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1.
Exp Parasitol ; 153: 111-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25816973

RESUMO

Toxoplasma gondii is a parasite of great medical and veterinary importance that has worldwide distribution and causes toxoplasmosis. There are few treatments available for toxoplasmosis and the search for plant extracts and compounds with anti-Toxoplasma activity is of utmost importance for the discovery of new active drugs. The objective of this study was to investigate the action of a protein extract and a protease inhibitor enriched fraction from J. curcas seed cake on developing tachyzoites of T. gondii-infected Vero cells. The protein extract (JcCE) was obtained after solubilization of the J. curcas seed cake with 100 mM sodium borate buffer, pH 10, centrifugation and dialysis of the resulting supernatant with the extracting buffer. JcCE was used for the in vitro assays of anti-Toxoplasma activity at 0.01, 0.1, 0.5, 1.5, 3.0 and 5.0 mg/ml concentration for 24 h. The results showed that JcCE reduced the percentage of infection and the number of intracellular parasites, but had no effect on the morphology of Vero cells up to 3.0 mg/mL. The cysteine protease inhibitor enriched fraction, which was obtained after chromatography of JcCE on Sephadex G-75 and presented a unique protein band following SDS-PAGE, reduced both the number of T. gondii infected cells and intracellular parasites. These results suggest that both JcCE and the cysteine protease inhibitor enriched fraction interfere with the intracellular growth of T. gondii.


Assuntos
Antiprotozoários/farmacologia , Jatropha/química , Extratos Vegetais/farmacologia , Sementes/química , Toxoplasma/efeitos dos fármacos , Toxoplasmose/parasitologia , Animais , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Chlorocebus aethiops , Humanos , Masculino , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Inibidores de Proteases/química , Inibidores de Proteases/isolamento & purificação , Inibidores de Proteases/farmacologia , Toxoplasma/crescimento & desenvolvimento , Toxoplasmose/tratamento farmacológico , Células Vero
2.
Reprod Domest Anim ; 49(3): 409-19, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24716618

RESUMO

This study describes the reproductive parameters of Morada Nova rams, a breed of hair sheep from Brazil and with unique adaption to tropical environments. At 42 weeks of age, 15 rams were subjected to semen collection and, 1 week later, animals were slaughtered for collection of testes, epididymis and accessory sex glands. We conducted 2-D electrophoresis of seminal plasma proteins and major spots of stained gels were identified by LC-MS/MS. Total RNA was isolated from testis, epididymis and vesicular glands and subjected to qPCR. At slaughter, scrotal circumference and testicular weight were 27.5 ± 0.5 cm and 109.5 ± 6.0 g, respectively. Seminiferous tubule (ST) diameter was 188.3 ± 4.0 µm and each testis contained 1.9 ± 0.1 Sertoli cells (×10(9) ). Each Sertoli cell supported 0.1 ± 0.01 A spermatogonia, 3.0 ± 0.2 pachytene spermatocytes and 7.7 ± 0.5 round spermatids/tubule cross section. Daily sperm production reached 5.6 × 10(6)  cells/g of testis parenchyma. Testis size appeared as indicative of ST diameter and associated with epididymal measurements, as well as with the population of round spermatids and Sertoli cells/testis. Rams with heavier testes had greater daily sperm production and more Sertoli cells/testis. We detected 90.9 ± 9.6 spots per 2-D gel of seminal plasma. Major seminal proteins were identified as ram seminal vesicle proteins at 14 and 22 kDa, representing 16.2% and 12.8% of the total intensity of valid spots in the gels, respectively. Expression of both genes was greater in the vesicular glands as compared to testis and epididymis. Pixel intensity for those proteins in the 2-D gels was significantly correlated with seminal vesicle weight. This is the first description of the basic reproductive aspects of Morada Nova rams, including protein profiles of their seminal plasma. These findings will allow a better understanding of their reproductive physiology.


Assuntos
Reprodução , Proteínas de Plasma Seminal/análise , Ovinos , Espermatogênese , Testículo/anatomia & histologia , Clima Tropical , Adaptação Fisiológica/genética , Animais , Brasil , Cruzamento , Epididimo/anatomia & histologia , Expressão Gênica , Masculino , Tamanho do Órgão , Escroto/anatomia & histologia , Análise do Sêmen/veterinária , Proteínas de Plasma Seminal/genética , Contagem de Espermatozoides/veterinária
3.
ScientificWorldJournal ; 2014: 919570, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24563633

RESUMO

Blood supply is essential for development and growth of tumors and angiogenesis is the fundamental process of new blood vessel formation from preexisting ones. Angiogenesis is a prognostic indicator for a variety of tumors, and it coincides with increased shedding of neoplastic cells into the circulation and metastasis. Several molecules such as cell surface receptors, growth factors, and enzymes are involved in this process. While antiangiogenic therapy for cancer has been proposed over 20 years ago, it has garnered much controversy in recent years within the scientific community. The complex relationships between the angiogenic signaling cascade and antiangiogenic substances have indicated the angiogenic pathway as a valid target for anticancer drug development and VEGF has become the primary antiangiogenic drug target. This review discusses the basic and clinical perspectives of angiogenesis highlighting the importance of comparative biology in understanding tumor angiogenesis and the integration of these model systems for future drug development.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Neoplasias/irrigação sanguínea , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Neoplasias/fisiopatologia , Células-Tronco Neoplásicas/metabolismo , Neovascularização Patológica/fisiopatologia , Transdução de Sinais/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
4.
Reprod Domest Anim ; 45(4): 644-53, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19170953

RESUMO

We have investigated the reproductive development of the tropically adapted Santa Inês ram, the most common hair sheep in Brazil. From 8 to 48 weeks of age, 16 animals were evaluated for body and testis growth, semen parameters, testosterone concentrations and seminal plasma proteins, using two-dimensional SDS-PAGE. Animals were weaned at 30 days and kept in feedlots thereafter, receiving hay, concentrate (18% of crude protein) and mineral supplement. Body weight increased from 12.3 +/- 0.7 to 54.3 +/- 1.6 kg between 8 and 48 weeks (p < 0.05), but changes in thoracic perimeter and scrotal circumference were non-significant after 36 weeks (p > 0.05). The percentage of motile sperm increased slowly until 23 weeks and more rapidly after that age, but significant changes in progressive motility occurred after 25 weeks. Presence of abnormal sperm related inversely to age. Most significant changes in sperm concentration occurred between 38 and 44 weeks (0.38 +/- 0.05 to 1.14 +/- 0.24 x 10(9) cells/ml, p < 0.05) and testosterone reached its highest concentrations at 42 weeks, decreasing afterwards. Rams reached puberty at 28.2 +/- 0.8 weeks. The number of protein spots on seminal plasma gels was similar from 15 to 18 weeks (45 and 47 spots; p > 0.05), increased until 24 weeks (141 spots) and 28 weeks (170 spots; p < 0.05) and remained without significant (p > 0.05) changes from 28 to 48 weeks (186 +/- 10 spots). Furthermore, the intensity of selected spots on 2D maps increased (p < 0.05) between 15 and 28 weeks, which preceded or coincided with the main developmental changes in sperm motility and percentage of defective sperm in the ejaculates. These results will support future studies designed to characterize specific seminal plasma proteins whose expression relate to the development of testis, epididymis and accessory sex glands.


Assuntos
Sêmen/química , Maturidade Sexual/fisiologia , Ovinos/crescimento & desenvolvimento , Espermatozoides/fisiologia , Testículo/crescimento & desenvolvimento , Testosterona/sangue , Envelhecimento , Animais , Masculino , Sêmen/metabolismo , Ovinos/sangue , Ovinos/fisiologia
5.
Toxicon ; 51(6): 952-63, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18328522

RESUMO

SBTX, a novel toxin from soybean, was purified by ammonium sulfate fractionation followed by chromatographic steps DEAE-Cellulose, CM-Sepharose and Superdex 200 HR fast-protein liquid chromatography (FPLC). Lethality of SBTX to mice (LD(50) 5.6 mg/kg) was used as parameter in the purification steps. SBTX is a 44-kDa basic glycoprotein composed of two polypeptide chains (27 and 17 kDa) linked by a disulfide bond. The N-terminal sequences of the 44 and 27kDa chains were identical (ADPTFGFTPLGLSEKANLQIMKAYD), differing from that of 17 kDa (PNPKVFFDMTIGGQSAGRIVMEEYA). SBTX contains high levels of Glx, Ala, Asx, Gly and Lys and showed maximum absorption at 280 nm, epsilon(1cm)(1%) of 6.3, and fluorescence emission in the 290-450 nm range upon excitation at 280nm. The secondary structure content was 35% alpha-helix, 13% beta-strand and beta-sheet, 27% beta-turn, 25% unordered, and 1% aromatic residues. Immunological assays showed that SBTX was related to other toxic proteins, such as soyatoxin and canatoxin, and cross-reacted weekly with soybean trypsin inhibitor and agglutinin, but it was devoid of protease-inhibitory and hemagglutinating activities. The inhibitory effect of SBTX on growth of Cercospora sojina, fungus causing frogeye leaf spot in soybeans, was observed at 50 microg/ml, concentration 112 times lesser than that found to be lethal to mice. This effect on phytopathogenic fungus is a potential attribute for the development of transgenic plants with enhanced resistance to pathogens.


Assuntos
Antifúngicos/farmacologia , Glycine max/toxicidade , Glicoproteínas/isolamento & purificação , Glicoproteínas/toxicidade , Hemaglutinação/efeitos dos fármacos , Fungos Mitospóricos/efeitos dos fármacos , Proteínas de Soja/isolamento & purificação , Proteínas de Soja/toxicidade , Sequência de Aminoácidos , Animais , Cromatografia em Gel/métodos , Cromatografia Líquida/métodos , Eletroforese em Gel de Poliacrilamida , Glicoproteínas/química , Hemaglutinação/fisiologia , Camundongos , Fungos Mitospóricos/crescimento & desenvolvimento , Dados de Sequência Molecular , Peso Molecular , Proteínas de Plantas/química , Proteínas de Plantas/toxicidade , Estrutura Secundária de Proteína , Proteínas de Soja/química , Glycine max/química , Análise Espectral , Toxinas Biológicas/química , Toxinas Biológicas/toxicidade
6.
Protein Pept Lett ; 15(4): 327-32, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18473942

RESUMO

A precursor of ConBr, a glucose/mannose-binding plant lectin, was expressed in the yeast Pichia pastoris. Western blot analysis of transformed cells detected an intracellularly recombinant protein band with ca. 34.5 kDa. The recombinant protein was apparently active as suggested by its strong interaction with the mannose-rich yeast cell debris.


Assuntos
Pichia/genética , Lectinas de Plantas/biossíntese , Canavalia , Clonagem Molecular , Expressão Gênica , Vetores Genéticos , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Complexos Multienzimáticos/metabolismo , Nistatina/metabolismo , Nistatina/farmacologia , Peptídeo Hidrolases/metabolismo , Pichia/metabolismo , Lectinas de Plantas/isolamento & purificação , Proteínas Recombinantes/biossíntese , Transformação Genética
7.
Biochim Biophys Acta ; 1764(6): 1141-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16766236

RESUMO

An actual worldwide problem consists of an expressive increase of economic losses and health problems caused by fungi. In order to solve this problem, several studies have been concentrating on the screening of novel plant defence peptides with antifungal activities. These peptides are commonly characterized by having low molecular masses and cationic charges. This present work reports on the purification and characterization of a novel plant peptide of 5.0 kDa, Pe-AFP1, purified from the seeds of passion fruit (Passiflora edulis). Purification was achieved using a Red-Sepharose Cl-6B affinity column followed by reversed-phase chromatography on Vydac C18-TP column. In vitro assays indicated that Pe-AFP1 was able of inhibiting the development of the filamentous fungi Trichoderma harzianum, Fusarium oxysporum, and Aspergillus fumigatus with IC50 values of 32, 34, and 40 microg ml(-1), respectively, but not of Rhyzoctonia solani, Paracoccidioides brasiliensis and Candida albicans. This protein was also subjected to automated N-terminal amino acid sequence, showing high degree of similarities to storage 2S albumins, adding a new member to this protein-defence family. The discovery of Pe-AFP1 could contribute, in a near future, to the development of biotechnological products as antifungal drugs and transgenic plants with enhanced resistance to pathogenic fungi.


Assuntos
Albuminas/química , Antifúngicos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos/química , Sequência de Aminoácidos , Bioensaio , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Passiflora , Proteínas de Plantas/química , Sementes/metabolismo , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos
8.
Toxicon ; 50(7): 971-83, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17825863

RESUMO

Ureases (EC 3.5.1.5) are nickel-dependent metalloenzymes that catalyze the hydrolysis of urea to ammonia and carbon dioxide. Produced by plants, fungi and bacteria, but not by animals, ureases share significant homology and similar mechanisms of catalysis, although differing in quaternary structures. While fungal and plant ureases are homo-oligomeric proteins of 90 kDa subunits, bacterial ureases are multimers of two (e.g. Helicobacter pylori) or three subunit complexes. It has been proposed that in plants these enzymes are involved in nitrogen bioavailability and in protection against pathogens. Previous studies by our group have shown that plant ureases, but not a bacterial (Bacillus pasteurii) urease, display insecticidal activity. Herein we demonstrate that (Glycine max) embryo-specific soybean urease, jackbean (Canavalia ensiformis) major urease and a recombinant H. pylori urease impair growth of selected phytopathogenic fungi at sub-micromolar concentrations. This antifungal property of ureases is not affected by treatment of the proteins with an irreversible inhibitor of the ureolytic activity. Scanning electron microscopy of urease-treated fungi suggests plasmolysis and cell wall injuries. Altogether, our data indicate that ureases probably contribute to the plant arsenal of defense compounds against predators and phytopathogens and that the urease defense mechanism is independent of ammonia release from urea.


Assuntos
Antifúngicos/farmacologia , Canavalia/enzimologia , Glycine max/enzimologia , Helicobacter pylori/enzimologia , Urease/farmacologia , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Relação Dose-Resposta a Droga , Fungos/efeitos dos fármacos , Fungos/ultraestrutura , Dados de Sequência Molecular , Proteínas de Plantas/metabolismo , Proteínas de Plantas/farmacologia , Proteínas Recombinantes , Fatores de Tempo , Urease/química , Urease/metabolismo
9.
N Biotechnol ; 39(Pt A): 99-109, 2017 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-27737801

RESUMO

Various plant species have long been used in traditional medicine worldwide to treat diabetes. Among the plant-based compounds with hypoglycemic properties, studies on insulin-like proteins isolated from leaves, fruits and seeds are rarely reported in the relevant literature. Our research group has been investigating the presence of insulin-like proteins in Moringa oleifera, a plant species native to India, and we have obtained a leaf protein isolate and semi-purified derived fractions, as well as a seed coat protein fraction (Mo-SC), with hypoglycemic activity in chemically induced diabetic mice that have increased tolerance to orally administered glucose. Equally importantly, Mo-SC possesses insulin-like antigenic epitopes. In this context, the present review aims to highlight that prospection of insulin-like proteins in plants is of the utmost importance both for finding new drugs for the treatment of diabetes and for shedding light on the mechanisms involved in diabetes.


Assuntos
Diabetes Mellitus/tratamento farmacológico , Insulina/uso terapêutico , Moringa oleifera/química , Proteínas de Plantas/uso terapêutico , Sequência de Aminoácidos , Animais , Humanos , Insulina/química , Insulina/isolamento & purificação , Lectinas/uso terapêutico , Folhas de Planta/química , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação
10.
Acta Trop ; 60(4): 237-50, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8659323

RESUMO

In vivo administration of Canavalia brasiliensis lectin (at the time of infection, or maintained throughout the infection) reduced the lesions of highly susceptible BALB/c mice infected by Leishmania amazonensis. At the doses used C. brasiliensis lectin (ConBr) does not interfere with penetration or fate of Leishmania in the macrophages in vitro. Since Interferon-gamma (IFN-gamma) is the major macrophage activating factor, and considered a critical element in the successful immune response against leishmaniasis, we explored its participation in this phenomenon. ConBr either in vivo or in vitro induced IFN-gamma production in normal or in leishmania-infected BALB/c mice. However we were unable to change the course of disease by in vivo IFN-gamma administration (although IFN-gamma preparations were effective in inducing a leishmanicidal effect in vitro on L. amazonensis-infected peritoneal macrophages). Additionally, IFN-gamma neutralization with anti-IFN-gamma monoclonal antibody did not alter the protection conferred by ConBr administration. These data show that lectin administration in vivo is protective in the otherwise unchecked L. amazonensis infection of BALB/c mice, and suggest that such effect is not mediated by IFN-gamma.


Assuntos
Interferon gama/biossíntese , Lectinas/uso terapêutico , Leishmania mexicana , Leishmaniose Cutânea/terapia , Animais , Feminino , Interferon gama/farmacocinética , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Ratos
11.
Food Chem Toxicol ; 42(11): 1737-47, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15350671

RESUMO

This present work was undertaken to answer two basic questions (a) is C. argentea lectin part of the general defensive strategy of the plant against predation by animals? (b) if so, how does it act on them? To achieve these goals the lectin from C. argentea seeds was purified to homogeneity and included at a 2% level in a diet containing 10% total protein and given to growing rats for 10 days. In vivo it was noted that the lectin from C. argentea is resistant to gut proteolysis, binds to the cells lining the small intestine and induces enlargement in the small intestine, caecum and colon, kidneys and pancreas compared to control rats exposed to the egg-white diet (EW). As the diet containing the purified C. argentea lectin has the same basic composition and protein content of EW diet, the small intestine, kidney and pancreas enlargements are clearly lectin-specific effects. Moreover the animals exposed to the lectin-containing diet presented a significant reduction in the growth rate and lower values of digestibility, NPU and biological value compared to animals fed on a control lectin-free diet. Thus the data from this present study and the report that the C. argentea lectin has insecticidal activity upon Callosobruchus maculatus larvae which attacks cowpea (Vigna unguiculata) seeds reinforce the hypothesis that lectins take part in the mechanisms against herbivory.


Assuntos
Sistema Digestório/efeitos dos fármacos , Fabaceae/química , Insetos/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Ratos Wistar/crescimento & desenvolvimento , Animais , Bioensaio , Digestão/efeitos dos fármacos , Sistema Digestório/patologia , Eletroforese em Gel de Poliacrilamida , Fezes/química , Hemaglutinação/efeitos dos fármacos , Imuno-Histoquímica , Insetos/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Masculino , Tamanho do Órgão/efeitos dos fármacos , Lectinas de Plantas/administração & dosagem , Lectinas de Plantas/química , Lectinas de Plantas/isolamento & purificação , Distribuição Aleatória , Ratos , Sementes/química , Aumento de Peso/efeitos dos fármacos
12.
Braz J Med Biol Res ; 29(8): 977-85, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9181078

RESUMO

A lectin was purified from seeds of Erythrina velutina forma aurantiaca by affinity chromatography on cross-linked guar gum. The lectin is a potent agglutinin for human (minimal concentration of protein able to cause visible agglutination of a 2% erythrocyte suspension varying from 1 to 4 micrograms/ml), rabbit (4 micrograms/ml) and chicken erythrocytes (8 micrograms/ml) but presented low activity against cow (250 micrograms/ml) or sheep (333 micrograms/ml) blood cells. Hemagglutination of human O+ erythrocytes was inhibited by D-lactose (0.2 mM) > D-galactose (0.8 mM) > D-raffinose (2.1 mM). At pH 7.5, chromatography on a Superose 12 HR 10/30 column showed that the lectin was primarily a dimer (56.0 kDa) composed of two identical subunits (31.6 kDa each). A small amount of a tetrameric form was also apparently present. The lectin is a glycoprotein (7.3% carbohydrate), has a pI of 4.5, contains high levels of acidic (Asp and Glu, 64.2 and 51.6 residues/mol, respectively) and hydroxy amino acids (Ser and Thr, 42.9 and 38.5 residues/mol, respectively) but relatively low amounts of sulfur amino acids (Cys and Met, 1.0 and 5.0 residues/mol, respectively) and has an N-terminal sequence of Val-Glu-Thr-Ile/Leu-Pro-Phe-Ser. Its hemagglutinating activity was abolished by heating at 70 degrees C for 10 min. The activation energy (delta G') required for denaturation measured by loss of hemagglutination activity was 24.87 kcal/mol. In rats, the purified lectin (100 micrograms) induced neutrophil migration into the peritoneal cavity (3.7 +/- 0.6 x 10(6) neutrophils/ml) or into the air pouch (2.75 +/- 0.25 x 10(6) neutrophils/ml), 8 and 10 times greater than the negative control, respectively.


Assuntos
Erythrina/química , Lectinas/química , Plantas Medicinais , Animais , Brasil , Humanos , Lectinas/isolamento & purificação , Lectinas de Plantas , Ratos , Ratos Wistar , Sementes/química
13.
Braz J Med Biol Res ; 25(8): 823-6, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1342615

RESUMO

Peritoneal macrophage stimulation (rapid spreading on glass surface and hydrogen peroxide production) and inflammatory reaction (leukocyte accumulation) obtained in C3H/HeJ mice at 8 weeks of age, after a single ip injection of 10 micrograms concanavalin A (Con A), a lectin extracted from Canavalia ensiformis, were compared with those obtained with two other glucose/mannose-binding lectins extracted from Canavalia brasiliensis (Con Br) and Dioclea grandiflora (DGL). All lectins enhanced macrophage spreading 3- to 4-fold at 24-72 h compared to control. Stimulation of hydrogen peroxide release by Con A, Con Br and DGL lasted 1, 2 and 3 days, respectively. Leukocyte cell influx at 24-72 h after lectin injection consisted mainly of mononuclear cells. Con A induced a moderate increase in the total number of peritoneal cells, whereas administration of Con Br or DGL increased the number of peritoneal cells 2- to 3-fold. The results indicate that DGL and Con Br have more pronounced effects on macrophage stimulation and inflammatory reactions than Con A.


Assuntos
Glucose/metabolismo , Lectinas/administração & dosagem , Leucócitos/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Manose/metabolismo , Animais , Injeções Intraperitoneais , Lectinas/farmacologia , Leucócitos/imunologia , Ativação de Macrófagos/imunologia , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos C3H , Estimulação Química , Fatores de Tempo
14.
Environ Exp Bot ; 46(1): 37-46, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11378171

RESUMO

The nitrate reductase activity distribution and response of two nodulated species of Phaseolus (Phaseolus vulgaris-common bean, and Phaseolus lunatus-lima bean) to different exogenous nitrate levels were studied during the vegetative period. These Phaseolus species showed to be very contrasting in respect to the pattern of nitrate reductase (NR) activity distribution thought the plant. The highest level of NR activity in P. vulgaris was clearly shown to occur in leaves in contrast with the lowest one detected in roots and nodules as widely seen for other tropical species of the Phaseoleae tribe. Conversely, P. lunatus had higher NR activity in the nodules, whereas its leaves exhibited a steadily decrease during the plant development. Indeed, at 32 days after emergence (pre-flowering stage), the nodulated P. vulgaris had approximately 95% of the total NR activity localized in its leaves, whereas in P. lunatus it was equally distributed in the nodules and in the leaves. Under long-term exposure to increasing exogenous level of nitrate, the leaf-NR activity of nodulated P. vulgaris presented a positive response, whereas the enzyme activity was very low and unresponsive in P. lunatus. In contrast, the nodule-NR activity showed a reverse response to the increasing NO(3)(-) level. The nodule-NR activity of P. lunatus significantly increased whereas in the P. vulgaris nodules it was very low and unresponsive. This present study suggests that P. lunatus inoculated with Rhizobium tropici presents a singular pattern of nitrate reduction distribution among leaves and nodules during the vegetative development. It is speculated that the nodulated Phaseolus lunatus may have different NR isoforms in their leaves (at least a constitutive type) and an inducible form in their nodules, responsive to long-term exposure to nitrate.

15.
Arq Neuropsiquiatr ; 58(2A): 360-5, 2000 Jun.
Artigo em Português | MEDLINE | ID: mdl-10849642

RESUMO

The knowledge of biological pain mechanisms are not sufficient for the understanding of patients with chronic pain syndromes such as low back, cervicobrachial and muscle pain. Psychological and psychosocial aspects play important roles in the setting and perpetuation of symptoms. Mood and anxiety disorders, secondary gains such as early retirement and financial compensations, must all be acknowledged by the physician as possible contributors to the symptoms. Abnormal illness behavior may better characterize patients with chronic pain syndromes. Behavior observation, which is akin to medical practice, is therefore a powerful tool in the diagnosis and management of these syndromes. Physicians ought be very careful in not reinforcing the patients already strong organic convictions regarding their symptoms, avoiding making decisions based on patients complaints and alleged disabilities, and assigning poorly defined and disputable diagnosis labels. Society needs also to refrain from policies that encourage abnormal illness behaviors.


Assuntos
Dor , Papel do Doente , Doença Crônica , Diagnóstico Diferencial , Transtornos Autoinduzidos/diagnóstico , Transtornos Autoinduzidos/psicologia , Humanos , Simulação de Doença/diagnóstico , Simulação de Doença/psicologia , Dor/classificação , Dor/diagnóstico , Dor/psicologia , Transtornos Somatoformes/diagnóstico , Transtornos Somatoformes/psicologia , Síndrome
16.
Arq Neuropsiquiatr ; 57(1): 126-31, 1999 Mar.
Artigo em Português | MEDLINE | ID: mdl-10347739

RESUMO

The hypothesis that repetitive movements and postures cause musculoskeletal injury is not supported by scientific data. The sensory and pain symptoms are better explained as of psychological and psychosocial nature, such as job dissatisfaction or disajustment, with financial gains objectives. The repetitive strain injury concept is iatrogenic and costly to society, and must be abandoned.


Assuntos
Transtornos Traumáticos Cumulativos , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/etiologia , Transtornos Traumáticos Cumulativos/história , História do Século XX , Humanos
17.
Arq Neuropsiquiatr ; 58(4): 1142-8, 2000 Dec.
Artigo em Português | MEDLINE | ID: mdl-11105088

RESUMO

The diagnosis of carpal tunnel syndrome (CTS) may be difficult because paresthesias and tingling in the upper limbs are commonly reported in the general population. These symptoms are poorly correlated with changes of nerve conduction studies of the median nerve. CTS should be diagnosed only when typical symptoms are associated with significant electrophysiological abnormalities. The association of CTS with work is highly controversial.


Assuntos
Síndrome do Túnel Carpal/diagnóstico , Doenças Profissionais/diagnóstico , Adulto , Idoso , Síndrome do Túnel Carpal/epidemiologia , Síndrome do Túnel Carpal/etiologia , Eletrofisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Prevalência , Fatores de Risco
18.
Arq Neuropsiquiatr ; 52(1): 96-9, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8002819

RESUMO

A 16-year-old male patient who presented with muscle stiffness and dysphonia is described. Electromyography revealed continuous motor activity that was unaffected by peripheral nerve block or general anaesthesia, but was abolished by curare. The patient had a marked improvement after using phenytoin. The follow-up 11-years later corroborates with the proposed benignity of this syndrome, in spite of being dependent on medication.


Assuntos
Rigidez Muscular/fisiopatologia , Músculos/fisiopatologia , Adolescente , Eletromiografia , Seguimentos , Humanos , Masculino , Atividade Motora/fisiologia , Rigidez Muscular/diagnóstico , Rigidez Muscular/tratamento farmacológico , Músculos/efeitos dos fármacos , Fenitoína/uso terapêutico , Rigidez Muscular Espasmódica/diagnóstico , Rigidez Muscular Espasmódica/tratamento farmacológico , Rigidez Muscular Espasmódica/fisiopatologia , Distúrbios da Voz/tratamento farmacológico , Distúrbios da Voz/etiologia , Distúrbios da Voz/fisiopatologia
19.
Arq Neuropsiquiatr ; 50(2): 216-8, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1308394

RESUMO

The case of a Brazilian patient with cortico-basal ganglionic degeneration (CBGD) is presented. Since three years ago, a 71-year old male displays asymmetric ideomotor apraxia, gait apraxia, cortical sensory impairment, myoclonus, limp dystonia and rigidity. His mental status is spared. There is neither consanguinity nor similar cases in his family. The differential diagnosis of CBGD is discussed. A brief review of the literature is made stressing the clinical and pathological features of CBGD. This disease is poorly known and probably underdiagnosed. Its diagnosis can be safely made based on clinical grounds.


Assuntos
Gânglios da Base/patologia , Córtex Cerebral/patologia , Degeneração Neural , Idoso , Apraxias/fisiopatologia , Gânglios da Base/fisiologia , Córtex Cerebral/fisiologia , Humanos , Masculino
20.
Arq Neuropsiquiatr ; 53(2): 198-202, 1995 Jun.
Artigo em Português | MEDLINE | ID: mdl-7487523

RESUMO

From 1971 to 1993, 52 myasthenics without thymomas (7 men and 45 women) were thymectomized. The results were categorized in remissions and non-remissions. The remission rate was 48%. In the remission group there were 5 men and 20 women and in the non-remission group 2 men and 25 women. The follow-up time was 5.5 years in both groups. There were 16 patients in Osserman category II A, 11 achieving remission; 36 patients were in categories IIB and III, and 14 achieved remission. The duration of disease was 1.8 years and 4.3 years in the remission and non-remission groups, respectively. All patients with remission had less than four years of disease but among the 43 patients with less than four years of symptoms, 42% did not achieve remission. Our data reinforce the need for early thymectomy in myasthenia gravis.


Assuntos
Miastenia Gravis/cirurgia , Timectomia , Adolescente , Adulto , Fatores Etários , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Timo/patologia , Fatores de Tempo
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