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1.
J Med Case Rep ; 10: 160, 2016 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-27306557

RESUMO

BACKGROUND: Ectopic adrenocorticotropic hormone-producing primary liver tumors are rare, especially in children. We report the case of an adolescent boy of mixed Dutch and Moroccan descent with an adrenocorticotropic hormone-producing calcifying nested stromal-epithelial tumor with long-term follow-up. Thus far, only two such cases have been reported. CASE PRESENTATION: A 16-year-old boy of mixed Dutch and Moroccan descent presented with Cushing syndrome and a palpable abdominal mass. A calcifying nested stromal-epithelial tumor was diagnosed. Postoperatively, his plasma adrenocorticotropic hormone concentration normalized. He remains in complete remission 13 years after tumor resection. CONCLUSIONS: Calcifying nested stromal-epithelial tumor should be in the differential diagnosis of liver tumors, especially if associated with Cushing syndrome as significant morbidity and mortality may be associated. Literature on the topics involved is comprehensively reviewed.


Assuntos
Síndrome de Cushing/etiologia , Neoplasias Hepáticas/complicações , Adolescente , Hormônio Adrenocorticotrópico/sangue , Calcinose/complicações , Calcinose/diagnóstico , Síndrome de Cushing/sangue , Síndrome de Cushing/diagnóstico , Diagnóstico Diferencial , Epitélio/patologia , Humanos , Fígado/patologia , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/diagnóstico , Masculino , Marrocos , Países Baixos , Células Estromais/patologia
2.
Eur J Med Chem ; 68: 121-31, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23973824

RESUMO

Several novel 2,4-dinitrophenylhydrazone betulinic acid derivatives have been prepared by chemical and biotransformation methods using fungi and carrot cells. Some compounds showed significant cytotoxicity and selectivity against some tumor cell lines. The most active, 3-[(2,4-dinitrophenyl)hydrazono]lup-(20R)-29-oxolupan-28-oic acid, showed IC50 values between 1.76 and 2.51 µM against five human cancer cell lines. The most selective, 3-hydroxy-20-[(2,4-dinitrophenyl)hydrazono]-29-norlupan-28-oic acid, was five to seven times more selective for cancer cells when compared to fibroblasts. Cell cycle analysis and apoptosis induction were studied for the most active derivatives.


Assuntos
Hidrazonas/química , Hidrazonas/farmacologia , Triterpenos/química , Triterpenos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Citometria de Fluxo , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Triterpenos Pentacíclicos , Triterpenos/isolamento & purificação , Ácido Betulínico
3.
Rev. bras. farmacogn ; 23(2): 249-258, Mar.-Apr. 2013. ilus, graf
Artigo em Inglês | LILACS | ID: lil-669521

RESUMO

Melanin is a photoprotective skin pigment, and pathologies characterized by hypo or hyperpigmentation are common. New compounds that regulate melanogenesis are, therefore, opportune, and many natural products with this property, as polyphenols, have been described. Salvia officinalis L., Lamiaceae, is a widely used food spice that contains high amounts of phenol derivates, including rosmarinic acid. The aim of this work was to evaluate the contribution of rosmarinic acid in the melanogenic activity of sage extracts. Fluid and aqueous extracts of sage and purified rosmarinic acid were assayed for B16F10 cytotoxicity and, then, evaluated on melanin production and tyrosinase activity. While sage extracts showed a concentration-dependent ability to significantly increase melanin production without necessarily changing the enzymatic activity, rosmarinic acid showed a dual behavior on melanogenesis, increasing melanin biosynthesis and tyrosinase activity at low concentrations and decreasing it at higher levels. Rosmarinic acid may collaborate with sage extracts activity on melanogenesis, although other compounds may be involved. This is the first time that a dual action of rosmarinic acid on melanogenesis is reported, which may be useful in further studies for therapeutic formulations to treat skin pigmentation disorders.

4.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 7): o2008-9, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22807837

RESUMO

The title compound, C(16)H(14)Cl(2)O(2), is a chiral mitotane derivative that contains a dioxolane ring and crystallizes from methanol as a racemic mixture. It was obtained in high yield from mitotane and ethyl-eneglycol in alkaline medium, followed by neutralization with sulfuric acid and extraction with ethyl acetate. The mol-ecular structure is stabilized by an intra-molecular C- H⋯ O hydrogen bond. The dihedral angle between the aromatic rings is 80.1 (2)°. The dioxolane ring adopts a puckered envelope conformation with an O atom as the flap.

5.
Am J Cancer Res ; 1(2): 222-232, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21969107

RESUMO

Adrenocortical carcinoma is a rare endocrine malignancy with an estimated worldwide incidence of 0.5 - 2 per million/year. This neoplasm is characterized by a high risk of recurrence and a dismal prognosis owing to unsatisfactory overall survival. Surgery represents the cornerstone of adrenocortical carcinoma therapy, which can be associated to radiotherapy and adjuvant mitotane administration. In advanced cases, different chemotherapy regimens are used, but their relative efficacy is still unknown until the results of clinical trials under way will be published. Novel drugs have been recently developed based on the discovery of molecular pathways that trigger development and evolution of these tumors. More efficient treatments are widely expected in the future from these new targeted therapies as a hope of cure for patients affected with this aggressive malignancy.

6.
Eur J Neurosci ; 33(10): 1812-22, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21501257

RESUMO

Serotonin (5-HT) plays a critical role in locomotor pattern generation by modulating the rhythm and the coordinations. Pet-1, a transcription factor selectively expressed in the raphe nuclei, controls the differentiation of 5-HT neurons. Surprisingly, inactivation of Pet-1 (Pet-1(-/-) mice) that causes a 70% reduction in the number of 5-HT-positive neurons in the raphe does not impair locomotion in adult mice. The goal of the present study was to investigate the operation of the locomotor central pattern generator (CPG) in neonatal Pet-1(-/-) mice. We first confirmed, by means of immunohistochemistry, that there is a marked reduction of 5-HT innervation in the lumbar spinal cord of Pet-1(-/-) mice. Fictive locomotion was induced in the in vitro neonatal mouse spinal cord preparation by bath application of N-methyl-d,l-Aspartate (NMA) alone or together with dopamine and 5-HT. A locomotor pattern characterized by left-right and flexor-extensor alternations was observed in both conditions. Increasing the concentration of 5-HT from 0.5 to 5 µm impaired the pattern in Pet-1(-/-) mice. We tested the role of endogenous 5-HT in the NMA-induced fictive locomotion. Application of 5-HT(2) or 5-HT(7) receptor antagonists affected the NMA-induced fictive locomotion in both heterozygous and homozygous mice although the effects were weaker in the latter strain. This may be, at least partly, explained by the reduced expression of 5-HT(2A) R as observed by means of immunohistochemistry. These results suggest that compensatory mechanisms take place in Pet-1(-/-) mice that make locomotion less dependent upon 5-HT.


Assuntos
Locomoção/fisiologia , Camundongos Knockout , Neurônios/metabolismo , Serotonina/metabolismo , Fatores de Transcrição/metabolismo , Animais , Locomoção/efeitos dos fármacos , Vértebras Lombares , Camundongos , Neurônios/citologia , Periodicidade , Núcleos da Rafe/citologia , Núcleos da Rafe/metabolismo , Receptores de Serotonina/metabolismo , Receptores 5-HT2 de Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Medula Espinal/citologia , Medula Espinal/metabolismo , Fatores de Transcrição/genética
7.
Rev. bras. farmacogn ; 20(3): 403-408, jun.-jul. 2010. ilus, graf
Artigo em Inglês | LILACS | ID: lil-555922

RESUMO

The aim of this study was to determine whether eupafolin and hispidulin, flavones extracted from Eupatorium littorale Cabrera, Asteraceae, have the ability to change properties of biological membranes and promote cytotoxic effects. Eupafolin (50-200 µM) decreased approximately 30 percent the rate and total amplitude of valinomycin induced swelling and 60-100 percent the energy-dependent mitochondrial swelling. Moreover, eupafolin (200 µM) reduced 35 percent the mitochondrial permeability transition, and hispidulin did not change this parameter in any of the doses tested. The evaluation of phase transition of DMPC liposomes with the probe DPH demonstrated that hispidulin and eupafolin affect gel and fluid phase. With mitochondrial membrane as model, hispidulin increased the polarization of fluorescence when used DPH-PA probe. Eupafolin and hispidulin (100 µM) promoted a reduction of 40 percent in cellular viability of HeLa cells in 24 h. Our results suggest that eupafolin and hispidulin have cytotoxic effects that can be explained, in part, by alterations promoted on biological membranes properties and mitochondrial bioenergetics.


O objetivo deste estudo foi avaliar se eupafolina e hispidulina, flavonas extraídas do Eupatorium littorale Cabrera, Asteraceae, possuíam a capacidade de alterar propriedades das membranas biológicas e promover efeitos citotóxicos. Eupafolina (50-200 µM) reduziu em aproximadamente 30 por cento a velocidade e amplitude do inchamento mitocondrial induzido por valinomicina e 60-100 por cento o inchamento mitocondrial dependente de substrato. Além disso, eupafolina na dose de 200 µM reduziu a transição de permeabilidade mitocondrial em 35 por cento entretanto, a hispidulina não alterou este parâmetro em todas as doses testadas. A avaliação da transição de fase dos lipossomas de DMPC com a sonda DPH demonstrou que ambas as flavonas afetam a fase gel e fluida. Quando lipossomas de membranas mitocondriais e a sonda DPH-PA foram utilizados, houve aumento da polarização de fluorescência promovido pela hispidulina. Eupafolina e hispidulina, na dose de 100 µM, promoveram 40 por cento de redução da viabilidade de células HeLa em 24 h. Nossos resultados sugerem que eupafolina e hispidulina têm efeitos citotóxicos que podem ser explicados em parte pelas alterações promovidas por estas flavonas sobre propriedades de membranas biológicas e sobre a bioenergética mitocondrial.

8.
ECIPERU ; 7(1): 19-24, 2010. ilus
Artigo em Espanhol | LIPECS | ID: biblio-1107882

RESUMO

De los tallos de Cinchona pubescens que fueron colectados en la localidad de Yuracmallo (a 1 380 msnm, distrito de San Juan de Oro, Provincia de Sandia, Dpto. Puno) se aisló la quinina, que fue identificada mediante sus espectros de Masas, RMN1H, RMN13C y 1H-1H COSY. Además, se realizó el análisis cualitativo de sus metabolitos secundarios.


From the stems of the Cinchona pubescens, wich were collected in the locality Yuracmallo (Province of Sandia, Puno), quinine was obtained, wich was identified by the mass spectra, RMN1H, RMN13C and 1H-1H COSY. Furthermore, the qualitative analysis of the secondary metabolites was done.


Assuntos
Alcaloides , Alcaloides de Cinchona , Cinchona/química , Quinina
9.
Rev. bras. farmacogn ; 19(1a): 82-88, Jan.-Mar. 2009. ilus, graf
Artigo em Português | LILACS | ID: lil-522426

RESUMO

Annona glabra Linneau, Annonaceae, é uma árvore de pequeno porte encontrada em todo território brasileiro, principalmente nas áreas costeiras e conhecida popularmente como araticum-do-brejo e araticum-bravo. Este trabalho teve como objetivos investigar os efeitos do extrato de A. glabra e do ácido caurenóico dele purificado sobre a migração de granulócitos humanos e seu potencial imunomodulatório. Os resultados demonstraram que o extrato de A. glabra inibe a migração natural de granulócitos, de acordo com a dose, sugerindo potencial antiinflamatório, enquanto o ácido caurenóico demonstrou estimulá-la de forma significativa. Em contraste, nenhum efeito foi observado com relação a imunomodulação. Os efeitos apresentados ainda não foram descritos e, dessa forma, contribuem para ampliar a lista de atividades biológicas descritas não só do extrato de A. glabra, como também para o ácido caurenóico.


Annona glabra Linneau, Annonaceae, is a small tree that grows over the Brazilian territory particularly in its coast, and is known as "araticum-do-brejo" and "araticum-bravo". The aim of this study was to evaluate the effects of the extract of A. glabra and its purified kaurenoic acid on the locomotion of human granulocytes and their immunomodulatory potential. The results herein presented showed a dose-dependent inhibition of the granulocyte migration for the extract, suggesting an anti-inflammatory activity, in contrast with a striking stimulation observed for the kaurenoic acid. When focusing immunomodulation properties, no activity could be drawn. The effects presented in this work are reported for the first time and extend the list of biological activities already described for the A. glabra extract as well as for the kaurenoic acid.

10.
Bioorg Med Chem ; 16(2): 854-61, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17977731

RESUMO

This study evaluated the effects of flavone eupafolin (6-methoxy 5,7,3',4'-tetrahydroxyflavone), extracted from dry leaves of Eupatorium litoralle. Eupafolin (25-200microM) promoted inhibition of the respiratory rate in state 3, in the presence of glutamate or succinate. During succinate oxidation, it was found that only state 4 respiratory rate was stimulated approximately 30% by eupafolin (100microM) and ADP/O ratio and RCC were reduced with all doses. When glutamate was used as substrate, RCC was similarly reduced. Eupafolin caused a reduction of enzymatic activities between complexes I and III of the respiratory chain. Cytochrome c oxidase and ATPase activities were not affected. Using voltammetry cyclic analysis, eupafolin give rise to irreversible oxidation with an anodic peak potential at +0.08V (SHE). We also observed that eupafolin can undergo oxidation catalyzed by EDTA-Fe, promoting cytochrome c reduction in the presence of NADH, resulting in the production of the superoxide radical and hydrogen peroxide. All together, the results could explain the cytotoxic effects observed previously with the eupafolin.


Assuntos
Respiração Celular/efeitos dos fármacos , Flavonas/farmacologia , Mitocôndrias/efeitos dos fármacos , Adenosina Trifosfatases/efeitos dos fármacos , Complexo IV da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Flavonas/química , Flavonas/isolamento & purificação , Flavonas/toxicidade , Ácido Glutâmico/metabolismo , Mitocôndrias/metabolismo , Estrutura Molecular , Oxirredução , Relação Estrutura-Atividade
11.
J Biotechnol ; 131(1): 92-6, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17624458

RESUMO

Stevioside is a natural sweetener obtained from the leaves of Stevia rebaudiana. It is a glycoside of steviol and other glycosides of the same aglycone are also found in the plant. Stevioside is usually the major component in commercial products, but it is not the one with the best organoleptic properties. It has a bitter aftertaste and, for this reason, attempts have been made in order to modify its molecule. In this work, the commercial and purified stevioside were modified by hydrolytic enzymes from Gibberella fujikuroi. A screening was carried out on six strains of the fungus in order to select the most active. The production of the enzymes by the fungi was induced by its culture in a medium containing stevioside as the sole carbon source and the enzymatic extract was then used in the experiments. The products obtained were analyzed by HPLC-UV and HPLC-MS/MS. The results showed a significant increase in the concentration of rebaudioside A in the final product, which has better organoleptic properties than stevioside.


Assuntos
Diterpenos do Tipo Caurano/metabolismo , Gibberella/enzimologia , Glucosídeos/metabolismo , Catálise , Sistema Livre de Células , Cromatografia Líquida de Alta Pressão , Diterpenos do Tipo Caurano/química , Diterpenos do Tipo Caurano/isolamento & purificação , Glucosídeos/química , Glucosídeos/isolamento & purificação , Hidrólise , Cinética , Espectrometria de Massas
12.
Phytochemistry ; 68(6): 834-9, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17258248

RESUMO

Betulinic acid (1), a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. The closely related, betulonic acid (2) also has similar properties. In order to obtain derivatives potentially useful for detailed pharmacological studies, both compounds were submitted to incubations with selected microorganisms. In this work, both were individually metabolized by the fungi Arthrobotrys, Chaetophoma and Dematium, isolated from the bark of Platanus orientalis as well as with Colletotrichum, obtained from corn leaves; such fungal transformations are quite rare in the scientific literature. Biotransformations with Arthrobotrys converted betulonic acid (2) into 3-oxo-7beta-hydroxylup-20(29)-en-28-oic acid (3), 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4) and 3-oxo-7beta,30-dihydroxylup-20(29)-en-28-oic acid (5); Colletotrichum converted betulinic acid (1) into 3-oxo-15alpha-hydroxylup-20(29)-en-28-oic (6) acid whereas betulonic acid (2) was converted into the same product and 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4); Chaetophoma converted betulonic acid (2) into 3-oxo-25-hydroxylup-20(29)-en-28-oic acid (7) and both Chaetophoma and Dematium converted betulinic acid (1) into betulonic acid (2). Those fungi, therefore, are useful for mild, selective oxidations of lupane substrates at positions C-3, C-7, C-15, C-25 and C-30.


Assuntos
Fungos/metabolismo , Ácido Oleanólico/análogos & derivados , Triterpenos/metabolismo , Ascomicetos/metabolismo , Biotransformação , Colletotrichum/metabolismo , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/metabolismo , Triterpenos Pentacíclicos , Triterpenos/química , Ácido Betulínico
13.
J Pediatr Hematol Oncol ; 28(8): 513-24, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16912591

RESUMO

PURPOSE: To define a mitotane dose for pediatric patients with adrenocortical cancer (ACC) that maintains therapeutic plasma levels (TL) between 14 and 20 microg/mL and to verify its antitumor efficacy in association with 8 cycles of cisplatin, etoposide, and doxorubicin (CED). METHODS: Powdered mitotane was dissolved in a medium chain triglyceride oil and administered to 11 children with ACC (2.4 to 15.4 y of age); an initial low dose was increased to 4 g/m2/d. Ten of the 11 children had a germline TP53 R337H mutation. Mitotane plasma levels were determined using high-performance liquid chromatography. RESULTS: The mitotane dose to maintain TL in 7 patients ranged from 1.0 to 5.3 g/m2/d. Six children reached mitotane levels of 10 microg/mL in 3.6 months (1.5 to 5.0 mo), whereas 5 children took 8 months (6.5 to 12.5 mo). Minor to partial tumor remission was found in 5 patients (<1 y) and complete remission was found in 2 patients. Of the 3 patients who are alive at the time of report, 1 patient has been without disease for 16 months, and 2 patients have progressive disease. All patients had recurrent metastatic disease (2 to 9 times). Mitotane toxic effects were nausea, diarrhea, vomiting, neurologic alterations, gynecomastia, a rare case of hypertensive encephalopathy, and CED-related hematologic toxic effects. CONCLUSIONS: Mitotane daily dose to maintain TL is variable and monitoring should start 1.5 months after the beginning of treatment. CED combined with mitotane is the best available pharmacologic treatment for ACC, but further studies are required to characterize different profiles of therapeutic response.


Assuntos
Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/administração & dosagem , Doxorrubicina/administração & dosagem , Etoposídeo/administração & dosagem , Mitotano/administração & dosagem , Administração Oral , Neoplasias do Córtex Suprarrenal/diagnóstico , Neoplasias do Córtex Suprarrenal/cirurgia , Carcinoma Adrenocortical/diagnóstico , Carcinoma Adrenocortical/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criança , Pré-Escolar , Cisplatino/efeitos adversos , Progressão da Doença , Relação Dose-Resposta a Droga , Doxorrubicina/efeitos adversos , Esquema de Medicação , Monitoramento de Medicamentos/métodos , Quimioterapia Combinada , Etoposídeo/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Mitotano/efeitos adversos , Estadiamento de Neoplasias , Estudos Prospectivos , Indução de Remissão , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
14.
Toxicol Lett ; 143(1): 83-92, 2003 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-12697384

RESUMO

Isosteviol lactone (LAC), a lactone derivative of the diterpenic acid isosteviol (ISO) was evaluated for its effect on the oxidative metabolism of mitochondria isolated from rat liver. In this model, LAC (1 mM) depressed the phosphorylation efficiency, as shown by the decreased respiratory control coefficient (RCC) and ADP/O ratio. LAC (1 mM) inhibited NADH oxidase (45%), succinate oxidase (34%) and promoted low-level inhibitions on succinate dehydrogenase (13%), succinate-cytochrome c oxide-reductase (23%), cytochrome c oxidase (10%), and NADH dehydrogenase (13%). Glutamate dehydrogenase was also a target for LAC, as it was 85% inhibited by 1 mM LAC. Cyclic voltammetry data showed that LAC, as well as ISO, does not undergo redox reactions under current experimental conditions. LAC (0.05-0.75 mM) inhibited the swelling dependent on the glutamate oxidation, 50% of the effect occurring at 0.5 mM LAC. Swelling supported by KNO(3) and valinomycin was also inhibited over all concentrations used of LAC and ISO, the effect being of a lower intensity for LAC, suggesting that the modification of the structure of ISO by lactonization diminished its interaction with the membrane. This could contribute to attenuation of the toxic effects described for ISO on mitochondrial function, such as those on respiratory chain enzymatic complexes and phosphorylating activity.


Assuntos
Diterpenos do Tipo Caurano , Diterpenos/farmacologia , Lactonas/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Animais , Diterpenos/síntese química , Diterpenos/química , Eletroquímica , Transporte de Elétrons/efeitos dos fármacos , Eletrofisiologia , Hidrólise , Técnicas In Vitro , Cetonas/química , Lactonas/química , Masculino , Mitocôndrias Hepáticas/enzimologia , Dilatação Mitocondrial/efeitos dos fármacos , Oxirredução , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Proteínas/metabolismo , Ratos , Ratos Wistar , Stevia/química , Relação Estrutura-Atividade
15.
Phytochem Anal ; 13(6): 368-71, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12494758

RESUMO

The isolation of ent-kaur-16-en-19-oic acid (1) from the leaves and bark of Annona glabra and its determination by reversed-phase HPLC with a photodiode array detector is described. The results indicate that 1 accumulates in the bark of the plant with only very low concentrations in the leaves. Levels of 1 varied throughout the year being highest for bark and leaves in the autumn (5.29 +/- 0.23 and 0.27 +/- 0.01 mg/g dry weight, respectively) and lowest in the spring for bark and in the winter for leaves (4.00 +/- 0.25 and 0.11 +/- 0.01 mg/g dry weight, respectively).


Assuntos
Annona/química , Diterpenos do Tipo Caurano , Diterpenos/química , Cromatografia Líquida de Alta Pressão/métodos , Diterpenos/isolamento & purificação , Estrutura Molecular , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Estações do Ano
16.
Appl Biochem Biotechnol ; 102-103(1-6): 179-91, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12396121

RESUMO

Five strains of Gibberella fujikuroi and one of Fusarium moniliforme were screened for the production of gibberellic acid (GA3) in coffee husk, and based on the results, one strain, G. fujikuroi LPB-06, was selected. The comparative production of GA3 by solid-state fermentation and submerged fermentation indicated better productivity with the former technique, mainly with pretreated substrate. The GA3 accumulation was 6.1 times higher in the case of solid-state fermentation. Considering the C:N relation, higher yields of GA3 were achieved using a mixed substrate comprising coffee husk and cassava bagasse (7:3, dry wt), increasing the results twice. Supplementation of an optimized saline solution containing 0.03% FeSO4 and 0.01% (NH4)2SO4 enhanced the accumulation of GA3 1.7 times in the fermented substrate. Under the finally optimized condition, the culture gave a maximum of 492.5 mg of GA3/kg of dry substrate, with a pH of 5.3, moisture of 75%, and incubation temperature of 29 degrees C. GA3 yield was almost 13 times more than the initial results.


Assuntos
Café/metabolismo , Fusarium/metabolismo , Gibberella/metabolismo , Giberelinas/biossíntese , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Café/química , Café/microbiologia , Fermentação , Concentração de Íons de Hidrogênio , Cinética , Manihot/metabolismo , Sais/química , Sais/farmacologia , Soluções , Temperatura , Água/análise
17.
Pharmacol Biochem Behav ; 72(4): 779-86, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12062566

RESUMO

The alkaloid ricinine isolated from the plant Ricinus communis, when administered to mice at high doses, induces clonic seizures accompanied by electroencephalographic alterations in the cerebral cortex and hippocampus. The lethal nature of ricinine-induced seizures is considered to be a good model for the study of the events that cause death during clonic seizures, particularly those related to respiratory spasms. The initial signs (pre-seizure period) were marked by exophthalmus and decreased locomotor behavior. Animals killed during the preseizure period presented an increased utilization rate (HVA/DA) of dopamine (DA), an increased concentration of noradrenaline (NA), and a decreased concentration of glutamate (Glu), glutamine (Gln), taurine (Tau), and serotonin (5-HT) in the cerebral cortex. The seizure period is characterized by the occurrence of hind limb myoclonus and respiratory spasms, which are followed by death. Alterations in the cerebral cortex concentration of these neurotransmitters persisted during the seizure period. These alterations are only partially observed in the hippocampus, mainly during the seizure period. The present results suggest that an increased release of Glu in the cerebral cortex can be implicated in the genesis of the ricinine-induced seizure and that it triggers many anticonvulsive mechanisms, like the release of Tau, DA, 5-HT, and NA.


Assuntos
Alcaloides/toxicidade , Aminoácidos/metabolismo , Monoaminas Biogênicas/metabolismo , Córtex Cerebral/metabolismo , Piridonas , Convulsões/induzido quimicamente , Convulsões/metabolismo , Animais , Córtex Cerebral/efeitos dos fármacos , Dopamina/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Norepinefrina/metabolismo
18.
Phytochem Anal ; 13(2): 95-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12018029

RESUMO

The isolation, detection and quantification of betulinic acid in Doliocarpus schottianus are described. The isolation from the plant extract was made by column chromatography and centrifugal TLC, and betulinic acid was characterized by spectrometric methods. The detection and quantification were made by HPLC using a C18 column eluted with acetonitrile: water and detected at 210 nm. The results showed that the metabolite accumulates in the bark of the plant, but very small concentrations were also found in the leaves and wood.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Plantas/química , Triterpenos/análise , Calibragem , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Triterpenos Pentacíclicos , Espectrofotometria Infravermelho , Triterpenos/química , Triterpenos/isolamento & purificação , Ácido Betulínico
19.
J Physiol Paris ; 93(4): 285-96, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10574118

RESUMO

Synaptic plasticity is usually considered as the main form of activity-dependent functional plasticity in the mammalian brain. Short- and long-term regulation of synaptic transmission have been shown in various types of excitatory synapses including cortical and hippocampal synapses. In this review, we discuss a novel form of non-synaptic plasticity that involves voltage-gated K+ conductances in CA3 pyramidal cell axons. With experimental and theoretical arguments, we show that axons cannot only be considered as a simple structure that transmit reliably the action potential (AP) from the cell body to the nerve terminals. The axon is also able to express conduction failures in specific axonal pathways. We discuss possible physiological conditions in which these axonal plasticity may occur and its incidence on hippocampal network properties.


Assuntos
Potenciais de Ação/fisiologia , Axônios/fisiologia , Hipocampo/fisiologia , Ativação do Canal Iônico/fisiologia , Condução Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Canais de Potássio/fisiologia , Animais , Humanos , Modelos Neurológicos
20.
Neurosci Res ; 27(2): 143-53, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9100256

RESUMO

The aim of the present study was to provide a quantitative analysis of the synapses made onto the axon hillock and initial segment of rat abducens motoneurons retrogradely or intracellularly stained with HRP. GABA-immunoreactive terminals contacting these axons were visualized using a postembedding procedure. The presynaptic terminals contained either spherical or pleomorphic vesicles. gamma-Aminobutyric acid (GABA)-immunoreactive axon terminals, which belonged to this last category, were distributed both onto axon hillocks and the proximal part of initial segments. The percentage of axonal membrane covered by synapses ranged from 44.1 to 68.2%. A quantitative analysis performed on a series of ultrathin sectioned terminals contacting the axon of an intracellularly labeled motoneuron revealed a significant correlation between the length of membrane apposition of the terminals and their perimeter or surface area, and also between the area of membrane apposition and terminal volume. GABA-immunoreactive terminals had a mean perimeter and volume that were larger than those of unlabeled axon terminals. The number of active zones was correlated with the area of apposition. Some hypotheses concerning the functional role of the GABAergic innervation of this particular part of the neuron are discussed.


Assuntos
Nervo Abducente/fisiologia , Axônios/fisiologia , Neurônios Motores/fisiologia , Terminações Pré-Sinápticas/fisiologia , Ácido gama-Aminobutírico/fisiologia , Nervo Abducente/citologia , Nervo Abducente/ultraestrutura , Animais , Axônios/ultraestrutura , Peroxidase do Rábano Silvestre , Imuno-Histoquímica , Microscopia Eletrônica , Neurônios Motores/ultraestrutura , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Wistar , Sinapses/fisiologia , Sinapses/ultraestrutura
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