Centro Universitario do Norte

Manaus, Brazil

Centro Universitario do Norte

Manaus, Brazil
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Rocha E Silva L.F.,Laboratorio Da Gerencia Of Malaria | Rocha E Silva L.F.,University Estadual Do Amazonas | Rocha E Silva L.F.,Centro Universitario Do Norte | Da Silva Pinto A.C.,National Institute of Amazonian Research | And 11 more authors.
Phytotherapy Research | Year: 2011

4-Nerolidylcatechol (4-NC) isolated from Piper peltatum L. (Piperaceae) was evaluated for in vitro antiplasmodial activity against Plasmodium falciparum (cultures of both standard CQR (K1) and CQS (3D7) strains and two Amazonian field isolates) and for in vivo antimalarial activity using the Plasmodium berghei-murine model. 4-NC exhibits significant in vitro and moderate in vivo antiplasmodial activity. 4-NC administered orally and subcutaneously at doses of 200, 400 and 600 mg/kg/day suppressed the growth of P. berghei by up to 63% after four daily treatments (days 1-4). Also, 4-NC exhibited important in vitro antiplasmodial activity against both standard and field P. falciparum strains in which 50% inhibition of parasite growth (IC 50) was produced at concentrations of 0.05-2.11 μg/mL and depended upon the parasite strain. Interestingly, healthy (non-infected) mice that received 4-NC orally presented (denatured) blood plasma which exhibited significant in vitro activity against P. falciparum. This is evidence that mouse metabolism allows 4-NC or active metabolites to enter the blood. Further chemical and pharmacological studies are necessary to confirm the potential of 4-NC as a new antimalarial prototype. Copyright © 2011 John Wiley & Sons, Ltd.


Lima R.B.S.,National Institute of Amazonian Research | Lima R.B.S.,Federal University of Amazonas | Lima R.B.S.,Centro Universitario Do Norte | Rocha Silva L.F.,National Institute of Amazonian Research | And 14 more authors.
Malaria Journal | Year: 2015

Background: The anti-malarials quinine and artemisinin were isolated from traditionally used plants (Cinchona spp. and Artemisia annua, respectively). The synthetic quinoline anti-malarials (e.g. chloroquine) and semi-synthetic artemisinin derivatives (e.g. artesunate) were developed based on these natural products. Malaria is endemic to the Amazon region where Plasmodium falciparum and Plasmodium vivax drug-resistance is of concern. There is an urgent need for new anti-malarials. Traditionally used Amazonian plants may provide new treatments for drug-resistant P. vivax and P. falciparum. Herein, the in vitro and in vivo antiplasmodial activity and cytotoxicity of medicinal plant extracts were investigated. Methods: Sixty-nine extracts from 11 plant species were prepared and screened for in vitro activity against P. falciparum K1 strain and for cytotoxicity against human fibroblasts and two melanoma cell lines. Median inhibitory concentrations (IC50) were established against chloroquine-resistant P. falciparum W2 clone using monoclonal anti-HRPII (histidine-rich protein II) antibodies in an enzyme-linked immunosorbent assay. Extracts were evaluated for toxicity against murine macrophages (IC50) and selectivity indices (SI) were determined. Three extracts were also evaluated orally in Plasmodium berghei-infected mice. Results: High in vitro antiplasmodial activity (IC50 = 6.4-9.9 μg/mL) was observed for Andropogon leucostachyus aerial part methanol extracts, Croton cajucara red variety leaf chloroform extracts, Miconia nervosa leaf methanol extracts, and Xylopia amazonica leaf chloroform and branch ethanol extracts. Paullinia cupana branch chloroform extracts and Croton cajucara red variety leaf ethanol extracts were toxic to fibroblasts and or melanoma cells. Xylopia amazonica branch ethanol extracts and Zanthoxylum djalma-batistae branch chloroform extracts were toxic to macrophages (IC50 = 6.9 and 24.7 μg/mL, respectively). Andropogon leucostachyus extracts were the most selective (SI >28.2) and the most active in vivo (at doses of 250 mg/kg, 71 % suppression of P. berghei parasitaemia versus untreated controls). Conclusions: Ethnobotanical or ethnopharmacological reports describe the anti-malarial use of these plants or the antiplasmodial activity of congeneric species. No antiplasmodial activity has been demonstrated previously for the extracts of these plants. Seven plants exhibit in vivo and or in vitro anti-malarial potential. Future work should aim to discover the anti-malarial substances present. © 2015 Lima et al.


Da Silva Barboza R.,Federal University of Pernambuco | Lins R.D.,Federal University of Pernambuco | De A. Barros D.,University of the State of Amazonas | Da F. De Lira E.,Centro Universitario Do Norte
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

Text highlighting is often used to emphasize parts of a document for some reason. As highlighting is a personal choice of the reader, it can be seen as physically "damaging" the original document. A recent paper shows how to remove felt-pen highlighting in monochromatic documents with a white paper background. This paper generalizes that result to filter out highlighting in monochromatic documents with non-white background due to paper natural aging. © 2013 Springer-Verlag.


e Silva L.F.R.,National Institute of Amazonian Research | e Silva L.F.R.,Federal University of Amazonas | e Silva L.F.R.,Centro Universitario do Norte | Lima E.S.,Federal University of Amazonas | And 13 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2013

Tachia sp. are used as antimalarials in the Amazon Region and in vivo antimalarial activity of a Tachia sp. has been previously reported. Tachia grandiflora Maguire and Weaver is an Amazonian antimalarial plant and herein its cytotoxicity and antimalarial activity were investigated. Spectral analysis of the tetraoxygenated xanthone decussatin and the iridoid aglyone amplexine isolated, respectively, from the chloroform fractions of root methanol and leaf ethanol extracts was performed. In vitro inhibition of the growth of Plasmodium falciparum Welch was evaluated using optical microscopy on blood smears. Crude extracts of leaves and roots were inactive in vitro. However, chloroform fractions of the root and leaf extracts [half-maximal inhibitory concentration (IC50) = 10.5 and 35.8 μg/mL, respectively] and amplexine (IC50 = 7.1 μg/mL) were active in vitro. Extracts and fractions were not toxic to type MRC-5 human fibroblasts (IC50 > 50 μg/mL). Water extracts of the roots of T. grandiflora administered by mouth were the most active extracts in the Peters 4-day suppression test in Plasmodium berghei-infected mice. At 500 mg/kg/day, these extracts exhibited 45-59% inhibition five to seven days after infection. T. grandiflora infusions, fractions and isolated substance have potential as antimalarials.


Pedrett M.D.S.,Federal University of Amazonas | Moreira S.C.,Centro Universitario do Norte
International Archives of Otorhinolaryngology | Year: 2012

Introduction: The cochlear implant is a device that is intended to substitute for the function of cochlear hair cells, electrically stimulate auditory nerve fibers, and contribute to the perception of speech sounds. However, the surgical procedure alone is not enough for the user to achieve favorable results in habilitation/rehabilitation. Objective: To characterize the patients from Manaus who have received cochlear implants based on the criteria for surgery. Methods: We conducted a retrospective cross-sectional study of 15 cases and recorded etiological aspects of deafness, age, gender, duration of implant use, use of hearing aids, and participation in individual therapy. Data were recorded in a protocol designed specifically for this purpose. All patients were natives of Manaus. Results: The leading etiological aspect was ototoxicity associated with prematurity in newborns undergoing treatment in the neonatal intensive care unit. The age at surgery is carefully observed in the evaluation of implant centers, as well as if the candidate is pre-or post-lingual. In this study, 73% of patients were pre-lingual and did not benefit from hearing aids. As to the degree and type of hearing loss, 93% had audiological reports indicating profound bilateral sensorineural hearing loss and 7% had severe bilateral sensorineural hearing loss. This latter finding confirmed one of the basic principles of implant placement. Conclusion: This study allowed us to verify that there are reduced number of cochlear implant recipients in Manaus, but they have met the criteria required by implant centers located in other states of Brazil.


Correia M.R.D.,Centro Universitario do Norte | de Araujo R.L.C.,Federal University of Amazonas
Revista Brasileira de Geofisica | Year: 2012

The HSS (Hyperspectral Scanner System) was evaluated for characterization and spatialization of soils in Manaus, AM, Brazil, with 3 meter resolution images. The images (37 bands between 0,43 and 2,37μm) were converted from radiance values to surface reflectance using the Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) applicative, based on the MODTRAN +4 (Moderate Resolution Transmittance) a radioactive transfer model. Preceding collection of soil samples, the main soil classes were identified through the SAM (Spectral Angle Mapper) method in order to facilitate analysis of the spectral characteristics of the studied area. Finally, for 13 samples, correlations among soil characteristics and spectral data from the HSS sensor, and spectral curves obtained in laboratory were carried out. Results indicated that: (a) the atmospheric correction accomplished with the FLAASH applicative was appropriate, despite difficulties for total removal of the water vapor feature at 0.94μm and at short-wave infrared band, near to 2.0μm. In general, a spectral coherence of the HSS sensor was confirmed with the information found in literature and the spectrum obtained in the laboratory; (b) a good capacity for spectral identification was observed with the SAM classifier as the results provided an appropriate soil preidentification, helping as well to define sites for field work; (c) the spectral curves representative of the soil classes are comparable both for laboratory and sensor data. Usually, correlations between both data acquisition environments (laboratory and HSS) are high. © 2012 Sociedade Brasileira de Geofísica.


e Silva L.F.R.,National Institute of Amazonian Research | e Silva L.F.R.,University of the State of Amazonas | e Silva L.F.R.,Centro Universitario do Norte | de Magalhaes P.M.,University of Campinas | And 6 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2012

Artemisinin is the active antimalarial compound obtained from the leaves of Artemisia annua L. Artemisinin, and its semi-synthetic derivatives, are the main drugs used to treat multi-drug-resistant Plasmodium falciparum (one of the human malaria parasite species). The in vitro susceptibility of P. falciparum K1 and 3d7 strains and field isolates from the state of Amazonas, Brazil, to A. annua infusions (5 g dry leaves in 1 L of boiling water) and the drug standards chloroquine, quinine and artemisinin were evaluated. The A. annua used was cultivated in three Amazon ecosystems (várzea, terra preta de índio and terra firme) and in the city of Paulínia, state of São Paulo, Brazil. Artemisinin levels in the A. annua leaves used were 0.90-1.13% (m/m). The concentration of artemisinin in the infusions was 40-46 mg/L. Field P. falciparum isolates were resistant to chloroquine and sensitive to quinine and artemisinin. The average 50% inhibition concentration values for A. annua infusions against field isolates were 0.11-0.14 μL/mL (these infusions exhibited artemisinin concentrations of 4.7-5.6 ng/mL) and were active in vitro against P. falciparum due to their artemisinin concentration. No synergistic effect was observed for artemisinin in the infusions.


Bini R.R.,University of Auckland | Bini R.R.,Federal University of Rio Grande do Sul | Rossato M.,Centro Universitario Do Norte | Diefenthaeler F.,Federal University of Rio Grande do Sul | And 3 more authors.
Isokinetics and Exercise Science | Year: 2010

The aim of the present study was to compare the effects of small changes in pedaling cadence (20% higher and lower than the freely chosen) on hip, knee, and ankle mechanical parameters. Right pedal forces and lower limb kinematics of cyclists were measured with workload at 80% of peak power output, for three pedaling cadences (freely chosen cadence - FCC; 20% below the FCC - FCC -20%; and 20% higher than the FCC - FCC +20%). Forces, kinematics and mechanical work were calculated for hip, knee and ankle joints. Knee joint mechanical work decreased at FCC +20% (55 ± 13 J, compared to FCC - 66 ± 11 J and to FCC -20% - 72 ± 7 J), while the contribution of each joint to the total mechanical work (TMW) was not affected by pedaling cadence. Joint forces were not influenced by pedaling cadence. Ankle joint angle increased (155 ± 3° compared to FCC - 152 ± 2° and to FCC -20%-149 ± 3°), while knee (59 ± 3° compared to FCC - 62 ± 2° and to FCC -20% - 64 ± 1°), and ankle (15 ± 4° compared to FCC - 18 ± 1° and to FCC -20% - 20 ± 2°) range of motion (ROM) decreased at FCC +20%. The effects of pedaling cadence on joint mechanical work and kinematics indicate that the FCC does not minimize joint mechanical work and force production for all lower limb joints. The knee joint tunes the power production by the mechanical work while the ankle function seems to be dependent on joint kinematics when pedaling cadence is increased. © 2010 IOS Press and the authors. All rights reserved.


Dairiki J.K.,Embrapa Amazonia Ocidental | Correa R.B.,Centro Universitario do Norte | Inoue L.A.K.A.,Embrapa Amazonia Ocidental | Morais I.D.S.D.,Embrapa Amazonia Ocidental
Pesquisa Agropecuaria Brasileira | Year: 2013

The objective of this work was to evaluate the effect of the inclusion of cowpea (Vigna unguiculata) in diets on the performance of juvenile tambaqui (Colossoma macropomum). The experiment was carried out in a completely randomized design with three replicates of 20 juvenile tambaqui (10 g), allocated in 310-L water tanks. The fish were fed for 60 days with isonitrogenous and isoenergetic diets, with six inclusion levels of cowpea: 0, 5, 10, 15, 20, and 25%. Body and productive performance relations were determined. There was no significant difference between treatments. Juvenile tambaqui can be fed with the inclusion of up to 25% cowpea in the diet.


Ribeiro A.S.,Centro Universitario Nilton Lins | Batista E.S.,Centro Universitario do Norte | Dairiki J.K.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Chaves F.C.M.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Inoue L.A.K.A.,Embrapa Agropecuaria Oeste
Acta Scientiarum - Animal Sciences | Year: 2016

The matrinxã fish is suitable for Amazonian aquaculture, exhibiting positive characteristics such as good growth and feed conversion ratio. However, it is a very active fish and must be anesthetized for handling. The present study evaluated the use of Ocimum gratissimum essential oil (EO) as anesthetic for juvenile matrinxãs. A first experiment assessed the induction time to anesthesia of 7 concentrations (20, 30, 40, 50, 60, 70 and 80 mg L-1 of O. gratissimum (EO). A second experiment investigated the physiological response to the anesthetic through analysis of tissue and blood parameters collected 0h (T0) and 24h after (T24) the experimental protocols that were applied to 4 groups: control, handling without O. gratissimum (EO) and handling with two EO levels. In the first experiment, fish were anesthetized within 10 min in the lowest EO concentration (20 mg L-1), and recovered within 2 min. As concentrations increased times to induction to anesthesia decreased from 10 min to 1 min (approximately). In the second experiment, plasma lactate, glucose and ammonia increased in the treatments involving handling and EO concentrations. After 24h, fish had recovered from the experimental procedures, and no mortality was observed in the next 30 days. Ocimum gratissimum was shown to be a suitable anesthetic for matrinxãs, and causes minimum stress to fish in the concentrations and exposure time applied. © 2016, Eduem - Editora da Universidade Estadual de Maringa. All rights reserved.

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