RESUMO
RESUMO Ricinus communisé uma planta pertence à família Euforbiaceae. A partir de seus frutos é extraído o óleo de rícino e outra fração altamente tóxica (fração não-oleosa). Neste estudo, foi avaliado o efeito da fração não oleosa de R. communis(FNORC) na biodistribuição do Tc-99m em camundongos sadios e em animais transplantados com Sarcoma-180 (S180). Para avaliação da biodistribuição do Tc-99m, o percentual de atividade radioativa total injetada (ATI%) foi mensurada utilizando um contador gama. Os resultados mostraram que, em animais sadios, houve aumento da captação do Tc-99m após o tratamento com FNORC pelos rins, cérebro e estômago. Apenas houve diminuição da absorção deste radioisótopo nos músculos. Em animais com tumor, houve redução significativa da captação do Tc-99m no coração, pulmões e tumor, e foi observado o aumento da captação apenas nos rins. Foi observada também a diminuição da concentração das proteínas plasmáticas totais em animais com tumor após tratamento com FNORC e atividade antitumoral significativa. Diante desses dados, conclui-se que fração não oleosa de R. communis possui atividade antitumoral significativa, porém altera a biodistribuição do Tc-99m, fato este que pode resultar em falhas nos processos de diagnóstico por imagem que utilizem este radioisótopo como marcador.
ABSTRACT Ricinus communis is a plant belonging to the Euforbiaceae family. From its fruits, it is extracted the castor oil and another highly toxic fraction (non-oily fraction). In this study, we evaluated the effect of the non-oily fraction of R. communis (NOFRC) on the bio distribution of Tc-99m in healthy mice and in animals transplanted with Sarcoma-180 (S180). To evaluate the bio distribution of theTc-99m, the percentage of the total injected radioactivity (% TIR) was measured through a gamma counter. There was an increase in the capitation of Tc-99m after the treatment with NOFRC in the kidneys, brain, and stomach of healthy animals. A decrease in the reception of this radionuclide was only found in the muscles. In animals with tumour, there was a significant reduction in the uptake of Tc-99m in the heart, lungs and tumour. An increase in the capitation was only observed in the kidneys. It was also observed a reduction in the total plasma protein concentration in animals with tumours after the treatment with NOFRC, besides significant antitumor activity. We concluded that there is antitumor activity in the NOFRC, but that it alters the biodistribution of Tc-99m, a fact which may result in failures in the diagnostic imaging process using this radioisotope as a marker.
Assuntos
Animais , Masculino , Camundongos , /farmacologia , Tecnécio/análise , Camundongos/classificação , Neoplasias/complicaçõesRESUMO
Research for radiodiagnostic agents should considerate biological critical parameters which will give own contribution on the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with (99m)Tc(V) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in evaluation of bone metastasis. This work studied the biokinetics and dosimetry of (99m)Tc(V)-DMSA by animal model. The (99m)Tc(V)-DMSA was prepared from a (III)DMSA kit alkalized. Mice (n=5) received (99m)Tc(V)DMSA i.v., they were sacrificed (30 min, 1h, 5h and 12h), the organs excised and the activities measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated (MIRDOSE 3.0 program) by extrapolation of data from animal to human scale. The results showed the majority of organs reached the top uptake at 30 min, the greatest kidney uptake was (4.81 +/- 1.38)% activity/g, while the bone presented its highest uptake at 1h (5.49+/- 0.47)% activity/g, after 1h all the organs had activity exponential decrease. The biokinetic profile of (99m)Tc(V)-DMSA was well established, allowing quantifying of residence time, and the radiation dose estimates were made for this agent. About the absorbed dose, the preliminary results showed higher value to bone, being the soft tissue dose relatively low.
Assuntos
Radiometria/métodos , Ácido Dimercaptossuccínico Tecnécio Tc 99m/química , Absorção , Animais , Camundongos , Metástase Neoplásica , Doses de Radiação , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Ácido Dimercaptossuccínico Tecnécio Tc 99m/farmacocinética , Fatores de Tempo , Distribuição TecidualRESUMO
Epidemiological studies have implicated maternal protein-calorie deficiency as an important public health problem in developing countries. Over the last decades, a remarkable diffusion of electricity and an increased level of the electromagnetic field (EMF) in the environment have characterized modern societies. Therefore, researchers are concerned with the biological effects of 50-60 Hz, EMF. The aim of this paper is to show the effects of EMF of 60 Hz, 3 μT, exposure for two hours per day in the regulation of the hormonal and metabolic concentrations in pregnant rats, which were fed by Regional Basic Diet (RBD) during their pregnancy as compared with pregnant rats fed a standard diet. Pregnant rats exposed to EMF of 60 Hz, 3 μT, over the pregnancy and fed with RBD presented an increase in glucose release when compared with the Group subjected only to the RBD ration. Rats fed RBD presented a decrease in their insulin and cortisol serum levels when compared with the Group fed with casein. The T3 and T4 concentrations presented the greatest variation among the Groups. The relation T4:T3 was much exaggerated in the Group subjected to RDB and exposed to EMF when compared to the others. In conclusion, the group subjected to the association of EMF and undernutrition suffered a decrease in its serum concentration of T4 and T3 when compared to the well-nourished group and the relationship T4:T3 in the former group was almost eighteen-fold the later one.
Estudos epidemiológicos têm mostrado que a deficiência proteico-calórica é um importante problema nos países em desenvolvimento. Durante as últimas décadas, a sociedade moderna tem sido caracterizada pelo aumento no número de equipamentos elétricos e como consequência um aumento no nível do campo eletromagnético (CEM) no ambiente. No entanto, os pesquisadores estão preocupados com os efeitos biológicos dos CEM de 50-60 Hz. O objetivo deste artigo é mostrar os efeitos do CEM de 60 Hz, 3 μT, nas concentrações hormonais e metabólicas de ratas prenhes, expostas duas horas por dia ao CEM, alimentadas pela Dieta Básica Regional (DBR) comparando com ratas submetidas às mesmas condições, mas alimentas com dieta padrão. Ratas prenhes expostas ao CEM de 60 Hz, 3 μT, durante a prenhez e alimentadas com a DBR apresentaram um aumento na liberação de glicose quando comparadas com o grupo alimentado pela DBR sem CEM. As ratas alimentadas pela DBR apresentaram uma diminuição nos níveis de insulina e cortisol quando comparadas com o grupo alimentado pela caseína. As concentrações de T3 e T4 apresentaram a maior variação entre os grupos. A relação T4:T3 foi muito exagerada no grupo alimentado pela DBR e exposto ao CEM quando comparado com os outros. Conclusão, os animais que foram submetidos à desnutrição e ao CEM sofreram uma diminuição na concentração sérica de T4 e T3 quando comparados com os animais bem nutridos e a relação T4:T3 no primeiro grupo foi quase 18 vezes a relação de T4:T3 no grupo bem nutrido.
Assuntos
Animais , Feminino , Gravidez , Ratos , Campos Eletromagnéticos/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/sangue , Desnutrição Proteico-Calórica/sangue , Hidrocortisona/sangue , Hidrocortisona/efeitos da radiação , Insulina/sangue , Insulina/efeitos da radiação , Ratos Wistar , Fatores de Tempo , Tiroxina/sangue , Tiroxina/efeitos da radiação , Tri-Iodotironina/sangue , Tri-Iodotironina/efeitos da radiaçãoRESUMO
The aim of the present study was to observe how the exposition of pregnant rats to an electromagnetic field (EMF), with frequency of 60 Hz, and a magnetic field of 3 µT for 2 hours per day and/or using the so-called Regional Basic Diet (RBD), influenced the somatic maturation in their offspring. Four groups were formed: Group A (casein), B (casein and EMF), C (RBD) and D (RBD and EMF). The diet manipulation occurred during pregnancy. The somatic maturation indexes - assessed daily between 12:00 AM and 2:00 PM - were: Eye Opening (EO), Auricle Opening (AO), Auditory Canal Opening (ACO), Low Incisor Eruption (LIE), and Upper Incisor Eruption (UIE). The association between EMF and deficient diet caused a delay in all Somatic Maturation Indexes (SMI) and the RBD caused delay only in the AO. Furthermore, the EMF caused delay in AO, ACO, LIE. In relation to the body weight, the EMF associated with the deficient diet caused change in the twenty-first day of life. The RBD, during pregnancy, caused lower body weight in the offspring in the first and third day of life. The body weight of the offspring whose mothers were fed casein and exposed to the EMF during pregnancy was lower in the third and sixth day of life. In conclusion, the EMF associated with under-nutrition caused delay in all SMI. In relation to the body weight, the EMF associated with under-nutrition caused a decrease in the body weight at the sixth day of life.
O objetivo deste estudo foi observar a influência do campo eletromagnético (CEM), com freqüência de 60Hz, campo magnético de 3 µT, durante 2 horas por dia, associado ou não à dieta básica regional (DBR) no desenvolvimento somático da prole. Quatro grupos foram formados: Grupo A (caseína), B (caseína e CEM), C (DBR) e D (DBR e CEM). A manipulação dietética ocorreu durante a prenhez. Os índices de maturação somática - Abertura dos Olhos (AO), Abertura do Pavilhão Auditivo (APA), Abertura do Conduto Auditivo (ACA), Erupção do Incisivo Inferior (EII), e Erupção do Incisivo Superior (EIS) - foram avaliados diariamente entre 12 e 14 horas. A associação entre o CEM e a dieta deficiente causou retardo em todos os índices de maturação somática (IMS) e a DBR causou retardo somente na APA. O CEM causou retardo na APA, ACA, EII. Em relação ao peso corporal, o CEM associado à dieta deficiente causou mudanças no 21º dia de vida. A DBR, durante a prenhez, causou diminuição do peso corporal dos filhotes no 1º e no 3º dia de vida. O peso corporal dos filhotes, cujas mães foram alimentadas pela caseína e expostas ao CEM, durante a prenhez, apresentaram uma diminuição no 3º e 6º dia de vida. Conclusão: o CEM, associado com a desnutrição, causou retardo em todos os IMS. Em relação ao peso corporal, o CEM, associado à desnutrição, causou uma diminuição no peso corporal no 6º dia de vida.
Assuntos
Animais , Feminino , Masculino , Gravidez , Ratos , Campos Eletromagnéticos/efeitos adversos , Desnutrição Proteico-Calórica/complicações , Distúrbios Somatossensoriais/etiologia , Efeitos Tardios da Exposição Pré-Natal , Ratos Wistar , Fatores de TempoRESUMO
Several databases and computational tools have been created with the aim of organizing, integrating and analyzing the wealth of information generated by large-scale sequencing projects of mycobacterial genomes and those of other organisms. However, with very few exceptions, these databases and tools do not allow for massive and/or dynamic comparison of these data. GenoMycDB (http://www.dbbm.fiocruz.br/GenoMycDB) is a relational database built for large-scale comparative analyses of completely sequenced mycobacterial genomes, based on their predicted protein content. Its central structure is composed of the results obtained after pair-wise sequence alignments among all the predicted proteins coded by the genomes of six mycobacteria: Mycobacterium tuberculosis (strains H37Rv and CDC1551), M. bovis AF2122/97, M. avium subsp. paratuberculosis K10, M. leprae TN, and M. smegmatis MC2 155. The database stores the computed similarity parameters of every aligned pair, providing for each protein sequence the predicted subcellular localization, the assigned cluster of orthologous groups, the features of the corresponding gene, and links to several important databases. Tables containing pairs or groups of potential homologs between selected species/strains can be produced dynamically by user-defined criteria, based on one or multiple sequence similarity parameters. In addition, searches can be restricted according to the predicted subcellular localization of the protein, the DNA strand of the corresponding gene and/or the description of the protein. Massive data search and/or retrieval are available, and different ways of exporting the result are offered. GenoMycDB provides an on-line resource for the functional classification of mycobacterial proteins as well as for the analysis of genome structure, organization, and evolution.
Assuntos
Bases de Dados Genéticas , Genes Bacterianos , Genoma Bacteriano , Mycobacterium/genética , Proteínas de Bactérias/genética , Mycobacterium/classificaçãoRESUMO
Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.
Assuntos
Colesterol/metabolismo , Eritrócitos/metabolismo , Proteínas Hemolisinas/farmacologia , Passiflora/química , Saponinas/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Eritrócitos/efeitos dos fármacos , Proteínas Hemolisinas/isolamento & purificação , Hemólise , Bicamadas Lipídicas/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta/química , Coelhos , Saponinas/isolamento & purificaçãoRESUMO
Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.
Assuntos
Animais , Coelhos , Colesterol/metabolismo , Eritrócitos/metabolismo , Proteínas Hemolisinas/farmacologia , Passiflora/química , Saponinas/farmacologia , Cromatografia Líquida de Alta Pressão , Eritrócitos/efeitos dos fármacos , Hemólise , Proteínas Hemolisinas/isolamento & purificação , Bicamadas Lipídicas/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta/química , Saponinas/isolamento & purificaçãoRESUMO
Doses of 60Co gamma radiation with 2.5; 5; 7.5; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 80; 160; 320 and 640 Gy were applied to 1, 080 snails Biomphalaria straminea, an intermediate host of Schistosoma mansoni, divided in groups containing 30 mollusks. In addition, 60 non irradiated snails were kept as control. Fifty percent of the population was kept in colonies (allowing cross fertilization) while the other half was maintained in sexual isolation (allowing self fertilization) and during one month their growth was observed through the daily measurement of the shell diameter. Results showed that after 20 Gy doses the growth in shell diameter of irradiated snails was greater than that of the control group after 30 days. At this dose the snail size was the greatest, among all isolated groups. The 80 Gy doses also induced the final shell diameter of isolated snails to be greater then that observed in the control groups. As this effect was most evident among the isolated snails, a possible hormonal role may have been involved in the observed phenomena, which is under investigation with the objective of identifying any future applications that this could have to schistosomiasis control.
Assuntos
Biomphalaria/crescimento & desenvolvimento , Biomphalaria/efeitos da radiação , AnimaisRESUMO
In Brazil, the most common etiological agent of American tegumentary leishmaniasis is Leishmania (Viannia) braziliensis. In general, diagnostic techniques envisage the visualization of the parasite, but that technique has a low sensitivity. The main purpose of the present work was to evaluate the PCR as a routine tool for the diagnosis of leishmaniasis. Biopsy specimens from cutaneous or mucosal lesions were taken from 230 individuals from areas where Leishmania is endemic: 216 patients who had a clinical picture suggestive of leishmaniasis and 14 individuals with cutaneous lesions due to other causes. Each specimen was processed for histopathologic examination, culture, touch preparation, and DNA isolation. Oligonucleotides that amplify the conserved region of the minicircle molecules of Leishmania were used in a hot-start PCR. While at least one conventional technique was positive for Leishmania for 62% (134 of 216) of the patients, PCR coupled to hybridization was positive for 94% (203 of 216) of the patients. The 14 patients whose clinical picture was not suggestive of leishmaniasis had negative results by all techniques. The impact of the PCR was striking in mucosal disease. While the disease in only 17% (4 of 24) of the patients could be diagnosed by conventional techniques, PCR was positive for 71% (17 of 24) of the patients. Hybridization showed that all cases of disease were caused by parasites belonging to the Viannia subgenus. Altogether, the results indicate that PCR is a valuable tool for the diagnosis of leishmaniasis on a routine basis and is likely to provide valuable epidemiological information about the disease in countries where it is endemic.
Assuntos
Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Animais , Biópsia , Brasil , Corantes , DNA de Protozoário/genética , DNA de Protozoário/isolamento & purificação , Humanos , Leishmaniose Cutânea/patologia , Pacientes Ambulatoriais , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Pele/patologia , População UrbanaRESUMO
Using a gonadoliberin (GnRH) receptor preparation from the bovine pituitaries, we purified the receptor approximately 14,000 fold as compared to the starting material, with a overall yield of about 40%. The binding capacity of a iodinated GnRH analog, used for radioreceptor assay, increased from 16 fmoles/mg of protein in the crude material to 225 pmoles/mg of protein in the final product. The affinity constant was not modified by the purification process and remained close to Ka = 10(10) M-1. Electrophoretic analysis of the purified preparation suggests an apparent molecular mass of about 60,000 Da for the receptor.
Assuntos
Adeno-Hipófise/análise , Receptores de Superfície Celular/isolamento & purificação , Animais , Bovinos , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Peso Molecular , Ensaio Radioligante , Receptores LHRHRESUMO
We have investigated the effect of the time of culture on cell number, cell content of LH, cell responsiveness to gonadotrophin releasing hormone (GnRH) and binding parameters of GnRH in rat anterior pituitary cells in culture. Although a decrease in the cell number was observed during the culture period, the cell content of LH remained unchanged. The receptor affinity (Ka) in acutely dispersed cells was 0.86 X 10(7) l/mol for [3H]GnRH and 1.36 X 10(10) l/mol for a highly potent agonist, [D-Ser(But)6]GnRH(1-9)nonapeptide-ethylamide (GnRH-A). The affinity and binding capacity (0.3 fmol/10(6) cells) for iodinated GnRH-A did not change significantly during the 6-day culture period. On the contrary, the values of Ka and binding capacity (257 fmol/10(6) cells) for tritiated GnRH decreased by about 50% between days 1 and 6 of culture. Our results suggest that 125I-labelled GnRH-A binds mostly to high-affinity and low-capacity receptor sites, while [3H]GnRH, which must be used at a higher concentration, also binds to low-affinity, high-capacity binding sites and is therefore useless for the measurement of GnRH receptor binding affinity and binding capacity. Since the biological response of the cells to GnRH increased with the time of culture, it is concluded that although GnRH action is receptor-mediated, binding capacity and biological activity are not necessarily correlated.
Assuntos
Hormônio Luteinizante/metabolismo , Adeno-Hipófise/metabolismo , Hormônios Liberadores de Hormônios Hipofisários/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Busserrelina/farmacologia , Contagem de Células , Células Cultivadas , Cinética , Masculino , Adeno-Hipófise/citologia , Adeno-Hipófise/efeitos dos fármacos , Hormônios Liberadores de Hormônios Hipofisários/farmacologia , Ratos , Ratos Endogâmicos , Receptores LHRH , Fatores de TempoRESUMO
The high-affinity gonadoliberin (GnRH) receptor contained in a membrane preparation from frozen bovine anterior pituitary glands has been solubilized in Triton X-100 and the binding properties of the solubilized product have been examined. The radioreceptor-binding assay, using the GnRH agonist [D-Ser(t-Bu)6] des-Gly10GnRH N-ethylamide (GnRH-A) as radioligand, demonstrated that the kinetics of association and dissociation, the binding constants, as well as the specificity of receptor were not altered in the solubilized receptor preparations. Affinity chromatography on a concanavalin A-Sepharose column, with elution of adsorbed material using a solution of alpha-methyl-D-mannoside, allowed a 33-fold purification of the receptor. The Ka of the receptor thus purified was of the same order as that of the starting material, although slightly higher values were found. Only about one-half of the total receptor activity applied to the column was retained in spite of several recyclings. The other half was found in the nonadsorbed fraction. It is postulated that the detergent-solubilized fraction contains two forms of the GnRH receptor. The nonadsorbed fraction probably contains a partially or totally deglycosylated form. It is possible that the detergent-solubilization process somewhat alters the physicochemical properties of a part of the GnRH receptor molecules. Electrophoretic analysis of the purified receptor preparations, with a subsequent GnRH-binding assay, suggests that the apparent molecular mass of the high-affinity GnRH receptor, or of its monomeric form, is approximately 60,000 Da.
Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Adeno-Hipófise/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Ligação Competitiva , Bovinos , Cinética , Peso Molecular , Receptores de Superfície Celular/isolamento & purificação , Receptores LHRH , SolubilidadeRESUMO
We have developed a microscaled method for the extraction and translation of mRNA from 2 x 10(5)-2 x 10(6) anterior pituitary cells. This method applied to a fraction of enriched gonadotrophs enabled us to confirm our previous results suggesting that (1) Rat LH subunits were synthesized in a cell-free system as precursors, from separate mRNAs; (2). The relative molecular mass of precursors, as determined by SDS-polyacrylamide gel electrophoresis, was 17-17,5 kD for LH alpha and 18,5-19 kD for LH beta. This procedure resulted in a 5-6 fold increase in the proportion of in vitro synthesized precursors in LH subunits.