONCLUSIONS: MALT lymphoma of the trachea is extremely rare and indolent disease. It has to be considered in the differential diagnosis of airway lesions. It is crucial to obtain an anatomopathological diagnosis from a specialized pathologist. Immunochemotherapy with R-COP induced complete remission of the disease.

CONTEXTO: Linfomas de tecido linfoide associado à mucosa (TLAM) são mais comumente encontrados no estômago, pulmões, órbita, glandulas salivares e tireoide. O envolvimento da traqueia é extremamente raro. RELATO DE CASO: Relato de caso raro de linfoma TLAM de traqueia, em mulher de 71 anos com tosse, dispneia, rouquidão e emagrecimento há um ano. Detectou-se lesão infiltrativa na porção média da traquéia. O diagnóstico anatomopatológico só foi obtido na biópsia do quinto procedimento endoscópico. A imunoquimioterapia R-COP (rituximabe, ciclofosfamida, vincristina e prednisona) induziu remissão completa dos sintomas e da lesão endoscópica. CONCLUSÕES: Linfoma TLAM de traqueia é uma doença indolente e extremamente rara, que deve ser considerada no diagnóstico diferencial das lesões de vias aéreas. O diagnóstico anatomopatológico por um patologista experimentado é fundamental. Imunoquimioterapia com R-COP levou à remissão completa da doença.

Behavioral changes in Rattus norvegicus experimentally infected by Toxocara canis larvae.

Toxocara canis is a common canine nematode parasite and one of its possible transmission mechanisms is the predation of infected rodents by canids. Fifty Rattus norvegicus were used to study behavioral alterations in rodents infected by T. canis larvae. The rats were divided into three groups: G1, 20 rats infected with 300 T. canis eggs; G2, 20 rats infected with 2,000 T. canis eggs; and G3, 10 non-infected rats. Thirty and 60 days post-infection, rats from all the groups were submitted to an open-field apparatus for five min and subsequently, to an elevated plus-maze apparatus, again for five min. The data obtained indicated improvement in mobility (total locomotion time and rearing frequency) and exploratory behavior in infected rats, principally in G2, which provides some support for the hypothesis that behavioral alterations in rodents infected by Toxocara canis larvae enhance the transmission rate of this ascarid to dogs.

Behavioral changes in Rattus norvegicus experimentally infected by Toxocara canis larvae / Alterações de comportamento em Rattus norvegicus experimentalmente infectados por larvas de Toxocara canis

Toxocara canis is a common canine nematode parasite and one of its possible transmission mechanisms is the predation of infected rodents by canids. Fifty Rattus norvegicus were used to study behavioral alterations in rodents infected by T. canis larvae. The rats were divided into three groups: G1, 20 rats infected with 300 T. canis eggs; G2, 20 rats infected with 2,000 T. canis eggs; and G3, 10 non-infected rats. Thirty and 60 days post-infection, rats from all the groups were submitted to an open-field apparatus for five min and subsequently, to an elevated plus-maze apparatus, again for five min. The data obtained indicated improvement in mobility (total locomotion time and rearing frequency) and exploratory behavior in infected rats, principally in G2, which provides some support for the hypothesis that behavioral alterations in rodents infected by Toxocara canis larvae enhance the transmission rate of this ascarid to dogs.

Toxocara canis é um nematódeo parasita habitual do intestino delgado de cães. Um dos mecanismos conhecidos de transmissão para cães é representado pela predação de pequenos roedores que, como hospedeiros paratênicos albergam larvas de Toxocara canis em seus tecidos. Para avaliar a ocorrência de alterações de comportamento em roedores infectados por Toxocara canis 50 exemplares de Rattus norvegicus foram utilizados no experimento. Os animais foram divididos em três grupos: G1 - 20 ratos infectados com 300 ovos de Toxocara canis; G2 - 20 ratos infectados com 2.000 ovos de Toxocara canis e G3 - 10 ratos sem infecção. Trinta e 60 dias após a infecção avaliou-se a ocorrência de alterações comportamentais nos três grupos submetendo os animais, primeiramente, a uma arena de campo aberto durante cinco minutos e, a seguir, a labirinto em cruz elevado por mais cinco minutos. Os resultados obtidos indicaram aumento significativo da mobilidade (tempo total de movimentação e número de vezes em que os animais se levantaram nas patas traseiras) e comportamento exploratório nos ratos infectados, principalmente nos pertencentes ao G2, sugerindo a ocorrência de alterações comportamentais que favoreceriam a transmissão de Toxocara canis para canídeos por meio de relação presa-predador.

[Pathogenic bacteria dissemination by ants (Hymenoptera: Formicidae) in two hospitals in northeast Brazil]. / Disseminação de bactérias patogênicas por formigas (Hymenoptera: Formicidae) em dois hospitais do nordeste do Brasil.

Nosocomial infections bring a high risk to the health of hospital patients and employees. Ants are common organisms in Brazilian hospitals, where they can act as dispersers of opportunistic microorganisms in places they forage. The occurrence of multi-resistant bacteria carried by ants was analyzed in two public hospitals (HA and HB) in southeastern Bahia, Brazil. In these two hospitals 132 workers belonging to three ant species were collected. The bacteria associated to these ants were identified and their susceptibility to antibiotics was evaluated. More than half (57.3%) of ants collected in HA were associated with some kind of bacteria, with 26.7% of them being opportunist bacteria, while 84,2% of the ants from HB presented associated bacteria growth, with 61.4% of them being opportunist bacteria. Twenty four species of bacteria were isolated. The Gram-positive bacilli of the genus Bacillus were the most frequent, followed by the Gram-positive cocci, Gram-negative bacilli (family Enterobacteriaceae) and Gram-negative non-fermenters bacilli. The profile of sensitivity of the bacterial isolates to drugs pointed out the existence of multi-resistant isolates carried by ants. For the first time, are reported cases of the same bacterial resistant isolates taken form homospecific ant workers that point out the importance of ants to bacteria dissemination and proliferation in a hospital. Our results suggest that the risk of contamination presented by these ants is similar to the one of any other mechanical vector of bacterial dissemination.

Disseminação de bactérias patogênicas por formigas (Hymenoptera: Formicidae) em dois hospitais do nordeste do Brasil / Pathogenic bacteria dissemination by ants (Hymenoptera: Formicidae) in two hospitals in northeast Brazil

Nosocomial infections bring a high risk to the health of hospital patients and employees. Ants are common organisms in Brazilian hospitals, where they can act as dispersers of opportunistic microorganisms in places they forage. The occurrence of multi-resistant bacteria carried by ants was analyzed in two public hospitals (HA and HB) in southeastern Bahia, Brazil. In these two hospitals 132 workers belonging to three ant species were collected. The bacteria associated to these ants were identified and their susceptibility to antibiotics was evaluated. More than half (57.3 percent) of ants collected in HA were associated with some kind of bacteria, with 26.7 percent of them being opportunist bacteria, while 84,2 percent of the ants from HB presented associated bacteria growth, with 61.4 percent of them being opportunist bacteria. Twenty four species of bacteria were isolated. The Gram-positive bacilli of the genus Bacillus were the most frequent, followed by the Gram-positive cocci, Gram-negative bacilli (family Enterobacteriaceae) and Gram-negative non-fermenters bacilli. The profile of sensitivity of the bacterial isolates to drugs pointed out the existence of multi-resistant isolates carried by ants. For the first time, are reported cases of the same bacterial resistant isolates taken form homospecific ant workers that point out the importance of ants to bacteria dissemination and proliferation in a hospital. Our results suggest that the risk of contamination presented by these ants is similar to the one of any other mechanical vector of bacterial dissemination.

Muscular strength decrease in Rattus norvegicus experimentally infected by Toxocara canis.

The muscular strength of experimental infected Rattus norvegicus with 3rd. stage Toxocara canis larvae was investigated. Fifty Wistar rats, divided in three groups (G1-20 rats infected by 300 eggs of T. canis; G2-20 rats infected by 2,000 eggs of T. canis and G3-10 rats without infection) had been used. Ten and 30 days after infection the muscular strength in the fore-feet of the rats was checked; at the same time, the body weight was determined. No significative differences in the body weight were noted among the infected and control rats in both occasions. Otherwise, an impairment on the muscular strength was observed in rats infected with T. canis 30 days after inoculation.

Muscular strength decrease in Rattus norvegicus experimentally infected by Toxocara canis / Diminuição da força muscular em Rattus norvegicus experimentalmente infectados por Toxocara canis

The muscular strength of experimental infected Rattus norvegicus with 3rd. stage Toxocara canis larvae was investigated. Fifty Wistar rats, divided in three groups (G1 - 20 rats infected by 300 eggs of T. canis; G2 - 20 rats infected by 2,000 eggs of T. canis and G3 - 10 rats without infection) had been used. Ten and 30 days after infection the muscular strength in the fore-feet of the rats was checked; at the same time, the body weight was determined. No significative differences in the body weight were noted among the infected and control rats in both occasions. Otherwise, an impairment on the muscular strength was observed in rats infected with T. canis 30 days after inoculation.

Roedores são reconhecidos como hospedeiros paratênicos de Toxocara canis. Um dos mecanismos de transmissão desse ascarídeo para cães, seus hospedeiros habituais, consiste na predação de hospedeiros paratênicos, que albergam larvas de terceiro estágio em seus órgãos e tecidos, entre os quais músculos estriados. No presente trabalho estudou-se se a infecção por larvas de Toxocara canis provoca alterações na força muscular de exemplares de Rattus norvegicus experimentalmente infectados. Cinqüenta Rattus norvegicus foram divididos em três grupos: G1, com 20 ratos infectados com 300 ovos de Toxocara canis; G2, com 20 ratos infectados com 2.000 ovos do ascarídeo e G3, com 10 ratos sem infecção. Dez e 30 dias após a infecção determinou-se a força muscular nas patas dianteiras dos roedores; ao mesmo tempo, avaliou-se seu peso corporal. Não foram observadas diferenças no peso dos animais dos três grupos; contudo, verificou-se decréscimo na força muscular dos ratos infectados com 2.000 ovos após o 30º dia de infecção.

Lagochilascariasis leading to severe involvement of ocular globes, ears and meninges.

A case report of a 31 year-old woman from Paraíba State (North-Eastern Brazil) that presented severe involvement of ocular globes, ears and meninges. Diagnosis was established after enucleation of her left eye, when adult worms were seen in the midst of a granulomatous inflammatory process. Her response to the initial treatment with levamisole and cambendazole was good, but there was a relapse after the fifth month of treatment even with maintenance doses of both medications. She later received ivermectin and albendazol and responded well.

Lagochilascariasis leading to severe involvement of ocular globes, ears and meninges / Infecção humana por Lagochilascaris minor com envolvimento ocular, auditivo e das meninges

A case report of a 31 year-old woman from Paraíba State (North-Eastern Brazil) that presented severe involvement of ocular globes, ears and meninges. Diagnosis was established after enucleation of her left eye, when adult worms were seen in the midst of a granulomatous inflammatory process. Her response to the initial treatment with levamisole and cambendazole was good, but there was a relapse after the fifth month of treatment even with maintenance doses of both medications. She later received ivermectin and albendazol and responded well.

Paciente do sexo feminino, com 31 anos, procedente da Paraíba, apresentava envolvimento severo de ambos os globos oculares, com perda da visão à esquerda, comprometimento da audição e das meninges. Após enucleação do olho esquerdo fragmento de helminto identificado como Lagochilascaris minor foi observado em processo inflamatório granulomatoso. Inicialmente a paciente foi tratada com levamisol e cambendazol, com bom resultado. Verificou-se, todavia, piora do quadro após cinco meses, com eliminação de larvas do ascarídeo em lesão presente na órbita esquerda, embora a medicação fosse mantida com administração periódica. Houve boa resposta terapêutica, com regressão do quadro, após substituição dos anti-helmínticos anteriores pela associação ivermectina e albendazol.

Sulfasalazine-induced DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms).

CONTEXT: DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms) is a type of drug reaction commonly mistaken for a viral infection. It must be recognized promptly due to its high morbidity and 10% mortality rate. Few cases of DRESS syndrome induced by sulfasalazine have been reported in the literature. CASE REPORT: The case of a 47-year-old white Brazilian woman who developed DRESS syndrome eight weeks after starting a course of sulfasalazine for treatment of seronegative arthritis is reported. She presented a skin rash, fever, hepatitis, lymphadenopathy, eosinophilia and atypical lymphocytes. The causative drug was discontinued immediately, but she only improved after treatment with prednisone.

Sulfasalazine-induced DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms) / Síndrome DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) induzida por sulfasalazina

CONTEXT: DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms) is a type of drug reaction commonly mistaken for a viral infection. It must be recognized promptly due to its high morbidity and 10 percent mortality rate. Few cases of DRESS syndrome induced by sulfasalazine have been reported in the literature. CASE REPORT: The case of a 47-year-old white Brazilian woman who developed DRESS syndrome eight weeks after starting a course of sulfasalazine for treatment of seronegative arthritis is reported. She presented a skin rash, fever, hepatitis, lymphadenopathy, eosinophilia and atypical lymphocytes. The causative drug was discontinued immediately, but she only improved after treatment with prednisone.

CONTEXTO: A síndrome DRESS (Drug Rash with Eosinophilia and Systemic Symptoms) é um tipo de reação a drogas comumente confundida com uma infecção viral. Deve ser prontamente reconhecida devido a sua alta morbidade e taxa de mortalidade de 10 por cento. Poucos casos de síndrome DRESS induzida por sulfasalazina foram relatados na literatura. RELATO DE CASO: É relatado o caso de uma mulher branca, brasileira, de 47 anos, que desenvolveu a síndrome DRESS oito semanas após iniciar tratamento com sulfasalazina para artrite soronegativa. A paciente apresentou rash maculopapular, febre, hepatite, linfadenomegalia, eosinofilia e linfocitose atípica. A medicação foi suspensa imediatamente no início dos sintomas, mas só houve melhora clínica após tratamento com prednisona.

Baixas concentrações de colesterol: suas relações com comportamento de risco / Low cholesterol: it correlation with high-risk behaviors

Apesar de resultados discordantes, evidências sugerem que baixas concentrações de colesteroi podem estar associadas a uma variedade de traços de personalidade e atitudes potencialmente relevantes à associação com mortes violentas. Caso comprova- da uma relação d e causalidade nesta associação, a preocupação com as alterações comportamentais, particularmente o aumento de eventos violentos, deve passar a figurar na análise do risco-benefício para a redução do colesterol, sobretudo na prevenção primária da doença cardiovascular em indivíduos com fatores de risco para doença psiquiátrica ou violência. As intervenções para redução do colesteroi em larga escala podem levar a um desvio do comportamento de toda a população para um padrão mais violento. Por outro lado, se este receio for infundado, não deve prejudicar os programas de prevenção da doença cardiovascular já instituídos em várias regiões do planeta. Este artigo traz uma revisão da literatura relativa a baixas concentrações de colesterol, incluindo dados epidemiológicos, estudos de mortalidade global e mortes por violência, além de discutir possíveis mecanismos que justifiquem a associação entre violência e baixo colesterol.(au)