RESUMO
Pathological α-synuclein (α-syn) overexpression and iron (Fe)-induced oxidative stress (OS) are involved in the death of dopaminergic neurons in Parkinson's disease (PD). We have previously characterized the role of triacylglycerol (TAG) formation in the neuronal response to Fe-induced OS. In this work we characterize the role of the α-syn variant A53T during Fe-induced injury and investigate whether lipid metabolism has implications for neuronal fate. To this end, we used the N27 dopaminergic neuronal cell line either untransfected (UT) or stably transfected with pcDNA3 vector (as a transfection control) or pcDNA-A53T-α-syn (A53T α-syn). The overexpression of A53T α-syn triggered an increase in TAG content mainly due to the activation of Acyl-CoA synthetase. Since fatty acid (FA) ß-oxidation and phospholipid content did not change in A53T α-syn cells, the unique consequence of the increase in FA-CoA derivatives was their acylation in TAG moieties. Control cells exposed to Fe-induced injury displayed increased OS markers and TAG content. Intriguingly, Fe exposure in A53T α-syn cells promoted a decrease in OS markers accompanied by α-syn aggregation and elevated TAG content. We report here new evidence of a differential role played by A53T α-syn in neuronal lipid metabolism as related to the neuronal response to OS.
Assuntos
Ferro/toxicidade , Neurônios/metabolismo , alfa-Sinucleína/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/genética , Gotículas Lipídicas/metabolismo , Mutação , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transfecção/métodos , Triglicerídeos/metabolismo , alfa-Sinucleína/genéticaRESUMO
Three-dimensional (3D) printing is an emerging technology for the fabrication of scaffolds to repair/replace damaged tissue/organs in tissue engineering. This paper presents our study on 3D printed alginate scaffolds treated with phosphate buffered saline (PBS) and polyethyleneimine (PEI) coating and their impacts on the surface morphology and cellular response of the printed scaffolds. In our study, sterile alginate was prepared by means of the freeze-drying method and then, used to prepare the hydrogel for 3D printing into calcium chloride, forming 3D scaffolds. Scaffolds were treated with PBS for a time period of two days and seven days, respectively, and PEI coating; then they were seeded with Schwann cells (RSC96) for the examination of cellular response (proliferation and differentiation). In addition, swelling and stiffness (Young's modulus) of the treated scaffolds was evaluated, while their surface morphology was assessed using scanning electron microscopy (SEM). SEM images revealed significant changes in scaffold surface morphology due to degradation caused by the PBS treatment over time. Our cell proliferation assessment over seven days showed that a two-day PBS treatment could be more effective than seven-day PBS treatment for improving cell attachment and elongation. While PEI coating of alginate scaffolds seemed to contribute to cell growth, Schwann cells stayed round on the surface of alginate over the period of cell culture. In conclusion, PBS-treatment may offer the potential to induce surface physical cues due to degradation of alginate, which could improve cell attachment post cell-seeding of 3D-printed alginate scaffolds.
RESUMO
Polysaccharides are substances that modify the biological response to several stressors. The present study investigated the antitumor activity of the soluble fraction of polysaccharides (SFP), extracted from cabernet franc red wine, in Walker-256 tumor-bearing rats. The monosaccharide composition had a complex mixture, suggesting the presence of arabinoglactans, mannans, and pectins. Treatment with SFP (30 and 60mg/kg, oral) for 14days significantly reduced the tumor weight and volume compared with controls. Treatment with 60mg/kg SFP reduced blood monocytes and neutrophils, reduced the tumor activity of N-acetylglucosaminidase, myeloperoxidase, and nitric oxide, increased blood lymphocytes, and increased the levels of tumor necrosis factor α (TNF-α) in tumor tissue. Treatment with SFP also induced the expression of the cell necroptosis-related genes Rip1 and Rip3. The antineoplastic effect of SFP appears to be attributable to its action on the immune system by controlling the tumor microenvironment and stimulating TNF-α production, which may trigger the necroptosis pathway.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Neoplasias Experimentais/tratamento farmacológico , Polissacarídeos/farmacologia , Vinho , Animais , Antineoplásicos/química , Polissacarídeos/química , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Tuberculosis (TB) is one of the most important causes of mortality and morbidity due to infectious diseases. BCG, the vaccine in use, is not fully protective against TB. In a previous study, we have shown that proteoliposomes (outer membrane extracts), obtained from BCG (PLBCG) were able to induce humoral immune responses against Mycobacterium tuberculosis (Mtb) antigens. With the objective to evaluate the protective capability of PLBCG alone or as a booster with BCG, a murine model of progressive pulmonary TB was used. Animals immunized with PLBCG adjuvanted with alum (PLBCG-Al) showed similar protection to that conferred by BCG. The group immunized with PLBCG-Al as a booster to BCG gave superior protection than BCG as evidenced by a reduction of bacterial load in lungs 2 months after infection with Mtb. Animals immunized with BCG, PLBCG-Al and this formulation as a booster of BCG, showed a significant decrease of tissue damage (percentage of pneumonic area/lung) compared with non-immunized animals. These results demonstrate that immunization with PLBCG-Al alone or as a booster to BCG induce appropriate protection against challenge with Mtb in mice and support the future evaluation of PLBCG as a promising vaccine candidate against Mtb.
Assuntos
Mycobacterium bovis/imunologia , Proteolipídeos/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Carga Bacteriana , Modelos Animais de Doenças , Pulmão/microbiologia , Masculino , Camundongos Endogâmicos BALB C , Mycobacterium bovis/química , Mycobacterium tuberculosis/isolamento & purificação , Proteolipídeos/administração & dosagem , Proteolipídeos/isolamento & purificação , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/isolamento & purificaçãoRESUMO
The radioprotective potential of histamine on healthy tissue has been previously demonstrated. The aims of this work were to investigate the combinatorial effect of histamine or its receptor ligands and gamma radiation in vitro on the radiobiological response of 2 breast cancer cell lines (MDA-MB-231 and MCF-7), to explore the potential molecular mechanisms of the radiosensitizing action and to evaluate the histamine-induced radiosensitization in vivo in a triple negative breast cancer model. Results indicate that histamine significantly increased the radiosensitivity of MDA-MB-231 and MCF-7 cells. This effect was mimicked by the H1R agonist 2-(3-(trifluoromethyl)phenyl)histamine and the H4R agonists (Clobenpropit and VUF8430) in MDA-MB-231 and MCF-7 cells, respectively. Histamine and its agonists enhanced radiation-induced oxidative DNA damage, DNA double-strand breaks, apoptosis and senescence. These effects were associated with increased production of reactive oxygen species, which correlated with the inhibition of catalase, glutathione peroxidase and superoxide dismutase activities in MDA-MB-231 cells. Histamine was able also to potentiate in vivo the anti-tumoral effect of radiation, increasing the exponential tumor doubling time. We conclude that histamine increased radiation response of breast cancer cells, suggesting that it could be used as a potential adjuvant to enhance the efficacy of radiotherapy.
Assuntos
Neoplasias da Mama/metabolismo , Histamina/metabolismo , Tolerância a Radiação , Radiação Ionizante , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Linhagem Celular Tumoral , Senescência Celular/efeitos dos fármacos , Senescência Celular/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Feminino , Histamina/farmacologia , Humanos , Células MCF-7 , Oxirredução , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/efeitos da radiação , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
In the present study, we investigated the effects of lesions of A2 neurons of the commissural nucleus of the solitary tract (cNTS) alone or combined with the blockade of angiotensinergic mechanisms on the recovery of arterial pressure (AP) to hemorrhage in conscious rats. Male Holtzman rats (280-320g) received an injection of anti-dopamine-beta-hydroxylase-saporin (12.6ng/60nl; cNTS/A2-lesion, n=28) or immunoglobulin G (IgG)-saporin (12.6ng/60nl, sham, n=24) into the cNTS and 15-21days later had a stainless steel cannula implanted in the lateral ventricle. After 6days, rats were submitted to hemorrhage (four blood withdrawals, 2ml/300g of body weight every 10min). Both cNTS/A2-lesioned and sham rats had similar hypotension to hemorrhage (-62±7 and -73±7mmHg, respectively), however cNTS/A2-lesioned rats rapidly recovered from hypotension (-5±3mmHg at 30min), whereas sham rats did not completely recover until the end of the recording (-20±3mmHg at 60min). Losartan (angiotensin type 1 receptor antagonist) injected intracerebroventricularly (100µg/1µl) or intravenously (i.v.) (10mg/kg of body weight) impaired the recovery of AP in cNTS/A2-lesioned rats (-24±6 and -35±7mmHg at 30min, respectively). In sham rats, only i.v. losartan affected the recovery of AP (-39±6mmHg at 60min). The results suggest that lesion of the A2 neurons in the cNTS facilitates the activation of the angiotensinergic pressor mechanisms in response to hemorrhage.
Assuntos
Neurônios Adrenérgicos/metabolismo , Angiotensina II/metabolismo , Hemorragia/metabolismo , Núcleo Solitário/patologia , Neurônios Adrenérgicos/patologia , Animais , Hemorragia/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Núcleo Solitário/metabolismoRESUMO
Pseudomonas aeruginosa is an important opportunistic human pathogen that causes severe infections in immunocompromised patients and also in cystic fibrosis patients. The aim of this work was to study if a bovine serum albumin nanoparticles with entrapped antigens extracted from P. aeruginosa would be able to protect mice from nasal infection by this pathogen. Mice were immunized via the subcutaneous route using P. aeruginosa antigens, empty nanoparticles or nanoparticles with entrapped P. aeruginosa antigens on days 0, 7 and 14. The total IgG antibody production and specific IgG1 and IgG2a titer were measured by ELISA. Immunized mice were challenged with live P. aeruginosa and their lungs were collected for histopathology studies. Our data showed that NPPa-vaccinated mice presented a high anti-Pseudomonas IgG1 and a low IgG2a antibody titles and decreased inflammatory signs, with significant reduction in intensity and concentration of inflammatory cells, lower hemorrhagic, edema and hyperemia signs in the lungs of challenge mice with live P. aeruginosa if compared to the other groups. Therefore, this formulation is able to induce a functional response in an animal model of infection and thereby is a promising platform for P. aeruginosa vaccines.
Assuntos
Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Pulmão/patologia , Nanopartículas , Infecções por Pseudomonas/prevenção & controle , Soroalbumina Bovina/administração & dosagem , Animais , Anticorpos Antibacterianos/sangue , Imunoglobulina G/sangue , Inflamação/microbiologia , Inflamação/patologia , Pulmão/microbiologia , Masculino , Camundongos , Infecções por Pseudomonas/imunologiaRESUMO
Hypoxic insults during the perinatal period lead to motor and cognitive impairments that later appear during childhood. In the adult brain, hypoxic events often lead to necrotic neuronal death, depending on the region and intensity of the event. During development an active apoptotic cell death occurs and could be an important variable affecting the hypoxic insult outcome. In the present work we performed a comparative study, in a chick embryo model, of the phenotypes and molecular markers exhibited during developmental and hypoxic cell death (HxCD). Ultrastructural analysis of optic tectum cells of embryos subjected to hypoxia (8% O2, 60 min) revealed a clear apoptotic morphology that did not differ from the one exhibited during developmental cell death. Integrity of plasma membrane, condensation of chromatin in round well-defined bodies, and gradual shrinkage of the cell are all hallmarks of the apoptotic process and were present in both control and hypoxic cells. To elucidate if hypoxic and developmental cell deaths share a common mechanism we evaluated the activation of both intrinsic and extrinsic apoptotic pathways. A basal cleavage of caspase-9 and cytochrome c release was observed by co-immunofluorescence in control embryos, but hypoxic insult significantly increased the incidence of this colocalization. Caspase-8 cleavage remained unchanged after the hypoxic insult, suggesting that the extrinsic pathway would not be involved in hypoxic death. We also observed a significant decrease of Akt activation immediately after hypoxia, possibly facilitating the later release of cytochrome c. In addition we analyzed the influence of retinal ganglion cells (RGC) in neuronal survival. Transection of RGC fibers at embryonic day (ED) 3 did not induce any change in developmental and HxCD at ED12. In conclusion, our findings demonstrate that a hypoxic insult in the developing brain triggers the same apoptotic pathway as the active developmental death.
Assuntos
Apoptose/fisiologia , Hipóxia/patologia , Colículos Superiores/patologia , Animais , Western Blotting , Embrião de Galinha , Galinhas , Imunofluorescência , Marcação In Situ das Extremidades Cortadas , Microscopia Eletrônica de Transmissão , Colículos Superiores/embriologia , Colículos Superiores/metabolismoRESUMO
Large procyanidins (more than three subunits) are not absorbed at the gastrointestinal tract but could exert local effects through their interactions with membranes. We previously showed that hexameric procyanidins (Hex), although not entering cells, interact with membranes modulating cell signaling and fate. This paper investigated if Hex, as an example of large procyanidins, can selectively interact with lipid rafts which could in part explain its biological actions. This mechanism was studied in both synthetic membranes (liposomes) and Caco-2 cells. Hex promoted Caco-2 cell membrane rigidification and dehydration, effects that were abolished upon cholesterol depletion with methyl-ß-cyclodextrin (MCD). Hex prevented lipid raft structure disruption induced by cholesterol depletion/redistribution by MCD or sodium deoxycholate. Supporting the involvement of cholesterol-Hex bonding in Hex interaction with lipid rafts, the absence of cholesterol markedly decreased the capacity of Hex to prevent deoxycholate- and Triton X-100-mediated disruption of lipid raft-like liposomes. Stressing the functional relevance of this interaction, Hex mitigated lipid raft-associated activation of the extracellular signal-regulated kinases (ERK) 1/2. Results support the capacity of a large procyanidin (Hex) to interact with membrane lipid rafts mainly through Hex-cholesterol bondings. Procyanidin-lipid raft interactions can in part explain the capacity of large procyanidins to modulate cell physiology.
Assuntos
Colesterol/metabolismo , Microdomínios da Membrana/metabolismo , Proantocianidinas/metabolismo , Western Blotting , Células CACO-2 , Detergentes , Ativação Enzimática , Humanos , Lipossomos , Sistema de Sinalização das MAP Quinases , Transdução de SinaisRESUMO
Compression of spinal roots is an important medical problem, which may arise from intervertebral disc herniation, tumor growth or as a result of high energy accidents. Differently from avulsion, root crushing maintains the central/peripheral nervous system (CNS/PNS) connection, although the axons are axotomized and motoneurons degenerate. Such neuronal death may decrease and delay motor function recovery. In the present study we have investigated the neuroprotective effects of mesenchymal stem cell (MSC) therapy following such proximal lesions. Motor recovery and synaptic stabilization were analyzed by the use of morphological and functional approaches. For that, crushing the ventral roots at L4, L5 and L6 was unilaterally performed in Lewis rats. Four weeks after injury, an increased motoneuron survival was observed in the MSC-treated group, coupled with a smaller decrease of inputs at the motoneuron surface and nearby neuropil, seen by synaptophysin and synapsin immunolabeling and decreased astrogliosis, seen by GFAP immunolabeling. In this sense, MSC-treated group displayed a significant preservation of GABAergic terminals, indicating a possible neuroprotection to glutamate excitotoxicity. Motor function recovery was acutely improved in MSC-treated group as compared to Dulbeco's modified eagle medium (DMEM)-treated. Overall, we provide evidence that ventral root crushing (VRC), although milder than avulsion, results in significant loss of motoneurons (~51%) that can be reduced by MSC administration within the spinal cord. Such treatment also improves the number of synapses immunoreactive against molecules present in inhibitory inputs. Also, an increased number of regenerated axons was obtained in the MSC-treated group, in comparison to the DMEM-treated control. Overall, MSC therapy acutely improved limb strength and gait coordination, indicating a possible clinical application of such treatment following proximal lesions at the CNS/PNS interface.
Assuntos
Axotomia , Transplante de Células-Tronco Mesenquimais , Neurônios Motores/fisiologia , Regeneração Nervosa/fisiologia , Medula Espinal/citologia , Raízes Nervosas Espinhais/fisiologia , Sinapses/fisiologia , Animais , Sobrevivência Celular , Células Cultivadas , Feminino , Citometria de Fluxo , Marcha/fisiologia , Imuno-Histoquímica , Força Muscular , Compressão Nervosa , Neuroglia/fisiologia , Ratos , Ratos Endogâmicos Lew , Recuperação de Função Fisiológica , Nervo Isquiático/citologia , Nervo Isquiático/fisiologiaRESUMO
It has been reported that serine peptidase activities of Trypanosoma cruzi play crucial roles in parasite dissemination and host cell invasion and therefore their inhibition could affect the progress of Chagas disease. The present study investigates the interference of the Stichodactyla helianthus Kunitz-type serine protease inhibitor (ShPI-I), a 55-amino acid peptide, in T. cruzi serine peptidase activities, parasite viability, and parasite morphology. The effect of this peptide was also studied in Leishmania amazonensis promastigotes and it was proved to be a powerful inhibitor of serine proteases activities and the parasite viability. The ultrastructural alterations caused by ShPI-I included vesiculation of the flagellar pocket membrane and the appearance of a cytoplasmic vesicle that resembles an autophagic vacuole. ShPI-I, which showed itself to be an important T. cruzi serine peptidase inhibitor, reduced the parasite viability, in a dose and time dependent manner. The maximum effect of peptide on T. cruzi viability was observed when ShPI-I at 1×10(-5)M was incubated for 24 and 48h which killed completely both metacyclic trypomastigote and epimastigote forms. At 1×10(-6)M ShPI-I, in the same periods of time, reduced parasite viability about 91-95% respectively. Ultrastructural analysis demonstrated the formation of concentric membranar structures especially in the cytosol, involving organelles and small vesicles. Profiles of endoplasmic reticulum were also detected, surrounding cytosolic vesicles that resembled autophagic vacuoles. These results suggest that serine peptidases are important in T. cruzi physiology since the inhibition of their activity killed parasites in vitro as well as inducing important morphological alterations. Protease inhibitors thus appear to have a potential role as anti-trypanosomatidal agents.
Assuntos
Antiprotozoários/farmacologia , Produtos Biológicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Anêmonas-do-Mar/química , Serpinas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antiprotozoários/isolamento & purificação , Organismos Aquáticos/química , Produtos Biológicos/isolamento & purificação , Doença de Chagas/parasitologia , Relação Dose-Resposta a Droga , Humanos , Leishmania/citologia , Leishmania/efeitos dos fármacos , Leishmania/fisiologia , Microscopia Eletrônica , Organelas/ultraestrutura , Serpinas/isolamento & purificação , Trypanosoma cruzi/citologia , Trypanosoma cruzi/fisiologiaRESUMO
Iron accumulation and oxidative stress are hallmarks of retinas from patients with age-related macular degeneration (AMD). We have previously demonstrated that iron-overloaded retinas are a good in vitro model for the study of retinal degeneration during iron-induced oxidative stress. In this model we have previously characterized the role of cytosolic phospholipase A2 (cPLA2) and calcium-independent isoform (iPLA2). The aim of the present study was to analyze the implications of Group V secretory PLA2 (sPLA2), another member of PLA2 family, in cyclooxygenase (COX)-2 and nuclear factor kappa B (NF-κB) regulation. We found that sPLA2 is localized in cytosolic fraction in an iron concentration-dependent manner. By immunoprecipitation (IP) assays we also demonstrated an increased association between Group V sPLA2 and COX-2 in retinas exposed to iron overload. However, COX-2 activity in IP assays was observed to decrease in spite of the increased protein levels observed. p65 (RelA) NF-κB levels were increased in nuclear fractions from retinas exposed to iron. In the presence of ATK (cPLA2 inhibitor) and YM 26734 (sPLA2 inhibitor), the nuclear localization of both p65 and p50 NF-κB subunits was restored to control levels in retinas exposed to iron-induced oxidative stress. Membrane repair mechanisms were also analyzed by studying the participation of acyltransferases in phospholipid remodeling during retinal oxidation stress. Acidic phospholipids, such as phosphatidylinositol (PI) and phosphatidylserine (PS), were observed to show an inhibited acylation profile in retinas exposed to iron while phosphatidylethanolamine (PE) showed the opposite. The use of PLA2 inhibitors demonstrated that PS is actively deacylated during iron-induced oxidative stress. Results from the present study suggest that Group V sPLA2 has multiple intracellular targets during iron-induced retinal degeneration and that the specific role of sPLA2 could be related to inflammatory responses by its participation in NF-κB and COX-2 regulation.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Fosfolipases A2 do Grupo V/fisiologia , Degeneração Macular/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Retina/efeitos dos fármacos , Acetilação , Acetiltransferases/metabolismo , Animais , Western Blotting , Bovinos , Citosol/metabolismo , Eletroforese em Gel de Poliacrilamida , Inibidores Enzimáticos/farmacologia , Compostos Ferrosos/toxicidade , Fosfolipases A2 do Grupo V/antagonistas & inibidores , Sobrecarga de Ferro/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositóis/metabolismo , Fosfatidilserinas/metabolismo , Fosfolipases A/metabolismo , Fosfolipases A/fisiologia , Retina/metabolismoRESUMO
O Fator Capacidade de Fósforo (FCP) é definido pela razão de equilíbrio entre o fator quantidade de P (Q) e o fator intensidade (I) e representa uma medida da capacidade do solo em manter um determinado nível de P em solução. As características e o teor dos constituintes minerais da fração argila são responsáveis por uma maior ou menor FCP, interferindo nas relações solo-planta. Por outro lado, o pH do solo tem, em alguns casos, mostrado-se com efeito na adsorção e, em outros, com pequena e não consistente alteração na Capacidade Máxima de Adsorção de P (CMAP). Objetivou-se, neste trabalho, determinar o FCP de solos mineralogicamente diferentes em Pernambuco; correlacionar características físicas e químicas dos solos com o FCP; e avaliar o efeito do pH na CMAP. Amostras subsuperficiais de quatro solos, mineralogicamente diferentes, foram caracterizadas química e fisicamente e determinado o FCP. Essas amostras foram corrigidas com CaCO3 e MgCO3 na proporção 4:1 e incubadas por 30 dias, com exceção do Vertissolo. Determinou-se a CMAP antes e após a correção dos solos. O experimento consistiu de um fatorial 4 x 2 (quatro solos com e sem correção), distribuídos em blocos ao acaso, com três repetições. As características dos solos que melhor refletiram o FCP foram o P remanescente (P-rem) e a CMAP. Independentemente dos constituintes mineralógicos da fração argila, solos com elevados teores de alumínio apresentaram aumento da CMAP com a correção. A energia de adsorção (EA) nos solos corrigidos foi, em média, significativamente menor, independentemente do solo.
Phosphate Maximum Capacity (FCP) is defined by the ratio of equilibrium between the amount of factor P (Q) and factor intensity (I) and represents a measure of the soil ability to maintain a certain level of P in solution. The characteristics and content of the constituents of clay minerals are responsible for a greater or lesser FCP, interfering in soil-plant relations. Moreover, the soil pH has affected adsorption, and in other cases, it has shown small and inconsistent change in the maximum adsorption capacity of P (CMAP). Thus, this study aimed to determine the different FCP soil mineralogy in Pernambuco; to correlate physical and chemical characteristics of soils with PBC and to evaluate the effect of pH on the CMAP. Subsurface soil samples from four different soils were characterized chemically and physically determined, and the PBC was determined. These samples were corrected with CaCO3 and MgCO3 in a 4:1 ratio and incubated for 30 days, except the Vertisol. The CMAP was determined before and after correction of the soil. The experiment consisted of a 4 x 2 factorial (four soils with and without correction), distributed in randomized blocks with three replicates. Soil characteristics that best reflected the PBC were the remaining P (P-rem) and MPAC. Regardless of the constituents of clay mineralogy, soil with high aluminum levels had increased CMAP after correction. The energy of adsorption (EA) in the limed soils was on average significantly lower, regardless of the soil.
RESUMO
The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1 percent sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1 percent SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.
O presente estudo descreve o desenvolvimento e a validação de método de dissolução para comprimidos revestidos de carvedilol. O teste de dissolução foi efetuado utilizando-se o aparelho para dissolução TDT-06T. Com base nas condições fisiológicas do organismo, utilizou-se ácido clorídrico 0,1 N como meio de dissolução e a liberação foi monitorada por 2 horas para se verificar o padrão de liberação imediata do fármaco em condições de pH baixo, seguidas por pH 6,8 em tampão cítrico-fosfato por 22 horas, para simular o padrão de liberação controlada no intestino. Avaliou-se a influência da velocidade de rotação e a concentração de tensoativo no meio. As amostras foram analisadas por método espectrofotométrico UV-visível validado, em 286 nm. O laurilsulfato sódico a 1 por cento (SLS) mostrou-se ótimo para aumentar a solubilidade do carvedilol em pH 6,8 em tampão cítrico-fosfato. A análise da variância não mostrou diferença significativa entre os resultados obtidos a 50 e a 100 rpm. O método da dissolução discriminante foi desenvolvido com sucesso para os comprimidos revestidos de carvedilol. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo I a 100 rpm, contendo 1000 mL de HCL 0,1 N por 2 horas, seguido de pH 6,8 com tampão cítrico-fosfato, com 1 por cento de SLS por 22 horas a 37,0 ± 0,5 ºC. Amostras foram analisadas por método espectrofotométrico e validadas pelas normas ICH.
Assuntos
Comprimidos com Revestimento Entérico/análise , Estudo de Validação , Dissolução/métodos , Dodecilsulfato de Sódio/farmacocinética , Ácido Clorídrico/farmacocinéticaRESUMO
SUMMARY The development of fresh mouse embryos in Modified PBS without adding C02 was compared to the development in Modified Whitten supplemented with 5% de C02 in order to establish a parameter to assess the viability after thawing. One thousand and four hundred and fifty eight morulae were collected from Strain CF1 Swiss Albino Mus musculus females which had been previously superovulated with 6-8UI of PMSG and 6-8UI of HCG 48h apart. One thousand and fifty one morulae were cultured in Modified PBS + 20% FCS, at 37°C and 95% of humidity. The others 407 were cultured in Modified Whitten's medium + 3% BSA, at 37 °C, 95% of humidity and 5% of C02. At the evaluation, performed after 24h of culture, were considered developed the embryos that reached early blastocyst, expanded blastocyst, hatching blastocyst and hatched blastocyts stages. After 48h of culture were considered developed the embryos that reached at least the expanded blastocyst stage. The results obtained after 24h (87.9 and 89.4%) and 48h of culture (95.2 and 93.8%) in PBS and Whitten, respectively, were similar (p 0,05).
RESUMO A fim de estabelecer um parâmetro para a avaliação da viabilidade após o descongelamento, os resultados do cultivo de embriões frescos de camundongos, no meio PBS Modificado sem a adição de C02, foram comparados aos resultados obtidos após o cultivo no meio de Whitten Modificado em atmosfera com 5% de C02. Foram coletadas 1458 mórulas provenientes de fêmeas Mus musculus da cepa Suíço Albina CF 1, previamente superovuladas com 6-8UI de eCG e 6-8UI de HCG, com intervalo de 48 horas. Destas, 1051 foram cultivadas em PBS Modificado acrescido de 20% de SFB, a 37°C e 95% de umidade. As restantes 407 foram cultivadas no meio de Whitten Modificado, acrescido de 3% de BSA, a 37°C, 95% de umidade e 5% de C02. As avaliações foram realizadas com 24h de cultivo, sendo considerados os embriões que atingiram os estágios de blastocisto inicial (Bi), blastocisto (Bl), blastocisto expandido (Bx), blastocisto em eclosão (Bh) ou blastocisto eclodido (Be), e após 48h de cultivo os que atingiram pelo menos o estágio de blastocisto expandido. Os resultados obtidos após 24h (87,9 e 89,4%) e após 48h de cultivo (95,1 e 93,8%) em PBS e Whitten respectivamente, não apresentaram diferenças estatisticamente significativas (p 0,05).
RESUMO
SUMMARY The development of fresh mouse embryos in Modified PBS without adding C02 was compared to the development in Modified Whitten supplemented with 5% de C02 in order to establish a parameter to assess the viability after thawing. One thousand and four hundred and fifty eight morulae were collected from Strain CF1 Swiss Albino Mus musculus females which had been previously superovulated with 6-8UI of PMSG and 6-8UI of HCG 48h apart. One thousand and fifty one morulae were cultured in Modified PBS + 20% FCS, at 37°C and 95% of humidity. The others 407 were cultured in Modified Whitten's medium + 3% BSA, at 37 °C, 95% of humidity and 5% of C02. At the evaluation, performed after 24h of culture, were considered developed the embryos that reached early blastocyst, expanded blastocyst, hatching blastocyst and hatched blastocyts stages. After 48h of culture were considered developed the embryos that reached at least the expanded blastocyst stage. The results obtained after 24h (87.9 and 89.4%) and 48h of culture (95.2 and 93.8%) in PBS and Whitten, respectively, were similar (p 0,05).
RESUMO A fim de estabelecer um parâmetro para a avaliação da viabilidade após o descongelamento, os resultados do cultivo de embriões frescos de camundongos, no meio PBS Modificado sem a adição de C02, foram comparados aos resultados obtidos após o cultivo no meio de Whitten Modificado em atmosfera com 5% de C02. Foram coletadas 1458 mórulas provenientes de fêmeas Mus musculus da cepa Suíço Albina CF 1, previamente superovuladas com 6-8UI de eCG e 6-8UI de HCG, com intervalo de 48 horas. Destas, 1051 foram cultivadas em PBS Modificado acrescido de 20% de SFB, a 37°C e 95% de umidade. As restantes 407 foram cultivadas no meio de Whitten Modificado, acrescido de 3% de BSA, a 37°C, 95% de umidade e 5% de C02. As avaliações foram realizadas com 24h de cultivo, sendo considerados os embriões que atingiram os estágios de blastocisto inicial (Bi), blastocisto (Bl), blastocisto expandido (Bx), blastocisto em eclosão (Bh) ou blastocisto eclodido (Be), e após 48h de cultivo os que atingiram pelo menos o estágio de blastocisto expandido. Os resultados obtidos após 24h (87,9 e 89,4%) e após 48h de cultivo (95,1 e 93,8%) em PBS e Whitten respectivamente, não apresentaram diferenças estatisticamente significativas (p 0,05).