RESUMO
Enzymatic lipophilization is an important process to extend the use of anthocyanins in lipidic media. In this work delphinidin 3-O-sambubioside (Dp3sam) isolated from Hibiscus sabdariffa L. flower was esterified with octanoic acid using Candida antarctica lipase B. The physical-chemical properties of the new lipophilic pigment were studied by UV-vis spectroscopy. Dp3sam with chloride, acetate and formate as counter ions were employed to study the lipophilization reaction. The hydrolysis of the reagent was avoided with a formate counter ion and the expected product was achieved with a noteworthy change of solubility. 1D and 2D NMR characterization of Dp3sam-C8 confirmed that the lipophilization took place at the primary alcohol of the glucoside moiety. Overall, the Dp3sam-C8 ester presents a stabilization of the quinoidal base (blue color) at neutral or moderate alkaline pH, which foresees a potential use of this pigment as a broad kind of industries on lipo-soluble formulations.
Assuntos
Antocianinas/análise , Ácidos Graxos/metabolismo , Proteínas Fúngicas/metabolismo , Hibiscus/química , Lipase/metabolismo , Acilação , Antocianinas/isolamento & purificação , Antocianinas/metabolismo , Biocatálise , Cromatografia Líquida de Alta Pressão , Cor , Dissacarídeos/química , Hibiscus/metabolismo , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Extratos Vegetais/química , Extração em Fase SólidaRESUMO
ABSTRACT Piper permucronatum is a perennial shrub, a medicinal plant native to the Amazon Rainforest. Traditionally, the tea of its leaves is used to combat menstrual and intestinal cramps, stomach pain, digestive problems, diarrhea, hemorrhage, and nausea. Its leaf’s essential oil is effective against Aedes aegypti larvae; its flavones and flavanones have a fungicidal effect against Clamidosporium cladosporioides and C. sphaerospermum; its hexanic extract is effective against Leishmania amazonensis. The objective of this study was to provide a protocol for callus induction from P. permucronatum leaves and an identification of the callus growth pattern, focusing on the deceleration phase, when the callus cells must be subcultured into liquid medium in order to produce a cell suspension cultures. Leaf explants were inoculated in a solid MS medium supplemented with factorial combinations of 2,4-D, BA, NAA and GA3. Callus formation was evaluated weekly until the 49th day. Subsequently, new explants were inoculated at the hormonal combination that resulted in the highest callus cell proliferation and, every seven days during a period of 70 days, samples were dried and weighed to determine the callus growth pattern. NAA and GA3 were not effective for callus induction. Combinations of 2,4-D and BA resulted in callus induction and proliferation. The highest percentage of callus induction was observed with the combination of 4.52 µM 2,4-D and 4.44 µM BA. The calluses thereby produced were friable and whitish. The callus growth pattern followed a sigmoid shape. The deceleration phase started on the 56th day of culture.
RESUMO Indução e padrão de crescimento de calos de folhas de Piper permucronatum. Piper permucronatum é um arbusto perene, uma planta medicinal native da Floresta Amazônica. Tradicionalmente, o chá de suas folhas é usado em casos de cólicas menstruais e intestinais, dores de estômago, problemas digestivos, diarreia, hemorragia e náusea. O óleo essencial das folhas é efetivo contra a larva de Aedes aegypti; suas flavonas e flavanonas têm efeito fungicida contra Clamidosporium cladosporioides e C. sphaerospermum; seu extrato hexânico é efetivo contra Leishmania amazonensis. O objetivo deste trabalho foi determinar um protocolo para indução de calos em folhas de P. permucronatum e identificar o padrão de crescimento dos calos, com foco na fase de desaceleração, quando as células de calo devem ser subcultivadas em meio líquido para produzir culturas de células em suspensão. Explantes foliares foram inoculados em meio MS sólido suplementado com combinações fatoriais de 2,4-D, BAP, ANA e GA3. A formação de calos foi avaliada semanalmente até o 49º dia. Posteriormente, novos explantes foram inoculados na combinação hormonal que resultou na maior proliferação de células de calo e, a cada sete dias durante 70 dias, amostras foram secas e pesadas para determinar o padrão de crescimento dos calos. ANA e GA3 não foram efetivas para a indução de calos. Combinações de 2,4-D e BAP resultaram em indução e proliferação de calos. A maior porcentagem de indução de calos foi observada com a combinação de 4,52 µM de 2,4-D e 4,44 µM de BAP. Os calos produzidos eram friáveis e esbranquiçados. O crescimento dos calos seguiu um padrão sigmoide. A fase de desaceleração iniciou no 56º dia de cultivo.
Assuntos
Reguladores de Crescimento de Plantas/análise , Piperaceae/classificação , Plantas Medicinais/classificação , DesaceleraçãoRESUMO
Este trabalho teve por objetivo identificar as plantas medicinais de uso popular e o perfil socioeconômico de seus usuários em área urbana de Ouro Preto, MG. O levantamento utilizou entrevistas semiestruturadas e amostragem aleatória, perfazendo 10% das residências. O grau de conhecimento sobre plantas medicinais foi medido pelo número de espécies citadas. Analisou-se a relação entre o saber popular sobre as plantas medicinais e características socioeconômicas dos entrevistados (renda, escolaridade, sexo, idade e forma de aquisição do conhecimento). Foram questionadas 6.713 pessoas, onde mais de 90% usam plantas medicinais para se tratarem. Identificou-se 342 espécies, reunidas em 94 famílias. Para cada espécie foram referidos os nomes populares, hábito, procedência, uso medicinal, parte usada, e forma de preparo. As principais moléstias tratadas com plantas foram: diarreia, insônia, gripe, hidropisia, distúrbios hepáticos, renais e do trato respiratório. Há um grande número de espécies nativas utilizadas. Dentre as exóticas, a maioria é de origem europeia. O uso místico de espécies, embora presente na cultura popular do município, foi pouco citado. Algumas espécies identificadas figuram na lista das espécies ameaçadas de extinção. O grau de conhecimento sobre plantas medicinais pela população de Ouro Preto independe, tanto do nível econômico, como da escolaridade ou do sexo. A idade e a forma de aquisição do conhecimento influenciam no saber popular das ervas medicinais. As pessoas com maior saber popular sobre as plantas adquiriram esses conhecimentos principalmente pelo costume familiar, por livros, ou por outras pessoas. Pessoas mais jovens conhecem menos espécies medicinais que as mais idosas, sugerindo risco de perda desse conhecimento tradicional. A grande riqueza de plantas citadas neste trabalho denota a importância de estudos etnobotânicos no resgate do conhecimento tradicional em áreas urbanas, tanto pelo seu valor histórico-cultural, como pela importância científica.
This work aimed to identify the medicinal plants of popular use and the socioeconomic profile of the users in the urban area of Ouro Preto, state of Minas Gerais, Brazil. The survey was carried out with random sampling and semi-structured interviews, amounting to 10% of households. The degree of knowledge about medicinal plants was measured by the number of species mentioned. The relationship between the popular knowledge about medicinal plants and the socioeconomic characteristics of the users (income, education, gender, age and type of knowledge acquisition) was also studied. In this survey, 6,713 inhabitants were questioned, of whom more than 90% use medicinal plants. A total of 342 species grouped in 94 families were identified. The popular names, growth habit, habitat, medicinal uses, part used and method of preparation are listed for each identified species. The main ailments treated with plants were diarrhea, insomnia, flu, dropsy and liver, renal and respiratory tract disorders. There is a large number of native species. Among the exotic ones, most are of European origin. The spiritual use of species, although present in the popular culture of the city, was negligible. Some species figure on the Brazilian red lists. It was noted that knowledge of medicinal plants by the population of Ouro Preto, in species richness, is not related to income, class, educational level and gender. The age and manner of acquisition of empirical knowledge about medicinal plants are associated with the number of species listed. Persons with greater popular knowledge about medicinal plants acquired information through family tradition, books and from other persons. Younger persons know fewer medicinal plants than the older ones, what suggests a loss of this traditional knowledge. The richness of the plants mentioned in this paper demonstrates the importance of ethnobotanical studies in the rescue of traditional knowledge in urban areas, for its scientific, historical and cultural values.
Assuntos
Humanos , Masculino , Feminino , Plantas Medicinais/anatomia & histologia , Classe Social , Área Urbana , Participação da Comunidade/estatística & dados numéricos , Etnobotânica/métodosRESUMO
The Kalanchoe pinnata Lam. is a bush species of the Crassulaceae that is distinguished by its important medicinal properties. Its leaves are used as cataplasm to treat headaches and wounds. There is evidence for a hypotensive and anti-inflammatory effect. Techniques of plant tissue culture have been applied to plant species that produce substances likely to be explored in pharmacology, cell suspension being the main technique. At the industrial level, this method utilizes bioreactors in order to produce secondary metabolites on a large scale. The objective of this study was to evaluate the effects of in vitro combinations of 2,4-dichlorophenoxiacetic acid (2,4-D) and benzylaminopurine (BA) on callus induction in leaf explants of K. pinnata. Leaf fragments were inoculated in MS medium supplemented with 3.0% sucrose, 0.8% agar and factorial combinations of 2,4-D (0.00, 4.52, 9.06, 18.12 µM) and BA (0.00, 4.44, 8.88, 17.76 µM). The cultures were kept in the darkness at 24±2ºC for 50 days. The percentage of callus induction and the area of explants covered by callus cells were evaluated. In the absence of growth regulators, callus induction did not occur, with necrosis of all explants. The highest percentage of callus induction was 100%, obtained with the combination of 9.06 µM 2,4-D and 8.88 µM BA, but the calluses covered only 25% of the leaf area. The most efficient combination was 4.52 µM 2,4-D and 8.88 µM BA, resulting in 91% callus induction with 50 to 100% of the explants being covered by callus cells.
Kalanchoe pinnata Lam. é uma espécie arbustiva da família Crassulaceae que apresenta interessantes propriedades medicinais. Suas folhas são utilizadas em cataplasma para tratar enxaqueca e ferimentos. Há evidência de seu efeito como hipotensiva e anti-inflamatória. Técnicas de cultura de tecidos vegetais têm sido aplicadas para espécies que possuem substâncias passíveis de exploração na farmacologia, sendo a suspensão celular a principal técnica utilizada. A nível industrial, este método utiliza biorreatores para produzir metabólitos secundários em larga escala. Este estudo teve como objetivo avaliar os efeitos in vitro de combinações do ácido 2,4-diclorofenoxiacético (2,4-D) e de benzilaminopurina (BAP) na indução de calos em explantes foliares de K. pinnata. Fragmentos foliares foram inoculados em meio MS contendo 3% de sacarose, 0,8% de ágar e combinações fatoriais de 2,4-D (0,00; 4,52; 9,06 e 18,12 µM) e BAP (0,00; 4,44; 8,88 e 17,76 µM). Os cultivos foram mantidos no escuro, a 24±2ºC por 50 dias. A porcentagem de indução de calos e a área dos explantes coberta por células de calos foram avaliadas. Na ausência de reguladores de crescimento não ocorreu indução de calos, com necrose de todos os explantes. A porcentagem mais alta de indução de calos foi de 100%, obtida com a combinação de 9,06 µM de 2,4-D e 8,88 µM de BAP, mas estes calos cobriram apenas 25% da área foliar. A combinação mais eficiente foi de 9,06 µM de 2,4-D e 8,88 µM de BAP, que resultou em 91% de indução e 50 a 100% da área dos explantes coberta por células de calos.
Assuntos
Reguladores de Crescimento de Plantas/análise , Kalanchoe/classificação , Plantas Medicinais/classificação , Ácido 2,4-Diclorofenoxiacético/farmacologiaRESUMO
BACKGROUND AND OBJECTIVE: Curcumin is a plant-derived dietary spice with various biological activities, including anticarcinogenic and anti-inflammatory effects. Its therapeutic applications have been studied in a variety of conditions, including rheumatoid arthritis, colon cancer and depression, but no studies have evaluated the effects of curcumin on periodontal disease in vivo. MATERIAL AND METHODS: Experimental periodontal disease was induced in rats by placing cotton ligatures around both lower first molars. Curcumin was given to the rats by the intragastric route daily at two dosages (30 and 100 mg/kg) for 15 d. Control animals received ligatures but only the corn oil vehicle by gavage, and no treatment-negative control animals were included. Bone resorption was assessed by micro-computed tomography, and the inflammatory status was evaluated by stereometric analysis. Both RT-qPCR and ELISA were used to determine the expression of interleukin-6, tumor necrosis factor-α and prostaglandin E(2) synthase in the gingival tissues. Modulation of p38 MAPK and nuclear factor-κB activation were assessed by western blotting. RESULTS: Bone resorption was effectively induced in the experimental period, but it was not affected by either dose of curcumin. Curcumin effectively inhibited cytokine gene expression at both the mRNA and the protein level and produced a dose-dependent inhibition of the activation of nuclear factor-κB in the gingival tissues. Activation of p38 MAPK was not inhibited by curcumin. Curcumin-treated animals also presented a marked reduction of the inflammatory cell infiltrate and increased collagen content and fibroblastic cell numbers. CONCLUSION: Curcumin did not prevent alveolar bone resorption, but its potent anti-inflammatory effect suggests that it may have a therapeutic potential in periodontal diseases.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Curcumina/uso terapêutico , Periodontite/prevenção & controle , Perda do Osso Alveolar/prevenção & controle , Processo Alveolar/efeitos dos fármacos , Processo Alveolar/patologia , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Contagem de Células , Colágeno/efeitos dos fármacos , Curcumina/administração & dosagem , Ciclo-Oxigenase 2/análise , Relação Dose-Resposta a Droga , Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Gengiva/patologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Inflamação , Interleucina-6/análise , Oxirredutases Intramoleculares/análise , Masculino , NF-kappa B/análise , NF-kappa B/efeitos dos fármacos , Prostaglandina-E Sintases , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Microtomografia por Raio-X/métodos , Proteínas Quinases p38 Ativadas por Mitógeno/análise , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacosRESUMO
BACKGROUND AND PURPOSE: Compound LASSBio-881 is an orally effective antinociceptive that binds to cannabinoid receptors and is active mainly on the neurogenic component of pain models. We investigated whether transient receptor potential vanilloid subfamily type 1 (TRPV1) channels are involved in the effects of LASSBio-881. EXPERIMENTAL APPROACH: Modulation of capsaicin (CAP)- and low pH-induced currents was evaluated in TRPV1-expressing Xenopus oocytes. In vivo effects were evaluated in CAP-induced acute and inflammatory changes in nociception, as well as in partial sciatic ligation-induced thermal hypernociception. KEY RESULTS: LASSBio-881 inhibited TRPV1 currents elicited by CAP with an IC(50) of 14 microM, and inhibited proton-gated currents by 70% at 20 microM. Functional interaction with CAP was surmountable. Locally applied LASSBio-881 decreased time spent in CAP-elicited nocifensive behaviour by 30%, and given orally it reduced measures of CAP- or carrageenan-evoked thermal hypernociception by 60 and 40% respectively. In addition, LASSBio-881 decreased the paw withdrawal responses to thermal stimuli of animals with sciatic neuropathy 7-11 days after nerve ligation, at a dose of 300 micromol*kg(-1)*day(-1) p.o. At this dose, hyperthermia was not observed within 4 h following oral administration. CONCLUSIONS AND IMPLICATIONS: LASSBio-881 is a TRPV1 antagonist that apparently competes with CAP. Accordingly, LASSBio- 881 inhibited nociception in models of acute, inflammatory and neuropathic pain presumed to involve TRPV1 signalling. These in vivo actions were not hindered by hyperthermia, a common side effect of other TRPV1 antagonists. We propose that the antinociceptive properties of LASSBio-881 are due to TRPV1 antagonism, although other molecular interactions may contribute to the effects of this multi-target drug candidate.
Assuntos
Analgésicos/uso terapêutico , Capsaicina/farmacologia , Hidrazinas/uso terapêutico , Dor/tratamento farmacológico , Nervo Isquiático/cirurgia , Canais de Cátion TRPV/antagonistas & inibidores , Administração Oral , Analgésicos/administração & dosagem , Animais , Feminino , Hidrazinas/administração & dosagem , Camundongos , Dor/induzido quimicamente , Dor/etiologia , Ratos , Ratos Wistar , Xenopus laevisAssuntos
Folículo Piloso/patologia , Doenças da Unha/etiologia , Doenças da Unha/patologia , Transtornos da Pigmentação/etiologia , Transtornos da Pigmentação/patologia , Adulto , Biópsia , Folículo Piloso/metabolismo , Humanos , Queratina-19/metabolismo , Lasers de Gás , Terapia com Luz de Baixa Intensidade , Doenças da Unha/radioterapia , Unhas/patologia , Transtornos da Pigmentação/radioterapiaRESUMO
Physical training induces beneficial adaptations; however, exhausting exercise increases reactive oxygen species generation, resulting in damage to DNA and tissues. Pequi (Caryocar brasiliense), a fruit of the Brazilian Cerrado, contains a carotenoid-rich oil. We investigated whether pequi oil had antioxidant effects in runners. Evaluations were made after outdoor races before and after ingestion of 400 mg pequi-oil capsules for 14 days. Blood samples were taken after races and submitted to comet and TBARS assays and biochemical analyses of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). To determine if the protective effects of pequi-oil were influenced by antioxidant enzyme genotypes, MnSOD (-Val9Ala), CAT (-21A/T) and GPX1 (Pro198Leu) gene polymorphisms were also investigated. Pequi oil was efficient in reducing tissue injuries evaluated for AST and ALT, particularly in women, and in reducing DNA damages in both sexes. Except for CK levels, the results were influenced by MnSOD genotypes; heterozygous excess was related to less DNA damage, tissue injury and lipid peroxidation, besides presenting a better response to pequi oil against exercise-induced damage.
Assuntos
Alanina/genética , Carotenoides/análise , Dano ao DNA/efeitos dos fármacos , Dieta , Peroxidação de Lipídeos/efeitos dos fármacos , Óleos de Plantas/farmacologia , Polimorfismo Genético , Corrida , Superóxido Dismutase/genética , Valina/genética , Adolescente , Adulto , Humanos , Óleos de Plantas/química , Superóxido Dismutase/químicaRESUMO
BACKGROUND AND OBJECTIVE: Cyclosporine A treatment is important in the therapy of a number of medical conditions; however, alveolar bone loss is an important negative side-effect of this drug. As such, we evaluated whether concomitant administration of simvastatin would minimize cyclosporine A-associated alveolar bone loss in rats subjected, or not, to experimental periodontal disease. MATERIAL AND METHODS: Groups of 10 rats each were treated with cyclosporine A (10 mg/kg/day), simvastatin (20 mg/kg/day), cyclosporine A and simvastatin concurrently (cyclosporine A/simvastatin) or vehicle for 30 days. Four other groups of 10 rats each received a cotton ligature around the lower first molar and were treated similarly with cyclosporine A, simvastatin, cyclosporine A/simvastatin or vehicle. Calcium (Ca(2+)), phosphorus and alkaline phosphatase levels were evaluated in serum. Expression levels of interleukin-1beta, prostaglandin E(2) and inducible nitric oxide synthase were evaluated in the gingivomucosal tissues. Bone volume and numbers of osteoblasts and osteoclasts were also analyzed. RESULTS: Treatment with cyclosporine A in rats, with or without ligature, was associated with bone loss, represented by a lower bone volume and an increase in the number of osteoclasts. Treatment with cyclosporine A was associated with bone resorption, whereas simvastatin treatment improved cyclosporine A-associated alveolar bone loss in all parameters studied. In addition, simvastatin, in the presence of inflammation, can act as an anti-inflammatory agent. CONCLUSION: This study shows that simvastatin therapy leads to a reversal of the cyclosporine A-induced bone loss, which may be mediated by downregulation of interleukin-1beta and prostaglandin E(2) production.
Assuntos
Perda do Osso Alveolar/induzido quimicamente , Ciclosporina/efeitos adversos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Imunossupressores/efeitos adversos , Sinvastatina/farmacologia , Fosfatase Alcalina/sangue , Perda do Osso Alveolar/fisiopatologia , Processo Alveolar/efeitos dos fármacos , Processo Alveolar/patologia , Animais , Anti-Inflamatórios/farmacologia , Densidade Óssea/efeitos dos fármacos , Cálcio/sangue , Contagem de Células , Dinoprostona/análise , Regulação para Baixo , Gengiva/efeitos dos fármacos , Gengiva/patologia , Interleucina-1beta/análise , Masculino , Mucosa Bucal/efeitos dos fármacos , Mucosa Bucal/patologia , Óxido Nítrico Sintase Tipo II/análise , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Fósforo/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
Physical growth retardation is an early and prominent feature of zinc deficiency, but the effect of zinc supplementation in children is still not completely clear. This study investigated the impact of zinc supplementation on linear growth, growth velocity, IGF-I levels, and skeletal maturation of short children during and after mineral supplementation. The study was designed as a double-blind, randomized, controlled trial of zinc supplementation during a 6-month period, with a subsequent 6-month follow-up. Anthropometric data were collected at 0, 6, and 12 months. Measurements included plasma Zn, IGF-I, height, weight, triceps skinfold thickness, and body mass index. Eighteen healthy pre-pubertal short children (z-score -2.0) 7 to 10 years old with normal GH and IGF-I levels were randomized to two groups, one with zinc supplementation (5 mg/kg/d of ZnSO4) and the other with placebo. In the first 6 months, only height velocity increased significantly, 5.99+/-0.80 cm/yr vs 5.05+/-0.85 cm/yr (p=0.03). After 12 months, height velocity returned to the initial values, 3.92+/-0.59 cm/yr vs 4.19+/-1.08 cm/yr (p=0.29). This study indicates that zinc supplementation increased growth velocity, but these effects did not persist after supplementation was discontinued.
Assuntos
Estatura/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Zinco/uso terapêutico , Criança , Método Duplo-Cego , Feminino , Gastroenteropatias/induzido quimicamente , Humanos , Masculino , Zinco/efeitos adversos , Zinco/sangueRESUMO
Astaxanthin is a diketo-dihydroxy-carotenoid produced by Phaffia rhodozyma, a basidiomicetous yeast. A low-cost fermentation medium consisting of raw sugarcane juice and urea was developed to exploit the active sucrolytic/urelolytic enzyme apparatus inherent to the yeast. As compared to the beneficial effect of 0.1 g% urea, a ready nitrogen source, mild phosphoric pre inversion of juice sucrose to glucose and fructose, promptly fermentable carbon sources, resulted in smaller benefits. Corn steep liquor (CSL) was found to be a valuable supplement for both yeast biomass yield (9.2 g dry cells/L) and astaxanthin production (1.3 mg/g cells). Distillery effluent (vinace), despite only a slightly positive effect on yeast growth, allowed for the highest pigment productivity (1.9 mg/g cells). Trace amounts of Ni2 (1 mg/L, as a cofactor for urease) resulted in controversial effects, namely, biomass decrease and astaxanthin increase, with no effect on the release (and uptake) of ammonium ion from urea. Since the synthesized astaxanthin is associated with the yeast cell and the pigment requires facilitated release for aquaculture uses (farmed fish meat staining), an investigation of the yeast cell wall was undertaken using detergent-treated cells. The composition of the rigid yeast envelope was found to be heterogeneous. Its partial acid or enzymatic depolymerization revealed glucose and xylose as common monomeric units of the cell-wall glycopolymers. Yeast cell-wall partial depolymerization with appropriate hydrolases may improve the pigment bioavailability for captive aquatic species and poultry.
RESUMO
Escherichia coli selenophosphate synthetase (SPS, the selD gene product) catalyzes the production of monoselenophosphate, the selenium donor compound required for synthesis of selenocysteine (Sec) and seleno-tRNAs. We report the molecular cloning of human and mouse homologs of the selD gene, designated Sps2, which contains an in-frame TGA codon at a site corresponding to the enzyme's putative active site. These sequences allow the identification of selD gene homologs in the genomes of the bacterium Haemophilus influenzae and the archaeon Methanococcus jannaschii, which had been previously misinterpreted due to their in-frame TGA codon. Sps2 mRNA levels are elevated in organs previously implicated in the synthesis of selenoproteins and in active sites of blood cell development. In addition, we show that Sps2 mRNA is up-regulated upon activation of T lymphocytes and have mapped the Sps2 gene to mouse chromosome 7. Using the mouse gene isolated from the hematopoietic cell line FDCPmixA4, we devised a construct for protein expression that results in the insertion of a FLAG tag sequence at the N terminus of the SPS2 protein. This strategy allowed us to document the readthrough of the in-frame TGA codon and the incorporation of 75Se into SPS2. These results suggest the existence of an autoregulatory mechanism involving the incorporation of Sec into SPS2 that might be relevant to blood cell biology. This mechanism is likely to have been present in ancient life forms and conserved in a variety of living organisms from all domains of life.
Assuntos
Archaea/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Drosophila , Escherichia coli/metabolismo , Fosfotransferases , Selenocisteína/metabolismo , Sequência de Aminoácidos , Animais , Archaea/genética , Proteínas de Bactérias/química , Sequência de Bases , Células COS , Mapeamento Cromossômico , Clonagem Molecular , Escherichia coli/genética , Feminino , Marcadores Genéticos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Selênio/metabolismo , Homologia de Sequência de Aminoácidos , TransfecçãoRESUMO
Over a two year period 174 evaluable episodes of fever in neutropenic patients were treated in a randomized study comparing four beta-lactam antibiotics, each given in combination with netilmicin. Exclusions included episodes due to viral or fungal infection, and trial violations. Most patients were receiving treatment for leukaemia, including 18% undergoing bone marrow transplantation. The overall response rate (EORTC criteria) was 66%, ranging from 56% for cefoperazone to 76% for mezlocillin. Microbial documentation was obtained in 31% of episodes; Gram-positive isolates were most frequent but Pseudomonas aeruginosa was found in 18 patients. In patients with microbiologically documented infection 70% improved, overall--from 40% with cefoperazone to 80% with piperacillin (P less than 0.05). Nephrotoxicity was seen in 6.7% and was associated with severe documented sepsis. Hypokalaemia was seen in 29% and was most marked in patients receiving ticarcillin. Rashes occurred in 6.6% overall, with no difference between the groups. Ototoxicity, shown by serial audiograms, was seen in 4.7% of patients. No evidence of vestibular dysfunction was seen in 62 patients studied. Of thirteen deaths due to the primary infection, seven were caused by Ps. aeruginosa and five by fungi.