RESUMEN
Genotyping of Toxoplasma gondii in different regions of Brazil has shown high diversity and high frequency of virulent genotypes among Brazilian animals. The aim of the study was to characterize samples of T. gondii isolates obtained from naturally infected sheep, goats, pigs and free-range chickens slaughtered for human consumption in Rio Grande do Norte, Northeast Brazil. Nineteen T. gondii samples (isolated from 1 goat, 5 pigs and 13 free-range chickens) were genotyped. Six different genotypes were identified, including two novel genotypes. The archetype genotypes, i.e., types I, II and III, were not found. In mice, seventeen isolates (89.5%) were classified as virulent, and only two (10.5%) were classified as avirulent. This study displays the genotypic variability of the parasite in Northeast Brazil.
Asunto(s)
Toxoplasma/genética , Toxoplasmosis Animal/epidemiología , Animales , Brasil/epidemiología , Pollos/parasitología , Ensayo de Inmunoadsorción Enzimática/veterinaria , Genotipo , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/parasitología , Cabras/parasitología , Ratones/parasitología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/parasitología , Ovinos/parasitología , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/parasitología , Porcinos/parasitología , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/parasitología , Toxoplasmosis Animal/parasitologíaRESUMEN
Indole alkaloids ellipticine (1), cryptolepine triflate (2a), rationally designed 11-(4-piperidinamino)cryptolepine hydrogen dichloride (2b) and olivacine (3) (an isomer of 1) were evaluated in vitro against Plasmodium falciparum and in vivo in Plasmodium berghei-infected mice. 1-3 inhibited P. falciparum (IC50≤1.4 µM, order of activity: 2b>1>2a>3). In vitro toxicity to murine macrophages was evaluated and revealed selectivity indices (SI) of 10-12 for 2a and SI>2.8×10² for 1, 2b and 3. 1 administered orally at 50mg/kg/day was highly active against P. berghei (in vivo inhibition compared to untreated control (IVI)=100%, mean survival time (MST)>40 days, comparable activity to chloroquine control). 1 administered orally and subcutaneously was active at 10 mg/kg/day (IVI=70-77%; MST=27-29 days). 3 exhibited high oral activity at ≥50 mg/kg/day (IVI=90-97%, MST=23-27 days). Cryptolepine (2a) administered orally and subcutaneously exhibited moderate activity at 50mg/kg/day (IVI=43-63%, MST=24-25 days). At 50 mg/kg/day, 2b administered subcutaneously was lethal to infected mice (MST=3 days) and moderately active when administered orally (IVI=45-55%, MST=25 days). 1 and 3 are promising compounds for development of antimalarials.
Asunto(s)
Antimaláricos/uso terapéutico , Aspidosperma/química , Elipticinas/uso terapéutico , Alcaloides Indólicos/uso terapéutico , Malaria/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Quinolinas/uso terapéutico , Animales , Antimaláricos/farmacología , Elipticinas/aislamiento & purificación , Elipticinas/farmacología , Femenino , Alcaloides Indólicos/aislamiento & purificación , Alcaloides Indólicos/farmacología , Macrófagos/efectos de los fármacos , Malaria/parasitología , Ratones , Ratones Endogámicos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Plasmodium berghei/efectos de los fármacos , Plasmodium falciparum/efectos de los fármacos , Quinolinas/aislamiento & purificación , Quinolinas/farmacologíaRESUMEN
Micro and nanosystems-based products will be an important contributor to the industrial and economic future, as a key value adding element for many sectors. The adoption of micro and nano manufacturing technologies making use of a variety of materials, components and knowledge based technologies will most probably provide functionality and intelligence to highly miniaturised systems. Chemical Vapour Deposited (CVD) diamond is a hard material of high mechanical strength and thermal stability and therefore an ideal candidate for microelectromechanical devices. The latter, is already being used to manufacture sensors, resonators, actuators, biological devices or even plastic moulding impressions, by depositing the film on a structured substrate, by selective growth of diamond on Si using SiO2 masks, or by pattern etching on oxygen-containing plasma. The diamond shaping may also be performed by a fine tuning of the nucleation and growth process. In this paper, it is presented the results of diamond coated structures and an evaluation of its morphology variation with the substrate configuration. The grown films were characterized for quality, surface roughness and microstructure using scanning electron microscopy, Raman and X-ray diffraction spectroscopy and surface profilometry.
RESUMEN
For a number of biomedical applications, including the development of phantoms for quality control of radiotherapy treatments and dose determination, it is important to study the radiation response of the used materials, in order to distinguish the relevant dose distribution modifications from the artifacts caused by the phantom material when subjected to high dose irradiation. Beside the radiation response, those materials should have certain physical and chemical properties in order to be able to be used for the purposes described above, i.e., mechanical hardness and inelasticity, chemically stability and nonreactive, among others. In this work, a wide range of polymeric materials were irradiated under megavoltage radiation using a radiotherapy linear accelerator. The irradiated materials were imaged using transmission X-ray tomography to determine if some radiation induced electronic density change could result in altered Hounsfield units. Furthermore, Raman Spectroscopy and X-ray Diffraction (XRD) techniques were used before and after irradiation in order to study any structural modification induced by the radiation. In addition, a special phantom simulating a breast treatment with two tangential beams has been fabricated and tested.
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Equipos y Suministros , Polímeros , Radiación Ionizante , Tomografía por Rayos X , Difracción de Rayos XRESUMEN
Although large focus has been placed into the deposition of nanocrystalline and ultra-nanocrystalline diamond films, most of this research uses microwave plasma assisted CVD systems. However, the growth conditions used in microwave systems cannot be directly used in hot-filament CVD systems. This paper, aims to enlarge the knowledge of the diamond film depositing process. H2/CH4/Ar gas mixtures have been used to deposit micro, nano and ultra-nanocrystalline diamond films by hot-filament CVD systems. Additionally, the distance between the filaments array and the substrate was varied, in order to observe its effect and consequently the effect of a lower substrate temperature in the nucleation density and deposition. All the samples were characterized for microstructure and quality, using scanning electron microscopy and Raman spectroscopy.
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A mechanical seal is a type of seal used in rotating equipment, such as pumps and compressors. It consists of a mechanism that assists the connection of the rotating shaft to the housings of the equipments, preventing leakage or avoiding contamination. A common cause of failure of these devices is end face wear out, thus the use of a hard, smooth and wear resistant coating such as nanocrystalline diamond would be of great importance to improve their working performance and increase their lifetime. In this paper, different diamond coatings were deposited by the HFCVD process, using different deposition conditions. Additionally, the as-grown films were characterized for, quality, morphology and microstructure using scanning electron microscopy (SEM) and Raman spectroscopy. The topography and the roughness of the films were characterized by atomic force microscopy (AFM).
RESUMEN
Tungsten carbide alloys possess a large number of applications, due to its high hardness, high resistance to heat and to wear, which makes it ideal to be used in wear parts of machinery or on surfaces liable to corrosion, abrasion or high temperatures. For practical applications, it is alloyed with cobalt (Co) or nickel (Ni) in order to improve its properties. The increasing demand of broadening the operation limits of some components, impose the need to improve its life time. Coating these parts with hard and smooth diamond thin film may improve the wear performance and decrease their roughness and friction coefficient. In this work, a comparative study of nanodiamond films deposit onto WC-Co and WC-Ni, by means of a hot-filament Chemical Vapour Deposition (HFCVD) system, is presented. The study was accomplished by varying the CH4/H2/Ar gas ratio of the deposition process. The substrate temperature was kept low (< 700 degrees C) to minimize the thermal stress in the coating-substrate system. The microstructure of the deposited diamond film was characterized using Scanning Electron Microscopy (SEM), Raman spectroscopy and X-ray diffraction spectroscopy. Roughness of the working surfaces were also accessed prior and after the depositions.
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The inscription of a Fibre Bragg Grating (FBG) in optical fibres allows them to be used as sensors, being capable of decoding small variations of strain; temperature; pressure; loading; bending; or even refractive index, by means of a shift in the reflected wavelength. Nevertheless, broadening their sensitivity and operation range would be desirable. This may be achieved by appropriated fibre coating. Diamond possesses a set of extreme properties, such as high thermal conductivity, hardness and resistance to hazard environments. Furthermore, it is known for its excellent biocompatible response, so it may be suitable to be used as a coating material for biological sensors. In this paper, the results of the optimization process of diamond coatings on optical fibre sensors is presented, considering their potential use for practical biological purposes.
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Técnicas Biosensibles/instrumentación , Diamante/química , Fibras Ópticas , Microscopía Electrónica de Rastreo , Nanopartículas/química , Nanotecnología , Espectrometría RamanRESUMEN
Most medicinal plants used against malaria in endemic areas aim to treat the acute symptoms of the disease such as high temperature fevers with periodicity and chills. In some endemic areas of the Brazilian Amazon region one medicinal plant seems to be an exception: Ampelozyziphus amazonicus, locally named "Indian beer" or "Saracura-mira", used to prevent the disease when taken daily as a cold suspension of powdered dried roots. In previous work we found no activity of the plant extracts against malaria blood parasites in experimentally infected animals (mice and chickens) or in cultures of Plasmodium falciparum. However, in infections induced by sporozoites, chickens treated with plant extracts were partially protected against Plasmodium gallinaceum and showed reduced numbers of exoerythrocytic forms in the brain. We now present stronger evidence that the ethanolic extract of "Indian beer" roots hampers in vitro and in vivo development of Plasmodium berghei sporozoites, a rodent malaria parasite. Some mice treated with high doses of the plant extract did not become infected after sporozoite inoculation, whereas others had a delayed prepatent period and lower parasitemia. Our data validates the use of "Indian beer" as a remedy for malaria prophylaxis in the Amazon, where the plant exists and the disease represents an important problem which is difficult to control. Studies aiming to identify the active compounds responsible for the herein described causal prophylactic activity are needed and may lead to a new antimalarial prophylactic.
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Antimaláricos/uso terapéutico , Malaria/prevención & control , Extractos Vegetales/uso terapéutico , Plantas Medicinales/química , Plasmodium berghei/efectos de los fármacos , Plasmodium berghei/crecimiento & desarrollo , Rhamnaceae/química , Animales , Anopheles , Brasil , Femenino , Humanos , Malaria/tratamiento farmacológico , Malaria/parasitología , Masculino , Ratones , Esporozoítos/efectos de los fármacos , Esporozoítos/crecimiento & desarrolloRESUMEN
Sheep are important domestic animals in the Northeast region of Brazil due to their minimal rearing and maintenance costs, and to their production of both meat and milk. In animals, Toxoplasma gondii infection results in significant reproductive and economic losses. The epidemiology of toxoplasmosis in sheep in the Northeast of Brazil has been little studied; particularly in Rio Grande do Norte State. Sera from 102 sheep intended for consumption in Lajes were subjected to the Toxoplasma-ELISA test to detect anti-T. gondii specific IgG confirming a past infection. Of the total tested, 30 (29.41%) sera were positive for IgG with an increasing number of positive animals with advancing age. We used IgG avidity ELISA in 30 positive samples and observed that 6 (20%) had low avidity antibodies and 24 (80%) had high avidity antibodies. Epidemiological studies are required in order to identify sources of infection for these hosts as well as their impact on animal breeding in the region and risk of transmission to humans.
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Anticuerpos Antiprotozoarios/sangre , Inmunoglobulina G/sangre , Enfermedades de las Ovejas/epidemiología , Toxoplasma/inmunología , Toxoplasmosis Animal/epidemiología , Animales , Afinidad de Anticuerpos , Brasil/epidemiología , Estudios Seroepidemiológicos , Ovinos , Enfermedades de las Ovejas/parasitologíaRESUMEN
Five dogs from the municipalities of Santa Maria, Itaara and Júlio de Castilhos, in the centre of the Brazilian State of Rio Grande do Sul, were diagnosed as positive for visceral leishmaniasis. A survey was developed by indirect immunofluorescence in blood obtained in filter paper from 40 dogs from Santa Maria, 20 from Itaara and 11 from Júlio de Castilhos. Examined dogs were generally related to those reputedly positive. Besides the above dogs, blood from 44 stray dogs from Júlio de Castilhos, 68 from Cachoeira do Sul and 20 from Caçapava do Sul was also examined. Slightly positive sera ( 1:40) were examined with ELISA. PCR and histology was used to examine the liver, spleen, lungs and lymph nodes from a sixth dog considered at necropsy to be positive for visceral leishmaniasis. All results for the 204 dogs were negative. This indicates that visceral leishmaniasis, due to various factors discussed below, is extremely rare in this region. A more detailed exam of the material from the five dogs considered positive is necessary.
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Enfermedades de los Perros/parasitología , Leishmaniasis Visceral/veterinaria , Animales , Brasil/epidemiología , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/epidemiología , Perros , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/epidemiología , Estudios SeroepidemiológicosRESUMEN
For centuries, malaria was treated with the bark of Cinchona calisaya and Cinchona succirubra plants named "quinas" in Brazil, from which the quinine molecule was isolated. Other plant species known also as "quinas" are used to treat fever and malaria, like Deianira erubescens (roots and leaves), Strychnos pseudoquina (bark), and Remijia ferruginea (bark). Based on this popular knowledge, we evaluated the in vivo antimalarial activity of the ethanol crude extracts of these plant species in mice infected with Plasmodium berghei. Only Remijia ferruginea showed antimalarial activity, reducing parasitaemia and mortality at the highest dose tested. Its phytochemical analysis showed the presence of alkaloids but not quinine. The other two plant species were inactive.
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Antimaláricos/uso terapéutico , Cinchona/química , Fiebre/tratamiento farmacológico , Malaria/tratamiento farmacológico , Fitoterapia , Plasmodium berghei/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , Brasil , Etanol , Malaria/mortalidad , Malaria/parasitología , Ratones , Corteza de la Planta/química , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Hojas de la Planta/química , Raíces de Plantas/química , AguaRESUMEN
A partir de relato de diagnóstico de leishmaniose visceral em cinco cäes dos municípios de Santa Maria, Itaara e Júlio de Castilhos, no centro do Estado do Rio Grande do Sul, foi realizado levantamento sorológico através de teste de imunofluorescência indireta em sangue obtido em papel de filtro de 40 cäes de Santa Maria, 20 de Itaara e 11 de Júlio de Castilhos, em geral relacionados aos cinco cäes considerados como positivos. Além destes, foi também examinado o sangue de 44 cäes vadios de Júlio de Castilhos, 68 de Cachoeira do Sul e 20 de Caçapava do Sul. Soros fracamente reagentes com títulos < 1:40 foram avaliados em ensaios de Ensaio Imuno-enzimático. Amostras de fígado, baço, pulmäo e linfonodos de um sexto cäo de Santa Maria, considerado como positivo à necropsia, foram examinadas através de histopatologia e PCR. Todos os resultados dos 204 cäes foram negativos, indicando que, apesar de näo ser impossível a ocorrência de leishmaniose visceral na regiäo, por vários fatores aqui discutidos, ela deve ser pelo menos extremamente rara, sendo necessários estudos mais detalhados do material dos cinco cäes tidos como positivos
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Animales , Perros , Enfermedades de los Perros , Leishmaniasis Visceral , Brasil , Enfermedades de los Perros , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente Indirecta , Reacción en Cadena de la Polimerasa , VíscerasRESUMEN
The purpose of this clinic-based study was the assessment of symptoms of depression, anxiety, and non-specific psychiatric disorders amongst patients with migraine, compared with healthy subjects and with individuals with a non-neurological chronic disease. A cross-sectional study was carried out in which 178 individuals (migraine 51; psoriasis 35; healthy 92) were submitted to three scales: MADRS (depression), STAI-T (anxiety) and SRQ (screening for mental disorders). The subjects with migraine and psoriasis were from the Out-patient Clinics of Headache and of Dermatology, and the healthy volunteers were persons who were accompanying out-patients in the same hospital. Scores were analysed by manova and by association analysis and logistic regression. Scores of all instruments were higher in the migrainous group, but the univariate analysis of association (using cut-offs) showed significance only for suspicion of mental disorders (SRQ). By logistic regression, variables with strongest association to migraine were gender, education, and SRQ in decreasing order.
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Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología , Trastornos Migrañosos/diagnóstico , Trastornos Migrañosos/epidemiología , Medición de Riesgo/métodos , Adulto , Factores de Edad , Ansiedad/diagnóstico , Ansiedad/epidemiología , Ansiedad/psicología , Brasil/epidemiología , Estudios Transversales , Depresión/diagnóstico , Depresión/epidemiología , Depresión/psicología , Escolaridad , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Tamizaje Masivo , Trastornos Mentales/psicología , Trastornos Migrañosos/psicología , Psoriasis/diagnóstico , Psoriasis/epidemiología , Psoriasis/psicología , Factores de Riesgo , Autoevaluación (Psicología) , Factores SexualesRESUMEN
In this review we discuss the ongoing situation of human malaria in the Brazilian Amazon, where it is endemic causing over 610,000 new acute cases yearly, a number which is on the increase. This is partly a result of drug resistant parasites and new antimalarial drugs are urgently needed. The approaches we have used in the search of new drugs during decades are now reviewed and include ethnopharmocology, plants randomly selected, extracts or isolated substances from plants shown to be active against the blood stage parasites in our previous studies. Emphasis is given on the medicinal plant Bidens pilosa, proven to be active against the parasite blood stages in tests using freshly prepared plant extracts. The anti-sporozoite activity of one plant used in the Brazilian endemic area to prevent malaria is also described, the so called "Indian beer" (Ampelozizyphus amazonicus, Rhamnaceae). Freshly prepared extracts from the roots of this plant were totally inactive against blood stage parasites, but active against sporozoites of Plasmodium gallinaceum or the primary exoerythrocytic stages reducing tissue parasitism in inoculated chickens. This result will be of practical importance if confirmed in mammalian malaria. Problems and perspectives in the search for antimalarial drugs are discussed as well as the toxicological and clinical trials to validate some of the active plants for public health use in Brazil.