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1.
Anaesth Rep ; 10(1): e12167, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35572618

RESUMO

Anaphylactic reactions during the induction of general anaesthesia are rare. Anaesthetists should determine the pathogenesis of anaphylaxis in order to establish appropriate treatment and prevent recurrence. Very little clinical information has been published to date about anaphylaxis induced by the recently launched drug remimazolam. A 78-year-old man, scheduled for elective surgery for colon cancer, became profoundly hypotensive and hypoxic shortly following the induction of general anaesthesia with remimazolam, remifentanil and rocuronium. His physiological derangement was successfully managed with adrenaline, vasopressors and intravenous fluid resuscitation. His serum tryptase level was significantly elevated and an intradermal test with diluted remimazolam revealed a positive reaction, confirming the diagnosis of anaphylaxis. We believe this is the first case report of remimazolam-induced anaphylactic shock diagnosed with a serum tryptase elevation and positive skin test.

2.
Nutr Diabetes ; 3: e79, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23797386

RESUMO

BACKGROUND: Obesity has become an epidemic in many countries and is supporting a billion dollar industry involved in promoting weight loss through diet, exercise and surgical procedures. Because of difficulties in maintaining body weight reduction, a pattern of weight cycling often occurs (so called 'yo-yo' dieting) that may result in deleterious outcomes to health. There is controversy about cardiovascular benefits of yo-yo dieting, and an animal model is needed to better understand the contributions of major diet and body weight changes on heart and vascular functions. Our purpose is to determine the effects of weight cycling on cardiac function and atherosclerosis development in a mouse model. METHODS: We used low-density lipoprotein receptor-deficient mice due to their sensitivity to metabolic syndrome and cardiovascular diseases when fed high-fat diets. Alternating ad libitum feeding of high-fat and low-fat (rodent chow) diets was used to instigate weight cycling during a 29-week period. Glucose tolerance and insulin sensitivity tests were done at 22 and 24 weeks, echocardiograms at 25 weeks and atherosclerosis and plasma lipoproteins assessed at 29 weeks. RESULTS: Mice subjected to weight cycling showed improvements in glucose homeostasis during the weight loss cycle. Weight-cycled mice showed a reduction in the severity of atherosclerosis as compared with high-fat diet-fed mice. However, atherosclerosis still persisted in weight-cycled mice as compared with mice fed rodent chow. Cardiac function was impaired in weight-cycled mice and matched with that of mice fed only the high-fat diet. CONCLUSION: This model provides an initial structure in which to begin detailed studies of diet, calorie restriction and surgical modifications on energy balance and metabolic diseases. This model also shows differential effects of yo-yo dieting on metabolic syndrome and cardiovascular diseases.

3.
Clin Nephrol ; 73(2): 163-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20129025

RESUMO

Perinephric abscesses in patients on maintenance hemodialysis (HD) have seldom been reported. The case of a maintenance HD patient with a left perinephric abscess is reported. Although the lesion could not be visualized using other imaging examinations, using FDG and positron emission tomography combined with computed tomography (PET-CT), the patient was diagnosed as having a left perinephric abscess and nephrolithiasis. At the patient's request, the perinephric abscess was treated conservatively with antibiotic therapy alone, and it eventually remitted. This is the first case report of a perinephric abscess diagnosed by FDG PET-CT in a patient on maintenance HD. FDG PET-CT appears to be useful for identifying perinephric abscesses in HD patients, resulting in early diagnosis and appropriate therapy for this severe infection.


Assuntos
Abscesso/diagnóstico , Rim , Tomografia por Emissão de Pósitrons/métodos , Diálise Renal/métodos , Tomografia Computadorizada por Raios X/métodos , Infecções Urinárias/diagnóstico , Abscesso/terapia , Adulto , Diagnóstico Diferencial , Humanos , Masculino , Infecções Urinárias/terapia
4.
Plant Sci ; 160(4): 577-583, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11448732

RESUMO

Two rice cDNAs, EL5 and RRF1, were isolated and characterized. EL5 was responsive to N-acetylchitooligosaccharide, a biotic elicitor active in suspension-cultured rice cells. The structural specificity of the elicitor required for the expression of EL5 was consistent with other defense reactions observed in the experimental system, indicating that the elicitor signal to EL5 is transmitted through a single class of receptor-mediated recognition events. However, the intracellular signaling pathway to EL5 was distinct from those to other elicitor-responsive genes. Sequence analysis and alignment showed that a genomic sequence stored in rice genome databases in addition to EL5 and RRF1 belongs to the ATL family of RING-H2 finger motif proteins first isolated from Arabidopsis.

5.
Bioorg Med Chem ; 9(7): 1781-91, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11425580

RESUMO

Plaunotol, a known antiulcer drug, has antibacterial activities against Helicobacter pylori. Plaunotol thiourea derivatives 2--4 and diol derivatives 6--10 were designed in search for a compound with high antibacterial activities. Thiourea derivatives 2--4 were synthesized regioselectively using our effective synthetic route for plaunotol (1), and diol derivatives 6--10 were also synthesized. Their antibacterial activities against H. pylori are described and we found that the most potent antibacterial agent was C1-thiourea derivative 2c.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Álcoois Graxos/química , Helicobacter pylori/efeitos dos fármacos , Diterpenos , Álcoois Graxos/síntese química , Álcoois Graxos/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Espectrometria de Massas de Bombardeamento Rápido de Átomos
6.
Inflamm Res ; 49(10): 553-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11089909

RESUMO

OBJECTIVE AND DESIGN: We previously reported that oral l-ephedrine showed extraordinarily rapid inhibition of 48-h passive cutaneous anaphylaxis (PCA) in rats. In the present study, in vivo and in vitro experiments were performed to elucidate a possible mechanism for the inhibition. MATERIALS: Rat antiserum was prepared with dinitrophenylated Ascaris suum extract + Bordetella pertussis. TREATMENT: Wistar rats were passively skin-sensitised, actively sensitised or non-sensitised. l-Ephedrine immediately before provocations was orally or intravenously administered in in vivo experiments. In in vitro experiments, the drug was added at various time and concentrations before the challenge. METHODS: The intensity of PCA was assessed by dye leakage method. Histamine and serotonin released in vitro or retained in the skin in vivo by anaphylaxis were assayed fluorometrically. RESULTS: Oral l-ephedrine rapidly inhibited the PCA by inhibiting the release of histamine and serotonin from the reaction site, whereas anaphylactic histamine and serotonin releases from skin fragments were not affected by the drug. Furthermore, the orally administered drug influenced neither the histamine- nor serotonin-induced cutaneous vascular permeability. CONCLUSIONS: These results were strongly indicative that the prompt suppression of the PCA by oral l-ephedrine was not exerted following the drug was absorbed from the gastrointestinal tract. Thus, the result may be from an indirect inhibition of chemical mediator release, possibly through an unidentified stimulation of the nervous system, but not from the inhibition of chemical mediator release by the direct interaction of drug to mast cells and not from the decreased vascular permeability.


Assuntos
Efedrina/farmacologia , Liberação de Histamina/efeitos dos fármacos , Mastócitos/efeitos dos fármacos , Anafilaxia Cutânea Passiva/efeitos dos fármacos , Serotonina/metabolismo , Administração Oral , Animais , Permeabilidade Capilar/efeitos dos fármacos , Histamina/análise , Masculino , Mastócitos/metabolismo , Ratos , Ratos Wistar , Serotonina/análise
7.
Phytomedicine ; 7(1): 69-72, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10782493

RESUMO

This study measured the effects of Shitei-To (STT), a traditional Chinese Medicine, which is a mixture of extracts from three medicinal herbs, Shitei (SI, Kaki Calyx; calyx of Diospyros kaki L. f.), Shokyo (SK, Zingiberis Rhizoma; rhizome of Zingiber officinale Roscoe) and Choji (CJ, Caryophylli flos; flowerbud of Syzygium aromaticum [L.] Merrill et. Perry), has long been used for the treatment of hiccups in Japan and China, against fully pentylenetetrazol-kindled seizures and on the development of pentylenetetrazol kindling in mice. Repeated administration of STT (3.0 g/kg p.o.) mildly retards the development of pentylenetetrazol-induced kindling in mice. STT also decreased the number of tonic-clonic convulsions resulting from progression kindling. On the other hand, STT had no effect on convulsions in fully pentylenetetrazol-kindled mice. These findings suggest that STT protects against the development of convulsions, and that STT may have therapeutic effects in the prevention of secondarily generalized seizures.


Assuntos
Anticonvulsivantes/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Excitação Neurológica/efeitos dos fármacos , Animais , Convulsivantes , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos , Pentilenotetrazol , Convulsões/prevenção & controle
8.
Chem Pharm Bull (Tokyo) ; 48(3): 389-92, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10726863

RESUMO

Naturally occurring phenylpropanoids, hinokiresinol (trans-hinokiresinol) and nyasol (cis-hinokiresinol) were found to possess appreciable estrogen receptor binding activity. Strong differences in activity were observed between the geometrical isomers and enantiomers. Among these, (3S)-cis-hinokiresinol displayed the highest activity, one order of magnitude greater than the activity of genistein. Furthermore, cis- and trans-hinokiresinol stimulated the proliferation of estrogen-dependent T47D breast cancer cells, and their stimulatory effects were blocked by an estrogen antagonist, indicating that the compounds are estrogen agonists. In addition, the absolute configuration of C-3 in (+)-cis-hinokiresinol has been assigned as S by comparison with the circular dichroism spectra of the hydrogenated products prepared from cis and trans ((3S)-trans-hinokiresinol: previously assigned) isomers. These results incidentally provide us with an unambiguous answer to contradictory reports regarding the assignment of the full stereochemisry of cis- and trans-hinokiresinol that have existed in the literature for more than two decades.


Assuntos
Estrogênios não Esteroides/química , Estrogênios não Esteroides/farmacologia , Isoflavonas , Lignanas , Fenóis/química , Fenóis/farmacologia , Animais , Bovinos , Divisão Celular/efeitos dos fármacos , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Feminino , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Fitoestrógenos , Preparações de Plantas , Plantas Medicinais/química , Alcamidas Poli-Insaturadas , Estereoisomerismo , Células Tumorais Cultivadas , Útero/efeitos dos fármacos , Útero/metabolismo
9.
Inflamm Res ; 49(12): 714-9, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11211923

RESUMO

OBJECTIVE AND DESIGN: We previously demonstrated that oral l-ephedrine exerts an extremely rapid (within 20 s) inhibition of 48-h passive cutaneous anaphylaxis reaction (PCA) in rats by a possibly unidentified mode of action. In the present experiments, we elucidated the mechanism of the PCA inhibition by l-ephedrine using adrenoceptor agonists and antagonists. MATERIALS: Rat antiserum was prepared with dinitrophenylated Ascaris suum extract + Bordetella pertussis. TREATMENT: Passively skin-sensitised Wistar rats were mainly used. l-Ephedrine, and adrenoceptor agonists and antagonists were orally administered immediately before PCA provocation. Catecholamine depleting (6-hydroxydopamine, 6-OHDA), amine depleting (reserpine) or ganglion blocking (hexamethonium) agent was intraperitoneally or intravenously administered before the provocation. METHODS: The effects of the drugs on PCA were assessed by inhibition of the dye leakage. RESULTS: beta-(propranolol) and beta2-(butoxamine) blocking agents reduced the inhibition of PCA by l-ephedrine, while the inhibition was not altered by either an a-blocking agent (phentolamine) or a beta1-(atenolol) selective antagonist. On the other hand, beta-(isoproterenol) and beta2-selective (salbutamol) agonists showed extremely rapid inhibition of PCA. However, the beta-selective agonist (dobutamine) had no effect on the reaction. The pretreatment with hexamethonium, reserpine or 6-OH-DA substantially attenuated the inhibitory effect of l-ephedrine on PCA. CONCLUSIONS: The results strongly suggest that beta2-adrenoceptors locate in the stomach and that their receptor excitement finally may lead to the inhibition of PCA via the stimulation of the central and peripheral nervous systems.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Agonistas Adrenérgicos beta/farmacologia , Neurônios Aferentes/efeitos dos fármacos , Neurônios Eferentes/efeitos dos fármacos , Anafilaxia Cutânea Passiva/efeitos dos fármacos , Estômago/efeitos dos fármacos , Estômago/inervação , Animais , Permeabilidade Capilar/efeitos dos fármacos , Dopaminérgicos/farmacologia , Efedrina/farmacologia , Compostos de Hexametônio/farmacologia , Isoproterenol/farmacologia , Masculino , Ratos , Ratos Wistar
10.
Theor Popul Biol ; 56(1): 123-37, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10438673

RESUMO

We consider systems with one predator and one prey, or a common predator and two prey species (apparent competitors) in source and sink habitats. In both models, the predator species is vulnerable to extinction, if productivity in the source is insufficient to rescue demographically deficient sink populations. Conversely, in the model with two prey species, if the source is too rich, one of the prey species may be driven extinct by apparent competition, since the predator can maintain a large population because of the alternative prey. Increasing the rate of predator movement from the source population has opposite effects on prey and predator persistence. High emigration rate exposes the predator population to danger of extinction, reducing the number of individuals that breed and produce offspring in the source habitat. This may promote coexistence of prey by relaxing predation pressure and apparent competition between the two prey species. The number of sinks and spatial arrangement of patches, or connectivity between patches, also influence persistence of the species. More sinks favor the prey and fewer sinks are advantageous to the predator. A linear pattern with the source at one end is profitable for the predator, and a centrifugal pattern in which the source is surrounded by sinks is advantageous to the prey. When the dispersal rate is low, effects of the spatial structure may exceed those of the number of sinks. In brief, productivity in patches and patterns of connectivity between patches differentially influence persistence of populations in different trophic levels.


Assuntos
Comportamento Competitivo/fisiologia , Ecossistema , Emigração e Imigração , Comportamento Alimentar/fisiologia , Modelos Estatísticos , Densidade Demográfica , Dinâmica Populacional , Comportamento Predatório/fisiologia , Animais , Reprodutibilidade dos Testes
11.
Am J Chin Med ; 27(1): 107-15, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10354822

RESUMO

The anticonvulsant effects of Shitei-To and its components on maximal electroshock seizures and chemical convulsions were examined. Shitei-To significantly prolonged the latency to bicuculline (2.0 mg/kg, s.c.)-induced clonic convulsions. Repeated treatment with Shitei-To also significantly prolonged the latency to strychnine (1.5 mg/kg, i.p.)- and pentylenetetrazol (90 mg/kg, i.p.)-induced clonic convulsions. On the other hand, Shitei-To had no effect on maximal electroshock seizures. Of the components of Shitei-To, Shitei had almost the same effect as Shitei-To against the clonic convulsions induced by the three chemical agents tested. These findings suggest that Shitei-To has anticonvulsant effects.


Assuntos
Anticonvulsivantes/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Convulsões/tratamento farmacológico , Animais , Bicuculina , Convulsivantes , Eletrochoque , Masculino , Camundongos , Camundongos Endogâmicos , Pentilenotetrazol , Convulsões/induzido quimicamente , Estricnina
12.
Bioorg Med Chem Lett ; 9(10): 1347-50, 1999 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-10360733

RESUMO

Practical and highly stereoselective synthesis of diterpene alcohol, plaunotol (1) and its thiourea derivatives 2a, 3a and 4a, via Z-selective Wittig reaction between alpha-acetal ketone 5 and phosphonium salt 6 and their antibacterial activity against Helicobacter pylori are described.


Assuntos
Antibacterianos/síntese química , Álcoois Graxos/síntese química , Helicobacter pylori/efeitos dos fármacos , Tioureia/química , Antibacterianos/química , Antibacterianos/farmacologia , Diterpenos , Álcoois Graxos/química , Álcoois Graxos/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular
13.
Plant Mol Biol ; 39(5): 907-14, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10344196

RESUMO

Expression patterns of chitinase transcripts induced by N-acetylchitooligosaccharide elicitor were analyzed by northern blot hybridization in order to reveal a signal transduction pathway leading to the activation of class I chitinase genes (Cht-1 and Cht-3), which may play an important role in producing N-acetylchitooligosaccharide elicitor. The transcription level of both genes was enhanced in response to N-acetylchitooligosaccharides larger than pentaose at subnanomolar concentrations. These structure and dose dependencies were consistent not only with those for a 75 kDa high-affinity binding protein for N-acetylchitooligosaccharide elicitor in the plasma membrane, but also with other series of cellular responses including phytoalexin production and the expression of elicitor-responsive genes (EL2, EL3). Therefore, the elicitor signal to evoke these cellular responses including the activation of the chitinase genes could be common and transmitted into cells through the 75 kDa protein. However, the signal transduction pathway for the activation of the chitinase gene appeared to diverge from those for the other elicitor-responsive genes shortly after the signal perception. It was shown that the induction of chitinase expression by N-acetylchitooligosaccharide would require protein phosphorylation, but not de novo protein synthesis. The oxidative burst was demonstrated not to be necessary for transcriptional induction of the all four elicitor-responsive genes (Cht, PAL, EL2, EL3) by N-acetylchitooligosaccharide.


Assuntos
Quitinases/genética , Oligossacarídeos/farmacologia , Oryza/efeitos dos fármacos , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Antracenos/farmacologia , Células Cultivadas , Quitina/farmacologia , Canais de Cloreto/antagonistas & inibidores , Cicloeximida/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Cinética , NADPH Oxidases/antagonistas & inibidores , Oligossacarídeos/química , Oniocompostos/farmacologia , Oryza/enzimologia , Oryza/genética , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
16.
Rev. Assoc. Med. Bras. (1992) ; 43(3): 185-8, jul.-set. 1997. ilus
Artigo em Português | LILACS | ID: lil-201481

RESUMO

O autores descrevem as características anatómicas do músculo levantador do lábio superior por meio de dissecaçöes em cadáveres. Objetivo. Contribuir ao estudo dos músculos da mímica, estudando os seus detalhes anatómicos e suas relaçöes, ajudando na realizaçäo de retalhos da face. Métodos. Foram dissecadas 20 peças de cadáveres, verificando-se suas inserçöes, comprimento, largura, espessura, relaçöes, inervaçäo e irrigaçäo. Resultados. Em todos os casos, o músculo levantador do lábio superior apresentou inserçäo proximal na margem inferior da órbita e inserçäo distal de dois tipos: por meio de fibras laterais sobrepondo-se superficialmente ao músculo orbicular do lábio e de fibras profundas interdigitando-se, formando parte do embricamento do canto da boca (70 por cento); e mediante fibras sobrepondo-se superficialmente ao músculo orbicular do lábio (30 por cento). A média do comprimento foi de 24,66mm e a média da espessura, de 3,57mm. A largura em nível da inserçäo distal foi, em média, de 11,2mm, enquanto que em nível da inserçäo proximal foi, em média, de 15,96mm. Relaciona-se anteriormente ao músculo levantador do ângulo da boca, posteriormente à porçäo distal do músculo zigomático menos (90 por cento) e posteriormente à porçäo media do músculo zigomático menor (10 por cento). A inervaçäo é feita pelo ramo inferior do nervo zigomático (n. facial) e nervo infra-orbital (n. trigêmeo). Ramos da artéria angular irrigam a porçäo inferior do músculo e a artéria infra-orbital nutre a porçäo superior deste músculo.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Músculos Faciais/anatomia & histologia , Lábio , Cadáver , Músculos Faciais/irrigação sanguínea , Músculos Faciais/inervação
17.
Rev Assoc Med Bras (1992) ; 43(3): 185-8, 1997.
Artigo em Português | MEDLINE | ID: mdl-9497543

RESUMO

UNLABELLED: The authors describe the anatomical characteristics of the levator labii superioris muscle by dissection in cadavers. PURPOSE: We describe the characteristics of these muscle, the details and relations, hopefully contributing to the study of muscle of the face. METHODS: Twenty faces of cadavers were dissected. The following features were studied: origin, insertion, length, width, thickness, relations, innervation and blood supply. RESULTS: In all cases the muscle originated from the inferior orbital margin. Two insertions were observed: via lateral fibers, superficial to the orbicularis oris muscle and via deep fibers than form part of the raphe at the corner of the mouth (70%); via superficial fibers to the orbicularis oris muscle (30%). The average of the length was 24.66 mm and the average of the thickness was 3.57mm. The width at its insertion was 11.2mm, and at the origin was 15.96mm. The levator labii superioris muscle was found to be anterior to the levator anguli oris; it was posterior to the distal portion of the zygomaticus minor (90%) and posterior to the mid portion of the zygomaticus minor (10%). The innervation was from the inferior branch of the zygomatic nerve (facial nerve) and from the infraorbital nerve (trigeminal nerve). The inferior portion of the muscle is supplied by branches of the angular artery and the superior part from branches of the infraorbital artery.


Assuntos
Músculos Faciais/anatomia & histologia , Lábio , Adulto , Idoso , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Arch Biochem Biophys ; 340(2): 185-94, 1997 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9143320

RESUMO

A type II ribosome-inactivating protein (RIP) was isolated from the bark tissue of Japanese elderberry (Sambucus sieboldiana) and named sieboldin-b. Sieboldin-b is a heterodimeric protein consisting of 27- and 33-kDa subunits and showed strong ribosome-inactivating activity in vitro but did not show in vivo toxicity. The amino acid sequence of sieboldin-b deduced from the structure of the cDNA showed that both subunits of sieboldin-b are encoded on a single precursor polypeptide. Sieboldin-b has a structure homologous with the Neu5Ac(alpha 2-6)Gal/GalNAc-specific bark lectin from S. sieboldiana (SSA) and also typical type II RIPs such as ricin and abrin. Detailed analyses of carbohydrate binding properties of sieboldin-b revealed that sieboldin-b binds to Gal/GalNAc, similar to ricin/abrin, in spite of its highly homologous structure with SSA. The biological properties of these toxins/lectins are compared, and the possible explanation for such diversity is discussed.


Assuntos
Lectinas/química , N-Glicosil Hidrolases/genética , Inibidores da Síntese de Proteínas , Sequência de Aminoácidos , Metabolismo dos Carboidratos , Clonagem Molecular , DNA Complementar/genética , Genes de Plantas , Células HeLa , Humanos , Lectinas/genética , Lectinas/metabolismo , Dados de Sequência Molecular , Peso Molecular , Lectinas de Plantas , Plantas/genética , RNA de Plantas , Proteínas Inativadoras de Ribossomos
19.
Mol Plant Microbe Interact ; 9(7): 546-55, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8810069

RESUMO

The soybean response to inoculation with B. japonicum mutants defective in cyclic beta-(1-->3), beta-(1-->6) glucan synthesis was examined by electron microscopy and by monitoring the expression of early and late nodulin genes. Two mutants were examined. Strain AB-14 is an ndvB mutant and is unable to synthesize beta-glucans. Strain AB-1 is an ndvC mutant and produces cyclic glucans containing 95 to 100% beta-(1-->3) glycosidic linkages. Nodules formed by either mutant were defective in nitrogen fixation activity. Soybean plants inoculated with strain AB-14 formed nodules roughly at the same rate as the wild-type strain USDA110, but nodulation by strain AB-1 was significantly delayed. Microscopy of nodules formed by strain AB-14 showed an overall ultrastructure similar to nodules formed by the wild type. However, in some nodules bacteroids were limited to only one part of the infected cells and in others the few bacteroids present showed signs of degradation. Nodulelike structures were formed by strain AB-1 that showed some signs of cellular differentiation. For example, clear parenchyma and sclerenchyma tissue could be seen. However, no infection threads or bacteria were evident in these structures. The expression of early (e.g., ENOD2 and ENOD55) and late (e.g., NOD26 and leghemoglobin) nodulins was examined. Nodules formed by strain AB-14 expressed all of the nodulins tested but at a reduced level. Expression of late nodulins was delayed in strain AB-14-induced nodules. Nodules formed by strain AB-1 were more strongly affected in nodulin expression. Although leghemoglobin synthesis was not detected, infection-specific nodulin transcripts of GmN93 and ENOD55 were detected. However, expression of the early nodulins ENOD2 and ENOD55 was considerably delayed and only apparent when assayed 21 days postinoculation. A low level of expression of intermediate nodulin GmN70 and late nodulin NOD26 could also be detected by 21 days postinoculation. The microscopy data show that tissue differentiation occurs in these nodules even in the absence of active bacterial invasion. These results demonstrate the importance of cyclic beta-(1-->3), beta-(1-->6) glucan synthesis to symbiotic development in soybean.


Assuntos
Glucanos/biossíntese , Glycine max/microbiologia , Proteínas de Plantas/biossíntese , Rhizobiaceae/genética , Primers do DNA , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana/biossíntese , Microscopia Eletrônica , Mutagênese , Reação em Cadeia da Polimerase , Rhizobiaceae/metabolismo , Glycine max/metabolismo , Glycine max/ultraestrutura
20.
Mol Plant Microbe Interact ; 9(7): 574-83, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8810072

RESUMO

Various lipo-chitin molecules were tested for their ability to induce the expression of the early nodulin, ENOD2, in Glycine soja roots. When inoculated separately onto G. soja roots, LCO-V (C18:1 delta 11,Mefuc), LCO-V (C18:1 delta 9,Mefuc), LCO-V (C16:0,Mefuc), and LCO-IV (C16:0) were unable to induce ENOD2 expression, even though these compounds had previously been shown to induce root hair curling, the formation of nodule-like primordia, and induction of the early nodulin, ENOD40. ENOD2 expression, however, was induced when any two of these molecules were inoculated in combination. Thus, the lipo-chitin nodulation signals appear to act cooperatively to induce ENOD2 expression. B. japonicum strains USDA110 and USDA135 and B. elkanii strain USDA61, all symbionts of soybean, were found to produce at least two distinct nod signals ([i.e., NodBj-V[C18:1,Mefuc] and NodBj-V[C16:0,Mefuc]). These two compounds were mixed in various ratios and tested for their ability to induce ENOD2 expression. The results indicate that the former compound must be present in equivalent or excess amount in order to obtain maximum ENOD2 expression. Additional nonspecific LCOs (e.g., LCO-IV[C16:2 delta 2,9; SO3]), incapable of inducing root hair curling or cortical cell division, were tested in combination with the four active LCOs listed above. It was found that any combination of one active LCO with a nonspecific LCO was sufficient to induce ENOD2 mRNA expression. The ENOD2 mRNA expression pattern detected by in situ hybridization closely resembled that found in bacterial-induced nodules with expression detected in cortical cells between primary and secondary meristems and around the vascular strands. These data demonstrate that the cooperative action of at least two LCO nodulation signals leads to a greater progression of nodule ontogeny as demonstrated by the expression of ENOD2, a marker gene for the differentiation of nodule parenchyma.


Assuntos
Quitina/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glycine max/fisiologia , Fixação de Nitrogênio , Proteínas de Plantas/biossíntese , Rhizobiaceae/fisiologia , Transcrição Gênica , Sequência de Carboidratos , Quitina/análogos & derivados , Quitina/química , Quitina/farmacologia , Primers do DNA , Dados de Sequência Molecular , Raízes de Plantas , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Espectrometria de Massas de Bombardeamento Rápido de Átomos
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