RESUMO
Halite (NaCl mineral) has exhibited the potential to preserve microorganisms for millions of years on Earth. This mineral was also identified on Mars and in meteorites. In this study, we investigated the potential of halite crystals to protect microbial life-forms on the surface of an airless body (e.g., meteorite), for instance, during a lithopanspermia process (interplanetary travel step) in the early Solar System. To investigate the effect of the radiation of the young Sun on microorganisms, we performed extensive simulation experiments by employing a synchrotron facility. We focused on two exposure conditions: vacuum (low Earth orbit, 10-4 Pa) and vacuum-ultraviolet (VUV) radiation (range 57.6-124 nm, flux 7.14 W/m2), with the latter representing an extreme scenario with high VUV fluxes comparable to the amount of radiation of a stellar superflare from the young Sun. The stellar VUV parameters were estimated by using the very well-studied solar analog of the young Sun, κ1 Cet. To evaluate the protective effects of halite, we entrapped a halophilic archaeon (Haloferax volcanii) and a non-halophilic bacterium (Deinococcus radiodurans) in laboratory-grown halite. Control groups were cells entrapped in salt crystals (mixtures of different salts and NaCl) and non-trapped (naked) cells, respectively. All groups were exposed either to vacuum alone or to vacuum plus VUV. Our results demonstrate that halite can serve as protection against vacuum and VUV radiation, regardless of the type of microorganism. In addition, we found that the protection is higher than provided by crystals obtained from mixtures of salts. This extends the protective effects of halite documented in previous studies and reinforces the possibility to consider the crystals of this mineral as potential preservation structures in airless bodies or as vehicles for the interplanetary transfer of microorganisms.
Assuntos
Cloreto de Sódio , Raios Ultravioleta , Raios Ultravioleta/efeitos adversos , Cloreto de Sódio/química , Sais , Vácuo , MineraisRESUMO
O schwanoma vestibular é uma neoplasia que se origina das células de Schwann da porção vestibular do VIII nervo craniano e que corres- ponde a cerca de 10% dos tumores intracranianos e a 80% a 90% daqueles localizados no ângulo pontocerebelar. Apesar do crescimento lento e evolução em geral benigna, estes tumores podem evoluir de maneira desfavorável devido à localização em compartimento anatômico relativamente reduzido no crânio (fossa posterior), o que pode levar a compressão de estruturas nobres (como o tronco encefálico) e a desenvolvimento de hidrocefalia obstrutiva, especialmente nos raros casos de schawanomas gigantes (> 40 mm). Apresentamos relato de caso de paciente com quadro de tinnitus e hipoacusia à esquerda que evoluiu de forma subaguda com alterações do humor, da cognição e da marcha cujo diagnóstico final foi de schwanoma gigante do VIII nervo craniano.
Vestibular schwannoma is a Schwann cells neoplasia of the vestibular branch of the VIII cranial nerve and it accounts for 10% of intracranial tumours and to 80%-90% of those located at the cerebellopontine angle. Despite slow growth and usual benign evolution, unfavourable outcomes may occur, especially in the rare cases of giant schwanno- mas (> 40mm). Owing the fact that this tumours are located in a relatively narrow space (posterior fossa), giant schwannomas may compress noble areas (as the brainstem), which can also cause obstructive hydrocephalus. We discuss a case report of a 48 years old woman complaining of left-sided hearing loss and tinnitus that developed a subacute cognitive impairment, mood disorder and gait disturbance, diagnosed with giant schwannoma of the VIII nerve.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Neuroma Acústico/cirurgia , Neuroma Acústico/complicações , Neuroma Acústico/diagnóstico , Neoplasias dos Nervos Cranianos/diagnóstico , Imageamento por Ressonância Magnética/métodos , Transtornos Cognitivos/etiologia , Progressão da Doença , Transtornos do Humor/etiologia , Perda Auditiva/etiologiaRESUMO
A novel GH1 ß-glucosidase (EaBgl1A) from a bacterium isolated from Antarctica soil samples was recombinantly overexpressed in Escherichia coli cells and characterized. The enzyme showed unusual pH dependence with maximum activity at neutral pH and retention of high catalytic activity in the pH range 6 to 9, indicating a catalytic machinery compatible with alkaline conditions. EaBgl1A is also a cold-adapted enzyme, exhibiting activity in the temperature range from 10 to 40°C with optimal activity at 30°C, which allows its application in industrial processes using low temperatures. Kinetic characterization revealed an enzymatic turnover (Kcat) of 6.92s(-1) (cellobiose) and 32.98s(-1) (pNPG) and a high tolerance for product inhibition, which is an extremely desirable feature for biotechnological purposes. Interestingly, the enzyme was stimulated by up to 200 mM glucose, whereas the commercial cocktails tested were found fully inhibited at this concentration. These properties indicate EaBgl1A as a promising biocatalyst for biotechnological applications where low temperatures are required.
Assuntos
Adaptação Biológica , Bacillaceae/enzimologia , Bacillaceae/genética , Temperatura Baixa , beta-Glucosidase/química , beta-Glucosidase/genética , Carboidratos/química , Catálise , Clonagem Molecular , Ativação Enzimática , Expressão Gênica , Concentração de Íons de Hidrogênio , Cinética , Análise de Sequência de DNA , Especificidade por Substrato , beta-Glucosidase/isolamento & purificaçãoRESUMO
Exiguobacterium antarcticum is a psychotropic bacterium isolated for the first time from microbial mats of Lake Fryxell in Antarctica. Many organisms of the genus Exiguobacterium are extremophiles and have properties of biotechnological interest, e.g., the capacity to adapt to cold, which make this genus a target for discovering new enzymes, such as lipases and proteases, in addition to improving our understanding of the mechanisms of adaptation and survival at low temperatures. This study presents the genome of E. antarcticum B7, isolated from a biofilm sample of Ginger Lake on King George Island, Antarctic peninsula.
Assuntos
Bacillales/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Análise de Sequência de DNA , Regiões Antárticas , Bacillales/isolamento & purificação , Bacillales/fisiologia , Biofilmes/crescimento & desenvolvimento , Água Doce/microbiologia , Ilhas , Lagos , Dados de Sequência MolecularRESUMO
The purpose of this study was to determine the effect of functional limitations and fatigue on the quality of life (QoL) in people with multiple sclerosis (MS). A descriptive case series study at Lagoa Hospital - Rio de Janeiro, Brazil was carried. The main outcome measurements were demographic variables, QoL (SF-36 v.1), disability (EDSS), motor function of the upper limb (Box & Blocks test), Tone (Modified Ashworth Scale), gait (Hauser ambulatory index) and fatigue (Fatigue Severity Scale). Sixty one patients fulfilled the study criteria. The mean age of patients was 39 years and 74% of patients were female. The most of cases presented mild disability (EDSS<3.5). A decrease was found in all domains of QoL. It was found association between physical functioning and the variables of EDSS, fatigue, lower limb tone and gait. Gait, disability, hypertonia of the lower limbs and fatigue negatively affected QoL in people with MS.
Assuntos
Avaliação da Deficiência , Fadiga/etiologia , Esclerose Múltipla/psicologia , Qualidade de Vida/psicologia , Adulto , Fadiga/psicologia , Feminino , Humanos , Masculino , Esclerose Múltipla/complicações , Índice de Gravidade de DoençaRESUMO
The purpose of this study was to determine the effect of functional limitations and fatigue on the quality of life (QoL) in people with multiple sclerosis (MS). A descriptive case series study at Lagoa Hospital - Rio de Janeiro, Brazil was carried. The main outcome measurements were demographic variables, QoL (SF-36 v.1), disability (EDSS), motor function of the upper limb (Box & Blocks test), Tone (Modified Ashworth Scale), gait (Hauser ambulatory index) and fatigue (Fatigue Severity Scale). Sixty one patients fulfilled the study criteria. The mean age of patients was 39 years and 74 percent of patients were female. The most of cases presented mild disability (EDSS<3.5). A decrease was found in all domains of QoL. It was found association between physical functioning and the variables of EDSS, fatigue, lower limb tone and gait. Gait, disability, hypertonia of the lower limbs and fatigue negatively affected QoL in people with MS.
O objetivo do estudo foi determinar o efeito das limitações funcionais e da fadiga na qualidade de vida (qv) de indivíduos com esclerose múltipla (em). foi conduzido um estudo descritivo de série de casos no Hospital da Lagoa - Rio de Janeiro, Brasil. As principais medidas utilizadas foram as variáveis demográficas, QV (SF-36 v.1), incapacidade (EDSS), função motora da extremidade superior (Teste da Caixa e Blocos), Tônus (Escala Modificada de Ashworth), marcha (Índice Ambulatorial de Hauser) e fadiga (Escala de Severidade de Fadiga). Sessenta e um pacientes preencheram os critérios do estudo. A média de idade foi de 39 anos e 74 por cento dos pacientes eram do gênero feminino. A maioria dos casos apresentou incapacidade leve (EDSS<3,5). Foi encontrada uma diminuição em todas dimensões da QV. Foi observada uma associação entre a função física e as variáveis EDSS, fadiga, tônus dos membros inferiores e marcha. Marcha, incapacidade, hipertonia dos membros inferiores e fadiga afetam negativamente a QV de indivíduos com EM.
Assuntos
Adulto , Feminino , Humanos , Masculino , Avaliação da Deficiência , Fadiga/etiologia , Esclerose Múltipla/psicologia , Qualidade de Vida/psicologia , Fadiga/psicologia , Esclerose Múltipla/complicações , Índice de Gravidade de DoençaRESUMO
Introdução: A esclerose múltipla (EM) é uma doença neurológica progressiva que tipicamente resulta em limitação funcional. Objetivo: Comparar escalas funcionais em pacientes com EM. Materiais e métodos: Foi realizado um estudo observacional no Hospital da Lagoa, Rio de Janeiro, em 71 pacientes. Foram coletadas as variáveis demográficas, avaliação funcional (Índice de Barthel IB e Escala do Estado de Incapacidade - EEI); qualidade de vida; incapacidade; marcha; fadiga. Resultados: A média de idade foi de 40 anos, com duração média de doença de 8 anos. Foi observada uma maior correlação entre o EEI e as outras variáveis. A magnitude das correlações do EEI foi superior às do IB. A EEI foi a única escala que apresentou correlação com fadiga e se correlacionou mais com a qualidade de vida. Conclusões: A EEI se mostrou superior ao IB por se correlacionar com os principais comprometimentos dos pacientes, sendo mais completa e conter itens específicos da EM.
Introduction: Multiple Sclerosis (MS) is a progressive neurological disease that typically results in functional limitation. Objective: To compare functional scales on MS patients. Material and methods: An observational study was performed in Lagoa Hospital, Rio de Janeiro, on 71 patients. It was collected demographic variables, functional evaluation (Barthel Index Scale-BI and Incapacity Status Scale-ISS); quality of life; disability; gait and fatigue. Results: The mean age was 40 years, with average duration of illness of 8 years. It was observed greater correlation between the ISS and other variables. The magnitude of the ISS correlations was superior to the BI. The ISS was the only scale that shows correlation with fatigue and some dimensions of quality of life. Conclusions: The ISS was better than the BI because it is correlated with the main activities of patients, is more comprehensive and contains specific items to MS.